6,297 research outputs found

    Directly comparing coronal and solar wind elemental fractionation

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    Context. As the solar wind propagates through the heliosphere, dynamical processes irreversibly erase the signatures of the near-Sun heating and acceleration processes. The elemental fractionation of the solar wind should not change during transit, however, making it an ideal tracer of these processes. Aims. We aim to verify directly if the solar wind elemental fractionation is reflective of the coronal source region fractionation, both within and across different solar wind source regions. Methods. A backmapping scheme was used to predict where solar wind measured by the Advanced Composition Explorer (ACE) originated in the corona. The coronal composition measured by the Hinode Extreme ultraviolet Imaging Spectrometer (EIS) at the source regions was then compared with the in situ solar wind composition. Results. On hourly timescales, there is no apparent correlation between coronal and solar wind composition. In contrast, the distribution of fractionation values within individual source regions is similar in both the corona and solar wind, but distributions between different sources have a significant overlap. Conclusions. The matching distributions directly verify that elemental composition is conserved as the plasma travels from the corona to the solar wind, further validating it as a tracer of heating and acceleration processes. The overlap of fractionation values between sources means it is not possible to identify solar wind source regions solely by comparing solar wind and coronal composition measurements, but a comparison can be used to verify consistency with predicted spacecraft-corona connections

    Lifting the veil of depression and alcoholism in sport coaching: how do we care for carers?

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    The purpose of this article is to explore the insights of an elite sport coach living with comorbid depression and alcohol misuse. Such consideration is necessary because as coaching is increasingly repositioned as a caring activity the wellbeing of coaches themselves has rarely been considered. To address this gap, a narrative analysis methodology and a story telling approach was used to present the experiences of a case study coach (Steve). The story is derived from Steveā€™s own perspective and the perspective of his wife, Jane. This novel multi-voiced approach reveals the complex interplay between the sporting environment, Steveā€™s depression and his alcohol related problems. In doing so, Steveā€™s story makes an original contribution by unveiling the issue of mental health in elite sport coaching. Steveā€™s story depicts the significant impact of depressive symptoms, coupled by excessive alcohol use on a coach, their personal life, and their career. Using the work of Goffman and Sartre, the story alludes to how such symptoms can be hidden, to greater and lesser extents, from professional colleagues. This is an important theoretical contribution, because to care for coaches, colleagues, employers, and health professionals will need to understand the needs of individuals such as Steve. Developing an open and supportive culture, which accepts that coaches are fallible, may however be a challenge within professional sport contexts

    Active Region Modulation of Coronal Hole Solar Wind

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    Active regions (ARs) are a candidate source of the slow solar wind (SW), the origins of which are a topic of ongoing research. We present a case study that examines the processes by which SW is modulated in the presence of an AR in the vicinity of the SW source. We compare properties of SW associated with a coronal hole (CH)ā€“quiet Sun boundary to SW associated with the same CH but one Carrington rotation later, when this region bordered the newly emerged NOAA AR 12532. Differences found in a range of in situ parameters are compared between these rotations in the context of source region mapping and remote sensing observations. Marked changes exist in the structure and composition of the SW, which we attribute to the influence of the AR on SW production from the CH boundary. These unique observations suggest that the features that emerge in the AR-associated wind are consistent with an increased occurrence of interchange reconnection during SW production, compared with the initial quiet Sun case

    Computational study of the enhancement of graphene electrodes for use in Li-ion batteries via forming superlattices with transition metal dichalcogenides

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    This is the final version. Available on open access from the American Chemical Society via the DOI in this record.ā€ÆIn our study, we examined nine transition metal dichalcogenide (TMDC)-graphene superlattices as potential Li-ion intercalation electrodes. We determined their voltages, with ScS2-graphene in T- and R-phases showing the highest at around 3 V, while the others ranged from 0 to 1.5 V. Most superlattices exhibited minimal volumetric expansion (5 to 10%), similar to NMC (8%), except for SnS2-T and NiS2-T, which expanded up to nearly 20%. We evaluated their capacities using a stability metric, EIS, and found that ScS2-T, ScS2-R, and TiS2-T could be intercalated up to two Li ions per MX2 unit without decomposing to Li2S, yielding capacities of 306.77 mA h/g for both ScS2 phases and 310.84 mA h/g for TiS2-T, roughly equivalent to LiC2. MoS2-T could accept Li up to a limit of a = 15/16 in LiaMoS2Cb, corresponding to a capacity of 121.29 mA h/g (equivalent to LiC4). Examining the influence of graphene layers on MoS2-T, we observed a voltage decrease and an initial EIS decrease before effectively flat lining, which is due to charge donation to the middle graphene layer, reducing the electron concentration near the TMDC layer. As graphene layers increased, overall volume expansion decreased with Li intercalation, which is attributed to the in-plane expansion changing. Our results underscore the potential of TMDC-graphene superlattices as Li-ion intercalation electrodes, offering low volumetric expansions, high capacities, and a wide voltage range. These superlattices all show an increase in the capacity of the graphene.Engineering and Physical Sciences Research Council (EPSRC

    Properties of layered TMDC superlattices for electrodes in Li-ion and Mg-ion batteries

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    This is the final version. Available on open access from the American Chemical Society via the DOI in this record.ā€ÆIn this work, we present a first-principles investigation of the properties of superlattices made from transition metal dichalcogenides for use as electrodes in lithium-ion and magnesium-ion batteries. From a study of 50 pairings, we show that, in general, the volumetric expansion, intercalation voltages, and thermodynamic stability of vdW superlattice structures can be well approximated with the average value of the equivalent property for the component layers. We also found that the band gap can be reduced, improving the conductivity. Thus, we conclude that superlattice construction can be used to improve material properties through the tuning of intercalation voltages toward specific values and by increasing the stability of conversion-susceptible materials. For example, we demonstrate how pairing SnS2 with systems such as MoS2 can change it from a conversion to an intercalation material, thus opening it up for use in intercalation electrodes.Engineering and Physical Sciences Research Council (EPSRC

    Histological 3D reconstruction and in vivo lineage tracing of the human endometrium

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    Regular menstrual shedding and repair of the endometrial functionalis is unique to humans and higherā€order primates. The current consensus postulates endometrial glands to have a singleā€tubular architecture, where multiā€potential stem cells reside in the blindā€ending glandularā€bases. Utilising fixed samples from patients, we have studied the threeā€dimensional (3D) microā€architecture of the human endometrium. We demonstrate that some nonā€branching, single, vertical functionalis glands originate from a complex horizontally interconnecting network of basalis glands. The existence of a multipotent endometrial epithelial stem cell capable of regenerating the entire complement of glandular lineages was demonstrated by in vivo lineage tracing, using naturally occurring somatic mitochondrial DNA mutations as clonal markers. Vertical tracking of mutated clones showed that at least one stemā€cell population resides in the basalis glands. These novel findings provide insight into the efficient and scarā€less regenerative potential of the human endometrium

    Histological 3D reconstruction and in vivo lineage tracing of the human endometrium

    Get PDF
    Regular menstrual shedding and repair of the endometrial functionalis is unique to humans and higherā€order primates. The current consensus postulates endometrial glands to have a singleā€tubular architecture, where multiā€potential stem cells reside in the blindā€ending glandularā€bases. Utilising fixed samples from patients, we have studied the threeā€dimensional (3D) microā€architecture of the human endometrium. We demonstrate that some nonā€branching, single, vertical functionalis glands originate from a complex horizontally interconnecting network of basalis glands. The existence of a multipotent endometrial epithelial stem cell capable of regenerating the entire complement of glandular lineages was demonstrated by in vivo lineage tracing, using naturally occurring somatic mitochondrial DNA mutations as clonal markers. Vertical tracking of mutated clones showed that at least one stemā€cell population resides in the basalis glands. These novel findings provide insight into the efficient and scarā€less regenerative potential of the human endometrium

    Relevance of Interleukin-6 and D-Dimer for Serious Non-AIDS Morbidity and Death among HIV-Positive Adults on Suppressive Antiretroviral Therapy

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    Background: Despite effective antiretroviral treatment (ART), HIV-positive individuals are at increased risk of serious non-AIDS conditions (cardiovascular, liver and renal disease, and cancers), perhaps due in part to ongoing inflammation and/or coagulation. To estimate the potential risk reduction in serious non-AIDS conditions or death from any cause that might be achieved with treatments that reduce inflammation and/or coagulation, we examined associations of interleukin-6 (IL-6), D-dimer, and high-sensitivity C-reactive protein (hsCRP) levels with serious non-AIDS conditions or death in 3 large cohorts. Methods: In HIV-positive adults on suppressive ART, associations of IL-6, D-dimer, and hsCRP levels at study entry with serious non-AIDS conditions or death were studied using Cox regression. Hazard ratios (HR) adjusted for age, gender, study, and regression dilution bias (due to within-person biomarker variability) were used to predict risk reductions in serious non-AIDS conditions or death associated with lower ā€œusualā€ levels of IL-6 and D-dimer. Results: Over 4.9 years of mean follow-up, 260 of the 3766 participants experienced serious non-AIDS conditions or death. IL-6, D-dimer and hsCRP were each individually associated with risk of serious non-AIDS conditions or death, HR = 1.45 (95% CI: 1.30 to 1.63), 1.28 (95% CI: 1.14 to 1.44), and 1.17 (95% CI: 1.09 to 1.26) per 2x higher biomarker levels, respectively. In joint models, IL-6 and D-dimer were independently associated with serious non-AIDS conditions or death, with consistent results across the 3 cohorts and across serious non-AIDS event types. The association of IL-6 and D-dimer with serious non-AIDS conditions or death was graded and persisted throughout follow-up. For 25% lower ā€œusualā€ IL-6 and D-dimer levels, the joint biomarker model estimates a 37% reduction (95% CI: 28 to 46%) in the risk of serious non-AIDS conditions or death if the relationship is causal. Conclusions: Both IL-6 and D-dimer are independently associated with serious non-AIDS conditions or death among HIV-positive adults with suppressed virus. This suggests that treatments that reduce IL-6 and D-dimer levels might substantially decrease morbidity and mortality in patients on suppressive ART. Clinical trials are needed to test this hypothesis

    A Full Pharmacological Analysis of the Three Turkey Ī²-Adrenoceptors and Comparison with the Human Ī²-Adrenoceptors

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    There are three turkey Ī²-adrenoceptors: the original turkey Ī²-adrenoceptor from erythrocytes (tĪ²trunc, for which the X-ray crystal structure has recently been determined), tĪ²3C and tĪ²4C-receptors. This study examined the similarities and differences between these avian receptors and mammalian receptors with regards to binding characteristics and functional high and low affinity agonist conformations.Stable cell lines were constructed with each of the turkey Ī²-adrenoceptors and 3H-CGP12177 whole cell binding, CRE-SPAP production and (3)H-cAMP accumulation assays performed. It was confirmed that the three turkey Ī²-adrenoceptors are distinct from each other in terms of amino acid sequence and binding characteristics. The greatest similarity of any of the turkey Ī²-adrenoceptors to human Ī²-adrenoceptors is between the turkey Ī²3C-receptor and the human Ī²2-adrenoceptor. There are pharmacologically distinct differences between the binding of ligands for the tĪ²trunc and tĪ²4C and the human Ī²-adrenoceptors (e.g. with CGP20712A and ICI118551). The tĪ²trunc and tĪ²4C-adrenoceptors appear to exist in at least two different agonist conformations in a similar manner to that seen at both the human and rat Ī²1-adrenoceptor and human Ī²3-adrenoceptors. The tĪ²3C-receptor, similar to the human Ī²2-adrenoceptor, does not, at least so far, appear to exist in more than one agonist conformation.There are several similarities, but also several important differences, between the recently crystallised turkey Ī²-adrenoceptor and the human Ī²-adrenoceptors. These findings are important for those the field of drug discovery using the recently structural information from crystallised receptors to aid drug design. Furthermore, comparison of the amino-acid sequence for the turkey and human adrenoceptors may therefore shed more light on the residues involved in the existence of the secondary Ī²-adrenoceptor conformation
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