In the nacre or aragonite layer of the mollusk shell there exist proteomes which regulate both the early stages of nucleation and nano-to-mesoscale assembly of nacre tablets from mineral nanoparticle precursors. Several approaches have been developed to understand protein-associated mechanisms of nacre formation, yet we still lack insight into how protein ensembles or proteomes manage nucleation and crystal growth. To provide additional insights we have created a proportionally-defined combinatorial model consisting of two nacre-associated proteins, C-RING AP7 (shell nacre, H. rufescens) and pseudo-EF hand PFMG1 (oyster pearl nacre, P. fucata) whose individual in vitro mineralization functionalities are well-documented and distinct from one another. Using SEM, flow cell STEM, AFM, Ca(II) potentiometric titrations and QCM-D quantitative analyses, we find that both nacre proteins are functionally active within the same mineralization environments, and at 1:1 mole ratios, synergistically create calcium carbonate mesoscale structures with ordered intracrystalline nanoporosities, extensively prolong nucleation times and introduce an additional nucleation event. Further, these two proteins jointly create nanoscale protein aggregates or phases that under mineralization conditions further assemble into protein-mineral PILP-like phases with enhanced ACC stabilization capabilities, and there is evidence for intermolecular interactions between AP7 and PFMG1 under these conditions. Thus, a combinatorial model system consisting of more than one defined biomineralization protein dramatically changes the outcome of the in vitro biomineralization process.

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Strategies for dissemination (purposive distribution of a guideline to specific audiences) and implementation (actions to support the general public in meeting guideline recommendations/behavioural benchmarks) of national movement guidelines (physical activity (PA), sedentary behaviour, and sleep) have yet to be synthesized. The purpose of this systematic scoping review was to identify strategies for dissemination and implementation of national PA, sedentary behaviour, and/or sleep guidelines among community-dwelling adults (aged >18 years) and/or stakeholders in Canada and analogous countries. Five search approaches (e.g., published literature, grey literature, targeted web-based, custom Google, and content expert consultation) identified records (e.g., empirical studies, organizational reports, website pages, or guideline messages) that discussed and/or evaluated dissemination or implementation strategies for a prespecified list of guidelines. A modified strategy classification system was developed to chart the data. Forty-seven reports met inclusion criteria. Dissemination strategies (n = 42) were more frequently reported than implementation strategies (n = 24). Implementation strategies were more frequently evaluated (n = 13 vs. 7 dissemination strategies) and associated with positive outcomes. The 13 studies that evaluated strategies were at high or serious risk of bias. We identified limited information about the dissemination and implementation of national movement guidelines and identified strategies were rarely evaluated. Greater efforts are required to increase the impact of guidelines among the general public and stakeholders and to build the evidence base in this field. (Open Science Framework registration: https://osf.io/4tyw3 .) Novelty An adapted movement guideline dissemination and implementation strategy classification framework is provided. Knowledge translation efforts should be documented and evaluated to advance science and practice in the movement guideline field.

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Background: Medical students are at risk of poor mental health and burnout compared to general population age- and education-matched peers, which has future implications for patient care. Research has suggested that demographic factors can predict mental illness and burnout among medical students. However, less is known about predictors of mental health and how they compare to predictors of burnout, and few studies have examined multiple demographics simultaneously. Objectives: This study examined and compared demographic predictors (gender, ethnicity, age, level of education, year of study and proposed specialty) of mental health and burnout in first to fourth year Canadian medical students. Method: Medical students ( n = 129) completed online surveys comprised of validated questionnaires. Results: Multiple regression indicated that third year (β = −.243, p = .013) negatively predicted mental health ( R2 = 15.0%). Female gender (β = .242, p = .005), ‘other’ ethnicities (β = .189, p = .028), third year (β = .391, p < .001) and fourth year (β = .212, p = .023) positively predicted burnout ( R2 = 32.7%). Female gender and fourth year predicted mental health and burnout differently. ‘Other’ ethnicity, second year and third year predicted mental health and burnout similarly. Conclusion: Findings fill gaps in the literature and may inform medical stakeholders in developing targeted programmes for improving medical students’ mental health and burnout. Medical students with greater well-being can progress into physicians who will be more likely to promote well-being in their patients.