in which r and K are positive numbers; r is related to the reproduction of the species while K is related to the capacity of the environment to sustain the population. It is assumed that there is no immigration or emigration and other characteristics such as age dependence and interactions with other species are assumed to be not significant. Elementary analysis of (1.1) indicates that the solu...

On 1st January 2003, the population of metropolitan France was estimated to be 59.6 million, plus a further 1.8 million living in the French overseas departments, bringing the total to 61.4 million [1]. The population in metropolitan France increased by nearly 290,000 people (+ 0.5%) in 2002. This was very similar to 2001, with a slight fall in the surplus of births over deaths (natural increas...

Climate change is expected to cause mass human migration, including immigration across international borders. This study quantitatively examines the linkages among variations in climate, agricultural yields, and people's migration responses by using an instrumental variables approach. Our method allows us to identify the relationship between crop yields and migration without explicitly controll...

The datasets contained in this article are simulated data with respect to Sickle Cell Anaemia (SCA) in order to examine the mathematical inheritance formation of the SCA disease. The simulation is done using Monte Carlos Simulation (MCS) Technique to complement the Physical Simulation Smith's Statistical (PSSS) package used as random number generator for birth simulation. One hundred and fifty-...

The emigration of residents following the Fukushima nuclear accident has resulted in aging and depopulation problems in radiation-contaminated areas. The recovery of affected areas, and even those areas with low radioactive pollution levels, is still heavily affected by this problem. This slow recovery consequently affects immigration patterns. This review aims to present possible factors that ...

BACKGROUND There has been substantial immigration of physicians to developed countries, much of it coming from lower-income countries. Although the recipient nations and the immigrating physicians benefit from this migration, less developed countries lose important health capabilities as a result of the loss of physicians. METHODS Data on the countries of origin, based on countries of medical...

In two of the busiest migration corridors of the twentieth century, namely Mexico-US and Turkey-Germany, migrants can today be dual citizens. However, the acceptance of dual citizenship did not occur automatically; instead, it followed a period of legal statuses short of full citizenship. This paper conceptualises such statuses as quasi-citizenship, a transitional equilibrium between the absenc...

Biogeography Based Optimization (BBO) is a swarm based optimization algorithm that has shown impressive performance over other Evolutionary Algorithms (EAs). Immigration Refusal Biogeography Based Optimization (IRBBO), Enhanced Biogeography Based Optimization (EBBO), Blended Migration are the most improved version of BBO and are known as migration variants of BBO. In this paper, a new concept o...