Search results for "mental stress"
showing 10 items of 65 documents
Mechanism of brittle fracture in a ductile 316 alloy during stress corrosion
1990
Abstract The ductile f.c.c. 316 alloy is shown to exhibit brittle transgranular (and intergranular) stress corrosion cracking in a 153°C MgCl2 solution at free corrosion potential. Tests on smooth and pre-cracked specimens are performed to identify the mechanisms of fracture. Transgranular cracking is related to both a discontinuous microcleavage mainly on {100} planes and a microshearing on {111} planes. A new physical modelization is proposed to explain the brittle transgranular cracking. It is based on the influence of the localized anodic dissolution on the enhancement of the plasticity at the crack tip. The formation of dislocation pile-ups and the conditions of restricted slip induce …
Multilevel assessment of mental stress via network physiology paradigm using consumer wearable devices
2019
Mental stress is a physiological condition that has a strong negative impact on the quality of life, affecting both the physical and the mental health. For such a reason, accurate measurements of stress level can be helpful to provide mechanisms for prevention and treatment. This paper proposes a procedure for the classification of different mental stress levels by using physiological signals provided by low invasive wearable devices. 17 healthy volunteers participated in this study. Three different mental states were elicited in them: a resting condition, a stressful cognitive state, and a sustained attention task. The acquired physiological signals were: a one lead electrocardiogram (ECG)…
Croissance et miniaturisation de quelques Hildoceras (Cephalopoda) en liaison avec des environnements contraignants de la Téthys toarcienne
1993
Resume La zone a Bifrons (Toarcien moyen) est une perode bien etudiee du point de vue stratigraphique tant en Europe occidentale (marge NW de la Tethys et plates-formes adjacentes) qu'en Italie et Afrique du Nord (marge sud de la Tethys). Dans ces regions, la succession zonale est basee sur l'evolution des Hildoceras. Cependant, on remarque que certains d'entre eux, quelle que soit leur place dans la lignee, presentent des particularites ornementales et dimensionnelles, manifestement liees au gisement dont ils sont, issus et aux conditions qui y regnaient. C'est particulierement le cas des sites d'Italie centrale et d'Algerie situes dans les fonds des ombilics de sedimentation crees par la …
The effects of treated effluents on the intensity of papillomatosis and HSP70 expression in roach.
2008
Epidermal papillomatosis in fish has been proposed as an indicator of environmental stress but experimental evidence of connection between contaminants and papillomatosis in fish is scarce. We studied changes in the intensity of epidermal papillomatosis and the expression of heat shock protein 70 (HSP70) in roach, Rutilus rutilus, exposed to treated pulp mill and municipal effluents. In male roach, the increase in papillomatosis intensity was higher in fish exposed to 15% than in fish exposed to 1.5% concentration of municipal effluent. No differences were observed in papillomatosis development in females, or in HSP70 expression. In all the experiments conducted, the increasing effect of ef…
Changes in land use and physiological transitions of a Juniperus thurifera forest: from decline to recovery
2015
All Rights Reserved. Forest decline is frequently associated with infection; however, infections habitually affect trees that have been previously debilitated by environmental stress. Nevertheless, the causes and physiology of noninfectious forest decline are not well known. Some Juniperus thurifera L. forests presented severe (noninfectious) declines, with defoliations over 50%. The goal of this study was to determine the causes and characterize the physiology of this noninfectious decline, and we hypothesized that it could be related to environmental stress from increasing interspecific competition resulting from land abandonment. We randomly assigned60 trees to either a control group or …
Bevölkerungsbezogene psychische Gesundheit als Schlüsselfaktor im Umgang mit COVID-19
2020
Zusammenfassung Ziel Das Ziel des Beitrages besteht darin, auf die bedeutsame Rolle der Prävention und Reduktion der psychischen Belastungen in der Allgemeinbevölkerung und in sensiblen Gruppen im Rahmen der Coronavirus-Krankheit-2019 (COVID-19) -Pandemie hinzuweisen. Methodik Der vorliegende Beitrag umfasst die Analyse und Bewertung von Studien und Empfehlungen von Organisationen wie der Weltgesundheitsorganisation (WHO), die die bevölkerungsbezogenen psychischen Auswirkungen von Epi-/Pandemien und deren Einfluss auf den weiteren Verlauf untersucht haben. Ergebnisse Angstbedingte Verhaltensweisen können sich negativ auf den Verlauf von Epidemien auswirken. Im Rahmen vergangener Ausbrüche v…
Neuroplasticity and environment: A pharmacotherapeutic approach toward preclinical and clinical understanding
2021
International audience; Emerging research in the field of behavioral neuroscience has demonstrated the fundamental role of the cerebral organization. For brain development, various important functions are required for instance synaptic plasticity and neurogenesis. This property is described in terms of neuroplasticity. Neuroplasticity denotes the extraordinary ability of the brain for the recognition of its structure and function after an experience with some external stimuli and involves in the various behavioral processes of the brain such as cognitive functions. It has multiple factors that can range from gene alteration to environmental factors. Environmental factors exert both negative…
Sea urchin coelomocytes as a novel cellular biosensor of environmental stress: a field study in the Tremiti Island Marine Protected Area, Southern Ad…
2007
The aim of the present study was to investigate on the suitability of the sea urchin as a sentinel organism for the assessment of the macro-zoobenthos health state in bio-monitoring programmes. A field study was carried out during two oceanographic campaigns using immuno-competent cells, the coelomocytes, from sea urchins living in a marine protected area. In particular, coelomocytes subpopulations ratio and heat shock protein 70 (HSC70) levels were measured in specimens of Paracentrotus lividus (Lamark, 1816) collected in two sampling sites, namely Pianosa and Caprara Islands, both belonging to the Tremiti Island Marine Protected Area (MPA) in the Southern Adriatic Sea, Italy. By density g…
A New Procedure for the Evaluation of Non-Uniform Residual Stresses by the Hole Drilling Method Based on the Newton-Raphson Technique
2010
The hole drilling method is one of the most used semi-destructive techniques for the analysis of residual stresses in mechanical components. The non-uniform stresses are evaluated by solving an integral equation in which the strains relieved by drilling a hole are introduced. In this paper a new calculation procedure, based on the Newton-Raphson method for the determination of zeroes of functions, is presented. This technique allows the user to introduce complex and effective forms of stress functions for the solution of the problem. All the relationships needed for the evaluation of the stresses are obtained in explicit form, eliminating the need to use additional mathematical tools. The t…
Effects of heat and cold on health, with special reference to Finnish sauna bathing.
2018
Environmental stress such as extremely warm or cold temperature is often considered a challenge to human health and body homeostasis. However, the human body can adapt relatively well to heat and cold environments, and recent studies have also elucidated that particularly heat stress might be even highly beneficial for human health. Consequently, the aim of the present brief review is first to discuss general cardiovascular and other responses to acute heat stress, followed by a review of beneficial effects of Finnish sauna bathing on general and cardiovascular health and mortality as well as dementia and Alzheimer's disease risk. Plausible mechanisms included are improved endothelial and …