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

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

Measurement of forward neutral pion transverse momentum spectra for s\sqrt{s} = 7TeV proton-proton collisions at LHC

The inclusive production rate of neutral pions in the rapidity range greater than $y=8.9$ has been measured by the Large Hadron Collider forward (LHCf) experiment during LHC $\sqrt{s}=7$\,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

Measurement of zero degree single photon energy spectra for sqrt(s) = 7TeV proton-proton collisions at LHC

In early 2010, the Large Hadron Collider forward (LHCf) experiment measured very forward neutral particle spectra in LHC proton-proton collisions. From a limited data set taken under the best beam conditions (low beam-gas background and low occurance of pile-up events), the single photon spectra at sqrt(s)=7TeV and pseudo-rapidity (eta) ranges from 8.81 to 8.99 and from 10.94 to infinity were obtained for the first time and are reported in this paper. The spectra from two independent LHCf detectors are consistent with one another and serve as a cross check of the data. The photon spectra are also compared with the predictions of several hadron interaction models that are used extensively for modeling ultra high energy cosmic ray showers. Despite conservative estimates for the systematic errors, none of the models agree perfectly with the measurements. A notable difference is found between the data and the DPMJET 3.04 and PYTHIA 8.145 hadron interaction models above 2TeV where the models predict higher photon yield than the data. The QGSJET II-03 model predicts overall lower photon yield than the data, especially above 2TeV in the rapidity range 8.81<eta<8.99