518 research outputs found

    Solución en forma cerrada de sistemas acoplados de Riccati en teoría de juegos discretos

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    En este artículo se propone una solución no iterativa de sistemas acoplados matriciales de Riccati que aparecen en la resolución de teoría de juegos discretos cuando se aplica la estrategia de Nash en bucle abierto. Mediante el uso de transformaciones algebraicas apropiadas el problema. Se transforma en otro desacoplado para el que una solución en forma cerrada es viable.Peer Reviewe

    Numerical Solutions of Matrix Differential Models using Cubic Matrix Splines II

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    This paper presents the non-linear generalization of a previous work on matrix differential models. It focusses on the construction of approximate solutions of first-order matrix differential equations Y'(x)=f(x,Y(x)) using matrix-cubic splines. An estimation of the approximation error, an algorithm for its implementation and illustrative examples for Sylvester and Riccati matrix differential equations are given.Comment: 14 pages; submitted to Math. Comp. Modellin

    Ordinal and nominal classication of wind speed from synoptic pressure patterns

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    Wind speed reconstruction is a challenging problem in areas (mainly wind farms) where there are not direct wind measures available. Di erent approaches have been applied to this reconstruction, such as measure-correlatepredict algorithms, approaches based on physical models such as reanalysis methods, or more recently, indirect measures such as pressure, and its relation to wind speed. This paper adopts the latter method, and deals with wind speed estimation in wind farms from pressure measures, but including different novelties in the problem treatment. Existing synoptic pressure-based indirect approaches for wind speed estimation are based on considering the wind speed as a continuous target variable, estimating then the corresponding wind series of continuous values. However, the exact wind speed is not always needed by wind farms managers, and a general idea of the level of speed is, in the majority of cases, enough to set functional operations for the farm (such as wind turbines stop, for example). Moreover, the accuracy of the models obtained is usually improved for the classi cation task, given that the problem is simpli ed. Thus, this paper tackles the problem of wind speed prediction from synoptic pressure patterns by considering wind speed as a discrete variable and, consequently, wind speed prediction as a classi cation problem, with four wind level categories: low, moderate, high or very high. Moreover, taking into account that these four di erent classes are associated to four values in an ordinal scale, the problem can be considered as an ordinal regression problem. The performance of several ordinal and nominal classi- ers and the improvement achieved by considering the ordering information are evaluated. The results obtained in this paper present the Support Vector Machine as the best tested classi er for this task. In addition, the use of the intrinsic ordering information of the problem is shown to signi cantly improve ranks with respect to nominal classi cation, although di erences in accuracy are smal

    Diagnóstico citológico de las recidivas tumorales de ameloblastoma: presentación de dos casos clínicos

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    Introducción: Los ameloblastomas son los tumores odontogénicos más frecuentes del maxilar. A pesar de su aspecto citohistológico de benignidad, se comportan como tumores invasivos, recidivantes y con posibilidad de metastatizar. La P.A.A.F. es una prueba rápida e incruenta que proporciona un diagnóstico prequirúrgico evitando, en ocasiones, tomas biópsicas destinadas al diagnóstico. Presentamos las características citológicas de dos casos de recidiva yugal de ameloblastoma de rama mandibular diagnosticados por PAAF, así como su correlación citohistológica. Casos clínicos: Dos pacientes, una mujer de 36 años y un varón de 62 años, que acuden por tumoración mandibular de escasos meses de evolución. En ambos casos, la primera aproximación diagnóstica fue junto a los estudios radiológicos el estudio histológico de la masa tumoral. Tras la extirpación terapeútica, ambos casos recidivaron. El diagnóstico de las recidivas fue establecido citológicamente mediante PAAF. Las extensiones citológicas mostraron un fondo granular con aislados macrófagos y células multinucleadas gigantes y una abundante celularidad epitelial de aspecto basaloide dispuesta en grupos cohesivos configurando imágenes de empalizada periférica, así como pequeños grupos de células de metaplasia escamosa. Discusión: La PAAF se considera como un método diagnóstico rápido, incruento y fiable en el diagnóstico del ameloblastoma. La citología de estos tumores revela los componentes de la lesión que, en general, son suficientes para llegar al diagnóstico de ameloblastoma, especialmente en casos de recidiva.Introduction: Ameloblastomas are the most frequent odontogenic tumors of the maxilla. In spite of their benign cytohistological appearance, they behave as invasive recurring tumors, with the possibility of metastasis. FNAB is a rapid, bloodless test that provides a pre-surgical diagnosis, thus, on occasions avoiding the need for diagnostic biopsies. We present the cytological characteristics of two cases of jugal recurrences of mandibular ameloblastomas diagnosed by FNAB, as well as their cytohistological correlation. Clinical cases: Two patients, a 36-year-old woman, and a 62- year-old male who both attended with mandibular swelling of a few months evolution. In both cases the first diagnostic approximation was the histological study of the tumoral mass, together with the radiological studies. Following therapeutic extirpation both cases recurred. The diagnosis of the recurrences was established cytologically by means of FNAB. The cytologic smears revealed a granular background with isolated macrophages and giant multinucleate cells and an abundant epithelial cellularity of basaloid appearance arranged in cohesive groups forming images of peripheral palidasing, as well as small groups of squamous metaplastic cells. Discussion: FNAB is considered to be a rapid, bloodless and reliable method for the diagnosis of ameloblastoma. The cytology of these tumors reveals components of the lesion that, in general, are sufficient for the diagnosis of ameloblastoma, especially in cases of recurrence

    Search for dark matter produced in association with a dark higgs boson decaying into W ± W∓ or ZZ in fully hadronic final states from √s= 13 TeV pp Collisions Recorded with the ATLAS Detector

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    Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UA

    Survival of Atlantic bluefin tuna (Thunnus thynnus) larvae hatched at different salinity and pH conditions

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    In this study, we assessed the effect of environmental salinity and pH as independent factors on larval survival of Atlantic bluefin tuna (ABFT –Thunnus thynnus) together with their whole-body Na+/K+-ATPase and v-type H+-ATPase activities. Fertilized eggs of ABFT were obtained from a spontaneous spawning of broodstock in the farming facilities at El Gorguel (Cartagena, SE Spain) and were transferred to facilities of the Spanish Institute of Oceanography (IEO) in Mazarrón (SE Spain). In a first experiment, eggs (200 fertilized eggs L-1 per treatment, in 3 replicates) were exposed to different salinities treatments and constant pH 8.0 (control) until hatch was completed (50 h post- fertilization, hpf, at 23 ºC): 27, 30, 33, 36, 37, 38 (control), 39, 40, 43, 46 and 49 ppt. In a second experiment eggs (200 fertilized eggs L-1, in 3 replicates) were exposed to seawater salinity (SW: 38 ppt) and four reduced pH treatments until hatch was completed (50 hpf at 23 ºC): 8.0 (control), 7.7, 7.5 and 7.3. An inverse „„U-shaped‟‟ relationship was observed between environmental salinity and number of hatched larvae. An opposite pattern was observed for both Na+/K+-ATPase and H+-ATPase activities in hatched larvae, increasing both activities in groups exposed to extreme salinities. Thus, larval survival was higher at intermediate salinities and lower at the extreme salinities tested. These results suggest higher survival rates with lower active pumps activities. No significant differences in larval survival were observed with pH treatment, but lower H+-ATPase activity was detected at control environmental pH (pH 8.0). Survival results are discussed in terms of osmoregulatory cost adapting to a salinity and pH predicted for the near future scenarios.Versión del edito

    Structural Evidence of Amyloid Fibril Formation in the Putative Aggregation Domain of TDP-43

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    TDP-43 can form pathological proteinaceous aggregates linked to ALS and FTLD. Within the putative aggregation domain, engineered repeats of residues 341-366 can recruit endogenous TDP-43 into aggregates inside cells; however, the nature of these aggregates is a debatable issue. Recently, we showed that a coil to β-hairpin transition in a short peptide corresponding to TDP-43 residues 341-357 enables oligomerization. Here we provide definitive structural evidence for amyloid formation upon extensive characterization of TDP-43(341-357) via chromophore and antibody binding, electron microscopy (EM), solid-state NMR, and X-ray diffraction. On the basis of these findings, structural models for TDP-43(341-357) oligomers were constructed, refined, verified, and analyzed using docking, molecular dynamics, and semiempirical quantum mechanics methods. Interestingly, TDP-43(341-357) β-hairpins assemble into a novel parallel β-turn configuration showing cross-β spine, cooperative H-bonding, and tight side-chain packing. These results expand the amyloid foldome and could guide the development of future therapeutics to prevent this structural conversion.Peer Reviewe

    Bone marrow lesions and magnetic resonanceImaging–detected structural abnormalities in patients with midfoot pain and osteoarthritis: A cross-sectional study

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    To compare magnetic resonance imaging (MRI)–detected structural abnormalities in patients withsymptomatic midfoot osteoarthritis (OA), patients with persistent midfoot pain, and asymptomatic controls, and toexplore the association between MRI features, pain, and foot-related disability. One hundred seven adults consisting of 50 patients with symptomatic and radiographically confirmedmidfoot OA, 22 adults with persistent midfoot pain but absence of radiographic OA, and 35 asymptomatic adultsunderwent 3T MRI of the midfoot and clinical assessment. MRIs were read for the presence and severity of abnormal-ities (bone marrow lesions [BMLs], subchondral cysts, osteophytes, joint space narrowing [JSN], effusion-synovitis,tenosynovitis, and enthesopathy) using the Foot Osteoarthritis MRI Score. Pain and foot-related disability wereassessed with the Manchester Foot Pain and Disability Index. The severity sum score of BMLs in the midfoot was greater in patients with midfoot pain and no signs ofOA on radiography compared to controls (P= 0.007), with a pattern of involvement in the cuneiform–metatarsal jointssimilar to that in patients with midfoot OA. In univariable models, BMLs (ρ= 0.307), JSN (ρ= 0.423), and subchondralcysts (ρ= 0.302) were positively associated with pain (P< 0.01). In multivariable models, MRI abnormalities were notassociated with pain and disability when adjusted for covariates. In individuals with persistent midfoot pain but no signs of OA on radiography, MRIfindings suggestedan underrecognized prevalence of OA, particularly in the second and third cuneiform–metatarsal joints, where BMLpatterns were consistent with previously recognized sites of elevated mechanical loading. Joint abnormalities werenot strongly associated with pain or foot-related disability
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