F-Rationality of Rees Algebras Hara, Nobuo; Watanabe, Kei-ichi; Yoshida, Ken-ichi
Journal of algebra,
01/2002, Letnik:
247, Številka:
1
Journal Article
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Odprti dostop
In this paper, using the notion of the tight integral closure, we will give a criterion for F-rationality of Rees algebras of m-primary ideals in a Cohen–Macaulay local ring. As its application, we ...prove the following results: (1) In dimension two, if A is F-rational and I is integrally closed, then the Rees algebra R(I) is F-rational. On the other hand, in higher dimensions, we construct many examples of Cohen–Macaulay, normal Rees algebras which are not F rational. (2) If both A and R(I) are F-rational, then so is the extended Rees algebra R′(I). (3) If R(I) is F-rational and a(G(I))≠−1, then A is F-rational.
On the other hand, using resolution of singularities, we will prove that a two-dimensional rational singularity always admits F-rational Rees algebras. In particular, this theorem gives another way than that devised by Watanabe (1997, J. Pure Appl. Algebra122, 323–328) to construct counterexamples to the Boutot-type theorem for F-rational rings.
A clinical study of weekly administration of CPT-11, a semi-synthetic derivative of Camptothecin, was performed in patients with advanced lung cancer to determine the optimal dose for a weekly single ...dose schedule. Sixteen out of 19 patients enrolled were evaluable. The starting dose was 50 mg/m2 and gradually escalated to 100, 125 and 150 mg/m2. CPT-11 was given by intravenous infusion for 90 minutes every week. The maximum tolerated dose for this schedule was estimated to be 125 mg/m2. The dose-limiting toxicity was leukopenia with median nadir of 2,900/mm3, median day to nadir of 21, and median day to recovery of 7. Other major toxicity was gastrointestinal upset, but was mild and tolerable. Objective tumor responses were observed in four patients, three with non-small cell carcinoma and one with double cancer (small and non-small cell carcinoma). The responding patients were treated at a dosage of 100 mg/m2 or more. The recommended dose for a phase II study is considered to be 100 mg/m2 iv infusion for a weekly single-dose schedule.
This paper proposes an abundance index of immigrants in exploited migratory populations. The abundance index is derived, as an example of adult yellowtail population immigrating into coastal areas ...along the main land of Japan in the Japan Sea, on the following assumptions. First, the adult yellowtail population immigrates into the Sea through the Straits of Tsushima and migrates northward along the main land. Second, fishing effort is constant in each fishing area over a period in question. Third, exploited rate is independent of the size of the im-migrant population in each area. Here the exploited rate in an area is defined as the ratio of catch to the immigrant population size into coastal areas along the main land. Finally, the rate in each area is independent of the ones in others and follows a log-normal distribution. As a numerical example, the derived index is applied to the adult yellowtail population along the main land of Japan in the Japan Sea. In addition, this paper compared the index with the one proposed by Hara.
This paper examines mechanisms of yearly fluctuations in catch of adult yellowtail by set net fishery along the costal area of the Sea of Japan. The author studies relations between changes in ...position of the cold-water off the coast and fishing condition of adult yellowtail along the coast, using the hydrographic data from monthly observation in the Sea of Japan. In spring, abundant catch of adult yellowtail tends to occur along the coast of Yamaguchi Pref. when the position of the Shimane cold-water deflects off the coast. In winter, on the con-trary, abundant catch tends to occur when the position of the Shimane cold-water deflects on the coast. In winter, abundant catch also tends to appear along the coast of the western part of Waka-sa Bay when the position of the Wakasa cold-water deflects on the coast. In spring and early summer, fewer adult yellowtail migrate to the north of Noto Pen. when the cold-water deflects on Noto Pen.
To compare motor and sensory capabilities for fusion of vertical disparities at different angles of horizontal vergence in healthy humans.
Eye movements were recorded from both eyes of 12 healthy ...subjects using three-axis search coils. The stimulus was a cross (+) (3.4 x 3.2 degrees , vertically and horizontally, respectively) presented to each eye with a stereoscopic display. Vertical disparities were introduced by adjusting the vertical position of the cross in front of one eye. The disparity was increased in small increments (0.08 degrees ) every 8 seconds. Viewing was defined as "near" if there was a horizontal disparity that elicited 6 degrees to 15 degrees convergence, depending on the subject's capability for horizontal fusion; viewing was defined as "far" at 1 degrees convergence. Maximum motor (measured), sensory (stimulus minus motor), and total (motor plus sensory) vertical fusion were compared.
In 9 (75%) of 12 subjects the maximum total vertical fusion was more in near than in far viewing. The three who did not show this effect had relatively weak horizontal fusion. For the entire group, the motor component differed significantly between far (mean, 1.42 degrees ) and near (mean, 2.13 degrees). Total vertical fusion capability (motor plus sensory) also differed significantly between far (mean, 1.68 degrees ) and near (mean, 2.39 degrees ). For the sensory component there was no difference between between far (mean, 0.268 degrees ) and near (mean, 0.270 degrees ). As vertical disparity increased in a single trial, however, there was a small gradual increase of the contribution of the sensory component to vertical fusion.
Vertical fusion capability usually increases with convergence. This increase is caused primarily by an increase in the motor component. There is a gradual but small increase in the sensory component as target disparity slowly increases.
Efficacy of interferon-alpha2b (IFN) + ribavirin (IFN/RBV) combination in patients with high plasma hepatitis C virus (HCV) is very poor. Dysregulated CD4+ /CD8+ T cells is involved in both impaired ...cell-mediated immunity and resistance to IFN. Adsorptive granulocytes and monocytes apheresis (GMA) can remove infected leucocytes which are extrahepatic HCV reservoirs and also has been associated with intriguing immunomodulation and increases in CD4+ T cells. Our aim was to see if GMA enhances the efficacy of IFN/RBV. Twenty-four patients, 13 IFN resistant and 11 IFN naive were enrolled. Seventeen were genotype 1b and 7 were 2a or 2b. Mean plasma HCV-RNA was 612.9 (100-850) kIU/mL and alanine aminotransferase, 108 (41-373) U/L. GMA was performed with Adacolumn at one session/day for five consecutive days and IFN/RBV was started within 24 h after the last GMA session. Daily 6 million units of IFN, six times/week for 2 weeks and then three times/week for 22 weeks were given with RBV (600-800 mg/day/patient). Patients were followed for 6 months. GMA was associated with a significant increase in lymphocyte counts, complement activation fragment C3a and falls in tissue necrosis factor-alpha, and IL-8 produced by peripheral blood leucocytes. At week 24, 20 of 24 patients (83%) were HCV negative and by end of follow-up (week 49), the remission was sustained in 14 of 24 patients (58%) including 100% of patients with 2a or 2b. In conclusion, enhanced efficacy of IFN/RBV following GMA might be attributed to a more efficient immune function and a renewed IFN signaling towards HCV.
Efficacy of interferon‐
α
2b (IFN) + ribavirin (IFN/RBV) combination in patients with high plasma hepatitis C virus (HCV) is very poor. Dysregulated CD4+ /CD8+ T cells is involved in both impaired ...cell‐mediated immunity and resistance to IFN. Adsorptive granulocytes and monocytes apheresis (GMA) can remove infected leucocytes which are extrahepatic HCV reservoirs and also has been associated with intriguing immunomodulation and increases in CD4+ T cells. Our aim was to see if GMA enhances the efficacy of IFN/RBV. Twenty‐four patients, 13 IFN resistant and 11 IFN naive were enrolled. Seventeen were genotype 1b and 7 were 2a or 2b. Mean plasma HCV‐RNA was 612.9 (100–850) kIU/mL and alanine aminotransferase, 108 (41–373) U/L. GMA was performed with Adacolumn at one session/day for five consecutive days and IFN/RBV was started within 24 h after the last GMA session. Daily 6 million units of IFN, six times/week for 2 weeks and then three times/week for 22 weeks were given with RBV (600–800 mg/day/patient). Patients were followed for 6 months. GMA was associated with a significant increase in lymphocyte counts, complement activation fragment C3a and falls in tissue necrosis factor‐alpha, and IL‐8 produced by peripheral blood leucocytes. At week 24, 20 of 24 patients (83%) were HCV negative and by end of follow‐up (week 49), the remission was sustained in 14 of 24 patients (58%) including 100% of patients with 2a or 2b. In conclusion, enhanced efficacy of IFN/RBV following GMA might be attributed to a more efficient immune function and a renewed IFN signaling towards HCV.
A miniature vibrating hollow-fiber filtration device, in which a hollow-fiber cartridge mounted on a bridge held by two plate springs is vibrated to axial direction by a vibration motor, has been ...developed. The device can restrain the deposition of particles on the membrane surface by the vibration. A device, which has two hollow-fiber (length of 190 mm, an inside diameter of 1 mm and pore diameter of 0.1 *mm), was tested at a membrane vibration frequency of 40 Hz and an amplitude of 2.5 mm p-p. During the test the liquid (Kaolin suspension; turbridity: 1000) was filtered through the membrane for two weeks. It was found that the rate of permeation is almost constant after the test. However, when it was not vibrated, the end permeation rate was one quarter of the rate when vibrated.
Goblet cell metaplasia is an important morphological feature in the airways of patients with chronic airway diseases; however, the precise mechanisms that cause this feature are unknown. We ...investigated the role of endogenous platelet-activating factor (PAF) in airway goblet cell metaplasia induced by cigarette smoke in vivo. Guinea pigs were exposed repeatedly to cigarette smoke for 14 consecutive days. The number of goblet cells in each trachea was determined with Alcian blue-periodic acid-Schiff staining. Differential cell counts and PAF levels in bronchoalveolar lavage fluid were also evaluated. Cigarette smoke exposure significantly increased the number of goblet cells. Eosinophils, neutrophils, and PAF levels in bronchoalveolar lavage fluid were also significantly increased after cigarette smoke. Treatment with a specific PAF receptor antagonist, E-6123, significantly attenuated the increases in the number of airway goblet cells, eosinophils, and neutrophils observed after cigarette smoke exposure. These results suggest that endogenous PAF may play a key role in goblet cell metaplasia induced by cigarette smoke and that potential roles exist for inhibitors of PAF receptor in the treatment of hypersecretory airway diseases.
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