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Tamilnadu, India

Baskaran N.,Indian Institute of Science | Baskaran N.,AVC College Autonomous | Kannan G.,Indian Institute of Science | Anbarasan U.,Indian Institute of Science | And 2 more authors.
Mammalian Biology | Year: 2013

Spatial information at the landscape scale is extremely important for conservation planning, especially in the case of long-ranging vertebrates. The biodiversity-rich Anamalai hill ranges in the Western Ghats of southern India hold a viable population for the long-term conservation of the Asian elephant. Through rapid but extensive field surveys we mapped elephant habitat, corridors, vegetation and land-use patterns, estimated the elephant population density and structure, and assessed elephant-human conflict across this landscape. GIS and remote sensing analyses indicate that elephants are distributed among three blocks over a total area of about 4600km2. Approximately 92% remains contiguous because of four corridors; however, under 4000km2 of this area may be effectively used by elephants. Nine landscape elements were identified, including five natural vegetation types, of which tropical moist deciduous forest is dominant. Population density assessed through the dung count method using line transects covering 275km of walk across the effective elephant habitat of the landscape yielded a mean density of 1.1 (95% CI=0.99-1.2)elephant/km2. Population structure from direct sighting of elephants showed that adult male elephants constitute just 2.9% and adult females 42.3% of the population with the rest being sub-adults (27.4%), juveniles (16%) and calves (11.4%). Sex ratios show an increasing skew toward females from juvenile (1:1.8) to sub-adult (1:2.4) and adult (1:14.7) indicating higher mortality of sub-adult and adult males that is most likely due to historical poaching for ivory. A rapid questionnaire survey and secondary data on elephant-human conflict from forest department records reveals that villages in and around the forest divisions on the eastern side of landscape experience higher levels of elephant-human conflict than those on the western side; this seems to relate to a greater degree of habitat fragmentation and percentage farmers cultivating annual crops in the east. We provide several recommendations that could help maintain population viability and reduce elephant-human conflict of the Anamalai elephant landscape. © 2013 Deutsche Gesellschaft für Säugetierkunde.

Prabakaran K.,Bharathiar University | Sekar S.,AVC College Autonomous
Communications in Computer and Information Science | Year: 2011

In this paper, a new method known as Single Term Haar Wavelet Series (STHWS) has been presented to obtain the solution for linear and non-linear singular systems. This new approach provides a better effectiveness to find discrete solutions of linear and non-linear singular systems for any length of time t. This is a direct method and can be easily implemented in a digital computer. © 2011 Springer-Verlag Berlin Heidelberg.

Le Rossignol A.P.,University of Exeter | Buckingham S.G.,University of Exeter | Lea S.E.G.,University of Exeter | Nagarajan R.,University of Exeter | Nagarajan R.,AVC College Autonomous
Journal of Experimental Marine Biology and Ecology | Year: 2011

Predators are able to identify fine characteristic features of prey and use them to maximise the profitability of foraging. Oystercatchers Haematopus ostralegus select thin-shelled mussels Mytilus edulis to hammer through because they are easier to crack than thick-shelled mussels. But mussel shells are composite structures, so we need to ask what it is about these thin-shelled mussels that make them vulnerable. Here we show that the mussels damaged by Oystercatchers were mainly distinguished by having a significantly thinner prismatic layer than undamaged mussels. Regression analysis indicated that the Oystercatchers' shell selection was independently influenced by the thickness of the prismatic and nacreous layers, but the coefficient for the thickness of the prismatic layer was almost one and a half times that for the nacreous layer. Thus the thickness of the prismatic layer largely determines the vulnerability of the mussel shells. Oystercatchers were more likely to attack mussels by the right valve than the left, and this tendency was accentuated in larger mussels and those with a thicker nacreous layer. © 2011 Elsevier B.V.

Ramalingam S.,AVC College Autonomous | Periandy S.,Tagore Arts College | Narayanan B.,Tagore Arts College | Mohan S.,University
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2010

The FTIR and FTRaman spectra of 2-bromo-4-methyl aniline (2-B-4-MA) molecule have been recorded using Brucker IFS 66 V spectrometer in the range of 4000-100 cm-1. The molecular geometry and vibrational frequencies in the ground state are calculated using the Hartree-Fock (HF) and B3LYP with 6-31+G*(d, p), 6-311+G*(d, p) and 6-311++G* (d, p) basis sets. The computed values of frequencies are scaled using a suitable scale factor to yield good coherence with the observed values. The isotropic HF and DFT analysis showed good agreement with experimental observations. Comparison of the fundamental vibrational frequencies with calculated results by HF and B3LYP methods indicates that B3LYP/6-311++G* (d, p) is superior to HF/6-31+G* for molecular vibrational problems. The complete data of this title compound provide the information for future development of substituted aniline. The influences of bromine atom, methyl group and amine group on the geometry of benzene and its normal modes of vibrations have also been discussed. Crown Copyright © 2010.

Ramalingam S.,AVC College Autonomous | Periandy S.,Thagore Arts College | Govindarajan M.,Avvaiyar Government College for Women | Mohan S.,University
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2010

In this work, the experimental and theoretical study on molecular structure and vibrational spectra of 4-nitrotoluene are studied. The FTIR and FTRaman experimental spectra of the molecule have been recorded in the range of 4000-100 cm-1. Making use of the recorded data, the complete vibrational assignments are made and analysis of the observed fundamental bands of molecule is carried out. The experimental determinations of vibrational frequencies are compared with those obtained theoretically from ab initio HF and DFT quantum mechanical calculations using HF/6-31G (d, p), B3LYP/6-31++G* (d, p) and B3LYP/6-311++G* (d, p) methods. The differences between the observed and scaled wave number values of most of the fundamentals are very small in B3LYP than HF. The geometries and normal modes of vibrations obtained from ab initio HF and B3LYP calculations are in good agreement with the experimentally observed data. Comparison of the simulated spectra provides important information about the ability of the computational method (B3LYP) to describe the vibrational modes. The vibrations of NO2 and CH3 groups coupled with skeletal vibrations are also investigated. © 2010 Elsevier B.V. All rights reserved.

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