Electron-drift driven ion-acoustic mode in a dusty plasma with collisional effects

Instabilities of ion-acoustic waves in a dusty plasma with electron-drift, collisional, and dust charge fluctuations effects, have been investigated. The regimes are clearly marked out where the theory is applicable. The critical electron-drift velocity required to drive the instability is predicted. It is also shown that electron thermal conductivity and charged grains concentration enhance the growth of the ion-acoustic mode whereas ion-viscosity, ion-thermal conductivity, and dust charge fluctuations have a stabilizing effect.Comment: 7 pages, 3 PS-LaTeX figures (to be published in Physics of Plasmas

Ion-acoustic solitons in warm magnetoplasmas with super-thermal electrons

In this work, the phenomenon of formation of localised electrostatic waves (ESW) or soliton is considered in a warm magnetoplasma with the possibility of non-thermal electron distribution. The parameter regime considered here is relevant in case of magnetospheric plasmas. We show that deviation from a usual relaxed Maxwellian distribution of the electron population has a significant bearing in the allowed parameter regime, where these ESWs can be found. We further consider the presence of more than one electron temperature, which is inspired by recent space-based observations[key-2].Comment: 10 pages, 5 figure

Attention and regional gray matter development in very preterm children at age 12 years

Objectives: This study examines the selective, sustained, and executive attention abilities of very preterm (VPT) born children in relation to concurrent structural magnetic resonance imaging (MRI) measures of regional gray matter development at age 12 years. Methods: A regional cohort of 110 VPT (≤32 weeks gestation) and 113 full term (FT) born children were assessed at corrected age 12 years on the Test of Everyday Attention-Children. They also had a structural MRI scan that was subsequently analyzed using voxel-based morphometry to quantify regional between-group differences in cerebral gray matter development, which were then related to attention measures using multivariate methods. Results: VPT children obtained similar selective (p=.85), but poorer sustained (p=.02) and executive attention (p=.01) scores than FT children. VPT children were also characterized by reduced gray matter in the bilateral parietal, temporal, prefrontal and posterior cingulate cortices, bilateral thalami, and left hippocampus; and increased gray matter in the occipital and anterior cingulate cortices (family-wise error-corrected

Contribution of Education to Infant and Under-Five Mortality Disparities among Caste Groups in India

The level of infant and under-five mortality is high among scheduled castes (SCs) and scheduled tribes (STs) in India. This study intends to quantify the contribution of education in explaining the gap in infant and under-five mortality between SCs/STs and non-SC/ST population in India with a special focus on the effect of maternal education. We used data from three rounds of National Family Health Survey (NFHS): 1992–93, 1998–99 and 2005–06. The synthetic cohort probability approach using full birth histories was used to estimate childhood mortality. We performed binary logistic regression analysis to examine the association of infant mortality (IM) and under-five mortality (U5M) with maternal education and selected other covariates. Further, we applied Fairlie's decomposition technique to understand the relative contribution of maternal education and other covariates on IM and U5M risk between the caste groups. The IM rate (IMR) among children born to illiterate mothers is about 3 times higher than those born to mothers with higher education across all caste groups. Similarly, the U5M rate (U5MR) is 5 times higher among ST population and 3 times higher among SC population during the 14-year observation period (1992–2006). The proportions of secondary and higher educated SC and ST mothers are relatively lower than among non-SC/ST mothers. The regression analysis shows that mother’s education has a statistically significant effect on reducing IM and U5M. A number of socio-economic covariates are found associated with IM and U5M; such as father’s education, mother’s age at first birth, mother’s work status, household wealth, exposure to media and socio-economic empowerment of the mother. A decomposition analysis shows that more than 90 percent of the gap in IM and U5M between social groups is explained by the differences in the distribution of maternal education and household wealth. The findings of this study emphasise the need to provide education to disadvantaged girls and health counselling to women, particularly among SC/STs with more focus on backward regions or states, to further reduce IM and U5M in India

Hundred joules plasma focus device as a potential pulsed source for in vitro cancer cell irradiation

Indexación: Web of Science; Scopus.Plasma focus devices may arise as useful source to perform experiments aimed to study the effects of pulsed radiation on human cells in vitro. In the present work, a table top hundred joules plasma focus device, namely "PF-400J", was adapted to irradiate colorectal cancer cell line, DLD-1. For pulsed x-rays, the doses (energy absorbed per unit mass, measured in Gy) were measured using thermoluminescence detectors (TLD-100 dosimeters). The neutron fluence and the average energy were used to estimate the pulsed neutron doses. Fifty pulses of x-rays (0.12 Gy) and fifty pulses of neutrons (3.5 μGy) were used to irradiate the cancer cells. Irradiation-induced DNA damage and cell death were assessed at different time points after irradiation. Cell death was observed using pulsed neutron irradiation, at ultralow doses. Our results indicate that the PF-400J can be used for in vitro assessment of the effect of pulsed radiation in cancer cell research.http://recursosbiblioteca.unab.cl:2296/doi/pdf/10.1063/1.499465

Indirect effect of COVID-19 pandemic on maternal and neonatal health care in resource-poor setting

Background: COVID-19 pandemic has been affecting maternal and neonatal health worldwide. Our study was done to find the indirect effect of the pandemic due to associated lockdown, travel restrictions, etc. on maternal and neonatal health in a rural resource-limited area in northeast India.Methods: In this retrospective observational study, mothers of a rural, resource-limited area were enrolled if they delivered in the institution where the study was done. Hospital data regarding maternal mortality and stillbirth rate (SBR) from November 2019 till February 2020 (no-lockdown) was compared with the lockdown period (March 2020 till June 2020). Neonatal data of the no-lockdown and lockdown period were analysed and compared. All inborn and sick neonates delivered outside and admitted in the institution's neonatal unit after delivery (outborn) were included.Results: There was a 33% reduction of institutional delivery rate in Lockdown compared to the no-lockdown period. Outborn admission to the newborn unit was reduced by 41%. Stillbirth and death due to perinatal events increased significantly (relative risk (RR) 1.45, 95% CI: 0.85-2.48) amongst inborn in the lockdown period. During lockdown period maternal mortality increased from 551/100000 to 761/100000 live births (LB) (RR 1.38, 95% CI: 1.21-1.52) and NMR from 26/1000 to 32/1000 LB (RR: 1.23, 95% CI: 0.73-2.04).Conclusions: Significant adverse indirect effect of COVID-19 pandemic is observed on maternal and neonatal health. Ways for avoidance of reversion of gain achieved in NMR and MMR in the last few years in lower and middle-income countries (LMIC) needs to be urgently looked at

A Microfluidic Platform for Precision Small-volume Sample Processing and Its Use to Size Separate Biological Particles with an Acoustic Microdevice.

A major advantage of microfluidic devices is the ability to manipulate small sample volumes, thus reducing reagent waste and preserving precious sample. However, to achieve robust sample manipulation it is necessary to address device integration with the macroscale environment. To realize repeatable, sensitive particle separation with microfluidic devices, this protocol presents a complete automated and integrated microfluidic platform that enables precise processing of 0.15-1.5 ml samples using microfluidic devices. Important aspects of this system include modular device layout and robust fixtures resulting in reliable and flexible world to chip connections, and fully-automated fluid handling which accomplishes closed-loop sample collection, system cleaning and priming steps to ensure repeatable operation. Different microfluidic devices can be used interchangeably with this architecture. Here we incorporate an acoustofluidic device, detail its characterization, performance optimization, and demonstrate its use for size-separation of biological samples. By using real-time feedback during separation experiments, sample collection is optimized to conserve and concentrate sample. Although requiring the integration of multiple pieces of equipment, advantages of this architecture include the ability to process unknown samples with no additional system optimization, ease of device replacement, and precise, robust sample processing