58 research outputs found

    MULTI-AGV SCHEDULING OPTIMIZATION BASED ON NEURO-ENDOCRINE COORDINATION MECHANISM 

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    Ovaj se završni radi bavi mobilnim robotima koji su pokretani nogama. Rad se sastoji od dvije veće cjeline. Prvi dio rada donosi literaturni pregled mobilnih robota pokretanih nogama te daje njihovu podjelu. Mobilne robote pokretane nogama najčešće dijelimo prema broju nogu, ali i po ostalim fizičkim karakteristikama. U radu se govori o osnovnim prednostima i nedostacima pri konstruiranju i upravljanju ovakvih robota. Većina takvih robota izrađena je po uzoru na neku životinju ili čovjeka, odnosno imitirajući prirodu. Takav pristup proučavanja i preslikavanja životinjskih karakteristika u tehničke sustave naziva se biomimikrija. Biomimikrija je očita i u drugom dijelu rada koji se bavi adaptacijom već postojeće robotske platforme. U drugom dijelu rada se razrađuje prilagodba četveronožnog paukolikog robota za novoodabrano elektroničko sklopovlje. Nakon modeliranja konstrukcije u programskom paketu CATIA, izrađen je prototip na uređaju za brzu izradu prototipova. Posebnost ove platforme jest da se svi aktuatori nalaze unutar samog tijela robota, a ne u nogama. Na taj se način eliminira prekomjerna masa nogu. Svaka od ĉetiri noge se pokreće pomoću polužnog mehanizma koji se sastoji od četiri štapa. Zbog te karakteristike javlja se neuobičajena kinematika robota. Ovakvom konstrukcijom robot postaje izazovna platforma za proučavanje algoritama umjetne inteligencije koji se implemetiraju za ostvarivanje gibanja. Takvi algoritmi daju puno bolje rezultate od sekvencijalnog programiranja kod složenijih robotskih struktura.This final project addresses the issue of legged mobile robots. The paper consists of two major parts. First part of the paper brings literature review of legged mobile robots and classifies them. Legged mobile robots most commonly differ by the number of their legs, but they can be distinguished by many other physical characteristics. The paper tackles elementary advantages and disadvantages when designing and controlling this type of a robot. Most legged mobile robots are made by imitating animals and humans. This approach of implementing knowledge obtained form observing nature into technical systems is called biomimetics. Biomimetics is also obvious in the second part of this paper. The second part of the paper elaborates adaptation of already existing quadruped robotic platform for the new electronic circuitry. After 3D designing the model in the CATIA software, prototype is printed on the rapid prototyping printer. This platform is unique because all the actuators are located in the body of the robot, and none of them is in the robot's leggs. Specifically, each of the four legs is controlled by separete four-bar linkage mechanism. Consequently, robot's mass is reduced, however, complexity of control is increased. This design causes unconventional kinematics, thus providing challenging platform for gait-learning algorithms. These algorithms excel in complicated structures like this, where sequential programming tends to underperform

    Transcriptional and Functional Analysis of the Effects of Magnolol: Inhibition of Autolysis and Biofilms in Staphylococcus aureus

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    BACKGROUND: The targeting of Staphylococcus aureus biofilm structures are now gaining interest as an alternative strategy for developing new types of antimicrobial agents. Magnolol (MOL) shows inhibitory activity against S. aureus biofilms and Triton X-100-induced autolysis in vitro, although there are no data regarding the molecular mechanisms of MOL action in bacteria. METHODOLOGY/PRINCIPAL FINDINGS: The molecular basis of the markedly reduced autolytic phenotype and biofilm inhibition triggered by MOL were explored using transcriptomic analysis, and the transcription of important genes were verified by real-time RT-PCR. The inhibition of autolysis by MOL was evaluated using quantitative bacteriolytic assays and zymographic analysis, and antibiofilm activity assays and confocal laser scanning microscopy were used to elucidate the inhibition of biofilm formation caused by MOL in 20 clinical isolates or standard strains. The reduction in cidA, atl, sle1, and lytN transcript levels following MOL treatment was consistent with the induced expression of their autolytic repressors lrgA, lrgB, arlR, and sarA. MOL generally inhibited or reversed the expression of most of the genes involved in biofilm production. The growth of S. aureus strain ATCC 25923 in the presence of MOL dose-dependently led to decreases in Triton X-100-induced autolysis, extracellular murein hydrolase activity, and the amount of extracellular DNA (eDNA). MOL may impede biofilm formation by reducing the expression of cidA, a murein hydrolase regulator, to inhibit autolysis and eDNA release, or MOL may directly repress biofilm formation. CONCLUSIONS/SIGNIFICANCE: MOL shows in vitro antimicrobial activity against clinical and standard S. aureus strains grown in planktonic and biofilm cultures, suggesting that the structure of MOL may potentially be used as a basis for the development of drugs targeting biofilms

    Molecular structure of the largemouth bass (Micropterus salmoides) Myf5 gene and its effect on skeletal muscle growth

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    Myogenic Regulatory Factors (MRFs), a family of basic helix-loop-helix (bHLH) transcription factors, play important roles in regulating skeletal muscle development and growth. Myf5, the primary factor of MRFs, initiates myogenesis. Its expression pattern during somitomyogenesis in some fish has been revealed. To further study its effect on fish muscle during postembryonic growth, characterization and function analysis of myf5 cDNA were carried out in largemouth bass. The 1,093 bp cDNA sequence was identified by RT-PCR and 3′RACE, then the ORF of Myf5 cDNA was cloned into the expression vector pcDNA3.1(−)/mycHisB. The recombinant plasmid pcDNA3.1(−)/mycHisB-Myf5 was injected into the dorsal muscle of tilapias. RT-PCR and histochemical results showed that the exogenous gene was transcribed and translated in vivo. Its effect on muscle growth focused on myofiber hypertrophy in white muscle 60 days post injection. This indicated that overexpression of Myf5 can promote myogenesis during the fish muscle postembryonic growth period

    Draft genome sequence of the Tibetan antelope

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    The Tibetan antelope (Pantholops hodgsonii) is endemic to the extremely inhospitable high-altitude environment of the Qinghai-Tibetan Plateau, a region that has a low partial pressure of oxygen and high ultraviolet radiation. Here we generate a draft genome of this artiodactyl and use it to detect the potential genetic bases of highland adaptation. Compared with other plain-dwelling mammals, the genome of the Tibetan antelope shows signals of adaptive evolution and gene-family expansion in genes associated with energy metabolism and oxygen transmission. Both the highland American pika, and the Tibetan antelope have signals of positive selection for genes involved in DNA repair and the production of ATPase. Genes associated with hypoxia seem to have experienced convergent evolution. Thus, our study suggests that common genetic mechanisms might have been utilized to enable high-altitude adaptation

    A consensus genome of sika deer (Cervus nippon) and transcriptome analysis provided novel insights on the regulation mechanism of transcript factor in antler development

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    Abstract Background Sika deer (Cervus nippon) holds significance among cervids, with three genomes recently published. However, these genomes still contain hundreds of gaps and display significant discrepancies in continuity and accuracy. This poses challenges to functional genomics research and the selection of an appropriate reference genome. Thus, obtaining a high-quality reference genome is imperative to delve into functional genomics effectively. Findings Here we report a high-quality consensus genome of male sika deer. All 34 chromosomes are assembled into single-contig pseudomolecules without any gaps, which is the most complete assembly. The genome size is 2.7G with 23,284 protein-coding genes. Comparative genomics analysis found that the genomes of sika deer and red deer are highly conserved, an approximately 2.4G collinear regions with up to 99% sequence similarity. Meanwhile, we observed the fusion of red deer's Chr23 and Chr4 during evolution, forming sika deer's Chr1. Additionally, we identified 607 transcription factors (TFs) that are involved in the regulation of antler development, including RUNX2, SOX6, SOX8, SOX9, PAX8, SIX2, SIX4, SIX6, SPI1, NFAC1, KLHL8, ZN710, JDP2, and TWST2, based on this consensus reference genome. Conclusions Our results indicated that we acquired a high-quality consensus reference genome. That provided valuable resources for understanding functional genomics. In addition, discovered the genetic basis of sika-red hybrid fertility and identified 607 significant TFs that impact antler development

    Salvia castanea Hairy Roots are More Tolerant to Phosphate Deficiency than Salvia miltiorrhiza Hairy Roots Based on the Secondary Metabolism and Antioxidant Defenses

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    Salvia miltiorrhiza is a well-known traditional Chinese herb which is used to treat heart disease. Salvia castanea is a substitute product for S. miltiorrhiza in the medicinal field. Previous study has shown that phosphate (Pi) deficiency could promote the accumulation of secondary metabolism in herbs, and it has also developed a strategy for saving Pi resources and increasing the yield of active substances in herbs. In the present study, the hairy roots of S. miltiorrhiza and S. castanea were used to identify the Pi deficiency response mechanisms of these two Salvia species. The results showed that Pi deficiency increased the accumulation of specifically secondary metabolites, such as phenolic acids and tanshinones, which were caused by promoting the expression levels of key enzyme genes. In addition, Pi deficiency promoted the antioxidant activity in these two Salvia species. The data demonstrated that Pi deficiency increased the quality of the medicinal material in the plant. The hairy roots of S. castanea were more adaptive to Pi deficiency than those of S. miltiorrhiza in terms of biomass, secondary metabolism, and antioxidant activity. The results of this study provide insights into breeding herbs that are better adapted to Pi deficiency, which could increase the yield of active ingredients in herbs and save Pi resources

    SSANet: An Adaptive Spectral–Spatial Attention Autoencoder Network for Hyperspectral Unmixing

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    Convolutional neural-network-based autoencoders, which can integrate the spatial correlation between pixels well, have been broadly used for hyperspectral unmixing and obtained excellent performance. Nevertheless, these methods are hindered in their performance by the fact that they treat all spectral bands and spatial information equally in the unmixing procedure. In this article, we propose an adaptive spectral–spatial attention autoencoder network, called SSANet, to solve the mixing pixel problem of the hyperspectral image. First, we design an adaptive spectral–spatial attention module, which refines spectral–spatial features by sequentially superimposing the spectral attention module and spatial attention module. The spectral attention module is built to select useful spectral bands, and the spatial attention module is designed to filter spatial information. Second, SSANet exploits the geometric properties of endmembers in the hyperspectral image while considering abundance sparsity. We significantly improve the endmember and abundance results by introducing minimum volume and sparsity regularization terms into the loss function. We evaluate the proposed SSANet on one synthetic dataset and four real hyperspectral scenes, i.e., Samson, Jasper Ridge, Houston, and Urban. The results indicate that the proposed SSANet achieved competitive unmixing results compared with several conventional and advanced unmixing approaches with respect to the root mean square error and spectral angle distance
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