Small but smart: the interaction between environmental cues and internal state modulates host-patch exploitation in a parasitic wasp

The reproductive success of insect parasitoids depends on two activities, searching for hosts to obtain immediate fitness rewards (offspring) and searching for food to extend life span and enhance future reproductive opportunities. Models suggest that to deal with this trade-off and to cope with the variability of the resources they depend on, parasitoids should simultaneously integrate information originating from three distinct sources: host and food availabilities in the environment (environmental information) and the metabolic reserves of the parasitoid (internal information). We tested whether, in the parasitic wasp Venturia canescens, these three types of information are perceived simultaneously and interact during host-patch exploitation. Experiments were performed with strains originating from two different geographical locations and with individuals of the two reproductive modes, arrhenotoky and thelytoky. We hypothesised that there would be differences between modes of reproduction as they thrive in different ecological conditions. Our results show that metabolic state, food availability and the number of ovipositions performed simultaneously modulate patch residence time in V. canescens of both populations and reproductive modes. Unfed wasps left their host patch earlier than fed ones. The tendency to leave the patch increased with an increasing probability of finding food. Our study confirms that globally, each oviposition increases the patch-leaving tendency (decremental mechanism). This effect was modulated by both the metabolic reserves and food availability, and the relationship depended on the geographic origin of populations. Individuals of one of the populations switched from a decremental to an incremental patch-leaving mechanism depending on the presence or absence of food in the vicinity. Differences between reproductive modes in the responses to environmental cues can be explained by the different ecological conditions they live in.     

Water to atmosphere fluxes of 131I in relation with alkyl-iodide compounds from the Seine Estuary (France)

This study presents an original work on measurements of stable and radioactive iodinated species in the Seine estuary (France), with estimates fluxes of volatile gaseous species from water to the atmosphere. Various iodinated compounds were identified in water and air in particular 131I in water, what is unusual. Concentrations and behaviour of iodinated elements in the Seine estuary seem similar to what has been observed in other European estuaries. MeI (Methyl Iodide) and Total Volatile Iodine (TVI) fluxes from water to air vary between 392 and 13949 pmol m(-2) d(-1) and between 1279 and 16484 pmol m(-2) d(-1), respectively. Water to air flux of TVI for the Seine river was estimated in the range 4-46 kg y(-1). Measurements of (131)I in water varying between 0.4 and 11.9 Bq m(-3). Fluxes of (131)I from water to atmosphere are in the range 2.4 x 10(5)-1.3 x 10(7)Bq y(-1), close to an annual discharge of (131)I by a nuclear reactor.     

Effect of metallic cations on the sorption of pesticides on soil

We studied the adsorption and desorption of two pesticides, namely isoproturon and dimetomorph, onto a model soil sample. We first show that the adsorption of isoproturon depends on pH, from 1 mg g⁻¹ at pH 4 to 2 mg g⁻¹ at pH 10, contrary to the adsorption of dimetomorph (5.8 mg g⁻¹). We also studied the influence of metallic cations, copper(II), iron(III), manganese(II), and chromium(III), on the sorption of isoproturon and dimetomorph. We found that in the case of isoproturon, the presence of metallic cations does influence the retention capacity of the soil sample. The sorption becomes very weak in the presence of copper and chromium, whereas in the case of iron and manganese the sorption properties are slightly modified.     

Community Participation in Natural Resources Management: Reality or Rhetoric?

In the developing world, the term ‘participation’ has in recent years become a household word in the same way that ‘democracy’ or ‘gender’ have. Development agencies are demanding increased participation in their programmes. The use of the word or its application has become a centre of debate. Due to the difficulties involved in measuring ‘participation’ or indeed determining levels at which participation should take place, who participates and when, many ‘doubting Thomases’ have questioned its effectiveness. It has, however been acknowledged in many areas that popular participation changes policies and enhances management and governance. In complex issues of natural resources management, participatory techniques have helped communities develop collective responsibilities towards management of their resources and projects. This paper discusses the complexities of community participation in natural resources management, ranging from interrelations among stakeholders to resource ownership based on the experiences in the Kasanka Game Management Area (KGMA). Lessons learnt from the Kasanka Game Management Area (GMA) communities, Serenje district, Zambia     

Low-dose aspirin for prevention of adverse outcomes related to abnormal placentation

Meta-analysis of randomized studies on the use of low-dose aspirin in women at high risk of preeclampsia (PE) has demonstrated that if treatment is initiated at ≤16 weeks' gestation, there is significant reduction in the risk of PE [relative risk (RR) 0.47, 95% confidence interval (CI) 0.36–0.62], fetal growth restriction (RR 0.46, 95% CI 0.33–0.64), preterm birth (RR 0.35, 95% CI 0.22–0.57) and perinatal death (RR 0.41, 95% CI 0.19–0.92), whereas the effect of treatment after 16 weeks is substantially less (RR 0.78, 95% CI 0.61–0.99; RR 0.98, 95% CI 0.88–1.08; RR 0.90, 95% CI 0.83–0.97; and RR 0.93, 95% CI 0.73–1.19, respectively). Moreover, the decrease in the risk of PE from early onset treatment seems to be related to the dose of aspirin, and a dose of >80 mg daily should be considered for optimal benefits. © 2014 John Wiley & Sons, Ltd.     

Blood Pb Levels in pregnant Nigerian women in Abakaliki, South-Eastern Nigeria

Environmental lead (Pb) exposure and toxicity have been recognised as public health problems of global importance, affecting both the developed and developing nations. In this work, blood Pb of pregnant women that were not exposed to lead by their occupation (n?=?349), with mean ± SD age of 27.0?±?4.8 years and gestational age of 21.8?±?3.1 weeks at recruitment were determined using atomic absorption spectrophotometer. The results showed that 309 (88.5 %) of the women had a mean?±?SD blood Pb of 40.0?±?16.5 μg/dl, which is higher than the current US Centre for Disease Prevention and Control action limit (>10 μg/dl). The observed high prevalence of elevated blood Pb levels may be related to maternal low socioeconomic status. Health education is, therefore, urgently needed to sensitise the general public and the policy makers of the level of Pb exposure in Abakaliki environment and the inherent health implications. In addition to mandatory environmental lead monitoring, blood Pb screening for would-be mother is recommended, and those whose blood Pb are found elevated should be appropriately treated.     

Towards an evaluation of accident investigation methods in terms of their alignment with accident causation models

The purpose of this paper is to reflect on accident causation models and accident investigation methods. Theories on accident causation and the modelling of accident mechanisms, as well as a number of methods for accident investigation have been developed and described in the literature. The evolution of accident causation models over time shows a shift from the sequence of events to the representation of the whole system. Respectively, the evolution of accident investigation methods over time reveals a gradual shift from searching for a single immediate cause, to the recognition of multiple causes. In order to evaluate the accident investigation methods, specific plausible requirements were established in order to verify that a specific accident investigation method fulfils the principles of a specific accident causation model or give evidence to the degree of alignment between them. Since different models approach accident causation in different ways, methods linked to these models provide fragmentary information regarding the accident. It is therefore expected that using a combination of model-method pairs could provide a more reliable platform for accident analysis.     

Contribution of a systemic modeling approach applied to support risk analysis of a storage unit of chemical products in Morocco

This paper proposes a new systemic modeling approach using the unified modeling language (UML) as an operational tool to model a complex industrial system and analyzes its risks. This approach is presented as a modeling process divided into three phases corresponding to functional analysis, structural analysis and risk analysis. This study aims to formalize the interactions within an industrial system and to identify the abnormal situations which could generate risks. The application of this approach is demonstrated with an example of a storage unit of chemical products located in Morocco. This approach provides a comprehensive view that facilitates the understanding of the organization of an industrial system and leads to more effective analysis of its safety.