8,668 research outputs found
Norman Julius Zabusky OBITUARY
Norman Julius Zabusky, who laid the foundations for several critical advancements in nonlinear science and experimental mathematics, died of idiopathic pulmonary fibrosis on 5 February 2018 in Beersheba, Israel. He also made fundamental contributions to computational fluid dynamics and advocated the importance of visualization in science.Published versio
Did doubling reserve requirements cause the recession of 1937-1938? a microeconomic approach
In 1936-37, the Federal Reserve doubled the reserve requirements imposed on member banks. Ever since, the question of whether the doubling of reserve requirements increased reserve demand and produced a contraction of money and credit, and thereby helped to cause the recession of 1937-1938, has been a matter of controversy. Using microeconomic data to gauge the fundamental reserve demands of Fed member banks, we find that despite being doubled, reserve requirements were not binding on bank reserve demand in 1936 and 1937, and therefore could not have produced a significant contraction in the money multiplier. To the extent that increases in reserve demand occurred from 1935 to 1937, they reflected fundamental changes in the determinants of reserve demand and not changes in reserve requirements.Money supply ; Bank reserves ; Recessions
Higgs Boson Decays to Neutralinos in Low-Scale Gauge Mediation
We study the decays of a standard model-like MSSM Higgs boson to pairs of
neutralinos, each of which subsequently decays promptly to a photon and a
gravitino. Such decays can arise in supersymmetric scenarios where
supersymmetry breaking is mediated to us by gauge interactions with a
relatively light gauge messenger sector (M_{mess} < 100 TeV). This process
gives rise to a collider signal consisting of a pair of photons and missing
energy. In the present work we investigate the bounds on this scenario within
the minimal supersymmetric standard model from existing collider data. We also
study the prospects for discovering the Higgs boson through this decay mode
with upcoming data from the Tevatron and the LHC.Comment: 18 pages, 5 figures, added references and discussion of neutralino
couplings, same as journal versio
Measuring and modeling optical diffraction from subwavelength features
We describe a technique for studying scattering from subwavelength features. A simple scatterometer was developed to measure the scattering from the single-submicrometer, subwavelength features generated with a focused ion beam system. A model that can describe diffraction from subwavelength features with arbitrary profiles is also presented and shown to agree quite well with the experimental measurements. The model is used to demonstrate ways in which the aspect ratios of subwavelength ridges and trenches can be obtained from scattering data and how ridges can be distinguished from trenches over a wide range of aspect ratios. We show that some earlier results of studies on distinguishing pits from particles do not extend to low-aspect-ratio features
Introduction: Celebrating the Mound City Bar Association Centennial: Looking Back, Leading Forward
In 2022, the Mound City Bar Association in St. Louis, one of the first Black bar associations in the country, celebrates its 100th anniversary. In this volume of the Washington University Journal of Law & Policy, distinguished authors look back at a century of contributions of Mound City Bar Association lawyers, judges, and allies, documenting their efforts to eliminate racial discrimination and break down barriers to equal justice. The volume is a testament to the work of countless individuals in the fight for civil rights since the beginning of the association in 1922. The authors also anticipate and examine the challenges ahead and the work yet to be done to achieve equal justice for all in our city, the region, and the country in the years to come
Conventional versus highly cross-linked polyethylene in primary total knee replacement : a comparison of revision rates using data from the National Joint Registry for England, Wales, and Northern Ireland
There is evidence to support the use of highly cross-linked polyethylene (HXLPE) in patients undergoing total hip arthroplasty. However, the benefits for those undergoing total knee arthroplasty are uncertain, with conflicting reports based on previous cohort analyses. The purpose of the present study was to compare the revision rates following primary total knee arthroplasty with use of HXLPE as compared with conventional polyethylene (CPE) using data from the National Joint Registry (NJR) for England, Wales and Northern Ireland. We performed a retrospective analysis of primary total knee arthroplasties recorded in the NJR from 2003 to 2014. Cobalt-chromium (CoCr)-CPE and CoCr-HXLPE bearing surfaces were compared using all-cause revision, aseptic revision, and septic revision as end points. Survival analyses were conducted using rates per 100 years observed, Kaplan-Meier survival estimates, and Cox regression hazard ratios (HRs) adjusted for age, sex, American Society of Anesthesiologists (ASA) classification, body mass index (BMI), lead surgeon grade, and implant constraint. Secondary analyses compared the most commonly used HXLPEs (Zimmer Prolong, DePuy XLK, and Stryker X3) against CPE for the 3 most common total knee arthroplasty systems (NexGen, PFC Sigma, and Triathlon). In the present study of 550,658 total knee arthroplasties, the unadjusted aseptic revision rates were significantly lower following procedures performed with CPE (n = 513,744) as compared with those performed with HXLPE total knee replacements (n = 36,914) (0.29 [95% confidence interval (CI), 0.28 to 0.30] compared to 0.38 [95% CI, 0.35 to 0.42], p 35 kg/m, the "second-generation" Stryker X3 HXLPE demonstrated significantly better survival than its respective CPE, with CPE having an HR of 2.6 (95% CI, 1.2 to 5.9) (p = 0.02). Alternative bearings are marketed as having improved wear properties over traditional CoCr-CPE. This registry-based analysis demonstrated no overall survival benefit of HXLPE after a maximum duration of follow-up of 12 years. Because of their increased cost, the routine use of HXLPE bearings may not be justified. However, they may have a role in specific "higher demand" groups such as patients 35 kg/m. Therapeutic Level III. See Instructions for Authors for a complete list of levels of evidence
Randomised, controlled trial of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers : PRESSURE (pressure relieving support surfaces) trial
Objective To compare whether differences exist between alternating pressure overlays and alternating pressure mattresses in the development of new pressure ulcers, healing of existing pressure ulcers, and patient acceptability. Design Pragmatic, open, multicentre, randomised controlled trial. Setting 11 hospitals in six NHS trusts. Participants 1972 people admitted to hospital as acute or elective patients. Interventions Participants were randomised to an alternating pressure mattress (n = 982) of- an alternating pressure overlay (n = 990). Main outcome measures The proportion of participants developing a new pressure ulcer of grade 2 or worse; time to development of new pressure ulcers; proportions of participants developing a new ulcer within 30 days; healing of existing pressure ulcers; and patient acceptability Results Intention to treat analysis found no difference in the proportions of participants developing a new pressure ulcer of grade 2 or worse (10.7% overlay patients, 10.3% mattress patients; difference 0.4%, 95% confidence interval - 23% to 3.1%, P = 0.75). More overlay patients requested change owing to dissatisfaction (23.3%) than mattress patients (18.9%, P = 0.02). Conclusion No difference was found between alternating pressure mattresses and alternating pressure overlays in the proportion of people who develop a pressure ulcer
Evolving UK policy on diversity in the armed services: multiculturalism and its discontents
Reflecting a generally multiculturalist rhetoric, UK policy in this area has hitherto focussed on enhancing the degree to which the armed services represent or reflect the ethnic makeup of the UK population. Ambitious targets have been set and some progress made in moving towards them. However, the dynamics of population change, together with the diverse preferences of ethno-religious minorities, have meant that the goal of representativeness has remained out of reach. At the same time, the armed services have continued to struggle with an ongoing recruitment problem while the volume of operational commitments has shown little sign of reducing
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