196 research outputs found

    CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS

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    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

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    The helium absorption line at 10830 {\AA}, originating from the metastable triplet state 23^3S, 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 4×\times10−4^{-4} 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

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    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 nível 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 λ10830\lambda10830 \AA{} absorption on HD 189733 b with CARMENES high-resolution transmission spectroscopy

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    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 0.88±0.040.88\pm0.04 % measured in a ±\pm10 km s−1^{-1} range at a net blueshift of −3.5±0.4-3.5\pm0.4 km s−1^{-1} (10829.84--10830.57 \AA{}). The absorption signal exhibits radial velocities of +6.5±3.1+6.5\pm3.1 km s−1^{-1} and −12.6±1.0-12.6\pm1.0 km s−1^{-1} 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 2.8±0.22.8\pm0.2, 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 4×10124\times 10^{12} cm−2^{-2}. 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

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    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

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    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

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    Aims: We aim at detecting H2_2O in the atmosphere of the hot Jupiter HD 209458 b and perform a multi-band study in the near infrared with CARMENES. Methods: The H2_2O 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−1^{-1}, 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 H2_2O in HD 209458 b with a signal-to-noise ratio (S/N) of 6.4. The signal is blueshifted by --5.2 −1.3+2.6^{+2.6}_{-1.3} km s−1^{-1}, 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 H2_2O individually from the three NIR bands covered by CARMENES. We detect H2_2O from its 1.0 μ\mum band with a S/N of 5.8, and also find hints from the 1.15 μ\mum band, with a low S/N of 2.8. No clear planetary signal is found from the 1.4 μ\mum band. Conclusions: Our significant signal from the 1.0 μ\mum band in HD 209458 b represents the first detection of H2_2O 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 μ\mum bands. H2_2O is detected from the 1.0 μ\mum 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&

    Association of alpha1a-adrenergic receptor polymorphism and blood pressure phenotypes in the Brazilian population

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    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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