Stress Essay Example | Topics and Well Written Essays - 750 words - 3

Stress - Essay Example In general, stress comes in numerous forms. Working individuals may experience work-related stress whereas other people may have to go through physical stress related to illness or hormonal changes and emotional stress such as grievance due to the death or loss of a special someone. Stressors are commonly classified as external or internal. (Ward et al., 2003) External stressors may come from extreme physical condition like chronic pain and hot or cold temperatures as well as stressful psychological environments caused by poor working environment or being in an abusive relationship. On the other hand, internal stressors can be related to physical abnormalities related to inflammation or infection. It can also be caused by psychological factors such as excessive worrying. Even though the role of emotional regulation between stress and hypertension remains unclear (Gerin et al., 2002), several studies show that negative emotions such as anger, anxiety and frustrations could increase the physiological stress which normally causes a person to experience hypertension. (Lawler et al., 1998; Miller et al., 1998) These internal or external stressors, regardless of whether the stress occurs over a short- or long-term period, could negatively affect people physically, mentally, and emotionally. Regardless of age, several studies show that a stressful condition could cause a person to experience a significant decrease in the performance of their declarative memory (Lupien et al., 1997; Kirschbaum et al., 1996; Newcomer et al., 1995) aside from the fact that it could increase a person’s risk of developing type II diabetes (Harris and White, 2007). Stress has also a huge impact on a person’s heart and circulation system especially among postmenopausal women. (Kivimà ¤ki et al., 2002; Bairey Merz et al., 1998) In some cases, stress causes a person to experience

Orthomyxovirus (influenza) Research Paper Example | Topics and Well Written Essays - 750 words

Orthomyxovirus (influenza) - Research Paper Example Severe, hospitalizations as well as death normally occur when such pandemic occurs. Though, the pandemic is less serious, it causes extensive morbidity when it occurs. Wilson and von Itzstein points out that two attributes of the virus occurring during replication and its evolution are the ones that makes this virus to be successful in its epidemiological (165). These attributes are its ability to circulate freely in the avian water reservoirs, and emerge without being predicted and spread easily in people. The second attribute is its comparatively quick and unpredictable antigenic transformation that is associated with its evolution the moment they infect the human population. This short paper details some aspects of the influenza virus. Discuss the virus morphology Influence virus is highly pleomorphic; this implies that the envelope of the virus can appear in spherical or filamentous shapes. However, as Jin and Leser (98) explain, the virus’s has a spherical morphology with 50 to 120 nm particles in diameter. The virus also has a filamentous virions measuring 20 nm in diameter, while the measure 200 to 300 nm long. At the same time, the virus has some 500 distinctive spear-like surface protrusions that emerge on the envelope each protruding about 10 nm. Other types of the virus fro example hemagglutinin esterase (HEP) are thickly dispersed on surface, while others like hemagglutinin (HA) spaced sparsely apart. Various strains of this virus differ in the way they form their filaments. Genome: Ito and Gorman (66) explains that influenza A and B viruses have six to eight fragments of linear single stranded RNA, each of this RNA has one or more protein, but type C has got seven fragments. Accordingly, the whole length of genome measures abo ut 10000 nucleotides long. However, the length of genome varies extensively among these three groups of viruses, the difference sometimes occurs even in the same type among the various strains (Jin, and Leser, 99). Structure: the influence has an orthomyxovirus comprising of an envelope, layer of protein, polymerase complex and a nucleocapsid, and has a capsid envelop. Replication There have been extensive studies done on replication of influenza viruses mainly on type A strains, thus replication discussed in this section will mainly be linked to this strain. Ito and Gorman points out that the influenza virus is able to infect a cell by binding it’s HA or HEF protein a cell’s protein receptor (67). The virus then goes through the process of endocytosis, during this process the low PH observed in the late phase of endocytosis results in conformational transformation in the cleavage –activated HA. This leads to a joining (fusion) of the viral and vesicular film. T he fusion of the viral and vesicular discharges its contents of the viruses into the cell’s cytoplasm. Before the fusion takes place, M2 protein from type B viruses produces protons in the within of virion. Transmission The influenza viruses spread its disease via airborne. Accordingly, Hilleman (144) explains that the viruses are deposited in the lower part of the respiratory tract, however, they main part that they infect is the tracheobronchial mucosa. According to Hilleman the virus takes about six hours to replicate and the end of the process it kills the cell (145). The virus then attaches itself to the permissive cell through the hemaggulitinin; this is attached to the cell membrane that has glycolipids that have N-acetylneuraminic acid that has a receptor, where the virus is attached. After this the virus is then surrounded by the pinocytosis and moves to the endosomes. The endosomes have acid and this makes the virus envelope to merge with the plasma layer of the end osome, the virus then