Silence in the Coffee Plantation: The Painting-poetics of Candido Portinari

This article wants to analyze how Candido Portinari in his paintings with rural theme, engages a poetry of silence. To understand the functioning of this poetic language, we will adopt the Groupe μ analysis method (both the General Rhetoric andthe Treatise on theVisual Sign). Whereas the language is manifold as the forms of representation, and it present in all media, whatever the lack of speech -silence -would find its richest form in both directions through the metaphors and metonymy engaged in metasememes of the paintings studied

Learning roadmaps for Higher Education

An integrated platform for the support of teaching activities as been developed and deployed at the Aveiro Norte Polytechnic School of the University of Aveiro. In this paper we present an approach to Learning Roadmaps for Higher Education based on this platform. The aprend.e platform – Electronic Integrated System for Learning and Training - has at its core a Learning Management System with a number of plugins. It represents a new challenge for the University of Aveiro for higher education and is already being at its core is the concept of learning roadmaps that act upon two fundamental axes: education and learning. For the teachers, it aims at becoming a self-supporting tool that stimulates the organization and management of the course materials (lectures, presentations, multimedia content, and evaluation materials, amongst others). For the students, the learning roadmap aims at promoting self-study and supervised study, endowing the pupil with the capabilities to find the relevant information and to capture the concepts in the study materials. The outcome will be a stimulating learning process together with an organized management of those materials

Evolução cromossômica de espécies do gênero Ctenomys

Ctenomys, popularmente conhecido como tuco-tucos, é o gênero mais especioso entre os roedores subterrâneos, cerca de 65 espécies. Entre os mamíferos, Ctenomys é o grupo com a maior variação cromossômica, com números diploides variando de 2n=10 para C. steinbachi, à 2n=70 para C. pearsoni e C. dorbignyi, além de variações intraespecíficas, C. minutus (2n=42 à 50) e C. lami (2n=54 à 58). No Brasil, são descritas oito espécies de Ctenomys: Ctenomys bicolor (Rondônia), Ctenomys rondoni (Mato Grosso), Ctenomys nattereri (Mato Grosso), Ctenomys flamarioni (Rio Grande do Sul), Ctenomys lami (Rio Grande do Sul), Ctenomys minutus (Santa Catarina e Rio Grande do Sul), Ctenomys ibicuiensi (Rio Grande do Sul) e Ctenomys torquatus (Rio Grande do Sul). Todas as espécies do Sul do Brasil possuem descrição cariotípica e padrão de bandeamento, sendo C. minutus e C. lami, espécies irmãs e que possuem a maior variação cariotípica intraespecífica. Apesar de muitos trabalhos descrevendo os diferentes cariótipos, estudos utilizando citogenética molecular são incipientes e ainda não se tem claro como os mecanismos de especiação cromossômica podem influenciar a diferenciação destas espécies. Enquanto as espécies do Centro-oeste e Norte, apenas C. bicolor possui a descrição do seu cariótipo (2n=40), assim carecem de informações e comparações entre as espécies destas regiões. Sabendo-se destas lacunas o objetivo desta tese foi contribuir no desenvolvimento do conhecimento sobre mecanismos de evolução cromossômica, por meio de diferentes abordagens de análise, aprofundando o conhecimento sobre a organização genômica e cromossômica nas espécies do gênero Ctenomys presentes no Brasil. Para isso, além de uma revisão dos dados citogenéticos do gênero, foram utilizadas métodos de citogenética clássica (NORs, Banda-C e G) e citogenética molecular (FISH – hibridização in situ fluorescente), com diferentes conjuntos de sondas de DNA (de cromossomos inteiros, microssatélites e elemento transponível) em espécies com ocorrência no Brasil. Empregando a técnica de FISH utilizando sondas de microssatélites e elemento transponível (L1) em diferentes citótipos de C. minutus, identificamos o papel das sequências repetitivas na variação cariótipica desta espécie, mostramos que diferentes citótipos apresentam diferenças no padrão de distribuição e na quantidade de sinais para as diferentes sondas. E utilizando sondas de cromossomos inteiros de C. flamarioni, realizamos a pintura cromossômica em diferentes citótipos de C. minutus e C. lami, identificamos os rearranjos intracromossômicos que ocorrerem entre os diferentes citótipos da mesma espécie e as homeologias entre as três espécies. Utilizando estas abordagens de citogenética clássica descremos dois cariótipos para espécies do centro-oeste, além dos padrões de heterocromatina, NORs e bandeamento G para C. bicolor, C. nattereri e C.sp. “xingu” e C. sp “central”. Assim, descrevemos os possíveis rearranjos ocorridos para diferenciação dos cariótipos destas espécies. Essas evidências encontradas demonstram como o gênero Ctenomys é um ótimo modelo para entender evolução cromossômica e os mecanismos de especiação cromossômicas.Ctenomys, popularly known as tuco-tucos, is the most specious genus among subterranean rodents, with about 65 described species. Among mammals, Ctenomys is the current group that has the greatest chromosomal variation, with diploid numbers ranging from 2n=10 for C. steinbachi, to 2n=70 for C. pearsoni and C. dorbignyi, in addition to intraspecific variations, as in C. minutus (2n=42 to 50) and C. lami (2n=54 to 58). In Brazil, eight species of Ctenomys were described, namely: Ctenomys bicolor (Rondônia), Ctenomys rondoni (Mato Grosso), Ctenomys nattereri (Mato Grosso), Ctenomys flamarioni (Rio Grande do Sul), Ctenomys lami (Rio Grande do Sul), Ctenomys minutus (Rio Grande do Sul and Santa Catarina), Ctenomys ibicuiensi (Rio Grande do Sul) and Ctenomys torquatus (Rio Grande do Sul). All species from southern Brazil have a karyotype description and banding pattern, with C. minutus and C. lami, sister species that have the greatest karyotype variation. Despite many works describing the different karyotypes, studies using molecular cytogenetic are incipient and it is still unclear how chromosomal speciation can influence the differentiation of these species. While the species from Midwest and North, only C. bicolor has the description of its karyotype (2n=40), thus, information and comparisons between the species of these regions are lacking. Knowing these gaps, the objective of this thesis was to contribute to the development of knowledge about the mechanisms of chromosomal evolution through different analysis approaches, deepening the knowledge about the genomic and chromosomal organization in species of the genus Ctenomys present in Brazil. For this, in addition to a review of the cytogenetic data of the genus, methods of classical cytogenetic (NORs, C-Band, and G) and molecular cytogenetic (FISH - fluorescent in situ hybridization) were used, with different sets of DNA probes (from chromosomes integers, microsatellites, and transposable element) in species occurring in Brazil. Employing the FISH technique using microsatellite probes and transposable element (L1) in different cytotypes of C. minutus, we identified the role of repetitive sequences in the karyotype variation of this species, we showed that different cytotypes present differences in the distribution pattern and the number of signals for the different probes. In addition, using probes of whole chromosomes of C. flamarioni, we performed the chromosome painting in different cytotypes of C. minutus and C. lami, we identified the intrachromosomal rearrangements that occur between the different cytotypes of the same species and the homeologies between the three species. Using these classical cytogenetic approaches, we describe two karyotypes for Midwestern species: heterochromatin, NORs, and G-banding patterns for C. bicolor, C. nattereri, and C.sp. "xingu". Thus, we describe the possible rearrangements that occurred to differentiate the karyotypes of these species. This evidence demonstrates how the genus Ctenomys is a great model for understanding chromosomal evolution and the mechanisms of chromosomal speciation

A gold nanoparticle based colorimetric test allied to Salmonella LAMP amplification: toward the revolution of Food Quality Control

Microorganisms are the primary cause of food spoilage and foodborne illness. Every year Salmonella causes 1.3 billion cases of disease worldwide, representing a considerable burden in both developing and developed countries. Despite of great advances in technologies in the last decade, current Salmonella detection methods are not fast and reliable enough. In order to address these issues a test based in the colorimetric properties of gold nanoparticles was combined with LAMP technique for the detection of Salmonella. Gold nanoparticles were synthesized and functionalised with thiol-modified DNA oligonucleotides (Gold nanoprobes) able to recognize the target sequence - ttrRSBCA locus from Salmonella. It was amplified by LAMP technique, which was optimized in this study. Four batches of gold nanoprobe were synthesized from two different batches of gold nanoparticles and under different pH. The arising gold nanoprobes showed some differences between them, namely in their stability and their detection capacity. These differences were investigated and it was verified that their cause was related to the conditions of functionalisation, namely ultrasound, ionic strength and nanoparticles size. The last was confirmed with TEM. Au-nanoprobes were then used in a colorimetric method for DNA detection based on a non-cross-linking approach - upon increasing ionic strength, Au-nanoprobes aggregate and the solution changes colour from the original red to blue, due to the red-shift of the typical Surface Plasmon Resonance (SPR) band of gold nanoparticles; the presence of a complementary target to the probe sequence, prevents aggregation of the Au-nanoprobes and the solution remains red. Gold nanoprobes detection capacity was tested with LAMP and PCR products and it was verified that a better discrimination is achieved with PCR products. The system developed here presents some advantages but still needs optimisation for further application in pathogen detection in food

A Framework for the Design and Implementation of Learning Objects: a Competence-based Approach

This paper presents a framework for the design and implementation of learning objects using a competence-based approach. This framework is illustrated by the development of a standalone Windows application (Trilho GOA) whose primary purpose is to create standardized pedagogical contents trough the aggregation and standardization of instructional resources in several formats that can be used later on a Learning Management System (LMS) supporting SCORM 1.2. The paper contains a brief introduction to the developed software, its system architecture, main features and several pedagogical advantages for its users