56 research outputs found
A chemical survey of exoplanets with ARIEL
Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio
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
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
Post-intervention Status in Patients With Refractory Myasthenia Gravis Treated With Eculizumab During REGAIN and Its Open-Label Extension
OBJECTIVE: To evaluate whether eculizumab helps patients with anti-acetylcholine receptor-positive (AChR+) refractory generalized myasthenia gravis (gMG) achieve the Myasthenia Gravis Foundation of America (MGFA) post-intervention status of minimal manifestations (MM), we assessed patients' status throughout REGAIN (Safety and Efficacy of Eculizumab in AChR+ Refractory Generalized Myasthenia Gravis) and its open-label extension. METHODS: Patients who completed the REGAIN randomized controlled trial and continued into the open-label extension were included in this tertiary endpoint analysis. Patients were assessed for the MGFA post-intervention status of improved, unchanged, worse, MM, and pharmacologic remission at defined time points during REGAIN and through week 130 of the open-label study. RESULTS: A total of 117 patients completed REGAIN and continued into the open-label study (eculizumab/eculizumab: 56; placebo/eculizumab: 61). At week 26 of REGAIN, more eculizumab-treated patients than placebo-treated patients achieved a status of improved (60.7% vs 41.7%) or MM (25.0% vs 13.3%; common OR: 2.3; 95% CI: 1.1-4.5). After 130 weeks of eculizumab treatment, 88.0% of patients achieved improved status and 57.3% of patients achieved MM status. The safety profile of eculizumab was consistent with its known profile and no new safety signals were detected. CONCLUSION: Eculizumab led to rapid and sustained achievement of MM in patients with AChR+ refractory gMG. These findings support the use of eculizumab in this previously difficult-to-treat patient population. CLINICALTRIALSGOV IDENTIFIER: REGAIN, NCT01997229; REGAIN open-label extension, NCT02301624. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, after 26 weeks of eculizumab treatment, 25.0% of adults with AChR+ refractory gMG achieved MM, compared with 13.3% who received placebo
MicroRNA profiling in serous cavity specimens: Diagnostic challenges and new opportunities
The cytomorphologic evaluation of serous cavity specimens can quickly determine the cause of an effusion as well as the presence or absence of a neoplastic process. Ancillary tests such as immunohistochemistry and fluorescence in situ hybridization are frequently used to help to definitively identify malignant cells, determine a site of origin, and distinguish between malignant and reactive mesothelial proliferations. In recent years, microRNAs (miRNAs) have been increasingly evaluated in cytologic specimens, including those from serous cavities. The examination of miRNA is attractive because of the stability of miRNA in such specimens and data suggesting that miRNA can provide prognostic and therapeutic information in addition to its role in diagnosis. Furthermore, miRNAs exist within extracellular exosomes, and this allows for their analysis in specimens that contain only rare malignant cells, degenerated cells, or obscuring components. This review discusses the technical aspects of specimen processing for miRNA analysis, recent studies of miRNA expression in malignant serous cavity specimens, and the potential importance of miRNA expression analysis for serous cavity specimens in the near future
MicroRNA profiling in serous cavity specimens: Diagnostic challenges and new opportunities
The cytomorphologic evaluation of serous cavity specimens can quickly determine the cause of an effusion as well as the presence or absence of a neoplastic process. Ancillary tests such as immunohistochemistry and fluorescence in situ hybridization are frequently used to help to definitively identify malignant cells, determine a site of origin, and distinguish between malignant and reactive mesothelial proliferations. In recent years, microRNAs (miRNAs) have been increasingly evaluated in cytologic specimens, including those from serous cavities. The examination of miRNA is attractive because of the stability of miRNA in such specimens and data suggesting that miRNA can provide prognostic and therapeutic information in addition to its role in diagnosis. Furthermore, miRNAs exist within extracellular exosomes, and this allows for their analysis in specimens that contain only rare malignant cells, degenerated cells, or obscuring components. This review discusses the technical aspects of specimen processing for miRNA analysis, recent studies of miRNA expression in malignant serous cavity specimens, and the potential importance of miRNA expression analysis for serous cavity specimens in the near future
Recommended from our members
Survival guide to cytopathology by Xiaoyin Sara Jiang, Wen-Chi Foo ; edited by Chris VandenBussche and Elizabeth A. Montgomerey
This survival guide to cytopathology will be a practical, image-rich book giving an organ-based approach to cytodiagnosis. Key cytomorphologic features and helpful ancillary studies will be provided, with photos and helpful tables as well as differential diagnostic considerations for both classic and challenging cases. This volume is designed for learners of cytopathology, those interested in honing their cytopathology skills, and as a quick desk reference for practicing cytopathologists.
Includes bibliographical references and inde
Lymphoproliferative Disorders of the Kidney on Fine-Needle Aspiration: Cytomorphology and Radiographic Correlates in 33 Cases
Background: Unless renal lesions present in the setting of widespread lymphoma, biopsy can be indicated to differentiate from metastases, hypovascular renal cell carcinoma, urothelial carcinoma or infection. We review our experience with lymphoproliferative disorders in the kidney diagnosed by fine-needle aspiration (FNA), and focus on clinicopathologic and radiographic features. Design: All cases of non-Hodgkin lymphoma diagnosed on renal FNA at 2 academic institutions between 1989 and 2011 were reviewed. Clinical history, radiographic and cytomorphologic features, and follow-up were assessed. Results: 33 cases were identified, with 15 primary tumors and 18 recurrences/secondary tumors including 1 acute lymphoblastic lymphoma. The majority were aggressive/high-grade lesions (25/33). 25 cases were substantiated by positive flow cytometry results. Most were detected at follow-up/incidentally. 22 cases showed multiple renal and/or retroperitoneal masses or a significant component of adenopathy; others showed a solitary renal mass. Salient radiologic features included hypodense, infiltrative and ill-defined masses. Cytomorphology showed a monotonous population of large atypical lymphoid cells, often with lymphoglandular bodies. Conclusion: Cytologic diagnosis of renal lymphoma requires analysis of morphological, clinical and immunophenotypic information. Helpful features for diagnosis include: multiple masses on computed tomography, a monotonous population of abnormal cells in a background of lymphoglandular bodies and immunophenotyping demonstrating light chain restriction
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