227 research outputs found

    Improved SOT (Hinode mission) high resolution solar imaging observations

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    We consider the best today available observations of the Sun free of turbulent Earth atmospheric effects, taken with the Solar Optical Telescope (SOT) onboard the Hinode spacecraft. Both the instrumental smearing and the observed stray light are analyzed in order to improve the resolution. The Point Spread Function (PSF) corresponding to the blue continuum Broadband Filter Imager (BFI) near 450 nm is deduced by analyzing i/ the limb of the Sun and ii/ images taken during the transit of the planet Venus in 2012. A combination of Gaussian and Lorentzian functions is selected to construct a PSF in order to remove both smearing due to the instrumental diffraction effects (PSF core) and the large-angle stray light due to the spiders and central obscuration (wings of the PSF) that are responsible for the parasitic stray light. A Max-likelihood deconvolution procedure based on an optimum number of iterations is discussed. It is applied to several solar field images, including the granulation near the limb. The normal non-magnetic granulation is compared to the abnormal granulation which we call magnetic. A new feature appearing for the first time at the extreme- limb of the disk (the last 100 km) is discussed in the context of the definition of the solar edge and of the solar diameter. A single sunspot is considered in order to illustrate how effectively the restoration works on the sunspot core. A set of 125 consecutive deconvolved images is assembled in a 45 min long movie illustrating the complexity of the dynamical behavior inside and around the sunspot.Comment: 15 pages, 22 figures, 1 movi

    Medicaid Enrollment among Prison Inmates in a Non-expansion State: Exploring Predisposing, Enabling, and Need Factors Related to Enrollment Pre-incarceration and Post-Release

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    Prison inmates suffer from a heavy burden of physical and mental health problems and have considerable need for healthcare and coverage after prison release. The Affordable Care Act may have increased Medicaid access for some of those who need coverage in Medicaid expansion states, but inmates in non-expansion states still have high need for Medicaid coverage and face unique barriers to enrollment. We sought to explore barriers and facilitators to Medicaid enrollment among prison inmates in a non-expansion state. We conducted qualitative interviews with 20 recently hospitalized male prison inmates who had been approached by a prison social worker due to probable Medicaid eligibility, as determined by the inmates’ financial status, health, and past Medicaid enrollment. Interviews were transcribed verbatim and analyzed using a codebook with both thematic and interpretive codes. Coded interview text was then analyzed to identify predisposing, enabling, and need factors related to participants’ Medicaid enrollment prior to prison and intentions to enroll after release. Study participants’ median age, years incarcerated at the time of the interview, and projected remaining sentence length were 50, 4, and 2 years, respectively. Participants were categorized into three sub-groups based on their self-reported experience with Medicaid_ (1) those who never applied for Medicaid before prison (n = 6); (2) those who unsuccessfully attempted to enroll in Medicaid before prison (n = 3); and (3) those who enrolled in Medicaid before prison (n = 11). The six participants who had never applied to Medicaid before their incarceration did not hold strong attitudes about Medicaid and mostly had little need for Medicaid due to being generally healthy or having coverage available from other sources such as the Veteran’s Administration. However, one inmate who had never applied for Medicaid struggled considerably to access mental healthcare due to lapses in employer-based health coverage and attributed his incarceration to this unmet need for treatment. Three inmates with high medical need had their Medicaid applications rejected at least once pre-incarceration, resulting in periods without health coverage that led to worsening health and financial hardship for two of them. Eleven inmates with high medical need enrolled in Medicaid without difficulty prior to their incarceration, largely due to enabling factors in the form of assistance with the application by their local Department of Social Services or Social Security Administration, their mothers, medical providers, or prison personnel during a prior incarceration. Nearly all inmates acknowledged that they would need health coverage after release from prison, and more than half reported that they would need to enroll in Medicaid to gain healthcare coverage following their release. Although more population-based assessments are necessary, our findings suggest that greater assistance with Medicaid enrollment may be a key factor so that people in the criminal justice system who qualify for Medicaid—and other social safety net programs—may gain their rightful access to these benefits. Such access may benefit not only the individuals themselves but also the communities to which they return

    General boundary conditions for the envelope function in multiband k.p model

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    We have derived general boundary conditions (BC) for the multiband envelope functions (which do not contain spurious solutions) in semiconductor heterostructures with abrupt heterointerfaces. These BC require the conservation of the probability flux density normal to the interface and guarantee that the multiband Hamiltonian be self--adjoint. The BC are energy independent and are characteristic properties of the interface. Calculations have been performed of the effect of the general BC on the electron energy levels in a potential well with infinite potential barriers using a coupled two band model. The connection with other approaches to determining BC for the envelope function and to the spurious solution problem in the multiband k.p model are discussed.Comment: 15 pages, 2 figures; to be published in Phys. Rev. B 65, March 15 issue 200

    New insights into the genetic etiology of Alzheimer's disease and related dementias

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    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
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