No Association between Fish Intake and Depression in over 15,000 Older Adults from Seven Low and Middle Income Countries–The 10/66 Study

Background: Evidence on the association between fish consumption and depression is inconsistent and virtually nonexistent from low-and middle-income countries. Using a standard protocol, we aim to assess the association of fish consumption and late-life depression in seven low-and middle-income countries. Methodology/Findings: We used cross-sectional data from the 10/66 cohort study and applied two diagnostic criteria for late-life depression to assess the association between categories of weekly fish consumption and depression according to ICD-10 and the EURO-D depression symptoms scale scores, adjusting for relevant confounders. All-catchment area surveys were carried out in Cuba, Dominican Republic, Venezuela, Peru, Mexico, China, and India, and over 15,000 community-dwelling older adults (65+) were sampled. Using Poisson models the adjusted association between categories of fish consumption and ICD-10 depression was positive in India (p for trend = 0.001), inverse in Peru (p = 0.025), and not significant in all other countries. We found a linear inverse association between fish consumption categories and EURO-D scores only in Cuba (p for trend = 0.039) and China (p<0.001); associations were not significant in all other countries. Between-country heterogeneity was marked for both ICD-10 (I-2>61%) and EURO-D criteria (I-2>66%). Conclusions: The associations of fish consumption with depression in large samples of older adults varied markedly across countries and by depression diagnosis and were explained by socio-demographic and lifestyle variables. Experimental studies in these settings are needed to confirm our findings.Multidisciplinary SciencesSCI(E)SSCI0ARTICLE6null

An unexpected role for mixotrophs in the response of peatland carbon cycling to climate warming

Mixotrophic protists are increasingly recognized for their significant contribution to carbon (C) cycling. As phototrophs they contribute to photosynthetic C fixation, whilst as predators of decomposers, they indirectly influence organic matter decomposition. Despite these direct and indirect effects on the C cycle, little is known about the responses of peatland mixotrophs to climate change and the potential consequences for the peatland C cycle. With a combination of field and microcosm experiments, we show that mixotrophs in the Sphagnum bryosphere play an important role in modulating peatland C cycle responses to experimental warming. We found that five years of consecutive summer warming with peaks of +2 to +8°C led to a 50% reduction in the biomass of the dominant mixotrophs, the mixotrophic testate amoebae (MTA). The biomass of other microbial groups (including decomposers) did not change, suggesting MTA to be particularly sensitive to temperature. In a microcosm experiment under controlled conditions, we then manipulated the abundance of MTA, and showed that the reported 50% reduction of MTA biomass in the field was linked to a significant reduction of net C uptake (-13%) of the entire Sphagnum bryosphere. Our findings suggest that reduced abundance of MTA with climate warming could lead to reduced peatland C fixation

Identifying and Developing Students’ Ability to Reason with Concepts and Representations in Biology

External representations (ERs) and their constituent symbolism are of enormous pedagogical value to instructors, especially in the teaching of the submicroscopic world of biology, inherent in disciplines such as biochemistry, immunochemistry, molecular biology and physiology. Whereas symbolic conventions are rigorously applied in physics and chemistry to enhance learning, this is not always true in biology where inappropriate use of symbolic language often leads to confusing ER designs and a range of conceptual, visual, and reasoning difficulties. In this chapter, we present a synthesis of research conducted by our group within these important areas of biology education. We commence by describing a model of seven factors affecting students’ ability to interpret and learn from ERs. We then apply the model as a guiding theoretical framework in the classification of various cognitive skills or reasoning abilities, identified from a synthesis of literature. We also show how the model can inform the design of assessment tasks aimed at both assessing (summative) and guiding the development (formative) of students’ ER-related reasoning ability. We then describe various student difficulties identified by our group. In particular, we focus on visual, reasoning, and conceptual difficulties related to the decoding and interpretation of the diverse symbolic language used to visually represent protein structure, selected biochemical and physiological processes, and in the communication of modern molecular biology. We then show how the seven-factor model can be used as an analytical tool for identifying the nature and source of the difficulties and for designing potential remediation strategies for addressing the difficulties. We conclude by discussing the implications of our research on the use of the CRM model for biology education practitioners and researchers in improving the learning, teaching and assessment of biology related to ERs

Experts' Views on Translation Across Multiple External Representations in Acquiring Biological Knowledge About Ecology, Genetics, and Evolution

This new publication in the Models and Modeling in Science Education series synthesizes a wealth of international research on using multiple representations in biology education and aims for a coherent framework in using them to improve higher-order learning. Addressing a major gap in the literature, the volume proposes a theoretical model for advancing biology educators' notions of how multiple external representations (MERs) such as analogies, metaphors and visualizations can best be harnessed for improving teaching and learning in biology at all pedagogical levels. The content tackles the conceptual and linguistic difficulties of learning biology at each level-macro, micro, sub-micro, and symbolic, illustrating how MERs can be used in teaching across these levels and in various combinations, as well as in differing contexts and topic areas. The strategies outlined will help students' reasoning and problem-solving skills, enhance their ability to construct mental models and internal representations, and, ultimately, will assist in increasing public understanding of biology-related issues, a key goal in today's world of pressing concerns over societal problems about food, environment, energy, and health. The book concludes by highlighting important aspects of research in biological education in the post-genomic, information age

Interactive Visualization for Learning and Teaching Nanoscience and Nanotechnology

Nano education involves tackling the difficult task of conceptualizing imperceptibly small objects and processes. Interactive visualization serves as one potential solution for providing access to the nanoworld through active exploration of nanoscale concepts and principles. This chapter exposes and describes a selection of interactive visualizations in the literature, and reviews research findings related to their educational, perceptual and cognitive influence. In closing, we offer implications of interactive visualization for learning and teaching nano

Visualizing Protein Interactions and Dynamics: Evolving a Visual Language for Molecular Animation

Undergraduate biology education provides students with a number of learning challenges. Subject areas that are particularly difficult to understand include protein conformational change and stability, diffusion and random molecular motion, and molecular crowding. In this study, we examined the relative effectiveness of three-dimensional visualization techniques for learning about protein conformation and molecular motion in association with a ligand–receptor binding event. Increasingly complex versions of the same binding event were depicted in each of four animated treatments. Students (n = 131) were recruited from the undergraduate biology program at University of Toronto, Mississauga. Visualization media were developed in the Center for Molecular and Cellular Dynamics at Harvard Medical School. Stem cell factor ligand and cKit receptor tyrosine kinase were used as a classical example of a ligand-induced receptor dimerization and activation event. Each group completed a pretest, viewed one of four variants of the animation, and completed a posttest and, at 2 wk following the assessment, a delayed posttest. Overall, the most complex animation was the most effective at fostering students' understanding of the events depicted. These results suggest that, in select learning contexts, increasingly complex representations may be more desirable for conveying the dynamic nature of cell binding events