نتایج جستجو برای: and population density

تعداد نتایج: 16946265  

2015
Yaoqi Zhang Amartuvshin Amarjargal

Land tenure is to define who hold the land as well as the relationship between tenant and the lord. Most fundamentally tenure and changing tenure is capturing the value of the resource. The nature of the resource and changing relative scarcity are essential to induce or lead evolution of land tenure. Pasture resources have been held in open access and communal tenure for much of the long histor...

2016
Michał Bogdziewicz Rafał Zwolak Lauren Redosh Leszek Rychlik Elizabeth E. Crone

Home range size generally decreases with increasing population density, but testing how this relationship is influenced by other factors (e.g., food availability, kin structure) is a difficult task. We used spatially explicit capture-recapture models to examine how home range size varies with population density in the yellow-necked mouse (Apodemus flavicollis). The relationship between populati...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1974
T Nagylaki

The geographical structure of a population distributed continuously and homogeneously along an infinite linear habitat is explored. The analysis is restricted to a single locus in the absence of selection, and every mutant is assumed to be new to the population. An explicit formula is derived for the probability that two homologous genes separated by a given distance at any time t are the same ...

2016
Luca Candeloro Lara Savini Annamaria Conte

In recent years researchers have investigated a growing number of weighted heterogeneous networks, where connections are not merely binary entities, but are proportional to the intensity or capacity of the connections among the various elements. Different degree centrality measures have been proposed for this kind of networks. In this work we propose weighted degree and strength centrality meas...

Journal: :Emerging Infectious Diseases 2008
Silke Ruhl Genevieve Goy Nicola Casson Rudolf Thoma Andreas Pospischil Gilbert Greub Nicole Borel

(i.e., East Anacapa and Santa Barbara Islands) or high prevalence (i.e., San Miguel and Santa Rosa Islands). Future studies comparing longterm dynamics on islands and related mainlands are needed to examine the possibility that insular systems provide unique opportunities to understand the factors affecting pathogen dynamics and human risk. Given the substantial variation in mouse population de...

2007
Mario Luis Small

Objectives. This study examines which of five neighborhood conditions help account for racial differences in social networks. Methods. The data set is the Urban Poverty and Family Life Survey, a survey of blacks, whites, Mexicans, and Puerto Ricans clustered in Chicago Census tracts, matched to 1990 Census data. I estimate HGLM models predicting five indicators of social isolation and five indi...

Journal: :The Journal of infectious diseases 1997
J Zhang J J Yu R W Linkins R Z Zhang K A Wang S L Cochi

The World Health Organization recommends conducting supplemental immunization activities to eradicate poliomyelitis by the year 2000. Although effective in eliminating poliomyelitis from the Americas, supplemental campaigns require substantial resources. To assess differential campaign effectiveness in eliminating this disease, poliomyelitis occurrence was compared in counties in China that tar...

Journal: :Royal Society open science 2016
Elsa Arcaute Carlos Molinero Erez Hatna Roberto Murcio Camilo Vargas-Ruiz A Paolo Masucci Michael Batty

Urban systems present hierarchical structures at many different scales. These are observed as administrative regional delimitations which are the outcome of complex geographical, political and historical processes which leave almost indelible footprints on infrastructure such as the street network. In this work, we uncover a set of hierarchies in Britain at different scales using percolation th...

2014
Juliano Vilaverde Schmitt Hélio Amante Miot

This study investigated the geographic distribution of dermatologists in Brazilian municipalities in relation to the population, regions of the country and human development index. We conducted an ecological study based on data from the 2010 census, the 2010 human development index, and the records of the Brazilian Society of Dermatology. 5565 municipalities and 6718 dermatologists were surveye...

Journal: :AJS; American journal of sociology 2015
Kenneth T Andrews Charles Seguin

The authors argue that group threat is a key driver of the adoption of new and controversial policies. Conceptualizing threat in spatial terms, they argue that group threat is activated through the joint occurrence of (1) proximity to threatening groups and (2) the population density of threatened groups. By analyzing the adoption of county and state "dry laws" banning alcohol from 1890 to 1919...

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