247 research outputs found
Traffic Light Control Using Deep Policy-Gradient and Value-Function Based Reinforcement Learning
Recent advances in combining deep neural network architectures with
reinforcement learning techniques have shown promising potential results in
solving complex control problems with high dimensional state and action spaces.
Inspired by these successes, in this paper, we build two kinds of reinforcement
learning algorithms: deep policy-gradient and value-function based agents which
can predict the best possible traffic signal for a traffic intersection. At
each time step, these adaptive traffic light control agents receive a snapshot
of the current state of a graphical traffic simulator and produce control
signals. The policy-gradient based agent maps its observation directly to the
control signal, however the value-function based agent first estimates values
for all legal control signals. The agent then selects the optimal control
action with the highest value. Our methods show promising results in a traffic
network simulated in the SUMO traffic simulator, without suffering from
instability issues during the training process
A late glacial and holocene chronology of the Castner Glacier, Delta River Valley, Alaska
New field mapping of surficial deposits near the Castner Glacier, Alaska has identified three distinct moraine complexes beyond the current glacier margin, denoting at least three separate intervals of glacial advance or stillstand. The timing of moraine stabilization and ice retreat was determined by cosmogenic 10Be surface exposure dating for the two older moraines along with lichenometric measurements for all three moraines. Surface exposure ages indicate the timing of ice retreat after the late Wisconsin maximum at 14.7 +/- 0.7 ka (n = 4, k-years before present), and identify the intermediate moraine as corresponding to the Little Ice Age (LIA) at 1627 +/- 32 years AD (n = 2). Lichen measurements from the youngest moraine indicate an age of 1842 AD, corresponding to the late LIA. The lichen data agree to within 50 years of exposure dating results for the older LIA moraine complex, but greatly underestimate the timing of Late Pleistocene ice retreat, indicating a limit of the useful time range for lichen dating using Rhizocarpon (sp.) in this region. There is no evidence for a Younger Dryas re-advance of the Castner Glacier, indicating that the glacial response to this climate fluctuation was less pronounced than that caused by LIA cooling. The increase in elevation of the equilibrium line altitude (ELA) of the Castner Glacier from the late LIA to the present is 120 +/- 20 m. The climate change that could force this rise in ELA is reconstructed to be either a 0.68 to 0.81°C increase in JJA temperature, or a decrease of 8.9 to 12.5 cm H 2O annual accumulation
Impact of Employee Management on Hospitality Innovation Success
The author report on a survey of 185 hospitality manager to examine which employee management practices are associated with success in hospitality innovations. The result suggest that successful new hospitality projects are guided by a strategic human resource management approach, have higher level of training, implement behavior- bared evaluation of their front-line staff and empower their employees
Medicare Reimbursement for Total Joint Arthroplasty: The Driving Forces.
BACKGROUND: Total joint arthroplasty is a large and growing part of the U.S. Medicare budget, drawing attention to how much providers are paid for their services. The purpose of this study was to examine the variables that affect total joint arthroplasty reimbursement. Along with standard economic variables, we include unique health-care variables. Given the focus on value in the Affordable Care Act, the model examines the relationship of the quality of care to total joint arthroplasty reimbursement. We hoped to find that reimbursement patterns reward quality and reflect standard economic principles.
METHODS: Multivariable regression was performed to identify variables that correlate with Medicare reimbursement for total joint arthroplasty. Inpatient charge or reimbursement data on Medicare reimbursements were available for 2,750 hospitals with at least 10 discharges for uncomplicated total joint arthroplasty from the Centers for Medicare & Medicaid Services (CMS) for fiscal year 2011. Reimbursement variability was examined by using the Dartmouth Atlas to group institutions into hospital referral regions and hospital service areas. Independent variables were taken from the Dartmouth Atlas, CMS, the WWAMI (Washington, Wyoming, Alaska, Montana, Idaho) Rural Health Research Center, and the United States Census.
RESULTS: There were 427,207 total joint arthroplasties identified, with a weighted mean reimbursement of 9,103 to $38,686). Nationally, the coefficient of variation for reimbursements was 0.19. The regression model accounted for 52.5% of reimbursement variation among providers. The total joint arthroplasty provider volume (p \u3c 0.001) and patient satisfaction (p \u3c 0.001) were negatively correlated with reimbursement. Government ownership of a hospital (p \u3c 0.001) and higher Medicare costs (p \u3c 0.001) correlated positively with reimbursement.
CONCLUSIONS: Medicare reimbursements for total joint arthroplasty are highly variable. Greater reimbursement was associated with lower patient volume, lower patient satisfaction, a healthier patient population, and government ownership of a hospital. As value-based reimbursement provisions of the Affordable Care Act are implemented, there will be dramatic changes in total joint arthroplasty reimbursements. To meet these changes, providers should expect qualities such as high patient volume, willingness to care for sicker patient populations, patient satisfaction, safe outcomes, and procedural demand to correlate with their reimbursement.
CLINICAL RELEVANCE: Practicing orthopaedic surgeons and hospital administrators should be aware of discrepancies in inpatient reimbursement for total joint arthroplasty from Medicare. Furthermore, these discrepancies are not associated with typical economic factors. These findings warrant further investigation and collaboration between policymakers and providers to develop value-based reimbursement
Enhanced IL-10 production in response to hepatitis C virus proteins by peripheral blood mononuclear cells from human immunodeficiency virus-monoinfected individuals
Background: Multiple immune evasion strategies by which HCV establishes chronic infection have
been proposed, including manipulation of cytokine responses. Prior infection with HIV increases
the likelihood of chronic HCV infection and accelerates development of HCV-related morbidity.
Therefore, we investigated in vitro cytokine responses to HCV structural and non-structural
proteins in peripheral blood mononuclear cells (PBMC) from uninfected, HIV-infected, HCVinfected
and HIV/HCV-coinfected individuals.
Results: Intracellular flow cytometry was used to assess IL-2, IL-10, IL-12, and IFN-γ production
by freshly isolated PBMC incubated for 16 hours with recombinant HCV core, non-structural
protein 3 (NS3), and NS4 proteins. Anti-HCV cellular responses were assessed in HIV/HCVcoinfected
individuals by 3H-thymidine proliferation assay. Exposure to HCV antigens increased IL-
10 production by PBMC, especially in uninfected and HIV-monoinfected individuals. This IL-10
response was attenuated in chronic HCV infection even with HCV/HIV-coinfection. The cells
producing IL-10 in response to HCV proteins in vitro matched a PBMC subset recently shown to
constitutively produce IL-10 in vivo. This subset was found at similar frequencies in uninfected, HIVinfected,
HCV-infected and HIV/HCV-coinfected individuals before exposure to HCV proteins.
HCV-specific T cell proliferation was detectable in only one HIV/HCV-coinfected individual who
demonstrated no HCV-induced IL-10 response.
Conclusion: This pattern suggests that selective induction of IL-10 in uninfected individuals and
especially in HIV-monoinfected individuals plays a role in establishing chronic HCV infection and
conversely, that attenuation of this response, once chronic infection is established, favours
development of hepatic immunopathology
TOWARDS A FORMAT REGISTRY FOR ENGINEERING DATA
ABSTRACT There has been a great deal of interest recently in the problem of long term archiving of digital data. This is especially so in engineering design, where the CAD software tools evolve rapidly but the manufactured products themselves have much longer lifetimes whose support requires archived design data in a usable form. The ISO Open Archival Information Systems (OAIS) Reference Model is a widely used standard for digital archiving, with an essential piece of this model being a file format registry. A file format registry is a system for housing information about file formats that allows for correct interpretation, rendering, storage, and translation of digital files. Currently there exists no file format registry specifically for CAD file formats. This paper explains the purpose of a file format registry for CAD in the greater context of digital archiving, and then presents our approach to creating a CAD file format registry using the Resource Description Framework (RDF) language of the Semantic Web. By creating our file format registry in RDF, we allow archival systems to perform automated reasoning on the stored files. We hope that this paper will increase awareness of this element of engineering design repositories in the research community of this conference
Aluminium‐Catalyzed C(sp)−H Borylation of Alkynes
Historically used in stoichiometric hydroalumination chemistry, recent advances have transformed aluminium hydrides into versatile catalysts for the hydroboration of unsaturated multiple bonds. This catalytic ability is founded on the defining reactivity of aluminium hydrides with alkynes and alkenes: 1,2‐hydroalumination of the unsaturated π‐system. This manuscript reports the aluminium hydride catalyzed dehydroborylation of terminal alkynes. A tethered intramolecular amine ligand controls reactivity at the aluminium hydride centre, switching off hydroalumination and instead enabling selective reactions at the alkyne C−H σ‐bond. Chemoselective C−H borylation was observed across a series of aryl‐ and alkyl‐substituted alkynes (21 examples). On the basis of kinetic and density functional theory studies, a mechanism in which C−H borylation proceeds by σ‐bond metathesis between pinacolborane (HBpin) and alkynyl aluminium intermediates is proposed
Human papillomavirus and post-transplant cutaneous squamous-cell carcinoma:a multicenter, prospective cohort study
Organ transplant recipients (OTRs) have a 100-fold increased risk of cutaneous squamous cell carcinoma (cSCC). We prospectively evaluated the association between β genus human papillomaviruses (βPV) and keratinocyte carcinoma in OTRs. Two OTR cohorts without cSCC were assembled: cohort 1 was transplanted in 2003-2006 (n =\ua0274) and cohort 2 was transplanted in 1986-2002 (n =\ua0352). Participants were followed until death or cessation of follow-up in 2016. βPV infection was assessed in eyebrow hair by using polymerase chain reaction-based methods. βPV IgG seroresponses were determined with multiplex serology. A competing risk model with delayed entry was used to estimate cumulative incidence of histologically proven cSCC and the effect of βPV by using a multivariable Cox regression model. Results are reported as adjusted hazard ratios (HRs). OTRs with 5 or more different βPV types in eyebrow hair had 1.7 times the risk of cSCC vs OTRs with 0 to 4 different types (HR 1.7, 95% confidence interval 1.1-2.6). A similar risk was seen with high βPV loads (HR 1.8, 95% confidence interval 1.2-2.8). No significant associations were seen between serum antibodies and cSCC or between βPV and basal cell carcinoma. The diversity and load of βPV types in eyebrow hair are associated with cSCC risk in OTRs, providing evidence that βPV is associated with cSCC carcinogenesis and may present a target for future preventive strategies
vCJD risk in the Republic of Ireland
BACKGROUND: The Republic of Ireland has the second highest incidence of BSE worldwide. Only a single case of vCJD has been identified to date. METHODS: We estimate the total future number of clinical cases of vCJD using an established mathematical model, and based on infectivity of bovine tissue calculated from UK data and on the relative exposure to BSE contaminated meat. RESULTS: We estimate 1 future clinical case (95% CI 0 – 15) of vCJD in the Republic of Ireland. Irish exposure is from BSE infected indigenous beef products and from imported UK beef products. Additionally, 2.5% of the Irish population was exposed to UK beef through residing in the UK during the 'at-risk' period. The relative proportion of risk attributable to each of these three exposures individually is 2:2:1 respectively. CONCLUSIONS: The low numbers of future vCJD cases estimated in this study is reassuring for the Irish population and for other countries with a similar level of BSE exposure
A clinical practice guideline for the management of patients with acute spinal cord injury: recommendations on the use of methylprednisolone sodium succinate
Introduction: The objective of this guideline is to outline the appropriate use of methylprednisolone sodium succinate (MPSS) in patients with acute spinal cord injury (SCI). Methods: A systematic review of the literature was conducted to address key questions related to the use of MPSS in acute SCI. A multidisciplinary Guideline Development Group used this information, in combination with their clinical expertise, to develop recommendations for the use of MPSS. Based on GRADE (Grading of Recommendation, Assessment, Development and Evaluation), a strong recommendation is worded as "we recommend," whereas a weaker recommendation is indicated by "we suggest." Results: The main conclusions from the systematic review included the following: (1) there were no differences in motor score change at any time point in patients treated with MPSS compared to those not receiving steroids; (2) when MPSS was administered within 8 hours of injury, pooled results at 6- and 12-months indicated modest improvements in mean motor scores in the MPSS group compared with the control group; and (3) there was no statistical difference between treatment groups in the risk of complications. Our recommendations were: (1) "We suggest not offering a 24-hour infusion of high-dose MPSS to adult patients who present after 8 hours with acute SCI"; (2) "We suggest a 24-hour infusion of high-dose MPSS be offered to adult patients within 8 hours of acute SCI as a treatment option"; and (3) "We suggest not offering a 48-hour infusion of high-dose MPSS to adult patients with acute SCI." Conclusions: These guidelines should be implemented into clinical practice to improve outcomes and reduce morbidity in SCI patients
- …