Observational Constraints on General Relativistic Energy Conditions, Cosmic Matter Density and Dark Energy from X-Ray Clusters of Galaxies and Type-Ia Supernovae

New observational constraints on the cosmic matter density $\Omega_m$ and an effectively redshift-independent equation of state parameter $w_x$ of the dark energy are obtained while simultaneously testing the strong and null energy conditions of general relativity on macroscopic scales. The combination of REFLEX X-ray cluster and type-Ia supernova data shows that for a flat Universe the strong energy condition might presently be violated whereas the null energy condition seems to be fulfilled. This provides another observational argument for the present accelerated cosmic expansion and the absence of exotic physical phenomena related to a broken null energy condition. The marginalization of the likelihood distributions is performed in a manner to include a large fraction of the recently discussed possible systematic errors involved in the application of X-ray clusters as cosmological probes. This yields for a flat Universe, $\Omega_m=0.29^{+0.08}_{-0.12}$ and $w_x=-0.95^{+0.30}_{-0.35}$ ($1\sigma$ errors without cosmic variance). The scatter in the different analyses indicates a quite robust result around $w_x=-1$, leaving little room for the introduction of new energy components described by quintessence-like models or phantom energy. The most natural interpretation of the data is a positive cosmological constant with $w_x=-1 or something like it.Comment: 11 pages, 5 figures, Astron. Astrophys. (in press

The effects of environment on morphological evolution between 0<z<1.2 in the COSMOS Survey

We explore the evolution of the morphology density relation using the COSMOS-ACS survey and previous cluster studies. The Gini parameter measured in a Petrosian aperture is found to be an effective way of selecting early-type galaxies free from systematic effects with redshift. We find galaxies are transformed from late (spiral and irregular) to early (E+S0) type galaxies more rapidly in dense than sparse regions. At a given density, the early-type fraction grows constantly with cosmic time, but the growth rate increases with density as a power law of index $0.29\pm0.02$. However, at densities below 100 galaxies per Mpc$^{2}$ no evolution is found at $z>0.4$. In contrast the star-formation-density relation shows strong evolution at all densities and redshifts, suggesting different physical mechanisms are responsible for the morphological and star formation transformation. We show photometric redshifts can measure local galaxy environment, but the present results are limited by photometric redshift error to densities above $\Sigma=3$ galaxies per Mpc$^{2}$.Comment: 12 pages, 13 figures, to appear in the COSMOS special issue of the ApJ

Clustering Properties of restframe UV selected galaxies II: Migration of Star Formation sites with cosmic time from GALEX and CFHTLS

We analyze the clustering properties of ultraviolet selected galaxies by using GALEX-SDSS data at z<0.6 and CFHTLS deep u' imaging at z=1. These datasets provide a unique basis at z< 1 which can be directly compared with high redshift samples built with similar selection criteria. We discuss the dependence of the correlation function parameters (r0, delta) on the ultraviolet luminosity as well as the linear bias evolution. We find that the bias parameter shows a gradual decline from high (b > 2) to low redshift (b ~ 0.79^{+0.1}_{-0.08}). When accounting for the fraction of the star formation activity enclosed in the different samples, our results suggest that the bulk of star formation migrated from high mass dark matter halos at z>2 (10^12 < M_min < 10^13 M_sun, located in high density regions), to less massive halos at low redshift (M_min < 10^12 M_sun, located in low density regions). This result extends the ``downsizing'' picture (shift of the star formation activity from high stellar mass systems at high z to low stellar mass at low z) to the dark matter distribution.Comment: Accepted for Publication in the Special GALEX Ap. J. Supplement, December 2007 Version with full resolution fig1 available at http://taltos.pha.jhu.edu/~sebastien/papers/Galex_p2.ps.g

The driver landscape of sporadic chordoma.

Chordoma is a malignant, often incurable bone tumour showing notochordal differentiation. Here, we defined the somatic driver landscape of 104 cases of sporadic chordoma. We reveal somatic duplications of the notochordal transcription factor brachyury (T) in up to 27% of cases. These variants recapitulate the rearrangement architecture of the pathogenic germline duplications of T that underlie familial chordoma. In addition, we find potentially clinically actionable PI3K signalling mutations in 16% of cases. Intriguingly, one of the most frequently altered genes, mutated exclusively by inactivating mutation, was LYST (10%), which may represent a novel cancer gene in chordoma.Chordoma is a rare often incurable malignant bone tumour. Here, the authors investigate driver mutations of sporadic chordoma in 104 cases, revealing duplications in notochordal transcription factor brachyury (T), PI3K signalling mutations, and mutations in LYST, a potential novel cancer gene in chordoma

A c-di-GMP Effector System Controls Cell Adhesion by Inside-Out Signaling and Surface Protein Cleavage

In Pseudomonas fluorescens Pf0-1 the availability of inorganic phosphate (Pi) is an environmental signal that controls biofilm formation through a cyclic dimeric GMP (c-di-GMP) signaling pathway. In low Pi conditions, a c-di-GMP phosphodiesterase (PDE) RapA is expressed, depleting cellular c-di-GMP and causing the loss of a critical outer-membrane adhesin LapA from the cell surface. This response involves an inner membrane protein LapD, which binds c-di-GMP in the cytoplasm and exerts a periplasmic output promoting LapA maintenance on the cell surface. Here we report how LapD differentially controls maintenance and release of LapA: c-di-GMP binding to LapD promotes interaction with and inhibition of the periplasmic protease LapG, which targets the N-terminus of LapA. We identify conserved amino acids in LapA required for cleavage by LapG. Mutating these residues in chromosomal lapA inhibits LapG activity in vivo, leading to retention of the adhesin on the cell surface. Mutations with defined effects on LapD's ability to control LapA localization in vivo show concomitant effects on c-di-GMP-dependent LapG inhibition in vitro. To establish the physiological importance of the LapD-LapG effector system, we track cell attachment and LapA protein localization during Pi starvation. Under this condition, the LapA adhesin is released from the surface of cells and biofilms detach from the substratum. This response requires c-di-GMP depletion by RapA, signaling through LapD, and proteolytic cleavage of LapA by LapG. These data, in combination with the companion study by Navarro et al. presenting a structural analysis of LapD's signaling mechanism, give a detailed description of a complete c-di-GMP control circuit—from environmental signal to molecular output. They describe a novel paradigm in bacterial signal transduction: regulation of a periplasmic enzyme by an inner membrane signaling protein that binds a cytoplasmic second messenger

Recurrent intragenic rearrangements of EGFR and BRAF in soft tissue tumors of infants.

Soft tissue tumors of infancy encompass an overlapping spectrum of diseases that pose unique diagnostic and clinical challenges. We studied genomes and transcriptomes of cryptogenic congenital mesoblastic nephroma (CMN), and extended our findings to five anatomically or histologically related soft tissue tumors: infantile fibrosarcoma (IFS), nephroblastomatosis, Wilms tumor, malignant rhabdoid tumor, and clear cell sarcoma of the kidney. A key finding is recurrent mutation of EGFR in CMN by internal tandem duplication of the kinase domain, thus delineating CMN from other childhood renal tumors. Furthermore, we identify BRAF intragenic rearrangements in CMN and IFS. Collectively these findings reveal novel diagnostic markers and therapeutic strategies and highlight a prominent role of isolated intragenic rearrangements as drivers of infant tumors

The Impact of Teams on Output, Quality, and Downtime: An Empirical Analysis Using Individual Panel Data

The authors use the econometric case study method to investigate the direct impact of offline teams on productivity in a non-unionized subsidiary of a multinational firm from January 1999 through November 2001. They analyze daily data on rejection, production, and downtime rates for both team and non-team-member operators. They hypothesize that team membership without complementary involvement practices is initially sufficient to enhance productivity and quality control. Further, the use of teams leads initially to more downtime, but this cost will diminish over time. Findings indicate that membership in offline teams initially increases individual productivity by about 3% and lowers rejection rates by about 27%. These improvements dissipate, however, typically at a rate of 10 to 16% per 100 days in a team. For these benefits to be sustained, team membership must be complemented with measures that provide extrinsic rewards. The authors also find that the performance-enhancing effects of team membership are generally greater and longer-lasting for more educated members. JEL classification: F23, J24, L60, M11, M12, M5

The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

Structural Basis for c-di-GMP-Mediated Inside-Out Signaling Controlling Periplasmic Proteolysis

X-ray crystallographic structural analyses of the bacterial transmembrane receptor LapD identify conserved molecular mechanisms that control biofilm formation in response to changes in the intracellular levels of the second messenger c-di-GMP