Abstract
In this paper, we describe the routine photometric calibration of data taken with the VISTA infrared camera (VIRCAM) instrument on the ESO Visible and Infrared Survey Telescope for Astronomy ...(VISTA) telescope. The broad-band ZYJHKs data are directly calibrated from Two Micron all Sky Survey (2MASS) point sources visible in every VISTA image. We present the empirical transformations between the 2MASS and VISTA, and Wide-Field Camera and VISTA, photometric systems for regions of low reddening. We investigate the long-term performance of VISTA+VIRCAM. An investigation of the dependence of the photometric calibration on interstellar reddening leads to these conclusions: (1) For all broad-band filters, a linear colour-dependent correction compensates the gross effects of reddening where E(B − V) < 5.0. (2) For Z and Y, there is a significantly larger scatter above E(B − V) = 5.0, and insufficient measurements to adequately constrain the relation beyond this value. (3) The JHKs filters can be corrected to a few per cent up to E(B − V) = 10.0. We analyse spatial systematics over month-long time-scales, both inter- and intradetector and show that these are present only at very low levels in VISTA. We monitor and remove residual detector-to-detector offsets. We compare the calibration of the main pipeline products: pawprints and tiles. We show how variable seeing and transparency affect the final calibration accuracy of VISTA tiles, and discuss a technique, grouting, for mitigating these effects. Comparison between repeated reference fields is used to demonstrate that the VISTA photometry is precise to better than ≃ 2 per cent for the YJHKs bands and 3 per cent for the Z bands. Finally, we present empirically determined offsets to transform VISTA magnitudes into a true Vega system.
ABSTRACT Based on new near-infrared spectroscopic data from the instrument Espectrógrafo Multiobjeto Infra-Rojo (EMIR) on the 10.4 m Gran Telescopio Canarias, we report the presence of an ionized and ...warm molecular outflow in the luminous type-2 quasar J150904.22+043441.8 (z = 0.1118). The ionized outflow is faster than its molecular counterpart, although the outflow sizes that we derive for them are consistent within the errors (1.34 ± 0.18 and 1.46 ± 0.20 kpc, respectively). We use these radii, the broad emission-line luminosities and in the case of the ionized outflow, the density calculated from the trans-auroral O ii and S ii lines, to derive mass outflow rates and kinetic coupling efficiencies. While the ionized and warm molecular outflows represent a small fraction of the AGN power (≤0.033 and 0.0001 per cent of Lbol, respectively), the total molecular outflow, whose mass is estimated from an assumed warm-to-cold gas mass ratio of 6 × 10−5, has a kinetic coupling efficiency of ∼1.7 per cent Lbol. Despite the large uncertainty, this molecular outflow represents a significant fraction ofLbol and it could potentially have a significant impact on the host galaxy. In addition, the quasar spectrum reveals bright and patchy narrow Paα emission extending out to 4 arcsec (8 kpc) south-east and north-west from the active nucleus.
Summary
Background
Suboptimal response to ursodeoxycholic acid occurs in 40% of primary biliary cholangitis (PBC) patients, affecting survival. Achieving a deep response (normalisation of alkaline ...phosphatase ALP and bilirubin ≤0.6 upper limit of normal) improves survival. Yet, the long‐term effectiveness of second‐line treatments remains uncertain.
Aims
To evaluate the long‐term effectiveness of obeticholic acid (OCA) ± fibrates. Focusing on biochemical response (ALP ≤1.67 times the upper limit of normal, with a decrease of at least 15% from baseline and normal bilirubin levels), normalisation of ALP, deep response and biochemical remission (deep response plus aminotransferase normalisation).
Methods
We conducted a longitudinal, observational, multicentre study involving ursodeoxyccholic acid non‐responsive PBC patients (Paris‐II criteria) from Spain and Portugal who received OCA ± fibrates.
Results
Of 255 patients, median follow‐up was 35.1 months (IQR: 20.2–53). The biochemical response in the whole cohort was 47.2%, 61.4% and 68.6% at 12, 24 and 36 months. GLOBE‐PBC and 5‐year UK‐PBC scores improved (p < 0.001). Triple therapy (ursodeoxycholic acid plus OCA plus fibrates) had significantly higher response rates than dual therapy (p = 0.001), including ALP normalisation, deep response and biochemical remission (p < 0.001). In multivariate analysis, triple therapy remained independently associated with biochemical response (p = 0.024), alkaline phosphatase normalisation, deep response and biochemical remission (p < 0.001). Adverse effects occurred in 41.2% of cases, leading to 18.8% discontinuing OCA. Out of 55 patients with cirrhosis, 12 developed decompensation. All with baseline portal hypertension.
Conclusion
Triple therapy was superior in achieving therapeutic goals in UDCA‐nonresponsive PBC. Decompensation was linked to pre‐existing portal hypertension.
Longitudinal, real‐world study on 255 UDCA‐nonresponsive PBC patients (Per Paris II criteria); median follow‐up of 35.1 months (IQR: 20–53). All patients received obeticholic acid (OCA), with 25% receiving later add‐on fibrate treatment (triple therapy). In multivariate analysis, triple therapy outperformed dual therapy across all surrogate biochemical endpoints of outcomes.
Environmental niche modeling (ENM) is commonly used to develop probabilistic maps of species distribution. Among available ENM techniques, MaxEnt has become one of the most popular tools for modeling ...species distribution, with hundreds of peer-reviewed articles published each year. MaxEnt's popularity is mainly due to the use of a graphical interface and automatic parameter configuration capabilities. However, recent studies have shown that using the default automatic configuration may not be always appropriate because it can produce non-optimal models; particularly when dealing with a small number of species presence points. Thus, the recommendation is to evaluate the best potential combination of parameters (feature classes and regularization multiplier) to select the most appropriate model. In this work we reviewed 244 articles published between 2013 and 2015 to assess whether researchers are following recommendations to avoid using the default parameter configuration when dealing with small sample sizes, or if they are using MaxEnt as a "black box tool." Our results show that in only 16% of analyzed articles authors evaluated best feature classes, in 6.9% evaluated best regularization multipliers, and in a meager 3.7% evaluated simultaneously both parameters before producing the definitive distribution model. We analyzed 20 articles to quantify the potential differences in resulting outputs when using software default parameters instead of the alternative best model. Results from our analysis reveal important differences between the use of default parameters and the best model approach, especially in the total area identified as suitable for the assessed species and the specific areas that are identified as suitable by both modelling approaches. These results are worrying, because publications are potentially reporting over-complex or over-simplistic models that can undermine the applicability of their results. Of particular importance are studies used to inform policy making. Therefore, researchers, practitioners, reviewers and editors need to be very judicious when dealing with MaxEnt, particularly when the modelling process is based on small sample sizes.
The historic first joint detection of both gravitational-wave and electromagnetic emission from a binary neutron star merger cemented the association between short gamma-ray bursts (SGRBs) and ...compact object mergers, as well as providing a well-sampled multi-wavelength light curve of a radioactive kilonova (KN) for the first time. Here, we compare the optical and near-infrared light curves of this KN, AT 2017gfo, to the counterparts of a sample of nearby (z < 0.5) SGRBs to characterize their diversity in terms of their brightness distribution. Although at similar epochs AT 2017gfo appears fainter than every SGRB-associated KN claimed so far, we find three bursts (GRBs 050509B, 061201, and 080905A) where, if the reported redshifts are correct, deep upper limits rule out the presence of a KN similar to AT 2017gfo by several magnitudes. Combined with the properties of previously claimed KNe in SGRBs this suggests considerable diversity in the properties of KN drawn from compact object mergers, despite the similar physical conditions that are expected in many NS-NS mergers. We find that observer angle alone is not able to explain this diversity, which is likely a product of the merger type (NS-NS versus NS-BH) and the detailed properties of the binary (mass ratio, spins etc.). Ultimately disentangling these properties should be possible through observations of SGRBs and gravitational-wave sources, providing direct measurements of heavy element enrichment throughout the universe.
We report the discovery and monitoring of the near-infrared counterpart (AT2017gfo) of a binary neutron-star merger event detected as a gravitational wave source by Advanced Laser Interferometer ...Gravitational-wave Observatory (LIGO)/Virgo (GW170817) and as a short gamma-ray burst by Fermi Gamma-ray Burst Monitor (GBM) and Integral SPI-ACS (GRB 170817A). The evolution of the transient light is consistent with predictions for the behavior of a "kilonova/macronova" powered by the radioactive decay of massive neutron-rich nuclides created via r-process nucleosynthesis in the neutron-star ejecta. In particular, evidence for this scenario is found from broad features seen in Hubble Space Telescope infrared spectroscopy, similar to those predicted for lanthanide-dominated ejecta, and the much slower evolution in the near-infrared K s -band compared to the optical. This indicates that the late-time light is dominated by high-opacity lanthanide-rich ejecta, suggesting nucleosynthesis to the third r-process peak (atomic masses A 195 ). This discovery confirms that neutron-star mergers produce kilo-/macronovae and that they are at least a major-if not the dominant-site of rapid neutron capture nucleosynthesis in the universe.
Bisphenol A (BPA) is an endocrine disruptor whose ubiquitous presence in the environment has been related with impairment of male reproduction. BPA can cause both transcriptomic and epigenetic ...changes during spermatogenesis. To evaluate the potential effects of male exposure to BPA, adult zebrafish males were exposed during spermatogenesis to doses of 100 and 2000 μg/L, which were reported in contaminated water bodies and higher than those allowed for human consumption. Fertilization capacity and survival at hatching were analysed after mating with untreated females. Spermatogenic progress was analysed through a morphometrical study of testes and apoptosis was evaluated by TUNEL assay. Testicular gene expression was evaluated by RT-qPCR and epigenetics by using ELISA and immunocytochemistry. In vitro studies were performed to investigate the role of Gper. Chromatin fragmentation and the presence of transcripts were also evaluated in ejaculated sperm. Results on testes from males treated with the highest dose showed a significant decrease in spermatocytes, an increase in apoptosis, a downregulation of ccnb1 and sycp3, all of which point to an alteration of spermatogenesis and to meiotic arrest and an upregulation of gper1 and esrrga receptors. Additionally, BPA at 2000 μg/L caused missregulation of epigenetic remodelling enzymes transcripts in testes and promoted DNA hypermethylation and H3K27me3 demethylation. BPA also triggered an increase in histone acetyltransferase activity, which led to hyperacetylation of histones (H3K9ac, H3K14ac, H4K12ac). In vitro reversion of histone acetylation changes using a specific GPER antagonist, G-36, suggested this receptor as mediator of histone hyperacetylation. Males treated with the lower dose only showed an increase in some histone acetylation marks (H3K14ac, H4K12ac) but their progeny displayed very limited survival at hatching, revealing the deleterious effects of unbalanced paternal epigenetic information. Furthermore, the highest dose of BPA led to chromatin fragmentation, promoting direct reproductive effects, which are incompatible with embryo development.
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•BPA male exposure during spermatogenesis induces apoptosis and impairs meiotic progress.•Gene expression of testicular cells is missregulated by BPA exposure.•Histone hyperacetylation and DNA hypermethylation is promoted by BPA in testicle.•Sperm epigenetic information is also modified by environmental-relevant BPA doses.
Male BPA exposure impairs spermatogenesis and alters the epigenetic pattern of testicular cells, leading to hyperacetylation of histones and DNA hypermethylation, which can promote adverse effects on the zygote upon fertilization.
Remineralization of caries lesions is naturally achieved by salivary ions, and it can be enhanced by external factors or elements such as fluoride. Numerous studies have demonstrated the ...remineralizing efficacy of fluoride therapies as well as the limitations with some groups of the population. Consequently, developing new remineralization therapies to close this gap in efficacy has been a priority for the last 2 decades. In this review, we summarize and briefly discuss some of the latest advances in remineralization therapies. Most new therapies try to enhance the effect of fluoride by adding other potentially active ingredients to the formulation, such as calcium, phosphate, stannous, xylitol, and arginine. Other remineralization strategies have focused on creating remineralizing scaffolds within the lesions (e.g., self-assembling peptides). While several of the new remineralization strategies have progressed significantly in recent years, for most of them, the evidence is still insufficient to assess their true clinical potential.
Autophagy is a process that maintains homeostasis during stress, although it also contributes to cell death under specific contexts. Ceramides have emerged as important effectors in the regulation of ...autophagy, mediating the crosstalk with apoptosis. Melatonin induces apoptosis of cancer cells; however, its role in autophagy and ceramide metabolism has yet to be clearly elucidated. This study was aimed to evaluate the effect of melatonin administration on autophagy and ceramide metabolism and its possible link with melatonin‐induced apoptotic cell death in hepatocarcinoma (HCC) cells. Melatonin (2 mm) transiently induced autophagy in HepG2 cells through JNK phosphorylation, characterized by increased Beclin‐1 expression, p62 degradation, and LC3II and LAMP‐2 colocalization, which translated in decreased cell viability. Moreover, ATG5 silencing sensitized HepG2 cells to melatonin‐induced apoptosis, suggesting a dual role of autophagy in cell death. Melatonin enhanced ceramide levels through both de novo synthesis and acid sphingomyelinase (ASMase) stimulation. Serine palmitoyltransferase (SPT) inhibition with myriocin prevented melatonin‐induced autophagy and ASMase inhibition with imipramine‐impaired autophagy flux. However, ASMase inhibition partially protected HepG2 cells against melatonin, while SPT inhibition significantly enhanced cell death. Findings suggest a crosstalk between SPT‐mediated ceramide generation and autophagy in protecting against melatonin, while specific ASMase‐induced ceramide production participates in melatonin‐mediated cell death. Thus, dual blocking of SPT and autophagy emerges as a potential strategy to potentiate the apoptotic effects of melatonin in liver cancer cells.
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