The LMC distance modulus from Hipparcos RR-Lyrae and classical Cepheid data

The LM method \cite{luri96}, designed to exploit the Hipparcos data to obtain luminosity calibrations, is applied to derive luminosity calibrations for RR Lyrae and classical Cepheids. From these calibrations the distance to the Large Magellanic Cloud (LMC) is estimated. The distance moduli provided by the two calibrations are in good agreement, giving a value of ~ 18.3(m) , while several previous calibrations using Hipparcos data provided inconsistent results between both types of stars. This result suggest that the Hubble constant should have a value of H_0 ~ 79 km s(-1) Mpc(-1)

Barium stars, galactic populations and evolution

In this paper HIPPARCOS astrometric and kinematical data together with radial velocities from other sources are used to calibrate both luminosity and kinematics parameters of Ba stars and to classify them. We confirm the results of our previous paper (where we used data from the HIPPARCOS Input Catalogue), and show that Ba stars are an inhomogeneous group. Five distinct classes have been found i.e. some halo stars and four groups belonging to disk population: roughly super-giants, two groups of giants (one on the giant branch, the other at the clump location) and dwarfs, with a few subgiants mixed with them. The confirmed or suspected duplicity, the variability and the range of known orbital periods found in each group give coherent results supporting the scenario for Ba stars that are not too highly massive binary stars in any evolutionary stages but that all were previously enriched with Ba from a more evolved companion. The presence in the sample of a certain number of ``false'' Ba stars is confirmed. The estimates of age and mass are compatible with models for stars with a strong Ba anomaly. The mild Ba stars with an estimated mass higher than 3Msun_ may be either stars Ba enriched by themselves or ``true'' Ba stars, which imposes new constraints on models

The HR diagram from Hipparcos data. Absolute magnitudes and kinematics of Bp-Ap stars

The HR-diagram of about 1000 Bp - Ap stars in the solar neighbourhood has been constructed using astrometric data from Hipparcos satellite as well as photometric and radial velocity data. The LM method \cite{luri95,luri96} allows the use of proper motion and radial velocity data in addition to the trigonometric parallaxes to obtain luminosity calibrations and improved distances estimates. Six types of Bp - Ap stars have been examined: He-rich, He-weak, HgMn, Si, Si+ and SrCrEu. Most Bp - Ap stars lie on the main sequence occupying the whole width of it (about 2 mag), just like normal stars in the same range of spectral types. Their kinematic behaviour is typical of thin disk stars younger than about 1 Gyr. A few stars found to be high above the galactic plane or to have a high velocity are briefly discussed. Based on data from the ESA Hipparcos astrometry satellite and photometric data collected in the Geneva system at ESO, La Silla (Chile) and at Jungfraujoch and Gornergrat Observatories (Switzerland). Tables 3 and 4 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.htm

Absolute magnitude and kinematics of Barium stars

The absolute magnitude of barium stars has been obtained from kinematical data using a new algorithm based on the maximum-likelihood principle. The method allows to separate a sample into groups characterized by different mean absolute magnitudes, kinematics and z-scale heights. It also takes into account, simultaneously, the censorship in the sample and the errors on the observables. The method has been applied to a sample of 318 barium stars. Four groups have been detected. Three of them show a kinematical behaviour corresponding to disk population stars. The fourth group contains stars with halo kinematics. The luminosities of the disk population groups spread a large range. The intrinsically brightest one (M_v_=-1.5mag, σ_M_=0.5mag) seems to be an inhomogeneous group containing barium binaries as well as AGB single stars. The most numerous group (about 150 stars) has a mean absolute magnitude corresponding to stars in the red giant branch (M_v_=0.9mag, σ_M_=0.8mag). The third group contains barium dwarfs, the obtained mean absolute magnitude is characteristic of stars on the main sequence or on the subgiant branch (M_v_=3.3mag, σ_M_=0.5mag). The obtained mean luminosities as well as the kinematical results are compatible with an evolutionary link between barium dwarfs and classical barium giants. The highly luminous group is not linked with these last two groups. More high-resolution spectroscopic data will be necessary in order to better discriminate between barium and non-barium stars

Comparación de los sistemas de formación en seto y en vaso libre con la variedad de almendro Soleta

El aumento de la demanda de almendra, el desarrollo de nuevas variedades autofértiles y de floración tardía, y el establecimiento de plantaciones en nuevas zonas de regadío han propiciado notables progresos en las técnicas productivas del cultivo del almendro. Una de las más importantes ha sido el aumento de la densidad de plantación, gracias al desarrollo de portainjertos enanizantes. En este trabajo se presenta una comparación entre dos sistemas de formación con la variedad de almendro ‘Soleta’: en seto sobre portainjerto Rootpac-20, frente a la formación en vaso libre sobre portainjerto GF-677. Para ello, se ha realizado un seguimiento, a lo largo de un ciclo vegetativo, de varios parámetros que reflejan el estado clorofílico (fluorescencia y SPAD) y la intercepción lumínica (LAI/fPAR), y se han evaluado otros condicionantes productivos (floración, cuajado y producción) en momentos puntuales del ciclo. Se han observado diferencias entre ambos sistemas en cuanto a peso medio del fruto, producción por volumen de copa y otras características. El grado de eficiencia en el aprovechamiento de los recursos o inputs productivos ha resultado enteramente favorable al nuevo sistema de formación en seto, por lo que su potencial para convertirse en un sistema de referencia en las plantaciones modernas (haciendo uso de cosechadoras cabalgantes similares a las utilizadas para vid y olivo) parece indudable

Comparación de los sistemas de formación en seto y en vaso libre con la variedad de almendro «soleta»

El aumento de la demanda de la almendra, junto con el desarrollo de nuevas variedades autofértiles y de floración tardía, junto al establecimiento de plantaciones en nuevas zonas de regadío, han propiciado notables progresos en las técnicas productivas del cultivo del almendro cada vez más similares a las de las especies de fruta dulce. Una de las más importantes ha sido el aumento de la densidad de plantación, gracias al desarrollo de portainjertos enanizantes. En este trabajo se presenta una comparación entre dos sistemas de formación con la variedad de almendro ‘Soleta’: en seto sobre portainjerto Rootpac®20, frente a la formación en vaso libre sobre portainjerto INRA GF®677. Para ello, se ha realizado un seguimiento, a lo largo de un ciclo vegetativo, de varios parámetros que reflejan el estado clorofílico (fluorescencia y SPAD) y la intercepción lumínica (LAI/fPAR) y se han evaluado otros condicionantes productivos (floración, cuajado y producción) en momentos puntuales del ciclo. Se han observado diferencias entre ambos sistemas en cuanto a peso medio del fruto, producción por volumen de copa y otras características agronómicas. El grado de eficiencia en el aprovechamiento de los recursos o inputs productivos ha resultado favorable al nuevo sistema de formación en seto, por lo que su potencial para convertirse en un sistema de referencia en las plantaciones modernas, mediante el uso de cosechadoras cabalgantes similares a las utilizadas para vid y olivo, parece indudabl

The intricate Galaxy disk: velocity asymmetries in Gaia-TGAS

We use Gaia-TGAS data to compare the transverse velocities in Galactic longitude (coming from proper motions and parallaxes) in the Milky Way disk for negative and positive longitudes as a function of distance. The transverse velocities are strongly asymmetric and deviate significantly from the expectations for an axisymmetric galaxy. The value and sign of the asymmetry changes at spatial scales of several tens of degrees in Galactic longitude and about 0.5 kpc in distance. The asymmetry is statistically significant at 95% confidence level for 57% of the region probed, which extends up to 1.2 kpc. A percentage of 24% of the region shows absolute differences at this confidence level larger than 5 km s-1 and 7% larger than 10 km s-1. The asymmetry pattern shows mild variations in the vertical direction and with stellar type. A first qualitative comparison with spiral arm models indicates that the arms are probably not the main source of the asymmetry. We briefly discuss alternative origins. This is the first time that global all-sky asymmetries are detected in the Milky Way kinematics beyond the local neighbourhood and with a purely astrometric sample

Neurodevelopmental effects of undernutrition and placental underperfusion in fetal growth restriction rabbit models

Introduction: Chronic reduction of oxygen and nutrient delivery to the fetus has been related to neurodevelopmental problems. Placental underperfusion induces a significant reduction in oxygen and nutrient delivery, whereas maternal undernutrition causes mainly nutrient deficiency. A comparison of the neurodevelopmental effects of both situations in pregnant rabbits was performed. Materials and Methods: The placental underperfusion model was induced after uteroplacental vessel ligation at 25 days of pregnancy. The undernutrition model was induced after a reduction of 70% of the basal maternal intake at 22 days of pregnancy. Neurobehavioral tests were applied in the derived offspring at the neonatal period and over the long term. Structural brain differences were evaluated by brain networks obtained from diffusion magnetic resonance imaging. Results: Birth weight was significantly lower in both cases. However, stillbirth was only increased in the placental underperfusion model. Cases from both models presented poorer neurobehavioral performance and network infrastructure, being more pro-nounced in the placental underperfusion model. Discussion: Prenatal insults during the last third of gestation resulted in functional and structural disturbances. The degree of neurodevelopmental impairment and its association with structural brain reorganization seemed to be related to the type of the prenatal insult, showing stronger effects in the placental underperfusion model. (C) 2017 S. Karger AG, Base

Stellar physical parameters from Str ömgren photometry. Application to the young stars in the Galactic anticenter survey

M. Monguió, F. Figueras, and P. Grosbøl, “Stellar physical parameters from Strömgren photometry. Application to the young stars in the Galactic anticenter survey”, Astronomy & Astrophysics, Vol. 568, September 2014. Thhis version of record is available online at: https://doi.org/10.1051/0004-6361/201423703 Reproduced with Permission from Astronomy and Astrophysics, © ESO 2016.Aims. The aim is to derive accurate stellar distances and extinctions for young stars of our survey in the Galactic anticenter direction using the Str\"omgren photometric system. This will allow a detailed mapping of the stellar density and absorption toward the Perseus arm. Methods. We developed a new method for deriving physical parameters from Str\"omgren photometry and also implemented and tested it. This is a model-based method that uses the most recent available stellar atmospheric models and evolutionary tracks to interpolate in a 3D grid of the unreddened indexes [m1], [c1] and Hbeta. Distances derived from both this method and the classical pre-Hipparcos calibrations were tested against Hipparcos parallaxes and found to be accurate. Results. Systematic trends in stellar photometric distances derived from empirical calibrations were detected and quantified. Furthermore, a shift in the atmospheric grids in the range Teff=[7000,9000]K was detected and a correction is proposed. The two methods were used to compute distances and reddening for about 12000 OBA-type stars in our Str\"omgren anticenter survey. Data from the IPHAS and 2MASS catalogs were used to complement the detection of emission line stars and to break the degeneracy between early and late photometric regions. We note that photometric distances can differ by more than 20%, those derived from the empirical calibrations being smaller than those derived with the new method, which agree better with the Hipparcos data.Peer reviewe

Unravelling the Encapsulation of DNA and Other Biomolecules in HAp Microcalcifications of Human Breast Cancer Tissues by Raman Imaging

Microcalcifications are detected through mammography screening and, depending on their morphology and distribution (BI-RADS classification), they can be considered one of the first indicators of suspicious cancer lesions. However, the formation of hydroxyapatite (HAp) calcifications and their relationship with malignancy remains unknown. In this work, we report the most detailed three-dimensional biochemical analysis of breast cancer microcalcifications to date, combining 3D Raman spectroscopy imaging and advanced multivariate analysis in order to investigate in depth the molecular composition of HAp calcifications found in 26 breast cancer tissue biopsies. We demonstrate that DNA has been naturally adsorbed and encapsulated inside HAp microcalcifications. Furthermore, we also show the encapsulation of other relevant biomolecules in HAp calcifications, such as lipids, proteins, cytochrome C and polysaccharides. The demonstration of natural DNA biomineralization, particularly in the tumor microenvironment, represents an unprecedented advance in the field, as it can pave the way to understanding the role of HAp in malignant tissues