Unveiling the past evolution of the progenitor of the Helmi streams

Aims. We aim to determine unique features that characterise the past evolution of the progenitor of the Helmi streams through the analysis of star formation histories (SFHs). Methods. From the 5D Gaia EDR3 dataset, we extracted local samples of stars dominated by the Helmi streams, the Galactic (thick and thin) disc, and the local retrograde halo. We did this by identifying regions in a pseudo-Cartesian velocity space (obtained by setting line-of-sight velocities to zero), where stars belonging to these components, as identified in samples with 6D phase-space information, are predominantly found. We made use of an updated absolute colour-magnitude diagram (CMD) fitting methodology to contrast the SFHs of these samples to unveil distinct signatures of the past evolution of a disrupted accreted system: the Helmi streams. To this end, special attention was given to the correct characterisation of Gaia completeness effects and observational errors on the CMD. We further investigated alternative sample selections to improve the purity of our 5D Helmi stream catalogues. Results. We find that the progenitor of the Helmi streams experienced an early star formation that was sustained for longer (until 7-9 Gyr ago) than for the MilkyWay halo (10-11 Gyr ago). As a consequence, half of its stellar mass was in place similar to 0.7 Gyr later. The quenching of star formation in the Helmi stream progenitor similar to 8 Gyr ago suggests it was accreted by the Milky Way around this time, in concert with previous estimates based on the dynamics of the streams.Spinoza prize MCIN/AEI PID2020-114414GB-100 IJC2020-043742-IFundacion Jesus SerraInstituto de Astrofisica de Canaria

The CALIFA survey across the Hubble sequence Spatially resolved stellar population properties in galaxies

Various different physical processes contribute to the star formation and stellar mass assembly histories of galaxies. One important approach to understanding the significance of these different processes on galaxy evolution is the study of the stellar population content of today’s galaxies in a spatially resolved manner. The aim of this paper is to characterize in detail the radial structure of stellar population properties of galaxies in the nearby universe, based on a uniquely large galaxy sample, considering the quality and coverage of the data. The sample under study was drawn from the CALIFA survey and contains 300 galaxies observed with integral field spectroscopy. These cover a wide range of Hubble types, from spheroids to spiral galaxies, while stellar masses range from M? ∼ 109 to 7 × 1011 M . We apply the fossil record method based on spectral synthesis techniques to recover the following physical properties for each spatial resolution element in our target galaxies: the stellar mass surface density (µ?), stellar extinction (AV ), light-weighted and mass-weighted ages (hlog ageiL, hlog ageiM), and mass-weighted metallicity (hlog Z?iM). To study mean trends with overall galaxy properties, the individual radial profiles are stacked in seven bins of galaxy morphology (E, S0, Sa, Sb, Sbc, Sc, and Sd). We confirm that more massive galaxies are more compact, older, more metal rich, and less reddened by dust. Additionally, we find that these trends are preserved spatially with the radial distance to the nucleus. Deviations from these relations appear correlated with Hubble type: earlier types are more compact, older, and more metal rich for a given M?, which is evidence that quenching is related to morphology, but not driven by mass. Negative gradients of hlog ageiL are consistent with an inside-out growth of galaxies, with the largest hlog ageiL gradients in Sb–Sbc galaxies. Further, the mean stellar ages of disks and bulges are correlated and with disks covering a wider range of ages, and late-type spirals hosting younger disks. However, age gradients are only mildly negative or flat beyond R ∼ 2 HLR (half light radius), indicating that star formation is more uniformly distributed or that stellar migration is important at these distances. The gradients in stellar mass surface density depend mostly on stellar mass, in the sense that more massive galaxies are more centrally concentrated. Whatever sets the concentration indices of galaxies obviously depends less on quenching/morphology than on the depth of the potential well. There is a secondary correlation in the sense that at the same M? early-type galaxies have steeper gradients. The µ? gradients outside 1 HLR show no dependence on Hubble type. We find mildly negative hlog Z?iM gradients, which are shallower than predicted from models of galaxy evolution in isolation. In general, metallicity gradients depend on stellar mass, and less on morphology, hinting that metallicity is affected by both – the depth of the potential well and morphology/quenching. Thus, the largest hlog Z?iM gradients occur in Milky Way-like Sb–Sbc galaxies, and are similar to those measured above the Galactic disk. Sc spirals show flatter hlog Z?iM gradients, possibly indicating a larger contribution from secular evolution in disks. The galaxies from the sample have decreasing-outward stellar extinction; all spirals show similar radial profiles, independent from the stellar mass, but redder than E and S0. Overall, we conclude that quenching processes act in manners that are independent of mass, while metallicity and galaxy structure are influenced by mass-dependent processes.CALIFA is the first legacy survey carried out at Calar Alto. The CALIFA collaboration would like to thank the IAA-CSIC and MPIA-MPG as major partners of the observatory, and CAHA itself, for the unique access to telescope time and support in manpower and infrastructures. We also thank the CAHA staff for the dedication to this project. Support from the Spanish Ministerio de Economía y Competitividad, through projects AYA2010-15081 (PI R.G.D.), and Junta de Andalucía FQ1580 (PI R.G.D.), AYA2010-22111-C03-03, and AYA2010-10904E (S.F.S.). We also thank the Viabilidad, Diseño, Acceso y Mejora funding program, ICTS-2009-10, for funding the data acquisition of this project. R.C.F. thanks the hospitality of the IAA and the support of CAPES and CNPq. R.G.D. acknowledges the support of CNPq (Brazil) through Programa Ciencia sem Fronteiras (401452/2012-3). A.G. acknowledges support from EU FP7/2007-2013 under grant agreement n.267251 (AstroFIt) and from the EU Marie Curie Integration Grant “SteMaGE” Nr. PCIG12-GA-2012-326466. C.J.W. acknowledges support through the Marie Curie Career Integration Grant 303912. E.P. acknowledges support from the Guillermo Haro program at INAOE. Support for L.G. is provided by the Ministry of Economy, Development, and Tourism’s Millennium Science Initiative through grant IC120009, awarded to The Millennium Institute of Astrophysics, MAS. L.G. acknowledges support by CONICYT through FONDECYT grant 3140566. J.I.P. acknowledges financial support from the Spanish MINECO under grant AYA2010-21887- C04-01 and from Junta de Andalucía Excellence Project PEX2011-FQM7058. I.M., J.M. and A.d.O. acknowledge support from the project AYA2013-42227-P. RAM is funded by the Spanish program of International Campus of Excellence Moncloa (CEI). J.M.A. acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild

Determinants of elimination decisions in the activity scheduling process

[EN] This paper presents an analysis on the determinants related to a particular rescheduling decision in the activity-travel scheduling process: elimination decisions, which consist in the non-execution of pre-planned activity-travel episodes. Data used come from an in-depth computer-assisted telephone interview (CATI) follow up survey carried out during the implementation of the first wave of an activity scheduling process panel survey. Open-ended answers related to the reasons associated to changes between pre-planned and executed agenda are studied. First, an interpretative qualitative method based on analytic induction (AI) is used to cope with the complex nature of the rescheduling decision under study and the characteristics of the available data. Then, econometric models are used to analyze factors influencing those decisions and complement the qualitative analysis. The detailed qualitative and quantitative study of those decisions has resulted in the identification of several reasons associated to the elimination of activity-travel episodes from the activity agenda. Factors influencing those reasons have been explored.Mars, L.; Ruiz Sánchez, T. (2017). Determinants of elimination decisions in the activity scheduling process. Transportation Letters. doi:10.1080/19427867.2016.1242882

Genu valgum artrósico: tratamiento mediante osteotomías

La artrosis sobre genu valgum no es frecuente y relativamente bien tolerada. Suele ser de origen constitucional, y a veces de origen displásico o traumático. Antes de decidir una artroplastia total de rodilla en pacientes jóvenes hay que apreciar la posibilidad de realizar una osteotomía en estadios precoces de la enfermedad. La biomecánica es la base de esta decisión, precisando la necesidad de conseguir siempre una línea articular fémoro-tibial paralela al suelo. Por ello, la osteotomía varizante del fémur es la mejor indicación. La osteotomía varizante proximal de tibia apenas está indicada, salvo en casos traumáticos (fractura del platillo tibial externo). Se exponen la técnica, resultados y repercusión a distancia sobre la rodilla, ante una posible artroplastia totalThe lateral compartment artrosis of the knee is not frequent and huge well tolerated. The ethiology in the most cases in constitutional or secondary to displasy or trauma. We need appreciated the possibility to do corrective osteotomy before total arthroplasty in young patients with non severe degree of disease. The biomechanics is the base line of this possibility and the aim is to obtain an articular line in a horizontal position. It is the reason why the distal femoral osteotomy is the election site for it. In rare situations, like malunion of proximal tibial fracture (external tibial plateau) or light degrees of osteoarthrosis, the high proximal tibial osteotomy is indicated. Finally, technique, results and long-term problems of the knee before a total arthroplasty of the knee are expose

Gestión estratégica del área de seguimiento y control de créditos en un banco

El presente trabajo de investigación ha sido elaborado con la finalidad de contribuir en la prevención del incremento de la morosidad en los créditos comerciales del Banco A, debido al impacto de la crisis financiera internacional en el entorno económico peruano. La morosidad se ha incrementado paulatinamente desde octubre de 2008. Como resultado de este impacto, las entidades del sistema financiero incrementan sus provisiones por sus colocaciones, reduciendo sus márgenes de contribución. Para ello hemos aplicado distintas herramientas aprendidas en los cursos de la Maestría en el análisis el Banco A, encontrando que el Área de Seguimiento y Control de Créditos del Banco, tiene como función principal prever situaciones de riesgo de pérdida, a través del monitoreo sistemático de la cartera de créditos comerciales de sus clientes; motivándonos a desarrollar una propuesta de Gestión Estratégica del Área

Bacteria and the evolution of honest signals. The case of ornamental throat feathers in spotless starlings

1. Mechanisms guaranteeing reliability of messages are essential in understanding the underlying information and evolution of signals. Micro-organisms may degrade signalling traits and therefore influence the transmitted information and evolution of these characters. The role of micro-organisms in animal signalling has, however, rarely been investigated. 2. Here, we explore a possible role for feather-degrading bacteria driving the design of ornamental throat feathers in male spotless starlings (Sturnus unicolor). We estimated length, bacterial load, degradation status and susceptibility to degradation by keratinolytic bacteria in those feathers, compared with non-ornamental adjacent feathers in males, as well as to throat feathers in females. In addition, the volume of the uropygial gland and its secretion was measured and the secretion extracted. We also experimentally evaluated the capacity of each secretion to inhibit growth of a keratinolytic bacterium. 3. The apical part of male ornamental throat feathers harboured more bacteria and degraded more quickly than the basal part; these patterns were not detected in female throat feathers or in non-ornamental male feathers. Moreover, degradation status of male and female throat feathers did not differ, but was positively associated with feather bacterial density. Finally, the size of the uropygial gland in both males and females predicted volume and the inhibitory capacity of secretion against feather-degrading bacteria. Only in males was uropygial gland size negatively associated with the level of feather degradation. 4. All results indicate differential susceptibility of different parts of throat feathers to keratinolytic bacterial attack, which supports the possibility that throat feathers in starlings reflect individual ability to combat feather-degrading bacteria honestly. This is further supported by the relationship detected between antimicrobial properties of uropygial secretion and the level of feather degradation. 5. Our results suggest that selection pressures exerted by feather-degrading bacteria on hosts may promote evolution of particular morphologies of secondary sexual traits with different susceptibility to bacterial degradation that reliably inform of their bacterial load. Those results will help to understand the evolution of ornamental signals.This work was financed by Spanish Ministerio de Ciencia e Innovaci on, European funds (FEDER) (CGL2010-19233-C03-01, CGL2013-48193-C3-1-P). MRR and DMG received a postdoc from the program “JAE-Doc”, GT from the “Juan de la Cierva”, and CRC had a predoctoral fellowship, all from the Spanish Government.Peer reviewe

Effects of 8-Weeks Concurrent Strength and Aerobic Training on Body Composition, Physiological and Cognitive Performance in Older Adult Women

(1) Background: Despite plenty of evidence supporting the advantages of regular physical exercise amongst older women, it is not clear what the best methodology is to improve these parameters. Considering the growth of older population and aging process, this study analyses an 8-weeks concurrent training intervention; (2) Methods: A total of 48 older women participated in concurrent strength and aerobic exercises training intervention being used to know physical and cognitive improvements in older women through physical, physiological and vigilance tests; (3) Results: Significant differences were found in weight and body mass index (BMI) between pre-intervention and post-intervention and even better results, but non-significative, in maximum oxygen consumption (VO2max), total fat percentage and skeletal muscle mass. Additionally, we found cognitive improvements in vigilance (RT) related to executive functions. (4) Conclusions: An 8-weeks concurrent training program (strength and aerobic exercises) give another efficient possibility to obtain better physical, physiological and cognitive improvements in older women

Modification of the morphology, porosity and surface chemistry of lignin-based electrospun carbon materials

Lignin is a biopolymer that can be found as the main component of plants. It is obtained as a coproduct in the papermaking and biofuel industries. Owing to its high carbon and aromatic content, high availability and reduced cost, it is an excellent precursor for the preparation of highly valued carbon materials. Electrospinning is a suitable top-down technique for the preparation of polymeric fibers using high voltage electrical fields and polymer solutions of proper viscosity and conductivity. Organosolv lignins, which are extracted from lignocellulosic biomass using organic solvents, are soluble in ethanol, obtaining a solution that matches the requirement of the electrospinning process. In this way, it is possible to produce lignin-based porous carbon fibers using a coaxial electrospinning device [1]. This contribution summarizes our findings about the preparation of carbon materials with different morphologies and composition by processing lignin using electrohydrodynamic forces. Lignin spheres, beaded fibers, straight fibers, beaded tubes and straight tubes are obtained by using coaxial and triaxial spinnerets that allows the electrospinning of two or three different solutions at once [1], Fig. 1. Thermal stabilization in air is needed in order to avoid melting of lignin fibers during carbonization. Stabilization times of 48-96 hours are usually required in this step, decreasing the sustainability of the production process. Phosphoric acid can be added in small amounts in the lignin solution, shortening the time for achieve a successful thermostabilization of the fiber [2]. The carbonized materials show narrow microporosity and large surface area values (SBET from 600 to 1000 m2g-1) and additional pore size and volume can be developed by controlled gasification.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This work was supported by the Spanish Ministry of Economy and Competitiveness and FEDER (CTQ-2015-68654-R)