1,094 research outputs found

    Adjuncts to pre-hospital resuscitation strategies for haemorrhagic shock and blast injury : supplemental oxygen and recombinant activated factor VII

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    M.D. ThesisExplosion is responsible for almost 80% of Coalition injuries in today’s conflicts. Haemorrhage is the leading cause of death and blast lung injury is evident in 11% of Coalition casualties surviving to reach the (UK) Field Hospital. Military prehospital evacuation times can be prolonged and the combined insults of haemorrhage and blast injury present a ‘double hit’ to oxygen delivery. Resuscitation strategies must be capable of preserving life from such trauma for several hours. Alongside fluid therapy, adjuncts to resuscitation might improve battlefield survival. This randomized controlled animal trial assessed two adjuncts: supplemental inspired oxygen and recombinant activated Factor VII (rFVIIa). Neither adjunct is currently available in the far-forward military echelon, but with modern technology, both are potentially deployable. 18 terminally anaesthetized swine were exposed to blast, controlled haemorrhage and grade IV liver laceration (uncontrolled haemorrhage). Animals were allocated randomly into three treatment groups. All animals were resuscitated with normal saline to a hypotensive systolic target (80mmHg), which continued until the 8hr end point. Thirty minutes after the onset of resuscitation each group received one of the following: single (180mcg/kg) dose of rFVIIa; supplemental oxygen (min FiO2 0.3 to maintain SaO2>95%) or the control group (breathed air throughout and received saline placebo 0.18ml/kg). 5/6 control animals died within 4 hours. Supplemental oxygen improved survival (4/6 survival to 8h endpoint, P=0.014). Single dose rFVIIa did not prolong survival compared to control (2/6 survived, p=0.65). Oxygen arrested physiological decline while control and rFVIIa animals continued to decline until death. Supplemental oxygen is a useful adjunct to fluid resuscitation in the context of haemorrhage and blast injury. Delivery of oxygen support capability to forward echelon units is recommended. By contrast, a single intravenous (pre-hospital) dose of rFVIIa was not an effective treatment for blast lung based on our model of complex battlefield injury

    Finite point configurations and projection theorems in vector spaces over finite fields

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    Title from PDF of title page (University of Missouri--Columbia, viewed on May 24, 2010).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisor: Dr. Alex Iosevich.Vita.Includes bibliographical references.Ph. D. University of Missouri--Columbia 2010.Dissertations, Academic -- University of Missouri--Columbia -- Mathematics.We study a variety of combinatorial distance and dot product related problems in vector spaces over finite fields. First, we focus on the generation of the Special Linear Group whose elements belong to a finite field with q elements. Given A [subset of] Fq, we use Fourier analytic methods to determine how large A needs to be to ensure that a certain product set contains a positive proportion of all the elements of SL₂(Fq). We also study a variety of distance and dot product sets related to the Erd̋os-Falconer distance problem. In general, the Erd̋os-Falconer distance problem asks for the number of distances determined by a set of points. The classical Erdős distance problem asks for the minimal number of distinct distances determined by a finite point set in Rd, where d [is reducible to] 2. The Falconer distance problem, which is the continuous analog of the Erd̋os distance problem, asks to find s₀ [greater than] 0 such that if the Hausdorff dimension of E is greater than s₀, then the Lebesgue measure of [symmetric difference] (E) is positive. A generalization of the Erdős-Falconer distance problem in vector spaces over finite fields is to determine the minimal [alpha] [greater than] 0 such that E contains a congruent copy of every k dimensional simplex whenever [E] [almost equal to] q [alpha]. We improve on known results (for k [greater than] 3) using Fourier analytic methods, showing that [alpha] may be taken to be d+k2 . If E is a subset of a sphere, then we get a stronger result which shows that [alpha] may be taken to be d+k -1 [over] 2

    Population pressure and global markets drive a decade of forest cover change in Africa\u27s Albertine Rift

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    Africa\u27s Albertine Rift region faces a juxtaposition of rapid human population growth and protected areas, making it one of the world\u27s most vulnerable biodiversity hotspots. Using satellite-derived estimates of forest cover change, we examined national socioeconomic, demographic, agricultural production, and local demographic and geographic variables, to assess multilevel forces driving local forest cover loss and gain outside protected areas during the first decade of this century. Because the processes that drive forest cover loss and gain are expected to be different, and both are of interest, we constructed models of significant change in each direction. Although rates of forest cover change varied by country, national population change was the strongest driver of forest loss for all countries – with a population doubling predicted to cause 2.06% annual cover loss, while doubling tea production predicted to cause 1.90%. The rate of forest cover gain was associated positively with increased production of the local staple crop cassava, but negatively with local population density and meat production, suggesting production drivers at multiple levels affect reforestation. We found a small but significant decrease in loss rate as distance from protected areas increased, supporting studies suggesting higher rates of landscape change near protected areas. While local population density mitigated the rate of forest cover gain, loss was also correlated with lower local population density, an apparent paradox, but consistent with findings that larger scale forces outweigh local drivers of deforestation. This implicates demographic and market forces at national and international scales as critical drivers of change, calling into question the necessary scales of forest protection policy in this biodiversity hotspot. Using a satellite derived estimate of forest cover change for both loss and gain added a dynamic component to more traditionally static and unidirectional studies, significantly improving our understanding of landscape processes and drivers at work

    Nanomaterial structure determination using XUV diffraction

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    Diffraction using coherent XUV radiation is used to study the structure of nanophotonic materials, in this case an ordered array of 196nm spheres. Crystal structure and defects are visible, and the nanomaterial dielectric constant determined

    Anthropometric characteristics, upper-body strength, and sprint paddling performance in competitive surfers

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    The present study examined the potential differences in anthropometric characteristics, upper-body strength, and sprint paddling performance between youth and senior competitive surfers. Twenty competitive male surfers (19.1±6.8 years, 168.2±11.3 cm, 61.7±13.6 kg) were assessed for stature, mass, arm-span, ∑ 7 site skinfold thickness, Lean-Mass Ratio (LMR, ∑ 7 site skinfold/kg body-mass), pronated pull-up 1 repetition maximum (1 RM) and sprint paddling performance from a stationary start to 15 m. Independent t-tests were used to compare potential differences between youth (n:10) and senior group (n:10) of competitive surfers, with Cohen’s Effect Size (d) applied to reflect the magnitude of any differences observed. Senior surfers were not different from youth surfers for ∑ 7 site skinfold thickness, yet had greater stature (p\u3c0.001, d=2.7) and mass (p\u3c0.001, d=2.8). Consequently, the composite lean mass ratio (body-mass/∑ 7 site skinfold thickness, LMR) was greater (p=0.001, d=1.7) in senior competitive surfers. The senior surfers were faster in the 0-15 m sprint paddle test (p\u3c0.001, d=2.9), possessed higher peak paddling velocity (p\u3c0.001, d=2.3) and had greater absolute 1 RM pull-up strength (p\u3c0.001, d=2.8) and 1 RM pull-up strength relative to body-mass (1 RM pull-up mass/subjects body-mass) (p\u3c0.001, d=2.2). The results of this study suggest that practitioners working with competitive surfers should consider the importance of sprint paddle performance in surfers, and the need to optimize lean mass and relative strength, as these factors appear to distinguish between surfers of higher and lower athletic development and competitive level in the surfing population

    The global role of kidney transplantation

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    World Kidney Day on March 8 th 2012 provides a chance to reflect on the success of kidney transplantation as a therapy for end stage kidney disease that surpasses dialysis treatments both for the quality and quantity of life that it provides and for its cost effectiveness. Anything that is both cheaper and better, but is not actually the dominant therapy, must have other drawbacks that prevent replacement of all dialysis treatment by transplantation. The barriers to universal transplantation as the therapy for end stage kidney disease include the economic limitations which, in some countries place transplantation, appropriately, at a lower priority than public health fundamentals such as clean water, sanitation and vaccination. Even in high income countries the technical challenges of surgery and the consequences of immunosuppression restrict the number of suitable recipients, but the major finite restrictions on kidney transplantation rates are the shortage of donated organs and the limited medical, surgical and nursing workforces with the required expertise. These problems have solutions which involve the full range of societal, professional, governmental and political environments. World Kidney Day is a call to deliver transplantation therapy to the one million people a year who have a right to benefit

    Strength a strong predictor of paddling performance in competitive surfers

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    Reduction of Injection-Related Risk Behaviors After Emergency Implementation of a Syringe Services Program During an HIV Outbreak

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    Objective: To describe injection-related HIV risk behaviors preimplementation and postimplementation of an emergency syringe services program (SSP) in Scott County, Indiana, after an HIV outbreak among persons who inject drugs (PWID). Design: Mixed methods retrospective pre–post intervention analysis. Methods: We analyzed routine SSP program data collected at first and most recent visit among clients with ≥2 visits, ≥7 days apart from April 4 to August 30, 2015, to quantify changes in injection-related risk behaviors. We also analyzed qualitative data collected from 56 PWID recruited in Scott County to understand factors contributing to these behaviors. Results: SSP clients included in our analysis (n = 148, 62% of all SSP clients) reported significant (P < 0.001) reductions over a median 10 weeks (range 1–23) in syringe sharing to inject (18%–2%) and divide drugs (19%–4%), sharing other injection equipment (eg, cookers) (24%–5%), and number of uses of the same syringe [2 (interquartile range: 1–4) to 1 (interquartile range: 1–1)]. Qualitative study participants described access to sterile syringes and safer injection education through the SSP, as explanatory factors for these reductions. Injection frequency findings were mixed, but overall suggested no change. The number of syringes returned by SSP clients increased from 0 at first visit to median 57. All qualitative study participants reported using sharps containers provided by the SSP. Conclusions: Analyses of an SSP program and in-depth qualitative interview data showed rapid reduction of injection-related HIV risk behaviors among PWID post-SSP implementation. Sterile syringe access as part of comprehensive HIV prevention is an important tool to control and prevent HIV outbreaks

    Sources of Variability in Iso-inertial Jump Assessments

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    Purpose: This investigation aimed to quantify the typical variation for kinetic and kinematic variables measured during loaded jump squats. Methods: Thirteen professional athletes performed six maximal effort countermovement jumps on fouroccasions. Testing occurred over 2 d, twice per day (8 AM and 2 PM) separated by 7 d, with the same procedures replicated on each occasion. Jump height, peak power (PP), relative peak power (RPP), mean power (MP), peak velocity (PV), peak force (PF), mean force (MF), and peak rate of force development (RFD) measurements were obtained from a linear optical encoder attached to a 40 kg barbell. Results: A diurnal variation in performance was observed with afternoon values displaying an average increase of 1.5-5.6% for PP, RPP, MP, PV, PF, and MF when compared with morning values (effect sizes ranging from 0.2-0.5). Day to day reliability was estimated by comparing the morning trials (AM reliability) and the afternoon trials (PM reliability). In both AM and PM conditions, all variables except RFD demonstrated coefficients of variations ranging between 0.8-6.2%. However, for a number of variables (RPP, MP, PV and height), AM reliability was substantially better than PM. PF and MF were the only variables to exhibit a coefficient of variation less than the smallest worthwhile change in both conditions. Discussion: Results suggest that power output and associated variables exhibit a diurnal rhythm, with improved performance in the afternoon. Morning testing may be preferable when practitioners are seeking to conduct regular monitoring of an athlete\u27s performance due to smaller variabilit
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