Hematocrit and flow rate regulate the adhesion of platelets to von Willebrand factor

Primary hemostasis and blood clotting is known to be influenced by the red blood cell volume fraction (hematocrit) in blood. Depressed or elevated levels of red blood cells can lead to vascular perfusion problems ranging from bleeding to thrombus formation. The early stage of hemostasis and thus blood clotting in all vessel sections from the arterial to the venous system involves the adhesion of platelets to von Willebrand factor. Here we present experimental and theoretical results showing that the adhesion probability of platelets to von Willebrand factor is strongly and nonlinearly dependent on hematocrit and flow rate. Interestingly, the actual binding forces are not markedly different, which suggest that the origin of such behavior is in the distribution of platelets. Using hydrodynamic simulations of a simple model, we explicitly show that the higher the hematocrit and the flow rate, the larger the amount of platelets residing close to the wall. Our simulation results, which are in excellent agreement with the experimental observations, explain why such phenomena occur. We believe that the nonhomogeneous red blood cell distribution as well as the shear dependent hydrodynamic interaction is key for the accumulation of platelets on the vessel wall. The work we present here is an important step forward from our earlier work on single molecules and extends into the collective cellular behavior of whole blood. It sheds new light on the correlation between hematocrit and the initial steps in hemostasis and thrombosis, and outlines advances for the treatment of vascular diseases associated with high levels of red blood cells. These results are not only highly relevant for the field of hemostasis and the physics of blood clotting but are also of powerful impact in applied science most obviously in drug delivery and colloidal science.     

What they learn when they learn coding: investigating cognitive domains and computer programming knowledge in young children

Educational technology research and development - Computer programming for young children has grown in popularity among both educators and product developers, but still relatively little is known...     

Games to Improve Students Information Literacy Skills

Abstract

As digital natives enter higher education, there is the need to improve their information skills but they often overestimate their information research skills and are unfamiliar with the library. The serious games give the opportunity for innovative and engaging approaches to information literacy learning. The paper describes NAVIGATE - Information Literacy: a Game-based Learning Approach for Avoiding Fake Content, a project funded by Erasmus?+?program. The Project aims to improve the competences to avoid fake content of the higher education students in the Humanities. The paper focuses on the comparative analysis of the students’ skills gap and the difficulty of actually assessing the learning improvement achieved by games, highlighting the lessons learned and the open issues.     

The effects of R&D tax credits on patenting and innovations

Norwegian business spending on R&D is low by OECD standards. To stimulate business R&D, in 2002 the Norwegian government introduced a tax-based incentive, SkatteFUNN. We analyze the effects of SkatteFUNN on the likelihood of innovating and patenting. Using a rich database for Norwegian firms, we find that projects receiving tax credits result in the development of new production processes and to some extent the development of new products for the firm. Firms that collaborate with other firms are more likely to be successful in their innovation activities. However, the scheme does not appear to contribute to innovations in the form of new products for the market or patenting.     

Situational interest,cognitive engagement,and achievement in physical education

Students’ learning has been the center of schooling. This study examined the contribution of situational interest motivation and cognitive engagement in workbooks to student achievement in learning health-related fitness knowledge. Situational interest, performance on solving workbook problems, and knowledge gain in cardio-respiratory fitness and benefits were measured in 670 third-grade students from 13 randomly selected urban elementary schools. Structural equation modeling and regression curve estimation analyses revealed that situational interest contributed little to workbook performance and knowledge gain. Performance on solving workbook problems contributed significantly to knowledge gain. The results also show that skipping workbook tasks had stronger negative impact on knowledge gain than performing the tasks incorrectly, suggesting the importance of engaging students in the learning process by attempting the workbook tasks. The findings reinforced the value of using workbooks to facilitate cognitive knowledge learning in physical education, but raised questions about the direct function of situational interest on engaging students in cognitive learning.     

E-learning and Evaluation in Modern Educational System

Implementation of information and communication technologies as well as emersion of new user interfaces and web 2.0 technologies changes the way of education system, the way of living and business transactions in general. The way we communicate, operate, produce and live is also changing. In accordance with it, the systems of education change from traditional to modern. The following changes occur： from content delivery to knowledge production, from transfer of knowledge from teachers to students towards encouragement of development and construction of knowledge, from courses and programs changing to the adaptation of the study environment, from the faculty professionalism to the quality of teaching and student learning and the early involvement of students in research work and projects. These occurring changes also affect the students＇ and professors＇ mobility. Here, the word ＂mobility＂ represents not only the student exchange programs and the easier transitions from one＇s home university to a foreign one, but also the way professors conduct their classes. With the development of certain software, students＇ class attendance no longer represents an important factor, as they can now learn from distance using the mentioned software, taking the learning process one step further. In order for above-mentioned changes to occur, the use of e-learning and the development of new tools are almost mandatory. With this in mind, the goal of this paper is to analyze quantitatively the changes that are occurring almost every day that affect the students＇ learning and the professors＇ teaching methods.