Learning the noise fingerprint of quantum devices

Noise sources unavoidably affect any quantum technological device. Noise's main features are expected to strictly depend on the physical platform on which the quantum device is realized, in the form of a distinguishable fingerprint. Noise sources are also expected to evolve and change over time. Here, we first identify and then characterize experimentally the noise fingerprint of IBM cloud-available quantum computers, by resorting to machine learning techniques designed to classify noise distributions using time-ordered sequences of measured outcome probabilities.Comment: 20 pages, 3 figures, 5 tables, research articl

Reconstruction of daily pressure maps over Italy during some extreme events of the 19th Century

The quality and availability of daily meteorological data for the reconstruction of atmospheric circulation over Italy in the period between the Italian political Unity (1860) and the development of the Central Office for Meteorology (1879) is studied. Examples of atmospheric circulation reconstructed for some extreme events are presented

Gastric Cancer: The Times they are a-changin’

Gastric cancer is the third leading cause of cancer death worldwide. Even though during these last decades gastric cancer incidence decreased in Western countries, it remains endemic and with a high incidence in Eastern countries. The survival in advanced and metastatic stage of gastric cancer is still very poor. Recently the Cancer Genoma Atlas Research Network identified four subtypes with different molecular profiles to classify gastric cancer in order to offer the optimal targeted therapies for pre-selected patients. Indeed, the key point is still the selection of patients for the right treatment, on basis of molecular tumor characterization. Since chemotherapy reached a plateau of efficacy for gastric cancer, the combination between cytotoxic therapy and biological agents gets a better prognosis and decreases chemotherapeutic toxicity. Currently, Trastuzumab in combination with platinum and fluorouracil is the only approved targeted therapy in the first line for c-erbB2 positive patients, whereas Ramucirumab is the only approved targeted agent for patients with metastatic gastric cancer. New perspectives for an effective treatment derived from the immunotherapeutic strategies. Here, we report an overview on gastric cancer treatments, with particular attention to recent advances in targeted therapies and in immunotherapeutic approach

Energy fluctuation relations and repeated quantum measurements

In this paper, we discuss the statistical description in non-equilibrium regimes of energy fluctuations originated by the interaction between a quantum system and a measurement apparatus applying a sequence of repeated quantum measurements. To properly quantify the information about energy fluctuations, both the exchanged heat probability density function and the corresponding characteristic function are derived and interpreted. Then, we discuss the conditions allowing for the validity of the fluctuation theorem in Jarzynski form 〈e−βQ〉=1, thus showing that the fluctuation relation is robust against the presence of randomness in the time intervals between measurements. Moreover, also the late-time, asymptotic properties of the heat characteristic function are analyzed, in the thermodynamic limit of many intermediate quantum measurements. In such a limit, the quantum system tends to the maximally mixed state (thus corresponding to a thermal state with infinite temperature) unless the system's Hamiltonian and the intermediate measurement observable share a common invariant subspace. Then, in this context, we also discuss how energy fluctuation relations change when the system operates in the quantum Zeno regime. Finally, the theoretical results are illustrated for the special cases of two- and three-levels quantum systems, now ubiquitous for quantum applications and technologies

Multiplicity of homoclinic orbits in quasi-linear autonomous Lagrangian systems

Abstract The existence of at least two homoclinic orbits is proved by A. Ambrosetti and V. Coti Zelati (Multiple homoclinic orbits for a class of conservative systems, Rend. Sem. Mat. Univ. Padova 89, 1993, 177-194) for autonomous Lagrangian systems where V : R m → R is a function of the form with W ∈ C 2 (R m , R) superquadratic, satisfying a "pinching" hypothesis and an hypothesis on its second derivative. The present work deals with potentials of the form W (q,q) that weakly depend onq. In this case an homoclinic orbit corresponds to a classical solution to the equation where Wi = ∂iW for i = 1, 2. 2000 MSC: 37J45, 58E50

Localización de hipocentros y determinación de su magnitud en Tierra del Fuego y zonas aledañas

New hypocentre locations of earthquakes with low to medium magnitude have been calculated in order to study Tierra del Fuego seismicity. The region has a complex tectonic setting: the island is crossed by a transforming fault named Magallanes-Fagnano which divides Tierra del Fuego in two continental blocks. This fault system constitutes the major continental segment of the South America-Scotia plate’s border. The island has an important seismological history which includes an event of magnitude 7.8 occurred on December 1949.Reports of earthquakes occurred in 1929, 1930, 1944, 1949 and 1970 are known by a study of historical seismicity. In this paper hypocentre locations and error analysis have been carried out. Records at five seismological stations have been analyzed during January-December 2007. More than 180 events have beenidentified and some of them were compared to events of NEIC (National Earthquake Information Center) and ISC (International Seismological Centre). Magnitude determinations have been calculated with first arrival amplitude. The majority of earthquakes have magnitude mb between 2 and 4 degrees. With respect to hypocentral depths, more than 50% of located earthquakes have their depths in the first 10 km. The seismicity map obtained shows that beyond rather dispersed seismicity related to the Magallanes-Fagnano fault, a concentration of epicentres is found in the Darwin Cordillera area and in the Scotia plate surrounding, displaying evidence of a correlation with the geotectonic area of studyNuevos hipocentros de sismos de baja a mediana magnitud han sido calculados con el fin de estudiar la sismicidad en la Isla de Tierra del Fuego y zonas aledañas. La región presenta un complejo escenario tectónico: la isla es atravesada por una falla transformante conocida como Falla de Magallanes-Fagnano la cual divide a Tierra del Fuego en dos bloques continentales. Esta falla constituye el mayor segmento continental del borde de las placas de Scotia y Sudamericana. La isla tiene una importante historia sismológica que incluye un evento de carácter destructivo ocurrido en diciembre de 1949 el cual alcanzó una magnitud de 7.8 en la escala de Richter.De un análisis de sismicidad histórica, se conocen reportes de sismos en los años 1929, 1930, 1944, 1949 y 1970. En el presente trabajo se ha realizado la localización de los hipocentros y el análisis de los errores en la determinación. A tal efecto se analizaron los registros de 5 estaciones sismológicas para el período enero 2007 – diciembre 2007. Más de 180 sismos fueron localizados y algunos de ellos comparados con los cinco eventos registrados por el NEIC (National Earthquake Information Center) y el ISC (Internacional Seismological Centre) para el mismo período. El cálculo de magnitud fue realizado a partir de la amplitud del primer arribo. La mayoría de los sismos tienen un valor de magnitud mb que se concentra entre 2 y 4 grados. Con respecto a la profundidad hipocentral, más del 50% de los eventos localizados tienen profundidades en los primeros 10 km. El mapa de sismicidad obtenido muestra una distribución de sismos sobre y en las cercanías de la falla Magallanes-Fagnano, una concentración de epicentros en el área de la Cordillera de Darwin y en los alrededores de la placa de Scotia, manifestando indicios de una correlación con el ambiente geotectónico del área de estudio

Antimicrobial susceptibility of Escherichia coli in bovines from intensive and extensive breeding interpretated by epidemiological cutoff values

Se estudió la “disminución de sensibilidad” o población “non-wild-type” (NWT) a diferentes antimicrobianos en 120 cepas de Escherichia coli, aisladas de materia fecal de bovinos de terminación aparentemente sanos, 60 cepas de bovinos de explotación intensiva (EI) y 60 cepas de bovinos de explotación extensiva (EE). Los antimicrobianos seleccionados son los frecuentemente utilizados en medicina veterinaria y humana. La sensibilidad antimicrobiana fue determinada por el método de concentración inhibitoria mínima (CIM) de dilución en agar. El criterio de interpretación fue establecido en base al punto de corte epidemiológico, epidemiological cutoff (ECOFF), epidemiological cutoff values (ECV) o wild type cutoff values (WCV). Las cepas de Escherichia coli aisladas de EI mostraron “disminución de sensibilidad” a tres familias de antimicrobianos: aminoglucósidos, tetraciclinas y fluorquinolonas, mientras que las cepas aisladas de EE a la familia de quinolonas y fluorquinolonas, coincidiendo con los antimicrobianos más utilizados en la explotación animal. Además se hallaron 16/60 cepas pertenecientes a la población NWT o con “disminución de sensibilidad” a cefotaxima aisladas en animales de EE.“Reduced susceptibility” or “non-wild-type” population (NWT) to different antimicrobial in 120 Escherichia coli strains, isolated from finishing bovines faeces of apparently healthy animals, 60 strains from intensive breeding bovines (EI) and 60 from extensive breeding (EE) bovines were studied. The selected antimicrobials are frequently used in veterinary and human medicine. The minimal inhibitory concentration was determined by agar dilution method. Interpretative criteria on the basis of epidemiological cutoff (ECOFF) epidemiological cutoff values (ECV) or wild type cutoff values (WCV) were established. Escherichia coli strains isolated from EI showed “reduced susceptibility” to three antimicrobial families: aminoglycosides, tetracyclines and fluorquinolones, whereas strains isolated from EE showed “reduced susceptibility” to quinolones and fluorquinolones families, coinciding with the antimicrobials most used in animal farms. In addition, 16/60 strains belonging to NWT population or with “reduced susceptibility” for cefotaxime isolated from EE animals were found.Facultad de Ciencias Veterinaria

Antimicrobial susceptibility of Escherichia coli in bovines from intensive and extensive breeding interpretated by epidemiological cutoff values

Se estudió la “disminución de sensibilidad” o población “non-wild-type” (NWT) a diferentes antimicrobianos en 120 cepas de Escherichia coli, aisladas de materia fecal de bovinos de terminación aparentemente sanos, 60 cepas de bovinos de explotación intensiva (EI) y 60 cepas de bovinos de explotación extensiva (EE). Los antimicrobianos seleccionados son los frecuentemente utilizados en medicina veterinaria y humana. La sensibilidad antimicrobiana fue determinada por el método de concentración inhibitoria mínima (CIM) de dilución en agar. El criterio de interpretación fue establecido en base al punto de corte epidemiológico, epidemiological cutoff (ECOFF), epidemiological cutoff values (ECV) o wild type cutoff values (WCV). Las cepas de Escherichia coli aisladas de EI mostraron “disminución de sensibilidad” a tres familias de antimicrobianos: aminoglucósidos, tetraciclinas y fluorquinolonas, mientras que las cepas aisladas de EE a la familia de quinolonas y fluorquinolonas, coincidiendo con los antimicrobianos más utilizados en la explotación animal. Además se hallaron 16/60 cepas pertenecientes a la población NWT o con “disminución de sensibilidad” a cefotaxima aisladas en animales de EE.“Reduced susceptibility” or “non-wild-type” population (NWT) to different antimicrobial in 120 Escherichia coli strains, isolated from finishing bovines faeces of apparently healthy animals, 60 strains from intensive breeding bovines (EI) and 60 from extensive breeding (EE) bovines were studied. The selected antimicrobials are frequently used in veterinary and human medicine. The minimal inhibitory concentration was determined by agar dilution method. Interpretative criteria on the basis of epidemiological cutoff (ECOFF) epidemiological cutoff values (ECV) or wild type cutoff values (WCV) were established. Escherichia coli strains isolated from EI showed “reduced susceptibility” to three antimicrobial families: aminoglycosides, tetracyclines and fluorquinolones, whereas strains isolated from EE showed “reduced susceptibility” to quinolones and fluorquinolones families, coinciding with the antimicrobials most used in animal farms. In addition, 16/60 strains belonging to NWT population or with “reduced susceptibility” for cefotaxime isolated from EE animals were found.Facultad de Ciencias Veterinaria