Pleistocene glaciation events shape genetic structure across the range of the American lobster, Homarus americanus

A north/south discontinuity along the northeastern coast of North America in the genetic structure of the American lobster (Homarus americanus) was detected using a suite of 13 microsatellite loci assessed using spatial analyses. Population genetic data laid over existing data on physiographic changes and sea-surface temperatures were used to reconstruct the Pleistocene distribution of this species. A postglacial northern-edge colonization model best explains the relative genetic homogeneity of the northern region compared to the southern region centred in the Gulf of Maine. Population genetic analyses identified significant structure (range of standardized theta 0-0.02) but no significant evidence for isolation by distance. The novel application of spatial genetic analyses to a marine species allowed us to interpret these results by providing a greater insight into the evolutionary factors responsible for shaping the genetic structure of this species throughout is natural range.

Thisness and Events

This essay is an investigation into the existence of primitive thisness, i.e. the property of being a particular individual. I begin with a look at what is commonly taken to be the test for primitive thisness, namely, the failure of application of the principle of the Identity of Indiscernibles for some class of individuals. The two classes that I look at are those of material objects and events. I then discuss Hacking’s objection to the general project of seeking counterexamples to the Identity of Indiscernibles, and consider a response due to Adams. I argue that Hacking’s objection does, indeed, count against the instantiation of thisness by material objects. I go on to argue, however, that Hacking’s objection does not hold against the instantiation of thisness by events, and that this is due to a fundamental disanalogy between space and time.

Current transients in the small salient-pole alternator caused by sudden short-circuit and synchronisation events

Small salient-pole machines, in the range 30 kVA to 2 MVA, are often used in distributed generators, which in turn are likely to form the major constituent of power generation in power system islanding schemes or microgrids. In addition to power system faults, such as short-circuits, islanding contains an inherent risk of out-of-synchronism re-closure onto the main power system. To understand more fully the effect of these phenomena on a small salient-pole alternator, the armature and field currents from tests conducted on a 31.5 kVA machine are analysed. This study demonstrates that by resolving the voltage difference between the machine terminals and bus into direct and quadrature axis components, interesting properties of the transient currents are revealed. The presence of saliency and short time-constants cause intriguing differences between machine events such as out-of-phase synchronisations and sudden three-phase short-circuits.

Response shift in the assessment of quality of life among people attending cardiac rehabilitation

Objectives: To examine whether any response shift in quality of life assessment over the course of a cardiac rehabilitation programme could be explained by changes in individuals’ internal standards (recalibration), values (reprioritization) and/or conceptualization of quality of life and the extent to which any response shift could be explained by health locus of control, optimism and coping strategy. Design: Longitudinal survey design. Methods: The SEIQoL-DW was administered at the beginning and end of a cardiac rehabilitation programme. At the end of the programme, the SEIQoL-DW then-test was also administered to measure response shift. A total of 57 participants completed these measures and other measures to assess health locus of control, optimism and coping. Results: Response shift effects were observed in this population mainly due to recalibration. When response shift was incorporated into the analysis of QoL a larger treatment effect was observed. Active coping as a mechanism in the response shift model was found to have a significant positive correlation with response shift. Conclusion: This study showed that response shift occurs during cardiac rehabilitation. The occurrence of response shift in QoL ratings over time for this population could have implications for the estimation of the effectiveness of the intervention.

Perceptions of exercise among people who have not attended cardiac rehabilitation following myocardial infarction.

Perceptions of exercise among nonattenders of cardiac rehabilitation (CR) were explored using semistructured interviews. Analysis indicated that participants did not recognize the cardiovascular benefits of exercise, and perceived keeping
active through daily activities as sufficient for health. Health professionals were perceived to downplay the importance of exercise and CR, and medication was viewed as being more important than exercise for promoting health. The content of CR programmes and the benefits of exercise need to be further explained to patients post-MI, and in a manner that communicates to patients that these programmes are valued by significant others, particularly health professionals.