16,373 research outputs found

    Nature of band-gap states in V-doped TiO2 revealed by resonant photoemission

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    Band-gap states in V-doped TiO2 have been studied by photoemission spectroscopy over a range of photon energies encompassing the Ti 3p and V 3p core thresholds. The states show resonant enhancement at photon energies significantly higher than found for Ti 3d states introduced into TiO2 by oxygen deficiency or alkalimetal adsorbates. This demonstrates that the gap states relate to electrons trapped on dopant V cations rather than host Ti cations

    Reducing the Computational Cost of Deep Generative Models with Binary Neural Networks

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    Deep generative models provide a powerful set of tools to understand real-world data. But as these models improve, they increase in size and complexity, so their computational cost in memory and execution time grows. Using binary weights in neural networks is one method which has shown promise in reducing this cost. However, whether binary neural networks can be used in generative models is an open problem. In this work we show, for the first time, that we can successfully train generative models which utilize binary neural networks. This reduces the computational cost of the models massively. We develop a new class of binary weight normalization, and provide insights for architecture designs of these binarized generative models. We demonstrate that two state-of-the-art deep generative models, the ResNet VAE and Flow++ models, can be binarized effectively using these techniques. We train binary models that achieve loss values close to those of the regular models but are 90%-94% smaller in size, and also allow significant speed-ups in execution time

    Hysteresis phenomenon in turbulent convection

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    Coherent large-scale circulations of turbulent thermal convection in air have been studied experimentally in a rectangular box heated from below and cooled from above using Particle Image Velocimetry. The hysteresis phenomenon in turbulent convection was found by varying the temperature difference between the bottom and the top walls of the chamber (the Rayleigh number was changed within the range of 107−10810^7 - 10^8). The hysteresis loop comprises the one-cell and two-cells flow patterns while the aspect ratio is kept constant (A=2−2.23A=2 - 2.23). We found that the change of the sign of the degree of the anisotropy of turbulence was accompanied by the change of the flow pattern. The developed theory of coherent structures in turbulent convection (Elperin et al. 2002; 2005) is in agreement with the experimental observations. The observed coherent structures are superimposed on a small-scale turbulent convection. The redistribution of the turbulent heat flux plays a crucial role in the formation of coherent large-scale circulations in turbulent convection.Comment: 10 pages, 9 figures, REVTEX4, Experiments in Fluids, 2006, in pres

    Effet d’une souche non pathogùne de Fusarium oxysporum sur l’expression de la fusariose chez le palmier à huile (Elaeis guineensis Jacq.)

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    Cette Ă©tude avait pour objectif d’évaluer la rĂ©action vis-Ă -vis de la fusariose de plantules de palmier Ă  huile prĂ©munies auparavant d’une souche non pathogĂšne de Fusarium oxysporum. L’évaluation a portĂ© sur des plantules issues d’un croisement tolĂ©rant et d’un croisement non tolĂ©rant Ă  la fusariose. Les rĂ©sultats ont montrĂ©, qu’aprĂšs quatre mois d’inoculation de l’agent pathogĂšne, 0% et 2,5% de plants malades ont Ă©tĂ© observĂ©s respectivement chez les plantules issues du croisement tolĂ©rant et du croisement non tolĂ©rant Ă  la fusariose. Par contre, lorsque les plantules n’ont pas Ă©tĂ© prĂ©-inoculĂ©es avant avec la souche non pathogĂšne de Fusarium oxysporum, le pourcentage cumulĂ© de fusariose, aprĂšs quatre mois d’incubation de l’agent pathogĂšne, a variĂ© entre 7,5% et 12,5% pour le croisement tolĂ©rant et de 14,5% Ă  47,5% pour le croisement non tolĂ©rant Ă  la fusariose. Il ressort donc de l’étude que l’inoculation, Ă  un croisement sensible d’une souche non agressive de Fusarium oxysporum pouvait lui confĂ©rer le pouvoir fongitoxique et amĂ©liorer la fongitoxicitĂ© chez un croisement tolĂ©rant.Mots clĂ©s : Induction, fongitoxicitĂ©, agent non agressif, prĂ©munition

    Void Growth in BCC Metals Simulated with Molecular Dynamics using the Finnis-Sinclair Potential

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    The process of fracture in ductile metals involves the nucleation, growth, and linking of voids. This process takes place both at the low rates involved in typical engineering applications and at the high rates associated with dynamic fracture processes such as spallation. Here we study the growth of a void in a single crystal at high rates using molecular dynamics (MD) based on Finnis-Sinclair interatomic potentials for the body-centred cubic (bcc) metals V, Nb, Mo, Ta, and W. The use of the Finnis-Sinclair potential enables the study of plasticity associated with void growth at the atomic level at room temperature and strain rates from 10^9/s down to 10^6/s and systems as large as 128 million atoms. The atomistic systems are observed to undergo a transition from twinning at the higher end of this range to dislocation flow at the lower end. We analyze the simulations for the specific mechanisms of plasticity associated with void growth as dislocation loops are punched out to accommodate the growing void. We also analyse the process of nucleation and growth of voids in simulations of nanocrystalline Ta expanding at different strain rates. We comment on differences in the plasticity associated with void growth in the bcc metals compared to earlier studies in face-centred cubic (fcc) metals.Comment: 24 pages, 12 figure

    Cooperation across multiple game theoretical paradigms is increased by fear more than anger in selfish individuals.

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    Cooperative decisions are well predicted by stable individual differences in social values but it remains unclear how they may be modulated by emotions such as fear and anger. Moving beyond specific decision paradigms, we used a suite of economic games and investigated how experimental inductions of fear or anger affect latent factors of decision making in individuals with selfish or prosocial value orientations. We found that, relative to experimentally induced anger, induced fear elicited higher scores on a cooperation factor, and that this effect was entirely driven by selfish participants. In fact, induced fear brought selfish individuals to cooperate similarly to prosocial individuals, possibly as a (selfish) mean to seek protection in others. These results suggest that two basic threat-related emotions, fear and anger, differentially affect a generalized form of cooperation and that this effect is buffered by prosocial value orientation

    'Clinical Triad' findings in Klippel-feil patients

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    E-Poster - Congenital Deformity: no. 530It has been propagated that Klippel-Feil Syndrome (KFS) is associated with the clinical triad findings (CTF) of short neck, low posterior hairline, and limited range of motion. This study noted that CTFs are not consistently noted in KFS patients. KFS patients with extensive congenitally fused cervical segments were more likely to exhibit one of the components of CTF.postprin

    An Estimation of the Entomological Inoculation Rate for Ifakara: A Semi-Urban Area in a Region of Intense Malaria Transmission in Tanzania.

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    An entomological study on vectors of malaria and their relative contribution to Plasmodium falciparum transmission in the semi-urban area of Ifakara, south-eastern Tanzania, was conducted. A total of 32 houses were randomly sampled from the area and light trap catches (LTC) performed in one room in each house every 2 weeks for 1 year. A total of 147 448 mosquitoes were caught from 789 LTC; 26 134 Anopheles gambiae s.l., 615 A. funestus, 718 other anophelines and 119 981 culicines. More than 60% of the total A. gambiae s.l. were found in five (0.6%) LTCs, with a maximum of 5889 caught in a single trap. Of 505 A. gambiae s.l. speciated by polymerase chain reaction, 91.5% were found to be A. arabiensis. Plasmodium falciparum sporozoite enzyme-linked immunosorbent assay tests were performed on 10 108 anopheles mosquitoes and 39 (0.38%) were positive. Entomological inoculation rate (EIR) estimates were generated using a standard method and an alternative method that allows the calculation of confidence intervals based on a negative binomial distribution of sporozoite positive mosquitoes. Overall EIR estimates were similar; 31 vs. 29 [95% confidence interval (CI): 19, 44] infectious bites per annum, respectively. The EIR ranged from 4 (95% CI: 1, 17) in the cool season to 108 (95% CI: 69, 170) in the wet season and from 54 (95% CI: 30, 97) in the east of the town to 15 (95% CI: 8, 30) in the town centre. These estimates show large variations over short distances in time and space. They are all markedly lower than those reported from nearby rural areas and for other parts of Tanzania

    A Fetal-Maternal Shift of Blood Oxygen Affinity in an Australian Viviparous Lizard, Sphenomorphus quoyii (Reptilia, Scincidae)

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    Compared to adults, the oxygen affinity of blood from fetal Sphenomorphus quoyii is very much higher: P50 is approximately 70 Torr in adults and 30 Torr in nearly full term embryos (PC02= 17 Torr, T=34 degrees C). Following birth, oxygen affinity decreases gradually and adult values are approached after about 15 weeks, with the onset of winter retreat. Electrophoresis revealed a multiple hemoglobin system in both adults and embryos, but there were no apparent differences between them
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