22,460 research outputs found
El aborto. Análisis crÃtico de la situación actual
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
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
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
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 presenting power type
cusps of integer dimension , we prove the existence of solutions of
the equation 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
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
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
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
Corto: A lightweight R package for gene network inference and master regulator analysis
Motivation: Gene network inference and master regulator analysis (MRA) have been widely adopted to define specific transcriptional perturbations from gene expression signatures. Several tools exist to perform such analyses but most require a computer cluster or large amounts of RAM to be executed.Results: We developed corto, a fast and lightweight R package to infer gene networks and perform MRA from gene expression data, with optional corrections for copy-number variations and able to run on signatures generated from RNA-Seq or ATAC-Seq data. We extensively benchmarked it to infer context-specific gene networks in 39 human tumor and 27 normal tissue datasets
Scientific power in the Spanish press during the pandemic: a portrait of new leaders while explaining its risk
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 teorÃa 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, asà 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 cientÃficas convertidos en referentes sociales durante la primera ola en España. Nuestra hipótesis de partida considera que la mediatización del discurso cientÃfico 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 periodÃsticas, 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 vÃnculo con gobiernos que toman decisiones polémicas influye con el paso del tiempo en la imagen que la opinión pública genera de los cientÃficos, los desvincula de su conocimiento y los identifica con el poder polÃtico
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