318 research outputs found

    Levels and Differentials in Maternal Mortality in Rural India:New Evidence from Sisterhood Data

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    The paper presents estimates of maternal mortality derived from the NCAER-HDI survey (1994) for rural areas of India by broad geographical regions and by some selected background characteristics of respondents. According to these estimates, maternal mortality was 544 deaths per one lakh births roughly 12 years before the survey. The maternal mortality ratio was more than 600 in eastern and north-central India, while it was between 300 and 400 in north-western and southern India. The survey data suggest that maternal mortality levels were higher among the scheduled tribes and scheduled castes and low among Muslims. The level of maternal mortality was strongly related to amenities and infrastructure available in the village. However, its relationship with poverty and educational levels of respondents was found to be weak perhaps because the characteristics of respondents were not the ideal surrogates for sisters’ attributes.Health CareMortality RateMaternal Mortality

    Demographic transition, family size and child schooling

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    This paper first presents evidence to show that in recent years there has been a substantial fall in fertility among illiterate women in India. Subsequently, using the data from the Human Development Profile Survey of 1994, it shows that child schooling among illiterate parents is inversely related to family size and positively related to contraceptive use. By connecting these two pieces of evidence, the paper argues that fertility is falling and child schooling is rising among illiterate couples because of the quantity-quality trade-off. The detrimental effect of family size on child schooling is found to be more severe on female children and on the first-born of either sex. Perhaps this is because when family size is large, these children are either not sent to school at all or withdrawn early, to supplement the family income or to look after the younger siblings. Consequently, it is argued that the first female child would particularly stand to gain from declines in fertility.EducationDemographic Transition

    Possible Discrimination between Gamma Rays and Hadrons using Cerenkov Photon Timing Measurements

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    Atmospheric \v{C}erenkov Technique is an established methodology to study TeVTeV energy gamma rays. However the challenging problem has always been the poor signal to noise ratio due to the presence of abundant cosmic rays. Several ingenious techniques have been employed to alleviate this problem, most of which are centred around the \v{C}erenkov image characteristics. However there are not many techniques available for improving the signal to noise ratio of the data from wavefront sampling observations. One such possible technique is to use the \v{C}erenkov photon arrival times and identify the species dependent characteristics in them. Here we carry out systematic monte carlo simulation studies of the timing information of \v{C}erenkov photons at the observation level. We have parameterized the shape of the \v{C}erenkov shower front as well as the pulse shapes in terms of experimentally measurable quantities. We demonstrate the sensitivity of the curvature of the shower front, pulse shape parameters as well as the photon arrival time jitter to primary species and show their efficiency in improving the signal to noise ratio. The effect of limiting the \v{C}erenkov telescope opening angle by using a circular focal point mask, onthe efficacy of the parameters has also been studied for each of the parameters. Radius of the shower front, pulse decay time and photon arrival time jitter have been found to be the most promising parameters which could be used to discriminate γ−\gamma -ray events from the background. We also find that the efficiency of the first two parameters increases with zenith angle and efficiency of pulse decay time decreases with increasing altitude of observation.Comment: 30 pages, 5 postscript figures, uses elsart.sty; To appear in Astroparticle Physic

    Simulation Studies on Arrival Time Distributions of Cherenkov Photons in Extensive Air Showers

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    Atmospheric Cherenkov technique is an established methodology to study TeV energy gamma rays. Here we carry out systematic monte carlo simulation studies of the timing information of Cherenkov photons. Extensive studies have already been carried out in this regard. Most of these are carried out at higher energies with the aim of studying the elemental composition of cosmic rays. However not much attention is paid to the species dependent signatures at TeV energies. In this work, functional fits have been carried out to the spherical Cherenkov shower fronts and the radii of curvature have been found to be equal to the height of shower maximum irrespective of the species or the observation level. Functional fits have also been carried out to describe the pulse shapes at various core distances in terms of well known probability density distribution functions (PDF). Two types of PDF's have been tried viz. gamma function and lognormal function. The variation of the pulse shape parameters as a function of primary energy, observation height and incident angles have been studied. The possibility of deriving the pulse shape parameters like the rise & decay times, full width at half maximum from the easily measurable quantities like the mean and RMS variation of photon arrival times offers a very important new technique which can be easily applied in an observation.Comment: 34 pages, 14 figures, accepted for publication in Astroparticle Physic

    Testing the Dirac equation

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    The dynamical equations which are basic for the description of the dynamics of quantum felds in arbitrary space--time geometries, can be derived from the requirements of a unique deterministic evolution of the quantum fields, the superposition principle, a finite propagation speed, and probability conservation. We suggest and describe observations and experiments which are able to test the unique deterministic evolution and analyze given experimental data from which restrictions of anomalous terms violating this basic principle can be concluded. One important point is, that such anomalous terms are predicted from loop gravity as well as from string theories. Most accurate data can be obtained from future astrophysical observations. Also, laboratory tests like spectroscopy give constraints on the anomalous terms.Comment: 11 pages. to appear in: C. L\"ammerzahl, C.W.F. Everitt, and F.W. Hehl (eds.): Gyros, Clocks, Interferometers...: Testing Relativistic Gravity in Space, Lecture Notes in Physics 562, Springer 200

    Cerenkov Photon Density Fluctuations in Extensive Air Showers

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    The details of Cerenkov light produced by a gamma ray or a cosmic ray incident at the top of the atmosphere is best studied through systematic simulations of the extensive air showers. Recently such studies have become all the more important in view of the various techniques resulting from such studies, to distinguish gamma ray initiated showers from those generated by much more abundant hadronic component of cosmic rays. We have carried out here such systematic simulation studies using CORSIKA package in order to understand the Cerenkov photon density fluctuations for 5 different energies at various core distances both for gamma ray and proton primaries incident vertically at the top of the atmosphere. Such a systematic comparison of shower to shower density fluctuations for gamma ray and proton primaries is carried out for the first time here. It is found that the density fluctuations are significantly non-Poissonian. Such fluctuations are much more pronounced in the proton primaries than gamma ray primaries at all energies. The processes that contribute significantly to the observed fluctuations have been identified. It has been found that significant contribution to fluctuations comes from photons emitted after shower maximum. The electron number fluctuations and correlated emission of Cerenkov photons are mainly responsible for the observed fluctuations.Comment: 31 pages, latex, 16 figures in ps files, Accepted for publication in "Astroparticle Physics

    Angular Resolution of the Pachmarhi Array of Cerenkov Telescopes

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    The Pachmarhi Array of Cerenkov Telescopes consists of a distributed array of 25 telescopes that are used to sample the atmospheric Cerenkov Photon showers. Each telescope consists of 7 parabolic mirrors each viewed by a single photo-multiplier tube. Reconstruction of photon showers are carried out using fast timing information on the arrival of pulses at each PMT. The shower front is fitted to a plane and the direction of arrival of primary particle initiating the shower is obtained. The error in the determination of the arrival direction of the primary has been estimated using the {\it split} array method. It is found to be ∌2.4â€Č \sim 2.4^\prime ~ for primaries of energy >3T˜eV > 3 \~TeV. The dependence of the angular resolution on the separation between the telescopes and the number of detectors are also obtained from the data.Comment: 26 pages, 11 Postscript figures; uses elsart.cls. To appear in Astroparticle Physic

    Exchange, use and conservation of animal genetic resources : policy and regulatory options

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    The aim of this report is to support informed and evidence-based decision-making by exploring a range of policy and regulatory options related to exchange, use and conservation of AnG

    Back to the future : How Scenarios of future globalisation, biotechnology, disease and climate change can inform present animal genetic resources policy development

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    With the aim of assessing how exchange practices regarding Animal Genetic Resources for Food and Agriculture (AnGR) affect the various stakeholders in the livestock sector and to identify policies and regulatory options that could guide the global exchange, use and conservation of AnGR, an exploration of future scenarios was used as a complementary approach to reviewing the current situation, as well as to identify stakeholders’ views on AnGR policy development. Four 2050 future scenarios were developed and included:1. Globalization and regionalization.2. Biotechnology development.3. Climate change and environmental degradation.4. Diseases and disasters.Having developed the scenarios, these were then used as an input point for a wide range of stakeholder consultations. The findings show that such an approach has been a useful analytical tool. The ‘far’ future perspective appeared to make people less defensive, especially in a situation where current exchange problems were not yet particularly visible or well documented. Many interviewees broadly considered that it was not a question of ‘if’ the scenarios would happen, but rather a question of ‘when’. This implies that we might do well to consider the need to respond to future challenges through the proactive development of new policies or regulations. Such a finding is partly in contrast with the general perception of the current regulatory situation being broadly acceptable
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