bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation of acute myocardial infarction in the Food and Drug Administration's Mini‐Sentinel program
Authors: Cutrona Sarah L. , Toh Sengwee , Iyer Aarthi , Foy Sarah , Daniel Gregory W. , Nair Vinit P. , Ng Daniel , Butler Melissa G. , Boudreau Denise , Forrow Susan , Goldberg Robert , Gore Joel , McManus David , Racoosin Judith A. , Gurwitz Jerry H. 
Published: June 2012

ABSTRACTPurposeTo validate an algorithm based upon International Classification of Diseases, 9th revision, Clinical Modification (ICD‐9‐CM) codes for acute myocardial infarction (AMI) documented within the Mini‐Sentinel Distributed Database (MSDD).MethodsUsing an ICD‐9‐CM‐based algorithm (hospitalized patients with 410.x0 or 410.x1 in primary position), we identified a random sample of potential cases of AMI in 2009 from four Data Partners participating in the Mini‐Sentinel Program. Cardiologist reviewers used information abstracted from hospital records to assess the likelihood of an AMI diagnosis based on criteria from the Joint European Society of Cardiology and American College of Cardiology Global Task Force. Positive predictive values (PPVs) of the ICD‐9‐based algorithm were calculated.ResultsOf the 153 potential cases of AMI identified, hospital records for 143 (93%) were retrieved and abstracted. Overall, the PPV was 86.0% (95% confidence interval; 79.2%, 91.2%). PPVs ranged from 76.3% to 94.3% across the four Data Partners.ConclusionsThe overall PPV of potential AMI cases, as identified using an ICD‐9‐CM‐based algorithm, may be acceptable for safety surveillance; however, PPVs do vary across Data Partners. This validation effort provides a contemporary estimate of the reliability of this algorithm for use in future surveillance efforts conducted using the Food and Drug Administration's MSDD. Copyright © 2012 John Wiley & Sons, Ltd.
Mechanical and thermal properties of phenolic/glass fiber foam modified with phosphorus‐containing polyurethane prepolymer
Authors: Yuan Haixia , Xing Weiyi , Yang Hongyu , Song Lei , Hu Yuan , Yeoh Guan Heng 
Published: June 2012

AbstractPhenolic foam exhibits outstanding flame, smoke and toxicity properties, good insulation properties and low production costs. However, the brittleness and pulverization of phenolic foam have severely limited its application in many fields. In this study, a novel phosphorus‐containing polyurethane prepolymer (DOPU) modifier was firstly synthesized, and then the foaming formula and processing of toughening phenolic foam modified with DOPU and glass fiber were explored. The structure and reactive behavior of prepolymer and phenolic resin were investigated using Fourier transform infrared spectroscopy. The effects of DOPU and glass fiber on the apparent density, compressive strength, bending strength and water absorption were investigated. The results suggested that the apparent density, compressive strength and bending strength of modified phenolic foam tended to increase irregularly with increasing content of DOPU. The addition of DOPU led to lower water absorption of glass fiber‐filled foam. Thermal stability and flame retardancy were examined using thermogravimetric analysis and limiting oxygen index (LOI) tests. It was found that foam with 3% DOPU and 0.5% glass fiber added exhibited good thermal stability and high char yields. The LOI value of modified phenolic foams decreased with increasing DOPU content, but it still remained at 41.0% even if the amount of modifier loaded was 10 wt%. © 2012 Society of Chemical Industry
Evaluation of an operational ice–ocean analysis and forecasting system for the Gulf of St Lawrence
Authors: Smith Gregory C. , Roy François , Brasnett Bruce 
Published: June 2012

AbstractOur ability to simulate and understand oceanic conditions of the Gulf of St Lawrence (GSL) has significantly increased in the last decade with the development of regional ocean models combining scientific knowledge, oceanographic data, and computing techniques. This has created opportunities for their integration with meteorological forecast models where the importance of sea ice–ocean dynamics in air–sea exchanges was recently demonstrated. In order to produce accurate initial conditions for coupled weather forecasts, a GSL ice–ocean ‘pseudo’ analysis (IOPA) system has been developed and implemented operationally at the Canadian Meteorological Centre (CMC). Based on prognostic ice–ocean model solutions the IOPA system has sufficient skill to produce realistic daily fields without flux correction or data assimilation of temperature and salinity. Using only a simple assimilation method for sea‐ice data, daily oceanic fields are obtained and can be used to initialize ice–ocean or coupled atmospheric forecasting systems.A 3‐year retrospective evaluation of this operational method is presented focusing on sea‐surface temperature (SST) and sea‐ice conditions. Model estimates are compared with in situ and satellite‐derived data. Results show that the IOPA system has an accuracy equivalent to or better than the current operational SST and ice analyses produced at the CMC. Together with preceding modelling efforts, this work lays the foundation for the first state‐of‐the‐art GSL ocean analysis and forecast systems combining ocean modelling and real‐time three‐dimensional data assimilation. Coupled atmosphere–ice–ocean forecasts produced with the same ice–ocean model and initialized with the IOPA system are presented in a companion paper. Copyright © 2012 Crown in the right of Canada. Published by John Wiley & Sons Ltd.
A variance reduction framework for stable feature selection
Authors: Han Yue , Yu Lei 
Published: June 2012

AbstractStability of feature selection is an important but under‐addressed issue in knowledge discovery from high‐dimensional data. In this study, we present a theoretical framework about the relationship between the stability and the accuracy of feature selection based on a formal bias‐variance decomposition of feature selection error. The framework also reveals the connection between stability and sample size and suggests a variance reduction approach for improving the stability of feature selection algorithms under small sample size. Following the theoretical framework, we propose an empirical variance reduction framework, margin‐based instance weighting, which weights training instances according to their importance to feature evaluation. Our extensive experimental study first verifies the theoretical and empirical frameworks based on synthetic data sets and a popular feature selection algorithm SVM‐RFE. Experiments based on real‐world microarray data sets further verify that the empirical framework is effective at reducing the variance and improving the subset stability of two representative feature selection algorithms, SVM‐RFE and ReliefF, while maintaining comparable predictive accuracy based on the selected features. The proposed instance weighting framework is also shown to be more effective and efficient than the ensemble framework at improving the subset stability of the feature selection algorithms under study. © 2012 Wiley Periodicals, Inc. Statistical Analysis and Data Mining, 2012
The Fractal Structure of Equine Articular Cartilage
Authors: Smyth Patrick A. , Rifkin Rebecca E. , Jackson Robert L. , Reid Hanson R. 
Published: June 2012

SummaryThe naturally occurring structure of articular cartilage has proven to be an effective means for the facilitation of motion and load support in equine and other animal joints. Cartilage has been found to be a complex and dynamic medium, which has led to an incomplete understanding of the nature and operating mechanisms acting within a joint. Although cartilage has biphasic and triphasic properties, it is believed that the performance of equine articular joints is influenced by the surface roughness of the joint cartilage (Ateshian et al., '98; Chan et al., 2011; Yao and Unsworth, '93). Various joint types with different motions and regimes of lubrication have altered demands on the articular surface that may affect cartilage surface properties. In research performed on freshly harvested samples, equine articular cartilage has been shown to possess a multiscale structure and a fractal dimension. It is thought that by determining the fractal dimension (D) of articular cartilage, a better understanding of the friction, wear, and lubrication mechanisms for biomechanic surfaces can eventually be reached. This study looks at the fractal dimensions of three different articular cartilage surfaces in the equine carpus: the radiocarpal, midcarpal, and carpometacarpal surfaces. The three surfaces provide an ideal comparison of fractal dimensions for a different range of motion, geometry, and loading. In each sample, identical treatment was performed during measurement by a stylus profilometer. SCANNING 34: 418–426, 2012. © 2012 Wiley Periodicals, Inc.
Misdiagnosed ectopic pregnancy mimicking adnexal malignancy: a report of two cases
Authors: Savelli L. , Fabbri F. , Moruzzi C. , Testa A. C. 
Published: June 2012

ABSTRACTWe present two cases of nulliparous women with no history of amenorrhea who were referred to our unit following finding of a hypervascularized solid adnexal mass. In both cases a malignant tumor of tubal origin was suspected at transvaginal sonography. However, following laparoscopy, histological examination revealed that the masses were the result of an undetected tubal ectopic pregnancy that had failed spontaneously, with massive vasodilatation of pelvic blood vessels surrounding the trophoblastic tissue. We recommend consideration of the potential diagnosis of a previously undetected, failed tubal ectopic pregnancy in fertile women presenting with an adnexal mass, even when there is no history of amenorrhea or a positive pregnancy test.
Call‐associated Acute Fatigue in Surgical Residents—Subjective Perception or Objective Fact? A Cross‐sectional Observational Study to Examine the Influence of Fatigue on Surgical Performance
Authors: Schlosser Katja , Maschuw Katja , Kupietz Eva , Weyers Peter , Schneider Ralph , Rothmund Matthias , Hassan Iyad , Bartsch Detlef Klaus 
Published: June 2012

AbstractBackgroundThe effect of acute partial sleep deprivation on surgical proficiency is still controversially discussed. The present study correlated physiological parameters of fatigue with objective technical and cognitive skills, as well as subjective sleepiness of surgical residents. The aim of the study was to assess the effect of acute partial sleep deprivation on surgical performance.MethodsThirty‐eight surgeons were interviewed on three consecutive mornings: prior to a 24 h call, post‐call, and after 24 h of rest. Reported hours of sleep were recorded. Subjective alertness was assessed with the standardized Stanford‐Sleepiness‐Scale (SSS). Saliva cortisol concentrations and pupillary activity were measured by standardized ELISA and pupillography. The virtual reality (VR)‐simulator LapSim was used to assess technical skills through low‐fidelity VR‐tasks (“cutting,” “clip applying”) and cognitive skills through high‐fidelity VR‐tasks (“intracorporeal suturing,” “VR‐cholecystectomy”). Objective alertness was measured by the standardized d2‐Paper‐Pencil Test.ResultsRecorded hours of sleep (p = 0.001) and subjective alertness (SSS) decreased (p = 0.001) significantly post‐call. None of the three factors studied—saliva cortisol concentration (p = 0.313), pupillary activity (p = 0.998), or VR‐performance of low‐fidelity VR‐tasks—differed significantly between assessments. Surprisingly, VR‐performance of high‐fidelity VR‐tasks (error‐score p = 0.044, time to complete task p = 0.0001, economy of instrument motion p = 0.0001) and objective alertness (d2‐Paper‐Pencil Test p = 0.027) significantly improved in the post‐call setting.ConclusionsAcute call‐associated fatigue seems to be a predominantly subjective perception. Physiological factors seem to outbalance an anticipated fatigue‐associated impairment of technical performances within low‐fidelity VR‐tasks. In surgical residents, acute partial sleep deprivation seems to have a positive short‐term effect on cognitive skills, leading to enhanced technical performance and increased objective alertness within complex tasks.
Prospective randomized comparison of open versus laparoscopic management of splenic artery aneurysms: a 10-year study
Authors: Tiberio Guido A. M. , Bonardelli Stefano , Gheza Federico , Arru Luca , Cervi Edoardo , Giulini Stefano M. 
Published: June 2012

AbstractBackgroundThe literature does not support the choice between open and laparoscopic management of splenic artery aneurysms (SAA).MethodsWe designed a prospective, randomized comparison between open and laparoscopic surgery for SAA. Primary end points were types of surgical procedures performed and clinical outcomes. Analysis was developed on an intention-to-treat basis.ResultsFourteen patients were allocated to laparotomy (group A) and 15 to laparoscopy (group B). Groups displayed similar patient- and aneurysm-related characteristics. The conversion rate to open surgery was 13.3 %. The type of surgical procedure performed on the splenic artery was similar in the two groups: aneurysmectomy with splenic artery ligature or direct anastomosis was performed in 51 % and 21 % of patients in group A and in 60 % and 20 % in group B, respectively. The splenectomy rate was similar (14 % vs. 20 %). Postoperative splenic infarction was observed in one case in each group. Laparoscopy was associated with shorter procedures (p = 0.0003) and lower morbidity (25 % vs. 64 %,p = 0.045). Major morbidity requiring interventional procedures and blood transfusion was observed only in group A. Laparoscopy was associated with quicker resumption of oral diet (p < 0.001), earlier drain removal (p = 0.046), and shorter hospital stay (p < 0.01). During a mean follow-up of 50 months, two patients in group A required hospital readmission. In group B, two patients developed a late thrombosis of arterial anastomoses.ConclusionsOur study demonstrates that laparoscopy permits multiple technical options, does not increase the splenectomy rate, and reduces postoperative complications. It confirms the supposed clinical benefits of laparoscopy when ablative procedures are required but laparoscopic anastomoses show poor long-term results.
Coalitional Capacities and Environmental Strategies to Prevent Underage Drinking
Authors: Nargiso Jessica E. , Friend Karen B. , Egan Crystelle , Florin Paul , Stevenson John , Amodei Brenda , Barovier Linda 
Published: June 2012

AbstractCoalitions are the most common platform for implementing community‐level environmental strategies (ES), such as media, policy, or enforcement for substance use prevention. The current study examines the associations between two types of coalition capacity (general and innovation‐specific) and ES implementation efforts and outputs within 14 intervention communities over a three‐year period. Efforts refer to the amount of energy exerted to implement an ES while outputs refer to the materials produced through these efforts. Quantitative measures of capacity were provided by coalition key informants and expert‐raters. Additionally, Training and Technical Assistance (TTA) provided proactively to improve the implementation of ES was also examined. Greater general capacity, as rated by a coalition informant, was associated with more ES policy effort. Both expert‐rated general and innovation‐specific capacity, however, were associated with greater ES outputs. Study results also found that community coalitions that endorsed weaker mobilization, structure and task leadership, (measures of general capacity), utilized more TTA compared to those who perceived their coalition as having greater capacity. Moreover, communities that utilized more TTA resources reported a greater number of successful policy changes. The study supports the need to consider both general and innovation‐specific capacity for ES implementation and offers promising preliminary findings regarding the role of TTA for improving coalitions’ capacity to facilitate policy change.
The modulation of spinal growth with nitinol intervertebral stapling in an established swine model
Authors: Carreau Joseph H. , Farnsworth Christine L. , Glaser Diana A. , Doan Joshua D. , Bastrom Tracey , Bryan Nathan , Newton Peter O. 
Published: June 2012

Purpose Anterior spinal stapling for the treatment of adolescent idiopathic scoliosis has been shown to slow progression in small curves; however, its role in larger curves remains unclear. The purpose of this study was to evaluate the effectiveness of nitinol staples to modulate spinal growth by evaluating the two-dimensional and three-dimensional morphological and histological effects of this method in a well-established porcine model. Methods Three immature Yucatan miniature pigs underwent intervertebral stapling. Two staples spanned each of three consecutive mid-thoracic discs and epiphyses. Monthly radiographs were obtained. Computed tomography (CT) was conducted at harvest after 6 months of growth. Measurements of wedging and height for each disc and vertebral body were conducted. Micro CT was used to compare physeal closure between stapled and non-stapled levels. Histology of the growth plate also compared the hypertrophic zone thickness for control and stapled vertebrae. Results After 6 months of stapled growth, the average coronal Cobb angle of the stapled segments increased by 7.7 ± 2.0° and kyphosis increased by 3.3 ± 0.6° compared to preoperative curves. Increased vertebral wedging and decreased disc height ( p < 0.001) were noted in stapled regions. Overall, 26 ± 23 % of each growth plate was closed in the stapled segments, with 6 ± 8 % closure in the unstapled levels. No difference was observed regarding the hypertrophic zone height when comparing instrumented to uninstrumented levels, nor was a difference recognized when comparing right versus left regions within stapled levels alone. Conclusions Six months of nitinol intervertebral stapling created a mild coronal and sagittal deformity associated with reduced vertebral and disc height, and increased coronal vertebral and sagittal disc wedging.
Perfecting Patient Flow in the Surgical Setting
Authors: Amato‐Vealey Elaine J. , Fountain Patricia , Coppola Deborah 
Published: June 2012

AbstractReduced surgical efficiency and productivity, delayed patient discharges, and prolonged use of hospital resources are the results of an OR that is unable to move patients to the postanesthesia care unit or other patient units. A primary reason for perioperative patient flow delay is the lack of hospital beds to accommodate surgical patients, which consequently causes backups of patients currently in the surgical suite. In one facility, implementing Six Sigma methodology helped to improve OR patient flow by identifying ways that frontline staff members could work more intelligently and more efficiently, and with less stress to streamline workflow and eliminate redundancy and waste in ways that did not necessitate reducing the number of employees. The results were improved employee morale, job satisfaction and safety, and an enhanced patient experience.
Creative Alaska: creative capital and economic development opportunities in Alaska
Authors: Petrov Andrey N. , Cavin Philip A. 
Published: June 2012

ABSTRACTThe flaws of the 20th century–type development ‘mega–projects’ in the circumpolar North prompt Arctic regions actively to search for alternative strategies of regional development that break away from resource–dependency and reconcile local (traditional) societies with the realities of post–Fordism and globalisation. This paper presents a study that focuses on the notion of creative capital (CC) and assesses its ability to foster economic development in Alaska. The findings suggest that some characteristics of the CC observed in Alaskan communities are similar to those found in southern regions, whereas others are distinct (but similar to those in the Canadian North). In Alaska, the synergy between cultural economy, entrepreneurship and leadership appear to be more important in characterising creative capacities than formal education. The geographical distribution of the CC is uneven and heavily clustered in economically, geographically and politically privileged northern urban centres. However, some remote regions also demonstrate considerable levels of creative potential, in particular associated with the aboriginal cultural capital (artists, crafters, etc.). A number of Alaskan regions, creative ‘hot spots’, could become places that can benefit from alternative strategies of regional development based on CC, knowledge–based and cultural economies.
Helicity of vector fields preserving a regular contact form and topologically conjugate smooth dynamical systems
Authors: MÜLLER STEFAN , SPAETH PETER 
Published: June 2012

AbstractWe compute the helicity of a vector field preserving a regular contact form on a closed three-dimensional manifold, and improve results of Gambaudo and Ghys [Enlacements asymptotiques. Topology 36(6) (1997), 1355–1379] relating the helicity of the suspension of a surface isotopy to the Calabi invariant of the isotopy. Based on these results, we provide positive answers to two questions posed by Arnold in [The asymptotic Hopf invariant and its applications. Selecta Math. Soviet. 5(4) (1986), 327–345]. In the presence of a regular contact form that is also preserved, the helicity extends to an invariant of an isotopy of volume-preserving homeomorphisms, and is invariant under conjugation by volume-preserving homeomorphisms. A similar statement also holds for suspensions of surface isotopies and surface diffeomorphisms. This requires the techniques of topological Hamiltonian and contact dynamics developed by Banyaga and Spaeth [On the uniqueness of generating Hamiltonians for topological strictly contact isotopies.Preprint, 2012], Buhovsky and Seyfaddini [Uniqueness of generating Hamiltonians for continuous Hamiltonian flows. J. Symplectic Geom. to appear, arXiv:1003.2612v2], Müller [The group of Hamiltonian homeomorphisms in the$L^\infty $-norm. J. Korean Math. Soc.45(6) (2008), 1769–1784], Müller and Oh [The group of Hamiltonian homeomorphisms and$C^0$-symplectic topology. J. Symplectic Geom. 5(2) (2007), 167–219], Müller and Spaeth [Topological contact dynamics I: symplectization and applications of the energy-capacity inequality.Preprint, 2011, arXiv:1110.6705v2] and Viterbo [On the uniqueness of generating Hamiltonian for continuous limits of Hamiltonians flows. Int. Math. Res. Not. (2006), 34028; Erratum,Int. Math. Res. Not.(2006), 38748]. Moreover, we generalize an example of Furstenberg [Strict ergodicity and transformation of the torus. Amer. J. Math. 83(1961), 573–601] on topologically conjugate but not$C^1$-conjugate area-preserving diffeomorphisms of the two-torus to trivial$T^2$-bundles, and construct examples of Hamiltonian and contact vector fields that are topologically conjugate but not$C^1$-conjugate. Higher-dimensional helicities are considered briefly at the end of the paper.