1,684 research outputs found

    Rural General Surgery: A Review of the Current Situation and Realities from a Rural Community Practice in Central Nebraska

    Get PDF
    Purpose: To examine the reasons fewer students and residents are entering general surgery, to educate residents about the realities of rural general surgery based on the experience of three general surgeons in central Nebraska, and to suggest a strategy for individual general surgeons and for residency programs to maintain the rural surgical workforce.Methods: A systematic literature review of surveys, review articles, and editorials through PUBMED was performed. Relevant studies were included in a review of the current literature on the rural general surgery workforce, general surgery residency, fellowship training, and rural surgery education. Findings: There is an insufficient supply of general surgeons in many parts of the country, particularly in rural settings. More general surgery residents are entering into subspecialty fellowship training and fewer are practicing general surgery than in the past. Residents may have inaccurate perceptions about rural general surgery practice. Those residency programs with dedicated rural and community surgery rotations have had more success in producing rural general surgeons.Conclusions: Although specialization in surgery has many positive effects, maintenance of a general surgical workforce in rural America is crucial to the health care of many citizens. Increasing the numbers of mentoring and training programs could provide medical students and general surgery residents with more educational opportunities that may lead to increased interest in rural surgery

    Thermal Properties of LiCl-KCl Molten Salt for Nuclear Waste Separation

    Get PDF
    This project addresses both practical and fundamental scientific issues of direct relevance to operational challenges of the molten LiCl-KCl salt pyrochemical process, while providing avenues for improvements in the process. In order to understand the effects of the continually changing composition of the molten salt bath during the process, the project team will systematically vary the concentrations of rare earth surrogate elements, lanthanum, cerium, praseodymium, and neodymium, which will be added to the molten LiCl-KCl salt. They will also perform a limited number of focused experiments by the dissolution of depleted uranium. All experiments will be performed at 500 deg C. The project consists of the following tasks. Researchers will measure density of the molten salts using an instrument specifically designed for this purpose, and will determine the melting points with a differential scanning calorimeter. Knowledge of these properties is essential for salt mass accounting and taking the necessary steps to prevent melt freezing. The team will use cyclic voltammetry studies to determine redox potentials of the rare earth cations, as well as their diffusion coefficients and activities in the molten LiCl-KCl salt. In addition, the team will perform anodic stripping voltammetry to determine the concentration of the rare earth elements and their solubilities, and to develop the scientific basis for an on-line diagnostic system for in situ monitoring of the cation species concentration (rare earths in this case). Solubility and activity of the cation species are critically important for the prediction of the salt's useful lifetime and disposal

    Laboratory Evaluations of Stabilized Flue Gas Desulfurization Sludge (Scrubber Sludge) and Aggregate Mixtures

    Get PDF
    The Kentucky Transportation Research Program has completed a laboratory study involving the use of flue gas desulfurization sludge (scrubber sludge) for potential application as a highway subbase and/or embankment material. Scrubber sludge is a waste produet formed when fly ash (and other residue) is combined with a lime dust slurry filter cake and stabilized with quicklime (calcium oxide). Samples of stockpiled (field) sludge and dry sludge components were obtained from the Robert Reid Station (Big Rivers Electric Corporation) in Sebree, Kentuclty. Dry sludge components (fly ash, filter cake, and quicklime) were uaed to prepare sludge samples in the laboratory, allowing a higher degree of quality control for compariaon purposes. Mixtures for testing included scrubber sludge, scrubber sludge with pond ash (bottom ash), and scrubber sludge with dense graded limestone aggregate (DGA). One objective of laboratory analyses was the determination of optimum mixture proportions. A mixture of 20-percent scrubber sludge and 80-percent pond ash was determined to be the optimum design mix. That mixture showed significant strength gain with curing and had a static-chord modulus of elasticity approximately 118 times the compressive strength. Strength and modulus tests indicated that mixtures of scrubber sludge and pond ash were superior to mixtures of scrubber sludge and DGA. The scope of the study, however, did not permit complete explanation of these observations. An economic study showed that scrubber sludge with pond ash can be used economically as a highway subbase material, especially on low-fatigue roads, by partially replacing more expensive pavement layers. Triaxial tests and computer simulations indicated that scrubber sludge could be used as an embankment material in some applications. However, this would be economical only if suitable fill material was not available at or near the fill site

    Uncertainty in geomorphological responses to climate change

    Get PDF
    Acknowledgements We acknowledge the careful comments from two anonymous reviewers. Funding information This work was partly supported by a Middlesex University PhD Studentship to EA and a Coventry University PhD Studentship to PA. NERC for radiocarbon dating provided funding support.Peer reviewedPublisher PD

    Observable frequency shifts via spin-rotation coupling

    Get PDF
    The phase perturbation arising from spin-rotation coupling is developed as a natural extension of the celebrated Sagnac effect. Experimental evidence in support of this phase shift, however, has yet to be realized due to the exceptional sensitivity required. We draw attention to the relevance of a series of experiments establishing that circularly polarized light, upon passing through a rotating half-wave plate, is changed in frequency by twice the rotation rate. These experiments may be interpreted as demonstrating the role of spin-rotation coupling in inducing this frequency shift, thus providing direct empirical verification of the coupling of the photon helicity to rotation. A neutron interferometry experiment is proposed which would be sensitive to an analogous frequency shift for fermions. In this arrangement, polarized neutrons enter an interferometer containing two spin flippers, one of which is rotating while the other is held stationary. An observable beating in the transmitted neutron beam intensity is predicted.Comment: LaTeX, 15 pages with 4 PostScript figures, submitted to Phys. Lett.

    Physical Properties and Galactic Distribution of Molecular Clouds identified in the Galactic Ring Survey

    Full text link
    We derive the physical properties of 580 molecular clouds based on their 12CO and 13CO line emission detected in the University of Massachusetts-Stony Brook (UMSB) and Galactic Ring surveys. We provide a range of values of the physical properties of molecular clouds, and find a power-law correlation between their radii and masses, suggesting that the fractal dimension of the ISM is around 2.36. This relation, M = (228 +/- 18) R^{2.36+/-0.04}, allows us to derive masses for an additional 170 GRS molecular clouds not covered by the UMSB survey. We derive the Galactic surface mass density of molecular gas and examine its spatial variations throughout the Galaxy. We find that the azimuthally averaged Galactic surface density of molecular gas peaks between Galactocentric radii of 4 and 5 kpc. Although the Perseus arm is not detected in molecular gas, the Galactic surface density of molecular gas is enhanced along the positions of the Scutum-Crux and Sagittarius arms. This may indicate that molecular clouds form in spiral arms and are disrupted in the inter-arm space. Last, we find that the CO excitation temperature of molecular clouds decreases away from the Galactic center, suggesting a possible decline in the star formation rate with Galactocentric radius. There is a marginally significant enhancement in the CO excitation temperature of molecular clouds at a Galactocentric radius of about 6 kpc, which in the longitude range of the GRS corresponds to the Sagittarius arm. This temperature increase could be associated with massive star formation in the Sagittarius spiral arm

    Global transpiration data from sap flow measurements: the SAPFLUXNET database

    Get PDF
    Plant transpiration links physiological responses of vegetation to water supply and demand with hydrological, energy, and carbon budgets at the land–atmosphere interface. However, despite being the main land evaporative flux at the global scale, transpiration and its response to environmental drivers are currently not well constrained by observations. Here we introduce the first global compilation of whole-plant transpiration data from sap flow measurements (SAPFLUXNET, https://sapfluxnet.creaf.cat/, last access: 8 June 2021). We harmonized and quality-controlled individual datasets supplied by contributors worldwide in a semi-automatic data workflow implemented in the R programming language. Datasets include sub-daily time series of sap flow and hydrometeorological drivers for one or more growing seasons, as well as metadata on the stand characteristics, plant attributes, and technical details of the measurements. SAPFLUXNET contains 202 globally distributed datasets with sap flow time series for 2714 plants, mostly trees, of 174 species. SAPFLUXNET has a broad bioclimatic coverage, with woodland/shrubland and temperate forest biomes especially well represented (80 % of the datasets). The measurements cover a wide variety of stand structural characteristics and plant sizes. The datasets encompass the period between 1995 and 2018, with 50 % of the datasets being at least 3 years long. Accompanying radiation and vapour pressure deficit data are available for most of the datasets, while on-site soil water content is available for 56 % of the datasets. Many datasets contain data for species that make up 90 % or more of the total stand basal area, allowing the estimation of stand transpiration in diverse ecological settings. SAPFLUXNET adds to existing plant trait datasets, ecosystem flux networks, and remote sensing products to help increase our understanding of plant water use, plant responses to drought, and ecohydrological processes. SAPFLUXNET version 0.1.5 is freely available from the Zenodo repository (https://doi.org/10.5281/zenodo.3971689; Poyatos et al., 2020a). The “sapfluxnetr” R package – designed to access, visualize, and process SAPFLUXNET data – is available from CRAN.EEA Santa CruzFil: Poyatos, Rafael. Universitat AutĂČnoma de Barcelona. Bellaterra (Cerdanyola del VallĂšs); EspañaFil: Poyatos, Rafael. CREAF. Bellaterra (Cerdanyola del VallĂšs); EspañaFil: Granda, VĂ­ctor. Universitat AutĂČnoma de Barcelona. Bellaterra (Cerdanyola del VallĂšs); EspañaFil: Granda, VĂ­ctor. Joint Research Unit CREAF-CTFC. Bellaterra; EspañaFil: Flo, VĂ­ctor. Universitat AutĂČnoma de Barcelona. Bellaterra (Cerdanyola del VallĂšs); EspañaFil: Adams, Mark A. Swinburne University of Technology. Faculty of Science Engineering and Technology; Australia.Fil: Adams, Mark A. University of Sydney. School of Life and Environmental Sciences; Australia.Fil: AdorjĂĄn, BalĂĄzs. University of Debrecen. Faculty of Science and Technology. Department of Botany; HungrĂ­aFil: AguadĂ©, David. Universitat AutĂČnoma de Barcelona. Bellaterra (Cerdanyola del VallĂšs); EspañaFil: Aidar, Marcos P. M. Institute of Botany. Plant Physiology and Biochemistry; BrasilFil: Allen, Scott. University of Nevada. Department of Natural Resources and Environmental Science; Estados UnidosFil: Alvarado-Barrientos, M. Susana. Instituto de EcologĂ­a A.C. Red EcologĂ­a Funcional; MĂ©xico.Fil: Anderson-Teixeira, Kristina J. Center for Tropical Forest Science-Forest Global Earth Observatory, Smithsonian Tropical Research Institute; PanamĂĄFil: Anderson-Teixeira, Kristina J. Conservation Ecology Center. Smithsonian Conservation Biology Institute; Estados UnidosFil: Peri, Pablo Luis. Instituto Nacional de TecnologĂ­a Agropecuaria (INTA). EstaciĂłn Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina.Fil: MartĂ­nez-Vilalta, Jordi. CREAF. Bellaterra (Cerdanyola del VallĂšs); EspañaFil: MartĂ­nez-Vilalta, Jordi. Universitat AutĂČnoma de Barcelona. Bellaterra (Cerdanyola del VallĂšs); Españ

    How can frontline expertise and new models of care best contribute to safely reducing avoidable acute admissions? A mixed-methods study of four acute hospitals

    Get PDF
    BackgroundHospital emergency admissions have risen annually, exacerbating pressures on emergency departments (EDs) and acute medical units. These pressures have an adverse impact on patient experience and potentially lead to suboptimal clinical decision-making. In response, a variety of innovations have been developed, but whether or not these reduce inappropriate admissions or improve patient and clinician experience is largely unknown.AimsTo investigate the interplay of service factors influencing decision-making about emergency admissions, and to understand how the medical assessment process is experienced by patients, carers and practitioners.MethodsThe project used a multiple case study design for a mixed-methods analysis of decision-making about admissions in four acute hospitals. The primary research comprised two parts: value stream mapping to measure time spent by practitioners on key activities in 108 patient pathways, including an embedded study of cost; and an ethnographic study incorporating data from 65 patients, 30 carers and 282 practitioners of different specialties and levels. Additional data were collected through a clinical panel, learning sets, stakeholder workshops, reading groups and review of site data and documentation. We used a realist synthesis approach to integrate findings from all sources.FindingsPatients’ experiences of emergency care were positive and they often did not raise concerns, whereas carers were more vocal. Staff’s focus on patient flow sometimes limited time for basic care, optimal communication and shared decision-making. Practitioners admitted or discharged few patients during the first hour, but decision-making increased rapidly towards the 4-hour target. Overall, patients’ journey times were similar, although waiting before being seen, for tests or after admission decisions, varied considerably. The meaning of what constituted an ‘admission’ varied across sites and sometimes within a site. Medical and social complexity, targets and ‘bed pressure’, patient safety and risk, each influenced admission/discharge decision-making. Each site responded to these pressures with different initiatives designed to expedite appropriate decision-making. New ways of using hospital ‘space’ were identified. Clinical decision units and observation wards allow potentially dischargeable patients with medical and/or social complexity to be ‘off the clock’, allowing time for tests, observation or safe discharge. New teams supported admission avoidance: an acute general practitioner service filtered patients prior to arrival; discharge teams linked with community services; specialist teams for the elderly facilitated outpatient treatment. Senior doctors had a range of roles: evaluating complex patients, advising and training juniors, and overseeing ED activity.ConclusionsThis research shows how hospitals under pressure manage complexity, safety and risk in emergency care by developing ‘ground-up’ initiatives that facilitate timely, appropriate and safe decision-making, and alternative care pathways for lower-risk, ambulatory patients. New teams and ‘off the clock’ spaces contribute to safely reducing avoidable admissions; frontline expertise brings value not only by placing senior experienced practitioners at the front door of EDs, but also by using seniors in advisory roles. Although the principal limitation of this research is its observational design, so that causation cannot be inferred, its strength is hypothesis generation. Further research should test whether or not the service and care innovations identified here can improve patient experience of acute care and safely reduce avoidable admissions.FundingThe National Institute for Health Research (NIHR) Health Services and Delivery Research programme (project number 10/1010/06). This research was supported by the NIHR Collaboration for Leadership in Applied Health Research and Care South West Peninsula
    • 

    corecore