A microfluidic device for on-chip agarose microbead generation with ultralow reagent consumption

Water-in-oil microdroplets offer microreactors for compartmentalized biochemical reactions with high throughput. Recently, the combination with a sol-gel switch ability, using agarose-in-oil microdroplets, has increased the range of possible applications, allowing for example the capture of amplicons in the gel phase for the preservation of monoclonality during a PCR reaction. Here, we report a new method for generating such agarose-in-oil microdroplets on a microfluidic device, with minimized inlet dead volume, on-chip cooling, and in situ monitoring of biochemical reactions within the gelified microbeads. We used a flow-focusing microchannel network and successfully generated agarose microdroplets at room temperature using the “push-pull” method. This method consists in pushing the oil continuous phase only, while suction is applied to the device outlet. The agarose phase present at the inlet is thus aspirated in the device, and segmented in microdroplets. The cooling system consists of two copper wires embedded in the microfluidic device. The transition from agarose microdroplets to microbeads provides additional stability and facilitated manipulation. We demonstrate the potential of this method by performing on-chip a temperature-triggered DNA isothermal amplification in agarose microbeads. Our device thus provides a new way to generate microbeads with high throughput and no dead volume for biochemical applications.     

Soft approaches to information access on the Web: An introduction to the special issue

Soft Computing (SC) tools present a great potential in real-life problems related with engineering, industrial applications, medicine, finances, etc. In this special issue we present a set of seven papers that report original research about the use of SC techniques to solve the problems in the field of information access on the Web.     

Lessons from new experiences in extension in West Africa: Management advice for family farms and farmers' governance

The emergence of Management Advice for Family Farms in West Africa is closely related to the increased integration of farmers into an open market economy. This is creating a strong demand from farmers for advisory support services, focusing on management of the farm. With the gradual withdrawal of the State from extension services delivery, a stimulating context exists for reviewing approaches and systems of support delivery facilities for producers. In response to these developments, several experiments based on the concepts of Management Advice for Family Farms are going on in West Africa. Beyond a variety of objectives and implementation procedures analysed in this paper, common features and a considerable degree of consensus on concepts emerge. Strengthening the producers' capacity for assessment, decision-making, and management of their farms is a common objective. Differences exist between procedures for delivery of advice, methods, tools used, and emphasis put on different aspects of management. All experiments stress the importance of training, enhancing group dynamics, and individual learning. They are all farmer and farm family targeted. Expression of farmers' objectives, needs, and demands is essential. Advice is based on data gathering and assessment by the farmers themselves. From mere technicians, extension workers become advisors and facilitators. In all cases, Farmers' Organisations are involved in governing the delivery services, though at different degrees. In several cases priority is given towards strengthening farmers' capacity in the management of delivery at both local and global levels. Significant improvements in farm performances have been reported. Cost sharing is generally accepted, but insufficient to cover all costs. However, to reach sustainability for farmers' driven and governed advice delivery services, innovative agricultural policies, and public finance are needed.     

Performance Management in the French System of Secondary-Teacher training

The present study focuses on performance analysis and performance management in teacher training in France. After a brief summary of the French system of secondary-teacher training, determinants affecting performance are analyzed. The analysis shows that three determinants – the number of external competitors, the size of a department and the number of posts to be filled by recruitment examinations – are crucial to the performance of a training department. The analysis reveals, however, that although a department’s performance may be related to its size, efficiency and inefficiency limits have to be taken into account in growth strategies.     

Grades degrade group coordination: deteriorated interactions and performance in a cooperative motor task

At school, pupils often cooperate on common projects and must coordinate their different individual actions. However, grades are pervasively used even in cooperative situations, which make the pupils’ differences in achievement and their relative rank salient and may reduce their inclination to work constructively with others. Thus, we hypothesized that grades would elicit disruptive interactions and reduce performance in a cooperative cognitive-motor task necessitating inter-individual coordination of members. In a study with 5th graders, grades (vs. a neutral concept) were primed at the onset of a cooperative group interaction. Results showed that, although pupils were set to work cooperatively, priming grades (vs. neutral concepts) harmed inter-individual coordination by eliciting more negative dominant behaviours among pupils during interactions, which decreased group performance.     

France: The National Centre for Distance Teaching

University Professor, Chief Education Officer and Director of the Centre National d'Enseignement à Distance (CNED) from December 1985 to December 1987. Author of several works on epistemology, history of science, social problems.     

L’apprentissage précoce des langues : Des pratiques sociologiquement et politiquement marquées

Throughout the world there is a great diversity of curricula for introducing early foreign language training more or less intensively. These curricula correspond to different pedagogical approaches. But these pedagogical choices are not neutral. They are the result of political choice. They are also sociologically discriminatory. The author studies and contrasts various forms of language training of certain countries and within the same countries (for example, the correlation between bilingual training and private schools, or the choice of bilingual education as a political goal). She proposes a scale for classifying the kinds of early foreign language training, depending on sociological criteria and political choice.     

Deboning the Fish: Hosting a Future Creating Workshop with Undergraduate Women in STEM

Innovative Higher Education - Despite the broad scope of literature on the topic of women in STEM, women in male-dominated spaces within academia are rarely given the opportunity to speak openly...     

On not seeing words: Illiteracy and language

Although literacy is realized in particular ways in different cultures, it also has a universal, cognitive dimension: namely, that skilled reading accentuates the distinction between language and meaning. The study of adult non-readers in literate cultures provides supporting evidence for this argument.     

Knowledge acquisition from text: Introduction

European Journal of Psychology of Education -