bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mesoscale variability and its seasonality in the Solomon and Coral Seas
Authors: Hristova Hristina G. , Kessler William S. , McWilliams James C. , Molemaker M. Jeroen 
Published: July 2014

AbstractHigh‐resolution (4 km) climatologically forced ocean model, validated by altimetry and glider data, is used to characterize the vertical and seasonal variations of mesoscale variability in the Solomon and Coral Seas. The highest eddy kinetic energy (EKE) in the southwest Pacific is found subsurface in the Gulf of Papua, at the depth of the low‐latitude western boundary current velocity core. Variability associated with the western boundary current, especially downstream of topographic obstacles, dominates the thermocline and intermediate level EKE. By contrast, surface EKE is generally enhanced in the southwest Pacific with a pronounced annual cycle that has a phase difference between small‐scale and large‐scale variability. Large mesoscale eddies account for most of the surface EKE and its annual modulation. The June maximum of surface EKE in the Solomon Sea and the December maximum in the Coral Sea can be accounted for by local instabilities of large‐scale currents. Small mesoscale eddies, predominantly cyclonic, are abundant in late winter (August to September), coinciding with the timing of deepest mixed layer and strongest vertical velocity. They contribute to the spatially uniform surface‐enhanced EKE over the top 100 m, not associated with the western boundary current. In the Coral Sea, small mesoscale eddies are generated mostly by open‐ocean surface baroclinic instabilities, while in the land‐bounded Solomon Sea near‐boundary instabilities and topographic generation are also important.
Topographic controls on shallow groundwater levels in a steep, prealpine catchment: When are the TWI assumptions valid?
Authors: Rinderer M. , van Meerveld H. J. , Seibert J. 
Published: July 2014

AbstractTopographic indices like the Topographic Wetness Index (TWI) have been used to predict spatial patterns of average groundwater levels and to model the dynamics of the saturated zone during events (e.g., TOPMODEL). However, the assumptions underlying the use of the TWI in hydrological models, of which the most important is that groundwater level variation can be approximated by a series of steady state situations, are rarely tested. It is also not clear how well findings from existing hillslope studies on sites with transmissive soil can be transferred to entire catchments with less permeable soils. This study, therefore, evaluated the suitability of selected topographic indices to describe spatial groundwater level variations based on time series from 51 groundwater wells in a 20 ha catchment with low‐permeability soils in Switzerland. Results showed that median groundwater levels were correlated to slope, curvature, and TWI, but the strength of correlation depended on whether the indices characterized the local topography or the topography of the upslope contributing area. The correlation between TWI and groundwater levels was not constant over time but decreased at the beginning of rainfall events, indicating large spatial differences in groundwater responses, and increased after peak flow, when groundwater levels could be considered to be spatially in a steady state. Our findings indicate that topographic indices are useful to predict median groundwater levels in catchments with low‐permeability soils and that the TWI assumptions are best met when groundwater levels change slowly.
Continuous uplift near the seaward edge of the Prince William Sound megathrust: Middleton Island, Alaska
Authors: Savage J. C. , Plafker G. , Svarc J. L. , Lisowski M. 
Published: July 2014

AbstractMiddleton Island, located at the seaward edge of the continental shelf 50 km from the base of the inner wall of the Aleutian Trench, affords an opportunity to make land‐based measurements of uplift near the toe of the Prince William Sound megathrust, site of the 1964, M = 9.2, Alaska earthquake. Leveling surveys (1973–1993) on Middleton Island indicate roughly uniform tilting (~1 µrad/a down to the northwest) of the island, and GPS surveys (1993–2012) show an uplift rate of 14 mm/a of the island relative to fixed North America. The data are consistent with a combined (coseismic and postseismic) uplift (in meters) due to the 1964 earthquake as a function of time τ (years after the earthquake) u(τ) = (3.5 + 1.21 log10 [1 + 1.67 τ]) H(τ) where 3.5 is the coseismic uplift and H(τ) is 0 for τ < 0 and 1 otherwise. The current uplift on Middleton Island is attributed to continuous slip on a fault splaying off from the megathrust, and the long‐term uplift is the superposition of the effects of past earthquakes, each earthquake being similar to the 1964 event. Then, the predicted uplift at time t due to a sequence of earthquakes at times ti would be . From studies of strandlines associated with the uplifted terraces on Middleton Island, Plafker et al. (1992) estimated the occurrence times of the last six earthquakes and measured the present‐day elevations of those strandlines. The predicted uplift is in rough agreement with those measurements. About half of the predicted uplift is due to postseismic relaxation from previous earthquakes.
Seasonal migration of the Yellow Sea Bottom Cold Water
Authors: Wang Bin , Hirose Naoki , Kang Boonsoon , Takayama Katsumi 
Published: July 2014

AbstractThe three‐dimensional motion of the Yellow Sea Bottom Cold Water (YSBCW) and the relevant dynamical factors are studied using a regional circulation model and the two‐way Lagrangian particle tracking method (PTM). The simulated results are in good agreement with hydrographic observations. The trajectories of the modeled particles show that the subsurface cold heavy water mass from the northern part of the Yellow Sea gradually sinks into deeper layers along the western slope of the Yellow Sea trough with a southward movement from spring to summer. The cold water mass gradually gathers speed from early March to July or August, and eventually reaches its southernmost location in late September or early October. Furthermore, sensitivity experiments demonstrate that tide‐induced residual currents under baroclinic conditions are the dominant factor driving deep circulation during summertime in the Yellow Sea. The summer southerly wind and strong surface solar radiation are the secondary factors influencing the southward migration. This study also proposes an improved delimitation for the YSBCW based on temperature statistics in the central basin (deeper than 40 m) between 35°N and 39°N in March with an increase in rate of approximately 0.7°C/month, which is more appropriate than the constants of the 8°C or 10°C isotherms frequently used.
Extensive hydrogen supersaturations in the western South Atlantic Ocean suggest substantial underestimation of nitrogen fixation
Authors: Moore Robert M. , Kienast Markus , Fraser Michael , Cullen John J. , Deutsch Curtis , Dutkiewicz Stephanie , Follows Michael J. , Somes Christopher J. 
Published: July 2014

AbstractThe nitrogen cycle is fundamental to Earth's biogeochemistry. Yet major uncertainties of quantification remain, particularly regarding the global oceanic nitrogen fixation rate. Hydrogen is produced during nitrogen fixation and will become supersaturated in surface waters if there is net release from diazotrophs. Ocean surveys of hydrogen supersaturation thus have the potential to illustrate the spatial and temporal distribution of nitrogen fixation and to guide the far more onerous but quantitative methods for measuring it. Here we present the first transect of high resolution measurements of hydrogen supersaturations in surface waters along a meridional 10,000 km cruise track through the Atlantic. We compare measured saturations with published measurements of nitrogen fixation rates and also with model‐derived values. If the primary source of excess hydrogen is nitrogen fixation and has a hydrogen release ratio similar to Trichodesmium, our hydrogen measurements would point to similar rates of fixation in the North and South Atlantic, roughly consistent with modeled fixation rates but not with measured rates, which are lower in the south. Possible explanations would include any substantial nitrogen fixation by newly discovered diazotrophs, particularly any having a hydrogen release ratio similar to or exceeding that of Trichodesmium; undersampling of nitrogen fixation south of the equator related to excessive focus on Trichodesmium; and methodological shortcomings of nitrogen fixation techniques that cause a bias toward colonial diazotrophs relative to unicellular forms. Alternatively, our data are affected by an unknown hydrogen source that is greater in the southern half of the cruise track than the northern.
Spatial characterization of roughness elements in high‐gradient channels of the Fraser Experimental Forest, Colorado, USA
Authors: Yochum Steven E. , Bledsoe Brian P. , Wohl Ellen , David Gabrielle C. L. 
Published: July 2014

AbstractWe collected high‐resolution LiDAR‐based spatial and reach‐average flow resistance data at a range of flows in headwater stream channels of the Fraser Experimental Forest, Colorado, USA. Using these data, we implemented a random field approach for assessing the variability of detrended bed elevations and flow depths for both the entire channel width and the thalweg‐centered 50% of the channel width (to exclude bank effects). The spatial characteristics of these channels, due to bedforms, large clasts and instream wood, were compared with Darcy‐Weisbach f and stream type through the use of the first four probability density function moments (mean, variance, skewness, kurtosis). The standard deviation of the bed elevations (σz) combined with depth (h), as relative bedform submergence (h/σz), was well correlated with f (R2 = 0.81) for the 50% of channel width. The explained variance decreased substantially (R2 = 0.69) when accounting for the entire width, indicating lesser contribution of channel edges to flow resistance. The flow depth skew also explained a substantial amount of the variance in f (R2 = 0.78). A spectrum of channel types is evident in depth plots of skew versus kurtosis, with channel types ranging from plane bed, transitional, step pool/cascade, to cascade. These results varied when bank effects were included or excluded, although definitive patterns were observed for both analyses. Random field analyses may be valuable for developing tools for predicting flow resistance, as well as for quantifying the spectrum of morphologic change in high‐gradient channel types, from plane bed through cascade.
Derivation of lowland riparian wetland deposit architecture using geophysical image analysis and interface detection
Authors: Chambers J. E. , Wilkinson P. B. , Uhlemann S. , Sorensen J. P. R. , Roberts C. , Newell A. J. , Ward W. O. C. , Binley A. , Williams P. J. , Gooddy D. C. , Old G. , Bai L. 
Published: July 2014

AbstractFor groundwater‐surface water interactions to be understood in complex wetland settings, the architecture of the underlying deposits requires investigation at a spatial resolution sufficient to characterize significant hydraulic pathways. Discrete intrusive sampling using conventional approaches provides insufficient sample density and can be difficult to deploy on soft ground. Here a noninvasive geophysical imaging approach combining three‐dimensional electrical resistivity tomography (ERT) and the novel application of gradient and isosurface‐based edge detectors is considered as a means of illuminating wetland deposit architecture. The performance of three edge detectors were compared and evaluated against ground truth data, using a lowland riparian wetland demonstration site. Isosurface‐based methods correlated well with intrusive data and were useful for defining the geometries of key geological interfaces (i.e., peat/gravels and gravels/Chalk). The use of gradient detectors approach was unsuccessful, indicating that the assumption that the steepest resistivity gradient coincides with the associated geological interface can be incorrect. These findings are relevant to the application of this approach in settings with a broadly layered geology with strata of contrasting resistivities. In addition, ERT revealed substantial structures in the gravels related to the depositional environment (i.e., braided fluvial system) and a complex distribution of low‐permeability putty Chalk at the bedrock surface—with implications for preferential flow and variable exchange between river and groundwater systems. These results demonstrate that a combined approach using ERT and edge detectors can provide valuable information to support targeted monitoring and inform hydrological modeling of wetlands.
Defining Criteria for Disease Activity States in Nonsystemic Juvenile Idiopathic Arthritis Based on a Three‐Variable Juvenile Arthritis Disease Activity Score
Authors: Consolaro Alessandro , Negro Giorgia , Chiara Gallo Maria , Bracciolini Giulia , Ferrari Cristina , Schiappapietra Benedetta , Pistorio Angela , Bovis Francesca , Ruperto Nicolino , Martini Alberto , Ravelli Angelo 
Published: July 2014

ObjectiveTo determine cutoff values for defining the states of inactive disease (ID), low disease activity (LDA; or minimal disease activity), moderate disease activity (MDA), and high disease activity (HDA) using the clinical (3‐variable) Juvenile Arthritis Disease Activity Score (cJADAS).MethodsFor selection of cutoffs, data from a clinical database including 609 children with juvenile idiopathic arthritis (JIA) were used. Optimal cutoffs were determined against external criteria by calculating the 75th and 90th percentile (for ID and LDA) and 10th and 25th percentile (for HDA) of cumulative score distribution and through receiver operating characteristic curve analysis. External criteria included definitions for ID and LDA cutoffs and therapeutic decisions for HDA cutoffs. MDA cutoffs were set at the score interval in‐between LDA and HDA cutoffs. Crossvalidation was performed using 2 JIA patient samples (n = 485) and was based on assessment of construct and discriminant validity.ResultsThe selected cutoffs were as follows: ≤1 for ID in both oligoarthritis and polyarthritis; ≤1.5 and ≤2.5 for LDA in oligoarthritis and polyarthritis, respectively; 1.51–4 and 2.51–8.5 for MDA in oligoarthritis and polyarthritis, respectively; and >4 and >8.5 for HDA in oligoarthritis and polyarthritis, respectively. In crossvalidation analyses, the cutoffs showed a strong ability to discriminate between disease activity states defined subjectively by physicians and parents, levels of pain, and presence/absence of functional impairment and disease damage.ConclusionCutoff values for classifying various disease states in nonsystemic JIA using the cJADAS were developed. The cutoffs revealed good measurement characteristics in crossvalidation analyses and are suited for application in clinical practice and research.
Screening individuals with intellectual disability, autism and Tourette's syndrome for KCNK9 mutations and aberrant DNA methylation within the 8q24 imprinted cluster.
Authors: Delgado Marta Sánchez , Camprubí Cristina , Tümer Zeynep , Martínez Francisco , Milà Montserrat , Monk David 
Published: July 2014

AbstractThe phenotype overlap between autism spectrum disorders (ASD) & intellectual disabilities (ID) is mirrored at the genetic level, with common genes being reported mutated in variety of developmental disabilities. However despite widespread genetic screening for mutations, in approximately 40–60% of childhood developmental disorders the genetic cause remains unknown. Several genome‐wide linkage screens in ASD have identified a locus mapping to distal 8q. We have recently identified a novel brain‐specific imprinted cluster at this location, which contains the reciprocally expressed maternal KCNK9 and paternally expressed non‐coding PEG13 transcripts, the latter located within an intron of TRAPPC9. Interestingly, mutations of KCNK9 and TRAPPC9 have been reported in Birk‐Barel mental retardation and non‐syndromic familial forms of ID, respectively.Here, we report a genetic screen for KCNK9 coding mutations and potential epigenetic aberrations that could result in deregulated imprinting in a cohort of 120 ID, 86 ASD and 86 Tourette syndrome patients. Fifteen of the ID patients had clinical characteristics overlapping with Birk‐Barel syndrome. Sequencing of the two coding exons of KCNK9 failed to identify pathologic mutations, with only one variant, rs2615374, being present with allele frequencies similar to those described in dbSNP database. DNA methylation profiling of the KCNK9 and TRAPPC9 promoters, the maternally methylated PEG13 DMR and a long‐range enhancer region were normal in all patients. Our findings suggest that mutations of KCNK9 or epigenetic disturbances within the PEG13 imprinted cluster do not significantly contribute to the cause of the developmental disabilities tested in this study. © 2014 Wiley Periodicals, Inc.
Direct Observation of Atomic Dynamics and Silicon Doping at a Topological Defect in Graphene
Authors: Yang Zhiqing , Yin Lichang , Lee Jaekwang , Ren Wencai , Cheng Hui‐Ming , Ye Hengqiang , Pantelides Sokrates T. , Pennycook Stephen J. , Chisholm Matthew F. 
Published: July 2014

AbstractChemical decoration of defects is an effective way to functionalize graphene and to study mechanisms of their interaction with environment. We monitored dynamic atomic processes during the formation of a rotary Si trimer in monolayer graphene using an aberration‐corrected scanning‐transmission electron microscope. An incoming Si atom competed with and replaced a metastable C dimer next to a pair of Si substitutional atoms at a topological defect in graphene, producing a Si trimer. Other atomic events including removal of single C atoms, incorporation and relocation of a C dimer, reversible CC bond rotation, and vibration of Si atoms occurred before the final formation of the Si trimer. Theoretical calculations indicate that it requires 2.0 eV to rotate the Si trimer. Our real‐time results provide insight with atomic precision for reaction dynamics during chemical doping at defects in graphene, which have implications for defect nanoengineering of graphene.
Palladium‐Catalyzed Oxidative Arylating Carbocyclization of Allenynes: Control of Selectivity and Role of H2O
Authors: Bartholomeyzik Teresa , Mazuela Javier , Pendrill Robert , Deng Youqian , Bäckvall Jan‐E. 
Published: July 2014

AbstractHighly selective protocols for the carbocyclization/arylation of allenynes using arylboronic acids are reported. Arylated vinylallenes are obtained with the use of BF3⋅Et2O as an additive, whereas addition of water leads to arylated trienes. These conditions provide the respective products with excellent selectivities (generally >97:3) for a range of boronic acids and different allenynes. It has been revealed that water plays a crucial role for the product distribution.
Chemical Synthesis of Syndecan‐3 Glycopeptides Bearing Two Heparan Sulfate Glycan Chains
Authors: Yoshida Keisuke , Yang Bo , Yang Weizhun , Zhang Zeren , Zhang Jicheng , Huang Xuefei 
Published: July 2014

AbstractDespite the ubiquitous presence of proteoglycans in mammalian systems, methodologies to synthesize this class of glycopeptides with homogeneous glycans are not well developed. Herein, we report the first synthesis of a glycosaminoglycan family glycopeptide containing two different heparan sulfate chains, namely the extracellular domain of syndecan‐3. With the large size and tremendous structural complexity of these molecules, multiple unexpected obstacles were encountered during the synthesis, including high sensitivity to base treatment and the instability of glycopeptides with two glycan chains towards catalytic hydrogenation conditions. A successful strategy was established by constructing the partially deprotected single glycan chain containing glycopeptides first, followed by union of the glycan‐bearing fragments and cleavage of the ester‐type protecting groups. This work lays the foundation for preparing other members of this important class of molecules.
Nanomechanical properties of poly(trimethylene malonate) and poly(trimethylene itaconate) during hydrolytic degradation
Authors: Eyiler Ersan , Chu I.‐W. , Rowe Mathew D. , Walters Keisha B. 
Published: July 2014

AbstractThe aim of this work was to evaluate surface mechanical properties of two bioplastics, poly(trimethylene malonate) (PTM) and poly(trimethylene itaconate) (PTI), during hydrolytic degradation. Renewable resource‐based PTM and PTI were synthesized from 1,3‐propanediol (PDO), malonic acid (MA), and itaconic acid (IA) via melt polycondensation. The hydrolytic degradation was performed in deionized (DI) water (pH 5.4) at room temperature. Morphology and surface mechanical properties at the nanoscale were monitored by atomic force microscopy (AFM) using a quantitative nanomechanical property mapping mode as a function of degradation time. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to show shifted phase transitions depending on the degradation. DSC studies showed hydrolytic degradation induced crystallinity for PTI. After degradation for one week, the degree of crystallinity had significantly increased, and the elastic modulus of PTI had decreased by 58%. PTM was found to be hygroscopic. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41069.
Mechanical and thermal properties of novel rubber‐toughened epoxy blend prepared by in situ pre‐crosslinking
Authors: Zhou Heng‐Shi , Song Xiao‐Xue , Xu Shi‐Ai 
Published: July 2014

ABSTRACTA novel method is used for preparing liquid rubber‐toughened epoxy blend, in which an initiator was added to the liquid rubber–epoxy mixture to initiate crosslinking reaction of liquid rubber, and then curing agent was added to form the thermoset. Two epoxy blends with carboxyl‐terminated butadiene‐acrylonitrile copolymers were prepared using traditional and novel methods respectively. Results indicated that the novel rubber‐toughened epoxy blend exhibited much better mechanical properties than its traditional counterpart. The morphologies of the blends were explored by transmission electron microscopy (TEM), it was revealed that the use of the novel method formed a local interpenetrating network structure in the blend, which substantially improved the interfacial adhesion. The impact fracture surfaces of the two blends were observed by scanning electron microscopy (SEM) to explore the toughening mechanism, it was found that crack pinning was the major toughening mechanism for the novel rubber‐toughened epoxy blend. Dynamic mechanical analysis (DMA) was applied to determine the Tg values of the blends, which were found to be close. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41110.