Trinification, the Hierarchy Problem and Inverse Seesaw Neutrino Masses

In minimal trinification models light neutrino masses can be generated via a radiative see-saw mechanism, where the masses of the right-handed neutrinos originate from loops involving Higgs and fermion fields at the unification scale. This mechanism is absent in models aiming at solving or ameliorating the hierarchy problem, such as low-energy supersymmetry, since the large seesaw-scale disappears. In this case, neutrino masses need to be generated via a TeV-scale mechanism. In this paper, we investigate an inverse seesaw mechanism and discuss some phenomenological consequences.Comment: 10 pages, 11 figure

Testen wir relevantes Wissen?

Das Professionswissen von Lehrkräften wird als wichtige Voraussetzung für gutes und erfolgreiches Unterrichten diskutiert. Professionswissenstests werden daher oft mit dem Ziel eingesetzt, Aussagen über die Wirksamkeit der Lehrerausbildung zu treffen. Die Handlungsrelevanz explizierbaren Wissens ist allerdings nicht empirisch abgesichert, was die Validität solcher Aussagen einschränkt. Ziel der hier vorgestellten Studie war die Überprüfung der prädiktiven Validität der im Projekt "ProwiN" entwickelten Tests zur Erfassung des Fachwissens sowie des fachdidaktischen und pädagogischen Wissens von Physiklehrkräften in Bezug auf gutes und erfolgreiches Unterrichten. Hierfür wurden Zusammenhänge zwischen dem Professionswissen von 23 Lehrkräften, der kognitiv aktivierenden Gestaltung ihres Unterrichts und dem Fachwissenserwerb und situationalen Interesse ihrer Schülerinnen und Schüler analysiert. Die Ergebnisse deuten darauf hin, dass auf Basis der üblichen Validierungsmaßnahmen für Professionswissenstests (Expertenbefragungen, Vergleich bekannter Gruppen, Zusammenhangsanalysen zwischen Professionswissensdimensionen), nicht davon ausgegangen werden kann, dass handlungsrelevantes Wissen für gutes und erfolgreiches Unterrichten erfasst wird. Eine intensive Auseinandersetzung mit den Einschränkungen der vorgestellten Studie macht deutlich, wie wichtig - aber auch wie problematisch - die Untersuchung der Zusammenhänge zwischen Professionswissen, Unterrichtsqualität und Unterrichtserfolg ist

Commande d'un réseau d'antennes actives par couplage d'oscillateurs

National audienceDans les domaines des radiocommunications, le contrôle conjoint de l'orientation et de la formation des diagrammes de rayonnement augmente considérablement la qualité de la communication. En effet, des points clés tels que la répartition de la puissance émise et le rapport Signal/Bruit sont améliorés. Cette commande de l'orientation est réalisée en contrôlant la phase injectée sur chacun des éléments rayonnants qui constitue le réseau. Une des techniques consiste à coupler des oscillateurs entre eux, et ce papier présente la conception d'un prototype ainsi que les résultats expérimentaux qui valident un outil de CAO développé au sein de notre laboratoire

A 2.4 GHz 1-Dimensional Array Antenna driven by Vector Modulators

International audienceThis paper aims to develop an intelligent radio-communication prototype using multiple-antenna phased array whose bearing can be controlled electronically. Such a system has proved its efficiency in terms of gain and SNR improvement. The architecture presented in this article runs at 2.4 GHz with a bandwidth channel of 11 MHz which is well suited for WIFI 802.11b applications. This original system uses quadrature modulators as active phase-shifters, and noise sensitivity is studied and simulated to prove the interest of this architecture. A circuit is under tests and first elementary active parts RF measurements are given

Precision measurement of the CKM parameter sin() with the LHCb experiment

This thesis presents a decay-time dependent measurement of CP violation in the decay of B0 and B0-bar mesons into their common J/ψ KS final state. The CP observables S(J/ψ KS) and C(J/ψ KS) allow access to the magnitude of the symmetry violation in the interference between the B meson decay and mixing amplitudes and can directly be related to the CKM angle β. Using a dataset of selected signal B0 to J/ψ KS candidates corresponding to an integrated luminosity of 3.0 fb-1 collected at centre-of-mass energies of 7 and 8 TeV by the LHCb experiment, the CP observables are measured to be S(J/ψ KS) = -0.731 ± 0.035 (stat) ± 0.020 (syst), C(J/ψ KS) = -0.038 ± 0.032 (stat) ± 0.005 (syst), resulting in the worlds most precise measurement of these quantities at a hadron collider. With the parameter C(J/ψ S) fixed to zero, S(J/ψ KS) equals sin(2β) = 0.746 ± 0.030 (stat). The results have a similar precision as previous measurements at the B factories Babar and Belle and are consistent with these and with expectations from measurements of other CKM matrix parameters.Die vorliegende Dissertation beschreibt eine zerfallszeitabhängige Messung von CP-Verletzung im Zerfall von B0- und Anti-B0-Mesonen in ihren gemeinsamen Endzustand J/ψ KS. Die Größe der Symmetrieverletzung in der Interferenz der Zerfalls- und Mischungs-Amplituden der B-Mesonen lässt sich durch die CP-Observablen S(J/ψ KS) und C(J/ψ KS) ausdrücken und mit dem CKM-Winkel β in Bezug setzen. Die Messung wurde auf einem Datensatz von selektierten B0 nach J/ψ KS Signal-Kandidaten durchgeführt, der einer integrierten Luminosität von 3.0 fb-1 entspricht und bei Schwerpunktsenergien von 7 und 8 TeV am LHCb-Experiment aufgenommen wurde. Mit S(J/ψ KS) = -0.731 ± 0.035 (stat) ± 0.020 (syst), C(J/ψ KS) = -0.038 ± 0.032 (stat) ± 0.005 (syst), wurden die CP-Observablen mit einer Genauigkeit gemessen, die weltweit bisher an keinem anderen hadronischen Beschleuniger erreicht werden konnte. Unter der Annahme von C(J/ψ KS) = 0 folgt S(J/ψ KS) = sin(2β) = 0.746 ± 0.030 (stat). Die Ergebnisse sind von ähnlicher Präzision wie bisherige Messungen an den B-Fabriken Babar und Belle und sind bestens vereinbar mit diesen und Erwartungen aus Messungen von anderen CKM-Matrix-Parametern

Antenna Arrays Principle and Solutions: Robust Control Approach

This paper treats solutions on the ability of a chain of non identical oscillators to drive antenna arrays. Frequency approaches were studied in order to solve the problem of synchronization of the oscillators. However, in this article, a new structure of chain of oscillators is introduced. Secondly, Lyapunov theory of stability is used to design a dynamical controller guarantying the oscillators synchronization. The problem of synchronization is transformed into a problem of asymptotic stabilization for a nonlinear system. It is formulated as a system of linear matrix inequalities where the parameter variations of the two oscillators and their differences are modeled by polytopic matrices. The theoretical result is successfully applied to an array of transistor-based oscillators used in "smart antenna" systems

Time-Varying Delay Passivity Analysis in 4 GHz Antennas Array Design

International audienceIn this paper, a new approach for synchronization of dynamical networks with time-delays is proposed. It is based on stability theory of coupled time-delayed dynamical systems. Some new criteria for stability analysis which ensure the synchronization of the networks are analytically derived. Conditions for synchronization,in the form of Linear Matrix Inequality, are established. They use the Lyapunov and Krasovskii stability theories. In this approach, parameter uncertainties are introduced in the network model. Numerical simulations show the efficiency of the proposed synchronization analysis. A network of 4-GHz smart antenna array is used and analyzed in some details. This array provides a control of the direction of the radiation pattern

Robust synchronization of different coupled oscillators: Application to antenna arrays

International audienceThis paper deals with the synchronization of a chain of nonlinear and uncertain models of nonidentical oscillators. Using Lyapunov's theory of stability, a dynamical controller guaranteeing the synchronization of the oscillators is determined. The problem of synchronization is transformed into a problem of asymptotic stabilization for a nonlinear system and then is formulated as a system of linear matrix inequalities where the parameter variations of the two oscillators and their differences are modeled by polytopic matrices. The theoretical result is successfully applied to an array of transistor-based oscillators used in "smart antenna" systems

Structure of the intergenic spacers in chicken ribosomal DNA

International audienceAbstractBackgroundRibosomal DNA (rDNA) repeats are situated in the nucleolus organizer regions (NOR) of chromosomes and transcribed into rRNA for ribosome biogenesis. Thus, they are an essential component of eukaryotic genomes. rDNA repeat units consist of rRNA gene clusters that are transcribed into single pre-rRNA molecules, each separated by intergenic spacers (IGS) that contain regulatory elements for rRNA gene cluster transcription. Because of their high repeat content, rDNA sequences are usually absent from genome assemblies. In this work, we used the long-read sequencing technology to describe the chicken IGS and fill the knowledge gap on rDNA sequences of one of the key domesticated animals.MethodsWe used the long-read PacBio RSII technique to sequence the BAC clone WAG137G04 (Wageningen BAC library) known to contain chicken NOR elements and the HGAP workflow software suit to assemble the PacBio RSII reads. Whole-genome sequence contigs homologous to the chicken rDNA repetitive unit were identified based on the Gallus_gallus-5.0 assembly with BLAST. We used the Geneious 9.0.5 and Mega software, maximum likelihood method and Chickspress project for sequence evolution analysis, phylogenetic tree construction and analysis of the raw transcriptome data.ResultsThree complete IGS sequences in the White Leghorn chicken genome and one IGS sequence in the red junglefowl contig AADN04001305.1 (Gallus_gallus-5.0) were detected. They had various lengths and contained three groups of tandem repeats (some of them being very GC rich) that form highly organized arrays. Initiation and termination sites of rDNA transcription were located within small and large unique regions (SUR and LUR), respectively. No functionally significant sites were detected within the tandem repeat sequences.ConclusionsDue to the highly organized GC-rich repeats, the structure of the chicken IGS differs from that of IGS in human, apes, Xenopus or fish rDNA. However, the chicken IGS shares some molecular organization features with that of the turtles, which are other representatives of the Sauropsida clade that includes birds and reptiles. Our current results on the structure of chicken IGS together with the previously reported ribosomal gene cluster sequence provide sufficient data to consider that the complete chicken rDNA sequence is assembled with confidence in terms of molecular DNA organization

Differences in Enzymatic Properties of the Saccharomyces kudriavzevii and Saccharomyces uvarum Alcohol Acetyltransferases and Their Impact on Aroma-Active Compounds Production

Higher alcohols and acetate esters belong to the most important yeast secondary metabolites that significantly contribute to the overall flavor and aroma profile of fermented products. In Saccharomyces cerevisiae, esterification of higher alcohols is catalyzed mainly by the alcohol acetyltransferases encoded by genes ATF1 and ATF2. Previous investigation has shown other Saccharomyces species, e.g., S. kudriavzevii and S. uvarum, to vary in aroma-active higher alcohols and acetate esters formation when compared to S. cerevisiae. Here, we aimed to analyze the enzymes encoded by the ATF1 and ATF2 genes from S. kudriavzevii (SkATF1, SkATF2) and S. uvarum (SuATF1, SuATF2). The heterologous expression of the individual ATF1 and ATF2 genes in a host S. cerevisiae resulted in the enhanced production of several higher alcohols and acetate esters. Particularly, an increase of 2-phenylethyl acetate production by the strains that harbored ATF1 and ATF2 genes from S. kudriavzevii and S. uvarum was observed. When grown with individual amino acids as the nitrogen source, the strain that harbored SkATF1 showed particularly high 2-phenylethyl acetate production and the strains with introduced SkATF2 or SuATF2 revealed increased production of isobutyl acetate, isoamyl acetate, and 2-phenylethyl acetate compared to the reference strains with endogenous ATF genes. The alcohol acetyltransferase activities of the individual Atf1 and Atf2 enzymes measured in the cell extracts of the S. cerevisiae atf1 atf2 iah1 triple-null strain were detected for all the measured substrates. This indicated that S. kudriavzevii and S. uvarum Atf enzymes had broad range substrate specificity as S. cerevisiae Atf enzymes. Individual Atf1 enzymes exhibited markedly different kinetic properties since SkAtf1p showed c. twofold higher and SuAtf1p c. threefold higher Km for isoamyl alcohol than ScAtf1p. Together these results indicated that the differences found among the three Saccharomyces species during the aroma-active acetate ester formation may be due, to some extent, to the distinct properties of Atf enzymes.This work has been supported by the European Commission FP7: Marie Curie Initial Network CORNUCOPIA no. 264717 and by CICYT grant (ref. AGL2015-67504-C3-1-R) from Ministerio de Economía y Competitividad.Peer reviewedPeer Reviewe