888 resultados para Task modification


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Microsphere systems with the ideal properties for bone regeneration need to be bioactive, and at the same time possess the capacity for controlled protein/drug-delivery; however, the current crop of microsphere system fails to fulfill these properties. The aim of this study was to develop a novel protein-delivery system of bioactive mesoporous glass (MBG) microspheres by a biomimetic method through controlling the density of apatite on the surface of microspheres, for potential bone tissue regeneration. MBG microspheres were prepared by using the method of alginate cross-linking with Ca2+ ions. The cellular bioactivity of MBG microspheres was evaluated by investigating the proliferation and attachment of bone marrow stromal cell (BMSC). The loading efficiency and release kinetics of bovine serum albumin (BSA) on MBG microspheres were investigated after coprecipitating with biomimetic apatite in simulated body fluids (SBF). The results showed that MBG microspheres supported BMSC attachment and the Si containing ionic products from MBG microspheres stimulated BMSCs proliferation. The density of apatite on MBG microspheres increased with the length of soaking time in SBF. BSA-loading efficiency of MBG was significantly enhanced by co-precipitating with apatite. Furthermore, the loading efficiency and release kinetics of BSA could be controlled by controlling the density of apatite formed on MBG microspheres. Our results suggest that MBG microspheres are a promising protein-delivery system as a filling material for bone defect healing and regeneration.

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BACKGROUND: Support and education for parents faced with managing a child with atopic dermatitis is crucial to the success of current treatments. Interventions aiming to improve parent management of this condition are promising. Unfortunately, evaluation is hampered by lack of precise research tools to measure change. OBJECTIVES: To develop a suite of valid and reliable research instruments to appraise parents' self-efficacy for performing atopic dermatitis management tasks; outcome expectations of performing management tasks; and self-reported task performance in a community sample of parents of children with atopic dermatitis. METHODS: The Parents' Eczema Management Scale (PEMS) and the Parents' Outcome Expectations of Eczema Management Scale (POEEMS) were developed from an existing self-efficacy scale, the Parental Self-Efficacy with Eczema Care Index (PASECI). Each scale was presented in a single self-administered questionnaire, to measure self-efficacy, outcome expectations, and self-reported task performance related to managing child atopic dermatitis. Each was tested with a community sample of parents of children with atopic dermatitis, and psychometric evaluation of the scales' reliability and validity was conducted. SETTING AND PARTICIPANTS: A community-based convenience sample of 120 parents of children with atopic dermatitis completed the self-administered questionnaire. Participants were recruited through schools across Australia. RESULTS: Satisfactory internal consistency and test-retest reliability was demonstrated for all three scales. Construct validity was satisfactory, with positive relationships between self-efficacy for managing atopic dermatitis and general perceived self-efficacy; self-efficacy for managing atopic dermatitis and self-reported task performance; and self-efficacy for managing atopic dermatitis and outcome expectations. Factor analyses revealed two-factor structures for PEMS and PASECI alike, with both scales containing factors related to performing routine management tasks, and managing the child's symptoms and behaviour. Factor analysis was also applied to POEEMS resulting in a three-factor structure. Factors relating to independent management of atopic dermatitis by the parent, involving healthcare professionals in management, and involving the child in the management of atopic dermatitis were found. Parents' self-efficacy and outcome expectations had a significant influence on self-reported task performance. CONCLUSIONS: Findings suggest that PEMS and POEEMS are valid and reliable instruments worthy of further psychometric evaluation. Likewise, validity and reliability of PASECI was confirmed.

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Experts in injection molding often refer to previous solutions to find a mold design similar to the current mold and use previous successful molding process parameters with intuitive adjustment and modification as a start for the new molding application. This approach saves a substantial amount of time and cost in experimental based corrective actions which are required in order to reach optimum molding conditions. A Case-Based Reasoning (CBR) System can perform the same task by retrieving a similar case which is applied to the new case from the case library and uses the modification rules to adapt a solution to the new case. Therefore, a CBR System can simulate human e~pertise in injection molding process design. This research is aimed at developing an interactive Hybrid Expert System to reduce expert dependency needed on the production floor. The Hybrid Expert System (HES) is comprised of CBR, flow analysis, post-processor and trouble shooting systems. The HES can provide the first set of operating parameters in order to achieve moldability condition and producing moldings free of stress cracks and warpage. In this work C++ programming language is used to implement the expert system. The Case-Based Reasoning sub-system is constructed to derive the optimum magnitude of process parameters in the cavity. Toward this end the Flow Analysis sub-system is employed to calculate the pressure drop and temperature difference in the feed system to determine the required magnitude of parameters at the nozzle. The Post-Processor is implemented to convert the molding parameters to machine setting parameters. The parameters designed by HES are implemented using the injection molding machine. In the presence of any molding defect, a trouble shooting subsystem can determine which combination of process parameters must be changed iii during the process to deal with possible variations. Constraints in relation to the application of this HES are as follows. - flow length (L) constraint: 40 mm < L < I 00 mm, - flow thickness (Th) constraint: -flow type: - material types: I mm < Th < 4 mm, unidirectional flow, High Impact Polystyrene (HIPS) and Acrylic. In order to test the HES, experiments were conducted and satisfactory results were obtained.

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Vigilance declines when exposed to highly predictable and uneventful tasks. Monotonous tasks provide little cognitive and motor stimulation and contribute to human errors. This paper aims to model and detect vigilance decline in real time through participant’s reaction times during a monotonous task. A lab-based experiment adapting the Sustained Attention to Response Task (SART) is conducted to quantify the effect of monotony on overall performance. Then relevant parameters are used to build a model detecting hypovigilance throughout the experiment. The accuracy of different mathematical models are compared to detect in real-time – minute by minute - the lapses in vigilance during the task. We show that monotonous tasks can lead to an average decline in performance of 45%. Furthermore, vigilance modelling enables to detect vigilance decline through reaction times with an accuracy of 72% and a 29% false alarm rate. Bayesian models are identified as a better model to detect lapses in vigilance as compared to Neural Networks and Generalised Linear Mixed Models. This modelling could be used as a framework to detect vigilance decline of any human performing monotonous tasks.

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his case study aims to describe how general parenting principles can be used as part of parent-led, family-focused child weight management that is in line with current Australian Clinical Practice Guidelines. A parent-led, family-focused child weight management program was designed for use by dietitians with parents of young children (five- to nine-year-olds). The program utilises the cornerstones of overweight treatment: diet, activity, behaviour modification and family support delivered in an age-appropriate, family-focused manner. Parents participate in 16 sessions (4 parenting-focused, 8 lifestyle-focused and 4 individual telephone support calls) conducted weekly, fortnightly then monthly over six months. This case study illustrates how a family used the program, resulting in reduced degree of overweight and stabilised waist circumference in the child over 12 months. In conclusion, linking parenting skills to healthy family lifestyle education provides an innovative approach to family-focused child weight management. It addresses key Australian Clinical Practice Guidelines, works at the family level, and provides a means for dietitians to easily adopt age-appropriate behaviour modification as part of their practice.

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In order to estimate the safety impact of roadway interventions engineers need to collect, analyze, and interpret the results of carefully implemented data collection efforts. The intent of these studies is to develop Accident Modification Factors (AMF's), which are used to predict the safety impact of various road safety features at other locations or in upon future enhancements. Models are typically estimated to estimate AMF's for total crashes, but can and should be estimated for crash outcomes as well. This paper first describes data collected with the intent estimate AMF's for rural intersections in the state of Georgia within the United Sates. Modeling results of crash prediction models for the crash outcomes: angle, head-on, rear-end, sideswipe (same direction and opposite direction) and pedestrian-involved crashes are then presented and discussed. The analysis reveals that factors such as the Annual Average Daily Traffic (AADT), the presence of turning lanes, and the number of driveways have a positive association with each type of crash, while the median width and the presence of lighting are negatively associated with crashes. The model covariates are related to crash outcome in different ways, suggesting that crash outcomes are associated with different pre-crash conditions.

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Balancing between the provision of high quality of service and running within a tight budget is one of the biggest challenges for most metro railway operators around the world. Conventionally, one possible approach for the operator to adjust the time schedule is to alter the stop time at stations, if other system constraints, such as traction equipment characteristic, are not taken into account. Yet it is not an effective, flexible and economical method because the run-time of a train simply cannot be extended without limitation, and a balance between run-time and energy consumption has to be maintained. Modification or installation of a new signalling system not only increases the capital cost, but also affects the normal train service. Therefore, in order to procure a more effective, flexible and economical means to improve the quality of service, optimisation of train performance by coasting point identification has become more attractive and popular. However, identifying the necessary starting points for coasting under the constraints of current service conditions is no simple task because train movement is attributed by a large number of factors, most of which are non-linear and inter-dependent. This paper presents an application of genetic algorithms (GA) to search for the appropriate coasting points and investigates the possible improvement on computation time and fitness of genes.

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The driving task requires sustained attention during prolonged periods, and can be performed in highly predictable or repetitive environments. Such conditions could create hypovigilance and impair performance towards critical events. Identifying such impairment in monotonous conditions has been a major subject of research, but no research to date has attempted to predict it in real-time. This pilot study aims to show that performance decrements due to monotonous tasks can be predicted through mathematical modelling taking into account sensation seeking levels. A short vigilance task sensitive to short periods of lapses of vigilance called Sustained Attention to Response Task is used to assess participants‟ performance. The framework for prediction developed on this task could be extended to a monotonous driving task. A Hidden Markov Model (HMM) is proposed to predict participants‟ lapses in alertness. Driver‟s vigilance evolution is modelled as a hidden state and is correlated to a surrogate measure: the participant‟s reactions time. This experiment shows that the monotony of the task can lead to an important decline in performance in less than five minutes. This impairment can be predicted four minutes in advance with an 86% accuracy using HMMs. This experiment showed that mathematical models such as HMM can efficiently predict hypovigilance through surrogate measures. The presented model could result in the development of an in-vehicle device that detects driver hypovigilance in advance and warn the driver accordingly, thus offering the potential to enhance road safety and prevent road crashes.

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This study investigated preservice teachers’ perceptions for teaching and sustaining gifted and talented students while developing, modifying and implementing activities to cater for the diverse learner. Participants were surveyed at the end of a gifted and talented education program on their perceptions to differentiate the curriculum for meeting the needs of the student (n=22). SPSS data analysis with the five-part Likert scale indicated these preservice teachers agreed or strongly agreed they had developed skills in curriculum planning (91%) with well-designed activities (96%), and lesson preparation skills (96%). They also claimed they were enthusiastic for teaching (91%) and understanding of school practices and policies (96%). However, 46% agreed they had knowledge of syllabus documents with 50% claiming an ability to provide written feedback on student’s learning. Furthermore, nearly two-thirds suggested they had educational language from the syllabus and effective student management strategies. Preservice teachers require more direction on how to cater for diversity and begin creating sustainable societies by building knowledge from direct GAT experiences. Designing diagnostic surveys associated with university coursework can be used to determine further development for specific preservice teacher development in GAT education. Preservice teachers need to create opportunities for students to realise their potential by involving cognitive challenges through a differentiated curriculum. Differentiation requires modification of four primary areas of curriculum development (Maker, 1975) content (what we teach), process (how we teach), product (what we expect the students to do or show) and learning environment (where we teach/our class culture). Ashman and Elkins (2009) and Glasson (2008) emphasise the need for preservice teachers, teachers and other professionals to be able to identify what gifted and talented (GAT) students know and how they learn in relation to effective teaching. Glasson (2008) recommends that educators keep up to date with practices in pedagogy, support, monitoring and profiling of GAT students to create an environment conducive to achieving. Oral feedback is one method to communicate to learners about their progress but has advantages and disadvantages for some students. Oral feedback provides immediate information to the student on progress and performance (Ashman & Elkins, 2009). However, preservice teachers must have clear understandings of key concepts to assist the GAT student. Implementing teaching strategies to engage innovate and extend students is valuable to the preservice teacher in focusing on GAT student learning in the classroom (Killen, 2007). Practical teaching strategies (Harris & Hemming, 2008; Tomlinson et al., 1994) facilitate diverse ways for assisting GAT students to achieve learning outcomes. Such strategies include activities to enhance creativity, co-operative learning and problem-solving activities (Chessman, 2005; NSW Department of Education and Training, 2004; Taylor & Milton, 2006) for GAT students to develop a sense of identity, belonging and self esteem towards becoming an autonomous learner. Preservice teachers need to understand that GAT students learn in a different way and therefore should be assessed differently. Assessment can be through diverse options to demonstrate the student’s competence, demonstrate their understanding of the material in a way that highlights their natural abilities (Glasson, 2008; Mack, 2008). Preservice teachers often are unprepared to assess students understanding but this may be overcome with teacher education training promoting effective communication and collaboration in the classroom, including the provision of a variety of assessment strategies to improve teaching and learning (Callahan et al., 2003; Tomlinson et al., 1994). It is also critical that preservice teachers have enthusiasm for teaching to demonstrate inclusion, involvement and the excitement to communicate to GAT students in the learning process (Baum, 2002). Evaluating and reflecting on teaching practices must be part of a preservice teacher’s repertoire for GAT education. Evaluating teaching practices can assist to further enhance student learning (Mayer, 2008). Evaluation gauges the success or otherwise of specific activities and teaching in general (Mayer, 2008), and ensures that preservice teachers and teachers are well prepared and maintain their commitment to their students and the community. Long and Harris (1999) advocate that reflective practices assist teachers in creating improvements in educational practices. Reflective practices help preservice teachers and teachers to improve their ability to pursue improved learning outcomes and professional growth (Long & Harris, 1999). Context This study is set at a small regional campus of a large university in Queensland. As a way to address departmental policies and the need to prepare preservice teachers for engaging a diverse range of learners (see Queensland College of Teachers, Professional Standards for Teachers, 2006), preservice teachers at this campus completed four elective units within their Bachelor of Education (primary) degree. The electives include: 1. Middle years students and schools 2. Teaching strategies for engaging learners 3. Teaching students with learning difficulties, and 4. Middle-years curriculum, pedagogy and assessment. In the university-based component of this unit, preservice teachers engaged in learning about middle years students and schools, and gained knowledge of government policies pertaining to GAT students. Further explored within in this unit was the importance of: collaboration between teachers, parents/carers and school personnel in supporting middle years GAT students; incorporating challenging learning experiences that promoted higher order thinking and problem solving skills; real world learning experiences for students and; the alignment and design of curriculum, pedagogy and assessment that is relevant to the students development, interests and needs. The participants were third-year Bachelor of Education (primary) preservice teachers who were completing an elective unit as part of the middle years of schooling learning with a focus on GAT students. They were assigned one student from a local school. In the six subsequent ninety minute weekly lessons, the preservice teachers were responsible for designing learning activities that would engage and extend the GAT students. Furthermore, preservice teachers made decisions about suitable pedagogical approaches and designed the assessment task to align with the curriculum and the developmental needs of their middle years GAT student. This research aims to describe preservice teachers’ perceptions of their education for teaching gifted and talented students.

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Engineering graduates of today are required to adapt to a rapidly changing work environment. In particular, they are expected to demonstrate enhanced capabilities in both mono-disciplinary and multi-disciplinary teamwork environments. Engineering education needs, as a result, to further focus on developing group work capabilities amongst engineering graduates. Over the last two years, the authors trialed various group work strategies across two engineering disciplines. In particular, the effect of group formation on students' performance, task management, and social loafing was analyzed. A recently developed online teamwork management tool, Teamworker, was used to collect students' experience of the group work. Analysis showed that students who were allowed to freely allocate to any group were less likely to report loafing from other team members, than students who were pre-allocated to a group. It also showed that performance was more affected by the presence or absence of a leader in pre-allocated rather than free-allocated groups.

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This study investigated, validated, and applied the optimum conditions for a modified microwave assisted digestion method for subsequent ICP-MS determination of mercury, cadmium, and lead in two matrices relevant to water quality, that is, sediment and fish. Three different combinations of power, pressure, and time conditions for microwave-assisted digestion were tested, using two certified reference materials representing the two matrices, to determine the optimum set of conditions. Validation of the optimized method indicated better recovery of the studied metals compared to standard methods. The validated method was applied to sediment and fish samples collected from Agusan River and one of its tributaries, located in Eastern Mindanao, Philippines. The metal concentrations in sediment ranged from 2.85 to 341.06 mg/kg for Hg, 0.05 to 44.46 mg/kg for Cd and 2.20 to 1256.16 mg/kg for Pb. The results indicate that the concentrations of these metals in the sediments rapidly decrease with distance downstream from sites of contamination. In the selected fish species, the metals were detected but at levels that are considered safe for human consumption, with concentrations of 2.14 to 6.82 μg/kg for Hg, 0.035 to 0.068 μg/kg for Cd, and 0.019 to 0.529 μg/kg for Pb.

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This paper analyzes effects of different practice task constraints on heart rate (HR) variability during 4v4 smallsided football games. Participants were sixteen football players divided into two age groups (U13, Mean age: 12.4±0.5 yrs; U15: 14.6±0.5). The task consisted of a 4v4 sub-phase without goalkeepers, on a 25x15 m field, of 15 minutes duration with an active recovery period of 6 minutes between each condition. We recorded players’ heart rates using heart rate monitors (Polar Team System, Polar Electro, Kempele, Finland) as scoring mode was manipulated (line goal: scoring by dribbling past an extended line; double goal: scoring in either of two lateral goals; and central goal: scoring only in one goal). Subsequently, %HR reserve was calculated with the Karvonen formula. We performed a time-series analysis of HR for each individual in each condition. Mean data for intra-participant variability showed that autocorrelation function was associated with more short-range dependence processes in the “line goal” condition, compared to other conditions, demonstrating that the “line goal” constraint induced more randomness in HR response. Relative to inter-individual variability, line goal constraints demonstrated lower %CV and %RMSD (U13: 9% and 19%; U15: 10% and 19%) compared with double goal (U13: 12% and 21%; U15: 12% and 21%) and central goal (U13: 14% and 24%; U15: 13% and 24%) task constraints, respectively. Results suggested that line goal constraints imposed more randomness on cardiovascular stimulation of each individual and lower inter-individual variability than double goal and central goal constraints.

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Gaze and movement behaviors of association football goalkeepers were compared under two video simulation conditions (i.e., verbal and joystick movement responses) and three in situ conditions (i.e., verbal, simplified body movement, and interceptive response). The results showed that the goalkeepers spent more time fixating on information from the penalty kick taker’s movements than ball location for all perceptual judgment conditions involving limited movement (i.e., verbal responses, joystick movement, and simplified body movement). In contrast, an equivalent amount of time was spent fixating on the penalty taker’s relative motions and the ball location for the in situ interception condition, which required the goalkeepers to attempt to make penalty saves. The data suggest that gaze and movement behaviors function differently, depending on the experimental task constraints selected for empirical investigations. These findings highlight the need for research on perceptual— motor behaviors to be conducted in representative experimental conditions to allow appropriate generalization of conclusions to performance environments.

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The effective removal of pollutants using a thermally and chemically stable substrate that has controllable absorption properties is a goal of water treatment. In this study, the surfaces of thin alumina (γ-Al2O3) nanofibres were modified by the grafting either of two organosilane agents, 3-chloro-propyl-triethoxysilane (CPTES) and octyl-triethoxysilane (OTES). These modified materials were then trialed as absorbents for the removal of two herbicides, alachlor and imazaquin from water. The formation of organic groups during the functionalisation process established super hydrophobic sites on the surfaces of the nanofibres. This super hydrophobic group is a kind of protruding adsorption site which facilitates the intimate contact with the pollutants. OTES grafted substrate were shown to be more selective for alachlor while imazaquin selectivity is shown by the CPTES grafted substrate. Kinetics studies revealed that imazaquin was rapidly adsorbed on CPTES-modified surfaces. However, the adsorption of alachlor by OTES grafted surface was achieved more slowly.