The impact of different types of physical activity on total and regional bone mineral density in young Brazilian athletes

Bone turnover is affected by exercise throughout the lifespan, especially during childhood and adolescence. The objective of this study was to investigate the impact of different sports on total and regional bone mineral density in male Brazilian adolescent athletes. Forty-six adolescents aged 10-18 years participated in the study: 12 swimmers, 10 tennis players, 10 soccer players, and 14 sedentary individuals. The athletes had engaged in physical activities for more than 10 h per week in the previous 6 months. Bone mineral density of the lumbar spine (L1-L4), left proximal femur region, and whole body was evaluated by dual-energy X-ray absorptiometry. Results showed higher mean values in the proximal femur region of tennis and soccer players (1.02 ± 0.18; 0.96 ± 0.16, respectively) than swimmers and controls (0.91 ± 0.14 and 0.87 ± 0.06, respectively) (P < 0.05). In relation to the impact of sporting activities based on bone age determination, we observed significant differences in bone mineral density at all evaluated sites at the end of puberty (16-18 years) compared with 10-12 years, with increases of 78% in the lumbar spine, 47% in the proximal femur, and 38% in the whole body.     

Navigating implementation dilemmas in technology-forcing policies: A comparative analysis of accelerated smart meter diffusion in the Netherlands,UK, Norway,and Portugal (2000-2019)

This paper addresses the implementation of technology-forcing policies in open-ended diffusion processes that involve companies and regulators as well as consumers and civil society actors. Mobilising insights from the societal embedding of technology framework and policy steering theories, we investigate two implementation dilemmas that relate to an overarching tension between flexibility (to enable technological learning and stakeholder engagement) and coordinated push (to focus actors and drive deployment): a) early or late formulation of initial targets, and b) technocratic or emergent-adaptive implementation styles. We investigate these dilemmas with four comparative case studies of smart electricity meters between 2000 to 2019, which diffused rapidly in the Netherlands, Norway, and Portugal, but decelerated in the UK. We relate these differences to policy choices, and identify two patterns for successful implementation of technology-forcing policies: a) start with early targets and a technocratic style, but make adjustments if there are substantial protests or technical problems, and b) start with an emergent-adaptive style and formulate and enforce targets later, once technical and social stabilisation has occurred.     

Separation and enrichment of sodium-motile bacteria using cost-effective microfluidics

Many motile bacteria are propelled by the rotation of flagellar filaments. This rotation is driven by a membrane protein known as the stator-complex, which drives the rotor of the bacterial flagellar motor. Torque generation is powered in most cases by proton transit through membrane protein complexes known as stators, with the next most common ionic power source being sodium. Sodium-powered stators can be studied through the use of synthetic chimeric stators that combine parts of sodium- and proton-powered stator proteins. The most well studied example is the use of the sodium-powered PomA-PotB chimeric stator unit in the naturally proton-powered Escherichia coli. Here we designed a fluidics system at low cost for rapid prototyping to separate motile and non-motile populations of bacteria while varying the ionic composition of the media and thus the sodium-motive force available to drive this chimeric flagellar motor. We measured separation efficiencies at varying ionic concentrations and confirmed using fluorescence that our device delivered eightfold enrichment of the motile proportion of a mixed population. Furthermore, our results showed that we could select bacteria from reservoirs where sodium was not initially present. Overall, this technique can be used to implement the selection of highly motile fractions from mixed liquid cultures, with applications in directed evolution to investigate the adaptation of motility in bacterial ecosystems.     

Bandpass sorting of heterogeneous cells using a single surface acoustic wave transducer pair

Separation and sorting of biological entities (viruses, bacteria, and cells) is a critical step in any microfluidic lab-on-a-chip device. Acoustofluidics platforms have demonstrated their ability to use physical characteristics of cells to perform label-free separation. Bandpass-type sorting methods of medium-sized entities from a mixture have been presented using acoustic techniques; however, they require multiple transducers, lack support for various target populations, can be sensitive to flow variations, or have not been verified for continuous flow sorting of biological cells. To our knowledge, this paper presents the first acoustic bandpass method that overcomes all these limitations and presents an inherently reconfigurable technique with a single transducer pair for stable continuous flow sorting of blood cells. The sorting method is first demonstrated for polystyrene particles of sizes 6, 10, and 14.5 μm in diameter with measured purity and efficiency coefficients above 75 ± 6% and 85 ± 9%, respectively. The sorting strategy was further validated in the separation of red blood cells from white blood cells and 1 μm polystyrene particles with 78 ± 8% efficiency and 74 ± 6% purity, respectively, at a flow rate of at least 1 μl/min, enabling to process finger prick blood samples within minutes.     

Optimum calibration of a parallel kinematic manipulator using digital indicators

This paper presents a calibration method for parallel manipulators using a measurement system specially installed on an external fixed frame. The external fixed frame is important as an error reference for calibration in certain operations, such as in the configuration of a parallel manip- ulator functioning as a machine tool where the workpiece is fixed to a worktable. The pose of the end-effector is mea- sured using three digital indicators installed on the external fixed frame. To enable measurement, the end-effector is assumed to be a plane large enough that all digital indicators could touch. The error is defined as the difference between the theoretical and actual readings of the digital indicators. The geometric parameters of the parallel manipulator are optimized to minimize this error. This calibration method is low cost and feasible for compensating geometric parameter errors for a parallel manipulator. Optimal pose selection for the calibration is achieved using a swarm intelligence search algorithm. The method is implemented on a prototype of a six degrees-of-freedom （DOFs） Gough-Stewart platform constructed to function as a machine tool.     

Public libraries embrace citizen science: Strengths and challenges

Can public libraries become hubs for citizen science? In line with the principles of citizen science, this question was answered collaboratively with librarians from the Barcelona Network of Public Libraries who performed two hands-on activities. One activity was a training course taken by 30 librarians from 24 different libraries which enabled them to envisage citizen science implementation at each library. The other activity consisted of co-creating a citizen social science project and involved 40 library users, seven librarians from three different cities, and professional scientists. The analysis considers the perspectives of both librarians and users, through participant observation, surveys, and a focus group to identify strengths and challenges. The overall results suggest that public libraries can offer leadership in the promotion of citizen science and contribute to the mission of public libraries to act as local community hubs. The main challenges identified were related to the complexity of collaboration, uncertainty regarding research co-creation, and participant retention strategies.     

Citizen reactions to municipalities’ Instagram communication

In this paper, we explore how local governments are using Instagram as a communication tool to engage with their citizens, using data from the municipalities of Andalusia (Spain). We seek to identify the determinants of local government use of Instagram, the determinants of activity in this channel and the determinants of citizen reactions in order to understand the influence of media types (picture, video or album) used in municipality posts, and to understand content type (what the post is about). Instaloader, an open source intelligence (OSINT) tool for Instagram, was applied. It made it possible to automatically extract all posts of the analysed municipalities (14,742 posts). These were later automatically analysed using R, an open source software. It was determined that of the 29 Andalusian local governments with the highest populations, only those that maintain an account on Instagram, totalling 17 municipalities (58.62%), would be part of the final analysis. Our findings demonstrate that when local governments have a high level of debt, they do not maintain and actively use Instagram accounts. We also found that quality of posts’ content is more important than quantity of followers, since there is no significant relationship between citizen reactions and the number of inhabitants of a municipality or the number of followers (audience), while there is a significant negative relationship between the number of posts (activity) and reactions. Our results also highlight that the level of reactions can be stimulated by certain media and content types.     

Implementation of the flipped classroom and its longitudinal impact on improving academic performance

Educational technology research and development - The objective has been to know the impact of the flipped classroom methodology on the academic performance of students during their training...     

Evaluation of the level of problem solving skills of Turkish higher education graduates in technology-rich environments

Educational technology research and development - This study aims to evaluate the level of Turkish higher education graduates’ problem-solving skills (PSSs) in technology-rich environments...