Confinement of electrons in layered metals

We analyze the out of plane hopping in models of layered systems where the in--plane properties deviate from Landau's theory of a Fermi liquid. We show that the hopping term acquires a non trivial energy dependence, due to the coupling to in plane excitations, and can be either relevant or irrelevant at low energies or temperatures. The latter is always the case if the Fermi level lies close to a saddle point in the dispersion relation.Comment: 4 pages, 1 eps figur

El constructo Valor Social Subjetivo de la Educación: validación cruzada entre profesorado de escuela y universidad

La Educación posee un valor social evidente que puede presentarse mediante indicadores de evaluación socio-educativos. Si bien la relación entre contexto escolar y rendimiento es evidente en diversos países, esta relación va perdiendo consistencia en los últimos años; ya que aparecen sectores estudiantiles que superan las predicciones académicas esperadas. Para ello, se estudia el Valor Social Subjetivo de la Educación en función de dos grupos docentes -escuela y universidad-. La metodología es complementaria a través de comités de expertos/as y validación cruzada de constructo. Se realizan análisis sobre dos escalas -relevancia y susceptibilidad de cambio- y entre dos muestras diferenciadas para comprobar el consenso inter-subjetivo. Los datos muestran un acuerdo estadísticamente significativo en todas las dimensiones, sin embargo, se observan discrepancias dependiendo de la etapa escolar. Finalmente, se propone un constructo validado a través de cuatro dimensiones y trece indicadores de evaluación

Una aproximación al valor social subjetivo de la educación en Iberoamérica. Evidencias de validez entre Argentina, España y República Dominicana

Se presenta un estudio de validación sobre el valor social subjetivo de la educación entre Argentina, España y República Dominicana. Se trata de una investigación de metodología mixta desarrollada con 251 docentes a través de encuesta online y grupos focales. Se analiza y valora el construc-to teórico de acuerdo a su relevancia y susceptibilidad de cambio a través de una validación cruzada entre tres contextos. Los resultados muestran un acuerdo estadísticamente significativo en cada país, además de que aparecen diferencias significativas entre ellos. El concepto trabajado es fundamental a nivel internacional, ya que supone una reflexión hacia la potencialidad de la propia educación. El estudio constituye un avance en la superación de la asociación entre el nivel socio-económico y cultural familiar y el rendimiento académico: es posible que existan aspectos sub-jetivos, tales como se indican en relación al constructo, que pueden afec-tar de manera diferencial al proceso educativo dependiendo del contexto. This is a validation study on the subjective social value of education between Argentina, Spain and the Dominican Republic, using a mixed research methodology developed with 251 teachers, using an online survey and focus groups. The theoretical construct is analyzed and assessed in accordance with its relevance and susceptibility to change through cross-validation between three contexts. The results show a statistically significant agreement in each country, as well as significant differences between them. The concept in question is essential internationally, since it reflects on the potential of education itself. The study constitutes a step forward, moving beyond making associations between families' socioeconomic and cultural level and academic performance; subjective aspects can also exist, as indicated in relation to the construct, which can differentially affect the education process depending on the context

Propiedades métricas de un instrumento para evaluar el Valor Social Subjetivo de la Educación: escala SECS-EVALNEC VSE-Estudiantes-Secundaria

El estudio analiza los resultados de la aplicación de un instrumento que pretende medir el Valor Social Subjetivo de la Educación. Trabajando con un grupo de 341 estudiantes de Educación Secundaria Obligatoria en España, se exponen las propiedades métricas del instr umento desde una metodología de Teoría Clásica de los Tests y Teoría de Respuesta al Ítem para comprobar su fiabilidad y bondad de ajuste. Después de comprobar la dimensionalidad de la escala y el funcionamiento de los reactivos, los datos muestr an que todos se ajustan adecuadamente al modelo de referencia. A partir de ello, presentamos una propuesta de escala SECS - EVALNEC VSE - Estudiantes - Secundaria unidimensional conformada por 20 ítems con una fiabilidad global de .73. Los resultados del estudio demuestran niveles aceptables en ambas perspectivas, aportando un primer indicio como evidencia de validación del instrumento de evaluación. The study analyzes the results of the administration of an instrument intended to measure the subjective social value of education. By working with a group of 341 students of compulsory secondary education in Spain, the study presents the metric properties of the instrument based on a classical test theory and item response theory methodology to verify its reliability and goodness - of - fit. After the dimensionality of the scale and the functioning of items were verified , all items displayed an appropriate fit to the benchmark model. On this basis, a proposal is put forward for a unidimensional SECS - EVALNEC SVE - Students - Secondary Education scale made up of 20 items with a global reliability of .73. The results of the stud y show acceptable levels in both perspectives, providing initial evidence to validate this assessment instrument

Interlayer hopping properties of electrons in layered metals

A formalism is proposed to study the electron tunneling between extended states, based on the spin-boson Hamiltonian previously used in two-level systems. It is applied to analyze the out--of--plane tunneling in layered metals considering different models. By studying the effects of in--plane interactions on the interlayer tunneling of electrons near the Fermi level, we establish the relation between departure from Fermi liquid behavior driven by electron correlations inside the layer and the out of plane coherence. Response functions, directly comparable with experimental data are obtained

Effectiveness and persistence of golimumab as a second biological drug in patients with spondyloarthritis

This observational, longitudinal retrospective, noncomparative study was designed to assess the persistence and effectiveness of golimumab as a second anti-tumor necrosis factor (TNF) drug in patients with spondyloarthritis requiring discontinuation from a first anti-TNF drug.Data were collected retrospectively for all patients with axial spondyloarthritis or psoriatic arthritis from 20 rheumatology clinics in Spain who started golimumab as a second anti-TNF drug between January 2013 and December 2015. Golimumab persistence was assessed with Kaplan-Meier survival analysis, and associated factors were assessed with Cox regression analysis.210 patients started golimumab as a second anti-TNF drug: 131 with axial spondyloarthritis and 79 with psoriatic arthritis. In axial spondyloarthritis patients, the mean (standard deviation) Bath Ankylosing Spondylitis Disease Activity Index score at baseline was 5.5 (2.1), decreasing to 3.9 (2.0) at month 3 and 3.5 (2.0) at year 1, and remaining stable thereafter. In psoriatic arthritis patients, mean (standard deviation) baseline Disease Activity Score was 4.0 (1.3), reducing to 2.5 (1.2) at month 3 and to 2.2 (1.3) at year 1. Corresponding improvements were recorded from baseline in C-reactive protein levels and erythrocyte sedimentation rates. The probability of persistence of treatment with golimumab was 80% at year 1, 70% at year 2 and 65% at years 3 and year 4, and was similar in those who had stopped the first anti-TNF due to loss of efficacy or other reasons. Cox regression analysis showed that the probability of survival with golimumab was higher in patients with higher erythrocyte sedimentation rate, in patients with axial spondyloarthritis than with psoriatic arthritis, and in those who had discontinued adalimumab as first anti-TNF. Seventy-two patients (34.3%) discontinued golimumab during follow-up, 50 of them due to lack of efficacy.In patients with spondyloarthritis requiring discontinuation from a first anti-TNF drug, treatment with golimumab was effective and showed a high probability of persistence up to 4 years of treatment

Instrumento para Evaluar la Cohesión Social en Universidades Mexicanas: Resultados de la Validación Cultural UNIVECS-MX

El objetivo de este artículo es ofrecer un instrumento para evaluar la cohesión social en universidades mexicanas. A partir del modelo de evaluación UNIVECS validado en el contexto español, se realiza una adaptación y validación cultural en México; desarrollando un juicio de expertos con nueve profesionales del área de Antropología, Lingüística, Pedagogía, Psicología y Sociología, un jueceo con 51 docentes en educación superior, cuatro grupos de validación de reactivos entre tres universidades con 42 docentes, y un grupo de validación con diez estudiantes universitarios. Todo ello, en función de cuatro criterios de valoración cuantitativa y cualitativa: pertinencia, claridad, factibilidad y ausencia de sesgos lingüísticos, culturales, organizacionales y de género. A partir de los resultados y propuestas de mejora se obtiene un paquete de reactivos validados en torno a ocho dimensiones de análisis de la cohesión social en educación superior: Sostenibilidad, Bienestar Social, Inclusión, Autonomía Personal, Sentido de Pertenencia, Confianza, Movilidad Social y Responsabilidad Social. Los resultados posibilitan y concluyen un instrumento de evaluación pertinente, claro, factible y libre de sesgos. UNIVECS-MX se ofrece a las instituciones mexicanas para poder identificar en sus licenciaturas la cohesión social y poder realizar diagnósticos institucionales de cada dimensión propuesta, así como seguir realizando investigaciones socio-educativas

Reconstrucción de la vegetación asociada al depósito tobáceo fluvial holoceno del nogal de el batán, las parras del martín, cordillera ibérica

Development of Quaternary fluvial tufa buildings are often associated with warm and humid phases and are commonly used as climate indicators. El Nogal de El Batán Holocene fluvial tufa buildup, located in Las Parras River valley (Iberian Range, NE Spain), is investigated, following radiocarbon dating, stratigraphic description and palynological analysis. The studied deposit, 8.2 m-thick, is formed of gravels, phytoclast rudstones, calcite- coated stem boundstones and fine carbonate deposits (sands, silts and marls) with peaty horizons and carbonaceous debris. It has been dated within the upper early Holocene (ca. 8400 cal BP) and correlated with the environmental changes reconstructed for the region, identifying at least, three main phases. Pollen results highlight the existence of a conifer landscape, mainy dominated by Pinus nigra/sylvestris type and Juniperus, and locally dense riparian woodland with Corylus, Alnus, Salix, Populus, Celtis, Fraxinus, Tamarix and Rosaceae. Deciduous and evergreen oaks were the main spread regional forests accompanied by many warm-loving taxa like Pistacia, Rhamnus, Arbutus and Olea during the middle Holocene (ca. 8000-5000 cal BP). The transition towards the late Holocene (ca. 4300 cal BP) is evidenced by the rise of herbs and ruderal taxa, and especially the presence of coprophilous fungi, which are linked to the spread of agricultural and grazing practices along the river valley.El desarrollo de edificios tobáceos de origen fluvial se asocia a menudo con fases cálidas y húmedas cuaternarias y son comúnmente empleados como indicadores climáticos. En el presente trabajo se estudia el depósito tobáceo fluvial Holoceno del Nogal de El Batán, situado en el valle del río Las Parras (Cordillera Ibérica, NE España), bajo una perspectiva cronológica, estratigráfica y palinológica. La acumulación tobácea de 8,2 m de espesor, intercala gravas, facies de rudstones de fitoclastos, boundstones de tallos, limos y arenas de composición carbonatada, además de margas, lime mud y niveles turbosos. La acumulación tobácea se emplaza en el Holoceno temprano final (ca. 8400 cal BP) y se correlaciona con los cambios ambientales ocurridos en la región, identificando tres fases principales. Los análisis polínicos señalan un paisaje dominado por coníferas en la base de la secuencia, esencialmente con Pinus nigra/sylvestris tipo y Juniperus, mientras que localmente se desarrolla un bosque ripario donde destacan Corylus, Alnus, Salix, Populus, Celtis, Fraxinus, Tamarix y Rosaceae. En el Holoceno medio (ca. 8000-5000 cal BP) se produce la máxima expansión de las quercíneas, junto con taxones termófilos como Pistacia, Rhamnus, Arbutus y Olea. El incremento de taxones herbáceos y ruderales, y en especial la aparición de esporas coprófilas, marca la expansión agro-pastoril a lo largo del valle fluvial durante el Holoceno tardío (ca. 4300 cal BP)

Plant catalases as NO and H2S targets

Catalase is a powerful antioxidant metalloenzyme located in peroxisomes which also plays a central role in signaling processes under physiological and adverse situations. Whereas animals contain a single catalase gene, in plants this enzyme is encoded by a multigene family providing multiple isoenzymes whose number varies depending on the species, and their expression is regulated according to their tissue/organ distribution and the environmental conditions. This enzyme can be modulated by reactive oxygen and nitrogen species (ROS/RNS) as well as by hydrogen sulfide (H2S). Catalase is the major protein undergoing Tyr-nitration [post-translational modification (PTM) promoted by RNS] during fruit ripening, but the enzyme from diverse sources is also susceptible to undergo other activity-modifying PTMs. Data on S-nitrosation and persulfidation of catalase from different plant origins are given and compared here with results from obese children where S-nitrosation of catalase occurs. The cysteine residues prone to be S-nitrosated in catalase from plants and from bovine liver have been identified. These evidences assign to peroxisomes a crucial statement in the signaling crossroads among relevant molecules (NO and H2S), since catalase is allocated in these organelles. This review depicts a scenario where the regulation of catalase through PTMs, especially S-nitrosation and persulfidation, is highlighted

Long-term follow-up of prophylactic mesh reinforcement after emergency laparotomy. A retrospective controlled study

Prevention of incisional hernias with a prophylactic mesh in emergency surgery is controversial. The present study aimed to analyze the long-term results of prophylactic mesh used for preventing incisional hernia after emergency midline laparotomies. This study was a registered (NCT04578561) retrospective analysis of patients who underwent an emergency midline laparotomy between January 2009 and July 2010 with a follow-up period of longer than 2 years. Long-term outcomes and risk factors for the development of incisional hernias between patients who received a prophylactic reinforcement mesh (Group M) and suture (Group S) were compared. From an initial 266 emergency midline laparotomies, 187 patients were included. The median follow-up time was 64.4 months (SD 35). Both groups had similar characteristics, except for a higher rate of previous operations (62 vs. 43.2%; P = 0.01) and operation due to a revision laparotomy (32.5 vs.13%; P = 0.02) in the M group. During follow-up, 29.9% of patients developed an incisional hernia (Group S 36.6% vs. Group M 14.3%; P = 0.002). Chronic mesh infections were diagnosed in 2 patients, but no mesh explants were needed, and no patient in the M group developed chronic pain. Long-term risk factors for incisional hernia were as follows: smoking (HR = 2.47; 95% CI 1.318-4.624; P = 0.05), contaminated surgery (HR = 2.98; 95% CI 1.142-7.8; P = 0.02), surgical site infection (SSI; HR = 3.83; 95% CI 1.86-7.86; P = 0.001), and no use of prophylactic mesh (HR = 5.09; 95% CI 2.1-12.2; P = 0.001). Incidence of incisional hernias after emergency midline laparotomies is high and increases with time. High-risk patients, contaminated surgery, and surgical site infection (SSI) benefit from mesh reinforcement. Prophylactic mesh use is safe and feasible in emergencies with a low long-term complication rate. Trial registration: NCT04578561