Conhecimento e formação de futuros professores dos primeiros anos – o sentido de número racional

Nos últimos anos o conhecimento do professor tem vindo a ser reconhecido como um dos aspetos nucleares no, e para o, desenvolvimento do conhecimento matemático dos alunos. Atendendo a essa centralidade, a formação deverá focar-se onde é, efetivamente, necessária, de modo a potenciar um incremento do conhecimento dos alunos, pelo conhecimento (e práticas) dos professores. Sendo os números racionais um dos tópicos problemáticos para os alunos, é fundamental identificar quais as situações matematicamente (mais) críticas para os professores de modo que, pela formação facultada, possam deixar de o ser. Neste artigo, tendo por foco o conhecimento matemático do professor e as suas especificidades, discutimos alguns aspetos desse conhecimento de futuros professores sobre números racionais, em concreto o sentido de número racional, identificando as suas componentes mais problemáticas e equacionando alguns dos porquês em que se sustentam. Terminamos com algumas considerações sobre implicações para a formação de professores e responsabilidade dos seus formadores.Abstract: In recent years, teachers’ knowledge has come to be recognized as one of the core aspects in and for the development of students’ mathematical knowledge. This being the case, training should focus on where it is really required, in such a way as to increase the knowledge of students through the knowledge and practice of teachers. Rational numbers are notoriously difficult for students and it is essential to identify mathematically critical situations for teachers, so that, through training, they cease to be problematic. In this article, with its focus on specific aspects of teachers’ mathematical knowledge, we shall discuss prospective teacher’s knowledge with regard to rational numbers, specifically rational number sense, identifying its components and considering some of the reasons for the problems associated with it. We shall finish with a few considerations of the implications for teacher education and the responsibility of the trainersRésumé: Ces dernières années, le savoir de l'enseignant a été reconnu comme l'un des aspects fondamentaux, dans et pour le développement des connaissances mathématiques des élèves. Face à cette centralité, la formation devra se concentrer là où cela est effectivement nécessaire, afin de favoriser un accroissement de la connaissance des élèves, sur la connaissance (et pratique) des enseignants. Puisque les nombres rationnels sont un des sujets les plus problématiques pour les étudiants, il est essentiel d’identifier quelles sont les situations mathématiquement (les plus) critiques pour les enseignants afin que, grâce à la formation dispensée, elles puissent cesser de l'être. Dans cet article, centré sur les connaissances mathématiques des enseignants et leurs spécificités, nous discutons certains aspects de cette connaissance des futurs enseignants sur les nombres rationnels, plus précisément le sens du nombre rationnel, identifiant les éléments les plus problématiques et réfléchissant sur les raisons qui les justifient. Nous terminons avec quelques réflexions sur les implications pour la formation des enseignants et la responsabilité de leurs formateurs

Sexual Differences in Prevalence of a New Species of Trypanosome Infecting Túngara Frogs

Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus), a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp.), were examined for try- panosomes. Our results revealed sexual differences in trypanosome prevalence with female frogs being rarely infected (\u3c1%). This finding suggests this protozoan parasite may be transmitted by frog-biting midges that find their host using the mating calls produced by male frogs. Following previous anuran trypanosome studies, we examined 18S ribosomal RNA gene to characterize and establish the phylo- genetic relationship of the trypanosome species found in túngara frogs. A new species of giant trypanosome, Trypanosoma tungarae n. sp., is described in this study. Overall the morphometric data revealed that the trypomastigotes of T. tungarae n. sp. are similar to other giant trypanosomes such as Trypanosoma rotatorium and Trypanosoma ranarum. Despite its slender and long cell shape, however, 18S rRNA gene sequences revealed that T. tungarae n. sp. is sister to the rounded-bodied giant trypanosome, Trypanosoma chattoni. Therefore, morphological convergence explains similar morphology among members of two non-closely related groups of trypanosomes infecting frogs. The results from this study underscore the value of coupling morphological identification with molecular characterization of anuran trypanosomes

Genetic diversity of two Portuguese populations of the pullet carpet shell Venerupis senegalensis, based on RAPD markers: contribution to a sustainable restocking program

The pullet carpet shell Venerupis senegalensis (=V. pullastra) is a commercially important species in Portugal, Spain, France, and Italy. In Portugal, this species was once abundant in the Ria Formosa (southern Portugal

Evaluating evolutionary algorithms and differential evolution for the online optimization of fermentation processes

Although important contributions have been made in recent years within the field of bioprocess model development and validation, in many cases the utility of even relatively good models for process optimization with current state-of-the-art algorithms (mostly offline approaches) is quite low. The main cause for this is that open-loop fermentations do not compensate for the differences observed between model predictions and real variables, whose consequences can lead to quite undesirable consequences. In this work, the performance of two different algorithms belonging to the main groups of Evolutionary Algorithms (EA) and Differential Evolution (DE) is compared in the task of online optimisation of fed-batch fermentation processes. The proposed approach enables to obtain results close to the ones predicted initially by the mathematical models of the process, deals well with the noise in state variables and exhibits properties of graceful degradation. When comparing the optimization algorithms, the DE seems the best alternative, but its superiority seems to decrease when noisier settings are considered.Fundo Europeu de Desenvolvimento Regional (FEDER)Fundação para a Ciência e a Tecnologia (FCT

Near- and Middle-Infrared Monitoring of Burned Areas from Space

We describe a methodology to discriminate burned areas and date burning events that use a burn-sensitive (V, W) index system defined in near-/mid-infrared space. Discrimination of burned areas relies on a monthly composite of minimum of W and on the difference between this composite and that of the previous month. The rationale is to identify pixels with high confidence of having burned and aggregate new burned pixels on a contextual basis. Dating of burning events is based on the analysis of time series of W, and searching for the day before maximum temporal separability is achieved. The procedure is applied to the fire of Monchique, a large event that took place in the southwest of Portugal in August 2018. When the obtained pattern of burned pixels is compared against a reference map, the overall accuracy is larger than 99%; the commission and omission errors are lower than 5 and 10%, respectively; and the bias and the Dice coefficient are above 0.95 and 0.9, respectively. Differences between estimated dates of burning and reference dates derived from remote-sensed observations of active fires show a bias of 0.03 day and a root mean square difference of 0.24 day

Sensory profiling of complex meals : the case study of baked cod with cream and duck

Sensory analysis provides important information for developing new products and improving existing ones on the market. In fact, this science appears as a link between research and the development of innovative foods and their acceptance by the consumer [1]. The main purpose of this study is to evaluate the effectiveness of sensory methodologies for profiling of complex meals such as baked cod with cream and duck rice. Evaluation was performed with two sets of eight samples of industrial cod with cream and duck rice. Two independent trained panels of 9 and 12 judges evaluated the samples according to Quantitative Descriptive Analysis (QDA). Two independent panels of 16 untrained judges applied the Flash-Profile (FP) methodology over four sessions: attribute generation; final attribute list choice; evaluation 1 and 2. Two consumer panels evaluated the overall acceptance of each set of samples, on a sequential monadic presentation. For duck rice meals, the correlation between QDA and FP was not high (RV=0,646), and consumers preferred samples characterized by rice colour intensity, amount of duck, oiliness, bacon and chorizo in the meal. For cod with cream meals, the consumers preferred the samples characterized by amount and size of the cod pieces and intensity of cod taste, with a high correlation between FP and QDA (RV=0,860). Both sensory descriptive methodologies provide us with reliable and robust data in the characterization of complex meals. The FP methodology is relevant when working with panels of consumers to the extent that allows it to use their own lexicon of attributes. The application of external preference mapping on consumers’ response to FP emerges as a quick tool, either to describe products or to be used by food companies that have difficulties in using trained assessors’ panels. References: [1] Siegrist, M. (2008) Factors influencing public acceptance of innovative food technologies and products. Trends in Food Science & Technology, 19, 603-608

Application of eye-tracking technology for the evaluation of different packaging designs for premium organic herbal teas

The main goal of this study was to assess the impact four graphic designs (figure 1) on the perception of different extrinsic characteristics (premium and organic denomination, infusion name and brand).info:eu-repo/semantics/publishedVersio

Acceptance of fish and fish products by Portuguese young consumers: an exploratory study based on mothers’ evaluation

Portugal is one of the major fish consuming countries in the World, from where one may collect experiences in order to improve fish consumption in other countries. The aim of this research is to explore the factors that influence the consumption of fish and seafood among 8-14 year old children from the Oporto metropolitan area. A focus group was conducted with mothers of children to gain insights into their knowledge, attitudes and perceptions regarding the inclusion of fish and fish products as a regular part of their children’s diet. Narrative analysis was conducted based on Bardin content analysis. Findings indicated that children eat fish regularly, integrated into the family meal, and that mothers feel confident about their fish buying and preparation skills, leading them to incorporate fish regularly into family meals, with a choice of tastier easy to eat options.info:eu-repo/semantics/publishedVersio

Systematic automation of scenario-based testing of user interfaces

Ensuring the effectiveness factor of usability consists in ensuring that the application allows users to reach their goals and perform their tasks. One of the few means for reaching this goal relies on task analysis and proving the compatibility between the interactive application and its task models. Synergistic execution enables the validation of a system against its task model by co-executing the system and the task model and comparing the behavior of the system against what is prescribed in the model. This allows a tester to explore scenarios in order to detect deviations between the two behaviors. Manual exploration of scenarios does not guarantee a good coverage of the analysis. To address this, we resort to model-based testing (MBT) techniques to automatically generate scenarios for automated synergistic execution. To achieve this, we generate, from the task model, scenarios to be co-executed over the task model and the system. During this generation step we explore the possibility of including considerations about user error in the analysis. The automation of the execution of the scenarios closes the process. We illustrate the approach with an example.José Campos acknowledges support from project "NORTE01-0145-FEDER-000016", financed by the North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and through the European Regional Development Fund (ERDF