The present thesis and series of studies explores the underlying cognitive and neuropsychological processes that underlies propensity for aggressive response in adult men and women, both sober and intoxicated. Previous research demonstrated that poor executive functioning, either pre-existing (idiopathic) or induced by alcohol-intoxication, was associated with heightened aggressive responses. The first study demonstrates that although cognitively impaired when alcohol intoxicated, men with above average pre-alcohol Executive Cognitive Functioning (ECF) do not act aggressively if they are properly motivated to remain non-aggressive, suggesting some ability to use residual executive function. The second study directly compares the aggression-eliciting effects of alcohol in both men and women, an under-investigated issue. Results indicate that aggression levels in the women are not significantly less than those of men, and that alcohol-intoxication is not as predictive a factor in women as in men. The third study, a post-hoc analysis of the second, indicates that like for men, executive function level in women is highly related to propensity for aggressive response, in fact far more predictive than acute alcohol-intoxication. The fourth study was intended to investigate a possible behavioural explanation for the ECF-aggression relationship. Specifically, this study was designed to assess whether the aggression manifested by individuals with poor ECF was rapid or impulsive, i.e. due to a disinhibition process. Contrary to this popular contention, this study demonstrates that when faced with complex, social interactions, low-ECF individuals act aggressively, but only after a somewhat slow period of apparent contemplation. These findings and others conducted by the author are discussed in a speculative model of the ECF-aggression relationship. Means by which to test this model are proposed, as are other theoretical implications of the work.

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I examined the effect of heterogeneity in the thermal environment on the life history of the cricket Allonemobius fasciatus. Variation in the life cycle was the result of a mixture of phenotypic plasticity and genetic differentiation in phenology-related traits along a latitudinal cline in growing season. Females from a partially bivoltine population have a conditional life history because they can adjust the proportion of diapause eggs in accordance with the likelihood that a second generation will grow and reproduce before winter. The thermal environment is not variable enough to result in the evolution of a marked bet hedging response, as is predicted by theory. A quantitative genetic analysis of the diapause reaction norm revealed significant heritabilities as well as correlations with other traits that could be related to common physiological mechanisms.

No description available.

Utilizing non-metabolizable substrates as valuable tools to differentiate between transport and subsequent metabolism, the possibility was explored whether there was a relationship between the sodium requirement by marine bacterial cella for growth and a sodium requirement for uptake of substrates. Various aspects of the transport phenomenen in these organisms were studied and the following findings are claimed to constitute a contribution to knowledge. [...]

To examine the effect of diet fat type on rates of cholesterol synthesis and esterification during feeding and fasting, nine healthy male subjects were fed solid-food diets of 40% fat as predominantly either olive oil (MONO), safflower-oil margarine (POLY), or butter (SAT). At the end of each two-week diet trial, subjects were given deuterium (D) oxide orally and de novo synthesis was measured from D incorporation into cholesterol and interpreted as rates of fractional synthesis (FSR) (pools/day) into the rapidly exchangeable free cholesterol (FC) pool. Absolute synthesis rates (ASR) were calculated as the product of FSR and the FC pool. Pool size for each subject was obtained from analysis of the specific activity decay curve of an intravenous injection of 4-14C-cholesterol over nine months. Synthesis was measured over two consecutive 12-h fed periods followed by two consecutive 12-h fasted periods. Serum samples were also assayed for lathosterol concentration, an index of cholesterol synthesis. Serum cholesterol and non-HDL cholesterol concentrations were highest on the SAT diet, lowest (P<0.001) on the POLY diet and intermediate on the MONO diet, triglyceride levels were greater (P<0.03) on the SAT diet than on the POLY diet, and HDL levels were lowest (P<0.05) on the SAT diet and highest on the MONO diet. Cholesterol D enrichment and FSR during each 12-h period were greater (P<0.014) on the POLY diet than on the SAT diet; MONO enrichment and FSR were not significantly different from those on the other two diets. Similar results were obtained for rates of cholesterol esterification (P<0.001). Deuterium enrichment data suggested, and lathosterol data confirmed, that free cholesterol synthesis was greater during the fed period than during the fasted period (P<0.01); however, this could not be confirmed for rates of cholesterol esterification. Results suggest that POLY fat feeding augments de novo cholesterol synthesis without adverse effects on total serum cholesterol concentrations, and that the deleterious effects of SAT fat on serum cholesterol are not brought about by augmented de novo synthesis. Finally, the combination of deuterium incorporation and mathematical modelling produces estimates of daily cholesterol synthesis which are compatible with those invoked by more laborious techniques.

The classical paradigm of radiation biology is based on the notion that ionizing particle has to traverse a nucleus of a living cell in order to damage genetic material either directly or via production of short living free radicals. After DNA damage is introduced it can be either safely repaired and the cell can continue divisions unaltered; or it can result in a failure to repair and cells death; or finally, upon misrepair, the cell would be carrying genetic alteration that could result in cancer or developmental abnormality. Therefore modern risk estimations are based on the notion that nucleus is the true target of radiation effects and those are essentially stochastic with linear dependence on the dose. During the last two decades or so, a different idea was developed based on the observation that irradiated cells can communicate radiation induced stress signals to their unaffected neighbors and themselves become reprogrammed to maintained abnormal radiation-induced phenotype across multiple cellular divisions. Even more astonishingly this phenotype maybe transmitted by irradiated germ cells to unexposed progeny. Here we suggest that these non-targeted effects are maintained by epigenetic mechanisms and examine epigenetic underpinnings of bystander and transgenerational effects in vivo. / xi, 190 leaves ; 28 cm

Previous studies in our laboratory have indicated that anesthetic block of neural activity at discrete sites within the limbic system, including the lateral hypothalamus and anterior cingulum bundle, causes a significant long-lasting analgesia during the formalin test. In this experiment, the local anesthetic lidocaine was microinjected into the dentate region of the hippocampus, an important limbic structure presumed to subserve the affective-motivational aspects of pain. The dentate gyrus is strategically situated at a point of convergence of widespread polysensory cortical input to the hippocampus, to allow modulation of cortical signals before they diverge into numerous limbic circuits. The results indicate that anesthetic block of the anterior region of the dentate gyrus produces analgesia in the rat during the formalin test. The analgesia produced by this procedure became apparent 30 minutes after regional block contralateral to the site of injury and persisted for the duration of the test period. These data provide further evidence that limbic forebrain structures are involved in pain and analgesia.

No description available.

Two studies are presented which investigated the relationship between oral contraceptives (o.c.s) and premenstrual changes in mood and physical state. The retrospective pilot study examined possible differences in symptom-reporting between groups of pill-users and non-users. Women using o.c.s had lower severity scores on a number of physical and mood-related symptoms compared to non-users. In the prospective study, eighty-two women with complaints of moderate to severe premenstrual symptoms were recruited for a double-blind, controlled trial of a triphasic o.c. Subjects made daily ratings of symptoms for one to two baseline cycles and were then randomly assigned to receive either placebo or the o.c. for three treatment cycles. Prospective assessment of symptoms was made using a variety of measures, and circulating levels of estrogen and progesterone were measured at three points during the cycle. Bloating and breast pain showed a greater reduction in the o.c. group than in the placebo group. In a subgroup of women with premenstrual depressive change, the o.c. also produced greater improvement in a number of symptoms compared to placebo. For all other symptoms, there was no beneficial effect of the active treatment over placebo. Women who received o.c.s reported decreased sexual interest after starting the pill. Possible hormonal mechanisms for these effects are discussed.