Coherent carrier dynamics in semiconductor superlattices

We investigate the coherent dynamics of carriers in semiconductor superlattices driven by ac-dc electric fields. We solve numerically the time-dependent effective-mass equation for the envelope function. We find that carriers undergo Rabi oscillations when the driving frequency is close to the separation between minibands.Comment: REVTEX (6 pages) and 3 figures (PostScript). Accepted in Physics Letters

Factor influencing trade show perfomance for spanish art and collecting sector

The aim of this research is to determine the direct relationship between the planning of exhibition participation. This will allow exhibitors understanding why they decide to go to a trade show and what the objectives are. The study focuses on the art and collecting sector, great international importance, because is relevant in the media and the benefits to the host city. Spanish art sector has a character-ristic disparity, its performance in relation to the number of exhibitors and visitors, generally, is the inverse of the exhibition sector. Finally, the results confirm that exhibitors pursue the relationships, and information search and strengthen their image. = Исследуется проблемы получения прибыли от организации и проведения торговых выставок. На примере сектора искусства и коллекционирования, имеющего большое международное экономическое значение для Испании, определяются факторы, которые в наибольшей степени необходимо учитывать при планировании таких мероприятий

Predicted Epitope Abundance Supports Vaccine-Induced Cytotoxic Protection Against SARS-CoV-2 Variants of Concern

The effect of emerging SARS-CoV-2 variants on vaccine efficacy is of critical importance. In this study, the potential impact of mutations that facilitate escape from the cytotoxic cellular immune response in these new virus variants for the 551 most abundant HLA class I alleles was analyzed. Computational prediction showed that most of these alleles, that cover >90% of the population, contain enough epitopes without escape mutations in the principal SARS-CoV-2 variants. These data suggest that the cytotoxic cellular immune protection elicited by vaccination is not greatly affected by emerging SARS-CoV-2 variants.This research was supported by grants from COV20_00679 (MPY 222-20), to MM, MPY 509/19 to AM-G, and MPY 388/18 to DL of “Acción Estratégica en Salud” from the ISCIII.S

Predicted impact of the viral mutational landscape on the cytotoxic response against SARS-CoV-2

The massive assessment of immune evasion due to viral mutations that increase COVID-19 susceptibility can be computationally facilitated. The adaptive cytotoxic T response is critical during primary infection and the generation of long-term protection. Here, potential HLA class I epitopes in the SARS-CoV-2 proteome were predicted for 2,915 human alleles of 71 families using the netMHCIpan EL algorithm. Allele families showed extreme epitopic differences, underscoring genetic variability of protective capacity between humans. Up to 1,222 epitopes were associated with any of the twelve supertypes, that is, allele clusters covering 90% population. Next, from all mutations identified in ~118,000 viral NCBI isolates, those causing significant epitope score reduction were considered epitope escape mutations. These mutations mainly involved non-conservative substitutions at the second and C-terminal position of the ligand core, or total ligand removal by large recurrent deletions. Escape mutations affected 47% of supertype epitopes, which in 21% of cases concerned isolates from two or more sub-continental areas. Some of these changes were coupled, but never surpassed 15% of evaded epitopes for the same supertype in the same isolate, except for B27. In contrast to most supertypes, eight allele families mostly contained alleles with few SARS-CoV-2 ligands. Isolates harboring cytotoxic escape mutations for these families co-existed geographically within sub-Saharan and Asian populations enriched in these alleles according to the Allele Frequency Net Database. Collectively, our findings indicate that escape mutation events have already occurred for half of HLA class I supertype epitopes. However, it is presently unlikely that, overall, it poses a threat to the global population. In contrast, single and double mutations for susceptible alleles may be associated with viral selective pressure and alarming local outbreaks. The integration of genomic, geographical and immunoinformatic information eases the surveillance of variants potentially affecting the global population, as well as minority subpopulations.This research was supported by Acción Estratégica en Salud from the ISCIII (https://www.isciii.es), grants MPY 380/18 (to MJM), 388/18 (to DL) and 509/19 (to AJM-G). AJM-G is the recipient of a Miguel Servet contract by the ISCIII. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.S

The effect of communication on the legitimacy and performance of organizations

Purpose – The aim of the investigation is to examine the effect of communication on the legitimacy and performance of organizations. The research framework was built based on Institutional Theory. Design/methodology/approach – The data were collected from 613 surveys of patients and health personnel of public hospitals in Madrid (Spain) and analyzed through partial least squares structural equation modeling (PLS-SEM). The questionnaires were anonymous. No identification data or biomedical data were requested. Findings – The results confirm the existence of a positive effect between communication and organizational legitimacy. They also indicate that the effect produced by communication on organizational performance is considerably greater than that produced by organizational legitimacy. The findings provide new knowledge on communication as an antecedent of organizational legitimacy. From a practical point of view, the research provides ideas on how hospital managers can improve their performance through communication management and organizational legitimacy. Originality/value – New evidence of the effects of communication on the legitimacy and performance of organizations is provided. The effect and the predictive relevance of legitimacy in relation on the performance of organizations are also identified

Tectonic evolution of Variscan Iberia: Gondwana–Laurussia

An integrated interpretation of the late Paleozoic structural and geochronological record of the Iberian Massif is presented and discussed under the perspective of a Gondwana-Laurussia collision giving way to the Variscan orogen. Compressional and extensional structures developed during the building of the Variscan orogenic crust of Iberia are linked together into major tectonic events operating at lithosphere scale. A review of the tectonometamorphic and magmatic evolution of the IberianMassif reveals backs and forths in the overall conver- gence between Gondwana and Laurussia during theamalgamation of Pangea in late Paleozoic times. Stages dom- inated by lithosphere compression are characterized by subduction, both oceanic and continental, development of magmatic arcs, (over- and under-) thrusting of continental lithosphere, and folding. Variscan convergence re- sulted in the eventual transference of a large allochthonous set of peri-Gondwanan terranes, the Iberian Allochthon, onto the Gondwana mainland. The Iberian Allochthon bears the imprint of previous interaction be- tween Gondwana and Laurussia, including their juxtaposition after the closure of the Rheic Ocean in Lower De- vonian times. Stages governed by lithosphere extension are featured by the opening of two short-lived oceanic basins that dissected previous Variscan orogenic crust, first in the Lower-Middle Devonian, following the closure of the Rheic Ocean, and then in the early Carboniferous, following the emplacement of the peri-Gondwanan allochthon. An additional, major intra-orogenic extensional event in the early-middle Carboniferous dismem- bered the Iberian Allochthon into individual thrust stacks separated by extensional faults and domes. Lateral tec- tonics played an important role through the Variscan orogenesis, especially during the creation of new tectonic blocks separated by intracontinental strike-slip shear zones in the late stages of continental convergence

MaLECoN: un nuevo material híbrido laminado fibra-metal para construcción naval.

Existe la necesidad perentoria de nuevos materiales para construcción naval que sean capaces de satisfacerlos requerimientos de diseño y fabricación de estructuras más ligeras, a la vez que resistentes, que permitan velocidades de desplazamiento más elevadas y menores consumos energéticos. El acero presenta una serie de limitaciones que dificultan la mejora continuada en la línea marcada para la fabricación de estructuras ligeras, resistentes y seguras. Los materiales compuestos son livianos y resistentes, pero los sistemas de fabricación son costosos y precisan de más mano de obra especializada; por otra parte, son muy sensibles al daño por impacto y pueden presentar problemas de degradación de sus propiedades mecánicas debido a la absorción de agua. Los materiales híbridos laminados fibra-metal combinan la elevada resistencia al impacto y la durabilidad, junto a la versatilidad en los procesos productivos propios de los materiales metálicos, con la resistencia y rigidez específicas en la dirección de las fibras, así como un buen comportamiento a fatiga, característica de los materiales compuestos. El material híbrido multicapas está formado por láminas metálicas alternando con otras de material compuesto y de adhesivo estructural, consiguiéndose prestaciones en servicio mejoradas. Este material ha sido patentado en la Oficina Española de Patentes y Marcas, junto con su procedimiento de fabricación. La extensión internacional de la patente a más de treinta países ha sido ya presentada y está siguiendo el procedimiento de concesión

Aurora A drives early signalling and vesicle dynamics during T-cell activation

Aurora A is a serine/threonine kinase that contributes to the progression of mitosis by inducing microtubule nucleation. Here we have identified an unexpected role for Aurora A kinase in antigen-driven T-cell activation. We find that Aurora A is phosphorylated at the immunological synapse (IS) during TCR-driven cell contact. Inhibition of Aurora A with pharmacological agents or genetic deletion in human or mouse T cells severely disrupts the dynamics of microtubules and CD3z-bearing vesicles at the IS. The absence of Aurora A activity also impairs the activation of early signalling molecules downstream of the TCR and the expression of IL-2, CD25 and CD69. Aurora A inhibition causes delocalized clustering of Lck at the IS and decreases phosphorylation levels of tyrosine kinase Lck, thus indicating Aurora A is required for maintaining Lck active. These findings implicate Aurora A in the propagation of the TCR activation signal.We thank S. Bartlett for English editing and critical reading of the manuscript, Dr A. Akhmanova for providing reagents, Maria Navarro for the her critical reading of the manuscript and scientific recommendations, Miguel Vicente-Manzanares for his critical reading of the manuscript, and Aitana Sanguino and Maria Jose Lopez for the technical support. We also thank the Confocal Microscopy \& Dynamic Imaging Unit (CNIC), Madrid, Spain. This study was supported by grants SAF2011-25834, SAF2014-55579-R and BIO2012-37926 from the Spanish Ministry of Economy and Competitiveness, INDISNET-S2011/BMD-2332 from the Comunidad de Madrid ERC-2011-AdG 294340-GENTRIS and ERC-2013-AdG 334763-NOVARIPP. Red Cardiovascular RD 12-0042-0056 from Instituto Salud Carlos III (ISCIII). The Centro Nacional de Investigaciones Cardiovasculares (CNIC, Spain) is supported by the Spanish Ministry of Science and Innovation, and the Pro-CNIC Foundation.S

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London