A microscopic phase field (MPF) model is formulated to describe quantitatively the core structure and energy of dislocations using ab initio data as input. Based on phase field microelasticity theory implemented in the slip plane using Green’s function to describe the longrange elastic interaction, the MPF model is a three-dimensional generalization of the Peierls model. Using the same generali...

PURPOSE This study measured the effects of sauna-induced dehydration (Dhy) and the effectiveness of rapid rehydration on muscle performance and EMG frequency spectrum changes associated with fatigue during isometric contractions. METHODS Knee extensor muscle strength during isometric maximal voluntary contraction (MVC) and endurance time at 25% and 70% of MVC (ET25 and ET70, respectively) wer...

Xenopus postvitellogenic oocytes resume meiosis in vitro upon exposure to insulin or insulin-like growth factor 1 (IGF-1) via a ras-dependent pathway, whereas stage IV (600 micron < diameter < 1000 micron) oocytes cannot. The aim of the present study was to determine which event(s) of the transduction pathway from IGF-1 receptor to maturation-promoting factor (MPF) activation is deficient in th...

The requirement of mitogen-activated protein kinase (MAPK) for the initiation of meiotic maturation in porcine oocytes was examined using U0126, an inhibitor of MAPK activator. Immunoblot analysis and kinase assay showed that U0126 inhibited the phosphorylation and activation of MAPK incompletely in porcine oocytes. In this condition, maturation/M-phase promoting factor (MPF) activity was also ...

M-phase entry in eukaryotic cells is driven by activation of MPF, a regulatory factor composed of cyclin B and the protein kinase p34(cdc2). In G2-arrested Xenopus oocytes, there is a stock of p34(cdc2)/cyclin B complexes (pre-MPF) which is maintained in an inactive state by p34(cdc2) phosphorylation on Thr14 and Tyr15. This suggests an important role for the p34(cdc2) inhibitory kinase(s) such...

Anti-tubulin antibodies and confocal immunofluorescence microscopy were used to examine the organization and regulation of cytoplasmic and cortical microtubuies during the first cell cycle of fertilized Xenopus eggs. Appearance of microtubuies in the egg cortex temporally coincided with the outgrowth of the sperm aster. Microtubuies of the sperm aster first reached the animal cortex at 0.25, (t...

To determine the energetic costs of rigid-body, median or paired-fin (MPF) swimming versus undulatory, body-caudal fin (BCF) swimming, we measured oxygen consumption as a function of swimming speed in two MPF swimming specialists, Schlegel's parrotfish and Picasso triggerfish. The parrotfish swam exclusively with the pectoral fins at prolonged swimming speeds up to 3.2 total lengths per second ...

The mammalian cell cycle is regulated by Cyclin-dependent kinases (Cdks) whose activity is strictly controlled by the physical association with regulatory subunits known as Cyclins and by the phosphorylation and dephosphorylation of catalytic subunits. In higher eukaryotes, Cdk2-cyclin A and Cdc2-cyclin B (MPF) are needed for the maintenance and progression of the S phase and mitosis, respectiv...

After a long period of quiescence at dictyate prophase I, termed the germinal vesicle (GV) stage, mammalian oocytes reenter meiosis by activating the Cdc2-cyclin B complex (maturation-promoting factor [MPF]). The activity of MPF is regulated by Wee1/Myt1 kinases and Cdc25 phosphatases. In this study, we demonstrate that the sequestration of components that regulate MPF activity in distinct subc...

OBJECTIVE To compare the pain level and complications during cataract surgery with topical anesthesia in Prechop MPF versus phacoemulsification. STUDY DESIGN Prospective randomized comparative study. MATERIAL AND METHOD One hundred patients, undergoing small incision cataract surgery under topical anesthesia, were allocated randomly to perform Prechop MPF (n = 50) or phacoemulsification (n ...