Abstract
We present the Mid-infrared stellar Diameters and Fluxes compilation Catalogue (MDFC) dedicated to long-baseline interferometry at mid-infrared wavelengths (3–13 $\mu$m). It gathers data for ...half a million stars, i.e. nearly all the stars of the Hipparcos-Tycho catalogue whose spectral type is reported in the SIMBAD data base. We cross-match 26 data bases to provide basic information, binarity elements, angular diameter, magnitude and flux in the near and mid-infrared, as well as flags that allow us to identify the potential calibrators. The catalogue covers the entire sky with 465 857 stars, mainly dwarfs and giants from B to M spectral types closer than 18 kpc. The smallest reported values reach 0.16 $\mu$Jy in L and 0.1 $\mu$Jy in N for the flux, and 2 microarcsec for the angular diameter. We build four lists of calibrator candidates for the L and Nbands suitable with the Very Large Telescope Interferometer (VLTI) sub- and main arrays using the MATISSE instrument. We identify 1621 candidates for L and 44 candidates for N with the Auxiliary Telescopes (ATs), 375 candidates for both bands with the ATs, and 259 candidates for both bands with the Unit Telescopes (UTs). Predominantly cool giants, these sources are small and bright enough to belong to the primary lists of calibrator candidates. In the near future, we plan to measure their angular diameter with 1 per cent accuracy.
ABSTRACT
A good knowledge of the angular diameters of stars used to calibrate the observables in stellar interferometry is fundamental. As the available precision for giant stars is worse than the ...required per cent level, we aim to improve the knowledge of many diameters using MATISSE (Multiple AperTure mid-Infrared SpectroScopic Experiment) data in its different instrumental configurations. Using the squared visibility MATISSE observable, we compute the angular diameter value, which ensures the best-fitting curves, assuming an intensity distribution of a uniform disc. We take into account that the transfer function varies over the wavelength and is different from one instrumental configuration to another. The uncertainties on the diameters are estimated using the residual bootstrap method. Using the low spectral resolution mode in the Lband, we observed a set of 35 potential calibrators selected in the Mid-infrared stellar Diameter and Flux Compilation Catalogue with diameters ranging from about 1 to 3 mas. We reach a precision on the diameter estimates in the range 0.6 per cent to 4.1 per cent. The study of the stability of the transfer function in visibility over two nights makes us confident in our results. In addition, we identify one star, 75 Vir initially present in the calibrator lists, for which our method does not converge, and prove to be a binary star. This leads us to the conclusion that our method is actually necessary to improve the quality of the astrophysical results obtained with MATISSE, and that it can be used as a useful tool for ‘bad calibrator’ detection.
The use of inexpensive biological materials, such as marine algae for removing dyes from contaminated industrial effluents appears as a potential alternative method. The aim of this study is to ...investigate the aptitude of marine macroalgae Posidonia Oceanica local biomass abundant on the coasts of Algeria for selective sorption of methylene blue (MB) from an aqueous solution in batch experiments at 20 °C. A maximum percentage removal of Posidonia oceanica occurs at pH 5. Equilibrium isotherm data were analyzed using the Langmuir and the Freundlich isotherms. The adsorption equilibrium of methylene blue was best describe by Langmuir model than the Freundlich model. The maximum sorption capacity was 357 mgg−1at pH 5. The sorption data were very well described by the pseudo-second-order model. Keywords: Posidonia oceanica, Methylene blue (MB), Biosorption, Isotherm Equilibrium, Kinetics; Modelling.
Equitable practices in school mental health DeBoer, Jacob L.; Allouche, Sam F.; Vasquez, Jennifer I. ...
Psychology in the schools,
June 2022, Volume:
59, Issue:
6
Journal Article
Peer reviewed
Given the prevalence and negative outcomes associated with untreated mental health concerns, there is an urgent need for schools to enhance their capacity to prevent, identify, and address these ...needs. This is particularly important for students from culturally and linguistically diverse backgrounds, who are more likely to be underserved and face barriers to mental health treatment. Current methods of addressing mental health at school are reactive and insufficient, failing to address the needs of all students. Without an explicit focus on dismantling systemic racism and inequity within schools, our society will continue to underserve those already disenfranchised. As such, this paper outlines the challenges as well as the importance of incorporating culture into a conceptualization of universal mental health in schools. We include state‐, district‐, and school‐level solutions in this conceptualization. Specifically, we propose sample solutions to the implementation of equity‐focused, comprehensive mental health practices within a multitiered system of support, focusing predominantly on universal (i.e., tier 1 level) practices.
HIGHLIGHTS
1.
Schools must enhance their capacity to prevent, identify, and address mental health concerns for all students. This cannot be effectively addressed without an explicit focus on dismantling systemic racism and inequity within the school system.
2.
This paper provides several specific recommendations for the implementation of culturally responsive school mental health practices. These recommendations were organized into three overarching themes: cultivating cultural humility, developing a culturally responsive school climate, and conducting culturally responsive assessment.
3.
These recommendations are not intended to be exhaustive; rather, the recommendations are intended to be critiqued, amended, and expanded upon by future researchers and stakeholders invested in the implementation of equitable school mental health services.
Mental health challenges (including mood, anxiety, and behavioral disorders) affect up to one-fifth of adolescents ages 13–18. Although these disorders are associated with impairments in ...psychological, academic, social, and family domains, they are often left untreated. Schools have great potential to address this service-underutilization gap by identifying those students at risk through mental health screening tools and by providing treatment at no cost for students. However, at the secondary level, school personnel partly expect high school students to initiate support for themselves. The present study advances research by exploring the variables related to adolescent mental health help-seeking intentions within the school setting. Specifically, this study assesses the utility of the theory of planned behavior in an effort to identify what factors relate to high school students' willingness to seek help at school. A secondary aim of this study was to examine why adolescent boys are consistently less willing to seek help for mental health problems than adolescent girls. Results of this study highlight important factors to target when developing interventions to increase help-seeking intent in high school students.
Context.
Optical interferometry is at a key development stage. The Very Large Telescope Interferometer (VLTI) has established a stable, robust infrastructure for long-baseline interferometry that is ...usable by general astronomical observers. The present second-generation instruments offer a wide wavelength coverage and improved performance. Their sensitivity and measurement accuracy lead to data and images of high reliability.
Aims.
We have developed the Multi AperTure mid-Infrared SpectroScopic Experiment (MATISSE) to access, for the first time, high resolution imaging in a wide spectral domain. Many front-line topics are explored with this new equipment, including: stellar activity and mass loss; planet formation and evolution in the gas and dust disks around young stars; and environment interaction and accretion processes around super massive black holes in active galactic nuclei.
Methods.
The instrument is a spectro-interferometric imager in the transmission windows called
L
,
M
, and
N
, from 2.8 to 13.0 microns, combining four optical beams from the VLTI’s unit or auxiliary telescopes. Its concept, related observing procedure, data reduction, and calibration approach, is the product of 30 years of instrumental research and has benefitted from the expertise developed in the frame of the VLTI’s first generation instruments. The instrument utilises a multi-axial beam combination that delivers spectrally dispersed fringes. The signal provides the following quantities at several spectral resolutions: photometric flux, coherent fluxes, visibilities, closure phases, wavelength differential visibilities and phases, and aperture-synthesis imaging.
Results.
This article provides an overview of the physical principle of the instrument and its functionalities. The motivation of the choice of the instrumental concept and the characteristics of the delivered signal are detailed with a description of the observing modes and of their performance limit. MATISSE offers four spectral resolutions in
L
&
M
bands, namely 30, 500, 1000 and 3400, and 30 and 220 in the
N
band, and it provides an angular resolution down to 3 mas for the shortest wavelengths. The MATISSE stand-alone sensitivity limits are 60 mJy in
L
and 300 mJy in
N
. The paper gives details of the sensitivity limits for the different measurables and their related precision criteria, considering telescope configurations and spectral resolutions. We also discuss the gain provided with the GRA4MAT fringe tracker. An ensemble of data and reconstructed images illustrate the first acquired key observations.
Conclusions.
The instrument has been in operation at Cerro Paranal, ESO, Chile, since 2018, and has been open for science use by the international community since April 2019. The first scientific results are being published now.
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