515 research outputs found
Effect of diet versus diet and exercise on weight loss and body composition in class II and III obesity: A systematic review
Class II and III obesity (BMI >35 kg·m2) have increased dramatically in recent years. Current clinical guidelines suggest diet and exercise as first line treatment for adults throughout the spectrum of overweight and obesity. However, to date there is no systematic review that examines the effects of diet and exercise on this high risk population. This systematic review will examine the combined effects of diet versus diet and exercise on body composition in severe obesity. Medline and Cinahl were searched for randomised controlled trials comparing diet and exercise to diet alone. Studies published until July 2013 were included if they used reliable methods for analysing body composition in adults with BMI ≥ 35 kg·m2. Five of 459 studies met the inclusion criteria. Two studies, both in older adults, reported that exercise reduced lean mass loss during weight loss. Two studies showed that exercise facilitated (greater) fat mass loss. The remaining study reported no differences in body composition when exercise is added to energy restriction. Exercise training during energy restriction for individuals with BMI ≥35 kg.m2 may influence body composition outcomes but the evidence is limited. Further studies should focus on the efficacy of different exercise protocols during energy restriction for this population in order to better inform decision making for the treatment of severe obesity in respect to favourable body composition outcomes
Experimental study of surface curvature effects on aerodynamic performance of a low Reynolds number airfoil for use in small wind turbines
This paper presents the wind tunnel experimental results to investigate the effects of surface gradient-of-curvature on aerodynamic performance of a low Reynolds number airfoil Eppler 387 for use in small-scale wind turbines. The prescribed surface curvature distribution blade design method is applied to the airfoil E387 to remove the gradient-of-curvature discontinuities and the redesigned airfoil is denoted as A7. Both airfoils are manufactured with high precision to reflect the design. Low-speed wind tunnel experiments are conducted to both airfoils at chord based Reynolds numbers 100 000, 200 000, and 300 000. Surface pressure measurements are used to calculate the lift and pitching-moment data, and the wake survey method is applied to obtain the drag data. The experimental results of E387 are compared with NASA Low Turbulence Pressure Tunnel (LTPT) results for validation. The gradient-of-curvature discontinuities of E387 result in a larger laminar separation bubble which causes higher drag at lower angles of attack. As the angle of attack increases the separation bubble of the airfoil E387 moves faster towards the leading edge than that of A7, resulting in a premature bubble bursting and earlier stall on E387. The impact of the gradient-of-curvature distribution on the airfoil performance is more profound at higher angles of attack and lower Reynolds number. The aerodynamic improvements are integrated over the 3D geometry of a 3 kW small wind turbine, resulting in up to 10% increase in instantaneous power and 1.6% increase in annual energy production. It is experimentally concluded that an improved curvature distribution results in a better airfoil performance, leading to higher energy output efficiency
Evaluating the impact of accounting for coral cover in large‐scale marine conservation prioritizations
Aim
Mega‐diverse coral reef ecosystems are declining globally, necessitating conservation prioritizations to protect biodiversity and ecosystem services of sites with high functional integrity to promote persistence. In practice however, the design of marine‐protected area (MPA) systems often relies on broad classifications of habitat class and size, making the tacit assumption that all reefs are of comparable condition. We explored the impact of this assumption through a novel, pragmatic approach for incorporating variability in coral cover in a large‐scale regional spatial prioritization plan.
Location
The Coral Triangle.
Methods
We developed a spatially explicit predictive model of hard coral cover based on freely available macro‐ecological data to generate a complete regional map of coral cover as a proxy for reef condition. We then incorporate this information in spatial conservation prioritization software Marxan to design an MPA system that meets specific conservation objectives.
Results
We discover prioritizations using area‐based representation of reef habitat alone may overestimate the conservation benefit, defined as the amount of hard coral cover protected, by up to 64%. We find substantial differences in conservation priorities and an overall increase in habitat quality metrics when accounting for predicted coral cover.
Main conclusions
This study shows that including habitat condition in a large‐scale marine spatial prioritization is feasible within time and resource constraints, and calls for increased implementation, and evaluation, of such ecologically relevant planning approaches to enhance potential conservation effectiveness
Direct measurement of key exciton properties: Energy, dynamics, and spatial distribution of the wave function
Excitons, Coulomb-bound electron-hole pairs, are the fundamental excitations governing optoelectronic properties of semiconductors. While optical signatures of excitons have been studied extensively, experimental access to the excitonic wave function itself has been elusive. Using multidimensional photoemission spectroscopy, we present a momentum-, energy- and time-resolved perspective on excitons in the layered semiconductor WSe2. By tuning the excitation wavelength, we determine the energy-momentum signature of bright exciton formation and its difference from conventional single-particle excited states. The multidimensional data allows to retrieve fundamental exciton properties like the binding energy and the exciton-lattice coupling and to reconstruct the real-space excitonic wave function via Fourier transform. All quantities are in excellent agreement with microscopic calculations. Our approach provides a full characterization of the exciton wave function and is applicable to bright and dark excitons in semiconducting materials, heterostructures, and devices
Roll Maneuver Control of UCAV Wing Using Anisotropic Piezoelectric Actuators
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76333/1/AIAA-2002-1720-656.pd
Public policy action and CCC implementation: benefits and hurdles
Policy change continues to be an increasingly effective means of advancing the agenda of comprehensive cancer control. Efforts have moved progressively from describing how public policy can enhance the comprehensive cancer control agenda to implementation of public policy best practices at both the state and federal levels. The current political and economic contexts bring additional challenges and opportunities to the efforts surrounding comprehensive cancer control and policy. The purpose of this paper is to highlight recent policy successes, to illustrate the importance of policy as a means of advancing the comprehensive cancer control agenda, and to discuss continued policy action as we move forward in a time of healthcare reform and continuing economic uncertainty
DEVELOPING NEW APPROACHES TO GLOBAL STOCK STATUS ASSESSMENT AND FISHERY PRODUCTION POTENTIAL OF THE SEAS
Stock status is a key parameter for evaluating the sustainability of fishery resources and developing
corresponding management plans. However, the majority of stocks are not assessed, often as a result of
insufficient data and a lack of resources needed to execute formal stock assessments. The working
group involved in this publication focused on two approaches to estimating fisheries status: one based
on single-stock status, and the other based on ecosystem production.JRC.G.4-Maritime affair
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A Multilevel Measurement Model of Social Cohesion
In spite of its currency both in academic research and political rhetoric, there are numerous attempts to define and conceptualize the social cohesion concept but there has been paid little attention to provide a rigorous and empirically tested definition. There are even fewer studies that address social cohesion in a framework of cross-cultural validation of the indicators testing the equivalence of the factorial structure across countries. Finally, as far as we know there is no study that attempt to provide an empirically tested multilevel definition of social cohesion specifying a Multilevel Structural Equation Model. This study aims to cover this gap. First, we provide a theoretical construct of social cohesion taking into account not only its multidimensionality but also its multilevel structure. In the second step, to test the validity of this theoretical construct, we perform a multilevel confirmatory factor analysis in order to verify if the conceptual structure suggested in first step holds. In addition, we test the cross-level structural equivalence and the measurement invariance of the model in order to verify if the same multilevel model of social cohesion holds across the 29 countries analysed. In the final step, we specify a second-order multilevel CFA model in order to identify the existence of a general factor that can be called “social cohesion” operating in society that accounts for the surface phenomena that we observe
A Cross-Lagged Panel Analysis of Fear Appeal Appraisal and Student Engagement
Background: Fear appeals are persuasive messages given by teachers to students about the importance of avoiding failure in an upcoming high-stakes test. The relationship between the way that students appraise fear appeals and engagement in lessons has not previously been tested using a robust methodological and analytical design that fully controls for concurrent relationships between the variables and stability over time.
Aim: The present study addressed these limitations using a cross-lagged panel design to probe reciprocal relationships between students’ appraisal of fear appeals as a threat and as a challenge, with their engagement in class.
Sample: A total of 2,025 Year 10 and 11 students took part.
Method: Fear appeal appraisal and student engagement were measured at two time-points, four months apart.
Results: After controlling for unlagged and auto-lagged correlations, and gender and year group, the model fit the data well and six cross-lagged paths emerged as statistically significant. Threat appraisal and emotional engagement were reciprocally, negatively related. Threat appraisal also positively predicted emotional disaffection and challenge appraisal negatively predicted behavioural disaffection. In addition, prospective relations were revealed between specific components of student engagement.
Conclusions: Classroom teachers need to be aware of the possible consequences of making fear appeals and moderate this aspect of their practice accordingly. It would also be beneficial for educational interventions to focus on promoting challenge appraisals of fear appeals
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