bluuebunny/crossref_metadata_2025 huggingface dataset:
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

We 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

Maser 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

The 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

For 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

The 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

Four 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

We 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

In 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

Many 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

More 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

We 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

We 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

Using 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

In 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.
A golden age for maser surveys
Authors: Breen Shari L.
Published: July 2018

Masers are becoming increasingly important probes of high-mass star formation, revealing details about the kinematics and physical conditions at the elusive, early stages of formation. Over the last decade significant investment has been made in a number of large-scale, sensitive maser surveys targeting transitions found in the vicinity of young, high-mass stars. Individually, these searches have led to valuable insights into maser populations, their associated star formation regions, and often revealed further details such as Galactic structure. In combination, they become even more powerful, especially when considered together with complementary multi-wavelength data. Another consequence of large maser surveys has been the identification of a number of especially interesting sources that have been the subject of subsequent detailed studies. I summarize the recent plethora of maser surveys, their results, and how they are contributing to our understanding of star formation. Ongoing searches will ensure a bright future of maser surveys in the decade to come.
Infrared variability, maser activity, and accretion of massive young stellar objects
Authors: Stecklum Bringfried , Garatti Alessio Caratti o , Hodapp Klaus , Linz Hendrik , Moscadelli Luca , Sanna Alberto
Published: July 2018

Methanol and water masers indicate young stellar objects. They often exhibit flares, and a fraction shows periodic activity. Several mechanisms might explain this behavior but the lack of concurrent infrared (IR) data complicates the identification of its cause. Recently, 6.7 GHz methanol maser flares were observed, triggered by accretion bursts of high-mass YSOs which confirmed the IR-pumping of these masers. This suggests that regular IR changes might lead to maser periodicity. Hence, we scrutinized space-based IR imaging of YSOs associated with periodic methanol masers. We succeeded to extract the IR light curve from NEOWISE data for the intermediate mass YSO G107.298+5.639. Thus, for the first time a relationship between the maser and IR variability could be established. While the IR light curve shows the same period of ~34.6 days as the masers, its shape is distinct from that of the maser flares. Possible reasons for the IR periodicity are discussed.
Hot and cold running water: understanding evolved star winds
Authors: Richards A. M. S. , Gray M. D. , Baudry A. , Humphreys E. M. L. , Etoka S. , Decin L. , Marti-Vidal I. , Sobolev A. M. , Vlemmings W.
Published: July 2018

Outstanding problems concerning mass-loss from evolved stars include initial wind acceleration and what determines the clumping scale. Reconstructing physical conditions from maser data has been highly uncertain due to the exponential amplification. ALMA and e-MERLIN now provide image cubes for five H2O maser transitions around VY CMa, at spatial resolutions comparable to the size of individual clouds or better, covering excitation states from 204 to 2360 K. We use the model of Gray et al. 2016, to constrain variations of number density and temperature on scales of a few au, an order of magnitude finer than is possible with thermal lines, comparable to individual cloud sizes or locally almost homogeneous regions. We compare results with the models of Decin et al. 2006 and Matsuura et al. 2014 for the circumstellar envelope of VY CMa; in later work this will be extended to other maser sources.
Class I Methanol Maser Emission in NGC 4945
Authors: McCarthy Tiege P. , Ellingsen Simon P. , Chen Xi , Breen Shari L. , Voronkov Maxim A. , Qiao Hai-hua
Published: July 2018

We have detected maser emission from the 36.2 GHz (4−1 → 30E) methanol transition towards NGC 4945. This emission has been observed in two separate epochs and is approximately five orders of magnitude more luminous than typical emission from this transition within our Galaxy. NGC 4945 is only the fourth extragalactic source observed hosting class I methanol maser emission. Extragalactic class I methanol masers do not appear to be simply highly-luminous variants of their galactic counterparts and instead appear to trace large-scale regions where low-velocity shocks are present in molecular gas.
Sub-mm observations of periodic methanol masers
Authors: van der Walt D. J. , Morgan J.-M. , Chibueze J. O. , Zhang Q.
Published: July 2018

We present the results of sub-millimetre observations on three periodic methanol maser sources. Our results indicate that there are geometric differences between some periodic methanol masers which have different variability profiles.
Pumping regimes of Class I methanol masers
Authors: Sobolev A. M. , Parfenov S. Yu.
Published: July 2018

In the current paper we describe results of an extensive and refined analysis which shows that the beaming leads to considerable changes in the model line ratios and brightness estimates. For example, beaming shifts the locus of the brightest masers to the lower values of the gas densities. Recent theoretical paper by Leurini et al. (2016) presented extensive consideration of the Class I methanol maser (MMI) pumping. Their study allowed to distinguish only 3 of 4 MMI pumping regimes found in Sobolev et al. (2005) and Sobolev et al. (2007) on the basis of analysis of observational data combined with theoretical considerations. The regime when the line from the J−2 − (J − 1)−1E series is the brightest was missing in Leurini et al. (2016) results. This may be explained by considering the fact that the authors did not take into account considerable beaming effects.
Strong magnetic field of the peculiar red supergiant VY Canis Majoris
Authors: Shinnaga Hiroko , Claussen Mark J. , Yamamoto Satoshi , Masumi Shimojo
Published: July 2018

We report on magnetic field measurements associated with the well-known extreme red supergiant (RSG), VY Canis Majoris (VY CMa). We measured both linear and circular polarization of the SiO v = 0, J = 1 − 0 transition using a sensitive radio interferometer. The measured magnetic field strengths are surprisingly high. A lower limit for the field strength is expected to be at least ~ 10 Gauss based on the high degree of linear polarization. Since the field strengths are very high, the magnetic field must be a key element in understanding the stellar evolution of VY CMa as well as the dynamical and chemical evolution of the complex circumstellar envelope of the star.
Radio continuum of galaxies with H2O megamaser disks
Authors: Kamali F. , Henkel C. , Brunthaler A. , Impellizzeri C. M. V. , Menten K. M. , Braatz J. A. , Greene J. E. , Reid M. J. , Condon J. J. , Lo K. Y. , Kuo C. Y. , Litzinger E. , Kadler M.
Published: July 2018

In our attempt to investigate the basic active galactic nucleus (AGN) paradigm requiring a centrally located supermassive black hole (SMBH), a close to Keplerian accretion disk and a jet perpendicular to its plane, we have searched for radio continuum in galaxies with H2O megamasers in their disks. We observed 18 such galaxies with the Very Large Baseline Array in C band (5 GHz, ~2 mas resolution) and we detected 5 galaxies at 8 σ or higher levels. For those sources for which the maser data is available, the positions of masers and those of the 5 GHz radio continuum sources coincide within the uncertainties, and the radio continuum is perpendicular to the maser disk’s orientation within the position angle uncertainties.
Class I methanol masers in low-mass star formation regions
Authors: Kalenskii S. , Kurtz S. , Hofner P. , Bergman P. , Walmsley C.M. , Golysheva P.
Published: July 2018

We present a review of the properties of Class I methanol masers detected in low-mass star forming regions (LMSFRs). These masers, henceforth called LMMIs, are associated with postshock gas in the lobes of chemically active outflows in LMSFRs NGC1333, NGC2023, HH25, and L1157. LMMIs share the main properties with powerful masers in regions of massive star formation and are a low-luminosity edge of the total Class I maser population. However, the exploration of just these objects may push forward the exploration of Class I masers, since many LMSFRs are located only 200–300 pc from the Sun, making it possible to study associated objects in detail. EVLA observations with a 0.2″ spatial resolution show that the maser images consist of unresolved or barely resolved spots with brightness temperatures up to 5 × 105 K. The results are “marginally” consistent with the turbulent model of maser emission.
VERA Single Dish Observations
Authors: Sunada Kazuyoshi , Nagayama Takumi , Yamauchi Aya , Hirota Tomoya , Shibata Katsunori M. , Honma Mareki
Published: July 2018

We will report the activities of the VERA single-dish observations. We are carrying out single-dish observations with two purposes. The first purpose is the monitoring of known H2O maser sources. At present, we are carrying out monitoring observations for 312 H2O maser sources at intervals of two months. The second purpose is the search for new water maser sources. We selected 901 target sources from the AKARI FIS Bright Source Catalogue. We found 61 new H2O maser sources.
Maser Astrometry and Galactic Structure Study with VLBI
Authors: Honma Mareki , Nagayama Takumi , Hirota Tomoya , Sakai Nobuyuki , Oyama Tomoaki , Yamauchi Aya , Ishikawa Toshiaki , Handa Toshihiro , Hirano Ken , Imai Hiroshi , Jike Takaaki , Kameya Osamu , Kono Yusuke , Kobayashi Hideyuki , Nakagawa Akiharu , Shibata Katsunori M. , Sakai Daisuke , Sunada Kazuyoshi , Sugiyama Koichiro , Sato Katsuhisa , Omodaka Toshihiro , Tamura Yoshiaki , Ueno Yuji
Published: July 2018

In this proceeding paper, we introduce the recent results of Galactic maser astrometry by mainly focusing on those obtained with Japanese VLBI array VERA. So far we have obtained parallaxes for 86 sources including preliminary results, and combination with the data obtained with VLBA/BeSSeL provides astrometric results for 159 sources. With these most updated results we conduct preliminary determinations of Galactic fundamental parameters, obtaining R0 = 8.16 ± 0.26 kpc and Θ0 = 237 ± 8 km/s. We also derive the rotation curve of the Milky Way Galaxy and confirm the previous results that the rotation curve is fairly flat between 5 kpc and 16 kpc, while a remarkable deviation is seen toward the Galactic center region. In addition to the results on the Galactic structure, we also present brief overviews on other science topics related to masers conducted with VERA, and also discuss the future prospect of the project.
Peculiarities of Maser Data Correlation / Postcorrelation in Radioastron Mission
Authors: Litovchenko I. D. , Likhachev S. F. , Kostenko V. I. , Girin I. A. , Ladygin V. A. , Shurov M. A. , Avdeev V. Yu. , Alakoz A. V.
Published: July 2018

We discuss specific aspects of space-ground VLBI (SVLBI) data processing of spectral line experiments (H2O & OH masers) in Radioastron project. In order to meet all technical requirements of the Radioastron mission a new software FX correlator (ASCFX) and the unique data archive which stores raw data from all VLBI stations for all experiments of the project were developed in Astro Space Center. Currently all maser observations conducted in Radioastron project were correlated using the ASCFX correlator. Positive detections on the space-ground baselines were found in 38 sessions out of 144 (detection rate of about 27%). Finally, we presented upper limits on the angular size of the most compact spots observed in two galactic H2O masers, W3OH(H2O) and OH043.8-0.1.
RadioAstron space-VLBI project: studies of masers in star forming regions of our Galaxy and megamasers in external galaxies
Authors: Sobolev A. M. , Shakhvorostova N. N. , Alakoz A. V. , Baan W. A.
Published: July 2018

Observations of the masers in the course of RadioAstron mission yielded detections of fringes for a number of sources in both water and hydroxyl maser transitions. Several sources display numerous ultra-compact details. This proves that implementation of the space VLBI technique for maser studies is possible technically and is not always prevented by the interstellar scattering, maser beaming and other effects related to formation, transfer, and detection of the cosmic maser emission. For the first time, cosmic water maser emission was detected with projected baselines exceeding Earth Diameter. It was detected in a number of star-forming regions in the Galaxy and two megamaser galaxies NGC 4258 and NGC 3079. RadioAstron observations provided the absolute record of the angular resolution in astronomy. Fringes from the NGC 4258 megamaser were detected on baseline exceeding 25 Earth Diameters. This means that the angular resolution sufficient to measure the parallax of the water maser source in the nearby galaxy LMC was directly achieved in the cosmic maser observations. Very compact features with angular sizes about 20\muas\, have been detected in star-forming regions of our Galaxy. Corresponding linear sizes are about 5-10 million kilometers. So, the major step from milli- to micro-arcsecond resolution in maser studies is achieved by the RadioAstron mission. The existence of the features with extremely small angular sizes is established. Further implementations of the space–VLBI maser instrument for studies of the nature of cosmic objects, studies of the interaction of extremely high radiation field with molecular material and studies of the matter on the line of sight are planned.
LBA high resolution observations of ground- and excited-state OH masers towards G351.417+0.645
Authors: Chanapote T. , Asanok K. , Dodson R. , Rioja M. , Green J. A. , Kramer B. Hutawarakorn
Published: July 2018

We present the results from the Australian Long Baseline Array (LBA) observations of the ground- and excited-state OH masers at high resolutions towards the massive star-forming region G351.417+0.645 in 2012. We obtain the most accurate spatial gradient of magnetic fields at ground state transitions and verify the reliability of magnetic field strengths measured from previous lower resolution observations. In comparison with previous LBA observations in 2001 at 6.0 GHz, we identified several matched Zeeman pairs. We found that the OH maser features have no significant change of magnetic field strengths and directions with small internal proper motions, implying quite stable physical conditions. Additionally, we found that 1665- and 6035-MHz OH maser features reveal the same trend of reversal of magnetic fields. Moreover, we also analyzed the physical conditions at different locations from the coincidence of different OH maser transitions based on current OH maser models.
Probing Early Phases of High Mass Stars with 6.7 GHz Methanol Masers
Authors: Paulson Sonu Tabitha , Pandian Jagadheep D.
Published: July 2018

Methanol masers at 6.7 GHz are the brightest of class II methanol masers and have been found exclusively towards massive star forming regions. These masers can thus be used as a unique tool to probe the early phases of massive star formation. We present here the SED studies of 284 methanol masers chosen from the MMB catalogue, which falls in the Hi-GAL range (|l| ≤ 60°, |b| ≤ 1°). The masers are studied using the ATLASGAL, MIPSGAL and Hi-GAL data at wavelengths ranging from 24−870 micrometers. A single grey body component fit was used to model the cold dust emission whereas the emission from the warm dust is modelled by a black body. The clump properties such as isothermal mass, FIR luminosity and MIR luminosity were obtained using the best fit parameters of the SED fits. We discuss the physical properties of the sources and explore the evolutionary stages of the sources having 6.7 GHz maser emission in the timeline of high mass star formation.
Extragalactic maser surveys
Authors: Henkel C. , Greene J.-E. , Kamali F.
Published: July 2018

Since the IAU (maser-)Symposium 287 in Stellenbosch/South Africa (Jan. 2012), great progress has been achieved in studying extragalactic maser sources. Sensitivity has reached a level allowing for dedicated maser surveys of extragalactic objects. These included, during the last years, water vapor (H2O), methanol (CH3OH), and formaldehyde (H2CO), while surveys related to hydroxyl (OH), cyanoacetylene (HC3N) and ammonia (NH3) may soon become (again) relevant. Overall, with the upgraded Very Large Array (VLA), the Atacama Large Millimeter/submillimeter Array (ALMA), FAST (Five hundred meter Aperture Synthesis Telescope) and the low frequency arrays APERTIF (APERture Tile in Focus), ASKAP (Australian Square Kilometer Array Pathfinder) and MeerKAT (Meer Karoo Array Telescope), extragalactic maser studies are expected to flourish during the upcoming years. The following article provides a brief sketch of past achievements, ongoing projects and future perspectives.
Rapid burst of 6.7 GHz methanol maser in the high mass star region G33.641-0.228
Authors: Bērziņš Kārlis , Shmeld Ivar , Aberfelds Artis
Published: July 2018

We report another 6.7 GHz methanol maser burst in the high mass star region G33.641-0.228. The flare is in its second component at vLSR = 59.6 km s−1 and was observed in August-September 2016 by VIRAC radio telescope RT-32 in Irbene, Latvia. Several bursts of the second spatial component of G33.641-0.228 have been reported previously by Fujisawa et al. The maximum peak flux density of the source was measured to reach 343 Jy that is 13 times increase from its ground level. Significant oscillations were discovered during the decay phase indicating a more complex burst mechanism that cannot be explained by a simple heating of the region.
Structure of the Milky Way: View from the Southern Hemisphere
Authors: Hyland Lucas J. , Ellingsen Simon P. , Reid Mark J.
Published: July 2018

The exclusive association of Class II methanol masers with high mass star formation regions and in turn spiral arms, makes them ideal tracers of spiral structure. The bright and compact nature of masers also makes them good sources for Very Long Baseline Interferometry, with their fluxes visible on some of the longest terrestrial baselines. The success of the BeSSeL (Bar and Spiral Structure Legacy) project has demonstrated the use of masers in large scale high–precision trigonometric parallax surveys. This survey was then able to precisely map the spiral arms visible from the Northern Hemisphere and recalculate the fundamental Milky Way parameters R0 and θ0. The majority of the Milky Way is visible from the Southern Hemisphere and at the present time the Australian LBA (Long Baseline Array) is the only Southern Hemisphere array capable of taking high–precision trigonometric parallax data. We present the progress–to–date of the Southern Hemisphere experiment. We will also unveil a new broadband Southern Hemisphere array, capable of much faster parallax turnaround and atmospheric calibration.
Correction: DNA damage and S phase-dependent E2F1 stabilization requires the cIAP1 E3-ubiquitin ligase and is associated with K63-poly-ubiquitination on lysine 161/164 residues
Authors: Glorian Valérie , Allègre Jennifer , Berthelet Jean , Dumetier Baptiste , Boutanquoi Pierre-Marie , Droin Nathalie , Kayaci Cémile , Cartier Jessy , Gemble Simon , Marcion Guillaume , Gonzalez Daniel , Boidot Romain , Garrido Carmen , Micheau Olivier , Solary Eric , Dubrez Laurence
Published: July 2018

Correction to:Cell Death & Disease8, e2816 (2017); https://doi.org/10.1038/cddis.2017.222; published online 25 May 2017.
Correction: Tenovin-6 impairs autophagy by inhibiting autophagic flux
Authors: Yuan Hongfeng , Tan Brandon , Gao Shou-Jiang
Published: July 2018

This Article was originally published under Nature Research’s License to Publish, but has now been made available under a CC BY 4.0 license. The PDF and HTML versions of the Article have been modified accordingly.
Correction: Deficiency of pigment epithelium-derived factor in nasopharyngeal carcinoma cells triggers the epithelial–mesenchymal transition and metastasis
Authors: Zhang Ting , Yin Ping , Zhang Zichen , Xu Banglao , Di Che  , Dai Zhiyu , Dong Chang , Jiang Ping , Hong Honghai , Yang Zhonghan , Zhou Ti , Shao Jianyong , Xu Zumin , Yang Xia , Gao Guoquan
Published: July 2018

The PDF and HTML versions of the article have been updated to include the Creative Commons Attribution 4.0 International License information.Correction to: Cell Death Dis.5, e1484 (2014); https://doi.org/10.1038/cddis.2014.408; published online 23 October 2014.
Comparisons of gut microbiota profiles in wild-type and gelatinase B/matrix metalloproteinase-9-deficient mice in acute DSS-induced colitis
Authors: de Bruyn Magali , Sabino João , Vandeputte Doris , Vermeire Séverine , Raes Jeroen , Opdenakker Ghislain
Published: July 2018

Gut microbiota help to educate the immune system and a number of involved immune cells were recently characterized. However, specific molecular determinants in these processes are not known, and, reciprocally, little information exists about single host determinants that alter the microbiota. Gelatinase B/matrix metalloproteinase-9 (MMP-9), an innate immune regulator and effector, has been suggested as such a host determinant. In this study, acute colitis was induced in co-housed MMP-9-/- mice (n = 10) and their wild-type (WT) littermates (n = 10) via oral administration of 3% dextran sodium sulfate (DSS) for 7 days followed by 2 days of regular drinking water. Control mice (10 WT and 10 MMP-9-/-) received normal drinking water. Fecal samples were collected at time of sacrifice and immediately frozen at −80 °C. Microbiota analysis was performed using 16S rRNA amplicon sequencing on Illumina MiSeq and taxonomic annotation was performed using the Ribosomal Database Project as reference. Statistical analysis correcting for multiple testing was done using R. No significant differences in clinical or histopathological parameters were found between both genotypes with DSS-induced colitis. Observed microbial richness at genus level and microbiota composition were not significantly influenced by host genotype. In contrast, weight loss, disease activity index, cage, and phenotype did significantly influence the intestinal microbiota composition. After multivariate analysis, cage and phenotype were identified as the sole drivers of microbiota composition variability. In conclusion, changes in fecal microbiota composition were not significantly altered in MMP-9-deficient mice compared to wild-type littermates, but instead were mainly driven by DSS-induced colonic inflammation.
Neuroepithelial control of mucosal inflammation in acute cystitis
Authors: Butler Daniel S. C. , Ambite Ines , Nagy Karoly , Cafaro Caterina , Ahmed Abdulla , Nadeem Aftab , Filenko Nina , Tran Thi Hien , Andersson Karl-Erik , Wullt Björn , Puthia Manoj , Svanborg Catharina
Published: July 2018

The nervous system is engaged by infection, indirectly through inflammatory cascades or directly, by bacterial attack on nerve cells. Here we identify a neuro-epithelial activation loop that participates in the control of mucosal inflammation and pain in acute cystitis. We show that infection activates Neurokinin-1 receptor (NK1R) and Substance P (SP) expression in nerve cells and bladder epithelial cellsin vitroandin vivoin the urinary bladder mucosa. Specific innate immune response genes regulated this mucosal response, and single gene deletions resulted either in protection (Tlr4−/−andIl1b−/−mice) or in accentuated bladder pathology (Asc−/−andNlrp3−/−mice), compared to controls. NK1R/SP expression was lower inTlr4−/−andIl1b−/−mice than in C56BL/6WT controls but inAsc−/−andNlrp3−/−mice, NK1R over-activation accompanied the exaggerated disease phenotype, due, in part to transcriptional de-repression ofTacr1. Pharmacologic NK1R inhibitors attenuated acute cystitis in susceptible mice, supporting a role in disease pathogenesis. Clinical relevance was suggested by elevated urine SP levels in patients with acute cystitis, compared to patients with asymptomatic bacteriuria identifying NK1R/SP as potential therapeutic targets. We propose that NK1R and SP influence the severity of acute cystitis through a neuro-epithelial activation loop that controls pain and mucosal inflammation.
Anaesthetic Effects of Eugenol on Grass Shrimp (Palaemonetes sinensis) of Different Sizes at Different Concentrations and Temperatures
Authors: Li Yingdong , She Qiuxin , Han Zhibin , Sun Na , Liu Xu , Li Xiaodong
Published: July 2018

Essential oil derivatives are widely used for anaesthetising aquatic animals. However, the effectiveness of anaesthesia often varies according to the anaesthetic agent, species, temperature, dosage, and interactions among these factors. This study evaluated the effects of eugenol on three sizes of the shrimp Palaemonetes sinensis at different concentrations and temperatures. Eugenol dose, water temperature, and shrimp size were found to significantly influence anaesthesia in P. sinensis. Induction time decreased linearly with increasing water temperature and eugenol concentration, while it increased with body weight. However, recovery times lengthened with increasing concentration and temperature, and shortened with lower body size. At 100 and 200 μL/L eugenol concentrations, the survival rates of medium and large shrimps were maintained at over 80% at all temperatures studied over 72 h recovery. However, the survival rates of small shrimps were below 60% at 24 °C and 28 °C over 5 days of recovery. These results suggest that eugenol is an effective and rapid anaesthetic for P. sinensis, but it might have disadvantages such as slow recovery and possible mortality in small shrimps and at higher temperatures and dosages.
Author Correction: The global view of mRNA-related ceRNA cross-talks across cardiovascular diseases
Authors: Song Chao , Zhang Jian , Qi Hanping , Feng Chenchen , Chen Yunping , Cao Yonggang , Ba Lina , Ai Bo , Wang Qiuyu , Huang Wei , Li Chunquan , Sun Hongli
Published: July 2018

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.
Uncaria tomentosa improves insulin sensitivity and inflammation in experimental NAFLD
Authors: Araujo Layanne C. C. , Feitosa Karla B. , Murata Gilson M. , Furigo Isadora C. , Teixeira Simone A. , Lucena Camila F. , Ribeiro Luciene M. , Muscará Marcelo N. , Costa Soraia K. P. , Donato José , Bordin Silvana , Curi Rui , Carvalho Carla R. O.
Published: July 2018

We investigated the effect of the crude herbal extract from Uncaria tomentosa (UT) on non-alcoholic fatty liver disease (NAFLD) in two models of obesity: high fat diet (HFD) and genetically obese (ob/ob) mice. Both obese mouse models were insulin resistant and exhibited an abundance of lipid droplets in the hepatocytes and inflammatory cell infiltration in the liver, while only the HFD group had collagen deposition in the perivascular space of the liver. UT treatment significantly reduced liver steatosis and inflammation in both obese mouse models. Furthermore, serine phosphorylation of IRS-1 was reduced by 25% in the HFD mice treated with UT. Overall, UT treated animals exhibited higher insulin sensitivity as compared to vehicle administration. In conclusion, Uncaria tomentosa extract improved glucose homeostasis and reverted NAFLD to a benign hepatic steatosis condition and these effects were associated with the attenuation of liver inflammation in obese mice.
Discrete, high-latitude foraging areas are important to energy budgets and population dynamics of migratory leatherback turtles
Authors: Wallace Bryan P. , Zolkewitz Michael , James Michael C.
Published: July 2018

Many broadly distributed migratory species exhibit fidelity to fine-scale areas that support vital life history requirements (e.g., resource acquisition, reproduction). Thus, such areas are critical for population dynamics and are of high conservation priority. Leatherback sea turtles are among the world’s most widely distributed species, and their breeding and feeding areas are typically separated by thousands of kilometres. In this study, we analysed turtle-borne video data on daytime feeding rates and energy acquisition in Nova Scotia, Canada, to quantify the importance of this discrete, seasonal foraging area for leatherback energy requirements. Based on daytime foraging only, we estimate that a single foraging season in Nova Scotia could support 59% of a non-breeding leatherback’s annual energy budget, and 29% of energetic requirements for a female on a typical 2-year reproductive cycle. However, maximum energy intake rates for leatherbacks are nearly four times lower than those of mammals and birds due the low energy content of leatherbacks’ gelatinous zooplankton prey. These results illustrate that high quality, local-scale foraging areas such as Nova Scotia are critically important to the stability and future growth of the leatherback population in the Northwest Atlantic Ocean. Thus, as with other migratory species, efforts to reduce threats and maintain habitat quality in such areas should be high conservation priorities.
A simple strategy for retargeting lentiviral vectors to desired cell types via a disulfide-bond-forming protein-peptide pair
Authors: Kasaraneni Nagarjun , Chamoun-Emanuelli Ana M. , Wright Gus A. , Chen Zhilei
Published: July 2018

Despite recent improvements in the engineering of viral envelope proteins, it remains a significant challenge to create lentiviral vectors that allow targeted transduction to specific cell populations of interest. In this study, we developed a simple ‘plug and play’ strategy to retarget lentiviral vectors to any desired cell types through in vitro covalent modification of the virions with specific cell-targeting proteins (CTPs). This strategy exploits a disulfide bond-forming protein-peptide pair PDZ1 and its pentapeptide ligand (ThrGluPheCysAla, TEFCA). PDZ1 was incorporated into an engineered Sindbis virus envelope protein (Sind-PDZ1) and displayed on lentiviral particles while the TEFCA pentapeptide ligand was genetically linked to the CTP. Her2/neu-binding designed ankyrin repeat proteins (DARPin) were used as our model CTPs. DARPin-functionalized unconcentrated lentiviral vectors harboring Sind-PDZ1 envelope protein (Sind-PDZ1-pp) exhibited >800-fold higher infectious titer in HER2+ cells than the unfunctionalized virions (8.5 × 106 vs. <104 IU/mL). Moreover, by virtue of the covalent disulfide bond interaction between PDZ1 and TEFCA, the association of the CTP with the virions is nonreversible under non-reducing conditions (e.g. serum), making these functionalized virions potentially stable in an in vivo setting.
Temporal analysis of Arabidopsis genes activated by Eucalyptus grandis NAC transcription factors associated with xylem fibre and vessel development
Authors: Laubscher M. , Brown K. , Tonfack L. B. , Myburg A. A. , Mizrachi E. , Hussey S. G.
Published: July 2018

Secondary cell wall (SCW) deposition in Arabidopsis is regulated among others by NAC transcription factors, where SND1 chiefly initiates xylem fibre differentiation while VND6 controls metaxylem vessel SCW development, especially programmed cell death and wall patterning. The translational relevance of Arabidopsis SCW regulation theory and the utility of characterized transcription factors as modular synthetic biology tools for improving commercial fibre crops is unclear. We investigated inter-lineage gene activation dynamics for potential fibre and vessel differentiation regulators from the widely grown hardwood Eucalyptus grandis (Myrtales). EgrNAC26, a VND6 homolog, and EgrNAC61, an SND1 homolog, were transiently expressed in Arabidopsis mesophyll protoplasts in parallel to determine early and late (i.e. 7 and 14 hours post-transfection) gene targets. Surprisingly, across the time series EgrNAC26 activated only a subset of SCW-related transcription factors and biosynthetic genes activated by EgrNAC61, specializing instead in targeting vessel-specific wall pit and programmed cell death markers. Promoters of EgrNAC26 and EgrNAC61 both induced reporter gene expression in vessels of young Arabidopsis plants, with EgrNAC61 also conferring xylem- and cork cambium-preferential expression in Populus. Our results demonstrate partial conservation, with notable exceptions, of SND1 and VND6 homologs in Eucalyptus and a first report of cork cambium expression for EgrNAC61.
Orbital Frontal Cortex Projections to Secondary Motor Cortex Mediate Exploitation of Learned Rules
Authors: Schreiner Drew C. , Gremel Christina M.
Published: July 2018

Animals face the dilemma between exploiting known opportunities and exploring new ones, a decision-making process supported by cortical circuits. While different types of learning may bias exploration, the circumstances and the degree to which bias occurs is unclear. We used an instrumental lever press task in mice to examine whether learned rules generalize to exploratory situations and the cortical circuits involved. We first trained mice to press one lever for food and subsequently assessed how that learning influenced pressing of a second novel lever. Using outcome devaluation procedures we found that novel lever exploration was not dependent on the food value associated with the trained lever. Further, changes in the temporal uncertainty of when a lever press would produce food did not affect exploration. Instead, accrued experience with the instrumental contingency was strongly predictive of test lever pressing with a positive correlation between experience and trained lever exploitation, but not novel lever exploration. Chemogenetic attenuation of orbital frontal cortex (OFC) projection into secondary motor cortex (M2) biased novel lever exploration, suggesting that experience increases OFC-M2 dependent exploitation of learned associations but leaves exploration constant. Our data suggests exploitation and exploration are parallel decision-making systems that do not necessarily compete.
Nitric oxide dependent signaling via cyclic GMP in dendritic cells regulates migration and T-cell polarization
Authors: Gnipp Stefanie , Mergia Evanthia , Puschkarow Michelle , Bufe Albrecht , Koesling Doris , Peters Marcus
Published: July 2018

Allergic airway inflammation is accompanied by excessive generation of nitric oxide (NO). Beside its detrimental activity due to the generation of reactive nitrogen species, NO was found to modulate immune responses by activating the NO-sensitive Guanylyl Cyclases (NO-GCs) thereby mediating the formation of the second messenger cyclic GMP (cGMP). To investigate the contribution of the key-enzyme NO-GC on the development of Th2 immunityin vivo, we sensitized knock-out (KO) mice of the major isoform NO-GC1 to the model allergen ovalbumin (OVA). The loss of NO-GC1 attenuates the Th2 response leading to a reduction of airway inflammation and IgE production. Further,in vitro-generated OVA-presenting DCs of the KO induce only a weak Th2 response in the WT recipient mice upon re-exposure to OVA.In vitro, these NO-GC1 KO BMDCs develop a Th1-polarizing phenotype and display increased cyclic AMP (cAMP) formation, which is known to induce Th1-bias. According to our hypothesis of a NO-GC1/cGMP-dependent regulation of cAMP-levels we further demonstrate activity of the cGMP-activated cAMP-degrading phosphodiesterase 2 in DCs. Herewith, we show that activity of NO-GC1 in DCs is important for the magnitude and bias of the Th response in allergic airway disease most likely by counteracting intracellular cAMP.