Showing papers by "Mitsubishi published in 2009"

Thermally Activated Delayed Fluorescence from Sn4+–Porphyrin Complexes and Their Application to Organic Light Emitting Diodes — A Novel Mechanism for Electroluminescence

Abstract: [*] Prof. C. Adachi, A. Endo, Dr. D. Yokoyama Center for Future Chemistry Kyushu University 744 Motooka Nishi, Fukuoka 819-0395 (Japan) E-mail: adachi@cstf.kyushu-u.ac.jp M. Ogasawara, Prof. Y. Kato Department of Materials Science and Engineering Kyushu University 744 Motooka Nishi, Fukuoka 819-0395 (Japan) Dr. A. Takahashi Sogo Pharmaceutical Co., Ltd. Hebinami 28-3, Johban Shimofunao Iwaki, Fukushima 972-8312 (Japan) [+] Present address: Mitsubishi Chemical Group Science and Technology Research Center, Inc., Display Project, Research and Development Division, 1000 Kamoshida-cho, Aoba-ku, Yokohama 227-8502, Japan.

Multi-class active learning for image classification

Abstract: One of the principal bottlenecks in applying learning techniques to classification problems is the large amount of labeled training data required. Especially for images and video, providing training data is very expensive in terms of human time and effort. In this paper we propose an active learning approach to tackle the problem. Instead of passively accepting random training examples, the active learning algorithm iteratively selects unlabeled examples for the user to label, so that human effort is focused on labeling the most “useful” examples. Our method relies on the idea of uncertainty sampling, in which the algorithm selects unlabeled examples that it finds hardest to classify. Specifically, we propose an uncertainty measure that generalizes margin-based uncertainty to the multi-class case and is easy to compute, so that active learning can handle a large number of classes and large data sizes efficiently. We demonstrate results for letter and digit recognition on datasets from the UCI repository, object recognition results on the Caltech-101 dataset, and scene categorization results on a dataset of 13 natural scene categories. The proposed method gives large reductions in the number of training examples required over random selection to achieve similar classification accuracy, with little computational overhead.

Tubulin tyrosination navigates the kinesin-1 motor domain to axons

Abstract: Neurons form distinctive axonal and dendritic compartments that are important for directional signaling, but the mechanisms that discriminate between axons and dendrites remain elusive. Previous studies have demonstrated that the kinesin-1 motor domain is capable of distinguishing the axon from dendrites. Here we found that the amino acid substitutions in the beta5-loop8 region transformed truncated kinesin-1 from a uni-destination (that is, the axon-specific destination) to a bi-destination (that is, axons and dendrites) state. Furthermore, tyrosinated tubulins that are abundant in somatodendrites prevent the wild-type kinesin-1 from binding to microtubules, whereas the bi-destination-type kinesin-1 does not have this inhibition. Consistently, inhibition of tubulin tyrosination in rat hippocampal neurons resulted in the distribution of truncated kinesin-1 in both axons and dendrites. Our study identifies a molecular mechanism that discriminates the axonal microtubules from somatodendritic microtubules, as well as a previously unknown linkage between tubulin modification and polarized trafficking in neurons.

UWB Systems for Wireless Sensor Networks

Abstract: Wireless sensor networks are emerging as an important area for communications. They enable a wealth of new applications including surveillance, building control, factory automation, and in-vehicle sensing. The sensor nodes have to operate under severe constraints on energy consumption and form factor, and provide the ability for precise self-location of the nodes. These requirements can be fulfilled very well by various forms of ultra-wide-band (UWB) transmission technology. We discuss various techniques and tradeoffs in UWB systems and indicate that time-hopping and frequency-hopping impulse radio physical layers combined with simple multiple-access techniques like ALOHA are suitable designs. We also describe the IEEE 802.15.4a standard, an important system that adopts UWB impulse radio to ensure robust data communications and precision ranging. In order to accommodate heterogeneous networks, it uses specific modulation, coding, and ranging waveforms that can be detected well by both coherent and noncoherent receivers.

Solubility of Lithium Salts Formed on the Lithium-Ion Battery Negative Electrode Surface in Organic Solvents

Abstract: The solubility of lithium salts in dimethyl carbonate (DMC) found in solid electrolyte interface (SEI) films was determined. The salt-DMC solutions evaporated, and the salts were transferred into water for ion conductivity measurements. The salts examined included lithium carbonate (Li 2 CO 3 ), lithium oxalate [(LiCO 2 ) 2 ], lithium fluoride (LiF), lithium hydroxide (LiOH), lithium methyl carbonate (LiOCO 2 ,CH 3 ), and lithium ethyl carbonate (LiOCO 2 C 2 H 5 ). The salt molarity in DMC ranged from 9.6 X 10- 4 mol L -1 (LiOCO 2 CH 3 ) to 9 X 10 -5 mol L -1 (Li 2 CO 3 ) in the order of LiOCO 2 CH 3 > LiOCO 2 C 2 H 5 > LiOH > LiF > (LiCO 2 ) 2 > Li 2 CO 3 - X-ray photoelectron spectroscopy measurements on SEI films on the surface of the negative electrode taken from a commercial battery after soaking in DMC for 1 h suggested that the films can dissolve. Separately, the heat of dissolution of the salts was calculated from computer simulations for the same salts, including lithium oxide (Li 2 O), lithium methoxide (LiOCH 3 ), and dilithium ethylene glycol dicarbonate [(CH 2 OCO 2 Li) 2 :LiEDC] in both DMC and ethylene carbonate (EC). The results from the computer simulations suggested that the order in which the salt was likely to dissolve in both DMC and EC was LiEDC > LiOCO 2 CH 3 > LiOH > LiOCO 2 C 2 H 5 > LiOCH 3 > LiF > (LiCO 2 ) 2 > Li 2 CO 3 > Li 2 O. This order agreed with the experiment in DMC within the experimental error. Both experiment and computer simulations showed that the organic salts are more likely to dissolve in DMC than the inorganic salts. The calculations also predicted that the salts dissolve more likely in EC than in DMC in general. Moreover, the results from the study were used to discuss the capacity fading mechanism during the storage of lithium-ion batteries.

Measurement of internal body time by blood metabolomics

Abstract: Detection of internal body time (BT) via a few-time-point assay has been a longstanding challenge in medicine, because BT information can be exploited to maximize potency and minimize toxicity during drug administration and thus will enable highly optimized medication. To address this challenge, we previously developed the concept, “molecular-timetable method,” which was originally inspired by Linne's flower clock. In Linne's flower clock, one can estimate the time of the day by watching the opening and closing pattern of various flowers. Similarly, in the molecular-timetable method, one can measure the BT of the day by profiling the up and down patterns of substances in the molecular timetable. To make this method clinically feasible, we now performed blood metabolome analysis and here report the successful quantification of hundreds of clock-controlled metabolites in mouse plasma. Based on circadian blood metabolomics, we can detect individual BT under various conditions, demonstrating its robustness against genetic background, sex, age, and feeding differences. The power of this method is also demonstrated by the sensitive and accurate detection of circadian rhythm disorder in jet-lagged mice. These results suggest the potential for metabolomics-based detection of BT (“metabolite-timetable method”), which will lead to the realization of chronotherapy and personalized medicine.

Vitamin D receptor alleles, bone mineral density and turnover in premenopausal Japanese women

Abstract: Recent studies have shown that genetic effects on bone mineral density (BMD) and bone turnover are related to allelic variation in the vitamin D receptor (VDR) gene. We examined allelic influences of the VDR gene on bone turnover and density in 202 normal healthy premenopausal Japanese women (age 30.1 +/- 1.2, mean +/- SEM). The VDR effect on BMD and turnover is similar to that observed in Caucasian women; however, there are major differences in allele frequency. The B allele by BsmI restriction fragment length polymorphisms (RFLPs), associated with low BMD and high bone turnover, is found in only 12% of Japanese women (1.4% homozygote BB), compared with 41% of Caucasians (16.7% homozygote BB). In comparing the two most frequent genotypes, Bb heterozygotes (21.5%) and bb homozygotes (77.1%), BMD is 5.3% lower in Bb heterozygotes, and levels of bone formation markers including osteocalcin and bone-specific alkaline phosphatase are 20-32% higher with lower serum calcium (2.30 +/- 0.02 vs 2.35 +/- 0.01 mmol/l) and higher 1,25-dihydroxyvitamin D (95 +/- 4.8 vs. 76 +/- 3.8 pmol/l). Further discrimination of the genotype was achieved using two additional RFLPs (ApaI, A and TaqI, T); the lumbar spine BMD of the common genotype BbAATt was 9.3% (0.94 SD) lower than in the bbaaTT genotype in premenopausal Japanese women. These data confirm that VDR RFLPs affect bone mineral metabolism regardless of racial differences. Moreover, the VDR genotypes based on haplotype analysis should yield useful insights into the potential prevention of osteoporosis.

GPS Multipath Mitigation for Urban Area Using Omnidirectional Infrared Camera

Abstract: This paper describes a precision positioning technique that can be applied to vehicles in urban areas. The proposed technique mitigates Global Positioning System (GPS) multipath by means of an omnidirectional infrared (IR) camera that can eliminate the need for invisible satellites [a satellite detected by the receiver but without line of sight (LOS)] by using IR images. Some simple GPS multipath mitigation techniques, such as the installation of antennas away from buildings and using choke ring antennas, are well known. Further, various correlator techniques can also be employed. However, when a direct signal cannot be received by the antenna, these techniques do not provide satisfactory results because they presume that the antenna chiefly receives direct signals. On the other hand, the proposed technique can mitigate GPS multipath, even if a direct signal cannot be received because it can recognize the surrounding environment by means of an omnidirectional IR camera. With the IR camera, the sky appears distinctively dark; this facilitates the detection of the borderline between the sky and the surrounding buildings, which are captured in white, due to the difference in the atmospheric transmittance rate between visible light and IR rays. Positioning is performed only with visible satellites having fewer multipath errors and without using invisible satellites. With the proposed system, static and kinematic evaluations in which invisible satellites are discriminated through observation using an omnidirectional IR camera are conducted. Hence, signals are received even if satellites are hidden behind buildings; furthermore, the exclusion of satellites having large errors from the positioning computation becomes possible. The evaluation results confirm the effectiveness of the proposed technique and the feasibility of highly accurate positioning.

Activin signaling as an emerging target for therapeutic interventions

Abstract: After the initial discovery of activins as important regulators of reproduction, novel and diverse roles have been unraveled for them. Activins are expressed in various tissues and have a broad range of activities including the regulation of gonadal function, hormonal homeostasis, growth and differentiation of musculoskeletal tissues, regulation of growth and metastasis of cancer cells, proliferation and differentiation of embryonic stem cells, and even higher brain functions. Activins signal through a combination of type I and II transmembrane serine/threonine kinase receptors. Activin receptors are shared by multiple transforming growth factor-β (TGF-β) ligands such as myostatin, growth and differentiation factor-11 and nodal. Thus, although the activity of each ligand is distinct, they are also redundant, both physiologically and pathologically in vivo. Activin receptors activated by ligands phosphorylate the receptor-regulated Smads for TGF-β, Smad2 and 3. The Smad proteins then undergo multimerization with the co-mediator Smad4, and translocate into the nucleus to regulate the transcription of target genes in cooperation with nuclear cofactors. Signaling through receptors and Smads is controlled by multiple mechanisms including phosphorylation and other posttranslational modifications such as sumoylation, which affect potein localization, stability and transcriptional activity. Non-Smad signaling also plays an important role in activin signaling. Extracellularly, follistatin and related proteins bind to activins and related TGF-β ligands, and control the signaling and availability of ligands. The functions of activins through activin receptors are pleiotrophic, cell type-specific and contextual, and they are involved in the etiology and pathogenesis of a variety of diseases. Accordingly, activin signaling may be a target for therapeutic interventions. In this review, we summarize the current knowledge on activin signaling and discuss the potential roles of this pathway as a molecular target of therapy for metabolic diseases, musculoskeletal disorders, cancers and neural damages.

Association of leukocyte and neutrophil counts with infarct size, left ventricular function and outcomes after percutaneous coronary intervention for ST-elevation myocardial infarction.

Abstract: Elevated leukocyte count during ST-segment elevation myocardial infarction is associated with adverse clinical outcomes. Whether increased leukocyte count after primary percutaneous coronary intervention (PCI) directly reflects larger infarct size and left ventricular impairment is not known. The aim of this study was to assess the relation between leukocyte and neutrophil counts with infarct size and the left ventricular ejection fraction (LVEF) after primary PCI. Three hundred sixty-three patients from the Evaluation of MCC-135 for Left Ventricular Salvage in Acute Myocardial Infarction (EVOLVE) study, a randomized, double-blind, placebo-controlled trial assessing the efficacy of intracellular calcium modulator as an adjunct to primary PCI in patients with first ST-segment elevation myocardial infarctions, were evaluated. Total and differential leukocyte counts were measured before and serially after PCI. Infarct size and the LVEF were assessed using single-photon emission computed tomography after 5 and 30 days, and patients were followed up to 180 days. Total leukocyte and neutrophil counts obtained 24 hours after PCI were significantly correlated with infarct size (r = 0.34 and 0.37, respectively, p <0.001) and inversely correlated with the LVEF (r = -0.20 and -0.22, respectively, p <0.001). Patients with elevated leukocyte and neutrophil counts had larger infarct sizes (12.5% vs 5% and 13.5% vs 5%, respectively, p <0.001). The highest neutrophil quartile was associated with increased 180-day composite cardiac events (19% vs 20% vs 23% vs 45%, log-rank p <0.001). Elevated leukocyte and neutrophil counts independently predicted adverse cardiac events (hazard ratios 2.5 and 2.2, respectively, p = 0.001). In conclusion, elevated leukocyte and neutrophil counts after primary PCI in patients with ST-segment elevation myocardial infarctions are directly related to myocardial infarct size and the LVEF and are independent predictors of cardiovascular outcomes.

Design of a Data-Driven PID Controller

Abstract: Since most processes have nonlinearities, controller design schemes to deal with such systems are required. On the other hand, proportional-integral-derivative (PID) controllers have been widely used for process systems. Therefore, in this paper, a new design scheme of PID controllers based on a data-driven (DD) technique is proposed for nonlinear systems. According to the DD technique, a suitable set of PID parameters is automatically generated based on input/output data pairs of the controlled object stored in the database. This scheme can adjust the PID parameters in an online manner even if the system has nonlinear properties and/or time-variant system parameters. Finally, the effectiveness of the newly proposed control scheme is evaluated on some simulation examples, and a pilot-scale temperature control system.

Passivity-Based Attitude Synchronization in $SE(3)$

Abstract: This paper addresses passivity-based motion coordination of rigid bodies in the special Euclidean group SE(3) under the assumption that the agents exchange information over strongly connected graphs. In this paper, we especially focus on one of the motion coordination problems on SE(3) called attitude synchronization. We first develop a passivity-based distributed velocity input law to achieve attitude synchronization. Using the notion of algebraic connectivity, we then establish a connection between the speed of convergence and the structure of the interconnection graph. We also prove attitude synchronization in the leader-follower case and in the cases of communication delay and temporary communication failures. Finally, the performance of our developed control laws is demonstrated through both numerical simulation and experiments on a planar (2D) test bed.

Possible lunar lava tube skylight observed by SELENE cameras

Abstract: [1] We discovered a vertical hole on the Moon, which is a possible lava tube skylight, using data from SELENE's two high-resolution cameras: the Terrain Camera and the Multi-band Imager. The hole is nearly circular, 65 m in diameter, and located in a sinuous rille at the Marius Hills region, a volcanic province on the lunar nearside. We observed the hole at various solar illumination conditions and estimated its depth to be 80 to 88 m. The depth/diameter ratio is much larger than for typical impact craters. There are neither conspicuous deposits indicating volcanic eruptions from the hole, nor are there pit craters adjacent to the hole that could be related to an underlying fault or dike. The area around the hole is covered by a thin (20 to 25 m) lava sheet, which may help protect the lava tube from collapse due to meteorite bombardment.

A Comprehensive Analysis of the Soybean Genes and Proteins Expressed under Flooding Stress using Transcriptome and Proteome Techniques

Abstract: The inducible genes and proteins were analyzed using transcriptome and proteome techniques to explore the mechanisms underlying soybean response to flooding stress. Soybean seedlings were germinated for 2 days and subjected to flooding for 12 h, and the total RNAs and proteins were extracted from the root and hypocotyl. High-coverage gene expression profiling analysis as transcriptome technique was performed. Ninety-seven out of the 29 388 peaks observed demonstrated a greater than 25-fold change following 12 h of flood-induced stress. Furthermore, 34 proteins out of 799 proteins were changed by 12 h stress. Genes associated with alcohol fermentation, ethylene biosynthesis, pathogen defense, and cell wall loosening were significantly up-regulated. Hemoglobin, acid phosphatase, and Kunitz trypsin protease inhibitor were altered at both transcriptional and translational levels. Reactive oxygen species scavengers and chaperons were changed only at the translational level. It is suggested that the early respo...

Increase of vascular endothelial growth factor mRNA expression by 1,25‐dihydroxyvitamin D3 in human osteoblast‐like cells

Abstract: Vascular endothelial growth factor (VEGF), a secreted endothelial cell-specific mitogen, is produced in endocrine organs and regulated by trophic hormones. Because angiogenesis and osteogenesis are closely regulated, we studied whether human osteoblast-like cells produce VEGF, and if so, what factors regulate VEGF mRNA expression. Human osteoblast-like cells (HObLC) derived from trabecular bone explants were cultured in α-MEM supplemented with 10% fetal calf serum. Northern blot analysis revealed that HObLC expressed VEGF mRNA, as did several human osteosarcoma cells. 1,25-(OH)2D3 increased the steady-state levels of VEGF mRNA in a time- and concentration-dependent manner in HObLC and one of the osteosarcoma cell lines, SaOS-2, accompanied by an increase in the concentration of immunoreactive VEGF in the conditioned medium. PTH and IGF-I also increased the level of VEGF mRNA in HObLC and SaOS-2 cells. Furthermore, 12-O-tetradecanoylphorbol ester stimulated VEGF mRNA in a time-and concentration-dependent manner. The VEGF mRNA expression induced by 1,25-(OH)2D3 was completely inhibited by H-7, but only partially by staurosporine. We have demonstrated that PTH, IGF-I, and most potently 1,25-(OH)2D3 stimulate the mRNA expression and secretion of VEGF in human osteoblast-like cells, suggesting that one of the anabolic effects of 1,25-(OH)2D3 on skeletal tissue may be mediated by VEGF produced by osteoblasts.

Levels of complexity in scale-invariant neural signals.

Abstract: Many physical and physiological signals exhibit complex scale-invariant features characterized by 1/f scaling and long-range power-law correlations, indicating a possibly common control mechanism. Specifically, it has been suggested that dynamical processes, influenced by inputs and feedback on multiple time scales, may be sufficient to give rise to 1/f scaling and scale invariance. Two examples of physiologic signals that are the output of hierarchical multiscale physiologic systems under neural control are the human heartbeat and human gait. Here we show that while both cardiac interbeat interval and gait interstride interval time series under healthy conditions have comparable 1/f scaling, they still may belong to different complexity classes. Our analysis of the multifractal scaling exponents of the fluctuations in these two signals demonstrates that in contrast to the multifractal behavior found in healthy heartbeat dynamics, gait time series exhibit less complex, close to monofractal behavior. Further, we find strong anticorrelations in the sign and close to random behavior for the magnitude of gait fluctuations at short and intermediate time scales, in contrast to weak anticorrelations in the sign and strong positive correlation for the magnitude of heartbeat interval fluctuations-suggesting that the neural mechanisms of cardiac and gait control exhibit different linear and nonlinear features. These findings are of interest because they underscore the limitations of traditional two-point correlation methods in fully characterizing physiological and physical dynamics. In addition, these results suggest that different mechanisms of control may be responsible for varying levels of complexity observed in physiological systems under neural regulation and in physical systems that possess similar 1/f scaling.

History and Applications of UWB [Scanning the Issue]

Abstract: This mathematical modeling method for wireless networks is designed to take into account propagation effects and interference from unwanted transmissions.

KAIKObase: an integrated silkworm genome database and data mining tool.

Abstract: The silkworm, Bombyx mori, is one of the most economically important insects in many developing countries owing to its large-scale cultivation for silk production. With the development of genomic and biotechnological tools, B. mori has also become an important bioreactor for production of various recombinant proteins of biomedical interest. In 2004, two genome sequencing projects for B. mori were reported independently by Chinese and Japanese teams; however, the datasets were insufficient for building long genomic scaffolds which are essential for unambiguous annotation of the genome. Now, both the datasets have been merged and assembled through a joint collaboration between the two groups.

Next-generation PON-part II: Candidate systems for next-generation PON

Abstract: Given the requirements for a next-generation PON, the architecture of the system solution must be considered. There are many different systems that can provide the services and system-level features desired for a next generation PON; however, each has its own challenges and advantages. This article presents the set of possible solutions, and puts them into perspective of likely standardization. It also considers how the key requirement of coexistence could be accommodated.

Difficulties in applying extended producer responsibility policies in developing countries: case studies in e-waste recycling in China and Thailand

Abstract: Developing Asian countries have started to apply the principle of extended producer responsibility (EPR) to electronics and electrical equipment waste (e-waste). This policy approach aims to give electronic appliance manufacturers and importers responsibility for the collection and recycling of discarded electronic equipment. China and Thailand have drafted regulations on the recycling of e-waste with common characteristics such as the financial responsibility of producers and subsidies for collection. Although the proposed system is sensible, taking into account the fact that e-waste is a market-traded commodity, there are two major difficulties in implementing EPR in developing countries. First, it may be difficult for governments to collect funds from producers or importers if smuggled, imitation, or small shop-assembled products have a large share in the market. Second, the system creates incentives for collectors and recyclers to over-report the amount of collected e-waste in order to gain extra subsidies from the fund. Other policy measures such as the enforcement of pollution control regulations on informal recyclers, the prevention of smuggling, and the protection of intellectual property rights should accompany EPR policies.

Arachidonic acid drives postnatal neurogenesis and elicits a beneficial effect on prepulse inhibition, a biological trait of psychiatric illnesses.

Abstract: Prepulse inhibition (PPI) is a compelling endophenotype (biological markers) for mental disorders including schizophrenia. In a previous study, we identified Fabp7, a fatty acid binding protein 7 as one of the genes controlling PPI in mice and showed that this gene was associated with schizophrenia. We also demonstrated that disrupting Fabp7 dampened hippocampal neurogenesis. In this study, we examined a link between neurogenesis and PPI using different animal models and exploring the possibility of postnatal manipulation of neurogenesis affecting PPI, since gene-deficient mice show biological disturbances from prenatal stages. In parallel, we tested the potential for dietary polyunsaturated fatty acids (PUFAs), arachidonic acid (ARA) and/or docosahexaenoic acid (DHA), to promote neurogenesis and improve PPI. PUFAs are ligands for Fabp members and are abundantly expressed in neural stem/progenitor cells in the hippocampus. Our results are: (1) an independent model animal, Pax6 (+/−) rats, exhibited PPI deficits along with impaired postnatal neurogenesis; (2) methylazoxymethanol acetate (an anti-proliferative drug) elicited decreased neurogenesis even in postnatal period, and PPI defects in young adult rats (10 weeks) when the drug was given at the juvenile stage (4–5 weeks); (3) administering ARA for 4 weeks after birth promoted neurogenesis in wild type rats; (4) raising Pax6 (+/−) pups on an ARA-containing diet enhanced neurogenesis and partially improved PPI in adult animals. These results suggest the potential benefit of ARA in ameliorating PPI deficits relevant to psychiatric disorders and suggest that the effect may be correlated with augmented postnatal neurogenesis.

Efficient On-Chip Crosstalk Avoidance CODEC Design

Abstract: Interconnect delay has become a limiting factor for circuit performance in deep sub-micrometer designs. As the crosstalk in an on-chip bus is highly dependent on the data patterns transmitted on the bus, different crosstalk avoidance coding schemes have been proposed to boost the bus speed and/or reduce the overall energy consumption. Despite the availability of the codes, no systematic mapping of data words to codewords has been proposed for CODEC design. This is mainly due to the nonlinear nature of the crosstalk avoidance codes (CAC). The lack of practical CODEC construction schemes has hampered the use of such codes in practical designs. This work presents guidelines for the CODEC design of the ldquoforbidden pattern free crosstalk avoidance coderdquo (FPF-CAC). We analyze the properties of the FPF-CAC and show that mathematically, a mapping scheme exists based on the representation of numbers in the Fibonacci numeral system. Our first proposed CODEC design offers a near-optimal area overhead performance. An improved version of the CODEC is then presented, which achieves theoretical optimal performance. We also investigate the implementation details of the CODECs, including design complexity and the speed. Optimization schemes are provided to reduce the size of the CODEC and improve its speed.