bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental evidence for seismically initiated gas bubble nucleation and growth in groundwater as a mechanism for coseismic borehole water level rise and remotely triggered seismicity
Authors: Crews Jackson B. , Cooper Clay A. 
Published: August 2014

AbstractChanges in borehole water levels and remotely triggered seismicity occur in response to near and distant earthquakes at locations around the globe, but the mechanisms for these phenomena are not well understood. Experiments were conducted to show that seismically initiated gas bubble growth in groundwater can trigger a sustained increase in pore fluid pressure consistent in magnitude with observed coseismic borehole water level rise, constituting a physically plausible mechanism for remote triggering of secondary earthquakes through the reduction of effective stress in critically loaded geologic faults. A portion of the CO2 degassing from the Earth's crust dissolves in groundwater where seismic Rayleigh and P waves cause dilational strain, which can reduce pore fluid pressure to or below the bubble pressure, triggering CO2 gas bubble growth in the saturated zone, indicated by a spontaneous buildup of pore fluid pressure. Excess pore fluid pressure was measured in response to the application of 0.1–1.0 MPa, 0.01–0.30 Hz confining stress oscillations to a Berea sandstone core flooded with initially subsaturated aqueous CO2, under conditions representative of a confined aquifer. Confining stress oscillations equivalent to the dynamic stress of the 28 June 1992 Mw 7.3 Landers, California, earthquake Rayleigh wave as it traveled through the Long Valley caldera, and Parkfield, California, increased the pore fluid pressure in the Berea core by an average of 36 ± 15 cm and 23 ± 15 cm of equivalent freshwater head, respectively, in agreement with 41.8 cm and 34 cm rises recorded in wells at those locations.
Simulating extreme total water levels using a time‐dependent, extreme value approach
Authors: Serafin Katherine A. , Ruggiero Peter 
Published: August 2014

AbstractCoastal flood hazard zones and the design of coastal defenses are often devised using the maximum recorded water level or a “design” event such as the 100 year return level, usually projected from observed extremes. Despite technological advances driving more consistent instrumental records of waves and water levels, the observational record may be short, punctuated with intermittent gaps, and vary in quality. These issues in the record often preclude accurate and robust estimates of extreme return level events. Here we present a total water level full simulation model (TWL‐FSM) that simulates the various components of TWLs (waves, tides, and nontidal residuals) in a Monte Carlo sense, taking into account conditional dependencies that exist between the various components. Extreme events are modeled using nonstationary extreme value distributions that include seasonality and climate variability. The resulting synthetic TWLs allow for empirical extraction of return level events and the ability to more robustly estimate and assess present‐day flood and erosion hazards. The approach is demonstrated along a northern Oregon, USA littoral cell but is applicable to beaches anywhere wave and water level records or hindcasts are available. Simulations result in extreme 100 year TWL return levels as much as 90 cm higher than those extrapolated from the “observational” record. At the Oregon site, this would result in 30% more coastal flooding than the “observational” 100 year TWL return level projections. More robust estimates of extreme TWLs and tighter confidence bounds on return level events can aid coastal engineers, managers, and emergency planners in evaluating exposure to hazards.
Water mass analysis of the Coral Sea through an Optimum Multiparameter method
Authors: Gasparin Florent , Maes Christophe , Sudre Joel , Garcon Veronique , Ganachaud Alexandre 
Published: August 2014

AbstractA water mass analysis of the Coral Sea thermocline waters provides a description of their distribution, pathways and mixture based on recent oceanographic cruises in this region of strong western boundary currents. The Optimum Multiparameter method is used to determine the relative contribution of core water masses based on their measured temperature, salinity and dissolved oxygen. The thermocline waters, carried by the broad South Equatorial Current (SEC), are essentially composed of four core water masses of different origins. Coming from the south, the South Pacific Tropical Water South (SPTWS, σ = 25.3 kg m−3) and the Western South Pacific Central Water (WSPCW, σ = 26.3 kg m−3) enter the Coral Sea by the channel between the island of New Caledonia and the Vanuatu archipelago. Coming from the north, the South Pacific Tropical Water North (SPTWN, σ = 24.5 kg m−3) and the Pacific Equatorial Water (PEW, σ = 26.3 kg m−3) flow north of Vanuatu. The upper thermocline water that exits the Coral Sea equatorward, is mainly composed of SPTWN carried by the New Guinea Coastal Undercurrent. In contrast, upper thermocline waters exiting the Coral Sea poleward, in the East Australian Current, is dominated by SPTWS. The relative contributions are different in the lower thermocline where WSPCW dominates both western boundary currents. This refined description is consistent with the dynamics of the main currents, with a very strong depth dependence in the partitioning of incoming SEC waters.
Estimating ice particle scattering properties using a modified Rayleigh‐Gans approximation
Authors: Lu Yinghui , Clothiaux Eugene E. , Aydin Kültegin , Verlinde Johannes 
Published: August 2014

AbstractA modification to the Rayleigh‐Gans approximation is made that includes self‐interactions between different parts of an ice crystal, which both improves the accuracy of the Rayleigh‐Gans approximation and extends its applicability to polarization‐dependent parameters. This modified Rayleigh‐Gans approximation is both efficient and reasonably accurate for particles with at least one dimension much smaller than the wavelength (e.g., dendrites at millimeter or longer wavelengths) or particles with sparse structures (e.g., low‐density aggregates). Relative to the Generalized Multiparticle Mie method, backscattering reflectivities at horizontal transmit and receive polarization (HH) (ZHH) computed with this modified Rayleigh‐Gans approach are about 3 dB more accurate than with the traditional Rayleigh‐Gans approximation. For realistic particle size distributions and pristine ice crystals the modified Rayleigh‐Gans approach agrees with the Generalized Multiparticle Mie method to within 0.5 dB for ZHH whereas for the polarimetric radar observables differential reflectivity (ZDR) and specific differential phase (KDP) agreement is generally within 0.7 dB and 13%, respectively. Compared to the A‐DDA code, the modified Rayleigh‐Gans approximation is several to tens of times faster if scattering properties for different incident angles and particle orientations are calculated. These accuracies and computational efficiencies are sufficient to make this modified Rayleigh‐Gans approach a viable alternative to the Rayleigh‐Gans approximation in some applications such as millimeter to centimeter wavelength radars and to other methods that assume simpler, less accurate shapes for ice crystals. This method should not be used on materials with dielectric properties much different from ice and on compact particles much larger than the wavelength.
Rapid photochemical equilibration of isotope bond ordering in O2
Authors: Yeung Laurence Y. , Ash Jeanine L. , Young Edward D. 
Published: August 2014

AbstractThe abundances of 18O18O and 17O18O in the atmosphere were recently found to be enriched relative to the stochastic distribution of isotopes in O2. The enrichment is believed to arise from O(3P) + O2 isotope exchange reactions, which reorder the isotopes in O2 to a distribution that favors bonds between heavy isotopes. Theoretical predictions and laboratory experiments suggest that the reordered distribution of isotopes should reflect internal isotopic equilibrium, but a laboratory test of this hypothesis for the complete O2 isotopologue system has not yet been realized. Here we use a simple photochemical experiment that reorders the isotopes in O2 at temperatures between 200 K and 350 K. Using simultaneous measurements of five O2 isotopologues, we show that O(3P) + O2 reorders the isotopes in O2 to isotopic equilibrium. Furthermore, we use this scheme to calibrate measurements of isotopic ordering in samples of O2, obtaining Δ36 and Δ35 values within ±0.1‰. Measurements of atmospheric O2 sampled at the University of California, Los Angeles, from 2012 to 2014 have mean values of Δ36 = 1.97 ± 0.07‰ and Δ35 = 1.0 ± 0.1‰ (2 SE; n = 23), with no detectable long‐term trend. These measurements are consistent with values for air reported earlier, but with a threefold to fourfold improvement in precision. Together, the experiments and observations support the case that isotopic ordering in tropospheric O2 is altered by O(3P) + O2; however, they also suggest that tropospheric Δ36 and Δ35 values do not reflect complete isotopic equilibration in the troposphere. Isotopic ordering in atmospheric O2 likely reflects the decadal‐scale balance of stratospheric and tropospheric air masses modulated by variations in tropospheric photochemistry and convection.
Mathematical analysis of the Saint‐Venant‐Hirano model for mixed‐sediment morphodynamics
Authors: Stecca G. , Siviglia A. , Blom A. 
Published: August 2014

AbstractSediment of different size are transported in rivers under the action of flow. The first and still most popular sediment continuity model able to deal with mixed sediment is the so‐called active layer model proposed by Hirano (1971, 1972). In this paper, we consider the one‐dimensional hydromorphodynamic model given by the Saint‐Venant equations for free‐surface flow coupled with the active layer model. We perform a mathematical analysis of this model, extending the previous analysis by Ribberink (1987), including full unsteadiness and grainsize selectivity of the transported load by explicitly considering multiple sediment fractions. The presence of multiple fractions gives rise to distinct waves traveling in the downstream direction, for which we provide an analytical approximation of propagation velocity under any Froude regime. We finally investigate the role of different waves in advecting morphodynamic changes through the domain. To this aim, we implement an analytical linearized solver to analyze the propagation of small‐amplitude perturbations of the bed elevation and grainsize distribution of the active layer as described by the system of governing equations. We find that initial gradients in the grainsize distribution of the active layer are able to trigger significant bed variations, which propagate in the downstream direction at faster pace than the “bed” wave arising from the unisize‐sediment Saint‐Venant‐Exner model. We also verify that multiple “sorting” waves carry multiple associated bed perturbations, traveling at different speeds.
Brief Communication: Lactase persistence and dairy intake in Mapuche and Mestizo populations from southern Chile
Authors: Fernández Catalina I. , Flores Sergio V. 
Published: August 2014

ABSTRACTLactase persistence (LP) occurs at a very low frequency in indigenous populations from Latin America, offering an opportunity to understand the relationship between this genetic trait and patterns of dairy consumption. Here, the frequency of LP is analyzed from Mapuche and ‐an adjacent‐ mestizo population inhabiting the Araucanía region. In addition to genotyping for LP, participants were surveyed in relation to general perception and consumption habits of dairy products. Low LP frequency (10%) and very low dairy intake was found among the Mapuche population as compared with Mestizo populations inhabiting Chile. The survey reported that the main reasons for avoidance of dairy were the gastrointestinal symptoms after dairy intake and cultural dietary habits. The interaction between low LP genotype frequency, low dairy intake, and sociocultural determinants is here discussed in the light of their potential health outcomes. Am J Phys Anthropol 155:482–487, 2014. © 2014 Wiley Periodicals, Inc.
Isotopic studies of the diet of the people of the coast of British Columbia
Authors: Schwarcz Henry P. , Chisholm Brian S. , Burchell Meghan 
Published: August 2014

ABSTRACTIn 1982, Chisholm et al. used δ13C data for human burials from shell midden sites widely distributed on the coast of British Columbia (BC) to show the extreme dependence of these individuals on high trophic level marine consumers, principally salmon and marine mammals. Here, we present previously unpublished analyses of δ15N for some of the same individuals as well as δ13C data for additional individuals. Nitrogen isotope data show that the diet was dominated by high trophic level marine fauna including carnivorous fish and marine mammals. Although most burials were found in shell middens, marine mollusks made up of only a minor component of diet. The data for δ13C demonstrate that terrestrial faunal foods are undetectable in the diet of the majority of individuals, and seldom constitute more than 10% of the dietary protein of individuals living on the coast although terrestrial fauna were widely available as a potential source of protein. This dietary pattern of exclusion of land‐based animals from their diet persisted for almost 6,000 years along a wide expanse of coastline. In contrast, people from the BC interior (100 km or more from the coast) consumed a mixed diet of terrestrial and marine foods including spawning salmon. Am J Phys Anthropol 155:460–468, 2014. © 2014 Wiley Periodicals, Inc.
Bioarcheology has a “health” problem: Conceptualizing “stress” and “health” in bioarcheological research
Authors: Temple Daniel H. , Goodman Alan H. 
Published: August 2014

ABSTRACTThis article provides a critical historical overview of the stress concept in bioarcheological research and critically evaluates the term “health” in reference to skeletal samples. Stress has a considerable history in 20th century physiological research, and the term has reached a critical capacity of meaning. Stress was operationalized around a series of generalized physiological responses that were associated with a deviation from homeostasis. The term was incorporated into anthropological research during the mid‐20th century, and further defined in bioarcheological context around a series of skeletal indicators of physiological disruption and disease. Emphases on stress became a predominate area of research in bioarcheology, and eventually, many studies utilized the terms “health” and “stress” interchangeably as part of a broader, problem‐oriented approach to evaluating prehistoric population dynamics. Use of the term “health” in relation to skeletal samples is associated with the intellectual history of bioarcheological research, specifically influences from cultural ecology and processualist archeology and remains problematic for two reasons. First, health represents a comprehensive state of well‐being that includes physiological status and individual perception, factors that cannot be readily observed in skeletal samples. Second, the categorization of populations into relative levels of health represents a typological approach, however unintentional. This article advocates for the integration of methodological and theoretical advances from human biology and primatology, while simultaneously incorporating the theoretical constructs associated with social epidemiology into bioarcheological research. Such an approach will significantly increase the applicability of bioarcheological findings to anthropological and evolutionary research, and help realize the goal of a truly relevant bioarcheological paradigm. Am J Phys Anthropol 155:186–191, 2014. © 2014 Wiley Periodicals, Inc.
Phosphonated Near‐Infrared Fluorophores for Biomedical Imaging of Bone
Authors: Hyun Hoon , Wada Hideyuki , Bao Kai , Gravier Julien , Yadav Yogesh , Laramie Matt , Henary Maged , Frangioni John V. , Choi Hak Soo 
Published: August 2014

AbstractThe conventional method for creating targeted contrast agents is to conjugate separate targeting and fluorophore domains. A new strategy is based on the incorporation of targeting moieties into the non‐delocalized structure of pentamethine and heptamethine indocyanines. Using the known affinity of phosphonates for bone minerals in a model system, two families of bifunctional molecules that target bone without requiring a traditional bisphosphonate are synthesized. With peak fluorescence emissions at approximately 700 or 800 nm, these molecules can be used for fluorescence‐assisted resection and exploration (FLARE) dual‐channel imaging. Longitudinal FLARE studies in mice demonstrate that phosphonated near‐infrared fluorophores remain stable in bone for over five weeks, and histological analysis confirms their incorporation into the bone matrix. Taken together, a new strategy for creating ultra‐compact, targeted near‐infrared fluorophores for various bioimaging applications is described.
Reconfigurable Swarms of Nematic Colloids Controlled by Photoactivated Surface Patterns
Authors: Hernàndez‐Navarro Sergi , Tierno Pietro , Farrera Joan Anton , Ignés‐Mullol Jordi , Sagués Francesc 
Published: August 2014

AbstractDifferent phoretic driving mechanisms have been proposed for the transport of solid or liquid microscopic inclusions in integrated chemical processes. It is now shown that a substrate that was chemically modified with photosensitive self‐assembled monolayers enables the direct control of the assembly and transport of large ensembles of micrometer‐sized particles and drops that were dispersed in a thin layer of anisotropic fluid. This strategy separates particle driving, which was realized by AC electrophoresis, and steering, which was achieved by elastic modulation of the nematic host fluid. Inclusions respond individually or in collective modes following arbitrary reconfigurable paths that were imprinted by irradiation with UV or blue light. Relying solely on generic material properties, the proposed procedure is versatile enough for the development of applications that involve either inanimate or living materials.
Copper‐Mediated C6‐Selective Dehydrogenative Heteroarylation of 2‐Pyridones with 1,3‐Azoles
Authors: Odani Riko , Hirano Koji , Satoh Tetsuya , Miura Masahiro 
Published: August 2014

AbstractA copper‐mediated C6‐selective dehydrogenative heteroarylation of 2‐pyridones with 1,3‐azoles has been developed. The reaction proceeded smoothly by twofold CH cleavage even in the absence of noble‐metal catalysts. The observed site selectivity was directed by a pyridyl substituent on the nitrogen atom of the pyridone ring. This directing group was readily removed after the coupling event, thus leading to 2‐pyridone derivatives with a free NH group. Moreover, in some cases, catalytic turnover of the Cu salt was also possible with the ideal terminal oxidant: molecular oxygen in air.
Progress towards Bioorthogonal Catalysis with Organometallic Compounds
Authors: Völker Timo , Dempwolff Felix , Graumann Peter L. , Meggers Eric 
Published: August 2014

AbstractThe catalysis of bioorthogonal transformations inside living organisms is a formidable challenge—yet bears great potential for future applications in chemical biology and medicinal chemistry. We herein disclose highly active organometallic ruthenium complexes for bioorthogonal catalysis under biologically relevant conditions and inside living cells. The catalysts uncage allyl carbamate protected amines with unprecedented high turnover numbers of up to 270 cycles in the presence of water, air, and millimolar concentrations of thiols. By live‐cell imaging of HeLa cells and with the aid of a caged fluorescent probe we could reveal a rapid development of intense fluorescence within the cellular cytoplasm and therefore support the proposed bioorthogonality of the catalysts. In addition, to illustrate the manifold applications of bioorthogonal catalysis, we developed a method for catalytic in‐cell activation of a caged anticancer drug, which efficiently induced apoptosis in HeLa cells.
Revealing the Distribution of the Atoms within Individual Bimetallic Catalyst Nanoparticles
Authors: Felfer Peter , Benndorf Paul , Masters Anthony , Maschmeyer Thomas , Cairney Julie M. 
Published: August 2014

AbstractTo be able to correlate the catalytic properties of nanoparticles with their structure, detailed knowledge about their make‐up on the atomic level is required. Herein, we demonstrate how atom‐probe tomography (APT) can be used to quantitatively determine the three‐dimensional distribution of atoms within a Au@Ag nanoparticle with near‐atomic resolution. We reveal that the elements are not evenly distributed across the surface and that this distribution is related to the surface morphology and residues from the particle synthesis.
Double‐Clicking Peptides onto Phosphorothioate Oligonucleotides: Combining Two Proapoptotic Agents in One Molecule
Authors: Abendroth Frank , Seitz Oliver 
Published: August 2014

AbstractDescribed here is a method for the conjugation of phosphorothioate oligonucleotides (PSOs) with peptides. PSOs are key to antisense technology. Peptide–PSO conjugates may improve target specificity, tissue distribution, and cellular uptake of PSOs. However, the highly nucleophilic phosphorothioate structure poses a challenge to conjugation chemistry. Herein, we introduce a new method which involves a sequence of oxime ligation and strain‐promoted [2+3] cycloaddition. The usefulness of the method was demonstrated in the synthesis of peptide–PSO conjugates that targeted two suppressors of both the intrinsic and the extrinsic pathway of apoptosis. It is shown that the activity of a PSO sequence targeted against mRNA from c‐Flip can be enhanced by conjugation with a peptide mimetic designed to inhibit the X‐linked inhibitor of apoptosis protein (XIAP).
Hierarchical Self‐Assembly of Supramolecular Hydrophobic Metallacycles into Ordered Nanostructures
Authors: Zhang Jing , Marega Riccardo , Chen Li‐Jun , Wu Nai‐Wei , Xu Xing‐Dong , Muddiman David C. , Bonifazi Davide , Yang Hai‐Bo 
Published: August 2014

AbstractWe describe herein the hierarchical self‐assembly of discrete supramolecular metallacycles into ordered fibers or spherical particles through multiple noncovalent interactions. A new series of well‐defined metallacycles decorated with long alkyl chains were obtained through metal–ligand interactions, which were capable of aggregating into ordered fibroid or spherical nanostructures on the surface, mostly driven by hydrophobic interactions. In‐depth studies indicated that the morphology diversity was originated from the structural information encoded in the metallacycles, including the number of alkyl chains and their spatial orientation. Interestingly, the morphology of the metallacycle aggregates could be tuned by changing the solvent polarity. These findings are of special significance since they provide a simple yet highly controllable approach to prepare ordered and tunable nanostructures from small building blocks by means of hierarchical self‐assembly.