Le Forum, Vol. 42 No. 4

https://digitalcommons.library.umaine.edu/francoamericain_forum/1097/thumbnail.jp

Identification of carbon dioxide in an exoplanet atmosphere

Carbon dioxide (CO2) is a key chemical species that is found in a wide range of planetary atmospheres. In the context of exoplanets, CO2 is an indicator of the metal enrichment (that is, elements heavier than helium, also called ‘metallicity’), and thus the formation processes of the primary atmospheres of hot gas giants. It is also one of the most promising species to detect in the secondary atmospheres of terrestrial exoplanets. Previous photometric measurements of transiting planets with the Spitzer Space Telescope have given hints of the presence of CO2, but have not yielded definitive detections owing to the lack of unambiguous spectroscopic identification. Here we present the detection of CO2 in the atmosphere of the gas giant exoplanet WASP-39b from transmission spectroscopy observations obtained with JWST as part of the Early Release Science programme. The data used in this study span 3.0–5.5 micrometres in wavelength and show a prominent CO2 absorption feature at 4.3 micrometres (26-sigma significance). The overall spectrum is well matched by one-dimensional, ten-times solar metallicity models that assume radiative–convective–thermochemical equilibrium and have moderate cloud opacity. These models predict that the atmosphere should have water, carbon monoxide and hydrogen sulfide in addition to CO2, but little methane. Furthermore, we also tentatively detect a small absorption feature near 4.0 micrometres that is not reproduced by these models

Compound Aggregation in Drug Discovery: Implementing a Practical NMR Assay for Medicinal Chemists

The pharmaceutical industry has recognized that many drug-like molecules can self-aggregate in aqueous media and have physicochemical properties that skew experimental results and decisions. Herein, we introduce the use of a simple NMR strategy for detecting the formation of aggregates using dilution experiments that can be performed on equipment prevalent in most synthetic chemistry departments. We show that ¹H NMR resonances are sensitive to large molecular-size entities and to smaller multimers and mixtures of species. Practical details are provided for sample preparation and for determining the concentrations of single molecule, aggregate entities, and precipitate. The critical concentrations above which aggregation begins can be found and were corroborated by comparisons with light scattering techniques. Disaggregation can also be monitored using detergents. This NMR assay should serve as a practical and readily available tool for medicinal chemists to better characterize how their compounds behave in aqueous media and influence drug design decisions

RPAP1, a Novel Human RNA Polymerase II-Associated Protein Affinity Purified with Recombinant Wild-Type and Mutated Polymerase Subunits

We have programmed human cells to express physiological levels of recombinant RNA polymerase II (RNAPII) subunits carrying tandem affinity purification (TAP) tags. Double-affinity chromatography allowed for the simple and efficient isolation of a complex containing all 12 RNAPII subunits, the general transcription factors TFIIB and TFIIF, the RNAPII phosphatase Fcp1, and a novel 153-kDa polypeptide of unknown function that we named RNAPII-associated protein 1 (RPAP1). The TAP-tagged RNAPII complex is functionally active both in vitro and in vivo. A role for RPAP1 in RNAPII transcription was established by shutting off the synthesis of Ydr527wp, a Saccharomyces cerevisiae protein homologous to RPAP1, and demonstrating that changes in global gene expression were similar to those caused by the loss of the yeast RNAPII subunit Rpb11. We also used TAP-tagged Rpb2 with mutations in fork loop 1 and switch 3, two structural elements located strategically within the active center, to start addressing the roles of these elements in the interaction of the enzyme with the template DNA during the transcription reaction

Reducing readmission rates for individuals discharged from acute psychiatric care in Alberta using peer and text message support: Protocol for an innovative supportive program

Abstract Background Individuals discharged from inpatient psychiatry units have the highest readmission rates of all hospitalized patients. These readmissions are often due to unmet need for mental health care compounded by limited human resources. Reducing the need for hospital admissions by providing alternative effective care will mitigate the strain on the healthcare system and for people with mental illnesses and their relatives. We propose implementation and evaluation of an innovative program which augments Mental Health Peer Support with an evidence-based supportive text messaging program developed using the principles of cognitive behavioral therapy. Methods A pragmatic stepped-wedge cluster-randomized trial, where daily supportive text messages (Text4Support) and mental health peer support are the interventions, will be employed. We anticipate recruiting 10,000 participants at the point of their discharge from 9 acute care psychiatry sites and day hospitals across four cities in Alberta. The primary outcome measure will be the number of psychiatric readmissions within 30 days of discharge. We will also evaluate implementation outcomes such as reach, acceptability, fidelity, and sustainability. Our study will be guided by the Consolidated Framework for Implementation Research, and the Reach-Effectiveness-Adoption-Implementation-Maintenance framework. Data will be extracted from administrative data, surveys, and qualitative methods. Quantitative data will be analysed using machine learning. Qualitative interviews will be transcribed and analyzed thematically using both inductive and deductive approaches. Conclusions To our knowledge, this will be the first large-scale clinical trial to assess the impact of a daily supportive text message program with and without mental health peer support for individuals discharged from acute psychiatric care. We anticipate that the interventions will generate significant cost-savings by reducing readmissions, while improving access to quality community mental healthcare and reducing demand for acute care. It is envisaged that the results will shed light on the effectiveness, as well as contextual barriers and facilitators to implementation of automated supportive text message and mental health peer support interventions to reduce the psychological treatment and support gap for patients who have been discharged from acute psychiatric care. Trial registration clinicaltrials.gov, NCT05133726 . Registered 24 November 202