1,380 research outputs found
Probabilistic micromechanics and macromechanics of polymer matrix composites
A probabilistic evaluation of an eight ply graphite-epoxy quasi-isotropic laminate was completed using the Integrated Composite Analyzer (ICAN) in conjunction with Monte Carlo simulation and Fast Probability Integration (FPI) techniques. Probabilistic input included fiber and matrix properties, fiber misalignment, fiber volume ratio, void volume ratio, ply thickness and ply layup angle. Cumulative distribution functions (CDFs) for select laminate properties are given. To reduce the number of simulations, a Fast Probability Integration (FPI) technique was used to generate CDFs for the select properties in the absence of fiber misalignment. These CDFs were compared to a second Monte Carlo simulation done without fiber misalignment effects. It was found that FPI requires fewer simulations to obtain the cumulative distribution functions as opposed to Monte Carlo simulation techniques. Furthermore, FPI provides valuable information regarding the sensitivities of composite properties to the constituent properties, fiber volume ratio and void volume ratio
Bosonic behavior of entangled fermions
Two bound, entangled fermions form a composite boson, which can be treated as
an elementary boson as long as the Pauli principle does not affect the behavior
of many such composite bosons. The departure of ideal bosonic behavior is
quantified by the normalization ratio of multi-composite-boson states. We
derive the two-fermion-states that extremize the normalization ratio for a
fixed single-fermion purity P, and establish general tight bounds for this
indicator. For very small purities, P<1/N^2, the upper and lower bounds
converge, which allows to quantify accurately the departure from perfectly
bosonic behavior, for any state of many composite bosons.Comment: 9 pages, 5 figures, accepted by PR
Georgia’s Rural Hospital Closures: The Common-Good Approach to Ethical Decision-Making
Background: Critical access hospitals provide several essential services to local communities. Along with the functions associated with providing necessary medical care, they also offer employment opportunities and other economic benefits to the communities they serve. Since 2010, the number of rural hospitals closures has steadily increased. The common-good approach to ethical decision-making provides a framework that aids in evaluation of the effects that hospital closures have on rural residents and communities.
Methods: This analysis includes results of a systematic overview of peer-reviewed literature to address the following research questions: 1) How have state policies and the adoption of Medicaid expansion influenced the viability or rural hospitals? 2) What are the ethical implications of Medicaid expansion and state policy reform/adoption pertaining to viability of rural hospitals? and 3) What are the ethical implications of critical access hospitals closures on rural communities in Georgia? Information related to these questions is presented, along with tactics to addressing these in an ethical manner.
Results: This descriptive analysis shows that the largest number of state-specific closures have occurred in states with a federal exchange and which chose not to expand Medicaid. Characteristics of the state of Georgia and the counties with recent closures show that these counties typically have smaller populations with a high minority presence, lower education and income levels, and higher numbers of medically uninsured.
Conclusions: The common-good approach to ethical decision-making is suitable for evaluating the ethical implications of policy-level decisions impacting the closure of critical access hospitals serving the rural communities of Georgia
Georgia’s Rural Hospital Closures: The Common-Good Approach to Ethical Decision-Making
Background: Critical access hospitals provide several essential services to local communities. Along with the functions associated with providing necessary medical care, they also offer employment opportunities and other economic benefits to the communities they serve. Since 2010, the number of rural hospitals closures has steadily increased. The common-good approach to ethical decision-making provides a framework that aids in evaluation of the effects that hospital closures have on rural residents and communities.
Methods: This analysis includes results of a systematic overview of peer-reviewed literature to address the following research questions: 1) How have state policies and the adoption of Medicaid expansion influenced the viability or rural hospitals? 2) What are the ethical implications of Medicaid expansion and state policy reform/adoption pertaining to viability of rural hospitals? and 3) What are the ethical implications of critical access hospitals closures on rural communities in Georgia? Information related to these questions is presented, along with tactics to addressing these in an ethical manner.
Results: This descriptive analysis shows that the largest number of state-specific closures have occurred in states with a federal exchange and which chose not to expand Medicaid. Characteristics of the state of Georgia and the counties with recent closures show that these counties typically have smaller populations with a high minority presence, lower education and income levels, and higher numbers of medically uninsured.
Conclusions: The common-good approach to ethical decision-making is suitable for evaluating the ethical implications of policy-level decisions impacting the closure of critical access hospitals serving the rural communities of Georgia
Short wheat challenge is a reproducible in-vivo assay to detect immune response to gluten.
It has been reported that interferon (IFN)-γ-secreting T cells reactive to gluten can be detected in the peripheral blood of individuals with treated coeliac disease (CD) after a short consumption of wheat-containing food. By contrast, very little is known about the reproducibility of this in-vivo procedure in the same patient cohort which underwent two, or more, gluten consumptions. Fourteen coeliac patients in remission consumed wheat bread for 3 days; 13 underwent a second gluten challenge after a wash-out of 3-10 months on a strict gluten-free diet. Immune reactivity to gluten was analysed in peripheral blood by detecting IFN-γ before and 6 days after commencing a gluten diet. Gliadin-specific IFN-γ-secreting CD4(+) T cells increased significantly on day 6 of the first challenge. These cells resulted as prevalently human leucocyte antigen (HLA)-DQ restricted and with a phenotype of gut homing, as suggested by the expression of β7-integrin. Similarly, reactiveness to gliadin was observed after the second wheat consumption, although with an individual variability of responses at each challenge. Our findings confirmed that the short wheat challenge is a non-invasive approach to investigate the gluten-related immune response in peripheral blood of subjects intolerant to gluten. Furthermore, we demonstrated that the in-vivo procedure can be reproduced in the same subject cohort after a gluten wash-out of at least 3 months. Our study has important implications for the application of this procedure to clinical practice
Second order analysis of geometric functionals of Boolean models
This paper presents asymptotic covariance formulae and central limit theorems
for geometric functionals, including volume, surface area, and all Minkowski
functionals and translation invariant Minkowski tensors as prominent examples,
of stationary Boolean models. Special focus is put on the anisotropic case. In
the (anisotropic) example of aligned rectangles, we provide explicit analytic
formulae and compare them with simulation results. We discuss which information
about the grain distribution second moments add to the mean values.Comment: Chapter of the forthcoming book "Tensor Valuations and their
Applications in Stochastic Geometry and Imaging" in Lecture Notes in
Mathematics edited by Markus Kiderlen and Eva B. Vedel Jensen. (The second
version mainly resolves minor LaTeX problems.
Measurement of forward neutral pion transverse momentum spectra for = 7TeV proton-proton collisions at LHC
The inclusive production rate of neutral pions in the rapidity range greater
than has been measured by the Large Hadron Collider forward (LHCf)
experiment during LHC \,TeV proton-proton collision operation in
early 2010. This paper presents the transverse momentum spectra of the neutral
pions. The spectra from two independent LHCf detectors are consistent with each
other and serve as a cross check of the data. The transverse momentum spectra
are also compared with the predictions of several hadronic interaction models
that are often used for high energy particle physics and for modeling
ultra-high-energy cosmic-ray showers.Comment: 18 Pages, 10 figures, submitted to Phys. Rev.
Georgia\u27s Critical Access Hospitals: Financial Performance and Process Improvement
Background: Georgia’s Critical Access Hospitals (CAH) are in crisis. Within the last 2 years, four CAHs have closed their doors due to failed financial and operational performance. Evidence points to the risk that several more are on the brink of closure. CAH closures have far-reaching impact on residents. Negative impacts include the extra distance that patients must travel to seek care, the displacement of health professionals and the unravelling of the entire fabric of the communities these hospitals serve. We hope to help participants understand the financial and operational challenges of CAHs, and to identify realistic strategies to enhance the resilience of these hospitals.
Methods: The Georgia Southern team worked with a cohort of CAHs across the state of Georgia to identify financial and operational best practices. Year 1 of this project focused on data collection, analysis and benchmarking. Year 2 is currently focused on performance improvement through Lean Six Sigma.
Results: CAHs face financial constraints due to factors such as low volume, declining market share, unfavorable payer mix, challenges relating to collections, and difficulties in recruiting providers. CAHs in Georgia performed more poorly on the financial indicators assessed, in comparison to respective national medians. Many CAHs in our cohort are better organized to deal with crises – utilizing strong executive and bureaucratic structures – than to pursue ongoing improvement through employee empowerment and a process focus.
Conclusions: Improvements in the operational and financial management practices of Georgia’s CAHs may significantly improve performance. Evidence-based strategies for operational and financial improvement are vital to sustainability. Opportunities exist for collaboration between public health systems and rural hospitals, including CAHs in assuring healthcare access for rural populations
Operational and Financial Performance of Georgia\u27s Critical Access Hospitals
Background: Georgia’s Critical Access Hospitals (CAHs) face increasingly complex threats to financial sustainability, as demonstrated by the disproportionally high number of closures in comparison to other states in the nation.
Methods: Financial performance measures (including profitability, revenue, liquidity, debt, utilization, and productivity), site visits, key personnel interviews, and a revenue cycle management assessment were used to assess the strategic landscape of CAHs in Georgia, analyze financial and operational performance, and provide recommendations.
Results: For CAHs in Georgia, financial and operating performance indicators, interviews, and assessments depict a challenging operating environment, but opportunities for improvement exist through implementation of a Lean Six Sigma program and improved benchmarking processes.
Conclusions: Georgia’s CAHs operate in a challenging environment, but operational improvement strategies (such as a Lean Six Sigma program) and benchmarking directed towards business processes, including revenue cycle management, provide opportunities for sustainability in the future.
Key words: Critical Access Hospital, financial performance, Process Improvement, LEAN Six Sigma, rural hospita
Structural basis of control of inward rectifier Kir2 channel gating by bulk anionic phospholipids
Inward rectifier potassium (Kir) channel activity is controlled by plasma membrane lipids. Phosphatidylinositol-4,5-bisphosphate (PIP(2)) binding to a primary site is required for opening of classic inward rectifier Kir2.1 and Kir2.2 channels, but interaction of bulk anionic phospholipid (PL(−)) with a distinct second site is required for high PIP(2) sensitivity. Here we show that introduction of a lipid-partitioning tryptophan at the second site (K62W) generates high PIP(2) sensitivity, even in the absence of PL(−). Furthermore, high-resolution x-ray crystal structures of Kir2.2[K62W], with or without added PIP(2) (2.8- and 2.0-Å resolution, respectively), reveal tight tethering of the C-terminal domain (CTD) to the transmembrane domain (TMD) in each condition. Our results suggest a refined model for phospholipid gating in which PL(−) binding at the second site pulls the CTD toward the membrane, inducing the formation of the high-affinity primary PIP(2) site and explaining the positive allostery between PL(−) binding and PIP(2) sensitivity
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