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We monitor a sample of CEMP-no stars using the CFHT and SALT telescopes to gain additional knowledge about the possible binarity of these stars. This information is valuable for each individual star, and additionally it could be used to further constrain their binary fraction. We find two new CEMP-no binaries and four additional CEMP-no stars that show some indication of radial velocity variations, resulting in a CEMP-no binary fraction of ~20%. [ABSTRACT FROM AUTHOR]

We present the first release of a large-scale study of relatively bright (V < 13.5) metal-poor stars observed with the Southern African Large Telescope (SALT), based on high-resolution spectra of 50 stars with a resolving power of R ∼ 40,000 and S/N ∼ 20 per pixel at 4300 Å. The elemental abundances of C, Sr, Ba, and Eu are reported, as well as several α-elements (Mg, Ca, Sc, Ti, and V) and iron-peak elements (Mn, Co, Ni, and Zn). We find a diverse array of abundance patterns, including several consistent with the signatures of carbon-enhanced metal-poor CEMP-i and CEMP-r stars. We find that 15 of 50 (30%) are carbon enhanced (with [C/Fe] > +0.70), and that a large fraction (26 of 50, 52%) are enhanced in r-process elements. Among the r-process-enhanced stars, five are strongly enhanced r-II ([Eu/Fe] > +1.0) stars (two of which are newly discovered) and 21 are newly discovered moderately enhanced r-I (+0.3 ≤ [Eu/Fe] ≤ +1.0) stars. There are eight stars in our sample that, on the basis of their abundances and kinematics, are possible members of the metal-weak thick-disk population. We also compare our measured abundances to progenitor-enrichment models, and find that the abundance patterns for the majority of our stars can be attributed to a single (rather than multiple) enrichment event. [ABSTRACT FROM AUTHOR]

Carbon-enhanced metal-poor (CEMP) stars comprise a high percentage of stars at the lowest metallicities. The stars in the CEMP-no subcategory do not show any s-process enhancement and therefore cannot easily be explained by transfer of carbon and s-process elements from a binary AGB companion. We have performed radial velocity monitoring of a sample of 22 CEMP-no stars to further study the role that binarity plays in this type of CEMP star. We find four new binary CEMP-no stars based on their radial velocity variations; this significantly enlarges the population of known binaries to a total of 11. One of the new stars found to be in a binary system is HE 0107–5240, which is one of the most iron-poor stars known. This supports the binary transfer model for the origin of the abundance pattern of this star. We find a difference in binary fraction in our sample that depends on the absolute carbon abundance, with a binary fraction of 47 +15−14% 47 − 14 + 15 % $ 47^{+15}_{-14}\% $ for stars with a higher absolute carbon abundance and 18 +14−9% 18 − 9 + 14 % $ 18^{+14}_{-9}\% $ for stars with a lower absolute carbon abundance. This might imply a relation between a high carbon abundance and the binarity of a metal-poor star. Although binarity does not equate to mass transfer, there is a possibility that a CEMP-no star in a binary system has been polluted, and care has to be taken in the interpretation of their abundance patterns. We furthermore demonstrate the potential of Gaia of discovering additional binary candidates. [ABSTRACT FROM AUTHOR]

The DNA-glycosylase OGG1 oversees the detection and clearance of the 7,8-dihydro-8-oxoguanine (8-oxoG), which is the most frequent form of oxidized base in the genome. This lesion is deeply buried within the double-helix and its detection requires careful inspection of the bases by OGG1 via a mechanism that remains only partially understood. By analyzing OGG1 dynamics in the nucleus of living human cells, we demonstrate that the glycosylase constantly samples the DNA by rapidly alternating between diffusion within the nucleoplasm and short transits on the DNA. This sampling process, that we find to be tightly regulated by the conserved residue G245, is crucial for the rapid recruitment of OGG1 at oxidative lesions induced by laser micro-irradiation. Furthermore, we show that residues Y203, N149 and N150, while being all involved in early stages of 8-oxoG probing by OGG1 based on previous structural data, differentially regulate the sampling of the DNA and recruitment to oxidative lesions., (© The Author(s) 2023. Published by Oxford University Press on behalf of Nucleic Acids Research.)

One of the most abundant DNA lesions induced by oxidative stress is the highly mutagenic 8-oxoguanine (8-oxoG), which is specifically recognized by 8-oxoguanine DNA glycosylase 1 (OGG1) to initiate its repair. How DNA glycosylases find small non-helix-distorting DNA lesions amongst millions of bases packaged in the chromatin-based architecture of the genome remains an open question. Here, we used a high-throughput siRNA screening to identify factors involved in the recognition of 8-oxoG by OGG1. We show that cohesin and mediator subunits are required for re-localization of OGG1 and other base excision repair factors to chromatin upon oxidative stress. The association of OGG1 with euchromatin is necessary for the removal of 8-oxoG. Mediator subunits CDK8 and MED12 bind to chromatin and interact with OGG1 in response to oxidative stress, suggesting they participate in the recruitment of the DNA glycosylase. The oxidative stress-induced association between the cohesin and mediator complexes and OGG1 reveals an unsuspected function of those complexes in the maintenance of genomic stability., (© The Author(s) 2020. Published by Oxford University Press on behalf of Nucleic Acids Research.)

A visible astrocomb spanning 555-890 nm has been implemented on the 10-m Southern African Large Telescope, delivering complete calibration of one channel of its high-resolution spectrograph and an accurate determination of its resolving power. A novel co-coupling method allowed simultaneous observation of on-sky, Th-Ar lamp and astrocomb channels, reducing the wavelength calibration uncertainty by a factor of two compared to that obtained using only Th-Ar lines. The excellent passive stability of the master frequency comb laser enabled broadband astrocomb generation without the need for carrier-envelope offset frequency locking, and an atomically referenced narrow linewidth diode laser provided an absolute fiducial marker for wavelength calibration. The simple astrocomb architecture enabled routine operation by non-specialists in an actual telescope environment. On-sky spectroscopy results are presented with direct calibration achieved entirely using the astrocomb.

Objective: Genesis of sleep apnoea syndrome (SAS) in chronic heart failure (CHF) is not well known. The aim of our study was to find associated factors to SAS in heart failure (HF) and to look for differences between central sleep apnea (CSA) and obstructive sleep apnea (OSA)., Patients and Methods: We realised a cross-sectional and retrospective study. Thirty patients with stable heart failure under medical optimal therapy were included. Polygraphy, echocardiography and cardiopulmonary exercise were systematically performed., Results: Men were predominant (80%) in the group. Mean age, left ventricular ejection fraction (LVEF) were respectively 64.1±13.8years and 40±9.8%. SAS was present in 60% of patients (33.3% were classified as central sleep apnoea [CSA] and 26.7% as obstructive sleep apnoea [OSA]). Body mass index, blood pressure and left ventricular pressures estimated by the E/Ea ratio were significantly higher in the group with SAS (P<0.05) compared to the non SAS group. New York Heart Association class was significantly higher (P=0.04) and the predicted peak VO(2) was significantly lower in CSA patients compared to OSA patients., Conclusion: High left ventricular pressures estimated by the E/Ea are significantly associated with SAS in heart failure. CSA patients tend to have a worse functional state than OSA patients., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

Introduction: We report a case of constrictive péricarditis initially revealed by a massive left sided pleural effusion., Case Report: The patient was dyspnoeic without any associated clinical signs. Only cardiac catheterization gave the diagnosis with a characteristic dip-plateau of the right ventricle. After full assessment, no aetiology was found., Conclusion: After a treatment with corticosteroids, the progress has been favourable to date.

Introduction: We report the case of a patient suffering from disseminated actinomycosis., Case Report: A fifty-two year old man, who was both a heavy smoker and an alcoholic, was admitted to hospital with confusion associated with a pseudo-tumoral right upper lobe pneumonia. Brain computed tomography was normal on the day of admission but when repeated fifteen days later four lesions were seen with appearances suspicious of metastatic malignant disease. The isolation of Actinomyces odontolyticus in the bronchoalveolar lavage culture and the absence of evidence for neoplastic disease despite extensive investigation led to a diagnosis of disseminated actinomycosis with pulmonary and cerebral involvement. The patient's clinical condition improved with antibiotic therapy. The disseminated form of this infection as well as presentation with multifocal brain abscesses is rare., Conclusion: The diagnosis of actinomycosis is problematic because it is an uncommon infection and microbiological identification is often difficult and delayed. It should be considered when clinical presentation suggests malignant disease but there is no histological confirmation.

Viral or fungal pneumonia generally occurs in immunocompromised patients. We report a case of hypoxic pneumonia unresponsive to broad-spectrum antibiotic therapy in a patient whose only risk factor for immunodeficiency was mild silent renal failure. The causal association between Herpes simplex and Geotrichum candidum was retained on the basis of endobronchial samples and the favorable course after institution of specific treatment. It is thus useful to consider these pathogens in patients with lung infection in order to institute specific treatment.

We report a case of interstitial pneumonia found by a woman who suffered from a gastroesophageal reflux unamenable to usual treatments. The HR-tomographic discovery of a tone esophagus lead to a manometric study. The association of high autoantibodies levels and radiographic and manometric data were characteristic of esophageal and pulmonary scleroderma.