arXiv subjects

Alexei Poliakov

Publications and source records attributed to Alexei Poliakov.

3 recordsLinked to original sources

arXiv2025

How liveable are London's 15-minute neighbourhoods? Exploring liveability profiles and active travel patterns in London

Healthy and liveable neighbourhoods have increasingly been recognised as essential components of sustainable urban development. Yet, ambiguity surrounding their definition and constituent elements presents challenges in understanding and evaluating neighbourhood profiles, highlighting the need for a more detailed and systematic assessment. This research develops a composite Liveability Index for Greater London based on metrics related to the proximity, density, and diversity of POIs, along with population density, and investigates how neighbourhood liveability relates to active travel behaviour. The Index is based on the principles of the 15-minute city paradigm (Moreno et al. 2021) and developed in line with OECD guidelines for composite indicators (European Union and Joint Research Centre 2008). The Index revealed distinct spatial patterns of neighbourhood liveability, with high liveability neighbourhoods predominantly clustered in Inner London. Decomposing the Index provided further insights into the strengths and weaknesses of each neighbourhood. Footfall modelling using ordinary least squares (OLS) and geographically weighted regression (GWR) indicates a generally positive relationship between liveability and footfall, with spatial variation in the strength of this association. This research offers a new perspective on conceptualising and measuring liveability, demonstrating its role as an urban attractor that fosters social interaction and active engagement.

physics.soc-ph↗

arXiv2025

Recurrent visitations reveal selectivity beyond the 15-Minute City vision

In the transition towards sustainable and equitable urban living, proximity-centred planning has been adopted in cities worldwide. Exemplified by the 15-Minute City (15mC), this planning paradigm often assumes that local amenity provision translates into local use, yet behavioural evidence on recurrent visitation remains limited. To address this gap, we introduce K-Visitation, a scalable, behaviourally informed framework for comparing recurrent visitation with proximity-based expectations, using 18 months of mobile phone data from 720,000 users in Finland. For each individual, K-Visitation compares recurrent destinations ($K_{freq}$) with nearest options ($K_{dist}$), and evaluates travel time differences between them and their neighbourhood proximity baseline. Across Finnish cities, individuals repeatedly bypassed nearby visited options that already exposed them to required daily amenity categories, incurring measurable travel time costs beyond what local opportunities could support. The sharpest divergence appears in amenity-rich urban cores: where the physical conditions for 15-minute living are strongest, recurrent destinations depart most from nearest options. A density-aware null model and destination-level classifier show that this divergence reflects selective behaviour: non-nearest recurrent destinations are not explained by amenity density alone and are often amenity-rich but functionally specialised. Amenity-specific analysis further reveals a hierarchy in which routine anchors adhere more closely to proximity, while specialised and infrastructural functions depend on wider catchments and connectivity. Our findings show that proximity is a necessary but insufficient condition for local living. The 15mC should therefore secure routine local access while using behavioural evidence to identify where proximity is bypassed and where wider connectivity remains necessary.

physics.soc-ph↗

arXiv2025

Eph-ephrin-mediated differential persistence as a mechanism for cell sorting

The phenomenon of cell sorting/segregation, by which cells organise spatially into clusters of specific cell type or function, is essential for tissue morphogenesis. This self-organization process involves an interplay between mechanical, biochemical, and cellular mechanisms that act across various spatial and temporal scales. Several mechanisms for cell sorting have been proposed; however, the physical nature of these mechanisms and how they lead to symmetric or asymmetric cell sorting remains unclear. Here, using experimental data from cocultures of genetically modified Human Embryonic Kidney (HEK293) cells and numerical simulations, we show the existence of a cell sorting mechanism based on transient increases in the persistence of motion of cells. This mechanism is activated on cells overexpressing the ephrinB1-related receptor EphB2 after their interaction with cells overexpressing ephrinB1. We show that this mechanism is sufficient to cause cell sorting, breaking the symmetry of the sorting dynamics, and show that the duration of this transient differential persistence state is optimal for enhancing sorting. Furthermore, we show that in combination with other interaction mechanisms, such as changes in direction-also known as contact inhibition of locomotion-and adhesion forces, differential persistence significantly reduces the timescale of sorting. Our findings offer insights into the behaviour of cell mixtures, the relevance of non-reciprocal interactions, and may provide insight into developmental processes and tissue patterning.

physics.bio-ph↗