1,255 research outputs found
Twistor formulation of a massive particle with rigidity
A massive rigid particle model in dimensions is reformulated in terms
of twistors. Beginning with a first-order Lagrangian, we establish a twistor
representation of the Lagrangian for a massive particle with rigidity. The
twistorial Lagrangian derived in this way remains invariant under a local transformation of the twistor and other relevant variables.
Considering this fact, we carry out a partial gauge-fixing so as to make our
analysis simple and clear. We develop the canonical Hamiltonian formalism based
on the gauge-fixed Lagrangian and perform the canonical quantization procedure
of the Hamiltonian system. Also, we obtain an arbitrary-rank massive spinor
field in dimensions via the Penrose transform of a twistor function
defined in the quantization procedure. Then we prove, in a twistorial fashion,
that the spin quantum number of a massive particle with rigidity can take only
non-negative integer values, which result is in agreement with the one shown
earlier by Plyushchay. Interestingly, the mass of the spinor field is
determined depending on the spin quantum number.Comment: 50 pages, Section 6 is revised, A reference added, minor corrections,
Published versio
Pathogenesis-Related Proteins in Grape
An overview of major pathogens and their control, plant defense mechanisms, and pathogenesis-related (PR) proteins and their roles in pathogen control is presented herein. Vitis vinifera, including wine grape and table grape, is one of the most valuable horticultural crops in the world because of its commercial use. However, V. vinifera cultivars are extremely susceptible to pathogens, particularly fungi and oomycetes, such as Botrytis cinerea and Plasmopara viticola, respectively. Plants have various defense mechanisms to counter these pathogens. One example is induced resistance, which involves the induction of the immune system in the event of a pathogen attack, including the generation of PR proteins. Some PR proteins possess antimicrobial activity. PR proteins are classified into 17 families, some of which are found in grape. Thus, their roles in grape have been actively studied. A new strategy to increase plant resistance to pathogens has been developed. A good understanding of grape defense mechanism through PR proteins is expected to open new doors to improve grape quality and yield by efficiently controlling pathogens in the future
Spread spectrum mobile communication experiment using ETS-V satellite
The spread spectrum technique is attractive for application to mobile satellite communications, because of its random access capability, immunity to inter-system interference, and robustness to overloading. A novel direct sequence spread spectrum communication equipment is developed for land mobile satellite applications. The equipment is developed based on a matched filter technique to improve the initial acquisition performance. The data rate is 2.4 kilobits per sec. and the PN clock rate is 2.4552 mega-Hz. This equipment also has a function of measuring the multipath delay profile of land mobile satellite channel, making use of a correlation property of a PN code. This paper gives an outline of the equipment and the field test results with ETS-V satellite
Shakespeare, Education, and British Imperialism: Prose Retellings of Shakespeare’s Plays in 1870-1920
早稲田大学博士(文学)早大学位記番号:新9606doctoral thesi
On the Evaluation of a Huggable Interface to Mediate Remote Affective Communication
Art and Design Research for the Future: Innovation and Art & Design ; September 26, 2017Conference: Tsukuba Global Science Week 2017Date: September 25-27, 2017Venue: Tsukuba International Congress CenterSponsored: University of Tsukub
Robust control of multi-jointed arm with a decentralized autonomous control mechanism
A decentralized autonomous control mechanism applied to the control of three dimensional manipulators and its robustness to partial damage was assessed by computer simulation. Decentralized control structures are believed to be quite robust to time delay between the operator and the target system. A 10-jointed manipulator based on our control mechanism was able to continue its positioning task in three-dimensional space without revision of the control program, even after some of its joints were damaged. These results suggest that this control mechanism can be effectively applied to space telerobots, which are associated with serious time delay between the operator and the target system, and which cannot be easily repaired after being partially damaged
Two Cases of Early Carcinoma of a Reconstructed Gastric Tube after Esophagectomy Treated Extendedly with Endoscopic Submucosal Dissection
We report two cases of gastric tube carcinoma (GTC) treated with endoscopic submucosal dissection (ESD) after esophagectomy. Case 1 was a 47-year-old woman who had received esophagectomy with reconstruction of the gastric tube (GT) for esophageal squamous cell carcinoma. Sixty-seven months later, endoscopy showed a carcinoma in the lower part of the GT. The removed tumor showed a 0-IIc lesion, 10 mm in diameter, diagnosed as a signet ring cell carcinoma limited to the mucosa. Case 2 was an 83-year-old woman who simultaneously underwent lower esophagectomy for basaloid-squamous cell carcinoma of the esophagus and colectomy for ascending colon carcinoma. Sixty-one months later, endoscopy showed a carcinoma in the middle part of the GT. The tumor removed by ESD showed a 0-IIa+IIc lesion, 50 mm in diameter, diagnosed as a moderately differentiated tubular adenocarcinoma limited to the mucosa. The clinicopathologic features of 48 Japanese cases, including Cases 1 and 2, with GTC were reviewed. An extended indication of endoscopic resection for gastric carcinoma was present in 12 (25%) including Cases 1 and 2. In conclusion, ESD may be safe for GTC; however, further investigations may be necessary to confirm the safety and curative potential of ESD for GTC.Article信州医学雑誌 59(2): 81-88(2011)departmental bulletin pape
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