275 research outputs found
X-ray spectral correlations in a sample of Low-mass black hole X-ray binaries in the hard state
The power-law emission and reflection component provide valuable insights
into the accretion process around a black hole. In this work, thanks to the
broadband spectra coverage of \emph{the Nuclear Spectroscopic Telescope Array},
we study the spectral properties for a sample of low-mass black hole X-ray
binaries (BHXRBs). We find that there is a positive correlation between the
photon index and the reflection fraction (the ratio of the coronal
intensity that illuminates the disk to the coronal intensity that reaches the
observer), consistent with previous studies, but except for MAXI J1820+070. It
is quite interesting that this source also deviates from the well-known
``V"-shaped correlation between the photon index and the X-ray
luminosity log, when it is in the bright hard state. More
specifically, the -shaped correlation between and log is observed, as the luminosity decreases by a factor of 3 in a narrow range
from to . Furthermore, we discover a
strong positive correlation between and the X-ray luminosity for BHXRBs in
the hard state, which puts a constraint on the disk-corona coupling and the
evolution.Comment: 18 pages, 9 figures, 3 tables, Accepted for publication in Ap
NeTO:Neural Reconstruction of Transparent Objects with Self-Occlusion Aware Refraction-Tracing
We present a novel method, called NeTO, for capturing 3D geometry of solid
transparent objects from 2D images via volume rendering. Reconstructing
transparent objects is a very challenging task, which is ill-suited for
general-purpose reconstruction techniques due to the specular light transport
phenomena. Although existing refraction-tracing based methods, designed
specially for this task, achieve impressive results, they still suffer from
unstable optimization and loss of fine details, since the explicit surface
representation they adopted is difficult to be optimized, and the
self-occlusion problem is ignored for refraction-tracing. In this paper, we
propose to leverage implicit Signed Distance Function (SDF) as surface
representation, and optimize the SDF field via volume rendering with a
self-occlusion aware refractive ray tracing. The implicit representation
enables our method to be capable of reconstructing high-quality reconstruction
even with a limited set of images, and the self-occlusion aware strategy makes
it possible for our method to accurately reconstruct the self-occluded regions.
Experiments show that our method achieves faithful reconstruction results and
outperforms prior works by a large margin. Visit our project page at
\url{https://www.xxlong.site/NeTO/
A Survey of Self-supervised Learning from Multiple Perspectives: Algorithms, Applications and Future Trends
Deep supervised learning algorithms generally require large numbers of
labeled examples to achieve satisfactory performance. However, collecting and
labeling too many examples can be costly and time-consuming. As a subset of
unsupervised learning, self-supervised learning (SSL) aims to learn useful
features from unlabeled examples without any human-annotated labels. SSL has
recently attracted much attention and many related algorithms have been
developed. However, there are few comprehensive studies that explain the
connections and evolution of different SSL variants. In this paper, we provide
a review of various SSL methods from the perspectives of algorithms,
applications, three main trends, and open questions. First, the motivations of
most SSL algorithms are introduced in detail, and their commonalities and
differences are compared. Second, typical applications of SSL in domains such
as image processing and computer vision (CV), as well as natural language
processing (NLP), are discussed. Finally, the three main trends of SSL and the
open research questions are discussed. A collection of useful materials is
available at https://github.com/guijiejie/SSL
Anti-inflammatory recombinant TSG-6 stabilizes the progression of focal retinal degeneration in a murine model
<p>Abstract</p> <p>Background</p> <p>Inflammatory responses are detected in the retina of patients with age-related macular degeneration and <it>Ccl2<sup>-/-</sup>/Cx3cr1<sup>-/- </sup></it>mice on rd8 background,(<it>Ccl2<sup>-/-</sup>/Cx3cr1<sup>-/- </sup></it>mice) a model that develops progressive age-related macular degeneration-like retinal lesions including focal photoreceptor degeneration, abnormal retinal pigment epithelium and A2E accumulation. Tumor necrosis factor-inducible gene 6 protein is an anti-inflammatory protein and has been shown to improve myocardial infarction outcome and chemically injured cornea in mice by suppressing inflammation. In this study, we evaluated the effect of an intravitreous injection of recombinant TSG-6 on the retinal lesions of <it>Ccl2<sup>-/-</sup>/Cx3cr1<sup>-/- </sup></it>mice.</p> <p>Methods</p> <p>Recombinant TSG-6 (400 ng) was administered by intravitreous injection into the right eye of six-week-old C<it>cl2<sup>-/-</sup>/Cx3cr1<sup>-/- </sup></it>mice. Their left eye was injected with phosphate-buffered saline as a control. Funduscopic pictures were taken before injection and sequentially once a month after injection. The mice were killed two months after injection and the ocular histology examined. Retinal A2E, a major component of lipofuscin, was measured by high performance liquid chromatography. The microarray of ocular mRNA of 92 immunological genes was performed. The genes showing differentiated expression in microarray were further compared between the injected right eye and the contralateral (control) eye by [real-time quantitative reverse transcription polymerase chain reaction] qRT-PCR.</p> <p>Results</p> <p>The continuous monitoring of the fundus for two months showed a slower progression or alleviation of retinal lesions in the treated right eyes as compared with the untreated left eyes. Among 23 pairs of eyes, the lesion levels improved in 78.3%, stayed the same in 8.7% and progressed in 13.0%. Histology confirmed the clinical observation. Even though there was no difference in the level of A2E between the treated and the untreated eyes, microarray analysis of 92 immune genes showed that <it>IL-17a </it>was substantially decreased after the treatment. Expression of <it>TNF-α </it>showed a similar pattern to <it>IL-17a</it>. The results were consistent in duplicated arrays and confirmed by qRT-PCR.</p> <p>Conclusions</p> <p>We concluded that intravitreous administration of recombinant TSG-6 might stabilize retinal lesions in <it>Ccl2<sup>-/-</sup>/Cx3cr1<sup>-/- </sup></it>mice on rd8 background. Modulation of ocular immunological gene expressions, especially IL-17a, could be one of the mechanisms.</p
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