242 research outputs found

    Effect of Slope Aspect on Arbuscular Mycorrhizal Colonization of Centipedegrass in a Hill Pasture

    Get PDF
    Arbuscular mycorrhizal fungi (AMF) form a symbiotic association with more than 80% of terrestrial plants and benefit their hosts principally by increasing uptake of nutrients. This is particularly important for phosphorus uptakes as fungal extraradical mycelium can access relatively immobile phosphate ions through an ability to grow beyond the phosphate depletion zone that rapidly develops around the root (Gosling et al. 2006). This symbiotic association is known to promote growth and improve drought and disease resistance of the host plants (Gosling et al. 2006). Centipedegrass (Eremochloa ophiuroides (Munro) Hack.) is a warm-season perennial that is native to central and southern China and is widely distributed in south-east Asia, southern USA, South America, West Indies, and parts of Africa and tropical north and east Australia (Islam and Hirata 2005). Centipedgegrass (CG) has been considered to be of potential value for use in low-input grassland systems in central to southern parts of Japan. An experiment conducted in a hill pasture in the mid-altitude region of Kyushu has shown that CG is well adapted to all slope aspects (north, east, south and west) despite the aspect differences in environmental conditions (Hirata et al. 2007). In this study, we monitored AM colonization of CG growing on the 4 slopes of the pasture to examine aspect differences in the grass–AMF association

    Bijections between topologies

    Get PDF
    A homeomorphism induces a natural bijection between the family of open sets. Weconsider the inverse problem and obtain an answer and counter examples

    Microdosimetric quantities of an accelerator-based neutron source used for boron neutron capture therapy measured using a gas-filled proportional counter

    Get PDF
    Boron neutron capture therapy (BNCT) is an emerging radiation treatment modality, exhibiting the potential to selectively destroy cancer cells. Currently, BNCT is conducted using a nuclear reactor. However, the future trend is to move toward an accelerator-based system for use in hospital environments. A typical BNCT radiation field has several different types of radiation. The beam quality should be quantified to accurately determine the dose to be delivered to the target. This study utilized a tissue equivalent proportional counter (TEPC) to measure microdosimetric and macrodosimetric quantities of an accelerator-based neutron source. The micro- and macro-dosimetric quantities measured with the TEPC were compared with those obtained via the the particle and heavy ion transport code system (PHITS) Monte Carlo simulation. The absorbed dose from events >20 keV/μm measured free in air for a 1-h irradiation was calculated as 1.31 ± 0.02 Gy. The simulated result was 1.41 ± 0.07 Gy. The measured and calculated values exhibit good agreement. The relative biological effectiveness (RBE) that was evaluated from the measured microdosimetric spectrum was calculated as 3.7 ± 0.02, similar to the simulated value of 3.8 ± 0.1. These results showed the PHITS Monte Carlo simulation can simulate both micro- and macro-dosimetric quantities accurately. The RBE was calculated using a single-response function, and the results were compared with those of several other institutes that used a similar method. However, care must be taken when using such a single-response function for clinical application, as it is only valid for low doses. For clinical dose ranges (i.e., high doses), multievent distribution inside the target needs to be considered

    超音波バイオテレメトリーシステムを応用した小型漁具深度モニタリングシステムの開発および性能試験

    Get PDF
    A system for real-time monitoring the depth of small fishing gear was developed using acoustic telemetry to improve the efficiency of fishing operations. The system consisted of an acoustic transmitter (pinger), an omni-directional hydrophone with a depressor, and a receiver. Using a pinger equipped with a depth sensor, a fisherman can confirm whether the fishing gear is at the intended depth. The battery of the developed pinger can be replaced easily for repeated use. The performance of the system was evaluated in a field experiment. The accuracy of measured depth was 0.4 m and was constant even if the pinger was moving. In the experiment, the system could successfully monitor the pinger depth every several second. The system was implemented in hairtail trolling to examine its effectiveness. The implementation experiments revealed some issues with the system, such as the effect of signal reflections or the installation method of the hydrophone. However, the system could monitor the depth of the fishing gear continuously in real time and it operated successfully without any problem during the fishing operation. Application of the developed system is expected to aid fishermen in adjusting the gear depth easily and accurately.小型漁具を対象とした,漁具深度をリアルタイムで測定・表示するシステムの開発を行った。開発したシステムの性能試験として,測定深度の精度評価とタチウオ漕釣り漁具への実装実験を行った。本システムの測定深度の精度は 0.4 m であった。実装実験では,漁具深度を連続的に測定・表示することにより,漁具深度の調整を支援することができた。本システムにより,効率的な漁具の操作が可能になる

    Effect of maximum grip strength on controlled force exertion measured by a computer-generated sinusoidal waveform in young adult males

    Get PDF
    Context: It is important to develop a method to accurately measure controlled force exertion (CFE). Objectives: This study aimed to examine the effect of maximum grip strength on CFE measured by a sinusoidal waveform in 81 right-handed young males aged 15-29 years. Methods: On the basis of grip strength measurements, participants were divided into the following three groups: low (males 20; mean age 19.5 years; standard deviation (SD) = 5.0 years), medium (males 41; mean age 22.8 years; SD = 4.2 years), and high (males 20; mean age 23.7 years; SD = 3.4 years). Participants adjusted the submaximal grip strength of the dominant hand with changes in the demand values that were displayed as a sinusoidal waveform with a frequency of 0.1 Hz on a computer screen. The abovementioned test was performed three times with a 1-min interval after one practice trial. Each trial lasted 40 s. The sum of the differences between the demand value and grip exertion strength value for 25 s was considered as the evaluation parameter. Results: Controlled force exertion values demonstrated insignificant correlations with age and maximum grip strength in all groups (r = 0.07; r = -0.12; p > 0.05). No significant differences were found between CFE mean scores that was adjusted for age and varying maximum grip strength in the three groups (F = 1.95; p > 0.05). Conclusions: Based on the sinusoidal waveform display, we inferred that maximum grip strength has little effect on CFE evaluation in young males. © 2014 Springer-Verlag Italia

    A Morphological Study of"Microfold" Cells of Lymphoid Aggregative Tissue in the Small Intestine of the Chicken

    Get PDF
    The morphology of lymphoid aggregative tissue of the small intestine was studied in the Japanese bantam chicken. Lymphoid aggregative tissue were composed of leaf-like villi unlike those in mammals. In the present study, these lymphoid aggregative tissues histologically were identified as Peyer\u27s patches. Light and electron microscopy of the covering epithelium of the Peyer\u27s patches showed that the cells had morphologically the same features of "Microfold" ("M") cells previously described in mammalian species. The authors demonstrated that the "M" cells of birds were not limited to the bursa of Fabricius, but also existed in the covering epithelium of the Peyer\u27s patches in the small intestine. The proportion of "M" cells enfolding lymphoid cells much in mature chickens (18%) than in mature rats (100%)

    Discovery of anti-inflammatory physiological peptides that promote tissue repair by reinforcing epithelial barrier formation

    Get PDF
    上皮バリアを形成するペプチドJIPの発見 --JIPは上皮組織修復に貢献する--. 京都大学プレスリリース. 2021-11-18.Epithelial barriers that prevent dehydration and pathogen invasion are established by tight junctions (TJs), and their disruption leads to various inflammatory diseases and tissue destruction. However, a therapeutic strategy to overcome TJ disruption in diseases has not been established because of the lack of clinically applicable TJ-inducing molecules. Here, we found TJ-inducing peptides (JIPs) in mice and humans that corresponded to 35 to 42 residue peptides of the C terminus of alpha 1-antitrypsin (A1AT), an acute-phase anti-inflammatory protein. JIPs were inserted into the plasma membrane of epithelial cells, which promoted TJ formation by directly activating the heterotrimeric G protein G13. In a mouse intestinal epithelial injury model established by dextran sodium sulfate, mouse or human JIP administration restored TJ integrity and strongly prevented colitis. Our study has revealed TJ-inducing anti-inflammatory physiological peptides that play a critical role in tissue repair and proposes a previously unidentified therapeutic strategy for TJ-disrupted diseases

    Heyndrickxia coagulans strain SANK70258 suppresses symptoms of upper respiratory tract infection via immune modulation: a randomized, double-blind, placebo-controlled, parallel-group, comparative study

    Get PDF
    Probiotic consumption strongly influences local intestinal immunity and systemic immune status. Heyndrickxia coagulans strain SANK70258 (HC) is a spore-forming lactic acid bacterium that has immunostimulatory properties on peripheral tissues. However, few reports have examined the detailed effectiveness of HC on human immune function and its mechanism of action. Therefore, we conducted a randomized, double-blind, placebo-controlled, parallel-group study to comprehensively evaluate the effects of HC on immunostimulatory capacity, upper respiratory tract infection (URTI) symptoms, and changes in intestinal organic-acid composition. Results of a questionnaire survey of URTI symptoms showed that runny nose, nasal congestion, sneezing, and sore throat scores as well as the cumulative number of days of these symptoms were significantly lower in the HC group than in the placebo group during the study period. Furthermore, the salivary secretory immunoglobulin A (sIgA) concentration was significantly higher, and the natural killer (NK) cell activity tended to be higher in the HC group than in the placebo group. In addition, we performed an exposure culture assay of inactivated influenza virus on peripheral blood mononuclear cells (PBMCs) isolated from the blood of participants in the HC and placebo groups. Gene-expression analysis in PBMCs after culture completion showed that IFNα and TLR7 expression levels were significantly higher in the HC group than in the placebo group. In addition, the expression levels of CD304 tended to be higher in the HC group than in the placebo group. On the other hand, the HC group showed a significantly higher increase in the intestinal butyrate concentration than the placebo group. HC intake also significantly suppressed levels of IL-6 and TNFα produced by PBMCs after exposure to inactivated influenza virus. Collectively, these results suggest that HC activated plasmacytoid dendritic cells expressing TLR7 and CD304 and strongly induced IFNα production, subsequently activating NK cells and increasing sIgA levels, and induced anti-inflammatory effects via increased intestinal butyrate levels. These changes may contribute to the acquisition of host resistance to viral infection and URTI prevention
    corecore