Mechanism for bipolar resistive switching in transition metal oxides

We introduce a model that accounts for the bipolar resistive switching phenomenom observed in transition metal oxides. It qualitatively describes the electric field-enhanced migration of oxygen vacancies at the nano-scale. The numerical study of the model predicts that strong electric fields develop in the highly resistive dielectric-electrode interfaces, leading to a spatially inhomogeneous oxygen vacancies distribution and a concomitant resistive switching effect. The theoretical results qualitatively reproduce non-trivial resistance hysteresis experiments that we also report, providing key validation to our model.Comment: Accepted for publication in Physical Review B, 6 twocolumn pages, 5 figure

HfO2 based memory devices with rectifying capabilities

We report on the fabrication and characterization of metal/insulator/metal capacitor like devices, with both rectifying and hysteretic features. Devices are formed by two junctions, Ti/HfO2 and Co/HfO2. Each junction exhibits highly repetitive hysteretic I-V curves with a sharp transition from a high to a low resistance state (3–4 orders of magnitude jump). The opposite transition (from low to high) is induced by polarity reversal. The rectifying non-crossing characteristics of the I-V branches denote their potential use as a multifunctional device, acting as a built-in rectifier and memory cell in a single device. Based on the phenomenological model description by Zazpe et al. [Appl. Phys. Lett. 103, 073114 (2013)], we propose a circuital equivalent representation supported on switchable rectifying junctions. By exploring different electrode connections, we disentangle the role of the bulk transport in HfO2 devices.Fil: Quinteros, Cynthia Paula. Comisión Nacional de Energía Atómica. Gerencia del Área Investigaciones y Aplicaciones no Nucleares; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zaspe, R.. CIC nanoGUNE; EspañaFil: Marlasca, F. G.. Comisión Nacional de Energía Atómica. Gerencia del Área Investigaciones y Aplicaciones no Nucleares; ArgentinaFil: Golmar, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Industrial; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Casanova, F.. CIC nanoGUNE; España. Fundación Vasca para la Ciencia; EspañaFil: Stoliar, Pablo Alberto. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Centre National de la Recherche Scientifique; Francia. Universite de Nantes; FranciaFil: Hueso, L.. Fundación Vasca para la Ciencia; España. CIC nanoGUNE; EspañaFil: Levy, Pablo Eduardo. Comisión Nacional de Energía Atómica. Gerencia del Área Investigaciones y Aplicaciones no Nucleares; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Recent advances on information transmission and storage assisted by noise

The interplay between nonlinear dynamic systems and noise has proved to be of great relevance in several application areas. In this presentation, we focus on the areas of information transmission and storage. We review some recent results on information transmission through nonlinear channels assisted by noise. We also present recent proposals of memory devices in which noise plays an essential role. Finally, we discuss new results on the influence of noise in memristors.Comment: To be published in "Theory and Applications of Nonlinear Dynamics: Model and Design of Complex Systems", Proceedings of ICAND 2012 (Springer, 2014

Ancient DNA evidence for the ecological globalization of cod fishing in medieval and post-medieval Europe

Horizon 2020(H2020)FISHARC-IF 658022Bioarchaeolog

Hepatic alterations and induction of micronuclei in rainbow trout (Oncorhynchus mykiss) exposed to a textile industry effluent

Rainbow trout, Oncorhynchus mykiss, were exposed to a sublethal dose of a wool shrinkproofing effluent for 15, 30, 45 and 60 days. Liver and blood samples were taken after the exposure time together with samples of control handled fish. A light and electron microscope study was carried out to evaluate the histopathological lesions induced in the liver of treated fish. The genotoxic potential of the effluent was assessed by piscine micronucleus test. Vacuolation of liver bile preductular cells was observed in all exposed fish; abnormal lipid accumulation and basophilic foci were seen in the liver of one 30-days- and one 45-days-exposed fish, respectively. These specific alterations could be related to a pre-carcinogenic process. On the contrary, other lesions also described in all treated fish such as dilatation, vesiculation and degranulation of the rough endoplasmic reticulum, altered mitochondria, increase in myelin bodies and lysosomes and presence of phagosomes in wandering macrophages might be considered as non-specific alterations, similar to those described in fish exposed to different pollutants. Frequencies of micronucleated peripheral erythrocytes showed a significant increase following 30-days exposure

Hepatic alterations and induction of micronuclei in rainbow trout Oncorhynchus mykiss exposed to a textile industry effluent

Rainbow trout, Oncorhynchus mykiss, were exposed to a sublethal dose of a wool shrinkproofing effluent for 15, 30, 45 and 60 days. Liver and blood samples were taken after the exposure time together with samples of control handled fish. A light and electron microscope study was carried out to evaluate the histopathological lesions induced in the liver of treated fish. The genotoxic potential of the effluent was assessed by piscine micronucleus test. Vacuolation of liver bile preductular cells was observed in all exposed fish; abnormal lipid accumulation and basophilic foci were seen in the liver of one 30-days- and one 45-days-exposed fish, respectively. These specific alterations could be related to a pre-carcinogenic process. On the contrary, other lesions also described in all treated fish such as dilatation, vesiculation and degranulation of the rough endoplasmic reticulum, altered mitochondria, increase in myelin bodies and lysosomes and presence of phagosomes in wandering macrophages might be considered as non-specific alterations, similar to those described in fish exposed to different pollutants. Frequencies of micronucleated peripheral erythrocytes showed a significant increase following 30-days exposure

Dressel 21-22 Italic amphorae for fish: the archaeozoological confirmation from the garum shop at Pompeii

Between 2008 and 2012, a joint project called ‘Fishing and Fish-processing at Pompeii and Herculaneum’ explored the exploitation of marine resources in the region around mount Vesuvius in the Roman period. All available evidence for the marine species fished and consumed in the area (from iconography to archaeozoological remains), the fishing tackle, the areas used for processing and preparing fish, and the local/regional ceramic vessels (mainly amphorae and urcei) used for trading with fish marine foodstuffs were collected and analyzed. Field work was conducted in the so-called Garum Shop or Bottega del Garum (1, 12, 8), the only place clearly being used at the time of the Plinian eruption in AD 79 for the preparation and sale of fish preserves. An exceptional deposit of around one hundred complete amphorae, stored in the second courtyard of the Garum shop (room 13), known as the ‘pila d’anfore’, was analyzed; most of these containers belonged to the Dr. 21-22 family. The deposit was dug, analyzed in detail and partially published. The importance of this deposit is that for the first time we were able to demonstrate Botte’s hypothesis, that these italic amphorae were used for the bottling of fish products and not dried fruit. Most of the Dr. 21-22 contained archaeozoological remains, as they had been emptied just before the eruption (scales, vertebrae and other fish bones attached to their walls). The archaeozoological study carried out determined the existence of different fish-families (Clupeidae, Engraulidae, Carangidae, Scombridae and Sparidae); especially interesting is the connection of these archaeozoological remains with the tituli picti that refer to the palaeocontent (mainly MAL, SP and COP but also AB, CE, COP AB and VR are known) of the amphorae. Based on this evidence, we can argue that these are not abbreviations of fish names as previously assumed, but products manufactured with the said species, as in many cases the same fish species are associated with amphorae bearing different inscriptions. In this paper, the ichthyological palaeocontent of 8 amphorae from the ‘Pila d’Anfore’ is presented in detail, which confirms the use primarily of two taxa as the main ingredients (picarel — Spicara smaris and anchovy — Engraulis encrasicolus). These data verify the relation

The application of systematic sampling strategies for bioarchaeological studies in the Early Neolithic lakeshore site of La Draga (Banyoles, Spain)

Seeufersiedlung - Feuchtboden - Samplin

La alimentación en una granja púnica de Cerdeña

Excavation of the Punic farm at Truncu’e Molas (Terralba, Sardinia) in the summer of 2007 allowed us to recover a substantial amount of pottery and stone artefacts as well as bio-archaeological remains, despite the partial destruction of the site. These now enable us to study the different food preparation techniques in use in this Punic rural context during the 4th-3rd centuries B.C. The so-called cooking pots, casseroles and tannur offer information about cooking methods, while the bio-archaeological remains suggest that the site’s inhabitants had specialised in wine-production and obtained much of their food from the surroundings area