57 research outputs found
Behavioural Ecology of Sloth Bear (Melursus ursinus) In Panna National Park, Central India
Not availabl
Determinants of Entrepreneurship and Small Business Activity: A Two-Stage Regression Analysis
We developed a theoretical model of state-level entrepreneurship activity, as measured independently by firm creation, patent applications and presence of 500Inc. firms. We estimated the roles of innovations, financial capital, state resources and entrepreneurial climate. The empirical results suggest all of these factors are important in explaining some measure of entrepreneurial activity. Most importantly, we find that there is no single set of variables most important in explaining the three different measures of entrepreneurial activity used in this analysis, that is, with the exception of entrepreneurial climate. The parameter estimate for entrepreneurial climate was significantly different from zero for all the measures of entrepreneurial activity used.Financial Economics,
Spatially nested niche partitioning between syntopic grazers at foraging arena scale within overlapping home ranges.
Niche separation among species with similar resource requirements can be expressed at various spatiotemporal scales, from the resource components selected at feeding sites to habitat and home range occupation and ultimately geographic distribution ranges. African large herbivores present a challenge to niche theory because multiple species commonly overlap both spatially and in vegetation components consumed. Aided by GPS telemetry, we investigated the space use patterns of two large grazers that are frequently associated in mixed-species aggregations. Specifically, we compared a generalist grazer with hindgut fermentation (plains zebra) with a similar-sized grazing ruminant (blue wildebeest) in west-central Kruger National Park, South Africa. We found that herds of the two species overlapped substantially in the home ranges that they occupied, but exploited spatially distinct foraging arenas for periods lasting several days or weeks within these ranges. Moreover, wildebeest and zebra differed in duration of settlement, extent of areas occupied during settlement, consequent exploitation intensity per unit area, proportion of time spent within foraging arenas relative to roaming interludes, and movement rates while within these arenas. In particular, wildebeest herds concentrated within small areas for prolonged periods, while zebra herds used more foraging arenas but exploited them for briefer periods. Both species overlapped substantially in habitat use, although wildebeest more strongly favored gabbro uplands and sodic sites presenting short grass lawns while zebra made greater use of areas with a taller grass cover. Hence resource partitioning was expressed mainly through behavioral distinctions in patch exploitation at foraging arena scale rather than in home range or habitat separation. Although zebra may have been partially excluded from the grasslands kept short by wildebeest, these sites formed only a small part of the wider ranges utilized by zebra, thereby restricting the competitive consequences. Hence spatially nested resource partitioning of this form contributes to the coexistence of these two grazers, and may be a mechanism enabling niche separation among other species
Coping with spatial heterogeneity and temporal variability in resources and risks: Adaptive movement behaviour by a large grazing herbivore.
Movement is a key mean for mobile species to cope with heterogeneous environments. While in herbivorous mammals large-scale migration has been widely investigated, finescale movement responses to local variations in resources and predation risk remain much less studied, especially in savannah environments. We developed a novel approach based on complementary movement metrics (residence time, frequency of visits and regularity of visits) to relate movement patterns of a savannah grazer, the blue wildebeest Connochaetes taurinus , to fine-scale variations in food availability, predation risk and water availability in the Kruger National Park, South Africa. Wildebeests spent more time in grazing lawns where the grass is of higher quality but shorter than in seep zones, where the grass is of lower quality but more abundant. Although the daily distances moved were longer during the wet season compared to the dry season, the daily net displacement was lower, and the residence time higher, indicating a more frequent occurrence of area-concentred searching. In contrast, during the late dry season the foraging sessions were more fragmented and wildebeests moved more frequently between foraging areas. Surprisingly, predation risk appeared to be the second factor, after water availability, influencing movement during the dry season, when resources are limiting and thus expected to influence movement more. Our approach, using complementary analyses of different movement metrics, provided an integrated view of changes in individual movement with varying environmental conditions and predation risk. It makes it possible to highlight the adaptive behavioral decisions made by wildebeest to cope with unpredictable environmental variations and provides insights for population conservation
Corrosion inhibition efficiency of newly synthesized quaternary ammonium salt in 1M HCl
68-74The newly synthesized quaternary ammonium salt, 1, 4-Bis (dimethyl decyl) ethylene diammonium bromide has been
characterized by FT-IR, 1H NMR, 13C NMR. It has been examined for its corrosion efficiency by the weight loss method by
immersing in a 1M HCl solution. The surface morphology is characterized using Scanning Electron Microscopy and it
exhibited the variation between corroded surface and inhibited surface of carbon steel.Energy-Dispersive X-ray
spectroscopy also shown the differences in composition of the corroded and surface coated with inhibitor. The efficiency of
the inhibitor is investigated by varying the concentration of the inhibitor from 100 to 500 ppm and over a temperature range
from 25 to 45C. Inhibitor efficiency is maximum in the concentration range of 500 ppm and found to be 77.75% at 45C.
The plot of concentration against surface coverage revealed that, the present system follows Langmuir’s adsorption
isotherm. Compared to acidic medium, inhibitor excelled its maximum efficiency in the neutral medium
Efficiency of single and di- site phase transfer catalyzed polymerization of glycidyl methacrylate in the two-phase system: A kinetic study
In the present kinetic study, glycidyl methacrylate has been polymerized using synthesized single-site phase transfer catalyst - 2-benzoylethyldecyldimethylammonium bromide and di-site –phase transfer catalyst -1,1,4,4-tetramethyl-1,4 dioctylethylenediammonium bromide along with potassium peroxydisulfate as the initiator in inert medium and at a constant temperature of 60°C. The effect of concentrations of the monomer, initiator, catalyst, ionic strength, pH and solvent polarity on the rate of polymerization has been examined. The order with respect to the monomer, initiator, and phase transfer catalyst was found to be 1, 0.5, and 0.5, respectively. A suitable polymerization mechanism is proposed. Ionic strength and pH has no impact on the rate of polymerization. It is observed that, as the solvent's polarity increased, the rate of polymerization also increased. Di-site phase transfer catalyst results in a higher rate of polymerization compared with single-site phase transfer catalyst while polymerizing glycidyl methacrylate
Comparative study of Typhidot-M with Widal and blood culture in diagnosis of enteric fever
Objective: To evaluate the diagnostic utility of Typhidot-M and Widal test in the early diagnosis of enteric fever (EF) in terms ofsensitivity and specificity. Methods: The study included 270 children in the age group of 1-18 years admitted to the Department ofPediatrics from November 2012 to February 2014, with fever of 5 days or more and with clinical symptoms and signs suggestiveof typhoid fever. Detailed history and clinical examination findings were recorded on a standard pro forma. Complete hemogram(hemoglobin, platelet count, and total and differential leukocyte count), Typhidot-M test, Widal tube test, and blood culture weredone on day 1 of admission. For Widal test, a titer of 1 in 160 or more for “O” agglutinins and a titer of 1 in 320 or more for “H”agglutinins were considered as positive results. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value(NPV) were calculated. Results: Of 270 children included in the study, Salmonella typhi was isolated from 82 samples (30.4%)and the remaining 188 (69.6%) were blood culture negative. Widal test was positive in 107 children (39.6%) and Typhidot-M waspositive in 136 (50.4%). The sensitivity was 78%, specificity was 79.3%, PPV was 59.8%, and NPV was 91.4% for Widal test.Typhidot-M test had a sensitivity of 81.7%, specificity of 84.6%, PPV of 69.8%, and NPV of 91.4%. Conclusion: Prompt diagnosisof EF is essential for appropriate management and it is, therefore, important to have a satisfactory test to replace conventional testsused for diagnosis. The present study compares newer test (Typhidot-M) against conventional tests such as Widal test and bloodculture, and it appears to be a practical alternative to Widal test in the early detection of EF even in the resource-poor laboratoriesas it neither requires much laboratory equipment nor laboratory expertise to conduct the test. This test can be done within 7 daysof illness, but whenever feasible confirmation with blood culture is strongly recommended, especially with the well-documentedpresence of multidrug-resistant strains of salmonella typhi worldwide. However, both Widal and Typhidot-M appear to correlateless satisfactorily with blood culture, and thus, there is a need for developing a test which allows accurate and early diagnosis of EFto manage a child effectively and limit its morbidity and mortality
Efficiency of single and di- site phase transfer catalyzed polymerization of glycidyl methacrylate in the two-phase system: A kinetic study
445-452In the present kinetic study, glycidyl methacrylate has been polymerized using synthesized single-site phase transfer catalyst - 2-benzoylethyldecyldimethylammonium bromide and di-site –phase transfer catalyst -1,1,4,4-tetramethyl-1,4 dioctylethylenediammonium bromide along with potassium peroxydisulfate as the initiator in inert medium and at a constant temperature of 60°C. The effect of concentrations of the monomer, initiator, catalyst, ionic strength, pH and solvent polarity on the rate of polymerization has been examined. The order with respect to the monomer, initiator, and phase transfer catalyst was found to be 1, 0.5, and 0.5, respectively. A suitable polymerization mechanism is proposed. Ionic strength and pH has no impact on the rate of polymerization. It is observed that, as the solvent's polarity increased, the rate of polymerization also increased. Di-site phase transfer catalyst results in a higher rate of polymerization compared with single-site phase transfer catalyst while polymerizing glycidyl methacrylate
Studies on Modification of Surface Properties in Polycarbonate (PC) Film Induced by DC Glow Discharge Plasma
The polycarbonate film (PC) surface was treated using glow discharge low-pressure air plasma. The modified surface was characterized by contact angle, FTIR, XRD, AFM, and XPS analysis. The surface-modified samples were further investigated using T-peel test for technical applications. The surface energy of the sample was estimated by measuring contact angle. The results show that, after plasma treatment, the root mean square (RMS) roughness of PC film was gradually increased with exposure time. Plasma treatment modified the chemical composition of the polymer surface and it made the surface to be highly hydrophilic. It was found that the air plasma treatment increases the polar component of PC film
CNX-013-B2, a unique pan tissue acting rexinoid, modulates several nuclear receptors and controls multiple risk factors of the metabolic syndrome without risk of hypertriglyceridemia, hepatomegaly and body weight gain in animal models
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