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131.
132.
IAN C. ROBERTSON 《Physiological Entomology》1998,23(1):75-80
Abstract. In a pattern that is typical for bark beetles, the lateralis medius flight muscle of male pine engravers, Ips pini Say (Coleoptera: Scolytidae), was found to decrease four-fold in volume (from mean ± SE = 1.36 ± 0.06 × 10?2 mm3 to 0.34 ± 0.06 × 10?2 mm3) within five days of the initiation of breeding galleries, and then to regenerate gradually to functional capacity during subsequent weeks. Although there was considerable variation in the timing and extent of flight muscle regeneration in males, this variation was not a consequence of differences between small (length < 4.0 mm) and large (length ≥ 4.0 mm) males. Two subsequent experiments revealed that male pine engravers can control the timing of flight muscle regeneration. In the first experiment, the flight muscles of males that were denied mates degenerated within 5 days of gallery initiation, but then showed complete regeneration 5 days later. In the second experiment, mated males that were removed from their breeding galleries (to simulate breeding failure) also showed extensive muscle degeneration 5 days after gallery initiation, but then regenerated their flight muscles to functional capacity by the tenth day. The ability of males to regenerate their flight muscles in response to conditions at the gallery is probably adaptive because it allows them to fly in search of new breeding opportunities when they are unable to attract mates or when breeding attempts fail. 相似文献
133.
The auditory sensitivity of adult mice has been investigatedusing a method that has not been previously described. Thismethod involves recording the electromyogram (EMC) from thepost-auricular muscles in response to tonal stimuli. The preliminaryresults presented here show a secondary, high-frequency peakof sensitivity in the audiogram, which approximately correspondsto the frequency of sound emitted by that species; this confirmsthe findings of previous workers. The advantages and disadvantagesof using the post-auricular EMG response as a measure of auditorysensitivity are briefly discussed in comparison with other behavioraland physiological methods. 相似文献
134.
The discovery of induced pluripotent stem (iPS) cells in 2006 was heralded as a major breakthrough in stem cell research. Since then, progress in iPS cell technology has paved the way towards clinical application, particularly cell replacement therapy, which has refueled debate on the ethics of stem cell research. However, much of the discourse has focused on questions of moral status and potentiality, overlooking the ethical issues which are introduced by the clinical testing of iPS cell replacement therapy. First‐in‐human trials, in particular, raise a number of ethical concerns including informed consent, subject recruitment and harm minimisation as well as the inherent uncertainty and risks which are involved in testing medical procedures on humans for the first time. These issues, while a feature of any human research, become more complex in the case of iPS cell therapy, given the seriousness of the potential risks, the unreliability of available animal models, the vulnerability of the target patient group, and the high stakes of such an intensely public area of science. Our paper will present a detailed case study of iPS cell replacement therapy for Parkinson's disease to highlight these broader ethical and epistemological concerns. If we accept that iPS cell technology is fraught with challenges which go far beyond merely refuting the potentiality of the stem cell line, we conclude that iPS cell research should not replace, but proceed alongside embryonic and adult somatic stem cell research to promote cross‐fertilisation of knowledge and better clinical outcomes. 相似文献
135.
The moral importance of the ‘intention–foresight’ distinction has long been a matter of philosophical controversy, particularly in the context of end‐of‐life care. Previous empirical research in Australia has suggested that general physicians and surgeons may use analgesic or sedative infusions with ambiguous intentions, their actions sometimes approximating ‘slow euthanasia’. In this paper, we report findings from a qualitative study of 18 Australian palliative care medical specialists, using in‐depth interviews to address the use of sedation at the end of life. The majority of subjects were agnostic or atheistic. In contrast to their colleagues in acute medical practice, these Australian palliative care specialists were almost unanimously committed to distinguishing their actions from euthanasia. This commitment appeared to arise principally from the need to maintain a clear professional role, and not obviously from an ideological opposition to euthanasia. While some respondents acknowledged that there are difficult cases that require considered reflection upon one's intention, and where there may be some ‘mental gymnastics,’ the nearly unanimous view was that it is important, even in these difficult cases, to cultivate an intention that focuses exclusively on the relief of symptoms. We present four narratives of ‘terminal’ sedation – cases where sedation was administered in significant doses just before death, and may well have hastened death. Considerable ambiguities of intention were evident in some instances, but the discussion around these clearly exceptional cases illustrates the importance of intention to palliative care specialists in maintaining their professional roles. 相似文献
136.
IAN M. KING 《Bioacoustics.》2013,22(1):19-29
ABSTRACT Although chorusing behaviour has been reported previously in six species of corixid water bugs, including one European species of Micronecta, no analysis of chorusing has been published for Micronecta. Studies of a large pond in SE Australia show that chorusing occurred in the most common species of Micronecta in the study area, M. concordia. Pulse-trains synchronized with those of other individuals nearby were the predominant acoustic output of M. concordia males throughout the stridulating season, from mid-winter to mid-summer. At the start of the season, chorusing began with an exponential increase in the percentage of synchronized signals over a period of six days. 相似文献
137.
IAN BROCKINGTON PRABHA CHANDRA HOWARD DUBOWITZ DAVID JONES SUAAD MOUSSA JULIET NAKKU ISABEL QUADROS FERRE 《World psychiatry》2011,10(2):93-102
This guidance details the needs of children, and the qualities of parenting that meet those needs. Parental mental disorders can damage the foetus during pregnancy through the action of drugs, prescribed or abused. Pregnancy and the puerperium can exacerbate or initiate mental illness in susceptible women. After their birth, the children may suffer from the social disadvantage associated with severe mental illness. The parents (depending on the disorder, its severity and its persistence) may have intermittent or prolonged difficulties with parenting, which may sometimes result in childhood psychological disturbance or child maltreatment. This guidance considers ways of preventing, minimizing and remedying these effects. Our recommendations include: education of psychiatrists and related professions about the effect of parental mental illness on children; revision of psychiatric training to increase awareness of patients as caregivers, and to incorporate relevant assessment and intervention into their treatment and rehabilitation; the optimum use of pharmacological treatment during pregnancy; pre-birth planning when women with severe mental illness become pregnant; development of specialist services for pregnant and puerperal women, with assessment of their efficacy; community support for parenting by mothers and fathers with severe mental disorders; standards of good practice for the management of child maltreatment when parents suffer from mental illness; the importance of multi-disciplinary teamwork when helping these families, supporting their children and ensuring child protection; the development of child and adolescent mental health services worldwide. 相似文献
138.
JAIME PUÉRTOLAS ROSALÍA ALCOBENDAS JUAN J. ALARCÓN IAN C. DODD 《Plant, cell & environment》2013,36(8):1465-1475
To determine how root‐to‐shoot abscisic acid (ABA) signalling is regulated by vertical soil moisture gradients, root ABA concentration ([ABA]root), the fraction of root water uptake from, and root water potential of different parts of the root zone, along with bulk root water potential, were measured to test various predictive models of root xylem ABA concentration [RX‐ABA]sap. Beans (Phaseolus vulgaris L. cv. Nassau) were grown in soil columns and received different irrigation treatments (top and basal watering, and withholding water for varying lengths of time) to induce different vertical soil moisture gradients. Root water uptake was measured at four positions within the column by continuously recording volumetric soil water content (θv). Average θv was inversely related to bulk root water potential (Ψroot). In turn, Ψroot was correlated with both average [ABA]root and [RX‐ABA]sap. Despite large gradients in θv, [ABA]root and root water potential was homogenous within the root zone. Consequently, unlike some split‐root studies, root water uptake fraction from layers with different soil moisture did not influence xylem sap (ABA). This suggests two different patterns of ABA signalling, depending on how soil moisture heterogeneity is distributed within the root zone, which might have implications for implementing water‐saving irrigation techniques. 相似文献
139.
Radio-tagged Nightjars Caprimulgus europaeus nesting in conifer plantation clearings and on lowland heath in Dorset travelled an average of 3.1 km away from their nesting areas at night to atypical habitats, presumably to feed. Comparison of habitat availability with use showed that Nightjars preferred deciduous or mixed woodland habitats, while they avoided conifer plantations and arable or improved grassland. Absence from the nesting area was recorded on 72 % of bird-nights and birds were least likely to be away during the middle third of the night. The use of atypical habitats may have implications for Nightjar conservation. 相似文献
140.