1,756 research outputs found
Wide Range Thin-FIlm Ceramic Metal-Alloy Thermometers with Low Magnetoresistance
Many thermal measurements in high magnetic fields require thermometers that
are sensitive over a wide temperature range, are low mass, have a rapid thermal
response, and have a minimal, easily correctable magnetoresistance. Here we
report the development of a new granular-metal oxide ceramic composite (cermet)
for this purpose formed by co-sputtering of the metallic alloy nichrome
NiCr and the insulator silcon dioxide SiO. The resulting
thin films are sensitive enough to be used from room temperature down to below
100 mK in magnetic fields up to at least 35 tesla
Progesterone Receptor and Prostaglandins Mediate Luteinizing Hormone-Induced Changes in Messenger RNAs for ADAMTS Proteases in Theca Cells of Bovine Periovulatory Follicles
Little is known about the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family of extracellular proteases in ovarian follicles of nonârodent species, particularly in theca cells. In the present study, temporal changes in the abundance of mRNA encoding four ADAMTS subtypes and hormonal regulation of mRNA encoding two subtypes were investigated in theca interna cells during the periovulatory period in cattle. Gonadotropinâreleasing hormone (GnRH) was injected into animals to induce a luteinizing hormone (LH)/follicleâstimulating hormone (FSH) surge, and follicles were obtained at 0âhr postâGnRH (preovulatory) or at 6, 12, 18, or 24âhr (periovulatory). ADAMTS1, â2, â7, and â9 transcript abundance was then determined in the isolated theca interna. ADAMTS1 and â9 mRNA levels were upâregulated at 24âhr postâGnRH, whereas ADAMTS2 mRNA was higher at 12â24âhr postâGnRH and ADAMTS7 mRNA increased transiently at 12âhr postâGnRH compared to other time points. Subsequent in vitro experiments using preovulatory theca interna (0âhr postâGnRH) showed that application of LH in vitro can mimic the effects of the gonadotropin surge on mRNAs encoding ADAMTS1 and â9 and that progesterone/progesterone receptor and/or prostaglandins may regulate the levels of mRNA encoding ADAMTS1 and â9 in theca interna, downstream of the LH surge. Timeâ and subtypeâspecific changes in ADAMTS mRNA abundance in vivo, and their regulation in vitro by hormones, indicate that ADAMTS family members produced by theca cells may play important roles in follicle rupture and the accompanying tissue remodeling in cattle
Theoretical study of the two-proton halo candidate Ne including contributions from resonant continuum and pairing correlations
With the relativistic Coulomb wave function boundary condition, the energies,
widths and wave functions of the single proton resonant orbitals for Ne
are studied by the analytical continuation of the coupling constant (ACCC)
approach within the framework of the relativistic mean field (RMF) theory.
Pairing correlations and contributions from the single-particle resonant
orbitals in the continuum are taken into consideration by the resonant
Bardeen-Cooper-Schrieffer (BCS) approach, in which constant pairing strength is
used. It can be seen that the fully self-consistent calculations with NL3 and
NLSH effective interactions mostly agree with the latest experimental
measurements, such as binding energies, matter radii, charge radii and
densities. The energy of 2s orbital is slightly higher than that
of orbital, and the occupation probability of the
2s orbital is about 20%, which are in accordance with the
shell model calculation and three-body model estimation
Field-Orientation Dependent Heat Capacity Measurements at Low Temperatures with a Vector Magnet System
We describe a heat capacity measurement system for the study of the
field-orientation dependence for temperatures down to 50 mK. A "Vector Magnet"
combined with a mechanical rotator for the dewar enables the rotation of the
magnetic field without mechanical heating in the cryostat by friction. High
reproducibility of the field direction, as well as an angular resolution of
better than 0.01 degree, is obtained. This system is applicable to other kinds
of measurements which require a large sample space or an adiabatic sample
environment, and can also be used with multiple refrigerator inserts
interchangeably.Comment: 7 pages, 8 figure
Via Hexagons to Squares in Ferrofluids: Experiments on Hysteretic Surface Transformations under Variation of the Normal Magnetic Field
We report on different surface patterns on magnetic liquids following the
Rosensweig instability. We compare the bifurcation from the flat surface to a
hexagonal array of spikes with the transition to squares at higher fields. From
a radioscopic mapping of the surface topography we extract amplitudes and
wavelengths. For the hexagon--square transition, which is complex because of
coexisting domains, we tailor a set of order parameters like peak--to--peak
distance, circularity, angular correlation function and pattern specific
amplitudes from Fourier space. These measures enable us to quantify the smooth
hysteretic transition. Voronoi diagrams indicate a pinning of the domains. Thus
the smoothness of the transition is roughness on a small scale.Comment: 17 pages, 14 figure
High-Order Coupled Cluster Method Study of Frustrated and Unfrustrated Quantum Magnets in External Magnetic Fields
We apply the coupled cluster method (CCM) in order to study the ground-state
properties of the (unfrustrated) square-lattice and (frustrated)
triangular-lattice spin-half Heisenberg antiferromagnets in the presence of
external magnetic fields. Here we determine and solve the basic CCM equations
by using the localised approximation scheme commonly referred to as the
`LSUB' approximation scheme and we carry out high-order calculations by
using intensive computational methods. We calculate the ground-state energy,
the uniform susceptibility, the total (lattice) magnetisation and the local
(sublattice) magnetisations as a function of the magnetic field strength. Our
results for the lattice magnetisation of the square-lattice case compare well
to those results of QMC for all values of the applied external magnetic field.
We find a value for magnetic susceptibility of for the
square-lattice antiferromagnet, which is also in agreement with the results of
other approximate methods (e.g., via QMC). Our estimate for the
range of the extent of the () magnetisation plateau for the
triangular-lattice antiferromagnet is , which is in good
agreement with results of spin-wave theory () and
exact diagonalisations (). The CCM value for the
in-plane magnetic susceptibility per site is , which is below the
result of the spin-wave theory (evaluated to order 1/S) of .Comment: 30 pages, 13 figures, 1 Tabl
Developing effective practice learning for tomorrow's social workers
This paper considers some of the changes in social work education in the UK, particularly focusing on practice learning in England. The changes and developments are briefly identified and examined in the context of what we know about practice learning. The paper presents some findings from a small scale qualitative study of key stakeholders involved in practice learning and education in social work and their perceptions of these anticipated changes, which are revisited at implementation. The implications for practice learning are discussed
Positive Youth Development: Developing, Implementing, and Sustaining Music-Based Services for Emerging Adults Experiencing Homelessness
Research suggests that comprehensive services that consider the complex and interconnected needs of emerging adults experiencing homelessness may be more effective than interventions with a singular focus. There is little research that demonstrates how agencies that implement programs for individuals experiencing homelessness develop and sustain meaningful services for emerging adults, especially under conditions of increasing austerity. This study targets this gap in the literature by investigating how one transitional living program for emerging adults experiencing homelessness developed a music studio. Specifically, this study examines the factors and processes that were involved in developing, implementing, and sustaining the music studio. Findings suggest an ongoing organizational commitment to Positive Youth Development plays an important role
Insight into Genotype-Phenotype Associations through eQTL Mapping in Multiple Cell Types in Health and Immune-Mediated Disease
Genome-wide association studies (GWAS) have transformed our understanding of the genetics of complex traits such as autoimmune diseases, but how risk variants contribute to pathogenesis remains largely unknown. Identifying genetic variants that affect gene expression (expression quantitative trait loci, or eQTLs) is crucial to addressing this. eQTLs vary between tissues and following in vitro cellular activation, but have not been examined in the context of human inflammatory diseases. We performed eQTL mapping in five primary immune cell types from patients with active inflammatory bowel disease (n = 91), anti-neutrophil cytoplasmic antibody-associated vasculitis (n = 46) and healthy controls (n = 43), revealing eQTLs present only in the context of active inflammatory disease. Moreover, we show that following treatment a proportion of these eQTLs disappear. Through joint analysis of expression data from multiple cell types, we reveal that previous estimates of eQTL immune cell-type specificity are likely to have been exaggerated. Finally, by analysing gene expression data from multiple cell types, we find eQTLs not previously identified by database mining at 34 inflammatory bowel disease-associated loci. In summary, this parallel eQTL analysis in multiple leucocyte subsets from patients with active disease provides new insights into the genetic basis of immune-mediated diseases.This research was funded by a Wellcome Trust Clinical PhD Programme Fellowship (JEP), the NIH-Oxford-Cambridge Scholars Program (ACR), Wellcome Trust Grant 083650/Z/07/Z and MRC Grant MR/L19027/1 (KGCS), and the National Institute for Health Research Cambridge Biomedical Research Centre. KGCS is a National Institute for Health Research Senior Investigator. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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