bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Surface and Lower Atmosphere of Titan from HST Observations
Authors: Smith Peter H. , Lemmon M. , Tomasko M. 
Published: March 2016

AbstractIn 1994 the HST camera acquired images of Titan during 14 visits throughout a 16—day rotation period. These images were mosaicked to produce surface maps of albedo variations at several wavelengths (0.67, 0.94, and 1.04 microns) which revealed a bright, continent-sized feature on Titan’s leading face (Smith, Lemmon, & Lorenz 1996). Also, the observing program was designed as a search for clouds and their motions; no clouds were conclusively identified. Other observing sessions in subsequent years performed by our group and others have resulted in numerous observations through WFPC2, STIS, and NICMOS. Additional maps have now been made in the 2—micron region that show a very similar surface albedo to the 0.94—micron map (T. Owen, private communication). Models based on these data sets are used to understand the lower atmosphere and surface as seen through the overlying hazes; seasonal variations resulting in a north-south asymmetry of the haze layer are also being studied.
First Images of Titan at 1.3 Micron with the Adaptive Optics PUEO System at the CFHT
Authors: Coustenis Athena , Gendron Eric , Lai Oliver , Véran Jean-Pierre , Woillez Julien , Combes Michel , Fusco Thierry , Mugnier Laurent 
Published: March 2016

AbstractThe first images of Titan at 1.3 micron were obtained with the PUEO adaptive optics system at the CFHT, on October 26 1998. We have also obtained images of Titan at 1.6 micron. Our diffraction-limited images (about 10 independent resolution elements or 20 pixels on the disk) pertain to Titan’s leading hemisphere. We have used narrow-band filters centered outside (1.29, 1.6 µm) and in the wings (1.18, 1.64 µm) of the methane bands, so as to be able to subtract the atmospheric contribution from our data. Images of Titan’s surface show the large equatorial region to be bright at both wavelengths. Combined with previous spectroscopic and imaging data, our findings are compatible with the presence of a mountainous plateau, covered with bright ice (perhaps methane), near the equator of Titan and with hydrocarbon deposits in the darker areas.
Recycling of Ions in Mercury’s Magnetosphere
Authors: Killen Rosemary , Potter Andrew , Sarantos Menelaos , Reiff Patricia 
Published: March 2016

AbstractTo determine the relative rates of ion recycling to the surface and loss of ions to the solar wind, we followed 3,500 Na ions in a tight grid of magnetic and electric fields at Mercury. We conclude that up to 60% of the photoions launched on the dayside near the surface will re-impact the dayside. For a dawn – dusk electric field, we find that most of the returning ions impact the dayside. This will be the case for a southward IMF. Photoions do not impact the dayside with sufficient energy to cause secondary sputtering, but on the nightside they will be accelerated to keV energies, and may cause secondary sputtering there.
The Role of Magnetic Helicity in Solar Flares
Authors: Linton Mark G. 
Published: March 2016

AbstractHelicity in coronal magnetic fields, often occurring in the form of twisted or sheared fields, can provide surplus energy which is available for release in solar flares. In this paper, several models of how this extra, non-potential, energy can be released will be reviewed. For example, twisted flux tubes can release excess energy via the kink instability. Or energy can be released via a transfer of helicity between different magnetic tubes. For untwisted field, the mutual helicity between flux tubes provides a measure of the shear in the fields, and therefore how much energy is available for release in a flare. For twisted flux tubes, the twist helicity of each tube in combination with the mutual helicity between the tubes dictate what type of reconnection the tubes can undergo and how much energy is available for release. Measuring the helicity of coronal active regions, and studying how this helicity affects magnetic energy release is therefore vital for our understanding of and our ability to predict solar flares.
Globular Clusters in Early-Type Galaxies with GMOS
Authors: Bridges Terry , Beasley Mike , Faifer Favio , Forbes Duncan , Forte Juan , Gebhardt Karl , Hanes Dave , Sharpies Ray , Zepf Steve 
Published: March 2016

AbstractWe present recent results from our long-term Gemini/GMOS study of globular clusters (GCs) in early-type galaxies. To date, we have obtained photometry and spectroscopy for GCs in NGCs 3379, 4649, 524, 7332, and IC 1459. We find a clear bimodality in the NGC 4649 GC color distribution, with the fraction of blue/red clusters increasing with galacto-centric radius. We derive ages and metallicities for 22 GCs in NGC 3379, finding that most of the clusters appear old (10–15 Gyr); however, there is a group of 4 metal-rich, younger clusters with ages of 2–6 Gyr. The NGC 3379 GC velocity dispersion decreases with radius, as does the inferred (local) mass-to-light ratio: there is no evidence for a dark matter halo in NGC 3379 based on our GC data.
Magnetic Fields in Galaxy Clusters
Authors: Govoni Federica , Murgia Matteo 
Published: March 2016

AbstractMagnetic fields in galaxy clusters can be investigated using a variety of techniques. Recent studies including radio halos, Inverse Compton hard X-ray emissions and Faraday rotation measure, are briefly outlined. A numerical approach for investigating cluster magnetic fields strength and structure is presented. It consists of producing simulated rotation measure, radio halo images, and radio halo polarization, obtained from 3-dimensional multi-scale cluster magnetic field models, and comparing with observations.
The Formation and Evolution of Star Clusters and Galaxies
Authors: Zepf Stephen E. 
Published: March 2016

AbstractThis paper addresses the questions of what we have learned about how and when dense star clusters form, and what studies of star clusters have revealed about galaxy formation and evolution. One important observation is that globular clusters are observed to form in galaxy mergers and starbursts in the local universe, which both provides constraints on models of globular cluster formation, and suggests that similar physical conditions existed when most early-type galaxies and their globular clusters formed in the past. A second important observation is that globular cluster systems typically have bimodal color distributions. This was predicted by merger models, and indicates an episodic formation history for elliptical galaxies. A third and very recent result is the discovery of large populations of intermediate age globular clusters in several elliptical galaxies through the use of optical to near-infrared colors. These provide an important link between young cluster systems observed in starbursts and mergers and old cluster systems. This continuum of ages of the metal-rich globular cluster systems also indicates that there is no special age or epoch for the formation of the metal-rich globular clusters, which comprise about half of the cluster population. The paper concludes with a brief discussion of recent results on the globular cluster – low-mass X-ray binary connection.
Comparing Chemical Abundances of the Damped Lyα Systems and Metal-Poor Stars
Authors: Prochaska Jason X. 
Published: March 2016

AbstractI briefly draw comparisons between the fields of damped Lyα and metal-poor stellar abundances. In particular, I examine their complementary age-metallicity relations and comparisons between the damped Lyα and dwarf galaxy abundance patterns. Regarding the latter, I describe a series of problems concerning associating high z damped Lyα systems with present-day dwarfs.
The Cosmic Evolution of Quasars
Authors: Jackson Carole , Wall Jasper , Shaver Peter , Kellermann Ken , Hook Isobel 
Published: March 2016

AbstractThe form of the quasar luminosity function and its redshift dependence to z~1 has long been established; powerful evolution is required so that by z=1 there is an increase of order 102 – 103 in the space density of the most luminous sources. However it is more difficult to deduce the form of the LF at high redshifts. In this contribution we discuss how a sample of relatively bright radio sources has been used to determine the high-redshift behavior of the radiodoud quasar luminosity function, and the particular advantages of using a radio-selected sample. Our results illustrate how radio-loud quasar samples can be an efficient probe of the high-redshift. Universe.
Rosetta Asteroid Candidates
Authors: Barucci M. Antonietta , Fulchignoni Marcello , Birlan Mirel , Vernazza Pierre , Dotto Elisabetta , Doressoundiram Alain 
Published: March 2016

AbstractThe new scenario of the Rosetta mission to comet 67/P Churyumov-Gerasimenko (launch on February 2004), includes as baseline the fly-by of one or two asteroids. Several asteroids are now possible fly-by candidates (single or double) within the available resources. Other candidates whose fly-bys require a larger Δv can be also considered if the Rosetta interplanetary orbit insertion will cost less Δv.All the up to date available information on the possible targets are discussed in this report.
Astrophysics at X-Ray Spectral Resolution 1000
Authors: Brickhouse Nancy S. 
Published: March 2016

AbstractThe Chandra gratings exceed a resolving power R = 1000, but only at the longest wavelengths and with relatively low effective areas. Recent X-ray observations of cool stars illustrate the problem of line blending at different resolutions and give a good sense of what we will routinely be able to measure with Constellation-X, provided it has high enough spectral resolution. We also expect new diagnostics from weak lines and line profiles. Support for this work is provided by NASA NAS8-39083 to SAO for the CXC and LTSA NAG5-3559.
Dynamic versus Static Designation
Authors: Pourbaix Dimitri 
Published: March 2016

AbstractShould the designation of the components of a system reflect its known hierarchy or rather the history of their discovery? With the recent progress in, say, radial velocity techniques, the old famous order in which components were used to be discovered (inner to outer components for spectroscopic systems) is somehow altered. In the past, capital letters were used for visual companions and lower case letters for spectroscopic components and there was almost no overlap between the two groups. The situation has changed from both ends of the orbital period interval. In some rare cases, we think letters should be re-distributed and re-assigned in order to reflect the structure of the system. With an adequate choice of the data structure, such a change of the companion designation is rather straightforward to implement in modern databases (such as SB9). The only foreseen drawback is related to the cross-reference with some old papers: the letter B would not designate the same component in a 1970 paper and in a 2003 one. For instance, the former secondary of an SB2 system might now refer to the unseen companion and an astrometric triple.
Entwicklung und Schwerpunkte in der psychologischen Hochbegabungsforschung
Authors: Preckel Franzis , Krampen Günter 
Published: March 2016

Zusammenfassung. Auf der Grundlage einer quantitativen szientometrischen Analyse der deutsch- und englischsprachigen Publikationen zum Thema Hochbegabung aus den deutschsprachigen Ländern (PSYNDEX) und der Publikationen aus den primär angloamerikanischen Ländern (PsycINFO) analysieren wir Entwicklung und Schwerpunkte der psychologischen Hochbegabungsforschung von 1980 bis 2014. Im Vergleich liegt die Anzahl dieser Publikationen (PSYNDEX: 1.066; PsycINFO: 8.572) bei einem Fünftel der Menge zum Thema Geistige Behinderung / Intellektuelle Entwicklungsstörung. Die Gesamtmenge an Publikationen zu Hochbegabung zeigt in beiden Datenbanken einen Boom in den 1980er Jahren sowie seit 2000 einen erneuten deutlichen Zuwachs. Der Anteil empirischer Arbeiten fällt mit 38 % nach PSYNDEX im internationalen Vergleich (54 % nach PsycINFO) geringer aus und ist seit 2000 eher konstant, während er bei englischsprachigen Publikationen leicht ansteigt. Circa 80 % aller Publikationen beschäftigen sich mit Hochbegabten im Schulalter (6 – 17 Jahre), während das Vorschul- sowie das Erwachsenenalter wenig Berücksichtigung finden. Die Publikationen fokussieren vor allem allgemein kognitive, schulische, mathematische, sportliche und musikalische Fähigkeiten, während sich nur wenige bis gar keine Publikationen zu z. B. kreativer, verbaler, nonverbaler oder figural-räumlicher Hochbegabung finden. Implikationen für die Hochbegabungsforschung werden diskutiert.
Blood-based biomarkers of age-associated epigenetic changes in human islets associate with insulin secretion and diabetes
Authors: Bacos Karl , Gillberg Linn , Volkov Petr , Olsson Anders H , Hansen Torben , Pedersen Oluf , Gjesing Anette Prior , Eiberg Hans , Tuomi Tiinamaija , Almgren Peter , Groop Leif , Eliasson Lena , Vaag Allan , Dayeh Tasnim , Ling Charlotte 
Published: March 2016

AbstractAging associates with impaired pancreatic islet function and increased type 2 diabetes (T2D) risk. Here we examine whether age-related epigenetic changes affect human islet function and if blood-based epigenetic biomarkers reflect these changes and associate with future T2D. We analyse DNA methylation genome-wide in islets from 87 non-diabetic donors, aged 26–74 years. Aging associates with increased DNA methylation of 241 sites. These sites cover loci previously associated with T2D, for example,KLF14. Blood-based epigenetic biomarkers reflect age-related methylation changes in 83 genes identified in human islets (for example,KLF14, FHL2, ZNF518BandFAM123C) and some associate with insulin secretion and T2D. DNA methylation correlates with islet expression of multiple genes, includingFHL2,ZNF518B, GNPNAT1andHLTF.Silencing these genes in β-cells alter insulin secretion. Together, we demonstrate that blood-based epigenetic biomarkers reflect age-related DNA methylation changes in human islets, and associate with insulin secretionin vivoand T2D.
Identification of plant vacuolar transporters mediating phosphate storage
Authors: Liu Tzu-Yin , Huang Teng-Kuei , Yang Shu-Yi , Hong Yu-Ting , Huang Sheng-Min , Wang Fu-Nien , Chiang Su-Fen , Tsai Shang-Yueh , Lu Wen-Chien , Chiou Tzyy-Jen 
Published: March 2016

AbstractPlant vacuoles serve as the primary intracellular compartments for inorganic phosphate (Pi) storage. Passage of Pi across vacuolar membranes plays a critical role in buffering the cytoplasmic Pi level against fluctuations of external Pi and metabolic activities. Here we demonstrate that the SPX-MFS proteins, designated as PHOSPHATE TRANSPORTER 5 family (PHT5), also named Vacuolar Phosphate Transporter (VPT), function as vacuolar Pi transporters. Based on 31P-magnetic resonance spectroscopy analysis, Arabidopsis pht5;1 loss-of-function mutants accumulate less Pi and exhibit a lower vacuolar-to-cytoplasmic Pi ratio than controls. Conversely, overexpression of PHT5 leads to massive Pi sequestration into vacuoles and altered regulation of Pi starvation-responsive genes. Furthermore, we show that heterologous expression of the rice homologue OsSPX-MFS1 mediates Pi influx to yeast vacuoles. Our findings show that a group of Pi transporters in vacuolar membranes regulate cytoplasmic Pi homeostasis and are required for fitness and plant growth.
Phosphorylation of EB2 by Aurora B and CDK1 ensures mitotic progression and genome stability
Authors: Iimori Makoto , Watanabe Sugiko , Kiyonari Shinichi , Matsuoka Kazuaki , Sakasai Ryo , Saeki Hiroshi , Oki Eiji , Kitao Hiroyuki , Maehara Yoshihiko 
Published: March 2016

AbstractTemporal regulation of microtubule dynamics is essential for proper progression of mitosis and control of microtubule plus-end tracking proteins by phosphorylation is an essential component of this regulation. Here we show that Aurora B and CDK1 phosphorylate microtubule end-binding protein 2 (EB2) at multiple sites within the amino terminus and a cluster of serine/threonine residues in the linker connecting the calponin homology and end-binding homology domains. EB2 phosphorylation, which is strictly associated with mitotic entry and progression, reduces the binding affinity of EB2 for microtubules. Expression of non-phosphorylatable EB2 induces stable kinetochore microtubule dynamics and delays formation of bipolar metaphase plates in a microtubule binding-dependent manner, and leads to aneuploidy even in unperturbed mitosis. We propose that Aurora B and CDK1 temporally regulate the binding affinity of EB2 for microtubules, thereby ensuring kinetochore microtubule dynamics, proper mitotic progression and genome stability.
Serum complement C3 levels are associated with nonalcoholic fatty liver disease independently of metabolic features in Chinese population
Authors: Xu Chengfu , Chen Yi , Xu Lei , Miao Min , Li Youming , Yu Chaohui 
Published: March 2016

AbstractSerum complement C3 levels are closely associated with obesity and related metabolic disorders. This study aimed to investigate the association between serum complement C3 levels with non-alcoholic fatty liver disease (NAFLD). A cross-sectional study was performed among adults who took their annual health examinations at Zhenhai Lianhua Hospital, Ningbo, China during 2014. We included 7540 participants (5069 men and 2471 women) in this study. NAFLD patients had higher serum complement C3 levels (P < 0.001) and these levels were positively associated with both NAFLD prevalence and severity (P < 0.001). The above association remains true among lean and metabolic syndrome-free participants. Multivariable regression analysis showed that serum complement C3 was independently associated with risk for NAFLD (OR = 5.231; 95% CI: 3.169–8.635). Serum complement C3 level is positively associated with prevalence and severity of NAFLD and this association is independent of obesity and metabolic syndrome.
Fine particulate (PM2.5) dynamics during rapid urbanization in Beijing, 1973–2013
Authors: Han Lijian , Zhou Weiqi , Li Weifeng 
Published: March 2016

AbstractPM2.5 has been given special concern in recent years when the air quality monitoring station started recording. However, long-term PM2.5 concentration dynamic analysis cannot be taken with the limited observations. We therefore estimated the PM2.5 concentration using meteorological visibility data in Beijing. We found that 71 ± 17% of PM10 were PM2.5, which contributed to visibility impairment (y = 332.26e−0.232x; R2 = 0.75, P < 0.05). We then reconstructed a time series of annual PM2.5 from 1973 to 2013 and examined its relationship with urbanization by indicators of population, gross domestic production (GDP), energy consumption and number of vehicles. Concluded that 1) Meteorological conditions were not the major cause of PM2.5 increase from 1973 to 2013; 2) With population and GDP growth, PM2.5 increased significantly (R2 = 0.5917, P < 0.05; R2 = 0.5426, P < 0.05); 3) Intensive human activity could change air quality in a short period, as observed changes in the correlations of PM2.5 concentration with energy consumption and number of vehicles before and after 2004, respectively. The success of this research provides an easy way in reconstructing long-term PM2.5 concentration with limited PM2.5 observation and meteorological visibility and insight the impact of urbanization on air quality.
Mutant GDF5 enhances ameloblast differentiation via accelerated BMP2-induced Smad1/5/8 phosphorylation
Authors: Liu Jia , Saito Kan , Maruya Yuriko , Nakamura Takashi , Yamada Aya , Fukumoto Emiko , Ishikawa Momoko , Iwamoto Tsutomu , Miyazaki Kanako , Yoshizaki Keigo , Ge Lihong , Fukumoto Satoshi 
Published: March 2016

AbstractBone morphogenetic proteins (BMPs) regulate hard tissue formation, including bone and tooth. Growth differentiation factor 5 (GDF5), a known BMP, is expressed in cartilage and regulates chondrogenesis and mutations have been shown to cause osteoarthritis. Notably, GDF5 is also expressed in periodontal ligament tissue; however, its role during tooth development is unclear. Here, we used cell culture andin vivoanalyses to determine the role of GDF5 during tooth development. GDF5 and its associated BMP receptors are expressed at the protein and mRNA levels during postnatal tooth development, particularly at a stage associated with enamel formation. Furthermore, whereas BMP2 was observed to induce evidently the differentiation of enamel-forming ameloblasts, excess GDF5 induce mildly this differentiation. A mouse model harbouring a mutation in GDF5 (W408R) showed enhanced enamel formation in both the incisors and molars, but not in the tooth roots. Overexpression of the W408R GDF5 mutant protein was shown to induce BMP2-mediated mRNA expression of enamel matrix proteins and downstream phosphorylation of Smad1/5/8. These results suggest that mutant GDF5 enhances ameloblast differentiation via accelerated BMP2-signalling.
KIR2DL2/2DL3-E35 alleles are functionally stronger than -Q35 alleles
Authors: Bari Rafijul , Thapa Rajoo , Bao Ju , Li Ying , Zheng Jie , Leung Wing 
Published: March 2016

AbstractKIR2DL2 and KIR2DL3 segregate as alleles of a single locus in the centromeric motif of the killer cell immunoglobulin-like receptor (KIR) gene family. Although KIR2DL2/L3 polymorphism is known to be associated with many human diseases and is an important factor for donor selection in allogeneic hematopoietic stem cell transplantation, the molecular determinant of functional diversity among various alleles is unclear. In this study we found that KIR2DL2/L3 with glutamic acid at position 35 (E35) are functionally stronger than those with glutamine at the same position (Q35). Cytotoxicity assay showed that NK cells from HLA-C1 positive donors with KIR2DL2/L3-E35 could kill more target cells lacking their ligands than NK cells with the weaker -Q35 alleles, indicating better licensing of KIR2DL2/L3+ NK cells with the stronger alleles. Molecular modeling analysis reveals that the glutamic acid, which is negatively charged, interacts with positively charged histidine located at position 55, thereby stabilizing KIR2DL2/L3 dimer and reducing entropy loss when KIR2DL2/3 binds to HLA-C ligand. The results of this study will be important for future studies of KIR2DL2/L3-associated diseases as well as for donor selection in allogeneic stem cell transplantation.
Direct observation of intermediate states in model membrane fusion
Authors: Keidel Andrea , Bartsch Tobias F. , Florin Ernst-Ludwig 
Published: March 2016

AbstractWe introduce a novel assay for membrane fusion of solid supported membranes on silica beads and on coverslips. Fusion of the lipid bilayers is induced by bringing an optically trapped bead in contact with the coverslip surface while observing the bead’s thermal motion with microsecond temporal and nanometer spatial resolution using a three-dimensional position detector. The probability of fusion is controlled by the membrane tension on the particle. We show that the progression of fusion can be monitored by changes in the three-dimensional position histograms of the bead and in its rate of diffusion. We were able to observe all fusion intermediates including transient fusion, formation of a stalk, hemifusion and the completion of a fusion pore. Fusion intermediates are characterized by axial but not lateral confinement of the motion of the bead and independently by the change of its rate of diffusion due to the additional drag from the stalk-like connection between the two membranes. The detailed information provided by this assay makes it ideally suited for studies of early events in pure lipid bilayer fusion or fusion assisted by fusogenic molecules.