bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bivalve shell horizons in seafloor pockmarks of the last glacial‐interglacial transition: a thousand years of methane emissions in the Arctic Ocean
Authors: Ambrose William G. , Panieri Giuliana , Schneider Andrea , Plaza‐Faverola Andreia , Carroll Michael L. , Åström Emmelie K. L. , Locke William L. , Carroll JoLynn 
Published: November 2015

AbstractWe studied discrete bivalve shell horizons in two gravity cores from seafloor pockmarks on the Vestnesa Ridge (∼1200 m water depth) and western Svalbard (79°00′ N, 06°55′ W) to provide insight into the temporal and spatial dynamics of seabed methane seeps. The shell beds, dominated by two genera of the family Vesicomyidae: Phreagena s.l. and Isorropodon sp., were 20–30 cm thick and centered at 250–400 cm deep in the cores. The carbon isotope composition of inorganic (δ13C from −13.02‰ to +2.36‰) and organic (δ13C from −29.28‰ to −21.33‰) shell material and a two‐end member mixing model indicate that these taxa derived between 8% and 43% of their nutrition from chemosynthetic bacteria. In addition, negative δ13C values for planktonic foraminifera (−6.7‰ to −3.1‰), concretions identified as methane‐derived authigenic carbonates, and pyrite‐encrusted fossil worm tubes at the shell horizons indicate a sustained paleo‐methane seep environment. Combining sedimentation rates with 14C ages for bivalve material from the shell horizons, we estimate the horizons persisted for about 1000 years between approximately 17,707 and 16,680 years B.P. (corrected). The seepage event over a 1000 year time interval was most likely associated with regional stress‐related faulting and the subsequent release of overpressurized fluids.
Low‐frequency waves in the Martian magnetosphere and their response to upstream solar wind driving conditions
Authors: Ruhunusiri Suranga , Halekas J. S. , Connerney J. E. P. , Espley J. R. , McFadden J. P. , Larson D. E. , Mitchell D. L. , Mazelle C. , Jakosky B. M. 
Published: November 2015

AbstractWe characterize low‐frequency plasma waves in the Martian magnetosphere and in the upstream region by using transport ratios. To compute the transport ratios, we use Mars Atmosphere and Volatile EvolutioN mission's (MAVEN) solar wind ion analyzer and suprathermal and thermal ion composition instrument measurements of the ion moments and the magnetometer measurements of the magnetic field. We find that the Alfvén waves are the most dominant wave mode in the upstream region and the magnetosheath. Fast waves are found frequently near the bow shock and the magnetic pileup boundary. Mirror and slow waves, on the other hand, occur much less frequently. We also find that the Alfvén and fast wave occurrences vary dominantly near the bow shock in response to the solar wind dynamic pressure.
Comparison of model predictions for the composition of the ionosphere of Mars to MAVEN NGIMS data
Authors: Withers Paul , Vogt Marissa , Mayyasi Majd , Mahaffy Paul , Benna Mehdi , Elrod Meredith , Bougher Stephen , Dong Chuanfei , Chaufray Jean‐Yves , Ma Yingjuan , Jakosky Bruce 
Published: November 2015

AbstractPrior to the arrival of the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft at Mars, the only available measurements of the composition of the planet's ionosphere were those acquired by the two Viking Landers during their atmospheric entries. Many numerical models of the composition of the ionosphere of Mars have been developed, but these have only been validated for species, altitudes, and conditions for which Viking data exist. Here we compare the ionospheric composition and structure predicted by 10 ionospheric models at solar zenith angles of 45–60° against ion density measurements acquired by the MAVEN Neutral Gas and Ion Mass Spectrometer (NGIMS). The most successful models included three‐dimensional plasma transport driven by interactions with the surrounding space environment but had relatively simple ionospheric chemistry.
Ionospheric plasma density variations observed at Mars by MAVEN/LPW
Authors: Andrews D. J. , Andersson L. , Delory G. T. , Ergun R. E. , Eriksson A. I. , Fowler C. M. , McEnulty T. , Morooka M. W. , Weber T. , Jakosky B. M. 
Published: November 2015

AbstractWe report on initial observations made by the Langmuir Probe and Waves relaxation soundingexperiment on board the NASA Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. These measurements yield the ionospheric thermal plasma density, and we use these data here for an initial survey of its variability. Studying orbit‐to‐orbit variations, we show that the relative variability of the ionospheric plasma density is lowest at low altitudes near the photochemical peak, steadily increases toward higher altitudes and sharply increases as the spacecraft crosses the terminator and moves into the nightside. Finally, despite the small volume of data currently available, we show that a clear signature of the influence of crustal magnetic fields on the thermal plasma density fluctuations is visible. Such results are consistent with previously reported remote measurements made at higher altitudes, but crucially, here we sample a new span of altitudes between ∼130 and ∼300 km using in situ techniques.
First results of the MAVEN magnetic field investigation
Authors: Connerney J. E. P. , Espley J. R. , DiBraccio G. A. , Gruesbeck J. R. , Oliversen R. J. , Mitchell D. L. , Halekas J. , Mazelle C. , Brain D. , Jakosky B. M. 
Published: November 2015

AbstractTwo Mars Atmosphere and Volatile EvolutioN magnetic field sensors sample the ambient magnetic field at the outer edge of each solar array. We characterized relatively minor spacecraft‐generated magnetic fields using in‐flight subsystem tests and spacecraft maneuvers. Dynamic spacecraft fields associated with the power subsystem (≤1 nT) are compensated for using spacecraft engineering telemetry to identify active solar array circuits and monitor their electrical current production. Static spacecraft magnetic fields are monitored using spacecraft roll maneuvers. Accuracy of measurement of the environmental magnetic field is demonstrated by comparison with field directions deduced from the symmetry properties of the electron distribution function measured by the Solar Wind Electron Analyzer. We map the bow shock, magnetic pileup boundary, the V × B convection electric field and ubiquitous proton cyclotron, and 1 Hz waves in the ion foreshock region.
Multifluid MHD study of the solar wind interaction with Mars' upper atmosphere during the 2015 March 8th ICME event
Authors: Dong Chuanfei , Ma Yingjuan , Bougher Stephen W. , Toth Gabor , Nagy Andrew F. , Halekas Jasper S. , Dong Yaxue , Curry Shannon M. , Luhmann Janet G. , Brain David , Connerney Jack E. P. , Espley Jared , Mahaffy Paul , Benna Mehdi , McFadden James P. , Mitchell David L. , DiBraccio Gina A. , Lillis Robert J. , Jakosky Bruce M. , Grebowsky Joseph M. 
Published: November 2015

AbstractWe study the solar wind interaction with the Martian upper atmosphere during the 8 March 2015 interplanetary coronal mass ejection (ICME) by using a global multifluid MHD model. Comparison of the simulation results with observations from Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft shows good agreement. The total ion escape rate is increased by an order of magnitude, from 2.05 × 1024 s−1 (pre‐ICME phase) to 2.25 × 1025 s−1 (ICME sheath phase), during this time period. Two major ion escape channels are illustrated: accelerated pickup ion loss through the dayside plume and ionospheric ion loss through the nightside plasma wake region. Interestingly, the tailward ion loss is significantly increased at the ejecta phase. Both bow shock and magnetic pileup boundary (BS and MPB) locations are decreased from (1.2RM, 1.57RM) at the pre‐ICME phase to (1.16RM, 1.47RM), respectively, during the sheath phase along the dayside Mars‐Sun line. Furthermore, both simulation and observational results indicate that there is no significant variation in the Martian ionosphere (at altitudes ≲ 200 km, i.e., the photochemical region) during this event.
How did ocean warming affect Australian rainfall extremes during the 2010/2011 La Niña event?
Authors: Ummenhofer Caroline C. , Sen Gupta Alexander , England Matthew H. , Taschetto Andréa S. , Briggs Peter R. , Raupach Michael R. 
Published: November 2015

AbstractExtreme rainfall conditions in Australia during the 2010/2011 La Niña resulted in devastating floods claiming 35 lives, causing billions of dollars in damages, and far‐reaching impacts on global climate, including a significant drop in global sea level and record terrestrial carbon uptake. Northeast Australian 2010/2011 rainfall was 84% above average, unusual even for a strong La Niña, and soil moisture conditions were unprecedented since 1950. Here we demonstrate that the warmer background state increased the likelihood of the extreme rainfall response. Using atmospheric general circulation model experiments with 2010/2011 ocean conditions with and without long‐term warming, we identify the mechanisms that increase the likelihood of extreme rainfall: additional ocean warming enhanced onshore moisture transport onto Australia and ascent and precipitation over the northeast. Our results highlight the role of long‐term ocean warming for modifying rain‐producing atmospheric circulation conditions, increasing the likelihood of extreme precipitation for Australia during future La Niña events.
Complicated rupture process of theMw7.0 intraslab strike‐slip earthquake in the Tohoku region on 10 July 2011 revealed by near‐field pressure records
Authors: Kubota Tatsuya , Hino Ryota , Inazu Daisuke , Ito Yoshihiro , Iinuma Takeshi 
Published: November 2015

AbstractWe examined fault models of the Tohoku strike‐slip intraslab earthquake (Mw 7.0) on 10 July 2011 using near‐field tsunami data. After constraining the strike and location of the fault from tsunami source distribution, we investigated fault models assuming simple rupture of one fault, and simultaneous rupture of two conjugate faults. The estimated single fault reached >30 km down into the slab from the plate interface, suggesting bending stress enhancement after the 2011 Tohoku‐Oki earthquake, but the depth extent was inconsistent with the aftershock activity. The model involving conjugate faults extended ~20 km below the slab surface and was more consistent with the aftershocks. We concluded that it is more plausible that this earthquake involved two conjugate strike‐slip faults, and the enhancement of the downdip extensional stress after Tohoku‐Oki earthquake was not large enough to allow rupture to propagate deeply into the slab beneath the landward slope of the Japan Trench.
Preimpact porosity controls the gravity signature of lunar craters
Authors: Milbury C. , Johnson B. C. , Melosh H. J. , Collins G. S. , Blair D. M. , Soderblom J. M. , Nimmo F. , Bierson C. J. , Phillips R. J. , Zuber M. T. 
Published: November 2015

AbstractWe model the formation of lunar complex craters and investigate the effect of preimpact porosity on their gravity signatures. We find that while preimpact target porosities less than ~7% produce negative residual Bouguer anomalies (BAs), porosities greater than ~7% produce positive anomalies whose magnitude is greater for impacted surfaces with higher initial porosity. Negative anomalies result from pore space creation due to fracturing and dilatant bulking, and positive anomalies result from destruction of pore space due to shock wave compression. The central BA of craters larger than ~215 km in diameter, however, are invariably positive because of an underlying central mantle uplift. We conclude that the striking differences between the gravity signatures of craters on the Earth and Moon are the result of the higher average porosity and variable porosity of the lunar crust.
A simplified wave enhancement criterion for moving extreme events
Authors: Kudryavtsev Vladimir , Golubkin Pavel , Chapron Bertrand 
Published: October 2015

AbstractAn analytical model is derived to efficiently describe the wave energy distribution along the main transects of a moving extreme weather event. The model essentially builds on a generalization of the self‐similar wave growth model and the assumption of a strongly dominant single spectral mode in a given quadrant of the storm. The criterion to anticipate wave enhancement with the generation of trapped abnormal waves defined as
, with
,
, and
, radial distance, average sustained wind speed, and translation velocity, respectively. Constants
and
follow the fetch‐law definitions. If forced during a sufficient time scale interval, also defined from this generalized self‐similar wave growth model, waves can be trapped and large amplification of the wave energy will occur in the front‐right storm quadrant. Remarkably, the group velocity and corresponding wavelength of outrunning wave systems will become wind speed independent and solely related to the translating velocity. The resulting significant wave height also only weakly depends on wind speed, and more strongly on the translation velocity. Compared to altimeter satellite measurements, the proposed analytical solutions for the wave energy distribution demonstrate convincing agreement. As analytically developed, the wave enhancement criterion can provide a rapid evaluation to document the general characteristics of each storm, especially the expected wavefield asymmetry.
Multidecadal change in the dissolved inorganic carbon in a long‐term ocean state estimation
Authors: Doi Toshimasa , Osafune Satoshi , Sugiura Nozomi , Kouketsu Shinya , Murata Akihiko , Masuda Shuhei , Toyoda Takahiro 
Published: October 2015

AbstractBy using a four‐dimensional variational data assimilation system capable of estimating physical and biogeochemical variables for the global ocean, we investigated multidecadal changes in the dissolved inorganic carbon (DIC) in the ocean. The system was newly constructed with a pelagic ecosystem model and an oceanic general circulation model to integrate available ocean observations obtained with a wide range of observation tools. The distribution of estimated DIC was by and large consistent with previous reports. We validated the changes in DIC along the World Ocean Circulation Experiment (WOCE) Hydrographic Program sections. The correlation coefficients of the modeled versus observed decadal difference patterns of DIC ranged from 0.25 to 0.51 in the Pacific Ocean, from 0.36 to 0.62 in the Atlantic Ocean, and from 0.23 to 0.57 in the Indian Ocean, and were significant at the 95% confidence level. Thus, at basin scale, the reproducibility of long‐term climate change was similar. Estimation of vertical DIC fluxes in each basin showed that the fluxes changed on a multidecadal time scale in our system. These changes were possibly due to changes in the dynamical state of CO2 absorption and to changes in ocean circulation. Our integrated data set on the basis of a dynamically self‐consistent ocean state is a promising tool for examining long‐term changes in the ocean carbon cycle.
Phenotypic plasticity and constraint along the upper and lower limb diaphyses of Homo sapiens
Authors: Nadell Jason A. , Shaw Colin N. 
Published: November 2015

ABSTRACTObjectivesMorphological variation along the human limb reflects complex structural trade‐offs between bone strength and mass. Here we assess how varying levels of plasticity and constraint affect this structure and influence the response to habitual loading along the diaphysis.Materials and MethodsCross‐sectional geometric properties including total area, cortical area, and rigidity were compared from the upper (humerus: 50% of length, radius: 66%, 50%, 4%) and lower (tibia: 50%, 38%, 4%) limbs of male varsity‐level athletes and matched controls with distinct habitual loading histories.ResultsGeometric properties among cricketers and swimmers were significantly greater at the humeral midshaft, mid‐proximal radius, and radial midshaft compared to controls. By contrast, no significant differences were found among athletes or controls at the distal radius. The tibial midshafts of hockey players and runners also displayed greater area and rigidity compared to controls. Differences in geometry among the three groups became less pronounced distally, where structure was comparable among athletes and controls at 4% of tibial length. Additionally, coefficients of variation revealed that variation among athletes of the same sport was highest distally in both the upper and lower limb and lowest at midshaft, where structure most closely reflected the activity pattern of each loading group.DiscussionThese results support previous research suggesting that distal limb sections are more tightly constrained by safety factors compared to midshafts and proximal sections. Overall, it appears that plasticity and constraint vary not only between limb segments in correspondence to known activity patterns, but also along specific sections of the diaphysis. Am J Phys Anthropol 159:410–422, 2016. © 2015 Wiley Periodicals, Inc.
Development and characterization of chitosan bionanocomposites containing oxidized cellulose nanocrystals
Authors: Souza Vanderlei C. , Niehues Eduardo , Quadri Mara G. N. 
Published: October 2015

ABSTRACTIn this research, cellulose nanocrystals (CNs) were extracted from corn cobs by 2,2,6,6,‐tetramethylpiperidine‐1‐oxyl radical‐mediated oxidation combined with ultrasonic treatment for the first time. These CNs were then used as a mechanical reinforcement agent and barrier in chitosan‐based bionanocomposite films. Birefringence analyses under crossed polarizers indicated the presence of isolated nanocrystals in suspension, which was later confirmed by TEM analysis. The crystallinity index obtained from X‐ray diffraction was 92.4%. The incorporation of these nanoparticles into a filmogenic matrix of chitosan made it possible to obtain bionanocomposite films with improved properties. The water‐vapor permeability was reduced by 70%, whereas the tensile strength and Young's modulus increased by up to 136 and 224% respectively. The developed films were applied as interleaving of sliced cheese, and the efficiency was assessed by investigation of adhesion between the surfaces and by comparing its properties with two commercial interleaving products (polyethylene (PE), and Greasepel paper (GP)). Concluding, the developed films showed a substantial potential to be exploited as an interleaving film, owing to its excellent mechanical properties, permeability, hydrophobicity, and low surface adhesion compared to pure chitosan, PE, and GP films. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43033.
Experimental study of the rheological, mechanical, and dielectric properties of MgO/LDPE nanocomposites
Authors: Lin Xiang , Wu YunHui , Tang Lu Yang , Yang Min Hao , Ren Dong Yun , Zha Jun Wei , Dang Zhi Min 
Published: October 2015

ABSTRACTThe properties of the polymer nanocomposites (PNCs), consisting low density polyethylene (LDPE) and magnesium oxide nanoparticles (MgO‐NPs), were systematically discussed in this paper. The shear mixing time and MgO concentration were considered as the two factors affecting the dispersion state, which was found to be effective to change the crystallinity and the mechanical performance of MgO/LDPE PNCs. A reduction in the dynamic shear viscosity was observed when the concentration of MgO‐NPs at a relative low level, which was also dominant by the dispersion states of MgO‐NPs. Evident enhancement of the static yield stress was revealed only by introducing a minute amount of MgO‐NPs (0.25 wt %). Meanwhile, the elastic and loss modulus were also found to be dependent on the dispersion state of MgO‐NPs. A positive increase in dielectric permittivity was identified by uniaxial stretching the MgO/LDPE PNCs strips owing to the orientation enhancement of internal microstructure. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43038.
BODIPY/Nile‐Red‐Based Efficient FRET Pair: Selective Assay of Endoplasmic Reticulum Membrane Fluidity
Authors: Yang Zhigang , Wi Youngjin , Yoon Young‐Min , Verwilst Peter , Jang Joo Hee , Kim Tae Woo , Kang Chulhun , Kim Jong Seung 
Published: November 2015

AbstractWe synthesized a boron‐dipyrromethene (BODIPY)/Nile Red hybrid probe capable of selectively recognizing fluidity changes in the endoplasmic reticulum (ER) membrane due to its preferential localization to the ER and strong energy transfer from BODIPY to the Nile Red moiety, emitting only in nonaqueous environments. ER membrane fluidity in HepG2 cells was markedly reduced by a cell model of metabolic syndrome.
Tin Silsesquioxanes as Models for the “Open” Site in Tin‐Containing Zeolite Beta
Authors: Brand Stephen K. , Labinger Jay A. , Davis Mark E. 
Published: November 2015

AbstractThe use of biomass as a resource to produce value‐added products has garnered significant interest as a means of reducing reliance on fossil fuels. This task is complicated by the complex, highly functionalized nature of abundant biomass derivatives, such as glucose. Tin‐containing zeolite Beta (Sn‐Beta) can selectively isomerize glucose to fructose through a 1,2‐intramolecular hydride shift (1,2‐HS) or selectively produce mannose through a 1,2‐intramolecular carbon shift (1,2‐CS) by titration of the silanol groups with sodium (Na‐Sn‐Beta). To understand the structure–activity relationships between the conditions of the active sites in the zeolite, two molecular models (tin silsesquioxanes) of the tin sites in the zeolite were synthesized. Tin silsesquioxanes that contain an octahedral tin site with and without an adjacent silanol group selectively form fructose through a 1,2‐HS and mannose through a 1,2‐CS, respectively, and provide further evidence for the nature of the active sites in Sn‐Beta.
Runtime‐aware adaptive scheduling in stream processing
Authors: Liu Yuan , Shi Xuanhua , Jin Hai 
Published: October 2015

SummaryLong‐running stream applications usually share the same fundamental computational infrastructure. To improve the efficiency of data processing in stream processing systems, a data analysis operator could be partitioned into n parallel tasks. The partitioned tasks are usually deployed on m nodes coexisting with other application operators. Because the node performance can vary in unpredictable ways (i.e., (1) stream input rates may fluctuate and (2) computational resource availability varies as other applications are affected), the nodes have different processing steps, and the slow node determines the operator performance. Hence, the tasks should be redistributed at runtime for stream applications to meet their strict latency requirements. Our key idea is to redistribute the tasks to the best node dynamically adaptive to resource or load fluctuations. In this paper, we present a runtime‐aware adaptive schedule mechanism that aims at minimizing the operator processing latency and minimizing the latency difference between different nodes' tasks. We propose a new abstraction called performance cost ratio (PCR) that evaluates the node performance. The higher the node's PCR is, the less cost the node will pay for processing one tuple, and the more tasks should be deployed on it. In a scheduling, we first sort tasks descendingly by their loads and sort nodes by their PCR. Then we reassign the amount of computation according to the node's PCR to keep the node's PCR and its input rate the same or in similar proportion in all PCRs. The PCR‐based quantitative algorithm applies itself to make tasks loads quantized to the processing capacity of nodes, move the minimum amount of operator's tasks, and keep the tasks local at the same time. We have implemented a runtime‐aware adaptive scheduler as an extension to Storm and evaluated this strategy. We achieve the optimization goal using less computational resources. Copyright © 2015 John Wiley & Sons, Ltd.