bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical modeling of multiphase, turbulent galactic disks with star formation feedback
Authors: Kim Chang-Goo , Ostriker Eve C. , Kim Woong-Tae 
Published: March 2015

AbstractStar formation is self-regulated by its feedback that drives turbulence and heats the gas. In equilibrium, the star formation rate (SFR) should be directly related to the total (thermal plus turbulent) midplane pressure and hence the total weight of the diffuse gas if energy balance and vertical dynamical equilibrium hold simultaneously. To investigate this quantitatively, we utilize numerical hydrodynamic simulations focused on outer-disk regions where diffuse atomic gas dominates. By analyzing gas properties at saturation, we obtain relationships between the turbulence driving and dissipation rates, heating and cooling rates, the total midplane pressure and the total weight of gas, and the SFR and the total midplane pressure. We find a nearly linear relationship between the SFR and the midplane pressure consistent with the theoretical prediction.
Optical Surveys of Galaxies: Past, Present, and Future
Authors: Okamura Sadanori 
Published: March 2015

AbstractA brief history is given of wide area optical surveys of galaxies and resulting catalogs, starting from the Shapley-Ames Catalog through POSS and CfA surveys to modern surveys. Scientific impacts of large surveys are described in terms of the complete sample, large homogeneous samples, and new discoveries. Upcoming and future ambitious surveys are also mentioned. A recent review of surveys in various wavelength regions is given by Djorgovski et al. (2012).
LSST Data Management: Entering the Era of Petascale Optical Astronomy
Authors: Juric Mario , Tyson Tony 
Published: March 2015

AbstractThe Large Synoptic Survey Telescope (LSST; Ivezic et al.2008, http://lsst.org) is a planned, large-aperture, wide-field, ground-based telescope that will survey half the sky every few nights in six optical bands from 320 to 1050 nm. It will explore a wide range of astrophysical questions, ranging from discovering killer asteroids, to examining the nature of dark energy. LSST will produce on average 15 terabytes of data per night, yielding an (uncompressed) data set of 200 petabytes at the end of its 10-year mission. Dedicated HPC facilities (with a total of 320 TFLOPS at start, scaling up to 1.7 PFLOPS by the end) will process the image data in near real time, with full-dataset reprocessing on annual scale. The nature, quality, and volume of LSST data will be unprecedented, so the data system design requires petascale storage, terascale computing, and gigascale communications.
Kernel PCA for Supernovae Photometric Classification
Authors: Ishida Emille E. O. 
Published: March 2015

AbstractIn this work, we propose the use of Kernel Principal Component Analysis (KPCA) combined with k = 1 nearest neighbor algorithm (1NN) as a framework for supernovae (SNe) photometric classification. It is specially recommended for analysis where the user is interested in high purity in the final SNe Ia sample. Our method provide good purity results in all data sample analyzed, when SNR⩾5. As a consequence, we can state that if a sample as the Supernova Photometric Classification Challenge were available today, we would be able to classify ≈ 15% of the initial data set with purity higher than 90%. This makes our algorithm ideal for a first approach to an unlabeled data set or to be used as a complement in increasing the training sample for other algorithms. Results are sensitive to the information contained in each light curve, as a consequence, higher quality data (low noise) leads to higher successful classification rates.
Unidentified Infrared Emission Features
Authors: Joblin Christine 
Published: March 2015

AbstractWhen referring to unidentified infrared emission features, one has in mind the series of aromatic IR bands (AIBs) between 3.3 and 15 μm that are observed in emission in many environments where UV photons irradiate interstellar matter. These bands are now used by astronomers to classify objects and characterize local physical conditions. However, a deep analysis cannot proceed without understanding the properties of the band carriers. Large polycyclic aromatic hydrocarbon molecules are attractive candidates but interstellar species are still poorly characterized. Various studies emphasize the need for tackling the link between molecular aromatic species, aliphatic material and very small carbonaceous grains. Other unidentified emission features such as the 6.9, 21 and 30 μm bands could be involved in the evolutionary scenario.
Prebiotic Matter in Space
Authors: Ehrenfreund Pascale , Elsaesser Andreas , Groen J. 
Published: March 2015

AbstractA significant number of molecules that are used in contemporary biochemistry on Earth are found in interstellar and circumstellar regions as well as solar system environments. In particular small solar system bodies hold clues to processes that formed our solar system. Comets, asteroids, and meteorite delivered extraterrestrial material during the heavy bombardment phase ~3.9 billion years ago to the young planets, a process that made carbonaceous material available to the early Earth. In-depth understanding of the organic reservoir in different space environments as well as data on the stability of organic and prebiotic material in solar system environments are vital to assess and quantify the extraterrestrial contribution of prebiotic sources available to the young Earth.
Laboratory Simulations of Physico-chemical Processes under Interstellar Conditions
Authors: Caro Guillermo M. Muñoz 
Published: March 2015

AbstractThe accretion and desorption of gas molecules on cold dust grains play an important role in the evolution of dense clouds and circumstellar regions around YSOs. Some of the gas molecules detected in interstellar clouds were likely synthesized in icy dust grains and ejected to the gas. But in dark cloud interiors, with temperatures as low as 10–20 K, thermal desorption is negligible and a non-thermal mechanism like ice photodesorption is required. Reactions in the ice matrix are driven by energetic processing such as photon and ion irradiation. In circumstellar regions the photon flux (UV and X-rays) is expected to be significantly higher than in dense cloud interiors, icy grain mantles present in the outer parts will experience significant irradiation. The produced radicals lead to the formation of new species in the ice, some of them of prebiotic interest. Laboratory simulations of these processes are required for their understanding. The new ultra-high vacuum set-ups introduce some important improvements.
Laboratory Analogues of the Carbonaceous Dust: Synthesis of Soot-like Materials and their Properties
Authors: Pino T. , Carpentier Y. , Féraud G. , Bréchignac Ph. , Brunetto R. , d'Hendecourt L. , Dartois E. , Rouzaud J.-N. 
Published: March 2015

AbstractCarbonaceous cosmic dust is observed through infrared spectroscopy either in absorption or in emission and the details of the spectral features are believed to shed some light on its structure and finally enable the study of its life cycle. Other spectral domains also contain some information, as does the UV bump at 217 nm. In order to progress on the understanding of these spectral features, many laboratory works are devoted to the production and characterization of laboratory analogues. Generally several analytical tools are used in combination to better analyse the intimate structure of the analogues and the influence of the nanostructuration on the spectral properties. In this proceeding We will focus on the elaboration of new spectral parameters that enables the nanostructuration of the carriers of the AIBs to be traced.
CTA site characterization: a contribution on Sky Background Brightness
Authors: de la Vega Gonzalo , García Beatriz , Maya Javier , Mancilla Alexis , Rosemblat Ezequiel 
Published: March 2015

AbstractThe Cherenkov Telescope Array (CTA) is an international project for which more than 1000 scientists from 27 countries work together to install two observatories, one in the southern hemisphere and the other in the north, to study gamma-ray radiation. Argentina is a candidate site for one of the observatories, and to characterize proposed sites, one must study the sky background brightness. This critical point must be studied with care. Nearest cities can be a decisive factor in determining where to locate an observatory in our times.
IAU Resolution 2009 B5 - Commission 50 Draft Action Plan - Presentation and Discussion
Authors: Green R. F. 
Published: March 2015

AbstractIAU Resolution 2009 B5 calls on IAU members to protect the public's right to an unpolluted night sky as well as the astronomical quality of the sky around major research observatories. The multi-pronged approach of Commission 50 includes working with the lighting industry for appropriate products from the solid state revolution, arming astronomers with training and materials for presentation, selective endorsement of key protection issues, cooperation with several other IAU commissions for education and outreach, and provision of clear quantitative priorities for outdoor lighting standards.
Stereochemical bias introduced during RNA synthesis modulates the activity of phosphorothioate siRNAs
Authors: Jahns Hartmut , Roos Martina , Imig Jochen , Baumann Fabienne , Wang Yuluan , Gilmour Ryan , Hall Jonathan 
Published: March 2015

AbstractAn established means of improving the pharmacokinetics properties of oligoribonucleotides (ORNs) is to exchange their phosphodiester linkages for phosphorothioates (PSs). However, this strategy has not been pursued for small interfering RNAs (siRNAs), possibly because of sporadic reports that PS siRNAs show reduced inhibitory activity. The PS group is chiral at phosphorous (Rp/Sp centres), and conventional solid-phase synthesis of PS ORNs produces a population of diastereoisomers. Here we show that the choice of the activating agent for the synthesis of a PS ORN influences theRp/Sp ratio of PS linkages throughout the strand. Furthermore, PS siRNAs composed of ORNs with a higher fraction ofRp centres show greater resistance to nucleases in serum and are more effective inhibitors in cells than theirSp counterparts. The finding that a stereochemically biased population of ORN diastereoisomers can be synthesized and exploited pharmacologically is important because uniform PS modification of siRNAs may provide a useful compromise of their pharmacokinetics and pharmacodynamics properties in RNAi therapeutics.
Switching from Visibility to Invisibility via Fano Resonances: Theory and Experiment
Authors: Rybin Mikhail V. , Filonov Dmitry S. , Belov Pavel A. , Kivshar Yuri S. , Limonov Mikhail F. 
Published: March 2015

AbstractSubwavelength structures demonstrate many unusual optical properties which can be employed for engineering of a new generation of functional metadevices, as well as controlled scattering of light and invisibility cloaking. Here we demonstrate that the suppression of light scattering for any direction of observation can be achieved for a uniform dielectric object with high refractive index, in a sharp contrast to the cloaking with multilayered plasmonic structures suggested previously. Our finding is based on the novel physics of cascades of Fano resonances observed in the Mie scattering from a homogeneous dielectric rod. We observe this effect experimentally at microwaves by employing high temperature-dependent dielectric permittivity of a glass cylinder with heated water. Our results open a new avenue in analyzing the optical response of high-index dielectric nanoparticles and the physics of cloaking.
Natural high pCO2 increases autotrophy in Anemonia viridis (Anthozoa) as revealed from stable isotope (C, N) analysis
Authors: Horwitz Rael , Borell Esther M. , Yam Ruth , Shemesh Aldo , Fine Maoz 
Published: March 2015

AbstractContemporary cnidarian-algae symbioses are challenged by increasing CO2concentrations (ocean warming and acidification) affecting organisms' biological performance. We examined the natural variability of carbon and nitrogen isotopes in the symbiotic sea anemoneAnemonia viridisto investigate dietary shifts (autotrophy/heterotrophy) along a naturalpCO2gradient at the island of Vulcano, Italy. δ13C values for both algal symbionts (Symbiodinium) and host tissue ofA. viridisbecame significantly lighter with increasing seawaterpCO2. Together with a decrease in the difference between δ13C values of both fractions at the higherpCO2sites, these results indicate there is a greater net autotrophic input to theA. viridiscarbon budget under highpCO2conditions. δ15N values and C/N ratios did not change inSymbiodiniumand host tissue along thepCO2gradient. Additional physiological parameters revealed anemone protein andSymbiodiniumchlorophyllaremained unaltered among sites.Symbiodiniumdensity was similar among sites yet their mitotic index increased in anemones under elevatedpCO2. Overall, our findings show thatA. viridisis characterized by a higher autotrophic/heterotrophic ratio aspCO2increases. The unique trophic flexibility of this species may give it a competitive advantage and enable its potential acclimation and ecological success in the future under increased ocean acidification.
Substitution of tryptophan 89 with tyrosine switches the DNA binding mode of PC4
Authors: Huang Jinguang , Zhao Yanxiang , Liu Huaian , Huang Dan , Cheng Xiankun , Zhao Wensheng , Taylor Ian A. , Liu Junfeng , Peng You-Liang 
Published: March 2015

AbstractPC4, a well-known general transcription cofactor, has multiple functions in transcription and DNA repair. Residue W89, is engaged in stacking interactions with DNA in PC4, but substituted by tyrosine in some PC4 orthologous proteins. In order to understand the consequences and reveal the molecular details of this substitution we have determined the crystal structures of the PC4 orthologue MoSub1 and a PC4 W89Y mutant in complex with DNA. In the structure of MoSub1-DNA complex, Y74 interacts directly with a single nucleotide of oligo DNA. By comparison, the equivalent residue, W89 in wild type PC4 interacts with two nucleotides and the base of the second nucleotide has distinct orientation relative to that of the first one. A hydrophobic patch around W89 that favours interaction with two nucleotides is not formed in the PC4 W89Y mutant. Therefore, the change of the surface hydrophobicity around residue 89 results in a difference between the modes of DNA interaction. These results indicate that the conserved Y74 in MoSub1 or W89 in PC4, are not only key residues in making specific interactions with DNA but also required to determine the DNA binding mode of PC4 proteins.
An experimental investigation of evolutionary dynamics in the Rock-Paper-Scissors game
Authors: Hoffman Moshe , Suetens Sigrid , Gneezy Uri , Nowak Martin A. 
Published: March 2015

AbstractGame theory describes social behaviors in humans and other biological organisms. By far, the most powerful tool available to game theorists is the concept of a Nash Equilibrium (NE), which is motivated by perfect rationality. NE specifies a strategy for everyone, such that no one would benefit by deviating unilaterally from his/her strategy. Another powerful tool available to game theorists are evolutionary dynamics (ED). Motivated by evolutionary and learning processes, ED specify changes in strategies over time in a population, such that more successful strategies typically become more frequent. A simple game that illustrates interesting ED is the generalized Rock-Paper-Scissors (RPS) game. The RPS game extends the children's game to situations where winning or losing can matter more or less relative to tying. Here we investigate experimentally three RPS games, where the NE is always to randomize with equal probability, but the evolutionary stability of this strategy changes. Consistent with the prediction of ED we find that aggregate behavior is far away from NE when it is evolutionarily unstable. Our findings add to the growing literature that demonstrates the predictive validity of ED in large-scale incentivized laboratory experiments with human subjects.
The formation of electronically excited species in the human multiple myeloma cell suspension
Authors: Rác Marek , Sedlářová Michaela , Pospíšil Pavel 
Published: March 2015

AbstractIn this study, evidence is provided on the formation of electronically excited species in human multiple myeloma cells U266 in the growth medium exposed to hydrogen peroxide (H2O2). Two-dimensional imaging of ultra-weak photon emission using highly sensitive charge coupled device camera revealed that the addition of H2O2 to cell suspension caused the formation of triplet excited carbonyls 3(R = O)*. The kinetics of 3(R = O)* formation in the real time, as measured by one-dimensional ultra-weak photon emission using low-noise photomultiplier, showed immediate enhancement followed by a slow decay. In parallel to the formation of 3(R = O)*, the formation of singlet oxygen (1O2) in U266 cells caused by the addition of H2O2 was visualized by the imaging of 1O2 using the green fluorescence of singlet oxygen sensor green detected by confocal laser scanning microscopy. Additionally, the formation of 1O2 after the addition of H2O2 to cell suspension was detected by electron paramagnetic resonance spin-trapping spectroscopy using 2,2,6,6-tetramethyl-4-piperidone. Presented results indicate that the addition of H2O2 to cell suspension results in the formation of 3(R = O)* and 1O2 in U266 cell suspension. The contribution of the cell-free medium to the formation of electronically excited species was discussed.
Platelet Rho GTPases–a focus on novel players, roles and relationships
Authors: Goggs Robert , Williams Christopher M. , Mellor Harry , Poole Alastair W. 
Published: March 2015

Rho GTPases are critical for platelet function. Although the roles of RhoA, Rac and Cdc42 are characterized, platelets express other Rho GTPases, whose activities are less well understood. This review summarizes our understanding of the roles of platelet Rho GTPases and focuses particularly on the functions of Rif and RhoG. In human platelets, Rif interacts with cytoskeleton regulators including formins mDia1 and mDia3, whereas RhoG binds SNARE-complex proteins and cytoskeletal regulators ELMO and DOCK1. Knockout mouse studies suggest that Rif plays no critical functions in platelets, likely due to functional overlap with other Rho GTPases. In contrast, RhoG is essential for normal granule secretion downstream of the collagen receptor GPVI. The central defect in RhoG−/− platelets is reduced dense granule secretion, which impedes integrin activation and aggregation and limits platelet recruitment to growing thrombi under shear, translating into reduced thrombus formation in vivo. Potential avenues for future work on Rho GTPases in platelets are also highlighted, including identification of the key regulator for platelet filopodia formation and investigation of the role of the many Rho GTPase regulators in platelet function in both health and disease.
Enhanced locking range technique for divide‐by‐3 differential injection‐locked frequency divider
Authors: Jang Sheng‐Lyang , Lin Chih‐Yuan , Juang Miin‐Horng 
Published: March 2015

A new circuit technique is proposed to enhance the locking range of divide‐by‐3 injection‐locked frequency dividers (ILFDs) implemented using a standard 0.18 μm CMOS process. The ILFD uses a transformer feedback to increase the second harmonic and enhances the conversion efficiency of injection metal–oxide semiconductor field‐effect transistor mixers. The ILFD core consumes 10.8 mW power at the supply voltage of 0.9 V and with a circuit core current of 12 mA. At the incident power of 0 dBm, the measured locking range is 4.2 GHz (37.17%), from the incident frequency 9.2–13.4 GHz.
Low occurrence rates of ubiquitously present leptocephalus larvae in the stomach contents of predatory fish
Authors: Miller Michael J. , Dubosc Jeff , Vourey Elodie , Tsukamoto Katsumi , Allain Valerie 
Published: March 2015

AbstractLeptocephali, the larvae of eels, grow to large sizes and are widely distributed in tropical and subtropical oceans. Their role in oceanic food webs is poorly known because they are rarely reported as food items in fish stomach content studies. Data from 13 years of research on the trophic dynamics of Pacific Ocean predatory fish indicate that among 8746 fish of 76 species/taxa (33 families) that had been feeding, only 16 fish of 6 species had remains of 34 leptocephali in their stomachs. Only 0.013% of the 256 308 total prey items were leptocephalus larvae, and 0.03% of the total prey items were juvenile or adult eels (mostly snipe eels: Nemichthyidae). There were 10 fish of 2 species of lancetfish (Alepisaurus spp., n = 152), 2 rainbow runners (Elagatis bipinnulata, n = 222), and 2 yellowfin tuna (Thunnus albacares, n = 3103) that had leptocephali in their stomach contents, but all except one T. albacares (contained 15 leptocephali) had each eaten ≤3 leptocephali. A swallower, Pseudoscopelus sp., and a frigate tuna, Auxis thazard, had eaten single leptocephali. Twenty-eight bigeye tuna, Thunnus obesus, had eaten 76 juvenile/adult nemichthyid or serrivomerid eels. A literature survey found that only 15 out of 75 examined publications listed leptocephali in the stomach contents of a total of 6 species out of ∼ 42 300 predatory fish of 40 species. The transparency of leptocephali and their apparent mimicry of gelatinous zooplankton could contribute to lower rates of predation. Their soft bodies likely digest rapidly, so although this study and existing literature indicate that leptocephali sometimes contribute to predatory fish diets, particularly for fish that do not exclude gelatinous prey types, and fish with low digestion rates in their stomachs such as lancetfish, their levels of contribution to fish diets and the impacts of predators on eel recruitment remain uncertain.
Statin Treatment and Mortality: Propensity Score-Matched Analyses of 2007–2008 and 2009–2010 Laboratory-Confirmed Influenza Hospitalizations
Authors: Laidler Matthew R. , Thomas Ann , Baumbach Joan , Kirley Pam Daily , Meek James , Aragon Deborah , Morin Craig , Ryan Patricia A. , Schaffner William , Zansky Shelley M. , Chaves Sandra S. 
Published: March 2015

Abstract
Background.  Annual influenza epidemics are responsible for substantial morbidity and mortality. The use of immunomodulatory agents such as statins to target host inflammatory responses in influenza virus infection has been suggested as an adjunct treatment, especially during pandemics, when antiviral quantities are limited or vaccine production can be delayed.
Methods.  We used population-based, influenza hospitalization surveillance data, propensity score-matched analysis, and Cox regression to determine whether there was an association between mortality (within 30 days of a positive influenza test) and statin treatment among hospitalized cohorts from 2 influenza seasons (October 1, 2007 to April 30, 2008 and September 1, 2009 to April 31, 2010).
Results.  Hazard ratios for death within the 30-day follow-up period were 0.41 (95% confidence interval [CI], .25–.68) for a matched sample from the 2007–2008 season and 0.77 (95% CI, .43–1.36) for a matched sample from the 2009 pandemic.
Conclusions.  The analysis suggests a protective effect against death from influenza among patients hospitalized in 2007–2008 but not during the pandemic. Sensitivity analysis indicates the findings for 2007–2008 may be influenced by unmeasured confounders. This analysis does not support using statins as an adjunct treatment for preventing death among persons hospitalized for influenza.