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Stress Physiology (stress + physiology)
Selected AbstractsSleep arrangements and night waking at 6 and 12 months in relation to infants' stress-induced cortisol responsesINFANT AND CHILD DEVELOPMENT, Issue 6 2009Rachel Lucas-Thompson Abstract The objective of this short-term longitudinal study was to examine the concurrent and prospective associations of infants' sleep arrangements and night waking with cortisol responses to an inoculation at 6 and 12 months, controlling for several key covariates. To our knowledge, this was the first study to concurrently and prospectively link proximity in sleep arrangements and night waking to physiological stress reactivity. A sample of 92 mother,infant dyads participated in the study when the infants were 6 and 12 months of age, although sample sizes were reduced for some analyses. Both proximal cosleeping arrangements and more frequent night wakings' were associated concurrently with an increased cortisol response to inoculations at both ages. Night waking at 6 months also was associated with a slightly increased cortisol response to inoculation at 12 months. Results aimed at exploring the direction of influence suggested that cosleeping and night waking may influence infant stress physiology rather than the reverse. Adaptive and maladaptive implications of infants' nocturnal experiences and greater stress-induced cortisol responses are discussed. Copyright © 2009 John Wiley & Sons, Ltd. [source] The physiology of predator stress in free-ranging preyJOURNAL OF ANIMAL ECOLOGY, Issue 6 2009Evan L. Preisser M.J. Sheriff, C.J. Krebs & R. Boonstra (2009) The sensitive hare: sublethal effects of predator stress on reproduction in snowshoe hares. Journal of Animal Ecology, 78, 1249,1258. Ecologists have only begun to understand the physiological mechanisms underlying individual- and population-level responses of prey- to predator-related stress. Sheriff, Krebs and Boonstra advance this field by providing evidence that predator-induced increases in glucorticoid concentrations in wild female snowshoe hares (Lepus americanus) impact both litter size and offspring condition. They hypothesize that the glucocorticoid-mediated effects on reproduction provides an adaptive benefit: mothers ,programming' their offspring to be timid and risk-averse in high-risk environments should increase their survival probability. This research illuminates the connection between stress physiology and population-level changes and demonstrates the surprisingly far-reaching impact of predation risk. [source] Lack of glucose and hsp70 responses in haddock Melanogrammus aeglefinus (L.) subjected to handling and heat shockJOURNAL OF FISH BIOLOGY, Issue 1 2008L. O. B. Afonso Juvenile haddock Melanogrammus aeglefinus (c. 39 g) were exposed to either a handling stressor (1 min out of water) or heat shock (increase from 10 to 15° C for 1 h), and plasma cortisol, plasma glucose and gill hsp70 levels were determined before, and at 1, 3, 6, 12, 24 and 48 h post-stress. The pattern of cortisol increase was similar following both stressors, with levels increasing by 25-fold at 1 h post-stress, but returning to pre-stress levels (2,5 ng ml,1) by 3 h. In contrast, neither handling nor heat shock caused an increase in plasma glucose levels. Although gill hsp70 was detected, presumably constitutive levels, in both control and heat shocked groups, there were not significant changes in gill hsp70 levels after exposure to heat shock. The lack of glucose and hsp70 responses to these typical stressors is consistent with previous studies on Atlantic cod Gadus morhua, and suggests that the stress physiology of Gadidae differs from the ,typical' teleost. [source] Epigenetics and the embodiment of race: Developmental origins of US racial disparities in cardiovascular healthAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 1 2009Christopher W. Kuzawa The relative contribution of genetic and environmental influences to the US black-white disparity in cardiovascular disease (CVD) is hotly debated within the public health, anthropology, and medical communities. In this article, we review evidence for developmental and epigenetic pathways linking early life environments with CVD, and critically evaluate their possible role in the origins of these racial health disparities. African Americans not only suffer from a disproportionate burden of CVD relative to whites, but also have higher rates of the perinatal health disparities now known to be the antecedents of these conditions. There is extensive evidence for a social origin to prematurity and low birth weight in African Americans, reflecting pathways such as the effects of discrimination on maternal stress physiology. In light of the inverse relationship between birth weight and adult CVD, there is now a strong rationale to consider developmental and epigenetic mechanisms as links between early life environmental factors like maternal stress during pregnancy and adult race-based health disparities in diseases like hypertension, diabetes, stroke, and coronary heart disease. The model outlined here builds upon social constructivist perspectives to highlight an important set of mechanisms by which social influences can become embodied, having durable and even transgenerational influences on the most pressing US health disparities. We conclude that environmentally responsive phenotypic plasticity, in combination with the better-studied acute and chronic effects of social-environmental exposures, provides a more parsimonious explanation than genetics for the persistence of CVD disparities between members of socially imposed racial categories. Am. J. Hum. Biol., 2009. © 2008 Wiley-Liss, Inc. [source] Some critical issues in environmental physiology of grapevines: future challenges and current limitationsAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 2010H.R. SCHULTZ Abstract The rapidly increasing world population and the scarcity of suitable land for agricultural food production together with a changing climate will ultimately put pressure on grape-producing areas for the use of land and the input of resources. For most grape-producing areas, the predicted developments in climate will be identical to becoming more marginal for quality production and/or to be forced to improve resource management. This will have a pronounced impact on grapevine physiology, biochemistry and ultimately production methods. Research in the entire area of stress physiology, from the gene to the whole plant and vineyard level (including soils) will need to be expanded to aid in the mitigation of arising problems. In this review, we elaborate on some key issues in environmental stress physiology such as efficient water use to illustrate some of the challenges, current limitations and future possibilities of certain experimental techniques and/or data interpretations. Key regulatory mechanisms in the control of stomatal conductance are treated in some detail and several future research directions are outlined. Diverse physiological aspects such as the functional role of aquaporins, the importance of mesophyll conductance in leaf physiology, night-time water use and respiration under environmental constraints are discussed. New developments for improved resource management (mainly water) such as the use of remote sensing and thermal imagery technologies are also reviewed. Specific cases where our experimental systems are limited or where research has been largely discontinued (i.e. stomatal patchiness) are treated and some promising new developments, such as the use of coupled structural functional models to assess for environmental stress effects on a whole-plant or canopy level are outlined. Finally, the status quo and research challenges around the ,CO2 -problem' are presented, an area which is highly significant for the study of ,the future' of the grape and wine industry, but where substantial financial commitment is needed. [source] | ||||||||||