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● B[a]P, nicotine and phenanthrene molecules altered the secondary structure of Aβ42. ● β-content of the peptide was significantly enhanced in the presence of the PAHs. ● Nicotine made stable cluster with Aβ42 peptide via hydrogen bonds. ● Phenanthrene due to its small size, interfered with the Aβ42 monomer more strongly. Recent studies have correlated the chronic impact of ambient environmental pollutants like polycyclic aromatic hydrocarbons (PAHs) with the progression of neurodegenerative disorders, either by using statistical data from various cities, or via tracking biomarkers during in-vivo experiments. Among different neurodegenerative disorders, PAHs are known to cause increased risk for Alzheimer’s disease, related to the development of amyloid beta (Aβ) peptide oligomers. However, the complex molecular interactions between peptide monomers and organic pollutants remains obscured. In this work, we performed an atomistic molecular dynamics study via GROMACS to investigate the structure of Aβ42 peptide monomer in the presence of benzo[a]pyrene, nicotine, and phenanthrene. Interestingly the results revealed strong hydrophobic, and hydrogen-bond based interactions between Aβ peptides and these environmental pollutants that resulted in the formation of stable intermolecular clusters. The strong interactions affected the secondary structure of the Aβ42 peptide in the presence of the organic pollutants, with almost 50 % decrease in the α-helix and 2 %–10 % increase in the β-sheets of the peptide. Overall, the undergoing changes in the secondary structure of the peptide monomer in the presence of the pollutants under the study indicates an enhanced formation of Aβ peptide oligomers, and consequent progression of Alzheimer’s disease.  相似文献   
2.
The Indian Himalayan Region (IHR) is suffering from environmental degradation due to population pressure and infra-structural needs. This is coupled with a natural setting, which creates problems of accelerated soil erosion and mass wasting. In view of these environmental difficulties and the growing concern for effective restoration, there has become an urgent need for multi-disciplinary coordinated improvement schemes. The mitigation of risk arising from hazardous mass wasting processes, through a careful and systematic approach, has helped in the development of the concept of Mountain Risk Engineering (MRE). The MRE practices involve an integrated approach to solving the infra-structural engineering problems of hilly and mountainous areas through environmentally conscious cost-effective and site-specific designs. However, the role of people's participation is extremely crucial for the success of such programs. This paper analyzes the perception of the local people about the approaches adopted in MRE participatory developmental programs and throws light on the intricacies of peoples' participation.  相似文献   
3.
A study was conducted in fluoride-affected Bankura and Purulia districts of West Bengal to assess the potential health risk from fluoride exposure among children, teenagers, and adults due to consumption of rice, pulses, and vegetables in addition to drinking water and incidental ingestion of soil by children. Higher mean fluoride contents (13–63 mg/kg dry weight) were observed in radish, carrot, onion bulb, brinjal, potato tuber, cauliflower, cabbage, coriander, and pigeon pea. The combined influence of rice, pulses, and vegetables to cumulative estimated daily intake (EDI) of fluoride for the studied population was found to be 9.5–16%. Results also showed that intake of ivy gourd, broad beans, rice, turnip, fenugreek leaves, mustard, spinach, and amaranth grown in the study area is safe at least for time being. The cumulative EDI values of fluoride (0.06–0.19 mg/kg-day) among different age group of people of the study area were evaluated to be ~104 times higher than those living in the control area; the values for children (0.19 and 0.52 mg/kg-day for CTE and RME scenarios, respectively) were also greater than the “Tolerable Upper Intake Level” value of fluoride. The estimated hazard index (HI) for children (3.2 and 8.7 for CTE and RME scenarios, respectively) living in the two affected districts reveals that they are at high risk of developing dental fluorosis due to the consumption of fluoride-contaminated rice, pulses, and vegetables grown in the study area in addition to the consumption of contaminated drinking water.  相似文献   
4.
The effects of varying concentrations of urea, phosphogypsum and paper mill sludge (PMS) on the morphology, histology, tissue protein content, lipid peroxidation (LPX), activities of lactate dehydrogenase (LDH), acetylcholinesterase (AChE) and catalase in earthworms Drawida willsi and Lampito mauritii have been studied over an exposure period of 24?hr. Integumentary lesions, clitellar swelling and loss of pigmentations were found to be major morpho-pathological changes in the worms. Histology indicated cuticular damage, ruptured epithelium and muscle fibres with accumulation of cellular debris. Lowest tissue protein content (57.02?±?4.02?mg/g tissue) and highest LPX (0.113?±?0.04, 0.137?±?0.08?nmol/mg protein) were noticed in D. willsi at a high concentration of PMS, whereas highest tissue protein content was observed in L. mauritii (115.32?±?7.18?mg/g tissue) with the same treatment. In both the species, LDH activity was minimum at a high concentration of urea (0.172?±?0.02; 0.247?±?0.08?U/mg protein). AChE activity was highest (0.099?±?0.002?U/mg protein) at a high concentration of PMS in D. willsi, whereas catalase activity was the maximum (0.338?±?0.02?U/mg protein) at high concentrations of PMS in L. mauritii. The study indicated that morpho-histological and enzymatic alterations in these earthworms exposed to agrochemicals could be useful biomarkers to evaluate soil toxicity.  相似文献   
5.
This study proposes a practical method to estimate elemental composition and distribution in order to attribute source and quantify impacts of aerosol particles at an urban region in Kolkata, India. Twelve-hour total particulates were collected in winter (2005–2006) and analyzed by energy-dispersive X-ray fluorescence technique to determine multi-elemental composition, especially trace metals. The aerosols consist of various elements including K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, and Pb which exhibit significant concentration at various sites (p?<?0.05). The concentration of different metallic elements were found in the order of Zn ?> ?Pb ?> ?Ni ?> ?Cu ?> ?Cr ?>? Co. Statistical multivariate analysis and correlation matrix analyses were performed for factor identification and consequent source apportionment. Contour profiles demonstrate spatial variation of elemental compositions indicating possible source contribution along with meteorological influences. Spatial differences were clearly most significant for Zn, Ni, Pb, and Cu reflecting the importance of anthropogenic inputs, primarily from automobile sources.  相似文献   
6.
The mountains hold the key to global ecological and social stability by virtue of being centres of biological and cultural diversity and the storehouse for water and other resources. However, they are becoming unable to sustain the demands of the changing life style of the growing number of inhabitants as well as the population in the plains and, therefore, the resources are depleting rapidly. Inadequacy of research and development (R&D) projects undertaken in mountain ecosystems is, perhaps, a major factor that has not enabled us to evolve and introduce suitable interventions to replenish and restore the health of the degraded mountains. In this article, taking the Indian Himalayan region as a case study, an effort has been made to understand the adequacy and appropriateness of R&D projects in mountain ecosystems by analysing the research and development projects implemented in this region from 1985–86 to1998–99. The analysis revealed inadequacy in the number and budgets of R&D projects implemented in this mountain ecosystem as a whole as well as in specific subject areas; the number of R&D projects implemented during this period was only 5.28% of the total projects, with a fund allocation of 4.45% of the total R&D budget of India, which appears to be inadequate considering the geophysical and bio-social importance of the Himalaya. The finding suggests that national funding agencies of mountain nations need to increase the number of R&D projects in mountain regions as a priority, with the intention of developing scientific packages capable of restoring the degraded ecosystem of the mountains and ensuring their sustainable development.  相似文献   
7.
Formulations of low cost bio-based oxo-biodegradable polyethylene (PE)/Lignin hybrid polymeric composites were prepared by using ethylene/vinyl acetate (EVA) copolymer as compatibilizer and a transition metal salt as oxo-biodegradation promoter. The hybrid composites and relevant Lignin-free blends were formulated by following a statistical mixture design. The effect of Lignin, pro-degradant additive, EVA copolymer and their compatibility with the PE continuous matrix, was evaluated by means of structural features by attenuated total reflectance, morphological by scanning electron microscopy, thermal by differential scanning calorimetry and thermo-gravimetric analysis and mechanical properties by an Instron Machine. The results attained in this study, regarding especially the thermal and mechanical properties, suggest that bio-based oxo-biodegradable hybrid composites offer an interesting way to produce low cost bio-based materials with fairly enhanced properties. The moderate-low cost hybrid materials appear to be attractive for their potential in the mercantile area of commodities including: packaging, personal care products, agricultural mulch films and disposable items. This will constitute a novel added-value contribution aimed at mitigating the environmental burden caused by plastic waste items improperly abandoned in the environment.  相似文献   
8.
The people inhabiting the mountains of the Central Himalayan region of India are heavily dependent on their immediate natural resources for their survival. However, this resource-poor mountain ecosystem is gradually becoming unable to provide a minimum standard of living to its continually growing population. In this ecosystem, human population is doubling every 27–30 years, against the declining resource base, particularly forests. Forest are disappearing both quantitatively and qualitatively. Against the requirement of 18 ha of forest land to maintain production in 1 ha of cultivated land, the ratio of forests to cultivated land is only 1.33: 1. The present production from grasslands supports 8 units of livestock, against the ideal 2 units, and the gap between the demand and deficit of fodder is more than 5-fold. Loss of vegetative cover is resulting in drying up of water resources, compelling the women to walk longer distances to collect water. This ecological deterioration, apart from human growth and interference, is compounded by mountain specificities such as inaccessibility, fragility, marginality, diversity, niche and adaptability. The specificities manifest in isolation, distance, poor communication, limited mobility, etc., resulting in limited external linkages and replication of external experiences, and slow pace of development. They, therefore, restrict options for economic growth, effecting poverty and affecting the quality of life of the people of the region. Poverty, in this mountain ecosystem cannot be understood and assessed independent of ecological wealth and would better be termed as ecological poverty. The development efforts to be effective in alleviating poverty here, should take into account mountain specificities and incorporate options which have larger human dimensions, such as mechanisms for population control, socio-economic and cultural conditioning, indigenous knowledge systems of the local people and simple technologies that are already in practice or have potential and are based on least external inputs.  相似文献   
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