162 research outputs found

    Timelike and Spacelike Matter Inheritance Vectors in Specific Forms of Energy-Momentum Tensor

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    This paper is devoted to the investigation of the consequences of timelike and spacelike matter inheritance vectors in specific forms of energy-momentum tensor, i.e., for string cosmology (string cloud and string fluid) and perfect fluid. Necessary and sufficient conditions are developed for a spacetime with string cosmology and perfect fluid to admit a timelike matter inheritance vector, parallel to uau^a and spacelike matter inheritance vector, parallel to xax^a. We compare the outcome with the conditions of conformal Killing vectors. This comparison provides us the conditions for the existence of matter inheritance vector when it is also a conformal Killing vector. Finally, we discuss these results for the existence of matter inheritance vector in the special cases of the above mentioned spacetimes.Comment: 27 pages, accepted for publication in Int. J. of Mod. Phys.

    Effects of Schwarzschild Geometry on Isothermal Plasma Wave Dispersion

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    The behavior of isothermal plasma waves has been analyzed near the Schwarzschild horizon. We consider a non-rotating background with non-magnetized and magnetized plasmas. The general relativistic magnetohydrodynamical equations for the Schwarzschild planar analogue spacetime with an isothermal state of the plasma are formulated. The perturbed form of these equations is linearized and Fourier analyzed by introducing simple harmonic waves. The determinant of these equations in each case leads to a complex dispersion relation, which gives complex values of the wave number. This has been used to discuss the nature of the waves and their characteristics near the horizon.Comment: 17 pages, 3 figures accepted for publication in J. Korean Physical Societ

    Complex Wave Numbers in the Vicinity of the Schwarzschild Event Horizon

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    This paper is devoted to investigate the cold plasma wave properties outside the event horizon of the Schwarzschild planar analogue. The dispersion relations are obtained from the corresponding Fourier analyzed equations for non-rotating and rotating, non-magnetized and magnetized backgrounds. These dispersion relations provide complex wave numbers. The wave numbers are shown in graphs to discuss the nature and behavior of waves and the properties of plasma lying in the vicinity of the Schwarzschild event horizon.Comment: 21 pages, 9 figures, accepted for publication Int. J. Mod. Phys.

    Acetaldehyde and hexanaldehyde from cultured white cells

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    <p>Abstract</p> <p>Background</p> <p>Noninvasive detection of innate immune function such as the accumulation of neutrophils remains a challenge in many areas of clinical medicine. We hypothesized that granulocytes could generate volatile organic compounds.</p> <p>Methods</p> <p>To begin to test this, we developed a bioreactor and analytical GC-MS system to accurately identify and quantify gases in trace concentrations (parts per billion) emitted solely from cell/media culture. A human promyelocytic leukemia cell line, HL60, frequently used to assess neutrophil function, was grown in serum-free medium.</p> <p>Results</p> <p>HL60 cells released acetaldehyde and hexanaldehyde in a time-dependent manner. The mean ± SD concentration of acetaldehyde in the headspace above the cultured cells following 4-, 24- and 48-h incubation was 157 ± 13 ppbv, 490 ± 99 ppbv, 698 ± 87 ppbv. For hexanaldehyde these values were 1 ± 0.3 ppbv, 8 ± 2 ppbv, and 11 ± 2 ppbv. In addition, our experimental system permitted us to identify confounding trace gas contaminants such as styrene.</p> <p>Conclusion</p> <p>This study demonstrates that human immune cells known to mimic the function of innate immune cells, like neutrophils, produce volatile gases that can be measured <it>in vitro </it>in trace amounts.</p

    Cold Plasma Wave Analysis in Magneto-Rotational Fluids

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    This paper is devoted to investigate the cold plasma wave properties. The analysis has been restricted to the neighborhood of the pair production region of the Kerr magnetosphere. The Fourier analyzed general relativistic magnetohydrodynamical equations are dealt under special circumstances and dispersion relations are obtained. We find the xx-component of the complex wave vector numerically. The corresponding components of the propagation vector, attenuation vector, phase and group velocities are shown in graphs. The direction and dispersion of waves are investigated.Comment: 22 pages, 18 figures, accepted for publication in Astrophys. Space Sc

    Preconception nutrition intervention improved birth length and reduced stunting and wasting in newborns in south Asia: The women first randomized controlled trial

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    South Asia has \u3e50% of the global burden of low birth weight (LBW). The objective was to determine the extent to which maternal nutrition interventions commenced before conception or in the 1st trimester improved fetal growth in this region. This was a secondary analysis of combined newborn anthropometric data for the South Asian sites (India and Pakistan) in the Women First Preconception Maternal Nutrition Trial. Participants were 972 newborn of mothers who were poor, rural, unselected on basis of nutritional status, and had been randomized to receive a daily lipid-based micronutrient supplement commencing ≥3 months prior to conception (Arm 1), in the 1st trimester (Arm 2), or not at all (Arm 3). An additional protein-energy supplement was provided if BMI/m2 or gestational weight gain was less than guidelines. Gestational age was established in the 1st trimester and newborn anthropometry obtaine

    Predictors of diarrheal mortality and patterns of caregiver health seeking behavior in in Karachi, Pakistan

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    Background: Pakistan is unfortunately among the five countries that contributed to the most deaths due to diarrhea and pneumonia in 2010. To explore factors associated with diarrheal deaths we assessed care-seeking behavior and other predictors of diarrhea-related mortality in children in selected low-income peri-urban communities of Karachi, Pakistan.Methods: A mixed methods study (qualitative and quantitative) using matched case-control design and focus group discussions with parents of children with moderate to severe diarrhea (MSD) was undertaken. Cases were children Demographic, clinical, and care-related behavioral predictors of mortality were assessed. Conditional logistic regression was performed, matched adjusted odds ratios (mOR) are reported.Results: Parents of 77 cases and 154 controls were interviewed. Cases were less likely to receive appropriate care compared to controls (mOR=0.2, 95% confidence interval (CI) 0.05-0.91). Refusal for hospital admission (OR=8.9, 95% CI 2.6-30.8), and delays in reaching the health facility (OR=3.6, 95% CI 1.0-12.9) were significant independent predictors of mortality. We found strong beliefs in traditional and spiritual healing in the population; use of both modern and traditional/spiritual treatments concurrently was common.Conclusion: Appropriate care seeking behavior predicts survival in children with diarrhea in Pakistan. There is a complex belief system relating to traditional and standard therapies. Health education for appropriate health care seeking should be implemented in order to achieve a substantial decline in diarrheal disease mortality in Pakistan
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