37 research outputs found
A study on missing lines in the synthetic solar spectrum near the Ca triplet
Synthetic stellar spectra are extensively used for many different applications in astronomy, from stellar studies (such as in the determination of atmospheric parameters of observed stellar spectra), to extragalactic studies (e.g. as one of the main ingredients of stellar population models). One of the main ingredients of synthetic spectral libraries are the atomic and molecular line lists, which contain the data required to model all the absorption lines that should appear in these spectra. Although currently available line lists contain millions of lines, a relatively small fraction of these lines have accurate derived or measured transition parameters. As a consequence, many of these lines contain errors in the electronic transition parameters that can reach up to 200%. Furthermore, even for the Sun, our closest and most studied star, state-of-the-art synthetic spectra does not reproduce all the observed lines, indicating transitions that are missing in the line lists of the computed synthetic spectra. Given the importance and wide range of applications of these models, improvement of their quality is urgently necessary. In this work we catalogued missing lines in the atomic and molecular line lists used for the calculation of the synthetic spectra in the region of GAIA, comparing a solar model computed via a recent line list with a high quality solar atlas available in the literature. After that, we attempted the calibration of their atomic parameters with the code ALLiCE; the calibrated line parameters are publicly available for use
Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines
The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points
The Science Performance of JWST as Characterized in Commissioning
This paper characterizes the actual science performance of the James Webb
Space Telescope (JWST), as determined from the six month commissioning period.
We summarize the performance of the spacecraft, telescope, science instruments,
and ground system, with an emphasis on differences from pre-launch
expectations. Commissioning has made clear that JWST is fully capable of
achieving the discoveries for which it was built. Moreover, almost across the
board, the science performance of JWST is better than expected; in most cases,
JWST will go deeper faster than expected. The telescope and instrument suite
have demonstrated the sensitivity, stability, image quality, and spectral range
that are necessary to transform our understanding of the cosmos through
observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures;
https://iopscience.iop.org/article/10.1088/1538-3873/acb29
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
A comparison of cytokines and chemokines present in the supernatant of CD3<sup>+</sup> T cells pulsed with IL-2, exosomes or IL-2+exosomes.
<p>Fold changes in the production of cytokines, chemokines and other proteins after five days. T cells stimulated with IL-2 or exosomes had different expression of cytokines and chemokines. Samples stimulated with “exosomes+IL-2″ generated secretion of more cytokines and chemokines compared to samples stimulated with either IL-2 or exosomes alone. A significant decrease could be noticed for CCL5 in cultures stimulated with exosomes only.</p
Human cytokine array (Cytokines).
<p>Fold changes (increase/decrease) in production of <b>cytokines</b> after 5 days in CD3<sup>+</sup> T cells incubated with IL-2, Exosomes, or IL-2+Exosomes.</p
Cytokine production from autologous exosome stimulated CD3<sup>+</sup> T cells at day zero (0 h) and day five (120 h).
<p>Relative quantification of spot intensities was performed using Quantity One software (Bio-Rad). Each bar represents an average of the intensity from two protein spots. White bars represent 0 h and grey bars represent 120 h (day 5). The exosomes appeared to contain significant amounts of CCL5 (RANTES) immediately after the addition of exosomes (at 0 h) since the supernatants showed relatively large amounts of RANTES. These levels were decreased at day five.</p
Cytokine production from exosome+IL-2 stimulated CD3<sup>+</sup> T cells at day zero (0 h) and day five (120 h).
<p>Relative quantification of spot intensities was performed using Quantity One software (Bio-Rad). Each bar represents an average of the intensity from two protein spots. White bars represent 0 h and grey bars represent 120 h (day 5). The cytokines IL-5, IL-13 and GM-CSF as well as the chemokines CCL3 and CCL4 were present at higher levels at day five.</p
Proliferation of CD3<sup>+</sup> T cells pulsed with autologous exosomes.
<p>(A) Number of CD3<sup>+</sup> T cells measured with automatic cell counting (Sysmex) at different time points. Cells stimulated with IL-2+exosomes are increasing in numbers. (B) Proliferation of CD3<sup>+</sup> T cells measured with MTT assay at day five. Cells stimulated with IL-2+exosomes showed increased proliferation. (C) Distribution of CD4<sup>+</sup> and CD8<sup>+</sup> cells in CD3<sup>+</sup> T cells stimulated with IL-2, autologous exosomes or IL-2+exosomes measures with flow cytometry.</p
Cytokine production from IL-2 stimulated CD3<sup>+</sup> T cells at day zero (0 h) and day five (120 h).
<p>Relative quantification of spot intensities was performed using Quantity One software (Bio-Rad). Each bar represents an average of the intensity from two protein spots. White bars represent 0 h and grey bars represent 120 h (day 5). Cytokines IL-5, MIF, and GM-CSF (CSF2) were present at a high level in the supernatant after five days.</p