462 research outputs found

    Tetraphyllin B and epi-tetraphyllin B from Adenia glauca Schinz

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    Tetraphyllin B and epi-tetraphyllin B have been isolated from the South African plant Adenia glauca Schinz in an approximate ratio of 5 : 1. The structures were established by ÂčH-NMR.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Biomedical Research, University of Illinois. NSF Grant NSF DEB 79-08525. Graduate Research Board, University of Illinois. University of Illinois NSF Regional Instrumentation Facility, Grant Number NSF CHE 79-16100

    The Practice of Dentistry by Australian- and Overseas- Trained Dentists in Australia: Discriminant Analysis of key Predictors

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    Available online 18 February 2021INTRODUCTION: Overseas-trained dentists comprise at least one-fourth of the overall Australian dental workforce. This study examined characteristics and practice differences between Australian- and overseas-trained dentists to identify key predictors that best differentiate their dentistry practices. METHODS: Data for the study were from the Longitudinal Study of Dentist Practice Activity (LSDPA), a survey of a nationally representative random sample of dentists in Australia commencing in 1983-1984 and repeated every 5 years. Dentists were surveyed on a wide range of items including participant characteristics, practice patterns, practice inputs, direct demand, and productivity measures. Data were weighted to provide national estimates by age, sex, and practice type. Discriminant function analysis was used to examine the predictor variables that best distinguished between the two groups. Analysis was limited to the most recent wave of the study. RESULTS: A total of 1148 dentists (response rate = 67%) responded to the survey in 2009-2010; 648 cases were available for the discriminant analysis. The discriminant functions for the full sample and each of the 3 age groups (<35 years; 35-50 years; and 50+ years) were found effective to separate dentists into 2 groups (Australian and overseas), with the proportion of cases correctly classified being highest for the oldest age group (89.7% for 50+ years). Female gender, type of practice (working in public sector), and working in disadvantaged areas were significant predictors, with more prominence in the 35- to 50-year age group. Practice inputs, demand, and productivity measures offered less discriminative capacity between the dentists. CONCLUSION: Overseas-trained dentists contribute towards providing dental care to underserved populations, the public sector, and in rural and remote locations. This study provided basis to argue that policies to encourage overseas-trained dentists to contribute towards areas of need locations have been successful, and key productivity measures were also similar to Australian-trained dentists.Madhan Balasubramanian, A. John Spencer, Woosung Sohn, David S. Brenna

    Cost implications of African swine fever in smallholder farrow-to-finish units : economic benefits of disease prevention through biosecurity

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    African swine fever remains the greatest limitation to the development of the pig industry in Africa, and parts of Asia and Europe. It is especially important in West and Central African countries where the disease has become endemic. Biosecurity is the implementation of a set of measures that reduce the risk of infection through segregation, cleaning and disinfection. Using a 122-sow piggery unit, a financial model and costing were used to estimate the economic benefits of effective biosecurity against African swine fever. The outcomes suggest that pig production is a profitable venture that can generate a profit of approximately US109637.40perannumandthatanoutbreakofAfricanswinefever(ASF)hasthepotentialtocauselossesofuptoUS109 637.40 per annum and that an outbreak of African swine fever (ASF) has the potential to cause losses of up to US910 836.70 in a single year. The implementation of biosecurity and its effective monitoring can prevent losses owing to ASF and is calculated to give a benefit-cost ratio of 29. A full implementation of biosecurity will result in a 9.70% reduction in total annual profit, but is justified in view of the substantial costs incurred in the event of an ASF outbreak. Biosecurity implementation is robust and capable of withstanding changes in input costs including moderate feed price increases, higher management costs and marginal reductions in total outputs. It is concluded that biosecurity is a key to successful pig production in an endemic situation.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1865-1682ab201

    Peasant farmer behavior and cereal technologies: stochastic programming analysis in Niger

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    Peasant farmers in Sahelian West Africa adjust to rainfall uncertainties in the agricultural season by making decisions sequentially as a function of the evolving rainfall patterns. Understanding such flexibilities in farmer decision-making is central to technology introduction. This paper determines how sequential decision making under weather uncertainty affects the adoption and farm-level effects of cereal technologies in Niger. The study also draws policy implications for a price floor to arrest the substantial fall in cereal prices in good rainfall years when farmers have more grains to sell. The methodology used is discrete stochastic programming. The paper shows that the ability of peasant farmers to adapt cropping and resource management strategies to the rainfall patterns is the basis for their survival in this high-risk environment. Model results show that by (a) carrying a portfolio mix of varieties of varying maturities, and (b) making sequential decisions based upon rainfall expectations, farmers can adapt to the production uncertainties. Breeding programmes should therefore be diversified to develop not only early-maturing cultivars, but also improved intermediate and long-season varietie

    Dynamic Ordering and Transverse Depinning of a Driven Elastic String in a Disordered Media

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    We examine the dynamics of an elastic string interacting with quenched disorder driven perpendicular and parallel to the string. We show that the string is the most disordered at the depinning transition but with increasing drive partial ordering is regained. For low drives the noise power is high and we observe a 1/f^2 noise signature crossing over to a white noise character with low power at higher drives. For the parallel driven moving string there is a finite transverse critical depinning force with the depinning transition occuring by the formation of running kinks.Comment: 4 pages, 4 postscript figure

    Study of the B^0 Semileptonic Decay Spectrum at the Upsilon(4S) Resonance

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    We have made a first measurement of the lepton momentum spectrum in a sample of events enriched in neutral B's through a partial reconstruction of B0 --> D*- l+ nu. This spectrum, measured with 2.38 fb**-1 of data collected at the Upsilon(4S) resonance by the CLEO II detector, is compared directly to the inclusive lepton spectrum from all Upsilon(4S) events in the same data set. These two spectra are consistent with having the same shape above 1.5 GeV/c. From the two spectra and two other CLEO measurements, we obtain the B0 and B+ semileptonic branching fractions, b0 and b+, their ratio, and the production ratio f+-/f00 of B+ and B0 pairs at the Upsilon(4S). We report b+/b0=0.950 (+0.117-0.080) +- 0.091, b0 = (10.78 +- 0.60 +- 0.69)%, and b+ = (10.25 +- 0.57 +- 0.65)%. b+/b0 is equivalent to the ratio of charged to neutral B lifetimes, tau+/tau0.Comment: 14 page, postscript file also available at http://w4.lns.cornell.edu/public/CLN

    Measurement of the Mass Splittings between the bbˉχb,J(1P)b\bar{b}\chi_{b,J}(1P) States

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    We present new measurements of photon energies and branching fractions for the radiative transitions: Upsilon(2S)->gamma+chi_b(J=0,1,2). The masses of the chi_b states are determined from the measured radiative photon energies. The ratio of mass splittings between the chi_b substates, r==(M[J=2]-M[J=1])/(M[J=1]-M[J=0]) with M the chi_b mass, provides information on the nature of the bbbar confining potential. We find r(1P)=0.54+/-0.02+/-0.02. This value is in conflict with the previous world average, but more consistent with the theoretical expectation that r(1P)<r(2P); i.e., that this mass splittings ratio is smaller for the chi_b(1P) triplet than for the chi_b(2P) triplet.Comment: 11 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Radiative Decay Modes of the D0D^{0} Meson

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    Using data recorded by the CLEO-II detector at CESR we have searched for four radiative decay modes of the D0D^0 meson: D0â†’Ï•ÎłD^0\to\phi\gamma, D0â†’Ï‰ÎłD^0\to\omega\gamma, D0→Kˉ∗γD^0\to\bar{K}^{*}\gamma, and D0→ρ0ÎłD^0\to\rho^0\gamma. We obtain 90% CL upper limits on the branching ratios of these modes of 1.9×10−41.9\times 10^{-4}, 2.4×10−42.4\times 10^{-4}, 7.6×10−47.6\times 10^{-4} and 2.4×10−42.4\times 10^{-4} respectively.Comment: 15 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

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    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio
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