633 research outputs found
Unconventional health practices by family and affective bonds of critic patients
Objective: To investigate the applicability of unconventional practices in health performed by visitors with affective bonds and/or family members of critically ill patients. Methods: A descriptive and quantitative study was carried out in care environments to critically ill patients from the Emergency and Trauma State's Hospital in the city of João Pessoa - Paraiba. The sample consisted of 100 families. Data were collected through semistructured interviews and analyzed by the Statistical Package for Social Sciences software. Approved by the Research Ethics Committee under number 328.320. Results: It was observed applicability, knowledge and good acceptance in the use of some unconventional practices by family and by people with emotional bonds with critically ill patients. Conclusion: The unconventional practices provide comprehensive care to the individual, to the family and to affective bonds. Family and affective bonds convey a great reliability of these practices, recognizing them and integrating them is a key component to the influence of its use
Політична система гортистської Угорщини: історико-правовий аспект
Розглядається історико правовий аспект функціонування політичної системи гортистської Угорщини. Проаналізувавши її основні базові характеристики автор робить
висновок про її авторитарне, а не тоталітарне спрямування та відсутність в ній
сутнісних ознак військової диктатури.
Ключові слова: політична система, авторитаризм, тоталітаризм, військова диктатура.Статья посвящена историко правовым аспектам функционирования политической системы хортистской Венгрии. Проанализировав ее основные базовые характеристики, автор делает вывод про ее авторитарную, а не тоталитарную направленность и отсутствие в ней сущностных признаков военной диктатуры.
Ключевые слова: политическая система, авторитаризм, тоталитаризм, военная
диктатура.The article is devoted to the historical legal aspect of chartist power realization in the
period from 1939 up to 1944 in Transcarpathia (as a part of Hungarian state). Analyzing some
normative and archive documents, the author makes a conclusion about its authoritarian but
not totalitarian direction and the main features of military dictatorship absence.
Key words: political system, authoritarianism, totalitarianism, military dictatorship
Predictions for mass-loss rates and terminal wind velocities of massive O-type stars
Mass loss forms an important aspect of the evolution of massive stars, as
well as for the enrichment of the surrounding ISM. Our goal is to predict
accurate mass-loss rates and terminal wind velocities. These quantities can be
compared to empirical values, thereby testing radiation-driven wind models. One
specific issue is that of the "weak-wind problem", where empirically derived
mass-loss rates fall orders of magnitude short of predicted values. We employ
an established Monte Carlo model and a recently suggested new line acceleration
formalism to solve the wind dynamics consistently. We provide a new grid of
mass-loss rates and terminal wind velocities of O stars, and compare the values
to empirical results. Our models fail to provide mass-loss rates for
main-sequence stars below a luminosity of log(L/Lsun) = 5.2, where we run into
a fundamental limit. At luminosities below this critical value there is
insufficient momentum transferred in the region below the sonic point to
kick-start the acceleration. This problem occurs at the location of the onset
of the weak-wind problem. For O dwarfs, the boundary between being able to
start a wind, and failing to do so, is at spectral type O6/O6.5. The direct
cause of this failure is a combination of the lower luminosity and a lack of Fe
V lines at the wind base. This might indicate that another mechanism is
required to provide the necessary driving to initiate the wind. For stars more
luminous than log(L/Lsun) = 5.2, our new mass-loss rates are in excellent
agreement with the mass-loss prescription by Vink et al. 2000. This implies
that the main assumption entering the method of the Vink et al. prescriptions -
i.e. that the momentum equation is not explicitly solved for - does not
compromise the reliability of the Vink et al. results for this part of
parameter space (Abridged).Comment: 10 pages, 10 figures, Astronomy & Astrophysics (in press
Testing the companion hypothesis for the origin of the X-ray emission from intermediate-mass main-sequence stars
There is no straightforward explanation for intrinsic X-ray emission from
intermediate-mass main-sequence stars. Therefore the observed emission is often
interpreted in terms of (hypothesized) late-type magnetically active companion
stars. We use Chandra imaging observations to spatially resolve in X-rays a
sample of main-sequence B-type stars with recently discovered companions at
arcsecond separation. We find that all spatially resolved companions are X-ray
emitters, but seven out of eleven intermediate-mass stars are also X-ray
sources. If this emission is interpreted in terms of additional sub-arcsecond
or spectroscopic companions, this implies a high multiplicity of B-type stars.
Firm results on B star multiplicity pending, the alternative, that B stars
produce intrinsic X-rays, can not be discarded. The appropriate scenario in
this vein is might be a magnetically confined wind, as suggested for the X-ray
emission of the magnetic Ap star IQ Aur. However, the only Ap star in the
Chandra sample is not detected in X-rays, and therefore does not support this
picture.Comment: 12 pages; accepted for publication in Astronomy & Astrophysic
New findings on the prototypical Of?p stars
In recent years several in-depth investigations of the three Galactic Of?p
stars were undertaken. These multiwavelength studies revealed the peculiar
properties of these objects (in the X-rays as well as in the optical): magnetic
fields, periodic line profile variations, recurrent photometric changes.
However, many questions remain unsolved. To clarify some of the properties of
the Of?p stars, we have continued their monitoring. A new XMM observation and
two new optical datasets were obtained. Additional information for the
prototypical Of?p trio has been found. HD108 has now reached its quiescent,
minimum-emission state, for the first time in 50--60yrs. The echelle spectra of
HD148937 confirm the presence of the 7d variations in the Balmer lines and
reveal similar periodic variations (though of lower amplitudes) in the HeI5876
and HeII4686 lines, underlining its similarities with the other two
prototypical Of?p stars. The new XMM observation of HD191612 was taken at the
same phase in the line modulation cycle but at a different orbital phase as
previous data. It clearly shows that the X-ray emission of HD191612 is
modulated by the 538d period and not the orbital period of 1542d - it is thus
not of colliding-wind origin and the phenomenon responsible for the optical
changes appears also at work in the high-energy domain. There are however
problems: our MHD simulations of the wind magnetic confinement predict both a
harder X-ray flux of a much larger strength than what is observed (the modeled
DEM peaks at 30-40MK, whereas the observed one peaks at 2MK) and narrow lines
(hot gas moving with velocities of 100--200km/s, whereras the observed FWHM is
~2000km/s).Comment: 10 pages, 8 figures (2 in jpg), accepted for publication by A&
Line profile variability in the spectra of Oef stars: II. HD192281, HD14442 and HD14434
We present the very first analysis of the spectroscopic variability of the
three rapidly rotating Oef stars HD192281 (O5(ef)), HD14442 (O5.5ef) and
HD14434 (O6.5(ef)). Radial velocities of the HeII lambda 4541 line reveal no
evidence of binarity on time scales of a few days, or from one year to the
next, for any of the targets. The HeII lambda 4686 double-peaked emission and,
to some extent, the Hbeta absorption line display significant profile
variability in the spectra of all three stars. Data gathered during different
observing runs spread over six years reveal a rather stable time scale for
HD192281 and HD14442, whereas the variability pattern changes significantly
from one year to the other. The case of HD14434 is less clear as no obvious
time scale emerges from our analysis. In a temptative way to interpret this
variability, stellar rotation remains a possible clock for HD192281 and
HD14442. However, currently available models addressing stellar rotation fail
to explain some crucial aspects of the observed variability behaviour, which
appear to be even more complex in the case of HD14434.Comment: 15 pages, 12 figures (8 postscript and 4 gif), accepted by A&
Searching for links between magnetic fields and stellar evolution. II. The evolution of magnetic fields as revealed by observations of Ap stars in open clusters and associations
The evolution of magnetic fields in Ap stars during the main sequence phase
is presently mostly unconstrained by observation because of the difficulty of
assigning accurate ages to known field Ap stars.
We are carrying out a large survey of magnetic fields in cluster Ap stars
with the goal of obtaining a sample of these stars with well-determined ages.
In this paper we analyse the information available from the survey as it
currently stands.
We select from the available observational sample the stars that are probably
(1) cluster or association members and (2) magnetic Ap stars. For the stars in
this subsample we determine the fundamental parameters T_eff, log(L/L_o), and
M/M_o. With these data and the cluster ages we assign both absolute age and
fractional age (the fraction of the main sequence lifetime completed). For this
purpose we have derived new bolometric corrections for Ap stars.
Magnetic fields are present at the surfaces of Ap stars from the ZAMS to the
TAMS. Statistically for the stars with M > 3 M_o the fields decline with
advancing age approximately as expected from flux conservation together with
increased stellar radius, or perhaps even faster than this rate, on a time
scale of about 3 10^7 yr. In contrast, lower mass stars show no compelling
evidence for field decrease even on a timescale of several times 10^8 yr.
Study of magnetic cluster stars is now a powerful tool for obtaining
constraints on evolution of Ap stars through the main sequence. Enlarging the
sample of known cluster magnetic stars, and obtaining more precise RMS fields,
will help to clarify the results obtained so far. Further field observations
are in progress.Comment: Accepted by Astronomy & Astrophysic
Microlensing of circumstellar envelopes III. Line profiles from stellar winds in homologous expansion
This paper examines line profile evolution due to the linear expansion of circumstellar material obsverved during a microlensing event. This work extends our previous papers on emission line profile evolution from radial and azimuthal flow during point mass lens events and fold caustic crossings. Both "flavours" of microlensing were shown to provide effective diagnostics of bulk motion in circumstellar envelopes. In this work a different genre of flow is studied, namely linear homologous expansion, for both point mass lenses and fold caustic crossings. Linear expansion is of particular relevance to the effects of microlensing on supernovae at cosmological distances. We derive line profiles and equivalent widths for the illustrative cases of pure resonance and pure recombination lines, modelled under the Sobolev approximation. The efficacy of microlensing as a diagnostic probe of the stellar environs is demonstrated and discussed
How does a flexible chain of active particles swell?
We study the swelling of a flexible linear chain composed of active particles
by analytical theory and computer simulation. Three different situations are
considered: a free chain, a chain confined to an external harmonic trap, and a
chain dragged at one end. First we consider an ideal chain with harmonic
springs and no excluded volume between the monomers. The Rouse model of
polymers is generalized to the case of self-propelled monomers and solved
analytically. The swelling, as characterized by the spatial extension of the
chain, scales with the monomer number defining a Flory exponent which is
in the three different situations. As a result, we find that
activity does not change the Flory exponent but affects the prefactor of the
scaling law. This can be quantitatively understood by mapping the system onto
an equilibrium chain with a higher effective temperature such that the chain
swells under an increase of the self-propulsion strength. We then use computer
simulations to study the effect of self-avoidance on active polymer swelling.
In the three different situations, the Flory exponent is now and again unchanged under self-propulsion. However, the chain extension
behaves non-monotonic in the self-propulsion strength.Comment: (9 pages, 5 figures
Looking for pulsations in HgMn stars through CoRoT lightcurves
HgMn Chemically Peculiar stars are among the quietest stars of the
main-sequence. However, according to theoretical predictions, these stars could
have pulsations related to the very strong overabundances of iron peak
elements, which are produced by atomic diffusion in upper layers. Such
pulsations have never been detected from ground based observations.
Our aim is to search for signatures of pulsations in HgMn stars using the
high quality lightcurves provided by the CoRoT satellite.
We identified three faint stars (V>12), from VLT-GIRAFFE multiobject
spectrograph survey in a field which was planned for observation by CoRoT. They
present the typical characteristics of HgMn stars. They were observed by the
CoRoT satellite during the long run (131 days) which started from the 24th of
October 2007, with the exoplanets CCD's (Additional Programme). In the present
work, we present the analysis of the ground based spectra of these three stars
and the analysis of the corresponding CoRoT lightcurves.
Two of these three HgMn candidates show low amplitude (less than 1.6 mmag)
periodic variations (4.3 and 2.53 days respectively, with harmonics) which are
compatible with periods predicted by theoretical models.Comment: Accepted paper in A&A (7 May 2009
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