Mixed Neighborhoods Research Articles

Experimental evidence of inbreeding depression for competitive ability and its population-level consequences in a mixed-mating plant.

Inbreeding depression is a key factor regulating the evolution of self-fertilization in plants. Despite predictions that inbreeding depression should evolve with selfing rates as deleterious alleles are increasingly exposed and removed by selection, evidence of purging the genetic load in wild populations is equivocal at best. This discordance could be explained, in part, if the load underlying inbreeding depression is subject to soft selection, i.e., the fitness of selfed individuals depends on the frequency and density of selfed vs. outcrossed individuals in the population. Somewhat counterintuitively, this means that populations with contrasting mutation load can have similar fitness. Soft selection against selfed individuals may be expected when there is inbreeding depression for competitive ability in density-regulated populations. We tested population-level predictions of inbreeding depression in competitive ability by creating a density series of potted plants consisting of either purely outcrossed, purely selfed, or mixed (50% outcrossed, 50% selfed) seed of the mixed-matingbiennial Sabatia angularis (Gentianaceae) representing ecological neighborhoods. Focusing on the growth and survival of juveniles, we show that mean plant size is independent of neighborhood composition when resources are limiting, but greatest in outcrossed neighborhoods at low densities. Across a range of densities, this manifests as stronger density-dependence in outcrossed populations compared to selfed or mixed ones. We also found significantly greater size inequalities among individuals in mixed neighborhoods, even at high densities where mean juvenile size converged, a key signature of asymmetric competition between outcrossed and selfed individuals. Our work illustrates how soft selection could shelter the genetic load underlying inbreeding depression and its demographic consequences.

Mapping religion, space and economic outcomes in Indian cities

We deploy a socio-spatial approach and use a spatially representative survey that we conducted in the Indian cities of Hyderabad and Mumbai to analyse the relation between city space and religion. There are similarities and differences across these two cities in terms of how religion intersects with city space. While Muslims are much more marginalised in both cities relative to other communities like Hindus or Jains, and live in ghettos/enclaves, their position is relatively better in Mumbai. This is partly reflected in their higher integration with other religious communities in Mumbai and perhaps caused as well by this higher integration. A key finding on the relation between city space and religion is that compared to segregated neighbourhoods, mixed (‘greyer’) neighbourhoods produce better outcomes such as lower poverty and better education. This finding has significance for cities across the world as a way of assessing segregation and its harmful effects on economic development outcomes. We also argue that while Indian cities have become less integrated along religious lines over the last three to four decades, this process is both universal (i.e. relevant beyond the Indian context) and far from complete, and needs to be reversed.

The Agency of Socially Mixed Neighbourhoods Insights from the Historic Centre of Naples

In a city like Naples, the concept of neighbourhood is continuously negotiated and redefined through everyday practices of urban interaction and through the existence of multiple forms of social capital that animate daily life. In the historic centre of the city the negotiation of the neighbourhoods is influenced by the coexistence and close proximity of different social groups, which compels us to think about the significance of the 'agency of place' and how social difference defines the neighbourhood itself. The diverse housing situations and economic activities shape the characteristics of these central neighbourhoods that, crucially, are not captured in formal, administrative definitions of the city's districts. Through the case of the Condominio Sociale divia S. Nicola a Nilo, a city council housing policy to build a socially inclusive block of flats, this article discusses how the coexistence of various inhabitants, social networks, and spatial relationships represent a fundamental feature of the concept of neighbourhood in Naples. In doing so, the article points to the importance of the 'agency of place' and the maintenance of social heterogeneity as key to inclusive urban policies.

Equity-oriented power sharing and demand response for enhancing green energy access in mixed communities

The distribution of renewable energy resources (RERs) is currently uneven and is largely influenced by their affordability across various communities. This has led to disparities in access to green energy for different community members. To address these inequalities, this study proposes an equity-oriented power-sharing mechanism that incorporates demand response (DR). The implementation of this approach will increase the availability of green energy for all members of the community in mixed neighborhoods. First, a DR program is introduced for conventional homes (i.e., homes without RERs) to maximize the consumption of RERs by shifting their load to RER excess intervals. Then, a proportionally fair mechanism is introduced to distribute the available resources among community members during times of high excess. The objective is to minimize the grid dependence of community members by reducing their reliance on purchasing power from the grid. To ensure renewable energy homes (i.e., homes with installed RERs) maintain their green energy access, additional constraints are put in place to prioritize their energy needs when compared to the non-sharing case. Three indices (green energy access, grid dependence, and cost reduction) are introduced to evaluate the performance of the proposed method in different cases: the base case, the power-sharing-only case, and the case of power-sharing with the DR. Finally, the impact of different seasons, day types, and user-defined parameters is analyzed. Simulations have shown that the proposed method can significantly increase the green energy access of conventional homes without affecting the access to green energy of renewable energy homes. It also decreases the grid dependence and the electricity cost of the entire community.

Contrasting inclusionary housing initiatives in Denmark, Sweden, and Norway: how the past shapes the present

Inclusionary housing policies, aiming at creating both affordable housing and mixed neighbourhoods through land use regulation, do not have a long history in Scandinavia. Although Denmark, Norway, and Sweden have traditional welfare state perspectives on equal opportunities and housing, the use of the planning system to implement policy is hesitant. This article outlines the diverse political backgrounds and influences from housing and planning systems that explain this paradox. Further, differences between the housing and planning systems in the three countries are well illustrated by the varying interpretations of inclusionary housing policies. Policy results, in terms of affordability and social mix, play out very differently in the given contexts. The article in this sense adds to the scholarly conversations about barriers and opportunities for IH policy implementation, by contextualizing the conversation with implications from within systems that are relatively homogeneous and aiming for redistribution and equity. This raises questions about when, if, and how IH policy is the appropriate approach.

Characterization of Fractional Mixed Domination Number of Paths and Cycles

Let G′ be a simple, connected, and undirected (UD) graph with the vertex set M(G′) and an edge set N(G′). In this article, we define a function f:M∪N⟶0,1 as a fractional mixed dominating function (FMXDF) if it satisfies fRmx=∑yϵRmxfy≥1 for all x∈MG′∪NG′, where Rmx indicates the closed mixed neighbourhood of x, that is the set of all y∈MG′∪NG′ such that y is adjacent to x and y is incident with x and also x itself. Here, pf=∑x∈M∪Nfx is the poundage (or weight) of f. The fractional mixed domination number (FMXDN) is denoted by γfm∗G′ and is designated as the lowest poundage among all FMXDFs of G′. We compute the FMXDN of some common graphs such as paths, cycles, and star graphs, the middle graph of paths and cycles, and shadow graphs. Furthermore, we compute upper bounds for the sum of the two fractional dominating parameters, resulting in the inequality γf1′Τ+γfm∗Τ≤r+p−radΤ−α, where γf1′ and γfm∗ are the fractional edge domination number and FMXDN, respectively. Finally, we compare γfm∗ to other resolvability-related parameters such as metric and fault-tolerant metric dimensions on some families of graphs.

MNCLCDA: predicting circRNA-drug sensitivity associations by using mixed neighbourhood information and contrastive learning

BackgroundcircRNAs play an important role in drug resistance and cancer development. Recently, many studies have shown that the expressions of circRNAs in human cells can affect the sensitivity of cells to therapeutic drugs, thus significantly influencing the therapeutic effects of these drugs. Traditional biomedical experiments required to verify this sensitivity relationship are not only time-consuming but also expensive. Hence, the development of an efficient computational approach that can accurately predict the novel associations between drug sensitivities and circRNAs is a crucial and pressing need.MethodsIn this research, we present a novel computational framework called MNCLCDA, which aims to predict the potential associations between drug sensitivities and circRNAs to assist with medical research. First, MNCLCDA quantifies the similarity between the given drug and circRNA using drug structure information, circRNA gene sequence information, and GIP kernel information. Due to the existence of noise in similarity information, we employ a preprocessing approach based on random walk with restart for similarity networks to efficiently capture the useful features of circRNAs and drugs. Second, we use a mixed neighbourhood graph convolutional network to obtain the neighbourhood information of nodes. Then, a graph-based contrastive learning method is used to enhance the robustness of the model, and finally, a double Laplace-regularized least-squares method is used to predict potential circRNA-drug associations through the kernel matrices in the circRNA and drug spaces.ResultsNumerous experimental results show that MNCLCDA outperforms six other advanced methods. In addition, the excellent performance of our proposed model in case studies illustrates that MNCLCDA also has the ability to predict the associations between drug sensitivity and circRNA in practical situations.ConclusionsAfter a large number of experiments, it is illustrated that MNCLCDA is an efficient tool for predicting the potential associations between drug sensitivities and circRNAs, thereby can provide some guidance for clinical trials.

Antagonistic Integration in the Private Sector-Driven Housing Developments in South Africa

Cities in apartheid South Africa did not exhibit inclusivity traits and city developments thereafter have not differed significantly. Neoliberal urbanism asserts that the city is envisaged as a playing field for the elites, and growing socio-economic inequalities are managed by creating privatised, customised, and networked spaces for consumption by the urban elites. This ideology seeks to enlarge the role of market forces in the housing sector, to increase the role of elites in shaping urban landscapes. This paper, anchored on the theory of neoliberal urbanism, showcases the difficulties of integration and inclusivity in a socio-economically mixed neighbourhoods in post-apartheid SA, using Shaka’s Head in the Ballito area of the KwaDukuza Municipality as the case study. The study engages literature on the production of space to demonstrate how the economically dominant urban classes have maintained hegemony over urban governance and suppressed the efforts of local governments to shape urban neighbourhoods and the interests of the previously disadvantaged groups. Data were obtained through in-depth interviews with role-players in physical planning and human settlements developments and supplemented with household interviews with residents of Shaka’s Head. Research results showed that the type of integration observed in the area can best be described as ‘antagonistic integration’. The paper recommends an increased role of the government in land ownership, physical development, and regulation of private developments. Keywords: Housing, Private developments, Urban communities, Integration, Antagonism

Neighbourhoods in shaping migrant integration: A study of peri-urban Beijing

The question of how (im)migrants integrate into their host societies has long been a focus of scholarly research. This article adds to this body of knowledge by examining how different types of neighbourhoods shape the integration experience of migrant residents and their daily practice in peri-urban Beijing. The study was conducted by non-participant observation and semi-structured interviews in four peri-urban Beijing neighbourhoods. The findings suggest that migrant integration has a spatial dimension, with integration differences being enhanced and fixed through residential differentiation. Specifically, a migrant’s position in the urban economy predetermines their integration path and neighbourhood preference, with the neighbourhood further impacting their social integration through embedded lifestyles and ideologies. Neighbourhoods serve as essential places of shared experience in which distinct migrant social groups are formed. Theoretically, the study contributes to the debate between ethnic enclaves and mixed neighbourhoods by arguing that mixed neighbourhoods foster stronger sentiments toward host cities among migrant residents. The failure of integration is not necessarily a result of a neighbourhood’s homogenous tenure and population but rather because residents are not involved in the formal urban economy. Unlike ethnoburbs in America, urban villages in peri-urban Beijing cannot generate upward social mobility because of the informality. Low-skilled migrant entrepreneurs struggle to develop their informal businesses facing unpredictable demolishment of urban villages.

Social mix and subjective wellbeing in Chinese urban neighborhoods: Exploring the domino effects of social capital through multilevel serial mediation analysis

As a policy response to residential segregation, social mix has been actively introduced in homogeneous neighborhoods. Focusing on neighborhood social mix in urban China, this research attempts to unravel the domino effects of social capital in mediating the relationships between social mix and residents’ wellbeing. Drawing on a dataset with a hierarchical structure and capturing the mediating effects of social capital with various operationalized forms, we conduct multilevel serial mediation analysis. Our research findings verify the sequential mechanism of social capital and reveal that the trigger point of domino effects lies in the occurrence of public familiarity. Following this, most of the subsequent forms of social capital can be generated spontaneously one after another, resembling domino effects. Nonetheless, owing to socioeconomic disparity, such domino effects halt at forms of matters sharing and social leverage, which are particularly conducive to life chances. By situating the progressive formation process of social capital into the broader neighborhood social mix framework, this study helps to unpack the black box of social mix mechanisms in promoting subjective wellbeing. Practically, the empirical findings and policy implications suggest that the design of both social mix indicators and physical space are important for optimizing the development and outcomes of socially mixed neighborhoods.

The Spatial Configuration of Segregation, Elite Fears of Disease, and Housing Reform in Washington, D.C.’s Inhabited Alleys

AbstractIn the early 1900s, Washington, D.C. contained many alleys in the interior of blocks inhabited by impoverished Black residents. Elite reformers engaged in an aggressive campaign to eliminate alleys, on the grounds of their purported unsanitary environment and high disease prevalence. In this paper, I combine quantitative, qualitative, and spatial sources to explore new perspectives on segregation, public health, and the racialized efforts of housing reformers during this period. I find that reformers overstated the horrors of conditions in alleys and their effects on residents’ health: poorer health among alley residents was in large part due to Black residents’ marginalization wherever they might live. Alleys’ status as racialized space, coupled with progressive paternalistic racism, facilitated the discursive construction of alleys as pathological “breeding grounds of disease.” Further, my findings shed new light on micro-configurations of segregation within racially mixed neighborhoods, as well as the social experience and meaning of such configurations. Far from indicating harmonious coexistence, the proximity of such alleys to white homes and institutions spurred elite Washingtonians’ self-interested fear of disease spreading beyond the alleys. Thus, this pattern of segregation helps explain the zeal of the campaign to eradicate alleys: as a means of achieving separation from undesired Black neighbors whom white reformers associated with contagion.

Species diversity and competition have minor effects on the growth response of silver fir, European larch and Douglas fir to drought

With climate change, the frequency and duration of droughts are increasing, strongly impacting forest ecosystems. Therefore, a thorough understanding of the factors influencing tree response to drought is needed. Particularly, it remains unclear how competition and species diversity influence the drought sensitivity of tree species. Thinning (i.e., lowering competition) and mixing species (i.e., increasing diversity) are two common forest management practices that are thought to help forests to cope with droughts. However, their actual effects are still controversial. We sampled and measured tree-ring widths of 401 conifer trees with a wide range of competition and species diversity in their neighborhood across a bioclimatic gradient in Switzerland. Based on mixed-effects models and correlations, we examined the climate sensitivity of silver fir, European larch and Douglas fir and analyzed how competition and species diversity affect their radial growth and drought sensitivity. Silver fir was the least sensitive species to temperature, precipitation, and climatic water balance. When we analyzed the combined effects of the climatic water balance, competition and species diversity on tree radial growth over the past 20 years, we found that competition usually had a negative effect on radial growth of the three species, while species diversity had no effect. However, when focusing on drought resilience, competition had a negative effect for silver fir only, and a more mixed neighborhood enhanced the drought resilience of Douglas fir. Larch showed a higher drought sensitivity than silver fir and Douglas fir. At most sites, radial growth of all species recovered within two years after the severe droughts of 2003 and 2018. Overall, our results suggest that competition and species diversity have minor effects on the drought resilience of silver fir, larch and Douglas fir in Switzerland.

Urban segregation on a micro scale: the consequences for the low-income residents of a socioeconomically mixed neighborhood in Mexico city

ABSTRACT The patterns of socio-spatial organization of differences have changed in Latin American cities, which has transformed the scale of urban segregation. This has led to an increase in socially mixed areas and poverty enclaves in neighborhoods that have attracted the interest of, both, public and private sectors. Although this phenomenon has been widely studied, the consequences for low-income inhabitants living in spaces that are undergoing urban renewal are not clear. This paper seeks to contribute to the understanding of the implications of these changes by exploring three features: access to social programs; changes in the use and appropriation of public space; and daily practices and the limits of urban sociability. The research method consisted of a qualitative analysis of secondary sources, fieldwork, and interviews. We conclude that the decrease of urban segregation scale affects not just the housing structure, but also access to social programs, public spaces, and urban sociability; these factors are a part of the material and symbolic rearrangements that allow groups with great socioeconomic differences to live close to one another.

Book review: Divercities: Understanding super-diversity in deprived and mixed neighbourhoods

Book review: Divercities: Understanding super-diversity in deprived and mixed neighbourhoods

Aging effects in Schelling segregation model

The Schelling model has become a paradigm in social sciences to explain the emergence of residential spatial segregation, even in the presence of high tolerance to mixed neighborhoods by the side of citizens. In particular, we consider a noisy constrained version of the Schelling model, in which agents maximize its satisfaction, related to the composition of the local neighborhood, by infinite-range movements towards satisfying vacancies. We add to it an aging effect by making the probability of agents to move inversely proportional to the time they have been satisfied in their present location. This mechanism simulates the development of an emotional attachment to a location where an agent has been satisfied for a while. The introduction of aging has several major impacts on the model statics and dynamics: the phase transition between a segregated and a mixed phase of the original model disappears, and we observe segregated states with a high level of agent satisfaction even for high values of tolerance. In addition, the new segregated phase is dynamically characterized by a slow power-law coarsening process similar to a glassy-like dynamics.

The influence of the ‘Fragmented City’ on wellbeing: Do mixed neighbourhoods affect young adults' life trajectories in Bogota?

This article investigates the effects that living in heterogeneous neighbourhoods may have on well-being, in order to shed light on the potential consequences of promoting residential mix policies. Using propensity score matching models, the study investigates whether 120 disadvantaged young adults located in a heterogeneous neighbourhood in Bogota scored differently on a battery of indicators of well-being compared to disadvantaged young adults located in a homogenous neighbourhood. Results suggest that when young adults live close to better-off peers, those in heterogeneous neighbourhoods are more likely to experience reduced capability scores than those in homogeneous neighbourhoods.

Topological influence and locality in swap schelling games

Residential segregation is a wide-spread phenomenon that can be observed in almost every major city. In these urban areas residents with different racial or socioeconomic background tend to form homogeneous clusters. Schelling’s famous agent-based model for residential segregation explains how such clusters can form even if all agents are tolerant, i.e., if they agree to live in mixed neighborhoods. For segregation to occur, all it needs is a slight bias towards agents preferring similar neighbors. Very recently, Schelling’s model has been investigated from a game-theoretic point of view with selfish agents that strategically select their residential location. In these games, agents can improve on their current location by performing a location swap with another agent who is willing to swap. We significantly deepen these investigations by studying the influence of the underlying topology modeling the residential area on the existence of equilibria, the Price of Anarchy and on the dynamic properties of the resulting strategic multi-agent system. Moreover, as a new conceptual contribution, we also consider the influence of locality, i.e., if the location swaps are restricted to swaps of neighboring agents. We give improved almost tight bounds on the Price of Anarchy for arbitrary underlying graphs and we present (almost) tight bounds for regular graphs, paths and cycles. Moreover, we give almost tight bounds for grids, which are commonly used in empirical studies. For grids we also show that locality has a severe impact on the game dynamics.

An investigation of the longitudinal relationship between neighbourhood income inequality and individual self-rated health in England.

There are mixed findings on whether neighbourhood income inequality leads to better self-rated health (SRH) or not. This study considers two hypotheses: individuals living in more unequal neighbourhoods have better SRH and the level of neighbourhood income inequality and its impact on SRH is moderated by household and neighbourhood level income related variables. Data from Waves 8-10 of the UK Household Longitudinal Study for respondents living in England at wave 8 were used. Neighbourhood income inequality was measured using Gini coefficients of household income from the Pay As You Earn and benefits systems for Lower Super Output Areas. Longitudinal ordinal multilevel models predicted self-rated health in 2016-18, 2017-19 and 2019-20 by income inequality and its interaction with household income, neighbourhood median income and neighbourhood deprivation, conditional on individual educational attainment, age, sex, ethnic group, years lived in current residence, region of residence and study wave. There were 24,889 respondents analysed over three waves. SRH was worse for those living in more income equal neighbourhoods. There was no indication that neighbourhood inequality was moderated by household income, neighbourhood median income or neighbourhood deprivation. These findings are in line with the balance of existing evidence and support policy interventions that aim to create mixed communities for the purpose of improving population health.

Introducing simple models of social systems

Learning to model social systems can foster critical thinking about the applications of mathematical methods to social issues and also lead to professional opportunities. I introduce an intriguing simple model proposed by Thomas Schelling to understand urban segregation. It shows that even when individual agents seek mixed neighborhoods, they can collectively create a segregated city that makes everyone unhappy. The model can be presented as a simple role-playing game or by a computer program. At a more advanced level, the methods of statistical physics provide a way to calculate equilibrium states corresponding to segregated configurations. I also discuss why physics inspired models have difficulties in understanding the complex dynamics of real social systems.

Multi-manned assembly line balancing with sequence-dependent set-up times using an enhanced migrating birds optimization algorithm

In multi-manned assembly lines, more than one operator is allowed on the same workstation. Limited research has been carried out on sequence-dependent set-up times. Therefore, this article optimizes the multi-manned assembly line balancing problem with sequence-dependent set-up times using an enhanced migrating birds optimization (EMBO) algorithm. Sequence-dependent set-up times are embedded in two ways: forward and backward set-ups. EMBO designs a mixed neighbourhood search and acceptance criteria to help it escape from local optima, and a diversification mechanism to enhance the global exploration ability. Three types of experiment and two scenarios, with low and high set-up times, are conducted to test the performance of the mixed-integer linear programming (MILP) model and EMBO. The first experiment compares three MILP models (no, low and high set-up times) to illustrate the significance of set-up times. The final two experiments demonstrate the effectiveness of EMBO by comparison with the MILP model and six state-of-the-art methods.