bluuebunny/crossref_metadata_2025_split huggingface dataset:
Allometry of sexual size dimorphism in turtles: a comparison of mass and length data
Authors: Regis Koy W. , Meik Jesse M. 
Published: January 2017

BackgroundThe macroevolutionary pattern of Rensch’s Rule (positive allometry of sexual size dimorphism) has had mixed support in turtles. Using the largest carapace length dataset and only large-scale body mass dataset assembled for this group, we determine (a) whether turtles conform to Rensch’s Rule at the order, suborder, and family levels, and (b) whether inferences regarding allometry of sexual size dimorphism differ based on choice of body size metric used for analyses.MethodsWe compiled databases of mean body mass and carapace length for males and females for as many populations and species of turtles as possible. We then determined scaling relationships between males and females for average body mass and straight carapace length using traditional and phylogenetic comparative methods. We also used regression analyses to evalutate sex-specific differences in the variance explained by carapace length on body mass.ResultsUsing traditional (non-phylogenetic) analyses, body mass supports Rensch’s Rule, whereas straight carapace length supports isometry. Using phylogenetic independent contrasts, both body mass and straight carapace length support Rensch’s Rule with strong congruence between metrics. At the family level, support for Rensch’s Rule is more frequent when mass is used and in phylogenetic comparative analyses. Turtles do not differ in slopes of sex-specific mass-to-length regressions and more variance in body size within each sex is explained by mass than by carapace length.DiscussionTurtles display Rensch’s Rule overall and within families of Cryptodires, but not within Pleurodire families. Mass and length are strongly congruent with respect to Rensch’s Rule across turtles, and discrepancies are observed mostly at the family level (the level where Rensch’s Rule is most often evaluated). At macroevolutionary scales, the purported advantages of length measurements over weight are not supported in turtles.
Mobility and transport of mercury and methylmercury in peat as a function of changes in water table regime and plant functional groups
Authors: Haynes Kristine M. , Kane Evan S. , Potvin Lynette , Lilleskov Erik A. , Kolka Randall K. , Mitchell Carl P. J. 
Published: January 2017

AbstractClimate change is likely to significantly affect the hydrology, ecology, and ecosystem function of peatlands, with potentially important but unclear impacts on mercury mobility within and transport from peatlands. Using a full‐factorial mesocosm approach, we investigated the potential impacts on mercury mobility of water table regime changes (high and low) and vegetation community shifts (sedge‐dominated, Ericaceae‐dominated, or unmanipulated control) in peat monoliths at the PEATcosm mesocosm facility in Houghton, Michigan. Lower and more variable water table regimes and the loss of Ericaceae shrubs act significantly and independently to increase both total Hg and methylmercury concentrations in peat pore water and in spring snowmelt runoff. These differences are related to enhanced peat decomposition and internal regeneration of electron acceptors which are more strongly related to water table regime than to plant community changes. Loss of Ericaceae shrubs and an increase in sedge cover may also affect Hg concentrations and mobility via oxygen shuttling and/or the provision of labile root exudates. Altered hydrological regimes and shifting vegetation communities, as a result of global climate change, are likely to enhance Hg transport from peatlands to downstream aquatic ecosystems.
EMIC wave scale size in the inner magnetosphere: Observations from the dual Van Allen Probes
Authors: Blum L. W. , Bonnell J. W. , Agapitov O. , Paulson K. , Kletzing C. 
Published: January 2017

AbstractEstimating the spatial scales of electromagnetic ion cyclotron (EMIC) waves is critical for quantifying their overall scattering efficiency and effects on thermal plasma, ring current, and radiation belt particles. Using measurements from the dual Van Allen Probes in 2013–2014, we characterize the spatial and temporal extents of regions of EMIC wave activity and how these depend on local time and radial distance within the inner magnetosphere. Observations are categorized into three types—waves observed by only one spacecraft, waves measured by both spacecraft simultaneously, and waves observed by both spacecraft with some time lag. Analysis reveals that dayside (and H+ band) EMIC waves more frequently span larger spatial areas, while nightside (and He+ band) waves are more often localized but can persist many hours. These investigations give insight into the nature of EMIC wave generation and support more accurate quantification of their effects on the ring current and outer radiation belt.
The vanishing cryovolcanoes of Ceres
Authors: Sori Michael M. , Byrne Shane , Bland Michael T. , Bramson Ali M. , Ermakov Anton I. , Hamilton Christopher W. , Otto Katharina A. , Ruesch Ottaviano , Russell Christopher T. 
Published: January 2017

AbstractAhuna Mons is a 4 km tall mountain on Ceres interpreted as a geologically young cryovolcanic dome. Other possible cryovolcanic features are more ambiguous, implying that cryovolcanism is only a recent phenomenon or that other cryovolcanic structures have been modified beyond easy identification. We test the hypothesis that Cerean cryovolcanic domes viscously relax, precluding ancient domes from recognition. We use numerical models to predict flow velocities of Ahuna Mons to be 10–500 m/Myr, depending upon assumptions about ice content, rheology, grain size, and thermal parameters. Slower flow rates in this range are sufficiently fast to induce extensive relaxation of cryovolcanic structures over 108–109 years, but gradual enough for Ahuna Mons to remain identifiable today. Positive topographic features, including a tholus underlying Ahuna Mons, may represent relaxed cryovolcanic structures. A composition for Ahuna Mons of >40% ice explains the observed distribution of cryovolcanic structures because viscous relaxation renders old cryovolcanoes unrecognizable.
Study of the effect of 17–18 March 2015 geomagnetic storm on the Indian longitudes using GPS and C/NOFS
Authors: Ray Sarbani , Roy Bidyut , Paul Krishnendu Sekhar , Goswami Samiddha , Oikonomou Christina , Haralambous Haris , Chandel Babita , Paul Ashik 
Published: January 2017

AbstractThe largest geomagnetic storm in solar cycle 24 occurred during 17–18 March 2015 where the main phase of the storm commenced from 07:00 UT of 17 March 2015 and reached the Dst negative minimum at 22:00 UT. The present paper reports observations of total electron content (TEC), amplitude, and phase scintillations from different GPS stations of India during the storm of 17 March and highlights its effects on GPS. It also presents the global equatorial spread F (ESF) occurrence during the storm using total ion density drift measurements from Communication and Navigation Outage Forecast System (C/NOFS) satellite. TEC enhancements were noted from stations along 77°E meridian around 10:00 UT on 17 March compared to 16 and 18 March indicating positive storm effects arising out of equatorward neutral wind in the local morning to noon sector of the main phase. Intense scintillation observations from Calcutta were most extensive during 15:00–16:00 UT, 17 March, and the receiver recorded a longitude deviation of 5.2 m during this time. Cycle slips of the order of 8 s could be observed during periods of intense phase scintillations on the same night. Intense scintillation observation from Palampur is an exceptional phenomenon attributed to the dramatic enhancement of the electric field due to prompt penetrating (undershielded) electric leading to a very high upward ion velocity over the magnetic equator as recorded by C/NOFS. The total ion density measured globally by C/NOFS reveals two distinct longitude regions of ESF occurrence during the storm: (i) East Pacific sector and (ii) Indian longitude during the storm. The time and longitude of ESF occurrence could be predicted using the time of southward turning of interplanetary magnetic field Bz.
Correlations between substrate availability, dissolved CH4, and CH4 emissions in an arctic wetland subject to warming and plant removal
Authors: Nielsen Cecilie Skov , Michelsen Anders , Strobel Bjarne W. , Wulff Katrine , Banyasz Imre , Elberling Bo 
Published: January 2017

AbstractThe Arctic is warming which may potentially affect substrate availability, organic matter decomposition, plant growth, and plant species composition. This may lead to changes in the exchange of methane (CH4) and carbon dioxide (CO2) between the soil system and the atmosphere. Yet the correlations among substrate availability, CH4 production, and net emissions of CH4 have been scarcely studied in arctic wetlands. Presently, the impact of increasing temperatures on CH4 exchange is uncertain as the two existing reports on field warming in arctic wetlands present opposite results. We here report results on how summer warming and shrub removal affect soil water substrate (acetate, formate, oxalate, and dissolved organic carbon) concentrations as well as dissolved CH4 and CH4 emissions in a fen at Disko Island (West Greenland). The peak in dissolved CH4 followed the peak in acetate concentration, and appeared after the peak in CH4 emissions, which indicates a lack of correlation between CH4 production and emissions. The peak in CH4 emissions coincided with maximum gross ecosystem production suggesting that CH4 emissions are closely linked to photosynthesis. This was supported by an experiment with removal of the sedge Carex aquatilis ssp. stans which contributed with up to 77% of the CH4 emitted from the ecosystem. By contrast, shrub removal and summer warming did not significantly affect CH4 emissions, possibly due to the treatments impacting CH4 production more than emissions. This implies that such wetlands may be less sensitive to moderate warming and changes in shrub cover than previously assumed.
Fluxes all of the time? A primer on the temporal representativeness of FLUXNET
Authors: Chu Housen , Baldocchi Dennis D. , John Ranjeet , Wolf Sebastian , Reichstein Markus 
Published: January 2017

AbstractFLUXNET, the global network of eddy covariance flux towers, provides the largest synthesized data set of CO2, H2O, and energy fluxes. To achieve the ultimate goal of providing flux information “everywhere and all of the time,” studies have attempted to address the representativeness issue, i.e., whether measurements taken in a set of given locations and measurement periods can be extrapolated to a space‐ and time‐explicit extent (e.g., terrestrial globe, 1982–2013 climatological baseline). This study focuses on the temporal representativeness of FLUXNET and tests whether site‐specific measurement periods are sufficient to capture the natural variability of climatological and biological conditions. FLUXNET is unevenly representative across sites in terms of the measurement lengths and potentials of extrapolation in time. Similarity of driver conditions among years generally enables the extrapolation of flux information beyond measurement periods. Yet such extrapolation potentials are further constrained by site‐specific variability of driver conditions. Several driver variables such as air temperature, diurnal temperature range, potential evapotranspiration, and normalized difference vegetation index had detectable trends and/or breakpoints within the baseline period, and flux measurements generally covered similar and biased conditions in those drivers. About 38% and 60% of FLUXNET sites adequately sampled the mean conditions and interannual variability of all driver conditions, respectively. For long‐record sites (≥15 years) the percentages increased to 59% and 69%, respectively. However, the justification of temporal representativeness should not rely solely on the lengths of measurements. Whenever possible, site‐specific consideration (e.g., trend, breakpoint, and interannual variability in drivers) should be taken into account.
Increased C3 productivity in Midwestern lawns since 1982 revealed by carbon isotopes in Amanita thiersii
Authors: Hobbie Erik A. , Schubert Brian A. , Craine Joseph M. , Linder Ernst , Pringle Anne 
Published: January 2017

AbstractHow climate and rising carbon dioxide concentrations (pCO2) have influenced competition between C3 and C4 plants over the last 50 years is a critical uncertainty in climate change research. Here we used carbon isotope (δ13C) values of the saprotrophic lawn fungus Amanita thiersii to integrate the signal of C3 and C4 carbon in samples collected between 1982 and 2009 from the Midwestern USA. We then calculated 13C fractionation (Δ) to assess the balance between C3 and C4 photosynthesis as influenced by mean annual temperature (MAT), mean annual precipitation over a 30 year period (MAP‐30), and pCO2. Sporocarp Δ correlated negatively with MAT (−1.74‰ °C−1, 79% of variance) and positively with MAP (9.52‰ m−1, 15% of variance), reflecting the relative productivity of C3 and C4 grasses in lawns. In addition, Δ values correlated positively with pCO2 (0.072‰ ppm−1, 5% of variance). Reduced photorespiration with rising pCO2 accounted for 20% of this increased Δ, but the remaining 80% is consistent with increased assimilation of C3‐derived carbon by Amanita thiersii resulting from increased productivity of C3 grasses with rising pCO2. Between 1982 and 2009, pCO2 rose by 46 ppm and the relative contribution of C3 photosynthesis to Amanita thiersii carbon increased 18.5%. The δ13C value of Amanita thiersii may integrate both lawn maintenance practices and the physiological responses of turf grasses to rising CO2 concentrations.
Erosion of organic carbon from the Andes and its effects on ecosystem carbon dioxide balance
Authors: Clark K. E. , Hilton R. G. , West A. J. , Robles Caceres A. , Gröcke D. R. , Marthews T. R. , Ferguson R. I. , Asner G. P. , New M. , Malhi Y. 
Published: January 2017

AbstractProductive forests of the Andes are subject to high erosion rates that supply to the Amazon River sediment and carbon from both recently photosynthesized biomass and geological sources. Despite this recognition, the source and discharge of particulate organic carbon (POC) in Andean Rivers remain poorly constrained. We collected suspended sediments from the Kosñipata River, Peru, over 1 year at two river gauging stations. Carbon isotopes (14C, 13C, and 12C) and nitrogen to organic carbon ratios of the suspended sediments suggest a mixture of POC from sedimentary rocks (POCpetro) and from the terrestrial biosphere (POCbiosphere). The majority of the POCbiosphere has a composition similar to surface soil horizons, and we estimate that it is mostly younger than 850 14C years. The suspended sediment yield in 2010 was 3500 ± 210 t km−2 yr−1, >10 times the yield from the Amazon Basin. The POCbiosphere yield was 12.6 ± 0.4 t C km−2 yr−1 and the POCpetro yield was 16.1 ± 1.4 t C km−2 yr−1, mostly discharged in the wet season (December to March) during flood events. The river POCbiosphere discharge is large enough to play a role in determining whether Andean forests are a source or sink of carbon dioxide. The estimated erosional discharge of POCpetro from the Andes is much larger (~1 Mt C yr−1) than the POCpetro discharge by the Madeira River downstream in the Amazon Basin, suggesting that oxidation of POCpetro counters CO2 drawdown by silicate weathering. The flux and fate of Andean POCbiosphere and POCpetro need to be better constrained to fully understand the carbon budget of the Amazon River basin.
Nonmonotonic and spatial‐temporal dynamic slope effects on soil erosion during rainfall‐runoff processes
Authors: Wu Songbai , Yu Minghui , Chen Li 
Published: January 2017

AbstractThe slope effect on flow erosivity and soil erosion still remains a controversial issue. This theoretical framework explained and quantified the direct slope effect by coupling the modified Green‐Ampt equation accounting for slope effect on infiltration, 1‐D kinematic wave overland flow routing model, and WEPP soil erosion model. The flow velocity, runoff rate, shear stress, interrill, and rill erosion were calculated on 0°–60° isotropic slopes with equal horizontal projective length. The results show that, for short‐duration rainfall events, the flow erosivity and erosion amounts exhibit a bell‐shaped trend which first increase with slope gradient, and then decrease after a critical slope angle. The critical slope angles increase significantly or even vanish with increasing rainfall duration but are nearly independent of the slope projective length. The soil critical shear stress, rainfall intensity, and temporal patterns have great influences on the slope effect trend, while the other soil erosion parameters, soil type, hydraulic conductivity, and antecedent soil moisture have minor impacts. Neglecting the slope effect on infiltration would generate smaller erosion and reduce critical slope angles. The relative slope effect on soil erosion in physically based model WEPP was compared to those in the empirical models USLE and RUSLE. The trends of relative slope effect were found quite different, but the difference may diminish with increasing rainfall duration. Finally, relatively smaller critical slope angles could be obtained with the equal slope length and the range of variation provides a possible explanation for the different critical slope angles reported in previous studies.
The future role of dams in the United States of America
Authors: Ho Michelle , Lall Upmanu , Allaire Maura , Devineni Naresh , Kwon Hyun Han , Pal Indrani , Raff David , Wegner David 
Published: January 2017

AbstractStorage and controlled distribution of water have been key elements of a human strategy to overcome the space and time variability of water, which have been marked by catastrophic droughts and floods throughout the course of civilization. In the United States, the peak of dam building occurred in the mid‐20th century with knowledge limited to the scientific understanding and hydrologic records of the time. Ecological impacts were considered differently than current legislative and regulatory controls would potentially dictate. Additionally, future costs such as maintenance or removal beyond the economic design life were not fully considered. The converging risks associated with aging water storage infrastructure and uncertainty in climate in addition to the continuing need for water storage, flood protection, and hydropower result in a pressing need to address the state of dam infrastructure across the nation. Decisions regarding the future of dams in the United States may, in turn, influence regional water futures through groundwater outcomes, economic productivity, migration, and urban growth. We advocate for a comprehensive national water assessment and a formal analysis of the role dams play in our water future. We emphasize the urgent need for environmentally and economically sound strategies to integrate surface and groundwater storage infrastructure in local, regional, and national water planning considerations. A research agenda is proposed to assess dam failure impacts and the design, operation, and need for dams considering both paleo and future climate, utilization of groundwater resources, and the changing societal values toward the environment.
Predictors of Reduced Health‐Related Quality of Life in Adult Patients With Idiopathic Inflammatory Myopathies
Authors: Feldon Michal , Farhadi Payam Noroozi , Brunner Hermine I. , Itert Lukasz , Goldberg Bob , Faiq Abdullah , Wilkerson Jesse , Rose Kathryn M. , Rider Lisa G. , Miller Frederick W. , Giannini Edward H. 
Published: January 2017

ObjectiveExtensive studies on health‐related quality of life (HRQoL) in idiopathic inflammatory myopathies (IIMs) are lacking. Our objective was to document HRQoL and to identify factors associated with a reduced HRQoL in patients with IIM.MethodsA total of 1,715 patients (median age 49.9 years, 70% female, 87% white) who met probable or definite Bohan and Peter criteria or Griggs criteria for myositis were included from the Myovision registry. HRQoL was ascertained using the Short Form 12 (SF‐12) health survey questionnaire. HRQoL physical component summary (PCS) and mental component summary (MCS) scores in relation to different patient and disease characteristics were compared to scores from matched normative data from the US general population and rheumatoid arthritis (RA) patients. Bivariate and multiple linear regression analyses were performed to assess the association between HRQoL and patient and disease parameters.ResultsThe mean SF‐12 summary scores were significantly lower in IIM patients than in the normative and RA populations. A diagnosis of inclusion body myositis, older age, patient‐reported negative effect of disease on work, presence of another co‐occurring autoimmune disease, polypharmacy, and IIM‐associated lung disease and joint involvement were significantly associated with lower PCS scores. Lower MCS scores were associated with joint involvement and a negative effect of disease on work.ConclusionIn this large study of patient‐reported outcomes in IIM, an association was found between multiple disease characteristics and reduced HRQoL, mostly in the physical domain. In the US, the HRQoL of IIM patients was found to be lower than that of the general population and RA patients.
From Childhood to Adulthood: The Trajectory of Damage in Patients With Juvenile‐Onset Systemic Lupus Erythematosus
Authors: Lim Lily S. H. , Pullenayegum Eleanor , Lim Lillian , Gladman Dafna , Feldman Brian , Silverman Earl 
Published: January 2017

ObjectiveTo determine the longitudinal damage trajectory of patients with juvenile‐onset systemic lupus erythematosus (SLE), and to identify baseline and disease course predictors of damage trajectory.MethodsThis is a retrospective inception cohort. Longitudinal pediatric‐age data were obtained from a juvenile‐onset SLE research database, while adult‐age data were obtained from either a research database or patients' charts. Baseline factors were tested as predictors. Time‐varying factors were lagged 6–24 months before a visit for testing their predictive effects. The longitudinal damage trajectory was modeled using a weighted generalized estimating equation.ResultsThis study cohort consisted of 473 subjects, with followup to 26 years. A total of 65% of patients were ages >18 years at last followup. Cataracts (14%), avascular necrosis (10%), and osteoporosis (5%) were the most common items of damage. Two patients had myocardial infarctions. Baseline features, self‐reported ethnicity (Afro‐Caribbean), earlier time periods of diagnosis, and the presence of a life‐threatening major organ manifestation (lupus nephritis class III–V, cerebrovascular accidents, major organ vasculitis, pulmonary hemorrhage, or myocarditis), were associated with greater damage. Throughout the disease course, an acute confusional state, lupus headache, and fever predicted subsequent increases in the damage trajectory. A higher prednisone dose and exposure to cyclophosphamide also predicted subsequent increases in the damage trajectory. Antimalarial exposure was protective against an increase in damage trajectory.ConclusionPatients with juvenile‐onset SLE accrue damage steadily into adulthood. Baseline factors predict greater damage and/or influence the evolution of the damage trajectory. Additionally, SLE clinical features and therapies during the course of disease predict additional changes in the damage trajectory.