992 resultados para one way delay


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Histories of past communities are embedded in landscapes around the world but many are suffering from material change or neglect of their fabric. This study was aimed at discovering and representing the authentic intangible experience of two historic landscapes for conservation purposes. A 2500 year old site in Yangzhou, China and a 2000 year old site on St Helena Island in Moreton Bay were found to be managed under two culturally different regimes of authenticity. This research has contributed to challenging the notion that there is only one way to conserve authenticity in historic landscapes of the Asia Pacific.

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One way to consider Technology as other than an add-on might be to consider the opportunities to learn literacies opened by participation in technology. In this commentary Vinesh Chandra considers this in light of robotics lessons with primary school students as part of his work in the UR Learning project.

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Background Serum lutein (L) and zeaxanthin (Z) positively correlate with macular pigment optical density (MPOD), hence the latter is a valuable indirect tool for measuring L and Z content in the macula. L and Z have been attributed antioxidant capacity and protection from certain retinal diseases but their uptake within the eye is thought to depend on genetic, age and environmental factors. In particular gene variants within beta-carotene monooxygenase (BCMO1) are thought to modulate MPOD in the macula. Objectives: To determine the effect of BCMO1 single nucleotide polymorphisms (SNPs) rs11645428, rs6420424 and rs6464851 on macular pigment optical density (MPOD) in a cohort of young healthy participants of Caucasian origin with normal ocular health. Design In this cohort study, MPOD was assessed in 46 healthy participants (22 male and 24 female) with a mean age of 24 ± 4.0 years (range 19-33). The three SNPs, rs11645428, rs6420424, rs6564851 that have established associations with MPOD were determined using MassEXTEND (hME) Sequenom assay. One-way analysis of variance (ANOVA) was performed on groups segregated into homozygous and heterozygous BCMO1 genotypes. Correlations between body mass index (BMI), iris colour, gender, central retinal thickness (CRT), diet and MPOD were investigated. Results MPOD did not significantly vary with BCMO1 rs11645428 (F2,41 = 0.700, p = 0.503), rs6420424 (F2,41 = 0.210, p = 0.801) nor rs6464851 homozygous or heterozygous genotypes (F2,41 = 0,13, p = 0.88), in this young healthy cohort. The combination of these three SNPs into triple genotypes based on plasma conversion efficiency did not affect MPOD (F2,41 = 0.07, p = 0.9). There was a significant negative correlation with MPOD and central retinal thickness (r = - 0.39, p = 0.01) but no significant correlation between BMI, iris colour, gender and MPOD. Conclusion Our results indicate that macular pigment deposition within the central retina is not dependent on BCMO1 gene variants in young healthy people. We propose that MPOD is saturated in younger persons and/or other gene variant combinations determine its deposition.

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Purpose of this paper One way in which the tendering process can be further improved is by reviewing and clarifying the high costs that participants face during the course of the tendering phase. The study aims to provide project teams working in construction tender preparation a clear picture of what to expect when tendering for infrastructure projects. Design/methodology/approach Firstly, a review of current literature on tendering in infrastructure projects is conducted to identify the associated costs affecting traditional and PPP procurements as well as the potential measures contributing to tendering cost-reduction. A theoretical framework and its corresponding research hypotheses, which are based on the literature reviewed, are then proposed. An industry-wide questionnaire survey is currently under design to solicit industry practitioners’ views on tendering costs and the associated tendering cost-reduction measures. The data collected in the survey will subject to statistical analysis to test the proposed research hypotheses, which will be reported in a forthcoming paper. Findings and value The direct and indirect costs in public-private procurement have been identified and have been categorised into internal and external costs arising from working on tender submissions. A theoretical framework, mainly composed of five mechanisms of cost reduction, has been proposed and will be tested in a forthcoming industry-wide questionnaire survey. Originality/value of paper The findings are expected to lead to a transparent tendering process in infrastructure procurement, in which there is increased engagement from the private sector as well as an increase in competitive tendering.

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Bricolage is one way firms innovate in the midst of resource constraints. In this thesis bricolage in entrepreneurial firms is investigated as is its impact on firm performance. The research provides empirical tests of bricolage and firm performance and tests environmental dynamism and team compositions as moderating effects that impact the bricolage-performance relationship. The limits of bricolage during firm creation are also explored. This research offers several novel theoretical contributions and some suggestions for entrepreneurs who typically use bricolage in attempts of firm creation.

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Research shows that the beliefs individuals hold about knowledge and knowing (epistemic beliefs) influence learning approaches and outcomes. However, little is known about the nature of children’s epistemic beliefs and how best to measure these. In this pilot study, 11 Australian children (in Grade 4 or Grade 6) were asked to ‘draw, write and tell’ about their epistemic beliefs using drawings, written responses and interviews respectively. Drawings were analysed, with the majority of children depicting external, one-way sources of knowledge. The written statements and interviews were analysed using inductive thematic analysis, showing that children predominantly described knowledge acquisition as processes of task-based learning. Interviews also enabled children to describe a wider range of views. These results indicate that the methodological combination of ‘draw, write and tell’ allowed for a deeper understanding of the children’s epistemic beliefs which holds implications for future research.

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Background: Internationally, there is a growing concern for developing STEM education to prepare students for a scientifically and technologically advanced society. Despite educational bodies lobbying for an increased focus on STEM, there is limited research on how engineering might be incorporated especially in the elementary school curriculum. A framework of five comprehensive core engineering design processes (problem scoping, idea generation, design and construction, design evaluation, redesign), adapted from the literature on design thinking in young children, served as a basis for the study. We report on a qualitative study of fourth-grade students’ developments in working an aerospace problem, which took place during the first year of a 3-year longitudinal study. Students applied design processes together with their mathematics and science knowledge to the design and redesign of a 3-D model plane. Results: The study shows that through an aerospace engineering problem, students could complete initial designs and redesigns of a model plane at varying levels of sophistication. Three levels of increasing sophistication in students’ sketches were identified in their designs and redesigns. The second level was the most prevalent involving drawings or templates of planes together with an indication of how to fold the materials as well as measurements linked to the plane’s construction. The third level incorporated written instructions and calculations. Students’ engagement with each of the framework’s design processes revealed problem scoping components in their initial designs and redesigns. Furthermore, students’ recommendations for improving their launching techniques revealed an ability to apply their mathematics knowledge in conjunction with their science learning on the forces of flight. Students’ addition of context was evident together with an awareness of constraints and a consideration of what was feasible in their design creation. Interestingly, students’ application of disciplinary knowledge occurred more frequently in the last two phases of the engineering framework (i.e., design evaluation and redesign), highlighting the need for students to reach these final phases to enable the science and mathematics ideas to emerge. Conclusions: The study supports research indicating young learners’ potential for early engineering. Students can engage in design and redesign processes, applying their STEM disciplinary knowledge in doing so. An appropriate balance is needed between teacher input of new concepts and students’ application of this learning in ways they choose. For example, scaffolding by the teacher about how to improve designs for increased detail could be included in subsequent experiences. Such input could enhance students’ application of STEM disciplinary knowledge in the redesign process. We offer our framework of design processes for younger learners as one way to approach early engineering education with respect to both the creation of rich problem experiences and the analysis of their learning.

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Analysing the engagement of students in university-based Facebook groups can shed light on the nature of their learning experience and highlight leverage points to build on student success. While post-semester surveys and demographic participation data can highlight who was involved and how they subsequently felt about the experience, these techniques do not necessarily reflect real-time engagement. One way to gain insight into in-situ student experiences is by categorising the original posts and comments into predetermined frameworks of learning. This paper offers a systematic method of coding Facebook contributions within various engagement categories: motivation, discourse, cognition and emotive responses.

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Loneliness is a subjective distressing feeling of being disconnected from a desired group or intimate relationship. Most children and adolescents experience loneliness at some time but for 10-20% of young people it can be severe and chronic. While there are many avenues for help for distressed young people, such as friends and family as well as the professional help of counselors and psychologists, lonely young people often do not seek help. Telephone help-lines are one way to assist young people in difficulty which is cost effective, accessible and anonymous. Many countries provide this free or low cost help with specific services for youth either by telephone or online. From the call records of help-lines however, it would seem that lonely young people do not often utilize these services. The reasons for this apparent reluctance are discussed.

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Background There is no legal requirement for Iranian military truck drivers to undergo regular visual checkups as compared to commercial truck drivers. Objectives This study aimed to evaluate the impact of drivers’ visual checkups by comparing the visual function of Iranian military and commercial truck drivers. Patients and Methods In this comparative cross-sectional study, two hundred military and 200 commercial truck drivers were recruited and their Visual Acuity (VA), Visual Field (VF), color vision and Contrast Sensitivity (CS) were assessed and compared using the Snellen chart, confrontation screening method, D15 test and Pelli-Robson letter chart, respectively. A questionnaire regarding driving exposure and history of motor-vehicle crashes (MVCs) was also filled by drivers. Results were analyzed using an independent samples t-test, one-way ANOVA (assessing difference in number of MVCs across different age groups), chi-square test and Pearson correlation at statistical significance level of P < 0.05. Results Mean age was 41.6 ± 9.2 for the military truck drivers and 43.4 ± 10.9 for commercial truck drivers (P > 0.05). No significant difference between military and commercial drivers was found in terms of driving experience, number of MVCs, binocular VA, frequency of color vision defects and CS scores. In contrast, the last ocular examination was significantly earlier in military drivers than commercial drivers (P < 0.001). In addition, 4% of military drivers did not meet the national standards to drive as opposed to 2% of commercial drivers. There was a significant but weak correlation between binocular VA and age (r = 0.175, P < 0.001). However, CS showed a significantly moderate correlation with age (r = -0.488, P < 0.001). Conclusions The absence of legal requirement for regular eye examination in military drivers caused the incompetent drivers to be missed in contrast to commercial drivers. The need for scientific revision of VA standard for Iranian drivers is also discussed. The CS measurement in visual checkups of older drivers deserves to be investigated more thoroughly.

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The Disney method is a collaborative creativity technique that uses three roles - dreamer, realist and critic - to facilitate the consideration of different perspectives on a topic. Especially for novices it is important to obtain guidance in applying this method. One way is providing groups with a trained moderator. However, feedback about the group’s behavior might interrupt the flow of the idea finding process. We built and evaluated a system that provides ambient feedback to a group about the distribution of their statements among the three roles. Our preliminary field study indicates that groups supported by the system contribute more and roles are used in a more balanced way while the visualization does not disrupt the group work.

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Biventricular support with dual rotary ventricular assist devices (VADs) has been implemented clinically with restriction of the right VAD (RVAD) outflow cannula to artificially increase afterload and, therefore, operate within recommended design speed ranges. However, the low preload and high afterload sensitivity of these devices increase the susceptibility of suction events. Active control systems are prone to sensor drift or inaccurate inferred (sensor-less) data, therefore an alternative solution may be of benefit. This study presents the in vitro evaluation of a compliant outflow cannula designed to passively decrease the afterload sensitivity of rotary RVADs and minimize left-sided suction events. A one-way fluid-structure interaction model was initially used to produce a design with suitable flow dynamics and radial deformation. The resultant geometry was cast with different initial cross-sectional restrictions and concentrations of a softening diluent before evaluation in a mock circulation loop. Pulmonary vascular resistance (PVR) was increased from 50 dyne s/cm5 until left-sided suction events occurred with each compliant cannula and a rigid, 4.5 mm diameter outflow cannula for comparison. Early suction events (PVR ∼ 300 dyne s/cm5) were observed with the rigid outflow cannula. Addition of the compliant section with an initial 3 mm diameter restriction and 10% diluent expanded the outflow restriction as PVR increased, thus increasing RVAD flow rate and preventing left-sided suction events at PVR levels beyond 1000 dyne s/cm5. Therefore, the compliant, restricted outflow cannula provided a passive control system to assist in the prevention of suction events with rotary biventricular support while maintaining pump speeds within normal ranges of operation.

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Background Previously studies showed that inverse dynamics based on motion analysis and force-plate is inaccurate compared to direct measurements for individuals with transfemoral amputation (TFA). Indeed, direct measurements can appropriately take into account the absorption at the prosthetic foot and the resistance at the prosthetic knee. [1-3] However, these studies involved only a passive prosthetic knee. Aim The objective of the present study was to investigate if different types of prosthetic feet and knees can exhibit different levels of error in the knee joint forces and moments. Method Three trials of walking at self-selected speed were analysed for 9 TFAs (7 males and 2 females, 47±9 years old, 1.76±0.1 m 79±17 kg) with a motion analysis system (Qualisys, Goteborg, Sweden), force plates (Kitsler, Winterthur, Switzerland) and a multi-axial transducer (JR3, Woodland, USA) mounted above the prosthetic knee [1-17]. TFAs were all fitted with an osseointegrated implant system. The prostheses included different type of foot (N=5) and knee (N=3) components. The root mean square errors (RMSE) between direct measurements and the knee joint forces and moments estimated by inverse dynamics were computed for stance and swing phases of gait and expressed as a percentage of the measured amplitudes. A one-way Kruskal-Wallis ANOVA was performed (Statgraphics, Levallois-Perret, France) to analyse the effects of the prosthetic components on the RMSEs. Cross-effects and post-hoc tests were not analysed in this study. Results A significant effect (*) was found for the type of prosthetic foot on anterior-posterior force during swing (p=0.016), lateral-medial force during stance (p=0.009), adduction-abduction moment during stance (p=0.038), internal-external rotation moment during stance (p=0.014) and during swing (p=0.006), and flexion-extension moment during stance (p = 0.035). A significant effect (#) was found for the type of prosthetic knee on anterior-posterior force during swing (p=0.018) and adduction-abduction moment during stance (p=0.035). Discussion & Conclusion The RMSEs were larger during swing than during stance. It is because the errors on accelerations (as derived from motion analysis) become substantial with respect to the external loads. Thus, inverse dynamics during swing should be analysed with caution because the mean RMSEs are close to 50%. Conversely, there were fewer effects of the prosthetic components on RMSE during swing than during stance and, accordingly, fewer effects due to knees than feet. Thus, inverse dynamics during stance should be used with caution for comparison of different prosthetic components.

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At Purdue University, the Libraries participate in a provost-initiated, campus-wide course redesign program called Instruction Matters: Purdue Academic Course Transformation (IMPACT). This initiative aims to bring active-learning to foundational courses traditionally taught through lectures. Purdue librarians recognized the IMPACT initiative as one way to enter the conversations blooming on our campus about the nature of learning, curriculum design, and how space design impacts potential learning. This article presents three perspectives: 1) the information literacy coordinator, 2) a libraries’ administrator with a gift for space planning, and; 3) an in-the-trenches liaison to course redesign projects. Each discusses the IMPACT initiative from his or her unique perspective and view of its impact on librarian roles. Collectively, the article explains why we think it is essential that this kind of campus effort is supported by libraries.

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Objectives: The incidence and mortality of traumatic brain injury (TBI) has increased rapidly in the last decade in China. Appropriate ambulance service can reduce case-fatality rates of TBI significantly. This study aimed to explore the factors (age, gender, education level, clinical experience, professional title, organization, specialty before prehospital care, and training frequency) that could influence prehospital doctors’ knowledge level and practices in TBI management in China, Hubei Province. Methods: A cross-sectional questionnaire survey was conducted in two cities in Hubei Province. The self-administered questionnaire consisted of demographic information and questions about prehospital TBI management. Independent samples t-test and one-way ANOVA were used to analyze group differences in the average scores in terms of demographic character. General linear regression was used to explore associated factors in prehospital TBI management. Results: A total of 56 questionnaires were handed out and 52 (93%) were returned. Participants received the lowest scores in TBI treatment (0.64; SD=0.08) and the highest scores in TBI assessment (0.80; SD=0.14). According to the regression model, the education level was associated positively with the score of TBI identification (P=.019); participants who worked in the emergency department (ED; P=.011) or formerly practiced internal medicine (P=.009) tended to get lower scores in TBI assessment; participants’ scores in TBI treatment were associated positively with the training frequency (P=.011); and no statistically significant associated factor was found in the overall TBI management. Conclusion: This study described the current situation of prehospital TBI management. The prehospital doctors’ knowledge level and practices in TBI management were quantified and the influential factors hidden underneath were explored. The results indicated that an appropriate continuing medical education (CME) program enables improvement of the quality of ambulance service in China.