534 research outputs found

    Nuevos registros de Hepáticas y Anthocerotófitas para Panamá

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    Twenty eight hepatics and eight hornwort species are reported as new to Panama. Data on their habitat, local and general distribution and are included. One species, Cololejeunea panamensis G. Dauphin & Pócs is described as new to science. A new combination, Megaceros canaliculatus (Pagán) Shaw & Renzaglia, corr. et emend. J. C. Vill. & Salazar Allen, is proposed. Eight further hepatic records from the literature have been added. This raises the total number of hepatics reported from Panama to 325 species in 100 genera and 28 families

    Storage Device Sizing for a Hybrid Railway Traction System by Means of Bicausal Bond Graphs

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    In this paper, the application of bicausal bond graphs for system design in electrical engineering is emphasized. In particular, it is shown how this approach is very useful for model inversion and parameter dimensioning. To illustrate these issues, a hybrid railway traction device is considered as a case study. The synthesis of a storage device (a supercapacitor) included in this system is then discussed

    Detection of Zak phases and topological invariants in a chiral quantum walk of twisted photons

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    Topological insulators are fascinating states of matter exhibiting protected edge states and robust quantized features in their bulk. Here, we propose and validate experimentally a method to detect topological properties in the bulk of one-dimensional chiral systems. We first introduce the mean chiral displacement, and we show that it rapidly approaches a multiple of the Zak phase in the long time limit. Then we measure the Zak phase in a photonic quantum walk, by direct observation of the mean chiral displacement in its bulk. Next, we measure the Zak phase in an alternative, inequivalent timeframe, and combine the two windings to characterize the full phase diagram of this Floquet system. Finally, we prove the robustness of the measure by introducing dynamical disorder in the system. This detection method is extremely general, as it can be applied to all one-dimensional platforms simulating static or Floquet chiral systems.Comment: 10 pages, 7 color figures (incl. appendices) Close to the published versio

    Identification of strong photometric activity in the components of LHS 1070

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    Activity in low-mass stars is an important ingredient in the evolution of such objects. Fundamental physical properties such as age, rotation, magnetic field are correlated with activity. Aims: We show that two components of the low-mass triple system LHS 1070 exhibit strong flaring activity. We identify the flaring components and obtained an improved astrometric solution for the LHS 1070 A/(B+C) system. Methods: Time-series CCD observations were used to monitor LHS 1070 in the B and I_C bands. H-band data were used to obtain accurate astrometry for the LHS 1070 A/(B+C) system. Results: We have found that two components of the triple system LHS 1070 exhibit photometric activity. We identified that components A and B are the flaring objects. We estimate the total energy, ~2.0 x 10^{33} ergs, and the magnetic field strength, ~5.5 kG, of the flare observed in LHS 1070 B. This event is the largest amplitude, \Delta B > 8.2 mag, ever observed in a flare star.Comment: 5 pages, 5 figures, accepted for publication in A&

    Comparison of Eight Methods for the Extraction of Bacillus atrophaeus Spore DNA from Eleven Common Interferents and a Common Swab

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    Eight DNA extraction products or methods (Applied Biosystems PrepFiler Forensic DNA Extraction Kit; Bio-Rad Instagene Only, Bio-Rad Instagene & Spin Column Purification; EpiCentre MasterPure DNA & RNA Kit; FujiFilm QuickGene Mini80; Idaho Technologies 1-2-3 Q-Flow Kit; MoBio UltraClean Microbial DNA Isolation Kit; Sigma Extract-N-Amp Plant and Seed Kit) were adapted to facilitate extraction of DNA under BSL3 containment conditions. DNA was extracted from 12 common interferents or sample types, spiked with spores of Bacillus atropheaus. Resulting extracts were tested by real-time PCR. No one method was the best, in terms of DNA extraction, across all sample types. Statistical analysis indicated that the PrepFiler method was the best method from six dry powders (baking, biological washing, milk, plain flour, filler and talcum) and one solid (Underarm deodorant), the UltraClean method was the best from four liquids (aftershave, cola, nutrient broth, vinegar), and the MasterPure method was the best from the swab sample type. The best overall method, in terms of DNA extraction, across all sample types evaluated was the UltraClean method

    Observation of the topological Anderson insulator in disordered atomic wires

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    Topology and disorder have deep connections and a rich combined influence on quantum transport. In order to probe these connections, we synthesized one-dimensional chiral symmetric wires with controllable disorder via spectroscopic Hamiltonian engineering, based on the laser-driven coupling of discrete momentum states of ultracold atoms. We characterize the system's topology through measurement of the mean chiral displacement of the bulk density extracted from quench dynamics. We find evidence for the topological Anderson insulator phase, in which the band structure of an otherwise trivial wire is driven topological by the presence of added disorder. In addition, we observed the robustness of topological wires to weak disorder and measured the transition to a trivial phase in the presence of strong disorder. Atomic interactions in this quantum simulation platform will enable future realizations of strongly interacting topological fluids.Comment: 6 pages, 3 figures; 9 pages of supplementary material

    Matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry for fast and accurate identification of clinically relevant Aspergillus species

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    AbstractNew Aspergillus species have recently been described with the use of multilocus sequencing in refractory cases of invasive aspergillosis. The classical phenotypic identification methods routinely used in clinical laboratories failed to identify them adequately. Some of these Aspergillus species have specific patterns of susceptibility to antifungal agents, and misidentification may lead to inappropriate therapy. We developed a matrix‐assisted laser desorption ionization time‐of‐flight (MALDI‐TOF) mass spectrometry (MS)‐based strategy to adequately identify Aspergillus species to the species level. A database including the reference spectra of 28 clinically relevant species from seven Aspergillus sections (five common and 23 unusual species) was engineered. The profiles of young and mature colonies were analysed for each reference strain, and species‐specific spectral fingerprints were identified. The performance of the database was then tested on 124 clinical and 16 environmental isolates previously characterized by partial sequencing of the β‐tubulin and calmodulin genes. One hundred and thirty‐eight isolates of 140 (98.6%) were correctly identified. Two atypical isolates could not be identified, but no isolate was misidentified (specificity: 100%). The database, including species‐specific spectral fingerprints of young and mature colonies of the reference strains, allowed identification regardless of the maturity of the clinical isolate. These results indicate that MALDI‐TOF MS is a powerful tool for rapid and accurate identification of both common and unusual species of Aspergillus. It can give better results than morphological identification in clinical laboratories

    Патопсихологические особенности и закономерности развития органических психических расстройств при болезни Паркинсона

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    Проанализированы особенности эмоционально−потребностной сферы, выраженность личностных особенностей, типы отношения к болезни у пациентов с болезнью Паркинсона (БП) и психическими расстройствами. Выявлены патопсихологические факторы формирования органического депрессивного расстройства (F06.36), органического тревожного расстройства (F06.4), органического эмоционально−лабильного расстройства (F06.6), описаны механизмы их патогенеза. Относительно деменции (F02.3) у больных БП единого патопсихологического механизма ее формирования не обнаружено, основная роль в ее патогенезе принадлежит органическому поражению головного мозга.Проаналізовано особливості емоційно−потребової сфери, виразність особистісних особливостей, типи ставлення до хвороби у пацієнтів із хворобою Паркінсона (ХП) та психічними розладами. Виявлено патопсихологічні фактори формування органічного депресивного розладу (F06.36), органічного тривожного розладу (F06.4), органічного емоційно−лабільного розладу (F06.6), описано механізми їх патогенезу. Щодо деменції (F02.3) у хворих на ХП єдиного патопсихологічного механізму її формування не виявлено, основна роль в її патогенезі належить органічному ураженню головного мозку.The peculiarities of emotion−need sphere, degree of personality peculiarities, types of attitude to the disease were analyzed in patients with Parkinson's disease (PD) and mental disorders. Pathopsychological factors of forming organic depressive disorder (F06.36), organic anxiety disorder (F06.4), organic emotional−labile disorder (F06.6) were revealed. The mechanisms of their pathogenesis were described. As for dementia (F02.3), uniform pathopsychological mechanism of its formation was not revealed in patients with PD. Main role in its pathogenesis is played by organic brain lesions

    Symphony on strong field approximation

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    This paper has been prepared by the Symphony collaboration (University of Warsaw, Uniwersytet Jagiellonski, DESY/CNR and ICFO) on the occasion of the 25th anniversary of the 'simple man's models' which underlie most of the phenomena that occur when intense ultrashort laser pulses interact with matter. The phenomena in question include high-harmonic generation (HHG), above-threshold ionization (ATI), and non-sequential multielectron ionization (NSMI). 'Simple man's models' provide both an intuitive basis for understanding the numerical solutions of the time-dependent Schrodinger equation and the motivation for the powerful analytic approximations generally known as the strong field approximation (SFA). In this paper we first review the SFA in the form developed by us in the last 25 years. In this approach the SFA is a method to solve the TDSE, in which the non-perturbative interactions are described by including continuum-continuum interactions in a systematic perturbation-like theory. In this review we focus on recent applications of the SFA to HHG, ATI and NSMI from multi-electron atoms and from multi-atom molecules. The main novel part of the presented theory concerns generalizations of the SFA to: (i) time-dependent treatment of two-electron atoms, allowing for studies of an interplay between electron impact ionization and resonant excitation with subsequent ionization; (ii) time-dependent treatment in the single active electron approximation of 'large' molecules and targets which are themselves undergoing dynamics during the HHG or ATI processes. In particular, we formulate the general expressions for the case of arbitrary molecules, combining input from quantum chemistry and quantum dynamics. We formulate also theory of time-dependent separable molecular potentials to model analytically the dynamics of realistic electronic wave packets for molecules in strong laser fields. We dedicate this work to the memory of Bertrand Carre, who passed away in March 2018 at the age of 60

    Efficient algorithm to compute the Berry conductivity

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    We propose and construct a numerical algorithm to calculate the Berry conductivityin topological band insulators. The method is applicable to cold atomsystems as well as solid state setups, both for the insulating case where the Fermienergy lies in the gap between two bulk bands as well as in the metallic regime.This method interpolates smoothly between both regimes. The algorithm isgauge-invariant by construction, efficient, and yields the Berry conductivity withknown and controllable statistical error bars. We apply the algorithm to severalparadigmatic models in the field of topological insulators, including Haldaneʼsmodel on the honeycomb lattice, the multi-band Hofstadter model, and the BHZmodel, which describes the 2D spin Hall effect observed in CdTe/HgTe/CdTequantum well heterostructures
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