21,266 research outputs found

    El aborto. Análisis crítico de la situación actual

    Get PDF
    The author begins this work by making an exposition of those facts which we could call fundamental from the biological point of view to understand and judge the different birth control methods in use today. From the very moment of the fertilization of the ovum by the spermatozoid. the development plans of a new organism become imprinted. This new organism is endowed with an extraordinary functional capacity whose determination is unaffected by the relations between the maternal organism and the fetal organismo These facts are so apparent that. Jf the beginning of Iife is not located in fecundation . there exist no concrete re· ferences as to when it does in fact take place. Abortive birth control methods are those which interrupt embryonic -or fetal- development. no matter the mechanism of action employed nor the time elapsed since the fertilization of the ovum. The spreading of these abortive methods has been noteworthy. with the proliferation of contraceptive methods -mainly the hormonal ones (the «pill .. )which have served as the key which has opened the door for abortion. Jt can be demonstrated how in these last fifteen years the relation between contraceptives and abortion is indeed intimate, and it beco mes difficult to separate them in practice. The laws promulgated in a large number of countries in recent years approving abortion have created in the public at large a conceptual confusion which makes that «Iegalized», .inducedD, «provoked», «criminal» ... abortions become differentiated only with sorne difficulty, whereas in point of fact the differences are quite c1ear. The only abortion which can be conside'red legal is spontaneous abortion (miscarriage) which occurs independently of the will of the mother and that of the doctor; all other cases deal with provoked abortion and signify the direct death of an individual. Jt is no doubt true that juridical legality do es not necessarily identify itself with ethical norms and that it cannot be the fundament of doctrinal norms of conduct; it is precisely from this that even «Iegalized» abortion continues to be a crime. Finally, the author makes reference to the relations between abortion and euthanasia which are increasing evident as time goes by. It is foreseeable that in the next few years the first laws allowing euthanasia will be approved, signifying yet a further step in the escalation of the anti-life movement

    HD 85567: A Herbig B[e] star or an interacting B[e] binary

    Full text link
    Context. HD 85567 is an enigmatic object exhibiting the B[e] phenomenon, i.e. an infrared excess and forbidden emission lines in the optical. The object's evolutionary status is uncertain and there are conflicting claims that it is either a young stellar object or an evolved, interacting binary. Aims. To elucidate the reason for the B[e] behaviour of HD 85567, we have observed it with the VLTI and AMBER. Methods. Our observations were conducted in the K-band with moderate spectral resolution (R~1500, i.e. 200 km/s). The spectrum of HD 85567 exhibits Br gamma and CO overtone bandhead emission. The interferometric data obtained consist of spectrally dispersed visibilities, closure phases and differential phases across these spectral features and the K-band continuum. Results. The closure phase observations do not reveal evidence of asymmetry. The apparent size of HD 85567 in the K-band was determined by fitting the visibilities with a ring model. The best fitting radius, 0.8 +/- 0.3 AU, is relatively small making HD 85567 undersized in comparison to the size-luminosity relationship based on YSOs of low and intermediate luminosity. This has previously been found to be the case for luminous YSOs, and it has been proposed that this is due to the presence of an optically thick gaseous disc. We demonstrate that the differential phase observations over the CO bandhead emission are indeed consistent with the presence of a compact (~1 AU) gaseous disc interior to the dust sublimation radius. Conclusions. The observations reveal no sign of binarity. However, the data do indicate the presence of a gaseous disc interior to the dust sublimation radius. We conclude that the data are consistent with the hypothesis that HD 85567 is a YSO with an optically thick gaseous disc within a larger dust disc that is being photo-evaporated from the outer edge.Comment: Accepted for publication in A &

    Spatially resolved H_2 emission from a very low-mass star

    Full text link
    Molecular outflows from very low-mass stars (VLMSs) and brown dwarfs have been studied very little. So far, only a few CO outflows have been observed, allowing us to map the immediate circumstellar environment. We present the first spatially resolved H2 emission around IRS54 (YLW52), a ~0.1-0.2 Msun Class I source. By means of VLT SINFONI K-band observations, we probed the H2 emission down to the first ~50 AU from the source. The molecular emission shows a complex structure delineating a large outflow cavity and an asymmetric molecular jet. Thanks to the detection of several H2 transitions, we are able to estimate average values along the jet-like structure (from source position to knot D) of Av~28 mag, T~2000-3000 K, and H2 column density N(H2)~1.7x10^17 cm^-2. This allows us to estimate a mass loss rate of ~2x10^-10 Msun/yr for the warm H2 component . In addition, from the total flux of the Br Gamma line, we infer an accretion luminosity and mass accretion rate of 0.64 Lsun and ~3x10^-7 Msun/yr, respectively. The outflow structure is similar to those found in low-mass Class I and CTTS. However, the Lacc/Lbol ratio is very high (~80%), and the mass accretion rate is about one order of magnitude higher when compared to objects of roughly the same mass, pointing to the young nature of the investigated source.Comment: accepted as a Letter in A&

    Solutions of the divergence and Korn inequalities on domains with an external cusp

    Get PDF
    This paper deals with solutions of the divergence for domains with external cusps. It is known that the classic results in standard Sobolev spaces, which are basic in the variational analysis of the Stokes equations, are not valid for this class of domains. For some bounded domains Ω⊂Rn\Omega\subset{\mathbb R}^n presenting power type cusps of integer dimension m≤n−2m\le n-2, we prove the existence of solutions of the equation divu=f{div}{\bf u}=f in weighted Sobolev spaces, where the weights are powers of the distance to the cusp. The results obtained are optimal in the sense that the powers cannot be improved. As an application, we prove existence and uniqueness of solutions of the Stokes equations in appropriate spaces for cuspidal domains. Also, we obtain weighted Korn type inequalities for this class of domains

    Implications of a Sub-Threshold Resonance for Stellar Beryllium Depletion

    Get PDF
    Abundance measurements of the light elements lithium, beryllium, and boron are playing an increasingly important role in the study of stellar physics. Because these elements are easily destroyed in stars at temperatures 2--4 million K, the abundances in the surface convective zone are diagnostics of the star's internal workings. Standard stellar models cannot explain depletion patterns observed in low mass stars, and so are not accounting for all the relevant physical processes. These processes have important implications for stellar evolution and primordial lithium production in big bang nucleosynthesis. Because beryllium is destroyed at slightly higher temperatures than lithium, observations of both light elements can differentiate between the various proposed depletion mechanisms. Unfortunately, the reaction rate for the main destruction channel, 9Be(p,alpha)6Li, is uncertain. A level in the compound nucleus 10B is only 25.7 keV below the reaction's energetic threshold. The angular momentum and parity of this level are not well known; current estimates indicate that the resonance entrance channel is either s- or d-wave. We show that an s-wave resonance can easily increase the reaction rate by an order of magnitude at temperatures of approximately 4 million K. Observations of sub-solar mass stars can constrain the strength of the resonance, as can experimental measurements at lab energies lower than 30 keV.Comment: 9 pages, 1 ps figure, uses AASTeX macros and epsfig.sty. Reference added, typos corrected. To appear in ApJ, 10 March 199

    Phenomenology Tools on Cloud Infrastructures using OpenStack

    Get PDF
    We present a new environment for computations in particle physics phenomenology employing recent developments in cloud computing. On this environment users can create and manage "virtual" machines on which the phenomenology codes/tools can be deployed easily in an automated way. We analyze the performance of this environment based on "virtual" machines versus the utilization of "real" physical hardware. In this way we provide a qualitative result for the influence of the host operating system on the performance of a representative set of applications for phenomenology calculations.Comment: 25 pages, 12 figures; information on memory usage included, as well as minor modifications. Version to appear in EPJ

    Transvaginal color Doppler assessment of venous flow in adnexal masses

    Get PDF
    Objective To analyze the usefulness of transvaginal color Doppler assessment of venous flow in the differential diagnosis of adnexal masses. Material and Methods Ninety-one consecutive patients (mean age: 46.6 years, range: 16–81 years) diagnosed as having an adnexal mass were evaluated by transvaginal color Doppler sonography prior to surgery. Color Doppler was used to detect and analyze the flow velocity waveform from arterial and venous blood flow within the tumor. For arterial signals the resistance index and peak systolic velocity, and for veins the maximum venous flow velocity, were calculated. Receiver operator characteristic curves were plotted to determine the best venous flow velocity cut-off. According to our previous study using arterial Doppler, a tumor was considered as malignant when flow was detected and the lowest resistance index was ≤ 0.45. Using venous Doppler a mass was considered as malignant when flow was detected and the venous flow velocity was ≥ the best cut-off found on the receiver operator characteristic curve. Definitive histopathological diagnosis was obtained in all cases. Sensitivity, specificity, positive predictive value and negative predictive value for B-mode morphology (evaluation performed according to Sassone’s scoring system), arterial Doppler, venous Doppler, and a combination of both arterial and venous Doppler were calculated. Results Twenty-five masses (27.5%) were malignant and 66 (72.5%) benign. Arterial and venous flow was found more frequently in malignant than in benign masses (92% vs. 41% (P < 0.001) and 72% vs. 21% (P < 0.001), respectively). The resistance index was significantly lower in malignant tumors (0.42 vs. 0.60, P = 0.0003). No differences were found in peak systolic velocity. Venous flow velocity was significantly higher in malignant masses (18.1 cm/s vs. 8.9 cm/s, P = 0.0006). The best cut-off of venous flow velocity was 10 cm/s. Sensitivity, specificity, positive predictive value and negative predictive value for morphology, arterial Doppler, venous Doppler, and the combination of both arterial and venous Doppler were 92%, 71%, 45%, 96%; 76%, 95%, 87%, 91%; 68%, 94%, 81%, 89%; and 88%, 91%, 79%, 95%, respectively. Conclusions Our results indicate that preoperative evaluation by venous flow assessment of adnexal masses may be useful to discriminate between malignant and benign tumors

    Scientific power in the Spanish press during the pandemic: a portrait of new leaders while explaining its risk

    Get PDF
    This work is based on the mediatisation of society theory, which establishes more attached importance and the presence of the mass media as mediators in various social processes, as well as on Production Studies, that analyse creative skills to draw an audience, to apply these theories to the media representation of the COVID-19 pandemic. The objective is to analyse how the generalist media have represented male/female scientists, who have become social benchmarks during the first COVID-19 wave in Spain. Our initial hypothesis considers that the purpose of the mediatisation of scientific discourse was to contribute answers to, and to keep society calm, in an uncertainty context. By content and discourse analyses with a sample formed by 172 pieces of work published between 25 January and 5 July 2020 in four Spanish digital newspapers, we observed how these specialists not only became the usual sources of journalistic information but were also the main leading figures in them. The mass media pay attention to their statements, but also to their aesthetics and communication style, which are singular compared to conventional power to date. Science enters the national section with its own image and explanatory intentionality. Nonetheless, constant overexposure and its link with governments making controversial decisions influence the image held by the public opinion of scientists with time, which dissociates them from its knowledge and identifies them with political power.Este trabajo parte de la teoría de la mediatización de la sociedad, que establece el aumento de la importancia y presencia de los medios de comunicación como mediadores en diversos procesos sociales, así como de los Estudios de Producción, que analizan las habilidades creativas para atraer a la audiencia, para aplicarla a la representación mediática de la pandemia de COVID-19. El objetivo es analizar cómo medios generalistas han representado a los y las científicas convertidos en referentes sociales durante la primera ola en España. Nuestra hipótesis de partida considera que la mediatización del discurso científico ha tenido como propósito aportar respuestas y tranquilidad a la sociedad en un contexto de incertidumbre. A través del análisis de contenido y del análisis del discurso de una muestra formada por 172 piezas publicadas entre el 25 de enero y el 5 de julio de 2020en cuatro diarios digitales españoles, se observa que estos especialistas no solo se han convertido en fuentes habituales de las informaciones periodísticas, sino que en ocasiones incluso las protagonizan. Los medios de comunicación prestan atención a sus declaraciones, pero también a su estética y estilo de comunicación, singular frente al poder convencional hasta ahora. La ciencia entra en la sección de Nacional con imagen propia e intencionalidad explicativa. No obstante, la sobreexposición continua y el vínculo con gobiernos que toman decisiones polémicas influye con el paso del tiempo en la imagen que la opinión pública genera de los científicos, los desvincula de su conocimiento y los identifica con el poder político
    • …
    corecore