1,717 research outputs found

    Rapid evolution of leaf physiology in an introduced beach daisy

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    Photosynthesis is a key biological process. However, we know little about whether plants change their photosynthetic strategy when introduced to a new range. We located the most likely source population for the South African beach daisy Arctotheca populifolia introduced to Australia in the 1930s, and ran a common-garden experiment measuring 10 physiological and morphological leaf traits associated with photosynthesis. Based on predictions from theory, and higher rainfall in the introduced range, we hypothesized that introduced plants would have a (i) higher photosynthetic rate, (ii) lower water-use efficiency (WUE) and (iii) higher nitrogen-use efficiency. However, we found that introduced A. populifolia had a lower photosynthetic rate, higher WUE and lower nitrogen-use efficiency than did plants from Arniston, South Africa. Subsequent site visits suggested that plants in Arniston may be able to access moisture on a rocky shelf, while introduced plants grow on sandy beaches where water can quickly dissipate. Our unexpected findings highlight that: (1) it is important to compare introduced species to their source population for an accurate assessment of evolutionary change; (2) rainfall is not always a suitable proxy for water availability and (3) introduced species often undergo evolutionary changes, but without detailed ecological information we may not be able to accurately predict the direction of these changes

    COP21 climate negotiators' responses to climate model forecasts

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    Policymakers involved in climate change negotiations are key users of climate science. It is therefore vital to understand how to communicate scientific information most effectively to this group. We tested how a unique sample of policymakers and negotiators at the Paris COP21 conference update their beliefs on year 2100 global mean temperature increases in response to a statistical summary of climate models' forecasts. We randomized the way information was provided across participants using three different formats similar to those used in Intergovernmental Panel on Climate Change reports. In spite of having received all available relevant scientific information, policymakers adopted such information very conservatively, assigning it less weight than their own prior beliefs. However, providing individual model estimates in addition to the statistical range was more effective in mitigating such inertia. The experiment was repeated with a population of European MBA students who, despite starting from similar priors, reported conditional probabilities closer to the provided models' forecasts than policymakers. There was also no effect of presentation format in the MBA sample. These results highlight the importance of testing visualization tools directly on the population of interest

    Criminal and Noncriminal Psychopathy: The Devil is in the Detail

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    Brooks, NS ORCiD: 0000-0003-1784-099XPsychopathy is prevalent and problematic in criminal populations, but is also found to be present in noncriminal populations. In 1992, Robert Hare declared that psychopaths may also “be found in the boardroom”, which has since been followed by an interest in the issue of noncriminal, or even successful, psychopathy. In this chapter, the paradox of criminal and noncriminal psychopathy is discussed with specific attention given to the similarities and differences that account for psychopathic personality across contexts. That psychopathy is a condition typified by a constellation of traits and behaviours requires wider research across diverse populations, and thus the streams of research related to criminal and noncriminal psychopathy are presented and the implications of these contrasting streams are explored

    Prehospital intravenous access and fluid resuscitation in severe sepsis: An observational cohort study

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    Introduction: Prompt treatment of severe sepsis in the Emergency Department reduces deaths, but the role of prehospital fluid resuscitation is unknown. We sought to determine the risk-adjusted association between prehospital fluid administration and hospital mortality among emergency medical services (EMS) patients admitted with severe sepsis. Methods: We performed a prospective, observational study of patients hospitalized with severe sepsis on admission among 45,394 adult EMS encounters taken to 15 hospitals from 11/2009 to 12/2010 by a two-tier EMS system in King County, Washington. The region mandated recording of prehospital intravenous catheter and fluid administration in prehospital records, along with detailed demographic, incident, physiologic, and hospital adjustment variables. We determined the effect of prehospital intravenous catheter or fluid versus no catheter or fluid on all-cause mortality using multivariable logistic regression. Results: Of all encounters, 1,350 met criteria for severe sepsis on admission, of whom 205 (15%) died by hospital discharge, 312 (23%) received prehospital intravenous fluid, 90 (7%) received a prehospital catheter alone and 948 (70%) did not receive catheter or fluid. EMS administered a median prehospital fluid volume of 500 mL (interquartile range (IQR): 200, 1000 mL). In adjusted models, the administration of any prehospital fluid was associated with reduced hospital mortality (Odds ratio =0.46; 95% Confidence interval: 0.23, 0.88; P =0.02) compared to no prehospital fluid. The odds of hospital mortality were also lower among severe sepsis patients treated with prehospital intravenous catheter alone (Odds ratio =0.3; 95% Confidence interval: 0.17 to 0.57; P <0.01). Conclusions: In a population-based study, the administration of prehospital fluid and placement of intravenous access were associated with decreased odds of hospital mortality compared with no prehospital catheter or fluid

    Anesthesia of Epinephelus marginatus with essential oil of Aloysia polystachya: an approach on blood parameters

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    This study investigated the anesthetic potential of the essential oil (EO) of Aloysia polystachya in juveniles of dusky grouper (Epinephelus marginatus). Fish were exposed to different concentrations of EO of A. polystachya to evaluate time of induction and recovery from anesthesia. In the second experiment, fish were divided into four groups: control, ethanol and 50 or 300 mu L L-1 EO of A. polystachya, and each group was submitted to induction for 3.5 min and recovery for 5 or 10 min. The blood gases and glucose levels showed alterations as a function of the recovery times, but Na+ and K+ levels did not show any alteration. In conclusion, the EO from leaves of A. polystachya is an effective anesthetic for dusky grouper, because anesthesia was reached within the recommended time at EO concentrations of 300 and 400 mu L L-1. However, most evaluated blood parameters showed compensatory responses due to EO exposure.Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul/Programa de Apoio a Nucleos de Excelencia (FAPERGS/PRONEX) [10/0016-8]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [470964/2009-0]; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior, Brazil (CAPES)info:eu-repo/semantics/publishedVersio

    Decreased respiratory system compliance on the sixth day of mechanical ventilation is a predictor of death in patients with established acute lung injury

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    <p>Abstract</p> <p>Background</p> <p>Multiple studies have identified single variables or composite scores that help risk stratify patients at the time of acute lung injury (ALI) diagnosis. However, few studies have addressed the important question of how changes in pulmonary physiologic variables might predict mortality in patients during the subacute or chronic phases of ALI. We studied pulmonary physiologic variables, including respiratory system compliance, P/F ratio and oxygenation index, in a cohort of patients with ALI who survived more than 6 days of mechanical ventilation to see if changes in these variables were predictive of death and whether they are informative about the pathophysiology of subacute ALI.</p> <p>Methods</p> <p>Ninety-three patients with ALI who were mechanically ventilated for more than 6 days were enrolled in this prospective cohort study. Patients were enrolled at two medical centers in the US, a county hospital and a large academic center. Bivariate analyses were used to identify pulmonary physiologic predictors of death during the first 6 days of mechanical ventilation. Predictors on day 1, day 6 and the changes between day 1 and day 6 were compared in a multivariate logistic regression model.</p> <p>Results</p> <p>The overall mortality was 35%. In multivariate analysis, the PaO<sub>2</sub>/FiO<sub>2 </sub>(OR 2.09, p < 0.04) and respiratory system compliance (OR 3.61, p < 0.01) were predictive of death on the 6<sup>th </sup>day of acute lung injury. In addition, a decrease in respiratory system compliance between days 1 and days 6 (OR 2.14, p < 0.01) was independently associated with mortality.</p> <p>Conclusions</p> <p>A low respiratory system compliance on day 6 or a decrease in the respiratory system compliance between the 1<sup>st </sup>and 6<sup>th </sup>day of mechanical ventilation were associated with increased mortality in multivariate analysis of this cohort of patients with ALI. We suggest that decreased respiratory system compliance may identify a subset of patients who have persistent pulmonary edema, atelectasis or the fibroproliferative sequelae of ALI and thus are less likely to survive their hospitalization.</p

    Performance of non-uniform tidal turbine arrays in uniform flow

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    Theoretical models suggest that in order to maximise their collective power out put, tidal turbines should be arranged in a single cross-stream row and optimally spaced to exploit local blockage effects. However, because it is assumed that the turbines within these arrays are identical, such models do not consider the possibility of enhanced power production through the exploitation of spanwise variations in local blockage and resistance. In this paper, we use depth-averaged numerical simulations to investigate whether the performance of a tidal turbine array can be further enhanced by varying solely the local blockage, solely the local resistance, or both local blockage and resistance together, across the array width. Our results suggest that for an initially uniform flow field, the optimal tidal turbine array is also uniform, that is to say that it comprises turbines of equal size, spacing, and resistance. This finding is encouraging because it is more cost-effective and much simpler to design each turbine to be the same and to operate in the same way. Together with earlier findings, these results also suggest a more general, and perhaps unsurprising, conclusion that tidal turbine arrays perform best when designed to match site-specific natural flow conditions

    Psychopathic leadership a case study of a corporate psychopath CEO

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    This longitudinal case study reports on a charity in the UK which gained a new CEO who was reported by two middle managers who worked in the charity, to embody (respectively) all or most of the ten characteristics within a measure of corporate psychopathy. The leadership of this CEO with a high corporate psychopathy score was reported to be so poor that the organisation was described as being one without leadership and as a lost organisation with no direction. This paper outlines the resultant characteristics of the ensuing aimlessness and lack of drive of the organisation involved. Comparisons are made to a previous CEO in the same organisation, who was reportedly an authentic, effective and transformational leader. Outcomes under the CEO with a high corporate psychopathy score were related to bullying, staff withdrawal and turnover as effective employees stayed away from and/or left the organisation. Outcomes also included a marked organisational decline in terms of revenue, employee commitment, creativity and organisational innovativeness. The paper makes a contribution to both leadership and to corporate psychopathy research as it appears to be the first reported study of a CEO with a high corporate psychopathy score

    Biomarkers of acute lung injury: worth their salt?

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    The validation of biomarkers has become a key goal of translational biomedical research. The purpose of this article is to discuss the role of biomarkers in the management of acute lung injury (ALI) and related research. Biomarkers should be sensitive and specific indicators of clinically important processes and should change in a relevant timeframe to affect recruitment to trials or clinical management. We do not believe that they necessarily need to reflect pathogenic processes. We critically examined current strategies used to identify biomarkers and which, owing to expedience, have been dominated by reanalysis of blood derived markers from large multicenter Phase 3 studies. Combining new and existing validated biomarkers with physiological and other data may add predictive power and facilitate the development of important aids to research and therapy
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