GetWrite Coursework Example | Topics and Well Written Essays - 250 words

GetWrite - Coursework Example This is the location where crime and illegal immigration are most likely to intertwine. Accordingly, this is where the study would ideally be centered. In any experiment, it is desirable to partake in some form of random (probability) sampling. In this case, every member of the target population would have an equal chance at being a participant in the study. In order for this study to be truly random, then all persons living along a dangerous border crossing area would have the chance to be in the experiment. Unfortunately, this is not possible due to many restraints (time, money, etc.) and so we are forced to settle for a form of non-probability sampling. Specifically, we will be using convenience sampling, which means we will study the people who are easiest to study along the border area. This is necessary due to the potential hostility in the area, as well as travel restraints. This is certainly a limitation of the experiment, as it makes it much harder to apply the results to the entirety of the target population. It should be noted that the expected link between illegal immigration and crime might not be a simple direct relationship. One recent study identifies the overbearing crackdown on illegal immigration as a cause of more crime by making criminals stay in the areas longer (Hammond,

Control of microbial growth Research Paper Example | Topics and Well Written Essays - 1000 words

Control of microbial growth - Research Paper Example Controlling microbial growth is very critical in preventing food spoilage.There are different techniques used in controlling microbial growth. These will be addressed in this essay. Different technologies used to control microbial growth employ varying mechanisms to cause the death of mechanism. Of critical importance to note is that the rate at which microbes die is usually constant such that logarithmic plots from depicting microbial death are usually straight and descending. Some of the microbial growth control techniques usually cause the cell membrane of microbes to exhibit a new level of permeability, leading to an uncontrolled leakage of cell content. This leakage ultimately leads to cell death. Other techniques usually damage cell proteins and nucleic acids, a mechanism that affects both RNA and DNA. This damage also leads to cell death. There are other mechanisms that serve to limit cell growth as scientists have described over time (Kratz, 2005). Physical Methods There are physical ways that have proved efficient in controlling cell growth. One of these is heat. There are certain terms related to the use of heat in controlling microbial growth that scientists have coined over time. ... A more effective strategy is often the use of steam under pressure as it becomes easier to obtain temperatures higher than the boiling point. For example, typical sterilization temperatures in an autoclave are usually 121 degree Celsius and a pressure of 15 psi with sterilization lasting 15 minutes. An additional technique used is pasteurization as described from the concept developed by Louis Pasteur. This technique employs a certain range of temperatures that ensure that microbes die but the flavor and taste of the product as well as the nutrients remain. It is important to note that this technique does not kill all the microbes, but targets those that lead to food spoilage (Srivastava, &Srivastava, 2003). Pasteurization often uses the principle of high temperatures for a short period. Dry heat may also prove useful in sterilization as in the case in incineration and sterilization in an oven. In addition to heat, scientists have also described the use of filtration membranes that h ave the capacity of separating certain microbes. This technique is applicable for liquids that prove to have high heat sensitivity. A typical example is the use of special membranes to filter air used in theatres. The use of low temperatures in the refrigerator usually at 0-7 degree Celsius ensures that microbes do not grow. However, some microbes need freezing temperatures to become inactive. In other cases, high pressure becomes useful in treating juices to prevent spoilage although endospores prove resistant to that pressure. Of importance in such cases is ensuring that flavor and nutrients do not fade in the process.Desiccation is also a way of limiting microbial growth as it deprives