The CoRoT Evolution and Seismic Tools Activity: Goals and Tasks

The forthcoming data expected from space missions such as CoRoT require the capacity of the available tools to provide accurate models whose numerical precision is well above the expected observational errors. In order to secure that these tools meet the specifications, a team has been established to test and, when necessary, to improve the codes available in the community. The CoRoT evolution and seismic tool activity (ESTA) has been set up with this mission. Several groups have been involved. The present paper describes the motivation and the organisation of this activity, providing the context and the basis for the presentation of the results that have been achieved so far. This is not a finished task as future even better data will continue to demand more precise and complete tools for asteroseismology.Comment: 11 pages, 3 figures, accepted for publication in Astrophysics and Space Science, 'CoRoT ESTA' special volum

Collusion through Joint R&D: An Empirical Assessment

This paper tests whether upstream R&D cooperation leads to downstream collusion. We consider an oligopolistic setting where firms enter in research joint ventures (RJVs) to lower production costs or coordinate on collusion in the product market. We show that a sufficient condition for identifying collusive behavior is a decline in the market share of RJV-participating firms, which is also necessary and sufficient for a decrease in consumer welfare. Using information from the US National Cooperation Research Act, we estimate a market share equation correcting for the endogeneity of RJV participation and R&D expenditures. We find robust evidence that large networks between direct competitors – created through firms being members in several RJVs at the same time – are conducive to collusive outcomes in the product market which reduce consumer welfare. By contrast, RJVs among non-competitors are efficiency enhancing

Complex Effects of Cytochrome P450 Monooxygenase on Purple Membrane and Bacterioruberin Production in an Extremely Halophilic Archaeon: Genetic, Phenotypic, and Transcriptomic Analyses

Halophilic archaea are known to produce a diverse array of pigments for phototrophy and photoprotection. The aim of this paper was to determine the role of a Halobacterium gene encoding the predicted cytochrome P450 monooxygenase (CYP174A1) in pigment synthesis through a combined genetic, phenotypic, and transcriptomic approach. We report on the observed phenotype changes [increased bacterioruberin levels and the loss of purple membrane (PM)] between the Halobacterium salinarum R1 and its CYP174A1-deletion mutant. In addition, we report on the whole-genome DNA microarray analysis, which supports the phenotype of PM loss. This work expands our understanding of the bop-gene regulon, and its relation to carotenoid biosynthesis, and sheds light on our broader understanding of the role (s) of CYP174A1 in archaeal pigment synthesis. To date, this is the first study in which the physiological role of any cytochrome P450 monooxygenase (CYP450) in extremely halophilic archaea has been reported

Whole genome comparison of Thermus sp. NMX2.A1 reveals principal carbon metabolism differences with closest relation Thermus scotoductus SA-01

Genome sequencing of the yellow-pigmented, thermophilic bacterium Thermus sp. NMX2.A1 resulted in a 2.29 Mb draft genome that encodes for 2312 proteins. The genetic relationship between various strains from the genus Thermus was assessed based on phylogenomic analyses using a concatenated set of conserved proteins. The resulting phylogenetic tree illustrated that Thermus sp. NMX2 A.1 clusters together with Thermus scotoductus SA-01, despite being isolated from vastly different geographical locations. The close evolutionary relationship and metabolic parallels between the two strains has previously been recognized; however, neither strain’s genome data were available at that point in time. Genomic comparison of the Thermus sp. NMX2.A1 and T. scotoductus SA-01, as well as other closely related Thermus strains, revealed a high degree of synteny at both the genomic and proteomic level, with processes such as denitrification and natural cell competence appearing to be conserved. However, despite this high level of similarity, analysis revealed a complete, putative Calvin–Benson–Bassham (CBB) cycle in NMX2.A1 that is absent in SA-01. Analysis of horizontally transferred gene islands provide evidence that NMX2 selected these genes due to pressure from its HCO3 - rich environment, which is in stark contrast to that of the deep subsurface isolated SA-01.The National Research Foundation and the Technology Innovation Agency, South Africa.http://www.g3journal.orgam2017Biochemistr

New ecosystems in the deep subsurface follow the flow of water driven by geological activity

Eukarya have been discovered in the deep subsurface at several locations in South Africa, but how organisms reach the subsurface remains unknown. We studied river-subsurface fissure water systems and identified Eukarya from a river that are genetically identical for 18S rDNA. To further confirm that these are identical species one metazoan species recovered from the overlying river interbred successfully with specimen recovered from an underlying mine at −1.4 km. In situ seismic simulation experiments were carried out and show seismic activity to be a major force increasing the hydraulic conductivity in faults allowing organisms to create ecosystems in the deep subsurface. As seismic activity is a non-selective force we recovered specimen of algae and Insecta that defy any obvious other explanation at a depth of −3.4 km. Our results show there is a steady flow of surface organisms to the deep subsurface where some survive and adapt and others perish. As seismic activity is also present on other planets and moons in our solar system the mechanism elucidated here may be relevant for future search and selection of landing sites in planetary exploration.publishedVersio

Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics

A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN

The Cebpd (C/EBPδ) Gene Is Induced by Luteinizing Hormones in Ovarian Theca and Interstitial Cells But Is Not Essential for Mouse Ovary Function

The CCAAT/enhancer binding protein (CEBP) family of transcription factors includes five genes. In the ovary, both Cebpa and Cebpb are essential for granulosa cell function. In this study we have explored the role of the Cebpd gene in ovarian physiology by expression and functional studies. Here we report that Cebpd (C/EBPδ) is expressed in the mouse ovary in a highly restricted temporal and spatial pattern. In response to luteinizing hormone (LH/hCG), CEBPD expression is transiently induced in interstitial cells and in theca cells of follicles from the primary to pre-ovulatory stage, and overlaps in part with expression of the alpha-smooth muscle actin protein. Efficient down-regulation of CEBPD was dependent on a functional Cebpb gene. Proliferating human theca cells in culture also express Cebpd. Cells from patients with polycystic ovarian syndrome (PCOS) exhibited higher Cebpd expression levels. However, deletion of Cebpd in mice had no overt effect on ovarian physiology and reproductive function. Very little is known at present about the molecular mechanisms underlying theca/interstitial cell functions. The expression pattern of CEBPD reported here identifies a novel functional unit of mouse theca cells of primary through tertiary follicles responding to LH/hCG together with a subset of interstitial cells. This acute stimulation of CEBPD expression may be exploited to further characterize the hormonal regulation and function of theca and interstitial cells