Fermi Surface Nesting and the Origin of the Charge Density Wave in NbSe2_2

We use highly accurate density functional calculations to study the band structure and Fermi surfaces of NbSe2. We calculate the real part of the non-interacting susceptibility, Re chi_0(q), which is the relevant quantity for a charge density wave (CDW) instability and the imaginary part, Im chi_0(q), which directly shows Fermi surface (FS) nesting. We show that there are very weak peaks in Re chi_0(q) near the CDW wave vector, but that no such peaks are visible in Im chi_0(q), definitively eliminating FS nesting as a factor in CDW formation. Because the peak in Re chi_0(q) is broad and shallow, it is unlikely to be the direct cause of the CDW instability. We briefly address the possibility that electron-electron interactions (local field effects) produce additional structure in the total (renormalized) susceptibility, and we discuss the role of electron-ion matrix elements.Comment: Replacement of Table II values, minor changes to tex

Mesoscale observations of Joule heating near an auroral arc and ion-neutral collision frequency in the polar cap E region

We report on the first mesoscale combined ionospheric and thermospheric observations, partly in the vicinity of an auroral arc, from Svalbard in the polar cap on 2 February 2010. The EISCAT Svalbard radar employed a novel scanning mode in order to obtain F and E region ion flows over an annular region centered on the radar. Simultaneously, a colocated Scanning Doppler Imager observed the E region neutral winds and temperatures around 110 km altitude using the 557.7 nm auroral optical emission. Combining the ion and neutral data permits the E region Joule heating to be estimated with an azimuthal spatial resolution of ∼64 km at a radius of ∼163 km from the radar. The spatial distribution of Joule heating shows significant mesoscale variation. The ion-neutral collision frequency is measured in the E region by combining all the data over the entire field of view with only weak aurora present. The estimated ion-neutral collision frequency at ∼113 km altitude is in good agreement with the MSIS atmospheric model

Three-dimensional coherent X-ray diffraction imaging of a ceramic nanofoam: determination of structural deformation mechanisms

Ultra-low density polymers, metals, and ceramic nanofoams are valued for their high strength-to-weight ratio, high surface area and insulating properties ascribed to their structural geometry. We obtain the labrynthine internal structure of a tantalum oxide nanofoam by X-ray diffractive imaging. Finite element analysis from the structure reveals mechanical properties consistent with bulk samples and with a diffusion limited cluster aggregation model, while excess mass on the nodes discounts the dangling fragments hypothesis of percolation theory.Comment: 8 pages, 5 figures, 30 reference

Progress in Three-Dimensional Coherent X-Ray Diffraction Imaging

The Fourier inversion of phased coherent diffraction patterns offers images without the resolution and depth-of-focus limitations of lens-based tomographic systems. We report on our recent experimental images inverted using recent developments in phase retrieval algorithms, and summarize efforts that led to these accomplishments. These include ab-initio reconstruction of a two-dimensional test pattern, infinite depth of focus image of a thick object, and its high-resolution (~10 nm resolution) three-dimensional image. Developments on the structural imaging of low density aerogel samples are discussed.Comment: 5 pages, X-Ray Microscopy 2005, Himeji, Japa

Redemptive failure in contemporary American sports literature

This thesis explores America’s fascination with its own sports as purveyors of national identity. American literature has found unique inspiration in sporting competition, not only depicting professional athletes, but drawing from the experiences of fans and amateurs. While the athlete’s heroism and eventual fall has been analysed in previous discussions of this topic, my route of inquiry positions decline and defeat as more central and complex concepts. The focus of this thesis is on the remarkably diverse ways in which contemporary writers reimagine aspects of sporting failure both for their characters and within their own creative process. The centrality of failure seems an affront to the United States’ celebration of success and victory. However, the common strand in the most ambitious contemporary sports writing is to portray experiences of loss and failure as paradoxical routes to self-affirmation. Postmodern writing on sports has taken from the drama and narrative implicit in sporting contest, but uses this framework to question ideas of masculinity, ethnicity, memory and myth. The writers I discuss incorporate failure into these themes to arrive at points of redemptive discovery

Federating distributed clinical data for the prediction of adverse hypotensive events

The ability to predict adverse hypotensive events, where a patient's arterial blood pressure drops to abnormally low (and dangerous) levels, would be of major benefit to the fields of primary and secondary health care, and especially to the traumatic brain injury domain. A wealth of data exist in health care systems providing information on the major health indicators of patients in hospitals (blood pressure, temperature, heart rate, etc.). It is believed that if enough of these data could be drawn together and analysed in a systematic way, then a system could be built that will trigger an alarm predicting the onset of a hypotensive event over a useful time scale, e.g. half an hour in advance. In such circumstances, avoidance measures can be taken to prevent such events arising. This is the basis for the Avert-IT project (http://www.avert-it.org), a collaborative EU-funded project involving the construction of a hypotension alarm system exploiting Bayesian neural networks using techniques of data federation to bring together the relevant information for study and system development

BODIPY-based conjugated polymers for broadband light sensing and harvesting applications

The synthesis of novel low band-gap polymers has significantly improved light sensing and harvesting in polymer-fullerene devices. Here the synthesis of two low band-gap polymers based on the 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene core (BODIPY), and either bis(3,4-ethylenedioxythiophene) (bis-EDOT) or its all-sulfur analogue bis(3,4-ethylenedithiathiophene) (bis-EDTT) are described. The polymers demonstrate ambipolar charge transport and are shown to be suitable for broadband light sensing and solar energy harvesting in solution-processable polymer-fullerene devices

The forgotten age group: The need for targeted physical activity and healthy lifestyle promotion for older adolescents

Introduction Globally, limited research has examined healthy lifestyle promotion for older adolescents (16–18 years), yet habitual healthy lifestyles can be developed at this time. Most initiatives have been aimed at adults or younger children and research has highlighted England to be up to ten tears behind other countries in prioritising health education (Berkman et al., 2010). This research aims to examine older adolescents’ knowledge and understanding of healthy lifestyle [nutrition and physical activity (PA)] recommendations and compare these to their self-reported PA, active transportation, active leisure and food intake. It will also ask their experiences of how healthy lifestyles are promoted to them. Method Ninety-three participants (39M; 54F) (M age=16.9, SD=.40 years), from 3 low socio-economic English high schools completed an online questionnaire on their self-reported: (1) daily physical activity (PA); (2) active transportation (AT); (3) active leisure time (AL); (4) food intake; (5) experiences of healthy lifestyles promotion; and (6) perceived healthiness. Questions were merged from both the validated Global Physical Activity Questionnaire (GPAQ) (WHO, 2004) and the Short Form Food Frequency Questionnaire (SFFFQ) (Cleghorn & Cade, 2017). To examine perceived healthiness, participants rated their overall health on a 5-point scale over the past 12 months. Daily PA, active transport, active leisure and how participants felt healthy lifestyles were promoted to them, were asked via open-ended questions. The SFFFQ was used to generate a food group score [via the Diet and Nutrition Tool for Evaluation (Cleghorn & Cade, 2017)], which were then added together to create an overall diet quality score (DQS). Data analysis was undertaken within SPSS 24.0 (IBM Corp, Armok, NY, USA). A multi-variance of statistical analysis (MANOVA) assessed group differences across multiple dependent variables of the food group scores and overall DQS. GPAQ questions were analysed individually according to demographics: sex, and perceived healthiness. Univariate analysis of variance (ANOVA) was then undertaken for each question to assess the group differences per element of PA. Thematic analysis was used to analyse all open-ended questions. Statistical significance was set at <.05. Results Only 60% reached PA recommended guidelines. Yet, 92% (n=86) used active travel for a least 10 mins continuously; of these, 86% (n=80) undertook this at least 5 days per week. Over half (51%, n=47) undertook MVPA as active leisure. However, 66% (n=61) spent ≥5 hours sedentary and only 17% (n=16) met recommended nutritional guidelines for health. Males who rated themselves as having poor health had eaten the recommended intakes of fat (1.00±.00), compared to females who rated themselves as having poor health but ate more than the recommended intakes of fat (2.60±.89). Nearly all participants (90%, n=80) did not report school as a place that promoted healthy lifestyles. Discussion As a public health measure and an educational policy matter, it is recommended schools implement more targeted PA and healthy eating initiatives for older adolescents. Further research is also needed to examine male older adolescents’ health literacy to get a deeper insight into their understanding and application of information relating to their health. References Berkman, N. D., Davis, T. C., & McCormack, L. (2010). Health literacy: what is it? Journal of Health Communication, 15(S2), 9-19. Cleghorn, C., & Cade, J. (2017). Short Form Food Frequency Questionnaire. Available online: https://www.nutritools.org/tools/ World Health Organization (2004). Global Physical Activity Questionnaire (GPAQ). World Health Organization. Geneva, Switzerland

ADAPT model: Positioning inclusion at the heart of physical education, sport and physical activity

The purpose of this article is to offer professional developmentby challenging current pedagogical strategies and suggesting an innovative way to re-examine how we can support children within all aspects of school sport and beyond. As the founder and director of Inclusive Sport, Tom has developed a new model that places inclusion at the heart of PE, sport and physical activity. What is offered in this article is not only the model itself but ways in which your own teaching and coaching could be supported by this model to enable lifelong and lifewide participation. This ADAPT model reconceptualises the traditional STEP or STTEP model and uses considerations and prompt questions for those who are teaching and planning and offers justification for each aspect of the model (see Figure 1). There are five areas to consider when planning: Activity, Differentiation, Area, Personalities and Tools. Each of these will be unpacked and ideas shared as to what should be considered within each aspect

'Drive to drink!'

This paper will examine children’s understanding of when to drink. The Natural Hydration Council (2017) proposed that children do not always recognise the early stages of thirst and this can mean that they are vulnerable to becoming dehydrated. Kenney and Chiu (2001) earlier found that children rarely exhibit voluntary dehydration for activities lasting 45 minutes or less. Therefore, it could be proposed that children will not often exhibit the ‘drive to drink’ or express themselves as wanting a drink after physical education lessons, as most physical education lessons in England and Ireland last approximately 40-45 minutes. Previous research has considered what children are drinking at mealtimes, (UK National Diet and Nutrition Survey) and focused on the water consumption of children during secondary aged children. A study in France (Bonnet et al. 2012) suggested that more than two-thirds of children aged 9-11 years were not drinking enough. This paper focuses on young children, and their understanding of when to drink in relationship to physical activity and physical education classes. It is hypothesised in this paper that children do not understand when to drink to remain hydrated, before, within and after physical education classes. This paper will examine the children’s understanding and make comparisons to how much children should drink according to the total amount of fluids recommended for the different ages according to the European Food Safety Authority (EFSA). The results will also make comparisons between ages, gender and location of the children and analyse if there are similarities or differences between the two countries. The paper will offer innovative perspectives on children’s understanding of when they are driven to drink or not and help practitioners and teachers to support the children’s physical activity, health and wellbeing allowing them to stay hydrated within, before and after physical education and physical activity