Effects of aging and sediment composition on hexachlorobenzene desorption resistance compared to oral bioavailability in rats

Studies were conducted to assess the effects of black carbon, clay type and aging (1-1.5yr) on desorption and bioavailability of hexachlorobenzene (HCB) in spiked artificial sediments. Tenax (a super sorbent)-mediated desorption was used to examine the effects of these parameters on the physicochemical availability of HCB. The Tenax-mediated desorption of HCB from the four aged artificial sediments exhibited biphasic kinetics. The fast desorbing fractions ranged from 64.8% to 22.3%, showing reductions of 4.0-18.9% compared with freshly-spiked sediments. Statistical analysis on the fast desorbing fractions showed that all three treatment effects (i.e., montmorillonite clay, black carbon content, and aging) were significant. Two sediments with higher black carbon content exhibited much greater aging effects (i.e., greater reduction in fast desorbing fraction) than the other two sediments without the addition of black carbon. For both freshly-spiked and aged sediments, the desorption resistant sediment-bound HCB (i.e., slow desorbing fraction) correlated reasonably well to previously reported rat fecal elimination of HCB, which is a measure of the non-bioavailable fraction of sediment-bound HCB. A similar correlation was also observed between fast desorbing fraction and previously reported accumulation of HCB in the rat body (carcass+skin). These observations suggest that physicochemical availability, as defined by the desorption of HCB from sediments, provides a reasonable prediction of the oral bioavailability of sediment-bound HCB to rats. These results showed that montmorillonite clay, black carbon and aging reduced physicochemical availability and ultimately bioavailability of sediment-bound HCB.     

In vitro metabolism of deltamethrin by stem and leaf homogenates of tobacco plants

Stem and leaf homogenates from tobacco plants metabolised deltamethrin by oxidative and hydrolytic actions on the insecticide. Although a major portion of deltamethrin remained unchanged, metabolites such as 3-phenoxybenzaldehyde, 3-phenoxybenzoic acid and 3-(2,2-dibromonyl)-2,2-dimethylcyclopropanecarboxylic acid were formed. The data suggest a major portion of the insecticide would remain unchanged when absorbed by tobacco plants.     

How transformational leadership influences follower helping behavior: The role of trust and prosocial motivation

We proposed and tested a moderated mediation model that jointly examines affect‐based and cognition‐based trust as the mediators and prosocial motivation as the moderator in relationships between transformational leadership and followers’ helping behavior towards coworkers. Data were collected from 348 sales and servicing employees and their supervisors in four private retail companies and five private manufacturing companies located in Southeast China. The results showed that both affect‐based trust and cognition‐based trust mediated the relationship between transformational leadership and followers’ helping behavior towards coworkers. Furthermore, moderated mediation analyses showed that affect‐based trust mediated the relationship between transformational leadership and followers’ helping behavior towards coworkers only among employees with high prosocial motivation, whereas cognition‐based trust mediated this relationship among only those with low prosocial motivation. Implications for the theory and practice of leadership are then discussed. Copyright © 2013 John Wiley & Sons, Ltd.     

Genetic connectivity and historical demography of the blue barred parrotfish (Scarus ghobban) in the western Indian Ocean

Studies on genetic connectivity are essential for the design of management strategies for coral reef fisheries. In this study we used a mitochondrial DNA marker to investigate population structure of the reef-associated parrotfish, Scarus ghobban, from four countries, Kenya, Mauritius, Seychelles and Tanzania, in the western Indian Ocean. We obtained nucleotide sequences of the mitochondrial control region for 117 individuals. Measures of haplotype diversity were relatively high. Pairwise population differentiation (F _ST) was low, but not always non-significant. Analysis of molecular variance (AMOVA) showed genetic differentiation between groups, when the data was partitioned into two groups consisting of samples from Mauritius and Tanzania in one group, and samples from Kenya and Seychelles in another group. Direction of gene flow was estimated using a Bayesian approach. Migration was sometimes asymmetric or directional, coinciding with the flow of major oceanic and coastal currents in the region. Mismatch distributions, based on the observed number of differences among haplotype pairs, produced a unimodal distribution, indicative of recent demographic expansion. Phylogenetic analyses revealed three clades without any geographic structure, suggesting recent migration between historically isolated lineages. We reconstructed the historical demography of S. ghobban and examined it in the context of Pleistocene climate stages and changes in relative sea level. Overall, these results showed that populations of S. ghobban are genetically diverse and have relatively high gene flow, with some genetic structuring in the western Indian Ocean.     

Sequential participation of glutathione and sulph-hydryl(s) in reductive dechlorination of 2,4-di-, and 2,4,5-trichloro phenacyl chlorides by soluble fraction (105,000 x g) of chicken liver homogenate.

The mode of reductive dechlorination of alpha-chloroacetophenones, 2,4-di-, and 2,4,5-trichloro phenacyl chlorides into respective acetophenone by soluble fraction (105,000 x g) from chicken liver homogenate has been investigated. The transformation involved the sequential participation of glutathione and a sulph-hydryl. The phenacyl chloride first reacted with glutathione to yield the phenacyl glutathione, which in turn, in the presence of a sulph-hydryl, was reduced enzymatically to produce the ketone, probably via a disulfide intermediate.     

Assessment of cobalt in wheat grains as affected by diverse fertilizers: implications for public health

Environmental Science and Pollution Research - Present study was conducted to check the heavy metal content in wheat treated with municipal solid waste, Although municipal solid waste was enriched...     

Multifaceted role of natural sources for COVID-19 pandemic as marine drugs

Environmental Science and Pollution Research - COVID-19, which is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has quickly spread over the world, posing a...     

Correction to: Multifaceted role of natural sources for COVID-19 pandemic as marine drugs

Environmental Science and Pollution Research -     

Evaluation of nickel toxicity in wheat as function of diverse type of fertilizers: implications for public health

Environmental Science and Pollution Research - Many studies have described the physiological, biochemical, and molecular responses to heavy metal toxicity and deficiencies individually in plants....