The dynamics of the impact and coalescence of droplets on a solid surface

A simple experimental setup to study the impact and coalescence of deposited droplets is described. Droplet impact and coalescence have been investigated by high-speed particle image velocimetry. Velocity fields near the liquid-substrate interface have been observed for the impact and coalescence of 2.4 mm diameter droplets of glycerol∕water striking a flat transparent substrate in air. The experimental arrangement images the internal flow in the droplets from below the substrate with a high-speed camera and continuous laser illumination. Experimental results are in the form of digital images that are processed by particle image velocimetry and image processing algorithms to obtain velocity fields, droplet geometries, and contact line positions. Experimental results are compared with numerical simulations by the lattice Boltzmann method.     

Effects of cold water immersion on the recovery of physical performance and muscle damage following a one-off soccer match

The aim of this study was to assess the effects of a single session of cold or thermoneutral water immersion after a one-off match on muscular dysfunction and damage in soccer players. Twenty-male soccer players completed one match and were randomly divided into cryotherapy (10 min cold water immersion, 10°C, n = 10) and thermoneutral (10 min thermoneutral water immersion, 35°C, n = 10) groups. Muscle damage (creatine kinase, myoglobin), inflammation (C-reactive protein), neuromuscular function (jump and sprint abilities and maximal isometric quadriceps strength), and delayed-onset muscle soreness were evaluated before, within 30 min of the end, and 24 and 48 h after the match. After the match, the players in both groups showed increased plasma creatine kinase activity (30 min, 24 h, 48 h), myoglobin (30 min) and C-reactive protein (30 min, 24 h) concentrations. Peak jump ability and maximal strength were decreased and delayed-onset muscle soreness increased in both groups. However, differential alterations were observed between thermoneutral water and cold water immersion groups in creatine kinase (30 min, 24 h, 48 h), myoglobin (30 min), C-reactive protein (30 min, 24 h, 48 h), quadriceps strength (24 h), and quadriceps (24 h), calf (24 h) and adductor (30 min) delayed-onset muscle soreness. The results suggest that cold water immersion immediately after a one-off soccer match reduces muscle damage and discomfort, possibly contributing to a faster recovery of neuromuscular function.     

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.     

Drivers of teachers’ intentions to use mobile applications to teach science

Education and Information Technologies - Using mobile applications in science education has proven to be effective as it adds multiple benefits including learning gains, motivation to learn, and...     

Mexican Immigrant Students' Schooling Experiences and the Construction of Disengagement in Mathematics Learning Contexts

Through an ethnographic and narrative inquiry approach, this study draws attention to the plight of 4 Mexican immigrant high school students and their pursuit of education and mathematics learning. Their elementary school stories and experiences show a deep relationship between the learning contexts in which these students largely do school (i.e., an English learner context) and the nature of students' relationships (or lack thereof) with teachers and their process of disengagement from mathematics learning and school. Doing school is used to convey a key distinction from simply attending school. Attending school assumes uniformity/neutrality in how students might experience schooling and is a passive way of describing student participation in school. Doing school implies that students make sense of and respond to their schooling experiences in different ways and accounts for how these experiences are shaped and/or influenced by other forces (e.g., structural forces, social forces) in and out of school.     

The Power of the Pen: Writing Mentorship and Chicana/o M.A. Students

This article draws on my experience as an adjunct professor in the Master's program of the Department of Mexican-American Studies at a large public university in California. Seeing my students’ struggles with writing, I conceived of a set of practices of writing mentorship anchored by a series of writing workshops held in Summer 2012. In this article, I document the pedagogy and content of these writing workshops in order to think about the unique struggles and opportunities Chicana/o Master's students face in the writing process and to provide an outline for other instructors interested in developing a practice of writing mentorship.     

Developing an audiovisual notebook as a self‐learning tool in histology: Perceptions of teachers and students

Videos can be used as didactic tools for self‐learning under several circumstances, including those cases in which students are responsible for the development of this resource as an audiovisual notebook. We compared students' and teachers' perceptions regarding the main features that an audiovisual notebook should include. Four questionnaires with items about information, images, text and music, and filmmaking were used to investigate students' (n = 115) and teachers' perceptions (n = 28) regarding the development of a video focused on a histological technique. The results show that both students and teachers significantly prioritize informative components, images and filmmaking more than text and music. The scores were significantly higher for teachers than for students for all four components analyzed. The highest scores were given to items related to practical and medically oriented elements, and the lowest values were given to theoretical and complementary elements. For most items, there were no differences between genders. A strong positive correlation was found between the scores given to each item by teachers and students. These results show that both students' and teachers' perceptions tend to coincide for most items, and suggest that audiovisual notebooks developed by students would emphasize the same items as those perceived by teachers to be the most relevant. Further, these findings suggest that the use of video as an audiovisual learning notebook would not only preserve the curricular objectives but would also offer the advantages of self‐learning processes. Anat Sci Educ 7: 209–218. © 2013 American Association of Anatomists.     

Beyond Punnett Squares: Student Word Association and Explanations of Phenotypic Variation through an Integrative Quantitative Genetics Unit Investigating Anthocyanin Inheritance and Expression in Brassica rapa Fast Plants

Genetics instruction in introductory biology is often confined to Mendelian genetics and avoids the complexities of variation in quantitative traits. Given the driving question “What determines variation in phenotype (Pv)? (Pv=Genotypic variation Gv + environmental variation Ev),” we developed a 4-wk unit for an inquiry-based laboratory course focused on the inheritance and expression of a quantitative trait in varying environments. We utilized Brassica rapa Fast Plants as a model organism to study variation in the phenotype anthocyanin pigment intensity. As an initial curriculum assessment, we used free word association to examine students’ cognitive structures before and after the unit and explanations in students’ final research posters with particular focus on variation (Pv = Gv + Ev). Comparison of pre- and postunit word frequency revealed a shift in words and a pattern of co-occurring concepts indicative of change in cognitive structure, with particular focus on “variation” as a proposed threshold concept and primary goal for students’ explanations. Given review of 53 posters, we found ∼50% of students capable of intermediate to high-level explanations combining both Gv and Ev influence on expression of anthocyanin intensity (Pv). While far from “plug and play,” this conceptually rich, inquiry-based unit holds promise for effective integration of quantitative and Mendelian genetics.