252 research outputs found
Economische waardering en verzilvering van ecosysteembaten in Natura 2000-gebieden in Europa: Drie case studies in België en Nederland
Dual protection in sexually active women
Objective. To determine the prevalence and co-factors associated with the practice of dual protection against sexually transmitted infections (STis) and unwanted pregnancy in a cross-sectional sample of South African women.Design. Secondary analysis of cross-sectional household survey data.Methods. Statistical analysis of responses by sexually active women to the question, 'Was a condom used on the last occasion you had sex?' were obtained from the women's questionnaire of the South African Demographic and Health Survey in relation to a number of other variables.Results. (i) 10.5% of all sexually active women aged 15- 49 years used a condom at last sex and 6.3% used a condom as well as another contraceptive method; (it) condom use is more likely among younger, more educated, more affluent, and urban women, and among women who change partners more frequently; (iii) reasons for not using condoms are more likely to be associated with the personal attitudes of women or their partners than with poor knowledge of or lack of access to condoms; (iv) women who have no need or desire to prevent pregnancy are less likely to use condoms; and (v) there is a minority of sexually active women, characterised by social disadvantage, who have difficulty obtaining condoms. Conclusions. There is an urgent need for targeted programmes that increase dual protection with condoms
Application of immunoperoxidase techniques to formalin-fixed brain tissue for the diagnosis of rabies in southern Africa
Two immunoperoxidase techniques, viz. avidin-biotin complex (ABC) and peroxidase-anti-peroxidase (PAP)
procedures, were applied to paraffin-wax-embedded brain-tissue sections, from brains which had been fixed
in 10% formalin, to demonstrate the presence of rabies-virus antigen by light microscopy. These techniques
positively identified both "viverrid" and "canid" rabies-virus antigen in tissue sections of species commonly
infected with rabies virus in southern Africa, viz. the domestic dog (Canis familiaris) , yellow mongoose (Cynictus
penicillata), black-backed jackal (Canis mesomelas), bat-eared fox (Otocyon megalotus), cattle (Bos taurus),
sheep (Ovis aries) and humans.
With both of these techniques rabies-virus antigen stained as sharply demarcated, brown precipitates within the
cytoplasm of neurons. The virtual absence of background staining enabled identification of fine granules of viral
antigen, often referred to as "virus dust", within axons, dendrites and cytoplasm of the nerve cell body. Staining
with the ABC procedure produced clearer, more deeply-coloured precipitates than the PAP method.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
Tunneling Anisotropic Magnetoresistance in Co/AlOx/Au Tunnel Junctions
We observe spin-valve-like effects in nano-scaled thermally evaporated
Co/AlOx/Au tunnel junctions. The tunneling magnetoresistance is anisotropic and
depends on the relative orientation of the magnetization direction of the Co
electrode with respect to the current direction. We attribute this effect to a
two-step magnetization reversal and an anisotropic density of states resulting
from spin-orbit interaction. The results of this study points to future
applications of novel spintronics devices involving only one ferromagnetic
layer.Comment: 11 pages, 5 figures. Accpted for publishing on Nano Letters, 200
Research review: young people leaving care
This paper reviews the international research on young people leaving care. Set in the context of a social exclusion framework, it explores young people's accelerated and compressed transitions to adulthood, and discusses the development and classification of leaving care services in responding to their needs. It then considers the evidence from outcome studies and argues that adopting a resilience framework suggests that young people leaving care may fall into three groups: young people 'moving on', 'survivors' and 'victims'. In concluding, it argues that these three pathways are associated with the quality of care young people receive, their transitions from care and the support they receive after care
The diagnosis of Wesselsbron disease in a new-born lamb by immunohistochemical staining of viral antigen
Wesselsbron disease (WSL) was diagnosed in a 2-d-old lamb on a farm in the north-eastern Free State
Province where a few abortions and neonatal deaths occurred in sheep in April 1994. The liver of the lamb
was slightly swollen and orange-brown and, microscopically, it revealed single or small groups of necrotic
hepatocytes that were randomly scattered throughout the lobules. Other histopathologic hepatic lesions
included the presence of acidophilic bodies, intranuclear inclusion bodies in a few hepatocytes,
neutrophils in the parenchyma, mild Kupffer-cell and bile-ductular proliferation and infiltration of mixed
inflammatory cells in the portal tracts. Immunohistochemical staining of sections of formalin-fixed specimens
of the liver with polyclonal antibody against WSL virus revealed positive staining in acidophilic
bodies, cytoplasmic fragments of necrotic liver cells, the cytoplasm of degenerated hepatocytes and,
rarely, in intranuclear inclusions. Positive staining was also obtained in liver sections from two newborn
lambs experimentally infected with WSL virus.
The results of this investigation showed that the immunohistochemical staining of sections of formalin-fixed
liver can be used to confirm the diagnosis of WSL in new-born lambs.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
The liquid-vapor interface of an ionic fluid
We investigate the liquid-vapor interface of the restricted primitive model
(RPM) for an ionic fluid using a density-functional approximation based on
correlation functions of the homogeneous fluid as obtained from the
mean-spherical approximation (MSA). In the limit of a homogeneous fluid our
approach yields the well-known MSA (energy) equation of state. The ionic
interfacial density profiles, which for the RPM are identical for both species,
have a shape similar to those of simple atomic fluids in that the decay towards
the bulk values is more rapid on the vapor side than on the liquid side. This
is the opposite asymmetry of the decay to that found in earlier calculations
for the RPM based on a square-gradient theory. The width of the interface is,
for a wide range of temperatures, approximately four times the second moment
correlation length of the liquid phase. We discuss the magnitude and
temperature dependence of the surface tension, and argue that for temperatures
near the triple point the ratio of the dimensionless surface tension and
critical temperature is much smaller for the RPM than for simple atomic fluids.Comment: 6 postscript figures, submitted to Phys. Rev.
Electron transport across a quantum wire in the presence of electron leakage to a substrate
We investigate electron transport through a mono-atomic wire which is tunnel
coupled to two electrodes and also to the underlying substrate. The setup is
modeled by a tight-binding Hamiltonian and can be realized with a scanning
tunnel microscope (STM). The transmission of the wire is obtained from the
corresponding Green's function. If the wire is scanned by the contacting STM
tip, the conductance as a function of the tip position exhibits oscillations
which may change significantly upon increasing the number of wire atoms. Our
numerical studies reveal that the conductance depends strongly on whether or
not the substrate electrons are localized. As a further ubiquitous feature, we
observe the formation of charge oscillations.Comment: 7 pages, 7 figure
Risk stratification by residual enzyme activity after newborn screening for medium-chain acyl-CoA dehyrogenase deficiency: data from a cohort study
<p><b>Abstract</b></p> <p><b>Background</b></p> <p>Since the introduction of medium-chain acyl coenzyme A dehydrogenase (MCAD) deficiency in population newborn bloodspot screening (NBS) programs, subjects have been identified with variant <it>ACADM</it> (gene encoding MCAD enzyme) genotypes that have never been identified in clinically ascertained patients. It could be hypothesised that residual MCAD enzyme activity can contribute in risk stratification of subjects with variant <it>ACADM</it> genotypes.</p> <p><b>Methods</b></p> <p>We performed a retrospective cohort study of all patients identified upon population NBS for MCAD deficiency in the Netherlands between 2007–2010. Clinical, molecular, and enzymatic data were integrated.</p> <p><b>Results</b></p> <p>Eighty-four patients from 76 families were identified. Twenty-two percent of the subjects had a variant <it>ACADM</it> genotype. In patients with classical <it>ACADM</it> genotypes, residual MCAD enzyme activity was significantly lower (median 0%, range 0-8%) when compared to subjects with variant <it>ACADM</it> genotypes (range 0-63%; 4 cases with 0%, remainder 20-63%). Patients with (fatal) neonatal presentations before diagnosis displayed residual MCAD enzyme activities <1%. After diagnosis and initiation of treatment, residual MCAD enzyme activities <10% were associated with an increased risk of hypoglycaemia and carnitine supplementation. The prevalence of MCAD deficiency upon screening was 1/8,750 (95% CI 1/7,210–1/11,130).</p> <p><b>Conclusions</b></p> <p>Determination of residual MCAD enzyme activity improves our understanding of variant <it>ACADM</it> genotypes and may contribute to risk stratification. Subjects with variant <it>ACADM</it> genotypes and residual MCAD enzyme activities <10% should be considered to have the same risks as patients with classical <it>ACADM</it> genotypes. Parental instructions and an emergency regimen will remain principles of the treatment in any type of MCAD deficiency, as the effect of intercurrent illness on residual MCAD enzyme activity remains uncertain. There are, however, arguments in favour of abandoning the general advice to avoid prolonged fasting in subjects with variant <it>ACADM</it> genotypes and >10% residual MCAD enzyme activity.</p
Magnetic susceptibilities of diluted magnetic semiconductors and anomalous Hall-voltage noise
The carrier spin and impurity spin densities in diluted magnetic
semiconductors are considered using a semiclassical approach. Equations of
motions for the spin densities and the carrier spin current density in the
paramagnetic phase are derived, exhibiting their coupled diffusive dynamics.
The dynamical spin susceptibilities are obtained from these equations. The
theory holds for p-type and n-type semiconductors doped with magnetic ions of
arbitrary spin quantum number. Spin-orbit coupling in the valence band is shown
to lead to anisotropic spin diffusion and to a suppression of the Curie
temperature in p-type materials. As an application we derive the Hall-voltage
noise in the paramagnetic phase. This quantity is critically enhanced close to
the Curie temperature due to the contribution from the anomalous Hall effect.Comment: 18 pages, 1 figure include
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