An Efficient, Movable Single-Particle Detector for Use in Cryogenic Ultra-High Vacuum Environments

A compact, highly efficient single-particle counting detector for ions of keV/u kinetic energy, movable by a long-stroke mechanical translation stage, has been developed at the Max-Planck-Institut f\"ur Kernphysik (Max Planck Institute for Nuclear Physics, MPIK). Both, detector and translation mechanics, can operate at ambient temperatures down to $\sim$ 10 K and consist fully of ultra-high vacuum (UHV) compatible, high-temperature bakeable and non-magnetic materials. The set-up is designed to meet the technical demands of MPIK's Cryogenic Storage Ring (CSR). We present a series of functional tests that demonstrate full suitability for this application and characterise the set-up with regard to its particle detection efficiency.Comment: 12 pages, 9 figures, version accepted for publication in Review of Scientific Instrument

Results of time-of-flight transmission measurements for 197Au at a 50 m station of GELINA

Transmission measurements have been performed at the time-of-flight facility GELINA to determine the total cross section for neutron induced reactions in 197Au. The measurements have been carried out at a 50 m transmission station of GELINA with the accelerator operating at 800 Hz. This report provides the experimental details required to deliver the data to the EXFOR data library which is maintained by the Nuclear Data Section of the IAEA and the Nuclear Energy Agency of the OECD. The experimental conditions and data reduction procedures are described. In addition, the full covariance information based on the AGS concept is given such that nuclear reaction model parameters together with their covariances can be derived in a least squares adjustment to the data.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

Deinococcus glutaminyl-tRNA synthetase is a chimer between proteins from an ancient and the modern pathways of aminoacyl-tRNA formation

Glutaminyl-tRNA synthetase from Deinococcus radiodurans possesses a C-terminal extension of 215 residues appending the anticodon-binding domain. This domain constitutes a paralog of the Yqey protein present in various organisms and part of it is present in the C-terminal end of the GatB subunit of GatCAB, a partner of the indirect pathway of Gln-tRNA(Gln) formation. To analyze the peculiarities of the structure–function relationship of this GlnRS related to the Yqey domain, a structure of the protein was solved from crystals diffracting at 2.3 Å and a docking model of the synthetase complexed to tRNA(Gln) constructed. The comparison of the modeled complex with the structure of the E. coli complex reveals that all residues of E. coli GlnRS contacting tRNA(Gln) are conserved in D. radiodurans GlnRS, leaving the functional role of the Yqey domain puzzling. Kinetic investigations and tRNA-binding experiments of full length and Yqey-truncated GlnRSs reveal that the Yqey domain is involved in tRNA(Gln) recognition. They demonstrate that Yqey plays the role of an affinity-enhancer of GlnRS for tRNA(Gln) acting only in cis. However, the presence of Yqey in free state in organisms lacking GlnRS, suggests that this domain may exert additional cellular functions

Explaining Counterexamples with Giant-Step Assertion Checking

International audienceIdentifying the cause of a proof failure during deductive verification of programs is hard: it may be due to an incorrectness in the program, an incompleteness in the program annotations, or an incompleteness of the prover. The changes needed to resolve a proof failure depend on its category, but the prover cannot provide any help on the categorisation. When using an SMT solver to discharge a proof obligation, that solver can propose a model from a failed attempt, from which a possible counterexample can be derived. But the counterexample may be invalid, in which case it may add more confusion than help. To check the validity of a counterexample and to categorise the proof failure, we propose the comparison between the run-time assertion-checking (RAC) executions under two different semantics, using the counterexample as an oracle. The first RAC execution follows the normal program semantics, and a violation of a program annotation indicates an incorrectness in the program. The second RAC execution follows a novel "giant-step" semantics that does not execute loops nor function calls but instead retrieves return values and values of modified variables from the oracle. A violation of the program annotations only observed under giant-step execution characterises an incompleteness of the program annotations. We implemented this approach in the Why3 platform for deductive program verification and evaluated it using examples from prior literature

Determination of the 338 eV, 1098 eV and 1370 eV s-wave resonance parameters for neutron induced reactions of 55Mn at GELINA

In this report new values for the resonance parameters of the 338 eV, 1098 eV and 1370 eV s-wave resonances of 55Mn are presented. The parameters were derived from a resonance shape analysis of transmission and capture data resulting from measurements at the time-of-flight facility GELINA. Special samples have been prepared to optimize the transmission at the resonance dips, to avoid the impact of sample inhomogeneities and to reduce bias effects due to multiple interaction events and the normalization of the capture data. The parameters have been adopted in an ENDF-6 compatible file which has been tested and implemented in the next release of the Joint Evaluated Fission and Fusion data library, i.e. JEFF-3.2, which is maintained by the Nuclear Energy Agency of the OECD.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

Results of time-of-flight transmission measurements for 63,65Cu and natCu at a 50 m station of GELINA

Transmission measurements have been performed at the time-of-flight facility GELINA to determine neutron resonance parameters for 63Cu and 65Cu. The experiments have been carried out at a 50 m transmission station at a moderated neutron beam using a Li-glass scintillator with the accelerator operating at 800 Hz. Measurements were performed with a natCu metallic sample and metallic samples enriched in 63Cu and 65Cu. This report describes the experimental details required to deliver the experimental transmission to the EXFOR data library which is maintained by the Nuclear Energy Agency of the OECD and the Nuclear Data Section of the IAEA. The experimental conditions and data reduction procedures are described. In addition, the full covariance information based on the AGS concept is given, such that resonance parameters together with their covariances can be derived in a least squares adjustment to the data.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

MMP-3 deficiency alleviates endotoxin-induced acute inflammation in the posterior eye segment

Matrix metalloproteinase-3 (MMP-3) is known to mediate neuroinflammatory processes by activating microglia, disrupting blood-central nervous system barriers and supporting neutrophil influx into the brain. In addition, the posterior part of the eye, more specifically the retina, the retinal pigment epithelium (RPE) and the blood-retinal barrier, is affected upon neuroinflammation, but a role for MMP-3 during ocular inflammation remains elusive. We investigated whether MMP-3 contributes to acute inflammation in the eye using the endotoxin-induced uveitis (EIU) model. Systemic administration of lipopolysaccharide induced an increase in MMP-3 mRNA and protein expression level in the posterior part of the eye. MMP-3 deficiency or knockdown suppressed retinal leukocyte adhesion and leukocyte infiltration into the vitreous cavity in mice subjected to EIU. Moreover, retinal and RPE mRNA levels of intercellular adhesion molecule 1 (Icam1), interleukin 6 (Il6), cytokine-inducible nitrogen oxide synthase (Nos2) and tumor necrosis factor alpha (Tnf alpha), which are key molecules involved in EIU, were clearly reduced in MMP-3 deficient mice. In addition, loss of MMP-3 repressed the upregulation of the chemokines monocyte chemoattractant protein (MCP)-1 and (C-X-C motif) ligand 1 (CXCL1). These findings suggest a contribution of MMP-3 during EIU, and its potential use as a therapeutic drug target in reducing ocular inflammation

JRC support to JAEA on the development of neutron resonance densitometry

The activities carried out during 2013 at the Institute for Reference Materials and Measurements of the Joint Research Centre of the European Commission to support the Japan Atomic Energy Agency in the development of Neutron Resonance Densitometry are described. These activities include experiments carried out at the time-of-flight facility GELINA, development of a model to account for sample inhomogeneities, assistance in data reduction and analysis procedures, preparation of test samples, training of JAEA staff and dissemination of the results.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard