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.     

Activation of waste MDF sawdust charcoal and its reactive dye adsorption characteristics

This paper reports an experimental investigation of converting waste medium density fibreboard (MDF) sawdust into chars and activated carbon using chemical activation and thermal carbonisation processes. The MDF sawdust generated during the production of architectural mouldings was characterised and found to have unique properties in terms of fine particle size and high particle density. It also has a high content of urea formaldehyde resin used as a binder in the manufacturing of MDF board. Direct thermal carbonisation and chemical activation of the sawdust by metal impregnation and acid (phosphoric acid) treatment prior to pyrolysis treatment were carried out. The surface morphology of the raw dust, its chars and activated carbon were examined using scanning electron microscopy (SEM). Adsorptive properties and total pore volume of the materials were also analysed using the BET nitrogen adsorption method. Liquid adsorption of a reactive dye (Levafix Brilliant red E-4BA) by the derived sawdust carbon was investigated in batch isothermal adsorption process and the results compared to adsorption on to a commercial activated carbon (Filtrasorb F400). The MDF sawdust carbon exhibited in general a very low adsorption capacity towards the reactive dye, and physical characterisation of the carbon revealed that the conventional chemical activation and thermal carbonisation process were ineffective in developing a microporous structure in the dust particles. The small size of the powdery dust, the high particle density, and the presence of the urea formaldehyde resin all contributed to the difficulty of developing a proper porous structure during the thermal and chemical activation process. Finally, activation of the dust material in a consolidated form (cylindrical pellet) only achieved very limited improvement in the dye adsorption capacity. This original study, reporting some unexpected outcomes, may serve as a stepping-stone for future investigations of recycle and reuse of the waste MDF sawdust which is becoming an increasing environmental and cost liability.     

Females prefer carotenoid colored males as mates in the pentamorphic livebearing fish,<Emphasis Type="Italic"> Poecilia parae</Emphasis>

The first results of female preference and chosen male mating success in a new model organism, the pentamorphic livebearing fish, Poecilia parae, are presented. Poecilia parae is a relative of the guppy, P. reticulata, and is assumed to have similar reproductive behavior. We tested the hypothesis that P. parae females, like female guppies, prefer caretenoid colored males as mates. Here we show that the time a female spent with males was significantly greater for carotenoid coloration in red and yellow melanzona, but time with these two morphs did not differ. The preferred red and yellow males mated significantly more often with their choosing females than did the non-preferred blue and parae males. The few blue melanzona and parae males that mated did so without performing courtship displays. Some females mated with all phenotypes including immaculata males during open group trials. Female P. parae clearly preferred males with carotenoid coloration, thereby corroborating the hypothesis. Alternative male mating tactics by blue melanzona, parae, and immaculata morphs and promiscuous mating by females also resembled features of reproductive behaviors exhibited by guppies.     

Fear,victimization, and stress among urban public school teachers

Data from the National Institute of Education's Safe School Study Report suggested that teachers in American urban public schools are emotionally and physically victimized and that the result is heightened level of stress associated with teaching. This study, which is part of larger, longitudinal project, explores the linkages between reported experiences of victimization by 291 urban public school teachers and task-specific stressors in the performance of the teaching role. The level of reported stress and nature and degree of victimization differ by the grade level taught and the race of the teacher. Generally, minority teachers (black and brown) are less likely to report being stressed or victimized than are white teachers, while elementary school teachers report their work to be most stressful. There is no evidence of a specific causal ordering between fear of victimization and teacher stress. Rather, each may feed upon and facilitate the other.     

Pollutant source identification and allocation: Advances in hydrocarbon fingerprinting

Often liability for environmental damage and cleanup of contaminated sites is made difficult, especially with chemically complex environments containing different pollutants, by the inability to differentiate potential sources (or “owners”) of pollutants from each other. As a result, unnecessary costs may be associated with having to assume financial responsibility for alleged contamination of a site. This article reviews the advances in chemical fingerprinting as a tool in identifying and differentiating sources of hydrocarbon pollutants in chemically complex environments. Appropriate hydrocarbon target analytes and required analytical methods for hydrocarbon fingerprinting are discussed, and new interpretative tools are presented that may be applied to contaminated soil, sediment, and groundwater environmental situations. With these analytical and interpretative techniques, an appropriate allocation of chemical contamination and costs at a site can be made.     

ASSESSMENT OF GULLY-CONTROL STRUCTURES IN THE RIO NUTRIA WATERSHED,ZUNI RESERVATION,NEW MEXICO1

ABSTRACT: During the latter part of the 19th century and the early part of the 20th century, a major cycle of erosion, arroyo cutting, and gullying occurred in the southwestern United States. Since this erosion cycle began, many projects to control erosion, such as the Civilian Conservation Corps projects in the 1930s, were initiated. However, in the Southwestern United States few studies have documented the effect of these structures in reducing erosion or their effect on gully systems. As part of a watershed rehabilitation project on the Zuni Reservation, New Mexico, 47 structures made either of earth or rocks and 23 rock and brush structures were assessed. Sixty percent of the 47 earth or rock structures have breached and relative to dam height, 65 percent of 47 structures are more than 50 percent silted. Of the 23 rock and brush structures, 22 percent have breached or are close to breaching. Reasons for breaching of all structural types may be piping, scour immediately below the structures, large runoff and large drainage area, poor maintenance, headcutting, and active arroyo deepening and widening. In most cases, documentation does not exist on structure design, the specific purpose for a structure, or when these structures were built.     

A review of models for estimating terrestrial ecological receptor exposure to chemical contaminants

In instances where empirical measurements are not practicable, ecological risk assessments may rely on site-specific exposure models for estimating uptake of chemical contaminants. This paper presents, based on a review of the literature, a compilation of relatively simple quantitative models that can be combined to produce site- and species-specific first-order estimates of uptake of chemicals from abiotic media. These models have proved useful in providing order-of-magnitude estimates for screening and sample program design purposes. This paper intended as both a practical guide for choosing models to estimate terrestrial wildlife exposures and as a step toward development of a more comprehensive and standard approach to exposure assessment in terrestrial ecological receptors.