Narcosis ciliates Essay Example | Topics and Well Written Essays - 1500 words

Narcosis ciliates - Essay Example This movement propels the cell perpendicular to the orientation of the cilia. In contrast, the longer flagellum, usually one or two, moves in an undulating manner, moving successive waves from the base to the tip in the process. As such, it propels the cell to move parallel to the flagellum’s orientation. On the other hand, microvilli are non-motile appendage with no internal structure supporting it (Reece, et al., 2011). The loss of activity of cilia, resulting to loss of cellular motility, is termed ciliate narcosis. This can be induced by different living conditions and substances to which it is exposed to, such as low temperature (Jackson, Goggin and Lucas, 2012), calcium (Nakanaka, Tanaka and Oosawa, 1984), magnesium and protein (Adshead, et al., 1975) concentrations, as well as the presence of certain substances, such as theophylline, bromhexine, ambroxol, terpin hydrate, mercaptoethanesulfonat-sodium, amrinon, salbutamol, tetracosactid-hexaacetate, histamine, phenol and nitric oxide (Graf, Graf and Wenz, 1999). In addition, a study using tracheal cells in vitro, showed that ciliary beat frequency was increased at low ethanol concentrations (0. 01 to 0. 1%), unchanged at (0. 5 to 1%), and decreased above 2% (Maurer and Liebman, 1988). Moreover, even if it does not penetrate the cellular membrane, the presence of glycerol in the culture can make cellular surroundings viscous, making it more difficult for cilia to move (Negus, 1949). Alcohols are amphiphatic molecules primarily composed of alkane (CH3) and hydroxyl (OH) moieties, such that the simplest alcohol is methane (CH3OH). When the hydrocarbon portion becomes longer, as in the case of ethanol (2 Cs), propranol (3 Cs) and butanol (4 Cs), the alcohol becomes effectively more hydrophobic. A compound similar to alcohols, propranolol in particular, is glycerol, which has hydroxyl group attached to each of the three carbon atoms (Masterton and Hurley, 2008). One of the well-studied organisms known t o extensively use cilia for movement is the free-living Tetrahymena pyriformis, which belongs to the order Holotrichia, literally meaning cilia all over its membrane. The microorganism is a common fixture in human toxicity studies, because of its cilia’s similarity in terms of morphology and function to that of human epithelial cells (Graf, Graf and Wenz, 1999). Its cell membrane has the characteristic sandwich-like phospholipid bilayer, with the hydrophilic head facing the cytoplasm or the external surroundings, and the hydrophobic chain filling the middle. Given this structure, hydrophilic molecules can more easily pass the membrane, as compared to hydrophobic ones. However, the presence of transport mechanisms allows hydrophobic molecules to enter the cell (Reece, et al., 2011). In cellular permeability studies, an observable cellular change effected by previously identified substance must be utilized in order to clearly determine when and in what conditions the substance penetrated the cell membrane. In this case, the cellular change used was ciliate necrosis and the substance that causes it would be alcohol. This experiment was conducted in order to 1) observe narcosis of T. pyriformis ciliates by alcohol, and 2) discuss the results of ciliate narcosis in terms of membrane permeability. METHOD After preparing propranol and glycerol serial dilutions (propranol: 1.8 M, 1. 5M, 0. 4M, 0. 2M , 0M; glycerol: 2. 8M, 2M, 1. 7M, 1M, 0M) using distilled

Discuss Why Risk Management is not a Good Objective for the Criminal Essay

Discuss Why Risk Management is not a Good Objective for the Criminal Justice Process - Essay Example Risk in the criminal justice system is widely associated with young offenders. There are those who have a lot of risk factors such as truancy, the low achievers and those from a single-parent family. The children who have less parental supervision are also vulnerable to anti-social behavior that may lead to criminal activities. In fact, crime statistics chow that the youth are more susceptible to involvement in criminal activities than adults. This correlation between crime rate and age does not only apply to the offenders, but also to the victims of those criminal activities (Kemshall, 2003). The process of assessing and managing risk has, therefore, become a prime issue for discussion in every criminal justice system. In the assessment of risk in a criminal offence, the character of the individual is evaluated to determine whether there is the possibility for them to commit other acts of violence. Because risk management requires the consideration of both situational and psychologi cal factors, it requires constant modification and review so that public safety is ensured. The management of dangerous offenders in the recent past has brought about a lot of concern the world over. This concern has been mostly reflected in the media and other social forums (Armstrong, 2004). One of the areas that have sparked too much concern from the public is area of sexual offences. This type of crime has led to the outcry in the media where there have been campaigns against sexual offences in the society. In these campaigns, the media seeks to identify the sexual offenders, publish their names and shame them so that they do not repeat the same habit again. The campaigns also encourage the use of vigilante justice as well as the formation of a punitive attitude in the public towards sexual offenders. In the long run, such a campaign would lead to the isolation and stigmatization of sexual offender who would be expected to seek rehabilitative programs and reforms (Kemshall, 2003 ). A lot of articles in the media today contain news about sexual offences. Sexual crime has been dominating the media headlines probably because of the prevalence rate of the crime. This type of crime has, therefore, provoked public outcry because of the publicity it receives. This publicity generated by the media has, however, caused a number of negative effects on the perspective of sexual offences and offenders. It has affected the public’s opinion on sexual crimes as well as their perception on the necessary measures that should be taken in cases of sexual crime (Kemshall, 2000). The general perception created is that of a looming danger to all women and children. They are continually reported as the target group for sexual monsters. When the media concentrates on only one category of sexual offenders, they create the impression that pedophilia, for example, is increasingly rampant. Media may also influence a punitive attitude in the public in relation to sexual criminal s. Increased political and media outcry on this subject provokes the public to assume activities like vigilante policing. The attitude of the public towards sexual offenders as well as heightened hysteria is also provoked. It is these attitudes formed towards sexual offenders that necessitate the management of risk. The public should, therefore, be protected from sexual offenders at all costs (Phoenix, 2010). The concept of risk management in the criminal justice system has been