High Stress Levels (high + stress_level)

Distribution by Scientific Domains

Selected Abstracts

Five years later: children's memory for medical emergencies

Carole Peterson
Children who had been 2,13 years of age at the time of a medical emergency (an injury serious enough to require hospital ER treatment) were re-interviewed about their injury and treatment five years after injury, and three years after a previous interview. The children showed excellent recall of the central components of their injury experience, although their recall of hospital treatment was more incomplete. Thus, both the nature of the event being recalled (the injury versus the hospital treatment) and the centrality of information (central versus peripheral) were important. The recall of 2-year-olds, although not as good as that of children just a year older, did not fit with predictions of infantile amnesia since they recalled a considerable amount about their injury. High stress levels at the time of the target experiences had little effect on the highly memorable injury event, but seemed to facilitate children's recall of central components of the hospital event,the event that they had a harder time remembering. Implications for eyewitness testimony are discussed. Copyright 2001 John Wiley & Sons, Ltd. [source]

The effect of drought stress and temperature on spread of barley yellow dwarf virus (BYDV)

I. N. Smyrnioudis
Summary 1 The effect of drought stress and temperature on the dispersal of wingless aphids Rhopalosiphum padi (L.) and the pattern of spread of BYDV (barley yellow dwarf virus) within wheat plants in controlled environment chambers was quantified. Combinations of three different drought stress levels, unstressed, moderate and high stress level, and three different temperatures, 5 1 C, 10 1 C, and 15 1 C, were investigated. 2 With increased temperature there was an increase in the mean distance of visited plants from the point of release and in the number of plants visited and infected with BYDV. Drought stress had no effect on mean distance moved by aphids at any temperature or on plants infected with virus at 10 C and 5 C. When plants were drought stressed, the numbers of plants visited and infected were greater at 15 C than at 10 C and 5 C. 3 A greater proportion of plants visited by aphids was infected with BYDV when plants were stressed than when not stressed. At 15 C a greater proportion of these plants was infected than at lower temperatures. There was no difference between treatments in the numbers of aphids present at the end of the experiment. 4 It is concluded that drought stress and temperature are of considerable importance in virus spread. [source]

FOAM, a new simple benthic degradative module for the LAMP3D model: an application to a Mediterranean fish farm

Patrizia De Gaetano
Abstract The modelling framework already introduced by Doglioli, Magaldi, Vezzulli and Tucci to predict the potential impact of a marine fish farm is improved following different directions, namely (1) real historic current-metre data are used to force the simulations, (2) settling velocity values specifically targeting Mediterranean fish species are used, and (3) a new benthic degradative module, the Finite Organic Accumulation Module, is added to the modelling framework. The Finite Organic Accumulation Module uses the output of the other functional units of the modelling framework to calculate the organic load on the seabed. The Finite Organic Accumulation Module considers the natural capability of the seafloor in absorbing part of the organic load. Different remineralization rates reflect the sediment stress level according to the work of Findlay and Watling. Organic degradation for both uneaten feed and faeces is evaluated by changing the release modality (continuous and periodical) and by varying the settling velocities. It is found that the maximum impact on the benthic community is observed either for quickly sinking uneaten feed released twice a day, or for less intense near-bottom current conditions. If both the above-mentioned scenarios coexist, a high stress level is established in the sediment. The model also suggests that the use of self-feeders in cages can reduce farm impacts significantly. These results show how the new and more complete modelling framework presented here is able to improve the objectivity in the decision-making processes and how it may be successfully used for planning and monitoring purposes. [source]

Flat boundaries and their effect on sand testing

G. Marketos
Abstract A study of the effect of the use of flat boundaries on the stressing of a sample of an idealized granular material with no applied shear is presented. Discrete element method (DEM) data of 1D compression were analysed and the local strain field inside the sample was investigated as the sample was stressed. A best-fit strain was seen to best describe the material behaviour free from boundary effects. The individual particle displacements were probed, providing insight into the behaviour of particles adjacent to the boundaries. In addition, the porosity and force distribution inside the sample were observed, allowing for estimates of the width of a boundary region to be made. This region, non-representative of far-field material behaviour, will affect the behaviour of a granular sample in DEM or laboratory tests, with local porosity differences leading to a change in the transport properties of the sample, and force distribution changes leading to a bias in the location of grain cracking or crushing events for sufficiently high stress levels. Nevertheless, the largest effect of the boundary region was a severe underestimation of the stiffness of a granular material. Copyright 2009 John Wiley & Sons, Ltd. [source]

Effect of the water/cement ratio on concrete behavior under extreme loading

Xuan Hong Vu
Abstract This study focuses on identifying concrete behavior under severe triaxial loadings (near field detonation or ballistic impacts). In order to reproduce high stress levels with well-controlled loading paths, static tests have been carried out on concrete samples by mean of a very high-capacity triaxial press (stress levels on the order of 1,GPa). It is a longstanding fact that the water/cement ratio (W/C), upon entering the concrete composition, is a major parameter affecting the porosity and strength of the cement matrix of hardened concrete. The objective of this article is to quantify the effect of this ratio on concrete behavior under conditions of high confinement. From the composition of a reference ,ordinary' concrete (i.e. W/C=0.6), two other concretes have been produced with W/C ratios equal to 0.4 and 0.8, respectively. This article presents experimental results and their analysis regarding the effect of water/cement ratio (W/C) on concrete behavior under high confinement. It shows that when placed under high confinement, concrete behaves like a granular stacking composed of concrete without any influence from the level of cement matrix strength. Copyright 2009 John Wiley & Sons, Ltd. [source]

A controlled rapid-sequence induction technique for infants may reduce unsafe actions and stress

Background: Classic rapid-sequence induction of anaesthesia (RSI-classic) in infants and small children presents a time-critical procedure, regularly associated with hypoxia. This results in high stress levels for the provider and may trigger unsafe actions. Hence, a controlled induction technique (RSI-controlled) that involves gentle mask ventilation until full non-depolarizing muscular blockade has become increasingly popular. Clinical observation suggests that RSI-controlled may reduce the adverse effects noted above. We aimed to evaluate both techniques with respect to unsafe actions and stress. Methods: In this controlled, randomized simulator-based study, 30 male trainees and specialists in anaesthesiology performed a simulated anaesthesia induction in a 4-week-old infant with pyloric stenosis. Two different RSI techniques, classic and controlled, were applied to 15 candidates each. We recorded the incidence of hypoxaemia, forced mask ventilation, and intubation difficulties. In addition, we measured individual stress levels by ergospirometry, salivary cortisol, and ,-amylase, as well as a post-trial questionnaire. Results: Hypoxaemia always occurred in RSI-classic but not in RSI-controlled, repeatedly resulting in unsafe actions. Subjective stress perception and some objective stress levels were lower in the volunteers performing RSI-controlled. Conclusions: Our data suggest that RSI-controlled, as compared with RSI-classic, leads to fewer unsafe actions and may reduce individual stress levels. [source]

Staff in services for people with intellectual disabilities: the impact of stress on attributions of challenging behaviour

D. Rose
Abstract Background There is a lack of a conceptual framework as to how stress and attribution variables interact and influence staff behaviour in response to challenging behaviour. To address this, a model is tested examining the impact of stress on attributions of challenging behaviour within Weiner's model of helping. Method A total of 107 staff working in community homes for people with intellectual disabilities completed a self-report questionnaire that measured stress, burnout, attributions, emotions, optimism and helping behaviour in response to challenging behaviour. Results Partial support was found for the role of attributions and emotions. However, although staff reported high stress levels and moderate burnout, this did not appear to relate to their reporting of thoughts and feelings regarding challenging behaviour predicted by Weiner's helping model. It was not possible to fully test the helping model, as the ,help' variable was not normally distributed. Conclusions There was little evidence to suggest that stress has a primary role in determining staff responses when examined within Weiner's model of helping. Limited support in general was offered for Weiner's helping model. Potential conceptual difficulties and clinical implications are explored and alternative models for future research are discussed. [source]