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   

Elizabeth A. Segal,Karen E. Gerdes,Cynthia A. Lietz,M. Alex Wagaman,and Jennifer M. Geiger. (2017). Assessing Empathy. New York,NY: Columbia University Press (179 pp., $30.00, paperback,ISBN# 978-0231181914)     

Darlyne Bailey  Corrie Tice 《Journal of Teaching in Social Work》2018,38(1):106-109

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Validation of a videogrammetry technique for analysing American football helmet kinematics     

Ann Bailey  James Funk  David Lessley  Chris Sherwood  Jeff Crandall  William Neale 《Sports biomechanics / International Society of Biomechanics in Sports》2020,19(5):678-700

ABSTRACT

Professional American football games are recorded in digital video with multiple cameras, often at high resolution and high frame rates. The purpose of this study was to evaluate the accuracy of a videogrammetry technique to calculate translational and rotational helmet velocity before, during and after a helmet impact. In total, 10 football impacts were staged in a National Football League (NFL) stadium by propelling helmeted 50th percentile male crash test dummies into each other or the ground at speeds and orientations representative of concussive impacts for NFL players. The tests were recorded by experienced sports film crews to obtain video coverage and quality typically available for NFL games. A videogrammetry procedure was used to track the position and rotation of the helmet throughout the relevant time interval of the head impact. Compared with rigidly mounted retroreflective marker three dimensional (3-D) motion tracking that was concurrently collected in the experiments, videogrammetry accurately calculated changes in translational and rotational velocity of the helmet using high frame rate (two cameras at 240 Hz) video (7% and 15% error, respectively). Low frame rate (2 cameras at 60 Hz) video was adequate for calculating pre-impact translational velocity but not for calculating the translational or rotational velocity change of the helmet during impact.  相似文献   

Oral History Interview of PCC Founding     

David Reser  Jeanne Drewes  Ann Della Porta 《Cataloging & classification quarterly》2020,58(3-4):239-247

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Building student-teacher relationships and improving behaviour-management for classroom teachers     

Jordan Yassine  Leigh Ann Tipton-Fisler  Barbara Katic 《Support for Learning》2020,35(3):389-407

Teachers can at times view behavioural intervention procedures as time-consuming. Thus, socially-valid classroom-based interventions are a critical component to behavioural success. This study examined the effects of traditional behavioural interventions with two kindergarten students presenting with challenging behaviours, including aggression, tantrums and noncompliance. Notably, it was found that traditional behavioural procedures were not sufficient to substantially reduce the behaviours alone. Therefore, a relationship-building component was added to target positive student-teacher relationships. Student outcomes resulted in a significant reduction in challenging behaviour as well as teacher-reported behaviours showing a reduction across all measured periods. Ongoing teacher consultation, increased student-teacher relationships (STRs) and use of effective classroom management strategies are necessary for effective models of behaviour support.  相似文献   

Recipes for fun     

Ann Cole  Carolyn Haas  Elizabeth Heller  Betty Weinberger 《Early Childhood Education Journal》1975,2(4):39-42

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Investigating Students’ Learning Through Co-designing with Technology     

Wu  Jue  Atit  Kinnari  Ramey  Kay E.  Flanagan-Hall  Grace Ann  Vondracek  Mark  Jona  Kemi  Uttal  David H. 《Journal of Science Education and Technology》2021,30(4):529-538

Involving students in the co-design of educational curricula and practices can benefit both students and teachers. Students who participate in co-design may show better learning or increased agency or engagement. In the present study, we investigated what kind of science knowledge or practices can be learned by student co-designers while engaging in co-design practices and how that learning happens with six high school students. We created a model to guide the analysis of students’ learning with technology in co-designing processes. The results revealed that students learned engineering design process even if no explicit instruction on engineering learning was given. Also, our analysis suggested that co-designing with technology enabled learning of the engineering design process and potentially furthered learning of science because it promoted knowledge integration. The results have implications for understanding and enhancing engineering design and science learning through co-designing with technology.

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Professional Cultures and Collaborative Efforts: A Case Study of Technologists and Educators Working for Change     

Ann Locke Davidson  Janet Schofield  Janet Stocks 《The Information Society》2001,17(1):21-32

The need for those working in a variety of settings to interact effectively with technical experts has grown dramatically in recent years as computers have become essential to the performance of an increasing broad range of professional work. This article presents a case of this sort of interprofessional interaction, exploring the process and outcomes of collaboration between technical professionals and educators working to bring Internet access to an urban public school district. Drawing on field note and interview data, the case reported here illustrates how differences in institutional routines and professional values can generate differing agendas, contrasting assumptions, and contrasting expectations concerning project products and outcomes among collaborators from different professional worlds. In the case we describe, these differences affected such central matters as the types and usefulness of technical resources to which users had access as well as users' confidence in the technology. The case also illustrates how aspects of this interprofessional conflict were addressed through an organizational change. The kinds of issues that arose in this project are likely to occur in a variety of professional settings; therefore, examination of this case provides insight into a variety of issues and dynamics that should be considered when embarking upon or analyzing any interprofessional collaborative effort, and particularly one that involves technical professionals.  相似文献   

Academic Care: Building Resilience, Building Futures   总被引：1，自引：0，他引：1  

Ann J. Nadge 《Pastoral Care in Education》2005,23(1):28-33

In this article, the author explores the ways in which several schools in the New South Wales Independent sector have created learning teams to develop the pastoral capacity of schools. The focus of the work in schools, through the Community Change Project, has been on learning and psycho-social development as the domain of all teachers, in all classrooms. The project has led to the development of the notion of Academic Care. Academic Care involves enhancing student learning and well-being through pedagogies and processes that are sympathetic to student needs and embedded in learning experiences.  相似文献   

Congruence between Mothers' and Fathers' Differential Treatment of Siblings: Links with Family Relations and Children's Well-Being   总被引：2，自引：1，他引：2  

Susan M. McHale  Ann C. Crouter  Shirley A. McGuire  Kimberly A. Updegraff 《Child development》1995,66(1):116-128

We studied patterns of mothers' and fathers' differential treatment of firstborn (average age 10.5 years) and secondborn (average age 8 years) school-age siblings, and we examined the links between parents' differential treatment and children's well-being and dyadic family relationships. Mothers, fathers, and both siblings in 110 families were interviewed in their homes. For each dimension of parental behavior that we assessed (i.e., differential affection and discipline) we created groups of families that reflected mothers' and fathers' levels of differential treatment (e.g., discipline the firstborn more, equal treatment, discipline the secondborn more). Although we detected substantial correspondence between the 2 parents' differential treatment, we found a sizable group of families in which parents' reports were incongruent (i.e., 1 parent reported equal and the other differential treatment). Parental patterns were linked to differences between the siblings' well-being and both sibling and parent-child relationships, with younger siblings exhibiting greater vulnerability to differential treatment. Incongruence in differential warmth was associated with marital distress.  相似文献