bluuebunny/crossref_metadata_2025_split huggingface dataset:
KALREF—A Kalman filter and time series approach to the International Terrestrial Reference Frame realization
Authors: Wu Xiaoping , Abbondanza Claudio , Altamimi Zuheir , Chin T. Mike , Collilieux Xavier , Gross Richard S. , Heflin Michael B. , Jiang Yan , Parker Jay W. 
Published: April 2015

AbstractThe current International Terrestrial Reference Frame is based on a piecewise linear site motion model and realized by reference epoch coordinates and velocities for a global set of stations. Although linear motions due to tectonic plates and glacial isostatic adjustment dominate geodetic signals, at today's millimeter precisions, nonlinear motions due to earthquakes, volcanic activities, ice mass losses, sea level rise, hydrological changes, and other processes become significant. Monitoring these (sometimes rapid) changes desires consistent and precise realization of the terrestrial reference frame (TRF) quasi‐instantaneously. Here, we use a Kalman filter and smoother approach to combine time series from four space geodetic techniques to realize an experimental TRF through weekly time series of geocentric coordinates. In addition to secular, periodic, and stochastic components for station coordinates, the Kalman filter state variables also include daily Earth orientation parameters and transformation parameters from input data frames to the combined TRF. Local tie measurements among colocated stations are used at their known or nominal epochs of observation, with comotion constraints applied to almost all colocated stations. The filter/smoother approach unifies different geodetic time series in a single geocentric frame. Fragmented and multitechnique tracking records at colocation sites are bridged together to form longer and coherent motion time series. While the time series approach to TRF reflects the reality of a changing Earth more closely than the linear approximation model, the filter/smoother is computationally powerful and flexible to facilitate incorporation of other data types and more advanced characterization of stochastic behavior of geodetic time series.
On the trade‐off between seismic anisotropy and heterogeneity: Numerical simulations and application to Northeast Japan
Authors: Huang Zhouchuan , Zhao Dapeng , Liu Xin 
Published: April 2015

AbstractP wave tomography has been recently used to study 3‐D azimuthal and radial anisotropy of subduction zones and continental regions. However, the fundamental issue about the trade‐off between the isotropic and anisotropic structures is still unclear. In this study, we investigate this issue systematically with comprehensive synthetic tests. Our results indicate that good ray coverage in the azimuth (for azimuthal anisotropy) and incidence (for radial anisotropy) is required for determining reliable anisotropic models. The isotropic and anisotropic structures are strongly coupled, and smearing effects are significant when the rays used in the inversion are limited in a small range of azimuth or incidence. We therefore plot ray azimuth and ray incidence ellipses at every grid nodes and propose to use the normalized length of the short axis (i.e., the ratio of the short‐axis and long‐axis lengths) for estimating the ray coverage quantitatively. Applying our novel approach to a large number of high‐quality arrival time data of local shallow‐ and intermediate‐depth earthquakes, we obtained new tomographic images of 3‐D P wave azimuthal and radial anisotropy in Northeast Japan. Both the azimuthal and radial anisotropy results are determined reliably for the shallow parts of the study region, whereas the smearing effects are significant in the deeper part of the mantle wedge and the subducting slab. Our results show dominant trench‐normal and vertical‐fast anisotropy in the mantle wedge while trench‐parallel and horizontal‐fast anisotropy in the subducting slab, which indicates different dynamics in different domains of the subduction zone.
Estimating the Atlantic overturning at 26°N using satellite altimetry and cable measurements
Authors: Frajka‐Williams E. 
Published: April 2015

AbstractClimate simulations predict a slowing of the Atlantic meridional overturning circulation (MOC), a key oceanic component of the climate system, while continuous observations of the MOC from boundary arrays demonstrate substantial variability on weekly to interannual time scales. These arrays are necessarily limited to individual latitudes. A potential proxy for the MOC covering longer time scales and larger spatial scales is desirable. Here we use sea surface height data from satellites to estimate the interannual variability of transbasin ocean transports at 26°N. Combining this estimate with surface Ekman transport and cable measurements of the Florida Current, we construct a time series of the MOC from 1993 to 2014. This satellite‐based estimate recovers over 90% of the interannual variability of the MOC measured by the RAPID 26°N array. This analysis complements in situ observational efforts to measure the MOC at multiple latitudes and opens the door to a broader spatial understanding of the Atlantic circulation variability.
Impacts of extreme 2013–2014 winter conditions on Lake Michigan's fall heat content, surface temperature, and evaporation
Authors: Gronewold A. D. , Anderson E. J. , Lofgren B. , Blanken P. D. , Wang J. , Smith J. , Hunter T. , Lang G. , Stow C. A. , Beletsky D. , Bratton J. 
Published: April 2015

AbstractSince the late 1990s, the Laurentian Great Lakes have experienced persistent low water levels and above average over‐lake evaporation rates. During the winter of 2013–2014, the lakes endured the most persistent, lowest temperatures and highest ice cover in recent history, fostering speculation that over‐lake evaporation rates might decrease and that water levels might rise. To address this speculation, we examined interseasonal relationships in Lake Michigan's thermal regime. We find pronounced relationships between winter conditions and subsequent fall heat content, modest relationships with fall surface temperature, but essentially no correlation with fall evaporation rates. Our findings suggest that the extreme winter conditions of 2013–2014 may have induced a shift in Lake Michigan's thermal regime and that this shift coincides with a recent (and ongoing) rise in Great Lakes water levels. If the shift persists, it could (assuming precipitation rates remain relatively constant) represent a return to thermal and hydrologic conditions not observed on Lake Michigan in over 15 years.
Field dipolarization in Saturn's magnetotail with planetward ion flows and energetic particle flow bursts: Evidence of quasi‐steady reconnection
Authors: Jackman C. M. , Thomsen M. F. , Mitchell D. G. , Sergis N. , Arridge C. S. , Felici M. , Badman S. V. , Paranicas C. , Jia X. , Hospodarksy G. B. , Andriopoulou M. , Khurana K. K. , Smith A. W. , Dougherty M. K. 
Published: April 2015

AbstractWe present a case study of an event from 20 August (day 232) of 2006, when the Cassini spacecraft was sampling the region near 32 RS and 22 h LT in Saturn's magnetotail. Cassini observed a strong northward‐to‐southward turning of the magnetic field, which is interpreted as the signature of dipolarization of the field as seen by the spacecraft planetward of the reconnection X line. This event was accompanied by very rapid (up to ~1500 km s−1) thermal plasma flow toward the planet. At energies above 28 keV, energetic hydrogen and oxygen ion flow bursts were observed to stream planetward from a reconnection site downtail of the spacecraft. Meanwhile, a strong field‐aligned beam of energetic hydrogen was also observed to stream tailward, likely from an ionospheric source. Saturn kilometric radiation emissions were stimulated shortly after the observation of the dipolarization. We discuss the field, plasma, energetic particle, and radio observations in the context of the impact this reconnection event had on global magnetospheric dynamics.
Age Differences in Learning from Instructional Animations
Authors: Boucheix Jean‐Michel , Lowe Richard K. , Bugaiska Aurélia 
Published: April 2015

SummaryThe present study tests the effects of the decline of executive functions and spatial abilities with aging on the comprehension of a complex instructional animation. An animation of a piano mechanism was presented individually to 33 young adults and 31 elderly participants. Two presentation speeds of the animation (normal and slow) were compared in a 2 × 2 experimental design. Eye movements were recorded during the learning time. Then, four executive function tests (inhibition, shifting, updating, and processing speed) and a spatial ability test (differential aptitude test) were undertaken by each participant. Results showed that the comprehension of animations was significantly affected by aging. Significant differences between young and old groups were found for executive functions and spatial abilities. Regressions on comprehension scores showed a strong significant effect of spatial ability. Like in previous research, presentation speed had no effect. Eye movement data showed this result was due to application of a compensation strategy. Copyright © 2015 John Wiley & Sons, Ltd.
Synthesis of functionalizable derivatives of 3,4‐ethylenedioxythiophene and their solid‐state polymerizations
Authors: Gulprasertrat Narut , Chapromma Jirasak , Aree Thammarat , Sritana‐anant Yongsak 
Published: April 2015

ABSTRACTFour polythiophenes based on poly(3,4‐ethylenedioxythiophene) (PEDOT) framework have been successfully prepared by the facile thermal activated solid‐state polymerization (SSP) process from their corresponding dibromothiophene derivatives, which were efficiently obtained using our improved methodology. Rates of polymerizations of these precursors were varied and most of the processes were incomplete under the reaction condition chosen for the synthesis. Raising the reaction temperature of the SSP further advanced the polymerization progress and improved the conductive properties of the polymer. The polymer of 3,4‐ethylenedioxythiophene‐methanol (EDTM) and its two related derivatives with functionalizable groups were prepared for the first time by the SSP method. The process and these new SSP‐derived polymers could help solving the fabrication difficulty and expand the scope of their applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42233.
Atom‐Precise Polyoxometalate–Ag2S Core–Shell Nanoparticles
Authors: Li Xiao‐Yu , Tan Yuan‐Zhi , Yu Kai , Wang Xing‐Po , Zhao Ya‐Qin , Sun Di , Zheng Lan‐Sun 
Published: April 2015

AbstractAtomically precise polyoxometalate–Ag2S core–shell nanoparticles were generated in a top‐down approach under solvothermal conditions and structurally confirmed by X‐ray single‐crystal diffraction as an interesting core–shell structure comprising an in situ generated Mo6O228− polyoxometalate core and a mango‐like Ag58S38 shell. This result demonstrates the possibility to integrate polyoxometalate and Ag2S nanoparticles into a core–shell heteronanostructure with precisely controlled atomical compositions of both core and shell.
Sex Differences in Psychological Factors Associated with Social Discounting
Authors: Olson Elizabeth A. , Rosso Isabelle M. , Demers Lauren A. , Divatia Shreya , Killgore William D. S. 
Published: April 2015

AbstractThe social discounting paradigm is a powerful means of quantifying altruism in humans, who are typically willing to forgo some amount of personal earnings in exchange for increased earnings for another person. The amount of money that people are willing to forgo decreases with increasing social distance. In this study, we examined variables related to sex, intolerance of uncertainty, and empathy, all of which are theorized to affect the social discounting rate. Participants (27 men and 28 women) completed measures of intolerance of uncertainty, empathy, and social discounting. We found sex differences in psychological predictors of social discounting: in women, empathy (but not intolerance of uncertainty) predicts the social discounting rate, while in men, social discounting is associated with intolerance of uncertainty (but not empathy). Possible neurobiological, social, and cognitive explanations for this sex difference are discussed. Copyright © 2015 John Wiley & Sons, Ltd.
Hexasomy 13q31.3q34 due to two marker chromosomes with inverted duplication in a fetus with increased nuchal translucency
Authors: Stembalska Agnieszka , Jagielska Gizela , Laczmanska Izabela , Szmida Elzbieta , Jarczynska Alicja , Gil Justyna 
Published: April 2015

BackgroundSmall supernumerary marker chromosomes are structurally rearranged chromosomes that can be formed from different chromosomal fragments and cannot be identified using chromosomal banding analysis. Their examination has to be complemented by additional analyses like fluorescent in situ hybridization or array comparative genomic hybridization.MethodsWe report on partial hexasomy of chromosome 13q in a fetus of a pregnant woman referred to genetic counseling because of increased fetal nuchal translucency and increased risk of trisomy 21 and trisomy 18 in first‐trimester combined prenatal screening. Using chromosome banding analysis, in situ hybridization and array comparative hybridization we revealed the presence of two marker chromosomes with inverted duplication resulting in hexasomy of a 22.6 Mbp fragment in chromosomal region 13q31.3‐13q34 with the lack of chromosome 13 centromere.ResultsThe fetus presented dysmorphic facial features, head and body disproportion, wide neck, ambiguous genitalia, incorrect position of the anus, and symmetrical shortening of the long bones were present in our described case. Some of these features were in accordance with other published cases. Other most often described features in tetrasomy were: microphtalmia or other major eye defects, ear abnormalities and deafness, hemangiomata, hypotelorism, severe learning disability and seizures. Despite a low risk of recurrence for small supernumerary marker chromosomes the possibility of germ line mosaicism exists, thus genetic counseling was offered to the examined family.ConclusionA full characterization of small supernumerary marker chromosomes in fetal karyotype is necessary for pregnancy prognosis and genetic counseling. Birth Defects Research (Part A) 103:255–259, 2015. © 2015 Wiley Periodicals, Inc.
Simple synthesis of luminescent CdSe quantum dots from ascorbic acid and selenium dioxide
Authors: Wang Yilin , Yu Meihua , Yang Kun , Lu Jianping , Chen Linqing 
Published: April 2015

AbstractA simple, low‐cost and convenient method was developed for the synthesis of highly luminescent CdSe quantum dots (QDs) in an aqueous medium. Compared with previous methods, this synthesis was carried out in one pot using ascorbic acid (C6H8O6) to replace NaBH4 or N2H4 · H2O as a reductant, and selenium dioxide to replace selenium or its other hazardous, expensive and unstable compounds as a precursor. The mechanism of CdSe QDs formation was elucidated. The influence of various experimental variables, including refluxing time, Cd/MSA and Cd/Se molar ratios, on the luminescent properties of the QDs were systematically investigated. X‐Ray powder diffraction and transmission electron microscopy characterization indicated that the QDs had a pure cubic zinc‐blended structure with a spherical shape. Copyright © 2015 John Wiley & Sons, Ltd.
Preparation and in vitro antioxidant activities of 6‐amino‐6‐deoxychitosan and its sulfonated derivatives
Authors: Yang Jianhong , Xie Qinyue , Zhu Jianfeng , Zou Chang , Chen Lingyun , Du Yumin , Li Dinglong 
Published: April 2015

ABSTRACTThe 6‐amino‐6‐deoxychitosan (NC) and their 2, 6‐di‐N‐sulfonated derivatives were prepared via N‐phthaloylation, tosylation, azidation, hydrazinolysis, reduction of azide groups and N‐sulfonation, and their structures were systematically characterized by FT‐IR, 2D HSQC NMR, XRD, gel permeation chromatography (GPC), and elemental analysis. The 6‐amino‐6‐deoxychitosan showed effect in three selected antioxidant essays, including reducing power, superoxide anion radical scavenging ability, and hydroxyl radical scavenging effect. But the factors affecting each activity were different. The reducing power and the superoxide anion radical scavenging ability of NC were strong and closely related to the amino groups in the molecular chains. Both introducing N‐sulfonated groups into NC and the concentration reduction of NC and its sulfonated derivatives decreased these activities. For the superoxide anion radical, the molecular charge property was also a significant influence factor. For the hydroxyl radical, NC only showed weak scavenging activity in a special inverse concentration‐dependent manner. However, the incorporation of N‐sulfonated groups significantly improved the scavenging activity, and the more N‐sulfonated groups, the higher the concentrations, the stronger the activity was. The results could be due to the different conformations of NC and its sulfonated derivatives in aqueous solution. © 2015 Wiley Periodicals, Inc. Biopolymers 103: 539–549, 2015.
Temporal characterization of protein production levels from baculovirus vectors coding for GFP and RFP genes under non‐conventional promoter control
Authors: George Steve , Jauhar Altamash M. , Mackenzie Jennifer , Kieβlich Sascha , Aucoin Marc G. 
Published: April 2015

ABSTRACTThe ease of use and versatility of the Baculovirus Expression Vector System (BEVS) has made it one of the most widely used systems for recombinant protein production However, co‐expression systems currently in use mainly make use of the very strong very late p10 and polyhedron (polh) promoters to drive expression of foreign genes, which does not provide much scope for tailoring expression ratios within the cell. This work demonstrates the use of different Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) promoters to control the timing and expression of two easily traceable fluorescent proteins, the enhanced green fluorescent protein (eGFP), and a red fluorescent protein (DsRed2) in a BEVS co‐expression system. Our results show that gene expression levels can easily be controlled using this strategy, and also that modulating the expression level of one protein can influence the level of expression of the other protein within the system, thus confirming the concept of genes “competing” for limited cellular resources. Plots of “expression ratios” of the two model genes over time were obtained, and may be used in future work to tightly control timing and levels of foreign gene expression in an insect cell co‐expression system. Biotechnol. Bioeng. 2015;112: 1822–1831. © 2015 Wiley Periodicals, Inc.
Optimization and automation of an end‐to‐end high throughput microscale transient protein production process
Authors: Bos Aaron B. , Luan Peng , Duque Joseph N. , Reilly Dorothea , Harms Peter D. , Wong Athena W. 
Published: April 2015

ABSTRACTHigh throughput protein production from transient transfection of mammalian cells is used in multiple facets of research and development studies. Commonly used formats for these high number expressions are 12‐, 24‐ and 96‐well plates at various volumes. However there are no published examples of a 96‐deep well plate microscale (1,000 μL) suspension process for mammalian transient expression. For this reason, we aimed to determine the optimal operating conditions for a high producing, microscale HEK293 transient system. We evaluated the hydrodynamic flow and measured the oxygen transfer rate (OTR) and transient protein expression for 96‐deep well plates of different well geometries filled at 600–1,000 μL working volumes and agitated at various speeds and orbital diameters. Ultimately, a round well‐round bottom (RR) 96‐deep well plate with a working volume of 1,000 µL agitated at 1,000 RPM and a 3 mm orbital diameter yielded the highest and most consistent total transient protein production. As plate cultures are subject to evaporation, water loss from different plate seals was measured to identify an optimal plate sealing method. Finally, to enable higher capacity protein production, both expression and purification processes were automated. Functionality of this end‐to‐end automation workflow was demonstrated with the generation of high levels of human IgG1 antibodies (≥360 µg/mL) with reproducible productivity, product quality and ≥78% purification recovery. Biotechnol. Bioeng. 2015;112: 1832–1842. © 2015 Wiley Periodicals, Inc.
Effects of phosphate limitation on soluble microbial products and microbial community structure in semi‐continuous Synechocystis‐based photobioreactors
Authors: Zevin Alexander S. , Nam Taekgul , Rittmann Bruce , Krajmalnik‐Brown Rosa 
Published: April 2015

ABSTRACTAll bacteria release organic compounds called soluble microbial products (SMP) as a part of their normal metabolism. In photobioreactor (PBR) settings, SMP produced by cyanobacteria represent a major pool of carbon and electrons available to heterotrophic bacteria. Thus, SMP in PBRs are a major driver for the growth of heterotrophic bacteria, and understanding the distribution of SMP in PBRs is an important step toward proper management of PBR microbial communities. Here, we analyzed the SMP and microbial communities in two Synechocystis sp. PCC6803‐based PBRs. The first PBR (PBRP0) became phosphate limited after several days of operation, while the second PBR (PBRP+) did not have phosphate limitation. Heterotrophic bacteria were detected in both PBRs, but PBRP0 had a much higher proportion of heterotrophic bacteria than PBRP+. Furthermore, PBRP+ had greater biomass production and lower SMP production per unit biomass than PBRP0. Carbohydrates that were most likely derived from hydrolysis of extracellular polymeric substances (EPS) dominated the SMP in PBRP0, while products resulting from cell lysis or decay dominated the SMP in PBRP+. Together, our data support that maintaining phosphate availability in Synechocystis‐based PBRs is important for managing SMP and, thus, the heterotrophic community. Biotechnol. Bioeng. 2015;112: 1761–1769. © 2015 Wiley Periodicals, Inc.
Using Adobe Flash Animations of electron transport chain to teach and learn biochemistry
Authors: Teplá Milada , Klímová Helena 
Published: April 2015

AbstractTeaching the subject of the electron transport chain is one of the most challenging aspects of the chemistry curriculum at the high school level. This article presents an educational program called “Electron Transport Chain” which consists of 14 visual animations including a biochemistry quiz. The program was created in the Adobe Flash CS3 Professional animation program and is designed for high school chemistry students. Our goal is to develop educational materials that facilitate the comprehension of this complex subject through dynamic animations which show the course of the electron transport chain and simultaneously explain its nature. We record the process of the electron transport chain, including connections with oxidative phosphorylation, in such a way as to minimize the occurrence of discrepancies in interpretation. The educational program was evaluated in high schools through the administration of a questionnaire, which contained 12 opened‐ended items and which required participants to evaluate the graphics of the animations, chemical content, student preferences, and its suitability for high school biochemistry teaching. © 2015 by the International Union of Biochemistry and Molecular Biology, 43(4):294–299, 2015.