Metabolomic and flux-balance analysis of age-related decline of hypoxia tolerance in Drosophila muscle tissue

The fruit fly D. melanogaster is increasingly used as a model organism for studying acute hypoxia tolerance and for studying aging, but the interactions between these two factors are not well known. Here we show that hypoxia tolerance degrades with age in post-hypoxic recovery of whole-body movement, heart rate and ATP content. We previously used 1H NMR metabolomics and a constraint-based model of ATP-generating metabolism to discover the end products of hypoxic metabolism in flies and generate hypotheses for the biological mechanisms. We expand the reactions in the model using tissue- and age-specific microarray data from the literature, and then examine metabolomic profiles of thoraxes after 4 hours at 0.5% O2 and after 5 minutes of recovery in 40- versus 3-day-old flies. Model simulations were constrained to fluxes calculated from these data. Simulations suggest that the decreased ATP production during reoxygenation seen in aging flies can be attributed to reduced recovery of mitochondrial respiration pathways and concomitant over-dependence on the acetate production pathway as an energy source.Comment: 30 page

The effect of variations in the magnetic field direction from turbulence on kinetic-scale instabilities

At kinetic scales in the solar wind, instabilities transfer energy from particles to fluctuations in the electromagnetic fields while restoring plasma conditions towards thermodynamic equilibrium. We investigate the interplay between background turbulent fluctuations at the small-scale end of the inertial range and kinetic instabilities acting to reduce proton temperature anisotropy. We analyse in situ solar wind observations from the Solar Orbiter mission to develop a measure for variability in the magnetic field direction. We find that non-equilibrium conditions sufficient to cause micro-instabilities in the plasma coincide with elevated levels of variability. We show that our measure for the fluctuations in the magnetic field is non-ergodic in regions unstable to the growth of temperature anisotropy-driven instabilities. We conclude that the competition between the action of the turbulence and the instabilities plays a significant role in the regulation of the proton-scale energetics of the solar wind. This competition depends not only on the variability of the magnetic field but also on the spatial persistence of the plasma in non-equilibrium conditions

Novel coronavirus mitigation measures implemented by radiotherapy centres in low and middle-income countries: a systematic review.

Background: The aim of the study was to identify strategies adopted by radiotherapy centres in low- and middle-income countries (LMICs) to mitigate the effects of COVID-19. Studies summarising COVID-19 mitigation strategies designed and implemented by radiotherapy centres in LMICs to avoid delays, deferrments and interruptions of radiotherapy services are lacking. Materials and methods: A systematic review was conducted and reported in accordance with the preferred reporting items for systematic review and meta-analysis guideline. Ovid Embase, Ovid MEDLINE and CINAHL were searched for peer-reviewed articles that reported measures adopted by radiotherapy centres in LMICs to reduce the risk of COVID-19. Information on different strategies were extracted from the included studies and textual narrative synthesis was conducted. Results: Of 60 articles retrieved, eleven were included. Majority of the studies were conducted in China. Ten of the included studies employed a qualitative design. Four themes were identified: preparing and equipping staff; reinforcing infection prevention and control policies; strengthening coordination and communication; and maintaining physical distancing. Studies reported that radiotherapy centres had: formed COVID-19 response multidisciplinary team; maximised the use of telehealth; adjusted the layout of waiting areas; divided staff into teams; dedicated a room for isolating suspected cases; and adopted triage systems. Conclusions: Local adaptation of established global strategies coupled with timely development of guidelines, flexibility and innovation have allowed radiotherapy leaders to continue to deliver radiotherapy services to cancer patients in LMICs during the COVID-19 crisis. Robust data collection must be encouraged in LMICs to provide an evidence-based knowledge for use in the event of another pandemic

An extremal effective survey about extremal effective cycles in moduli spaces of curves

We survey recent developments and open problems about extremal effective divisors and higher codimension cycles in moduli spaces of curves.Comment: Submitted to the Proceedings of the Abel Symposium 2017. Comments are welcom

The Disunity of Consciousness

It is commonplace for both philosophers and cognitive scientists to express their allegiance to the "unity of consciousness". This is the claim that a subject’s phenomenal consciousness, at any one moment in time, is a single thing. This view has had a major influence on computational theories of consciousness. In particular, what we call single-track theories dominate the literature, theories which contend that our conscious experience is the result of a single consciousness-making process or mechanism in the brain. We argue that the orthodox view is quite wrong: phenomenal experience is not a unity, in the sense of being a single thing at each instant. It is a multiplicity, an aggregate of phenomenal elements, each of which is the product of a distinct consciousness-making mechanism in the brain. Consequently, cognitive science is in need of a multi-track theory of consciousness; a computational model that acknowledges both the manifold nature of experience, and its distributed neural basis

Technocamps: Advancing Computer Science Education in Wales

Computer science education in the UK has undergone substantial scrutiny over the past five years. In particular, from September 2014, we have seen the implementation and delivery of a new computing curriculum in England. However, in Wales -- one of the four devolved nation in the UK -- numerous political, geographical and socio-technical issues have hindered any substantive educational policy or curriculum reform for computer science. This is despite the widespread efforts to address the failings of computer science education in schools since at least 2003 through Technocamps, a pan-Wales university-based schools outreach programme.In this paper we outline the history (and pre-history) of Technocamps, contextualised by the devolved nature of education in the UK, positioning Wales with its specific issues and challenges. Furthermore, we present evidence both in support of this university engagement and intervention model as well as its wider positive effect on promoting and supporting computer science education in Wales, a nation about to take its first steps on the path of a large-scale national curriculum review and significant educational reform

Novel coronavirus mitigation measures implemented by radiotherapy centres in low and middle-income countries: a systematic review

Aim: To identify strategies adopted by radiotherapy centres in low and middle-income countries (LMICs) to mitigate the effects of COVID-19. Background: Studies summarising COVID-19 mitigation strategies designed and implemented by radiotherapy centres in LMICs to avoid delays, deferrments and interruptions of radiotherapy services are lacking. Materials: and Methods: A systematic review was conducted and reported in accordance with the preferred reporting items for systematic review and meta-analysis guideline. Ovid Embase, Ovid MEDLINE and CINAHL were searched for peer-reviewed articles that reported measures adopted by radiotherapy centres in LMICs to reduce the risk of COVID-19. Information on different strategies were extracted from the included studies and textual narrative synthesis was conducted. Results: : Of the 60 articles retrieved, eleven were included. Majority of the studies were conducted in China. Ten of the included studies employed a qualitative design. Four themes were identified: preparing and equipping staff; reinforcing infection prevention and control policies; strengthening coordination and communication; and maintaining physical distancing. Studies reported that radiotherapy centres have: formed COVID-19 response multidisciplinary team; maximised the use of telehealth; adjusted the layout of waiting areas; divided staff into teams; dedicated a room for isolating suspected cases; and adopted triage systems. Conclusions: : Local adaptation of established global strategies coupled with timely development of guidelines, flexibility and innovation have allowed radiotherapy leaders to continue to deliver radiotherapy services to cancer patients in LMICs during the COVID-19 crisis. Robust and quality data collection must be encouraged in LMICs to provide an evidence-based knowledge for use in the event of another pandemic

Subcoronary versus supracoronary aortic stenosis. an experimental evaluation

<p>Abstract</p> <p>Background</p> <p>Valvular aortic stenosis is the most common cause of left ventricular hypertrophy due to gradually increasing pressure work. As the stenosis develop the left ventricular hypertrophy may lead to congestive heart failure, increased risk of perioperative complications and also increased risk of sudden death. A functional porcine model imitating the pathophysiological nature of valvular aortic stenosis is very much sought after in order to study the geometrical and pathophysiological changes of the left ventricle, timing of surgery and also pharmacological therapy in this patient group.</p> <p>Earlier we developed a porcine model for aortic stenosis based on supracoronary aortic banding, this model may not completely imitate the pathophysiological changes that occurs when valvular aortic stenosis is present including the coronary blood flow. It would therefore be desirable to optimize this model according to the localization of the stenosis.</p> <p>Methods</p> <p>In 20 kg pigs subcoronary (n = 8), supracoronary aortic banding (n = 8) or sham operation (n = 4) was preformed via a left lateral thoracotomy. The primary endpoint was left ventricular wall thickness; secondary endpoints were heart/body weight ratio and the systolic/diastolic blood flow ratio in the left anterior descending coronary. Statistical evaluation by oneway anova and unpaired t-test.</p> <p>Results</p> <p>Sub- and supracoronary banding induce an equal degree of left ventricular hypertrophy compared with the control group. The coronary blood flow ratio was slightly but not significantly higher in the supracoronary group (ratio = 0.45) compared with the two other groups (subcoronary ratio = 0.36, control ratio = 0.34).</p> <p>Conclusions</p> <p>A human pathophysiologically compatible porcine model for valvular aortic stenosis was developed by performing subcoronary aortic banding. Sub- and supracoronary aortic banding induce an equal degree of left ventricular hypertrophy. This model may be valid for experimental investigations of aortic valve stenosis but studies of left ventricular hypertrophy can be studied equally well by graduated constriction of the ascending aorta.</p