bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cluster observations of non–time continuous magnetosonic waves
Authors: Walker Simon N. , Demekhov Andrei G. , Boardsen Scott A. , Ganushkina Natalia Y. , Sibeck David G. , Balikhin Michael A. 
Published: September 2016

AbstractEquatorial magnetosonic waves are normally observed as temporally continuous sets of emissions lasting from minutes to hours. Recent observations, however, have shown that this is not always the case. Using Cluster data, this study identifies two distinct forms of these non–temporally continuous emissions. The first, referred to as rising tone emissions, are characterized by the systematic onset of wave activity at increasing proton gyroharmonic frequencies. Sets of harmonic emissions (emission elements) are observed to occur periodically in the region ±10° off the geomagnetic equator. The sweep rate of these emissions maximizes at the geomagnetic equator. In addition, the ellipticity and propagation direction also change systematically as Cluster crosses the geomagnetic equator. It is shown that the observed frequency sweep rate is unlikely to result from the sideband instability related to nonlinear trapping of suprathermal protons in the wave field. The second form of emissions is characterized by the simultaneous onset of activity across a range of harmonic frequencies. These waves are observed at irregular intervals. Their occurrence correlates with changes in the spacecraft potential, a measurement that is used as a proxy for electron density. Thus, these waves appear to be trapped within regions of localized enhancement of the electron density.
Neural coupling of cooperative hand movements after stroke: role of ipsilateral afference
Authors: Schrafl‐Altermatt Miriam , Dietz Volker 
Published: September 2016

AbstractWe investigated the role of ipsilateral ascending pathways in the neural coupling underlying cooperative hand movements of stroke subjects. Ipsi‐ and contralateral somatosensory evoked potentials (SSEP) were recorded following ulnar nerve stimulation during cooperative and non‐cooperative hand movements. The amplitude ratio, that is, ipsilateral divided by contralateral amplitude, was highest during the cooperative task when the affected arm was stimulated, reflecting an enhanced afferent volley to the unaffected hemisphere. The presence of ipsilateral SSEP from the paretic arm was closely related with the patients' hand function. This shows for the first time a laterality in ascending pathways after unilateral stroke and implies an involvement of the unaffected hemisphere in the control of paretic hand movements.
RNAi prevents and reverses phenotypes induced by mutant human ataxin‐1
Authors: Keiser Megan S. , Monteys Alejandro Mas , Corbau Romuald , Gonzalez‐Alegre Pedro , Davidson Beverly L. 
Published: September 2016

ObjectiveSpinocerebellar ataxia type 1 is an autosomal dominant fatal neurodegenerative disease caused by a polyglutamine expansion in the coding region of ATXN1. We showed previously that partial suppression of mutant ataxin‐1 (ATXN1) expression, using virally expressed RNAi triggers, could prevent disease symptoms in a transgenic mouse model and a knockin mouse model of the disease, using a single dose of virus. Here, we set out to test whether RNAi triggers targeting ATXN1 could not only prevent, but also reverse disease readouts when delivered after symptom onset.MethodsWe administered recombinant adeno‐associated virus (rAAV) expressing miS1, an artificial miRNA targeting human ATXN1 mRNA (rAAV.miS1), to a mouse model of spinocerebellar ataxia type 1 (SCA1; B05 mice). Viruses were delivered prior to or after symptom onset at multiple doses. Control B05 mice were treated with rAAVs expressing a control artificial miRNA, or with saline. Animal behavior, molecular phenotypes, neuropathology, and magnetic resonance spectroscopy were done on all groups, and data were compared to wild‐type littermates.ResultsWe found that SCA1 phenotypes could be reversed by partial suppression of human mutant ATXN1 mRNA by rAAV.miS1 when delivered after symptom onset. We also identified the therapeutic range of rAAV.miS1 that could prevent or reverse disease readouts.InterpretationSCA1 disease may be reversible by RNAi therapy, and the doses required for advancing this therapy to humans are delineated. Ann Neurol 2016;80:754–765
Neuroinflammatory component of gray matter pathology in multiple sclerosis
Authors: Herranz Elena , Giannì Costanza , Louapre Céline , Treaba Constantina A. , Govindarajan Sindhuja T. , Ouellette Russell , Loggia Marco L. , Sloane Jacob A. , Madigan Nancy , Izquierdo‐Garcia David , Ward Noreen , Mangeat Gabriel , Granberg Tobias , Klawiter Eric C. , Catana Ciprian , Hooker Jacob M. , Taylor Norman , Ionete Carolina , Kinkel Revere P. , Mainero Caterina 
Published: September 2016

ObjectiveIn multiple sclerosis (MS), using simultaneous magnetic resonance–positron emission tomography (MR‐PET) imaging with 11C‐PBR28, we quantified expression of the 18kDa translocator protein (TSPO), a marker of activated microglia/macrophages, in cortex, cortical lesions, deep gray matter (GM), white matter (WM) lesions, and normal‐appearing WM (NAWM) to investigate the in vivo pathological and clinical relevance of neuroinflammation.MethodsFifteen secondary‐progressive MS (SPMS) patients, 12 relapsing–remitting MS (RRMS) patients, and 14 matched healthy controls underwent 11C‐PBR28 MR‐PET. MS subjects underwent 7T
‐weighted imaging for cortical lesion segmentation, and neurological and cognitive evaluation. 11C‐PBR28 binding was measured using normalized 60‐ to 90‐minute standardized uptake values and volume of distribution ratios.ResultsRelative to controls, MS subjects exhibited abnormally high 11C‐PBR28 binding across the brain, the greatest increases being in cortex and cortical lesions, thalamus, hippocampus, and NAWM. MS WM lesions showed relatively modest TSPO increases. With the exception of cortical lesions, where TSPO expression was similar, 11C‐PBR28 uptake across the brain was greater in SPMS than in RRMS. In MS, increased 11C‐PBR28 binding in cortex, deep GM, and NAWM correlated with neurological disability and impaired cognitive performance; cortical thinning correlated with increased thalamic TSPO levels.InterpretationIn MS, neuroinflammation is present in the cortex, cortical lesions, deep GM, and NAWM, is closely linked to poor clinical outcome, and is at least partly linked to neurodegeneration. Distinct inflammatory‐mediated factors may underlie accumulation of cortical and WM lesions. Quantification of TSPO levels in MS could prove to be a sensitive tool for evaluating in vivo the inflammatory component of GM pathology, particularly in cortical lesions. Ann Neurol 2016;80:776–790
Synthesis of organically bridged trialkoxysilanes bearing acetoxymethyl groups and applications to reverse osmosis membranes
Authors: Yamamoto Kazuki , Ohshita Joji , Mizumo Tomonobu , Kanezashi Masakoto , Tsuru Toshinori 
Published: September 2016

New bridged trialkoxysilanes bearing acetoxymethyl groups were synthesized by double hydrosilylation of 1,6‐diacetoxy‐2,4‐butadiyne, using two equivalents of triethoxysilane and a metal catalyst. With a Ru catalyst, the reaction proceeded via anti‐addition to provide BTES‐Ac‐a as a single isomer, while a similar reaction with a Pt or Rh catalyst provided an isomeric mixture of syn‐adducts BTES‐Ac‐b. Reverse osmosis (RO) silica membranes were prepared by the sol–gel process with BTES‐Ac‐a and BTES‐Ac‐b and the membranes were examined with respect to water desalination using a 2000 ppm NaCl aqueous solution. NaCl rejection of the membranes increased to reach 96% at the early stage of the RO experiments. However, the rejection decreased gradually to 85% after 70 and 200 h for BTES‐Ac‐a and BTES‐Ac‐b, respectively, due to hydrolytic decomposition of the silica network during the experiments. In contrast, a membrane prepared from copolymerization of BTES‐Ac‐a with ethane‐bridged bistrialkoxysilane (BTES‐E1) showed improved stability towards hydrolysis with stable NaCl rejection of 96% with higher water permeance (3.5 × 10−13 m3 m−2 s−1 Pa−1) than that of a membrane prepared by homopolymerization of BTES‐E1 (2.7 × 10−14 m3 m−2 s−1 Pa−1) reported previously.
Improvement of the short‐ and long‐term mechanical properties of injection‐molded poly(etheretherketone) and hydroxyapatite nanocomposites
Authors: Marcomini Andre Luis , Rego Bruna Turino , Suman Bretas Rosario Elida 
Published: September 2016

ABSTRACTNanocomposites of polyetheretherketone (PEEK) and hydroxyapatite (HA) nanoparticles treated with a silane coupling agent were successfully prepared by twin screw extrusion and injection molding. Some of the samples were annealed after the injection molding. The silane treatment promoted an improvement of the short‐ and long‐term mechanical properties of the nanocomposites. A higher stress and a six times higher deformation at break and a higher impact strength were observed in the silane‐treated nanocomposites when compared to the nontreated ones. The number of cycles to fail of the treated nanocomposites was almost 200% higher than the number of cycles to fail of the nontreated samples. The treatment also decreased the glass transition temperature and amount of crystallinity of the samples. This improvement in mechanical properties obtained from the silane treatment was attributed to the strengthening of the PEEK/HA interfacial bond, to the plasticization of the PEEK matrix by silane oligomers produced during the processing and to a better dispersion of the HA nanoparticles within the PEEK matrix. Samples annealing, however, diminished all these properties due to the increase in crystallinity. Studies of the short‐ and long‐term mechanical properties of these nanocomposites under physiological conditions and of the proliferation of stem cells are under way. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44476.
Some aspects of cool main sequence star ages derived from stellar rotation (gyrochronology)
Authors: Barnes S. A. , Spada F. , Weingrill J. 
Published: September 2016

AbstractRotation periods for cool stars can be measured with good precision by monitoring starspot light modulation. Observations have shown that the rotation periods of dwarf stars of roughly solar metallicity have such systematic dependencies on stellar age and mass that they can be used to derive reliable ages, a procedure called gyrochronology. We review the method and show illustrative cases, including recent ground‐ and space‐based data. The age uncertainties approach 10 % in the best cases, making them a valuable complement to, and constraint on, asteroseismic or other ages.
Asteroseismic age determination for dwarfs and giants
Authors: Silva Aguirre V. , Serenelli A. M. 
Published: September 2016

AbstractAsteroseismology can make a substantial contribution to our understanding of the formation history and evolution of our Galaxy by providing precisely determined stellar properties for thousands of stars in different regions of the Milky Way. We present here the different sets of observables used in determining asteroseismic stellar properties, the typical level of precision obtained, the current status of results for ages of dwarfs and giants, and the improvements than can be expected in the near future in the context of Galactic archaeology.
Non‐LTE iron abundances in cool stars: The role of hydrogen collisions
Authors: Ezzeddine R. , Merle Th. , Plez B. 
Published: September 2016

AbstractIn the aim of determining accurate iron abundances in stars, this work is meant to empirically calibrate H‐collision crosssections with iron where no quantum mechanical calculations have been published yet. Thus, a new iron model atom has been developed which includes hydrogen collisions for excitation, ionization, and charge transfer processes. We show that collisions with hydrogen leading to charge transfer are important for an accurate non‐LTE modeling. We apply our calculations on several benchmark stars including the Sun, the metal‐rich star α Cen A, and the metal‐poor star HD 140283.
The Apache Point Observatory Galactic Evolution Experiment (APOGEE) and its successor, APOGEE‐2
Authors: Majewski S. R. 
Published: September 2016

AbstractThe Apache Point Observatory Galactic Evolution Experiment (APOGEE) of Sloan Digital Sky Survey III (SDSS‐III) has produced a large catalog of high resolution (R = 22 500), high quality (S/N > 100), infrared (H ‐band) spectra for stars throughout all stellar populations of the Milky Way, including in regions veiled by significant dust opacity. APOGEE's half million spectra collected on > 163 000 unique stars, with time series information via repeat visits to each star, are being applied to numerous problems in stellar populations, Galactic astronomy, and stellar astro‐physics. From among the early results of the APOGEE project – which span from measurements of Galactic dynamics, to multi‐element chemical maps of the disk and bulge, new views of the interstellar medium, explorations of stellar companions, the chemistry of star clusters, and the discovery of rare stellar species – I highlight a few results that demonstrate APOGEE's unique ability to sample and characterize the Galactic disk and bulge. Plans are now under way for an even more ambitious successor to APOGEE: the six‐year, dual‐hemisphere APOGEE‐2 project. Both phases of APOGEE feature a strong focus on targets having asteroseismological measurements from either Kepler or CoRoT, from which it is possible to derive relatively precise stellar ages. The combined APOGEE and APOGEE‐2 databases of stellar chemistry, dynamics and ages constitute an unusually comprehensive, systematic and homogeneous resource for constraining models of Galactic evolution.
Chemical abundance gradients from open clusters in the Milky Way disk: Results from the APOGEE survey
Authors: Cunha K. , Frinchaboy P.M. , Souto D. , Thompson B. , Zasowski G. , Allende Prieto C. , Carrera R. , Chiappini C. , Donor J. , García‐Hernández A. , García Pérez A. E. , Hayden M. R. , Holtzman J. , Jackson K. M. , Johnson J. A. , Majewski S. R. , Mészáros S. , Meyer B. , Nidever D. L. , O'Connell J. , Schiavon R. P. , Schultheis M. , Shetrone M. , Simmons A. , Smith V. V. , Zamora O. 
Published: September 2016

AbstractMetallicity gradients provide strong constraints for understanding the chemical evolution of the Galaxy. We report on radial abundance gradients of Fe, Ni, Ca, Si, and Mg obtained from a sample of 304 red‐giant members of 29 disk open clusters, mostly concentrated at galactocentric distances between ∼8–15 kpc, but including two open clusters in the outer disk. The observations are from the APOGEE survey. The chemical abundances were derived automatically by the ASPCAP pipeline and these are part of the SDSS III Data Release 12. The gradients, obtained from least squares fits to the data, are relatively flat, with slopes ranging from –0.026 to –0.033 dex kpc–1 for the α ‐elements [O/H], [Ca/H], [Si/H], and [Mg/H], and –0.035 dex kpc–1 and –0.040 dex kpc–1 for [Fe/H] and [Ni/H], respectively. Our results are not at odds with the possibility that metallicity ([Fe/H]) gradients are steeper in the inner disk (RGC ∼ 7–12 kpc) and flatter towards the outer disk. The open cluster sample studied spans a significant range in age. When breaking the sample into age bins, there is some indication that the younger open cluster population in our sample (log age <8.7) has a flatter metallicity gradient when compared with the gradients obtained from older open clusters.
The CoRoT‐GES Collaboration: Improving red giants spectroscopic surface gravitity and abundances with asteroseismology
Authors: Valentini M. , Chiappini C. , Miglio A. , Montalbán J. , Rodrigues T. , Mosser B. , Anders F. , CoRoT RG Group  , GES Consortium  
Published: September 2016

AbstractNowadays large spectroscopic surveys, like the Gaia‐ESO Survey (GES), provide unique stellar databases for better investigating the formation and evolution of our Galaxy. Great attention must be paid to the accuracy of the basic stellar properties derived: large uncertainties in stellar parameters lead to large uncertainties in abundances, distances and ages. Asteroseismology has a key role in this context: when seismic information is combined with information derived from spectroscopic analysis, highly precise constraints on distances, masses, extinction and ages of red giants can be obtained. In the light of this promising joint action, we started the CoRoT‐GES collaboration. We present a set of 1111 CoRoT stars, observed by GES from December 2011 to July 2014, these stars belong to the CoRoT field LRc01, pointing at the inner Galactic disk. Among these stars, 534 have reliable global seismic parameters. By combining seismic informations and spectroscopy, we derived precise stellar parameters, ages, kinematic and orbital parameters and detailed element abundances for this sample of stars. We also show that, thanks to asteroseismology, we are able to obtain a higher precision than what can be achieved by the standard spectroscopic means. This sample of CoRoT red giants, spanning Galactocentric distances from 5 to 8 kpc and a wide age interval (1–13 Gyr), provides us a representative sample for the inner disk population.
Complementing asteroseismology with 4MOST spectroscopy
Authors: de Jong R. S. , 4MOST Consortium  
Published: September 2016

Abstract4MOST is a wide‐field, high‐multiplex spectroscopic survey facility under development for the VISTA telescope of the European Southern Observatory (ESO). Its main science drivers are in the areas of galactic archeology, high‐energy physics, galaxy evolution and cosmology. 4MOST will in particular provide the spectroscopic complements to the large area surveys coming from space missions like Gaia, eROSITA, Euclid, and PLATO. 4MOST will have an unique operations concept in which 5‐years public surveys from both the consortium and the ESO community will be combined and observed in parallel during each exposure, resulting in more than 25 million spectra of targets spread over a large fraction of the southern sky. As a dedicated spectroscopic survey facility with a large field‐of‐view, a high multiplex that can be reconfigured quickly, and with a broad wavelength coverage, 4MOST is particularly well suited to complement the upcoming asteroseismology space missions like TESS and PLATO. Here we show that, by dedicating the observing time during twilight and poor observing conditions to bright stars, 4MOST will obtain resolution R > 18000 spectra of nearly all stars brighter than 12th magnitude at Dec <30° every 2 years. 4MOST is also expected to spectroscopically complement any fainter asteroseismology target tobe observed with PLATO. These observations will provide a chemical characterization of nearly all stars tobe observed with the TESS and PLATO missions and place any planets found in a full chemo‐dynamical context of the star formation history of the Galaxy, yield very accurate ages and masses for all stars that can be characterized with asteroseismology, and allow removal of contaminants from target samples (e.g., spectroscopic binaries).
Galactic stellar populations with APOGEE and Kepler
Authors: Johnson J. A. , APOKASC collaboration  
Published: September 2016

AbstractUnderstanding the history of baryons is key to understanding galaxy formation, as galaxies with very similar stellar mass and/or dark matter halo mass can have markedly different morphologies in their stellar light. Stars are a useful way to study this history, because properties such as their composition, age, and orbital motion can map galaxy formation and evolution. Lightcurves from the Kepler mission, both original and extended, provide asteroseismic parameters, such as Δν and νmax, and rotation periods. The high‐resolution near‐infrared APOGEE spectroscopic survey is observing an extensive sample of red giants and cool dwarfs in both the Kepler and K2 fields to provide composition and effective temperature measurements. These spectroscopic and seismic parameters can be combined to yield ages, important for dissecting the history of the Milky Way. Results based on this combination have already been published in the first APOKASC catalog. Among the interesting results about stellar populations so far are the presence of a large metallicity spread in the young secondary red clump population at the solar circle, the identification of young, yet α‐rich stars, and the detection of a field blue straggler descendant. The K2 fields along the ecliptic will extend the possibilities of these techniques to new lines of sight in the Galaxy and provide a much more representative sample of Galactic populations with seismic and spectroscopic information.
SOD1 dimerization monitoring using a novel split NanoLuc, NanoBit
Authors: Oh‐hashi Kentaro , Hirata Yoko , Kiuchi Kazutoshi 
Published: September 2016

In the present study, we applied a highly sensitive NanoLuc‐based technology to understand the status of superoxide dismutase 1 (SOD1) within mammalian cells. Two fragments of NanoLuc (NanoBit), large N‐terminal and small C‐terminal regions, were fused with wild‐type (wt) and mutant human SOD1 (hSOD1) genes and transfected into cells. Luciferase activity through NanoBit assembly was only detected in NanoBit‐tagged wtSOD1‐expressing cells. Furthermore, the developed NanoLuc system was used to investigate the role of protein‐protein interactions in the pathogenesis of amyotrophic lateral sclerosis (ALS). In addition to SOD1, we also applied this NanoBit system for detecting the dimerization of wild‐type, M337V‐mutated human TAR‐binding protein 43 kDa (hTDP43) and its cleaved C‐terminal fragment (TDP25M337V) as well as their interactions with SOD1. Luciferase activities of NanoBit‐tagged mutant SOD1, TDP43, or TDP25 were negligible. Finally, we found that a zinc chelator partially reduced the luciferase activity of NanoBit‐wtSOD1. Collectively, these results show that the present assay is sensitive and convenient to appreciate ALS and to develop useful agents for the modulation of SOD1 conformation.
Future Challenges in Heterogeneous Catalysis: Understanding Catalysts under Dynamic Reaction Conditions
Authors: Kalz Kai F. , Kraehnert Ralph , Dvoyashkin Muslim , Dittmeyer Roland , Gläser Roger , Krewer Ulrike , Reuter Karsten , Grunwaldt Jan‐Dierk 
Published: September 2016

AbstractIn the future, (electro‐)chemical catalysts will have to be more tolerant towards a varying supply of energy and raw materials. This is mainly due to the fluctuating nature of renewable energies. For example, power‐to‐chemical processes require a shift from steady‐state operation towards operation under dynamic reaction conditions. This brings along a number of demands for the design of both catalysts and reactors, because it is well‐known that the structure of catalysts is very dynamic. However, in‐depth studies of catalysts and catalytic reactors under such transient conditions have only started recently. This requires studies and advances in the fields of 1) operando spectroscopy including time‐resolved methods, 2) theory with predictive quality, 3) kinetic modelling, 4) design of catalysts by appropriate preparation concepts, and 5) novel/modular reactor designs. An intensive exchange between these scientific disciplines will enable a substantial gain of fundamental knowledge which is urgently required. This concept article highlights recent developments, challenges, and future directions for understanding catalysts under dynamic reaction conditions.