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Behavioural Aspects (behavioural + aspect)
Selected AbstractsA quantitative study of day,night changes in the spatial distribution of insects in a stony streamJOURNAL OF ANIMAL ECOLOGY, Issue 1 2002J. M. Elliott Summary 1As many invertebrates are nocturnal, their spatial distribution may change from day to night. This behavioural aspect of their population dynamics has been ignored, but is now examined for the first time by testing the hypotheses: (i) a power function was a suitable model for the spatial distribution of common species of Ephemeroptera, Plecoptera and Trichoptera in a stony stream; (ii) the spatial distribution varied between species but was similar within species for larvae greater and smaller than half-size; (iii) diurnal and nocturnal spatial distributions were significantly different for each species. To ensure that the conclusions were consistent, large samples (n = 30) were taken near midday and midnight in April, June and November over 4 years. 2Twenty,one species were taken in sufficient numbers for the analyses; seven species were too sparse to be included. The first hypothesis was supported. A power function, relating spatial variance (s2) to mean (m), was an excellent fit in all the analyses (P < 0·001, r2 > 0·95), i.e. the spatial variance was density,dependent. The power b, often used as an ,index of aggregation', varied in the range 0·88,2·50. 3Most analyses supported the second hypothesis. For four species, the difference between the two size groups was just significant (P < 0·05), but was due to inadequate data for three species. Large larvae of the fourth species, the caddis Odontocerum albicorne, were less aggregated than small larvae at night, and were the only group with a b -value less than one. 4The third hypothesis was partially supported. The distribution did not change significantly (P > 0·05) for nine species; five burrowers in gravel, moss or mud, two highly mobile predators, one sedentary, case,building, Trichoptera species, and one net,spinning Trichoptera species. Aggregation was reduced significantly (P < 0·001) at night for four species, all case,building Trichoptera larvae. Aggregation increased significantly (P < 0·001) at night, except at low densities, for the remaining eight species, one being a nocturnal predator and the others being herbivorous species; all occurred frequently in night samples of invertebrate drift. Day,night changes in spatial distribution were therefore an essential part of the behavioural dynamics of 12 of the 21 species, and should be investigated in other species, including terrestrial species. [source] Recent advances in the neurophysiology of chronic painEMERGENCY MEDICINE AUSTRALASIA, Issue 1 2005Kylie Baker Abstract The chronic pain syndrome patient has become the ,leper' of emergency medicine. There are no emergency medicine guidelines and minimal research into managing this challenging group of patients. Objective:, To summarize the recent advances in laboratory research into the development of chronic pain that have relevance to emergency management. When the level of supporting evidence is low, it is imperative that emergency physicians understand the physiology that underpins those expert opinions upon which they base their treatment strategies. Methods:, Literature was searched via Medline, Cochrane, Cinahl, and PsycINFO from 1996 to 2004, under ,chronic pain and emergency management'. Medline from 1996 was searched for ,chronic pain and prevention', ,chronic pain and emergency' and ,chronic pain'. Bibliographies were manually searched for older keynote articles. Results:, Advances in understanding the biochemical changes of chronic pain are paralleled by lesser known advances in delineation of the corticol processing. Conclusions:, Drug manipulation causes complex action and reaction in chronic pain. Emergency physicians must also optimize cognitive and behavioural aspects of treatment to successfully manage this systemic disease. [source] Cognitive and behavioural characteristics are associated with personality dimensions in patients with eating disordersEUROPEAN EATING DISORDERS REVIEW, Issue 5 2003M. Vervaet DSM-IV categorizes eating disorders according to behavioural and cognitive characteristics. Based on personality-related and biological research, hypotheses have been formulated to explain differences in the symptomatology between the various types of eating disorders. Therefore, the study of the association between personality-related characteristics and behavioural and cognitive characteristics may contribute to our understanding of the causes and course of eating disorders. This study aimed, first, at describing personality characteristics (using Cloninger's Temperament and Character Inventory) in a group of eating disordered patients (n,=,272) according to the type of eating disorder. Three groups were compared: restricting anorexics (n,=,71), purging anorexics (n,=,84) and bulimics (n,=,118). Secondly, the association between personality characteristics and cognitive and behavioural aspects, using the Eating Disorders Inventory and the Dutch Eating Behaviour Questionnaire, was measured. In bulimics, positive correlations were found between novelty seeking on the one hand and external and emotional eating and bulimia on the other. Contrary to expectation, there was no significant correlation between novelty seeking and body dissatisfaction in bulimics. The significant difference between the restricting and purging type of anorexics regarding self-directedness, and restrained and emotional eating and drive for thinness corresponded with the significant negative correlation between these characteristics. Copyright © 2003 John Wiley & Sons, Ltd and Eating Disorders Association. [source] Ascending visceral regulation of cortical affective information processingEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2003Gary G. Berntson Abstract Over a century ago, William James proposed that strong emotions represent the perceptual consequences of somato-visceral feedback. Although the strong form of this conception is no longer viable, considerable evidence has accumulated indicating a range of visceral influences on higher neurobehavioural processes. This literature has only recently begun to consolidate, because earlier reports generally remained at the demonstration level, and pathways and mechanisms for such influences were uncertain. Recently, specific effects of visceral feedback have become apparent on cortical activity, cerebral auditory-evoked responses, anxiety, memory and behavioural aspects of immunological sickness. Moreover, considerable progress has been made recently in determining the specific neural pathways and systems underlying these actions, especially the role of noradrenergic projections from the nucleus of the tractus solitarius and the locus coeruleus to the amygdala in memory processes, and to the basal forebrain in the processing of anxiety-related information. The present paper highlights selected recent findings in this area, and outlines relevant structures and pathways involved in the ascending visceral influence on higher neurobehavioural processes. [source] How do floral display size and the density of surrounding flowers influence the likelihood of bumble bee revisitation to a plant?FUNCTIONAL ECOLOGY, Issue 1 2007T. T. MAKINO Summary 1Most pollination biologists have used the collective pollinator visits to a plant as the measure of its pollinator attraction. However, we know very little about how many returns by the same individuals compose these visits, and how far each visitor travels after leaving the plant. Such behavioural aspects of individual pollinators are essential to understand the patterns of pollen flow among plants. 2We observed plant visits by tagged bumble bees Bombus diversus in a field population of Cirsium purpuratum. By dissecting the collective visitation data into visits made by individual foragers, we addressed how ,visitor density' (number of individuals that visited a plant per 2 h) and ,individual visitation rate' (number of visits made by each individual per 2 h) are related to floral display size (number of flowering heads on a plant) and local flower density (number of flowering heads on neighbouring plants). We also tracked individual bees to determine how display size and local flower density of a plant influences its relative position in a bee's foraging area. 3Plants attracted both regular visitors (bees that visited a plant more than three times per 2 h) and occasional visitors (bees that visited a plant fewer than four times per 2 h). Densities of both types of visitors increased with floral display size, whereas only occasional visitor's density increased with local flower density. 4Individual bees preferred to visit central plants within their own foraging areas, plants with larger displays, and plants with lower local flower density. However, these preferences were independent from one another. Plants with large displays were not necessarily chosen by a bee as the centre of its own foraging area. On the other hand, plants with high local flower density were often located near the centre of a bee's foraging area. 5The observed pollinator movements have implications for pollen flow in the plant population. Plants with larger displays probably experience greater mate diversity by attracting more occasional visitors, but they also assure matings with particular plants by increasing returns from regular visitors. [source] Rethinking what constitutes suspended sedimentHYDROLOGICAL PROCESSES, Issue 9 2001Ian G. Droppo Abstract Although cohesive suspended sediment is now known to be transported primarily as flocculated material, there is still a misconception of what constitutes suspended sediment. Flocs represent a complex matrix of microbial communities, organic particles (e.g. detritus, extracellular polymers and cellular debris), inorganic particles (e.g. clays and silts) and substantial interfloc spaces (pores), which allow for the retention or flow through of water. Flocculation results in significant alteration of the hydrodynamics of the constituent particles (by modifying their effective size, shape, density and porosity), thereby affecting the transport of sediment and associated contaminants. The composition and structure of a floc is in a continuous state of change as the medium in which it is transported provides the floc with further building materials, energy, nutrients and chemicals for biological growth, chemical reactions and morphological development. As such, a floc's physical (e.g. transport), chemical (e.g. contaminant adsorption) and biological (community development and contaminant biotransformation) behaviour are also in a continuous state of change, with concomitant effects on their aquatic environment as a whole. Although it is recognized that floc form will influence floc behaviour, there is still a basic lack of knowledge of the complex links between the structural components of a floc and how their individual properties and behaviours in combination with others will influence a floc's physical, chemical and biological behaviour. This paper provides a comprehensive conceptual model that links the many interrelated structural components of typical flocs and their interrelated behavioural aspects, in order to enhance our understanding of what constitutes suspended sediment. Copyright © 2001 John Wiley & Sons, Ltd. [source] Subjective cognitive complaints, neuropsychological performance, affective and behavioural symptoms in non-demented patientsINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 1 2008Roberto Gallassi Abstract Objective Subjective cognitive complaints (SCC) have been previously investigated to establish whether they are risk factors for dementia, but no clear-cut conclusions have emerged. In this study non-demented patients with SCC were studied and the neuropsychological findings, affective and behavioural aspects and parameters with the highest correct classifications in discriminating patients who had only SCC but no objective clinical and neuropsychological impairment, i.e. no cognitive impairment (NCI) patients and those with objective neuropsychological deficits, namely patients with mild cognitive (MCI) were analyzed. Methods Consecutive non-demented outpatients with SCC were enrolled of over 9 months and examined using neuropsychological tests and scales for depression, anxiety and behaviour. Clinical criteria and neuropsychological test results were used to classify patients into groups of NCI, MCI and subtypes of MCI. Results Ninety-two patients with SCC were included; 49 of them had objective deficits (MCI patients), whereas 43 were without any clinical and cognitive impairment (NCI patients). These patients had lower age, higher education and better general cognitive indices than MCI patients who had higher caregiver distress, depression and irritability. The combination of a battery for mental deterioration and for behavioural memory assessment were the most discriminative in differentiating the two groups. Conclusions An objective cognitive impairment, reaching the criteria for a MCI diagnosis, was present in almost half of patients having SCC. MCI patients have more behavioural disturbances than NCI subjects. SCC should not be underestimated and appropriate neuropsychological assessment is required to reassure subjects with normal results and to identify patients with MCI. Copyright © 2007 John Wiley & Sons, Ltd. [source] Glamour Acquirers, Method of Payment and Post-acquisition Performance: The UK EvidenceJOURNAL OF BUSINESS FINANCE & ACCOUNTING, Issue 1-2 2003Sudi Sudarsanam We study the effect of different acquirer types, defined by financial status and their payment methods, on their short and long-term performance, in terms of abnormal returns using a variety of benchmark models. For a sample of 519 UK acquirers during 1983,95, we examine the abnormal return performance of acquirers based on their pre-bid financial status as either glamour or value acquirers using both the price to earnings (PE) ratio and market to book value ratio (MTBV). Value acquirers outperform glamour acquirers in the three-year post-acquisition period. One interpretation is that glamour firms have overvalued equity and tend to exploit their status and use it more often than cash to finance their acquisitions. As we move from glamour to value acquirers, there is a greater use of cash. Our results are broadly consistent with those for the US reported by Rau and Vermaelen (1998). However, in contrast to their study, we find stronger support for the method of payment hypothesis than for extrapolation hypothesis. Cash acquirers generate higher returns than equity acquirers, irrespective of their glamour/ value status. Our conclusions, based on four benchmark models for abnormal returns, suggest that stock markets in both the US and the UK may share a similar proclivity for over-extrapolation of past performance, at least in the bid period. They also tend to reassess acquirer performance in the post-acquisition period and correct this overextrapolation. These results have implications for the behavioural aspects of capital markets in both countries. [source] Biochemical, histological and behavioural aspects of visual function during early development of rainbow troutJOURNAL OF FISH BIOLOGY, Issue 4 2004P. S. M. Carvalho Retinal structure and concentration of retinoids involved in phototransduction changed during early development of rainbow trout Oncorhynchus mykiss, correlating with improvements in visual function. A test chamber was used to evaluate the presence of optokinetic or optomotor responses and to assess the functionality of the integrated cellular, physiological and biochemical components of the visual system. The results indicated that in rainbow trout optomotor responses start at 10 days post-hatch, and demonstrated for the first time that increases in acuity, sensitivity to low light as well as in motion detection abilities occur from this stage until exogenous feeding starts. The structure of retinal cells such as cone ellipsoids increased in length as photopic visual acuity improved, and rod densities increased concurrently with improvements in scotopic thresholds (2·2 log10 units). An increase in the concentrations of the chromophore all-trans-retinal correlated with improvements of all behavioural measures of visual function during the same developmental phase. [source] Neuroendocrinological and Molecular Aspects of Insect ReproductionJOURNAL OF NEUROENDOCRINOLOGY, Issue 8 2004G. Simonet Abstract This review summarizes recent advances and novel concepts in the area of insect reproductive neuroendocrinology. The role of ,classic' hormones, such as ecdysteroids and juvenoids, to control reproduction is well documented in a large variety of insect species. In adult gonads, ecdysteroids appear to induce a cascade of transcription factors, many of which also occur during the larval molting response. Recent molecular and functional data have created opportunities to study an additional level of regulation, that of neuropeptides, growth factors and their respective receptors. As a result, many homologs of factors playing a role in vertebrate reproductive physiology have been discovered in insects. This review highlights several neuropeptides controlling the biosynthesis and release of the ,classic' insect hormones, as well as various peptides and biogenic amines that regulate behavioural aspects of the reproduction process. In addition, hormone metabolizing enzymes and second messenger pathways are discussed with respect to their role in reproductive tissues. Finally, we speculate on future prospects for insect neuroendocrinological research as a consequence of the recent ,Genomics Revolution'. [source] Multimodal techniques for smoking cessation: a review of their efficacy and utilisation and clinical practice guidelinesINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 11 2008V. I. Reus Summary Aims:, Nicotine addiction is a complex, chronic condition with physiological and psychological/behavioural aspects that make smoking cessation extremely difficult. This paper reviews current recommendations for smoking cessation and the efficacy of pharmacotherapy and behavioural modification techniques, used either alone or in combination, for smoking cessation. Results:, Abstinence rates for pharmacotherapies range from ,16% to ,30% at 1-year follow-up, with efficacy odds ratios (ORs) compared with placebo of ,1.7 for nicotine replacement therapy (NRT), ,1.9 for bupropion sustained release and ,3.0 for varenicline. Behaviour modification therapies have achieved quit rates of between 8% and 43% for up to 1 year, with ORs in comparison to no treatment of between ,1.2 and ,2.2. No direct comparisons have been made between pharmacotherapy alone and psychological behaviour strategies alone. However, combining physiological approaches with counselling significantly increases the odds of quitting compared with either technique alone. Conclusions:, Applying multimodal techniques for the treatment of nicotine addiction is the recommended approach and has demonstrated the potential to improve rates of permanent abstinence in smokers attempting cessation. While the numbers of patients receiving help and advice regarding smoking cessation is increasing, the multimodal approach appears to be currently underutilised by clinicians and therefore smoking cessation strategies are not being optimised. [source] | |||||||||||||