2,452 research outputs found

    SARS-CoV-2 transmission dynamics should inform policy

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    Funding: JM is supported in part by the U.S. National Institute of Allergy and Infectious Diseases [K01AI122853].It is generally agreed that striking a balance between resuming economic and social activities and keeping the effective reproductive number (R0) below 1 using non-pharmaceutical interventions is an important goal until and even after effective vaccines become available. Therefore, the need remains to understand how the virus is transmitted in order to identify high-risk environments and activities that disproportionately contribute to its spread so that effective preventative measures could be put in place. Contact tracing and household studies in particular provide robust evidence about the parameters of transmission. In this viewpoint, we discuss the available evidence from large-scale, well-conducted contact tracing studies from across the world and argue that SARS-CoV-2 transmission dynamics should inform policy decisions about mitigation strategies for targeted interventions according to the needs of the society by directing attention to the settings, activities and socioeconomic factors associated with the highest risks of transmission.PostprintPeer reviewe

    Optimising recruitment and informed consent in randomised controlled trials:the development and implementation of the QuinteT Recruitment Intervention (QRI)

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    BACKGROUND: Pragmatic randomised controlled trials (RCTs) are considered essential to determine effective interventions for routine clinical practice, but many fail to recruit participants efficiently, and some really important RCTs are not undertaken because recruitment is thought to be too difficult. The ‘QuinteT Recruitment Intervention’ (QRI) aims to facilitate informed decision making by patients about RCT participation and to increase recruitment. This paper presents the development and implementation of the QRI. METHODS: The QRI developed iteratively as a complex intervention. It emerged from the National Institute for Health Research (NIHR) ProtecT trial and has been developed further in 13 RCTs. The final version of the QRI uses a combination of standard and innovative qualitative research methods with some simple quantification to understand recruitment and identify sources of difficulties. RESULTS: The QRI has two major phases: understanding recruitment as it happens and then developing a plan of action to address identified difficulties and optimise informed consent in collaboration with the RCT chief investigator (CI) and the Clinical Trials Unit (CTU). The plan of action usually includes RCT-specific, as well as generic, aspects. The QRI can be used in two ways: it can be integrated into the feasibility/pilot or main phase of an RCT to prevent difficulties developing and optimise recruitment from the start, or it can be applied to an ongoing RCT experiencing recruitment shortfalls, with a view to rapidly improving recruitment and informed consent or gathering evidence to justify RCT closure. CONCLUSIONS: The QRI provides a flexible way of understanding recruitment difficulties and producing a plan to address them while ensuring engaged and well-informed decision making by patients. It can facilitate recruitment to the most controversial and important RCTs. QRIs are likely to be of interest to the CIs and CTUs developing proposals for ‘difficult’ RCTs or for RCTs with lower than expected recruitment and to the funding bodies wishing to promote efficient recruitment in pragmatic RCTs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13063-016-1391-4) contains supplementary material, which is available to authorized users

    Super-Ehlers in Any Dimension

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    We classify the enhanced helicity symmetry of the Ehlers group to extended supergravity theories in any dimension. The vanishing character of the pseudo-Riemannian cosets occurring in this analysis is explained in terms of Poincar\'e duality. The latter resides in the nature of regularly embedded quotient subgroups which are non-compact rank preserving.Comment: 1+55 pages; 15 Tables, 6 Figures; v2 : some clarifications added in Sec. 1 and in App.

    Constraints on Automorphic Forms of Higher Derivative Terms from Compactification

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    By dimensionally reducing the higher derivative corrections of ten-dimensional IIB theory on a torus we deduce constraints on the E_{n+1} automorphic forms that occur in d=10-n dimensions. In particular we argue that these automorphic forms involve the representation of E_{n+1} with fundamental weight \lambda^{n+1}, which is also the representation to which the string charges in d dimensions belong. We also consider a similar calculation for the reduction of higher derivative terms in eleven-dimensional M-theory.Comment: Minor corrections, to appear in JHE

    Competing health risks associated with the COVID-19 pandemic and early response : a scoping review

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    Funding: Amrita Rao is supported in part by the National Institute of Mental Health [F31MH124458]. Carrie Lyons is supported by the National Institute of Mental Health [F31MH128079] and by the National Institute of Allergy and Infectious Diseases Johns Hopkins HIV Epidemiology and Prevention Sciences Training Program [T32AI102623-08]. Julia Marcus is supported in part by the National Institute of Allergy and Infectious Diseases [K01AI122853]. Sharmistha Mishra is supported by a Tier 2 Canada Research Chair in Mathematical Modeling. Refilwe Nancy Phaswana-Mafuya is supported by the South African Medical Research Council.Background : COVID-19 has rapidly emerged as a global public health threat with infections recorded in nearly every country. Responses to COVID-19 have varied in intensity and breadth, but generally have included domestic and international travel limitations, closure of non-essential businesses, and repurposing of health services. While these interventions have focused on testing, treatment, and mitigation of COVID-19, there have been reports of interruptions to diagnostic, prevention, and treatment services for other public health threats. Objectives : We conducted a scoping review to characterize the early impact of COVID-19 on HIV, tuberculosis, malaria, sexual and reproductive health, and malnutrition. Methods : A scoping literature review was completed using searches of PubMed and preprint servers (medRxiv/bioRxiv) from November 1st, 2019 to October 31st, 2020, using Medical Subject Headings (MeSH) terms related to SARS-CoV-2 or COVID-19 and HIV, tuberculosis, malaria, sexual and reproductive health, and malnutrition. Empiric studies reporting original data collection or mathematical models were included, and available data synthesized by region. Studies were excluded if they were not written in English. Results : A total of 1604 published papers and 205 preprints were retrieved in the search. Overall, 8.0% (129/1604) of published studies and 10.2% (21/205) of preprints met the inclusion criteria and were included in this review: 7.3% (68/931) on HIV, 7.1% (24/339) on tuberculosis, 11.6% (26/224) on malaria, 7.8% (19/183) on sexual and reproductive health, and 9.8% (13/132) on malnutrition. Thematic results were similar across competing health risks, with substantial indirect effects of the COVID-19 pandemic and response on diagnostic, prevention, and treatment services for HIV, tuberculosis, malaria, sexual and reproductive health, and malnutrition. Discussion : COVID-19 emerged in the context of existing public health threats that result in millions of deaths every year. Thus, effectively responding to COVID-19 while minimizing the negative impacts of COVID-19 necessitates innovation and integration of existing programs that are often siloed across health systems. Inequities have been a consistent driver of existing health threats; COVID-19 has worsened disparities, reinforcing the need for programs that address structural risks. The data reviewed here suggest that effective strengthening of health systems should include investment and planning focused on ensuring the continuity of care for both rapidly emergent and existing public health threats.Publisher PDFPeer reviewe

    Clinical implementation of a 3D4K-exoscope (Orbeye) in microneurosurgery

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    Exoscopic surgery promises alleviation of physical strain, improved intraoperative visualization and facilitation of the clinical workflow. In this prospective observational study, we investigate the clinical usability of a novel 3D4K-exoscope in routine neurosurgical interventions. Questionnaires on the use of the exoscope were carried out. Exemplary cases were additionally video-documented. All participating neurosurgeons (n = 10) received initial device training. Changing to a conventional microscope was possible at all times. A linear mixed model was used to analyse the impact of time on the switchover rate. For further analysis, we dichotomized the surgeons in a frequent (n = 1) and an infrequent (n = 9) user group. A one-sample Wilcoxon signed rank test was used to evaluate, if the number of surgeries differed between the two groups. Thirty-nine operations were included. No intraoperative complications occurred. In 69.2% of the procedures, the surgeon switched to the conventional microscope. While during the first half of the study the conversion rate was 90%, it decreased to 52.6% in the second half (p = 0.003). The number of interventions between the frequent and the infrequent user group differed significantly (p = 0.007). Main reasons for switching to ocular-based surgery were impaired hand-eye coordination and poor depth perception. The exoscope investigated in this study can be easily integrated in established neurosurgical workflows. Surgical ergonomics improved compared to standard microsurgical setups. Excellent image quality and precise control of the camera added to overall user satisfaction. For experienced surgeons, the incentive to switch from ocular-based to exoscopic surgery greatly varies
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