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Ruedi M.,Natural History Museum of Geneva | Biswas J.,National Cave Research and Protection Organization | Csorba G.,Hungarian Natural History Museum
Revue Suisse de Zoologie | Year: 2012

The bat fauna of Meghalaya, north-eastern India, is very diverse but still improperly known. Recent field work revealed several previously unrecorded bats, especially in the southern and eastern hill ranges known as the Khasi and Jaintia Hills. We resolve here the systematic position of two Marina species that belong to the "swilla-group" and "cycloftis-group", respectively, using a combination of morphological and molecular characters. Both taxa proved to be morphologically and genetically distinct from any known species and are therefore described here as new species. So far, M. jaintiana sp. nov. has been found both in the Jaintia Hills of eastern Meghalaya, and in the Chin Hills of north-eastern Myanmar, while M. pluvialis sp. nov. is only known from the dense evergreen forests of the Khasi Hills, close to the Meghalaya border with Bangladesh. During the last few decades, these areas have suffered serious habitat degradation due to deforestation associated with mining activities, and both require urgent conservation measures to preserve their unique natural resources. Source


Berkelhammer M.,University of Colorado at Boulder | Berkelhammer M.,University of Illinois at Chicago | Sinha A.,California State University, Dominguez Hills | Mudelsee M.,Climate Risk Analysis | And 4 more authors.
Climate of the Past | Year: 2014

There are a number of clear examples in the instrumental period where positive El Niño-Southern Oscillation (ENSO) events were coincident with a severely weakened Indian summer monsoon (ISM). ENSO's influence on ISM precipitation has therefore remained the centerpiece of various predictive schemes of ISM rainfall for over a century. The teleconnection between ISM precipitation and ENSO has undergone a protracted weakening since the late 1980s, suggesting the strength of ENSO's influence on ISM precipitation may vary on multidecadal timescales. The recent weakening has occurred despite the fact that the ENSO system has experienced variance levels during the latter part of the 20th century that are as high as any period in the past millennium. The recent change in the ENSO-ISM coupling has prompted questions as to whether this shift represents a natural mode of climate variability or a fundamental change in ENSO and/or ISM dynamics due to anthropogenic warming or aerosol impacts on the ISM. Here we place the 20th century ENSO-ISM relationship in a millennial context by assessing the phase relationship between the two systems across the time spectrum using a a series of high-resolution reconstructions of ENSO and the ISM from tree rings, speleothems and corals. The results from all the proxies suggest that in the high-frequency domain (5-15 yr), warm (cool) sea surface temperatures in the eastern tropical Pacific lead to a weakened (strengthened) monsoon. This finding is consistent with the observed relationship between the two systems during the instrumental period. However, in the multidecadal domain (30-90 yr) the phasing between the systems is reversed such that periods of strong monsoons were, in general, coincident with periods of enhanced ENSO variability. This result is counterintuitive to the expectation that enhanced ENSO variance favors an asymmetric increase in the frequency of El Niño events and therefore a weakened monsoon system. The finding implies that the prominent multidecadal variability that characterizes the last 1000 yr of the ISM is not likely attributable to multidecadal shifts in ENSO. If there is a continued trend towards enhanced ENSO variance in the coming decades, the results presented here do not suggest this will force a reduction in ISM precipitation. © 2014 Author (s). Source


Sahu K.R.,P.A. College | Biswas J.,National Cave Research and Protection Organization | Venu Achari K.,Pandit Ravishankar Shukla University | Sinha K.M.,P.A. College
International Journal of Zoological Research | Year: 2011

Subterranean caves are always characterized by several uncommon ecological factors due to which a high degree of biological adaptation is always required to establish any population in it. In the present work, the morphology of the sound producing organ of a cave cricket Homoeogryllus indicus has been studied and the ecological importance of the same has been tried to correlate with its habitat. Fifty adult male individuals of H. indicus were collected from Kachhuwa-Pahar cave and preserved separately in plastic veil containing 4% formalin. Complete stridulatory apparatus was studied under a binocular microscope and the sketches of the tegmina and teeth were drawn by using camera lucida mounted on the microscope. The total number of teeth present in both the files were found to be comparatively less in number than the other members of the same genus which represents an example of regressed evolution. However, a comparatively regressed stridulatory system observed in this species along with other reported morphologically regressive characteristics has been discussed from the perspective of ecological fitness for cave life. © 2011 Academic Journals Inc. Source


Kulshrestha R.,MATS University | Biswas J.,National Cave Research and Protection Organization
Journal of Pure and Applied Microbiology | Year: 2013

A highly discriminatory immune system is fundamental to survival. The Immune system has a powerful collection of defense mechanisms to protect against potential invaders that would otherwise take advantage of the rich source of nutrients provided by the vertebrate host. Unlike the cells of liver, heart or lungs, the cells of the immune system are scattered throughout the body. They are present in the spleen, lymph nodes, bone marrow, and thymus & circulate through the blood and lymphatic fluid. The first line of defense is provided by the intact skin and mucous membranes of the body. There are a group of proteins (immunoglobulins) present in normal adult, they are of five types IgG, IgA, IgM, IgD, IgE. Amongst these IgG and IgA play important role in Periodontitis as IgG are the main circulating antibody in the blood and can pass from blood into tissue spaces whereas IgA protection to mucosal surfaces. Source


Sinha A.,California State University, Dominguez Hills | Berkelhammer M.,University of Colorado at Boulder | Stott L.,University of Southern California | Mudelsee M.,Climate Risk Analysis | And 4 more authors.
Geophysical Research Letters | Year: 2011

The "internally" generated intraseasonal variability of the Indian Summer Monsoon is characterized by intermittent periods of enhanced ("active") and deficient ("break") precipitation, which produce a quasi east-west precipitation dipole over the Indian subcontinent. Here we present multicentennial-length and near annually-resolved reconstructions of monsoon precipitation, inferred from absolute-dated and instrumentally calibrated speleothem oxygen isotope records from regions (central and northeast India) that have diametric responses to active-break monsoon circulation patterns. On centennial timescales (AD 1400-2008), precipitation variability from these two regions exhibit opposing behavior, oscillating between periods with a persistently "active-dominated" (AD ∼1700 to 2007) and a "break-dominated" (AD 1400 to ∼1700) regime. The switch between these regimes occurs abruptly (within decades) at a time (AD ∼ 1650-1700) when a proxy record of upwelling intensity from the Arabian Sea suggest an abrupt increase in the monsoon winds. On the basis of these observations, we hypothesize that the frequency distribution of active-break periods varies on centennial timescales, implying a leading role of internal dynamics in governing the ISM response to slowly-evolving changes in the external boundary conditions. Copyright 2011 by the American Geophysical Union. Source

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