bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mixing and remineralization in waters detrained from the surface into Subantarctic Mode Water and Antarctic Intermediate Water in the southeastern Pacific
Authors: Carter B. R. , Talley L. D. , Dickson A. G. 
Published: June 2014

AbstractA hydrographic data set collected in the region and season of Subantarctic Mode Water and Antarctic Intermediate Water (SAMW and AAIW) formation in the southeastern Pacific allows us to estimate the preformed properties of surface water detrained into these water masses from deep mixed layers north of the Subantarctic Front and Antarctic Surface Water south of the front. Using 10 measured seawater properties, we estimate: the fractions of SAMW/AAIW that originate as surface source waters, as well as fractions that mix into these water masses from subtropical thermocline water above and Upper Circumpolar Deep Water below the subducted SAMW/AAIW; ages associated with the detrained surface water; and remineralization and dissolution rates and ratios. The mixing patterns imply that cabbeling can account for ∼0.005–0.03 kg m−3 of additional density in AAIW, and ∼0–0.02 kg m−3 in SAMW. We estimate a shallow depth (∼300–700 m, above the aragonite saturation horizon) calcium carbonate dissolution rate of 0.4 ± 0.2 µmol CaCO3 kg−1 yr−1, a phosphate remineralization rate of 0.031 ± 0.009 µmol P kg−1 yr−1, and remineralization ratios of P:N:–O2:Corg of 1:(15.5 ± 0.6):(143 ± 10):(104 ± 22) for SAMW/AAIW. Our shallow depth calcium carbonate dissolution rate is comparable to previous estimates for our region. Our –O2:P ratio is smaller than many global averages. Our model suggests neglecting diapycnal mixing of preformed phosphate has likely biased previous estimates of –O2:P and Corg:P high, but that the Corg:P ratio bias may have been counteracted by a second bias in previous studies from neglecting anthropogenic carbon gradients.
Variations of Luzon Undercurrent from observations and numerical model simulations
Authors: Wang Qingye , Zhai Fangguo , Hu Dunxin 
Published: June 2014

AbstractSignificant intraseasonal variability (ISV) of about 45–80 days and seasonal variation of the Luzon Undercurrent (LUC) at 18°N are studied using direct current measurements and a high‐resolution global Hybrid Coordinate Ocean Model. The variations of the LUC are vertically coherent with those of Kuroshio Current both on intraseasonal and seasonal time scales. The ISV of the LUC is dominated by eddies with diameters of about 200–300 km and extending from sea surface to intermediate layer east of Luzon Island. The LUC becomes strong (weak) when cyclonic (anticyclonic) eddies occur. The eddies east of Luzon Island mainly originate from the bifurcation point (∼13°N) of the North Equatorial Current. These eddies propagate northwestward at a typical propagation speed of about 0.16 m s−1 along the east coast of Philippines, gradually strengthen and pass the Luzon coast, and continue northward to Luzon strait. On seasonal time scale, the LUC is strong (weak) in boreal winter (summer), and this variation is related to the seasonal evolution of large‐scale ocean circulation east of Philippines mainly controlled by local wind forcing.
Two millennia of tropical cyclone‐induced mud layers in a northern Yucatán stalagmite: Multiple overlapping climatic hazards during the Maya Terminal Classic “megadroughts”
Authors: Frappier Amy Benoit , Pyburn James , Pinkey‐Drobnis Aurora D. , Wang Xianfeng , Corbett D. Reide , Dahlin Bruce H. 
Published: June 2014

AbstractAn annually laminated stalagmite from the northern Yucatán Peninsula contains mud layers from 256 cave flooding events over 2240 years. This new conservative proxy for paleotempestology recorded cave flooding events with a recurrence interval of 8.3 years during the twentieth century, with the greatest frequency during the twentieth century and the least frequent during the seventeenth century. Tropical cyclone (TC) events are unlikely to flood the cave during drought when the water table is depressed. Applying TC masking to the Chaac paleorainfall reconstruction suggests that the severity of the Maya “megadroughts” was underestimated. Without a high‐resolution radiometric geochronology of individual local TC events, speleothem isotope records cannot resolve whether the Terminal Classic Period in the northern Maya Lowlands was punctuated by several brief drought breaks with normal TCs, or whether the region was very dry and peppered by unusually severe and frequent hurricane seasons.
A dynamo explanation for Mercury's anomalous magnetic field
Authors: Cao Hao , Aurnou Jonathan M. , Wicht Johannes , Dietrich Wieland , Soderlund Krista M. , Russell Christopher T. 
Published: June 2014

AbstractRecent MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) measurements have shown that Mercury's magnetic field is axial‐dominant, yet strongly asymmetric with respect to the equator: the field strength in the Northern Hemisphere is approximately 3 times stronger than that in the Southern Hemisphere. Here we show that convective dynamo models driven by volumetric buoyancy with north‐south symmetric thermal boundaries are capable of generating quasi‐steady north‐south asymmetric magnetic fields similar to Mercury's. This symmetry breaking is promoted and stabilized when the core‐mantle boundary heat flux is higher at the equator than at high latitudes. The equatorially asymmetric magnetic field generation in our dynamo models corresponds to equatorially asymmetric kinetic helicity, which results from mutual excitation of two different modes of columnar convection. Our dynamo model can be tested by future assessment of Mercury's magnetic field from MESSENGER and BepiColombo as well as through investigations on Mercury's lower mantle temperature heterogeneity and buoyancy forcing in Mercury's core.
Shelf water and chlorophyll export from the Hatteras slope and outer shelf
Authors: Churchill James H. , Gawarkiewicz Glen G. 
Published: June 2014

AbstractUsing high‐resolution data acquired from a shipboard ADCP and a towed Scanfish equipped with a CTD and fluorometer, we examine the properties and transport of Middle Atlantic Bight (MAB) shelf water over a region of the Hatteras outer shelf and slope where MAB shelf water is commonly deflected offshore and entrained into the Gulf Stream. The data are from a period in early August 2004 when the seasonal pycnocline of the MAB is well developed and situated over a weakly stratified, near‐bottom shelf water mass commonly referred to as the cold pool. Our data show chlorophyll‐rich cold pool water carried rapidly southward over the slope and outer shelf, at a rate of up to 60 cm s−1, as part of the shelf‐edge frontal jet. This southward transport of chlorophyll‐rich cold pool water is shunted eastward and entrained into the Gulf Stream. However, the latitude band over which this export occurs varies significantly over the 7 day course of our study, a variation which is linked to an order 50 km shift in the latitude at which the Gulf Stream separates from the continental margin. The coupled rapid translation of the Gulf Stream frontal separation and the cold pool export zone is likely to have a significant impact on the movement and accumulation of biogenic material over the Hatteras slope and rise.
Pinning synchronization of complex networks with delayed nodes
Authors: Guo Wanli , Chen Shihua , Francis Austin 
Published: June 2014

SummaryThis paper reveals the dynamical mechanism of synchronization in general complex networks with delayed nodes. It considers, in particular, the global synchronization of complex networks without assuming any symmetry in the coupling matrix by using pinning controllers. Sufficient conditions for global synchronization are obtained by suitably adding linear and adaptive feedback controllers to a certain sub‐collection of the nodes and numerical examples that are provided to demonstrate the effectiveness of the theory. Copyright © 2014 John Wiley & Sons, Ltd.
Robotics‐based telepresence using multi‐modal interaction for individuals with visual impairments
Authors: Park Chung Hyuk , Howard Ayanna M. 
Published: June 2014

SUMMARYAlthough many assistive devices have been developed and utilized to aid in daily living, the most general assistive means for individuals with visual impairments are the walking cane and guide dogs. These assistive means are effective in assisting the user in navigating within an environment; however, the navigation space is limited to the proximal environment of the user. Thus, in this paper, we discuss a method to increase the range of accessibility to a remote environment through robotic embodiment that enables teleoperation and teleperception through multi‐modal feedback. In order to transform remote spatial information into a non‐visual modality, we present a framework for utilizing an RGB‐D‐based depth camera, a mobile robot, and a haptic interface for 3D haptic rendering to accomplish the goal of haptic exploration of a remote environment. Experiments with three different control methods for robot interaction are designed for users with and without visual impairments. Several hypothesis are built to study the correlation between control/feedback modality and performance in telerobotic operations. Results show that users performed best when combining semi‐autonomous navigation with 3D haptic exploration and also rated their experience with our system as fairly good. Copyright © 2014 John Wiley & Sons, Ltd.
The Cost of Post‐Harvest Forward Contracting in Corn and Soybeans
Authors: Mallory Mindy L. , Zhao Wenjiao , Irwin Scott H. 
Published: June 2014

ABSTRACTThis study estimates the cost of forward contracting corn and soybeans for January and March delivery from 1980 through 2009. Both corn and soybeans exhibited a downward trend in the cost of forward contracting for January delivery, in contrast to previous pre‐harvest results, and the March delivery cost of forward contracting is slightly downward sloped. The cost of post‐harvest forward contracting corn and soybeans averaged 2 cents and 6 cents respectively; this was much less than the cost of pre‐harvest forward contracting in recent years. We did not find an increase in cost associated with income shifting associated with January delivery. We conclude that January forward contracts offer a relatively inexpensive means of smoothing income across years.
C4‐consumers in southern europe: The case of friuli V.G. (NE‐Italy) during early and central middle ages
Authors: Iacumin P. , Galli E. , Cavalli F. , Cecere L. 
Published: June 2014

ABSTRACTIsotope variations were studied in necropolises of the early (6th to 7th century CE) and central (10th to 11th century CE) medieval period located in Fruili‐Venezia Giulia (Northeastern Italy). The two periods each shortly followed two great barbarian invasions that changed the politics and economy of Italy: the arrivals of Langobards in 578 CE and the Hungarian incursions from the end of the 9th to the first half of the 10th century. These events had a tragic effect on the economy of Friuli‐Venezia Giulia: severe depopulation and the partial abandonment of the countryside with fall of agricultural production. Am J Phys Anthropol 154:561–574, 2014. © 2014 Wiley Periodicals, Inc.
Effects of land‐use change on a diverse pleurocerid snail assemblage
Authors: Tolley‐Jordan Lori , Huryn Alexander D. , Bogan Arthur E. 
Published: June 2014

AbstractThe highest worldwide diversity of snails in the family Pleuroceridae (Caenogastropoda) is found in the Mobile River Basin, Alabama, USA. Here 76 species of pleurocerids have been described and 31 species are now considered extinct due primarily to impoundments in the Alabama River Basin. Of the major basins, only the mainstem of the Cahaba River remains free‐flowing and so provides a refuge for pleurocerid diversity. Using collections, descriptions, and museum vouchers, the impact of changing land‐use on pleurocerid diversity was explored in the Cahaba River Basin.Decadal scale (10 to 20 years) and century scale (70 to100 years) changes in snail diversity within the Cahaba River were determined using information on species distributions based on historical (1880–1940) collections and from 1992, and 2005–2006 surveys.Before 1940, 20 species of pleurocerid snails were reported from the basin, but in 1992 and 2005–2006, only 15 species were recovered. Conversion of the lower portion of the Cahaba River Basin from forest to agriculture before 1940, followed by silviculture and severe downcutting of the channel from headcutting, may have caused the loss of these species. However, two species historically recorded in the basin are thought to be erroneous identifications and reflect the necessity of a complete taxonomic revision of this group.No basin‐wide changes in species richness and composition were detected between 1992 and 2005. Declines in richness among several reaches, however, resulted in the population fragmentation of five species which were reflected in differences in mean richness at the catchment scale. A significant, negative relationship between richness and urban cover between surveys best explained species losses.Despite taxonomic difficulties, these results indicate that land‐use conversion during the last century has had significant, adverse effects on pleurocerid diversity. Continued threats are expected given the projections of increasing human population density for the south‐eastern USA which may lead to further land‐use alterations and instream modifications.Copyright © 2014 John Wiley & Sons, Ltd.
Protein Secondary Structure Prediction from Circular Dichroism Spectra Using a Self‐Organizing Map with Concentration Correction
Authors: Hall Vincent , Sklepari Meropi , Rodger Alison 
Published: June 2014

ABSTRACTCollecting circular dichroism (CD) spectra for protein solutions is a simple experiment, yet reliable extraction of secondary structure content is dependent on knowledge of the concentration of the protein—which is not always available with accuracy. We previously developed a self‐organizing map (SOM), called Secondary Structure Neural Network (SSNN), to cluster a database of CD spectra and use that map to assign the secondary structure content of new proteins from CD spectra. The performance of SSNN is at least as good as other available protein CD structure‐fitting algorithms. In this work we apply SSNN to a collection of spectra of experimental samples where there was suspicion that the nominal protein concentration was incorrect. We show that by plotting the normalized root mean square deviation of the SSNN predicted spectrum from the experimental one versus a concentration scaling‐factor it is possible to improve the estimate of the protein concentration while providing an estimate of the secondary structure. For our implementation (51 data points 240–190 nm in nm increments) good fits and structure estimates were obtained if the NRMSD (normalized root mean square displacement, RMSE/data range) is <0.03; reasonable for NRMSD <0.05; and variable above this. We also augmented the reference database with 100% helical spectra and truly random coil spectra. Chirality 26:471–482, 2014. © 2014 Wiley Periodicals, Inc.
Iron‐Mediated Coupling of Two Ethyl Anions to Form a 2‐Butyne Ligand
Authors: Bauer Heiko , Weismann Daniel , Wolmershäuser Gotthelf , Sun Yu , Sitzmann Helmut 
Published: June 2014

AbstractThe σ‐aryliron complexes [5CpFe(C6H3iPr2‐2,6)] (2, 5Cp = η5‐C5iPr5) and [4CpFe(C6H3iPr2‐2,6)] (6, 4Cp = η5‐C5HiPr4) are available from the halides [5CpFe(μ‐Br)]2 (1) and [4CpFe(μ‐Br)]2 (4) and have been used for σ/π rearrangement reactions with trialkylaluminum compounds. Whereas trimethylaluminum can be added to 2 and 6 to form the aryltrimethylaluminate complexes [5CpFe(μ,η6:η1‐C6H3iPr2‐2,6)AlMe3] (3) and [4CpFe(μ,η6:η1‐C6H3iPr2‐2,6)AlMe3] (7) in clean σ/π rearrangement reactions, the addition of tripropylaluminum to 6 afforded a mixture containing the aryl(bromo)dipropylaluminate complex [4CpFe(μ,η6:η1‐C6H3iPr2‐2,6)AlBr(C3H7)2] (8). With triethylaluminum, a similar product mixture was obtained and could be separated to yield the aryl(bromo)diethylaluminate [4CpFe(μ,η6:η1‐C6H3iPr2‐2,6) AlBr(C2H5)2] (9), the aryltriethylaluminate [4CpFe(μ,η6:η1‐C6H3iPr2‐2,6)Al(C2H5)3] (10), the arene complex [4CpFe(η6‐C6H4iPr2‐1,3)]Br (11), and the 2‐butyne complex [(4CpFe)2(μ,η2:η2‐MeCCMe)] (12). The formation of 12 involves the coupling of two ethyl groups with the loss of four hydrogen atoms and could also be observed in reactions of the bromide dimer 4 or the σ aryl complex 6 with ethylmagnesium bromide. The aluminates 3, 7, 8, and 10, the arene sandwich 11, the 2‐butyne complex 12, as well as the alkylcyclopentadienyliron(II) halides [5CpFe(μ‐Br)]2 (1), [4CpFe(μ‐Br)]2 (4), and [4CpFe(μ‐I)]2 (5) have been crystallographically characterized.
Rare‐Earth Cadmium Tellurite Chlorides with a Structural Type Exhibiting [Ln12(TeO3)12] Slabs Alternating with CdCl6 Octahedral Layers
Authors: Kharitonov Ivan D. , Charkin Dmitri O. , Berdonosov Peter S. , Black Cameron , Downie Lewis J. , Lightfoot Philip , Dolgikh Valery A. 
Published: June 2014

AbstractA series of new rare‐earth cadmium metal tellurite chlorides were synthesized by the salt flux technique and characterized by single‐crystal X‐ray diffraction. The new compounds CdSm2(TeO3)2Cl4 (I), CdEu2(TeO3)2Cl4 (II), and CdGd2(TeO3)2Cl4 (III), adopt layered structures corresponding to sequences of metal oxide [LnTeO3] and metal halide [Cd1–xCl3] layers. They expand the known family of 2D rare‐earth selenium oxyhalides into the realm of tellurium(IV) compounds and add a new targeted structure type involving rock salt slabs formed by edge‐sharing CdCl6 octahedra. The major differences in the structures of Se and Te compounds lie in the composition of the cationic slabs {[Ln11(SeO3)12]9+ vs. [Ln12(TeO3)12]12+} and symmetry (orthorhombic for selenites vs. tetragonal for tellurites).
Double‐Cube‐Shaped Mixed Chalcogen/Pentele Clusters from GaCl3 Melts
Authors: Eich Andreas , Hoffbauer Wilfried , Schnakenburg Gregor , Bredow Thomas , Daniels Jörg , Beck Johannes 
Published: June 2014

AbstractThe reactions of elemental antimony, tellurium, selenium and sulfur as well as antimony telluride and antimony sulfide in melts composed of GaCl3/SbCl3/ACl (A = Cu+, Ag+, PPh4+) yielded Ag(Sb7Te8)[GaCl4]6 (1), (Sb7Se8)[GaCl4]2[Ga2Cl7]3 (2), (Sb7Se8Cl2)[GaCl4]3 (3) and (Sb7S8Cl2)[GaCl4]3 (4). SbCl3 plays the role of the oxidant, and GaCl3 plays the role of the Lewis acidic chloride ion acceptor. All of the compounds form orange, air‐sensitive crystals. The crystal structures consist of discrete, double‐cube‐shaped, mixed antimony–chalcogen cationic clusters (Sb7Te8)5+, (Sb7Se8)5+, (Sb7Se8Cl2)3+ and (Sb7S8Cl2)3+. The anions are discrete chloridogallate [GaCl4]– and [Ga2Cl7]– anions. All compounds were characterized by single‐crystal X‐ray diffraction, energy‐dispersive electron‐beam X‐ray fluorescence spectroscopy, Raman vibrational spectroscopy and solid‐state 77Se NMR spectroscopy. Supporting gas‐phase and periodic DFT calculations allowed the assignments of the spectra and provided insights into the bonding situation of the hypervalent Sb atoms.
Asymmetric Organocatalytic Quadruple Cascade Reaction of 2‐Hydroxychalcone with Cinnamaldehyde for the Construction of Tetrahydro‐6H‐benzo[c]chromene Containing Five Stereocenters
Authors: Liu Lingyan , Zhu Yunna , Huang Kaimeng , Wang Bing , Chang Weixing , Li Jing 
Published: June 2014

AbstractAn asymmetric organocatalytic quadruple cascade reaction was developed for the stable and sterically hindered 2‐hydroxychalcones and substituted cinnamaldehydes. This process proceeded through an oxa‐Michael–Michael–Michael–aldol condensation to afford highly functionalized tetrahydro‐6H‐benzo[c]chromene derivatives with high diastereoselectivity and enantioselectivity (>99 % ee). The structure of adduct 4g with five stereocenters was unambiguously confirmed by single‐crystal X‐ray diffraction, and valuable mass spectrometry data provided direct support for the proposed reaction mechanism.
Post‐processing of medium‐range probabilistic hydrological forecasting: impact of forcing, initial conditions and model errors
Authors: Roulin Emmanuel , Vannitsem Stéphane 
Published: June 2014

AbstractThe impact of errors in the forcing, errors in the model structure and parameters, and errors in the initial conditions is investigated in a simple hydrological ensemble prediction system. The hydrological model is based on an input nonlinearity connected with a linear transfer function and forced by precipitation forecasts from the European Centre for Medium‐Range Weather Forecast (ECMWF) Ensemble Prediction System (EPS). The post‐processing of the precipitation and/or the streamflow using information from the reforecasts performed by ECMWF is tested. For this purpose, hydrological reforecasts are obtained by forcing the hydrological model with the precipitation from the reforecast data.In the present case study, it is found that the post‐processing of the hydrological ensembles with a statistical model fitted on the hydrological reforecasts improves the verification scores better than the use of post‐processed precipitation ensembles. In the case of large biases in the precipitation, combining the post‐processing of both precipitation and streamflow allows for further improvements. During the winter, errors in the initial conditions have a larger impact on the scores than errors in the model structure as designed in the experiments. Errors in the parameter values are largely corrected with the post‐processing. Copyright © 2014 John Wiley & Sons, Ltd.
Physicochemical properties of newly developed bioactive glass cement and its effects on various cells
Authors: Washio Ayako , Nakagawa Aika , Nishihara Tatsuji , Maeda Hidefumi , Kitamura Chiaki 
Published: June 2014

AbstractBiomaterials used in dental treatments are expected to have favorable properties such as biocompatibility and an ability to induce tissue formation in dental pulp and periapical tissue, as well as sealing to block external stimuli. Bioactive glasses have been applied in bone engineering, but rarely applied in the field of dentistry. In the present study, bioactive glass cement for dental treatment was developed, and then its physicochemical properties and effects on cell responses were analyzed. To clarify the physicochemical attributes of the cement, field emission scanning electron microscopy, X‐ray diffraction, and pH measurement were carried out. Cell attachment, morphology, and viability to the cement were also examined to clarify the effects of the cement on odontoblast‐like cells (KN‐3 cells), osteoblastic cells (MC3T3‐E1 cells), human periodontal ligament stem/progenitor cells and neuro‐differentiative cells (PC‐12 cells). Hydroxyapatite‐like precipitation was formed on the surface of the hardened cement and the pH level changed from pH10 to pH9, then stabilized in simulate body fluid. The cement had no cytotxic effects on these cells, and particulary induced process elongation of PC‐12 cells. Our results suggest that the newly developed bioactive glass cement have capability of the application in dental procedures as bioactive cement. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 373–380, 2015.