Tug-of-war between corrugation and binding energy: revealing the formation of multiple moiré patterns on a strongly interacting graphene-metal system

The formation of multidomain epitaxial graphene on Rh(111) under ultra-high vacuum (UHV) conditions has been characterized by scanning tunnelling microscopy (STM) measurements and density functional theory (DFT) calculations. At variance with the accepted view for strongly interacting graphene-metal systems, we clearly demonstrate the formation of different rotational domains leading to multiple moiré structures with a wide distribution of surface periodicities. Experiments reveal a correlation between the STM apparent corrugation and the lattice parameter of the moiré unit cell, with corrugations of just 30-40 pm for the smallest moirés. DFT calculations for a relevant selection of these moiré patterns show much larger height differences and a non-monotonic behaviour with the moiré size. Simulations based on non-equilibrium Green's function (NEGF) methods reproduce quantitatively the experimental trend and provide a detailed understanding of the interplay between electronic and geometric contributions in the STM contrast of graphene systems. Our study sheds light on the subtle energy balance among strain, corrugation and binding that drives the formation of the moiré patterns in all graphene/metal systems and suggests an explanation for the success of an effective model only based on the lattice mismatch. Although low values of the strain energy are a necessary condition, it is the ability of graphene to corrugate in order to maximize the areas of favourable graphene-metal interactions that finally selects the stable configurationsWe acknowledge financial support from Spanish grants MAT2013-41636-P, MAT2011-23627, MAT2011-26534, CSD2010-00024 (MINECO, Spain) and S2009/MAT-1467 (CAM, Spain). A.J.M.G. was supported by a Marie Curie action under the Seventh Framework Programme. P.P. was supported by the Ramón y Cajal Progra

Understanding the mechanisms of lung mechanical stress

Physical forces affect both the function and phenotype of cells in the lung. Bronchial, alveolar, and other parenchymal cells, as well as fibroblasts and macrophages, are normally subjected to a variety of passive and active mechanical forces associated with lung inflation and vascular perfusion as a result of the dynamic nature of lung function. These forces include changes in stress (force per unit area) or strain (any forced change in length in relation to the initial length) and shear stress (the stress component parallel to a given surface). The responses of cells to mechanical forces are the result of the cell's ability to sense and transduce these stimuli into intracellular signaling pathways able to communicate the information to its interior. This review will focus on the modulation of intracellular pathways by lung mechanical forces and the intercellular signaling. A better understanding of the mechanisms by which lung cells transduce physical forces into biochemical and biological signals is of key importance for identifying targets for the treatment and prevention of physical force-related disorders

Máster en Educación Matemática en Colombia

El grupo Didáctica de la Matemática: Pensamiento Numérico (FQM-193), del Plan Andaluz de Investigación, Desarrollo e Innovación (PAIDI) ha venido colaborando con la Universidad de los Andes de Bogotá, Colombia en la realización de un máster de profundización para profesores de matemáticas de secundaria en ejercicio. La primera versión de este máster se inició en enero de 2010. El programa busca contribuir al desarrollo del conocimiento didáctico de los profesores en formación, al guiarlos en la puesta en práctica de un ciclo del análisis didáctico e involucra esquemas metodológicos y de evaluación que se adaptan a su carácter semi virtual. En este trabajo se describirá el diseño curricular del programa y se presentarán unas primeras impresiones acerca de su desarrollo

The Arabidopsis thioredoxin TRXh5regulates the S-nitrosylation pattern of the TIRK receptor being both proteins essential in the modulation of defences to Tetranychus urticae

The interaction between plants and phytophagous arthropods encompasses a complex network of molecules, signals, and pathways to overcome defences generated by each interacting organism. Although most of the elements and modulators involved in this interplay are still unidentified, plant redox homeostasis and signalling are essential for the establishment of defence responses. Here, focusing on the response of Arabidopsis thaliana to the spider mite Tetranychus urticae, we demonstrate the involvement in plant defence of the thioredoxin TRXh5, a small redox protein whose expression is induced by mite infestation. TRXh5 is localized in the cell membrane system and cytoplasm and is associated with alterations in the content of reactive oxygen and nitrogen species. Protein S-nitrosylation signal in TRXh5 over-expression lines is decreased and alteration in TRXh5 level produces changes in the JA/SA hormonal crosstalk of infested plants. Moreover, TRXh5 interacts and likely regulates the redox state of an uncharacterized receptor-like kinase, named THIOREDOXIN INTERACTING RECEPTOR KINASE (TIRK), also induced by mite herbivory. Feeding bioassays performed withTRXh5 over-expression plants result in lower leaf damage and reduced egg accumulation after T. urticae infestation than in wild-type (WT) plants. In contrast, mites cause a more severe injury in trxh5 mutant lines where a greater number of eggs accumulates. Likewise, analysis of TIRK-gain and -loss-of-function lines demonstrate the defence role of this receptor in Arabidopsis against T. urticae. Altogether, our findings demonstrate the interaction between TRXh5 and TIRK and highlight the importance of TRXh5 and TIRK in the establishment of effective Arabidopsis defences against spider mite herbivory.Grants PID2020-115219RB-I00, RED2018-102397-T and RyC17MESFB funded by MCIN/AEI/10.13039/501100011033, as appropriate, by “ERDF A way of making Europe” and by the “European Union” supported this work. Grants, SIMQG-263-1HWZ8Q UPM-Banco Santander Universidades, RyC2017-21814 and PRE2018-083375 from MCIN/AEI supported AA, MES and IRD, respectively. The Spanish Ministry of Science and Innovation (MCIN), the State Research Agency (AEI) and the European Regional Development Fund (ERDF; grant MEC-PID2021-122280NB-I00) financed MCRP and LMS. The Government of Canada through the Ontario Research Fund (RE08-067) and the Natural Sciences and Engineering Research Council of Canada (NSERC, RGPIB-2018-04538) supported VG

Comparación entre dos tipos de gastrostomías quirúrgicas, abierta y laparoscópica, en nutrición enteral domiciliaria

Objetivo: Exponer las complicaciones de las gastrostomías quirúrgicas utilizadas como vía de soporte nutricional enteral domiciliario (SNED) y detectar si existen diferencias entre las dos técnicas usadas en nuestro medio: Cirugía abierta vs laparoscópica. Material y métodos: Estudio observacional descriptivo de carácter retrospectivo de las gastrostomías quirúrgicas realizadas entre los años 1994 y 2009 seguidas por nuestra unidad. Se han analizado las complicaciones detectadas en consulta durante el seguimiento de pacientes con SNED a través de gastrostomía quirúrgica realizada con técnica laparotómica abierta vs laparoscópica, valorando: fuga del contenido gástrico al exterior, irritación de la pared abdominal, presencia de exudado, presencia de exudado con cultivo positivo que requirió tratamiento antibiótico, quemadura o pérdida de sustancia de la zona periostomía, rotura de balón, úlcera de decúbito por la sonda y formación de granuloma. Resultados: Durante los años 1994-2009 se realizaron 57 gastrostomías quirúrgicas: 47 por técnica laparótomica (abierta) convencional y 10 por vía laparoscópica. La edad media de los pacientes fue de 57,51 ± 17,29 años. La causa más frecuente que motivó la realización de la gastrostomía quirúrgica fue el cáncer de esófago (38,6%) seguido de alteraciones neurológicas (26,3%) y tumores de cabeza y cuello (26,3%). El 97,9% de los pacientes a los que se realizó una gastrostomía quirúrgica abierta presentaron al menos una complicación, es decir que solo el 2,1% estuvieron libres de complicaciones; mientras que el 50% de los que se sometieron a una gastrostomía laparoscópica no tuvo ninguna. Las complicaciones más frecuentes fueron la presencia de fuga del contenido gástrico y la irritación de la pared abdominal que se presentaron en el 89,4% y 83% respectivamente de las gastrostomías laparotómicas frente a la aparición de solo el 30% de ambas complicaciones en las gastrostomías laparoscópicas siendo la diferencia estadísticamente significativa (p Aim: Exposing the complications of surgical gastrostomies used as way of home enteral nutritional support (HEN) and detecting the differences between the two techniques used in our environment: Open Surgery vs Laparoscopic Surgery. Material and methods: Retrospective descriptive observational study of the surgical gastrostomies performed between 1994 and 2009 followed up by our unit. Have been analyzed the complications detected in our practice during the follow-up of patients with HEN performed via open laparotomy vs. laparoscopic tecniques, assessing: leaks of gastric fluid to the exterior, abdominal wall irritation, presence of exudate, presence of exudate with positive culture that required antibiotical treatment, burning or loss of substance of the periostomic zone, breach of balloon, decubitus ulcer caused by the tube and formation of granuloma. Results: Between 1994 and 2009, 57 surgical gastrostomies were performed: 47 using the conventional laparotomic (open) tecnique and 10 laparoscopies. The average age of the patients was 57.51 ± 17.29 years old. The most common cause for the performance of surgical gastrostomy was esophageal cancer (38.6%) followed by neurologic alterations (26.3%) and head and neck tumors (26.3%). 97.9% of the patients who underwent to surgical gastrostomy presented at least one complication, meaning that only 2.1% were free of complications; meanwhile, 50% of the patients were laparoscopic gastrostomy was performed had none of these complications. The most common complications were the presence of leaks of gastric fluid and abdominal wall irritation that appeared on 89.4% and 83% respectively of the laparotomic gastrostomies versus the presence of only 30% of both complications in laparoscopic gastrostomies being the difference statistically significant (p < 0.01). Conclusions: After the introduction of the laparoscopic technique in the performance of surgical gastrostomies has been observed a decrease of the complications occured during the home enteral nutritional support related to surgical gastrostomies

Further Characterization of the Electrogenicity and pH Sensitivity of the Human Organic Anion-Transporting Polypeptides OATP1B1 and OATP1B3

Organic anion-transporting polypeptides (OATPs) are involved in the liver uptake of many endogenous and xenobiotic compounds, such as bile acids and drugs, respectively. Using Xenopus laevis oocytes and Chinese hamster ovary (CHO) cells expressing rat Oatp1a1, human OATP1B1, or OATP1B3, the sensitivity of these transporters to extracellular/intracellular pH (pHo/pHi) and changes in plasma membrane potential (ΔΨ) was investigated. In X. laevis oocytes, nonspecific plasma membrane permeability increased only at pHo below 4.5. Above this value, both using oocytes and CHO cells, extracellular acidification affected differently the specific transport of taurocholic acid (TCA) and estradiol 17β-d-glucuronide (E217βG) by Oatp1a1 (stimulation), OATP1B1 (inhibition), and OATP1B3 (stimulation). Changes in substrate uptake in the presence of valinomycin (K+-ionophore), carbonyl cyanide 3-chlorophenylhydrazone and nigericin (protonophores), and amiloride (Na+/H+-inhibitor) and cation replacement in the medium were studied with fluorescent probes for measuring substrate uptake (cholylglycyl amidofluorescein) and changes in pHi (SNARF-4F) and ΔΨ [DilC1(5)]. The results suggest that activity of these three carriers is sodium/potassium-independent and affected differently by changes in pHo and ΔΨ: Oatp1a1 was confirmed to be an electroneutral anion exchanger, whereas the function of both OATP1B1 and OATP1B3 was markedly affected by the magnitude of ΔΨ. Moreover, electrophysiological measurements revealed the existence of a net anion influx associated to OATP1B1/OATP1B3-mediated transport of TCA, E217βG, and estrone-3-sulfate. Furthermore, a leakage of Na+ through OATP1B1 and OATP1B3, which is not coupled to substrate transport, was found. In conclusion, these results suggest that OATP1B1 and OATP1B3 are electrogenic transporters whose activity may be strongly affected under circumstances of displacement of local pH

Solar Energy: Incentives to Promote PV in EU27

The growth in the use of renewable energies in the EU has been remarkable. Among these energies is PV. The average annual growth rate for the EU-27 countries in installed PV capacity in the period 2005-2012 was 41.2%. While the installed capacity of PV has reached almost 82 % of National Renewable Energy Action Plan (NREAP) targets for the EU-27 countries for 2020, it is still far from being used at its full potential. Over recent years, several measures have been adopted in the EU to enhance and promote PV. This paper undertakes a complete review of the state of PV power in Europe and the measures taken to date to promote it in EU-27. 25 countries have adopted measures to promote PV. The most widespread measure to promote PV use is Feed- in Tariffs. Tariffs are normally adjusted, in a decreasing manner, annually. Nevertheless, currently, seven countries have decided to accelerate this decrease rate in view of cost reduction of the installations and of higher efficiencies. The second instrument used to promote PV in the EU-27 countries is the concession of subsidies. Nevertheless, subsidies have the disadvantage of being closely linked to budgetary resources and therefore to budgetary constraints. In most EU countries, subsidies for renewable energy for PV are being lowered. Twelve EU-27 countries adopted tax measures. Low-interest loans and green certificate systems were only sparingly used

Decoherence and Initial Correlations in Quantum Brownian Motion

We analyze the evolution of a quantum Brownian particle starting from an initial state that contains correlations between this system and its environment. Using a path integral approach, we obtain a master equation for the reduced density matrix of the system finding relatively simple expressions for its time dependent coefficients. We examine the evolution of delocalized initial states (Schr\"odinger's cats) investigating the effectiveness of the decoherence process. Analytic results are obtained for an ohmic environment (Drude's model) at zero temperature.Comment: 15 pages, RevTex, 5 figures included. Submitted to Phys. Rev.

First observations of oblique ionospheric sounding chirp signal in Mexico

The results of the first experiment of oblique ionospheric sounding (OIS) chirp signal reception in Mexico are reported. Maximal and Lowest Observed Frequencies variations were studied under the quiet Space Weather conditions. The diurnal ionospheric variations by OIS signal confirm the results based on GNSS data in the Mexican region. The best HF radio propagation conditions along the considered path are during morning and daytime hours. The multi-hop propagation is frequent. The interlayer propagation modes are present at nighttime