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

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

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

New Agendas for Agricultural Research in Developing Countries: Policy Analysis and Institutional Implications

This article argues that the goals of agricultural research in poor countries have changed substantially over the last four decades. In particular they have broadened from the early (and narrow) emphasis on food production to a much wider agenda that includes poverty alleviation, environmental degradation, and social inclusion. Conversely, agricultural research systems have proved remarkably resistant to the concomitant need for changes in research focus. As a result many, at both the national and international level, are under great strain. In terms of public policy the article goes on to suggest that shortcomings of existing conceptual approaches to technology development could be supplemented by adopting analytical principles that view innovation in systemic terms. An approach where flows of knowledge between institutional nodes is a key to innovative performance (the “National Systems of Innovation” approach) is suggested as one such conceptual framework that might help supplement conventional policy analysis. An earlier version of this paper was presented at a workshop “New Policy Agendas for Agricultural Research: Implications for Institutional Arrangements” held on 28 March 2000 at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India. The workshop was supported by the UK Department of International Development (DFID) Crop Post-Harvest Programme as an output of the project “Optimising Institutional Arrangements.

Corrosion inhibition efficiency of newly synthesized quaternary ammonium salt in 1M HCl

The 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

Optimization of TiO2/MWCNT composites for efficient dye sensitized solar cells

This paper deals with the effects of introducing multiwall carbon nanotubes (MWCNTs) into photoanodes of dye sensitized solar cells (DSSCs). Mesoporous titanium dioxide (TiO2) nanoparticles were synthesized using sol–gel technique. TiO2/MWCNT composites were prepared by adding functionalized MWCNTs to TiO2 nanoparticles using two different surfactants (α-terpineol and Triton X-100). Nanoparticles and composites were characterized using Dynamic Light Scattering spectrophotometer, Raman spectrometer, X-ray diffractometer, field emission scanning electron microscope, Brunauer–Emmett–Teller surface area analyzer and UV–Vis spectrophotometer. FESEM depicted that particles were spherical in shape and their size decreased due to addition of MWCNTs. This was attributed to the decrease in the crystallite size which in turn confirmed by XRD. UV–Vis absorption spectra showed the better absorbance for the visible range of light, as the content of MWCNT is increased. From the Tauc plot optical band gap was calculated and noted that it declined gradually with the content of MWCNTs. BET surface area increased drastically which was attributed to the formation of more number of pores in the nanocomposites as visualized from FESEM. UV–Vis spectra of dye desorbed from the photoanode revealed that the dye adsorption increased as a function of MWCNT wt%. I–V studies were carried out under the illumination of 100 mW/cm2 simulated sunlight. Photoanodes prepared by both the methods showed better performance compared to pristine TiO2 photoanode, because of high conducting path and high surface area provided by MWCNTs. Photoanodes with 0.19 wt% MWCNTs in them were able to achieve maximum efficiency of 3.54 and 3.86% for method A and B respectively