Bilinearization of Discrete Soliton Equations and Singularity Confinement

Bilinear forms for some nonlinear partial difference equations(discrete soliton equations) are derived based on the results of singularity confinement. Using the bilinear forms, the N-soliton and algebraic solutions of the discrete potential mKdV equation are constructed.Comment: 14 pages, LaTe

Multiple hepatic sclerosing hemangioma mimicking metastatic liver tumor successfully treated by laparoscopic surgery: Report of a case

AbstractIntroductionHepatic sclerosing hemangioma is a very rare benign tumor, characterized by fibrosis and hyalinization occurring in association with degeneration of a hepatic cavernous hemangioma. We report here a rare case of multiple hepatic sclerosing hemangioma mimicking metastatic liver tumor that was successfully treated using laparoscopic surgery.Presentation of caseA 67-year-old woman with multiple liver tumors underwent single-incision laparoscopic sigmoidectomy under a diagnosis of advanced sigmoid cancer with multiple liver metastases. Examination of surgical specimens of sigmoid colon revealed moderately differentiated adenocarcinoma invading the serosa, and no lymph node metastases. Serum levels of carcinoembryonic antigen and carbohydrate antigen 19-9 remained within normal limits throughout the course. Two months after sigmoidectomy, the patient underwent laparoscopic partial hepatectomy of S1 and S6 of the liver and cholecystectomy. Histopathological examination showed that the tumors mainly comprised hyalinized tissue and collagen fibers with sporadic vascular spaces on hematoxylin and eosin-stained sections, yielding a diagnosis of multiple hepatic sclerosing hemangioma. No evidence of recurrence has been seen as of 21 months postoperatively.DiscussionDifferentiating multiple sclerosing hemangiomas from metastatic liver tumors was quite difficult because the radiological findings were closely compatible with liver metastases. Laroscopic hepatectomy provided less blood loss, a shorter duration of hospitalization, and good cosmetic results.ConclusionSclerosing hemangioma should be included among the differential diagnoses of multiple liver tumors in patients with colorectal cancer. Laparoscopic hepatectomy is useful for diagnostic therapy for undiagnosed multiple liver tumors

Study on Flow Characteristics Downstream of Annular Inlet Guide Vanes

ABSTRACT The main objectives of the present study are to identify the dominant parameters responsible for the generation of unsteady flow, determine the conditions under which flow oscillations are produced and the relation between the flow characteristics and the number of vanes with identical solidity. The flow instabilities downstream of inlet guide vanes (IGV) are clarified experimentally and by numerical simulation. The conditions for the onset of flow instability, including the number of cells and the oscillation characteristics of the unsteady flow, are discussed based on measured pressure fluctuations and the propagating angular velocity ratio of the instability for various radius ratios (r3/r2). The effectiveness of adjusting the number of vanes to control the flow instabilities is also discussed. INTRODUCTION Variable inlet guide vanes (IGV), which are a type of swirling flow generator, are installed at the inlet of centrifugal compressors to reduce the inlet mach number of the rotor blades. Under lower flow rates, the vane angle (β2) referring t

Recurrent Ascending Colon Cancer Manifesting as Inferior Vena cava Thrombus

We report an extremely rare case of recurrent ascending colon cancer manifesting as inferior vena cava (IVC) thrombus. A 77-year-old woman previously diagnosed with ascending colon cancer underwent right hemicolectomy with lymph node dissection. Though the tumor invaded the retroperitoneum and involved the right ovarian artery and vein, curative operation was performed. The patient took 5-FU p.o. Two and a half years later, tumor thrombus in the IVC extending into the right atrium was incidentally found and diagnosed as recurrence of colon cancer by biopsy. RF-induced hyperthermia using 5-FU and CDDP i.v. was immediately performed, but she died after 6 months because of multiple liver and pulmonary metastases. In treating colon cancers invading the retroperitoneum, it should be recalled that some cases recur as tumor thrombus in the IVC and that close follow-up is therefore necessary

The hrp genes of Pseudomonas cichorii are essential for pathogenicity on eggplant but not on lettuce

Pseudomonas cichorii causes necrotic lesions in eggplant and rot in lettuce. Through transposon insertion into P. cichorii strain SPC9018 we produced two mutants, 4-57 and 2-99, that lost virulence on eggplant but not lettuce. Analyses showed that a transposon was inserted into the hrpG gene in 4-57 and the hrcT gene in 2-99. Nucleotide sequences of the hrp genes of SPC9018 are homologous to those of Pseudomonas viridiflava BS group strains. The pathogenicity of 4-57 on eggplant was restored by transformation with an hrpF operon, originating from either SPC9018 or the BS group member P. viridiflava strain 9504 (Pv9504). These data suggested the involvement of hrp genes in the pathogenicity of SPC9018 on eggplant, and functional conservation of hrpF operons between SPC9018 and Pv9504. Both the hrpS mutant and the hrpL mutant were unable to cause necrotic lesions on eggplant leaves but retained their pathogenicity against lettuce. These results suggest that the pathogenicity of P. cichorii is hrp-dependent in eggplant, but not in lettuce

An NLR paralog Pit2 generated from tandem duplication of Pit1 fine-tunes Pit1 localization and function

NLR family proteins act as intracellular receptors. Gene duplication amplifies the number of NLR genes, and subsequent mutations occasionally provide modifications to the second gene that benefits immunity. However, evolutionary processes after gene duplication and functional relationships between duplicated NLRs remain largely unclear. Here, we report that the rice NLR protein Pit1 is associated with its paralogue Pit2. The two are required for the resistance to rice blast fungus but have different functions: Pit1 induces cell death, while Pit2 competitively suppresses Pit1-mediated cell death. During evolution, the suppression of Pit1 by Pit2 was probably generated through positive selection on two fate-determining residues in the NB-ARC domain of Pit2, which account for functional differences between Pit1 and Pit2. Consequently, Pit2 lost its plasma membrane localization but acquired a new function to interfere with Pit1 in the cytosol. These findings illuminate the evolutionary trajectory of tandemly duplicated NLR genes after gene duplication

The Stellar Abundances for Galactic Archaeology (SAGA) Database II - Implications for Mixing and Nucleosynthesis in Extremely Metal-Poor Stars and Chemical Enrichment of the Galaxy

We discuss the characteristics of known extremely metal-poor (EMP) stars in the Galaxy using the Stellar Abundances for Galactic Archaeology (SAGA) database (Suda et al. 2008, PASJ, 60, 1159).The analyses of carbon-enhanced stars in our sample suggest that the nucleosynthesis in AGB stars can contribute to the carbon enrichment in a different way depending on whether the metallicity is above or below [Fe/H] ~ -2.5, which is consistent with the current models of stellar evolution at low metallicity. We find the transition of the initial mass function at [Fe/H] ~ -2 in the viewpoint of the distribution of carbon abundance and the frequency of carbon-enhanced stars. For observed EMP stars, we confirmed that some, not all, of observed stars might have undergone at least two types of extra mixing to change their surface abundances. One is to deplete the lithium abundance during the early phase of red giant branch. Another is to decrease the C/N ratio by one order of magnitude during the red giant branch phase. Observed small scatters of abundances for alpha-elements and iron-group elements suggest that the chemical enrichment of our Galaxy takes place in a well-mixed interstellar medium. We find that the abundance trends of alpha-elements are highly correlated with each other, while the abundances of iron-group elements are subject to different slopes relative to the iron abundance. This implies that the supernova yields of alpha-elements are almost independent of mass and metallicity, while those of iron-group elements have a metallicity dependence or mass dependence with the variable initial mass function.The occurrence of the hot bottom burning in the mass range of 5 <~ M / Msun <~ 6 is consistent with the initial mass function of the Galaxy peaked at ~ 10 - 12 Msun to be compatible with the statistics of carbon enhanced stars with and without s-process element (truncated)Comment: 35 pages, 27 figures, 6 tables, accepted by MNRAS, database to reproduce figures is available at http://saga.sci.hokudai.ac.j