Validation of geomagnetically induced current modelling code

A paper by Horton et al. (2012) details a test grid containing 8 substations with 15 transformers connected by 15 lines. The paper gives detailed information about location, resistances and connections including features such as capacitors, delta and composite transformer types. The model output for 1 V/km in the north-south and east-west directions are provided. In early 2017, the BGS Geomagnetism team produced an equivalent model using the Nodal Admittance Method and proved their model to be consistent with Horton et al. This report outlines our approach and results

Being a peer support mentor for individuals who have had a lower limb amputation:an interpretative phenomenological analysis

Purpose: Although peer support has received research attention within different health related contexts, there is limited research considering individuals who have experienced an amputation. In particular, the peer mentoring role is under-explored. Therefore, this research aimed to explore the experiences of participants delivering peer support interventions to individuals with lower limb loss. Methods: Eight people who acted as peer mentors for people with limb loss took part in semi-structured interviews. Data were analyzed using Interpretative Phenomenological Analysis (IPA). Results: Two overarching themes were identified from the data: “Developing a Helpful Self”, in which the personal value and meaning of being a peer mentor is presented, and “Connecting with Vulnerability”, which addresses the emotional challenges of peer mentoring and the impact of these on wellbeing. Conclusions: Findings suggest positive experiences of providing support, including increased hope, resilience and a sense of belonging and connection to others. However, peer mentors experienced challenges related to uncertainty and doubt about their mentoring abilities and with developing and maintaining resilience in the role. Recommendations include the development of training packages and increased clarity for volunteers of the peer mentor role.Implications for rehabilitation It is important to define clearly the role of a peer mentor and the responsibilities this involves. Peer mentors should be provided with support and training to increase their confidence and ability to act appropriately when encountering distress. It is important to provide transparent guidelines and procedures to support peer mentors to minimize concerns over risk and safety. Feedback regarding how effective the support offered is and how it could be improved should be provided

Sexual healthcare professionals’ views on HPV vaccination for men in the UK

Background: Human Papillomavirus (HPV) vaccination for men could prevent anal cancers amongst men who have sex with men (MSM). Methods: An e-survey of attitudes towards vaccination for men in the UK was conducted in July–August 2014. Results: Among 325 sexual health professionals, 14% were already vaccinating men against HPV, 83% recommended genderneutral HPV vaccination and 65% recommended targeting MSM. Over 50% reported having poor knowledge about the use of HPV vaccine for MSM and the skills to identify MSM likely to benefit from HPV vaccination. Conclusions: Clear advice and guidelines on HPV vaccine use for men at sexual health clinics are required to ensure equitable opportunities for vaccination

Differential Magnetometer Measurements of Geomagnetically Induced Currents in a Complex High Voltage Network

Space weather poses a hazard to grounded electrical infrastructure such as high voltage (HV) transformers, through the induction of geomagnetically induced currents (GICs). Modelling GIC requires knowledge of the source magnetic field and the Earth's electrical conductivity structure, in order to calculate the geoelectric fields generated during magnetic storms, as well as knowledge of the topology of the HV network. Direct measurement of GICs at the ground neutral in substations is possible with a Hall‐effect probe, but such data are not widely available. To validate our HV network model, we use the Differential Magnetometer Method (DMM) to measure GICs in the 400 kV grid of Great Britain. We present DMM measurements for the 26 August 2018 storm at a site in eastern Scotland with up to 20 A recorded. The line GIC correlate well with Hall probe measurements at a local transformer, though they differ in amplitude by an order of magnitude (a maximum of ~2 A). We deployed a long‐period magnetotelluric (MT) instrument to derive the local impedance tensor which can be used to predict the geoelectric field from the recorded magnetic field. Using the MT‐derived electric field estimates, we model GICs within the network, accounting for the difference in magnitude between the DMM‐measured line currents and earth currents at the local substation. We find the measured line and earth GICs match the expected GICs from our network model, confirming that detailed knowledge of the complex network topology and its resistance parameters is essential for accurately computing GICs

An Absolute Measurement of Neutron Flux Using Calorimetry

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Confinement, DCSB, Bound States, and the Quark-Gluon Vertex

Aspects of the dressed-quark-gluon vertex and their role in the gap and Bethe-Salpeter equations are briefly surveyed using an intuitive model. The model allows one to elucidate why a linear extrapolation to the chiral limit of extant lattice data on the dressed-quark mass-function overestimates this function and hence the value of the vacuum quark condensate. The diagrammatic content of the vertex described is explicitly enumerable. This property is essential to the symmetry preserving study of bound state properties. It facilitates a realistic analysis of vector and pseudoscalar meson masses, and also allows the accuracy of standard truncations to be gauged. The splitting between vector and pseudoscalar meson masses is observed to vanish as the current-quark mass increases. That argues for the mass of the pseudoscalar partner of the Upsilon(1S) to be above 9.4GeV. Moreover, in this limit the rainbow-ladder truncation provides an increasingly accurate estimate of a bound state's mass.Comment: 6 pages, Contribution to the Proceedings of "QCD Down Under", Special Centre for the Subatomic Structure of Matter, University of Adelaide, 10-19/March/200

Differential magnetometer measurements in the UK high-voltage power grid

Extreme space weather events can pose risks to ground based infrastructure like high voltage (HV) transformers, railways and gas pipelines through the induction of geomagnetically induced currents(GICs). Modelling GICs requires knowledge about the source magnetic field and the electrical conductivity structure of the Earth. We use the Differential Magnetometer Method (DMM) to indirectly measure GIC in HV lines rather than GIC through ground points

Geomagnetically induced current model validation from New Zealand's South Island

Geomagnetically induced currents (GICs) during a space weather event have previously caused transformer damage in New Zealand. During the 2015 St. Patrick's Day Storm, Transpower NZ Ltd has reliable GIC measurements at 23 different transformers across New Zealand's South Island. These observed GICs show large variability, spatially and within a substation. We compare these GICs with those calculated from a modeled geolectric field using a network model of the transmission network with industry‐provided line, earthing, and transformer resistances. We calculate the modeled geoelectric field from the spectra of magnetic field variations interpolated from measurements during this storm and ground conductance using a thin‐sheet model. Modeled and observed GIC spectra are similar, and coherence exceeds the 95% confidence threshold, for most valid frequencies at 18 of the 23 transformers. Sensitivity analysis shows that modeled GICs are most sensitive to variation in magnetic field input, followed by the variation in land conductivity. The assumption that transmission lines follow straight lines or getting the network resistances exactly right is less significant. Comparing modeled and measured GIC time series highlights that this modeling approach is useful for reconstructing the timing, duration, and relative magnitude of GIC peaks during sudden commencement and substorms. However, the model significantly underestimates the magnitude of these peaks, even for a transformer with good spectral match. This is because of the limited range of frequencies for which the thin‐sheet model is valid and severely limits the usefulness of this modeling approach for accurate prediction of peak GICs

Potential Predictors of Injury Among Pre-Professional Ballet and Contemporary Dancers

Injuries occur frequently among ballet and contemporary dancers. However, limited literature exists on injuries to pre-professional dancers in the USA. The goals of this study were to 1. provide a descriptive epidemiology of the incidence of musculoskeletal injuries in an adolescent and young adult dance population and 2. identify parsimonious regression models that could be potentially used to predict injury incidence. The study was based at the University of North Carolina School of the Arts (UNCSA) from Fall 2009 to Spring 2015. An injury was defined as any event that caused a dancer to be seen at the UNCSA Student Health Services and caused the dancer to modify or curtail dance activity for at least 1 day. Injury rate ratios (IRRs) were calculated using negative binomial generalized estimating equations. Models predicting injury rates were built using forward selection, stratified by sex. Among 480 dancers, 1,014 injuries were sustained. Most injuries were to the lower extremity and the result of overuse. There were differences in upper extremity, lower extremity, and traumatic injury rates by demographic subgroups. Among females, the most parsimonious predictive model for injury rates included a self-reported history of depression, age at time of injury, and number of injuries sustained at UNCSA prior to the semester of current injury. Among males, the most parsimonious model was a univariate model with family history of alcohol or drug problems. Strategies for traumatic injury prevention among dancers should be both sex- and style-specific. No differences were observed in overuse injury rates by sex or style, suggesting that generic overuse prevention strategies may not need to be guided by these factors. It is concluded that strategies can be implemented to reduce and mitigate the consequences of injuries if not the injuries themselves

14 years of photometric monitoring of MM Dra and a suspected variable in the field of blazar 1ES 1959+650

We present a 14 year photometric study of one confirmed and one suspected variable star in the field of the TeV blazar 1ES 1959+650. Both stars have previously been used as comparison stars for the blazar 1ES 1959+650, and are identified as star 3 and star 5 by Villata et. al. (1998). Star 5 is also known as MM Dra and is an eclipsing binary of the EW UMa type, exhibiting evidence of the O'Connell effect. A very recent calibration based on Gaia parallaxes suggests a distance of about 600 pc. Star 3 is a variable star of undetermined type and a color analysis suggests it is a late K or early M type star