Wizeline, Zapopan

ITESO, A.C

VLT/SPHERE robust astrometry of the HR8799 planets at milliarcsecond-level accuracy Orbital architecture analysis with PyAstrOFit

HR8799 is orbited by at least four giant planets, making it a prime target for the recently commissioned Spectro-Polarimetric High-contrast Exoplanet REsearch (VLT/SPHERE). As such, it was observed on five consecutive nights during the SPHERE science verification in December 2014. We aim to take full advantage of the SPHERE capabilities to derive accurate astrometric measurements based on H-band images acquired with the Infra-Red Dual-band Imaging and Spectroscopy (IRDIS) subsystem, and to explore the ultimate astrometric performance of SPHERE in this observing mode. We also aim to present a detailed analysis of the orbital parameters for the four planets. We report the astrometric positions for epoch 2014.93 with an accuracy down to 2.0 mas, mainly limited by the astrometric calibration of IRDIS. For each planet, we derive the posterior probability density functions for the six Keplerian elements and identify sets of highly probable orbits. For planet d, there is clear evidence for nonzero eccentricity ($e \simeq 0.35$), without completely excluding solutions with smaller eccentricities. The three other planets are consistent with circular orbits, although their probability distributions spread beyond $e = 0.2$, and show a peak at $e \simeq 0.1$ for planet e. The four planets have consistent inclinations of about $30\deg$ with respect to the sky plane, but the confidence intervals for the longitude of ascending node are disjoint for planets b and c, and we find tentative evidence for non-coplanarity between planets b and c at the $2 \sigma$ level.Comment: 23 pages, 14 figure

Electrothermoplasmonic flow in gold nanoparticles suspensions: nonlinear dependence of flow velocity on aggregate concentration

Efficient mixing and pumping of liquids at the microscale is a technology that is still to be optimized. The combination of an AC electric field with a small temperature gradient leads to a strong electrothermal flow that can be used for multiple purposes. Combining simulations and experiments, an analysis of the performance of electrothermal flow is provided when the temperature gradient is generated by illuminating plasmonic nanoparticles in suspension with a near-resonance laser. Fluid flow is measured by tracking the velocity of fluorescent tracer microparticles in suspension as a function of the electric field, laser power, and concentration of plasmonic particles. Among other results, a non-linear relationship is found between the velocity of the fluid and particle concentration, which is justified in terms of multiple scattering-absorption events, involving aggregates of nanoparticles, that lead to enhanced absorption when the concentration is raised. Simulations provide a description of the phenomenon that is compatible with experiments and constitute a way to understand and estimate the absorption and scattering cross-sections of both dispersed particles and/or aggregates. A comparison of experiments and simulations suggests that there is some aggregation of the gold nanoparticles by forming clusters of about 2–7 particles, but no information about their structure can be obtained without further theoretical and experimental developments. This nonlinear behavior could be useful to get very high ETP velocities by inducing some controlled aggregation of the particles.This research has been supported by Consejería de Universidad, Investigación e Innovación de la Junta de Andalucía and FEDER, “Una manera de hacer Europa”/Projects P18-FR-3583 and FQM-410-UGR18, Ministerio de Ciencia, Innovación y Universidades through Project EQC2018-004693-P, and Grant PID2021-127427NB-I00/ MCIN/AEI/10.13039/501100011033/FEDER,UE. Funding for open access charge: Universidad de Málaga/CBUA

Forest plantations in Manabí (Ecuador): assessment of fragmentation and connectivity to support dry tropical forests conservation

In many tropical regions, national forests plantation programs have been promoted. Those plantations frequently contribute to habitat changes. However, the associated effects of forest plantations on habitat fragmentation and landscape connectivity are unclear. From 2008 to 2018, we examined land use changes, plantations, and deforestation of the Manabí province (Ecuador) provided by the Ecuadorian Ministry of the Environment. Four scenarios were created: (i) land uses in 2008, (ii) land uses in 2018, (iii) land uses in 2018 without deforestation, and iv) land uses in 2018 including reforestation. Fragmentation and connectivity metrics were analyzed using ArcGisPro and Graphad 2.6 software, respectively. Puma yagouaroundi was selected as the reference species. At regional scale, forest plantations had a significant effect on land uses changes and fragmentation during the study period. Forests decreased from 33.7% to 32.4% between 2008 and 2018, although other natural land uses, mostly those involving shrubs, increased by almost double (from 2.4% to 4.6%). Most of the deforestation affected native forests during this period, and most reforested areas in 2018 covered former agricultural land. Fragmentation decreased in the number of patches and increased in the average patch size. When considering reforestation, deforestation was higher than the reforested area (58 km2 of difference), increasing the number of patches but with smaller size. Reforestation increased connectivity with a higher number of links and distance, particularly in central and extreme northeast areas of Manabí province. The scenario without deforestation also increased connectivity for Puma yagouaroundi in the west part of the Manabí province. Our findings suggest that forest plantations contribute to forest conservation by increasing the connectivity between fragmented patches

A combined approach to assessing the conservation status of Cap des Trois Fourches as a potential MPA: is there a shortage of MPAs in the Southern Mediterranean?

The Mediterranean basin is recognized as one of the most diverse regions on the planet, but is being threatened by overexploitation and habitat loss. Furthermore, the Strait of Gibraltar and adjacent Alboran Sea have been identified as representing an important habitat for many threatened or endangered species. In this context, one vehicle for marine conservation is the creation of marine protected sites, although Mediterranean Marine Protected Areas (MPAs) are neither large nor representative enough to form an effective network of protection. An inventory of the benthic communities and habitats of conservation interest has been carried out in Cap des Trois Fourches, an ecological and biogeographical site of interest. Univariate and multivariate analyses showed differences for marine communities among habitats and localities, indicating a great diversity in marine assemblages but an absence of a spatial gradient in marine α-diversity. The Trois Fourches area showed a high environmental quality and hosted several endangered species. Habitats of conservation concern, such as marine caves, seagrass meadows and coralligenous assemblages, were detected and studied. The scientific data recorded provide sound support for the establishment of a new MPA in Trois Fourches, taking into account that the findings match the scientific criteria required for declaration as a protected area. The benefits for connectivity at the Mediterranean scale and the local economy are discussed

Arc Stability Characterization of Double Coated Electrodes for Hardfacing

The aim of this work is to establish the influence of the relative position of the alloy charge C-Cr-Mn in the structure of the coating of rutile electrodes for hardfacing, on the operational behavior (arc stability). For this, three variants of electrodes with similar chemical composition are elaborated in the metallic core and the coating, differentiating only in the relative position that occupies the alloy charge (C-Cr-Mn) in the structure of the coating: internal, external and homogeneous. For the development of the research, a completely random design is used. The operative characterization of the electrodes is performed in terms of the arc stability. In conclusion, it can be seen that the position of the alloy load influences the operation behavior (stability of the arc). The variant of internal alloy charge in the coating presents the better arc stability performance

SCORE and REGICOR function charts underestimate the cardiovascular risk in Spanish patients with rheumatoid arthritis

Introduction: Our objective was to determine which one of the two function charts available in Spain to calculate cardiovascular (CV) risk, Systematic COronary Risk Evaluation (SCORE) or Framingham-REgistre GIroní del COR (REGICOR), should be used in patients with rheumatoid arthritis (RA). Methods: A series of RA patients seen over a one-year period without history of CV events were assessed. SCORE, REGICOR, modified (m)SCORE and mREGICOR according to the European League Against Rheumatism (EULAR) recommendations were applied. Carotid ultrasonography (US) was performed. Carotid intima-media thickness (cIMT) > 0.90 mm and/or carotid plaques were used as the gold standard test for severe subclinical atherosclerosis and high CV risk (US+). The area under the receiver operating curves (AUC) for the predicted risk for mSCORE and mREGICOR were calculated according to the presence of severe carotid US findings (US+). Results: We included 370 patients (80% women; mean age 58.9 ± 13.7 years); 36% had disease duration of 10 years or more; rheumatoid factor (RF) and/or anticyclic citrullinated peptide (anti-CCP) were positive in 68%; and 17% had extra-articular manifestations. The EULAR multiplier factor was used in 122 (33%) of the patients. The mSCORE was 2.16 ± 2.49% and the mREGICOR 4.36 ± 3.46%. Regarding US results, 196 (53%) patients were US+. The AUC mSCORE was 0.798 (CI 95%: 0.752 to 0.844) and AUC mREGICOR 0.741 (95% CI; 0.691 to 0.792). However, mSCORE and mREGICOR failed to identify 88% and 91% of US+ patients. More than 50% of patients with mSCORE ≥1% or mREGICOR >1% were US+. Conclusions: Neither of these two function charts was useful in estimating CV risk in Spanish RA patients

Gaia Early Data Release 3: Summary of the Contents and Survey Properties

This article has an erratum: [https://doi.org/10.1051/0004-6361/202039657e][Abstract] Context. We present the early installment of the third Gaia data release, Gaia EDR3, consisting of astrometry and photometry for 1.8 billion sources brighter than magnitude 21, complemented with the list of radial velocities from Gaia DR2. Aims. A summary of the contents of Gaia EDR3 is presented, accompanied by a discussion on the differences with respect to Gaia DR2 and an overview of the main limitations which are present in the survey. Recommendations are made on the responsible use of Gaia EDR3 results. Methods. The raw data collected with the Gaia instruments during the first 34 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium and turned into this early third data release, which represents a major advance with respect to Gaia DR2 in terms of astrometric and photometric precision, accuracy, and homogeneity. Results. Gaia EDR3 contains celestial positions and the apparent brightness in G for approximately 1.8 billion sources. For 1.5 billion of those sources, parallaxes, proper motions, and the (GBP − GRP) colour are also available. The passbands for G, GBP, and GRP are provided as part of the release. For ease of use, the 7 million radial velocities from Gaia DR2 are included in this release, after the removal of a small number of spurious values. New radial velocities will appear as part of Gaia DR3. Finally, Gaia EDR3 represents an updated materialisation of the celestial reference frame (CRF) in the optical, the Gaia-CRF3, which is based solely on extragalactic sources. The creation of the source list for Gaia EDR3 includes enhancements that make it more robust with respect to high proper motion stars, and the disturbing effects of spurious and partially resolved sources. The source list is largely the same as that for Gaia DR2, but it does feature new sources and there are some notable changes. The source list will not change for Gaia DR3. Conclusions. Gaia EDR3 represents a significant advance over Gaia DR2, with parallax precisions increased by 30 per cent, proper motion precisions increased by a factor of 2, and the systematic errors in the astrometry suppressed by 30–40% for the parallaxes and by a factor ~2.5 for the proper motions. The photometry also features increased precision, but above all much better homogeneity across colour, magnitude, and celestial position. A single passband for G, GBP, and GRP is valid over the entire magnitude and colour range, with no systematics above the 1% levelXunta de Galicia; ED431B-2018/42Xunta de Galicia; ED481A-2019/155Xunta de Galicia; ED431G-2019/01Generalitat de Catalunya; 2014-SGR-1051https://doi.org/10.1051/0004-6361/202039657