bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast 3‐D large‐scale gravity and magnetic modeling using unstructured grids and an adaptive multilevel fast multipole method
Authors: Ren Zhengyong , Tang Jingtian , Kalscheuer Thomas , Maurer Hansruedi 
Published: December 2016

AbstractA novel fast and accurate algorithm is developed for large‐scale 3‐D gravity and magnetic modeling problems. An unstructured grid discretization is used to approximate sources with arbitrary mass and magnetization distributions. A novel adaptive multilevel fast multipole (AMFM) method is developed to reduce the modeling time. An observation octree is constructed on a set of arbitrarily distributed observation sites, while a source octree is constructed on a source tetrahedral grid. A novel characteristic is the independence between the observation octree and the source octree, which simplifies the implementation of different survey configurations such as airborne and ground surveys. Two synthetic models, a cubic model and a half‐space model with mountain‐valley topography, are tested. As compared to analytical solutions of gravity and magnetic signals, excellent agreements of the solutions verify the accuracy of our AMFM algorithm. Finally, our AMFM method is used to calculate the terrain effect on an airborne gravity data set for a realistic topography model represented by a triangular surface retrieved from a digital elevation model. Using 16 threads, more than 5800 billion interactions between 1,002,001 observation points and 5,839,830 tetrahedral elements are computed in 453.6 s. A traditional first‐order Gaussian quadrature approach requires 3.77 days. Hence, our new AMFM algorithm not only can quickly compute the gravity and magnetic signals for complicated problems but also can substantially accelerate the solution of 3‐D inversion problems.
Pressure dependence of electrical conductivity in forsterite
Authors: Yoshino Takashi , Zhang Baohua , Rhymer Brandon , Zhao Chengcheng , Fei Hongzhan 
Published: December 2016

AbstractElectrical conductivity of dry forsterite has been measured in muli‐anvil apparatus to investigate the pressure dependence of ionic conduction in forsterite. The starting materials for the conductivity experiments were a synthetic forsterite single crystal and a sintered forsterite aggregate synthesized from oxide mixture. Electrical conductivities were measured at 3.5, 6.7, 9.6, 12.1, and 14.9 GPa between 1300 and 2100 K. In the measured temperature range, the conductivity of single crystal forsterite decreases in the order of [001], [010], and [100]. In all cases, the conductivity decreases with increasing pressure and then becomes nearly constant for [100] and [001] and slightly increases above 7 GPa for [010] orientations and a polycrystalline forsterite sample. Pressure dependence of forsterite conductivity was considered as a change of the dominant conduction mechanism composed of migration of both magnesium and oxygen vacancies in forsterite. The activation energy (ΔE) and activation volume (ΔV) for ionic conduction due to migration of Mg vacancy were 1.8–2.7 eV and 5–19 cm3/mol, respectively, and for that due to O vacancy were 2.2–3.1 eV and −1.1 to 0.3 cm3/mol, respectively. The olivine conductivity model combined with small polaron conduction suggests that the most part of the upper mantle is controlled by ionic conduction rather than small polaron conduction. The previously observed negative pressure dependence of the conductivity of olivine with low iron content (Fo90) can be explained by ionic conduction due to migration of Mg vacancies, which has a large positive activation volume.
Hydrographic and ecologic implications of foraminiferal stable isotopic response across the U.S. mid‐Atlantic continental shelf during the Paleocene‐Eocene Thermal Maximum
Authors: Makarova Maria , Wright James D. , Miller Kenneth G. , Babila Tali L. , Rosenthal Yair , Park Jill I. 
Published: December 2016

AbstractWe present new δ13C and δ18O records of surface (MorozovellaandAcarinina) and thermocline dwelling (Subbotina) planktonic foraminifera and benthic foraminifera (Gavelinella,Cibicidoides, andAnomalinoides) during the Paleocene‐Eocene Thermal Maximum (PETM) from Millville, New Jersey, and compare them with three other sites located along a paleoshelf transect from the U.S. mid‐Atlantic coastal plain. Our analyses show different isotopic responses during the PETM in surface versus thermocline and benthic species. Whereas all taxa record a 3.6–4.0‰ δ13C decrease associated with the carbon isotope excursion, thermocline dwellers and benthic foraminifera show larger δ18O decreases compared to surface dwellers. We consider two scenarios that can explain the observed isotopic records: (1) a change in the water column structure and (2) a change in habitat or calcification season of the surface dwellers due to environmental stress (e.g., warming, ocean acidification, surface freshening, and/or eutrophication). In the first scenario, persistent warming during the PETM would have propagated heat into deeper layers and created a more homogenous water column with a thicker warm mixed layer and deeper, more gradual thermocline. We attribute the hydrographic change to decreased meridional thermal gradients, consistent with models that predict polar amplification. The second scenario assumes that environmental change was greater in the mixed layer forcing surface dwellers to descend into thermocline waters as a refuge or restrict their calcification to the colder seasons. Although both scenarios are plausible, similar δ13C responses recorded in surface, thermocline, and benthic foraminifera challenge mixed layer taxa migration.
Electrostatic thermal noise in a weakly ionized collisional plasma
Authors: Martinović M. M. , Zaslavsky A. , Maksimović M. , Šegan S. 
Published: December 2016

AbstractQuasi‐thermal noise (QTN) spectroscopy is a plasma diagnostic technique which enables precise measurements of local electron velocity distribution function moments. This technique is based on measurements and analysis of voltage fluctuations at the antenna terminals, induced by thermal motion of charged particles. In this work, we accommodate, for the first time, this technique to weakly ionized collisional plasmas. It turns out that the QTN spectrum is modified both at low frequencies, increasing the level of power spectrum, and around the plasma frequency, where collisions damp the plasma oscillations and therefore broaden and reduce the amplitude of so called “plasma peak,” while the spectrum at high frequencies is nearly unmodified compared to the collisionless case. Based on these results, we show that QTN spectroscopy enables independent measurements of the collision frequency, electron density, and temperature, provided the ratio of collision frequency to plasma frequency is ν/ωp∼0.1. The method presented here can be used for precise estimation of plasma parameters in laboratory devices and unmagnetized ionospheres, while application in the ionosphere of Earth is possible but limited to small, low‐frequency range due to magnetic field influence.
Facile Construction of Imidazo‐benzothia‐/oxazepines by a Quick and Efficient van Leusen Protocol
Authors: Saha Debasmita , Kaur Tanpreet , Sharma Anuj 
Published: December 2016

AbstractA facile, elegant, and operationally simple van Leusen protocol for the synthesis of bicyclic dihydrodibenzo[b,f]imidazo[1,2‐d][1,4]thiazepines and dihydrodibenzo[b,f]imidazo[1,2‐d][1,4]oxazepines is developed. The reaction proceeds without any catalyst and in high yields to provide bicyclic imidazo‐dibenzothia‐/oxazepines at room temperature by using dibenzothiazepines or dibenzoxazepines as imine counterparts.
Controllable Synthesis of Hexagonal WO3 Nanoplates for Efficient Visible‐Light‐Driven Photocatalytic Oxygen Production
Authors: Wang Yu Lei , Wang Xue Lu , Li Yu Hang , Fang Li Jun , Zhao Jun Jie , Du Xu Lei , Chen Ai Ping , Yang Hua Gui 
Published: December 2016

AbstractFacilitating charge‐carrier separation and transfer is fundamentally important to improve the photocatalytic performance of semiconductor materials. Herein, two‐dimensional hexagonal WO3 nanoplates were synthesized by a two‐step route: rapid evaporation and solid‐phase sintering. The as‐prepared WO3 exhibits an enhanced activity of photocatalytic water oxidation compared to bulk monoclinic WO3. The electron dynamics analysis reveals that a more efficient charge‐carrier separation in the former can be obtained, the origin of which can be attributed to an increased number of surface defects in hexagonal WO3 nanoplates. This work not only presents a novel and simple method to produce two‐dimensional hexagonal WO3 nanoplates, but also demonstrates that surface defects and two‐dimensional geometric structures can promote the charge separation, which may be extended to the design of other efficient photocatalysts.
HIPE Polymerization Materials Functionalized with Iodic‐BODIPY on the Surface as Porous Heterogeneous Visible‐Light Photocatalysts
Authors: Li Wenliang , Li Leijiao , Cui Guihua , Bai Yu , Xiao Xiao , Li Yuxin , Yan Lesan 
Published: December 2016

AbstractA high internal phase emulsion polymerization (PolyHIPE) material, with iodine‐functionalized boron‐dipyrromethene (iodic‐BODIPY) immobilized on its surface, composes a porous heterogeneous organic photocatalyst (iodic‐BODIPY‐PolyHIPE). It shows high catalytic efficiency on the selective oxidation reaction of aromatic sulfides under visible light. The substrates were almost fully converted to their corresponding sulfoxides and no sulfones were observed. Most importantly, iodic‐BODIPY‐PolyHIPE shows >1.6‐fold reaction rate compared to the previous non‐inorganic heterogeneous photocatalysts.
Solid‐phase microextraction of methadone in urine samples by electrochemically co‐deposited sol–gel/Cu nanocomposite fiber
Authors: Mohammadiazar Sirwan , Hasanli Fateme , Maham Mehdi , Payami Samarin Somayeh 
Published: December 2016

AbstractElectrochemically co‐deposited sol–gel/Cu nanocomposites have been introduced as a novel, simple and single‐step technique for preparation of solid‐phase microextraction (SPME) coating to extract methadone (MDN) (a synthetic opioid) in urine samples. The porous surface structure of the sol–gel/Cu nanocomposite coating was revealed by scanning electron microscopy. Direct immersion SPME followed by HPLC‐UV determination was employed. The factors influencing the SPME procedure, such as the salt content, desorption solvent type, pH and equilibration time, were optimized. The best conditions were obtained with no salt content, acetonitrile as desorption solvent type, pH 9 and 10 min equilibration time. The calibration graphs for urine samples showed good linearity. The detection limit was about 0.2 ng mL−1. Also, the novel method for preparation of nanocomposite fiber was compared with previously reported techniques for MDN determination. The results show that the novel nanocomposite fiber has relatively high extraction efficiency.
Alpha‐PVP as an active component of herbal highs in Poland between 2013 and 2015
Authors: Byrska Bogumiła , Stanaszek Roman , Zuba Dariusz 
Published: December 2016

Alpha‐PVP (alpha‐pyrrolidinovalerophenone, α‐PVP) is a synthetic derivative of cathinone. It has been one of the most frequently detected new psychoactive substances (NPS) available on the drug market in recent years in Poland. The usual routes of administration of the drug include oral, insufflation, and injection. Unexpectedly, we dealt with a great number of herbal samples that turned out to contain α‐PVP. A total number of 352 herbal samples from 19 cases in which we detected synthetic cathinones, were investigated in the Institute of Forensic Research (IFR) from 2013 to 2015. The seized products that were received by our laboratory were first screened by gas chromatography coupled to mass spectrometry (GC–MS). Quantification of α‐PVP and other cathinones was performed by ultra‐performance liquid chromatography with photodiode array detection (UPLC‐PDA). Of the samples, 84% contained only α‐PVP. Other groups of products were those containing only α‐PVT, α‐PVP and α‐PVT, α‐PVP and synthetic cannabinoid A‐834, 735, and α‐PVP and cannabis. In one herbal sample, α‐PVP was detected along with caffeine and tadalafil. The herbal products present on the market containing only α‐PVP usually had a mass of 0.3 to 0.6 g, and concentration range in this group of samples was 3.0–44.0% (content: 13.0–222.0 mg per package). The amount of α‐PVP in samples below 0.30 g was in a range 9–18 mg whiles in samples above 0.60 g it was in the range 30–716 mg. There were also products containing a mixture of α‐PVP and α‐PVT. In those samples, α‐PVP concentrations were: 3.0–6.0% (amount: 15.0–34.0 mg). Copyright © 2016 John Wiley & Sons, Ltd.
Introduction to the sampling designs of the National Ecological Observatory Network Terrestrial Observation System
Authors: Thorpe Andrea S. , Barnett David T. , Elmendorf Sarah C. , Hinckley Eve‐Lyn S. , Hoekman David , Jones Katherine D. , LeVan Katherine E. , Meier Courtney L. , Stanish Lee F. , Thibault Katherine M. 
Published: December 2016

AbstractGlobal change drivers influence ecological processes at multiple scales and manifest across most of Earth as changes in biodiversity, biogeochemical cycles, infectious disease incidence, and ecohydrology. Small‐scale investigations provide compelling evidence of specific effects of global change on local systems, but are of limited use in modeling complex ecological processes at continental‐to‐global scales. Long‐term observations distributed across a diversity of habitat types are needed to improve the ability to forecast ecological change at large spatial and temporal scales. This special issue introduces the Terrestrial Observation System (TOS) of the National Ecological Observatory Network (NEON), a long‐term, continental‐scale ecological research platform designed to deliver these large‐scale datasets. The TOS measures biodiversity of key biota (soil microbes, insects, plants, small mammals), ecosystem productivity and biogeochemistry, infectious disease dynamics, phenology, and population dynamics. The articles in this special issue describe the scientific rationale for the sampling designs of the TOS, including an overview of protocols, locations, and frequencies of measurements. The science designs are a culmination of design requirements scoped by NEON and the National Science Foundation, best available practices put forth by the scientific community, input from technical working groups, and consideration of logistical and financial constraints by NEON staff. Within each site, measurements have been collocated to the extent possible to optimize linkages among different sampling elements. Integrated analyses of terrestrial observations with sensor‐based, imagery, and remote‐sensing data collected by other NEON subsystems can facilitate scaling of measured parameters to larger spatial and temporal scales. NEON is designed to collect data for 30 years, and make these data freely available on a public data portal (data.neonscience.org). Samples and specimens will be archived and available to the scientific community upon request. The open access approach to the Observatory will provide users with the resources necessary to map, understand, and predict the effects of global change drivers on ecological processes at a continental scale.
Impacts of invasive plants on carbon pools depend on both species’ traits and local climate
Authors: Martin Philip A. , Newton Adrian C. , Bullock James M. 
Published: December 2016

AbstractInvasive plants can alter ecosystem properties, leading to changes in the ecosystem services on which humans depend. However, generalizing about these effects is difficult because invasive plants represent a wide range of life forms, and invaded ecosystems differ in their plant communities and abiotic conditions. We hypothesize that differences in traits between the invader and native species can be used to predict impacts and so aid generalization. We further hypothesize that environmental conditions at invaded sites modify the effect of trait differences and so combine with traits to predict invasion impacts. To test these hypotheses, we used systematic review to compile data on changes in aboveground and soil carbon pools following non‐native plant invasion from studies across the World. Maximum potential height (Hmax) of each species was drawn from trait databases and other sources. We used meta‐regression to assess which of invasive species’Hmax, differences in this height trait between native and invasive plants, and climatic water deficit, a measure of water stress, were good predictors of changes in carbon pools following invasion. We found that aboveground biomass in invaded ecosystems relative to uninvaded ones increased as the value ofHmaxof invasive relative to native species increased, but that this effect was reduced in more water stressed ecosystems. Changes in soil carbon pools were also positively correlated with the relativeHmaxof invasive species, but were not altered by water stress. This study is one of the first to show quantitatively that the impact of invasive species on an ecosystem may depend on differences in invasive and native species’ traits, rather than solely the traits of invasive species. Our study is also the first to show that the influence of trait differences can be altered by climate. Further developing our understanding of the impacts of invasive species using this framework could help researchers to identify not only potentially dangerous invasive species, but also the ecosystems where impacts are likely to be greatest.
Touchscreen auf der Haut
Authors: Steimle Jürgen , Bolduan Gordon 
Published: December 2016

AbstractIntegriert, leistungsstark und oft kaum sichtbar: Schon bald wird in nahezu jedem Objekt ein Computer stecken. Informatiker arbeiten daran, die Schnittstellen für die Mensch‐Maschine‐Interaktion zu verbessern. Der Trend geht zu buchstäblich flexiblen Lösungen.
Reduced perfusion in Broca's area in developmental stuttering
Authors: Desai Jay , Huo Yuankai , Wang Zhishun , Bansal Ravi , Williams Steven C. R. , Lythgoe David , Zelaya Fernando O. , Peterson Bradley S. 
Published: December 2016

AbstractObjectiveTo study resting cerebral blood flow in children and adults with developmental stuttering.MethodsWe acquired pulsed arterial spin labeling magnetic resonance imaging data in 26 participants with stuttering and 36 healthy, fluent controls. While covarying for age, sex, and IQ, we compared perfusion values voxel‐wise across diagnostic groups and assessed correlations of perfusion with stuttering severity within the stuttering group and with measures of motor speed in both groups.ResultsWe detected lower regional Cerebral Blood Flow (rCBF) at rest in the stuttering group compared with healthy controls in Broca's area bilaterally and the superior frontal gyrus. rCBF values in Broca's area bilaterally correlated inversely with the severity of stuttering and extended posteriorly into other portions of the language loop. We also found increased rCBF in cerebellar nuclei and parietal cortex in the stuttering group compared with healthy controls. Findings were unchanged in child‐only analyses and when excluding participants with comorbid illnesses or those taking medication.ConclusionsrCBF is reduced in Broca's region in persons who stutter. More severe stuttering is associated with even greater reductions in rCBF to Broca's region, additive to the underlying putative trait reduction in rCBF relative to control values. Moreover, a greater abnormality in rCBF in the posterior language loop is associated with more severe symptoms, suggesting that a common pathophysiology throughout the language loop likely contributes to stuttering severity. Hum Brain Mapp 38:1865–1874, 2017. © 2017 Wiley Periodicals, Inc.
Influence of Poly(ε‐caprolactone) Molecular Weight and Coumarin Amount on Photo‐Responsive Polyurethane Properties
Authors: Salgado Cástor , Arrieta Marina P. , Peponi Laura , Fernández‐García Marta , López Daniel 
Published: December 2016

Photo‐reversible polyurethane (PU) coatings based on coumarin diol (CD) are obtained. Initially, pre‐polymers based on different amounts of coumarin (5, 15, and 25 mol%) and 1,6‐hexamethylene diisocyanate are prepared to obtain PUs with a large incorporation of CD and high molecular weight. The pre‐polymer is posterior reacted with poly(ε‐caprolactone) diol (PCL‐diol), either with molecular weight = 530 or 2000 g mol–1. The thermal stabilities of the PUs are studied using thermogravimetric analysis. Polymers with a higher content of CD present higher stability. The thermal transitions and the mechanical response are analyzed using differential scanning calorimetry and strain‐stress tests, respectively. Moreover, the photo‐reversibility of CD‐based PUs is followed by UV absorption. In general, photo‐dimerization induces better mechanical properties of the final PUs. Materials obtained with short PCL‐diol ( = 530 g mol–1) and the highest amount of CD present higher reversibility processes. Therefore, these polymers are promising for application as coating systems.
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Evaluation of accuracy and precision in polymer gel dosimetry
Authors: Maynard Evan , Hilts Michelle , Heath Emily , Jirasek Andrew 
Published: December 2016

PurposeTo assess the overall reproducibility and accuracy of an X‐ray computed tomography (CT) polymer gel dosimetry (PGD) system and investigate what effects the use of generic, interbatch, and intrabatch gel calibration have on dosimetric and spatial accuracy.MethodsA N‐isopropylacrylamide (NIPAM)‐based gel formulation optimized for X‐ray CT gel dosimetry was used, and the results over four different batches of gels were analyzed. All gels were irradiated with three 6 MV beams in a calibration pattern at both the bottom and top of the dosimeter. Postirradiation CT images of the gels were processed using background subtraction, image averaging, adaptive mean filtering, and remnant artifact removal. The gel dose distributions were calibrated using a Monte Carlo (Vancouver Island Monte Carlo system) calculated dose distribution of the calibration pattern. Using the calibration results from all gels, an average or “generic” calibration curve was calculated and this generic calibration curve was used to calibrate each of the gels within the sample. For each of the gels, the irradiation pattern at the bottom of the dosimeter was also calibrated using the irradiation pattern at the top of the dosimeter to evaluate intragel calibration.ResultsComparison of gel measurements with Monte Carlo dose calculations found excellent dosimetric accuracy when using an average (or generic) calibration with a mean dose discrepancy of 1.8% in the low‐dose gradient region which compared to a “best‐case scenario” self‐calibration method with a mean dose discrepancy of 1.6%. The intragel calibration method investigated produced large dose discrepancies due to differences in dose response at the top and bottom of the dosimeter, but the use of a dose‐dependent correction reduced these dose errors. Spatial accuracy was found to be excellent for the average calibration method with a mean distance‐to‐agreement (DTA) of 0.63 mm and 99.6% of points with a DTA < 2 mm in high‐dose gradient regions. This compares favorably to the self‐calibration method which produced a mean DTA of 0.61 mm and 99.8% of points with a DTA < 2 mm. Gamma analysis using a 3%/3 mm criterion also found good agreement between the gel measurement and Monte Carlo dose calculation when using either the average calibration or self‐calibration methods (96.8% and 98.2%, respectively).ConclusionsAn X‐ray CT PGD system was evaluated and found to have excellent dosimeteric and spatial accuracy when compared to Monte Carlo dose calculations and the use of generic and interbatch calibration methods were found to be effective. The establishment of the accuracy and reproducibility of this system provides important information for clinical implementation.