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Contains fulltext : 54786.pdf (Publisher’s version ) (Closed access) In order to create adaptive Agent Systems with abilities matching those of their biological counterparts, a natural approach is to incorporate classical conditioning mechanisms into such systems. However, existing models for classical conditioning are usually based on differential equations. Since the design of Agent Systems is traditionally based on qualitative conceptual languages, these differential equations are often not directly appropriate to serve as an input for Agent System design. To deal with this problem, this paper introduces a formal approach to describe and analyse the dynamics of a conditioning process at a neural level. The approach is based on logical specification and analysis of dynamic properties of conditioning. The approach is illustrated for the case of Aplysia. 2005 Portugese Conference on Artificial Intelligence, EPIA’05

Framing in news is the way in which journalists depict an issue in terms of a 'central organizing idea.' Frames can be a perspective on an issue. We explore the automatic classification of four generic news frames: conflict, human interest, economic consequences, and morality. Complex characteristics of messages such as frames have been studied using thematic content analysis. Indicator questions are formulated, which are then manually coded by humans after reading a text and combined into a characterization of the message. We operationalize this as a classification task and, inspired by the way-of-working of media analysts, we propose a two-stage approach, where we first rate a news article using indicator questions for a frame and then use the outcomes to predict whether a frame is present. We approach human accuracy on almost all indicator questions and frames.

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Important sources of information are originally created in natural language. To make that knowledge computer processable it is necessary to understand the structure of natural languages, by adding lexical and syntactic information; to have a rich representation to encode the knowledge of sentences, like ontologies; and to develop algorithms to bridge the gap between natural languages and computer processable representations. In this paper we present the architecture, modules and results of a prototype that uses an ontology to represent the world concepts and their relationships, and also to guide the process of extracting information from natural language documents. The system was tested using minutes of Portuguese municipalities’ meetings. Initial results are presented for three topics of municipalities' affairs: the subsidies granted, the building permits requested, and the existing protocols with other institutions.

Objectives: This work had two aims: 1) To investigate how the sleep-wake cycle affects the phosphorylation levels of Ca(2+)/calmodulin- dependent protein kinase II (CaMKII), which plays a key role in memory consolidation and Zif268/Arc transcription; and 2) to investigate the relationship between spindle features and CaMKII phosphorylation levels. Methods and Results: Young adult male rats (n=24) were implanted with electrodes for chronic recordings of local field potentials in the dentate gyrus and cerebral cortex, to identify WK, SWS and REM (J Neurosci 24(49): 11137-11147, 2004). Experimental animals were allowed to explore 4 novel objects introduced in the recording box for 10 minutes as previously described (PLoS Biol 2(1): E24, 2004), while controls were unexposed to novel stimuli. The animals were then kept awake for 3 hours, to avoid detecting CaMKII phosphorylation directly related to the exploration of novel objects. Animals were then allowed to sleep and were decapitated immediately after entering SWS (at least 10 minutes) or REM (at least 2 minutes). Animals in the WK group had an additional 10 minutes of sleep deprivation before killing. The brains were quickly removed and the left hemispheres were frozen for immuhistochemistry assays, while the right hemispheres were used for protein extraction and immunoblots. Global phosphorylation levels of CaMKIIα (Thr286) assessed in immunoblots revealed a significant decrease in CaMKIIα activation during REM in rats exposed to novel objects, in comparison to WK. As expected, no statistically significant differences occurred in controls. Immunohistochemistry used to investigate CaMKII activation in three specific hippocampal regions (dentate gyrus, CA3 and CA1) revealed significant differences in animals exposed to novel objects: CamKII phosphorylation decreased from WK to SWS in the hippocampal cell layers analyzed, but there was a significant increase from SWS to REM. Controls displayed no significant differences. Novel experience was concomitant in our dataset with an increase in spindle density, which was strongly correlated with CAMKII phosphorylation levels in the REM group, but not in the WK or SWS groups. Conclusions: Our results suggest that experience-dependent changes in the density of spindles during SWS and/or intermediate sleep before REM determine subsequent levels of CAMKII phosphorylation in local hippocampal circuits, when assessed immediately after REM. A similar relationship relates spindle power and Zif-268 mRNA expression 30 minutes after REM (Frontiers in Neuroscience 1: 43-55, 2007), suggesting a causal chain linking spindles, CAMKII phosphorylation and zif-268 expression.

9 Páginas ; 4 Figuras ; 1 Tabla, 1. Mothers must balance the fecundity costs of increasing propagule size with the fitness benefits of increased propagule performance, and the propagule size-performance relationship is crucial for determining this trade-off. 2. While many studies have examined the propagule size-performance relationship in individual life-history stages, very few have examined the relationship between propagule size and performance across multiple life-history stages despite the ubiquity of complex life cycles. 3. We examined the consistency of the propagule size-performance relationship across several life-history stages in the marine invertebrate Microcosmus squamiger (Ascidiacea). 4. Propagule size had effects in some life-history stages and not others: larger propagules hatched sooner as larvae and grew more as juveniles in the field. On the other hand, propagule size had no effect on cell cleavage rates, larval swimming time or post-metamorphic survival in the field. 5. The effects of propagule size on juvenile size were persistent – juveniles that came from larger propagules were still larger than juveniles that came from smaller propagules after 11 weeks in the field. 6. We found no evidence of conflicting selection pressures on propagule size among life-history stages. Rather, in this species at least, the selection on propagule size at both the larval and juvenile stage appeared to favour the production of larger propagules. Nevertheless, the slope of the relationship between propagule size and performance was highly variable among life-history stages. 7. The effects of propagule size across multiple life-history stages are determined by the strength of selection pressures, which can be highly variable in organisms with complex life-cycles., Funding was obtained from project DPO6666147 of the Australian Research Council to DJM, the project CTM2007-66635 of the Spanish Government to XT. MR was supported by a travel grant from the Spanish ‘Ministerio de Educacio´n y Ciencia’ during his stay at the University of Queensland. GMD was supported by a Brazilian government grant from CAPES.

O monte da Penha, em Guimarães, agrega natureza e religiosidade. O sustentáculo do seu valor patrimonial natural reside na geodiversidade. Utilizando a metodologia de Pereira et al. (2007) para a avaliação do património geológico, foram identificados e caracterizados sete geossítios, que apresentam valor científico e educacional elevado e para os quais se apontam estratégias de valorização. A sua divulgação contribuirá para aumentar a literacia científica e, indirectamente, para a geoconservação desta área., Penha, near Guimarães in Northern Portugal, joins nature and religion. The mainstay of its natural heritage value is the geodiversity. Using the method of Pereira et al. (2007) for the assessment of geological heritage, seven geosites were identified and characterized, presenting high scientific and pedagogical values, and for which valorization strategies are pointed out. Making this natural heritage public will be a contribution to the increase of scientific literacy and, indirectly, to the geoconservation of this area.

Made available in DSpace on 2018-08-02T00:16:16Z (GMT). No. of bitstreams: 1 tese_2696_Dissertação Germana Bueno Dias.pdf: 2994589 bytes, checksum: b39f33417d62639a9a3335101776f9c0 (MD5) Previous issue date: 2007-12-18 Resumo As plantas apresentam uma série de mecanismos que as tornam resistentes a doenças e pragas. Dessa forma, grupos de pesquisa de todo o mundo buscam definir o papel de cada substância participante dos processos bioquímicos de defesa das plantas. Tais estudos visam, dentre outras coisas, estabelecer plantas resistentes as principais doenças que ocorrem nas culturas. Uma das principais doenças que afetam plantações de mamão no Brasil é conhecida como meleira do mamoeiro, causada pelo Papaya meleira virus (PMeV). O objetivo desse trabalho foi avaliar a indução do sistema de defesa em mamoeiro (Carica papaya L.), cv. Golden pelo oxido nítrico (NO) e sua efetividade contra o PMeV. Para determinar os fatores histoquímicos e enzimáticos relacionados com as respostas de defesa induzidas pelo NO, incluindo a produção de espécies ativas de oxigênio, as plantas foram tratadas com o doador de NO, nitroprussiato de sódio (SNP) à 10 mM. As respostas de defesa foram analisadas nos tempos 0, 15, 30, 45 min, 1, 3, 6, 24; 48, 72 h, 15 e 30 dias após o tratamento. Essa resposta do SNP foi vista em todos os tempos analisados, mostrando a efetividade do NO nas plantas de mamoeiro. Esse estímulo desencadeado pelo SNP na indução da atividade da superóxido dismutase e peroxidase pode está relacionado com o estresse oxidativo, pois a fim de combatê-lo, as plantas desenvolvem defesas, através do aumento da atividade de enzimas antioxidantes. Desta forma, concluímos que o uso do elicitor poderá induzir a resposta de resistência em mamoeiro. Palavras-chave: Carica papaya, Espécies Reativas de Oxigênio, Estresse.

Apesar da criação relativamente recente das temáticas do património geológico e da geoconservação, alguns conteúdos são já abordados nos curricula dos Ensinos Básico e Secundário em Portugal. Estes temas podem promover e incentivar o ensino/aprendizagem da Geologia, sendo, no entanto, necessária uma adequada formação do corpo docente. De modo a satisfazer esta necessidade, apresenta-se o Curso de Mestrado em Património Geológico e Geoconservação, cuja primeira edição decorre actualmente na Universidade do Minho (Braga), com resultados promissores., Geoconservation and geological heritage concepts were recently included in the Portuguese school curricula. These subjects may contribute to the promotion of the Geology teaching/learning, in spite of the need of an adequate teachers training. In order to fulfil this requirement, a new master course on Geological Heritage and Geoconservation is presented. The first edition of this course is already taking place at the University of Minho (Braga) with promising results., Fundação para a Ciência e Tecnologia.