Leaching potential of phenylurea herbicides in a calcareous soil: comparison of column elution and batch studies

The transfer of eleven phenylurea herbicides through soil columns was investigated in laboratory conditions in order to determine leaching properties in a calcareous soil. Elution curves with distilled water were plotted after herbicide application on the soil column. Phenylurea retention by the soil indicating interactions with soil can be classified as follows: fenuron < fluometron ≤ isoproturon = monuron < metoxuron < monolinuron < metobromuron < chlorotoluron < linuron = diuron < chlorbromuron. The number and nature of halogen atoms on the phenyl ring had an important influence on leaching. Retention was higher for molecules with higher number of halogen, and it was also higher for bromine than chlorine. Column elution experiments were compared to batch experiments from which the distribution coefficients K _d were determined. According to Kendall correlation coefficients, parameter m/m _0max from column experiments was relatively well linked to K _d. In case of phenylurea, a linear relationship between K _d and m/m _0max was established.     

Combining chemical sequential extractions with 3D fluorescence spectroscopy to characterize sludge organic matter

The design and management of anaerobic digestion of sewage sludge (SS) require a relevant characterisation of the sludge organic matter (OM). Methods currently used are time-consuming and often insufficiently informative. A new method combining chemical sequential extractions (CSE) with 3D fluorescence spectroscopy was developed to provide a relevant SS characterisation to assess both OM bioaccessibility and complexity which govern SS biodegradability. CSE fractionates the sludge OM into 5 compartments of decreasing accessibility. First applied on three SS samples with different OM stability, fractionation profiles obtained were in accordance with the latter. 3D fluorescence spectroscopy revealed that the bioaccessible compartments were mainly constituted of simple and easily biodegradable OM while the unaccessible ones were largely made of complex and refractory OM. Then, primary, secondary and anaerobically digested sludge with different biodegradabilities were tested. Complexity revealed by 3D fluorescence spectroscopy was linked with biodegradability and chemical accessibility was correlated with sludge bioaccessibility.     

RECOTOX,a French initiative in ecotoxicology-toxicology to monitor,understand and mitigate the ecotoxicological impacts of pollutants in socioagroecosystems

RECOTOX is a cross-cutting initiative promoting an integrated research to respond to the challenges of monitoring, understanding, and mitigating environmental and health impacts of pesticides in agroecosystems. The added value of RECOTOX is to develop a common culture around spatial ecotoxicology including the whole chain of pressure-exposure-impact, while strengthening an integrated network of in natura specifically equipped sites. In particular, it promotes transversal approaches at relevant socioecological system scales, to capitalize knowledge, expertise, and ongoing research in ecotoxicology and, to a lesser extent, environmental toxicology. Thus, it will open existing research infrastructures in environmental sciences to research programs in ecotoxicology of pesticides.     

A longitudinal examination of role overload and work–family conflict: The mediating role of interdomain transitions

Through the lens of boundary theory, we examine whether the relationship between role overload and work–family conflict is explained by the use of interdomain transitions. With a sample of 250 working adults, we examined whether individuals respond to role overload by engaging in interdomain transitions and how the frequency of these transitions influences work–family conflict both concurrently and over time. Results support our expectation that at a given time, interdomain transitions function as an episodic coping mechanism with short‐term costs (greater work–family conflict) and benefits (less role overload). Also, engaging in interdomain transitions was an explanatory variable linking role overload and work–family conflict. We expected that, over time, engaging in interdomain transitions would function as a preventive coping mechanism, serving to reduce role overload. Interestingly though, several of the longitudinal hypotheses were counter to prediction. Our findings provide further evidence for the use of boundary theory in examinations of the work–family interface. Insights on areas within the literature that require further theoretical development are discussed, along with a consideration of the application of emerging methodologies within our empirical designs. Copyright © 2013 John Wiley & Sons, Ltd.     

A multi-criteria geographic information systems approach for the measurement of vulnerability to climate change

A flexible procedure for the development of a multi-criteria composite index to measure relative vulnerability under future climate change scenarios is presented. The composite index is developed using the Weighted Ordered Weighted Average (WOWA) aggregation technique which enables the selection of different levels of trade-off, which controls the degree to which indicators are able to average out others. We explore this approach in an illustrative case study of the United States (US), using future projections of widely available indicators quantifying flood vulnerability under two scenarios of climate change. The results are mapped for two future time intervals for each climate scenario, highlighting areas that may exhibit higher future vulnerability to flooding events. Based on a Monte Carlo robustness analysis, we find that the WOWA aggregation technique can provide a more flexible and potentially robust option for the construction of vulnerability indices than traditionally used approaches such as Weighted Linear Combinations (WLC). This information was used to develop a proof-of-concept vulnerability assessment to climate change impacts for the US Army Corps of Engineers. Lessons learned in this study informed the climate change screening analysis currently under way.     

Intraplacental sonolucent spaces: Incidences and relevance to chorionic villus sampling

Detailed ultrasound examination of the placentae from 293 consecutive women requesting first-trimester chorionic villus sampling (CVS) showed evidence of intraplacental sonolucent spaces with varying density in 42.3 per cent of these placentae. Their presence, however, did not complicate the subsequent course of these women's pregnancies. Their prime significance relates to CVS, where inadvertent entry into these areas can lead to bleeding and contamination of the villus specimens with blood. A search for these spaces should be made before sampling, and when present, they should be avoided wherever possible.     

Facultative sex-ratio adjustment in Norway rats: litters born asynchronously are female biased

Summary Previously we reported that inter-litter competition reduces the survival of pups born to pairs of female rats living and breeding in the same nesting environment. Inter-litter competition occurred when females gave birth asynchronously; specifically, when a female gave birth in the presence of 15 to 28-day-old pups, her newborn pups were likely to die as a result of nest intrusion by the older pups. In contrast, inter-litter competition occurred rarely when the two females gave birth synchronously. Because theories of facultative sex ratio adjustment predict that mothers giving birth in unfavorable circumstances should bias their offspring towards the more viable or less expensive sex, we predicted that litters born asynchronously would be female biased. Conversely, we also predicted that females giving birth under favorable conditions, i.e., synchronously, would bias their litters toward males. We found a female bias in asynchronous litters, but did not find a male bias in synchronous litters. Moreover, in contrast to other reports in the literature, the female bias in asynchronous litters was achieved without a reduction in litter size. Based on correlational data, we suggest several mechanisms that could produce this female bias: conditions at fertilization and implantation, time since the male last mated and number of pups suckling concurrently during gestation. Correspondence to: M.K. McClintock     

Follow-up of pregnancies complicated by placental mosaicism diagnosed by chorionic villus sampling

Thirty-nine (2.3 per cent) of 1724 chromosome studies from diagnostic chorionic villus samplings (CVS) done between 1983 and 1990 showed either level III (true) mosaicism (1.2 per cent) or level II (pseudo-) mosaicism (1.1 per cent) for chromosomal aneuploidy. Follow-up information on these 39 pregnancies was collected from questionnaires to families, paediatricians, and obstetricians. For all cases in which the pregnancy was continued and further testing was accomplished, the mosaicism was felt to be confined to the placenta. As compared with a control group of pregnancies evaluated by CVS with normal karyotypes, there was no increased incidence of pregnancy loss, congenital malformations, or developmental delay in the infants. Although intrauterine growth retardation occurred in several of the level III mosaic cases, adequate catch-up growth has been demonstrated.     

Presence of macrolide-lincosamide-streptogramin B and tetracycline antimicrobials in swine waste treatment processes and amended soil.

Little is known about the fate of antimicrobials during common agricultural waste handling procedures. To better define the potential scope of this problem, concentrations of antimicrobials throughout the waste treatment process were estimated based on known antimicrobial usage, and the resulting predictions of high antimicrobial concentrations indicated the need for further investigation. Samples from building pits, a solids settling basin, a holding pond, and soil amended with waste treatment byproducts were therefore analyzed for traditional chemical parameters and macrolide, lincosamide, and tetracycline antimicrobials. Substantial improvements in water quality were observed during the treatment process. While the macrolide tylosin was not detected, chlortetracycline, oxytetracycline, and lincomycin were found at high concentrations throughout the waste treatment process. Oxytetracycline and lincomycin were also detected in soil from a field amended with waste treatment byproducts.