Aperiodic Ising Quantum Chains

Some years ago, Luck proposed a relevance criterion for the effect of aperiodic disorder on the critical behaviour of ferromagnetic Ising systems. In this article, we show how Luck's criterion can be derived within an exact renormalisation scheme for Ising quantum chains with coupling constants modulated according to substitution rules. Luck's conjectures for this case are confirmed and refined. Among other outcomes, we give an exact formula for the correlation length critical exponent for arbitrary two-letter substitution sequences with marginal fluctuations of the coupling constants.Comment: 27 pages, LaTeX, 1 Postscript figure included, using epsf.sty and amssymb.sty (one error corrected, some minor changes

Limit-(quasi)periodic point sets as quasicrystals with p-adic internal spaces

Model sets (or cut and project sets) provide a familiar and commonly used method of constructing and studying nonperiodic point sets. Here we extend this method to situations where the internal spaces are no longer Euclidean, but instead spaces with p-adic topologies or even with mixed Euclidean/p-adic topologies. We show that a number of well known tilings precisely fit this form, including the chair tiling and the Robinson square tilings. Thus the scope of the cut and project formalism is considerably larger than is usually supposed. Applying the powerful consequences of model sets we derive the diffractive nature of these tilings.Comment: 11 pages, 2 figures; dedicated to Peter Kramer on the occasion of his 65th birthda

Algèbre diagrammatique et catégorification

Nous proposons une illustration diagrammatique abordable du concept de catégorification qui s’est développé au cours des vingt dernières années

Was sind Territorien in der Urgeschichte? Netzwerkanalysen als Annäherung an den Begriff des Raumes im Jungpaläolithikum

Addressed from the perspective of where they were obtained, lithic raw materials found in archaeological sites carry and contain data of geographical value. Thus, they are privileged witnesses to human movements in prehistoric times. By coupling the results of technological analyses with multi-scale diagnostic methodologies based on the principle of an evolutionary chain set up by some of us and recently optimised, today it is possible to evaluate the acquisition modes for raw materials, the manner of their introduction into sites, and better understand the prehistoric management of mineralogical resources. This techno-economic approach, becoming ever more precise, is being facilitated thanks to the results from a consortium of researchers interconnected in the ‘Réseau de lithothèques’ and ‘Silex’ projects.Detailed petro-archaeological studies of an archaeological series make it possible to identify litho-spaces that are not images of territories. Indeed, territories are not only shaped by economic constraints (where space is the basis of a society), but they are the way in which collectives build themselves by conferring meaning on places of singular use linked to each other by a complex network of values. Yet, the symbolic dimension of spaces is a central element in the cultural representations that societies have of it. Rather than limiting the analysis of the territories to the scale of a site, which in the context of nomadic societies is contradictory, it seems more efficient to analyse the relationships between places (i.e. networks of places). Taking as an example current or recently nomadic peoples – for whom networks in which materials circulate correspond to networks of places – we propose a method based on a concept of network analysis in order to escape the point of view based on single sites, and offer an approach to determining prehistoric territories. This side-step not only questions the spatial extent of archaeological records, but also their coherence as chrono-anthropological entities

The origin of early Acheulean expansion in Europe 700 ka ago: new findings at Notarchirico (Italy)

Notarchirico (Southern Italy) has yielded the earliest evidence of Acheulean settlement in Italy and four older occupation levels have recently been unearthed, including one with bifaces, extending the roots of the Acheulean in Italy even further back in time. New 40Ar/39Ar on tephras and ESR dates on bleached quartz securely and accurately place these occupations between 695 and 670 ka (MIS 17), penecontemporaneous with the Moulin-Quignon and la Noira sites (France). These new data demonstrate a very rapid expansion of shared traditions over Western Europe during a period of highly variable climatic conditions, including interglacial and glacial episodes, between 670 and 650 (i.e., MIS17/MIS16 transition). The diversity of tools and activities observed in these three sites shows that Western Europe was populated by adaptable hominins during this time. These conclusions question the existence of refuge areas during intense glacial stages and raise questions concerning understudied migration pathways, such as the Sicilian route

The origin of early Acheulean expansion in Europe 700 ka ago: new findings at Notarchirico (Italy)

Notarchirico (Southern Italy) has yielded the earliest evidence of Acheulean settlement in Italy and four older occupation levels have recently been unearthed, including one with bifaces, extending the roots of the Acheulean in Italy even further back in time. New 40Ar/39Ar on tephras and ESR dates on bleached quartz securely and accurately place these occupations between 695 and 670 ka (MIS 17), penecontemporaneous with the Moulin-Quignon and la Noira sites (France). These new data demonstrate a very rapid expansion of shared traditions over Western Europe during a period of highly variable climatic conditions, including interglacial and glacial episodes, between 670 and 650 (i.e., MIS17/MIS16 transition). The diversity of tools and activities observed in these three sites shows that Western Europe was populated by adaptable hominins during this time. These conclusions question the existence of refuge areas during intense glacial stages and raise questions concerning understudied migration pathways, such as the Sicilian route

The HIV-1 Integrase α4-Helix Involved in LTR-DNA Recognition Is also a Highly Antigenic Peptide Element

Monoclonal antibodies (MAbas) constitute remarkable tools to analyze the relationship between the structure and the function of a protein. By immunizing a mouse with a 29mer peptide (K159) formed by residues 147 to 175 of the HIV-1 integrase (IN), we obtained a monoclonal antibody (MAba4) recognizing an epitope lying in the N-terminal portion of K159 (residues 147–166 of IN). The boundaries of the epitope were determined in ELISA assays using peptide truncation and amino acid substitutions. The epitope in K159 or as a free peptide (pep-a4) was mostly a random coil in solution, while in the CCD (catalytic core domain) crystal, the homologous segment displayed an amphipathic helix structure (α4-helix) at the protein surface. Despite this conformational difference, a strong antigenic crossreactivity was observed between pep-a4 and the protein segment, as well as K156, a stabilized analogue of pep-a4 constrained into helix by seven helicogenic mutations, most of them involving hydrophobic residues. We concluded that the epitope is freely accessible to the antibody inside the protein and that its recognition by the antibody is not influenced by the conformation of its backbone and the chemistry of amino acids submitted to helicogenic mutations. In contrast, the AA →Glu mutations of the hydrophilic residues Gln148, Lys156 and Lys159, known for their interactions with LTRs (long terminal repeats) and inhibitors (

Low loss composite nano ferrite with matchning permittivity and permeability in UHF band

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