Young doctors are active members of Facebook. A quarter of the doctors in our survey sample did not use the privacy options, rendering the information they revealed readily available to a wider public. This information, although it included some healthy behaviours, also revealed personal information that might cause distress to patients or alter the professional boundary between patient and practitioner, as well as information that could bring the profession into disrepute (e.g. belonging to groups like 'Perverts united'). Educators and regulators need to consider how best to advise students and doctors on societal changes in the concepts of what is public and what is private.
Abstract:The nototheniid Pleuragramma antarcticum (Boulenger, 1902), is the dominant pelagic fish in waters of the continental shelf in High Antarctic regions. Larvae and juveniles of this species comprise the majority of ichthyoplankton at many locations around Antarctica including the Weddell Sea and the western Ross Sea, where it may amount to 98% of the ichthyoplankton. Its life cycle has been the subject of a number of studies but spawning and embryological development are still uncertain. Eggs with embryos and newly hatched larvae of P. antarcticum were collected in November 2002 near the Italian Antarctic station at Terra Nova Bay through holes drilled in the sea ice. Eggs and yolk-sac larvae were floating among the platelet ice below the solid cap of congelation ice. Eggs were 2.2-2.5 mm in diameter and contained embryos at an advanced stage of development. Hatching occurred from mid-November onwards, and newly hatched larvae averaged 9.3 mm SL. This paper provides the detailed description of embryos and newly hatched larvae in terms of pigmentation pattern and morphometric characteristics, thus allowing a significant advance in our understanding of the early life history of P. antarcticum in the Ross Sea, and extending the knowledge of the life cycle of this key Antarctic species.
The suitability of the lateral line system of fish and aquatic amphibia for the detection of planktonic prey was examined in the antarctic fish Pagothenia borcgrevinki (family Nototheniidae). The best responses of primary afferent lateral line neurons to waterborne vibrations were recorded at frequencies within the range of those produced by swimming crustacea. Simultaneous recordings from a swimming zooplankter held close to the fish and from primary afferent neurons provided direct confirmation that swimming movements of crustaceans are a potent natural stimulus of the lateral line system.
Temperature change has a major impact on the function of the nervous system and its components, including altering synaptic gain and changing synaptic and conduction delays. Although many animals are subject to changes in body temperature, the degree of temperature change actually experienced by many poikilotherms is not well documented. The fact that many animals continue to exhibit coordinated sensorimotor function during changes in body temperature indicates that some form of temperature compensation has occurred within the nervous system. Compensations may occur automatically (opposing effects of temperature offsetting each other), they may be an inherent property of closed-loop systems, or they may be effected by more sophisticated control mechanisms such as those of the vertebrate cerebellum.
there is evidence that this may have occurred about The subfamily of fishes Trematominae is endemic to 12-14 million years ago (MYA) (Eastman, 1993; the subzero waters of Antarctica and is part of the Bargelloni et al., 1994).
larger notothenioid radiation. Partial mitochondrialThere may have been a suite of factors which allowed sequences from the 12S and 16S ribosomal RNA (rRNA) the notothenioids, in particular, to evolve to such domigenes and a phylogeny for 10 trematomid species are nance in the Southern Oceans. Several authors have presented. As has been previously suggested, two taxa, suggested that speciation within the group could have Trematomus scotti and T. newnesi, do not appear to be been the result of large-scale disruptions in the Antarcpart of the main trematomid radiation. The genus Pa-tic ecosystem during the Miocene (Clarke, 1983). The gothenia is nested within the genus Trematomus and isostatic pressure from the accumulation of ice during has evolved a unique cyropelagic existence, an associ-the early Miocene (25-15 MYA) left the continental ation with pack ice. Using a mitochondrial rRNA mo-shelf unusually small, deep, and lacking extensive tolecular clock rate of 0.14% transversion changes per pography (Andersen, 1991). It is likely that the presmillion years, the average age of the trematomids is es-ence of ice, which destroyed high coastal habitats and
In young (4-week-old) male and female spontaneously hypertensive (SH) rats, ethanol metabolic rate in vivo and hepatic alcohol dehydrogenase activity in vitro are high and not different in the two sexes. In males, ethanol metabolic rate falls markedly between 4 and 10 weeks of age, which coincides with the time of development of sexual maturity in the rat. Alcohol dehydrogenase activity is also markedly diminished in the male SH rat and correlates well with the changes in ethanol metabolism. There is virtually no influence of age on ethanol metabolic rate and alcohol dehydrogenase activity in the female SH rat. Castration of male SH rats prevents the marked decrease in ethanol metabolic rate and alcohol dehydrogenase activity, whereas ovariectomy has no effect on these parameters in female SH rats. Chronic administration of testosterone to castrated male SH rats and to female SH rats decreases ethanol metabolic rate and alcohol dehydrogenase activity to values similar to those found in mature males. Chronic administration of oestradiol-17beta to male SH rats results in marked stimulation of ethanol metabolic rate and alcohol dehydrogenase activity to values similar to those found in female SH rats. Chronic administration of ethanol to male SH rats from 4 to 11 weeks of age prevents the marked age-dependent decreases in ethanol metabolic rate and alcohol dehydrogenase activity, but has virtually no effect in castrated rats. In the intoxicated chronically ethanol-fed male SH rats, serum testosterone concentrations are significantly depressed. In vitro, testosterone has no effect on hepatic alcohol dehydrogenase activity of young male and female SH rats. In conclusion, in the male SH rat, ethanol metabolic rate appears to be limited by alcohol dehydrogenase activity and is modulated by testosterone. Testosterone has an inhibitory effect and oestradiol has a testosterone-dependent stimulatory effect on alcohol dehydrogenase activity and ethanol metabolic rate in these animals.
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