Cloud cavitation on an oscillating hydrofoil

Cloud cavitation, often formed by the breakdown of a sheet or vortex cavity, is believed to be responsible for much of the noise and erosion damage that occurs under cavitating conditions. For this paper, cloud cavitation was produced through the periodic forcing of the flow by an oscillating hydrofoil. The present work examines the acoustic signal generated by the collapse of cloud cavitation, and compares the results to those obtained by studies of single travelling bubble cavitation. In addition, preliminary studies involving the use of air injection on the suction surface of the hydrofoil explore its mitigating effects on the cavitation noise

Enantioselective Total Synthesis of (—)-Acetylaranotin, a Dihydrooxepine Epidithiodiketopiperazine

The first total synthesis of the dihydrooxepine-containing epidithiodiketopiperazine (ETP) (−)-acetylaranotin (1) is reported. The key steps of the synthesis include an enantioselective azomethine ylide (1,3)-dipolar cycloaddition reaction to set the absolute and relative stereochemistry, a rhodium-catalyzed cycloisomerization/chloride elimination sequence to generate the dihydrooxepine moiety, and a stereoretentive diketopiperazine sulfenylation to install the epidisulfide. This synthesis provides access to (−)-1 in 18 steps from inexpensive, commercially available starting materials. We anticipate that the approach described herein will serve as a general strategy for the synthesis of additional members of the dihydrooxepine ETP family

Identifying candidates for targeted gait rehabilitation: better prediction through biomechanics-informed characterization

BACKGROUND: Walking speed has been used to predict the efficacy of gait training; however, poststroke motor impairments are heterogeneous and different biomechanical strategies may underlie the same walking speed. Identifying which individuals will respond best to a particular gait rehabilitation program using walking speed alone may thus be limited. The objective of this study was to determine if, beyond walking speed, participants' baseline ability to generate propulsive force from their paretic limbs (paretic propulsion) influences the improvements in walking speed resulting from a paretic propulsion-targeting gait intervention. METHODS: Twenty seven participants >6 months poststroke underwent a 12-week locomotor training program designed to target deficits in paretic propulsion through the combination of fast walking with functional electrical stimulation to the paretic ankle musculature (FastFES). The relationship between participants' baseline usual walking speed (UWSbaseline), maximum walking speed (MWSbaseline), and paretic propulsion (propbaseline) versus improvements in usual walking speed (∆UWS) and maximum walking speed (∆MWS) were evaluated in moderated regression models. RESULTS: UWSbaseline and MWSbaseline were, respectively, poor predictors of ΔUWS (R 2  = 0.24) and ΔMWS (R 2  = 0.01). Paretic propulsion × walking speed interactions (UWSbaseline × propbaseline and MWSbaseline × propbaseline) were observed in each regression model (R 2 s = 0.61 and 0.49 for ∆UWS and ∆MWS, respectively), revealing that slower individuals with higher utilization of the paretic limb for forward propulsion responded best to FastFES training and were the most likely to achieve clinically important differences. CONCLUSIONS: Characterizing participants based on both their walking speed and ability to generate paretic propulsion is a markedly better approach to predicting walking recovery following targeted gait rehabilitation than using walking speed alone

Information/Systems and Quantitative Core Courses in AACSB Accredited Business Schools

During the 1994 academic year, a survey was conducted of institutions accredited by the American Assembly of Collegiate Schools of Business (AACSB). The purpose of the survey was to determine the nature and characteristics of the quantitative and Information Systems core courses. The results, which were contrasted to those of a similar survey done in 1987, provide a snapshot of the current status of these core classes, reveal evolutionary changes, and portend possible future trends

Who Thinks Treaties are Like Contracts? Not John Marshall

Courts in the United States are fond of analogizing treaties to contracts. The U.S. Supreme Court has done so on numerous occasions, as have nearly all federal circuit courts. Indeed, the treaty-as-contract trope has permeated U.S. legal discourse since at least the early 1800s when Chief Justice John Marshall wrote in Foster v. Neilson that “[a] treaty is in its nature a contract between two nations, not a legislative act.

Relationship between hyperuricemia with deposition and sexual dysfunction in males and females

Purpose The association between gout, the most common crystal arthropathy, and sexual dysfunctions has often been investigated by studies in the last decades. Despite the presence of shared risk factors and comorbidities and the possible effects on sexual health of long-term gout complications, awareness of this association is severely lacking and the pathogenetic mechanisms have only partially been identified. In the present review, we aimed to investigate the current evidence regarding the potential mechanisms linking sexual dysfunctions and gout. Methods A comprehensive literature search within PubMed was performed to provide a summary of currently available evidence regarding the association between gout and sexual dysfunctions. Results Gout and sexual dysfunctions share several risk factors, including diabesity, chronic kidney disease, hypertension, metabolic syndrome, and peripheral vascular disease. Gout flares triggered by intense inflammatory responses feature severe pain and disability, resulting in worse sexual function, and some, but not all, treatments can also impair sexual health. Long-term gout complications can result in persistent pain and disability due to joint deformity, fractures, or nerve compression, with negative bearing on sexual function. The presence of low-grade inflammation impairs both sex steroids synthesis and endothelial function, further advancing sexual dysfunctions. The psychological burden of gout is another issue negatively affecting sexual health. Conclusions According to currently available evidence, several biological and psychological mechanisms link sexual dysfunctions and gout. Addressing risk factors and providing adequate treatment could potentially have beneficial effects on both conditions. Appropriate clinical evaluation and multidisciplinary approach are recommended to improve patient care

Catalytic asymmetric synthesis of highly substituted pyrrolizidines

A catalytic asymmetric double (1,3)-dipolar cycloaddition reaction has been developed. Using a chiral silver catalyst, enantioenriched pyrrolizidines can be prepared in one flask from inexpensive, commercially available starting materials. The pyrrolizidine products contain a variety of substitution patterns and as many as six stereogenic centers

Cooperative action in eukaryotic gene regulation: physical properties of a viral example

The Epstein-Barr virus (EBV) infects more than 90% of the human population, and is the cause of several both serious and mild diseases. It is a tumorivirus, and has been widely studied as a model system for gene (de)regulation in human. A central feature of the EBV life cycle is its ability to persist in human B cells in states denoted latency I, II and III. In latency III the host cell is driven to cell proliferation and hence expansion of the viral population, but does not enter the lytic pathway, and no new virions are produced, while the latency I state is almost completely dormant. In this paper we study a physico-chemical model of the switch between latency I and latency III in EBV. We show that the unusually large number of binding sites of two competing transcription factors, one viral and one from the host, serves to make the switch sharper (higher Hill coefficient), either by cooperative binding between molecules of the same species when they bind, or by competition between the two species if there is sufficient steric hindrance.Comment: 7 pages, 6 figures, 1 tabl