52 research outputs found

    Path planning for active tensegrity structures

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    This paper presents a path planning method for actuated tensegrity structures with quasi-static motion. The valid configurations for such structures lay on an equilibrium manifold, which is implicitly defined by a set of kinematic and static constraints. The exploration of this manifold is difficult with standard methods due to the lack of a global parameterization. Thus, this paper proposes the use of techniques with roots in differential geometry to define an atlas, i.e., a set of coordinated local parameterizations of the equilibrium manifold. This atlas is exploited to define a rapidly-exploring random tree, which efficiently finds valid paths between configurations. However, these paths are typically long and jerky and, therefore, this paper also introduces a procedure to reduce their control effort. A variety of test cases are presented to empirically evaluate the proposed method. (C) 2015 Elsevier Ltd. All rights reserved.Peer ReviewedPostprint (author's final draft

    Estudi de la influència de la força de pretensat en el comportament mecànic del material Fabric-Reinforcement Cementitious Matrix (FRCM)

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    El TFG té com a objectiu estudiar la influència que té el pretensat dels teixits de materials tipus Fabric-Reinforcement Cementitious Matrix (FRCM) a diferents nivells de càrrega sobre les propietats mecàniques del material compostRecerca bibliogràfica sobre la tecnologia a estudiar (FRCM), el disseny, planificació i execució d’una campanya experimental; l’anàlisi crític dels resultats i la redacció d’una memòri

    Exploring EEG for Object Detection and Retrieval

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    This paper explores the potential for using Brain Computer Interfaces (BCI) as a relevance feedback mechanism in content-based image retrieval. We investigate if it is possible to capture useful EEG signals to detect if relevant objects are present in a dataset of realistic and complex images. We perform several experiments using a rapid serial visual presentation (RSVP) of images at different rates (5Hz and 10Hz) on 8 users with different degrees of familiarization with BCI and the dataset. We then use the feedback from the BCI and mouse-based interfaces to retrieve localized objects in a subset of TRECVid images. We show that it is indeed possible to detect such objects in complex images and, also, that users with previous knowledge on the dataset or experience with the RSVP outperform others. When the users have limited time to annotate the images (100 seconds in our experiments) both interfaces are comparable in performance. Comparing our best users in a retrieval task, we found that EEG-based relevance feedback outperforms mouse-based feedback. The realistic and complex image dataset differentiates our work from previous studies on EEG for image retrieval.Comment: This preprint is the full version of a short paper accepted in the ACM International Conference on Multimedia Retrieval (ICMR) 2015 (Shanghai, China

    Exploring EEG for object detection and retrieval

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    This paper explores the potential for using Brain Computer Interfaces (BCI) as a relevance feedback mechanism in contentbased image retrieval. Several experiments are performed using a rapid serial visual presentation (RSVP) of images at different rates (5Hz and 10Hz) on 8 users with different degrees of familiarization with BCI and the dataset. We compare the feedback from the BCI and mouse-based interfaces in a subset of TRECVid images, finding that, when users have limited time to annotate the images, both interfaces are comparable in performance. Comparing our best users in a retrieval task, we found that EEG-based relevance feedback can outperform mouse-based feedback

    Iron deficiency: impact on functional capacity and quality of life in heart failure with preserved ejection fraction

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    The effects of iron deficiency (ID) have been widely studied in heart failure (HF) with reduced ejection fraction. On the other hand, studies in HF with preserved ejection fraction (HFpEF) are few and have included small numbers of participants. The aim of this study was to assess the role that ID plays in functional capacity and quality of life (QoL) in HFpEF while comparing several iron-related biomarkers to be used as potential predictors. ID was defined as ferritin <100 ng/mL or transferrin saturation <20%. Submaximal exercise capacity, measured by the 6-min walking test (6MWT), and QoL, assessed by the Minnesotta Living with Heart Failure Questionnaire (MLHFQ), were compared between iron deficient patients and patients with normal iron status. A total of 447 HFpEF patients were included in the present cross-sectional study, and ID prevalence was 73%. Patients with ID performed worse in the 6MWT compared to patients with normal iron status (ID 271 ± 94 m vs. non-ID 310 ± 108 m, p < 0.01). They also scored higher in the MLHFQ, denoting worse QoL (ID 49 ± 22 vs. non-ID 43 ± 23, p = 0.01). Regarding iron metabolism biomarkers, serum soluble transferrin receptor (sTfR) was the strongest independent predictor of functional capacity (β = −63, p < 0.0001, R2 0.39) and QoL (β = 7.95, p < 0.0001, R2 0.14) in multivariate models. This study postulates that ID is associated with worse functional capacity and QoL in HFpEF as well, and that sTfR is the best iron-related biomarker to predict both. Our study also suggests that the effects of ID could differ among HFpEF patients by left ventricular ejection fractio

    Src-Homology 2 Domain-Containing Phosphatase 2 in Resected EGFR Mutation-Positive Lung Adenocarcinoma

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    Funding: supported by a La Caixa Foundation grant and the Spanish Association Against Cancer (PROYE18012ROSE)EGFR mutation-positive lung adenocarcinoma (LUAD) displays impaired phosphorylation of ERK and Src-homology 2 domain-containing phosphatase 2 (SHP2) in comparison with EGFR wild-type LUADs. We hypothesize that SHP2 expression could be predictive in patients positive with resected EGFR mutation versus patients with EGFR wild-type LUAD. We examined resected LUAD cases from Japan and Spain. mRNA expression levels of AXL, MET, CDCP1, STAT3, YAP1, and SHP2 were analyzed by quantitative reverse transcriptase polymerase chain reaction. The activity of SHP2 inhibitors plus erlotinib were tested in EGFR -mutant cell lines and analyzed by cell viability assay, Western blot, and immunofluorescence. A total of 50 of 100 EGFR mutation-positive LUADs relapsed, among them, patients with higher SHP2 mRNA expression revealed shorter progression-free survival, in comparison with those having low SHP2 mRNA (hazard ratio: 1.83; 95% confidence interval: 1.05-3.23; p = 0.0329). However, SHP2 was not associated with prognosis in the remaining 167 patients with wild-type EGFR. In EGFR -mutant cell lines, the combination of SHP099 or RMC-4550 (SHP2 inhibitors) with erlotinib revealed synergism via abrogation of phosphorylated AKT (S473) and ERK1/2 (T202/Y204). Although erlotinib translocates phosphorylated SHP2 (Y542) into the nucleus, either RMC-4550 alone, or in combination with erlotinib, relocates SHP2 into the cytoplasm membrane, limiting AKT and ERK1/2 activation. Elevated SHP2 mRNA levels are associated with recurrence in resected EGFR mutation-positive LUADs, but not in EGFR wild-type. EGFR tyrosine kinase inhibitors can enhance SHP2 activation, hindering adjuvant therapy. SHP2 inhibitors could improve the benefit of adjuvant therapy in EGFR mutation-positive LUADs

    Pirineos: paisaje, materia, memoria

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    [spa] Para el artista novel, presentar en sociedad su trabajo concluso supone una gran satisfacción. Después de todo un trayecto procesual —no siempre fácil—, supone compartir con la ciudadanía lo poliédrico de toda obra de arte. Sus reflexiones, emociones, sueños y logros se muestran ahora en ese puente energético preconizado por Kandinsky, en el que cada cual debe —si así lo desea— establecer su particular diálogo con la pieza de arte, concluirla, incluso llevarla a nuevas posibilidades desde un código abierto de pensamiento e idiosincrasia. Para el profesorado de enseñanza superior de las artes, acompañar a nuestro alumnado en lo académico no funciona fuera de estrategias y metodologías motivadoras de descubrimiento y autodescubrimiento. El estudiante motivado, al que nosotros de entrada consideramos artista novel, creador potencial, deviene entonces alguien comprometido en su camino profesionalizador: adquiere competencias, elabora defensas y argumentos y soluciona problemas en el campo de la creación artística. Consideramos que una exposición de resultados creativos es potencialmente motivadora. Es un espacio que deviene también ese escaparate crítico e interactivo en el que el artista se encuentra consigo mismo y con los demás. En esta muestra, los docentes, a partir de la invitación del Espacio Pirineos de Graus, hemos puesto en manos de jóvenes artistas el reto de convertir un territorio, los Pirineos, con su amplia realidad natural, social y cultural, en objeto de estudio y conocimiento artístico. Nuestros 14 artistas seleccionados, alumnado de la asignatura Taller de Creación I (grupo P1) del Grado en Bellas Artes de la Universidad de Barcelona, muestran mayoritariamente —desde diferentes lenguajes pictóricos— obras en las que destaca lo sublime del paisaje pirenaico, la relación del ser humano con su naturaleza, la tradición, los hechos históricos e incluso el imaginario popular derivado de sus mitos y leyendas. Destacamos aquí el éxito de la experiencia, desde la excelencia de los resultados, y agradecemos a Espacio Pirineos las facilidades en el desarrollo y presentación en sociedad de este proyecto
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