631 research outputs found

    Dimensional Reduction without Extra Continuous Dimensions

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    We describe a novel approach to dimensional reduction in classical field theory. Inspired by ideas from noncommutative geometry, we introduce extended algebras of differential forms over space-time, generalized exterior derivatives and generalized connections associated with the "geometry" of space-times with discrete extra dimensions. We apply our formalism to theories of gauge- and gravitational fields and find natural geometrical origins for an axion- and a dilaton field, as well as a Higgs field.Comment: 23 page

    Why misinformation is reported: evidence from a warning and a source-monitoring task

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    People report suggested misinformation about a previously witnessed event for manifold reasons, such as social pressure, lack of memory of the original aspect, or a firm belief to remember the misinformation from the witnessed event. In our experiments (N = 429), which follow Loftus's paradigm, we tried to disentangle the reasons for reporting a central and a peripheral piece of misinformation in a recognition task by examining (a) the impact a warning about possible misinformation has on the error rate, and (b) whether once reported misinformation was actually attributed to the witnessed event in a later source-monitoring (SM) task. Overall, a misinformation effect was found for both items. The warning strongly reduced the misinformation effect, but only for the central item. In contrast, reports of the peripheral misinformation were correctly attributed to the misinformation source or, at least, ascribed to guesswork much more often than the central ones. As a consequence, after the SM task, the initially higher error rate for the peripheral item was even lower than that of the central item. Results convincingly show that the reasons for reporting misinformation, and correspondingly also the potential to avoid them in legal settings, depend on the centrality of the misinformation. © 2016 Informa UK Limited, trading as Taylor & Francis Group

    Photoselektive Vaporisation der Prostata: Erfahrungen mit Prostataadenomen >80cm3

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    Zusammenfassung: Hintergrund: Wir berichten ĂĽber unsere Erfahrungen mit der photoselektiven Vaporisation der Prostata (PVP) bei Patienten mit symptomatischer benigner Prostatahyperplasie (BPH) und Prostataadenomen >80cm3. Patienten und Methode: 201Patienten mit BPH wurden in die Studie eingeschlossen; 51 (25,4%) Patienten hatten ein Prostatavolumen >80cm3 und 150 (74,6%) Patienten ein Volumen 80cm3 stellt die PVP eine durchfĂĽhrbare Therapieoption da

    Diagnostik und Therapie der Harnleitersteinkolik

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    Summary: Acute ureteral colic presents with a complex of acute and characteristic flank pain that usually indicates the presence of a stone in the urinary tract. Diagnosis and management of renal colic have undergone considerable evolution and advancement in recent years. The application of noncontrast helical computed tomography (CT) in patients with suspected ureteral colic is one major advance in the primary diagnostic process. The superior sensitivity and specificity of helical CT allow ureterolithiasis to be diagnosed without the potential side effects of contrast media. Initial management is based on three key concepts: (A) rational and fast diagnostic process (B) effective pain control (C) and understanding of the impact of stone location and size on the natural course of the disease and definitive urologic management. These concepts are discussed in this review with reference to contemporary literatur

    Phenomenology of Mirror Fermions in the Littlest Higgs Model with T-Parity

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    Little Higgs models are an interesting alternative to explain electroweak symmetry breaking without fine-tuning. Supplemented with a discrete symmetry (T-parity) constraints from electroweak precision data are naturally evaded and also a viable dark matter candidate is obtained. T-parity implies the existence of new (mirror) fermions in addition to the heavy gauge bosons of the little Higgs models. In this paper we consider the effects of the mirror fermions on the phenomenology of the littlest Higgs model with T-parity at the LHC. We study the most promising production channels and decay chains for the new particles. We find that the mirror fermions have a large impact on the magnitude of signal rates and on the new physics signatures. Realistic background estimates are given.Comment: 13 p

    Isospin Violation in Chiral Perturbation Theory and the Decays \eta \ra \pi \ell \nu and \tau \ra \eta \pi \nu

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    I discuss isospin breaking effects within the standard model. Chiral perturbation theory presents the appropriate theoretical framework for such an investigation in the low--energy range. Recent results on the electromagnetic contributions to the masses of the pseudoscalar mesons and the Kℓ3K_{\ell 3} amplitudes are reported. Using the one--loop formulae for the ηℓ3\eta_{\ell 3} form factors, rather precise predictions for the decay rates of η→πℓν\eta \rightarrow \pi \ell \nu can be obtained. Finally, I present an estimate of the \tau \ra \eta \pi \nu branching ratio derived from the dominant meson resonance contributions to this decay.Comment: 10 pages, latex, one figure available upon reques

    B0 -> D*- a1+: Chirality tests and resolving an ambiguity in 2\beta+\gamma

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    We point out that the decays of B mesons into a vector meson and an axial-vector meson can distinguish between left and right-handed polarized mesons, in contrast to decays into two vector mesons. Measurements in B0 -> D*-a1+ are proposed for testing factorization and the V-A structure of the weak b -> c current, and for resolving a discrete ambiguity in 2\beta + \gamma.Comment: 4 page

    Mechanism of virus attenuation by codon pair deoptimization

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    Codon pair deoptimization is an efficient virus attenuation strategy, but the mechanism that leads to attenuation is unknown. The strategy involves synthetic recoding of viral genomes that alters the positions of synonymous codons, thereby increasing the number of suboptimal codon pairs and CpG dinucleotides in recoded genomes. Here we identify the molecular mechanism of codon pair deoptimization-based attenuation by studying recoded influenza A viruses. We show that suboptimal codon pairs cause attenuation, whereas the increase of CpG dinucleotides has no effect. Furthermore, we show that suboptimal codon pairs reduce both mRNA stability and translation efficiency of codon pair-deoptimized genes. Consequently, reduced protein production directly causes virus attenuation. Our study provides evidence that suboptimal codon pairs are major determinants of mRNA stability. Additionally, it demonstrates that codon pair bias can be used to increase mRNA stability and protein production of synthetic genes in many areas of biotechnology
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