We conducted a large-scale survey of blue mussel (Mytilus spp.) populations and recruitment along 100 km of the Southern shore of the St. Lawrence Estuary, Québec, Canada. By taking advantage of the residual downstream current of our study system, we used cross-covariance analysis to test the hypothesis that postrecruitment and larval supply processes result in a positive relationship between local adult abundance and recruitment. We found no evidence of within-site correlation between adults and recruits. Alternatively, we hypothesized that demographic connectivity between populations would result in a positive covariance between adult abundance and recruitment at downstream sites separated by the average dispersal distance. We observed significant positive cross-covariance between sites separated by 12-18 km and 24-30 km. These results provide the first direct quantification of demographic connectivity between adult production and larval recruitment of Mytilus using simple survey data. The approach developed here measures connectivity over ecological time scales, and thus may be used to monitor temporal fluctuations in dispersal patterns.

The control of mussel population dynamics by larval supply and by more local processes affecting post-recruitment survival and growth has received considerable attention. However, immigration and emigration of adults and their contribution to colonization dynamics remain largely unknown. We manipulated the location and density of marked mussels in experimental transplants in the St. Lawrence Estuary (Québec). Our results reveal that colonization by Mytilus spp. is influenced by (1) passive adult movement through wave disturbance and immigration, (2) spatial aggregation and (3) topographic heterogeneity. Results show that ~90% of colonization in experimental plots was by individuals of 4 to 32 mm shell length and was associated with both withintransplant and local (< 0.15 m from transplant) aggregation. Experimental gaps revealed a similarly aggregated wave-disturbance process, propagating small (0.5 m) gaps across >100 m. The passive displacement distribution of marked and wave-dislodged individuals further revealed movement distance ranging from 1 to 150 m and disturbance mortality from < 20 to 40%. Together our results reveal that colonization in subarctic mussel populations can be largely controlled by cycles of adult displacement and further aggregation at the landscape level (~100 m). Such positive feedbacks involved in disturbance and colonization could explain strong fluctuations in abundance and challenge the interpretation of intertidal populations as systems mostly limited by larval supply and post-recruitment survival.

In conclusion, elongated and more medially deviated stylohyoid complexes are more frequent in males than in females. Their more frequent presence in the older age groups indirectly connects this phenomenon with the aging process.

The 20th century brought about major social challenges related to civil and human rights, triggering changes in urban environments and gradually adjusting the spatial and functional performances of cities to the needs of all users. In this article, the concept of Universal Urban Design (i.e., “Design for All”) is regarded as a sustainable placemaking process which enables the higher accessibility and usability of cities for all people, regardless of their age or (dis)abilities. The pilot project “Creating Accessible Pedestrian Corridors by the Limitless GIS Application” conduced in Serbia from 2017 to 2019 by the Faculty of Architecture at the University of Belgrade and the Non-Governmental Organization (NGO) Limitless proposes an innovative approach to urban design. Based on information and communication technology (ICT) adaptation, it is focused on the alternative concept-design of buildings, provision of ICT-based infrastructure, socioeconomic integration of all users, and ultimately on overall urban sustainability. The main outcome of the project was the development of a Geographic Information System (GIS) android application and an e-platform for adaptive placemaking. The project also provides a set of accessibility criteria based on Universal Urban Design, criteria that enable the mapping of locations based on the type of use, a set of recommendations for identified problems, as well as a brief analysis of the latest technological solutions for overcoming detected physical barriers. The Limitless GIS android application differs from the existing ones since it primarily identifies two target groups: (1) people with disabilities who could upload necessary data by established criteria; and (2) employees in the public sector (city authorities and municipalities) in charge of planning alternative routes and setting priorities and investment costs based on the identified problems. Pilot results of the project have revealed that in the current Serbian practice, there is still a lack of planned, consistent and continuous movement routes in urban areas. Terrain configuration represents a serious limitation for people with disabilities, while lifting platforms are recognized as a better solution than ramps (both for paraplegics and quadriplegics), due to their higher efficiency and minimized spatial requirements. Therefore, the android application and e-platform presented in this article contribute to the detection of actual problems at the local level as well as to the overall improvement of planning/design practice in Serbian cities.

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