race-specific resistance of wheat to yellow rust caused by puccinia striiformis f. sp. tritici has been reported as short-lived. partial resistance, a kind of quantitative resistance, has been reported to be more stable. partial resistance in terms of slow rusting parameters including final rust severity (frs), apparent infection rate (r), relative area under disease progress curve (raudpc), an...

Neuronal growth cones are the highly motile structures at the tip of axons that can detect guidance cues in the environment and transduce this information into directional movement towards the appropriate target cell. To fully understand how guidance information is transmitted from the cell surface to the underlying dynamic cytoskeletal networks, one needs a model system suitable for live cell ...

Serotonin (5-HT) regulates the development of cerebral cortex, but 5-HT receptors mediating the effects are poorly understood. We investigated roles of 5-HT2A receptor in dendritic growth cones using dissociation culture of rat cerebral cortex. Neurons at embryonic day 16 were cultured for 4 days and treated with 5-HT2A/2C receptor agonist (DOI) for 4h. DOI increased the size of growth cone per...

The complex process of axon guidance is largely driven by the growth cone, which is the dynamic motile structure at the tip of the growing axon. During axon outgrowth, the growth cone must integrate multiple sources of guidance cue information to modulate its cytoskeleton in order to propel the growth cone forward and accurately navigate to find its specific targets(1). How this integration occ...

The motile tips of elongating axons consist of growth cones from which microspikes protrude. Cytochalasin B causes retraction of microspikes, rounding-up of growth cones, and cessation of axon elongation. Drug withdrawal is followed by resumption of growth cone and microspike activity and of axon elongation. In contrast, colchicine causes shortening and retraction of axons, but it does not init...

the big eye kilka, clupeonella grimmi, is a marine fish living in depth of 20 to 200 meter of the caspian sea. its eye and retina were processed for histological and sem studies. paraffin embedded retina was cut radially and tangentially in 5 ?m thickness and stained with hematoxylin and eosin method. the unstained sections were manipulated for sem image observations. tangential retinal section...

one of the most valid and efficient models of long rod projectile penetration in homogeneous targets is tate and alekseevskii’s (a&t;) model. based on tate’s model, the present research tries to calculate the optimum speeds to achieve the maximum penetration depth in the homogeneous targets. the proposed collision speed-penetration depth diagrams are developed using tate’s model. in this way, v...

Coherent twin boundaries (CTBs) in nano-twinned materials could improve crack resistance. However, the role of the CTBs during crack penetration has never been explored at atomic scale. Our in situ observation on nano-twinned Ag under a high resolution transmission electron microscope (HRTEM) reveals the dynamic processes of a crack penetration across the CTBs, which involve alternated crack ti...