bluuebunny/crossref_metadata_2025_split huggingface dataset:
Attendance of adult males at maternity roosts of big brown bats (Eptesicus fuscus)
Authors: O’Shea Thomas J , Stanley Thomas R , Neubaum Daniel J , Neubaum Melissa A , Pearce Roger D , Bowen Richard A 
Published: October 2020

AbstractAdult male big brown bats (Eptesicus fuscus) sometimes occur within maternity roosts. We investigated male attendance at big brown bat maternity roosts in a Colorado study area that shows a pattern of sexual segregation by elevation. We tested multiple predictions of three nonmutually exclusive hypotheses to explain male attendance patterns: 1) sex-specific differences in energetic strategies of males and females are maintained at the lower elevation; 2) natal philopatry of inexperienced young males accounts for most attendants; 3) males gain a reproductive advantage for late summer mating at maternity roosts. We tested predictions based on captures of bats at emergence, automated monitoring of annual, seasonal, and daily roost attendance by known-age bats tagged with passive integrated transponders, and anatomical evidence for mating. Findings were most consistent with the first two hypotheses. Adult males accounted for just 3.1% of 8,192 captures of bats at 285 evening emergences from 46 roosts during 2001–2005. Daily attendance rates of males during each active season (0.10 detections/day at age 1 year and 0.20 detections/day at ≥ 2 years old) were lower than in females (0.34 at age 1 year and 0.45 at ≥ 2 years old). Only 92 of 299 males tagged as volant juveniles were detected as adults at five maternity roosts monitored 2002–2005, far fewer than female returns in every age category. We detected known-age adult males almost exclusively at their natal roosts and most males that returned (91 of 92) in years after tagging as juveniles were first detected as 1-year-olds; 20 of 21 individuals that returned at 2–4 years of age were previously detected as 1-year-olds. One-year-old males were re-encountered at annual rates 5–16 times higher than 2- to 4-year-old males, and 1-year-old males and females had lower daily attendance rates than older bats. The male reproductive advantage hypothesis was not well supported. None of 80 females examined in late summer had evidence of insemination, and not all males showed distended scrota. Daily attendance rates of tagged adult males (n = 155) and females (n = 788) were lowest during late summer, suggesting that little reproductive advantage was accrued by males utilizing maternity roosts. Attendance of male big brown bats at maternity roosts at our study area is consistent with the sex-specific energetic strategies and natal philopatry hypotheses, and mating probably occurs at higher elevation autumn roosts and hibernacula.
Phase-shifting electron holography for accurate measurement of potential distributions in organic and inorganic semiconductors
Authors: Yamamoto Kazuo , Anada Satoshi , Sato Takeshi , Yoshimoto Noriyuki , Hirayama Tsukasa 
Published: October 2020

Abstract
Phase-shifting electron holography (PS-EH) is an interference transmission electron microscopy technique that accurately visualizes potential distributions in functional materials, such as semiconductors. In this paper, we briefly introduce the features of the PS-EH that overcome some of the issues facing the conventional EH based on Fourier transformation. Then, we present a high-precision PS-EH technique with multiple electron biprisms and a sample preparation technique using a cryo-focused-ion-beam, which are important techniques for the accurate phase measurement of semiconductors. We present several applications of PS-EH to demonstrate the potential in organic and inorganic semiconductors and then discuss the differences by comparing them with previous reports on the conventional EH. We show that in situ biasing PS-EH was able to observe not only electric potential distribution but also electric field and charge density at a GaAs p–n junction and clarify how local band structures, depletion layer widths and space charges changed depending on the biasing conditions. Moreover, the PS-EH clearly visualized the local potential distributions of two-dimensional electron gas layers formed at AlGaN/GaN interfaces with different Al compositions. We also report the results of our PS-EH application for organic electroluminescence multilayers and point out the significant potential changes in the layers. The proposed PS-EH enables more precise phase measurement compared to the conventional EH, and our findings introduced in this paper will contribute to the future research and development of high-performance semiconductor materials and devices.
Nitric oxide signalling in plant nanobiology: current status and perspectives
Authors: Kolbert Zsuzsanna , Szőllősi Réka , Feigl Gábor , Kónya Zoltán , Rónavári Andrea 
Published: October 2020

AbstractPlant nanobiology as a novel research field provides a scientific basis for the agricultural use of nanoparticles (NPs). Plants respond to the presence of nanomaterials by synthesizing signal molecules, such as the multifunctional gaseous nitric oxide (NO). Several reports have described the effects of different nanomaterials (primarily chitosan NPs, metal oxide NPs, and carbon nanotubes) on endogenous NO synthesis and signalling in different plant species. Other works have demonstrated the ameliorating effect of exogenous NO donor (primarily sodium nitroprusside) treatments on NP-induced stress. NO-releasing NPs are preferred alternatives to chemical NO donors, and evaluating their effects on plants has recently begun. Previous studies clearly indicate that endogenous NO production in the presence of nanomaterials or NO levels increased by exogenous treatments (NO-releasing NPs or chemical NO donors) exerts growth-promoting and stress-ameliorating effects in plants. Furthermore, an NP-based nanosensor for NO detection in plants has been developed, providing a new and excellent perspective for basic research and also for the evaluation of plants’ health status in agriculture.
Case Series of Arterial Gas Embolism Incidents in U.S. Navy Pressurized Submarine Escape Training From 2018 to 2019
Authors: Edgar Mia , Franco Michael A , Dainer Hugh M 
Published: October 2020

ABSTRACTThe goal of Pressurized Submarine Escape Training (PSET) is to prepare future submariners for the physical and mental challenges of escaping a disabled submarine and promote proper handling of the Beaufort Ltd Mk 11 Submarine Escape and Immersion Equipment suit. Training participants are only permitted to enter PSET after strict health screening protocols have been met to optimize trainees’ safety. Before PSET, trainees are given detailed, one-on-one instruction on proper ascent mechanics by specially trained Navy Dive instructors.Since the reinstatement of PSET by the U.S. Navy, four incidents of arterial gas embolism (AGE) have occurred in submarine trainees with a 10-year period (2009-2019). Of these four incidents, three were observed within a couple months of each other from 2018 to 2019. A comprehensive review of AGE history, epidemiology, dive physiology, pathophysiology, and management was completed. Prompted by the recent incidents relative to the low reported incidence rate of AGE in historical PSET training, reported potential risk factors were compared with better understand potential etiologies of AGE in already medically screened individuals. Risks and benefits of PSET were listed, compared, and analyzed. The relative safety and cost effectiveness of this rigorous form of training was reconfirmed.
Evidence of vertical abundance stratification in the SB1 star HD 161660: a new HgMn
Authors: Catanzaro G , Giarrusso M , Munari M , Leone F 
Published: October 2020

ABSTRACT
In this paper, we present a detailed spectroscopic study of the SB1 system HD 161660. New spectroscopic observations have been obtained by us with Catania Astrophysical Observatory Spectropolarimeter (CAOS@OAC). Combining these observations with archive data from HARPS@3.6ESO, we derived atmospheric parameters as temperature and gravity (from the fit of Balmer lines), microturbulence and rotational velocity (from metal lines), and chemical composition. We found underabundances of helium, carbon, magnesium, sulphur and chromium, overabundances of neon, phosphorus, argon, manganese, xenon, and mercury. All other elements have solar composition. In particular, mercury abundance is derived taking into account an isotopic mixture different from the terrestrial one (essentially pure 202Hg). Considering this chemical pattern, we definitively confirm HD 161660 is an HgMn star. Further, variability of equivalent widths points out a non-homogeneous distribution of helium and magnesium over stellar surface. As to iron and phosphorus, we found a non-constant abundance with the optical depth, a result currently considered an evidence of vertical stratification. Finally, we improved the fundamental parameters characterizing the HD 161660 orbit.
Eccentric tidal disruption event discs around supermassive black holes: dynamics and thermal emission
Authors: Zanazzi J J , Ogilvie Gordon I 
Published: October 2020

ABSTRACTAfter the tidal disruption event (TDE) of a star around a supermassive black hole (SMBH), if the stellar debris stream rapidly circularizes and forms a compact disc, the TDE emission is expected to peak in the soft X-ray or far ultraviolet (UV). The fact that many TDE candidates are observed to peak in the near UV and optical has challenged conventional TDE emission models. By idealizing a disc as a nested sequence of elliptical orbits that communicate adiabatically via pressure forces, and are heated by energy dissipated during the circularization of the nearly parabolic debris streams, we investigate the dynamics and thermal emission of highly eccentric TDE discs, including the effect of general-relativistic apsidal precession from the SMBH. We calculate the properties of uniformly precessing, apsidally aligned, and highly eccentric TDE discs, and find highly eccentric disc solutions exist for realistic TDE properties (SMBH and stellar mass, periapsis distance, etc.). Taking into account compressional heating (cooling) near periapsis (apoapsis), we find our idealized eccentric disc model can produce emission consistent with the X-ray and UV/optical luminosities of many optically bright TDE candidates. Our work attempts to quantify the thermal emission expected from the shock-heating model for TDE emission, and finds stream–stream collisions are a promising way to power optically bright TDEs.
An updated detailed characterization of planes of satellites in the MW and M31
Authors: Santos-Santos Isabel M , Domínguez-Tenreiro Rosa , Pawlowski Marcel S 
Published: October 2020

ABSTRACT
We present a detailed characterization of planes of satellite galaxies in the Milky Way (MW) and M31. For a positional analysis, we introduce an extension to the ‘4-galaxy-normal density plot’ method from Pawlowski, Kroupa & Jerjen. It finds the normal directions to the predominant planar configurations of satellites of a system, yielding for each a collection of planes of increasing member satellites. This allows to quantify the quality of planes in terms of population (Nsat) and spatial flattening (c/a). We apply this method to the latest data for confirmed MW and M31 satellite samples, with 46 and 34 satellites, respectively. New MW satellites form part of planes previously identified from a smaller sample of Nsat= 27: we identify a new plane with Nsat = 39 as thin as the VPOS-3 (c/a ∼ 0.2), and with roughly the same normal direction; so far the most populated plane that thin reported in the Local Group. We introduce a new method to determine, using kinematic data, the axis of maximum co-orbitation of MW satellites. Interestingly, this axis approximately coincides with the normal to the former plane: $\ge 45\pm 5{{\ \rm per\ cent}}$ of satellites co-orbit. In M31 we discover a plane with Nsat = 18 and c/a ∼ 0.15, i.e. quality comparable to the GPoA, and perpendicular to it. This structure is viewed face-on from the Sun making it susceptible to M31 satellite distance uncertainties. An estimation of the perpendicular velocity dispersion suggests that it is dynamically unstable. Finally we find that mass is not a property determining a satellite’s membership to good quality planes.
Power-law spectra from stochastic acceleration
Authors: Lemoine Martin , Malkov Mikhail A 
Published: October 2020

ABSTRACT
Numerical simulations of particle acceleration in magnetized turbulence have recently observed power-law spectra where pile-up distributions are rather expected. We interpret this as evidence for particle segregation based on acceleration rate, which is likely related to a non-trivial dependence of the efficacy of acceleration on phase space variables other than the momentum. We describe the corresponding transport in momentum space using continuous-time random walks, in which the time between two consecutive momentum jumps becomes a random variable. We show that power laws indeed emerge when the experimental (simulation) time-scale does not encompass the full extent of the distribution of waiting times. We provide analytical solutions, which reproduce dedicated numerical Monte Carlo realizations of the stochastic process, as well as analytical approximations. Our results can be readily extrapolated for applications to astrophysical phenomenology.
Recycled pulsars with multipolar magnetospheres from accretion-induced magnetic burial
Authors: Suvorov A G , Melatos A 
Published: October 2020

ABSTRACT
Many millisecond pulsars are thought to be old neutron stars spun up (‘recycled’) during an earlier accretion phase. They typically have relatively weak (≲109 G) dipole field strengths, consistent with accretion-induced magnetic burial. Recent data from the Neutron Star Interior Composition Explorer indicate that hotspots atop the recycled pulsar PSR J0030–0451 are not antipodal, so that the magnetic field cannot be that of a centred dipole. In this paper it is shown that multipolarity is naturally expected in the burial scenario because of equatorial field line compression. Grad–Shafranov equilibria are constructed to show how magnetic multipole moments can be calculated in terms of various properties, such as the amount of accreted mass and the crustal equation of state.
AstroSat view of GRS 1915+105 during the soft state: detection of HFQPOs and estimation of mass and spin
Authors: Sreehari H , Nandi Anuj , Das Santabrata , Agrawal V K , Mandal Samir , Ramadevi M C , Katoch Tilak 
Published: October 2020

ABSTRACT
We report the results of AstroSat observations of GRS 1915+105 obtained using 100 ks Guaranteed Time during the soft state. The colour–colour diagram indicates a variability class of δ with the detection of high-frequency quasi-periodic oscillation (HFQPO) in the power density spectra. The HFQPO is seen to vary in the frequency range of 67.96–70.62 Hz with percentage rms ∼0.83–1.90 per cent and significance varying from 1.63 to 7.75. The energy dependent power spectra show that the HFQPO features are dominant only in 6–25 keV energy band. The broad-band energy spectra (0.7–50 keV) of Soft X-ray Telescope and Large Area X-ray Proportional Counter modelled with nthComp and powerlaw imply that the source has an extended corona in addition to a compact ‘Comptonizing corona’ that produces high-energy emission and exhibits HFQPOs. The broad-band spectral modelling indicates that the source spectra are well described by thermal Comptonization with electron temperature (kTe) of 2.07–2.43 keV and photon index (Γnth) between 1.73 and 2.45 with an additional powerlaw component of photon index (ΓPL) between 2.94 and 3.28. The norm of nthComp component is high (∼8) during the presence of strong HFQPO and low (∼3) during the absence of HFQPO. Further, we model the energy spectra with the kerrbb model to estimate the accretion rate, mass, and spin of the source. Our findings indicate that the source accretes at super-Eddington rate of $1.17\!-\!1.31~ \dot{M}_{\rm Edd}$. Moreover, we find the mass and spin of the source as 12.44–13.09 M⊙ and 0.990–0.997 with $90{{\ \rm per\ cent}}$ confidence suggesting that GRS 1915+105 is a maximally rotating stellar mass X-ray binary black hole source.
Modified virial theorem for highly magnetized white dwarfs
Authors: Mukhopadhyay Banibrata , Sarkar Arnab , Tout Christopher A 
Published: October 2020

ABSTRACT
Generally the virial theorem provides a relation between various components of energy integrated over a system. This helps us to understand the underlying equilibrium. Based on the virial theorem we can estimate, for example, the maximum allowed magnetic field in a star. Recent studies have proposed the existence of highly magnetized white dwarfs (B-WDs), with masses significantly higher than the Chandrasekhar limit. Surface magnetic fields of such white dwarfs could be more than $10^{9}$ G with the central magnitude several orders higher. These white dwarfs could be significantly smaller in size than their ordinary counterparts (with surface fields restricted to about $10^9$ G). In this paper, we reformulate the virial theorem for non-rotating B-WDs in which, unlike in previous formulations, the contribution of the magnetic pressure to the magnetohydrostatic balance cannot be neglected. Along with the new equation of magnetohydrostatic equilibrium, we approach the problem by invoking magnetic flux conservation and by varying the internal magnetic field with the matter density as a power law. Either of these choices is supported by previous independent work and neither violates any important physics. They are useful while there is no prior knowledge of field profile within a white dwarf. We then compute the modified gravitational, thermal, and magnetic energies and examine how the magnetic pressure influences the properties of such white dwarfs. Based on our results we predict important properties of these B-WDs, which turn out to be independent of our chosen field profiles.
Failed and delayed protostellar outflows with high-mass accretion rates
Authors: Machida Masahiro N , Hosokawa Takashi 
Published: October 2020

ABSTRACT
The evolution of protostellar outflows is investigated under different mass accretion rates in the range ∼10−5–$10^{-2}\, {\rm M}_\odot$ yr−1 with 3D magnetohydrodynamic simulations. A powerful outflow always appears in strongly magnetized clouds with $B_0 \gtrsim B_{\rm 0, cr}\, =10^{-4} (M_{\rm cl}/100\, {\rm M}_\odot)$ G, where Mcl is the cloud mass. When a cloud has a weaker magnetic field, the outflow does not evolve promptly with a high-mass accretion rate. In some cases with moderate magnetic fields B0 slightly smaller than B0, cr, the outflow growth is suppressed or delayed until the infalling envelope dissipates and the ram pressure around the protostellar system is significantly reduced. In such an environment, the outflow begins to grow and reaches a large distance only during the late accretion phase. On the other hand, the protostellar outflow fails to evolve and is finally collapsed by the strong ram pressure when a massive (≳ 100 M⊙) initial cloud is weakly magnetized with B0 ≲ 100 μG. The failed outflow creates a toroidal structure that is supported by magnetic pressure and encloses the protostar and disc system. Our results indicate that high-mass stars form only in strongly magnetized clouds, if all high-mass protostars possess a clear outflow. If we would observe either very weak or no outflow around evolved protostars, it means that strong magnetic fields are not necessarily required for high-mass star formation. In any case, we can constrain the high-mass star formation process from observations of outflows.
MUSE Analysis of Gas around Galaxies (MAGG) – II: metal-enriched halo gas around z ∼ 1 galaxies
Authors: Dutta Rajeshwari , Fumagalli Michele , Fossati Matteo , Lofthouse Emma K , Prochaska J Xavier , Arrigoni Battaia Fabrizio , Bielby Richard M , Cantalupo Sebastiano , Cooke Ryan J , Murphy Michael T , O’Meara John M 
Published: October 2020

ABSTRACT
We present a study of the metal-enriched cool halo gas traced by Mg ii absorption around 228 galaxies at z ∼ 0.8–1.5 within 28 quasar fields from the MUSE Analysis of Gas around Galaxies survey. We observe no significant evolution in the Mg ii equivalent width versus impact parameter relation and in the Mg ii covering fraction compared to surveys at z ≲ 0.5. The stellar mass, along with distance from galaxy centre, appears to be the dominant factor influencing the Mg ii absorption around galaxies. With a sample that is 90 per cent complete down to a star formation rate of ≈0.1 $\rm M_\odot yr^{-1}$ and up to impact parameters ≈250–350 kpc from quasars, we find that the majority ($67^{+12}_{-15}$ per cent or 14/21) of the Mg ii absorption systems are associated with more than one galaxy. The complex distribution of metals in these richer environments adds substantial scatter to previously reported correlations. Multiple galaxy associations show on average five times stronger absorption and three times higher covering fraction within twice the virial radius than isolated galaxies. The dependence of Mg ii absorption on galaxy properties disfavours the scenario in which a widespread intragroup medium dominates the observed absorption. This leaves instead gravitational interactions among group members or hydrodynamic interactions of the galaxy haloes with the intragroup medium as favoured mechanisms to explain the observed enhancement in the Mg ii absorption strength and cross-section in rich environments.
Magnetic fields in star-forming systems – II: Examining dust polarization, the Zeeman effect, and the Faraday rotation measure as magnetic field tracers
Authors: Reissl Stefan , Stutz Amelia M , Klessen Ralf S , Seifried Daniel , Walch Stefanie 
Published: October 2020

ABSTRACT
The degree to which the formation and evolution of clouds and filaments in the interstellar medium is regulated by magnetic fields remains an open question. Yet the fundamental properties of the fields (strength and 3D morphology) are not readily observable. We investigate the potential for recovering magnetic field information from dust polarization, the Zeeman effect, and the Faraday rotation measure (RM) in a SILCC-Zoom magnetohydrodynamic (MHD) filament simulation. The object is analysed at the onset of star formation and it is characterized by a line-mass of about $\mathrm{\left(M/L\right) \sim 63\ \mathrm{M}_{\odot }\ pc^{-1}}$ out to a radius of $1\,$ pc and a kinked 3D magnetic field morphology. We generate synthetic observations via polaris radiative transfer (RT) post-processing and compare with an analytical model of helical or kinked field morphology to help interpreting the inferred observational signatures. We show that the tracer signals originate close to the filament spine. We find regions along the filament where the angular dependence with the line of sight (LOS) is the dominant factor and dust polarization may trace the underlying kinked magnetic field morphology. We also find that reversals in the recovered magnetic field direction are not unambiguously associated to any particular morphology. Other physical parameters, such as density or temperature, are relevant and sometimes dominant compared to the magnetic field structure in modulating the observed signal. We demonstrate that the Zeeman effect and the RM recover the line-of-sight magnetic field strength to within a factor 2.1–3.4. We conclude that the magnetic field morphology may not be unambiguously determined in low-mass systems by observations of dust polarization, Zeeman effect, or RM, whereas the field strengths can be reliably recovered.