scholarly journals Parallel evolution of urban-rural clines

2021 ◽  
Author(s):  
Bradley J. Cosentino ◽  
James P. Gibbs
Keyword(s):  
Urban Areas ◽  
Forest Cover ◽  
Coat Color ◽  
Parallel Evolution ◽  
Sciurus Carolinensis ◽  
Science Data ◽  
Novel Traits ◽  
Urban Rural ◽  
Community Science ◽  
American Cities

AbstractUrbanization is the dominant trend of global land use change. The replicated nature of environmental change associated with urbanization should drive parallel evolution, yet insight into the repeatability of evolutionary processes in urban areas has been limited by a lack of multi-city studies. Here we leverage community science data on coat color in >60,000 eastern gray squirrels (Sciurus carolinensis) across 43 North American cities to test for parallel clines in melanism, a genetically based trait associated with thermoregulation and crypsis in gray squirrels. We show the prevalence of melanism in these mammals was positively associated with urbanization. Urban-rural clines in melanism were strongest in the largest cities with extensive forest cover and weakest or absent in cities with warm winter temperature, where thermal selection likely limits the prevalence of melanism. Our results demonstrate that novel traits can evolve in a highly repeatable manner among urban areas, modified by factors intrinsic to individual cities, including size, land cover, and climate.

scholarly journals High species turnover shapes anuran community composition in ponds along an urban-rural gradient

2020 ◽  
Author(s):  
Carolina Cunha Ganci ◽  
Diogo B. Provete ◽  
Thomas Püttker ◽  
David Lindenmayer ◽  
Mauricio Almeida-Gomes
Keyword(s):  
Species Richness ◽  
Community Composition ◽  
Urban Areas ◽  
Forest Cover ◽  
Species Turnover ◽  
Urban Environments ◽  
Rapid Expansion ◽  
Central Brazil ◽  
Negative Effect ◽  
Urban Rural

AbstractThe rapid expansion of urban areas in which natural and semi-natural areas are replaced by human infrastructure, such as buildings and streets, is a major threat to biodiversity worldwide. However, little is known about how the structure of biotic communities is affected by urbanization in the tropics. Here, we tested the effect of land use types in urban and peri-urban areas on frog species richness and community composition in central Brazil. We selected 20 ponds differing in size and surrounding levels of urbanization as well as natural forest cover. We then used a Poisson GLM and a distance-based Redundancy Analysis (db-RDA) to relate species richness and community composition, respectively, to environmental variables. Variation in species richness was best explained by pond size (positive effect) and amount of urbanization (negative effect) in the surrounding 500 m. Community composition was mainly driven by species turnover than by nestedness, with db-RDA showing that turnover was explained primarily by urban infrastructure and forest cover. Our results indicate that urbanization negatively influences species richness. Moreover, as the amount of urbanization increased, several species were replaced by others taxa that appear better adapted to urban environments. Our results indicate that maintaining large ponds with surrounding native vegetation in urban environments might be an effective strategy for conserving frog communities.

Urban–Rural Dichotomy in Planning: Review of Legal Framework in Four States of India

2021 ◽  
pp. 001955612110016
Author(s):  
Anurima Mukherjee Basu ◽  
Rutool Sharma
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Planning Process ◽  
Legal Framework ◽  
Quantum Jump ◽  
Class 1 ◽  
Urban Settlements ◽  
Urban Rural ◽  
Territorial Approach ◽  
Sizeable Number

Current urbanisation trends in India show a quantum jump in number of ‘census towns’, which are not statutorily declared as urban areas, but have acquired all characteristics of urban settlements. Sizeable number of such census towns are not located near any Class 1 city. Lack of proper and timely planning has led to unplanned growth of these settlements. This article is based on a review of planning legislations, institutional framework and planning process of four states in India. The present article analyses the scope and limitations of the planning process adopted in the rapidly urbanising rural areas of these states. The findings reveal that states are still following a conventional approach to planning that treats ‘urban’ and ‘rural’ as separate categories and highlights the need for adopting an integrated territorial approach to planning of settlements.

scholarly journals Urban–rural disparity in cancer incidence in China, 2008–2012: a cross-sectional analysis of data from 36 cancer registers

BMJ Open ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. e042762
Author(s):  
Shuai Yuan ◽  
Shao-Hua Xie
Keyword(s):  
Cancer Incidence ◽  
Rural Areas ◽  
Urban Areas ◽  
Incidence Rates ◽  
Cancer Type ◽  
Anatomic Site ◽  
Cross Sectional ◽  
Rural And Urban Areas ◽  
Rural And Urban ◽  
Urban Rural

ObjectiveThe substantial differences in socioeconomic and lifestyle exposures between urban and rural areas in China may lead to urban–rural disparity in cancer risk. This study aimed to assess the urban–rural disparity in cancer incidence in China.MethodsUsing data from 36 regional cancer registries in China in 2008–2012, we compared the age-standardised incidence rates of cancer by sex and anatomic site between rural and urban areas. We calculated the rate difference and rate ratio comparing rates in rural versus urban areas by sex and cancer type.ResultsThe incidence rate of all cancers in women was slightly lower in rural areas than in urban areas, but the total cancer rate in men was higher in rural areas than in urban areas. The incidence rates in women were higher in rural areas than in urban areas for cancers of the oesophagus, stomach, and liver and biliary passages, but lower for cancers of thyroid and breast. Men residing in rural areas had higher incidence rates for cancers of the oesophagus, stomach, and liver and biliary passages, but lower rates for prostate cancer, lip, oral cavity and pharynx cancer, and colorectal cancer.ConclusionsOur findings suggest substantial urban–rural disparity in cancer incidence in China, which varies across cancer types and the sexes. Cancer prevention strategies should be tailored for common cancers in rural and urban areas.

scholarly journals Mapping the premigration distribution of eastern Monarch butterflies using community science data

2021 ◽  
Author(s):  
Iman Momeni‐Dehaghi ◽  
Joseph R. Bennett ◽  
Greg W. Mitchell ◽  
Trina Rytwinski ◽  
Lenore Fahrig
Keyword(s):  
Science Data ◽  
Monarch Butterflies ◽  
Community Science

RURAL–URBAN MIGRATION AND CHILD SURVIVAL IN URBAN BANGLADESH: ARE THE URBAN MIGRANTS AND POOR DISADVANTAGED?

2008 ◽  
Vol 40 (1) ◽  
pp. 83-96 ◽  
Author(s):  
M. MAZHARUL ISLAM ◽  
KAZI MD ABUL KALAM AZAD
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Urban Poor ◽  
Child Survival ◽  
Childhood Mortality ◽  
Policy Implications ◽  
Urban Migration ◽  
Under Five ◽  
Urban Migrants ◽  
Urban Rural

SummaryThis paper analyses the levels and trends of childhood mortality in urban Bangladesh, and examines whether children’s survival chances are poorer among the urban migrants and urban poor. It also examines the determinants of child survival in urban Bangladesh. Data come from the 1999–2000 Bangladesh Demographic and Health Survey. The results indicate that, although the indices of infant and child mortality are consistently better in urban areas, the urban–rural differentials in childhood mortality have diminished in recent years. The study identifies two distinct child morality regimes in urban Bangladesh: one for urban natives and one for rural–urban migrants. Under-five mortality is higher among children born to urban migrants compared with children born to life-long urban natives (102 and 62 per 1000 live births, respectively). The migrant–native mortality differentials more-or-less correspond with the differences in socioeconomic status. Like childhood mortality rates, rural–urban migrants seem to be moderately disadvantaged by economic status compared with their urban native counterparts. Within the urban areas, the child survival status is even worse among the migrant poor than among the average urban poor, especially recent migrants. This poor–non-poor differential in childhood mortality is higher in urban areas than in rural areas. The study findings indicate that rapid growth of the urban population in recent years due to rural-to-urban migration, coupled with higher risk of mortality among migrant’s children, may be considered as one of the major explanations for slower decline in under-five mortality in urban Bangladesh, thus diminishing urban–rural differentials in childhood mortality in Bangladesh. The study demonstrates that housing conditions and access to safe drinking water and hygienic toilet facilities are the most critical determinants of child survival in urban areas, even after controlling for migration status. The findings of the study may have important policy implications for urban planning, highlighting the need to target migrant groups and the urban poor within urban areas in the provision of health care services.

scholarly journals Seasonal variation and spatial distribution of carbonaceous aerosols in Taiwan

2010 ◽  
Vol 10 (19) ◽  
pp. 9563-9578 ◽  
Author(s):  
C. C.-K. Chou ◽  
C. T. Lee ◽  
M. T. Cheng ◽  
C. S. Yuan ◽  
S. J. Chen ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Rural Areas ◽  
Urban Areas ◽  
Air Pollutants ◽  
Chemical Properties ◽  
Anthropogenic Sources ◽  
Carbonaceous Aerosols ◽  
Urban Rural ◽  
Southern Taiwan ◽  
Northern Taiwan

Abstract. To investigate the physico-chemical properties of aerosols in Taiwan, an observation network was initiated in 2003. In this work, the measurements of the mass concentration and carbonaceous composition of PM10 and PM2.5 are presented. Analysis on the data collected in the first 5-years, from 2003 to 2007, showed that there was a very strong contrast in the aerosol concentration and composition between the rural and the urban/suburban stations. The five-year means of EC at the respective stations ranged from 0.9±0.04 to 4.2±0.1 μgC m−3. In rural areas, EC accounted for 2–3% of PM10 and 3–5% of PM2.5 mass loadings, comparing to 4–6% of PM10 and 4–8% of PM2.5 in the urban areas. It was found that the spatial distribution of EC was consistent with CO and NOx across the network stations, suggesting that the levels of EC over Taiwan were dominated by local sources. The measured OC was split into POC and SOC counterparts following the EC tracer method. Five-year means of POC ranged from 1.8±0.1 to 9.7±0.2 μgC m−3 among the stations. It was estimated that the POM contributed 5–17% of PM10 and 7–18% of PM2.5 in Taiwan. On the other hand, the five-year means of SOC ranged from 1.5±0.1 to 3.8±.3 μgC m−3. The mass fractions of SOM were estimated to be 9–19% in PM10 and 14–22% in PM2.5. The results showed that the SOC did not exhibit significant urban-rural contrast as did the POC and EC. A significant cross-station correlation between SOC and total oxidant was observed, which means the spatial distribution of SOC in Taiwan was dominated by the oxidant mixing ratio. Besides, correlation was also found between SOC and particulate nitrate, implying that the precursors of SOA were mainly from local anthropogenic sources. In addition to the spatial distribution, the carbonaceous aerosols also exhibited distinct seasonality. In northern Taiwan, the concentrations of all the three carbonaceous components (EC, POC, and SOC) reached their respective minima in the fall season. POC and EC increased drastically in winter and peaked in spring, whereas the SOC was characterized by a bimodal pattern with the maximal concentration in winter and a second mode in summertime. In southern Taiwan, minimal levels of POC and EC occurred consistently in summer and the maxima were observed in winter, whereas the SOC peaked in summer and declined in wintertime. The discrepancies in the seasonality of carbonaceous aerosols between northern and southern Taiwan were most likely caused by the seasonal meteorological settings that dominated the dispersion of air pollutants. Moreover, it was inferred that the Asian pollution outbreaks could have shifted the seasonal maxima of air pollutants from winter to spring in the northern Taiwan, and that the increases in biogenic SOA precursors and the enhancement in SOA yield were responsible for the elevated SOC concentrations in summer.

scholarly journals Urban–Rural Disparities in the Magnitude and Determinants of Stunting among Children under Five in Tanzania: Based on Tanzania Demographic and Health Surveys 1991–2016

2021 ◽  
Vol 18 (10) ◽  
pp. 5184
Author(s):  
Wenjun Zhu ◽  
Si Zhu ◽  
Bruno F. Sunguya ◽  
Jiayan Huang
Keyword(s):  
Urban Areas ◽  
Health Surveys ◽  
Demographic And Health Surveys ◽  
Household Level ◽  
Individual Level ◽  
Child Stunting ◽  
Rural And Urban Areas ◽  
Rural And Urban ◽  
Urban Rural ◽  
The Individual

Our study aims to examine the disparity of under-5 child stunting prevalence between urban and rural areas of Tanzania in the past three decades, and to explore factors affecting the rural–urban disparity. Secondary analyses of Tanzania Demographic and Health Surveys (TDHS) data drawn from 1991–1992, 1996, 1999, 2004–2005, 2009–2010, and 2015–2016 surveys were conducted. Under-5 child stunting prevalence was calculated separately for rural and urban children and its decline trends were examined by chi-square tests. Descriptive analyses were used to present the individual-level, household-level, and societal-level characteristics of children, while multivariable logistic regression analyses were performed to examine determinants of stunting in rural and urban areas, respectively. Additive interaction effects were estimated between residence and other covariates. The results showed that total stunting prevalence was declining in Tanzania, but urban–rural disparity has widened since the decline was slower in the rural area. No interaction effect existed between residence and other determinants, and the urban–rural disparity was mainly caused by the discrepancy of the individual-level and household-level factors between rural and urban households. As various types of determinants exist, multisector nutritional intervention strategies are required to address the child stunting problem. Meanwhile, the intervention should focus on targeting vulnerable children, rather than implementing different policies in rural and urban areas.

Agriculture Biomaterial Industry in Romania

2021 ◽  
Vol 10 (1) ◽  
pp. 32-44
Author(s):  
Irina Bancescu
Keyword(s):  
Rural Development ◽  
Rural Areas ◽  
Urban Areas ◽  
Rural Poverty ◽  
Value Added ◽  
Poverty Rate ◽  
Economic Implications ◽  
Income Gap ◽  
Rural Income ◽  
Urban Rural

Rural areas in Romania are underdeveloped, with the main economic activity being agriculture. Urban-rural income gap and poverty levels are indicative of an underdeveloped rural area. Urban-rural absolute income gap for average monthly income increased from 352 RON in 2007 to 663 RON in 2017. Moreover, the work poverty rate is higher in rural areas than in urban areas. Economic rural development can be achieved by improvements of the labour market and introduction of new value-added products. Agricultural and non-agricultural activities are dependent on each other for a successful rural development leading to poverty alleviation. An industry that combines the two types of economic activities is agriculture biomaterial industry. In this paper, the authos investigates the factors influencing rural poverty and analyses the current stage of the bioplastics market in Romania and its economic implications. Bioplastics industry can reduce urban-rural income gaps and poverty in rural areas.

scholarly journals Relief influence on the spatial distribution of the Atlantic Forest cover on the Ibiúna Plateau, SP

2007 ◽  
Vol 67 (3) ◽  
pp. 403-411 ◽  
Author(s):  
WG. Silva ◽  
JP. Metzger ◽  
S. Simões ◽  
C Simonetti
Keyword(s):  
Atlantic Forest ◽  
Urban Areas ◽  
Large Scale ◽  
Forest Cover ◽  
Agricultural Land ◽  
Environmental Gradients ◽  
Aerial Photographs ◽  
General Distribution ◽  
Successional Stage ◽  
Slope Orientation

Several studies suggest that, on a large scale, relief conditions influence the Atlantic Forest cover. The aim of this work was to explore these relationships on a local scale, in Caucaia do Alto, on the Ibiúna Plateau. Within an area of about 78 km², the distribution of forest cover, divided into two successional stages, was associated with relief attribute data (slope, slope orientation and altitude). The mapping of the vegetation was based on the interpretation of stereoscopic pairs of aerial photographs, from April 2000, on a scale of 1:10,000, while the relief attributes were obtained by geoprocessing from digitalized topographic maps on a scale of 1:10,000. Statistical analyses, based on qui-square tests, revealed that there was a more extensive forest cover, irrespective of the successional stage, in steeper areas (>10 degrees) located at higher altitudes (>923 m), but no influence of the slope orientation. There was no sign of direct influence of relief on the forest cover through environmental gradients that might have contributed to the forest regeneration. Likewise, there was no evidence that these results could have been influenced by the distance from roads or urban areas or with respect to permanent preservation areas. Relief seems to influence the forest cover indirectly, since agricultural land use is preferably made in flatter and lower areas. These results suggest a general distribution pattern of the forest remnants, independent of the scale of study, on which relief indirectly has a strong influence, since it determines human occupation.

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