Self-similar transmission properties of aperiodic Cantor potentials in gapped graphene

We investigate the transmission properties of quasiperiodic or aperiodic structures based on graphene arranged according to the Cantor sequence. In particular, we have found self-similar behaviour in the transmission spectra, and most importantly, we have calculated the scalability of the spectra. To do this, we implement and propose scaling rules for each one of the fundamental parameters: generation number, height of the barriers and length of the system. With this in mind we have been able to reproduce the reference transmission spectrum, applying the appropriate scaling rule, by means of the scaled transmission spectrum. These scaling rules are valid for both normal and oblique incidence, and as far as we can see the basic ingredients to obtain self-similar characteristics are: relativistic Dirac electrons, a self-similar structure and the non-conservation of the pseudo-spin. This constitutes a reduction of the number of conditions needed to observe self-similarity in graphene-based structures, see D\'iaz-Guerrero et al. [D. S. D\'iaz-Guerrero, L. M. Gaggero-Sager, I. Rodr\'iguez-Vargas, and G. G. Naumis, arXiv:1503.03412v1, 2015]

SUMOylation regulates LKB1 localization and its oncogenic activity in liver cancer

BACKGROUND: Even though liver kinase B1 (LKB1) is usually described as a tumor suppressor in a wide variety of tissues, it has been shown that LKB1 aberrant expression is associated with bad prognosis in Hepatocellular Carcinoma (HCC). METHODS: Herein we have overexpressed LKB1 in human hepatoma cells and by using histidine pull-down assay we have investigated the role of the hypoxia-related post-translational modification of Small Ubiquitin-related Modifier (SUMO)ylation in the regulation of LKB1 oncogenic role. Molecular modelling between LKB1 and its interactors, involved in regulation of LKB1 nucleocytoplasmic shuttling and LKB1 activity, was performed. Finally, high affinity SUMO binding entities-based technology were used to validate our findings in a pre-clinical mouse model and in clinical HCC. FINDINGS: We found that in human hepatoma cells under hypoxic stress, LKB1 overexpression increases cell viability and aggressiveness in association with changes in LKB1 cellular localization. Moreover, by using site-directed mutagenesis, we have shown that LKB1 is SUMOylated by SUMO-2 at Lys178 hampering LKB1 nucleocytoplasmic shuttling and fueling hepatoma cell growth. Molecular modelling of SUMO modified LKB1 further confirmed steric impedance between SUMOylated LKB1 and the STe20-Related ADaptor cofactor (STRADα), involved in LKB1 export from the nucleus. Finally, we provide evidence that endogenous LKB1 is modified by SUMO in pre-clinical mouse models of HCC and clinical HCC, where LKB1 SUMOylation is higher in fast growing tumors. INTERPRETATION: Overall, SUMO-2 modification of LKB1 at Lys178 mediates LKB1 cellular localization and its oncogenic role in liver cancer. FUND: This work was supported by grants from NIH (US Department of Health and Human services)-R01AR001576-11A1 (J.M.M and M.L.M-C.), Gobierno Vasco-Departamento de Salud 2013111114 (to M.L.M.-C), ELKARTEK 2016, Departamento de Industria del Gobierno Vasco (to M.L.M.-C), MINECO: SAF2017-87301-R and SAF2014-52097-R integrado en el Plan Estatal de Investigación Cientifica y Técnica y Innovación 2013-2016 cofinanciado con Fondos FEDER (to M.L.M.-C and J.M.M., respectively), BFU2015-71017/BMC MINECO/FEDER, EU (to A.D.Q. and I.D.M.), BIOEF (Basque Foundation for Innovation and Health Research): EITB Maratoia BIO15/CA/014; Instituto de Salud Carlos III:PIE14/00031, integrado en el Plan Estatal de Investigación Cientifica y Técnica y Innovacion 2013-2016 cofinanciado con Fondos FEDER (to M.L.M.-C and J.M.M), Asociación Española contra el Cáncer (T.C.D, P·F-T and M.L.M-C), Daniel Alagille award from EASL (to T.C.D), Fundación Científica de la Asociación Española Contra el Cancer (AECC Scientific Foundation) Rare Tumor Calls 2017 (to M.L.M and M.A), La Caixa Foundation Program (to M.L.M), Programma di Ricerca Regione-Università 2007-2009 and 2011-2012, Regione Emilia-Romagna (to E.V.), Ramón Areces Foundation and the Andalusian Government (BIO-198) (A.D.Q. and I.D.M.), ayudas para apoyar grupos de investigación del sistema Universitario Vasco IT971-16 (P.A.), MINECO:SAF2015-64352-R (P.A.), Institut National du Cancer, FRANCE, INCa grant PLBIO16-251 (M.S.R.), MINECO - BFU2016-76872-R to (E.B.). Work produced with the support of a 2017 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation (M.V-R). Finally, Ciberehd_ISCIII_MINECO is funded by the Instituto de Salud Carlos III. We thank MINECO for the Severo Ochoa Excellence Accreditation to CIC bioGUNE (SEV-2016-0644). Funding sources had no involvement in study design; in the collection, analysis, and interpretation of data; in the writing of the report; and in the decision to submit the paper for publication

Inner and outer star forming regions over the disks of spiral galaxies. I. Sample characterization

Context. The knowledge of abundance distributions is central to understanding the formation and evolution of galaxies. Most of the relations employed for the derivation of gas abundances have so far been derived from observations of outer disk HII regions, despite the known differences between inner and outer regions. Aims. Using integral field spectroscopy (IFS) observations we aim to perform a systematic study and comparison of two inner and outer HII regions samples. The spatial resolution of the IFS, the number of objects and the homogeneity and coherence of the observations allow a complete characterization of the main observational properties and differences of the regions. Methods. We analyzed a sample of 725 inner HII regions and a sample of 671 outer HII regions, all of them detected and extracted from the observations of a sample of 263 nearby, isolated, spiral galaxies observed by the CALIFA survey. Results. We find that inner HII regions show smaller equivalent widths, greater extinction and luminosities, along with greater values of [NII]{\lambda}6583/H{\alpha} and [OII]{\lambda}3727/[OIII]{\lambda}5007 emission-line ratios, indicating higher metallicites and lower ionization parameters. Inner regions have also redder colors and higher photometric and ionizing masses, although Mion/Mphot is slighty higher for the outer regions. Conclusions. This work shows important observational differences between inner and outer HII regions in star forming galaxies not previously studied in detail. These differences indicate that inner regions have more evolved stellar populations and are in a later evolution state with respect to outer regions, which goes in line with the inside-out galaxy formation paradigm.Comment: 16 page

Optimización del coste energético en redes de riego a presión mediante su rehablitación

La gestión óptima de los recursos agua y energía en todos los sectores económicos, incluida la agricultura, tiene cada vez más importancia. El sector del riego, que ha experimentado una profunda transformación hacia sistemas de riego a presión, más eficientes en el uso del agua, pero con mayor demanda energética, también requiere medidas encaminadas al aumento de la eficiencia en la gestión de estos recursos. Este trabajo presenta una metodología fundamentada en la rehabilitación de redes de riego, mediante su rediseño, que determina el funcionamiento óptimo de la estación de bombeo que conlleva un coste de operación mínimo. La estrategia planteada se ha desarrollado en varios módulos. El primero de ellos consiste en la aplicación del algoritmo multiobjetivo NSGA-II, enlazado al simulador hidráulico EPANET, que minimiza el coste de rediseño de la red y de operación considerando un 100 % de simultaneidad de hidrantes. El segundo módulo contempla un análisis de la operación a la demanda de la red, generando múltiples patrones aleatorios de hidrantes abiertos/ cerrados. El tercer módulo analiza la operación a la demanda de la red en cada uno de los rediseños propuestos en el primer módulo y determina el funcionamiento de la estación de bombeo que minimiza el coste energético, teniendo en cuenta la tarifa eléctrica. La metodología propuesta se ha analizado en la CR El Villar (Sevilla) proporcionando un frente de Pareto que ofrece soluciones quasi óptimas con distinto grado de satisfacción de los objetivos propuestos. Mediante el posterior análisis financiero se ha determinado que la solución más viable a largo plazo, considerando una vida útil para la red de riego de 40 años y un interés del 5 %, conlleva un coste de inversión asociado al reemplazo de tuberías de 205.627 €, un coste de operación anual de 300.532 € y un coste total (inversión en el diseño, costes asociados a la renovación de las bombas y coste de operación) a lo largo de la vida útil de 6.019.447 €, lo que supondría un importante ahorro económico para la comunidad aplicando mayores volúmenes de agua para satisfacer las necesidades de los cultivos, en comparación con la situación actual en la que se aplica un riego deficitario debido a los elevados costes energéticos

Irrigation distribution networks' vulnerability to climate change

Climate change will lead to changed demands on ex isting irrigation systems. This paper presents a methodology for investigating the performance of irrigation networks under climate change, and applies this to an irrigation network in Cordoba , southern Spain. The methodology uses emission scenarios (A2 and B2) developed by the Interg overnmental Panel on Climate Change. A global climate model (HadCM3) is used with downscali ng to predict climate variables for 2050 and 2080 under the emission scenarios. Euro pean agricultural policy scenario s are used to predict future cropping patterns. Irrigation water requirements are th en estimated for various combinations of these climate and cropping pattern scenarios, and the perfo rmance of the irrigation network is evaluated in terms of the equity and adequacy of pressure at the outlets, using EPANET. The methodology was applied to the Fuente Palmera irrigation district, which supplies water on-demand for drip irrigation. The results show that climate change would have a major impact on network performance with the existing cropping pattern, but that expected chang es in cropping pattern would reduce this impact

New memory-based hybrid model for middle-term water demand forecasting in irrigated areas

The energy demand and their associated costs in pressurized irrigation networks together with water scarcity are currently causing serious challenges for irrigation district’s (ID) managers. Additionally, most of the new water distribution networks in IDs have been designed to be operated on-demand complexing ID managers the daily decision-making process. The knowledge of the water demand several days in advance would facilitate the management of the system and would help to optimize the water use and energy costs. For an efficient management and optimization of the water-energy nexus in IDs, longer term forecasting models are needed. In this work, a new hybrid model (called LSTMHybrid) combining Fuzzy Logic (FL), Genetic Algorithm (GA), LSTM encoder-decoder and dense or full connected neural networks (DNN) for the one-week forecasting of irrigation water demand at ID scale has been developed. LSTMHybrid was developed in Python and applied to a real ID. The optimal input variables for LSTMHydrid were mean temperature (°C), reference evapotranspiration (mm), solar radiation (MJ m−2) and irrigation water demand of the ID (m3) from 1 to 7 days prior to the first day of prediction. The optimal LSTMHybrid model selected consisted of 50 LSTM cells in the encoder submodel, 409 LSTM cells in the decoder submodel and three hidden layers in the DNN submodel with 31, 96 and 128 neurons in each hidden layer, respectively. Thus, LSTMHybrid had a total of 1.5 million parameters, obtaining a representativeness higher than 94 % and an accuracy around of 20 %

Histone chaperone activity of Arabidopsis thaliana NRP1 is blocked by cytochrome c

Higher-order plants and mammals use similar mechanisms to repair and tolerate oxidative DNA damage. Most studies on the DNA repair process have focused on yeast and mammals, in which histone chaperone-mediated nucleosome disassembly/reassembly is essential for DNA to be accessible to repair machinery. However, little is known about the specific role and modulation of histone chaperones in the context of DNA damage in plants. Here, the histone chaperone NRP1, which is closely related to human SET/TAF-I, was found to exhibit nucleosome assembly activity in vitro and to accumulate in the chromatin of Arabidopsis thaliana after DNA breaks. In addition, this work establishes that NRP1 binds to cytochrome c, thereby preventing the former from binding to histones. Since NRP1 interacts with cytochrome c at its earmuff domain, that is, its histone-binding domain, cytochrome c thus competes with core histones and hampers the activity of NRP1 as a histone chaperone. Altogether, the results obtained indicate that the underlying molecular mechanisms in nucleosome disassembly/reassembly are highly conserved throughout evolution, as inferred from the similar inhibition of plant NRP1 and human SET/TAF-I by cytochrome c during DNA damage response

Effect of water composition on catalytic reduction of nitrate

This work studies catalytic reduction of nitrate with bimetallic catalysts supported on γ-alumina (Pd-Sn/Al2O3 and Pd-In/Al2O3). Pd-Sn/Al2O3 yielded higher NO3− conversion and selectivity towards N2 than Pd-In/Al2O3 in synthetic water (deionized water with 100 mg/L NO3−). The Pd-Sn/Al2O3 catalyst showed highly stable behaviour, without signs of deactivation upon ten consecutive runs of 6 h each, where almost equal low selectivity to NH4+ (absence of NO2−) was maintained at high nearly constant nitrate conversion (≈ 90%). The presence of anions (Cl−, SO42− and HCO3−) in the reaction medium decreased NO3− conversion and the selectivity towards N2. Chloride showed a moderately negative effect at relatively low concentration. The effect of SO42− and HCO3− was more pronounced, being the second the most detrimental to the catalytic activity. The selectivity towards N2 was also negatively affected by the presence of those anions following the sequence HCO3− > SO42− > Cl−. However, the joint presence of Cl− or SO42− with HCO3− reduced the negative effect of the latter. The Pd-Sn/Al2O3 catalyst also showed high activity in NO3− reduction from drinking waters of weak mineralization, with a slightly increase of the selectivity towards NH4+ with respect to the obtained in deionized water with NO3− as the only anionThe authors wish to thank for the financial support the Spanish MINECO ( PID2019-108445RB-I00 ) and Comunidad de Madrid ( BIOTRES-CM , S2018/EMT-4344 ). I. Sanchis also thanks Comunidad de Madrid for award of a research grant ( PEJD-265 2017-PRE/AMB-4616