2,042 research outputs found
Half a billion simulations: evolutionary algorithms and distributed computing for calibrating the SimpopLocal geographical model
Multi-agent geographical models integrate very large numbers of spatial
interactions. In order to validate those models large amount of computing is
necessary for their simulation and calibration. Here a new data processing
chain including an automated calibration procedure is experimented on a
computational grid using evolutionary algorithms. This is applied for the first
time to a geographical model designed to simulate the evolution of an early
urban settlement system. The method enables us to reduce the computing time and
provides robust results. Using this method, we identify several parameter
settings that minimise three objective functions that quantify how closely the
model results match a reference pattern. As the values of each parameter in
different settings are very close, this estimation considerably reduces the
initial possible domain of variation of the parameters. The model is thus a
useful tool for further multiple applications on empirical historical
situations
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Imaging the invisible—Bioorthogonal Raman probes for imaging of cells and tissues
A revolutionary avenue for vibrational imaging with super-multiplexing capability can be seen in the recent development of Raman-active bioortogonal tags or labels. These tags and isotopic labels represent groups of chemically inert and small modifications, which can be introduced to any biomolecule of interest and then supplied to single cells or entire organisms. Recent developments in the field of spontaneous Raman spectroscopy and stimulated Raman spectroscopy in combination with targeted imaging of biomolecules within living systems are the main focus of this review. After having introduced common strategies for bioorthogonal labeling, we present applications thereof for profiling of resistance patterns in bacterial cells, investigations of pharmaceutical drug-cell interactions in eukaryotic cells and cancer diagnosis in whole tissue samples. Ultimately, this approach proves to be a flexible and robust tool for in vivo imaging on several length scales and provides comparable information as fluorescence-based imaging without the need of bulky fluorescent tags. © 2020 The Authors. Journal of Biophotonics published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei
LITERATURA NA ESCOLA: DO VESTIBULAR AOS ENCONTROS DE FRUIÇÃO LEITORA
Este trabalho apresenta as ações realizadas em 2021 pelo Literatura e vestibular: encontros de fruição leitora, do IFC Camboriú, projeto de extensão que propõe o acesso e a mediação dos estudantes com as obras literárias das listas de leituras obrigatórias dos principais vestibulares da região, possibilitando experiências leitoras de fruição, reflexão, interpretação, análise e compartilhamento de textos literários no campus Camboriú. Nas práticas do projeto, a partir dos encontros com as obras literárias, os participantes pouderam ampliar suas conexões sensíveis e inteligíveis a partir de experiências de leitura capazes de suscitar relações diversas durante o processo de interação com os textos, promovendo discussões sobre os livros escolhidos para análise ao longo do ano e posteriormente compartilhados com a comunidade escolar e a sociedade em geral. Além da análise e divulgação de obras literárias, o projeto visa ao desenvolvimento da competência leitora, bem como à socialização do acesso às obras pertencentes ao cânone literário socialmente institucionalizado. Em 2021, foram lidas e analisadas obras de oito escritores nos encontros do projeto, que ocorreram por meio da plataforma virtual Google Meet
Nanoemulsion stability: experimental evaluation of the flocculation rate from turbidity measurements
The coalescence of liquid drops induces a higher level of complexity compared
to the classical studies about the aggregation of solid spheres. Yet, it is
commonly believed that most findings on solid dispersions are directly
applicable to liquid mixtures. Here, the state of the art in the evaluation of
the flocculation rate of these two systems is reviewed. Special emphasis is
made on the differences between suspensions and emulsions. In the case of
suspensions, the stability ratio is commonly evaluated from the initial slope
of the absorbance as a function of time under diffusive and reactive
conditions. Puertas and de las Nieves (1997) developed a theoretical approach
that allows the determination of the flocculation rate from the variation of
the turbidity of a sample as a function of time. Here, suitable modifications
of the experimental procedure and the referred theoretical approach are
implemented in order to calculate the values of the stability ratio and the
flocculation rate corresponding to a dodecane-in-water nanoemulsion stabilized
with sodium dodecyl sulfate. Four analytical expressions of the turbidity are
tested, basically differing in the optical cross section of the aggregates
formed. The first two models consider the processes of: a) aggregation (as
described by Smoluchowski) and b) the instantaneous coalescence upon
flocculation. The other two models account for the simultaneous occurrence of
flocculation and coalescence. The latter reproduce the temporal variation of
the turbidity in all cases studied (380 \leq [NaCl] \leq 600 mM), providing a
method of appraisal of the flocculation rate in nanoemulsions
: Recueil de fiches pédagogiques du réseau MAPS
DoctoralLe réseau thématique MAPS «Modélisation multi-Agent appliquée aux Phénomènes Spatialisés » propose depuis 2009 des évènements scientifiques ayant pour but de diffuser les pratiques de modélisations multi-agents au sein des Sciences de l’Homme et de la Société (SHS). Ce collectif pluridisciplinaire de chercheurs, d’enseignants-chercheurs et de doctorants est labellisé en tant que ≪ réseau thématique » par le Réseau National des Systèmes Complexes (GIS RNSC) et bénéficie du soutien du CNRS au titre de la Formation Permanente. Depuis 2009, plusieurs modèles ont été développés au cours d'événements MAPS. Ces modèles ont fait l'objet de fiches pédagogiques détaillées destinées aux communautés éducatives et universitaires et en particulier aux enseignants qui souhaiteraient faire découvrir la modélisation à leurs étudiants, mais aussi à ceux qui envisagent d’approfondir certains aspects avec un public plus averti. Elles sont également destinées à tous les curieux qui souhaiteraient découvrir ce que la modélisation apporte aux SHS, du point de vue heuristique et du point de vue opérationnel. Enfin, elles sont aussi des supports pour toutes les personnes qui souhaiteraient diffuser les réflexions scientifiques sur la modélisation et la simulation qui ont présidé à la rédaction de ces fiches
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