This paper shows, in a two-sector Malthusian model of endogenous population growth, that output per capita, population density, and industrialization depend upon the labor intensity of agricultural production. Because the diminishing returns to labor are less pronounced, high labor intensity (as in rice production) leads not only to a larger population density but also to lower output per capit...

Individual learning and social learning are two primary abilities supporting cultural evolution. Conditions for their evolution have mostly been studied by investigating gene frequency dynamics, which essentially implies constant population size. Predictions from such "static" models may only be of partial relevance to the evolution of advanced individual learning in modern humans, because mode...

T he Netherlands is a small country in Western Europe, located on the North Sea coastal area at the mouth of the rivers Rhine and Meuse, bordering Belgium and Germany. The territory of the Netherlands covers 41,574 km of which 7,636 km are water. About one-quarter of the country, especially the western part where land has been reclaimed from the sea since the 16th century, actually lies below s...

This paper extends the Lotka system of stable population equations to any population. The authors present this new general system and describe its duality with the recent Preston-Coale system. They derive these results by considering the calculus of change on the surface of population density defined over age and time. They show that analysis of this Lexis surface leads to all the known fund...

Explicit density-dependence differs from density-vagueness in the sort of regulation imposed on populations. Explicit density-dependence implies regulation toward a central equilibrium point, whereas density-vagueness implies population change away from the two extremes of extinction and immense densities. Density-vagueness does not much concern regulation within the broad range of medial densi...

striped rice stem borer, chilo suppressalis (lepidoptera: pyralidae) is one of the major pests in north part of iran which causes serious damage. the last larval instar overwinters in the stem of weeds around the fields. regarding the importance of weeds as overwintering habitat, population density of larvae was studied in three areas; low-, mid-, and up-lands of mazandaran province and also on...

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...

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...

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 ...

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...