Flying phase mask for the printing of long submicron-period stitchingless gratings

International audienceLong and stitchingless gratings are printed by means of a read/write head comprising a phase mask illuminated by an intensity modulated laser beam and a reference grating displacement sensor which dictates the modulation period real time. A nearly perfect grating copying is achieved by fixing the sensor grating scale and the written grating substrate on a long platform sliding under the read/write hea

K pi scattering for isospin 1/2 and 3/2 in lattice QCD

We simulate K pi scattering in s-wave and p-wave for both isospins I=1/2, 3/2 using quark-antiquark and meson-meson interpolating fields. We extract the elastic phase shifts delta at several values of the K-pi relative momenta. The resulting phases exhibit qualitative agreement with the experimental phases in all four channels. We express the s-wave phase shifts near threshold in terms of the scattering length and the effective range. Our K pi system has zero total momentum and is simulated on a single ensemble with two dynamical quarks, so results apply for mpi=266 MeV and mK=552 MeV in our simulation. The backtracking contractions in both I=1/2 channels are handled by the use of Laplacian-Heavyside smeared quarks within the distillation method. Elastic phases are extracted from the energy levels using Luscher's relations. In all four channels we observe the expected K(n)pi(-n) scattering states, which are shifted due to the interaction. In both attractive I=1/2 channels we observe additional states that are related to resonances; we attribute them to K_0^*(1430) in s-wave and K*(892), K*(1410) and K*(1680) in p-wave.Comment: 17 pages, 7 figures, version published in PR

Pattern and process in Amazon tree turnover, 1976-2001

Previous work has shown that tree turnover, tree biomass and large liana densities have increased in mature tropical forest plots in the late twentieth century. These results point to a concerted shift in forest ecological processes that may already be having significant impacts on terrestrial carbon stocks, fluxes and biodiversity. However, the findings have proved controversial, partly because a rather limited number of permanent plots have been monitored for rather short periods. The aim of this paper is to characterize regional-scale patterns of 'tree turnover' (the rate with which trees die and recruit into a population) by using improved datasets now available for Amazonia that span the past 25 years. Specifically, we assess whether concerted changes in turnover are occurring, and if so whether they are general throughout the Amazon or restricted to one region or environmental zone. In addition, we ask whether they are driven by changes in recruitment, mortality or both. We find that: (i) trees 10 cm or more in diameter recruit and die twice as fast on the richer soils of southern and western Amazonia than on the poorer soils of eastern and central Amazonia; (ii) turnover rates have increased throughout Amazonia over the past two decades; (iii) mortality and recruitment rates have both increased significantly in every region and environmental zone, with the exception of mortality in eastern Amazonia; (iv) recruitment rates have consistently exceeded mortality rates; (v) absolute increases in recruitment and mortality rates are greatest in western Amazonian sites; and (vi) mortality appears to be lagging recruitment at regional scales. These spatial patterns and temporal trends are not caused by obvious artefacts in the data or the analyses. The trends cannot be directly driven by a mortality driver (such as increased drought or fragmentation-related death) because the biomass in these forests has simultaneously increased. Our findings therefore indicate that long-acting and widespread environmental changes are stimulating the growth and productivity of Amazon forests

Design and construction of a Cherenkov imager for charge measurement of nuclear cosmic rays

A proximity focusing Cherenkov imager called CHERCAM, has been built for the charge measurement of nuclear cosmic rays with the CREAM instrument. It consists of a silica aerogel radiator plane across from a detector plane equipped with 1,600 1" diameter photomultipliers. The two planes are separated by a ring expansion gap. The Cherenkov light yield is proportional to the charge squared of the incident particle. The expected relative light collection accuracy is in the few percents range. It leads to an expected single element separation over the range of nuclear charge Z of main interest 1 < Z < 26. CHERCAM is designed to fly with the CREAM balloon experiment. The design of the instrument and the implemented technical solutions allowing its safe operation in high altitude conditions (radiations, low pressure, cold) are presented.Comment: 24 pages, 19 figure

Inheritance of an Epigenetic Mark: The CpG DNA Methyltransferase 1 Is Required for De Novo Establishment of a Complex Pattern of Non-CpG Methylation

Site-specific methylation of cytosines is a key epigenetic mark of vertebrate DNA. While a majority of the methylated residues are in the symmetrical (meC)pG:Gp(meC) configuration, a smaller, but significant fraction is found in the CpA, CpT and CpC asymmetric (non-CpG) dinucleotides. CpG methylation is reproducibly maintained by the activity of the DNA methyltransferase 1 (Dnmt1) on the newly replicated hemimethylated substrates (meC)pG:GpC. On the other hand, establishment and hereditary maintenance of non-CpG methylation patterns have not been analyzed in detail. We previously reported the occurrence of site- and allele-specific methylation at both CpG and non-CpG sites. Here we characterize a hereditary complex of non-CpG methylation, with the transgenerational maintenance of three distinct profiles in a constant ratio, associated with extensive CpG methylation. These observations raised the question of the signal leading to the maintenance of the pattern of asymmetric methylation. The complete non-CpG pattern was reinstated at each generation in spite of the fact that the majority of the sperm genomes contained either none or only one methylated non-CpG site. This observation led us to the hypothesis that the stable CpG patterns might act as blueprints for the maintenance of non-CpG DNA methylation. As predicted, non-CpG DNA methylation profiles were abrogated in a mutant lacking Dnmt1, the enzymes responsible for CpG methylation, but not in mutants defective for either Dnmt3a or Dnmt2

Recurrence of Dupuytren’s contracture: A consensus-based definition

Purpose: One of the major determinants of Dupyutren disease (DD) treatment efficacy is recurrence of the contracture. Unfortunately, lack of agreement in the literature on what constitutes recurrence makes it nearly impossible to compare the multiple treatments alternatives available today. The aim of this study is to bring an unbiased pool of experts to agree upon what would be considered a recurrence of DD after treatment; and from that consensus establish a much-needed definition for DD recurrence. Methods: To reach an expert consensus on the definition of recurrence we used the Delphi method and invited 43 Dupuytren’s research and treatment experts from 10 countries to participate by answering a series of questionnaire rounds. After each round the answers were analyzed and the experts received a feedback report with another questionnaire round to further hone in of the definition. We defined consensus when at least 70% of the experts agreed on a topic. Results: Twenty-one experts agreed to participate in this study. After four consensus rounds, we agreed that DD recurrence should be defined as “more than 20 degrees of contracture recurrence in any treated joint at one year post-treatment compared to six weeks post-treatment”. In addition, “recurrence should be reported individually for every treated joint” and afterwards measurements should be repeated and reported yearly. Conclusion: This study provides the most comprehensive to date definition of what should be considered recurrence of DD. These standardized criteria should allow us to better evaluate the many treatment alternatives

Performance status is the most powerful risk factor for early death among patients with advanced soft tissue sarcoma The European Organisation for Research and Treatment of Cancer – Soft Tissue and Bone Sarcoma Group (STBSG) and French Sarcoma Group (FSG) study

BACKGROUND: We investigated prognostic factors (PFs) for 90-day mortality in a large cohort of advanced/metastatic soft tissue sarcoma (STS) patients treated with first-line chemotherapy. METHODS: The PFs were identified by both logistic regression analysis and probability tree analysis in patients captured in the Soft Tissue and Bone Sarcoma Group (STBSG) database (3002 patients). Scores derived from the logistic regression analysis and algorithms derived from probability tree analysis were subsequently validated in an independent study cohort from the French Sarcoma Group (FSG) database (404 patients). RESULTS: The 90-day mortality rate was 8.6 and 4.5% in both cohorts. The logistic regression analysis retained performance status (PS; odds ratio (OR) = 3.83 if PS = 1, OR = 12.00 if PS >= 2), presence of liver metastasis (OR = 2.37) and rare site metastasis (OR = 2.00) as PFs for early death. The CHAID analysis retained PS as a major discriminator followed by histological grade (only for patients with PS >= 2). In both models, PS was the most powerful PF for 90-day mortality. CONCLUSION: Performance status has to be taken into account in the design of further clinical trials and is one of the most important parameters to guide patient management. For those patients with poor PS, expected benefits from therapy should be weighed up carefully against the anticipated toxicities. British Journal of Cancer (2011) 104, 1544-1550. doi: 10.1038/bjc.2011.136 www.bjcancer.com Published online 19 April 2011 (C) 2011 Cancer Research U

Screening for Vulnerability in Older Cancer Patients: The ONCODAGE Prospective Multicenter Cohort Study:

Background: Geriatric Assessment is an appropriate method for identifying older cancer patients at risk of life-threatening events during therapy. Yet, it is underused in practice, mainly because it is time- and resource-consuming. This study aims to identify the best screening tool to identify older cancer patients requiring geriatric assessment by comparing the performance of two short assessment tools the G8 and the Vulnerable Elders Survey (VES-13). Patients and Methods: The diagnostic accuracy of the G8 and the (VES-13) were evaluated in a prospective cohort study of 1674 cancer patients accrued before treatment in 23 health care facilities. 1435 were eligible and evaluable. Outcome measures were multidimensional geriatric assessment (MGA), sensitivity (primary), specificity, negative and positive predictive values and likelihood ratios of the G8 and VES-13, and predictive factors of 1-year survival rate. Results: Patient median age was 78.2 years (70-98) with a majority of females (69.8%), various types of cancer including 53.9% breast, and 75.8% Performance Status 0-1. Impaired MGA, G8, and VES-13 were 80.2%, 68.4%, and 60.2%, respectively. Mean time to complete G8 or VES-13 was about five minutes. Reproducibility of the two questionnaires was good. G8 appeared more sensitive (76.5% versus 68.7%, P5 0.0046) whereas VES-13 was more specific (74.3% versus 64.4%, P<0.0001). Abnormal G8 score (HR = 2.72), advanced stage (HR = 3.30), male sex (HR = 2.69) and poor Performance Status (HR = 3.28) were independent prognostic factors of 1-year survival. Conclusion: With good sensitivity and independent prognostic value on 1-year survival, the G8 questionnaire is currently one of the best screening tools available to identify older cancer patients requiring geriatric assessment, and we believe it should be implemented broadly in daily practice. Continuous research efforts should be pursued to refine the selection process of older cancer patients before potentially life-threatening therapy

Polarized Secretion of Drosophila EGFR Ligand from Photoreceptor Neurons Is Controlled by ER Localization of the Ligand-Processing Machinery

Trafficking within the endoplasmic reticulum and specialized localization of the intra-membrane protease Rhomboid regulate EGF ligand-dependent signaling in Drosophila photoreceptor axon termini