Air Water Soil Noise Pollution Essay Example

Air Water Soil Noise Pollution Paper Then a non-nuclear event, The Great Smog of 1952 in London, killed at least 4000 people. This prompted some of the first major modern environmental legislation, The Clean Air Act Of 1956. Air pollution Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or damages the natural environment into the atmosphere. The atmosphere is a complex dynamic natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has long been agonized as a threat to human health as well as to the Earths ecosystems. Pollute ants An air pollutant is known as a substance in the air that can cause harm to humans and the environment. Pollutants can be in the form of solid particles, liquid droplets, or gases. In addition, they may be natural or man-made. Pollutants can be classified as either primary or secondary. Usually, primary pollutants are substances directly emitted from a process, such as ash from a volcanic eruption, the carbon monoxide gas from a motor vehicle exhaust or sulfur dioxide released from factories. We will write a custom essay sample on Air Water Soil Noise Pollution specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Air Water Soil Noise Pollution specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Air Water Soil Noise Pollution specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Secondary pollutants are not emitted erectly. Rather, they form in the air when primary pollutants react or interact. An important example of a secondary pollutant is ground level ozone -? one of the many secondary pollutants that make up photochemical smog. Major primary pollutants produced by human activity include: Sulfur oxides (SOX) especially sulfur dioxide, a chemical compound with the formula SIS. SIS is produced by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide. Further oxidation of SIS, usually in the presence of a catalyst such as NON, forms HOSES, and thus acid rain. [2] This is one of the causes for concern over the environmental impact of the use of these fuels as power sources. Nitrogen oxides (Knox) especially nitrogen dioxide are emitted from high temperature combustion. Can be seen as the brown haze dome above or plume downwind of cities. Nitrogen dioxide is the chemical compound with the formula NON. It is one of the several nitrogen oxides. This reddish-brown toxic gas has a characteristic sharp, biting odor. NON is one of the most prominent air pollutants. Carbon monoxide is a colorless, odorless, non- irritating but very poisonous gas. It is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide. Carbon dioxide (CO) a greenhouse gas emitted from combustion but is also a gas vital to living organisms. It is a natural gas in the atmosphere. Odors such as from garbage, sewage, and industrial processes Radioactive pollutants produced by nuclear explosions, war explosives, and natural processes such as the radioactive decay of radon. Secondary pollutants include: Particulate matter formed from gaseous primary pollutants and compounds n photochemical smog. Smog is a kind of air pollution; the word smog is a portmanteau of smoke and fog. Classic smog results from large amounts of coal burning in an area caused by a mixture of smoke and sulfur dioxide. Modern smog does not usually come from coal but from vehicular and industrial emissions that are acted on in the atmosphere by sunlight to form secondary pollutants that also combine with the primary emissions to form photochemical smog. Ground level ozone (03) formed from Knox and Voss. Ozone (03) is a key constituent of the troposphere (it is also an important institutes of certain regions of the stratosphere commonly known as the Ozone layer). Photochemical and chemical reactions involving it drive many of the chemical processes that occur in the atmosphere by day and by night. At abnormally high concentrations brought about by human activities (largely the combustion of fossil fuel), it is a pollutant, and a constituent of smog. Approximately nitrate (PAN) similarly formed from Knox and Voss. Minor air pollutants include: A large number of minor hazardous air pollutants. Some of these are regulated in USA under the Clean Air Act and in Europe under the Air Framework Directive. A variety of persistent organic pollutants, which can attach to particulate matter. Persistent organic pollutants (Pops) are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. Because of this, they have been observed to persist in the environment, to be capable of long-range transport, fasciculate in human and animal tissue, abominating in food chains, and to have potential significant impacts on human health and the environment. Health effects of Air Pollution: The World Health Organization states that 2. 4 million people die each year room causes directly attributable to air pollution, with 1. 5 million Of these deaths attributable to indoor air pollution. Worldwide more deaths per year are linked to air pollution than to automobile accidents. Direct causes of air pollution related deaths include aggravated asthma, bronchitis, emphysema, lung and heart diseases, and respiratory allergies. The worst short term civilian pollution crisis in India was the 1 984 Opal Disaster. Leaked industrial vapors from the union Carbide factory, belonging to Union Carbide, Inc. , U. S. A. , killed more than 2,000 people outright and injured any. Inhere from 50,000 to 600,000 others, some 6,000 of whom would later die from their injuries. The United Kingdom suffered its worst air pollution event when the December 4 Great Smog of 1 952 formed over London. In six days more than 4,000 died, and 8,000 more died within the following months Water pollution Water pollution is the contamination of water bodies (e. G. Lakes, rivers, oceans, groundwater). Water pollution affects plants and organisms living in these bodies of water; and, in almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities. Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds. Causes of water pollution The specific contaminants leading to pollution in water include a wide spectrum of chemicals, pathogens, and physical or sensory changes such as elevated temperature and disconsolation. While many of the chemicals and substances that are regulated may be naturally occurring (calcium, sodium, iron, manganese, etc. ) the concentration is often the key in determining what is a natural component of water, and what is a contaminant. Oxygen- depleting substances may be natural materials, such as plant matter (e. G. Leaves and grass) as well as man-made chemicals. Other natural and anthropogenic us absences may cause turbidity (cloudiness) which blocks light and disrupts plant growth, and clogs the gills of some fish species. Many of the chemical substances are toxic. Pathogens can produce waterborne diseases in either human or animal hosts. Effects of Water Pollution Water pollution is a major problem in the global context An estimated 700 million Indians have no access to a proper toilet, and 1,000 Indian children die f diarrhea sickness every day. Some 90% of Chinas cities suffer from some degree of water pollution, and nearly 500 million people lack access to safe drinking water. Chemical and other contaminants Organic water pollutants include: Detergents Disinfection by-products found in chemically disinfected drinking water, such as chloroform Food processing waste, which can include oxygen-demanding substances, fats and grease Insecticides and herbicides, a huge range of organogenesis and other chemical compounds Petroleum hydrocarbons, including fuels (gasoline, diesel fuel, jet fuels, and fuel oil) and lubricants motor oil), and fuel combustion byproducts, from stemware runoff[1 5] Tree and bush debris from logging operations Volatile organic compounds (Voss), such as industrial solvents, from improper storage. Chlorinated solvents, which are dense non-aqueous phase liquids (Donald), may fall to the bottom of reservoirs, since they dont mix well with water and are denser. Various chemical compounds found in personal hygiene and cosmetic products Inorganic water pollutants include: Acidity caused by industrial discharges (especially sulfur dioxide from power plants) Ammonia from food processing waste Chemical waste as industrial by-products Fertilizers containing nutrientsnitrates and phosphates-?which are found in stemware runoff from agriculture, as well as commercial and residential use[1 5] Heavy metals from motor vehicles (via urban Stemware runoff)[1 5]CO 6] and acid mine drainage Silt (sediment) in runoff from construction sites, logging, slash and burn practices or land clearing sites Land pollution Please help improve this article by adding citations to reliable sources. Unsounded material may be challenged and removed. Land pollution is the degradation of Earths land surfaces often caused by human activities and their misuse of land resources. It occurs when waste is not disposed properly. Health hazard disposal of urban and industrial wastes, exploitation of minerals, and improper use of soil by inadequate agricultural practices are a few factors. Arbitration and industrialization are major causes Of land pollution. Increased mechanization The major increase in the concentration of population in cities, along with the internal combustion engine, led to the increased number of roads and all the infra structure that goes with them. Roads cause visual, noise, light, air and water pollution, in addition to land pollution. The visual and noise areas are obvious, however light pollution is becoming more widely recognized as a problem. From outer space, large cities can be picked out at night by the glow of their lighting so city dwellers seldom experience total darkness. As the demand for food has grown very high, there is an increase in field size and mechanization. The increase in field size makes it economically viable for the farmer but results in loss of person and shelter for wildlife, as hedgerows and copses disappear. When crops are harvested, the naked soil is left open to wind after the heavy machinery has compacted it. Another consequence of ore intensive agriculture is the move to monoculture. This is unnatural, it depletes the soil of nutrients, allows diseases and pests to spread and, in short, brings into play the use of chemical substances foreign to the environment. A pesticide is a substance or mixture of substances used to kill a pest. A pesticide may be a chemical substance, biological agent (such as a virus or bacteria), antimicrobial, disinfectant or device used against any pest. Pests include insects, plant pathogens, weeds, mollusks, birds, mammals, fish, nematodes (roundworms) and microbes that compete with humans for food, story property, spread or are a vector for disease or cause a nuisance. Although there are benefits to the use of pesticides, there are also drawbacks, such as potential toxicity to humans and other organisms. Pesticides are used to control organisms which are considered harmful. For example, they are used to kill mosquitoes that can transmit many potentially deadly diseases like west Nile virus, yellow fever, and malaria disease. They can also kill bees, wasps or ants that can cause allergic reactions. Insecticides can protect animals from illnesses that can be caused by parasites such as fleas. Suicides can prevent sickness in humans that could be caused by moldy food or diseased produce. Mining Modern mining projects leave behind disrupted communities, damages landscapes, and polluted water. Mining also affects ground and surface waters, the aquatic life, vegetation, soils, animals, and the human health. Acid mine drainage can cause damage to streams which in return can kill aquatic life. The vast variety of toxic chemicals released by mining activities can harm animals and aquatic life as well as their habitat. The average mine disturbs over a thousand acres Of land. Construction See the bodies of water. Doing this, natural water filters are damaged. Natural water filters help break down many pollutants before they reach other water bodies. Some that may run off with water and sediments from construction sites are oils, debris, and paint. This can cause damage to soil, aquatic life, and promote hazardous chemicals to get into drinking water. Effects A large percentage of material that is dumped into waters not only destroys habitats for animals but for humans as well. Below is a list of some impacts of land pollution. There are some habitats, where aquatic animals feed and live, o there is a risk of destruction of habitat of aquatic animals. Reduced oxygen levels from decomposition of organic material dumped from drains. Reduced light penetration in the water column, from sediments and excessive algal growth, leading to oxygen depleted water. *Massively changed flow regimes, large fast flows can scour existing habitat and wash species downstream. Increased human health risks, from syringes, broken glass and cans washing onto creek banks and beaches. Reduced aesthetic appeal of areas from litter strewn on banks and beaches, thus reducing recreation and tourist appeal. Acid rain damages trees and other plants. Noise pollution Noise pollution (or environmental noise) is displeasing human, animal or machine-created sound that disrupts the activity or balance of human or animal life. The word noise comes from the Latin word nauseas meaning seasickness. The source of most outdoor noise worldwide is mainly construction and transportation systems, including motor vehicle noise, aircraft noise and rail noise. [1][2] Poor urban planning may give rise to noise pollution, since side-by-side industrial and residential buildings can result in noise pollution in the residential area. Indoor and outdoor noise pollution sources include car alarms, emergency service sirens, mechanical equipment, fireworks, compressed air horns, groundskeepers equipment, barking dogs, appliances, lighting hum, audio entertainment systems, electric megaphones, and loud people. Human health effects Noise health effects are both health and behavioral in nature. The unwanted sound is called noise. This unwanted sound can damage physiological and psychological health. Noise pollution can cause annoyance and aggression, hypertension, high stress levels, tinnitus, hearing loss, sleep disturbances, and other harmful effects. Furthermore, stress and hypertension are the leading causes to health problems, whereas tinnitus can lead to forgetfulness, severe depression and at times panic attacks. Environmental effects Noise can a detrimental effect on animals by causing stress, increasing risk of death by changing the delicate balance in predator/prey detection and avoidance, and by interfering with their use Of sounds in communication especially in relation to reproduction and in navigation. Acoustic overexposure can lead to temporary or permanent loss of hearing. An impact of noise on animal life is the reduction of usable habitat that noisy areas may cause, which in the case of endangered species may be part of the path to extinction. Noise pollution has caused the death of certain species of whales that beached themselves after being exposed to the loud sound of military sonar. Pollution control Pollution control is a term used in environmental management. It means the control of emissions and effluents into air, water or soil. Without pollution control, the waste products from consumption, heating, agriculture, mining, manufacturing transportation and other human activities, whether they accumulate or disperse, will degrade the environment.

Caleb’s Crossing by Geraldine Brooks Essay Example

Caleb’s Crossing by Geraldine Brooks Essay Example Caleb’s Crossing by Geraldine Brooks Essay Caleb’s Crossing by Geraldine Brooks Essay Caleb’s Crossing, by Geraldine Brooks, explores the relationship between Bethia Mayfield, the daughter of a Puritan European colonist, and Caleb, the son of a Wompanog chieftain, as well as Caleb’s journey from being a Native American to learning European customs and ultimately getting an education at Harvard. Throughout the novel, Bethia is drawn to Caleb and his native culture, despite being apprehensive at first. This is because it is such an alien world to her and, shown as being a naturally curious person, she wants to learn more. She eventually finds Caleb to be a blank canvas for her to spread her ideals upon and to teach, since he had no prior experience with European customs and religion. Bethia is very drawn to Caleb because European concepts of religion and culture are so new to him. She even describes him as, â€Å"unschooled†1, showing her acknowledgement of his lack of modern education. During the secret times of their friendship, he questions her about her religion, â€Å"Only one god. Strange, that you English, who gather about you so many things, are content with one and only. And so distant, up there in the sky†2. In response to this, Bethia doesn’t say anything, mostly because she, â€Å"hardly knew what to say to one so lost†3. This is the moment that Bethia really realizes how different Caleb’s culture is from hers, and feels the desire to take him under her wing and share with him what education she has managed to attain despite her gender-based setbacks. The next day, Bethia shares one of her favorite books with Caleb, â€Å"He made me smile, opening it upside down and back to front, but he touched the pages with the utmost care the godliest among us did not tough the Bible with such reverence as he showed to that small book†4. This interaction shows how pleased Bethia is with herself for introducing Caleb to this new concept and how amused she is at his lack of European knowledge. It also shows how Caleb is

Nuisance ( torts law) Essay Example | Topics and Well Written Essays - 1500 words

Nuisance ( torts law) - Essay Example hurt or annoyance of the lands, tenements, or hereditaments of another." The forms of private nuisances are almost countless, thus resulting in the impossibility of any kind of classification (Putney, 1908). A person who owns a proprietorship interest in the land in which nuisance is inflicted can sue and succeed to claims. For instance the person must be an owner or a party, or be in special custody or occupation of it like tenant or under a licence to reside. Exceptions to the above rule may also be present as in the case of Hunter v Canary Wharf.1 The case of Malone v Laskey2 is an exception of the rule that a licensee can sue. In the mentioned case when the wife of the licensee used the toilet a cistern fell on her head due to the trembling of machinery in the nearby property and she was hurt. But when she claimed it failed because her husband was only a licensee and so it could not be proved that she held a proprietary interest in the land herself. But had this case been occurred now she would have succeeded under negligence. But an exception to this is that the wife of a home owner can sue since she also has a beneficial interest in the matrimonial home Hunter v Canary Wharf. Actually according to law jus tertii meaning right of a third person, is not a good defence to sue in a private nuisance. But if a person is in exclusive possession of the land can sue even if title to it cannot be proved Foster v Warblington.3 Till very lately it was resolved, that the complainant must have an interest in the land so that he could sue in private nuisance. But then in the case of Khorasandijian v. Bush4 it was in particular affirmed that it was no longer suitable to restrict the right to sue by indication to proprietary interest in the land. In this case Lord Dillon said the following†¦Ã¢â‚¬ it is ridiculous if in this present age the law that is the making of deliberately harassing and pestering phone calls to a person is only actionable in the civil courts if a

Oppression Term Paper Example | Topics and Well Written Essays - 1000 words

Oppression - Term Paper Example In case oppression consequences accumulate to institutional customs, practices or law, the institution becomes oppressive whether the people running those institutions have or do not have intentions to oppress (Angelo, pp.8) Law and police themselves are example of this type oppression. In such situations the use of word oppression refers relegation of a social category or a certain group by using societal norms, authority and force unjustly with the aim of achieving indoctrination. Through informal or formal institutionalization it attains systematic oppression dimensions. Oppression is basically experienced in form of aftermath of, and shoed in, prevailing form of, if unconscious, In psychology, prejudices, sexism and racism are always studied as peoples’ beliefs which, though not that oppressive, may cause oppression if they are within law or conform to some culture.   From association, in sociology, these biases are always learnt as being systems that have been institutionalized by oppression in societies.in this field, the oppression tools are inclusive of demonization, dehumanization and denigration which at times always generate accusation that is used to defend aggression in contrary to targeted individuals and groups. The human rights concept and U.D.H.R in general were made with the aim of limiting oppression through clarifying what basic freedoms of any state should all individual it If oppression is practiced through force, violence threats or by government agencies violence of NGO with a political intent, is always known as repression. More delicate political forms of oppression or repression can be got by individual investigation or blacklisting. International governance systems that may at times be oppressive are inclusive of absolute monarchy, imperialism, totalitarianism, dictatorship; colonialism and can produce a revolt to the

Analysis Techniques. This is for my Art of Modeling with Spreedsheet Essay

Analysis Techniques. This is for my Art of Modeling with Spreedsheet Class - Essay Example Among the several techniques we do have, I would recommend action oriented techniques to an employee working on their first major project. This is because it gives the ability to weigh whether the project will be successful or not even before he/she takes up the task. Hierarchical Analysis Technique according to David Embrey (2000) is a systematic method of describing how work is organized in order to meet the overall objective of the job. The planning steps are organized and represented from the first to the last step, in an attempt to establish the order with which they are to be carried out, to produce good results. The strengths and weaknesses of each step in the hierarchy are then determined, to find amicable ways of minimizing or dealing with the challenges before they interfere with the whole process. For one to achieve his goal when working on project, he/she must be careful to the small factors that can end up bringing the whole process into a stand still even at the introductory stages. This technique provides for the ability to assess and therefore work on these shortcomings early. This technique can either presented diagrammatically; this is by drawing a diagram to show the stages of the project from the first to the last or in a tabular format where detailed notes on each step are included. This particular analysis technique is the most advisable since it has more advantages compared to the disadvantages. This analysis technique is economical. The Hierarchical description steps developed to the level only required for purposes of the analysis, and not necessarily the whole plan of the project. This therefore relieves the parties involved of the cost which otherwise could have been incurred in developing the whole process. The second advantage of this technique is that the method is often used in the introductory stages to establish whether a project is

Comparative Genomics Research Benefits

Comparative Genomics Research Benefits ABSTRACT The rapidly emerging field of comparative genomics has yielded dramatic results. Comparative genome analysis has become feasible with the availability of a number of completely sequenced genomes. Comparison of complete genomes between organisms allow for global views on genome evolution and the availability of many completely sequenced genomes increases the predictive power in deciphering the hidden information in genome design, function and evolution. Thus, comparison of human genes with genes from other genomes in a genomic landscape could help assign novel functions for un-annotated genes. Here, we discuss the recently used techniques for comparative genomics and their derived inferences in genome biology. INTRODUCTION Comparative genomics is the study of the relationship of genome structure and function across different biological species or strains. Comparative genomics is an attempt to take advantage of the information provided by the signatures of selection to understand the function and evolutionary processes that act on genomes. While it is still a young field, it holds great promise to yield insights into many aspects of the evolution of modern species. The sheer amount of information contained in modern genomes (750 megabytes in the case of humans) necessitates that the methods of comparative genomics are automated. Gene finding is an important application of comparative genomics, as is discovery of new, non-coding functional elements of the genome. Human FOXP2 gene and evolutionary conservation is shown in a multiple alignment (at bottom of figure) in this image from the UCSC Genome Browser. Note that conservation tends to cluster around coding regions (exons). Comparative genomics exploits both similarities and differences in the proteins, RNA, and regulatory regions of different organisms to infer how selection has acted upon these elements. Those elements that are responsible for similarities between different species should be conserved through time (stabilizing selection), while those elements responsible for differences among species should be divergent (positive selection). Finally, those elements that are unimportant to the evolutionary success of the organism will be unconserved (selection is neutral). SCOPE OF COMPARATIVE GENOMICS One of the important goals of the field is the identification of the mechanisms of eukaryotic genome evolution. It is however often complicated by the multiplicity of events that have taken place throughout the history of individual lineages, leaving only distorted and superimposed traces in the genome of each living organism. For this reason comparative genomics studies of small model organisms (for example yeast) are of great importance to advance our understanding of general mechanisms of evolution. Having come a long way from its initial use of finding functional proteins, comparative genomics is now concentrating on finding regulatory regions and siRNA molecules. Recently, it has been discovered that distantly related species often share long conserved stretches of DNA that do not appear to code for any protein. One such ultra-conserved region, that was stable from chicken to chimp has undergone a sudden burst of change in the human lineage, and is found to be active in the developing brain of the human embryo. Computational approaches to genome comparison have recently become a common research topic in computer science. A public collection of case studies and demonstrations is growing, ranging from whole genome comparisons to gene expression analysis. This has increased the introduction of different ideas, including concepts from systems and control, information theory, strings analysis and data mining. It is anticipated that computational approaches will become and remain a standard topic for research and teaching, while multiple courses will begin training students to be fluent in both topic. Chromosomes from two genomes are drawn: human chromosome 1 (drawn with a global zoom factor of 50x) and mouse chromosomes 1-19, X, and Y with mouse chromosome 3 drawn enlarged 10-fold. Syntenic regions between human chromosome 1 and the mouse genome are connected by coloured curves (A), whose geometry and properties can be adjusted dynamically. Thus, all syntenic relationships with mouse chromosome 4 are coloured in orange (B), and all relationships falling within the 80-90 Mb region on human chromosome 1 are coloured in blue (C). Other relationships with alignments larger than 5 kb are coloured dark in grey (D) and all others are shown in light grey. The lines are drawn layered with light grey lines below all others, then dark grey, then blue and then orange. Although approximately 44,000 syntenic relationships are drawn, the use of a selective colour scheme maintains legibility. The outer track (E) is a histogram of the log density of syntenic regions over 100 kb windows on human c hromosome GENOMES ARE MADE OF Although living creatures look and behave in many different ways, all of their genomes consist of DNA, the chemical chain that makes up the genes that code for thousands of different kinds of proteins. Precisely which protein is produced by a given gene is determined by the sequence in which four chemical building blocks adenine (A), thymine (T), cytosine (C) and guanine (G) are laid out along DNAs double-helix structure BENEFITS OF COMPARATIVE GENOMICS Using computer-based analysis to zero in on the genomic features that have been preserved in multiple organisms over millions of years, researchers will be able to pinpoint the signals that control gene function, which in turn should translate into innovative approaches for treating human disease and improving human health. In addition to its implications for human health and well-being, comparative genomics may benefit the animal world as well. As sequencing technology grows easier and less expensive, it will likely find wide applications in agriculture, biotechnology and zoology as a tool to tease apart the often-subtle differences among animal species. Such efforts might also possibly lead to the rearrangement of our understanding of some branches on the evolutionary tree, as well as point to new strategies for conserving rare and endangered species. Comparative Genomics Goals Complete the sequence of the roundworm C. elegans genome by 1998. Complete the sequence of the fruitfly Drosophila genome by 2002. Develop an integrated physical and genetic map for the mouse, generate additional mouse cDNA resources, and complete the sequence of the mouse genome by 2008. Identify other useful model organisms and support appropriate genomic studies. METHODLOGY Genome correspondence Genome correspondence, the method of determining the correct correspondence of chromosomal segments and functional elements across the species compared is the first step in comparative genomics. This involves determining orthologous (genes diverged after a speciation event) segments of DNA that descend from the same region in the common ancestor of the species compared, and paralogous (genes diverged after a duplication event) regions that arose by duplication events prior to the divergence of the species compared. The mapping of regions across two genomes can be one-to-one in absence of duplication events; one-tomany if a region has undergone duplication or loss in one of the species, or many-to-many if duplication/loss has occurred in both lineages. Fitch et al., developed a method called BBH (Best Bidirectional Hits), which identifies gene pairs that are best matches of each other as orthologous. Tatusov et al., further enhanced this method, which matches groups of genes to groups of genes. Understanding the ancestry of the functional elements compared is central to our understanding and applications of genome comparison. Most comparative methods have focused on one-to-one orthologous regions, but it is equally important to recognize which segments have undergone duplication events, and which segments were lost since the divergence of the species. Comparing segments that arose before the divergence of the species may result in the wrong interpretations of sequence conservation and divergence. Further, in the presence of gene duplication, some of the evolutionary constraints that a region is under are relieved, and uniform models of evolution no longer capture the underlying selection for these sites. Thus, our methods for determining gene correspondence should account for duplication and loss events, and ensure that the segments we compare are orthologous Applications Gene identification Once genome correspondence is established, comparative genomics can aid gene identification. Comparative genomics can recognize real genes based on their patterns of nucleotide conservation across evolutionary time. With the availability of genome-wide alignments across the genomes compared, the different ways by which sequences change in known genes and in intergenic regions can be analyzed. The alignments of known genes will reveal the conservation of the reading frame of protein translation. The genome of a species encodes genes and other functional elements, interspersed with non-functional nucleotides in a single uninterrupted string of DNA. Recognizing protein-coding genes typically relies on finding stretches of nucleotides free of stop codons (called Open Reading Frames, or ORFs) that are too long to have likely occurred by chance. Since stop codons occur at a frequency of roughly 1 in 20 in random sequence, ORFs of at least 60 amino acids will occur frequently by chance (5% under a simple Poisson model), and even ORFs of 150 amino acids will appear by chance in a large genome (0.05%). This poses a huge challenge for higher eukaryotes in which genes are typically broken into many, small exons (on average 125 nucleotides long for internal exons) in mammals. The basic problem is distinguishing real genes those ORFs encoding a translated protein product from spurious ORFs the remaining ORFs whose presence is simply due to chance. In mammalian genomes, estimates of h ypothetical genes have ranged from 28,000 to more than 120,000 genes. The internal coding exons were easily identified using Comparative analysis of human genome with mouse genome. Regulatory motif discovery Regulatory motifs are short DNA sequences about 6 to 15bp long that are used to control the expression of genes, dictating the conditions under which a gene will be turned on or off. Each motif is typically recognized by a specific DNA-binding protein called a transcription factor (TF). A transcription factor binds precise sites in the promoter region of target genes in a sequence-specific way, but this contact can tolerate some degree of sequence variation. Thus, different binding sites may contain slight variations of the same underlying motif, and the definition of a regulatory motif should capture these variations while remaining as specific as possible. Comparative genomics provides a powerful way to distinguish regulatory motifs from non-functional patterns based on their conservation. One such example is the identification of TF DNA-binding motif using comparative genomics and denovo motif. The regulatory motifs of the Human Promoters were identified by comparison with other m ammals.Yet another important finding is the gene and regulatory element by comparison of yeast species. Applications of comparative genomics to wheat A number of important major traits requiring elucidation in wheat are essentially non-polymorphic. Thus there is no prospect of creating a mapping population which is the starting point of all positional cloning strategies in most species to date. Moreover given the size of the wheat genome, many traits lie in regions where the gene density per BAC is one or two, making it difficult if not impossible to walk from one wheat BAC to the next. The Ph1 locus (controlling chromosome pairing in wheat) is one such example, in which the starting point was wild type wheat and a mutant carrying a deletion of more than 70Mb (almost the size of the whole Arabidopsis genome). Its phenotype is not easy to score. My group wished to characterise this locus. We created three different types of mutagenised populations, sequenced the equivalent rice Ph1 region, built BAC libraries (all are now available free of IP) for Brachypodium (a small genome species more closely related to wheat), sequenced Brachy podium Ph1 equivalent region, built a hexaploid (CS) (737,000 clones) wheat in collaboration with INRA (providing a further 500,000 clones), exploited Jorge Dubcovskys Tetraploid wheat BAC library, sequenced wheat BACs and defined the tissues in which the Ph1 phenotype is expressed. I will discuss the approaches adopted and resources created. Application of comparative genomics to the analysis of vertebrate regulatory elements Gene regulatory regions (also known as cis-regulatory modules) in vertebrates are poorly understood and annotated by comparison with protein-coding sequences. The short and degenerate sequences of regulatory elements and their distribution over large intergenic and intronic regions pose a major challenge to genomics scientists. Comparative genomics can be used to identify putative regulatory regions, and to analyse regulatory regions into their constituent transcription factor binding sites. There is need for high throughput assay systems to analyse the function of predicted vertebrate gene regulatory regions Other applications Comparative genomics has wide applications in the field of molecular medicine and molecular evolution. The most significant application of comparative genomics in molecular medicine is the identification of drug targets of many infectious diseases. For example, comparative analyses of fungal genomes have led to the identification of many putative targets for novel antifungal. This discovery can aid in target based drug design to cure fungal diseases in human. Comparative analysis of genomes of individuals with genetic disease against healthy individuals may reveal clues of eliminating that disease. Comparative genomics helps in selecting model organisms. A model system is a simple, idealized system that can be accessible and easily manipulated. For example, a comparison of the fruit fly genome with the human genome discovered that about 60 percent of genes are conserved between fly and human. Researchers have found that two-thirds of human genes known to be involved in cancer have counterparts in the fruit fly. Even more surprisingly, when scientists inserted a human gene associated with early-onset Parkinsons disease into fruit flies, they displayed symptoms similar to those seen in humans with the disorder, raising the possibility that the tiny insects could serve as a new model for testing therapies aimed at Parkinsons. Thus, comparative genomics may provide gene functional annotation. Gene finding is an important application of comparative genomics. Comparative genomics identify Synteny (genes present in the same order in the genomes) and hence reveal gene clusters. Comparative genomics also helps in the clustering of regulatory sites, which can help in the recognition of unknown regulatory regions in other genomes. The metabolic pathway regulation can also be recognized by means of comparative genomics of a species. Dmitry and colleagues have identified the regulons of methionine metabolism in gram-positive bacteria using comparative genomics analysis. Similarly Kai Tan and colleagues have identified regulatory networks of H. influenzae by comparing its genome with that of E. coli. The adaptive properties of organisms like evolution of sex, gene silencing can also be correlated to genome sequence by comparative genomics. CONCLUSION The most unexpected finding in comparing the mouse and human genomes lies in the similarities between junk DNA, mostly retro-transposons, (transposons copied from mRNA by reverse transcriptase) in the two species. A survey of the location of retrotransposon DNA in both species shows that it has independently ended up in comparable regions of the genome. Thus junk DNA may have more of a function than was previously assumed. High performance computing tools help in comparing huge genomes. Because of its wide applications and feasibility, automation of comparing genomics is possible. Such Comparisons can aid in predicting the function of numerous hypothetical proteins. REFERENCES en.wikipedia.org/wiki/Comparative genomics www.ncbi.nlm.nih.gov www.springer.com

Cloning is Ethically and Morally Wrong :: Argumentative Persuasive Topics

Cloning is Ethically and Morally Wrong The question shakes us all to our very souls. For humans to consider the cloning of one another forces them all to question the very concepts of right and wrong. The cloning of any species, whether they be human or non-human, is ethically and morally wrong. Scientists and ethicists alike have debated the implications of human and non-human cloning extensively since 1997 when scientists at the Roslin Institute in Scotland produced Dolly. No direct conclusions have been drawn, but compelling arguments state that cloning of both human and non-human species results in harmful physical and psychological effects on both groups. The following issues dealing with cloning and its ethical and moral implications will be addressed: cloning of human beings would result in severe psychological effects in the cloned child, and that the cloning of non-human species subjects them to unethical or moral treatment for human needs. The possible physical damage that could be done if human cloning became a reality is obvious when one looks at the sheer loss of life that occurred before the birth of Dolly. Less than ten percent of the initial transfers survive to be healthy creatures. There were 277 trial implants of nuclei. Nineteen of those 277 were deemed healthy while the others were discarded. Five of those nineteen survived, but four of them died within ten days of birth of sever abnormalities. Dolly was the only one to survive (Fact: Adler 1996). If those nuclei were human, "the cellular body count would look like sheer carnage" (Logic: Kluger 1997). Even Ian Wilmut, one of the scientists accredited with the cloning phenomenon at the Roslin Institute agrees, "the more you interfere with reproduction, the more danger there is of things going wrong" (Expert Opinion). The psychological effects of cloning are less obvious, but none the less, very plausible. In addition to physical harms, there! are worries abou t the psychological harms on cloned human children. One of those harms is the loss of identity, or sense of uniqueness and individuality. Many argue that cloning crates serious issues of identity and individuality and forces humans to consider the definition of self. Gilbert Meilaender commented on the importance of genetic uniqueness not only to the child but to the parent as well when he appeared before the National Bioethics Advisory Commission on March 13, 1997. He states that "children begin with a kind of genetic independence of [the parent].