2,529 research outputs found
IceCube3--a new window on the Universe
This paper gives an overview of the scientific goals of IceCube with an
emphasis on the importance of atmospheric neutrinos. Status and schedule for
completing the detector are presented.Comment: 13 pages, 6 figures, to appear in A.I.P. Conf. Proceedings, 3rd Latin
American School on Cosmic Rays, Arequipa, Peru, September, 200
Inferring random change point from left-censored longitudinal data by segmented mechanistic nonlinear models, with application in HIV surveillance study
The primary goal of public health efforts to control HIV epidemics is to
diagnose and treat people with HIV infection as soon as possible after
seroconversion. The timing of initiation of antiretroviral therapy (ART)
treatment after HIV diagnosis is, therefore, a critical population-level
indicator that can be used to measure the effectiveness of public health
programs and policies at local and national levels. However, population-based
data on ART initiation are unavailable because ART initiation and prescription
are typically measured indirectly by public health departments (e.g., with
viral suppression as a proxy). In this paper, we present a random change-point
model to infer the time of ART initiation utilizing routinely reported
individual-level HIV viral load from an HIV surveillance system. To deal with
the left-censoring and the nonlinear trajectory of viral load data, we
formulate a flexible segmented nonlinear mixed effects model and propose a
Stochastic version of EM (StEM) algorithm, coupled with a Gibbs sampler for the
inference. We apply the method to a random subset of HIV surveillance data to
infer the timing of ART initiation since diagnosis and to gain additional
insights into the viral load dynamics. Simulation studies are also performed to
evaluate the properties of the proposed method
Challenges on the interaction of models and policy for pandemic control.
The COVID-19 pandemic has seen infectious disease modelling at the forefront of government decision-making. Models have been widely used throughout the pandemic to estimate pathogen spread and explore the potential impact of different intervention strategies. Infectious disease modellers and policymakers have worked effectively together, but there are many avenues for progress on this interface. In this paper, we identify and discuss seven broad challenges on the interaction of models and policy for pandemic control. We then conclude with suggestions and recommendations for the future
Clinical leadership in service redesign using Clinical Commissioning Groups: a mixed-methods study
Background: A core component of the Health and Social Care Act 2012 (Great Britain. Health and Social Care Act 2012. London: HMSO; 2012) was the idea of devolving to general practitioners (GPs) a health service leadership role for service redesign. For this purpose, new Clinical Commissioning Groups (CCGs) were formed in the English NHS.Objectives: This research examined the extent to which, and the methods by which, clinicians stepped
forward to take up a leadership role in service redesign using CCGs as a platform.Design: The project proceeded in five phases: (1) a scoping study across 15 CCGs, (2) the design and administration of a national survey of all members of CCG governing bodies in 2014, (3) six main in-depth case studies, (4) a second national survey of governing body members in 2016, which allowed longitudinal
comparisons, and (5) international comparisons.Participants: In addition to GPs serving in clinical lead roles for CCGs, the research included insights from accountable officers and other managers and perspectives from secondary care and other provider organisations (local authority councillors and staff, patients and the public, and other relevant bodies).Results: Instances of the exercise of clinical leadership utilising the mechanism of the CCGs were strikingly varied. Some CCG teams had made little of the opportunity. However, we found other examples of clinicians stepping forward to bring about meaningful improvements in services. The most notable cases
involved the design of integrated care for frail elderly patients and others with long-term conditions. The leadership of these service redesigns required cross-boundary working with primary care, secondary care, community care and social work. The processes enabling such breakthroughs required interlocking processes of leadership across three arenas: (1) strategy-level work at CCG board level, (2) mid-range
operational planning and negotiation at programme board level and (3) the arena of practical implementation leadership at the point of delivery. The arena of the CCG board provided the legitimacy for strategic change; the programme boards worked through the competing logics of markets, hierarchy and networks; and the practice arena allowed the exercise of clinical leadership in practical problemsolving, detailed learning and routinisation of new ways of working at a common-sense everyday level.Limitations: Although the research was conducted over a 3-year period, it could be argued that a much longer period is required for CCGs to mature and realise their potential.Conclusions: Despite the variation in practice, we found significant examples of clinical leaders forging
new modes of service design and delivery. A great deal of the service redesign effort was directed at compensating for the fragmented nature of the NHS – part of which had been created by the 2012 reforms. This is the first study to reveal details of such work in a systematic way
A national prospective cohort study of SARS/COV2 pandemic outcomes in the U.S.: The CHASING COVID Cohort
Introduction: The Chasing COVID Cohort (C 3 ) study is a US-based, geographically and socio-demographically diverse sample of adults (18 and older) enrolled into a prospective cohort study during the upswing of the U.S. COVID-19 pandemic.
Methods: We used internet-based strategies to enroll C 3 participants beginning March 28th, 2020. Following baseline questionnaire completion, study participants will be contacted monthly (for 6 months) to complete assessments of engagement in non-pharmaceutical interventions (e.g., use of cloth masks, avoiding large gatherings); COVID-19 symptoms; SARS/COV2 testing and diagnosis; hospitalizations; healthcare access; and uptake of health messaging. Dried blood spot (DBS) specimens will be collected at the first follow-up assessment (last week of April 2020) and at month 3 (last week of June 2020) and stored until a validated serologic test is available.
Results: As of April 20, 2020, the number of people that completed the baseline survey and provided contact information for follow-up was 7,070. Participants resided in all 50 US states, the District of Columbia, Puerto Rico, and Guam. At least 24% of participants were frontline workers (healthcare and other essential workers). Twenty-three percent (23%) were 60+ years, 24% were Black or Hispanic, 52% were men, and 52% were currently employed. Nearly 20% reported recent COVID-like symptoms (cough, fever or shortness of breath) and a high proportion reported engaging in non-pharmaceutical interventions that reduce SARS/COV2 spread (93% avoided groups \u3e20, 58% wore masks; 73% quarantined). More than half (54%) had higher risk for severe COVID-19 illness should they become infected with SARS/COV2 based on age, underlying health conditions (e.g., chronic lung disease), or daily smoking.
Discussion: A geographically and socio-demographically diverse group of participants was rapidly enrolled in the C3 during the upswing of the SARS/COV2 pandemic. Strengths of the C3 include the potential for direct observation of, and risk factors for, seroconversion and incident COVID disease (among those with or without antibodies to SARS/COV2) in areas of active transmission
Bino variations: Effective field theory methods for dark matter direct detection
We apply effective field theory methods to compute bino-nucleon scattering, in the case where tree-level interactions are suppressed and the leading contribution is at loop order via heavy flavor squarks or sleptons. We find that leading log corrections to fixed-order calculations can increase the bino mass reach of direct detection experiments by a factor of 2 in some models. These effects are particularly large for the bino-sbottom coannihilation region, where bino dark matter as heavy as 5–10 TeV may be detected by near future experiments. For the case of stop- and selectron-loop mediated scattering, an experiment reaching the neutrino background will probe thermal binos as heavy as 500 and 300 GeV, respectively. We present three key examples that illustrate in detail the framework for determining weak scale coefficients, and for mapping onto a low-energy theory at hadronic scales, through a sequence of effective theories and renormalization group evolution. For the case of a squark degenerate with the bino, we extend the framework to include a squark degree of freedom at low energies using heavy particle effective theory, thus accounting for large logarithms through a “heavy-light current.” Benchmark predictions for scattering cross sections are evaluated, including complete leading order matching onto quark and gluon operators, and a systematic treatment of perturbative and hadronic uncertainties
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