604 research outputs found

    A New Genus of Miniaturized and Pug-Nosed Gecko from South America (Sphaerodactylidae: Gekkota)

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    Sphaerodactyl geckos comprise five genera distributed across Central and South America and the Caribbean. We estimated phylogenetic relationships among sphaerodactyl genera using both separate and combined analyses of seven nuclear genes. Relationships among genera were incongruent at different loci and phylogenies were characterized by short, in some cases zero-length, internal branches and poor phylogenetic support at most nodes. We recovered a polyphyletic Coleodactylus, with Coleodactylus amazonicus being deeply divergent from the remaining Coleodactylus species sampled. The C. amazonicus lineage possessed unique codon deletions in the genes PTPN12 and RBMX while the remaining Coleodactylus species had unique codon deletions in RAG1. Topology tests could not reject a monophyletic Coleodactylus, but we show that short internal branch lengths decreased the accuracy of topology tests because there were not enough data along these short branches to support one phylogenetic hypothesis over another. Morphological data corroborated results of the molecular phylogeny, with Coleodactylus exhibiting substantial morphological heterogeneity. We identified a suite of unique craniofacial features that differentiate C. amazonicus not only from other Coleodactylus species, but also from all other geckos. We describe this novel sphaerodactyl lineage as a new genus, Chatogekko gen. nov. We present a detailed osteology of Chatogekko, characterizing osteological correlates of miniaturization that provide a framework for future studies in sphaerodactyl systematics and biology

    Multiscale Modelling and Simulation of Advanced Battery Materials

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    Development of efficient strategies for the rational design of materials involved in the production and storage of renewable energy is essential for accelerating the transition to a low-carbon economy. To contribute to this goal, we propose a novel workflow for the assessment and optimization of battery materials. The approach effectively combines quantum and atomistic modelling/simulations, enhanced by efficient sampling, Bayesian parameterization, and experimental information. It is implemented to study prospective materials for lithium and sodium batteries

    M2LADS: A System for Generating MultiModal Learning Analytics Dashboards

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    In this article, we present a Web-based System called M2LADS, which supports the integration and visualization of multimodal data recorded in learning sessions in a MOOC in the form of Web-based Dashboards. Based on the edBB platform, the multimodal data gathered contains biometric and behavioral signals including electroencephalogram data to measure learners' cognitive attention, heart rate for affective measures, visual attention from the video recordings. Additionally, learners' static background data and their learning performance measures are tracked using LOGCE and MOOC tracking logs respectively, and both are included in the Web-based System. M2LADS provides opportunities to capture learners' holistic experience during their interactions with the MOOC, which can in turn be used to improve their learning outcomes through feedback visualizations and interventions, as well as to enhance learning analytics models and improve the open content of the MOOC

    Unveiling Interfacial Li-Ion Dynamics in Li7La3Zr2O12/PEO(LiTFSI) Composite Polymer-Ceramic Solid Electrolytes for All-Solid-State Lithium Batteries

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    Unlocking the full potential of solid-state electrolytes (SSEs) is key to enabling safer and more-energy dense technologies than today’s Li-ion batteries. In particular, composite materials comprising a conductive, flexible polymer matrix embedding ceramic filler particles are emerging as a good strategy to provide the combination of conductivity and mechanical and chemical stability demanded from SSEs. However, the electrochemical activity of these materials strongly depends on their polymer/ceramic interfacial Li-ion dynamics at the molecular scale, whose fundamental understanding remains elusive. While this interface has been explored for nonconductive ceramic fillers, atomistic modeling of interfaces involving a potentially more promising conductive ceramic filler is still lacking. We address this shortfall by employing molecular dynamics and enhanced Monte Carlo techniques to gain unprecedented insights into the interfacial Li-ion dynamics in a composite polymer-ceramic electrolyte, which integrates polyethylene oxide plus LiN(CF3SO2)2 lithium imide salt (LiTFSI), and Li-ion conductive cubic Li7La3Zr2O12 (LLZO) inclusions. Our simulations automatically produce the interfacial Li-ion distribution assumed in space-charge models and, for the first time, a long-range impact of the garnet surface on the Li-ion diffusivity is unveiled. Based on our calculations and experimental measurements of tensile strength and ionic conductivity, we are able to explain a previously reported drop in conductivity at a critical filler fraction well below the theoretical percolation threshold. Our results pave the way for the computational modeling of other conductive filler/polymer combinations and the rational design of composite SSEs.-Juan de la Cierva grant IJC2018-037214-I, -PID2019-106519RB-I00, as -HPC-Europa3 grant HPC17ERWTO -AI in BCAM, EXP. 2019/004

    Breit Equation with Form Factors in the Hydrogen Atom

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    The Breit equation with two electromagnetic form-factors is studied to obtain a potential with finite size corrections. This potential with proton structure effects includes apart from the standard Coulomb term, the Darwin term, retarded potentials, spin-spin and spin-orbit interactions corresponding to the fine and hyperfine structures in hydrogen atom. Analytical expressions for the hyperfine potential with form factors and the subsequent energy levels including the proton structure corrections are given using the dipole form of the form factors. Numerical results are presented for the finite size corrections in the 1S and 2S hyperfine splittings in the hydrogen atom, the Sternheim observable D21D_{21} and the 2S and 2P hyperfine splittings in muonic hydrogen. Finally, a comparison with some other existing methods in literature is presented.Comment: 24 pages, Latex, extended version, title change

    Relationship between health-related fitness and quality of life in elderly with type 2 diabetes: an exploratory study in the province of Seville

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    Under a Creative Commons license.[Objetivos]: Caracterizar a la población adulta-mayor afectada por diabetes mellitus tipo 2 (DM2) tratada en las consultas de atención primaria en cuanto al nivel de condición física relacionada con la salud (CFRS) y calidad de vida relacionada con la salud (CVRS), y por otro lado, corroborar si existe relación entre los diferentes test de CFRS y la CVRS. [Método]: Se utilizó un diseño transversal observacional de casos y controles para comparar la CFRS y la CVRS (evaluada mediante el cuestionario EQ-5D-3L) entre 42 pacientes con DM2 y 54 pacientes sin DM2, y se estableció la relación existente entre la CFRS y la CVRS en los pacientes con DM2. [Resultados]: En cuanto a la CFRS, los pacientes con DM2 obtuvieron mayores resultados en el test de dinamometría manual que sus pares sin dicha afección (p < 0,025). Los valores alcanzados en el test sit and reach fueron mayores en el grupo control que en el grupo DM2 (p < 0,001). No se detectaron diferencias estadísticamente significativas en cuanto a la CVRS entre ambos grupos. El coeficiente de correlación de Pearson desveló un nivel de correlación de moderado a alto entre los componentes de la CVRS y los test de fuerza, movilidad y equilibrio que componen la CFRS (p < 0,05). [Conclusiones]: Este estudio muestra la asociación existente entre la CVRS evaluada con el EQ-5D-3L y los test de fuerza, movilidad y equilibrio dinámico en pacientes con DM2 tratados en atención primaria, cualidades vitales para el desarrollo de las actividades de la vida diaria de estos pacientes.[Objectives]: To characterize the type 2 diabetic (DM2) population treated in primary care consultations in regard of Health-Related Fitness (HRF) and Health-Related Quality of Life (HRQoL), and, on the other hand, to confirm if there is a relationship between HRF and HRQoL in DM2 patients. [Methods]: A cross-sectional, observational, case-control study was performed to compare the HRF and HRQoL between 42 DM2 patients and 54 patients without DM2 and the relationship between these two concepts was revealed. [Results]: In regard of HRF, statistically significant differences were found in the hand dynamometer test in favor of DM2 patients group (p = , 025) and statistically significant differences were achieved in favor of the reference group in sit and reach test (p = , 001). Pearson's correlation coefficient revealed a moderate to high level of correlation between the different dimensions and index of EQ-5D-3L and strength, mobility and balance tests (p < ,05). [Conclusions]: This study showsthe relationship between EQ-5D-3L componentsand strength, mobility and balance tests in DM2 patients treated in primary care, key functional capacities to a correct development of daily activities in these patients.A los autores del presente trabajo les gustaría agradecer la colaboración prestada por el Centro de Salud Los Bermejales por financiar parcialmente este proyecto.Open Access funded by Consejería de Educación, Cultura y Deporte de la Junta de Andalucía.Peer Reviewe

    Hickson-like compact groups inhabiting different environments

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    Although Compact Groups of galaxies (CGs) have been envisioned as isolated extremely dense structures in the Universe, it is accepted today that many of them could be not as isolated as thought. In this work, we study Hickson-like CGs identified in the Sloan Digital Sky Survey Data Release 16 to analyse these systems and their galaxies when embedded in different cosmological structures. To achieve this goal, we identify several cosmological structures where CGs can reside: Nodes of filaments, Loose Groups, Filaments and cosmic Voids. Our results indicate that 45 per cent of CGs do not reside in any of these structures, i.e., they can be considered non-embedded or isolated systems. Most of the embedded CGs are found inhabiting Loose Groups and Nodes, while there are almost no CGs residing well inside cosmic Voids. Some physical properties of CGs vary depending on the environment they inhabit. CGs in Nodes show the largest velocity dispersions, the brightest absolute magnitude of the first-ranked galaxy, and the smallest crossing times, while the opposite occurs in Non-Embedded CGs. When comparing galaxies in all the environments and galaxies in CGs, CGs show the highest fractions of red/early-type galaxy members in most of the absolute magnitudes ranges. The variation between galaxies in CGs inhabiting one or another environment is not as significant as the differences caused by belonging or not to a CG. Our results suggest a plausible scenario for galaxy evolution in CGs in which both, large-scale and local environments play essential roles.Comment: 16 pages, 9 figures, 1 table, accepted for publication in MNRA

    The development of cephalic armor in the tokay gecko (Squamata: Gekkonidae: Gekko gecko)

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    Armored skin resulting from the presence of bony dermal structures, osteoderms, is an exceptional phenotype in gekkotans (geckos and flap‐footed lizards) only known to occur in three genera: Geckolepis, Gekko, and Tarentola. The Tokay gecko (Gekko gecko LINNAEUS 1758) is among the best‐studied geckos due to its large size and wide range of occurrence, and although cranial dermal bone development has previously been investigated, details of osteoderm development along a size gradient remain less well‐known. Likewise, a comparative survey of additional species within the broader Gekko clade to determine the uniqueness of this trait has not yet been completed. Here, we studied a large sample of gekkotans (38 spp.), including 18 specimens of G. gecko, using X‐rays and high‐resolution computed tomography for visualizing and quantifying the dermal armor in situ. Results from this survey confirm the presence of osteoderms in a second species within this genus, Gekko reevesii GRAY 1831, which exhibits discordance in timing and pattern of osteoderm development when compared with its sister taxon, G. gecko. We discuss the developmental sequence of osteoderms in these two species and explore in detail the formation and functionality of these enigmatic dermal ossifications. Finally, we conducted a comparative analysis of endolymphatic sacs in a wide array of gekkotans to explore previous ideas regarding the role of osteoderms as calcium reservoirs. We found that G. gecko and other gecko species with osteoderms have highly enlarged endolymphatic sacs relative to their body size, when compared to species without osteoderms, which implies that these membranous structures might fulfill a major role of calcium storage even in species with osteoderms.Distribution of osteoderms in the skull of a large sized Tokay gecko (Gekko gecko).Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153558/1/jmor21092_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153558/2/jmor21092.pd
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