97,933 research outputs found
Radial distribution functions of water: Models vs experiments
No full textWe study the temperature behavior of the first four peaks of the oxygen-oxygen radial distribution function of water, simulated by the TIP4P/2005, MB-pol, TIP5P, and SPC/E models and compare to experimental X-ray diffraction data, including a new measurement which extends down to 235 K [H. Pathak et al., J. Chem. Phys. 150, 224506 (2019)]. We find the overall best agreement using the MB-pol and TIP4P/2005 models. We observe, upon cooling, a minimum in the position of the second shell simulated with TIP4P/2005 and SPC/E potentials, located close to the temperature of maximum density. We also calculated the two-body entropy and the contributions coming from the first, second, and outer shells to this quantity. We show that, even if the main contribution comes from the first shell, the contribution of the second shell can become important at low temperature. While real water appears to be less ordered at short distance than obtained by any of the potentials, the different water potentials show more or less order compared to the experiments depending on the considered length-scale
Effect of organophosphorus insecticides and their metabolites on astroglial cell proliferation
No full textThough little attention has been given to the possibility that glial cells may represent a target for the developmental neurotoxicity of organophosphorus (OP) insecticides, recent evidence, obtained in particular with chlorpyrifos (CP), suggests that developmental exposure to this compound may indeed target astrocyles. To substantiate and expand these observations, we carried out a series of in vitro studies utilizing fetal rat astrocytes and a human astrocytoma cell line. 1321N1 cells, to investigate the effect of the OPs CP, diazinon (DZ) and parathion (P), their oxygen analogs chlorpyrifos oxon (CPO), diazoxon (DZO) and paraoxon (PO), and their metabolites 3,5,6-trichloro-2-pyridinol (TCP), 2-isopropyl-6-methyl-4-pyrimidoI (IMP) and para-nitrophenol (PNP), on cell proliferation. In fetal rat astrocytes and astrocytoma cells maintained in serum, CP, DZ, P, CPO, DZO, and PO induced a concentration-dependent inhibition in [3 H]thymidine incorporation with a very similar potency (IC50 between 45 and 57 mu M). Among the other metabolites, PNP was the most potent (IC50 = 70-80 mu M), while TCP and IMP were much less effective (IC50 > 100 mu M)Cytotoxicity appears to account only for a small part of the effect on DNA synthesis. OP insecticides and their oxons were three-to six-fold more potent in inhibiting [H-3]thyrpidine incorporation when cells were synchronized in the G(0)/G(1) phase of the cell cycle and re-stimulated by carbachol or epidermal growth factor. These results suggest that OP insecticides and their G(0)/G(1) to the S/G(2) phase of the cell cycle may be particularly sensitive to the action of these compounds
Ensuring safety of policies learned by reinforcement: Reaching objects in the presence of obstacles with the iCub
No full textA UTD Diffraction Coefficient for a Corner Formed by Truncation of Edges in an Otherwise Smooth Curved Surface
No full textMonitoring of Nitrogen Leaching from a Tropical Paddy in Thailand
No full textRosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 6 (2004): B. Pathak, F. Kazama, and I. Toshiaki. Monitoring of Nitrogen Leaching from a Tropical Paddy in Thailand. (December 2004)
A review of some UTD developments - past and present
No full textA review of some early UTD developments following Keller's introduction of the GTD is described. That is followed bya description of more recent developments and future trends in UTD for solving problems of predicting the performance of antennas on complex metallic structures with thin material coating
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