荷兰莱茵河和墨兹河三角洲五斑按蚊麦赛变种和黑小按蚊幼体种群的分布及动态

本文研究了荷兰两南部莱茵河和默兹河三角洲地区五斑按蚊(Anopheles maculipennis)复合体蚊虫的分布及生态学.研究地区以前曾流行过疟疾,而黑小按蚊(A.atroparvus)则是唯一的传病媒介.对五斑按蚊的125处潜在的水生生境进行了采样,其中有47处(37.6%)含有这一物种复合体的幼体.     

Feasibility of storing CO2 in the Utsira formation as part of a long term Dutch CCS strategy: An evaluation based on a GIS/MARKAL toolbox

This study provides insight into the feasibility of a CO₂ trunkline from the Netherlands to the Utsira formation in the Norwegian part of the North Sea, which is a large geological storage reservoir for CO₂. The feasibility is investigated in competition with CO₂ storage in onshore and near-offshore sinks in the Netherlands. Least-cost modelling with a MARKAL model in combination with ArcGIS was used to assess the cost-effectiveness of the trunkline as part of a Dutch greenhouse gas emission reduction strategy for the Dutch electricity sector and CO₂ intensive industry. The results show that under the condition that a CO₂ permit price increases from €25 per tCO₂ in 2010 to €60 per tCO₂ in 2030, and remains at this level up to 2050, CO₂ emissions in the Netherlands could reduce with 67% in 2050 compared to 1990, and investment in the Utsira trunkline may be cost-effective from 2020–2030 provided that Belgian and German CO₂ is transported and stored via the Netherlands as well. In this case, by 2050 more than 2.1 GtCO₂ would have been transported from the Netherlands to the Utsira formation. However, if the Utsira trunkline is not used for transportation of CO₂ from Belgium and Germany, it may become cost-effective 10 years later, and less than 1.3 GtCO₂ from the Netherlands would have been stored in the Utsira formation by 2050. On the short term, CO₂ storage in Dutch fields appears more cost-effective than in the Utsira formation, but as yet there are major uncertainties related to the timing and effective exploitation of the Dutch offshore storage opportunities.     

Improving National-Scale Carbon Stock Inventories Using Knowledge on Land Use History

National-scale inventories of soil organic carbon (SOC) and forest floor carbon (FFC) stocks have a high uncertainty. Inventories are often based on the interpolation of sampled information, often using a number of covariables to help such interpolation. The rationale for the choice of these covariables is not always documented, despite the fact that many local-scale studies have identified the factors explaining spatial variability of SOC and FFC stocks. These studies indicate, among others the importance of long-term land use history. Despite this, information on the effects of land use history has never been used to explain variability of carbon stocks in national-scale inventories. We designed an alternative method to improve national-scale inventories of SOC and FCC for the Dutch sand area that takes stock of the findings of detailed case studies. Determinants for SOC and FFC stocks derived from landscape-scale case studies were used to map national-scale spatial variability and to calculate national totals. The resulting national-scale spatial distribution was compared with the SOC stock map from the current Dutch greenhouse gas inventory. Using land use history to explain SOC variability decreased the error of the SOC stock estimate in 60 % of the area. The error in FFC stocks decreased in half of the forest area after including soil fertility, tree species, and forest age as explanatory factors. Estimates with reduced uncertainty will make land use and land management a more attractive and acceptable mitigation option to reduce emissions of greenhouse gases for the LULUCF sector.     

The evaluation of the european home and leisure accident surveillance system

In 1986 the Council of Ministers of the European Community set up a 5-year demonstration project called the European Home and Leisure Accident Surveillance System (EHLASS); this project collects data on home and leisure accidents from accident and emergency departments of hospitals. The study reported upon in this paper evaluates the results of the demonstration project, in particular at the national level, and identifies problems that need to be resolved during the second stage of the project. The major finding of the study is that there are many good reasons for continuing EHLASS. The conditions for successful implementation of the system have been identified; these conditions relate to the methodology and the management of the system. The key element for a successful implementation of EHLASS is decentralization of technical responsibilities and reinforcement of the coordinating role of the European Commission.     

In Vitro Biodegradation of Polyester-Based Plastic Materials by Selected Bacterial Cultures

A simple and rapid in vitro test was designed for the assessment of the biodegradation of polyester-based plastics by selected biodegrading bacterial strains. Variovorax paradoxus LMG 16137 was used for the degradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and Acidovorax avenae subsp. avenae LMG 17238 fo the synthetic-based polyesters poly(-caprolactone) (PCL), poly(butylene succinate-co-butylene adipate), and a starch-PCL blend. Degradation by the bacteria was studied in liquid medium with the plastics (films, granules, and injection-molded test bars) as sole sources of carbon. Degradation was followed through gravimetry, growth of the culture, and tensile testing. The effects of incubation time, inoculum density, aeration, incubation temperature, and pH of the medium on the mass loss were investigated and conditions optimized. The test allowed to obtain reproducible results on the mass loss of plastic samples in less than 3 weeks and yielded excellent partially degraded samples for further analysis.     

Voluntary employee turnover: combining variables from the ‘traditional’ turnover literature with the theory of planned behavior

In this study we tried to answer the question of whether the three predictors from the theory of planned behavior provide a satisfactory explanation for intentions and behaviors in the context of voluntary employee turnover. We examined whether variables which have traditionally played a prominent role in the study of turnover, i.e., job satisfaction, organizational commitment, age, and tenure, were capable of explaining additional variance in turnover intentions and voluntary turnover. We conducted a longitudinal study in which 296 respondents serving as professionals in the Royal Netherlands Navy completed a questionnaire. Half a year later they were asked to answer a second identical questionnaire; data were obtained from 202 participants who answered all relevant questions in both questionnaires. Their actual behavior (staying versus leaving) was registered during a 2‐year period following the completion of the first questionnaire. Behavioral intentions proved to be the best predictor of turnover in which the effects of all other variables were accounted for. Job satisfaction and tenure explained a significant proportion of the variance in intentions after the effects of the predictors from the theory of planned behavior had been taken into account. The results are discussed in relation to theoretical, methodological, and practical issues. Copyright © 2004 John Wiley & Sons, Ltd.     

Prenatal detection of cystic fibrosis; comparative study of maltase and alkaline phosphatase activities in amniotic fluid

The potential value of microvillar enzymes in the prenatal diagnosis of cystic fibrosis (CF) has previously been demonstrated and is corroborated in the present comparative study. Maltase and alkaline phosphatase (ALP) activities were studied in the amniotic fluids of 57 pregnancies with a 1 in 4 risk for CF or with a known CF outcome and in 489 controls. A simple assay for maltase activity (MU-maltase) with the fluorogenic substate 4-methylumbelliferyl α-glucoside, offers great technical advantages and an at least equal detection rate of CF, when compared to the previously used test with maltose as substrate. Intestinal ALP was estimated either as phenylalanine inhibitable activity (PI-ALP) or as the proportions of residual activity in the presence of the inhibitors phenylalanine or homoarginine. MU-maltase and PI-ALP appeared the most successful methods: both tests were able to detect 14 of the 16 (88 per cent) pregnancies with fetal CF. Each of the two tests alone also allowed a correct prediction in 24 of the 25 pregnancies at risk but with normal outcome; however all 25 cases could be correctly predicted by a combined evaluation. It is suggested that more than one intestinal enzyme activity should be evaluated to allow optimal results in the prenatal monitoring of pregnancies at high risk for CF.     

Sex pheromones and their potential role in the evolution of reproductive isolation in small ermine moths (Yponomeutidae)

Summary Sex pheromone communication in the nine European species of small ermine moths (Yponomeuta) is reviewed in regard to the potential role of pheromones in the speciation process. Six of the nine species studied (viz.,Y. evonymellus, Y. cagnagellus, Y. padellus, Y. irrorellus, Y. plumbellus, andY. vigintipunctatus) use a mixture of (E)-11-and (Z)-11-tetradecenyl acetate in different ratios as primary pheromone components, with combinations of tetradecyl acetate, (Z)-9-tetradecenyl acetate, (Z)-11-hexadecenyl acetate and the corresponding alcohols of the acetates as additional pheromone components. Analysis of (Z)- to (E)-11-tetradecenyl acetate ratios produced by individual females of these species demonstrated significant variation among females of all species. However, the ranges of ratios produced byY. cagnagellus, Y. irrorellus, andY. plumbellus, sharing the same host-plant species, spindle tree, did not overlap. Niche separation of all six species mentioned required consideration of at least one additional pheromone component or of temporal aspects. The remaining three species,i.e. Y. malinellus, Y. mahalebellus andY. rorellus, have pheromones that differ qualitatively.Biosynthetic routes to the pheromone components identified are proposed on the basis of fatty acid pheromone precursors found in the pheromone glands. A phylogenetic tree for the genus is constructed based on allozyme frequency data and changes in pheromone composition are superimposed on this tree. We suggest that the ancestral ermine moth pheromone is a mixture of (Z)-11- and (E)-11-tetradecenyl acetate and the corresponding alcohols, and a scenario of how present-day patterns evolved is outlined. The pheromone differences among the three species using spindle tree as their host-plant might have evolved throughreproductive character displacement upon secondary contact between populations that had already diverged genetically in allopatry. Pheromone differences within the so-calledpadellus-complex (includingY. cagnagellus, Y. mahalebellus, Y. malinellus, Y. padellus, andY. rorellus) in which species might have originated sympatrically, may have evolved byreinforcing selection as these species still hybridise and produce viable offspring when confined in cages. The role of pheromones in reproductive isolation amongYponomeuta species is emphasised by (1) the function of pheromone components of some of the species as behavioural antagonists to other species, (2) the cross-attraction under experimental conditions between allochronic species with similar pheromones, and (3) the formation of hybrids in the laboratory between species that are isolated in nature by pheromone differences.