bluuebunny/crossref_metadata_2025 huggingface dataset:
Biconical-dominated Accretion Flow onto Seed Black Holes in a Hyperaccretion Regime
Authors: Park KwangHo , Wise John H. , Bogdanović Tamara , Ricotti Massimo
Published: December 2020

Hyperaccretion occurs when the gas inflow rate onto a black hole (BH) is so high that the radiative feedback cannot reverse the accretion flow. This extreme process is a promising mechanism for the rapid growth of seed BHs in the early universe, which can explain high-redshift quasars powered by billion solar mass BHs. In theoretical models, spherical symmetry is commonly adopted for hyperaccretion flows; however, the sustainability of such structures on timescales corresponding to the BH growth has not been addressed yet. Here we show that stochastic interactions between the ionizing radiation from the BH and nonuniform accretion flow can lead to the formation of a rotating gas disk around the BH. Once the disk forms, the supply of gas to the BH preferentially occurs via biconical-dominated accretion flow perpendicular to the disk, avoiding the centrifugal barrier of the disk. Biconical dominated accretion flows from opposite directions collide in the vicinity of the BH supplying high-density, low angular momentum gas to the BH, whereas most of the gas with nonnegligible angular momentum is deflected to the rotationally supported outflowing decretion disk. The disk becomes reinforced progressively as more mass from the biconical flow transfers to the disk and some of the outflowing gas from the disk is redirected to the biconical accretion funnels through a meridional structure. This axisymmetric hydrodynamic structure of a biconical-dominated accretion flow and decretion disk continues to provide uninterrupted flow of high-density gas to the BH.
ZTF20aajnksq (AT 2020blt): A Fast Optical Transient at z ≈ 2.9 with No Detected Gamma-Ray Burst Counterpart
Authors: Ho Anna Y. Q. , Perley Daniel A. , Beniamini Paz , Cenko S. Bradley , Kulkarni S. R. , Andreoni Igor , Singer Leo P. , De Kishalay , Kasliwal Mansi M. , Fremling Christoffer , Bellm Eric C. , Dekany Richard , Delacroix Alexandre , Duev Dmitry A. , Goldstein Daniel A. , Golkhou V. Zach , Goobar Ariel , Graham Matthew J. , Hale David , Kupfer Thomas , Laher Russ R. , Masci Frank J. , Miller Adam A. , Neill James D. , Riddle Reed , Rusholme Ben , Shupe David L. , Smith Roger , Sollerman Jesper , van Roestel Jan
Published: December 2020

We present ZTF20aajnksq (AT 2020blt), a fast-fading (Δr = 2.3 mag in Δt = 1.3 days) red (g − r ≈ 0.6 mag) and luminous (M
1626 Å = −25.9 mag) optical transient at z = 2.9 discovered by the Zwicky Transient Facility (ZTF). AT 2020blt shares several features in common with afterglows to long-duration gamma-ray bursts (GRBs): (1) an optical light curve well-described by a broken power law with a break at t
j = 1 d (observer frame); (2) a luminous (L
0.3–10 KeV = 1046 erg s−1) X-ray counterpart; and (3) luminous (L
10 GHz = 4 × 1031 erg s−1 Hz−1) radio emission. However, no GRB was detected in the 0.74 days between the last ZTF nondetection (r > 21.36 mag) and the first ZTF detection (r = 19.60 mag), with an upper limit on the isotropic-equivalent gamma-ray energy release of E

γ,iso < 7 × 1052 erg. AT 2020blt is thus the third afterglow-like transient discovered without a detected GRB counterpart (after PTF11agg and ZTF19abvizsw) and the second (after ZTF19abvizsw) with a redshift measurement. We conclude that the properties of AT 2020blt are consistent with a classical (initial Lorentz factor Γ0 ≳ 100) on-axis GRB that was missed by high-energy satellites. Furthermore, by estimating the rate of transients with light curves similar to that of AT 2020blt in ZTF high-cadence data, we agree with previous results that there is no evidence for an afterglow-like phenomenon that is significantly more common than classical GRBs, such as dirty fireballs. We conclude by discussing the status and future of fast-transient searches in wide-field high-cadence optical surveys.
Study Turbulence and Probe Magnetic Fields Using the Gradient Technique: Application to H i-to-H2 Transition Regions
Authors: Hu Yue , Lazarian A. , Bialy Shmuel
Published: December 2020

The atomic-to-molecular (H i-to-H2) transition in photodissociation regions (PDRs) has been investigated over the past several decades through analytic and numerical modeling. However, classical PDR models typically assume a uniform-density gas, ignoring the turbulent nature of the interstellar medium. Recently, Bialy et al. have presented a theoretical framework for studying the H i-to-H2 transition in a realistic turbulent medium with a nonhomogeneous density structure. Here we extend these turbulent-chemical models to explore the possibility of tracing the magnetic field direction in turbulent PDRs using the gradient technique. We utilize both subsonic and supersonic magnetohydrodynamic numerical simulations for chemical H i/H2 balance calculations. We confirm that the density fluctuations induced by turbulence can disperse the distribution of the H2 and H i fractions. We find that the energy spectrum of moment maps gets shallower when the sonic Mach number M
S increases. We explore the ability in magnetic field tracing of gradients of higher-order velocity centroids and compare their performance with that of traditional velocity centroid gradients (VCGs) and with intensity gradients (IGs). We find that the velocity gradients of the second-order centroids (VC2Gs) are more accurate than VCGs and IGs in probing the magnetic field orientation.
The Betelgeuse Project. III. Merger Characteristics
Authors: Sullivan J. M. , Nance S. , Wheeler J. Craig
Published: December 2020

We previously proposed that Betelgeuse might have been spun up by accreting a companion of about 1 M
⊙. Here we explore in more detail the possible systematics of such a merger and a larger range of accreted masses. We use the stellar evolutionary code mesa to add angular momentum to a primary star in core helium burning, core carbon burning, or shell carbon burning. Our models provide a reasonable “natural” explanation for why Betelgeuse has a large, but sub-Keplerian equatorial velocity. They eject sufficient mass and angular momentum in rotationally induced mass loss to reproduce the observed ratio of the equatorial velocity to escape velocity of Betelgeuse, ≈0.23, within a factor of 3 nearly independent of the primary mass, the secondary mass, and the epoch at which merger occurs. Our models suggest that merger of a primary of somewhat less than 15 M
⊙ with secondaries from 1 to 10 M
⊙ during core helium burning or core carbon burning could yield the equatorial rotational velocity of ∼15 km s−1 attributed to Betelgeuse. For accreting models, a wave of angular momentum is halted at the composition boundary at the edge of the helium core. The inner core is thus not affected by the accretion of the companion in these simulations. Accretion has relatively little effect on the production of magnetic fields in the inner core. Our results do not prove, but do not negate, that Betelgeuse might have ingested a companion of several M
⊙.
Long-term Orbital Evolution of Galactic Satellites and the Effects on Their Star Formation Histories
Authors: Miyoshi Takahiro , Chiba Masashi
Published: December 2020

We investigate the orbital motions of dwarf spheroidal galaxies (dSphs) in the halo of the Milky Way (MW) to understand their possible effects on the diversity of the star formation histories seen in these MW satellites. In this work, we explicitly consider a time-varying gravitational potential due to the growth of the MW’s dark halo mass to calculate the long-term orbital evolutions of the dSphs, guided with Gaia DR2 proper motions, over the past 13.5 billion years. We find that the infall time of a satellite, defined as when the galaxy first crosses within the growing virial radius of the MW’s halo, coincides well with the time when the star formation rate (SFR) is peaked for the sample of classical dSphs. On the other hand, ultra-faint dSphs already finished their SF activity prior to their infall times as already suggested in previous works, but there is a signature that their earlier SF histories are affected by interaction with the growing MW’s halo to some extent. We also find, for classical dSphs, that the relative fraction of stars formed after the peak of the SFR to the current stellar mass is smaller for the smaller pericentric radius of the galaxy at its first infall. These results suggest that the infalling properties of the dSphs into the MW and the resultant environmental effects, such as ram pressure stripping and/or tidal disturbance in the MW’s dark halo containing hot gas, play important roles in their star formation histories.
The Pairing Probability of Massive Black Holes in Merger Galaxies in the Presence of Radiative Feedback
Authors: Li Kunyang , Bogdanović Tamara , Ballantyne David R.
Published: December 2020

Dynamical friction (DF) against stars and gas is thought to be an important mechanism for orbital evolution of massive black holes (MBHs) in merger remnant galaxies. Recent theoretical investigations, however, show that DF does not always lead to MBH inspiral. For MBHs evolving in gas-rich backgrounds, the ionizing radiation that emerges from the innermost parts of their accretion flow can affect the surrounding gas in such a way to cause the MBHs to accelerate and gain orbital energy. This effect was dubbed “negative DF.” We use a semianalytic model to study the impact of negative DF on pairs of MBHs in merger remnant galaxies evolving under the combined influence of stellar and gaseous DF. Our results show that for a wide range of merger galaxy and MBH properties negative DF reduces the MBH pairing probability by ∼46%. The suppression of MBH pairing is most severe in galaxies with one or more of these properties: (1) a gas fraction of f

g
 ≥ 0.1; (2) a galactic gas disk rotating close to the circular velocity; (3) MBH pairs in prograde, low eccentricity orbits; and (4) MBH pairs with mass <108
M
⊙. The last point is of importance because MBH pairs in this mass range are direct progenitors of merging binaries targeted by the future space-based gravitational wave observatory the Laser Interferometer Space Antenna (LISA).
A Framework for Relative Biosignature Yields from Future Direct Imaging Missions
Authors: Tuchow Noah W. , Wright Jason T.
Published: December 2020

Future exoplanet direct imaging missions, such as HabEx and LUVOIR, will select target stars to maximize the number of Earth-like exoplanets that can have their atmospheric compositions characterized. Because one of these missions’ aims is to detect biosignatures, they should also consider the expected biosignature yield of planets around these stars. In this work, we develop a method of computing relative biosignature yields among potential target stars, given a model of habitability and biosignature genesis, and using a star’s habitability history. As an illustration and first application of this method, we use MESA stellar models to calculate the time evolution of the habitable zone and examine three simple models for biosignature genesis to calculate the relative biosignature yield for different stars. We find that the relative merits of K stars versus F stars depend sensitively on model choice. In particular, use of the present-day habitable zone as a proxy for biosignature detectability favors young, luminous stars lacking the potential for long-term habitability. Biosignature yields are also sensitive to whether life can arise on Cold Start exoplanets that enter the habitable zone after formation, an open question deserving of more attention. Using the case study of biosignature yields calculated for θ Cygni and 55 Cancri, we find that robust mission design and target selection for HabEx and LUVOIR depend on choosing a specific model of biosignature appearance with time, the terrestrial planet occurrence rate as a function of orbital separation, precise knowledge of stellar properties, and accurate stellar evolutionary histories.
Physical Conditions of Gas Components in Debris Disks of 49 Ceti and HD 21997
Authors: Higuchi Aya E. , Kóspál Ágnes , Moór Attila , Nomura Hideko , Yamamoto Satoshi
Published: December 2020

Characterization of the gas component in debris disks is of fundamental importance for understanding their origin. To address this goal, we have conducted non-LTE (local thermodynamic equilibrium) analyses of the rotational spectral lines of CO including those of rare isotopologues (13CO and C18O) that have been observed toward the gaseous debris disks of 49 Ceti and HD 21997 with the Atacama Large Millimeter/submillimeter Array (ALMA) and the Atacama Compact Array (ACA). The analyses have been carried out for a wide range of H2 density, and the observed line intensities are found to be reproduced as long as the H2 density is higher than 103 cm−3. The CO column density and the gas temperature are evaluated to be (1.8–5.9) × 1017 cm−2 and 8–11 K for 49 Ceti and (2.6–15) × 1017 cm−2 and 8–12 K for HD 21997, respectively, where the H2 collision is assumed for the rotational excitation of CO. The results do not change significantly even if electron collision is considered. Thus, CO molecules can be excited under environments containing no H2 or a small number of H2 molecules, even where collisions with CO, C, O, and C+ would make an important contribution to the CO excitation in addition to H2. Meanwhile, our result does not rule out the case of abundant H2 molecules. The low gas temperature observed in the debris disks is discussed in terms of inefficient heating by interstellar and stellar UV radiation.
Flare Rates, Rotation Periods, and Spectroscopic Activity Indicators of a Volume-complete Sample of Mid- to Late-M Dwarfs within 15 pc
Authors: Medina Amber A. , Winters Jennifer G. , Irwin Jonathan M. , Charbonneau David
Published: December 2020

We present a study of flare rates, rotation periods, and spectroscopic activity indicators of 125 single stars within 15 parsecs and with masses between 0.1 and 0.3 M
⊙ observed during the first year of the TESS mission, with the goal of elucidating the relationship between these various magnetically connected phenomena. We gathered multiepoch high-resolution spectra of each target, and we measured equivalent widths of the activity indicators helium I D3, Hα, and the calcium infrared triplet line at 8542.09 Å. We present 18 new rotation periods from MEarth photometry and 19 new rotation periods from TESS photometry. We present a catalog of 1392 flares. After correcting for sensitivity, we find the slope of the flare frequency distribution for all stars to have a standard value of α = 1.98 ± 0.02. We determine R
31.5, the rate of flares per day with energies above E = 3.16 × 1031 ergs in the TESS bandpass. We find that below a critical value of Hα EW = −0.71 Å, log R
31.5 increases linearly with increasing Hα emission; above this value, log R
31.5 declines rapidly. The stars divide into two groups: 26% have Hα in emission, high flare rates with typical values of log R
31.5 = −1.30 ± 0.08, and have Rossby numbers <0.50. The remaining 74% show little to no Hα in emission and exhibit log R
31.5 < −3.86, with the majority of these stars not showing a single flare during the TESS observations.
SuperRAENN: A Semisupervised Supernova Photometric Classification Pipeline Trained on Pan-STARRS1 Medium-Deep Survey Supernovae
Authors: Villar V. Ashley , Hosseinzadeh Griffin , Berger Edo , Ntampaka Michelle , Jones David O. , Challis Peter , Chornock Ryan , Drout Maria R. , Foley Ryan J. , Kirshner Robert P. , Lunnan Ragnhild , Margutti Raffaella , Milisavljevic Dan , Sanders Nathan , Pan Yen-Chen , Rest Armin , Scolnic Daniel M. , Magnier Eugene , Metcalfe Nigel , Wainscoat Richard , Waters Christopher
Published: December 2020

Automated classification of supernovae (SNe) based on optical photometric light-curve information is essential in the upcoming era of wide-field time domain surveys, such as the Legacy Survey of Space and Time (LSST) conducted by the Rubin Observatory. Photometric classification can enable real-time identification of interesting events for extended multiwavelength follow-up, as well as archival population studies. Here we present the complete sample of 5243 “SN-like” light curves (in g
P1
r
P1
i
P1
z
P1) from the Pan-STARRS1 Medium-Deep Survey (PS1-MDS). The PS1-MDS is similar to the planned LSST Wide-Fast-Deep survey in terms of cadence, filters, and depth, making this a useful training set for the community. Using this data set, we train a novel semisupervised machine learning algorithm to photometrically classify 2315 new SN-like light curves with host galaxy spectroscopic redshifts. Our algorithm consists of an RF supervised classification step and a novel unsupervised step in which we introduce a recurrent autoencoder neural network (RAENN). Our final pipeline, dubbed SuperRAENN, has an accuracy of 87% across five SN classes (Type Ia, Ibc, II, IIn, SLSN-I) and macro-averaged purity and completeness of 66% and 69%, respectively. We find the highest accuracy rates for SNe Ia and SLSNe and the lowest for SNe Ibc. Our complete spectroscopically and photometrically classified samples break down into 62.0% Type Ia (1839 objects), 19.8% Type II (553 objects), 4.8% Type IIn (136 objects), 11.7% Type Ibc (291 objects), and 1.6% Type I SLSNe (54 objects).
The Herschel Orion Protostar Survey: Far-infrared Photometry and Colors of Protostars and Their Variations across Orion A and B*
Authors: Fischer William J. , Megeath S. Thomas , Furlan E. , Stutz Amelia M. , Stanke Thomas , Tobin John J. , Osorio Mayra , Manoj P. , Di Francesco James , Allen Lori E. , Watson Dan M. , Wilson T. L. , Henning Thomas
Published: December 2020

The degree to which the properties of protostars are affected by environment remains an open question. To investigate this, we look at the Orion A and B molecular clouds, home to most of the protostars within 500 pc. At ∼400 pc, Orion is close enough to distinguish individual protostars across a range of environments in terms of both the stellar and gas projected densities. As part of the Herschel Orion Protostar Survey (HOPS), we used the Photodetector Array Camera and Spectrometer to map 108 partially overlapping square fields with edge lengths of 5′ or 8′ and measure the 70 and 160 μm flux densities of 338 protostars within them. In this paper we examine how these flux densities and their ratio depend on evolutionary state and environment within the Orion complex. We show that Class 0 protostars occupy a region of the 70 μm flux density versus 160 μm/70 μm flux density ratio diagram that is distinct from their more evolved counterparts. We then present evidence that the Integral-Shaped Filament (ISF) and Orion B contain protostars with more massive inner envelopes than those in the more sparsely populated LDN 1641 region. This can be interpreted as evidence for increasing star formation rates in the ISF and Orion B or as a tendency for more massive inner envelopes to be inherited from denser birth environments. We also provide technical details about the mapmaking and photometric procedures used in the HOPS program.
Outflows in the Presence of Cosmic Rays and Waves
Authors: Ramzan B. , Ko C. M. , Chernyshov D. O.
Published: December 2020

Plasma outflow or wind against a gravitational potential under the influence of cosmic rays is studied in the context of hydrodynamics. Cosmic rays interact with the plasma via hydromagnetic fluctuations. In the process, cosmic rays advect and diffuse through the plasma. We adopt a multi-fluid model in which, besides thermal plasma, cosmic rays and self-excited Alfvén waves are also treated as fluids. We seek possible, physically allowable steady-state solutions of three-fluid (one Alfvén wave) and four-fluid (two Alfvén waves) models with given boundary conditions at the base of the potential well. Generally speaking, there are two classes of outflows—subsonic and supersonic (with respect to a suitably defined sound speed). A three-fluid model without cosmic-ray diffusion can be studied in the same way as the classic stellar wind problem, and is taken as a reference model. When cosmic-ray diffusion is included, there are two categories of solutions. One of them resembles the three-fluid model without diffusion, and the other behaves like thermal wind at large distances when the waves wither and cosmic rays are decoupled from the plasma. We also examine the effect of wave damping mechanisms (such as nonlinear Landau damping). Roughly speaking, the effect is much smaller in supersonic outflow than in subsonic outflow.
Lectotypification of five names in the genus Stellaria (Caryophyllaceae) in China
Authors: Wang Wenqiao , Su Zhiwei , Ma Zhonghui
Published: December 2020

Lectotypification for Stellaria depressa Em. Schmid, S. yunnanensis Franch., S. ebracteata Kom., S. filicaulis Makino, and S. pusilla Em. Schmid are designated here.
Arable Weeds and Management in Europe
Authors: Bürger Jana , Metcalfe Helen , von Redwitz Christoph , Cirujeda Alicia , Fogliatto Silvia , Fried Guillaume , Fu Dostatny Denise , Glemnitz Michael , Gerowitt Bärbel , González-Andújar José Luis , Hernández Plaza Eva , Izquierdo Jordi , Kolářová Michaela , Ņečajeva Jevgenija , Petit Sandrine , Pinke Gyula , Schumacher Matthias , Ulber Lena , Vidotto Francesco
Published: December 2020

“Arable Weeds and Management in Europe” is a collection of weed vegetation records from arable fields in Europe, initiated within the Working Group Weeds and Biodiversity of the European Weed Research Society (EWRS). Vegetation-plot data from this scientific community was not previously contributed to databases. We aim to prove the usefulness of collection for large scale studies through some first analyses. We hope to assure other weed scientists who have signalled willingness to share data, and plan to construct a full data base, making the data available for easy sharing. Presently, the collection has over 60,000 records, taken between 1996 and 2015. Many more studies for potential inclusion exist. Data originate mostly from studies exploring the effect of agricultural management on weed vegetation. The database is accompanied with extensive meta-data on crop and weed management on the surveyed fields. The criteria for inclusion were a minimum amount of information on the cultivated crop, and a georeference. Most fields were surveyed repeatedly, i.e. transects, multiple random plots, or repeated visits. All surveys aimed to record the complete vegetation on the plots. Sometimes, taxa were identified only to genus level, due to survey dates very early in the vegetation period. Plant taxonomy is standardized to the Euro+Med PlantBase.
A new species of Egglestonichthys (Teleostei, Gobiiformes, Gobiidae) from Okinawa Island, Japan
Authors: Fujiwara Kyoji , Suzuki Toshiyuki , Motomura Hiroyuki
Published: December 2020

Egglestonichthys fulmensp. nov.(Teleostei: Gobiidae) is described on the basis of a single specimen (21.7 mm in standard length) collected from 250 m depth off Okinawa Island, Ryukyu Islands, Japan. The new species is characterized by the following combination of characters: anal-fin rays I, 9; pectoral-fin rays 17, lower rays not free from membrane; longitudinal scale series 25; transverse scales 8; pre-dorsal-fin scale rows 8; cheek and opercle naked; pelvic frenum absent; caudal fin lanceolate, its length 32.2% of SL; interorbital width very narrow, 1.2% of HL (much narrower than pupil diameter); no spicules or odontoid processes on outer surface of gill arches; and body whitish, upper half with broken zigzag pattern of bright yellow patches and associated scattered black melanophores in fresh specimens (melanophores retained in preserved specimens). Several characters, including pectoral-fin ray count, interorbital width, and coloration uniquely distinguish the new species from congeners.
An analysis of wildlife strikes to aircraft in Brazil: 2011-2018
Authors: Mendonca Flavio A.C. , Keller Julius , Huang Chenyu
Published: December 2020

Purpose: Aircraft accidents due to wildlife hazards have become a growing safety and economic problem to the Brazilian and international aviation industries. These safety occurrences have resulted in significant direct and indirect economic losses as well injuries and fatalities worldwide. The purpose of this study was to develop empirical information obtained from the analysis of wildlife strike and aircraft operations data in Brazil that could be used for accident prevention efforts.Design/methodology: The research team collected and analyzed aircraft operations as well as wildlife strike data from the 32 busiest commercial airports in Brazil, from 2011 through 2018. Researchers obtained the number of aircraft operations at each of those 32 Brazilian airports from the Brazilian air traffic operations annual reports published by the Air Traffic Control Department. Wildlife strike data from the studied airports were obtained from the Brazilian national wildlife strike database. Descriptive data analysis was adopted to provide an intuitive and overall trend of wildlife strikes at and the 32 busiest commercial airports in Brazil.Findings: Results indicate that the number of wildlife strikes at and around the investigated airports increased 70% even though the number of aircraft operations at these airports declined by 12% during the period studied. Birds were involved in 88% of the reported events. Most reported strikes (59%) and damaging strikes (39%) occurred during the arrival phases-of-flight. Most (33%) strikes were reported by airport personnel. A finding of concern was that the majority of wildlife strikes (97%) and damaging wildlife strikes (96%) occurred within the airport environment.Originality/value: The current project contributes to the safety management of wildlife hazards in Brazil by conducting a comprehensive analysis of wildlife strike and aircraft operations data (2011-2018) in the 32 busiest Brazilian commercial airports.
A comparative study between ILS and GBAS approaches: The case of Viseu airfield
Authors: Oliveira Pedro , Silva Jorge , Soares Paulo
Published: December 2020

Purpose: The article aims to show the viability of installing a precision-based approach system in Viseu airfield, in Portugal. This work looks to evidence to what extent the implementation of ILS (Instrument Landing System) or GBAS (Ground Based Augmentation System) in the airfield is viable, and which of the two would be the better option for this case, from a technical and economic view and as a way to increase safety levels.Design/methodology/approach: The article analyses the airfield’s evolution over time and forecasts its movements for the future, over a 10-year period, by utilising two different models: multiple linear regression and IATA traffic forecasts. The different types of airfield taxes were also reviewed and their values were estimated for the following years. The equipment’s technical aspects and individual prices were analysed to accurately determine the time needed for the airfield to recover the investment done, allied with an 80% funding European project.Findings: Approach systems are being modernized, and throughout the years more airports and airfields are starting to replace old approach systems for satellite-based new ones. When compared to ILS, GBAS offers more advantages at a technical and economic level, and even for smaller airfields with a low traffic volume, sometimes it can be technically and economically possible to have such systems implemented.Originality/value: Studies about the implementation of new radio aids are usually prepared for big airports by airport operators or ANSPs before major investment projects. However, for most small regional airports in the country, where traffic is not near as big, such studies don’t exist, and for that reason, investigating the possibility of installing such kind of equipment is very important, especially taking into consideration the safety they provide and other benefits that naturally come up with it.
Yoga Tourism as a Quest for Mental and Physical Wellbeing
Authors: Charak Nikhil Singh , Sharma Priyanka , Chib Rajesh Singh
Published: December 2020

Yoga tourism has become an important part of the 'travel to feel well' trend. Yoga tourism can also be seen as a subset of wellness tourism. Yoga means the amalgamation of body, mind, and spirit. Yoga is widely believed as a source to diminish stress, improve breathing, strength, and improvement in flexibility. The data has been collected through primary and secondary sources (journals, articles, and newspapers). The current study is focusing on the linkages between wellness, spirituality, and yoga tourism through an examination of the motivations of tourists visiting Rishikesh, India. Present research is exploratory in nature conducted in 2019 in Rishikesh, India. The current study tried to explore this under-researched segment by interviewing and surveying yoga travellers visiting Rishikesh, India. Current research emphasized the effect of yoga tourism on the physical and mental healing of tourists at Himalayan destinations as well as the motivational characteristics of yoga tourists.
The Relationship Between Ethical Climate, Workplace Deviance, and Mindfulness
Authors: Akca Meltem , Yavuz Meltem , Akca İhsan
Published: December 2020

Development of postmodern organizational approaches in the knowledge-based business environment plays a major role on the gaining importance of knowledge-based talents and skills. Moreover, corporate governance-related progress impacts structures and implications of organizations. Enterprises must follow the rules required by the age and regard the innovations in order to maintain their assets and provide competitive advantage. For that reason, human-related innovations and practices are popular in the management area. In this perspective, ethics is one of the most significant issues in both business and social life. Enhancement of negative work outcomes triggers the efforts for the establishment of ethical climates. Increase of the workplace deviance of employees also influences the need of moderating variables in the relationship between ethical climates and deviance. This chapter mentions ethical climate, workplace deviance, and mindfulness. Moreover, relations between variables are discussed in reference to the literature.
The Dynamics of Employee Relationships in a Digitalized Workplace
Authors: Chakraborty Tanusree , Tripathi Malabika , Saha Somrita
Published: December 2020

Employees of this day are not confined only to the physical space that they occupy during office hours. Today's workstations are connected environments ensuring instant access to other employees and anything that employees need for work which goes beyond any communication barriers and as a result is changing employee experiences to better engaged, innovative, and efficient ones. All these changes have given way to alterations in employee interrelation dynamics within the boundaries of technological environments. The chapter leads to an understanding of how today's work culture has changed, what the digitized workplace looks like, the where and how of task-technology fits, and the model of interpersonal relationships. The chapter also talks about the related implications of media richness theory at workplace with special reference to digitized work environment and virtual reality. Further, the chapter brings in the challenges of cyberloafing and phubbing as consequences of the digitized workplace and how those affect performance and employee relations.
A Neuroimaging Study Protocol on the Motivational Structures of Physicians Belonging to Private and Public Health
Authors: Casado-Aranda Luis-Alberto , Fernández-Aguilar Carmen , Sánchez-Fernández Juan , Martín José Jesús Martín , Minué-Lorenzo Sergio
Published: December 2020

Health economics literature has demonstrated that physician motivation is related with three reasons—extrinsic motivation, intrinsic motivation, and prosocial motivation—and that this motivational structure is influenced by the type of organization in which they work. Yet this research proves insufficient to identify the origin of the physician's psychological motivations. To shed light on this gap, this chapter aims to outline a neuroimaging methodology which would prove useful to identify the neurocognitive motivational structures of hospital physicians with the proposes the design of several intrasubject laboratory experiments, using the functional neuroimaging technique magnetic resonance imaging (fMRI). Identifying the neuronal origin of doctors' motivational framework belonging to private or public health organizations would be a step forward in defining the most appropriate motivational plan for a medical profile working in different hospital environments.
Disputas diplomáticas e imprensa após a Guerra do Paraguai: a Missão Mitre de 1872 no La Nación e no Jornal do Commercio
Authors: Barcelos Ribeiro da Silva Ana Paula
Published: December 2020

Neste artigo, analisamos a missão diplomática de Bartolomé Mitre no Brasil, em 1872, por meio das páginas do La Nación e do Jornal do Commercio. Em um contexto de fortes tensões e disputas territoriais, o historiador, general e ex-presidente argentino esteve no Rio de Janeiro a fim de garantir o Tratado de Aliança (1865) e a desocupação do território paraguaio por forças aliadas. Sua visita tem grande repercussão nas imprensas brasileira e argentina. Assim, conjugamos história, diplomacia e imprensa, pensando seu papel na legitimação das ações diplomáticas e as relações entre políticas externa e interna nas décadas finais do Império.
Elisa Lynch como heroína nacional no stronismo: Representações de gênero, domesticidade e sufragismo
Authors: Neres da Silva Natania
Published: December 2020

O artigo tem por objetivo analisar os usos e apropriações políticas de Elisa Lynch, companheira do presidente paraguaio Francisco Solano López e personagem importante na Guerra da Tríplice Aliança (1864-1870). Episódio central da História do Paraguai, a Guerra e seus principais personagens foram exaustivamente estudados. Com Lynch não foi diferente: sua trajetória foi reconstruída em diversas obras biográficas. Caracterizada, ao final do conflito, como uma mulher vil e manipuladora, no século XX, durante o stronismo, Elisa Lynch foi alçada ao posto de heroína nacional, junto ao seu companheiro. Esta pesquisa reflete sobre os possíveis interesses políticos por trás dessa reabilitação.
Género y nacionalismo en la educación paraguaya: las mujeres en la historiografía escolar de la Guerra de la Triple Alianza
Authors: Alegre Benítez Carolina , Antonio Tudela Sancho
Published: December 2020

Este trabajo explora las representaciones de las mujeres en una selección de manuales escolares empleados en las escuelas paraguayas durante el período 1989-2020, con el objetivo de analizar el papel histórico atribuido a las mujeres en los relatos escolares acerca de la Guerra de la Triple Alianza (1864-1870). Se sostiene que a pesar del proceso de revisión del currículo escolar y la política educativa iniciado con la transición democrática en 1989 persisten las representaciones hegemónicas de las mujeres ligadas al nacionalismo, afianzando los roles tradicionales de género en el marco de una sociedad patriarcal.
A PSICOLOGIA ORGANIZACIONAL EM UMA PERSPECTIVA FENOMENOLÓGICA-HERMENÊUTICA: A PRODUTIVIDADE EM QUESTÃO
Authors: Montechiari Pietrani Elina Eunice , Lopez Calvo de Feijoo Ana Maria
Published: December 2020

Neste estudo procura-se explicitar como a exigência de produtividade se encontra presente no processo de treinamento e desenvolvimento que se articula nas organizações pela psicologia. Por meio de um pensar calcado na tecnocracia, a relação que o trabalhador detém com seu trabalho e, por tabela, sua qualificação, passou a ser medida pela sua produção, requisito fundamental para a manutenção do indivíduo na organização. Com base no pensamento fenomenológico-hermenêutico, tal como elaborado por Martin Heidegger, o objetivo deste artigo é apresentar outra proposta em psicologia e suas práticas no contexto corporativo. Nesta proposta, procura-se deslocar a ênfase depositada na produtividade excessiva para o processo singular, de forma a valorizar o modo como cada um se articula com sua tarefa laboral. Com isso, importa pensar como cada um se apropria de sua relação com o trabalho, considerando que a exigência de produção excessiva se edifica no contexto epocal no qual o trabalho e o trabalhador vêm se articulando e que Heidegger denomina de era da técnica.
O Fenômeno da Contemplação em Contextos de Consumo de Luxo
Authors: Aureliano-Silva Leonardo , Strehlau Suzane
Published: December 2020

O objetivo desse artigo é apresentar o fenômeno da contemplação e propor uma reflexão de sua aplicação no campo do marketing. A contemplação é um fenômeno psicológico e cognitivo no qual o indivíduo manifesta grande admiração por algo (MAY, 1982). Compreender esse fenômeno no campo do marketing traz contribuições teóricas para a área, sobretudo, no entendimento do desejo do consumidor por marcas de luxo. Ainda possibilita que gestores de marketing reflitam sobre estratégias de marketing que têm sido utilizadas com o objetivo de posicionar essas marcas para um grupo seleto de consumidores, que de fato, contemplam tais produtos.

Palavras-chave: contemplação, marcas de luxo, consumo, marketing, status
Avoiding complications in endoscopic trans-sphenoidal surgery for pituitary adenoma: A beginner's perspective
Authors: Goyal Pawan , Gupta Aditya , Srivastava Sanjeev , Modi Shilpi
Published: December 2020

Introduction: We aimed to analyze the difficulties and complications experienced while as a beginner in endoscopic transnasal transsphenoidal approach for pituitary adenomas. Materials and Methods: We retrospectively analyzed 83 cases done from June 2016 to August 2019. Navigation-guided endoscopic transnasal transsphenoidal approach was used in all the cases. Results: Gross total tumor removal was achieved in 55 (66.26%) patients. We found that gross total resection rate was inversely proportional to Knosp grading, and the extent of resection was found to have a statistically significant correlation with grade of tumor (P < 0.05). Surgery-related complications were present in 33 of our patients. Nasal complications occurred in six patients: three epistaxis (3.6%) and two hyposmia (2.4%) and one case of septal hematoma (1.2%). Postoperative cerebrospinal fluid leak occurred in six (7.2%) cases, two (2.4%) cases had sinusitis, while two (2.4%) cases had meningitis. There was a very rare case of subarachnoid hemorrhage and one case had sellar hematoma. Endocrinologic complications occurred in 15 (18.07%) patients: anterior pituitary deficiency in five (6.02%) patients, transient diabetes insipidus (DI) in nine (10.84%) patients, and permanent DI in one (1.2%) patient. There was no vascular injury or mortality noted in our study. Conclusion: Endoscopic approach is an effective modality for pituitary surgery; with patience, learning lessons from your own mistakes and by adopting right technique, learning curve can be flattened significantly.
A rare tumor of clivus masquerading as pituitary adenoma
Authors: Singh Swati , Mankotia Dipanker , Shankar Kepeemadam , Siraj Fouzia
Published: December 2020

Giant cell tumors (GCT) are generally benign, commonly affecting young adults, with a slight preponderance in females. They are locally aggressive with a high rate of local recurrence. Most of them are found in the epiphysis of long bones, making the base of the skull a rare site. We report the case of a 35-year-old female, who presented with neurological symptoms of headache and diplopia. On magnetic resonance imaging, a space-occupying lesion was discovered in the clivus. Histopathology was diagnostic of a GCT. GCT arising from the clivus is extremely uncommon, with about 15 cases published in the literature. The present case highlights the rarity of this tumor and contributes to the existing literature with analysis and evaluation of the management strategies and prognosis.
Management of metastatic spine and hip alveolar soft part sarcoma: Case report and review of literature
Authors: Shah Munjal , Gadia Akshay , Nene Abhay , Patel Priyank
Published: December 2020

Alveolar soft part sarcoma (ASPS) is a rare soft tissue tumor. Primary or metastatic involvement of the spine is unusual in ASPS. In most case, it is refractory to chemotherapy and radiation. Surgical resection is the most effective intervention. We report the case of a 38-year-old female having ASPS along with metastatic spine and hip involvement treated surgically as a single-stage operation, which is the first of its kind approach to our knowledge. We present the case of a 38-year-old female with simultaneous L4 pathological fracture with symptomatic lumbar canal stenosis without focal neurology and pathological fracture of neck of femur of left hip, secondary to metastatic ASPS. Since both conditions were contributing equally to her disability and demanded early intervention, they were treated simultaneously with intralesional excision of the tumor and posterior stabilization of the spine and left hip proximal femur resection and replaced it with proximal femur endoprosthesis as a single-stage operation. Postoperatively, she had significant relief of radiculopathy and left hip pain. She was mobilized out of bed on the postoperative day 1 and was discharged from hospital on the postoperative day 6. She was given chemotherapy drug sunitib postoperative. At her last follow-up, 20 months' postoperative, she was asymptomatic and was independent in terms of activities of daily living. Metastatic ASPS of the spine and hip is a rare clinical entity. Simultaneous surgical treatment of the spine and hip pathology is technically demanding. If the conditions demands, as in our case, both of them can be managed safely in a single-stage with good midterm outcome.
Traumatic cerebellar hematoma: A tertiary care experience of 23 conservatively managed cases
Authors: Singh Rahul , Pandey Nityanand , Singh Ramit
Published: December 2020

Context: Traumatic cerebellar hematomas are rare in comparison to nontraumatic cerebellar hematomas. Aims: The aim of this study is to evaluate the prognostic factors and outcome determining factors with regard to conservatively managed isolated traumatic cerebellar hematoma. Settings and Design: Retrospective cohort study. Materials and Methods: A retrospective study of 23 patients of conservatively managed isolated posterior fossa hematoma, admitted between August 2018 and May 2020, was conducted in the Department of Neurosurgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi. Each of the patients was evaluated in terms of age, sex, mode of injury, clinical presentation, comorbidity, the severity of injury, best motor response, Glasgow Coma Scale (GCS) at admission, computed tomography findings, and Glasgow Outcome Scale at discharge/death. Statistical Analysis: Chi-square test and unpaired t-test were used. P < 0.05 was deemed statistically significant. Results: Mean volume of posterior fossa contusion was 8.9 ml. The cerebellar hemispheric (60.9%) location of hematoma was more common. Age at presentation (P = 0.0086), best motor response (P < 0.0001), severity of injury (P = 0.0002), GCS at admission (P < 0.0001), effacement of basal cistern (P < 0.0001), fourth ventricular compression and intraventricular hemorrhage (P = 0.0008), presence of hydrocephalus (P = 0.0142), subarachnoid hemorrhage (P = 0.0008), and volume of posterior fossa contusion (P = 0.0002) were significantly associated with outcome of posterior fossa contusion. Conclusion: Traumatic cerebellar hematoma is rare. Conservatively managed cerebellar hematoma patients must be monitored closely for neurological and radiological status. Patients who show deterioration in neurological or radiological status require surgical intervention.
Analysis of a Regulated Cascode Cross Couple Power Amplifier
Authors: Tripetch Kittipong
Published: December 2020

The input impedance of a regulated cascode cross couple amplifier is derived. The frequency response of the input impedance polynomial form can be plotted with MATLAB. From the polynomial form of the input impedance of the proposed circuit, it can be transformed by substitute complex frequency s with jω into the polynomial form equation. After that, this function can be grouped into a symbolic real and a symbolic imaginary form. The next step in derivation is to multiply this function with a complex conjugate function of the symbolic complex form of the input impedance. The last step is to plot a real and an imaginary part as a function of the input frequency so that the power amplifier can be matching with the various matching circuit according to the condition of the maximum power transfer.
Neural Network Implementations on the coastal water quality of Manora channel for the years 1996 to 2014.
Authors: Ghayas Sidra , Sagheer Siddiquie Junaid , Safdar Suboohi , Mansoor Asif
Published: December 2020

Neural Networks is an Important Part of Computational Intelligence, Systems Theory and Signal Processing and finds numerous important applications in Science and Engineering. Sea water quality contaminates due to the severe untreated domestic, sewage and industrial pollutants. Presence of ammonia in seawater causes the deterioration of coastal water in terms of diminution of oxygen levels which suffocates the marine lives, fishes and mangroves. Industrial, sewage and domestic effluents carried by Lyari River contaminate the Manora channel, Karachi. The aim of study is to make the clear and transparent step-wise use of Artificial Neural Networks for the data driven water quality parameters models of Manora channel (Lyari river outfall zone N 24-51-26, E 66-58-01), Karachi (Pakistan) as well as to compare the pollutant contaminant ratio with the national environmental quality standard limits and other sampling sites of Manora channel and southern east Karachi coast. In this study, Manora channel Physico-chemical water quality parameters are assessed by using Artificial Neural Network taking Biochemical Oxygen Demand (BOD), chemical oxygen Demand (COD), Bicarbonates, potential Hydrogen(pH) , Chloride(Cl) as input and Ammonia(NH3)as output. Mean Square Error and R square are used for the model assessments statistical metrics. The computational work has been done by using R-studio. This is also found that Manora channel has the contaminated level of ammonia along the other sampling stations of both southern Karachi coast (N 24-47-03 E 67-08-39) as well as the other sampling site of Manora channel Karachi coast (N 24-50-15, E 66-58-01). In spite of all contamination Ammonia is found to be within National Environmental Quality Standards limits of Pakistan.