Chapter 3: Structure and Function of the Cell

Chapter 3: Structure and Function of the Cell Multiple Choice 1. The structural and functional unit of all living organisms is the A)ribosome. B)cell. C)organ. D)organelle. E)plasma membrane. Answer: b Level: 1 2. Which of the following could be used to study general features of cells? A)a magnifying glass B)scanning electron microscope C)transmission electron microscope D)binoculars E)light microscope Answer: e Level: 1 3. In order to study in detail, the anatomy of internal cell parts, it would be best to use A)x-rays. B)flashlights. C)a transmission electron microscope (TEM). D)tissue cultures. E)a scanning electron microscope (SEM).Answer: c Level: 1 4. The plasma membrane A)separates the nucleus from the rest of the cell. B)is a rigid protein membrane. C)is not permeable. D)has a single layer of phospholipids. E)regulates movement of materials into and out of the cell. Answer: e Level: 1 5. The environment outside the plasma membrane is most appropriately referred to as A)intrac ellular. B)extracellular. C)multicellular. D)centrocellular. E)none of the above. Answer: b Level: 1 6. The fluid-mosaic model of the plasma membrane suggests that A)cholesterol forms the outermost layer of the membrane. B)proteins form a â€Å"liquid† sea in the membrane.C)phospholipids form a single lipid layer in the center of the membrane. D)the membrane is neither rigid nor static in structure. E)proteins are not a part of the membrane. Answer: d Level: 1 7. According to the most current model of the plasma membrane A)cholesterol forms the innermost layer of the membrane B)proteins are free to move about with a double layer of phospholipids C)phospholipids and cholesterol form a single lipid bilayer D)the membrane is a rigid unchanging structure E)the membrane is impermeable to all other molecules. Answer: b Level: 1 8. Which of the following activities is a function of the plasma membrane?A)digestion of unneeded cell organelles B)recognition of bacterial cells by the im mune system C)transport of products from the nucleus to the endoplasmic reticulum D)cell metabolism E)detoxification Answer: b Level: 2 9. Plasma membrane phospholipids A)have polar (charged) tails. B)are arranged in a single layer. C)have tails that face the exterior of the membrane. D)are 95% cholesterol. E)have a hydrophilic head and hydrophobic tails. Answer: e Level: 1 10. Which of the following is correctly matched with its function? A)channel proteins – are part of an intercellular communication system B)marker molecules – are primarily steroidsC)receptor molecules – attach to ligand molecules. D)peripheral proteins – penetrate the lipid bilayer from one surface to the other. E)nongated ion channels – are always closed. Answer: c Level: 1 11. In general, water-soluble molecules diffuse through the ______ ______; and lipid-soluble molecules diffuse through the ______ ______. A)protein channels; protein channels B)protein channels; bilipid lay er C)bilipid layer; protein channels D)bilipid layer; bilipid layer E)none of the above Answer: b Level: 2 12. Cell membrane phospholipids A)have nonpolar fatty acid tails. B)form a bilayer. C)have polar phosphate heads.D)create a selectively permeable barrier. E)all of the above Answer: e Level: 1 13. When a sperm cell comes into contact with an egg cell, there is a change in the electrical charge across the plasma membrane and various channel proteins close. These channels would be called A)open-gated channels. B)voltage-gated channels. C)chemical-gated channels. D)ligand-gated channels. E)nongated ion channels. Answer: b Level: 2 14. Communication between cells occurs when chemical messengers from one cell bind to _____ on another cell. A)channel proteins B)receptor molecules C)marker molecules D)second messengersE)integrins. Answer: b Level: 1 15. Channel proteins A)are binding sites for other molecules. B)utilize the G protein complex to function. C)are found only on endoplasmi c reticulum. D)allow cells to recognize one another. E)provide a â€Å"door† through which extracellular molecules can enter the cell Answer: e Level: 1 16. Molecules that serve as chemical signals in cell to cell communication are called A)isotopes. B)ligands. C)responders. D)communicators. E)membrane potentials. Answer: b Level: 1 17. Cells that respond to ligands A)possess receptor sites for specific ligands. B)generally produce the ligands.C)have lysosomes that destroy the ligands. D)are using electrical signals in cellualar communication. E)are not functional. Answer: a Level: 1 18. Membrane-bound receptors A)are small, lipid soluble molecules. B)have their receptor sites on the outer surface of the plasma membrane. C)can interact with DNA in the nucleus. D)do not exhibit specificity. E)have no effect on the cell. Answer: b Level: 1 19. Consider the following events and choose the one that occurs last. A)Acetylcholine is released from neurons. B)Acetylcholine diffuses ac ross the synapse to the receptor. C)Na+ ion channels in the plasma membrane are opened.D)Acetylcholine binds to membrane-bound receptors on skeletal muscle cells E)Na+ ions diffuse into skeletal muscle cells. Answer: e Level: 2 20. G proteins are found associated with the A)nucleus. B)cytoplasm. C)Golgi body. D)plasma membrane. E)ribosome. Answer: d Level: 1 21. Communication between cells is essential to coordinate the activity of the trillions of cell that make up the human body. Which of the following is (are) directly involved in carrying out communication between cells? A)lipid bilayer of the plasma membrane B)receptor molecules of plasma membrane C)chemical signal molecules released by cells D)mitochondriaE)b and c Answer: e Level: 1 22. The plasma membrane is selectively permeable. This means A)only gases and water can pass through it. B)substances need permission to pass through it. C)only certain substances can pass through it. D)substances need carrier molecules to pass th rough it. E)ATP is always needed to move molecules across the plasma membrane. Answer: c Level: 1 23. Vitamin A, a fat-soluble vitamin, would move across the plasma membrane into the cell A)in vesicles. B)through vitamin membrane channels. C)by dissolving in the lipid bilayer. D)by transport with carrier molecules. E)by active transport. Answer: c Level: 2 24.Which of the following statements concerning membrane transport across the plasma membrane is true? A)Polar molecules are transported more easily than nonpolar molecules. B)Lipid-soluble substances pass through the membrane by dissolving in the lipid bilayer. C)Water cannot move through the membrane. D)Generally, cations pass through the membrane more easily than anions. E)All molecules are moved across by active transport. Answer: b Level: 1 25. The aroma of cookies baking in the kitchen reaches you in the living room. The distribution of this odor throughout the house is an example of A)active transport. B)dialysis. C)osmosis . D)filtration.E)simple diffusion. Answer: e Level: 2 26. In the process of diffusion, net movement of substances is always from a region A)outside the cell to a region inside the cell. B)inside the cell to a region outside the cell. C)of lower concentration to a region of higher concentration. D)of higher concentration to a region of lower concentration. E)none of the above Answer: d Level: 1 27. Which of the following will increase the rate of diffusion? A)an increase in the viscosity of the solvent B)an increase in the temperature C)an increase in the molecular weight of the diffusing particles D)an increase in the distance the molecules have to travelE)all of the above Answer: b Level: 1 28. Salt was added to a beaker of distilled water (the water was not stirred). A sample taken from the bottom of the beaker was found to be 20% salt. At the same time, a sample taken from the top of the beaker was found to be 2% salt. After 24 hours A)the difference in the percentage of salt bet ween the top and bottom samples would increase. B)the percentage of salt in top and bottom samples would be approximately equal. C)the samples would still be 2% and 20% respectively. D)the salt would float to the top. E)none of the above Answer: b Level: 2 29.The movement of oxygen from the alveoli of the lungs into the bloodstream is an example of A)diffusion. B)osmosis. C)active transport. D)bulk transport. E)facilitated diffusion. Answer: a Level: 2 30. Osmosis is the diffusion of _____ across a selectively permeable membrane. A)urea B)oxygen C)water D)sodium E)sugar Answer: c Level: 1 31. Solution A contains 5 grams of sugar per liter while solution B contains 2 grams of sugar per liter. The solutions are separated by a selectively permeable membrane. If the solvent in both solutions is water, predict in which direction most of the water molecules will move.A)move by simple diffusion from solution A to solution B B)move by osmosis from solution B to solution A C)move by active t ransport from solution B to solution A D)move by filtration from solution A to solution B E)there will be no movement of water Answer: b Level: 3 32. The greater the concentration of a solution, the greater A)the tendency for water to diffuse from the solution. B)the osmotic pressure of the solution. C)the number of carrier molecules present. D)the amount of solvent. E)the rate of facilitated diffusion. Answer: b Level: 1 33. A red blood cell that is placed in a hypertonic solution, A)gains water.B)loses water. C)floats. D)ruptures. E)neither gains nor loses water. Answer: b Level: 2 34. If 0. 9% saline solution is isotonic to a cell, then a 0. 5% saline solution A)is hypertonic to the cell. B)will cause crenation of the cell. C)is hypotonic to the cell. D)will shrink the cell. E)will not affect the cell. Answer: c Level: 2 35. A person suffered from burns over a large part of his body. Evaporation of fluid from the surface of burned areas occurs. As a result of the evaporation proc ess, cells will tend to A)shrink. B)swell. C)rupture. D)first swell and then resume their original shape. E)remain unchanged. Answer: aLevel: 2 36. Plasma has an osmolality of 300 mOsm. A solution isosmotic with plasma has an osmolality of A)150 mOsm. B)300 mOsm. C)450 mOsm. D)600 mOsm. E)900 mOsm. Answer: b Level: 2 37. A runner produced hypotonic sweat while running a marathon in hot weather. After the race he drank large volumes of water, as a result of the water intake his body cells will A)shrink. B)swell. C)crenate. D)shrivel. E)not change. Answer: b Level: 2 38. The movement of a solution across a plasma membrane because of a pressure gradient is called A)diffusion. B)osmosis. C)facilitated diffusion. D)active transport. E)filtration. Answer: eLevel: 1 39. Which of the following would increase the rate of mediated transport? A)increase the number of available carrier molecules B)change the shape of the binding site on the carrier molecule C)increase the number of competitive molecules D)fill all binding sites on carrier molecules E)remove the binding site on the carrier molecule Answer: a Level: 2 40. A particular membrane transport process exhibits saturation, uses carrier molecules, but does not require ATP. The process is probably A)active transport. B)facilitated diffusion. C)osmosis. D)pinocytosis. E)phagocytosis. Answer: b Level: 2 41. Active transportA)follows osmotic pressure gradients. B)can move substances along their concentration gradient. C)does not requires metabolic energy (ATP). D)involves vesicle formation. E)requires ATP. Answer: e Level: 1 42. Which of the following are consistent with active transport? 1. movement is against a concentration gradient 2. movement is with a concentration gradient 3. involves a carrier molecule 4. can involve cotransport 5. can involve counter transport 6. exhibits competition and saturation A)1, 3, 4, 5, 6 B)2, 3, 4, 5 C)2, 3, 4, 5, 6 D)1, 3, 4, 6 E)1, 3, 5, 6 Answer: a Level: 2 43. Cyanide stops the pr oduction of ATP.Which of the following processes would be affected? A)simple diffusion B)osmosis C)active transport D)facilitated diffusion E)filtration Answer: c Level: 2 44. The sodium-potassium exchange pump located in the plasma membrane A)actively transports potassium into cells. B)osmotically moves sodium into cells. C)actively transports water out of cells. D)moves chlorine out of cells. E)actively transports sodium into cells. Answer: a Level: 1 45. When ions or molecules involved in secondary active transport move in the same direction, the process is called A)facilitated diffusion. B)counter-transport. C)exocytosis. D)cotransport. E)endocytosis.Answer: d Level: 1 46. Which of the following events occurs in the secondary active transport of glucose? A)Na+ ions and glucose are cotransported by the same carrier molecule. B)The Na+-K+ pump maintains a Na+ concentration gradient inside the cell. C)Energy comes from diffusion of Na+ down their concentration gradient. D)Glucose i s moved against its concentration gradient into the cell. E)all of the above Answer: e Level: 2 47. A group of cells was treated with a proteolytic (protein-digesting) enzyme. Which of the following processes would be least affected by this treatment? A)diffusion of sodium through sodium membrane channelsB)diffusion of lipid-soluble molecules through the plasma membrane C)use of carrier molecules in facilitated diffusion D)sodium-potassium exchange pump E)secondary active transport Answer: b Level: 2 48. Certain cells in the liver ingest bacteria and debris from damaged cells by a process called A)pinocytosis. B)phagocytosis. C)biocytosis. D)calmly regulated diffusion. E)exocytosis. Answer: b Level: 2 49. Pinocytosis A)is a form of exocytosis. B)involves ingestion of liquids rather than particles. C)does not require ATP. D)forms vesicles only when large amounts of material are being transported. E)does not require the formation of vesicles.Answer: b Level: 1 50. Endocytosis A)is mov ement of water through a selectively permeable membrane. B)is a process that requires a carrier molecule but does not use cellular energy. C)is the bulk uptake of material through the plasma membrane by vesicle formation. D)moves material out of the cell. E)ends cell functions. Answer: c Level: 1 51. Arrange the following events of exocytosis in the correct sequence: 1. vesicle membrane fuses with plasma membrane 2. secretory vesicles migrate to plasma membrane 3. vesicle contents are expelled from cell 4. secretions accumulate within secretory vesicles A)2, 1, 4, 3B)1, 4, 2, 3 C)3, 1, 4, 2 D)4, 2, 1, 3 E)1, 2, 3, 4 Answer: d Level: 3 52. Receptor-mediated endocytosis A)does not need ATP; the receptors supply the energy. B)exhibits specificity. C)occurs if oxygen is available. D)is a type of passive transport. E)moves materials out of the cell. Answer: b Level: 1 53. Which of the following are consistent with facilitated diffusion? 1. movement is against a concentration gradient 2. movement is with a concentration gradient 3. involves a carrier molecule 4. involves cotransport 5. involves counter transport 6. exhibits competition and saturation A)1, 2, 4, 5, 6 B)2, 3, 6C)2, 3, 5, 6 D)1, 3, 4, 5, 6 E)2, 3, 4, 6 Answer: b Level: 2 54. Which of the following would increase the maximum rate of facilitated diffusion? A)increase the concentration gradient of the transported molecule B)decrease the concentration gradient of the transported molecule C)increase the concentration of the competitive molecules D)increased ATP synthesis E)none of the above Answer: e Level: 3 55. If a toxic drug inhibited mRNA synthesis, which of the following would be most directly affected? A)protein synthesis B)intracellular digestion C)microtubule production D)secretion of glycoproteins and lipoproteinsE)active transport Answer: a Level: 2 56. Cytoplasm is found A)in the nucleus. B)outside the nucleus but inside the plasma membrane. C)in the cisternae of the endoplasmic reticulum. D)on the cristae of the mitochondria. E)between the phospholipids in the plasma membrane. Answer: b Level: 1 57. The cytoskeleton consists of A)lipochromes, microfilaments, and microtubules. B)actin filaments, mitochondria, and intermediate filaments. C)microfilaments, mitochondria, and lipochromes. D)microtubules, actin filaments, and intermediate filaments. E)ribosomes, the nucleus, and the Golgi apparatus. Answer: d Level: 1 58.Absence of a cytoskeleton might affect A)cell shape. B)the number of channel proteins in the cell membrane. C)the ability of the cell to generate energy. D)vesicle formation. E)membrane transport. Answer: a Level: 1 59. Microtubules A)are the smallest components of the cytoskeleton. B)contains the protein myosin. C)provide structure and support to the cytoplasm. D)are solid, supporting rods of protein. E)are a component of mitochondria. Answer: c Level: 1 60. Of the organelles listed, which one does not contain microtubules? A)cilia B)flagella C)centrioles D)mi crovilli E)basal bodies Answer: d Level: 1 61.Organelles A)are extracellular structures. B)are unspecialized portions of a cell. C)generally lack membranes. D)vary in number and type depending on cell function. E)are structural, but not functional parts of the cell. Answer: d Level: 2 62. Which of the following organelles function in the destruction of nonfunctional organelles? A)endoplasmic reticulum B)centrioles C)basal bodies D)lysosomes E)mitochondria Answer: d Level: 1 63. Ribosomes are organelles responsible for A)protein synthesis. B)manufacturing lipids. C)cell movement and cell shape. D)packaging â€Å"cell products† for export. E)energy production.Answer: a Level: 1 64. Cells that lack ribosomes cannot A)produce energy. B)eliminate wastes. C)engage in protein synthesis. D)package cellular products. E)ingest and phagocytize bacteria. Answer: c Level: 1 65. Skeletal muscle cells need large numbers of _______ to make the many proteins they contain. A)centrosomes B)pero xisomes C)liposomes D)ribosomes E)lysosomes Answer: d Level: 2 66. If you compare a cell with a manufacturing plant that exports goods, the cell's _____ could be compared to the manufacturing plant's shipping department. A)nucleus B)lysosome C)Golgi apparatus D)endoplasmic reticulumE)ribosome Answer: c Level: 2 67. The organelle that protects cells from the damaging effects of medications and toxins is the A)ribosome. B)microtubule. C)secretory vesicle. D)smooth endoplasmic reticulum. E)mitochondria. Answer: d Level: 1 68. The function of the Golgi apparatus is A)packaging and distribution of proteins and lipids. B)production of microtubules. C)excretion of excess salt. D)DNA replication. E)energy production. Answer: a Level: 1 69. Endoplasmic reticulum with ribosomes attached to it is called A)smooth ER. B)dendritic ER. C)nodular ER. D)bumpy ER. E)rough ER. Answer: e Level: 1 70.A cell that produces many proteins for secretion from the cell would have large numbers of A)rough ER an d Golgi. B)lysosomes and Golgi. C)Golgi and microvilli. D)ribosomes and centrioles. E)mitochondria and cilia. Answer: a Level: 2 71. Arrange the following in correct sequence: 1. Protein moves through ER and then carried in vesicles to Golgi. 2. Vesicle pinches off from Golgi and carries product to plasma membrane. 3. Golgi modifies protein and then packages them into vesicles. 4. Protein made by ribosomes on rough ER. A)1, 2, 3, 4 B)4, 1, 3, 2 C)2, 3, 1, 4 D)3, 2, 4, 1 E)4, 3, 2, 1 Answer: b Level: 2 72.A toxic drug destroyed the Golgi apparatus. This would affect A)ribosomal RNA synthesis. B)intracellular digestion. C)energy production. D)microtubule production. E)packaging of glycoproteins and lipoproteins. Answer: e Level: 2 73. The intracellular digestive system of a cell is the A)lysosome. B)microtubule. C)lipochrome. D)rough endoplasmic reticulum. E)smooth endoplasmic reticulum. Answer: a Level: 1 74. White blood cells eat other cells and would be expected to A)have large num bers of lysosomes. B)possess cilia on their surfaces so they can move quickly. C)excrete excess salt as a result of all this eating.D)expel their nuclei to make room for all of the cells they eat. E)have mitochondria to energize them. Answer: a Level: 2 75. Which of the following activities is associated with lysosomes? A)exocytosis B)intracellular support C)destruction of nonfunctional organelles D)energy production E)endocytosis Answer: c Level: 1 76. A cell with abundant peroxisomes would most likely be involved in A)secretion. B)storage of glycogen. C)detoxification activities. D)cellular communication. E)protein synthesis. Answer: c Level: 1 77. Damaged cells can destroy nearby healthy cells when they release ________ enzymes. A)mitochondrialB)nuclear C)microtubular D)lysosomal E)cytoplasmic Answer: d Level: 1 78. A cell's ability to replenish ATP is reduced by a metabolic poison. Which organelle is being affected? A)nucleus B)centriole C)microtubule D)mitochondrion E)ribosomes Answer: d Level: 2 79. Experimental manipulation to increase the energy output of the cell might include A)rupturing the lysosomes in the cell. B)increasing the number of mitochondria. C)decreasing nuclear size. D)removing some of the ribosomes. E)increasing protein synthesis. Answer: b Level: 1 80. Which of the following terms does not relate to the mitochondria? A)cristaeB)self-replicating C)outer and inner membranes D)ATP E)vitamin A storage Answer: e Level: 1 81. When a person trains for running long distances, which of the following organelles increase in his/her muscles? A)rough endoplasmic reticulum B)enzymes for glycolysis C)basal bodies D)lysosomes E)mitochondria Answer: e Level: 2 82. You are looking at a cell with the electron microscope and you notice the following characteristics: presence of many mitochondria and lysosomes; few, if any, Golgi; and many ribosomes. Which of the following is the most likely function of that cell? A)secretion of lipids B)intracellular dig estionC)DNA replication D)modification of protein E)absorption of nutrients Answer: b Level: 2 83. Which of the following pairs of terms is mismatched? A)mitochondria – cristae B)Golgi apparatus – cisternae C)lysosomes – hydrolytic enzymes D)smooth endoplasmic reticulum — chromatin E)cilia – basal bodies Answer: d Level: 1 84. Mitochondria A)contains DNA. B)have inner and outer membranes. C)have inner folds called cristae. D)are the cell’s power plants. E)all of the above Answer: e Level: 1 85. Which of the following cell organelles is correctly matched with its function? A)nucleolus – contains the genetic material of the cellB)microtubules – cell support C)mitochondria – protein synthesis D)smooth ER – ATP production E)ribosome – energy production Answer: b Level: 1 86. A cell can meet increased energy demands by an A)increase in its overall size so it has more room to generate energy. B)increase in the nu mber of mitochondria. C)increase in lysosomal enzyme and ribosome activity within the cell. D)increase in nuclear DNA activity. E)increase in ribosomal subunits. Answer: b Level: 1 87. A cell uses centrioles in the process of A)cell division. B)energy generation. C)protein synthesis. D)RNA replication. E)nuclear centering.Answer: a Level: 1 88. Cilia and flagella are distinguished from each other on the basis of A)width and numbers. B)length and numbers. C)depth and numbers. D)length and width. E)none of the above Answer: b Level: 1 89. Microvilli A)are extensions of the lysosomal membrane. B)function to make the cell mobile. C)are supported by microtubules. D)move the cell. E)increase the surface area of the cell. Answer: e Level: 1 90. Which of the following cell organelles does not contain microtubules? A)cilia B)flagella C)spindle fibers D)centrioles E)All of the above contain microtubules. Answer: e Level: 1 91.The â€Å"control center† of the cell is the A)nucleus. B)ri bosome. C)mitochondrion. D)plasma membrane. E)endoplasmic reticulum. Answer: a Level: 1 92. Which of the following events occurs in the nucleus? A)large and small ribosomal subunits combine B)ribosomal proteins formed C)large and small ribosomal subunits form D)formation of free ribosomes E)None of the above occur in the nucleus. Answer: c Level: 1 93. Which of the following structures is found in the nucleus? A)cristae B)cytosol C)cisternae D)chromosome E)flattened membrane sacs Answer: d Level: 1 94. The nucleus of a cell functions to A)digest lipids.B)produce ATP. C)produce secretory vesicles. D)control and coordinate cellular activities. E)synthesize proteins. Answer: d Level: 1 95. Nucleoli A)are located in the cytoplasm. B)produce ribosomal subunits. C)have a distinct membrane. D)are important for the formation of the Golgi apparatus. E)regulates movement of materials into the nucleus. Answer: b Level: 1 96. Which of the following correctly matches a nuclear structure with its function? A)chromosomes – contains RNA and histones B)nuclear envelope – contains the nucleolar organizer C)nuclear pores – allow molecules to move between the nucleus and cytoplasm.D)chromatin – fluid portion of the nucleus E)nucleolus – DNA synthesis Answer: c Level: 1 97. Glycolysis A)converts glycogen to glucose. B)reduces pyruvic acid to carbon dioxide and water. C)converts glucose to pyruvic acid. D)is oxygen dependent. E)does not occur in the cell. Answer: c Level: 1 98. Aerobic respiration occurs when _______ is available. A)carbon dioxide B)oxygen C)lactic acid D)light E)nitrogen Answer: b Level: 1 99. Anaerobic respiration A)occurs in cells when oxygen supplies do not meet cell demands. B)produces 38 ATP molecules per glucose molecule. C)occurs in the mitochondria.D)frequently involves the electron transport system. E)is referred to as the â€Å"citric acid cycle. † Answer: a Level: 1 100. Messenger RNA A)is synthesized when a por tion of a DNA molecule is transcribed. B)directs the synthesis of DNA. C)determines the sequence of nucleotides in the anticodons of tRNA. D)directs the synthesis of centrioles in the cytoplasm. E)is not involved in the synthesis of proteins. Answer: a Level: 1 101. The transfer of information from DNA to messenger RNA (mRNA) is known as A)transduction. B)translocation. C)translation. D)transcription. E)transmutation. Answer: d Level: 1 102.Which of the following sequences is correct? A)translation ( protein synthesis ( transcription B)transcription ( translation ( protein synthesis C)transcription ( protein synthesis ( translation D)translation ( transcription ( protein synthesis E)protein synthesis ( translation (transcription Answer: b Level: 1 103. Translation A)requires three types of DNA. B)requires the pairing of codons on mRNA with anticodons on tRNA. C)involves synthesis of RNA from DNA molecules. D)takes place in the nucleus. E)requires replication of DNA. Answer: b Level: 1 104. Which of the following molecules contains the anticodon?A)mRNA B)rRNA C)tRNA D)DNA E)none of the above Answer: c Level: 1 105. If a mRNA molecule is 1800 nucleotides (bases) in length, this molecule will contain _____ codons. A)400 B)600 C)800 D)900 E)1200 Answer: b Level: 2 106. The sequence of nucleotides in a messenger RNA molecule is needed to determine the A)sequence of nucleotides in a gene. B)sequence of amino acids in a protein. C)sequence of nucleotides in the anticodons of tRNA. D)sequence of codons in DNA. E)sequence of amino acids in DNA. Answer: b Level: 1 107. Transcription A)requires three types of RNA. B)synthesizes RNA from DNA.C)occurs at the ribosomes. D)copies information from mRNA to tRNA. E)synthesizes DNA from RNA. Answer: b Level: 1 108. A DNA base sequence is A T G C C G. The sequence of bases in a strand of mRNA transcribed from this sequence of bases in DNA would be A)T A C G G C. B)U T C G G U. C)U A C G G C. D)A U G C C G. E)T A G G G G Answer: c Level: 2 109. The anticodon sequence GUA pairs with which of the following codons? A)CAT B)GUA C)CTU D)CAU E)CTT Answer: d Level: 2 110. Posttranscriptional processing is the modification of A)proteins to form pro-proteins. B)mRNA to form tRNA. C)pre-mRNA to form functional mRNA.D)exons to form introns. E)DNA. Answer: c Level: 1 111. Determine the sequence of the following events in a cell after exposure of the cell to a chemical signal. 1. increased synthesis of a protein 2. the chemical signal combined with a cytoplasmic receptor 3. an increase in the nuclear concentration of the chemical 4. an increase in mRNA synthesis 5. genes are activated A)2, 1, 3, 5, 4 B)2, 4, 5, 3, 2 C)2, 3, 5, 4, 1 D)2, 3, 4, 5, 1 E)1, 2, 3, 4, 5 Answer: c Level: 3 112. DNA replication results in two new DNA molecules. Each of these new molecules A)has two newly synthesized strands of nucleotides.B)has one strand of nucleotides from the parent DNA and one newly synthesized strand of nucleotides. C)has tw o strands of nucleotides from the parent. D)has a single strand of nucleotides. E)are incomplete copies of the original. Answer: b Level: 1 113. In DNA replication, A)the leading strand is formed as a continuous strand. B)new nucleotides are added at the 5†² end of the growing DNA strand. C)DNA polymerase splices the short segments of the lagging strand together. D)only introns are replicated. E)the two existing strands are not used as templates. Answer: a Level: 1 114. MitosisA)forms two daughter cells with half the DNA of the mother cell. B)forms two daughter cells with the same amount of DNA as the mother cell. C)forms daughter cells called gametes. D)forms two daughter cells with twice the amount of DNA as the mother cell. E)forms one daughter cell and another incomplete cell. Answer: b Level: 1 115. Human somatic cells contain _____ chromosomes, human gametes contain _____ chromosomes. A)23; 46 B)23; 23 C)46; 46 D)46; 23 E)92; 46 Answer: d Level: 1 116. DNA synthesis occur s during A)the G1 phase of interphase. B)telophase. C)the S phase of interphase. D)anaphase. E)metaphase. Answer: cLevel: 1 117. In prophase A)the chromosomes condense, shorten, and thicken. B)the spindle fibers disappear. C)the chromosomes replicate. D)cytokinesis occurs. E)DNA is synthesized. Answer: a Level: 1 118. Which of the following events occurs during anaphase? A)Chromatin strands condense to form chromosomes. B)Chromosomes migrate to opposite poles of the cell. C)Spindle fibers are formed. D)The nuclear envelope degenerates. E)Cytokinesis Answer: b Level: 1 119. Meiosis is the process of cell division that results in the formation of A)skin cells. B)gametes (egg and sperm). C)diploid cells. D)malignant cells. E)somatic cells.Answer: b Level: 1 120. Arrange the following events of meiosis in correct sequence. 1. pairs of homologous chromosomes separate 2. tetrad formation occurs 3. second meiotic division 4. tetrads align at the equatorial plate 5. interkinesis A)1, 3, 5, 2, 4 B)2, 4, 1, 5, 3 C)3, 1, 4, 5, 2 D)4, 1, 2, 5, 3 E)2, 4, 1, 3, 5 Answer: b Level: 2 121. Each of the cells that result from meiosis A)has the same number of chromosomes as the original cell. B)has half the number of chromosomes as the original cell. C)has one-fourth the number of chromosomes as the original cell. D)has twice the number of chromosomes as the original cell.E)has no chromosomes Answer: b Level: 1 122. Crossing over A)occurs during mitosis. B)increases the amount of genetic diversity. C)results in the formation of chromatids with the same DNA sequences. D)form tetrads. E)decreases the amount of genetic diversity. Answer: b Level: 1 Refer to the following diagram for questions 123-127. [pic] 123. What structure does â€Å"A† represent on the diagram of the plasma membrane? A)membrane channel protein B)phospholipid bilayer C)internal membrane surface D)peripheral protein E)receptor protein Answer: b Level: 1 124. What structure does â€Å"B† represent on the diagram of the plasma membrane?A)membrane channel protein B)phospholipid bilayer C)internal membrane surface D)peripheral protein E)receptor protein Answer: a Level: 1 125. What structure does â€Å"C† represent on the diagram of the plasma membrane? A)membrane channel protein B)phospholipid bilayer C)internal membrane surface D)peripheral protein E)receptor protein Answer: e Level: 1 126. What structure does â€Å"D† represent on the diagram of the plasma membrane? A)membrane channel protein B)phospholipid bilayer C)internal membrane surface D)peripheral protein E)receptor protein Answer: d Level: 1 127. What structure does â€Å"E† represent on the diagram of the plasma membrane?A)membrane channel protein B)phospholipid bilayer C)internal membrane surface D)peripheral protein E)receptor protein Answer: c Level: 1 Refer to the following diagram for questions 128-132. [pic] 128. Red blood cells (RBCs) have been placed in three different solutions: hypotonic , hypertonic, isotonic. What is solution â€Å"A† relative to the RBC? A)hypotonic solution B)hypertonic solution C)isotonic solution D)hemolyzed E)crenated Answer: c Level: 3 129. Red blood cells (RBCs) have been placed in three different solutions: hypotonic, hypertonic, isotonic. What is solution â€Å"B† relative to the RBC? A)hypotonic solutionB)hypertonic solution C)isotonic solution D)hemolyzed E)crenated Answer: b Level: 3 130. Red blood cells (RBCs) have been placed in three different solutions: hypotonic, hypertonic, isotonic. What is solution â€Å"C† relative to the RBC? A)hypotonic solution B)hypertonic solution C)isotonic solution D)hemolyzed E)crenated Answer: a Level: 3 131. Red blood cells (RBCs) have been placed in three different solutions: hypotonic, hypertonic, isotonic. What is the condition of the RBC in solution â€Å"C†? A)hypotonic solution B)hypertonic solution C)isotonic solution D)hemolyzed E)crenated Answer: d Level: 3 132.Re d blood cells (RBCs) have been placed in three different solutions: hypotonic, hypertonic, isotonic. What is the condition of the RBC in solution â€Å"B†? A)hypotonic solution B)hypertonic solution C)isotonic solution D)hemolyzed E)crenated Answer: e Level: 3 Refer to the following diagram for questions 133-137. [pic] 133. The diagram is an overview of cell metabolism. What does â€Å"A† represent? A)Glucose B)2 lactic acid + 2 ATP C)O2 D)6 CO2 + 6 H2O + 38 ATP E)Pyruvic acid Answer: e Level: 1 134. The diagram is an overview of cell metabolism. What does â€Å"B† represent? A)Glucose B)2 lactic acid + 2 ATP C)O2 D)6 CO2 + 6 H2O + 38 ATP E)Pyruvic acidAnswer: c Level: 1 135. The diagram is an overview of cell metabolism. What does â€Å"C† represent? A)Glucose B)2 lactic acid + 2 ATP C)O2 D)6 CO2 + 6 H2O + 38 ATP E)Pyruvic acid Answer: b Level: 1 136. The diagram is an overview of cell metabolism. What does â€Å"D† represent? A)Glucose B)2 lactic acid + 2 ATP C)O2 D)6 CO2 + 6 H2O + 38 ATP E)Pyruvic acid Answer: a Level: 1 137. The diagram is an overview of cell metabolism. What does â€Å"E† represent? A)Glucose B)2 lactic acid + 2 ATP C)O2 D)6 CO2 + 6 H2O + 38 ATP E)Pyruvic acid Answer: d Level: 1 For questions 138 to 142 match the following processes with the appropriate definition or description.A)requires a carrier molecule but does not use cellular energy B)bulk uptake of material by the formation of a vesicle C)movement of substances from areas of high concentration to areas of less concentration D)movement of water through a selectively permeable membrane E)movement of molecules against their concentration gradient 138. active transport Answer: e Level: 1 139. diffusion Answer: c Level: 1 140. endocytosis Answer: b Level: 1 141. facilitated diffusion Answer: a Level: 1 142. osmosis Answer: d Level: 1 For questions 143 to 147 match the following types of membrane proteins to its function.A)have exposed site on outer cell surface that can attach to ligand B)integral proteins that move ions or molecules across plasma membrane C)form a passageway through the plasma membrane D)allow cells to identify one another E)proteins that can catalyze chemical reactions on inner or outer surface of plasma membrane 143. Marker molecules Answer: d Level: 1 144. Channel protein Answer: c Level: 1 145. Receptor molecules Answer: a Level: 1 146. Enzymes Answer: e Level: 1 147. Carrier proteins Answer: b Level: 1 For questions 148 to 152 match the following cell organelles with the appropriate definition or description.A)source of the spindle fibers B)organelles that produce most of the cell’s energy C)sacs containing hydrolytic enzymes D)sites of protein synthesis E)contains the chromosomes 148. nucleus Answer: e Level: 1 149. ribosomes Answer: d Level: 1 150. lysosomes Answer: c Level: 1 151. mitochondria Answer: b Level: 1 152. centrioles Answer: a Level: 1 For questions 153 to 157 match the followi ng descriptions with the appropriate metabolic pathway. A)aerobic respiration B)anaerobic respiration 153. occurs without oxygen Answer: b Level: 1 154. uses the citric acid cycle and electron transport chain Answer: a Level: 1 155. ccurs in the mitochondria with oxygen Answer: a Level: 1 156. converts pyruvic acid to lactic acid Answer: b Level: 1 157. produces carbon dioxide, water, and ATP Answer: a Level: 1 For questions 158 to 162 match the following cell organelles with the appropriate definition or description. A)organelle where subunits of ribosomes are manufactured B)an organelle of locomotion C)may or may not have ribosomes attached D)small vacuoles containing oxidative enzymes E)package materials for secretion from the cell 158. endoplasmic reticulum Answer: c Level: 1 159. Golgi apparatus Answer: e Level: 1 160. nucleolus Answer: a Level: 1 61. peroxisomes Answer: d Level: 1 162. flagellum Answer: b Level: 1 For questions 163 to 167 match the following stages of the cell cycle with the appropriate description. A)chromosomes align along equator B)cytokinesis is completed at the end of this phase C)time between cell divisions D)chromatin condenses and nucleoli disappear E)chromosomes begin migrating towards poles of the cell 163. interphase Answer: c Level: 1 164. prophase Answer: d Level: 1 165. metaphase Answer: a Level: 1 166. anaphase Answer: e Level: 1 167. telophase Answer: b Level: 1 For questions 168 to 172 match the following molecules with the appropriate escription. A)structural RNA of ribosome B)mRNA containing introns C)protein that is converted to an active enzyme D)all triplets required to code for synthesis of a protein E)three adjacent nucleotides in mRNA 168. pre-mRNA Answer: b Level: 1 169. proenzyme Answer: c Level: 1 170. gene Answer: d Level: 1 171. ribosomal RNA (rRNA) Answer: a Level: 1 172. codon Answer: e Level: 1 For questions 173 to 176 match the cells described with their most abundant organelle. A)mitochondria B)centriol es C)peroxisomes D)lysosomes E) Golgi apparatus 173. white blood cell, a phagocyte Answer: d Level: 2 174. mucus cell (secretes mucus)Answer: e Level: 2 175. liver cells that detoxify hydrogen peroxide Answer: c Level: 2 176. cardiac muscle cells (require large amounts of ATP) Answer: a Level: 2 For questions 177 to 184 match the type of cell division with the appropriate description. A)mitosis B)meiosis C)both mitosis & meiosis 177. Responsible for tissue growth and repair Answer: a Level: 2 178. Resulting cells are haploid Answer: b Level: 2 179. Occurs only in testis and ovary Answer: b Level: 2 180. Daughter cells genetically identical to mother cell Answer: a Level: 2 181. DNA replication occurs only once Answer: c Level: 2 182. Tetrad formation occursAnswer: b Level: 2 183. Cytokinesis occurs only once Answer: a Level: 2 184. Crossing over Answer: b Level: 2 For questions 185 to 189 match the following terms relative to theories about cell death and cell aging to the most appr opriate description. A)portions of DNA are lost over time resulting in cell death B)loss of the energy source in the cell C)genes that turn on late in life that cause cell death D)after a certain amount of time or cell divisions, the cell line dies E)atoms or molecules with unpaired electrons that may damage cells 185. Cellular clock Answer: d Level: 1 186. Mitochondrial damage Answer: bLevel: 1 187. DNA damage Answer: a Level: 1 188. Free radicals Answer: e Level: 1 189. Death gene Answer: c Level: 1 Fill in the Blank 190. The predominant lipid in the cell membrane is a _____________. Answer: phospholipid Level: 1 191. Glycolipids would contain both lipids and _____________. Answer: carbohydrates Level: 1 192. The _____________ contains the genetic information of the cell. Answer: nucleus Level: 1 193. Cytosol is part of _____________. Answer: cytoplasm Level: 1 194. The centrioles are found in a zone of cytoplasm close to the nucleus called the _____________. Answer: centrosome Le vel: 1 195.At the base of each cilium is a structure called the _____________. Answer: basal body Level: 1 196. The shaft of a flagellum contains _____________ microtubule doublets around its periphery. Answer: nine (9) Level: 1 197. _____________ is the force required to prevent the movement of water by osmosis across a semipermeable membrane. Answer: osmotic pressure Level: 1 198. In _____________, ions or molecules move in opposite directions. Answer: counter transport Level: 1 199. _____________ is the sum of catabolism and anabolism. Answer: metabolism Level: 1 200. According to base pair rules, adenine pairs with _____________ in DNA replication.Answer: thymine Level: 1 201. In females, the sex chromosomes look alike and are called _____________. Answer: X chromosomes Level: 1 202. The term for â€Å"programmed cell death† is ______________. Answer: apoptosis Level: 1 Essay Questions 203. Explain what would happen to a cell in each of the following events: a. A cell los t its nucleus b. All the lysosomes ruptured c. The phospholipids in the cell membrane were dissolved d. The cell began losing its mitochondria e. The transfer RNA molecules are selectively destroyed by viruses. Answer: (a) Without a nucleus cells are unable to synthesize mRNA and so cannot complete protein synthesis.Lack of a nucleus also prevents cells from duplicating themselves. A cell without a nucleus will have a short life span and eventually die. (b) Rupture of the lysosomes releases hydrolytic enzymes that begin to digest the cell and kill it. (c) If the phospholipids in the cell membrane are dissolved, the membrane loses its integrity and would no longer function as a selective barrier. (d) Loss of mitochondria reduces the capacity of the cell to generate energy. (e) If transfer RNA molecules are selectively destroyed, protein synthesis would be inhibited as no amino acids would be brought to the ribosomes.Level: 2, 1 204. Adriamycin is a chemotherapeutic drug that binds to DNA and blocks messenger RNA synthesis. Explain why this drug is fatal to a cell. Answer: When adriamycin blocks mRNA synthesis, it also blocks further protein synthesis in those cells. These cells cannot synthesize additional proteins (structural or enzymatic) that they might need. They will soon be unable to function, and they will die. Level: 2 205. Lysosomes remove nonfunctional cell parts. Explain how this function is important to the overall health of the cell. Answer: Nonfunctional cell parts take up valuable space in the cell.They are also composed of molecules that the cell might be able to recycle. It is healthier for the cell to be able to eliminate these nonfunctional parts and possibly reuse some of the molecular components of those parts. Level: 2 206. The cell is compartmentalized by the presence of organelles. What advantage does compartmentalization give to the cell? Answer: Compartmentalization enables cells to specialize internally. By partitioning the interior o f a cell, different functions can be undertaken in different structured compartments within the same cell.This property allows cells to do more than one thing. Level: 2 207. Describe the relationship among ribosomes, ER, the Golgi apparatus, and exocytosis. Answer: Ribosomes are the sites of protein synthesis. Some of the proteins have leader sequences on them, which allow them to be inserted into the cisternae of the endoplasmic reticula to which the ribosomes are attached. The proteins can travel in the endoplasmic reticulum to the Golgi apparatus, where they can be modified and packaged for secretion. Vesicles break off from the flattened membranous sacs of the Golgi apparatus.Some of the vesicles carry proteins to the plasma membrane, where the proteins can be secreted from the cell by exocytosis. Level: 2 208. You work for the I. M. the Best Drug Company. Your latest assignment is to design a drug that interferes with translation in cells. You decide the easiest way to do this is to have your drug target those organelles and molecules involved in translation. List the potential targets of your new drug. Answer: Potential targets include: large and small ribosomal subunits, messenger RNA, transfer RNA, any enzyme needed in translation. Level: 2

Analysis of a Play Essay

In Edward Bok Lee’s â€Å"El Santo Americano,† a professional wrestler kidnaps his wife and child as he drives to Mexico, hoping to reinvent himself and keep his family together. Clay is a disgraced professional wrestler who drives his wife and son with him to Mexico. There, he hopes to reinvent himself as a wrestler, and not be taken as a joke. He also hopes to improve his failing relationship with his family. It is revealed shortly into the play that Clay has in fact taken his wife and son by force, when Evalana tells him to stop so she can take a bathroom break, and Clay says â€Å"if I stop, you’ll try to run again. † He also has brought a gun with him. As the story progresses, Clay pulls over, giving Evalana the â€Å"opportunity† to run away, to which she promises she won’t. Clay then gives a long monologue revealing his wrestling life, including when he had finally won a match and the audience actually cheered him on, appreciating a â€Å"real† match as opposed to â€Å"so much phoney bullshit (they had seen) through the years. †More importantly, during the monologue, Clay reveals that he had won to give his wife and son something to believe in, and so his son could for once not â€Å"see his daddy get beat time and again. † During the long monologue, Evalana temporarily runs off, and Clay aims the gun at himself, eventually just putting it into his mouth. Evalana eventually reappears, and gives a monologue of her own. She tells of a family trip she went on to Disneyland when she was about their son Jesse’s age. Along the way, her father woke the family up in Arizona, so they could see a big dam at night. It was during that time that she was fascinated by a rainbow she saw at night. The next night, while the family was camping out, Evalana saw a distant town that enchanted her, â€Å"shining with tiny stars that weren’t really stars, surrounded by rainbows that weren’t really rainbows. † She reveals that she imagined she was born in that town, and that was the place the family was heading to instead of Disneyland. Following Evalana’s monologue, it is revealed that Jesse has driven off without them. Clay and Evalana look at each other, the gun still in Clay’s mouth, and Evalana proceeds to remove the gun from his mouth, and aims it at him. Overall, this was a successful play which had conflicts between the characters, and ended in a twist in which their son abandons them in the desert. The play reveals the tragedy of a man who wants to prove himself to his family, and his own son abandons him and leaves both him and his wife stranded in the end. I liked the story and the tensions in this play, as well as the ending I did not expect coming. However, I did not like the long monologues told by both Clay and Evalana, which I found hard to follow. In addition, the fact that no sentences began with capital letters made the play hard to read. I feel like the play could have improved if it did not have such long monologues, and shorter bits of character dialogue with each other.

Eassay Essay Example | Topics and Well Written Essays - 750 words

Eassay - Essay Example Thus, operating with autonomy and using generic information handling as well as logging systems familiarizes one with ECC roles. In relation to the information provided above, ECC is defined as a physical location associated with coordination of information as well as resources with the goal of supporting incident management activities. From this definition, one can deduce that ECC need to be located in appropriate location in addition to being organized into key functional disciplines. For the members to make right decisions therefore, they need to be informed about each discipline of ECC. A wide scope of knowledge makes the ECC members confident of the decisions they make regarding any emergency incident. In tandem with this assertion, all personnel of ECC need to undergo training in order to increase their ability in performing critical tasks as well as making critical decisions. The design of ECC plays a significant role in defining its role in the management of emergency incidents. The ECC staff needs to be knowledgeable in addition to having skills for performing the assigned tasks. Essential functions of ECC need to be identified in order to come up with specific arrangements for performing a specific function. Identification of a specific function also reduces cases of confusion in ECC operations. Additionally, delegations of authority need to be made in order to handle an emergency. In relation to this assertion, ECC operations need to be carried out within a given timeframe through the aid of a clear chain of command. Thus, coming up with a specific design of ECC in addition to allocating timeframe for essential functions of ECC will make the members of ECC make the right decisions at the right time. Additionally, the selection of essential functions will increase the members’ confidence in handling specific emergency incidents. Location of ECC in a given areas requires the

Development of Mongolia in Mining Sector Essay Example | Topics and Well Written Essays - 1750 words

Development of Mongolia in Mining Sector - Essay Example pag.). This paper is intended to review the impact the booming mining industry makes on the overall economic performance of Mongolia, as well as the major opportunities and challenges faced by the sector, which inter alia would determine its future. The paper is organized in three main sections, the first of which provides accounts of the overall size, type and peculiar characteristics of Mongolian economy; the second provides a brief overview of the Mongolian mining sector; while the third section attempt an insight into the broadening horizons of Mongolia’s mining industry. Introduction to Mongolian Economy Following the dissolution of the USSR, Mongolia’s economy experienced both deep recession due to natural disasters and political inaction, and more or less noticeable growth, because of the economic reform, which included free-market orientation and extensive privatization of the dominant state sector (CIA, n. pag.). However, the massive livestock losses caused by severe winters and draughts, compounded by falling prices for the primary sector exports and widespread opposition to the privatization process, resulted in fairly anemic GDP (Gross Domestic Product) growth; between 2004 and 2008, the GDP growth was nearly 9 percent on average, mainly due to new gold production, as well as to high copper prices (CIA, n. pag.). As of 2008, the Mongolian economy suffered both a soaring inflation rate – actually the highest inflation rate in over a decade, reaching almost 30 percent – and an external shock caused by the global financial crisis, with a sharp drop in commodity prices, hence greatly slashed government revenues (CIA, n. pag.). A 236 million-dollar stand-by agreement was reached with the International Monetary Fund in 2009, which assisted the country to emerge from the crisis (CIA, n. pag.). Because of the harsh weather during the winter in 2009 – 2010, a massive loss of livestock occurred once again – this time over 20 % of the total number – doubling the meat prices and consequently shrinking the GDP by 1.9 percent. In 2010, the economy growth was 6.4 percent, while in 2011 – 17.3 percent; these results were mainly obtained by commodity exports in the neighboring countries, on which the Mongolian economy heavily relies (CIA, n. pag.). For example, Mongolia purchases 95 percent of the imported petroleum products and substantial portion of its electricity imports from Russia, while China receives over 90 percent of Mongolia’s total exports (CIA, n. pag.). Besides agriculture, which comprises production of wheat, barley, vegetables and forage crops, as well as horses-, sheep-, goats-, cattle-, and camels-breeding, the Mongolian economy’s main industries include construction, production of construction materials, mining (coal, copper, molybdenum, tin, gold, uranium, etc.), production of food and beverages, as well as processing of animal products; according to data of 2010, electricity production amounts to 4.313 billion kWh, whereas electricity imports are 262.9 million kWh (CIA, n. pag.). As of the same period, the overall industrial production growth rate is estimated at 37.3 % (CIA, n. pag.). According to 2011 data, Mongolia’s GDP is estimated at 13.28 billion dollars. Agriculture contributes 12.9 % of the total GDP, the

Financial Analysis on Nokia from 2008 to 2009 Research Paper

Financial Analysis on Nokia from 2008 to 2009 - Research Paper Example The Working Capital ratios indicate how well the company is able to manage its working capital. "The asset management ratios are also known as working capital ratios or the efficiency ratios. The aim is to measure how effectively the firm is managing its assets." (Netcom, n.d.)The following are some of the working capital ratios which indicate the efficiency of the company in managing its working capital. Liquidity ratio is defined "as a class of financial metrics that are used to determine a company's ability to pay off its short-term debts obligations.Generally, the higher the value of the ratio, the larger is the margin of safety that the company possesses to cover short-term debts." (Investopedia, 2009) The above table indicates that the company has efficiently managed its working capital during the year ending September 2009 as compared to the year 2008. Nokia is maintaining a comfortable current ratio and the current ratio of 1.5 implies that the company has sufficient current assets situation which will enable the company to meet its current liabilities without any problem. However, the company has increased its long-term debts during the year 2009 with the result that there is an increase in this ratio. This implies that the company will incur additional interest costs on borrowed funds. The cash flow to debts situation has therefore moved to an adverse situation in 2009 as co mpared to the earlier year. In 2008 the cash flow position of the company was comfortable enough to settle the short-term and long-term debts in just 7 months. Whereas, with the increase in long-term debts and the cash flow from operations it would take approximately 3.8 years for the company to settle the debts. This is not a good position from the equity shareholders' point of view. However, the purpose for which the long-term funds were mobilized is to be ascertained for a proper justification for the increase in debts. The number of days sales outstanding is another working capital ratio that indicates the efficiency of the working capital management of the company. This ratio has changed from the previous year figure of 70 days to 83 days. This implies that the company has not been able to collect the outstanding accounts receivable as efficiently as it was doing in 2008. However, the increase in credit sales might be another reason for the change in this ratio. When the company has offered more liberal credit terms to its distributors and dealers in order to boost its sales, that situation might have resulted in increased debtors and the consequent increase in the number of days sales outstanding. A weaker sales environment is indicated by the increase in the number of days inventory expressed as a ratio to the cost of goods sold. There is an accumulation of inventory due to lower sales which is indicated by the change in this ratio. Â  

N.A.F.T.A Assignment Example | Topics and Well Written Essays - 1000 words

N.A.F.T.A - Assignment Example Moreover, the policies also focused upon codifying broad assortment of agreements related to textile, agriculture, telecommunications, auto trade, intellectual properties, flexibility of workers and environmental policies (Ford, â€Å"A brief history of NAFTA†). Thesis Statement The discussion would aim to analyze the purpose of NAFTA. It would also attempt to provide an insight into the history of NAFTA along with ascertaining the favorable as well as unfavorable outcomes on the US and world economy. A Brief History of NAFTA NAFTA was established in the year 1994 for the purpose of trimming down the costs related to trading, raising business funds and most significantly promoting financial growth among Mexico, Canada and the US. The agreement i.e. NAFTA which was duly signed by the different leaders of the participating nations was ratified by the Congress of the US in the year 1993. It was observed that the agreement proved to be quite controversial as most of the manufactur ing industries as well as the makers of agricultural commodities belonging to the US faced the threat of losing the business market by competing with the Canadian along with Mexican business firms due to their lower cost arrangements (Ford, â€Å"A brief history of NAFTA†). ... Additionally, the fundamental purpose of NAFTA is to ensure and maintain a smooth flow of goods as well as services by making substantial investments. Moreover, the agreement aimed to provide each of the participating countries the prominence in terms of substantial favored trade in the business market. With regard to the purpose of NAFTA, it has been observed that the agreement encompassed certain important areas which comprised the abolition of non-tariff associated trade barriers, augmentation of financial investments and reduction of environmental issues. Moreover, the agreement also entailed segments such as trimming down the tariffs and developing the trade rules such as dispute settlement methods. However, on the basis of the above discussion, it can be stated that the chief aim of NAFTA is to generate a situation of free trade amid the nations of Mexico, Canada and the US by the exclusion of tariffs along with other trade barriers. The agreement i.e. NAFTA can be considered a s a major initiative owing to the different imperative purposes of the trade policies (Rosson, Benson, Moulton and Sanders, â€Å"The North American Free trade Agreement and U.S. Agriculture†). Effects of NAFTA on US World Economy NAFTA was found to pose significant effects upon the world economy of the US. Due to the implementation of NAFTA, the trade relations between the nations i.e. Mexico, Canada and the US broadened substantially. It becomes necessary to be stated in this context that the supporters of NAFTA declared the agreement to be a successful one for supporting the producers of the US by generating a free trade amid the participating nations. Moreover, the agreement benefited the

A Great Deal of Stress Essay Example | Topics and Well Written Essays - 1750 words - 2

A Great Deal of Stress - Essay Example I recently uncovered that one of our members was selling these very same exams via the school website to people outside of the BSP community. The fact that people outside of our program were receiving these past examination papers did not bother me much. What really disturbed me was that the culprit was profiting from a resource that is normally free. It was a difficult decision to make because I was personally close to the person doing this. I was in a dilemma – I also wanted to protect the integrity of the program along with all of its benefits. I could not even seek help from others. It was a question of making a value-driven decision, which potentially puts our friendship at stake. However tough it may have been, I finally chose to go by what my conscience told me. I brought it to the attention of the Director and the Assistant Directors. Appropriate disciplinary action was taken and there were no major implications to the program and the organization. If I had to deal with a similar circumstance in the future, I would still have made the same choice, of abiding by the principles and values that I have earned through my upbringing. While it may be easy to decide, on the contrary, it will be strongly against my core values and principles. And since I have always lived by and made principle-driven decisions, I have not felt regret or resentment having made such a decision, because I am aware that with all conscience, I am doing what I ought to do.

Financial Markets and Bank Management Essay Example | Topics and Well Written Essays - 1000 words - 1

Financial Markets and Bank Management - Essay Example The banks are faced with credit risk that involves change in net asset value due to changes in the ability of the counter-party to meet the contractual agreements (Thomas 2005). Performance risk includes the possible loses that may emanate from dishonest employees while operational risk include costs such as inability to meet regulatory requirements or settlement failures (Rao 1999). The bank’s net profit margin for 2012 was negative due to lack of growth of the non-customer interest income. The net profit margin was positive in 2013, but the current low interest environment prevailing in the market will continue maintaining the net interest income growth rate low. This means that the bank should divest the low-yielding non-core assets like investment securities portfolios in order to scale up the bank’s net interest margin. The operating margin was too low to generate substantial increase in net profits in 2013. The return on invested capital growth rate stagnated thus demonstrating imprudent investing strategy due to low returns from the non-core business segments. The improvements in return on assets and return on equity were low while the leverage position declined slightly due to injection of additional capital through rights issue. The stringent regulatory environment forced the bank to improve on its capitalisation and implement measures of lowering its leverage. Some of the measures implemented include the rights issue and reduction in the risk-weighted assets (RWAs) (Gregory 2011). Barclay’s loan to deposit ratio stood at 110 percent in 2012, but the ratio declined to 101 percent in 2013. The deposits were almost equal to the customer loans thus demonstrating increased prudence in retail lending. The investment banking business segment is funded by a high proportion of liabilities. The bank should have sufficient liquid assets to withstand any market and internal stresses (Mehta and Fung

Individual Case Analysis Essay Example | Topics and Well Written Essays - 1250 words - 1

Individual Case Analysis - Essay Example The precise ways in which a brand adds value can be recognised through gaining knowledge about the sources of brand equity (Keller, n.d.). In relation to the provided case scenario related to Red Bull, it can be comprehended that the company focused on the aspect of creating brand awareness as well as establishing their brand image. These two facets are the key sources of their brand equity. Development of the source of brand awareness has facilitated Red Bull to develop its brand equity. Red Bull has especially focused on the element of brand recall. Brand recall refers to the customers’ capability to distinguish a particular brand within different circumstances (Keller, n.d.). . With this notion, Red Bull concentrated on designing its products attractively. Moreover, within its growth strategy the company entered new markets by taking a slow method to optimize the anticipation as well as buzz from the company (Das, 2012). This was a key strategy to build brand equity of the company. Moreover, it focused on inventing the aspect of functional energy within the beverage category segment which facilitated it to create a distinct brand image among the customers. It also focused on above-the-line strategy with regard to marketing aspect to draw the attention of its customers. It created an eye-catching logo of two red bulls and a yellow sun. The animated message reinforced the value of Red Bull as a drink that gives an individual ‘wings’ i.e. it energizes the person. This has been the main notion conveyed by the company to its consumers which is the key source of brand equity for the company (Kumar & Robert 1988). Incorporation of a distinct flavour and packaging along with positioning were the other major facets for the company that facilitated it to develop its brand equity. In terms of packaging, under the logo of the company, highlighting the aspect of energy drink was a major consideration by the company. Moreover, it positioned the brand a s revitalizing substance for body and mind. The product started to create a buzz as a mixer element in varied markets, however, the company primarily attempted to go beyond this aspect and appeal to a broader section of consumers especially the young ones (Rehman, 2011). The company also concentred on participating in different events and sporting activities which substantially boosted up its name and logo, which are the imperative elements for success of a company in terms of augmenting its brand equity. Q:2. Analysis of Red Bull’s Marketing Programs in Terms of how it contributes to the Brand’s Equity Red Bull is using uncongenial adverting policies, as it has uniquely positioned itself in the beverage industry. Its distinctive positioning has allowed it to detain a significant amount of brand recognition in different nations. The company focused on creating a sense of mystique amid its customers through its marketing program. It initially focused on word-of-mouth tr aditional method of advertising technique, however, it wanted to spread the awareness of the brand even more (Collins & Rusktad, 2008). Red Bull’s promotion strategies had facilitated it to flourish in the facets of market share, income, and units sold (Sarah, 2009). Exceptional positioning strategies were focused on by the company by targeting high-school and colleges going

Criminal Law 2000 word assessment - part 2 Essay

Criminal Law 2000 word assessment - part 2 - Essay Example Kirk says that he tried to sound the car horn so that they would all jump out the way but that the horn failed to work. Advise Kirk in relation to charges of s18 Offences Against the Person Act 1861, with s20 in the alternative. Advise Sally in relation to s20 Offences Against the Person Act 1861 with s47 in the alternative. Do not discuss any other offences. Under the Offences Against the Person Act 1861 assaults are determined by reference to sections 46, 18 and section 20. Prosecutors will assess the level of the charge in accordance with the seriousness of the injuries of the victim as well as the intention of the defendant. The lowest of the charges for assault covered by the OAPA 1861 is a s47 assault. This will be charged in circumstances where the victim sustains actual bodily harm1. Section 47 defines actual bodily harm as any hurt that has been calculated to affect the health or comfort of the victim. Under this heading, there is no requirement for the hurt to be permanent but it has to be more than transient and trifling2. Offences charged under this section are classified as either way offences, which means that the matter can be tried in the Magistrates court or the crown court. The decision for the matter to be referred to the crown court is usually based on whether the prosecution determines that the sentencing powers of t he Magistrates would be inadequate. Cases where a s47 have been charged include incidents where the victim has lost or broken a tooth, has suffered a temporary loss of sensory functions which could include losing consciousness3, has received a broken nose or extensive or multiple bruising. A s47 charge might also be brought for minor fractures and cuts as well as psychiatric injury4. Proof is established applying the test of recklessness5. A higher degree of injury could result in the accused being charged with a s20 assault6. Section 20

Persuasive Writing Essay Example for Free

Persuasive Writing Essay The next type of writing we will do is the persuasive essay. In this essay, you will be working to convince your reader of the rightness of your point of view on a specific topic. As I have already said, in some ways every type of writing is a form of persuasion: you are always trying to make your reader see the correctness of your opinion. In this assignment, however, you will stake out your position on a particular topic and argue forcefully and explicitly in favor of it. As always, you want to state your opinion explicitly in your thesis statement (of course, without saying, â€Å"I think that. . . .†). As always, you also want to pick a topic that is fairly focused, narrow, and specific: pick a topic that you can adequately discuss in four to five paragraphs. I will say it again: it is always better to say a lot about a small topic than to try to say a little bit about many aspects of a large topic. (For those who are counting, that is the 3,248th time I have said that this year.) Use the first paragraph to state and fully explain your thesis. The rest of your essay should then be the marshalling of evidence in support of your thesis statement and an explanation of and commentary on your evidence. Facts are necessary to support your thesis, but by themselves facts are not enough. You need to explain and comment on them fully; show how these facts support your view and not the view of the opposing side. Try to find three or four really strong pieces of evidence to support your opinion. There is no way you can say everything or think of every point; choose the strongest evidence you can. While arguing in favor of your position, you should also include arguments against the opposing view. For example, if I am writing about the wrongness of capital punishment, I should also include arguments showing the wrongness of arguments made in favor capital punishment. Try to anticipate the other side’s arguments. That will show you are thinking and will also strengthen your argument. In general, it is best to work from your weakest to your strongest argument. As usual, conclusions are difficult. End with a strong, powerful concluding paragraph that brings together your various ideas but does not merely restate them. Certainly do not end by saying something like, â€Å"For all these reasons . . . .† I have listed below a few sample thesis statements and a number of possible topics. Please do not be  limited by my suggestions. As with any piece of writing, you will do the best job if you write about something you care about. I will give you a sample essay. Your essay should be 1-2 pages typed or 4-5 sides handwritten, double-spaced either way. The essay is due Tuesday, 30 January. It is worth 100 points. We will work on the essay in class; you can always show me drafts. Do your best. SAMPLE TOPICS the dress code (or, better yet, some more significant and meaningful issue at school!) your allowance or curfew or some other family issue gun control, abortion, capital punishment (or any other political issue) your view on dating or relationships advocating for a particular religious or spiritual practice: for example, meditate everyday the need for more late-night activities for teenagers the war in Iraq of course, anything else you feel strongly about SAMPLE THESIS STATEMENTS Limiting civil liberties is not an appropriate way to keep this country safe from terrorism. Capital punishment is an unjust and immoral way to punish criminals. A vegetarian diet is a sensible and meaningful response to world starvation and environmental destruction. The dress code provides a meaningful way to minimize the economic competition between students and unite them in their common academic purpose. A vegetarian diet is a sensible and meaningful response to world starvation and environmental destruction. So many Americans are often caught up with finding the â€Å"perfect† diet. While such a diet does not exist, a vegetarian diet provides significant health, environmental, and political benefits. Choosing such a diet is a simple but significant way to make a real difference in one’s own life and the world. First of all, a vegetarian diet is far more healthful than the traditional  American diet that emphasizes meat. A meat-free diet is higher in fiber, lower in saturated fat, and richer in a wide range of vitamins and minerals than a meat-based one. While we do hear conflicting evidence about the various health claims of different diets, nutritionists and scientists seem to agree that a diet rich in fruits and vegetables provides the greatest health benefits. Some people might say that a vegetarian diet is boring: quite the contrary. Compared to the relatively few kinds of meats and ways to prepare them, there are scores of vegetables, fruits, grains, and legumes and almost countless ways to prepare them. A meat-based diet also puts far too much protein into the body, taxing the kidneys and wasting expensive food. As it is, Americans eat too much protein; eating a vegetarian diet is one way to reduce our intake of excessive and expensive protein. Eating a diet based on fruits and vegetables also creates less environmental havoc than a meat-based diet. Raising the animals necessary for the traditional meat-laden diet requires large amounts of land, mountains of processed feed, and the disposal of tons of waste. But a family of four could, if necessary, live for a year off the fruits, grains, and vegetables produced from a few acres of land. And, once the crop is taken, there are few or no ill effects. If the agriculture is done organically, vegetarian eating has even fewer harmful effects upon the land. In an age of diminishing arable land and resources and increasing populations, we need to find ways to get the most nutrition from our land use. A vegetarian diet provides such efficiency. Finally, a meat-rich diet consumes many more scarce resources than a vegetarian diet. It takes about 800 pounds of cattle feed to produce one pound of beef. In a world in which nearly one-fourth of the planet’s population is malnourished or starving, a meat-based diet is simply a luxury we can no longer afford (if we ever could have). In good conscience, it only makes sense to eat lower on the food chain – as we do with a plant-based diet. If everyone in the world ate a vegetarian diet, there would be an immediate surplus of food available to feed people at far lower cost and with wiser use of precious resources. In this way, vegetarianism becomes a moral choice. For reasons of politics, environment, health, and justice, vegetarianism is the only intelligent and compassionate choice in a world of scarce resources and increasing population. It may take some getting used to, but the benefits and rewards of a vegetarian diet – for the planet, the self, and the human race – far outweigh whatever minimal sacrifice may be involved. sentence in bold: thesis statement underlined sentences: topic sentences for each paragraph

Computer Supported Cooperative Work (CSCW)

Computer Supported Cooperative Work (CSCW) Abstract- In the Computer Supported Cooperative Work (CSCW) domain, researchers have always wondered about which principles and models to adopt for the development of collaborative applications capable to really meet the needs of their users. However, these users requirements are unpredictable and depend on several task or environment-related factors. Integrated collaborative environments are rarely open, extensible and reconfigurable enough so as to meet these requirements. This paper presents an environment, called LEICA (Loosely-coupled Environment for Integrating Collaborative Applications), allowing the integration of existing cooperative applications. LEICA adopts a loosely-coupled integration approach which is based on Web services Services technology, an event notification system, and the definition of Collaboration Policies to control the interactions among integrated applications. LEICA allows different functionalities of existing applications to be dynamically combined and controlled, enhancing therefore the flexibility. Through a case study we show how LEICA was successfully used to integrate three collaborative applications: a co-browsing tool, an instant messaging tool and a VoIP conference controller. Index Terms-Collaborative work, integrated collaborative environments, web services. INTRODUCTION Advances in networking and computing technologies, combined with the fact that companies and work teams are becoming geographically distributed, have created increased a need for communication technologies to ease distance collaboration among distributed individuals (virtual work teams). This leads to the appearing of the so-called Integrated Collaboration Environments (ICEs), having as main goal to integrate different collaborative applications together into a single easy-to-use operational environment [1]. Users needs are very frequently unpredictable and depending on several emerging factors, including the size of the workgroup, the collaborative activities to be accomplished, the intensiveness of the required communications, the coordination policy and the communication needs of the workgroup. Therefore, the possibility of dynamically integrating new functionalities to the environment appears as an important characteristic for collaborative applications [3]. Supporting the integration of new collaborative functionalities reflects how flexible the environment is while responding to unpredictable users needs. We can define this characteristic as integration flexibility that denotes the ease with which an ICE can be its functionalities in response to the users needs. Nowadays one of the main problems of ICEs is that their lack of integration flexibility and as consequence various users decide to set-up their own environments composing different collaborative applications executed independently. In this case, each application is completely isolated from others, without any possibility of coordination among them. This lack of integration can lead to a loss of control from the part of the user, since the operation environment is particularly artificial. Promoting the integration flexibility of ICEs could bring significant benefits to users, allowing different functionalities of existing applications to be dynamically combined and controlled (enhancing therefore the flexibility itself). For instance, a whiteboard application can be integrated with an instant messaging application in such a way that whenever a user joins an instant messaging room, he is automatically logged into the same whiteboard session, instead of been forced to manually login into a session of each one of these collaborative tools. Another case could be the integration of a distributed game and an audio conference application. Whenever a user avatar enters a level/place into the game, his is logged into the audio conference session associated to that level/place, so that the users can online discuss with each other. In order to achieve the integration of existing collaborative applications without having to deal with their low-level features, this work presents LEICA, a Loosely-coupled Environment for Integrating Collaborative Applications. Relying on Web services Services (WS) technologies and an event notification system, different collaborative applications can interoperate by exchanging information within the context of a global collaborative session. The loosely-coupled approach proposed by LEICA overcomes a key problem usually related to integration environments it does not require a true semantic integration of applications. Accordingly, it supports further integration possibilities, such as the integration of third party applications, enhancing, thus, flexibility. LEICA also offers flexibility in the level of the integration semantics. Based on Collaboration Policies to control the interactions between integrated applications, LEICA provides means to define how the collaboration activity supported by one collaborative application will be affected by information received from other collaborative applications. In practice, these collaborative applications interact through the notification of events which may lead to performing specific action(s) in some of these applications themselves. As we will explain later in detail, we think that once a collaborative session has been configured, the use of LEICA can improve users productivity by reducing the application-related administrative tasks, focusing precisely on the collaboration activity itself, and all that by just by interpreting the rules stated for a particular session, all this in function of some pre-established policy rules (also to be explained in detail later). In this way users will find a more natural collaboration environment from the users point of view. In order to illustrate the usability of LEICA in real-world conditions, this paper presents a case study that demonstrates the capability of LEICA to integrate collaborative applications. In this case study, LEICA was successfully used to integrate three collaborative applications: a co-browsing tool, instant messaging tool and a VoIP conference controller. The paper is structured as follows. Section II presents related work regarding the integration of CSCW systems. Section III overviews the general integration approach proposed by LEICA. Section IV explains how to specify Collaboration Policies. Section V presents the LEICAs architecture, detailing how to integrate applications in practice. Some implementation issues are considered in section VI. Section VII describes a case study illustrating the use of LEICA. Finally, in section VIII we draw some conclusions and presents directions of future work. RELATED WORK There are several works oriented to improving integration flexibility of collaborative environments. In this context, four main approaches can be identified: user-tailorable solutions; CSCW toolkits; middleware based solutions; and platforms for integration of heterogeneous collaborative systems. User-Tailorable Solutions As stated in [2], different definitions of tailorability can be found in the literature. Most of them focus on user tailorability ([3], [4], [5] [6]) defining that a tailorable application can be adapted and modified by its own users in order to meet their different requirements. In CSCW, tailorability must focus on the requirements of the group task and of the organization, in which the CSCW system is used [5]. Actually, tailorability is one of the main concerns of groupware development methods. For example, application of participatory design methods ([7] [8]) has been proposed in order to approach the user involvement during groupware development, augmenting thus the opportunities for tailoring. According to [6], tailoring can be supported in three different levels: customization, selecting among a set of predefined configuration options; integration, linking together predefined components within or between applications; extension, improving the implementation by adding new program code. Most of user-tailorable groupware tools support only the customization or integration level (e.g. [2] [9]). Note that the integration level supposes that the functionality to be integrated has been pre-developed and is available somewhere [6]. Only at the extension level users would be able to integrate new functionalities, even if they have not been anticipated by developers at design time. A method frequently used for supporting tailoring at the extension level is the component-based tailoring. For example, in [10], components are implemented using Flexibeans (an extension of the Java Beans model) and end-users tailor the system using a composition language. In [11], end-users may assemble components into larger composite components using the visual representation rather than writing lines of code. However, even at the extension level the integration flexibility is partial as the integration of existing collaborative systems or groupware would require them to be redesigned according to the system architecture. CSCW Toolkits CSCW toolkits ease the implementation of CSCW systems by providing reusable components and behaviors designed to be applicable in a range of circumstances [12]. The need for flexibility and tailorability in CSCW toolkits is well acknowledged. The Neem Platform [13] offers a generic (application-neutral) evolvable framework upon which socially and culturally aware applications are developed. Flexibility and extensibility in Neem result from its foundation on a core architectural coordination model [13]: decoupled components interact indirectly through message exchanges. Intermezzo [14] is a collaboration support environment supporting the coordination information sharing, offering fluid interactions, user awareness, session management and policy control. It addresses dynamic flexibility [12] by allowing applications to adapt not just their own behavior, but also the behavior of the toolkit in reacting to the changing dynamics of the world they run into. The Groupware Toolkit/Shared Dictionary (or GT/SD) toolkit [15][16] has been developed to support rapid development of groupware, focusing mainly on networking and data sharing aspects. GT/SDs extensibility is based on its modular design, which allows adding or modifying behavior by replacing or wrapping different components. Toolkits may represent an interesting solution for helping the development of CSCW systems, as they promote the reuse of components. But in general, CSCW toolkits offer a limited set of functionalities or they are target for some specific kind of domain. Besides, to reuse components of the toolkit, developers often need to implement very specific details of the toolkit in order to adapt it to the application needs [16][17]. Middleware based solutions The integration of heterogeneous applications has been a widely investigated subject, mainly in distributed systems area. General integration solutions based on middleware, like CCM (CORBA Component Model), .NET and Enterprise JavaBeans have been developed. Moreover, integration solutions associated with specific domains have also been proposed, such as Enterprise Application Integration systems [17][18]. The emergence of Web services WS has also led to the development of general solutions for integration of distributed applications, due mainly to the use of open standards. In the CSCW domain, some middleware-based solutions have been proposed. Dustdar et al. [18][19] discuss the importance of using Web services WS in order to provide collaborative application interoperability. But in order to be integrated, collaborative applications must originally support Web servicesWS. Even if Web servicesWS represent an emerging software trend, only a limited set of collaborative applications are currently supporting these technologies. As an enhancement to traditional middleware, some SOA (Service Oriented Architecture) solutions have also been proposed. For example, WGWSOA [19][20] uses Web ServicesWS as an access interface in order to support the reuse and the interoperability of different collaborative services. But an important drawback of WGWSOA is that collaborative services must be developed following the respective middleware architecture. It is also important to note that like WGWSOA, most middleware based solutions present technical responses to the so called syntactic interoperability [20][21]. They provide mechanisms allowing applications to communicate and interact through information exchange. But according to [21][22], the integration concept goes beyond the possibility of sharing and exchanging specific information. Applications must agree upon the meaning (or the semantics) of these exchanges. In other words, integration solutions should provide means for defining integration semantics. Thus, interoperability can be seen as a requirement for integration. The EcoSpace Project [22][23] proposes an environment that, besides being based on SOA and Web servicesWS, relies on Semantic Web technologies (WSDL-S with services ontologies) to support semantic description of collaborative services. Besides a semantic description of each service, it would be necessary a semantic description of the composition of services so as to coordinate their orchestration. However, this part of the project remains as design aspect. Moreover, using Web serviceWSs as integration technology may imply some performance loss, particularly associated to the use of SOAP (Simple Object Access Protocol) [23][24]. Luo et al. [24][25] claim that Web ServicesWS should be only used in situations which are really heterogeneous. They propose a service-oriented solution for the integration of collaborative applications that, instead of using SOAP, adopts a unified service bus (implemented through an open source Enterprise Service Bus). Platforms for integrating heterogeneous collaborative systems The latter latest approach to improve the integration flexibility of collaborative environments is to create platforms aiming specifically at the integration of collaborative applications. They focus on the integration of collaborative functionalities provided by these applications while trying to define any semantics behind integration. Iqbal et al. [25][26] propose an integrative framework based on the three-level model presented by [26][27]: the Ontological Model specifies shared objects, their relations and taxonomies; the Coordination Model specifies how interactions take place during system execution; and the User Interface Model specifies how the system is presented to the final user. Integration process consists firstly in identifying, for each collaborative application, the elements associated with these three models. Then, on each level the elements from different applications are grouped and merged when equivalent. As a result, common ontological, coordination and user interface models are generated. In spite of enabling a multi-level integration, this approach requires an internal knowledge of the collaborative applications so that their functionalities can be mapped into the three-level model. Accordingly, the integration of third party applications becomes a complex task. In order to avoid considering application internals during the integration process (facilitating the integration of existing applications), some integration solutions propose the so called loosely-coupled approach. This approach presents two main features: (i) once integrated to the environment, collaborative applications preserve their autonomy, i.e., they can still be used as standalone application; (ii) the integration environment remains independent of integrated applications, and accordingly, applications can be integrated and detached from the environment without compromising its behavior. This last feature is particularly important considering the integration flexibility aspect. In fact, in a loosely-coupled environment, the set of integrated applications must be easily modified according to users needs. Systems like AREA [27][28] and NESSIE [28][29] have proposed a loosely-coupled integration for supporting cross-application awareness. Both systems represent a collaborative environment where independent applications can share a common information space, implemented through an event notification system. Users can receive notifications of activity relevant events from different applications (executed by other users). An important aspect of these systems is the use of open Internet technologies (such as HTTP and CGI) to enable the integration of third party collaborative applications. However, the main drawback of both systems is that the integration semantics is statically defined collaborative applications are integrated so as to offer a common awareness of the whole collaboration activity. Another proposal also based on a loosely-coupled approach is the framework XGSP [29][30]. XGSP proposes the integration of audio and videoconferencing tools based on SIP and H.323 standards, as well as the integration of Access Grid applications [30][31]. In this framework, XGSP manager servers are in charge of controlling collaborative sessions. A different gateway is defined for each application type (i.e. SIP, H.323 and Access Grid applications). Using a signaling protocol based on Web servicesWS, these gateways are employed to mediate the communication between applications and XGSP servers. An important disadvantage of XGSP is the fact that, originally, it only allows the integration of application based on SIP, H.323 and Access Grid. Loosely-coupling is also inherent to the Web servicesWS based solutions presented in the previous section. Similarly to those solutions, LEICA represents an integration environment that proposes a loosely-coupled approach based on Web servicesWS technologies. Regarding the performance implications of SOAP, Alonso et al. [31][32] suggest that Web ServicesWS technologies should be used only to implement coarse-gained interactions, where the impact of the overhead associated to SOAP would be less important. Following the recommendations of [31][32], Web servicesWS are employed by LEICA for coarse-grained operations only. As it will be detailed in the following sections, LEICA defines a hybrid architecture where Web ServicesWS are applied as an initial mechanism for registering newly integrated applications, as well as for setting and starting up collaborative sessions. Then, during the execution of integrated collaborative sessions a different infrastructure is used to interconnect collaborative applications. Another important aspect concerns integration semantics. Unlike the previous solutions, LEICA provides users with the possibility to define the desired integration semantics for each collaborative session. The Integration Environment: LEICA LEICA aims at the integration of different collaborative applications, where integration semantics is to be defined according to user requirements. Before explaining the general integration approach and the behavior of LEICA, a possible scenario is presented to better illustrate the advantages of such integration. Integration Scenario An important domain where collaborative environments have been largely used is e-Learning. In particular, a CVE (Collaborative Virtual Environment) can be used to implement a 3D shared world representing a school building divided into: one entrance hall, classrooms, and teachers rooms. Different collaborative applications could be associated to each room: (i) a chat room associated to the entrance hall; (ii) a collaborative web browsing (it would enable teachers to guide students through lecture notes) and an audio conference tool associated to the classrooms; and (iii) a shared whiteboard associated to each of the teachers room. Un paragraphe pour montrer la situation: Utilisation des outils non integrà ©es, et lintà ©gration avec LEICA. With this integration semantics, whenever an avatar enters into a room, the respective user is automatically connected to the associated collaborative application(s). Besides, only authorized users should enter into private rooms (e.g. the teachers rooms with its whiteboard could be restricted to teachers). Another possible behavior specified by this integration semantics is some kind of floor coupling between the two applications used as a support for virtual class sessions. This way, it would be possible to assure that the user holding the Web browsing floor (i.e. the one guiding the lecture notes browsing) is the only one to have the right to speak to the class attendees. General Integration Approach As previously mentioned, and illustrated in Fig. 1, LEICA follows a hybrid architecture where Web ServicesWS are applied at the collaborative sessions start up, and an event notification system allows collaborative applications to interact through the exchange of event notifications. Two other basic components of LEICA are the Wrappers and the Session Configuration Service (SCS). The integration of a collaborative application to LEICA is achieved by attaching a Wrapper to it. Three main cases may be considered: a) open source applications, b) API-based applications, and c) applications without any available API. Integration of open source applications can achieve the tightest interaction degree, since any internal event/action can be exported/performed; it might however imply great development efforts. API-based integration is straightforward, and interaction is limited to the provided API. Applications without API are the most limitating ones, constraining to interact only through application start and stop actions. LEICAs integration approach is mainly driven by case (b), believing that developers are certainly interested in creating specific and performable collaboration tools that can be used either stand-alone or integrated with other applications (through a flexible API, being able to get a great share of the market). This is for instance the case of Skypeâ„ ¢, a successful example of communication tool that has released its API since some time ago. Fig. 2 summarizes LEICAs general integration framework. The first step of the LEICAs integration framework is the Collaborative Application Integration. For instance, in the illustrative scenario presented in III.A, the first step to integrate the CVE with the instant messenger (supporting the chat room associated to the entrance hall), the collaborative Web browser and the audio conference applications, it is necessary to create a Wrapper for each one of these applications. As detailed in Section V, these wrappers can be automatically generated by LEICAs API Factory, based on the API description of each collaborative application. The Wrappers comprise a Web services Services WS interface allowing the collaborative application to register itself with LEICA. As illustrated by Fig. 1, through the Wrappers Web servicesWS ports, the integrated application can interact with the Session Configuration Service (SCS). The SCS is a Web service Service WS used for (i) configuring new global SuperSessions and (ii) starting up SuperSessions. A SuperSession is an integrated collaborative session holding the whole collaboration activity. Within the context of a global SuperSession, different specificSessions can exist. A specificSession is a conventional collaborative session defined within the context of a collaborative application (e.g. a videoconference session, a whiteboard session, etc.). The SCS dynamically contacts each integrated application, during the SuperSession configuration process, in order to request: (i) which specific data is required to create specificSessions for this respective application (e.g. a videoconference tool could require an IP multicast address); and (ii) which kind of events it can notify, and action requests it can handle. The interaction degree among the integrated applications depends essentially on the nature of the events they are able to exchange, and actions they are able to perform. In order to create a SuperSession, a user must define its integration semantics. It is accomplished by configuring the Collaboration Policy. A Collaboration Policy is a set of rules under a condition/action model. These rules define how collaborative applications must react when receiving information (events) notified by other integrated applications. In other words, the specification of Collaboration Policies allows defining specific integration semantics (i.e. how to coordinate integrated applications) to each SuperSession, according to the different users requirements. Once a SuperSessions has been created (and its associated configuration file is generated), it can finally be started up. The SCS firstly contacts each integrated collaborative application requesting them to create the specificSessions defined in the SuperSession. Then, during the execution of collaborative sessions the integrated application can interact through the exchange of event using the Event Notification System. According to predefined Collaboration Policies, these notifications may lead specific actions to be performed. Wrappers are in charge of managing the SuperSessions Collaboration Policy. When the Wrapper of a collaborative application receives event notifications, it verifies if the notified events enable any policy rule concerning this collaborative application. If so, the Wrapper sends action requests to the respective application. Note that LEICA is not intended to support low-level physical events (e.g. mouse click/scrolling) or high frequency synchronization events (e.g. current position of moving objects). It aims at supporting activity relevant events that carry some semantics. SuperSession Concept As previously mentioned, LEICA controls the whole collaboration activity within the context of a global SuperSession. A SuperSession model has been defined in order to precisely identify and describe its components. Based on this model, LEICA maintains concise and coherent SuperSession state information. Furthermore, a well-defined taxonomy of the components and their attributes are also implied from the model. General models for describing collaborative applications have already been proposed in the literature. Some of them [26][27] [32][33] represent a conceptual or ontological model describing the entities and relationships of individual CSCW systems. Few models aim at describing integrated CSCW systems, like OOActSM [33][34] and the conceptual model presented in [34][35]. However, these models are based on the notion of a general activity as the central abstraction, which was considered rather abstract for a detailed specification of the SuperSession. Nevertheless, these models have inspired several concepts adopted in the defined SuperSession model. The SuperSession represents a collaboration activity involving different integrated applications, a group of users and general roles associated to these users. Formally, a CIE Session CS is a tuple: SS = (SSid, CA , NA , Rl , U , SSat) where: SSid is a unique identifier; CA = {CAi } | i ÃŽ [1,I]} is a finite set of collaborative applications where CAi = (CAidi, spSi, CAati) a specific collaborative application running a set of specificSessions (sSi). CAati is a list of attributes characterizing the collaborative application. These attributes provide information about the application description, including name, type, whether it is a role-based application, its distribution architecture (client/server, multi-servers, peer-to-peer) and the type of user applications (stand-alone or webWeb-based).); NA is a finite set of non-collaborative applications (data converters, databases, web applications, etc.); Rl = {Rlk } | k ÃŽ [1,K]} is a finite set of general roles. The concept of general role refers to a group of users owning the same set of responsibilities and privileges inside LEICA; Rlk = (Rlidk , Rlatk). Rlidk is a unique role identifier; and Rlatk is a list of attributes characterizing this general role. This list provides details like roles description, membership and administration rights. Regarding the membership, it defines how the role is associated with users: it may be either (i) a static association (there is a membership list), (ii) an automatic association (there is a predicate function based on users parameters and SuperSession state) or (iii) a users choice (password protected or not).); U = {Ul } | l ÃŽ [1,L]} is a finite set of connected users; Ul = (Uidl, URlidl, Mbl, Uatl) represent a user, where Uidl is a unique identifier; URlidl is one general role associated with the user; Mbl is a finite set of membership relations; Uatl is a list of attributes (name, email, IP address, network connection, device type, etc.); Mbl.n = (mCAidl.n , mSidl.n , msRlidl.n) is a membership relation, where mCAidl.n is an application identifier; mSidl.n is a specificSession identifier; msRlidl.n is a finite set of specific roles identifiers. Thus, each membership relation indicates the participation of a connected user to a specificSession of a collaborative application (once connected to the SuperSession, a user can concurrently take part in none, one or more specificSessions of different collaborative applications); SSat is a list of attributes characterizing the SuperSession. These attributes describe information like session context (name, purpose, etc.), scheduling (if scheduled or not, duration, etc.), accessibility type (open or closed), role association type (how users are associated to a general role) and maximum number of connected users. A specificSession regards a conventional collaborative session of a collaborative application. The role of the specificSession entity (spSi.m), wich is formally represented by the tuple: spSi.m = (Sidi.m, sRli.m, pUidi.m, Rsi.m, spSati.m) is not to precisely describe each aspect of a collaborative task. Instead, it captures relevant elements like the specific roles defined for this session (sRli.m), the users participating to this session (pUidi.m.) and the shared resources accessed by these users (Rsi.m). A specific role is a tuple, sRli.m.o = (sRlidi.m.o, sRlati.m.o), where sRlidi.m.o is a specific role identifier and sRlati.m.o is a list of attributes characterizing the specific role (description and maximum number of simultaneous users). A resource is also a tuple Rsi.m.p= (urli.m.p, Rsati.m.p ), where urli.m.p is a resource locator and Rsati.m.p is a list of attributes characterizing the resource. The purpose of the resource element is simply to allow the implementation of an inter-application access control mechanism. LEICA will not need to keep the state of each resource. Thus, resources attributes just describe its type (file, device, virtual object, interface widget, etc.) and the read/write access type (exclusive or concurrent). SuperSession Configuration In order to create a SuperSession, a two step configuration process is carried out: (i) Session Management configuration and (ii) Collaboration Policy configuration. In the first configuration step, two groups of information should be specified: General Session Management information (GSMinfo): It carries management information such as scheduling, membership and general user roles.; Integrated Applications information (IAinfo): It defines the list of integrated applications to be used during this SuperSession; for each collaborative application, a list of specificSessions is defined, where specific data required by this application for creating sessions is provided (e.g. a videoconference application will be provided with an IP multicast address). Once Session Management configuration is completed, the Collaboration Polic Computer Supported Cooperative Work (CSCW) Computer Supported Cooperative Work (CSCW) Abstract- In the Computer Supported Cooperative Work (CSCW) domain, researchers have always wondered about which principles and models to adopt for the development of collaborative applications capable to really meet the needs of their users. However, these users requirements are unpredictable and depend on several task or environment-related factors. Integrated collaborative environments are rarely open, extensible and reconfigurable enough so as to meet these requirements. This paper presents an environment, called LEICA (Loosely-coupled Environment for Integrating Collaborative Applications), allowing the integration of existing cooperative applications. LEICA adopts a loosely-coupled integration approach which is based on Web services Services technology, an event notification system, and the definition of Collaboration Policies to control the interactions among integrated applications. LEICA allows different functionalities of existing applications to be dynamically combined and controlled, enhancing therefore the flexibility. Through a case study we show how LEICA was successfully used to integrate three collaborative applications: a co-browsing tool, an instant messaging tool and a VoIP conference controller. Index Terms-Collaborative work, integrated collaborative environments, web services. INTRODUCTION Advances in networking and computing technologies, combined with the fact that companies and work teams are becoming geographically distributed, have created increased a need for communication technologies to ease distance collaboration among distributed individuals (virtual work teams). This leads to the appearing of the so-called Integrated Collaboration Environments (ICEs), having as main goal to integrate different collaborative applications together into a single easy-to-use operational environment [1]. Users needs are very frequently unpredictable and depending on several emerging factors, including the size of the workgroup, the collaborative activities to be accomplished, the intensiveness of the required communications, the coordination policy and the communication needs of the workgroup. Therefore, the possibility of dynamically integrating new functionalities to the environment appears as an important characteristic for collaborative applications [3]. Supporting the integration of new collaborative functionalities reflects how flexible the environment is while responding to unpredictable users needs. We can define this characteristic as integration flexibility that denotes the ease with which an ICE can be its functionalities in response to the users needs. Nowadays one of the main problems of ICEs is that their lack of integration flexibility and as consequence various users decide to set-up their own environments composing different collaborative applications executed independently. In this case, each application is completely isolated from others, without any possibility of coordination among them. This lack of integration can lead to a loss of control from the part of the user, since the operation environment is particularly artificial. Promoting the integration flexibility of ICEs could bring significant benefits to users, allowing different functionalities of existing applications to be dynamically combined and controlled (enhancing therefore the flexibility itself). For instance, a whiteboard application can be integrated with an instant messaging application in such a way that whenever a user joins an instant messaging room, he is automatically logged into the same whiteboard session, instead of been forced to manually login into a session of each one of these collaborative tools. Another case could be the integration of a distributed game and an audio conference application. Whenever a user avatar enters a level/place into the game, his is logged into the audio conference session associated to that level/place, so that the users can online discuss with each other. In order to achieve the integration of existing collaborative applications without having to deal with their low-level features, this work presents LEICA, a Loosely-coupled Environment for Integrating Collaborative Applications. Relying on Web services Services (WS) technologies and an event notification system, different collaborative applications can interoperate by exchanging information within the context of a global collaborative session. The loosely-coupled approach proposed by LEICA overcomes a key problem usually related to integration environments it does not require a true semantic integration of applications. Accordingly, it supports further integration possibilities, such as the integration of third party applications, enhancing, thus, flexibility. LEICA also offers flexibility in the level of the integration semantics. Based on Collaboration Policies to control the interactions between integrated applications, LEICA provides means to define how the collaboration activity supported by one collaborative application will be affected by information received from other collaborative applications. In practice, these collaborative applications interact through the notification of events which may lead to performing specific action(s) in some of these applications themselves. As we will explain later in detail, we think that once a collaborative session has been configured, the use of LEICA can improve users productivity by reducing the application-related administrative tasks, focusing precisely on the collaboration activity itself, and all that by just by interpreting the rules stated for a particular session, all this in function of some pre-established policy rules (also to be explained in detail later). In this way users will find a more natural collaboration environment from the users point of view. In order to illustrate the usability of LEICA in real-world conditions, this paper presents a case study that demonstrates the capability of LEICA to integrate collaborative applications. In this case study, LEICA was successfully used to integrate three collaborative applications: a co-browsing tool, instant messaging tool and a VoIP conference controller. The paper is structured as follows. Section II presents related work regarding the integration of CSCW systems. Section III overviews the general integration approach proposed by LEICA. Section IV explains how to specify Collaboration Policies. Section V presents the LEICAs architecture, detailing how to integrate applications in practice. Some implementation issues are considered in section VI. Section VII describes a case study illustrating the use of LEICA. Finally, in section VIII we draw some conclusions and presents directions of future work. RELATED WORK There are several works oriented to improving integration flexibility of collaborative environments. In this context, four main approaches can be identified: user-tailorable solutions; CSCW toolkits; middleware based solutions; and platforms for integration of heterogeneous collaborative systems. User-Tailorable Solutions As stated in [2], different definitions of tailorability can be found in the literature. Most of them focus on user tailorability ([3], [4], [5] [6]) defining that a tailorable application can be adapted and modified by its own users in order to meet their different requirements. In CSCW, tailorability must focus on the requirements of the group task and of the organization, in which the CSCW system is used [5]. Actually, tailorability is one of the main concerns of groupware development methods. For example, application of participatory design methods ([7] [8]) has been proposed in order to approach the user involvement during groupware development, augmenting thus the opportunities for tailoring. According to [6], tailoring can be supported in three different levels: customization, selecting among a set of predefined configuration options; integration, linking together predefined components within or between applications; extension, improving the implementation by adding new program code. Most of user-tailorable groupware tools support only the customization or integration level (e.g. [2] [9]). Note that the integration level supposes that the functionality to be integrated has been pre-developed and is available somewhere [6]. Only at the extension level users would be able to integrate new functionalities, even if they have not been anticipated by developers at design time. A method frequently used for supporting tailoring at the extension level is the component-based tailoring. For example, in [10], components are implemented using Flexibeans (an extension of the Java Beans model) and end-users tailor the system using a composition language. In [11], end-users may assemble components into larger composite components using the visual representation rather than writing lines of code. However, even at the extension level the integration flexibility is partial as the integration of existing collaborative systems or groupware would require them to be redesigned according to the system architecture. CSCW Toolkits CSCW toolkits ease the implementation of CSCW systems by providing reusable components and behaviors designed to be applicable in a range of circumstances [12]. The need for flexibility and tailorability in CSCW toolkits is well acknowledged. The Neem Platform [13] offers a generic (application-neutral) evolvable framework upon which socially and culturally aware applications are developed. Flexibility and extensibility in Neem result from its foundation on a core architectural coordination model [13]: decoupled components interact indirectly through message exchanges. Intermezzo [14] is a collaboration support environment supporting the coordination information sharing, offering fluid interactions, user awareness, session management and policy control. It addresses dynamic flexibility [12] by allowing applications to adapt not just their own behavior, but also the behavior of the toolkit in reacting to the changing dynamics of the world they run into. The Groupware Toolkit/Shared Dictionary (or GT/SD) toolkit [15][16] has been developed to support rapid development of groupware, focusing mainly on networking and data sharing aspects. GT/SDs extensibility is based on its modular design, which allows adding or modifying behavior by replacing or wrapping different components. Toolkits may represent an interesting solution for helping the development of CSCW systems, as they promote the reuse of components. But in general, CSCW toolkits offer a limited set of functionalities or they are target for some specific kind of domain. Besides, to reuse components of the toolkit, developers often need to implement very specific details of the toolkit in order to adapt it to the application needs [16][17]. Middleware based solutions The integration of heterogeneous applications has been a widely investigated subject, mainly in distributed systems area. General integration solutions based on middleware, like CCM (CORBA Component Model), .NET and Enterprise JavaBeans have been developed. Moreover, integration solutions associated with specific domains have also been proposed, such as Enterprise Application Integration systems [17][18]. The emergence of Web services WS has also led to the development of general solutions for integration of distributed applications, due mainly to the use of open standards. In the CSCW domain, some middleware-based solutions have been proposed. Dustdar et al. [18][19] discuss the importance of using Web services WS in order to provide collaborative application interoperability. But in order to be integrated, collaborative applications must originally support Web servicesWS. Even if Web servicesWS represent an emerging software trend, only a limited set of collaborative applications are currently supporting these technologies. As an enhancement to traditional middleware, some SOA (Service Oriented Architecture) solutions have also been proposed. For example, WGWSOA [19][20] uses Web ServicesWS as an access interface in order to support the reuse and the interoperability of different collaborative services. But an important drawback of WGWSOA is that collaborative services must be developed following the respective middleware architecture. It is also important to note that like WGWSOA, most middleware based solutions present technical responses to the so called syntactic interoperability [20][21]. They provide mechanisms allowing applications to communicate and interact through information exchange. But according to [21][22], the integration concept goes beyond the possibility of sharing and exchanging specific information. Applications must agree upon the meaning (or the semantics) of these exchanges. In other words, integration solutions should provide means for defining integration semantics. Thus, interoperability can be seen as a requirement for integration. The EcoSpace Project [22][23] proposes an environment that, besides being based on SOA and Web servicesWS, relies on Semantic Web technologies (WSDL-S with services ontologies) to support semantic description of collaborative services. Besides a semantic description of each service, it would be necessary a semantic description of the composition of services so as to coordinate their orchestration. However, this part of the project remains as design aspect. Moreover, using Web serviceWSs as integration technology may imply some performance loss, particularly associated to the use of SOAP (Simple Object Access Protocol) [23][24]. Luo et al. [24][25] claim that Web ServicesWS should be only used in situations which are really heterogeneous. They propose a service-oriented solution for the integration of collaborative applications that, instead of using SOAP, adopts a unified service bus (implemented through an open source Enterprise Service Bus). Platforms for integrating heterogeneous collaborative systems The latter latest approach to improve the integration flexibility of collaborative environments is to create platforms aiming specifically at the integration of collaborative applications. They focus on the integration of collaborative functionalities provided by these applications while trying to define any semantics behind integration. Iqbal et al. [25][26] propose an integrative framework based on the three-level model presented by [26][27]: the Ontological Model specifies shared objects, their relations and taxonomies; the Coordination Model specifies how interactions take place during system execution; and the User Interface Model specifies how the system is presented to the final user. Integration process consists firstly in identifying, for each collaborative application, the elements associated with these three models. Then, on each level the elements from different applications are grouped and merged when equivalent. As a result, common ontological, coordination and user interface models are generated. In spite of enabling a multi-level integration, this approach requires an internal knowledge of the collaborative applications so that their functionalities can be mapped into the three-level model. Accordingly, the integration of third party applications becomes a complex task. In order to avoid considering application internals during the integration process (facilitating the integration of existing applications), some integration solutions propose the so called loosely-coupled approach. This approach presents two main features: (i) once integrated to the environment, collaborative applications preserve their autonomy, i.e., they can still be used as standalone application; (ii) the integration environment remains independent of integrated applications, and accordingly, applications can be integrated and detached from the environment without compromising its behavior. This last feature is particularly important considering the integration flexibility aspect. In fact, in a loosely-coupled environment, the set of integrated applications must be easily modified according to users needs. Systems like AREA [27][28] and NESSIE [28][29] have proposed a loosely-coupled integration for supporting cross-application awareness. Both systems represent a collaborative environment where independent applications can share a common information space, implemented through an event notification system. Users can receive notifications of activity relevant events from different applications (executed by other users). An important aspect of these systems is the use of open Internet technologies (such as HTTP and CGI) to enable the integration of third party collaborative applications. However, the main drawback of both systems is that the integration semantics is statically defined collaborative applications are integrated so as to offer a common awareness of the whole collaboration activity. Another proposal also based on a loosely-coupled approach is the framework XGSP [29][30]. XGSP proposes the integration of audio and videoconferencing tools based on SIP and H.323 standards, as well as the integration of Access Grid applications [30][31]. In this framework, XGSP manager servers are in charge of controlling collaborative sessions. A different gateway is defined for each application type (i.e. SIP, H.323 and Access Grid applications). Using a signaling protocol based on Web servicesWS, these gateways are employed to mediate the communication between applications and XGSP servers. An important disadvantage of XGSP is the fact that, originally, it only allows the integration of application based on SIP, H.323 and Access Grid. Loosely-coupling is also inherent to the Web servicesWS based solutions presented in the previous section. Similarly to those solutions, LEICA represents an integration environment that proposes a loosely-coupled approach based on Web servicesWS technologies. Regarding the performance implications of SOAP, Alonso et al. [31][32] suggest that Web ServicesWS technologies should be used only to implement coarse-gained interactions, where the impact of the overhead associated to SOAP would be less important. Following the recommendations of [31][32], Web servicesWS are employed by LEICA for coarse-grained operations only. As it will be detailed in the following sections, LEICA defines a hybrid architecture where Web ServicesWS are applied as an initial mechanism for registering newly integrated applications, as well as for setting and starting up collaborative sessions. Then, during the execution of integrated collaborative sessions a different infrastructure is used to interconnect collaborative applications. Another important aspect concerns integration semantics. Unlike the previous solutions, LEICA provides users with the possibility to define the desired integration semantics for each collaborative session. The Integration Environment: LEICA LEICA aims at the integration of different collaborative applications, where integration semantics is to be defined according to user requirements. Before explaining the general integration approach and the behavior of LEICA, a possible scenario is presented to better illustrate the advantages of such integration. Integration Scenario An important domain where collaborative environments have been largely used is e-Learning. In particular, a CVE (Collaborative Virtual Environment) can be used to implement a 3D shared world representing a school building divided into: one entrance hall, classrooms, and teachers rooms. Different collaborative applications could be associated to each room: (i) a chat room associated to the entrance hall; (ii) a collaborative web browsing (it would enable teachers to guide students through lecture notes) and an audio conference tool associated to the classrooms; and (iii) a shared whiteboard associated to each of the teachers room. Un paragraphe pour montrer la situation: Utilisation des outils non integrà ©es, et lintà ©gration avec LEICA. With this integration semantics, whenever an avatar enters into a room, the respective user is automatically connected to the associated collaborative application(s). Besides, only authorized users should enter into private rooms (e.g. the teachers rooms with its whiteboard could be restricted to teachers). Another possible behavior specified by this integration semantics is some kind of floor coupling between the two applications used as a support for virtual class sessions. This way, it would be possible to assure that the user holding the Web browsing floor (i.e. the one guiding the lecture notes browsing) is the only one to have the right to speak to the class attendees. General Integration Approach As previously mentioned, and illustrated in Fig. 1, LEICA follows a hybrid architecture where Web ServicesWS are applied at the collaborative sessions start up, and an event notification system allows collaborative applications to interact through the exchange of event notifications. Two other basic components of LEICA are the Wrappers and the Session Configuration Service (SCS). The integration of a collaborative application to LEICA is achieved by attaching a Wrapper to it. Three main cases may be considered: a) open source applications, b) API-based applications, and c) applications without any available API. Integration of open source applications can achieve the tightest interaction degree, since any internal event/action can be exported/performed; it might however imply great development efforts. API-based integration is straightforward, and interaction is limited to the provided API. Applications without API are the most limitating ones, constraining to interact only through application start and stop actions. LEICAs integration approach is mainly driven by case (b), believing that developers are certainly interested in creating specific and performable collaboration tools that can be used either stand-alone or integrated with other applications (through a flexible API, being able to get a great share of the market). This is for instance the case of Skypeâ„ ¢, a successful example of communication tool that has released its API since some time ago. Fig. 2 summarizes LEICAs general integration framework. The first step of the LEICAs integration framework is the Collaborative Application Integration. For instance, in the illustrative scenario presented in III.A, the first step to integrate the CVE with the instant messenger (supporting the chat room associated to the entrance hall), the collaborative Web browser and the audio conference applications, it is necessary to create a Wrapper for each one of these applications. As detailed in Section V, these wrappers can be automatically generated by LEICAs API Factory, based on the API description of each collaborative application. The Wrappers comprise a Web services Services WS interface allowing the collaborative application to register itself with LEICA. As illustrated by Fig. 1, through the Wrappers Web servicesWS ports, the integrated application can interact with the Session Configuration Service (SCS). The SCS is a Web service Service WS used for (i) configuring new global SuperSessions and (ii) starting up SuperSessions. A SuperSession is an integrated collaborative session holding the whole collaboration activity. Within the context of a global SuperSession, different specificSessions can exist. A specificSession is a conventional collaborative session defined within the context of a collaborative application (e.g. a videoconference session, a whiteboard session, etc.). The SCS dynamically contacts each integrated application, during the SuperSession configuration process, in order to request: (i) which specific data is required to create specificSessions for this respective application (e.g. a videoconference tool could require an IP multicast address); and (ii) which kind of events it can notify, and action requests it can handle. The interaction degree among the integrated applications depends essentially on the nature of the events they are able to exchange, and actions they are able to perform. In order to create a SuperSession, a user must define its integration semantics. It is accomplished by configuring the Collaboration Policy. A Collaboration Policy is a set of rules under a condition/action model. These rules define how collaborative applications must react when receiving information (events) notified by other integrated applications. In other words, the specification of Collaboration Policies allows defining specific integration semantics (i.e. how to coordinate integrated applications) to each SuperSession, according to the different users requirements. Once a SuperSessions has been created (and its associated configuration file is generated), it can finally be started up. The SCS firstly contacts each integrated collaborative application requesting them to create the specificSessions defined in the SuperSession. Then, during the execution of collaborative sessions the integrated application can interact through the exchange of event using the Event Notification System. According to predefined Collaboration Policies, these notifications may lead specific actions to be performed. Wrappers are in charge of managing the SuperSessions Collaboration Policy. When the Wrapper of a collaborative application receives event notifications, it verifies if the notified events enable any policy rule concerning this collaborative application. If so, the Wrapper sends action requests to the respective application. Note that LEICA is not intended to support low-level physical events (e.g. mouse click/scrolling) or high frequency synchronization events (e.g. current position of moving objects). It aims at supporting activity relevant events that carry some semantics. SuperSession Concept As previously mentioned, LEICA controls the whole collaboration activity within the context of a global SuperSession. A SuperSession model has been defined in order to precisely identify and describe its components. Based on this model, LEICA maintains concise and coherent SuperSession state information. Furthermore, a well-defined taxonomy of the components and their attributes are also implied from the model. General models for describing collaborative applications have already been proposed in the literature. Some of them [26][27] [32][33] represent a conceptual or ontological model describing the entities and relationships of individual CSCW systems. Few models aim at describing integrated CSCW systems, like OOActSM [33][34] and the conceptual model presented in [34][35]. However, these models are based on the notion of a general activity as the central abstraction, which was considered rather abstract for a detailed specification of the SuperSession. Nevertheless, these models have inspired several concepts adopted in the defined SuperSession model. The SuperSession represents a collaboration activity involving different integrated applications, a group of users and general roles associated to these users. Formally, a CIE Session CS is a tuple: SS = (SSid, CA , NA , Rl , U , SSat) where: SSid is a unique identifier; CA = {CAi } | i ÃŽ [1,I]} is a finite set of collaborative applications where CAi = (CAidi, spSi, CAati) a specific collaborative application running a set of specificSessions (sSi). CAati is a list of attributes characterizing the collaborative application. These attributes provide information about the application description, including name, type, whether it is a role-based application, its distribution architecture (client/server, multi-servers, peer-to-peer) and the type of user applications (stand-alone or webWeb-based).); NA is a finite set of non-collaborative applications (data converters, databases, web applications, etc.); Rl = {Rlk } | k ÃŽ [1,K]} is a finite set of general roles. The concept of general role refers to a group of users owning the same set of responsibilities and privileges inside LEICA; Rlk = (Rlidk , Rlatk). Rlidk is a unique role identifier; and Rlatk is a list of attributes characterizing this general role. This list provides details like roles description, membership and administration rights. Regarding the membership, it defines how the role is associated with users: it may be either (i) a static association (there is a membership list), (ii) an automatic association (there is a predicate function based on users parameters and SuperSession state) or (iii) a users choice (password protected or not).); U = {Ul } | l ÃŽ [1,L]} is a finite set of connected users; Ul = (Uidl, URlidl, Mbl, Uatl) represent a user, where Uidl is a unique identifier; URlidl is one general role associated with the user; Mbl is a finite set of membership relations; Uatl is a list of attributes (name, email, IP address, network connection, device type, etc.); Mbl.n = (mCAidl.n , mSidl.n , msRlidl.n) is a membership relation, where mCAidl.n is an application identifier; mSidl.n is a specificSession identifier; msRlidl.n is a finite set of specific roles identifiers. Thus, each membership relation indicates the participation of a connected user to a specificSession of a collaborative application (once connected to the SuperSession, a user can concurrently take part in none, one or more specificSessions of different collaborative applications); SSat is a list of attributes characterizing the SuperSession. These attributes describe information like session context (name, purpose, etc.), scheduling (if scheduled or not, duration, etc.), accessibility type (open or closed), role association type (how users are associated to a general role) and maximum number of connected users. A specificSession regards a conventional collaborative session of a collaborative application. The role of the specificSession entity (spSi.m), wich is formally represented by the tuple: spSi.m = (Sidi.m, sRli.m, pUidi.m, Rsi.m, spSati.m) is not to precisely describe each aspect of a collaborative task. Instead, it captures relevant elements like the specific roles defined for this session (sRli.m), the users participating to this session (pUidi.m.) and the shared resources accessed by these users (Rsi.m). A specific role is a tuple, sRli.m.o = (sRlidi.m.o, sRlati.m.o), where sRlidi.m.o is a specific role identifier and sRlati.m.o is a list of attributes characterizing the specific role (description and maximum number of simultaneous users). A resource is also a tuple Rsi.m.p= (urli.m.p, Rsati.m.p ), where urli.m.p is a resource locator and Rsati.m.p is a list of attributes characterizing the resource. The purpose of the resource element is simply to allow the implementation of an inter-application access control mechanism. LEICA will not need to keep the state of each resource. Thus, resources attributes just describe its type (file, device, virtual object, interface widget, etc.) and the read/write access type (exclusive or concurrent). SuperSession Configuration In order to create a SuperSession, a two step configuration process is carried out: (i) Session Management configuration and (ii) Collaboration Policy configuration. In the first configuration step, two groups of information should be specified: General Session Management information (GSMinfo): It carries management information such as scheduling, membership and general user roles.; Integrated Applications information (IAinfo): It defines the list of integrated applications to be used during this SuperSession; for each collaborative application, a list of specificSessions is defined, where specific data required by this application for creating sessions is provided (e.g. a videoconference application will be provided with an IP multicast address). Once Session Management configuration is completed, the Collaboration Polic