Commensal in conflict: Livestock depredation patterns by free-ranging domestic dogs in the Upper Spiti Landscape,Himachal Pradesh,India

In human-populated landscapes worldwide, domestic dogs (Canis lupus familiaris) are the most abundant terrestrial carnivore. Although dogs have been used for the protection of livestock from wild carnivores, they have also been implicated as predators of livestock. We used a combination of methods (field surveys, interview surveys, and data from secondary sources) to examine the patterns and factors driving livestock depredation by free-ranging dogs, as well as economic losses to local communities in a Trans-Himalayan agro-pastoralist landscape in India. Our results show that livestock abundance was a better predictor of depredation in the villages than local dog abundance. Dogs mainly killed small-bodied livestock and sheep were the most selected prey. Dogs were responsible for the majority of livestock losses, with losses being comparable to that by snow leopards. This high level of conflict may disrupt community benefits from conservation programs and potentially undermine the conservation efforts in the region through a range of cascading effects.     

Bacterial diversity in mining and non-mining regions with emphasis on plant growth-promoting traits

A total of 20 soil samples were collected from mining and non-mining areas of coal field regions of Dhanbad, India. These samples were grown on different types of selective media and a total of 141 isolates, each having plant growth-promoting (PGP) characteristics were obtained. The isolates were further tested for PGP traits (phosphate solubilisation, production of indole acetic acid, hydrogen cyanide, ammonia and siderophores) and a biochemical analysis was done to determine the prevalent species of the region. All the strains selected showed at least two PGP characteristics, which indicated that they can be used as plant growth promoters. Bacillus and Pseudomonas species were prevalent in both mining and non-mining areas, whereas Rhizobium, Azospirillum and Azotobacter were found mostly in the non-mining area. A total of 48 Bacillus, 29 Pseudomonas, 4 Rhizobium, 11 Azospirillum and 10 Azotobacter species were obtained from the two selected regions. The soil samples from the mining region were poor in nutrient content and thus relatively lower numbers of PGP isolates were attained.     

An analytical force model for orthogonal elliptical vibration cutting technique

The elliptical vibration cutting (EVC) technique has been found to be a promising technique for ultraprecision machining of various materials. In each overlapping EVC cycle, the thickness of cut (TOC) of work material, and the tool velocity get continuously varied. These two inherent phenomena, in fact, introduce transient characteristics into its cutting mechanics, which are considered to be different from the one applied for conventional cutting technique. Recently, a few theoretical models have been developed to understand the material removal mechanism with the EVC technique; however, in those studies, the transient phenomena were not considered. In the present research, an analytical force model for the orthogonal EVC process was developed in order to fully understand the EVC mechanism, and to more accurately predict the transient cutting force values. Three important factors: (i) transient TOC, (ii) transient shear angle, and (iii) transition characteristic of friction reversal were investigated and analyzed mainly based on geometric modeling and the Lee and Shaffer's slip-line solution. Mathematical evaluation shows that they may have significant influence on EVC process, and thus on its output performance. In order to validate the proposed force model, a series of low-frequency orthogonal EVC tests were conducted. The experimental transient cutting force values were compared with the predicted values calculated using the proposed model, and they are found to be in a good agreement with each other.     

Application of sequential leaching, risk indices and multivariate statistics to evaluate heavy metal contamination of estuarine sediments: Dhamara Estuary, East Coast of India

In the present study, concentration of some selected trace metals (Fe, Mn, Ni, Co, Pb, Zn, Cu, Cr and Cd) are measured in Brahmani, Baitarani river complex along with Dhamara estuary and its near shore. Chemical partitioning has been made to establish association of metals into different geochemical phases. The exchangeable fraction is having high environmental risk among non-lithogeneous phases due to greater potential for mobility into pore water. The metals with highest bio-availability being Cd, Zn and Cr. The metals like Mn, Zn, Cd and Cu represent an appreciable portion in carbonate phase. Fe–Mn oxides act as efficient scavenger for most of the metals playing a prime role in controlling their fate and transport. Among non-lithogeneous phases apart from reducible, Cr showed a significant enrichment in organic phase. Risk assessment code values indicate that all metals except Fe fall under medium-risk zone. In estuarine zone Cd, Zn, Pb and Cr are released to 32.43, 26.10, 21.81 and 20 %, respectively, indicating their significant bio-availability pose high ecological risk. A quantitative approach has been made through the use of different risk indices like enrichment factor, geo-accumulation index and pollution load index. Factor analysis indicates that in riverine zone, Fe–Mn oxides/hydroxides seem to play an important role in scavenging metals, in estuarine zone, organic precipitation and adsorption to the fine silt and clay particles while in coastal zone, co-precipitation with Fe could be the mechanism for the same. Canonical discriminant function indicates that it is highly successful in discriminating the groups as predicted.     

Photocatalytic formation of hydrogen peroxide over highly porous illuminated ZnO and TiO2thin film

The photocatalytic formation of hydrogen peroxide over ZnO and TiO₂thin films has been investigated in aqueous phase in the presence of molecular oxygen as an electron acceptor. These films are highly porous and showed enhanced catalytic activity in the photochemical formation of hydrogen peroxide. The amount of H₂O₂formed during 2 hour light illumination is 4–6 μM and the rates of formation of hydrogen peroxide of both the films are almost comparable. The yield of hydrogen peroxide increases with the increase in irradiation time and a trend of steady state concentration of H₂O₂is observed in the case of TiO₂thin film. Photodissolution of ZnO particles is observed in some extent during the process of prolonged UV light illumination.     

Indigenous uses and structure of chir pine forest in Uttaranchal Himalaya,India

The various indigenous uses and structure of chir pine forests were studied in Uttaranchal state of the Indian Republic. A questionnaire survey was conducted in 50 villages of Uttaranchal to gather information on the indigenous uses of chir pine. For the study of community composition and structure of chir pine forest, at least 15 quadrats of 10 x 10 m were selected randomly across various localities, and the number of individuals, along with other dominant tree and shrub species, were enumerated in each quadrat. About 10 indigenous uses of chir pine were prominent in Uttaranchal. Besides resin, an important non-wood product, different parts of chir pine, such as cones, trunk, stems, wood, leaves and bark, were used by the local people. Chir pine is a subject of the folklore and mythology of indigenous cultures in Uttaranchal. Chir pine forest formed three major communities in Uttaranchal viz., sal-pine (Shorea robusta-Pinus roxburghii), pine pure stands and oak-pine (Quercus leucho-trichophora-Pinus roxburghii). These communities sustained various multiple-use trees and shrubs along with various edible mushrooms (eg. Agaricus campestris, Morchella esculenta and Sparassis crispa). The results of this study are discussed in the light of chir pine conservation and management policies.     

Changing face of polyculture in the Darma and Johaar valleys,Pithoragarh, Kumaun Himalayas

Traditional modes of living or sustenance invariably relate to immediate and surrounding resources. Traditional people use many plant resources and have developed subtle and innovative uses for them in order to obtain maximum benefit. Traditional crop varieties and races that evolved over time through trial and error, not only provide basic nutritional requirements, but also food security. While the effects of the green revolution are conspicuous in the lower Himalayas, they are less visible in the study region, the Darma and Johaar valleys in the Kumaun Himalayas. Loss of crop biodiversity has taken place over the years, principally and inadvertently related to changing lifestyle and closure of traditional trade with Tibet after the 1962 Sino-Indian war. Added to this, is a growing demand for medicinal and aromatic plants (MAPs), principally Jambu (Allium stracheyii) and caraway (Carum carvi), whose acreage has increased with the concomitant decline in area under the traditional crops. In addition, the recent discovery of Yar tsa Gumba (Cordyceps sinensis) in the alpine zones of their summer homes has reduced people's interest in sowing, rearing and caring for traditional crops, viz. beans, potatoes, amaranth, whose growing season coincides with the harvesting season of Yar tsa Gumba. The present study attempts to show the causal factors behind the loss in crop biodiversity, as well as the changing lifestyle of these traditional people, vis a vis the changes in polyculture.     

Chromium toxicity and tolerance in plants

Chromium (Cr) is the second most common metal contaminant in ground water, soil, and sediments due to its wide industrial application, hence posing a serious environmental concern. Among various valence states, Cr(III) and Cr(VI) are the most stable forms. Cr(VI) is the most persistent in the soil and is highly toxic for biota. Since Cr is a non-essential element for plants, there is no uptake mechanism; Cr is taken up along essential elements such as sulfate through sulfate transporters. Cr accumulation in plants causes high toxicity in terms of reduction in growth and biomass accumulation, and Cr induces structural alterations. Cr interferes with photosynthetic and respiration processes, and water and minerals uptake mechanism. Various enzymatic activities related to starch and nitrogen metabolism are decreased by Cr toxicity either by direct interference with the enzymes or through the production of reactive oxygen species. Cr causes oxidative damage by destruction of membrane lipids and DNA damage. Cr may even cause the death of plant species. Few plant species are able to accumulate high amount of Cr without being damaged. Such Cr-tolerant, hyperaccumulator plants are exploited for their bioremediation property. The present review discusses Cr availability in the environment, Cr transfer to biota, toxicity issues, effect on germination and plant growth, morphological and ultrastructural aberrations, biochemical and physiological alterations, effect on metabolic processes, Cr-induced alterations at the molecular level, Cr hyperaccumulation and Cr detoxification mechanism, and the role of arbuscular mycorrhizae in Cr toxicity, in plants.     

Evaluation of the possible role of five enzymes in the metabolism of IBA in mustard aphid, Lipaphis erysimi (Kalt.)

The enzymatic activity of five enzymes viz. Glutathione S-transferases, Esterases, NADH dehydrogenase, NADH oxidase and Glutathione reductase were assessed under the influence of Indole butyric acid (IBA) (400 ppm) in the nymphs (48-52h old) of mustard aphid, Lipaphis erysimi fed on radish plants treated for 13, 25 and 37h. The activity of Glutathione S-transferases, Esterases and NADH dehydrogenase increased compared to that found in the control of the same age group of nymphs and it was concluded that these enzymes might be involved in the metabolism of IBA. The other two enzymes, NADH oxidase and Glutathione reductase showed no significant increase in their activity compared to that in the control of the same age group. It was hypothesized that the latter enzymes do not play any significant role in the metabolism of IBA.