bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neotectonics of the Kharaulakh sector of the Laptev Shelf
Authors: Imaev V.S. , Imaeva L.P. , Smekalin O.P. , Chipizubov A.V. , Ovsyuchenko A.N. , Kolodeznikov I.I. 
Published: July 2018

Abstract
Seismotectonic deformation and crustal stress pattern have been studied comprehensively in major seismogenic structures of the Kharaulakh sector of the Verkhoyansk fold system and adjacent parts of the Chersky seismotectonic zone. The study focuses on neotectonic structures, deep structure, and systems of active faults, as well as tectonic stress fields inferred by tectonophysical analysis of Late Cenozoic faults and folds. The results, along with geological and geophysical data, reveal main strain directions and structural patterns of crustal stress and strain in the Arctic segment of the Eurasia–North America plate boundary. The area is a junction of mid-ocean and continental structures evolving in a mixed setting of extension, compression, and their various combinations. The rotation pole of the two plates is presumably located near Buor-Khaya Bay. In this case, extension is expected to act currently upon the neotectonic structures north of the bay and compression to control those in the south and southeast. This inference is consistent with the identified zoning of stress and strain in the Kharaulakh sector.
More Rapid 14C Excursions in the Tree-Ring Record: A Record of Different Kind of Solar Activity at About 800 BC?
Authors: Jull A J Timothy , Panyushkina Irina , Miyake Fusa , Masuda Kimiaki , Nakamura Toshio , Mitsutani Takumi , Lange Todd E , Cruz Richard J , Baisan Chris , Janovics Robert , Varga Tamas , Molnár Mihály 
Published: July 2018

ABSTRACTTwo radiocarbon (14C) excursions are caused by an increase of incoming cosmic rays on a short time scale found in the Late Holocene (AD 774–775 and AD 993–994), which are widely explained as due to extreme solar proton events (SPE). In addition, a larger event has also been reported at 5480 BC (Miyake et al. 2017a), which is attributed to a special mode of a grand solar minimum, as well as another at 660 BC (Park et al. 2017). Clearly, other events must exist, but could have different causes. In order to detect more such possible events, we have identified periods when the 14C increase rate is rapid and large in the international radiocarbon calibration (IntCal) data (Reimer et al. 2013). In this paper, we follow on from previous studies and identify a possible excursion starting at 814–813 BC, which may be connected to the beginning of a grand solar minimum associated with the beginning of the Hallstatt period, which is characterized by relatively constant 14C ages in the period from 800–400 BC. We compare results of annual 14C measurements from tree rings of sequoia (California) and cedar (Japan), and compare these results to other identified excursions, as well as geomagnetic data. We note that the structure of the increase from 813 BC is similar to the increase at 5480 BC, suggesting a related origin. We also assess whether there are different kinds of events that may be observed and may be consistent with different types of solar phenomena, or other explanations.
Diaphanocephalus galeatus (Nematoda: Diaphanocephalidae), a poorly known parasite of lizards: redescription, first genetic characterization and a revision of its congeners from Brazil
Authors: Pereira F.B. , Ferreira V.L. , Tomas W.M. , Elisei C. , Paiva F. , Tavares L.E.R. 
Published: July 2018

AbstractDiaphanocephalus galeatus collected from the small intestine of the lizard Dracaena paraguayensis in the Pantanal wetlands, State of Mato Grosso do Sul, Brazil, is redescribed. Genetic characterization and observations using scanning electron microscopy (SEM) were performed for the first time. The vouchers of D. galeatus and the type specimens of its congeners, deposited in the Coleção Helmintológica do Instituto Oswaldo Cruz (CHIOC), were consulted. Light and SEM observations revealed several undescribed features of D. galeatus, i.e. structure of the cephalic end and of the buccal capsule, position and morphology of deirids, presence of phasmids in females and presence of unpaired papilla on the membranous projection that covers the genital cone in males. After observation of the specimens deposited in the helminthological collection, D. jacuruxi is considered a synonym of D. galeatus, and D. diesingi, despite its incomplete description, is tentatively retained as valid due to the poor condition of the type material. The results also indicated low host specificity of D. galeatus, contradicting previous assertions. Genetic comparisons using patristic distances and phylogenetic trees generated from sequences of the 28S rRNA nuclear gene indicated that D. galeatus is closer to the taxa within Ancylostomatoidea and Strongyloidea than any lineage of Metastrongyloidea or Trichostrongyloidea. However, most of the nodal supports were low. Based on the genetic and morphological characterization, the validity of D. galeatus was confirmed. These data may serve for further comparative approaches for different populations of the parasite, from different hosts in different geographical areas, mitigating taxonomic confusions.
Endoscopic cricoid split in a tertiary referral paediatric centre
Authors: Carr S , Dritsoula A , Thevasagayam R 
Published: July 2018

AbstractBackgroundAnterior cricoid split is performed for grade 2 and 3 subglottic stenosis, which can be a cause of extubation failure. It can be performed endoscopically or as an open procedure. This paper describes a case series of endoscopic cricoid split procedures performed using a bespoke sickle knife.MethodNine patients (six pre-term infants) underwent endoscopic cricoid split in a tertiary referral paediatric unit between August 2012 and March 2015.ResultsSix patients (67 per cent; four pre-term and two term infants) were on oxygen pre-operatively. Mean age at operation was 30 weeks (range, 11–104 weeks). Mean number of days’ intubation was 5.6 days (range, 4–9 days). All five patients intubated pre-operatively were extubated. Seven patients required repeat dilatations. One patient required tracheostomy.ConclusionThe extubation rates for endoscopic cricoid split are comparable to the open procedure. It is a safe and efficient method for managing subglottic stenosis, whether acquired or congenital. The main advantage is the shorter operative time, in addition to the avoidance of an external scar and drain.
Redistributing under fiscal constraint: partisanship, debt, inequality and labour market regulation
Authors: Aaskoven Lasse 
Published: July 2018

AbstractLabour market regulation varies significantly, both within and between developed democracies. While there has been extensive research and debate in economics on the consequences of labour market regulation, the political causes for levels and changes in labour market regulation have received less scholarly attention. This article investigates a political economy explanation for differences in labour market regulation building on a theoretical argument that labour regulation can be used as a nonfiscal redistribution tool. Consequently, partisanship, the demand for redistribution and government budget constraint jointly determine whether labour market regulation will increase or decrease. Consistent with this argument, panel analyses from 33 Organisation for Economic Co-Operation and Development countries reveal that labour market regulation increases under left-wing governments that face increased market inequality and high government debt.
The political theorist, Fujita Shōzō: between his sense of hope (kibō) and his sense of despair (zetsubō)
Authors: Sakurai Takamichi 
Published: July 2018

AbstractIn this article, I describe an important aspect of the intellectual tradition of Japanese political theory while focusing on the Japanese scholar Fujita Shōzō’s political and scholarly activities. Not surprisingly, he has been chiefly considered a thinker or a historian of ideas, due to his being a pupil of Japan's brightest political scientist, Maruyama Masao. It must be stressed, however, that his scholarly works do not confine his academic scope to their ingredients; they are composed of theoretical requisites for the disciplinary activity of political theory, as can be seen particularly in his early contributions. He requires his theory to constitute integral aspects of practice, experience and perspective on the basis of his political concerns and practices in terms of detachment realism. From this perspective, I explore how Fujita changed his primary purpose from criticising Japan's ‘Tennō system’ (Tennōsei) to criticising its ‘high-speed growth’ (kōdo seichō) by highlighting the psychological transformation of his self-critical and self-reflective political thinking and acting according to his optimistic state of ‘hope’ (kibō) and his pessimistic state of ‘despair’ (zetsubō), especially in terms of his early work.
Strategic choices of bilateral and multilateral preferential trade agreements: empirical analysis
Authors: Yamamoto Rosenbaum Chika 
Published: July 2018

AbstractThe rapid proliferation of preferential trade agreements (PTAs) has prompted numerous studies on why states seek PTAs. However, very little research examines why states vary in choosing different forms of PTAs, while states’ decisions to enter bilateral or multilateral PTA affect the global, regional, and national political economies. This paper thus finds global patterns regarding which pairs of states are more likely to enter bilateral or multilateral PTAs. Based on a wide range of existing research, the paper begins with hypothesizing different effects of economic and political factors that give rise to these PTAs during the last two decades. The empirical analysis then tests these hypotheses. The result shows stark differences in pairs of states joining the two types of PTAs. Bilateral PTAs are more likely to develop between democratic states with a large market size and the World Trade Organization (WTO) membership. Multilateral PTAs tend to form between less democratic states with greater political affinity.
Interferometry of class I methanol masers, statistics and the distance scale
Authors: Voronkov Maxim A. , Breen Shari L. , Ellingsen Simon P. , Jordan Christopher H. 
Published: July 2018

AbstractThe Australia Telescope Compact Array (ATCA) participated in a number of survey programs to search for and image common class I methanol masers (at 36 and 44 GHz) with high angular resolution. In this paper, we discuss spatial and velocity distributions revealed by these surveys. In particular, the number of maser regions is found to fall off exponentially with the linear distance from the associated young stellar object traced by the 6.7-GHz maser, and the scale of this distribution is 263±15 milliparsec. Although this relationship still needs to be understood in the context of the broader field, it can be utilised to estimate the distance using methanol masers only. This new technique has been analysed to understand its limitations and future potential. It turned out, it can be very successful to resolve the ambiguity in kinematic distances, but, in the current form, is much less accurate (than the kinematic method) if used on its own.
The Extensive Database of Astrophysical Maser Sources (eDAMS): the First Release on Circumstellar Maser Sources
Authors: Nakashima J. , Engels D. , Hsia C.-H. , Imai H. , Ladeyschikov D. A. , Sobolev A. M. , Yung B. H. K. , Zhang Y. 
Published: July 2018

AbstractWe introduce the newly developed database of circumstellar maser sources. Until now, the compilations comprehensively including the three major maser species in evolved stars (i.e., SiO, H2O, OH) has been practically limited only to the Benson’s catalog (Benson et al. 1990), which was published more than a quarter of a century ago. For OH masers alone, there exists the University of Hamburg (UH) database, but there is no updated compilation work for H2O and SiO masers. In order to utilize the information of masers in actual studies, it is highly desirable to have a database containing all the three masers. We are currently constructing a database covering SiO, H2O and OH masers. This database consists of a web-service, which accesses compiled maser observations in available archives and combines them with the data we newly collected and IR databases. The archives currently used are the OH maser archive from Engels & Bunzel (2015), and H2O and SiO archives, which are currently under construction. So far, the information of about 27,000 observations (about 10,000 objects) has been implemented. We also have a plan to extend the database by including higher transitions and other types of objects, such as young stellar objects, in future. In this paper, we briefly summarize, (1) outline of the data collected, and (2) future development plans of the eDAMS system. The URL of the database is as follows: http://maserdb.ins.urfu.ru/
Structure and Kinematics of the Milky Way
Authors: Reid Mark J. 
Published: July 2018

AbstractMaser astrometry is now providing parallaxes with accuracies of ±10 micro-arcseconds, which corresponds to 10% accuracy at a distance of 10 kpc! The VLBA BeSSeL Survey and the Japanese VERA project have measured ≈200 parallaxes for masers associated with young, high-mass stars. Since these stars are found in spiral arms, we now are directly mapping the spiral structure of the Milky Way. Combining parallaxes, proper motions, and Doppler velocities, we have complete 6-dimensional phase-space information. Modeling these data yields the distance to the Galactic Center, the rotation speed of the Galaxy at the Sun, and the nature of the rotation curve.
Long term 6.7 GHz methanol maser monitoring program
Authors: Aberfelds Artis , Shmeld Ivar , Berzins Karlis 
Published: July 2018

AbstractThe first long-term maser (mainly methanol) monitoring program is under way with the radio telescopes of Ventspils International Radio Astronomy Center. The first activity of this program was to develop an observations methodology and data registration and reduction software for the Ventspils telescopes. The developed routines are to be used for maser variability monitoring, investigating short bursts of intensity and a search for new, previously unknown, maser sources. Currently the program consists of 41 methanol masers observed at 6.7 GHz, while new ones are periodically added. The maser sources are observed at 3 – 5 day intervals. It was found that most the sources display a significant level of variability with time, ranging from a few days, up to several months and, perhaps, years. In addition to non-varying masers, several types of maser variability behavior were observed, including: monotonic increases or decreases, un-periodical, quasi-periodic and periodic variations.
Variability of water masers in evolved stars on timescales of decades
Authors: Brand Jan , Engels Dieter , Winnberg Anders 
Published: July 2018

AbstractFor several decades (1987-2015) we have been carrying out observations of water masers in the circumstellar envelopes (CSE’s) of Mira variables, Red Supergiants (RSG’s) and Semi-Regular Variables (SRV’s) with the Medicina 32-m and Effelsberg 100-m antennas. The single-dish monitoring observations provide evidence for strong H2O maser profile variations, which likely are connected to structural changes in the maser shells. Such variations include strong flares in intensity lasting several (tens of) months and systemic velocity gradients of maser components developing over years, as well as other secular variations which are superimposed on periodic variations following the stellar light variations.When complemented with interferometric observations, it is possible to derive the 3-D distribution of the maser spots, and their lifetime, as we have done for RX Boo (Winnberget al.2008) and U Her (Winnberget al.2011; Brandet al. in prep.).
Revealing the kinematics and origin of ionized winds using RRL masers
Authors: Báez-Rubio Alejandro 
Published: July 2018

AbstractThe detection of hydrogen radio-recombination maser lines (RRLs) toward MWC349A in the year 1989 opened the chance to place constraints on the kinematics of an ionized circumstellar disk around a massive star. Since then, a significant number of observations have allowed improving our understanding of this source to the point that we have established that its ionized wind launching occurs at a distance of ~24 au as claimed by disk wind models. On the other hand, this field of study has undergone considerable development over the last six years with the detection of new RRL maser sources. Here, we present a brief summary of all these recent advances and the promising future prospects.
Current stage of the ATCA follow-up for SPLASH
Authors: Qiao Hai-Hua , Walsh Andrew J. , Shen Zhi-Qiang 
Published: July 2018

AbstractFour ground-state OH transitions were detected in emission, absorption and maser emission in the Southern Parkes Large-Area Survey in Hydroxyl (SPLASH). We re-observed these OH masers with the Australia Telescope Compact Array to obtain positions with high accuracy (~1 arcsec). According to the positions, we categorised these OH masers into different classes, i.e. star formation, evolved stars, supernova remnants and unknown origin. We found one interesting OH maser source (G336.644-0.695) in the pilot region, which has been studied in detail in Qiaoet al.(2016a). In this paper, we present the current stage of the ATCA follow-up for SPLASH and discuss the potential future researches derived from the ATCA data.
A survey for OH masers in H2O maser galaxies with the Effelsberg and Green Bank radio telescopes
Authors: Ladu Elisabetta , Tarchi Andrea , Castangia Paola , Surcis Gabriele , Henkel Christian 
Published: July 2018

AbstractWe present a search for OH maser emission in galaxies hosting H2O masers with the 100-m Effelsberg radio telescope and the Green Bank Telescope (GBT). This survey is aimed at investigating the apparent rarity and/or possible mutual exclusion of megamaser emission from OH and H2O in the same galaxy. Our study establishes new and better upper limits on the OH maser luminosity. Our work duplicates the number of H2O masers searched for OH emission. No new maser detections have been found. OH absorption, both in the 1667 and 1665 MHz transitions, is instead detected in two galaxies of the sample, IC342 and NGG5793.
A next-generation Very Large Array
Authors: Murphy Eric J. 
Published: July 2018

AbstractIn this proceeding, we summarize the key science goals and reference design for a next-generation Very Large Array (ngVLA) that is envisaged to operate in the 2030s. The ngVLA is an interferometric array with more than 10 times the sensitivity and spatial resolution of the current VLA and ALMA, that will operate at frequencies spanning ~1.2 – 116 GHz, thus lending itself to be highly complementary to ALMA and the SKA1. As such, the ngVLA will tackle a broad range of outstanding questions in modern astronomy by simultaneously delivering the capability to: unveil the formation of Solar System analogues; probe the initial conditions for planetary systems and life with astrochemistry; characterize the assembly, structure, and evolution of galaxies from the first billion years to the present; use pulsars in the Galactic center as fundamental tests of gravity; and understand the formation and evolution of stellar and supermassive blackholes in the era of multi-messenger astronomy.
AGN accretion disk physics using H2O megamasers
Authors: Pesce Dominic , Braatz James , Condon James , Gao Feng , Henkel Christian , Impellizzeri Violette , Litzinger Eugenia , Lo K. Y. , Reid Mark 
Published: July 2018

AbstractMany accretion disks surrounding supermassive black holes in nearby AGN are observed to host 22 GHz water maser activity. We have analyzed single-dish 22 GHz spectra taken with the GBT to identify 32 such “Keplerian disk systems,” which we used to investigate maser excitation and explore the possibility of disk reverberation. Our results do not support a spiral shock model for population inversion in these disks, and we find that any reverberating signal propagating radially outwards from the AGN must constitute <10% of the total observed maser variability. Additionally, we have used ALMA to begin exploring the variety of sub-mm water megamasers that are also predicted, and in the case of the 321 GHz transition found, to be present in these accretion disks. By observing multiple masing transitions within a single system, we can better constrain the physical conditions (e.g., gas temperature and density) in the accretion disk.
Molecular clouds in the Extreme Outer Galaxy
Authors: Sun Yan , Xu Ye , Yang Ji , Su Yang , Zhang Shao-Bo , Chen Xue-Peng , Jiang Zhi-Bo , Zhou Xin 
Published: July 2018

AbstractMore than 200 molecular clouds were newly found distributed beyond the Outer arm in the extreme outer Galaxy (EOG) region by MWISP. Those MCs roughly following the HI′s distribution well delineate the outermost spiral structure (the Outer Scutum-Centaurus arm) and warp of our Galaxy. Besides, those MCs show different σv-Radius relation and exhibit higher value of αvir than MCs in the inner Galaxy.
Monitoring and search for periodic methanol masers
Authors: Olech M. , Szymczak M. , Wolak P. , Bartkiewicz A. 
Published: July 2018

AbstractWe summarize a long-term monitoring of 11 periodic 6.7 GHz methanol masers and a search for new periodic sources. Observations were carried out with the Torun 32 m telescope. Periods of observed sources range from 29 to 658 days and the data consist of more than 10 observed cycles for most of the masers. Inspection of archival data resulted in identification of 3 new periodic sources while 2 new periodic objects were found in observations started in 2014.
Magnetic fields and radio emission processes in maser-emitting planetary nebulae
Authors: Uscanga L. , Gómez J. F. , Green J. A. , Suárez O. , Qiao H.-H. , Walsh A. J. , Miranda L. F. , Trinidad M. A. , Anglada G. , Boumis P. 
Published: July 2018

AbstractWe present polarimetric observations of the 4 ground-state transitions of OH, toward a sample of maser-emitting planetary nebulae (PNe) using the Australia Telescope Compact Array. This sample includes confirmed OH-emitting PNe, confirmed and candidate H2O-maser-emitting PNe. Polarimetric observations provide information related to the magnetic field of these sources. Maser-emitting PNe are very young PNe and magnetic fields are a key ingredient in the early evolution and shaping process of PNe. Our preliminary results suggest that magnetic field strengths may change very rapidly in young PNe.
Simultaneity and Flux Bias between 43 and 86 GHz SiO Masers
Authors: Stroh Michael C. , Pihlström Ylva M. , Sjouwerman Lorant O. 
Published: July 2018

AbstractUsing quasi-simultaneous observations of 86 stars with known SiO maser emission, we searched for systematic differences between the strengths of the 43 and 86 GHz v=1 maser lines. Although for individual stars there is wide scatter between the line strengths spanning nearly an order of magnitude, there is no evidence of a systematic difference between these line strengths for the entire sample.
H2O maser observation using the 26-meter Nanshan Radio Telescope of the XAO
Authors: He Yu-Xin , Esimbek Jarken , Zhou Jian-Jun , Wu Gang , Tang Xin-Di , Ji Wei-Guang , Yuan Ye , Li Da-Lei 
Published: July 2018

AbstractIn the past few years, we have performed a 22 GHz H2O maser survey towards hundreds of BGPS sources using the 25-meter Nanshan Radio Telescope (NSRT) of the Xinjiang Astronomical Observatory, and detected more than one hundred masers. Our aim is to study star formation activities associated with these sources, as well as search for any correlations that may exist between 22 GHz H2O masers and the evolutionary stage of high-mass star formation regions. The NSRT has been upgraded and have now an effective diameter of 26 meter. Besides, cryogenically cooled dual-beam receiver systems covering seven millimeter-wave observing bands have been installed on the NSRT. For the next step of maser observation, we will continue to do H2O and SiO masers survey of massive dust clumps and monitor some maser sources.