870 research outputs found
Developing downloadable TUIs for online pedagogic activities
The Web has changed how we interact with the World’s information and knowledge. As a result there have been several changes to the education sector, especially in online distance learning. Nevertheless, most of the e-Learning activities struggle to break the GUI paradigm. The HCI community has focused on the use of Tangible User Interfaces (TUI) for pedagogic purposes thus producing some evidence of the potential that embodied cognition might bring to constructivist learning. New education movements such as the Edupunk movement argue for an empowerment of independent learners, following the constructivist perspective where learners have to have a more active role by experimenting and discovering concepts on their own. However, we think that accessing TUI systems via Web can lead to pedagogic activities that break the GUI paradigm in education on the Web. This paper presents a case study: three prototypes of TUIs for online learning and exploration were developed and tested, investigating the usability and engagement provided by this kind of interactive tools
Densities and phase equilibria of hydrogen, propane and vegetable oil mixtures. Experimental data and thermodynamic modeling
Heterogeneous catalytic gas-liquid reactions are intensified when carried out in the homogenous fluid phase by means of a supercritical co-solvent. For instance, supercritical propane is used to enhance yield in the hydrogenation of vegetable oils. Besides phase equilibrium knowledge, volumetric information is also needed to elucidate kinetic mechanisms and design continuous supercritical reactors. In this work, we report new experimental PvT data of the reactive mixture H2+sunflower oil+propane using the isochoric method. In addition, the phase equilibria and PvT data are modeled with the GCA and RK-PR equations of state, respectively. The isochoric method not only provides PvT information under the reaction conditions, but also the reactive system compressibility, key variable to attain enhanced transport properties in the supercritical reactors.Fil: Hegel, Pablo Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Cotabarren, Natalia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Brignole, Esteban Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Pereda, Selva. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. University of KwaZulu-Natal; Sudáfric
Taphonomy and palaeohistology of ornithischian dinosaur remains from the Lower Cretaceous bonebed of La Cantalera (Teruel, Spain)
The fossiliferous site of La Cantalera-1 (Teruel, Spain) has to date provided remains of more than 30 vertebrate taxa, including dinosaurs, crocodyliforms, pterosaurs, mammals, lizards, turtles, lissamphibians and teleosteans. Located in the lower part of the Blesa Formation (lower Barremian), it is one of the richest vertebrate-bearing deposits from the Lower Cretaceous of the Iberian Peninsula. In this work, taphonomic and palaeohistological studies are carried out on the basis of ornithischian (Ornithopoda and Ankylosauria) dinosaur samples in order to assess the diagenetic processes, to characterize the histological microstructures and, if possible, to make palaeobiological inferences about the state of maturation of the individuals. A variety of techniques are used in the taphonomic study, including scanning electron microscopy (SEM), cathodoluminescence (CL), X-ray diffraction (XRD) and ultraviolet fluorescence (UVF). The bone of the dinosaur samples has been converted into francolite (fluorapatite carbonate); the trabecular cavities are filled with semi-spherical forms of goethite and two different phases of calcite. In addition, the SEM and UVF techniques suggest the activity of coccoid-form bacteria and filaments of bacterial origin (biofilms?) in the bones, which possibly favoured fossilization. The dinosaur remains were subjected to fossil-diagenetic processes in a phreatic environment after a rapid burial, without appreciable seasonality effects. On the other hand, the palaeohistological study of both skeletal and dermal bones found in La Cantalera-1 shows a community of herbivorous dinosaurs composed mostly of immature ornithopods and at least one Polacanthus-like ankylosaur, as suggested by the organizational pattern of structural collagen fibres seen in some samples. The palaeobiological inferences drawn from this study support previous interpretations of a relative abundance of immature ornithischians in La Cantalera-1
Respuesta hipofisaria de FSH, LH, PRL, TSH, HGH y cortisol a un estímulo en humanos pre y post púberes
Tesis inédita de la Universidad Complutense de Madrid, Facultad de Medicina, leída en 1977.El objeto ha sido estudiar por medio de técnicas de radioinmunoanalisis las hormonas del lóbulo anterior hipofisario tras la administración secueneral en una sola prueba de estímulos con efectos aislados conocidos cuyas acciones según esta probado no se interfieren entre si cuando se administran conjuntamente. de esta forma se simplifica una prueba de uso frecuente en edades en las que los trastornos del crecimiento y desarrollo con su variada etnología genética constitucional y hormonal así lo requieren.Fac. de MedicinaTRUEProQuestpu
Respuesta hipofisaria de FSH, LH, PRL, TSH, HGH y cortisol a un estímulo en humanos pre y post púberes
El objeto ha sido estudiar por medio de técnicas de radioinmunoanalisis las hormonas del lóbulo anterior hipofisario tras la administración secueneral en una sola prueba de estímulos con efectos aislados conocidos cuyas acciones según esta probado no se interfieren entre si cuando se administran conjuntamente. de esta forma se simplifica una prueba de uso frecuente en edades en las que los trastornos del crecimiento y desarrollo con su variada etnología genética constitucional y hormonal así lo requieren
Comparison of Three-Dimensional in Situ Observations and Phase-Field Simulations of Microstructure Formation During Directional Solidification of Transparent Alloys Aboard the ISS
No abstract availabl
Lung myofibroblasts are characterized by down-regulated cyclooxygenase-2 and its main metabolite, prostaglandin E2.
Background: Prostaglandin E2 (PGE2), the main metabolite of cyclooxygenase (COX), is a well-known anti-fibrotic agent. Moreover, myofibroblasts expressing a-smooth muscle actin (a-SMA), fibroblast expansion and epithelial-mesenchymal transition (EMT) are critical to the pathogenesis of idiopathic pulmonary fibrosis (IPF). Our aim was to investigate the expression of COX-2 and PGE2 in human lung myofibroblasts and establish whether fibroblast-myofibroblast transition (FMT) and EMT are associated with COX-2 and PGE2 down-regulation. Methods: Fibroblasts obtained from IPF patients (n = 6) and patients undergoing spontaneous pneumothorax (control,n = 6) and alveolar epithelial cell line A549 were incubated with TGF-b1 and FMT and EMT markers were evaluated. COX-2 and a-SMA expression, PGE2 secretion and cell proliferation were measured after IL-1b and PGE2 incubation. Results: Myofibroblasts from both control and IPF fibroblast cultures stimulated with IL-1b showed no COX-2 expression. IPF fibroblasts showed increased myofibroblast population and reduced COX-2 expression in response to IL-1b. TGF-b1 increased the number of myofibroblasts in a time-dependent manner. In contrast, TGF-b1 induced slight COX-2 expression at 4 h (without increase in myofibroblasts) and 24 h, but not at 72 h. Both IPF and control cultures incubated with TGF-b1 for 72 h showed diminished COX-2 induction, PGE2 secretion and a-SMA expression after IL-1b addition. The latter decreased proliferation in fibroblasts but not in myofibroblasts. A549 cells incubated with TGF-b1 for 72 h showed downregulated COX-2 expression and low basal PGE2 secretion in response to IL-1b. Immuno-histochemical analysis of IPF lung tissue showed no COX-2 immuno-reactivity in myofibroblast foci. Conclusions: Myofibroblasts are associated with COX-2 down-regulation and reduced PGE2 production, which could be crucial in IPF development and progression
Polarization-based characterization of laser thermal treatment on biological tissue
The field of biomedical optics is promising in medical praxis. The study of laser thermal treatment and polarization-based characterization of tissue under it can be utilized in the correction of certain disorders with good results
Comparative study of nonlinear properties of EEG signals of a normal person and an epileptic patient
Background: Investigation of the functioning of the brain in living systems
has been a major effort amongst scientists and medical practitioners. Amongst
the various disorder of the brain, epilepsy has drawn the most attention
because this disorder can affect the quality of life of a person. In this paper
we have reinvestigated the EEGs for normal and epileptic patients using
surrogate analysis, probability distribution function and Hurst exponent.
Results: Using random shuffled surrogate analysis, we have obtained some of
the nonlinear features that was obtained by Andrzejak \textit{et al.} [Phys Rev
E 2001, 64:061907], for the epileptic patients during seizure. Probability
distribution function shows that the activity of an epileptic brain is
nongaussian in nature. Hurst exponent has been shown to be useful to
characterize a normal and an epileptic brain and it shows that the epileptic
brain is long term anticorrelated whereas, the normal brain is more or less
stochastic. Among all the techniques, used here, Hurst exponent is found very
useful for characterization different cases.
Conclusions: In this article, differences in characteristics for normal
subjects with eyes open and closed, epileptic subjects during seizure and
seizure free intervals have been shown mainly using Hurst exponent. The H shows
that the brain activity of a normal man is uncorrelated in nature whereas,
epileptic brain activity shows long range anticorrelation.Comment: Keywords:EEG, epilepsy, Correlation dimension, Surrogate analysis,
Hurst exponent. 9 page
Atualização da informação geológica e estratigráfica das jazidas de dinossáurios de La Rioja. Paleodiversidade do Cretácico Inferior do Grupo Enciso em Peña Cárcena (Igea, Espanha)
ABSTRACT: The discovery of new vertebrate fossil sites with skeletal remains in the Enciso Group of Igea (La Rioja) is showing the relevance of the area to study the palaeobiodiversity of Early Cretaceous vertebrate
faunas from the Iberian Peninsula. At Peña Cárcena hill two sedimentary environments have been inferred: a mixed siliciclastic-carbonate lacustrine environment that is dominant at the outcrops, overlaid by a splay delta in an avulsion-belt. The vertebrate remains are especially abundant in the mixed siliciclastic-carbonate lacustrine deposits with two partially articulated skeletons (a theropod and a large-sized dinosaur), teeth and a
fragment of a left maxilla of baryonychines, a pterosaur tooth that differs from those of Prejanopterus, a Goniopholis tooth, chelonian shell fragments that might belong to Camerochelys, a fairly complete lepisosteiform, teeth and dorsal fin spines of hybodontiforms. At the delta deposits, vertebrate fossils are rather scarce, with a single lepisosteiform skeleton and indeterminate bone fragments.RESUMO: A descoberta de novas jazidas com restos osteológicos de vertebrados no Grupo Enciso em Igea (La Rioja) comprova a importância da região para o estudo da paleobiodiversidade das faunas de vertebrados
do Cretácico Inferior da Península Ibérica. Na colina de Peña-Cárcena, tem-se inferido dois ambientes sedimentares: o predominante nos afloramentos corresponde a um ambiente lacustre, siliciclástico-carbonatado misto, que se encontra sobreposto por depósitos de transbordo deltaico em cinturão abandonado. Restos de vertebrados são abundantes nos depósitos lacustres, incluindo dois esqueletos parciais articulados (de um terópode e de outro dinossáurio de grande porte), dentes e um fragmento de maxila esquerda de barionicinos, um dente de pterossáurio distinto de Prejanopterus, um dente de Goniopholis, fragmentos da
carapaça de quelónios que poderão pertencer a Camerochelys, um lepisosteiforme praticamente completo, dentes e espinhos de barbatanas de hybodontiformes. Fósseis de vertebrados são escassos nos depósitos
deltaicos, com apenas um esqueleto de lepisosteiforme e fragmentos indeterminados.info:eu-repo/semantics/publishedVersio
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