Cytocompatible cellulose nanofibers from invasive plant species Agave americana L. and Ricinus communis L.: a renewable green source of highly crystalline nanocellulose

In this study, the fibers of invasive species Agave americana L. and Ricinus communis L. were successfully used for the first time as new sources to produce cytocompatible and highly crystalline cellulose nanofibers. Cellulose nanofibers were obtained by two methods, based on either alkaline or acid hydrolysis. The morphology, chemical composition, and crystallinity of the obtained materials were characterized by scanning electron microscopy(SEM) together with energy-dispersive X-ray spectroscopy(EDX), dynamic light scattering(DLS), X-ray diffraction(XRD), and Fourier transform infrared(FTIR)spectroscopy. The crystallinity indexes(CIs) of the cellulose nanofibers extracted from A. americana and R. communis were very high(94.1% and 92.7%, respectively). Biological studies evaluating the cytotoxic effects of the prepared cellulose nanofibers on human embryonic kidney 293 T(HEK293 T) cells were also performed. The nanofibers obtained using the two different extraction methods were all shown to be cytocompatible in the concentration range assayed(i.e., 0-500 μg/mL). Our results showed that the nanocellulose extracted from A. americana and R. communis fibers has high potential as a new renewable green source of highly crystalline cellulose-based cytocompatible nanomaterials for biomedical applications.     

The development of analogical reading in Spanish

The use and development of analogical processes in learning to read in Spanish are presented. In the first experiment, the results show that children of 6 years old show analogical effects in reading pseudowords and that the magnitude of this effect is the same as with 10 years old children. However, it is found that children of 10 years old make many lexicalizations when reading pseudowords (about 50% of the items). In experiment 2 this finding is further analyzed. The results show that 9 years old children make more lexicalizations than adult control subjects do. It is suggested that the development of analogical procedures is a fast process (6 years old children already have done it), but that the precise control of lexical information over perceptual one is a later process.     

Chebyshev polynomial solutions of systems of higher-order linear Fredholm-Volterra integro-differential equations

A Chebyshev collocation method, an expansion method, has been proposed in order to solve the systems of higher-order linear integro-differential equations. This method transforms the IDE system and the given conditions into the matrix equations via Chebyshev collocation points. By merging these results, a new system which corresponds to a system of linear algebraic equations is obtained. The solution of this system yields the Chebyshev coefficients of the solution function. Some numerical results are also given to illustrate the efficiency of the method. Moreover, this method is valid for the systems of differential and integral equations.     

Going to action? A literature review on educational proposals in formal Environmental Education

The current state of the planet’s environmental deterioration calls for formal educational contexts to implement effective environmental proposals which nurture action competence. The aim of this paper is to examine the educational proposals in formal contexts that have been published in the two research journals of greatest impact on Environmental Education during the period 2008–2013, and to analyse how they contribute to the development of action competence. Special attention is paid to research (i) based on real participation by students; (ii) promotes reflection on the complexity of environmental issues; (iii) facilitates critical thinking; (iv) encourages autonomous and responsible decision-making and (v) involves communities. Our results show that these approaches can help improve the development of action-focused environmental education and bring to light a series of challenges for future research.     

The relationship between teachers’ emotional intelligence and classroom discipline management

One of the fundamental problems of educational systems in many countries is related to classroom discipline. This reflects one of the worst problems faced by teachers. Classroom discipline management strategies play an effective role in creating positive teacher‐student relationships. One of the factors that influence behavior management in a classroom is emotional intelligence. Therefore, this study analyzing how teachers emotional intelligence influences the management of discipline in a classroom and the relationship between gender, academic formation, and service time of teachers with their emotional intelligence. Its sample comprises 559 basic and secondary school teachers. An Emotional Competence Questionnaire, a Scale of Teacher Efficacy in Classroom Management, and a personal and professional data inquiry have been used as instruments. Results show that teachers who have more capacity to deal with emotion demonstrate a greater management of discipline in the classroom. Most of the relationships in the model are statistically significant.     

Performing mundane materiality: Actor-Network Theory,global student mobility and a re/formation of ‘social capital’

ABSTRACT

Social capital is a puzzling actor; made real by its allies. It has been ‘out-there’ in the form of scientific publications for decades. Although some characteristics are common to all elaborations of this theory (networks, trust, and norms), there remains confusion in determining a ‘coherent concept’ of social capital. In this paper, we make use of such ‘incoherence gap’ to open an experimental theoretical and, subsequently, analytical space. Based on empirical research with mobile students and assemblages of non-human actors, the paper offers two investigative gatherings. First, the Bourdieusian approach to ‘social capital’ is discussed, allowing relational ontologies to enter the scene. Second, consideration is given to issues of performativity and the relevance of materiality for empirical social capital investigations. Despite the degree of ontological security social capital has managed to achieve, we question the disregard for the performative role of non-human entities in the context of global student mobility.     

Teamwork and Entrepreneurial Behavior among K-12 Teachers in the United States

Abstract

This study attempted to identify the predictors of entrepreneurial behavior by assessing a series of variables that included teamwork skills and demographic variables, and to explore teachers’ experiences with teamwork. A sample of 367?K-12 public school teachers completed the survey. The findings indicated that teamwork predicts entrepreneurial behavior. Most participants received teamwork training through their school districts. Barriers to teamwork included time constraints, individual differences, and inability to collaborate.     

Some recent Unesco publications

Notes and Reviews

Some recent Unesco publications