The Sunn-pest, Eurygaster integriceps Puton (Heteroptera: Scutelleridae), is the most important insect pest of wheat and barley in Iran. A demographic study was carried out in order to determine the effect of temperature on life history parameters of the pest. Life tables were constructed at four constant temperatures: 22, 25, 27, and 30 ± 1° C using Mahdavi wheat kernels as food. Finite and in...

INTRODUCTION Calcitonin (Ct) and carcinoembrional antigen (CEA) are widely used as tumor markers for the post-operative follow-up of patients with medullary thyroid carcinoma (MTC).In patients with elevated serum Ct and CEA their dynamics can be described by calculating the doubling time (DT) - the time, they need to double the serum concentration. Previous reports concluded that the Ct and CEA...

In most models of population dynamics, changes in population due to birth or harvesting are assumed to be time-independent, but many species reproduce or are caught only during a single period of the year. In this paper a single species stage-structured model with density-dependent maturation rate, birth pulse and harvesting pulse is formulated. Using the discrete dynamical system determined by...

Effects of temperature, adult feeding, and host instar on life table parameters of Venturia canescens Gravenhorst (Hymenoptera: Ichneumonidae) parasitizing larvae of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) were studied in the laboratory. Experimental adults lived under various regimes of temperature (15, 20, 25, and 30 degrees C), food supply (with or without access to honey), and h...

Rotavirus is a major cause of mortality in developing countries, and yet the dynamics of rotavirus in such settings are poorly understood. Rotavirus is typically less seasonal in the tropics, although recent observational studies have challenged the universality of this pattern. While numerous studies have examined the association between environmental factors and rotavirus incidence, here we e...

The beet armyworm (Spodoptera exigua Hübner) is an important pest of many agricultural crops all over the world. Most of the sugar beet growing regions in Iran are infested. In this study, the acute lethal effects of Pyriproxyfen, Spinosad, and Indoxacarb as well as sublethal effects of Pyriproxyfen on the 1 instar S. exigua were assessed by leaf dip bioassay method. Mortality was recorded 48 h...