256 research outputs found
Gravity wave turbulence in a laboratory flume
We present an experimental study of the statistics of surface gravity wave turbulence in a flume of a horizontal size 12×6 m. For a wide range of amplitudes the wave energy spectrum was found to scale as Eω∼ω-ν in a frequency range of up to one decade. However, ν appears to be nonuniversal: it depends on the wave intensity and ranges from about 6 to 4. We discuss our results in the context of existing theories and argue that at low wave amplitudes the wave statistics is affected by the flume finite size, and at high amplitudes the wave breaking effect dominates
Fair Allocation of Vaccines, Ventilators and Antiviral Treatments: Leaving No Ethical Value Behind in Health Care Rationing
COVID-19 has revealed limitations of existing mechanisms for rationing
medical resources under emergency scenarios. Many argue that these mechanisms
abandon various ethical values such as equity by discriminating against
disadvantaged communities. Illustrating that these limitations are aggravated
by a restrictive choice of mechanism, we formulate pandemic rationing of
medical resources as a new application of market design and propose a reserve
system as a resolution. We develop a general theory of reserve design,
introduce new concepts such as cutoff equilibria and smart reserves, extend
analysis of previously-known ones such as sequential reserve matching, relate
these concepts to current debates, and present preliminary policy impact.Comment: Keywords: ethical rationing, reserve system, COVID-19, vaccines,
ventilator
Rationing Safe and Effective COVID-19 Vaccines: Allocating to States Proportionate to Population May Undermine Commitments to Mitigating Health Disparities
A central goal in the National Academies of Science, Engineering and Medicine’s (NASEM) framework for equitable COVID-19 vaccine allocation is to mitigate existing inequities, particularly those affecting economically worse-off racial and ethnic minorities. The Advisory Committee on Immunization Practice (ACIP) likewise notes that equity demands to “reduce, rather than increase, health disparities in each phase of vaccine distribution”. A crucial question in this regard is how vaccines should be distributed to states. The default is to allocate proportionate to population size. However, this approach risks increasing scarcity for worse-off populations in states where they represent above-average shares. To avoid lower odds of receiving a vaccine for worse-off groups, more vaccines could be given to states with larger shares of worse-off populations, and fewer to ones with smaller shares. We show here the consequences of allocating by these two different approaches
Overview of a Cyber-enabled Wireless Monitoring System for the Protection and Management of Critical Infrastructure Systems
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/84821/1/OverviewSHMTech.pd
Actinomyces in Chronic Granulomatous Disease: An Emerging and Unanticipated Pathogen
Background.Chronic granulomatous disease (CGD) is a rare inherited disease of the phagocyte NADPH oxidase system that causes defective production of toxic oxygen metabolites, impaired bacterial and fungal killing, and recurrent life-threatening infections, mostly by catalase-producing organisms. We report for the first time, to our knowledge, chronic infections with Actinomyces species in 10 patients with CGD. Actinomycosis is a chronic granulomatous condition that commonly manifests as cervicofacial, pulmonary, or abdominal disease, caused by slowly progressive infection with oral and gastrointestinal commensal Actinomyces species. Treatment of actinomycosis is usually simple in immunocompetent individuals, requiring long-term, high-dose intravenous penicillin, but is more complicated in those with CGD because of delayed diagnosis and an increased risk of chronic invasive or debilitating disease. Methods.Actinomyces was identified by culture, staining, 16S ribosomal DNA polymerase chain reaction, and/or a complement fixation test in 10 patients with CGD. Results.All 10 patients presented with a history of fever and elevated inflammatory signs without evident focus. Diagnosis was delayed and clinical course severe and protracted despite high-dose intravenous antibiotic therapy and/or surgery. These results suggest an unrecognized and unanticipated susceptibility to weakly pathogenic Actinomyces species in patients with CGD because these are catalase-negative organisms previously thought to be nonpathogenic in CGD. Conclusions.Actinomycosis should be vigorously sought and promptly treated in patients with CGD presenting with uncommon and prolonged clinical signs of infection. Actinomycosis is a catalase-negative infection important to consider in CG
Intra-operative real time intracranial subarachnoid haemorrhage during glial tumour resection: A case report
Glial tumours associated with subarachnoid haemorrhage are very rare. A 64-year-old woman admitted with a history of 3 weeks seizures and a left sided hemiparesis and dysphasia. The magnetic resonance disclosed heterogeneously enhancing a right temporal mass. During surgery, suddenly an abrupt and extensive swelling had occurred both in tumour and the brain tissue. The surgery was completed with a gross total tumour resection together with a partial temporal lobectomy. Postoperative computerized tomography demonstrated a massive subarachnoid hemorrhage (SAH). A cerebral Magnetic Resonance (MR) angiography showed neither an aneurysm nor arteriovenous malformation. Coincidence of an intracerebral tumour and subarachnoid haemorrhage would be devastating
Categorized priority systems: a new tool for fairly allocating scarce medical resources in the face of profound social inequities
The coronavirus disease 2019 (COVID-19) pandemic has motivated medical ethicists and several task forces to revisit or issue new guidelines on allocating scarce medical resources. Such guidelines are relevant for the allocation of scarce therapeutics and vaccines and for allocation of ICU beds, ventilators, and other life-sustaining treatments or potentially scarce interventions. Principles underlying these guidelines, like saving the most lives, mitigating disparities, reciprocity to those who assume additional risk (eg, essential workers and clinical trial participants), and equal access may compete with one another. We propose the use of a “categorized priority system” (also known as a “reserve system”) as an improvement over existing allocation methods, particularly because it may be able to achieve disparity mitigation better than other methods
Categorized priority systems: a new tool for fairly allocating scarce medical resources in the face of profound social inequities
The coronavirus disease 2019 (COVID-19) pandemic has motivated medical ethicists and several task forces to revisit or issue new guidelines on allocating scarce medical resources. Such guidelines are relevant for the allocation of scarce therapeutics and vaccines and for allocation of ICU beds, ventilators, and other life-sustaining treatments or potentially scarce interventions. Principles underlying these guidelines, like saving the most lives, mitigating disparities, reciprocity to those who assume additional risk (eg, essential workers and clinical trial participants), and equal access may compete with one another. We propose the use of a “categorized priority system” (also known as a “reserve system”) as an improvement over existing allocation methods, particularly because it may be able to achieve disparity mitigation better than other methods
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