558 research outputs found
Significance of the VELACS Project to the Solution of Boundary Value Problems in Geotechnical Engineering
The VELACS project was conducted in order to improve existing methods for the analysis of the consequences of soil liquefaction. The project showed that centrifuge studies are repeatable only under carefully controlled conditions. Most procedures were able to predict the onset of liquefaction in contractive soils, but only effective stress based fully coupled nonlinear procedures were able to predict deformations due to liquefaction· None of the currently available procedures could simulate the behavior of dilative soils adequately. Problems were attributed to improper constitutive model implementation and inadequate calibration. An example to evaluate the behavior of a flow slide observed in a dynamic centrifuge test is presented. Numerical simulations of deformations with a finite deformation formulation showed that the main core of the embankment remained stable after shaking. This is in agreement with the observed behavior
Symptom Domain Groups of the Patient-Reported Outcomes Measurement Information System Tools Independently Predict Hospitalizations and Re-hospitalizations in Cirrhosis
Background Patient-Reported Outcomes Measurement Information System (PROMIS) tools can identify health-related quality of life (HRQOL) domains that could differentially affect disease progression. Cirrhotics are highly prone to hospitalizations and re-hospitalizations, but the current clinical prognostic models may be insufficient, and thus studying the contribution of individual HRQOL domains could improve prognostication. Aim Analyze the impact of individual HRQOL PROMIS domains in predicting time to all non-elective hospitalizations and re-hospitalizations in cirrhosis. Methods Outpatient cirrhotics were administered PROMIS computerized tools. The first non-elective hospitalization and subsequent re-hospitalizations after enrollment were recorded. Individual PROMIS domains significantly contributing toward these outcomes were generated using principal component analysis. Factor analysis revealed three major PROMIS domain groups: daily function (fatigue, physical function, social roles/activities and sleep issues), mood (anxiety, anger, and depression), and pain (pain behavior/impact) accounted for 77% of the variability. Cox proportional hazards regression modeling was used for these groups to evaluate time to first hospitalization and re-hospitalization. Results A total of 286 patients [57 years, MELD 13, 67% men, 40% hepatic encephalopathy (HE)] were enrolled. Patients were followed at 6-month (mth) intervals for a median of 38 mths (IQR 22â47), during which 31% were hospitalized [median IQR mths 12.5 (3â27)] and 12% were re-hospitalized [10.5 mths (3â28)]. Time to first hospitalization was predicted by HE, HR 1.5 (CI 1.01â2.5, p = 0.04) and daily function PROMIS group HR 1.4 (CI 1.1â1.8, p = 0.01), independently. In contrast, the pain PROMIS group were predictive of the time to re-hospitalization HR 1.6 (CI 1.1â2.3, p = 0.03) as was HE, HR 2.1 (CI 1.1â4.3, p = 0.03). Conclusions Daily function and pain HRQOL domain groups using PROMIS tools independently predict hospitalizations and re-hospitalizations in cirrhotic patients
Surveillance transbronchial lung biopsies: Implication for survival after lung transplantation
AbstractObjectives: We wished to determine whether early rejection after lung transplantation as assessed by surveillance transbronchial biopsy predicts for survival. Methods: Between 1990 and 1997, 96 consecutive patients had lung transplantation: 89 had a minimum 1-month follow-up. For 71 consecutive patients we have 1-year follow-up and for 69 patients we have the results of the first 3 biopsies. Cytomegalovirus status, bronchiolitis obliterans prevalence, and use of total lymphoid irradiation are noted. Biopsies were done at 1 week and 1, 3, and 6 months. Standard immunosuppression consisted of induction antilymphocyte globulin and high-dose methylprednisolone induction for 1 week and standard maintenance triple therapy. Acute rejection treatment was with pulse methylprednisolone. Bronchiolitis obliterans syndrome was treated with total lymphoid irradiation and a change to tacrolimus and mycophenolate. Blinded grading using International Society for Heart and Lung Transplantation classification was done retrospectively. Results: Survival at 1 month and 1, 2, and 3 years for the 96-patient cohort with 1-year follow-up was 93%, 74%, 62%, and 56%. Survival was not significantly different for subsets with rejection on any combination of the first 3 biopsies (1/3, 2/3, 3/3) or absence of rejection on the first 3 biopsies. Ninety-one positive biopsy results were graded. Eighteen of 71 patients had one or more moderate or severe rejection episodes without survival difference relative to the others. There was no statistically significant association between acute rejection on the first 3 surveillance biopsy results and bronchiolitis obliterans. Conclusions: Intensive induction and maintenance immunotherapy with surveillance transbronchial biopsies and aggressive treatment of acute rejection is associated with a survival similar to that of patients without early acute rejection. This regimen appears to uncouple the association between early acute rejection and bronchiolitis obliterans. Further study may elucidate this mechanism. (J Thorac Cardiovasc Surg 2000;119:27-38
The University of Akron Human Powered Vehicle Team
The University of Akron Human Powered Vehicle Teamâs 2016 vehicle, Klokan, was designed, manufactured and tested with safety, reliability, performance and ease of use in mind. The vehicle is a fully faired tadpole trike with a lightweight aluminum frame constructed from 6061-T6 tubing having a total weight of 8.9 lbs. To complement the lightweight frame, the fairing is constructed from polycarbonate, PETG and carbon fiber strips which combine into a lightweight, easy to manufacture weather barrier and aerodynamic structure. Klokan was designed to be a safe and efficient mode of everyday transportation which ensures that riders are sufficiently protected by a rollover protection system (RPS) which was designed to meet the ASME HPVC requirements with a minimum safety factor of two.
The project scope includes all aspects of design and fabrication to create a vehicle that is easy to manufacture, easy to use, safe, and low cost to facilitate its usability in everyday situations. The team completed research on how to improve the manufacturability, reliability, and performance through analysis of designs, computer based modeling, and physical testing to validate that the bike meets team goals as well as exceeding the requirements set by the ASME Human Powered Vehicle Competition.
The frame was designed in a manner that reduces welding through the use of bends and allows for precision fixturing to be manufactured and used to construct multiple frames quickly and efficiently. The fairingâs modular construction reduces the need for specialized tooling while minimizing weight and construction time. The team designed and successfully implemented an innovative rollover warning system which actively monitors the percentage of vehicle load on each tire and warns the driver through audible tone and visual warning light prior to a dangerous rollover becoming imminent
Geography, institutions and development: a review ofthe long-run impacts of climate change
The links between climate change, economic growth and economic development have gained increasing attention over recent years in both the academic and policy literature. However, most of the existing literature has tended to focus on direct, short run effects of climate change on the economy, for example due to extreme weather events and changes in agricultural growing conditions. In this paper we review potential effects of climate change on the prospects for long-run economic development. These effects might operate directly, via the role of geography (including climate) as a fundamental determinant of relative prosperity, or indirectly by modifying the environmental context in which political and economic institutions evolve. We consider potential mechanisms from climate change to long-run economic development that have been relatively neglected to date, including, for instance, effects on the distribution of income and political power. We conclude with some suggestions for areas of future research
A roadmap for gene system development in Clostridium
Clostridium species are both heroes and villains. Some cause serious human and animal diseases, those present in the microbiota contribute to health and wellbeing, while others represent useful industrial chassis for the production of chemicals and fuels. To understand, counter or exploit, there is a fundamental requirement for effective systems that may be used for directed or random genome modifications. We have formulated a simple roadmap whereby the necessary gene systems maybe developed and deployed. At its heart is the use of 'pseudo-suicide' vectors and the creation of a pyrE mutant (a uracil auxotroph), initially aided by ClosTron technology, but ultimately made using a special form of allelic exchange termed ACE (Allele-Coupled Exchange). All mutants, regardless of the mutagen employed, are made in this host. This is because through the use of ACE vectors, mutants can be rapidly complemented concomitant with correction of the pyrE allele and restoration of uracil prototrophy. This avoids the phenotypic effects frequently observed with high copy number plasmids and dispenses with the need to add antibiotic to ensure plasmid retention. Once available, the pyrE host may be used to stably insert all manner of application specific modules. Examples include, a sigma factor to allow deployment of a mariner transposon, hydrolases involved in biomass deconstruction and therapeutic genes in cancer delivery vehicles. To date, provided DNA transfer is obtained, we have not encountered any clostridial species where this technology cannot be applied. These include, Clostridium difficile, Clostridium acetobutylicum, Clostridium beijerinckii, Clostridium botulinum, Clostridium perfringens, Clostridium sporogenes, Clostridium pasteurianum, Clostridium ljungdahlii, Clostridium autoethanogenum and even Geobacillus thermoglucosidasius
The impact of financial incentives on the implementation of asthma or diabetes self-management: A systematic review
Introduction: Financial incentives are utilised in healthcare systems in a number of countries to improve quality of care delivered to patients by rewarding practices or practitioners for achieving set targets.
Objectives: To systematically review the evidence investigating the impact of financial incentives for implementation of supported self-management on quality of care including: organisational process outcomes, individual behavioural outcomes, and health outcomes for individuals with asthma or diabetes; both conditions with an extensive evidence base for self-management.
Methods: We followed Cochrane methodology, using a PICOS search strategy to search eight databases in November 2015 (updated May 2017) including a broad range of implementation methodologies. Studies were weighted by robustness of methodology, number of participants and the quality score. We used narrative synthesis due to heterogeneity of studies.
Results: We identified 2,541 articles; 12 met our inclusion criteria. The articles were from the US (n = 7), UK (n = 4) and Canada (n = 1). Measured outcomes were HbA1c tests undertaken and/or the level achieved (n = 10), written action plans for asthma (n = 1) and hospital/emergency department visits (n = 1). Three of the studies were part of a larger incentive scheme including many conditions; one focused on asthma; eight focussed on diabetes. In asthma, the proportion receiving âperfect careâ (including providing a written action plan) increased from 4% to 88% in one study, and there were fewer hospitalisations/emergency department visits in another study. Across the diabetes studies, quality-of-care/GP performance scores improved in three, were unchanged in six and deteriorated in one.
Conclusions: Results for the impact of financial incentives for the implementation of self-management were mixed. The evidence in diabetes suggests no consistent impact on diabetic control. There was evidence from a single study of improved process and health outcomes in asthma. Further research is needed to confirm these findings and understand the process by which financial incentives may impact (or not) on care
A comprehensive analysis of autocorrelation and bias in home range estimation
Home range estimation is routine practice in ecological research. While advances in animal tracking technology have increased our capacity to collect data to support home range analysis, these same advances have also resulted in increasingly autocorrelated data. Consequently, the question of which home range estimator to use on modern, highly autocorrelated tracking data remains open. This question is particularly relevant given that most estimators assume independently sampled data. Here, we provide a comprehensive evaluation of the effects of autocorrelation on home range estimation. We base our study on an extensive data set of GPS locations from 369 individuals representing 27 species distributed across five continents. We first assemble a broad array of home range estimators, including Kernel Density Estimation (KDE) with four bandwidth optimizers (Gaussian reference function, autocorrelated-Gaussian reference function [AKDE], SilvermanÂŽs rule of thumb, and least squares cross-validation), Minimum Convex Polygon, and Local Convex Hull methods. Notably, all of these estimators except AKDE assume independent and identically distributed (IID) data. We then employ half-sample cross-validation to objectively quantify estimator performance, and the recently introduced effective sample size for home range area estimation ((Formula presented.)) to quantify the information content of each data set. We found that AKDE 95% area estimates were larger than conventional IID-based estimates by a mean factor of 2. The median number of cross-validated locations included in the hold-out sets by AKDE 95% (or 50%) estimates was 95.3% (or 50.1%), confirming the larger AKDE ranges were appropriately selective at the specified quantile. Conversely, conventional estimates exhibited negative bias that increased with decreasing (Formula presented.). To contextualize our empirical results, we performed a detailed simulation study to tease apart how sampling frequency, sampling duration, and the focal animalÂŽs movement conspire to affect range estimates. Paralleling our empirical results, the simulation study demonstrated that AKDE was generally more accurate than conventional methods, particularly for small (Formula presented.). While 72% of the 369 empirical data sets had >1,000 total observations, only 4% had an (Formula presented.) >1,000, where 30% had an (Formula presented.) <30. In this frequently encountered scenario of small (Formula presented.), AKDE was the only estimator capable of producing an accurate home range estimate on autocorrelated data.Fil: Noonan, Michael J.. National Zoological Park; Estados Unidos. University of Maryland; Estados UnidosFil: Tucker, Marlee A.. Senckenberg Gesellschaft FĂŒr Naturforschung; . Goethe Universitat Frankfurt; AlemaniaFil: Fleming, Christen H.. University of Maryland; Estados Unidos. National Zoological Park; Estados UnidosFil: Akre, Thomas S.. National Zoological Park; Estados UnidosFil: Alberts, Susan C.. University of Duke; Estados UnidosFil: Ali, Abdullahi H.. Hirola Conservation Programme. Garissa; KeniaFil: Altmann, Jeanne. University of Princeton; Estados UnidosFil: Antunes, Pamela Castro. Universidade Federal do Mato Grosso do Sul; BrasilFil: Belant, Jerrold L.. State University of New York; Estados UnidosFil: Beyer, Dean. Universitat Phillips; AlemaniaFil: Blaum, Niels. Universitat Potsdam; AlemaniaFil: Böhning Gaese, Katrin. Senckenberg Gesellschaft FĂŒr Naturforschung; Alemania. Goethe Universitat Frankfurt; AlemaniaFil: Cullen Jr., Laury. Instituto de Pesquisas EcolĂłgicas; BrasilFil: de Paula, Rogerio Cunha. National Research Center For Carnivores Conservation; BrasilFil: Dekker, Jasja. Jasja Dekker Dierecologie; PaĂses BajosFil: Drescher Lehman, Jonathan. George Mason University; Estados Unidos. National Zoological Park; Estados UnidosFil: Farwig, Nina. Michigan State University; Estados UnidosFil: Fichtel, Claudia. German Primate Center; AlemaniaFil: Fischer, Christina. Universitat Technical Zu Munich; AlemaniaFil: Ford, Adam T.. University of British Columbia; CanadĂĄFil: Goheen, Jacob R.. University of Wyoming; Estados UnidosFil: Janssen, RenĂ©. Bionet Natuuronderzoek; PaĂses BajosFil: Jeltsch, Florian. Universitat Potsdam; AlemaniaFil: Kauffman, Matthew. University Of Wyoming; Estados UnidosFil: Kappeler, Peter M.. German Primate Center; AlemaniaFil: Koch, FlĂĄvia. German Primate Center; AlemaniaFil: LaPoint, Scott. Max Planck Institute fĂŒr Ornithologie; Alemania. Columbia University; Estados UnidosFil: Markham, A. Catherine. Stony Brook University; Estados UnidosFil: Medici, Emilia Patricia. Instituto de Pesquisas EcolĂłgicas (IPE) ; BrasilFil: Morato, Ronaldo G.. Institute For Conservation of The Neotropical Carnivores; Brasil. National Research Center For Carnivores Conservation; BrasilFil: Nathan, Ran. The Hebrew University of Jerusalem; IsraelFil: Oliveira Santos, Luiz Gustavo R.. Universidade Federal do Mato Grosso do Sul; BrasilFil: Olson, Kirk A.. Wildlife Conservation Society; Estados Unidos. National Zoological Park; Estados UnidosFil: Patterson, Bruce. Field Museum of National History; Estados UnidosFil: Paviolo, Agustin Javier. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BiologĂa Subtropical. Instituto de BiologĂa Subtropical - Nodo Puerto IguazĂș | Universidad Nacional de Misiones. Instituto de BiologĂa Subtropical. Instituto de BiologĂa Subtropical - Nodo Puerto IguazĂș; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste; ArgentinaFil: Ramalho, Emiliano Esterci. Institute For Conservation of The Neotropical Carnivores; Brasil. Instituto de Desenvolvimento Sustentavel MamirauĂĄ; BrasilFil: Rösner, Sascha. Michigan State University; Estados UnidosFil: Schabo, Dana G.. Michigan State University; Estados UnidosFil: Selva, Nuria. Institute of Nature Conservation of The Polish Academy of Sciences; PoloniaFil: Sergiel, Agnieszka. Institute of Nature Conservation of The Polish Academy of Sciences; PoloniaFil: Xavier da Silva, Marina. Parque Nacional do Iguaçu; BrasilFil: Spiegel, Orr. Universitat Tel Aviv; IsraelFil: Thompson, Peter. University of Maryland; Estados UnidosFil: Ullmann, Wiebke. Universitat Potsdam; AlemaniaFil: Ziážba, Filip. Tatra National Park; PoloniaFil: Zwijacz Kozica, Tomasz. Tatra National Park; PoloniaFil: Fagan, William F.. University of Maryland; Estados UnidosFil: Mueller, Thomas. Senckenberg Gesellschaft FĂŒr Naturforschung; . Goethe Universitat Frankfurt; AlemaniaFil: Calabrese, Justin M.. National Zoological Park; Estados Unidos. University of Maryland; Estados Unido
Effects of body size on estimation of mammalian area requirements.
Accurately quantifying species' area requirements is a prerequisite for effective area-based conservation. This typically involves collecting tracking data on species of interest and then conducting home range analyses. Problematically, autocorrelation in tracking data can result in space needs being severely underestimated. Based on the previous work, we hypothesized the magnitude of underestimation varies with body mass, a relationship that could have serious conservation implications. To evaluate this hypothesis for terrestrial mammals, we estimated home-range areas with global positioning system (GPS) locations from 757 individuals across 61 globally distributed mammalian species with body masses ranging from 0.4 to 4000 kg. We then applied blockcross validation to quantify bias in empirical home range estimates. Area requirements of mammals 1, meaning the scaling of the relationship changedsubstantially at the upper end of the mass spectrum
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