bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE EVOLUTION OF ANCIENT MAYA EXCHANGE SYSTEMS: AN ETYMOLOGICAL STUDY OF ECONOMIC VOCABULARY IN THE MAYAN LANGUAGE FAMILY
Authors: Speal C. Scott 
Published: August 2014

AbstractThis article presents a cultural reconstruction of ancient Maya economic development derived through etymological study of exchange-related terms in Mayan languages. It applies the results of historical linguistic analysis to archaeological and epigraphic data in order to gain insight into Maya economic prehistory. Cognitive spheres examined include generalized exchange, reciprocation, appropriation and vertical transfers of goods and labor, open commerce, and material valuables. Among the most poignant implications of the results are the antiquity of commerce and its rather extended evolutionary trajectory. Indicators of intense commercialization, however, are few and rather late. Widespread recognition of several elements of the diverse complex of Contact period Mesoamerican valuables can be traced only to the latter part of the Late Formative period or afterward. Evidence of formalized market systems—specifically linking commerce to towns and architectural plazas—appears only late in the Classic period. Terms associated with the hierarchical appropriation of goods and labor appear earlier and are more persistent and stable over time. In particular, there is a single widespread root for tribute obligation apparently subsuming tax, plunder, and work debt all under a single term, as well as evidence for the great antiquity of formalized servitude. Finally, various forms of general reciprocity and gifting are, as might be expected, shown to be of great diversity, complexity, and antiquity. In the course of analysis, several recent models of Mayan language interaction and diversification are examined and evaluated, and a slightly revised linguistic chronology is suggested that better reconciles linguistic data with archaeological facts as they are currently known. The results also have interesting implications for proto-Mayan geographical origins.
ECONOMY, EXCHANGE, AND POWER: NEW EVIDENCE FROM THE LATE CLASSIC MAYA PORT CITY OF CANCUEN
Authors: Demarest Arthur A. , Andrieu Chloé , Torres Paola , Forné Mélanie , Barrientos Tomás , Wolf Marc 
Published: August 2014

AbstractThe site of Cancuen held a strategic position as “head of navigation” of the Pasión River and the physical nexus of land and river routes between the southern highlands, the Maya lowlands, and the transversal route to Tabasco and Veracruz. For that reason, the well-defined ports of Cancuen were critical to both Classic Maya highland/lowland commerce and interactions with the far west. All aspects of Cancuen were related to its role as a port city. By the late eighth century, evidence suggests that in the site epicenter peninsula ports and other aspects of the economy were elite controlled and supervised, based on associated architectural complexes, artifacts, imports, and placement. Recent evidence indicates that, in addition to previously discussed long-distance exchange in exotics such as jade and pyrite, Cancuen also was involved in very large-scale obsidian transport and production, as well as probable exchange of other piedmont commodities such as cacao, cotton, salt, achiote (Bixa orellana), and vanilla.Distribution of architectural, epigraphic, and iconographic evidence and an administrative/ritual palace all indicate growing roles for nobles in these economic activities, particularly the ports. It would appear that, as elsewhere, nobles were taking a more direct mercantile role and that many aspects of themultepalsystem of power, characteristic of Postclassic period societies, were already in place at Cancuen by the late eighth century. The failure of Cancuen's early transition to a Terminal Classic political economy may be related to its dependence on highland resources and overextended trade networks.
Parent and child perspectives on family out-of-home eating: a qualitative analysis
Authors: McGuffin Lynn E , Price Ruth K , McCaffrey Tracy A , Hall Glenn , Lobo Alan , Wallace Julie MW , Livingstone M Barbara E 
Published: August 2014

AbstractObjectiveTo (i) explore the factors influencing family out-of-home (OH) eating events and (ii) identify possible opportunities for food businesses to support families in making healthier OH choices.DesignFocus group discussions were conducted with parents (six to eight participants per group) and friendship pair discussions (informal interviews with two children who are friends) were conducted with children (5–12 years) throughout the island of Ireland. Both discussions were audio-recorded and analysed using a thematic content analysis.SettingEight focus groups and sixteen friendship pairs were conducted in Northern Ireland and sixteen focus groups and thirty-two friendship pairs were conducted in the Republic of Ireland.SubjectsPurposive sampling was used to recruit a sample of non-related parents and children that represented equal numbers of gender, age, socio-economic status and demographic backgrounds.Results:The main, overarching theme was that families perceived OH eating to be a treat, while health was not currently a key priority for many parents and children. Children were reported to have most responsibility for their own food choice decisions in this environment, with taste and food neophobia having the greatest influences. Parents believed that if food businesses could meet parent and child priorities in addition to health influences, e.g. change cooking methods, and increase flexibility, then families would be more likely to patronise these establishments.ConclusionsThe entire family OH eating experience needs to be considered when developing public health interventions and this research has highlighted key opportunities that caterers could employ to support healthier family OH food choices.
Multi-Day Passions and J. S. Bach'sChristmas Oratorio, BWV248
Authors: MELAMED DANIEL R. 
Published: August 2014

ABSTRACTCommentators have long sought models for the decision by Bach and his anonymous librettist to spread theChristmas Oratorio's narration over twelve days. None of the most commonly proposed models can be shown with certainty to have been performed over more than two days; it appears that the supposed tradition of multi-day Christmas oratorios is invented. In fact there were models for this feature of theChristmas Oratorio: Passion settings designed for or adapted to presentation over Holy Week or all of Lent. The practice is documented in five places concentrated in Saxony and Thuringia and involved both newly composed and older works in both liturgical and devotional contexts. A new source reveals a previously unrecognized performance of this kind, of Reinhard Keiser's Brockes setting in Erfurt. Bach is likely to have known of this performance and others of the type, and they were probably a significant influence on the organization and conception of his Christmas piece performed ‘die Heilige Weyhnacht über’ in 1734/1735.
THE TRIUMPH OF TIME IN THE EIGHTEENTH CENTURY: HANDEL'SIL TRIONFO DEL TEMPOAND HISTORICAL CONCEPTIONS OF MUSICAL TEMPORALITY
Authors: TAYLOR BENEDICT 
Published: August 2014

ABSTRACTMusic is routinely held to be in a privileged position to reflect a particular historical consciousness of time and human temporality. This notion appears itself to be historical, in that it arises from the ‘temporalization’ of time widely attested to have occurred in Western Europe during the eighteenth century. Accordingly, numerous commentators have argued that music becomes increasingly temporalized across the century. Yet if music may convey human temporality without mediation, it remains unclear to what extent ‘pre-temporalized’ works from the early eighteenth century may be taken as temporally significant, given that the notion of time is not supposed to be such an issue during this period. This essay examines the methodological issues attendant to the claim for music's intrinsic historical temporality through an examination of a piece that appears explicitly to thematize the idea of time: Handel's oratorio-cantataIl trionfo del Tempo, which exists in three different versions spanning the fifty years between 1707 and 1757. Although my reading raises questions about the epistemological security of any claim for music's (or indeed language's) expression of historical temporality ‘as it really was’, I argue that a hermeneutic engagement with this problem is both valuable and indeed necessary for understanding music of the period.
The role of magnetic fields in pre-main sequence stars
Authors: Hussain Gaitee A. J. , Alecian Evelyne 
Published: August 2014

AbstractStrong, kilo-Gauss, magnetic fields are required to explain a range of observational properties in young, accreting pre-main sequence (PMS) systems. We review the techniques used to detect magnetic fields in PMS stars. Key results from a long running campaign aimed at characterising the large scale magnetic fields in accreting T Tauri stars are presented. Maps of surface magnetic flux in these systems can be used to build 3-D models exploring the role of magnetic fields and the efficiency with which magnetic fields can channel accretion from circumstellar disks on to young stars. Long-term variability in T Tauri star magnetic fields strongly point to a dynamo origin of the magnetic fields. Studies are underway to quantify how changes in magnetic fields affect their accretion properties. We also present the first results from a new programme that investigates the evolution of magnetic fields in intermediate mass (1.5–3M⊙) pre-main sequence stars as they evolve from being convective T Tauri stars to fully radiative Herbig AeBe stars.
V4046 Sgr: X-rays from accretion shock
Authors: Argiroffi C. , Maggio A. , Montmerle T. , Huenemoerder D. , Alecian E. , Audard M. , Bouvier J. , Damiani F. , Donati J.-F. , Gregory S. , Güdel M. , Hussain G. , Kastner J. , Sacco G. G. 
Published: August 2014

AbstractWe present results of the X-ray monitoring of V4046 Sgr, a close classical T Tauri star binary, with both components accreting material. The 360 ks long XMM observation allowed us to measure the plasma densities at different temperatures, and to check whether and how the density varies with time. We find that plasma at temperatures of 1–4 MK has high densities, and we observe correlated and simultaneous density variations of plasma, probed by O VII and Ne IX triplets. These results strongly indicate that all the inspected He-like triplets are produced by high-density plasma heated in accretion shocks, and located at the base of accretion flows.
X-rays from accretion shocks in classical T Tauri stars: 2D MHD modeling and the role of local absorption
Authors: Argiroffi C. , Bonito R. , Orlando S. , Miceli M. , Reale F. , Peres G. , Matsakos T. , Sthelé C. , Ibgui L. 
Published: August 2014

AbstractIn classical T Tauri stars (CTTS) strong shocks are formed where the accretion funnel impacts with the denser stellar chromosphere. Although current models of accretion provide a plausible global picture of this process, some fundamental aspects are still unclear: the observed X-ray luminosity in accretion shocks is order of magnitudes lower than predicted; the observed density and temperature structures of the hot post-shock region are puzzling and still unexplained by models.To address these issues we performed 2D MHD simulations describing an accretion stream impacting onto the chromosphere of a CTTS, exploring different configurations and strengths of the magnetic field. From the model results we then synthesized the X-ray emission emerging from the hot post-shock, taking into account the local absorption due to the pre-shock stream and surrounding atmosphere.We find that the different configurations and strengths of the magnetic field profoundly affect the hot post-shock properties. Moreover the emerging X-ray emission strongly depends also on the viewing angle under which accretion is observed. Some of the explored configuration are able to reproduce the observed features of X-ray spectra of CTTS.
What do weak magnetic fields mean for magnetospheric accretion in Herbig AeBe star+disk systems?
Authors: Aarnio A. N. , Monnier J. D. , Harries T. J. , Acreman D. M. 
Published: August 2014

AbstractIn the presently favored picture of star formation, mass is transferred from disk to star via magnetospheric accretion and out of the system via magnetically driven outflows. This magnetically mediated mass flux is a fundamental process upon which the evolution of the star, disk, and forming planetary system depends. Our current understanding of these processes is heavily rooted in young solar analogs, T Tauri Stars (TTS). We have come to understand recently, however, that the higher mass pre-main sequence (PMS) Herbig AeBe (HAeBe) stars have dramatically weaker dipolar fields than their lower mass counterparts. We present our current observational and theoretical efforts to characterize magnetospherically mediated mass transfer within HAeBe star+disk systems. We have gathered a rich spectroscopic and interferometric data set for several dozen HAeBe stars in order to measure accretion and mass loss rates, assess wind and magnetospheric accretion properties, and determine how spectral lines and interferometric visibilities are diagnostic of these processes. For some targets, we have observed spectral line variability and will discuss ongoing time-series spectroscopic efforts.
Chemical peculiarities in magnetic and non-magnetic pre-main sequence A and B stars
Authors: Folsom C. P. , Bagnulo S. , Wade G. A. , Landstreet J. D. , Alecian E. 
Published: August 2014

AbstractIn A- and late B-type stars, strong magnetic fields are always associated with Ap and Bp chemical peculiarities. However, it is not clear at what point in a star's evolution those peculiarities develop. Strong magnetic fields have been observed in pre-main sequence A and B stars (Herbig Ae and Be stars), and these objects have been proposed to be the progenitors of Ap and Bp stars. However, the photospheric chemical abundances of these magnetic Herbig stars have not been studied carefully, and furthermore the chemical abundances of 'normal' non-magnetic Herbig stars remain poorly characterized. To investigate this issue, we have studied the photospheric compositions of 23 Herbig stars, four of which have confirmed magnetic fields. Surprisingly, we found that half the non-magnetic stars in our sample show λ Bootis chemical peculiarities to varying degrees. For the stars with detected magnetic fields, we find one chemically normal star, one star with λ Boo peculiarities, one star displaying weak Ap/Bp peculiarities, and one somewhat more evolved star with somewhat stronger Ap/Bp peculiarities. These results suggests that Ap/Bp peculiarities are preceded by magnetic fields, and that these peculiarities develop over the pre-main sequence lives of A and B stars. The incidence of λ Boo stars we find is much higher than that seen on the main sequence. We argue that a selective accretion model for the formation of λ Boo peculiarities is a natural explanation for this remarkably large incidence.
Theoretical evolution of Rossby number for solar analog stars
Authors: Castro Matthieu , Duarte Tharcísyo , do Nascimento José Dias 
Published: August 2014

AbstractMagnetic fields of late-type stars are presumably generated by a dynamo mechanism at the interface layer between the radiative interior and the outer convective zone. The Rossby number, which is related to the dynamo process, shows an observational correlation with activity. It represents the ratio between the rotation period of the star and the local convective turnover time. The former is well determined from observations but the latter is estimated by an empirical iterated function depending on the color index (B-V) and the mixing-length parameter. We computed the theoretical Rossby number of stellar models with the TGEC code, and analyze its evolution with time during the main sequence. We estimated a function for the local convective turnover time corresponding to a mixing-length parameter inferred from a solar model, and compare our results to the estimated Rossby number of 33 solar analogs and twins, observed with the spectropolarimeters ESPaDOnS@CFHT and Narval@LBT.
Bridging planets and stars using scaling laws in anelastic spherical shell dynamos
Authors: Yadav R. K. , Gastine T. , Christensen U. R. , Duarte L. 
Published: August 2014

AbstractDynamos operating in the interiors of rapidly rotating planets and low-mass stars might belong to a similar category where rotation plays a vital role. We quantify this similarity using scaling laws. We analyse direct numerical simulations of Boussinesq and anelastic spherical shell dynamos. These dynamos represent simplified models which span from Earth-like planets to rapidly rotating low-mass stars. We find that magnetic field and velocity in these dynamos are related to the available buoyancy power via a simple power law which holds over wide variety of control parameters.
Starspots Magnetic field by transit mapping
Authors: Válio Adriana , Spagiari Eduardo 
Published: August 2014

AbstractSunspots are important signatures of the global solar magnetic field cycle. It is believed that other stars also present these same phenomena. However, today it is not possible to observe directly star spots due to their very small sizes. The method applied here studies star spots by detecting small variations in the stellar light curve during a planetary transit. When the planet passes in front of its host star, there is a chance of it occulting, at least partially, a spot. This allows the determination of the spots physical characteristics, such as size, temperature, and location on the stellar surface. In the case of the Sun, there exists a relation between the magnetic field and the spot temperature. We estimate the magnetic field component along the line-of-sight and the intensity of sunspots using data from the MDI instrument on board of the SOHO satellite. Assuming that the same relation applies to other stars, we estimate spots magnetic fields of CoRoT-2 and Kepler-17 stars.
The nature and origin of magnetic fields in early-type stars
Authors: Braithwaite Jonathan 
Published: August 2014

AbstractI review our current knowledge of magnetic fields in stars more massive than around 1.5 M⊙, in particular their nature and origin. This includes the strong magnetic fields found in a subset of the population and the fossil field theory invoked to explain them; the subgauss fields detected in Vega and Sirius and their possible origin; and what we can infer about magnetic activity in massive stars and how it might be linked to subsurface convection.
Combining magnetic and seismic studies to constrain processes in massive stars
Authors: Neiner Coralie , Degroote Pieter , Coste Blanche , Briquet Maryline , Mathis Stéphane 
Published: August 2014

AbstractThe presence of pulsations influences the local parameters at the surface of massive stars and thus it modifies the Zeeman magnetic signatures. Therefore it makes the characterisation of a magnetic field in pulsating stars more difficult and the characterisation of pulsations is thus required for the study of magnetic massive stars. Conversely, the presence of a magnetic field can inhibit differential rotation and mixing in massive stars and thus provides important constraints for seismic modelling based on pulsation studies. As a consequence, it is necessary to combine spectropolarimetric and seismic studies for all massive classical pulsators. Below we show examples of such combined studies and the interplay between physical processes.
Binary and multiple magnetic Ap/Bp stars
Authors: Rastegaev Denis , Balega Yuri , Dyachenko Vladimir , Maksimov Alexander , Malogolovets Evgenij 
Published: August 2014

AbstractWe present the results of speckle interferometric observations of 273 magnetic stars most of which are Ap/Bp type. All observations were made at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. We resolved 58 binary and 5 triple stars into individual components. Almost half of these stars were astrometrically resolved for the first time. The fraction of speckle interferometric binaries/multiples in the sample of stars with confirmed magnetic fields is 23%. We expect that the total fraction of binaries/multiples in the sample with account for spectroscopic short-period systems and wide common proper motion pairs can be twice higher. The detected speckle components have a prominent peak in the ρ distribution that corresponds to the closest resolved pairs. Full version of present paper is available in electronic form at http://arxiv.org/abs/1308.3168.
Wind channeling, magnetospheres, and spindown of magnetic massive stars
Authors: Owocki S. P. , ud-Doula A. , Townsend R. H. D. , Petit V. , Sundqvist J. O. , Cohen D. H. 
Published: August 2014

AbstractA subpopulation (~10%) of hot, luminous, massive stars have been revealed through spectropolarimetry to harbor strong (hundreds to tens of thousand Gauss), steady, large-scale (often significantly dipolar) magnetic fields. This review focuses on the role of such fields in channeling and trapping the radiatively driven wind of massive stars, including both in the strongly perturbed outflow from open field regions, and the wind-fed “magnetospheres” that develop from closed magnetic loops. For B-type stars with weak winds and moderately fast rotation, one finds “centrifugal magnetospheres”, in which rotational support allows magnetically trapped wind to accumulate to a large density, with quite distinctive observational signatures, e.g. in Balmer line emission. In contrast, more luminous O-type stars have generally been spun down by magnetic braking from angular momentum loss in their much stronger winds. The lack of centrifugal support means their closed loops form a “dynamical magnetosphere”, with trapped material falling back to the star on a dynamical timescale; nonetheless, the much stronger wind feeding leads to a circumstellar density that is still high enough to give substantial Balmer emission. Overall, this review describes MHD simulations and semi-analytic dynamical methods for modeling the magnetospheres, the magnetically channeled wind outflows, and the associated spin-down of these magnetic massive stars.
The Hertzsprung-gap giant 31 Comae in 2013: Magnetic field and activity indicators
Authors: Borisova Ana P. , Konstantinova-Antova Renada , Aurière Michel , Petit Pascal , Charbonnel Corinne 
Published: August 2014

AbstractWe have observed the giant star 31 Comae in April and May 2013 with the spectropolarimeter Narval at Pic du Midi Observatory, France. 31 Comae is a single, rapidly rotating giant with rotational period ~6.8 d and vsini ~ 67 km/s. We present measurements and discuss variability of the longitudinal magnetic field (Bl), spectral activity indicators Hα, CaII H&K, Ca II IR triplet and evolutionary status. Our future aim is to perform a Zeeman-Doppler imaging study for the star.