CMB-S4: Forecasting Constraints on Primordial Gravitational Waves

CMB-S4---the next-generation ground-based cosmic microwave background (CMB) experiment---is set to significantly advance the sensitivity of CMB measurements and enhance our understanding of the origin and evolution of the Universe, from the highest energies at the dawn of time through the growth of structure to the present day. Among the science cases pursued with CMB-S4, the quest for detecting primordial gravitational waves is a central driver of the experimental design. This work details the development of a forecasting framework that includes a power-spectrum-based semi-analytic projection tool, targeted explicitly towards optimizing constraints on the tensor-to-scalar ratio, $r$, in the presence of Galactic foregrounds and gravitational lensing of the CMB. This framework is unique in its direct use of information from the achieved performance of current Stage 2--3 CMB experiments to robustly forecast the science reach of upcoming CMB-polarization endeavors. The methodology allows for rapid iteration over experimental configurations and offers a flexible way to optimize the design of future experiments given a desired scientific goal. To form a closed-loop process, we couple this semi-analytic tool with map-based validation studies, which allow for the injection of additional complexity and verification of our forecasts with several independent analysis methods. We document multiple rounds of forecasts for CMB-S4 using this process and the resulting establishment of the current reference design of the primordial gravitational-wave component of the Stage-4 experiment, optimized to achieve our science goals of detecting primordial gravitational waves for $r > 0.003$ at greater than $5\sigma$, or, in the absence of a detection, of reaching an upper limit of $r < 0.001$ at $95\%$ CL.Comment: 24 pages, 8 figures, 9 tables, submitted to ApJ. arXiv admin note: text overlap with arXiv:1907.0447

CMB-S4

We describe the stage 4 cosmic microwave background ground-based experiment CMB-S4

CMB-S4: Forecasting Constraints on Primordial Gravitational Waves

Abstract: CMB-S4—the next-generation ground-based cosmic microwave background (CMB) experiment—is set to significantly advance the sensitivity of CMB measurements and enhance our understanding of the origin and evolution of the universe. Among the science cases pursued with CMB-S4, the quest for detecting primordial gravitational waves is a central driver of the experimental design. This work details the development of a forecasting framework that includes a power-spectrum-based semianalytic projection tool, targeted explicitly toward optimizing constraints on the tensor-to-scalar ratio, r, in the presence of Galactic foregrounds and gravitational lensing of the CMB. This framework is unique in its direct use of information from the achieved performance of current Stage 2–3 CMB experiments to robustly forecast the science reach of upcoming CMB-polarization endeavors. The methodology allows for rapid iteration over experimental configurations and offers a flexible way to optimize the design of future experiments, given a desired scientific goal. To form a closed-loop process, we couple this semianalytic tool with map-based validation studies, which allow for the injection of additional complexity and verification of our forecasts with several independent analysis methods. We document multiple rounds of forecasts for CMB-S4 using this process and the resulting establishment of the current reference design of the primordial gravitational-wave component of the Stage-4 experiment, optimized to achieve our science goals of detecting primordial gravitational waves for r > 0.003 at greater than 5σ, or in the absence of a detection, of reaching an upper limit of r < 0.001 at 95% CL

Ingestion spontanée d'argiles chez le rat : rôle dans la physiologie intestinale

Cette thèse s'inscrit dans une perspective à moyen terme de pouvoir étudier les mécanismes de l'interaction des minéraux argileux avec un organisme vivant dans le cadre d'une approche pluridisciplinaire, à la fois minéralogique, chimique et biologique. Elle repose au départ sur la notion de géophagie, ou ingestion volontaire de terre, un comportement naturel fréquemment observé chez de nombreux animaux et chez l'Homme. La consommation par de nombreux vertébrés d'éléments provenant du sol et notamment d'argiles semble être dans ce cas totalement instinctive. Elle est également observée de manière récurrente en situation de pénurie alimentaire. En médecine humaine, et ceci depuis des millénaires, l'ingestion d'argile permet de traiter des pathologies digestives diverses. A partir d'expériences menées sur des rats de laboratoire, l'objectif du travail était d'étudier l'effet de l'ingestion d'argile sur la muqueuse intestinale et sur le métabolisme nutritionnel. Un protocole a été mis au point pour comparer des rats témoins et des rats soumis à différents régimes nutritionnels complémentés en argile (kaolinite ou montmorillonite). En combinant les approches à différentes échelles d'observation, et en confrontant les données obtenues au niveau de l'organisme entier et au niveau de la muqueuse intestinale (MP, MET, MEB), il a été montré que la complémentation en argile avait des effets contrastés en fonction de la durée (7 à 28 jours) et/ou du régime alimentaire (alimentation standard, jeûne prolongé, réalimentation, restriction). Un profil de réaction/différentiation cellulaire de la muqueuse intestinale a pu être proposé. En perspective, la confrontation avec des données physiologiques et protéomiques convergentes obtenues par ailleurs appelle à des études complémentaires (autres argiles, autres durées, autres modes d'administration) pour confirmer le schéma proposé, mieux évaluer les effets-dose, mieux comprendre les relations entre les effets potentiellement bénéfiques ou toxiques.The perspective of this thesis is at medium-term to study the mechanisms by which clay minerals interact with a living organism on the basis of a multidisciplinary mineralogical, chemical and biological approach. The work is initiated by the description of geophagia, a natural behavior frquently observed in many animals and humans, and consisting in voluntary ingestion of soil. Consumption of elements from the soil, including clays, by many vertebrates appears to be in this case totally instinctive. Such a practice has also been observed repeatedly in situations of food restriction. Furthermore, clay ingestion in human medicine, and this for millennia, is used to treat various digestive disorders. Thus, the aim of the work was to study on rats and in laboratory conditions the effect of clay ingestion on the intestinal mucosa and on nutritional metabolism. A protocol was developed to compare normally fed rats and rats fed with different diets complemented with clay (kaolinite or montmorillonite). By combining the approaches at different scales of observation, and by comparing the data obtained at the whole body level and for the intestinal mucosa (PM, TEM, SEM), it was shown that clay complementation had contrasting effects depending on the duration (7 to 28 days) and / or type (standard diet, prolonged fasting, realimentation, restrictions) of diet. A cellular profile of reaction / differentiation of the intestinal mucosa has been proposed. In perspective, the comparison with converging physiological and proteomic data obtained in a parallel study, calls for further studies (other clays, other diet durations, other feeding conditions) to confirm the proposed hypothesis, to better assess the dose-effect relationship, and to better understand the potential relationship between beneficial and toxic effects

Ingestion spontanée d'argiles chez le rat : rôle dans la physiologie intestinale

Cette thèse s'inscrit dans une perspective à moyen terme de pouvoir étudier les mécanismes de l'interaction des minéraux argileux avec un organisme vivant dans le cadre d'une approche pluridisciplinaire, à la fois minéralogique, chimique et biologique. ElThe perspective of this thesis is at medium-term to study the mechanisms by which clay minerals interact with a living organism on the basis of a multidisciplinary mineralogical, chemical and biological approach. The work is initiated by the description

Les formes de sociabilité en France du milieu du XVIIIe au milieu du XIXe siècle

François Étienne, Reichardt Rolf. Les formes de sociabilité en France du milieu du XVIIIe au milieu du XIXe siècle. In: Revue d’histoire moderne et contemporaine, tome 34 N°3, Juillet-septembre 1987. pp. 453-472

Morphological changes of the rat intestinal lining in relation to body stores depletion during fasting and after refeeding.

International audienceIntestinal villus atrophy through prolonged fasting was studied according to two different metabolic phases reached by fasting animals and characterized by (a) the mobilization of fat stores as body fuel and (b) an increase in protein catabolism for energy expenditure. The mechanisms involved in the rapid jejunal restoration after refeeding were also determined. Mucosal structural atrophy during fasting proved to worsen over the two phases due mainly to the retraction of the lacteals in the lamina propria, as observed through the immunolocalization of aquaporin 1 in the endothelial cells of the lymphatic vessels and the detachment of the basal membrane of the epithelial lining at the tip of the villi. Microvilli surface area is preserved through fasting, and apical PepT1 expression increases during both metabolic fasting phases. Refeeding after both fasting phases induces an increase in FATP4 accompanied by a rapid lipid uptake by the enterocytes at the tip of the villi and a rapid extension of the lamina propria due to inflated lymphatic vessels. These mechanisms were more prevalent in animals refed after the phase III fast and could be considered as the major processes allowing complete morphological restoration of the jejunum within only 3 days after refeeding

The tumor suppressor Brat controls neuronal stem cell lineages by inhibiting Deadpan and Zelda

The TRIM-NHL protein Brain tumor (Brat) acts as a tumor suppressor in the Drosophila brain, but how it suppresses tumor formation is not completely understood. Here, we combine temperaturecontrolled brat RNAi with transcriptome analysis to identify the immediate Brat targets in Drosophila neuroblasts. Besides the known target Deadpan (Dpn), our experiments identify the transcription factor Zelda (Zld) as a critical target of Brat. Our data show that Zld is expressed in neuroblasts and required to allow re-expression of Dpn in transit-amplifying intermediate neural progenitors. Upon neuroblast division, Brat is enriched in one daughter cell where its NHL domain directly binds to specific motifs in the 3'UTR of dpn and zld mRNA to mediate their degradation. In brat mutants, both Dpn and Zld continue to be expressed, but inhibition of either transcription factor prevents tumorigenesis. Our genetic and biochemical data indicate that Dpn inhibition requires higher Brat levels than Zld inhibition and suggest a model where stepwise post-transcriptional inhibition of distinct factors ensures sequential generation of fates in a stem cell lineage

A Familybased Study Does Not Support the Association of a Functional Polymorphism in the Gene for Endothelial Nitric Oxide Synthase with Risk for Rheumatoid Arthritis

International audienc