308 research outputs found
Evolutionary algorithms for static and dynamic optimization of fed-batch fermentation processes
In this work, Evolutionary Algorithms (EAs) are used to control a recombinant bacterial fed-batch fermentation process, that aims at producing a bio-pharmaceutical product. In a first stage, a novel EA is used to optimize
the process, prior to its start, by simultaneously adjusting the feeding trajectory, the duration of the fermentation
and the initial conditions of the process. In a second stage, dynamic optimization is proposed, where the EA is running simultaneously with the fermentation process,
receiving information regarding from the process, updating its internal model, reaching new solutions that will be used for online control
Diet of mid-Atlantic Sowerby’s beaked whales Mesoplodon bidens
Copyright © 2011 Elsevier Ltd. All rights reserved.The first mid-Atlantic diet of Mesoplodon beaked whales is presented, from ten Sowerby's Mesoplodon bidens stranded in the Azores region between 2002 and 2009. This doubles the worldwide number of stomachs sampled, and reveals new feeding habits for this species. The mean number of prey items per stomach was 85±89 (range: 12–238), with fish accounting for 99.3% and cephalopods contributing less than 1% of total prey. Fish otoliths from 15 families and cephalopod lower mandibles from three families were identified, representing 22 taxa. The diet consisted mainly of small mid-water fish, the most numerous being Diaphus sp., Lampanyctus sp. and Melamphaidae species. Myctophids were present in all stranded individuals, followed by Diretmidae, Melamphaidae and Opisthoproctus soleatus, while the remaining fish species were scarce or single occurrences. Consistency of diet in four different years reveals a divergence from all previous records in continental areas, where mainly neritic and shelf-break benthopelagic fish species have been reported. Mid-Atlantic Sowerby's beaked whales' showed dietary plasticity, feeding on the most abundant mid-water groups occurring between 0 and750 m. Trophic level from prey numerical frequency was estimated at 4.4±0.46
Biocompatible hybrids based on nanographene oxide covalently linked to glycolporphyrins: synthesis, characterization and biological evaluation
The major limitation in the development of hybrids based on graphene oxide (GO) and porphyrins is their dispersibility and stability in aqueous systems due to the hydrophobic character induced by porphyrins. Most of the previous approaches reported the direct functionalization of GO with polyethylene glycol (PEG) chains followed by the self-assembly of porphyrins by π-π interactions. Here, new hybrids were prepared using porphyrins previously functionalized with different number/types of glycol branches to be covalently attached through esterification to the carboxyl groups of GO sheets of nanometric dimensions. The number of the glycol chains and its relative position in the porphyrin core showed to be fundamental to improve the hybrids dispersion and stability in aqueous solutions. The best performing hybrids were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared, UV-Vis absorption and fluorescence spectroscopy. The in vitro biocompatibility assessment of these hybrids was conducted using human Saos-2 cells. Their effects on cell proliferation and viability, the generation of reactive oxygen species as well as the cell morphology after cell uptake were analysed. The results demonstrate the biocompatibility of these hybrid nanomaterials with human Saos-2 cells, which is very promising for future application in biomedicine namely in cancer therapy.publishe
The OBAA Standard for Developing Repositories of Learning Objects: the Case of Ocean Literacy in Azores
This paper describes the existing web resources of learning objects to promote ocean
literacy. The several projects and sites are explored, and the shortcomings revealed. The
limitations identified include insufficient metadata about registered learning objects and
lack of support for intelligent applications. As solution, we promote the seaThings project
that relies on a multi-disciplinary approach to promote literacy in the marine environment
by implementing a specific Learning Objects repositories (LOR) and a federation of
repositories (FED), supported by a OBAA, a versatile and innovative standard that will
provide the necessary support for intelligent applications for education purposes, to be used
in schools and other educational institutions.info:eu-repo/semantics/publishedVersio
Environmental Groundwater Vulnerability Assessment in Urban Water Mines
A multidisciplinary approach was developed to estimate urban groundwater vulnerability
to contamination combining hydrogeology, hydrogeochemistry, subterranean hydrogeotechnics,
groundwater ecotoxicology and isotope tracers. Paranhos and Salgueiros spring waters in Porto City
were used as a case study. Historical and current vulnerability scenarios were compared using
hydrogeological GIS-based modelling. Potential contamination sources were mapped around the
spring galleries. Most of these were point sources and their potential contamination load was
moderate. The ecotoxicological assessment indicated a low acute toxicity potential. Groundwater
radionuclides appeared to be mainly controlled by geological factors and biomineralisation.
Vulnerability maps suggest that most of the area has a moderate to low vulnerability to contamination.
However, some surface sources such as sewage systems cause contamination and contribute to
increased vulnerability. This integrated approach was demonstrated to be adequate for a better
knowledge of urban hydrogeological processes and their dynamics, and highlighted the importance
of a vulnerability assessment in urban areas.info:eu-repo/semantics/publishedVersio
A dynamic default revision mechanism for speculative computation
In this work a default revision mechanism is introduced into Speculative
Computation to manage incomplete information. The default revision
is supported by a method for the generation of default constraints based on
Bayesian Networks. The method enables the generation of an initial set of
defaults which is used to produce the most likely scenarios during the computation,
represented by active processes. As facts arrive, the Bayesian Network
is used to derive new defaults. The objective with such a new dynamic mechanism
is to keep the active processes coherent with arrived facts. This is achieved
by changing the initial set of default constraints during the reasoning process
in Speculative Computation. A practical example in clinical decision support
is described.info:eu-repo/semantics/publishedVersio
Recomendación de fertilizantes para Pinus y Eucalyptus en Corrientes, Argentina utilizando balance nutricional
â– Alcanzar metas de productividad deseadas en bosques implantados requiere suministrarleslas cantidades de nutrientes que estos demandan.â– La calibración de modelos de balance nutricional para especies forestales plantadas enArgentina es una alternativa promisora para recomendar fertilizantes con un fundamentomás cientÃfico y menos empÃrico.â– Estos modelos permiten entender cuando es preciso fertilizar y con qué dosis según cadasituación en busca de optimizar el uso de recursos y mantener la sustentabilidad de laproducción forestal.Fil: Stahringer, Nicolas I.. Universidade Federal de Viçosa.; BrasilFil: Neves, Julio C. L.. Universidade Federal de Viçosa.; BrasilFil: Paulucio, R. B.. Universidade Federal de Viçosa.; BrasilFil: Teixeira, José L.. Universidade Federal de Viçosa.; BrasilFil: Sussini, Paolo Adrián. Instituto Nacional de TecnologÃa Agropecuaria. Centro Regional Chaco-Formosa. Estación Experimental Agropecuaria Colonia BenÃtez; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Nordeste; ArgentinaFil: Argüelles, R. T.. Universidad Nacional del Sur. Departamento de AgronomÃa; ArgentinaFil: Chamorro, Luis Leandro. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentin
Adenosine A2A receptor modulation of hippocampal CA3-CA1 synapse plasticity during associative learning in behaving mice
© 2009 Nature Publishing Group All rights reservedPrevious in vitro studies have characterized the electrophysiological and molecular signaling pathways of adenosine tonic modulation on long-lasting synaptic plasticity events, particularly for hippocampal long-term potentiation(LTP). However, it remains to be elucidated
whether the long-term changes produced by endogenous adenosine in the efficiency of synapses are related to those required for
learning and memory formation. Our goal was to understand how endogenous activation of adenosine excitatory A2A receptors modulates the associative learning evolution in conscious behaving mice. We have studied here the effects of the application of a highly selective A2A receptor antagonist, SCH58261, upon a well-known associative learning paradigm - classical eyeblink conditioning. We used a trace paradigm, with a tone as the conditioned stimulus (CS) and an electric shock presented to the supraorbital nerve as the unconditioned stimulus(US). A single electrical pulse was presented to the Schaffer collateral–commissural pathway to evoke field EPSPs (fEPSPs) in the pyramidal CA1 area during the CS–US interval. In vehicle-injected animals, there was a progressive increase in the percentage of conditioning responses (CRs) and in the slope of fEPSPs through conditioning sessions, an effect that was completely prevented (and lost) in SCH58261 (0.5 mg/kg, i.p.)-injected animals. Moreover, experimentally evoked LTP was impaired in SCH58261- injected mice. In conclusion, the endogenous activation of adenosine A2A receptors plays a pivotal effect on the associative learning process and its relevant hippocampal circuits, including activity-dependent changes at the CA3-CA1 synapse.This study was supported by grants from the Spanish Ministry of Education and Research (BFU2005-01024 and BFU2005-02512), Spanish Junta de AndalucÃa (BIO-122 and CVI-02487), and the Fundación Conocimiento y Cultura of
the Pablo de Olavide University (Seville, Spain).B. Fontinha was in receipt of a studentship from a project grant (POCI/SAU-NEU/56332/2004) supported by Fundação para a Ciência e Tecnologia (FCT, Portugal), and of an STSM from Cost B30 concerted action of the EU
Portuguese Football Federation consensus statement 2020: nutrition and performance in football
Nutrition is an undeniable part of promoting health and performance among football (soccer) players. Nevertheless, nutritional strategies adopted in elite football can vary significantly depending on culture, habit and practical constraints and might not always be supported by scientific evidence. Therefore, a group of 28 Portuguese experts on sports nutrition, sports science and sports medicine sought to discuss current practices in the elite football landscape and review the existing evidence on nutritional strategies to be applied when supporting football players. Starting from understanding football's physical and physiological demands, five different moments were identified: preparing to play, match-day, recovery after matches, between matches and during injury or rehabilitation periods. When applicable, specificities of nutritional support to young athletes and female players were also addressed. The result is a set of practical recommendations that gathered consensus among involved experts, highlighting carbohydrates periodisation, hydration and conscious use of dietary supplements.info:eu-repo/semantics/publishedVersio
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