687 research outputs found

    Lunar radiation environment and space weathering from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER)

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    [1] The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) measures linear energy transfer by Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs) on the Lunar Reconnaissance Orbiter (LRO) Mission in a circular, polar lunar orbit. GCR fluxes remain at the highest levels ever observed during the space age. One of the largest SEP events observed by CRaTER during the LRO mission occurred on June 7, 2011. We compare model predictions by the Earth-Moon-Mars Radiation Environment Module (EMMREM) for both dose rates from GCRs and SEPs during this event with results from CRaTER. We find agreement between these models and the CRaTER dose rates, which together demonstrate the accuracy of EMMREM, and its suitability for a real-time space weather system. We utilize CRaTER to test forecasts made by the Relativistic Electron Alert System for Exploration (REleASE), which successfully predicts the June 7th event. At the maximum CRaTER-observed GCR dose rate (∼11.7 cGy/yr where Gy is a unit indicating energy deposition per unit mass, 1 Gy = 1 J/kg), GCRs deposit ∼88 eV/molecule in water over 4 billion years, causing significant change in molecular composition and physical structure (e.g., density, color, crystallinity) of water ice, loss of molecular hydrogen, and production of more complex molecules linking carbon and other elements in the irradiated ice. This shows that space weathering by GCRs may be extremely important for chemical evolution of ice on the Moon. Thus, we show comprehensive observations from the CRaTER instrument on the Lunar Reconnaissance Orbiter that characterizes the radiation environment and space weathering on the Moon

    Characteristics of a person-centred coaching approach

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    Within this paper we propose a need to better understand what is meant by a person-centred approach to coaching and in particular, to consider the intention that drives coach behaviours. Much of the extant coaching literature focuses on pedagogical models and theories of learning; without detracting from this important body of work, we suggest that a holistic approach requires a greater focus on coaches' inter- and intra- personal knowledge. In this paper, video stimulated recall was used to guide interviews with Alpine ski coaches, to explore their thought processes and intentions behind person-centred delivery. The findings suggest these coaches adopted other-centred intentions that are facilitated by an accurate self-assessment, a big picture perspective and a willingness to learn. Consequently, the concept of humility is proposed as a guiding principle for person-centred coaching, and a conceptual model (POWA) is presented as a solution to the challenges we identify throughout the paper

    FAR out? An examination of converging, diverging and intersecting smart grid futures in the United Kingdom

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    We describe a novel application of the field anomaly relaxation (FAR) method of scenario construction to the complex problem of smart grid development. We augment the FAR methodology with extensive expert input through all four steps to incorporate detailed knowledge of the technical, economic and policy issues relevant to informing scenarios for smart grid development in the United Kingdom. These steps inform scenarios useful to policymakers, regulators and the energy industry. We found this extended method to be flexible and reliable. Analysis of smart grid development yielded seven dimensions, allowing for portrayal of a complex and informed set of scenarios. The expert input and feedback identified branching points allowing switching between scenarios – a powerful dynamic feature to assist policy development for a fast-changing technological and regulatory landscape

    Patient Polypharmacy use Following a Multi-Disciplinary Dementia Care Program in a Memory Clinic: A Retrospective Cohort Study

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    Introduction. Dementia increases the risk of polypharmacy. Timely detection and optimal care can optimize the prognosis for patients with dementia, which may in turn reduce polypharmacy. We aimed to compare the change in polypharmacy use among memory clinic patients living with dementia who participate in a dementia care program, vs those who did not. We hypothesized that patients in the dementia care program would reduce their use of polypharmacy compared to those who were not in the program. Methods. We retrospectively analyzed EMR data from a university memory clinic. The final analytic sample consisted of 381 patients: 107 in the program and 274 matched patients not in the program. We used logistic regression of outcomes (five or more concurrent medications) at follow-up, controlled for the same outcome at baseline to assess the change in polypharmacy, and stratified outcomes by prescription and over-the-counter. Results. The two groups did not differ in the use of five or more total and prescription medications at follow-up controlling for the use of 5 or more of the respective medications at baseline and covariates. Being in the program was associated with a threefold lower odds of using 5 or more over-the-counter medications at follow-up (OR=0.30; p<0.001) after controlling for using 5 or more over-the-counter medications at baseline and covariates. Conclusions. Dementia care might reduce polypharmacy of over-the-counter medications, potentially reducing risky medication-medication interactions. More research is needed to infer causality and understand how to reduce prescription medication polypharmacy

    A revised biosynthetic pathway for the cofactor F-420 in prokaryotes

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    Cofactor F420 plays critical roles in primary and secondary metabolism in a range of bacteria and archaea as a low-potential hydride transfer agent. It mediates a variety of important redox transformations involved in bacterial persistence, antibiotic biosynthesis, pro-drug activation and methanogenesis. However, the biosynthetic pathway for F420 has not been fully elucidated: neither the enzyme that generates the putative intermediate 2-phospho-L-lactate, nor the function of the FMN-binding C-terminal domain of the γ-glutamyl ligase (FbiB) in bacteria are known. Here we present the structure of the guanylyltransferase FbiD and show that, along with its archaeal homolog CofC, it accepts phosphoenolpyruvate, rather than 2-phospho-L-lactate, as the substrate, leading to the formation of the previously uncharacterized intermediate dehydro-F420-0. The C-terminal domain of FbiB then utilizes FMNH2 to reduce dehydro-F420-0, which produces mature F420 species when combined with the γ-glutamyl ligase activity of the N-terminal domain. These new insights have allowed the heterologous production of F420 from a recombinant F420 biosynthetic pathway in Escherichia coli

    Whole system radar modelling::Simulation and validation

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    The ever-expanding horizon of radar applications demands solutions with high-end radar functionalities and technologies and is often limited by the available radar equipment, cost and time. A practical method to tackle the situation is to rely on the modelling and simulation of radar systems based on the user requirements. The comprehensive system-level modelling of a pulsed Doppler radar in MATLAB/Simulink consisting of all the fundamental blocks in the transmit chain, the environment, the receive chain, and the data processing chain is presented in this article. The first half of the article discusses the high-fidelity simulation of each building block in the radar model. In the second half of the article, the range-Doppler plot generated from the high-fidelity radar model is compared and validated using the range-Doppler plot from a real radar trial. The radar phase noise plays a crucial role in the detection of slowly moving, low radar cross-section targets in the presence of strong clutter. The article also briefly discusses the effects of radar oscillator phase noise in the range-Doppler plot. The validated, fully flexible radar model has the advantage of supporting the addition of further building blocks and optimising the parameters based on user requirements

    Structure-based design and synthesis of antiparasitic pyrrolopyrimidines targeting pteridine reductase 1

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    The treatment of Human African Trypanosomiasis remains a major unmet health need in sub-Saharan Africa. Approaches involving new molecular targets are important and pteridine reductase 1 (PTR1), an enzyme that reduces dihydrobiopterin in Trypanosoma spp. has been identified as a candidate target and it has been shown previously that substituted pyrrolo[2,3-d]pyrimidines are inhibitors of PTR1 from T. brucei (J. Med. Chem. 2010, 53, 221-229). In this study, 61 new pyrrolo[2,3-d]pyrimidines have been prepared, designed with input from new crystal structures of 23 of these compounds complexed with PTR1, and evaluated in screens for enzyme inhibitory activity against PTR1 and in vitro antitrypanosomal activity. 8 compounds were sufficiently active in both screens to take forward to in vivo evaluation. Thus although evidence for trypanocidal activity in a stage I disease model in mice was obtained, the compounds were too toxic to mice for further development

    Decline of a rare moth at its last known English site : causes and lessons for conservation

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    The conditions required by rare species are often only approximately known. Monitoring such species over time can help refine management of their protected areas. We report population trends of a rare moth, the Dark Bordered Beauty Epione vespertaria (Linnaeus, 1767) (Lepidoptera: Geometridae) at its last known English site on a protected lowland heath, and those of its host-plant, Salix repens (L.) (Malpighiales: Salicaceae). Between 2007 and 2014, adult moth density reduced by an average of 30-35% annually over the monitored area, and its range over the monitored area contracted in concert. By comparing data from before this decline (2005) with data taken in 2013, we show that the density of host-plants over the monitored area reduced three-fold overall, and ten-fold in the areas of highest host-plant density. In addition, plants were significantly smaller in 2013. In 2005, moth larvae tended to be found on plants that were significantly larger than average at the time. By 2013, far fewer plants were of an equivalent size. This suggests that the rapid decline of the moth population coincides with, and is likely driven by, changes in the hostplant population. Why the host-plant population has changed remains less certain, but fire, frost damage and grazing damage have probably contributed. It is likely that a reduction in grazing pressure in parts of the site would aid host-plant recovery, although grazing remains an important site management activity. Our work confirms the value of constant monitoring of rare or priority insect species, of the risks posed to species with few populations even when their populations are large, of the potential conflict between bespoke management for species and generic management of habitats, and hence the value of refining our knowledge of rare species' requirements so that their needs can be incorporated into the management of protected areas
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