149 research outputs found
Semantic Representation and Dependency Learning for Multi-Label Image Recognition
Recently many multi-label image recognition (MLR) works have made significant
progress by introducing pre-trained object detection models to generate lots of
proposals or utilizing statistical label co-occurrence enhance the correlation
among different categories. However, these works have some limitations: (1) the
effectiveness of the network significantly depends on pre-trained object
detection models that bring expensive and unaffordable computation; (2) the
network performance degrades when there exist occasional co-occurrence objects
in images, especially for the rare categories. To address these problems, we
propose a novel and effective semantic representation and dependency learning
(SRDL) framework to learn category-specific semantic representation for each
category and capture semantic dependency among all categories. Specifically, we
design a category-specific attentional regions (CAR) module to generate
channel/spatial-wise attention matrices to guide model to focus on
semantic-aware regions. We also design an object erasing (OE) module to
implicitly learn semantic dependency among categories by erasing semantic-aware
regions to regularize the network training. Extensive experiments and
comparisons on two popular MLR benchmark datasets (i.e., MS-COCO and Pascal VOC
2007) demonstrate the effectiveness of the proposed framework over current
state-of-the-art algorithms.Comment: 25 pages, 7 figure
Chat-PM: A Class of Composite Hybrid Aerial/Terrestrial Precise Manipulator
This paper concentrates on the development of Chat-PM, a class of composite
hybrid aerial/terrestrial manipulator, in concern with composite configuration
design, dynamics modeling, motion control and force estimation. Compared with
existing aerial or terrestrial mobile manipulators, Chat-PM demonstrates
advantages in terms of reachability, energy efficiency and manipulation
precision. To achieve precise manipulation in terrestrial mode, the dynamics is
analyzed with consideration of surface contact, based on which a cascaded
controller is designed with compensation for the interference force and torque
from the arm. Benefiting from the kinematic constraints caused by the surface
contact, the position deviation and the vehicle vibration are effectively
decreased, resulting in higher control precision of the end gripper. For
manipulation on surfaces with unknown inclination angles, the moving horizon
estimation (MHE) is exploited to obtain the precise estimations of force and
inclination angle, which are used in the control loop to compensate for the
effect of the unknown surface. Real-world experiments are performed to evaluate
the superiority of the developed manipulator and the proposed controllers
Short-term motion prediction of floating offshore wind turbine based on muti-input LSTM neural network
Peer reviewe
Purification and characterization of a novel defensin from the salivary glands of the black fly, Simulium bannaense
BACKGROUND: Black flies (Diptera: Simuliidae) are haematophagous insects that can cause allergic reactions and act as vectors of pathogens. Although their saliva has been thought to contain a diverse array of physiologically active molecules, little information is available on antimicrobial factors in black fly salivary glands, especially no defensins have been reported so far. METHODS: A novel cationic defensin designated SibaDef was purified using reverse phase high-performance liquid chromatography (RP-HPLC) from the salivary glands of the black fly Simulium bannaense. The amino acid sequence of SibaDef was determined by a combination method of automated Edman degradation and cDNA sequencing. The morphologic changes of Gram-positive bacteria Staphylococcus aureus or Bacillus subtilis treated with SibaDef were assessed by scanning electron microscopy (SEM). Quantitative PCR (qPCR) was performed to analyze the expression of SibaDef mRNA in whole bodies of insects after oral infection with the bacteria S. aureus or B. subtilis. RESULTS: Surprisingly, the phylogenetic analysis of defensin-related amino acid sequences demonstrated that SibaDef is most closely related to defensins from the human body louse Pediculus humanus corporis (Anoplura: Pediculidae), rather than to other dipteran defensins. SibaDef showed potent antimicrobial activities against Gram-positive bacteria with minimal inhibitory concentrations (MICs) ranging from 0.83Â ÎŒM to 2.29Â ÎŒM. SEM analysis indicated that SibaDef killed microorganisms through the disruption of cell membrane integrity. The transcript levels of SibaDef in the bacteria-immunized flies increased with the time course, reaching maximum at 36Â h and then slowly decreased from that time point. CONCLUSIONS: Our results indicate that SibaDef is involved in the innate humoral response of the black fly S. bannaense, and it might play a significant role in the defence against microorganisms in both sugar and blood meals
A novel method for objectively, rapidly and accurately evaluating burn depth via near infrared spectroscopy
The accurate and objective evaluation of burn depth is a significant challenge in burn wound care. Herein, we used near infrared spectroscopy (NIRS) technology to measure the different depth of thermal burns in ex vivo porcine models. Based on the intensity of the spectral signals and the diffuse reflection theory, we extracted the optical parameters involved in functional (total hemoglobin and water content) and structural (tissue scattered size and scattered particles) features that reflect the changes in burn depth. Next, we applied support vector regression to construct a model including the optical property parameters and the burn depth. Finally, we histologically verified the burn depth data collected via NIRS. The results showed that our inversion model could achieve an average relative error of about 7.63%, while the NIRS technology diagnostic accuracy was in the range of 50 ÎŒm. For the first time, this novel technique provides physicians with real-time burn depth information objectively and accurately
A modified âskeleton/skinâ strategy for designing CoNiP nanosheets arrayed on graphene foam for on/off switching of NaBH hydrolysis
CoNiP nanosheet array catalysts were successfully prepared on three-dimensional (3D) graphene foam using hydrothermal synthesis. These catalysts were prepared using 3D Niâgraphene foam (Ni/GF), comprising nickel foam as the âskeletonâ and reduced graphene oxide as the âskinâ. This unique continuous modified âskeleton/skinâ structure ensure that the catalysts had a large surface area, excellent conductivity, and sufficient surface functional groups, which promoted in situ CoNiP growth, while also optimizing the hydrolysis of sodium borohydride. The nanosheet arrays were fully characterized and showed excellent catalytic performance, as supported by density functional theory calculations. The hydrogen generation rate and activation energy are 6681.34 mL min g and 31.2 kJ mol, respectively, outperforming most reported cobalt-based catalysts and other precious metal catalysts. Furthermore, the stability of mockstrawberry-like CoNiP catalyst was investigated, with 74.9% of the initial hydrogen generation rate remaining after 15 cycles. The catalytic properties, durability, and stability of the catalyst were better than those of other catalysts reported previously
The bracteatus pineapple genome and domestication of clonally propagated crops
Domestication of clonally propagated crops such as pineapple from South America was hypothesized to be a 'one-step operation'. We sequenced the genome of Ananas comosus var. bracteatus CB5 and assembled 513âMb into 25 chromosomes with 29,412 genes. Comparison of the genomes of CB5, F153 and MD2 elucidated the genomic basis of fiber production, color formation, sugar accumulation and fruit maturation. We also resequenced 89 Ananas genomes. Cultivars 'Smooth Cayenne' and 'Queen' exhibited ancient and recent admixture, while 'Singapore Spanish' supported a one-step operation of domestication. We identified 25 selective sweeps, including a strong sweep containing a pair of tandemly duplicated bromelain inhibitors. Four candidate genes for self-incompatibility were linked in F153, but were not functional in self-compatible CB5. Our findings support the coexistence of sexual recombination and a one-step operation in the domestication of clonally propagated crops. This work guides the exploration of sexual and asexual domestication trajectories in other clonally propagated crops
Analysis of complete mitogenomes and phylogenetic relationships of Frontopsylla spadix and Neopsylla specialis
Fleas represent a group of paramount medical significance, subsisting on blood and acting as vectors for an array of naturally occurring diseases. These pathogens constitute essential elements within the plague biome, exerting deleterious effects on both human and livestock health. In this study, we successfully assembled and sequenced the whole mitochondrial genome of Frontopsylla spadix and Neopsylla specialis using long-range PCR and next-generation sequencing technologies. The mitogenomes of F. spadix and N. specialis both have 37 genes with full lengths of 15,085 bp and 16,820 bp, respectively. The topology of the phylogenetic tree elucidates that species F. spadix is clustered in a branch alongside other members of the family Leptopsyllidae, whereas species N. specialis is a sister taxon to Dorcadia ioffi and Hystrichopsylla weida qinlingensis. It also suggests that Pulicidae form a monophyletic clade, Ctenopthalmidae, Hystrichopsyllidae, Vermipsyllidae form a sister group to Ceratophyllidae/Leptopsyllidae group. The mitochondrial genomes of F. spadix and N. specialis were sequenced for the first time, which will contribute to a more comprehensive phylogenetic analysis of the Siphonaptera order. The foundation for subsequent systematic studies, and molecular biology of fleas was established
Downregulation of p16 Decreases Biliary Damage and Liver Fibrosis in the Mdr2 / Mouse Model of Primary Sclerosing Cholangitis
Biliary senescence and hepatic fibrosis are hallmarks of cholangiopathies including primary sclerosing cholangitis (PSC). Senescent cholangiocytes display senescence-associated secretory phenotypes [SASPs, e.g., transforming growth factor-1 (TGF-1)] that further increase biliary senescence (by an autocrine loop) and trigger liver fibrosis by paracrine mechanisms. The aim of this study was to determine the effect of p16 inhibition and role of the TGF-1/microRNA (miR)-34a/sirtuin 1 (SIRT1) axis in biliary damage and liver fibrosis in the Mdr2/ mouse model of PSC. We treated (i) in vivo male wild-type (WT) and Mdr2/ mice with p16 Vivo-Morpholino or controls before measuring biliary mass [intrahepatic bile duct mass (IBDM)] and senescence, biliary SASP levels, and liver fibrosis, and (ii) in vitro intrahepatic murine cholangiocyte lines (IMCLs) with small interfering RNA against p16 before measuring the mRNA expression of proliferation, senescence, and fibrosis markers. p16 and miR-34a increased but SIRT1 decreased in Mdr2/ mice and PSC human liver samples compared to controls. p16 immunoreactivity and biliary senescence and SASP levels increased in Mdr2/ mice but decreased in Mdr2/ mice treated with p16 Vivo-Morpholino. The increase in IBDM and hepatic fibrosis (observed in Mdr2/ mice) returned to normal values in Mdr2/ mice treated with p16 Vivo-Morpholino. TGF-1 immunoreactivity and biliary SASPs levels were higher in Mdr2/ compared to those of WT mice but returned to normal values in Mdr2/ mice treated with p16 Vivo-Morpholino. The expression of fibrosis/senescence markers decreased in cholangiocytes from Mdr2/ mice treated with p16 Vivo-Morpholino (compared to Mdr2/ mice) and in IMCLs (after p16 silencing) compared to controls. Modulation of the TGF-1/miR-34a/SIRT1 axis may be important in the management of PSC phenotypes
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