344 research outputs found
Weakly Supervised Silhouette-based Semantic Scene Change Detection
This paper presents a novel semantic scene change detection scheme with only
weak supervision. A straightforward approach for this task is to train a
semantic change detection network directly from a large-scale dataset in an
end-to-end manner. However, a specific dataset for this task, which is usually
labor-intensive and time-consuming, becomes indispensable. To avoid this
problem, we propose to train this kind of network from existing datasets by
dividing this task into change detection and semantic extraction. On the other
hand, the difference in camera viewpoints, for example, images of the same
scene captured from a vehicle-mounted camera at different time points, usually
brings a challenge to the change detection task. To address this challenge, we
propose a new siamese network structure with the introduction of correlation
layer. In addition, we create a publicly available dataset for semantic change
detection to evaluate the proposed method. The experimental results verified
both the robustness to viewpoint difference in change detection task and the
effectiveness for semantic change detection of the proposed networks. Our code
and dataset are available at https://github.com/xdspacelab/sscdnet.Comment: Accepted at the 2020 IEEE International Conference on Robotics and
Automation (ICRA). Code and dataset are available at
https://github.com/xdspacelab/sscdne
Similarities and uniqueness of Ly emitters among star-forming galaxies at z=2.5
We conducted a deep narrow-band imaging survey with the Subaru Prime Focus
Camera on the Subaru Telescope and constructed a sample of Ly emitters
(LAEs) at z=2.53 in the UDS-CANDELS field where a sample of H emitters
(HAEs) at the same redshift is already obtained from our previous narrow-band
observation at NIR. The deep narrow-band and multi broadband data allow us to
find LAEs of stellar masses and star-formation rates (SFRs) down to
M and 0.2 M/yr, respectively. We show
that the LAEs are located along the same mass-SFR sequence traced by normal
star-forming galaxies such as HAEs, but towards a significantly lower mass
regime. Likewise, LAEs seem to share the same mass--size relation with typical
star-forming galaxies, except for the massive LAEs, which tend to show
significantly compact sizes. We identify a vigorous mass growth in the central
part of LAEs: the stellar mass density in the central region of LAEs increases
as their total galaxy mass grows. On the other hand, we see no Ly line
in emission for most of the HAEs. Rather, we find that the Ly feature
is either absent or in absorption (Ly absorbers; LAAs), and its
absorption strength may increase with reddening of the UV continuum slope. We
demonstrate that a deep Ly narrow-band imaging like this study is able
to search for not only LAEs but also LAAs in a certain redshift slice. This
work suggests that LAEs trace normal star-forming galaxies in the low-mass
regime, while they remain as a unique population because the majority of HAEs
are not LAEs.Comment: 20 pages, 18 figures, 3 tables, accepted for publication in MNRA
Suppressive activity of tiotropium bromide on matrix metalloproteinase production from lung fibroblasts in vitro
Kazuhito Asano1, Yusuke Shikama2, Yasuhiro Shibuya2, Hiroaki Nakajima2, Ken-ichi Kanai3, Naohiro Yamada3, Harumi Suzaki31Division of Physiology, School of Nursing and Rehabilitation Sciences; 2Respiratory Disease Center, Showa University Northern Yokohama Hospital, Yokohama, Japan; 3Department of Otolaryngology, School of Medicine, Showa University, Tokyo, JapanBackground: Chronic obstructive pulmonary disease (COPD) is characterized by airway remodeling with an accumulation of inflammatory cells. There is also increasing evidence that metalloproteinases (MMPs) may contribute to the pathogenesis of COPD, but the influence of agents that used for the treatment of COPD is not well understood.Objective: We evaluated whether tiotropium bromide hydrate (TBH), a M3 muscarinic receptor antagonist, could inhibit MMP production from lung fibroblasts (LFs) in response to tumor necrosis factor (TNF)-α stimulation.Methods: LFs were established from normal lung tissues taken from patients with lung tumors. LFs (5 × 105 cells/ml) were stimulated with TNF-α in the presence of various concentrations of TBH. After 24 h, culture supernatants were obtained and assayed for the levels of MMPs and tissue inhibitor of metalloproteinases (TIMPs) by ELISA. The influence of TBH on mRNA expression of MMPs and TIMPs in 4 h-cultured cells was also examined by real-time RT-PCR. Furthermore, nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) in LFs treated with TBH for 4 h was examined by ELISA.Results: TBH at more than 15 pg/ml inhibited the production of MMP-2 from LFs after TNF-α stimulation, whereas TIMP-1 and TIMP-2 production was scarcely affected by TBH through the suppression of both mRNA expression and transcription factor, NF-κB, activation in LFs induced by TNF-α stimulation.Conclusion: These results suggest that the attenuating effect of TBH on MMP-2 production from LFs induced by inflammatory stimulation may be additional beneficial therapeutic effects not directly relating to its bronchodilatory effects.Keywords: tiotropium, lung fibroblasts, matrix metalloproteinases, suppression, in vitr
Detection of the Far-infrared [O III] and Dust Emission in a Galaxy at Redshift 8.312: Early Metal Enrichment in the Heart of the Reionization Era
We present the Atacama Large Millimeter/submillimeter Array (ALMA) detection
of the [O III] 88 m line and rest-frame 90 m dust continuum emission
in a Y-dropout Lyman break galaxy (LBG), MACS0416_Y1, lying behind the Frontier
Field cluster MACS J0416.1-2403. This [O III] detection confirms the LBG with a
spectroscopic redshift of , making this object one of
the furthest galaxies ever identified spectroscopically. The observed 850
m flux density of Jy corresponds to a de-lensed total
infrared (IR) luminosity of if assuming a dust temperature of K and an
emissivity index of , yielding a large dust mass of . The ultraviolet-to-far IR spectral energy distribution modeling
where the [O III] emissivity model is incorporated suggests the presence of a
young ( Myr), star-forming (SFR yr), moderately metal-polluted ()
stellar component with a mass of . An
analytic dust mass evolution model with a single episode of star-formation does
not reproduce the metallicity and dust mass in Myr,
suggesting a pre-existing evolved stellar component with and Gyr as the origin of the
dust mass.Comment: Accepted by ApJ. 18 pages, 10 figures, 5 table
Large Population of ALMA Galaxies at z>6 with Very High [OIII]88um to [CII]158um Flux Ratios: Evidence of Extremely High Ionization Parameter or PDR Deficit?
We present our new ALMA observations targeting [OIII]88um, [CII]158um,
[NII]122um, and dust continuum emission for three Lyman break galaxies at
z=6.0293-6.2037 identified in the Subaru/Hyper Suprime-Cam survey. We clearly
detect [OIII] and [CII] lines from all of the galaxies at 4.3-11.8sigma levels,
and identify multi-band dust continuum emission in two of the three galaxies,
allowing us to estimate infrared luminosities and dust temperatures
simultaneously. In conjunction with previous ALMA observations for six galaxies
at z>6, we confirm that all the nine z=6-9 galaxies have high [OIII]/[CII]
ratios of L[OIII]/L[CII]~3-20, ~10 times higher than z~0 galaxies. We also find
a positive correlation between the [OIII]/[CII] ratio and the Lya equivalent
width (EW) at the ~90% confidence level. We carefully investigate physical
origins of the high [OIII]/[CII] ratios at z=6-9 using Cloudy, and find that
high density of the interstellar medium, low C/O abundance ratio, and the
cosmic microwave background attenuation are responsible to only a part of the
z=6-9 galaxies. Instead, the observed high [OIII]/[CII] ratios are explained by
10-100 times higher ionization parameters or low photodissociation region (PDR)
covering fractions of 0-10%, both of which are consistent with our [NII]
observations. The latter scenario can be reproduced with a density bounded
nebula with PDR deficit, which would enhance the Lya, Lyman continuum, and C+
ionizing photons escape from galaxies, consistent with the [OIII]/[CII]-Lya EW
correlation we find.Comment: 20 pages, 18 figures, Accepted for publication in Ap
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