Legacy and alternative halogenated flame retardants in Lake Geneva fish

Environmental Science and Pollution Research - Legacy (i.e., polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD)) and alternative halogenated flame retardants (HFRs) were...     

Introduced and cryptogenic species in Port Phillip Bay, Victoria, Australia

Port Phillip Bay (PPB) is a large (1,930 km²), temperate embayment in southern Victoria, Australia. Extensive bay-wide surveys of PPB have occurred since 1840. In 1995/1996 the Commonwealth Scientific and Industrial Research Organization (CSIRO) Centre for Research on Introduced Marine Pests (CRIMP) undertook an intensive evaluation of the region with the aims of developing a comprehensive species list of native and introduced biota and contrasting previous bay-wide assessments with a current field survey in order to detect new incursions and discern alterations to native communities. Two methods were used to meet these aims: a re-evaluation of regional museum collections and published research in PPB to identify and determine the timing of introductions; and field surveys for benthic (infauna, epifauna and encrusting) organisms between September 1995 to March 1996. One hundred and sixty introduced (99) and cryptogenic (61) species were identified representing over 13% of the recorded species of PPB. As expected, the majority of these are concentrated around the shipping ports of Geelong and Melbourne. Invasions within PPB appear to be increasing, possibly due to an increase in modern shipping traffic and an increase in aquaculture (historically associated with incidental introductions); however the records of extensive biological surveys suggest that this may, in part, be an artefact of sampling effort. In contrast to Northern Hemisphere studies, PPB (and Southern Hemisphere introductions in general) have significantly different suites of successfully invading taxa. PPB is presented as one of the most invaded marine ecosystems in the Southern Hemisphere.Communicated by M.S. Johnson, Crawley     

A comparison of different lysis buffers to assess allele dropout from single cells for preimplantation genetic diagnosis

Single cell polymerase chain reaction (PCR) for preimplantation genetic diagnosis (PGD) requires high efficiency and accuracy. Allele dropout (ADO), the random amplification failure of one of the two parental alleles, remains the most significant problem in PCR-based PGD testing since it can result in serious misdiagnosis for compound heterozygous or autosomal dominant conditions. A number of different strategies (including the use of lysis buffers to break down the cell and make the DNA accessible) have been employed to combat ADO with varying degrees of success, yet there is still no consensus among PGD centres over which lysis buffer should be used (ESHRE PGD Consortium, 1999 ). To address this issue, PCR amplification of three genes (CFTR, LAMA3 and PKP1) at different chromosomal loci was investigated. Single lymphocytes from individuals heterozygous for mutations within each of the three genes were collected and lysed in either alkaline lysis buffer (ALB) or proteinase K/SDS lysis buffer (PK). PCR amplification efficiencies were comparable between alkaline lysis and proteinase K lysis for PCR products spanning each of the three mutated loci (ΔF508 in CFTR 90% vs 88%; R650X in LAMA3 82% vs 78%; and Y71X in PKP1 91% vs 87%). While there was no appreciable difference between ADO rates between the two lysis buffers for the LAMA3 PCR product (25% vs 26%), there were significant differences in ADO rates between ALB and PK for the CFTR PCR product (0% vs 23%) and the PKP1 PCR product (8% vs 56%). Based on these results, we are currently using ALB in preference to PK/SDS buffer for the lysis of cells in clinical PGD. Copyright © 2001 John Wiley & Sons, Ltd.     

Clutch size in the swallowtail butterfly,Battus philenor: the role of host quality and egg load within and among seasonal flights in California

Summary Clutch size in the pipevine swallowtail of California (Battus philenor hirsuta) varies widely within and among two seasonal flights, early and late spring. Pilson and Rausher (1988) proposed that variation in clutch size in a Texan B. philenor population is due to assessment of host quality with subsequent adjustment of clutch size and to differences in motivational state. The assessment hypothesis and a nonexclusive alternative that clutch size is determined by mature egg load were tested for populations in Sacramento, California. Weak and sporadic correlations between host quality and clutch size were found, suggesting that host assessment with adjustment of clutch size is not a strong factor in this population. Clutch size was highly correlated to mature egg load in the early but not in the late spring flight. Yet, females from both flights had similar loads of mature eggs. It is proposed that females lay clutch sizes proportional to egg load, up to a maximum threshold. The threshold may be lowered in the late spring flight in response to changes in overall host quality or to increased egg predation, reducing both the mean clutch size and the correlation between clutch size and egg load. Potential mechanisms for the change in behavior among flights, based on changes in the threshold, are discussed.     

Prenatal diagnosis and molecular cytogenetic characterisation of a small de novo interstitial duplication 16q11.2-q13

We describe the first prenatally detected case of a small de novo interstitial duplication of chromosome 16q. This chromosomal aberration is extremely rare. Amniocentesis was indicated by advanced maternal age only. Ultrasound examinations of the foetus showed no abnormalities. Conventional and molecular cytogenetic analyses on cultured amniocytes by comparative genomic hybridisation (CGH) and fluorescence in situ hybridisation (FISH) using partial chromosome paints and a locus-specific YAC clone revealed a de novo direct duplication of the chromosomal region 16q11.2-q13 leading to a partial trisomy 16q (46,XX,dup(16)(q11.2q13)). There are only five postnatal reports of comparable duplications involving this chromosomal region. These patients presented with little or no associated dysmorphic features but with significant neurodevelopmental delay and severe behavioural problems. After genetic counselling, the parents opted for termination of pregnancy. Post-mortem examination showed slight facial dysmorphic signs, minor dysgenesis of the ovaries and an atypical outflow of the arteria thyroidea ima. Copyright © 2006 John Wiley & Sons, Ltd.     

Identifying the land use and land cover change drivers: methods and case studies of two forest reserves in Northern Benin

Environment, Development and Sustainability - Land use and land cover change (LULCC) is one of the problems that the world has been facing for the last few decades despite political attention....     

Human viral pathogens are pervasive in wastewater treatment center aerosols

Wastewater treatment center(WTC) workers may be vulnerable to diseases caused by viruses, such as the common cold, influenza and gastro-intestinal infections. Although there is a substantial body of literature characterizing the microbial community found in wastewater, only a few studies have characterized the viral component of WTC aerosols,despite the fact that most diseases affecting WTC workers are of viral origin and that some of these viruses are transmitted through the air. In this study, we evaluated in four WTCs the presence of 11 viral pathogens of particular concern in this milieu and used a metagenomic approach to characterize the total viral community in the air of one of those WTCs. The presence of viruses in aerosols in different locations of individual WTCs was evaluated and the results obtained with four commonly used air samplers were compared.We detected four of the eleven viruses tested, including human adenovirus(h Ad V),rotavirus, hepatitis A virus(HAV) and Herpes Simplex virus type 1(HSV1). The results of the metagenomic assay uncovered very few viral RNA sequences in WTC aerosols, however sequences from human DNA viruses were in much greater relative abundance.     

Dissolved and Total Copper in a Coal Ash Effluent and Receiving Stream: Assessment of In Situ Biological Effects

An in situ chemical and biological study was conducted in the lower Muskingum River (southeast Ohio, U.S.A.) to evaluate potential effects of copper (Cu) discharged from a coal ash effluent. Effluent total Cu, dissolved Cu, TSS and pH measurements were performed monthly during January-December 1995. Benthic macroinvertebrates were sampled at five river locations using artificial substrate samplers, and in situ Cu analyses were conducted. Effluent Cu (total) ranged from 8 to 142 microg L(-1) (mean = 58 microg L(-1)), but dissolved Cu never exceeded 78 microg L(-1) (mean = 20 microg L(-1)). The mean ratio of dissolved Cu to total Cu in these samples was 32%. Total Cu concentrations at the biological sampling sites adjacent to the effluent discharge were higher than levels at ambient sites, but dissolved Cu levels were similar among all sites. The macroinvertebrate community proximal to the coal ash effluent had the highest number of taxa and total number of individuals; a high number of mayfly and caddis fly taxa; and the highest Invertebrate Community Index score. The high water velocity of the discharge (which likely contained particulate organic matter) apparently created a favorable microhabitat that, combined with Cu-complexing constituents in the discharge, superceded potential adverse effects of high Cu levels. This study emphasizes the importance of instream biological data when obtained in conjunction with chemical analyses.     

Optimal Timing to Adopt an Environmental Policy in a Strategic Framework

In this paper, the problem of optimal timing, when to adopt an environmental policy in a strategic framework is considered. Using real options theory and some basic tools of game theory, we show that, under certain assumptions, a country behaving strategically should wait longer before adopting such a policy than if it behaves unstrategically or within a larger entity. Such a postponed decision is sub-optimal as regards to the environment protection.