Herbig Ae/Be candidate stars in the innermost Galactic disk: Quartet cluster

In order to investigate the Galactic-scale environmental effects on the evolution of protoplanetary disks, we explored the near-infrared (NIR) disk fraction of the Quartet cluster, which is a young cluster in the innermost Galactic disk at the Galactocentric radius Rg ~ 4 kpc. Because this cluster has a typical cluster mass of ~10^3 M_sun as opposed to very massive clusters, which have been observed in previous studies (>10^4 M_sun), we can avoid intra-cluster effects such as strong UV field from OB stars. Although the age of the Quartet is previously estimated to be 3-8 Myr old, we find that it is most likely ~3-4.5 Myr old. In moderately deep JHK images from the UKIDSS survey, we found eight HAeBe candidates in the cluster, and performed K-band medium-resolution ($R \equiv \Delta \lambda / \lambda ~ 800$) spectroscopy for three of them with the Subaru 8.2 m telescope. These are found to have both Br\gamma absorption lines as well as CO bandhead emission, suggesting that they are HAeBe stars with protoplanetary disks. We estimated the intermediate-mass disk fraction (IMDF) to be ~25 % for the cluster, suggesting slightly higher IMDF compared to those for young clusters in the solar neighborhood with similar cluster age, although such conclusion should await future spectroscopic study of all candidates of cluster members.Comment: 15 pages, 8 figures, and 2 Tables. Accepted for publication in the Astrophysical Journa

Seasonal variations of atmospheric C2-C7 nonmethane hydrocarbons in Tokyo

Eighteen C2-C7 NMHCs (nonmethane hydrocarbons) were measured hourly during the Integrated Measurement Program for Aerosol and Oxidant Chemistry in Tokyo (IMPACT) measurement campaigns conducted in central Tokyo during four different periods (summer/autumn of 2003 and winter/summer of 2004). The ambient atmospheric concentrations of NMHCs showed an inverse correlation with wind speed and mixing height and were significantly affected by mesoscale weather conditions. The mixing ratio of isoprene tightly correlated with solar flux and temperature in summer, as it was dominantly emitted by the local vegetation. All the observed NMHCs except isoprene showed high correlation with each other in winter (r2 > 0.5), suggesting concurrent accumulation under stagnant condition and common sources. Emission ratios were calculated on the basis of the correlation with carbon monoxide and ethyne. Compared to the typical winter NMEC composition, during summer there was a significant increase (up to 7 times higher than wintertime) of C4-C5 alkanes from ftiel evaporation; of C2-C3 alkenes, n-hexane and benzene from chemical industry; and of toluene from local manufacturers, reflecting the temperature dependence of these evaporative emissions. In addition to the online measurements in Tokyo, canister sampling at a suburban site (Kisai) followed by multidimensional GC analyses was conducted during the summer campaign in 2004. The atmospheric concentrations of longer-lived compounds (≥ several days) at Kisai showed the buildup under sea breeze circulation. The average ambient, concentration of toluene was 2 times higher than that in central Tokyo, likely because of substantial emissions from local industries as reported in the prefectural statistics. Copyright 2007 by the American Geophysical Union

On Haagerup's list of potential principal graphs of subfactors

We show that any graph, in the sequence given by Haagerup in 1991 as that of candidates of principal graphs of subfactors, is not realized as a principal graph except for the smallest two. This settles the remaining case of a previous work of the first author.Comment: 19 page

LLM-Based Human-Robot Collaboration Framework for Manipulation Tasks

This paper presents a novel approach to enhance autonomous robotic manipulation using the Large Language Model (LLM) for logical inference, converting high-level language commands into sequences of executable motion functions. The proposed system combines the advantage of LLM with YOLO-based environmental perception to enable robots to autonomously make reasonable decisions and task planning based on the given commands. Additionally, to address the potential inaccuracies or illogical actions arising from LLM, a combination of teleoperation and Dynamic Movement Primitives (DMP) is employed for action correction. This integration aims to improve the practicality and generalizability of the LLM-based human-robot collaboration system.Comment: IEEE MHS 202

Quantized Anomalous Hall Effect in Two-Dimensional Ferromagnets - Quantum Hall Effect from Metal -

We study the effect of disorder on the anomalous Hall effect (AHE) in two-dimensional ferromagnets. The topological nature of AHE leads to the integer quantum Hall effect from a metal, i.e., the quantization of $\sigma_{xy}$ induced by the localization except for the few extended states carrying Chern number. Extensive numerical study on a model reveals that Pruisken's two-parameter scaling theory holds even when the system has no gap with the overlapping multibands and without the uniform magnetic field. Therefore the condition for the quantized AHE is given only by the Hall conductivity $\sigma_{xy}$ without the quantum correction, i.e., $|\sigma_{xy}| > e^2/(2h)$.Comment: 5 pages, 4 figures, REVTe

Nondestructive characterization of Antarctic micrometeorites collected at the Dome Fuji Station by synchrotron radiation X-ray fluorescence analysis

The bulk trace element composition (Ca, Ti, Cr, Mn, Ni Cu, Zn, Ge, Se, Rb, Sr, Y, Zr, Mo) of eighty-three Antarctic micrometeorites was nondestructively analyzed using synchrotron radiation X-ray fluorescence analysis (SR-XRF), and these elements were characterized in terms of their abundance ratio relative to Murchison matrix composition. The relationship between heating history and chemical composition is also examined. We found a complementary relationship among I-type, S-type and unmelted AMMs in the micrometeorites\u27 elemental abundance, which is consistent with the hypothesis that I-type and S-type spherules were separated from chondritic meteoroids

IN VIVO PEPTIDES POSITIVELY SELECT AND FINE-TUNE T CELLS

The affinity for TCR interactions with self-peptide/MHC complexes (pMHC) in the thymus critically affects immature thymocytes that newly express TCRs. Previous fetal thymus organ culture experiments have indicated that difference in the affinity for thymic TCR/pMHC interactions not only determines thymocyte fate between positive and negative selection, but also affects Ag responsiveness of positively selected thymocytes. In the current study, we examined whether TCR/pMHC affinity during positive selection in the thymus would further affect Ag responsiveness of mature T cells in the periphery. To do so, OVA peptide variants were in vivo administered to TAP1-deficient OT-I/TCR-transgenic mice in which T cell development was otherwise arrested at CD4+CD8+ thymocytes because of the lack of self-pMHC presentation in thymic APCs. We found that a group of peptide variants induced the transient generation of OT-I CD8+ T cells in the thymus and the periphery. We also noticed that the affinity threshold for positive and negative selection detected in adult mice in vivo was higher than that measured in fetal thymus organ culture experiments in vitro. Interestingly, we further found that the affinity for positively selecting peptides proportionally affected TCR responsiveness of peripheral naive CD8+ T cells. These results indicate that in vivo administration of a peptide can promote T cell selection in the thymus and the affinity for TCR/pMHC interaction during positive selection fine-tunes Ag responsiveness of peripheral T cells

Murine Retrovirus Escapes from Murine APOBEC3 via Two Distinct Novel Mechanisms

SummaryAPOBEC3G (A3G) is an antiretroviral host factor that functions by deaminating dC to dU in retroviral cDNA [1–5]. HIV-1 Vif protein counteracts A3G via a ubiquitin-proteasome pathway [6–12]. In the case of a simple retrovirus such as the murine leukemia virus (MLV), it remains unclear why it can replicate in cells expressing APOBEC3 (A3) even though it doesn't possess any accessory proteins such as Vif [2, 13]. In this study, we demonstrate that MLV escapes from murine A3 (mA3) via two distinct novel mechanisms. First, viral RNA (vRNA) blocks the binding of mA3 to Gag, resulting in the exclusion of mA3 from MLV virions. Second, viral protease (vPR) cleaves mA3 after maturation of virions. Here, we suggest that each virus has its own strategy to escape from A3 proteins and that these mechanisms might be used by other viruses that do not possess Vif-like protein. On the other hand, mice possess another form of mA3, Δexon5, that escapes from the cleavage by vPR to show more antiviral activity than the wild type mA3. This also suggests that battles between host intrinsic immunity and viruses have led to the evolution of proteins on both sides

Failure analyses for plate monotonic/cyclic and elbow out-of-plane cyclic loading tests using the Gurson–Tvergaard–Needleman model

In this study, an analytical approach is proposed to simulate the failure behavior of a thinned-wall pipe elbow subjected to internal pressure and out-of-plane cyclic bending loads. This approach incorporates the Gurson–Tvergaard–Needleman model, whose parameters were determined by the plate monotonic tensile test and finite element analyses. The applicability of this analytical approach for low-cycle fatigue failure was confirmed through experiments and simulations. The analytical results captured the failure behavior of the pipe elbow during the out-of-plane cyclic bending test. This finding suggests that the analytical approach can be used for nonlinear deformation evaluation and multiaxial low-cycle fatigue assessment of piping systems.journal articl