bluuebunny/crossref_metadata_2025_split huggingface dataset:
The relationship between black hole accretion rate and gas properties at the Bondi radius
Authors: Bu De-Fu 
Published: January 2021

AbstractThe mass accretion rate determines the black hole accretion mode and the corresponding efficiency of active galactic nuclei (AGNs) feedback. In large-scale simulations studying galaxy formation and evolution, the Bondi radius can be at most marginally resolved. In these simulations, the Bondi accretion formula is always used to estimate the black hole accretion rate. The Bondi solution can not represent the real accretion process. We perform 77 simulations with varying density and temperature at Bondi radius. We find a formula to calculate the black hole accretion rate based on gas density and temperature at Bondi radius. We find that the formula can accurately predict the luminosity of observed low-luminosity AGNs. This formula can be used in sub-grid models in large-scale simulations with AGNs feedback.
The role of AGN in galaxy star formation: A case study of a radio galaxy at z = 2.6
Authors: Man Allison 
Published: January 2021

AbstractRadio galaxies are ideal sites to scrutinize AGN feedback physics, as they are massive galaxies with jets that interact with the surrounding ISM. I will present a detailed analysis of the recent star formation history and conditions of a starbursting, massive radio galaxy at z = 2.6, PKS 0529-549. In the 8.5-hour VLT/X-Shooter spectrum, we detect unambiguous signatures of stellar photospheric absorption lines originating from OB-stars. Comparison with model spectra shows that more than one burst took place in its recent past: the most recent one at 4 − 7 Myr, and another aged ⩾20 Myr. ALMA observations of the [CI] atomic carbon emission line indicates that it has a low molecular gas fraction (∼13%) and short depletion time (∼40 Myr). Most intriguing is the modest velocity dispersion (⩽50 km/s) of these photospheric lines and the ALMA [CI] cold gas. We attribute its efficient star formation to compressive gas motions, induced by radio jets and/or interaction. Star formation works in concert with the AGN to remove any residual molecular gas and eventually leads to quenching.
The spins of supermassive black holes
Authors: Chary Ranga-Ram 
Published: January 2021

AbstractWe present 1-second cadence, precise optical observations from SOFIA and Palomar of a sample of nearby supermassive black holes. The observations were taken to identify the shortest timescale variability in the nuclear photometry which may be associated with instabilities in the accretion flow in the immediate vicinity of the black hole. The shortest timescale variability, if associated with the radius of the innermost stable circular orbit (ISCO), can then be used to estimate the spin of the black hole. Despite 1% precision photometry, we obtained a non-detection of any significant variability in the nucleus of M32 (Mbh ∼ 2.5 × 106 Mȯ). Given the density of the stellar cusp, this argues for a scenario where 1000 Msun seed black holes formed from the coalescence of less massive black holes, which then accrete the gas produced by stellar interactions/winds. In more luminous systems however, we find a significant deection of variability and present hypotheses to explain the signal and thereby the origin of supermassive black holes.
Supermassive black hole seed formation and the impact on black hole populations across cosmic time
Authors: DeGraf Colin 
Published: January 2021

AbstractAlthough it is well understood that supermassive black holes are found in essentially all galaxies, the mechanisms by which they initially form remain highly uncertain, despite the importance that the formation pathway can have on AGN and quasar behaviour at all redshifts. Using a post-processing analysis method combining cosmological simulations and analytic modeling, I will discuss how varying the conditions for formation of supermassive black hole seeds leads to changes in AGN populations. Looking at formation via direct collapse or from PopIII remnants, I will discuss the impact on black hole mass and luminosity functions, scaling relations, and black hole mergers, which each have effects at both high- and low-redshifts. In addition to demonstrating the importance of initial seed formation on our understanding of long-term black hole evolution, I will also show that the signatures of seed formation suggest multiple means by which upcoming electromagnetic and GW surveys (at both high- and low-z) can provide the data required to constrain initial supermassive black hole formation.
Multiwavelength morphological study of active galaxies
Authors: Bilata-Woldeyes Betelehem , Pović Mirjana , Beyoro-Amado Zeleke , Getachew-Woreta Tilahun , Terefe Shimeles 
Published: January 2021

AbstractStudying the morphology of a large sample of active galaxies at different wavelengths and comparing it with active galactic nuclei (AGN) properties, such as black hole mass (MBH) and Eddington ratio (λEdd), can help us in understanding better the connection between AGN and their host galaxies and the role of nuclear activity in galaxy formation and evolution. By using the BAT-SWIFT hard X-ray public data and by extracting those parameters measured for AGN and by using other public catalogues for parameters such as stellar mass (M*), star formation rate (SFR), bolometric luminosity (Lbol), etc., we studied the multiwavelength morphological properties of host galaxies of ultra-hard X-ray detected AGN and their correlation with other AGN properties. We found that ultra hard X-ray detected AGN can be hosted by all morphological types, but in larger fractions (42%) they seem to be hosted by spirals in optical, to be quiet in radio, and to have compact morphologies in X-rays. When comparing morphologies with other galaxy properties, we found that ultra hard X-ray detected AGN follow previously obtained relations. On the SFR vs. stellar mass diagram, we found that although the majority of sources are located below the main sequence (MS) of star formation (SF), still non-negligible number of sources, with diverse morphologies, is located on and/or above the MS, suggesting that AGN feedback might have more complex influence on the SF in galaxies than simply quenching it, as it was suggested in some of previous studies.
Optical spectroscopy of type-2 LINERs
Authors: Hermosa Muñoz Laura , Cazzoli Sara , Márquez Isabel , Masegosa Josefa 
Published: January 2021

AbstractLow-Ionisation Nuclear Emission-line Regions (LINERs) are the least luminous and the most numerous among the local population of Active Galactic Nuclei (AGN). They can be classified as type-1 or type-2 if their optical spectra show or do not show, respectively, a broad component. It is associated with the presence of a Broad Line Region (BLR) in these systems. However, recent studies have proven that the classification of type-1 LINERs may be controversial, since space- and ground-based spectroscopy provide contradicting results on the presence of very broad components (Cazzoli et al.2018). We have studied the nuclear spectra of 9 type-2 LINERs with intermediate spectral resolution HST/STIS data. We present the results on our analysis of the different spectral components, and discuss the eventual presence of BLR components in type-2 LINER galaxies, together with the possible presence of outflows, both in comparison with type-1 LINERs. We have found a BLR component in 7 out of the 9 analysed objects within the HST/STIS data.
Jet opening angle and linear scale of launch region of blazars
Authors: Liu Xiang , Jiang Pengfei , Cui Lang 
Published: January 2021

AbstractWe explore the intrinsic jet opening angle (IJOA) of blazars, from the literature, we found that the blazar number density peaks around 0.5° of IJOA and declines quickly with increasing IJOA for flat spectrum radio quasars (FSRQs), while the number density has double peaks around 0.3° and 2.0° of IJOA for BL Lacs. We assume that the black hole accretion-produced jet may have the smaller IJOA (for its larger linear scale of launch region), and the BH spin-produced jet may have the larger IJOA (for its smaller launch region), such that the FSRQs are accretion dominated for their single peaked small IJOA, while the BL Lacs are either accretion or BH spin dominated for their double peaked IJOA.
Catalogue with visual morphological classification of 32,616 radio galaxies with optical hosts
Authors: Żywucka Natalia , Koziel-Wierzbowska Dorota , Goyal Arti 
Published: January 2021

AbstractWe present the catalogue of Radio sources associated with Optical Galaxies and having Unresolved or Extended morphologies I (ROGUE I). It was generated by cross-matching galaxies from the Sloan Digital Sky Survey Data Release 7 (SDSS DR 7) as well as radio sources from the First Images of Radio Sky at Twenty Centimetre (FIRST) and the National Radio Astronomical Observatory VLA Sky Survey (NVSS) catalogues. We created the largest handmade catalogue of visually classified radio objects and associated with them optical host galaxies, containing 32,616 galaxies with a FIRST core within 3 arcsec of the optical position. All listed objects possess the good quality SDSS DR 7 spectra with the signal-to-noise ratio > 10 and spectroscopic redshifts up to z = 0.6. The radio morphology classification was performed by a visual examination of the FIRST and the NVSS contour maps overlaid on a DSS image, while an optical morphology classification was based on the 120 arcsec snapshot images from SDSS DR 7.The majority of radio galaxies in ROGUE I, i.e. ∼ 93%, are unresolved (compact or elongated), while the rest of them exhibit extended morphologies, such as Fanaroff-Riley (FR) type I, II, and hybrid, wide-angle tail, narrow-angle tail, head-tail sources, and sources with intermittent or reoriented jet activity, i.e. double–double, X–shaped, and Z–shaped. Most of FR IIs have low radio luminosities, comparable to the luminosities of FR Is. Moreover, due to visual check of all radio maps and optical images, we were able to discover or reclassify a number of radio objects as giant, double–double, X–shaped, and Z–shaped radio galaxies. The presented sample can serve as a database for training automatic methods of identification and classification of optical and radio galaxies.
X-ray variability plane revisited: Role of obscuration
Authors: González-Martn Omaira 
Published: January 2021

AbstractScaling relations are the most powerful astrophysical tools to set constraints to the physical mechanisms of astronomical sources and to infer properties for objects where they cannot be accessed directly. We have re-investigated one of these scaling relations using powerful type 1 Seyferts; the so-called X-ray variability plane (or mass-luminosity-timescale relation, McHardy et al.2006). This relation links the power-spectral density (PSD) break frequency with the SMBH mass and the bolometric luminosity. We used all available XMM-Newton observations to study the PSD and spectra in short segments within each observation. This allows us to report for the first time that the PSD break frequency varies for each object, showing variations in 19 out of the 22 AGN analyzed. Our analysis of the variability plane confirms the relation between the break frequency and the SMBH mass and finds that the obscuration along the line of sight (or the variations on the obscuration using its standard deviation) is also a required parameter. We constrain a new variability plane of the form: log(vBreak) = – A log (MBH) + B log (NH) – C (or log(vBreak) = – A log (MBH) + B Δ (NH) + C). The X-ray variability plane found by McHardy et al. (2006) is roughly recovered when we use unobscured segments. We speculate the PSD shape is related with the outflowing wind close to the accretion disk at least for these powerful type 1 AGN (Gonzalez-Martin et al. 2018).
The impact of CMEs on the critical frequency of F2-layer ionosphere (foF2)
Authors: Seyoum Alene , Gopalswamy Nat , Nigussie Melessew , Mezgebe Nigusse 
Published: January 2021

AbstractThe ionospheric critical frequency (foF2) from ionosonde measurements at geographic high, middle, and low latitudes are analyzed with the occurrence of coronal mass ejections (CMEs) in long term variability of the solar cycles. We observed trends of monthly maximum foF2 values and monthly averaged values of CME parameters such as speed, angular width, mass, and kinetic energy with respect to time. The impact of CMEs on foF2 is very high at high latitudes and low at low latitudes. The time series for monthly maximum foF2 and monthly-averaged CME speed are moderately correlated at high and middle latitudes.
Electron-proton interaction in radio sources
Authors: Obini Halima Ugomma 
Published: January 2021

AbstractA method of treating electron-proton interaction is presented. The energies involved in the interaction are estimated. Only elastic collisions are considered. The cross sections of the processes are not taken into account. Calculations are carried out in the centre of mass frame. Relevant quantities are transformed into the laboratory frame. Results indicate that the energy per collision gained by an electron ranges from 0.5 MeV to 0.6 MeV, under suitable conditions.
Floodplain Wetland Channel Planform, Cross‐Sectional Morphology, and Sediment Characteristics Along an Estuarine to Tidal River Gradient
Authors: Diefenderfer Heida L. , Borde Amy B. , Cullinan Valerie I. 
Published: January 2021

AbstractThe formation of wetland channel networks on coastal river floodplains is affected by spatial transitions in tidal‐fluvial processes. This study evaluated sedimentation patterns in tidal marshes on the 147‐km tidal Columbia River and its 87‐km estuary and characterized the cross‐sectional geometry and planform morphometry of tidal wetlands along the estuarine to riverine gradient. Tidal marshes were predominantly depositional (median 0.7 cm yr−1, primarily silt), consistent with late‐Holocene rates. Marsh sediment accretion rate increased with annual maximum 7‐day average daily maximum water depth. Elevation was negatively correlated with accretion rate in the tidal river and positively correlated with total organic carbon (TOC%) in the tidal river and estuary. TOC% was greater in the estuary and, like percent fines, greater farther from the main‐channel Columbia River. For four single‐channel and six channel‐network planforms of tidal marsh, shrub‐dominated, and forested wetlands: (1) Spatial patterns of cross‐sectional morphology conformed to typical coastal wetland morphology in estuarine reaches up to the tidal river. (2) Reach‐based and common slope linear models for channel perimeter on wetland area were predictive in the estuary (R2 > 0.81) and differed between island (n = 144) and mainland (n = 164) wetlands. No planform linear models were predictive for the entire study area or the tidal river. No models for channel outlets were acceptable. (3) Channel perimeter, surface area, and outlets were all highly variable within and among estuarine–riverine reaches. Analyses of sediment, cross‐section, and planform support the use of a “natural network paradigm” for wetland‐restoration design on tidal river floodplains.
Micro/nanodevices for assessment and treatment in stomatology and ophthalmology
Authors: Sheng An’an , Lin Long , Zhu Jia , Zhuang Jian , Li Jian , Chang Lingqian , Cheng Huanyu 
Published: January 2021

AbstractMicro/nanodevices have been widely applied for the real-time monitoring of intracellular activities and the delivery of exogenous substances in the past few years. This review focuses on miniaturized micro/nanodevices for assessment and treatment in stomatology and ophthalmology. We first summarize the recent progress in this field by examining the available materials and fabrication techniques, device design principles, mechanisms, and biosafety aspects of micro/nanodevices. Following a discussion of biochemical sensing technology from the cellular level to the tissue level for disease assessment, we then summarize the use of microneedles and other micro/nanodevices in the treatment of oral and ocular diseases and conditions, including oral cancer, eye wrinkles, keratitis, and infections. Along with the identified key challenges, this review concludes with future directions as a small fraction of vast opportunities, calling for joint efforts between clinicians and engineers with diverse backgrounds to help facilitate the rapid development of this burgeoning field in stomatology and ophthalmology.
Rosmarinic acid suppresses tau phosphorylation and cognitive decline by downregulating the JNK signaling pathway
Authors: Yamamoto So , Kayama Tomoko , Noguchi-Shinohara Moeko , Hamaguchi Tsuyoshi , Yamada Masahito , Abe Keiko , Kobayashi Shoko 
Published: January 2021

AbstractRosmarinic acid (RA), a polyphenol found in Lamiaceae herbs, is a candidate of preventive ingredients against Alzheimer’s disease (AD) as it potently suppresses the aggregation of amyloid β (Aβ); however, the effect of RA on tau phosphorylation and cognitive dysfunction remains unclear. The present study revealed that RA intake inhibited the pathological hallmarks of AD, including Aβ and phosphorylated tau accumulation, and improved cognitive function in the 3 × Tg-AD mouse model. Additionally, RA intake suppressed hippocampal inflammation and led to the downregulation of the JNK signaling pathway that induces tau phosphorylation. Feeding with RA exerted an anti-inflammatory effect not only in the central nervous system but also in the periphery. Downregulation of the JNK signaling pathway in hippocampus may be a potential mechanism underlying the inhibition of progression of pathology and cognitive deficit by RA feeding.
A single-dose live attenuated chimeric vaccine candidate against Zika virus
Authors: Chin Wei-Xin , Lee Regina Ching Hua , Kaur Parveen , Lew Tian Sheng , Yogarajah Thinesshwary , Kong Hao Yuin , Teo Zi-Yun , Salim Cyrill Kafi , Zhang Rong-Rong , Li Xiao-Feng , Alonso Sylvie , Qin Cheng-Feng , Chu Justin Jang Hann 
Published: January 2021

AbstractThe mosquito-borne Zika virus is an emerging pathogen from the Flavivirus genus for which there are no approved antivirals or vaccines. Using the clinically validated PDK-53 dengue virus vaccine strain as a backbone, we created a chimeric dengue/Zika virus, VacDZ, as a live attenuated vaccine candidate against Zika virus. VacDZ demonstrates key markers of attenuation: small plaque phenotype, temperature sensitivity, attenuation of neurovirulence in suckling mice, and attenuation of pathogenicity in interferon deficient adult AG129 mice. VacDZ may be administered as a traditional live virus vaccine, or as a DNA-launched vaccine that produces live VacDZ in vivo after delivery. Both vaccine formulations induce a protective immune response against Zika virus in AG129 mice, which includes neutralising antibodies and a strong Th1 response. This study demonstrates that VacDZ is a safe and effective vaccine candidate against Zika virus.
Synthetic skull bone defects for automatic patient-specific craniofacial implant design
Authors: Li Jianning , Gsaxner Christina , Pepe Antonio , Morais Ana , Alves Victor , von Campe Gord , Wallner Jürgen , Egger Jan 
Published: January 2021

AbstractPatient-specific craniofacial implants are used to repair skull bone defects after trauma or surgery. Currently, cranial implants are designed and produced by third-party suppliers, which is usually time-consuming and expensive. Recent advances in additive manufacturing made the in-hospital or in-operation-room fabrication of personalized implants feasible. However, the implants are still manufactured by external companies. To facilitate an optimized workflow, fast and automatic implant manufacturing is highly desirable. Data-driven approaches, such as deep learning, show currently great potential towards automatic implant design. However, a considerable amount of data is needed to train such algorithms, which is, especially in the medical domain, often a bottleneck. Therefore, we present CT-imaging data of the craniofacial complex from 24 patients, in which we injected various artificial cranial defects, resulting in 240 data pairs and 240 corresponding implants. Based on this work, automatic implant design and manufacturing processes can be trained. Additionally, the data of this work build a solid base for researchers to work on automatic cranial implant designs.
An exceptionally high wave at the CNR-ISMAR oceanographic tower in the Northern Adriatic Sea
Authors: Cavaleri Luigi , Barbariol Francesco , Bastianini Mauro , Benetazzo Alvise , Bertotti Luciana , Pomaro Angela 
Published: January 2021

AbstractOn December 15, 2009, a very high wave crest was recorded by a local camera at the CNR-ISMAR oceanographic tower, 15 km offshore Venice in the Northern Adriatic Sea (Italy). The height of the estimated crest elevation appears well beyond the value (1,25·Hs) commonly used to identify a wave as freak. We document the wave event with a full description of the corresponding met-ocean conditions and related measurements, of which we provide a critical analysis.
Nelumbo genome database, an integrative resource for gene expression and variants of Nelumbo nucifera
Authors: Li Hui , Yang Xingyu , Zhang Yue , Gao Zhiyan , Liang Yuting , Chen Jinming , Shi Tao 
Published: January 2021

AbstractSacred lotus (Nelumbo nucifera, or lotus) is one of the most widely grown aquatic plant species with important uses, such as in water gardening and in vegetable and herbal medicine. A public genomic database of lotus would facilitate studies of lotus and other aquatic plant species. Here, we constructed an integrative database: the Nelumbo Genome Database (NGD, http://nelumbo.biocloud.net). This database is a collection of the most updated lotus genome assembly and contains information on both gene expression in different tissues and coexpression networks. In the NGD, we also integrated genetic variants and key traits from our 62 newly sequenced lotus cultivars and 26 previously reported cultivars, which are valuable for lotus germplasm studies. As applications including BLAST, BLAT, Primer, Annotation Search, Variant and Trait Search are deployed, users can perform sequence analyses and gene searches via the NGD. Overall, the valuable genomic resources provided in the NGD will facilitate future studies on population genetics and molecular breeding of lotus.
Survival of hypoxia-induced dormancy is not a common feature of all strains of the Mycobacterium tuberculosis complex
Authors: Tizzano Barbara , Dallenga Tobias K. , Utpatel Christian , Behrends Jochen , Homolka Susanne , Kohl Thomas A. , Niemann Stefan 
Published: January 2021

AbstractWhile persistence in a dormant state is crucial for the life cycle of Mycobacterium tuberculosis, no investigation regarding dormancy survival of different strains across different lineages was performed so far. We analyzed responses to oxygen starvation and recovery in terms of growth, metabolism, and transcription. All different strains belonging to the Euro-American lineage (L4) showed similar survival and resuscitation characteristics. Different clinical isolates from the Beijing (L2), East African-Indian (L3), and Delhi/Central Asian (L1) lineage did not survive oxygen starvation. We show that dormancy survival is lineage-dependent. Recovery from O2 starvation was only observed in strains belonging to the Euro-American (L4) lineage but not in strains belonging to different lineages (L1, L2, L3). Thus, resuscitation from dormancy after oxygen starvation is not a general feature of all M. tuberculosis strains as thought before. Our findings are of key importance to understand infection dynamics of non-Euro-American vs Euro-American strains and to develop drugs targeting the dormant state.