bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wet acid deposition in Chinese natural and agricultural ecosystems: Evidence from national‐scale monitoring
Authors: Yu Haili , He Nianpeng , Wang Qiufeng , Zhu Jianxing , Xu Li , Zhu Zhilin , Yu Guirui 
Published: August 2016

AbstractAcid deposition in precipitation has received widespread attention. However, it is necessary to monitor the acid deposition in Chinese agricultural and natural ecosystems because data derived from traditional urban/suburban observations might overestimate it to some extent. In this study, we continuously measured the acid deposition through precipitation (pH, sulfate (SO42−), and nitrate (NO3−)) in 43 field stations from 2009 to 2014 to explore the spatial patterns and the main influencing factors of acid deposition in Chinese agricultural and natural ecosystems. The results showed that the average precipitation pH at the 43 stations varied between 4.10 and 8.25 (average: 6.2) with nearly 20% of the observation sites being subjected to acid precipitation (pH < 5.6). The average deposition of SO42− and NO3− was 115.99 and 32.93 kg ha−1 yr−1, respectively. An apparent regional difference of acid deposition in Chinese agricultural and natural ecosystems was observed, which was most serious in south and central China and less serious in northwest China, Inner Mongolia, and Qinghai‐Tibet. The level of economic development and amount of precipitation could explain most of the spatial variations of pH, SO42−, and NO3− depositions. It is anticipated that acid deposition might increase further, although the current level of acid deposition in these Chinese agricultural and natural ecosystems was found to be less serious than projected from urban/suburban data. The control of energy consumption should be strengthened in future to prevent an increase of acid deposition in China.
Spatial and seasonal variabilities of the stable carbon isotope composition of soil CO2 concentration and flux in complex terrain
Authors: Liang Liyin L. , Riveros‐Iregui Diego A. , Risk David A. 
Published: August 2016

AbstractBiogeochemical processes driving the spatial variability of soil CO2 production and flux are well studied, but little is known about the variability in the spatial distribution of the stable carbon isotopes that make up soil CO2, particularly in complex terrain. Spatial differences in stable isotopes of soil CO2 could indicate fundamental differences in isotopic fractionation at the landscape level and may be useful to inform modeling of carbon cycling over large areas. We measured the spatial and seasonal variabilities of the δ13C of soil CO2 (δS) and the δ13C of soil CO2 flux (δP) in a subalpine forest ecosystem located in the Rocky Mountains of Montana. We found consistently more isotopically depleted values of δS and δP in low and wet areas of the landscape relative to steep and dry areas. Our results suggest that the spatial patterns of δS and δP are strongly mediated by soil water and soil respiration rate. More interestingly, our analysis revealed different temporal trends in δP across the landscape; in high landscape positions δP became more positive, whereas in low landscape positions δP became more negative with time. These trends might be the result of differential dynamics in the seasonality of soil moisture and its effects on soil CO2 production and flux. Our results suggest concomitant yet independent effects of water on physical (soil gas diffusivity) and biological (photosynthetic discrimination) processes that mediate δS and δP and are important when evaluating the δ13C of CO2 exchanged between soils and the atmosphere in complex terrain.
ENSO response to high‐latitude volcanic eruptions in the Northern Hemisphere: The role of the initial conditions
Authors: Pausata Francesco S. R. , Karamperidou Christina , Caballero Rodrigo , Battisti David S. 
Published: August 2016

AbstractA large ensemble of Earth System Model simulations is analyzed to show that high‐latitude Northern Hemisphere eruptions give rise to El Niño‐like anomalies in the winter following the eruption, the amplitude of which depends on the state of the tropical Pacific at the time of the eruption. The El Niño‐like anomalies are almost three times larger when the eruption occurs during an incipient La Niña or during a neutral state compared to an incipient El Niño. The differential response results from stronger atmosphere‐ocean coupling and extra‐tropical feedbacks during an incipient La Niña compared to El Niño. Differences in the response continue through the second and third years following the eruption. When the eruption happens in a year of an incipient El Niño, a large cold (La Niña‐like) anomaly develops in year 2; if the eruption occurs in a year of an incipient La Niña, no anomalies are simulated in year 2 and a La Niña‐like response appears in year 3. After the El Niño‐like anomaly in the first winter, the overall tendency of ENSO in the following 2 years is toward a La Niña state. Our results highlight the high sensitivity of tropical Pacific dynamics under volcanic forcing to the ENSO initial state and lay the groundwork for improved predictions of the global climatic response to high‐latitude volcanic eruptions.
Laboratory demonstration of slow rise to fast acceleration of arched magnetic flux ropes
Authors: Ha Bao N. , Bellan Paul M. 
Published: August 2016

AbstractWe demonstrate the slow rise to fast acceleration of an arched plasma‐filled magnetic flux rope. The flux rope expansion is inhibited by an externally applied customizable strapping field. When the strapping field is not too strong and not too weak, expansion forces build up while the flux rope is in the strapping field region. When the flux rope moves to a critical height beyond the peak strapping field region, the plasma accelerates quickly corresponding to the observed slow rise to fast acceleration of solar eruptions. This behavior is in agreement with the predictions of the torus instability.
Tectonic tremor on Vancouver Island, Cascadia, modulated by the body and surface waves of the Mw 8.6 and 8.2, 2012 East Indian Ocean earthquakes
Authors: Kundu Bhaskar , Ghosh Abhijit , Mendoza Manuel , Bürgmann Roland , Gahalaut V. K. , Saikia Dipankar 
Published: August 2016

AbstractThe 2012 East Indian Ocean earthquake (Mw 8.6), so far the largest intraoceanic plate strike‐slip event ever recorded, modulated tectonic tremors in the Cascadia subduction zone. The rate of tremor activity near Vancouver Island increased by about 1.5 times from its background level during the passage of seismic waves of this earthquake. In most cases of dynamic modulation, large‐amplitude and long‐period surface waves stimulate tremors. However, in this case even the small stress change caused by body waves generated by the 2012 earthquake modulated tremor activity. The tremor modulation continued during the passage of the surface waves, subsequent to which the tremor activity returned to background rates. Similar tremor modulation is observed during the passage of the teleseismic waves from the Mw 8.2 event, which occurs about 2 h later near the Mw 8.6 event. We show that dynamic stresses from back‐to‐back large teleseismic events can strongly influence tremor sources.
Acceleration of regional plate subduction beneath Kanto, Japan, after the 2011 Tohoku‐oki earthquake
Authors: Uchida Naoki , Asano Youichi , Hasegawa Akira 
Published: August 2016

AbstractTwo oceanic plates (the Pacific (PA) and Philippine Sea (PH)) subduct beneath the land plate, and they forms deeper (PH‐PA) and shallower (land‐PH) plate boundaries beneath Kanto. Remarkably enhanced seismicity was observed in the densely populated area after the 2011 Tohoku‐oki earthquake, which cannot simply be explained by the southern expansion of the postseismic slip of the earthquake. We examine interplate repeating earthquakes to constrain the relative plate motion across aseismically slipping faults. The repeater slip rates show creep rates in the deeper and shallower boundaries, respectively, increased to 2.4–6.6 times and 1.3–6.2 times the pre‐Tohoku‐oki rates. In addition, the repeater slip directions show no change larger than 4° in the deeper boundary. The interplate creep rates and slip directions suggest that regional movements of both the two plates had accelerated. They probably caused the seismicity increase, frequent slow slips on the shallower boundary, and enhanced probability of larger earthquakes.
Crustal structure of the Kermadec arc from MANGO seismic refraction profiles
Authors: Bassett Dan , Kopp Heidrun , Sutherland Rupert , Henrys Stuart , Watts Anthony B. , Timm Christian , Scherwath Martin , Grevemeyer Ingo , de Ronde Cornel E. J. 
Published: August 2016

AbstractThree active‐source seismic refraction profiles are integrated with morphological and potential field data to place the first regional constraints on the structure of the Kermadec subduction zone. These observations are used to test contrasting tectonic models for an along‐strike transition in margin structure previously known as the 32°S boundary. We use residual bathymetry to constrain the geometry of this boundary and propose the name Central Kermadec Discontinuity (CKD). North of the CKD, the buried Tonga Ridge occupies the fore‐arc with VP 6.5–7.3 km s−1 and residual free‐air gravity anomalies constrain its latitudinal extent (north of 30.5°S), width (110 ± 20 km), and strike (~005° south of 25°S). South of the CKD the fore‐arc is structurally homogeneous downdip with VP 5.7–7.3 km s−1. In the Havre Trough back‐arc, crustal thickness south of the CKD is 8–9 km, which is up to 4 km thinner than the northern Havre Trough and at least 1 km thinner than the southern Havre Trough. We suggest that the Eocene arc did not extend along the current length of the Tonga‐Kermadec trench. The Eocene arc was originally connected to the Three Kings Ridge, and the CKD was likely formed during separation and easterly translation of an Eocene arc substrate during the early Oligocene. We suggest that the first‐order crustal thickness variations along the Kermadec arc were inherited from before the Neogene and reflect Mesozoic crustal structure, the Cenozoic evolution of the Tonga‐Kermadec‐Hikurangi margin and along‐strike variations in the duration of arc volcanism.
The impacts of precipitating cloud radiative effects on ocean surface evaporation, precipitation, and ocean salinity in coupled GCM simulations
Authors: Li J.‐L. F. , Wang Yi‐Hui , Lee Tong , Waliser Duane , Lee Wei‐Liang , Yu Jia‐Yuh , Chen Yi‐Chun , Fetzer Eric , Hasson Audrey 
Published: August 2016

AbstractThe coupled global climate model (GCM) fidelity in representing upper ocean salinity including near sea surface bulk salinity (SSS) is evaluated in this study, with a focus on the Pacific Ocean. The systematic biases in ocean surface evaporation (E) minus precipitation (P) and SSS are found to be fairly similar in the twentieth century simulations of the Coupled Model Intercomparison Phase 3 (CMIP3) and Phase 5 (CMIP5) relative to the observations. One of the potential causes of the CMIP model biases is the missing representation of the radiative effects of precipitating hydrometeors (i.e., snow) in most CMIP models. To examine the radiative effect of cloud snow on SSS, sensitivity experiments with and without such effect are conducted by the National Center for Atmospheric Research‐coupled Community Earth System Model (CESM). This study investigates the difference in SSS between sensitivity experiments and its relationship with atmospheric circulation, E − P and air‐sea heat fluxes. It is found that the exclusion of the cloud snow radiative effect in CESM produces weaker Pacific trade winds, resulting in enhanced precipitation, reduced evaporation, and a reduction of the upper ocean salinity in the tropical and subtropical Pacific. The latter results in an improved comparison with climatological upper ocean bulk salinity. The introduction of cloud snow also altered the budget terms that maintain the time‐mean salinity in the mixed layer.
Observations of two sprite‐producing storms in Colorado
Authors: Lang Timothy J. , Lyons Walter A. , Cummer Steven A. , Fuchs Brody R. , Dolan Brenda , Rutledge Steven A. , Krehbiel Paul , Rison William , Stanley Mark , Ashcraft Thomas 
Published: August 2016

AbstractTwo sprite‐producing thunderstorms were observed on 8 and 25 June 2012 in northeastern Colorado by a combination of low‐light cameras, a lightning mapping array, polarimetric and Doppler radars, the National Lightning Detection Network, and charge moment change measurements. The 8 June event evolved from a tornadic hailstorm to a larger multicellular system that produced 21 observed positive sprites in 2 h. The majority of sprites occurred during a lull in convective strength, as measured by total flash rate, flash energy, and radar echo volume. Mean flash area spiked multiple times during this period; however, total flash rates still exceeded 60 min−1, and portions of the storm featured a complex anomalous charge structure, with midlevel positive charge near −20°C. The storm produced predominantly positive cloud‐to‐ground lightning. All sprite‐parent flashes occurred on the northeastern flank of the storm, where strong westerly upper level flow was consistent with advection of charged precipitation away from convection, providing a pathway for stratiform lightning. The 25 June event was another multicellular hailstorm with an anomalous charge structure that produced 26 positive sprites in less than 1 h. The sprites again occurred during a convective lull, with relatively weaker reflectivity and lower total flash rate but relatively larger mean flash area. However, all sprite parents occurred in or near convection and tapped charge layers in adjacent anvil cloud. The results demonstrate the sprite production by convective ground strokes in anomalously charged storms and also indicate that sprite production and convective vigor are inversely related in mature storms.
Snow‐covered soils produce N2O that is lost from forested catchments
Authors: Enanga E. M. , Creed I. F. , Fairweather T. , Casson N. J. 
Published: August 2016

AbstractThe magnitude of net soil nitrous oxide (N2O) production from a snow‐covered catchment in a northern temperate forest was investigated. There was considerable net soil N2O‐N production and consumption through the snowpack, ranging from −6.6 to 26.2 g‐N ha−1 d−1. There was no difference in net N2O production among topographic positions despite significant variation in soil moisture, reduction‐oxidation conditions, and pore water dissolved organic carbon and nitrate. Soil temperatures did not vary among topographic positions, suggesting that temperatures at or above the freezing point allow N2O production to proceed under the snowpack. Redox conditions were lower at wetland positions compared to lowlands and uplands, suggesting that the biogeochemical pathway of N2O production varies with topography. Over the entire nongrowing season, 1.5 kg of N2O‐N was exported to the atmosphere from the 6.33 ha catchment, representing 31% of the growing season N2O‐N production. These results suggest that winter is an active time for gaseous N production in these forests and that N2O production under the snowpack represents an often unmonitored flux of N from catchments.
Knee Extensor Strength and Risk of Structural, Symptomatic, and Functional Decline in Knee Osteoarthritis: A Systematic Review and Meta‐Analysis
Authors: Culvenor Adam G. , Ruhdorfer Anja , Juhl Carsten , Eckstein Felix , Øiestad Britt Elin 
Published: August 2016

ObjectiveTo perform a systematic review and meta‐analysis on the association between knee extensor strength and the risk of structural, symptomatic, or functional deterioration in individuals with or at risk of knee osteoarthritis (KOA).MethodsWe systematically identified and methodologically appraised all longitudinal studies (≥1‐year followup) reporting an association between knee extensor strength and structural (tibiofemoral, patellofemoral), symptomatic (self‐reported, knee replacement), or functional (subjective, objective) decline in individuals with or at risk of radiographic or symptomatic KOA. Results were pooled for each of the above associations using meta‐analysis, or if necessary, summarized according to a best‐evidence synthesis.ResultsFifteen studies were included, evaluating >8,000 participants (51% female), with a followup time between 1.5 and 8 years. Meta‐analysis revealed that lower knee extensor strength was associated with an increased risk of symptomatic (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] pain: odds ratio [OR] 1.35, 95% confidence interval [95% CI] 1.10–1.67) and functional decline (WOMAC function: OR 1.38, 95% CI 1.00–1.89, and chair‐stand task: OR 1.03, 95% CI 1.03–1.04), but not increased risk of radiographic tibiofemoral joint space narrowing (JSN) (OR 1.15, 95% CI 0.84–1.56). No trend in risk was observed for KOA status (present versus absent). Best‐evidence synthesis showed inconclusive evidence for lower knee extensor strength being associated with increased risk of patellofemoral deterioration.ConclusionMeta‐analysis showed that lower knee extensor strength is associated with an increased risk of symptomatic and functional deterioration, but not tibiofemoral JSN. The risk of patellofemoral deterioration in the presence of knee extensor strength deficits is inconclusive.
Trends in Gout and Rheumatoid Arthritis Hospitalizations in Canada From 2000 to 2011
Authors: Rai Sharan K. , Aviña‐Zubieta J. Antonio , McCormick Natalie , De Vera Mary A. , Lacaille Diane , Sayre Eric C. , Choi Hyon K. 
Published: August 2016

ObjectiveGout and rheumatoid arthritis (RA) are the 2 most common forms of inflammatory arthritis worldwide. As hospitalizations for both conditions lead to substantial health resource use, contemporary inpatient trends and associated costs may provide important benchmarks of disease burden. However, relevant data are limited.MethodsWe used PopulationData BC, a population‐based administrative data set from Canada. We examined trends in the annual hospitalization and surgery rate of gout and RA from 2000 to 2011. Additionally, we examined annual trends in the inpatient cost burden of both conditions. We assessed annual trends in hospitalization and surgery rates using Poisson regression models and cost trends using linear regression models.ResultsFrom 2000 to 2011, the annual hospitalization rate for RA declined by 49% from 15.4 to 7.9 per 100,000 Canadian adults (P < 0.001), whereas that for gout doubled from 3.8 to 7.6 per 100,000 Canadian adults (P < 0.001). Approximately 31% of RA admissions were associated with hip or knee replacement surgery; the trend of these surgeries paralleled the declining trend in RA hospitalizations (P = 0.0097). The inpatient costs also reflected the hospitalization trends, with a 40% decrease in RA hospital costs, while gout costs more than doubled over the study period.ConclusionOur findings indicate that hospitalization rates for gout have doubled over the past decade, while those for RA have decreased considerably. While these data provide an encouraging benchmark for RA care, they also highlight the critical need to improve gout management and prevention to mitigate its rising disease burden in Canada and beyond.
Efficacy of Tailored Exercise Therapy on Physical Functioning in Patients With Knee Osteoarthritis and Comorbidity: A Randomized Controlled Trial
Authors: de Rooij Mariëtte , van der Leeden Marike , Cheung John , van der Esch Martin , Häkkinen Arja , Haverkamp Daniël , Roorda Leo D. , Twisk Jos , Vollebregt Joke , Lems Willem F. , Dekker Joost 
Published: August 2016

ObjectiveTo evaluate the efficacy on physical functioning and safety of tailored exercise therapy in patients with knee osteoarthritis (OA) and comorbidities.MethodsIn a randomized controlled trial, 126 participants were included with a clinical diagnosis of knee OA and at least 1 of the following target comorbidities: coronary disease, heart failure, type 2 diabetes mellitus, chronic obstructive pulmonary disease, or obesity (body mass index ≥30 kg/m2), with severity score ≥2 on the Cumulative Illness Rating Scale. The intervention group received a 20‐week, individualized, comorbidity‐adapted exercise program consisting of aerobic and strength training and training of daily activities. The control group received their current medical care for knee OA and were placed on a waiting list for exercise therapy. Primary outcome measures were the Western Ontario and McMaster Universities Osteoarthritis Index, subscale physical functioning (WOMAC‐pf), and the 6‐minute walk test (6MWT). Measurements were performed at baseline, after 20 weeks (directly posttreatment), and at 3 months posttreatment.ResultsStatistically significant physical functioning differences over time were found between the intervention and control group (WOMAC: B = −7.43 [95% confidence interval (95% CI) −9.99, −4.87], P < 0.001; and 6MWT: B = 34.16 [95% CI 17.68, 50.64], P < 0.001) in favor of the intervention group. At 3 months followup, the mean improvements in the intervention group were 33% on the WOMAC scale and 15% on the 6MWT. These improvements are of clinical relevance. No serious adverse events occurred during the intervention.ConclusionThis is the first study showing that tailored exercise therapy is efficacious in improving physical functioning and safe in patients with knee OA and severe comorbidities.