Canadian Linguistic Association

Stream restoration constitutes a tool to mitigate hydro-morphological degradation, which affects a substantial proportion of European streams and rivers. However, improvement of local habitat quality does not always result in the recovery of macroinvertebrate assemblages, mostly due to persisting catchment-scale stressors or colonization constraints. In this study, we aimed to explore the effect of pollution pressure on selected biotic indices in restored sites, and the role of hydro-morphological quality of upstream reference sites on macroinvertebrate colonization. We utilized a paired comparison design and included 24 streams restored before up to 32 years. Using linear regression models, we tested the effect of factors such as water chemistry, land use, hydro-morphological parameters, distance between restored and reference sites, and time since restoration on diversity in restored streams. Alpha diversity parameters at both restored and reference sites displayed comparable biotic trends along all tested predictors, with water chemistry being the strongest predictor. This was also the case for beta diversity parameters, but here, interestingly, streams with higher pollution pressure exhibited higher dissimilarity between restored and reference sites. This dissimilarity was governed by turnover, indicating that restoration resulted in greater assemblage change in polluted streams. This suggests that restoration may, to an extent, increase diversity even in disturbed agricultural landscapes. However, we did not confirm the role of hydro-morphological quality of upstream reference site on macroinvertebrate colonization. Large-scale factors such as water chemistry and land use play a pivotal role in structuring macroinvertebrate assemblages.

This study employs structural equation modelling (SEM) to test the Cultural Autonomy Bilingual Education (CABE) model. CABE is implemented in official francophone language minority schools across Canada, excluding Quebec. Francophones represent a small minority (3.5% overall) in nine provinces and three territories. The SEM model assesses the impact of French and English enculturation in five domains (family, schooling, media, social networks, linguistic landscape) on various aspects of bilingual development: engaged identity, subjective linguistic vitality, oral competencies, and reading comprehension. Control variables included socioeconomic status, non-verbal intellectual aptitude, demographic vitality. SEM results demonstrate that CABE model hypotheses have a strong 'fit to the data.' As hypothesized, students in French high schools situated in low French vitality contexts achieve results in English reading comprehension equal to or exceeding those of their English-speaking peers in English high schools. These results were observed although they were taught all content courses in French, with English instruction limited to language arts courses. The findings support the fundamental principles of Cummins's linguistic interdependence theory. The study's conclusions advocate for recognizing CABE as a legitimate 'strong type of bilingual education' and challenge the traditional definition of bilingual education, highlighting the importance of employing both languages for content instruction.

In large bone defects the self-healing capacity is insufficient, and the current standard treatment, autologous bone grafting, has severe disadvantages such as limited availability and donor site morbidity. Alternatively, clinically available bone graft substitutes lack spatial control over scaffold architecture to anatomically match complicated bone defects. Therefore, the aim in this study was to develop a 3D printable composite biomaterialink to promote healing of large bone defects. The composite biomaterial-ink consisted of an organic biopolymer matrix with tyramine modified hyaluronic acid (THA) and collagen type I (Col) mixed with osteoinductive calcium phosphate particles (CaP). The biopolymer was combined with 0, 10, 20 and 30 % of either 45-63 mu m or 45-106 mu m CaP. mu CT imaging showed a homogeneous distribution of CaP in the THA-Col hydrogel and all composites were 3D printable. In vitro cell activity assays revealed no indirect cytotoxicity using L929 cells and high cell cytocompatibility using human mesenchymal stromal cells (hMSCs). Additionally, all composites supported in vitro osteogenic differentiation of hMSCs. This study highlights the development of a 3D printable composite biomaterial-ink using CaP and THA-Col hydrogel that holds significant potential to be used as patientspecific bone graft substitute for the regeneration of large bone defects. Statement of significance: This paper introduces a 3D printable composite biomaterial-ink made of osteoinductive calcium phosphate particles combined with matrix biopolymers collagen and hyaluronic acid, which was chemically modified to introduce shear thinning and shape fixation properties for 3D printing. The chemical modification only involves a small percentage of functional groups, preserving hyaluronan's biological properties. We demonstrated printability, the homogeneous distribution of the mineral phase, cytocompatibility and that the composites support osteogenesis of primary human mesenchymal stromal cells from multiple donors. The printability of the composite biomaterial-ink allows the creation of patient-specific implants with controlled geometry on porosity. This study contributes towards engineering personalized implants for replacing autologous bone grafting in all clinical situations where the bone self-healing capacity is insufficient.

The frequency and magnitude of extreme events, such as heat waves, are predicted to increase with climate change. However, assessments of the response of biological communities to heat waves are often inconclusive. We aimed to assess the responses in abundance, taxonomic and functional diversity indices of stream invertebrate communities to heat waves using long-term monitoring data collected across Europe. We quantified the heat waves' magnitude, analyzed the spatial (i.e., long-term mean) and temporal (anomaly around the long-term mean) components of variation in the magnitude of heat waves, and their interaction with anthropogenic stressors (ecological quality and land cover). For the spatial component of variation, we found a negative association of the community indices to the increasing magnitude of heat waves. Sites undergoing heat waves of higher magnitude showed fewer species and lower trait diversity compared with sites experiencing lower magnitude heat waves. However, we could not detect an immediate temporal response of the communities to heat waves (i.e., the temporal component). Furthermore, we found that the effects of heat waves interacted with the ecological quality of the streams and their surrounding land cover. Diversity declined with increasing heat waves' magnitude in streams with higher ecological quality or surrounded by forest, which may be due to a higher proportion of sensitive species in the community. Heat waves' impacts on diversity were also exacerbated by increasing urban cover. The interaction between heat waves' magnitude and anthropogenic stressors suggests that the effects of extreme events can compromise the recovery of communities. Further, the predicted increase in heat waves will likely have long-term effects on stream invertebrate communities that are currently undetected.

Staphylococcus aureus has multiple mechanisms to evade the host's immune system and antibiotic treatment. One such mechanism is the invasion of the osteocyte lacuno-canalicular network (OLCN), which may be particularly important in recurrence of infection after debridement and antibiotic therapy. The aim of this study was to develop an ex vivo model to facilitate further study of S. aureus invasion of the OLCN and early-stage testing of antibacterial strategies against bacteria in this niche. The diameter of the canaliculi of non-infected human, sheep, and mouse bones was measured microscopically on Schmorl's picrothionin stained sections, showing a large overlap in canalicular diameter. S. aureus successfully invaded the OLCN in all species in vitro as revealed by presence in osteocyte lacunae in Brown and Brenn-stained sections and by scanning electron microscopy. Murine bones were then selected for further experiments, and titanium pins with either a wild-type or ΔPBP4 mutant S. aureus USA300 were placed trans-cortically and incubated for 2 weeks in tryptic soy broth. Wild-type S. aureus readily invaded the osteocyte lacunae in mouse bones while the ΔPBP4 showed a significantly lower invasion of the OLCN (p = 0.0005). Bone specimens were then treated with gentamicin, sitafloxacin, R14 bacteriophages, or left untreated. Gentamicin (p = 0.0027) and sitafloxacin (p = 0.0280) significantly reduced the proportion of S. aureus-occupied lacunae, whilst bacteriophage treatment had no effect. This study shows that S. aureus is able to invade the OLCN in an ex vivo model. This ex vivo model can be used for future early-stage studies before proceeding to in vivo studies.