buy custom HIV essay

buy custom HIV essay HIV stands for Human Immunodeficiency virus as per the definition given by a medical center called UCSF. The virus is acquired through unprotected sexual intercourse with an infected partner, from an infected mother to an unborn child, blood transfusion and during breastfeeding. The virus weakens the immune system of a person by destroying the CD4+T cells making a person the infected persons immune system weak. As the HIV viruses increase, the number of CD4+T cells in the body reduces from the normal 800-1200 cells per cubic millimeter (mm3) to as low as 50 CDA+T cells per cubic millimeter(mm3). The infections develop in different stages. One of the foundations dealing with HIV and AIDS called San Francisco has given the stages as follows. The first stage is the window stage or the primary stage which occur a few weeks after infection .The symptoms in this stage include fevers, night sweats and rashes on the skin. However, after a few weeks the persons body returns to its healthy state. If a person takes an HIV/AIDS test at this time the result might be faulty because the virus may have not established itself fully in the blood stream. It should be known however that such a person can still infect other people with the HIV virus .Later the symptoms may recur but the time may differ depending on the strength of the immune system of a person. he second stage which is the seroconversion stage occurs after the first six months after but differs with the capability of the immune system to fight diseases. At this stage the body starts reacting to the virus by producing antibodies .If one gets tested at this stage the results will not be correct. The third stage is the asymptomatic stage; the person still looks healthy but can infect other people if they have unprotected sexual intercourse. The virus continues to destroy the CD4+T cells weakening the immune system. The next stage is the symptomatic stage. At this stage of the infection, a person develops pneumonia, sores on the throat, mouth, anus and genitals, reddish, purplish brownish and pinkish batches on the skin, memory loss, depression, slight weight loss in women, tiredness, hair loss , recurring fever , extreme tiredness and profuse night sweats, diarrhea . This does not mean that each person infected develops the symptoms immediately; some may take up to twelve years to show these signs while some may develop earlier. As the HIV virus multiplies it continues weakening the body immune system of a person giving way to opportunistic diseases. The person becomes immune deficient or has now developed AIDS, which is a short form of Acquired Immunodeficiency Syndrome. The body can no longer fight opportunistic diseases such as; bacteriial diseases like tuberculosis, pneumonia and blood poisoning, the body cannot also fight diseases caused by protozoans like toxoplasmosis, fungal diseases like candidiasis, and penicilliosis and viral diseases like herpes simplex and herpes zoster which are more common in women than in men. These diseases develop at different times e, g malaria and pneumonia tuberculosis and herpes zoster occur in the early stages of the infection where else toxoplasmosis and PCP occur affecting major body organs. People with HIV/AIDS are prone to cancers like cervical cancer and Kaposis sarcoma and treatment using therapy to treat cancer is difficult as the ability of the lymphocyte to fight germs has been weakened by the virus. Children are also in high risk of getting infected with the opportunistic diseases such as those affecting older people, but are more affected by bacterial infections like ear infections, tonsillitis, stunted growth, and pink eyes. This is because the defense is lower compared to those of adults (HIV AND AIDS: Mayo clinic). When the CD4+T cells of a person are less than 200 per cubic millimeter then the person has full blown HIV virus and should seek medical help so that he/she can be examined by a doctor which include pregnancy tests for women. The person is then given antiretroviral medication and antiretroviral (ARV) therapy. Buy custom HIV essay

What Is the Specific Heat of Water How Is It Special

What Is the Specific Heat of Water How Is It Special SAT / ACT Prep Online Guides and Tips If you’ve ever walked along a beach on a sunny day and dipped your toes in the water to cool them off after the hot sand, you’ve taken advantage of the specific heat of water. Despite how it may sound, specific heat doesn’t refer to the exact temperature of something. It’s a larger scientific concept that has to do with the energy it takes to heat a substance up. As you might have noticed from the example, not all substances warm up at the same rate- hence the different temperatures of the sand and water. Water’s specific heat is one of its most interesting characteristics. In this article, we’ll be covering what specific heat is, what equation you use to find specific heat, and why water’s specific heat is so high. The stove, pot, water, and steam all have different specific heats. What Is Specific Heat? Specific heat is a measure of heat capacity, or how much heat a material can store when changing temperature. A high heat capacity means that a substance can absorb a lot of heat before registering a change in temperature- think about how long it takes for a pot to get warm to the touch on the stove versus how long it takes the water inside to get warm. That means that water has a higher heat capacity- it can store more heat before changing in temperature. Specific heat refers to the exact amount of heat needed to make one unit of mass of a substance one degree warmer. Returning to our example, specific heat would identify exactly how much heat is required to make one unit of water, such as one cup, one degree warmer. Because heat is really a measure of energy transfer, it’s more accurate to say that specific heat is actually a statement of how much energy a substance can absorb before a one-degree change in temperature. Specific heat is typically measured in Joules and kilojoules per one gram of mass, with Celsius as a measure of temperature. Kilograms and Fahrenheit may be used, but it’s rarer. A substance’s specific heat can be affected by temperature and pressure, so specific heat is typically determined at constant temperature and pressure, typically 25 degrees Celsius. What Is the Equation for Specific Heat? The equation to calculate specific heat is: $$Q = s Ãâ€" m Ãâ€" ΔT$$ $Q$ represents the amount of heat, $s$ the specific heat (${\Joules}/{\gram *  °\Celsius}$), m the mass of the substance in grams, and $ΔT$ the observed change in temperature. Different kinds of water, such as seawater, may have different specific heat. What Is the Specific Heat of Water? Some substances heat up quickly, while other substances heat up slowly. Water is one of the latter- it has a high specific heat capacity because it requires more energy to raise the temperature. Water has a specific heat capacity of 4182 J/kg °C. Because water is such an important and common substance, we even have a special way to identify the amount of energy it takes to raise one gram of water by one degree Celsius- a Calorie. This is different from the kind of calorie we talk about in food. That kind of calorie is equivalent to 1,000 Calories, which is why food-related calories are also sometimes referred to as kilocalories, or kcals. The specific heat of water is quite a bit higher than many other common substances. For example, the specific heat of iron is 449 J/kg °C, sand is 830 J/kg °C, and oak timber is 2400 J/kg °C. That’s because water, comprised of two hydrogen atoms and one oxygen atom, is electronegative. An electronegative atom is more likely to draw electrons to itself, because one side of the atom will have a partially positive charge and the other will have a partially negative charge. The opposite-charged sides are naturally drawn to one another, forming a weaker hydrogen bond. That’s why water is able to flow past itself, but also bond together- it’s constantly forming and breaking these bonds. These bonds are also why liquid water has a high specific heat. Any energy put toward heating water is split between breaking the bonds and heating the water. Because of this, it takes more energy to heat water than it does other substances. For example, if you’re at the beach on a sunny day, you’ll notice that the sand is often quite hot to walk on, but the water always feels cool, even in the shallows. That’s because sand has a lower specific heat capacity- it takes less energy to raise the temperature by one degree. Because water has a high heat capacity, it requires more energy to raise the temperature by one degree. The sun puts out a more or less constant rate of energy, which heats up sand more quickly and water more slowly. Sand has a much lower specific heat than water- that's why it gets hot so fast! Specific Heat Table If you’re not already familiar with Joules and Calories, these numbers might seem a little abstract. Take a look at this table to familiarize yourself with some common specific heats according to both Joules and Calories, and compare those to what you know of how these substances heat up! Material Specific Heat in J/kg °C Specific Heat in Cal/gram °C Gold 129 0.031 Air 1005 0.24 Leather 1500 0.36 Olive oil 1790 0.43 Paper 1336 0.32 Table Salt 880 0.21 Quartz Sand 830 0.19 Steel 490 0.12 Liquid Water 4182 1.00 Wood 1300 - 2400 0.41 What’s Next? If the specific heat of water has you all fired up about chemistry, AP chemistry may be for you! Check out this AP chemistry syllabus to learn more about what topics will be covered. Or maybe you're already in AP chemistry and you're looking for some tips and tricks for how to ace your exam. Check out this guide to the AP chemistry exam for everything you need to know! If you're not quite ready for the exam but you need a little extra boost in your AP chemistry course, this AP Chemistry study guide may be just what you're looking for.