Molecular diffusion analysis of dynamic blood flow and plasma separation driven by self-powered microfluidic devices     

Sung Oh Woo  Myungkeun Oh  Kyle Nietfeld  Bailey Boehler  Yongki Choi 《Biomicrofluidics》2021,15(3)

Integration of microfluidic devices with pressure-driven, self-powered fluid flow propulsion methods has provided a very effective solution for on-chip, droplet blood testing applications. However, precise understanding of the physical process governing fluid dynamics in polydimethylsiloxane (PDMS)-based microfluidic devices remains unclear. Here, we propose a pressure-driven diffusion model using Fick''s law and the ideal gas law, the results of which agree well with the experimental fluid dynamics observed in our vacuum pocket-assisted, self-powered microfluidic devices. Notably, this model enables us to precisely tune the flow rate by adjusting two geometrical parameters of the vacuum pocket. By linking the self-powered fluid flow propulsion method to the sedimentation, we also show that direct plasma separation from a drop of whole blood can be achieved using only a simple construction without the need for external power sources, connectors, or a complex operational procedure. Finally, the potential of the vacuum pocket, along with a removable vacuum battery to be integrated with non-PDMS microfluidic devices to drive and control the fluid flow, is demonstrated.  相似文献   

Understanding the relative contribution of technical and tactical performance to match outcome in Australian Football     

Christopher M Young  Wei Luo  Paul B Gastin  Daniel B Dwyer 《Journal of sports sciences》2020,38(6):676-681

ABSTRACT

The aim of this study was to assess if tactical and technical performance indicators (PIs) could be used in combination to model match outcomes in Australian Football (AF). A database of 101 technical PIs and 14 tactical PIs from every match in the 2009–2016 Australian Football League (AFL) seasons was merged. Two outcome measures Win-loss and Score margin were used as dependent variables. The top 45 ranked technical and tactical PIs from a feature selection process were used to model match outcome using decision tree and Generalised Linear Models (GLMs). Of the top 45 selected features, this included seven tactical PIs. The Win-loss-based Decision tree model achieved a classification accuracy of 89.0% and GLM 93.2%. A Score margin-based GLM achieved a root mean squared error (RMSE) of 6.9 points. A combined approach to the classification of match outcomes provided no improvement in model accuracy compared with previous literature. However, this study has established the relative importance of technical and tactical measures of performance in relation to successful team performance in AF.  相似文献   

The Developmental Sequence and Relations Between Gesture and Spoken Language in Toddlers With Autism Spectrum Disorder     

Meagan R. Talbott  Gregory S. Young  Jeff Munson  Annette Estes  Laurie A. Vismara  Sally J. Rogers 《Child development》2020,91(3):743-753

In typical development, gestures precede and predict language development. This study examines the developmental sequence of expressive communication and relations between specific gestural and language milestones in toddlers with autism spectrum disorder (ASD), who demonstrate marked difficulty with gesture production and language. Communication skills across five stages (gestures, word approximations, first words, gesture-word combinations, and two-word combinations) were assessed monthly by blind raters for toddlers with ASD participating in an randomized control trial of parent-mediated treatment (N = 42, 12–30 months). Findings revealed that toddlers acquired skills following a reliable (vs. idiosyncratic) sequence and the majority of toddlers combined gestures with words before combining words in speech, but in contrast to the pattern observed in typical development, a significant subset acquired pointing after first words.  相似文献   

Child Effects on Parental Negativity: The Role of Heritable and Prenatal Factors     

Chang Liu  Linying Ji  Sy-Miin Chow  Boyoung Kang  Leslie D. Leve  Daniel S. Shaw  Jody M. Ganiban  Misaki N. Natsuaki  David Reiss  Jenae M. Neiderhiser 《Child development》2020,91(5):e1064-e1081

This study examined two possible mechanisms, evocative gene–environment correlation and prenatal factors, in accounting for child effects on parental negativity. Participants included 561 children adopted at birth, and their adoptive parents and birth parents within a prospective longitudinal adoption study. Findings indicated child effects on parental negativity, such that toddlers’ negative reactivity at 18 months was positively associated with adoptive parents’ over-reactive and hostile parenting at 27 months. Furthermore, we found that child effects on parental negativity were partially due to heritable (e.g., birth mother [BM] internalizing problems and substance use) and prenatal factors (e.g., BM illicit drug use during pregnancy) that influence children’s negative reactivity at 18 months. This study provides critical evidence for “child on parent” effects.  相似文献   

国外知识组织体系管理工具比较分析与启示     

纪姗姗  赵炳容  刘峥 《图书情报工作》2021,64(24):73-83

[目的/意义] 比较分析语义网技术发展环境下国外代表性知识组织体系管理工具的研究现状及关键功能，梳理相关研究的发展趋势。[方法/过程] 通过网络调研法，遴选国外10个代表性知识组织体系管理工具，从结构定义、项目维护、数据管理、互操作性、操作环境等方面比较分析其发展现状。在此基础上，为国内知识组织体系管理工具的建设工作提供建议。[结果/结论] 研究发现，国内知识组织体系管理工具的建设工作应依托语义网、关联数据、语义集成、语义互操作等技术促进功能创新，包括：灵活设计并配置多类型数据模型、支持可持续发展的管理与维护机制、支持用户分布式协同管理与控制、知识驱动的数据迭代式更新、面向语义的KOS重用与进化、建设以KOS为核心的知识组织框架等。  相似文献   

The education of academically gifted students in South Korea: Innovative approaches in shadow education     

Young Chun Kim  Jaeseong Jo  Jung-Hoon Jung 《European Journal of Education》2020,55(3):376-387

Shadow education contributes to the learning and academic careers of Korean students. It benefits, in particular, gifted students who are strongly motivated and who outperform their peers academically. In this study, we explored the innovative characteristics of shadow education curricula for gifted students in terms of curricular programmes, methods, and teaching-learning materials. Also, we explored how shadow education practices meet the academic abilities and needs of students. Informed by a literature review and qualitative research methods, the results reveal how common shadow education is; effects of shadow education; and innovative elements used in shadow education for gifted students in Korea. Overall, we found that shadow education plays a crucial role in gifted education; it is a necessary component for understanding academic excellence among students in Korea. The findings are helpful for teachers, curriculum developers, and policymakers as they explore how public schooling can help to support strongly motivated and academically advanced students.  相似文献   

Parental perceptions of gender differences in child technology use and cyberbullying     

Mallory Bolenbaugh  Megan Foley-Nicpon  Rachel Young  Melissa Tully  Nikki Grunewald  Marizen Ramirez 《Psychology in the schools》2020,57(11):1657-1679

Cyberbullying is a major health concern for today's youth and a pervasive stressor for adolescents and their families. This study offers qualitative insights into how parents perceive their children's technology use and engagement in cyberbullying based on gender. Eight focus groups were conducted with 48 parents of adolescents ages 10–17. Findings indicated parents perceived their children overuse technology and lack awareness of what cyberbullying is. Specific to gender, parents suggested their daughters use technology for social connection, and parents were more concerned about their daughter's technology use than their son's, which they believed was related to specific interests. In response to cyberbullying scenarios, parents encouraged females but not males to socialize with peers. This is the first qualitative study to obtain an in-depth understanding of the ways in which parents perceive and socialize their children in regard to technology use and cyberbullying scenarios. These results may help school systems, school psychologists, researchers, and parents gain awareness of the gender-stereotypical socialization process that unfolds in parental monitoring of technology use and cyberbullying situations. We conclude by offering suggestions for how school systems and personnel might intervene.  相似文献   

开放教育教师知识共享意愿研究     

沈际 《滁州职业技术学院学报》2020,(1):22-25

人在漫长的学习生涯中学习知识,并通过知识共享加速知识积累,开放教育教师所拥有的教学经验是其在长期的教学实践过程中积累的技巧或窍门,他们对知识共享既期待又有顾虑,实现知识共享的技术手段也各有偏好。  相似文献   

Coupled matrix factorization and topic modeling for aspect mining     

Ding Xiao  Yugang Ji  Yitong Li  Fuzhen Zhuang  Chuan Shi 《Information processing & management》2018,54(6):861-873

Aspect mining, which aims to extract ad hoc aspects from online reviews and predict rating or opinion on each aspect, can satisfy the personalized needs for evaluation of specific aspect on product quality. Recently, with the increase of related research, how to effectively integrate rating and review information has become the key issue for addressing this problem. Considering that matrix factorization is an effective tool for rating prediction and topic modeling is widely used for review processing, it is a natural idea to combine matrix factorization and topic modeling for aspect mining (or called aspect rating prediction). However, this idea faces several challenges on how to address suitable sharing factors, scale mismatch, and dependency relation of rating and review information. In this paper, we propose a novel model to effectively integrate Matrix factorization and Topic modeling for Aspect rating prediction (MaToAsp). To overcome the above challenges and ensure the performance, MaToAsp employs items as the sharing factors to combine matrix factorization and topic modeling, and introduces an interpretive preference probability to eliminate scale mismatch. In the hybrid model, we establish a dependency relation from ratings to sentiment terms in phrases. The experiments on two real datasets including Chinese Dianping and English Tripadvisor prove that MaToAsp not only obtains reasonable aspect identification but also achieves the best aspect rating prediction performance, compared to recent representative baselines.  相似文献   

Students’ perceptions of an interdisciplinary global study tour: uncovering inexplicit employability skills     

Rachael Hains-Wesson  Kaiying Ji 《高等教育研究与发展》2020,39(4):657-671

ABSTRACT

For higher education graduates to be effective in the workplace, they require strong technical skills and the capability to operate across diverse knowledge landscapes to solve real world problems. At an Australian university, an interdisciplinary, short-term study tour programme was utilised to enhance students’ inexplicit employability skills with a focus on managing complexity while developing agility and creativity. To investigate the effectiveness of such a programme, we examined students’ perceptions of an interdisciplinary teamwork assessment task that was undertaken in an international context via a study tour model. We achieved this by, first, introducing a purposely designed interdisciplinary teamwork assessment task, which focused on students presenting innovative ideas to peers and industry members. Second, we elicited student responses via a case study approach that incorporated mixed methods, utilising several data collection instruments prior to, during, and after students participated in a study tour. The findings suggest that integrating a purposely designed interdisciplinary teamwork assessment task, via a short-term study tour model, uncovered certain inexplicit employability skills, namely managing complexity, developing agility and creativity. We make specific recommendations to support this insight, contributing to the mobility teaching and learning research field.  相似文献