130 research outputs found

    Human cadaver endovascular training :the establishment and validation of a fresh frozen pulsatile human cadaver endovascular training model

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    MD ThesisAIMS: The current study had the following aims: 1. Establish an effective pulsatile human cadaver pulsatile flow model (PHCM). 2. Explore the acceptability of PHCM 3. Assess the face and construct validity of PHCM. 4. Compare the effectiveness and transferability of endovascular skills taught on PHCM versus a virtual reality simulator (VRS). 5. Examine the role of video-enhanced feedback during technical skills training. METHODS: 1. Cadaveric experiments were conducted at a licensed research facility: Newcastle Surgical Training Centre (NSTC). 2. Structured questionnaires were used to explore public and professional opinion. 3. Face and construct validity were assessed in a standard manner using practitioners of varying levels of experience. 4. Novice candidates were recruited and completed the same training regime on PHCM or VRS before crossing over onto the alternate model to compare the effectiveness of PMCH and transferability of endovascular skills. All performances were recorded and scored by two blinded experts using a validated clinical scoring tool. 5. Novice candidates were assessed performing a basic suturing exercise before and after varying forms of feedback (including video enhanced feedback). RESULTS: 1. A PHCM was successfully created. 2. Patients and professionals support cadaveric endovascular training but expressed some reservations over its feasibility. 3. Expert practitioners confirmed the models face validity. PHCM has construct validity in differentiating between novice candidates and both intermediate (p=0.000)* level and expert (p=0.000) practitioners (improved overall procedure score (OPS)). 4. PHCM training improved candidate’s quantitative parameters (Time p=0.000, Fluoroscopy p=0.026, Contrast p=0.008) and clinical performance scores (p=0.000)*. Both PHCM and VRS demonstrated transferability of basic endovascular skills. 5. Video feedback is superior to a structured lecture (OPS) and individualized feedback was not superior to unsupervised video-enhanced feedback (p=1.000*). CONCLUSION: PHCM is a feasible, valid and effective model for training basic endovascular skills. The role of unsupervised video feedback could further enhance technical skills training and warrants further investigatioMedtronic

    Mineralogy of sulfides

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    Metal sulphides are the most important group of ore minerals. As shown in this brief introduction, much is known about their compositions, crystal structures, phase relations and paragenesis. Much less is known about their surface chemistry and, in particular, about their biogeochemistry, and about the formation and behaviour of ‘nanoparticle’ sulphides, whether formed abiotically or biogenically. These are large and complex topics which can only be touched upon in this article which also serves to direct readers to more comprehensive accounts

    Comparison of Indirect Calorimetry- and Accelerometry-Based Energy Expenditure During Children‘s Discrete Skill Performance

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    To compare children’s energy expenditure (EE) levels during object projection skill performance (OPSP; e.g., kicking, throwing, striking) as assessed by hip- and wrist-worn accelerometers. Method: Forty-two children (female n = 20, Mage = 8.1 ± 0.8 years) performed three, nine-minute sessions of kicking, over-arm throwing, and striking at performance intervals of 6, 12, and 30 seconds. EE was estimated using indirect calorimetry (COSMED k4b2) and accelerometers (ActiGraph GT3X+) worn on three different locations (hip, dominant-wrist, and non-dominant-wrist) using four commonly used cut-points. Bland-Altman plots were used to analyze the agreement in EE estimations between accelerometry and indirect calorimetry (METS). Chi-square goodness of fit tests were used to examine the agreement between accelerometry and indirect calorimetry. Results: Hip- and wrist-worn accelerometers underestimated EE, compared to indirect calorimetry, during all performance conditions. Skill practice at a rate of two trials per minute resulted in the equivalent of moderate PA and five trials per minute resulted in vigorous PA (as measured by indirect calorimetry), yet was only categorized as light and/or moderate activity by all measured forms of accelerometry. Conclusion: This is one of the first studies to evaluate the ability of hip- and wrist-worn accelerometers to predict PA intensity levels during OPSP in children. These data may significantly impact PA intervention measurement strategies by revealing the lack of validity in accelerometers to accurately predict PA levels during OPSP in children

    Between Metropole and Province: circulating botany in British museums, 1870–1940

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    Exchange of duplicate specimens was an important element of the relationship between metropolitan and regional museums in the period 1870–1940. Evidence of transfers of botanical museum objects such as economic botany specimens is explored for the Royal Botanic Gardens, Kew, and six museums outside the capital: Cambridge University Botanical Museum, National Museum Wales, Glasgow Museums, Liverpool World Museum, Manchester Museum and Warrington Museum. Botany became an important element in these museums soon after their foundation, sometimes relying heavily on Kew material as in the case of Glasgow and Warrington, and usually with a strong element of economic botany (except in the case of Cambridge). Patterns of exchange depended on personal connections and rarely took the form of symmetrical relationships. Botanical displays declined in importance at various points between the 1920s and 1960s, and today only Warrington Museum has a botanical gallery open to the public. However, botanical objects are finding new roles in displays on subjects such as local history, history of collections, natural history and migration

    Adaptive capacity beyond the household: a systematic review of empirical social-ecological research

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    The concept of adaptive capacity has received significant attention within social-ecological and environmental change research. Within both the resilience and vulnerability literatures specifically, adaptive capacity has emerged as a fundamental concept for assessing the ability of social-ecological systems to adapt to environmental change. Although methods and indicators used to evaluate adaptive capacity are broad, the focus of existing scholarship has predominately been at the individual- and household- levels. However, the capacities necessary for humans to adapt to global environmental change are often a function of individual and societal characteristics, as well as cumulative and emergent capacities across communities and jurisdictions. In this paper, we apply a systematic literature review and co-citation analysis to investigate empirical research on adaptive capacity that focus on societal levels beyond the household. Our review demonstrates that assessments of adaptive capacity at higher societal levels are increasing in frequency, yet vary widely in approach, framing, and results; analyses focus on adaptive capacity at many different levels (e.g. community, municipality, global region), geographic locations, and cover multiple types of disturbances and their impacts across sectors. We also found that there are considerable challenges with regard to the ‘fit’ between data collected and analytical methods used in adequately capturing the cross-scale and cross-level determinants of adaptive capacity. Current approaches to assessing adaptive capacity at societal levels beyond the household tend to simply aggregate individual- or household-level data, which we argue oversimplifies and ignores the inherent interactions within and across societal levels of decision-making that shape the capacity of humans to adapt to environmental change across multiple scales. In order for future adaptive capacity research to be more practice-oriented and effectively guide policy, there is a need to develop indicators and assessments that are matched with the levels of potential policy applications

    Bi-fluorescent Staphylococcus aureus infection enables single-cell analysis of intracellular killing in vivo

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    Techniques for studying the clearance of bacterial infections are critical for advances in understanding disease states, immune cell effector functions, and novel antimicrobial therapeutics. Intracellular killing of Staphylococcus aureus by neutrophils can be monitored using a S. aureus strain stably expressing GFP, a fluorophore that is quenched when exposed to the reactive oxygen species (ROS) present in the phagolysosome. Here, we expand upon this method by developing a bi-fluorescent S. aureus killing assay for use in vivo. Conjugating S. aureus with a stable secondary fluorescent marker enables the separation of infected cell samples into three populations: cells that have not engaged in phagocytosis, cells that have engulfed and killed S. aureus, and cells that have viable internalized S. aureus. We identified ATTO647N-NHS Ester as a favorable dye conjugate for generating bi-fluorescent S. aureus due to its stability over time and invariant signal within the neutrophil phagolysosome. To resolve the in vivo utility of ATTO647N/GFP bi-fluorescent S. aureus, we evaluated neutrophil function in a murine model of chronic granulomatous disease (CGD) known to have impaired clearance of S. aureus infection. Analysis of bronchoalveolar lavage (BAL) from animals subjected to pulmonary infection with bi-fluorescent S. aureus demonstrated differences in neutrophil antimicrobial function consistent with the established phenotype of CGD

    A randomized trial comparing treatments for varicose veins

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    Supported by a grant from the Health Technology Assessment Programme of the National Institute for Health Research (06/45/02). The Health Services Research Unit is funded by the Chief Scientist Office of the Scottish Government Health Directorate. We thank Janice Cruden for her secretarial support and data management; Gladys McPherson and the programming team at the Centre for Healthcare Randomised Trials; Tracey Davidson, Lynda Constable, Jackie Ellington, Laura Elliott, and Yvonne Fernie for help with scoring the Aberdeen Varicose Vein Questionnaire; Luke Vale and Laura Ternent, our original economists in the group; members of the Project Management Group for their ongoing advice and support of the trial; members of the study team (Graeme MacLennan, Maria Prior, and Denise Bolsover) who contributed to the behavioral recovery component of the trial; the independent members of the trial steering committee (Alun Davies [chair], Ian Loftus, and Jane Nixon) and the data and safety monitoring committee (Gerry Stansby [chair], Winston Banya, and Marcus Flather); and the staff members at recruitment sites (see the Supplementary Appendix) who facilitated recruitment, treatment, and follow-up of trial participants.Peer reviewedPublisher PD

    Evaluating the feasibility and acceptability of an exercise and behaviour change intervention in socioeconomically deprived patients with peripheral arterial disease: The textpad study protocol

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    This pilot randomised controlled trial aims to assess the feasibility and acceptability of a 12-week home-based telehealth exercise and behavioural intervention delivered in socioeconomically deprived patients with peripheral artery disease (PAD). The study will also determine the preliminary effectiveness of the intervention for improving clinical and health outcomes. Sixty patients with PAD who meet the inclusion criteria will be recruited from outpatient clinic at the Freeman Hospital, United Kingdom. The intervention group will undergo telehealth behaviour intervention performed 3 times per week over 3 months. This program will comprise a home-based exercise (twice a week) and an individual lifestyle program (once per week). The control group will receive general health recommendations and advice to perform unsupervised walking training. The primary outcome will be feasibility and acceptability outcomes. The secondary outcomes will be objective and subjective function capacity, quality of life, dietary quality, physical activity levels, sleep pattern, alcohol and tobacco use, mental wellbeing, and patients’ activation. This pilot study will provide preliminary evidence of the feasibility, acceptability and effectiveness of home-based telehealth exercise and behavioural intervention delivered in socioeconomically deprived patients with PAD. In addition, the variance of the key health outcomes of this pilot study will be used to inform the sample size calculation for a future fully powered, multicentre randomized clinical trial

    Mineralogy and geochemistry of the Masa Valverde blind massive sulphide deposit, Iberian Pyrite Belt (Spain)

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    Masa Valverde is a blind, volcanic-hosted massive sulphide deposit recently discovered in the Spanish sector of the Iberian Pyrite Belt (IPB). The deposit is more than 1 km long and is located at depths between 400 and 850 m, in direct spatial association with a residual gravimetric anomaly. The ore body is concealed beneath Culm sedimentary rocks which cover the westem extension of a Hercynian age anticline, a few kilometers west of an area where older massive sulphide workings existed. The Masa Valverde deposit consists of two main ore bodies composed dominantly of massive and banded pyrite which are hosted by a volcano-sedimentary sequence made up of felsic tuffs interlayered with shale, siliceous exhalite and radiolarian chert. The abundance of sedimentary host rocks to the deposit is a feature shared by other large massive sulphide deposits in the eastem sector of the IPB and is interpreted as significant with respect to the origin of the deposit (a break in volcanic activity). The thickness of the upper massive sulphide orebody varies between a few meters and 70 m, and it consists of lenses and blankets of massive sulphides with interbedded tuff and shale and occasionally stockwork zones. The lower orebody is smaller and thinner than the upper one, but this may be due to incomplete drilling. Two types of stockwork occur beneath the massive sulphide bodies, the more common type consists of irregular and anastomosing sulphide veinlets and irregular blebs formed by replacement. Stockwork with cross-cutting, generally straight-sided, sulphide veins is, by contrast, suggestive of formation by hydraulic fracturing. The mineralogy and alteration processes of the ore and host rocks at Masa Valverde are analogous to those of other IPB massive sulphides

    Seawater-peridotite interactions : first insights from ODP Leg 209, MAR 15°N

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    Author Posting. © American Geophysical Union, 2004. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 5 (2004): Q09F26, doi:10.1029/2004GC000744.We present first results of a petrographic study of hydrothermally altered peridotites drilled during Ocean Drilling Program (ODP) Leg 209 in the 15°20′N fracture Zone area on the Mid-Atlantic Ridge (MAR). We find that serpentinization is extensive at all drill sites. Where serpentinization is incomplete, phase relations indicate two major reaction pathways. One is reaction of pyroxene to talc and tremolite, and the other is reaction of olivine to serpentine, magnetite, and brucite. We interpret these reactions in the light of recent peridotite-seawater reaction experiments and compositions of fluids venting from peridotite massifs at a range of temperatures. We suggest that the replacement of pyroxene by talc and tremolite takes place at temperatures >350°–400°C, where olivine is stable. The breakdown of olivine to serpentine, magnetite, and brucite is favored at temperatures below 250°C, where olivine reacts faster then pyroxene. High-temperature hydrothermal fluids venting at the Logatchev and Rainbow sites are consistent with rapid reaction of pyroxene and little or no reaction of olivine. Moderate-temperature fluids venting at the Lost City site are consistent with ongoing reaction of olivine to serpentine and brucite. Many completely serpentinized peridotites lack brucite and talc because once the more rapidly reacting phase is exhausted, interaction with the residual phase will change fluid pH and silica activity such that brucite or talc react to serpentine. At two sites we see strong evidence for continued fluid flow and fluid-rock interaction after serpentinization was complete. At Site 1268, serpentinites underwent massive replacement by talc under static conditions. This reaction requires either removal of Mg from or addition of Si to the system. We propose that the talc-altered rocks are Si-metasomatized and that the source of Si is likely gabbro-seawater reaction or breakdown of pyroxene deeper in the basement. The basement at Site 1268 is heavily veined, with talc and talc-oxide-sulfide veins being the most common vein types. It appears that the systems evolved from reducing (oxygen fugacity buffered by magnetite-pyrrhotite-pyrite and lower) to oxidizing (dominantly hematite). We propose that this transition is indicative of high fluid flux under retrograde conditions and that the abundance of hematite may relate to the Ca-depleted nature of the basement that prevents near-quantitative removal of seawater sulfate by anhydrite precipitation. At site 1272 we find abundant iowaite partly replacing brucite. While this is the first report of iowaite from a mid-ocean ridge setting, its presence indicates, again, fairly oxidizing conditions. Our preliminary results indicate that peridotite-seawater and serpentinite-seawater interactions can take place under a wider range of temperature and redox conditions than previously appreciated.This research used data and/or samples supplied by the Ocean Drilling Program (ODP). ODP is sponsored by the U.S. National Science Foundation (NSF) and participating countries under management of Joint Oceanographic Institutions (JOI), Inc
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