2,364 research outputs found
Residual-Sparse Fuzzy -Means Clustering Incorporating Morphological Reconstruction and Wavelet frames
Instead of directly utilizing an observed image including some outliers,
noise or intensity inhomogeneity, the use of its ideal value (e.g. noise-free
image) has a favorable impact on clustering. Hence, the accurate estimation of
the residual (e.g. unknown noise) between the observed image and its ideal
value is an important task. To do so, we propose an
regularization-based Fuzzy -Means (FCM) algorithm incorporating a
morphological reconstruction operation and a tight wavelet frame transform. To
achieve a sound trade-off between detail preservation and noise suppression,
morphological reconstruction is used to filter an observed image. By combining
the observed and filtered images, a weighted sum image is generated. Since a
tight wavelet frame system has sparse representations of an image, it is
employed to decompose the weighted sum image, thus forming its corresponding
feature set. Taking it as data for clustering, we present an improved FCM
algorithm by imposing an regularization term on the residual between
the feature set and its ideal value, which implies that the favorable
estimation of the residual is obtained and the ideal value participates in
clustering. Spatial information is also introduced into clustering since it is
naturally encountered in image segmentation. Furthermore, it makes the
estimation of the residual more reliable. To further enhance the segmentation
effects of the improved FCM algorithm, we also employ the morphological
reconstruction to smoothen the labels generated by clustering. Finally, based
on the prototypes and smoothed labels, the segmented image is reconstructed by
using a tight wavelet frame reconstruction operation. Experimental results
reported for synthetic, medical, and color images show that the proposed
algorithm is effective and efficient, and outperforms other algorithms.Comment: 12 pages, 11 figur
Frequency Perception Network for Camouflaged Object Detection
Camouflaged object detection (COD) aims to accurately detect objects hidden
in the surrounding environment. However, the existing COD methods mainly locate
camouflaged objects in the RGB domain, their performance has not been fully
exploited in many challenging scenarios. Considering that the features of the
camouflaged object and the background are more discriminative in the frequency
domain, we propose a novel learnable and separable frequency perception
mechanism driven by the semantic hierarchy in the frequency domain. Our entire
network adopts a two-stage model, including a frequency-guided coarse
localization stage and a detail-preserving fine localization stage. With the
multi-level features extracted by the backbone, we design a flexible frequency
perception module based on octave convolution for coarse positioning. Then, we
design the correction fusion module to step-by-step integrate the high-level
features through the prior-guided correction and cross-layer feature channel
association, and finally combine them with the shallow features to achieve the
detailed correction of the camouflaged objects. Compared with the currently
existing models, our proposed method achieves competitive performance in three
popular benchmark datasets both qualitatively and quantitatively.Comment: Accepted by ACM MM 202
The functions and regulatory pathways of S100A8/A9 and its receptors in cancers
Inflammation primarily influences the initiation, progression, and deterioration of many human diseases, and immune cells are the principal forces that modulate the balance of inflammation by generating cytokines and chemokines to maintain physiological homeostasis or accelerate disease development. S100A8/A9, a heterodimer protein mainly generated by neutrophils, triggers many signal transduction pathways to mediate microtubule constitution and pathogen defense, as well as intricate procedures of cancer growth, metastasis, drug resistance, and prognosis. Its paired receptors, such as receptor for advanced glycation ends (RAGEs) and toll-like receptor 4 (TLR4), also have roles and effects within tumor cells, mainly involved with mitogen-activated protein kinases (MAPKs), NF-ÎşB, phosphoinositide 3-kinase (PI3K)/Akt, mammalian target of rapamycin (mTOR) and protein kinase C (PKC) activation. In the clinical setting, S100A8/A9 and its receptors can be used complementarily as efficient biomarkers for cancer diagnosis and treatment. This review comprehensively summarizes the biological functions of S100A8/A9 and its various receptors in tumor cells, in order to provide new insights and strategies targeting S100A8/A9 to promote novel diagnostic and therapeutic methods in cancers
Model-independent test of the parity symmetry of gravity with gravitational waves
Gravitational wave (GW) data can be used to test the parity symmetry of
gravity by investigating the difference between left-hand and right-hand
circular polarization modes. In this article, we develop a method to decompose
the circular polarizations of GWs produced during the inspiralling stage of
compact binaries, with the help of stationary phase approximation. The foremost
advantage is that this method is simple, clean, independent of GW waveform, and
is applicable to the existing detector network. Applying it to the mock data,
we test the parity symmetry of gravity by constraining the velocity
birefringence of GWs. If a nearly edge-on binary neutron-stars with observed
electromagnetic counterparts at 40 Mpc is detected by the second-generation
detector network, one could derive the model-independent test on the parity
symmetry in gravity: the lower limit of the energy scale of parity violation
can be constrained within .Comment: 9 pages,4 figs, EPJC accepte
Improving End-to-End Text Image Translation From the Auxiliary Text Translation Task
End-to-end text image translation (TIT), which aims at translating the source
language embedded in images to the target language, has attracted intensive
attention in recent research. However, data sparsity limits the performance of
end-to-end text image translation. Multi-task learning is a non-trivial way to
alleviate this problem via exploring knowledge from complementary related
tasks. In this paper, we propose a novel text translation enhanced text image
translation, which trains the end-to-end model with text translation as an
auxiliary task. By sharing model parameters and multi-task training, our model
is able to take full advantage of easily-available large-scale text parallel
corpus. Extensive experimental results show our proposed method outperforms
existing end-to-end methods, and the joint multi-task learning with both text
translation and recognition tasks achieves better results, proving translation
and recognition auxiliary tasks are complementary.Comment: Accepted at the 26TH International Conference on Pattern Recognition
(ICPR 2022
Interplay between residual protease activity in commercial lactases and the subsequent digestibility of β-casein in a model system
One of the conventional ways to produce lactose-hydrolyzed (LH) milk is via the addition of commercial lactases into heat-treated milk in which lactose is hydrolyzed throughout storage. This post-hydrolysis method can induce proteolysis in milk proteins due to protease impurities remaining in commercial lactase preparations. In this work, the interplay between lactose hydrolysis, proteolysis, and glycation was studied in a model system of purified β-casein (β-CN), lactose, and lactases using peptidomic methods. With a lactase presence, the proteolysis of β-CN was found to be increased during storage. The protease side-activities mainly acted on the hydrophobic C-terminus of β-CN at Ala, Pro, Ile, Phe, Leu, Lys, Gln, and Tyr positions, resulting in the formation of peptides, some of which were N-terminal glycated or potentially bitter. The proteolysis in β-CN incubated with a lactase was shown to act as a kind of “pre-digestion”, thus increasing the subsequent in vitro digestibility of β-CN and drastically changing the peptide profiles of the in vitro digests. This model study provides a better understanding of how the residual proteases in commercial lactase preparations affect the quality and nutritional aspects of β-CN itself and could be related to its behavior in LH milk
Toxoplasma gondii cathepsin proteases are undeveloped prominent vaccine antigens against toxoplasmosis
BACKGROUND: Toxoplasma gondii, an obligate intracellular apicomplexan parasite, infects a wide range of warm-blooded animals including humans. T. gondii expresses five members of the C1 family of cysteine proteases, including cathepsin B-like (TgCPB) and cathepsin L-like (TgCPL) proteins. TgCPB is involved in ROP protein maturation and parasite invasion, whereas TgCPL contributes to proteolytic maturation of proTgM2AP and proTgMIC3. TgCPL is also associated with the residual body in the parasitophorous vacuole after cell division has occurred. Both of these proteases are potential therapeutic targets in T. gondii. The aim of this study was to investigate TgCPB and TgCPL for their potential as DNA vaccines against T. gondii. METHODS: Using bioinformatics approaches, we analyzed TgCPB and TgCPL proteins and identified several linear-B cell epitopes and potential Th-cell epitopes in them. Based on these results, we assembled two single-gene constructs (TgCPB and TgCPL) and a multi-gene construct (pTgCPB/TgCPL) with which to immunize BALB/c mice and test their effectiveness as DNA vaccines. RESULTS: TgCPB and TgCPL vaccines elicited strong humoral and cellular immune responses in mice, both of which were Th-1 cell mediated. In addition, all of the vaccines protected the mice against infection with virulent T. gondii RH tachyzoites, with the multi-gene vaccine (pTgCPB/TgCPL) providing the highest level of protection. CONCLUSIONS: T. gondii CPB and CPL proteases are strong candidates for development as novel DNA vaccines
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