37,999 research outputs found

    The political economy of farmers’ suicides in India: indebted cash-crop farmers with marginal landholdings explain state-level variation in suicide rates

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    Background A recent Lancet article reported the first reliable estimates of suicide rates in India. National-level suicide rates are among the highest in the world, but suicide rates vary sharply between states and the causes of these differences are disputed. We test whether differences in the structure of agricultural production explain inter-state variation in suicides rates. This hypothesis is supported by a large number of qualitative studies, which argue that the liberalization of the agricultural sector in the early-1990s led to an agrarian crisis and that consequently farmers with certain socioeconomic characteristics–cash crops cultivators, with marginal landholdings, and debts–are at particular risk of committing suicide. The recent Lancet study, however, contends that there is no evidence to support this hypothesis. Methods We report scatter diagrams and linear regression models that combine the new state-level suicide rate estimates and the proportion of marginal farmers, cash crop cultivation, and indebted farmers. Results When we include all variables in the regression equation there is a significant positive relationship between the percentage of marginal farmers, cash crop production, and indebted farmers, and suicide rates. This model accounts for almost 75% of inter-state variation in suicide rates. If the proportion of marginal farmers, cash crops, or indebted farmers were reduced by 1%, the suicide rate–suicides per 100,000 per year–would fall by 0 · 437, 0 · 518 or 0 · 549 respectively, when all other variables are held constant. Conclusions Even if the Indian state is unable to enact land reforms due to the power of local elites, interventions to stabilize the price of cash crops and relieve indebted farmers may be effective at reducing suicide rates

    ICT as learning media and research instrument: What eResearch can offer for those who research eLearning?

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    Students‘ interactions in digital learning environments are distributed over time and space, and many aspects of eLearning phenomenon cannot be investigated using traditional research approaches. At the same time, the possibility to collect digital data about students‘ online interactions and learning opens a range of new opportunities to use ICT as research tool and apply new research approaches. This symposium brings together some of the recent advancements in the area of ICT-enhanced research and aims to discuss future directions for methodological innovation in this area. The session will include four presentations that will explore different directions of ICT use for eLearning research

    Restricted dog leucocyte antigen (DLA) class II haplotypes and genotypes in Beagles

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    AbstractBeagles are commonly used in vaccine trials as part of the regulatory approval process. Genetic restriction within this breed and the impact this might have on vaccine responses are rarely considered. This study was designed to characterise diversity of dog leucocyte antigen (DLA) class II genes in a breeding colony of laboratory Beagles, whose offspring are used in vaccine studies. DLA haplotypes were determined by PCR and sequence-based typing from genomic DNA extracted from blood. Breeding colony Beagles had significantly different DLA haplotype frequencies in comparison with pet Beagles and both groups showed limited DLA diversity. Restricted DLA class II genetic variability within Beagles might result in selective antigen presentation and vaccine responses that are not necessarily representative of those seen in other dog breeds

    Making the small oblique parameters large

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    We compute the oblique parameters, including the three new parameters V V , W W and X X introduced recently by the Montreal group, for the case of one scalar multiplet of arbitrary weak isospin J J and weak hypercharge Y Y . We show that, when the masses of the heaviest and lightest components of the multiplet remain constant, but J J increases, the oblique parameter U U and the three new oblique parameters increase like J3 J^3 , while T T only increases like J J . For large multiplets with masses not much higher than mZ m_Z , the oblique parameters U U and V V may become much larger than T T and S S .Comment: 9 pages, standard LATEX, 3 figures available from the authors, report CMU-HEP93-17 and DOE-ER/40682-4

    Measurement of retinal vessel widths from fundus images based on 2-D modeling

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    Changes in retinal vessel diameter are an important sign of diseases such as hypertension, arteriosclerosis and diabetes mellitus. Obtaining precise measurements of vascular widths is a critical and demanding process in automated retinal image analysis as the typical vessel is only a few pixels wide. This paper presents an algorithm to measure the vessel diameter to subpixel accuracy. The diameter measurement is based on a two-dimensional difference of Gaussian model, which is optimized to fit a two-dimensional intensity vessel segment. The performance of the method is evaluated against Brinchmann-Hansen's half height, Gregson's rectangular profile and Zhou's Gaussian model. Results from 100 sample profiles show that the presented algorithm is over 30% more precise than the compared techniques and is accurate to a third of a pixel

    High power coupled CO2 waveguide laser array

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    A hollow-bore ridge waveguide technique for phase locking arrays of coupled CO2 rf excited waveguide lasers was demonstrated. Stable phase-locked operation of two- and three-channel arrays has been demonstrated at the 50 W output level. Preliminary experiments with a five-element array generated an output power of 95 W but phase-locked operation was not conclusively demonstrated

    New Precision Electroweak Tests of SU(5) x U(1) Supergravity

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    We explore the one-loop electroweak radiative corrections in SU(5)×U(1)SU(5)\times U(1) supergravity via explicit calculation of vacuum-polarization and vertex-correction contributions to the ϵ1\epsilon_1 and ϵb\epsilon_b parameters. Experimentally, these parameters are obtained from a global fit to the set of observables Γl,Γb,AFBl\Gamma_{l}, \Gamma_{b}, A^{l}_{FB}, and MW/MZM_W/M_Z. We include q2q^2-dependent effects, which induce a large systematic negative shift on ϵ1\epsilon_{1} for light chargino masses (m_{\chi^\pm_1}\lsim70\GeV). The (non-oblique) supersymmetric vertex corrections to \Zbb, which define the ϵb\epsilon_b parameter, show a significant positive shift for light chargino masses, which for tanβ2\tan\beta\approx2 can be nearly compensated by a negative shift from the charged Higgs contribution. We conclude that at the 90\%CL, for m_t\lsim160\GeV the present experimental values of ϵ1\epsilon_1 and ϵb\epsilon_b do not constrain in any way SU(5)×U(1)SU(5)\times U(1) supergravity in both no-scale and dilaton scenarios. On the other hand, for m_t\gsim160\GeV the constraints on the parameter space become increasingly stricter. We demonstrate this trend with a study of the m_t=170\GeV case, where only a small region of parameter space, with \tan\beta\gsim4, remains allowed and corresponds to light chargino masses (m_{\chi^\pm_1}\lsim70\GeV). Thus SU(5)×U(1)SU(5)\times U(1) supergravity combined with high-precision LEP data would suggest the presence of light charginos if the top quark is not detected at the Tevatron.Comment: LaTeX, 11 Pages+4 Figures(not included), the figures available upon request as an uuencoded file(0.4MB) or 4 PS files from [email protected], CERN-TH.7078/93, CTP-TAMU-68/93, ACT-24/9

    Non-parabolicity of the conduction band of wurtzite GaN

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    Using cyclotron resonance, we measure the effective mass, mm*, of electrons in AlGaN/GaN heterostructures with densities, n2D16×1012n_{2D}\sim 1-6\times10^{12}cm2^{-2}. From our extensive data, we extrapolate a band edge mass of (0.208±0.002)me(0.208\pm0.002) m_e. By comparing our mm* data with the results of a multi-band \textbf{k.p} calculation we infer that the effect of remote bands is essential in explaining the observed conduction band non-parabolicity (NP). Our calculation of polaron mass corrections -- including finite width and screening - suggests those to be negligible. It implies that the behavior of m(n2D)m*(n_{2D}) can be understood solely in terms of NP. Finally, using our NP and polaron corrections, we are able to reduce the large scatter in the published band edge mass values
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