地下水铀污染的原位微生物还原与固定:在美国能源部田纳西橡树岭放射物污染现场的试验

总结了美国斯坦福大学和橡树岭国家实验室等在美国能源部田纳西州橡树岭综合试验基地进行的铀污染原位微生物修复阶段性试验结果.本试验利用微生物以乙醇为电子供体还原地下水和沉积物中的六价铀为不溶解的四价铀,使之原位固定化.随后通过加入溶解氧和硝酸盐来试验微生物还原后的地下水层中还原固定态铀的稳定性.通过预处理和长期间隔注入乙醇...     

Development and applications of functional gene microarrays in the analysis of the functional diversity, composition, and structure of microbial communities

Functional gene arrays (FGAs) are a special type of microarrays containing probes for key genes involved in microbial functional processes, such as biogeochemical cycling of carbon, nitrogen, sulfur, phosphorus, and metals, biodegradation of environmental contaminants, energy processing, and stress responses. GeoChips are considered as the most comprehensive FGAs. Experimentally established probe design criteria and a computational pipeline integrating sequence retrieval, probe design and verification, array construction, data analysis, and automatic update are used to develop the GeoChip technology. GeoChip has been systematically evaluated and demonstrated to be a powerful tool for rapid, specific, sensitive, and quantitative analysis of microbial communities in a high-throughput manner. Several generations of GeoChip have been developed and applied to investigate the functional diversity, composition, structure, function, and dynamics of a variety of microbial communities from different habitats, such as water, soil, marine, bioreactor, human microbiome, and extreme ecosystems. GeoChip is able to address fundamental questions related to global change, bioenergy, bioremediation, agricultural operation, land use, human health, environmental restoration, and ecological theories and to link the microbial community structure to environmental factors and ecosystem functioning.     

The importance of gender in mid-career: A longitudinal study of MBAs

This longitudinal study investigates whether the work environment in mid-career is comparable for men and women MBAs. No gender differences were found in early career. However by mid-career, women report less income, career satisfaction, and boss appreciation than men. Discrimination is also more prevalent for women.     

Biomonitoring insecticide pollution using non-target soil microarthropods

The scope of biomonitoring insecticide pollution in soil is discussed with the help of field and laboratory findings on the density, prey-predator ratio and fecundity of non-target microarthropod fauna. Field experiments were conducted in small plots with mustard, wheat and lady's finger crops and insecticides namely heptachlor 20EC (3.25 kg ai/ha = 16.25 lit/ha) and endosulfan 35EC (0.875 kg ai/ha = 2.5 lit/ha) applied at the seedling stages. Soil microarthropod population estimated at fortnightly intervals in the treated and untreated control plots revealed a general trend of adverse effect of the insecticides, prominently on the density and relative abundance of major prey groups like Collembola and Acari leading to notable decline in prey-predator ratio. Comparison of the percentage reductions of major taxonomic and trophic groups between pre-treatment and post-treatment intervals also demonstrated the ill effect of both heptachlor and endosulfan, notably on Collembola and the prey category. In the laboratory the survival success and fecundity of Cyphoderus javanus (Collembola) and Archegozetes longisetosus (Acari) were compared by exposing freshly emerged adults to sub-lethal concentrations of heptachlor and endosulfan for varying durations. The untreated control sets recorded high fecundity for both C. javanus and A. longisetosus, but chronic toxicity of the insecticides on adults confined to the treated soil resulted into very low fecundity. Even short duration exposure to heptachlor and endosulfan treated soil for 24 or 72 hours only was found to delay the egg-laying and decrease the fecundity of both the species. It is concluded that population responses and reproductive sensitivity in non-target soil microarthropods are potential eco-toxicological parameters for detecting pesticide pollution in soil and for ecological health assessment since the results are based on the bioactivity of toxicants.     

Sustainable Agriculture in the UK

Most agricultural assessments of global environmental change made to date have not focused explicitly on sustainability issues, and have neglected the considerable impacts of shifting agricultural zones, alterations in commercial fertiliser and pesticide use, and changes in the demand for water resources. The current crisis in agriculture, with its economic, political, social and ecological dimensions, has arisen because of the pursuit of a productivity technology/policy model. This broad policy of agricultural ‘modernisation’ and development through the application of agricultural science and technology has shaped the direction of technological change in agriculture and the evolution of a complex agro-industrial food system.¹ This paper focuses on England’s Rural Development Programme² as it contributes to sustainable agriculture alongside the control of pollution.Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Exploring the potential of otolith microchemistry to enhance diet analysis in pinnipeds

Increasing the scope and accuracy of information about pinniped diets obtainable from non-invasive techniques is increasingly important, particularly in cases where pinniped species are threatened or endangered. This study is the first to explore the potential for using elemental analysis of the otoliths found in scat to enhance the information available for diet analyses. We investigated the effects of pinniped digestion on otolith microchemistry using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). We compared the elements contained in the edges (adult stage) and cores (larval/juvenile stage) of otoliths from Pacific herring (Clupea pallasii), Atka mackerel (Pleurogrammus monopterygius), and Walleye pollock (Theragra chalcogramma) recovered from the scat of captive Steller sea lions (Eumetopias jubatus) to elements in a sample of pristine (undigested) otoliths. We found that digestion had a significant effect on four of the six sampled combinations of species and otolith region (herring edges and cores, mackerel edges, and pollock cores), and that Rb most frequently showed significant differences in concentration after digestion. We could significantly discriminate among species of both pristine and digested otoliths using either otolith edges or cores with the elements Ba, Rb, Sr, Y, and Mg. When compared to previously identified digested otoliths, unknown samples of the three species of digested otoliths could be discriminated with 55–100% accuracy depending on species and otolith region. When compared to a library of previously identified pristine and digested otoliths, unknown samples of digested otoliths could be discriminated to species with 65–88% accuracy. When the group of unknown digested otoliths was compared to known pristine otoliths, discrimination ranged from 45 to 65%. These results indicate that elemental analysis could be used to supplement visual identification of otoliths from scat. However, further research is required to determine whether elemental analysis of digested otoliths could be useful for prey fish population studies.     

Does the Harvard/U.S. Environmental Protection Agency Ambient Particle Concentrator Change the Toxic Potential of Particles?

Abstract

Inhalation exposure to urban air particles is known to increase morbidity in humans and animals. Our group utilizes the Harvard/U.S. Environmental Protection Agency Ambient Particle Concentrator (HAPC) to generate concentrated aerosols of outdoor air particles for experimental exposures. We have reported increased pathologic responses to inhalation of concentrated urban air particles and identified silicon (as silicate) as an element associated with many of these responses. Using silicate-rich Mt. St. Helen’s volcanic ash (MSHA), we exposed three groups of Sprague-Dawley rats by inhalation for 6 hr to filtered air, MSHA, or MSHA passed though the HAPC. Twenty-four hours following exposure, bronchoalveolar lavage was performed to assess total cell count, differential cell count, protein, lactate dehydrogenase, and n-β[notdef]glucosaminidase levels. Peripheral blood was examined for packed cell volume, total protein, total white cells, and differential cell count. Morphologic studies localized particles in the lung and assessed pulmonary vasculature. No significant differences were observed among any of the groups in any parameter measured including morpho-metric analysis of pulmonary vasoconstriction. Scanning electron microscopy and X-ray analysis identified particles as silicates typical of MSHA throughout the lung. These findings suggest that particles passing through the HAPC have no change in their toxic potential in an exposure setting where particle deposition in the lung has occurred.     

Regulatory impediments to carbon emission mitigation in Sub-Saharan Africa: the impact of a hostile business environment and high tax burden

Environmental Science and Pollution Research - Sub-Saharan Africa’s regulatory environment ranks amongst the least business friendly in the world. The difficulty of starting and operating...     

Preimplantation genetic diagnostic protocols for α- and β-thalassaemias using multiplex fluorescent PCR

Haemoglobinopathies including α- and β-thalassaemia are the world's most common class of single gene disorder. Prenatal diagnosis (PND) for β-thalassaemia has been proven to be an effective strategy for controlling the incidence of new cases and is widely used in several countries where the disease is common. Successful preimplantation genetic diagnosis (PGD) protocols for β-thalassaemia have been introduced using restriction fragment length polymorphism (RFLP), single-stranded conformation polymorphism (SSCP) and denaturing gradient gel electrophoresis (DGGE). However, contamination and allele dropout (ADO) remain an important concern for all of these strategies. In the present study two PGD protocols for detecting β-thalassaemia mutations (codon 41-42 and IVSI-110) and one for α-thalassaemia (SEA mutation) have been designed and tested. These methods contain failsafe mechanisms to reduce the risk of misdiagnosis due to ADO or contamination and utilise multiplex fluorescent PCR (F-PCR). Interestingly, amplification efficiency and ADO were significantly affected by the choice of DNA polymerase and the freshness of the single cells used. The close similarity between the DNA sequences of β-globin and δ-globin was also found to be an important issue that necessitated careful design of primers for the β-globin gene. Copyright © 2001 John Wiley & Sons, Ltd.