The Diagnostic Development Group at the Laboratory for Laser Energetics has endeavored to build a stand-alone, remotely operated streak camera with comprehensive autofocus and self-calibration capability. Designated as the Rochester Optical Streak System (ROSS), it is a generic streak camera platform, capable of accepting a variety of streak tubes. The system performance is limited by the insta...

The origin of the prelung cells was determined by tracing the movements of [H]thymidinelabelled grafts excised from medium-streak to 4-somite stage chick embryos and transplanted to the epiblast, streak, and endoderm-mesoderm of similarly staged recipient embryos. At the medium-streak stage the prelung endoderm cells are in the anterior third of the primitive streak; they shortly begin to migra...

The chicken homebox containing gene, CdxA (formerly CHox-cad), was previously shown to be expressed during gastrulation. Localization of CdxA transcripts by in situ hybridization to tissue sections revealed that, during gastrulation, expression of this gene exhibits a posterior localization along the primitive streak. The transcripts are localized to epiblast cells in the vicinity of the primit...

a seventeen-years old woman was presented with infertility and primary amenorrhea. she had normal stature, femate phenotype and normal development of breasts, external genitalia, vagina and cervix. pelvic examination showed a large lobulated mass. on sonography there was a mass with probable origin of ovary. paraclinic tests were carried out. gonadotropins were in postmeno pausal limits. alpha ...

We have used carbocyanine dyes to fate map the primitive streak in the early chick embryo, from stages 3+ (mid-primitive streak) to 9 (8 somites). We show that presumptive notochord, foregut and medial somite do not originate solely from Hensen's node, but also from the anterior primitive streak. At early stages (4- and 4), there is no correlation between specific anteroposterior levels of the ...

Streak cameras are used to record the time history of laser pulses and experimental signals at LLE. However, space charge effects can distort images recorded on the phosphor screen of streak cameras, making it difficult to impossible to accurately interpret the image. Space charge effects are caused by the interactions between the photoelectrons while in transit in the streak tube. These intera...

The primitive streak is the organizing center for amniote gastrulation. It defines the future embryonic midline and serves as a conduit of cell migration for germ layer formation. The migration patterns of endodermal and mesodermal precursors through the streak have been studied in great detail. Additional new breakthroughs recently have revealed the cell biological and molecular mechanisms tha...

drop plate technique has a priority and preference compared with the spread plate procedure, because of less time, quantity of media, effort requirement, little incubator space, and less labor intensive. the objective of this research was to compare the accuracy and fidelity of drop plate method vs. spread plate method by parametric and nonparametric statistical tests. for bacterial enumeration...

The body plan of all higher organisms develops during gastrulation. Gastrulation results from the integration of cell proliferation, differentiation and migration of thousands of cells. In the chick embryo gastrulation starts with the formation of the primitive streak, the site of invagination of mesoderm and endoderm cells, from cells overlaying Koller's Sickle. Streak formation is associated ...

Morphogenetic movements occurring during formation of the primitive streak in the chick embryo are of a periodic nature, with a mean frequency of one pulse every 2.6 min. The period of the oscillatory movement is shown to be temperature-dependent. The onset of these pulses of movement can be seen as a slow wave starting at the posterior end of the embryo and making its way towards the anterior ...