Ultraslow Electron Spin Dynamics in GaAs Quantum Wells Probed by Optically Pumped NMR

Optically pumped nuclear magnetic resonance (OPNMR) measurements were performed in two different electron-doped multiple quantum well samples near the fractional quantum Hall effect ground state nu=1/3. Below 0.5K, the spectra provide evidence that spin-reversed charged excitations of the nu=1/3 ground state are localized over the NMR time scale of ~40 microseconds. Furthermore, by varying NMR pulse parameters, the electron spin temperature (as measured by the Knight shift) could be driven above the lattice temperature, which shows that the value of the electron spin-lattice relaxation time lies between 100 microseconds and 500 milliseconds at nu=1/3.Comment: 6 pages (REVTEX), 6 eps figures embedded in text; published version; minor changes to match published versio

Chlorotellurium Compounds of Aryl Ethers

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Simplified model for solar cosmic ray exposure in manned Earth orbital flights

A simple calculational model is derived for use in estimating solar cosmic ray exposure to critical body organs in low-Earth orbit at the center of a large spherical shield of fixed thickness. The effects of the Earth's geomagnetic field, including storm conditions and the astronauts' self-shielding, are evaluated explicitly. The magnetic storm model is keyed to the planetary index K(sub p)

Oxidation products of DNA, lipid and protein among the individuals progressing towards metabolic syndrome

Oxidative stress (OS) is an early event and at the same time also a consequence in the pathology of MetS. We investigated if oxidation markers of DNA, lipid and protein increased with an increase in the risk parameters of MetS. Participants (male:70, female:90 ≥ 20 yrs) were categorized based on the number of risk factors they had as 3 Risk, 2 Risk, 1 Risk and 0 Risk for MetS and were evaluated for various oxidation markers. Protein carbonyl and advanced oxidation protein product (protein oxidation marker) differed significantly between the four study group while malondialdehyde and hydroxynonenal (lipid peroxidation marker) did not. “8-OH dG” (DNA oxidation marker) differed significantly (P< 0.05) while total antioxidant capacity did not demonstrate significant difference in its values across the group (P> 0.05). Pairwise comparison for statistically significant markers(Protein oxidation markers and 8-OH dG), demonstrated that only 8-OH dG differed significantly between 0 Risk- 3 Risk (P< 0.012) but not between 0 Risk -2 Risk and 0 Risk-1 Risk. Oxidative stress markers of DNA, lipid and protein do not increase with an increase in the risk parameters of MetS. However, it is indeed high in MetS with 3 and more risk parameters. Presence of 2 or 1 Risk also increases OS compared to 0 Risk. There is oxidative stress damage in MetS to lipid and protein but DNA damage was of significant consequence

Microalbuminuria as an overrated indicator of target organ damage in hypertension: a hospital based cross sectional study

Background:Hypertension is one of the leading causes of global burden of disease. Uncontrolled hypertension is associated with long term risk of damage to vital organs like brain, heart, kidney, blood vessels and eye i.e. Target Organ Damage (TOD). Medical scientists all over the world have been in search for an indicator which can accurately predict TOD. It is accepted that Microalbuminuria (MA) represents a more generalised vascular problem, not only confined to renal microcirculation. MA is found in a significant proportion of non-diabetic population, particularly in association with hypertension and is a predictor of cardiovascular disease. The objective of the study was to evaluate MA in hypertension and its correlation with TOD.  Methods:A Hospital based cross sectional study carried out in the department medicine of central referral hospital, a well-equipped tertiary care hospital in East Sikkim, Gangtok. 200 patients were recruited fulfilling the inclusion criteria of pre hypertension, stage 1 & 2 hypertension as defined by JNC 7 report. Patients with secondary hypertension, DM, ESRD & hyperuricemia were excluded.  MA was estimated by Immunoturbidimetry.Results:MA is associated with all TOD but significant correlation was found only with retinopathy. Out of 200 study subjects, 90 (45%) subjects had retinopathy out of which 54 (60%) had MA and 36 (40%) did not have MA. (P <0.0001)Conclusion:MA has established its position in DM where it indicates early end organ damage and heralds cardiovascular risk. Its role as a reliable indicator of TOD in non-diabetic hypertensives needs further evaluation.

ρ\rho-CP: Open Source Dislocation Density Based Crystal Plasticity Framework for Simulating Temperature- and Strain Rate-Dependent Deformation

This work presents an open source, dislocation density based crystal plasticity modeling framework, $\rho$-CP. A Kocks-type thermally activated flow is used for accounting for the temperature and strain rate effects on the crystallographic shearing rate. Slip system-level mobile and immobile dislocation densities, as well slip system-level backstress, are used as internal state variables for representing the substructure evolution during plastic deformation. A fully implicit numerical integration scheme is presented for the time integration of the finite deformation plasticity model. The framework is implemented and integrated with the open source finite element solver, Multiphysics Object-Oriented Simulation Environment (MOOSE). Example applications of the model are demonstrated for predicting the anisotropic mechanical response of single and polycrystalline hcp magnesium, strain rate effects and cyclic deformation of polycrystalline fcc OFHC copper, and temperature and strain rate effects on the thermo-mechanical deformation of polycrystalline bcc tantanlum. Simulations of realistic Voronoi-tessellated microstructures as well as Electron Back Scatter Diffraction (EBSD) microstructures are demonstrated to highlight the model's ability to predict large deformation and misorientation development during plastic deformation.Comment: 30 pages, 19 figures, 5 tables, v

How Competent Are Emergency Medicine Interns for Level 1 Milestones: Who Is Responsible?

Objectives The Next Accreditation System ( NAS ) of the Accreditation Council for Graduate Medical Education ( ACGME ) includes the implementation of developmental milestones for each specialty. The milestones include five progressively advancing skill levels, with Level 1 defining the skill level of a medical student graduate, and Level 5, that of an attending physician. The goal of this study was to query interns on how well they thought their medical school had prepared them to meet the proposed emergency medicine ( EM ) Level 1 milestones. Methods In July 2012, an electronic survey was distributed to the interns of 13 EM residency programs, asking interns whether they were taught and assessed on the proposed Level 1 milestones. Results Of possible participants, 113 of 161 interns responded (70% response rate). The interns represented all four regions of the country. The interns responded that the rates of Level 1 milestones they had been taught ranged from 61% for ultrasound to 98% for performance of focused history and physical examination. A substantial number of interns (up to 39%) reported no instruction on milestones such as patient disposition, pain management, and vascular access. Graduating medical students were less commonly assessed than taught the milestones. Skills with technology, including “explain the role of the electronic health record and computerized physician order entry,” were assessed for only 39% of interns, and knowledge ( USMLE ) and history and physical were assessed in nearly all interns. Disposition, ultrasound, multitasking, and wound management were assessed less than half of the time. Conclusions Many entering EM interns may not have had either teaching or assessment on the knowledge, skills, and behaviors making up the Level 1 milestones expected for graduating medical students. Thus, there is a potential gap in the teaching and assessment of EM interns. Based on these findings, it is unclear who will be responsible (medical schools, EM clerkships, or residency programs) for ensuring that medical students entering residency have achieved Level 1 milestones. Resumen Competencia de los Residentes de Medicina de Urgencias y Emergencias para el Nivel 1: ¿Quién es el Responsable? El próximo sistema de acreditación ( NAS , Next Accreditation System ) del Accreditation Council for Graduate Medical Education ( ACGME ) incluye la implementación de objetivos por área de desarrollo para cada especialidad. Los objetivos por área incluyen cinco niveles de habilidades progresivamente avanzadas, con un nivel 1 definido por el nivel de habilidad de un estudiante licenciado de medicina, y un nivel definido por el nivel, de un médico adjunto. El objetivo de este estudio fue preguntar a los residentes cómo pensaban que sus universidades les habían preparado para alcanzar los objetivos por área de nivel 1 propuestos en medicina de urgencias y emergencias ( MUE ). Metodología En julio de 2012, se distribuyó una encuesta electrónica a los residentes de 13 programas de residencia de MUE , preguntándoles si estaban formados y evaluados en los objetivos por área de nivel 1 propuestos. Resultados De los posibles participantes, 113 de 161 residentes (70%) respondieron. Los residentes representaban las cuatro regiones del país. Los residentes respondieron que los porcentajes de objetivos por área de nivel 1 en los que se habían formado variaron del 61% para la ecografía al 98% para la realización de la historia clínica y la exploración física. Un número importante de residentes (hasta un 39%) respondieron no formarse en objetivos por áreas tales como la ubicación del paciente, el manejo del dolor y el acceso vascular. Los estudiantes licenciados de medicina fueron menos frecuentemente evaluados que formados en los objetivos por área. Las habilidades con la tecnología, incluyendo la explicación del rol de la historia clínica electrónica y la solicitud de órdenes médicas computarizadas, se evaluaron sólo en el 39% de los residentes y el conocimiento ( USMLE , United States Medical Licensing Examination ) y la historia clínica y exploración física se evaluaron en casi todos los residentes. Es más, la ubicación, la ecografía, la multitarea y el manejo de heridas se evaluaron en menos de la mitad de las ocasiones. Conclusiones Muchos de los residentes que se inician en MUE pueden no haber tenido formación o evaluación en el conocimiento, las habilidades y los comportamientos preparatorios para los objetivos por área de nivel 1 esperados para los estudiantes licenciados de medicina. Además, hay una brecha potencial en la formación y la evaluación de los residentes de MUE . En base a estos hallazgos, no está claro quién será el responsable, las facultades de medicina, la administración de la MUE o los programas de residencia, para asegurar que los estudiantes de medicina que entren en la residencia hayan alcanzado los objetivos por área de nivel 1.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99036/1/acem12162.pd

Spectroscopic Evidence for the Localization of Skyrmions near Nu=1 as T->0

Optically pumped nuclear magnetic resonance measurements of Ga-71 spectra were carried out in an n-doped GaAs/Al0.1Ga0.9As multiple quantum well sample near the integer quantum Hall ground state Nu=1. As the temperature is lowered (down to T~0.3 K), a ``tilted plateau'' emerges in the Knight shift data, which is a novel experimental signature of quasiparticle localization. The dependence of the spectra on both T and Nu suggests that the localization is a collective process. The frozen limit spectra appear to rule out a 2D lattice of conventional skyrmions.Comment: 4 pages (REVTEX), 5 eps figures embedded in text, published versio

Transport methods and interactions for space radiations

A review of the program in space radiation protection at the Langley Research Center is given. The relevant Boltzmann equations are given with a discussion of approximation procedures for space applications. The interaction coefficients are related to solution of the many-body Schroedinger equation with nuclear and electromagnetic forces. Various solution techniques are discussed to obtain relevant interaction cross sections with extensive comparison with experiments. Solution techniques for the Boltzmann equations are discussed in detail. Transport computer code validation is discussed through analytical benchmarking, comparison with other codes, comparison with laboratory experiments and measurements in space. Applications to lunar and Mars missions are discussed