bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contrasting biogeochemical cycles of cobalt in the surface western Atlantic Ocean
Authors: Dulaquais Gabriel , Boye Marie , Middag Rob , Owens Stephanis , Puigcorbe Viena , Buesseler Ken , Masqué Pere , de Baar Hein J. W. , Carton Xavier 
Published: October 2014

AbstractDissolved cobalt (DCo; <0.2 µm; 14 to 93 pM) and the apparent particulate cobalt (PCo; >0.2 µm; <1 to 15 pM) were determined in the upper water column (<1000 m) of the western Atlantic Ocean along the GEOTRACES‐A02 section (64°N to 50°S). The lowest DCo concentrations, typical of a nutrient‐type distribution were observed in surface waters of the subtropical domains. Strong linear relationships between DCo and phosphate (P) as well as meridional gradients of decreasing DCo from high latitudes were characterized and both linked to the Co biological requirement. External sources such as the Amazon and the atmospheric deposition were found to contribute significantly (>10%) to the DCo stock of the mixed layer in the equatorial and north subtropical domains. Biotic and abiotic processes as well as the physical terms involved in the biogeochemical cycle of Co were defined and estimated. This allowed establishing the first global budget of DCo for the upper 100 m in the western Atlantic. The biological DCo uptake flux was the dominant sink along the section, as reflected by the overall nutrient‐type behavior of DCo. The regeneration varied widely within the different biogeochemical domains, accounting for 10% of the DCo‐uptake rate in the subarctic gyre and for up to 85% in southern subtropical domain. These findings demonstrated that the regeneration is likely the prevailing source of DCo in the surface waters of the western Atlantic, except in the subpolar domains where physically driven sources can sustain the DCo biological requirement.
Chemical compositions of sulfate and chloride salts over the last termination reconstructed from the Dome Fuji ice core, inland Antarctica
Authors: Oyabu Ikumi , Iizuka Yoshinori , Uemura Ryu , Miyake Takayuki , Hirabayashi Motohiro , Motoyama Hideaki , Sakurai Toshimitsu , Suzuki Toshitaka , Hondoh Takeo 
Published: October 2014

AbstractThe flux and chemical composition of aerosols impact the climate. Antarctic ice cores preserve the record of past atmospheric aerosols, providing useful information about past atmospheric environments. However, few studies have directly measured the chemical composition of aerosol particles preserved in ice cores. Here we present the chemical compositions of sulfate and chloride salts from aerosol particles in the Dome Fuji ice core. The analysis method involves ice sublimation, and the period covers the last termination, 25.0–11.0 thousand years before present (kyr B.P.), with a 350 year resolution. The major components of the soluble particles are CaSO4, Na2SO4, and NaCl. The dominant sulfate salt changes at 16.8 kyr B.P. from CaSO4, a glacial type, to Na2SO4, an interglacial type. The sulfate salt flux (CaSO4 plus Na2SO4) inversely correlates with δ18O in Dome Fuji over millennial timescales. This correlation is consistent with the idea that sulfate salt aerosols contributed to the last deglacial warming of inland Antarctica by reducing the aerosol indirect effect. Between 16.3 and 11.0 kyr B.P., the presence of NaCl suggests that winter atmospheric aerosols are preserved. A high NaCl/Na2SO4 fraction between 12.3 and 11.0 kyr B.P. indicates that the contribution from the transport of winter atmospheric aerosols increased during this period.
Relative role of tropical SST forcing in the 1990s periodicity change of the Pacific‐Japan pattern interannual variability
Authors: Chen Xiaolong , Zhou Tianjun 
Published: October 2014

AbstractThe interannual variability and periodicity change of the Pacific‐Japan (PJ) pattern during 1979–2008 are investigated using observation/reanalysis data sets and Atmospheric Model Intercomparison Project (AMIP)‐runs of 20 atmospheric general circulation models (AGCMs). The PJ pattern is represented by the first leading empirical orthogonal function mode (EOF1) of 850 hPa vorticity over the East Asian and western North Pacific regions in boreal summer. The leading principal component (PC1) is characterized by a dominant periodicity of 4–5 (2–3) years before (after) 1993. Analyses reveal that the 4–5 year periodicity may be forced by sea surface temperature anomalies (SSTAs) in the tropical western Indian Ocean (IO). In contrast, the 2–3 year periodicity is the combined effect of the SSTAs surrounding the maritime continent (MC) and in the central Pacific (CP), in which the latter may play a primary role. AGCMs which reasonably capture above responses are inclined to have higher PC1 skills and vice versa. To confirm the source of forcing diagnosed based on AMIP simulations, a series of sensitivity experiments is done using the CAM4 model. Without SST variation in the MC or CP after 1993, the 2–3 year variability of the PJ pattern weakens. The periodicity change of PJ variability around 1993 is shown to be correlated with the change of El Niño–Southern Oscillation (ENSO) variability. Analysis of observations indicates that the anomalous summertime SST and circulation patterns over the Indo‐Pacific region correspond to decaying ENSO phase before 1993 and to developing phase after 1993.
Correcting precipitation feature location in general circulation models
Authors: Levy Adam A. L. , Jenkinson Mark , Ingram William , Allen Myles 
Published: October 2014

AbstractThere is much evidence that precipitation responses to global warming involve wet regions becoming wetter and dry regions drier. This presents challenges for the interpretation of projections from general circulation models (GCMs) which have substantial biases in the location of precipitation features. While improving GCM simulated precipitation is the most desirable solution, adaptation and mitigation decisions must be made with the models already available. Many techniques have been developed to correct biases in grid point precipitation intensities, but few have been introduced to correct for location biases. Here, we describe a new technique for correcting the spatial and seasonal location of climatological precipitation features. We design this technique to respect the geometry of the problem (spherical spatial dimensions, with cyclic seasons), while conserving either precipitation intensities, or integrated precipitation amount. We discuss the mathematical basis of the technique and investigate its behaviour in different regimes. We find that the resulting warps depend smoothly on the most influential parameter, which determines the balance between smoothness and closeness of fit. We show that the technique is capable of removing more than half the RMS error in a model's climatology, obtaining consistently better results when conserving integrated precipitation. To demonstrate the ability of the new technique to improve simulated precipitation changes, we apply our transformations to historical anomalies and show that RMS error is reduced relative to GPCP's anomalies by approximately 10% for both types of warp. This verifies that errors in precipitation changes can be reduced by correcting underlying location errors in a GCM's climatology.
Detection of Organic Colorants in Historical Painting Layers Using UV Laser Ablation Surface‐Enhanced Raman Microspectroscopy
Authors: Cesaratto Anna , Leona Marco , Lombardi John R. , Comelli Daniela , Nevin Austin , Londero Pablo 
Published: October 2014

AbstractSurface‐enhanced Raman spectroscopy (SERS) has been increasingly used in the study of works of art to identify organic pigments and dyes in paintings, which (depending on the material) are difficult or not possible to detect by other current methods. The application of SERS to the study of paintings has been limited, however, by the lack of a sampling approach with sufficient sensitivity and spatial resolution. We show that ultraviolet laser ablation (LA) sampling coupled with SERS detection can be successfully used to study paint layers. LA‐SERS permitted the isolation of signals from colorants in individual thin paint layers in sample cross‐sections, avoiding contamination from adjacent layers. These results expand the range of analytical applications of SERS demonstrating how the technique can be used to sensitively detect minor organic components in complex matrices. While this is fundamental for the study of cultural heritage, it is also relevant in other fields such as forensic analysis, food science, and pharmacology.
Copper(I)‐Catalyzed Three‐Component Reaction of Terminal Propargyl Alcohols, Aldehydes, and Amines: Synthesis of 3‐Amino‐2‐pyrones and 2,5‐Dihydrofurans
Authors: Fan Wu , Ma Shengming 
Published: October 2014

AbstractA novel copper(I)‐catalyzed three‐component reaction for the efficient synthesis of 3‐amino‐2‐pyrones and 2,5‐dihydrofurans from propargyl alcohols, aldehydes, and amines has been developed. The starting materials are easily available and the scope of this method is broad. Through mechanistic studies, it is believed that the three‐component reaction consists of an A3‐coupling to propargylic amine, alkyne–allene isomerization, and intramolecular cyclization of the allenol to form a furan. In case of using ethyl glyoxalate as the aldehyde, a ring‐opening, lactonization, and isomerization process affords the 3‐amino‐2‐pyrones.
Conductive composites from polyaniline and polyurethane sulphonate anionomer
Authors: Deka Riblu , Bora Montu Moni , Upadhyaya Madhab , Kakati Dilip Kumar 
Published: October 2014

ABSTRACTThe present work describes the synthesis of conductive composite of polyurethane sulphonate anionomer (PUSA) and para toluene sulphonic acid doped polyaniline (PANI–PTSA). HCl‐doped PANI was synthesized by chemical oxidative polymerization of aniline in HCl, which was converted to PANI–EB by treatment with NH4OH. PTSA doped PANI was synthesized from EB‐PANI by redoping with PTSA solution. PUSA was synthesized from 4, 4′‐diphenylmethanediisocyanate (MDI), polypropylene glycol (PPG), 1,4‐butanediol (BD), and ionic diol SDOL. The composite was prepared by mixing of the solutions of two polymer components in DMF and then solution casting. The products were characterized and analyzed by UV‐Vis and FTIR spectroscopy, thermogravimetry, differential scanning calorimetry and scanning electron microscopy. The conductivity was found to increase by 100 times with concomitant decrease in percolation threshold when polyurethane was replaced by PUSA in the composite for the same amount of polyaniline. The composite film was thermally stable upto ∼300°C. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41600.
Collaborative machine scheduling: Challenges of individually optimizing behavior
Authors: Lang Fabian , Fink Andreas 
Published: October 2014

SummaryCollaborative interorganizational systems is a relevant and promising research domain. When autonomous agents associated with different enterprises negotiate about rival resources, coordination is a major challenge. As agents are driven by self‐interest and try to maximize their very own objectives, collaborative planning has to account for some challenges. Collaboration, that is, the participation in a common, shared system, may be profitable for an agent, but cooperation, that is, the pursuing of a common goal, may not be. Additionally, information provided by the agents is a fruit of a poisonous tree because the selfish agents have an incentive to lie strategically, which makes the revealed information unreliable and misleading for a central authority. Moreover, the agents might not be willing to reveal information because of privacy concerns. Consequently, there is a need for sophisticated mechanism design in collaborative systems that facilitate the coordination of non‐cooperative agents. This paper deals with rival machine scheduling of one or more homogeneous machines by autonomous agents. Overall objectives are the minimization of the collective total weighted tardiness and Pareto efficient outcomes. We have developed a mediated negotiation protocol drawing on quotas for the acceptance of contract proposals. The protocol ensures that the agents accept sufficient proposals such that they can overcome individual local optima and achieve Pareto superior outcomes. For evaluation purposes, we have conducted several computational experiments. The experiments show that the proposed protocol achieves beneficial outcomes. Copyright © 2014 John Wiley & Sons, Ltd.
Stereocontrolled Construction of the 3,4‐Dihydrothiacarbazol‐2(9H)‐one Skeleton by Using Bifunctional Squaramide‐Catalyzed Cascade Reactions
Authors: Chen Shanren , Pan Jianping , Wang Youming , Zhou Zhenghong 
Published: October 2014

AbstractAn efficient approach for the stereocontrolled construction of the 3,4‐dihydrothiacarbazol‐2(9H)‐one skeleton has been developed. In the presence of a bifunctional squaramide catalyst that was derived fromL‐tert‐leucine, the asymmetric tandem Michael/thiolysis reactions of 9‐methylindoline‐2‐thiones andN‐alkynoylphthalimides proceeded efficiently to furnish the desired 3,4‐dihydrothiacarbazol‐2(9H)‐one derivatives in satisfactory yields with high levels of enantioselectivity (up to 98 % ee).
Cellular uptake and toxicity effects of silver nanoparticles in mammalian kidney cells
Authors: Milić Mirta , Leitinger Gerd , Pavičić Ivan , Zebić Avdičević Maja , Dobrović Slaven , Goessler Walter , Vinković Vrček Ivana 
Published: October 2014

AbstractThe rapid progress and early commercial acceptance of silver‐based nanomaterials is owed to their biocidal activity. Besides embracing the antimicrobial potential of silver nanoparticles (AgNPs), it is imperative to give special attention to the potential adverse health effects of nanoparticles owing to prolonged exposure. Here, we report a detailed study on the in vitro interactions of citrate‐coated AgNPs with porcine kidney (Pk15) cells. As uncertainty remains whether biological/cellular responses to AgNPs are solely as a result of the release of silver ions or whether the AgNPs themselves have toxic effects, we investigated the effects of Ag+ on Pk15 cells for comparison. Next, we investigated the cellular uptake of both AgNPs and Ag+ in Pk15 cells at various concentrations applied. The detected Ag contents in cells exposed to 50 mg l−1 AgNPs and 50 mg l−1 Ag+ were 209 and 25 µg of Ag per 106 cells, respectively. Transmission electron microscopy (TEM) images indicated that the Pk15 cells internalized AgNPs by endocytosis. Both forms of silver, nano and ionic, decreased the number of viable Pk15 cells after 24 h in a dose‐dependent manner. In spite of a significant uptake into the cells, AgNPs had only insignificant toxicity at concentrations lower than 25 mg l−1, whereas Ag+ exhibited a significant decrease in cell viability at one‐fifth of this concentration. The Comet assay suggested that a rather high concentration of AgNP (above 25 mg l−1) is able to induce genotoxicity in Pk15 cells. Further studies must seek deeper understanding of AgNP behavior in biological media and their interactions with cellular membranes. Copyright © 2014 John Wiley & Sons, Ltd.
Weak imposition of essential boundary conditions in the finite element approximation of elliptic problems with non‐matching meshes
Authors: Codina Ramon , Baiges Joan 
Published: October 2014

SummaryIn this work, we propose a method to prescribe essential boundary conditions in the finite element approximation of elliptic problems when the boundary of the computational domain does not match with the element boundaries. The problems considered are the Poisson problem, the Stokes problem, and the Darcy problem, the latter both in the primal and in the dual formulation. The formulation proposed is of variational type. The key idea is to start with the variational form that defines the problem and treat the boundary condition as a constraint. The particular feature is that the Lagrange multiplier is not defined on the boundary where the essential condition needs to be prescribed but is taken as a certain trace of a field defined in the computational domain, either in all of it or just in a region surrounding the boundary. When approximated numerically, this may allow one to condense the DOFs of the new field and end up with a problem posed only in terms of the original unknowns. The nature of the field used to weakly impose boundary conditions depends on the problem being treated. For the Poisson problem, it is a flux; for the Stokes problem, a stress; for the Darcy problem in primal form, a velocity field; and for the Darcy problem in dual form, it is a potential. Copyright © 2014 John Wiley & Sons, Ltd.
Polycondensation of structurally divergent tetraamine monomers with dicarboxylic acids to synthesize polybenzimidazole copolymers for polymer electrolyte membranes
Authors: Maity Sudhangshu , Jana Tushar 
Published: October 2014

AbstractIn our effort to promote 2,6‐bis(3,4‐diaminophenyl)‐4‐phenylpyridine (Py‐TAB) as an alternative tetraamine monomer to conventionally used 3,3′,4,4′‐tetraaminobiphenyl (TAB) for synthesizing readily processable pyridine bridged polybenzimidazoles (Py‐PBIs), two series of random copolymers (PBI‐co‐Py‐PBI) were synthesized by polymerizing Py‐TAB and TAB with isophthalic acid or terephthalic acid to produce meta (mPBI‐co‐mPy‐PBI) and para (pPBI‐co‐pPy‐PBI) connected copolymers, respectively. For the first time in the PBI literature, copolymers were synthesized by varying the relative compositions of tetraamines (TAB and Py‐TAB) in the polymerization feed with a single dicarboxylic acid (DCA) instead of the traditionally used method where two DCAs with variable compositions were polymerized with a single tetraamine. The solubility and hence the processability of the copolymers were improved significantly upon introduction of Py‐PBI in the copolymer. The detailed characterizations of both meta and para series copolymers compellingly established that thermal, chemical and mechanical stabilities can be easily modulated according to need by altering the relative compositions of PBI and Py‐PBI. The phosphoric acid (PA) loading of the copolymers increased gradually with increasing Py‐PBI content since the bulky pyridine moiety facilitated the absorption of PA. The presence of pyridine functionality and a larger PA loading caused a higher proton conductivity of PA doped copolymer membranes. © 2014 Society of Chemical Industry
Spatial distribution and sequential sampling plans for Tuta absoluta (Lepidoptera: Gelechiidae) in greenhouse tomato crops
Authors: Cocco Arturo , Serra Giuseppe , Lentini Andrea , Deliperi Salvatore , Delrio Gavino 
Published: October 2014

AbstractBACKGROUNDThe within‐ and between‐plant distribution of the tomato leafminer, Tuta absoluta (Meyrick), was investigated in order to define action thresholds based on leaf infestation and to propose enumerative and binomial sequential sampling plans for pest management applications in protected crops.RESULTSThe pest spatial distribution was aggregated between plants, and median leaves were the most suitable sample to evaluate the pest density. Action thresholds of 36 and 48%, 43 and 56% and 60 and 73% infested leaves, corresponding to economic thresholds of 1 and 3% damaged fruits, were defined for tomato cultivars with big, medium and small fruits respectively. Green's method was a more suitable enumerative sampling plan as it required a lower sampling effort. Binomial sampling plans needed lower average sample sizes than enumerative plans to make a treatment decision, with probabilities of error of <0.10.CONCLUSIONSThe enumerative sampling plan required 87 or 343 leaves to estimate the population density in extensive or intensive ecological studies respectively. Binomial plans would be more practical and efficient for control purposes, needing average sample sizes of 17, 20 and 14 leaves to take a pest management decision in order to avoid fruit damage higher than 1% in cultivars with big, medium and small fruits respectively. © 2014 Society of Chemical Industry
The Other Side of the Broken Window: A Methodology that Translates Building Permits into an Ecometric of Investment by Community Members
Authors: O’Brien Daniel Tumminelli , Montgomery Barrett W. 
Published: October 2014

AbstractMuch research has focused on physical disorder in urban neighborhoods as evidence that the community does not maintain local norms and spaces. Little attention has been paid to the opposite: indicators of proactive investment in the neighborhood’s upkeep. This manuscript presents a methodology that translates a database of approved building permits into an ecometric of investment by community members, establishing basic content, criteria for reliability, and construct validity. A database from Boston, MA contained 150,493 permits spanning 2.5 years, each record including the property to be modified, permit type, and date issued. Investment was operationalized as the proportion of properties in a census block group that underwent an addition or renovation, excluding larger developments involving the demolition or construction of a building. The reliability analysis found that robust measures could be generated every 6 months, and that longitudinal analysis could differentiate between trajectories across neighborhoods. The validity analysis supported two hypotheses: investment was best predicted by homeownership and median income; and maintained an independent relationship with measures of physical disorder despite controlling for demographics, implying that it captures the other end of a spectrum of neighborhood maintenance. Possible uses for the measure in research and policy are discussed.
Entstehungsmechanismen von Zellmosaiken
Authors: Liehr Thomas 
Published: October 2014

Zusammenfassung
Zellmosaike bilden sich im Zusammenhang mit „nondisjunction“, Translokationen (balanciert oder unbalanciert), nichthomologem „crossing over“ oder sonstigen chromosomalen oder subchromosomalen „rearrangements“ aus, aber auch durch kompletten oder gewebsspezifischen Chimärismus. Am bekanntesten und häufigsten nachgewiesen sind Zellmosaike, die auf Aneuploidien beruhen, während über die Häufigkeit von submikroskopischen, nur molekulargenetisch oder zytogenetisch nachweisbaren, aber niedriggradigen Zellmosaiken nur wenig bekannt ist. Als Grundlage für die Entstehung von Zellmosaiken gelten „Trisomic“- und/oder „Monosomic-rescue“-Vorgänge. Auch „replikative Fehler“ oder „Endoreduplikation“ einzelner oder mehrere Chromosomen, Isochromosomenbildung oder postzygotisches „non-homologous crossing-over“ werden als Entstehungsmechanismen von Zellmosaiken in der Literatur genannt. Insgesamt ist jedoch festzustellen, dass praktisch alle bekannten Modelle zur Mosaikentstehung bislang auf der deskriptiven Ebene verharren. Ein grundlegendes Verständnis über die tatsächlich z. B. beim Trisomic oder Monosomic rescue ablaufenden Vorgänge ist derzeit mangels Daten nicht vorhanden.