this study was conducted during 3 years period (2002-2004). tick sampling was carried out randomly from domestic animals during seasonal activity of ticks from different parts of iran. 2170 ticks from 151 cattle, 629 sheep, 336 goats and 33 camels were collected. the occurance of tick infestation in cattle, sheep, goats and camels was 60%, 71.4%, 53% and 46 % respectively. sampled ticks of rhip...

the expansion of major cities regardless of the scientific planning principles has led to theemergence of negative urban development impacts in iran such as the degradation of natural resources andvarious forms of pollution. undoubtedly, urban rivers can enhance the ecological value of the earth to anoptimal extent. however, to benefit from these potentials, appropriate planning looks inevitabl...

Evolutionary hypotheses to explain the greater numbers of species in the tropics than the temperate zone include greater age and area, higher temperature and metabolic rates, and greater ecological opportunity. These ideas make contrasting predictions about the relationship between speciation processes and latitude, which I elaborate and evaluate. Available data suggest that per capita speciati...

Evolutionary hypotheses to explain the greater numbers of species in the tropics than the temperate zone include greater age and area, higher temperature and metabolic rates, and greater ecological opportunity. These ideas make contrasting predictions about the relationship between speciation processes and latitude, which I elaborate and evaluate. Available data suggest that per capita speciati...

Although theoretical models predict that the structure of a hybrid zone can change under a variety of scenarios, only a few empirical studies of hybrid zones have unequivocally demonstrated zone movement. These studies are rare because few data sets exist that include repeated, temporally spaced, samples of the same hybrid zone. We analysed mitochondrial DNA haplotype data from samples separate...

Urbanization may cause increased exposure levels to polycyclic aromatic hydrocarbons (PAHs) and associated health risks for over half of the world’s population living in cities, but little evidence has shown a direct spatial relationship between urbanization and soil PAH pollution. Based on the monitored PAH concentrations in 188 topsoil (0–5 cm) samples in Shenzhen, the most rapidly developing...

Hybridization can be an important evolutionary force by generating new species and influencing evolution of parental species in multiple ways, including introgression and the consequences of hybrid vigor. Determining the ecological processes underlying evolution in hybrid zones is difficult however because it requires examining changes in both genotypic frequencies over time and corresponding e...

Background Infant mortality is a major problem in Nepal, particularly in the mountainous region of the country. Objective To identify factors that contributes to the high rate of infant mortality in the mountain zone in Nepal. Method Data were derived from the 2011 Nepal Demographic and Health Survey (NDHS). Infant mortality was analyzed across three ecological zones in a sample of 5,306 live b...