2,157 research outputs found
Achieving equity through 'gender autonomy': the challenges for VET policy and practice
This paper is based on research carried out in an EU Fifth Framework project on 'Gender and Qualification'. The research partners from five European countries investigated the impact of gender segregation in European labour markets on vocational education and training, with particular regard to competences and qualifications. The research explored the part played by gender in the vocational education and training experiences of (i) young adults entering specific occupations in child care, electrical engineering and food preparation/service (ii) adults changing occupations
Spin-asymmetric Josephson effect
The Josephson effect is a manifestation of the macroscopic phase coherence of
superconductors and superfluids. We propose that with ultracold Fermi gases one
can realise a spin-asymmetric Josephson effect in which the two spin components
of a Cooper pair are driven asymmetrically - corresponding to driving a
Josephson junction of two superconductors with different voltages V_\uparrow
and V_\downarrow for spin up and down electrons, respectively. We predict that
the spin up and down components oscillate at the same frequency but with
different amplitudes. Our results reveal that the standard description of the
Josephson effect in terms of bosonic pair tunnelling is insufficient. We
provide an intuitive interpretation of the Josephson effect as interference in
Rabi oscillations of pairs and single particles, the latter causing the
asymmetry.Comment: Article: 4 pages, 3 figures. Supplementary material: 12 pages, 7
figure
3D reflection seismic investigation for mine planning and exploration in the Kevitsa Ni-Cu-PGE deposit, Northern Finland
A 3D reflection seismic survey was conducted over an area of about 9 km2 at the Kevitsa Ni-Cu-PGE (platinum group elements) deposit, Northern Finland. The principal objective of the survey was to image major fault and fracture zones at depth. Understanding the geometry of these zones is important for designing a steep open-pit for mining. Initial processing results suggest that the 3D seismic survey has been successful in imaging both gently dipping and steeply dipping reflections as shallow as 50 ms (or about 150 m), many of which correlate with fault systems and lithological contacts observed at the surface. Several new target areas can be identified in the seismic data that require further investigations for their mineralization potential
High Power Test on an x-Band Slotted-Iris Accelerator Structure at NLCTA
The CLIC study group at CERN has built two X-band HDS (Hybrid Damped Structure) accelerating structures for high-power testing in NLCTA at SLAC. These accelerating structures are novel with respect to their rf-design and their fabrication technique. The eleven-cell constant impedance structures, one made out of copper and one out of molybdenum, are assembled from clamped high-speed milled quadrants. They feature the same heavy higher-order-mode damping as nominal CLIC structures achieved by slotted irises and radial damping waveguides for each cell. The X-band accelerators are exactly scaled versions of structures tested at 30 GHz in the CLIC test facility, CTF3. The results of the X-band tests are presented and compared to those at 30 GHz to determine frequency scaling, and are compared to the extensive copper data from the NLC structure development program to determine material dependence and make a basic validation of the HDS design. INTRODUCTIO
Light responses and light adaptation in rat retinal rods at different temperatures
Rod responses to brief pulses of light were recorded as electroretinogram (ERG) mass potentials
across isolated, aspartate-superfused rat retinas at different temperatures and intensities of
steady background light. The objective was to clarify to what extent differences in sensitivity,
response kineticsandlight adaptationbetweenmammalianandamphibianrods can be explained
by temperature and outer-segment size without assuming functional differences in the phototransduction
molecules. Corresponding information for amphibian rods from the literature
was supplemented by new recordings from toad retina. All light intensities were expressed as
photoisomerizations per rod (Rh∗). In the rat retina, an estimated34%of incident photons at the
wavelength of peak sensitivity caused isomerizations in rods, as the (hexagonally packed) outer
segments measured 1.7 μm×22 μm and had specific absorbance of 0.016 μm−1 on average.
Fractional sensitivity (S) in darkness increased with cooling in a similar manner in rat and toad
rods, but the rat function as a whole was displaced to a ca 0.7 log unit higher sensitivity level.
This difference can be fully explained by the smaller dimensions of rat rod outer segments,
since the same rate of phosphodiesterase (PDE) activation by activated rhodopsin will produce
a faster drop in cGMP concentration, hence a larger response in rat than in toad. In the range
15–25◦C, the waveformand absolute time scale of dark-adapted dim-flash photoresponses at any
given temperature were similar in rat and toad, although the overall temperature dependence
of the time to peak (tp) was somewhat steeper in rat (Q10 ≈ 4 versus 2–3). Light adaptation
was similar in rat and amphibian rods when measured at the same temperature. The mean
background intensity that depressed S by 1 log unit at 12◦C was in the range 20–50 Rh∗ s−1 in
both, compared with ca 4500 Rh∗ s−1 in rat rods at 36◦C. We conclude that it is not necessary
to assume major differences in the functional properties of the phototransduction molecules to
account for the differences in response properties of mammalian and amphibian rods
High-Gradient Test of a Tungsten-Iris X-Band Accelerator Structure at NLCTA
The CLIC study group at CERN has built two X-band accelerating structures to be tested at SLAC in NLCTA. The structures consist of copper cells with insert irises made out of molybdenum and tungsten, clamped together and installed in a vacuum tank. These structures are exactly scaled versions from structures tested previously at 30 GHz and with short pulses (16 ns) in the CLIC Test Facility at CERN. At 30 GHz these structures reached gradients of 150 MV/m for tungsten and 195 MV/m for molybdenum. These experiments were designed to provide data on the dependence of rf breakdown on pulse length and frequency. This paper reports in particular on the high-gradient test of the tungsten-iris structure. At the shortest possible pulse length of 22 ns a gradient of 125 MV/m was reached at X-band, 20 % lower than the 150 MV/m measured at 30 GHz in the CLIC Test Facility. The pulse length dependence and the dependence of the break down rate as a function of gradient were measured in detail. The results are compared to data obtained from the molybdenum-iris experiment at X-band which took place earlier as well as to 30 GHz data
Partial hexokinase II knockout results in acute ischemia-reperfusion damage in skeletal muscle of male, but not female, mice
Cellular studies have demonstrated a protective role of mitochondrial hexokinase against oxidative insults. It is unknown whether HK protective effects translate to the in vivo condition. In the present study, we hypothesize that HK affects acute ischemia–reperfusion injury in skeletal muscle of the intact animal. Male and female heterozygote knockout HKII (HK(+/-)), heterozygote overexpressed HKII (HK(tg)), and their wild-type (WT) C57Bl/6 littermates mice were examined. In anesthetized animals, the left gastrocnemius medialis (GM) muscle was connected to a force transducer and continuously stimulated (1-Hz twitches) during 60 min ischemia and 90 min reperfusion. Cell survival (%LDH) was defined by the amount of cytosolic lactate dehydrogenase (LDH) activity still present in the reperfused GM relative to the contralateral (non-ischemic) GM. Mitochondrial HK activity was 72.6 ± 7.5, 15.7 ± 1.7, and 8.8 ± 0.9 mU/mg protein in male mice, and 72.7 ± 3.7, 11.2 ± 1.4, and 5.9 ± 1.1 mU/mg in female mice for HK(tg), WT, and HK(+/-), respectively. Tetanic force recovery amounted to 33 ± 7% for male and 17 ± 4% for female mice and was similar for HK(tg), WT, and HK(+/-). However, cell survival was decreased (p = 0.014) in male HK(+/-) (82 ± 4%LDH) as compared with WT (98 ± 5%LDH) and HK(tg) (97 ± 4%LDH). No effects of HKII on cell survival was observed in female mice (92 ± 2% LDH). In conclusion, in this mild model of acute in vivo ischemia–reperfusion injury, a partial knockout of HKII was associated with increased cell death in male mice. The data suggest for the first time that HKII mediates skeletal muscle ischemia–reperfusion injury in the intact male animal
GPs’ strategies in exploring the preschool child’s wellbeing in the paediatric consultation
Background:
Although General Practitioners (GPs) are uniquely placed to identify children with emotional, social, and behavioural problems, they succeed in identifying only a small number of them. The aim of this article is to explore the strategies, methods, and tools employed by GPs in the assessment of the preschool child’s emotional, mental, social, and behavioural health. We look at how GPs address parental care of the child in general and in situations where GPs have a particular awareness of the child.
Method:
Twenty-eight Danish GPs were purposively selected to take part in a qualitative study which combined focus-group discussions, observation of child consultations, and individual interviews with GPs.
Results:
Analysis of the data suggests that GPs have developed a set of methods, and strategies to assess the preschool child and parental care of the child. They look beyond paying narrow attention to the physical health of the child and they have expanded their practice to include the relations and interactions in the consultation room. The physical examination of the child continues to play a central role in doctor-child communication.
Conclusion:
The participating GPs’ strategies helped them to assess the wellbeing of the preschool child but they often find it difficult to share their impressions with parents
Spatial distributions of XCO2seasonal cycle amplitude and phase over northern high-latitude regions
Satellite-based observations of atmospheric carbon dioxide (CO) provide measurements in remote regions, such as the biologically sensitive but undersampled northern high latitudes, and are progressing toward true global data coverage. Recent improvements in satellite retrievals of total column-averaged dry air mole fractions of CO (X) from the NASA Orbiting Carbon Observatory 2 (OCO-2) have allowed for unprecedented data coverage of northern high-latitude regions, while maintaining acceptable accuracy and consistency relative to ground-based observations, and finally providing sufficient data in spring and autumn for analysis of satellite-observed X seasonal cycles across a majority of terrestrial northern high-latitude regions. Here, we present an analysis of X seasonal cycles calculated from OCO-2 data for temperate, boreal, and tundra regions, subdivided into 5∘ latitude by 20∘ longitude zones. We quantify the seasonal cycle amplitudes (SCAs) and the annual half drawdown day (HDD). OCO-2 SCAs are in good agreement with ground-based observations at five high-latitude sites, and OCO-2 SCAs show very close agreement with SCAs calculated for model estimates of X from the Copernicus Atmosphere Monitoring Services (CAMS) global inversion-optimized greenhouse gas flux model v19r1 and the CarbonTracker2019 model (CT2019B). Model estimates of X from the GEOS-Chem CO simulation version 12.7.2 with underlying biospheric fluxes from CarbonTracker2019 (GC-CT2019) yield SCAs of larger magnitude and spread over a larger range than those from CAMS, CT2019B, or OCO-2; however, GC-CT2019 SCAs still exhibit a very similar spatial distribution across northern high-latitude regions to that from CAMS, CT2019B, and OCO-2. Zones in the Asian boreal forest were found to have exceptionally large SCA and early HDD, and both OCO-2 data and model estimates yield a distinct longitudinal gradient of increasing SCA from west to east across the Eurasian continent. In northern high-latitude regions, spanning latitudes from 47 to 72∘ N, longitudinal gradients in both SCA and HDD are at least as pronounced as latitudinal gradients, suggesting a role for global atmospheric transport patterns in defining spatial distributions of X seasonality across these regions. GEOS-Chem surface contact tracers show that the largest X SCAs occur in areas with the greatest contact with land surfaces, integrated over 15–30 d. The correlation of XCO2 SCA with these land surface contact tracers is stronger than the correlation of X SCA with the SCA of CO fluxes or the total annual CO flux within each 5∘ latitude by 20∘ longitude zone. This indicates that accumulation of terrestrial CO flux during atmospheric transport is a major driver of regional variations in X SCA
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