2,295 research outputs found
Measurement of the derivative 'ZW' for an oscillating aerofoil
This report presents the results of experimental
measurements of the damping derivative coefficient zw for
constant chord rigid wings of various aspect ratios having
sweepback angles of zero and 450.
The results for the rectangular wings Flow substantial
agreement with the unsteady aerofoil theory developed
by TI.P. Jones $2) The dependence of Zvi upon frequency parameter
is as given by theory and is much less than for two dimensional
flow, but the numerical results are approximately
10 per cent below the theoretical. This is attributed to the
large trailing edge angle 22° of the N.A.C.A. 0020 section
used for the model aerofoils.
The effect of sweepback is to decrease the numerical
value of z , but this effect is much less pronounced, for low
than for high aspect ratios. For aspect ratios 5 and 3
the numerical value is greater than would be given by a factor
of proportionality equal to the cosine of the angle of
sweepback.
The measurements were corrected for tunnel interference
by a method based on the theoretical work of 7.P.Jones.(1
Standard CMOS floating gate memories for non-volatile parameterisation of pulse-stream VLSI radial basis function neural networks
Igneous Rock Associations in Canada 3. Large Igneous Provinces (LIPs) in Canada and Adjacent Regions: 3 Ga to Present
Earth history is punctuated by numerous periods during which large volumes of mafic magma were emplaced. Such magmas not generated by a 'normal' spreading ridge or by subduction are termed Large Igneous Provinces (LIPs), and consist of continental flood basalts, volcanic rifted margins, oceanic plateaus, ocean basin flood basalts, submarine ridges, and seamount chains. Associated felsic rocks may also be present. LIPs of Mesozoic and Cenozoic age are typically the best preserved. Those of Paleozoic and Proterozoic age are usually more deeply eroded, and consist of flood basalt remnants and a deep-level plumbing system (of giant dyke swarms, sill provinces and layered intrusions). In the Archean the most promising LIP candidates are greenstone belts containing komatiites. Many LIPs have been linked to regional-scale uplift, continental rifting and breakup, and climatic crises. They can be used as precisely dated time markers in the stratigraphic record, and are key targets for Ni-Cu-PGE exploration. LIPs have also become a focus in the debate on the existence and nature of mantle plumes.
Canada has a rich record of LIPs. At least 80 candidates are recognized in Canada and adjacent regions, with ages ranging from 3100 to 17 Ma. We review proposed links between the LIP record of Canada and mantle plumes, continental breakup, regional uplift, and ore deposits. However, given that many mafic units in Canada remain poorly characterized, a concerted geochronology campaign with integrated paleomagnetism and geochemistry would be invaluable in expanding the application of the Canadian LIP record to solving major geological problems.
RĂSUMĂ
L'histoire de la Terre est ponctuĂ©e de nombreuses pĂ©riodes de mise en place de forts volumes de magma mafiques. De tels magmas qui ne sont pas issus de zones d'expansion « normale » ou de subduction sont appelĂ©s Grandes provinces ignĂ©es (GPI), et celles-ci sont constituĂ©es de basaltes d'Ă©panchements continentaux, de marges de fosse volcaniques, de plateaux ocĂ©aniques, d'Ă©panchements de basaltes de bassins ocĂ©aniques, de crĂȘtes sous-marines, et de chaĂźnes de monts sous-marines. Peuvent Ă©galement y ĂȘtre associĂ©es des suites de roches felsiques. GĂ©nĂ©ralement, les GPI du MĂ©sozoĂŻque et du CĂ©nozoĂŻque sont les mieux prĂ©servĂ©es. Celles du ProtĂ©rozoĂŻque et du PalĂ©ozoĂŻque sont gĂ©nĂ©ralement plus fortement Ă©rodĂ©es et sont constituĂ©es de vestiges de basaltes d'Ă©panchement et des rĂ©seaux de conduits d'origine (rĂ©seaux gĂ©ants de dykes, provinces de filons-couches et d'intrusifs stratifiĂ©es). Dans l'ArchĂ©en, les meilleurs candidats sont reprĂ©sentĂ©s par les bandes de roches vertes Ă komatiites. De nombreuses GPI ont Ă©tĂ© associĂ©es Ă des Ă©pisodes de soulĂšvement rĂ©gionaux, de dĂ©rives ou de fragmentations continentales, ainsi qu'Ă des crises climatiques. Elles peuvent servir de marqueurs temporels stratigraphiques et sont des cibles de premiĂšre importance dans l'exploration de gisements de Cu-Ni-ĂGP. Les GPI sont aussi devenues des arguments trĂšs considĂ©rĂ©s dans le dĂ©bat sur l'existence et la nature des panaches mantelliques.
Le Canada possÚde de riches archives de GPI, et au moins 80 candidatures ont été isolées sur le territoire canadien et dans les régions adjacentes, leur ùge délimitant une fourchette allant de 3 100 Ma à 17 Ma. Nous passons en revue les liens proposés entre la suite des GDI canadiennes d'une part, et celle des panaches mantelliques, des fragmentations continentales, des soulÚvements régionaux, et des gisements minéraux, d'autre part. Toutefois, vu le piÚtre état de caractérisation des unités mafiques au Canada, une campagne de caractérisation géochronologique, paléomagnétique et géochimique serait d'une valeur inestimable pour favoriser l'utilisation des GDI canadiennes pour nous aider à solutionner de grands problÚmes géologiques
Distinct motifs in the intracellular domain of human CD30 differentially activate canonical and alternative transcription factor NF-?B signaling
The TNF-receptor superfamily member CD30 is expressed on normal and malignant lymphocytes, including anaplastic large cell lymphoma (ALCL) cells. CD30 transmits multiple effects, including activation of NF-?B signaling, cell proliferation, growth arrest and apoptosis. How CD30 generates these pleiotropic effects is currently unknown. Herein we describe ALCL cells expressing truncated forms of the CD30 intracellular domain that allowed us to identify the key regions responsible for transmitting its biological effects in lymphocytes. The first region (CD30519â537) activated both the alternative and canonical NF-?B pathways as detected by p100 and I?B? degradation, IKK?-dependent transcription of both I?B? and the cyclin-dependent kinase inhibitor p21WAF1/CIP1 and induction of cell cycle arrest. In contrast, the second region of CD30 (CD30538â595) induced some aspects of canonical NF-?B activation, including transcription of I?B?, but failed to activate the alternative NF-?B pathway or drive p21WAF1/CIP1-mediated cell-cycle arrest. Direct comparison of canonical NF-?B activation by the two motifs revealed 4-fold greater p65 nuclear translocation following CD30519â537 engagement. These data reveal that independent regions of the CD30 cytoplasmic tail regulate the magnitude and type of NF-?B activation and additionally identify a short motif necessary for CD30-driven growth arrest signals in ALCL cells.<br/
What difference does ("good") HRM make?
The importance of human resources management (HRM) to the success or failure of health system performance has, until recently, been generally overlooked. In recent years it has been increasingly recognised that getting HR policy and management "right" has to be at the core of any sustainable solution to health system performance. In comparison to the evidence base on health care reform-related issues of health system finance and appropriate purchaser/provider incentive structures, there is very limited information on the HRM dimension or its impact. Despite the limited, but growing, evidence base on the impact of HRM on organisational performance in other sectors, there have been relatively few attempts to assess the implications of this evidence for the health sector. This paper examines this broader evidence base on HRM in other sectors and examines some of the underlying issues related to "good" HRM in the health sector. The paper considers how human resource management (HRM) has been defined and evaluated in other sectors. Essentially there are two sub-themes: how have HRM interventions been defined? and how have the effects of these interventions been measured in order to identify which interventions are most effective? In other words, what is "good" HRM? The paper argues that it is not only the organisational context that differentiates the health sector from many other sectors, in terms of HRM. Many of the measures of organisational performance are also unique. "Performance" in the health sector can be fully assessed only by means of indicators that are sector-specific. These can focus on measures of clinical activity or workload (e.g. staff per occupied bed, or patient acuity measures), on measures of output (e.g. number of patients treated) or, less frequently, on measures of outcome (e.g. mortality rates or rate of post-surgery complications). The paper also stresses the need for a "fit" between the HRM approach and the organisational characteristics, context and priorities, and for recognition that so-called "bundles" of linked and coordinated HRM interventions will be more likely to achieve sustained improvements in organisational performance than single or uncoordinated interventions
Developing a media center in a health care facility
The director of education approached the librarian and asked her how to make slides for a medical staff presentation. The librarian was at a loss as to how to assist the director. In another situation, the marketing department of a health care facility was approached by another department to develop and shoot a video promoting a new piece of equipment. Members of the marketing department had no idea where to begin---their experience was limited to print media
Beetles and the development of Thorne Moors, SE Yorkshire, UK
This project investigates the potential of terrestrial Coleoptera for monitoring and anticipating change in a modied raised mire ecosystem, so as to inform ongoing ecological restoration and to aid conservation management in building resilience for an uncertain future. It also investigates the potential for ecological restoration â primarily rewetting of drained and cutover peats â to conserve and restore peatland Coleoptera to areas where they have been been removed by human exploitation. The primary data for this study is an original survey of terrestrial Coleoptera, conducted over a period of seven months in 2015, and resulting in the Identification of ~12,000 individual beetles, from ~250 species. This study has identified three Research Challenges, the first of which is how to distinguish environmental signals from stochastic noise (RC 1). This is addressed by placing modern ecological data in a long-term context derived from palaeoecology. As ecologists have better access to the volume and quality of data required to produce quantitative models, whereas palaeoecologists often rely on inductive reasoning to produce environmental reconstructions based on interpretations of limited data, this study addresses a second Research Challenge; namely how to link the past to the present (RC 2) and bridge the methodological gap between palaeoecology and ecology. This study meets this challenge by placing c. 10,000 years of change of the Thorne Moors raised mire system in south east Yorkshire, England, within a panarchic framework and conceptualising change as a series of adaptive cycles, progress through which is affected by multiple drivers acting and interacting over different spatial and temporal scales. A narrative approach to environmental reconstruction is utilised, drawing on the exceptional body of palaeoecological and historical information available for the study area. Panarchy provides a theoretical framing for the complex cross-scale interactions acting across time and space up to the present day and beyond. It is accessible to palaeoecologists, ecologists and conservation practitioners alike and helps us to anticipate future directions of change. Environmental disasters and near-misses of recent years foreshadow the impending threat to socio-ecological systems posed by climate change, not least drained peatlands which are threatened with destruction from ever-frequent wildres. Thus a final Research Challenge has been identified as that of linking the academy to practitioners (RC 3). This is addressed by producing a toolkit that can guide the design of time- and cost-effective monitoring of terrestrial Coleoptera, which has been built using extensive palaeoecological and historical information, combined with analysis of modern Coleopteran data and first-hand field experience gained in the process of conducting the 2015 terrestrial Coleopteran survey.
Chapter 1 introduces key concepts such as ecological restoration, panarchy and Coleoptera as indicators in monitoring, and also introduces the study site, Thorne Moors, SE Yorkshire, England. Chapter 2 reviews the extensive palaeoecological and historical information available on Thorne Moors and uses the framework of panarchy to construct a narrative of complex cross-scale interactions between small and fast, and large and slow cycles of change from the end of the Devensian Glaciation c. 10,000 years ago, up to the present day. Chapter 3 returns to the panarchic phases of Thorne Moors outlined in Chapter 2, and examines the palaeoentomological literature to understand how these phases relate to the beetle assemblages and the changes they undergo. In the process of doing so, the study collates existing, albeit limited, knowledge of the niche preferences and traits of Coleopteran groups and species, and examines how these might relate to their fates today; whether they "declined" (thought to be extinct in the Humberhead Levels), "survived" (persist, but in precarious numbers or reliant on threatened habitats/features) or thrived (evidence, possibly anecdotal, that they have increased in numbers and/or have wider distributions). Chapter 4 outlines the methodology for the 2015 terrestrial Coleopteran survey, which considered five compartments of the moors. Chapter 5 presents the results of the terrestrial survey and considers the biases that may have affected the results. Chapter 6 analyses the results of the 2015 survey using long-term perspectives gained earlier and presents a novel application of a machine learning method â term frequency-inverse document frequency (TF-IDF) â to identify species which characterise each of the study compartments,
each with its own historical contingency and semi-independent adaptive cycle. The chapter then uses Quantitative Comparative Analysis of human impacts to understand how these species came to characterise each compartment. Chapter 7 focuses on the peatland and wetland species which are absent from the 2015 Coleopteran survey, but which are recorded as having been present in the past. A concept of cryptic diversity is used to distinguish between those that species are "hidden" (i.e. present on Thorne Moors but not recorded in the survey) from those that, circumstantial evidence suggests, are "dark" (i.e. are extinct in the region of the Humberhead Levels). This demonstrates how study of "cryptic" species can provide an additional perspective on species presence data collected by Coleopteran monitoring, which can complement discussion of why some species are present with that of why some species are absent. Chapter 8 considers the interactions between people and nature in relation to conservation ecology and ecological restoration. In doing so, it firstly contemplates the current state of peatland restoration in the UK and the barriers to the rewetting of endangered peatlands â specically neoliberal economics and its relationship to the most recent framing of conservation, "Nature-based Solutions". Secondly it argues for the importance of training and careers in ecosystem restoration monitoring that go beyond monitoring more easily monetiseable measures relating to hydrology and peat accumulation. Finally a practitioner's toolbox is presented for the utilisation of terrestrial Coleoptera in monitoring modied raised mire restoration and response to climate change
A Near-Total Decline in Caribou on Prince of Wales, Somerset, and Russell Islands, Canadian Arctic
The number of caribou (Rangifer tarandus) on Prince of Wales, Somerset, and Russell islands in the south-central Canadian Arctic declined by 98% in 15 years, from an estimated 6048 (16% calves) in 1980 to an estimated 100 (0% calves) in 1995. Those estimates were obtained by systematic aerial surveys that used the same design and methods and comparable survey coverage. We do not have the data needed to determine the rate of decrease between 1980 and 1995 or its possible causes. There is no evidence for large-scale winter mortality in any one year or few consecutive years. A probable explanation for the decline is consequential reductions in long-term survival rates, both of breeding females and of calves in their first year of life, associated with continued caribou harvesting and markedly increased wolf (Canis lupus) predation on the dwindling number of caribou through the 1980s and early 1990s. The delay in detecting the decline and the lack of understanding of its causes will handicap the development of an ecologically sound recovery plan. As previous caribou declines have been followed by recovery, some comfort may be drawn from the likelihood of unaided recovery. However, the number of caribou has declined to the point where recovery will be tenuous and lengthy, at best. Unaided recovery could easily fail to occur, so we should not be complacent, especially as extirpation of these few remaining caribou would remove a distinct genetic group and reduce the biodiversity of caribou on Canadaâs Arctic Islands.Le nombre de caribous (Rangifer tarandus) se trouvant sur les Ăźles Prince of Wales, Somerset et Russell, dans le centresud de lâArctique canadien, a chutĂ© de 98 % en 15 ans, passant dâun nombre estimĂ© Ă 6 048 (dont 16 % Ă©taient des veaux) en 1980 Ă un nombre estimĂ© Ă 100 (dont aucun veau) en 1995. Ces estimations ont Ă©tĂ© obtenues au moyen de relevĂ©s aĂ©riens systĂ©matiques recourant aux mĂȘmes dĂ©finitions, aux mĂȘmes mĂ©thodes et Ă des aires de relevĂ©s comparables. On ne possĂšde pas les donnĂ©es nĂ©cessaires pour dĂ©terminer le taux de diminution entre 1980 et 1995 ou les causes possibles de cette diminution. Par ailleurs, rien nâindique quâun taux de mortalitĂ© hivernal Ă©levĂ© a Ă©tĂ© enregistrĂ© pendant une annĂ©e quelconque ou pendant quelques annĂ©es de suite. Il se peut que le dĂ©clin du nombre de caribous enregistrĂ© dans les annĂ©es 1980 et au dĂ©but des annĂ©es 1990 soit attribuable aux rĂ©ductions correspondantes des taux de survie Ă long terme chez les femelles de reproduction et les veaux pendant leur premiĂšre annĂ©e de vie, le tout jumelĂ© au prĂ©lĂšvement continuel des caribous ainsi quâĂ la prĂ©dation grandement accrue des caribous par les loups (Canis lupus). Le retard Ă dĂ©tecter ce dĂ©clin et le manque de comprĂ©hension de ses causes pourront nuire Ă lâĂ©laboration dâun plan de rĂ©cupĂ©ration solide du point de vue Ă©cologique. Puisque les dĂ©clins prĂ©cĂ©dents de caribous ont Ă©tĂ© suivis de rĂ©cupĂ©ration, on peut se consoler en se disant quâil est possible que la rĂ©cupĂ©ration se fasse spontanĂ©ment. Cependant, le nombre de caribous a chutĂ© au point oĂč la rĂ©cupĂ©ration sera longue et difficile, mĂȘme dans le meilleur des cas. Il se peut quâil nây ait pas de rĂ©cupĂ©ration spontanĂ©e et par consĂ©quent, on ne devrait pas se contenter de cette situation, surtout puisque lâextirpation des quelques caribous qui restent pourrait Ă©liminer un groupe gĂ©nĂ©tique distinct et rĂ©duire la biodiversitĂ© du caribou dans lâarchipel Arctique canadien
Improved estimates of 222 nm far-UVC susceptibility for aerosolized human coronavirus via a validated high-fidelity coupled radiation-CFD code.
Transmission of SARS-CoV-2 by aerosols has played a significant role in the rapid spread of COVID-19 across the globe. Indoor environments with inadequate ventilation pose a serious infection risk. Whilst vaccines suppress transmission, they are not 100% effective and the risk from variants and new viruses always remains. Consequently, many efforts have focused on ways to disinfect air. One such method involves use of minimally hazardous 222 nm far-UVC light. Whilst a small number of controlled experimental studies have been conducted, determining the efficacy of this approach is difficult because chamber or room geometry, and the air flow within them, influences both far-UVC illumination and aerosol dwell times. Fortunately, computational multiphysics modelling allows the inadequacy of dose-averaged assessment of viral inactivation to be overcome in these complex situations. This article presents the first validation of the WYVERN radiation-CFD code for far-UVC air-disinfection against survival fraction measurements, and the first measurement-informed modelling approach to estimating far-UVC susceptibility of viruses in air. As well as demonstrating the reliability of the code, at circa 70% higher, our findings indicate that aerosolized human coronaviruses are significantly more susceptible to far-UVC than previously thought
Preoperative neutrophil-lymphocyte ratio and outcome from coronary artery bypass grafting
Background: An elevated preoperative white blood cell count has been associated with a worse outcome after coronary artery bypass grafting (CABG). Leukocyte subtypes, and particularly the neutrophil-lymphocyte (N/L) ratio, may however, convey superior prognostic information. We hypothesized that the N/L ratio would predict the outcome of patients undergoing surgical revascularization. Methods: Baseline clinical details were obtained prospectively in 1938 patients undergoing CABG. The differential leukocyte was measured before surgery, and patients were followed-up 3.6 years later. The primary end point was all-cause mortality. Results: The preoperative N/L ratio was a powerful univariable predictor of mortality (hazard ratio [HR] 1.13 per unit, P 3.36). Conclusion: An elevated N/L ratio is associated with a poorer survival after CABG. This prognostic utility is independent of other recognized risk factors.Peer reviewedAuthor versio
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