Accelerated particle beams in a 3D simulation of the quiet Sun

Observational and theoretical evidence suggest that beams of accelerated particles are produced in flaring events of all sizes in the solar atmosphere, from X-class flares to nanoflares. Current models of these types of particles in flaring loops assume an isolated 1D atmosphere. A more realistic environment for modelling accelerated particles can be provided by 3D radiative magnetohydrodynamics codes. Here, we present a simple model for particle acceleration and propagation in the context of a 3D simulation of the quiet solar atmosphere, spanning from the convection zone to the corona. We then examine the additional transport of energy introduced by the particle beams. The locations of particle acceleration associated with magnetic reconnection were identified by detecting changes in magnetic topology. At each location, the parameters of the accelerated particle distribution were estimated from local conditions. The particle distributions were then propagated along the magnetic field, and the energy deposition due to Coulomb collisions with the ambient plasma was computed. We find that particle beams originate in extended acceleration regions that are distributed across the corona. Upon reaching the transition region, they converge and produce strands of intense heating that penetrate the chromosphere. Within these strands, beam heating consistently dominates conductive heating below the bottom of the transition region. This indicates that particle beams qualitatively alter the energy transport even outside of active regions.Comment: Accepted for publication in A&

Comparing efficiency of health systems across industrialized countries: a panel analysis.

BackgroundRankings from the World Health Organization (WHO) place the US health care system as one of the least efficient among Organization for Economic Cooperation and Development (OECD) countries. Researchers have questioned this, noting simplistic or inappropriate methodologies, poor measurement choice, and poor control variables. Our objective is to re-visit this question by using newer modeling techniques and a large panel of OECD data.MethodsWe primarily use the OECD Health Data for 25 OECD countries. We compare results from stochastic frontier analysis (SFA) and fixed effects models. We estimate total life expectancy as well as life expectancy at age 60. We explore a combination of control variables reflecting health care resources, health behaviors, and economic and environmental factors.ResultsThe US never ranks higher than fifth out of all 36 models, but is also never the very last ranked country though it was close in several models. The SFA estimation approach produces the most consistent lead country, but the remaining countries did not maintain a steady rank.DiscussionOur study sheds light on the fragility of health system rankings by using a large panel and applying the latest efficiency modeling techniques. The rankings are not robust to different statistical approaches, nor to variable inclusion decisions.ConclusionsFuture international comparisons should employ a range of methodologies to generate a more nuanced portrait of health care system efficiency

Affordable Care Act of 2010: Creating Job Opportunities for Racially and Ethnically Diverse Populations

The health care industry has been an engine of job growth, and the Affordable Care Act of 2010 (ACA) is expected to stimulate further growth. Over the next decade, the health care sector could add 4.6 million jobs, representing a 31% increase from current employment. New job opportunities from entry-level positions to highly trained professions are expected to emerge in the industry.In this report, we present an inventory of health care jobs occupied by people of color, and the changes in occupation mix over time. We then estimate job growth in the health care industry and present potential job opportunities for people of color.

Implementing accelerated particle beams in a 3D simulation of the quiet Sun

Context. The magnetic field in the solar atmosphere continually reconnects and accelerates charged particles to high energies. Simulations of the atmosphere in three dimensions that include the effects of accelerated particles can aid our understanding of the interplay between energetic particle beams and the environment where they emerge and propagate. We presented the first attempt at such a simulation in a previous paper, emphasising the physical model of particle beams. However, the numerical implementation of this model is not straightforward due to the diverse conditions in the atmosphere and the way we must distribute computation between multiple CPU cores. Aims. Here, we describe and verify our numerical implementation of energy transport by electron beams in a 3D magnetohydrodynamics code parallelised by domain decomposition. Methods. We trace beam trajectories using a Runge-Kutta scheme with adaptive step length control and integrate deposited beam energy along the trajectories with a hybrid analytical and numerical approach. To parallelise this, we coordinate beam transport across subdomains owned by separate processes using a buffering system designed to optimise data flow. Results. Using an ad hoc magnetic field with analytical field lines as a test scenario, we show that our parallel implementation of adaptive tracing efficiently follows a challenging trajectory with high precision. By timing executions of electron beam transport with different numbers of processes, we found that the processes communicate with minimal overhead but that the parallel scalability is still sublinear due to workload imbalance caused by the uneven spatial distribution of beams.Comment: Submitted to Astronomy & Astrophysic

Longitudinal Analysis of Electronic Health Records on Staffing Mix in Community Health Centers

Community health centers (CHCs) have long faced clinical staffing challenges especially in rural areas of the US due to providers perceiving a lack of socioeconomic opportunities. A recent study found that CHCs are adaptable and manage to maintain productivity levels across different staffing configurations by leveraging the clinical staff available. What is unknown is how two major changes in the health care landscape—adoption of an electronic health record (EHR) system and recognition of being a patient-centered medical home (PCMH)—have impacted staffing in CHCs, which may in turn have productivity implications

Valuation of Marine Harvest: fundamental analysis of the value of Marine Harvest ASA

This thesis examines the value of Marine Harvest ASA per December 17, 2015. The analysis was performed by using fundamental and relative valuation approaches and the assumptions made in the analysis was made on the basis on throughout analyses of the macro, industry and firm-specific drivers of value in the salmon farming industry. The share price was derived exploring six key factors affecting the cash flows, risk and financial structure of MHG. First, the strategic analysis finds that economic conditions are favorable for the export of Norwegian salmon, but that opportunities for organic growth are limited because of health- and environmental issues and the strictly regulated access to licenses. The industry has consolidated largely and this is likely to be the main driver of growth for MHG. Second, I find that operational margins have been persistently stable, and hence I conclude that historical margins will also be applicable for the forecast period. Third, the salmon prices are expected to increase slightly from the current levels while feed cost is expected to decrease due to MHG’s upstream integrations into feed production. MHG’s harvest volumes are expected to increase in line with historical growth consolidation and limitations of licenses taken into account. Fourth, the income growth from the VAP market is predicted remain strong, much due to the acquisition of Morpol in 2013. Fifth, the cost of capital is expected to remain relatively low as a result of historically low interest rates in the Norwegian economy that is expected to persist. The risk associated with an investment in MHG is moderate, considering MHG’s strong financial position and that the food industry is less volatile than the overall market. Last, the fundamental valuation suggests that the fair share price of MHG is NOK 125, which is also supported by the relative valuation. Hence I conclude that MHG is slightly undervalued at the current trading price, and a buy recommendation is appropriate.nhhma