Vision-based Vehicle Navigation Using the Fluorescent Lamp Array on the Ceiling

In this paper, autonomous navigation based on a TV vision system on board a vehicle is proppsed. Our method is to use fluorescent lamp arrays on the ceiling as a lighthouse for vehicle motion. First, experimental study of vehicle control based on information from photo-sensors, set up on a TV screen, is worked out using an actual size model. Then, numerical simulations for this control scheme are carried out in detail. Moreover, a more vision-based approach is investigated which extracts information aspects from the images of fluorescent lamp arrays to realize more exact motion along the lamp array. Finally, a practical autonomous vehicle which is controlled by a photo-sensor system is constructed and its experimental results are shown

A Basic Study on Path Teaching Method for a Mobile Robot Using a Digital Camera

This paper proposes a novel path teaching method for a mobile robot. In this method an operator takes pictures at significant points such as turning points, half way points and a destination on robot´s path by a digital camera. Then, the operator teaches the robot landmarks to recognize the images and actions for the robot to take at the significant points. The robot travels autonomously searching the landmarks and obeys the instructions when it recognizes reaching the significant points. By using this method, it is possible to teach paths for the mobile robot more easily. In this paper, outline of the proposed method and results of fundamental experiments in both indoor and outdoor environment to confirm possibility of the method are described

Pulmonary venous occlusion and death in pulmonary arterial hypertension: survival analyses using radiographic surrogates

BACKGROUND: Recent studies find that a considerable number of patients with pulmonary arterial hypertension (PAH) develop fibrous obstruction of the pulmonary veins. Such obstruction more commonly accompanies connective tissue disorder (CTD)-associated PAH than idiopathic PAH. However, few researchers have gauged the risk of death involving obstruction of the pulmonary veins. METHODS: Thirty-seven patients with PAH were enrolled (18 patients, idiopathic PAH; 19 patients, CTD-associated PAH). The patients were 49 ± 18 years and had a World Health Organization functional class of 3.2 ± 0.6. Thickening of the interlobular septa, centrilobular ground-glass attenuation, and mediastinal adenopathy were surrogates for obstruction of the pulmonary veins, and were detected by a 16-row multidetector computed tomography scanner. RESULTS: The follow-up period was 714 ± 552 days. Fifteen deaths occurred. Thickening of the interlobular septa, centrilobular ground-glass attenuation, and mediastinal adenopathy were found in 37.8%, 24.3%, and 16.2% of patients, respectively. Cox proportional hazard analysis revealed an increased risk of death with each radiographic surrogate (mediastinal adenopathy: p < 0.0001, hazard ratio = 13.9; thickening of interlobular septa: p < 0.001, hazard ratio = 12.0; ground-glass attenuation: p = 0.02, hazard ratio = 3.7). The statistical significance of these relationships was independent of the cause of PAH and plasma concentration of brain natriuretic peptide. CONCLUSIONS: The results of this study imply that obstruction of the pulmonary veins is associated with an increased risk of death in patients with PAH

Inhibitory effects of adhesion oligopeptides on the invasion of squamous carcinoma cells with special reference to implication of αv integrins

金沢大学大学院医学系研究科保健学専攻We studied invasion-related adhesion events in vitro using three squamous carcinoma cell lines (HSC-3, poorly differentiated type; OSC-19, well-differentiated type; and KB cells, undifferentiated type). An in vitro invasion assay through matrigel in the transwell chamber revealed that HSC-3 cells were most invasive, OSC-19 cells moderately invasive and KB cells least invasive. Inhibition assay of invasion using synthetic peptides RGD, RGDV, RGDS, RGDT, IKVAV and YIGSR, showed that invasion of the three cell lines was significantly inhibited by RGDV. There were other peptides that inhibited invasion significantly including IKVAV for HSC-3, and RGDS and YIGSR for OSC-19. HSC-3 cells and OSC-19 cells adhered to fibronectin, laminin, vitronectin, and type IV collagen, and KB cells did not adhere to laminin but did to fibronectin, vitronectin and collagen type IV. Pretreatment of cells with RGDV peptide in the attachment assay reduced the ability of these cells to bind to vitronectin and fibronectin more efficiently than pretreatment with RGDS. Anti-αv antibodies inhibited adhesion of HSC-3, OSC-19 and KB cells to vitronectin, but anti-β1 antibodies did not inhibit adhesion. Immunofluorescent microscopic examinations showed that all cell lines were positive for anti-β5 and anti-αv antibodies, and only HSC-β3 cells were positive for antiβ-3 antibody. α5β1 was not clearly demonstrated in any of the cell lines. RGDV was the most effective inhibitor of squamous cell carcinoma invasion among the synthetic oligopeptides used in this experiment, and it is suggested that it affects αvβ3-and/or αvβ5-mediated carcinoma cell invasion

Optimization of the analogue-sensitive Cdc2/Cdk1 mutant by in vivo selection eliminates physiological limitations to its use in cell cycle analysis

Analogue-sensitive (as) mutants of kinases are widely used to selectively inhibit a single kinase with few off-target effects. The analogue-sensitive mutant cdc2-as of fission yeast (Schizosaccharomyces pombe) is a powerful tool to study the cell cycle, but the strain displays meiotic defects, and is sensitive to high and low temperature even in the absence of ATP-analogue inhibitors. This has limited the use of the strain for use in these settings. Here, we used in vivo selection for intragenic suppressor mutations of cdc2-as that restore full function in the absence of ATP-analogues. The cdc2-asM17 underwent meiosis and produced viable spores to a similar degree to the wild-type strain. The suppressor mutation also rescued the sensitivity of the cdc2-as strain to high and low temperature, genotoxins and an anti-microtubule drug. We have used cdc2-asM17 to show that Cdc2 activity is required to maintain the activity of the spindle assembly checkpoint. Furthermore, we also demonstrate that maintenance of the Shugoshin Sgo1 at meiotic centromeres does not require Cdc2 activity, whereas localization of the kinase aurora does. The modified cdc2-asM17 allele can be thus used to analyse many aspects of cell-cycle-related events in fission yeast

Oxidative stress induction of DJ-1 protein in reactive astrocytes scavenges free radicals and reduces cell injury

Astrocytes, one of the predominant types of glial cells, function as both supportive and metabolic cells for the brain. Under cerebral ischemia/reperfusion-induced oxidative conditions, astrocytes accumulate and activate in the ischemic region. DJ-1 has recently been shown to be a sensor of oxidative stress in living cells. However, the function of astrocytic DJ-1 is still unknown. In the present study, to clarify the effect of astrocytic DJ-1 protein under massive oxidative insult, we used a focal ischemic rat model that had been subjected to middle cerebral artery occlusion (MCAO) and reperfusion. We then investigated changes in the distribution of DJ-1 in astrocytes, DJ-1 release from cultured astrocytes, and the effects of recombinant DJ-1 protein on hydrogen peroxide (H2O2)-induced death in normal and DJ-1-knockdown SH-SY5Y cells and on in vitro scavenging of hydroxyl radicals (•OH) by electron spin resonance spectrometry. At 24 h after 2-h MCAO and reperfusion, an infarct lesion was markedly observed using magnetic resonance imaging and 2,3,5-triphenyltetrazolium chloride staining. In addition, reactive astrocytes enhanced DJ-1 expression in the penumbral zone of the ischemic core and that DJ-1 protein was extracellularly released from astrocytes by H2O2 in in vitro primary cultures. Although DJ-1-knockdown SH-SY5Y cells were markedly vulnerable to oxidative stress, treatment with glutathione S-transferase-tagged recombinant human DJ-1 protein (GST-DJ-1) significantly inhibited H2O2-induced cell death. In addition, GST-DJ-1 protein directly scavenged •OH. These results suggest that oxidative stress induces the release of astrocytic DJ-1 protein, which may contribute to astrocyte-mediated neuroprotection

Preparatory acoustic emission activity of hydraulic fracture in granite with various viscous fluids revealed by deep learning technique

To investigate the influence of fluid viscosity on the fracturing process, we conducted hydraulic fracturing experiments on Kurokami-jima granite specimens with resins of various viscosities. We monitored the acoustic emission (AE) activity during fracturing and estimated the moment tensor (MT) solutions for 54 727 AE events using a deep learning technique. We observed the breakdown at 14–22 MPa of borehole pressure, which was dependent on the viscosity, as well as two preparatory phases accompanying the expansion of AE-active regions. The first expansion phase typically began at 10–30 per cent of the breakdown pressure, where AEs occurred three-dimensionally surrounding the wellbore and their active region expanded with time towards the external boundaries of the specimen. The MT solutions of these AEs corresponded to crack-opening (tensile) events in various orientations. The second expansion phase began at 90–99 per cent of the breakdown pressure. During this phase, a new planar AE distribution emerged from the borehole and expanded along the maximum compression axis, and the focal mechanisms of these AEs corresponded to the tensile events on the AE-delineating plane. We interpreted that the first phase was induced by fluid penetration into pre-existing microcracks, such as grain boundaries, and the second phase corresponded to the main fracture formation. Significant dependences on fluid viscosity were observed in the borehole pressure at the time of main fracture initiation and in the speed of the fracture propagation in the second phase. The AE activity observed in the present study was fairly complex compared to that observed in previous experiments conducted on tight shale samples. This difference indicates the importance of the interaction between the fracturing fluid and pre-existing microcracks in the fracturing process

IMAGING OF AVASCULAR NECROSIS OF FEMORAL HEAD IN SPONTANEOUS HYPERTENSIVE RATS AND ITS EXPERIMENTAL MODEL

科学研究費補助金研究成果報告書研究種目: 基盤研究(C)研究期間: 1997～2000課題番号: 09670927研究代表者: 高田 政彦（滋賀医科大学・医学部・講師）研究分担者: 森川 茂廣（滋賀医科大学・分子神経科学研究センター・助教授）研究分担者: 山本 逸雄（滋賀医科大学・医学部・助教授