Organic agriculture and ecosystem services

Ecosystem services (ES), such as biological control, pollination, soil formation, nutrient cycling in agriculture are vital for the sustainable supply of food and fibre. The current trends of decline in the ability of agricultural ecosystems to provide ES pose great threat to food security worldwide. This paper discusses the concept of ES and identifies ES associated with agriculture. It discusses the economic and ecological benefits of these ES on farmland in general and its linkages with organic agriculture. The provision of ES on farmland may help to motivate the redesign of small-scale farms using new eco-technologies based on novel and sound ecological knowledge. This has potential to meet the food demand of growing population without damaging human health and the environment.     

Achieving forest carbon information with higher certainty: A five-part plan

International negotiations on the inclusion of land use activities into an emissions reduction system for the UN Framework Convention on Climate Change (UNFCCC) have been partially hindered by the technical challenges of measuring, reporting, and verifying greenhouse gas (GHG) emissions and the policy issues of leakage, additionality, and permanence. This paper outlines a five-part plan for estimating forest carbon stocks and emissions with the accuracy and certainty needed to support a policy for Reducing Emissions from Deforestation and forest Degradation, forest conservation, sustainable management of forests, and enhancement of forest carbon stocks (the REDD-plus framework considered at the UNFCCC COP-15) in developing countries. The plan is aimed at UNFCCC non-Annex 1 developing countries, but the principles outlined are also applicable to developed (Annex 1) countries. The parts of the plan are: (1) Expand the number of national forest carbon Measuring, Reporting, and Verification (MRV) systems with a priority on tropical developing countries; (2) Implement continuous global forest carbon assessments through the network of national systems; (3) Achieve commitments from national space agencies for the necessary satellite data; (4) Establish agreed-on standards and independent verification processes to ensure robust reporting; and (5) Enhance coordination among international and multilateral organizations.     

崇明东滩湿地沉积物重金属污染的磁诊断

对取自崇明东滩的高潮滩、中潮滩和低潮滩的沉积物柱样进行了磁学、粒度、重金属含量等指标的分析、比较与综合研究. 结果表明:在以粉砂为主的崇明东滩,通过污染负荷指数法进行评价,除低潮滩无污染外,中潮滩和高潮滩均有中度的重金属污染. 选取中度重金属污染的高潮滩沉积物柱样进行粒度、重金属含量以及磁性参数的相关性分析显示,χ_fd,χ_ARM/SIRM与重金属含量和粘土(粒径<4 μm)之间有较高的相关性,并以此建立了磁诊断线性回归模型;χ_fd和χ_ARM/SIRM可作为重金属含量的替代指标.      

The need for work: Jahoda's latent functions of employment in a representative sample of the German population

Marie Jahoda's latent deprivation model was tested with a representative sample of the German population (N = 998). As expected, employees reported high levels of time structure, social contact, collective purpose, and activity not only in comparison to unemployed persons but also in comparison to persons who are out of the labor force (i.e., students, homemakers, retirees). Even unskilled manual workers reported more access to these “latent functions” than persons without employment. For the fifth of Jahoda's dimensions, identity/status, no significant differences between employed persons and persons who are out of the labor force could be identified. However, unemployed persons reported less status than all other groups did. Thus, Jahoda's model was clearly endorsed for four of the five latent functions of employment and partly endorsed for the fifth function. All variables in the model correlated significantly with distress, as expected. Demographic correlates of the manifest and latent functions were also analyzed: Access to the latent functions was best among young men from higher social classes who lived in an intimate relationship in a comparatively large household with children. Copyright © 2009 John Wiley & Sons, Ltd.     

Analysis of running child pedestrians impacted by a vehicle using rigid-body models and optimization techniques

Lack of information from vehicle-to-child pedestrian impacts provides considerable challenges when developing vehicle countermeasures for the pediatric population. Crash reconstructions of real-world incidents provide useful information about the vehicle damage and injury outcome but do not permit definitive and quantitative measures of the impact severity given the high level of uncertainty in the initial conditions of the pedestrian and the vehicle prior the impact. This paper develops an advanced methodology for reconstructing child pedestrian–vehicle impacts that combines the crash data with multi-body simulations and optimization techniques for identifying the pedestrian posture and vehicle speed prior to impact. For the child pedestrian posture, a continuous sequence of the running gait was developed based on the literature data and simulations. Using vehicle damage information from an actual child pedestrian crash, an objective function was developed that minimized the difference between vehicle and pedestrian contact points for the simulated child postures, pedestrian, and vehicle speeds. Simulated annealing and genetic optimization algorithms were used to identify sets of potential solutions for the pedestrian and vehicle initial conditions. Local minimums were observed for several response surfaces of the objective function which shows the non-convex nature of the crash reconstruction optimization problem with the chosen objective function. Based on the results of the real-world reconstruction, this study indicates that numerical simulations coupled with heuristic optimization algorithms can be used to reconstruct child pedestrian and vehicle pre-impact conditions.     

Evaluating safety management and culture interventions to improve safety: Effective intervention strategies

The Dutch Ministry of Social Affairs and Employment provided subsidy over the period 2004–2008 to a number of companies to introduce changes aimed at reducing accidents by changing their safety culture and aspects of their safety management. As part of the programme a scientific evaluation was set up to assess the effectiveness of the interventions in 17 of the projects, covering 29 companies. Before and after studies were made of the companies, documenting the state of their safety management and risk control efforts and their accident rates before the intervention, the changes made over the study period and the resulting changes in a range of measures aimed at assessing the success of the changes. The analysis led to a categorisation of the projects according to their degree of success.This paper describes the patterns of interventions distinguishing between successful and not successful projects and discusses the mechanisms lying behind them. Interventions bringing about constructive dialogue between shop-floor and line management, providing motivation to line managers and strengthening the monitoring and learning loops in the safety management system (SM) appeared more successful. The amount of energy and creativity injected by top managers and, above all, by the coordinator (safety professional) appeared also to be a distinguishing factor.     

A viscosity correction factor for shear-thinning liquid flows in safety valves

At the moment there is lack in the existing standards of a sizing procedure for media of more complex rheological behavior than Newtonian. A formulation for the generalized Reynolds number to calculate the viscosity correction factor and size safety valves for the flows of shear-thinning media is proposed in this work. The various formulations in the literature are validated in their accuracy of estimation of the mass flow rates of aqueous solutions of polyvinylpyrrolidone. Among them the generalized Reynolds number defined using the wall viscosity of the annulus between the seat and the disk gives the highest accuracy without overestimating the measured mass flow rates. On the base of these results this generalized Reynolds number is recommended for introduction in the next review of both ISO 4126-1 Part 1 and API 520 for the sizing of safety valves for shear-thinning media.     

Restraint use and seating position among children less than 13 years of age: Is it still a problem?

Introduction

The purpose of this study was to calculate national estimates and examine the extent to which children prematurely use adult seat belts and ride in the front seat of a vehicle during a 30 day period.

Methods

Data were obtained from a nationally representative cross-sectional random-digit-dial telephone survey that included child-specific questions on motor vehicle restraint use and seating position.

Results

Among children less than 13 years, parents reported an estimated 618,337 who rode unrestrained and more than one million who rode in the front seat of a vehicle at least some of the time in the past 30 days. During the same time period, close to 11 million children 8 years and younger reportedly used only adult seat belts.

Discussion

Our results highlight the need for continued outreach to parents regarding optimal restraint use and rear seating position for children every trip, every time.     

The mediating role of job characteristics in job redesign interventions: A serendipitous quasi‐experiment

The aim of this paper is to examine the mediating role played by five key job characteristics in the relationship between employee participation in a job redesign intervention and employee well‐being. In studies of job redesign interventions, it has been assumed that any effects of employee participation in job redesign on well‐being are a result of changes in job characteristics rather than participation in change per se. It is therefore important to statistically test for mediation in job redesign intervention studies to help establish that the change in job characteristics is the mechanism through which job redesign interventions work. However, this has rarely been tested directly, either because data to allow tests of mediation have not been collected (e.g. assessments of job characteristics) or because data have been collected but mediation has not been tested using accepted procedures. This makes it unclear whether changes in job characteristics explain the effects. Results from multilevel analyses of a longitudinal 9‐month long serendipitous quasi‐experimental participative job redesign intervention showed that changes in job control, participation, skill utilization and feedback, but not task obstacles, were sufficient to account for the relationship between the intervention and employee well‐being. Copyright © 2009 John Wiley & Sons, Ltd.