Amiri Baraka (LeRoi Jones) Essay Example | Topics and Well Written Essays - 500 words

Amiri Baraka (LeRoi Jones) - Essay Example Even after retirement, he remained active and productive. The assassination of Malcolm X became the turning point of his life where he changed his name to Amiri Baraka and dissolved his marriage to Hettie Cohen. He became a leader of Newark’s African-American community. Amiri Baraka was well known for his writing. He used his popularity as a way of defending the weak from social injustices (Koolish, 2001). Through poems, plays, fiction, and essays, he showed his leadership by condemning oppression and racial injustice of the African American community in the United States (Epstein, 2006). Through his works and words, Baraka was able to he was able to promote drama created by African American playwrights and performed for the African American audience that showed African American issues (Baraka, 1995). For example, his two plays The Toilet and The Slave which were both written in the year 1962 showed his mistrust and hostility towards the white society. His award winning production, Dutchman, showed the damage that America inflicts on African men (Baraka, 2000). In 1960s racial discrimination against African Americans was still high. Many black leaders started to rethink their goals, while dome embraced more militant ideologies of self-defense and separatism (Lie, 2006). The struggle for civil rights was high aimed at drawing the attention of the nation to the brutality and injustice that African Americans faced. Even though the economic situation was good in the country, many blacks lived under poverty which was evident in many black urban neighborhoods. Leadership is the ability of a person to lead a group of people or a team to achieve specific task (Northouse, 2012). After studying Amiri Baraka, it is clear that leadership is an in built quality. It can also be attained through an individual’s experience which inspires the leader (OSullivan, 2009). Leadership cannot be learnt by simply reading about it but it is something that someone gets

A Growing “Threat” to Society Essay Example for Free

A Growing â€Å"Threat† to Society Essay The Internet is one of the most powerful sources of information today. Thus, it has the capacity to enlighten, as well as to mislead. This double-edged potential has turned the Internet into the latest avenue for terrorism. Terrorists are now harnessing the power of the Internet to wreak havoc among the public (Conway, 2002). Terrorists use the Internet mainly as a propaganda tool – it is a venue wherein they publicize their cause or explain their ideological justification without misinterpretation or censorship. As of 2002, a majority of the 33 groups deemed foreign terrorist organizations by the United States State Department had their own web sites. There are also many other websites, that, despite not being related to any terrorist group, provide information on how to commit terrorist activities such as bomb-making. The latter often escape criminal prosecution due to the First Amendment, which guarantees freedom of speech to the general populace (Conway, 2002). The very idea of cyber-terrorism, however, is not without contention. For one, it is still not clear as to what differentiates cyber-terrorism from freedom of expression. Also, there are certain Internet-related crimes that cannot be considered as cyber-terrorism, although they inflict damage upon the public. Indeed, terrorism in itself is already a notoriously difficult concept to define. The addition of computers to it further complicates the idea (Conway, 2002). The Internet: A New Weapon The Internet was originally intended as a means of resuming contact in the event of a nuclear attack. But due to its speed and convenience, it is currently a major venue for information, communication and commerce. As of September 2006, there were more than 1 billion Internet users worldwide (Vatis, 2006). With just one click of a mouse, an entrepreneur in Germany can deposit funds to a bank account in Switzerland and talk to a London-based cousin face to face through a web camera. A student in California, meanwhile, can learn everything about the Great Wall of China with merely a few keystrokes. After 9/11 It was only after 9/11 that the very concept of cyber-terrorism was actually developed. Before 9/11, Internet-related crimes were usually in the form of sending pornographic email to minors, defacing web pages, stealing credit card information and launching computer viruses (Conway, 2002). After 9/11, however, US officials realized that terrorist organizations could use the Internet to generate more bloodshed (Weimann, 2004). Al-Qaeda, for instance, could launch missiles or biological weapons to the US by simply pressing the â€Å"Enter† button of a laptop (Stohl, 2006). To a certain extent, the fears of the US were well-founded. In November 2000, an electronic attack was carried out from Pakistan against the Washington-based pro-Israeli lobbying group American Israel Public Affairs Committee (AIPAC). Aside from defacing AIPAC’s site with anti-Israeli commentaries, the attacker likewise stole some 3,500 email addresses and 700 credit card numbers, sent anti-Israeli diatribes to the addresses and published the credit card data on the Internet. The Pakistani hacker, known by the alias â€Å"Dr. Nuker,† claimed responsibility for the incident. It turned out that â€Å"Dr. Hacker† was a founder of the Pakistani Hackerz Club, an organization whose objective was to â€Å"hack for the injustice going around the globe, especially with (sic) Muslims† (Conway, 2002). The aforementioned cyber assault was not without precedent. The Lebanese Shiite Islamic group Hezbollah established its collection of web sites in 1995. At present, the group has three websites that can be viewed in either English or Arabic – one for its press office, another to describe its attacks on Israeli targets (http://www. moqawama. tv) and a third, Al-Manar TV, for news and information (http://www. manartv. com). These websites regularly provide the latest information about Hezbollah, including press statements, political declarations, photos, video and audio clips. An email address is also provided as contact information (Conway, 2002). After 9/11, as a result, federal agents issued subpoenas and search warrants to almost every major Internet-based company, including America Online, MSN, Yahoo! and Google. In addition, many web sites were subjected to official closure by the Federal Bureau of Investigation (FBI). Included among those that were closed down were radical Internet radio shows such as â€Å"IRA Radio,† â€Å"Al Lewis Live† and â€Å"Our Americas. † The â€Å"jihad web ring,† a collection of 55 jihad-related websites, lost dozens of its sites due to pullouts by Yahoo! Lycos Europe, meanwhile, created a 20-person team to filter its websites for illegal activity and terrorist-related content (Conway, 2002). Cyber-terrorism: Is There Really Such Thing? One of the most common arguments against cyber-terrorism is that it is an imaginary threat (Lacey, 2007). Contrary to popular perception, there is a minimal chance that cyber-terrorists would exact harm on innocent people by attacking corporate and governmental computer networks. As of this moment, terrorist organizations use the Internet only for fundraising, communications and propaganda. There is the possibility that terrorists might use computers as weaponry to a significant degree, but this will â€Å"probably happen in the (distant) future† (Conway, 2002). At present, terrorists would draw more attention to their cause by setting off bombs instead of hacking bytes (Conway, 2002). Instead of getting extremely paranoid about cyber-terrorism, the government should instead focus on eliminating cyber attacks against companies. As of July 2002, hackers had successfully launched at least 180,000 Internet attacks against more than 400 public, private, governmental and non-profit organizations. The brunt of these attacks fell on the power and energy industries, as well as on the technology and financial services. If left unchecked, these cyber attacks would be very detrimental to consumers – in order to make up for their losses to hackers, owners of the above-mentioned industries will have to raise the prices of their products and services (Fishman, Jospehberg, Linn, Pollack, Victoriano, 2002). Conclusion Paranoia over cyber-terrorism is very dangerous. Aside from diverting attention from more serious crimes such as cyber attacks, it violates civil rights and liberties. Under the guise of â€Å"fighting terrorism,† even websites whose only crime was to express radical ideas were closed down. While it is the duty of the state to safeguard its constituents from danger, doing so should not infringe their inalienable rights. It is true that terrorism might turn to cyberspace in the future in order to spread even more fear and bloodshed. But before the government rushes out to eliminate â€Å"cyber-terrorists,† it must first have a clear-cut concept of what constitutes cyber-terrorism and what makes a cyber-terrorist. Otherwise, the government will end up worse than the terrorists that it aims to get rid of. References Conway, M. (2002). What is Cyberterrorism? Current History, 101, 436-442. Retrieved October 17, 2008 from Academic Research Library. Fishman, R. M. , Josephberg, K. , Linn, J. , Pollack, J. , Victoriano, J. (2002). Threat of International Cyberterrorism on the Rise. Intellectual Property Technology Law Journal, 14, 23. Retrieved October 17, 2008, from ABI/INFORM Global. Lacey, D. ComputerWeekly. com. (2007, April 29). How Real is the Threat of Cyber Terrorism? Retrieved October 17, 2008, from http://www. computerweekly. com/blogs/david_lacey/2007/04/ how_real_is_the_threat_of_cybe. html Stohl, M. (2006). Cyber Terrorism: A Clear and Present Danger, the Sum of All Fears, Breaking Point or Patriot Games? Crime Law Soc Change, 46, 223-238. Retrieved October 17, 2008 from SpringerLink. Vatis, M. (2006). The Next Battlefield: The Reality of Virtual Threats. Harvard International Review, 28, 56-61. Retrieved October 17, 2008 from ABI/INFORM Global. Weimann, G. United States Institute of Peace. (2004, December). Cyberterrorism: How Real Is the Threat? Retrieved October 17, 2008, from http://www. usip. org/pubs/specialreports/sr119. html#threat

Inotropes, Vasopressors and Vasodilators

Inotropes, Vasopressors and Vasodilators Suruchi Hasija, Jatin Narula ,Vandana Maravi. ADRENERGIC RECEPTORS AND SIGNALING PATHWAYS The main control over cardiac contractility is provided by the ÃŽ ²Ã¢â‚¬â€œadrenergic signaling pathways and that over the vascular tone by both ÃŽ ±- and ÃŽ ²Ã¢â‚¬â€œadrenergic pathways. The ÃŽ ± and ÃŽ ² receptors are stimulated by catecholamines circulating in the bloodstream and those released locally from the adrenergic nerve endings. The two main subtypes of ÃŽ ²Ã¢â‚¬â€œadrenergic receptors (ÃŽ ²Ã¢â‚¬â€œARs) in the cardiovascular system are the ÃŽ ²1 and ÃŽ ²2 subtypes. Myocardial ÃŽ ²1 and ÃŽ ²2-AR stimulation leads to increased contractility, whereas vascular ÃŽ ²2-AR stimulation induces vascular smooth muscle relaxation. Drug binding to myocardial ÃŽ ²Ã¢â‚¬â€œARs activates stimulatory G protein. This leads to activation of the enzyme adenylate cyclase that catalyzes the conversion of ATP to cAMP. A cascade of intracellular reactions finally leads to the physiological effect of increased myocardial contraction or vasodilation. The ÃŽ ±Ã¢â‚¬â€œadrenergic receptors (ÃŽ ±Ã¢â‚¬â€œARs) are further classified as ÃŽ ±1 and ÃŽ ±2 subtypes. ÃŽ ±1-AR on vascular smooth muscles are the main mediators of vasoconstriction. ÃŽ ±2-AR on the neurons function in a negative feedback loop to control ÃŽ ±-adrenergic vasoconstriction. Stimulation of ÃŽ ±1-AR coupled to G protein activates phospholipase C which in turn raises intracellular Ca+2. Stimulation of ÃŽ ±2-AR coupled to inhibitory G protein inhibits adenylate cyclase, thereby lowering intracellular Ca+2. INOTROPES Inotropy or contractility is the intrinsic property of the cardiac myofibril. It defines the amount of work that the heart can perform at a given load. Contractility is primarily determined by the availability of intracellular calcium. Depolarization of the cardiac myofibril leads to the entry of a small amount of Ca+2 into the cell which triggers the release of additional Ca+2 from intracellular storage sites (sarcoplasmic reticulum). The binding of Ca+2 to troponin, displacement of tropomyosin from the binding site on actin and formation of actin-myosin crossbridges eventually leads to contraction of the myofibril. All inotropic agents act by increasing intracellular calcium. Catecholamines, phosphodiesterase inhibitors and calcium sensitizers are the broad classes of available inotropic agents. Catecholamines Catecholamines comprise the major type of available inotropic agents. Their chemical structure includes a catechol ring, catechol hydroxyl groups and variable side chains. Endogenous(present naturally in the body) catecholamines include epinephrine, norepinephrine and dopamine, and synthetic catecholamines include isoprenaline, dobutamine, dopexamine and fenoldopam. Besides acting directly on adrenergic receptors, some catecholamines may act indirectly by releasing or inhibiting reuptake of norepinephrine at the nerve terminal or by metabolism to form norepinephrine. Table 1: Site and mechanism of action of sympathomimetics Table 2: Haemodynamic effects of catecholamines and phosphodiesterase inhibitors CO=cardiac output, dp/dt=force of myocardial contraction(change in pressure/time), HR=heart rate, SVR=systemic vascular resistance, PVR=pulmonary vascular resistance, PCWP=pulmonary capillary wedge pressure, MVO2=myocardial oxygen consumption Modified from Lehmann A, Boldt J: New pharmacologic approaches for the perioperative treatment of ischemic cardiogenic shock. J Cardiothorac Vasc Anesth 19:97-108, 2005. Epinephrine Epinephrine, a naturally occurring catecholamine, is secreted from the adrenal medulla. The effects on ÃŽ ²Ã¢â‚¬â€œARs predominate at lower doses and on ÃŽ ±Ã¢â‚¬â€œARs at higher doses (> 0.1  µg/kg/min). It increases heart rate (HR), stroke volume (SV) and coronary blood flow (CBF). The rise in blood pressure (BP) results from increase in HR and cardiac output (CO). Systemic vascular resistance (SVR) decreases at low doses (ÃŽ ²2-AR effect) but increases at high doses (ÃŽ ± effect). It is metabolized in the liver by the enzymes catechol-O-methyl transferase (COMT) and monoamine oxidase (MAO), and the metabolites are excreted in urine. It has arrhythmogenic potential. In cardiac surgical patients it is used as an infusion at 0.01-0.4  µg/kg/min to wean patients with poor ventricular function off cardiopulmonary bypass (CPB). (Tables 1 and 2) Norepinephrine Norepinephrine is the postganglionic neurotransmitter in the sympathetic nervous system. It acts on ÃŽ ±1–AR, ÃŽ ±2–AR and ÃŽ ²1–AR, and has negligible action on ÃŽ ²2–AR. The ÃŽ ²1-AR action predominates at lower doses, thereby increasing inotropy, SV and CBF. It increases BP and SVR; but decreases HR. The CO remains unchanged. It has arrhythmogenic potential. The clinical dose range is 0.01 to 0.1  µg/kg/min. Like epinephrine, it is easily oxidized. It is metabolized by COMT and MAO and taken up by the sympathetic neurons. It decreases renal, hepatic, mesenteric and splanchnic blood flow. Dopamine Dopamine is a neurotransmitter in the central and peripheral nervous system. It is the immediate metabolic precursor of norepinephrine and epinephrine. It acts on ÃŽ ±Ã¢â‚¬â€œARs, ÃŽ ²Ã¢â‚¬â€œARs and dopaminergic receptors (DA1-DA5). At 0.5-3  µg/kg/min it increases renal and mesenteric blood flow (dopaminergic effects), between 3-8  µg/kg/min it increases HR and contractility (ÃŽ ²-AR effects) and, above 8  µg/kg/min it causes vasoconstriction (ÃŽ ±-AR effects). Intravenous dopamine does not cross the blood brain barrier. It is metabolized in the liver by COMT and MAO. Isoprenaline Isoprenaline has pure ÃŽ ²Ã¢â‚¬â€œAR agonist activity. It causes an increase in HR and contractility (ÃŽ ²1-AR effect) and decreases SVR (ÃŽ ²2-AR effect). CO increases due to combined ÃŽ ²1 and ÃŽ ²2-AR effect. It dilates pulmonary, skeletal, renal and mesenteric vascular beds. It is indicated in the treatment of pulmonary hypertension, bradycardia (especially after orthotopic heart transplantation), heart block and conduction abnormalities. It is used in the dose 0.01 to 0.1  µg/kg/min. it is metabolized in the liver by COMT. It is arrhythmogenic. Dobutamine Dobutamine is primarily a ÃŽ ²1-AR agonist and has positive inotropic effects. It causes modest increase in HR (ÃŽ ²2-AR effect) and decrease in SVR (ÃŽ ²2-AR effect). The clinical dose range varies from 2-15  µg/kg/min. It is particularly indicated in patients with myocardial pump failure. Its chemical structure lacks the hydroxyl group of catecholamines. It is metabolized in the liver, although not by COMT and MAO. It increases SV, CO and CBF. The arrhythmogenic potential is less than other catecholamines. Dopexamine Dopexamine is a synthetic analog of dopamine. It has potent ÃŽ ²2-AR and dopamine agonist properties and little ÃŽ ²1-AR and ÃŽ ±-AR activity. It causes vasodilation, increase in HR and inotropy. CO and renal blood flow are increased. It is used in the dose 1-10  µg/kg/min. It undergoes methylation and sulfation in the liver and is taken up into the tissues via extraneuronal catecholamine uptake mechanisms. Unlike other catecholamines, it lacks arrhythmogenic potential. Fenoldopam Fenoldopam mesylate is a dopamine DA1 receptor agonist that causes systemic and renal arteriolar vasodilation. It increases renal blood flow at doses of 0.05-0.1  µg/kg/min and reduces BP at 0.1-0.3  µg/kg/min. Phosphodiesterase inhibitors Phosphodiesterase inhibitors act by preventing the breakdown of cAMP, thereby prolonging its physiological response. They do not act via ÃŽ ²-AR stimulation. Their addition to a catecholamine has a synergistic effect in increasing inotropy. They also produce vasodilation and are termed ‘inodilators’. They improve myocardial diastolic relaxation (positive lusitropic effect) and augment coronary perfusion. The clinically used phosphodiesterase inhibitors include amrinone, milrinone and enoximone. Amrinone Amrinone is a bipyridine derivative. It provides positive inotropy and decreases SVR. The decrease in SVR is apparent immediately after administration, whereas positive inotropy is appreciable after 10-15 minutes. They are particularly useful in heart failure by increasing forward flow. It is administered as a bolus loading dose (0.5-1.5 mg/kg) followed by infusion (5-20  µg/kg/min). The potential side effects are thrombocytopenia (2-3%), gastrointestinal upset, myalgia, fever, hepatic dysfunction, ventricular arrhythmias and allergy. Milrinone Milrinone is a derivative of amrinone and is 20 times more potent. It does not cause fever or thrombocytopenia. It is administered as a bolus loading dose (50  µg/kg over 10 minutes) followed by infusion (0.375-0.75  µg/kg/min). Enoximone Enoximone is an imidazole derivative that has more pronounced vasodilatory effect than inotropic effect. It is administered as a bolus loading dose (0.5-1 mg/kg) followed by infusion (5-10  µg/kg/min). Levosimendan Levosimendan is a new inotropic agent belonging to the class of calcium-sensitizing agents, i.e., it sensitizes the myocardium to the actions of calcium. It has vasodilating and anti-ischemic properties mediated by opening of K+-ATP channels. The haemodynamic effects include increase in SV and CO and reduction in filling pressures, mean arterial pressure (MAP), mean pulmonary artery pressure (MPAP) and SVR. It also promotes lusitropy. It is useful in patients with compromised left ventricular function, difficulty in weaning from CPB and right ventricular failure. It is used in a loading dose of 12  µg/kg over 10 minutes followed by an infusion of 0.1  µg/kg/min. Calcium chloride Calcium ions play an important role in excitation-contraction coupling in the cardiac myofibrils. It has positive inotropic effect that is effective after CPB and in the short-term treatment of myocardial pump failure. The rise in BP occurs secondary to increased inotropy and vasoconstriction. However, it can attenuate the ÃŽ ²-AR effects of epinephrine in the postoperative cardiac surgical patients. It is administered in the dose of 2-4 mg/kg every 10 minutes. Calcium Gluconate the clinically available compound of calcium ,contains less than half of ionized calcium and has to be metabolized in the liver before action. VASODILATORS Vasodilators cause relaxation of arterial smooth muscle thereby reducing SVR and MAP. In addition, they also have venodilating property. They aid discontinuation of CPB by decreasing preload, right and left ventricular afterload, improving lusitropy and CBF. They are useful in the perioperative treatment of systemic and pulmonary hypertension, myocardial ischemia and ventricular dysfunction complicated by excessive pressure or volume overload. Sodium nitroprusside Sodium nitroprusside (SNP) acts by acting as a substrate for the formation of nitric oxide (NO) in the vascular endothelium. Binding of NO to its receptor induces a conformational change in the enzyme guanylate cyclase and production of cGMP from GTP. cGMP is the second messenger that eventually leads to vascular smooth muscle relaxation via numerous intermediate steps. SNP predominantly causes arterial and arteriolar vasodilation, but at high doses venodilation also occurs. Reflex tachycardia is apparent with its administration. SV and CO are increased only if the preload is maintained with intravenous fluids. SNP has a potential to cause ‘coronary steal’ phenomenon in patients with coronary artery disease as the epicardial coronary arteries also dilate diverting blood away from the stenosed endocardial coronary arteries. It decreases pulmonary vascular resistance (PVR) and MPAP. It abolishes hypoxic pulmonary vasoconstriction and may contribute to hypoxia. The infusion rate is 0.5  µg/kg/min, and titrated to effect. It is reconstituted in a dextrose-containing solution. SNP is sensitive to light, therefore the infusion syringe and tubing are wrapped with opaque material to prevent light induced structural breakdown of the drug. Cyanide toxicity may occur with the use of SNP above 1.5 mg/kg acute dose or 8  µg/kg/min chronic infusion. SNP is used during hypothermic CPB to promote uniform cooling by preventing cold induced vasoconstriction, to reduce the perfusion pressure, to reduce afterload by decreasing SVR and to increase pulmonary blood flow by decreasing PVR. Nitroglycerin Nitroglycerin (NTG) acts by the same mechanism as other nitrates. NTG is primarily a venodilator and reduces ventricular preload and myocardial oxygen consumption. NTG is of particular importance in patients with congestive heart failure as it unloads the left ventricle. It has modest effects on SVR and BP. It reduces PVR. The starting dose of intravenous nitroglycerin is 0.5  µg/kg/min which may be titrated to effect. Attention must be paid to the fluid status as CO may drastically reduce. At higher doses systemic vascular dilation occurs. NTG is helpful in coronary artery disease because it causes epicardial coronary artery dilation. It is metabolized in the liver. Methemoglobinemia occurs at high infusion rates. Intravenous nitroglycerin has a half-life of 1-3 minutes. Tolerance develops when administered for more than 8 hours. Nitric oxide Nitric oxide (NO) is the endothelium derived relaxing factor. Its mechanism of action has been described above. It has a very short half-life of 5 seconds. Inhaled NO promotes pulmonary vascular dilation. It can be used upto 80 parts per million (ppm) in patients with severe right ventricular failure and pulmonary arterial hypertension. As inhaled NO is rapidly taken up by the heme group of guanylate cyclase, it only acts locally in the pulmonary vascular bed causing pulmonary vasodilation. It has no systemic effects. Phenoxybenzamine Phenoxybenzamine is a non-competitive ÃŽ ±1 and ÃŽ ±2-AR blocker. It decreases PVR and SVR, thereby increasing CO. It is used to promote vasodilation during deep hypothermic circulatory arrest for uniform cooling and for the treatment of pulmonary hypertension. Phenoxybenzamine is a very potent and long acting vasodilator. It was traditionally used for afterload reduction, pulmonary vasodilatation, and in adrenal tumors such as pheochromocytoma. Phentolamine, a shorter acting agent is now more commonly used. VASOPRESSORS Vasopressors act on arteries and arterioles to increase SVR (ÃŽ ±-AR effect). They have some ÃŽ ² –AR effect also. Catecholamines such as norepinephrine, and epinephrine and dopamine at high concentrations are potent vasoconstrictors. In addition, sympathomimetics such as phenylephrine, methoxamine, ephedrine, metaraminol and mephentermine are also vasoconstrictors. They are metabolized by COMT and MAO. Phenylephrine Phenylephrine is a pure ÃŽ ±1-AR agonist and its primary action is to increase SVR. Reflex bradycardia may be seen. Vasoconstriction of renal, splanchnic and other vascular beds occurs. Coronary perfusion pressure is increased due to increase in diastolic pressure. The intravenous bolus dose is 50-100  µg and infusion rate is 0.5-1.0  µg/kg/min. Its effect is apparent in 1 minute and lasts upto 20 minutes. It is commonly used to increase SVR and therefore the perfusion pressure on CPB. Mephentermine Mephentermine has direct action on ÃŽ ±-AR and ÃŽ ²-AR, and indirect action by releasing norepinephrine at the nerve terminal. It increases CO and SVR. Its acts immediately on intravenous injection and it’s action lasts 30 minutes. It is used in 15-45 mg bolus doses and as 0.1% infusion titrated to effect. Vasopressin Vasopressin,a hormone of the anterior pituitary is a potent vasoconstrictor. It mediates vasoconstriction by inhibiting K+ ATP channels on vascular smooth muscles and blunting the rise in cGMP (due to NO and ANP) and cAMP (due to ÃŽ ²2-AR stimulation). It is one of the modalities of treating vasodilatory shock after CPB. It is used in the infusion dose of 0.01-0.1 U/min for this purpose. At higher doses it has the potential to cause renal and splanchnic vasoconstriction. It is also administered as a bolus dose of 40 U i.v. during cardiopulmonary resuscitation. Suggested reading Hoffman TM. Newerinotropesin pediatric heart failure. J Cardiovasc Pharmacol. 2011 Aug;58(2):121-5 Rognoni A, Lupi A, Lazzero M, Bongo AS, Rognoni G. Levosimendan: from basic science to clinical trials. Recent Pat Cardiovasc Drug Discov. 2011 Jan;6(1):9-15. Tavares M, Rezlan E, Vostroknoutova I, Khouadja H, Mebazaa A. New pharmacologic therapies for acute heart failure. Crit Care Med. 2008 Jan;36(1 Suppl):S112-20. Petersen JW, Felker GM. Inotropesin the management of acute heart failure. Crit Care Med. 2008 Jan;36(1 Suppl):S106-11 Ward RM, Lugo RA Cardiovascular drugs for the newborn.Clin Perinatol. 2005 Dec;32(4):979-97 Hug CC Jr. Making a choice ofinotropesandvasodilatorsin clinical situations.J Card Surg. 1990 Sep;5(3 Suppl):272-7 Stanford GG. Use of inotropicagentsin critical illness. Surg Clin North Am. 1991 Aug; 71(4):683-98.

Impact of Prison on Fyodor Dostoevskys Poor Folk, The Double, and The Idiot :: Dostoevsky Poor Folk Essays

Impact of Prison on Fyodor Dostoevsky's Poor Folk, The Double, and The Idiot Fyodor Mikhailovich Dostoevsky is perhaps one of the most well known but least understood authors from the nineteenth century. His life was one full of misfortune and suffering; his works filled with religious pondering and philosophical discussions. Dostoevsky's life experiences were integrated into the characters in his pieces, both in terms of personality and ideology. An especially important turning point in his life was his arrest and imprisonment at the age of twenty-seven, shortly after the beginning of his writing career. This prison sentence and time in exile served to shape his perceptions and beliefs towards life, which were then incorporated into his literary works. Dostoevsky entered the Chief Engineering Academy in Saint Petersburg in 1838, at the age of 17. Upon his graduation, he served in the civil service, but gave it up to pursue writing full-time. 1846 saw the publishing of his first books, Poor Folk, and The Double. In Poor Folk, he explores some of the social issues of the day, and the work has even been dubbed of a "socialist character." During this time, he had joined forces with other young intellectuals, and began attending meetings headed by Petrashevsky. These young "social realists" would meet and discuss current political issues -- most importantly, the idea of the liberation of the serfs. This issue was especially of interest to Fyodor, who had been exposed to the cruelties of serfdom early in his life. He had a deep hatred of the institution of serfdom, which was perhaps rooted in his guilt towards the murder of his father. It was thought that Mikhail Andreevich was murdered by his own serfs during a particularly violent bout of anger towards them. Fyodor, while he was in no way associated with the death (he was in school in Saint Petersburg at the time), none the less felt guilt. Part of this may have been due to his incessant nagging for more money from his father during his last few years. This group of idealists was influenced by the changing political status in Europe during the middle of the nineteenth century. This was a time of a new social awareness -- new rights and liberties were being fought for and won, governments were transforming, and a series of "utopian socialist" books were quickly becoming popular. Dostoevsky had been an avid reader of such authors as Hugo, Sand, Sue, and others in this field.

Carmina Burana

A work that many have, at least heard a piece, of is Carmina Burana. Carl Orff composed this piece of music in 1936. A German, he was one of few composers that continued work during the Anti-Semitic rule of the country. Orff based his work off of a collection of poems found at the monastery of Benedikbeuren that dates back to the Twelfth Century! Carmina Burana is a set of twenty-five pieces that concern many of things going in everyone’s life today.Drinking, gambling, love, sex, fate, and fortune are just a few of the topics Orff composed of. 1 In this concert report I will go through the pieces that stood out the most to me. As mentioned, the most famous piece of this work is the opening sequence, â€Å"O Fortuna†. This glamorous piece begins with the full orchestra and chorus playing a loud, brave tone that quickly drops off into, what I hear as a loud whisper, sung by the entire chorus. Orff doesn’t let the listener take a break by coming back with same loud tone that the piece began with.Percussion instruments can be vividly heard throughout this opening piece, seemingly above the rest of the instruments. Early in this work, Orff establishes his theme of a â€Å"Wheel of Fortune†. 2 With the boldness of the opening sounds I feel that Orff is setting the tone for the whole work. Although the work is sung entirely in Latin, the translation of the first movement may surprise most people. The opening words â€Å"O Fortune† gives the listener an idea what the piece is about. As the piece goes, Orff describes fortune as oppressing and poor, in what I believe he was feeling at the time.The last words of this movement, in translation â€Å" everyone weep with me â€Å" were the biggest surprise to me because the orchestra ends the piece in carnival like melody. The second movement of Orff’s work is titled â€Å"Fortune plango vulneraâ€Å". This is personally my favorite piece of the work because of the hit or miss har mony. Different instruments take turns using the high-low rhythms, along with the chorus. The male voice is prominent at the beginning but soon after you can hear the voice of the full orchestra. Before reading the text n translation, this piece gave the idea of a rabbit jumping through to pasture or meadow to a novice listener like myself. This piece picks up from the last movement still pertaining to fortune. In the latter part of this piece Orff actually wrote in his overall theme by mentioning â€Å"the wheel of Fortune turns†. The fourth movement, â€Å"Omnia sol temperat† is sung in a completely different way. It begins with a male soloist singing, accompanied softly by violins. The way Orff chose to display this movement shows that there is no defined rhythm he is following.The soloist singing in a profound masculine voice sets the tone for this movement. The next movement discussed stands out as being one of the longest works of the cantata. â€Å"In taberna q uando sumus† opens with stringed instruments followed by percussion, and then a variety of other instruments join with the chorus. â€Å"When we are in the tavern†, the title sets this piece up for what I think would have a been a popular movement when it originated. Orff tells of drinking and gambling at the tavern, then goes on to list thirty names such as â€Å"the rich man† and â€Å"the poor man† that all drink.This stood out to me because I didn’t see this coming at all! It is also my least my favorite piece of the work. With the setting what it is, I didn’t particularly like the minor tone heard on and off in this movement. Orff could have been trying to relay a message by this of the tavern as a sometimes dark, bad place. The last movement of the cantata, â€Å"O Fortuna† begins just as the piece began with the same instruments and harmony. The last movement mirrors the first in a way that makes the listener understand the true tone of this work.I compliment Orff for doing this because I feel it is necessary. With a piece as strong and bold as this, I would think most composers would have chose to do this. After going back and re-listening to the first and last piece, there is no difference to my ear. The last movement does not lack any of the strength of the first movement; it’s a repeat that is well deserved. This theme has been used in many American movies, but sadly it is seldom recognized. Carl Orff made his mark in music history with Carmina Burana, namely the first and last movements â€Å"O Fortuna†.There are many more movements in this piece that all have uniqueness and glamour. Even though I am not the most avid Carl Orff fan, this piece surprised me with every movement. The overall performance of this piece was outstanding, with all the different melodies and tones, the use of full orchestra to solo vocalist, and an excellent job of conducting by Jeffery Thomas, I can see how this piece gained as much fame as it did. 1 â€Å" The Enjoyment of Music† Eleventh Edition, Kristine Forney and Joseph Machlis 2 http://classicalmusic. about. com/od/20thcenturymusic/a/carmina_burana. htm

Imaginations, Values, and Emotions

Imaginations, Values, and Emotions There are wide variations in regard to time periods and genres as far as art works are concerned. It is worth noting that some art works were founded on individuals’ minds or cultural and social influences.Advertising We will write a custom essay sample on Imaginations, Values, and Emotions specifically for you for only $16.05 $11/page Learn More In addition, other art works were as a result of an influence from the features and styles used during previous periods and were a reaction or continuation to the artistic styles. The link between the renaissance and neoclassical art eras will be examined. There will be an analysis and discussion of whether there was a reaction to or continuation between the two art periods. Renaissance, characteristics, and social conditions that led to the advent The word renaissance is a French term. It came up during the nineteenth century and elaborates the rebirth of a period that occurred between the fourteenth and sev enteenth century. The artists during this period emulated the works of art from artists before this period. In addition, they incorporated color and light via novel dimensions. During this period, there was innovation of the sense of space and perspective that allowed viewers to view in 3- dimensions. Art was fundamentally inspired by sacred and commissions motivations (Rachels Rachels, 2007). Some of the notorious artists during the renaissance art period included Raphael, Leornardo, and Michelangelo. The art works done during this period were elaborated in that they included more than the vanishing point, horizontal line, and linear perspective. The artists during the renaissance art period had a keen interest in the way light hit objects and consequently formed shadows (Rachels Rachels, 2007). The light and shadows played a great role in attracting viewers to particular areas on the object. The artists also wanted the viewer to get involved emotionally as he looked at the objec t and, therefore, get encouragement and faith. The artists also invested greatly in naturalism and realism. For instance, they wanted images of people to appear more realistic. The images were solid and showed real emotions. This made the viewer to start thinking about what the people were feeling or thinking. Neoclassical, characteristics, and social conditions that led to the advent Neoclassical art refers to a form of art that was exceptionally unemotional and severe. Its rigidity was closely associated with the Baraque and Rocco styles. It was as a result of the renewed interest arising from the classical period. This was greatly beneficial to a number of revolutions. Romanticism emerged in the 1800s as a reaction to neoclassicism and some of the famous artists during this period included Robert Adam, Bertel Thorvaldsen, and Anton Rapheal Mengs.Advertising Looking for essay on art and design? Let's see if we can help you! Get your first paper with 15% OFF Learn M ore The key characteristics of the art works during the neoclassical period included stern heroism, lack of emotions, and seriousness. The artists often used sombre colors and brilliant highlights that portrayed self- sacrifice and self- denial. The neoclassical period had distinct features of the structure and form used during the classical art period. In addition, there was clarity and realism (Rachels Rachels, 2007). It is worth noting that similar to the renaissance period that had connections to the social situations and political structure, the neoclassical period had a direct connection to the political events. Neoclassism was linked to the French Revolution beliefs. Similarities and differences between neoclassical and renaissance art periods Whereas the artists during the neoclassical period aimed at recreating the classical art period, which was the Romans’ and Greeks’ style, the renaissance period was basically a rebirth. During the renaissance peri od, people started considering science as a way of answering questions and receiving information. Previously, only religion was used. The neoclassicists were in search of a simple way of thinking that was not chaotic. Continuation of the previous historical art period During the neoclassical period, artists wanted to bring about advancements as was the case during the neoclassical period (Rachels Rachels, 2007). During the two periods, there were great advancements in visual arts, music, painting, and architecture. In addition, the fame associated with artists during the renaissance period continued during the neoclassical period as a result of the artistic philosophies and ideologies experienced. Specific works During the renaissance period, Michelangelo came up with a masterpiece referred to as David. In addition, the Psyche Revised by Cupid’s Kiss was created by Antonio Canova. The renaissance art was represented by David through an impression of the political scenario th at prevailed. On the other hand, the Psyche Revised by Cupid’s Kiss was a depiction of the artist’s concentration on the classical arts and Romans (Rachels Rachels, 2007). Relationship between the works The two works of art discussed reflect huge artistic developments. Irrespective of the fact that the two periods were a representation of great advancing periods as far as art was concerned, the artists and art purposed on extremely varying things. During the renaissance period, artists focused on the political systems, social situations, and culture. The art was created from the social conditions that contributed to the political system in Europe. Hence, it is evident that the link between neoclassical and renaissance cannot be underrated.Advertising We will write a custom essay sample on Imaginations, Values, and Emotions specifically for you for only $16.05 $11/page Learn More References Rachels, J. Rachels, S. (2007). The elements of mora l philosophy (5th ed.). New York: McGraw-Hill.

What is the effect of mass on friction Essay Example

What is the effect of mass on friction Essay Example What is the effect of mass on friction Essay What is the effect of mass on friction Essay To conduct this experiment, certain materials will be required. These include the following: 2 force meters (one that measures forces up to 5 Newtons and one that measures forces up to 10 Newtons), a mass i.e. a block of wood of about 15cm3, a table or any smooth surface, a strip of slightly grainy sandpaper and another strip of more grainy sandpaper. The experiment will be set up as shown below (fig 1).Fig 2This experiment was set up into two sections, firstly the effect of mass on dynamic friction and then the effect of mass on static friction.Dynamic Friction: For the dynamic friction experiment, the force of friction will be read off the force meter. This is due to Newtons second law stating that Fnet = ma. When the block is being pulled along at constant speed, the acceleration is 0 so Fnet = 0. Therefore P = F and so the force shown on the force meter is equal to the frictional force.A hook should first be placed into the block of wood so that it may be pulled along by the forc e meter. Then the block must be massed and its mass recorded (see table of results) along with its weight (for this experiment 100g = 1N). The mass is then placed onto the first surface and the force meter hooked onto it. Refer to the pilot test to know which force meter would be more suitable at this stage. The block is then pulled along the surface at constant speed and the reading on the force meter should be recorded in the table of results. Repeat this reading two or three times to increase its reliability and then calculate an average of all the readings. Remember to include the repeat readings and the average in your table of results. The experiment should then be set up again using the same block of wood and the same surface but by adding a mass onto the block thus increasing its weight. The new mass and weight of the block should also be recorded in the table of results. The block is then pulled along at constant speed by the force meter and its reading recorded along with the repeat readings. Repeat this about 7 times, each time adding an extra mass on ( the mass being added on should be the same each time).This whole procedure must then be repeated on each surface using the same block of wood, the same surfaces and materials and the same intervals of masses to ensure fair testing. For each experiment there should only be one variable that changes: the mass, all others should be controlled and kept constant.Static Friction: This experiment is set up in the exact same way, keeping the same variables and materials. This time, the block should not be pulled along the surface at constant speed but the force meter should be pulled gently until the block moves. The reading must be taken just as the block moves. This should be repeated as in the dynamic friction experiment and the same masses should be added. All readings should be recorded in a separate table.Now that the experiment is prepared, a pilot test can be carried out. In this pilot test the range of readings will be chosen along with which surfaces to choose from. Our range of masses was chosen to be from 0 1 kg with 8 readings on each of the three surfaces. A choice of five surfaces was offered and the three chosen were the ones that differentiated the most from each other. Very grainy sandpaper was supplied but during the pilot test it was found that as it the grains were so large, the lighter masses would just glide right over them.Friction is a force that tries to oppose motion. It is caused when two surfaces are in contact, by the roughness of the materials rubbing against each other, deformations in the materials, and a molecular attraction between materials. If looked through a microscope, friction on the molecular level is due to the unevenness of the surfaces. The two surfaces would have bumps, hills and valleys that would interfere with the sliding motion. If mass was to be added to these surfaces, the bumps and valleys would be pushed harder together, locking th em tighter together making it harder to move them. This means that as more masses are added onto the block, the reading on the force meter will go up proportionally. Therefore if we plot a graph of the force on the force meter over the weight, a straight line through the origin should be obtained.