144 research outputs found
Signatures of the non-Maxwellian -distributions in optically thin line spectra. II. Synthetic Fe XVII--XVIII X-ray coronal spectra and predictions for the Marshall Grazing-Incidence X-ray Spectrometer (MaGIXS)
We investigated the possibility of diagnosing the degree of departure from
the Maxwellian distribution using the Fe XVII - Fe XVIII spectra originating in
plasmas in collisional ionization equilibrium, such as in the cores of solar
active regions or microflares. The original collision strengths for excitation
are integrated over the non-Maxwellian electron -distributions
characterized by a high-energy tail. Synthetic X-ray emission line spectra were
calculated for a range of temperatures and . We focus on the 6-24 A
spectral range to be observed by the upcoming Marshall Grazing-Incidence X-ray
Spectrometer MaGIXS. We find that many line intensity ratios are sensitive to
both and . Best diagnostic options are provided if a ratio
involving both Fe XVII and Fe XVIII is combined with another ratio involving
lines formed within a single ion. The sensitivity of such diagnostics to
is typically a few tens of per cent. Much larger sensitivity, of about
a factor of two to three, can be obtained if the Fe XVIII 93.93 A line observed
by SDO/AIA is used in conjuction with the X-ray lines. We conclude that the
MaGIXS instrument is well-suited for detection of departures from the
Maxwellian distribution, especially in active region cores.Comment: Astronomy & Astrophysics, accepte
Approaching public perceptions of datafication through the lens of inequality: a case study in public service media
In the emerging field of critical data studies, there is increasing acknowledgement that the negative effects of datafication are not experienced equally by all. Research on data and discrimination in particular has highlighted how already socially unequal populations are discriminated against in data-driven systems. Elsewhere, there is growing interest in public perceptions of datafication, amongst academic researchers interested in producing ‘bottom up’ understandings of the new roles of data in society and non-academic stakeholders keen to
establish positive perceptions of data-driven systems. However, research into public perceptions rarely engages with the issue of inequality which is so central in data and discrimination
scholarship. Bringing these two issues together, this paper explores public perceptions of datafication through the lens of inequality, focusing on the relationship between understandings
and feelings within these perceptions. The paper draws on empirical focus group research into how audiences perceive the data practices that signing in to access BBC digital services enable. The paper shows how inequalities relating to age, dis/ability, poverty and their intersections played a role in shaping perceptions and that these social inequalities informed understandings of and feelings about data practices in complex and diverse ways. It concludes with reflections on the significance of these findings for future research and for data-related policy
Parallel Actin-Independent Recycling Pathways Polarize Cdc42 in Budding Yeast
The highly conserved Rho-family GTPase Cdc42 is an essential regulator of polarity in many different cell types. During polarity establishment, Cdc42 becomes concentrated at a cortical site, where it interacts with downstream effectors to orient the cytoskeleton along the front-back axis. To concentrate Cdc42, loss of Cdc42 by diffusion must be balanced by recycling to the front. In Saccharomyces cerevisiae, the guanine nucleotide dissociation inhibitor (GDI) Rdi1 recycles Cdc42 through the cytoplasm. Loss of Rdi1 slowed but did not eliminate Cdc42 accumulation at the front, suggesting the existence of other recycling pathways. One proposed pathway involves actin-directed trafficking of vesicles carrying Cdc42 to the front. However, we found no role for F-actin in Cdc42 concentration, even in rdi1 Delta cells. Instead, Cdc42 was still able to exchange between the membrane and cytoplasm in rdi1 Delta cells, albeit at a reduced rate. Membrane-cytoplasm exchange of GDP-Cdc42 was faster than that of GTP-Cdc42, and computational modeling indicated that such exchange would suffice to promote polarization. We also uncovered a novel role for the Cdc42-directed GTPase-activating protein (GAP) Bem2 in Cdc42 polarization. Bem2 was known to act in series with Rdi1 to promote recycling of Cdc42, but we found that rdi1 Delta bem2 Delta mutants were synthetically lethal, suggesting that they also act in parallel. We suggest that GAP activity cooperates with the GDI to counteract the dissipative effect of a previously unappreciated pathway whereby GTP-Cdc42 escapes from the polarity site through the cytoplasm
Randomized controlled trial of the efficacy of aerobic exercise in reducing metabolic risk in healthy older people: The Hertfordshire Physical Activity Trial.
BACKGROUND: While there are compelling observational data confirming that individuals who exercise are healthier, the efficacy of aerobic exercise interventions to reduce metabolic risk and improve insulin sensitivity in older people has not been fully elucidated. Furthermore, while low birth weight has been shown to predict adverse health outcomes later in life, its influence on the response to aerobic exercise is unknown. Our primary objective is to assess the efficacy of a fully supervised twelve week aerobic exercise intervention in reducing clustered metabolic risk in healthy older adults. A secondary objective is to determine the influence of low birth weight on the response to exercise in this group. METHODS/DESIGN: We aim to recruit 100 participants born between 1931-1939, from the Hertfordshire Cohort Study and randomly assign them to no intervention or to 36 fully supervised one hour sessions on a cycle ergometer, over twelve weeks. Each participant will undergo detailed anthropometric and metabolic assessment pre- and post-intervention, including muscle biopsy, magnetic resonance imaging and spectroscopy, objective measurement of physical activity and sub-maximal fitness testing. DISCUSSION: Given the extensive phenotypic characterization, this study will provide valuable insights into the mechanisms underlying the beneficial effects of aerobic exercise as well as the efficacy, feasibility and safety of such interventions in this age group. TRIAL REGISTRATION: Current Controlled Trials: ISRCTN60986572.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Establishment of clinical exercise physiology as a regulated healthcare profession in the UK:a progress report
In 2021, a 'call to action' was published to highlight the need for professional regulation of clinical exercise physiologists to be established within UK healthcare systems to ensure patient safety and align training and regulation with other health professions. This manuscript provides a progress report on the actions that Clinical Exercise Physiology UK (CEP-UK) has undertaken over the past 4 years, during which time clinical exercise physiologists have implemented regulation and gained formal recognition as healthcare professionals in the UK. An overview of the consultation process involved in creating a regulated health profession, notably the development of policies and procedures for both individual registration and institutional master's degree (MSc) accreditation is outlined. Additionally, the process for developing an industry-recognised scope of practice, a university MSc-level curriculum framework, the Academy for Healthcare Science Practitioner standards of proficiency and Continuing Professional Development opportunities is included. We outline the significant activities and milestones undertaken by CEP-UK and provide insight and clarity for other health professionals to understand the training and registration process for a clinical exercise physiologist in the UK. Finally, we include short, medium and long-term objectives for the future advocacy development of this workforce in the UK.</p
Diagnostic performance of GENEDIA W and ActiveXpress+ COVID-19 antigens tests among symptomatic individuals in Peru and The United Kingdom
Objectives: In order to generate independent performance data regarding accuracy of COVID-19 antigen-based rapid diagnostic tests (Ag-RDTs), prospective diagnostic evaluation studies across multiple sites are required to evaluate their performance in different clinical settings. This report describes the clinical evaluation the GENEDIA W COVID-19 Ag Device (Green Cross Medical Science Corp., Chungbuk, Korea) and the ActiveXpress+ COVID-19 Complete Testing Kit (Edinburgh Genetics Ltd, UK), in two testing sites Peru and the United Kingdom.
Methods: Nasopharyngeal swabs collected from 456 symptomatic patients at primary points of care in Lima, Peru and 610 symptomatic participants at a COVID-19 Drive-Through testing site in Liverpool, England were analyzed by Ag-RDT and compared to RT-PCR. Analytical evaluation of both Ag-RDTs was assessed using serial dilutions of direct culture supernatant of a clinical SARS-CoV-2 isolate from the B.1.1.7 lineage.
Results: For GENEDIA brand, the values of overall sensitivity and specificity were 60.4% [95% CI 52.4–67.9%], and 99.2% [95% CI 97.6–99.7%] respectively; and for Active Xpress+ the overall values of sensitivity and specificity were 66.2% [95% CI 54.0–76.5%], and 99.6% [95% CI 97.9–99.9%] respectively. The analytical limit of detection was determined at 5.0 x 102 pfu/ml what equals to approximately 1.0 x 104 gcn/ml for both Ag-RDTs. The UK cohort had lower median Ct values compared to that of Peru during both evaluations. When split by Ct, both Ag-RDTs had optimum sensitivities at Ct<20 (in Peru; 95% [95% CI 76.4–99.1%] and 100.0% [95% CI 74.1–100.0%] and in the UK; 59.2% [95% CI 44.2–73.0%] and 100.0% [95% CI 15.8–100.0%], for the GENDIA and the ActiveXpress+, respectively).
Conclusions: Whilst the overall clinical sensitivity of the Genedia did not meet WHO minimum performance requirements for rapid immunoassays in either cohort, the ActiveXpress+ did so for the small UK cohort. This study illustrates comparative performance of Ag-RDTs across two global settings and considers the different approaches in evaluation methods
The First Flight of the Marshall Grazing Incidence X-ray Spectrometer (MaGIXS)
The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) sounding rocket
experiment launched on July 30, 2021 from the White Sands Missile Range in New
Mexico. MaGIXS is a unique solar observing telescope developed to capture X-ray
spectral images, in the 6 - 24 Angstrom wavelength range, of coronal active
regions. Its novel design takes advantage of recent technological advances
related to fabricating and optimizing X-ray optical systems as well as
breakthroughs in inversion methodologies necessary to create spectrally pure
maps from overlapping spectral images. MaGIXS is the first instrument of its
kind to provide spatially resolved soft X-ray spectra across a wide field of
view. The plasma diagnostics available in this spectral regime make this
instrument a powerful tool for probing solar coronal heating. This paper
presents details from the first MaGIXS flight, the captured observations, the
data processing and inversion techniques, and the first science results.Comment: 20 pages, 18 figure
Evidence-informed obstetric practice during normal birth in China: trends and influences in four hospitals
BACKGROUND: A variety of international organizations, professional groups and individuals are promoting evidence-informed obstetric care in China. We measured change in obstetric practice during vaginal delivery that could be attributed to the diffusion of evidence-based messages, and explored influences on practice change. METHODS: Sample surveys of women at postnatal discharge in three government hospitals in Shanghai and one in neighbouring Jiangsu province carried out in 1999, repeated in 2003, and compared. Main outcome measures were changes in obstetric practice and influences on provider behaviour. "Routine practice" was defined as more than 65% of vaginal births. Semi-structured interviews with doctors explored influences on practice. RESULTS: In 1999, episiotomy was routine at all four hospitals; pubic shaving, rectal examination (to monitor labour) and electronic fetal heart monitoring were routine at three hospitals; and enema on admission was common at one hospital. In 2003, episiotomy rates remained high at all hospitals, and actually significantly increased at one; pubic shaving was less common at one hospital; one hospital stopped rectal examination for monitoring labour, and the one hospital where enemas were common stopped this practice. Mobility during labour increased in three hospitals. Continuous support was variable between hospitals at baseline and showed no change with the 2003 survey. Provider behaviour was mainly influenced by international best practice standards promoted by hospital directors, and national legislation about clinical practice. CONCLUSION: Obstetric practice became more evidence-informed in this selected group of hospitals in China. Change was not directly related to the promotion of evidence-based practice in the region. Hospital directors and national legislation seem to be particularly important influences on provider behaviour at the hospital level
Evangelical Christianity and Women’s Changing Lives
Women have outnumbered men as followers of Christianity at least since the transition to industrial capitalist modernity in the West. Yet developments in women's lives in relation to employment, family and feminist values are challenging their Christian religiosity. Building on a new strand of gender analysis in the sociology of religion, this article argues that gender is central to patterns of religiosity and secularization in the West. It then offers a case study of evangelical Christianity in England to illustrate how changes in women's lives are affecting their religiosity. Specifically, it argues that evangelical Christianity continues to be important among women occupying more traditional social positions (as wives and mothers), but adherence is declining among the growing number whose lives do not fit this older model
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