bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolated regions of remote triggering in South/Southeast Asia following the 2012 Mw 8.6 Indian Ocean earthquake
Authors: Bansal Abhey Ram , Yao Dongdong , Peng Zhigang , Sianipar Dimas 
Published: October 2016

AbstractLarge earthquakes are capable of triggering either shallow earthquakes or deep tectonic tremors at long‐range distances. So far, most of remotely triggered tremors were found along major plate boundary faults around the Pacific Rim. Here we conduct a systematic search for remotely triggered earthquakes and tremors in South/Southeast Asia following the 11 April 2012 Mw 8.6 Indian Ocean earthquake. We find additional evidence of triggered tectonic tremors beneath the Java Island and the Sulabes Island in Eastern Indonesia and triggered earthquakes in Vietnam. Tremors mostly occurred during the large‐amplitude Rayleigh waves of the Indian Ocean main shock and were also triggered by several other large distant earthquakes. Although we are unable to locate them, they were recorded at stations close to major tectonic faults, suggesting that they are likely of tectonic origin. However, we find no evidence of triggered tremor/earthquakes along the Sumatra subduction zone and eastern portion of Himalaya frontal thrusts, indicating that remote triggering was not as widespread as previously thought.
An advective mechanism for deep chlorophyll maxima formation in southern Drake Passage
Authors: Erickson Zachary K. , Thompson Andrew F. , Cassar Nicolas , Sprintall Janet , Mazloff Matthew R. 
Published: October 2016

AbstractWe observe surface and subsurface fluorescence‐derived chlorophyll maxima in southern Drake Passage during austral summer. Backscatter measurements indicate that the deep chlorophyll maxima (DCMs) are also deep biomass maxima, and euphotic depth estimates show that they lie below the euphotic layer. Subsurface, offshore and near‐surface, onshore features lie along the same isopycnal, suggesting advective generation of DCMs. Temperature measurements indicate a warming of surface waters throughout austral summer, capping the winter water (WW) layer and increasing off‐shelf stratification in this isopycnal layer. The outcrop position of the WW isopycnal layer shifts onshore, into a surface phytoplankton bloom. A lateral potential vorticity (PV) gradient develops, such that a down‐gradient PV flux is consistent with offshore, along‐isopycnal tracer transport. Model results are consistent with this mechanism. Subduction of chlorophyll and biomass along isopycnals represents a biological term not observed by surface satellite measurements which may contribute significantly to the strength of the biological pump in this region.
State of stress in Texas: Implications for induced seismicity
Authors: Lundstern Jens‐Erik , Zoback Mark D. 
Published: October 2016

AbstractCompilation of almost 200 new maximum horizontal stress (SHmax) orientations in Texas reveals a complex intraplate stress field. A large extensional stress province is associated with extensive growth faulting from northeastern Mexico to Louisiana. SHmax is subparallel to the coastline, following the strikes of the growth faults. In contrast, we observe a strike‐slip/normal faulting regime with SHmax approximately E‐W in much of west Texas and the Texas Panhandle, similar to the stress fields observed in northeast New Mexico and north‐central Oklahoma. Within the Fort Worth Basin in northeast Texas, SHmax is NNE‐SSW. The faulting regime transitions from strike‐slip/normal faulting in the northern part of the basin to normal faulting with subequal horizontal principal stress magnitudes further south. Recent sites of apparently injection‐related seismicity near Snyder/Cogdell (west Texas), Karnes City/Fashing (south Texas), the Dallas‐Fort Worth metroplex, and Timpson (east Texas) involves fault slip compatible with local stress fields.
New insights into the complex interplay between drag forces and its thermospheric consequences
Authors: Hsu Vicki W. , Thayer Jeffrey P. , Wang Wenbin , Burns Alan 
Published: October 2016

AbstractDrag forces, ion and viscous, are evaluated as modifiers of global wind and temperature structure in the upper thermosphere, shedding new light on their relative roles in neutral dynamics and energetics. Exploiting the coupling of an ionosphere‐thermosphere model, it is discovered that ion and viscous drag forces lead to sustained divergent winds, adjustments in mass, modification of pressure gradients, and a redistribution of the radiatively forced thermal energy. The interplay between the relative magnitudes of the ion and viscous drag forces and its effect on the ionosphere‐thermosphere system has not yet been addressed and results in diverse behavior in the neutral wind and temperature structures of the upper atmosphere, dependent upon the type of drag acting on the gas. It is found that viscous drag is more efficient in cooling the dayside thermosphere and heating the nightside than the ion drag force in solar maximum and under quiet geomagnetic activity, resulting in a 150 K day‐night temperature difference. The ion drag force inhibits this effective day‐to‐night energy circulation, culminating in a dynamically induced difference of about 400 K in the day‐night temperature difference. It is demonstrated that the resultant wind and thermal structure greatly depends on the type of drag force environment, and a mechanism is introduced whereby ion and viscous drag forces can alter the energy budget of the upper thermosphere system. For example, in solar minimum, viscous drag is significant relative to other forces and more effectively cools the dayside and warms the nightside, thereby reducing the day‐night temperature gradient.
Ionospheric detection and localization of volcano eruptions on the example of the April 2015 Calbuco events
Authors: Shults Ksenia , Astafyeva Elvira , Adourian Sévan 
Published: October 2016

AbstractUsing data from ground‐based Global Navigation Satellite Systems (GNSS) receivers located in southern Chile, we study the ionospheric total electron content (TEC) response to two eruptions of the Calbuco volcano that occurred on 22–23 April 2015. In both cases, the TEC response showed quasi‐periodic signals with several consecutive wave trains. The averaged amplitude of the observed covolcanic TEC perturbations amounted 0.45 total electron content unit, 1 TECU = 1016 el m−2 (TECU) for the first eruption and 0.16 TECU for the second one. We compare amplitudes of the TEC response to volcano eruptions of different intensity from our and previously published data, and we show that both the intensity and the background ionospheric conditions define the amplitude of ionospheric covolcanic disturbances. The relative contribution, however, scales with the eruption intensity. The traveltime diagrams allowed to estimate the propagation speed of the observed covolcanic TEC perturbations as ~900–1200 m/s, which is close to the acoustic (or shock acoustic) waves speed at the ionospheric height. The spectrograms are consistent with the conclusion on the acoustic nature of the observed TEC perturbations. Finally, we use the approximation of a spherical wave propagating at a constant velocity from a point source, and for the first time, we calculate the location of the volcanic source and the onset time of the volcano eruption from ionospheric measurements. We show that even from 30 s ionospheric GPS data it is possible to “localize” the eruptive source within several degrees of latitude/longitude.
Nanodust shedding and its potential influence on dust‐related phenomena in the mesosphere
Authors: Havnes O. , Hartquist T. W. 
Published: October 2016

AbstractWe explore the possibility that some meteoric smoke particles that collide with larger nanoparticles near the mesopause can escape from the larger particles by capturing surface electrons. If the process were sufficiently efficient, under certain conditions it would influence the responses of polar mesospheric summer echoes to artificial heating in a manner that is compatible with observations that are unexplained with previous models. The process would have a number of other possible consequences for nanoparticles near the mesopause.
Utilization of Care Outside the Veterans Affairs Health Care System by US Veterans With Rheumatoid Arthritis
Authors: Schwab Pascale , Sayles Harlan , Bergman Debra , Cannon Grant W. , Michaud Kaleb , Mikuls Ted R. , Barton Jennifer 
Published: October 2016

ObjectiveMany veterans enrolled in Veterans Affairs (VA) health care systems also receive care through other health care systems. Both VA and non‐VA health care use must therefore be considered when conducting research in this population. This study characterized dual‐care utilization in veterans with rheumatoid arthritis (RA) and explored associations with RA disease activity.MethodsThrough a questionnaire mailed to RA patients at 3 VA sites, veterans reported medical services by non‐VA primary care and subspecialty providers, comorbidities, non‐VA medications, and hospitalizations. Disease Activity Score in 28 joints (DAS28) and Multidimensional Health Assessment Questionnaire (MD‐HAQ) scores were recorded during VA clinic visits, and respondent groups were compared.ResultsOf the 510 participants surveyed, 318 (62%) responded. Respondents were older (ages 69 versus 66 years; P = 0.006), more likely nonsmokers (80% versus 67%; P = 0.001), and had lower disease activity (DAS28 3.3 versus 3.8; P < 0.001, MD‐HAQ 0.8 versus 0.9; P = 0.01) than nonrespondents (n = 192 [38%]). The respondents with a non‐VA provider (n = 130 [41%]) were older (71 versus 68 years; P = 0.001) and had more education (14 versus 13 years; P = 0.021) than nondual‐care users. Only 6% of respondents reported having a non‐VA rheumatologist, with 2% receiving a non‐VA prescribed biologic agent or disease‐modifying antirheumatic drug.ConclusionIn this study, VA beneficiaries with RA had lower dual‐care utilization than previously reported for the general VA population, with few patients receiving dual rheumatology care or non‐VA RA medications. This survey suggests that most US veterans with RA who access VA care use the VA as their primary source of arthritis care.
Eight‐Year Retention Rate of First‐Line Tumor Necrosis Factor Inhibitors in Spondyloarthritis: A Multicenter Retrospective Analysis
Authors: Favalli Ennio Giulio , Selmi Carlo , Becciolini Andrea , Biggioggero Martina , Ariani Alarico , Santilli Daniele , Fusaro Enrico , Parisi Simone , Massarotti Marco , Marchesoni Antonio , Meroni Pier Luigi 
Published: October 2016

ObjectiveTo evaluate the 8‐year survival of the first tumor necrosis factor inhibitor (TNFi) in patients with axial spondyloarthritis (SpA) or psoriatic arthritis (PsA), identify the predictive factors for withdrawal, and compare the discontinuation rates for infliximab, etanercept, and adalimumab.MethodsWe evaluated PsA and axial SpA patients treated with a first‐line TNFi between 2005 and 2015 at 4 Italian tertiary centers. Eight‐year drug survival was calculated by the Kaplan‐Meier method, and risk for discontinuation among treatment groups compared by stratified log‐rank test. Univariate and multivariate Cox proportional hazard models were developed to examine predictors of withdrawal.ResultsOf 614 patients (316 axial with SpA, 298 with PsA), 203 received adalimumab, 131 etanercept, and 280 infliximab, with similar frequencies in axial SpA and PsA subgroups. The cumulative 8‐year retention rate in the whole population was 55.1% (57.2% and 51.9% for axial SpA and PsA, respectively; P = not significant). No significant differences were observed in drug persistence among individual TNFi in either group. Male sex (hazard ratio [HR] 0.595 [95% confidence interval (95% CI) 0.405–0.875]; P = 0.008) and concomitant methotrexate use (HR 0.648 [95% CI 0.426–0.985]; P = 0.042) were associated with a lower risk of withdrawal in PsA. High baseline Bath Ankylosing Spondylitis Disease Activity Index (HR 0.9842 [95% CI 0.9708–0.9980]; P = 0.028) was associated with a lower risk of withdrawal in axial SpA. No difference was found in the comparative analysis of reasons for discontinuation between PsA and axial SpA.ConclusionWe reported that the real‐life 8‐year retention rate of the first TNFi in axial SpA and PsA is greater than 50%, with no significant differences between axial SpA and PsA, irrespective of the individual TNFi.
Mediating Effect of Changes in Hand Impairments on Hand Function in Patients With Rheumatoid Arthritis: Exploring the Mechanisms of an Effective Exercise Program
Authors: Hall Amanda M. , Copsey Bethan , Williams Mark , Srikesavan Cynthia , Lamb Sarah E. ,   on behalf of the Sarah Trial Team
Published: October 2016

ObjectiveTo determine whether the effect of the Strengthening and Stretching for Rheumatoid Arthritis of the Hand (SARAH) exercise program on hand function was mediated by changes in the proposed active ingredients: strength, dexterity, and/or range of motion.MethodsThe SARAH intervention included exercises hypothesized to improve potential mediators of grip strength, pinch strength, wrist flexion, wrist extension, finger flexion, finger extension, thumb opposition, and dexterity, which would theoretically improve self‐reported hand function. All variables were measured at baseline and at 4 and 12 months. Structural equation modeling was used to assess mediation on change in hand function via change in potential mediators.ResultsChange in grip strength partially mediated change in hand function. Grip strength mediated 19.4% (95% confidence interval 0.9%, 37.8%) of the treatment effect.ConclusionImprovements in grip strength at 4 months are likely to mediate improved hand function at 12 months. The role of joint mobility exercises is less clear and is likely influenced by the choice of measurement tools for both mobility and function outcomes. More robust measurements of wrist and hand mobility for patients with rheumatoid arthritis may be necessary to determine the relationship between this variable and self‐reported hand function. Using a large trial data set, we have demonstrated that techniques used to target grip strength are key active ingredients of the SARAH exercise program and mediate its effect.
Longitudinal Changes in Magnetic Resonance Imaging–Based Measures of Femorotibial Cartilage Thickness as a Function of Alignment and Obesity: Data From the Osteoarthritis Initiative
Authors: Moyer Rebecca , Wirth Wolfgang , Eckstein Felix 
Published: October 2016

ObjectiveTo investigate the interaction between malalignment and body mass index (BMI) on cartilage thickness change in patients with knee osteoarthritis (OA).MethodsFemorotibial cartilage thickness was measured from baseline to 2 years in 558 knees with radiographic OA. Cartilage thickness was determined in the central weight‐bearing medial femorotibial cartilage (cMFTC) and lateral (cLFTC) compartments. Femorotibial angle (FTA) was stratified into neutral, minor, and definite malalignment. BMI was stratified using World Health Organization classifications for normal, overweight, and obese. Multivariable linear regression models were used to investigate the interaction between alignment and BMI, adjusting for age, sex, and disease severity.ResultsThere was no significant interaction for continuous measures of alignment and BMI (P = 0.301 for cMFTC and P = 0.852 for cLFTC). Using BMI tertiles, the association between alignment and medial or lateral cartilage thickness loss was not moderated by BMI, despite a significant association of malalignment with greater cartilage thickness loss (P ≤ 0.005). Using FTA tertiles, the association between BMI and medial cartilage thickness loss was approximately 3 times greater in knees with definite malalignment (P = 0.149) and approximately 5 times greater in knees with minor malalignment (P = 0.006). Specifically, knees with minor varus significantly modified this relationship (P = 0.021).ConclusionMalalignment was significantly associated with cartilage thickness loss per degree increase in malalignment, but was not moderated by BMI. BMI was significantly associated with greater rates of medial cartilage thickness loss per unit increase in BMI but only in knees with minor varus malalignment. These findings have implications for better understanding patient subgroups and intervention strategies targeting risk factors for knee OA.
Reduction in Spinal Radiographic Progression in Ankylosing Spondylitis Patients Receiving Prolonged Treatment With Tumor Necrosis Factor Inhibitors
Authors: Maas Fiona , Arends Suzanne , Brouwer Elisabeth , Essers Ivette , van der Veer Eveline , Efde Monique , van Ooijen Peter M. A. , Wolf Rinze , Veeger Nic J. G. M. , Bootsma Hendrika , Wink Freke R. , Spoorenberg Anneke 
Published: October 2016

ObjectiveTo evaluate the course of spinal radiographic progression for up to 8 years of followup in a large cohort of ankylosing spondylitis (AS) patients treated with tumor necrosis factor (TNF) inhibitors.MethodsConsecutive patients from the Groningen Leeuwarden AS cohort starting TNF inhibitors between 2004 and 2012 were included. Baseline and biannual radiographs were randomized with radiographs of TNF‐naive AS patients and scored in chronologic order according to modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). The course of radiographic progression (linear or nonlinear) was investigated using generalized estimating equations. Primary analysis was performed in patients with complete data over 4, 6, and 8 years of followup. Sensitivity analysis was performed after single linear imputation of missing radiographic data and after adjusting for patient characteristics with possible influence on radiographic progression.ResultsAt baseline, median mSASSS of 210 included AS patients was 2.8 (interquartile range 0.0–12.0), mean ± SD mSASSS 10.0 ± 15.5. During the first 4 years, radiographic progression followed a linear course (estimated mean progression rate was 1.7 for 0–2 and 2–4 years). A deflection from a linear course was found in patients with complete and imputed data over 6 and 8 years. The estimated mean 2‐year progression rate reduced from 2.3 to 0.8 in patients with complete 8‐year data. The same pattern was found after adjustment for baseline mSASSS scores, presence of syndesmophytes, sex, HLA–B27 status, age, symptom duration, smoking duration, body mass index, disease activity, and nonsteroidal antiinflammatory drug use.ConclusionThis observational cohort study in AS patients receiving long‐term TNF inhibitors showed a reduction in spinal radiographic progression after more than 4 years of followup.
Seven‐Year Outcomes of the Silicone Arthroplasty in Rheumatoid Arthritis Prospective Cohort Study
Authors: Chung Kevin C. , Kotsis Sandra V. , Burns Patricia B. , Burke Frank D. , Wilgis E. F. Shaw , Fox David A. , Kim H. Myra 
Published: October 2016

ObjectiveRheumatoid arthritis (RA) causes destruction of the metacarpophalangeal (MCP) joints, leading to hand deformities, pain, and loss of function. This study prospectively assessed long‐term functional and health‐related quality‐of‐life outcomes in RA patients with severe deformity at the MCP joints.MethodsRA patients between ages 18 to 80 years with severe deformity at the MCP joints were referred to 1 of the 3 study sites. Subjects who elected to undergo silicone metacarpophalangeal joint arthroplasty (SMPA) while continuing with medical management were followed in the SMPA cohort. Subjects who elected to continue with medical management alone without surgery were followed in the non‐SMPA cohort. Objective measurements included grip and pinch strength as well as arc of motion, ulnar drift, and extensor lag of the MCP joints. Patient‐reported outcomes included the Michigan Hand Questionnaire (MHQ) and the Arthritis Impact Measurement Scales questionnaire. Radiographs of SMPA implants were assessed and graded as intact, deformed, or fractured.ResultsMHQ scores showed large improvements post‐SMPA, and baseline‐adjusted expected outcomes in the SMPA group were significantly better at year 7 in function, aesthetics, satisfaction, and overall score compared to non‐SMPA. SMPA subjects did not improve in grip or pinch strength, but achieved significant improvement and maintained the improvement long term in ulnar drift and extensor lag.ConclusionBenefits of the SMPA procedure are maintained over 7 years with low rates of implant fracture or deformity. Non‐SMPA patients remained stable in their hand function over the 7‐year study duration.
Association of Anti–Citrullinated Peptide Antibodies With Coronary Artery Calcification in Rheumatoid Arthritis
Authors: Geraldino‐Pardilla Laura , Giles Jon T. , Sokolove Jeremy , Zartoshti Afshin , Robinson William H. , Budoff Matthew , Detrano Robert , Bokhari Sabahat , Bathon Joan M. 
Published: October 2016

ObjectiveCitrullinated proteins have been found within atherosclerotic plaque. However, studies evaluating the association between anti–citrullinated protein antibodies (ACPAs) and imaging measures of atherosclerosis in patients with rheumatoid arthritis (RA) have been limited to seroreactive citrullinated fibrinogen or citrullinated vimentin and have rendered contradictory results. Therefore, our objective was to evaluate this association using an extended panel of ACPAs in a larger sample of RA patients without clinical cardiovascular disease (CVD).MethodsACPAs were identified using a custom Bio‐Plex bead assay in 270 patients from 2 independent RA cohorts without clinical CVD, with the first one consisting of 195 patients and the other of 75 patients. Coronary artery calcium (CAC) was assessed by computed tomography as a measure of coronary artery disease.ResultsHigh levels of anti–citrullinated histone H2B antibodies were strongly associated with higher CAC scores, compared with lower antibody levels (P = 0.001); this remained significant after adjustment for traditional CV and RA‐specific risk factors (P = 0.03). No association between levels of ACPAs and CAC progression at 3 years was seen (P = 0.09); however, the number of progressors was small (n = 92).ConclusionHigher levels of ACPAs targeting Cit‐histone H2B were associated with higher CAC scores when compared to lower antibody levels, suggesting a potential role for histone citrullination seroreactivity in atherosclerosis.