Mercuric chloride effects on adult rat oval cells-induced apoptosis

In the present investigation, the toxicity of mercuric chloride (HgCl₂) was evaluated in adult oval cells isolated from rat utilizing the 2-acetylaminofluorene/partial hepatectomy technique. Isolated oval cells were incubated with 5 μM of HgCl₂ for 8 hr to elucidate in vitro cytotoxic responses. Recently, autophagic cell death was found in rat hepatocytes in vitro within 30 min of incubation with 5 μM of mercury (Hg) which triggered apoptosis and necroptosis in a time-dependent manner. Nuclear degradation occurred within 30 min of incubation and progressed with time until 8 hr. Apoptosis evidenced by activation of caspase-dependent pathway between 30 min to 8 hr of incubation was mediated via interchange of death domain signaling pathways. Receptor-interacting protein played a positive role to modulate the death domain receptors in the scenario of apoptotic death of oval cells until 6 hr. Autophagic marker proteins ATG12 and LC3B exerted a significant role in triggering apoptosis in 5 μM Hg-treated oval cells. No apparent expression of apoptosis-inducing-factor (AIF) and HMGB1 indicated absence of caspase-independent apoptosis and necrosis in the rat oval cells between 30 min and 8 hr. Thus a low concentration of Hg modulates programmed cell death in adult rat oval cells by altering expression of proteins involved in the molecular mechanisms of cellular functions.     

Evaluation of Dust Generated from Basic Oxygen Furnace Steel Making

Abstract

A detailed characterization has been made of the dust generated during steel making in basic oxygen furnaces (BOF). Chemical composition and particle size distribution have been analyzed. X-ray diffraction, scanning electron microscopy, and electron probe micro-analysis techniques have been used to identify the morphology and the nature of the major iron-bearing phases as well as the gangue constituents. The dust characteristics have been found to be widely different, depending on the type of process used in BOF steel making, namely, suppressed combustion or total combustion. The type of dust abatement system (dry or wet) additionally influences the nature of the gangue constituents. The possibility of utilizing the iron-bearing major phases has been examined.     

Carbofuran induced changes in breeding of a freshwater fish,Labeo rohita (Hamilton)

The effect of carbofuran, a carbamate pesticide, on the breeding performance of the freshwater fish Labeo rohita (Hamilton) has been investigated in the present study. Breeding of L. rohita was conducted after treatment with three sublethal concentrations, i.e. 0.06, 0.15 and 0.30 mg L^?1 of carbofuran for 96 h. The present investigation showed that the number of total eggs and total amount of eggs (litre per kg body weight) decreased significantly (p < 0.01) at all concentrations of carbofuran in comparison to controls, while the reduction in fertilization percentage at all concentrations of carbofuran was not significantly different from controls. The reduction in hatching percentage, the expected number of hatchlings, and the expected number of hatched larvae were significantly (p < 0.01) different between treated and control groups at all carbofuran concentrations. No significant differences for the 96 h survivability of hatched larvae were reported at all concentrations of carbofuran.     

Effect of cypermethrin on breeding performances of a freshwater fish,Labeo rohita (Hamilton)

Abstract

Concentrations of the related elements calcium, strontium, barium, and lead were determined in soil extract, consumer stomach contents, and consumers in lead polluted and unpolluted areas. Discrimination against the nonessential metals relative to the nutritious metal calcium, as the metals were transferred through a trophic pathway was determined. Discrimination of metals varied systematically as a function of degree of nonessential element similarity to calcium. The existence of systematic trends of discrimination may facilitate the assessment of natural levels of some toxic elements (e.g. lead) in organisms.     

A study of biochemical parameters among individuals residing in a fluoride endemic area in India

Fluoride (Fl) exerts an inhibitory effect on many metabolic enzymes of various tissues. A study was carried out among individuals residing in a Fl-affected area in India. The biochemical parameters including serum enzyme activities of alkaline phosphatase (ALKP), glutamic pyruvic transaminase (SGPT), lactate dehydrogenase (LDH), and serum creatinine (CRTN) were estimated in 259 subjects compared to 233 controls. The results showed that among the Fl-exposed population, ALKP and SGPT were significantly increased compared to control. The CRTN levels were also significantly increased compared to the control subjects. LDH levels were not markedly altered. Data suggest that Fl exposure affects renal and hepatic functions in endemic areas of India.     

Municipal solid waste management in Kolkata,India – A review

Kolkata is one of four metropolitan cities in India. With an area of 187.33 sq km and a population of about 8 million, it generates around 3,000 t d^?1 of municipal solid waste (MSW) at a rate of 450–500 g per capita per day. With rapid urbanization as a result of planned and unplanned growth and industrialization, the problems associated with handling MSW have increased at an alarming rate over the past few years. No source segregation arrangement exists; there is only limited (60%) house-to-house collection; and 50–55% open vats are used in the present collection system. The operational efficiency of the Kolkata Municipal Corporation (KMC) transport system is about 50%, with a fleet composed of about 30–35% old vehicles. The majority (80%) of these, particularly the hired vehicles, are more than 20 years old. The newly added areas covered by KMC have even lower collection efficiencies, and only an informal recycling system exists. The waste collected has a low energy value (3,350–4,200 kJ kg^?1) with high moisture and inert content. A 700 t d^?1 compost plant set up in 2000 has not been functioning effectively since 2003. Open dumping (without liners and without a leachate management facility) and the threat of groundwater pollution, as well as saturation of an existing landfill site (Dhapa) are the most pressing problems for the city today. KMC spends 70–75% of its total expenditures on collection of solid waste, 25–30% on transportation, and less than 5% on final disposal arrangements. The Kolkata Environmental Improvement Project, funded by the Asian Development Bank, is seen as only a partial solution to the problem. A detailed plan should emphasize segregation at the source, investment in disposal arrangements (including the use of liners and leachate collection), and an optimized transport arrangement, among improvements.     

A study on the phytoaccumulation of waste elements in wetland plants of a Ramsar site in India

Some wetland plant species are adapted to growing in the areas of higher metal concentrations. Use of such vegetation in remediation of soil and water contaminated with heavy metals is a promising cost-effective alternative to the more established treatment methods. Throughout the year, composite industrial effluents bringing various kinds of heavy metals contaminate our study site, the East Calcutta Wetlands, a Ramsar site at the eastern fringe of Kolkata city (formerly Calcutta), India. In the present study, possible measures for remediation of contaminated soil and water (with elements namely, Ca, Cr, Cu, Pb, Zn, Mn, and Fe) of the ecosystem had been investigated. Ten common regional wetland plant species were selected to study their efficiency and diversity in metal uptake and accumulation. Results showed that Bermuda grass (Cynodon dactylon) had the highest total Cr concentration (6,601 ± 33 mg kg^???1 dw). The extent of accumulation of various elements in ten common wetland plants of the study sites was: Pb (4.4?C57 mg kg^???1 dw), Cu (6.2?C39 mg kg^???1 dw), Zn (59?C364 mg kg^???1 dw), Mn (87?C376 mg kg^???1 dw), Fe (188?C8,625 mg kg^???1 dw), Ca (969?C3,756 mg kg^???1 dw), and Cr (27?C660 mg kg^???1 dw) indicating an uptake gradient of elements by plants as Ca>Fe>Mn>Cr>Zn>Cu>Pb. The present study indicates the importance of identification and efficiency of metal uptake and accumulation capabilities by plants in relation to their applications in remediation of a contaminated East Calcutta Wetland ecosystem.     

Environmental change of coastal Sundarbans: Impact on livelihood and standard of living status of indigenous people

There is overwhelming scientific consensus that environmental change is currently having ecological and socioeconomical impacts at the micro and macrolevel. Over the coming decades, the impact of development, climate change, and urbanization on the ecosystem is likely to become even more ruthless in the Sundarbans. Like many other ecologically sensitive areas, the Sundarbans of the Indian state of West Bengal and of Bangladesh are being stressed climatically to the extreme due to their geographical location. This study explores both the ways in which residents of communities in the West Bengal and Bangladesh Sundarbans perceive changes in the environment, as well as intergenerational changes in livelihoods to be driven in a large part by environmental changes. Persons from a total of 368 households were interviewed using a structured interview tool. As an example of differences in perception between residents of the two areas, survey respondents from communities of the Sundarbans of Bangladesh were more likely to perceive that rainfall amounts are changing than did the residents interviewed from the Sundarbans of West Bengal. From the sample data, it is shown that in the Sundarbans of Bangladesh, 59% of the respondents, as compared to 63% of the respondents in West Bengal, reported that they had chosen to enter their parents’ occupations. From the multivariate logistic regression analysis, it was observed that, especially in Bangladesh when compared to West Bengal, the state of the environment plays a vital role in whether respondents adopt occupations other than those of their parents.     

Can dissimilarity lead to positive outcomes? The influence of open versus closed minds

Social identity theory and self‐categorization theory have usually been interpreted to suggest that demographic dissimilarity will negatively influence employee outcomes. However, inconsistent with this interpretation, positive and neutral relationships between demographic dissimilarity and employee outcomes have also been documented in some instances for women and minority employees. It is argued here that the influence of demographic dissimilarity on the attitudes of women and minority employees is moderated by their level of dogmatism, which influences whether they view sex‐ and race‐based status hierarchies in organizations as legitimate. Data from a survey shows that the influence of demographic dissimilarity on the organization‐based self‐esteem of employees, their level of trust in their peers and their attraction towards their peers is positive for individuals with higher level of dogmatism and negative for individuals with lower level of dogmatism. Copyright © 2003 John Wiley & Sons, Ltd.