3,394 research outputs found

    In the Wild Human Pose Estimation Using Explicit 2D Features and Intermediate 3D Representations

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    Convolutional Neural Network based approaches for monocular 3D human pose estimation usually require a large amount of training images with 3D pose annotations. While it is feasible to provide 2D joint annotations for large corpora of in-the-wild images with humans, providing accurate 3D annotations to such in-the-wild corpora is hardly feasible in practice. Most existing 3D labelled data sets are either synthetically created or feature in-studio images. 3D pose estimation algorithms trained on such data often have limited ability to generalize to real world scene diversity. We therefore propose a new deep learning based method for monocular 3D human pose estimation that shows high accuracy and generalizes better to in-the-wild scenes. It has a network architecture that comprises a new disentangled hidden space encoding of explicit 2D and 3D features, and uses supervision by a new learned projection model from predicted 3D pose. Our algorithm can be jointly trained on image data with 3D labels and image data with only 2D labels. It achieves state-of-the-art accuracy on challenging in-the-wild data

    Field induced density wave in the heavy fermion compound CeRhIn5

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    Metals containing Ce often show strong electron correlations due to the proximity of the 4f state to the Fermi energy, leading to strong coupling with the conduction electrons. This coupling typically induces a variety of competing ground states, including heavy-fermion metals, magnetism and unconventional superconductivity. The d-wave superconductivity in CeTMIn5 (TM=Co, Rh, Ir) has attracted significant interest due to its qualitative similarity to the cuprate high-Tc superconductors. Here, we show evidence for a field induced phase-transition to a state akin to a density-wave (DW) in the heavy fermion CeRhIn5, existing in proximity to its unconventional superconductivity. The DW state is signaled by a hysteretic anomaly in the in-plane resistivity accompanied by the appearance of non-linear electrical transport at high magnetic fields (>27T), which are the distinctive characteristics of density-wave states. The unusually large hysteresis enables us to directly investigate the Fermi surface of a supercooled electronic system and to clearly associate a Fermi surface reconstruction with the transition. Key to our observation is the fabrication of single crystal microstructures, which are found to be highly sensitive to "subtle" phase transitions involving only small portions of the Fermi surface. Such subtle order might be a common feature among correlated electron systems, and its clear observation adds a new perspective on the similarly subtle CDW state in the cuprates.Comment: Accepted in Nature Communication

    XNect: Real-time Multi-person 3D Human Pose Estimation with a Single RGB Camera

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    We present a real-time approach for multi-person 3D motion capture at over 30 fps using a single RGB camera. It operates in generic scenes and is robust to difficult occlusions both by other people and objects. Our method operates in subsequent stages. The first stage is a convolutional neural network (CNN) that estimates 2D and 3D pose features along with identity assignments for all visible joints of all individuals. We contribute a new architecture for this CNN, called SelecSLS Net, that uses novel selective long and short range skip connections to improve the information flow allowing for a drastically faster network without compromising accuracy. In the second stage, a fully-connected neural network turns the possibly partial (on account of occlusion) 2D pose and 3D pose features for each subject into a complete 3D pose estimate per individual. The third stage applies space-time skeletal model fitting to the predicted 2D and 3D pose per subject to further reconcile the 2D and 3D pose, and enforce temporal coherence. Our method returns the full skeletal pose in joint angles for each subject. This is a further key distinction from previous work that neither extracted global body positions nor joint angle results of a coherent skeleton in real time for multi-person scenes. The proposed system runs on consumer hardware at a previously unseen speed of more than 30 fps given 512x320 images as input while achieving state-of-the-art accuracy, which we will demonstrate on a range of challenging real-world scenes

    The time-dependent expression of keratins 5 and 13 during the reepithelialization of human skin wounds

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    The time-dependent reepithelialization of 55 human surgical skin wounds with a wound age between 8h and more than 2 months was investigated by the immunohistochemical localization of cytokeratins 5 and 13. A complete, rebuilt epidermal layer over the wound area was first detectable in a 5-day-old wound, while all wounds of more than 18 days duration contained a completely reepithelialized wound area. Between 5 and 18 days the basal layer of keratinocytes showed — in contrast to normal skin — only some cells positive for cytokeratin 5. In some, but not all lesions with a wound age of 13 days or more, a basal cell layer completely staining for cytokeratin 5 was demonstrable. This staining pattern was found in all skin wounds with a wound age of more than 23 days. The immunohistochemical detection of cytokeratin 13 which can be observed regularly in non-cornifying squamous epithelia provides no information for the time-estimation of human skin wounds, since no significant temporary expression of this polypeptide seems to occur during the healing of human skin wounds

    High-energy overtone spectroscopy of some deuterated methanes

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    High-energy overtone photoacoustic spectroscopy of gas phase CHD3 (ΔνCH=5,6, and 7), CH2D2, CH3D, and CH4 (ΔνCH=6) is reported. The overtone and combination bands of CHD3 display partially resolved rotational structure with laser limited linewidths (~0.5 cm^−1). A combination sum analysis is used to generate excited state rotational constants B'. We present an analysis of the Fermi resonances of CHD3 which indicates strong interactions of the CH stretch with degenerate bending modes. The relative intensities of the Fermi interacting states are in agreement with those calculated from an analysis based on frequency shifts and a two or three level model. However, the rotational B' constants are not explained by such simple models indicating further interactions with states as yet unobserved. An upper limit of 10 cm^−1 is estimated for the splitting of the |6,0>± local mode states for CH2D2, giving support to a description based on the local mode picture. For CH3D and CH4 the spectra are apparently congested by overlapping overtone and combination bands and perhaps other mechanisms not identified in this work. Generally, our results emphasize the importance of the interactions of CH stretching with CH bending motions

    Electronic in-plane symmetry breaking at field-tuned quantum criticality in CeRhIn5

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    Electronic nematics are exotic states of matter where electronic interactions break a rotational symmetry of the underlying lattice, in analogy to the directional alignment without translational order in nematic liquid crystals. Intriguingly such phases appear in the copper- and iron-based superconductors, and their role in establishing high-temperature superconductivity remains an open question. Nematicity may take an active part, cooperating or competing with superconductivity, or may appear accidentally in such systems. Here we present experimental evidence for a phase of nematic character in the heavy fermion superconductor CeRhIn5. We observe a field-induced breaking of the electronic tetragonal symmetry of in the vicinity of an antiferromagnetic (AFM) quantum phase transition at Hc~50T. This phase appears in out-of-plane fields of H*~28T and is characterized by substantial in-plane resistivity anisotropy. The anisotropy can be aligned by a small in-plane field component, with no apparent connection to the underlying crystal structure. Furthermore no anomalies are observed in the magnetic torque, suggesting the absence of metamagnetic transitions in this field range. These observations are indicative of an electronic nematic character of the high field state in CeRhIn5. The appearance of nematic behavior in a phenotypical heavy fermion superconductor highlights the interrelation of nematicity and unconventional superconductivity, suggesting nematicity to be a commonality in such materials

    {Rearrangement of the antiferromagnetic ordering at high magnetic fields in SmFeAsO and SmFeAsO0.9_{0.9}F0.1_{0.1} single crystals

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    The low-temperature antiferromagnetic state of the Sm-ions in both nonsuperconducting SmFeAsO and superconducting SmFeAsO0.9_{0.9}F0.1_{0.1} single crystals was studied by magnetic torque, magnetization, and magnetoresistance measurements in magnetic fields up to 60~T and temperatures down to 0.6~K. We uncover in both compounds a distinct rearrangement of the antiferromagnetically ordered Sm-moments near 35−4035-40~T. This is seen in both, static and pulsed magnetic fields, as a sharp change in the sign of the magnetic torque, which is sensitive to the magnetic anisotropy and hence to the magnetic moment in the abab-plane, ({\it i.e.} the FeAs-layers), and as a jump in the magnetization for magnetic fields perpendicular to the conducting planes. This rearrangement of magnetic ordering in 35−4035-40~T is essentially temperature independent and points towards a canted or a partially polarized magnetic state in high magnetic fields. However, the observed value for the saturation moment above this rearrangement, suggests that the complete suppression of the antiferromagnetism related to the Sm-moments would require fields in excess of 60~T. Such a large field value is particularly remarkable when compared to the relatively small N\'{e}el temperature TN≃5T_{\rm N}\simeq5~K, suggesting very anisotropic magnetic exchange couplings. At the transition, magnetoresistivity measurements show a crossover from positive to negative field-dependence, indicating that the charge carriers in the FeAs planes are sensitive to the magnetic configuration of the rare-earth elements. This is indicates a finite magnetic/electronic coupling between the SmO and the FeAs layers which are likely to mediate the exchange interactions leading to the long range antiferromagnetic order of the Sm ions.Comment: 10 pages, 7 figures, accepted in Phys. Rev.

    Enzymatic detoxification of the fumonisin mycotoxins during dry milling of maize

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    Fumonisin esterase FumD (EC 3.1.1.87), FUMzyme® (BIOMIN, Austria), effectively detoxifies fumonisin B mycotoxins (FB) by hydrolysis and removal of the tricarballylic acid groups. The current study evaluated FumD detoxification of total FB (FBT) in commercial maize utilising an experimental dry milling plant by introducing the enzyme during the kernel conditioning stage. Total FB and the hydrolysed product of FB1, HFB1, in maize and milling products were determined by LC-MS/MS. During maize conditioning of 4 h 10 min substantial FB1 hydrolysis was achieved between 1 and 4 U FumD/100 g maize. Complete conversion into HFB1 was delayed and only achieved at the highest enzyme concentration (32 U/100 g maize) reaching a 1:1 M conversion ratio. Dry milling of maize containing 3.29 ± 0.20 μmole FBT/kg (2354 ± 140 μg/kg) in the absence of FumD, resulted in a 2.5-fold increase in the FBT concentration in total hominy feed (8.34 ± 0.22 μmol/kg) (5979 ± 158 μg/kg) compared to the levels that prevail in Super (0.52 ± 0.07 μmol/kg) (347 ± 48 μg/kg) and Special (1.70 ± 0.01 μmol/kg) (1213 ± 8 μg/kg) maize meal, and Semolina (1.07 ± 0.14 μmol/kg) (765 ± 100 μg/kg) milling products. Introduction of FumD (40 U/kg) mainly impacted the total hominy feed product (germ + hominy milling fractions), constituting up to 30% of the reconstituted whole maize
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