80 research outputs found

    Learning Compliant Stiffness by Impedance Control-Aware Task Segmentation and Multi-objective Bayesian Optimization with Priors

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    Rather than traditional position control, impedance control is preferred to ensure the safe operation of industrial robots programmed from demonstrations. However, variable stiffness learning studies have focused on task performance rather than safety (or compliance). Thus, this paper proposes a novel stiffness learning method to satisfy both task performance and compliance requirements. The proposed method optimizes the task and compliance objectives (T/C objectives) simultaneously via multi-objective Bayesian optimization. We define the stiffness search space by segmenting a demonstration into task phases, each with constant responsible stiffness. The segmentation is performed by identifying impedance control-aware switching linear dynamics (IC-SLD) from the demonstration. We also utilize the stiffness obtained by proposed IC-SLD as priors for efficient optimization. Experiments on simulated tasks and a real robot demonstrate that IC-SLD-based segmentation and the use of priors improve the optimization efficiency compared to existing baseline methods.Comment: Accepted to IROS202

    Endometrial Cancer Arising in Adenomyosis That Could Not Be Diagnosed by Endometrial Biopsy: A Case Report

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    Uterine adenomyosis is an estrogen-dependent tumor and one of the most common benign diseases in sexually mature women. The frequency of endometrial cancer associated with adenomyosis has been reported to be 18%–66%. On the other hand, endometrial cancer arising in adenomyosis (EC-AIA) is extremely rare. EC-AIA is now considered a different entity from and has a worse prognosis than endometrial cancer with adenomyosis (EC-A). In the present study, we report a case of endometrial cancer with adenomyosis in which endometrial biopsy failed to provide a definitive diagnosis. A 63-year-old female patient presented with endometrial thickening. Endometrial cytology was positive, and magnetic resonance imaging (MRI) showed small lesions suggestive of endometrial cancer with shallow invasion and adenomyosis. However, an endometrial biopsy showed only metaplasia, and careful follow-up was initiated. Subsequent endometrial cytology showed enlarged and round nuclei, uniform chromatin distribution, no thickening of nuclear margins, and abundant cytoplasm appearing in a sheet-like arrangement, suggesting atypical cells of endometrial glands with metaplasia. Three suspicious positive results and one positive result were observed, but repeated biopsies did not lead to the diagnosis of malignancy. The patient underwent diagnostic hysterectomy 19 months after the initial visit. The postoperative histopathological diagnosis was stage IA endometrial cancer (endometrioid carcinoma G1). This case of endometrial cancer associated with adenomyosis was difficult to diagnose. Our findings demonstrate that EC-AIA should be considered even if no lesions were detected by endometrial biopsy

    Doubly-charged scalar bosons from the doublet

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    We consider the extended Higgs models, in which one of the isospin doublet scalar fields carries the hypercharge Y=3/2. Such a doublet field Φ3/2\Phi_{3/2} is composed of a doubly charged scalar boson as well as a singly charged one. We first discuss a simple model with Φ3/2\Phi_{3/2} (Model I), and study its collider phenomenology at the LHC. We then consider a new model for radiatively generating neutrino masses with a dark matter candidate (Model II), in which Φ3/2\Phi_{3/2} and an extra Y=1/2 doublet as well as vector-like singlet fermions carry the odd quantum number for an unbroken discrete Z2Z_2 symmetry. We also discuss the neutrino mass model (Model III), in which the exact Z2Z_2 parity in Model II is softly broken. It is found that the doubly charged scalar bosons in these models show different phenomenological aspects from those which appear in models with a Y=2 isospin singlet field or a Y=1 triplet one. They could be clearly distinguished at the LHC.Comment: 5 pages, 4 figures, Fig. 2 replaced, references added, typo correcte

    Lymph Drainage during Wound Healing in a Hindlimb Lymphedema Mouse Model

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    Background: Although lymphedematous skin exhibits delayed wound healing, little is known about lymph drainage during wound healing. We investigated the wound healing process in the presence of lymphatic dysfunction. Methods and Results: The right inguinal lymph nodes (iLNs) and the surrounding tissue were excised in each mouse (the operation side), and a sham operation was performed in the left hindlimb (the control side). The next day, full-thickness wounds were made on both hindlimbs. The right hindlimb exhibited acute edema until day 3; however, it started to improve after day 4, and the wound area and epithelialization ratio were similar on both sides. Indocyanine green (ICG) was injected into both hindlimbs to observe lymph flow. On the operation side, ICG leaked out of the surgical site or remained at the injection site until day 2. Some lymph flow toward the existing lymph vessels was seen on day 3, and on day 10, lymph flow toward the axial LNs was detected on the operation side in all mice. On the operation side, the number of dermal lymph vessels was significantly increased on days 3 and 15. The dermal lymph vessel area of the peripheral wound was significantly smaller on the operation side. Conclusions: In a hindlimb lymphedema mouse model, lymph transiently accumulated in subcutaneous tissue, and then was gradually absorbed by the existing lymph vessels. The increase in the number of lymph vessels contributes to lymph drainage during wound healing. Acute lymphedema because of transient lymphatic dysfunction has little effect on wound healing. © Copyright 2017, Mary Ann Liebert, Inc. 2017.Embargo Period 12 month

    Renormalization of the Higgs sector in the triplet model

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    We study radiative corrections to the mass spectrum and the triple Higgs boson coupling in the model with an additional Y=1 triplet field. In this model, the vacuum expectation value for the triplet field is strongly constrained from the electroweak precision data, under which characteristic mass spectrum appear at the tree level; i.e., mH++2mH+2mH+2mA2m_{H^{++}}^2-m_{H^+}^2\simeq m_{H^+}^2-m_A^2 and mA2mH2m_A^2\simeq m_H^2, where the CP-even (HH), the CP-odd (AA) and the doubly-charged (H±±H^{\pm\pm}) as well as the singly-charged (H±H^\pm) Higgs bosons are the triplet-like. We evaluate how the tree-level formulae are modified at the one-loop level. The hhhhhh coupling for the standard model-like Higgs boson (hh) is also calculated at the one-loop level. One-loop corrections to these quantities can be large enough for identification of the model by future precision data at the LHC or the International Linear Collider.Comment: Published version in Physics Letters

    A porcine placental extract prevents steatohepatitis by suppressing activation of macrophages and stellate cells in mice

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    金沢大学医薬保健研究域医学系Nonalcoholic fatty liver disease (NAFLD) is caused by ectopic fat accumulation in the liver. NAFLD is associated with hepatic inflammation and oxidative stress, resulting in nonalcoholic steatohepatitis (NASH) with advanced fibrosis. Placental extracts have been used to treat various chronic diseases due to their antioxidative effect. However, the effects of the extracts on the development of NASH have yet to be elucidated. Here, we demonstrated that supplementation with an oral porcine placental extract (PPE) attenuated lipid accumulation and peroxidation, insulin resistance, inflammatory and stress signaling, and fibrogenesis in the liver of NASH model mice fed a high-cholesterol and high-fat diet. The PPE reduced the number of M1-like liver macrophages, but increased the number of anti-inflammatory M2-like macrophages, resulting in a predominance of M2 over M1 macrophage populations in the liver of NASH mice. Accordingly, the PPE suppressed lipopolysaccharide-induced M1 polarization in isolated murine peritoneal macrophages, whereas it facilitated interleukin 4-induced M2 polarization. Furthermore, the PPE reduced the hepatic stellate cell (HSC) activation associated with the attenuated transforming growth factor-β/Smad3 signaling, both in the liver of NASH mice and in RI-T cells, a HSC line. The PPE may be a potential approach to prevent NASH by limiting lipid peroxidation, promoting M2 macrophage polarization, and attenuating HSC activation. © Xu et al
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