bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-resolution spectropolarimetry of κ Cet: A proxy for the young Sun
Authors: do Nascimento J. D. , Petit P. , Castro M. , de Mello G. F. Porto , Jeffers S. V. , Marsden S. C. , Ribas I. , Guinan E. ,   the Bcool Collaboration
Published: August 2014

Abstractκ1 Cet (HD 20630, HIP 15457, d = 9.16 pc, V = 4.84) is a dwarf star approximately 30 light-years away in the equatorial constellation of Cetus. Among the solar proxies studied in the Sun in Time, κ1 Cet stands out as potentially having a mass very close to solar and a young age. On this study, we monitored the magnetic field and the chromospheric activity from the Ca II H & K lines of κ1 Cet. We used the technique of Least-Square-Deconvolution (LSD, Donati et al. 1997) by simultaneously extracting the information contained in all 8,000 photospheric lines of the echelogram (for a linelist matching an atmospheric model of spectral type K1). To reconstruct a reliable magnetic map and characterize the surface differential rotation of κ1 Cet we used 14 exposures spread over 2 months, in order to cover at least two rotational cycles (Prot ~9.2 days). The Least Square deconvolution (LSD) technique was applied to detect the Zeeman signature of the magnetic field in each of our 14 observations and to measure its longitudinal component. In order to reconstruct the magnetic field geometry of κ1 Cet, we applied the Zeeman Doppler Imaging (ZDI) inversion method. ZDI revealed a structure in the radial magnetic field consisting of a polar magnetic spot. On this study, we present the fisrt look results of a high-resolution spectropolarimetric campaign to characterize the activity and the magnetic fields of this young solar proxy.
The large scale magnetic field of the G0 dwarf HD 206860 (HN Peg)
Authors: Saikia Sudeshna Boro , Jeffers Sandra V. , Petit Pascal , Marsden Stephen , Morin Julien , Reiners Ansgar ,   the Bcool project
Published: August 2014

AbstractHD 206860 is a young planet (HN Peg b) hosting star of spectral type G0V and it has a potential debris disk around it. In this work we measure the longitudinal magnetic field of HD 206860 using spectropolarimetric data and we measure the chromospheric activity using Ca II H&K, H-alpha and Ca II infrared triplet lines.
What controls the large-scale magnetic fields of M dwarfs?
Authors: Gastine T. , Morin J. , Duarte L. , Reiners A. , Christensen U. , Wicht J. 
Published: August 2014

AbstractObservations of active M dwarfs show a broad variety of large-scale magnetic fields encompassing dipole-dominated and multipolar geometries. We detail the analogy between some anelastic dynamo simulations and spectropolarimetric observations of 23 M stars. In numerical models, the relative contribution of inertia and Coriolis force –estimated by the so-called local Rossby number– is known to have a strong impact on the magnetic field geometry. We discuss the relevance of this parameter in setting the large-scale magnetic field of M dwarfs.
Meridional flow velocities for solar-like stars with known activity cycles
Authors: Baklanova Dilyara , Plachinda Sergei 
Published: August 2014

AbstractThe direct measurements of the meridional flow velocities on stars are impossible today. We suppose that the matter on a surface of solar-like stars with stable activity period passes the way equal to 2π R∗ during the stellar Hale cycle. We present here the dependence of meridional flow velocity on Rossby number, which is an effective parameter of the stellar magnetic dynamo.
Constraining Stellar Winds of Young Sun-like Stars
Authors: Johnstone Colin P. , Lüftinger Theresa , Güdel Manuel , Fichtinger Bibiana 
Published: August 2014

AbstractAs part of the project Pathways to Habitability (http://path.univie.ac.at/), we study the properties of the stellar winds of low-mass and Sun-like stars, and their influences on the atmospheres of potentially habitable planets. For this purpose, we combine mapping of stellar magnetic fields with magnetohydrodynamic wind models.
New observations of chemically peculiar stars with ESPaDOnS
Authors: Khalack V. , Yameogo B. , Thibeault C. , LeBlanc F. 
Published: August 2014

AbstractWe present the first results of the estimation of gravity and effective temperature for some poorly studied chemically peculiar stars that were recently observed with the spectropolarimeter ESPaDOnS at CFHT. We have analyzed the spectra of HD71030, HD95608 and HD116235 to determine their radial velocity, vsini and the average abundance of several chemical species. We have also analyzed our results to verify for possible vertical abundance stratification of iron and chromium in these stars.
The Dominion Astrophysical Observatory Magnetic Field Survey (DMFS)
Authors: Bohlender David A. , Monin Dmitry 
Published: August 2014

AbstractIn this paper we present a few results from the first three years of an ongoing survey of globally-ordered magnetic fields in relatively faint (down to V ≈ 9) upper main sequence peculiar stars that we are conducting on the Dominion Astrophysical Observatory (DAO) Plaskett telescope. The DMFS uses the inexpensive DAO polarimeter module, dimaPol, mounted at the Cassegrain focus of the 1.8 m telescope to detect new magnetic stars and determine rotation periods and longitudinal magnetic field curves using medium-resolution (R ≈ 10,000) circular spectropolarimetry of both the Hβ line and metal lines in an approximately 280 Å wide wavelength region centered on Hβ. By concentrating on the mid-B to A-type peculiar stars, the DMFS provides an extension to the ‘Magnetism in Massive Stars’ (MIMES) Large Program which concentrated on similar field detections in more massive stars.
Roadmap on the theoretical work of BinaMIcS
Authors: Mathis Stéphane , Neiner Coralie , Alecian Evelyne , Wade Gregg ,   the BinaMIcS collaboration
Published: August 2014

AbstractWe review the different theoretical challenges concerning magnetism in interacting binary or multiple stars that will be studied in the BinaMIcS (Binarity and Magnetic Interactions in various classes of Stars) project during the corresponding spectropolarimetric Large Programs at CFHT and TBL. We describe how completely new and innovative topics will be studied with BinaMIcS such as the complex interactions between tidal flows and stellar magnetic fields, the MHD star-star interactions, and the role of stellar magnetism in stellar formation and vice versa. This will strongly modify our vision of the evolution of interacting binary and multiple stars.
The dichotomy between strong and ultra-weak magnetic fields among intermediate-mass stars
Authors: Lignières François , Petit Pascal , Aurière Michel , Wade Gregg A. , Böhm Torsten 
Published: August 2014

AbstractUntil recently, the detection of magnetic fields at the surface of intermediate-mass main-sequence stars has been limited to Ap/Bp stars, a class of chemically peculiar stars. This class represents no more than 5-10% of the stars in this mass range. This small fraction is not explained by the fossil field paradigm that describes the Ap/Bp type magnetism as a remnant of an early phase of the star-life. Also, the limitation of the field measurements to a small and special group of stars is obviously a problem to study the effect of the magnetic fields on the stellar evolution of a typical intermediate-mass star.Thanks to the improved sensitivity of a new generation of spectropolarimeters, a lower bound to the magnetic fields of Ap/Bp stars, a two orders of magnitude desert in the longitudinal magnetic field and a new type of sub-gauss magnetism first discovered on Vega have been identified. These advances provide new clues to understand the origin of intermediate-mass magnetism as well as its influence on stellar evolution. In particular, a scenario has been proposed whereby the magnetic dichotomy between Ap/Bp and Vega-like magnetism originate from the bifurcation between stable and unstable large scale magnetic configurations in differentially rotating stars. In this paper, we review these recent observational findings and discuss this scenario.
Magnetic fields in single late-type giants in the Solar vicinity: How common is magnetic activity on the giant branches?
Authors: Konstantinova-Antova Renada , Aurière Michel , Charbonnel Corinne , Drake Natalia , Wade Gregg , Tsvetkova Svetla , Petit Pascal , Schröder Klaus-Peter , Lèbre Agnes 
Published: August 2014

AbstractWe present our first results on a new sample containing all single G, K and M giants down to V = 4 mag in the Solar vicinity, suitable for spectropolarimetric (Stokes V) observations with Narval at TBL, France. For detection and measurement of the magnetic field (MF), the Least Squares Deconvolution (LSD) method was applied (Donati et al. 1997) that in the present case enables detection of large-scale MFs even weaker than the solar one (the typical precision of our longitudinal MF measurements is 0.1-0.2 G). The evolutionary status of the stars is determined on the basis of the evolutionary models with rotation (Lagarde et al. 2012; Charbonnel et al., in prep.) and fundamental parameters given by Massarotti et al. (1998). The stars appear to be in the mass range 1-4 M⊙, situated at different evolutionary stages after the Main Sequence (MS), up to the Asymptotic Giant Branch (AGB).The sample contains 45 stars. Up to now, 29 stars are observed (that is about 64% of the sample), each observed at least twice. For 2 stars in the Hertzsprung gap, one is definitely Zeeman detected. Only 5 G and K giants, situated mainly at the base of the Red Giant Branch (RGB) and in the He-burning phase are detected. Surprisingly, a lot of stars ascending towards the RGB tip and in early AGB phase are detected (8 of 13 observed stars). For all Zeeman detected stars v sin i is redetermined and appears in the interval 2-3 km/s, but few giants with MF possess larger v sin i.
Polarimetry of R Aqr and PN M2-9
Authors: Navarro Silvana G. , Sabin Laurence , Ramírez Julio , Hiriart David 
Published: August 2014

AbstractThe bipolar or more complex morphology observed in planetary nebulae have been explained by two principal hypothesis: by the existence of a companion and an accreting disk or by the effects of magnetic field, (or a combination of both). Symbiotics are binary systems and some of them show morphologies similar to those observed on planetary nebulae. This fact could support the binary hypothesis for PNe. We have therefore performed polarimetric observations of symbiotic systems and some planetary nebulae in order, first to detect linear polarisation with POLIMA at the San Pedro Mártir observatory, and ultimately to prove the existence and physical properties of those disks. We present here the first results of a project dedicated to the analysis of the polarisation observed in evolved objects starting with the PN M2-9 and R Aqr.
Hall Effect in Neutron Star Crusts
Authors: Gourgouliatos K. N. , Cumming A. 
Published: August 2014

AbstractThe crust of Neutron Stars can be approximated by a highly conducting solid crystal lattice. The evolution of the magnetic field in the crust is mediated through Hall effect, namely the electric current is carried by the free electrons of the lattice and the magnetic field lines are advected by the electron fluid. Here, we present the results of a time-dependent evolution code which shows the effect Hall drift has in the large-scale evolution of the magnetic field. In particular we link analytical predictions with simulation results. We find that there are two basic evolutionary paths, depending on the initial conditions compared to Hall equilibrium. We also show the effect axial symmetry combined with density gradient have on suppressing turbulent cascade.
Axisymmetric and stationary magnetic field structures in neutron star crusts under various boundary conditions
Authors: Fujisawa Kotaro , Kisaka Shota 
Published: August 2014

AbstractWe have calculated many Hall equilibrium states within the neutron star crust under various boundary conditions in order to investigate the influences of the boundary conditions clearly. We have found two important features of these solutions. First, the magnitude of the core magnetic fields affects the toroidal to total magnetic field energy ratio within the crust (Et/E). If the core magnetic fields are vanished, the crustal toroidal magnetic fields become weak and the typical energy ratio is only Et / E ~ 0.1%. If the core magnetic fields are strong, however, the crustal toroidal magnetic fields become strong and the typical ratio reaches Et / E ~ 15%. Second, the core toroidal magnetic fields and the twisted magnetosphere around the star make the size of the crustal toroidal magnetic field regions large. Therefore if the strong core magnetic fields have strong toroidal component, both strength and size of the crustal toroidal magnetic fields become large. These results show that the Hall MHD evolutions would be deeply affected by both inner and outer boundary conditions.
Magnetars: the explosive character of a small class of strongly magnetized neutron stars
Authors: Rea Nanda 
Published: August 2014

AbstractI will review our current knowledge on the most magnetic objects in the Universe, a small sample of neutron stars called magnetars. The powerful persistent high energy emission and the flares from these strongly magnetized (1015 Gauss) neutron stars are providing crucial information about the physics involved at these extremes conditions, reserving us many unexpected surprises.
NSMAXG: A new magnetic neutron star spectral model in XSPEC
Authors: Ho Wynn C. G. 
Published: August 2014

AbstractThe excellent sensitivity of X-ray telescopes, such as Chandra and XMM-Newton, is ideal for the study of cooling neutron stars, which can emit at these energies. In order to exploit the wealth of information contained in the high quality data, a thorough knowledge of the radiative properties of neutron star atmospheres is necessary. A key factor affecting photon emission is magnetic fields, and neutron stars are known to have strong surface magnetic fields. Here I briefly describe our latest work on constructing magnetic (B ≥ 1010 G) atmosphere models of neutron stars and the NSMAXG implementation of these models in XSPEC. Our results allow for more robust extractions of neutron star parameters from observations.
The future of evolutionary economics is in a vision from the past
Authors: STOELHORST J. W. 
Published: August 2014

AbstractThis essay comments on discussions of the future of evolutionary economics by Winter (2014) and Witt (2014). I agree with their assessment of evolutionary economics as a theoretically fragmented field that has had little success in effecting a paradigm shift in mainstream economics. However, I question if such a paradigm shift should be the primary goal of evolutionary economists. I argue that evolutionary economists could increase their impact if they would be willing and able to recast themselves as evolutionary social scientists. This was the vision for economics that Veblen held out more than a century ago. I lay out the theoretical building blocks for realizing this vision available today.
Stable Two-Dimensional Conductance Switch of Polyaniline Molecule Connecting to Graphene Nanoribbons
Authors: Fan Zhi-Qiang , Chen Ke-Qiu 
Published: August 2014

AbstractIncorporating the characteristics of the single-layer graphene nanoribbon and the polyaniline molecule, we theoretically design a two-dimensional molecular device and investigate its transport properties by applying nonequilibrium Green's functions in combination with density-functional theory. The calculated results reveal that the arrangements of frontier molecular orbitals and the energy gap between the HOMO and the LUMO of an isolated polyaniline molecule are different between its two isolable states: full reduced leucoemeraldine base and full oxidized pernigraniline base. When a polyaniline molecule connects to two graphene nanoribbons as a two-dimensional molecular device, the conductance of its full oxidized pernigraniline base is much higher than the conductance of its full reduced leucoemeraldine base. The switch ratios of two bases' currents almost maintain a constant value before 0.8 V. In other word, the conductance switch behavior in our device is stable in a big bias region which makes it have a broader application in future logic and memory devices.
Flaviviral RNAs: weapons and targets in the war between virus and host
Authors: Bidet Katell , Garcia-Blanco Mariano A. 
Published: August 2014

Flaviviruses are a genus of (+)ssRNA (positive ssRNA) enveloped viruses that replicate in the cytoplasm of cells of diverse species from arthropods to mammals. Many are important human pathogens such as DENV-1–4 (dengue virus types 1–4), WNV (West Nile virus), YFV (yellow fever virus), JEV (Japanese encephalitis virus) and TBEV (tick-borne encephalitis). Given their RNA genomes it is not surprising that flaviviral life cycles revolve around critical RNA transactions. It is these we highlight in the present article. First, we summarize the mechanisms governing flaviviral replication and the central role of conserved RNA elements and viral protein–RNA interactions in RNA synthesis, translation and packaging. Secondly, we focus on how host RNA-binding proteins both benefit and inhibit flaviviral replication at different stages of their life cycle in mammalian hosts. Thirdly, we cover recent studies on viral non-coding RNAs produced in flavivirus-infected cells and how these RNAs affect various aspects of cellular RNA metabolism. Together, the article puts into perspective the central role of flaviviral RNAs in modulating both viral and cellular functions.
Gallium phosphide as a new material for anodically bonded atomic sensors
Authors: Dural Nezih , Romalis Michael V. 
Published: August 2014

Miniaturized atomic sensors are often fabricated using anodic bonding of silicon and borosilicate glass. Here we describe a technique for fabricating anodically bonded alkali-metal cells using GaP and Pyrex. GaP is a non-birefringent semiconductor that is transparent at alkali-metal resonance wavelengths, allowing new sensor geometries. GaP also has a higher thermal conductivity and lower He permeability than borosilicate glass and can be anodically bonded below 200 °C, which can also be advantageous in other vacuum sealing applications.
Free-energy inference from partial work measurements in small systems
Authors: Ribezzi-Crivellari Marco , Ritort Felix 
Published: August 2014

Significance
Fluctuation relations (FRs) provide general results about work (or total entropy production) distributions in nonequilibrium systems. However, in many cases the full work is not measurable and only partial work measurements are possible. The latter do not fulfill a FR and cannot be used to extract free-energy differences from irreversible work measurements. We show how FRs can be used to infer the full work distribution from partial work measurements. We illustrate the inference process, using dual-trap optical tweezers where two forces (one per trap) are measured, and we can access both the full and the partial work distributions. We derive a set of results of direct interest to single-molecule scientists and, more generally, to physicists and biophysicists.
Temporal and spatial organization of ESCRT protein recruitment during HIV-1 budding
Authors: Bleck Marina , Itano Michelle S. , Johnson Daniel S. , Thomas V. Kaye , North Alison J. , Bieniasz Paul D. , Simon Sanford M. 
Published: August 2014

Significance
HIV-1 infection and the associated disease AIDS are a major cause of human death worldwide with no vaccine or cure available. The assembly of virus particles involves numerous host and viral proteins that are potential therapeutic targets. We used high-resolution microscopy techniques to investigate how the virus hijacks cellular proteins to enable the release of virions from an infected cell. We show with high temporal and spatial resolution that components of the host endosomal sorting complex required for transport (ESCRT) machinery are recruited to the neck of the assembling virus to facilitate scission of the link between the virus and the cell.
Comparative Swimming Performance of Five Catostomus Species and Roundtail Chub
Authors: Underwood Zachary E. , Myrick Christopher A. , Compton Robert I. 
Published: August 2014

Abstract.—Decreased habitat connectivity and competition with nonnative species have led to declines of many freshwater fishes. An understanding of swimming performance can aid in the conservation of these fishes; however, acquiring sufficient numbers of rare and threatened species to perform swimming studies can be logistically challenging and ecologically costly. In order to determine whether swimming data for common sucker species may be substituted for that of similar but rare sucker species, we compared the swimming abilities of two rare western catostomids, Bluehead Sucker Catostomus discobolus and Flannelmouth Sucker C. latipinnis, as well as one catostomid with a less well understood status, Mountain Sucker C. platyrhynchus, with those of the common White Sucker C. commersonii and Longnose Sucker C. catostomus. We also examined Roundtail Chub Gila robusta because they are often included in conservation efforts involving Bluehead Sucker and Flannelmouth Sucker. The critical swimming velocities (Ucrit), standardized by body length, of Bluehead Sucker and Longnose Sucker differed significantly from those of White Sucker. However, there was no significant difference between the Ucrit of Mountain Sucker, Flannelmouth Sucker, and White Sucker. During constant acceleration trials, Bluehead Sucker exhibited the greatest swimming ability, reaching a mean maximum velocity of 4.56 ± 1.28 body lengths per second (BL/s; mean ± SD), followed by Mountain Sucker (3.56 ± 0.57 BL/s), White Sucker (3.28 ± 0.90 BL/s), Longnose Sucker (2.97 ± 0.31 BL/s), and Flannelmouth Sucker (2.22 ± 0.42 BL/s). Additionally, key behavioral differences in the swimming behaviors of the fishes studied were observed. We conclude that swimming performance data for common White Sucker should not be used in place of data for rarer species. Comprehensive swimming studies should be conducted on individual sucker species before implementing conservation strategies involving fish passageways or barriers.
Received November 6, 2013; accepted February 28, 2014