Line-Features-Based Pose Estimation Method for the Disc Cutter Holder of Shield Machine.

To achieve automatic disc cutter replacement of shield machines, measuring the accurate pose of the disc cutter holder by machine vision is crucial. However, under polluted and restricted illumination conditions, achieving pose estimation by vision is a great challenge. This paper proposes a line-features-based pose estimation method for the disc cutter holder of the shield machine by using a monocular camera. For the blurring effect of rounded corners on the image edge, a rounded edge model is established to obtain edge points that better match the 3D model of the workpiece. To obtain the edge search box corresponding to each edge, a contour separation method based on an adaptive threshold region growing method is proposed. By preprocesses on the edge points of each edge, the efficiency and the accuracy of RANSAC linear fitting are improved. The experimental result shows that the proposed pose estimation method is highly reliable and can meet the measurement accuracy requirements in practical engineering applications.

Pose Determination of the Disc Cutter Holder of Shield Machine Based on Monocular Vision.

The visual measurement system plays a vital role in the disc cutter changing robot of the shield machine, and its accuracy directly determines the success rate of the disc cutter grasping. However, the actual industrial environment with strong noise brings a great challenge to the pose measurement methods. The existing methods are difficult to meet the required accuracy of pose measurement based on machine vision under the disc cutter changing conditions. To solve this problem, we propose a monocular visual pose measurement method consisting of the high precision optimal solution to the PnP problem (OPnP) method and the highly robust distance matching (DM) method. First, the OPnP method is used to calculate the rough pose of the shield machine's cutter holder, and then the DM method is used to measure its pose accurately. Simulation results show that the proposed monocular measurement method has better accuracy and robustness than the several mainstream PnP methods. The experimental results also show that the maximum error of the proposed method is 0.28° in the direction of rotation and 0.32 mm in the direction of translation, which can meet the measurement accuracy requirement of the vision system of the disc cutter changing robot in practical engineering application.

Adaptive-Neuro-Fuzzy-Based Information Fusion for the Attitude Prediction of TBMs.

In a tunneling boring machine (TBM), to obtain the attitude in real time is very important for a driver. However, the current laser targeting system has a large delay before obtaining the attitude. So, an adaptive-neuro-fuzzy-based information fusion method is proposed to predict the attitude of a laser targeting system in real time. In the proposed method, a dual-rate information fusion is used to fuse the information of a laser targeting system and a two-axis inclinometer, and then obtain roll and pitch angles with a higher rate and provide a smoother attitude prediction. Considering that a measurement error exists, the adaptive neuro-fuzzy inference system (ANFIS) is proposed to model the measurement error, and then the ANFIS-based model is combined with the dual-rate information fusion to achieve high performance. Experimental results show the ANFIS-based information fusion can provide higher real-time performance and accuracy of the attitude prediction. Experimental results also verify that the ANFIS-based information fusion can solve the problem of the laser targeting system losing signals.

BMI1 and MEL18 Promote Colitis-Associated Cancer in Mice via REG3B and STAT3.

BACKGROUND & AIMS: Polycomb group proteins are epigenetic factors that silence gene expression; they are dysregulated in cancer cells and contribute to carcinogenesis by unclear mechanisms. We investigated whether BMI1 proto-oncogene, polycomb ring finger (BMI1), and polycomb group ring finger 2 (PCGF2, also called MEL18) are involved in the initiation and progression of colitis-associated cancer (CAC) in mice. METHODS: We generated mice containing floxed alleles of Bmi1 and/or Mel18 and/or Reg3b using the villin-Cre promoter (called Bmi1ΔIEC, Mel18ΔIEC, DKO, and TKO mice). We also disrupted Bmi1 and/or Mel18 specifically in intestinal epithelial cells (IECs) using the villin-CreERT2-inducible promoter. CAC was induced in cre-negative littermate mice (control) and mice with conditional disruption of Bmi1 and/or Mel18 by intraperitoneal injection of azoxymethane (AOM) followed by addition of dextran sulfate sodium (DSS) to drinking water. Colon tissues were collected from mice and analyzed by histology and immunoblots; IECs were isolated and used in cDNA microarray analyses. RESULTS: Following administration of AOM and DSS, DKO mice developed significantly fewer polyps than control, Bmi1ΔIEC, Mel18ΔIEC, Reg3bΔIEC, or TKO mice. Adenomas in the colons of DKO mice were low-grade dysplasias, whereas adenomas in control, Bmi1ΔIEC, Mel18ΔIEC, Reg3bΔIEC, or TKO mice were high-grade dysplasias with aggressive invasion of the muscularis mucosa. Disruption of Bmi1 and Mel18 (DKO mice) during late stages of carcinogenesis significantly reduced the numbers of large adenomas and the load of total adenomas, reduced proliferation, and increased apoptosis in colon tissues. IECs isolated from DKO mice after AOM and DSS administration had increased expression of Reg3b compared with control, Bmi1ΔIEC, or Mel18ΔIEC mice. Expression of REG3B was sufficient to inhibit cytokine-induced activation of STAT3 in IECs. The human REG3ß protein, the functional counterpart of mouse REG3B, inhibited STAT3 activity in human 293T cells, and its expression level in colorectal tumors correlated inversely with pSTAT3 level and survival times of patients. CONCLUSIONS: BMI1 and MEL18 contribute to the development of CAC in mice by promoting proliferation and reducing apoptosis via suppressing expression of Reg3b. REG3B negatively regulates cytokine-induced activation of STAT3 in colon epithelial cells. This pathway might be targeted in patients with colitis to reduce carcinogenesis.

The plant-specific actin binding protein SCAB1 stabilizes actin filaments and regulates stomatal movement in Arabidopsis.

Microfilament dynamics play a critical role in regulating stomatal movement; however, the molecular mechanism underlying this process is not well understood. We report here the identification and characterization of STOMATAL CLOSURE-RELATED ACTIN BINDING PROTEIN1 (SCAB1), an Arabidopsis thaliana actin binding protein. Plants lacking SCAB1 were hypersensitive to drought stress and exhibited reduced abscisic acid-, H(2)O(2)-, and CaCl(2)-regulated stomatal movement. In vitro and in vivo analyses revealed that SCAB1 binds, stabilizes, and bundles actin filaments. SCAB1 shares sequence similarity only with plant proteins and contains a previously undiscovered actin binding domain. During stomatal closure, actin filaments switched from a radial orientation in open stomata to a longitudinal orientation in closed stomata. This switch took longer in scab1 plants than in wild-type plants and was correlated with the delay in stomatal closure seen in scab1 mutants in response to drought stress. Our results suggest that SCAB1 is required for the precise regulation of actin filament reorganization during stomatal closure.

Villification of the intestinal epithelium is driven by Foxl1.

The primitive gut tube of mammals initially forms as a simple cylinder consisting of the endoderm-derived, pseudostratified epithelium and the mesoderm-derived surrounding mesenchyme. During mid-gestation a dramatic transformation occurs in which the epithelium is both restructured into its final cuboidal form and simultaneously folded and refolded to create intestinal villi and intervillus regions, the incipient crypts. Here we show that the mesenchymal winged helix transcription factor Foxl1, itself induced by epithelial hedgehog signaling, controls villification by activating BMP and PDGFRα as well as planar cell polarity genes in epithelial-adjacent telocyte progenitors, both directly and in a feed-forward loop with Foxo3.

103 W in-band dual-end-pumped Ho:YAG laser.

An efficient 2 µm in-band pumped Ho:YAG laser was demonstrated. The resonator involves two Ho:YAG crystals, each of which was dual-end-pumped by two orthogonally polarized diode-pumped Tm:YLF lasers. The maximum continuous wave output power of 103 W was achieved, corresponding to a slope efficiency of 67.8% with respect to the incident pump power and an optical-to-optical conversion efficiency of 63.5%. Under Q-switched mode, we obtained 101 W laser output at 30 kHz, corresponding to a slope efficiency of 66.2%. The beam quality or M2 factor was found to be less than 2.

PCR and magnetic bead-mediated target capture for the isolation of short interspersed nucleotide elements in fishes.

Short interspersed nucleotide elements (SINEs), a type of retrotransposon, are widely distributed in various genomes with multiple copies arranged in different orientations, and cause changes to genes and genomes during evolutionary history. This can provide the basis for determining genome diversity, genetic variation and molecular phylogeny, etc. SINE DNA is transcribed into RNA by polymerase III from an internal promoter, which is composed of two conserved boxes, box A and box B. Here we present an approach to isolate novel SINEs based on these promoter elements. Box A of a SINE is obtained via PCR with only one primer identical to box B (B-PCR). Box B and its downstream sequence are acquired by PCR with one primer corresponding to box A (A-PCR). The SINE clone produced by A-PCR is selected as a template to label a probe with biotin. The full-length SINEs are isolated from the genomic pool through complex capture using the biotinylated probe bound to magnetic particles. Using this approach, a novel SINE family, Cn-SINE, from the genomes of Coilia nasus, was isolated. The members are 180-360 bp long. Sequence homology suggests that Cn-SINEs evolved from a leucine tRNA gene. This is the first report of a tRNA(Leu)-related SINE obtained without the use of a genomic library or inverse PCR. These results provide new insights into the origin of SINEs.

Complete mitochondrial genome of Lepidotrigla alata (Osteichthyes: Triglidae) with phylogenetic consideration.

The complete mitochondrial genome of Lepidotrigla alata was sequenced in this study. The genome sequence is 16,512 bp in length, comprising 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and one control region. Overall base composition is 26.46% A, 25.05% T, 17.22% G, and 31.27% C. Phylogenetic analysis indicated that L. alata was close to L. guentheri and L. microptera, and each genus in the family Triglidae was monophyletic. This study can provide valuable information for future evolutionary studies on L. alata and Triglidae.

Optimized scheme for paired transverse corrective forces in S-shaped scoliosis via ultrasound and application in Chêneau brace: a pilot study.

BACKGROUND: There is currently no consensus on the optimal positions of the transverse corrective forces (TCFs) for scoliosis braces. OBJECTIVES: This study aimed to explore an optimal scheme of placing paired TCF for S-shaped adolescent idiopathic scoliosis and its feasibility in Chêneau brace (CB) treatment. STUDY DESIGN: Cross-over feasibility pilot trial. METHODS: Ten S-shaped adolescent idiopathic scoliosis participants were invited to receive four tests with different paired TCF positions under ultrasound. The positions of the paired TCF were test 1: thoracic apical vertebra (AV), lumbar AV; test 2: 2 cm inferior to thoracic AV, lumbar AV; test 3: thoracic AV, 2 cm superior to lumbar AV; and test 4: 2 cm inferior to thoracic AV, 2 cm superior to lumbar AV. The test scheme with the highest mean in-force correction rate (IFCR) for the thoracic spinous process angle (SPA) was further applied in the CB fabrication of 4 additional participants. RESULTS: A significant higher mean IFCR of the thoracic SPA of 63.6% was found in test 2 (P < 0.001), which also contributed to its higher overall IFCR of the SPA of 64.6% (P = 0.001). Moreover, the mean in-brace correction rates for the thoracic and overall curves in CB were 46.4% and 51.8%, respectively. No adverse events were reported. CONCLUSIONS: Placing paired TCF at the lumbar AV and 2 cm inferior to the thoracic AV achieved better treatment efficacy than other schemes. The practical application of this scheme on the CB was feasible.

MRISCs protect colonic stem cells from inflammatory damage.

Increasing evidence suggest functional roles of subepithelial mesenchymal niche cells in maintaining intestinal stem cells and in modulating the pathogenesis of various intestinal diseases in mammals. A recent study reported the discovery of a new population of stromal cells in mice termed MAP3K2-Regulated Intestinal Stromal Cells (MRISCs); these cells reside at the base of colonic crypt and function to protect colonic stem cells during colonic inflammation by expressing the Wnt agonist R-spondin1 (Rspo1).

The cellular niche for intestinal stem cells: a team effort.

The rapidly self-renewing epithelium in the mammalian intestine is maintained by multipotent intestinal stem cells (ISCs) located at the bottom of the intestinal crypt that are interspersed with Paneth cells in the small intestine and Paneth-like cells in the colon. The ISC compartment is also closely associated with a sub-epithelial compartment that contains multiple types of mesenchymal stromal cells. With the advances in single cell and gene editing technologies, rapid progress has been made for the identification and characterization of the cellular components of the niche microenvironment that is essential for self-renewal and differentiation of ISCs. It has become increasingly clear that a heterogeneous population of mesenchymal cells as well as the Paneth cells collectively provide multiple secreted niche signals to promote ISC self-renewal. Here we review and summarize recent advances in the regulation of ISCs with a main focus on the definition of niche cells that sustain ISCs.

A Comparative Transcriptional Landscape of Two Castor Cultivars Obtained by Single-Molecule Sequencing Comparative Analysis.

Background and Objectives: Castor (Ricinus communis L.) is an important non-edible oilseed crop. Lm-type female strains and normal amphiprotic strains are important castor cultivars, and are mainly different in their inflorescence structures and leaf shapes. To better understand the mechanisms underlying these differences at the molecular level, we performed a comparative transcriptional analysis. Materials and Methods: Full-length transcriptome sequencing and short-read RNA sequencing were employed. Results: A total of 76,068 and 44,223 non-redundant transcripts were obtained from high-quality transcripts of Lm-type female strains and normal amphiprotic strains, respectively. In Lm-type female strains and normal amphiprotic strains, 51,613 and 20,152 alternative splicing events were found, respectively. There were 13,239 transcription factors identified from the full-length transcriptomes. Comparative analysis showed a great variety of gene expression of common and unique transcription factors between the two cultivars. Meanwhile, a functional analysis of the isoforms was conducted. The full-length sequences were used as a reference genome, and a short-read RNA sequencing analysis was performed to conduct differential gene analysis. Furthermore, the function of DEGs were performed to annotation analysis. Conclusion: The results revealed considerable differences and expression diversity between the two cultivars, well beyond what was reported in previous studies and likely reflecting the differences in architecture between these two cultivars.

Robust internal model control of servo motor based on sliding mode control approach.

This paper proposes a robust internal model control (IMC) based on sliding mode control (SMC) approach for high-performance motion control of a servo motor subject to uncertainties and/or disturbances. The proposed control strategy considers not only the simplicity and intuition of the IMC-based controller for a prescribed tracking performance but also the effectiveness of the SMC scheme to guarantee the robustness of the servo system. Since the performance of the IMC-based controller can be analyzed via a SMC structure, a robust control law based on the SMC technique is introduced into the IMC scheme to decrease the sensitivity to uncertainties and enhance the resistance to disturbances. Moreover, the 2-degree-of-freedom IMC integrating the robust SMC scheme is developed to further improve the control performance. The stability is analyzed based on Lyapunov theory, and the theoretical results show that a prescribed transient tracking performance and a final tracking accuracy of the servo system can be guaranteed. Comparative simulations and experiments are investigated to verify the high performance nature of the proposed control strategy.

Reviewing Clinical Effectiveness of Active Training Strategies of Platform-Based Ankle Rehabilitation Robots.

Objective: This review aims to provide a systematical investigation of clinical effectiveness of active training strategies applied in platform-based ankle robots. Method: English-language studies published from Jan 1980 to Aug 2017 were searched from four databases using key words of "Ankle∗" AND "Robot∗" AND "Effect∗ OR Improv∗ OR Increas∗." Following an initial screening, three rounds of discrimination were successively conducted based on the title, the abstract, and the full paper. Result: A total of 21 studies were selected with 311 patients involved; of them, 13 studies applied a single group while another eight studies used different groups for comparison to verify the therapeutic effect. Virtual-reality (VR) game training was applied in 19 studies, while two studies used proprioceptive neuromuscular facilitation (PNF) training. Conclusion: Active training techniques delivered by platform ankle rehabilitation robots have been demonstrated with great potential for clinical applications. Training strategies are mostly combined with one another by considering rehabilitation schemes and motion ability of ankle joints. VR game environment has been commonly used with active ankle training. Bioelectrical signals integrated with VR game training can implement intelligent identification of movement intention and assessment. These further provide the foundation for advanced interactive training strategies that can lead to enhanced training safety and confidence for patients and better treatment efficacy.

A Feasibility Study of SSVEP-Based Passive Training on an Ankle Rehabilitation Robot.

OBJECTIVE: This study aims to establish a steady-state visual evoked potential- (SSVEP-) based passive training protocol on an ankle rehabilitation robot and validate its feasibility. METHOD: This paper combines SSVEP signals and the virtual reality circumstance through constructing information transmission loops between brains and ankle robots. The robot can judge motion intentions of subjects and trigger the training when subjects pay their attention on one of the four flickering circles. The virtual reality training circumstance provides real-time visual feedback of ankle rotation. RESULT: All five subjects succeeded in conducting ankle training based on the SSVEP-triggered training strategy following their motion intentions. The lowest success rate is 80%, and the highest one is 100%. The lowest information transfer rate (ITR) is 11.5 bits/min when the biggest one of the robots for this proposed training is set as 24 bits/min. CONCLUSION: The proposed training strategy is feasible and promising to be combined with a robot for ankle rehabilitation. Future work will focus on adopting more advanced data process techniques to improve the reliability of intention detection and investigating how patients respond to such a training strategy.

Identification of olfactory receptor genes in the Japanese grenadier anchovy Coilia nasus.

Olfaction is essential for fish to detect odorant elements in the environment and plays a critical role in navigating, locating food and detecting predators. Olfactory function is produced by the olfactory transduction pathway and is activated by olfactory receptors (ORs) through the binding of odorant elements. Recently, four types of olfactory receptors have been identified in vertebrate olfactory epithelium, including main odorant receptors (MORs), vomeronasal type receptors (VRs), trace-amine associated receptors (TAARs) and formyl peptide receptors (FPRs). It has been hypothesized that migratory fish, which have the ability to perform spawning migration, use olfactory cues to return to natal rivers. Therefore, obtaining OR genes from migratory fish will provide a resource for the study of molecular mechanisms that underlie fish spawning migration behaviors. Previous studies of OR genes have mainly focused on genomic data, however little information has been gained at the transcript level. In this study, we identified the OR genes of an economically important commercial fish Coilia nasus through searching for olfactory epithelium transcriptomes. A total of 142 candidate MOR, 52 V2R/OlfC, 32 TAAR and two FPR putative genes were identified. In addition, through genomic analysis we identified several MOR genes containing introns, which is unusual for vertebrate MOR genes. The transcriptome-scale mining strategy proved to be fruitful in identifying large sets of OR genes from species whose genome information is unavailable. Our findings lay the foundation for further research into the possible molecular mechanisms underlying the spawning migration behavior in C. nasus.

[An automatic 3D-locating couch for radiation therapy].

An intensity modulated method by scanning for the focusing therapy machine is introduced in this paper. At first, the 3-D model of the focus is delaminated through the treatment planning system, and the dose distributing of each lay is calculated by an inverse design method. Then, the exposure time of the focus at each position is determined and converted to a scanning parameter, such as position, speed and so on. Afterward, the focus continuously scans the tumor at different speeds along the planned track under the control of the computer. Consequently the point-by- point intensity modulation is achieved through the diversification of the scanning speed of the focus.

[Microdevice for the investigation of high-glucose induced lifespan and the protective effect of polydatin in C. elegans].

Caenorhabditis elegans (C. elegans) has been widely used as a model organism for biomedical research due to its sufficient homology with human at molecular or genomic level. In this work, we describe a microfluidic device not only to investigate the response of C. elegans including lifespan and oxidative stress, but also to evaluate the protective effect of polydatin induced by high-glucose condition. It was found that the mean lifespan of worms was significantly reduced and the oxidative stress protein GST-4 was increased in worms that are subjected to high glucose. However, a certain dose of polydatin could weaken the increased oxidative stress induced by high-glucose and extend the lifespan, indicating the protective effect of polydatin against the toxic of high-glucose. The established approach is simple to operate, easy for realtime imaging and multiparatemer evaluations in parallel, providing a potential platform for drug evaluation/screening in a high throughput format at single animal resolution.

Modeling type 2 diabetes-like hyperglycemia in C. elegans on a microdevice.

Caenorhabditis elegans (C. elegans) has been widely used as a model organism for biomedical research due to its sufficient homology with mammals at the molecular and genomic levels. In this work, we describe a microfluidic assay to model type 2 diabetes-like hyperglycemia in C. elegans to examine several aspects of this disease on a microdevice. The microdevice is characterized by the integration of long-term worm culture, worm immobilization, and precise chemical stimuli in a single device, thus enabling the multi-parameter analysis of individual worms at a single-animal resolution. With this device, the lifespan, oxidative stress responses, and lipid metabolism of individual worms in response to different glucose concentrations were characterized. It was found that the mean lifespan of worms was significantly reduced by as much as 29.0% and 30.8% in worms that were subjected to 100 mM and 200 mM glucose, respectively. The expression of oxidative stress protein gst-4 was increased, and the expression of hsp-70 (heat shock protein) and skn-1 (redox sensitive transcription factor) genes was down-regulated in worms treated with a high level of glucose. Moreover, fat storage was markedly increased in the bodies of VS29 worms (vha-6p::GFP::dgat-2) that were exposed to the high-glucose condition. The established approach is not only suitable for further elucidation of the mechanism of metabolic disorders involved in diabetes and its complications, but also facilitates the evaluation of anti-diabetic drugs in a high-throughput manner.