bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluid‐faulting interactions: Fracture‐mesh and fault‐valve behavior in the February 2014 Mammoth Mountain, California, earthquake swarm
Authors: Shelly David R. , Taira Taka'aki , Prejean Stephanie G. , Hill David P. , Dreger Douglas S.
Published: June 2015

Faulting and fluid transport in the subsurface are highly coupled processes, which may manifest seismically as earthquake swarms. A swarm in February 2014 beneath densely monitored Mammoth Mountain, California, provides an opportunity to witness these interactions in high resolution. Toward this goal, we employ massive waveform‐correlation‐based event detection and relative relocation, which quadruples the swarm catalog to more than 6000 earthquakes and produces high‐precision locations even for very small events. The swarm's main seismic zone forms a distributed fracture mesh, with individual faults activated in short earthquake bursts. The largest event of the sequence,M3.1, apparently acted as a fault valve and was followed by a distinct wave of earthquakes propagating ~1 km westward from the updip edge of rupture, 1–2 h later. Late in the swarm, multiple small, shallower subsidiary faults activated with pronounced hypocenter migration, suggesting that a broader fluid pressure pulse propagated through the subsurface.
Significant modulation of variability and projected change in California winter precipitation by extratropical cyclone activity
Authors: Chang Edmund K. M. , Zheng Cheng , Lanigan Patrick , Yau Albert M. W. , Neelin J. David
Published: June 2015

Extratropical cyclones give rise to much of the precipitation over California. Observed California winter precipitation is highly correlated to a metric of extratropical cyclone activity over the Eastern Pacific. The lack of precipitation over the recent winters is coincident with consecutive winters of much below average cyclone activity. Analysis of variability in cyclone activity and California precipitation simulated by models participating in Coupled Model Intercomparison Project Phase 5 indicates that most models can simulate the relationship between cyclone activity and precipitation well. Examination of projected change suggests (1) no evidence of a long‐term downward trend in California region cyclone activity within the examined scenarios and (2) that the intermodel spread in California precipitation projection can be largely explained by the spread in the projection of extratropical cyclone activity. This highlights the need to further understand physical mechanisms for the variation in projection of cyclone activity in this region.
The seasonal cycle of the Arctic Ocean under climate change
Authors: Carton James A. , Ding Yanni , Arrigo Kevin R.
Published: June 2015

The seasonal cycle of Arctic Ocean temperature is weak due to the insulating and light‐scattering effects of sea ice cover and the moderating influence of the seasonal storage and release of heat through ice melting and freezing. The retreat of sea ice and other changes in recent decades is already warming surface air temperatures in winter. These meteorological changes raise the question of how the seasonal cycle of the ocean may change. Here we present results from coupled climate model simulations showing that the loss of sea ice will dramatically increase the amplitude of the seasonal cycle of sea surface temperature in the Arctic Ocean. Depending on the rate of growth of atmospheric greenhouse gases, the seasonal range in Arctic sea surface temperature may exceed 10°C by year 2300, greatly increasing the stratification of the summer mixed layer.
Effect of local variability in erosional resistance on large‐scale morphodynamic response of salt marshes to wind waves and extreme events
Authors: Leonardi Nicoletta , Fagherazzi Sergio
Published: June 2015

We use field data and a cellular automata model to investigate salt marsh response to wave action under different wave energy conditions and frequency of extreme events. Our results suggest that salt marsh response to wind waves is tied to their local properties. In case of low‐wave‐energy conditions, local variability in marsh resistance might lead to the unpredictable failure of large marsh portions with respect to average erosion rates. High‐wave‐energy conditions, while overall leading to faster marsh deterioration, produce constant and predictable erosion rates. A high occurrence of extreme events leads to smoother and more uniformly deteriorating marsh boundary profiles. Salt marshes subject to weak wave energy conditions are the most susceptible to variations in the frequency of extreme events. This suggests that variations in time in the morphology of salt marsh boundaries could be used to infer changes in frequency and magnitude of external agents.
The impact of sea surface temperature bias on equatorial Atlantic interannual variability in partially coupled model experiments
Authors: Ding Hui , Greatbatch Richard J. , Latif Mojib , Park Wonsun
Published: June 2015

We examine the impact of sea surface temperature (SST) bias on interannual variability during boreal summer over the equatorial Atlantic using two suites of partially coupled model (PCM) experiments with and without surface heat flux correction. In the experiments, surface wind stress anomalies are specified from observations while the thermodynamic coupling between the atmospheric and oceanic components is still active as in the fully coupled model. The results show that the PCM can capture around 50% of the observed variability associated with the Atlantic Niño from 1958 to 2013, but only when the bias is substantially reduced using heat flux correction, with no skill otherwise. We further show that ocean dynamics explain a large part of the SST variability in the eastern equatorial Atlantic in both observations (50–60%) and the PCM experiments (50–70%) with heat flux correction, implying that the seasonal predictability potential may be higher than currently thought.
Thermospheric poleward wind surge at midlatitudes during great storm intervals
Authors: Zhang Shun‐Rong , Erickson Philip J. , Foster John C. , Holt John M. , Coster Anthea J. , Makela Jonathan J. , Noto John , Meriwether John W. , Harding Brian J. , Riccobono Juanita , Kerr Robert B.
Published: June 2015

We report a significant poleward surge in thermospheric winds at subauroral and midlatitudes following the 17–18 March 2015 great geomagnetic storm. This premidnight surge is preceded by strong westward winds. These disturbances were observed over three sites with geodetic latitudes 35–42°N in the American sector by Fabry‐Perot interferometers at 630 nm wavelength. Prior to the wind disturbances, subauroral polarization streams (SAPS) were measured by the Millstone Hill incoherent scatter radar between 20 and 02 UT. We identify the observed neutral wind variations as driven by SAPS, through a scenario where strong ion flows cause a westward neutral wind, subsequently establishing a poleward wind surge due to the poleward Coriolis force on that westward wind. These regional disturbances appear to have prevented the well‐known storm time equatorward wind surge from propagating into low latitudes, with the consequence that the classic disturbance dynamo mechanism failed to occur.
A case study of electron precipitation fluxes due to plasmaspheric hiss
Authors: Hardman Rachael , Clilverd Mark A. , Rodger Craig J. , Brundell James B. , Duthie Roger , Holzworth Robert H. , Mann Ian R. , Milling David K. , Macusova Eva
Published: June 2015

We find that during a large geomagnetic storm in October 2011 the trapped fluxes of >30, >100, and >300 keV outer radiation belt electrons were enhanced at L = 3–4 during the storm main phase. A gradual decay of the trapped fluxes was observed over the following 5–7 days, even though no significant precipitation fluxes could be observed in the Polar Orbiting Environmental Satellite (POES) electron precipitation detectors. We use the Antarctic‐Arctic Radiation‐belt (Dynamic) Deposition–VLF Atmospheric Research Konsortium receiver network to investigate the characteristics of the electron precipitation throughout the storm period. Weak electron precipitation was observed on the dayside for 5–7 days, consistent with being driven by plasmaspheric hiss. Using a previously published plasmaspheric hiss‐induced electron energy e‐folding spectrum of E0 = 365 keV, the observed radio wave perturbation levels at L = 3–4 were found to be caused by >30 keV electron precipitation with flux ~100 el cm−2 s−1 sr−1. The low levels of precipitation explain the lack of response of the POES telescopes to the flux, because of the effect of the POES lower sensitivity limit and ability to measure weak diffusion‐driven precipitation. The detection of dayside, inner plasmasphere electron precipitation during the recovery phase of the storm is consistent with plasmaspheric hiss wave‐particle interactions and shows that the waves can be a significant influence on the evolution of the outer radiation belt trapped flux that resides inside the plasmapause.
Do eddies ride on Rossby waves?
Authors: Polito Paulo S. , Sato Olga T.
Published: June 2015

Both vortices and baroclinic Rossby waves show up as westward‐propagating features in the sea surface height anomaly (SSHA) records when displayed in the form of zonal‐temporal or Hovmöller diagrams. A chain of filters was used to separate the SSHA into orthogonal components. Each of the filtered components was then reassembled as a set of maps. In the maps of individual components, we clearly see westward propagating Rossby waves. Our most striking findings are: (i) limited within their critical latitudes, the wave extrema coincide with a significant number of vortices; (ii) eddy‐wave coincidence occurs at a preferred latitude that depends on the wave period; (iii) among the vortices that, at some point of their existence coincide with a wave, a relatively large percentage of them remained their whole lifetime with the wave, and (iv) a mechanism is proposed to explain why eddies tend to remain over the wave extrema (crests and troughs). Our answer to the title question is: yes, they often do.
Anisotropic internal thermal stress in sea ice from the Canadian Arctic Archipelago
Authors: Hata Y. , Tremblay L. B.
Published: June 2015

Results from an ice stress buoy deployed near the center of a multi‐year floe in the Viscount Melville Sound of the Canadian Arctic Archipelago between 10 October 2010 and 17 August 2011 are presented. The position record indicates the landlocked season was approximately 5 months, from 18 January to 22 June, when the sea ice was fast to Melville Island and Victoria Island. Thermal stresses (ranging from −84 to 66 kPa) dominate the internal stress record, with only a few dynamic stress events (∼50 kPa) recorded before the landlocked season. Intriguingly, the thermal stresses are isotropic before the landlocked ice onset and anisotropic during the landlocked season. Two possible causes to explain anisotropy in thermal stresses are considered: preferred c axis alignment of the ice crystal, and land confinement associated with the nearby coastline. The orientation of the principal stresses indicates that land confinement is responsible for the anisotropy. The stress record also clearly shows the presence of residual compressive stresses at the melt onset, suggesting a viscous creep relaxation time constant of several days. Finally, results show an interesting reversal in the sign of the correlation (from negative to positive) between surface air temperature and thermal stress after the onset of surface melt. We attribute this to the onset of water infiltration within sea ice after which colder night temperature leads to refreezing and compressive stresses. To the best of the authors' knowledge, this is the first time that anisotropic thermal stresses have been reported in sea ice.
Environmental controls of marine productivity hot spots around Antarctica
Authors: Arrigo Kevin R. , van Dijken Gert L. , Strong Aaron L.
Published: June 2015

Antarctic coastal polynyas are biologically rich ecosystems that support large populations of mammals and birds and are globally significant sinks of atmospheric carbon dioxide. To support local phytoplankton blooms, these highly productive ecosystems require a large input of iron (Fe), the sources of which are poorly known. Here we assess the relative importance of six different environmental factors in controlling the amount of phytoplankton biomass and rates of net primary production (NPP) in 46 coastal polynyas around Antarctica. Data presented here suggest that melting ice shelves are a primary supplier of Fe to coastal polynyas, with basal melt rates explaining 59% of the between‐polynya variance in mean chlorophyll a (Chl a) concentration. In a multiple regression analysis, which explained 78% of the variance in chlorophyll a (Chl a) between polynyas, basal melt rate explained twice as much of the variance as the next most important variable. Fe upwelled from sediments, which is partly controlled by continental shelf width, was also important in some polynyas. Of secondary importance to phytoplankton abundance and NPP were sea surface temperature and polynya size. Surprisingly, differences in light availability and the length of the open water season explained little or none of the variance in either Chl a or NPP between polynyas. If the productivity of coastal polynyas is indeed sensitive to the release of Fe from melting ice shelves, future changes in ice shelf melt rates could dramatically influence Antarctic coastal ecosystems and the ability of continental shelf waters to sequester atmospheric carbon dioxide.
When does the lightning attachment process actually begin?
Authors: Tran M. D. , Rakov V. A.
Published: June 2015

High‐speed video and electric field records of 43 first and 7 new‐ground‐termination subsequent strokes in negative lightning flashes, obtained at the Lightning Observatory in Gainesville, Florida, were examined. Eighteen (36%) of these strokes exhibited faintly luminous formations (FLFs) below the downward leader tip just prior to the return stroke. All the 18 FLFs were connected to the strike object on the ground, with 14 of them being also in contact with the downward leader tip. For 11 located events showing FLFs in contact with the downward leader tip, the FLF 2‐D length ranged from 51 to 200 m and the time interval between the end of exposure of the FLF frame and the return stroke onset ranged from 42 to 106 μs. We inferred that the FLFs mostly consisted of relatively low conductivity streamers, based on the following observations and estimates. (a) The rates at which the 11 FLFs were replaced by channels capable of guiding return stroke waves ranged from 0.7 × 106 m/s to 2.2 × 106 m/s, which is comparable to leader speeds in virgin air (in the same records). (b) The overwhelming majority of downward leaders continued stepping while being connected to ground via FLFs. (c) The average electric field along FLFs is 1 to 2 orders of magnitude higher than expected for hot, leader‐like channels. Since in all cases the FLF determined the strike point, we conclude that its inferred initiation up to a few hundreds of microseconds before the return stroke onset signified the beginning of the lightning attachment process.
Ventilation time scales of the North Atlantic subtropical cell revealed by coral radiocarbon from the Cape Verde Islands
Authors: Fernandez Alvaro , Lapen Thomas J. , Andreasen Rasmus , Swart Peter K. , White Christopher D. , Rosenheim Brad E.
Published: June 2015

We present coral‐ and sclerosponge‐based reconstructions of the 14C content in North Atlantic dissolved inorganic carbon (DIC) during the last ~100 years from the subtropical cells (STCs). These waters are sensitive to the dynamics of the shallow overturning meridional circulation that transports heat and water masses from the subtropics to the tropics. We use these records to investigate the circulation patterns of the off‐equatorial upwelling regions of the STCs, which are not well understood. Coral and sclerosponge skeletons provide long time series of ocean DIC 14C content, a tracer of oceanic circulation, effectively extending the observational record back in time. Sclerosponge data from the Bahamas were used to extend the existing subtropical 14C time series to the 21st century. Coral 14C data from the Cape Verde Islands (1890–2002) captured the 14C signature of water brought to the surface in the off‐equatorial regions of the STC present near the West African coast. We observe a unique postbomb trend at Cape Verde that is similar to the upwelling regions in the Pacific, and we interpret this trend as the result of the slow penetration of bomb 14C into the interior ocean as part of the STC circulation. Using a multibox mixing model we constrain the time history of bomb 14C in the eastern tropical Atlantic, and we estimate a 20 year time scale for ventilation of the thermocline in this area of the ocean. The similarity between the Atlantic and Pacific 14C‐based records of upwelling suggests that both are caused by bomb 14C penetration rather than more complex explanations that invoke changes in thermocline depth (e.g., related to El Niño–Southern Oscillation variability) or changes in the strength of the subtropical cells. Our results offer constraints for models of tropical ocean circulation and anthropogenic CO2 uptake that attempt to reproduce the characteristics of the shallow wind‐driven circulation in the Atlantic.
Suppressed convective rainfall by agricultural expansion in southeastern Burkina Faso
Authors: Mande Theophile , Ceperley Natalie C. , Katul Gabriel G. , Tyler Scott W. , Yacouba Hamma , Parlange Marc B.
Published: June 2015

With the “green economy” being promoted as a path to sustainable development and food security within the African continent, the influx of agricultural land is proliferating at a rapid pace often replacing natural savannah forests. Where agriculture is primarily rainfed, the possible adverse impacts of agricultural land influx on rainfall occurrences in water‐limited areas such as West Africa warrant attention. Using field observations complemented by model calculations in southeastern Burkina Faso, the main causes of a 10–30% suppressed daytime rainfall recorded over agricultural fields when referenced to natural savannah forests are examined. Measurements and model runs reveal that the crossing of the mixed layer height and lifting condensation levels, a necessary condition for cloud formation and subsequent rainfall occurrence, was 30% more frequent above the natural savannah forest. This increase in crossing statistics was primarily explained by increases in measured sensible heat flux above the savannah forest rather than differences in lifting condensation heights.
Medication Nonadherence Is Associated With Increased Subsequent Acute Care Utilization Among Medicaid Beneficiaries With Systemic Lupus Erythematosus
Authors: Feldman Candace H. , Yazdany Jinoos , Guan Hongshu , Solomon Daniel H. , Costenbader Karen H.
Published: June 2015

Objective

We examined whether nonadherence to hydroxychloroquine (HCQ) or immunosuppressive medications (ISMs) was associated with higher subsequent acute care utilization among Medicaid beneficiaries with systemic lupus erythematosus (SLE).

Methods

We utilized US Medicaid data from 2000–2006 to identify adults ages 18–64 years with SLE who were new users of HCQ or ISMs. We defined the index date as receipt of HCQ or ISMs without use in the prior 6 months. We measured adherence using the medication possession ratio (MPR), the proportion of days covered by total days’ supply dispensed, for the 1‐year post‐index date. Our outcomes were all‐cause and SLE‐related emergency department (ED) visits and hospitalizations in the subsequent year. We used multivariable Poisson regression models to examine the association between nonadherence (MPR <80%) and acute care utilization, adjusting for sociodemographics and comorbidities.

Results

We identified 9,600 HCQ new users and 3,829 ISM new users with SLE. The mean ± SD MPR for HCQ was 47.8% ± 30.3% and for ISMs was 42.7% ± 30.7%. Seventy‐nine percent of HCQ users and 83% of ISM users were nonadherent (MPR <80%). In multivariable models, among HCQ users, the incidence rate ratio (IRR) of ED visits was 1.55 (95% confidence interval [95% CI] 1.43–1.69) and the IRR of hospitalizations was 1.37 (95% CI 1.25–1.50), comparing nonadherers to adherers. For ISM users, the IRR of ED visits was 1.64 (95% CI 1.42–1.89) and of hospitalizations was 1.67 (95% CI 1.41–1.96) for nonadherers versus adherers.

Conclusion

In this cohort, nonadherence to HCQ and ISMs was common and was associated with significantly higher subsequent acute care utilization.
Etanercept‐Methotrexate Combination Therapy Initiators Have Greater Adherence and Persistence Than Triple Therapy Initiators With Rheumatoid Arthritis
Authors: Bonafede Machaon , Johnson Barbara H. , Tang Derek H. , Shah Neel , Harrison David J. , Collier David H.
Published: June 2015

Objective

To estimate adherence and persistence with etanercept plus methotrexate (ETN‐MTX) combination therapy and MTX, hydroxychloroquine, and sulfasalazine triple therapy at 1 year following treatment initiation in adults with rheumatoid arthritis (RA).

Methods

This retrospective analysis used data from the Truven Health MarketScan Commercial and Medicare Supplemental databases from January 2009 to July 2013. Adherence was defined as having percentage of days covered >80% for all drugs within each regimen. Persistence was defined as no treatment gap >45 days for any drug and no addition or switching to other disease‐modifying antirheumatic drugs. Multiple logistic regression models were employed in the analyses to control for potential confounders.

Results

A total of 3,724 ETN‐MTX patients and 818 triple therapy patients were eligible. At 1 year, 27.9% who were taking ETN‐MTX and 18.2% using triple therapy were adherent to all agents in their regimen (P < 0.0001), and 29.4% who were taking ETN‐MTX and 23.2% using triple therapy were persistent (P < 0.001). After adjusting for confounders, ETN‐MTX patients had significantly greater odds of being adherent (odds ratio [OR] 1.79, 95% confidence interval [95% CI] 1.47–2.17) and persistent (OR 1.45, 95% CI 1.20–1.72) compared with patients using triple therapy.

Conclusion

Patients with RA initiating treatment with ETN‐MTX combination therapy demonstrated greater adherence and persistence at 1 year than patients initiating triple therapy.
Gene Expression Factor Analysis to Differentiate Pathways Linked to Fibromyalgia, Chronic Fatigue Syndrome, and Depression in a Diverse Patient Sample
Authors: Iacob Eli , Light Alan R. , Donaldson Gary W. , Okifuji Akiko , Hughen Ronald W. , White Andrea T. , Light Kathleen C.
Published: June 2015

Objective

To determine if independent candidate genes can be grouped into meaningful biologic factors, and whether these factors are associated with the diagnosis of chronic fatigue syndrome (CFS) and fibromyalgia syndrome (FMS), while controlling for comorbid depression, sex, and age.

Methods

We included leukocyte messenger RNA gene expression from a total of 261 individuals, including healthy controls (n = 61), patients with FMS only (n = 15), with CFS only (n = 33), with comorbid CFS and FMS (n = 79), and with medication‐resistant (n = 42) or medication‐responsive (n = 31) depression. We used exploratory factor analysis (EFA) on 34 candidate genes to determine factor scores and regression analysis to examine whether these factors were associated with specific diagnoses.

Results

EFA resulted in 4 independent factors with minimal overlap of genes between factors, explaining 51% of the variance. We labeled these factors by function as 1) purinergic and cellular modulators, 2) neuronal growth and immune function, 3) nociception and stress mediators, and 4) energy and mitochondrial function. Regression analysis predicting these biologic factors using FMS, CFS, depression severity, age, and sex revealed that greater expression in factors 1 and 3 was positively associated with CFS and negatively associated with depression severity (Quick Inventory for Depression Symptomatology score), but not associated with FMS.

Conclusion

Expression of candidate genes can be grouped into meaningful clusters, and CFS and depression are associated with the same 2 clusters, but in opposite directions, when controlling for comorbid FMS. Given high comorbid disease and interrelationships between biomarkers, EFA may help determine patient subgroups in this population based on gene expression.
Physician Preferences and Variations in Prescription of Biologic Drugs for Rheumatoid Arthritis: A Register‐Based Study of 4,010 Patients in Sweden
Authors: Kalkan Almina , Husberg Magnus , Hallert Eva , Roback Kerstin , Thyberg Ingrid , Skogh Thomas , Carlsson Per
Published: June 2015

Objective

The prescription of biologic drugs for rheumatoid arthritis (RA) patients has varied considerably across different regions. Previous studies have shown physician preferences to be an important determinant in the decision to select biologic disease‐modifying antirheumatic drugs (bDMARDs) rather than nonbiologic, synthetic DMARDs (sDMARDs) alone. The aim of this study was to test the hypothesis that physician preferences are an important determinant for prescribing bDMARDs for RA patients in Sweden.

Methods

Using data from the Swedish Rheumatology Quality Register, we identified 4,010 RA patients who were not prescribed bDMARDs during the period 2008–2012, but who, on at least 1 occasion, had an sDMARD prescription and changed treatment for the first time to either a new sDMARD or a bDMARD. Physician preference for the use of bDMARDs was calculated using data on each physician's prescriptions during the study period. The relationship between prescription of a bDMARD and physician preference, controlling for patient characteristics, disease activity, and the physician's local context was evaluated using multivariate logistic regression.

Results

When adjusting for patient characteristics, disease activity, and the physician's local context, physician preference was an important predictor for prescription of bDMARDs. Compared with patients of a physician in the lowest preference tertile, patients of physicians in the highest and middle tertiles had an odds ratio for receiving bDMARDs of 2.8 (95% confidence interval [95% CI] 2.13–3.68) and 1.28 (95% CI 1.05–1.57), respectively.

Conclusion

Physician preference is an important determinant for prescribing bDMARDs.
Annual Incidence of Knee Symptoms and Four Knee Osteoarthritis Outcomes in the Johnston County Osteoarthritis Project
Authors: Murphy Louise B. , Moss Susan , Do Barbara T. , Helmick Charles G. , Schwartz Todd A. , Barbour Kamil E. , Renner Jordan , Kalsbeek William , Jordan Joanne M.
Published: June 2015

Objective

To estimate annual incidence rates (IRs) of knee symptoms and 4 knee osteoarthritis (OA) outcomes (radiographic, symptomatic, severe radiographic, and severe symptomatic), overall and stratified by sociodemographic characteristics and knee OA risk factors.

Methods

We analyzed baseline (1991–1997) and first followup (1999–2003) data (n = 1,518) from the Johnston County Osteoarthritis Project. Participants were African American and white adults, ages ≥45 years, living in Johnston County, North Carolina, US. Knee symptoms were pain, aching, or stiffness on most days in a knee. Radiographic OA was Kellgren/Lawrence grade ≤2 (severe radiographic ≥3) in at least 1 knee. Symptomatic OA was defined as symptoms in a radiographically affected knee; severe symptomatic OA was defined as severe symptoms and severe radiographic OA.

Results

The median followup time was 5.5 years. Average annual IRs were 6% for symptoms, 3% for radiographic OA, 2% for symptomatic OA, 2% for severe radiographic OA, and 0.8% for severe symptomatic OA. Across outcomes, IRs were highest among those with the following baseline characteristics: age ≥75 years, obese, a history of knee injury, or an annual household income ≤$15,000.

Conclusion

The annual onset of knee symptoms and 4 OA outcomes in Johnston County was high. This may preview the future of knee OA in the US and underscores the urgency of clinical and public health collaborations that reduce risk factors for, and manage the impact of, these outcomes. Inexpensive, convenient, and proven strategies (e.g., physical activity, self‐management education courses) complement clinical care and can reduce pain and improve quality of life for people with arthritis.
Cause‐Specific Mortality in Male US Veterans With Rheumatoid Arthritis
Authors: England Bryant R. , Sayles Harlan , Michaud Kaleb , Caplan Liron , Davis Lisa A. , Cannon Grant W. , Sauer Brian C. , Solow Elizabeth B. , Reimold Andreas M. , Kerr Gail S. , Schwab Pascale , Baker Josh F. , Mikuls Ted R.
Published: June 2015

Objective

There has been limited investigation into cause‐specific mortality and the associated risk factors in men with rheumatoid arthritis (RA). We investigated all‐cause and cause‐specific mortality in men with RA, examining determinants of survival.

Methods

Men from a longitudinal RA registry were followed from enrollment until death or through 2013. Vital status and cause of death were determined using the National Death Index. Crude mortality rates and standardized mortality ratios (SMRs) were calculated for all‐cause, cardiovascular disease (CVD), cancer, and respiratory mortality. Associations with all‐cause and cause‐specific mortality were examined using multivariable Cox proportional hazards and competing‐risks regression.

Results

There were 1,652 men with RA and 332 deaths. The leading causes of death were CVD (31.6%; SMR 1.77 [95% confidence interval (95% CI) 1.46–2.14]), cancer (22.9%; SMR 1.50 [95% CI 1.20–1.89]), and respiratory disease (15.1%; SMR 2.90 [95% CI 2.20–3.83]). Factors associated with all‐cause mortality included older age, white race, smoking, low body weight, comorbidity, disease activity, and prednisone use. Rheumatoid factor concentration and nodules were associated with CVD mortality. There were no associations of methotrexate or biologic agent use with all‐cause or cause‐specific mortality.

Conclusion

Men in this RA cohort experienced increased all‐cause and cause‐specific mortality, with a 3‐fold risk of respiratory‐related deaths compared to age‐matched men in the general population. Further studies are needed in order to examine whether interventions targeting potentially modifiable correlates of mortality might lead to improved long‐term survival in men with RA.
Comparison of Care Provided in Practices With Nurse Practitioners and Physician Assistants Versus Subspecialist Physicians Only: A Cohort Study of Rheumatoid Arthritis
Authors: Solomon Daniel H. , Fraenkel Liana , Lu Bing , Brown Erika , Tsao Peter , Losina Elena , Katz Jeffrey N. , Bitton Asaf
Published: June 2015

Objective

The Affordable Care Act proposes wider use of nurse practitioners (NPs) and physician assistants (PAs), but little is known about outcomes of care provided by them in medical specialties. We compared the outcomes of care for patients with rheumatoid arthritis (RA) seen in practices with NPs or PAs and rheumatologists versus practices with rheumatologists only.

Methods

We enrolled 7 rheumatology practices in the US (4 with NPs or PAs and 3 without). RA disease activity (categorized as in remission, low, moderate, or high, using standardized measures) was abstracted from medical records from the most recent 2 years. We performed a repeated‐measures analysis using generalized linear regression to compare disease activity for visits to practices with NPs or PAs versus rheumatologist‐only practices, adjusting for disease duration, serologic status, RA treatments, and disease activity measures.

Results

Records from 301 patients, representing 1,982 visits, were reviewed. The patients’ mean age was 61 years and 77% were female. In the primary adjusted analysis, patients seen in practices with NPs or PAs were less likely to have higher disease activity (odds ratio 0.32, 95% confidence interval 0.17–0.60; P = 0.004) than those seen in rheumatologist‐only practices. However, there were no differences in the change in disease activity.

Conclusion

Patients seen in practices with NPs or PAs had lower RA disease activity over 2 years compared to those seen in rheumatologist‐only practices; no differences were observed in the change in disease activity between visits either within or between the different types of provider practice.
Mini‐Residency in Musculoskeletal Care: An Interprofessional, Mixed‐Methods Educational Initiative for Primary Care Providers
Authors: Battistone Michael J. , Barker Andrea M. , Lawrence Phillip , Grotzke Marissa P. , Cannon Grant W.
Published: June 2015

Objective

A structured educational effort to train primary care providers (PCPs) to perform joint injections has been projected to be cost effective. The US Department of Veterans Affairs (VA) is developing a national continuing professional development program to train PCPs in the evaluation and management of patients with common musculoskeletal conditions. The objective of this pilot project was to confirm initial projections of cost effectiveness and to inform further efforts to develop this program on a national scale.

Methods

The Salt Lake City VA served as the national hub for this pilot project. The initial phase included 19 providers, who participated in a weeklong mixed‐methods course. Evaluation was conducted by the VA Employee Education System. Assessments included anonymous surveys, structured telephone interviews, and a review of de‐identified procedure codes.

Results

The survey response rate was 100%, with uniformly positive results. All participants recommended the expansion of this program. The mean number of joint injections performed each month increased from 0.3 (precourse) to 3.5 (postcourse), congruent with prior analyses projecting program cost effectiveness.

Conclusion

The musculoskeletal mini‐residency is a well‐received program, with early evidence of cost effectiveness and impact aligned with course objectives. This pilot program is a foundation for efforts in the national dissemination of this initiative.
Epidemiology and Treatment of New‐Onset and Established Rheumatoid Arthritis in an Insured US Population
Authors: Crane Martin M. , Juneja Maneesh , Allen Jeffery , Kurrasch Regina H. , Chu Myron E. , Quattrocchi Emilia , Manson Stephanie C. , Chang David J.
Published: June 2015

Objective

To investigate the epidemiology and treatment of rheumatoid arthritis (RA) in a population broadly representative of employed adults in the US, using a retrospective cohort design.

Methods

Incident and prevalent RA cohorts were defined from a sample of 4.66 million adults with complete followup data from the period of January 2005 through September 2008 in the Pharmetrics medical claims database. Demographics, comorbidity, and medical therapies were summarized using descriptive statistics.

Results

Median duration in the database was 5.7 years. Age‐ and sex‐adjusted incidence in 2006 was 0.71 per 1,000 persons at risk (n = 3,992) and prevalence in 2005 was 0.63% (n = 30,530). Within 12 months after diagnosis, 65%, 64%, and 20% of the incident cohort had been prescribed corticosteroids, nonbiologic disease‐modifying antirheumatic drugs (DMARDs), and tumor necrosis factor (TNF) inhibitors, respectively. Median time to first anti‐TNF prescription was 6 months; 31% switched to a second drug and 15% to a third. An aggressive subcohort (11% of incident patients) received more DMARDs (83%) and TNF inhibitors (43%), and was more likely to switch. Twenty‐eight percent of incident patients received only symptomatic therapy over a minimum of 1.75 years of followup; these patients were older with more comorbidities and contraindications to methotrexate.

Conclusion

In this insured population‐based cohort, only two‐thirds of newly diagnosed RA patients were prescribed a DMARD in year 1 and 28% received no antirheumatic therapy. Although limited by lack of clinical information and by left‐censoring, administrative databases capture clinical practice and suggest that gaps exist in treatment options available to a significant number of patients.
Aging Processes in Ultrafine‐Grained Low‐Alloyed Bronzes Subjected to Equal Channel Angular Pressing
Authors: Dobatkin Sergey V. , Bochvar Natalia R. , Shangina Daria V.
Published: June 2015

The aging processes in Cu‐0.7% Cr, Cu‐0.9% Hf, and Cu‐0.7% Cr‐0.9% Hf alloys after equal channel angular pressing have been studied. ECAP leads to strong grain refinement (200 nm for Cu‐0.7% Cr‐0.9% Hf alloy). It was shown that the Cu5Hf particles are more efficient as strengthening phase than the particles of Cr‐based solid solution. Alloying with hafnium also improves the thermal stability of hardening and minimizes recrystallization processes at aging temperatures. Temperature‐time aging regimes of bronzes for achieving optimal combination of strength, ductility, and electrical conductivity were also determined. Ternary alloy after aging at 500 °C for 2.5 h has a tensile strength of 582 MPa, an elongation of 18%, and an electrical conductivity of 75% IACS.
Formation of Corrosion‐Resistant Thermal Diffusion Boride Coatings
Authors: Medvedovski Eugene
Published: June 2015

The corrosion related issues in oil production can be significantly reduced using the coatings based on the compounds from the metals of the IVb–VIb and VIII groups and the non‐metallic elements of the IIIa–Va groups with strong covalent bonds and high thermodynamic potentials. Iron boride‐based coatings with consolidated structures are successfully applied through the thermal diffusion process to protect large production components from steels and ferrous alloys. The principles of the thermal diffusion coating formation are reported. The Fe‐B‐based coatings successfully withstand high temperature – high pressure water steam contained H2S, CO + CO2, hydrocarbons, chlorides in simulating oil field conditions tested in the autoclave and in the pressurized Atlas cell, and in strong acidic environments.
Thermal Shock Study on Different Advanced Ceramics by Laser Irradiation in Different Media
Authors: Pulz Robert , Rehmer Birgit , Schneider Gerold A. , Skrotzki Birgit
Published: June 2015

The thermal shock behavior of three commercial‐advanced ceramics (SSiC, MgO–PSZ, Al2O3) is characterized in air and vacuum applying a laser thermal shock. The available testing system permits the reproducible setting of defined temperature profiles in thin disks and allows a heating‐up thermal shock in various media. Due to the accurate determination of the time‐ and space‐resolved temperature distribution, the local stress state can be calculated as a function of time. It is shown that the thermal shock strength is highest for SSiC and lowest in Al2O3 with MgO–PSZ in between. The approach presented in this work allows quantifying the stress state at failure in terms of tangential tensile stress. The investigated environment does not affect the thermal shock resistance under the studied experimental conditions.
Influence of Ti3SiC2Fiber Coating on Interface and Matrix Cracking in an SiC Fiber‐Reinforced Polymer‐Derived Ceramic
Authors: Filbert‐Demut Ina , Bei Guoping , Höschen Till , Riesch Johann , Travitzky Nahum , Greil Peter
Published: June 2015

The effect of Ti3SiC2coatings on the interfacial properties of SiC‐fiber reinforced FeSiCr/SiC‐filled polymethylsilsesquioxane‐derived ceramics was investigated. An electrophoretically deposited Ti3SiC2coating was prepared on the fiber/matrix interface. Interfacial parameters such as frictional sliding stress and fracture energy were derived from fiber push‐out tests and correlated to the thickness of the Ti3SiC2layer. Compared to uncoated fibers, the Ti3SiC2interlayer gives rise for a pronounced enhance of interface shear strength, coefficient of friction, and sliding strength but a reduced fracture energy. With increasing Ti3SiC2coating thickness, thermal mismatch‐induced residual compressive stresses at the fiber/matrix interface tend to decrease significantly.
Enhanced Photocurrent Generation in Graphene/Copper Phthalocyanine/Mg–Al‐Layered Double Hydroxide Layer‐by‐Layer Multilayers
Authors: Yang Qinzheng , Yang Jing , Jiang Fujiao , Zhao Huazhang
Published: June 2015

In the paper, we demonstrated the controlled fabrication of nanostructured graphene/copper phthalocyanine/layered double hydroxide (G/TSCuPc/LDH) films by layer‐by‐layer assembly. The G/TSCuPc/LDH‐modified electrodes exhibited remarkable photoelectric performance, and its light absorption and resistance were increased with the increase of the film thickness. The electroactivity of the film was enhanced by the incorporation of graphene into TSCuPc. The 20‐layer film electrode generated higher photocurrent than the G/TSCuPc electrode, suggesting orderly assembled phthalocyanine layer between LDH and graphene layers and the efficient charge separation and electron transfer in the novel system.
Bi‐Functional Mechanism in Degradation of Toxic Water Pollutants by Catalytic Amorphous Metals
Authors: Das Santanu , Garrison Seth , Mukherjee Sundeep
Published: June 2015

The authors report on the high catalytic activity and bi‐functional catalysis mechanism of amorphous metals in degrading AZO Dye, a toxic water pollutant and carcinogen. Aluminum‐based metallic glass was found to completely degrade AZO dye at room temperature without any toxic by‐products. The high catalytic activity originates from the simultaneous ionization of the transition metals, which act as electron donors for rapid degradation of AZO dye in an aqueous medium. The dye degradation rate and catalytic activity were characterized via UV–VIS absorption spectroscopy. The rate of dye degradation was significantly faster compared to state‐of‐the‐art zero valent iron. The dye degradation mechanism was studied using Raman and IR spectroscopy combined with X‐ray photoelectron spectroscopy.
Engineering Zeolitic‐Imidazolate Framework (ZIF) Thin Film Devices for Selective Detection of Volatile Organic Compounds
Authors: Tu Min , Wannapaiboon Suttipong , Khaletskaya Kira , Fischer Roland A.
Published: June 2015

Thin films of sodalite‐type zeolitic‐imidazolate frameworks (ZIFs, ZIF‐7, 8, 9, 67, 90, and ZIF‐65‐Zn) with different metal centers and functional moieties are fabricated on SiO2 coated quartz crystal microbalance (QCM) substrates using automatic program controlled repeated direct growth method. The repeated direct growth procedure manipulated here shows great applicability for rapid growth of uniform ZIF thin films with controllable thickness. The fabricated ZIF/QCM devices are used to detect vapor phase volatile organic compounds including alcohol/water, BTEX compounds (benzene, toluene, ethylbenzene and xylene isomers), and hexane isomers. The ZIF/QCM devices exhibit selective detection behavior upon exposure to these chemical vapors. The effects of ZIF pore size, limited pore diameter, surface functionality, and structural flexibility on the sensing performances of ZIF/QCM devices are systematically investigated, which would be beneficial for the practical application of ZIF sensors based on array‐sensing technology. Furthermore, the selective adsorption behavior suggests that these ZIF materials have great potentials in the applications of biofuel recovery and the separation of benzene/cyclohexane, xylene, and hexane isomers.
Aligned Carbon Nanotube–Based Flexible Gel Substrates for Engineering Biohybrid Tissue Actuators
Authors: Shin Su Ryon , Shin Courtney , Memic Adnan , Shadmehr Samaneh , Miscuglio Mario , Jung Hyun Young , Jung Sung Mi , Bae Hojae , Khademhosseini Ali , Tang Xiaowu (Shirley) , Dokmeci Mehmet R.
Published: June 2015

Muscle‐based biohybrid actuators have generated significant interest as the future of biorobotics but so far they move without having much control over their actuation behavior. Integration of microelectrodes into the backbone of these systems may enable guidance during their motion and allow precise control over these actuators with specific activation patterns. Here, this challenge is addressed by developing aligned carbon nanotube (CNT) forest microelectrode arrays and incorporating them into scaffolds for cell stimulation. Aligned CNTs are successfully embedded into flexible and biocompatible hydrogels exhibiting excellent anisotropic electrical conductivity. Bioactuators are then engineered by culturing cardiomyocytes on the CNT microelectrode‐integrated hydrogel constructs. The resulting cardiac tissue shows homogeneous cell organization with improved cell‐to‐cell coupling and maturation, which is directly related to the contractile force of muscle tissue. This centimeter‐scale bioactuator has excellent mechanical integrity, embedded microelectrodes, and is capable of spontaneous actuation behavior. Furthermore, it is demonstrated that a biohybrid machine can be controlled by an external electrical field provided by the integrated CNT microelectrode arrays. In addition, due to the anisotropic electrical conductivity of the electrodes provided by aligned CNTs, significantly different excitation thresholds are observed in different configurations such as the ones with electrical fields applied in directions parallel versus perpendicular to the CNT alignment.
Facile Single‐Precursor Synthesis and Surface Modification of Hafnium Oxide Nanoparticles for Nanocomposite γ‐Ray Scintillators
Authors: Liu Chao , Hajagos Tibor Jacob , Kishpaugh David , Jin Yunxia , Hu Wei , Chen Qi , Pei Qibing
Published: June 2015

Inorganic nanoparticles/polymer nanocomposites provide a low cost, high performance alternative for gamma scintillation. However, inorganic nanoparticles used thus far suffer from either moderate atomic numbers or low band gaps, limiting the gamma stopping power and photoelectron production in these systems. Here, a highly efficient, facile single‐precursor synthesis protocol is reported for hafnium oxide nanoparticles with an average diameter of 5 nm. The nanoparticle surface is further functionalized for the fabrication of highly transparent bulk‐size nanocomposite monoliths (2 mm thick, transmittance at 550 nm >75%) with nanoparticle loadings up to 40 wt% (net hafnium wt% up to 28.5%). Using poly(vinyltoluene) as the matrix, 2‐(4‐tert‐butylphenyl)‐5‐(4‐biphenylyl)‐1,3,4‐oxadiazole and 1,4‐bis(5‐phenyl‐2‐oxazolyl)benzene as the cascade fluors, and hafnium oxide nanoparticles as the gamma sensitizer, the nanocomposite monolith of 1 cm diameter and 2 mm thickness is fabricated capable of producing a full energy photopeak for 662 keV gamma rays, with the best deconvoluted photopeak energy resolution <8%.
Semi‐Egg‐Like Heterogeneous Compartmentalization of Cells Controlled by Contact Angle Hysteresis
Authors: Sun Kang , Liu Mingjie , Liu Hongliang , Zhang Pengchao , Fan Junbing , Meng Jingxin , Wang Shutao
Published: June 2015

Precise control of liquid inside compartments is critically important in bioreactors, combinatorial analysis, and tissue engineering. A contact angle hysteresis (CAH)‐based strategy is demonstrated to construct a semi‐egg‐like hydrogel architecture, leading to spatial heterogeneous compartmentalization of cells. The semi‐egg‐like architecture is fabricated by successively capturing and gelling prehydrogel liquids using a substrate with controlled‐CAH pattern and ultralow‐CAH background. The controlled‐CAH pattern could capture liquid with tunable size, while ultralow‐CAH background prevents liquid sticking. It is envisioned that this CAH‐based strategy would be promising in designing functional surface for engineering complicated architectures of either biomedical or nonbiomedical systems.