100 research outputs found
Light neutralino in the MSSM: An update with the latest LHC results
We discuss the scenario of light neutralino dark matter in the minimal
supersymmetric standard model, which is motivated by the results of some of the
direct detection experiments --- DAMA, CoGENT, and CRESST. We update our
previous analysis with the latest results of the LHC. We show that new LHC
constraints disfavour the parameter region that can reproduce the results of
DAMA and CoGENT.Comment: 4 pages, 4 figures, to appear in the conference proceedings of TAUP
2011, Munich Germany, 5-9 September 201
Using the Waseda Bioinstrumentation System WB-1R to analyze Surgeon’s performance during laparoscopy - towards the development of a global performance index -
Minimally invasive surgery (MIS) has become very common in recent years, thanks to the many advantages it provides for patients. Since it is difficult for surgeons to learn and master this technique, several training methods and metrics have been proposed, both to improve the surgeon's abilities and also to assess his/her skills. This paper presents the use of the WB-1R (Waseda Bioinstrumentation system no.1. Refined), which was developed at Waseda University, Tokyo, to investigate and analyze a surgeon's movements and performance. Specifically, the system can measure the movements of the head, the arms, and the hands, as well as several physiological parameters. In this paper we present our experiment to evaluate a surgeon's ability to handle surgical instruments and his/her depth perception using a laparoscopic view. Our preliminary analysis of a subset of the acquired data (i.e. comfort of the subjects; the amount of time it took o complete each exercise; and respiration) clearly shows that the expert surgeon and the group of medical students perform very differently. Therefore, WB-1R (or, better, a newer version tailored specifically for use in the operating room) could provide important additional information to help assess the experience and performance of surgeons, thus leading to the development of a Global Performance Index for surgeons during MIS. These analyses and modeling, moreover, are an important step towards the automatization and the robotic assistance of the surgical gesture
Is hugging a robot weird? Investigating the influence of robot appearance on users' perception of hugging
Humanoid robots are expected to be able to communicate with humans using physical interaction, including hug, which is a common gesture of affection. In order to achieve that, their physical embodiment has to be carefully planned, as a user-friendly design will facilitate interaction and minimise repulsion. In this paper, we investigate the effect of manipulating the visual/tactile appearance of a robot, covering wires and metallic parts with clothes, and the auditory effect by enabling or disabling the connector of the hand. The experiment consists in a hugging interaction between the participants and the humanoid robot ARMAR-IIIb. Results after participation of 24 subjects confirm the positive effect from using clothes to modify the appearance and the negative effect of noise and vibration
Neutrinoless Double Beta Decay and H^{\pm\pm}\to {l'}^\pm l^\pm Decays in the Higgs Triplet Model
The connection between the neutrinoless double beta ((\beta\beta)_{0 \nu}-)
decay effective Majorana mass, |M_{ee}|, and the branching ratios of the decays
H^{\pm\pm}\to l^\pm {l'}^\pm, l,{l'}= e,\mu, of the doubly charged Higgs boson
H^{\pm\pm} is analysed within the Higgs Triplet Model of neutrino mass
generation. We work in the version of the model with explicit breaking of the
total lepton charge conservation, in which H^{\pm\pm}\to l^\pm {l'}^\pm, l,{l'}
= e,\mu,\tau, are the dominant decay modes of H^{\pm\pm}. It is assumed also
that H^{\pm\pm} are relatively light so that they can be produced at LHC and
the branching ratios of interest measured. Taking into account the current and
prospective uncertainties in the values of the neutrino mixing parameters most
relevant for the problem studied - the atmospheric neutrino mixing angle
\theta_{23} and the CHOOZ angle \theta_{13}, and allowing the lightest neutrino
mass and the CP violating Dirac and Majorana phases to vary in the intervals
[0, 0.3 eV] and [0, 2\pi], respectively, we derive the regions of values of
BR(H^{\pm\pm}\to e^\pm e^\pm) and BR(H^{\pm\pm}\to e^\pm \mu^\pm) for which
|M_{ee}|\geq 0.05 eV, or |M_{ee}| < 0.05 eV. This is done for neutrino mass
spectrum with normal ordering, inverted ordering and in the case when the type
of the spectrum is not known, and i) without using the possible additional data
on BR(H^{\pm\pm}\to \mu^\pm \mu^\pm), ii) using prospective data on
BR(H^{\pm\pm}\to \mu^\pm \mu^\pm). In the latter case results for several
values of BR(H^{\pm\pm}\to \mu^\pm\mu^\pm) are presented.Comment: 21 pages, 10 fig
Molecular simulation of chevrons in confined smectic liquid crystals
Chevron structures adopted by confined smectic liquid crystals
are investigated via molecular dynamics simulations of the Gay-Berne
model. The chevrons are formed by quenching nematic films confined
between aligning planar substrates whose easy axes have opposing
azimuthal components. When the substrates are perfectly smooth, the
chevron formed migrates rapidly towards one of the confining walls to
yield a tilted layer structure. However, when substrate roughness is
included, by introducing a small-amplitude modulation to the particle-
substrate interaction well-depth, a symmetric chevron is formed which
remains stable over sufficiently long runtimes for detailed structural
information, such as the relevant order parameters and director orien-
tation, to be determined. For both smooth and rough boundaries, the
smectic order parameter remains non-zero across the entire chevron,
implying that layer identity is maintained across the chevron tip. Also, when the surface-stabilised chevron does eventually revert to a tilted layer structure, it does so via surface slippage, such that layer integrity is maintained throughout the chevron to tilted layer relaxation process.
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Identification of MSRA gene on chromosome 8p as a candidate metastasis suppressor for human hepatitis B virus-positive hepatocellular carcinoma
<p>Abstract</p> <p>Background</p> <p>The prognosis of patients with hepatocellular carcinoma (HCC) still remains very dismal, which is mainly due to metastasis. In our previous studies, we found that chromosome 8p deletions might contribute to metastasis of HCC. In this study, we aimed to identify the candidate metastatic suppressor gene on chromosome 8p.</p> <p>Methods</p> <p>Oligo-nucleotide microarrays which included 322 genes on human chromosome 8p were constructed to analyze the difference in gene expression profiles between HCC tissues with and without metastasis. The leading differentially expressed genes were identified and selected for further analysis by real-time PCR and Western blotting. Recombinant expression plasmid vectors for each target gene were constructed and transfected into HCC cells and its <it>in vitro </it>effects on proliferation and invasion of HCC cells were also investigated.</p> <p>Results</p> <p>Sixteen leading differentially expressed genes were identified from the HCC tissues with metastasis compared with those without metastasis (<it>p </it>< 0.01, <it>q </it>< 16 %). Among of the 10 significantly down-regulated genes in HCC with metastasis, methionine sulfoxide reductase A (<it>MSRA</it>) had the lowest <it>p </it>value and false discovery rate (FDR), and was considered as a potential candidate for metastasis suppressor gene. Real-time PCR and Western blotting confirmed that the mRNA and protein expression levels of <it>MSRA </it>were significantly decreased in HCC with metastasis compared with those without metastasis (<it>p </it>< 0.001), and <it>MSRA </it>mRNA level in HCCLM6 cells (with high metastatic potential) was also much lower than that of other HCC cell lines. Transfection of a recombinant expression plasmid vector and overexpression of <it>MSRA </it>gene could obviously inhibit cell colony formation (4.33 ± 2.92 vs. 9.17 ± 3.38, <it>p </it>= 0.008) and invasion (7.40 ± 1.67 vs. 17.20 ± 2.59, <it>p</it>= 0.0001) of HCCLM6 cell line.</p> <p>Conclusion</p> <p><it>MSRA </it>gene on chromosome 8p might possess metastasis suppressor activity in HCC.</p
Integration of emotion expression and visual tracking locomotion based on vestibulo-ocular reflex
Personal robots anticipated to become popular in the future are required to be active in joint work and community life with humans. These personal robots must recognize changing environment and must conduct adequate actions like human. Visual tracking can be said as a fundamental function from the view point of environmental sensing and reflex reaction against it. The authors developed a visual tracking motion algorithm by using upper body. Then, we integrated it with an online walking pattern generator and developed a visual tracking biped locomotion. Finally, we conducted an experimental evaluation with emotion expression. © 2010 IEEE
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