Introduction to Astronomy Essay Example for Free

Introduction to Astronomy Essay The life cycle of a star is a process that is not only beautiful but, fascinating to those fortunate ones who have the chance to study the subject. To the uneducated soul, gazing upon the night sky wondering what is out there is not a common thing. But being able to learn about what is really out there and how it became, that my friends, is truly an amazing task. One has to wonder just how we know what type of star we are looking at or at what point in the star’s life cycle the star dwells. Since the dawn of man, we have studied the stars, and until the last century, astronomers have found ways to measure four properties of stars: their luminosities, temperatures, radii, and masses. With this knowledge, they now have classified thousands of stars by plotting these stars on diagrams and charts characterized by any pair of these specific properties. A Star is Born Stellar Nursery – Nebula The proverbial birth of a star starts within a huge cloud of gas and dust known as a nebula. A nebula is approximately 21 light-years in width. When the gases and elements of the nebula start to contract due to the pull of its own gravity, it will create a protostar, which can startingly grow to roughly 60 million miles across. This is where the star begins to take shape. In order for a star to grow, it will need nuclear fusion to take place, and that requires tremendous amounts of pressure and heat. Main Sequence Stars The enormous pressure that is created compresses together elements to form more elements and to create energy. With hydrogen being the least dense and easiest to fuse, stars begin fusing hydrogen first. The side effect of this fusing of nuclei, or nuclear fusion, is the production of two positrons, two neutrinos, and the release of energy. Stars that are in the hydrogen burning process are known to be in the main sequence. Stars will spend the majority of their lifespan in the main sequence. Using the standardized classification system, astronomers find that about 90% of all stars cluster in thin bands on each the noted diagrams. Red Giant Eventually in the star’s life, the hydrogen supply in the core will begin to expire, when this happens, the sun’s core becomes unstable and will begin to contract. Consequently, the outer shell of the star, which consists mainly of hydrogen, will start to expand. During the expansion, it cools and will begin to glow red. The star now resides a red giant phase of its life cycle (Cain, 2009). Practically all stars will evolve identically up to the red giant phase, yet depending on the amount of mass a star, the next phase in the life cycle can be greatly different. Supergiants One possible evolution of extremely massive stars, although rare, is to become a supergiant. But what is a supergiant? When the radiation released by the fusion of helium into carbon it causes the red giant to expand even larger, perhaps into a star roughly 400 times the Sun’s size. The End of Days – Death of a Star White Dwarf A white dwarf, or a remnant of a star that has collapsed, are the destiny of stars like our sun. This phase in the life cycle is attained when the nuclear fuel supply is exhausted. Typically, a white dwarf can have the mass of about six-tenths the mass of our sun, but obtains size considerably smaller than that of the Earth. A white dwarf is formed when the shroud of a red giant is ejected as the core burns the last bits and pieces of its nuclear fuel. A white dwarf slowly fades into oblivion as it cools down. Supernova Possibly, exceedingly massive stars can continue to fuse heavy elements in order to produce more energy. Nevertheless, once iron is formed, it cannot be fused to make more energy. This is because iron has such a high binding energy and is thus very stable. Due to the immense gravity, the core will collapse and huge amounts of gas on the surface will blast out into space. This phase in the star’s life cycle has now become a supernova. Neutron Star Following a supernova explosion, the iron core of the star may be enormously massive, and may have an immense force of gravity. It has now become a neutron star, where the negative force, or pushing effect, between neutrons stops the contraction caused by gravity. Pulsar It is possible for a neutron star to spin rapidly following a supernova explosion. A result of this spinning, the neutron star may send out two beams of radio waves, light, and X-rays. These beams radiate in a circle as the star is spinning, and thus appears that the light from the star is pulsing intermittently. This is why it is called a Pulsar. Blackhole Yet some extremely massive supergiants, many with a mass more than four times that of our own Sun, may continue contracting until their nuclei are compacted into even more dense matter. The compacting matter forms a body so dense that it forms a black hole. A black hole is an extremely massive and dense, spectral body with a gravitational pull powerful enough to prevent the escape of light (Newman, 2002). Life as We Know It Astronomers believe Earth and all its living organisms are composed of elements formed in the interiors of stars, especially supergiants that exploded as supernovas. As astronomers across the globe scour planetary systems, both within and beyond our galaxy, in the quest to find life, they are centering their attention on each systems habitable zone. The habitable zone is where heat radiated from the star is just right to keep a planets water in liquid form (Williams Pollard, 2000), the sweet spot of the solar system.

Laser beam welding

Laser beam welding Introduction: Laser Beam Welding â€Å"LBW† is a contemporary welding process that is a high energy beam that continues to expand into new industries and new applications because of its advantages like deep welding and reduced heat inputs. Profound Manufacturers sought to automate the welding process caused the expansion of the laser beam welding process to include computers and more sophisticated technology to increase the product quality and more accurate control of the welding process. From More than 20 years ago, when laser welding was in its early life was used primarily for bizarre applications where no other welding process would be suitable. Nowadays, laser welding is an imperative part of the metal toil industry. How It Works: The Focal point is aimed on the work piece surface that will be welded. At the surface the large concentration of light energy is converted into thermal energy. The surface of the work piece starts melting and steps forward through it by surface conductance. For welding process, the beam energy is maintained below the vaporization temperature of the material. In Fig. 1 the laser beam is directed on the work piece. â€Å"To the point that the laser beam contacts the work piece, all the components that direct it are transparent, refractive or reflective, absorbing only small amounts of energy from the ultraviolet light.† The laser power supply is capable of delivering a pulse of light that has accurate and repeatable energy and duration. When the pulse of laser energy is focused into a small spot at the surface of the work piece, the energy density becomes enormous. The light is engrossed by the work piece, causing a keyhole effect as the focused beam drills into, vaporizes and melts some of the metal. As described in fig. 2. As the pulse ends, the liquefied metal around the keyhole flows back in, solidifying and creating a small spot weld, moving the work piece or the laser emitter along the surface of the work piece creates a series or spot weld that is called a â€Å"seam†. Similarities And Differences To Other Welding Processes When compared to other welding processes, laser welding has some similar as well as some unique characteristics Like GTAW (Gas Tungsten Arc Welding), laser welding is a fusion process performed under inert cover gas, where filler material is most times not added. Like electron beam welding, Laser welding is a high energy density beam process, where energy is targeted directly on the workpiece. Laser differs from both GTAW and EB (electron beam) welding in that it does not require that the workpiece complete an electrical circuit. And since electron beam welding must be performed inside a vacuum chamber, laser welding can almost always offer a cost advantage over EB in both tooling and production pricing. Advantages Of Laser Welding One of the largest advantages that pulsed laser welding offers is the minimal amount of heat that is added during processing. The repeated pulsing of the beam allows for cooling between each spot weld, resulting in a very small heat affected zone. This makes laser welding ideal for thin sections or products that require welding near electronics or glass-to-metal seals. Low heat input, combined with an optical (not electrical) process, also means greater flexibility in tooling design and materials. Industries Served: 1- Aerospace. 2- Defense/military. 3- Electronics. 4- Research development. 5- Medical. 6- Sensors instrumentation. 7- Petrochemical refining. 8- Communications energy. Laser Safety â€Å"Lasers emit a very concentrated beam that can be visible or invisible. In general, most lasers used for welding are invisible. This beam of infrared light could focus onto the skin or eye unless safety precautions are observed. Industrial laser systems are fully interlocked to prevent any danger to operators. Most are equipped with National Center for Devices and Radiological Health covers that contain the actual laser operation, permitting people working nearby to perform normally.† With proper design and careful precautions, laser systems are no more dangerous than other welding systems or similar machine tools.

Insulin and Erythropoietin Production

Insulin and Erythropoietin Production Insulin is a protein (polypeptide) discovered in 1921 by Banting with the pancreas being the site of its production. It is made up of 51 amino acids, divided into 2 chains; A and B, bonded by disulfide linkages. Chain A is made up of 21 amino acids with an intra-disulphide linkage, while chain B is made up of 30 amino acids (4). Why Insulin? Insulin is important in glucose metabolism, and is being used for the treatment of Diabetes mellitus; a metabolic disorder of glucose in the body. Initially, Insulin from animals was used to treat this disorder however nowadays synthesized human Insulin is being used, this is because; it is fast absorbed by the body, it has less allergic reactions, it contains less impurities, and it produces good results (3). Recombinant process of producing Insulin Synthetic Insulin was first produced in 1983 through genetic Engineering, which involve extraction of the human DNA (1), once extracted, the gene for Insulin is isolated, and enzymes are used to cut it. The gene is then cut using enzymes and put into the plasmid of a vector, where in most cases E. coli plasmid is used. Since Insulin contains two chains, two pieces of DNA are extracted, and the genes for the two chains are linked to ÃŽ ² galactosidase enzyme of the bacteria. The plasmids formed are then inserted into a host cell E. coli and sealed using another enzyme called ligase. And the host on replicating produces the enzymes each containing one of the two chains each. Production is followed by extracting and purifying the chains which are mixed in a reaction to reconstitute the disulphide bridges (1). ESCHERICHIA COLI AS RECOMBINANT INSULIN HOST Entero-bacillus, gram-negative E. coli is about 1 2ÃŽ ¼m, it can survive in the presence/absence of oxygen, and it also grows in an optimum pH and temperature of 7.0 and 37oC respectively. It utilizes glucose as its major carbon source and can also use other carbon sources like pyruvate, glycerol, acetate, and other sugars. K-12 and B strains are mostly used in the laboratory (20) Reasons for choosing E. coli Genetic Engineering technologies were developed using E. coli as a role organism, and so, the genetics of E. coli are well known among other microorganisms, as such its the most used organism for the production of different proteins (14). Moreover E. coli has a well known safety and production abilities, stable plasmid, controllable promoter, cheaper and easily cultured (6), E. coli also has fast growth rate, its easy to handle, and has well known fermentation skills and the ability to produce high protein content (14). That is why most of the proteins licensed recently by FDA and EMEA, were produced in E. coli (5). With these, and the fact that Insulin is a simple polypeptide (protein) which does not require glycosylation for its bioactivity and stability, E. coli carrying the plasmids for production of insulin will be used as the host for the production of Insulin Strain and plasmids: BL21 strain containing the pMYW-A and pMYW-B plasmids and temperature repressor ÃŽ »-c1857, will be used for insulin production (21). Growth strategy The various growth strategies that will be used to grow E. coli in order to make it happy and produce the desired product (11) include: Medium: E. coli needs nutrients like carbon, nitrogen and others; thus a carbon source; glycerol will be provided since its cheaper and more soluble than glucose (12), a source of nitrogen in the form of ammonium sulphate will also be provided. However such nutrients in large quantities can inhibit the growth of E. coli, as such a defined medium that contain optimum concentrations 20gl-1 glycerol and 2gl-1 ammonium sulphate will be used (11). The medium will also consist of the following; 3gl-1 KH2PO4, 1gl-1 MgSO4.7H2O, 0.8gl-1 citrate, and 6gl-1 K2HPO4 (23). Some trace elements will also be added to the medium. (23) Process and culture-strategies: E. coli will be grown submerged in a sterile controlled stirred tank reactor, and fed-batch will be used as the growth strategy so as to avoid accumulation of acetate which can be inhibits its growth, and reduce the production of the insulin (18). The growth strategy will be divided into two; initially batch mode will be used to initiate growth, after which the fed-batch exponential feeding will be used to produce the insulin (21). After adapting the medium and feeding method, oxygen transfer rates (OTRs) had to be increased through a suitable bioreactor design and over-head pressure (16). Large scale reactors usually reach high ORTs using air and normal aeration pressure, and so the oxygen partial pressure (pO2) will be increased by adding pure oxygen to the air-stream entering the reactor, thus increasing its oxygen transfer rates (16) DO will be maintained at 40% of air saturation and aeration rate at 1vvm. Foaming arising due to large number of cells and high aeration-rates will be solved by use of impellers for stirring simultaneously at 300rpm and the use of antifoam (ucolub N115) (16, 21). The process temperature and pH will be maintained at 30oC and 6.8 respectively so as to avoid partial proteolysis of the insulin protein. Bioreactor Design: Bioreactor vessel is usually cylindrical and made up of stainless steel. It is composed of impeller for stirring, Air sparger is placed at the bottom of the vessel for introduction of air, it has some inlets for introduction of acid/alkali for pH control and also for introduction of antifoams, nutrients and inoculum; It is also has pH, DO and temperature probes for sensing (22), Microbial activity during fermentation usually produces heat, so the bioreactor design must allow for removal of heat, and this can be achieved by cooling with jackets and coils (16) Bioreactors must also be designed in a way that it can withstand high temperature and pressure and to allow cleaning-up and sterilizing (22). Growth analysis Temperature, pH, DO, foam, partial oxygen and carbon dioxide pressures, will be analysed on-line, other parameters like biomass, will be analysed by using optical density (OD600) and dry cell weight (offline). Cell viability will be analysed by using flow cytometry, the concentrations of substrates and metabolites by enzymatic methods while insulin will be analysed using electrophoresis methods like SDS-PAGE, and ELISA, while its purity will be determined by HPLC (8). Limitations/Problems There are several problems that may arise during processing and can limit the use of this organism for Insulin production, these are; Poor secretion because of the structure of its membrane (and tough cell wall), small amount of foldases, chaperones and increased concentrations of proteases, leading to low productivity (7). Solutions to this problem include all measures taken to increase quality of secretion and production such as: Use of secretion systems like the system of ÃŽ ±-haemolysin (7) co-expression after co-cloning of foldases and chaperones (13) Improving the rates of gene-expression and using proteases deficient mutants like BL21 (18). use of E. coli mutants that are deficient of cell-wall (12) Limited post translational-modifications; including disulfide-linkage formation, which is important for the insulin stability and biological activity (9). Solutions to this problem include; Production of insulin with altered amino acid sequences through genetic engineering (9) Using E. coli mutants to enhance the formation of disulfide linkages e.g. Origami (15) iii. Exporting proteins into the periplasm which has disulphide bonding mechanisms (19). Codon biases; due to large quantities of exact transfer-RNAs found in E. coli, the codons in the human-genes are often different from those that are found in this organism. This results in inefficient expression of some of these rare codons by the organism resulting in an unexpected protein synthesis termination or wrong incorporation of the amino acids (12). This problem can be solved by replacing codons that are rare in the desired gene by codons that are often found in the E. coli and by co-expressing the rare transfer-RNAs (15). Acetate is usually formed as a by-product, and is inhibitory to growth of the cells (20). Solution is by using a fed-batch feeding method and by limiting DO level (11). Another problem is that large proteins are often obtained in an insoluble form (5); forming aggregates called inclusion bodies; IBs (20). This can be solved by adjustment of temperature, increasing the strength of the promoter, adjusting the number of plasmids, concentrations of the inducer, and the composition of the media (9). Erythropoietin EPO EPO is a glycoprotein that is produced in the renal cortex of the kidney (10, 11). It has also being shown to be present in the brain, spleen, liver and the lungs (7, 17). It is made up of 165 amino acids of about 18kDa (25), with a number of carbohydrates linked to the polypeptide through O and N glycosidic-bonds giving the glycoprotein a total weight of 34kDa.Two disulphide linkages hold the molecule together (15) and the carbohydrates are responsible for the stability of the glycoprotein in-vivo,and increasing its half-life in the body (24). Why EPO? EPO functions to regulate the amount of red blood cells (RBC) in the blood by controlling the proliferation and differentiation of its immature cells to mature cells (1, 2, 22,). It is also involved in the growth and formation of blood vessels, and healing of wounds (6), it functions in the brain is not clear, but studies showed the glycoprotein to have some protective effects (18). Because of these functions EPO has being used in the treatment of anaemia caused by kidney failure and other causes (25). Recombinant production of EPO Despite its importance, EPO in body is found in very small amounts and mostly in the urine (4), as such there is the requirement to produce EPO in large amounts, this leads to the work of isolating the glycoprotein from the urine (12, 21), and was used to identify its amino acid sequences, and synthesis of its DNA (9, 12), furthermore the human erythropoietin genes were cloned by Lin et al. (17), and consequently recombinant human EPO (rhuEPO) was produced in 1985 using CHO cells (14, 16). Chinese -Hamster- Ovary (CHO-Cells) as rhuEPO host: These are epithelial cells derived from the ovary of Chinese hamster (a mammal). They grow well in culture and looks like cobble stones. The cells usually attach to a surface available but can be grown in suspension (20). CHO cells are grown best at 37oC and at pH 7.4; they are cultured in a suitable complex medium which can support their growth for many generations (20). CHO cell lines are now available from cell culture collections like the American type culture collection; ATCC. Moreover human EPO expression plasmids are now also commercially available, and are usually used for production of EPO using the CHO cells (27). Reasons for choosing CHO-cells Karthik et al. (13) showed that CHO-cells are being used extensively in the industries for the production of many proteins, because they have demonstrated, to possess some qualities like: They can modify biological products post-translationally; Proteins produce in CHO-cells have high glycosylation quality making them compatible and stable (13) Safety of the product; Studies in 1989 have shown that most viruses do not multiply in CHO-cells (13) Ability to adapt easily and be grown in suspension (13). Products can now be purified to contain less contaminant (13). CHO cells have being used for a long time; as such much data has being accumulated for regulatory reasons (13). They are easy to manipulate genetically (13). The isolation of cells deficient in Dihydrofolate-reductase enzymes leads to stable clones selection and genes amplification to increase production (13). With all these, and the fact that EPO is a glycoprotein that requires glycosylation for its stability and activity, recombinant CHO cells are chosen to produce EPO. Cell lines and plasmids: Cell lines which have the capability of glycosylating proteins (Pro-5), harboring the pGEX-HET-puro expression plasmid, will be used to produce the recombinant human erythropoietin (27). Growth strategy Medium: Complex culture medium will be provided with; Glucose as a source of carbon and energy, Amino acids as source of nitrogen, Salts will be included to make the solution isotonic Vitamins and hormones will be added as co-factors Serum is usually added to the culture medium to enhance the growth of the cell (20), but has the following disadvantages: It chemicals are not defined and can cause cell growth inconsistency between batches (20) It is very expensive (20) The serum may contain proteins which can be difficult to separate and purify from the proteins secreted by the cells during downstream processing (20) It increases foaming and can be a source of contamination by viruses. (20) Therefore a serum-free (SF) media (16) will be used for the growth of the E. coli. Process and culture-strategies: The cells will be grown adherent on micro-carriers in a sterile controlled packed bed reactor, and perfusion method of production where some amounts of the medium is removed and replaced by fresh one and the cells are grown slowly will be used (28); because it was found to improve the glycosylation of the proteins more than fed-batch where there is fast growth of cells, (8). Before, many processes were run in a simple batch method, but nowadays, Perfusion or fed-batch methods are mostly employed and higher products are now realized (22). The production will be carried out in two stages; the growth stage and the production stage. Normally stirring will be kept at 100 to 150 rpm, foaming will be avoided by adding Pluronic F68 (16).Temperature will be maintained at 37oC initially during growth and then reduced to 33oC during production, as was shown to increase the overall protein production, while maintaining the quality of the glycoprotein (3, 26). pH w ill be kept at 7.1 initially and then reduced to 6.8 (8, 26), by passing CO2 gas to the culture or by addition of concentrated sodium-bicarbonate solution in low quantities, because CO2 is also toxic to the cells and can also affect the production of EPO (20). In order to avoid the depletion of oxygen, the oxygen transfer rates (OTRs) will be increased above its utilization rate, with a constant supply of pure oxygen and air, while DO will be maintained at 20-50% of air saturation (20). Bioreactor Design: Since the cells are big and fragile, the design of the bioreactor has to be considered. Mammalian cell culture bioreactors are designed with bottoms that are round and are usually made up of glass/stainless steel (20). The impellers are usually marine or pitched blade types fitted at the end of mechanical drives shafts so that both vertical and horizontal mixing are allowed at low stirring-rates (20). Temperature is controlled through coiled pipes or open ended fermenter jacket (20). pH, DO and temperature probes are used for sensing and have both air inlet and outlet for respiration. Growth Analysis Temperature, pH and DO will be monitored on-line, because cells are immobilized, biomass formed cannot be measured directly therefore it will be monitored by measuring rate of glucose consumed daily and the rate of lactate produced (28) Cell viability by flow cytometry, Glucose, glutamine, and lactate concentrations will be analysed using multi-parameter Bio-analytical system (26); while ammonia formed as waste product of amino acid metabolism, will be analysed by colorimetric assay and by the use of detection-kit (26). EPO formed will be analysed using HPLC to determine its purity and its quality by Isoelectric focusing, SDS, and Bradford assay (26). The activity of EPO will be analysed by bioassay and by the use of protein assay-kit (27) Limitations/Problems. There are many limitations associated with CHO cells culture processes and they include; They are fragile and highly sensitive to shear stress caused by agitation and bubble because the cells are large and have only cell membrane (20). This is usually solved using a suitable bioreactor-design and use of Pluronic F68 (20). They need a complex medium including serum which can cause problems in the downstream processing and is expensive (20). Solution to this is by using serum- free media (24, 25). Low yield of proteins have been produced from these cells, the productivity using the microbes being higher than the use of these cells. They also have slow growth rates (13). The problem of low productivity and slow growth rates can be solved through selecting cell lines that are better and optimizing cultural-strategies. Ammonia and lactate are generated during growth and can inhibit growth and also affect glycosylation (8). Solution is by optimizing the strategies of feeding and by monitoring (8). Glycosylation differences may arise from the EPO produced in the CHO-cells and the human EPO as seen in the way the two are sialylated terminally, as a result that the CHO-cells are not able to express an enzyme called alpha-2,6, sialyltransferase (27). Solution is by the use of CHO-cells harboring alpha-2, 6, sialyltransferase-cDNA expression-cassettes (27). REFERENCES: 1. Alcamo, I., DNA Technology; the Awesome-Skill. Farming-dale. New York: Academic Press. (2001). 2. Banting Grolier Electronic publishing www.littletree.com.au/dna.htm accessed on 30/12/2010 3. Carbs information, www.carb-information.com/insulin-synthetic.htm accessed on 30/12/ 2010. 4. Charce, R.E., and Frank, B.H., Research, Production and Safety of Biosynthetic Human Insulin. (1993). www.littletree.com.au/dna.htm accessed on 30/12/2010. 5. Ferrer-Miralles N. Domingo-Espà ­n, J. Corchero, J.L. Và ¡zquez, E. and Villaverde, A. Microb. fact. for recombinant pharmaceuticals, Microbial factories , 8:17, 2009. 6. Fox, S. Improved processes and new capacity for pipeline to commercial production. Biopharmaceutical contract manufacturing, Volume 1 (report). High Tech Business Decisions: San Jose, CA. 2005 7. Genschev, I., Dietrich, G., Goebel, W.,The E. coli alpha-hemolysin secretion system and its use in vaccine development. Trends Microbiol. 10: 39-45. 2002 8. Hewitt C.J., Nebe-von Caron G., Axelsson B., McFarlane C.M, Nienow A.W Studies related to the scale-up of high-cell-density E. coli fed-batch fermentations using multi-parameter flow cytometry: effect of a changing microenvironment with respect to glucose and dissolved oxygen concentration. Biotech. Bioeng. 70: 381-390. 2000 9. Hite P.F, Barnes A.M.J.P.E. Exhuberance over Exubera. Clinical Diabetes 24: 110-114. 2006. 10. Jana, S., Deb, J.K. Strategies for efficient production of heterologous proteins in Escherichia coli. Appl. Microbiol. Biotech. 67: 289-29. 2005. 11. Joseph S., and Raphael F., growing E. coli to high- cell density-A historical perspective on method development Biotech. Advances 23: 345-357 2005. 12. Korz D.J, Rinas U., Hellmuth K, Sanders E.A, Deckwer W.D. Simple fed-batch technique for high cell density cultivation of E. coli. J Biotechnology, 39: 56-65. 1995. 13. Kujau, M.J., Hoischen, C., Riesenberg, D., Gumpert, J. Expression and secretion of functional mini-antibodies McPC603scFvDhlx in cell-wall-less L-form strains of Proteus mirabilis and E. coli: a comparison of the synthesis capacities of L-form strains with E. coli producer strain. Appl. Microbiol. Biotech. 49: 51-58. 1998. 14. Lund, P.A. Microbial molecular chaperones. Advanc. Microbiol. Physiol. 44: 93-140. 2001 15. Makrides S.C. Strategies for achieving high-level expression of genes in Escherichia coli. Microbiol. Rev. 60: 512-5388. 1996. 16. Meyer, H.P. Brass, J. Jungo, C. Klein, J. Wenger, J. and Mommer, R. an emerging Star for Therapeutic and Catalytic Protein Production. Bioprocess International. 2008. 17. Nacelle, G. J. V. and Coppel, R. L. Reshaping Life; Key Issues in Genetic Engineering, Novo-Nordisk Promotional Brochure. Melbourne: Melbourne University Press. 1989. 18. Schmidt, F.R. Recombinant expression systems in pharmaceutical industry. Appl. Microbiol. Biotech. 65:363-37. 2004. 19. Wacker M., Linton D., Hitchen P.G., Nita-Lazar M., Haslam, S.M., North, S.J., Panico M., Morris H.R., Dell A., Wren, B.W., Aeb, M. N-linked glycosylation in Campylobacter jejuni and its functional transfer into E. coli. Science 298:1790-1793. 2002. 20. Demain, L. A., and Vaishnav, P. Production of recombinant proteins by microbes and higher organisms. Biotech.Advan. 27: 297-306. 2009. 21. Schmidt, M., Raman Babu, K., Khanna, N., Marten, S., Rinas, U., Temperature- induced production of recombinant human insulin in high cell density culture of recombinant Escherichia Coli. Journal of Biotech. 68:71-83. 1999. 22. Ratledge, C. and Kristiansen, B. Basic biotechnology. Cambridge: Cambridge university press. 2001. 23. Tabandeh, F., Shojaosadati, S.A., Zomorodipour, A., Khodabandeh, M., Sanati, M.H., Yakhchali, B. Heat induced production of human growth hormone by high cell density cultivation of recombinant E. coli. Biotech. Letters. 26: 245-250. 2004.

Internet accessibility for people with disabilities :: Essays Papers

Internet accessibility for people with disabilities The Internet has quickly become one of the most beneficial tools in use today. With the click of a button, you can find information on practically anything. In fact, Internet use is so widely used, that it is no longer an eminent skill, but is an ability that is now expected of people. Unfortunately, due to a number of reasons, not everyone can take advantage of this useful tool. With over a half-a-billion disabled people in the world, there should be steps taken to make the Internet more disabled-friendly, which indeed there is. By taking advantage of adaptive technologies, using proper etiquette when sending email, and designing web pages with the disabled in mind, the Internet will soon become useful to more people than would otherwise be the case. One of the major advances in helping the disabled is the use of adaptive technology. Adaptive technology can be described as any hardware or software used to provide alternative methods of input and output. There are two distinct forms of disabled-friendly input devices on a computer, pointing devices and voice recognition. Pointing devices do the same job as a mouse; move the pointer to a certain location on the screen. This equipment comes in different forms, trackballs, oral fixtures, and eye-coordinated input devices are all examples of special pointing devices. The other form of an input device was voice recognition. This form does the job of the keyboard. The user talks into a microphone, and his speech is translated into text by the sound card. Though voice recognition has been around for a couple of years, it is just now getting to the point where a user doesn’t have to pause between words. Companies such as Dragon Systems, IBM, and Lernout & Hauspic, are the leade rs of voice recognition software. However, changing the output of a computer for disabilities is much more common than changing the input. The most common way of changing the output is by screen magnifiers, screen readers, and Braille displays. A screen magnifier is a program that follows the mouse pointer and magnifies that area. This is idea for people with limited or damaged vision. The software used to magnify will do so from about 1.5 to 20 times, depending on which program it is. Products such as MAGic, ZoomText, and InLarge are very popular right now, also Microsoft includes screen magnification in versions of Windows 98 and beyond.

Credebility of Hypnotherapy :: essays research papers

  Ã‚  Ã‚  Ã‚  Ã‚  It is the purpose of this paper to bring attention to the credibility of people in the field of Hypnotherapy (Hypnosis, Self-Hypnosis, and Guided Imagery). By reading through several websites it became apparent that no Ph.D. is necessary to be a Hypnotherapists. All that is required is that you pass and complete 200+ hours of Hypnotherapy training.   Ã‚  Ã‚  Ã‚  Ã‚  Marla A. Sloane at the website www.marlasloane.com is a Member of the American Board of Hypnotherapy and a member of the National Guild of Hypnotists. Sloane is currently working on her Ph.D. She has shown in the past a strong drive in academics by completing high school at age 16, getting a college degree, and starting a corporation. The name of the Corporation however was not stated; nor was the college at which she obtained her degree. She is currently a Registered Hypnotherapist and claims to be able to â€Å"recreate your destiny.† She does have testimonials form people she has treated that support her claim. She sites hypnotherapy being used to help overcome Kevin Costner’s seasickness (which she did not assist in) and states that statistically it is the best way to stop smoking and lose weight. Sloane also sites a random experiment comparing two basketball teams where one was under hypnosis and did better overall.   Ã‚  Ã‚  Ã‚  Ã‚  Chaplain Paul G. Durbin Ph.D. at the website www.durbinhypnosis.com has Professional Affiliations and Awards from numerous organizations. These awards and affiliations can be viewed at www.durbinhypnosis.com/bio.htm. Durbin was in the military, served as Special Assistant to Chief Chaplain, and had a title of Brigadier General. Durbin received his Bachelor of Arts from the College of Louisiana, his Master of Divinity from Emory University in Atlanta GA, his Ph.D. from the American Institute of Hypnotherapy in Irvine CA, and has completed 4 quarters of Clinical Pastoral Education at Walter Reed A.M.C., Washington D.C.. Durbin has been published in hundreds of times in magazines of Religion and Hypnotherapy. Durbin Has also written two books, one of which is out of print, and one of which is in it’s second publishing. Kissing Frogs: Practical Uses of Hypnotherapy published by Kendall/Hunt Publishing Company (educational 1st-college material) and received two awards. The awards were the Pen and Quill Award from NBHA and the Outstanding Performance Award from IMDHA. Durbin did not however have testimonials on his site to back his claims and he uses biblical passages to help promote his business.

propaganda techniques :: essays research papers

Name Calling: giving an idea a bad label, a negative term that sticks. Glittering Generally: opposite of name-calling, uses â€Å"good† words and phrases that have a positive â€Å"glittering† appeal. They are broad, vague, and often meaningless emotionally charged words. Transfer: uses symbols usually, to carry over the authority, sanction and prestige of something respected and revered over to something else in order to make the latter acceptable. Usually patriotism, religion, religion, and associating yourself with someone popular /famous and using that person’s â€Å"coat tails†. In above picture, featuring John Kerry and John Edwards, I see some transfer with the flag behind them. It seems to symbolize that they are still strong and honorable just like the flag. I think they are hoping to seem patriotic to our country despite all the nasty things they said about our president. Testimonial: having some famous, respected person say an idea (or person) is good (or bad). In the photo of Bush and Schwarzenegger, I think Bush is trying to use Arnold’s popularity and fame to get him a few votes not only in California but also around the nation. Plain Folks: Speaker tries to convince his audience that he and his ideas are good because they are of the people, the â€Å"Plain Folks†. Trying to make us think that he/she is just like us. In picture to the right, bush is seen conversating with the troops like one of the boys. Card stacking: involves arranging facts and arguments to be very one-sided. Usually involves leaving out significant information. In the above picture, this person is trying to force these kids into believing they should follow what he says. He is using force and not telling the entire story. Band Wagon: Everybody is following this program, so follow the crowd,† jump on the band wagon†. In picture to the right, it suggests that everyone should smoke marijuana because even the chipmunk is. The Big Lie: if something is repeated enough times, people begin to accept it as truth.

Mens Warehouse

David walks into the Men's Warehouse store. He is getting married. No big fan fare here; no entourage to assist him as his fiance had experienced. David explains his purpose for shopping to Joe, the store sales rep. Joe begin to ask questions as he pull a few looks together that he believes David would like. Joe and David talk and laugh as they find the perfect look David wanted for his big day; Joe was proud – another customer satisfied. David walked out about an hour later knowing he would kook good for his wedding.He felt good George Simmer is known for his classic line, Your goanna like the way you look, I guarantee it†. This is the Men's Warehouse creed. Their emphasis on quality clothes and customer service in their stores has provided them a steady stream of success. However, they don't measure their success by earning growth, geographic expansion or consistent return for investors, although they could have. They measure their success in levels of excellence In cu stomer service, employee enthusiasm and customer loyalty In Dalton to the other uncial measures that are required by successful businesses (Denominator, 2006).The backbone of the Men's Warehouse organizational and financial success falls on their desire to uphold a culture that is based on customer loyalty and employee satisfaction. The purpose of this paper is to identify and discuss the cultural metaphor that the Men's Warehouse has embraced. An organization's culture Like any other culture can be defined by the pattern of development reflected in an organizations system of knowledge, Ideology, values. Laws and day-to-day rituals (Morgan, 2006). However it is more than Just a list of rules required as well. It's a symbolic significance commonality that is shared amongst a group.Culture is not something that can be measured but it is a formed of lived experience created by all within it. Creating a positive organization culture takes work from the top down as Men's Warehouse has su ccessfully demonstrated. Organizations such as the Men's Warehouse benefit from operating from a Cultural Metaphor for many reasons. The cultural metaphor directs attention to the symbolic significance of almost every aspect of organizational life (Morgan, 2006). The activities have more meaning for the employees. For example, suiting someone for their wedding is not a normal shopping trip.It is exciting and stressful. Customers will want to get advice from a tuxedo expert who can help them look their absolute best. Also, if fashion is your passion as an employee you are excited to assist In such a wonderful occasion and Knowingly accept ten responsibility Tort ten customers experience as well. It also holds individuals accountable because it makes them own their impact on the way things are and shows that it is their responsibility to change when appropriate (Morgan, 2006). This is demonstrated at the Men's Warehouse from their top down approach to satisfying customers.Simmer state d in his company overview that â€Å"we are not content to merely satisfy them. We win them over completely. This is not so much the results of rigorous training as it is the result of the unique Mess Warehouse culture that runs from the top down through all our operation†. (Denominator, 2006). Having the authority to do what is necessary to make sure a customer leaves happy allows employees to feel empowered. It is not mistake that in 2006, Men's Warehouse was ranked in Fortune's Magazine list as one of the â€Å"100 Best Companies to Work For† (Denominator, 2006).This was based on the policies and culture of the company and satisfaction and opinions of the employees. The Men's Warehouse prides itself on its culture of collegiality, and repeatable consistent customer service, and knows that one will create the other; both require employees to be authentic and pleasant. Men's Warehouse believes that when a workforce is treated with respect and encouragement, there's no limit to where it can take the company (Denominator, 2006). Happy employees' are more authentic and allows for customer to have an experience that they can feel.Customers who experience the Men's Warehouse culture of excellent customer service, empowered happy employees that creates an environment that is service oriented and authentic which fosters repeatable business. Are always going to come back.. In turn, great service almost always fosters repeatable business. This type of interaction creates a cultural enactment that allows for a positive shared reality for both, employees and customers. The Men's Warehouse embracement of the cultural metaphor is a great example of how culture can create loyalty within organizations. The backbone of the Men's