Solution Generating Technique for Noncommutative Orbifolds

We propose the relationships between the noncommutative solitons and the (fractional) D-branes on the C^2/Z_n orbifold and extend the solution generating technique for the orbifold. As applications, we determine how tachyon condensations occur in various D-Dbar systems on the orbifolds. The calculations give results consistent with BSFT. The extended solution generating technique enables us to calculate more general decay modes of D-Dbar systems.Comment: 13 pages, 1 figur

Dynamic and Decentralized Storage Load Balancing with Analogy to Thermal Diffusion for P2P File Sharing

In this paper we propose a file replication scheme inspired by a thermal diffusion phenomenon for storage load balancing in unstructured peer-to-peer (P2P) file sharing networks. The proposed scheme is designed such that the storage utilization ratios of peers will be uniform, in the same way that the temperature in a field becomes uniform in a thermal diffusion phenomenon. The proposed scheme creates replicas of files in peers probabilistically, where the probability is controlled by using parameters that can be used to find the trade-off between storage load balancing and search performance in unstructured P2P file sharing networks. First, we show through theoretical analysis that the statistical behavior of the storage load balancing controlled by the proposed scheme has an analogy with the thermal diffusion phenomenon. We then show through simulation that the proposed scheme not only has superior performance with respect to balancing the storage load among peers (the primary objective of the present proposal) but also allows the performance trade-off to be widely found. Finally, we qualitatively discuss a guideline for setting the parameter values in order to widely find the performance trade-off from the simulation results

Pinpoint-fluorinated polycyclic aromatic hydrocarbons (F-PAHs): Syntheses of difluorinated subfamily and their properties

Difluorinated polycyclic aromatic hydrocarbons (PAHs) containing three to five benzene rings were systematically synthesized by the Pd(II)-catalyzed Friedel–Crafts-type cyclization of 1,1,2-trifluoro- and 1,1-difluoro-1-alkenes and the In(III)-catalyzed tandem cyclization of bis(1,1-difluoroallene)s. Using an array of the difluorinated PAHs that were obtained and previously reported monofluorinated PAHs, the physical properties of the pinpoint-fluorinated PAHs were investigated. (i) The 19F NMR signals of the bay-region fluorine atoms were shifted downfield by ca. 8–14 ppm for vic-difluorinated PAHs and ca. 11–19 ppm for non-vic-difluorinated and monofluorinated PAHs. (ii) The introduction of fluorine into PAH molecules increased their solubilities in organic solvents, which was best exemplified by the high solubilities of 6,7-difluoropicene (5.4 wt%) and 6-fluoropicene (5.3 wt%) in THF. (iii) The HOMO–LUMO energy gaps of the pinpoint-fluorinated PAHs were smaller than that of the corresponding fluorine-free PAH (i.e., picene) by 0.02–0.26 eV, and the HOMO and LUMO energy levels were lowered by 0.10–0.22 eV and 0.12–0.41 eV, respectively

Functional tooth number and mortality

Aim: Previous studies on the association between intraoral conditions and mortality in community-dwelling older individuals reported that fewer present teeth (PT) are significant risk factors for mortality. However, how the number of PT relative to the number of functional teeth (FT), including both present and rehabilitated teeth, influences mortality has not been investigated fully. This study examined the impact of the number of FT on mortality among community-dwelling Japanese older adults. Methods: This study was a retrospective, observational and population-based follow-up study, which examined 1188 older individuals who participated in an annual geriatric health examination from 2009 to 2015. The average follow-up period was 1697.0 ± 774.5 days. The primary outcome was all-cause mortality at follow-up. The numbers of PT and FT of each participant were counted during an oral examination. In addition, demographics, clinical variables, blood nutrient markers, physical functions and perceived masticatory function were measured. Results: Kaplan–Meier analysis, followed by a log-rank test, revealed that fewer PT (P < 0.001) and FT (P = 0.002) were significantly associated with a reduced survival rate. Cox's proportional hazard analysis indicated that the number of FT, but not the number of PT, was a significant independent mortality risk factor after adjusting for demographics, clinical variables, nutrient markers and physical functioning (P = 0.036, hazard ratio: 2.089). Conclusions: Current results suggest that the number of FT more strongly predicts all-cause mortality than the number of PT among community-dwelling older adults. Further studies are necessary to consider the confounding of socioeconomic status and disability status

Number of functional teeth more strongly predicts all‐cause mortality than number of present teeth in Japanese older adults

Aim Previous studies on the association between intraoral conditions and mortality in community‐dwelling older individuals reported that fewer present teeth (PT) are significant risk factors for mortality. However, how the number of PT relative to the number of functional teeth (FT), including both present and rehabilitated teeth, influences mortality has not been investigated fully. This study examined the impact of the number of FT on mortality among community‐dwelling Japanese older adults. Methods This study was a retrospective, observational and population‐based follow‐up study, which examined 1188 older individuals who participated in an annual geriatric health examination from 2009 to 2015. The average follow‐up period was 1697.0 ± 774.5 days. The primary outcome was all‐cause mortality at follow‐up. The numbers of PT and FT of each participant were counted during an oral examination. In addition, demographics, clinical variables, blood nutrient markers, physical functions and perceived masticatory function were measured. Results Kaplan–Meier analysis, followed by a log‐rank test, revealed that fewer PT (P  Conclusions Current results suggest that the number of FT more strongly predicts all‐cause mortality than the number of PT among community‐dwelling older adults. Further studies are necessary to consider the confounding of socioeconomic status and disability status

Impact of number of functional teeth on independence of Japanese older adults

Aim To examine the relationship between the number of present and functional teeth at baseline and future incidence of loss of independence. Methods Participants were community-dwelling older individuals who participated in a comprehensive geriatric health examination conducted in Kusatsu town, Japan, between 2009 and 2015. The primary endpoint was the incidence of loss of independence among participants, defined as the first certification of long-term care insurance in Japan. The numbers of present and functional teeth at baseline were determined via an oral examination. Demographics, clinical variables (e.g., history of chronic diseases and psychosocial factors), blood nutritional markers, physical functions, and perceived masticatory function were assessed. Results This study included 1121 individuals, and 205 individuals suffered from loss of independence during the follow-up period. Kaplan–Meier estimates of loss of independence for participants with smaller numbers of present and functional teeth were significantly greater than for those with larger numbers of teeth. Cox proportional hazard analyses indicated that a smaller number of present teeth was not a significant risk factor after adjusting for demographic characteristics. However, the number of functional teeth was a significant risk factor after the adjustment (hazard ratio: 1.975 [1.168–3.340]). Additionally, higher hazard ratios were observed in other adjusted models, but they were not statistically significant. Conclusions The number of functional teeth may be more closely related to the future incidence of loss of independence than the number of present teeth. This novel finding suggests that prosthodontic rehabilitation for tooth loss possibly prevents the future incidence of this life-event