749 research outputs found

    Enabling lunar and space missions by laser power transmission

    Get PDF
    Applications are proposed for laser power transmission on the Moon. A solar-pumped laser in lunar orbit would beam power to the lunar surface for conversion into either electricity or propulsion needs. For example, lunar rovers could be much more flexible and lighter than rovers using other primary power sources. Also, laser power could be absorbed by lunar soil to create a hard glassy surface for dust-free roadways and launch pads. Laser power could also be used to power small lunar rockets or orbital transfer vehicles, and finally, photovoltaic laser converters could power remote excavation vehicles and human habitats. Laser power transmission is shown to be a highly flexible, enabling primary power source for lunar missions

    The impact of COVID-19 on surgical training:a systematic review

    Get PDF

    Regional variations and deprivation are linked to poorer access to laparoscopic and robotic colorectal surgery: a national study in England

    Get PDF
    Background: Laparoscopic and now robotic colorectal surgery has rapidly increased in prevalence; however, little is known about how uptake varies by region and sociodemographics. The aim of this study was to quantify the uptake of minimally invasive colorectal surgery (MIS) over time and variations by region, sociodemographics and ethnicity. Methods: Retrospective analysis of routinely collected healthcare data (Clinical Practice Research Datalink linked to Hospital Episode Statistics) for all adults having elective colorectal resectional surgery in England from 1 January 2006 to 31 March 2020. Sociodemographics between modalities were compared and the association between sociodemographic factors, region and year on MIS was compared in multivariate logistic regression analysis. Results: A total of 93,735 patients were included: 52,098 open, 40,622 laparoscopic and 1015 robotic cases. Laparoscopic surgery surpassed open in 2015 but has plateaued; robotic surgery has rapidly increased since 2017, representing 3.2% of cases in 2019. Absolute differences up to 20% in MIS exist between regions, OR 1.77 (95% CI 1.68–1.86) in South Central and OR 0.75 (95% CI 0.72–0.79) in the North West compared to the largest region (West Midlands). MIS was less common in the most compared to least deprived (14.6% of MIS in the most deprived, 24.8% in the least, OR 0.85 95% CI 0.81–0.89), with a greater difference in robotic surgery (13.4% vs 30.5% respectively). Female gender, younger age, less comorbidity, Asian or ‘Other/Mixed’ ethnicity and cancer indication were all associated with increased MIS. Conclusions: MIS has increased over time, with significant regional and socioeconomic variations. With rapid increases in robotic surgery, national strategies for procurement, implementation, equitable distribution and training must be created to avoid worsening health inequalities

    Lunar Lava Tube Radiation Safety Analysis

    Get PDF
    For many years it has been suggested that lava tubes on the Moon could provide an ideal location for a manned lunar base, by providing shelter from various natural hazards, such as cosmic radiation, meteorites, micrometeoroids, and impact crater ejecta, and also providing a natural environmental control, with a nearly constant temperature, unlike that of the lunar surface showing extreme variation in its diurnal cycle. An analysis of radiation safety issues on lunar lava tubes has been performed by considering radiation from galactic cosmic rays (GCR) and Solar Particle Events (SPE) interacting with the lunar surface, modeled as a regolith layer and rock. The chemical composition has been chosen as typical of the lunar re-ions where the largest number of lava tube candidates are found. Particles have been transported all through the regolith and the rock, and received particles flux and doses have been calculated. The radiation safety of lunar lava tubes environments has been demonstrated

    'The heart of what we do': policies on teaching, learning and assessment in the learning and skills sector

    Get PDF
    One of the stated aims of government policy in England is to put teaching, training,and learning at the heart of the learning and skills system. This paper provides a critical review of policies on teaching, learning and assessment in the learning and skills sector over the past five years. It draws upon data collected and analysed in the early stages of an ESRC-funded Teaching and Learning Research Programme project. Using evidence from policy sources, we argue that despite policy rhetoric about devolution of responsibility to the 'front line', the dominant 'images' that government has of putting teaching, learning and assessment at the heart of the Learning and Skills Sector involves a narrow concept of learning and skills; an idealisation of learner agency lacking an appreciation of the pivotal role of the learner/tutor relationship and a top-down view of change in which central government agencies are relied on to secure education standards

    Laser-powered lunar base

    Get PDF
    The objective was to compare a nuclear reactor-driven Sterling engine lunar base power source to a laser-to-electric converter with orbiting laser power station, each providing 1 MW of electricity to the lunar base. The comparison was made on the basis of total mass required in low-Earth-orbit for each system. This total mass includes transportation mass required to place systems in low-lunar orbit or on the lunar surface. The nuclear reactor with Sterling engines is considered the reference mission for lunar base power and is described first. The details of the laser-to-electric converter and mass are discussed. The next two solar-driven high-power laser concepts, the diode array laser or the iodine laser system, are discussed with associated masses in low-lunar-orbit. Finally, the payoff for laser-power beaming is summarized

    Challenging the 'New Professionalism': from managerialism to pedagogy?

    Get PDF
    In recent years there have been changes made to the conceptualisation of continuing professional development for teachers in both the Scottish and English systems of education. These changes have been instigated by successive UK governments (and more recently, by the Scottish Executive), together with the General teaching Council for Scotland (GTCS) and the General Teaching Council for England (GTCE). This paper argues that these changes have not provided a clear rationale for CPD, but instead have introduced tensions between the concept of teacher education and that of training. The need for a less confused understanding of CPD and its purposes is underlined, as is the need for school based approaches to continuing teacher education. Arguably, teacher education must move from technicist emphases to a model which integrates the social processes of change within society and schools with the individual development and empowerment of teachers

    Translation of immunomodulatory therapy to treat chronic heart failure: Preclinical studies to first in human

    Get PDF
    BACKGROUND: Inflammation has been associated with progression and complications of chronic heart failure (HF) but no effective therapy has yet been identified to treat this dysregulated immunologic state. The selective cytopheretic device (SCD) provides extracorporeal autologous cell processing to lessen the burden of inflammatory activity of circulating leukocytes of the innate immunologic system. AIM: The objective of this study was to evaluate the effects of the SCD as an extracorporeal immunomodulatory device on the immune dysregulated state of HF. HF. METHODS AND RESULTS: SCD treatment in a canine model of systolic HF or HF with reduced ejection fraction (HFrEF) diminished leukocyte inflammatory activity and enhanced cardiac performance as measured by left ventricular (LV) ejection fraction and stroke volume (SV) up to 4 weeks after treatment initiation. Translation of these observations in first in human, proof of concept clinical study was evaluated in a patient with severe HFrEFHFrEF ineligible for cardiac transplantation or LV LV assist device (LVAD) due to renal insufficiency and right ventricular dysfunction. Six hour SCD treatments over 6 consecutive days resulted in selective removal of inflammatory neutrophils and monocytes and reduction in key plasma cytokines, including tumor necrosis factor-alpha (TNF-α),), interleukin (IL)-6, IL-8, and monocyte chemoattractant protein (MCP)-1. These immunologic changes were associated with significant improvements in cardiac power output, right ventricular stroke work index, cardiac index and LVSV index…. Stabilization of renal function with progressive volume removal permitted successful LVAD implantation. CONCLUSION: This translational research study demonstrates a promising immunomodulatory approach to improve cardiac performance in HFrEFHFrEF and supports the important role of inflammation in the progression of HFHF
    • …
    corecore