Temperature dependent mortality and behavioral changes in a freshwater mussel Lamellidens marginalis to dimethoate exposure.

Temperature is a crucial determinant of biogeography, directly affecting the behavioral responses of the organisms. An acute static bioassay was conducted to evaluate the effect of temperature on dimethoate toxicity in a freshwater mussel Lamellidens marginalis. The mussel, were exposed for 96 hr at different concentrations of dimethoate (155.00, 160.00, 165.00, 170.00, 175.00, 180.00, 185.00, 190.00, 195.00, and 200.00 mgl-1) in the month of January when water temperature was 14.9±1.20C and at concentration 35.00, 37.00, 39.00, 41.00, 43.00, 45.00, 47.00, and 49.00 mgl-1 in the month of August when the water temperature was 28.0±0.50C. The LC50 values were calculated from the mortality data obtained (using EPA-Probit analysis version 1.5, statistical software). The 96 hr LC50 value recorded at higher temperature was 36.34mgl-1 and at low temperature was 163.59 mgl-1. The mussel exposed at higher temperature showed more sensitive behavioral responses like huge mucus secretion, sudden closure of shell valves, quick post-mortem changes and increased oxygen consumption in comparison to exposure at low temperature. Therefore, the increasing threat of global warming increases the risk of pesticide toxicity in the exposed organisms.

Effect of examination stress on mood, performance and cortisol levels in medical students.

Stress produces definable mental and physiological reactions in the body. Mild stress is beneficial in cognitive tasks and performance but persistently high stress may lead to neuropsychiatric illnesses like anxiety and depression. Examinations act as stressor and activate hypothalamicpituitary adrenal axis causing an increase in cortisol level, which is reflected in saliva. Present study was done on 35 medical students. Their mood parameters were assessed, using Depression Anxiety Stress Scale (DASS) scoring, and salivary cortisol levels using quantitative ELISA. Subjects were evaluated for mood parameters two times, one during relaxed state (with no examinations in preceding 2 weeks and in coming 2 weeks) and another during stressed state (on the day of viva voce examination). The levels of mood parameters and salivary cortisol were significantly raised during examination stress. The changes in stress level significantly correlated with change in levels of anxiety and salivary cortisol though there was no significant effect on the performance. Males and females showed similar changes in mood parameters. This study suggests that as examinations act as unavoidable stressors, the medical educators as well as students should be made aware of the negative consequences of stress faced during medical training. Efficient relaxation program as well as counseling services should be provided to stressed students so that they are able to cope better with examination stress.

A study on quality of life in patients following myocardial infarction.

Subjective well being has been widely researched in the past few decades and in practical terms it is a term that encompasses the various ways people evaluate their lives including concepts such as life satisfaction, work and health etc. Since, it is well known, that psychological factors including stress, anxiety, poor sleeping habits etc are known to be important causes of life style disorders like myocardial infraction, we started with the hypothesis that subjective well being of post acute MI patients must be poorer compared to normal subjects in the same age group. A comparative study between normal subjects and post acute myocardial infarction patients was undertaken to compare their subjective well being and current mental health status, at Safdarjung Hospital, New Delhi using standardized questionnaires. The results showed significantly higher negative affect like inadequate mental mastery over immediate environment, perceived ill health including disturbed sleep, deficiency in social contacts, and a general ill being about life in the MI group (P<0.05). Regarding the positive emotions, the normal subjects showed a higher general well being positive affect, higher transcedence and higher perception of social support. (P<0.05). The GHQ also yielded significantly better sleeping habits, less anxiety, better perception of health and more satisfaction with life in the normal subjects compared to post acute MI patients. (P<0.05).

Effect of protein malnutrition on the intestinal absorption of monosaccharides in rats in vivo.

The present study was planned to elucidate the role of protein malnutrition on the intestinal absorption of monosaccharides particularly--glucose and xylose, in inbred female albino rats. The experimental rats were fed with protein deficient diet containing 3% protein, whereas the control rats were given a diet containing 18% protein. The study on intestinal absorption of monosaccharides was conducted on both the groups of rats after the 7th and 15th day of receiving respective diets. The results indicated no significant impairment of glucose absorption of experimental rats fed 3% diet for 7 days as compared to the controls. However a 42% decrease in glucose absorption was observed when the animals were fed with the same diet for 15 days. The impairment was significant in all segments of intestine suggesting diminution in the absorption capacity of small intestine in malnutrition perhaps as a result of some permanent injury to mucosal cells of small intestine. Regarding xylose absorption, in experimental rats an increase of intestinal uptake was noticed in most of the segments of small intestine as compared to control rats.