Implications of missed opportunities for learning and assessment in design and technology education

Supporting student learning can be difficult, especially within open-ended or loosely structured activities, often seen as valuable for promoting student autonomy in many curriculum areas and contexts. This paper reports an investigation into the experiences of three teachers who implemented design and technology education ideas in their primary school classrooms for the first time. The teachers did not capitalise upon many of the opportunities for scaffolding their students' learning within the open-ended activities they implemented. Limitations of the teachers' conceptual and procedural knowledge of design and technology were elements that influenced their early experiences. The study has implications for professional developers planning programs in newly introduced areas of the curriculum to support teachers in supporting learning within open-ended and loosely structured problem solving activities. (C) 2001 Elsevier Science Ltd. All rights reserved.

The interaction of water flow and nutrients on aquatic plant growth

A long-term experiment was conducted to compare the effects of flowing and still water on growth, and the relationship between water flow and nutrients, in Aponogeton elongatus, a submerged aquatic macrophyte. A. elongatus plants were grown for 23 weeks with three levels of nutrition (0, 0.5 and 1g Osmocote Plus(R) fertiliser pot(-1)) in aquaria containing stirred or unstirred water. Fertilized plants grew much better than non-fertilized. The highest fertilizer level produced 29% wider leaves and 58% higher total dry weight in stirred water. Stirred water increased leaf area by 40% and tuber size by 81%, but only with the highest level of nutrition. These results suggest that this plant depends on its roots for mineral uptake, rather than from the open water, and the major limitation to growth in still water is the supply of dissolved inorganic carbon. It was the combined effects of nutrient availability and stirring that produced the strongest response in plant growth, morphology and composition. This study provides some explanation for the observations of others that these plants grow best in creeks or river systems with permanently flowing water.

The relationship of adult attachment dimensions to depression and agoraphobia

We examined the unique relations between the five dimensions of the Attachment Style Questionnaire (ASQ; Feeney, Noller, & Hanrahan, 1994) and depression and agoraphobic behavior (i.e., avoidance of situations where high anxiety is experienced). In addition, we examined mediation models in an attempt to clarify the link between adult attachment and these two dimensions of psychopathology. In testing these models, we administered the ASQ, General Self-Efficacy Scale, Agoraphobic Catastrophic Cognitions Questionnaire, Beck Depression Inventory, and the Mobility Inventory for Agoraphobia (a measure of the degree to which situations are avoided that are typically anxiety provoking for people with agoraphobia) to 122 participants (44 with agoraphobia, 25 with a current major depressive disorder, and 53 with no current psychopathology). The results showed that the insecure attachment dimensions of need for approval, preoccupation with relationships, and relationships as secondary were uniquely associated with depression and that general self-efficacy partly mediated the relationship between need for approval and depression. In contrast, only preoccupation with relationships was uniquely associated with agoraphobic behavior, and catastrophic cognitions about bodily sensations partly mediated this association.

O impacto da exposição a experiências adversas na infância na ocorrência de dor crônica e depressão na vida adulta

A associação entre experiências adversas na infância e o desencadeamento de depressão ou dor crônica na vida adulta tem sido documentada, assim como a relação entre os sintomas de dor crônica e depressão. No entanto, há poucos estudos avaliando o papel da exposição a experiências adversas na infância na ocorrência dessa comorbidade. O objetivo deste trabalho é avaliar a influência da exposição a experiências adversas na infância na ocorrência de dor crônica, de depressão e na comorbidade dor crônica e depressão na vida adulta, em uma amostra da população geral adulta (maiores de 18 anos) residente na Região metropolitana de São Paulo, Brasil. Os dados são resultantes do Estudo Epidemiológicos dos Transtornos Mentais São Paulo Megacity. Os respondentes foram avaliados usando a versão desenvolvida para o Estudo Mundial de Saúde Mental do Composite International Diagnostic Interview da Organização Mundial da Saúde (WMH-CIDI), que é composto por módulos clínicos e nãoclínicos provendo diagnósticos de acordo com os critérios do Manual Diagnóstico e Estatístico dos Transtornos Mentais 4ª edição (DSM-IV). Um total de 5.037 indivíduos foi entrevistado, com uma taxa global de resposta de 81,3%. Foram realizadas análises descritivas para médias e proporções, e associações (Razões de Chances – OR) entre experiências adversas na infância, dor crônica e depressão através de regressão logística. Todas as análises foram realizadas através do programa estatístico Data Analysis and Statistical Software versão 12.0 (STATA 12.0), com testes bi-caudais com nível de significância de 5%. Uma elevada taxa de prevalência de dor crônica (31%, Erro Padrão [ER]=0.8) foi encontrada, Dor Crônica esteve associada aos transtornos de ansiedade (OR=2,3; 95% IC=1,9 – 3,0), transtornos de humor (OR=3,3; IC=2,6 – 4,4) em qualquer transtorno mental (OR=2,7; 95% IC=2,3 – 3,3). As adversidades na infância estiveram fortemente associadas aos respondentes com dor crônica e depressão concomitante, principalmente quanto ao abuso físico (OR=2,7; 95% IC=2,1 – 3,5) e sexual (OR=7,4; 95% IC=3,4 – 16,1).

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment: 8- Survey of adult behaviour of Spissipes Section species of Culex (Melanoconion) in South-Eastern Brazil

A study of Spissipes Section of Culex (Melanoconion) adults behaviour was carried out from August 1992 through December 1993 in human dominated (anthropic) environment in the Ribeira Valley, S.Paulo State, Brazil. By sampling at several sites it the dominance of Culex ribeirensis and Cx. sacchettae became evident even through a total number of ten species was recorded. Those two mosquitoes showed a clear tendency to frequent the domiciliary environment where they were caught, both indoor and outdoor, through the use of the human bait. In the outside environments, the residual patchy forests seems to display a concentration role, from which these adults spread to the open land and reach the dwellings. As their vector competence has been demonstrated through the virus isolations in natural conditions, it is advisable to pay attention to the presence of these mosquitoes in the man-made environment.

Building a knowledge and learning society in Portugal: adult students in technological schools and higher education institutions

Lifelong learning (LLL) has received increasing attention in recent years. It implies that learning should take place at all stages of the “life cycle and it should be life-wide, that is embedded in all life contexts from the school to the work place, the home and the community” (Green, 2002, p.613). The ‘learning society’, is the vision of a society where there are recognized opportunities for learning for every person, wherever they are and however old they happen to be. Globalization and the rise of new information technologies are some of the driving forces that cause depreciation of specialised competences. This happens very quickly in terms of economic value; consequently, workers of all skills levels, during their working life, must have the opportunity to update “their technical skills and enhance general skills to keep pace with continuous technological change and new job requirements” (Fahr, 2005, p. 75). It is in this context that LLL tops the policy agenda of international bodies, national governments and non-governmental organizations, in the field of education and training, to justify the need for LLL opportunities for the population as they face contemporary employability challenges. It is in this context that the requirement and interest to analyse the behaviour patterns of adult learners has developed over the last few years

Effects of breastfeeding and sucking habits on malocclusion in a birth cohort study

OBJECTIVE: To estimate the prevalence of malocclusion and to examine the effects of breastfeeding and non-nutritive sucking habits on dentition in six-year-old children. METHODS: A cross-sectional study was carried out nested into a birth cohort conducted in Pelotas, Southern Brazil, in 1999. A sample of 359 children was dentally examined and their mothers interviewed. Anterior open bite and posterior cross bite were recorded using the Foster & Hamilton criteria. Information regarding breastfeeding and non-nutritive sucking habits was collected at birth, in the first, third, sixth and 12th months of life, and at six years of age. Control variables included maternal schooling and child's birthweight, cephalic perimeter, and sex. Data were analyzed by Poisson regression. RESULTS: Prevalence of anterior open bite was 46.2%, and that of posterior cross bite was 18.2%. Non-nutritive sucking habits between 12 months and four years of age and digital sucking at age six years were the main risk factors for anterior open bite. Breastfeeding for less than nine months and regular use of pacifier between age 12 months and four years were risk factors for posterior cross bite. Interaction between duration of breastfeeding and the use of pacifier was identified for posterior cross bite. CONCLUSIONS: Given that breastfeeding is a protective factor for other diseases of infancy, our findings indicate that the common risks approach is the most appropriate for the prevention of posterior cross bite in primary or initial mixed dentition.

Determining the number of clusters in categorical data

Cluster analysis for categorical data has been an active area of research. A well-known problem in this area is the determination of the number of clusters, which is unknown and must be inferred from the data. In order to estimate the number of clusters, one often resorts to information criteria, such as BIC (Bayesian information criterion), MML (minimum message length, proposed by Wallace and Boulton, 1968), and ICL (integrated classification likelihood). In this work, we adopt the approach developed by Figueiredo and Jain (2002) for clustering continuous data. They use an MML criterion to select the number of clusters and a variant of the EM algorithm to estimate the model parameters. This EM variant seamlessly integrates model estimation and selection in a single algorithm. For clustering categorical data, we assume a finite mixture of multinomial distributions and implement a new EM algorithm, following a previous version (Silvestre et al., 2008). Results obtained with synthetic datasets are encouraging. The main advantage of the proposed approach, when compared to the above referred criteria, is the speed of execution, which is especially relevant when dealing with large data sets.

Taxonomy of fundamental concepts of localization in cyber-physical and sensor networks

Localization is a fundamental task in Cyber-Physical Systems (CPS), where data is tightly coupled with the environment and the location where it is generated. The research literature on localization has reached a critical mass, and several surveys have also emerged. This review paper contributes on the state-of-the-art with the proposal of a new and holistic taxonomy of the fundamental concepts of localization in CPS, based on a comprehensive analysis of previous research works and surveys. The main objective is to pave the way towards a deep understanding of the main localization techniques, and unify their descriptions. Furthermore, this review paper provides a complete overview on the most relevant localization and geolocation techniques. Also, we present the most important metrics for measuring the accuracy of localization approaches, which is meant to be the gap between the real location and its estimate. Finally, we present open issues and research challenges pertaining to localization. We believe that this review paper will represent an important and complete reference of localization techniques in CPS for researchers and practitioners and will provide them with an added value as compared to previous surveys.

A survey in Portuguese X-ray fluoroscopy equipment: dose rates and image quality

X-ray fluoroscopy is essential in both diagnosis and medical intervention, although it may contribute to significant radiation doses to patients that have to be optimised and justified. Therefore, it is crucial to the patient to be exposed to the lowest achievable dose without compromising the image quality. The purpose of this study was to perform an analysis of the quality control measurements, particularly dose rates, contrast and spatial resolution of Portuguese fluoroscopy equipment and also to provide a contribution to the establishment of reference levels for the equipment performance parameters. Measurements carried out between 2007 and 2013 on 143 fluoroscopy equipment distributed by 34 nationwide health units were analysed. The measurements suggest that image quality and dose rates of Portuguese equipment are congruent with other studies, and in general, they are as per the Portuguese law. However, there is still a possibility of improvements intending optimisation at a national level.

Evaluating Android OS for embedded real-time systems

Since its official public release, Android has captured the interest from companies, developers and the general audience. From that time up to now, this software platform has been constantly improved either in terms of features or supported hardware and, at the same time, extended to new types of devices different from the originally intended mobile ones. However, there is a feature that has not been explored yet - its real-time capabilities. This paper intends to explore this gap and provide a basis for discussion on the suitability of Android in order to be used in Open Real-Time environments. By analysing the software platform, with the main focus on the virtual machine and its underlying operating system environments, we are able to point out its current limitations and, therefore, provide a hint on different perspectives of directions in order to make Android suitable for these environments. It is our position that Android may provide a suitable architecture for real-time embedded systems, but the real-time community should address its limitations in a joint effort at all of the platform layers.

Zigbee over tinyos: Implementation and experimental challenges

The IEEE 802.15.4/Zigbee protocols are a promising technology for Wireless Sensor Networks (WSNs). This paper shares our experience on the implementation and use of these protocols and related technologies in WSNs. We present problems and challenges we have been facing in implementing an IEEE 802.15.4/ZigBee stack for TinyOS in a two-folded perspective: IEEE 802.15.4/ZigBee protocol standards limitations (ambiguities and open issues) and technological limitations (hardware and software). Concerning the former, we address challenges for building scalable and synchronized multi-cluster ZigBee networks, providing a trade-off between timeliness and energy-efficiency. On the latter issue, we highlight implementation problems in terms of hardware, timer handling and operating system limitations. We also report on our experience from experimental test-beds, namely on physical layer aspects such as coexistence problems between IEEE 802.15.4 and 802.11 radio channels.

Democratic dialogue and collective learning in the context of self-managed teams

This paper provides a longitudinal, empirical view of the multifaceted and reciprocal processes of organizational learning in a context of self-managed teams. Organizational learning is seen as a social construction between people and actions in a work setting. The notion of learning as situated (Brown & Duguid 1989, Lave& Wenger 1991, Gherardi & al. 1998, Easterby-Smith & Araujo 1999, Abma 2003) opens up the possibility for placing the focus of research on learning in the community rather than in individual learning processes. Further, in studying processes in their social context, we cannot avoid taking power relations into consideration (Contu & Willmott 2003). The study is based on an action research with a methodology close to the ‘democratic dialogue’ presented by Gustavsen (2001). This gives a ground for research into how the learning discourse developed in the case study organization over a period of 5 years, during which time the company abandoned a middle management level of hierarchy and the teams had to figure out how to work as self-managed units. This paper discusses the (re)construction of power relations and its role in organizational learning. Power relations are discussed both in vertical and horizontal work relations. A special emphasis is placed on the dialectic between managerial aims and the space for reflection on the side of employees. I argue that learning is crucial in the search for the limits for empowerment and that these limits are negotiated both in actions and speech. This study unfolds a purpose-oriented learning process, constructing an open dialogue, and describes a favourable context for creative, knowledge building communities.