Artificial broadening of the high-energy end of electron spectrum in supernova remnants

The observed spectrum of a supernova remnant (SNR) is a superposition of many ``local'' spectra emitted by regions of SNRs that are under different physical conditions. The question remains as to whether the broadening of the high-energy end of the observed nonthermal spectrum of SNRs, like in G347.3-0.5 and SN 1006, can be an artifact of observations or it is a consequence of the microphysics involved in the acceleration process. In this note we study the influence of parameters variations (inside the volume and over the surface of SNR) on the shape of the high-energy end of the synchrotron (and also inverse Compton) spectrum. We consider three possibilities for these parameter variations: i) gradients downstream of the shock with constant maximum energy of the accelerated electrons and the potential variation in time of the injection efficiency, ii) then we add the possibility of the maximum energy depending on time, and finally iii) the possible obliquity dependences of maximum energy and injection efficiency. It is shown that gradients of density and magnetic field strength downstream of the shock are ineffective in modifying the shape of the synchrotron spectrum, even if an SNR evolves in the nonuniform interstellar medium and/or the injection efficiency varies in time. The time dependence of the maximum energy of the electrons accelerated by the shock is also not able to make the observed spectrum much broader. The only possibility of producing considerable broadening in the spectrum is the variation in the maximum energy of electrons over the surface of SNR. In such a case, the obliquity dependence of the injection efficiency also affects the shape of the spectrum, but its role is less significant.Comment: 6 pages, 4 figures, A&A accepte

Splanchnic metabolism of nutrients and hormones in steers fed alfalfa under conditions of increased absorption of ammonia and L-arginine supply across the portal-drained viscera

Effects of increased ammonia and/or arginine absorption on net splanchnic (portal-drained viscera [PDV] plus liver) metabolism of nonnitrogenous nutrients and hormones in cattle were examined. Six Hereford × Angus steers (501 ± 1 kg BW) prepared with vascular catheters for measurements of net flux across the splanchnic bed were fed a 75% alfalfa:25% (as-fed basis) corn and soybean meal diet (0.523 MJ of ME/[kg BW0.75.d]) every 2 h without (27.0 g of N/kg of DM) and with 20 g of urea/kg of DM (35.7 g of N/kg of DM) in a split-plot design. Net flux measurements were made immediately before and after a 72-h mesenteric vein infusion of L-arginine (15 mmol/h). There were no treatment effects onPDVor hepaticO2 consumption. Dietary urea had no effect on splanchnic metabolism of glucose or L-lactate, but arginine infusion decreased net hepatic removal of L-lactate when urea was fed (P < 0.01). Net PDV appearance of n-butyrate was increased by arginine infusion (P < 0.07), and both dietary urea (P < 0.09) and arginine infusion (P < 0.05) increased net hepatic removal of n-butyrate. Dietary urea also increased total splanchnic acetate output (P < 0.06), tended to increase arterial glucagon concentration (P < 0.11), and decreased arterial ST concentration (P < 0.03). Arginine infusion increased arterial concentration (P < 0.07) and net PDV release (P < 0.10) and tended to increase hepatic removal (P < 0.11) of insulin, as well as arterial concentration (P < 0.01) and total splanchnic output (P < 0.01) of glucagon. Despite changes in splanchnic N metabolism, increased ammonia and arginine absorption had little measurable effect on splanchnic metabolism of glucose and other nonnitrogenous components of splanchnic energy metabolism

Sustainable Gastronomy: the Environmental Impacts of How We Cook Now and How the “Sustainable Diets” Agenda Might Shape How We Cook in the Future?

The 2019 Eat-Lancet report has proposed a global healthy sustainable diet, which would provide not only for human health but also sustain a healthy planet. The main recommendations are to increase consumption of healthy foods (such as vegetables, fruits, whole grains, legumes, and nuts), and a decrease in consumption of unhealthy foods (such as red meat, sugar, and refined grains). A critique of the EAT-Lancet diet is that it lacks consideration of local and traditional diets, food ways or systems of production, and the report has limited suggestions for how a global healthy sustainable diet could be implemented (Edman et al., 2019; Jonas, 2019; Torjesen, 2019). This paper firstly explores the sustainability impacts of cooking food, and how different foods have different environmental impacts from production, consumption, and cooking. It reports on a 2019 survey of cooking methods and habits in the UK, Australia and USA, examining how these different nations’ unique culinary and cooking habits lead to different environmental impacts. This paper then examines what dietary shifts are being recommended by current academic literature, and how these dietary shifts may change the methods of cooking in the future

Towards reframing professional expert support

The paper addresses practical ways of reconfiguring professional expertise in development practice in moving away from the expert as a technocrat. Two projects associated with managing natural resource dilemmas suggest an alternative way of framing intervention involving professional experts providing a more appropriate collaborative learning space for development practice. The paper describes the heuristic devices generated by each project as helpful in bringing out dialectic tensions between practice and understanding, and between systems of interest and situations of interest (or situated problems). Firstly, SLIM (social learning for the integrated management and sustainable use of water at catchment scale) - a European Framework Programme 5 project - exemplifies social learning as a measure of sustainable development. The heuristic illustrates the dependence of sustainability on changes in practice and understanding amongst professionals and other stakeholders as part of concerted - rather than merely individual or even collective - action. Secondly, ECOSENSUS (Electronic/Ecological Collaborative Sensemaking Support System) - a Guyana focused intervention involving several UK universities in collaboration with the University of Guyana and Amerindian community representatives from the North Rupununi wetlands - builds on the SLIM heuristic in supporting the development of practice. Additionally, the ECOSENSUS heuristic provides conceptual space for the interaction between conceptual constructs of distributed stakeholders (that is, systems thinking) including those with professional expertise, and the actual context of intervention (the situated problem). Both SLIM and ECOSENSUS provide heuristics for process-orientated management enabling more meaningful and purposeful interaction between professional/ technical experts and other stakeholders, as an alternative to conventional project-orientated management intervention. An alternative framing may help to steer practice away from the apoliticised comforting linearity of professionalised systematic project management towards more constructive systemic endeavours involving multiple stakeholders

A Faster Tableau for CTL*

There have been several recent suggestions for tableau systems for deciding satisfiability in the practically important branching time temporal logic known as CTL*. In this paper we present a streamlined and more traditional tableau approach built upon the author's earlier theoretical work. Soundness and completeness results are proved. A prototype implementation demonstrates the significantly improved performance of the new approach on a range of test formulas. We also see that it compares favourably to state of the art, game and automata based decision procedures.Comment: In Proceedings GandALF 2013, arXiv:1307.416

The ecology of phytoplankton in Shropshire and Cheshire meres

This review summarizes the findings of 5 years' research (June 1970-June 1975) on the meres of the Shropshire-Cheshire Plain. A mere is a small, shallow lake; supplied principally by ground water, whose chemical composition is infkuenced by the glacial frift through which it is percolating. The seasonal periodicity of the phytoplankton in the meres involved work mainly in the Grose Mere. Here diatoms were typically dominant in Feb & March, green algae in April & May, blue-green algae in early summer and dinoflagellates in late summer. This pattern is broadly similar from year to year, and has been suggested to be representative of a 'regional type'; it is also similar to that described for many of the world's mildly eutrophic temperate lakes. Vertical distribution of phytoplankton is influenced by their buoyancy (or lack of it) of by their ability to swim. A stylized depth-time distribution of 4 major phytoplankton components in Crose Mere is given diagrammatically

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Philosophy with children : helping designers cooperate with children

Engaging children in design through in-depth interviews is coming to prominence in the IDC community, which increasingly engages with issues about understanding the children's world. To date, research in this area has primarily focused on engaging children using techniques somehow similar to adult-techniques (moodboards, brainstorming, laddering,...). However, questioning or interviewing children is fraught with difficulties. The proposed workshop seeks to explore where and how a philosophy with children methodology can be adapted for design, exploring themes such as Socratic Attitudes, wondering, and question types. This workshop aims to build an interdisciplinary community of researchers, designers, and practitioners to share and discuss their work and experiences

Equity-focused developmental evaluation using critical systems thinking

Developmental evaluation questions the ethical basis of an intervention in terms of whether it’s ‘doing the right thing’ rather than merely ‘doing things right’. But developmental evaluation invites a space for exploring not only ethical but also political issues associated particularly with equity-focused evaluations. Drawing on ideas from critical systems thinking (CST) and critical systems heuristics, an evaluation framework with a pro-equity focus is suggested. The framework addresses issues of complex interrelationships, invites theory of change associated with philosophical ethics, and provides a means of surfacing, and potentially transforming, debilitating relations of power in a complex evaluand. A case study of the long-standing Narmada project in India is used to illustrate the workings of proposed framework. The paper describes how the underpinning methodological ideas of CST incorporating triple-loop learning can enhance the practice of developmental evaluation