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Concept: Suburb


Crohn’s disease and ulcerative colitis, collectively known as inflammatory bowel disease (IBD), are characterized by chronic inflammation of the gastrointestinal tract (1). IBD has been associated with poor quality of life and extensive morbidity and often results in complications requiring hospitalizations and surgical procedures (2-4). Most previous studies of IBD have used administrative claims data or data collected from limited geographic areas to demonstrate increases in estimated prevalence of IBD within the United States (5,6). Few national prevalence estimates of IBD among adults based on large, nationally representative data sources exist, and those that do tend to be based on older data. For example, the most recent national study used 1999 National Health Interview Survey (NHIS) data and estimated that 1.8 million (0.9%) U.S. adults had IBD (7). To examine the prevalence of IBD among the civilian, noninstitutionalized U.S. adult population, data from the 2015 NHIS were analyzed. Overall, an estimated 3.1 million, or 1.3%, of U.S. adults have received a diagnosis of IBD. Within population subgroups, a higher prevalence of IBD was identified among adults aged ≥45 years, Hispanics, non-Hispanic whites, and adults with less than a high school level of education, not currently employed, born in the United States, living in poverty, or living in suburban areas. The use of a nationally representative data source such as the NHIS to estimate the prevalence of IBD overall and by population subgroups is important to understand the burden of IBD on the U.S. health care system.

Concepts: Inflammation, United States, Ulcerative colitis, Crohn's disease, Colonoscopy, Gastroenterology, Inflammatory bowel disease, Suburb


Children with asthma in low-income urban areas have high morbidity. Phenotypic analysis in these children is lacking, but may identify characteristics to inform successful tailored management approaches.

Concepts: City, Urban area, Phenotype, Urban decay, Suburb


Recent studies have demonstrated the importance of accounting for human mobility networks when modeling epidemics in order to accurately predict spatial dynamics. However, little is known about the impact these movement networks have on the genetic structure of pathogen populations and whether these effects are scale-dependent. We investigated how human movement along the aviation and commuter networks contributed to intra-seasonal genetic structure of influenza A epidemics in the continental United States using spatially-referenced hemagglutinin nucleotide sequences collected from 2003-2013 for both the H3N2 and H1N1 subtypes. Comparative analysis of these transportation networks revealed that the commuter network is highly spatially-organized and more heavily traveled than the aviation network, which instead is characterized by high connectivity between all state pairs. We found that genetic distance between sequences often correlated with distance based on interstate commuter network connectivity for the H1N1 subtype, and that this correlation was not as prevalent when geographic distance or aviation network connectivity distance was assessed against genetic distance. However, these patterns were not as apparent for the H3N2 subtype at the scale of the continental United States. Finally, although sequences were spatially referenced at the level of the US state of collection, a community analysis based on county to county commuter connections revealed that commuting communities did not consistently align with state geographic boundaries, emphasizing the need for the greater availability of more specific sequence location data. Our results highlight the importance of utilizing host movement data in characterizing the underlying genetic structure of pathogen populations and demonstrate a need for a greater understanding of the differential effects of host movement networks on pathogen transmission at various spatial scales.

Concepts: United States, Influenza, Poverty in the United States, U.S. state, Pandemic, 2009 flu pandemic, Influenza A virus subtype H1N1, Suburb


The present study was focused on the effect of increasing urbanization including industrial and traffic activity on the accumulation of heavy metals and possible damage of selected physiological parameters (composition of assimilation pigments, membrane lipid peroxidation, and membrane integrity) of an epiphytic foliose lichen, Flavoparmelia caperata (L.) Hale. The lichen samples were collected from three different localities in and around Kolkata, India, two sites being from the urban area and one from the relatively non-polluted sub-urban area. The results showed that thalli from the urban sites have significantly higher concentrations of Fe, Cr, Cu, Zn, and Pb compared to those collected from the sub-urban site. Physiological parameters of damage also exhibited stress symptoms in thalli from the urban sites-decreased chlorophyll a indicating less photosynthetic efficiency, and increase in lipid peroxidation and electrolyte conductivity indicating cell membrane injuries. Correlation studies among metals pinpointed vehicular traffic as the main source of pollution in this area.

Concepts: City, Urban area, São Paulo, Urbanization, Suburb, Lichen, Village, Town


Steller’s jays (Cyanocitta stelleri) often store food and return to retrieve the stored items at a later time. Between caching and consumption, stored food has the potential to be pilfered by conspecific observers. We investigated whether individually marked Steller’s jays in suburban neighborhoods of Arcata, California, USA, adjusted cache concealment effort when in the presence of conspecifics. Both male and female jays traveled the shortest distances to cache when alone, traveled further when a mate was present, and traveled furthest when neighbors from adjacent territories were present. These results suggest that Steller’s jays recognize and respond to social contexts when concealing food items.

Concepts: Male, Suburb, Corvidae, Cache, Jay, Blue Jay, Steller's Jay, Cyanocitta


Neighborhood design affects lifestyle physical activity, and ultimately human wellbeing. There are, however, a limited number of studies that examine neighborhood design types. In this research, we examine four types of neighborhood designs: traditional development, suburban development, enclosed community, and cluster housing development, and assess their level of walkability and their effects on physical activity and wellbeing. We examine significant associations through a questionnaire (n = 486) distributed in Tucson, Arizona using the Walkability Model. Among the tested neighborhood design types, traditional development showed significant associations and the highest value for walkability, as well as for each of the two types of walking (recreation and transportation) representing physical activity. Suburban development showed significant associations and the highest mean values for mental health and wellbeing. Cluster housing showed significant associations and the highest mean value for social interactions with neighbors and for perceived safety from crime. Enclosed community did not obtain the highest means for any wellbeing benefit. The Walkability Model proved useful in identifying the walkability categories associated with physical activity and perceived crime. For example, the experience category was strongly and inversely associated with perceived crime. This study provides empirical evidence of the importance of including vegetation, particularly trees, throughout neighborhoods in order to increase physical activity and wellbeing. Likewise, the results suggest that regular maintenance is an important strategy to improve mental health and overall wellbeing in cities.

Concepts: Psychology, Sociology, Economics, Arithmetic mean, Mean, Suburb, Means, Neighbourhood


Which municipalities and locations within the United States contribute the most to household greenhouse gas emissions, and what is the effect of population density and suburbanization on emissions? Using national household surveys we developed econometric models of demand for energy, transportation, food, goods and services that were used to derive average household carbon footprints (HCF) for U.S. zip codes, cities, counties and metropolitan areas. We find consistently lower HCF in urban core cities (~40 tCO2e) and higher carbon footprints in outlying suburbs (~50 tCO2e), with a range of ~25 to >80 tCO2e in the 50 largest metropolitan areas. Population density exhibits a weak but positive correlation with HCF until a density threshold is met, after which range, mean and standard deviation of HCF decline. While population density contributes to relatively low HCF in the central cities of large metropolitan areas, the more extensive suburbanization in these regions contributes to an overall net increase in HCF compared to smaller metropolitan areas. Suburbs alone account for ~50% of total U.S. HCF. Differences in the size, composition and location of household carbon footprints suggest the need for tailoring of GHG mitigation efforts to different populations.

Concepts: Demography, Population, United States, City, Urban area, Population density, Suburb, Greenhouse gas


Many US cities have experienced population reductions, often blamed on crime and interpersonal injury. Yet the overall injury risk in urban areas compared with suburban and rural areas has not been fully described. We begin to investigate this evidence gap by looking specifically at injury-related mortality risk, determining the risk of all injury death across the rural-urban continuum.

Concepts: Population, City, Urban area, Rural area, Suburb, Village, Town, Megalopolis


Despite policy changes related to the use and distribution of marijuana in cities and states across the country, few studies have examined changes in disapproval and use of marijuana among American youth.

Concepts: United States, Poverty in the United States, U.S. state, Suburb, Humid subtropical climate, Country music, Old-time music


Cities can be characterized and modelled through different urban measures. Consistency within these observables is crucial in order to advance towards a science of cities. Bettencourt et al. have proposed that many of these urban measures can be predicted through universal scaling laws. We develop a framework to consistently define cities, using commuting to work and population density thresholds, and construct thousands of realizations of systems of cities with different boundaries for England and Wales. These serve as a laboratory for the scaling analysis of a large set of urban indicators. The analysis shows that population size alone does not provide us enough information to describe or predict the state of a city as previously proposed, indicating that the expected scaling laws are not corroborated. We found that most urban indicators scale linearly with city size, regardless of the definition of the urban boundaries. However, when nonlinear correlations are present, the exponent fluctuates considerably.

Concepts: Scientific method, Population ecology, City, Population density, Derivative, England, Urban planning, Suburb