An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 2: impacts on organisms and ecosystems

Environmental Science and Pollution Research - New information on the lethal and sublethal effects of neonicotinoids and fipronil on organisms is presented in this review, complementing the...     

<Emphasis Type="Italic">A Posteriori</Emphasis> Evaluation of Strategies of Management: The Effectiveness of No-Wash Zones in Minimizing the Impacts of Boat-Wash on Macrobenthic Infauna

Wind-driven waves are important in structuring intertidal and shallow subtidal assemblages of macrobenthic infauna. In the sheltered waters of estuaries, boat-generated waves (wash) may play a similar role because they are typically of a similar amplitude or larger than wind-driven waves. However, few studies have attempted to determine the role of wash in structuring assemblages. Consequently, strategies for managing boating focus around minimization of bank erosion. Along the Parramatta River (Sydney, Australia), no-wash zones have been established and mangroves planted to minimize the erosion of riverbanks and collapse of seawalls purportedly caused by 35-m-long RiverCat ferries. Although intended to also reduce the ecological impacts of wash, it is unclear whether these strategies achieve this goal. Unvegetated and vegetated (among the pneumatophores of mangroves) sediments were sampled in wash and no-wash zones along the Parramatta River to assess the effectiveness of no-wash zones and vegetation of river banks in reducing the ecological impacts of wash. Specifically, it was hypothesized that (1) assemblages of intertidal macrobenthic infauna would differ between wash and no-wash zones of the Parramatta River and (2) these differences would be greater in unvegetated than in vegetated habitat. As predicted, assemblages of macrobenthic infauna differed between the wash and no-wash zones. Capitellids, nereids, and spionids were more abundant in the no-wash zone. Contrary to the hypothesis, differences were no greater in the unvegetated habitat than in the vegetated habitat. The results suggest an impact of wash on assemblages of macrobenthic infauana and a role for no-wash zones in minimizing the effects of this disturbance.     

Bridging the gap between cell biology and organic chemistry: chemical synthesis and biological application of lipidated peptides and proteins

We have developed a basic concept for studying cell biological phenomena using an interdisciplinary approach starting from organic chemistry. Based on structural information available for a given biological phenomenon, unsolved chemical problems are identified. For their solution, new synthetic pathways and methods are developed, which reflect the state of the art in synthesising lipidated peptide conjugates. These compounds are used as molecular probes for the investigation of biological phenomena that involve both the determination of biophysical properties and cell biological studies. The interplay between organic synthesis, biophysics and cell biology in the study of protein lipidation may open up new and alternative opportunities to gain knowledge about the biological phenomenon that could not be obtained by employing biological techniques alone. This fruitful combination is highlighted using the Ras protein as an outstanding example. Included herein is: the development of methods for the synthesis of Ras-derived peptides and fully functional Ras proteins, the determination of the biophysical properties, in particular the ability to bind to model membranes, and finally the use of synthetic Ras peptides and proteins in cell biological experiments.     

Estimation of the weight of chorionic villus samples obtained from first trimester pregnancies by transcervical aspiration

Eight obstetricians experienced in chorionic villus sampling were asked to estimate the weight of samples of villi with and without a reference photograph. Referral to the photograph significantly improved the accuracy of their estimations.     

Genetic Analysis of the Endangered Island Endemic Malacothamnus fasciculatus (Nutt.) Greene var. nesioticus (Rob.) Kearn. (Malvaceae)

Isozyme, randomly amplified polymorphic DNA, and ribosomal DNA analyses were used to evaluate the genetic distinctness and diversity of the endangered island endemic Malacothamnus fasciculatus var. nesioticus (Santa Cruz Island bush mallow). Analysis of amplified DNA profiles and electrophoretic data indicates that var. nesioticus is genetically distinct from other varieties within the species. No isozyme or amplified DNA variation was detected among individuals of nesioticus populations, but restriction site analysis of ribosomal DNA revealed the presence of three closely related genotypes within one of the nesioticus populations. Apparent clonal structuring was found in both nesioticus populations and in one mainland population, var. nuttallli . Results from these analyses provide the background necessary for the design of conservation efforts with recovery goals that insure the long-term survival of Malacothamnus fasciculatus var. nesioticus .     

Employed mothers: Interrole conflict,spouse support and marital functioning

Increased participation by mothers in the labour force may exert a negative effect on working mothers themselves (e.g. interrole conflict) and influence the marital relationship negatively. Recent research suggests that not all individuals experiencing psychological distress suffer psychological strain (e.g. marital discord). Rather, variables such as social support moderate negative effects of psychological stressors. To test this, sixty-four employed mothers (M age = 36 years) completed interrole conflict and spouse support scales. Marital satisfaction, verbal and nonverbal communication were the criteria operationalized to assess marital functioning. Using moderated multiple regression analyses, interrole conflict and spouse support predicted marital satisfaction and verbal communication significantly. In addition, spouse support may moderate negative effects of interrole conflict on marital satisfaction and verbal communication. With regard to nonverbal communication, spouse support was both a significant main effect and possibly a moderator of interrole conflict. The role of spouse support, conceptual and treatment implications, and future research priorities are identified.     

Pathway of CH4 formation in anoxic rice field soil and rice roots determined by 13C-stable isotope fractionation

In anoxic rice fields methane is produced by either reduction of CO2 or cleavage of acetate. We measured the delta 13C-values of CH4 and CO2, acetate and organic carbon during time course experiments with anoxic methanogenic soil and root samples and used these values to calculate the fractions of CH4 (and acetate) produced from CO2 reduction. Comparison with radiotracer and/or inhibitor studies constrained the kinetic fractionation factors used for calculation. The fractionation factors for the conversion of CO2 to CH4 and of acetate to CH4 were on the order of alpha = 1.07 (epsilon = -70%) and epsilon > or = - 20%, respectively. The pathway of CH4 production changed with time of anoxic incubation. Anoxic slurries of rice field soil first produced CH4 predominantly (>50%) from CO2, then predominantly (>80%) from acetate and finally (after about one month) according to the theoretically expected ratio (33% CO2 and 67% acetate). Anoxic rice roots, on the other hand, initially produced CH4 exclusively from CO2, followed by contribution of acetate of about 40-60%. Rice roots also produced acetate that partially originated (< or = 1 30%) from reduction of CO2 as determined by calculation of isotopic fractionation using fractionation factors from the literature. The results demonstrate that there is quite some variability in pathways of CH4 production, and also indicate that isotopic fractionation factors may be different in different habitats and change with time.