4,911 research outputs found

    Complexity-Aware Assignment of Latent Values in Discriminative Models for Accurate Gesture Recognition

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    Many of the state-of-the-art algorithms for gesture recognition are based on Conditional Random Fields (CRFs). Successful approaches, such as the Latent-Dynamic CRFs, extend the CRF by incorporating latent variables, whose values are mapped to the values of the labels. In this paper we propose a novel methodology to set the latent values according to the gesture complexity. We use an heuristic that iterates through the samples associated with each label value, stimating their complexity. We then use it to assign the latent values to the label values. We evaluate our method on the task of recognizing human gestures from video streams. The experiments were performed in binary datasets, generated by grouping different labels. Our results demonstrate that our approach outperforms the arbitrary one in many cases, increasing the accuracy by up to 10%.Comment: Conference paper published at 2016 29th SIBGRAPI, Conference on Graphics, Patterns and Images (SIBGRAPI). 8 pages, 7 figure

    Influence of a cognitive behavioural training program on health: a study among primary teachers

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    Este estudio longitudinal se llevó a cabo para evaluar la eficacia de un programa de entrenamiento cognitivo-conductual que se diseñó para modificar los procesos cognitivos y emocionales relacionados con el estrés laboral en una muestra de profesores. El grupo de entrenamiento constaba de 21 profesores, y el grupo no entrenado estaba compuesto por 16 profesores. El programa de entrenamiento se dividió en cuatro sesiones presenciales y el intervalo entre el tiempo 1 y tiempo 2 fue de 4 meses. El programa de entrenamiento redujo significativamente los niveles de problemas psicosomáticos en el grupo de entrenamiento del tiempo 1 al tiempo 2, y aumentó significativamente los niveles de cortisol del tiempo 1 al tiempo 2

    On opportunities and threats to conserve the phylogenetic diversity of neotropical palms

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    Aim: Palms are an ecologically and societally important plant group, with high diversity in the Neotropics. Here, we estimated the impacts of future climate change on phylogenetic diversity (PD) of Neotropical palms under varying climatic and dispersal scenarios, assessed the effectiveness of the established network of protected areas (PAs) for conserving palms PD today and in 2070, and identified priority areas for the conservation of palm species and their evolutionary history in the face of climate change. Location: Neotropics. Methods: We used ecological niche modelling to estimate the distribution of 367 species in the present and for 2070 based on two greenhouse gas emission and two dispersal scenarios. We calculated Faith's PD within each five arc-minute grid cell to evaluate the effectiveness of PAs relative to null models and used phylogenetic spatial prioritisation analysis to detect priority areas. Results: We found that even under the most optimistic climatic and dispersal scenarios, the established network of PAs performed poorly in safeguarding palms PD under both current conditions and those projected for 2070. Significant losses in PD inside PAs are expected under future climate conditions, especially if species are unable to disperse to suitable areas. Nevertheless, a modest and strategic increase in the number of PAs could considerably improve the protection of palms PD in the present and 2070. Main conclusions: The PD of Neotropical palms is poorly represented within the established network of PAs, at both present and in 2070. A higher realised dispersal rates would diminish PD losses inside the network of PAs. The conservation of palm PD can be improved through the expansion of PAs in strategic regions such as the upper portion of the Amazon Basin, Tropical Andes and Mesoamerica.Fil: Velazco, Santiago José Elías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Svenning, Jens-christian. University Aarhus; DinamarcaFil: Ribeiro, Bruno R.. Universidade Federal de Goiás; BrasilFil: Laureto, Livia Maira Orlandi. Universidade Federal de Goiás; Brasi

    The enthalpies of dissociation of the N-O bonds in two quinoxaline derivatives

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    The present work reports the first experimental thermochemical study of mono-N-oxides derived from quinoxaline, namely, 3-methoxycarbonyl-2-methyl-quinoxaline N-oxide and 3-ethoxycarbonyl-2-methyl-quinoxaline N-oxide. The values of the enthalpies of formation, in the condensed state, and of the enthalpies of sublimation, derived from static bomb calorimetry and Calvet microcalorimetry measurements, respectively, are combined to derive the standard molar enthalpies of formation in the gaseous phase for these two compounds. From the latter values, the first and second N-O bond dissociation enthalpies for the corresponding di-N-oxides have been obtained. The gas-phase experimental results are also compared with calculated data obtained with a density functional theory approach. Copyright (c) 2008 John Wiley & Sons, Ltd

    Improved Poly (D,L-lactide) nanoparticles-based formulation for hair follicle targeting

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    Objective Hair follicles are widely recognized as the preferential target and site of accumulation for nanoparticles after topical application. This feature is of particular importance for hair cosmetics, having the potential to refine the treatment of several hair follicle-related disorders. The aim of this work was to improve the preparation of Poly (D,L-lactide) (PLA) nanoparticles for in vivo follicular target and drug delivery. Methods Envisaging a future industrial scale-up of the process, nanoprecipitation method was used to prepare PLA nanoparticles: the effect of several processing parameters on their properties was examined and the yield of nanoparticles formation determined. Encapsulation efficiencies and in vitro release profiles of lipophilic and hydrophilic model compounds were also assessed. In vitro cytotoxicity and ex vivo penetration studies were performed on a reference skin cell line (NCTC2455, human skin keratinocytes) and porcine skin, respectively. Results Using acetone : ethanol (50 : 50, v/v) as the solvent phase, 0.6% (w/w) of Pluronic® F68 as a surfactant agent and agitation to mix the solvent and non-solvent phases, a monodispersed population of non-cytotoxic spherical nanoparticles of approximately 150 nm was obtained. The yield of nanoparticles for this formulation was roughly 90%. After encapsulation of model compounds, no significant changes were found in the properties of particles and the entrapment efficiencies were above 80%. The release kinetics of dyes from PLA nanoparticles indicate an anomalous transport mechanism (diffusion and polymer degradation) for Nile Red (lipophilic) and a Fickian diffusion of first order for fluorescein 5(6)-isothiocyanate (hydrophilic). Ex vivo skin penetration studies confirmed the presence of nanoparticles along the entire follicular ducts. Conclusions The optimized method allows the preparation of ideal PLA nanoparticles-based formulations for hair follicle targeting. PLA nanoparticles can effectively transport and release lipophilic and hydrophilic compounds into the hair follicles, and the yields obtained are acceptable for industrial purposes.Objectif Les follicules pileux sont largement reconnus comme la cible préférentielle et le site de l'accumulation des nanoparticules après application topique. Cette caractéristique est particulièrement importante pour les produits cosmétiques pour les cheveux, ayant la possibilité d'affiner le traitement de plusieurs troubles des follicules de cheveux. Le but de ce travail était d'améliorer la préparation de nanoparticules poly (D,L-lactide) (PLA) pour une administration folliculaire in vivo ciblée de drogues. Méthodes En envisageant un avenir à l’échelle industrielle du procédé, une méthode de nanoprécipitation a été utilisé pour préparer des nanoparticules de PLA: l'effet de plusieurs paramètres de traitement sur leurs propriétés a été examiné et le rendement de la formation des nanoparticules a été déterminé. Les efficacités d'encapsulation et de profils de libération in vitro de composés modèles lipophiles et hydrophiles ont également été évaluées. La cytotoxicité in vitro et ex vivo des études de pénétration a été effectuée sur une lignée de cellules de peau de référence (NCTC2455, des kératinocytes de peau humaine) et la peau de porc, respectivement. Resultats En utilisant l'acétone : éthanol (50 : 50, v/v) comme phase solvant, 0,6% (p/p) de Pluronic® F68 à titre d'agent tensioactif et l'agitation pour mélanger les phases de solvant et de non-solvant, une population monodispersée des nanoparticules sphériques non cytotoxiques d'environ 150 nm a été obtenue. Le rendement de nanoparticules pour cette formulation était d'environ 90%. Après encapsulation de composés modèles, aucune modification significative n'a été observée dans les propriétés des particules et les efficacités de piégeage ont été supérieures à 80%. La cinétique de libération de colorants de nanoparticules de PLA indique un mécanisme de transport anormal (diffusion et dégradation de polymère) pour le rouge Nil (lipophile) et une diffusion selon Fick de premier ordre pour FITC (hydrophile). Les études de pénétration ex vivo de la peau ont confirmé la présence de nanoparticules sur tous les conduits folliculaires. Conclusions La méthode optimisée permet la préparation de formulations à base de nanoparticules de PLA, idéales pour ciblage du follicule pileux. Les nanoparticules de PLA peuvent effectivement transporter et libérer des composés lipophiles et hydrophiles dans les follicules pileux; les rendements obtenus sont acceptables à des fins industrielles.The authors thank to the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and to the Project “BioHealth – Biotechnology and Bioengineering approaches to improve health quality”, Ref. NORTE- 07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER. This work was partly supported by FEDER through POFC–582 COMPETE and by Portuguese funds from FCT– Fundacão Para a Ciência e a Tecnologia through the project PEst-OE/BIA/UI4050/2014. The authors thank C. Botelho for technical assistance

    Towards Studying Hierarchical Assembly in Real Time: A Milky Way Progenitor Galaxy at z = 2.36 under the Microscope

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    We use Hubble Space Telescope (HST) imaging and near-infrared spectroscopy from Keck/MOSFIRE to study the sub-structure around the progenitor of a Milky Way-mass galaxy in the Hubble Frontier Fields (HFF). Specifically, we study an re=4030+70r_e = 40^{+70}_{-30}pc, M108.2MM_{\star} \sim 10^{8.2} M_{\odot} rest-frame ultra-violet luminous "clump" at a projected distance of \sim100~pc from a M109.8M_{\star} \sim 10^{9.8}M_{\odot} galaxy at z=2.36z = 2.36 with a magnification μ=5.21\mu = 5.21. We measure the star formation history of the clump and galaxy by jointly modeling the broadband spectral energy distribution from HST photometry and Hα\alpha from MOSFIRE spectroscopy. Given our inferred properties (e.g., mass, metallicity, dust) of the clump and galaxy, we explore scenarios in which the clump formed \emph{in-situ} (e.g., a star forming complex) or \emph{ex-situ} (e.g., a dwarf galaxy being accreted). If it formed \emph{in-situ}, we conclude that the clump is likely a single entity as opposed to a aggregation of smaller star clusters, making it one of the most dense star clusters cataloged. If it formed \emph{ex-situ}, then we are witnessing an accretion event with a 1:40 stellar mass ratio. However, our data alone are not informative enough to distinguish between \emph{in-situ} and \emph{ex-situ} scenarios to a high level of significance. We posit that the addition of high-fidelity metallicity information, such as [OIII]4363\AA, which can be detected at modest S/N with only a few hours of JWST/NIRSpec time, may be a powerful discriminant. We suggest that studying larger samples of moderately lensed sub-structures across cosmic time can provide unique insight into the hierarchical formation of galaxies like the Milky Way.Comment: Accepted to MNRA
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