Maximum population transfer in a periodically driven two-level system

We study the dynamics of a two-level quantum system under the influence of sinusoidal driving in the intermediate frequency regime. Analyzing the Floquet quasienergy spectrum, we find combinations of the field parameters for which population transfer is optimal and takes place through a series of well defined steps of fixed duration. We also show how the corresponding evolution operator can be approximated at all times by a very simple analytical expression. We propose this model as being specially suitable for treating periodic driving at avoided crossings found in complex multi-level systems, and thus show a relevant application of our results to designing a control protocol in a realistic molecular modelComment: 7 pages, 6 figure

Obesity dependent metabolic signatures associated with nonalcoholic fatty liver disease progression

Our understanding of the mechanisms by which nonalcoholic fatty liver disease (NAFLD) progresses from simple steatosis to steatohepatitis (NASH) is still very limited. Despite the growing number of studies linking the disease with altered serum metabolite levels, an obstacle to the development of metabolome-based NAFLD predictors has been the lack of large cohort data from biopsy-proven patients matched for key metabolic features such as obesity. We studied 467 biopsied individuals with normal liver histology (n=90) or diagnosed with NAFLD (steatosis, n=246; NASH, n=131), randomly divided into estimation (80% of all patients) and validation (20% of all patients) groups. Qualitative determinations of 540 serum metabolite variables were performed using ultra-performance liquid chromatography coupled to mass spectrometry (UPLCMS). The metabolic profile was dependent on patient body-mass index (BMI), suggesting that the NAFLD pathogenesis mechanism may be quite different depending on an individual’s level of obesity. A BMI-stratified multivariate model based on the NAFLD serum metabolic profile was used to separate patients with and without NASH. The area under the receiver operating characteristic curve was 0.87 in the estimation and 0.85 in the validation group. The cutoff (0.54) corresponding to maximum average diagnostic accuracy (0.82) predicted NASH with a sensitivity of 0.71 and a specificity of 0.92 (negative/positive predictive values = 0.82/0.84). The present data, indicating that a BMI-dependent serum metabolic profile may be able to reliably distinguish NASH from steatosis patients, have significant implications for the development of NASH biomarkers and potential novel targets for therapeutic intervention

The Poincare-Birkhoff theorem in Quantum Mechanics

Quantum manifestations of the dynamics around resonant tori in perturbed Hamiltonian systems, dictated by the Poincar\'e--Birkhoff theorem, are shown to exist. They are embedded in the interactions involving states which differ in a number of quanta equal to the order of the classical resonance. Moreover, the associated classical phase space structures are mimicked in the quasiprobability density functions and their zeros.Comment: 5 pages, 3 figures, Full resolution figures available at http://www.df.uba.ar/users/wisniaki/publications.htm

A 0535+26: an X-ray/Optical Tour

We compiled X-ray and Optical observations of the accreting X-ray binary system A 0535+262 since its discovery in 1975, that will allow us to shed light on the unpredictable behavior of this binary system. We present the data in terms of the Be-disk interaction with the neutron star companion. In addition, we show recent results from the continuous monitoring of this source by the Gamma-ray Burst Monitor(GBM), on board the Fermi observatory, since its launch in 2008 June 11.Comment: 4 pages, 5 figures, Conference proceeding of "Astrophysics of Neutron Stars 2010 - a conference in honor of M. Ali Alpar", 2-6 August 2010, Cesme, Izmir, Turke

Earth Occultation Imaging of the Low Energy Gamma-Ray Sky with GBM

The Earth Occultation Technique (EOT) has been applied to Fermi's Gamma-ray Burst Monitor (GBM) to perform all-sky monitoring for a predetermined catalog of hard X-ray/soft gamma-ray sources. In order to search for sources not in the catalog, thus completing the catalog and reducing a source of systematic error in EOT, an imaging method has been developed -- Imaging with a Differential filter using the Earth Occultation Method (IDEOM). IDEOM is a tomographic imaging method that takes advantage of the orbital precession of the Fermi satellite. Using IDEOM, all-sky reconstructions have been generated for ~sim 4 years of GBM data in the 12-50 keV, 50-100 keV and 100-300 keV energy bands in search of sources otherwise unmodeled by the GBM occultation analysis. IDEOM analysis resulted in the detection of 57 sources in the 12-50 keV energy band, 23 sources in the 50-100 keV energy band, and 7 sources in the 100-300 keV energy band. Seventeen sources were not present in the original GBM-EOT catalog and have now been added. We also present the first joined averaged spectra for four persistent sources detected by GBM using EOT and by the Large Area Telescope (LAT) on Fermi: NGC 1275, 3C 273, Cen A, and the Crab

Identificación de variedades autóctonas de vid en zonas transfronterizas del Duero

Castilla y León cuenta con una zona vitivinícola transfronteriza con el norte de Portugal, la DO Arribes, que linda con la región de Tras-os-Montes, en la que se ubica la Indicación de Procedencia Reglamentada PlanaltoMirandês. En ambas zonas vitivinícolas existe un elevado número de variedades minoritarias que cuentan con escasos individuos distribuidos demodo disperso en viñedos de reducidas dimensiones que son difíciles de localizar e identificar. Se ha llevado a cabo una minuciosa prospección en 2006, 2007 y 2008 en ambas zonas vitivinícolas y se ha logrado identificar un apreciable número de variedades combinando la descripción ampelográfica y el análisismolecular (SSR), así como establecer diferentes sinonimias usadas tanto en España como en Portugal

Simulación por elementos finitos de la articulación temporomandibular

En los últimos años, las patologías asociadas a la articulación temporomandibular (ATM) han cobrado una gran importancia en odontología y patología. Las disfunciones de esta articulación están relacionadas con la inestabilidad mecánica y el movimiento irregular de los componentes biomecánicos que la componen. Dentro de los diferentes elementos que forman esta articulación, es el disco articular la pieza clave dentro de la misma, ya que absorbe las tensiones durante el funcionamiento de la mandíbula, proporciona un adecuado contacto entre las superficies óseas y proporciona estabilidad a la articulación. En este trabajo se desarrollaron dos modelos de elemento finitos bidimensionales de la ATM, uno para una articulación sana y otro para una patológica afectada de un desplazamiento anterior del disco. En ambos modelos de elementos finitos se introdujeron diferentes modelos de comportamiento para simular de manera real el comportamiento del disco articular. Las simulaciones realizadas resultaron ser fieles al comportamiento biomecánico de la ATM real tanto sana como patológica, obteniéndose resultados cualitativos contrastados con la experiencia clínica. Por otro lado, se demostró la necesidad de introducir modelos de comportamiento complejos para simular de manera real el funcionamiento de esta articulación.Peer Reviewe

Identification and molecular biodiversity of autochthonous grapevine cultivars in the ‘Comarca del Bierzo’, León, Spain

A prospecting work at the ‘Comarca del Bierzo’ in Spain has been carried out in order to evaluate the existing biodiversity and detect the neglected and endangered minor grapevine cultivars of the zone. As a result, a total of 79 different accessions were collected and studied using STMS markers for preliminary variety identification, that was confirmed on the base of ampelographic observations. Several synonymies and homonymies were detected. A total of 33 different cultivars were identified. Comparison of the genotypes, allelic frequencies and allelic sizes are presented. Conservation of the endangered cultivars is highly recommended

Setting, Petrology and Geochemistry of the Volcanoclastic Complex of Orea (Guadalajara, Iberian Chain)

[Abstract] The volcanoclastic outcrop ofOrea (south margin of the Iberian Chain) reflects a pluriepisodic igneous activity, expressed in agglomerates and tuffs ofdacitic composition (with a calc-alkaline affinity) and Autunian-Thuringian age. The tuffs are the results' of a hydromagmatic activity, developed under a thin sheet of water (in a paludal environment). The structure of the magmatic outcrop results of the late-Hercynian extensional tectonics, equivalent to that observed in many other outcrops ofthe southeast border ofthe Iberian Chain. The setting characters and composition of the involved magmatic rock-types, suggest the presence of only one volcanic focus, as in other coetaneous half-grabens of this sector of the Iberian Chain