Growth of Cu-1.1at.% Sn and Cu-1.7at.% In Alloy Single Crystals

Attempts have been made to grow large single crystals of Cu-1.1at.% Sn and Cu-1.7at.% In alloys from the melt by the Bridgman method. Microscopic observation of the chemically etched surfaces and sections of the alloy ingots has shown that they contain a few large grains, if the growing condition is properly chosen, but otherwise they consist of columnar grains. The growth direction of the columnar grains determined by the X-ray Laue method exhibits a slight preference of the and directions for the Cu-Sn alloy and the and directions for the Cu-In alloy. A concentration profile in the grain investigated by EPMA has shown an appreciable fluctuation in as-grown crystals and an annealing in vacuum at 900℃ for 100 hr has resulted in a homogenization. The alloy crystals thus heat-treated provide the specimens suitable to LEED studies

Tyrosine Kinase-Dependent Activation of Phospholipase Cγ Is Required for Calcium Transient in Xenopus Egg Fertilization

AbstractIn a previous study (K.-I. Sato et al., 1999, Dev. Biol. 209, 308–320), we presented evidence that a Src-related protein-tyrosine kinase (PTK), named Xyk, may act upstream of the calcium release in fertilization of the Xenopus egg. In the present study, we examined whether PTK activation of phospholipase Cγ (PLCγ) plays a role in the fertilization-induced calcium signaling. Immunoprecipitation studies show that Xenopus egg PLCγ is tyrosine phosphorylated and activated within a few minutes after fertilization but not after A23187-induced egg activation. Consistently, we observed a fertilization-induced association of PLCγ with Xyk activity that was not seen in A23187-activated eggs. A Src-specific PTK inhibitor, PP1, blocked effectively the fertilization-induced association of PLCγ with Xyk activity and up-regulation of PLCγ, when microinjected into the egg. In addition, a PLC inhibitor, U-73122, inhibited sperm-induced inositol 1,4,5-trisphosphate production and the calcium transient and subsequent calcium-dependent events such as cortical contraction, elevation of fertilization envelope, and tyrosine dephosphorylation of p42 MAP kinase, all of which were also inhibited by PP1. On the other hand, A23187 could cause the calcium response and calcium-dependent events in eggs injected with PP1 or U-73122. These results support the idea that Xenopus egg fertilization requires Src-family PTK-dependent PLCγ activity that acts upstream of the calcium-dependent signaling pathway

Evidence that phosphatidylinositol 3-kinase is involved in sperm-induced tyrosine kinase signaling in Xenopus egg fertilization

<p>Abstract</p> <p>Background</p> <p>Studies have examined the function of PI 3-kinase in the early developmental processes that operate in oocytes or early embryos of various species. However, the roles of egg-associated PI 3-kinase and Akt, especially in signal transduction at fertilization, are not well understood.</p> <p>Results</p> <p>Here we show that in <it>Xenopus </it>eggs, a potent inhibitor of phosphatidylinositol 3-kinase (PI 3-kinase), LY294002 inhibits sperm-induced activation of the tyrosine kinase Src and a transient increase in the intracellular concentration of Ca²⁺at fertilization. LY294002 also inhibits sperm-induced dephosphorylation of mitogen-activated protein kinase, breakdown of cyclin B2 and Mos, and first embryonic cleavage, all of which are events of Ca²⁺-dependent egg activation. In fertilized eggs, an 85-kDa subunit of PI 3-kinase (p85) undergoes a transient translocation to the low-density, detergent-insoluble membranes (membrane microdomains) where Src tyrosine kinase signaling is operating. However, the tyrosine phosphorylation of p85 in fertilized eggs is not as evident as that in H2O2-activated eggs, arguing against the possibility that PI 3-kinase is activated by Src phosphorylation. Nevertheless, sperm-induced activation of PI 3-kinase has been demonstrated by the finding that Akt, a serine/threonine-specific protein kinase, is phosphorylated at threonine-308. The threonine-phosphorylated Akt also localizes to the membrane microdomains of fertilized eggs. Application of bp(V), an inhibitor of PTEN that dephosphorylates PIP3, the enzymatic product of PI 3-kinase, promotes parthenogenetic activation of <it>Xenopus </it>eggs. In vitro kinase assays demonstrate that PIP3 activates Src in a dose-dependent manner.</p> <p>Conclusions</p> <p>These results suggest that PI 3-kinase is involved in sperm-induced egg activation via production of PIP3 that would act as a positive regulator of the Src signaling pathway in <it>Xenopus </it>fertilization.</p

Neurobiology of Depression and Anxiety in Parkinson's Disease

Depression and anxiety are common in Parkinson's disease (PD) and have important consequences on quality of life. These have long been recognized as frequent accompanying syndromes of PD, and several reports suggest that these are the causative process or risk factors that are present many years before the appearance of motor symptoms. The neurochemical changes in PD involving dopamine, norepinephrine, and serotonin might be related to the pathophysiology of depression and anxiety, but this is still not clear. Several studies showed that anxiety in PD patients occurs earlier than depression, during premotor phase, suggesting that there may be a link between the mechanisms that cause anxiety and PD. Whereas a recent study reported that PD patients with depression and anxiety were associated with different demographic and clinical features

SIGMA: Scala Internal Domain-Specific Languages for Model Manipulations

International audienceModel manipulation environments automate model operations such as model consistency checking and model transformation. A number of external model manipulation Domain-Specific Languages (DSL) have been proposed, in particular for the Eclipse Modeling Framework (EMF). While their higher levels of abstraction result in gains in expressiveness over general-purpose languages, their limitations in versatility, performance, and tool support together with the need to learn new languages may significantly contribute to accidental complexities. In this paper, we present Sigma, a family of internal DSLs embedded in Scala for EMF model consistency checking, model-to-model and model-to-text transformations. It combines the benefits of external model manipulation DSLs with general-purpose programming taking full advantage of Scala versatility, performance and tool support. The DSLs are compared to the state-of-the-art Epsilon languages in non-trivial model manipulation tasks that resulted in 20% to 70% reduction in code size and significantly better performance

Development of the Apparatus for High-Speed Decomposition of Sewage Sludge

We investigated the development of the apparatus for high-speed decomposition of sewage sludge. The decomposition mechanism was based on thermophilic oxic process of microorganism. Effect of additional stuff on the stable operation of the apparatus was examined by use of 6 kinds of carrier stuffs. Wood chips as an additional stuff into sewage sludge made the apparatus possible to operate stably and continuously. Decomposition of sewage sludge was carried out efficiency when the weight ratio of sewage sludge to wood chips was less than 10%. The influence of rice bran on the decomposition rate has been studied. The temperature in reaction tank rose with the addition of the rice bran. The decomposition rate of sewage sludge increased with a rise in the temperature. It was clarified that the rice bran was added to the sewage sludge to accelerate the decomposition. It is clear from the measurement of carbon dioxide concentration in exhaust that the decomposition reaction reached in the maximum about 12 hours after the beginning of reaction. The CO, evolution rate increased with a rise in the temperature. Total amount of carbon discharge in the exaust agreeded with the decrease of sewage sludge

Evidence for the Involvement of a Src-Related Tyrosine Kinase inXenopusEgg Activation

AbstractRecently, we have purified a Src-related tyrosine kinase, namedXenopustyrosine kinase (Xyk), from oocytes ofXenopus laevisand found that the enzyme is activated within 1 min following fertilization [Satoet al.(1996)J. Biol. Chem.271, 13250–13257]. A concomitant translocation of a part of the activated enzyme from the membrane fraction to the cytosolic fraction was also observed. In the present study, we show that parthenogenetic egg activation by a synthetic RGDS peptide [Y. Iwao and T. Fujimura, T. (1996)Dev. Biol.177, 558–567], an integrin-interacting peptide, but not by electrical shock or the calcium ionophore A23187 causes the kinase activation, tyrosine phosphorylation, and translocation of Xyk. A synthetic tyrosine kinase-specific inhibitor peptide was employed to analyze the importance of the Xyk activity in egg activation. We found that the peptide inhibits the kinase activity of purified Xyk at IC50of 8 μM. Further, egg activation induced by sperm or RGDS peptide but not by A23187 was inhibited by microinjection of the peptide. In the peptide-microinjected eggs, penetration of the sperm nucleus into the egg cytoplasm and meiotic resumption in the egg were blocked. Indirect immunofluorescence study demonstrates that Xyk is exclusively localized to the cortex ofXenopuseggs, indicating that Xyk can function in close proximity to the sperm–egg or RGDS peptide–egg interaction site. Taken together, these data suggest that the tyrosine kinase Xyk plays an important role in the early events ofXenopusegg activation in a manner independent or upstream of calcium signaling

Alleviation of Brain Hypoperfusion after Preventative Treatment with Lomerizine in an Elderly Migraineur with Aura

Previous studies of brain single-photon emission tomography (SPECT) showed changes of regional cerebral blood flow (rCBF) in migraineurs during prodromes or headache attacks. Little is known about how successful medication of migraine prevention can reflect rCBF in migraineurs. We highlighted alternation of brain SPECT findings in a migraineur with aura before and after prophylactic treatment with lomerizine, a calcium channel blocker. A 70-year-old man with migraine developed visual disturbance frequently at walking exercise for the recent 3 months. After this visual attack, a mild-degree of throbbing headache occured occasionally. Brain SPECT using 99mTc-ethyl cysteinate dimer was performed at interictal time of migraine. Brain SPECT before lomerizine treatment revealed hypoperfusion in the frontal, parietal, and occipital regions. He was diagnosed with recurrence of migraine with aura (MA). Lomerizine (10 mg/day, po) was administered for 3 months. MA and visual aura without headache were dramatically improved. Migraine attacks and visual disturbance were not induced at exercise. At 3 months after lomerizine medication, brain SPECT showed remarkable increase of rCBF. These SPECT changes of our patient indicated that antimigraine mechanism of lomerizine could contribute to restoration of cerebral hypoperfusion