Compact extra dimensions in cosmologies with f(T) structure

The presence of compact extra dimensions in cosmological scenarios in the context of f(T)-like gravities is discussed. For the case of toroidal compactifications, the analysis is performed in an arbitrary number of extra dimensions. Spherical topologies for the extra dimensions are then carefully studied in six and seven spacetime dimensions, where the proper vielbein fields responsible for the parallelization process are found.Comment: 11 pages, one figure (added). Typos corrected, manuscript improved. Additional material is contained in section IV. Accepted for publication in Physical Review

Fotomodellazione e stereofotogrammetria per la creazione di modelli stratigrafici in archeologia dell’architettura

Architectural structures are 3D volumes and their features, which are recognized in the field through archaeological investigation (stratigraphic, metric and formal data), are distributed within the three-dimensions. Stratigraphic wall analysis normally needs front elevations or photo-mosaic images to draw the boundaries between each Stratigraphic Unit (SU). The Stratigraphic 3D component is not recorded because it is not taken into account by these supporting documents. With the support of photo-modelling and stereophotogrammetry, instead, it is possible to record the perimeter and volume of each SU in 3D space and also obtain isomorphic reproductions of the detected object. These copies are high quality photo-textured models that provide a complete overview of architectural volumes and the close dimensional framework (length, depth and width) of mouldings and decorative architectural elements. Moreover, the coordinates of any point can be extracted from these models in order to obtain traditional charts (maps, sections, elevations and axonometric views, useful to understand the process of installation of building elements). The purpose of this paper is to describe different techniques capable of acquiring 3D data of wall stratigraphy in order to define new methods of documentation based on the use of photo-modelling and stereophotogrammetry. The data used for this research refer to excavated sites or high-preserved fabrics of different ages and functions such as the late medieval bell-tower of the basilica of San Severo (Classe, Ravenna), the modern tower of Monte Erno (FC) and the church of San Bartolomeo in Tipano (FC). Starting with these cases, in this article we explore some of the technical aspects of data processing like speed, measurement accuracy, information content and equipment cost

The B -- TAU FCNC connection in SUSY Unified Theories

In the context of SUSY grand unification a link is established between the hadronic and leptonic soft breaking sectors. Such relation is here exploited in particular for FCNC processes in B physics. It is shown how bounds on leptonic FCNC involving the third generation translate into constraints on FC B decays. In the second part of the contribution we show that tests of lepton universality in K and B decays can represent an interesting handle to obtain relevant information on the amount of FCNC in the second and third fermion generation.Comment: 9 pages, 4 figures. Based on talks given at: DIF06, International Workshop on discoveries in flavour physics at e+e- colloders, Laboratori Nazionali di Frascati (Italy), February 28- March 03, 2006; XLIst Rencontres de Moriond, La Thuile, 5-11 March 2006; CORFU2005, Corfu Summer Institute on EPP, Corfu, Greece, September 4-26, 200

Peptide-induced negative selection of thymocytes activates transcription of an NF-kappa B inhibitor

Negative selection eliminates thymocytes bearing autoreactive T cell receptors (TCR) via an apoptotic mechanism. We have cloned an inhibitor of NF-kappa B, I kappa BNS, which is rapidly expressed upon TCR-triggered but not dexamethasone- or gamma irradiation-stimulated thymocyte death. The predicted protein contains seven ankyrin repeats and is homologous to I kappa B family members. In class I and class II MHC-restricted TCR transgenic mice, transcription of I kappa BNS is stimulated by peptides that trigger negative selection but not by those inducing positive selection (i.e., survival) or nonselecting peptides. I kappa BNS blocks transcription from NF-kappa B reporters, alters NF-kappa B electrophoretic mobility shifts, and interacts with NF-kappa B proteins in thymic nuclear lysates following TCR stimulation. Retroviral transduction of I kappa BNS in fetal thymic organ culture enhances TCR-triggered cell death consistent with its function in selection

Food chains and value system: the case of potato, fruit, and cheese

The aim of the paper is to analyse patterns of value system sharing along food chains, so to explore the agro-food enterprises capacity to be competitive and sustainable. The research focused on three food chains: potato, fruit, and Grana cheese of Emilia Romagna region. The paper adopts the value system approach. The methodology is aimed at creating a consolidated financial statement for each food chain so to re-create the chain operating profit and identify how this is shared among the different food chain stages. The analysis is carried out on 189 enterprises for the potato chain, 187 for the fruit chain and 203 for the cheese chain. The number of enterprises was invariable over the 5 year 2003-2007, leading to some 2,900 financial statement analysis. The chains analysed show differences. In the potato and fruit chains 35% of value is created by distribution, whereas in cheese chain only 13.6%. Over the five years value decreases 5% in fruit and potato and 9% in cheese. The lack of adequate strategic food chain partnership allows an increasing retail market power over the whole chain at the expenses of the primary sector entailing a declining sustainability for all chain actors.food chain, value system, profitability, potato, fruit, cheese, Agricultural and Food Policy,

On the existence of 0/1 polytopes with high semidefinite extension complexity

In Rothvo\ss{} it was shown that there exists a 0/1 polytope (a polytope whose vertices are in \{0,1\}^{n}) such that any higher-dimensional polytope projecting to it must have 2^{\Omega(n)} facets, i.e., its linear extension complexity is exponential. The question whether there exists a 0/1 polytope with high PSD extension complexity was left open. We answer this question in the affirmative by showing that there is a 0/1 polytope such that any spectrahedron projecting to it must be the intersection of a semidefinite cone of dimension~2^{\Omega(n)} and an affine space. Our proof relies on a new technique to rescale semidefinite factorizations

The regular cosmic string in Born-Infeld gravity

It is shown that Born-Infeld gravity --a high energy deformation of Einstein gravity-- removes the singularities of a cosmic string. The respective vacuum solution results to be free of conical singularity and closed timelike curves. The space ends at a minimal circle where the curvature invariants vanish; but this circle cannot be reached in a finite proper time.Comment: 4 pages, submitted to Proceedings of Spanish Relativity Meeting 2010 (ERE2010, Granada, Spain

Paleobathymetric and paleoenvironmental reconstruction of the Oligocene and Miocene deposits of southern Caribbean (Carmen de Bolivar, Colombia) based on benthic foraminifera

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