This paper presents a study of the relationship between Electrical Discharge Machining (EDM) parameters on the EDM efficiency factors using a full factorial design, based on pulse on-time, duty cycle and tool polarity parameters in EDM machining of AISI H13 tool steel. The results show that, in positive polarity, the plasma flushing efficiency and pulse efficiency increase according to the puls...

Delineation of apical and basolateral membrane domains is a critical step in the epithelialization of the outer layer of cells in the embryo. We have examined the initiation of polarized membrane traffic in Xenopus and show that membrane traffic is not polarized in oocytes but polarized membrane domains appear at first cleavage. The following proteins encoded by injected RNA transcripts were us...

The animal-vegetal (A-V) axis is already set in unfertilized eggs. It plays crucial roles in coordinating germ-layer formation. However, how the A-V axis is set has not been well studied. In ascidians, unfertilized eggs are already polarized along the axis in terms of cellular components. This polarization occurs during oocyte maturation. Oocytes within the gonad have the germinal vesicle (GV) ...

Prior sequence analysis studies have suggested that bacterial ribonuclease (RNase) Ds comprise a complete domain that is found also in Homo sapiens polymyositis-scleroderma overlap syndrome 100 kDa autoantigen and Werner syndrome protein. This RNase D 3'-->5' exoribonuclease domain was predicted to have a structure and mechanism of action similar to the 3'-->5' exodeoxyibonuclease (proofreading...

Progesterone triggers the resumption of meiosis in the amphibian oocyte through a signaling system at the plasma membrane. Analysis of [(3)H]ouabain and [(3)H]progesterone binding to the plasma membrane of the Rana pipiens oocyte indicates that progesterone competes with ouabain for a low affinity ouabain binding site on a 112kDa alpha1-subunit of the membrane Na/K-ATPase. Published amino acid ...

During Drosophila development, the formin actin nucleator Cappuccino (Capu) helps build a cytoplasmic actin mesh throughout the oocyte. Loss of Capu leads to female sterility, presumably because polarity determinants fail to localize properly in the absence of the mesh. To gain deeper insight into how Capu builds this actin mesh, we systematically characterized seven capu alleles, which have mi...

The telotrophic ovariole of Rhodnius prolixus is richly endowed with microtubules (MTs). An extensive, stable array of MTs packs the trophic core and trophic cords which link the nurse cell compartments to the growing oocytes. This system is excellent to study MT-based transport as the MTs are believed to play a role in transport of nurse cell-produced mitochondria, ribosomes, and mRNAs to the ...

The anterior region of the Drosophila embryonic pattern is determined by a gradient of the bicoid (bcd) protein. The correct formation of this gradient requires the localization of bcd RNA to the anterior pole of the egg. Here we use a wholemount in situ technique to examine the process of bcd RNA localization during oogenesis and embryogenesis. While bcd protein becomes distributed in a gradie...

CD44 is a polymorphic and polyfunctional transmembrane glycoprotein widely expressed in many types of cells. Here, the expression of this protein on human membrana granulosa was studied by two techniques. Using confocal laser scanning microscopy (CLSM) with the mouse monoclonal antibody to human CD44 (clone G44-26), cells immunoreactive for CD44 were observed in both cumulus and mural granulosa...