bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observation and inpatient status: Clinical impact of the 2‐midnight rule
Authors: Sheehy Ann M. , Caponi Bartho , Gangireddy Sreedevi , Hamedani Azita G. , Pothof Jeffrey J. , Siegal Eric , Graf Ben K. 
Published: February 2014

BACKGROUNDIn response to growing concern over frequency and duration of observation encounters, the Centers for Medicare and Medicaid Services enacted a rules change on October 1, 2013, classifying most hospital encounters of <2 midnights as observation, and those ≥2 midnights as inpatient. However, limited data exist to predict the impact of the new rule.OBJECTIVETo answer the following: (1) Will the rule reduce observation encounter frequency? (2) Are short‐stay (<2 midnights) inpatient encounters often misclassified observation encounters? (3) Do 2 midnights separate distinct clinical populations, making this rule logical? (4) Do nonclinical factors such as time of day of admission impact classification under the rule?DESIGN, SETTING AND PATIENTSRetrospective descriptive study of all observation and inpatient encounters initiated between January 1, 2012 and February 28, 2013 at a Midwestern academic medical center.MEASUREMENTSDemographics, insurance type, and characteristics of hospitalization were abstracted for each encounter.RESULTSOf 36,193 encounters, 4,769 (13.2%) were observation. Applying the new rules predicted a net loss of 14.9% inpatient stays; for Medicare only, a loss of 7.4%. Less than 2‐midnight inpatient and observation stays were different, sharing only 1 of 5 top International Classification of Diseases, 9th Revision (ICD‐9) codes, but for encounters classified as observation, 4 of 5 top ICD‐9 codes were the same across the length of stay. Observation encounters starting before 8:00 am less commonly spanned 2 midnights (13.6%) than later encounters (31.2%).CONCLUSIONSThe 2‐midnight rule adds new challenges to observation and inpatient policy. These findings suggest a need for rules modification. Journal of Hospital Medicine 2014;9:203–209. © 2014 Society of Hospital Medicine
Risk factors for potentially avoidable readmissions due to end‐of‐life care issues
Authors: Donzé Jacques , Lipsitz Stuart , Schnipper Jeffrey L. 
Published: February 2014

BACKGROUNDRepeated hospitalizations are frequent toward the end of life, where each admission should be an opportunity to initiate advance‐care planning to high‐risk patients.OBJECTIVETo identify the risk factors for having a 30‐day potentially avoidable readmission due to end‐of‐life care issues among all medical patients.DESIGNNested case‐control study.SETTING/PATIENTSAll 10,275 consecutive discharges from any medical service of an academic tertiary medical center in Boston, Massachusetts between July 1, 2009 and June 30, 2010.MEASUREMENTSA random sample of all the potentially avoidable 30‐day readmissions was independently reviewed by 9 trained physicians to identify the ones due to end‐of‐life issues.RESULTSAmong 534, 30‐day potentially avoidable readmission cases reviewed, 80 (15%) were due to an end‐of‐life care issue. In multivariable analysis, the following risk factors were significantly associated with a 30‐day potentially avoidable readmission due to end‐of‐life care issues: number of admissions in the previous 12 months (odds ratio [OR]: 1.10 per admission, 95% confidence interval [CI]: 1.02‐1.20), neoplasm (OR: 5.60, 95% CI: 2.85‐10.98), opiate medications at discharge (OR: 2.29, 95% CI: 1.29‐4.07), Elixhauser comorbidity index (OR: 1.16 per 5‐point increase, 95% CI: 1.10‐1.22). The discrimination of the model (C statistic) was 0.85.CONCLUSIONSIn a medical population, we identified 4 main risk factors that were significantly associated with 30‐day potentially avoidable readmission due to end‐of‐life care issues, producing a model with very good to excellent discrimination. Patients with these risk factors might benefit from palliative care consultation prior to discharge in order to improve end‐of‐life care and possibly reduce unnecessary rehospitalizations. Journal of Hospital Medicine 2014;9:310–314. © 2014 Society of Hospital Medicine
Give them what they want or give them what they need? Ideology in the study of leadership
Authors: Mumford Michael D. , Fried Yitzhak 
Published: February 2014

SummaryIn recent years, a number of new, values‐based, or ideological models focusing on leader behavior have been proposed. These models include authentic, servant, character‐based, ethical, spiritual, and aesthetic leadership. In the present effort, we argue that these models, despite some differences in key dimensions, are tied together by a focus on moral behavior. The available evidence indicates that these models have only modest predictive power with respect to organizational performance criteria. More centrally, we argue that tests of these models are characterized by significant methodological problems with respect to both measurement and control. Moreover, these models suffer from some serious substantive concerns, including the explicit confounding of leadership and morality, discounting of system impacts, inappropriate assumptions about follower needs, and inappropriate scientific inferences. These models also fail to provide viable new approaches for leader development. We conclude that caution must be exercised when these models are employed as a basis for understanding leadership. Copyright © 2014 John Wiley & Sons, Ltd.
The role of changing multiscale temperature variability in extreme temperature events on the eastern and central Tibetan Plateau during 1960–2008
Authors: Song Ci , Pei Tao , Zhou Chenghu 
Published: February 2014

ABSTRACTVariability is a very important inherent characteristic of climate and it varies on all timescales. It is also considered an important factor regarding changes of extreme events. On the basis of daily temperature records at 63 stations in the eastern and central Tibetan Plateau during 1960–2008, we examine changes of temperature mean, variability and extremes for the region, and study correlations between multiscale temperature variability and various extreme temperature events. Results show that considering the entire study region, a significantly decreasing trend is observed for intra‐annual temperature variability (StdD), whereas a significantly increasing trend is observed for interannual temperature variability (IVT). Further relationships between multiscale temperature variability and temperature extremes over the past 49 years show that IVT is positively correlated with cold/warm nights (TN10/TN90) and warm days (TX90), whereas StdD is positively correlated with cold extremes (TN10/TX10) and negatively correlated with warm extremes (TN90/TX90). Nevertheless, annual mean temperature also plays an important role in the relationships between temperature variability and temperature extremes, for correlations between IVT and cold temperature extremes in two warming periods are quite different. Stations with different temperature trends for mean, variability and extremes in the two warming periods are categorized in the study region, and these temperature characteristics in each category are also affected by local effects, such as elevation, topography and urbanization. However, in strong warming periods, the change of mean temperature still has a dominant effect on extreme temperature events.
The effect of an additional phosphite stabilizer on the properties of radiation cross‐linked vitamin E blends of UHMWPE
Authors: Oral Ebru , Neils Andrew , Yabannavar Pooja , Muratoglu Orhun K. 
Published: February 2014

ABSTRACTAntioxidant stabilization of radiation cross‐linked ultrahigh molecular weight polyethylene (UHMWPE) has been introduced to improve the oxidative stability of total joint implant bearing surfaces. Blending of an antioxidant with UHMWPE resin powder followed by consolidation and radiation cross‐linking has been cleared by the FDA for use in both total hips and total knees for designs incorporating two antioxidants, namely vitamin E and Covernox™ (a medical grade version of Irganox™ 1010). The antioxidants in the polymer are expected to protect the polymer during consolidation, during radiation cross‐linking, on the shelf before implantation, and in vivo after implantation. To maximize the protection of the polymer afforded by the antioxidant in vivo, a novel approach may be the use of multiple antioxidants, especially to protect the primary antioxidant for a longer period of time. We hypothesized that the addition of a phosphite stabilizer (Irgafos 168™) commonly used in conjunction with hindered phenolic antioxidants in polymer processing could improve the oxidative stability of radiation cross‐linked blends of vitamin E. To test our hypothesis, we prepared UHMWPE blends with 0.05 wt% Irgafos and 0.05 wt% vitamin E and compared its cross‐link density, wear resistance, tensile properties, and impact strength to control blends containing only vitamin E. Our hypothesis was not supported; the cross‐link density of UHMWPE was significantly decreased by the additive without additional benefit to oxidative stability. To our knowledge, this was the first attempt at using multiple stabilizers in medical grade UHMWPE. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:757–761, 2014.
Learning by doing—teaching systematic review methods in 8 weeks
Authors: Li Tianjing , Saldanha Ian J. , Vedula S. Swaroop , Yu Tsung , Rosman Lori , Twose Claire , N. Goodman Steven , Dickersin Kay 
Published: February 2014

ObjectiveThe objective of this paper is to describe the course “Systematic Reviews and Meta‐analysis” at the Johns Hopkins Bloomberg School of Public Health.MethodsA distinct feature of our course is a group project in which students, assigned to multi‐disciplinary groups, conduct a systematic review. In‐class sessions comprise didactic lectures, hands‐on exercises, demonstrations, discussion, and group work. Students also work outside of class to complete the systematic review. Students evaluated the course at the end of the term. We also surveyed students from 2004 to 2012 to learn more about the long‐term impact of the course.ResultsThe course has been offered to more than 800 students since 1995. In our view, aspects that worked well include the hands‐on approach, students working in a multidisciplinary group, intensive interaction with the teaching team, moving to an online approach, and continuous updates of the course content. A persistent issue is the constraint of time. 193 of 211 (91%) survey participants reported that the course is currently useful or as having an impact on their work.ConclusionsOur experiences have led us to remain committed to a hands‐on approach. Our course serves as a bridge between classroom learning and real‐world practice, and provides an example of teaching systematic review. Copyright © 2014 John Wiley & Sons, Ltd.
Sentinel lymph node biopsy during prophylactic mastectomy: Is there a role?
Authors: Bunting Pamela W. , Cyr Amy E. , Gao Feng , Margenthaler Julie A. 
Published: February 2014

PurposeWe investigated rates of occult malignancy in the breast and sentinel lymph nodes (SLNs) in patients undergoing prophylactic mastectomy (PM) and whether routine sentinel lymph node biopsy (SLNB) is justified.MethodsA retrospective review of our database identified patients undergoing PMs with SLNB. Descriptive statistics were utilized for data summary. A P value of <0.05 was considered significant.ResultsThere were 384 patients during the study period who underwent 467 PMs. Of the 467 PMs, 15 (3.2%) cancers were found on final pathology. All 6 of the invasive cancers identified were T1. A total of 682 SLNs were taken for an average of 1.46 SLNs per PM. There were 5 positive SLNs (1.1%). All were in patients undergoing contralateral PM for either history of breast cancer or new diagnosis of breast cancer. Only one patient with a positive SLN was found to have an occult breast malignancy in the PM specimen.ConclusionIn 467 PMs performed, 15 (3.2%) occult malignancies were found in the breast and 5 (1.1%) positive SLNs were found. Based on these results, the routine use of SLNB at the time of PM is unnecessary and does not warrant the morbidity associated with this procedure. J. Surg. Oncol. 2014 109:747–750. © 2014 Wiley Periodicals, Inc.
Essential tremor is not associated with cerebellar Purkinje cell loss
Authors: Symanski Claire , Shill Holly A. , Dugger Brittany , Hentz Joseph G. , Adler Charles H. , Jacobson Sandra A. , Driver‐Dunckley Erika , Beach Thomas G. 
Published: February 2014

ABSTRACTThere has been controversy as to whether there is an underlying neurodegenerative process of the cerebellum in essential tremor (ET). The aim of this study was to examine whether ET is associated with Purkinje cell (PC) loss. Prospectively categorized ET and control subjects who were longitudinally examined in the Arizona Study for Aging and Neurodegenerative Disorders and came to autopsy between 1998 and 2013 underwent standardized neuropathological assessment of the brain. PC linear density of the cerebellar hemisphere was calculated in a blinded manner. There were 56 ET cases and 62 age‐matched controls free of dementia and other neurodegenerative disorders included in the study. Mean PC linear density was 3.80 ± 0.81 cells per mm for tremor cases and 3.82 ± 0.91 cells per mm for controls (Δ 0.02; 95% confidence interval [CI]: −0.30‐0.34). PC counts were not associated with tremor duration (r = 0.06; 95% CI: −0.21‐0.32). These data demonstrate that ET is not associated with cerebellar PC loss. © 2014 International Parkinson and Movement Disorder Society
PANDA‐T1ρ: Integrating principal component analysis and dictionary learning for fast T1ρ mapping
Authors: Zhu Yanjie , Zhang Qinwei , Liu Qiegen , Wang Yi‐Xiang J. , Liu Xin , Zheng Hairong , Liang Dong , Yuan Jing 
Published: February 2014

PurposeLong scanning time greatly hinders the widespread application of spin‐lattice relaxation in rotating frame (
) in clinics. In this study, a novel method is proposed to reconstruct the
‐weighted images from undersampled k‐space data and hence accelerate the acquisition of
imaging.MethodsThe proposed approach (PANDA‐
) combined the benefit of PCA and dictionary learning when reconstructing image from undersampled data. Specifically, the PCA transform was first used to sparsify the image series along the parameter direction and then the sparsified images were reconstructed by means of dictionary learning and finally solved the images. A variation of PANDA‐
was also developed for the heavy noise case. Numerical simulation and in vivo experiments were carried out with the accelerating factor from 2 to 4 to verify the performance of PANDA‐
.ResultsThe reconstructed
maps using the PANDA‐
method were found to be comparable to the reference at all verified acceleration factors. Moreover, the variation exhibited better performance than the original version when the k‐space data were contaminated by heavy noise.ConclusionPANDA‐
can significantly reduce the scanning time of
by integrating PCA and dictionary learning and provides better parameter estimation than the state‐of‐art methods for a fixed acceleration factor. Magn Reson Med 73:263–272, 2015. © 2014 Wiley Periodicals, Inc.
Proton diffusion tensor spectroscopy of metabolites in human muscle in vivo
Authors: Brandejsky Vaclav , Boesch Chris , Kreis Roland 
Published: February 2014

PurposeTo study the apparent diffusivity and its directionality for metabolites of skeletal muscle in humans in vivo by 1H magnetic resonance spectroscopy.MethodsThe diffusion tensors were determined on a 3 Tesla MR system using optimized acquisition and processing methods including an adapted STEAM sequence with orientation‐dependent diffusion weighting, pulse‐triggering with individually adapted delays, eddy‐current correction schemes, median filtering, and simultaneous prior‐knowledge fitting of all related spectra.ResultsThe average apparent diffusivities, as well as the fractional anisotropies of taurine (ADCav = 0.74 × 10−3s/mm2, FA = 0.46), creatine (ADCav = 0.41 × 10−3 s/mm2, FA = 0.33), trimethylammonium compounds (ADCav = 0.48 × 10−3 s/mm2, FA = 0.34), carnosine (ADCav = 0.46 × 10−3 s/mm2, FA = 0.47), and water (ADCav = 1.5 × 10−3 s/mm2, FA = 0.36) were estimated. The diffusivities of most metabolites and water were significantly different from each other. Diffusion was found to be anisotropic and the diffusion tensors showed tensor correlation coefficients close to 1 and were hence found to be essentially coaligned. The magnitudes of apparent metabolite diffusivities were largely ordered according to molecular weight, with taurine as the smallest molecule diffusing fastest, both along and across the fiber direction.ConclusionDiffusivities, directional dependence of diffusion and fractional anisotropies of 1H MRS‐visible muscle metabolites were presented. It was shown that metabolites share diffusion directionality with water and have similar fractional anisotropies, hinting at similar diffusion barriers. Magn Reson Med 73:481–487, 2015. © 2014 Wiley Periodicals, Inc.
Assessment of cardiac time intervals using high temporal resolution real‐time spiral phase contrast with UNFOLDed‐SENSE
Authors: Kowalik Grzegorz T. , Knight Daniel S. , Steeden Jennifer A. , Tann Oliver , Odille Freddy , Atkinson David , Taylor Andrew , Muthurangu Vivek 
Published: February 2014

PurposeTo develop a real‐time phase contrast MR sequence with high enough temporal resolution to assess cardiac time intervals.MethodsThe sequence utilized spiral trajectories with an acquisition strategy that allowed a combination of temporal encoding (Unaliasing by fourier‐encoding the overlaps using the temporal dimension; UNFOLD) and parallel imaging (Sensitivity encoding; SENSE) to be used (UNFOLDed‐SENSE). An in silico experiment was performed to determine the optimum UNFOLD filter. In vitro experiments were carried out to validate the accuracy of time intervals calculation and peak mean velocity quantification. In addition, 15 healthy volunteers were imaged with the new sequence, and cardiac time intervals were compared to reference standard Doppler echocardiography measures. For comparison, in silico, in vitro, and in vivo experiments were also carried out using sliding window reconstructions.ResultsThe in vitro experiments demonstrated good agreement between real‐time spiral UNFOLDed‐SENSE phase contrast MR and the reference standard measurements of velocity and time intervals. The protocol was successfully performed in all volunteers. Subsequent measurement of time intervals produced values in keeping with literature values and good agreement with the gold standard echocardiography. Importantly, the proposed UNFOLDed‐SENSE sequence outperformed the sliding window reconstructions.ConclusionCardiac time intervals can be successfully assessed with UNFOLDed‐SENSE real‐time spiral phase contrast. Real‐time MR assessment of cardiac time intervals may be beneficial in assessment of patients with cardiac conditions such as diastolic dysfunction. Magn Reson Med 73:749–756, 2015. © 2014 Wiley Periodicals, Inc.
A novel computational approach for large deformation and post‐failure analyses of segmental retaining wall systems
Authors: Bui Ha H. , Kodikara Jayantha K. , Bouazza Abdelmalek , Haque Asadul , Ranjith Pathegama G. 
Published: February 2014

SUMMARYSegmental retaining wall (SRW) systems are commonly used in geotechnical practice to stabilize cut and fill slopes. Because of their flexibility, these systems can tolerate minor movements and settlements without incurring damage or crack. Despite these advantages, very few numerical studies of large deformations and post‐failure behavior of SRW systems are found in the current literature. Traditional numerical methods, such as the finite element method, suffer from mesh entanglement, thus are unable to simulate large deformations and flexible behavior of retaining wall blocks in SRW systems. To overcome the above limitations, a novel computational framework based on the smoothed particle hydrodynamics (SPH) method was developed to simulate large deformations and post‐failure behavior of soils and retaining wall blocks in SRW systems. The proposed numerical framework is a hybrid continuum/discontinuum approach that can model soil as an elasto‐plastic material and retaining wall blocks as independent rigid bodies associated with both translational and rotational degrees of freedom. A new contact model is proposed within the SPH framework to simulate the interaction between the soil and the blocks and between the blocks. As an application of the proposed numerical method, a two‐dimensional simulation of an SRW collapse was simulated and compared to experimental results conducted under the same conditions. The results showed that the proposed computational approach provided satisfactory agreement with the experiment. This suggests that the new framework is a promising numerical approach to model SRW systems. Copyright © 2014 John Wiley & Sons, Ltd.
Constructing a strict total order for alternatives characterized by multiple criteria: An extension
Authors: Dehnokhalaji Akram , Korhonen Pekka J. , Köksalan Murat , Nasrabadi Nasim , Tezcaner Öztürk Diclehan , Wallenius Jyrki 
Published: February 2014

AbstractThe problem of finding a strict total order for a finite set of multiple criteria alternatives is considered. Our research extends previous work by us, which considered finding a partial order for a finite set of alternatives. We merge the preference information extracted from the preference cones and corresponding polyhedral sets, with the information derived from pairwise comparisons of two alternatives, yielding a preference matrix. This preference matrix is used as input to an integer programming model to obtain a strict total order that provides a transitive ranking for the set of alternatives. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 155–163, 2014
Modeling and analysis of exhaustive probabilistic search
Authors: Chung Timothy H. , Silvestrini Rachel T. 
Published: February 2014

AbstractThis article explores a probabilistic formulation for exhaustive search of a bounded area by a single searcher for a single static target. The searcher maintains an aggregate belief of the target's presence or absence in the search area, concluding with a positive or negative search decision on crossing of decision thresholds. The measure of search performance is defined as the expected time until a search decision is made as well as the probability of the search decision being correct. The searcher gathers observations using an imperfect detector, that is, one with false positive and negative errors, and integrates them in an iterative Bayesian manner. Analytic expressions for the Bayesian update recursion of the aggregate belief are given, with theoretical results describing the role of positive and negative detections, as well as sensitivity results for the effect of the detection errors on the aggregate belief evolution. Statistical studies via design of simulation experiments provide insights into the significant search parameters, including imperfect sensor characteristics, initial belief value, search decision threshold values, and the available prior probability information. Regression analysis yields statistical models to provide prescriptive guidance on the search performance as a function of these search parameters.Copyright © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 164–178, 2014