8,035 research outputs found
Comparative energetic assessment of methanol production from COâ: chemical versus electrochemical process
Emerging emission-to-liquid (eTL) technologies that produce liquid fuels from COâ are a possible solution for both the global issues of greenhouse gas emissions and fossil fuel depletion. Among those technologies, COâ hydrogenation and high-temperature COâ electrolysis are two promising options suitable for large-scale applications. In this study, two COâ -to-methanol conversion processes, i.e., production of methanol by COâ hydrogenation and production of methanol based on high-temperature COâ electrolysis, are simulated using Aspen HYSYS. With Aspen Energy Analyzer, heat exchanger networks are optimized and minimal energy requirements are determined for the two different processes. The two processes are compared in terms of energy requirement and climate impact. It is found that the methanol production based on COâ electrolysis has an energy efficiency of 41%, almost double that of the COâ hydrogenation process provided that the required hydrogen is sourced from water electrolysis. The hydrogenation process produces more COâ when fossil fuel energy sources are used, but can result in more negative COâ emissions with renewable energies. The study reveals that both of the eTL processes can outperform the conventional fossil-fuel-based methanol production process in climate impacts as long as the renewable energy sources are implemented
An estimate of the cost of burnout on early retirement and reduction in clinical hours of practicing physicians in Canada.
BackgroundInterest in the impact of burnout on physicians has been growing because of the possible burden this may have on health care systems. The objective of this study is to estimate the cost of burnout on early retirement and reduction in clinical hours of practicing physicians in Canada.MethodsUsing an economic model, the costs related to early retirement and reduction in clinical hours of physicians were compared for those who were experiencing burnout against a scenario in which they did not experience burnout. The January 2012 Canadian Medical Association Masterfile was used to determine the number of practicing physicians. Transition probabilities were estimated using 2007-2008 Canadian Physician Health Survey and 2007 National Physician Survey data. Adjustments were also applied to outcome estimates based on ratio of actual to planned retirement and reduction in clinical hours.ResultsThe total cost of burnout for all physicians practicing in Canada is estimated to be 185.2 million due to early retirement and $27.9 million due to reduced clinical hours). Family physicians accounted for 58.8% of the burnout costs, followed by surgeons for 24.6% and other specialists for 16.6%.ConclusionThe cost of burnout associated with early retirement and reduction in clinical hours is substantial and a significant proportion of practicing physicians experience symptoms of burnout. As health systems struggle with human resource shortages and expanding waiting times, this estimate sheds light on the extent to which the burden could be potentially decreased through prevention and promotion activities to address burnout among physicians
Local anaesthetic bupivacaine induced ovarian and prostate cancer apoptotic cell death and underlying mechanisms in vitro
Retrospective studies indicate that the use of regional anesthesia can reduce cancer recurrence after surgery which could be due to ranging from immune function preservation to direct molecular mechanisms. This study was to investigate the effects of bupivacaine on ovarian and prostate cancer cell biology and the underlying molecular mechanisms. Cell viability, proliferation and migration of ovarian carcinoma (SKOV-3) and prostate carcinoma (PC-3) were examined following treatment with bupivacaine. Cleaved caspase 3, 8 and 9, and GSK-3β, pGSK-3β(tyr216) and pGSK-3β(ser9) expression were assessed by immunofluorescence. FAS ligand neutralization, caspase and GSK-3 inhibitors and GSK-3β siRNA were applied to further explore underlying mechanisms. Clinically relevant concentrations of bupivacaine reduced cell viability and inhibited cellular proliferation and migration in both cell lines. Caspase 8 and 9 inhibition generated partial cell death reversal in SKOV-3, whilst only caspase 9 was effective in PC-3. Bupivacaine increased the phosphorylation of GSK-3β(Tyr216) in SKOV-3 but without measurable effect in PC3. GSK-3β inhibition and siRNA gene knockdown decreased bupivacaine induced cell death in SKOV-3 but not in PC3. Our data suggests that bupivacaine has direct âanti-cancerâ properties through the activation of intrinsic and extrinsic apoptotic pathways in ovarian cancer but only the intrinsic pathway in prostate cancer
Model Counting for Formulas of Bounded Clique-Width
We show that #SAT is polynomial-time tractable for classes of CNF formulas
whose incidence graphs have bounded symmetric clique-width (or bounded
clique-width, or bounded rank-width). This result strictly generalizes
polynomial-time tractability results for classes of formulas with signed
incidence graphs of bounded clique-width and classes of formulas with incidence
graphs of bounded modular treewidth, which were the most general results of
this kind known so far.Comment: Extended version of a paper published at ISAAC 201
Le Community Enterprises in Gran Bretagna: imprese sociali come modello di rigenerazione
Nel dibattito italiano, sia accademico che giornalistico, le questioni che riguardano la riduzione della spesa pubblica, la dismissione del patrimonio pubblico, la rigenerazione urbana delle periferie, la partecipazione ed il coinvolgimento delle comunitĂ nei processi di pianificazione, rappresentano temi di crescente rilevanza.
In risposta a queste problematiche, la Gran Bretagna - paese in cui da sempre la pianificazione del territorio ha una dimensione multidisciplinare - ha riconosciuto il ruolo di alcune imprese sociali definite community enterprises. Queste organizzazioni sono nate da processi spontanei e distinti, in uno stretto dualismo tra lâazione locale e gli indirizzi delle politiche nazionali, affermandosi come strumento di rigenerazione urbana sostenibile. Lâefficacia dâazione delle community enterprises consiste nella promozione di processi di capacity bulding, che pongono al centro della rigenerazione le comunitĂ con le proprie risorse, favorendone lâattitudine ad operare per il proprio welfare e proponendo formule redistributive di sviluppo urbano. La recente trasformazione culturale e politica nota come âfrom the Big State to Big Societyâ ha riconosciuto la capacitĂ dâazione di queste imprese, ma ne ha allo stesso tempo messo in discussione il ruolo, individuando come maggior limite delle stesse la dipendenza dal sostegno pubblico quale elemento necessario a garantirne lo sviluppo e la loro azione sui territori.
In questo contributo1 si propone una lettura dellâevoluzione delle politiche urbane del Regno Unito e un inquadramento generale delle diverse tipologie di community enterprises, con particolare riferimento ai Community Development Trust. Nello specifico è stato approfondito il caso del Westway Development Trust di Londra, il suo potenziale di sviluppo e i risultati raggiunti in termini di attivitĂ e capacitĂ economiche
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