315 research outputs found

    Environmental factors and effects on breeding performances and housing in small laboratory rodents: A technical report

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    Based on their professional experience in large scale production of laboratory rodents, the authors report on some documented cases showing the effects of environmental factors on reproductive performances of the rodent strains they produce. Beyond continuation of the effect of a Simple environmental factor (temperature, light) the reported cases show that environmental effects must not be systematically generalized to several strains or, even less, to several species.Moreover, the incidence of associated (complex) factors, which cannot be evaluated without the opportunity of having a control sample must be emphasized. This last point is of major importance when comparing results coming from different laboratories although the maintain environmental factors are a priori identical

    Production of the Superconducting Matching Quadrupoles for the LHC Insertions

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    The LHC insertions are equipped with individually powered superconducting quadrupole assemblies comprising several quadrupole magnets and orbit correctors, and range in length from 5.3 m to 11.3 m. Following the initial experience in the assembly of the pre-series cold masses, the production has advanced well and about half of the total of 82 units has been produced at CERN. In this paper we present the experience gained in steering the cold mass production, in particular with respect to the alignment requirements. We also report on the field quality and other measurements made for assuring the quality of the quadrupoles

    The Construction of the Superconducting Matching Quadrupoles for the LHC Insertions

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    After several years of effort, the construction of the superconducting matching quadrupoles for the LHC insertions is nearing completion. We retrace the main events of the project from the initial development of the quadrupole magnets of several types to the series production of over 100 complex superconducting magnets, and report on the techniques developed for steering of the production. The main performance parameters for the full series, such as quench training, field quality and magnet geometry are presented. The experience gained in the production of these special superconducting magnets is of considerable value for further development of the LHC insertions

    Divisible E-Cash from Constrained Pseudo-Random Functions

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    International audienceElectronic cash (e-cash) is the digital analogue of regular cash which aims at preservingusers’ privacy. Following Chaum’s seminal work, several new features were proposed for e-cash toaddress the practical issues of the original primitive. Among them,divisibilityhas proved very usefulto enable efficient storage and spendings. Unfortunately, it is also very difficult to achieve and, todate, quite a few constructions exist, all of them relying on complex mechanisms that can only beinstantiated in one specific setting. In addition security models are incomplete and proofs sometimeshand-wavy.In this work, we first provide a complete security model for divisible e-cash, and we study the linkswith constrained pseudo-random functions (PRFs), a primitive recently formalized by Boneh andWaters. We exhibit two frameworks of divisible e-cash systems from constrained PRFs achievingsome specific properties: either key homomorphism or delegability. We then formally prove theseframeworks, and address two main issues in previous constructions: two essential security notionswere either not considered at all or not fully proven. Indeed, we introduce the notion ofclearing,which should guarantee that only the recipient of a transaction should be able to do the deposit,and we show theexculpability, that should prevent an honest user to be falsely accused, was wrongin most proofs of the previous constructions. Some can easily be repaired, but this is not the casefor most complex settings such as constructions in the standard model. Consequently, we providethe first construction secure in the standard model, as a direct instantiation of our framework

    Design, Synthesis and Discovery of N,N'-Carbazoyl-aryl-urea Inhibitors of Zika NS5 Methyltransferase and Virus Replication

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    The recent outbreaks of Zika virus (ZIKV) infection worldwide make the discovery of novel antivirals against flaviviruses a research priority. This work describes the identification of novel inhibitors of ZIKV through a structure‐based virtual screening approach using the ZIKV NS5‐MTase. A novel series of molecules with a carbazoyl‐aryl‐urea structure has been discovered and a library of analogues has been synthesized. The new compounds inhibit ZIKV MTase with IC50 between 23–48 ΌM. In addition, carbazoyl‐aryl‐ureas also proved to inhibit ZIKV replication activity at micromolar concentration

    Long-term follow-up after endoscopic resection for superficial esophageal squamous cell carcinoma: a multicenter Western studyAbstract

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    Background Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are the first-line treatments for superficial esophageal squamous cell carcinoma (SCC). This study aimed to compare long-term clinical outcome and oncological clearance between EMR and ESD for the treatment of superficial esophageal SCC. Methods We conducted a retrospective multicenter study in five French tertiary care hospitals. Patients treated by EMR or ESD for histologically proven superficial esophageal SCC were included consecutively. Results Resection was performed for 148 tumors (80 EMR, 68 ESD) in 132 patients. The curative resection rate was 21.3 % in the EMR group and 73.5 % in the ESD group (P < 0.001). The recurrence rate was 23.7 % in the EMR group and 2.9 % in the ESD group (P = 0.002). The 5-year recurrence-free survival rate was 73.4 % in the EMR group and 95.2 % in the ESD group (P = 0.002). Independent factors for cancer recurrence were resection by EMR (hazard ratio [HR] 16.89, P = 0.01), tumor infiltration depth ≄ m3 (HR 3.28, P = 0.02), no complementary treatment by chemoradiotherapy (HR 7.04, P = 0.04), and no curative resection (HR 11.75, P = 0.01). Risk of metastasis strongly increased in patients with tumor infiltration depth ≄ m3, and without complementary chemoradiotherapy (P = 0.02). Conclusion Endoscopic resection of superficial esophageal SCC was safe and efficient. Because it was associated with an increased recurrence-free survival rate, ESD should be preferred over EMR. For tumors with infiltration depths ≄ m3, chemoradiotherapy reduced the risk of nodal or distal metastasis

    Crystal structure of the RNA polymerase domain of the West Nile Virus non-structural protein 5

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    Viruses of the family Flaviviridae are important human and animal pathogens. Among them, the Flaviviruses dengue ( DENV) and West Nile ( WNV) cause regular outbreaks with fatal outcomes. The RNA-dependent RNA polymerase ( RdRp) activity of the non-structural protein 5 ( NS5) is a key activity for viral RNA replication. In this study, crystal structures of enzymatically active and inactive WNV RdRp domains were determined at 3.0- and 2.35-angstrom resolution, respectively. The determined structures were shown to be mostly similar to the RdRps of the Flaviviridae members hepatitis C and bovine viral diarrhea virus, although with unique elements characteristic for the WNVRdRp. Using a reverse genetic system, residues involved in putative interactions between the RNA-cap methyltransferase ( MTase) and the RdRp domain of Flavivirus NS5 were identified. This allowed us to propose a model for the structure of the full-length WNV NS5 by in silico docking of the WNV MTase domain ( modeled from our previously determined structure of the DENV MTase domain) onto the RdRp domain. The Flavivirus RdRp domain structure determined here should facilitate both the design of anti-Flavivirus drugs and structure-function studies of the Flavivirus replication complex in which the multifunctional NS5 protein plays a central role

    Policy-Based Sanitizable Signatures

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    Sanitizable signatures are a variant of signatures which allow a single, and signer-defined, sanitizer to modify signed messages in a controlled way without invalidating the respective signature. They turned out to be a versatile primitive, proven by different variants and extensions, e.g., allowing multiple sanitizers or adding new sanitizers one-by-one. However, existing constructions are very restricted regarding their flexibility in specifying potential sanitizers. We propose a different and more powerful approach: Instead of using sanitizers\u27 public keys directly, we assign attributes to them. Sanitizing is then based on policies, i.e., access structures defined over attributes. A sanitizer can sanitize, if, and only if, it holds a secret key to attributes satisfying the policy associated to a signature, while offering full-scale accountability
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