Estimative for the size of the compactification radius of a one extra dimension Universe

In this work, we use the Casimir effect to probe the existence of one extra dimension. We begin by evaluating the Casimir pressure between two plates in a $M^4\times S^1$ manifold, and then use an appropriate statistical analysis in order to compare the theoretical expression with a recent experimental data and set bounds for the compactification radius

Cosmological solutions in generalized hybrid metric-Palatini gravity

We construct exact solutions representing a Friedmann-Lema\^itre-Robsertson-Walker (FLRW) universe in a generalized hybrid metric-Palatini theory. By writing the gravitational action in a scalar-tensor representation, the new solutions are obtained by either making an ansatz on the scale factor or on the effective potential. Among other relevant results, we show that it is possible to obtain exponentially expanding solutions for flat universes even when the cosmology is not purely vacuum. We then derive the classes of actions for the original theory which generate these solutions.Comment: 14 pages, 17 figure

Localization of α-synuclein in teleost central nervous system: immunohistochemical and Western blot evidence by 3D5 monoclonal antibody in the common carp, Cyprinus carpio

Alpha synuclein (α-syn) is a 140 amino acid vertebrate-specific protein, highly expressed in the human nervous system and abnormally accumulated in Parkinson's disease and other neurodegenerative disorders, known as synucleinopathies. The common occurrence of α-syn aggregates suggested a role for α-syn in these disorders, although its biological activity remains poorly understood. Given the high degree of sequence similarity between vertebrate α-syns, we investigated this proteins in the CNS of the common carp Cyprinus carpio, with the aim of comparing its anatomical and cellular distribution with that of mammalian α-syn. The distribution of α-syn was analyzed by semiquantitative Western blot, immunohistochemistry and immunofluorescence by a novel monoclonal antibody (3D5) against a fully conserved epitope between carp and human α-syn. The distribution of 3D5 immunoreactivity was also compared with that of ChAT, TH and 5HT by double immunolabelings. Results show that α-syn-like protein of about 17 kDa is expressed to different levels in several brain regions and in the spinal cord. Immunoreactive materials were localized in neuronal perikarya and varicose fibers but not in the nucleus. Present findings indicate that α-syn-like proteins may be expressed in few subpopulations of catecholaminergic and serotoninergic neurons in the carp brain. However, evidence of cellular colocalization 3D5/TH or 3D5/5HT was rare. Differently, the same proteins appear to be co-expressed with ChAT by cholinergic neurons in several motor and reticular nuclei. These results sustain the functional conservation of the α-syn expression in cholinergic systems and suggest that α-syn modulates similar molecular pathways in phylogenetically distant vertebrates. This article is protected by copyright. All rights reserved

Boundedness of the Weyl fractional integral on one-sided weighted Lebesgue and Lipschitz spaces

In this paper we introduce the one-sided weighted spaces L−w (β), −1 <β< 1. The purpose of this definition is to obtain an extension of the Weyl fractional integral operator I+α from Lp w into a suitable weighted space. Under certain condition on the weight w, we have that L−w (0) coincides with the dual of the Hardy space H1 −(w). We prove for 0 <β< 1, that L− w (β) consists of all functions satisfying a weighted Lipschitz condition. In order to give another characterization of L− w (β), 0 ≤ β < 1, we also prove a one-sided version of John-Nirenberg Inequality. Finally, we obtain necessary and sufficient conditions on the weight w for the boundedness of an extension of I+ α from Lp w into L− w (β), −1 <β< 1, and its extension to a bounded operator from L− w (0) into L− w (α)

On the Dichotomy between the Nodal and Antinodal Excitations in High-temperature Superconductors

Angle-resolved photoemission data on optimally- and under-doped high temperature superconductors reveal a dichotomy between the nodal and antinodal electronic excitations. In this paper we propose an explanation of this unusual phenomenon by employing the coupling between the quasiparticle and the commensurate/incommensurate magnetic excitations.Comment: 11 pages, 9 figure