Abstract Observed and simulated galaxies exhibit a significant variation in their velocity dispersion profiles. We examine the inner and outer slopes of stellar velocity dispersion profiles using ...integral field spectroscopy data from two surveys, SAMI (for z < 0.115) and CALIFA (for z < 0.03), comparing them with results from two cosmological hydrodynamic simulations: Horizon-AGN (for z = 0.017) and NewHorizon (for z ≲ 1). The simulated galaxies closely reproduce the variety of velocity dispersion slopes and stellar mass dependence of both inner and outer radii (0.5 r 50 and 3 r 50 ) as observed, where r 50 stands for half-light radius. The inner slopes are mainly influenced by the relative radial distribution of the young and old stars formed in situ: a younger center shows a flatter inner profile. The presence of accreted (ex situ) stars has two effects on the velocity dispersion profiles. First, because they are more dispersed in spatial and velocity distributions compared to in situ formed stars, it increases the outer slope of the velocity dispersion profile. It also causes the velocity anisotropy to be more radial. More massive galaxies have a higher fraction of stars formed ex situ and hence show a higher slope in outer velocity dispersion profile and a higher degree of radial anisotropy. The diversity in the outer velocity dispersion profiles reflects the diverse assembly histories among galaxies.
ABSTRACT We present a new database of our two-dimensional bulge-disk decompositions for 14,233 galaxies drawn from Sloan Digital Sky Survey DR12 in order to examine the properties of bulges residing ...in the local universe (0.005 < z < 0.05). We performed decompositions in the g and r bands by utilizing the galfit software. The bulge colors and bulge-to-total ratios are found to be sensitive to the details in the decomposition technique, and hence we hereby provide full details of our method. The g − r colors of bulges derived are almost constantly red regardless of bulge size, except for the bulges in the low bulge-to-total ratio galaxies (B/Tr 0.3). Bulges exhibit similar scaling relations to those followed by elliptical galaxies, but the bulges in galaxies with lower bulge-to-total ratios clearly show a gradually larger departure in slope from the elliptical galaxy sequence. The scatters around the scaling relations are also larger for the bulges in galaxies with lower bulge-to-total ratios. Both the departure in slopes and larger scatters likely originate from the presence of young stars. The bulges in galaxies with low bulge-to-total ratios show signs of a frosting of young stars so substantial that their luminosity-weighted Balmer-line ages are as small as 1 Gyr in some cases. While bulges seem largely similar in optical properties to elliptical galaxies, they do show clear and systematic departures as a function of bulge-to-total ratio. The stellar properties and perhaps associated formation processes of bulges seem much more diverse than those of elliptical galaxies.
In this study a total of 63 cubic specimens were prepared to investigate the pullout behaviors of the sand-coated and helically-wrapped GFRP bars as well as steel bars in concretes reinforced with ...structural fibers (steel, PP and PVA fibers). The results of direct pull-out testing were presented and analyzed with the aim of elucidating the effect of surface treatment of bar, fiber type, and fiber volume fraction in interface and suggesting the effective evaluation method for the improved ductility. The structural fibers in the interface changed the interfacial bond behaviors before and after the maximum stress and resulted in significant improvement of the relative bond strength, but bond failure modes largely depended on the interfacial property with the rebar. The fiber’s crack closing resistance, determined by evaluating both the residual bond strength and toughness indices, was used to determine optimum amount and type of fibers in the composites. The closing pressures due to PVA and hook end steel fibers had a good effect on resisting and controlling the interfacial crack initiation, growth, and propagation.
Aim
To examine the properties of Schisandrin C as an anti‐inflammatory and antioxidant compound, and whether its characteristics promote mitochondrial biogenesis in human dental pulp cells (HDPCs).
...Methodology
HDPCs were extracted from fresh third molars and cultured for experiments. Reactive oxidative stress (ROS) and nitric oxide (NO) formation were analysed by a Muse cell analyser. Western blotting and gelatin zymography were used to identify the presence of antioxidants, as well as anti‐inflammatory and mitochondrial biogenesis with specific antibody. An unpaired Student's t‐test was used for statistical analysis.
Results
Schisandrin C inhibited lipopolysaccharide‐stimulated inflammatory molecules; interleukin 1 beta, tumour necrosis factor alpha, intracellular adhesion molecule‐1, vascular cell adhesion molecule‐1, matrix metalloproteinase‐2 and ‐9, NO production, ROS formation, nuclear factor kappa B translocation (P < 0.05) through the mitogen‐activated protein kinase pathway. Schisandrin C increased the expression of superoxide dismutase enzymes as well as haem oxygenase‐1 and peroxisome proliferator‐activated receptor gamma coactivator 1‐alpha through the phosphorylated‐protein kinase B (p‐Akt) and nuclear factor erythroid 2‐related factor‐2 pathways (P < 0.05). The anti‐inflammatory and antioxidant properties of Schisandrin C promoted mitochondrial biogenesis.
Conclusions
Schisandrin C has the potential to reduce inflammation and oxidation and to promote mitochondrial biogenesis. Therefore, Schisandrin C may be considered for use as an anti‐inflammatory compound for oral inflammation through mitochondrial biogenesis.
We conduct a comprehensive numerical study of the orbital dependence of harassment on early-type dwarfs consisting of 168 different orbits within a realistic, Virgo-like cluster, varying in ...eccentricity and pericentre distance. We find harassment is only effective at stripping stars or truncating their stellar discs for orbits that enter deep into the cluster core. Comparing to the orbital distribution in cosmological simulations, we find that the majority of the orbits (more than three quarters) result in no stellar mass loss. We also study the effects on the radial profiles of the globular cluster systems of early-type dwarfs. We find these are significantly altered only if harassment is very strong. This suggests that perhaps most early-type dwarfs in clusters such as Virgo have not suffered any tidal stripping of stars or globular clusters due to harassment, as these components are safely embedded deep within their dark matter halo. We demonstrate that this result is actually consistent with an earlier study of harassment of dwarf galaxies, despite the apparent contradiction. Those few dwarf models that do suffer stellar stripping are found out to the virial radius of the cluster at redshift = 0, which mixes them in with less strongly harassed galaxies. However when placed on phase-space diagrams, strongly harassed galaxies are found offset to lower velocities compared to weakly harassed galaxies. This remains true in a cosmological simulation, even when haloes have a wide range of masses and concentrations. Thus phase-space diagrams may be a useful tool for determining the relative likelihood that galaxies have been strongly or weakly harassed.
Background and Objective
Although overexpression of the nuclear factor κB inhibitory and ubiquitin‐editing enzyme A20 is thought to be involved in the pathogenesis of inflammatory diseases, its ...function in periodontal disease remains unknown. The aims of the present study were to evaluate A20 expression in patients with periodontitis and to study the effects of A20 overexpression, using a recombinant adenovirus encoding A20 (Ad‐A20), on the inflammatory response and on osteoclastic differentiation in lipopolysaccharide (LPS)‐ and nicotine‐stimulated human periodontal ligament cells (hPDLCs).
Material and Methods
The concentration of prostaglandin E2 was measured by radioimmunoassay. Reverse transcription–polymerase chain reactions and western blot analyses were used to measure mRNA and protein levels, respectively. Osteoclastic differentiation was assessed in mouse bone marrow‐derived macrophages using conditioned medium from LPS‐ and nicotine‐treated hPDLCs.
Results
A20 was upregulated in the gingival tissues and neutrophils from patients with periodontitis and in LPS‐ and nicotine‐exposed hPDLCs. Pretreatment with A20 overexpression by Ad‐A20 markedly attenuated LPS‐ and nicotine‐induced production of prostaglandin E2, as well as expression of cyclooxygenase‐2 and proinflammatory cytokines. Moreover, A20 overexpression inhibited the number and size of tartrate‐resistant acid phosphatase‐stained osteoclasts, and downregulated osteoclast‐specific gene expression. LPS‐ and nicotine‐induced p38 phosphorylation and nuclear factor κB activation were blocked by Ad‐A20. Ad‐A20 inhibited the effects of nicotine and LPS on the activation of pan‐protein kinase C, Akt, GSK‐3β and protein kinase Cα.
Conclusions
This study is the first to demonstrate that A20 overexpression has anti‐inflammatory effects and blocks osteoclastic differentiation in a nicotine‐ and LPS‐stimulated hPDLC model. Thus, A20 overexpression may be a potential therapeutic target in inflammatory bone loss diseases, such as periodontal disease.
Academic departments universally communicate information about their programs using static websites. In addition to websites, some programs have even ventured out into social media (SM). These ...bidirectional forms of SM interaction show great promise; even hosting a live Question and Answer (Q&A) session has the potential for program branding. Artificial Intelligence (AI) usage in the form of a chatbot has expanded on websites and in SM. The potential use of chatbots, for the purposes of trainee recruitment, is novel and underutilized. With this pilot study, we aimed to answer the question; can the use of an Artificially Intelligent Chatbot and a Virtual Question-and-Answer Session aid in recruitment in a Post-COVID-19 era?
We held three structured Question-and-Answer Sessions over a period of 2 weeks. This preliminary study was performed after completion of the three Q&A sessions, in March-May, 2021. All 258 applicants to the pain fellowship program were invited via email to participate in the survey after attending one of the Q&A sessions. A 16-item survey assessing participants' perception of the chatbot was administered.
Forty-eight pain fellowship applicants completed the survey, for an average response rate of 18.6%. In all, 35 (73%) of survey respondents had used the website chatbot, and 84% indicated that it had found them the information they were seeking.
We employed an artificially intelligent chatbot on the department website to engage in a bidirectional exchange with users to adapt to changes brought on by the pandemic. SM engagement via chatbot and Q&A sessions can leave a favorable impression and improve the perception of a program.
Following our study on the incidence, morphology and kinematics of the ionized gas in early-type galaxies, we now address the question of what is powering the observed nebular emission. To constrain ...the likely sources of gas excitation, we resort to a variety of ancillary data we draw from complementary information on the gas kinematics, stellar populations and galactic potential from the sauron data, and use the sauron-specific diagnostic diagram juxtaposing the O iiiλ5007/Hβ and N iλλ5197, 5200/Hβ line ratios. We find a tight correlation between the stellar surface brightness and the flux of the Hβ recombination line across our sample, which points to a diffuse and old stellar source as the main contributor of ionizing photons in early-type galaxies, with post-asymptotic giant branch (pAGB) stars being still the best candidate based on ionizing balance arguments. The role of AGN photoionization is confined to the central 2–3 arcsec of an handful of objects with radio or X-ray cores. OB-stars are the dominant source of photoionization in 10 per cent of the sauron sample, whereas for another 10 per cent the intense and highly ionized emission is powered by the pAGB population associated to a recently formed stellar subcomponent. Fast shocks are not an important source of ionization for the diffuse nebular emission of early-type galaxies since the required shock velocities can hardly be attained in the potential of our sample galaxies. Finally, in the most massive and slowly or non-rotating galaxies in our sample, which can retain a massive X-ray halo, the finding of a spatial correlation between the hot and warm phases of the interstellar medium (ISM) suggests that the interaction with the hot ISM provides an additional source of ionization besides old ultraviolet-bright stars. This is also supported by a distinct pattern towards lower values of the O iii/Hβ ratio. These results lead us to investigate the relative role of stellar and AGN photoionization in explaining the ionized gas emission observed in early-type galaxies by the Sloan Digital Sky Survey (SDSS). By simulating how our sample galaxies would appear if placed at further distance and targeted by the SDSS, we conclude that only in very few, if any, of the SDSS galaxies which display modest values for the equivalent width of the O iii line (less than ∼2.4 Å) and low-ionization nuclear emission-line region like O iii/Hβ values the nebular emission is truly powered by an AGN.
We use GALEX near-UV (NUV) photometry of a sample of early-type galaxies selected in the SDSS (Sloan Digital Sky Survey) to study the UV color-magnitude relation (CMR). NUV - r color is an excellent ...tracer of even small amounts ( similar to 1% mass fraction) of recent ( unk1 Gyr) star formation, and so the NUV - r CMR allows us to study the effect of environment on the recent star formation history. We analyze a volume-limited sample of 839 visually inspected early-type galaxies in the redshift range 0.05 < z < 0.10 brighter than M sub(r) of -21.5 with any possible emission-line or radio-selected active galactic nuclei (AGNs) removed to avoid contamination. We find that contamination by AGN candidates and late-type interlopers highly bias any study of recent star formation in early-type galaxies and that, after removing those, our lower limit to the fraction of massive early-type galaxies showing signs of recent star formation is roughly 30% plus or minus 3%. This suggests that residual star formation is common even among the present day early-type galaxy population. We find that the fraction of UV-bright early-type galaxies is 25% higher in low-density environments. However, the density effect is clear only in the lowest density bin. The blue galaxy fraction for the subsample of the brightest early-type galaxies, however, shows a very strong density dependence, in the sense that the blue galaxy fraction is lower in a higher density region.
The traditional view of the morphology-spin connection is being challenged by recent integral field unit observations, as the majority of early-type galaxies are found to have a rotational component ...that is often as large as a dispersion component. Mergers are often suspected to be critical in galaxy spin evolution, yet the details of their roles are still unclear. We present the first results on the spin evolution of galaxies in cluster environments through a cosmological hydrodynamic simulation. Galaxies spin down globally with cosmic evolution. Major (mass ratios > 1/4) and minor (1/4 mass ratios > 1/50) mergers are important contributors to the spin-down in particular in massive galaxies. Minor mergers appear to have stronger cumulative effects than major mergers. Surprisingly, the dominant driver of galaxy spin-down seems to be environmental effects rather than mergers. However, since multiple processes act in combination, it is difficult to separate their individual roles. We briefly discuss the caveats and future studies that are called for.
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