229 research outputs found

    Transient Thermo-Mechanical Analysis of the TPSG4 Beam Diluter

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    A new extraction channel is being built in the Super Proton Synchrotron (SPS) Long Straight Section 4 (LSS4) to transfer proton beams to the Large Hadron Collider (LHC) and also to the CERN Neutrino to Gran Sasso (CNGS) target. The beam is extracted in a fast mode during a single turn. For this purpose a protection of the MSE copper septum coil, in the form of a beam diluting element placed upstream, will be required to cope with the new failure modes associated with the fast extraction operation. The present analysis focuses on the thermo-mechanical behavior of the proposed TPSG4 diluter element irradiated by a fast extracted beam (up to 4.9 x 10^13 protons per 7.2 mus pulse) from the SPS. The deposited energy densities, estimated from primary and secondary particle simulations using the high-energy particle transport code FLUKA, were converted to internal heat generation rates taken as a thermal load input for the finite-element engineering analyses code ANSYS. According to the time dependence of the extracted beam, the transient solutions were obtained for coupled heat transfer, structural deformation, and shock wave problems. The results are given for the space distribution and the time evolution of temperatures and stresses in the most critical parts of the TPSG4 beam diluting element followed by the MSE copper septum coil. In the worst case of impact of the full LHC ultimate beam, the maximum temperatures remain safely below the melting point. However, the maximum equivalent stresses may slightly exceed the elastic limit in the aluminium section of the diluter. Also, the predicted maximum temperature rise in the MSE septum coil exceeds the design value

    A dimensionally continued Poisson summation formula

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    We generalize the standard Poisson summation formula for lattices so that it operates on the level of theta series, allowing us to introduce noninteger dimension parameters (using the dimensionally continued Fourier transform). When combined with one of the proofs of the Jacobi imaginary transformation of theta functions that does not use the Poisson summation formula, our proof of this generalized Poisson summation formula also provides a new proof of the standard Poisson summation formula for dimensions greater than 2 (with appropriate hypotheses on the function being summed). In general, our methods work to establish the (Voronoi) summation formulae associated with functions satisfying (modular) transformations of the Jacobi imaginary type by means of a density argument (as opposed to the usual Mellin transform approach). In particular, we construct a family of generalized theta series from Jacobi theta functions from which these summation formulae can be obtained. This family contains several families of modular forms, but is significantly more general than any of them. Our result also relaxes several of the hypotheses in the standard statements of these summation formulae. The density result we prove for Gaussians in the Schwartz space may be of independent interest.Comment: 12 pages, version accepted by JFAA, with various additions and improvement

    Genetic Basis for Resistance Against Viral Nervous Necrosis: GWAS and Potential of Genomic Prediction Explored in Farmed European Sea Bass (Dicentrarchus labrax)

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    Viral nervous necrosis (VNN) is an infectious disease caused by the red-spotted grouper nervous necrosis virus (RGNNV) in European sea bass and is considered a serious concern for the aquaculture industry with fry and juveniles being highly susceptible. To understand the genetic basis for resistance against VNN, a survival phenotype through the challenge test against the RGNNV was recorded in populations from multiple year classes (YC2016 and YC2017). A total of 4,851 individuals from 181 families were tested, and a subset (n∼1,535) belonging to 122 families was genotyped using a ∼57K Affymetrix Axiom array. The survival against the RGNNV showed low to moderate heritability with observed scale estimates of 0.18 and 0.25 obtained using pedigree vs. genomic information, respectively. The genome-wide association analysis showed a strong signal of quantitative trait loci (QTL) at LG12 which explained ∼33% of the genetic variance. The QTL region contained multiple genes (ITPK1, PLK4, HSPA4L, REEP1, CHMP2, MRPL35, and SCUBE) with HSPA4L and/or REEP1 genes being highly relevant with a likely effect on host response in managing disease-associated symptoms. The results on the accuracy of predicting breeding values presented 20–43% advantage in accuracy using genomic over pedigree-based information which varied across model types and applied validation schemes.publishedVersio

    On the key expansion of D(n, K)-based cryptographical algorithm

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    The family of algebraic graphs D(n, K) defined over finite commutative ring K have been used in different cryptographical algorithms (private and public keys, key exchange protocols). The encryption maps correspond to special walks on this graph. We expand the class of encryption maps via the use of edge transitive automorphism group G(n, K) of D(n, K). The graph D(n, K) and related directed graphs are disconnected. So private keys corresponding to walks preserve each connected component. The group G(n, K) of transformations generated by an expanded set of encryption maps acts transitively on the plainspace. Thus we have a great difference with block ciphers, any plaintexts can be transformed to an arbitrarily chosen ciphertex by an encryption map. The plainspace for the D(n, K) graph based encryption is a free module P over the ring K. The group G(n, K) is a subgroup of Cremona group of all polynomial automorphisms. The maximal degree for a polynomial from G(n, K) is 3. We discuss the Diffie-Hellman algorithm based on the discrete logarithm problem for the group τ-1Gτ, where τ is invertible affine transformation of free module P i.e. polynomial automorphism of degree 1. We consider some relations for the discrete logarithm problem for G(n, K) and public key algorithm based on the D(n, K) graphs

    Introducing the DizzyQuest: an app-based diary for vestibular disorders

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    BACKGROUND Most questionnaires currently used for assessing symptomatology of vestibular disorders are retrospective, inducing recall bias and lowering ecological validity. An app-based diary, administered multiple times in daily life, could increase the accuracy and ecological validity of symptom measurement. The objective of this study was to introduce a new experience sampling method (ESM) based vestibular diary app (DizzyQuest), evaluate response rates, and to provide examples of DizzyQuest outcome measures which can be used in future research. METHODS Sixty-three patients diagnosed with a vestibular disorder were included. The DizzyQuest consisted of four questionnaires. The morning- and evening-questionnaires were administered once each day, the within-day-questionnaire 10 times a day using a semi-random time schedule, and the attack questionnaire could be completed after the occurrence of a vertigo or dizziness attack. Data were collected for 4~weeks. Response rates and loss-to-follow-up were determined. Reported symptoms in the within-day-questionnaire were compared within and between patients and subgroups of patients with different vestibular disorders. RESULTS Fifty-one patients completed the study period. Average response rates were significantly higher than the desired response rate of \textgreater 50% (p \textless 0.001). The attack-questionnaire was used 159 times. A variety of neuro-otological symptoms and different disease profiles were demonstrated between patients and subgroups of patients with different vestibular disorders. CONCLUSION The DizzyQuest is able to capture vestibular symptoms within their psychosocial context in daily life, with little recall bias and high ecological validity. The DizzyQuest reached the desired response rates and showed different disease profiles between subgroups of patients with different vestibular disorders. This is the first time ESM was used to assess daily symptoms and quality of life in vestibular disorders, showing that it might be a useful tool in this population

    THE FREQUENCIES OF HAPTOGLOBIN TYPES IN FIVE POPULATIONS *

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    Haptoglobin types have been determined by starch gel electrophoresis of blood from five populations. The gene frequencies obtained for allele Hp 1 were as follows: American whites, 043; American Negroes, 0.59; African Negroes, 0.72; Apaches, 0.59; and Asiatic Indians, 0.18. In tribes of the Ivory Coast and Liberia, there was a suggestion of a cline which parallels that for haemoglobin S. Evidence is presented that the condition of ahaptoglobinemia is under genetic control but not by a gene allelic to the Hp 1 -Hp 2 series. The importance of the ahaptoglobinemic individuals for genetic studies and the possibility of selection in the maintenance of the genetic polymorphism are discussed. The authors wish to acknowledge the excellent assistance of Alojzia Sandor, who carried out the electrophoretic separations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66263/1/j.1469-1809.1958.tb01460.x.pd

    Steel septum magnets for the LHC beam injection and extraction

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    The Large Hadron Collider (LHC) will be a superconducting accelerator and collider to be installed in the existing underground LEP ring tunnel at CERN. It will provide proton-proton collisions with a centre of mass energy of 14 TeV. The proton beams coming from the SPS will be injected into the LHC at 450 GeV by vertically deflecting kicker magnets and horizontally deflecting steel septum magnets (MSI). The proton beams will be dumped from the LHC with the help of two extraction systems comprising horizontally deflecting kicker magnets and vertically deflecting steel septum magnets (MSD). The MSI and MSD septa are laminated iron-dominated magnets using an all welded construction. The yokes are constructed from two different half cores, called coil core and septum core. The septum cores comprise circular holes for the circulating beams. This avoids the need for careful alignment of the usually wedge-shaped septum blades used in classical Lambertson magnets. The MSI and MSD septum magnets were designed and built in a collaboration between IHEP (Protvino) and CERN (Geneva). This paper presents the magnet design, the experience gathered during the preseries construction, and gives the results of detailed magnetic measurements of the MSIB and MSDC preseries magnets

    The Functional Head Impulse Test to Assess Oscillopsia in Bilateral Vestibulopathy

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    Introduction: Bilateral vestibulopathy (BV) is a chronic condition in which vestibular function is severely impaired or absent on both ears. Oscillopsia is one of the main symptoms of BV. Oscillopsia can be quantified objectively by functional vestibular tests, and subjectively by questionnaires. Recently, a new technique for testing functionally effective gaze stabilization was developed: the functional Head Impulse Test (fHIT). This study compared the fHIT with the Dynamic Visual Acuity assessed on a treadmill (DVAtreadmill) and Oscillopsia Severity Questionnaire (OSQ) in the context of objectifying the experience of oscillopsia in patients with BV.Methods: Inclusion criteria comprised: (1) summated slow phase velocity of nystagmus of <20°/s during bithermal caloric tests, (2) torsion swing tests gain of <30% and/or phase <168°, and (3) complaints of oscillopsia and/or imbalance. During the fHIT (Beon Solutions srl, Italy) patients were seated in front of a computer screen. During a passive horizontal head impulse a Landolt C optotype was shortly displayed. Patients reported the seen optotype by pressing the corresponding button on a keyboard. The percentage correct answers was registered for leftwards and rightwards head impulses separately. During DVAtreadmill patients were positioned on a treadmill in front of a computer screen that showed Sloan optotypes. Patients were tested in static condition and in dynamic conditions (while walking on the treadmill at 2, 4, and 6 km/h). The decline in LogMAR between static and dynamic conditions was registered for each speed. Every patient completed the Oscillopsia Severity Questionnaire (OSQ).Results: In total 23 patients were included. This study showed a moderate correlation between OSQ outcomes and the fHIT [rightwards head rotations (rs = −0.559; p = 0.006) leftwards head rotations (rs = −0.396; p = 0.061)]. No correlation was found between OSQ outcomes and DVAtreadmill, or between DVAtreadmill and fHIT. All patients completed the fHIT, 52% of the patients completed the DVAtreadmill on all speeds.Conclusion: The fHIT seems to be a feasible test to quantify oscillopsia in BV since, unlike DVAtreadmill, it correlates with the experienced oscillopsia measured by the OSQ, and more BV patients are able to complete the fHIT than DVAtreadmill

    High Differentiation among Eight Villages in a Secluded Area of Sardinia Revealed by Genome-Wide High Density SNPs Analysis

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    To better design association studies for complex traits in isolated populations it's important to understand how history and isolation moulded the genetic features of different communities. Population isolates should not “a priori” be considered homogeneous, even if the communities are not distant and part of a small region. We studied a particular area of Sardinia called Ogliastra, characterized by the presence of several distinct villages that display different history, immigration events and population size. Cultural and geographic isolation characterized the history of these communities. We determined LD parameters in 8 villages and defined population structure through high density SNPs (about 360 K) on 360 unrelated people (45 selected samples from each village). These isolates showed differences in LD values and LD map length. Five of these villages show high LD values probably due to their reduced population size and extreme isolation. High genetic differentiation among villages was detected. Moreover population structure analysis revealed a high correlation between genetic and geographic distances. Our study indicates that history, geography and biodemography have influenced the genetic features of Ogliastra communities producing differences in LD and population structure. All these data demonstrate that we can consider each village an isolate with specific characteristics. We suggest that, in order to optimize the study design of complex traits, a thorough characterization of genetic features is useful to identify the presence of sub-populations and stratification within genetic isolates
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