匹配条件: “Nilantha Vishvanath” ,找到相关结果约17条。
Re-discovery of Pouch bearing sheath tailed bat Saccolaimus saccolaimus Temminck (Chiroptera: Emballonuridae) from Sri Lanka after 75 years
Ranil P. Nanayakkara,Nilantha Vishvanath,T. G. Tharaka Kusuminda
Asian Journal of Conservation Biology , 2012,
Abstract: Saccolaimus saccolaimus Temminck, 1838, was first collected by the Museum of Natural History of Sri Lanka in the year 1919 and the first published record of this bat was in 1935 by W.W.A. Philips, though specimens were collected at various times for the collection of the Natural History Museum of Sri Lanka. However, after 1936 there were no records of the species, though, several surveys were conducted on the bat fauna of the island. The species had not been reported since, and was considered as Data Deficient according to latest literature. Here we report on its re-discovery.
The Range Extension of the Critically Endangered, Poecilotheria smithi in Sri Lanka, with Notes on its Sociality
Ranil P. Nanayakkara,Nilantha Vishvanath,T. G. Tharaka Kusuminda,G.A.S.M. Ganehiarachchi
Asian Journal of Conservation Biology , 2013,
Abstract: Poecilotheria smithi is a Critically Endangered Theraposid known only from the type locality Haragama in the Kandy District, Sri Lanka. It was thought to be distribution specific to Haragama. During a survey on the genus Poecilotheria, which was initiated in 2011 by the authors, P. smithi was recorded, the first confirmed observation of P. smithi outside of its type locality from the Matale district about 31.42 Km in aerial distance northwest of the type locality. Distribution of this species extended in Sri Lanka by this novel record. P. smithi displays the social behaviour of sharing same microhabitat with few individuals. As demonstrated for P. smithi, we suggest the large group size and social behaviour observed was in response to unavailability of suitable micro habitat for the mature individuals.
Investigation of Surface Tryptophan of Protein by Selective Excitation at 305 nm  [PDF]
Vishvanath Tiwari, Monalisa Tiwari
Journal of Biophysical Chemistry (JBPC) , 2015, DOI: 10.4236/jbpc.2015.63009
Abstract: Intrinsic fluorescence of tryptophan is a powerful tool that is used to investigate structure, dynamics, and folding-unfolding of proteins. Here, we have signified the importance of selective monitoring of “surface” tryptophans from the “buried” tryptophans in a protein via selective excitation of surface tryptophan using light of 305 nm wavelength. We have also enlightened the effect of pH and temperature on the conformation of protein by selective excitation of surface tryptophan of protein using 305 nm light. The result concludes that this novel approach could be used to investigate surface tryptophan of protein selectively at diverse conditions.
Developments in Fractionation and Measurement of Soil Organic Carbon: A Review  [PDF]
Yadunath Bajgai, Nilantha Hulugalle, Paul Kristiansen, Melinda McHenry
Open Journal of Soil Science (OJSS) , 2013, DOI: 10.4236/ojss.2013.38041

Soil organic carbon (SOC) is the percentage measure of carbon (C) derived from living organisms in soil. Stability of soil organic matter (SOM) can be defined in terms of how easily C and nitrogen in the SOM can be decomposed. Due to the implications in the permanence of SOC during sequestration there is scientific interest in fractionation of SOM into different fractions. A large number of SOM fractionation procedures have been developed to distinguish between SOM to study whether it is liable or recalcitrant to activities of soil microbes. There are physical and chemical fractionation techniques. The former is based on particle size and density of soil samples or combination of the two, and the latter on the reaction of chemical on SOM for the separation of stable SOC. Each fraction of SOC in the laboratory can be commonly determined using wet oxidation by Walkley-Black method and dry combustion by LECO CN Analyzer. With the advancement in chemometric statistical techniques; faster, robust, cheaper and non-destructive methods are emerging. The chemometric statistical techniques do not require any reagents for analysis compared with the wet oxidation or dry combustion methods. Thus, these emerging techniques are highly attractive for studies where a large number of analyses are required. For in situ measurement of SOC, spectral reflectance technology is developed to facilitate instant measurement in the field using the sensors or by remote sensing.

New evolutionary frontiers from unusual virus genomes
Christopher Desjardins, Jonathan A Eisen, Vishvanath Nene
Genome Biology , 2005, DOI: 10.1186/gb-2005-6-3-212
Abstract: If an alien landed on Earth and studied the biology here, it might justifiably conclude that viruses run the planet. They are numerically the most abundant biological entities [1], and they are profoundly important in shaping the ecology and evolution of just about every species on Earth [2]. Yet viruses are not considered to be alive by most biologists, and they have arguably fallen by the wayside in the genomics revolution [3]. The recent publication of the genome sequences of two unusual viruses, however, highlights the wealth of information that remains to be discovered through viral genomics. Here, we discuss Mimivirus [4] and Cotesia congregata Bracovirus [5] (CcBV) and the interesting questions they raise concerning the biology and evolution of viruses.Both Mimivirus and CcBV are classified as double-stranded DNA (dsDNA) viruses, and some of their features are summarized in Table 1. Mimivirus was discovered in amoebae [6], and it has a cycle of viral transmission and replication that is typical of many dsDNA viruses (Figure 1a). Its name is derived from 'mimicking microbe,' in reference to the bacterium-like appearance of its large particle (400 nm in diameter) and its Gram-positive staining. Mimivirus has the largest known viral genome (1.18 megabase-pairs) and encodes an unprecedented number of components of the transcriptional, translational and replication machinery, many of which have not previously been identified in viruses [4]. In addition, the genome encodes a large number of genes associated with metabolic pathways. Although the size and content of the Mimivirus genome might rival those of some obligate intracellular prokaryotes, it still appears to be absolutely dependent on its host cell for synthesis of proteins.CcBV differs from Mimivirus and other viruses in many fundamental aspects. As a member of the Polydnaviridae, the transmission and replication cycle of this Bracovirus is unconventional [7]. The Polydnaviridae - pronounced polyd-na-virida
Comparative Proteomics of Inner Membrane Fraction from Carbapenem-Resistant Acinetobacter baumannii with a Reference Strain
Vishvanath Tiwari, Jitendraa Vashistt, Arti Kapil, Rajeswari R. Moganty
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0039451
Abstract: Acinetobacter baumannii has been identified by the Infectious Diseases Society of America as one of the six pathogens that cause majority of hospital infections. Increased resistance of A. baumannii even to the latest generation of β-lactams like carbapenem is an immediate threat to mankind. As inner-membrane fraction plays a significant role in survival of A. baumannii, we investigated the inner-membrane fraction proteome of carbapenem-resistant strain of A. baumannii using Differential In-Gel Electrophoresis (DIGE) followed by DeCyder, Progenesis and LC-MS/MS analysis. We identified 19 over-expressed and 4 down-regulated proteins (fold change>2, p<0.05) in resistant strain as compared to reference strain. Some of the upregulated proteins in resistant strain and their association with carbapenem resistance in A. baumannii are: i) β-lactamases, AmpC and OXA-51: cleave and inactivate carbapenem ii) metabolic enzymes, ATP synthase, malate dehydrogenase and 2-oxoglutarate dehydrogenase: help in increased energy production for the survival and iii) elongation factor Tu and ribosomal proteins: help in the overall protein production. Further, entry of carbapenem perhaps is limited by controlled production of OmpW and low levels of surface antigen help to evade host defence mechanism in developing resistance in A. baumannii. Present results support a model for the importance of proteins of inner-membrane fraction and their synergistic effect in the mediation of resistance of A. baumannii to carbapenem.
Global comparative analysis of ESTs from the southern cattle tick, Rhipicephalus (Boophilus) microplus
Minghua Wang, Felix D Guerrero, Geo Pertea, Vishvanath M Nene
BMC Genomics , 2007, DOI: 10.1186/1471-2164-8-368
Abstract: We present a global comparative genomic analysis of a gene index of R. microplus comprised of 13,643 unique transcripts assembled from 42,512 expressed sequence tags (ESTs), a significant fraction of the complement of R. microplus genes. The source material for these ESTs consisted of polyA RNA from various tissues, lifestages, and strains of R. microplus, including larvae exposed to heat, cold, host odor, and acaricide. Functional annotation using RPS-Blast analysis identified conserved protein domains in the conceptually translated gene index and assigned GO terms to those database transcripts which had informative BlastX hits. Blast Score Ratio and SimiTri analysis compared the conceptual transcriptome of the R. microplus database to other eukaryotic proteomes and EST databases, including those from 3 ticks. The most abundant protein domains in BmiGI were also analyzed by SimiTri methodology.These results indicate that a large fraction of BmiGI entries have no homologs in other sequenced genomes. Analysis with the PartiGene annotation pipeline showed 64% of the members of BmiGI could not be assigned GO annotation, thus minimal information is available about a significant fraction of the tick genome. This highlights the important insights in tick biology which are likely to result from a tick genome sequencing project. Global comparative analysis identified some tick genes with unexpected phylogenetic relationships which detailed analysis attributed to gene losses in some members of the animal kingdom. Some tick genes were identified which had close orthologues to mammalian genes. Members of this group would likely be poor choices as targets for development of novel tick control technology.Rhipicephalus (Boophilus) microplus, the tropical or southern cattle tick, is one of the most economically important tick vectors of pathogens that affect the global cattle population [1]. The tick transmits protozoan (Babesia bovis and Babesia bigemina) and prokaryotic (Anaplas
Plasmodium vivax: paroxysm-associated lipids mediate leukocyte aggregation
Nadira Karunaweera, Deepani Wanasekara, Vishvanath Chandrasekharan, Kamini Mendis, Richard Carter
Malaria Journal , 2007, DOI: 10.1186/1475-2875-6-62
Abstract: Whole blood cells from uninfected malaria-na?ve donors were incubated with plasma taken during a paroxysm or normal human plasma as a control and cell smears were observed under the microscope for the presence of leukocyte aggregates. Plasma factors involved in mediating the leukocyte aggregation were identified using immune depletion and reconstitution experiments. Furthermore, biochemical characterization was carried out to determine the chemical nature of the active moieties in plasma present during paroxysms.Leukocyte aggregates were seen exclusively when cells were incubated in plasma collected during a paroxysm. Immune depletion and reconstitution experiments revealed that the host cytokines TNF-alpha, GM-CSF, IL-6 and IL-10 and two lipid fractions of paroxysm plasma comprise the necessary and sufficient mediators of this phenomenon. The two lipid components of the paroxysm plasmas speculated to be of putative parasite origin, were a phospholipid-containing fraction and another containing cholesterol and triglycerides. The phospholipid fraction was dependent upon the presence of cytokines for its activity unlike the cholesterol/triglyceride-containing fraction which in the absence of added cytokines was much more active than the phospholipids fraction. The biological activity of the paroxysm plasmas from non-immune patients who presented with acute P. vivax infections was neutralized by immune sera raised against schizont extracts of either P. vivax or Plasmodium falciparum. However, immune sera against P. vivax were more effective than that against P. falciparum indicating that the parasite activity involved may be antigenically at least partially parasite species-specific.Leukocyte aggregation was identified as associated with paroxysms in P. vivax infections. This phenomenon is mediated by plasma factors including host-derived cytokines and lipids of putative parasite origin. The characteristics of the phospholipid fraction in paroxysm plasma are congruent
Jain Hardik,Arora Vimal,Sharma Vishvanath,Jaithlia Rajiv
International Research Journal of Pharmacy , 2011,
Abstract: The aim of the present study was to prepare mouth dissolving tablets of Bambuterol hydrochloride by using pertinent disintegrants. The tablets were prepared using mannitol and lactose along with two levels of disintegrant by direct compression method. The superdisintegrants used in this study were croscamellose sodium (CCS) and sodium starch glycolate (SSG). The tablets were evaluated for uniformity of weight, thickness, hardness, friability, wetting time, water absorption ratio, disintegration time and dissolution study. Using the same excipients, the tablets were prepared, without disintegrants and were evaluated in the similar way. Fromm the result obtained, it can be concluded that the tablet formulation (batch B4) showed disintegration time of 25±2.0 seconds in vitro. The hardness, friability and dissolution rate of prepared tablet (batch B4) were found to be acceptable according to standard limits.
The Importance of Poisoning vs. Road Traffic Injuries as a Cause of Death in Rural Sri Lanka
Michael Eddleston, Nilantha Udayakumara, Sriyantha Adhikari, Dhamika de Silva, M. H. Rezvi Sheriff, Dhananjaya L. Waidyaratne
PLOS ONE , 2007, DOI: 10.1371/journal.pone.0000599
Abstract: Background Road traffic crashes are considered by the WHO to be the most important global cause of death from injury. However, this may not be true for large areas of rural Asia where road vehicles are uncommon. The issue is important, since emphasising the importance of road traffic crashes risks switching resources to urban areas, away from already underfunded rural regions. In this study, we compared the importance of road traffic crashes with other forms of injury in a poor rural region of South Asia. Methodology/Principal Findings We collected data on all deaths from injury in the North Central Province of Sri Lanka (NCP; population 1,105,198 at 2001 census) over 18 months using coronial, hospital, and police data. We calculated the incidence of death from all forms of intentional and unintentional injury in the province. The annual incidence of death from injury in the province was high: 84.2 per 100,000 population. Half of the deaths were from self-harm (41.3/100,000). Poisoning (35.7/100,000)—in particular, pesticide self-poisoning (23.7/100,000)—was the most common cause of death, being 3.9-fold more common than road traffic crashes (9.1/100,000). Conclusions/Significance In poor rural regions of South Asia, fatal self-harm and pesticide self-poisoning in particular are significantly more important than road traffic injuries as a cause of death. It is possible that the data used by the WHO to calculate global injury estimates are biased towards urban areas with better data collection but little pesticide poisoning. More studies are required to inform a debate about the importance of different forms of injury and how avoidable deaths from any cause can be prevented. In the meantime, marked improvements in the effectiveness of therapy for pesticide poisoning, safer storage, reduced pesticide use, or reductions in pesticide toxicity are required urgently to reduce the number of deaths from self-poisoning in rural Asia.

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