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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.


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).


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.


Sinha A.,California State University, Dominguez Hills | Kathayat G.,Xi'an Jiaotong University | Cheng H.,Xi'an Jiaotong University | Cheng H.,University of Minnesota | And 6 more authors.
Nature Communications | Year: 2015

Observations show that summer rainfall over large parts of South Asia has declined over the past five to six decades. It remains unclear, however, whether this trend is due to natural variability or increased anthropogenic aerosol loading over South Asia. Here we use stable oxygen isotopes in speleothems from northern India to reconstruct variations in Indian monsoon rainfall over the last two millennia. We find that within the long-term context of our record, the current drying trend is not outside the envelope of monsoon' s oscillatory variability, albeit at the lower edge of this variance. Furthermore, the magnitude of multi-decadal oscillatory variability in monsoon rainfall inferred from our proxy record is comparable to model estimates of anthropogenic-forced trends of mean monsoon rainfall in the 21st century under various emission scenarios. Our results suggest that anthropogenic-forced changes in monsoon rainfall will remain difficult to detect against a backdrop of large natural variability. © 2015 Macmillan Publishers Limited. All rights reserved.


PubMed | University of Minnesota, Ruhr University Bochum, Xi'an Jiaotong University, Alfred Wegener Institute for Polar and Marine Research and 3 more.
Type: | Journal: Nature communications | Year: 2015

Observations show that summer rainfall over large parts of South Asia has declined over the past five to six decades. It remains unclear, however, whether this trend is due to natural variability or increased anthropogenic aerosol loading over South Asia. Here we use stable oxygen isotopes in speleothems from northern India to reconstruct variations in Indian monsoon rainfall over the last two millennia. We find that within the long-term context of our record, the current drying trend is not outside the envelope of monsoons oscillatory variability, albeit at the lower edge of this variance. Furthermore, the magnitude of multi-decadal oscillatory variability in monsoon rainfall inferred from our proxy record is comparable to model estimates of anthropogenic-forced trends of mean monsoon rainfall in the 21st century under various emission scenarios. Our results suggest that anthropogenic-forced changes in monsoon rainfall will remain difficult to detect against a backdrop of large natural variability.


Biswas J.,National Cave Research and Protection Organization | Sharma K.,National Cave Research and Protection Organization | Sharma K.,Arts and Commerce Girls college | Harris K.K.,National Cave Research and Protection Organization | And 2 more authors.
Iranian Journal of Microbiology | Year: 2013

Background and Objectives: In the last few decades, losses of our cultural heritage due to biodeteriorationare beinghighly recognized. From museum objects to rock monuments, the microbial biodeterioration agents are found to be the most destructive. Possibilities for proper preservative measure(s) are always more when it is only a monument, statue, museum article, or pre-historic art in any small subterranean cave. Nevertheless, preservation/protection of the footprints occupying a big area, lying scattered in a very negligible manner requires safeguard against several deterioration factors; right from various physical, chemical and biological agents which are indeed interrelated to each other. Materials and Methods: In the present study, some microbial communities possibly responsible for deteriorating the rocks of Kabra-pahad, where the most famous pre-historic rock paints of India prevail have been identified. The diversity of fungi and bacteria present in the stone crust of the infected areas has been studied by employing standard laboratory methods. Results:The cultivated cultures confirmed total fifteen fungal species, among which Aspergillus group were the most dominant. Among bacteria, total 80 numbers of colonies were observed that dominated by two major groups; Micrococcus. spp and Staphylococcus spp. Conclusion: The pre-historic footprint in the form of rock paints in Kabra-pahad of district Raigarh, Chhattisgarh, India is lying in a very deteriorated manner. In the present study, we have tried to identify few major deteriorating factors that are responsible for such degradation of our existing pre-historic footprints.


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.


Rajput Y.,National Cave Research and Protection Organization | Rai V.,Pandit Ravishankar Shukla University | Biswas J.,National Cave Research and Protection Organization
Research Journal of Environmental Toxicology | Year: 2012

Bacterial communities are often found to play a major role in building the foundation of food chain in the food starved cave ecosystem. Earlier it was assumed that due to lack of direct external environmental impact the caves were an almost sterile ecosystem. But today, the ever increasing human activities inside it, in the form of ecotourism exert a major impact on its native microbes, often stopping its growth and polluting the whole ecosystem. The situation is often found to be responsible for producing some human pathogenic bacteria inside it, which might pose a threat of infection to the other tourists. Kotumsar cave is a well known tourist pulling limestone cave from central part of India which is also a harbour of various native cavernicoles. In the present study, the bacterial communities existing in different sediments of this cave were screened and identified. The growth rates of each isolate were also verified against various temperature ranges and the maximum growth was found to coincide with the annual mean temperature of the cave. Further, the impact of the same has been correlated with the existing biodiversity, geophysical factors and the human activities inside the cave. Finally, the probabilities of pathogenic threats to human beings due to the respective bacterial communities have also been discussed. © 2012 Academic Journals Inc.


Rajput Y.,National Cave Research and Protection Organization | Rajput Y.,Pandit Ravishankar Shukla University | Biswas J.,National Cave Research and Protection Organization | Rai V.,Pandit Ravishankar Shukla University
International Journal of Biological Chemistry | Year: 2012

The almost high and stable environmental factors always represent a subterranean cave as one of the most vulnerable environments on Earth. In such conditions, the microbial communities that survive definitely reveal strong antimicrobial and other relevant biological activities. In the present study, the antimicrobial activity and the antibiotic sensitivity of seven Streptomyces strains isolated from various depth dependent microhabitats of a subterranean cave has been tested. Antimicrobial activity was found maximum against E. coli than Staphylococcus aureus and Pseudomonas aeruginosa. Further, the strains isolated from the deeper habitats of the cave have revealed much antagonistic activities as compared to the strains of anterior habitats. Some interesting results have also been revealed from antibiotic sensitivity tests which altogether indicate the possibilities for occurrence of high potential Streptomyces strains from this particular cave, useful for biotechnological tools. © 2012 Academic Journals Inc.


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.

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