Bioerosion on a Terebratula scillae population from the Lower Pleistocene of Lecce area (Southern Italy)

This paper deals with shell bioerosion in a population of Terebratula scillae SEGUENZA from the Lower Pleistocene in Lecce area, Southern Italy. The most important traces belong to shell breakage attributed to predatory activity; borings (Entobia isp., Maeandropolydora isp.); drill holes (Oichnus simplex BROMLEY; Oichnus isp.); and etching scars (Centrichnus eccentricus BROMLEY and MARTINELL; Podichnus centrifugalis BROMLEY and SURLYK). The distribution analysis of the traces of epibiosis on the shells of T. scillae induces us to think that we are dealing with a pedicle-anchored form, living with completely raised valves. Besides, both percentage and nature of predation marks (probably due to gastropods or decapod crustaceans) do not depose for a very intense predation pressure.El presente artículo trata sobre la bioerosión en las conchas de una población de Terebratula scillae SEGUENZA del Pleistoceno inferior del área de Lecce, Sur de Italia. Las principales trazas pertenecen a roturas de la concha atribuidas a la actividad de depredadores; perforaciones (Entobia isp., Maeandropolydora isp.); agujeros (Oichnus simplex BROMLEY; Oichnus isp.); e impresiones (Centrichnus eccentricus BROMLEY and MARTINELL; Podichnus centrifugalis BROMLEY and SURLYK). El análisis de la distribución de las trazas de epibiosis sobre las conchas de T. scillae induce a pensar que se trata de una forma anclada mediante el pedículo, que vivía con las valvas completamente levantadas. Por otra parte, ni los porcentajes ni la naturaleza de las señales de depredación (probablemente debidas a gasterópodos o a crustáceos decápodos) indican una presión de depredación demasiado intensa

Bioerosion on a Terebratula scillae population from the Lower Pleistocene of Lecce area (Southern Italy)

This paper deals with shell bioerosion in a population of Terebratula scillae SEGUENZA from the Lower Pleistocene in Lecce area, Southern Italy. The most important traces belong to shell breakage attributed to predatory activity; borings (Entobia isp., Maeandropolydora isp.); drill holes (Oichnus simplex BROMLEY; Oichnus isp.); and etching scars (Centrichnus eccentricus BROMLEY and MARTINELL; Podichnus centrifugalis BROMLEY and SURLYK).The distribution analysis of the traces of epibiosis on the shells of T. scillae induces us to think that we are dealing with a pedicleanchored form, living with completely raised valves. Besides, both percentage and nature of predation marks (probably due to gastropods or decapod crustaceans) do not depose for a very intense predation pressure

Restructuring and Rebranding: The Need for Another Revolution in the Loire

International audienc

Crossed Andreev reflection-induced magnetoresistance

We show that very large negative magnetoresistance can be obtained in magnetic trilayers in a current-in-plane geometry owing to the existence of crossed Andreev reflection. This spin-valve consists of a thin superconducting film sandwiched between two ferromagnetic layers whose magnetization is allowed to be either parallelly or antiparallelly aligned. For a suitable choice of structure parameters and nearly fully spin-polarized ferromagnets the magnetoresistance can exceed -80%. Our results are relevant for the design and implementation of spintronic devices exploiting ferromagnet-superconductor structures.Comment: 5 pages, 4 figures, final published versio

Electronic implementations of Interaction-Free Measurements

Three different implementations of interaction-free measurements (IFMs) in solid-state nanodevices are discussed. The first one is based on a series of concatenated Mach-Zehnder interferometers, in analogy to optical-IFM setups. The second one consists of a single interferometer and concatenation is achieved in the time domain making use of a quantized electron emitter. The third implementation consists of an asymmetric Aharonov-Bohm ring. For all three cases we show that the presence of a dephasing source acting on one arm of the interferometer can be detected without degrading the coherence of the measured current. Electronic implementations of IFMs in nanoelectronics may play a fundamental role as very accurate and noninvasive measuring schemes for quantum devices.Comment: 12 pages, 10 figure

A computational approach for identifying the chemical factors involved in the glycosaminoglycans-mediated acceleration of amyloid fibril formation

BACKGROUND: Amyloid fibril formation is the hallmark of many human diseases, including Alzheimer's disease, type II diabetes and amyloidosis. Amyloid fibrils deposit in the extracellular space and generally co-localize with the glycosaminoglycans (GAGs) of the basement membrane. GAGs have been shown to accelerate the formation of amyloid fibrils in vitro for a number of protein systems. The high number of data accumulated so far has created the grounds for the construction of a database on the effects of a number of GAGs on different proteins. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we have constructed such a database and have used a computational approach that uses a combination of single parameter and multivariate analyses to identify the main chemical factors that determine the GAG-induced acceleration of amyloid formation. We show that the GAG accelerating effect is mainly governed by three parameters that account for three-fourths of the observed experimental variability: the GAG sulfation state, the solute molarity, and the ratio of protein and GAG molar concentrations. We then combined these three parameters into a single equation that predicts, with reasonable accuracy, the acceleration provided by a given GAG in a given condition. CONCLUSIONS/SIGNIFICANCE: In addition to shedding light on the chemical determinants of the protein∶GAG interaction and to providing a novel mathematical predictive tool, our findings highlight the possibility that GAGs may not have such an accelerating effect on protein aggregation under the conditions existing in the basement membrane, given the values of salt molarity and protein∶GAG molar ratio existing under such conditions

Blockade and Counterflow Supercurrent in exciton-condensate Josephson junctions

We demonstrate that perfect conversion between charged supercurrents in superconductors and neutral supercurrents in electron-hole pair condensates is possible via a new Andreev-like scattering mechanism. As a result, when two superconducting circuits are coupled through a bilayer exciton condensate, the superflow in both layers is drastically modified. Depending on the phase biases the supercurrents can be completely blocked or exhibit perfect drag.Comment: 4 pages, 2 figure

Developmental profiles of young children with autism spectrum disorder and global developmental delay: A study with the Griffiths III scales

The purpose of this study was to identify developmental profiles associated with autism spectrum disorder (ASD) and global developmental delay (DD) in pre-school aged Italian children. Developmental profiles were evaluated by means of a standardized tool widely used for the assessment of psychomotor development in early childhood, the Griffiths III scales, recently adapted and standardized for the Italian population. Specifically, we compared the Griffiths III profiles of children with ASD and DD (ASD + DD) with those of children with DD alone. Moreover, we inspected the psychometric function of single items by comparing children with ASD + DD and children with DD with typically developing (TD) children from the Griffiths III normative sample. In this way, we aimed to isolate the effects of each diagnostic class on psychomotor abilities and on the psychometric function of single items. The ASD + DD and DD groups were found to share the presence of lower age equivalent scores relative to their chronological age in all the developmental domains considered: Foundations of Learning, Language and Communication, Eye and Hand Coordination, Personal–Social-Emotional and Gross Motor Skills. However, the DD group displayed a homogeneous profile with similar levels of delay in all developmental domains, while children with ASD + DD exhibited relative weaknesses in the Language and Communication and Personal–Social-Emotional scales. The analysis of the psychometric function drawn for each item has confirmed different profiles in social-communicative and non-verbal items between the two diagnostic groups and in relation to TD normative sample. The Griffiths III is a valid psychometric tool for identifying atypical developmental profiles and its use may be recommended during the diagnostic process of ASD and DD, to detect specific strengths and weaknesses and guide person-centered treatment