Search results for " STRESS"
showing 10 items of 3936 documents
P-T path development derived from shearband boudin microstructure
2016
This work focuses on the development of a regional P-T-path from the Malpica-Lamego Ductile Shear Zone, NW Portugal, based on the microstructures of shearband boudins evolved during progressive simple shear. The combination of microstructural analysis, fluid inclusion studies, crystallographic pre- ffered orientation and fractal geometry analyses, allows to link several stages in the internal evolution of the boudin to regional P-T conditions. The boudinage process is initiated under differential stress after the original layer achieved sufficient viscosity contrast relative to the surrounding matrix. Two main transformations occur simultaneously: i) change in the external shape with contin…
Professional vision of Grade 1 teachers experiencing different levels of work-related stress
2022
This study explored teachers' professional vision by examining how teachers experiencing low, moderate and high work-related stress reason their eye-tracking recordings in terms of description, explanation and prediction. A qualitative analysis of retrospective think-aloud interviews with 24 Grade 1 teachers showed that teachers predominantly used description in their reasoning, while explanation and prediction were less frequent. The description mainly focused on teacher information/elaboration and classroom management/behaviour. Teachers with moderate stress utilised self-reflection most frequently, whereas teachers with high stress utilised it the least. The results suggest that the leve…
Does Positive Thinking Help during Difficult Pandemic Times? The Role of Positive Orientation in the Relationship between Fear of COVID-19 and Percei…
2023
The COVID-19 pandemic has become a huge challenge for the modern world. How people perceive themselves and their coping abilities is important for their mental health and well-being. One of the traits that may be important in effectively coping with difficulties is positive orientation: a stable cognitive disposition that is the opposite of depression and is associated with a positive perception of oneself, one’s life, events, and the future. This study aimed to verify the role of positive orientation in the relationship between fear of COVID-19 and perceived stress. A sample of 907 Polish people took part in this study. FOC-6, P Scale, and PSS-10 questionnaires were used in the presented c…
Effects of tobacco cigarettes, e-cigarettes, and waterpipe smoking on endothelial function and clinical outcomes
2020
Abstract Tobacco smoking is a leading cause of non-communicable disease globally and is a major risk factor for cardiovascular disease (CVD) and lung disease. Importantly, recent data by the World Health Organizations (WHO) indicate that in the last two decades global tobacco use has significantly dropped, which was largely driven by decreased numbers of female smokers. Despite such advances, the use of e-cigarettes and waterpipes (shisha, hookah, narghile) is an emerging trend, especially among younger generations. There is growing body of evidence that e-cigarettes are not a harm-free alternative to tobacco cigarettes and there is considerable debate as to whether e-cigarettes are saving …
Mitochondrial compartment: a possible target of cadmium effects on breast epithelial cells.
2009
Cadmium–breast epithelial cell interactions were studied by analyzing some mitochondria-related aspects of stress response. We treated immortalized non-tumor breast cells with 5 or 50 μM CdCl2 for 24 or 96 h demonstrating that the exposure did not cause a significant mitochondrial proliferation, while it induced a significant increase in the respiratory activity and mitochondrial polarization. In addition, we found that hsp60 was up-regulated while hsp70 and COXII and COXIV were down-regulated. The mRNA for hsp70 remained constant and only the inducible form of the 70-kDa heat shock protein was over expressed. The mRNAs for COXII and COXIV remained constant after 24 h and increased after lo…
Prevalence of burnout in a sample of Brazilian teachers
2011
Background and Objectives: Burnout is a psychological response to chronic work-related stress of an interpersonal and emotional nature. Brazilian law have already contemplated burnout syndrome as a mental and behavioural disorder related to work. The aim of this study was to identify the prevalence of burnout in a sample of Brazilian teachers. Methods: The sample was composed of 714 teachers from 8 schools in Porto Alegre and its metropolitan area (Brazil). The levels of burnout were evaluated by the Spanish Burnout Inventory, educational version (SBI-Ed). In addition, Psychosomatic disorders were estimated by the UNIPSICO subscale. Results: The percentage of participants who indicated high…
Numerical modelling of fatigue crack initiation of martensitic steel
2010
Numerical simulation of micro-crack initiation that is based on Tanaka-Mura micro-crack nucleation model is presented. Three improvements were added to this model. Firstly, multiple slip bands where micro-cracks may occur are used in each grain. Second improvement deals with micro-crack coalescence by extending existing micro-cracks along grain boundaries and connecting them into a macro-crack. The third improvement handles segmented micro-crack generation, where a micro-crack is not nucleated in one step like in Tanaka-Mura model, but is instead generated in multiple steps. Numerical simulation of crack-initiation was performed with ABAQUS, using a plug-in that was written specially for ha…
Structuring of polymer blends in simple shear flow
1990
A simplified model for the formation of steady state structure of discrete domains in polymer blends is established for simple shear flow. It is assumed that the domain size distribution, which results from an equilibrium between breakup processes and coalescence processes, may be divided in small and stable spherical domains and large and unstable ellipsoidal domains. Based on simplified rate balances and an expression for domain deformation rate the volume fraction of large domains and the large and small semiaxes of the ellipsoids are expressed as functions of volume fraction and shear rate/shear stress. The ability of the model to simulate actual behaviour is tested against quantitative…
The Interaction Between Physical and Psychosocial Stressors
2020
Do physical and psychosocial stressors interact to increase stress in ways not explainable by the stressors alone? A preliminary study compared participants’ stress response while subjected to a physical stressor (reduced or full physical load) and a predetermined social stressor (confronted by calm or aggressive behavior). Salivary cortisol samples measured endocrine stress. Heart rate variability (HRV) and electrodermal activity (EDA) measured autonomic stress. Perceived stress was measured via discomfort and stress state surveys. Participants with a heavier load reported increased distress and discomfort. Encountering an aggressive individual increased endocrine stress, distress levels, …
Mechanisms of Shared Vulnerability to Post-traumatic Stress Disorder and Substance Use Disorders
2020
Psychoactive substance use is a nearly universal human behavior, but a significant minority of people who use addictive substances will go on to develop an addictive disorder. Similarly, though ~90% of people experience traumatic events in their lifetime, only ~10% ever develop post-traumatic stress disorder (PTSD). Substance use disorders (SUD) and PTSD are highly comorbid, occurring in the same individual far more often than would be predicted by chance given the respective prevalence of each disorder. Some possible reasons that have been proposed for the relationship between PTSD and SUD are self-medication of anxiety with drugs or alcohol, increased exposure to traumatic events due to a…