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.     

Simulation framework for teaching in modeling and simulation areas

Simulation is the process of executing a model that describes a system with enough detail; this model has its entities, an internal state, some input and output variables and a list of processes bound to these variables. Teaching a simulation language such as general purpose simulation system (GPSS) is always a challenge, because of the way it executes the models and the abstraction level it can achieve, very different compared with most well-known programming languages. This article presents an open source simulation framework that implements a subset of entities of GPSS, which could help students to improve the understanding of this language. This tool also stores all entities of simulations in every single simulation time, which is very useful for debugging simulations, but also for getting a detailed history of all entities in the simulations, knowing exactly how they have behaved in every simulation time.     

The chimera of the competency-based approach to teaching mathematics: a study of carpentry purchases for home projects

Educational Studies in Mathematics - The competency-based approach conceives mathematics as a necessary tool for dealing with daily-life tasks. Many studies have focused on examining the low math...     

A cultural lens on Yucatec Maya families’ COVID-19 experiences

Health guidance during the COVID-19 pandemic led families around the world to spend more time isolated together, disrupting leisure activities, schooling, social interactions, and family work (UNICEF, 2021). Using the lens of Yucatec Maya families’ cultural values and practices, semi-structured interviews were conducted with 18 Yucatec Maya rural women in Mexico (M_age = 32; and for comparison, 13 middle-class European-American women (M_age = 41)), with children 6–7 years old, to analyze families’ experiences during the pandemic. Faced with the same isolation as in the United States, our exploratory analysis revealed Maya families experienced external stresses but at the same time were generally comfortable with their children's everyday activities and their social-emotional well-being, illuminating consequences of the communities’ cultural theories about development.     

Um Compasso Para Aprender: A Randomized Trial of a Social-Emotional Learning Program in Homicide-Affected Communities in Brazil

Despite global demand, the large-scale effects of social-emotional learning (SEL) programming in developing countries remain underexplored. Using a randomized control trial, this study examined the effectiveness of a school-wide SEL intervention—Programa Compasso (PC)—among 3,018 sociodemographically diverse, Portuguese-speaking children (M_age = 9.85 years) attending 90 public primary schools across Rio de Janeiro, Brazil in 2017. Average impacts of PC on children’s executive function, emotion knowledge, and behavior problems after one school year were null. Moderation analyses did, however, reveal evidence for positive impacts of PC on children’s labeling of emotional expressions and inhibitory control within low-homicide communities (d = 0.15 SDs), and null effects on these same outcomes in high-violence areas. Implementation and cultural considerations are discussed.     

Children’s first manifestations of cognitive control in the early years school: the importance of the educational situation and materiality

European Journal of Psychology of Education - Executive functions (EFs) embrace a range of cognitive control processes that allow us to control and direct our own behavior, thoughts, and emotions...     

Handwriting production in Spanish children with dyslexia: spelling or motor difficulties?

Reading and Writing - Spelling and handwriting are different processes; however, they are learned simultaneously, and numerous studies have shown that they interact. Besides the commonly reported...     

Between Scientific Ideas and Christian Religious Beliefs

Science & Education - Despite the importance of evolution to understand living phenomena, evolution teaching confronts several tensions, especially with respect to teachers’ and...