Tuning the stochastic background of gravitational waves with theory and observations

In this this paper the stochastic background of gravitational waves (SBGWs) is analyzed with the auxilium of the WMAP data. We emphasize that, in general, in previous works in the literature about the SBGWs, old COBE data were used. After this, we want to face the problem of how the SBGWs and f(R) gravity can be related, showing, vice versa, that a revealed SBGWs could be a powerly probe for a given theory of gravity. In this way, it will also be shown that the conformal treatment of SBGWs can be used to parametrize in a natural way f(R) theories.Comment: To appear in "Proceedings of the Fourth Italian-Sino Workshop on Relativistic Astrophysics" July 20-30 2007, Pescara, Ital

Chromatin assembly factor-1 preserves genome stability in ctf4∆ cells by promoting sister chromatid cohesion

Chromatin assembly and the establishment of sister chromatid cohesion are intimately connected to the progression of DNA replication forks. Here we examined the genetic interaction between the heterotrimeric chromatin assembly factor-1 (CAF-1), a central component of chromatin assembly during replication, and the core replisome component Ctf4. We find that CAF-1 deficient cells as well as cells affected in newly-synthesized H3-H4 histones deposition during DNA rep-lication exhibit a severe negative growth with ctf4∆ mutant. We dissected the role of CAF-1 in the maintenance of genome stability in ctf4∆ yeast cells. In the absence of CTF4, CAF-1 is essential for viability in cells experiencing replication problems, in cells lacking functional S-phase checkpoint or functional spindle checkpoint, and in cells lacking DNA repair pathways involving homologous recombination. We present evidence that CAF-1 affects cohesin association to chromatin in a DNA-damage-dependent manner and is essential to maintain cohesion in the absence of CTF4. We also show that Eco1-catalyzed Smc3 acetylation is reduced in absence of CAF-1. Furthermore, we describe genetic interactions between CAF-1 and essential genes involved in cohesin loading, cohesin stabilization, and cohesin component indicating that CAF-1 is crucial for viability when sister chromatid cohesion is affected. Finally, our data indicate that the CAF-1-dependent pathway required for cohesion is functionally distinct from the Rtt101-Mms1-Mms22 pathway which functions in replicated chromatin assembly. Collectively, our results suggest that the deposition by CAF-1 of newly-synthesized H3-H4 histones during DNA replication creates a chromatin environment that favors sister chromatid cohesion and maintains genome integrity

Sleep-disordered breathing and pregnancy outcomes: The impact of maternal oxygen saturation

ObjectiveTo investigate pathological associations between sleep-disordered breathing (SDB) and pregnancy outcomes. MethodsFrom May 2016 to September 2019, obese women during their uncomplicated singleton pregnancies underwent screening sleep questionnaires, oxygen saturation monitoring, and, in proper cases, complete overnight polysomnography. Their medical records were also recorded. ResultsIn all, 112 pregnant women were included in the study cohort; 44 showed an oxygen desaturation index & GE;10, and their newborns had a significantly higher rate of congenital abnormalities and respiratory distress syndrome compared with the women with normal pulse oximetry. Stepwise multivariate regression analysis showed that basal oxygen saturation was independently associated with the occurrence of fetal growth restriction. ConclusionAmong obese pregnant women, the rate of congenital abnormalities is higher in the ones with altered pulse oximetry. Maternal basal oxygen saturation in the first trimester of pregnancy predicts fetal growth restriction independently of maternal age, ethnicity, body mass index, gravidity, and hypertensive disorders of pregnancy

Diagnosis and management of Alpha 1 Antitrypsin deficiency in Europe:an expert survey

Despite recent improvements, α1-antitrypsin deficiency (AATD) remains a rarely diagnosed and treated condition. To assess the variability of AATD diagnosis/treatment in Europe, and to evaluate clinicians’ views on methods to optimise management, specialist AATD clinicians were invited to complete a web-based survey. Surveys were completed by 15 physicians from 14 centres in 13 European countries. All respondents perceived the AATD diagnosis rate to be low in their country; 77% of physicians believed that ∼15% of cases were diagnosed. Low awareness was perceived as the greatest barrier to diagnosis. Spirometry was considered more practical than quantitative computed tomography (QCT) for monitoring AATD patients in clinical practice; QCT was considered more useful in trials. AAT therapy provision was reported to be highly variable: France and Germany were reported to treat the highest proportion (∼60%) of diagnosed patients, in contrast to the UK and Hungary, where virtually no patients receive AAT therapy. Most clinicians supported self-administration and extended dosing intervals to improve convenience of AAT therapy. This survey indicates that AATD diagnosis and management are highly heterogeneous in Europe; European cooperation is essential to generate data to support access to AAT therapy. Improving convenience of AAT therapy is an ongoing objective

Low loss coatings for the VIRGO large mirrors

présentée par L. PinardThe goal of the VIRGO program is to build a giant Michelson type interferometer (3 kilometer long arms) to detect gravitational waves. Large optical components (350 mm in diameter), having extremely low loss at 1064 nm, are needed. Today, the Ion beam Sputtering is the only deposition technique able to produce optical components with such performances. Consequently, a large ion beam sputtering deposition system was built to coat large optics up to 700 mm in diameter. The performances of this coater are described in term of layer uniformity on large scale and optical losses (absorption and scattering characterization). The VIRGO interferometer needs six main mirrors. The first set was ready in June 2002 and its installation is in progress on the VIRGO site (Italy). The optical performances of this first set are discussed. The requirements at 1064 nm are all satisfied. Indeed, the absorption level is close to 1 ppm (part per million), the scattering is lower than 5 ppm and the R.M.S. wavefront of these optics is lower than 8 nm on 150 mm in diameter. Finally, some solutions are proposed to further improve these performances, especially the absorption level (lower than 0.1 ppm) and the mechanical quality factor Q of the mirrors (thermal noise reduction)

The COMPASS subunit Spp1 protects nascent DNA at the Tus/Ter replication fork barrier by limiting DNA availability to nucleases

Abstract Homologous recombination factors play a crucial role in protecting nascent DNA during DNA replication, but the role of chromatin in this process is largely unknown. Here, we used the bacterial Tus/Ter barrier known to induce a site-specific replication fork stalling in S. cerevisiae. We report that the Set1C subunit Spp1 is recruited behind the stalled replication fork independently of its interaction with Set1. Spp1 chromatin recruitment depends on the interaction of its PHD domain with H3K4me3 parental histones deposited behind the stalled fork. Its recruitment prevents the accumulation of ssDNA at the stalled fork by restricting the access of Exo1. We further show that deleting SPP1 increases the mutation rate upstream of the barrier favoring the accumulation of microdeletions. Finally, we report that Spp1 protects nascent DNA at the Tus/Ter stalled replication fork. We propose that Spp1 limits the remodeling of the fork, which ultimately limits nascent DNA availability to nucleases

Daytime approach to Obstructive Sleep Apnea phenotyping

Background: OSA is a common respiratory sleep disorder with multiple pathological traits. Identifying them is pivotal for a phenotype-tailored therapy. The reference phenotyping method is based on measurements obtained by a complex polysomnographic protocol conducted by CPAP manipulation during sleep.Aim: To find out whether it is possible to measure the same phenotypic traits with simpler daytime tests in OSA patients.Methods: 10 OSA patients underwent the reference protocol (gold standard) to identify pathological traits: high upper airway passive collapsibility and loop gain (LG), low arousal threshold (AT) and upper airway gain (UAG). Subsequently, they performed day-time maximum breath holding test and negative expiratory pressure test (NEP), as proxy of LG and upper airway collapsibility, respectively. Basal PSGs were used to assess AT. A new formula combining basal PSG and NEP was created to evaluate UAGd.Results: The volume exhaled in the first 0.5s with NEP at -5 cmH2O (V0.5) was related to pharyngeal collapsibility (r2=0.76, p=0.0009). The second breath after max apnea (V2nd as%Vt) was related to loop gain (r2=0.79,p=0.0005). AT score (1 point each for AHI58.3%, nadirSpO2 >82.5%) was related to ventilation reduction needed to cause an arousal. The daytime upper airway gain formula we developed was related to UAG (r2=0.89,p=0.0001).Conclusions: As each trait was rightly identified, this study proves daytime OSA phenotyping is possible and could have a wider impact on treating patients with best phenotype-tailored therapies.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 2508.This abstract was presented at the 2020 ERS International Congress, in session { extquotedblleft}Respiratory viruses in the "pre COVID-19" era{ extquotedblright}.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only)