10 research outputs found

    FeDXL: Provable Federated Learning for Deep X-Risk Optimization

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    In this paper, we tackle a novel federated learning (FL) problem for optimizing a family of X-risks, to which no existing FL algorithms are applicable. In particular, the objective has the form of EzS1f(EzS2(w;z,z))\mathbb E_{z\sim S_1} f(\mathbb E_{z'\sim S_2} \ell(w; z, z')), where two sets of data S1,S2S_1, S_2 are distributed over multiple machines, ()\ell(\cdot) is a pairwise loss that only depends on the prediction outputs of the input data pairs (z,z)(z, z'), and f()f(\cdot) is possibly a non-linear non-convex function. This problem has important applications in machine learning, e.g., AUROC maximization with a pairwise loss, and partial AUROC maximization with a compositional loss. The challenges for designing an FL algorithm lie in the non-decomposability of the objective over multiple machines and the interdependency between different machines. To address the challenges, we propose an active-passive decomposition framework that decouples the gradient's components with two types, namely active parts and passive parts, where the active parts depend on local data that are computed with the local model and the passive parts depend on other machines that are communicated/computed based on historical models and samples. Under this framework, we develop two provable FL algorithms (FeDXL) for handling linear and nonlinear ff, respectively, based on federated averaging and merging. We develop a novel theoretical analysis to combat the latency of the passive parts and the interdependency between the local model parameters and the involved data for computing local gradient estimators. We establish both iteration and communication complexities and show that using the historical samples and models for computing the passive parts do not degrade the complexities. We conduct empirical studies of FeDXL for deep AUROC and partial AUROC maximization, and demonstrate their performance compared with several baselines

    Two parasitic ciliates (Protozoa: Ciliophora: Phyllopharyngea) isolated from respiratory-mucus of an unhealthy beluga whale: characterization, phylogeny and an assessment of morphological adaptations

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    Abstract Ciliates occur in the blowholes of marine mammals, but our understanding of their biology is poor. Consequently, we investigated an infestation of ciliates in an unhealthy, captive beluga whale that was exhibiting accelerated breathing, leukocytosis and expulsion of unusually large amounts of viscous sputum. This sputum contained ~104 ciliates mL-1 (when healthy, numbers were ten- to 100-fold lower). One known ciliate species, Planilamina ovata, is fully characterized, and a new species, Kyaroikeus paracetarius sp. nov., is here described. The new species is established based on its larger number of left kineties over its only congener. Sequences of small-subunit rDNA, large-subunit rDNA and ITS1-5.8S-ITS2 regions of these two taxa were used in phylogenetic analyses, inferring that Kyaroikeus and Planilamina have close affinity with the free-living family Dysteriidae, contradicting their morphology-based assignment to the family Kyaroikeidae. We suggest that Kyaroikeidae be relegated to subfamily status. Finally, by comparing parasitic species with free-living taxa, we suggest how these ciliates have adapted to their unique environment and how they may have initially invaded the host. We provide essential data and concepts for the continued evaluation of ciliate-parasites in whale blowholes.</jats:p

    Processing of emotional faces in congenital amusia: An emotional music priming event-related potential study

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    Congenital amusia is characterized by lifelong impairments in music perception and processing. It is unclear whether pitch detection deficits impact amusic individuals perception of musical emotion. In the current work, 19 amusics and 21 healthy controls were subjected to electroencephalography (EEG) while being exposed to music excerpts and emotional faces. We assessed each individual&#39;s ability to discriminate positive- and negative-valenced emotional faces and analyzed electrophysiological indices, in the form of event-related potentials (ERPs) recorded at 32 sites, following exposure to emotionally positive or negative music excerpts. We observed smaller N2 amplitudes in response to facial expressions in the amusia group than in the control group, suggesting that amusics were less affected by the musical stimuli. The late-positive component (LPC) in amusics was similar to that in controls. Our results suggest that the neurocognitive deficit characteristic of congenital amusia is fundamentally an impairment in musical information processing rather than an impairment in emotional processing. (C) 2017 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).</p

    Impaired face recognition is associated with abnormal gray matter volume in the posterior cingulate cortex in congenital amusia

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    Congenital amusia is as a neurodevelopment disorder primarily defined by impairment in pitch discrimination and pitch memory. Interestingly, it has been reported that individuals with congenital amusia also exhibit deficits in face recognition (prosopagnosia). One explanation of such comorbidity is that the neural substrates of pitch recognition and face recognition may be similar. To test this hypothesis, face recognition ability was assessed using the Cambridge Face Memory Test (CFMT) and gray matter volume was determined through voxelbased morphometry (VBM) among participants with and without congenital amusia. As expected, participants with amusia performed worse on the CFMT test and showed reduced gray matter volume (GMV) in the middle temporal gyrus (MTG), the superior temporal gyrus (STG), and the posterior cingulate cortex (PCC) in the right hemisphere, when compared with matched controls. Furthermore, correlation analyses demonstrated that the CFMT score was positively related to MTG, STG, and PCC GMV in all participants, while separate analyses of each group found a positive correlation of CFMT score and PCC GMV in amusics. These findings suggest that face recognition is associated with a widely distributed microstructural network in the human brain and the PCC plays an important role in both pitch recognition and face recognition in amusics. In addition, neurodevelopmental disorders such as congenital amusia and prosopagnosia may share a common neural substrate

    Zn and P Alloying Effect in Sub-Rapidly Solidified LaFe<sub>11.6</sub>Si<sub>1.4</sub> Magnetocaloric Plates

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    The occupation mechanism and magnetic transition behavior of trace Zn and P alloying in the sub-rapidly solidified LaFe11.6Si1.4 magnetocaloric plates were investigated. The LaFe11.6Si1.4, LaFe11.6Si1.4Zn0.03, and LaFe11.6Si1.4P0.03 plates were fabricated using the centrifugal casting method in the present work. Experimental results showed that both Zn and P elements were distributed in the La5Si3 and LaFeSi phases during sub-rapid solidification. After annealed at 1373 K for 72 h, the LaFe11.6Si1.4 plate underwent a second-order magnetic transition, while both the LaFe11.6Si1.4Zn0.03 and LaFe11.6Si1.4P0.03 plates underwent a first-order transition. In combination with X-ray diffraction results, it was proposed that both Zn and P atoms prefer to enter the 96i site substituting for FeII/Si atoms according to the density-functional reconstruction of crystallographic structure. The Zn addition led to a slight decrease in magnetic entropy change from 7.0 to 5.9 J/(kg&#8901;K), while the P addition strikingly enhanced this property to 31.4 J/(kg&#8901;K) under a magnetic field change of 3 T. The effective refrigeration capacity of the annealed LaFe11.6Si1.4P0.03 plate reached 189.9 J/kg

    Oxygen-deficient MoO₃₋ₓ evoked synergistic photo-thermal catalytic CO₂ reduction over g-C₃N₄

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    Developing inexpensive co-catalysts for photo-thermal synergistic catalysis by artificially inducing active sites on non-noble metal compounds has drawn much attention recently. In this work, oxygen-deficient molybdenum oxide (MoO3−x) was in situ photodeposited on the surface of graphite-like carbon nitride (g-C3N4) to tremendously improve its photocatalytic activity for CO2 conversion. A series of characterization analyses divulged that the MoO3−x not only promoted the separation of photo-generated charge carriers, but also served as the active sites for the adsorption and activation of CO2 molecules. More importantly, the oxygen-vacancy defect sites of MoO3−x can trigger localized surface plasmon resonance (LSPR) that enables effective harnessing of near-infrared (NIR) photons, promoting photo-thermal synergistic catalytic conversion of CO2 into value-added fuels through full solar spectrum harnessing.This work was financially supported by the Science and Technology Department of Henan Province (No. 222102320238), the Education Department of Henan Province (No. 21A150041), the National Natural Science Foundation of China (No. 51872147), the Natural Science Foundation of Henan Province (No. 202300410298), the Science Foundation of Nanyang Normal University (No. 2018ZX006, 2022PY018, and 2022ZX003), the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 52202306), the Shenzhen Key Laboratory of Eco-materials and Renewable Energy (ZDSYS20200922160400001), the Shenzhen Natural Science Foundation (GXWD20201231105722002-20200824163747001) and the Innovation and Entrepreneurship Training Program for College Students in Henan Province (No. 202110481006 and 202210481001)

    Effect of casting temperature on the solidification process and (micro)structure of Zr-based metallic glasses

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    Bulk metallic glasses (BMGs) bear versatile advantages compared to traditional crystalline metallic materials. However, preparation of large size BMG components remains a great challenge due to the lack of understanding the casting dynamics of BMGs. The present work investigates the dynamics of the solidification process during casting of a Zr41.2Ti13.8Cu12.5Ni10Be22.5 BMG by measuring the time-dependent temperature evolution and constructing distance–time curves showing the progress of solidification. The experimentally probed temperature evolution proves that a higher casting temperature causes a lower cooling rate and induces more pronounced nanocrystal phase formation in the final BMG casting. Thus, optimization of the casting temperature is crucial for casting BMG components. The solidification coefficient K of the studied Zr-based BMG in copper mold was determined. The solidification time can be calculated with model: τ=M2K2. The solidification of the Zr-based BMG occurs in a narrow transition layer region following a “layer-by-layer” solidification mode. This feature is vital for designing the casting process appropriately to avoid the formation of casting defects in BMG components. The present work sheds new light on the solidification mechanism of bulk glass-forming liquids and underlines the importance of optimizing the technology and processing conditions for fabrication of BMG components with practical applications

    Erratum to: Performance evaluation of operational atmospheric correction algorithms over the East China Seas (Chinese Journal of Oceanology and Limnology, (2017), 35, 1, (1-22), 10.1007/s00343-016-5170-6)

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    Unfortunately for all articles of Vol. 35 No. 1 the future journal title “Journal of Oceanology and Limnology” was used instead of the current journal title “Chinese Journal of Oceanology and Limnology”. All articles in the issue are affected. Please make sure to cite the articles with the following Vol. and No. info: Chinese Journal of Oceanology and Limnology, Vol. 35 No. 1, [page range]

    Erratum to : Performance evaluation of operational atmospheric correction algorithms over the East China Seas (Chinese Journal of Oceanology and Limnology, (2017), 35, 1, (1-22), 10.1007/s00343-016-5170-6)

    No full text
    Unfortunately for all articles of Vol. 35 No. 1 the future journal title “Journal of Oceanology and Limnology” was used instead of the current journal title “Chinese Journal of Oceanology and Limnology”. All articles in the issue are aff ected. Please make sure to cite the articles with the following Vol. and No. info: Chinese Journal of Oceanology and Limnology, Vol. 35 No. 1, [page range]
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