NGC 3105: a young open cluster with low metallicity

NGC 3105 is a young open cluster hosting blue, yellow and red supergiants. This rare combination makes it an excellent laboratory to constrain evolutionary models of high-mass stars. It is poorly studied and fundamental parameters such as its age or distance are not well defined. We intend to characterize in an accurate way the cluster as well as its evolved stars, for which we derive for the first time atmospheric parameters and chemical abundances. We identify 126 B-type likely members within a radius of 2.7$\pm$0.6 arcmin, which implies an initial mass, $M_{cl}\approx$4100 M$_{\odot}$. We find a distance of 7.2$\pm$0.7 kpc for NGC 3105, placing it at $R_{GC}$=10.0$\pm$1.2 kpc. Isochrone fitting supports an age of 28$\pm$6 Ma, implying masses around 9.5 M$_{\odot}$ for the supergiants. A high fraction of Be stars ($\approx$25 %) is found at the top of the main sequence down to spectral type b3. From the spectral analysis we estimate for the cluster a $v_{rad}$=+46.9$\pm$0.9 km s$^{-1}$ and a low metallicity, [Fe/H]=-0.29$\pm$0.22. We also have determined, for the first time, chemical abundances for Li, O, Na, Mg, Si, Ca, Ti, Ni, Rb, Y, and Ba for the evolved stars. The chemical composition of the cluster is consistent with that of the Galactic thin disc. An overabundance of Ba is found, supporting the enhanced $s$-process. NGC 3105 has a low metallicity for its Galactocentric distance, comparable to typical LMC stars. It is a valuable spiral tracer in a very distant region of the Carina-Sagittarius spiral arm, a poorly known part of the Galaxy. As one of the few Galactic clusters containing blue, yellow and red supergiants, it is massive enough to serve as a testbed for theoretical evolutionary models close to the boundary between intermediate and high-mass stars.Comment: 18 pages, 13 figures. Accepted for publication in A&

Notas sobre el género Otidea (Pezizomycotina: Pezizales: Pyronemataceae) en México

ResumenEl género Otidea en México está representado por 8 taxones, 6 especies y 2 variedades. Otidea concinna es un nuevo registro para México. Se citan nuevas recolectas del género para los estados de Chiapas, Distrito Federal, Morelos y Veracruz.AbstractThe genus Otidea in Mexico is represented by 8 taxa, 6 species and 2 varieties. Otidea concinna is a new record for Mexico and new collections of Otidea from the states of Chiapas, Distrito Federal, Morelos and Veracruz are cited

Variability of the stomata among 'Albariño' (Vitis vinifera L.) clones and its relationship with susceptibility to downy mildew

Research Note

NGC 6067: A young and massive open cluster with high metallicity

© 2017 The Authors. NGC6067 is a young open cluster hosting the largest population of evolved stars among known Milky Way clusters in the 50-150 Ma age range. It thus represents the best laboratory in our Galaxy to constrain the evolutionary tracks of 5-7M⊙ stars. We have used high-resolution spectra of a large sample of bright cluster members (45), combined with archival photometry, to obtain accurate parameters for the cluster as well as stellar atmospheric parameters.We derive a distance of 1.78 ± 0.12 kpc, an age of 90 ± 20 Ma and a tidal radius of 14.8 -3.2+6.8 arcmin. We estimate an initial mass above 5700M⊙, for a present-day evolved population of two Cepheids, two A supergiants and 12 red giants with masses ≈6M⊙. We also determine chemical abundances of Li, O, Na, Mg, Si, Ca, Ti, Ni, Rb, Y and Ba for the red clump stars. We find a supersolar metallicity, [Fe/H]=+0.19 ± 0.05, and a homogeneous chemical composition, consistent with the Galactic metallicity gradient. The presence of a Li-rich red giant, star 276 with A(Li)=2.41, is also detected. An overabundance of Ba is found, supporting the enhanced s-process. The ratio of yellow to red giants is much smaller than 1, in agreement with models with moderate overshooting, but the properties of the cluster Cepheids do not seem consistent with current Padova models for supersolar metallicity

Macro- and microscopic leaf characteristics of six grapevine genotypes (Vitis spp.) with different susceptibilities to grapevine downy mildew

This work reports the leaf morphology of six grapevine genotypes, five belonging to Vitis vinifera and one to Vitis riparia. Earlier studies on these genotypes showed different levels of susceptibility to grapevine downy mildew (Plasmopara viticola). The aim of this work was to detect differences between the leaf morphology of these cultivars at the macro- and microscopic levels, and to characterize morphological traits which could be associated with susceptibility and resistance to downy mildew. An ampelographic description of each genotype was used to develop a scheme illustrating the characteristic leaf morphology. The density and morphology of the trichomes and the stomatal index was assessed by means of microscopical techniques. Distinct macro and microscope differences among the genotypes were seen. No clear relation between ampelographic characteristics and susceptibility to downy mildew was observed. The two cultivars that in earlier studies were found to be the least susceptible to downy mildew were the most similar in terms of their spongy mesophyll. Both showed very little or no wax on the abaxial surface of their leaves.

Computational design-of-experiment unveils the conformational reaction coordinate of GH125 α-mannosidases

Conformational analysis of enzyme-catalyzed mannoside hydrolysis has revealed two predominant conformational itineraries through B 2,5 or 3H 4 transitionstate (TS) conformations. A prominent unassigned catalytic itinerary is that of exo-1,6-α-mannosidases belonging to CAZy family 125. A published complex of Clostridium perfringens GH125 enzyme with a nonhydrolyzable 1,6-α-thiomannoside substrate mimic bound across the active site revealed an undistorted 4 C 1 conformation and provided no insight into the catalytic pathway of this enzyme. We show through a purely computational approach (QM/MM metadynamics) that sulfur-for-oxygen substitution in the glycosidic linkage fundamentally alters the energetically accessible conformational space of a thiomannoside when bound within the GH12S active site. Modeling of the conformational free energy landscape (FEL) of a thioglycoside strongly favors a mechanistically uninformative 4 C 1 conformation within the GH125 enzyme active site, but the FEL of corresponding O-glycoside substrate reveals a preference for a Michaelis complex in an oS 2 conformation (consistent with catalysis through a B 2,5 TS). This prediction was tested experimentally by determination of the 3D X-ray structure of the pseudo-Michaelis complex of an inactive (D220N) variant of C. perfringens GH125 enzyme in complex with 1,6-α-mannobiose. This complex revealed unambiguous distortion of the -1 subsite mannoside to an oS 2 conformation, matching that predicted by theory and supporting an oS 2 → B 2,5 → 1S 5 conformational itinerary for GH125 α-mannosidases. This work highlights the power of the QM/MM approach and identified shortcomings in the use of nonhydrolyzable substrate analogues for conformational analysis of enzymebound species

Lifeguard assistance at Spanish Mediterranean beaches: Jellyfish prevail and proposals for improving risk management

Although beaches can be hazardous environments, few studies have identified injuries in broad coastal areas. We performed a retrospective descriptive study of injuries and other services provided by lifeguards during 2012 along the Spanish Mediterranean beaches. The trend in jellyfish stings was also examined for the period 2008–2012 using a standardised Sting Index. Obtaining data relied on voluntary cooperation of local authorities, resulting in data provided from 183 cities out of 234 present in the study area and 760 beach lifeguard stations (LGS) out of about 1200. Lifeguard stations provided an average of 89 days of service per year, from late June to the beginning of September. A total of 176,021 injuries were reported, of which jellyfish stings were the main need for assistance with 59.7% (n = 116,887) of the injuries and 257.0/LGS, followed by wounds (14.4%, 50.9/LGS), and sunburn (3.3%, 15.8/LGS). Apart from attending injuries, beach lifeguard services provided 21,174 other services such as help to disabled people (57.9/LGS), blood pressure measurements (12.7/LGS), rescues at sea (6.5/LGS), lost children (5.7/LGS), and transfers to the hospital (4.6/LGS). Official reported fatalities for all the beaches in 2012 were 24. We proposed a Sting Index (SI) to allow comparisons of the incidence of stings between years and/or localities by standardising jellyfish stings by the total of all injuries. Historical data were consistent enough to calculate SI between 2010 and 2012 and showed an oscillating pattern without a clear trend (2008: 2.4, 2009: 1.3, 2010: 2.4, 2011: 2.0, 2012: 2.6). Estimation of total number of jellyfish stings for all the beaches present in the area would reach 184,558 for 2012. There were very few fatalities in comparison with other coastal regions, probably due to the combination of a calm sea, a low number of high dangerous situations, and a high percentage of lifeguarded beaches during the bathing season. Nevertheless, although Spanish Mediterranean beaches could be described as low risk, we propose measures to facilitate a precautionary management to prevent injuries based on a real-time beach assistance database of injuries to identify high-incidence assistance categories.This research was carried out under contract LIFE 08 NAT ES 0064 (to CB and VF) co-financed by the European Commission (www.cubomed.eu), the Ministerio de Agricultura, Alimentación y Medio Ambiente (Dirección General de Sostenibilidad de la Costa y el Mar) contract 2013/28-5158, the Dirección General del Agua of the Regional Government of Valencia (grant T7588000/512.10) and the Fundación Biodiversidad (grant LIFE Cubomed 2013/2014)

TIC 43152097. The first eclipsing binary in NGC 2232

We report the discovery of a low-mass totally eclipsing system in the young (age$\simeq$28 Myr) open cluster NGC2232, during a scrutiny of their TESS light curves. The follow-up study of this detached system, TIC 43152097, is based on photometry and high-resolution spectra from the literature and purposely collected. The radial velocity of the center of mass, as well as the photospheric lithium abundance of the binary components, confirm its membership to NGC2232. By analyzing the existing photometric and spectroscopic data, we obtain orbital elements and fundamental stellar parameters for the two stars. The primary component of TIC 43152097 is a late F-type dwarf (Teff = 6070 K), while the lower-mass secondary results to be a late K-type star (Teff = 4130 K) that is still in the pre-main-sequence phase. The precise measurements of radii, masses, and effective temperatures, enabled by the simultaneous solution of light and radial velocity curves, indicate radius inflation for the K-type component, which turns out to be 7-11 % larger than predicted by standard evolutionary models. More sophisticated models incorporating both inhibition of convective energy transport caused by sub-photospheric magnetic fields and the effects by cool starspots covering a substantial fraction of the stellar surface (30-60 %) allow reproducing the position of the secondary component in the Hertzsprung-Russell and Mass-Radius diagrams.Comment: 11 pages, 15 figures; accepted for publication in Astronomy & Astrophysic

Nextmed: Automatic Imaging Segmentation, 3D Reconstruction, and 3D Model Visualization Platform Using Augmented and Virtual Reality

The visualization of medical images with advanced techniques, such as augmented reality and virtual reality, represent a breakthrough for medical professionals. In contrast to more traditional visualization tools lacking 3D capabilities, these systems use the three available dimensions. To visualize medical images in 3D, the anatomical areas of interest must be segmented. Currently, manual segmentation, which is the most commonly used technique, and semi-automatic approaches can be time consuming because a doctor is required, making segmentation for each individual case unfeasible. Using new technologies, such as computer vision and artificial intelligence for segmentation algorithms and augmented and virtual reality for visualization techniques implementation, we designed a complete platform to solve this problem and allow medical professionals to work more frequently with anatomical 3D models obtained from medical imaging. As a result, the Nextmed project, due to the different implemented software applications, permits the importation of digital imaging and communication on medicine (dicom) images on a secure cloud platform and the automatic segmentation of certain anatomical structures with new algorithms that improve upon the current research results. A 3D mesh of the segmented structure is then automatically generated that can be printed in 3D or visualized using both augmented and virtual reality, with the designed software systems. The Nextmed project is unique, as it covers the whole process from uploading dicom images to automatic segmentation, 3D reconstruction, 3D visualization, and manipulation using augmented and virtual reality. There are many researches about application of augmented and virtual reality for medical image 3D visualization; however, they are not automated platforms. Although some other anatomical structures can be studied, we focused on one case: a lung study. Analyzing the application of the platform to more than 1000 dicom images and studying the results with medical specialists, we concluded that the installation of this system in hospitals would provide a considerable improvement as a tool for medical image visualization

Una variedad blanca (Vitis vinifera L.) de alto interés comercial, y en vías de extinción. Sinonimias y homonimias

Comunicación presentada al X Congreso Nacional de Ciencias Hortícolas, celebrado en Pontevedra en mayo de 2003.Peer reviewe