Directional shift current in mirror-symmetric BC2_2N

We present a theoretical study of the shift current in a noncentrosymmetric polytype of graphitic BC$_2$N. We find that the photoconductivity near the fundamental gap is strongly anisotropic due to the vanishing of particular tensor components not foretold by point-group symmetry arguments; this is a consequence of dipole selection rules imposed by mirror symmetry, which imply that the relative parities between valence and conduction bands are key for determining the directionality of the band-edge response. In addition, the band-edge photoconductivity turns out to be rather large, with the peak value occurring in an energy range suitable for optical manipulationComment: 7 pages, 4 figure

Analysis of RecA-independent recombination events between short direct repeats related to a genomic island and to a plasmid in Escherichia coli

RecA-independent recombination events between short direct repeats, leading to deletion of the intervening sequences, were found to occur in two genetic models in the Escherichia coli K12 background. The first model was a small E. coli genomic island which had been shown to be mobile in its strain of origin and, when cloned, also in the E. coli K12 context. However, it did not encode a site-specific recombinase as mobile genomic islands usually do. It was then deduced that the host cells should provide the recombination function. This latter was searched for by means of a PCR approach to detect the island excision in E. coli K12 mutants affected in a number of recombination functions, including the 16 E. coli K12 site-specific recombinases, the RecET system, and multiple proteins that participate in the RecA-dependent pathways of homologous recombination. None of these appeared to be involved in the island excision. The second model, analyzed in a RecA deficient context, was a plasmid construction containing a short direct repeat proceeding from Saccharomyces cerevisiae, which flanked the cat gene. The excision of this gene by recombination of the DNA repeats was confirmed by PCR and through the detection, recovery and characterization of the plasmid deleted form. In sum, we present new evidence on the occurrence of RecA-independent recombination events in E. coli K12. Although the mechanism underlying these processes is still unknown, their existence suggests that RecA-independent recombination may confer mobility to other genetic elements, thus contributing to genome plasticity

Geo-imagery management and statistical processing in a regional context using Open Data Cube

We propose a methodology to manage and process remote sensing and geo-imagery data for non-expert users. The proposed system provides automated data ingestion and manipulation capability for analytical data-driven purposes. In this paper, we describe the technological basis of the proposed method in addition to describing the tool architecture, the inherent data flow, and its operation in a specific use case to provide statistical summaries of Sentinel-2 regions of interest corresponding to the cultivation of polygonal areas located in the Basque Country (ES).Comment: 4 pages, 4 figures, Published in 2021 IEEE International Geoscience and Remote Sensing Symposium IGARS

Incongruence between clinicians’ assessment and self-reported functioning is related with psychopathology among patients diagnosed with gastrointestinal disorders

In a previous exploratory study we observed no relevant differences in psychopathology, personality, and functioning between inpatients diagnosed with gastrointestinal motor disorders (GMDs) or functional gastrointestinal disorders (FGDs) [1]. However, we observed higher levels of incongruence between clinician-assessed performance status and patients’ self-reported levels of functioning among patients diagnosed with FGDs. Likewise, research in other medical conditions has shown incongruences between self-reported and clinician-reported or objective measures [2]. Furthermore, in a study on chronic depression, the authors found that discrepancies between patients’ and physicians’ assessments of medical comorbidities were related to higher levels of depressive symptomatology [3]. In this line, the aim of this study was to explore whether the inconsistencies between clinician-assessed and patient self-reported levels of functioning could be related to psychopathology among patients admitted for evaluation of gastrointestinal motility

Arc-parallel vs back-arc extension in the Western Gibraltar arc : is the Gibraltar forearc still active?

Extremely tight arcs, framed within the Eurasia-Africa convergence region, developed during the Neogene on both sides of the western Mediterranean. A complex interplate deformation zone has been invoked to explain their structural trend-line patterns, the shortening directions and the development of back-arc basins. Updated structural and kinematic maps, combined with earthquake data covering the complete hinge zone of the western Gibraltar arc help us to explore the mode of strain partitioning from 25My ago to present. During the Miocene, the strain partitioning pattern showed arc-perpendicular shortening in the active orogenic wedge -assessed from the radial pattern of tectonic transport directions- accompained by subhorizontal stretching. Structures accommodating stretching fall into two categories on the basis of their space distribution and their relationships with the structural trend-line pattern: i) arc-parallel stretching structures in the external wedge (mainly normal faults and conjugate strike-slip faults); and ii) extensional faults developed in the hinterland zone in which transport directions are centripetal towards the Alborán back-arc basin. Pliocene to Recent deformational structures together with focal solutions from crustal earthquakes (n=167; 1.

N-Methylation of Amines with Methanol Catalyzed by Iridium(I) Complexes Bearing an N, O-Functionalized NHC Ligand

A set of neutral IrBr(L-2)-(kappa C-(t)BuImCH(2)PyCH(2)OMe)] and cationic Ir(L-2)-(kappa C, N-tBuImCH(2)PyCH(2)OMe)]PF6 (L-2 = cod, (CO)(2)) Ir(I) compounds featuring a flexible lutidine-derived polydentate ligand having NHC and - OMe as donor functions have been evaluated as catalyst precursors for the N-methylation of aniline using methanol both as a reducing agent and a C1 source. The carbonyl complexes are somewhat more active than the related diene compounds with the neutral compound IrBr(CO)(2)(kappa C-(t)BuImCH(2)PyCH(2)OMe)] being the more active. A range of aromatic primary amines, including heterocyclic amines, have been selectively transformed into the corresponding N-methylamino derivatives using this catalyst at a low catalyst loading (0.1 mol %) and substoichiometric amounts of Cs2CO3 (half equiv) as a base, in methanol at 423 K. For aliphatic primary amines, selective N, N-dimethylation was achieved under the same catalytic conditions. The unselective deprotonation of the methylene linkers in IrBr(CO)(2)(kappa C-(t)BuImCH(2)PyCH(2)OMe)] affords two isomeric neutral complexes featuring a coordinated dearomatized pyridine core, which were converted into Ir(OMe)(CO)(2)(kappa C-(t)BuImCH(2)PyCH(2)OMe)] upon addition of methanol. This compound undergoes thermal activation of a C-H bond of the tert-butyl group to give the cyclometalated iridium(I) complex Ir(CO)(2){kappa C-2, C-(-CH2Me2C-ImCH(2)PyCH(2)OMe)}] featuring a bidentate C, C-coordinated NHC ligand. Mechanistic investigations support a borrowing hydrogen mechanism proceeding through iridium(I) intermediates with the methoxo complex as the catalytic active species and the cyclometalated complex as the catalyst resting state. Deuterium labeling experiments have demonstrated that both species are in equilibrium under catalytic conditions, which is consistent with the exhibited catalytic activity of the cyclometalated complex

Propiedades de refracción de cónicas

Dados una recta △, un punto F que no pertenezca a △ y un número real e:(0 < E < 1), se define una elipse como el lugar geométrico de todos los puntos P del plano determinado por △ y F, tales que el cociente entre las distancias de P a F y de P a △ es constante, igual a E. Si se traza la recta y, tangente a la elipse en el punto P (que no sea uno de sus vértices), las rectas y y y se cortan en un punto N tal que los segmento PF y NF son perpendiculares. Esta sencilla propiedad permite interpretar a la constante E en términos de propiedadaes de refracción de la elipse. Se compara e ta demostración con la dada por R. Descartes en el Discurso III de "La Dióptrica" y se comentan algunas experiencias que permiten visualizar esta propiedad. Resultados similares pueden ser demostrados para las hipérbolas

An exploratory study comparing psychological profiles and its congruence with clinical performance among patients with functional or motility digestive disorders

Functional gastrointestinal disorders (FGDs) have been related with different psychological conditions. On the contrary the role of psychological factors within gastrointestinal motor disorders (GMDs) remains unclear. The objective of this study was to explore the differences and congruence with clinical performance of the psychological profile and subjective functionality among patients diagnosed with FGDs and GMDs. Using a double-blind design, fifty-six inpatients from a Gastroenterology Department were included in the study. No major differences were detected between the two groups. However, clinical performance was coherent with subjective physical functioning only among GMDs. These results may provide useful information for gastroenterologists dealing with patients’ complaints not consistent with their clinical profile

Microcin H47 System: An Escherichia coli Small Genomic Island with Novel Features

Genomic islands are DNA regions containing variable genetic information related to secondary metabolism. Frequently, they have the ability to excise from and integrate into replicons through site-specific recombination. Thus, they are usually flanked by short direct repeats that act as attachment sites, and contain genes for an integrase and an excisionase which carry out the genetic exchange. These mobility events would be at the basis of the horizontal transfer of genomic islands among bacteria