659 research outputs found
A haemagglutination and a haemagglutination inhibition test for bluetongue virus
Haemagglutination of bluetongue virus (BTV) was demonstrated for the first time by making use of a purified preparation of the virus. The reaction was found to be independent of variations in the pH, temperature, buffer system and origin of the erythrocytes used in the test. A haemagglutination inhibition test, subsequently developed, was demonstrated to be serotype specific. The storage of the virus for indefinite periods was facilitated by lyophilization of BTV in the presence of a low concentration of sucrose.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format
Experimental studies and nuclear model calculations on (p,xn) and (p,pxn) reactions on 85Rb from their threshold up to 100 MeV
Excitation functions were measured by the stacked-foil technique for the reactions Rb-85(p, pxn)Rb-89m,Rb-g83,Rb-82m.81 from their thresholds up to 100MeV. Nuclear model calculations were performed using the code ALICE-IPPE both on (p, xn) reactions reported earlier and (p, pxn) reactions described here. The experimental excitation curves and the results of nuclear model calculations were found to be qualitatively in agreement. With the exception of the (p, n) reaction above 40MeV, the theory appears to reproduce all the experimental data within deviations of about 50%. The cross section ratios for the isomeric pairs Sr-85m,Sr-g and Rb-84m,Rb-g are discussed qualitatively in terms of the spins of the states involved and the increasing projectile energy
Approach to the diagnosis and management of snakebite envenomation in South Africa in humans
Snakebites occur in the community, not in the Emergency Unit. As such it is important to understand the first-aid concepts and pre-hospital emergency care aspects of this neglected disease. This article will highlight the concepts for emergency care within the context of the current pre-hospital arena and in light of the recent South African Snakebite Symposium consensus meeting held in July 2022, where wilderness rescue, emergency medical services and other medical participants agreed through evidence review and consensus debate on the current best approaches to care of the snakebite victim outside the hospital environment
How do methanol masers manage to appear in the youngest star vicinities and isolated molecular clumps?
General characteristics of methanol (CH3OH) maser emission are summarized. It
is shown that methanol maser sources are concentrated in the spiral arms. Most
of the methanol maser sources from the Perseus arm are associated with embedded
stellar clusters and a considerable portion is situated close to compact HII
regions. Almost 1/3 of the Perseus Arm sources lie at the edges of optically
identified HII regions which means that massive star formation in the Perseus
Arm is to a great extent triggered by local phenomena. A multiline analysis of
the methanol masers allows us to determine the physical parameters in the
regions of maser formation. Maser modelling shows that class II methanol masers
can be pumped by the radiation of the warm dust as well as by free-free
emission of a hypercompact region hcHII with a turnover frequency exceeding 100
GHz. Methanol masers of both classes can reside in the vicinity of hcHIIs.
Modelling shows that periodic changes of maser fluxes can be reproduced by
variations of the dust temperature by a few percent which may be caused by
variations in the brightness of the central young stellar object reflecting the
character of the accretion process. Sensitive observations have shown that the
masers with low flux densities can still have considerable amplification
factors. The analysis of class I maser surveys allows us to identify four
distinct regimes that differ by the series of their brightest lines.Comment: 8 pages, 4 figures, invited presentation at IAU242 "Astrophysical
Masers and their environments
Discipline in Education
This book addresses a perennial challenge to the success of the South African education system, namely, discipline. This volume steers the interrogation of discipline in a new direction, reflecting on ways in which recent research can benefit South African schools. This includes the need for alternative discipline that will enhance education. The scholarly contribution lies in its in-depth exploration of the relevance of research findings to South African schools and to the twenty-first-century socio-political environment. For the first time, scholarly interrogation of the issue of learner discipline in South African schools draws on indigenous knowledge systems. Its post-colonial and decolonial perspectives offer an ethical and moral compass for behaviour that could contribute to the well-being of South African society (and other societies similarly afflicted by anti-social behaviour). The book offers a range of perspectives on the debates on discipline and associated issues, and should stimulate future discussions on discipline and indiscipline at a time when South Africa and many other societies engage with the effects of social and political transformation. This scholarly book is aimed at academics and researchers. The contributors include philosophers, moralists, corporativists, education law specialists, curriculum specialists, specialists in education and culture, advocates of ubuntu, and people using meta-syntheses of approaches and practices and religious practices such as a Christian ethical/moral approach to parental and school discipline. They draw on their insights into postcolonialism, the impact of indigenous knowledge, theories of agency, dysfunctionality and school underperformance. The book offers an intriguing depiction of opposing views on discipline
Discipline in Education
This book addresses a perennial challenge to the success of the South African education system, namely, discipline. This volume steers the interrogation of discipline in a new direction, reflecting on ways in which recent research can benefit South African schools. This includes the need for alternative discipline that will enhance education. The scholarly contribution lies in its in-depth exploration of the relevance of research findings to South African schools and to the twenty-first-century socio-political environment. For the first time, scholarly interrogation of the issue of learner discipline in South African schools draws on indigenous knowledge systems. Its post-colonial and decolonial perspectives offer an ethical and moral compass for behaviour that could contribute to the well-being of South African society (and other societies similarly afflicted by anti-social behaviour). The book offers a range of perspectives on the debates on discipline and associated issues, and should stimulate future discussions on discipline and indiscipline at a time when South Africa and many other societies engage with the effects of social and political transformation. This scholarly book is aimed at academics and researchers. The contributors include philosophers, moralists, corporativists, education law specialists, curriculum specialists, specialists in education and culture, advocates of ubuntu, and people using meta-syntheses of approaches and practices and religious practices such as a Christian ethical/moral approach to parental and school discipline. They draw on their insights into postcolonialism, the impact of indigenous knowledge, theories of agency, dysfunctionality and school underperformance. The book offers an intriguing depiction of opposing views on discipline
Observational cosmology using characteristic numerical relativity: Characteristic formalism on null geodesics
The characteristic formalism of numerical relativity is based on a system of
coordinates aligned with outgoing null cones. While these coordinates were
designed for studying gravitational waves, they can also be easily adapted to
model cosmological past null cones (PNCs). Similar to observational coordinates
in the observational approach to cosmology, this then provides a model that
only makes use of information causally connected to an observer. However, the
diameter distance, which is used as a radial coordinate, limits the model's
cosmological application to the region prior to the PNC refocussing. This is
because after refocussing, the diameter distance ceases to be a unique measure
of distance. This paper addresses the problem by introducing a metric based on
the Bondi-Sachs metric where the radial coordinate is replaced by an affine
parameter. A model is derived from this metric and it is then shown how an
existing numerical scheme can be adapted for simulation of cosmological PNC
behaviour. Numerical calculations on this model are found to have the same
stability and convergence properties as the standard characteristic formalism.Comment: 18 pages, 9 figures, 1 Table. arXiv admin note: some text overlap
with arXiv:some 1007.318
Multiple Sclerosis Susceptibility-Associated SNPs Do Not Influence Disease Severity Measures in a Cohort of Australian MS Patients
Recent association studies in multiple sclerosis (MS) have identified and replicated several single nucleotide polymorphism (SNP) susceptibility loci including CLEC16A, IL2RA, IL7R, RPL5, CD58, CD40 and chromosome 12q13–14 in addition to the well established allele HLA-DR15. There is potential that these genetic susceptibility factors could also modulate MS disease severity, as demonstrated previously for the MS risk allele HLA-DR15. We investigated this hypothesis in a cohort of 1006 well characterised MS patients from South-Eastern Australia. We tested the MS-associated SNPs for association with five measures of disease severity incorporating disability, age of onset, cognition and brain atrophy. We observed trends towards association between the RPL5 risk SNP and time between first demyelinating event and relapse, and between the CD40 risk SNP and symbol digit test score. No associations were significant after correction for multiple testing. We found no evidence for the hypothesis that these new MS disease risk-associated SNPs influence disease severity
Inselect: Automating the Digitization of Natural History Collections
Copyright: © 2015 Hudson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article
- …