81 research outputs found

    J-holomorphic curves in a nef class

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    Taubes established fundamental properties of J−J-holomorphic subvarieties in dimension 4 in \cite{T1}. In this paper, we further investigate properties of reducible J−J-holomorphic subvarieties. We offer an upper bound of the total genus of a subvariety when the class of the subvariety is J−J-nef. For a spherical class, it has particularly strong consequences. It is shown that, for any tamed JJ, each irreducible component is a smooth rational curve. We also completely classify configurations of maximal dimension. To prove these results we treat subvarieties as weighted graphs and introduce several combinatorial moves.Comment: 30 pages. v2 Section 4.3 revised; minor changes elsewhere. v3 mistakes correcte

    Local breaking of four-fold rotational symmetry by short-range magnetic order in heavily overdoped Ba(Fe1−x_{1-x}Cux_{x})2_{2}As2_{2}

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    We investigate Cu-doped Ba(Fe1−x_{1-x}Cux_x)2_2As2_2 with transport, magnetic susceptibility, and elastic neutron scattering measurements. In the heavily Cu-doped regime where long-range stripe-type antiferromagnetic order in BaFe2_2As2_2 is suppressed, Ba(Fe1−x_{1-x}Cux_x)2_2As2_2 (0.145 ≤x≤\leq x \leq 0.553) samples exhibit spin-glass-like behavior in magnetic susceptibility and insulating-like temperature dependence in electrical transport. Using elastic neutron scattering, we find stripe-type short-range magnetic order in the spin-glass region identified by susceptibility measurements. The persistence of short-range magnetic order over a large doping range in Ba(Fe1−x_{1-x}Cux_x)2_2As2_2 likely arises from local arrangements of Fe and Cu that favor magnetic order, with Cu acting as vacancies relieving magnetic frustration and degeneracy. These results indicate locally broken four-fold rotational symmetry, suggesting that stripe-type magnetism is ubiquitous in iron pnictides.Comment: accepted by Physical Review B Rapid Communication

    Influence of Lactobacillus plantarum P-8 on Fermented Milk Flavor and Storage Stability

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    Previously, we demonstrated that the flavor of milk fermented with Lactobacillus delbrueckii subsp. bulgaricus (IMAU20401) and Streptococcus thermophilus (IMAU40133) at a 1:1000 ratio was superior to that of other ratios of the two strains. In this study, Lactobacillus plantarum P-8 was used as the probiotic bacterium. Six ratios (1:1, 1:5, 1:10, 1:50, 1:100, and 1:1000) of L. plantarum P-8 to yogurt starter were evaluated. A total of 66 volatile compounds including aldehydes, ketones, acids, alcohols, esters, alcohols, and aromatic compounds were identified in milk fermented with the six different L. plantarum P-8 to yogurt starter ratios at 0 d of storage. In particular, key flavor compounds, such as 3-methylbutanal, hexanal, (E)-2-octenal, nonanal, 2-heptanone, 2-nonanone, and acetoin, were identified in the 1:100 ratio treatment. Furthermore, the viable cell count, pH, titratable acidity, viscosity, and syneresis of the milk samples were analyzed during fermentation over 14 d of storage at 4°C. The results indicated that milk can be fermented with L. plantarum P-8 in combination with S. thermophilus and L. delbrueckii subsp. bulgaricus, and the physicochemical characteristics of the milk were not affected by the probiotic bacteria

    A multispeaker dataset of raw and reconstructed speech production real-time MRI video and 3D volumetric images

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    Real-time magnetic resonance imaging (RT-MRI) of human speech production is enabling significant advances in speech science, linguistics, bio-inspired speech technology development, and clinical applications. Easy access to RT-MRI is however limited, and comprehensive datasets with broad access are needed to catalyze research across numerous domains. The imaging of the rapidly moving articulators and dynamic airway shaping during speech demands high spatio-temporal resolution and robust reconstruction methods. Further, while reconstructed images have been published, to-date there is no open dataset providing raw multi-coil RT-MRI data from an optimized speech production experimental setup. Such datasets could enable new and improved methods for dynamic image reconstruction, artifact correction, feature extraction, and direct extraction of linguistically-relevant biomarkers. The present dataset offers a unique corpus of 2D sagittal-view RT-MRI videos along with synchronized audio for 75 subjects performing linguistically motivated speech tasks, alongside the corresponding first-ever public domain raw RT-MRI data. The dataset also includes 3D volumetric vocal tract MRI during sustained speech sounds and high-resolution static anatomical T2-weighted upper airway MRI for each subject.Comment: 27 pages, 6 figures, 5 tables, submitted to Nature Scientific Dat
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