196 research outputs found
CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS
Context. CARMENES is a stabilised, high-resolution, double-channel
spectrograph at the 3.5 m Calar Alto telescope. It is optimally designed for
radial-velocity surveys of M dwarfs with potentially habitable Earth-mass
planets. Aims. We prepare a list of the brightest, single M dwarfs in each
spectral subtype observable from the northern hemisphere, from which we will
select the best planet-hunting targets for CARMENES. Methods. In this first
paper on the preparation of our input catalogue, we compiled a large amount of
public data and collected low-resolution optical spectroscopy with CAFOS at the
2.2 m Calar Alto telescope for 753 stars. We derived accurate spectral types
using a dense grid of standard stars, a double least-squares minimisation
technique, and 31 spectral indices previously defined by other authors.
Additionally, we quantified surface gravity, metallicity, and chromospheric
activity for all the stars in our sample. Results. We calculated spectral types
for all 753 stars, of which 305 are new and 448 are revised. We measured
pseudo-equivalent widths of Halpha for all the stars in our sample, concluded
that chromospheric activity does not affect spectral typing from our indices,
and tabulated 49 stars that had been reported to be young stars in open
clusters, moving groups, and stellar associations. Of the 753 stars, two are
new subdwarf candidates, three are T Tauri stars, 25 are giants, 44 are K
dwarfs, and 679 are M dwarfs. Many of the 261 investigated dwarfs in the range
M4.0-8.0 V are among the brightest stars known in their spectral subtype.
Conclusions. This collection of low-resolution spectroscopic data serves as a
candidate target list for the CARMENES survey and can be highly valuable for
other radial-velocity surveys of M dwarfs and for studies of cool dwarfs in the
solar neighbourhood.Comment: A&A, in pres
A search for He I airglow emission from the hot Jupiter tau Boo b
The helium absorption line at 10830 {\AA}, originating from the metastable
triplet state 2S, has been suggested as an excellent probe for the extended
atmospheres of hot Jupiters and their hydrodynamic escape processes, and has
recently been detected in the transmission spectra of a handful of planets. The
isotropic re-emission will lead to helium airglow that may be observable at
other orbital phases. The goal of this paper is to investigate the
detectability of He I emission at 10830 {\AA} in the atmospheres of exoplanets
using high-resolution spectroscopy, providing insights into the properties of
the upper atmospheres of close-in gas giants. We estimated the expected
strength of He I emission in hot Jupiters based on their transmission signal.
We searched for the He I 10830 {\AA} emission feature in tau Boo b in three
nights of high-resolution spectra taken by CARMENES at the 3.5m Calar Alto
telescope. The spectra from each night were corrected for telluric absorption,
sky emission lines, and stellar features, and were shifted to the planetary
rest frame to search for the emission. The He I emission is not detected in tau
Boo b, reaching a 5 sigma contrast limit of 410 for emission
line widths above 20 km/s. This is roughly a factor of 8 above the expected
level of emission (assuming a typical He I transit absorption of 1% for hot
Jupiters). This suggests that targeting the He I emission with well-designed
observations using upcoming instruments such as VLT/CRIRES+ and E-ELT/HIRES is
possible.Comment: Accepted for publication in A&A; 9 pages, 9 figure
O humor em manuais escolares de matemática
O humor tem larga presença na vida das pessoas, combinando elementos afetivos e cognitivos com o intuito de bem-dispor. Para além dos contextos de lazer, o humor tem também sido utilizado em contextos associados ao trabalho, nomeadamente nas escolas, colocado ao serviço do ensino. Sendo os manuais escolares um recurso muito utilizado pelos professores, particularmente pelos de Matemática, pareceu-nos pertinente: (i) averiguar a utilização do humor em manuais escolares de Matemática; e (ii) descrever o humor utilizado nos manuais, discutindo o seu enquadramento didático. Para isso, submetemos a análise de conteúdo quatro manuais escolares de Matemática (dos 4.º e 5.º anos de escolaridade) com larga difusão nacional. Os resultados revelam que o humor, tanto no texto como na ilustração, não tem praticamente expressão nos manuais. Ainda assim, todos os manuais valorizam, ao nÃvel da ilustração, situações de boa disposição, apresentando, recorrentemente, pessoas a rir.Humor has a wide presence in people's lives, combining affective and cognitive elements with the intention of well-being. In addition to the leisure contexts, humor has also been used in contexts associated with work, namely schools, placed at the service of teaching. Since school textbooks are a resource widely used by teachers, particularly those of mathematics, it seems pertinent to us: (I) to access the usage of humor in Mathematics school textbooks; and (ii) describe the humor used in textbooks and discuss their didactic framework. For this, we submitted, to content analysis, four textbooks of Mathematics (of the 4th and 5th grades) with wide national diffusion. The results reveal that humor, both in the text and in the illustration, has practically no expression in the textbooks. Even so, all textbooks value, at the illustration level, light-hearted situations, presenting repeatedly, people laughing.info:eu-repo/semantics/publishedVersio
Detection of He I \AA{} absorption on HD 189733 b with CARMENES high-resolution transmission spectroscopy
We present three transit observations of HD 189733 b obtained with the
high-resolution spectrograph CARMENES at Calar Alto. A strong absorption signal
is detected in the near-infrared He I triplet at 10830 \AA{} in all three
transits. During mid-transit, the mean absorption level is %
measured in a 10 km s range at a net blueshift of km
s (10829.84--10830.57 \AA{}). The absorption signal exhibits radial
velocities of km s and km s during
ingress and egress, respectively; measured in the planetary rest frame. We show
that stellar activity related pseudo-signals interfere with the planetary
atmospheric absorption signal. They could contribute as much as 80% of the
observed signal and might also affect the radial velocity signature, but
pseudo-signals are very unlikely to explain the entire signal. The observed
line ratio between the two unresolved and the third line of the He I triplet is
, which strongly deviates from the value expected for an optically
thin atmospheres. When interpreted in terms of absorption in the planetary
atmosphere, this favors a compact helium atmosphere with an extent of only 0.2
planetary radii and a substantial column density on the order of cm. The observed radial velocities can be understood either in
terms of atmospheric circulation with equatorial superrotation or as a sign of
an asymmetric atmospheric component of evaporating material. We detect no clear
signature of ongoing evaporation, like pre- or post-transit absorption, which
could indicate material beyond the planetary Roche lobe, or radial velocities
in excess of the escape velocity. These findings do not contradict planetary
evaporation, but only show that the detected helium absorption in HD 189733 b
does not trace the atmospheric layers that show pronounced escape signatures.Comment: 13 pages, 12 figures, accepted for publication in A&
Efficacy of conventional treatment with composite resin and atraumatic restorative treatment in posterior primary teeth: study protocol for a randomised controlled trial
Introduction Despite the widespread acceptance of
conventional treatment using composite resin in primary
teeth, there is limited evidence that this approach is the
best option in paediatric clinics. Atraumatic restorative
treatment (ART) using high-viscosity glass ionomer
cement has gradually become more popular because it
performs well in clinical studies, is easy to handle and
is patient friendly. Therefore, the aim of this randomised
clinical trial study is to compare the restoration longevity
of conventional treatment using composite resin with that
of ART in posterior primary teeth. As secondary outcomes,
cost-efficacy and patient self-reported discomfort will also
be tested.
Methods and analysis Children aged 3–6 years
presenting with at least one occlusal and/or occlusalproximal cavity will be randomly assigned to one of
two groups according to the dental treatment: ART
(experimental group) or composite resin restoration
(control group). The dental treatment will be performed
at a dental care trailer located in an educational complex
in Barueri/SP, Brazil. The unit of randomisation will be the
child. A sample size of 240 teeth with occlusal cavities
and 188 teeth with occlusal-proximal cavities has been
calculated. The primary outcome will be restoration
longevity, which will be clinically assessed after 6, 12,
18 and 24 months by two examiners. The duration of the
dental treatment and the cost of all materials used will
be considered when estimating the cost-efficacy of each
treatment. Individual discomfort will be measured after
each dental procedure using the Facial Scale of WongBaker.
Ethics and dissemination This clinical trial was
approved by the local ethics committee from the
Faculty of Dentistry of the University of São Paulo
(registration no. 1.556.018). Participants will be
included after their legal guardians have signed an
informed consent form containing detailed information
about the research
Morte súbita e angina vasoespástica
Variant angina is defined by chest pain occurring at rest associated with transitory ST segment elevation on ECG, and is caused by a spasm of a coronary artery. Frequently, variant angina is associated with atherosclerotic coronary obstruction and patients with normal coronary arteries are rare. Patients with variant angina and normal coronary arteries have good prognosis, and the development of ventricular arrhythmias or sudden death is rare. The authors present two cases of sudden cardiac death in patients with variant angina and normal coronary arteries
Water vapor detection in the transmission spectra of HD 209458 b with the CARMENES NIR channel
Aims: We aim at detecting HO in the atmosphere of the hot Jupiter HD
209458 b and perform a multi-band study in the near infrared with CARMENES.
Methods: The HO absorption lines from the planet's atmosphere are
Doppler-shifted due to the large change in its radial velocity during transit.
This shift is of the order of tens of km s, whilst the Earth's telluric
and the stellar lines can be considered quasi-static. We took advantage of this
to remove the telluric and stellar lines using SYSREM, a principal component
analysis algorithm. The residual spectra contain the signal from thousands of
planetary molecular lines well below the noise level. We retrieve this
information by cross-correlating the spectra with models of the atmospheric
absorption.
Results: We find evidence of HO in HD 209458 b with a signal-to-noise
ratio (S/N) of 6.4. The signal is blueshifted by --5.2 km
s, which, despite the error bars, is a firm indication of day-to-night
winds at the terminator of this hot Jupiter. Additionally, we performed a
multi-band study for the detection of HO individually from the three NIR
bands covered by CARMENES. We detect HO from its 1.0 m band with a S/N
of 5.8, and also find hints from the 1.15 m band, with a low S/N of 2.8.
No clear planetary signal is found from the 1.4 m band.
Conclusions: Our significant signal from the 1.0 m band in HD 209458 b
represents the first detection of HO from this band, the bluest one to
date. The unfavorable observational conditions might be the reason for the
inconclusive detection from the stronger 1.15 and 1.4 m bands. HO is
detected from the 1.0 m band in HD 209458 b, but hardly in HD 189733 b,
which supports a stronger aerosol extinction in the latter.Comment: 11 pages, 10 figures; accepted for publication in A&
Water vapour detection in hot Jupiters with the CARMENES NIR channel
Stars and planetary system
Association of alpha1a-adrenergic receptor polymorphism and blood pressure phenotypes in the Brazilian population
Background: The alpha1A-adrenergic receptor (alpha(1A)-AR) regulates the cardiac and peripheral vascular system through sympathetic activation. Due to its important role in the regulation of vascular tone and blood pressure, we aimed to investigate the association between the Arg347Cys polymorphism in the alpha(1A)-AR gene and blood pressure phenotypes, in a large sample of Brazilians from an urban population. Methods: A total of 1568 individuals were randomly selected from the general population of the Vitoria City metropolitan area. Genetic analysis of the Arg347Cys polymorphism was conducted by polymerase chain reaction/restriction fragment length polymorphism. We have compared cardiovascular risk variables and genotypes using ANOVA, and Chi-square test for univariate comparisons and logistic regression for multivariate comparisons. Results: Association analysis indicated a significant difference between genotype groups with respect to diastolic blood pressure (p = 0.04), but not systolic blood pressure (p = 0.12). In addition, presence of the Cys/Cys genotype was marginally associated with hypertension in our population (p = 0.06). Significant interaction effects were observed between the studied genetic variant, age and physical activity. Presence of the Cys/Cys genotype was associated with hypertension only in individuals with regular physical activity (odds ratio = 1.86; p = 0.03) or younger than 45 years (odds ratio = 1.27; p = 0.04). Conclusion: Physical activity and age may potentially play a role by disclosing the effects of the Cys allele on blood pressure. According to our data it is possible that the Arg347Cys polymorphism can be used as a biomarker to disease risk in a selected group of individuals.FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo)[2001/03454-5
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