objective: in recent years, antiviral drugs have been used widely in the glob to prevent and treat viral diseases. they injected into eggs to eliminate pathogens and prevent of egg transmission of disease, but the adverse effects of drugs have always been a major concern. there is little information available about the safety of antiviral drugs in the embryonated eggs of birds. the objective of...

in order to study dry matter accumulation in different developmental stages and photoassimilates remobilization in bread wheat genotypes, a field experiment was carried out using a split split plot design based on a randomized complete block design with three replications in torogh agricultural and natural resources research station (mashhad, iran) in 2006-2007 and 2007-2008. main plots were as...

Neuroblasts generate neurons with different functions by asymmetric cell division, cell cycle exit and differentiation. The underlying transcriptional regulatory pathways remain elusive. Here, we performed genetic screens in C. elegans and identified three evolutionarily conserved transcription factors (TFs) essential for Q neuroblast lineage progression. Through live cell imaging and genetic a...

We report the hemodynamic parameters of stage 18, 21, 24, and 27 chick embryos (from 3 to 5 days of incubation). Dorsal aortic blood velocity and mean vitelline artery blood pressure are measured with a 20 MHz pulsed-Doppler meter and servo-null pressure system respectively. We also measure heart rate, dorsal aortic diameter and embryo weight of each developmental stage. From these data, we cal...

UNLABELLED A defining characteristic of Chlamydia spp. is their developmental cycle characterized by outer membrane transformations of cysteine bonds among cysteine-rich outer membrane proteins. The reduction-oxidation states of host cell compartments were monitored during the developmental cycle using live fluorescence microscopy. Organelle redox states were studied using redox-sensitive green...

Blastomeres of the early mouse embryo are thought to be equivalent in their developmental properties at least until the eight-cell stage. However, the experiments that have led to this conclusion could not have taken into account either the spatial origin of individual blastomeres or the spatial allocation and fate of their progeny. We have therefore readdressed this issue having defined cell l...

T he evolution of brain structure and function has long fascinated biologists. This fascination was initially prompted by the observation that allometric relationships exist between the size of the brain—or brain region—and body size across a wide range of vertebrates (1). Besides random drift, two main ideas have been advanced to explain how brains evolve, and both have found considerable supp...

ABSTRACTThe coincidence of retirement and aging, experienced in the later stages of life, can trigger a recurrence of the bipolar tensions of earlier stages described in Erikson's model of personality development. The model provides a means for retirees to understand the ground from which their present identity has developed and how the psychodynamics of previous life stages can be reactivated ...

Leaves between species vary in their size, serration, complexity, and shape. However, phylogeny is not the only predictor of leaf morphology. The shape of a leaf is the result of intricate developmental processes, including heteroblastic progression (changes in leaf size and shape at different nodes) and the developmental stage of an organ. The leaflets that arise from complex leaves are additi...