64 research outputs found

    High-Speed Tactile Sensing for Array-Type Tactile Sensor and Object Manipulation Based on Tactile Information

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    We have developed a universal robot hand with tactile and other sensors. An array-type tactile sensor is crucial for dexterous manipulation of objects using a robotic hand, since this sensor can measure the pressure distribution on finger pads. The sensor has a very high resolution, and the shape of a grasped object can be classified by using this sensor. The more the number of measurement points provided, the higher the accuracy of the classification, but with a corresponding lengthening of the measurement cycle. In this paper, the problem of slow response time is resolved by using software for an array-type tactile sensor with high resolution that emulates the human sensor system. The validity of the proposed method is demonstrated through experiments

    An interspecific linkage map of SSR and intronic polymorphism markers in tomato

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    Despite the collection and availability of abundant tomato genome sequences, PCR-based markers adapted to large scale analysis have not been developed in tomato species. Therefore, using public genome sequence data in tomato, we developed three types of DNA markers: expressed sequence tag (EST)-derived simple sequence repeat (SSR) markers (TES markers), genome-derived SSR markers (TGS markers) and EST-derived intronic polymorphism markers (TEI markers). A total of 2,047 TES, 3,510 TGS and 674 TEI markers were established and used in the polymorphic analysis of a cultivated tomato (Solanum lycopersicum) ‘LA925’ and its wild relative Solanum pennellii ‘LA716’, parents of the Tomato-EXPEN 2000 mapping population. The polymorphic ratios between parents revealed by the TES, TGS and TEI markers were 37.3, 22.6 and 80.0%, respectively. Those showing polymorphisms were used to genotype the Tomato-EXPEN 2000 mapping population, and a high-density genetic linkage map composed of 1,433 new and 683 existing marker loci was constructed on 12 chromosomes, covering 1,503.1 cM. In the present map, 48% of the mapped TGS loci were located within heterochromatic regions, while 18 and 21% of TES and TEI loci, respectively, were located in heterochromatin. The large number of SSR and SNP markers developed in this study provide easily handling genomic tools for molecular breeding in tomato. Information on the DNA markers developed in this study is available at http://www.kazusa.or.jp/tomato/

    Characterization of active miniature inverted-repeat transposable elements in the peanut genome

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    Miniature inverted-repeat transposable elements (MITEs), some of which are known as active non-autonomous DNA transposons, are found in the genomes of plants and animals. In peanut (Arachis hypogaea), AhMITE1 has been identified in a gene for fatty-acid desaturase, and possessed excision activity. However, the AhMITE1 distribution and frequency of excision have not been determined for the peanut genome. In order to characterize AhMITE1s, their genomic diversity and transposition ability was investigated. Southern blot analysis indicated high AhMITE1 copy number in the genomes of A. hypogaea, A. magna and A. monticola, but not in A. duranensis. A total of 504 AhMITE1s were identified from the MITE-enriched genomic libraries of A. hypogaea. The representative AhMITE1s exhibited a mean length of 205.5 bp and a GC content of 30.1%, with AT-rich, 9 bp target site duplications and 25 bp terminal inverted repeats. PCR analyses were performed using primer pairs designed against both flanking sequences of each AhMITE1. These analyses detected polymorphisms at 169 out of 411 insertional loci in the four peanut lines. In subsequent analyses of 60 gamma-irradiated mutant lines, four AhMITE1 excisions showed footprint mutations at the 109 loci tested. This study characterizes AhMITE1s in peanut and discusses their use as DNA markers and mutagens for the genetics, genomics and breeding of peanut and its relatives

    Cryptotanshinone suppresses tumorigenesis by inhibiting lipogenesis and promoting reactive oxygen species production in KRAS‑activated pancreatic cancer cells

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    Pyruvate dehydrogenase kinase 4 (PDK4) is an important regulator of energy metabolism. Previously, knockdown of PDK4 by specific small interfering RNAs (siRNAs) have been shown to suppress the expression of Κirsten rat sarcoma viral oncogene homolog (KRAS) and the growth of lung and colorectal cancer cells, indicating that PDK4 is an attractive target of cancer therapy by altering energy metabolism. The authors previously reported that a novel small molecule, cryptotanshinone (CPT), which inhibits PDK4 activity, suppresses the in vitro three‑dimensional (3D)‑spheroid formation and in vivo tumorigenesis of KRAS‑activated human pancreatic and colorectal cancer cells. The present study investigated the molecular mechanism of CPT‑induced tumor suppression via alteration of glutamine and lipid metabolism in human pancreatic and colon cancer cell lines with mutant and wild‑type KRAS. The antitumor effect of CPT was more pronounced in the cancer cells containing mutant KRAS compared with those containing wild‑type KRAS. CPT treatment decreased glutamine and lipid metabolism, affected redox regulation and increased reactive oxygen species (ROS) production in the pancreatic cancer cell line MIAPaCa‑2 containing mutant KRAS. Suppression of activated KRAS by specific siRNAs decreased 3D‑spheroid formation, the expression of acetyl‑CoA carboxylase 1 and fatty acid synthase (FASN) and lipid synthesis. The suppression also reduced glutathione‑SH/glutathione disulfide and increased the production of ROS. Knockdown of FASN suppressed lipid synthesis in MIAPaCa‑2 cells, partially promoted ROS production and mildly suppressed 3D‑spheroid formation. These results indicated that CPT reduced tumorigenesis by inhibiting lipid metabolism and promoting ROS production in a mutant KRAS‑dependent manner. This PDK4 inhibitor could serve as a novel therapeutic drug for KRAS‑driven intractable cancers via alteration of cell metabolism

    Electromagnetic-inductive Measurements for the Undeformed and Deformed Sea-ice and Snow in the East Antarctic

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    Indirect ice and snow thickness measurements were carried out for the winter and spring Antarctic sea ice by using the electromagneticinductive (EMI) device on the East Antarctic pack ice area. This study investigated the effect of saline slush snow layer over the sea ice and seawater-filled gap to the snow and sea ice thickness measured by EMI. A result shows underestimations of EMI thickness, which might be caused by high conductive seawater-filled gaps between ice floes, appeared on thicker ice over 3.5 m. This study improved the validity of applying a multi-rafted ice model for these ice conditions.14th (2004) International Offshore and Polar Engineering Conference. 23-28 May 2004. Toulon, France

    <Note>The first case of hunting and consuming an anomalure by chimpanzees (Pan troglodytes schweinfurthii) in Kalinzu forest, Uganda

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    Hunting and meat-eating by chimpanzees have long been attracting researchers’ attention. Although chimpanzees consume various vertebrate species, the frequency of meat-eating and prey species differ among populations and groups. Here, we present the first documented case of chimpanzees consuming Lord Derby's anomalure in the Kalinzu forest, Uganda. Despite anomalure species inhabit some long-term field sites of chimpanzee, reports of chimpanzees consuming anomalures are rare, with only one previous case documented in Outamba–Kilimi National Park, Sierra Leone. In the current case, three males consumed the meat and their meat-eating patterns closely resemble those of chimpanzees at this site when consuming their usual prey. Obtaining further observations of these rare events may contribute to gaining a more comprehensive understanding of chimpanzee hunting and feeding culture
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