2,044 research outputs found
A method to correct differential nonlinearities in subranging analog-to-digital converters used for digital gamma-ray spectroscopy
The influence on -ray spectra of differential nonlinearities (DNL) in
subranging, pipelined analog-to-digital converts (ADCs) used for digital
-ray spectroscopy was investigated. The influence of the DNL error on
the -ray spectra, depending on the input count-rate and the dynamic
range has been investigated systematically. It turned out, that the DNL becomes
more significant in -ray spectra with larger dynamic range of the
spectroscopy system. An event-by-event offline correction algorithm was
developed and tested extensively. This correction algorithm works especially
well for high dynamic ranges
Evolution of E2 transition strength in deformed hafnium isotopes from new measurements on Hf, Hf, and Hf
The available data for E2 transition strengths in the region between
neutron-deficient Hf and Pt isotopes are far from complete. More and precise
data are needed to enhance the picture of structure evolution in this region
and to test state-of-the-art nuclear models. In a simple model, the maximum
collectivity is expected at the middle of the major shell. However, for actual
nuclei, this picture may no longer be the case, and one should use a more
realistic nuclear-structure model. We address this point by studying the
spectroscopy of Hf. We remeasure the 2^+_1 half-lives of 172,174,176Hf, for
which there is some disagreement in the literature. The main goal is to
measure, for the first time, the half-lives of higher-lying states of the
rotational band. The new results are compared to a theoretical calculation for
absolute transition strengths. The half-lives were measured using \gamma-\gamma
and conversion-electron-\gamma delayed coincidences with the fast timing
method. For the determination of half-lives in the picosecond region, the
generalized centroid difference method was applied. For the theoretical
calculation of the spectroscopic properties, the interacting boson model is
employed, whose Hamiltonian is determined based on microscopic energy-density
functional calculations. The measured 2^+_1 half-lives disagree with results
from earlier \gamma-\gamma fast timing measurements, but are in agreement with
data from Coulomb excitation experiments and other methods. Half-lives of the
4^+_1 and 6^+_1 states were measured, as well as a lower limit for the 8^+_1
states. We show the importance of the mass-dependence of effective boson charge
in the description of E2 transition rates in chains of nuclei. It encourages
further studies of the microscopic origin of this mass dependence. New data on
transition rates in nuclei from neighboring isotopic chains could support these
studies.Comment: 16 pages, 16 figures, 7 tables; Abstract shortened due to character
limi
A Novel Mouse Fgfr2 Mutant, Hobbyhorse (hob), Exhibits Complete XY Gonadal Sex Reversal
The secreted molecule fibroblast growth factor 9 (FGF9) plays a critical role in testis determination in the mouse. In embryonic gonadal somatic cells it is required for maintenance of SOX9 expression, a key determinant of Sertoli cell fate. Conditional gene targeting studies have identified FGFR2 as the main gonadal receptor for FGF9 during sex determination. However, such studies can be complicated by inefficient and variable deletion of floxed alleles, depending on the choice of Cre deleter strain. Here, we report a novel, constitutive allele of Fgfr2, hobbyhorse (hob), which was identified in an ENU-based forward genetic screen for novel testis-determining loci. Fgr2hob is caused by a C to T mutation in the invariant exon 7, resulting in a polypeptide with a mis-sense mutation at position 263 (Pro263Ser) in the third extracellular immunoglobulin-like domain of FGFR2. Mutant homozygous embryos show severe limb and lung defects and, when on the sensitised C57BL/6J (B6) genetic background, undergo complete XY gonadal sex reversal associated with failure to maintain expression of Sox9. Genetic crosses employing a null mutant of Fgfr2 suggest that Fgr2hob is a hypomorphic allele, affecting both the FGFR2b and FGFR2c splice isoforms of the receptor. We exploited the consistent phenotype of this constitutive mutant by analysing MAPK signalling at the sex-determining stage of gonad development, but no significant abnormalities in mutant embryos were detected
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Plasma Spraying of Kaolinite for Preparing Reactive Alumino-Silicate Glass Coatings
Thermally treated kaolinite is used to develop a range of alumino-silicate-based precursor materials but its behavior during plasma spraying has not been well-researched. In this study, two types of kaolinite samples were investigated in the form of low defect (KGa-1b) and high defect (KGa-2) varieties. The extreme temperatures of the plasma stream (up to 20 000 K) induced flash melting to produce a highly porous alumino-silicate glass without any crystallization of new AlâSi oxide minerals. The glass is comprised largely of intact or deformed spheres (average diameters 1.14â1.44 ÎŒm), which indicates rapid quenching and solidification before impact. The subspherical structures contain up to 40 % closed pore space caused by the rapid escape of water during melting. The low-density, porous alumino-silicate glass coatings with predicted specific surface areas (>0.95 m2/g) and hardnesses >1.8 GPa represent a potentially reactive but physically stable substrate ideal for further chemical functionalization
Origin and significance of clayâcoated fractures in mudrock fragments of the SAFOD borehole (Parkfield, California)
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95148/1/grl21674.pd
A womenâs worker in court: A more appropriate service for women defendants with mental health issues?
Aims
Court liaison services aim to reduce mental illness in prison through early treatment and/or diversion into care of defendants negotiating their court proceedings. However, liaison services may inadvertently contribute to gender inequalities in mental health in the prison system. This is because women often do not access liaison services. This is attributed to services failing to recognise that women have different needs from men. To address this, it is essential that the needs of women in contact with the criminal justice system (CJS) are clearly articulated. However, there is a dearth of research that considers womenâs needs at this stage of their journey through the CJS. This paper aims to identify these needs before women enter prison. It does so through an analysis of a pilot Womenâs Support Service based at a Magistratesâ Court, a response to concerns that women were not accessing the local liaison service. Characteristics of women defendants attending the service are described, specifically their home environments, general and mental health needs. Their support needs when in contact with the CJS and the links the service must forge with local community organisations to provide this, are also presented. This knowledge will develop/ tailor existing services available to women defendants to improve their access to these and optimise the benefits they can derive from them.
Methods
Proformas were completed by a women specialist worker for 86 women defendants assessed in 4 months. Information was collected on characteristics including education, domestic violence, accommodation, physical and mental health.. This specialist worker recorded the range of needs identified by defendants at assessment and the services to which women were referred.
Results
Access to the Womenâs Support Service is high, with only 11.3% of women refusing to use the service. Women attending have high levels of physical and mental health issues. Their mental health issues have not being addressed prior to accessing the service. Women often come from single households and environments high in domestic abuse. Women have multiple needs related to benefits, finance, housing, domestic abuse, education and career guidance. These are more frequent than those that explicitly link to mental health. The womenâs worker providing the service referred women to 68 services from a wide variety of statutory and voluntary organisations.
Conclusions
The Womenâs Support Service is accessed by a higher number of women, many more than access the local liaison service. It is suggested that this is due to their multiple and gender specific needs being adequately addressed by the former service and the organisations to whom they are referred. Mental health needs may also be secondary to other more basic needs, that makes the generic service provided but the Womenâs support Service more appropriate than a liaison service that deals with mental health support alone
Identification of mixed-symmetry states in an odd-mass nearly-spherical nucleus
The low-spin structure of 93Nb has been studied using the (n,n' gamma)
reaction at neutron energies ranging from 1.5 to 3.0 MeV and the 94Zr(p,2n
gamma)93Nb reaction at bombarding energies from 11.5 to 19 MeV. States at
1779.7 and 1840.6 keV, respectively, are proposed as mixed-symmetry states
associated with the coupling of a proton hole in the p_1/2 orbit to the 2+_1,ms
state in 94Mo. These assignments are derived from the observed M1 and E2
transition strengths to the symmetric one-phonon states, energy systematics,
spins and parities, and comparison with shell model calculations.Comment: 5 pages, 3 figure
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