Themes in the Crucible

Jacob Fallin Mrs. James English III 22 November 2010 Themes in The Crucible In my essay I’m going to be talking about the themes in The Crucible. â€Å"Saving your image is not worth the lives of innocent people. † Danforth did not want to postpone the hanging because he doesn’t want to look weak in Salem. So to look powerful he showed no mercy, didn’t not postpone the hangings, and so people with respect him in all ways. â€Å"Lies may be truth, and truth may be lies. † Said by John Proctor, innocent persons knew the truth while Abigail said that they were working with the devil.So who is going to believe who? That is what happens danforth does not believe the innocent, but the liers. â€Å"It’s better to fail with honor than succeed as a fraud. † John Proctor died knowing the truth while Abigail ran away from the innocent lives that she took from good people and she did that with her life of lies, and gets away from everything that h appened to all the innocent people that died for telling the truth and not doing witchcraft but was accused for it and then was hanged if did not confess.Jacob2 â€Å"When good men do nothing, evil can triumph. † If people in Salem said that Abigail and the other girls were lying they could have had a chance for the innocent to live. But only one person stood up for himself and the innocent [John Proctor] and he was hanged for not confessing to witchcraft which he was innocent but since he said â€Å"I am not with god. † â€Å"A lie told often enough becomes the truth. †Abigail and all the other girls, which said the same thing over and over again that was â€Å"so and so used witchcraft† and Judge Danforth believed Abigail and all the other girls which caused several death of innocent people like Corey Giles who was pressed to death they did that cause, so it soon became the truth to the court. Whoever was accused was going to get hanged unless the confe ssed and there were a few that did confess, and will be remembered by being known for doing witchcraft but the ones that didn’t confess were hanged, the last two people that hanged and did not confess was Rebecca Nurse ,and John Proctor. One error can lead up to many errors. † It all started because of Abigail and John's relationship, that’s when the witch trials and hangings occurred. All of this could have not started if John had not had the affair with Abigail and gave her hope that they would one day be together and she still though that john and her would soon be together because his wife was accused.

Apple iphone case study

Brand loyalty is incredible. People will lineup in the freezing cold overnight Just to Boone of the first to get their hands on the oenophile! (Gannett, 2012) From the anti-capitalism point of evidences like phone counts as luxuries. Thinking this kind of huge prices could be speedometer more vital. Employ high technologies. This frequencies features for at least two purposes. One, First degree price discrimination endow, luxury customer acquisitiveness's high technology along with hightail hardware component turn Philippine into very costly merchandise. Robbery many people cannot afford the price. Ease of use. Apple utilizes user friendliness elements for both hardware underwear parts of phone. 3. 5 mm audio Jack would be a good example! phone is equipped with own Apple sloganeering system, ISO. And APS which work with ISO can only be downloaded from Passport. Other rivals like Android have unmeritorious channels. 12 29 Former CEO, Steve Jobs' role in developmental and leading Apple to the marketability. Steve Jobs died on Cot 2011.We can still sissies works and ideas in Apple phone. His allocate be an excessive damage to the company. Having strategic agreements with well-known mobile carriers. Like T-Mobile and&T Apple summary of PESTLE Analysis Falsifications The supply and manufacture of many critical components is performed by sole- sourced outsourcing partners in the U. S. , Asia and Europe. Outsourcing partners in Asia perform final assembly of substantially all of the company's hardware products.Manufacturing or logistics in these locations or transit to functionalities may be disrupted for a variety of reasons including, but not limited, natural and man-made disasters, information technology system failures,military actions or economic, business, labor, environmental, public health, or Political issues. (APPLE INC. , 2012) interruptions have caused and could cause damage or disruption conversational commerce and the global economy, and thus could have a materialness effect on he Company, its suppliers, logistics providers, manufacturing vendors and customers, including channel partners.The Company's business operations are subject to interruption by natural disasters, fire, power shortages,nuclear power plant accidents, terrorist attacks, and other hostile acts, labor disputes, public health issues, and other events beyond its control. (APPLE INC. ,2012) Econometricians The global recession is having a serious impact on Apple's retail performance The follow-on effects from global economic conditions on the Compulsiveness's could affect the Company's ability to obtain componentsTherefore,the Company remains subject to significant risks of supply shortages and pregnancies. The Company expects to experience decreases in its gross margin percentage in future periods, as compared to levels achieved during 2012,argyle due to a higher mix of new and innovative products with flat or reduced pricing that have higher cost structures and de liver greater value to customers anticipated component cost and other cost increases.Future strengthening of the U. S. Dollar could also negatively impact gross margin. (APPLE INC. , 2012) 13 Social factors The Company's business requires it to use and store customer, employee, and business partner personally identifiable information (?PIE). This may include names, addresses, phone numbers, email addresses, contact, preferences, detoxification numbers, and payment account information.Although maliciousness's to gain access to PI affect many companies across various industries,the Company may be at a relatively greater risk of being targeted because of thighs profile and the amount of PI managed. (APPLE INC. , 2012) Declassifications $3. 4 billion for 2012 which is a crucial manner in Tuesdays competition (APPLE INC. , 2012) Environmentalists The Company also sells its hardware and software products to enterprise and government customers in each of its geographic segments.

Creating a Culture of Engagement Article Example | Topics and Well Written Essays - 500 words

Creating a Culture of Engagement - Article Example Workplace culture is reflected on how workers dress, the time they report to work, how their lunch break is spent and how they solve internal and external issues. Workplace culture unifies employees as they are allowed to form their opinions about the culture of a workplace. Involving employees unifies the entire organization including the management. Workplace culture starts at the top with the company owner and upper management. The unity makes employees feel like they are involved, and they are part of a team, making them more concerned for the success of the entire business, not just their individual accomplishments. Workplace culture increases marketability. Workplace culture is a part of the brand build for your business, and it will make an impact on how individuals are being hired and what type is attracted to the company. People seeking jobs tend to look for companies that fit their kind of lifestyles, for instance, flexible hours, casual dress codes, other work opportunities or companies with extra amenities like gyms. Companies with well-defined cultures are well recognized as better places to work, making them be known among prospective employees (Reid & Hubbell, 2005). A good understanding of a workplace culture improves productivity Workers who understand their workplace culture have a better understanding of their goals and often fulfil the needs of their managers, fellow employees and customers. Theyre invested in their work and demonstrate loyalty. Employees who work for companies with healthy workplace cultures may be more productive in their work. Training the employees in the workplace enables them to gain the knowledge that is required for them to grow. This program will lead to the increase in team spirit between workers and supervisors leading to the improvement of retention rates. The correlation between workplace culture and organization commitment has been very

Micro Economic Principles Assignment Example | Topics and Well Written Essays - 1500 words

Micro Economic Principles - Assignment Example Therefore, according to Adam Smith, absolute cost difference provides the basis for international trade. (In this example labour hour is taken to be the only resource of production.) David Ricardo had later extended the above said idea by pointing out that it is comparative advantage and not absolute advantage that forms the basis of international trade. COUNTRIES CLOTHING (labour hours per unit) FOOD (labour hour per unit) RELATIVE COSTS (C/F) RELATIVE COSTS (F/C) U.S. 8 hours/unit 10 hours/unit 0.8 hours/unit 1.25 hours/unit INDIA 10 hours/unit 15 hours/unit 0.67 hours/unit 1.5 hours/unit Here, it can be seen that India has an inferior productivity compared to U.S. in both the goods. In the absence of trade both the nations will have to produce both the goods in order to meet the local demands. But, in the presence of trade, India should produce only clothing as it has a lower opportunity cost. Again, U.S. should specialize in food because here food has a lower opportunity cost. Op portunity cost is the cost incurred when a choice is made, in terms of the next best available option. In the above stated example, India by producing 1 unit of Clothing is losing out on 0.67 units of food but if India were to produce food, then by producing 1 unit of food, India would have lost out on 1.5 units of clothing. Therefore, a country should specialize in a good that has a lower opportunity cost. Considering 100 hours of labour, the figure below shows the gains from trade: For U.S., For India, Production possibility frontier or the production possibility curve is a curve representing the tradeoff between two commodities given the resources is efficiently utilized. The PPC shows the maximum amount of one commodity that can be obtained given fixed amount of second commodity. Terms of trade is (price of exports)/ (price of imports). It is the quantity imports which can be purchased using a certain fixed amount of exports. Trade line is the line representing the terms of trad e. Gains from trade are the gains that result from specialization and trade arrangements between two countries. In this example, both U.S. and India are gaining from this arrangement. The price of food post trade will be between 1.25-1.50 and the price for clothing will be between 0.67-0.80. This proves that trade will be beneficial for both the countries. (Pugel, n.d.; Krugman, 2007) Answer 2. a) Given, MPC= 10+10Q P= 70 – 5Q The private market equilibrium will have the MPC = P or, 10+ 10Q = 70 -5Q or, 15Q= 60 therefore, Q’ = 4 substituting the value of Q in the demand equation we get, P = 70 – 5*(4) or, P’ = 50. b) Given, MSC= 10 + 12Q P= 70 -5Q The social market equilibrium will have the MSC = P or, 10 + 12Q = 70 – 5Q or, 17Q = 60 therefore Q*= 3.53 (approx) [socially optimum Q] substituting the value of Q in the demand equation we get, P= 70 -5*(3.53) or, P*= 52.35 [socially optimum P] (Varian, 2010) The equilibrium in (a) is not optimal becaus e in case of negative externalities, marginal social cost > marginal private cost. The diagram above shows that for a profit maximizing producer, for a given cost, the profit maximizing output is Q’ which is greater than the socially optimum output Q*. By producing at Q’, the producer is causing an externality worth AB which the producer is not treating as a cost. (Varian, 2010) The equilibrium in (b) is optimal because here the cost of externality is also

What are the challenges associated with introducing e-learning within Essay

What are the challenges associated with introducing e-learning within organisations - Essay Example The availability and the ease of access to the web-based resources have added new dimensions to corporate training. Companies have been forced to adapt to the constantly and rapidly changing world. Global trade and marketing environment require change but change erodes control and prevents the establishment of status quo. The production processes and the marketing technique need to be replaced. Companies who innovate will survive. The pace at which technology is changing is overwhelming and it is essential to mould the employees accordingly or lose out. The type of training, the pace and the means of training have all undergone a change (Byers, 2005). The new sources now compel an organization to embrace e-learning which implies new ways to support and deliver training. E-learning also known as computer-based learning or online distance educations refers to the structured, computer enabled learning carried out by individuals or groups over the internet or internal network (Isoph, 200 4). E-learning delivers just-in-time training for people when they need it (Sullivan, 2002). E-learning delivers efficient solutions to developing the staff and keeping them abreast of new trends and technologies; it allows on-the-job and self-paced training. E-learning materials can be regularly updated and published immediately. E-learning provides a variety of components that together make up a total learning solution – inbuilt tests allows the employees to test their own skills; learning management systems (LMS) enables them and their managers to track their progress (E-learning Forge, 2007). Nevertheless, managers and instructors are facing new challenges in planning e-learning. Project managers need to consider and design multi-level alignments, identify and satisfy the stakeholders involved in all phases of the instructional design process and attend the principles suggested in the literature (Villachia et al., 2004 cited by Byers, 2005). Any

Corporate startegy Essay Example | Topics and Well Written Essays - 2500 words - 1

Corporate startegy - Essay Example Cookson group plc notable has enhanced its strategic position which put the company forward as a competitive in the industry. The company business model and strategies takes into account the changing corporate environment and the systematic realization of the underlying positioning. The company has achieved this through devise of a desired position in the future based on the foreseeable and present developments as well as strategizing to realize this positioning. Focus and emphasis is laid on the company continuity and the determination of character and contents of the organization activities. The company strategic position is underpinned on several aspects including leading global markets positions in its industry and development of market exposure to increase revenue and profits. Others include enhanced technology, increased R&D capability, acquisitions, strong cash flow momentum and expansion into international markets. Cookson group plc has two main divisions in its business model which are Performance material section and Engineering Ceramics where it operates under Alent PLC and Vesuvious PLC respectively. These divisions facilitate in supplying specialist consumable materials and chemicals in industrial production processes. It is notable that both divisions have adopted the same business model and the way operations are carried out. The company notably sells its products based on added value as opposed to just price (Cookson Group Plc 2006). Cookson group plc also focuses on sustaining and maintaining strong financial position enhancing support on its businesses in the divisions. This business model strives to achieve this through enhanced long-term financing arrangements with ample liquidity and low leverage headroom. Cookson business model and strategy can be summarized as follows:- This analysis involves study on the corporate environment that the company operates so as to

Human Sexuality Essay Example | Topics and Well Written Essays - 2500 words - 1

Human Sexuality - Essay Example Others are confident that homosexuality contradicts the basic laws of nature. However, more often, such misunderstanding is due to the lack of scientific knowledge and theories regarding the development of sexual orientation in humans. The findings of contemporary research in human sexuality are at least controversial. Whether the orientation is the product of genetic of social influences is difficult to define: the current scientific knowledge does not provide an answer to this question. However, based on everything that has been written and said about the issue under consideration so far, the development of sexual orientation is a complex process that combines the features of genetic and social influences. Contemporary science treats sexual orientation as one of the most popular topics of scholarly research, and the issue of human sexuality is often reconsidered from the different philosophic viewpoints. Today, essentialism and social constructivism are fairly regarded as the two principal perspectives in the analysis of sexual orientation development. If we turn to essentialism, we will find out that the orientation, as well as sexuality, in general, as rooted in intrinsic, biological processes. Put simply, sexual orientation, including homosexuality, is the critical feature of the human nature and is an essential element of the human genetic structure. In their philosophic arguments, essentialists primarily apply to the principles of the evolutionary theory, and claim that â€Å"both human sexuality and sexual orientation are coded in human genes; essentialists also claim that throughout the human history, genes promoted reproduction and survival of humans†.

Compare and contrast three companies Research Paper

Compare and contrast three companies - Research Paper Example The services and products include software, online advertising technologies, search and cloud computing. On the other hand, Apple Company specializes in the production of computers and computer-related devices such as software and mobile smartphones. Apple Incorporation designs iPads, Macs (personal computers), iPhones, iPads and various versions of operating systems such as OS X, iLife and iWork. With a current market cap of $105 billion, Apple is slightly behind Intel and ahead of Dell. iPods sold by the company account for over two-thirds of the MP3 player market (Kahney 1). The three companies not only share a host of similarities but also exhibit a range of differences. The two companies; Google and Semco, share a similarity in the degree of freedom given to employees in order to design or influence the end products of production. The engineers working at Google have significant independence in terms of the types of projects they chose to work on. The engineers are encouraged to allocate up to a maximum of 20 percent of weekly working schedule time to the pursuit of personal software ideas. Records indicate that the products, Google News and Gmail first came out as individual endeavors of Google’s employees (Kahney 2). On the other hand, Semco has eliminated the aspect of using time clocks in management. The employees operating on the factory floor enjoy the freedom of coming to work and leaving when they feel like doing so. The management of Semco makes the assumption that all the employees are trustworthy adults and as such, do not need direct supervision on time-keeping. It is unbelievable that the employees could come to the factory every morning and fail to get down to work as expected by the management (Semler 6). The expected observation by the very management (counselors) is that the workers would eventually start coordinating the working-hours scheduling by themselves. The workers have freedom to the extent that, upon achieving the set

Censorship v Pornography Essay Example for Free

Censorship v Pornography Essay 1.0  Ã‚   Introduction:   Ã‚  Ã‚  Ã‚  Ã‚   This paper seeks to determine whether there is basis to use censorship to deal with pornography, based on critical assessment of the feminist debates about the issue.   In addition, an examination on how pornography is made similar to prostitution, drugs, and other marginal crimes will be analyzed given its roots in moral judgments and the ambiguous nature of its harms. Knowing the possible harms that are associated with pornography and the reasons for the need for its regulation will also form part of the analysis with the end view of evaluating whether censorship is the solution to pornography.    Analysis and Discussion 2.1 What is pornography?   Ã‚  Ã‚  Ã‚     To understand pornography, there is a need to look at it from its background up to present times.   Webb (1995) attempted to study more profoundly by looking back at the sexual practices that have been depicted in many cultures, from Greek, and Roman to Chinese and Japanese, for centuries. She found that the term pornography was just used to describe some of these depictions in much recent times. She explained that the term arose together with certain aspects of the tyrannical sexual morality developed by the capitalist ruling class during the 19th century.  Ã‚   She blamed the polarization of the Victorian period which caused dividing the line on what was â€Å"respectable† and what was not between women’s groups (Webb, 1995).   Ã‚  Ã‚  Ã‚   The basis of this respectability was related to the ‘dangers’ of female sexuality and its regulation and that women were required into an inflexible duality. Women were therefore categorized into â€Å"good† women who were asexual, â€Å"chaste’ before they have their marriage and â€Å"pure† after.   Thus, Webb argued that sex was only necessary for reproduction not pleasure, and the consequence was to confine the same to married heterosexual couples.   As a result, women that were found to have sexual activities outside this unbending rule were condemned and which ultimately led to prostitution (Webb, 1995).      Ã‚  Ã‚  Ã‚  The issue of pornography was felt more in the some countries than others. Webb (1995) cited about the laws of pornography and obscenity in England and the US which covered much more than others as censorship in there is extended to the production, sale, and possession or transacting of written and graphic sexual material.   The issue even went as far as banning contraceptive or abortion drugs, devices and information; and making it a crime to have homosexual behavior between consenting male adults. The result of these prohibitions was also to give police greater summary power over working class women and children because of threat of charging women and children the violation of the laws which may not be obviously be made to men (Webb, 1995).   Ã‚     Ã‚  Ã‚  The notion of pornography cannot be detached from its forms of art access to which was restricted to capitalistic men claiming to have some sort of academic interest.   As such censorship was directed only against   women, children and working-class men that resulted to discrimination.   The limitation or restriction to access to pornography limited occasions for questioning the supposed to be proper values for sexuality, for women and for the family. Webb (1995) explained that the practice had the effect of the having and philosophy reinforcing the family system, which was understood to be the basic unit of capitalist society.      Ã‚  Ã‚  Ã‚  Ã‚  The effect of this practice is to limit women into the private area of the home and their domestic labor. This caused these women not to create commodities for sale on the market.   Getting unpaid for their work at home, feminists believe that this resulted to their economic reliance upon fathers and or husbands as further toughened by their limited access to education and properly paid work. If ever they get employed they will eventually be paid the lower rate. They also lost control over their fertility and expression of sexuality. To make matters   worse, society has criminalized violation of pornography and this has affected the women even more. Sexual freedom was therefore curtailed during the 19th century (Webb, 1995).   2.1.1 Defining pornography and its problems   Ã‚     Ã‚  Ã‚  Ã‚  The dramatic change that has happened with pornography since the term was first used in the 19th century is just simply obvious.   Webb (1995) explained that during that time there was nothing about what is scientific, medical, artistic or popular context to be exempted from the liability for violating pornography.   It was only by the 20th century pornography when exemption could be had from pornography on the claim of being scientific or artistic merit.   Pornography then was defined under the general line as something that is produced for the purpose of producing sexual arousal, having no other â€Å"redeeming† feature. This is based on the assumption that to set out intentionally to produce sexual arousal is dreadful but if the main objective of the work is scientific or artistic, and the possibility of sexual arousal is only incidental, then these higher purpose may excuse the publication (Webb, 1995).   Ã‚     Ã‚  Ã‚  Given therefore the definition of the pornography, it would mean that pornography is relative to the eye of the viewer and in which, case it becomes an evil and not an art for those who cannot explain that is an art or not scientific to those who are uneducated.   Ã‚     Ã‚  Ã‚  Thus pornography could be defined in terms of suppression and containment of sexuality and sexual arousal which confuse things. Webb (1995) argued that images of sexuality can be positive and affirming and she cited the case of many lesbian and gay male definitions and positive images of their sexuality that have played an important part in their fight for democratic right and against persecution. She put in parallel that feminism had similarly redefined gender roles of masculinity and femininity, sexuality, and sensuality by using positive views and affirmations of choice and experimentation rather than passivity and submissiveness. By so having positive affirmations, sexual terms like what is erotic and what is pornographic could be delineated when properly debated upon and tested out so as to challenge the   old morality where it was defined by olden times that sexuality itself is hazardous and perilous to women (Webb, 1995)   Ã‚  Ã‚  Ã‚  Ã‚     What can be seen therefore is a confusion as to proper definition of   pornography and its propriety of defining as such would seem to depend on less number of who are against it or lack of sufficient number of those show can express themselves that pornography is not evil to them. If such is the case, it would seem that level of maturity in terms on moral belief is something that other people or the state can dictate upon the members of the community especially the women although the latter are already in their adulthood.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   To purpose of pornography definition is only required if one is to make a law about pornography but as admitted by Kuhn (1988) pornography is â€Å"social construct†¦ subject to historical variations.†Ã‚   It could therefore be established that pornography is a   matter of culture where morality is relative. What is erotic to one culture may be pornographic to others (Webb, 1995). 2.2 What is censorship?   Ã‚     Ã‚  Ã‚  Ã‚  There are two views on the matter of censorship. There are those who are against and there are those who favor (Rodgerson and Wilson, 1991) of its use to control pornography. While both views espouse the causes how to promote women’s rights, their approaches how to fight for their causes are different. Webb (1995) cited feminists groups like Dworkin and MacKinnon who elevated the abolition of pornography to a strategy for liberating women. Dworkin (1981) stated that pornography is the belief that could explain all forms of women’s oppression and hence she espoused banning the same. The choice to ban pornography to liberate women is based on the view that women’s repression is caused by the power of an inherently female sexuality.   It assumes that all men are dormant rapist, in the making to be activated by pornography. Thus it was said that pornography is the theory and rape is the practice (Webb, 1995).      Ã‚  Ã‚  Ã‚  The proponents’ assumption that men are rapist waiting to be activated by pornography could not be said to be already established. Thus on the basis of the great probability of wrong assumption, pornography then could not just be solved by censorship.   Until scientific evidence therefore is established what is assumed could be validated empirically, it is really very dangerous to make such an assumption since laws that would be passed would not have also logical if not substantial basis to actually address the issue of pornography correctly.   Ã‚  Ã‚  Ã‚     Ã‚  Expressing disagreement on the assumption about men in the banning pornography, Webb (1995) explained that this is a biological determinist view that does not allow much scope for women’s liberation but rather it was more an attempt by individual women to totally separate themselves from any likely contact with men.   She argued that if all men are inherently oppressors of all women then women may just as well give up struggling now (Webb, 1995). She therefore saw the wrongness of the assumption that men are presumed rapist.   She argued that although people are socially conditioned to behave in certain ways, those who espouse the belief that men are presumed rapist, necessarily disregard the very important element of self-consciousness, reflective and reasoning power, and emotional response. Citing contradiction with scientific evidence, Webb (1995) asserted that to see men as programmed for violence not only endorses the most conservative view of human nature, it also absolves men of any responsibility for their actions.   Ã‚  Ã‚  Ã‚     The argument that men are programmed or conditioned to rape of women absolves men of responsibility is tenable because it presupposes the absence of choice or freedom which is an element in crimes or statute violation of statutes.   Freedom of choice is necessary to hold one accountable but to impose the belief that men are programmed to act would defeat the very purpose of defining crime where there is an assumption   that men are waiting women to rape after reading the so called â€Å"pornographic† materials.   Ã‚     Ã‚  Coward (1982) supported this latter view when she attacked the view of an inherent aggressive male sexuality.   Coward reminded that the view implies that any expression of male sexuality will be oppressive to women.   Thus she argued like Webb that the fight must be given up as women should withdraw from any public, or even private, exploration of sexuality in order to avoid male manipulation (Webb, 1995).   Ã‚  Ã‚  Ã‚   To argue therefore that censorship is the solution to violence against women is mixing up violent images and violent acts. Portrayal of rape and rape itself are obviously different although connection could be noticed.   Since the two are not identical, it is wrong to treat them the same way. Censorship or banning a description or picture of a violent act is not dealing on the act itself or its causes.  Ã‚  Ã‚   Banning was based on the wrong assumption and the wrong premise.   To equate a picture with the actual act would be missing the point by really confusing the issue that would amount to an overkill and it has the effect of portraying that man is really evil waiting to rape women. Doing this, however, would violate the right to freedom of expression, which is one of the inherent rights of the individuals. It is difficult to imagine how would one testifying in court who was a victim of rape, to tell people of the bad experience without at least using some depiction or illustration. It would be hard too for investigators to gather evidence if they cannot even take a picture of the crime scene involving rape victim if the latter act would be equated with the act of raping. How about the courts, will they be charged for pornography for trying supposedly pornography violations because of the depiction of sexuality made in the course of the trial?   The argument to equate depiction to the actual is simply absurd. 2.3 The feminist debates about the issue of pornography.   Ã‚     Ã‚  Ã‚  The debates of feminists about the issue of pornography have something to do with addressing the issue of sexism and the proper approach to solve the same.   Webb (1995) argued that sexual images can be both positive and negative. She explained that images can challenge the old stereotypes of women as passive and sexuality as dangerous, by presenting instead erotic imagery of women’s sexuality as pleasurable and active. She presented that pornographic images can also represent violence, abuse and degradation.      Ã‚  Ã‚  Ã‚  Finding the way on how to deal with the two sides of sexuality and its imagery in today’s society is the crux of the issue among feminist. Hence censorship is a controversial issue among feminist as it seems to be the most noticeable solution offered on the table by those in power to solve pornography. Answering therefore whether censorship of pornography is the most effective strategy or whether it only deals with the images and not the acts of violence directed against women is an interesting question to feminists. It is also asked whether implementing censorship could sweep away positive explorations of sexuality through the imposition of a new repressive morality. Will censorship liberate women is also an issue by these feminists (Webb, 1995).      Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Webb (1995) explained that fact women had won many parts gains over the last two decades and these have generated a higher consciousness of sexism, especially among young women.   She admitted that while many of these gains are now under attack, women of today have more choices and have expectations as a result of their liberalization as compared with the past (Webb, 1995).   That women now can expect going university, getting a job and receiving equal pay as against the absence of these about three decades ago must indeed be strong indications of   greater rights for these women. 2.4 The depiction of women in all areas of lives   Ã‚  Ã‚  Ã‚   Confronting the portrayal of women in all areas of their lives is a battle that feminists must fight. Webb (1995) brought out the fact the women are never absent from the magazines or TV programs, newspapers, or from advertising that uses sex and women’s bodies to sell products.   She added that at the same time   society seemed to be obsessed with sex, exploring our sexuality, especially for women, is actively repressed. She noted an example done 1992, where the federal government banned the distribution of a diary, the Fact and Fantasy File Diary that was produced by the Family Planning Association to provide information to young people on sexuality and sexual health (Webb, 1995). She argued that   banning the publication of these materials on the ground of being pornographic is just skirting around the problem of sexism (Webb, 1995). 2.5 How is pornography similar to prostitution, drugs, and other marginal crimes?   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Pornography cannot be similar to prostitution, drugs and other marginal crimes since banning the pornography actually violates freedom from expression and banning the same creates more harm. The harms that are associated with pornography as described by those who are supporting censorship may have no basis at all and there is not reason to equate depiction of rape with actual rape.   There is no known research that would show that is a great correlation between the number of read pornographic materials and crime committed in relation to sexuality as a result. Although this was what was propagated by those who support censorship, the US Supreme Court has spoken that the ordinance to implement banning of pornographic materials violates freedom of speech. It would appear therefore that if any forthcoming or existing law on pornography if there is any could be rightfully challenged in the Supreme Court for the latter to declare it unconstitutional.   An unconstitutional law, code or ordinance would produce no effect of therefore would confer no right on the part of enforcers to arrest violators and no obligation on the part of the supposed subjects would be expected. 2.6 What are the possible harms that are associated with pornography?   Ã‚  Ã‚  Ã‚   The possible harms that are associated with pornography include the possible sexual abuses against children and women as a result of failure to regulate the same. The claims of those who support censorship could be numerous because of the attempt to equate depiction of the act to the actual act but as argued earlier depiction is different from the actual act. Therefore for the purpose of this paper said feared harms are not given emphasis since there in scientific basis to substantiate the presence of actual harms in pornography that should be addressed properly by the enactment of laws that would penalize its violations. 2.7 What are the reasons for its regulation?      Ã‚  Ã‚  Ã‚  The reason for the regulation of pornography is to prevent the possible abuses that could be committed as a result of misguided use of information. The fact that it should be regulated and not banned appears to be the more responsive solution to the problem.   It is for this reason that movies should not be banned but rather reclassified to suit proper audiences and in the implementation of who could watch certain films is a matter of regulation and not censorship. 2.8 Is censorship effective in dealing with pornography?      Ã‚  Ã‚  Ã‚  Given therefore the background of pornography, one could just wonder whether the problem is properly defined. If not properly defined, would it be correct then to have censorship as the solution? The correctness therefore of the solution to pornography would depend on the validity of the assumptions that were made.   By this paper not having seen any evidence that would validate the assumptions made, it could not easily accept censorship as a solution.   Ã‚  Ã‚     In relation whether censorship is the solution, Webb (1995) said making a law on pornography â€Å"throws up the dilemma of the producer’s intent as opposes to the consumer’s response.† Thus she cited an illustration where an author or painter may intend his or her work to be erotic or a form of social commentary but another person may view it as pornographic. As proof, the novel entitled Mercy written by Dworkin (1990) was itself attacked as one to be graphically describing the continuous rape, torture and humiliation of the main character in the novel (Webb, 1995). Dworkin was in effect contradicting herself in this respect as she espousing censorship of any depiction but her novel violates the rules that she is fighting for.      Ã‚  Ã‚  Ã‚  Given the attack on Dworkin’s work,   it can be assumed that the   intent was to expose violence against women, not that it be read for sexual excitement but as Webb (1995) said,  Ã‚   Dworkin’s novel is exactly the sort of material that could be banned under the laws she herself proposes.   What does this mean then?   The supposed way of Dworkin to reach her audience in writing the book had to use some languages that could be understood to portray sexual imagination   or depiction and if evaluated on the standard of what is obscene then such work should also considered obscene. One may argue that Dworkin may be just trying to explain what is pornographic. Precisely, that is what is meant by the difficultly of just describing anything about sex to be pornographic without really having to say or use the words related to its definition (Webb, 1995).   Ã‚  Ã‚     Ã‚  Perhaps being moved by anti-pornography authors’ beliefs, supporters of censorship that include Andrea Dworkin and Catherine MacKinnon, sometime in 1983, drafted an ordinance passed by the Minneapolis City Council to give women the right to bring to court producers, distributors, sellers and/or exhibitors of pornography once these people feel being harmed by the material.   Ã‚  The ordinance was however disapproved by the mayor (Webb, 1995).   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚     A revised version of this legislation was passed by the Indianapolis City Council,   but was also unsuccessful after having been declared unconstitutional by the US Supreme Court on the ground of freedom of speech violation (Webb, 1995). The Supreme Court’s having declared the ordinance unconstitutional could only mean that the power of freedom of speech is paramount that to publicize it to educate people and letting them to   express themselves to discover what really are good and bad for them is an inherent human right. It is not the publication that is bad but it is the act of person who will act on the basis of whatever one senses using his or her power of perception. On the other extreme, a rapist need not see a picture to rape a woman whom that man has decided to rape. The evil of something should still depend on the freedom of a man to act on what one sees or hears and not necessarily be coming from the so called â€Å"pornographic† materials.   Ã‚  Ã‚     Ã‚   A position taken by those favoring censorship where pornography is defined within the explicit images of degradation and violence against women, has actually moved for more power through legislations (Webb, 1995).   As proof, Minneapolis Ordinance had that pornography is â€Å"the sexually explicit subordination of women, graphically depicted whether in pictures or in words†¦ women are presented dehumanized as sexual objects, things or commodities†¦who enjoy pain or humiliation.. in postures of sexual submission†¦ reduced to body parts† (Kelly, 1988, pp. 54-55). It is very clear from the definition that mere depiction is already a violation in pornography.   Ã‚  Ã‚     Ã‚  Ã‚  A major problem with the said law is that, although feminists may know what is degrading and dehumanizing to women, it is not the feminists who will make the decision in court.   It is the judges who are dominated by men who have the power to define what is sexually moral and what is not.   This is a reality that must be accepted.   Webb (1995) cited a Canada court case where a reinterpretation of existing obscenity law along the lines of the Dworkin/MacKinnon ordinance, was used to forbid the lesbian magazine Bad Attitude and caused the raid of a lesbian and gay bookshop.   Ã‚  Ã‚  Ã‚   The other side of the issue therefore does not go for censorship as the solution for the simple reason that the act of banning will not put a stop to pornography. Thus to campaign for censorship is obviously not just. Pornography could not therefore be equated to prostitution (Arcand and Grady,1993), drugs and other marginal crimes for they belong to different realms. The first is just depiction or portrayal of acts while the latter are actual acts. No wonder attempts to make an ordinance that would prohibit the same by groups espousing censorship ended with being vetoed by a mayor and another attempt to revise the same ordinance resulted to be struck as unconstitutional by the US Supreme Court.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   There are however still harms (Stark ,1997; Lottes et. al. Weller ,1993) that could be associated with pornography for which reason it should still be regulated by having selective banning especially to children who may not have the mental capacity to understand things while they are young. But as they mature an education that would help them understand about sexuality should be taught to them rather than resorting to complete censorship.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   When these children become adults it could not be assumed that they do not know how to practice their freedom of choice and intellect in being morally responsible for their acts. If indeed pornography may be defined where women are depicted to be dehumanized sexual objects, then by all mean censorship appears to not the logical solution but rather it should be the proper education of people how should humans behave using said natural sexuality given to them.   Ã‚  Ã‚  Ã‚  Ã‚   One argument that is forwarded by those who espouse censorship is that pornography is big business (Alexander, M., 2002) therefore banning it will interrupt on capitalism’s ability to make profit from the oppression of women.   Although pornography is admitted as a big business, it does not follow that it will not be sold if banned since capitalism has unremittingly created new needs and wants to exploit the economic concept of unsatisfied needs and wants. Business could always come up with a variation of projecting sex even in toys or internet games as sexuality will always be a part of the lives of humans.   Ã‚  Ã‚  Ã‚  Ã‚   It is therefore explaining to people about the implications of wrong use of sexuality and how they benefit from controlling the same that would be the better solution than completely stopping by prohibiting its depiction. Banning does not stop pornography, for it will just push it into the underground that would in effect come out in some other ways. The same shortsighted solution has the effect of also banning it as topic for public discussion and as venue to have constructive sexual alternatives.   Ã‚  Ã‚  Ã‚     Ã‚  Censorship of pornography has been the topic from many countries but it would seem that no law has been successful in actually stopping pornography.   The moment a law is made to censor pornography, people’s need to understand the subject or to engage in any form has its own way of coming out in number of ways.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   To oppose censorship should not be taken as condoning, ignoring or deprioritizing campaigns about the often aggressive and usually misogynist depiction of women in a society where capitalism has no sign of waning. Webb (1995) explained stated that women have a duty to be counted in the most effectual how to do away with images which are oppressive and sexist. These women should not seek to have pornography banned, but by starting a much more comprehensive debate about sex.   Ã‚  Ã‚  Ã‚  Ã‚   The same objective could also be attained by   campaigning for better sex education in different schools at different levels. Their minds should be opened to knowledge rather than deny then them capacity to be aware of the issues that would allow them to exercise their freedom to choose. By making people more aware of their sexuality,   there is a greater chance to create more informed and responsible behavior as well as social attitudes that would allow free expression of sexuality would more within the reach of these women. Conclusion   Ã‚  Ã‚  Ã‚  Ã‚   It can be concluded that the concept of pornography appears to have its roots in the past that resulted into grouping women into categories on who are â€Å"good† ,who are â€Å"chaste’ and who are pure. Being felt more in some than other countries, pornography is closely related to relativity of morality in different places. Where there are more prohibitions, the greater are the effects on the power of those who are to enforce the law against the would-be subjects like the children, working class women and working-class men. It therefore has is links with the concept of equality especially among women where the concept dawned on them as a way of discriminating them as against men who are not subject to said prohibition or censorship.      Ã‚  Ã‚  As could be expected based on it relativity characteristic, definitions of pornography could vary for different states or jurisdictions. Since the purpose of defining the same is for the authority to regulate or to prohibit the same, the problems could differ and whoever will be included as subjects in the said law will naturally be subject to its power and possible abuse by those who will implement the law. It could therefore be in terms of the suppression, containment of sexuality and sexual arousal depending on whose point of view, that the term could be defined. This therefore produces the effect of massive confusion.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Being therefore called a social construct, the concept of pornography depends at different times (Moon, R. 2000), so what to some is erotic is already pornographic to others.  Ã‚  Ã‚   To argue therefore for censorship is to argue to stopping the same in different ways depending on how pornography was defined.   Certain feminists like Dworkin and MacKinnon supported the abolition of pornography as a way to free women. This strategy necessary takes the view that women’s repression is caused by the power of an inherently female sexuality. With the assumption that all men are dormant rapists, who are in the making to be activated by pornography, one could already infer the possible consequences of making such an assumption. Thus a point in time was necessarily arrived at where the depiction of an act was already being equated with the act.   Ã‚  Ã‚     The other side of the coin argues that to make the dangerous assumption about men that they are prone to raping which calls for banning pornography will not necessarily result in women liberation as espoused by Dworkin’s group. To sustain the assumption about men as inherently oppressors of all women would amount advising to just give up struggling now as this has the effect of removing from the men the responsibility for their acts. This therefore is clearly oppressive to women.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   It should therefore be understandable to put one’s shoes with those of women as to the feminist debates about the issue of pornography because of the deep repercussions of their agreement or disagreement of laws that will define pornography and that will stop the same. Notable is the fact the mere prohibition of image depiction can make the old stereotype of women as passive and sexuality as dangerous. Censorship therefore is not the answer with the problem that was imperfectly defined, education is.   Ã‚  Ã‚  Ã‚  Ã‚   Simple regulation is therefore recommended rather censorship. Regulation of course extends to limiting access to children of some materials while they do not understand the issues clearly.   People should rather have a debate about sex or that they should be a campaign for better sex education in schools, or a   more informed and responsible social attitudes to expression of sexuality should be made possible.   By so doing people are presumed intelligent and free and enhancing the same through education would make their lives more meaningful.   More meaningful lives of course would mean better society and better society should mean fewer crimes as people would become more responsible of their choices. Bibliography: Alexander, M. (2002)   The First Amendment and Problems of Political Viability: The Case of Internet Pornography; Harvard Journal of Law Public Policy, Vol. 25 Arcand and Grady (1993) The Jaguar and the Anteater: Pornography Degree Zero; Verso Campbell, J. (1988), â€Å"Pornography Is it a Feminist Issue?, â€Å" Australian Feminist Studies, No. 7 Coward, (1982) R. â€Å"Sexual Violence and Sexuality,† Feminist Review, No. 11 Dworkin, A (1990), Mercy, Secker Warburg, London Dworkin, A, (1981), Pornography: Men Possessing Women, Women’s Press London Kelly, L., â€Å"The US Ordinances: Feminism and Censorship Prism Press, Great Britain, 1988† Kuhn, A. (1988), quoted in Campbell   (1988), â€Å"Pornography Is it a Feminist Issue?, â€Å" Australian Feminist Studies, No. 7 Lottes et. al. Weller (1993) Reactions to Pornography on a College Campus: For or Against?; Sex Roles: A Journal of Research, Vol. 29 Moon, R. (2000) The Constitutional Protection of Freedom of, University of Toronto Press Rodgerson Wilson (1991) Pornography and Feminism – the Case Against Censorship, Lawrence Wishart Ltd. , London Stark   (1997) Is Pornography an Action?: The Causal vs. the Conceptual View of Pornographys Harm ; Social Theory and Practice, Vol. 23 Webb, E. (1995) Pornography and Censorship: Silence or choice?, {www document} URL,   http://www

Typhoid Fever Signs, Symptoms and Treatments

Typhoid Fever Signs, Symptoms and Treatments Name of disease: Typhoid Fever 1. Aetiology: Typhoid fever, otherwise known as enteric fever, is a potentially fatal multisystemic illness caused primarily by Salmonella typhi. S typhi has been a major human pathogen for thousands of years, thriving in conditions of poor sanitation, crowding, and social chaos. It might have been responsible for the Great Plague of Athens at the end of the Peloponnesian War. The name S typhi is derived from the ancient Greek typhos, an ethereal smoke or cloud that was believed to cause disease and madness. In the advanced stages of typhoid fever, the patients level of consciousness is truly clouded. Although antibiotics have markedly reduced the frequency of typhoid fever in the developed world, it remains endemic in developing countries. This large genus of gram-negative bacilli within the family Enterobacteriaceae consists of two species: S. enterica, which contains six subspecies, and S. bongori. S. enterica subspecies I includes almost all the serotypes pathogenic for humans. According to the current Salmonella nomenclature system, the full taxonomic designation S. enterica subspecies enterica serotype typhimurium can be shortened to Salmonella serotype typhimurium or simply S. typhimurium. Salmonellae are gram-negative, non-spore-forming, facultatively-anaerobic bacilli that measure 2–3 by 0.4–0.6 Â µm. The initial identification of salmonellae in the clinical microbiology laboratory was based on growth characteristics. Salmonellae produce acid on glucose fermentation, reduce nitrates, and do not produce cytochrome oxidase. In addition, all salmonellae except S. gallinarum-pullorum are motile by means of peritrichous flagella, and all but S. typhi produce gas (H2S) on sugar fermentation. Notably, only 1% of clinical isolates ferment lactose, and a high level of suspicion must be maintained to detect these rare clinical lactose-fermenters. 2. Incidence: Typhoid fever occurs worldwide, primarily in developing nations whose sanitary conditions are poor. Typhoid fever is endemic in Asia, Africa, Latin America, the Caribbean, and Oceania, but 80% of cases come from Bangladesh, China, India, Indonesia, Laos, Nepal, Pakistan, or Vietnam. Within those countries, typhoid fever is most common in underdeveloped areas. Typhoid fever infects roughly 21.6 million people (incidence of 3.6 per 1,000 population) and kills an estimated 200,000 people every year. In the United States and other developed nations, most cases of typhoid fever arise in international travelers. 3. Pathogenesis : All Salmonella infections begin with ingestion of organisms, most commonly in contaminated food or water. The infectious dose is 103–106 colony-forming units. Conditions that decrease either stomach acidity or intestinal integrity increase susceptibility to Salmonella infection. Once S. typhi and S. paratyphi reach the small intestine, they penetrate the mucus layer of the gut and traverse the intestinal layer through phagocytic microfold (M) cells that reside within Peyer patches. After crossing the epithelial layer of the small intestine, S. typhi and S. paratyphi, which cause enteric (typhoid) fever, are phagocytosed by macrophages. These salmonellae survive the antimicrobial environment of the macrophage by sensing environmental signals that trigger alterations in regulatory systems of the phagocytosed bacteria. In addition, salmonellae encode a second type III secretion system that directly delivers bacterial proteins across the phagosome membrane into the macrophage cytoplasm. This secretion system functions to remodel the Salmonella-containing vacuole, promoting bacterial survival and replication. Once phagocytosed, typhoidal salmonellae disseminate throughout the body in macrophages via the lymphatics, and colonize reticuloendothelial tissues (liver, spleen, lymph nodes, and bone marrow). Patients have relatively few or no signs and symptoms during this initial incubation stage. Signs and symptoms, including fever and abdominal pain, probably result from secretion of cytokines by macrophages and epithelial cells in response to bacterial products that are recognized by innate immune receptors when a critical number of organisms have replicated. Over time, the development of hepatosplenomegaly is likely to be related to the recruitment of mononuclear cells and the development of a specific acquired cell-mediated immune response to S. typhi colonization. The recruitment of additional mononuclear cells and lymphocytes to Peyer patches during the several weeks after initial colonization/infection can result in marked enlargement and necrosis of the Peyer patches, which may be medi ated by bacterial products that promote cell death as well as the inflammatory response. 4. Clinical features : Typhoid fever begins 7-14 days after ingestion ofS typhi.The fever pattern is stepwise, characterized by a rising temperature over the course of each day that drops by the subsequent morning. The peaks and troughs rise progressively over time. Over the course of the first week of illness, the gastrointestinal manifestations of the disease develop. These include diffuse abdominal pain and tenderness and, in some cases, fierce colicky right upper quadrant pain and also constipation. The individual then develops a dry cough, dull frontal headache, delirium, and an increasingly stuporous malaise. At approximately the end of the first week of illness, the fever plateaus at 39-40Â °C. The patient develops rose spots, which are salmon-colored, blanching, truncal, maculopapules usually 1-4 cm wide and fewer than 5 in number; these generally resolve within 2-5 days. During the second week of illness, the signs and symptoms listed above progress. The abdomen becomes distended, and soft splenomegaly is common. Relative bradycardia and dicrotic pulse (double beat, the second beat weaker than the first) may develop. In the third week, the still febrile individual grows more toxic and anorexic with significant weight loss. The conjunctivae are infected, and the patient is tachypneic with a thready pulse and crackles over the lung bases. Abdominal distension is severe. Some patients experience foul, green-yellow, liquid diarrhea (pea soup diarrhea). The individual may descend into the typhoid state, which is characterized by apathy, confusion, and even psychosis. Necrotic Peyer patches may cause bowel perforation and peritonitis. This complication is often unheralded and may be masked by corticosteroids. At this point, overwhelming toxemia,myocarditis[C1], or intestinal hemorrhage may cause death. If the individual survives to the fourth week, the fever, mental state, and abdominal distension slowly improve over a few days. Intestinal and neurologic complications may still occur in surviving untreated individuals. Weight loss and debilitating weakness last months. Some survivors become asymptomaticS typhicarriers and have the potential to transmit the bacteria indefinitely. However, there are some atypical presentations of classical typhoid fever and the clinical course of a given individual with typhoid fever may deviate from the above description of classic disease. The timing of the symptoms and host response may vary based on geographic region, race factors, and the infecting bacterial strain. The stepladder fever pattern that was once the hallmark of typhoid fever now occurs in as few as 12% of cases. In most contemporary presentations of typhoid fever, the fever has a steady insidious onset[C2]. Young children, individuals with AIDS, and one third of immunocompetent adults who develop typhoid fever develop diarrhea rather than constipation[C3]. In addition, in some localities, typhoid fever is generally more apt to cause diarrhea than constipation. Atypical manifestations of typhoid fever include isolated severe headaches that may mimic meningitis, acute lobar pneumonia, isolated arthralgias, urinary symptoms, severe jaundice, or fever alone. 5. Complications: These include the following: Gastrointestinal bleeding (10–20%of patients), intestinal perforation (1–3% of patients).Others are neurologic manifestations which occur in 2–40% of patients, including: meningitis, Guillain-Barre syndrome, neuritis, and neuropsychiatric symptoms usually described as muttering delirium or coma vigil, with picking at bedclothes or imaginary objects. Rare complications include: Disseminated intravascular coagulation, haematophagocytic syndrome, pancreatitis, hepatic and splenic abscesses and granulomas, endocarditis, pericarditis, myocarditis, orchitis, hepatitis, glomerulonephritis, pyelonephritis and hemolytic-uremic syndrome, severe pneumonia, arthritis, osteomyelitis, and parotitis. Fewer than 10% of patients develop mild relapse, usually within 2–3 weeks of fever resolution and in association with the same strain type and susceptibility profile.About 10% of untreated patients with typhoid fever excrete S. typhi in their feces for up to 3 months, and 1–4% develop chronic asymptomatic carriage, shedding S. typhi in either urine or stool for greater than one year. Chronic carriage is more common among women, infants, and persons who have biliary abnormalities or concurrent bladder infection with Schistosoma haematobium. 6. Examination and tests: The diagnosis of typhoid fever (enteric fever) is primarily clinical. However there are series of tests which could confirm the diagnosis . These tests are : Cultures: Blood, bone marrow, stool and urine specimens. Blood Cultures are widely considered 100% specific while culture of bone marrow aspirate is 90% sensitive until at least 5 days after commencement of antibiotics. The technique is extremely painful, which may outweigh its benefit. Blood, intestinal secretions (vomitus or duodenal aspirate), and stool culture results are positive for S typhi in approximately 85%-90% of patients with typhoid fever who present within the first week of onset. They decline to 20%-30% later in the disease course. In particular, stool culture may be positive for S typhi several days after ingestion of the bacteria secondary to inflammation of the intraluminal dendritic cells. Bone marrow aspiration and blood are cultured in a selective medium (eg, 10% aqueous oxgall) or a nutritious medium (eg, tryptic soy broth) and are incubated at 37Â °C for at least 7 days. Subcultures are made daily to one selective medium (eg, MacConkey agar) and one inhibitory medium (eg, Salmonella-Shigella agar). Identification of the organism with these conventional culture techniques usually takes 48-72 hours from acquisition. Molecular Method: Polymerase chain reaction (PCR) has been used for the diagnosis of typhoid fever with varying success. Nested PCR, which involves two rounds of PCR using two primers with different sequences within the H1-d flagellin gene of S typhi, offers the best sensitivity and specificity. Combining assays of blood and urine, this technique has achieved a sensitivity of 82.7% and reported specificity of 100%. Serologic tests : These are assays that identify Salmonella antibodies or antigens, supporting the diagnosis of typhoid fever, but these results should be confirmed with cultures or DNA evidence. The Widal test was the mainstay of typhoid fever diagnosis for decades. It is used to measure agglutinating antibodies against H and O antigens of S typhi. Neither sensitive nor specific, the Widal test is no longer an acceptable clinical method. Indirect hemagglutination, indirect fluorescent Vi antibody, and indirect enzyme-linked immunosorbent assay (ELISA) for immunoglobulin M (IgM) and IgG antibodies to S typhi polysaccharide, as well as monoclonal antibodies against S typhi flagellin are promising, but the success rates of these assays vary greatly in the literature. Other non-specific laboratory studies Most patients with typhoid fever are moderately anemic, have an elevated erythrocyte sedimentation rate (ESR), thrombocytopenia, and relative lymphopenia. Most also have a slightly elevated prothrombin time (PT) and activated partial thromboplastin time (aPTT), and decreased fibrinogen levels. Circulating fibrin degradation products commonly rise to levels seen in subclinical disseminated intravascular coagulation (DIC). Liver transaminase and serum bilirubin values usually rise to twice the reference range. Mild hyponatremia and hypokalemia are common. A serum alanine amino transferase (ALT)–to–lactate dehydrogenase (LDH) ratio of more than 9:1 appears to be helpful in distinguishing typhoid from viral hepatitis. A ratio of greater than 9:1 supports a diagnosis of acute viral hepatitis, while ratio of less than 9:1 supports typhoid hepatitis Differential diagnosis: This includes include Malaria, Hepatitis, Bacterial enteritis, dengue fever, rickettsial infections, leptospirosis, amebic liver abscesses, and acute HIV infection. 7. Risk factors: a Gastric Factors : Antacids, histamine-2 receptor antagonists (H2 blockers), proton pump inhibitors, gastrostomy, and achlorhydria decrease stomach acidity and facilitate S typhi infection. b. Genetic and host factors: Genetic polymorphisms. c. Environmental and behavioural risk factors that are independently associated with typhoid fever include: 1. Eating food from street vendors, Living in the same household with someone who has new case of typhoid fever, Washing the hands inadequately, Sharing food from the same plate, Drinking unpurified water, and Living in a household that does not have a toilet 8. Treatment: The proper treatment approach to typhoid fever depends on whether the illness is complicated or uncomplicated. Complicated typhoid fever is characterized by melena (3% of all hospitalized patients with typhoid fever), serious abdominal discomfort, intestinal perforation, marked neuropsychiatric symptoms, or other severe manifestations. Depending on the adequacy of diagnosis and treatment, complicated disease may develop in up to 10% of treated patients. Medical Care: If a patient presents with unexplained symptoms suggestive of typhoid fever (enteric fever), broad-spectrum empiric antibiotics should be started immediately. Treatment should not be delayed for confirmatory tests since prompt treatment drastically reduces the risk of complications and fatalities. Antibiotic therapy should be narrowed once more information concerning the definitive diagnosis is available. Recommended antibiotic therapies are Cefixime, Azithromycin and Ciprofloxacin per oral for uncomplicated cases, while Ceftriazone, Azstereonam, Cefotaxime and Imipenem could be administered intravenously for complicated cases . Patients with uncomplicated disease may be treated on an outpatient basis. They must be advised to use strict hand washing techniques and to avoid preparing food for others during the illness course. Hospitalized patients should be placed in contact isolation during the acute phase of the infection. Feces and urine must be disposed of safely. Surgical care: Surgery is usually indicated in cases of intestinal perforation. Most surgeons prefer simple closure of the perforation with drainage of the peritoneum. Small-bowel resection is indicated for patients with multiple perforations. If antibiotic treatment fails to eradicate the hepatobiliary carriage, the gallbladder should be resected. Cholecystectomy is not always successful in eradicating the carrier state because of persisting hepatic infection. 9. Home treatment of First Aid (where applicable): No home treatment for typhoid fever. 10. Prevention. This involves the following measures: Protect and chlorinatepublic water supplies. Provide safe water supplies and avoid possible back flow connections between sewers and water supplies. Dispose of human faecesin a sanitary manner and maintain fly-proof latrines. Use scrupulouscleanliness in food preparationand handling. Educate the public regarding theimportance of handwashing: this is important for food handlers and attendants involved in the care of patients and/or children. Immunization for typhoid fever is recommended for international travellers to endemic areas, especially if travel will involve exposure to unsafe food and water or close contact in rural areas and with indigenous populations 11. Local names in Nigeria: Akom in Igbo,; Zazabi chiwo nkpanyo in Hausa and iba jeefun jeefun in Yoruba.. 12. Endemic areas Typhoid fever usually occurs in developing nations whose sanitary conditions are poor. Typhoid fever is endemic in Asia, Africa, Latin America, the Caribbean, and Oceania, but 80% of cases come from Bangladesh, China, India, Indonesia, Laos, Nepal, Pakistan, or Vietnam. Within those countries, typhoid fever is most common in underdeveloped areas. 13. Disease images Rose spots on the chest of a patient with typhoid fever due to the bacteriumSalmonella Lizzie van Zylwas a child inmate in a British-run concentration camp in South Africa who died from typhoid fever during theBoer War(1899–1902) References http://emedicine.medscape.com/article/231135-overview#3 http://www.who.int/topics/typhoid_fever/en/ http://www.nlm.nih.gov/medlineplus/ency/article/001332.htm http://www.infectionlandscapes.org/2011/11/typhoid-fever.html http://www.cdc.gov/nczved/divisions/dfbmd/diseases/typhoid_fever/ http://textbookofbacteriology.net/salmonella.htm Anthony S. Fauci et al, Harrisons’s Principles of Internal Medicine 17th edition 2008. Gerald L. Mandell et al, Mandell, Douglas and Bennett’s Principles and Practice of Infectious Disease 7th edition,2010. [C1]Shows link from Medscape. Article shows several similarities to Medscape article. [C2]Highlight [C3]Highlight

Carbon Mesoporous Material Hybrid Catalyst

Carbon Mesoporous Material Hybrid Catalyst Facile and clean transformation for synthesizing secondary arylamines through one-pot reductive amination of aniline, using aldehyde catalyzed by the supported nickel and poly(vinyl sulfonic acid) on mesoporous carbon CMK-3 (Ni/PVSA/CMK-3) as a novel acid-metal bi-functional heterogeneous catalyst. Sodium borohydride was used as the source of hydrogen for the reduction of imine. The reaction was performed at room temperature, in a short reaction time, without any by-products. Various characterization techniques including FT-IR, XRD, TG, BET, SEM, TEM, DRS-UV and AAS were employed to reveal the relationship between catalyst nature and catalytic performance. Reaction results demonstrate that the optimized Ni/PVSA/CMK-3 catalyst shows comparable catalytic performance thanks to the nickel metals and the acidic nature of polymer in mesopore channels of CMK-3. This method has several advantages such as, eco-friendly (used water as solvent), moderate to high yields, simple work-up procedure and catalyst filtered easily and reused without obvious loss of activity. 1. Introduction Nowadays, amines are privileged in industry that have found prevalent applications as intermediates for pharmaceuticals, biologically active compounds, rubber, solvents, fine chemicals, dyes, herbicides, and in the manufacture of detergents and plastics. Reductive amination demonstrate one of the most versatile and convenient methods of amine synthesis. This reaction has two steps including formation of an imine during reaction between primary amine and a carbonyl substrate, and reduction of the imine with adequate hydride source. There are two detached approaches for the reductive amination: the direct approach, which uses the in situ-generated imine, and the indirect approach, which uses the prior isolated imine. The former approach has several advantages such as one-pot procedure, increasing yields, having simple setup, easily separated from the product, being stable and compatible reagents, and the mild reaction conditions. To this end, over the past decades, researchers have been reported several studies on reductive amination reaction with several different catalysts, which among them, heterogeneous catalysis are prominent than homogenous catalysis owing to separate and recover capabilities. Moreover, it has been proven that accomplish this reaction needs two character including metallic and acidic; consequently, bi-functional heterogeneous catalysts are useful in this reaction. Recently, several metal nanoparticles acted as a hydride transfer such as Pt, Ni, Cu, and Pd. Despite of the fact that an effective control of particle size and a uniform distribution of nanoparticles in catalytic applications are generally predicted, nanoparticles typically accumulate together in bulk-like materials that hardly reduce selectivity and the activity of catalysts. To overcome with this problem, mesoporous silica, zeolites, polymers or macromolecular organic ligands have been used in order to immobilize metal nanoparticles in their pores. Mesoporous silica materials and zeolites have excellent order and surface area than other materials like polymer and etc.; subsequently, they are sufficient for catalysis approaches. Lately, mesoporous silica used for producing mesoporous carbon (CMK-n) as hard template. These materials contain several benefits compared to mesoporous silica and zeolites for instance, high mechanical stability, high thermal stability in nitrogen atmosphere, superb stability in strong acids and bases, and other engrossing properties such as narrow pore size distributions, high surface areas, and ordered frameworks. In addition, mesoporous carbon materials have hydrophobic nature on their surfaces and it helps to embed nanopolymers in their pores. In our previous studies, it asserts that when polymer embedded into mesoporous materials, they have perfect function. Owing to the fact that they have small particles and subsequently having high surface areas. Moreover, polymer nanoparticles fix in porous and they could not leach from their supporters. Accordingly, in this work, we will introduce a novel heterogeneous organic hybrid catalyst based on a carbon mesoporous material. In this circumstance, mesoporous carbon CMK-3 replicating from mesoporous silica SBA-15 was prepared and used as suitable support for Nickel nanoparticle/poly vinyl sulfonic acid/CMK-3 (Ni/PVSA/CMK-3). Furthermore, the catalyst was used effectively for the one-pot reductive amination of amine compounds using aldehyde in the presence of a small amount of NaBH4 as a mild reducing agent and two sort of solvent containing water and acetonitrile at room temperature without any by-products. 2. Experimental method 2.1. Catalyst characterization The samples have been analyzed by FT-IR spectroscopy (using a PerkinElmer 65 in KBr matrix in the range of 4000-400 cm-1). The thermal gravimetric analysis (TGA) data were obtained by a Setaram Labsys TG (STA) in a temperature range of 30-650 -C and heating rate 10 -C min-1 in nitrogen atmosphere. The X-ray powder diffraction (XRD) of the catalyst was carried out on a Bruker D8Advance X-ray diffractometer using nickel filtered Cu KÃŽ ± radiation at 40 kV and 20 mA. The BET specific surface areas and BJH pore size distribution of the samples were determined by adsorption-desorption of nitrogen at liquid nitrogen temperature, using a Series BEL SORP 18. For the measurement of nickel, a Perkin Elmer AAnalyst 300 atomic absorption spectrophotometer was used. The slit width, linear range and wave length for Ni were 0.2 nm, 2 and ppm232 nm, respectively. Scanning electron microscope (SEM) studies were performed on Philips, XL30, SE detector. Transmission electron microscope (TEM) observati ons were performed on a JEOL JEM.2011 electron microscope at an accelerating voltage of 200.00 kV using EX24093JGT detector in order to obtain information on the size of nickel nanoparticles and the DRS UV-vis spectra were recorded with JASCO spectrometer, V-670 from 190 to 2700 nm. Moreover, X-ray photoelectron spectra (XPS) was recorded on ESCA SSX-100 (Shimadzu) using a non-monochromatized Mg KÃŽ ± X-ray as the excitation source. The products were characterized by 1H NMR and 13C NMR spectra (Bruker DRX-500 Avance spectrometer at 500.13 and 125.47 MHz, respectively). Melting points were measured on an Electrothermal 9100 apparatus and they were uncorrected. All the products were known compounds and they were characterized by FT-IR, 1H NMR and 13C NMR. All melting points are compared satisfactorily with those reported in the literature. 2.2. Catalyst preparation The employed mesoporous carbon (CMK-3) was synthesized following the method reported by Ryoo using SBA-15 as template. 2.2.1. Preparation of SBA-15 Mesoporous silica SBA-15 was prepared using block copolymer Pluronic P123 (EO20PO70EO20) template as a structure directing agent and tetraethylorthosilicate (TEOS) as the silica precursor through the addition of H3PO4 by novel method as described in the literature. In a general synthesis, Pluronic P123 (2 g) was dissolved at room temperature in deionized water (75.4 mL) and H3PO4 (4.2 mL, 85%), after that TEOS (4.6 mL) was added to the solution and synthesis was fulfilled by stirring at 35 -C for 24 h in sealed Teflon breakers, and it was consequently placed at 100 -C for 24 h. Afterwards, the solution was filtered, washed with deionized water, and lastly dried at 95 -C for 12 h in air. Template removal was accomplished by calcination in air using two successive steps; first heating at 250 -C for 3 h and then at 550 -C for 4 h. 2.2.2. Preparation of CMK-3 Mesoporous carbon CMK-3 was prepared using mesoporous silica SBA-15 as template and sucrose as the carbon precursor. 1.0 g SBA-15 was added to 5 mL aqueous solution containing 1.25 g (3.65 mmol) sucrose and 0.14 g (1.42 mmol) of H2SO4 (98%). The resulting mixture was heated in an oven at 100 -C for 6 h and next 160 -C for another 6 h. In order to obtain entirely polymerized sucrose inside the pores of the SBA-15 template, 5 mL aqueous solution containing 0.8 g (2.33 mmol) sucrose and 0.09 g (0.917 mmol) of H2SO4 were added again, and the mixture was subjected to the thermal treatment described above one more time. Then, it was carbonized under nitrogen gas flow at 900 -C for 6 h with a heating rate of 5 -C min-1. Finally, the resulting solid was washed with 1 M NaOH solution (50 vol. % ethanol-50 vol. % H2O) twice to remove the silica template, filtered, washed with ethanol until pH = 7, and dried at 100 -C for 4 h. 2.2.3. Preparation of Poly(vinyl sulfonic acid)/CMK-3 2.2.4. Preparation of Ni nanoparticle-poly(vinyl sulfonic acid)/CMK-3 At first, Vinylsulfonic acid sodium was converted into its acidic form using the ion exchange resin (Amberjet 1200 H, 2 equiv. L-1, Aldrich). Ni/PVSA/CMK-3 was synthesized as follows: in the first place, 1 mL aqueous solution of NiCl2.6H2O (0.5 M) was added to the obtained PVSA/CMK-3 (0.1 g) together with 3 mL of H2O. The mixture was heated for 5 h at 353 K. Next, the solution of NaBH4 [0.057 g (1.5 mmol)] dissolved in 5 mL methanol was added to the mixture drop by drop in 20-30 min. Then, the solution was stirred for 3 h. After that, adding the same amount of NaBH4 was repeated and again the mixture was stirred for 3 h. Consequently, the solution was filtered and washed sequentially with deionized water and methanol to remove excess NaBH4 and NiCl2, and was dried in room temperature to yield Ni/PVSA/CMK-3. The Ni content of the catalyst was estimated by decomposing. Known amount of the catalyst by perchloric acid, nitric acid, fluoric acid, hydrochloric acid, and the Ni content was estimated by atomic absorption spectrometer. The Ni content of Ni/PVSA/CMK-3 estimated by atomic absorption spectrometer was 2.1 mmol g−1. 2.3. General procedure for one-pot reductive amination of aldehydes. A mixture of Aniline (2 mmol) and benzaldehyde (2 mmol) in water or acetonitrile (3 mL) was placed in a round bottom flask and stirred for 1 min at room temperature. Afterward, to the resulting mixture, Ni/PVSA/CMK-3 (0.04 g) and NaBH4 (6 mmol) were added and the mixture was stirred at room temperature until TLC showed the complete disappearance of the benzaldehyde. Then, the reaction mixture was quenched with water (10 mL) and the product was extracted with diethylether (2 10 mL). After they finished, the organic phase was dried over anhydrous Na2SO4, filtered and concentrated. In the end, the products were obtained very pure just by extract with diethylether in the majority of the reactions. The product was identified with a melting point, FT-IR spectroscopy techniques, 1HNMR and 13CNMR. 3. Results and discussion 3.1. Catalyst characterization Figure 1 shows the FTIR spectra of CMK-3 (a), PVSA/CMK-3 (b) and Ni/PVSA/CMK-3 (c). A broad band at around 3380-3470 cm−1 was observed in all samples. The O-H stretching vibration of the adsorbed water molecules mainly caused it. Moreover, in the CMK-3 spectrum, there are not any signals belong to organic bonds, resulting from the complete carbonization of sucrose (Fig. 1a). The presence of a new absorption bands at 1041 and 1186 cm-1 attributed to the S=O group of PVS, affirming the existence of the grafted PVSA chains on the CMk-3. In addition, the band at about 1650 cm-1 is attributed to adsorbed water, which is similar to related reports[]. The presence of peaks at around 2940 cm−1 and 1450 cm−1 correspond to the aliphatic C-H stretching and bending in PVSA/CMK-3, respectively (Fig. 2b). The appearance of the above bands shows that PVSA has been attached into mesoporous of CMK-3 and the synthesis of PVSA/CMK-3 has been successful. The profiles of thermogravimetric analysis of PVSA/CMK-3 and Ni/PVSA/CMK-3 under nitrogen atmosphere are shown in Fig. 2. The degradation of Poly(vinyl-sulfonic acid) commences at 150C and this stage continues to a little less than 300C. The next stage involves only a little degradation and occurs over the temperature range of 300 to 500C. These evidence are shown Poly(vinyl-sulfonic acid) cannot tolerant the temperature due to polymers are not protect by any supporter. The TGA curves of PVSA/CMK-3 shows a small mass loss (around 5%, w/w) in the temperature range of 100-330 -C, which is apparently associated with degradation of SO2 and ethylene from PVSA (Fig. 2). At temperatures above 330 -C, PVSA shows one main stage of degradation. The mass loss for PVSA in the second step is equal to 11.5% (w/w) which correspond to the degradation of the methane. In light of the difference between the PVSA and PVSA/CMK-3 curves, it is clear that PVSA/CMK-3 has higher thermal stability and slower degradation rate than PVSAP. Hence, after hybridization, the thermal stability is enhanced significantly that is beneficial for the catalyst application. In addition, Ni/PVSA/CMK-3 shows two separate weight loss steps that are almost similar to the PVSA/CMK-3. The only difference is temperature between 330 and 445 C, which Ni/PVSA/CMK-3 shows slower degradation rate than PVSA/CMK-3 in these range. It asserts that the hybrid Ni/PVSA/CMK-3 had higher thermal stability than PVSA/CMK-3. It may be related to the presence of Nickel nanoparticles in the composite structure. Consequently, it is proper thermal stability is boosted after hybridization because of intense the catalyst application. Figure 1 shows the powder XRD patterns of SBA-15, CMK-3, PVSA/CMK-3 and Ni/PVSA/CMK-3. The low angle diffraction pattern of SBA-15 shows three reflections at 2à Ã‚ ´ values from 0.5 to 2 ° including one strong peak at (100) and two weak peaks at (110) and (200), which corresponds to the well-known ordered arrangement of SBA-15 in the space group p6mm of 2-D hexagonal symmetry. The silica SBA-15 used as template to synthesis CMK-3. As can be seen, the XRD pattern of CMK-3 show three diffraction peaks at 2à Ã‚ ´ = 1.04 °, 1.79 ° and 2.05 ° (Fig. 3b). It could be marked to (100), (110) and (200) diffractions of the 2D hexagonal space group p6mm, which is compatible with previous articles. After polymerization by poly (vinyl sulfonic acid), the X-ray diffraction of PVSA/CMK-3 shows the same pattern with CMK-3. This evidence indicates that the structure of the CMK-3 was retained after the polymerization (Fig. 3c). Albeit, the intensity of the characteristic reflection peaks of the PVSA/CMK-3 is found to be diminished (Fig. 1b). Composite contains less CMK-3 due to the dilution of the carbon material by PVSA; subsequently, this dilution can be responsible for a decrease in the peak intensity. By the way, the XRD patterns of CMK-3 and PVSA/CMK-3 are almost similar to SBA-15, which it shows CMK-3 is a accurate replica of the mesoporous silica SBA-15 and the polymerization process does not damage the structure of CMK-3. After immobilize nickel in the PVSA/CMK-3, Ni peak cannot be seen in XRD since the homogeneity of Ni particles in the Ni/PVSA/CMK-3, and it lonely shows an amorphous pattern at 2ÃŽ ¸ values of about 44ËÅ ¡ (Fig. 3, inside). In order to demonstrate the e xistence of Ni nanoparticles in the Ni/PVSA/CMK-3 catalyst was exposed to temperature (400ËÅ ¡C). Meanwhile, amorphous Ni changed to crystalline and appear a peak with low intensity at 2ÃŽ ¸ = 44.29ËÅ ¡, which can be attributed to the small size of nickel nanoparticles and the plane (111) of fcc nickel. Eventually, after immobilize the nickel nanoparticles on composite, structure has not changed and it is represented a successful synthesis of the catalyst. The specific surface area, pore volume and the pore size of the CMK-3, PVSA/CMK-3 and Ni/PVSA/CMK-3 samples are summarized in Table 1. All samples exhibit a type IV adsorption isotherm with an H1 hysteresis loop by capillary condensation at relative pressure around 0.3-0.7 (Fig. 4). It is clear in table 1 that the PVSA/CMK-3 and Ni/PVSA/CMK-3 exhibits a smaller specific surface area, and pore volume in comparison to those of pure CMK-3. Thanks to the successful incorporation of the poly(vinyl sulfonic acid) into the mesoporous carbon. As can be seen, pore diameter increases in the PVSA/CMK-3 and Ni/PVSA/CMK-3 in comparison to CMK-3. This evidence shows the incorporation and growth of hyperbranched polymers and consequently produces the pressure (physical pressure on the wall of the channels) inside the CMK-3 mesoporous. By adding Ni nanoparticles into the PVSA/CMK-3, the specific surface area and pore volume decrease, asserting that nickel nanoparticles are located inside the pores o f the CMK-3. In spite of the fact that there are significant decreases in the pore volume and surface area, the pores of Ni/PVSA/CMK-3 were not blocked by deposition of the hyperbranched homopolymer and nickel nanoparticles. Moreover, the BJH pore size distribution curves of the PVSA/CMK-3 and Ni/PVSA/CMK-3 are exhibited a narrow pore size distribution (Fig. 5). It clarifies that the homopolymer and nickel nanoparticles are satisfactory distributed on the channels of the Ni/PVSA/CMK-3. This result is agreement with TEM analysis and shows the effective role of the hyperbranched polymer to entrap and uniformly disperse nickel nanoparticles. , , Fig. 6 gave the scanning electron microscopy (SEM) photographs of CMK-3 and PVSA/CMK-3 and Ni/PVSA/CMK-3. All the SEM images are shown rod-like morphology, which is attributed to carbon mesoporous. Although, virtually no significant differences observe in surface morphology between CMK-3 and PVSA/CMK-3, it is obvious that after hybridization the surface of CMK-3 is become coarser; indicating the most of polymerization of PVSA occurred in the pores of CMK-3, which was also supported by the decrease in surface area and pore volume as shown in Table 1. In addition, by immobilizing Ni nanoparticles, several spherical beads are seen on the mesoporous carbon. However, most of them are incorporated inside the carbon mesoporous structure, which is not observable in the SEM images. It is necessary to mention that after loading nickel nanoparticles on the surface of CMK-3, the structure of the mesoporous carbon is remained. Moreover, XRD analysis and TEM images confirmed this claim. The PVSA/CMK-3 and Ni/PVSA/CMK-3 were inspected by means of TEM micrographs technique (Fig. 7). The ordered hexagonal p6mm mesostructure of PVSA/CMK-3 and Ni/PVSA/CMK- 3 can be seen, indicating after polymerization and incorporation of PVSA and Ni nanoparticles, the ordered structure of mesoporous carbon is retained. Additionally, the places with darker contrast could be assigned to the presence of Pd particles with different distribution (Fig. 7c-d). As can be seen, the small dark spots could be ascribed to nickel nanoparticles with ∠¼X nm average diameter, presumably located into the mesoporous channels. On the other hand, larger dark spots are shown in fig. 7 c-d, which are corresponded to Ni nanoparticles agglomerate on the external surface with average diameter of ∠¼5-10 nm. Fig. 8 shows the DRS-UV of PVSA/CMK-3 and Ni/PVSA/CMK-3. previous reports were proven that DRS-UV of the cationic nickel have only d-d transitions peaks including 3T1g(P)↠3A2g (F) (368 nm) and 3T1g (F)↠3A2g (F) (576 nm), which these two peak do not show in Ni/PVSA/CMK-3. Moreover, the DRS-UV of Ni/PVSA/CMK-3 shows feature bands around 205 nm and 330 nm, which are attributed to the presence of Ni nanoparticles in these samples. By comparing these data, it can be found that cationic nickels are converted to the nickel nanoparticles by reduction of NaBH4. 3.2. Catalytic activity Synthesized nanocomposite was characterized by different methods in the former section. This section is introduced the application of this bi-functional catalyst to the reductive amination reaction. During two decade, enormous investigation devoted to develop environmental friendly synthesis. Since, using water as a reaction medium in transition metal-catalyzed processes is one of the most essential goal of sustainable chemistry. Water is nontoxic solvent, readily available, an inexpensive, nontoxic solvent and non-inflammable. It provides privilege over organic solvents from an environmental and an economic aspect. Accordingly, the effect of several parameters on the one-pot tandem reductive amination of aldehydes with aniline over Ni/PVSA/CMK-3 as acid-metal bifunctional catalyst was perused in water at room temperature and the outcome are as follows: At the first monitoring of experiments, diverse amounts of NiCl2.6H2O were tested to identify the effect of nickel nanoparticles concentration on the reductive amination reaction. Hence, the amount of NiCl2.6H2O to prepare Ni/PVSA/CMK-3 was changed from 1 mmol/g to 15 mmol/g and then measured by the Atomic Absorption spectroscopy technique (AAS) which are shown in Table 2. It is clear that the activity of catalytic steadily improved by increasing NiCl2.6H2O form 1 mmol/g to 5 mmol/g. According to the catalytic reaction mechanism, nickel nanoparticle mediated electron transfer from BH4- ion to the imine intermediates (Scheme 1). Subsequently, the amounts of H- sites on the catalyst surface are grown by increasing nickel nanoparticles. Thus, larger amount of hydrides can be transferred to the imine groups through the catalyst. On the other hand, by further increasing the amount of NiCl2.6H2O (more than 5 mmol/g), the catalytic activity was diminished, which can be attributed to after a certain amount of nickel chloride increases, a larger amount of nanoparticles is loaded on the surface of the CMK-3 that may have caused the mesopore channels to narrow. In Fact, the nanoparticle size will increase by increasing the amount of NiCl2.6H2O. Therefore, in some places, the pore size will narrow and it is able to lessen the rate of reactants diffusion into the porous. In one word, lower performance of the catalyst produced with higher NiCl2.6H2O concentration will be anticipated. Despite of this fact, it does not mean the pores are throughout clogged. According to these results, the catalyst provided by 5 mmol/g NiCl2.6H2O presented the best catalytic activity. To identify the effect of NaBH4 amount (as a hydride donor) on the reductive amination the reaction was carried out using various amounts of NaBH4 in the presence of Ni/PVSA/CMK-3 as catalyst. As shown in Table 3, the yield was increased by increasing the amount of NaBH4 (until 6 mmol). The excess values did not have any effect on the reaction. Therefore, 6 mmol NaBH4 was the best value to perform reductive amination reaction. The influence of the solvent on catalytic activity was investigated in the reductive amination reaction using Ni-PVSA/CMK-3 catalyst and NaBH4 as hydride donor, at room temperature. The results are gathered in Table 4. Four vital factor acts to fulfil reductive amination reaction including dielectric constant, dipole moment, solubility in NaBH4, hydrophobic effect, protic and aprotic solvent effect. The results revealed that the reaction time in ethanol solvent is slow due to NaBH4 hardly solving in ethanol and the reaction rate is tardy. In addition, the reaction rate in water solvent is slow because although dielectric constant and solubility of water in NaBH4 is high, carbon mesoporous CMK-3 have hydrophobic nature. It causes substances and catalyst cannot have perfect interaction together. The hydrophobic nature of acetonitrile and oxolane are higher than other solvent that presented above; thus, these two solvent have more similarity to hydrophobic nature of CMK-3. Moreover, dipole moment of acetonitrile is higher than other solvent. Thanks to this feature, the reaction rate increase. Whereas the methanol solvent has mediate circumstance of dielectric constant, solubility in NaBH4, and hydrophobic effect aspect, the reaction time diminish. It is noteworthy to mention that the combination of all these factors together cause this process. Regarding these situation, water and acetonitrile were finally selected as the solvent for the reaction because of their environmental friendly and highly efficient, respectively; and all other optimization and reaction separately accomplished by these two solvent. The effect of the amount of catalyst was defined for reductive amination reaction (Table 5). Due to the fact, the catalyst synthesized is worthy, it is decided that the amount of catalyst optimize by decreasing down to the 0.04 g, nevertheless the reaction time were increased. However, reducing the amount of catalysts until 0.02 g was not sufficient. Since, the quantity of 0.04 g for both solvent was found to be the best weight of catalyst. The reusability of the catalyst was studied by using Ni/PVSA/CMK-3 in water and acetonitrile solvent (Chart 1). After each cycle, the catalyst was filtered off, washed with water (10 mL) and ethanol (3 mL 5 mL). After that, catalyst dried at 60 ËÅ ¡C and reused in the reductive amination reaction with a fresh reaction substances. It might be noted that after each run, a slight amount of the catalysts were lost in the filtration process. Herein, to overcome this problem, after each experiment the amount of remaining catalyst was specified and the molar ratio of the reactants was adjusted according to the remaining amount of the catalyst. The catalyst was reused up to 5 times. The catalyst that react in acetonitrile solvent have serious loss activity. In further investigation, it recognized that the catalyst used in acetonitrile solvent was somewhat destroyed. It can be attributed to the interaction between acetonitrile as a solvent and PVSA/CMK-3 composite. In other cases, not o nly the reusability of the catalyst that performed in water was adequate, but also the catalyst exhibit high stability in this status. This result obtained by SEM and XRD characterization, which can be seen in Figure 9 and 10. As shown in SEM images of reused catalyst in water as reaction solvent is well retained, which is very essential for the catalyst applications. Similarly, the XRD pattern shows a diffraction peak at low angle (1.04 °). It display that the catalyst structure remain. Because of this fact that the reusability in the heterogeneous catalysts is fundamental, water in reductive amination reaction chosen as a compatible solvent. The catalytic activity of the Ni/PVSA/CMK-3 in the reductive amination was compared with CMK-3, PVSA/CMK-3, and without a catalyst. The results are available in Table 6. The consequences affirm the significance role of the acid-metal heterogeneous catalyst in sort of reaction. As shown, the reaction dose not fulfil up to 5% without catalyst. There is the important issue that NaBH4 function as a mild hydride donor agent, which is incapable reagent for reducing imine groups solely. In a similar manner, this result obtained by using CMK-3 due to the fact that mesoporous carbon CMK-3 does not have any active sites to carry out the reaction. By using the PVSA/CMK-3, with improve acidic feature of the mesoporous carbon the carbonyl group activated and thus the yield moderately increased to 40% and 35% in acetonitrile and water solvent, respectively. In addition, using Ni/PVSA/CMK-3, the reaction efficiency was increased to 97% in 35 and 63 min in acetonitrile and water solvent, respectivel y; Because of the role of nickel nanoparticles as species to transfer hydride ions from NaBH4 to imine groups. The interesting point in catalyst investigation is heterogeneous nature. In this regard, the catalyst was separated from the reaction mixture at approximately 50% conversion of the starting substances by filtration and then centrifugation. The reaction progress in the filtrate circumstance was monitored (data not shown). No further reductive amination reaction occurred even at addition times, representing that the nature of reaction process is heterogeneous and there is not any progress for the reaction in homogeneous phase.

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Custom Papers English Foreign History Miscellaneous Movies Music Novels People Politics Religion Science Sports Technology Information Questions? Search results for 'mark and twain' -------------------------------------------------------------------------------- Match: AllAnyBoolean Format: LongShort Sort by: ScoreTimeTitleReverse ScoreReverse TimeReverse Title Refine search: -------------------------------------------------------------------------------- Documents 1 - 10 of 527 matches. -------------------------------------------------------------------------------- Can't find it with this search, try this one! Mark Twain's Life in His Writings In Mark Twain's two major works, The Adventures of Tom Sawyer, and it's sequel The Adventures of Huckleberry Finn, he develops and displays his humoristic abilities by concealing within them deeper meanings, ultimately producing a satire of the region in which he lived. Examined within this paper are ... Mark Twain Mark Twain "Man is made of dirt †¦ Man is a museum of diseases, a home of impurities, who begins as dirt and departs as stench."(1) -Mark Twain When Most people think of Mark Twain, they think of the Mississippi, or gold mining, or such things. But few people have come to realize the free ... Mark Twain Racisim Part 2: Was Mark Twain a Racist? For over thirty years critics of Mark Twain have called attention to the racial epithets in Huckleberry Finn as an example of the inherent racism of the author. African Americans in particular have objected to the book and in many school districts (most recently in Dallas ... How Mark Twain lived his life as an author during the late 1800's Question: How Mark Twain lived his life as an author during the late 1800's? Title: Mark Twain's biograph. I. Introduction A. Background 1. Childhood 2. Education 3 Professional life B. Problems: 1. Jobs 2. Literary works 3. Financial conditions II. Body A. Life style B. Family life C.General information ... Mark Twain Censorship The Adventures of Huckleberry Finn is a book written by Mark Twain. This book has been scrutinized, censored, and argued over since it’s publication. There are many ways to look at Huckleberry Finn. One can look at it as a derogatory book, focusing on the stereotyping of Negroes and the excessive use ... Mark Twain, Samuel Clemens, or None of the Above Mark Twain was one of the most popular and well-known authors of the 1800’s. He is recognized for being a humorist. He used humor or social satire in his best works. His writing is known for â€Å"realism of place and language, memorable characters, and hatred of hypocrisy and oppression† (Mark Twain 1 ... mark twain Mark Twain, a Racist?Mark Twain was a man that was way ahead of his time. In a time when people were judged on color,Mark Twain grew up in Florida, Missouri (Mandelbrot, Twain).