68 research outputs found

    Design and development of a multifunctional surgical device for ground and space-based surgical applications.

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    With the possibility of longer ventures into space, NASA will face many new medical challenges. The ability to surgically treat trauma and other disorders in reduced gravity requires reliable wound access, containment, and visualization. In collaboration with Carnegie Mellon University, the University of Louisville is currently developing the AISS (Aqueous Immersion Surgical System) to increase efficiency and control of the operative field in space-based surgeries. Reliable wound access and containment is achieved by placing a transparent wound-isolation dome securely over the wound-site and pressurizing it with a saline solution. Leak-free trocars provide access ports for various surgical instruments. This system will prevent contamination of the environment from blood and other bodily fluids, control bleeding, provide a sterile microenvironment for surgical intervention, and maintain visualization of the operative field. The objective of this project is to develop a Multifunctional Surgical Device (MFSD) that is compatible will the AISS system and conventional ground-based surgical techniques. Economy and efficiency of instrument exchange are necessary given the limited resources and number of crew members on an exploration space flight. The MFSD aims to provide suction, irrigation, illumination, visualization, and cautery functionality through a single-instrument via finger-tip control. This multifunctionality will reduce intraoperative blood loss and help maintain visualization of the operative field by removing blood and debris. Also, the MFSD will help preserve surgical focus and minimize surgeon manual movement and instrument exchanges. Applicability of the MFSD for ground-based surgical procedures is also anticipated. This project has been successful in developing a multifunctional device that integrates suction, irrigation, and illumination. Testing of these three functions has been performed on the benchtop and in a live-animal model using a stand-alone control system. After completing the myRIO integration of the MFSD with the Fluid Management System (FMS), further testing will allow for validation of device functionality and efficacy with the AISS. Future work for this project will include preparing for a suborbital space flight of the AISS on the Virgin Galactic SpaceShipTwo planned for later 2018. This flight test will evaluate irrigating, illuminating, and suctioning analog blood from a simulated wound-site in microgravity. The addition of cutting and coagulation cautery and visualization functions is planned for subsequent months. Earth-based development and utilization of the MFSD for surgical procedures is also anticipated

    Ethnicity and the Writing of Medieval Scottish history

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    Historians have long tended to define medieval Scottish society in terms of interactions between ethnic groups. This approach was developed over the course of the long nineteenth century, a formative period for the study of medieval Scotland. At that time, many scholars based their analysis upon scientific principles, long since debunked, which held that medieval 'peoples' could only be understood in terms of 'full ethnic packages'. This approach was combined with a positivist historical narrative that defined Germanic Anglo-Saxons and Normans as the harbingers of advances of Civilisation. While the prejudices of that era have largely faded away, the modern discipline still relies all too often on a dualistic ethnic framework. This is particularly evident in a structure of periodisation that draws a clear line between the 'Celtic' eleventh century and the 'Norman' twelfth. Furthermore, dualistic oppositions based on ethnicity continue, particularly in discussions of the law, kingship, lordship and religion

    Summary Document

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    This summary is based on the following larger document: Sauchyn, Dave; Barrow, Elaine; Fang, X; Henderson, Norm; Johnston, Mark; Pomeroy, John; Thorpe, Jeff; Wheaton, Elaine; Williams, B. 2009. Saskatchewan’s Natural Capital in a Changing Climate: An Assessment of Impacts and Adaptation, PARC, Regina, 162pp. The full report is viewable on the PARC website at www.parc.caSummary edited by Dave Sauchyn and Norm Henderson.PARC acknowledges the funding support of Saskatchewan Environment.Non-Peer ReviewedClimate change impacts in Saskatchewan are already evident and will become increasing significant over time. This report draws on the expertise of top climate change researchers and a large body of previous work to create a state-of-knowledge synthesis of key biophysical impacts and adaptation options specific to Saskatchewan. The focus is Saskatchewan’s ecosystems and water resources and the sectors of our economy, agriculture, and forestry, which are most dependent on these natural resources. The purpose of this report is to 1) document the expected impacts of climate change on Saskatchewan’s natural resources and dependent industries, and 2) outline options for adaptation of resource management practices, policies and infrastructure to minimize the risks associated with the impacts of climate change and to take advantage of opportunities provided by a warming climate

    Effects of a high-dose 24-h infusion of tranexamic acid on death and thromboembolic events in patients with acute gastrointestinal bleeding (HALT-IT): an international randomised, double-blind, placebo-controlled trial

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    Background: Tranexamic acid reduces surgical bleeding and reduces death due to bleeding in patients with trauma. Meta-analyses of small trials show that tranexamic acid might decrease deaths from gastrointestinal bleeding. We aimed to assess the effects of tranexamic acid in patients with gastrointestinal bleeding. Methods: We did an international, multicentre, randomised, placebo-controlled trial in 164 hospitals in 15 countries. Patients were enrolled if the responsible clinician was uncertain whether to use tranexamic acid, were aged above the minimum age considered an adult in their country (either aged 16 years and older or aged 18 years and older), and had significant (defined as at risk of bleeding to death) upper or lower gastrointestinal bleeding. Patients were randomly assigned by selection of a numbered treatment pack from a box containing eight packs that were identical apart from the pack number. Patients received either a loading dose of 1 g tranexamic acid, which was added to 100 mL infusion bag of 0·9% sodium chloride and infused by slow intravenous injection over 10 min, followed by a maintenance dose of 3 g tranexamic acid added to 1 L of any isotonic intravenous solution and infused at 125 mg/h for 24 h, or placebo (sodium chloride 0·9%). Patients, caregivers, and those assessing outcomes were masked to allocation. The primary outcome was death due to bleeding within 5 days of randomisation; analysis excluded patients who received neither dose of the allocated treatment and those for whom outcome data on death were unavailable. This trial was registered with Current Controlled Trials, ISRCTN11225767, and ClinicalTrials.gov, NCT01658124. Findings: Between July 4, 2013, and June 21, 2019, we randomly allocated 12 009 patients to receive tranexamic acid (5994, 49·9%) or matching placebo (6015, 50·1%), of whom 11 952 (99·5%) received the first dose of the allocated treatment. Death due to bleeding within 5 days of randomisation occurred in 222 (4%) of 5956 patients in the tranexamic acid group and in 226 (4%) of 5981 patients in the placebo group (risk ratio [RR] 0·99, 95% CI 0·82–1·18). Arterial thromboembolic events (myocardial infarction or stroke) were similar in the tranexamic acid group and placebo group (42 [0·7%] of 5952 vs 46 [0·8%] of 5977; 0·92; 0·60 to 1·39). Venous thromboembolic events (deep vein thrombosis or pulmonary embolism) were higher in tranexamic acid group than in the placebo group (48 [0·8%] of 5952 vs 26 [0·4%] of 5977; RR 1·85; 95% CI 1·15 to 2·98). Interpretation: We found that tranexamic acid did not reduce death from gastrointestinal bleeding. On the basis of our results, tranexamic acid should not be used for the treatment of gastrointestinal bleeding outside the context of a randomised trial

    Investigation of hospital discharge cases and SARS-CoV-2 introduction into Lothian care homes

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    Background The first epidemic wave of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in Scotland resulted in high case numbers and mortality in care homes. In Lothian, over one-third of care homes reported an outbreak, while there was limited testing of hospital patients discharged to care homes. Aim To investigate patients discharged from hospitals as a source of SARS-CoV-2 introduction into care homes during the first epidemic wave. Methods A clinical review was performed for all patients discharges from hospitals to care homes from 1st March 2020 to 31st May 2020. Episodes were ruled out based on coronavirus disease 2019 (COVID-19) test history, clinical assessment at discharge, whole-genome sequencing (WGS) data and an infectious period of 14 days. Clinical samples were processed for WGS, and consensus genomes generated were used for analysis using Cluster Investigation and Virus Epidemiological Tool software. Patient timelines were obtained using electronic hospital records. Findings In total, 787 patients discharged from hospitals to care homes were identified. Of these, 776 (99%) were ruled out for subsequent introduction of SARS-CoV-2 into care homes. However, for 10 episodes, the results were inconclusive as there was low genomic diversity in consensus genomes or no sequencing data were available. Only one discharge episode had a genomic, time and location link to positive cases during hospital admission, leading to 10 positive cases in their care home. Conclusion The majority of patients discharged from hospitals were ruled out for introduction of SARS-CoV-2 into care homes, highlighting the importance of screening all new admissions when faced with a novel emerging virus and no available vaccine

    SARS-CoV-2 Omicron is an immune escape variant with an altered cell entry pathway

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    Vaccines based on the spike protein of SARS-CoV-2 are a cornerstone of the public health response to COVID-19. The emergence of hypermutated, increasingly transmissible variants of concern (VOCs) threaten this strategy. Omicron (B.1.1.529), the fifth VOC to be described, harbours multiple amino acid mutations in spike, half of which lie within the receptor-binding domain. Here we demonstrate substantial evasion of neutralization by Omicron BA.1 and BA.2 variants in vitro using sera from individuals vaccinated with ChAdOx1, BNT162b2 and mRNA-1273. These data were mirrored by a substantial reduction in real-world vaccine effectiveness that was partially restored by booster vaccination. The Omicron variants BA.1 and BA.2 did not induce cell syncytia in vitro and favoured a TMPRSS2-independent endosomal entry pathway, these phenotypes mapping to distinct regions of the spike protein. Impaired cell fusion was determined by the receptor-binding domain, while endosomal entry mapped to the S2 domain. Such marked changes in antigenicity and replicative biology may underlie the rapid global spread and altered pathogenicity of the Omicron variant

    Scenarios of climate change for the European Community

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    Two methods of climate scenario construction were developed, based on the output of general circulation models (GCMs), to provide a suite of possible future climate scenarios to be used by impact modellers. The first involved the construction of a composite pattern of climate change derived from the output of seven GCMs, while the second was based on the individual output of three GCMs run in equilibrium mode. The composite scenarios indicated a consistent pattern, but altered magnitude, of climate change over time. In summer, warming was uniform over most of Europe, whereas in winter, warming was greater in northern Europe. There was much more variability in the pattern of precipitation change because of large differences in the precipitation patterns of the individual GCMs used in the construction of the composite. In summer, a decrease in precipitation may occur in southern Mediterranean countries, either no change or a decrease in central Europe and either no change or an increase in northern Europe. An increase in precipitation is likely in winter in central and northern Europe, no change or an increase in southern Europe and no change or a decrease in southern Spain, Italy and Greece. Individual GCMs showed considerable geographical variation in both the magnitude and pattern of climate change, especially for precipitation. For temperature, the magnitude of the warming was similar for all models

    Use of a stochastic weather generator in the development of climate change scenarios

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    Abstract. Climate change scenarios with a high spatial and temporal resolution are required in the evaluation of the effects of climate change on agricultural potential and agricultural risk. Such scenarios should reproduce changes in mean weather characteristics as well as incorporate the changes in climate variability indicated by the global climate model (GCM) used. Recent work on the sensitivity of crop models and climatic extremes has clearly demonstrated that changes in variability can have more profound effects on crop yield and on the probability of extreme weather events than simple changes in the mean values. The construction of climate change scenarios based on spatial regression downscaling and on the use of a local stochastic weather generator is described. Regression downscaling translated the coarse resolution GCM grid-box predictions of climate change to site-specific values. These values were then used to perturb the parameters of the stochastic weather generator in order to simulate site-specific daily weather data. This approach permits the incorporation of changes in the mean and variability of climate in a consistent and computationally inexpensive way. The stochastic weather generator used in this study, LARS-WG, has been validated across Europe and has been shown to perform well in the simulation of different weather statistics, including those climatic extremes relevant to agriculture. The importance of downscaling and the incorporation of climate variability are demonstrated at two European sites where climate change scenarios were constructed using the UK Met. Office high resolution GCM equilibrium and transient experiments. 1
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