Government of Canada

While organellar genomes are typically a single circular molecule, some have undergone extreme evolutionary changes, such as fragmentation. Among plastid genomes, extensive fragmentation is rare but has been observed in the green alga Boodlea composita (Cladophorales), wherein single-stranded chromosomes adopt an unusual hairpin structure, stabilized by inverted repeats. This plastome is also highly reduced in coding content, containing only 21 protein-coding genes that are highly divergent in sequence, yet the plastome comprises a numerous and heterogeneous chromosome population. The lack of plastomes among close relatives has stymied our understanding of the evolutionary origins of Boodlea's unique plastome characteristics. Here, we report plastomes from three additional Cladophorales families. We show that elevated mutation rates and a massive reduction in coding content preceded fragmentation and that fragmentation resulted in a highly heterogeneous population with hundreds of minicircular chromosomes and a concomitant increase in GC content. Long inverted repeats are absent in minicircular chromosomes, suggesting the repetitive sequences that facilitate the formation of hairpin structures are unique to the Boodlea clade. Codon reassignments also occurred concurrently among fragmented and non-fragmented Cladophorales plastomes. Our findings document a clear stepwise progression of plastid topologies and sequence characteristics in Cladophorales. This assists in our understanding of the evolution of fragmented organellar genomes in general, as well as the limits to coding capacity reduction and sequence divergence able to be withstood by a functioning plastid.

Introduction Giraffe populations across Africa face increasing pressures from habitat loss, poaching, and climate-driven resource scarcity, often intensifying interactions with nearby communities. In eastern Kenya, these pressures have contributed to emerging human–giraffe conflict (HGC), including crop losses, competition for water, and occasional livestock injuries. Although this reticulated giraffes play an important ecosystem role in the African savanna and the socio-economic well-being of African communities, their interactions with people, and how communities perceive and navigate HGC especially in non-tourism regions remains understudied. Methods To address this gap, we conducted 400 structured interviews with households around Bour-Algy Giraffe Sanctuary to assess local interactions with giraffes, attitudes, perceived risks, conflict drivers and preferred strategies for coexistence. Results On average, respondents generally possessed positive attitudes towards giraffes and, on average, respondents did not see giraffes as a risk: to personal or children’s safety, of disease transfer, to cattle productivity, or the integrity of the land. Risk perception even decreased if a respondent had encountered a giraffe. Interestingly, giraffes were perceived not to cause damage to land or other property by 59% of participants thus highlighting that it may be possible to promote co-existence in the region for a majority of people. Competition for water, lack of awareness on giraffe ecology, giraffe habitat encroachment, and poverty were raised as the four main cause of conflict. Respondents supported the use of fire, torches, and dogs as way to deter giraffes from farms. Discussion Our findings reveal a landscape where conflict exists but remains manageable, and where strong community support for giraffe presence provides a foundation for conflict transformation. Because of the proximity of giraffes to farms and homesteads, economic activities such as agriculture and cultural tourism, women-led acacia tree nurseries, invasive prosopis control and utilization along with opening up water corridors may motivate communities and minimize HGC. Our work provides a basis for action by the community and policy makers to promote giraffe-farmer co-existence in eastern Kenya.

The Reverse Water-Gas Shift (RWGS) reaction is a key process for converting carbon dioxide (CO2) into carbon monoxide (CO), enabling downstream synthesis of fuels and chemicals while contributing to CO2 emissions mitigation. This study investigates the performance of several Fe x -Ru y -based catalysts supported on different doped oxide materials (La-Al2O3, Ce-Al2O3, Sm-CeO2, Si-Al2O3), with the goal of identifying a cost-effective and thermally stable alternative to purely noble metal systems. Catalysts were evaluated in atmospheric conditions up to 800 °C and subjected to repeated temperature ramp cycles to assess CO2 conversion, CO selectivity, and long-term stability. Comprehensive characterization was performed using ICP-OES, BET, TPR, XRD, HRTEM, and XPS. The results reveal that optimizing the strength of the metal-support interaction, as well as the active metals ratio can have a significant impact, in terms of available active sites, which influences the catalytic performance, especially at lower temperatures (<500 °C). It was found that a ratio of 75% Fe and 25% Ru on Ce-doped Al2O3 provided this balance of properties. These findings provide insight into the design of robust, economically viable RWGS catalysts for efficient CO2 utilization.

Abstract From decolonisation and nation-building after independence to structural adjustments to the implementation of the United Nations’ Millennium Development Goals and, more recently, of the United Nations Sustainable Development Goals, social policy reform in sub-Saharan Africa has witnessed gradual changes but also more sudden and dramatic episodes caused by global crisis, including the recent worldwide pandemic. This Introduction to The State and the Imperative for Social Policy Reform in Africa explains how the volume explores social policy changes that have been made before and during the COVID-19 pandemic, and changes that need to be made towards protecting individuals, families, and communities against exposure to insecurity, poverty, and other vulnerabilities throughout the lifecycle. The Introduction is divided into three main sections. The first section offers a brief overview of social policy development in sub-Saharan Africa since the colonial era. The second section provides a short discussion of the COVID-19 pandemic and its aftermath on the African continent. Finally, the last section offers an overview of the chapters that comprise the volume.

Abstract Newly formed polyploids often face the challenge of genomic instability, which is usually observed as abnormal meiotic chromosome behaviour and poor fertility. However, the parental diploids of newly formed polyploids, as well as natural or evolved versions of the same polyploids, have usually adapted to these challenges and show regular meiosis and fertility. In this study, we assessed fertility and meiotic chromosome behaviour in established Brassica carinata , resynthesized B. carinata resulting from crosses between parental diploid species B. nigra and B. oleracea , and hybrids generated between these established and resynthesized B . carinata (resynthesized hybrids) using a combination of fertility estimates (seeds generated per pod, total seed set, and percentage pollen viability), and classical and molecular cytogenetic techniques. Cytological analysis revealed an expected chromosome number of 2 n = 34 in the established B . carinata lines, whereas the resynthesized lines had 1–2 missing chromosomes. Fluorescent in situ hybridisation revealed that the B . nigra -contributed subgenome of B. carinata was more prone to chromosome loss. Hybridisation between the established and resynthesized B . carinata lines resulted in an improvement in fertility and meiotic behaviour in comparison to the pure resynthesized lines. Also, meiotic chromosome behaviour and fertility in the resynthesized hybrids showed an improvement across generations, implying a combination of hybridisation with an established polyploid and cultivation over generations may hasten genomic stability in newly synthesized polyploid lineages.

This report describes a three-dimensional mobile-bed physical model study conducted to support the development of the Hillman Marsh and Barrier Beach Restoration Plan. The model was commissioned by SJL Engineering and was performed by the Ocean, Coastal, and River Engineering Research Centre of the National Research Council (NRC-OCRE). A three-dimensional physical model of the foreshore and shoreline at the project site was designed and constructed at a geometric scale of 1:40 in NRC’s Large Area Basin located in Ottawa, Canada. The beach sediment was modelled using fine sand that deformed naturally in response to wave forcing. The model was outfitted with a segmented wave machine to generate a range of realistic sea states and equipped with instrumentation to measure wave conditions, wave-induced nearshore currents, and changes in the shape of the beach. The model provided a reasonable simulation of the hydrodynamic and sedimentary processes at the site. Nearly 100 individual tests were conducted to assess the impact of the proposed coastal structures on the wave conditions and nearshore currents, as well as their effect on sediment transport processes and the response of the beach, for a range of prescribed wave conditions and water levels. These investigations generated a large quantity of valuable information that will be used by SJL Engineering to optimize and support the detailed design of the shoreline improvements and obtain the necessary permits required for construction.

Breast cancer is the most common cancer among women in Canada. Its presentation and outcomes vary significantly by race/ethnicity. This study explores breast cancer incidence, age at diagnosis, stage, subtype, and mortality, comparing Black and White women aged 20 years and older, using the 2011 and 2016 Canadian Census Health and Environment Cohorts databases. Black women were disaggregated into Caribbean, Central/West African (C/WA), Southern/East African (S/EA), and "Other" ancestry groups. The Black female study population had a lower mean age (43.0 years) than the White (50.5 years). Black women had lower overall age-standardized breast cancer incidence than White women. The age-specific incidence in Black women ages 30-39 of Caribbean origin was higher (RR 95% CL, 1.36, 1.04-1.79; 58.7 vs. 43.1 cases/100,000 person-years) than in White. White women had 14.6% of cases diagnosed at ages 20-49 compared to over 50% in Black women of C/WA and S/EA origins, with highest proportions of diagnoses occurring at least 10 years earlier among Black women (C/WA 46, S/EA 48, Caribbean 57, White 67). Proportions of prognostic stage I diagnoses were less common among Black vs. White women (53.2% vs. 65.9%, p < 0.0001), and triple negative breast cancer was more frequent among Black women (17.1% vs. 9.9%, p < 0.0001), particularly those of Central/West African ancestry (21.8%). Higher age-specific mortality was observed among Black women with Caribbean origins aged 40-49 (RR 95% CL, 1.70, 1.19-2.42) and 50-59 (RR 95% CL, 1.42, 1.08-1.88) compared to White women. Breast cancer characteristics and outcomes vary substantially by ancestry within Canada's Black population. Tailored screening strategies accounting for earlier onset and aggressive subtypes may help mitigate disparities.