Arsenic tissue concentration of immature mice one hour after oral exposure to gold mine tailings

A potentially high bioavailability of arsenic in gold mine tailings from a site in northern California has been suggested by solubility studies. To help address this issue, an in vivo dosing study was conducted using 12dayold Swiss Webster mouse pups (n=8/group). A sample of sizefractionated mine tailings from the site (<20m particle size, 691g g^–1 arsenic) was prepared as an aqueous suspension and administered by gavage in a volume that provided 4mg As/kg body weight. The control group received the same volume of a commercial soil (1g g^–1 As) of similar particle size (<60m). No mortality or toxic signs were noted in either group. Tissue samples were collected 1h after gavage, freezedried, microwavedigested and analysed for arsenic by ICP/MS (detection limit 2ng As g^–1 dry weight). Arsenic concentrations (ng As g^–1 dry weight) in tissues from the pups who received mine tailings were significantly higher than in control tissues. The mean elevation in arsenic concentration was highest in the liver (3364% of control, p<0.0001), followed by blood (818 of control, p<0.0001), skin (207% of control, p=0.07), and brain (143% of control, p<0.0001). The carcass arsenic concentration (excluding the GI tract, liver, brain and skin) was 138 of control (p=0.02). The data indicate uptake of arsenic from weathered mine tailings by the immature mouse pups after oral exposure.     

Reproductive activities in the sesarmid crab Sesarma intermedia in the coastal and estuarine habitats of Hakata,Japan

Aspects of activity pattern, mating, breeding behaviour and reproductive organs were studied in Sesarma intermedia (de Hann) along the Tatara river estuary, Hakata Bay, western Japan. Activity started from early May after a six-month hibernation period. The daily activity pattern was bimodal with one peak after sunset and another before sunrise. Mating started after emerging from hibernation and was ended by July. Practically no mating was seen in August and thereafter, by which time most of the females were carrying eggs. Larger males mated more frequently with any sized adult female. Copulation seemed to take place both in the burrow and on the surface of natural shelter. Females began to carry eggs from mid June on the estuarine habitat, whereas on the coastal habitat ovigerous females could be seen from mid-May. Multiple ovipositions of eggs were realized. Females were able to oviposit three times without any repeated mating. It took about 30 d to incubate one egg mass and less than one week to spawn again. The release of larvae was not sporadic but rather took place within a limited time interval. Sunset seemed to have a great influence on larvae release along the seashore. Energy allocation for reproductive purposes seemed to start before crabs awoke from the hibernation period. Towards the end of the breeding period there was a drastic decline in ovarian development with a remarkable gain in hepatopancreas, a reservoir for energy.     

Life on the Edge: Vulnerability and Adaptation of African Ecosystems to Global Climate Change

Donor countriesare providing financial and technicalsupport for global climate change countrystudies to help African nations meet theirreporting needs under the United NationsFramework Convention on Climate Change(UNFCCC). Technical assistance to completevulnerability and adaptation assessmentsincludes training of analysts, sharing ofcontemporary tools (e.g. simulationmodels), data and assessment techniques,information-sharing workshops and aninternational exchange programme foranalysts. This chapter summarizes 14African country studies (Botswana, Côted'Ivoire, Egypt, Ethiopia, the Gambia,Kenya, Malawi, Mauritius, Nigeria, SouthAfrica, Tanzania, Uganda, Zambia andZimbabwe) assessing vulnerabilities toglobal climate change and identifyingadaptation options. The analysis revealedthat the participating African countriesare vulnerable to global climate change inmore than one of the followingsocio-economic sectors: coastal resources,agriculture, grasslands and livestock,water resources, forests, wildlife, andhuman health. This vulnerability isexacerbated by widespread poverty,recurrent droughts, inequitable landdistribution, environmental degradation,natural resource mismanagement anddependence on rain-fed agriculture. Arange of practical adaptation options wereidentified in key socio-economic sectors ofthe African nations analysed. However,underdeveloped human and institutionalcapacity, as well as the absence ofadequate infrastructure, renders manytraditional coping strategies (rooted inpolitical and economic stability)ineffective or insufficient. FutureAfrican country studies should be moreclosely coordinated with development ofnational climate change action plans     

Prenatal exclusion of haemophilia a and carrier testing by direct detection of a disease lesion

A novel mutation was detected in the Factor VIII gene of a sporadic case of severe haemophilia A. The lesion, a CGA → TGA transition, converts Arg 795 to Term and adequately accounts for the severe phenotype observed. PCR/direct sequencing was used to confirm the carrier status in the mother. Exclusion of haemophilia A in an at-risk pregnancy was then achieved by demonstration of the absence of this lesion in fetal DNA from a chorionic villus sample. The mutation was also detectable by chemical cleavage of mismatch (CCM), which both confirmed the prenatal diagnosis and established the carrier status of the proband's sister. This example therefore serves to illustrate the potential of direct gene analysis in sporadic cases of haemophilia A and/or in families uninformative for known RFLPs.     

Impacts of weathered tire debris on the development of Rana sylvatica larvae

Highway runoff has the potential to negatively impact receiving systems including stormwater retention ponds where highway particulate matter can accumulate following runoff events. Tire wear particles, which contain about 1% Zn by mass, make up approximately one-third of the vehicle derived particulates in highway runoff and therefore may serve as a stressor to organisms utilizing retention ponds as habitat. In this study, we focused on the potential contribution of tire debris to Zn accumulation by Rana sylvatica larvae and possible lethal or sublethal impacts resulting from exposure to weathered tire debris during development. Eggs and larvae were exposed to aged sediments (containing either ZnCl2 or tire particulate matter, both providing nominal concentrations of 1000 mg Zn kg(-1)) through metamorphosis. Water column Zn was elevated in both the ZnCl2 and tire treatments relative to the control treatment, indicating that aging allowed Zn leaching from tire debris to occur. Tissue Zn was also elevated for the ZnCl2 and tire treatments indicating that Zn in the treatments was available for uptake by the amphibians. Exposure to both ZnCl2 and tire treatments increased the time for larvae to complete metamorphosis in comparison with controls. We also observed that the longer the organisms took to complete metamorphosis, the smaller their mass at metamorphosis. Our results indicate that Zn leached from aged tire debris is bioavailable to developing R. sylvatica larvae and that exposure to tire debris amended sediments can result in measurable physiological outcomes to wood frogs that may influence population dynamics.     

Biochemical responses in armored catfish (Pterygoplichthys anisitsi) after short-term exposure to diesel oil,pure biodiesel and biodiesel blends

Biodiesel fuel is gradually replacing petroleum-based diesel oil use. Despite the biodiesel being considered friendlier to the environment, little is known about its effects in aquatic organisms. In this work we evaluated whether biodiesel exposure can affect oxidative stress parameters and biotransformation enzymes in armored catfish (Pterygoplichthys anisitsi, Loricariidae), a South American endemic species. Thus, fish were exposed for 2 and 7 d to 0.01 mL L⁻¹ and 0.1 mL L⁻¹ of pure diesel, pure biodiesel (B100) and blends of diesel with 5% (B5) and 20% (B20) biodiesel. Lipid peroxidation (malondialdehyde) levels and the activities of the enzymes glutathione S-transferase, superoxide dismutase, catalase and glutathione peroxidase were measured in liver and gills. Also, DNA damage (8-oxo-7, 8-dihydro-2′-deoxyguanosine) levels in gills and 7-ethoxyresorufin-O-deethylase activity in liver were assessed. Pure diesel, B5 and B20 blends changed most of the enzymes tested and in some cases, B5 and B20 induced a higher enzyme activity than pure diesel. Antioxidant system activation in P. anisitsi was effective to counteract reactive oxygen species effects, since DNA damage and lipid peroxidation levels were maintained at basal levels after all treatments. However, fish gills exposed to B20 and B100 presented increased lipid peroxidation. Despite biodiesel being more biodegradable fuel that emits less greenhouse gases, the increased lipid peroxidation showed that biofuel and its blends also represent hazards to aquatic biota.     

An evaluation of indoor and outdoor biological particulate matter

The incidences of allergies, allergic diseases and asthma are increasing world wide. Global climate change is likely to impact plants and animals, as well as microorganisms. The World Health Organization, U.S. Environmental Protection Agency, U.S. Department of Agriculture, U.S. Department of Health and Human Services, and the Intergovernmental Panel on Climate Change cite increased allergic reactions due to climate change as a growing concern. Monitoring of indoor and ambient particulate matter (PM) and the characterization of the content for biological aerosol concentrations has not been extensively performed. Samples from urban and rural North Carolina (NC), and Denver (CO), were collected and analyzed as the goal of this research. A study of PM₁₀ (<10 μm in aerodynamic diameter) and PM_2.5 (<2.5 μm in aerodynamic diameter) fractions of ambient bioaerosols was undertaken for a six month period to evaluate the potential for long-term concentrations. These airborne bioaerosols can induce irritational, allergic, infectious, and chemical responses in exposed individuals. Three separate sites were monitored, samples were collected and analyzed for mass and biological content (endotoxins, (1,3)-β-d-glucan and protein). Concentrations of these bioaerosols were reported as a function of PM size fraction, mass and volume of air sampled. The results indicated that higher concentrations of biologicals were present in PM₁₀ than were present in PM_2.5, except when near-roadway conditions existed. This study provides the characterization of ambient bioaerosol concentrations in a variety of areas and conditions.     

Commitment,procedural fairness,and organizational citizenship behavior: a multifoci analysis

Research on commitment, procedural fairness, and organizational citizenship behavior (OCB) suggests that employees maintain distinct beliefs about, and direct behaviors towards, multiple targets in the workplace (e.g., the organization as a whole, their supervisor, and fellow workgroup members). The present studies were designed to test for “target similarity effects,” in which the relationships between commitment, procedural fairness, and OCB were expected to be stronger when they referred to the same target than when they referred to different targets. As predicted, we found that: (1) the positive relationship between commitment and OCB, and (2) the mediating effect of commitment on the positive relationship between procedural fairness and OCB, was particularly likely to emerge when the constructs were in reference to the same target. Support for these target similarity effects was found among layoff survivors (Study 1) and student project teams (Study 2). Theoretical and practical implications are discussed, as are limitations of the studies and suggestions for future research. Copyright © 2008 John Wiley & Sons, Ltd.     

Taproot™ technology: Tree coring for fast,noninvasive plume delineations

In efforts to evaluate the use of plants as a forensic tool for delineating contaminated soil and groundwater, a laboratory experiment and a field sampling effort were undertaken. Site assessments are often costly and inaccurate, requiring multiple mobilizations to hone in on source areas and getting accurate estimates of contaminant extent and distribution. As these extensive site delineations take place, valuable time and resources are lost. The findings of this study show that plants can be used as a tool to evaluate a variety of subsurface contaminants, either in the vadose zone or in the saturated zone. In the first field application of Taproot? Technology, a large, heavily forested site was sampled in one day and the contamination on‐site was more accurately delineated than had been generated at the site in over a decade, with more than 26 wells installed. New source zones were detected on the site, and the presence of new waste depositions was uncovered for the first time showing the great value of tree coring as a contaminant detection tool. © 2009 Wiley Periodicals, Inc.