Magnetic Vortex Core Dynamics in a Ferromagnetic Dot

We report direct imaging by means of x-ray photoemission electron microscopy of the dynamics of magnetic vortices confined in micron-size circular Permalloy dots that are 30 nm thick. The vortex core positions oscillate on a 10-ns timescale in a self-induced magnetostatic potential well after the in-plane magnetic field is turned off. The measured oscillation frequencies as a function of the aspect ratio (thickness/radius) of the dots are in agreement with theoretical calculations presented for the same geometry.Comment: 18 pages including 4 figure

Survey of Research Approaches Utilised in The Scholarship of Teaching and Learning Publications

The Scholarship of Teaching and Learning (SoTL) has been described as the fastest growing academic development movement in higher education. As this field of inquiry matures, there is a need to understand how SoTL research is conducted. The purpose of our study was to inform this debate by investigating research approaches used in SoTL publications. We analysed 223 empirical research studies published from 2012 to 2014 in three explicitly focused SoTL journals. We classified the studies as either qualitative, quantitative, or mixed methods using an analytical framework devised from existing literature on research methods. We found that the use of the three research designs was fairly evenly distributed across the papers examined: qualitative (37.2%), quantitative (29.6%), and mixed methods (33.2%). However, there was an over-reliance on data collection from a single source in 83.9% of papers analysed, and this source was primarily students. There was some, but limited, evidence of the use of triangulation through the use of multiple data collection instruments (e.g. survey, assessment tasks, grade databases). Similarly, only one-third of publications classified as mixed methods integrated the analysis and interpretation of the qualitative and quantitative data equally within the study. We conclude that current SoTL research is characterised by methodological pluralism but could be advanced through inclusion of more diverse approaches, such as close reading, and adoption of strategies known to enhance the quality of research, for example, triangulation and visual representation

A Murine Model of Lyme Disease Demonstrates That Borrelia burgdorferi Colonizes the Dura Mater and Induces Inflammation in the Central Nervous System

Lyme disease, which is caused by infection with Borrelia burgdorferi and related species, can lead to inflammatory pathologies affecting the joints, heart, and nervous systems including the central nervous system (CNS). Inbred laboratory mice are effective models for characterizing B. burgdorferi infection kinetics and host immune responses in joints and heart tissues; however, similar studies are lacking in the CNS of these animals. Here we characterize the kinetics of B. burgdorferi colonization and associated immune responses in the CNS of infected C3H mice during early and subacute infection. B. burgdorferi colonized the dura mater following needle or tick challenge, and induced expression of inflammatory cytokines and a robust IFN response as well as histopathological changes. A sterile IFN response in the absence of B. burgdorferi or inflammatory cytokines was unique to the brain parenchyma, and could provide insights into the mechanism of inflammatory CNS pathology associated with this important pathogen

Prevalence of vaginitis, syphilis and HIV infection in women in the Orange Free State

Objective. To determine the prevalence of vaginitis, syphilis and HIV infection in women in the Orange Free State.Method. By cluster sampling, 120 rural (farm) and 120 urban (local authority) clusters, each containing 4 women, were selected. Women aged 18 - 49 years who were included in the study had a cervical smear taken for cytological evaluation and blood specimens drawn for syphilis and HIV testing; they were questioned on their knowledge of AIDS.Results. Trichomonas vaginalis vaginitis was present in 27,4% of the rural women and 29,6% of the urban women, Gardnerella vaginalis in 7,2% and 8,4% and Candida spp. in 2,6% and 6,7% respectively. Syphilis serology was positive in 12% of rural and 16% of urban women. HIV was present in 0,4% of rural and 1,5% of urban women. Ninety per cent of urban women and 74% of rural women knew AIDS was a sexually transmitted disease.Conclusions. The prevalences of trichomonas vaginitis and syphilis were unusually high, while HIV positivity was similar to that in other reports in South Africa

Marketing graduate employability: understanding the tensions between institutional practice and external messaging

Do the narratives of employability constructed by higher education institutions for marketing purposes differ from the conceptualisation and/or the realisation of employability within those institutions? The study reported here drew on interviews with 16 senior academic and student support staff who were tasked with developing student employability at one of nine institutions in Australia, Canada and the UK. We employed Holmes’ conceptions of employability as possessional, positional or processual to analyse how the interviewees conceptualised employability and the presentation of employability on the institutional websites. We found that most institutions’ employability marketing narratives were inconsistent with the institutional practice reported by staff. We explain this tension in the context of two competing characterisations of higher education: a university-student transaction view; and a learning view. We emphasise the need for internal and external narratives to align and advocate the need for engagement in a constructive and critical dialogue involving all stakeholders

Fundamental Parameters of He-Weak and He-Strong Stars

We carried out low resolution spectroscopic observations in the wavelength range 3400-4700 A of 20 He-weak and 8 He-strong stars to determine their fundamental parameters by means of the Divan-Chalonge-Barbier (BCD) spectrophotometric system. For a few He-weak stars we also estimate the effective temperatures and the angular diameters by integrating absolute fluxes observed over a wide spectral range. Non-LTE model calculations are carried out to study the influence of the He/H abundance ratio on the emergent radiation of He-strong stars and on their Teff determination. We find that the effective temperatures, surface gravities and bolometric absolute magnitudes of He-weak stars estimated with the BCD system and the integrated flux method are in good agreement between each other, and they also agree with previous determinations based on several different methods. The mean discrepancy between the visual absolute magnitudes derived using the Hipparcos parallaxes and the BCD values is on average 0.3 mag for He-weak stars, while it is 0.5 mag for He-strong stars. For He-strong stars, we note that the BCD calibration, based on stars in the solar environment, leads to overestimated values of Teff. By means of model atmosphere calculations with enhanced He/H abundance ratios we show that larger He/H ratios produce smaller BD which naturally explains the Teff overestimation. We take advantage of these calculations to introduce a method to estimate the He/H abundance ratio in He-strong stars. The BD of HD 37479 suggests that the Teff of this star remains fairly constant as the star spectrum undergoes changes in the intensity of H and He absorption lines. Data for the He-strong star HD 66765 are reported for the first time.Comment: Accepted for publication in A&

Borrelia burgdorferi Adhere to Blood Vessels in the Dura Mater and are Associated with Increased Meningeal T Cells during Murine Disseminated Borreliosis

Borrelia burgdorferi, the causative agent of Lyme disease, is a vector-borne bacterial infection that is transmitted through the bite of an infected tick. If not treated with antibiotics during the early stages of infection, disseminated infection can spread to the central nervous system (CNS). In non-human primates (NHPs) it has been demonstrated that the leptomeninges are among the tissues colonized by B. burgdorferi spirochetes. Although the NHP model parallels aspects of human borreliosis, a small rodent model would be ideal to study the trafficking of spirochetes and immune cells into the CNS. Here we show that during early and late disseminated infection, B. burgdorferi infects the meninges of intradermally infected mice, and is associated with concurrent increases in meningeal T cells. We found that the dura mater was consistently culture positive for spirochetes in transcardially perfused mice, independent of the strain of B. burgdorferi used. Within the dura mater, spirochetes were preferentially located in vascular regions, but were also present in perivascular, and extravascular regions, as late as 75 days post-infection. At the same end-point, we observed significant increases in the number of CD3+ T cells within the pia and dura mater, as compared to controls. Flow cytometric analysis of leukocytes isolated from the dura mater revealed that CD3+ cell populations were comprised of both CD4 and CD8 T cells. Overall, our data demonstrate that similarly to infection in peripheral tissues, spirochetes adhere to the dura mater during disseminated infection, and are associated with increases in the number of meningeal T cells. Collectively, our results demonstrate that there are aspects of B. burgdorferi meningeal infection that can be modelled in laboratory mice, suggesting that mice may be useful for elucidating mechanisms of meningeal pathogenesis by B. burgdorferi

A generalizable framework for multi-scale auditing of digital learning provision in higher education

It is increasingly important that higher education institutions can audit and evaluate the scope and efficacy of their digital learning resources across various scales. To-date there has been little effort to address this need for a validated, appropriate and simple to execute method that will facilitate such an audit; whether it be at the scale of an individual programme, department, faculty or institution. The data are of increasing value to ensure institutions maintain progress and equity in the student experience as well as for deployment and interpretation of learning analytics. This study presents a generalizable framework for auditing digital learning provision in higher education curricula. The framework is contextualized using a case study in which the audit is conducted across a single faculty in a research-intensive U.K. university. This work provides academics and higher education administrators with key principles and considerations as well as example aims and outcomes