147 research outputs found
Kondo behavior, ferromagnetic correlations, and crystal fields in the heavy Fermion compounds Ce3X (X=In, Sn)
We report measurements of inelastic neutron scattering, magnetic
susceptibility, magnetization, and the magnetic field dependence of the
specific heat for the heavy Fermion compounds CeIn and CeSn. The
neutron scattering results show that the excited crystal field levels have
energies = 13.2 meV, = 44.8 meV for CeIn and = 18.5 meV,
= 36.1 meV for CeSn. The Kondo temperature deduced from the
quasielastic linewidth is 17 K for CeIn and 40 K for CeSn. The low
temperature behavior of the specific heat, magnetization, and susceptibility
can not be well-described by J=1/2 Kondo physics alone, but require
calculations that include contributions from the Kondo effect, broadened
crystal fields, and ferromagnetic correlations, all of which are known to be
important in these compounds. We find that in CeIn the ferromagnetic
fluctuation makes a 10-15 % contribution to the ground state doublet entropy
and magnetization. The large specific heat coefficient in this heavy
fermion system thus arises more from the ferromagnetic correlations than from
the Kondo behavior.Comment: 8 pages, 6 figure
Pretransplant HLA typing revealed loss of heterozygosity in the major histocompatibility complex in a patient with acute myeloid leukemia
Introduction
Chromosomal abnormalities are frequent events in hematological malignancies. The degree of HLA compatibility between donor and recipient in hematopoietic stem cell transplantation is critical.
Purpose of the study
In this report, we describe an acute myeloid leukemia case with loss of heterozygosity (LOH) encompassing the entire HLA.
Materials and methods
HLA molecular typing was performed on peripheral blood (PB) and buccal swabs (BS). Chromosomal microarray analysis (CMA) was performed using a whole genome platform.
Results
Typing results on PB sample collected during blast crisis demonstrated homozygosity at the -A, -B, -C, -DR, and -DQ loci. A BS sample demonstrated heterozygosity at all loci. A subsequent PB sample drawn after count recovery confirmed heterozygosity. The CMA performed on PB samples collected during and after blast crisis revealed a large terminal region of copy-neutral LOH involving chromosome region 6p25.3p21.31, spanning approximately 35.9 Mb. The results of the CMA assay on sample collected after count recovery did not demonstrate LOH.
Conclusions
LOH at the HLA gene locus may significantly influence the donor search resulting in mistakenly choosing homozygous donors. We recommend confirming the HLA typing of recipients with hematological malignancies when homozygosity is detected at any locus by using BS samples, or alternatively from PB when remission is achieved
Vortex lattice structure in BaFe2(As0.67P0.33)2 by the small-angle neutron scattering technique
We have observed a magnetic vortex lattice (VL) in BaFe2(As_{0.67}P_{0.33})2
(BFAP) single crystals by small-angle neutron scattering (SANS). With the field
along the c-axis, a nearly isotropic hexagonal VL was formed in the field range
from 1 to 16 T, which is a record for this technique in the pnictides, and no
symmetry changes in the VL were observed. The temperature-dependence of the VL
signal was measured and confirms the presence of (non d-wave) nodes in the
superconducting gap structure for measurements at 5 T and below. The nodal
effects were suppressed at high fields. At low fields, a VL reorientation
transition was observed between 1 T and 3 T, with the VL orientation changing
by 45{\deg}. Below 1 T, the VL structure was strongly affected by pinning and
the diffraction pattern had a fourfold symmetry. We suggest that this (and
possibly also the VL reorientation) is due to pinning to defects aligned with
the crystal structure, rather than being intrinsic.Comment: 9 pages, 9 figure
Experimental feasibility of measuring the gravitational redshift of light using dispersion in optical fibers
This paper describes a new class of experiments that use dispersion in
optical fibers to convert the gravitational frequency shift of light into a
measurable phase shift or time delay. Two conceptual models are explored. In
the first model, long counter-propagating pulses are used in a vertical fiber
optic Sagnac interferometer. The second model uses optical solitons in
vertically separated fiber optic storage rings. We discuss the feasibility of
using such an instrument to make a high precision measurement of the
gravitational frequency shift of light.Comment: 11 pages, 12 figure
Interplay of gravitation and linear superposition of different mass eigenstates
The interplay of gravitation and the quantum-mechanical principle of linear
superposition induces a new set of neutrino oscillation phases. These ensure
that the flavor-oscillation clocks, inherent in the phenomenon of neutrino
oscillations, redshift precisely as required by Einstein's theory of
gravitation. The physical observability of these phases in the context of the
solar neutrino anomaly, type-II supernovae, and certain atomic systems is
briefly discussed
Happy Protest Voters: The Case of Rotterdam 1997–2009
Protest parties are on the rise in several European countries. This development is commonly attributed to a growing dissatisfaction with life and associated with declining quality of life in modern society of the lowest social strata. This explanation is tested in a cross-sectional analysis of voting and life-satisfaction in 63 districts of the city of Rotterdam in the Netherlands, where the share of protest voters increased from 10Â % in 1994 to 31Â % in 2009. Contrary to this explanation protest voting appeared not to be the most frequent in the least happy districts of Rotterdam, but in the medium happy segment. Also divergent from this explanation was that average happiness in city districts is largely independent of local living conditions, but is rather a matter of personal vulnerability in terms of education, income and health. These results fit alternative explanations in terms of mid
New Developments in Understanding Cardiovascular Disease and the Implications for Social Work
Cardiovascular disease is now viewed as an inflammatory disease. An index of chronic inflammation (viz., C-Reactive Protein) is as good a predictor of heart attacks as are fats in blood. The data suggest that stressful events are so closely associated with chronic inflammatory states, that the body’s stress response can be viewed as an inflammatory state. This paper summarizes and explains the link between stress and cardiovascular disease. Negative health outcomes, particularly for cardiovascular diseases, are higher among those of lower socio-economic status. Differential stress among socio-economic tiers is considered as an explanation for the disparities. The literature linking cardiovascular risk factors to the stressors of workplace unfairness and lack of control over working conditions is reviewed. The role of the stressor of racism in explaining the higher rates of cardiovascular mortality in African Americans is discussed. Finally, for societies with wider gaps in income between the rich and the poor, increased stress is explored as a possible explanation for the diminished health outcomes found across all socio-economic tiers. The implications for social work direct practice and macro-practice are considered
New Developments in Understanding Cardiovascular Disease and the Implications for Social Work
Diagnostic Testing of Pediatric Fevers: Meta-Analysis of 13 National Surveys Assessing Influences of Malaria Endemicity and Source of Care on Test Uptake for Febrile Children under Five Years.
In 2010, the World Health Organization revised guidelines to recommend diagnosis of all suspected malaria cases prior to treatment. There has been no systematic assessment of malaria test uptake for pediatric fevers at the population level as countries start implementing guidelines. We examined test use for pediatric fevers in relation to malaria endemicity and treatment-seeking behavior in multiple sub-Saharan African countries in initial years of implementation. We compiled data from national population-based surveys reporting fever prevalence, care-seeking and diagnostic use for children under five years in 13 sub-Saharan African countries in 2009-2011/12 (n = 105,791). Mixed-effects logistic regression models quantified the influence of source of care and malaria endemicity on test use after adjusting for socioeconomic covariates. Results were stratified by malaria endemicity categories: low (PfPR2-10<5%), moderate (PfPR2-10 5-40%), high (PfPR2-10>40%). Among febrile under-fives surveyed, 16.9% (95% CI: 11.8%-21.9%) were tested. Compared to hospitals, febrile children attending non-hospital sources (OR: 0.62, 95% CI: 0.56-0.69) and community health workers (OR: 0.31, 95% CI: 0.23-0.43) were less often tested. Febrile children in high-risk areas had reduced odds of testing compared to low-risk settings (OR: 0.51, 95% CI: 0.42-0.62). Febrile children in least poor households were more often tested than in poorest (OR: 1.63, 95% CI: 1.39-1.91), as were children with better-educated mothers compared to least educated (OR: 1.33, 95% CI: 1.16-1.54). Diagnostic testing of pediatric fevers was low and inequitable at the outset of new guidelines. Greater testing is needed at lower or less formal sources where pediatric fevers are commonly managed, particularly to reach the poorest. Lower test uptake in high-risk settings merits further investigation given potential implications for diagnostic scale-up in these areas. Findings could inform continued implementation of new guidelines to improve access to and equity in point-of-care diagnostics use for pediatric fevers
Scale-up of Malaria Rapid Diagnostic Tests and Artemisinin-Based Combination Therapy: Challenges and Perspectives in Sub-Saharan Africa.
Guido Bastiaens and colleagues describe barriers to achieving scale-up and appropriate use of rapid diagnostic tests and artemisinin-based combination therapy for malaria in sub-Saharan Africa. Please see later in the article for the Editors' Summary
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