953 resultados para James, Saint and apostle, the Less.
Resumo:
Memory is sensitive to the short-acting anesthetic (2,6-diisopropylphenol) propofol, but the underlying mechanism is little known. Here, we have examined the effects of propofol on synaptic plasticity in the CA1 region of the hippocampus of anesthetized rats. We found that low dose of propofol (20 mg/kg, i.p.) did not affect the basal transmission, but enhanced prominently the development of long-term depression (LTD) and impaired the maintenance of long-term potentiation (LTP). The impairment of LTP maintenance and enhancement of LTD development may contribute to propofol-induced deficits in memory following propofol anesthesia. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.
Resumo:
The objective of the study was to assess the economic value of ecosystem services in the Bay of Bengal.The manin aim was to support the development of a Strategic Action Plan (SAP). Findings included: economic consequences of ecosystem change; potential economic instruments to strengthen sustainable management; and recommendations on next steps in using economic valuation.
Resumo:
Chronic exposure to morphine can induce drug addiction and neural injury, but the exact mechanism is not fully understood. Here we show that morphine induces autophagy in neuroblastoma SH-SY5Y cells and in the rat hippocampus. Pharmacological approach shows that this effect appears to be mediated by PTX-sensitive G protein-coupled receptors signaling cascade. Morphine increases Beclin 1 expression and reduces the interaction between Beclin 1 and Bcl-2, thus releasing Beclin 1 for its pro-autophagic activity. Bcl-2 overexpression inhibits morphine-induced autophagy, whereas knockdown of Beclin 1 or knockout of ATG5 prevents morphine-induced autophagy. In addition, chronic treatment with morphine induces cell death, which is increased by autophagy inhibition through Beclin 1 RNAi. Our data are the first to reveal that Beclin 1 and ATG5 play key roles in morphine-induced autophagy, which may contribute to morphine-induced neuronal injury.
Resumo:
The fisheries of Lakes Victoria and Kyoga have changed from the native tilapiine species and are now dominated by two introduced species; Nile perch and Nile tilapia, and one native species; Rastrineobola argentea (mukene). Because of the differences in the size of the species, it may be necessary to change the type and sizes of nets used.
Resumo:
As a novel implementation of the static random access memory (SRAM), the tunneling SRAM (TSRAM) uses the negative differential resistance of tunnel diodes (TD’s) and potentially offers considerable improvements in both standby power dissipation and integration density compared to the conventional CMOS SRAM. TSRAM has not yet been realized with a useful bit capacity mainly because the level of uniformity required of the nanoscale TD’s has been demanding and difficult to achieve. In this letter, we propose a Monte Carlo approach for estimating the yield of TSRAM cells and show that by optimizing the cell’s external circuit parameters, we can relax the allowable tolerance of a key device parameter of a resonant-TD-(RTD) based cell by three times.
Resumo:
We have cloned a mouse homologue (designated Myak) of the yeast protein kinase YAK1. The 1210 aa open reading frame contains a putative protein kinase domain, nuclear localization sequences and PEST sequences. Myak appears to be a member of a growing family of YAK1-related genes that include Drosophila and human Minibrain as well as a recently identified rat gene ANPK that encode a steroid hormone receptor interacting protein. RNA blot analysis revealed that Myak is expressed at low levels ubiquitously but at high levels in reproductive tissues, including testis, epididymis, ovary, uterus, and mammary gland, as well as in brain and kidney. In situ hybridization analysis on selected tissues revealed that Myak is particularly abundant in the hormonally modulated epithelia of the epididymis, mammary gland, and uterus, in round spermatids in the testis, and in the corpora lutea in the ovary, Myak is also highly expressed in the aqueduct of the adult brain and in the brain and spinal cord of day 12.5 embryos, Mol. Reprod. Dev. 55:372-378, 2000. (C) 2000 Wiley-Liss, Inc.
Resumo:
We report the effects of thermal annealing performed in N2 or O2 ambient at 1200 °C on the structural and optical properties of Er silicate films having different compositions (Er2Si O 5,Er2 Si2 O7, and their mixture). We demonstrate that the chemical composition of the stoichiometric films is preserved after the thermal treatments. All different crystalline structures formed after the thermal annealing are identified. Thermal treatments in O 2 lead to a strong enhancement of the photoluminescence intensity, owing to the efficient reduction of defect density. In particular the highest optical efficiency is associated to Er ions in the α phase of Er 2 Si2 O7. © 2008 American Institute of Physics.
Resumo:
We present a method for characterizing the propagation of the magnetic flux in an artificially drilled bulk high-temperature superconductor (HTS) during a pulsed-field magnetization. As the magnetic pulse penetrates the cylindrical sample, the magnetic flux density is measured simultaneously in 16 holes by means of microcoils that are placed across the median plane, i.e. at an equal distance from the top and bottom surfaces, and close to the surface of the sample. We discuss the time evolution of the magnetic flux density in the holes during a pulse and measure the time taken by the external magnetic flux to reach each hole. Our data show that the flux front moves faster in the median plane than on the surface when penetrating the sample edge; it then proceeds faster along the surface than in the bulk as it penetrates the sample further. Once the pulse is over, the trapped flux density inside the central hole is found to be about twice as large in the median plane than on the surface. This ratio is confirmed by modelling.
Resumo:
In the modern engineering design cycle the use of computational tools becomes a neces- sity. The complexity of the engineering systems under consideration for design increases dramatically as the demands for advanced and innovative design concepts and engineering products is expanding. At the same time the advancements in the available technology in terms of computational resources and power, as well as the intelligence of the design software, accommodate these demands and make them a viable approach towards the chal- lenge of real-world engineering problems. This class of design optimisation problems is by nature multi-disciplinary. In the present work we establish enhanced optimisation capabil- ities within the Nimrod/O tool for massively distributed execution of computational tasks through cluster and computational grid resources, and develop the potential to combine and benefit from all the possible available technological advancements, both software and hardware. We develop the interface between a Free Form Deformation geometry manage- ment in-house code with the 2D airfoil aerodynamic efficiency evaluation tool XFoil, and the well established multi-objective heuristic optimisation algorithm NSGA-II. A simple airfoil design problem has been defined to demonstrate the functionality of the design sys- tem, but also to accommodate a framework for future developments and testing with other state-of-the-art optimisation algorithms such as the Multi-Objective Genetic Algorithm (MOGA) and the Multi-Objective Tabu Search (MOTS) techniques. Ultimately, heav- ily computationally expensive industrial design cases can be realised within the presented framework that could not be investigated before. © 2012 by the authors. Published by the American Institute of Aeronautics and Astronautics, Inc.
Resumo:
In the modern engineering design cycle the use of computational tools becomes a necessity. The complexity of the engineering systems under consideration for design increases dramatically as the demands for advanced and innovative design concepts and engineering products is expanding. At the same time the advancements in the available technology in terms of computational resources and power, as well as the intelligence of the design software, accommodate these demands and make them a viable approach towards the challenge of real-world engineering problems. This class of design optimisation problems is by nature multi-disciplinary. In the present work we establish enhanced optimisation capabilities within the Nimrod/O tool for massively distributed execution of computational tasks through cluster and computational grid resources, and develop the potential to combine and benefit from all the possible available technological advancements, both software and hardware. We develop the interface between a Free Form Deformation geometry management in-house code with the 2D airfoil aerodynamic efficiency evaluation tool XFoil, and the well established multi-objective heuristic optimisation algorithm NSGA-II. A simple airfoil design problem has been defined to demonstrate the functionality of the design system, but also to accommodate a framework for future developments and testing with other state-of-the-art optimisation algorithms such as the Multi-Objective Genetic Algorithm (MOGA) and the Multi-Objective Tabu Search (MOTS) techniques. Ultimately, heavily computationally expensive industrial design cases can be realised within the presented framework that could not be investigated before. ©2012 AIAA.