Write a 500 words essay on the following topic: Some people feel that it is always wrong to keep animals in captivity, for instance in zoos. Other people say that there are benefits for the animals and the humans. Discuss both sides and give your personal view.
Zoos and safari parks continue to be current controversial subjects even though zoos have evolved into animal parks that attempt to provide animals with the highest quality of care. There is much controversy and both sides can bring strong arguments at the table. I will present the arguments for both sides as follows: Firstly, the strongest pro argument for these types of enclosures is that endangered animals residing in safari parks are part of poaching protection and breeding programmes. This is of uttermost importance as certain animals are so heavily endangered that they simply can no longer only be part of breeding programmes in their natural habitat. Secondly, animals that are difficult to spot in the wild are used for behavioural studies in safari parks. This kind of information could subsequently be used to apply for conservation programmes for the given animals or other animals up or down their food chain. Additionally, animals living in zoos and safari parks that would otherwise be inaccessible for life study can be used to teach life, natural and veterinary science students. Zoo-based animal programmes are beneficial because they protect endangered species and thus preserve the ecosystem for the future benefit of all life forms. In contrast to the arguments presented above, some say that animals should not be kept in enclosed spaces that sometimes can be less than 5% of the space they normally use in their natural habitat. Furthermore, it has been scientifically proven that animals in zoos can get depressed and exhibit sadness-like symptoms. However, it is important to note this is applicable mostly to animals that have not been born in captivity. In addition to the first counter argument, animals in zoos don’t need to hunt or go gathering for their food as animals in the wild would do and thus they do not live the life they are intended to. In conclusion, I believe that animals in safari parks should only be kept captive if they are threatened in the natural habitat and all past conservation projects have previously been unsuccessful. Animals in safari parks and zoos can live a happy and long life as long as the facilities are clean and away from the noise in the big cities and animals receive the veterinarian care and attention animals need.
Describe the cardiovascular system, compare the different types of vessels from an anatomical and physiological point of view and give an example of a vascular disease explaining its pathophysiology.
The cardiovascular system has three main roles: it transports oxygen, nutrients and hormones and other proteins to all cells in the body whilst collecting cell waste, it regulates body pH, temperature and the amount of water inside a cell and it transports white-blood cells and clotting cells that ensure protection against pathogens or prevention of exsanguination following injury. The cardiovascular system is comprised of the heart, a pump-like muscle, and various blood and lymphatic vessels that act as pipes, circulating blood and lymph throughout the body. The heart rhythmically contracts to send blood full of oxygen to the rest of the body and carbon dioxide-rich blood back to the lungs. The largest vessel in the body, the aorta, is connected to the left atrium (the upper chamber of the heart) and it is filled periodically with oxygen-rich blood. The aorta forms branches and splits into various smaller arteries and arterioles which are also split into smaller vessels and continue to downgrade in size until they become capillaries. These are the smaller blood vessels in the body. They facilitate nutrient and oxygen absorption by cells. From the capillaries, the blood circulates towards venules and veins, eventually collecting into the largest veins in the body the inferior and superior vena cava vessels that return the blood back to the heart. Normal functioning of the cardiovascular system and deviations from the normal blood flow can result in long-term life impacting effects. For example, interruption of the blood flow that irrigates the brain results in an environment that is low in glucose and oxygen leading to cell death, this is known as a stroke. Blood flow cessation is caused by the build-up of atherosclerotic plaque, a fatty core composed of lipids and macrophages (cells that normally clear up bacteria and viruses, but that sometimes get lost in the vascular system and attack the body in the absence of infection with pathogens). In addition, weakening of the blood vessel wall due to the expansion of the atherosclerotic plaque through the vessel can also result in improper irrigation of the brain cells with the blood. In conclusion, the cardiovascular system plays a major role in ensuring the delivery of molecules and substances that are of uttermost importance for survival.
In hypothesis testing what is the difference between the null hypothesis and the alternative hypothesis?
Hypothesis testing is performed to help examine data sets and choose between two hypotheses. On the one hand, the variation observed in the data is due to sampling error, this is a null hypothesis; or, on the other hand, the variation observed is due to the factor investigated, this would be the alternative hypothesis. The null hypothesis states that there is no statistical difference between the data (two or more data groups) compared. As hypotheses come in pairs - null and alternative, the alternative hypothesis, as expected, states that there is a statistically significant variation between the data compared. For example, one could formulate the following set of hypotheses: Null - There is no mean/median difference in the tumor size of patients that received placebo compared to the patient group that received treatment. Alternative - There is a mean/median difference in the tumor size of patients that received placebo compared to the patient group that received treatment.