Mechanisms of Response essays

Mechanisms of Response essays The human body is built with its own immunity system. It provides defenses against foreign objects in the body and prevents disease. Specific diseases have a specific reaction- the immune system has a mechanism of response for each particular foreign substances. A foreign molecule that draws specific response lymphocytes is called an antigen; antigens are the molecules that are rejected by the body. Antigens are inclusive of molecules that belong to viruses, bacteria, fungi, protozoa, and parasitic worms. However, antigenic molecules can also be found on the surfaces of foreign materials such as pollen and transplanted tissue (as in the situation of a skin graft.) A skin graft is a patch of skin that is surgically removed from one part of the body and transplanted to another. It replaces tissue that has been destroyed or creates new tissue where none exists. One way that an antigen begins an immune response is by activating B cells to secrete proteins called antibodies. The term antigen is a contraction of anti-body-generator. Each antigen has a particular molecular shape and stimulates certain B cells to secrete antibodies that interact specifically with it. In fact, B and T lymphocytes even distinguish among antigens with molecular shape s that are only slightly different. So, in contrast to the nonspecific defenses, the immune system targets specific invaders. B cells and T cells can recognize specific antigens by their plasma membrane-bound antigen receptors. On B cells, these are actually transmembrane versions of antibody molecules and are often referred to as membrane antibodies. The antigen receptors on a T cell, called T cell receptors, are structurally related to membrane antibodies, and they recognize antigens just as specifically; contrary to antibodies, T cell receptors are never produced in a secreted form. Just one T or B cell can hold about 100,000 receptors for antigen, all with exactly the same specificity...

The Phonogram WH

The Phonogram WH The Phonogram WH The Phonogram WH By Maeve Maddox A reader commenting on Wile vs While wrote: Modern speakers and writers have a problem with W words such as while and wile (another example: whale, wale, and wail) because there is no longer a distinction made between the way wh and w are pronounced. Not all American speakers distinguish between the sounds of whine and wine, but many still do. There are advantages to teaching the distinction, even in regions where the difference has been lost in the local dialect. Wh represents the sound one makes when blowing out a candle: [wh]. The number of English words that begin with wh is not large, and even speakers who distinguish between the initial sounds of Wales and whales do not pronounce wh as [wh] in every word that begins with the wh spelling. For speakers of dialects that still distinguish between the pronunciation of which and witch, the following words begin with the aspirated sound [wh]: whack whale wharf what wheat wheel wheeze when where whet whether which whiff Whig while whim whimper whip whirl whisk whisker whisky whisper whit white whoop why In the following words, the spelling wh represents the sound [h]. who whom whole whose wholly whore What linguists call the â€Å"wine-whine merger† is no doubt destined to prevail in the United States. Nevertheless, teaching the aspirated sound of wh is an aid to spelling mastery. Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Spelling category, check our popular posts, or choose a related post below:12 Types of LanguageWhat is Dative Case?50 Plain-Language Substitutions for Wordy Phrases

Health and Safety Legislation Research Paper Example | Topics and Well Written Essays - 3750 words

Health and Safety Legislation - Research Paper Example Regardless of the number of employees, all industrial operations have to be monitored by appropriate strategies and procedures. Nature of work is a significant factor that determines the range of health and safety measures required in the industry. Whenever high-risk factors are identified, an employer has to seek the advice and permit of the responsible manager regarding the required precautions. This permit to work practice is mandatory when an employee gets into an unusual and risky job. Besides permit to work, there are some more obligatory safety measures such as isolation, monitoring equipment and protective clothing and equipment that may control or prevent risks in the workplace. According to Hughese & Ferrett (2005 p.82), the permit to work procedure is a specialized type of safe system of work for ensuring that potentially very dangerous work is done safely. In fact, this is written consent from a responsible person which ensures that adequate precautions have been taken to avoid or control risk. The authorized individual usually considers certain factors before issuing a permit like the nature of work, equipment involved in the work, the ability of the authorized worker, and if he needs training, possible hazards and the steps taken to overtake them (Hughese & Ferrett p.83). Most of the industrial accidents are the result of negligence and paucity of awareness about the risk factors and safety measures. Industrial operations require a permit when there is a chance of any of the following or similar risks; mechanical or natural toxic, electric shock, fall from a height, radiation, suffocation, chemical exposure, explosion, inflammable substances etc. Howeve r, according to the Guidelines on Permit to Work Systems (Jan.1993), simply a permit does not reduce risk; instead, it is an essential part of a system which determines how that work can be carried out safely.

Profit Implications of Malware Annotated Bibliography

Profit Implications of Malware - Annotated Bibliography Example A computer worm refers to a self-replicating computer program. It relies on computer network to send copies of itself to other computers on the network in an automatic manner. Worms are known to exploit a zero-day vulnerability that allows them to execute their copies within the same network (Effects of Malware Infections: Avoid the Dangers of Malware Programs ). There are several types of worms these are: The internet Relay Chat worms that exploit the Internet Relay Chat (IRS) unlike the Instant messenger worm that exploit the IM channel. The web or internet worm spreads via user access to a web page, file transfer protocol or by use of other internet sources. We also have the file-sharing (Peer-to-peer) worm that copies itself into a shared folder, it then use its peer-to-peer mechanism to make its existence known with the hope that a user will download it. As for the flash form these refers to the theoretical worms that spread within seconds upon activation to all vulnerable hosts on the internet. A Trojan horse is a non-self-replicating type of malware that tends to perform normal beneficial functions for the user though it facilitates unauthorized access to the user’s computer system. Recently Trojan horse is released as payloads by computer worms that give the attackers full control of the victims’ personal computer (Effects of Malware Infections: Avoid the Dangers of Malware Programs ). There are several factors that make Trojans dangerous, first of all Trojans are not visible in the traditional process viewer. including windows and task managers, this coupled with the fact that most virus and Trojan scanners find it difficult detecting the Trojan code. Also the Trojan code is very difficult to unload hence making it hard cleaning it. The most common type of Trojan is the proxy Trojan that once it attacks the victims computer it turns it into a proxy server (Zombie) which then operates on behalf of the remote attacker. This makes it even more difficult traci ng the attack to the attacker as the trail often leads to the victim in most cases. A rootkit is a software system that is composed of several of one or more computer programs that are designed to hide the fact that a computer system has been compromised. Usually an attacker

Alcoholic Beverage Essay Example for Free

Alcoholic Beverage Essay Alcoholism is a chronic problem that includes difficulty in controlling drinking, having to drink consistently to get physical independence, being preoccupied with alcohol, and continually using alcohol regardless of problems it causes (Brick, 2004). Alcohol should not be legal in U. S. because it is impacts negatively on health, family, community and on a person’s education. Alcohol drinking is like taking a drug. It is a form of drug addiction and drug abuse. Alcoholism is a worldwide problem that affects many people. Drinking alcohol has negative short and long term effects. Alcoholism has been associated with adverse effects on health, family, community, and education (Marshall, 2000). However, the effects on a person depends on particular factors such as how often and how much alcohol is taken, a person’s age, gender, when a person begun drinking and how long they have been drinking, their health, and family history (Begleiter amp; Kissin, 1996). It is in this regard that alcohol should not be legal in the United States. Alcohol is addictive, and people become addicts end up spending a lot of money on alcohol. It means that when they spend all the money they have on alcohol, they forget their families, and are not able to support the community in anyway. Some resort to stealing to sustain their drinking habit. Alcohol addicts sometimes engage in robbery acts to get the money for drinks. Community becomes at risk of destruction with excessive alcohol consumption allowed. When many people engage in excessive consumption of alcohol, education becomes at risk. People drop out of school, and illiteracy level increase in the community. In addition, the progress and development of any community depends on the health of its people. Therefore, when alcohol puts the health of its members at risk, community suffers in the long run. Alcohol affects both female and male differently. Men who consume alcohol, daily have an increased risk of health risks. Such men can experience cancer and heart disease in the long-term and low energy to sexual difficulties in the short-term (Brick, 2004). Men are more likely to suffer from liver cirrhosis, and have higher chances of being diagnosed with high blood pressure. Nearly 26. 6% of deaths among men of between 16 and 24 years old can be attributed to alcohol consumption. Men tend to be more dependent of alcohol (Marshall, 2000). Drinking too much alcohol damages a person’s body organs such as liver, brain, stomach, heart,and intestines. Brain is adversely affected because the brain cells die leading to loss of memory, learning difficulties, brain disorders, confusion, and problems with attention (Blane amp; Leonard, 1999). Liver is highly affected because of the great possibility of developing cancer in the liver, throat and mouth. The stomach may also acquire ulcers. Long-term drinking has also been linked to stroke and heart failure. The nervous system can also experience damage leading to behavioral and physical problems (Dasgupta, 2011). These problems affect health, family, community, and education in the long-term because of expenses associated with alcohol consumption, and possible treatment measures. Alcohol poses many effects on the body such as fertility. It reduces levels of testosterone. As a result, it could decline sperm quantity and quality, and lead to loss of libido. Alcohol is toxic to the testicles, and affects hormones. It could hamper production of sperms, hinder them from developing properly, and slow their movement towards the egg. Alcohol can also limit the liver from metabolizing vitamin A properly. It also depresses the nervous system, and could result in difficulty in getting and keeping erection (Peters, 2008). Many young adults do not realize that alcohol has a fattening effect. Alcohol can reduce the amount of fat that the body burns for energy. The human body makes several attempts to eliminate alcohol 1 / 3 very fast as it cannot remain in the body for storage. The process takes priority over nutrient absorption and burning of fat. In the long-term, there could be a serious damage in the appearance. Other effects include loss of hair in the body, breast enlargement, and withering of testicles (Dasgupta, 2011). Alcohol has also been associated with worsening of skin disorders such as rosacae. Rosacae skin disorder is responsible for expansion of blood vessels in the face making it redder. Heavy drinking can cause the appearance of pus spots and red bumps. It has also been linked to inflammation, pain and swelling in the joints. The effect is common among men of between 30 and 60 years old (Hannigan, Spear, Spear amp; Goodlett, 1999). As mentioned earlier, heavy drinking increases the chances of heart disease, liver damage, bone disease, cancer, anxiety and depression, and type II diabetes. Heavy consumption of alcohol also caused inflammation on the pancreas and irritates stomach. These effects indirectly affect family, community and education (Peters, 2008). Women are not safe from alcohol either. The body of women takes much time to process alcohol compared to men. Women feel more effects of alcohol than men even when they drink the same amount. The fertility of women is at risk with heavy consumption of alcohol. Women are high risk of acquiring breast cancer, and adverse impacts of the menopause. Women are advised in several studies to avoid alcohol when trying to have a baby. Alcohol disrupts menstrual cycle in women, and limits their chances of conceiving. These are bad effects on the body, and not good for family and community in general. Therefore, alcohol should not be legal in the United States (Hannigan, Spear, Spear amp; Goodlett, 1999). While drinking less alcohol may make one look good, heavy consumption causes bad skin, tired eyes, and weight gain for both female and male. It also interferes with people’s sleep. Heavy consumers of alcohol often wake up and feel like they have not had enough rest. Alcohol dehydrates the body and skin. It deprives the skin of certain vital nutrients and vitamins. Hence, it is not good for health. Alcohol is also responsible for much divorce among couples due to fights in the family, and lack of finances for family upkeep (Dasgupta, 2011). Alcohol is depressant. It means that alcohol calms people down, and slows down some body organs. With only 0. 05% level of blood-alcohol, a person begins getting dulled judgment, and his or her inhibitions get released. They then become clumsy and start having slurred speech with only a 0. 10% blood-alcohol level. At 0. 30% level of blood-alcohol, one nearly becomes unconscious. Any addition after that becomes extremely dangerous since at 0. 45%, one can get into a coma. Brain shuts down from 0. 70% and stop controlling the heart, breathing, and one may end up dead. Other short-term effects include blurred vision, blackouts and insomnia. These can lead to injuries, accidents, and even death. Drinking alcohol also causes hangover in the next morning, which is associated with nausea, headaches, heartburn, fatigue, thirst, and dizziness. There are many side effects of alcohol (Peters, 2008). Conclusion In conclusion, consumption of alcohol should be reconsidered in U. S because of its adverse effects on health, family, community, and education. Alcohol should only be taken when necessary. The side effects are adverse and continue to destroy people across the world. Therefore, alcohol should not be legal in the United States because it is impacts negatively on health, family, community and on a person’s education. References Begleiter, H. , amp; Kissin, B. (1996). The pharmacology of alcohol and alcohol dependence. New York: Oxford University Press. Blane, H. T. , amp; Leonard, K. E. (1999). Psychological theories of drinking and alcoholism. New York [u. a. : Guilford Press. Brick, J. (2004). Handbook of the medical consequences of alcohol and drug abuse. New York: Haworth Press. Dasgupta, A. (2011).

Platos Repulic, book V Essay -- essays research papers fc

ABSTRACT: This paper discusses the viability of certain aspects (the sex lottery) of Plato's Republic, book V. It is college level 'A' paper. Book V of The Republic finds Socrates explaining the practical details necessary in the creation of an ideal polis. He proposes a system for population control and human eugenics based on a lottery of sorts which will determine who will mate with whom and when. The lottery is â€Å"rigged† by the rulers in order that the best of the â€Å"herd† will mate much more frequently than others. However, only the rulers of this society will know the lottery is rigged. This system will presumably assure that children will be conceived as the result of reason, not irrational behaviors such as love or lust, and will produce the best possible future generations (Plato 458d – 460c). I argue that Plato’s lottery would not have worked in his time, nor would it work now because the desire to propagate was and still is a human instinct propelled by passion, not something that can simply be reasoned away. While Plato proposed that licentiousness would be forbidden and matrimony given the highest degree of sanctity (458e), I do not think that would be enough to stop a massive rise in sex crimes and passionate affairs. Instead of a just society, Plato’s proposal would have created one of fear, self-doubt and lack of trust in the government and is not something I would advocate implementing. While we can never really know how this utopia would have â€Å"played out† in Plato’s time, the negative effects on a society when passions are forcibly controlled can be illustrated in a modern sense by the Catholic Church and our penal system. Plato wrote that guardians would be â€Å"drawn together by a necessity of their natures to have intercourse† (458d) and yet, their sexual interludes should be limited by the use of the lottery. It is important to point out that since reliable and accessible birth control is a recent luxury, Plato was not simply advocating for selective child birth, he was talking about abstaining from heterosexual sex unless you â€Å"won† the lottery. I don’t think Plato’s lottery system would have worked out as well as he envisioned. When the less desirable of the population were consistently â€Å"unlucky† and unable to propagate year after year, what would have happened to them psychologically? Given that copulation was to be an honor bestowed upon... ...or other punishments. Whether restraint of sexual instincts are willingly accepted or forced upon a community, the results can lead to a decidedly non-ideal situation. By looking at some modern examples, I have shown how human desire can, and often does, override reason and the law even when faced with community imposed consequences or dire punishments. While current society differs greatly from Plato’s Greece, people are still people and human instinct existed then just as it exists today. People who are denied the ability to choose if and with whom they can have sex are liable to become irrational or turn to violent means to reach that end, regardless of the era in which they live. In Plato’s ideal society these unsanctioned actions could have lead to an increased level in the public’s fear for their physical safety. Individuals consistently denied by the rulers to copulate might develop self-worth issues and finally, a pin-prick of imperfection in this utopian society may be discovered by those who are forbidden from enjoying physical relations with those they desire or love. Works Cited Plato, The Republic. Trans. Benjamin Jowett. New York: Barnes & Noble Books, 2004.

Analysis of the Text “the Time-Sweepers” by Ursula Wills-Jones

Analysis of the text â€Å"The Time-Sweepers† By Ursula Wills-Jones The following short story is about time-sweepers and lost time. They are people who sweep up all the time that is lost or wasted. They are invisible, but sometimes they can be noticed. They carry a broom, a mop and a big dustpun. The time-sweepers are hard-working. They work every day and are never sick. The lost and wasted time is packed and recycled.But not every type of time can be recycled, the most poisoned time is buried in a tank underneath a disused army base. The rest of the time can be sold to the people who need it or distributed to good causes or emergency situations. The full text is built on the conflict between people who waste time and people who sweep up all the time that is lost and wasted. Ursula Wills-Jones idealizes the time-sweepers and ridicules people.The author uses the stylistic device of climax in order to describe different types of time wasting: the man who has waited so long to pr opose to his girlfriend; the woman who has spent thirty-five loathed years in an estate agents, dreaming of opening a florists. The author refers to the stylistic device of hyperbole in order to laugh at the people who waste time: the time-sweeper will pass straight by the desk of the woman who is reading a holiday catalogue under the desk, poring over photos of tropical beaches.They will pass by the next desk, where a man is enjoyably wondering what his mother-in-law looks like naked, and stop by the desk of the young man who is counting every minute, and loathing the hours. The author creates a constant presence of time sweepers. The reader feels that they are everywhere: in the railway station, in the office, at your desk. The time-sweepers are hard-working; they don’t like to rest because there is so mush wasted time after holidays: it takes them around three weeks to resume normal service†¦

Importance of Handwash

Image description. Better Health Channel logo End of image description. Handwashing – why it's important A  number  of  infectious  diseases  can  be  spread  from  one  person  to  another  by  contaminated  hands, particularly  gastrointestinal  infections,  influenza  and  hepatitis  A. Washing  your  hands  properly  can help  prevent  the  spread  of  the  organisms  that  cause  these  diseases. Some  forms  of  gastroenteritis  can  cause  serious  complications,  especially  for  young  children,  the elderly,  or  those  with  a  weakened  immune  system. Drying  your  hands  properly  is  as  important  as washing  them.Ima ge des crip When to wash your hands You  should  wash  your  hands  thoroughly: †¢ †¢ †¢ †¢ †¢ †¢ †¢ †¢ †¢ Before  preparing  food Before  eating Between  handlin g  raw  and  cooked  or  ready-to-eat  food After  going  to  the  toilet  or  changing  nappies After  smoking After  using  a  tissue  or  handkerchief After  handling  rubbish  or  working  in  the  garden After  handling  animals After  attending  to  sick  children  or  other  family  members. How to wash your hands properly To  wash  hands  properly: †¢ †¢ †¢ †¢ †¢ †¢ †¢ †¢ †¢ †¢ Wet  your  hands  with  warm  water.Apply  one  dose  of  liquid  soap  and  lather  (wash)  well  for  15–20  seconds  (or  longer  if  the dirt  is  ingrained). Rub  hands  together  rapidly  across  all  surfaces  of  your  hands  and  wrists  to  he lp  remove  dirt and  germs. Don’t  forget  the  backs  of  your  hands,  your  wrists,  between  your  fingersà ‚  and  under  your fingernails. If  possible,  remove  rings  and  watches  before  you  wash  your  hands,  or  ensure  you  move the  rings  to  wash  under  them,  as  microorganisms  can  exist  under  them. Rinse  well  under  running  water  and  make  sure  all  traces  of  soap  are  removed,  as  residues may  cause  irritation.Pat  your  hands  dry  using  paper  towels  (or  single-use  cloth  towels). Make  sure  your  hands are  thoroughly  dry. Dry  under  any  rings  you  wear,  as  they  can  be  a  source  of  future  contamination  if  they remain  moist. Hot  air  driers  can  be  used  but,  again,  you  should  ensure  your  hands  are  thoroughly  dry. At  home,  give  each  family  member  their  own  towel  and  wash  the  towels  often. Handwashing  Ã ¢â‚¬â€œÃ‚  why  it's  important Page  1  of  4 How  to  wash  and  dry  hands  with  liquid  soap  and  water  (Click  to  open  larger  image) Use warm waterCold  water  is  better  than  no  water  at  all  for  a  one-off  hand  wash,  but  should  not  be  used  for routine  handwashing. Soap  lathers  (soaps  up)  better  with  warm  water. The  active  ingredients  on the  surface  of  the  soap  are  released  more  easily,  making  them  more  effective  in  cleaning  your hands  of  dirt,  grease  and  oils,  without  stripping  away  the  natural  oils  in  your  skin. Using  cold  or  hot water  can  also  damage  the  skin’s  natural  oils. Over  time,  this  can  cause  dermatitis. Soap is important Soap  contains  ingredients  that  will  help  to: †¢ †¢ à ¢â‚¬ ¢ Loosen  dirt  on  your  hands.Soften  water,  making  it  easier  to  lather  the  soap  over  your  hands. Rinse  your  hands,  leaving  no  residues  to  irritate  and  dry  your  skin. Soaps  can  have  different  pH  Ã¢â‚¬â€œÃ‚  they  may  be  neutral,  slightly  alkaline  or  slightly  acidic. That’s  why some  soaps  irritate  some  people  and  not  others. Perfumes  in  soap  can  be  another  reason  why some  people  have  skin  reactions. Liquid soap is best Handwashing  Ã¢â‚¬â€œÃ‚  why  it's  important Page  2  of  4 Generally,  it  is  better  to  use  liquid  soap  than  bar  soap,  particularly  at  work.The  benefits  of  liquid soap  include: †¢ †¢ †¢ †¢ Hygiene  Ã¢â‚¬â€œÃ‚  it  is  less  likely  to  be  contaminated. Right amount  Ã¢â‚¬â€œÃ‚  liquid  soap   dispensers  do  not  dispense  more  than  required  (more  is  not better). Less waste  Ã¢â‚¬â€œÃ‚  it’s  easier  to  use,  with  less  wastage. Drop-in  cassette  dispensers  use  all  the soap. Saves time  Ã¢â‚¬â€œÃ‚  liquid  soap  dispensers  are  easy  and  efficient  to  use. Disposable  liquid  soap  cassettes  are  convenient,  as  you  do  not  have  to  wash  and  thoroughly  dry the  refillable  container  before  refilling. If  you  want  to  use  refillable  cont

Acid Anhydride Definition - Chemistry Glossary

Acid Anhydride Definition - Chemistry Glossary Acid Anhydride Definition: An acid anhydride is a nonmetal oxide which reacts with water to form an acidic solution. In organic chemistry, an acid anhydride is a functional group consisting of two acyl groups joined together by an oxygen atom. Acid anhydride also refers to compounds containing the acid anhydride functional group. Acid anhydrides are named from the acids that created them. The acid part of the name is replaced with anhydride. For example, the acid anhydride formed from acetic acid would be acetic anhydride. Sources IUPAC, Compendium of Chemical Terminology, 2nd ed. (the Gold Book) (2006).Nelson, D. L.; Cox, M. M. (2000). Lehninger, Principles of Biochemistry, 3rd Ed. Worth Publishing: New York. ISBN 1-57259-153-6.Panico R., Powell W.H., Richer J.C., eds. (1993). Recommendation R-5.7.7. A Guide to IUPAC Nomenclature of Organic Compounds. IUPAC/Blackwell Science. pp. 123–25. ISBN 0-632-03488-2.

Writing a Good Biology Research Paper

Writing a Good Biology Research Paper Biology research papers can be very challenging for many students. Biology is such a broad field and the range of topics for research papers is vast. Biology research papers are not the hardest scientific papers to write but they do take time. There are many sources available for your biology research papers. Actual sources are needed because you cannot use your thoughts or feelings in your biology research paper. You need to answer a scientific question or hypothesis supported by material found from texts, experiments, and journals. Essentially a biology research paper would be based on some form of plant or animal life. A more basic biology research paper would discuss some basic concepts found in science. Questions can be answered on mitosis, meiosis, explain experiments you conducted in class, investigate the differences between sexual and asexual reproduction, investigate cell division, describe single cell life forms and how they evolved into multiple cell life forms, discuss Darwin and the evolution theory. There are many topics. It is a matter of finding one that interests you. Supporting material can come from books, textbooks, scientific journals, class notes, experiments conducted even some online sources. Illustrations and graphics can also help to present information that is difficult to explain in words. Many people respond better to pictures as means of illustration. Graphs and graphics can help cement a point to your audience. Assigned to write a research paper? Here is a great  guide to the research paper writing: How to Write a Research Paper It is important that you understand the assignment given before you choose your biology research paper topic. There are often specific guidelines and questions that must be answered completely independent of the chosen topic. Plan your biology research paper, make sure the structure is correct and that you have access to the appropriate amount of supporting material. The most important rule, try not to procrastinate! A biology research paper that is written at the last minute does not have the content or supporting materials to be rewarded with a good mark. Biology research papers take some time so don’t leave it to the last minute. Contact our support team if you have questions or need assistance in writing your research paper in biology or place an order.

Gun Control Laws and Violent Crime Rates do not Correlate Research Paper

Gun Control Laws and Violent Crime Rates do not Correlate - Research Paper Example Global evidences have long been presented as reason of the statement, â€Å"more guns mean more deaths†. Countries like Britain, where gun control laws are implemented, violent crime rates are low. Unluckily, this notion is not true to all countries. In fact, the United State’s crime violence rates intensified throughout 1980s and 1990s. After the undertaken assassination of President Reagan, gun control bill became the agenda of the Congress. Further, Brady Law decrees a period of 72 hours of waiting to buy handguns and the Violent Crime Control and Law Enforcement Act, which bans the production, sale, or ownership of 19 types of semi-automatic weapons. The justification of gun control consists of arguments that ownership or availability of guns is correlated with high violence rates. Thus, gun control laws would be the solution in reducing crimes. This resulted to serious debates.