Página 5 dos resultados de 9995 itens digitais encontrados em 1.282 segundos

‣ Generalized Birnbaum-Saunders distributions applied to air pollutant concentration

LEIVA, Victor; BARROS, Michelli; PAULA, Gilberto A.; SANHUEZA, Antonio
Fonte: JOHN WILEY & SONS LTD Publicador: JOHN WILEY & SONS LTD
Tipo: Artigo de Revista Científica
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The generalized Birnbaum-Saunders (GBS) distribution is a new class of positively skewed models with lighter and heavier tails than the traditional Birnbaum-Saunders (BS) distribution, which is largely applied to study lifetimes. However, the theoretical argument and the interesting properties of the GBS model have made its application possible beyond the lifetime analysis. The aim of this paper is to present the GBS distribution as a useful model for describing pollution data and deriving its positive and negative moments. Based on these moments, we develop estimation and goodness-of-fit methods. Also, some properties of the proposed estimators useful for developing asymptotic inference are presented. Finally, an application with real data from Environmental Sciences is given to illustrate the methodology developed. This example shows that the empirical fit of the GBS distribution to the data is very good. Thus, the GBS model is appropriate for describing air pollutant concentration data, which produces better results than the lognormal model when the administrative target is determined for abating air pollution. Copyright (c) 2007 John Wiley & Sons, Ltd.

‣ Similarity in school textbooks on natural sciences for the primary school level : an analysis of teaching and apprenticeship of botany in the last century in Portugal (1900-2000)

Guimarães, Fernando
Fonte: International Association of Technology, Education and Development Publicador: International Association of Technology, Education and Development
Tipo: Artigo de Revista Científica
Publicado em /11/2009 Português
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By analyzing school textbooks, we evidenced that Botany contents used for the teaching of Sciences cannot be isolated from both educational and curricular policies adopted in Portugal during the 20th century. Within schools, textbooks are important tools to conform shapes and contents applied in the pedagogical knowledge. The articulation of aspects related to the sequence and pace of knowledge transmission has momentous pedagogical and didactic objectives, which are made possible through properly devised activities and evaluation mechanisms for such acquisitions. With this perspective in mind, such objectives can allow us to know the subjacent pedagogical and curricular ideology, as well as the way through which the learning and apprenticeship process is understood. Such process takes place within classrooms and plays an important role for teachers and students. The present study, based upon the PhD thesis on Children Studies (Botany within school textbooks for Primary and Basic teaching levels [1st cycle] in the 20th century in Portugal), aims to analyze the importance Botany is given in Portugal in school textbooks that cover Natural Sciences for Primary School students in the last century. Our attempt to know how botanical topics were differently adopted throughout time in the school textbooks relied on 11 principles: Shape; Kingdoms; Classification; Organs; Root; Stem; Leaf; Flower; Fruit; Reproduction; and Dimension. Such appreciation...

‣ Extrafloral nectar production of the ant-associated plant, Macaranga tanarius, is an induced, indirect, defensive response elicited by jasmonic acid

Heil, Martin; Koch, Thomas; Hilpert, Andrea; Fiala, Brigitte; Boland, Wilhelm; Linsenmair, K. Eduard
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
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Plant species in at least 66 families produce extrafloral nectar (EFN) on their leaves or shoots and therewith attract predators and parasitoids, such as ants and wasps, which in turn defend them against herbivores. We investigated whether EFN secretion is induced by herbivory and/or artificial damage, and thus can be regarded as an induced defensive response. In addition, we studied the underlying signaling pathway. EFN secretion by field-grown Macaranga tanarius increased after herbivory, artificial leaf damage, and exogenous jasmonic acid (JA) application. Artificial damage strongly enhanced endogenous JA concentrations. The response in EFN production to artificial damage was much less pronounced in those leaves that were treated with phenidone to inhibit endogenous JA synthesis. Quantitative dose–response relations were found between the increase in nectar production and both the intensity of leaf damage and the amounts of exogenously applied JA. The amount of endogenously produced JA was positively correlated with the intensity of leaf damage. Increased numbers of defending insects and decreased numbers of herbivores were observed on leaves after inducing EFN production by exogenous JA treatment. Over 6 weeks...

‣ Synergy between an antiangiogenic integrin αv antagonist and an antibody–cytokine fusion protein eradicates spontaneous tumor metastases

Lode, Holger N.; Moehler, Thomas; Xiang, Rong; Jonczyk, Alfred; Gillies, Stephen D.; Cheresh, David A.; Reisfeld, Ralph A.
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
Publicado em 16/02/1999 Português
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The suppression and eradication of primary tumors and distant metastases is a major goal of alternative treatment strategies for cancer, such as inhibition of angiogenesis and targeted immunotherapy. We report here a synergy between two novel monotherapies directed against vascular and tumor compartments, respectively, a tumor vasculature-specific antiangiogenic integrin αv antagonist and tumor-specific antibody–interleukin 2 (IL-2) fusion proteins. Simultaneous and sequential combination of these monotherapies effectively eradicated spontaneous liver metastases in a poorly immunogenic syngeneic model of neuroblastoma. This was in contrast to controls subjected to monotherapies with either an antiangiogenic integrin αv antagonist or antibody–IL-2 fusion proteins, which were only partially effective at the dose levels applied. Furthermore, simultaneous treatments with the integrin αv antagonist and tumor-specific antibody–IL-2 fusion proteins induced dramatic primary tumor regressions in three syngeneic murine tumor models, i.e., melanoma, colon carcinoma, and neuroblastoma. However, each agent used as monotherapy induced only a delay in tumor growth. A mechanism for this synergism was suggested because the antitumor response was accompanied by a simultaneous 50% reduction in tumor vessel density and a 5-fold increase in inflammatory cells in the tumor microenvironment. Subsequently...

‣ The protease thrombin is an endogenous mediator of hippocampal neuroprotection against ischemia at low concentrations but causes degeneration at high concentrations

Striggow, Frank; Riek, Monika; Breder, Jörg; Henrich-Noack, Petra; Reymann, Klaus G.; Reiser, Georg
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
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We have considered the extracellular serine protease thrombin and its receptor as endogenous mediators of neuronal protection against brain ischemia. Exposure of gerbils to prior mild ischemic insults, here two relatively short-lasting occlusions (2 min) of both common carotid arteries applied at 1-day intervals 2 days before a severe occlusion (6 min), caused a robust ischemic tolerance of hippocampal CA1 neurons. This resistance was impaired if the specific thrombin inhibitor hirudin was injected intracerebroventricularly before each short-lasting insult. Thus, efficient native neuroprotective mechanisms exist and endogenous thrombin seems to be involved therein. In vitro experiments using organotypic slice cultures of rat hippocampus revealed that thrombin can have protective but also deleterious effects on hippocampal CA1 neurons. Low concentrations of thrombin (50 pM, 0.01 unit/ml) or of a synthetic thrombin receptor agonist (10 μM) induced significant neuroprotection against experimental ischemia. In contrast, 50 nM (10 units/ml) thrombin decreased further the reduced neuronal survival that follows the deprivation of oxygen and glucose, and 500 nM even caused neuronal cell death by itself. Degenerative thrombin actions also might be relevant in vivo...

‣ Scan statistics to scan markers for susceptibility genes

Hoh, J.; Ott, J.
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
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Scan statistics are applied to combine information on multiple contiguous genetic markers used in a genome screen for susceptibility loci. This information may be, for example, allele sharing proportions for sib pairs or logarithm of odds (lod) scores in general small families. We focus on a dichotomous outcome variable, for example, case and control individuals or affected-affected versus affected-unaffected siblings, and suitable single-marker statistics. A significant scan statistic based on the single-marker statistics represents evidence of the presence of a susceptibility gene. For a given length of the scan statistic, we assess its significance by Monte Carlo permutation tests. Comparing P values for varying lengths of scan statistics, we treat the smallest observed P value as our statistic of interest and determine its overall significance level. We applied this method to a genome screen with autism families. The result was informative and surprising: A susceptibility region was found (genome-wide significance level, P = 0.038), which is missed with conventional approaches.

‣ A novel function for serotonin-mediated short-term facilitation in Aplysia: Conversion of a transient, cell-wide homosynaptic Hebbian plasticity into a persistent, protein synthesis-independent synapse-specific enhancement

Bailey, Craig H.; Giustetto, Maurizio; Zhu, Hiuxiang; Chen, Mary; Kandel, Eric R.
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
Publicado em 10/10/2000 Português
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Studies of sensitization and classical conditioning of the gill-withdrawal reflex in Aplysia have shown that the synaptic connections between identified glutamatergic sensory neurons and motor neurons can be enhanced in one of two ways: by a heterosynaptic (modulatory input-dependent) mechanism that gives rise with repetition to long-term facilitation and by a homosynaptic (activity-dependent) mechanism that gives rise with repetition to a facilitation that is partially blocked by 2-amino-5-phosphonovaleric acid and by injection of 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetate (BAPTA) into the postsynaptic cell and is similar to long-term potentiation in the hippocampus. We here have examined how these two forms of facilitation interact at the level of an individual synaptic connection by using a culture preparation consisting of a single bifurcated sensory neuron that forms independent synaptic contacts with each of two spatially separated motor neurons. We find that the homosynaptic facilitation produced by a train of action potentials is cell wide and is evident at all of the terminals of the sensory neuron. By contrast, the heterosynaptic facilitation mediated by the modulatory transmitter serotonin (5-HT) can operate at the level of a single synapse. Homosynaptic activation gives rise to only a transient facilitation lasting a few hours...

‣ Cell-free tumor antigen peptide-based cancer vaccines

Schmidt, Walter; Buschle, Michael; Zauner, Wolfgang; Kirlappos, Helen; Mechtler, Karl; Trska, Barbara; Birnstiel, Max L.
Fonte: The National Academy of Sciences of the USA Publicador: The National Academy of Sciences of the USA
Tipo: Artigo de Revista Científica
Publicado em 01/04/1997 Português
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The central role that tumor antigen-derived peptides play in induction of antitumor immunity makes them ideal candidates for peptide-based cancer vaccines. We have demonstrated that “transloading” is an efficient strategy for importing short peptide ligands into antigen-presenting cells in vitro. Postulating that the transloading procedure might effect peptide uptake by antigen-presenting cells in vivo as well, we tested this approach for the generation of peptide-based cancer vaccines. In the P815 mastocytoma system, we vaccinated mice by s.c. injection of a single, known natural peptide derived from JAK-1 kinase. Whereas vaccination with peptide alone or mixed with incomplete Freund’s adjuvant was ineffective, application of the peptide in conjunction with the polycation poly-l-lysine protected a significant number of animals against tumor challenge. Dependent upon the type of poly-l-lysine applied, protection against tumor take was comparable to that achieved with irradiated whole-cell vaccines, genetically modified to secrete granulocyte–macrophage colony-stimulating factor. In the murine melanoma M-3, a combination of four putative tumor antigen-derived peptides was tested as a cancer vaccine. Administered in combination with polycations...

‣ A method for high-sensitivity peptide sequencing using postsource decay matrix-assisted laser desorption ionization mass spectrometry

Keough, T.; Youngquist, R. S.; Lacey, M. P.
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
Publicado em 22/06/1999 Português
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A method has been developed for de novo peptide sequencing using matrix-assisted laser desorption ionization mass spectrometry. This method will facilitate biological studies that require rapid determination of peptide or protein sequences, e.g., determination of posttranslational modifications, identification of active compounds isolated from combinatorial peptide libraries, and the selective identification of proteins as part of proteome studies. The method involves fast, one-step addition of a sulfonic acid group to the N terminus of tryptic peptides followed by acquisition of postsource decay (PSD) fragment ion spectra. The derivatives are designed to promote efficient charge site-initiated fragmentation of the backbone amide bonds and to selectively enhance the detection of a single fragment ion series that contains the C terminus of the molecule (y-ions). The overall method has been applied to pmol quantities of peptides. The resulting PSD fragment ion spectra often exhibit uninterrupted sequences of 20 or more amino acid residues. However, fragmentation efficiency decreases considerably at amide bonds on the C-terminal side of Pro. The spectra are simple enough that de novo sequence tagging is routine. The technique has been successfully applied to peptide mixtures...

‣ Force-mediated kinetics of single P-selectin/ligand complexes observed by atomic force microscopy

Fritz, Jürgen; Katopodis, Andreas G.; Kolbinger, Frank; Anselmetti, Dario
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
Publicado em 13/10/1998 Português
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Leukocytes roll along the endothelium of postcapillary venules in response to inflammatory signals. Rolling under the hydrodynamic drag forces of blood flow is mediated by the interaction between selectins and their ligands across the leukocyte and endothelial cell surfaces. Here we present force-spectroscopy experiments on single complexes of P-selectin and P-selectin glycoprotein ligand-1 by atomic force microscopy to determine the intrinsic molecular properties of this dynamic adhesion process. By modeling intermolecular and intramolecular forces as well as the adhesion probability in atomic force microscopy experiments we gain information on rupture forces, elasticity, and kinetics of the P-selectin/P-selectin glycoprotein ligand-1 interaction. The complexes are able to withstand forces up to 165 pN and show a chain-like elasticity with a molecular spring constant of 5.3 pN nm−1 and a persistence length of 0.35 nm. The dissociation constant (off-rate) varies over three orders of magnitude from 0.02 s−1 under zero force up to 15 s−1 under external applied forces. Rupture force and lifetime of the complexes are not constant, but directly depend on the applied force per unit time, which is a product of the intrinsic molecular elasticity and the external pulling velocity. The high strength of binding combined with force-dependent rate constants and high molecular elasticity are tailored to support physiological leukocyte rolling.

‣ PESS eZine vol 4 October 2014

Sohun, Rhoda; Kenny, Ian
Fonte: Department of Physical Education and Sport Sciences, University of Limerick Publicador: Department of Physical Education and Sport Sciences, University of Limerick
Tipo: info:eu-repo/semantics/report; all_ul_research
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non-peer-reviewed; On behalf of PESS I would like to welcome you to the fourth edition of the online magazine Physical Education and Sport Sciences e-Zine. Further staffing changes have occurred since the last edition of the e-Zine and I would like to take this opportunity to welcome Gary Ryan (Physical Activity Health Lifestyle and Sports (PAHLS) Project Manager), Dr. Matthew Herring (Lecturer in Exercise Psychology) and Ursula McCarthy (Applied Studies Coordinator). David Kelly, Grainne Hayes and Caoimhe Tiernan are welcomed to the Department as Teaching Assistants and Michelle Dillon returns to PESS for a 11-month appointment. The Department is particularly proud to acknowledge that Drs. Brian Carson, Mark Campbell and Mark Lyons were successful in the most recent round of progression. I would like to take this opportunity to draw your attention to the article in this edition of the e-Zine that pays tribute to Professor Pat Duffy. A number of colleagues in the field of physical education, sport and coaching are still struggling with the untimely passing of Pat whose vision, energy and continual hopes for Irish physical education, sport and physical activity provision were unfaultering throughout the years. Again...

‣ Improved Understanding of Apoptosis and Metabolism in Chinese Hamster Ovary Cell Culture

Sun, Ruiqiang
Fonte: Universidade Rice Publicador: Universidade Rice
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Mammalian cell culture has gained importance in biotechnology for the development of therapeutic and diagnostic agents. Among them, Chinese hamster ovary (CHO) cells are regarded as the mammalian cell "workhorse". The use of CHO cell line for the production of recombinant proteins used in human therapy has reached a level of industrial production. However, a major problem encountered in in vitro cultures is cell death via apoptosis. Since apoptosis leads to the loss of viability of mammalian cells in vitro, especially in serum-free media. This is important and necessary to prevent the activation of apoptosis cascade and increase their cell viability and enhance their cellular robustness. The overall goal of this study is to improve our understanding of the cellular and physiological determinants of apoptosis and its relationship with other cellular functions. Apoptosis is a result of a very complex network of signaling pathways triggered from both inside and outside of the cell and a highly regulated pathway by both pro-apoptotic and anti-apoptotic proteins that promote cell survival or cell death. Although many causes of apoptotic process in mammalian cell cultures had been researched in the past and have been discussed in recent years...

‣ Interactive visualization tools for topological exploration

Heng, Pheng Ann
Fonte: [Bloomington, Ind.] : Indiana University Publicador: [Bloomington, Ind.] : Indiana University
Tipo: Doctoral Dissertation
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Thesis (Ph.D.) - Indiana University, Computer Science, 1992; This thesis concerns using computer graphics methods to visualize mathematical objects. Abstract mathematical concepts are extremely difficult to visualize, particularly when higher dimensions are involved; I therefore concentrate on subject areas such as the topology and geometry of four dimensions which provide a very challenging domain for visualization techniques. In the first stage of this research, I applied existing three-dimensional computer graphics techniques to visualize projected four-dimensional mathematical objects in an interactive manner. I carried out experiments with direct object manipulation and constraint-based interaction and implemented tools for visualizing mathematical transformations. As an application, I applied these techniques to visualizing the conjecture known as Fermat's Last Theorem. Four-dimensional objects would best be perceived through four-dimensional eyes. Even though we do not have four-dimensional eyes, we can use computer graphics techniques to simulate the effect of a virtual four-dimensional camera viewing a scene where four-dimensional objects are being illuminated by four-dimensional light sources. I extended standard three-dimensional lighting and shading methods to work in the fourth dimension. This involved replacing the standard "z-buffer" algorithm by a "w-buffer" algorithm for handling occlusion...

‣ A Multiscale Model of the Enhanced Heat Transfer in a CNT-Nanofluid System

Lee, Jonathan Winnie
Fonte: Universidade Rice Publicador: Universidade Rice
Tipo: Thesis; Text Formato: 168 p.; application/pdf
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Over the last decade, much research has been done to understand the role of nanoparticles in heat transfer fluids. While experimental results have shown "anomalous" thermal enhancements and non-linear behavior with respect to CNT loading percentage, little has been done to replicate this behavior from an analytical or computational standpoint. This study is aimed towards using molecular dynamics to augment our understanding of the physics at play in CNT-nanofluid systems. This research begins with a heat transfer study of individual CNTs in a vacuum environment. Temperature gradients are imposed or induced via various methods. Tersoff and AIREBO potentials are used for the carbon-carbon interactions in the CNTs. Various chirality CNTs are explored, along with several different lengths and temperatures. The simulations have shown clear dependencies upon CNT length, CNT chirality, and temperature. Subsequent studies simulate individual CNTs solvated in a simple fluidic box domain. A heat flux is applied to the domain, and various tools are employed to study the resulting heat transfer. The results from these simulations are contrasted against the earlier control simulations of the CNT-only domain. The degree by which the solvation dampens the effect of physical parameters is discussed. Effective thermal conductivity values are computed...

‣ Modélisation procédurale de mondes virtuels par pavage d'occultation

Gomez, Dorian
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
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Cette thèse porte sur la modélisation procédurale de mondes virtuels étendus dans le domaine de l’informatique graphique. Nous proposons d’exploiter les propriétés de visibilité entre régions élémentaires de la scène, que nous appelons tuiles, pour contrôler sa construction par pavage rectangulaire. Deux objectifs distincts sont visés par nos travaux : (1) fournir aux infographistes un moyen efficace pour générer du contenu 3D pour ces scènes virtuelles de très grande taille, et (2) garantir, dès la création du monde, des performances de rendu et de visualisation efficace. Pour cela, nous proposons plusieurs méthodes de détermination de la visibilité en 2D et en 3D. Ces méthodes permettent l’évaluation d’ensembles potentiellement visibles (PVS) en temps interactif ou en temps réel. Elles sont basées sur les calculs de lignes séparatrices et de lignes de support des objets, mais aussi sur l’organisation hiérarchique des objets associés aux tuiles. La première technique (2D) garantit l’occultation complète du champ visuel à partir d’une distance fixe, spécifiée par le concepteur de la scène, depuis n’importe quel endroit sur le pavage. La seconde permet d’estimer et de localiser les tuiles où se propage la visibilité...

‣ Cyclic Strain Induces Dual-Mode Endothelial-Mesenchymal Transformation of the Cardiac Valve

Balachandran, Kartik; Alford, Patrick W.; Wylie-Sears, Jill; Goss, Josue; Grosberg, Anna; Bischoff, Joyce E.; Aikawa, Elena; Levine, Robert A.; Parker, Kevin Kit
Fonte: Proceedings of the National Academy of Sciences Publicador: Proceedings of the National Academy of Sciences
Tipo: Artigo de Revista Científica
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Endothelial-mesenchymal transformation (EMT) is a critical event for the embryonic morphogenesis of cardiac valves. Inducers of EMT during valvulogenesis include VEGF, TGF-β1, and wnt/β-catenin (where wnt refers to the wingless-type mammary tumor virus integration site family of proteins), that are regulated in a spatiotemporal manner. EMT has also been observed in diseased, strain-overloaded valve leaflets, suggesting a regulatory role for mechanical strain. Although the preponderance of studies have focused on the role of soluble mitogens, we asked if the valve tissue microenvironment contributed to EMT. To recapitulate these microenvironments in a controlled, in vitro environment, we engineered 2D valve endothelium from sheep valve endothelial cells, using microcontact printing to mimic the regions of isotropy and anisotropy of the leaflet, and applied cyclic mechanical strain in an attempt to induce EMT. We measured EMT in response to both low (10%) and high strain (20%), where low-strain EMT occurred via increased TGF-β1 signaling and high strain via increased wnt/β-catenin signaling, suggesting dual strain-dependent routes to distinguish EMT in healthy versus diseased valve tissue. The effect was also directionally dependent...

‣ Reorganization of the cochleotopic map in the bat's auditory system by inhibition

Xiao, Zhongju; Suga, Nobuo
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
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The central auditory system of the mustached bat shows two types of reorganization of cochleotopic (frequency) maps: expanded reorganization resulting from shifts in the best frequencies (BFs) of neurons toward the BF of repetitively stimulated cortical neurons (hereafter centripetal BF shifts) and compressed reorganization resulting from the BF shifts of neurons away from the BF of the stimulated cortical neurons (hereafter centrifugal BF shifts). Facilitation and inhibition evoked by the corticofugal system have been hypothesized to be respectively related to centripetal and centrifugal BF shifts. If this hypothesis is correct, bicuculline (an antagonist of inhibitory GABA-A receptors) applied to cortical neurons would change centrifugal BF shifts into centripetal BF shifts. In the mustached bat, electric stimulation of cortical Doppler-shifted constant-frequency neurons, which are highly specialized for frequency analysis, evokes the centrifugal BF shifts of ipsilateral collicular and cortical Doppler-shifted constant-frequency neurons and contralateral cochlear hair cells. Bicuculline applied to the stimulation site changed the centrifugal BF shifts into centripetal BF shifts. On the other hand, electric stimulation of neurons in the posterior division of the auditory cortex...

‣ The Renormalization-Group Method Applied to Asymptotic Analysis of Vector Fields

Kunihiro, Teiji
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 05/09/1996 Português
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The renormalization group method of Goldenfeld, Oono and their collaborators is applied to asymptotic analysis of vector fields. The method is formulated on the basis of the theory of envelopes, as was done for scalar fields. This formulation actually completes the discussion of the previous work for scalar equations. It is shown in a generic way that the method applied to equations with a bifurcation leads to the Landau-Stuart and the (time-dependent) Ginzburg-Landau equations. It is confirmed that this method is actually a powerful theory for the reduction of the dynamics as the reductive perturbation method is. Some examples for ordinary diferential equations, such as the forced Duffing, the Lotka-Volterra and the Lorenz equations, are worked out in this method: The time evolution of the solution of the Lotka-Volterra equation is explicitly given, while the center manifolds of the Lorenz equation are constructed in a simple way in the RG method.; Comment: The revised version of RYUTHP 96/1. Submitted to Prog. Theor. Phys. (Kyoto) in Feb., 1996. 28 pages. LATEX. No figures

‣ Advances in analytical and applied pyrolysis 2006-2008; Book of Abstracts of the Communications Presented to the 18th International Symposium on Analytical and Applied Pyrolysis

González-Pérez, José Antonio; González-Vila, Francisco Javier
Fonte: CSIC - Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS) Publicador: CSIC - Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS)
Tipo: Libro Formato: 4443563 bytes; application/pdf
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1 Vol with 256 communicatons to PYR08 in 330 pages.-- 18th International Symposium on Analytical and Applied Pyrolysis held in Lanzarote - Canary Islands, Spain.-- May 18-23, 2008.; Every other year, a group of scientists organizes this International Meeting that is among the most prestigious conference in the field. We are expecting that PYR08 in Lanzarote will continue the tradition as the premier forum for the presentation and discussion of cutting-edge scientific advances in basic and applied pyrolysis, setting the trend for the development of this discipline. This edition of the Symposium has exceptional exposure in fields like novel applications of pyrolysis in the environment and forensic sciences, the search for new materials, polymers, alternative energy source and in the structural elucidation of complex organic materials that may help in a better comprehension of the carbon cycle and Global Climatic Change. More than 200 top scientists and industry professionals from more that 30 countries from all over the world will attend PYR08. This edition has a very intense programme that include 10 Invited Key Lectures, 66 Oral and 180 Poster presentations.; Ministerio de Ciencia e Innovación (MICINN) Consejo Superior de Investigaciones Científicas (CSIC) Gobierno de Canarias Cabildo Insular de Lanzarote Universidad de las Palmas de Gran Canaria (ULPGC) Universidad de la Laguna (ULL) Ayuntamiento de Teguise Centros de Arte...

‣ The Construction of a Broader Conception on the Nature of Sciences at a 9th Grade Class: a Case Study; A Construção de uma Concepção Mais Ampla sobre a Natureza das Ciências em uma Turma do 9º ano: Um Estudo de Caso

Roberto Dalmo V. L de Oliveira; Universidade Federal do Tocantins; Lucidéa G. R. Coutinho; Universidade Federal Fluminense; Maura V. Chinelli; Universidade Federal Fluminense; Glória Regina C. P. Queiroz; Universidade do Estado do Rio de Janeiro
Fonte: Revista Virtual de Química Publicador: Revista Virtual de Química
Tipo: ; Formato: binary/octet-stream
Publicado em 27/05/2015 Português
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It is relevant for the teaching of Sciences that students understand Science as a historical, human activity associated to aspects of social, economic, political and cultural nature. This work is the result of a pedagogical proposition applied to 9th grade students at a private school in the state of Rio de Janeiro in which it was chosen a thematic approach of the chemistry and physics contents proposed and their elaboration based on three well known fields of research on the Teaching of Sciences; Science, Technology and Society (STS), History of Science and Science and Art. Hence through a case study on a 9thgrade class we tried to understand the possibilities of stimulating the broader perceptions on the Nature of Sciences (NoS). DOI: 10.5935/1984-6835.20150048; É relevante ao Ensino de Ciências que os estudantes compreendam a Ciência como uma atividade humana, histórica, associada a aspectos de ordem social, econômica, política e cultural. Este trabalho é fruto de proposta pedagógica aplicada a estudantes do 9º ano do Ensino Fundamental de um Colégio da rede particular de ensino, localizado no estado do Rio de Janeiro, no qual foi decidido pela abordagem temática dos conteúdos químicos e físicos propostos e sua elaboração baseada em três campos...