109 research outputs found

    NGC1277: a massive compact relic galaxy in the nearby Universe

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    As early as 10 Gyr ago, galaxies with more than 10^11 Msun in stars already existed. While most of these massive galaxies must have subsequently transformed through on-going star formation and mergers with other galaxies, a small fraction (<0.1%) may have survived untouched till today. Searches for such relic galaxies, useful windows to explore the early Universe, have been inconclusive to date: galaxies with masses and sizes like those observed at high redshift (M*>10^11 Msun; Re<1.5 kpc) have been found in the local Universe, but their stars are far too young for the galaxy to be a relic galaxy. This paper explores the first case of a nearby galaxy, NGC1277 (in the Perseus cluster at a distance of 73 Mpc), which fulfills all the criteria to be considered a relic galaxy. Using deep optical spectroscopy, we derive the star formation history along the structure of the galaxy: the stellar populations are uniformly old (>10 Gyr) with no evidence for more recent star formation episodes. The metallicity of their stars is super-solar ([Fe/H]=0.20+-0.04) and alpha enriched ([alpha/Fe]=0.4+-0.1). This suggests a very short formation time scale for the bulk of stars of this galaxy. This object also rotates very fast (Vrot~300 km/s) and has a large velocity dispersion (sigma>300 km/s). NGC1277 will allow future explorations in full detail of properties such as the structure, internal dynamics, metallicity, dust content and initial mass function at around 10-12 Gyr back in time when the first massive galaxies were built.Comment: 4 figures; Accepted for publication at ApJ Letter

    Design of a Lightweight, Cost Effective Thimble-Like Sensor for Haptic Applications Based on Contact Force Sensors

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    This paper describes the design and calibration of a thimble that measures the forces applied by a user during manipulation of virtual and real objects. Haptic devices benefit from force measurement capabilities at their end-point. However, the heavy weight and cost of force sensors prevent their widespread incorporation in these applications. The design of a lightweight, user-adaptable, and cost-effective thimble with four contact force sensors is described in this paper. The sensors are calibrated before being placed in the thimble to provide normal and tangential forces. Normal forces are exerted directly by the fingertip and thus can be properly measured. Tangential forces are estimated by sensors strategically placed in the thimble sides. Two applications are provided in order to facilitate an evaluation of sensorized thimble performance. These applications focus on: (i) force signal edge detection, which determines task segmentation of virtual object manipulation, and (ii) the development of complex object manipulation models, wherein the mechanical features of a real object are obtained and these features are then reproduced for training by means of virtual object manipulation

    Evolution of adolescent fertility after decriminalization of abortion in Montevideo, Uruguay

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    AbstractObjectiveTo analyze the effect on adolescent fertility in Montevideo of the Uruguayan law on the voluntary termination of pregnancy that was passed in 2012.MethodsThe change in the number of births to teenage mothers between 2010 and 2014 was analyzed, along with their characteristics before and after decriminalization of abortion.ResultsDescriptive analysis of abortion before and after decriminalization showed that there was no reduction, during the period analyzed, in adolescent fertility, nor any changes in the distribution of births.ConclusionThe normative change brought about by the law on the voluntary termination of pregnancy was not associated with any substantial change in the reproductive behavior of adolescents in Montevideo. We recommend that this analysis is taken further with impact evaluation methodologies

    New control architecturebased on PXI for a 3-finger haptic device applied to virtual manipulation

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    To perform advanced manipulation of remote environments such as grasping, more than one finger is required implying higher requirements for the control architecture. This paper presents the design and control of a modular 3-finger haptic device that can be used to interact with virtual scenarios or to teleoperate dexterous remote hands. In a modular haptic device, each module allows the interaction with a scenario by using a single finger; hence, multi-finger interaction can be achieved by adding more modules. Control requirements for a multifinger haptic device are analyzed and new hardware/software architecture for these kinds of devices is proposed. The software architecture described in this paper is distributed and the different modules communicate to allow the remote manipulation. Moreover, an application in which this haptic device is used to interact with a virtual scenario is shown

    Design and evaluation of an educational platform for implementing and testing bilateral control algorithms

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    This paper describes the design and evaluation of a new platform created in order to improve the learning experience of bilateral control algorithms in teleoperation. This experimental platform, developed at Universidad Politécnica de Madrid, is used by the students of the Master on Automation and Robotics in the practices of the subject called “Telerobotics and Teleoperation”. The main objective is to easily implement different control architectures in the developed platform and evaluate them under different conditions to better understand the main advantages and drawbacks of each control scheme. So, the student’s tasks are focused on adjusting the control parameters of the predefined controllers and designing new ones to analyze the changes in the behavior of the whole system. A description of the subject, main topics and the platform constructed are detailed in the paper. Furthermore, the methodology followed in the practices and the bilateral control algorithms are presented. Finally, the results obtained in the experiments with students are also shown

    Two-Hand Virtual Object Manipulation Based on Networked Architecture

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    A setup for bimanual virtual object manipulation is described in this paper. Index and thumb fingers are inserted in the corresponding thimbles in order to perform virtual object manipulations. A gimble, with 3-rotational degrees of freedom, connects each thimble to the corresponding serial-parallel mechanical structure with 3 actuated DoF. As a result, each finger has 6 DoF, movements and forces can be reflected in any direction without any torque component. Scenarios for virtual manipulation are based on distributed architecture where each finger device has its own real-time controller. A computer receives the status of each finger and runs a simulation with the virtual object manipulation. The information of the Scenario is updated at a rate of 200 Hz. The information from the haptic controller is processed at 1 kHz; it provides a good realism for object manipulation

    Mechanical design optimization for multi-finger haptic devices applied to virtual grasping manipulation

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    This paper describes the design of a modular multi-finger haptic device for virtual object manipulation. Mechanical structures are based on one module per finger and can be scaled up to three fingers. Mechanical configurations for two and three fingers are based on the use of one and two redundant axes, respectively. As demonstrated, redundant axes significantly increase workspace and prevent link collisions, which is their main asset with respect to other multi-finger haptic devices. The location of redundant axes and link dimensions have been optimized in order to guarantee a proper workspace, manipulability, force capability, and inertia for the device. The mechanical haptic device design and a thimble adaptable to different finger sizes have also been developed for virtual object manipulation

    Virulence in Mice of a Toxoplasma gondii Type II Isolate Does Not Correlate With the Outcome of Experimental Infection in Pregnant Sheep

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    [EN] Toxoplasma gondii is an apicomplexan parasite that infects almost all warm-blooded animals. Little is known about how the parasite virulence in mice extrapolates to other relevant hosts. In the current study, in vitro phenotype and in vivo behavior in mice and sheep of a type II T. gondii isolate (TgShSp1) were compared with the reference type II T. gondii isolate (TgME49). The results of in vitro assays and the intraperitoneal inoculation of tachyzoites in mice indicated an enhanced virulence for the laboratory isolate, TgME49, compared to the recently obtained TgShSp1 isolate. TgShSp1 proliferated at a slower rate and had delayed lysis plaque formation compared to TgME49, but it formed more cyst-like structures in vitro. No mortality was observed in adult mice after infection with 1-105 tachyzoites intraperitoneally or with 25-2,000 oocysts orally of TgShSp1. In sheep orally challenged with oocysts, TgME49 infection resulted in sporadically higher rectal temperatures and higher parasite load in cotyledons from ewes that gave birth and brain tissues of the respective lambs, but no differences between these two isolates were found on fetal/lamb mortality or lesions and number of T. gondii-positive lambs. The congenital infection after challenge at mid-pregnancy with TgShSp1, measured as offspring mortality and vertical transmission, was different depending on the challenged host. In mice, mortality in 50% of the pups was observed when a dam was challenged with a high oocyst dose (500 TgShSp1 oocysts), whereas in sheep infected with the same dose of oocysts, mortality occurred in all fetuses. Likewise, mortality of 9 and 27% of the pups was observed in mice after infection with 100 and 25 TgShSp1 oocysts, respectively, while in sheep, infection with 50 and 10 TgShSp1 oocysts triggered mortality in 68 and 66% of the fetuses/lambs. Differences in vertical transmission in the surviving offspring were only found with the lower oocyst doses (100% after infection with 10 TgShSp1 oocysts in sheep and only 37% in mice after infection with 25 TgShSp1 oocysts). In conclusion, virulence in mice of T. gondii type II isolates may not be a good indicator to predict the outcome of infection in pregnant sheepSIRS-S is supported by a fellowship from the Spanish Ministry of Education, Culture, and Sports (MECD), as a part of the Program of Training of University Teaching Staff (FPU, grant number FPU13/03438) and a mobility grant for predoctoral short stays in R+D centers (EST16/0719). DG-E is the recipient of a postdoctoral contract from the Junta de Castilla y León, partially funded by the European Social Fund (European Union). NA-V is the recipient of a predoctoral contract from the Ministerio de Economía, Industria y Competitividad (Ref. BES-2016-076513). This work was supported by the Ministry of Economy and Competitiveness (AGL2016-75935-C2-1-R and C2-2-R), the Community of Madrid, Spain (PLATESA, S2013/ABI2906), Junta de Castilla y León (LE080U16), and a grant of the Swiss National Science Foundation to AH (project No. 310030_165782

    Identification of molecular biomarkers associated with disease progression in the testis of bulls infected with Besnoitia besnoiti

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    [EN]Breeding bulls infected with Besnoitia besnoiti may develop sterility during either acute or chronic infection. The aim of this study was to investigate the molecular pathogenesis of B. besnoiti infection with prognosis value in bull sterility. Accordingly, five well-characterized groups of naturally and experimentally infected males were selected for the study based on clinical signs and lesions compatible with B. besnoiti infection, serological results and parasite detection. A broad panel of molecular markers representative of endothelial activation and fibrosis was investigated and complemented with a histopathological approach that included conventional histology and immunohistochemistry. The results indicated the predominance of an intense inflammatory infiltrate composed mainly of resident and recruited circulating macrophages and to a lesser extent of CD3+ cells in infected bulls. In addition, a few biomarkers were associated with acute, chronic or subclinical bovine besnoitiosis. The testicular parenchyma showed a higher number of differentially expressed genes in natural infections (acute and chronic infections) versus scrotal skin in experimental infections (subclinical infection). In subclinical infections, most genes were downregulated except for the CCL24 and CXCL2 genes, which were upregulated. In contrast, the acute phase was mainly characterized by the upregulation of IL-1α, IL-6 and TIMP1, whereas in the chronic phase, the upregulation of ICAM and the downregulation of MMP13, PLAT and IL-1α were the most relevant findings. Macrophages could be responsible for the highest level of gene regulation in the testicular parenchyma of severely affected and sterile bulls, and all these genes could be prognostic markers of sterility.SIThis study was financed by the Spanish Ministry of Economy and Competitiveness (AGL-2016-75202-R), the Spanish Ministry of Science and Innovation (PID2019-103960RB-I00) and by the Community of Madrid (PLATESA P2018/ BAA-4370). DG-B was funded by the Spanish Ministry of Science through a Juan de la Cierva postdoctoral fellowship (FJCI-2016-27875). CD-D was financially supported through a grant from the Spanish Ministry of Economy and Competitiveness (BES-2014-069839) and AJ-M through a grant from the Spanish Ministry of Education, Culture and Sports (FPU, Grant Number FPU13/05481). I. Ferre, L.M. Ortega Mora y G. Álvarez-García are part of the TOXOSOURCES consortium, supported by funding from the European Union’s Horizon 2020 Research and Innovation programme under grant agreement No 773830: One Health European Joint Programme. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Analysis of local and peripheral immune response developed in sheep experimentally infected with Toxoplasma gondii at different times of gestation

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    Trabajo presentado al: 4th International Meeting on Apicomplexa in Farm Animals. (11-14 October 2017 - Madrid, Spain).Toxoplasmosis is one the main infectious causes of reproductive failure in sheep where the time of gestation when sheep are infected affects the clinical and lesional outcome of the disease. In order to investigate the variations of local and peripheral immune responses during gestation, pregnant sheep were infected at early, mid and late gestation and subsequently culled at 2, 3 and 4 weeks post infection. In those sheep inoculated during the second term, serological antibodies were detected earlier and the increase in serological γ-IFN was higher than in the other infected animals. Regarding the local immune response at the placenta, infiltration of inflammatory cells was mainly found in the maternal septa, although it also invaded foetal mesenchyme adjacent to the lesions. The increase in the number of T lymphocytes was observed only in ewes infected during the second and last terms of gestation while the increase of B cells occurred in sheep infected at the first and second terms. The expression of iba-1 antigen by macrophages was more frequent after infection during the first term whereas macrophages expressing lysozyme, CD163 or calprotectin were more frequent in infections at mid-gestation. A significant increase in the transcription of γ-IFN, when compared to control animals, occurred after infections in the first and second term, while TNF-α and IL-10 transcription increased only in the second and last term, respectively. There were no differences when comparing transcription of cytokines between animals infected at different terms of gestation. This study shows that the time of gestation when infection occurs has a clear influence over the pathogenesis of ovine toxoplasmosis as a greater inflammatory response was found after inoculating sheep at the second term of gestation. This finding may explain the later invasion of the placenta by the parasite at early and mid gestation described in previous studies.This study was founded by AGL2016-75935-C2-2-R and LE080U16 research grants.Peer Reviewe
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