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21.
Mass transport in porous materials is universal in nature, and its worth attracts great attention in many engineering applications. Plant leaves, which work as natural hydraulic pumps for water uptake, have evolved to have the morphological structure for fast water transport to compensate large water loss by leaf transpiration. In this study, we tried to deduce the advantageous structural features of plant leaves for practical applications. Inspired by the tissue organization of the hydraulic pathways in plant leaves, analogous double-layered porous models were fabricated using agarose hydrogel. Solute transport through the hydrogel models with different thickness ratios of the two layers was experimentally observed. In addition, numerical simulation and theoretical analysis were carried out with varying porosity and thickness ratio to investigate the effect of structural factors on mass transport ability. A simple parametric study was also conducted to examine unveiled relations between structural factors. As a result, the porosity and thickness ratio of the two layers are found to govern the mass transport ability in double-layered porous materials. The hydrogel models with widely dispersed pores at a fixed porosity, i.e., close to a homogeneously porous structure, are mostly turned out to exhibit fast mass transport. The present results would provide a new framework for fundamental design of various porous structures for effective mass transport.  相似文献   
22.
We present an engineered three-dimensional (3D) in vitro brain microvasculature system embedded within the bulk of a collagen matrix. To create a hydrogel template for the functional brain microvascular structure, we fabricated an array of microchannels made of collagen I using microneedles and a 3D printed frame. By culturing mouse brain endothelial cells (bEnd.3) on the luminal surface of cylindrical collagen microchannels, we reconstructed an array of brain microvasculature in vitro with circular cross-sections. We characterized the barrier function of our brain microvasculature by measuring transendothelial permeability of 40 kDa fluorescein isothiocyanate-dextran (Stoke''s radius of ∼4.5 nm), based on an analytical model. The transendothelial permeability decreased significantly over 3 weeks of culture. We also present the disruption of the barrier function with a hyperosmotic mannitol as well as a subsequent recovery over 4 days. Our brain microvasculature model in vitro, consisting of system-in-hydrogel combined with the widely emerging 3D printing technique, can serve as a useful tool not only for fundamental studies associated with blood-brain barrier in physiological and pathological settings but also for pharmaceutical applications.  相似文献   
23.
Many children fail to meet physical activity (PA) guidelines for health benefits. PA behaviours are complex and depend on numerous interrelated factors. The study aims to develop current understanding of how children from low Socio-economic environments within the UK use their surrounding built environments for PA by using advanced technology. The environment was assessed in 96 school children (7–9 years) using global positioning system (GPS) monitoring (Garmin Forerunner, 305). In a subsample of 46 children, the environment and PA were assessed using an integrated GPS and heart rate monitor. The percentage of time spent indoor, outdoor, in green and non-green environments along with time spent in moderate-to-vigorous PA (MVPA) in indoor and outdoor environments were assessed. A 2-by-2 repeated measures analysis of covariance, controlling for body mass index, BF%, assessed the environmental differences. The findings show that 42% of children from deprived wards of Coventry fail to meet PA guidelines, of which 43% was accumulated during school. Children engaged in more MVPA outdoor than indoor environments (P < 0.01) and a greater amount of time was spent in non-green environments (P < 0.01). Increased time outdoors was negatively associated with BF%. In conclusion, outdoor environments are important for health-enhancing PA and reducing fatness in deprived and ethnic children.  相似文献   
24.
Paralympic throwing events for athletes with physical impairments comprise seated and standing javelin, shot put, discus and seated club throwing. Identification of talented throwers would enable prediction of future success and promote participation; however, a valid and reliable talent identification battery for Paralympic throwing has not been reported. This study evaluates the reliability and validity of a talent identification battery for Paralympic throws. Participants were non-disabled so that impairment would not confound analyses, and results would provide an indication of normative performance. Twenty-eight non-disabled participants (13 M; 15 F) aged 23.6 years (±5.44) performed five kinematically distinct criterion throws (three seated, two standing) and nine talent identification tests (three anthropometric, six motor); 23 were tested a second time to evaluate test–retest reliability. Talent identification test–retest reliability was evaluated using Intra-class Correlation Coefficient (ICC) and Bland–Altman plots (Limits of Agreement). Spearman’s correlation assessed strength of association between criterion throws and talent identification tests. Reliability was generally acceptable (mean ICC = 0.89), but two seated talent identification tests require more extensive familiarisation. Correlation strength (mean rs = 0.76) indicated that the talent identification tests can be used to validly identify individuals with competitively advantageous attributes for each of the five kinematically distinct throwing activities. Results facilitate further research in this understudied area.  相似文献   
25.
Reacting to the gradual neoliberalization of the European public art institutional landscape, actors within a number of critical art museums and galleries have attempted to reform their institutions from within through a process that is largely commensurate with Chantal Mouffe's radical political strategy of ‘critique as hegemonic engagement‐with’. This article focuses on Manuel J. Borja‐Villel's attempt to implement such a strategy at the Museu D'Art Contemporani, Barcelona (MACBA) in the early 2000s. Through an examination of two key projects – Las Agencias (The Agencies) (2001) and Com Volem ser Governats? (How do we want to be governed) (2003‐2004) – it considers the efficacy of such an approach. In so doing, it calls into question the public art institution's ability to perform a self‐critique when embedded within the hegemony of the neoliberal order and constrained by bureaucratic institutional limitations. It concludes by noting that Mouffe's strategy of engagement does not give sufficient consideration to the dependence critical public art institutions have on local and national political support and its funding channels, making them extremely susceptible to instrumentalization. In response to this constraint, it makes the recommendation that, rather than curbing their experimentation, these critical actors should embrace the potentially temporary status of their institutions, and intentionally push them to and even beyond their bureaucratic limitations.  相似文献   
26.
E‐learning is increasingly adopted in the workplace for supporting professional development and continuing education; however, in higher education, the use of e‐learning is predominantly used as a tool support teaching. As a relatively new priority for universities, this paper explores what influences its adoption. Challenges identified in the literature include organisational features of universities like faculty autonomy and dispersed academic perspectives. This study, carried out at the University of Warwick, adopted a phenomenological approach and explored participants' perceptions through a series of faculty‐based focus groups and individual interviews. Factors identified as influential to adoption of e‐learning included the institutional infrastructure, staff attitudes and skills, and perceived student expectations. Participants suggested the importance of an institutional strategy targeted at providing sufficient resources and guidance for effective implementation. This strategy needs to be supported by a varied programme of staff development and opportunities for sharing practice among colleagues. In further developing understanding in this area, it would be beneficial to replicate the study with other stakeholder groups (including the leadership team and students) to develop an institutional strategy responsive at all levels of implementation. It would also be valuable to investigate the extent to which these findings are replicated within other workplaces looking to adopt innovation.  相似文献   
27.
As part of their longitudinal investigations of a large cohort with a history of specific language impairment (SLI), Professor Gina Conti-Ramsden and her research team based at the School of Education, University of Manchester, Dr Emma Knox, Dr Nicola Botting and Dr Zoë Simkin report on the changing educational placements and National Curriculum assessment outcomes of 200 children at 11 years. Teacher questionnaires reporting on the Year 6 primary education placements of the sample reveal details about the long-term educational needs of children with SLI.
Furthermore, in exploring the experiences of the sample in the National Curriculum Key Stage 2 tests the present study found that children with SLI perform poorly relative to national expectations of levels of achievement across all tests. At present there are no guidelines for supporting children with SLI in relation to National Curriculum tests and the present data suggests there is an obvious need for these to be developed.  相似文献   
28.
BOOK REVIEW     
  相似文献   
29.
This study explored the role of guilt and shame in early prosocial behavior by extending previous findings that guilt‐ and shame‐like responses can be distinguished in toddlers and, for the first time, examining their associations with helping. Toddlers (n = 32; Mage = 28.9 months) were led to believe they broke an adult's toy, after which they exhibited either a guilt‐like response that included frequently confessing their behavior and trying to repair the toy; or a shame‐like response that included frequently avoiding the adult and seldom confessing or attempting to repair the toy. In subsequent prosocial tasks, children showing a guilt‐like response helped an adult in emotional distress significantly faster and more frequently than did children showing a shame‐like response.  相似文献   
30.
While feedback is widely considered central to student learning, students across the higher education sector commonly report dissatisfaction with the feedback they receive. In contrast, academics often feel they provide quality and informative feedback. This article explores and compares the perceptions of students and academics with regard to feedback practice. The paper presents the results of questionnaire surveys conducted with academics and students at the School of the Built Environment, Liverpool John Moores University. It highlights the perceptions of academics and students with regard to preferences for different types of feedback, timeliness of feedback, students’ engagement and interest in feedback, quality feedback and satisfaction with current practice. The findings indicate a significant discord between staff and students in relation to certain aspects of feedback practice, namely opinions on students’ engagement and interest in feedback, satisfaction with current practice and feedback preference. Similarities in viewpoints were also found in relation to quality feedback.  相似文献   
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