Miracle-dz/UniFAR-FTUs huggingface dataset:
More about stable wormholes in beyond Horndeski theory

It is known that Horndeski theories, like many other scalar-tensor gravities, do not support static, spherically symmetric wormholes: they always have either ghosts or gradient instabilities among parity-even linearized perturbations. Here we address the issue of whether or not this no-go theorem is valid in ‘beyond Horndeski’ theories. We derive, in the latter class of theories, the conditions for the absence of ghost and gradient instabilities for non-spherical parity even perturbations propagating in radial direction. We find, in agreement with existing arguments, that the proof of the above no-go theorem does not go through beyond Horndeski. We also obtain conditions ensuring the absence of ghosts and gradient instabilities for all parity odd modes. We give an example of beyond Horndeski Lagrangian which admits a wormhole solution obeying our (incomplete set of) stability conditions. Even though our stability analysis is incomplete, as we do not consider spherically symmetric parity even modes and parity even perturbations propagating in angular directions, as well as ‘slow’ tachyonic instabilities, our findings indicate that beyond Horndeski theories may be viable candidates to support traversable wormholes.
GASP. XV. A MUSE view of extreme ram-pressure stripping along the line of sight: physical properties of the jellyfish galaxy JO201

We present a study of the physical properties of JO201, a unique disk galaxy with extended tails undergoing extreme ram-pressure stripping as it moves through the massive cluster Abell 85 at supersonic speeds mostly along the line of sight. JO201 was observed with MUSE as part of the GASP programme. In a previous paper (GASP II) we studied the stellar and gas kinematics. In this paper we present emission-line ratios, gas-phase metallicities and ages of the stellar populations across the galaxy disk and tails. We find that while the emission at the core of the galaxy is dominated by an active galactic nucleus (AGN), the disk is composed of star-forming knots surrounded by excited diffuse gas. The collection of star-forming knots presents a metallicity gradient steadily decreasing from the centre of the galaxy outwards, and the ages of the stars across the galaxy show that the tails formed <10^9 yr ago. This result is consistent with an estimate of the stripping timescale (1 Gyr), obtained from a toy orbital model. Overall, our results independently and consistently support a scenario in which a recent or ongoing event of intense ram-pressure stripping acting from the outer disk inwards, causes removal and compression of gas, thus altering the AGN and star-formation activity within and around the galaxy.
A dynamical model for gas flows, star formation and nuclear winds in galactic centres

We present a dynamical model for gas transport, star formation, and winds in the nuclear regions of galaxies, focusing on the Milky Way's Central Molecular Zone (CMZ). In our model angular momentum and mass are transported by a combination of gravitational and bar-driven acoustic instabilities. In gravitationally-unstable regions the gas can form stars, and the resulting feedback drives both turbulence and a wind that ejects mass from the CMZ. We show that the CMZ is in a quasi-steady state where mass deposited at large radii by the bar is transported inward to a star-forming, ring-shaped region at $\sim 100$ pc from the Galactic Centre, where the shear reaches a minimum. This ring undergoes episodic starbursts, with bursts lasting $\sim 5-10$ Myr occurring at $\sim 20-40$ Myr intervals. During quiescence the gas in the ring is not fully cleared, but is driven out of a self-gravitating state by the momentum injected by expanding supernova remnants. Starbursts also drive a wind off the star-forming ring, with a time-averaged mass flux comparable to the star formation rate. We show that our model agrees well with the observed properties of the CMZ, and places it near a star formation minimum within the evolutionary cycle. We argue that such cycles of bursty star formation and winds should be ubiquitous in the nuclei of barred spiral galaxies, and show that the resulting distribution of galactic nuclei on the Kennicutt-Schmidt relation is in good agreement with that observed in nearby galaxies.
High School Teachers’ Subject and Pedagogical Content Knowledge of Mathematics in the Khomas Education Region, Namibia

This paper reports on a study that explored the subject and pedagogical content knowledge displayed by high school mathematics teachers in the Khomas education region in Namibia. The study was based on a quantitative approach using a survey design. A stratified random sampling method was used to select the participants in all the four school circuits in the region. The study population consisted of 79 Grade 12 mathematics teachers from public schools. A sample of 40 mathematics teachers took part in the study, completed a questionnaire and wrote a test. A Microsoft Excel spreadsheet was used to sort the data and produce graphs and tables. A paired t-test was also used to determine if a significant difference existed between the participants’ subject content knowledge (mathematical knowledge in our context, (MCK) and pedagogical content knowledge (PCK). The findings revealed that the participants had some deficiencies on MCK topics such as quadratic equations, angles properties and numbers. They also portrayed weak PCK on fractions, simultaneous and linear equations. This shows that a significant difference exists between the teachers’ MCK and PCK with t calculated = 11.092 greater than the t critical (between 2.712 and 2.704) at a significance level, α = 0.01 but also that the participants’ MCK and PCK were moderately and positively correlated (r = 0.681, p < 0.01). This study recommends that mathematics teachers in the Khomas region be provided frequently with in-service training to strengthen their shortcomings regarding MCK and PCK (knowledge of mathematics tasks, knowledge of learners’ misconceptions and difficulties, and knowledge of mathematics instructions). We also recommend further studies to determine how high school mathematics teachers’ knowledge can impact learners’ academic performance in other education regions in Namibia.
Chemistry and radiative shielding in star-forming galactic discs

To understand the conditions under which dense, molecular gas is able to form within a galaxy, we post-process a series of three-dimensional galactic-disk-scale simulations with ray-tracing based radiative transfer and chemical network integration to compute the equilibrium chemical and thermal state of the gas. In performing these simulations we vary a number of parameters, such as the ISRF strength, vertical scale height of stellar sources, cosmic ray flux, to gauge the sensitivity of our results to these variations. Self-shielding permits significant molecular hydrogen (H2) abundances in dense filaments around the disk midplane, accounting for approximately ~10-15% of the total gas mass. Significant CO fractions only form in the densest, n>~10^3 cm^-3, gas where a combination of dust, H2, and self-shielding attenuate the FUV background. We additionally compare these ray-tracing based solutions to photochemistry with complementary models where photo-shielding is accounted for with locally computed prescriptions. With some exceptions, these local models for the radiative shielding length perform reasonably well at reproducing the distribution and amount of molecular gas as compared with a detailed, global ray tracing calculation. Specifically, an approach based on the Jeans Length with a T=40K temperature cap performs the best in regards to a number of different quantitative measures based on the H2 and CO abundances.
Echocardiographic Evaluation of the Cardiac Chambers in Asthmatic Patients: The BADA (Blood Pressure Levels, Clinical Features and Markers of Subclinical Cardiovascular Damage of Asthma Patients) Study-ECO

The “Blood pressure levels, clinical features and markers of subclinical cardiovascular Damage of Asthma patients” (BADA) study is aimed at defining the cardiovascular risk profile and the markers of subclinical and clinical vascular and cardiac damage in asthmatic patients. Very few studies have assessed asthmatic patients without concomitant heart disease through a transthoracic echocardiogram. The goal of the present study is to investigate the prevalence of morphology and/or function changes in the cardiac chambers of a sample of 86 patients with chronic asthma, referred to the dedicated outpatient unit of the Division of Respiratory Diseases of the AOUP “P. Giaccone” of the University of Palermo, and the results obtained were compared with those of a control group without respiratory or cardiovascular diseases. Patients with asthma showed a marked and widespread involvement of the four cardiac chambers compared with the controls: enlargement of the two atria, greater left ventricular remodeling with interventricular septal thickening, increased indexed left ventricular mass with a significantly greater percentage of patients with overt left ventricular hypertrophy, worse left ventricular diastolic function proven by the significant difference in the E/A ratio, and worse right ventricular systolic function with global right ventricular dysfunction estimated by the Myocardial Performance Index (Tei Index). Multivariate regression analysis, after adjustment for essential hypertension, hypertension severity, diabetes, Body Mass Index, and creatinine clearance, seems to indicate that the indexed left ventricular mass, right atrial volume, and right ventricular Tei index (but not left ventricular hypertrophy) correlate significantly with asthma, severe asthma, and FEV1 (and to a lesser extent with asthma duration). No correlation is apparent between inhaled therapy (ICS, SABA) and myocardial involvement. These results seem to confirm that a more in-depth cardiovascular evaluation in patients with chronic respiratory disease allows the identification of unrecognized cardiovascular involvement. A transthoracic echocardiogram performed in asthmatic patients without clinically overt signs or symptoms of cardiovascular impairment has identified some features indicative of an early subclinical cardiac impairment not found in the control group. These findings, considering also the higher frequency of hypertension in the asthma group, deserve further validation in the future.
Spectroscopic view on the outburst activity of the symbiotic binary AG Draconis

Variations of the emission lines in the spectrum of the yellow symbiotic star AG Dra have been studied for over 14 years (1997 - 2011), using more than 500 spectra obtained on the 1.5-metre telescope at Tartu Observatory, Estonia. The time interval covered includes the major (cool) outburst of AG Dra that started in 2006. Main findings can be summarized as follows: (i) cool and hot outbursts of AG Dra can be distinguished from the variations of optical emission lines; (ii) the Raman scattered emission line of O VI at $\lambda\,6825$ almost disappeared during the cool outburst; (iii) lower excitation emission lines did not change significantly during the cool outburst, but they vary in hot outbursts and also follow orbital motion; (iv) similarity of variations in AG Dra to those in the prototypical symbiotic star Z And allows to suggest that a "combination nova" model proposed for the latter object might also be responsible for the outburst behaviour of AG Dra.
FXR mediated bile acid signal to advance the study of cirrhosis of the liver regeneration

To explore the mechanism of FXR mediated bile acid signal to cirrhosis of the liver regeneration. The total sample size of 75 male SD rats were randomly divided equally into 3 groups i.e., 25 samples in each group. The three groups were cholic acid deficiency group, cholic acid load group and control group. Cholic acid load group of forage feed 0.2% cholic acid, cholic acid deficiency group feeding to enamine with 2%, the control to the fed standard feed. Liver body ratio, AST, and ALT, HGF levels, liver specimens, protein levels of There were no significant differences in ALT, AST and HGF levels among the three groups at the end of surgery (P>0.05), but from the 3rd day after surgery, ALT, and AST levels in the cholic acid-deficient group were higher than those in the cholic acid-loaded group and the control group, while HGF levels were lower than those in the cholic acid-loaded group and the control group (P<0.05).
Identification of Hypoxia-Related Prognostic Signature and Competing Endogenous RNA Regulatory Axes in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a common type of liver cancer and one of the highly lethal diseases worldwide. Hypoxia plays an important role in the development and prognosis of HCC. This study aimed to construct a new hypoxia-related prognosis signature and investigate its potential ceRNA axes in HCC. RNA profiles and hypoxia genes were downloaded, respectively, from the Cancer Genome Atlas hepatocellular carcinoma database and Gene Set Enrichment Analysis website. Cox regression analyses were performed to select the prognostic genes and construct the risk model. The ENCORI database was applied to build the lncRNA-miRNA–mRNA prognosis-related network. The TIMER and CellMiner databases were employed to analyze the association of gene expression in ceRNA with immune infiltration and drug sensitivity, respectively. Finally, the co-expression analysis was carried out to construct the potential lncRNA/miRNA/mRNA regulatory axes. We obtained a prognostic signature including eight hypoxia genes (ENO2, KDELR3, PFKP, SLC2A1, PGF, PPFIA4, SAP30, and TKTL1) and further established a hypoxia-related prognostic ceRNA network including 17 lncRNAs, six miRNAs, and seven mRNAs for hepatocellular carcinoma. Then, the analysis of immune infiltration and drug sensitivity showed that gene expression in the ceRNA network was significantly correlated with the infiltration abundance of multiple immune cells, the expression level of immune checkpoints, and drug sensitivity. Finally, we identified three ceRNA regulatory axes (SNHG1/miR-101-3p/PPFIA4, SNHG1/miR-101-3p/SAP30, and SNHG1/miR-101-3p/TKTL1) associated with the progression of HCC under hypoxia. Here, we constructed a prognosis gene signature and a ceRNA network related to hypoxia for hepatocellular carcinoma. Among the ceRNA network, six highly expressed lncRNAs (AC005540.1, AC012146.1, AC073529.1, AC090772.3, AC138150.2, AL390728.6) and one highly expressed mRNA (PPFIA4) were the potential biomarkers of hepatocellular carcinoma which we firstly reported. The three predicted hypoxia-related regulatory axes may play a vital role in the progression of hepatocellular carcinoma.
The Astrometric Foundation of Astrophysics

Astrophysical studies require a knowledge of very accurate positions, motions and distances of stars. A brief overview is given of the significance and development of astrometry by ESA's two astrometric satellites, Hipparcos and Gaia, launched in respectively 1989 and 2013. The astrometric foundation of all branches of astronomy from the solar system and stellar systems to compact galaxies, quasars and dark matter is being revolutionized by the observations from these satellites. The future of fundamental astrometry must be considered in a time frame of 50 years, therefore science issues for a Gaia successor mission in twenty years are discussed in an extensive report: "Absolute astrometry in the next 50 years" available at this http URL
Discerning dark energy models with high redshift standard candles

Following the success of type Ia supernovae in constraining cosmologies at lower redshift $(z\lesssim2)$, effort has been spent determining if a similarly useful standardisable candle can be found at higher redshift. {In this work we determine the largest possible magnitude discrepancy between a constant dark energy $\Lambda$CDM cosmology and a cosmology in which the equation of state $w(z)$ of dark energy is a function of redshift for high redshift standard candles $(z\gtrsim2)$}. We discuss a number of popular parametrisations of $w(z)$ with two free parameters, $w_z$CDM cosmologies, including the Chevallier-Polarski-Linder and generalisation thereof, $n$CPL, as well as the Jassal-Bagla-Padmanabhan parametrisation. For each of these parametrisations we calculate and find extrema of $\Delta \mu$, the difference between the distance modulus of a $w_z$CDM cosmology and a fiducial $\Lambda$CDM cosmology as a function of redshift, given 68\% likelihood constraints on the parameters $P=(\Omega_{m,0}, w_0, w_a)$. The parameters are constrained using cosmic microwave background, baryon acoustic oscillations, and type Ia supernovae data using CosmoMC. We find that none of the tested cosmologies can deviate more than 0.05 mag from the fiducial $\Lambda$CDM cosmology at high redshift, implying that high redshift standard candles will not aid in discerning between a $w_z$CDM cosmology and the fiducial $\Lambda$CDM cosmology. Conversely, this implies that if high redshift standard candles are found to be in disagreement with $\Lambda$CDM at high redshift, then this is a problem not only for $\Lambda$CDM but for the entire family of $w_z$CDM cosmologies.
The physical properties of galaxies with unusually red mid-infrared colours

The goal of this paper is to investigate the physical nature of galaxies in the redshift range $0.02<z<0.15$ that have strong excess emission at mid-IR wavelengths and to determine whether they host a population of accreting black holes that cannot be identified using optical emission lines. We show that at fixed stellar mass $M_*$ and $D_n(4000)$, the distribution of [3.4]-[4.6] $\mu$m (WISE W1-W2 band) colours is sharply peaked, with a long tail to much redder W1-W2 colours. We introduce a procedure to pull out the red outlier population based on a combination of three stellar population diagnostics. When compared with optically-selected AGN, red outliers are more likely to be found in massive galaxies, and they tend to have lower stellar mass densities, younger stellar ages and higher dust content than optically-selected AGN hosts. They are twice as likely to be detected at radio wavelengths. We examine W1-W2 colour profiles for a subset of the nearest, reddest outliers and find that most are not centrally peaked, indicating that the hot dust emission is spread throughout the galaxy. We find that radio luminosity is the quantity that is most predictive of a redder central W1-W2 colour. Radio-loud galaxies with centrally concentrated hot dust emission are almost always morphologically disturbed, with compact, unresolved emission at 1.4 Ghz. Eighty percent of such systems are identifiable as AGN using optical emission line diagnostics.
Exploring the RNA Editing Events and Their Potential Regulatory Roles in Tea Plant (Camellia sinensis L.)

RNA editing is a post-transcriptional modification process that alters the RNA sequence relative to the genomic blueprint. In plant organelles (namely, mitochondria and chloroplasts), the most common type is C-to-U, and the absence of C-to-U RNA editing results in abnormal plant development, such as etiolation and albino leaves, aborted embryonic development and retarded seedling growth. Here, through PREP, RES-Scanner, PCR and RT-PCR analyses, 38 and 139 RNA editing sites were identified from the chloroplast and mitochondrial genomes of Camellia sinensis, respectively. Analysis of the base preference around the RNA editing sites showed that in the −1 position of the edited C had more frequent occurrences of T whereas rare occurrences of G. Three conserved motifs were identified at 25 bases upstream of the RNA editing site. Structural analyses indicated that the RNA secondary structure of 32 genes, protein secondary structure of 37 genes and the three-dimensional structure of 5 proteins were altered due to RNA editing. The editing level analysis of matK and ndhD in six tea cultivars indicated that matK-701 might be involved in the color change of tea leaves. Furthermore, 218 PLS-CsPPR proteins were predicted to interact with the identified RNA editing sites. In conclusion, this study provides comprehensive insight into RNA editing events, which will facilitate further study of the RNA editing phenomenon of the tea plant.
The distance and internal composition of the neutron star in EXO 0748-676 with XMM-Newton

Recently, the neutron star X-ray binary EXO 0748-676 underwent a transition to quiescence. We analysed an XMM-Newton observation of this source in quiescence, where we fitted the spectrum with two different neutron star atmosphere models. From the fits we constrained the allowed parameter space in the mass-radius diagram for this source for an assumed range of distances to the system. Comparing the results with different neutron star equations of state, we constrained the distance to EXO 0748-676. We found that strange quark matter equation of state is consistent with the mass and radius from our fits only if EXO 0748-676 is at a distance of less than 5 kpc, whereas the normal neutron star equation of state is consistent with our best-fitting mass and radius if the distance is similar to 7 kpc, as deduced from properties of the X-ray bursts.
Effects of baryon mass loss on profiles of large galactic dark matter haloes

We perform controlled numerical experiments to asses the effect of baryon mass loss on the inner structure of large galactic dark matter (DM) haloes. This mass expulsion is intended to mimic both the supernova and active galactic nucleus (AGN) feedbacks, as well as the evolution of stellar populations. This study is meant in particular for precursors of massive early-type galaxies (ETGs), wherein strong AGN feedback (often dubbed ‘quasi-stellar object mode’ in galaxy formation models) has been proposed to remove on a short time-scale, of the order of a few dynamical times, a substantial fraction of their baryons. In a previous paper we evaluated the observational consequences (size increase) of this process on the galactic structure. Here we focus on the distribution of DM in the galactic region. It is shown that the inner region of the DM halo expands and its density profile flattens by a sizeable amount, with little dependence on the expulsion time-scale. We also evaluate the effect of the commonly made approximation of treating the baryonic component as a potential that changes in intensity without any variation in shape. This approximation leads to some underestimates of the halo expansion and its slope flattening. We conclude that cuspy density profiles in ETGs could be difficult to reconcile with an effective AGN (or stellar) feedback during the evolution of these systems.