A global phylogeny of butterflies reveals their evolutionary history, ancestral hosts and biogeographic origins

Butterflies are a diverse and charismatic insect group that are thought to have evolved with plants and dispersed throughout the world in response to key geological events. However, these hypotheses have not been extensively tested because a comprehensive phylogenetic framework and datasets for butterfly larval hosts and global distributions are lacking. We sequenced 391 genes from nearly 2,300 butterfly species, sampled from 90 countries and 28 specimen collections, to reconstruct a new phylogenomic tree of butterflies representing 92% of all genera. Our phylogeny has strong support for nearly all nodes and demonstrates that at least 36 butterfly tribes require reclassification. Divergence time analyses imply an origin similar to 100 million years ago for butterflies and indicate that all but one family were present before the K/Pg extinction event. We aggregated larval host datasets and global distribution records and found that butterflies are likely to have first fed on Fabaceae and originated in what is now the Americas. Soon after the Cretaceous Thermal Maximum, butterflies crossed Beringia and diversified in the Palaeotropics. Our results also reveal that most butterfly species are specialists that feed on only one larval host plant family. However, generalist butterflies that consume two or more plant families usually feed on closely related plants

The role of attachment in Facebook usage: a study of Canadian college students

Considering the increasingly ubiquitous and frequent use of Facebook among college students, this study sought to explicate and unravel the salient determinants of Facebook use. Specifically, the main goal was to ascertain the factors influencing Collège d'enseignement général et professionnel (CEGEP) students’ Facebook use, for which a structural equation model was proposed to examine the relationships between constructs affecting this process. Using a recently proposed extended technology acceptance model, Dhammic Technology Acceptance Model (DTAM) for Facebook use, proposed by Teo and Jarupunphol [2015. Dhammic technology acceptance model (DTAM): Extending the TAM using a condition of attachment in Buddhism. Journal of Educational Computing Research, 52(1), 136–151. doi:10.1177/0735633114568859], we present results of the study using 233 completed survey data from a sample of CEGEP students in Montreal, Quebec. The DTAM was originally tested using a sample of Thai university students; this leads to a natural question as to whether this extended Technology Acceptance Model (TAM) model holds in a Western sample. The findings from the present study support the validity of the DTAM for explicating Facebook use, and add empirical evidence to the DTAM, according to which the condition of attachment exerts influence on Facebook use. The paper concludes with a discussion of the implications, limitations, and future extensions of the study

Exploring the drivers of technology acceptance: A study of Nepali school students

The question of what drives learners to adopt and use certain technologies over others, generally referred to as technology acceptance in the literature, is of interest to educational technology researchers, to policymakers, and developers in educational institutions. Technology acceptance models can inform adoption and implementation decisions. Despite the growing literature on technology acceptance, there is less evidence from countries with the lowest economic development indicators such as Nepal. The present study investigates the factors motivating technology use in the Nepali context. The study is grounded in an extended technology acceptance model (TAM) applied to using the internet for learning (not limited to online learning environments). The data were collected from 126 school students in Nepal (Mage = 15.19). We found empirical support for our proposed research model. There were strong relationships between computer self-efficacy and perceived enjoyment, and perceived enjoyment and behavioral intention. We found no influence of perceived usefulness or attitude on behavioral intention, contrary to theorized relationships and the empirical literature. Our findings show that the extended TAM translates to understudied populations such as Nepali secondary school students and suggests that it is sensitive to local situational differences that influence technology acceptance behaviors

Cultivating Computational Thinking Through Data Practice

After summarising the research context regarding defining, cultivating, and assessing computational thinking (CT), this theoretical paper examines data modelling using interactive displays, a CT practice that may be cultivated across several school subjects. Although working with data is not explicitly mentioned in some CT definitions, this work may activate different CT components, such as abstraction, decomposition, and pattern recognition. Furthermore, interactive displays, which are primarily a means for visualising data, can also be tools for modelling purposes if used within a modelling cycle. Focusing on this modelling in secondary education, we first consider main activities and their underlying skills, and outline what kind of support should be given to modellers, especially novices, in assisting them to complete this as easily as possible. We then consider what computational environment to use, which learning path to follow, and what assessment of learning to apply. Implications for teacher professional development are included

Negative confounding in the evaluation of toxicity: the case of methylmercury in fish and seafood.

International audienceIn observational studies, the presence of confounding [corrected] can distort the true association between an exposure and a toxic-effect outcome, if the confounding variable is not controlled for in the study design or analysis phase. While confounding is often assumed to occur in the same direction as the toxicant exposure, the relationship between the benefits and risks associated with fish and seafood consumption is a classic example of negative confounding: the exposure to methylmercury occurs with fish and seafood, which are also associated with beneficial nutrients, and the signs of mercury toxicity [corrected] Mercury and nutrients may affect the same epidemiological outcomes, but most studies addressing one of them have ignored the potential for negative confounding by the other. This article reviews the existing evidence of effects of both nutrient and contaminant intakes as predictors of neurodevelopmental and cardiovascular outcomes. Substantial underestimation of the effects of mercury toxicity and of fish benefits occurs from the lack of confounder adjustment and imprecision of the exposure parameters. Given this inherent bias in observational studies, regulatory agencies should reconsider current dietary advice in order to provide better guidance to consumers in making prudent choices to maintain a nutritious diet with seafood that is low in mercury concentrations. Attention should also be paid to the occurrence of negative confounding in other connections