Magnetic Structure of Hydrogen Induced Defects on Graphene

Using density functional theory (DFT), Hartree-Fock, exact diagonalization, and numerical renormalization group methods we study the electronic structure of diluted hydrogen atoms chemisorbed on graphene. A comparison between DFT and Hartree-Fock calculations allows us to identify the main characteristics of the magnetic structure of the defect. We use this information to formulate an Anderson-Hubbard model that captures the main physical ingredients of the system, while still allowing a rigorous treatment of the electronic correlations. We find that the large hydrogen-carbon hybridization puts the structure of the defect half-way between the one corresponding to an adatom weakly coupled to pristine graphene and a carbon vacancy. The impurity's magnetic moment leaks into the graphene layer where the electronic correlations on the C atoms play an important role in stabilizing the magnetic solution. Finally, we discuss the implications for the Kondo effect.Comment: 10 pages, 10 fig

Technological development for improving long-distance communication between handicapped people

Objetivo Proporcionar a la población en general, especialmente a las personas en situación de discapacidad, un dispositivo de comunicación que mediante: 1) Un proceso inteligente; 2) Un sistema codificación/decodificación adaptativo y 3) Unas interfaces accesibles, les permita fomentar unas adecuadas competencias comunicativas, como mecanismo de inclusión social, aportándoles las posibilidades de satisfacer adecuadamente algunas necesidades humanas fundamentales. Métodos La investigación se realizó con base en tres enfoques, cada uno predecesor del siguiente, inicialmente el exploratorio, con el que se buscó determinar el estado del arte de la investigación, luego el descriptivo, que buscó profundizar en la tecnología desarrollada o aplicada a la inclusión social de las personas con discapacidad, y finalmente uno de tipo cuasi-experimental, con el que se desarrolló un producto tecnológico que fue validado con personas de distintas discapacidades, realizando los ajustes y adaptaciones necesarias. Resultados El principal resultado de este proyecto fue la creación de un dispositivo de comunicación que incrementa el desarrollo de las competencias comunicativas en las personas con discapacidad motora, ciego, sordo postlingual bilingüe y sordociego postlingual, entre ellas y/o cualquier otra persona sin discapacidad, sin que esta última deba tener también el dispositivo diseñado y construido en esta investigación. Conclusiones Se diseñó, implementó y validó el desarrollo de un dispositivo tecnológico denominado como prototipo SCDA, basado en funciones electrónicas que le permiten al usuario el desarrollo de algunas necesidades humanas fundamentales, basadas en el derecho inherente que todo ser humano sin importar su condición física, mental o económica tiene de comunicarse

Electrical Control of the Chemical Bonding of Fluorine on Graphene

We study the electronic structure of diluted F atoms chemisorbed on graphene using density functional theory calculations. We show that the nature of the chemical bonding of a F atom adsorbed on top of a C atom in graphene strongly depends on carrier doping. In neutral samples the F impurities induce a sp^3-like bonding of the C atom below, generating a local distortion of the hexagonal lattice. As the graphene is electron-doped, the C atom retracts back to the graphene plane and for high doping (10^14 cm^-2) its electronic structure corresponds to a nearly pure sp^2 configuration. We interpret this sp^3-sp^2 doping-induced crossover in terms of a simple tight binding model and discuss the physical consequences of this change.Comment: 4 pages, 4 figures. Accepted in Phys. Rev. B. Rapid Com

PROTOTIPO DE TECNOLOGÍA EN ASISTENCIA PARA LA ENSEÑANZA DEL BRAILLE

Con el diseño y fabricación del dispositivo denominado sistema electrónico mecánico para el aprendizaje la lectoescritura del Braille (SEMLEB), junto con la aplicación de una metodología basada en acompañamiento de un tutor, se buscó determinar y analizar los factores que facilitaran el proceso de aprendizaje de la lectoescritura del sistema Braille para niños ciegos en etapa escolar y sus repercusiones en el aprendizaje del castellano para identificar las letras del alfabeto, los fonemas, las sílabas, y algunas palabras y frases de corta longitud

Carbon remineralization by small mesopelagic and bathypelagic Stomiiforms in the Northeast Atlantic Ocean

The organic carbon resulting from photosynthesis in the upper ocean is transferred downward through the passive sinking of organic particles, physical mixing of particulate and dissolved organic carbon as well as active flux transported by zooplanktonic and micronektonic migrants. Several meso- and bathypelagic organisms feed in shallower layers during the nighttime and respire, defecate, excrete and die at depth. Recent studies suggest that migrant micronekton transport similar amounts of carbon to migrant zooplankton. However, there is scarce information about biomass and carbon flux by non-migratory species in the mesopelagic and bathypelagic zones. The non-migratory bristlemouth fishes (Cyclothone spp.) and partial migrator (A. hemigymnus) remineralise organic carbon at depth, and knowledge about this process by this fauna is lacking despite them having been referred to as the most abundant vertebrates on Earth. Here we show the vertical distribution of biomass and respiration of non-migratory mesopelagic fishes, during day and night, using the enzymatic activity of the electron transfer system (ETS) as a proxy for respiration rates. The study is focused on five Cyclothone species (C. braueri, C. pseudopallida, C. pallida, C. livida and C. microdon) and Argyropelecus hemigymnus. The samples were taken on a transect from the oceanic upwelling off Northwest Africa (20° N, 20° W) to the south of Iceland (60° N, 20° W). Cyclothone spp. showed, by far, the largest biomass (126.90 ± 86.20 mg C·m⁻²) compared to A. hemigymnus (0.54 ± 0.44 mg C·m⁻²). The highest concentrations of Cyclothone spp. in the water column were observed between 400 and 600 m and from 1000 to 1500 m depths, both during day and night. For the different species analysed, ETS activity did not show significant differences between diurnal and nocturnal periods. The total average specific respiration of Cyclothone spp. (0.02 ± 0.01 d⁻¹) was lower than that observed for A. hemigymnus (0.05±0.02 d⁻¹). The average carbon respiration of Cyclothone spp. was 2.22 ± 0.81 mg C·m⁻²·d⁻¹, while it was much lower for A. hemigymnus (0.04 ± 0.03 mg C·m⁻²·d⁻¹). The respiration of Cyclothone spp. was lower in the bathypelagic than in the mesopelagic zone (0.84 ± 0.48 vs 1.36 ± 1.01 mg C·m⁻²·d⁻¹, respectively). These results, to our knowledge, provide the first account of remineralisation by this community in the meso and bathypelagic zones of the ocean.En prens

Análisis paleoambiental de los depósitos aluviales de la sección de Cenicero a partir de las asociaciones de ostrácodos (Mioceno inferior, NO de la Cuenca del Ebro)

In this work we perform for the first time a palaeoenvironmental and biostratigraphic analysis of the lower Miocene alluvial deposits of the Cenicero section (NW sector of the Ebro Basin; N Iberian Peninsula), based on the ostracod and micromammal assemblages. One of the main characteristics of this section is the unusual abundance on non-reworked ostracods present in the studied samples compared to other European sequences of similar age and sedimentary environment. This fact has allowed us to develop precise palaeoenvironmental reconstructions. The variations of the identified ostracod assemblages, defined by species such as Cyclocypris laevis, Ilyocypris bradyi, Ilyocypris gibba, Limnocythere sp. or Pseudocandona parallela, record the development of small, ephem-eral and shallow ponds in a distal alluvial and/or floodplain environment. Towards the upper part of the section the ponds appear to be less ephemeral, being the aquatic systems more stable for ostracods development. Variations in the water temperature and salinity have been observed along the section, which are related to changes in the local pluviometric regime. On the other hand, the presence of micromammals in one of the studied samples has allowed the precise dating of this section. Thus, the presence of Armantomys daamsi dates the Cenicero section as Agenian (lower Miocene), local zone Y2 (MN2).En este trabajo se realiza, por vez primera, un análisis paleoambiental y bioestratigráfico de los depósitos aluviales del Mioceno inferior de la sección de Cenicero (sector NO de la Cuenca del Ebro; N de la Península Ibérica), a partir de las asociaciones de ostrácodos y micromamíferos preservadas en estos materiales. Una de las principales características de esta sección es la inusual abundancia de ejemplares de ostrácodos no transportados, en comparación con otras secciones europeas de edad y ambiente sedimentario similares, lo que permite hacer inferencias paleoambientales precisas. La variación en las asociaciones de ostrácodos identificadas, defini-das por especies como Cyclocypris laevis, Ilyocypris bradyi, Ilyocypris gibba, Limnocythere sp. o Pseudocandona parallela, parece sugerir el desarrollo de pequeños cuerpos de agua dulce, someros y efímeros, enmarcados en un ambiente general aluvial distal y/o de llanura de inundación. Hacia techo de la sección, se registra una mayor permanencia temporal de estas acumulaciones y condiciones más estables y favorables del medio para el desarrollo de los ostrácodos. Así mismo, se observan variaciones en la temperatura y salinidad del agua a lo largo de la sección, que podrían estar relacionadas con cambios en el régimen pluviométrico local. La presencia de micromamíferos en uno de los niveles estudiados ha permitido obtener una datación precisa de la sección. Así, la aparición de Armantomys daamsi sitúa la sección de Cenicero dentro de la zona local Y2 (MN2) de edad Ageniense (Mioceno inferior)

Mo–Catalyzed One-Pot Synthesis of N-Polyheterocycles from Nitroarenes and Glycols with Recycling of the Waste Reduction Byproduct. Substituent-Tuned Photophysical Properties

A catalytic domino reduction–imine formation– intramolecular cyclization–oxidation for the general synthesis of a wide variety of biologically relevant N-polyheterocycles, such as quinoxaline- and quinoline-fused derivatives, and phenanthridines, is reported. A simple, easily available, and environmentally friendly dioxomolybdenum(VI) complex has proven to be a highly efficient and versatile catalyst for transforming a broad range of starting nitroarenes involving several redox processes. Not only is this a sustainable, stepeconomical as well as air- and moisture-tolerant method, but also it is worth highlighting that the waste byproduct generated in the first step of the sequence is recycled and incorporated in the final target molecule, improving the overall synthetic efficiency. Moreover, selected indoloquinoxalines have been photophysically characterized in cyclohexane and toluene with exceptional fluorescence quantum yields above 0.7 for the alkyl derivatives.Junta de Castilla y León and FEDER (BU291P18 and BU049P20) and Ministerio de Economía y Competitividad (MINECO) and FEDER (CTQ2016-75023-C2-1P) for financial support. The project leading to these results has also received funding from “la Caixa” Foundation, under the agreement (LCF/PR/PR18/51130007) (CAIXA-UBU001). R.H.-R. thanks Ministerio de Educación for a FPU predoctoral contract. S.S P. thanks Junta de Castilla y León and FSE and FEDER for a postdoctoral contract

Filamin C variants are associated with a distinctive clinical and immunohistochemical arrhythmogenic cardiomyopathy phenotype.

BACKGROUND: Pathogenic variants in the filamin C (FLNC) gene are associated with inherited cardiomyopathies including dilated cardiomyopathy with an arrhythmogenic phenotype. We evaluated FLNC variants in arrhythmogenic cardiomyopathy (ACM) and investigated the disease mechanism at a molecular level. METHODS: 120 gene-elusive ACM patients who fulfilled diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy (ARVC) were screened by whole exome sequencing. Fixed cardiac tissue from FLNC variant carriers who had died suddenly was investigated by histology and immunohistochemistry. RESULTS: Novel or rare FLNC variants, four null and five variants of unknown significance, were identified in nine ACM probands (7.5%). In FLNC null variant carriers (including family members, n = 16) Task Force diagnostic electrocardiogram repolarization/depolarization abnormalities were uncommon (19%), echocardiography was normal in 69%, while 56% had >500 ventricular ectopics/24 h or ventricular tachycardia on Holter and 67% had late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMRI). Ten gene positive individuals (63%) had abnormalities on ECG or CMRI that are not included in the current diagnostic criteria for ARVC. Immunohistochemistry showed altered key protein distribution, distinctive from that observed in ARVC, predominantly in the left ventricle. CONCLUSIONS: ACM associated with FLNC variants presents with a distinctive phenotype characterized by Holter arrhythmia and LGE on CMRI with unremarkable ECG and echocardiographic findings. Clinical presentation in asymptomatic mutation carriers at risk of sudden death may include abnormalities which are currently non-diagnostic for ARVC. At the molecular level, the pathogenic mechanism related to FLNC appears different to classic forms of ARVC caused by desmosomal mutations

Synbiotic therapy decreases microbial translocation and inflammation and improves immunological status in HIV-infected patients: a double-blind randomized controlled pilot trial

BACKGROUND: HIV-infection results in damage and dysfunction of the gastrointestinal system. HIV enteropathy includes pronounced CD4+ T-cell loss, increased intestinal permeability, and microbial translocation that promotes systemic immune activation, which is implicated in disease progression. A synbiotic is the combination of probiotics and prebiotics that could improve gut barrier function. Our study goal was to determine whether the use of a synbiotic, probiotics or a prebiotic can recover immunological parameters in HIV-infected subjects through of a reduction of microbial translocation and pro-inflammatory cytokine production. METHODS: A randomized, double-blind controlled study was performed; twenty Antiretroviral treatment-naïve HIV-infected subjects were subgrouped and assigned to receive a synbiotic, probiotics, a prebiotic, or a placebo throughout 16 weeks. RESULTS: We had no reports of serious adverse-events. From baseline to week 16, the synbiotic group showed a reduction in bacterial DNA concentrations in plasma (p = 0.048). Moreover, the probiotic and synbiotic groups demonstrated a decrease in total bacterial load in feces (p = 0.05). The probiotic group exhibited a significant increment of beneficial bacteria load (such as Bifidobacterium; p = 0.05) and a decrease in harmful bacteria load (such as Clostridium; p = 0.063). In the synbiotic group, the CD4+ T-cells count increased (median: +102 cells/μL; p = 0.05) and the level of Interleukin 6 cytokine decreased significantly (p = 0.016). CONCLUSIONS: Our study showed a significant increase in CD4+ T lymphocyte levels in the synbiotic group, which could delay the initiation of antiretroviral therapy and decrease costs in countries with limited resources

VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory

VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l. in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design, construction techniques and data acquisition system of the HAWC observatory. HAWC is an air-shower array currently under construction at the same site of VAMOS with the purpose to study the TeV sky. The VAMOS setup included six water Cherenkov detectors and two different data acquisition systems. It was in operation between October 2011 and May 2012 with an average live time of 30%. Besides the scientific verification purposes, the eight months of data were used to obtain the results presented in this paper: the detector response to the Forbush decrease of March 2012, and the analysis of possible emission, at energies above 30 GeV, for long gamma-ray bursts GRB111016B and GRB120328B.Comment: Accepted for pubblication in Astroparticle Physics Journal (20 pages, 10 figures). Corresponding authors: A.Marinelli and D.Zaboro