Search results for "mental stress"
showing 10 items of 65 documents
From foes to friends: Viral infections expand the limits of host phenotypic plasticity
2020
Phenotypic plasticity enables organisms to survive in the face of unpredictable environmental stress. Intimately related to the notion of phenotypic plasticity is the concept of the reaction norm that places phenotypic plasticity in the context of a genotype-specific response to environmental gradients. Whether reaction norms themselves evolve and which factors might affect their shape has been the object of intense debates among evolutionary biologists along the years. Since their discovery, viruses have been considered as pathogens. However, new viromic techniques and a shift in conceptual paradigms are showing that viruses are mostly non-pathogenic ubiquitous entities. Recent studies hav…
Physiological,anatomical and biomass partitioning responses to ozone in the Mediterranean endemic plant Lamottea dianae
2011
Ozone effects on the perennial forb Lamottea dianae were studied in an open-top chamber experiment. Ozone was found to induce reductions in CO 2 assimilation and water use efficiency in the leaves of this species. These reductions were mainly related to a decline in the in vivo CO 2 fixation capacity of Rubisco (V c,max), rather than to stomatal limitations or photoinhibitory damage (F v:F m). In addition to chloroplast degeneration, other observed effects were callose accumulation, formation of pectinaceous wart-like cell wall exudates and phloem alterations. Moreover, ozone exposure significantly reduced root dry biomass. The possible relevance of these adverse effects for Mediterranean f…
Dynamic Animal Populations in Managed Forests: Species Ecological Requirements and Sustainable Harvesting
2015
Forest management has altered forested environments and provoked stress to many natural habitats and biodiversity. The goal of biodiversity management is the long-term persistence of populations in human-modified environments. We demonstrate a spatio-temporal modeling approach to address the relationship between various management objectives and population persistence in the long-term in a commercial forest landscape. We used the flying squirrel (Pteromys volans), the three-toed woodpecker (Picoides tridactylus) and the long-tailed tit (Aegithalos caudatus) as example species. They are all forest species but they have distinctly different habitat requirements. In the model, forest growth, f…
Betreuungsbedarf und subjektiver Unterstützungswunsch von Krebspatientinnen im Längsschnitt – Prädiktoren und Korrelate
2020
The need for psychosocial support and patients' desire for psychosocial support in female cancer patients - predictors and correlates Objectives: The aims of the present study were to determine the need for psychosocial support of cancer patients, the subjective request for support and to examine the relationship between the need for psychosocial counselling, psychological distress and quality of life. Methods: 112 patients (consecutive) answered questionnaires about mental stress (GAD-2 and PHQ-2), quality of life (SF-8) as well as the Hornheide Screening Instrument (HSI) during their hospital stay (T1), two weeks (T2) and three months after their discharge (T3). Results: The need for psyc…
Establishing mussel behaviour as a monitoring tool to measure climatic disturbances
2021
Freshwater mussels (FM) are suitable biological indicators to assess environmental stressors. Behaviour is a good parameter to measure rapid mussel’s responses. In this sense, valvometric method, that exploits the Hall sensor (real-time remote monitoring tool), has been used to measure the behavioural responses of mussels (valve opening amplitude and valve opening-closure frequency). During the last two decades, these methodologies have been used to measure the presence of the pollutants in the waterbodies. However, studies that focus on physical disturbances in the environment related to climate changes are lacking. Since future climatic scenarios in Europe predict an increase in temperatu…
Information dynamics in cardiorespiratory time series during mental stress testing
2014
In this study, we assessed the information dynamics of respiration and heart rate variability during mental stress testing by means of the cross-entropy, a measure of cardiorespiratory coupling, and the self-entropy of the tachogram conditioned to the knowledge of respiration. Although stress is related to a reduction in vagal activity, no difference in cardiorespiratory coupling was found when 5 minutes of rest and stress were compared. The conditional self-entropy, on the other hand, showed significantly higher values during stress, indicating a higher predictability of the tachogram. These results show that entropy analyses of cardiorespiratory data reveal new information that could not …
INVESTIGATION ON THE GENETIC BASIS OF ENVIRONMENTAL STRESS IN FRUIT TREE CROPS
2021
Plant stress can be divided into two major categories: abiotic stress and biotic stress. Abiotic stress happens when plants are exposed to the environment either physically or chemically. There is an emergency in developing crop varieties that are tolerant to abiotic stresses to ensure food security and safety in the coming years. Multiple abiotic stress like drought, heat, frost at flowering and nutrient deficiency can cause an erratic fruiting behavior or following extreme events, the death of the plants. Plants require an optimal level of nutrients and essential minerals for their growth and development that are mainly acquired from soil by their roots. Nutrient deficiency is an environm…
Thermal adaptation and physiological responses to environmental stress in tunicates
2017
Understanding the multifaceted nature of environmental fluctuations is crucial to predicting the physiological adjustments utilised by organisms in resisting or adapting to changes over time. Here we investigate the effects of 2 environmental stressors on tunicates, whose fitness can have important repercussions on the quality of habitat. Specifically, we report respiration rate (RR), clearance rate (CR), and assimilation efficiency (AE) of the ascidian Styela plicata in response to a range of temperatures and varying food availability. Temperature-dependent RR was observed only within a portion of the thermal window of the species. Significant differences in clearance rates were detected a…
On the history of torsional stress concentrations in shafts: From electrical analogies to numerical methods
2014
This article proposes a retrospective on experimental and numerical methods developed throughout the past century to solve the torsion problem in shafts, with particular emphasis on the determination of shear stress concentration factors in discontinuities of typical use in shaft design. This article, in particular, presents the theory and related solutions distinguishing between two classes of geometries: shafts with constant cross section and axisymmetric shafts with variable diameter. Emphasis is given to approaches based on physical analog methods and, in particular, those based on electrical analogies proposed since about 1925. Experimental methods based on structural physical models …
Longitudinal Leisure Activity Profiles and Their Associations with Recovery Experiences and Job Performance
2017
We aimed to identify longitudinal leisure activity profiles among working adults and their links to recovery experiences and job performance. Leisure activities, recovery experiences, and job performance were investigated among 831 employees using survey data collected in spring 2013 (T1) and 2014 (T2). Through latent profile analysis (LPA), four stable longitudinal leisure activity profiles were identified. “Social Sports(wo)men” (46%) engaged in physical and social activities but rarely in creative or cultural activities. “Active Artists” (23%) pursued all leisure activities, particularly creative activities. “Socially & Culturally Inactives” (17%) exercised frequently but seldom engaged …