bluuebunny/crossref_metadata_2025_split huggingface dataset:
Watershed model calibration to the base flow recession curve with and without evapotranspiration effects
Authors: Jepsen S. M. , Harmon T. C. , Shi Y. 
Published: March 2016

AbstractCalibration of watershed models to the shape of the base flow recession curve is a way to capture the important relationship between groundwater discharge and subsurface water storage in a catchment. In some montane Mediterranean regions, such as the midelevation Providence Creek catchment in the southern Sierra Nevada of California (USA), nearly all base flow recession occurs after snowmelt, and during this time evapotranspiration (ET) usually exceeds base flow. We assess the accuracy to which watershed models can be calibrated to ET‐dominated base flow recession in Providence Creek, both in terms of fitting a discharge time‐series and realistically capturing the observed discharge‐storage relationship for the catchment. Model parameters estimated from calibrations to ET‐dominated recession are compared to parameters estimated from reference calibrations to base flow recession with ET‐effects removed (“potential recession”). We employ the Penn State Integrated Hydrologic Model (PIHM) for simulations of base flow and ET, and methods that are otherwise general in nature. In models calibrated to ET‐dominated recession, simulation errors in ET and the targeted relationship for recession (−dQ/dt versus Q) contribute substantially (up to 57% and 46%, respectively) to overestimates in the discharge‐storage differential, defined as d(lnQ)/dS, relative to that derived from water flux observations. These errors result in overestimates of deep‐subsurface hydraulic conductivity in models calibrated to ET‐dominated recession, by up to an order of magnitude, relative to reference calibrations to potential recession. These results illustrate a potential opportunity for improving model representation of discharge‐storage dynamics by calibrating to the shape of base flow recession after removing the complicating effects of ET.
Combining information from multiple flood projections in a hierarchical Bayesian framework
Authors: Le Vine Nataliya 
Published: March 2016

AbstractThis study demonstrates, in the context of flood frequency analysis, the potential of a recently proposed hierarchical Bayesian approach to combine information from multiple models. The approach explicitly accommodates shared multimodel discrepancy as well as the probabilistic nature of the flood estimates, and treats the available models as a sample from a hypothetical complete (but unobserved) set of models. The methodology is applied to flood estimates from multiple hydrological projections (the Future Flows Hydrology data set) for 135 catchments in the UK. The advantages of the approach are shown to be: (1) to ensure adequate “baseline” with which to compare future changes; (2) to reduce flood estimate uncertainty; (3) to maximize use of statistical information in circumstances where multiple weak predictions individually lack power, but collectively provide meaningful information; (4) to diminish the importance of model consistency when model biases are large; and (5) to explicitly consider the influence of the (model performance) stationarity assumption. Moreover, the analysis indicates that reducing shared model discrepancy is the key to further reduction of uncertainty in the flood frequency analysis. The findings are of value regarding how conclusions about changing exposure to flooding are drawn, and to flood frequency change attribution studies.
Toward improved prediction of the bedrock depth underneath hillslopes: Bayesian inference of the bottom‐up control hypothesis using high‐resolution topographic data
Authors: Gomes Guilherme J. C. , Vrugt Jasper A. , Vargas Eurípedes A. 
Published: March 2016

AbstractThe depth to bedrock controls a myriad of processes by influencing subsurface flow paths, erosion rates, soil moisture, and water uptake by plant roots. As hillslope interiors are very difficult and costly to illuminate and access, the topography of the bedrock surface is largely unknown. This essay is concerned with the prediction of spatial patterns in the depth to bedrock (DTB) using high‐resolution topographic data, numerical modeling, and Bayesian analysis. Our DTB model builds on the bottom‐up control on fresh‐bedrock topography hypothesis of Rempe and Dietrich (2014) and includes a mass movement and bedrock‐valley morphology term to extent the usefulness and general applicability of the model. We reconcile the DTB model with field observations using Bayesian analysis with the DREAM algorithm. We investigate explicitly the benefits of using spatially distributed parameter values to account implicitly, and in a relatively simple way, for rock mass heterogeneities that are very difficult, if not impossible, to characterize adequately in the field. We illustrate our method using an artificial data set of bedrock depth observations and then evaluate our DTB model with real‐world data collected at the Papagaio river basin in Rio de Janeiro, Brazil. Our results demonstrate that the DTB model predicts accurately the observed bedrock depth data. The posterior mean DTB simulation is shown to be in good agreement with the measured data. The posterior prediction uncertainty of the DTB model can be propagated forward through hydromechanical models to derive probabilistic estimates of factors of safety.
A laboratory study to estimate pore geometric parameters of sandstones using complex conductivity and nuclear magnetic resonance for permeability prediction
Authors: Osterman Gordon , Keating Kristina , Binley Andrew , Slater Lee 
Published: March 2016

AbstractWe estimate parameters from the Katz and Thompson permeability model using laboratory complex electrical conductivity (CC) and nuclear magnetic resonance (NMR) data to build permeability models parameterized with geophysical measurements. We use the Katz and Thompson model based on the characteristic hydraulic length scale, determined from mercury injection capillary pressure estimates of pore throat size, and the intrinsic formation factor, determined from multisalinity conductivity measurements, for this purpose. Two new permeability models are tested, one based on CC data and another that incorporates CC and NMR data. From measurements made on forty‐five sandstone cores collected from fifteen different formations, we evaluate how well the CC relaxation time and the NMR transverse relaxation times compare to the characteristic hydraulic length scale and how well the formation factor estimated from CC parameters compares to the intrinsic formation factor. We find: (1) the NMR transverse relaxation time models the characteristic hydraulic length scale more accurately than the CC relaxation time (
of 0.69 and 0.33 and normalized root mean square errors (NRMSE) of 0.16 and 0.21, respectively); (2) the CC estimated formation factor is well correlated with the intrinsic formation factor (NRMSE=0.23). We demonstrate that that permeability estimates from the joint‐NMR‐CC model (NRMSE=0.13) compare favorably to estimates from the Katz and Thompson model (NRMSE=0.074). This model advances the capability of the Katz and Thompson model by employing parameters measureable in the field giving it the potential to more accurately estimate permeability using geophysical measurements than are currently possible.
Weathering resistance of carbonate fault mirrors promotes rupture localization
Authors: Goldberg R. , Siman‐Tov S. , Emmanuel S. 
Published: March 2016

AbstractFractured rocks in fault zones regain their mechanical strength through a process called healing. A central pathway for healing involves the dissolution and reprecipitation of minerals in the fault zone which cements the fractured rocks during interseismic periods. However, some faults contain highly polished surfaces—coated in a thin nanoparticle layer—along which slip is localized. Crucially, these surfaces show little evidence of postseismic mineralization and healing. Here we use atomic force microscopy to show that naturally polished rocks from carbonate fault zones are resistant to dissolution, in stark contrast to the reactive minerals that make up the fault breccia. Our results suggest that the low reactivity of the nanoparticle layer could retard healing, helping to maintain the localization of the fault zone between seismic slip events. As fault localization affects seismic motion, the geochemical reactivity of fault mirrors could be an important control on seismicity along faults.
Electromagnetic disturbances observed near the dip region ahead of dipolarization front
Authors: Zhao D. , Fu S. Y. , Sun W. J. , Parks G. K. , Zong Q. G. , Shi Q. Q. , Pu Z. Y. , Cui Y. B. , Wu T. , Liu J. , Zhou X. Z. 
Published: March 2016

AbstractDipolarization front (DF) is a thin magnetic structure embedded in fast flows in the magnetotail, which plays an important role in particle acceleration, flow braking, wave excitation, and other related processes. Electromagnetic disturbances near the magnetic dip region in front of DFs are investigated using Time History of Events and Macroscale Interactions during Substorms probe observations in this paper. Strong magnetic field and electric field fluctuations, with several wave bands below and around the lower hybrid frequency, are found in an event on 21 March 2008. The properties of the wave are similar to that of magnetosonic wave. Detailed analyses show that the phase space density for ions in the perpendicular direction has a positive slope near the local Alfvén speed, which is a possible free‐energy source for the generation of the wave. This type of ion distribution could result from the earthward reflected ions ahead of DF, though other forming mechanism could not be fully ruled out.
Polar cap patches and the tongue of ionization: A survey of GPS TEC maps from 2009 to 2015
Authors: David Michael , Sojka J. J. , Schunk R. W. , Coster A. J. 
Published: March 2016

AbstractThe source and structuring mechanisms for F region density patches have been subjects of speculation and debate for many years. We have made a survey of mappings of total electron content (TEC) between the years 2009 and 2015 from the web‐based Madrigal data server in order to determine when patches and/or a tongue of ionization (TOI) have been present in the Northern Hemisphere polar cap; we find that there is a UT and seasonal dependence that follows a specific pattern. This finding sheds considerable light upon the old question of the source of polar cap patches, since it virtually eliminates potential patch plasma sources that do not have a UT/seasonal dependence, for example, particle precipitation or flux transfer events. We also find that the frequency of occurrence of patches or TOIs has little to do with the level of geomagnetic activity.
Global observational diagnosis of soil moisture control on the land surface energy balance
Authors: Gallego‐Elvira Belen , Taylor Christopher M. , Harris Phil P. , Ghent Darren , Veal Karen L. , Folwell Sonja S. 
Published: March 2016

AbstractAn understanding of where and how strongly the surface energy budget is constrained by soil moisture is hindered by a lack of large‐scale observations, and this contributes to uncertainty in climate models. Here we present a new approach combining satellite observations of land surface temperature and rainfall. We derive a Relative Warming Rate (RWR) diagnostic, which is a measure of how rapidly the land warms relative to the overlying atmosphere during 10 day dry spells. In our dry spell composites, 73% of the land surface between 60°S and 60°N warms faster than the atmosphere, indicating water‐stressed conditions, and increases in sensible heat. Higher RWRs are found for shorter vegetation and bare soil than for tall, deep‐rooted vegetation, due to differences in aerodynamic and hydrological properties. We show how the variation of RWR with antecedent rainfall helps to identify different evaporative regimes in the major nonpolar climate zones.
The dry season intensity as a key driver of NPP trends
Authors: Murray‐Tortarolo Guillermo , Friedlingstein Pierre , Sitch Stephen , Seneviratne Sonia I. , Fletcher Imogen , Mueller Brigitte , Greve Peter , Anav Alessandro , Liu Yi , Ahlström Anders , Huntingford Chris , Levis Sam , Levy Peter , Lomas Mark , Poulter Benjamin , Viovy Nicholas , Zaehle Sonke , Zeng Ning 
Published: March 2016

AbstractWe analyze the impacts of changing dry season length and intensity on vegetation productivity and biomass. Our results show a wetness asymmetry in dry ecosystems, with dry seasons becoming drier and wet seasons becoming wetter, likely caused by climate change. The increasingly intense dry seasons were consistently correlated with a decreasing trend in net primary productivity (NPP) and biomass from different products and could potentially mean a reduction of 10–13% in NPP by 2100. We found that annual NPP in dry ecosystems is particularly sensitive to the intensity of the dry season, whereas an increase in precipitation during the wet season has a smaller effect. We conclude that changes in water availability over the dry season affect vegetation throughout the whole year, driving changes in regional NPP. Moreover, these results suggest that usage of seasonal water fluxes is necessary to improve our understanding of the link between water availability and the land carbon cycle.
Exchangeable cation composition of the smectite‐rich plate boundary fault at the Japan Trench
Authors: Kameda Jun , Inaoi Chisaki , Conin Marianne 
Published: March 2016

AbstractTo better understand physicochemical processes in smectite‐rich fault zones, we examined exchangeable cation composition of samples from the slip zone of the 2011 Tohoku‐oki earthquake (Mw9.0) recovered by the Integrated Ocean Drilling Program Expedition 343. Our chemical analyses revealed that the exchangeable Ca2+ and Mg2+ are enriched in the slip zone, while Na+ is depleted. K+ shows a complicated depth profile probably due to K fixation. Based on fluid chemistry data, we estimated apparent selectivity coefficients of exchange reactions in the ternary Ca2+‐Mg2+‐Na+ system. The results suggest that the Na+ to Mg2+ exchange reaction on smectite might have progressed in the slip zone. One explanation for this feature is local progress of the reaction triggered by coseismic thermogenesis during the earthquake. Considering that the frictional property of smectite gouge is dependent on the exchangeable cation composition, chemical processes as observed in this study are intimately linked to physical aspect of smectite‐bearing faults.
Active Foot Synovitis in Patients With Rheumatoid Arthritis: Unstable Remission Status, Radiographic Progression, and Worse Functional Outcomes in Patients With Foot Synovitis in Apparent Remission
Authors: Wechalekar Mihir D. , Lester Susan , Hill Catherine L. , Lee Anita , Rischmueller Maureen , Smith Malcolm D. , Walker Jennifer G. , Proudman Susanna M. 
Published: March 2016

ObjectiveTo determine whether foot synovitis is associated with adverse radiographic and functional outcomes after 3 years in an inception rheumatoid arthritis (RA) cohort receiving treat‐to‐target combination disease‐modifying antirheumatic drug therapy.MethodsDisease activity was assessed in early RA patients (n = 266) using the Disease Activity Score in 28 joints, Clinical Disease Activity Index (CDAI), and Simplified Disease Activity Index (SDAI). Radiographic outcomes were assessed with annual hand and feet radiographs and quality of life with the Short Form 36 (SF‐36). The prevalence of remission and foot synovitis was calculated using marginal binomial generalized estimating equations, transition between remission and nonremission states by a multistate Markov model, and changes in radiographic scores by a negative binomial mixed regression log‐link model. Population‐matched SF‐36 data were analyzed by mixed‐effects linear regression.ResultsDisease activity scores that omit foot joints were modest in their ability to capture foot synovitis. Despite the relative stringency of the SDAI and CDAI for remission, 25–36% of patients in remission had foot synovitis. In patients in remission, foot synovitis predicted transition from remission into relapse by up to 2‐fold. The sustainability of remission markedly influenced the progression of erosion scores (P = 0.006). After adjusting for disease activity, foot synovitis was associated with worse SF‐36 physical functioning scores (P = 0.025).ConclusionDisease activity measures that omit foot joints capture foot synovitis poorly. When it is used to define remission, foot synovitis is found in a substantial proportion of patients, which predicts relapse and worse physical function. Foot synovitis influences the sustainability of remission, which in turn markedly influences radiographic progression. Regardless of remission status, persistent foot synovitis should prompt therapy escalation in order to improve long‐term outcomes.
Effect of Knee Extensor Strength on Incident Radiographic and Symptomatic Knee Osteoarthritis in Individuals With Meniscal Pathology: Data From the Multicenter Osteoarthritis Study
Authors: Thorlund Jonas B. , Felson David T. , Segal Neil A. , Nevitt Michael C. , Niu Jingbo , Neogi Tuhina , Lewis Cora E. , Guermazi Ali , Roemer Frank , Englund Martin 
Published: March 2016

ObjectiveHigh knee extensor strength may be important to protect against the development of knee osteoarthritis (OA) in populations at elevated risk, such as individuals with meniscal pathology. We investigated the extent to which high knee extensor muscle strength was associated with a decreased risk of developing radiographic or symptomatic knee OA in individuals with medial meniscal pathology.MethodsWe studied knees that at the baseline visit of the Multicenter Osteoarthritis Study had medial meniscal pathology but did not have radiographic knee OA (373 knees in 373 participants) or symptomatic knee OA (combination of radiographic knee OA and frequent knee symptoms; 531 knees in 531 participants). Isokinetic knee extensor strength was measured at baseline, and participants were followed for development of incident radiographic knee OA or incident symptomatic knee OA at 84 months. Separate binomial regression analyses with robust SEs adjusted for age, history of knee surgery, physical activity level, and clinic site were conducted for men and women.ResultsHigh knee extensor strength (normalized by allometric scaling) was associated with a reduced risk of radiographic knee OA in women (relative risk [RR] 0.52, 95% confidence interval [95% CI] 0.29–0.94) but not in men (RR 0.56, 95% CI 0.27–1.16). High knee extensor strength did not protect against the development of symptomatic knee OA, either in women or men.ConclusionThe results only partly confirm the hypothesis that high knee extensor muscle strength protects against later development of knee OA in individuals with medial meniscal pathology.
Epidemiology of Chronic Low Back Pain in US Adults: Data From the 2009–2010 National Health and Nutrition Examination Survey
Authors: Shmagel Anna , Foley Robert , Ibrahim Hassan 
Published: March 2016

ObjectiveTo describe the epidemiologic characteristics and associations with increased health care utilization in US adults with chronic low back pain (LBP).MethodsThe National Health and Nutrition Examination Survey 2009–2010 was administered to adults ages 20–69 years (n = 5,103). Chronic LBP was defined as pain in the area between the lower posterior margin of the rib cage and the horizontal gluteal fold, with a history of pain lasting almost every day for at least 3 months. Demographic and behavioral characteristics were compared between those with chronic LBP and those without. Factors associated with ≥10 health care visits per year were evaluated in the chronic LBP subgroup (n = 700).ResultsChronic LBP associations with adjusted odds ratios (ORadj) ≥2 included age 50–69 years, less than high school education, annual household income <$20,000, income from disability, depression, sleep disturbances, and medical comorbidities. Subjects with chronic LBP were more likely to be covered by government‐sponsored insurance plans (ORadj 3.23 [95% confidence interval (95% CI) 2.19–4.75] for Medicaid and ORadj 2.25 [95% CI 1.57–3.22] for Medicare; P < 0.0001), and visited health care providers more frequently (ORadj 3.35 [95% CI 2.40–4.67] for ≥10 health care visits in the past year; P < 0.0001). In the chronic LBP subgroup, adjusted ORs ≥2 were found for associations between ≥10 visits per year and unemployment, income from disability, depression, and sleep disturbances.ConclusionUS adults with chronic LBP are socioeconomically disadvantaged, make frequent health care visits, and are often covered by government‐sponsored health insurance. The clustering of behavioral, psychosocial, and medical issues should be considered in the care of Americans with chronic LBP.
Quality of Community‐Based Osteoarthritis Care: A Systematic Review and Meta‐Analysis
Authors: Hagen Kåre B. , Smedslund Geir , Østerås Nina , Jamtvedt Gro 
Published: March 2016

ObjectiveTo evaluate the state of quality of care for osteoarthritis (OA) by summarizing studies that have assessed the care provided to patients.MethodsA systematic review of community‐based observational studies of actual clinical practice treating people with OA compared with quality indicators (QIs) was performed. Four databases were searched from January 2000 to November 2015. Two reviewers independently determined study eligibility, assessed risk of bias, and extracted study data. The outcome was adherence to the QIs (pass rate). The overall pass rate (the total number of indicators passed divided by the total number of indicators for which the patients were eligible) was extracted from each study. When at least 50% of the studies had comparable individual QIs, the data were pooled with proportion meta‐analyses.ResultsFifteen studies comprising 16,103 patients were included, and the median overall pass rate across studies was 41% (range 22–65%). The pooled pass rates for individual QIs were “referral to orthopedic surgeon if no response to other therapy”: 59.4% (95% confidence interval [95% CI] 47.5–70.3); “paracetamol or acetaminophen first drug used”: 46.0% (95% CI 26.6–66.7); “assessed for pain and/or function”: 45.5% (95% CI 33.9–57.6); “referral or recommendation to exercise”: 38.7% (28.9–49.5); “offered education and self‐management”: 35.4% (95% CI 27.8–44.0); and “informed about potential risks if NSAIDs prescribed”: 34.1% (95% CI 24.7–44.9).ConclusionThere is room for improvement in community‐based OA care.
Tandem Copper‐Catalyzed N‐Arylation–Condensation and van Leusen Reaction: Synthesis of 1,4‐Benzodiazepines and Imidazobenzodiazepines (ImBDs)
Authors: Murugesh V. , Harish Battu , Adiseshu Minam , Babu Nanubolu Jagadeesh , Suresh Surisetti 
Published: March 2016

AbstractA straightforward, tandem, copper‐catalyzed N‐arylation–condensation has been developed using chiral cyclic 1,2‐diamines and ortho‐haloaryl aldehydes or ketones. The corresponding chiral tricyclic 1,4‐benzodiazepines were synthesized in high yields. Subsequently, the 1,4‐diazepines have been converted to a new class of tetracyclic N‐fused imidazobenzodiazepines (ImBDs) using the van Leusen reaction. A one‐pot sequential strategy has also been demonstrated for the synthesis of ImBDs. The synthetic utility of 1,4‐benzodiazepines and ImBDs is described.magnified image