Low height-for-age among Limbu and Mech children and adolescents from two districts of West Bengal, India

Background: Low height-for-age (stunting) is a state of chronic undernutrition in children and adolescents. Studies reported that India has very high prevalence of stunting in children, particularly from rural and tribal communities. Objective of the present study was to record prevalence of stunting in 6 to 18 year-old boys and girls from two tribal communities (Limbu and Mech) in Darjeeling and Alipurduar districts of West Bengal, India. The study also aimed to compare height-for-age of the participants with standard growth reference curves. Methods: In this cross-sectional study, the sample comprises 1523 individuals of both sexes from Limbu (377 boys, 379 girls) and Mech (365 boys, 402 girls) communities. Height data was normalized using LMS. Results: Overall frequency of stunting among 6 to 18 year-old boys (33%) and girls (34.7%) was remarkably high. Prevalence of stunting was higher in Limbu boys (43.5%) and girls (44.6%) than their age-peers from Mech community (boys 22.2%, girls 25.4%). Height data after normalization, shows that all centile curves of height of Limbu and Mech boys and girls are consistently below the standard height-for-age reference curves of the WHO. Limbu and Mech children appear to be taller with respect to their median (50th percentile) height when compared with the median height of children in the dataset of Indian Council of Medical Research. Conclusion: High frequency stunting in Mech and limbu children was recorded and situation of girls was worse. There was a tendency of decline in prevalence of stunting with advancement of age among children

Investigation of Ultrafast Demagnetization and Gilbert Damping and their Correlation in Different Ferromagnetic Thin Films Grown Under Identical Conditions

Following the demonstration of laser-induced ultrafast demagnetization in ferromagnetic nickel, several theoretical and phenomenological propositions have sought to uncover its underlying physics. In this work we revisit the three temperature model (3TM) and the microscopic three temperature model (M3TM) to perform a comparative analysis of ultrafast demagnetization in 20-nm-thick cobalt, nickel and permalloy thin films measured using an all-optical pump-probe technique. In addition to the ultrafast dynamics at the femtosecond timescales, the nanosecond magnetization precession and damping are recorded at various pump excitation fluences revealing a fluence-dependent enhancement in both the demagnetization times and the damping factors. We confirm that the Curie temperature to magnetic moment ratio of a given system acts as a figure of merit for the demagnetization time, while the demagnetization times and damping factors show an apparent sensitivity to the density of states at the Fermi level for a given system. Further, from numerical simulations of the ultrafast demagnetization based on both the 3TM and the M3TM, we extract the reservoir coupling parameters that best reproduce the experimental data and estimate the value of the spin flip scattering probability for each system. We discuss how the fluence-dependence of inter-reservoir coupling parameters so extracted may reflect a role played by nonthermal electrons in the magnetization dynamics at low laser fluences

Direct Sulfonation of Methane at Low Pressure to Methanesulfonic Acid in the Presence of Potassium Peroxydiphosphate as the Initiator

Abstract: A high-yield, direct sulfonation of methane with SO 3 to methanesulfonic acid (MSA) is effected in sulfuric acid using potassium peroxydiphosphate (K 4 P 2 O 8 ) as the initiator. The influences of initiator concentration, temperature, CH 4 pressure, the initial concentration of SO 3 , and solvent acidity were investigated. A mechanism is proposed to explain the observed effects of reaction conditions on the conversion of SO 3 to MSA

The PPE2 protein of Mycobacterium tuberculosis translocates to host nucleus and inhibits nitric oxide production

Mycobacterium tuberculosis, the bacterium that causes tuberculosis, is one of the most successful pathogens of humans. It has evolved several adaptive skills and evasion mechanisms to hijack the immunologically educated host to suit its intracellular lifestyle. Here, we show that one of the unique PPE family member proteins of M. tuberculosis, PPE2, can limit Nitric Oxide (NO) production by inhibiting inos gene transcription. PPE2 protein has a leucine zipper DNA-binding motif and a functional nuclear localization signal. PPE2 was translocated into the macrophage nucleus via the classical importin α/β pathway where it interacted with a GATA-binding site overlapping with the TATA box of inos promoter and inhibited NO production. PPE2 prolonged intracellular survival of a surrogate bacterium M. smegmatis in vitro as well as in vivo. This information is likely to improve our knowledge of host-pathogen interactions during M. tuberculosis infection which is crucial for designing effective anti-TB therapeutics

PE11, a PE/PPE family protein of Mycobacterium tuberculosis is involved in cell wall remodeling and virulence

The role of the unique proline-glutamic acid (PE)/proline-proline-glutamic acid (PPE) family of proteins in the pathophysiology and virulence of Mycobacterium tuberculosis is not clearly understood. One of the PE family proteins, PE11 (LipX or Rv1169c), specific to pathogenic mycobacteria is found to be over-expressed during infection of macrophages and in active TB patients. In this study, we report that M. smegmatis expressing PE11 (Msmeg-PE11) exhibited altered colony morphology and cell wall lipid composition leading to a marked increase in resistance against various environmental stressors and antibiotics. The cell envelope of Msmeg-PE11 also had greater amount of glycolipids and polar lipids. Msmeg-PE11 was found to have better survival rate in infected macrophages. Mice infected with Msmeg-PE11 had higher bacterial load, showed exacerbated organ pathology and mortality. The liver and lung of Msmeg-PE11-infected mice also had higher levels of IL-10, IL-4 and TNF-α cytokines, indicating a potential role of this protein in mycobacterial virulence

The cause–effect relation of tuberculosis on incidence of diabetes mellitus

Tuberculosis (TB) is one of the oldest human diseases and is one of the major causes of mortality and morbidity across the Globe. Mycobacterium tuberculosis (Mtb), the causal agent of TB is one of the most successful pathogens known to mankind. Malnutrition, smoking, co-infection with other pathogens like human immunodeficiency virus (HIV), or conditions like diabetes further aggravate the tuberculosis pathogenesis. The association between type 2 diabetes mellitus (DM) and tuberculosis is well known and the immune-metabolic changes during diabetes are known to cause increased susceptibility to tuberculosis. Many epidemiological studies suggest the occurrence of hyperglycemia during active TB leading to impaired glucose tolerance and insulin resistance. However, the mechanisms underlying these effects is not well understood. In this review, we have described possible causal factors like inflammation, host metabolic changes triggered by tuberculosis that could contribute to the development of insulin resistance and type 2 diabetes. We have also discussed therapeutic management of type 2 diabetes during TB, which may help in designing future strategies to cope with TB-DM cases

Measurement of neutron star parameters: a review of methods for low-mass X-ray binaries

Measurement of at least three independent parameters, for example, mass, radius and spin frequency, of a neutron star is probably the only way to understand the nature of its supranuclear core matter. Such a measurement is extremely difficult because of various systematic uncertainties. The lack of knowledge of several system parameter values gives rise to such systematics. Low-mass X-ray binaries, which contain neutron stars, provide a number of methods to constrain the stellar parameters. Joint application of these methods has a great potential to significantly reduce the systematic uncertainties, and hence to measure three independent neutron star parameters accurately. Here we review the methods based on (1) thermonuclear X-ray bursts; (2) accretion-powered millisecond-period pulsations; (3) kilohertz quasi-periodic oscillations; (4) broad relativistic iron lines; (5) quiescent emissions; and (6) binary orbital motions.Comment: 30 pages, 20 figures, 1 table, An Invited and Refereed Review, will be published in "Advances in Space Research