1,015 research outputs found

    A Safe Vaccine (DV-STM-07) against Salmonella Infection Prevents Abortion and Confers Protective Immunity to the Pregnant and New Born Mice

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    Pregnancy is a transient immuno-compromised condition which has evolved to avoid the immune rejection of the fetus by the maternal immune system. The altered immune response of the pregnant female leads to increased susceptibility to invading pathogens, resulting in abortion and congenital defects of the fetus and a subnormal response to vaccination. Active vaccination during pregnancy may lead to abortion induced by heightened cell mediated immune response. In this study, we have administered the highly attenuated vaccine strain ΔpmrG-HM-D (DV-STM-07) in female mice before the onset of pregnancy and followed the immune reaction against challenge with virulent S. Typhimurium in pregnant mice. Here we demonstrate that DV-STM-07 vaccine gives protection against Salmonella in pregnant mice and also prevents Salmonella induced abortion. This protection is conferred by directing the immune response towards Th2 activation and Th1 suppression. The low Th1 response prevents abortion. The use of live attenuated vaccine just before pregnancy carries the risk of transmission to the fetus. We have shown that this vaccine is safe as the vaccine strain is quickly eliminated from the mother and is not transmitted to the fetus. This vaccine also confers immunity to the new born mice of vaccinated mothers. Since there is no evidence of the vaccine candidate reaching the new born mice, we hypothesize that it may be due to trans-colostral transfer of protective anti-Salmonella antibodies. These results suggest that our vaccine DV-STM-07 can be very useful in preventing abortion in the pregnant individuals and confer immunity to the new born. Since there are no such vaccine candidates which can be given to the new born and to the pregnant women, this vaccine holds a very bright future to combat Salmonella induced pregnancy loss

    Analysis of MAGSAT data of the Indian region

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    Progress in the development of software for reading MAGSAT data tapes and for the reduction of anomaly data, and in the preparation of data for magnetic anomaly maps is reported

    Razlučivanje Zemljine rotacije i atmosferske cikulacije Walshovim spektrima:nesinusoidalna perspektiva

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    Lambeck and Hopgood (1981, 1982) have made a comparative study of spectral characteristics of the angular momentum of atmospheric circulation and fluctuations in the Length-of-Day (LOD) data. The Fourier analysis of these data reveals a good correlation between the two processes, including a large spread of power in the range of a 20- to 70-month period. We re-examine here the above two time series by using the Walsh spectral analysis, which seems to be more appropriate for series with sharp peaks and reversals. The comparative study shows that in addition to 12-, 6- and 3-month seasonal terms, the present work discovers statistically significant (90% confidence interval) periods of (i) 26 months (hitherto weakly resolved) associated with a quasibiennial term, and (ii) 40 ± 4 months in both the data. The resolution of the spread components removes meteorological noise uncertainity from astronomical observations of LOD in the study of the excitation mechanism of solid earth

    Detection of long term modulation orbital cycles in the sea level oscillations using clean algorithm of spectral analysis

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    The need for a unified astronomical theory of sea-level changes and associated climatic variations motivates the search for Milankovich eccentricity rhythms in the global sea level variations. The available latest sea level record exhibits long term trend with superimposed higher order frequency oscillations. A new powerful spectral technique based on the one dimensional clean deconvolution algorithm, is applied to the global sea level fluctuations record of the past 30 million years. The spectrum analysis reveals statistically significant (at 90% confidence level) and “clean” cyclicity of 2000 kyr, 1250 kyr, 880 kry, 660 kyr, 416 kyr, and 260 kry. Statistically significant sea level cycles indicate possible link with climate and orbital cycles. A principal cycle (Ep) of 413 kyr corresponds to the well known orbital eccentricity cycle. The remaining higher order periodicities are integral multiples of Ep (e.g., Ep/2, 3Ep/2, 2Ep, 3Ep, 5Ep,), equivalent to those of the modulation of orbital eccentricity-precession cycles. Matching periodicities of the sea level changes and climatic rhythms, and long term modulation of orbital variations demonstrate significant role of orbital cycles in these processes and integrate the Milankovich paradigm of orbital forcing to coupled climate-sea level interactions

    Octonion Quantum Chromodynamics

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    Starting with the usual definitions of octonions, an attempt has been made to establish the relations between octonion basis elements and Gell-Mann \lambda matrices of SU(3)symmetry on comparing the multiplication tables for Gell-Mann \lambda matrices of SU(3)symmetry and octonion basis elements. Consequently, the quantum chromo dynamics (QCD) has been reformulated and it is shown that the theory of strong interactions could be explained better in terms of non-associative octonion algebra. Further, the octonion automorphism group SU(3) has been suitably handled with split basis of octonion algebra showing that the SU(3)_{C}gauge theory of colored quarks carries two real gauge fields which are responsible for the existence of two gauge potentials respectively associated with electric charge and magnetic monopole and supports well the idea that the colored quarks are dyons

    Unified Angular Momentum of Dyons

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    Unified quaternionic angular momentum for the fields of dyons and gravito-dyons has been developed and the commutation relations for dynamical variables are obtained in compact and consistent manner. Demonstrating the quaternion forms of unified fields of dyons (electromagnetic fields) and gravito-dyons (gravito-Heavisidian fields of linear gravity), corresponding quantum equations are reformulated in compact, simpler and manifestly covariant way

    Quaternion Gravi-Electromagnetism

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    Defining the generalized charge, potential, current and generalized fields as complex quantities where real and imaginary parts represent gravitation and electromagnetism respectively, corresponding field equation, equation of motion and other quantum equations are derived in manifestly covariant manner. It has been shown that the field equations are invariant under Lorentz as well as duality transformations. It has been shown that the quaternionic formulation presented here remains invariant under quaternion transformations.Comment: Key Words: Quaternion, dyons, gravito-dyons, gravi-electromagnetism. PACS No.: 04.90. +e ; 14.80. H

    Blood Pressure and Hypertension in Adults Permanently Living at High Altitude: A Systematic Review and Meta-Analysis.

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    Aryal, Nirmal, Mark Weatherall, Yadav Kumar Deo Bhatta, and Stewart Mann. Blood pressure and hypertension in adults permanently living at high altitude: a systematic review and meta-analysis. High Alt Med Biol. 17:185-193, 2016.-The objective of this study was to estimate the associations between altitude and mean blood pressure (BP) (or prevalence of hypertension [HT]) in adults who live permanently at high altitude. A literature search was conducted in December 2014 using PubMed, Scopus, and OvidSP (MedLine and EMBASE) databases to identify relevant observational studies. Inclusion criteria were reports of studies in populations permanently living at an altitude of ≥2400 m and in those 18 years or older. Meta-regression was used to estimate the association between average BP and HT and altitude. We identified 3375 articles and inclusion criteria were met for 21 reports, which included a total of 40,854 participants. Random-effects meta-regression estimated that for every 1000 m elevation the average systolic BP (SBP) (95% confidence interval [CI]) increased by 17 mmHg (0.2 to 33.8), p = 0.05 and diastolic BP (DBP) by 9.5 mmHg (0.6 to 18.4), p = 0.04 in participants with Tibetan origin. By contrast, in participants with non-Tibetan origin, average SBP decreased by 5.9 mmHg (-19.1 to 7.3), p = 0.38 and DBP by 4 mmHg (-13 to 5), p = 0.38. The odds ratios (95% CI) for the proportion of participants with HT per 1000 m increment in the altitude were 2.01 (0.37 to 11.02), p = 0.446 and 4.05 (0.07 to 244.69), p = 0.489 for Tibetan and non-Tibetan participants, respectively. Sensitivity analysis excluding two studies with older participants (≥60 years) reversed the direction of this effect in non-Tibetans with odds ratio (95% CI) of 0.10 (0.004 to 2.22) per 1000 m, p = 0.143. Overall, this review suggests weak association between BP and altitude in Tibetan origin populations

    Driving calmodulin protein towards conformational shift by changing ionization states of select residues

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    Proteins are complex systems made up of many conformational sub-states which are mainly determined by the folded structure. External factors such as solvent type, temperature, pH and ionic strength play a very important role in the conformations sampled by proteins. Here we study the conformational multiplicity of calmodulin (CaM) which is a protein that plays an important role in calcium signaling pathways in the eukaryotic cells. CaM can bind to a variety of other proteins or small organic compounds, and mediates different physiological processes by activating various enzymes. Binding of calcium ions and proteins or small organic molecules to CaM induces large conformational changes that are distinct to each interacting partner. In particular, we discuss the effect of pH variation on the conformations of CaM. By using the pKa values of the charged residues as a basis to assign protonation states, the conformational changes induced in CaM by reducing the pH are studied by molecular dynamics simulations. Our current view suggests that at high pH, barrier crossing to the compact form is prevented by repulsive electrostatic interactions between the two lobes. At reduced pH, not only is barrier crossing facilitated by protonation of residues, but also conformations which are on average more compact are attained. The latter are in accordance with the fluorescence resonance energy transfer experiment results of other workers. The key events leading to the conformational change from the open to the compact conformation are (i) formation of a salt bridge between the N-lobe and the linker, stabilizing their relative motions, (ii) bending of the C-lobe towards the N-lobe, leading to a lowering of the interaction energy between the two-lobes, (iii) formation of a hydrophobic patch between the two lobes, further stabilizing the bent conformation by reducing the entropic cost of the compact form, (iv) sharing of a Ca+2 ion between the two lobes
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