Organophosphate dichlorvos induced dose-related differential alterations in lipid levels and lipid peroxidation in various regions of the fish brain and spinal cord

The effect of dichlorvos (DDVP) (0-0, dimethyl 2:2-dichlorovinyl phosphate), on various lipid fractions and lipid peroxidation in the discrete areas of the brain and spinal cord were studied in the fresh water teleost (Heteropneustes fossilis). Fishes were exposed to three different doses (3.0, 6.0 and 9.0 ppm) of DDVP daily for 7 days. Dose-related increase in the levels of total lipids, cholesterol and esterified fatty acids was detected in the fore brain, optic lobes, cerebellum, medulla oblongata and spinal cord. However, phospholipids were significantly decreased in the aforementioned regions of the central nervous system. The rate of lipid peroxidation was significantly increased in all the regions of the CNS.     

Pasture diversification to combat climate change impacts on grazing dairy production

Among livestock systems, grazing is likely to be most impacted by climate change because of its dependency to feed quality and availability. In order to reduce the impact of climate change on grazing livestock systems, adaptation measures should be implemented. The goal of this study is to identify the best pasture composition for a representative grazing dairy farm in Michigan in order to reduce the impacts of climate change on production. In order to achieve the goal of this study, three objectives were sought: (1) identify the best pasture composition, (2) assess economic and resource use impacts of pasture compositions under future climate scenarios, and (3) evaluate the resiliency of pasture compositions. A representative farm was developed based on a livestock practices survey and incorporated into the Integrated Farm System Model (IFSM). For the pasture compositions, four cool-season grass species and two legumes were evaluated under both current and future climate scenarios. The effectiveness of adaptation measures based on economic and resource use criteria was evaluated. Overall, the pasture composition with 50% perennial ryegrass (Lolium multiflorum) and 50% red clover (Trifolium pratense) was identified as the best. In addition, the increase in precipitation and temperature of the most intensive climate scenario could significantly improve farm net return per cow (Bos taurus) and whole farm profit while no significant impact was observed on resource use criteria. Finally, the overall sensitivity assessment showed that the most resilient pasture composition under future climate scenarios was ryegrass with red clover and the least resilient was orchardgrass (Dactylis glomerata) with white clover (Trifolium repens).     

Assessment of air pollution from small scale industry

Air pollution due to small scale industries have been found tocause serious occupational health hazards and adverse effects on vegetation and heritage. The study for air pollution impactassessment for brick kiln industries was undertaken. The stackmonitoring exercise was carried out to estimate the pollution level of SPM, SO₂, and NO_x. The ambient air quality was also measured in the vicinity of brick kilns to assess the impact of stack emission on ground level concentration. Characterisation of SPM for toxic metals were studied. Modelling exercise was carried to predict the impact of emission of brick kiln on surrounding environment. To minimise the emission level and ground level concentration, airpollution mitigation measures are suggested.     

Efficiency of pentafluorobenzyl derivative for the simultaneous determination of MCPA and its metabolites in soil

The fresh and long preservation of the stock solution of the pentafluorobenzyl bromide were applied to determine the recovery yield of MCPA, 4-chloro-o-cresol and 5-chloro-3-methylcatechol from and preserved samples. Both fresh and preserved solution of the pentafluorobenzyl bromide confirmed almost the similar effect on the derivative yield of the compounds treated with fresh/preserved samples. The overall results differed significantly within different treatments. The yield decreased only 2 % with 5-chloro-3-methylcatechol.     

The effect of age on cognitive performance under the impact of vibration in a driving environment.

The effect of organismic variable age on human cognitive performance was studied under the impact of vibration in different automobile driving environments, namely city streets, rural roads and highways. Reaction time was measured in milliseconds through a human response measurement system specifically designed for the purpose. Results of the study showed that age had a significant effect in city street and rural road conditions. It was also found that the level of equivalent acceleration of vibration and a difficulty index significantly affected cognitive performance in all driving conditions. The organismic variable age observed to have a significant effect on task performance implied that youngsters and older people are stressed differently in specific environments of driving so proper stress management strategies should be evolved for them in order to minimize the number of accidents.     

Comparison between Hansen-Hurwitz and Horvitz-Thompson estimators for adaptive cluster sampling

Thompson (1990) introduced the adaptive cluster sampling design. This sampling design has been shown to be a useful sampling method for parameter estimation of a clustered and scattered population (Roesch, 1993; Smith et al., 1995; Thompson and Seber, 1996). Two estimators, the modified Hansen-Hurwitz (HH) and Horvitz-Thompson (HT) estimators, are available to estimate the mean or total of a population. Empirical results from previous researches indicate that the modified HT estimator has smaller variance than the modified HH estimator. We analytically compare the properties of these two estimators. Some results are obtained in favor of the modified HT estimator so that practitioners are strongly recommended to use the HT estimator despite easiness of computations for the HH estimator.     

Potential Fluoride Contamination in the Drinking Water of Naranji Area, Northwest Frontier Province, Pakistan

The drinking water of Naranji village and surrounding areas of the NorthWest Frontier Province (NWFP), Pakistan, was analyzed for its fluoride content. The fluoride content of water samples from the springs in the Naranji village goes up to 13.52 mg kg(-1), which exceeds the permissible limit (1.5 mg kg(-1)) set by the World Health Organization (WHO). This study explores the source of fluoride contamination and attributes it to the alkaline rocks of the Ambela granitic complex and the Koga complex. The low-lying areas towards the south have a fluoride content within the permissible limit. The Naranji area therefore needs urgent remedial measures.     

博斯腾湖流域地下水重金属污染的人体健康风险评估

在新疆博斯腾湖流域绿洲灌区采集67个浅层地下水样品,测定其中Cu、Mn、Cd、Cr、Ni和Zn等6种重金属元素的含量,采用Nemerow综合污染指数对地下水中重金属污染程度进行评价,借助US EPA健康风险评价模型对地下水中重金属污染的潜在健康风险进行评价。结果表明:(1)地下水中各元素平均含量大小顺序依次为:MnZnCuNi CrCd,各元素平均含量均未超出国家标准的限值;(2)研究区地下水中各重金属元素单项污染指数平均值从大到小依次为:Cd(2.04)、Mn(0.69)、Ni(0.45)、Cr(0.24)、Zn(0.07)、Cu(0.03)。综合污染指数的变化范围在0.23～2.22之间,平均值为0.73,呈现轻微污染;(3)健康风险评价结果表明,地下水中6种重金属对成人的潜在非致癌健康风险HI为7.83E-011,表明暴露的个体不太可能有明显的不良健康影响;对儿童的潜在非致癌健康风险HI为1.05E+011,表明研究区地下水重金属可能对当地儿童的健康产生不利影响,有进一步研究的必要性。     

Seasonal variations of chlorophyll-a in Demirdöven Dam Reservoir (Erzurum, Turkey) in relation to phytoplankton density and environmental factors

The seasonal variations of Chlorophyll-a was examined in relation to phytoplankton density and physico-chemical factors in Demird?ven Dam Reservoir during 2000-2001. Chlorophyll-a concentrations ranged from 0.62 to 7.19 mg/m3 and from 0.67 to 8.88 mg/m3 in 2000 and 2001, respectively. Maximum Chlorophyll-a concentrations were found near the metalimnion and decreased with depth. Chlorophyll-a concentrations showed positive correlation to phytoplankton density, water temperature and nutrient concentrations, and negative correlations to Secchi depth. Demird?ven Dam Reservoir can be classified as a mesotrophic reservoir according to Chlorophyll-a concentrations.     

PERSISTENT CONFLICTS OVER TIMBER PRODUCTION AND WATERSHED MANAGEMENP: A PROBLEM ANALYSIS1

ABSTRACT: Most forest lands are managed for multiple purposes, among them timber production and water supply. Conflicts often arise in such cases because logging is perceived as a threat to water quality. These conflicts can result from uncertain factual information, from differences in underlying social values, or from imbalances in the incidence of costs and benefits. Resulting conificts may go unresolved because existing institutional structures fail to address the real roots of the dispute. When such conificts go unresolved, benefits are often lost, and social, political, and managerial costs are high. This study found that the roots of conifict may lie in value differences or in interest impacts, but attention may be focused inappropriately and unproductively on factual issues. It suggests that at least some long-standing disputes in the management of forested watersheds may be resolved by identifying the root causes of these disputes and choosing those actions, whether they be changes in management guidelines or altered institutional structures, which are appropriate to those causes.