70 research outputs found

    The development of an intervention programme to reduce whole-body vibration exposure at work induced by a change in behaviour: a study protocol

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    <p>Abstract</p> <p>Background</p> <p>Whole body vibration (WBV) exposure at work is common and studies found evidence that this exposure might cause low back pain (LBP). A recent review concluded there is a lack of evidence of effective strategies to reduce WBV exposure. Most research in this field is focussed on the technical implications, although changing behaviour towards WBV exposure might be promising as well. Therefore, we developed an intervention programme to reduce WBV exposure in a population of drivers with the emphasis on a change in behaviour of driver and employer. The hypothesis is that an effective reduction in WBV exposure, in time, will lead to a reduction in LBP as WBV exposure is a proxy for an increased risk of LBP.</p> <p>Methods/Design</p> <p>The intervention programme was developed specifically for the drivers of vibrating vehicles and their employers. The intervention programme will be based on the most important determinants of WBV exposure as track conditions, driving speed, quality of the seat, etc. By increasing knowledge and skills towards changing these determinants, the attitude, social influence and self-efficacy (ASE) of both drivers and employers will be affected having an effect on the level of exposure. We used the well-known ASE model to develop an intervention programme aiming at a change or the intention to change behaviour towards WBV exposure. The developed programme consists of: individual health surveillance, an information brochure, an informative presentation and a report of the performed field measurements.</p> <p>Discussion</p> <p>The study protocol described is advantageous as the intervention program actively tries to change behaviour towards WBV exposure. The near future will show if this intervention program is effective by showing a decrease in WBV exposure.</p

    Radiation Exposure from CT Examinations in Japan

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    <p>Abstract</p> <p>Background</p> <p>Computed tomography (CT) is the largest source of medical radiation exposure to the general population, and is considered a potential source of increased cancer risk. The aim of this study was to assess the current situation of CT use in Japan, and to investigate variations in radiation exposure in CT studies among institutions and scanners.</p> <p>Methods</p> <p>Data-sheets were sent to all 126 hospitals and randomly selected 14 (15%) of 94 clinics in Gunma prefecture which had CT scanner(s). Data for patients undergoing CT during a single month (June 2008) were obtained, along with CT scan protocols for each institution surveyed. Age and sex specific patterns of CT examination, the variation in radiation exposure from CT examinations, and factors which were responsible for the variation in radiation exposure were determined.</p> <p>Results</p> <p>An estimated 235.4 patients per 1,000 population undergo CT examinations each year, and 50% of the patients were scanned in two or more anatomical locations in one CT session. There was a large variation in effective dose among hospitals surveyed, particularly in lower abdominal CT (range, 2.6-19.0 mSv). CT examinations of the chest and upper abdomen contributed to approximately 73.2% of the collective dose from all CT examinations. It was estimated that in Japan, approximately 29.9 million patients undergo CT annually, and the estimated annual collective effective dose in Japan was 277.4 *10<sup>3 </sup>Sv person. The annual effective dose per capita for Japan was estimated to be 2.20 mSv.</p> <p>Conclusions</p> <p>There was a very large variation in radiation exposure from CT among institutions surveyed. CT examinations of the chest and upper abdomen were the predominant contributors to the collective dose.</p

    Soil water content effects on net ecosystem CO2 exchange and actual evapotranspiration in a Mediterranean semiarid savanna of Central Chile

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    Biosphere-atmosphere water and carbon fluxes depend on ecosystem structure, and their magnitudes and seasonal behavior are driven by environmental and biological factors. We studied the seasonal behavior of net ecosystem CO2 exchange (NEE), Gross Primary Productivity (GPP), Ecosystem Respiration (RE), and actual evapotranspiration (ETa) obtained by eddy covariance measurements during two years in a Mediterranean Acacia savanna ecosystem (Acacia caven) in Central Chile. The annual carbon balance was −53 g C m−2 in 2011 and −111 g C m−2 in 2012, showing that the ecosystem acts as a net sink of CO2, notwithstanding water limitations on photosynthesis observed in this particularly dry period. Total annual ETa was of 128 mm in 2011 and 139 mm in 2012. Both NEE and ETa exhibited strong seasonality with peak values recorded in the winter season (July to September), as a result of ecosystem phenology, soil water content and rainfall occurrence. Consequently, the maximum carbon assimilation rate occurred in wintertime. Results show that soil water content is a major driver of GPP and RE, defining their seasonal patterns and the annual carbon assimilation capacity of the ecosystem, and also modulating the effect that solar radiation and air temperature have on NEE components at shorter time scales.This work was funded by FONDECYT projects 1120713 and 1170429, a grant from the Inter-American Institute for Global Change Research (IAI) [grant number CRN3056], which is supported by the US National Science Foundation [grant number GEO-1128040], and the Spanish Ministry of Economy and Competitiveness project GEI Spain (CGL2014-52838-C2-1-R), including ERDF founds. F. Bravo-Martínez is grateful to CONICYT for the grants “Formación de Capital Humano Avanzado-2009′′, “Beca de Apoyo al término de la tesis doctoral-2012′′, and CORFO INNOVA Grant N° 09CN14-5704. We thank to Enrique Pérez Sanchez-Cañete and Borja Ruíz- Reverter for technical support. We also thank “CODELCO–División Andina” for use of the site. C. Montes acknowledges the NASA Postdoctoral Program and to Universities Space Research Association

    Amplification of wildfire area burnt by hydrological drought in the humid tropics

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    Borneo’s diverse ecosystems, which are typical humid tropical conditions, are deteriorating rapidly, as the area is experiencing recurrent large-scale wildfires, affecting atmospheric composition1, 2, 3, 4 and influencing regional climate processes5, 6. Studies suggest that climate-driven drought regulates wildfires2, 7, 8, 9, but these overlook subsurface processes leading to hydrological drought, an important driver. Here, we show that models which include hydrological processes better predict area burnt than those solely based on climate data. We report that the Borneo landscape10 has experienced a substantial hydrological drying trend since the early twentieth century, leading to progressive tree mortality, more severe than in other tropical regions11. This has caused massive wildfires in lowland Borneo during the past two decades, which we show are clustered in years with large areas of hydrological drought coinciding with strong El Niño events. Statistical modelling evidence shows amplifying wildfires and greater area burnt in response to El Niño/Southern Oscillation (ENSO) strength, when hydrology is considered. These results highlight the importance of considering hydrological drought for wildfire prediction, and we recommend that hydrology should be considered in future studies of the impact of projected ENSO strength, including effects on tropical ecosystems, and biodiversity conservation

    Reassessing the Evidence Hierarchy in Asthma: Evaluating Comparative Effectiveness

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    Classical randomized controlled trials are the gold standard in medical evidence because of their high internal validity. However, their necessarily strict design can limit their external validity and the ability to extrapolate these data to real world patients. Therefore, alternatively designed studies may play a complementary role in evaluating the comparative effectiveness of therapies in nonidealized patients in more naturalistic, real world settings. Observational studies have high external validity and can evaluate real world outcomes. Their strength lies in hypothesis generation and testing and in identifying areas in which further clinical trials may be required. Pragmatic trials are designed to maximize applicability of trial results to usual care settings by relying on clinically important outcomes and enrolling a wide range of participants. A combination of these approaches is preferable and necessary

    Prediction of Long-Term Benefits of Inhaled Steroids by Phenotypic Markers in Moderate-to-Severe COPD:A Randomized Controlled Trial

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    BACKGROUND:The decline in lung function can be reduced by long-term inhaled corticosteroid (ICS) treatment in subsets of patients with chronic obstructive pulmonary disease (COPD). We aimed to identify which clinical, physiological and non-invasive inflammatory characteristics predict the benefits of ICS on lung function decline in COPD. METHODS:Analysis was performed in 50 steroid-naive compliant patients with moderate to severe COPD (postbronchodilator forced expiratory volume in one second (FEV1), 30-80% of predicted, compatible with GOLD stages II-III), age 45-75 years, >10 packyears smoking and without asthma. Patients were treated with fluticasone propionate (500 μg bid) or placebo for 2.5 years. Postbronchodilator FEV1, dyspnea and health status were measured every 3 months; lung volumes, airway hyperresponsiveness (PC20), and induced sputum at 0, 6 and 30 months. A linear mixed effect model was used for analysis of this hypothesis generating study. RESULTS:Significant predictors of attenuated FEV1-decline by fluticasone treatment compared to placebo were: fewer packyears smoking, preserved diffusion capacity, limited hyperinflation and lower inflammatory cell counts in induced sputum (p<0.04). CONCLUSIONS:Long-term benefits of ICS on lung function decline in patients with moderate-to-severe COPD are most pronounced in patients with fewer packyears, and less severe emphysema and inflammation. These data generate novel hypotheses on phenotype-driven therapy in COPD. TRIAL REGISTRATION:ClinicalTrials.gov NCT00158847

    Leadership = Communication? The relations of leaders' communication styles with leadership styles, knowledge sharing and leadership outcomes

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    Purpose: The purpose of this study was to investigate the relations between leaders' communication styles and charismatic leadership, human-oriented leadership (leader's consideration), task-oriented leadership (leader's initiating structure), and leadership outcomes. Methodology: A survey was conducted among 279 employees of a governmental organization. The following six main communication styles were operationalized: verbal aggressiveness, expressiveness, preciseness, assuredness, supportiveness, and argumentativeness. Regression analyses were employed to test three main hypotheses. Findings: In line with expectations, the study showed that charismatic and human-oriented leadership are mainly communicative, while task-oriented leadership is significantly less communicative. The communication styles were strongly and differentially related to knowledge sharing behaviors, perceived leader performance, satisfaction with the leader, and subordinate's team commitment. Multiple regression analyses showed that the leadership styles mediated the relations between the communication styles and leadership outcomes. However, leader's preciseness explained variance in perceived leader performance and satisfaction with the leader above and beyond the leadership style variables. Implications: This study offers potentially invaluable input for leadership training programs by showing the importance of leader's supportiveness, assuredness, and preciseness when communicating with subordinates. Originality/value: Although one of the core elements of leadership is interpersonal communication, this study is one of the first to use a comprehensive communication styles instrument in the study of leadership. © 2009 The Author(s)
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