Iron and silk Essay Example | Topics and Well Written Essays - 750 words - 1

Iron and silk - Essay Example In the book, several times, people exert authority over him in a way he finds frustrating. This essay seeks to address several issues raised by Salzam in his book Iron and Silk, such as people frustrating him and others through exerting authority over them in a brutal way. One incident was when he killed a large rat during a lesson out of pure reflexes. A student suggests that he takes the rat across to the rat collection center so that he can receive a reward. He does not however get it as he is told that the reward is restricted to students killing rats in the dormitory. Later on a student explains to him that the official statements concerning rats is that they were no longer existent and that only internal documents that foreigners cannot read admit to the rat problem. Since he had killed the rat, he could not be rewarded as that would imply that they admit to the presence of rats and they could be criticized. Usually, I have found people to do what would appear to be a silly thing in order to protect how others think about them. It is in their nature to want to control the information that other people receive about them which informs their opinions towards them, for example how people carefully select what to post on face book. In this scenario, the institution would rather have denied the rats’ presence to an outsider that had seen one and obviously knotted their being than to admit to the public that they actually war. To them, it was a case of choosing the better evil. His restraint in this situation is however recommendable as he refuses to dwell for long on his grievances. This they probably did to protect their own reputation as an institution. It has been argued that actions that are felt to be wrong produce a need to withhold knowledge of them from others, which produces guilt and hostility. This implies that if one has been unable to solve a problem well and satisfactorily, they feel ‘forced’ to commit another action that

Philosophy Essay Example | Topics and Well Written Essays - 500 words - 28

Philosophy - Essay Example Gene flow can happen either through hybridization or by exchange of DNA sequence by bacteria or virus. Bacteria and virus have the ability to transfer genes across specie. The gene flow can also result in the formation of a combined gene pool which will have both the characteristics of the two population groups. Thus the barriers to gene flow as well as the gene flow itself, both have the potential to bring about species diversity and take evolution ahead. Genetic drift is the change in the frequency of a DNA sequence, usually called allele. This phenomenon totally depends on chance. When a new member is born in a species, the alleles that will be taken up into the genetic make up of that individual will be through a process of random sampling. And if that individual lives enough to reproduce, only then there is an assurance that the specific alleles in his genes have a scope to survive. It is in this way that the allele frequency changes within a population and this leads to genetic variance within species. Thus a new generation may emerge which may either have lost one genetic trait or may have strengthened one genetic trait of the species, more visibly. Mutations are sudden changes in DNA sequence, of an organism, caused by many factors including, viruses, radiation, mutagenic chemicals, errors during DNA replication, transposition of DNA sequences within the genome, and errors in cell division while sexual reproduction. It has been proved that mutations have a great role in the process of evolution, that is, in the birth of new species, particularly, in smaller life forms like viruses and bacteria. But for higher life forms, mutations are harmful or neutral with respect to the survival of the specie. 2. Race is a social construct rather than a scientific classification. All human beings belong to the species, Homo Sapiens. The concepts and categories of race have not been constant and these have been changing in the history of human kind.

Systems Analysis and Design_Aug13 Assignment - Nancy's Novelty Cakes

Systems Analysis and Design_Aug13 - Nancy's Novelty Cakes - Assignment Example 24 Schedule 24 b) Spreadsheet program 25 Task 3- B Graph 26 Increase in Sales Each Year 26 The above given graph clearly indicates that this investment will bring increase to expected sales. 27 Sales v/s Revenue 27 27 Above given graph demonstrates the relationship between sales and revenue. This graph clearly shows an increase in sales due to the increase in revenue. 27 Task 3- C 27 In this analysis I have shown a relationship between different variables such as the overall sales and total revenue. These relationships are demonstrates over a progress of four years and in a steady fashion. These relationships outline a steady line of increase in sales and overall increase in revenue after 2 years. ... ign 33 References 34 Introduction Nancy’s Novelty Cakes is a small confectionery business, which is expert in making novel and special occasion cakes for customers. Up till now, this company has been using a traditional approach for the management of its business operations. In this scenario, it has developed and maintained a file of cakes designs along with costs associated with those cakes. With the passage of time the management realized that this traditional approach is not useful for the successful management of business operations. Hence, they have decided to develop and implement a new technology based system. In this scenario, Nancy’s Novelty Cakes business is looking for an effective way to replace its old manual system they have had for the last 5 years with a new computerised system. I am a member of IT Company that is specialized in design and development of computerised business systems. Our consultancy firm has won a contract from this client. In this case our team is responsible for the development and implementation of a new technology based system for the better corporate operational and procedures management. This report presents a detailed analysis of some of the important aspects associated with the development and implementation of this new system. This report will discuss the requirements specification and design related aspects of Nancy Nancy’s Novelty Cakes business. This report is divided into different tasks and each task addresses specific topic. Task 1 a) System lifecycle model Software/system development lifecycle or simply the SDLC is a theoretical outline or process that demonstrates the phases or steps required for the development of a software application. In fact, this process outlines all the steps from preliminary feasibility

African american history Essay Example | Topics and Well Written Essays - 250 words

African american history - Essay Example They include Igbo, Wolof, Mande, Akan, Fon, Bakongo and Makua amongst others. This people did away with their tribal differences and forged a new culture and history that was acreolization to their pasts and present. This African American developed a culture that was referred to as a black culture. The culture is deeply rooted in Africa. This culture has affected the United States as part or distinct from its culture. It has enormously influenced the American culture as whole. Although slavery restricted the practice of African American culture, their beliefs, values, and practices survived and have blended or modified the white culture (Joanne 64). Within 18th and19th centuries, both white and black Americans worked to stop slavery (Franklin and Higginbotham 285). Many antislavery societies were organized to fight so that slaves could be freed. Main slaveholders considered freeing slaves to disrupt British trade. Most notably, Prince Hall a free slave submitted petitions to end slavery but it was largely ignored. The other challenge of revolution against slavery set in when President Washington stopped recruitment of soldiers into the revolutionary army. The free slaves participated in the revolution against slavery and participated in American revolutionary war. America won the battle against the British rule (Franklin and Higginbotham 327). President Thomas Jefferson referred to slavery as ‘abominable crime’ and declared the independence of slaves yet he was a life long slaveholder. During constitutional convention of 1787, there was declaration of freedom of equality between the blacks and

Economics Practice Problems Essay Example for Free

Economics Practice Problems Essay 1. Which of the following would most likely cause equilibrium quantity and price of x to rise? (a)a fall in income when the income elasticity of demand for x is positive Wrong. This will cause a drop in demand and thus a fall in quantity. (b)a fall in the price of complementary product y Correct. A fall in a complementary product will cause a rise in demand for that product â€Å"y† and thus a rise in demand of product â€Å"x† (see graph). (c)a fall in the price of substitute product Z Wrong. A fall in a substitute product will cause an increase in the demand for product Z and thus a fall in the demand for product x. (d)an increase in the cost of producing x Wrong. The increase in production cost will decrease supply (see graph). (e)a fall in the price of product A which is jointly produced with x Wrong. A fall in price of a jointly produced product will give the incentive to produce more A. If this incentivizes the producer to also increase the supply of x, the effect would be opposite as in (d): less price and more quantity. 2. Which of the following is not characteristic of a cartel situation? (a)While disagreement over production quotas may occur, once set, there is little incentive for cheating. Correct answer. In a cartel there are incentives to cheat (all other are characteristics of a cartel). (b)There is an incentive for some producers not to join. (c)Entry of new producers is a threat to the cartels viability. (d)Long-run demand elasticity can pose an obstacle to success. (e)Output must be less than the competitive case for the cartel to be effective.

Causes of Chronic Migraines

Causes of Chronic Migraines Headache is pain in any part of the head that can occur suddenly or gradually and produce a varying amount of pain; in fact, it is the most common form of pain in the United States (U.S. Department of Health and Human Services, 2014). Headache is often divided into two categories, primary and secondary (U.S. Department of Health and Human Services, 2014). A primary headache is one that is due to the headache itself, it is not caused by another problem (U.S. Department of Health and Human Services, 2014). The three types of primary headache include tension headaches, cluster headaches, and migraine headaches (U.S. Department of Health and Human Services, 2014). Secondary headaches, on the other hand, are headaches that are caused by something else (U.S. Department of Health and Human Services, 2014). Examples of secondary headaches include headaches from an illness, headaches from a medication, sinus headaches, cervicogenic headaches (which are headaches related to an underlying neck condition, like degenerative disc disease), and headache due to a brain tumor or aneurysm (U.S. Department of Health and Human Services, 2014). Migraine headaches are one of the most common forms of headache (Davanzo, Bua, Paloni, Facchina, 2014). Migraines are considered a neurological condition (Schwedt, 2014; Silberstein, 2014). They often manifest as recurrent attacks of throbbing, frequently unilateral headaches with associated features, including: nausea, vomiting, photophobia, and phonophobia (Pietrobon Moskowitz, 2012; Schwedt, 2014). Migraines can be further subdivided into episodic or chronic (Schwedt, 2014). Episodic migraine sufferers have less than 15 headache days a month, whereas chronic sufferers have at least 15 headache days a month for at least three months, and at least eight headaches that have symptoms consistent with a full-blown migraine attack (Ferrari, 2013; Schwedt, 2014). Chronic migraine is a common disorder; it impacts people during their most productive years of life, has tremendous costs to the individual and society, and is associated with a variety of comorbid disorders (Schwedt, 2014). Chronic migraine typically develop through a process called migraine transformation, which is a slow increase in the frequency of headaches, usually over a period of months to years (Schwedt, 2014). Chronic migraine is diagnosed based on the patient’s symptoms by excluding other causes of headache (Schwedt, 2014). A general physical and neurological exam should be performed on each patient and attention should be paid to the patient’s neck, shoulders, temporal artery pulses, and tempromandibular joint; if any abnormalities are found on the neurological exam, a secondary headache should be suspected and the patient should undergo further evaluation (Schwedt, 2014). Many risk factors are associated with a higher likelihood of transformation from episo dic to chronic migraine and include obesity, excessive caffeine intake, low socioeconomic status, and major life changes like marriage or divorce, to name a few (Schwedt, 2014). Common conditions comorbid with chronic migraine include other neurological disorders, gastrointestinal problems, and cerebrovascular disease (Pietrobon Moskowitz, 2012; Schwedt, 2014). Compared to people with episodic migraines, patients with chronic migraine are twice as likely to have certain psychiatric disorders, including anxiety, depression, and bipolar disorder (Schwedt, 2014). The pathophysiology of chronic migraine is complicated and not fully understood (Schwedt, 2014). It was once believed that migraines were simply a swelling of the blood vessels in the brain (Pietrobon Moskowitz, 2012). More recent experiments have shown that swelling of the meninges and/or extracranial arteries is neither necessary nor sufficient to cause migraine pain (Pietrobon Moskowitz, 2012). While such swelling is certainly often found during migraines, migraines are no longer assumed to be exclusively a disorder of blood vessels; rather, there are data to suggest that chronic migraine is associated with progressive brain changes, both in brain structure and brain function (Ferrari, 2013; Pietrobon Moskowitz, 2012). Atypical modulation of pain is suspected to play a role in the transformation from episodic to chronic migraine by reducing the inhibition of pain in the regions of the descending pain modulatory pathway in the brain (Schwedt, 2014). Neuroimaging studies of patie nts with chronic migraine have shown both atypical structures of pain processing and atypical pain processing in the brain (Schwedt, 2014). Regions of the brain that participate in sensory discrimination, affect, and the cognitive appraisal of pain are also atypical in migraine sufferers (Schwedt, 2014; Silberstein, 2014). Many studies have found correlations among the extent of these abnormalities and the frequency and severity of migraine headaches, suggesting that these abnormalities could be precursor to the transformation from episodic to chronic migraine (Schwedt, 2014), but more research is necessary to determine the exact role and mechanism of these abnormalities. The trigemininovasular system is currently considered one of the major players in the role of chornic migraine (Pietrobon Moskowitz, 2012; Schwedt, 2014). The trigeminal nerve is the fifth cranial nerve in the body and is the main sensory nerve in the head (Fix Brueckner, 2009). Some researchers believe that the musculature around the trigeminal nerve branches become irritated, which leads to the swelling and pain caused by migraine headaches (Kurlander, Punjabi, Liu, Sattar, Guyuon, 2013). Presently it is speculated that a sensitization of the trigeminal system that innervates cranial tissues, specifically the meninges (which often swell during migraine attacks) leads to a lower threshold for activation (Pietrobon Moskowitz, 2012; Schwedt, 2014). A lower threshold for activation means the system becomes activated more easily, which leads to more migraine attacks, and more migraine attacks therefore increase the likelihood of a chronic migraine diagnosis (Pietrobon Moskowitz, 20 12; Schwedt, 2014). Another line of research that is currently being investigated is cortical hyperexcitability (Schwedt, 2014). The human nervous system is composed of billions of synapses and neurons functioning as part of a large, highly specializes system (Fix Brueckner, 2009). All aspects of behavior are informed by the nervous system, and it can rudimentarily be broken down into excitatory and inhibitory components that facilitate the communication among different neurotransmitters in the brain to determine the level of inhibition of excitation of each response (Fix Brueckner, 2009). Excitation in the brain is mainly associated with the neurotransmitter glutamate (Fix Brueckner, 2009). Recent transcranial magnetic stimulation studies on patients with chronic migraine have shown cortical hyperexcitability, particularly in the occipital cortex of the brain. The occipital cortex is associated with vision, and this makes sense to researchers as visual auras are often associated with migraine attack s (Fix Brueckner, 2009; Schwedt, 2014). A neurotransmitter of interest, particularly with the beginning phase of a migraine attack, is dopamine (Charles, 2012). Some research has shown that dopamine receptor agonists administered to patients produce some of the same symptoms that are experienced by migraine sufferers at the beginning of an attack (Charles, 2012). Conversely, dopamine receptor antagonists administered to patients can reverse those symptoms and have even been suggested to have the ability to prevent the onset of additional migraine attacks (Charles, 2012). While the exact role of dopamine in chronic migraine is unknown, it is certainly an interesting line of future study. Treatments for chronic migraine range from trigger identification and avoidance to risk-factor modification, and include both pharmacological and nonpharmacological components (Schwedt, 2014). A discussion of each type of treatment and the variety of treatments within is beyond the scope of this review, however, some of the most common pharmacological treatments will be highlighted. Pharmacological treatment for migraines can be divided into two categories: abortive drugs, which stop a headache after onset, and prophylactic drugs, which are taken on a regular basis to prevent the onset of a migraine (Davanzo et al., 2014). Those who suffer from chronic migraine are often on a prophylactic regimen, due to the intensity and severity of the headaches (Davanzo et al., 2014). While many drugs are used for chronic migraine prophylaxis, it is important to note that many are prescribed off label; in fact, the only drug approved by the Food and Drug Administration for the treatment of chronic migraine is onabotulinumtoxinA (Schwedt, 2014). OnabotulinumtoxinA, more commonly known as Botox, has been popularized as a series of small injections in the face that reduce the appearance of crow’s feet and frown lines (Oliver, MacDonald, Rajwani, 2006). However, the injections are also used to treat chronic migraine (Schwedt, 2014). Botox is part of a class of medications called neurotoxins (Fix Brueckner, 2009). It has no direct effect on the central nervous system because it cannot penetrate the blood brain barrier, however, it can have some important indirect effects on the central nervous system (Fix Brueckner, 2009; Oliver, MacDonald, Rajwani, 2006). When used to treat chronic migraine, Botox is injected into different muscles in the face to block the nerve signals to those muscles (Fix Brueckner, 2009; Oliver, MacDonald, Rajwani, 2006). Specifically, Botox has been shown to inhibit sensitizations of central trigeminal nerves, which was previously discussed regarding the pathophysiology of chronic migraine (Ol iver, MacDonald, Rajwani, 2006). Triptans are another common class of drugs used for chronic migraine prophylaxis (Davanzo et al., 2014). Triptans are serotonin receptor agonists, meaning they bind to serotonin and increase the response of serotonin at the site of action (Davanzo et al., 2014; Fix Brueckner, 2009). Triptans have a vasoconstriction action on blood vessels, meaning they shrink the size of blood vessels, which is helpful in reducing the pain of migraines some of which can be attributed to swollen blood vessels in the brain (Davanzo et al., 2014). However, the desired effect of vasoconstriction is not limited to just the brain and also constricts other blood vessels, including those in the heart (Davanzo et al., 2014). As a result, patients with any coronary disease should use care when taking triptans (Davanzo et al., 2014). The most commonly prescribed triptan medication is Sumatriptan and is available in multiple forms including pills, injections, and intranasal spray (Davanzo et al., 2014). The inj ections and intranasal spray reach the brain more quickly and are therefore faster acting than the pill which must first get absorbed into the blood stream to take effect (Davanzo et al., 2014). Beta blockers, originally used for the treatment of hypertension and angina, are also often used for migraine prophylaxis (Davanzo et al., 2014). The beta part of beta blockers refers to receptors on blood vessels that are called beta receptors (Fix Brueckner, 2009). Therefore, beta blockers prevent the interaction of certain chemicals with this receptor (Fix Brueckner, 2009). The most commonly prescribed beta blocker for chronic migraine is Propranolol (Davanzo et al., 2014). Propranolol is likely successful in preventing migraine headaches by blocking beta adrenergic receptors, which inhibits swelling of arteries. Additionally, Propranolol may also exhibit its effect by preventing the platelets (the sticky elements of the blood) from sticking together and releasing substances that caused the blood vessels to constrict and dilate. A concern with pharmacological treatment of chronic migraine is the development of medication overuse headaches. These occur when a migraine sufferer uses migraine drugs too frequently, and develops a secondary headache as a result of the medication use (Schwedt, 2014). The treatment includes a drug withdrawal phase, during which time the patient would have to stop taking medication for his migraine or take a medication with different mechanism of action to allow the overused drug to leave his system (Schwedt, 2014). This response is paradoxical because sufferers of chronic migraine often rely on pharmacological treatments to alleviate their pain, but if they take too much they will actually end up exacerbating their pain. About half of chronic migraine sufferers are treated for medication overuse headaches at some point (Schwedt, 2014). A brief overview of the criteria for diagnosis, hypothesized pathophysiology, and pharmacology for the treatment of chronic migraine has been discussed. While there is still much to learn about the pathophysiology of chronic migraine, recent research has increased the understanding and opened up new areas of research to bring scientists closer to a more comprehensive understanding. While many data indicate that chronic migraine is a debilitating condition with great intensity and duration of headaches, and often lead to lost productivity and high costs on society (Schwedt, 2014), there are prophylactic and abortive drugs that can greatly ameliorate the problems caused by migraines. With attention to and modification of risk factors, often in addition to appropriate adherence to these medications, migraine sufferers can live normal, productive lives.

The History Of The Airship :: essays research papers

The History of The Airship Airships. In the early years of War, these beasts were known for their majestic presence in the sky and were icons of a country's power and prestige. They reigned mostly as reconnaissance and transport utility aircraft but there was something about this "lighter-than-air" ship that made it far more than a mere utility workhorse. In this essay, I will discuss the ever-popular and ever- living king of the sky; the Airship. Airships, or dirigibles, were developed from the free balloon. Three classes of airships are recognized: the non-rigid, commonly called blimp, in which the form of the bag is maintained by pressure of the gas; the semi-rigid airship, in which, to maintain the form, gas pressure acts in conjunction with a longitudinal keel; and the rigid airship, or zeppelin, in which the form is determined by a rigid structure. Technically all three classes may be called dirigible (Latin dirigere, "to direct, to steer") balloons. Equipped with a bag containing a gas such as helium or hydrogen which is elongated or streamlined to enable easy passage through the air, these Airships could reach speeds up to 10mph with a 5hp steam engine propeller. The first successful airship was that of the French engineer and inventor Henri Giffard, who constructed in 1852 a cigar-shaped, non-rigid gas bag 44 m (143 ft) long, driven by a screw propeller rotated by a 2.2-kw (3-hp) steam engine. He flew over Paris at a speed of about 10 km/hr (about 6 mph). Giffard's airship could be steered only in calm or nearly calm weather. The first airship to demonstrate its ability to return to its starting place in a light wind was the La France, developed in 1884 by the French inventors Charles Renard and Arthur Krebs. It was driven by an electrically rotated propeller. The Brazilian aeronaut Alberto Santos-Dumont developed a series of 14 airships in France. In his No. 6, in 1901, he circled the Eiffel Tower. Count Ferdinand von Zeppelin, the German inventor, completed his first airship in 1900; this ship had a rigid frame and served as the prototype of many subsequent models. The first zeppelin airship consisted of a row of 17 gas cells individually covered in rubberized cloth; the whole was confined in a cylindrical framework covered with smooth-surfaced cotton cloth. It was about 128 m (about 420 ft) long and 12 m (38 ft) in diameter; the hydrogen-gas capacity totaled 1,129,842 liters (399,000 cu ft). The ship was steered by forward and aft rudders and was driven by two 11-kw (15-hp) Daimler internal- combustion engines, each rotating two propellers.