242 research outputs found

    Qualitative design and implementation of human-robot spatial interactions

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    Despite the large number of navigation algorithms available for mobile robots, in many social contexts they often exhibit inopportune motion behaviours in proximity of people, often with very "unnatural" movements due to the execution of segmented trajectories or the sudden activation of safety mechanisms (e.g., for obstacle avoidance). We argue that the reason of the problem is not only the difficulty of modelling human behaviours and generating opportune robot control policies, but also the way human-robot spatial interactions are represented and implemented. In this paper we propose a new methodology based on a qualitative representation of spatial interactions, which is both flexible and compact, adopting the well-defined and coherent formalization of Qualitative Trajectory Calculus (QTC). We show the potential of a QTC-based approach to abstract and design complex robot behaviours, where the desired robot's behaviour is represented together with its actual performance in one coherent approach, focusing on spatial interactions rather than pure navigation problems

    Irradiation-energy Dependence on the Spectral Changes of Hydrous C-Type Asteroids Based on 4kev and 20kev He Exposure Experiments of Murchison Cm Chondrite

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    C-type asteroid 162173 Ryugu was observed by remote sensing apparatus onboard Hayabusa2 spacecraft and found to be very dark object whose reflectance is (1.60 0.15) % at 0.55m and showed a small 2.7m absorption band indicative of phyllosilicates. The optical navigation camera detected color variations of Ryugus surface in the wavelength range from 0.4 to 0.95m: Bluer spectra are ob-served at both poles and on the equatorial ridge, both of which are topographic highs and thus may be fresh material exposed by gradual erosion. On the other hand, many locations at middle-latitude areas exhibit redder and darker colors. Similar color variations are also detected in the near-infrared wavelength range. These observations suggest that a surface-correlated process is responsible for the color variation, most prob-ably from blue to red, but the mechanism for the change is not yet identified. Space weathering is one possible mechanism responsible for the color variation, but the spectral changes of C-type asteroids from space weathering are far from being fully understood. Past experimental studies using hydrous carbonaceous chondrites such as Murchison and Tagish Lake show that He exposure (simulating solar wind irradiation) changes spectra to bluer and brighter. Recently our He exposure experiments indicate that spectral changes depend on physical properties such as porosity of exposed material. In this study, we per-formed further He exposure experiments using Murchison CM chondrite in order to understand energy dependence on the spectral changes. We found that He energy is a critical parameter, as well as physical properties of the samples, that affects spectral changes of space weathering of hydrated C-type asteroids

    RESULTS OF IDENTIFICATION OF INFECTIOUS AGENTS OF INFLUENZA AND OTHER ACUTE RESPIRATORY INFECTIONS WITH THE METHOD OF RT-LAMP

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    Currently, the detection and identification of viruses that cause respiratory and influenza-like illness (ILI) is one of the main tasks of  public healthcare. In 2016-2017, nasopharyngeal swabs were  collected from 200 sick children with ILI aged 0 to 5 years. Detection  of pathogens in ILI patients was carried out by RT-LAMP  amplification method. In 43 % of patients ILI viruses were detected.  Among all confirmed cases of viral infection, a respiratory-syncytial  virus was detected in 49 %, rhinoviruses in 16 %, coronaviruses in 9 %,  parainfluenza viruses in 6 %, and human metapneumoviruses in 2 % of  samples. Influenza A viruses were found in 6 % of infected specimens.  The results obtained demonstrate the effectiveness of using RT-LAMP amplification in differential laboratory diagnostics of the ILI of viral etiology

    Biharmonic PNMC Submanifolds in Spheres

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    We obtain several rigidity results for biharmonic submanifolds in Sn\mathbb{S}^{n} with parallel normalized mean curvature vector field. We classify biharmonic submanifolds in Sn\mathbb{S}^{n} with parallel normalized mean curvature vector field and with at most two distinct principal curvatures. In particular, we determine all biharmonic surfaces with parallel normalized mean curvature vector field in Sn\mathbb{S}^n. Then we investigate, for (not necessarily compact) proper biharmonic submanifolds in Sn\mathbb{S}^n, their type in the sense of B-Y. Chen. We prove: (i) a proper biharmonic submanifold in Sn\mathbb{S}^n is of 1-type or 2-type if and only if it has constant mean curvature {\mcf}=1 or {\mcf}\in(0,1), respectively; (ii) there are no proper biharmonic 3-type submanifolds with parallel normalized mean curvature vector field in Sn\mathbb{S}^n.Comment: 17 page

    Mechanical guidance of self-condensation patterns of differentiating progeny

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    Spatially controlled self-organization represents a major challenge for organoid engineering. We have developed a mechanically patterned hydrogel for controlling self-condensation process to generate multi-cellular organoids. We first found that local stiffening with intrinsic mechanical gradient (IG > 0.008) induced single condensates of mesenchymal myoblasts, whereas the local softening led to stochastic aggregation. Besides, we revealed the cellular mechanism of two-step self-condensation: (1) cellular adhesion and migration at the mechanical boundary and (2) cell-cell contraction driven by intercellular actin-myosin networks. Finally, human pluripotent stem cell-derived hepatic progenitors with mesenchymal/endothelial cells (i.e., liver bud organoids) experienced collective migration toward locally stiffened regions generating condensates of the concave to spherical shapes. The underlying mechanism can be explained by force competition of cell-cell and cell-hydrogel biomechanical interactions between stiff and soft regions. These insights will facilitate the rational design of culture substrates inducing symmetry breaking in self-condensation of differentiating progeny toward future organoid engineering.Matsuzaki T., Shimokawa Y., Koike H., et al. Mechanical guidance of self-condensation patterns of differentiating progeny. iScience 25, 105109 (2022); https://doi.org/10.1016/j.isci.2022.105109

    Interstitial cystitis: a rare manifestation of primary Sjögren’s syndrome, successfully treated with low dose cyclosporine

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    Chronic interstitial cystitis (IC), mostly affecting middle-aged women, is a very rare manifestation of primary Sjögren’s syndrome (pSS). Hereby, we report a 42-year-old woman with pSS, presenting with dysuria, urinary frequency, and suprapubic pain. She was diagnosed to have chronic IC, based upon the cystoscopic biopsy finding of chronic inflammation in the bladder wall. Systemic corticosteroid and azathioprine treatments together with local intravesical therapies were not effective. Therefore, cyclosporine (CSA) therapy was initiated. Initial low dose of CSA (1.5 mg/kg/d) improved the symptoms of the patient, with no requirement for dose increment. After 4 months of therapy, control cystoscopic biopsy showed that bladder inflammation regressed and IC improved. This case suggests that even low doses of CSA may be beneficial for treating chronic IC associated with pSS syndrome

    Preparation of mechanically patterned hydrogels for controlling the self-condensation of cells

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    Synthetic protocols providing mechanical patterns to culture substrate are essential to control the self-condensation of cells for organoid engineering. Here, we present a protocol for preparing hydrogels with mechanical patterns. We describe steps for hydrogel synthesis, mechanical evaluation of the substrate, and time-lapse imaging of cell self-organization. This protocol will facilitate the rational design of culture substrates with mechanical patterns for the engineering of various functional organoids. For complete details on the use and execution of this protocol, please refer to Takebe et al. (2015) and Matsuzaki et al. (2014, 2022).Matsuzaki T., Kawano Y., Horikiri M., et al. Preparation of mechanically patterned hydrogels for controlling the self-condensation of cells. STAR Protocols 4, 102471 (2023); https://doi.org/10.1016/j.xpro.2023.102471

    Diamond Blackfan anemia is mediated by hyperactive Nemo-like kinase

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    Diamond Blackfan Anemia (DBA) is a congenital bone marrow failure syndrome associated with ribosomal gene mutations that lead to ribosomal insufficiency. DBA is characterized by anemia, congenital anomalies, and cancer predisposition. Treatment for DBA is associated with significant morbidity. Here, we report the identification of Nemo-like kinase (NLK) as a potential target for DBA therapy. To identify new DBA targets, we screen for small molecules that increase erythroid expansion in mouse models of DBA. This screen identified a compound that inhibits NLK. Chemical and genetic inhibition of NLK increases erythroid expansion in mouse and human progenitors, including bone marrow cells from DBA patients. In DBA models and patient samples, aberrant NLK activation is initiated at the Megakaryocyte/Erythroid Progenitor (MEP) stage of differentiation and is not observed in non-erythroid hematopoietic lineages or healthy erythroblasts. We propose that NLK mediates aberrant erythropoiesis in DBA and is a potential target for therapy
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