Fundimental of microboilogy Term Paper Example | Topics and Well Written Essays - 1500 words

Fundimental of microboilogy - Term Paper Example The catalase test is a biochemical test that can be used to identify between Staphylococcus spp. and Streptococcus spp. The enzyme catalase contains a heme group and detoxifies hydrogen peroxide. The basic theory used in their identification is that one is catalase positive (Staphylococcus spp.) while other one (Streptococcus spp.) is catalase negative. If gas formation (O2) is observed in the form of bubbles, then it ensures that the sample of bacteria has a catalase; it is an indication of presence of Staphylococcus spp. Otherwise, on no gas formation, the sample contains Streptococcus spp. Non-selective medium is employed when organisms are present in low numbers. This also provides an indication about the type of organism present in the sample. The use of selective medium is to isolate the desired organism present in the mixed sample Nutrient agar is ideal as a non-selective culture medium to grow a large variety of microorganisms. In order to isolate microorganism from the agar plate, the part of colony is taken to a new agar plate. The streak-plate method can be employed as it reduces density of the microorganisms on the surface of the agar. This facilitates to obtain the distinct colonies of the microorganisms of our interest by using selective media (Selective and Differential Media 2012) Selective media inhibit the growth of some organism while promote growth of others. Selective inhibition is done by adding salts, dyes or specific inhibitors affecting the metabolism of the organisms. Crystal violet or penicillin will inhibit the growth of Gram-positive bacteria. Based on this philosophy, Tellurite agar is employed as media to identify for Gram-positive organisms. When gram negative organisms are to be selected or identified, the agar with penicillin (5-50- units/ml) is used (Selective and Differential Media 2012). Selective but differential media are

Bulling in NYC School Research Paper Example | Topics and Well Written Essays - 2500 words

Bulling in NYC School - Research Paper Example This essay approves that researchers have not agreed on the actual definition of bullying. There are definitions which have been in use and are worthy of quote here. Bullying is defined in a number of ways. Experts believe that there has been no clear definition of the term bullying. Bullying is also known as peer victimization and peer harassment. It is an intentional act of harming somebody by means of verbal, physical, sexual assault, or other forms of harassment. Bullying at school is believed a universal social malady. In many instances, bullies are stronger and more powerful than their victims, and the situation has the tendency to be repetitive. The study of bullying involves studies of children’s temperament. Bullying is peer abuse because it involves people in the same setting, students in the same school, or people who should have considered themselves companions with the same purpose and that is learning. This report makes a conclusion that that bullying is a â€Å"social sickness† that needs to be cured. And it is getting serious every day. It’s time authorities and the many stakeholders concerned with the welfare of the young to bond together and find effective means to heal this social malady. The young are victimized. Parents feel that their children are not anymore secured inside the school, a place where they ought to experience positive and moral values and learn good things in life. But it seems, schools are not anymore safe for the young.