Friday, January 31, 2020
Prairie Dogs Essay Example for Free
Prairie Dogs Essay â€Å"Prairie dogs have a significant effect on biological diversity in prairie ecosystems. More than 200 species of wildlife have been associated with prairie dog towns, with over 140 species benefitting directly†¦Ã¢â‚¬ (Williams 34). Terry Tempest Williams, author of the book â€Å"Finding Beauty in a Broken World,†delivers a strong argument as to why prairie dogs should be protected. Prairie dogs contribute to the welfare of animals around them in many ways. They create diversity, kinship and community. Williams also states, â€Å"They embody two million years of evolving intelligence†(Williams 33). They are social creatures, and they all live in towns and villages. They kiss when they greet each other, as a way of distinguishing one from another. Once recognized, they will engage in nuzzling and other affectionate grooming behaviors. They also are able to distinguish the light from dark. Dogs kept in zoos become so tame, visitors may pet them. Williams gives an example of this in her book when she visits a zoo in North Carolina. She witnesses a man talking to and affectionately petting the belly of a prairie dog (Williams 66). They are not just rodents and they can be extremely humane and friendly. â€Å"Prairie dogs, like beavers, are a keystone species- that is one that significantly alters the ecosystem and provides habitat for auxiliary species†(Outwater 73). In the book, â€Å"A Sea of Grass,†by Outwater, she delivers a strong argument as to why prairie dogs are beneficial to the grassland ecosystem. Prairie dogs create habitats for other species, because over 200 species live nearby prairie dog burrows. The burrows are never built all the same. Some have special pockets, turn-around rooms, and others have chambers with grass. The temperature underground is convenient for species living there, being as it is warm in winter, and cooler in the summer. Outwater presents a valid reason for protecting the rodents. For example, she states,†In the process of constructing their towns of tunnels, the prairie dogs once moved tons of subsoil above ground, where they mixed it with top soil and organic matter.. †(Outwater 74). Many species benefit from this churning of the soil because it creates grasses which are richer in protein. The prairie dogs also help to increase the amount of water that makes it underground, which enhances the productivity of the soil. Concurrently, more water goes into rivers and streams. Another component of prairie dogs is that they are social, loving creatures. They engage in their own communication. When they see a predator, they make a bark that signals all the dogs around to protect themselves. Prairie dogs provide burrows not only for themselves, but for other animals as well. They also aerate the soil and contribute to water drainage underground. Prairie dogs eat grass, which in turn shocks the landscape into greater, richer productivity. Prairie dogs need to be protected because they are such an important species to the grassland ecosystem and they are on the brink of extinction. â€Å"†We are living amid a sixth extinction,†writes Niles Eldredge, a curator at the American Museum of Natural History,†one that, according to the Harvard biologist E. O. Wilson, is costing the Earth some 30,000 species a year.. At this rate, the vast majority of the species on earth today will be gone by the next millennium††(quoted in Williams 71). All species rely on another species for survival. If prairie dogs were to become extinct, many other species and habitats would be at stake also. Some species affected by the decline of prairie dogs include, but are not limited to: the black-footed ferret, mountain plovers and owls, golden eagles, foxes, ferruginous hawks, and deer mice. (Williams 57). The grassland ecosystem as a whole would be at stake, seeing as how every single species contained in it relies upon one another for survival. The author Outwater also believes there is a lot at stake if the dogs become extinct. She believes that if prairie dogs are eliminated, the productivity of grasslands decreases. Species such as turtles, skunks, snakes, toads, prairie chickens, tiger salamanders, rabbits, eagles, hawks, coyotes, foxes, and many more will not have a place to abide. Also, the water will be at stake because less water would be seeping underground. By less water making it underground, there would ultimately be less water going to streams and rivers. Both Outwater and Williams have extreme arguments as to why prairie dogs should be protected. Their arguments may differ in many ways, but they agree on a few core points. They both agree that these rodents create habitats for other species, and that they are definitely a keystone species. They prune grass, in turn creating more beneficial food sources for different species. They heighten the water drainage into the subsoil, in turn filling the streams and rivers. They also create diversity, within the plants and the animals surrounding them. They are not just pests either, as agreed upon by Outwater and Williams. They have their own language and ways of communicating. They exhibit affectionate behavior towards each other and engage in grooming activities and kissing. Even though Williams and Outwater arrive at the same points, their methods of proving them are different. Williams proves her points through mosaics, saying the different broken pieces make up something greater. The different species involved in the grassland ecosystems all play an important role in the bigger picture. Outwater has a different technique. She shows prairie dogs in comparison to the buffalos, water systems, and other species of the grasslands. She also goes into greater depth of the prairie dog environment as a whole. Although both authors have valid points, I find Williams’ argument more compelling. Her quotes and examples convince one that prairie dogs really do need to be protected. She states, â€Å"Prairie dogs create diversity. Destroy them, and you destroy a varied world†(Williams 37). From the plants, to the animals in their grassland ecosystem, prairie dogs bring about diversity in everything. Williams uses mosaics as a way to describe the dogs as a part of their ecosystem. The prairie dogs are an essential part of the grasslands and Williams makes her argument more compelling by comparing them to mosaics. However, both authors come to the same conclusion. Prairie dogs are a species whose very presence contributes to the diversity of life and whose extinction would result in the extinction of species dependant on it. Extra Credit: Williams relates prairie dogs to mosaics by proving that they are a part of something bigger than themselves. Mosaics are composed of several â€Å"broken†pieces, making up one beautiful piece. Prairie dogs are just one essential part of the grassland ecosystems. Even though they are just one part, they are important to everything else around them. Williams uses mosaics as a way to describe the dogs as a part of their ecosystem. She also compares and contrasts the rules of mosaics with prairie dogs and their towns. She states, â€Å"Tesserae are irregular, rough, individualized, unique. Prairie dogs literally change the land with their hands†¦ Many colors are used to create one color from afar. Different hues from the same color were always used in ancient mosaics. Prairie dogs have a significant effect on biological diversity in prairie ecosystems. More than 200 species of wildlife have been associated with prairie dog towns, with over 140 species benefitting directly †(Williams 34). If one piece of the mosaic is missing, it is not a mosaic. Every single piece of the mosaic directly benefits and depends on the others, just like in grassland ecosystems. Every species of animal depends on and directly benefits from another. If prairie dogs were to become extinct, there are so many other animals that would be at stake also. Their burrows provide protection. Their pruning of the grasses creates a better quality of food for others. Their digging and aerating of the soils allows for more water to seep down and be absorbed by the earth, which in turn provides water for streams and rivers. Williams relates prairie dogs to mosaics in a very compelling argument. She knows that if prairie dogs were to face extinction, an essential part of the grassland ecosystem would be missing, and the rest of the grassland would be directly, negatively affected.
Thursday, January 23, 2020
Plant hormones Essay -- essays research papers
Plant hormones are specialized chemical substances produced by plants. They are the main internal factors controlling growth and development. Hormones are produced in one part of a plant and transported to others, where they are effective in very small amounts. Depending on the target tissue, a given hormone may have different effects. Plant hormones play an integral role in controlling the growth and development of plants. A plant hormone is generally described as an organic compound synthesized in one part of the plant and translocated to another part, where in low concentrations elicits a physiological response. There are five generally recognized classes of plant hormones; some of the classes are represented by only one compound, others by several different compounds. They are all organic compounds, they may resemble molecules which turn up elsewhere in plant structure or function, but they are not directly involved as nutrients or metabolites. Hormone     Source     Action Auxins     apical meristem (only moves down), embryo of seed, young leaves     †¢Ã‚     Control of cell elongation †¢Ã‚     apical dominance (prevents lateral buds) †¢Ã‚     prevents abscission †¢Ã‚     continued growth of fruit †¢Ã‚     cell division in vascular and cork cambium --formation of lateral roots from pericycle --formation of adventitious roots from cuttings Gibberellins     Roots and young leaves     †¢Ã‚     Cell (stem) elongation (works in stems and leaves, but not roots) †¢Ã‚     breaking seed/bud dormancy †¢Ã‚     stimulating fruit set Cytokinins     roots, embryos, fruits actively growing     †¢Ã‚     Promote cell division --signal axillary/lateral bud growth --prevent leaf abscission †¢Ã‚     chloroplast development †¢Ã‚     breaking dormancy in some seeds †¢Ã‚     enhance flowering †¢Ã‚     promote fruit development Abscissic Acid    ... ...ascade ultimately resulting in modification of enzyme activity, altered metabolic processes, and different phenotypes. One thing plant hormones specifically control is gene expression. The exact mechanisms by which hormones regulate gene expression are poorly understood. Gene expression is part of a large amplification process. This process involves repeated transcription of DNA resulting in many copies of mRNA (1st amplification step); mRNA is processed and enters the cytoplasm where it is translated many times by ribosomes into a gene product such as an enzyme (2nd amplification step); enzymes are modified to become functional and capable of high catalytic activity even at low concentrations. They catalyze the production of many copies of an important cellular product (3rd amplification step). It is likely that gene regulation is affected by certain enzymes after initial hormone binding. Genes may be altered by secondary and tertiary messengers of a cellular cascade as well. Hormones may indirectly control gene expression through these enzymes and messengers at a number of control sites such as transcription, mRNA processing, mRNA stability, translation, and post-translation Plant hormones Essay -- essays research papers Plant hormones are specialized chemical substances produced by plants. They are the main internal factors controlling growth and development. Hormones are produced in one part of a plant and transported to others, where they are effective in very small amounts. Depending on the target tissue, a given hormone may have different effects. Plant hormones play an integral role in controlling the growth and development of plants. A plant hormone is generally described as an organic compound synthesized in one part of the plant and translocated to another part, where in low concentrations elicits a physiological response. There are five generally recognized classes of plant hormones; some of the classes are represented by only one compound, others by several different compounds. They are all organic compounds, they may resemble molecules which turn up elsewhere in plant structure or function, but they are not directly involved as nutrients or metabolites. Hormone     Source     Action Auxins     apical meristem (only moves down), embryo of seed, young leaves     †¢Ã‚     Control of cell elongation †¢Ã‚     apical dominance (prevents lateral buds) †¢Ã‚     prevents abscission †¢Ã‚     continued growth of fruit †¢Ã‚     cell division in vascular and cork cambium --formation of lateral roots from pericycle --formation of adventitious roots from cuttings Gibberellins     Roots and young leaves     †¢Ã‚     Cell (stem) elongation (works in stems and leaves, but not roots) †¢Ã‚     breaking seed/bud dormancy †¢Ã‚     stimulating fruit set Cytokinins     roots, embryos, fruits actively growing     †¢Ã‚     Promote cell division --signal axillary/lateral bud growth --prevent leaf abscission †¢Ã‚     chloroplast development †¢Ã‚     breaking dormancy in some seeds †¢Ã‚     enhance flowering †¢Ã‚     promote fruit development Abscissic Acid    ... ...ascade ultimately resulting in modification of enzyme activity, altered metabolic processes, and different phenotypes. One thing plant hormones specifically control is gene expression. The exact mechanisms by which hormones regulate gene expression are poorly understood. Gene expression is part of a large amplification process. This process involves repeated transcription of DNA resulting in many copies of mRNA (1st amplification step); mRNA is processed and enters the cytoplasm where it is translated many times by ribosomes into a gene product such as an enzyme (2nd amplification step); enzymes are modified to become functional and capable of high catalytic activity even at low concentrations. They catalyze the production of many copies of an important cellular product (3rd amplification step). It is likely that gene regulation is affected by certain enzymes after initial hormone binding. Genes may be altered by secondary and tertiary messengers of a cellular cascade as well. Hormones may indirectly control gene expression through these enzymes and messengers at a number of control sites such as transcription, mRNA processing, mRNA stability, translation, and post-translation
Wednesday, January 15, 2020
The Drug Crime Relationship
There is no question that drugs and crime are related, however difficulty stands when trying to establish a causal connection between the two. According to Ronald Akers, ‘compared to the abstaining teenager, the drinking, smoking and drug taking teen is much more likely to be getting into fights, stealing, hurting other people and committing other delinquencies’ (Gottfredson and Hirschi, 1990).At a surface level, drugs and crime are linked as it is a criminal offence to possess certain substances unlawfully, however when looking deeper, where drugs are said to cause, influence or be associated with offending behaviour the subject becomes quite unclear. Three major models exist that examine the drugs-crime link and will be discussed thoroughly throughout this essay. Firstly is the model that suggests drug use leads to crime and offending behaviour.It offers the explanation that drug-users are enslaved, or behaving in ways which satisfy the craving which very often leads t o participating in criminal behaviour. A second model explains that crime leads to drug use, and the third that drug use and crimes have a common aetiology. Throughout this essay these models will be examined deeply in order to try and best understand the relationship between drug use and offending behaviour. The idea that drug use leads to crime is by far the most believed and most popular idea out of the three.The reasons for this may lie in its heavy belief from the media and the government. It is sometimes represented as a direct causal effect and sometimes as just an association. There does stand much evidence in support of this theory, however no research identifies a direct causal link which will be noted later. One study carried out in this field gave the police power to perform drug tests on detainees in police custody and gave the courts the power to order the drug testing of offenders under the supervision of the probation service.In total they carried out a collective of 1,835 tests and found positive results in 63% of those tested in London, 58% of those tested in Nottingham and 47% of those tested in Strafford and Cannock. For those on probation over half tested positive ( Mallender et al. 2002, citied in Bean 2008). While support stands for this view, variations exist in the way drug use is said to cause crime.Three broad categories exist, firstly the psychopharmacological explanations, secondly the economic explanations and thirdly the drug-lifestyle explanation. Firstly the psychopharmacological explanations consider the effects of the drug chemicals have upon the human organism and what the behavioural outcomes may be. For example, the psychopharmacological model says that drugs cause violence because of their direct effects, as an effect users become impatient, irritable, energetic and irrational often leading to criminal behaviour.Goldstein (1985) believes the psychopharmacological model to be a direct effect model and argues that ‘so me individuals, as a result of short or long term ingestion of specific substances, may become excitable, irrational, and may exhibit violent behaviour’. Brochu (2001) claims that many drugs ‘act on specific areas of the nervous system, including the frontal lobe and the limbic system, where the centres of aggressiveness and impulsiveness are located’ (Bennett and Holloway).While these are considered to be direct and instantaneous effects of drug use, in practice the psychopharmacological effects of drugs on crime are expected to function indirectly. Parker and Auerhahn (1998) stress from their research the overwhelming importance of the context in the relationship between substance use and violent behaviour, and as MacCoun et al (2002) claim ‘it may be that no drug is sufficient to produce aggression in isolation from psychological and situational moderators. ’ (Bennett and Holloway).The second variation on how ‘drugs cause crime’ is th e economic explanation. This is very often referred to as the economic necessity argument which simply says drug users will commit crime for economic benefit in order to fund their drug addiction. Crimes associated with this explanation are most commonly property crime including theft, shoplifting, burglary and fraud; however there are many links with violent crimes. One explanation for this is that habitual drug users face problems raising cash and therefore prefer to perform street robberies. Baumer et al. 1998) argues that this type of robbery draws cash directly and is more easily perpetrated during the hours of darkness when the streets are less crowded. Cash carries the advantage of being easily concealed and does not have to be exchanged at a discount unlike stolen property. (Bennett and Holloway). The third variation is the drug-lifestyle explanation. The theory focuses in particular, on the relationship between drug-using lifestyles and violence. It offers the explanation t hat drug abusers are living within a community which is more likely to be a violent one when compared to a drug free community.The drug using community is one that is notoriously violent, especially when considering punishments for failing to pay debts, territory disputes and selling adulterated drugs. Other ideas focusing on lifestyle but not on violence consider that drug users often do not participate in the legitimate economy and therefore the likelihood of them becoming involved in criminal activity is increased, and also they would be exposed to situations that encourage crime. (Bennett and Holloway).When considering the idea that crime leads to drug use, the research is scarce by comparison. If crime leads to drugs use there will be no reduction in criminality even with the successful treatment of the drugs problem. If crime leads to drug use then treatment should be directed at reducing the criminality, and the drug problem will be correspondingly reduced (Hammersley et al. 1989, cited in Bean p. 39). Researchers are heavily interested in finding what came first; the drug problem or criminality?Early British studies found that about 50% of heroin addicts were antecedently delinquent but, of course, 50% were not (Bean 1971). However, some researchers are sure they know the truth. Korf et al. (1998) belief that there is empirical support for thinking prior criminal involvement increases one’s chance of getting into drugs, claiming ‘many current addicts have set out on a criminal path at an early age and before their first dose of heroin. These pre-drug criminals turn out to be the group most likely to generate their income from property crime. ’ (Bean p. 9) As noted, there doesn’t stand as much research into this field as the previous (drug use leads to crime) however, the theories which do stand can be divided again roughly into the three same categories, psychopharmacological explanations, economic explanations and criminal l ifestyle explanations. Explaining this idea through psychopharmacological means, researches such as Menard et al (2001) claim that criminals use drugs as a form of chemical recreation to celebrate successful crimes, pretty much in the same way people use alcohol to celebrate a special occasion, (Bennett and Holloway, p. 6). In another way according to the psychopharmacological model, people who have planned crime might turn to drugs to enable themselves to carry out the planned actions. It is possible therefore to say that crime causes drug use because without the drug it is possible the crime wouldn’t have occurred. The economic perspective explanation simply says crime causes drug use through crimes resulting in surplus cash which enable the offenders to buy drugs, unds which would not be available were it not for criminal activity (tim newburn). The criminal lifestyle explanations suggest that a criminal lifestyle tends to involve drug use either via sub-cultural values, t hrough available opportunities or as a result of self-medication. Criminal activity in subcultures provides ‘the content, the reference group and the definitions of a situation that are conclusive to the subsequent involvement in drugs’ (White 1990: 223, Bean p. 39).Evidence for this comes from a small number of studies, quoted by White, where she says the individual is placed in an environment which is supportive of drug use, and it is the desire for sub-cultural status rather than a need for a drug which leads to the individual committing crimes. The available opportunities idea goes hand in hand with the situational crime theory, which states the individual makes a rational choice, essentially weighing up the pros and cons of their actions. If the pros outweigh the cons then the person will display offending behaviour.Supporters of situational crime prevention would say that crime leads to drug taking, and therefore by modifying crime hotspots and the environment, an d by dealing with characteristics and location of suitable targets, drug taking can be reduced. The Third, that drug use and crimes have a common aetiology. This theory rejects strongly the simple causal explanation that drugs use leads to crime or the other, crime leads to drug use claiming the relationship to be far more complex than this.Rather, this suggests a common cause between the two, enforcing arguments that there are other factors involved which help explain both forms of behaviour. ‘Such factors may take various forms including aspects of personality or temperament, aspects of a person’s interpersonal social world (family, friends, peers) or some feature of the social environment in which they live’ (Newburn). These common factors can be grouped into three categories – psychological, social and environmental.Psychological factors can be related to a persons genetics or temperament character. Many explanations focus on the role of psychological factors as distal causes, which are those factors operating in the past that predispose people to act in certain ways. The social factors focus on social relationships and the way in which these may have an effect on crime and drug use. Peer pressure is said to be a major sway on a persons behaviour with regard to crime and illicit drug use. As White (1990) concludes in Bennet and Holloway (2005) ‘Peer group nfluences are the best predictors of delinquency and drug use. ’ With regards to the environmental explanation, factors within the environment are said to play a role in the drug-crime link. The social disorganization theory developed by Shaw and Mckay in 1942 was applied to help try and best explain the drug – crime link in 2000 by White and Gorman, who argue that rates of violence and exposure to drugs was greatest in less affluent areas, densly populated areas, racially segregated areas and those that are composed of a transient population.A rather sociolo gical version of the common cause idea is a variation of the sub-cultural theory which sees drug use as a learned behaviour. Behavioural norms are learned from generation to generation and become internalised, which lead individuals within particular families or social groups to behave in the same manner with the same patterns of offending. To conclude, this essay has highlighted much evidence to suggest that drug use leads to crime, and the opposite, that crime leads to drug use.People who try illicit drugs are more likely to display offending behaviour than others; however there is no persuasive research evidence of a causal link between drug use and offending within the majority of drug users. Much of the research provides conflicting explanations of the topic, however there does stand some common ground. There are no inconsistencies in the idea that drug use might sometimes cause crime and crime may sometimes cause drug use.However, as a general rule, research provides evidence sufficient to establish an association as appose to a direct causal link. This essay has also looked at the idea of a common cause or common aetiology between the relationship between drug use and offending behaviour, which is the idea that other factors such as personality, temperament, family or friends influences play a part in an individual’s lifestyle and choices.
Tuesday, January 7, 2020
Essay on the Dark Side of the Mind Exposed in Cask of...
The Dark Side of the Mind Exposed in Cask of Amontillado A wrong is unredressed when retribution overtakes its redresser. It is equally unredressed when the avenger fails to make himself felt as such to him who has done the wrong. With that statement, Montresor begins his tale of revenge deciding that the act must be slow and sweet and that in order to fully enjoy it, his adversary must be aware of his intentions. Hidden within those same few lines, lies not only this horrid plan, but also the true interest of its true author. In his Cask of Amontillado, Edgar Allen Poe reveals his supreme interest in the dark side of the human mind and heart. nbsp; Much of what a story means, much of its effect on the reader depends on†¦show more content†¦He is only concerned with attempting to understand the mind of Montresor as he commits the ultimate dark act of murder. nbsp; Throughout the story, Montresor shows that the murder was what is now called in the first degree - it was clearly preplanned and intentional. By giving [the attendants] orders not to stir from the house, Montresor shows that he was very aware of his actions. Even the placement of the bricks and mortar, as well as the clever concealment of the trowel reflect the final execution of a well thought out plan. In dialogue, Montresor also reveals his plan: Fortunato: the cough is a mere nothing; it will not kill me. I shall not die of a cough. Montresor: True - true. Montresor says that it is true. Fortunato will not die of a cough, he will die at the hand of Montresor. The deep-seated hatred necessary for the preplanned extinguishing of anothers life shows this dark side which Poe so wishes to be understood. Poe seems to suggest that even if the readers have not physically carried out such a hideous act as that of Montresor, they have in their imaginations. nbsp; Even the calm way the story is related by Montresor causes the reader to wander further into the mind of the murderer - further into the dark side of the mind and of the heart. With the line for the half of a century no mortal has disturbed the bones, a new perspective on the story emerges. But even when the fact that the story was
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