bluuebunny/crossref_metadata_2025_split huggingface dataset:
Self‐consistent generation of MSTIDs within the SAMI3 numerical model
Authors: Duly Timothy M. , Huba Joseph D. , Makela Jonathan J. 
Published: July 2014

AbstractIn this study, we use the three‐dimensional, physics‐based numerical model, SAMI3 (Sami3 is Another Model of the Ionosphere), to self‐consistently generate nighttime, electrified, medium‐scale traveling ionospheric disturbances (MSTIDs) at midlatitudes. These are the first numerical simulations to use the fundamental, physics‐based equations in a full flux tube model for the self‐consistent generation of MSTIDs. We show that a random perturbation results in the development of modes consistent with the Perkins instability and that the growth rate of a specified k perturbation agrees well with linear theory. We also present synthetic observations of MSTIDs: total electron content, integrated 630.0 nm airglow emission, E × B drift, and electron density. The modeling results show the signature of the instability in the geomagnetic conjugate hemisphere, which has been previously observed experimentally. The qualitative descriptions of the E × B drift and electron density profiles of the MSTIDs provided by SAMI3 are found to be consistent with experimental studies of MSTIDs found in the literature.
The effect of winter drought on evaporation from a high‐elevation wetland
Authors: Blanken Peter D. 
Published: July 2014

AbstractThe surface energy balance of a high‐elevation groundwater‐fed wetland (High Creek Fen) in central Colorado was measured from 9 June 2000 through 18 January 2005. In agreement with observations and predictions for decreased winter snow cover in the region, the low snow cover in 2001–2002 allowed for an examination of the impact of winter drought on the wetland. During years with an average snowpack, summer evaporation far exceeded precipitation. Despite near‐normal summer precipitation following a winter drought, the summertime surface energy balance was affected with decreased latent heat fluxes and increased sensible heat fluxes. The leaf area index and the fraction of photosynthetic radiation absorbed were reduced following the winter drought. A shift in the primary controls on evaporation occurred as the surface's response to vapor pressure deficits and soil moisture increased following the winter drought. The earlier snowmelt coupled with earlier increase in soil temperature and moisture following winter drought did not increase evaporation, since vegetation was not yet developed, and evaporation from soil water was low during the early spring period.
Effects of tidal fluctuations on mixing and spreading in coastal aquifers: Homogeneous case
Authors: Pool María , Post Vincent E. A. , Simmons Craig T. 
Published: July 2014

AbstractWhile the hydraulics of tidally dominated groundwater systems have been studied extensively, tidally induced solute spreading in the fresh‐saltwater transition zone of coastal aquifers remains largely unexplored. Here we systematically quantify tidal impacts on solute mixing and spreading in seawater intrusion problems for an idealized homogeneous system. Mixing is characterized by the spatial moments of the solute concentration distribution and quantified by an effective dispersion coefficient. Parametric analysis reveals that the key dimensionless parameter controlling the tidal mixing behavior is the tidal mixing number (
) which depends on the tidal amplitude, the period and the hydraulic diffusivity. We find that for
, tides lead to a significant impact on the shape and location of the interface. The maximum effect on transverse and longitudinal dispersion occurs for large values of storativity, a hydrogeologic parameter that has been previously understated in terms of its significance. Large storativity implies a nonuniform hydraulic response to the tidal forcing, such that the resulting nonuniform time‐dependent velocity field enhances mixing. As a result, the interface spreads mainly at the bottom of the aquifer, where the saline end of the mixing zone migrates seaward, whereas the spatial extent of low salt concentrations migrates landward. These insights critically underpin quantitative guidance on the inclusion and exclusion of tidal effects in the analysis of seawater intrusion.
Does Increasing Steps Per Day Predict Improvement in Physical Function and Pain Interference in Adults With Fibromyalgia?
Authors: Kaleth Anthony S. , Slaven James E. , Ang Dennis C. 
Published: July 2014

ObjectiveTo examine the concurrent and predictive associations between the number of steps taken per day and clinical outcomes in patients with fibromyalgia (FM).MethodsA total of 199 adults with FM (mean age 46.1 years, 95% women) who were enrolled in a randomized clinical trial wore a hip‐mounted accelerometer for 1 week and completed self‐report measures of physical function (Fibromyalgia Impact Questionnaire‐Physical Impairment [FIQ‐PI], Short Form 36 [SF‐36] health survey physical component score [PCS], pain intensity and interference (Brief Pain Inventory [BPI]), and depressive symptoms (Patient Health Questionnaire‐8 [PHQ‐8]) as part of their baseline and followup assessments. Associations of steps per day with self‐report clinical measures were evaluated from baseline to week 12 using multivariate regression models adjusted for demographic and baseline covariates.ResultsStudy participants were primarily sedentary, averaging 4,019 ± 1,530 steps per day. Our findings demonstrate a linear relationship between the change in steps per day and improvement in health outcomes for FM. Incremental increases on the order of 1,000 steps per day were significantly associated with (and predictive of) improvements in FIQ‐PI, SF‐36 PCS, BPI pain interference, and PHQ‐8 (all P < 0.05). Although higher step counts were associated with lower FIQ and BPI pain intensity scores, these were not statistically significant.ConclusionStep count is an easily obtained and understood objective measure of daily physical activity. An exercise prescription that includes recommendations to gradually accumulate at least 5,000 additional steps per day may result in clinically significant improvements in outcomes relevant to patients with FM. Future studies are needed to elucidate the dose‐response relationship between steps per day and patient outcomes in FM.
Muscle Strength, Muscle Mass, and Physical Disability in Women With Systemic Lupus Erythematosus
Authors: Andrews James S. , Trupin Laura , Schmajuk Gabriela , Barton Jennifer , Margaretten Mary , Yazdany Jinoos , Yelin Edward H. , Katz Patricia P. 
Published: July 2014

ObjectiveData describing relationships between muscle strength, muscle mass, and physical disability among individuals with systemic lupus erythematosus (SLE) are limited. The present study examines the relationship of muscle strength and muscle mass with physical disability among adult women with SLE.MethodsA total of 146 women from a longitudinal SLE cohort participated in the study. All measures were collected during an in‐person research visit. Lower extremity muscle strength was assessed by peak knee torque of extension and flexion and by chair‐stand time. Total lean body mass, appendicular lean mass, and fat mass (kg/m2) were measured by whole‐body dual x‐ray absorptiometry. Self‐reported physical disability was assessed using the Short Form 36 health survey (SF‐36) physical functioning subscale, and the Valued Life Activities (VLA) disability scale. Spearman's rank correlation coefficients tested the correlations between muscle strength, muscle mass, and disability scores. Regression analyses modeled the effect of lower extremity muscle strength and mass on SF‐36 and VLA disability scores controlling for age, SLE duration, SLE disease activity measured with the Systemic Lupus Activity Questionnaire, physical activity level, prednisone use, body composition, and depression.ResultsOn all measures, reduced lower extremity muscle strength was associated with poorer SF‐36 and VLA disability scores. Trends persisted after adjustment for covariates. Muscle mass was moderately correlated with muscle strength, but did not contribute significantly to adjusted regression models.ConclusionLower extremity muscle strength, but not muscle mass, was strongly associated with physical disability scores. While further studies are needed, these findings suggest that improving muscle strength may reduce physical disability among women with SLE.
Associations Between Body Mass Index and Foot Joint Pain in Middle‐Aged and Older Women: A Longitudinal Population‐Based Cohort Study
Authors: Gay Anita , Culliford David , Leyland Kirsten , Arden Nigel K. , Bowen Catherine J. 
Published: July 2014

ObjectiveTo investigate the relationship between body mass index (BMI) and foot joint pain (FJP) over a 5‐year period in a community‐based cohort.MethodsWe examined a subset of women from the Chingford Women's Study, a community cohort followed up for 20 years. From a baseline of 1,003 female participants, we reviewed data from 639 women (64%) for whom complete data sets for FJP and BMI were obtained over a 5‐year period between year 10 (Y10) and year 15 (Y15). Descriptive statistics, binary regression modeling, and odds ratios (ORs) were used to examine the longitudinal relationship between BMI and FJP.ResultsFor Y10 and Y15, the median age was 61 years (interquartile range [IQR] 57–67) and 66 years (IQR 62–72), respectively, and the mean ± SD BMI was 26.7 ± 4.6 kg/m2 and 27.2 ± 4.8 kg/m2, respectively. FJP prevalence was 21.6% at Y10 and 26.6% at Y15. Longitudinal analyses showed that both BMI and FJP increased significantly from Y10 to Y15 (P < 0.001). The odds of having FJP after a 5‐year period increased by 4.9% for each BMI unit increase 5 years earlier (OR 1.049 [95% confidence interval (95% CI) 1.011–1.089], P = 0.012). This remained significant when adjusted for age, diabetes mellitus, and rheumatoid arthritis (OR 1.051 [95% CI 1.011–1.091], P = 0.012).ConclusionThis is the first large longitudinal cohort study demonstrating that, in middle‐aged women, a high BMI precedes and is predictive of FJP independent of age. Evidence from our findings can be used to identify those individuals at risk of developing FJP.
Cost‐Effectiveness Analysis of HLA–B5801 Genotyping in the Treatment of Gout Patients With Chronic Renal Insufficiency in Korea
Authors: Park Dong‐Jin , Kang Ji‐Hyoun , Lee Jeong‐Won , Lee Kyung‐Eun , Wen Lihui , Kim Tae‐Jong , Park Yong‐Wook , Park Sung‐Hwan , Lee Shin‐Seok 
Published: July 2014

ObjectiveAllopurinol‐induced severe cutaneous adverse reactions (SCARs) are relatively rare but cause high rates of morbidity and mortality. Studies have shown that the HLA–B5801 allele and renal impairment are strongly associated with SCARs. Recent American College of Rheumatology guidelines recommend that, prior to treatment with allopurinol, the HLA–B5801 genotype of gout patients at high risk for SCARs, including Korean patients with chronic renal insufficiency, should be determined. However, whether such genotyping is cost‐effective is unknown. This study evaluated the cost‐effectiveness of HLA–B5801 genotyping for the treatment of gout in patients with chronic renal insufficiency in Korea.MethodsA decision analytical model over a time period of 12 months was employed to compare the cost and outcomes of treatment informed by HLA–B5801 genotyping with that of a conventional treatment strategy using a hypothetical cohort of gout patients with chronic renal insufficiency. Direct medical costs were obtained from real patients with SCARs from 2 tertiary hospitals. Outcomes were measured as a total expected cost and an incremental cost‐effectiveness ratio.ResultsIn the base model, the total expected cost and probability of continuation of gout treatment without SCARs for the conventional and HLA–B5801 screening strategies were $1,193 and 97.8% and $1,055 and 100%, respectively. The results were robust according to sensitivity analyses.ConclusionOur model suggests that gout treatment informed by HLA–B5801 genotyping is less costly and more effective than treatment without genotyping, and HLA–B5801 genotyping could considerably reduce the occurrence of allopurinol‐induced SCARs and related deaths.
Definitions for the Sonographic Features of Joints in Healthy Children
Authors: Roth Johannes , Jousse-Joulin Sandrine , Magni-Manzoni Silvia , Rodriguez Ana , Tzaribachev Nikolay , Iagnocco Annamaria , Naredo Esperanza , D'Agostino Maria Antonietta , Collado Paz ,   the Outcome Measures in Rheumatology Ultrasound Group
Published: July 2014

ObjectiveMusculoskeletal ultrasonography (US) has potential in the assessment of disease activity and structural damage in childhood arthritides. In order to assess pathology, the US characteristics of joints in healthy children need to be defined first. The aim of this study was to develop definitions for the various components of the normal pediatric joint.MethodsThe definitions were developed by an expert group and applicability was assessed on a collection of standardized scans of the knee and ankle joints by scoring the scans on a Likert scale. The definitions were then modified and applicability was reassessed before sending the definitions for approval to a larger panel of experts. A final scoring on stored images of all relevant joints at different ages followed.ResultsFive definitions were developed addressing the articular bone, cartilage, joint capsule, epiphyseal ossification center, and synovial membrane. In total, 224 US images of knees and ankles were acquired, of which 172 were selected for scoring. An agreement of ≥80% was not met for any of the definitions, but after modifications, 81–97% agreement was reached. This version of the definitions was approved by 15 US experts. In the final validation exercise, all definitions reached an agreement of ≥80% for the shoulder, elbow, wrist, metacarpophalangeal hip, knee, ankle and metatarsophalangeal joint.ConclusionUS definitions for the normal pediatric joint were successfully developed through a Delphi process and validated in a practical exercise. These results provide the basis to develop definitions for pathology and to support the standardized use of US in pediatric rheumatology.
Development and Retrospective Validation of the Juvenile Spondyloarthritis Disease Activity Index
Authors: Weiss Pamela F. , Colbert Robert A. , Xiao Rui , Feudtner Chris , Beukelman Timothy , DeWitt Esi Morgan , Pagnini Ilaria , Wright Tracey B. , Wallace Carol A. 
Published: July 2014

ObjectiveTo develop and validate the Juvenile Spondyloarthritis Disease Activity Index (JSpADA) for use in clinical practice and research.MethodsUsing modified Delphi consensus techniques, 10 items were selected by participants in the international pediatric rheumatology listserv, the Childhood Arthritis and Rheumatology Research Alliance, and the listserv for the pediatric section of the American College of Rheumatology. Validation was performed in a retrospective multicenter cohort of 244 children.ResultsIn total, 106 physicians representing 14 countries completed the initial questionnaire. Completion rates for the subsequent questionnaires were 84%, 75%, and 77% of the original respondents. Ten items exceeded 80% consensus: arthritis, enthesitis, patient pain assessment, inflammatory markers, morning stiffness, clinical sacroiliitis, uveitis, back mobility, and patient and physician assessments of disease activity. After item analysis, 2 items were eliminated (patient and physician assessments of disease activity). Factor analysis identified 3 primary domains that explained 58% of the variance: peripheral disease, axial disease, and uveitis. The Cronbach's α coefficient was 0.66. The JSpADA had high or moderate correlations with the Juvenile Arthritis Disease Activity Score (r = 0.81), patient and physician assessments of disease activity (r = 0.70 and r = 0.66, respectively), and the Childhood Health Assessment Questionnaire (r = 0.56). The JSpADA discriminated well between subjects with active versus inactive disease (P < 0.001) and was responsive to improvement or worsening in disease activity over time (P < 0.001).ConclusionUsing international input and consensus formation techniques, we developed and validated the first disease activity assessment for juvenile spondyloarthritis. Future studies should validate the JSpADA in a prospective multicenter cohort.
Mapping of the Outcome Measures in Rheumatology Core Set for Antineutrophil Cytoplasmic Antibody‐Associated Vasculitis to the International Classification of Function, Disability and Health
Authors: Milman Nataliya , Boonen Annelies , Merkel Peter A. , Tugwell Peter 
Published: July 2014

ObjectiveThe International Classification of Functioning, Disability and Health (ICF) is a framework and classification of health that describes health along 4 components: body functions, body structures, activities and participation, and contextual factors. This study examined the content of instruments that constitute the Outcome Measures in Rheumatology (OMERACT) core set of outcome measures for antineutrophil cytoplasmic antibody–associated vasculitis (AAV) by “mapping” them to the ICF.MethodsThe content of the instruments included in the AAV core set were linked to the ICF by 2 independent investigators according to previously established ICF linkage rules.ResultsThe AAV core set includes 3 measures of disease activity (3 versions of the Birmingham Vasculitis Activity Score), 1 damage measure (Vasculitis Damage Index), 1 patient‐reported outcome (Short Form 36 health survey), and death. Linking these instruments to the ICF revealed comprehensive coverage of the ICF components body functions and body structures, limited coverage of the ICF component activities and participation, and complete absence of coverage of contextual factors.ConclusionICF was found to be useful for thematic characterization of a heterogeneous group of outcome measures for AAV, i.e., a group of complex medical conditions. Linking of the instruments selected for the OMERACT AAV core set of outcome measures to the ICF classification revealed limitations in the representation of constructs related to life impact of AAV, represented by the ICF components activities and participation and contextual factors. Further research and methods development are needed to better incorporate important aspects of functioning and health relevant to patients into clinical trials of AAV.
Effects of chemical modification of wood flour on the rheological properties of high‐density polyethylene blends
Authors: Ou Rongxian , Wang Qingwen , Wolcott Michael P. , Sui Shujuan , Xie Yanjun , Song Yongming 
Published: July 2014

ABSTRACTChemical modification of lignocellulosic fibers can improve interfacial adhesion and dimensionally stabilize the resulting plastic composites. This study examined the rheological properties of wood flour/high density polyethylene (HDPE) melts after poplar wood flour was modified with glutaraldehyde (GA, mainly cell wall cross‐linking) and 1,3‐dimethylol‐4,5‐dihydroxyethyleneurea (DMDHEU, mainly poly‐condensation). Results show improvement in both the dispersibility of treated wood flour in the HDPE and its interfacial compatibility. Treatment with GA decreased melt viscosity, moduli, and shear stress as evidenced by rheometry. However, the modifying effects of DMDHEU were not observed, which was mainly due to reduced HDPE content. This study indicates that chemical modification of wood flour is a promising approach to improve the processability of highly filled wood thermoplastic composites via extrusion/injection molding processing. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41200.
Brief Report: Erosions and Sclerosis on Radiographs Precede the Subsequent Development of Syndesmophytes at the Same Site: A Twelve‐Year Prospective Followup of Patients With Ankylosing Spondylitis
Authors: Ramiro Sofia , van Tubergen Astrid , van der Heijde Désirée , Stolwijk Carmen , Bookelman Gideon , Dougados Maxime , van den Bosch Filip , Landewé Robert B. M. 
Published: July 2014

ObjectiveTo analyze whether erosions, sclerosis, and squaring assessed on radiographs precede the development of syndesmophytes in patients with ankylosing spondylitis (AS).MethodsPatients with AS from the Outcome in Ankylosing Spondylitis International Study (OASIS) cohort were followed up for 12 years, with radiographs obtained every 2 years. Two readers (reader 1 and reader 2) scored radiographs according to the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) and recorded abnormalities per vertebral corner. Progression from erosions, sclerosis, or squaring to (bridging) syndesmophytes was investigated using multilevel longitudinal (autoregressive and time‐lagged) regression analysis. Interactions with reader and spinal region were investigated.ResultsThe analysis included 211 patients (71% male, 85% HLA–B27 positive) with a mean ± SD age of 43 ± 13 years and a symptom duration of 21 ± 12 years. A total of 921 radiographs were included, with 20,509 (reader 1) and 20,568 (reader 2) vertebral corners evaluable. Erosions were found in 1% and 2.5%, sclerosis in 0.3% and 1.7%, squaring in 6.5% and 5.1%, and syndesmophytes in 25% and 27%, by reader 1 and reader 2, respectively. The odds ratio for a new syndesmophyte to occur within 2 years at the same vertebral corner if erosions, sclerosis, or squaring were present was 2.0 (95% confidence interval [95% CI] 1.7–2.3) for the cervical and lumbar spine together, 3.1 (95% CI 2.5–3.9) for the cervical spine, and 1.3 (95% CI 1.0–1.6) for the lumbar spine. When vertebral corners with erosions, sclerosis, and squaring were analyzed separately, this effect was statistically significant for erosions and for sclerosis, but not for squaring.ConclusionErosions and sclerosis occur infrequently in patients with AS, but when they do occur, they precede the development of a new syndesmophyte, and are therefore important to assess.
Use of Cartilage Derived From Murine Induced Pluripotent Stem Cells for Osteoarthritis Drug Screening
Authors: Willard Vincent P. , Diekman Brian O. , Sanchez‐Adams Johannah , Christoforou Nicolas , Leong Kam W. , Guilak Farshid 
Published: July 2014

ObjectiveThe discovery of novel disease‐modifying drugs for osteoarthritis (OA) is limited by the lack of adequate genetically defined cartilage tissues for application in high‐throughput screening systems. We addressed this need by synthesizing cartilage from induced pluripotent stem cells (iPSCs) to establish and validate an in vitro model of OA.MethodsNative or iPSC‐derived mouse cartilage samples were treated with the cytokine interleukin‐1α (IL‐1α) for 3 days to model the inflammatory environment of OA. The biochemical content, mechanical properties, and gene expression of the resulting tissues were assayed. In addition, the inflammatory and catabolic environment of the media was assessed. To establish high‐throughput capability, we used a 96‐well plate format and conducted a screen of previously identified candidate OA drugs. Glycosaminoglycan (GAG) release into the medium was used as the primary output for screening.ResultsTreatment of iPSC‐derived or native cartilage with IL‐1α induced characteristic features of OA in a rapid and dose‐dependent manner. In addition to the loss of GAGs and tissue mechanical properties, IL‐1α treatment induced the expression of matrix metalloproteinases and increased the production of the inflammatory mediators nitric oxide and prostaglandin E2. In the high‐throughput screen validation, all candidate OA therapeutic agents provided some benefit, but only the NF‐κB inhibitor SC514 effectively reduced cartilage loss in response to IL‐1α.ConclusionThis work demonstrates the utility of iPSCs for studying cartilage pathology and provides a platform for identifying novel, patient‐specific therapeutic agents that prevent cartilage degradation and modify the course of OA development.