Indian Ministry of Environment and Forests

About: Indian Ministry of Environment and Forests is a government organization based out in New Delhi, India. It is known for research contribution in the topics: Population & Climate change. The organization has 3731 authors who have published 3782 publications receiving 85717 citations.

Bifenthrin-induced neurotoxicity in rats: involvement of oxidative stress

Abstract: Extensive use of synthetic pyrethroids has resulted in serious human health issues. Induction of oxidative stress is an important mechanism of action of most pesticides including pyrethroids. In the present study, we have elucidated the possible role of oxidative stress in bifenthrin-induced neurotoxicity. Adult male Wistar rats were administered bifenthrin (3.5 and 7 mg per kg body weight p.o.) for 30 days. Behavioral studies were conducted on a set of randomly selected rats from each treatment group after completion of treatment. Neurochemical parameters were assessed 24 h after the last dose was administered. The selected behavioral and neurochemical endpoints were also assessed 15 days after cessation of exposure to reveal whether the neurobehavioral changes produced by bifenthrin were temporary or permanent. Deficits in motor activity, motor incoordination, and cognitive impairment were observed after exposure to bifenthrin. Levels of biogenic amines viz. dopamine (DA) and its metabolites, i.e. 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), epinephrine (EPN), norepinephrine (NE), and serotonin (5-HT) altered in the frontal cortex, corpus striatum, and hippocampus of bifenthrin-treated rats. A decrease in the activity of acetylcholinesterase (AChE) occurred in all regions of the brain. Both doses of bifenthrin significantly induced lipid peroxidation (LPO) and increased protein carbonyl levels in the frontal cortex, corpus striatum, and hippocampus of rats. The activities of antioxidant enzymes, i.e. catalase, superoxide dismutase, and glutathione peroxidase, were also suppressed in all selected regions of the brain. A trend of recovery was, however, observed in all the behavioral and neurochemical endpoints 15 days after withdrawal of exposure. Oxidative stress seems to play an important role in bifenthrin-induced neurotoxicity. Our study suggests that long-term exposure to these compounds can produce detrimental effects.

Influence of phenology on site selection by female American black bears in coastal British Columbia

Abstract: We examined factors that affect site selection by female American black bears (Ursus americanus) in coastal British Columbia, Canada, 1992-95. We monitored 9 radiocollared females and compared sites that were selected within their home ranges to those that were not selected using 1-1 matched logistic regression procedures. We used information-theoretic inference to assess the effect of 19 habitat, temporal, and spatial variables in 27 candidate models to explain selection of sites within home ranges. The model that best explained site selection was 50 times more likely to be the best model, given the data, than the second-best model. The best model suggested that the probability that a site would be used by female black bears increased with increasing values of phenologically adjusted berry value interacting with light levels, phenologically adjusted succulent forage value, and forest harvesting. Probability of use decreased with increasing distance from streams dependent upon salmon (Oncorhynchus spp.) availability and increasing distance from low-traffic roads. Although the best model included horizontal visibility and distance to high-traffic roads as variables, these factors had undetermined effects on the probability of use (95% confidence interval of odds ratio encompassed 1). Including phenological adjustments for abundance of berries and succulent foods greatly increased the support for the models by the data, compared to models based on cover of food plants alone. These results confirm that bears are cognizant of both temporal and spatial differences in food availability and that they modify their selection of sites based on these differences. Our results imply that site selection by female black bears involved a complex set of decisions about not only food availability, but also disturbance by humans. To increase the compatibility of timber production with conservation of black bear habitat, managers need to consider the spatial and temporal effects of the creation of food-rich openings and different types of roads on the suitability and effectiveness of habitats to support black bears.

Establishment, management, and maintenance of the phoenix islands protected area.

Abstract: The Republic of Kiribati's Phoenix Islands Protected Area (PIPA), located in the equatorial central Pacific, is the largest and deepest UNESCO World Heritage site on earth. Created in 2008, it was the first Marine Protected Area (MPA) of its kind (at the time of inception, the largest in the world) and includes eight low-lying islands, shallow coral reefs, submerged shallow and deep seamounts and extensive open-ocean and ocean floor habitat. Due to their isolation, the shallow reef habitats have been protected de facto from severe exploitation, though the surrounding waters have been continually fished for large pelagics and whales over many decades. PIPA was created under a partnership between the Government of Kiribati and the international non-governmental organizations-Conservation International and the New England Aquarium. PIPA has a unique conservation strategy as the first marine MPA to use a conservation contract mechanism with a corresponding Conservation Trust established to be both a sustainable financing mechanism and a check-and-balance to the oversight and maintenance of the MPA. As PIPA moves forward with its management objectives, it is well positioned to be a global model for large MPA design and implementation in similar contexts. The islands and shallow reefs have already shown benefits from protection, though the pending full closure of PIPA (and assessments thereof) will be critical for determining success of the MPA as a refuge for open-ocean pelagic and deep-sea marine life. As global ocean resources are continually being extracted to support a growing global population, PIPA's closure is both timely and of global significance.

An alternative method for estimating hygroscopic growth factor of aerosol light-scattering coefficient: a case study in an urban area of Guangzhou, South China

Abstract: . A method was developed to estimate hygroscopic growth factor (f(RH)) of aerosol light-scattering coefficient (bsp), making use of the measured size- and chemically resolved aerosol samples. In this method, chemical composition of the measured aerosol samples were first reconstructed using the equilibrium model ISORROPIA II. The reconstructed chemical composition, which varies with relative humidity (RH), was then employed to calculate bsp and hygroscopic growth factor of bsp (fsp(RH)) using the Mie model. Furthermore, the calculated fsp(RH) was fitted with an empirical curve. To evaluate the applicability of fsp(RH), the curve of fsp(RH) was used to correct the long-term records of the measured bsp from the values under comparative dry conditions to the ones under ambient RH conditions. Compared with the original bsp data, the fsp(RH)-corrected bsp had a higher linear correlation with, and a smaller discrepancy from, the bsp derived directly from visibility and absorption measurements. The fsp(RH) determined here was further compared with that reported in previous studies. The method described in this manuscript provides an alternative approach to derive credible fsp(RH) with high accuracy and has many potential applications in aerosol-related research.