507 research outputs found

    Regional variation in neonatal and post-neonatal mortality in Kenya

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    This paper seeks to establish the effect of region of residence on neonatal and post-neonatal mortality in Kenya, using the 2003 Kenya Demographic and Health Survey data. The results show significant regional variation in neonatal and post-neonatal mortality. Both neonatal and post-neonatal mortality were also found to vary significantly according to household wealth status, household water supply, and toilet facility, maternal age at birth, preceding birth interval; antenatal visits and type of place of delivery. It was only post-neonatal mortality that also varied significantly according to maternal education.The study recommends that concerted efforts be made to reduce high neonatal and post-neonatal mortality in the high mortality areas. These could entail strengthening existing family planning, child survival and HIV/AIDS programmes alongside improving households’ access to piped water supply and household hygiene practices

    Regional Variation in Initiation of Childbearing in Kenya

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    This paper seeks to establish the effect of region of residence on the initiation of child bearing in Kenya and to determine whether its effect has changed overtime. The data used is drawn from the 1998 and 2003 Kenya Demographic and Health Surveys. The Cox proportional hazard models are used to analyse the data. The results revealed that the region of residence has a significant effect on the initiation of child bearing in Kenya and that the effect remains significant even in the presence of the controls for education, age at first marriage, type of place of residence and religion. The effect of the region of residence on in the initiation of childbearing remains more or less the same across the three generations

    Sexual Initiation and Contraceptive use Among Female Adolescents in Kenya

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    This paper examines the timing of sexual initiation and contraceptive use among female adolescents in Kenya. Data are drawn from the 2003 Kenya Demographic and Health Survey. The main analytical tools are regression models. A Cox regression model is used to consider the probability of a young woman having first sex during adolescence and linear regression model to quantify the effects of a set of factors on female adolescent\u2019s age at first sexual debut. Finally, logistic regression model is used to model the probability of a sexually experienced adolescent woman using a contraceptive method. The results obtained indicate the onset of sexual activity is early and contraceptive use is fairly low and both the timing of first sex and contraceptive use are affected by a variety of factors. Despite engaging in unsafe sex practices, the majority of the adolescents do not view themselves as being at the risk of contracting HIV/AIDS. A number of recommendations are proposed

    Exponentially Small Supersymmetry Breaking from Extra Dimensions

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    The supersymmetric ``shining'' of free massive chiral superfields in extra dimensions from a distant source brane can trigger exponentially small supersymmetry breaking on our brane of order e^{-2 pi R}, where R is the radius of the extra dimensions. This supersymmetry breaking can be transmitted to the superpartners in a number of ways, for instance by gravity or via the standard model gauge interactions. The radius R can easily be stabilized at a size O(10) larger that the fundamental scale. The models are extremely simple, relying only on free, classical bulk dynamics to solve the hierarchy problem.Comment: RevTex, 1 figure. Comment on mu problem adde

    Axion-like particles as ultra high energy cosmic rays?

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    If Ultra High Energy Cosmic Rays (UHECRs) with E>4 10^{19} eV originate from BL Lacertae at cosmological distances as suggested by recent studies, the absence of the GZK cutoff can not be reconciled with Standard-Model particle properties. Axions would escape the GZK cutoff, but even the coherent conversion and back-conversion between photons and axions in large-scale magnetic fields is not enough to produce the required flux. However, one may construct models of other novel (pseudo)scalar neutral particles with properties that would allow for sufficient rates of particle production in the source and shower production in the atmosphere to explain the observations. As an explicit example for such particles we consider SUSY models with light sgoldstinos.Comment: 5 pages, 2 postscript figures, ref. adde

    Type IIA Moduli Stabilization

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    We demonstrate that flux compactifications of type IIA string theory can classically stabilize all geometric moduli. For a particular orientifold background, we explicitly construct an infinite family of supersymmetric vacua with all moduli stabilized at arbitrarily large volume, weak coupling, and small negative cosmological constant. We obtain these solutions from both ten-dimensional and four-dimensional perspectives. For more general backgrounds, we study the equations for supersymmetric vacua coming from the effective superpotential and show that all geometric moduli can be stabilized by fluxes. We comment on the resulting picture of statistics on the landscape of vacua.Comment: 48 pages, 2 figures, LaTeX. v2: references added. v3: minor comments & references adde

    Multiscale magnetic underdense regions on the solar surface: Granular and Mesogranular scales

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    The Sun is a non-equilibrium dissipative system subjected to an energy flow which originates in its core. Convective overshooting motions create temperature and velocity structures which show a temporal and spatial evolution. As a result, photospheric structures are generally considered to be the direct manifestation of convective plasma motions. The plasma flows on the photosphere govern the motion of single magnetic elements. These elements are arranged in typical patterns which are observed as a variety of multiscale magnetic patterns. High resolution magnetograms of quiet solar surface revealed the presence of magnetic underdense regions in the solar photosphere, commonly called voids, which may be considered a signature of the underlying convective structure. The analysis of such patterns paves the way for the investigation of all turbulent convective scales from granular to global. In order to address the question of magnetic structures driven by turbulent convection at granular and mesogranular scales we used a "voids" detection method. The computed voids distribution shows an exponential behavior at scales between 2 and 10 Mm and the absence of features at 5-10 Mm mesogranular scales. The absence of preferred scales of organization in the 2-10 Mm range supports the multiscale nature of flows on the solar surface and the absence of a mesogranular convective scale

    Commercial Potential of Microbial Inoculants for Sheath Blight Management and Yield Enhancement of Rice

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    Sheath blight of rice is an economically significant disease worldwide. Use of plant growth-promoting rhizobacteria (PGPR), one type of microbial inoculants, for sheath blight management and yield enhancement of rice is gaining popularity in modern agriculture due to increasing concerns with the use of chemical fungicides. Among different microbial inoculants, PGPR are used for their growth-promoting activities and managing sheath blight in rice. However, the efficacy of experimental PGPR strains is typically not consistent under field conditions due to limited knowledge of their formulations, shelf life, delivery systems, compatibility with chemicals and agronomic practices, and the mode of action. In this chapter, a general review on scope and commercial potential of various PGPR for rice sheath blight management and yield enhancement is provided. Efficacy results obtained from tests with Integral®, a current commercial product, which contains the strain Bacillus subtilis MBI600, are presented as an example of the potential for PGPR in management strategies for sheath blight

    A High Statistics Search for Ultra-High Energy Gamma-Ray Emission from Cygnus X-3 and Hercules X-1

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    We have carried out a high statistics (2 Billion events) search for ultra-high energy gamma-ray emission from the X-ray binary sources Cygnus X-3 and Hercules X-1. Using data taken with the CASA-MIA detector over a five year period (1990-1995), we find no evidence for steady emission from either source at energies above 115 TeV. The derived upper limits on such emission are more than two orders of magnitude lower than earlier claimed detections. We also find no evidence for neutral particle or gamma-ray emission from either source on time scales of one day and 0.5 hr. For Cygnus X-3, there is no evidence for emission correlated with the 4.8 hr X-ray periodicity or with the occurrence of large radio flares. Unless one postulates that these sources were very active earlier and are now dormant, the limits presented here put into question the earlier results, and highlight the difficulties that possible future experiments will have in detecting gamma-ray signals at ultra-high energies.Comment: 26 LaTeX pages, 16 PostScript figures, uses psfig.sty to be published in Physical Review
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