Introducing programming to basic schools students using robotics

The present work reports on the development of programming activities with students from the 1st and 2nd cycles of schools in the town of Braga in the northwestern Portuguese region of Minho. These activities of promotion of computer programming were applied in order to promote the programming and innovative practices on science and technology education. The explored interdisciplinary methodologies in STEM teaching-learning processes, stimulate critical thinking and creativity while promoting the benefits of learning in collaborative environments. The active involvement of the students in these robot programming, “high tech” and trendy, activities is easy to achieve if the proposed challenges are set at an adequate level of difficulty and appealing enough to the age group and level of cognitive development of the student. Whenever possible to the students is given the possibility of choosing or even defining the problem/subject they will be exploring by programming a robot, which is seen as a mechanical artificial being the students will be able to understand, interact with and use and control. The teacher/educator should be available to provide to the students a proper empowering environment and to provide all support requested by the students giving, as much as possible, not straight answers but yes clues and small hints and examples leading the students to reach, themselves, to a solution to the problem the students face or to an answer to the students’ question that satisfy their own critical judgment. Through the programming testing process, it is possible to verify and see the level of perception and proficiency of the students assessing what students have learned and accomplished, creating immediate feedback for students and adjusting or re-orienting the students’ focus on a particular task or reasoning process. If well succeeded these activities can develop among the students a sound appreaciation towards Science Technology and Engineering while establishing relevant knowledge, creativity critical reasoning abilities and a large number of other competencies that will be valuable for the future development of the students in their studies and academic life but also in their future careers. The improvement of the self-esteem of the students when they realize they can actually “do it” is also a major benefit of this type of activities. As well in what concerns the boost of the self-esteem and selft-appreaciation of their teachers and educators, that often fear to explore this type of innovative approaches

Clustering Properties of Dynamical Dark Energy Models

We provide a generic but physically clear discussion of the clustering properties of dark energy models. We explicitly show that in quintessence-type models the dark energy fluctuations, on scales smaller than the Hubble radius, are of the order of the perturbations to the Newtonian gravitational potential, hence necessarily small on cosmological scales. Moreover, comparable fluctuations are associated with different gauge choices. We also demonstrate that the often used homogeneous approximation is unrealistic, and that the so-called dark energy mutation is a trivial artifact of an effective, single fluid description. Finally, we discuss the particular case where the dark energy fluid is coupled to dark matter.Comment: 5 page

HST's view of the youngest massive stars in the Magellanic Clouds

Accurate physical parameters of newborn massive stars are essential ingredients to shed light on their formation, which is still an unsolved problem. The rare class of compact H II regions in the Magellanic Clouds (MCs), termed ``high-excitation blobs'' (HEBs), presents a unique opportunity to acquire this information. These objects (~ 4" to 10", ~ 1 to 3 pc, in diameter) harbor the youngest massive stars of the OB association/molecular cloud complexes in the MCs accessible through high-resolution near-IR and optical techniques. We present a brief overview of the results obtained with HST mainly on two HEBs, one in the LMC (N159-5) and the other in the SMC (N81).Comment: 5 pages, to appear in the Proceedings of the 41st ESLAB Symposium "The Impact of HST on European Astronomy", 29 May to 1 June 2007, ESTEC, Noordwijk, Netherlands; eds. Guido De Marchi and Duccio Macchett

Resonance induced by repulsive interactions in a model of globally-coupled bistable systems

We show the existence of a competition-induced resonance effect for a generic globally coupled bistable system. In particular, we demonstrate that the response of the macroscopic variable to an external signal is optimal for a particular proportion of repulsive links. Furthermore, we show that a resonance also occurs for other system parameters, like the coupling strength and the number of elements. We relate this resonance to the appearance of a multistable region, and we predict the location of the resonance peaks, by a simple spectral analysis of the Laplacian matrix

Doenças do tomateiro sob cultivo protegido e em substrato de fibra de coco na Serra da Ibiapaba, Ceará.

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