Tangible storytelling: let children play with the bits

The use of tangible objects makes it possible to create interactions, or dynamics, which are alternatives to the mouse and keyboard in the process of communicating with the computer. The construction of these objects incorporating electronic components lets us bring that momentum to another level. This meeting with the technology allows children to take an active role, while there is a purpose of control over the objects, which becomes important to them. With the reinforcement of that control, the introduction of programmable digital electronic components also allows the child to develop, strengthen and feel the impact of their role as competent designer and creator of technology. Current technology allows the construction of these objects and the communication with computers at a low cost through micro-controllers, using, on one hand, the open source software and on the other the open hardware.info:eu-repo/semantics/publishedVersio

Civic Education in Basic School: Problems and Challenges in the Digital Age

This paper focus on the analysis of preliminary data of an ongoing study involving Portuguese teachers and students, in the non-disciplinary curricular area of Civic Education. The project aims at encouraging collaborative behaviour in educational communities, involving teachers and students in the development of digital contents, and at exploring different issues on citizenship education, under a case-based methodology. We believe this action research study is of relevance because it can unveil examples of good practices and innovative teaching strategies that need to be disseminated in this compulsory subject taking into account the results of recent studies, which exposed some of the inefficiency of the strategies adopted so far

Annual dynamics of nutrients in a temporary stream in Southern Portugal: contributions of the primary producers and the drainage basin

Under the Mediterranean climatic conditions, the annual precipitation distribution determines that many streams are temporary with surface flow interruption during the summer dry period in contrast to the high discharges during floods, observed from late autumn to early spring. As water flows through the drainage basin it can pick up nutrients, sediments and pollutions. These can affect the ecological processes causing eutrophication where primary producers’ growth is accelerated. In this study, the nutrient (N and P) concentrations were determined in water and river sediments, over a 3 years period in a 3rd order temporary stream reach of 500 m (Pardiela stream in Guadiana basin). The nutrients concentration in the water and in the sediment shows a decrease during the flood events due to the high discharge, followed by a rapid increase, although the nutrients concentrations in the sediments were smaller than in the water. The primary producers were studied during the same 3 years period, in terms of biomass of macrophytes, periphyton, and leaves fall in order to describe the annual patters. Complementary, a rapid assessment of N, P and C concentration in macrophytes was analyzed with the objective to determine their nutrients contribution to the system in summer (1047.35 g/m2) although with low contents of P, N and C. Periphyton represents a basal contribution of biomass to the system, with high levels along the year, decreasing immediately after flood events and increasing subsequently. Contrary to what is described for the north hemisphere, in this study the leaves start to fall at the end of spring as surface flow decreases. The maximum leaves fall coincides with the maximum stream contraction at the end of summer, contributing to a high stream bed detritus biomass accumulation (143 g/m2). The highest nutrient input to the system comes from the drainage basin, especially after the flood events which also lead 3 weeks later to an increase in macrophyte biomass. The global results obtained in this study give a contribution to understanding the underlying processes in a temporay Mediterranean system which is a key issue to determine flexible and adaptive ecological management, promoting the conservation of natural ecosystems under global changes conditions

Disentangling the minimum wage puzzle: an analysis of job accessions and separations from a longitudinal matched employer- employee data set

Changes in the legislation in mid-80s in Portugal provide remarkable conditions for economic analysis, as the minimum wage increased very sharply for a very specific group of workers. Relying on a matched employer-employee panel dataset, we model gross job flows - accessions and separations - in continuing firms, as well as in new firms and those going out of business, using a Poisson regression model applied to proportions. Worker behaviour is as well modelled. Employment trends for teenagers, the affected group, are contrasted against older workers, before and after the rise in the youth minimum wage. The major effect on teenagers of a rising minimum wage is the reduction of separations from the employer, which compensates for the reduction of accessions (to new and continuing firms) and the rising dismissals from firms closing down. This result suggests the relevance of supply side factors overcoming demand forces, as they indicate that job attachment for low wage youngsters rises following an increase in their minimum wage. In this sense, our results can reconcile some of the previous evidence that has been presented in the empirical literature when analysing the overall impact of the minimum wage on youth employment without looking at its sources.

Estimating trade balance for a small region: Beira–Estrela, Portugal

This paper estimates the trade balance for a small region located in inland Portugal – Beira Estrela – geographically defined as the merge of 3 official NUT III regions – Beira Interior Norte, Serra da Estrela and Cova da Beira. This estimate disaggregates by 31 commodities and includes four essential parts: first, the international trade of goods and services; second, the interregional trade of the same commodities; third, the net balance between in-region consumption by foreigner non-residents and the international consumption by residents and finally the equivalent net balance for Portuguese tourists visiting Beira-Estrela and the consumption of out Beira-Estrela Portuguese residents. Interregional trade (not available in official statistics) is the residual between supply and demand of the different groups of commodities corresponding to the columns and rows of a regional Make and Use table we derive for Beira-Estrela. This regional matrix is the outcome of the application of a simplified non-survey method to the Portuguese (National Accounts provided) Make and Use table decomposition. Moreover we set a survey on lodging and restaurant users that allowed the detachment of the interregional tourist consumption flows from the remaining interregional trade. The aim of this estimate is to assess the relative importance of tourism in the Beira-Estrela regional trade balance. Furthermore, we argue in the paper that, unlike countries, regions do not benefit from trade surpluses and these surpluses are just the counterpart of the income drainage or capital outflows, which weaken the economic region basis.

Bargained Wages, Wage Drift and the Design of the Wage Setting System

This paper aims at answering the question: How does a typically European bargaining system - with collective bargaining, extension mechanisms and national minimum wage - coexist with low unemployment rate and high wage flexibility? A unique data set on workers, firms and collective bargaining contracts in the Portuguese economy is used to analyze the determinants of both the bargained wage and the wage drift. Results indicate that wage drift stretches the returns to every worker and firm attribute, whereas it shrinks the returns to union bargaining power. Therefore, firm-specific arrangements, in the form of wage drift, partly offset collective bargaining, granting firms a high degree of freedom when setting wages. Union bargaining power raises the overall wage level, but lowers the returns on worker attributes, an outcome of the egalitarian policy pursued.

Unit commitment with valve-point loading effect

Valve-point loading affects the input-output characteristics of generating units, bringing the fuel costs nonlinear and nonsmooth. This has been considered in the solution of load dispatch problems, but not in the planning phase of unit commitment. This paper presents a mathematical optimization model for the thermal unit commitment problem considering valve-point loading. The formulation is based on a careful linearization of the fuel cost function, which is modeled with great detail on power regions being used in the current solution, and roughly on other regions. A set of benchmark instances for this problem is used for analyzing the method, with recourse to a general-purpose mixed-integer optimization solver

Missing value and comparison problems: what pupils know before the teaching of proportion

This paper analyses grade 6 pupils’ mathematical processes and difficulties in solving proportion problems before the formal teaching of this topic. Using a qualitative methodology, we examine pupils’ thinking processes at four levels of performance in missing value and comparison problems. The results show that pupils tend to use scalar composition and decomposition strategies in missing value problems and functional strategies in comparison problems. Pupils’ difficulties are related to a lack of recognition of the multiplicative nature of proportion relationships