B Cells

B Cells B cells are white blood cells that protect the body against pathogens such as bacteria and viruses. Pathogens and foreign matter have associated  molecular signals that identify them as antigens. B cells recognize these  molecular signals and produce antibodies that are specific to the specific antigen. There are billions of B cells in the body. Unactivated B cells circulate in the blood until they come in contact with an antigen and become activated. Once activated, B cells produce the antibodies needed to fight against infection. B cells are necessary for adaptive or specific immunity, which focuses on the destruction of foreign invaders that have gotten past the bodies initial defenses. Adaptive immune responses are highly specific and provide long-lasting protection against the pathogens that elicit the response. B Cells and Antibodies B cells are a specific type of white blood cell called a lymphocyte. Other types of lymphocytes include T cells and natural killer cells. B cells develop from stem cells in bone marrow. They remain in the bone marrow until they become mature. Once they are fully developed, B cells are released into the blood where they travel to lymphatic organs. Mature B cells are capable of becoming activated and producing antibodies. Antibodies are specialized proteins  that travel through the bloodstream and are found in bodily fluids. Antibodies recognize specific antigens by identifying certain areas on the surface of the antigen known as antigenic determinants. Once the specific antigenic determinant is recognized, the antibody will bind to the determinant. This binding of the antibody to the antigen identifies the antigen as a target to be destroyed by other immune cells, such as cytotoxic T cells. B Cell Activation On the surface of a B cell is a B cell receptor (BCR) protein. The BCR enables B cells to capture and bind to an antigen. Once bound, the antigen is internalized and digested by the B cell and certain molecules from the antigen are attached to another protein called a class II MHC protein. This antigen-class II MHC protein complex is then presented on the surface of the B cell. Most B cells are activated with the help of other immune cells. When cells such as macrophages and dendritic cells engulf and digest pathogens, they capture and present antigenic information to T cells. The T cells multiply and some differentiate into helper T cells. When a helper T cell comes in contact with the antigen-class II MHC protein complex on the B cells surface, the helper T cell sends signals that activate the B cell. Activated B cells proliferate and can either develop into cells called plasma cells or into other cells called memory cells. Plasma B Cells ​ These cells create antibodies that are specific to a specific antigen. The antibodies circulate in bodily fluids and blood serum until they bind to an antigen. Antibodies debilitate antigens until other immune cells can destroy them. It can take up to two weeks before plasma cells can generate enough antibodies to counteract a specific antigen. Once the infection is under control, antibody production decreases. Some activated B cells form memory cells. Memory B Cells ​ This specified form of B cell enables the immune system to recognize antigens that the body has previously encountered. If the same type of antigen enters the body again, memory B cells direct a secondary immune response in which antibodies are produced more quickly and for a longer period of time. Memory cells are stored in the lymph nodes and spleen and can remain in the body for the life of an individual. If enough memory cells are produced while encountering an infection, these cells can provide life-long immunity against certain diseases. Sources Immune Cells and Their Products. NIAID National Institutes of Health. Updated 2008 October 02.Alberts B, Johnson A, Lewis J, et al. Molecular Biology of the Cell. 4th edition. New York: Garland Science; 2002. Helper T Cells and Lymphocyte Activation.

CASE STUDY 02 Essay Example | Topics and Well Written Essays - 1000 words

CASE STUDY 02 - Essay Example The debt position of the company is more or less the same as that of its peers. 7 Dividend policy forms an integral part of corporate finance. It looks obvious that the company must reward its shareholders by declaring high dividends. But then the question is if the company declares all of its earnings as dividend merely to keep the shareholders happy then this will perhaps retard the future growth prospects. For this reason the companies do not declare all its earnings as dividend but they plough back a certain portion of the earnings in the form of ‘Retained Earnings’. The companies pay a lot of attention to ‘dividend policy’ as a fall may invite the wrath of the shareholders and a rise can come in the way of the growth prospects (Ross, et al., 2008, pp. 590). The dividend payment of FPL Group Inc has been on an upward move for the last ten years. In the year 1984 the company declared a dividend per share of $1.77 that reached the levels of $2.47 in 1993. Unlike the steady rise in the divided the earnings per share (EPS) of the company passed through fluctuations on many occasions but the impact of this was not felt on its dividend payment pattern. In fact in the year 1990 FPL Group incurred a net loss of $391.005 million resulting in a negative EPS of $2.86. But even in this year the company declared a dividend of $2.34. The main incentive of a share issue is that payment of dividend is ‘not obligatory’ i.e. a company pays dividend only when it is able to generate sufficient amount of earnings. But this seems to be inapplicable in the real world as is evident from the case of FPL Group. However it is anticipated by the analysts that the group will either cut dividend or keep it stable at the existing level of $2.48 per share . In 1993 FPL Group maintained a dividend payout ratio of 91% which is the highest as compared to its peers. During this period Duke Power Co. maintained a payout ratio of 68%, Florida

Question 2 Z Essay Example | Topics and Well Written Essays - 1250 words

Question 2 Z - Essay Example However, their distinct differences in terms of formation, structure and ultimate objective distinguishes them. Interest groups are encapsulated within the blanket of pressure groups, which are organizations that are formed on a voluntary basis and are private in nature operating not to form a government but aims at influencing and regulating policies that a government formulates. Pressure groups are either cause groups or Interest Groups (Kenneth 200). Pressure Groups are the groups that aim to influence the government politically, a significant distinctive feature. Interest groups are different from cause groups as they (interest groups) focus on occupational aspects that affect their members; be it issues to do with business, trading, and professional regulations among others. Its main focus revolves around the welfare of those they fight for in occupational capacities. For example, a Teacher’s Union would raise teachers’ grievances to the Ministry of Education concerning delayed salaries. Structures and hierarchical line of power that commands broad edges of issues affecting people with a belief that given a chance they can provide solutions to those problems. They aim to escalate to power and provide political governance to the people and the issues they touch on are much more general than those of interest groups, which are only about occupational issues. As referenced by Caramani (200), adapted from Huckshorns (1984:10), a political party is a group of independent individuals whose aim is to compete in nominations and run for elections in order to escalate to power and have control of the government. Arguably, political parties aim to escalate to power and capture government offices that give it a mandate for governance. According to Caramani (268), Social Movements are collections of individuals with a clearly recognized rival and are involved in a battle and share a central

Code of Ethics Essay Example for Free

Code of Ethics Essay A) Create a business of open and honest communication- Everyone should feel comfortable to speak his or hers mind. No one should be afraid to ask questions or speak up when they think something is wrong. B) Health and Safety- Having a healthy and safe business will make everyone feel comfortable. We should always maintain a healthy environment. Treat the office as if it was you home. C) Gift, Gratuities, and Business Courtesies- We are not allowed to accept money or any gifts over . 00. We are here to help and provide for our clients. Every clients should be treated the same. Certain gifts we can accept like calendars, pens, mugs, and key chains. D) Meals, Refreshments, and Entertainments- We may accept meals, refreshments and entertainment from vendors or clients as long as they are not inappropriately lavish or excessive. E) Accountability- Each person will be responsible for knowing and adhering to the values and standards set forth is this code and for raising questions if we are uncertain about company policy. F) Be Loyal (Confidential and Proprietary information)- Everything in our business will stay in our business. No one should give out personal information on our clients or any of our employees. Confidential and proprietary information includes such things as pricing and financial data, customer names/addresses or nonpublic information about other companies, including current or potential supplier and vendors.

School Examinations Should Be Abolished Essay -- essays research paper

Examinations, as we know it, have emerged to be the main facet of modern education in the ever-changing landscape of academia. In an education infrastructure that is as unpredictable as the clouds, it is somewhat ironic that the system of examinations as a means of judging a student’s ability has prevailed through the years. Every person, in their quest for knowledge, would inevitably encounter numerous modes of examinations throughout the course of their academic journey. As much importance has been attached to it in virtually every academic institutions across the globe, the voices of those who lobby for its eradication are seldom heard, let alone be considered seriously. There are various reasons for policymakers to initiate a rethink of the much-vaunted examination system. I am of the opinion that the time has come for us to abolish this system, a system which has come under fire from multiple sections of the community, particularly the students. As it is, examinations are timed written or oral assessments held at the end of an academic term. It serves to asses a student’s knowledge and comprehension of all the subjects he has studied over the course of the term. Rather than tracking a student’s progress over the course of the term, it judges his/her ability over a handful of written or oral pieces. This is obviously not an accurate indication of one’s progress. Take for example the case of an intelligent and dexterous student who never fails to impress teachers and peers alike in his daily homework and assignments, but fell miserably short of the marks when it comes to the examinations, due to unforeseen circumstances that are not within his influence. These so-called â€Å"unforeseen circumstances† might be familial problems t... ...people society is saturated with presently, unfortunately. On a final note, the time is ripe for all concerned to take a step back and re-assess the real benefits of examinations. It is an exigent circumstance which we are in. As society evolves and technology advances, there is much more to education than simply monotonously memorizing the bare facts of the world. The globalised world of today requires our children to embrace the earth and be innovative. Creativity fuels the innovation engine, with examinations, it is difficult to see how the imaginative aspects of their minds can be developed. One can envision the miserable world our future generations will thrive in, if no steps are taken to keep up with the present day’s needs. We cannot allow ourselves to be entrenched in deeply traditional methods, antiquated values no longer function in this day and age.

Aristotle and Kant Essay

Aristotle and Immanuel Kant have greatly influenced the moral and cultural views, and the way that we perceive the world as a whole now. If Aristotle was only judged solely in terms of his philosophical influence, only Plato is his peer: Aristotle’s works shaped centuries of philosophy from late antiquity through the renaissance, and even today continue to be studied with keen. On the other hand, Kant synthesized early modern rationalism and empiricism, set the terms for much of nineteenth and twentieth century philosophy, and continues to exercise a significant influence today in metaphysics, ethics, political philosophy, aesthetics, and other fields. Aristotle was a Greek philosopher and polymath. His writings cover many subjects including physics, poetry, music, biology and ethics. Together with Plato and Socrates, Aristotle is one of the most important founding figures in Western philosophy. His views on the physical sciences profoundly shaped medieval scholarship and their influence extended well into the Renaissance, although they were ultimately replaced by Newtonian physics. Immanuel Kant was a German philosopher who is widely considered to be a central figure of modern philosophy. He argued that human concepts and categories structure our view of the world and its laws, and that reason is source of morality. His thought continues to hold a major influence in contemporary thought, especially in fields such as metaphysics, epistemology, ethics, political philosophy, and aesthetics. He is seen as a major figure in the history and development of philosophy. German and European thinking progressed after his time, and his influence still inspires philosophical work today.

Time Length And Description For Deferments / Forbearance...

TIME LENGTH DESCRIPTION FOR DEFERMENTS/FORBEARANCE (In order of appearance on Website) †¢ Unemployment Deferment – 12 months per Request (interest accrues monthly) Maximum number allowed: 36 month/life of loan. Has to submit evidence of unemployment benefits/employment agency enrollment/proof of previously granted Unemployment Deferment through another servicer. †¢ Economic Hardship – 12 months per Request (interest does not accrue) Maximum number of months allowed: 36 month/life of loan. Has to submit evidence of receiving state/federal assistance (SNAP, SSI, Medicaid/Medicare, TANF), working full time and under 150% of the Poverty Line, monthly Federal loan payments cause â€Å"Hardship†, proof of Economic Hardship with another servicer, volunteer in the Peace Corps. †¢ Mandatory Forbearance – 6 months per Request (interest accrues monthly ) Maximum number of months allowed: 36 month/life of loan. Has to submit proof of taxable income/total monthly income/total amount of monthly payments on each Title IV loans. Forbearance can be back-dated if the account is past due, but cannot be applied if the account has $0.00 in principal due. †¢ General Forbearance – 6 months per Request (interest accrues monthly) Maximum number of months allowed: 36 months/life of loan. The Borrower has to submit a reason for the forbearance request, example; financial difficulties/change in employment/medical expenses/other (must explain situation). Forbearance can be back-dated if the account is