336 research outputs found
Reduced Density Matrices and Topological Order in a Quantum Dimer Model
Resonating valence bond (RVB) liquids in two dimensions are believed to
exhibit topological order and to admit no local order parameter of any kind.
This is a defining property of "liquids" but it has been explicitly confirmed
only in a few exactly solvable models. In this paper, we investigate the
quantum dimer model on the triangular lattice. It possesses an RVB-type liquid
phase, however, for which the absence of a local order parameter has not been
proved. We examine the question numerically with a measure based on reduced
density matrices. We find a scaling of the measure which strongly supports the
absence of any local order parameter.Comment: 6 pages, 3 figures. To appear in J. Phys.: Condens. Matter
(Proceedings of "Highly Frustrated Magnets", Osaka (Japan), August 2006).
Version 2: improved figures containing new data and minor changes in the tex
Duodenal Carcinoma from a Duodenal Diverticulum Mimicking Pancreatic Carcinoma
An 81-year-old man was found to have a pancreatic head tumor on abdominal computed tomography (CT) performed during a follow-up visit for sigmoid colon cancer. The tumor had a diameter of 35mm on the CT scan and was diagnosed as pancreatic head carcinoma T3N0M0. The patient was treated with pylorus-preserving pancreaticoduodenectomy. Histopathological examination showed that the tumor had grown within a hollow structure, was contiguous with a duodenal diverticulum, and had partially invaded the pancreas. Immunohistochemistry results were as follows:CK7 negative, CK20 positive, CD10 negative, CDX2 positive, MUC1 negative, MUC2 positive, MUC5AC negative, and MUC6 negative. The tumor was diagnosed as duodenal carcinoma from the duodenal diverticulum. Preoperative imaging showed that the tumor was located in the head of the pancreas and was compressing the common bile duct, thus making it appear like pancreatic cancer. To the best of our knowledge, this is the second report of a case of duodenal carcinoma from a duodenal diverticulum mimicking pancreatic carcinoma
Seeking sustainable potentials in an urban community in Kobe, Japan
Thesis (M. Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 1997.Includes bibliographical references (p. 76-77).Sustainability was once inherent in many communities of the pre-modern society; however, it has been lost under the progress of the modern society through humankind's rationalized and short-term visions in pursuing more comfort and convenience in their life. Consequently, humankind is gradually heading toward destruction of not only their own systems, but also whole systems on the earth. In the context of the modern society, how can sustainability in communities be regained to promise the future of humankind, the earth, and the universe. The intent of this thesis is to investigate the possible forms and systems of urban communities, whose compact forms and efficient social and physical systems have more potentials to sustainability than those of suburban types' do, while urban communities have been major consumers of energy and resources and major producers of various kinds of pollution and wastes. In order to explore this, the thesis seeks sustainable potentials in an urban inner-city community in Kobe, Japan and develops a sustainable community with proposals of systems and community design in the scale of urban design, a block, streets, and architecture. The site is located in Takatori-Higashi district in the city of Kobe where was totally devastated by the major earthquake in January, 1995 and where is needed to be restructured and reconstructed soon. As the outcome of th is exploration, this sustainable community will establish some possible answers to the question of how the communities for next generations should be and address possible issues of sustainable communities to be further explored and discussed.by Masaki Furukawa.M.Arch
Hierarchical Neural Memory Network for Low Latency Event Processing
This paper proposes a low latency neural network architecture for event-based
dense prediction tasks. Conventional architectures encode entire scene contents
at a fixed rate regardless of their temporal characteristics. Instead, the
proposed network encodes contents at a proper temporal scale depending on its
movement speed. We achieve this by constructing temporal hierarchy using
stacked latent memories that operate at different rates. Given low latency
event steams, the multi-level memories gradually extract dynamic to static
scene contents by propagating information from the fast to the slow memory
modules. The architecture not only reduces the redundancy of conventional
architectures but also exploits long-term dependencies. Furthermore, an
attention-based event representation efficiently encodes sparse event streams
into the memory cells. We conduct extensive evaluations on three event-based
dense prediction tasks, where the proposed approach outperforms the existing
methods on accuracy and latency, while demonstrating effective event and image
fusion capabilities. The code is available at https://hamarh.github.io/hmnet/Comment: Accepted to CVPR 202
Ethanol Extract of Chinese Propolis Facilitates Functional Recovery of Locomotor Activity after Spinal Cord Injury
An ethanol extract of Chinese propolis (EECP) was given intraperitoneally to rats suffering from hemitransection of half of their spinal cord (left side) at the level of the 10th thoracic vertebra to examine the effects of the EECP on the functional recovery of locomotor activity and expression of mRNAs of inducible nitric oxide (NO) synthase (iNOS) and neurotrophic factors in the injury site. Daily administration of EECP after the spinal cord injury ameliorated the locomotor function, which effect was accompanied by a reduced lesion size. Furthermore, the EECP suppressed iNOS gene expression, thus reducing NO generation, and also increased the expression level of brain-derived neurotrophic factor and neurotrophin-3 mRNAs in the lesion site, suggesting that the EECP reduced the inflammatory and apoptotic circumstances through attenuation of iNOS mRNA expression and facilitation of mRNA expression of neurotrophins in the injured spinal cord. These results suggest that Chinese propolis may become a promising tool for wide use in the nervous system for reducing the secondary neuronal damage following primary physical injury
13C-NMR Spectroscopic Study on Chemical Species in Piperazine−Amine−CO2−H2O System before and after Heating
AbstractChemical reactions associated with the absorption of CO2 into aqueous solutions of blends of piperazine (PZ) with N- methyldiethanolamine (MDEA), etc. were studied by 13C-NMR spectroscopy. The coexistence of PZ and MDEA enhanced the initial apparent rate of HCO3−/CO2−3 formation. This result can be explained by considering that PZ−monocarbamate rapidly formed works as an organocatalyst in the formation reaction of HCO−3. Concentration changes of chemical species in CO2-absorbed aqueous amine solutions upon heating (80°C, 30min) were studied by 13C-NMR spectroscopy. Carbon dioxide regeneration originates mainly from HCO3−/CO3, and not form carbamate and carbonate
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