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Showing papers by "Utsunomiya University published in 2015"


Journal ArticleDOI
TL;DR: In this paper, a review of the atomic physics of the highly-charged ions relevant to EUV emission at these wavelengths is presented, which considers the developments that have contributed to the realization of the 5% conversion efficiency at 13.5 nm which underpins the production of high-volume lithography tools, and those that will be required to realize BEUV lithography.
Abstract: The primary requirement for the development of tools for extreme ultraviolet lithography (EUVL) has been the identification and optimization of suitable sources. These sources must be capable of producing hundreds of watts of extreme ultraviolet (EUV) radiation within a wavelength bandwidth of 2% centred on 13.5 nm, based on the availability of Mo/Si multilayer mirrors (MLMs) with a reflectivity of ~70% at this wavelength. Since, with the exception of large scale facilities, such as free electron lasers, such radiation is only emitted from plasmas containing moderately to highly charged ions, the source development prompted a large volume of studies of laser produced and discharge plasmas in order to identify which ions were the strongest emitters at this wavelength and the plasma conditions under which their emission was optimized. It quickly emerged that transitions of the type 4p64dn − 4p54dn+1 + 4dn−14f in the spectra of Sn IX to SnXIV were the best candidates and work is still ongoing to establish the plasma conditions under which their emission at 13.5 nm is maximized. In addition, development of other sources at 6.X nm, where X ~ 0.7, has been identified as the wavelength of choice for so-called Beyond EUVL (BEUVL), based on the availability of La/B based MLMs, with theoretical reflectance approaching 80% at this wavelength. Laser produced plasmas of Gd and Tb have been identified as potential source elements, as n = 4 − n = 4 transitions in their ions emit strongly near this wavelength. However to date, the highest conversion efficiency (CE) obtained, for laser to BEUV energy emitted within the 0.6% wavelength bandwidth of the available mirrors is only 0.8%, compared with values of 5% for the 2% bandwidth relevant for the Mo/Si mirrors at 13.5 nm. This suggests a need to identify other potential sources or the selection of other wavelengths for BEUVL. This review deals with the atomic physics of the highly-charged ions relevant to EUV emission at these wavelengths. It considers the developments that have contributed to the realization of the 5% CE at 13.5 nm which underpins the production of high-volume lithography tools, and those that will be required to realize BEUV lithography.

92 citations


Journal ArticleDOI
TL;DR: The present study demonstrated that the difference in strigolactone composition has no appreciable impact on AM symbiosis, at least in the two maize cultivars, and suggests that the traits involved in Striga-resistance are not necessarily accompanied by reduction in compatibility to AM fungi.
Abstract: Summary Strigolactones released from plant roots trigger both seed germination of parasitic weeds such as Striga spp. and hyphal branching of the symbionts arbuscular mycorrhizal (AM) fungi. Generally, strigolactone composition in exudates is quantitatively and qualitatively different among plants, which may be involved in susceptibility and host specificity in the parasite–plant interactions. We hypothesized that difference in strigolactone composition would have a significant impact on compatibility and host specificity/preference in AM symbiosis. Strigolactones in root exudates of Striga-susceptible (Pioneer 3253) and -resistant (KST 94) maize (Zea mays) cultivars were characterized by LC-MS/MS combined with germination assay using Striga hermonthica seeds. Levels of colonization and community compositions of AM fungi in the two cultivars were investigated in field and glasshouse experiments. 5-Deoxystrigol was exuded exclusively by the susceptible cultivar, while the resistant cultivar mainly exuded sorgomol. Despite the distinctive difference in strigolactone composition, the levels of AM colonization and the community compositions were not different between the cultivars. The present study demonstrated that the difference in strigolactone composition has no appreciable impact on AM symbiosis, at least in the two maize cultivars, and further suggests that the traits involved in Striga-resistance are not necessarily accompanied by reduction in compatibility to AM fungi.

76 citations


Journal ArticleDOI
TL;DR: Improved intracellular penetration of mitochondria-targeted complexes significantly enhanced gene transfer efficiency and delineate a simple and effective peptide-based method, as a starting point for the development of more sophisticated plant mitochondrial transfection strategies.
Abstract: Available methods in plant genetic transformation are nuclear and plastid transformations because similar procedures have not yet been established for the mitochondria. The double membrane and small size of the organelle, in addition to its large population in cells, are major obstacles in mitochondrial transfection. Here we report the intracellular delivery of exogenous DNA localized to the mitochondria of Arabidopsis thaliana using a combination of mitochondria-targeting peptide and cell-penetrating peptide. Low concentrations of peptides were sufficient to deliver DNA into the mitochondria and expression of imported DNA reached detectable levels within a short incubation period (12 h). We found that electrostatic interaction with the cell membrane is not a critical factor for complex internalization, instead, improved intracellular penetration of mitochondria-targeted complexes significantly enhanced gene transfer efficiency. Our results delineate a simple and effective peptide-based method, as a starting point for the development of more sophisticated plant mitochondrial transfection strategies.

72 citations


Journal ArticleDOI
TL;DR: It is demonstrated that although a gonad can develop into a complete testis in the absence of GsDF, Gsdf function is critical for directing the bipotential gonad at early developmental stages and is an endogenous inducer of testicular development similar to a master sex-determining gene.

69 citations


Journal ArticleDOI
TL;DR: In this paper, an adaptive sampling clock is generated by dual terahertz-comb-referenced spectrum analysers and is used for a timing clock signal in a data acquisition board.
Abstract: Terahertz (THz) dual comb spectroscopy (DCS) is a promising method for high-accuracy, high-resolution, broadband THz spectroscopy because the mode-resolved THz comb spectrum includes both broadband THz radiation and narrow-line CW-THz radiation characteristics. In addition, all frequency modes of a THz comb can be phase-locked to a microwave frequency standard, providing excellent traceability. However, the need for stabilization of dual femtosecond lasers has often hindered its wide use. To overcome this limitation, here we have demonstrated adaptive-sampling THz-DCS, allowing the use of free-running femtosecond lasers. To correct the fluctuation of the time and frequency scales caused by the laser timing jitter, an adaptive sampling clock is generated by dual THz-comb-referenced spectrum analysers and is used for a timing clock signal in a data acquisition board. The results not only indicated the successful implementation of THz-DCS with free-running lasers but also showed that this configuration outperforms standard THz-DCS with stabilized lasers due to the slight jitter remained in the stabilized lasers.

66 citations


Journal ArticleDOI
TL;DR: In this paper, a new equation modified from the Commission Internationale de l'Eclairage Unified Glare Rating formula using the effective glare luminance showed a strong correlation with the scaling results.
Abstract: Quantitative relations between discomfort glare evaluation and photometric quantities such as illuminance at the observer’s eye, average luminance of the source area, average luminance of the effective area and effective glare luminance for white LED sources having a variety of spatial luminance distributions have been investigated. Effective glare luminance, which is the sum of luminances in the luminaire area divided by the effective area, explains the scaling results of all sources in the same way. In addition, a new equation modified from the Commission Internationale de l'Eclairage Unified Glare Rating formula using the effective glare luminance showed a strong correlation with the scaling results. It is thus suggested that effective glare luminance is a useful index of discomfort glare for light sources having different spatial luminance distributions.

64 citations


Journal ArticleDOI
TL;DR: A fast, inexpensive, and easy method to purify viral dsRNAs using a micro-spin column method based on a dsRNA isolation protocol using cellulose powder, which will be useful to rapidly screen tissues for viral genomic and subgenomic ds RNAs.
Abstract: The occurrence of high-molecular-weight double-stranded RNA (dsRNA) is a hallmark of RNA virus infection in plants and fungi; thus, dsRNA profiling is an attractive tool for preliminary diagnosis or characterization of novel RNA viruses. Here, we report a fast, inexpensive, and easy method to purify viral dsRNAs using a micro-spin column method based on a dsRNA isolation protocol using cellulose powder. The dsRNAs can be purified in 1 h and does not require a particular type or source of dsRNA. This method will be useful to rapidly screen tissues for viral genomic and subgenomic dsRNAs.

51 citations


Journal ArticleDOI
TL;DR: In this paper, the authors proposed a new ultra-precision magnetic abrasive finishing (MAF) process using low frequency alternating magnetic field in this paper, which is considered to be able to efficiently apply in ultraprecision finishing of plane and complicated micro-surfaces.

48 citations


Journal ArticleDOI
TL;DR: This paper aims to demonstrate the efforts towards in-situ applicability of EMMARM, which aims to provide real-time information about the concrete mechanical properties of EMTs and their applications in the environment.
Abstract: 1 Center for Bioscience Research and Education, Utsunomiya University, 350 Mine-machi, Utsunomiya 321–8505, Japan 2 Department of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1–1 Gakuen-cho, Nakaku, Sakai, Osaka 599–8531, Japan 3 Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1–1–1 Yayoi, Bunkyo-ku, Tokyo 113–8657, Japan

47 citations


Journal ArticleDOI
TL;DR: To antagonize the developmental process initiated by Rhodococcus fascians and in response to the bacterial cytokinins, Arabidopsis activates its strigolactone response, partially suppressing shoot branching in the rosette.
Abstract: Leafy gall syndrome is the consequence of modified plant development in response to a mixture of cytokinins secreted by the biotrophic actinomycete Rhodococcus fascians. The similarity of the induced symptoms with the phenotype of plant mutants defective in strigolactone biosynthesis and signalling prompted an evaluation of the involvement of strigolactones in this pathology. All tested strigolactone-related Arabidopsis thaliana mutants were hypersensitive to R. fascians. Moreover, treatment with the synthetic strigolactone mixture GR24 and with the carotenoid cleavage dioxygenase inhibitor D2 illustrated that strigolactones acted as antagonistic compounds that restricted the morphogenic activity of R. fascians. Transcript profiling of the MORE AXILLARY GROWTH1 (MAX1), MAX2, MAX3, MAX4, and BRANCHED1 (BRC1) genes in the wild-type Columbia-0 accession and in different mutant backgrounds revealed that upregulation of strigolactone biosynthesis genes was triggered indirectly by the bacterial cytokinins via host-derived auxin and led to the activation of BRC1 expression, inhibiting the outgrowth of the newly developing shoots, a typical hallmark of leafy gall syndrome. Taken together, these data support the emerging insight that balances are critical for optimal leafy gall development: the long-lasting biotrophic interaction is possible only because the host activates a set of countermeasures—including the strigolactone response—in reaction to bacterial cytokinins to constrain the activity of R. fascians.

45 citations


Journal ArticleDOI
TL;DR: It is demonstrated that unlike embryonic/larval retinal regeneration, adult newt RPE cells are not directly reprogrammed into retinal stem/progenitor cells; instead, they are programmed into a unique state of multipotency that is similar to the early optic vesicle (embryo) but preserves certain adult characteristics.
Abstract: The reprogramming of retinal pigment epithelium (RPE) cells in the adult newt immediately after retinal injury is an area of active research for the study of retinal disorders and regeneration. We demonstrate here that unlike embryonic/larval retinal regeneration, adult newt RPE cells are not directly reprogrammed into retinal stem/progenitor cells; instead, they are programmed into a unique state of multipotency that is similar to the early optic vesicle (embryo) but preserves certain adult characteristics. These cells then differentiate into two populations from which the prospective-neural retina and -RPE layers are formed with the correct polarity. Furthermore, our findings provide insight into the similarity between these unique multipotent cells in newts and those implicated in retinal disorders, such as proliferative vitreoretinopathy, in humans. These findings provide a foundation for biomedical approaches that aim to induce retinal self-regeneration for the treatment of RPE-mediated retinal disorders.

Journal ArticleDOI
TL;DR: Three-dimensional mapping of fluorescent nanoparticles was performed by using incoherent digital holography and it was found that the axial magnification was constant whereas the lateral magnification linearly depended on theAxial position of the fluorescent nanoparticle.
Abstract: Three-dimensional mapping of fluorescent nanoparticles was performed by using incoherent digital holography. The positions of the nanoparticles were quantitatively determined by using Gaussian fitting of the axial- and lateral-diffraction distributions through position calibration from the observation space to the sample space. It was found that the axial magnification was constant whereas the lateral magnification linearly depended on the axial position of the fluorescent nanoparticles. The mapping of multiple fluorescent nanoparticles fixed in gelatin and a single fluorescent nanoparticle manipulated with optical tweezers in water were demonstrated.

Journal ArticleDOI
TL;DR: An AgarTrap-mediated transformation method using intact gemmae/gemmalings produced by asexual reproduction is developed, which will be useful in promoting studies of the molecular biology of M. polymorpha.
Abstract: The dioecious liverwort, Marchantia polymorpha L., is an emerging model plant. Various molecular biological techniques have been optimized for M. polymorpha for the past several years, and recently we reported a simplified Agrobacterium-mediated transformation method using sporelings (immature thalli from spores) of M. polymorpha. This method, termed AgarTrap (Agar-utilized Transformation with Pouring Solutions), completed by exchanging appropriate solutions on a single Petri dish to produce a sufficient number of independent transgenic sporelings. However, because spores are produced by crosses between males and females, the genetic backgrounds of resulting transgenic sporelings are not uniform. To easily produce transgenic liverworts with a uniform genetic background using AgarTrap, we developed an AgarTrap-mediated transformation method using intact gemmae/gemmalings produced by asexual reproduction. Using AgarTrap with male and female gemmae/gemmalings produced a sufficient number of independent transgenic gemmalings with uniform genetic backgrounds. The optimized transformation efficiencies were approximately 30 and 50 % in males and females, respectively. As with AgarTrap using sporelings, AgarTrap using intact gemmae/gemmalings will be useful in promoting studies of the molecular biology of M. polymorpha.

Journal ArticleDOI
TL;DR: In this article, a steam reforming reaction of a biogas mixture was conducted with a hydrogen permeable palladium-silver membrane reactor at lower temperatures from 623 to 723 K and from 0.1 to 0.4 MPa of reaction side pressure.

Proceedings ArticleDOI
17 Dec 2015
TL;DR: An efficient method for collecting magnetic data using a mobile robot and a method for building a magnetic map using Gaussian processes are proposed to make it possible to build a large-scale magnetic map efficiently.
Abstract: The magnetic field that exists in an indoor environment includes rich magnetic fluctuations because buildings contain many magnetized materials (e.g., steel frames). These fluctuations can be used as landmarks, the use of which requires the creation of a magnetic map representing the distribution of the magnetic field. It is, however, difficult to build a large-scale magnetic map because of the narrow measurement range of a magnetic sensor. This paper proposes an efficient method for collecting magnetic data using a mobile robot and a method for building a magnetic map using Gaussian processes. The use of these methods make it possible to build a large-scale magnetic map efficiently. Moreover, this paper presents a particle filter-based localization method based on the magnetic map. The presented system enables a robot to identify its own position in large-scale buildings. Experiments are used to demonstrate the performance and usefulness of the presented system.

Journal ArticleDOI
TL;DR: A volumetric display based on holographic parallel optical access and two-photon excitation using a computer-generated hologram displayed on a liquid crystal spatial light modulator and a multilayer fluorescent screen was proposed and demonstrated.
Abstract: We propose a volumetric display based on holographic parallel optical access and two-photon excitation using a computer-generated hologram displayed on a liquid crystal spatial light modulator and a multilayer fluorescent screen. The holographic parallel optical access increased the number of voxels of the volumetric image per unit time. This approach increased the total input energy to the volumetric display, that is, the total fluorescence power, because the maximum energy incident at a point in the multilayer fluorescent screen is limited by the damage threshold. The multilayer fluorescent screen was newly developed to display colored voxels. The thin layer construction of the multilayer fluorescent screen minimized the axial length of the voxels. A volumetric display with only blue-green voxels and a volumetric display with both blue-green and red voxels were demonstrated.

Journal ArticleDOI
TL;DR: It is concluded that birds use low temperature-induced circulating T3 not only for adaptive thermoregulation but also to trigger apoptosis to accelerate seasonal testicular regression.
Abstract: In temperate zones, animals restrict breeding to specific seasons to maximize the survival of their offspring. Birds have evolved highly sophisticated mechanisms of seasonal regulation, and their testicular mass can change 100-fold within a few weeks. Recent studies on Japanese quail revealed that seasonal gonadal development is regulated by central thyroid hormone activation within the hypothalamus, depending on the photoperiodic changes. By contrast, the mechanisms underlying seasonal testicular regression remain unclear. Here we show the effects of short day and low temperature on testicular regression in quail. Low temperature stimulus accelerated short day-induced testicular regression by shutting down the hypothalamus-pituitary-gonadal axis and inducing meiotic arrest and germ cell apoptosis. Induction of T3 coincided with the climax of testicular regression. Temporal gene expression analysis over the course of apoptosis revealed the suppression of LH response genes and activation of T3 response genes involved in amphibian metamorphosis within the testis. Daily ip administration of T3 mimicked the effects of low temperature stimulus on germ cell apoptosis and testicular mass. Although type 2 deiodinase, a thyroid hormone-activating enzyme, in the brown adipose tissue generates circulating T3 under low-temperature conditions in mammals, there is no distinct brown adipose tissue in birds. In birds, type 2 deiodinase is induced by low temperature exclusively in the liver, which appears to be caused by increased food consumption. We conclude that birds use low temperature-induced circulating T3 not only for adaptive thermoregulation but also to trigger apoptosis to accelerate seasonal testicular regression.

Journal ArticleDOI
02 Nov 2015-eLife
TL;DR: The analysis indicates that repeatedly regenerated lenses showed a robust transcriptional program comparable to young never-regenerated lenses, and establishes the newt as a key model for the study of regeneration in relation to ageing.
Abstract: Newts have the ability to repeatedly regenerate their lens even during ageing. However, it is unclear whether this regeneration reflects an undisturbed genetic activity. To answer this question, we compared the transcriptomes of lenses, irises and tails from aged newts that had undergone lens regeneration 19 times with the equivalent tissues from young newts that had never experienced lens regeneration. Our analysis indicates that repeatedly regenerated lenses showed a robust transcriptional program comparable to young never-regenerated lenses. In contrast, the tail, which was never regenerated, showed gene expression signatures of ageing. Our analysis strongly suggests that, with respect to gene expression, the regenerated lenses have not deviated from a robust transcriptional program even after multiple events of regeneration throughout the life of the newt. In addition, our study provides a new paradigm in biology, and establishes the newt as a key model for the study of regeneration in relation to ageing.

Journal ArticleDOI
TL;DR: Investigation of the effectiveness of the plant growth-promoting rhizobacterium Bacillus pumilus regarding growth promotion and radiocesium ((137)Cs) uptake was evaluated in four Brassica species grown on different contaminated farmlands at Fukushima prefecture in Japan from June to August 2012 found no enhancement in growth in any of the plants.

Journal ArticleDOI
TL;DR: In this article, a self-designed experiment device was used to improve the surface integrity and surface homogeneity with various trajectories by a newly self-design experiment device, and the results showed that the plane homogeneity and surface quality improved in varying degrees after improving the polishing trajectory.
Abstract: This paper aims to improve the surface integrity and surface homogeneity with various trajectories by a newly self-designed experiment device. In the experiments, three kinds of polishing trajectories were studied with attached revolution motion to magnetic abrasive brush (MAB) based on conventional magnetic abrasive finishing (MAF) process. The surface roughness, the cross-sectional shape, and the 3D micro-morphology were chosen as the response variables to explore the feasibility and benefits of the proposed improving polishing method. The results show that the plane homogeneity and surface quality improved in varying degrees after improving the polishing trajectory. In addition, combining MAF theory to analyze related reasons, the trajectory expression of the magnetic abrasive particles (MAPs) was established and was simulated by Graph software. The theoretical analysis is consistent with the experimental results which indicated that analysis of polishing trajectory can be used to predict polishing results. Thus, it is feasible to plan polishing trajectory reasonable according to workpiece profile and surface quality requirements.

Journal ArticleDOI
TL;DR: Planteose metabolism was uncovered as a key metabolic pathway for germination of Orobanche minor and inhibition of planteose metabolism by nojirimycin resulted in selective inhibition of O. minor germination.
Abstract: Root parasitic weeds in Orobanchaceae cause serious damage to worldwide agriculture. Germination of the parasites requires host-derived germination stimulants, such as strigolactones, as indicators of host roots within reach of the parasite's radicles. This unique germination process was focused on to identify metabolic pathways required for germination, and to design a selective control strategy. A metabolomic analysis of germinating seeds of clover broomrape, Orobanche minor, was conducted to identify its distinctive metabolites. Consequently, a galactosyl-sucrose trisaccharide, planteose (α-d-galactopyranosyl-(1→6)-β-d-fructofuranosyl-(2→1)-α-d-glucopyranoside), was identified as a metabolite that decreased promptly after reception of the germination stimulant. To investigate the importance of planteose metabolism, the effects of several glycosidase inhibitors were examined, and nojirimycin bisulfite (NJ) was found to alter the sugar metabolism and to selectively inhibit the germination of O. minor. Planteose consumption was similar in NJ-treated seeds and non-treated germinating seeds; however, NJ-treated seeds showed lower consumption of sucrose, a possible intermediate of planteose metabolism, resulting in significantly less glucose and fructose. This inhibitory effect was recovered by adding glucose. These results suggest that planteose is a storage carbohydrate required for early stage of germination of O. minor, and NJ inhibits germination by blocking the supply of essential glucose from planteose and sucrose. Additionally, NJ selectively inhibited radicle elongation of germinated seeds of Orobanchaceae plants (Striga hermonthica and Phtheirospermum japonicum). Thus, NJ will be a promising tool to develop specific herbicides to the parasites, especially broomrapes, and to improve our understanding of the molecular mechanisms of this unique germination.

Journal ArticleDOI
TL;DR: The single-shot fabrication of a line structure in a glass surface is demonstrated using a line-shaped pulse generated by a holographic cylindrical lens displayed on a liquid-crystal spatial light modulator for showing the potential of holographic line- shaped beam processing.
Abstract: Line-shaped femtosecond pulses are well-suited to large-area machining with high throughput in laser cutting, peeling, and grooving of materials. First, we demonstrated the single-shot fabrication of a line structure in a glass surface using a line-shaped pulse generated by a holographic cylindrical lens displayed on a liquid-crystal spatial light modulator. We found the line structure was uniform and smooth near the ends because of the ability to precisely control the intensity distribution and to achieve single-shot fabrication. Second, we demonstrated a line-shaped beam deformed three-dimensionally for showing the potential of holographic line-shaped beam processing. Third, we demonstrated laser peeling of an indium tin oxide film. We found that little debris around the fabricated area was observed, because the debris was removed by the beam itself. Last, we demonstrated laser grooving of stainless steel. We found the swelling of the surface included upwardly growing nanogratings, although many line-shaped pulse irradiations were given. The swelling was caused by the depositions of the debris on the top of the nanogratings.

Journal ArticleDOI
TL;DR: Higher sterol content regulated by CYP51 with concomitant lower phospholipid contents in root tips results in higher aluminium tolerance, which is common to different varieties of plant species.
Abstract: Several studies have shown that differences in lipid composition and in the lipid biosynthetic pathway affect the aluminium (Al) tolerance of plants, but little is known about the molecular mechanisms underlying these differences. Phospholipids create a negative charge at the surface of the plasma membrane and enhance Al sensitivity as a result of the accumulation of positively charged Al(3+) ions. The phospholipids will be balanced by other electrically neutral lipids, such as sterols. In the present research, Al tolerance was compared among pea (Pisum sativum) genotypes. Compared with Al-tolerant genotypes, the Al-sensitive genotype accumulated more Al in the root tip, had a less intact plasma membrane, and showed a lower expression level of PsCYP51, which encodes obtusifoliol-14α-demethylase (OBT 14DM), a key sterol biosynthetic enzyme. The ratio of phospholipids to sterols was higher in the sensitive genotype than in the tolerant genotypes, suggesting that the sterol biosynthetic pathway plays an important role in Al tolerance. Consistent with this idea, a transgenic Arabidopsis thaliana line with knocked-down AtCYP51 expression showed an Al-sensitive phenotype. Uniconazole-P, an inhibitor of OBT 14DM, suppressed the Al tolerance of Al-tolerant genotypes of maize (Zea mays), sorghum (Sorghum bicolor), rice (Oryza sativa), wheat (Triticum aestivum), and triticale (×Triticosecale Wittmark cv. Currency). These results suggest that increased sterol content, regulated by CYP51, with concomitant lower phospholipid content in the root tip, results in lower negativity of the plasma membrane. This appears to be a common strategy for Al tolerance among several plant species.


Journal ArticleDOI
TL;DR: A novel motion planning technique of multiple mobile robots for human safety and robot efficiency in a field of human–robot interaction is proposed and the significance of the behavior potential based on the actual humans is discussed.
Abstract: In order for robots to exist together with humans, safety for the humans has to be strictly ensured. On the other hand, safety might decrease working efficiency of robots. Namely, this is a trade-off problem between human safety and robot efficiency in a field of human–robot interaction. For this problem, we propose a novel motion planning technique of multiple mobile robots. Two artificial potentials are presented for generating repulsive force. The first potential is provided for humans. The von Mises distribution is used to consider the behavioral property of humans. The second potential is provided for the robots. The Kernel density estimation is used to consider the global robot congestion. Through simulation experiments, the effectiveness of the behavior and congestion potentials of the motion planning technique for human safety and robot efficiency is discussed. Moreover, a sensing system for humans in a real environment is developed. From experimental results, the significance of the behavior pote...

Journal ArticleDOI
01 Mar 2015-Planta
TL;DR: Nitrogen and phosphorus fertilization in one side of split-root sorghum plants systemically reduced root contents of strigolactones in both sides of the split roots, suggesting shoot-derived signals other than auxin appeared to be involved in the regulation of SL production in roots.
Abstract: Nitrogen and phosphorus fertilization in one side of split-root sorghum plants systemically reduced root contents of strigolactones in both sides of the split roots. Shoot-derived signals other than auxin appeared to be involved in this process. Strigolactones (SLs) are a novel class of plant hormones regulating both shoot and root architectures and suggested to be functioning downstream of auxin. The levels of SLs in plant tissues and root exudates are regulated by nutrients, especially phosphorus (P) and nitrogen (N); however, the underlying mechanism remains elusive. We examined the effects of N and P fertilization on root contents of two SLs, sorgomol and 5-deoxystrigol, in sorghum plants pre-incubated under N and P free conditions using a split-root system. N and P fertilization to one side of the split-root plants systemically reduced root contents of SLs in both sides of the split roots. The shoot N and P levels increased when one side of the split-root plants was fertilized, while N and P levels in the non-fertilized split roots were unaffected. N fertilization decreased shoot and root IAA (indole-3-acetic acid) levels, while P fertilization did not affect them. IAA applied to the shoot apices increased root contents of 5-deoxystrigol but not that of sorgomol only when the plants were grown under P free conditions. Shoot (leaf) removal dramatically decreased the root contents of SLs but did not affect root IAA levels, and IAA applied to the stumps of leaves could not restore root contents of SLs. Consequently, shoot-derived signals other than auxin are suggested to be involved in the regulation of SL production in roots.

Journal ArticleDOI
TL;DR: The results show that the optimum capacitance using a buck converter differs from that using a boost converter and the capacitance of the primary-side compensation capacitor also affects the inverter efficiency and resonant-circuit efficiency.
Abstract: When an inductive power transfer system is applied to a battery charger for electric vehicles, a diode bridge rectifier with a dc–dc converter, called a secondary-side converter in this paper, is connected to the secondary side of the resonant circuit in order to regulate the current and voltage of the battery. A compensation capacitor is typically used to improve the input power factor in an inductive power transfer system, and a resonant circuit is configured. This paper presents a design method for the primary compensation capacitor in an inductive power transfer system with series compensation on the primary side and parallel compensation on the secondary side (S/P topology) to connect a boost or buck converter via a rectifier circuit on the receiving side. For the S/P topology, the capacitance of the primary-side compensation capacitor influences the duty ratio of the switch used in the secondary-side converter because it affects the input-to-output voltage ratio of the resonant circuit. Further, the duty ratio of the secondary-side converter affects the resonant-circuit efficiency. In addition, the primary compensation capacitance affects the output power factor of the inverter, which is connected to the primary side of the resonant circuit. Therefore, the capacitance of the primary-side compensation capacitor also affects the inverter efficiency and resonant-circuit efficiency. In this paper, a primary-side capacitor design method is examined. The results show that the optimum capacitance using a buck converter differs from that using a boost converter.

Journal ArticleDOI
TL;DR: Vectorial vortex analysis is used to determine the polarization states of an arbitrarily polarized terahertz beam using THz achromatic axially symmetric wave (TAS) plates, which have a phase retardance of Δ = 163° and are made of polytetrafluorethylene.
Abstract: Vectorial vortex analysis is used to determine the polarization states of an arbitrarily polarized terahertz (0.1–1.6 THz) beam using THz achromatic axially symmetric wave (TAS) plates, which have a phase retardance of Δ = 163° and are made of polytetrafluorethylene. Polarized THz beams are converted into THz vectorial vortex beams with no spatial or wavelength dispersion, and the unknown polarization states of the incident THz beams are reconstructed. The polarization determination is also demonstrated at frequencies of 0.16 and 0.36 THz. The results obtained by solving the inverse source problem agree with the values used in the experiments. This vectorial vortex analysis enables a determination of the polarization states of the incident THz beam from the THz image. The polarization states of the beams are estimated after they pass through the TAS plates. The results validate this new approach to polarization detection for intense THz sources. It could find application in such cutting edge areas of physics as nonlinear THz photonics and plasmon excitation, because TAS plates not only instantaneously elucidate the polarization of an enclosed THz beam but can also passively control THz vectorial vortex beams.

Journal ArticleDOI
TL;DR: In this paper, the authors identify spectral features that coincide with the reflectance characteristics of available MLMs, determine the conditions under which they are optimized and establish the maximum conversion efficiencies obtainable.
Abstract: Lithography tools are being built and shipped to semiconductor manufacturers for high volume manufacturing using extreme ultraviolet lithography (EUVL) at a wavelength of 13.5 nm. This wavelength is based on the availability of Mo/Si multilayer mirrors (MLMs) with a reflectivity of ~70% at this wavelength. Moreover, the primary lithography tool manufacturer, ASML, has identified 6.x nm, where x~7, as the wavelength of choice for so-called Beyond EUVL, based on the availability of La/B4C MLMs, with theoretical reflectance approaching 80% at this wavelength. The optimum sources have been identified as laser produced plasmas of Gd and Tb, as n = 4–n = 4 transitions in their ions emit strongly near this wavelength. However, to date, the highest conversion efficiency obtained, for laser to EUV energy emitted within the 0.6% wavelength bandwidth of the mirror is only 0.8%, pointing to the need to identify other potential sources or consider the selection of other wavelengths. At the same time, sources for other applications are being developed. Conventional sources for soft x-ray microscopy use H-like line emission from liquid nitrogen or carbon containing liquid jets which can be focused using zone plates. Recently the possibility of using MLMs with n = 4−n = 4 emission from a highly charged Bi plasma was proposed and subsequently the possibility of using Δn = 1 transitions in 3rd row transition elements was identified. All of these studies seek to identify spectral features that coincide with the reflectance characteristics of available MLMs, determine the conditions under which they are optimized and establish the maximum conversion efficiencies obtainable. Thus, there is a need for systematic studies of laser produced plasmas of a wide range of elements as some of the challenges are similar for all of these sources and some recent results will be presented.

Journal ArticleDOI
10 Jun 2015-PLOS ONE
TL;DR: It is suggested that the selection of sperm exhibiting progressive motility may not always be better for early embryo development and fetal growth following human ICSI, and that the use of a bovine model may contribute to a deeper understanding of sperm selection for human I CSI embryo development.
Abstract: Intracytoplasmic sperm injection (ICSI) has become the method of choice to treat human male infertility. One of the outstanding problems associated with this technique is our current lack of knowledge concerning the effect of sperm capacitation and motility upon the subsequent development of oocytes following ICSI. In the present study, we first examined the capacitation state of sperm exhibiting normal motility, along with sperm that had been activated, and examined the effect of reactive oxygen species (ROS) produced by these sperm types upon embryogenesis following bovine in vitro fertilization (IVF) and ICSI. Data showed that activated sperm reduced the chromosomal integrity of IVF/ICSI embryos at the blastocyst stage, while capacitated sperm produced ROS in capacitation media. Secondly, we treated sperm with carbonyl cyanide m-chlorophenyl hydrazine (CCCP), a chemical known to uncouple cell respiration within the mitochondria, and investigated the effect of this treatment upon blastocyst formation and chromosomal integrity at the blastocyst stage. Activated sperm in which the mitochondria had been treated with CCCP reduced levels of chromosomal aberration at the blastocyst stage following ICSI, by reducing mitochondrial activity in activated sperm. In conclusion, these findings suggest that capacitated sperm exhibiting activated motility induced chromosomal aberration during development to the blastocyst stage following ICSI. The injection of sperm exhibiting normal motility, or activated sperm in which mitochondrial activity had been reduced, improved the quality of ICSI-derived embryos. Therefore, the selection of sperm exhibiting progressive motility may not always be better for early embryo development and fetal growth following human ICSI, and that the use of a bovine model may contribute to a deeper understanding of sperm selection for human ICSI embryo development.