Hippopede curves for modelling radial spin waves in an azimuthal graded magnonic landscape

This is the final version. Available from the American Physical Society via the DOI in this record. We propose a mathematical model for describing radially propagating spin waves emitted from the core region in a magnetic patch with n vertices in a magnetic vortex state. The azimuthal anisotropic propagation of surface spin waves (SSW) into the domain, and confined spin waves (or Winter's Magnons, WM) in domain walls increases the complexity of the magnonic landscape. In order to understand the spin wave propagation in these systems, we first use an approach based on geometrical curves called 'hippopedes', however it provides no insight into the underlying physics. Analytical models rely on generalized expressions from the dispersion relation of SSW with an arbitrary angle between magnetization M and wavenumber k. The derived algebraic expression for the azimuthal dispersion is found to be equivalent to that of the 'hippopede' curves. The fitting curves from the model yield a spin wave wavelength for any given azimuthal direction, number of patch vertices and excitation frequency, showing a connection with fundamental physics of exchange dominated surface spin waves. Analytical results show good agreement with micromagnetic simulations and can be easily extrapolated to any n-corner patch geometry.Engineering and Physical Sciences Research Council (EPSRC

Graded index confined spin waves in a mixed Bloch-Néel domain wall

This is the final version. Available from the American Physical Society via the DOI in this recordWe propose a mathematical model for describing propagating confined modes in domain walls of intermediate angle α ( 0 < α < π / 2 radians ) between domains. The model is obtained from the linearized Bloch equations of motion and under reasonable assumptions that can apply to the scenario of a thick (80 nm) magnetic patch, which simplifies the calculations without a high impact on the model accuracy. The model shows that there is a clear dependence of the local wave number of the confined spin wave on the local angle of domain magnetization with respect to the wall and on the excitation magnetic field frequency. From this model, we can define a local mode index in the wall as a function of such angle and excitation frequency. Therefore, the model can be applied to 1D propagating modes, although it also has physical implications for 2D scenarios where a domain wall merges with a saturated magnetic region. Micromagnetic simulations are in good agreement with the predictions of the model. Our model can also give insight on the effects that curved edge structures may have on the propagating characteristics of spin waves bounded in domain walls.Engineering and Physical Sciences Research Council (EPSRC

Discovery of the progenitor of the type Ia supernova 2007on

Type Ia supernovae are exploding stars that are used to measure the accelerated expansion of the Universe and are responsible for most of the iron ever produced. Although there is general agreement that the exploding star is a white dwarf in a binary system, the exact configuration and trigger of the explosion is unclear, which could hamper their use for precision cosmology. Two families of progenitor models have been proposed. In the first, a white dwarf accretes material from a companion until it exceeds the Chandrasekhar mass, collapses and explodes. Alternatively, two white dwarfs merge, again causing catastrophic collapse and an explosion. It has hitherto been impossible to determine if either model is correct. Here we report the discovery of an object in pre-supernova archival X-ray images at the position of the recent type Ia supernova (2007on) in the elliptical galaxy NGC 1404. Deep optical images (also archival) show no sign of this object. From this we conclude that the X-ray source is the progenitor of the supernova, which favours the accretion model for this supernova, although the host galaxy is older (6-9 Gyr) than the age at which the explosions are predicted in the accreting models.Comment: Published in Nature See also the two follow-up papers: Roelofs, Bassa, Voss, Nelemans Nelemans, Voss, Roelofs, Bassa both on astro-ph 02/15/0

Podoconiosis in East and West Gojam Zones, Northern Ethiopia

Background: Podoconiosis is a neglected tropical disease (NTD) that is prevalent in red clay soil-covered highlands of tropical Africa, Central and South America, and northern India. It is estimated that up to one million cases exist in Ethiopia. This study aimed to estimate the prevalence of podoconiosis in East and West Gojam Zones of Amhara Region in northern Ethiopia. Methodology/Principal Findings: A cross-sectional household survey was conducted in Debre Eliyas and Dembecha woredas (districts) in East and West Gojam Zones, respectively. The survey covered all 17,553 households in 20 kebeles (administrative subunits) randomly selected from the two woredas. A detailed structured interview was conducted on 1,704 cases of podoconiosis identified in the survey. Results: The prevalence of podoconiosis in the population aged 15 years and above was found to be 3.3% (95% CI, 3.2% to 3.6%). 87% of cases were in the economically active age group (15–64 years). On average, patients sought treatment five years after the start of the leg swelling. Most subjects had second (42.7%) or third (36.1%) clinical stage disease, 97.9% had mossy lesions, and 53% had open wounds. On average, patients had five episodes of acute adenolymphangitis (ALA) per year and spent a total of 90 days per year with ALA. The median age of first use of shoes and socks were 22 and 23 years, respectively. More men than women owned more than one pair of shoes (61.1% vs. 50.5%; x2 = 11.6 p = 0.001). At the time of interview, 23.6% of the respondents were barefoot, of whom about two-thirds were women. Conclusions: This study showed high prevalence of podoconiosis and associated morbidities such as ALA, mossy lesions and open wounds in northern Ethiopia. Predominance of cases at early clinical stage of podoconiosis indicates the potential for reversing the swelling and calls for disease prevention interventions

Training health providers to address unhealthy alcohol use in primary care: a cross-sectional, multicenter study.

Background: Health professionals’ training is a key element to address unhealthy alcohol use in Primary Care (PC). Education about alcohol use can be effective in improving PC provider’s knowledge and skills addressing alcoholrelated problems. The aim of the study was to evaluate the training of health professionals to address unhealthy alcohol use in PC. Methods: An observational, descriptive, cross-sectional, multicenter study was performed. Location: PC centres of the Spanish National Health System (SNHS). Participants: Family physicians, residents and nurses completed an online questionnaire that inquired about their training (none, basic, medium or advanced), knowledge and preventive practices aimed at reducing unhealthy alcohol use. The study population was recruited via random sampling, stratified by the regions of the SNHS’s PC centre, and by email invitation to members of two Spanish scientific societies of Family Medicine. Results: A total of 1760 professionals participated in the study. Sixty-seven percent (95% CI: 67.5–71.8) reported not having received specific training to address unhealthy alcohol use, 30% (95% CI: 27.4–31.7) reported having received basic training, and 3% (95% CI: 2.3–4.0) medium/advanced training. The training received was greater in younger providers (p < 0.001) who participated in the PAPPS (Preventive Activities and Health Promotion Programme) (p < 0.001). Higher percentages of providers with intermediate or advanced training reported performing screening for unhealthy alcohol use (p < 0.001), clinical assessment of alcohol consumption (p < 0.001), counselling of patients to reduce their alcohol intake (p < 0.001) or to abstain, in the cases of pregnant women and drivers (p < 0.001). Conclusion: Our study reveals a low level of training among Spanish PC providers to address unhealthy alcohol use. A higher percentage of screening, clinical assessment and counselling interventions aimed at reducing unhealthy alcohol use was reported by health professionals with an intermediate or advanced level of training.post-print565 K

Time-domain imaging of curling modes in a confined magnetic vortex and a micromagnetic study exploring the role of spiral spin waves emitted by the core

This is the final version. Available from the American Physical Society via the DOI in this recordThe curling spin wave modes of a ferromagnetic vortex confined to a microscale disk have been directly imaged in response to a microwave field excitation using time-resolved scanning Kerr microscopy. Micromagnetic simulations have been used to explore the interaction of gyrotropic vortex core dynamics with the curling modes observed in the region of circulating in-plane magnetization. Hybridization of the fundamental gyrotropic mode with the degenerate, lowest frequency, azimuthal modes has previously been reported to lead to their splitting and counterpropagating motion, as we observe in our spectra and measured images. The curling nature of the modes can be ascribed to asymmetry in the static and dynamic magnetization across the disk thickness, but here we also present evidence that spiral spin waves emitted by the core can influence the spatial character of higher frequency curling modes for which hybridization is permitted only with gyrotropic modes of the same sense of azimuthal motion. While it is challenging to identify if such modes are truly hybridized from the mode dispersion in a confined disk, our simulations reveal that spiral spin waves from the core may act as mediators of the interaction between the core dynamics and azimuthal modes, enhancing the spiral nature of the curling mode. At higher frequency, modes with radial character only do not exhibit marked curling, but instead show evidence of interaction with spin waves generated at the edge of the disk. The measured spatiotemporal character of the observed curling modes is accurately reproduced by our simulations, which reveal the emission of propagating short-wavelength spiral spin waves from both core and edge regions of the disk. Our simulations suggest that the propagating modes are not inconsequential, but may play a role in the dynamic overlap required for hybridization of modes of the core and in-plane magnetized regions. These results are of importance to the fields of magnonics and spintronics that aim to utilize spin wave emission from highly localized, nanoscale regions of nonuniform magnetization, and their subsequent interaction with modes that may be supported nearby.Engineering and Physical Sciences Research Council (EPSRC

Different profiles of immune reconstitution in children and adults with HIV-infection after highly active antiretroviral therapy

BACKGROUND: Recent advances in characterizing the immune recovery of HIV-1-infected people have highlighted the importance of the thymus for peripheral T-cell diversity and function. The aim of this study was to investigate differences in immune reconstitution profiles after highly active antiretroviral therapy (HAART) between HIV-children and adults. METHODS: HIV patients were grouped according to their previous clinical and immunological status: 9 HIV-Reconstituting-adults (HIV-Rec-adults) and 10 HIV-Reconstituting-children (HIV-Rec-children) on HAART with viral load (VL) ≤400 copies/ml and CD4(+ )≥500 cells/μL at least during 6 months before the study and CD4(+ )≤300 cells/μL anytime before. Fifteen healthy-adults and 20 healthy-children (control subjects) were used to calculate Z-score values to unify value scales between children and adults to make them comparable. RESULTS: HIV-Rec-children had higher T-cell receptor excision circles (TREC) and lower interleukin (IL)-7 levels than HIV-Rec-adults (p < 0.05). When we analyzed Z-score values, HIV-Rec-children had higher TREC Z-score levels (p = 0.03) than HIV-Rec-adults but similar IL-7 Z-score levels. Regarding T-cell subsets, HIV-Rec-children had higher naïve CD4(+ )(CD4(+)CD45RA (hi+)CD27(+)), naïve CD8(+ )(CD8(+)CD45RA (hi+)CD27(+)), and memory CD8(+ )(CD8(+)CD45RO(+)) cells/μl than HIV-Rec-adults, but similar memory CD4(+ )(CD4(+)CD45RO(+)) counts. HIV-Rec-children had lower naïve CD8(+ )Z-score values than HIV-Rec-adults (p = 0.05). CONCLUSION: Our data suggest that HIV-Rec-children had better thymic function than HIV-Rec-adults and this fact affects the peripheral T-cell subsets. Thus, T-cell recovery after HAART in HIV-Rec-adults could be the consequence of antigen-independent peripheral T-cell expansion while in HIV-Rec-children thymic output could play a predominant role in immune reconstitution

Linking In Vitro Models of Endothelial Dysfunction with Cell Senescence

Disfunció endotelial; Envellliment cel·lularDisfunción endotelial; Envejecimiento celularEndothelial dysfunction; SenescenceEndothelial cell dysfunction is the principal cause of several cardiovascular diseases that are increasing in prevalence, healthcare costs, and mortality. Developing a standardized, representative in vitro model of endothelial cell dysfunction is fundamental to a greater understanding of the pathophysiology, and to aiding the development of novel pharmacological therapies. We subjected human umbilical vein endothelial cells (HUVECs) to different periods of nutrient deprivation or increasing doses of H2O2 to represent starvation or elevated oxidative stress, respectively, to investigate changes in cellular function. Both in vitro cellular models of endothelial cell dysfunction-associated senescence developed in this study, starvation and oxidative stress, were validated by markers of cellular senescence (increase in β-galactosidase activity, and changes in senescence gene markers SIRT1 and P21) and endothelial dysfunction as denoted by reductions in angiogenic and migratory capabilities. HUVECs showed a significant H2O2 concentration-dependent reduction in cell viability (p < 0.0001), and a significant increase in oxidative stress (p < 0.0001). Furthermore, HUVECs subjected to 96 h of starvation, or exposed to concentrations of H2O2 of 400 to 1000 μM resulted in impaired angiogenic and migratory potentials. These models will enable improved physiological studies of endothelial cell dysfunction, and the rapid testing of cellular efficacy and toxicity of future novel therapeutic compounds.This research was funded by Beca de Investigacion Basica en Cardiologia from the Sociedad Española de Cardiologia, Fondo de Investigacion en Salud (grants PI18/00277, PI16/00742, PI19/00264, PI18/00960 and PI15/00553) from the Spanish Ministry of Science and Innovation, Instituto de Salud Carlos III–Fondo Europeo de Desarrollo Regional (FEDER), and Spanish Society of Respiratory Medicine (SEPAR) and Catalan Society of Pneumology (SOCAP) grants. FRJT and OTC are the recipients of the Ayudas para la formación de profesorado universitario (FPU19/04925) and Miguel Servet (CP17/00114) grants, respectively, from the Spanish Ministry of Science and Innovation. IDIBAPS belongs to the CERCA Programme, and receives partial funding from the Generalitat de Catalunya. Cofunding was provided by the Fondo Europeo de Desarrollo Regional (FEDER); “Una manera de hacer Europa”