Tankless water heaters Essay Example | Topics and Well Written Essays - 2500 words

Tankless water heaters - Essay Example Adomatis (2010) predicts that new homes buyers â€Å"may be willing to pay for the cost of the energy efficient items in green construction† as a means of reducing energy expenses. Not only can energy efficiency building requirements save money, but energy efficiency can also save homeowners money by heating their homes in the winter and cooling their homes in summer with less power and resources. Energy Star is program jointly operated by the U.S. Environmental Protection Agency and the US Department of Energy. The program is designed to help Americans reduce the cost of energy and at the same time protect the environment via the use of â€Å"energy efficient products and practices† (Energy Star, n.d.). Though ENERGY STAR ® program serves as a trusted source of voluntary standards and unbiased information, federal and state policies provide additional sources for consumers and organizations to adopt other energy-efficient products and practices that further reduce gr eenhouse gases (GHGs). The purpose of this memo is to propose a code enforced method for improving appliance efficiency via the mandatory installment of Tankless Water Systems only in the construction of new dwelling houses. ... i. The installation of traditional hot water heaters (reserve tank) systems in the construction of all new homes will be prohibited. b. Natural gas (or propane, with be the primary means of energy used for the tankless water systems. i. In the event natural gas installation is not practicable, electric tankless units with an EF rating of >92 may be used as an alternative. c. Tankless systems can include multiple installations that would then be placed directly near a hot water demand source. However, this must not be installed in any combination with conventional storage tank water heater systems. An example would be a booster heater for augmenting a traditional hot water heater system. d. Solar or other heat exchange technologies that utilize on-demand heating for hot water are also included with this code proposal. Reasons for the Change in Texas Building Code The minimum allowable efficiency for residential water heaters is regulated by federal standards. New amended federal stand ards to take effect on April 16, 2015 are detailed in the Energy Policy and Conservation Act (42 U.S.C. 6295(o)(3)(B)) (See Table 1). Federal initiatives have been implemented to further promote green initiatives and are detailed in the Executive Order 13423 and 13221. These Executive Orders, issued in 2009, require federal agencies to acquire energy-efficient products in the acquisition of commercially available, off-the-shelf products for goods and services. If the same practices were applied to the residential sector, further gains to maximize green initiative savings would be more beneficial for the public as a whole. Table 1 Amended Energy Conservation Standards for Residential Water Heaters Source: Energy Conservation Program: Energy Conservation

Animal Senses Biology magnetoreception mechanism on Migratory Birds Essay

Animal Senses Biology magnetoreception mechanism on Migratory Birds - Essay Example Birds have various times of migration. Some birds migrate during the day like swallows and crows, while some migrate at night such as warblers, cuckoos, wild fowls and woodpeckers, as well as most songbirds (Engels 1). Stimuli such as internal body clocks or subtle weather changes cause these birds to migrate, and this ability can be explained by a phenomenon called magnetoreception, which is the ability of some organisms to detect the Earth’s magnetic field in perceiving direction, altitude or location (Solov'yov 40). The Earth’s magnetic field can be detected through various mechanisms such as chemical, electrical and mechanical means, and any of these stimuli can be converted into a molecular signal like a light-stimulated or photochemical reaction in the retina, which can then be recognized and perceived by magnetoceptive organisms like birds and insects (41). Hypotheses in the mechanisms of magnetoreception in birds There are various mechanisms hypothesized for mag netoreception to occur in birds, and one of these is the phenomenon involving a chemical compass where chemical reactions occur involving the transitions of electrons between high and low energy configurations or spin states, influenced by the Earth’s magnetic field (Rodgers 353). ... The amount of products from this reaction and the length of the half-life time of the radical base pair would depend on the strength of the detected magnetic field. The strength of the magnetic field determines the amount of radical base products and their length of half-life, and their linear relationship can be used to determine the strength of the magnetic field (Ritz 135; Rodgers 353). Thus, the stronger the magnetic field, the radical base pair mechanism would be producing more molecules with unpaired electrons, which in turn keeps the bird in its intended direction. These reactions occur in the photoreceptor region of the bird’s eye, helping the birds detect the strength of Earth’s magnetic field through radical base pair mechanism. The radical spinning is explained by hyperfine interactions, and these happen when there is a coupling between the magnetic moments of the unpaired electron and its atomic nucleus (Ritz 135). The interchanging conversions between the s inglet state and the triplet state is a process whose frequency is determined by the strength of the hyperfine reactions. This system is not only influenced by the intensity but also by the direction of the field, which makes it act like a compass (136). The tendency of one component of hyperfine reaction to be strong towards one direction only determines the interchanging conversion rate of the S and T state. Thus the effects of the magnetic field would be depending on the direction of the magnetic field with respect to the alignment of the radical pairs. These are the mechanisms by which birds are able to travel at night. Photoreceptor mechanisms in birds Birds have two types of light receptors in their eye: night vision

Concealed Carry Laws Essay Example | Topics and Well Written Essays - 1250 words

Concealed Carry Laws - Essay Example Sub-point 1: Crime rates are lower in states with concealed gun carry laws. Sub-point 2: Crime rates have not worsened in states with concealed gun carry laws. Main Point 2: Banning firearms does not reduce crimes. Sub-point 1: No positive association between gun ownership and violence. Sub-point 2: Studies do not show that gun control laws have reduced crimes. Main Point 3: Cross country history and experience show allowing concealed weapons carry does not make societies less peaceful. Sub-point 1: Among countries, gun control laws are not associated with peace. Sub-point 2: Gun ownership and murder rates are not correlated across countries. Conclusion Based on evidence, there is good basis not to reverse the gains American society has made in allowing the carry of concealed weapons for Americans to protect themselves. The advances in concealed weapons laws have been beneficial and not dangerous for America. Concealed weapon carry laws: Are they beneficial or dangerous for America? Introduction A center known for its being vocal against laws allowing the carry of concealed weapons, the Violence Policy Center, has pointed out that the â€Å"gun lobby’s priority has been establishing and expanding state laws that allow the carrying of concealed handguns by private citizens† (2009, p. 3). According to the center (2009, p. ... The Violence Policy Center has been very concerned and identified three key data on why concealed weapons carry laws are dangerous for America. First, according to the Violence Policy Center (2009, p. 4), â€Å" over the two-year period May 2007 through 2009, concealed handguns permit holders have slain seven law enforcement officers resulting in criminal charges or the suicide of the shooter.† Second, again according to the Violence Policy Center (2009, p. 4), â€Å"concealed handgun permit holders have slain at least 43 private citizens resulting in criminal charges or the suicide of the shooter.† And, third, according to the Violence Policy Center (2009, p. 4), â€Å"in six of the 30 incidents (20 percent), the concealed handgun permit holder killed himself, bringing the total fatality count to 56.† The Violence Policy Center’s concern for violence in America, particularly murders or homicide and suicide is certainly laudable. Indeed, it is the duty of today’s generation to see to it that every citizen is out of harm’s way. Indeed, it is an obligation of today’s generation of Americans to keep society safe and peaceful. Unfortunately, however, the basis for the Violence Policy Center’s concerns against the concealed weapons laws and the attribution the organization places on concealed weapons laws as responsible for the incidences of violence is anecdotal and unscientific. The Violence Policy Center’s arguments are like arguments that because consulting a doctor or being confined in a hospital have been associated with illness or death then society must ban doctors and hospitals because many people have died when they have

Offshoring Essay Example | Topics and Well Written Essays - 2500 words

Offshoring - Essay Example As the jobs of the first world make their way to the developing regions of the third world, the forces of globalization have had many unintended consequences. The loss of manufacturing jobs in the countries of the world and their movement to the lower paying developing "third world" has restructured the world economy. This brief assignment will explore the globalization phenomenon with an eye to outsourcing and the changes dynamics of the global economic community. We will utilize a case analysis and explore two countries which have embraced free trade and economic growth as a haven for outsourcing. China represents a unique blend of authoritarianism and capitalism leading to sustained and pronounced economic growth in one of the largest - and growing - economies in the world. Mexico represents a controversial source for many American jobs. In addition to a cross-comparative analysis of these outsourcing "source" countries, we will address criticisms of the globalization phenomenon i ncluding the rise of protectionism as a response to the flight of jobs overseas. Globalization, as it exists today, rests largely on the shoulders of neoliberal economics and the global entrenchment of capitalism as the dominant economic system in the world. ... sely popular book The World is Flat (2005), describes offshoring/outsourcing as an integral component of the worldwide spread of capitalism and the global division of productive labor. According to Friedman, outsourcing is primarily done in response to keep costs low and restructuring ones' labor force in order to keep production costs at a minimum. Accordingly, while a non-skilled manufacturer in Illinois can expect to earn a minimum of $14 a hour, in a country such as India could earn less than a $1 an hour. Thus, companies who seek to maintain their competitive advantage and keep cost low, ship their productive facilities overseas where costs are significantly lower. There are also important tax advantages to outsourcing jobs overseas and as we shall see in our case analysis of China below, companies can often expect certain tax benefits when utilizing productive labor in the developing world (Friedman 2005; Bendor-Samuel 2005). Case Study: China China has become the source for literally thousands of jobs, particularly in the manufacturing sector, which used to employ people in the developed countries of the Western world. Despite these early years of anti-capitalism in the wake of the Chinese Revolution, China has cautiously embraced economic liberalism and a capitalist economic orientation, albeit with strong authoritarian tendencies. China today has the 4th largest economy in the world behind the United States, Japan and Germany, estimated at $2,645 billion per year. With a population of more than 1.3 billion, China remains a largely rural country with 43% of its labor force employed in agriculture with another 25% in industry and 32% in the service sector. Industry, however, has driven the economic growth of this country which represents 49% of the

Concealed Carry Laws Essay Example | Topics and Well Written Essays - 1250 words

Concealed Carry Laws - Essay Example Sub-point 1: Crime rates are lower in states with concealed gun carry laws. Sub-point 2: Crime rates have not worsened in states with concealed gun carry laws. Main Point 2: Banning firearms does not reduce crimes. Sub-point 1: No positive association between gun ownership and violence. Sub-point 2: Studies do not show that gun control laws have reduced crimes. Main Point 3: Cross country history and experience show allowing concealed weapons carry does not make societies less peaceful. Sub-point 1: Among countries, gun control laws are not associated with peace. Sub-point 2: Gun ownership and murder rates are not correlated across countries. Conclusion Based on evidence, there is good basis not to reverse the gains American society has made in allowing the carry of concealed weapons for Americans to protect themselves. The advances in concealed weapons laws have been beneficial and not dangerous for America. Concealed weapon carry laws: Are they beneficial or dangerous for America? Introduction A center known for its being vocal against laws allowing the carry of concealed weapons, the Violence Policy Center, has pointed out that the â€Å"gun lobby’s priority has been establishing and expanding state laws that allow the carrying of concealed handguns by private citizens† (2009, p. 3). According to the center (2009, p. ... The Violence Policy Center has been very concerned and identified three key data on why concealed weapons carry laws are dangerous for America. First, according to the Violence Policy Center (2009, p. 4), â€Å" over the two-year period May 2007 through 2009, concealed handguns permit holders have slain seven law enforcement officers resulting in criminal charges or the suicide of the shooter.† Second, again according to the Violence Policy Center (2009, p. 4), â€Å"concealed handgun permit holders have slain at least 43 private citizens resulting in criminal charges or the suicide of the shooter.† And, third, according to the Violence Policy Center (2009, p. 4), â€Å"in six of the 30 incidents (20 percent), the concealed handgun permit holder killed himself, bringing the total fatality count to 56.† The Violence Policy Center’s concern for violence in America, particularly murders or homicide and suicide is certainly laudable. Indeed, it is the duty of today’s generation to see to it that every citizen is out of harm’s way. Indeed, it is an obligation of today’s generation of Americans to keep society safe and peaceful. Unfortunately, however, the basis for the Violence Policy Center’s concerns against the concealed weapons laws and the attribution the organization places on concealed weapons laws as responsible for the incidences of violence is anecdotal and unscientific. The Violence Policy Center’s arguments are like arguments that because consulting a doctor or being confined in a hospital have been associated with illness or death then society must ban doctors and hospitals because many people have died when they have

Economics Aeropostale Essay Example for Free

Economics Aeropostale Essay In March 2007, AÃ ©ropostale was accused of infringing a patent owned by Card Activation Technologies, Inc. in a lawsuit filed in the Northern District of Illinois. However, in a separate lawsuit on the same patent, Card Activation received a ruling on claim construction which it interpreted as extremely favorable to its interpretation of the patent and its pursuit of infringers of the patent. In June 2007, AÃ ©ropostale was accused of infringing a patent owned by Picture Patents, LLC in a lawsuit filed in the Southern District of New York. In July 2009, AÃ ©ropostale was accused of infringing a patent owned by Furnace Brook, LLC in a lawsuit filed in the Northern District of Illinois Executive Vice President and Chief Merchandising Officer Christopher Finazzo was terminated in November 2006 after an investigation by the Board of Directors revealed that he had concealed and failed to disclose personal and business interests with South Bay Apparel, a major vendor. The SEC issued an investigation on the Finazzo matter in January 2008. Aeropostale, also under the name Aero, is an American clothing retailer that was founded in 1987 and is headquartered in New York. There are a number of reasons Aeropostale started their own business. When you start a business its a good idea to have a business plan that outlines your goals and objectives for the short term and long term. A business plan serves as a blueprint designed to help you grow and develop your business, and ultimately helps shield it from failure. Kara, Postale started the company then Sara(aera) (Karas sister came along) thats how the company got started. So they put there last name and first name together and it turned out to be Sarah postale but they didn’t like that name in 1985 then they changed it to aeropostale because it sounded better and that started in 1987.

Infectious Diseases: Causes, Effects and Treatments

Infectious Diseases: Causes, Effects and Treatments Introduction Infectious diseases or communicable diseases are those caused from pathological microorganisms including bacteria, viruses, fungi, parasites, prions, etc, which can spread from one person to another by direct or indirect means. Infectious diseases can also spread from animals to man or vice-versa (WHO, 2010). Throughout history, microorganisms, the causative organisms for infectious diseases have been playing an active role. Many native populations during the middle Ages have been destroyed by plagues. The Europeans when tried to conquer Australia, Africa and Americas had initially used microorganisms to destroy the native populations. However, the infectious diseases have had a serious effect on the fauna and flora. There were huge causes of morbidity and mortality, but in the 20th century developed nations had lower rates of morbidity and mortality from infectious diseases. The major reasons why there was control over the infectious diseases during the later part of the 20th centur y was due to the development of antibiotics, eradication of small pox through vaccination, improvement in the living conditions and sanitations, etc. However, in the developing nations, infectious diseases are a major cause of death. In the year 1993, about 51 million people died, out of which 16.4 million about 35% were from infectious diseases. In the sub-Saharan African regions about 70 % of the worldwide infectious disease deaths occur. Developed nations account for 10% of the worldwide infectious disease deaths (Wilson, 1995). Today, serious changes are made with the environment of the earth such that certain propulsions and groups are becoming vulnerable to certain infectious diseases. Not only have antibiotics made it easier to fight microorganisms but the abuse of the same has resulted in the microbes developing resistance. Besides, many insect vectors are becoming more and more resistant to various pesticides being used. Today there are several emerging infectious such Ebola, H1N1, H5N1, Lassa fever, etc, due to the changing environmental circumstances. In the year 1993, more than 400000 people from Milwaukee US were affected with the epidemic of cryptosporidiosis. In the Southwest people died from pulmonary disease caused due to Hantavirus infection. Not only are the humans affected with infectious diseases but also various other species of domesticated and wild animals (Wilson, 1995). With History, major changes have undergone with respect to the infectious disease map of the world. In the 20th century, many diseases have spread from tropical to temperate regions and have crossed marine barriers including the Atlantic and the Pacific Ocean. More than 14.2 million people each year die from infectious diseases. On the other hand, heart disease kills about 10 million people each year. The most common infectious disease killer is acute respiratory infectious with 3.7 million deaths each year, followed by HIV/AIDS with 2.8 million deaths, diarrheal group of diseases with 1.7 million deaths, malaria with 1 million deaths and measles with 0.8 million deaths. As sanitation and poor living conditions can increase the risk of infectious diseases, such problems are more common in the lower socioeconomic groups. The WHO has predicted that during the next ten years that infectious disease would reduce by about 3 % due to improvement in the living conditions (Bonita, 2006). In the ICD-9 Listing, codes 1 to 113 are given infectious and parasitic disease codes. It is found that about 83% of all deaths from infectious diseases are from range of symptoms outside the classical ICD mentioned criteria (Norman, 1998). With a number of infectious such as diphtheria, chicken pox, measles, feco-oral infections, cholera, rotavirus infection, etc, seasonal variations play a vital role, in the temperate and the tropical regions of the world. The mechanism by which this is occurring is not understood clearly. Certain reasons may be applicable for the seasonal variations of a disease:- Seasonability has several factors and a lot depends on local factors Depending on the characteristics of the infections epidemics or peak in incidences can occur at different times of the year There may be an interaction of pathogens that may affect the spread of another infection Hence, depending on these criteria vaccination can be used to block the spread of the infection (Nicholas C. Grassly, 2006). Infectious diseases may not just involve one person or a particular community or a population. Often more than one population may be affected across a region or a nation. Besides, infectious diseases can also affect animals including goats (Echinococcus), dogs (rabies), birds (H5N1), etc. Classification The listing of the ICD-9 Codes for Infectious diseases includes:- Intestinal Infectious Diseases 001 to 009 Tuberculosis 010 to 018 Zoonotic Bacterial Infectious 020 to 027 Other bacterial Infectious (such as leprosy, diphtheria, scarlet fever, etc) 030 to 041 HIV 042 to 044 Poliomyelitis, kuru, CJD, etc 045 to 049 Virus with exanthema 050 to 059 Arthropod borne virus infection 060 to 066 Other diseases caused by virus and Chlamydia (such as hepatitis A, B C, rabies, trachoma, warts, etc) 070 to 079 Rickettsia and other arthropod infections (080 to 088) Syphilis and other venereal diseases (gonorrhea, urethritis, etc) 090 to 099 Other Spirochete infections such as yaws, pinta, etc 100 to 104 Mycoses or fungal infectious 110 to 118 Helmenthic or worm infestation 120 to 129 Other infections 130 to 136 Late effects of infections 137 to 139 (ICD-9 codes) Transmission Infectious diseases are transmitted by two means, namely the direct and indirect means. Direct means includes contact with the infected person who comes in contact with the normal person. Through contact, infections can spread by three means, the first two include horizontal means and the third include vertical transmission. Infectious diseases usually spread by direct transfer of the infected fluids or secretions from one individual to another. There may be several means of person to person transmission including sharing infected needles, sexual contact, kissing, blood transfusion, sneezing, coughing, mucosa to mucosa, etc. Direct contact would also include contact with infected animals or handling contaminated animal wastes. The vertical transmission is by means of the infected mother to the baby. Infections again can be transmitted by different means at different periods. When the unborn baby is in the uterus, it can get infected from the mother. Certain infections can be transmit ted across the placenta and include bacteria (such as syphilis, listeriosis), viruses (such as CM Virus, AIDS, German measles), and protozoans (such as toxoplasmosis) (Lee Goldman, 2007). The effect on the fetus may range from fetal infections, lesions, mental retardation, physical growth retardation, multi-organ defects, birth defects, aborted, etc (Dorak, 2009). On the other hand, infection can spread to the baby during passage of the baby through the infected birth canal. Lastly, infection can spread through contaminated breast milk of the mother during nursing (Lee Goldman, 2007). Exposure to the infectious agents can result in various outcomes including no infection, clinical infection, sub-clinical infection or carrier status. Clinical infection can result death, carrier status and further immunity or no immunity against the disease. Sub-clinical infection can result in carrier status, immunity or no immunity against the disease (Dorak, 2009). Infectious diseases can also spread through indirect methods which include contaminated objects, personal items, food borne, waterborne, vector borne, air-borne, ting-borne and surfaces. For example, common cold can spread by using contaminated towels. Various bacterial, viral and parasitic infections can spread through vectors or carriers such as mosquitoes, fleas, lice, ticks, etc. Infectious diseases can also be transmitted from one individual to another through contaminated food or water or the oro-fecal route. Consuming uncooked, undercooked or raw foods, unsuitable drinking water, etc, can cause infectious. For example, in Latin America, there is evidence through PCR diagnostic tests that H. pylori cause gastric problems (Lee Goldman, 2007). Certain individuals may be at a higher risk of getting infected which includes those with autoimmune disorders, those who have undergone an organ transplant and are taking immunosuppressant, those consuming corticosteroids and those infected with HIV/AIDS. The other risk factors that play a role in the development of the infectious diseases may include age, race, sex, socioeconomic status, geo-location, medication use, illegal drug use, history of travel, etc (Sherwood, 2004). The mode of causation of an infectious disease is by an interaction of internal factors and environmental factors. An infection may arise as a result of a triad of factors affecting the system including the host, agent and the environment. The host factors include age, sex, gene-type, mental makeup, nutritional makeup, immune status, and health makeup. The environmental factors include air, water, sanitation, psychosocial status, geography, housing, food, healthcare delivery system, etc. The agent factors include pathogenicity of the organism (ability to cause disease), infectivity (ability to cause infection), virulence (ability to cause death), immunogenicity, survival and antigenic capabilities (Dorak, 2009). The entire natural cycle of the infection would ensure that the infectious agent is at the business end. The infectious agent would enter the host or reservoir and then exit from the body, carried by a mode of transmission and enter another persons body. It would result in infection in a susceptible host. Koch bought out certain postulates for infections. In each case, the organism is present. The organism can be isolated or grown in each culture. Once each individual is exposed to the agent, the disease as such can be reproduced. From each of the infected individuals, the pathogen can be isolated. Symptoms An individual suffering from an infectious disease may present with no symptoms, symptoms which are not definitive, mild symptoms, or serious symptoms with complications. The period between the exposure of the individual to the infectious organism and the appearance of the first symptom may vary from a few days (in the case of chicken pox, malaria, etc), months to a few years (in the case of HIV). Infectious disease can produce a range of symptoms including:- Fever Chills and rigors Bleeding of the gums and periodontal diseases Epistaxis Sore throat Anorexia Tiredness Body pain Dyspnea and breathing problems Headache Fever with seizures Swelling or a rash Malaise Enlargement of the regional lymph nodes along with tenderness Diarrhea and dysentery Bloody stools Yellowness of the skin and the tongue Paleness Skin lesions or skin rash Blood shot eyes (in the case of conjunctivitis) Burning sensation whilst passing urine Abscess or a draining sinus Pain, swelling from the affected site along with a rise in the temperature Gastritis Spread of the bacteria, along with the toxin in the blood Diagnosis The diagnosis of Infectious disease is made based on the history, physical examination, signs, symptoms, analysis of the tissue samples, microscopy, culture, blood tests, urine tests, molecular diagnosis and other methods. The history includes details of the personal history, history of travel, family history, social history, occupational history and epidemiology (Paul G. Engelkirk, 2007). Body samples of urine, CSF, nasal secretions, nasal swab, stools, etc are collected to study them microscopically. In certain circumstances water, soil, inanimate objects and food samples are also analyzed. In certain circumstances the samples are collected at a particular period of time. In malaria, the samples are collected when the fever is high and in the case of typhoid the blood samples are collected when the fever begins to rise. It is important to prevent contamination of the sample during testing and avoid any destruction of the causative organisms. It is important to transport the samples appropriately and test them immediately as many anaerobic species may not be able to survive in the oxygen-rich environment. Besides, it is also important to prevent drying of the samples. All samples should be given appropriate care during laboratory testing as they are hazardous and can infect the testing personnel (Barbara A. Bannister, 2000). There are different microscopes that can be used for studying the samples including light microscope, phase-contrast microscope, dark-field microscope, electron microscope, etc. Various staining procedures may be required to study the samples including gram staining, Giemsa staining, Ziehl-Nielsen staining, Indian Ink staining, etc. Helminthes, urine bacteria and fecal protozoan are best viewed through direct microscopy of unstained samples. Gram staining helps to identify organisms in pus, CSF, ascitis, pleural fluids, etc. Ziehl-Nielsen staining is used to study that will not stain through ordinary procedures. Romanowsky staining is used to stain blood cells, whereas Giemsa staining is used to identify the parasites present in blood. Immunofluorescence is a method of identifying the organisms through reactions with antibodies tagged with fluorescence dyes. There are two methods of immunofluorescence including direct and indirect methods (Barbara A. Bannister, 2000). Culturing involves growing the microorganisms present in the sample in the laboratory on an appropriate media and recognizing the same using physical, biochemical and morphological means. Different media may be used including enriched media, selective media and indicative media. Another process of distinguishing between the various strains of an organism is typing. These include biotyping, auxotyping, serotyping, phagetyping, PCR typing, etc (Barbara A. Bannister, 2000). Blood tests called as serological tests are done to determine the antigen-antibody reaction that occur. Some of the common tests that are done in the laboratory include agglutination, fluorescent antibody tests, radioimmunoassay and ELISA. Molecular methods of diagnosis are used to determine specific DNA fragments that would be a signature of certain species of pathogens. Some of the common molecular diagnostic techniques include PCR and amplification techniques (Barbara A. Bannister, 2000). Treatment One of the earliest ways of managing an infectious disease was in malaria when certain local communities used cinchona to treat the disease. From the cinchona bark, quinine was extracted and is used even today to manage malaria. Today, antimicrobial agents are being used to treat infectious disease. These microbial agents attack the various metabolic pathways that are present in the microbial metabolism. For example certain compounds are similar to PABA, and prevent PABA from undergoing transformation into dihydropteroic acid, which is essential for folate metabolism. Once there is shortage of folic acid in the body, the DNA of the bacteria undergoes degradation. Further other antimicrobial agents which target other portions of the metabolism can also be used for more effective treatment of infectious diseases. These include trimethoprin and sulphamethoxazole. The other ways by which antimicrobial agents act include causes the destruction of the bacterial cell wall, inhibition of the protein synthesis in bacteria, and damaging the DNA structure. For certain antimicrobial agents to act, the bacteria should be sensitive to the drug. Besides, the manner in which the drug is administered and the spectrum of action of the drug also plays a vital role in treating infections. Antimicrobial sensitivity tests are conducted to determine which particular agents the bacteria would be sensitive and resistant to and accordingly select a potent agent to treat the infection (Barbara A. Bannister, 2000). To ensure that the treatment with antibiotics is working properly certain monitoring strategies may be required including:- Appropriate levels of antibiotics are present in the serum The levels of antibiotics do not reach a level such that it would cause toxic effects Patient compliance and adherence Appropriate means of administration Pharmacokinetics of new drugs Monitoring all the adverse effects (dose-dependent or idiosyncratic) Some of the common groups of antimicrobial agents that are used to treat infections include:- Penicillin Penicillinase resistant penicillin Ampicillin-like agents Beta-lactamase inhibitors Cephalosporin Aminoglycosides Chloramphenicols Quinolones Antifungal Agents Antiviral agents Antimalarial agents Antitubercular drugs Antiprotozoan agents Prevention Infectious diseases are transmitted from one individual to another through several routes including direct contact, inhalation of airborne infections, consuming contaminated food or water, through vectors such as mosquitoes, ticks, etc, sexual contact, using contaminated personal items and through the mother-fetal route. Hence, prevention can be advocated by obstructing the means of transmission of the infection. One of the most important methods of prevention is by proper and frequent hygiene by handwashing and using a disinfecting soap. Immunization also plays a vital role in preventing infections by administering vaccines to the general populations. Vaccines are currently available for a number of bacterial and viral infections including meningococcal infections, hepatitis B, hepatitis A, polio, diphtheria, typhoid, tetanus, haemophilus influenza, chicken pox, rotavirus, human papilloma virus, H1N1, measles, mumps, rubella, etc. Passive immunization can be administered by the admi nistration of immunoglobulin. Zoonotic infections can be prevented by immunizing the pets, providing a clean and safe environment for the animals, washing hands before contacting animals, takes measures after animal bites, etc. At the workplace, transmission of infections are a risk because of the conditions and also because people are in close contact with each other and also with hazards. Needles, syringes and other biohazards need to be disposed off properly. Blood during donation and infusion should be appropriately screened for various blood-borne infections such as HIV, Hepatitis B, hepatitis C, syphilis, etc. Rubber gloves should be worn by the healthcare professional and for every new patient, a new set of sterile drugs should be selected. Hospital wastes should be disposed off properly to prevent hazardous wastes from further causing havoc (Andi L. Shane, 2008). Safe sex and sexual hygiene is also essential to prevent risk of transmission of STDs such as HIV, hepatitis B, etc. If there is the chance of the partner practicing unsafe sex, then a condom and other barriers help reduce the risk of transmission. Special precautions also need to be taken during travel. Areas infected with infectious diseases should be best not visited. For some people, vaccination may be required along with consumption of prophylactic antimicrobial agents (Andi L. Shane, 2008). Infectious Diseases in Saudi Arabia As in the rest of the world, in Saudi Arabia also, the morbidity and mortality from infectious diseases are high. An infection would have its course and severity varied depending on the virulence of the agent and the resistance of the host. Besides, a number of environmental factors also need to be considered. Two of the most common infections and serious health problems in the Western populations have been community-acquired pneumonia and fever of unknown origin (PUO). In the US, each year more than 1.3 million people get hospitalized from infectious diseases. The WHO has attributed Tuberculosis the most common cause of death in the world adult population. Certain factors may increase the risk for TB including HIV status, lower socioeconomic background, poor sanitation, etc. The other common infectious diseases throughout the world were hepatitis B, malaria and meningitis. Alghamdi found that the prior knowledge of prevalence and pattern of infectious diseases in the Western Saudi A rabian population was rather unknown and hence conducted this study to determine the most common infection in the hospitalized and determine their mean time of stay. More than 495 patients that were hospitalized between Jan 2000 to December 2004 at the King Abdulaziz University Hospital (KAUH) was studied. All data was collected from the patients medical records. About 8.8 % of the population who were admitted to the hospital or 1 in 11 were admitted for infectious diseases, and slightly more than 50% were males and 54% were native Saudis. Individuals between 26 to 45 years were commonly affected with infectious diseases, followed by the 13-25 year old group. The senior citizen population was least often affected with infectious disease. The most common infectious disease was pneumonia, followed by fever of unknown origin, TB, and viral hepatitis. In women, pneumonia was more common than men, whereas TB and meningitis were more common in men. The other common infectious in the population included bronchopneumonia, malaria and urinary tract infections (Aisha A. Alghamdi, 2009). The incidence of meningococcal meningitis is common in Hajj pilgrims and in the year 2000, several cases were reported in the Hajj pilgrims. The two common serogroups were serogroups A (24%) and W-135 (37%). The epidemiologists found that the Hajj Pilgrim 2000 Meningococcal attack was in fact two concurrent outbreaks. The W-135 serogroup is endemic in Saudi Arabia. The fatalities were high amongst the pilgrims and hence since the year 1987, mandatory vaccination was being introduced. The vaccine used in fact is quadrivalent in nature (Jairam R. Lingappa, 2003). The Tuberculosis statistics in Saudi Arabia were also alarming. In a study conducted by Sahal A. M. Al-Hajoj, 2006, it was found from about 1500 cases of Tuberculosis infection, that male-female ratio was 1.27 and 47% of the population being adults between the age groups of 21-40 years. The single drug resistant cases were about 19.7 % and the multi-drug resistant cases were about 47% (Sahal A. M. Al-Hajoj, 2006). Sahal A. M. Al-Hajoj (2009) conducted another study to find if the mortality and morbidity from tuberculosis could be decreased in Saudi Arabia. There was a rise in the number of cases of TB between 1990 and 2004 by about 6.2%. In Western Saudi Arabia, there is a huge influx of individuals from developing countries who may already be infected with Tuberculosis. The rise in tuberculosis cases may not only be due a rise in infection rate, but also due to better diagnosis techniques. Better TB programs and effective diagnostic laboratories are the need of the hour in controlling cases of tuberculosis in Saudi Arabia. There should also be greater uniformity across the country in standardization. In the year 2000, there was an epidemic of Rift Valley Fever in Saudi Arabia which had spread from the neighboring North African Region. About 886 patients were included in the study by Tariq A. Madan. The age group affected was the 40 to 50 year, and the male to female ratio was 4:1. The common symptoms recorded included fever, nausea, vomiting, abdominal pain, jaundice, diarrhea, neurological complications, bleeding, visual loss, liver function test abnormalities, leucopenia, renal failure, anemia, etc. There were about 14% mortalities from the disease and were often associated with bleeding, neurological symptoms and jaundice. People with leucopenia had a lower mortality than those who had a rise in the leukocyte count (Tariq A. Madan, 2000). In the year 2007, the first outbreak of H5N1 occurred in Saudi Arabia and affected 19 poultry farms. Several diagnostic tests were conducted to confirm the infection including Rapid antigen-capture test and real-time RT-PCR. Once the infection was identified in a particular town in Saudi Arabia, the government immediately made a decision destroy the H5N1 affected fleet and the non-affected birds in a radius of 5 kilometers and ensure quarantine measures were followed in the region so that the infection could be prevented from spreading to other regions. Besides, other measures were being adopted including closing bird markets, greater surveillance, quarantine, etc. Within a period of three months from the first detected cases, the epidemic was totally under control. Further within a period of three months (April 2008), Saudi Arabia was declared as H5N1-free (Huaguang Lu, 2009). In a study conducted by Abdulrahman A. Alrajhi (2004), the mode of transmission of HIV-1 was being studied. It was found that 46% were heterosexual transmission, 26% due to infected blood transfusion, 12% vertical transmission, 5% from homosexual activities and 2% due to use of contaminated syringes during IV drug usage. Most of the heterosexual men got infected from commercial sex workers, and about 65 women got infected from their husbands. In Saudi, the most rampant form of transmission of HIV-1 is heterosexual mode. The mean age of diagnosis of HIV in the 410 individuals who took part in the study was 27.8 years. The adult infection rate is about 0.01%. Women tend to get the infection from their spouses. The rate of infection was relative lower in homosexual men and IV Drug users (Abdulrahman A. Alrajhi, 2004). Thus it can be seen that infectious diseases are a serious problems. Some of the infections that are common in Saudi Arabia include pneumonia, Fever of unknown origin, tuberculosis, meningitis, HIV, acute viral hepatitis, chronic viral hepatitis, malaria, etc. Besides, outbreaks of several emerging infections are becoming commoner in Saudi. These include the Rift Valley Fever of 2000, H5N1 outbreak of 2007, dengue fever, viral hemorrhagic fever, multi-drug resistant tuberculosis, etc. Many of the zoonotic infectious are getting transmitted to man by vectors such as ticks and mosquitoes (Tariq A. Madani, 2004). The mechanism of development and the transmission of such infections need to be studied.