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The Benefits Of Laptops And Wireless Cards :: Technology Computers Papers

The Benefits Of Laptops And Wireless Cards The CEO of Viacom/Blockbuster was once cited for saying, â€Å"The data superhighway is ...

Friday, November 29, 2019

The Major Conflict In The Novel, Cry The Beloved Country, Is An Inner

The major conflict in the novel, Cry the Beloved Country, is an inner uncertainty within the characters. The author, Alan Paton, shows this inner conflict from two perspectives; the Europeans and the Native South Africans. These two groups also have inconsistencies in their conscious to resolve. The black Natives are struggling between tradition and the new world. The Natives are forfeiting their old values as they progress towards the mode of the big city life. The Europeans are also confused. Many Europeans want to help the Natives, but are faced with following old tradition. Conventionally, these two groups should live independently. The changing of customs and values created apprehension and fear for both groups of people. Steven Kumalo, a Native priest, faced inner conflicts throughout the book. Kumalo had dreams of restoring the tribe and reuniting his family. He received a letter telling him his sister was ill in Johannesburg. Steven overcomes his fears of the big city and attempts to reunite his broken family. Steven hoped to find his sister Gertrude, brother John, and son Absalom. Each of these characters rejected their old values. His brother, John, was a corrupt politician. Kumalo's sister, Gertrude, was a prostitute. Absalom, Stephen's son, killed Arthur Jarvis. Kumalo struggled with feelings about his family members. He continued to encounter the clash of two different worlds affecting their lives. The Europeans were caught between tradition and the modernistic ways. The Europeans had been taught they were a superior race. Many Europeans doubted their traditional views and lifestyles. During the Native's bus boycott, a few Europeans voluntarily drove the Natives so they did not have to walk. The old routine customs were questioned, and challenged. In this case, the rules were ignored. Customs were also ignored during Absalom's trial. Absalom Kumalo, Stephen's son, was found guilty of murdering Arthur Jarvis. Absalom's white friend broke the color line while leaving the courtroom. Carmichael ran to help Stephen who was about to collapse from devastating grief for his son. Helping a friend, rather than obeying tradition was Carmichael's response to this inner conflict. Jarvis and Kumalo began interacting with each other when they returned to Natal. Mr. Jarvis's grandson visited Stephen's home a few times before returning to Johannesburg. Kumalo taught the young boy the Native Zulu language. The boy was a respectful and attentive student. Mr. Jarvis's grandson challenged the old ways and accepted his teacher. It was much easier for the younger generations to accept the challenges of change. The younger generations had different views about racial issues than their parents. Mr. Kumalo hoped the younger generations would prosper and live peacefully. James Jarvis and Stephen Kumalo returned to their homes in Natal. A deadly drought had devastated the land. Mr. Kumalo turned to tradition for an end to the drought. He visited the tribal chief for help. The chief told Kumalo there is nothing to be done and they will pray for rain. Stephen Kumalo and many others viewed the chief as just a figurehead. Kumalo's trip to Johannesburg taught him to accept new ways and ideas. Stephen Kumalo questioned traditional solutions to the current problems in his land. James Jarvis returned to help the Native tribal community. He hired a new teacher for the school. The teacher informed the Natives of new farming methods. The new knowledge helped the natives through the drought. Mr. Jarvis also gave the Natives milk for the young children until they could get enough of their own. He also offered to build Stephen a new church. Jarvis ignored belief and custom to help people in need, regardless of their skin color. Alan Paton's novel presents the personal conflict of Jarvis and Kumalo. Through their lives, the larger conflict between the races in South Africa and for all humanity is presented by this wonderful author.

Monday, November 25, 2019

Circular Motion Essays

Circular Motion Essays Circular Motion Paper Circular Motion Paper Circular motion is the motion that links velocity, mass, and radius of the string of an object. If any one of the factors is changed, the motion of the object gets affected or the velocity/acceleration gets affected. All objects going through circular motion experience a force called the centripetal force. Centripetal force is the force that acts from the center of the circular path and makes the object move in the curve instead of flying out. In other words, centripetal force is the force that originates from the center and is directed inwards. Also, one important factor in this lab is that the circular motion will be horizontal. In this experiment, the factor that will be changed is the radius of the string. This will bring in a direct change in the motion of the rubber stopper attached to the string. The string will pass through a plastic tube, which will be holding gear and the time for 10 rotations of the rubber stopper will be timed by a stop watch. The velocity will be calculated by using the universally known formula: v = (2r) / t , where v is the velocity, r is the radius of the string and t is the time for one rotation. The main purpose of this experiment is to find out one factor that affects the motion of a rubber stopper in circular motion. In this lab, this factor is the change in radius of the string that is attached to the rubber stopper. In this experiment, the factor that will be changed is the radius of the string. As the radius of the string decreases, the speed of the revolving rubber stopper increases. This would happen because as the radius decreases, the rubber stopper takes less time to circle around with the constant centripetal force on it. In other words as the radius decreases, the size of the circle decreases, hence it takes less time to cover a smaller circle, with the same force acting on the rubber stopper. In other words, the radius of the string is inversely proportional to the velocity of the stopper. Overall, the experiment was carried out with minimum errors and followed as the procedure. There were eight data points with three trials each. The experiment was related to one factor that affected the motion of the rubber stopper in circular motion. In this experiment, that factor was the length of the string (radius). As stated in the hypothesis, the radius was decreased which would increase the velocity of the stopper. But as it can be seen from the data table and graph that as the radius decreased the velocity also decreased. Hence, the radius of the string is directly proportional to the velocity of the stopper. This proves my hypothesis wrong which stated that as the radius decreases, the velocity increases. In my experiment, the radius was decreased which decreased the time elapsed but decreased the velocity as well. This would have happened because as the radius decreased, the stopper actually has to move faster in order to cover the larger circle in the same amount of time. The stopper actually covers much more area of the circle when the radius is larger without taking more time. This theory is exactly opposite as stated in my hypothesis. As it can be seen from my graph and the data table that there were some errors in my experiment. The percent error that was calculated to be 13. 5 % assures the fact that there were flaws in my experiment. One big error was that when the stopper was revolving, the hand often touched the string of the stopper. This often altered the centripetal force acting on the string, hence changing the values of my data. Another error was that not all the time the radius mark (the mark on the string with the marker) used to be exactly under the plastic pipe. Because of this, the values of the radius were altered hence changing the velocity factor in my experiment. The errors/flaws stated above can be prevented by a number of steps. Always during the experiment, the only part the hand should touch is the plastic tube only. Even if the hand touches any other part of the apparatus, the experiment should be stopped carefully and the trial should be re-done. Also, instead of using a marker on the string, he string should be tapped or tagged at the point needed. The tag should be greater than the radius of the hole of the plastic tube so that the tag does not pass through the hole, hence it will not alter the value of the desired radius.

Friday, November 22, 2019

International Management Accounting Case Study Example | Topics and Well Written Essays - 500 words

International Management Accounting - Case Study Example By using this technique, Toyota sets goals for cost reduction, and then tries to achieve these new targets through design changes that will accomplish the cost reduction goal. Toyota goes through a vigorous testing phase to judge the costs of the new design in comparison with the old one, in order to guarantee a cost reduction after implementation of the new technique. This is the main idea that Toyota uses to achieve their company wide goals. Toyota Co made changes to existing automobiles and not the design of new ones.There are several steps in the sequence of price, production, and cost decisions.Toyota first decides what the new retail price of the automobile is going to be by taking the old price and adding the value of any new functions.The sales division comes up with the suggested production volume, by taking past numbers and indexing them to market trends and the state of competitors.After all these figures have been set, the focus switches to cost planning.This cost plan is based on the product plan and the targets for retail price and production volume.Toyota establishes a profit target that is subtracted to determine their target cost. These cost planning decisions are made three years before they release the model. When Toyota estimates the approximate costs of a

Wednesday, November 20, 2019

SP Essay Example | Topics and Well Written Essays - 250 words

SP - Essay Example I love most the way research gives researchers the opportunity to express emotions and opinions in words that touch, inspire, and influence other people. It is my hope that as a researcher, I shall instill knowledge and motivate other upcoming researchers. I am convinced that I will also learn in depth the concepts of Educational Statistics, Data Analysis, Qualitative Research, and Organizational Development. I shall use the knowledge I acquire here to increase student learning and achievements as measured on standardized scores. I always wanted to do something with my life that would ensure that I am giving back to the society. This was a motivation I got from my mother at a tender age. I therefore, intent to use the concepts I learn to inspire other people. I have always looked forward to expanding my theoretical and practical knowledge. I am convinced that my study in your well-regarded institution with such a long-term record of academic excellence backed by expert faculty and excellent research services will be a meaningful and rewarding experience. I look forward to an opportunity to study in your highly esteemed institution. With my commitment, persistence, and patience to succeed, I believe I shall see my dreams come

Monday, November 18, 2019

Deaf readings and Questionss 2 Coursework Example | Topics and Well Written Essays - 250 words

Deaf readings and Questionss 2 - Coursework Example The fact factors like gender and language also further disintegrates the students, both the disabled and the abled, should be something that can be dealt with. Parents should expose their children to different languages at an early age to avoid inconveniences. These are both the spoken and the written language (24). This would help avoid discrimination. Mertens 1990, after a thorough research on academic performance for both the students with hearing problems and the hearing students, came up with a surprising report. The performance of the hearing students was way higher than that of the non-hearing students. This may raise critics against the combined mode of learning which is putting them all in a common institution. To avoid this, i advocate that although they are to learn in the same environment, there has to be some extra or rather special classes of either of the hearing or the hard of hearing students so as to put them on almost the same

Saturday, November 16, 2019

Drugs in the Treatment of Gastrointestinal Disease

Drugs in the Treatment of Gastrointestinal Disease Introduction Many of the drug groups discussed elsewhere in this book have important applications in the treatment of diseases of the gastrointestinal tract and other organs. Other groups are used almost exclusively for their effects on the gut; these are discussed in the following text according to their therapeutic uses. Drugs Used in Acid-Peptic Diseases Acid-peptic diseases include gastroesophageal reflux, peptic ulcer (gastric and duodenal), and stress-related mucosal injury. In all these conditions, mucosal erosions or ulceration arise when the caustic effects of aggressive factors (acid, pepsin, bile) overwhelm the defensive factors of the gastrointestinal mucosa (mucus and bicarbonate secretion, prostaglandins, blood flow, and the processes of restitution and regeneration after cellular injury). Over 90% of peptic ulcers are caused by infection with the bacterium Helicobacter pylori or by use of nonsteroidal anti-inflammatory drugs (NSAIDs). Drugs used in the treatment of acid-peptic disorders may be divided into two classes: agents that reduce intragastric acidity and agents that promote mucosal defense. Agents that Reduce Intragastric Acidity Physiology of Acid Secretion The parietal cell contains receptors for gastrin (CCK-B), histamine (H2), and acetylcholine (muscarinic, M3) (Figure 62-1). When acetylcholine (from vagal postganglionic nerves) or gastrin (released from antral G cells into the blood) bind to the parietal cell receptors, they cause an increase in cytosolic calcium, which in turn stimulates protein kinases that stimulate acid secretion from a H+,K+ ATPase (the proton pump) on the canalicular surface. In close proximity to the parietal cells are gut endocrine cells called enterochromaffin-like (ECL) cells. ECL cells also have receptors for gastrin and acetylcholine, which stimulate histamine release. Histamine binds to the H2 receptor on the parietal cell, resulting in activation of adenylyl cyclase, which increases intracellular cyclic adenosine monophosphate (cAMP) and activates protein kinases that stimulate acid secretion by the H+,K+ ATPase. In humans, it is believed that the major effect of gastrin upon acid secretion is mediated indirectly through the release of histamine from ECL cells rather than through direct parietal cell stimulation. In contrast, acetylcholine provides potent direct parietal cell stimulation. Antacids Antacids have been used for centuries in the treatment of patients with dyspepsia and acid-peptic disorders. They were the mainstay of treatment for acid-peptic disorders until the advent of H2-receptor antagonists and proton pump inhibitors. They continue to be used commonly by patients as nonprescription remedies for the treatment of intermittent heartburn and dyspepsia. Antacids are weak bases that react with gastric hydrochloric acid to form a salt and water. Their principal mechanism of action is reduction of intragastric acidity. After a meal, approximately 45 mEq/h of hydrochloric acid is secreted. A single dose of 156 mEq of antacid given 1 hour after a meal effectively neutralizes gastric acid for up to 2 hours. However, the acid-neutralization capacity among different proprietary formulations of antacids is highly variable, depending on their rate of dissolution (tablet versus liquid), water solubility, rate of reaction with acid, and rate of gastric emptying. Sodium bicarbonate (eg, baking soda, Alka Seltzer) reacts rapidly with hydrochloric acid (HCL) to produce carbon dioxide and sodium chloride. Formation of carbon dioxide results in gastric distention and belching. Unreacted alkali is readily absorbed, potentially causing metabolic alkalosis when given in high doses or to patients with renal insufficiency. Sodium chloride absorption may exacerbate fluid retention in patients with heart failure, hypertension, and renal insufficiency. Calcium carbonate (eg, Tums, Os-Cal) is less soluble and reacts more slowly than sodium bicarbonate with HCl to form carbon dioxide and calcium chloride (CaCl2). Like sodium bicarbonate, calcium carbonate may cause belching or metabolic alkalosis. Calcium carbonate is used for a number of other indications apart from its antacid properties (see Chapter 42). Excessive doses of either sodium bicarbonate or calcium carbonate with calcium-containing dairy products can lead to hypercalcemia, renal insufficiency , and metabolic alkalosis (milk-alkali syndrome). Formulations containing magnesium hydroxide or aluminum hydroxide react slowly with HCl to form magnesium chloride or aluminum chloride and water. Because no gas is generated, belching does not occur. Metabolic alkalosis is also uncommon because of the efficiency of the neutralization reaction. Because unabsorbed magnesium salts may cause an osmotic diarrhea and aluminum salts may cause constipation, these agents are commonly administered together in proprietary formulations (eg, Gelusil, Maalox, Mylanta) to minimize the impact on bowel function. Both magnesium and aluminum are absorbed and excreted by the kidneys. Hence, patients with renal insufficiency should not take these agents long-term. All antacids may affect the absorption of other medications by binding the drug (reducing its absorption) or by increasing intragastric pH so that the drugs dissolution or solubility (especially weakly basic or acidic drugs) is altered. Therefore, antacids should not be given within 2 hours of doses of tetracyclines, fluoroquinolones, itraconazole, and iron. H2-Receptor Antagonists From their introduction in the 1970s until the early 1990s, H2-receptor antagonists (commonly referred to as H2 blockers) were the most commonly prescribed drugs in the world (see Clinical Uses). With the recognition of the role of H pylori in ulcer disease (which may be treated with appropriate antibacterial therapy) and the advent of proton pump inhibitors, the use of prescription H2 blockers has declined markedly. Chemistry Pharmacokinetics Four H2 antagonists are in clinical use: cimetidine, ranitidine, famotidine, and nizatidine. All four agents are rapidly absorbed from the intestine. Cimetidine, ranitidine, and famotidine undergo first-pass hepatic metabolism resulting in a bioavailability of approximately 50%. Nizatidine has little first-pass metabolism. The serum half-lives of the four agents range from 1.1 to 4 hours; however, duration of action depends on the dose given (Table 62-1). H2 antagonists are cleared by a combination of hepatic metabolism, glomerular filtration, and renal tubular secretion. Dose reduction is required in patients with moderate to severe renal (and possibly severe hepatic) insufficiency. In the elderly, there is a decline of up to 50% in drug clearance as well as a significant reduction in volume of distribution. BID, twice daily; HS, bedtime. Clinical Uses H2-receptor antagonists continue to be prescribed but proton pump inhibitors (see below) are steadily replacing H2 antagonists for most clinical indications. However, the over-the-counter preparations are heavily used by the public. Gastroesophageal Reflux Disease (GERD) Patients with infrequent heartburn or dyspepsia (fewer than 3 times per week) may take either antacids or intermittent H2 antagonists. Because antacids provide rapid acid neutralization, they afford faster symptom relief than H2 antagonists. However, the effect of antacids is short-lived (1-2 hours) compared with H2 antagonists (6-10 hours). H2 antagonists may be taken prophylactically before meals in an effort to reduce the likelihood of heartburn. Frequent heartburn is better treated with twice-daily H2 antagonists (Table 62-1) or proton pump inhibitors. In patients with erosive esophagitis (approximately 50% of patients with GERD), H2 antagonists afford healing in less than 50% of patients; hence proton pump inhibitors are preferred because of their superior acid inhibition. Peptic Ulcer Disease Proton pump inhibitors have largely replaced H2 antagonists in the treatment of acute peptic ulcer disease. Nevertheless, H2 antagonists are still sometimes used. Nocturnal acid suppression by H2 antagonists affords effective ulcer healing in most patients with uncomplicated gastric and duodenal ulcers. Hence, all the agents may be administered once daily at bedtime, resulting in ulcer healing rates of more than 80-90% after 6-8 weeks of therapy. For patients with ulcers caused by aspirin or other NSAIDs, the NSAID should be discontinued. If the NSAID must be continued for clinical reasons despite active ulceration, a proton pump inhibitor should be given instead of an H2 antagonist to more reliably promote ulcer healing. For patients with acute peptic ulcers caused by H pylori, H2 antagonists no longer play a significant therapeutic role. H pylori should be treated with a 10- to 14-day course of therapy including a proton pump inhibitor and two antibiotics (see below). This regimen achieves ulcer healing and eradication of the infection in more than 90% of patients. For the minority of patients in whom H pylori cannot be successfully eradicated, H2 antagonists may be given daily at bedtime in half of the usual ulcer therapeutic dose to prevent ulcer recurrence (eg, ranitidine, 150 mg; famotidine, 20 mg). Nonulcer Dyspepsia H2 antagonists are commonly used as over-the-counter agents and prescription agents for treatment of intermittent dyspepsia not caused by peptic ulcer. However, benefit compared with placebo has never been convincingly demonstrated. Prevention of Bleeding from Stress-Related Gastritis Clinically important bleeding from upper gastrointestinal erosions or ulcers occurs in 1-5% of critically ill patients as a result of impaired mucosal defense mechanisms caused by poor perfusion. Although most critically ill patients have normal or decreased acid secretion, numerous studies have shown that agents that increase intragastric pH (H2 antagonists or proton pump inhibitors) reduce the incidence of clinically significant bleeding. However, the optimal agent is uncertain at this time. For patients without a nasoenteric tube or with significant ileus, intravenous H2 antagonists are preferable over intravenous proton pump inhibitors because of their proven efficacy and lower cost. Continuous infusions of H2 antagonists are generally preferred to bolus infusions because they achieve more consistent, sustained elevation of intragastric pH. Adverse Effects H2 antagonists are extremely safe drugs. Adverse effects occur in less than 3% of patients and include diarrhea, headache, fatigue, myalgias, and constipation. Some studies suggest that intravenous H2 antagonists (or proton pump inhibitors) may increase the risk of nosocomial pneumonia in critically ill patients. Mental status changes (confusion, hallucinations, agitation) may occur with administration of intravenous H2 antagonists, especially in patients in the intensive care unit who are elderly or who have renal or hepatic dysfunction. These events may be more common with cimetidine. Mental status changes rarely occur in ambulatory patients. Cimetidine inhibits binding of dihydrotestosterone to androgen receptors, inhibits metabolism of estradiol, and increases serum prolactin levels. When used long-term or in high doses, it may cause gynecomastia or impotence in men and galactorrhea in women. These effects are specific to cimetidine and do not occur with the other H2 antagonists. Although there are no known harmful effects on the fetus, H2 antagonists cross the placenta. Therefore, they should not be administered to pregnant women unless absolutely necessary. The H2 antagonists are secreted into breast milk and may therefore affect nursing infants. H2 antagonists may rarely cause blood dyscrasias. Blockade of cardiac H2 receptors may cause bradycardia, but this is rarely of clinical significance. Rapid intravenous infusion may cause bradycardia and hypotension through blockade of cardiac H2 receptors; therefore, intravenous injections should be given over 30 minutes. H2 antagonists rarely cause reversible abnormalities in liver chemistry. Drug Interactions Cimetidine interferes with several important hepatic cytochrome P450 drug metabolism pathways, including those catalyzed by CYP1A2, CYP2C9, CYP2D6, and CYP3A4 (see Chapter 4). Hence, the half-lives of drugs metabolized by these pathways may be prolonged. Ranitidine binds 4-10 times less avidly than cimetidine to cytochrome P450. Negligible interaction occurs with nizatidine and famotidine. H2 antagonists compete with creatinine and certain drugs (eg, procainamide) for renal tubular secretion. All of these agents except famotidine inhibit gastric first-pass metabolism of ethanol, especially in women. Although the importance of this is debated, increased bioavailability of ethanol could lead to increased blood ethanol levels. Proton Pump Inhibitors Since their introduction in the late 1980s, these efficacious acid inhibitory agents have assumed the major role for the treatment of acid-peptic disorders. Proton pump inhibitors (PPIs) are now among the most widely prescribed drugs worldwide due to their outstanding efficacy and safety. Chemistry Pharmacokinetics Five proton pump inhibitors are available for clinical use: omeprazole, lansoprazole, rabeprazole, pantoprazole, and esomeprazole. All are substituted benzimidazoles that resemble H2 antagonists in structure (Figure 62-3) but have a completely different mechanism of action. Omeprazole is a racemic mixture of R- and S-isomers. Esomeprazole is the S-isomer of omeprazole. All are available in oral formulations. Esomeprazole and pantoprazole are also available in intravenous formulations . Proton pump inhibitors are administered as inactive prodrugs. To protect the acid-labile prodrug from rapid destruction within the gastric lumen, oral products are formulated for delayed release as acid-resistant, enteric-coated capsules or tablets. After passing through the stomach into the alkaline intestinal lumen, the enteric coatings dissolve and the prodrug is absorbed. For children or patients with dysphagia or enteral feeding tubes, capsules may be opened and the microgranules mixed with apple or orange juice or mixed with soft foods (eg, applesauce). Lansoprazole is also available as a tablet formulation that disintegrates in the mouth, or it may be mixed with water and administered via oral syringe or enteral tube. Omeprazole is also available as a powder formulation (capsule or packet) that contains sodium bicarbonate (1100-1680 mg NaHCO3 ; 304-460 mg of sodium) to protect the naked (non-enteric-coated) drug from acid degradation. When administered on an empty stomach by m outh or enteral tube, this immediate-release suspension results in rapid omeprazole absorption (Tmax The proton pump inhibitors are lipophilic weak bases (pKa 4-5) and after intestinal absorption diffuse readily across lipid membranes into acidified compartments (eg, the parietal cell canaliculus). The prodrug rapidly becomes protonated within the canaliculus and is concentrated more than 1000-fold by Henderson-Hasselbalch trapping (see Chapter 1). There, it rapidly undergoes a molecular conversion to the active form, a reactive thiophilic sulfenamide cation, which forms a covalent disulfide bond with the H+,K+ ATPase, irreversibly inactivating the enzyme. From a pharmacokinetic perspective, proton pump inhibitors are ideal drugs: they have a short serum half-life, they are concentrated and activated near their site of action, and they have a long duration of action. Pharmacodynamics In contrast to H2 antagonists, proton pump inhibitors inhibit both fasting and meal-stimulated secretion because they block the final common pathway of acid secretion, the proton pump. In standard doses, proton pump inhibitors inhibit 90-98% of 24-hour acid secretion (Figure 62-2). When administered at equivalent doses, the different agents show little difference in clinical efficacy. In a crossover study of patients receiving long-term therapy with all five proton pump inhibitors, the mean 24-hour intragastric pH varied from 3.3 (pantoprazole, 40 mg) to 4.0 (esomeprazole, 40 mg) and the mean number of hours the pH was higher than 4 varied from 10.1 (pantoprazole, 40 mg) to 14.0 (esomeprazole, 40 mg). Clinical Uses Gastroesophageal Reflux Disease (GERD) Proton pump inhibitors are the most effective agents for the treatment of nonerosive and erosive reflux disease, esophageal complications of reflux disease (peptic stricture or Barretts esophagus), and extraesophageal manifestations of reflux disease. Once-daily dosing provides effective symptom relief and tissue healing in 85-90% of patients; up to 15% of patients require twice-daily dosing. GERD symptoms recur in over 80% of patients within 6 months after discontinuation of a proton pump inhibitor. For patients with erosive esophagitis or esophageal complications, long-term daily maintenance therapy with a full-dose or half-dose proton pump inhibitor is usually needed. Many patients with nonerosive GERD may be treated successfully with intermittent courses of proton pump inhibitors or H2 antagonists taken as needed (on demand) for recurrent symptoms. In current clinical practice, many patients with symptomatic GERD are treated empirically with medications without prior endoscopy, ie, without knowledge of whether the patient has erosive or nonerosive reflux disease. Empiric treatment with proton pump inhibitors provides sustained symptomatic relief in 70-80% of patients, compared with 50-60% with H2 antagonists. Because of recent cost reductions, proton pump inhibitors are being used increasingly as first-line therapy for patients with symptomatic GERD. Sustained acid suppression with twice-daily proton pump inhibitors for at least 3 months is used to treat extraesophageal complications of reflux disease (asthma, chronic cough, laryngitis, and noncardiac chest pain). Peptic Ulcer Disease Compared with H2 antagonists, proton pump inhibitors afford more rapid symptom relief and faster ulcer healing for duodenal ulcers and, to a lesser extent, gastric ulcers. All the pump inhibitors heal more than 90% of duodenal ulcers within 4 weeks and a similar percentage of gastric ulcers within 6-8 weeks. H pylori-Associated Ulcers For H pylori-associated ulcers, there are two therapeutic goals: to heal the ulcer and to eradicate the organism. The most effective regimens for H pylori eradication are combinations of two antibiotics and a proton pump inhibitor. Proton pump inhibitors promote eradication of H pylori through several mechanisms: direct antimicrobial properties (minor) and—by raising intragastric pH—lowering the minimal inhibitory concentrations of antibiotics against H pylori. The best treatment regimen consists of a 14-day regimen of triple therapy: a proton pump inhibitor twice daily; clarithromycin, 500 mg twice daily; and either amoxicillin, 1 g twice daily, or metronidazole, 500 mg twice daily. After completion of triple therapy, the proton pump inhibitor should be continued once daily for a total of 4-6 weeks to ensure complete ulcer healing. Recently, 10 days of sequential treatment consisting on days 1-5 of a proton pump inhibitor twice daily plus amoxicillin, 1 g twice daily, and followed on days 6-10 by five additional days of a proton pump inhibitor twice daily, plus clarithromycin, 500 mg twice daily, and tinidazole, 500 mg twice daily, has been shown to be a highly effective treatment regimen. NSAID-Associated Ulcers For patients with ulcers caused by aspirin or other NSAIDs, either H2 antagonists or proton pump inhibitors provide rapid ulcer healing so long as the NSAID is discontinued; however continued use of the NSAID impairs ulcer healing. In patients with NSAID-induced ulcers who require continued NSAID therapy, treatment with a once- or twice-daily proton pump inhibitor more reliably promotes ulcer healing. Asymptomatic peptic ulceration develops in 10-20% of people taking frequent NSAIDs, and ulcer-related complications (bleeding, perforation) develop in 1-2% of persons per year. Proton pump inhibitors taken once daily are effective in reducing the incidence of ulcers and ulcer complications in patients taking aspirin or other NSAIDs. Prevention of Rebleeding from Peptic Ulcers In patients with acute gastrointestinal bleeding due to peptic ulcers, the risk of rebleeding from ulcers that have a visible vessel or adherent clot is increased. Rebleeding of this subset of high-risk ulcers is reduced significantly with proton pump inhibitors administered for 3-5 days either as high-dose oral therapy (eg, omeprazole, 40 mg orally twice daily) or as a continuous intravenous infusion. It is believed that an intragastric pH higher than 6 may enhance coagulation and platelet aggregation. The optimal dose of intravenous proton pump inhibitor needed to achieve and maintain this level of near-complete acid inhibition is unknown; however, initial bolus administration (80 mg) followed by constant infusion (8 mg/h) is commonly recommended. Nonulcer Dyspepsia Proton pump inhibitors have modest efficacy for treatment of nonulcer dyspepsia, benefiting 10-20% more patients than placebo. Despite their use for this indication, superiority to H2 antagonists (or even placebo) has not been conclusively demonstrated. Prevention of Stress-Related Mucosal Bleeding As discussed previously (see H2-Receptor Antagonists) proton pump inhibitors (given orally, by nasogastric tube, or by intravenous infusions) may be administered to reduce the risk of clinically significant stress-related mucosal bleeding in critically ill patients. The only proton pump inhibitor approved by the Food and Drug Administration (FDA) for this indication is an oral immediate-release omeprazole formulation, which is administered by nasogastric tube twice daily on the first day, then once daily. For patients with nasoenteric tubes, immediate-release omeprazole may be preferred to intravenous H2 antagonists or proton pump inhibitors because of comparable efficacy, lower cost, and ease of administration. For patients without a nasoenteric tube or with significant ileus, intravenous H2 antagonists are preferred to intravenous proton pump inhibitors because of their proven efficacy and lower cost. Although proton pump inhibitors are increasingly used, there are no controlled trials demonstrating efficacy or optimal dosing. Gastrinoma and Other Hypersecretory Conditions Patients with isolated gastrinomas are best treated with surgical resection. In patients with metastatic or unresectable gastrinomas, massive acid hypersecretion results in peptic ulceration, erosive esophagitis, and malabsorption. Previously, these patients required vagotomy and extraordinarily high doses of H2 antagonists, which still resulted in suboptimal acid suppression. With proton pump inhibitors, excellent acid suppression can be achieved in all patients. Dosage is titrated to reduce basal acid output to less than 5-10 mEq/h. Typical doses of omeprazole are 60-120 mg/d. Adverse Effects General Proton pump inhibitors are extremely safe. Diarrhea, headache, and abdominal pain are reported in 1-5% of patients, although the frequency of these events is only slightly increased compared with placebo. Proton pump inhibitors do not have teratogenicity in animal models; however, safety during pregnancy has not been established. Nutrition Acid is important in releasing vitamin B12 from food. A minor reduction in oral cyanocobalamin absorption occurs during proton pump inhibition, potentially leading to subnormal B12 levels with prolonged therapy. Acid also promotes absorption of food-bound minerals (iron, calcium, zinc); however, no mineral deficiencies have been reported with proton pump inhibitor therapy. Recent case-control studies have suggested a modest increase in the risk of hip fracture in patients taking proton pump inhibitors over a long term compared with matched controls. Although a causal relationship is unproven, proton pump inhibitors may reduce calcium absorption or inhibit osteoclast function. Pending further studies, patients who require long-term proton pump inhibitors—especially those with risk factors for osteoporosis—should have monitoring of bone density and should be provided calcium supplements. Respiratory and Enteric Infections Gastric acid is an important barrier to colonization and infection of the stomach and intestine from ingested bacteria. Increases in gastric bacterial concentrations are detected in patients taking proton pump inhibitors, which is of unknown clinical significance. Some studies have reported an increased risk of both community-acquired respiratory infections and nosocomial pneumonia among patients taking proton pump inhibitors. A small increased risk of enteric infections may exist in patients taking proton pump inhibitors, especially when traveling in underdeveloped countries. Hospitalized patients may have an increased risk for Clostridium difficile infection. Potential Problems Due to Increased Serum Gastrin Gastrin levels are regulated by intragastric acidity. Acid suppression alters normal feedback inhibition so that median serum gastrin levels rise 1.5- to 2-fold in patients taking proton pump inhibitors. Although gastrin levels remain within normal limits in most patients, they exceed 500 pg/mL (normal, The rise in serum gastrin levels in patients receiving long-term therapy with proton pump inhibitors raises a theoretical concern because gastrin may stimulate hyperplasia of ECL cells. In female rats given proton pump inhibitors for prolonged periods, gastric carcinoid tumors developed in areas of ECL hyperplasia. Although humans who take proton pump inhibitors for a long time may exhibit ECL hyperplasia in response to hypergastrinemia, carcinoid tumor formation has not been documented. At present, routine monitoring of serum gastrin levels is not recommended in patients receiving prolonged proton pump inhibitor therapy. Other Potential Problems Due to Decreased Gastric Acidity Among patients infected with H pylori, long-term acid suppression leads to increased chronic inflammation in the gastric body and decreased inflammation in the antrum. Concerns have been raised that increased gastric inflammation may accelerate gastric gland atrophy (atrophic gastritis) and intestinal metaplasia—known risk factors for gastric adenocarcinoma. A special FDA Gastrointestinal Advisory Committee concluded that there is no evidence that prolonged proton pump inhibitor therapy produces the kind of atrophic gastritis (multifocal atrophic gastritis) or intestinal metaplasia that is associated with increased risk of adenocarcinoma. Routine testing for H pylori is not recommended in patients who require long-term proton pump inhibitor therapy. Long-term proton pump inhibitor therapy is associated with the development of small benign gastric fundic-gland polyps in a small number of patients, which may disappear after stopping the drug and are of uncertain clinical signifi cance. Drug Interactions Decreased gastric acidity may alter absorption of drugs for which intragastric acidity affects drug bioavailability, eg, ketoconazole, itraconazole, digoxin, and atazanavir. All proton pump inhibitors are metabolized by hepatic P450 cytochromes, including CYP2C19 and CYP3A4. Because of the short half-lives of proton pump inhibitors, clinically significant drug interactions are rare. Omeprazole may inhibit the metabolism of warfarin, diazepam, and phenytoin. Esomeprazole also may decrease metabolism of diazepam. Lansoprazole may enhance clearance of theophylline. Rabeprazole and pantoprazole have no significant drug interactions. Mucosal Protective Agents The gastroduodenal mucosa has evolved a number of defense mechanisms to protect itself against the noxious effects of acid and pepsin. Both mucus and epithelial cell-cell tight junctions restrict back diffusion of acid and pepsin. Epithelial bicarbonate secretion establishes a pH gradient within the mucous layer in which the pH ranges from 7 at the mucosal surface to 1-2 in the gastric lumen. Blood flow carries bicarbonate and vital nutrients to surface cells. Areas of injured epithelium are quickly repaired by restitution, a process in which migration of cells from gland neck cells seals small erosions to rees Drugs in the Treatment of Gastrointestinal Disease Drugs in the Treatment of Gastrointestinal Disease Introduction Many of the drug groups discussed elsewhere in this book have important applications in the treatment of diseases of the gastrointestinal tract and other organs. Other groups are used almost exclusively for their effects on the gut; these are discussed in the following text according to their therapeutic uses. Drugs Used in Acid-Peptic Diseases Acid-peptic diseases include gastroesophageal reflux, peptic ulcer (gastric and duodenal), and stress-related mucosal injury. In all these conditions, mucosal erosions or ulceration arise when the caustic effects of aggressive factors (acid, pepsin, bile) overwhelm the defensive factors of the gastrointestinal mucosa (mucus and bicarbonate secretion, prostaglandins, blood flow, and the processes of restitution and regeneration after cellular injury). Over 90% of peptic ulcers are caused by infection with the bacterium Helicobacter pylori or by use of nonsteroidal anti-inflammatory drugs (NSAIDs). Drugs used in the treatment of acid-peptic disorders may be divided into two classes: agents that reduce intragastric acidity and agents that promote mucosal defense. Agents that Reduce Intragastric Acidity Physiology of Acid Secretion The parietal cell contains receptors for gastrin (CCK-B), histamine (H2), and acetylcholine (muscarinic, M3) (Figure 62-1). When acetylcholine (from vagal postganglionic nerves) or gastrin (released from antral G cells into the blood) bind to the parietal cell receptors, they cause an increase in cytosolic calcium, which in turn stimulates protein kinases that stimulate acid secretion from a H+,K+ ATPase (the proton pump) on the canalicular surface. In close proximity to the parietal cells are gut endocrine cells called enterochromaffin-like (ECL) cells. ECL cells also have receptors for gastrin and acetylcholine, which stimulate histamine release. Histamine binds to the H2 receptor on the parietal cell, resulting in activation of adenylyl cyclase, which increases intracellular cyclic adenosine monophosphate (cAMP) and activates protein kinases that stimulate acid secretion by the H+,K+ ATPase. In humans, it is believed that the major effect of gastrin upon acid secretion is mediated indirectly through the release of histamine from ECL cells rather than through direct parietal cell stimulation. In contrast, acetylcholine provides potent direct parietal cell stimulation. Antacids Antacids have been used for centuries in the treatment of patients with dyspepsia and acid-peptic disorders. They were the mainstay of treatment for acid-peptic disorders until the advent of H2-receptor antagonists and proton pump inhibitors. They continue to be used commonly by patients as nonprescription remedies for the treatment of intermittent heartburn and dyspepsia. Antacids are weak bases that react with gastric hydrochloric acid to form a salt and water. Their principal mechanism of action is reduction of intragastric acidity. After a meal, approximately 45 mEq/h of hydrochloric acid is secreted. A single dose of 156 mEq of antacid given 1 hour after a meal effectively neutralizes gastric acid for up to 2 hours. However, the acid-neutralization capacity among different proprietary formulations of antacids is highly variable, depending on their rate of dissolution (tablet versus liquid), water solubility, rate of reaction with acid, and rate of gastric emptying. Sodium bicarbonate (eg, baking soda, Alka Seltzer) reacts rapidly with hydrochloric acid (HCL) to produce carbon dioxide and sodium chloride. Formation of carbon dioxide results in gastric distention and belching. Unreacted alkali is readily absorbed, potentially causing metabolic alkalosis when given in high doses or to patients with renal insufficiency. Sodium chloride absorption may exacerbate fluid retention in patients with heart failure, hypertension, and renal insufficiency. Calcium carbonate (eg, Tums, Os-Cal) is less soluble and reacts more slowly than sodium bicarbonate with HCl to form carbon dioxide and calcium chloride (CaCl2). Like sodium bicarbonate, calcium carbonate may cause belching or metabolic alkalosis. Calcium carbonate is used for a number of other indications apart from its antacid properties (see Chapter 42). Excessive doses of either sodium bicarbonate or calcium carbonate with calcium-containing dairy products can lead to hypercalcemia, renal insufficiency , and metabolic alkalosis (milk-alkali syndrome). Formulations containing magnesium hydroxide or aluminum hydroxide react slowly with HCl to form magnesium chloride or aluminum chloride and water. Because no gas is generated, belching does not occur. Metabolic alkalosis is also uncommon because of the efficiency of the neutralization reaction. Because unabsorbed magnesium salts may cause an osmotic diarrhea and aluminum salts may cause constipation, these agents are commonly administered together in proprietary formulations (eg, Gelusil, Maalox, Mylanta) to minimize the impact on bowel function. Both magnesium and aluminum are absorbed and excreted by the kidneys. Hence, patients with renal insufficiency should not take these agents long-term. All antacids may affect the absorption of other medications by binding the drug (reducing its absorption) or by increasing intragastric pH so that the drugs dissolution or solubility (especially weakly basic or acidic drugs) is altered. Therefore, antacids should not be given within 2 hours of doses of tetracyclines, fluoroquinolones, itraconazole, and iron. H2-Receptor Antagonists From their introduction in the 1970s until the early 1990s, H2-receptor antagonists (commonly referred to as H2 blockers) were the most commonly prescribed drugs in the world (see Clinical Uses). With the recognition of the role of H pylori in ulcer disease (which may be treated with appropriate antibacterial therapy) and the advent of proton pump inhibitors, the use of prescription H2 blockers has declined markedly. Chemistry Pharmacokinetics Four H2 antagonists are in clinical use: cimetidine, ranitidine, famotidine, and nizatidine. All four agents are rapidly absorbed from the intestine. Cimetidine, ranitidine, and famotidine undergo first-pass hepatic metabolism resulting in a bioavailability of approximately 50%. Nizatidine has little first-pass metabolism. The serum half-lives of the four agents range from 1.1 to 4 hours; however, duration of action depends on the dose given (Table 62-1). H2 antagonists are cleared by a combination of hepatic metabolism, glomerular filtration, and renal tubular secretion. Dose reduction is required in patients with moderate to severe renal (and possibly severe hepatic) insufficiency. In the elderly, there is a decline of up to 50% in drug clearance as well as a significant reduction in volume of distribution. BID, twice daily; HS, bedtime. Clinical Uses H2-receptor antagonists continue to be prescribed but proton pump inhibitors (see below) are steadily replacing H2 antagonists for most clinical indications. However, the over-the-counter preparations are heavily used by the public. Gastroesophageal Reflux Disease (GERD) Patients with infrequent heartburn or dyspepsia (fewer than 3 times per week) may take either antacids or intermittent H2 antagonists. Because antacids provide rapid acid neutralization, they afford faster symptom relief than H2 antagonists. However, the effect of antacids is short-lived (1-2 hours) compared with H2 antagonists (6-10 hours). H2 antagonists may be taken prophylactically before meals in an effort to reduce the likelihood of heartburn. Frequent heartburn is better treated with twice-daily H2 antagonists (Table 62-1) or proton pump inhibitors. In patients with erosive esophagitis (approximately 50% of patients with GERD), H2 antagonists afford healing in less than 50% of patients; hence proton pump inhibitors are preferred because of their superior acid inhibition. Peptic Ulcer Disease Proton pump inhibitors have largely replaced H2 antagonists in the treatment of acute peptic ulcer disease. Nevertheless, H2 antagonists are still sometimes used. Nocturnal acid suppression by H2 antagonists affords effective ulcer healing in most patients with uncomplicated gastric and duodenal ulcers. Hence, all the agents may be administered once daily at bedtime, resulting in ulcer healing rates of more than 80-90% after 6-8 weeks of therapy. For patients with ulcers caused by aspirin or other NSAIDs, the NSAID should be discontinued. If the NSAID must be continued for clinical reasons despite active ulceration, a proton pump inhibitor should be given instead of an H2 antagonist to more reliably promote ulcer healing. For patients with acute peptic ulcers caused by H pylori, H2 antagonists no longer play a significant therapeutic role. H pylori should be treated with a 10- to 14-day course of therapy including a proton pump inhibitor and two antibiotics (see below). This regimen achieves ulcer healing and eradication of the infection in more than 90% of patients. For the minority of patients in whom H pylori cannot be successfully eradicated, H2 antagonists may be given daily at bedtime in half of the usual ulcer therapeutic dose to prevent ulcer recurrence (eg, ranitidine, 150 mg; famotidine, 20 mg). Nonulcer Dyspepsia H2 antagonists are commonly used as over-the-counter agents and prescription agents for treatment of intermittent dyspepsia not caused by peptic ulcer. However, benefit compared with placebo has never been convincingly demonstrated. Prevention of Bleeding from Stress-Related Gastritis Clinically important bleeding from upper gastrointestinal erosions or ulcers occurs in 1-5% of critically ill patients as a result of impaired mucosal defense mechanisms caused by poor perfusion. Although most critically ill patients have normal or decreased acid secretion, numerous studies have shown that agents that increase intragastric pH (H2 antagonists or proton pump inhibitors) reduce the incidence of clinically significant bleeding. However, the optimal agent is uncertain at this time. For patients without a nasoenteric tube or with significant ileus, intravenous H2 antagonists are preferable over intravenous proton pump inhibitors because of their proven efficacy and lower cost. Continuous infusions of H2 antagonists are generally preferred to bolus infusions because they achieve more consistent, sustained elevation of intragastric pH. Adverse Effects H2 antagonists are extremely safe drugs. Adverse effects occur in less than 3% of patients and include diarrhea, headache, fatigue, myalgias, and constipation. Some studies suggest that intravenous H2 antagonists (or proton pump inhibitors) may increase the risk of nosocomial pneumonia in critically ill patients. Mental status changes (confusion, hallucinations, agitation) may occur with administration of intravenous H2 antagonists, especially in patients in the intensive care unit who are elderly or who have renal or hepatic dysfunction. These events may be more common with cimetidine. Mental status changes rarely occur in ambulatory patients. Cimetidine inhibits binding of dihydrotestosterone to androgen receptors, inhibits metabolism of estradiol, and increases serum prolactin levels. When used long-term or in high doses, it may cause gynecomastia or impotence in men and galactorrhea in women. These effects are specific to cimetidine and do not occur with the other H2 antagonists. Although there are no known harmful effects on the fetus, H2 antagonists cross the placenta. Therefore, they should not be administered to pregnant women unless absolutely necessary. The H2 antagonists are secreted into breast milk and may therefore affect nursing infants. H2 antagonists may rarely cause blood dyscrasias. Blockade of cardiac H2 receptors may cause bradycardia, but this is rarely of clinical significance. Rapid intravenous infusion may cause bradycardia and hypotension through blockade of cardiac H2 receptors; therefore, intravenous injections should be given over 30 minutes. H2 antagonists rarely cause reversible abnormalities in liver chemistry. Drug Interactions Cimetidine interferes with several important hepatic cytochrome P450 drug metabolism pathways, including those catalyzed by CYP1A2, CYP2C9, CYP2D6, and CYP3A4 (see Chapter 4). Hence, the half-lives of drugs metabolized by these pathways may be prolonged. Ranitidine binds 4-10 times less avidly than cimetidine to cytochrome P450. Negligible interaction occurs with nizatidine and famotidine. H2 antagonists compete with creatinine and certain drugs (eg, procainamide) for renal tubular secretion. All of these agents except famotidine inhibit gastric first-pass metabolism of ethanol, especially in women. Although the importance of this is debated, increased bioavailability of ethanol could lead to increased blood ethanol levels. Proton Pump Inhibitors Since their introduction in the late 1980s, these efficacious acid inhibitory agents have assumed the major role for the treatment of acid-peptic disorders. Proton pump inhibitors (PPIs) are now among the most widely prescribed drugs worldwide due to their outstanding efficacy and safety. Chemistry Pharmacokinetics Five proton pump inhibitors are available for clinical use: omeprazole, lansoprazole, rabeprazole, pantoprazole, and esomeprazole. All are substituted benzimidazoles that resemble H2 antagonists in structure (Figure 62-3) but have a completely different mechanism of action. Omeprazole is a racemic mixture of R- and S-isomers. Esomeprazole is the S-isomer of omeprazole. All are available in oral formulations. Esomeprazole and pantoprazole are also available in intravenous formulations . Proton pump inhibitors are administered as inactive prodrugs. To protect the acid-labile prodrug from rapid destruction within the gastric lumen, oral products are formulated for delayed release as acid-resistant, enteric-coated capsules or tablets. After passing through the stomach into the alkaline intestinal lumen, the enteric coatings dissolve and the prodrug is absorbed. For children or patients with dysphagia or enteral feeding tubes, capsules may be opened and the microgranules mixed with apple or orange juice or mixed with soft foods (eg, applesauce). Lansoprazole is also available as a tablet formulation that disintegrates in the mouth, or it may be mixed with water and administered via oral syringe or enteral tube. Omeprazole is also available as a powder formulation (capsule or packet) that contains sodium bicarbonate (1100-1680 mg NaHCO3 ; 304-460 mg of sodium) to protect the naked (non-enteric-coated) drug from acid degradation. When administered on an empty stomach by m outh or enteral tube, this immediate-release suspension results in rapid omeprazole absorption (Tmax The proton pump inhibitors are lipophilic weak bases (pKa 4-5) and after intestinal absorption diffuse readily across lipid membranes into acidified compartments (eg, the parietal cell canaliculus). The prodrug rapidly becomes protonated within the canaliculus and is concentrated more than 1000-fold by Henderson-Hasselbalch trapping (see Chapter 1). There, it rapidly undergoes a molecular conversion to the active form, a reactive thiophilic sulfenamide cation, which forms a covalent disulfide bond with the H+,K+ ATPase, irreversibly inactivating the enzyme. From a pharmacokinetic perspective, proton pump inhibitors are ideal drugs: they have a short serum half-life, they are concentrated and activated near their site of action, and they have a long duration of action. Pharmacodynamics In contrast to H2 antagonists, proton pump inhibitors inhibit both fasting and meal-stimulated secretion because they block the final common pathway of acid secretion, the proton pump. In standard doses, proton pump inhibitors inhibit 90-98% of 24-hour acid secretion (Figure 62-2). When administered at equivalent doses, the different agents show little difference in clinical efficacy. In a crossover study of patients receiving long-term therapy with all five proton pump inhibitors, the mean 24-hour intragastric pH varied from 3.3 (pantoprazole, 40 mg) to 4.0 (esomeprazole, 40 mg) and the mean number of hours the pH was higher than 4 varied from 10.1 (pantoprazole, 40 mg) to 14.0 (esomeprazole, 40 mg). Clinical Uses Gastroesophageal Reflux Disease (GERD) Proton pump inhibitors are the most effective agents for the treatment of nonerosive and erosive reflux disease, esophageal complications of reflux disease (peptic stricture or Barretts esophagus), and extraesophageal manifestations of reflux disease. Once-daily dosing provides effective symptom relief and tissue healing in 85-90% of patients; up to 15% of patients require twice-daily dosing. GERD symptoms recur in over 80% of patients within 6 months after discontinuation of a proton pump inhibitor. For patients with erosive esophagitis or esophageal complications, long-term daily maintenance therapy with a full-dose or half-dose proton pump inhibitor is usually needed. Many patients with nonerosive GERD may be treated successfully with intermittent courses of proton pump inhibitors or H2 antagonists taken as needed (on demand) for recurrent symptoms. In current clinical practice, many patients with symptomatic GERD are treated empirically with medications without prior endoscopy, ie, without knowledge of whether the patient has erosive or nonerosive reflux disease. Empiric treatment with proton pump inhibitors provides sustained symptomatic relief in 70-80% of patients, compared with 50-60% with H2 antagonists. Because of recent cost reductions, proton pump inhibitors are being used increasingly as first-line therapy for patients with symptomatic GERD. Sustained acid suppression with twice-daily proton pump inhibitors for at least 3 months is used to treat extraesophageal complications of reflux disease (asthma, chronic cough, laryngitis, and noncardiac chest pain). Peptic Ulcer Disease Compared with H2 antagonists, proton pump inhibitors afford more rapid symptom relief and faster ulcer healing for duodenal ulcers and, to a lesser extent, gastric ulcers. All the pump inhibitors heal more than 90% of duodenal ulcers within 4 weeks and a similar percentage of gastric ulcers within 6-8 weeks. H pylori-Associated Ulcers For H pylori-associated ulcers, there are two therapeutic goals: to heal the ulcer and to eradicate the organism. The most effective regimens for H pylori eradication are combinations of two antibiotics and a proton pump inhibitor. Proton pump inhibitors promote eradication of H pylori through several mechanisms: direct antimicrobial properties (minor) and—by raising intragastric pH—lowering the minimal inhibitory concentrations of antibiotics against H pylori. The best treatment regimen consists of a 14-day regimen of triple therapy: a proton pump inhibitor twice daily; clarithromycin, 500 mg twice daily; and either amoxicillin, 1 g twice daily, or metronidazole, 500 mg twice daily. After completion of triple therapy, the proton pump inhibitor should be continued once daily for a total of 4-6 weeks to ensure complete ulcer healing. Recently, 10 days of sequential treatment consisting on days 1-5 of a proton pump inhibitor twice daily plus amoxicillin, 1 g twice daily, and followed on days 6-10 by five additional days of a proton pump inhibitor twice daily, plus clarithromycin, 500 mg twice daily, and tinidazole, 500 mg twice daily, has been shown to be a highly effective treatment regimen. NSAID-Associated Ulcers For patients with ulcers caused by aspirin or other NSAIDs, either H2 antagonists or proton pump inhibitors provide rapid ulcer healing so long as the NSAID is discontinued; however continued use of the NSAID impairs ulcer healing. In patients with NSAID-induced ulcers who require continued NSAID therapy, treatment with a once- or twice-daily proton pump inhibitor more reliably promotes ulcer healing. Asymptomatic peptic ulceration develops in 10-20% of people taking frequent NSAIDs, and ulcer-related complications (bleeding, perforation) develop in 1-2% of persons per year. Proton pump inhibitors taken once daily are effective in reducing the incidence of ulcers and ulcer complications in patients taking aspirin or other NSAIDs. Prevention of Rebleeding from Peptic Ulcers In patients with acute gastrointestinal bleeding due to peptic ulcers, the risk of rebleeding from ulcers that have a visible vessel or adherent clot is increased. Rebleeding of this subset of high-risk ulcers is reduced significantly with proton pump inhibitors administered for 3-5 days either as high-dose oral therapy (eg, omeprazole, 40 mg orally twice daily) or as a continuous intravenous infusion. It is believed that an intragastric pH higher than 6 may enhance coagulation and platelet aggregation. The optimal dose of intravenous proton pump inhibitor needed to achieve and maintain this level of near-complete acid inhibition is unknown; however, initial bolus administration (80 mg) followed by constant infusion (8 mg/h) is commonly recommended. Nonulcer Dyspepsia Proton pump inhibitors have modest efficacy for treatment of nonulcer dyspepsia, benefiting 10-20% more patients than placebo. Despite their use for this indication, superiority to H2 antagonists (or even placebo) has not been conclusively demonstrated. Prevention of Stress-Related Mucosal Bleeding As discussed previously (see H2-Receptor Antagonists) proton pump inhibitors (given orally, by nasogastric tube, or by intravenous infusions) may be administered to reduce the risk of clinically significant stress-related mucosal bleeding in critically ill patients. The only proton pump inhibitor approved by the Food and Drug Administration (FDA) for this indication is an oral immediate-release omeprazole formulation, which is administered by nasogastric tube twice daily on the first day, then once daily. For patients with nasoenteric tubes, immediate-release omeprazole may be preferred to intravenous H2 antagonists or proton pump inhibitors because of comparable efficacy, lower cost, and ease of administration. For patients without a nasoenteric tube or with significant ileus, intravenous H2 antagonists are preferred to intravenous proton pump inhibitors because of their proven efficacy and lower cost. Although proton pump inhibitors are increasingly used, there are no controlled trials demonstrating efficacy or optimal dosing. Gastrinoma and Other Hypersecretory Conditions Patients with isolated gastrinomas are best treated with surgical resection. In patients with metastatic or unresectable gastrinomas, massive acid hypersecretion results in peptic ulceration, erosive esophagitis, and malabsorption. Previously, these patients required vagotomy and extraordinarily high doses of H2 antagonists, which still resulted in suboptimal acid suppression. With proton pump inhibitors, excellent acid suppression can be achieved in all patients. Dosage is titrated to reduce basal acid output to less than 5-10 mEq/h. Typical doses of omeprazole are 60-120 mg/d. Adverse Effects General Proton pump inhibitors are extremely safe. Diarrhea, headache, and abdominal pain are reported in 1-5% of patients, although the frequency of these events is only slightly increased compared with placebo. Proton pump inhibitors do not have teratogenicity in animal models; however, safety during pregnancy has not been established. Nutrition Acid is important in releasing vitamin B12 from food. A minor reduction in oral cyanocobalamin absorption occurs during proton pump inhibition, potentially leading to subnormal B12 levels with prolonged therapy. Acid also promotes absorption of food-bound minerals (iron, calcium, zinc); however, no mineral deficiencies have been reported with proton pump inhibitor therapy. Recent case-control studies have suggested a modest increase in the risk of hip fracture in patients taking proton pump inhibitors over a long term compared with matched controls. Although a causal relationship is unproven, proton pump inhibitors may reduce calcium absorption or inhibit osteoclast function. Pending further studies, patients who require long-term proton pump inhibitors—especially those with risk factors for osteoporosis—should have monitoring of bone density and should be provided calcium supplements. Respiratory and Enteric Infections Gastric acid is an important barrier to colonization and infection of the stomach and intestine from ingested bacteria. Increases in gastric bacterial concentrations are detected in patients taking proton pump inhibitors, which is of unknown clinical significance. Some studies have reported an increased risk of both community-acquired respiratory infections and nosocomial pneumonia among patients taking proton pump inhibitors. A small increased risk of enteric infections may exist in patients taking proton pump inhibitors, especially when traveling in underdeveloped countries. Hospitalized patients may have an increased risk for Clostridium difficile infection. Potential Problems Due to Increased Serum Gastrin Gastrin levels are regulated by intragastric acidity. Acid suppression alters normal feedback inhibition so that median serum gastrin levels rise 1.5- to 2-fold in patients taking proton pump inhibitors. Although gastrin levels remain within normal limits in most patients, they exceed 500 pg/mL (normal, The rise in serum gastrin levels in patients receiving long-term therapy with proton pump inhibitors raises a theoretical concern because gastrin may stimulate hyperplasia of ECL cells. In female rats given proton pump inhibitors for prolonged periods, gastric carcinoid tumors developed in areas of ECL hyperplasia. Although humans who take proton pump inhibitors for a long time may exhibit ECL hyperplasia in response to hypergastrinemia, carcinoid tumor formation has not been documented. At present, routine monitoring of serum gastrin levels is not recommended in patients receiving prolonged proton pump inhibitor therapy. Other Potential Problems Due to Decreased Gastric Acidity Among patients infected with H pylori, long-term acid suppression leads to increased chronic inflammation in the gastric body and decreased inflammation in the antrum. Concerns have been raised that increased gastric inflammation may accelerate gastric gland atrophy (atrophic gastritis) and intestinal metaplasia—known risk factors for gastric adenocarcinoma. A special FDA Gastrointestinal Advisory Committee concluded that there is no evidence that prolonged proton pump inhibitor therapy produces the kind of atrophic gastritis (multifocal atrophic gastritis) or intestinal metaplasia that is associated with increased risk of adenocarcinoma. Routine testing for H pylori is not recommended in patients who require long-term proton pump inhibitor therapy. Long-term proton pump inhibitor therapy is associated with the development of small benign gastric fundic-gland polyps in a small number of patients, which may disappear after stopping the drug and are of uncertain clinical signifi cance. Drug Interactions Decreased gastric acidity may alter absorption of drugs for which intragastric acidity affects drug bioavailability, eg, ketoconazole, itraconazole, digoxin, and atazanavir. All proton pump inhibitors are metabolized by hepatic P450 cytochromes, including CYP2C19 and CYP3A4. Because of the short half-lives of proton pump inhibitors, clinically significant drug interactions are rare. Omeprazole may inhibit the metabolism of warfarin, diazepam, and phenytoin. Esomeprazole also may decrease metabolism of diazepam. Lansoprazole may enhance clearance of theophylline. Rabeprazole and pantoprazole have no significant drug interactions. Mucosal Protective Agents The gastroduodenal mucosa has evolved a number of defense mechanisms to protect itself against the noxious effects of acid and pepsin. Both mucus and epithelial cell-cell tight junctions restrict back diffusion of acid and pepsin. Epithelial bicarbonate secretion establishes a pH gradient within the mucous layer in which the pH ranges from 7 at the mucosal surface to 1-2 in the gastric lumen. Blood flow carries bicarbonate and vital nutrients to surface cells. Areas of injured epithelium are quickly repaired by restitution, a process in which migration of cells from gland neck cells seals small erosions to rees

Wednesday, November 13, 2019

Essay example --

The Red Farm Power is a great tool, but like the hammer it can build and destroy civilizations. This is the theme and lesson that I learned from George Orwell’s classic novel, Animal Farm. It is believed, and can be notably seen in the past, that many great people, like Julius Cesar and Napoleon, become dangerous and corrupt under vast amounts of power. Both wanted to own the world and extend the wealth of their country but ended up evil in the eyes of many. In history there seems to be a pattern of people at the top, the kings and rulers, falling to their deaths. These type of situations usually happen because the "lower classes" becomes irrelevant and has nothing in their lives. They see the king with all this power and realize that power can bring them happiness as well. Yet Having so much power is not always a good thing. In George Orwell’s novel, Animal Farm, a scary depiction of life in what we can assume to be a corruption of Socialist Ideals, in other words the "Soviet Union", is played out. In the novel personification is used on farm animals. The animals can talk and communicate, think, and even have feeling towards each other as if they were human. In the novel, George Orwell created a character named Napoleon. He is a pig who emerges as the leader of Animal Farm after the rebellion, and in many ways he is has the characteristics of the Soviet Leader, Joseph Stalin. In the begging he seems to be a good leader; unfortunately like history as proven before, he is eventually overcome in greed and a desire for power. In real life this is how Joseph Stalin became, after suspecting many people in his empire to be followers of Trotsky he became a very evil man. In real life Lion Trotsky and Joseph Stalin where political ... ...apoleons farm with fake bank notes, this sparks a war and blood is shed all over. Many animals die but despite the loss, Napoleons farm wins. The war is once again blamed on Snowball. The last significant event that leads to Napoleon's complete communist control is the killing of Boxer. With Boxer out of the picture, Napoleon ruled the farm with his dogs by his side, and the farm was back to how it began, except instead of humans controlling, the pigs and dogs did. Power is a great tool, but like the hammer it can build and destroy civilizations. To me nothing summarizes this novel better. The novel has enlightened me on the history of Soviet Union and how it was created and ran as a country. Till I read this book i had never heard of Lion Trotsky. Over all George Orwell's classic novel, Animal Farm was a great book and I loved readying it.

Monday, November 11, 2019

Discuss Austen(TM)s use of Mr Elliot in Persuasion

Austen uses Mr Elliot in various ways in Persuasion, this ranges from gaining an insight into other people's characters to contributing to the romance genre. Austen mainly uses Mr Elliot as a plot device in Book Two of the novel after Anne's arrival in Bath. The use of Mr Elliot's character can be tied into most of the major themes of the novel. The first mention of Mr Elliot in Persuasion is in the fist chapter of Book One. We find out that he is the heir presumptive to the Baronetcy, through Sir Walter who is reading the Baronetage. We can see that this is important to Sir Walter as he has added, â€Å"Heir presumptive, William Walter Elliot, Esq.† to the pages in the book referring to the Elliot's. This shows how class conscious Sir Walter is, it is blatantly obvious that Austen is ridiculing Sir Walter for being too class conscious. However later in the novel we see that whilst she does not approve of how class conscious Sir Walter is, Austen is still a woman of her time and we see that she is class conscious, through Anne's reactions, but not to the degree that Sir Walter is. In the same chapter we also find out more about Mr Elliot's past relationship with the Elliot family, in particular with Elizabeth and Sir Walter, to an extent. We see that Mr Elliot has disappointed her, â€Å"the heir presumptive †¦ had disappointed her† even though she had â€Å"found him extremely agreeable†. However instead of marrying Elizabeth, Mr Elliot sought independence and married â€Å"a rich woman of inferior birth.† This leads to all acquaintance between the ceasing as Mr Elliot had slighted Sir Walter and had â€Å"shewn himself as unsolicitous of being longer noticed by the family†. The next time we meet Mr Elliot is in the last chapter of Book One, where Anne and the Musgroves are in Lyme with Captain Wentworth. This chapter is where Mr Elliot sees Anne for the first time and where he is first seen as a potential rival for Anne's attention and affection, â€Å"Anne's face caught his eye, and he looked at her with a degree of earnest admiration†. Wentworth in turn notices how Mr Elliot looks at Anne and even he can â€Å"see something like Anne Elliot again†. Mr Elliot paying attention to Anne shows that se is once again in â€Å"bloom†. In this chapter through Anne and the others in Lyme that Mr Elliot is in mourning, therefore his wife has only died relatively recently. When the ‘mystery gentleman' is identified as Mr Elliot by the party in Lyme, we see that Austen highlights Mary's class snobbery. We next see Mr Elliot in Chapter Three of Book Two, however the reaction to him is much more positive than it was in the first book. We see that despite his previous grievances against them Elizabeth and Sir Walter readily forgive Mr Elliot and are even happy to renew their acquaintance. In this chapter we see that the relationship between Mr Elliot and Anne improves and we see that he is clearly attracted to her. This is where the possibility of Mr Elliot standing as a rival against Wentworth for Anne's affections becomes a reality. In the next chapter Austen uses Mr Elliot to show how fickle Lady Russell is. We see here that she feels that he could not be â€Å"a more agreeable or estimable man† and that â€Å"Everything united in him; good understanding, correct opinions, knowledge of the world, and a warm heart†. This directly contrast her feeling in Chapter Fourteen where she states that â€Å"he is a man whom [she has] no wish to see† and that he had â€Å"left a very strong impression in his disfavour† with her when he declined to be â€Å"on cordial terms with the head of his family†. Here we also see that Mr Elliot is not as class conscious as Sir Walter and Elizabeth but he is more class conscious than Anne. In the next chapters Mr Elliot becomes even more of an obstacle in Anne and Wentworth's relationship. We see what Anne's opinion of him is; she thinks that whilst â€Å"Mr Elliot is an exceedingly agreeable man† he was â€Å"too generally agreeable†. This shows how shrewd Anne is, compared with the rest of her family and her close friends. Austen uses Mr Elliot more in the second half of the novel in order to distract Anne's attention away from Wentworth. This can be seen in Chapter Twenty during the concert held for the benefit of a person patronised by Lady Dalrymple. We see that Mr Elliot successfully monopolises a lot of Anne's time, which in turn makes Wentworth jealous. Wentworth now knows that he is still in love with Anne due to the attention she is receiving from Mr Elliot, but again due to the obstacle Mr Elliot presents he can not make his feelings known to Anne. However after Mrs Smith unmasks Mr Elliot for Anne after the concert, we see him for who he truly is. Here Wentworth and Mr Elliot can be compared and you can clearly see who the better person is out of the two. Wentworth is everything that Mr Elliot is not, for example Wentworth is open and spontaneous whereas Mr Elliot is polished and conceals his emotions. Another example where the two can be compared is when Wentworth helps Mrs Smith when Mr Elliot deserted her in her time of need after the death of her husband. Here Austen clearly wants to show the differences between the two characters, and it highlights how Wentworth is from a lower class and has made his own fortune through hard work and how Mr Elliot stands to inherit his fortune whilst not even being half the man Wentworth is. In conclusion it could be said that Mr Elliot is of vital significance to the novel and that Austen uses him to further the plot, especially between Anne and Wentworth. He is used to show the characters and the readers that even though he is from the upper classes it does not mean that he is better than any one else. This brings up the theme of the changing ideal of the gentlemen in Persuasion. Austen also uses him throughout the novel in relation to the major themes, for example family as well as love.

Saturday, November 9, 2019

10 Latin Abbreviations You Might Be Using Incorrectly

10 Latin Abbreviations You Might Be Using Incorrectly 10 Latin Abbreviations You Might Be Using Incorrectly 10 Latin Abbreviations You Might Be Using Incorrectly By Mark Nichol Abbreviations deriving from Latin terms and phrases can be troublesome for us non-Latin speakers. Here’s the long and short of the most common short forms adopted into English from the classical language: 1. e.g. This abbreviation of exempli gratia (â€Å"for example†) is not only often left bereft of its periods (or styled eg.), it’s also frequently confused for a similar abbreviation you’ll find below. Use e.g. (followed by a comma) to signal sample examples. 2. etc. This sloppily formed abbreviation of et cetera (â€Å"and so forth†) is often misspelled ect., perhaps because we’re accustomed to words in which c precedes t, but not vice versa. (Curiously, Merriam-Webster spells out etcetera as such as a noun, but at the end of an incomplete list, retain the two-word form, or translate it.) A comma should precede it. Refrain from using etc. in an e.g. list; the abbreviations are essentially redundant, and note that etc. is also redundant in a phrase that includes including. 3. et al. This abbreviation of et alia (and others†), used almost exclusively to substitute for the names of all but the primary author in a reference to a multiauthor publication or article but occasionally applied in other contexts, should have no period after et, because that word in particular is not an abbreviation. Also, unlike as in the case of etc., refrain from preceding it with a comma, presumably because only one name precedes it. Fun fact: We use a form of the second word in this term alias to mean â€Å"otherwise known as† (adverb) or â€Å"an assumed name† (noun). 4. i.e. This abbreviation of id est (â€Å"that is†) is, like e.g., is frequently erroneously styled without periods (or as ie.). It, followed by a comma, precedes a clarification, as opposed to examples, which e.g. serves to introduce. 5. fl. This abbreviation of flourit (â€Å"flourished†) is used in association with a reference to a person’s heyday, often in lieu of a range of years denoting the person’s life span. 6. N.B. This abbreviation for nota bene (â€Å"note well†), easily replaced by the imperative note, is usually styled with uppercase letters and followed by a colon. 7. per cent. This British English abbreviation of per centum (â€Å"for each one hundred†) is now often (and in the United States always) spelled percent, as one word and without the period. 8. re This abbreviation, short for in re (â€Å"in the matter of†) and often followed by a colon, is often assumed to be an abbreviation for reply, especially in email message headers. 9. viz. This abbreviation of videlicet (â€Å"namely†), unlike e.g., precedes an appositive list one preceded by a reference to a class that the list completely constitutes: â€Å"Each symbol represents one of the four elements, viz. earth, air, fire, and water.† Note the absence of a following comma. 10. vs. This abbreviation of versus (â€Å"against†) is further abbreviated to v. in legal usage. Otherwise, the word is usually spelled out except in informal writing or in a jocular play on names of boxing or wrestling matches or titles of schlocky science fiction movies. (â€Å"In this title bout of Greed vs. Honesty, the underdog never stood a chance.†) Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Vocabulary category, check our popular posts, or choose a related post below:7 Types of Narrative ConflictHomogeneous vs. HeterogeneousPhrasal Verbs and Phrasal Nouns

Wednesday, November 6, 2019

Free Essays on The Environmental Effects of the High Dam at Aswan

INTRODUCTION: The livelihood and stability of Egypt `s population is directly linked to the Nile valley and delta. Although these two regions account for less then 5% of Egypt `s land surface (fig. 1), all its agriculture and water sources are concentrated in these areas (White 1988). The water sources for the Nile are the Blue Nile (originating at Ethiopian highland) and the White Nile (draining east central Africa and Sudan).The river flows through Egypt toward the Mediterranean sea, forming a delta at its south-east coast. Fig. 1 - The Nile path after building the Aswan high dam. (White 1988). Prior to the beginning of emplacement of barrage along the Nile in the last century, the river had a seasonally fluctuating fluvial regime (Hurst 1964). Its annually water discharge at the coast was above 8*1010 m3, caring about 10*108 tons of sediments (Eldardir 1994), and was the main sediment source for the east Mediterranean (Stanley and Wingerath 1996). At the end of the 19th century two major sediment bearing distributors were active (Damietta and Rosetta, fig. 2) (Stanley 1996). A series of barrages along the Nile (north of Aswan) were constructed during the 19th century regulating flow and navigation (Elassiouti 1983). At the beginning of the 20th century the first dam in Aswan, the low dam, was build. This dam was designed to generate hydroelectric power and, to decrease the seasonal fluctuations in the Nile flow (without carrying any water storage over from one year to another). Accordingly, it hasn't stored any significant amounts of Nile silt. During the 1950's the Egyptian government had to face a very high population grow rate (~3% a year). Given its limited resources of arable land in the Nile valley, Egypt was looking for opportunities to expand its agriculture, energy, and associated manufacturing production. The easiest alternative was to expand the irrigated areas and to inc... Free Essays on The Environmental Effects of the High Dam at Aswan Free Essays on The Environmental Effects of the High Dam at Aswan INTRODUCTION: The livelihood and stability of Egypt `s population is directly linked to the Nile valley and delta. Although these two regions account for less then 5% of Egypt `s land surface (fig. 1), all its agriculture and water sources are concentrated in these areas (White 1988). The water sources for the Nile are the Blue Nile (originating at Ethiopian highland) and the White Nile (draining east central Africa and Sudan).The river flows through Egypt toward the Mediterranean sea, forming a delta at its south-east coast. Fig. 1 - The Nile path after building the Aswan high dam. (White 1988). Prior to the beginning of emplacement of barrage along the Nile in the last century, the river had a seasonally fluctuating fluvial regime (Hurst 1964). Its annually water discharge at the coast was above 8*1010 m3, caring about 10*108 tons of sediments (Eldardir 1994), and was the main sediment source for the east Mediterranean (Stanley and Wingerath 1996). At the end of the 19th century two major sediment bearing distributors were active (Damietta and Rosetta, fig. 2) (Stanley 1996). A series of barrages along the Nile (north of Aswan) were constructed during the 19th century regulating flow and navigation (Elassiouti 1983). At the beginning of the 20th century the first dam in Aswan, the low dam, was build. This dam was designed to generate hydroelectric power and, to decrease the seasonal fluctuations in the Nile flow (without carrying any water storage over from one year to another). Accordingly, it hasn't stored any significant amounts of Nile silt. During the 1950's the Egyptian government had to face a very high population grow rate (~3% a year). Given its limited resources of arable land in the Nile valley, Egypt was looking for opportunities to expand its agriculture, energy, and associated manufacturing production. The easiest alternative was to expand the irrigated areas and to inc...

Monday, November 4, 2019

Management 380 Essay Example | Topics and Well Written Essays - 1000 words

Management 380 - Essay Example can founders and that considers itself a direct or an indirect part of America by identifying that ‘there is no difference between New York and Chennai since one can do the same work in both the cities’. In fact, they chose this country to make the people react like their partial slaves (training and recruiting programs) through the covert colonialism compared to the overt colonialism of Britishers. This manipulation and exploitation of Indian workers for personal gains and benefits (in the name of competitiveness and free market system) can’t be explained, justified and supported because it’s against the ethics principles of business. Secondly, Office Tigers have also been involved in taking the jobs away from American workers because their Outsourcing business and its marketing to other businesses of providing the work at cheaper rates compelled the American organizations to cut down their labour force that later resulted in mammoth job losses in America. So, it was also against the greater well-being of US workers and economy. Thirdly, the management says that managers must take care of societal values, standards and norms but Office Tigers adopted an open door policy in India by disregarding the traditional cast system and did not place any restrictions on employment of low caste workers. Theoretically, they violated the societal norm that says that an Upper Caste Hindu can not work with one from a lower caste but surprisingly this didn’t go against the firm’s long-run objectives. Chennai is the fourth largest city of India, an underdeveloped economy, where a great number of people are still deprived of basic living/health and quality (plus cheap) educational facilities (universities and higher education institutions) compared to United States, which is a developed economy, an industrialized nation and an economic super power where people have access to all basic necessities and they are not deprived of education. This difference among Indians and

Saturday, November 2, 2019

Statistics in Business Essay Example | Topics and Well Written Essays - 500 words

Statistics in Business - Essay Example When drawing inferences about a population, basically estimation and hypothesis testing is involved. Data may be quantitative or qualitative in nature. Qualitative data is data that is not numerical. Quantitative data on the other hand is numerical (involves numbers). Data can be measured in four levels: nominal, ordinal, interval and ratio (Anderson, Sweeney & Williams, 1994). The lowest of the four levels of data measurement is nominal and deals with labels, categories or names. Data that falls under the nominal level is usually qualitative. At this level, the data cannot be ordered and statistics can not be reasonably drawn from it. The second level of data measurement is ordinal. At this level, the data can only be ordered and ranked with no room to make meaning of the differences between the data. Data that can be ordered and in which sense can be made of their differences can be measured at the interval level. However, the data that falls in this category is known to have no starting point, examples being the Celsius and Fahrenheit scales used to measure temperature (Thompson, 2006). The highest level of data measurement is the ratio level. Data that falls in this category possesses all the characteristics of the interval level. In addition to these, the data has a zero value. Statistics plays an integral role in business decision making in the modern setup. In order to make sound business decisions, for example, an entrepreneur should have a good idea about the demand for their products. Based on statistics, the quality of products produced by a business may be verified (Anderson, Sweeney & Williams, 1994). Furthermore, statistical data may be used by managers to establish or evaluate customer satisfaction, evaluate risks, calculate loss or profit, and calculate financial ratios among other applications, all