660 research outputs found

    Ab-initio study of BaTiO3 surfaces

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    We have carried out first-principles total-energy calculations of (001) surfaces of the tetragonal and cubic phases of BaTiO3. Both BaO-terminated (type I) and TiO2-terminated (type II) surfaces are considered, and the atomic configurations have been fully relaxed. We found no deep-gap surface states for any of the surfaces, in agreement with previous theoretical studies. However, the gap is reduced for the type-II surface, especially in the cubic phase. The surface relaxation energies are found to be substantial, i.e., many times larger than the bulk ferroelectric well depth. Nevertheless, the influence of the surface upon the ferroelectric order parameter is modest; we find only a small enhancement of the ferroelectricity near the surface.Comment: 8 pages, two-column style with 4 postscript figures embedded. Uses REVTEX and epsf macros. Also available at http://www.physics.rutgers.edu/~dhv/preprints/index.html#pad_sur

    NGO Legitimacy: Four Models

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    The aim of this paper is to examine NGOs’ legitimacy in the context of global politics. In order to yield a better understanding of NGOs’ legitimacy at the international level it is important to examine how their legitimacy claims are evaluated. This paper proposes dividing the literature into four models based on the theoretical and analytical approaches to their legitimacy claims: the market model, social change model, new institutionalism model and the critical model. The legitimacy criteria generated by the models are significantly different in their analytical scope of how one is to assess the role of NGOs operating as political actors contributing to democracy. The paper argues that the models present incomplete, and sometimes conflicting, views of NGOs’ legitimacy and that this poses a legitimacy dilemma for those assessing the political agency of NGOs in world politics. The paper concludes that only by approaching their legitimacy holistically can the democratic role of NGOs be explored and analysed in the context of world politics

    Implementing a Prison Medicaid Enrollment Program for Inmates with a Community Inpatient Hospitalization

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    In 2011, North Carolina (NC) created a program to facilitate Medicaid enrollment for state prisoners experiencing community inpatient hospitalization during their incarceration. The program, which has been described as a model for prison systems nationwide, has saved the NC prison system approximately $10 million annually in hospitalization costs and has potential to increase prisoners’ access to Medicaid benefits as they return to their communities. This study aims to describe the history of NC’s Prison-Based Medicaid Enrollment Assistance Program (PBMEAP), its structure and processes, and program personnel’s perspectives on the challenges and facilitators of program implementation. We conducted semi-structured interviews and a focus group with PBMEAP personnel including two administrative leaders, two “Medicaid Facilitators,” and ten social workers. Seven major findings emerged: 1) state legislation was required to bring the program into existence; 2) the legislation was prompted by projected cost savings; 3) program development required close collaboration between the prison system and state Medicaid office; 4) technology and data sharing played key roles in identifying inmates who previously qualified for Medicaid and would likely qualify if hospitalized; 5) a small number of new staff were sufficient to make the program scalable; 6) inmates generally cooperated in filling out Medicaid applications, and their cooperation was encouraged when social workers explained possible benefits of receiving Medicaid after release; and 7) the most prominent program challenges centered around interaction with county Departments of Social Services, which were responsible for processing applications. Our findings could be instructive to both Medicaid non-expansion and expansion states that have either implemented similar programs or are considering implementing prison Medicaid enrollment programs in the future

    Contrasted histories of organelle and nuclear genomes underlying physiological diversification in a grass species

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    C4 photosynthesis evolved multiple times independently in angiosperms, but most origins are relatively old so that the early events linked to photosynthetic diversification are blurred. The grass Alloteropsis semialata is an exception, as this species encompasses C4 and non-C4 populations. Using phylogenomics and population genomics, we infer the history of dispersal and secondary gene flow before, during and after photosynthetic divergence in A. semialata. We further analyse the genome composition of individuals with varied ploidy levels to establish the origins of polyploids in this species. Detailed organelle phylogenies indicate limited seed dispersal within the mountainous region of origin and the emergence of a C4 lineage after dispersal to warmer areas of lower elevation. Nuclear genome analyses highlight repeated secondary gene flow. In particular, the nuclear genome associated with the C4 phenotype was swept into a distantly related maternal lineage probably via unidirectional pollen flow. Multiple intraspecific allopolyploidy events mediated additional secondary genetic exchanges between photosynthetic types. Overall, our results show that limited dispersal and isolation allowed lineage divergence, with photosynthetic innovation happening after migration to new environments, and pollen-mediated gene flow led to the rapid spread of the derived C4 physiology away from its region of origin

    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

    Slogging and Stumbling Toward Social Justice in a Private Elementary School: The Complicated Case of St. Malachy

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    This case study examines St. Malachy, an urban Catholic elementary school primarily serving children traditionally marginalized by race, class, linguistic heritage, and disability. As a private school, St. Malachy serves the public good by recruiting and retaining such traditionally marginalized students. As empirical studies involving Catholic schools frequently juxtapose them with public schools, the author presents this examination from a different tack. Neither vilifying nor glorifying Catholic schooling, this study critically examines the pursuit of social justice in this school context. Data gathered through a 1-year study show that formal and informal leaders in St. Malachy adapted their governance, aggressively sought community resources, and focused their professional development to build the capacity to serve their increasingly pluralistic student population. The analysis confirms the deepening realization that striving toward social justice is a messy, contradictory, and complicated pursuit, and that schools in both public and private sectors are allies in this pursuit

    Low dispersal and ploidy differences in a grass maintain photosynthetic diversity despite gene flow and habitat overlap

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    Geographical isolation facilitates the emergence of distinct phenotypes within a single species, but reproductive barriers or selection is needed to maintain the polymorphism after secondary contact. Here, we explore the processes that maintain intraspecific variation of C4 photosynthesis, a complex trait that results from the combined action of multiple genes. The grass Alloteropsis semialata includes C4 and non‐C4 populations, which have co‐existed as a polyploid series for more than one million years in the miombo woodlands of Africa. Using population genomics, we show that there is genome‐wide divergence for the photosynthetic types, but the current distribution does not reflect a simple habitat displacement scenario as the genetic clusters overlap, being occasionally mixed within a given habitat. Despite evidence of recurrent introgression between non‐C4 and C4, in both diploids and polyploids, the distinct genetic lineages retain their identity, potentially because of selection against hybrids. Coupled with strong isolation by distance within each genetic group, this selection created a geographical mosaic of photosynthetic types. Diploid C4 and non‐C4 types never grew together, and the C4 type from mixed populations constantly belonged to the hexaploid lineage. By limiting reproductive interactions between photosynthetic types, the ploidy difference likely allows their co‐occurrence, reinforcing the functional diversity within this species. Together, these factors enabled the persistence of divergent physiological traits of ecological importance within a single species despite gene flow and habitat overlap

    Establishment and dynamics of the balsam fir seedling bank in old forests of northeastern Quebec

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    This study examines balsam fir (Abies balsamea (L.) Mill.) recruitment in old fir stands. Studying the regeneration of these stands is essential to understand the regeneration dynamic of the species in the absence of standdestroying disturbances. The objectives were (1) to obtain substrate-seedling associations for different age-classes and according to the presence or absence of adventitious roots; (2) to evaluate the contribution of the seed rain to seedling recruitment; (3) to re-examine age structures using the most appropriate method that minimizes estimation errors due to the presence of adventitious roots. A total of 90 quadrats (1 m2) were established along transects. In each quadrat, subtrates were characterized (type and topography) and their area was estimated. All balsam fir seedlings (<50 cm tall) present in the quadrats were located, harvested whole (root and shoot), and described (age, height, presence of adventitious roots, etc). Fir seedlings were strongly associated with woody mounds covered with thin mats of mixed mosses and Pleurozium shreberi (Bird.) Mitt. but negatively associated with flat topography particularly dominated by Hylocomium splendens (Hedw.) B.S.G. The presence of adventitious root is related to seedling age more than substrate type or topography. The age structure is in agreement with seed production and disturbance regime
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