PENCIL: Towards a Platform-Neutral Compute Intermediate Language for DSLs

We motivate the design and implementation of a platform-neutral compute intermediate language (PENCIL) for productive and performance-portable accelerator programming

Personal digital assistants to collect tuberculosis bacteriology data in Peru reduce delays, errors, and workload, and are acceptable to users: cluster randomized controlled trial

SummaryObjectivesTo evaluate the effectiveness of a personal digital assistant (PDA)-based system for collecting tuberculosis test results and to compare this new system to the previous paper-based system. The PDA- and paper-based systems were evaluated based on processing times, frequency of errors, and number of work-hours expended by data collectors.MethodsWe conducted a cluster randomized controlled trial in 93 health establishments in Peru. Baseline data were collected for 19 months. Districts (n=4) were then randomly assigned to intervention (PDA) or control (paper) groups, and further data were collected for 6 months. Comparisons were made between intervention and control districts and within-districts before and after the introduction of the intervention.ResultsThe PDA-based system had a significant effect on processing times (p<0.001) and errors (p=0.005). In the between-districts comparison, the median processing time for cultures was reduced from 23 to 8 days and for smears was reduced from 25 to 12 days. In that comparison, the proportion of cultures with delays >90 days was reduced from 9.2% to 0.1% and the number of errors was decreased by 57.1%. The intervention reduced the work-hours necessary to process results by 70% and was preferred by all users.ConclusionsA well-designed PDA-based system to collect data from institutions over a large, resource-poor area can significantly reduce delays, errors, and person-hours spent processing data

Red and dead: The progenitor of SN 2012aw in M95

Core-collapse supernovae (SNe) are the spectacular finale to massive stellar evolution. In this Letter, we identify a progenitor for the nearby core-collapse SN 2012aw in both ground based near-infrared, and space based optical pre-explosion imaging. The SN itself appears to be a normal Type II Plateau event, reaching a bolometric luminosity of 10$^{42}$ erg s$^{-1}$ and photospheric velocities of $\sim$11,000 \kms\ from the position of the H$\beta$ P-Cygni minimum in the early SN spectra. We use an adaptive optics image to show that the SN is coincident to within 27 mas with a faint, red source in pre-explosion HST+WFPC2, VLT+ISAAC and NTT+SOFI images. The source has magnitudes $F555W$=26.70$\pm$0.06, $F814W$=23.39$\pm$0.02, $J$=21.1$\pm$0.2, $K$=19.1$\pm$0.4, which when compared to a grid of stellar models best matches a red supergiant. Interestingly, the spectral energy distribution of the progenitor also implies an extinction of $A_V>$1.2 mag, whereas the SN itself does not appear to be significantly extinguished. We interpret this as evidence for the destruction of dust in the SN explosion. The progenitor candidate has a luminosity between 5.0 and 5.6 log L/\lsun, corresponding to a ZAMS mass between 14 and 26 \msun\ (depending on $A_V$), which would make this one of the most massive progenitors found for a core-collapse SN to date.Comment: Submitted to ApJ Letter

Period-Magnitude relation of Mira-like variables in the Large Magellanic Cloud as a tool to understand circumstellar extinction

Near- to mid-infrared period-magnitude relations and also the period-bolometric luminosity relation of OGLE-III Mira-like variables in the LMC are derived. The relations have a kink, and the period at which the break occurs is quantitatively obtained. There are many Mira-like variables whose fluxes at the optical and the near-infrared wavebands are fainter than the ones predicted by the period-magnitude relations. The deviation is due to the circumstellar extinction, and the amount of the deviation is found to be strongly correlated with near-infrared colors. The empirical formulae relating the amount of the deviation and the near-infrared colors are derived. These relations are useful to accurately calculate the distances to the dusty Mira-like variables, because the dimmed fluxes due to the circumstellar extinction can be estimated. In a manner analogous to the interstellar extinction law, the ratios of deviations at any two different wavebands are calculated. The ratios are found to change with the pulsation period, indicating that the dust properties are subject to change as Mira-like variables evolve.Comment: 8 pages, 5 figures and 4 tables, accepted for publication in MNRA

Looking For Disoriented Chiral Condensates From Pion Distributions

We suggest two methods for the detection of the formation of disoriented chiral condensates in heavy ion collisions. We show that the variance in the number of charged pions (in a suitable range of momentum space) provides a signature for the observation of a disoriented chiral condensate. The signal should be observable even if multiple domains of D$\chi$C form provided the average number of pions per domain is significantly larger than unity. The variance of the number charged pions alone provides a signal which can be used even if the number of neutral pions cannot be measured in a given detector. On the other hand, the probability distribution in $R$, the proportion of neutral pions to all pions emitted in heavy ion collisions in certain kinematic regions, has been suggested as a signal of a disoriented chiral condensate. Here we note that the signature can be greatly enhanced by making suitable cuts in the data. In particular, we consider reducing the data set such that the $k$ pions with lowest $p_T$ are all neutral. We find that, given such cuts, can be substantially different from 1/3. For example, for a single D$\chi$C domain without contamination due to incoherently emitted pions, is 3/5 given the pion with lowest $p_T$ is neutral, and 5/7 given the two pions with lowest $p_T$ are both neutral, {\it etc.}. The effects of multi-domain D$\chi$C formation and noise due to incoherent pion emission can be systematically incorporated. Potential applications to experiments and their limitations are briefly discussed.Comment: 16 pages in REVTeX, 7 figures. Combined and updated version of nucl-th/9903029 and nucl-th/9904074. Accepted by Phys. Rev.

Fundamentals of aerosol therapy in critical care

Drug dosing in critically ill patients is challenging due to the altered drug pharmacokinetics-pharmacodynamics associated with systemic therapies. For many drug therapies, there is potential to use the respiratory system as an alternative route for drug delivery. Aerosol drug delivery can provide many advantages over conventional therapy. Given that respiratory diseases are the commonest causes of critical illness, use of aerosol therapy to provide high local drug concentrations with minimal systemic side effects makes this route an attractive option. To date, limited evidence has restricted its wider application. The efficacy of aerosol drug therapy depends on drug-related factors (particle size, molecular weight), device factors, patient-related factors (airway anatomy, inhalation patterns) and mechanical ventilation-related factors (humidification, airway). This review identifies the relevant factors which require attention for optimization of aerosol drug delivery that can achieve better drug concentrations at the target sites and potentially improve clinical outcome

What We Know about the Public’s Level of Concern for Farm Animal Welfare in Food Production in Developed Countries

Population growth and rising consumption of meat, dairy, eggs and fish are forcing the world to face the intersecting challenges of how to sustainably feed a population expected to exceed 9 billion by 2050, while also controlling the impact of food production on the planet, on people and on animals. This review acknowledges the absence of a globally accepted definition of animal welfare and then explores the literature regarding different levels of concern for animal welfare in food production by such stakeholders as veterinarians, farmers, and the general public. It focuses on the evidence that the general public’s level of concern for animal welfare is linked to various demographic and personal characteristics, such as age, gender, religion, location, meat eating, and knowledge of animal welfare. Certain animals have characteristics that influence concern for their welfare, with those species that are considered more intelligent being afforded more concern. There is compelling evidence that the general public’s understanding of animal welfare in food production is poor. Acknowledging that public concern can be a driving force to change current production methods, the authors suggest widespread consciousness raising to redefine socially acceptable methods of food production from animals and to ensure that it remains in step with societal concerns

Non-localities in nucleon-nucleus potentials

Two causes of non-locality inherent in nucleon-nucleus scattering are considered. They are the results of two-nucleon antisymmetry of the projectile with each nucleon in the nucleus and the dynamic polarization potential representation of channel coupling. For energies $\sim 40 - 300$ MeV, a g-folding model of the optical potential is used to show the influence of the knock-out process that is a result of the two-nucleon antisymmetry. To explore the dynamic polarization potential caused by channel coupling, a multichannel algebraic scattering model has been used for low-energy scattering.Comment: 12 pages, 11 figures, submitted to EPJ

Electric Polarizability of the Nucleon in the Nambu--Jona-Lasinio Model

The electric polarizability of the nucleon is calculated in the soliton approach to the Nambu--Jona-Lasinio model. We analyze the leading-$N_c$ contributions, as well as the effects of rotational $1/N_c$ corrections and $\Delta$-$N$ mass splitting. Our model prediction is substantially reduced compared to other soliton calculations, and is closer to the experimental value.Comment: 16 pages, RevTeX, 3 figures (included, PS, uuencoded), RUB-TPII-55/93 and TPR-93-3

HIV treatment as prevention among people who inject drugs – a re-evaluation of the evidence

Background: Population-level associations between community measures of HIV viral load and HIV incidence have been interpreted as evidence for HIV anti-retroviral treatment (ART) as prevention among people who inject drugs (PWID). However, investigation of concurrent HCV and HIV incidence trends allows examination of alternative explanations for the fall in HIV incidence. We estimate the contribution of ART and reductions in injecting risk for reducing HIV incidence in Vancouver between 1996 and 2007. Methods: A deterministic model of HIV and HCV transmission among PWID was calibrated to the baseline (1996) HIV and HCV epidemic among PWID in Vancouver. While incorporating parameter uncertainty, the model projected what levels of ART protection and decreases in injecting risk could reproduce the observed reduction in HIV and HCV incidence for 1996–2007, and so what impact would have been achieved with just ART or just reductions in injecting risk. Results: Model predictions suggest the estimated reduction (84%) in HCV incidence for 1996–2007 required a 59% (2.5–97.5 percentile range 49–76%) reduction in injecting risk, which accounted for nine-tenths of the observed decrease in HIV incidence; the remainder was achieved with a moderate ART efficacy for reducing sexual HIV infectivity (70%, 51–89%) and an uncertain ART efficacy for reducing injection-related HIV infectivity (44%, 0–96%). Despite this uncertainty, projections suggest that the decrease in injecting risk reduced HIV incidence by 76% (63–85%) and ART further reduced HIV incidence by 8% (2–19%), or on its own by 3% (−34–37%). Conclusions: Observed declines in HIV incidence in Vancouver between 1996 and 2007 should be seen as a success for intensive harm reduction, whereas ART probably played a small role