Neutrino transport in accretion disks

We test approximate approaches to solving a neutrino transport problem that presents itself in the analysis of some accretion-disk models. Approximation #1 consists of replacing the full, angular- dependent, distribution function by a two-stream simulation, where the streams are respectively outwardly and inwardly directed, with angles $\cos \theta=\pm 1/\sqrt{3}$ to the vertical. In this approximation the full energy dependence of the distribution function is retained, as are the energy and temperature dependences of the scattering rates. Approximation #2, used in recent works on the subject, replaces the distribution function by an intensity function and the scattering rates by temperature-energy-averaged quantities. We compare the approximations to the results of solving the full Boltzmann equation. Under some interesting conditions, approximation #1 passes the test; approximation #2 does not. We utilize the results of our analysis to construct a toy model of a disc at a temperature and density such that relativistic particles are more abundant than nucleons, and dominate both the opacity and pressure. The nucleons will still provide most of the energy density. In the toy model we take the rate of heat generation (which drives the radiative transfer problem) to be proportional to the nucleon density. The model allows the simultaneous solution of the neutrino transport and hydrostatic equilibrium problems in a disk in which the nucleon density decreases approximately linearly as one moves from the median plane of the disk upwards, reaching zero on the upper boundary.Comment: 8 pages, 5 figures Parentheses added in eqs. 10-1

Primacy of effective communication and its influence on adherence to artemether-lumefantrine treatment for children under five years of age: a qualitative study.

BACKGROUND\ud \ud Prompt access to artemesinin-combination therapy (ACT) is not adequate unless the drug is taken according to treatment guidelines. Adherence to the treatment schedule is important to preserve efficacy of the drug. Although some community based studies have reported fairly high levels of adherence, data on factors influencing adherence to artemether-lumefantrine (AL) treatment schedule remain inadequate. This study was carried-out to explore the provider's instructions to caretakers, caretakers' understanding of the instructions and how that understanding was likely to influence their practice with regard to adhering to AL treatment schedule.\ud \ud METHODS\ud \ud A qualitative study was conducted in five villages in Kilosa district, Tanzania. In-depth interviews were held with providers that included prescribers and dispensers; and caretakers whose children had just received AL treatment. Information was collected on providers' instructions to caretakers regarding dose timing and how to administer AL; and caretakers' understanding of providers' instructions.\ud \ud RESULTS\ud \ud Mismatch was found on providers' instructions as regards to dose timing. Some providers' (dogmatists) instructions were based on strict hourly schedule (conventional) which was likely to lead to administering some doses in awkward hours and completing treatment several hours before the scheduled time. Other providers (pragmatists) based their instruction on the existing circumstances (contextual) which was likely to lead to delays in administering the initial dose with serious treatment outcomes. Findings suggest that, the national treatment guidelines do not provide explicit information on how to address the various scenarios found in the field. A communication gap was also noted in which some important instructions on how to administer the doses were sometimes not provided or were given with false reasons.\ud \ud CONCLUSIONS\ud \ud There is need for a review of the national malaria treatment guidelines to address local context. In the review, emphasis should be put on on-the-job training to address practical problems faced by providers in the course of their work. Further research is needed to determine the implication of completing AL treatment prior to scheduled time

Corrosione sotto sforzo su conserve di tonno sott’olio in banda stagnata

Nel presente lavoro sono stati analizzati alcuni casi di corrosione sotto sforzo (Stress Corrosion Cracking, SCC)su scatolette metalliche in banda stagnata per la conserva di tonno sott’olio. I contenitori metalliciprovenivano da due diversi fabbricanti di barattoli, con carni di diversi operatori del settore alimentare.In entrambi i casi sono state osservate microcricche fini e ramificate da SCC a ridosso delle regioni disaldatura. Dalle analisi chimiche del liquido associato ai prodotti sono state rilevate quantità sensibili di faseacquosa ed elevate concentrazioni di fosfati e cloruri, assieme a concentrazioni minori di bicarbonati e solfati.Gli esami in microscopia elettronica in scansione (SEM/EDS) hanno evidenziato all’interno delle lesionila presenza di prodotti di corrosione dell’acciaio frammisti a quantità sensibili soprattutto di fosfati.Tra i fattori scatenanti l’innesco della SCC hanno sicuramente importanza la separazione di fase acquosae le autotensioni in regione di saldatura. Occorre però anche una specificità dell’accoppiamento metalloambientee, in tal senso, l’ipotesi più probabile è l’abbondante presenza di fosfati in un ambiente acquosopraticamente deaerato. Da quanto osservato, questi anioni sembrano indurre anche inversione di polaritàtra acciaio al carbonio e deposito di stagno. Nel lavoro sono infine dati suggerimenti per minimizzarel’insorgenza di tali danneggiamenti

Metallic materials compatibility in E22 and M15 motor fuel blends

Factors influencing the potential corrosiveness of E22 and M15 motor fuels were studied using immersionand electrochemical corrosion tests. The latter were carried out using fuels at 18 °C and 50 °Cwith and without additions of water contaminants (inorganic acids, chloride ions, and salts).The corrosion behaviour of carbon steels (St 52, 100Cr6), stainless steels (AISI 304, AISI 440 C)and aluminium alloys (AlMg3, 6056 aluminium alloy) was evaluated.AISI 304 was fully compatible either in as-received or modified fuels in all experimental conditionshere imposed. AISI 440 C steel was able to develop a homogeneous passive film when was exposed at 18 °C,but a loss of corrosion resistance was detected when the temperature raised to 50 °C. Aluminium alloyswere the poorest performers in these fuels, exhibiting significant damaging under the form of surface pitting.Carbon steels exhibited reasonable resistances only in E22 and M15 fuels at 18 °C

Graphene-based photovoltaic cells for near-field thermal energy conversion

Thermophotovoltaic devices are energy-conversion systems generating an electric current from the thermal photons radiated by a hot body. In far field, the efficiency of these systems is limited by the thermodynamic Schockley-Queisser limit corresponding to the case where the source is a black body. On the other hand, in near field, the heat flux which can be transferred to a photovoltaic cell can be several orders of magnitude larger because of the contribution of evanescent photons. This is particularly true when the source supports surface polaritons. Unfortunately, in the infrared where these systems operate, the mismatch between the surface-mode frequency and the semiconductor gap reduces drastically the potential of this technology. Here we show that graphene-based hybrid photovoltaic cells can significantly enhance the generated power paving the way to a promising technology for an intensive production of electricity from waste heat.Comment: 5 pages, 4 figure

Adherence to yoga and exercise interventions in a 6-month clinical trial

<p>Abstract</p> <p>Background</p> <p>To determine factors that predict adherence to a mind-body intervention in a randomized trial.</p> <p>Design</p> <p>We analyzed adherence data from a 3-arm trial involving 135 generally healthy seniors 65–85 years of age randomized to a 6-month intervention consisting of: an Iyengar yoga class with home practice, an exercise class with home practice, or a wait-list control group. Outcome measures included cognitive function, mood, fatigue, anxiety, health-related quality of life, and physical measures. Adherence to the intervention was obtained by class attendance and biweekly home practice logs.</p> <p>Results</p> <p>The drop-out rate was 13%. Among the completers of the two active interventions, average yoga class attendance was 77% and home practice occurred 64% of all days. Average exercise class attendance was 69% and home exercise occurred 54% of all days. There were no clear effects of adherence on the significant study outcomes (quality of life and physical measures). Class attendance was significantly correlated with baseline measures of depression, fatigue, and physical components of health-related quality of life. Significant differences in baseline measures were also found between study completers and drop-outs in the active interventions. Adherence was not related to age, gender, or education level.</p> <p>Conclusion</p> <p>Healthy seniors have good attendance at classes with a physically active intervention. Home practice takes place over half of the time. Decreased adherence to a potentially beneficial intervention has the potential to decrease the effect of the intervention in a clinical trial because subjects who might sustain the greatest benefit will receive a lower dose of the intervention and subjects with higher adherence rates may be functioning closer to maximum ability before the intervention. Strategies to maximize adherence among subjects at greater risk for low adherence will be important for future trials, especially complementary treatments requiring greater effort than simple pill-taking.</p

The Right Place at the Right Time: Creative Spaces in Libraries

Purpose This essay explores the recent trend in libraries: that of the establishment of spaces specifically set aside for creative work. The rise of these dedicated creative spaces is owed to a confluence of factors that happen to be finding their expression together in recent years. This essay examines the history of these spaces and explores the factors that gave rise to them and will fuel them moving forward. Design/Methodology/Approach A viewpoint piece, this essay combines historical research and historical/comparative analyses to examine the ways by which libraries have supported creative work in the past and how they may continue to do so into the 21st century. Findings The key threads brought together include a societal recognition of the value of creativity and related skills and attributes; the philosophies, values, and missions of libraries in both their longstanding forms and in recent evolutions; the rise of participatory culture as a result of inexpensive technologies; improved means to build community and share results of efforts; and library experience and historical practice in matters related to creativity. The chapter concludes with advice for those interested in the establishment of such spaces, grounding those reflections in the author’s experiences in developing a new creative space at Virginia Commonwealth University. Originality/value While a number of pieces have been written that discuss the practicalities of developing certain kinds of creative spaces, very little has been written that situates these spaces in larger social and library professional contexts; this essay begins to fill that gap

Cognitive and behavioral predictors of light therapy use

Objective: Although light therapy is effective in the treatment of seasonal affective disorder (SAD) and other mood disorders, only 53-79% of individuals with SAD meet remission criteria after light therapy. Perhaps more importantly, only 12-41% of individuals with SAD continue to use the treatment even after a previous winter of successful treatment. Method: Participants completed surveys regarding (1) social, cognitive, and behavioral variables used to evaluate treatment adherence for other health-related issues, expectations and credibility of light therapy, (2) a depression symptoms scale, and (3) self-reported light therapy use. Results: Individuals age 18 or older responded (n = 40), all reporting having been diagnosed with a mood disorder for which light therapy is indicated. Social support and self-efficacy scores were predictive of light therapy use (p's<.05). Conclusion: The findings suggest that testing social support and self-efficacy in a diagnosed patient population may identify factors related to the decision to use light therapy. Treatments that impact social support and self-efficacy may improve treatment response to light therapy in SAD. © 2012 Roecklein et al

Cost of poor adherence to anti-hypertensive therapy in five European countries

The financial burden for EU health systems associated with cardiovascular disease (CV) has been estimated to be nearly €110 billion in 2006, corresponding to 10 % of total healthcare expenditure across EU or a mean €223 annual cost per capita. The main purpose of this study is to estimate the costs related to hypertension and the economic impact of increasing adherence to anti-hypertensive therapy in five European countries (Italy, Germany, France, Spain and England). A probabilistic prevalence-based decision tree model was developed to estimate the direct costs of CV related to hypertension (CV defined as: stroke, heart attack, heart failure) in five European countries. Our model considered adherence to hypertension treatment as a main driver of blood pressure (BP) control (BP < 140/90 mmHg). Relative risk of CV, based on controlled or uncontrolled BP group, was estimated from the Framingham Heart Study and national review data. Prevalence and cost data were estimated from national literature reviews. A national payer (NP) perspective for 10 years was considered. Probabilistic sensitivity analysis was performed in order to evaluate uncertainty around the results (given as 95 % confidence intervals). The model estimated a total of 8.6 million (1.4 in Italy, 3.3 in Germany, 1.2 in Spain, 1.8 in France and 0.9 in England) CV events related to hypertension over the 10-year time horizon. Increasing the adherence rate to anti-hypertensive therapy to 70 % (baseline value is different for each country) would lead to 82,235 fewer CV events (24,058 in Italy, 7,870 in Germany, 18,870 in Spain, 24,855 in France and 6,553 in England). From the NP perspective, the direct cost associated with hypertension was estimated to be €51.3 billion (8.1 in Italy, 17.1 in Germany, 12.2 in Spain, 8.8 in France and 5.0 in England). Increasing adherence to anti-hypertensive therapy to 70 % would save a total of €332 million (CI 95 %: €319-346 million) from the NPs perspective. This study is the first attempt to estimate the economic impact of non-adherence amongst patients with diagnosed hypertension in Europe, using data from five European countries (Italy, France, Germany, Spain and England). © 2014 Springer-Verlag Berlin Heidelberg