593 research outputs found
Extracellular Hsp72 concentration relates to a minimum endogenous criteria during acute exercise-heat exposure
Extracellular heat-shock protein 72 (eHsp72) concentration increases during exercise-heat stress when conditions elicit physiological strain. Differences in severity of environmental and exercise stimuli have elicited varied response to stress. The present study aimed to quantify the extent of increased eHsp72 with increased exogenous heat stress, and determine related endogenous markers of strain in an exercise-heat model. Ten males cycled for 90 min at 50% O2peak in three conditions (TEMP, 20°C/63% RH; HOT, 30.2°C/51%RH; VHOT, 40.0°C/37%RH). Plasma was analysed for eHsp72 pre, immediately post and 24-h post each trial utilising a commercially available ELISA. Increased eHsp72 concentration was observed post VHOT trial (+172.4%) (P<0.05), but not TEMP (-1.9%) or HOT (+25.7%) conditions. eHsp72 returned to baseline values within 24hrs in all conditions. Changes were observed in rectal temperature (Trec), rate of Trec increase, area under the curve for Trec of 38.5°C and 39.0°C, duration Trec ≥ 38.5°C and ≥ 39.0°C, and change in muscle temperature, between VHOT, and TEMP and HOT, but not between TEMP and HOT. Each condition also elicited significantly increasing physiological strain, described by sweat rate, heart rate, physiological strain index, rating of perceived exertion and thermal sensation. Stepwise multiple regression reported rate of Trec increase and change in Trec to be predictors of increased eHsp72 concentration. Data suggests eHsp72 concentration increases once systemic temperature and sympathetic activity exceeds a minimum endogenous criteria elicited during VHOT conditions and is likely to be modulated by large, rapid changes in core temperature
A comparative framework: how broadly applicable is a 'rigorous' critical junctures framework?
The paper tests Hogan and Doyle's (2007, 2008) framework for examining critical junctures. This framework sought to incorporate the concept of ideational change in understanding critical junctures. Until its development, frameworks utilized in identifying critical junctures were subjective, seeking only to identify crisis, and subsequent policy changes, arguing that one invariably led to the other, as both occurred around the same time. Hogan and Doyle (2007, 2008) hypothesized ideational change as an intermediating variable in their framework, determining if, and when, a crisis leads to radical policy change. Here we test this framework on cases similar to, but different from, those employed in developing the exemplar. This will enable us determine whether the framework's relegation of ideational change to a condition of crisis holds, or, if ideational change has more importance than is ascribed to it by this framework. This will also enable us determined if the framework itself is robust, and fit for the purposes it was designed to perform — identifying the nature of policy change
Entomological Surveillance of Behavioural Resilience and Resistance in Residual Malaria Vector Populations.
The most potent malaria vectors rely heavily upon human blood so they are vulnerable to attack with insecticide-treated nets (ITNs) and indoor residual spraying (IRS) within houses. Mosquito taxa that can avoid feeding or resting indoors, or by obtaining blood from animals, mediate a growing proportion of the dwindling transmission that persists as ITNs and IRS are scaled up. Increasing frequency of behavioural evasion traits within persisting residual vector systems usually reflect the successful suppression of the most potent and vulnerable vector taxa by IRS or ITNs, rather than their failure. Many of the commonly observed changes in mosquito behavioural patterns following intervention scale-up may well be explained by modified taxonomic composition and expression of phenotypically plastic behavioural preferences, rather than altered innate preferences of individuals or populations. Detailed review of the contemporary evidence base does not yet provide any clear-cut example of true behavioural resistance and is, therefore, consistent with the hypothesis presented. Caution should be exercised before over-interpreting most existing reports of increased frequency of behavioural traits which enable mosquitoes to evade fatal contact with insecticides: this may simply be the result of suppressing the most behaviourally vulnerable of the vector taxa that constituted the original transmission system. Mosquito taxa which have always exhibited such evasive traits may be more accurately described as behaviourally resilient, rather than resistant. Ongoing national or regional entomological monitoring surveys of physiological susceptibility to insecticides should be supplemented with biologically and epidemiologically meaningfully estimates of malaria vector population dynamics and the behavioural phenotypes that determine intervention impact, in order to design, select, evaluate and optimize the implementation of vector control measures
Impacts of climate change on plant diseases – opinions and trends
There has been a remarkable scientific output on the topic of how climate change is likely to affect plant diseases in the coming decades. This review addresses the need for review of this burgeoning literature by summarizing opinions of previous reviews and trends in recent studies on the impacts of climate change on plant health. Sudden Oak Death is used as an introductory case study: Californian forests could become even more susceptible to this emerging plant disease, if spring precipitations will be accompanied by warmer temperatures, although climate shifts may also affect the current synchronicity between host cambium activity and pathogen colonization rate. A summary of observed and predicted climate changes, as well as of direct effects of climate change on pathosystems, is provided. Prediction and management of climate change effects on plant health are complicated by indirect effects and the interactions with global change drivers. Uncertainty in models of plant disease development under climate change calls for a diversity of management strategies, from more participatory approaches to interdisciplinary science. Involvement of stakeholders and scientists from outside plant pathology shows the importance of trade-offs, for example in the land-sharing vs. sparing debate. Further research is needed on climate change and plant health in mountain, boreal, Mediterranean and tropical regions, with multiple climate change factors and scenarios (including our responses to it, e.g. the assisted migration of plants), in relation to endophytes, viruses and mycorrhiza, using long-term and large-scale datasets and considering various plant disease control methods
Lack of Cetuximab induced skin toxicity in a previously irradiated field: case report and review of the literature
<p>Abstract</p> <p>Introduction</p> <p>Mutation, amplification or dysregulation of the EGFR family leads to uncontrolled division and predisposes to cancer. Inhibiting the EGFR represents a form of targeted cancer therapy.</p> <p>Case report</p> <p>We report the case of 79 year old gentlemen with a history of skin cancer involving the left ear who had radiation and surgical excision. He had presented with recurrent lymph node in the left upper neck. We treated him with radiation therapy concurrently with Cetuximab. He developed a skin rash over the face and neck area two weeks after starting Cetuximab, which however spared the previously irradiated area.</p> <p>Conclusion</p> <p>The etiology underlying the sparing of the previously irradiated skin maybe due to either decrease in the population of EGFR expressing cells or decrease in the EGFR expression.</p> <p>We raised the question that "Is it justifiable to use EGFR inhibitors for patients having recurrence in the previously irradiated field?" We may need further research to answer this question which may guide the physicians in choosing appropriate drug in this scenario.</p
Age-related changes in global motion coherence: conflicting haemodynamic and perceptual responses
Our aim was to use both behavioural and neuroimaging data to identify indicators of perceptual decline in motion processing. We employed a global motion coherence task and functional Near Infrared Spectroscopy (fNIRS). Healthy adults (n = 72, 18-85) were recruited into the following groups: young (n = 28, mean age = 28), middle-aged (n = 22, mean age = 50), and older adults (n = 23, mean age = 70). Participants were assessed on their motion coherence thresholds at 3 different speeds using a psychophysical design. As expected, we report age group differences in motion processing as demonstrated by higher motion coherence thresholds in older adults. Crucially, we add correlational data showing that global motion perception declines linearly as a function of age. The associated fNIRS recordings provide a clear physiological correlate of global motion perception. The crux of this study lies in the robust linear correlation between age and haemodynamic response for both measures of oxygenation. We hypothesise that there is an increase in neural recruitment, necessitating an increase in metabolic need and blood flow, which presents as a higher oxygenated haemoglobin response. We report age-related changes in motion perception with poorer behavioural performance (high motion coherence thresholds) associated with an increased haemodynamic response
Aberrant Cortical Activity in Multiple GCaMP6-Expressing Transgenic Mouse Lines
Transgenic mouse lines are invaluable tools for neuroscience but, as with any technique, care must be taken to ensure that the tool itself does not unduly affect the system under study. Here we report aberrant electrical activity, similar to interictal spikes, and accompanying fluorescence events in some genotypes of transgenic mice expressing GCaMP6 genetically encoded calcium sensors. These epileptiform events have been observed particularly, but not exclusively, in mice with Emx1-Cre and Ai93 transgenes, of either sex, across multiple laboratories. The events occur at >0.1 Hz, are very large in amplitude (>1.0 mV local field potentials, >10% df/f widefield imaging signals), and typically cover large regions of cortex. Many properties of neuronal responses and behavior seem normal despite these events, although rare subjects exhibit overt generalized seizures. The underlying mechanisms of this phenomenon remain unclear, but we speculate about possible causes on the basis of diverse observations. We encourage researchers to be aware of these activity patterns while interpreting neuronal recordings from affected mouse lines and when considering which lines to study
Factors involved in nurses' responses to burnout: a grounded theory study
BACKGROUND: Intense and long-standing problems in burn centers in Tehran have led nurses to burnout. This phenomenon has provoked serious responses and has put the nurses, patients and the organization under pressure. The challenge for managers and nurse executives is to understand the factors which would reduce or increase the nurses' responses to burnout and develop delivery systems that promote positive adaptation and facilitate quality care. This study, as a part of more extensive research, aims to explore and describe the nurses' perceptions of the factors affecting their responses to burnout. METHODS: Grounded theory was used as the method. Thirty- eight participants were recruited. Data were generated by unstructured interviews and 21 sessions of participant observations. Constant comparison was used for data analysis. RESULTS: Nurses' and patients' personal characteristics and social support influenced nurses' responses to burnout. Personal characteristics of the nurses and patients, especially when interacting, had a more powerful effect. They altered emotional, attitudinal, behavioral and organizational responses to burnout and determined the kind of caring behavior. Social support had a palliative effect and altered emotional responses and some aspects of attitudinal responses. CONCLUSIONS: The powerful effect of positive personal characteristics and its sensitivity to long standing and intense organizational pressures suggests approaches to executing stress reduction programs and refreshing the nurses' morale by giving more importance to ethical aspects of caring. Moreover, regarding palliative effect of social support and its importance for the nurses' wellbeing, nurse executives are responsible for promoting a work environment that supports nurses and motivates them
Second-opinion stress tele-echocardiography for the Adonhers (Aged donor heart rescue by stress echo) project
<p>Abstract</p> <p>Background</p> <p>To resolve the current shortage of donor hearts, we established the Adonhers protocol. An upward shift of the donor age cut-off limit (from the present 55 to 65 years) is acceptable if a stress echo screening on the candidate donor heart is normal. This study aimed to verify feasibility of a "second opinion" of digitally transferred images of stress echo results to minimize technical variability in selection of aged donor hearts for heart transplant.</p> <p>Methods</p> <p>The informatics infrastructure was created for a core lab reading with a second opinion from the Pisa stress echo lab. To test the system, simulation standard stress echo cineloops were sent digitally from 5 peripheral labs to the central core lab.</p> <p>Starting January 2009, real marginal donor stress echos were sent via internet to the central core echo lab, Pisa, for a second opinion before heart transplant.</p> <p>Results</p> <p>In the simulation protocol, 30 dipyridamole stress echocardiograms were sent from the five peripheral echo labs to the central core lab in Pisa. Both the echo images and reports were correctly uploaded in the web system and sent to the core echo lab; the second opinion evaluation was obtained in all cases (100% feasibility). In the transplant protocol, eight donor cases were sent to the Pisa core lab for the second opinion protocol, and six of them were transplanted in marginal recipients.</p> <p>Conclusions</p> <p>Second-Opinion Stress Tele-Echocardiography can effectively be performed in a network aimed to safely expand the heart donor pool for heart transplant.</p
Comparative LCA technology improvement opportunities for a 1.5 MW wind turbine in the context of an offshore wind farm
Wind energy is playing an increasingly important role in the development of cleaner and more efficient energy technologies leading to projections in reliability and performance of future wind turbine designs. This paper presents life cycle assessment (LCA) results of design variations for a 1.5 MW wind turbine due to the potential for advances in technology to improve the performance of a 1.5 MW wind turbine. Five LCAs have been conducted for design variants of a 1.5 MW wind turbine. The objective is to evaluate potential environmental impacts per kilowatt hour of electricity generated for a 114 MW onshore wind farm. Results for the baseline turbine show that higher contributions to impacts were obtained in the categories Ozone Depletion Potential, Marine Aquatic Eco-toxicity Potential, Human Toxicity Potential and Terrestrial Eco-toxicity Potential compared to Technology Improvement Opportunities (TIOs) 1 to 4. Compared to the baseline turbine, TIO 1 showed increased impact contributions to Abiotic Depletion Potential, Acidification Potential, Eutrophication Potential, Global Warming Potential and Photochemical Ozone Creation Potential, and TIO 2 showed an increase in contributions to Abiotic Depletion Potential, Acidification Potential and Global Warming Potential. Additionally, lower contributions to all the environmental categories were observed for TIO 3 while increased contributions towards Abiotic Depletion Potential and Global Warming Potential were noted for TIO 4. A comparative LCA study of wind turbine design variations for a particular power rating has not been explored in the literature. This study presents new insight into the environmental implications related with projected wind turbine design advancements
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