529 research outputs found
Electrocatalytic CO2 reduction by M(bpy-R)(CO)4 (M = Mo, W; R = H, tBu) complexes. Electrochemical, spectroscopic, and computational studies and comparison with group 7 catalysts
The tetracarbonyl molybdenum and tungsten complexes of 2,2âČ-bipyridine and 4,4âČ-di-tert-butyl-2,2âČ-bipyridine (M(bpy-R)(CO)4; R = H, M = Mo (1), W (2); R = tBu, M = Mo (3), W (4)) are found to be active electrocatalysts for the reduction of CO2. The crystal structures of M(bpy-tBu)(CO)4 (M = Mo (3), W (4)), the singly reduced complex [W(bpy)(CO)4][K(18-crown-6] (5) and the doubly reduced complex [W(bpy-tBu)(CO)3][K(18-crown-6)]2 (6) are reported. DFT calculations have been used to characterize the reduced species from the reduction of W(bpy-tBu)(CO)4 (4). These compounds represent rare examples of group 6 electrocatalysts for CO2 reduction, and comparisons are made with the related group 7 complexes that have been studied extensively for CO2 reduction
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"Am iz kwiin" (I'm his queen): Combining interpretative phenomenological analysis with a feminist approach to work with gems in a resource-constrained setting
This article focuses on working with gems using a feminist approach to interpretative phenomenological analysis (IPA) in a resource-constrained setting. The research explores the experiences of maternal disclosure of HIV to children of HIV positive mothers in Kingston, Jamaica. A feminist approach helps recognise power imbalances within research relationships and the womenâs lived experiences. We present three âgemsâ which illuminate womenâs lived experiences and explore how popularised representations of womenâs sexuality and mothering influence disclosure discourses. We use emotion work as a conceptual resource to structure the womenâs narratives and challenge existing policy discourses, which arguably represent disclosure within a binary, rationalist, decision-making framework. This article adds to global literature on maternal HIV disclosure and problematises policy discourses by bringing into relief the emotion work women engage in when deciding if and how to communicate their HIV status to their children. It adds to the body of research using IPA, particularly in resource-constrained settings where IPA has thus far had little application
Testing Scalar-Tensor Gravity with Gravitational-Wave Observations of Inspiralling Compact Binaries
Observations of gravitational waves from inspiralling compact binaries using
laser-interferometric detectors can provide accurate measures of parameters of
the source. They can also constrain alternative gravitation theories. We
analyse inspiralling compact %binaries in the context of the scalar-tensor
theory of Jordan, Fierz, Brans and Dicke, focussing on the effect on the
inspiral of energy lost to dipole gravitational radiation, whose source is the
gravitational self-binding energy of the inspiralling bodies. Using a
matched-filter analysis we obtain a bound on the coupling constant of Brans-Dicke theory. For a neutron-star/black-hole binary, we find that
the bound could exceed the current bound of from
solar-system experiments, for sufficiently low-mass systems. For a neutron star and a black hole we find that a bound
is achievable. The bound decreases with
increasing black-hole mass. For binaries consisting of two neutron stars, the
bound is less than 500 unless the stars' masses differ by more than about . For two black holes, the behavior of the inspiralling binary is
observationally indistinguishable from its behavior in general relativity.
These bounds assume reasonable neutron-star equations of state and a detector
signal-to-noise ratio of 10.Comment: 10 pages, (3 figures upon request), WUGRAV-94-
Gravitational waveforms from inspiralling compact binaries to second-post-Newtonian order
The two independent ``plus" and ``cross" polarization waveforms associated
with the gravitational waves emitted by inspiralling, non-spinning, compact
binaries are presented, ready for use in the data analysis of signals received
by future laser interferometer gravitational-wave detectors such as LIGO and
VIRGO. The computation is based on a recently derived expression of the
gravitational field at the second-post-Newtonian approximation of general
relativity beyond the dominant (Newtonian) quadrupolar field. The use of these
theoretical waveforms to make measurements of astrophysical parameters and to
test the nature of relativistic gravity is discussed.Comment: 17 pages; To appear in Classical and Quantum Gravit
A 'place based' approach to work and employment: the end of reciprocity, ordinary working families and 'giggers' in a place
The authors define âplace basingâ as the study of work and employment in a particular place. They are interested in understanding the limitations of work opportunities therein and so focus on workers and jobs that are not subject to the threat of off-shoring or relocation elsewhere but which are low paid and insecure. The authors theorize three contributions to new knowledge that flow from a place-based study of work and employment by demonstrating how precarious flexible often zero hour work eschews reciprocity between employer and employees and workers. They focus their research on ordinary working families and the âpermissive visibilityâ of bad work. The research points to an idealized model of individual and family economic functioning that is able to cope with physical and mental challenges individually without burdening the state. As the findings on workers and households demonstrate, this ideal is far from the reality they experience
Counterfactuals and revisionism in historical explanation
This article addresses the role of counterfactuals in historical and ethnohistorical explanation. Drawing primarily on examples from the Conquest of Mexico, it argues (1) for a useful role for counterfactual analysis, not in writing fiction, but in assessing pivotal causation and proofing causal arguments; (2) for a clearer understanding of causation in historical records, especially of ethnohistorical subjects; and (3) for a way in which this perspective can be employed to argue for solidly grounded revisionist interpretations of events.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
Contesting longstanding conceptualisations of urban green space
Ever since the Victorian era saw the creation of âparks for the people,â health and wellbeing benefits have been considered a primary benefit of urban parks and green spaces. Today, public health remains a policy priority, with illnesses and conditions such as diabetes, obesity and depression a mounting concern, notably in increasingly urbanised environments. Urban green space often is portrayed as a nature-based solution for addressing such health concerns. In this chapter, Meredith Whitten investigates how the health and wellbeing benefits these spaces provide are limited by a narrow perspective of urban green space. Whitten explores how our understandings of urban green space remain rooted in Victorian ideals and calls into question how fit for purpose they are in twenty-first-century cities. Calling on empirical evidence collected in three boroughs in London with changing and increasing demographic populations, she challenges the long-held cultural underpinnings that lead to urban green space being portrayed âas a panacea to urban problems, yet treating it as a âcosmetic afterthoughtââ (Whitten, M, Reconceptualising green space: planning for urban green space in the contemporary city. Doctoral thesis, London School of Economics and Political Science, London, U.K. http://etheses.lse.ac.uk/. Accessed 12 Jun 2019, 2019b, p 18)
Global, regional, and national estimates of the population at increased risk of severe COVID-19 due to underlying health conditions in 2020: a modelling study
Background:
The risk of severe COVID-19 if an individual becomes infected is known to be higher in older individuals and those with underlying health conditions. Understanding the number of individuals at increased risk of severe COVID-19 and how this varies between countries should inform the design of possible strategies to shield or vaccinate those at highest risk.
Methods:
We estimated the number of individuals at increased risk of severe disease (defined as those with at least one condition listed as âat increased risk of severe COVID-19â in current guidelines) by age (5-year age groups), sex, and country for 188 countries using prevalence data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 and UN population estimates for 2020. The list of underlying conditions relevant to COVID-19 was determined by mapping the conditions listed in GBD 2017 to those listed in guidelines published by WHO and public health agencies in the UK and the USA. We analysed data from two large multimorbidity studies to determine appropriate adjustment factors for clustering and multimorbidity. To help interpretation of the degree of risk among those at increased risk, we also estimated the number of individuals at high risk (defined as those that would require hospital admission if infected) using age-specific infectionâhospitalisation ratios for COVID-19 estimated for mainland China and making adjustments to reflect country-specific differences in the prevalence of underlying conditions and frailty. We assumed males were twice at likely as females to be at high risk. We also calculated the number of individuals without an underlying condition that could be considered at increased risk because of their age, using minimum ages from 50 to 70 years. We generated uncertainty intervals (UIs) for our estimates by running low and high scenarios using the lower and upper 95% confidence limits for country population size, disease prevalences, multimorbidity fractions, and infectionâhospitalisation ratios, and plausible low and high estimates for the degree of clustering, informed by multimorbidity studies.
Findings:
We estimated that 1·7 billion (UI 1·0â2·4) people, comprising 22% (UI 15â28) of the global population, have at least one underlying condition that puts them at increased risk of severe COVID-19 if infected (ranging from <5% of those younger than 20 years to >66% of those aged 70 years or older). We estimated that 349 million (186â787) people (4% [3â9] of the global population) are at high risk of severe COVID-19 and would require hospital admission if infected (ranging from <1% of those younger than 20 years to approximately 20% of those aged 70 years or older). We estimated 6% (3â12) of males to be at high risk compared with 3% (2â7) of females. The share of the population at increased risk was highest in countries with older populations, African countries with high HIV/AIDS prevalence, and small island nations with high diabetes prevalence. Estimates of the number of individuals at increased risk were most sensitive to the prevalence of chronic kidney disease, diabetes, cardiovascular disease, and chronic respiratory disease.
Interpretation:
About one in five individuals worldwide could be at increased risk of severe COVID-19, should they become infected, due to underlying health conditions, but this risk varies considerably by age. Our estimates are uncertain, and focus on underlying conditions rather than other risk factors such as ethnicity, socioeconomic deprivation, and obesity, but provide a starting point for considering the number of individuals that might need to be shielded or vaccinated as the global pandemic unfolds.
Funding:
UK Department for International Development, Wellcome Trust, Health Data Research UK, Medical Research Council, and National Institute for Health Research
Efficacy and safety of two neutralising monoclonal antibody therapies, sotrovimab and BRII-196 plus BRII-198, for adults hospitalised with COVID-19 (TICO): a randomised controlled trial
BACKGROUND: We aimed to assess the efficacy and safety of two neutralising monoclonal antibody therapies (sotrovimab [Vir Biotechnology and GlaxoSmithKline] and BRII-196 plus BRII-198 [Brii Biosciences]) for adults admitted to hospital for COVID-19 (hereafter referred to as hospitalised) with COVID-19. METHODS: In this multinational, double-blind, randomised, placebo-controlled, clinical trial (Therapeutics for Inpatients with COVID-19 [TICO]), adults (aged â„18 years) hospitalised with COVID-19 at 43 hospitals in the USA, Denmark, Switzerland, and Poland were recruited. Patients were eligible if they had laboratory-confirmed SARS-CoV-2 infection and COVID-19 symptoms for up to 12 days. Using a web-based application, participants were randomly assigned (2:1:2:1), stratified by trial site pharmacy, to sotrovimab 500 mg, matching placebo for sotrovimab, BRII-196 1000 mg plus BRII-198 1000 mg, or matching placebo for BRII-196 plus BRII-198, in addition to standard of care. Each study product was administered as a single dose given intravenously over 60 min. The concurrent placebo groups were pooled for analyses. The primary outcome was time to sustained clinical recovery, defined as discharge from the hospital to home and remaining at home for 14 consecutive days, up to day 90 after randomisation. Interim futility analyses were based on two seven-category ordinal outcome scales on day 5 that measured pulmonary status and extrapulmonary complications of COVID-19. The safety outcome was a composite of death, serious adverse events, incident organ failure, and serious coinfection up to day 90 after randomisation. Efficacy and safety outcomes were assessed in the modified intention-to-treat population, defined as all patients randomly assigned to treatment who started the study infusion. This study is registered with ClinicalTrials.gov, NCT04501978. FINDINGS: Between Dec 16, 2020, and March 1, 2021, 546 patients were enrolled and randomly assigned to sotrovimab (n=184), BRII-196 plus BRII-198 (n=183), or placebo (n=179), of whom 536 received part or all of their assigned study drug (sotrovimab n=182, BRII-196 plus BRII-198 n=176, or placebo n=178; median age of 60 years [IQR 50-72], 228 [43%] patients were female and 308 [57%] were male). At this point, enrolment was halted on the basis of the interim futility analysis. At day 5, neither the sotrovimab group nor the BRII-196 plus BRII-198 group had significantly higher odds of more favourable outcomes than the placebo group on either the pulmonary scale (adjusted odds ratio sotrovimab 1·07 [95% CI 0·74-1·56]; BRII-196 plus BRII-198 0·98 [95% CI 0·67-1·43]) or the pulmonary-plus complications scale (sotrovimab 1·08 [0·74-1·58]; BRII-196 plus BRII-198 1·00 [0·68-1·46]). By day 90, sustained clinical recovery was seen in 151 (85%) patients in the placebo group compared with 160 (88%) in the sotrovimab group (adjusted rate ratio 1·12 [95% CI 0·91-1·37]) and 155 (88%) in the BRII-196 plus BRII-198 group (1·08 [0·88-1·32]). The composite safety outcome up to day 90 was met by 48 (27%) patients in the placebo group, 42 (23%) in the sotrovimab group, and 45 (26%) in the BRII-196 plus BRII-198 group. 13 (7%) patients in the placebo group, 14 (8%) in the sotrovimab group, and 15 (9%) in the BRII-196 plus BRII-198 group died up to day 90. INTERPRETATION: Neither sotrovimab nor BRII-196 plus BRII-198 showed efficacy for improving clinical outcomes among adults hospitalised with COVID-19. FUNDING: US National Institutes of Health and Operation Warp Speed
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