Adaptive responses to local mate competition by the parasitoid,Telenomus remus

Summary The parasitic wasp, Telenomus remus, lays her eggs in diserete patches of moth eggs, where her offspring develop and mate before dispersal, satisfying conditions for local mate competition (LMC). In the presence of other ovipositing females, wasps lay a higher sex ratio (proportion males), as predicted by LMC theory, and achieve this by a combination of two mechanisms, (1) avoidance of superparasitism and a sequence of sex allocation initially biased towards males and (2) a direct increase in sex ratio in the presence of other wasps, sex ratio increases with the proportion of previously parasitized hosts, as predicted by LMC theory. In both cases, chemical traces left by foraging wasps are indicated as the stimuli causing wasps to increase the proportion of males allocated to hosts.     

Dealing with Ambivalence: Farmers' and Consumers' Perceptions of Animal Welfare in Livestock Breeding

The results of an empirical study intoperceptions of the treatment of farm animals inthe Netherlands are presented. A qualitativeapproach, based on in-depth interviews withmeat livestock farmers and consumers was chosenin order to assess motivations behindperceptions and to gain insight into the waypeople deal with possible discrepancies betweentheir perceptions and their daily practices.Perceptions are analyzed with the help of aframe of reference, which consists ofvalues, norms, convictions, interests, andknowledge.The perceptions of the interviewed farmersare quite consistent and without exceptionpositive: according to them, nothing is wrongwith animal welfare in livestock breeding. Theperceptions of the consumers we interviewed aremore divergent, but generally negative. Bothgroups show ambivalence as a result ofdiscrepancies between perceptions and behavior.Although the consumers share the impressionthat the living conditions of livestock animalsare far from optimal, most of them still buyand eat meat from the meat industry. Thefarmers believe the welfare of their animals isgood, but, as frequent defensive utterancesshow, they feel uncomfortable with expressed orunexpressed accusations of mistreating animals.The ways the respondents deal with thisambivalence were analysed by drawing ontheories of dissonance reduction and distancing devices.Catherine and Raphaël Larrère(Larrère and Larrère, 2000) argue thatanimal rearing is a hierarchical relationshipwhose rules are to be found in the fiction of adomestic contract. We argue that the questionis not whether there should be a domesticcontract, because such a contract seems alreadyaccepted. However, since values and normsdiffer widely, not only among meat livestockfarmers and consumers, but also amongconsumers, the question remains as to whosevalues and norms should form the basis of thedomestic contract.     

Analysis of the influencing factors of PAEs volatilization from typical plastic products

The primary emphasis of this research was to investigate the foundations of phthalate(PAEs) pollutant source researches and then firstly confirmed the concept of the coefficient of volatile strength, namely phthalate total content in per unit mass and unit surface area of pollutant sources. Through surveying and evaluating the coefficient of volatile strength of PAEs from typical plastic products, this research carried out reasonable classification of PAEs pollutant sources into three categories and then investigated the relationship amongst the coefficient of volatile strength as well as other environmental factors and the concentration level of total PAEs in indoor air measured in environment chambers.Research obtained phthalate concentration results under different temperature, humidity,the coefficient of volatile strength and the closed time through the chamber experiment. In addition, this study further explored the correlation and ratio of influencing factors that affect the concentration level of total PAEs in environment chambers, including environmental factors, the coefficient of volatile strengths of PAEs and contents of total PAEs in plastic products. The research created an improved database system of phthalate the coefficient of volatile strengths of each type of plastic goods, and tentatively revealed that the volatile patterns of PAEs from different typical plastic goods, finally confirmed that the coefficient of volatile strengths of PAEs is a major factor that affects the indoor air total PAEs concentration, which laid a solid foundation for further establishing the volatile equation of PAEs from plastic products.     

Ensemble Bayesian model averaging using Markov Chain Monte Carlo sampling

Bayesian model averaging (BMA) has recently been proposed as a statistical method to calibrate forecast ensembles from numerical weather models. Successful implementation of BMA however, requires accurate estimates of the weights and variances of the individual competing models in the ensemble. In their seminal paper (Raftery et al. Mon Weather Rev 133:1155–1174, 2005) has recommended the Expectation–Maximization (EM) algorithm for BMA model training, even though global convergence of this algorithm cannot be guaranteed. In this paper, we compare the performance of the EM algorithm and the recently developed DiffeRential Evolution Adaptive Metropolis (DREAM) Markov Chain Monte Carlo (MCMC) algorithm for estimating the BMA weights and variances. Simulation experiments using 48-hour ensemble data of surface temperature and multi-model streamflow forecasts show that both methods produce similar results, and that their performance is unaffected by the length of the training data set. However, MCMC simulation with DREAM is capable of efficiently handling a wide variety of BMA predictive distributions, and provides useful information about the uncertainty associated with the estimated BMA weights and variances.     

Monitoring of abiotic compartments for trace metals: Difficulties,strategies and the use of surveys

The high variabilility in coastal water parameters allows no effective large scale monitoring exercise within acceptable logistic and economic means; however, in the ideal case monitoring of marine pollution should comprise biotic and abiotic compartments. Different regions, e.g. turbulent, polluted, turbid coastal areas, relative clear clean open sea and relatively undisturbed sediments require their specific approach, for which strategies are presented.Based on surveys from the Dutch Wadden Sea and North Sea, the dissolved and particulate water fractions and sediment are discussed in terms of possible objects for monitoring.     

Policy and planning in the dutch countryside: The role of regional innovation networks

This paper presents the results of a study on the functioning of regional innovation networks (RINs) in the Netherlands. RINs are designed to achieve sustainable and socially acceptable regional economic development. By focusing on inter-human processes, the study aimed to gain more and deeper insights into the nature, the workings, the potential and the limitations of RINs in processes of innovation. An important insight from the study concerns the role of governments in RINs. Although the intention of the central government was to experiment with a fully bottom-up process, all RINs were eager to involve the government at different levels, at different times and for different purposes.     

Helping to improve suggestion systems: predictors of making suggestions in companies

Predictors of submitting suggestions and their quality were studied in a Dutch company with a well‐developed suggestion system (n=207 blue collar workers). A model with person variables (initiative at work, higher order need strength, control aspirations, and interest in work innovation), work characteristics (control and complexity), motives (better work, reward), self‐efficacy, and system factors (system inhibitors, system responsiveness, and supervisor support) was developed and tested. They are related to the three process variables, deemed to be important in making a suggestion: having ideas, submitting suggestions and quality of the suggestions. A path analysis revealed that the most important factors related to these process variables were initiative at work, higher order need strength, self‐efficacy, expected improvements in work and suggestion inhibitors (negatively). Copyright © 1999 John Wiley & Sons, Ltd.