803 research outputs found

    Flume studies using medium sand (0.45mm)

    Get PDF
    CER58DBS2.Includes bibliographical references.The results pertaining to the progress during the first year of a comprehensive study of fluvial hydraulics, specifically roughness in alluvial channels, are presented. The report is based on the data collected by using a recirculating rectangular flume of adjustable slope, 8 feet wide, 2 feet deep, and 150 feet long with an alluvial bed of sand approximately 0. 7 foot deep. A typical river sand has been utilized. Its median diameter, d, is 0.45 mm and its relative standard deviation, σ, is 1.60. A total of 45 runs have been completed over a range of bed roughness forms extending from the plane bed with no movement to antidunes. In order to achieve this range, the discharge was varied from 2 to 21 cubic feet per second, the average velocity was varied from 0.5 to 7 feet per second, the average depth of flow was varied from 0.3 to 1.0 foot, and the slope of water surface was varied from 0.00014 to 0.01. Other variables measured included: water temperature, bed roughness, suspended sediment load, and total sediment load. Terms describing channel roughness were formulated and tested based on the data collected. The results indicate, as one possibility, that the Chezy coefficient of discharge in dimensionless form C/√g is a function of parameters involving the Froude number, viscosity of fluid, fall velocity, specific weight of the sediment, median diameter of the sediment particles and slope of the water surface. The various expressions presented were formulated on the fundamental concepts of fluid mechanics, dimensional analysis, and a detailed study of the variations of the variables measured. In the two regimes of flow the following forms of bed roughness were observed. For tranquil flow regime: plane bed without movement, ripples, dunes and transition from dunes to rapid flow forms. For rapid flow regime: plane bed with movement, standing sand waves, and antidunes. These forms of bed roughness are discussed and defined in various relationships. Other data of both a laboratory and a field nature were combined with the flume data to develop a graphical relationship in which the form of bed roughness is related to size of bed material

    A Metastasis or a Second Independent Cancer? Evaluating the Clonal Origin of Tumors Using Array-CGH Data

    Get PDF
    When a cancer patient develops a new tumor it is necessary to determine if this is a recurrence (metastasis) of the original cancer, or an entirely new occurrence of the disease. This is accomplished by assessing the histo-pathology of the lesions, and it is frequently relatively straightforward. However, there are many clinical scenarios in which this pathological diagnosis is difficult. Since each tumor is characterized by a genetic fingerprint of somatic mutations, a more definitive diagnosis is possible in principle in these difficult clinical scenarios by comparing the fingerprints. In this article we develop and evaluate a statistical strategy for this comparison when the data are derived from array comparative genomic hybridization, a technique designed to identify all of the somatic allelic gains and losses across the genome. Our method involves several stages. First a segmentation algorithm is used to estimate the regions of allelic gain and loss. Then the broad correlation in these patterns between the two tumors is assessed, leading to an initial likelihood ratio for the two diagnoses. This is then further refined by comparing in detail each plausibly clonal mutation within individual chromosome arms, and the results are aggregated to determine a final likelihood ratio. The method is employed to diagnose patients from several clinical scenarios, and the results show that in many cases a strong clonal signal emerges, occasionally contradicting the clinical diagnosis. The “quality” of the arrays can be summarized by a parameter that characterizes the clarity with which allelic changes are detected. Sensitivity analyses show that most of the diagnoses are robust when the data are of high quality

    Relational legacies impacting on veteran transition from military to civilian life: trajectories of acquisition, loss and re-formulation of a sense of belonging

    Get PDF
    The veteran cohort has been inextricably linked in the general public's mind by media generated perceptions of high risk and fear of crime, echoed in wider contemporary debates linking issues of place, social identity, social exclusion (Pain 2000) and a loss of belonging in wider communities (Walklate 1998). Despite the growing interest in the longer term outcomes of transition from military to civilian life from policy-makers, practitioners and academics, few qualitative studies explore the social and relational impacts of this transitional experience on those who have experienced it. Tensions and frustrations expressed by ex-forces personnel, engaging in addictions services with a history of engagement in the criminal justice sector, are explored through the lens of belongingness, loss and related citizenship frameworks to expose temporal impacts on the acquisition, loss and reformulation of a sense of belonging across the life course. The relevance of a significant loss of belonging in the transition from military to civilian life is useful, given the widely accepted damaging consequences of having this need thwarted. This paper concludes that a broader understanding of this largely disenfranchised grief (Doka, 2002) can enable more informed reflexive opportunities to facilitate a valued military veteran citizenship status and thereby contribute to the formulation of current policy debates concerning the veteran question

    Epidemic of illicit drug use, mechanisms of action/addiction and stroke as a health hazard

    Get PDF
    Drug abuse robs individuals of their jobs, their families, and their free will as they succumb to addiction; but may cost even more: a life of disability or even life lost due to stroke. Many illicit drugs have been linked to major cardiovascular events and other comorbidities, including cocaine, amphetamines, ecstasy, heroin, phencyclidine, lysergic acid diethylamide, and marijuana. This review focuses on available epidemiological data, mechanisms of action, particularly those leading to cerebrovascular events, and it is based on papers published in English in PubMed during 1950 through February 2011. Each drug's unique interactions with the brain and vasculature predispose even young, healthy people to ischemic or hemorrhagic stroke. Cocaine and amphetamines have the strongest association with stroke. However, the level of evidence firmly linking other drugs to stroke pathogenesis is weak. Large epidemiological studies and systematic evaluation of each drug's action on the brain and cardiovascular system are needed to reveal the full impact of drug use on the population

    Multimodal Analgesia in Orthopaedic Surgery and Presentation of a Comprehensive Postoperative Pain Protocol: A Review

    Get PDF
    Rising opioid use in the United States has now been termed an epidemic. Opioid use is associated with considerable morbidity, mortality, and cost to the healthcare system. Orthopaedic surgeons play a key role in the opioid epidemic by prescribing postoperative narcotics. Although our understanding of the quantity of narcotics to prescribe postoperatively for analgesia is progressing, there is still a paucity of data focused on routine postoperative pain protocols. The purpose of this article is to review the current options for both opioid and non-opioid analgesia and put forth a multisubspecialty orthopaedic protocol of postoperative pain. On the basis of study findings and the individual experiences of surgeons within our orthopaedic department, our comprehensive pain protocol includes the following considerations: use of non-steroidal antiinflammatory drugs on an individual basis, limited use of benzodiazepines, use of diazepam in only pediatric patients undergoing major procedures, lower doses of gabapentin after hip and knee arthroplasty, higher doses of gabapentin after spine procedures, general use of oxycodone owing to its accessibility, use of isolated opioids rather than combined forms, and close collaboration with anesthesiologists for determining use of peripheral nerve block. Our resultant comprehensive pain protocol can provide orthopaedic surgeons with a framework to build upon, which will benefit greatly from future studies that examine narcotic use with specific procedures

    Pregnancy and childbirth in English prisons : institutional ignominy and the pains of imprisonment

    Get PDF
    © 2020 The Authors. Sociology of Health & Illness published by John Wiley & Sons Ltd on behalf of Foundation for SHIL.With a prison population of approximately 9000 women in England, it is estimated that approximately 600 pregnancies and 100 births occur annually. Despite an extensive literature on the sociology of reproduction, pregnancy and childbirth among women prisoners is under‐researched. This article reports an ethnographic study in three English prisons undertaken in 2015‐2016, including interviews with 22 prisoners, six women released from prison and 10 staff members. Pregnant prisoners experience numerous additional difficulties in prison including the ambiguous status of a pregnant prisoner, physical aspects of pregnancy and the degradation of the handcuffed or chained prisoner during visits to the more public setting of hospital. This article draws on Erving Goffman's concepts of closed institutions, dramaturgy and mortification of self, Crewe et al.'s work on the gendered pains of imprisonment and Crawley's notion of ‘institutional thoughtlessness’, and proposes a new concept of institutional ignominy to understand the embodied situation of the pregnant prisoner.Peer reviewe

    Convective scaling of the average dissipation rate of temperature variance in the atmospheric surface layer

    Get PDF
    The flux of sensible heat from the land surface is related to the average rate of dissipation of temperature fluctuations in the atmospheric surface layer through the temperature variance budget equation. In many cases it is desirable to estimate the heat flux from measurement or inference of the dissipation rate. Here we study how the dissipation rate scales with atmospheric stability, using three inertial range methods to calculate the dissipation rate: power spectra, second order structure functions, and third order structure functions. Experimental data are analyzed from a pair of field experiments, during which turbulent fluctuations of velocity and temperature were measured over a broad range of neutral and unstable atmospheric flows. It is shown that the temperature dissipation rate scales with a single convective power law continuously from near-neutral to strongly unstable stratification. The dissipation scaling is found to nearly match production in the near-neutral region, but to be consistently lower than production in the more convective regimes. The convective scaling is shown to offer a simplified means of computing sensible heat flux from the dissipation rate of temperature variance
    corecore