Human capital raises rural incomes, but this effect is swamped by higher returns to human capital in urban markets. This leads to “brain drain” from rural areas. Populations grow more rapidly in rural counties that have a diversified employment base. Farm population grows faster (or declines more slowly) in counties with relatively high farm income, and nonfarm populations grow faster in counti...

Concerns about population growth historically revolved around the notion that there may be insufficient arable land, minerals or energy to meet the needs of an exponentially increasing population. Today they are compounded by fears that as wealth increases, so would consumption of natural resources, and that new technologies would enable further exploitation of these resources. Absent empirical...

the cotton bollworm, helicoverpa armigera (hübner), is one of the important polyphagous pests causing serious loss to many economically important crops in iran. the goal of this experiment was to study the age-stage, two-sex life table of h. armigera on different bean cultivars including white kidney bean (cultivars daneshkadeh, pak, and shokufa), red kidney bean (cultivars akhtar, naz, and say...

in the turfgrass industry, the need for salinity tolerant turfgrasses is increasing because of the increased use of saline and non-potable water. greenhouse container experiments were conducted to determine the relative salinity tolerance and growth responses of eleven native populations of tall fescue (festuca arundinacea schrub) (tf), including: semirom, mashhad, sanandaj, yasuj, yazd abad, d...

pIPHULA is the parallel program to estimate the parameters of a realistic model of population growth.

The purpose of this paper was to detail some important biological aspects of T. tonggol in coastal waters of Hormuzgan Province(Persian Gulf and Oman Sea). A total monthly data of 4383 individuals ranging from 25 to 124 cm fork length were collected from April 2015 to March 2016. The data were analyzed with FiSAT II software using the ELEFAN1  package  to estimate the  population parameters. Th...

We derive an alternative expression for a delayed logistic equation, assuming that the rate of change of the population depends on three components: growth, death, and intraspecific competition, with the delay in the growth component. In our formulation, we incorporate the delay in the growth term in a manner consistent with the rate of instantaneous decline in the population given by the model...

This study was conducted to collect comprehensive identification about Markhoz goat population and to simulate past dynamics of the population under its living conditions.Census data of the population size and the required parametersfor the simulation modelwere obtained frompublished data or were collected in its habitat in the last 3 years. In this study, past population dynamics and expected ...

Scombermorus commerson is one of the most important and commercial species in the Persian Gulf and Oman Sea. In order to adopt the responsible fishing patterns, it was necessary to estimate population dynamic parameters. Samples were collected randomly from five major traditional fish-landing sites in Chabahar, Jask, Bandar Abbas, Bandar Lengeh and Parsian in the north of the Persian Gulf ...

the growth parameters, mortality rates and exploitation population dynamic parameters and exploitation rate of psettodes erumei were assessed between july 2010 to june 2011 using length frequency analysis. the data were collected from landing sites of jask, bandar abass, kong and qeshm hormozgan province waters. using total weight (w) and total length (tl) data, the length- weight relationship ...