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71.
OBJECTIVE: To compare the interaction of endogenous ADP with collagen and thromboxane A(2) (TXA(2)) during collagen-induced platelet aggregation between platelets from healthy cattle and those with Chediak-Higashi syndrome (CHS). POPULATION SAMPLE: Platelets harvested from blood samples from healthy Japanese Black cattle and those with CHS. PROCEDURES: Aggregation of gel-filtered platelets; release of ATP-ADP; and generation of thromboxane B(2) (TXB(2)), a metabolite of TXA(2), were measured. RESULTS: The potency of collagen to induce aggregation in platelets of cattle with CHS (ie, CHS platelets) was less than a tenth of that in platelets of healthy cattle (ie, control platelets). Platelet aggregation induced by collagen at an intermediate concentration depended on the coexistence of ADP and TXA(2), suggesting that released ADP cannot cause platelet aggregation by itself. Collagen-induced ADP release was markedly decreased, whereas TXB(2) production was slightly low in CHS platelets, compared with that in control platelets. A combination of subthreshold amounts of ADP and 9,11-dideoxy-9alpha, 11alpha-methano-epoxy-prostaglandin F(2) (U46619), a TXA(2) analogue, caused platelet aggregation. Similarly, a combination of subthreshold amounts of collagen and ADP caused platelet aggregation, whereas collagen and U46619 were not synergistic. CONCLUSIONS AND CLINICAL RELEVANCE: Deficient ADP release ensuing from the delta-storage pool deficiency in platelets from cattle with CHS resulted in reduction of collagen-induced platelet aggregation, through attenuation of synergism between TXA(2) and ADP and between ADP and collagen. Furthermore, results of the study reported here indicated that TXA(2) was important for aggregation of bovine platelets.  相似文献   
72.
For improving the economic and environmental sustainability of fish farming, it is necessary to optimize feeding regimes. From this viewpoint, we monitored the growth and mortality of red sea bream (Pagrus major), C and N fluxes and sediment chemistry at 2 commercial fish cages; cage 1 (conventional satiation feeding) and cage 2 (restricted feeding: same feeding frequency but 18% reduction in the feed amount) for 276 days. The similar specific growth rates (0.43% in cage 1 and 0.39% in cage 2) but different feed conversion efficiencies (0.54 in cage 1 and 0.62 in cage 2) and mortality (> 2-times higher in cage 1) between the 2 cages, indicate overfeeding in cage 1 culture. Elemental and stable isotopic analyses of sediment trap materials enabled the quantification of waste feed- and fecal matter-derived organic matter (OM) separately. The results shows that (1) aquaculture-derived OM comprised most of the fish-farm settling OM, excluding the period from January to April, when natural OM often accounted for a half of the bulk OM, (2) there was a difference in the seasonal trend between the fluxes of waste feed and fecal matter, and (3) there were no differences in the percentage compositions and fluxes of waste feed and fecal matter between the 2 cages. The isotopic analysis showed that the waste feed-derived OM in the sediment below cage 2 was 24% less than that below cage 1, suggesting effect of restricted feeding. Determining the relative amount of waste feed and fecal matter in settling and sedimentary OM is an effective method to evaluate the optimum feeding regime.  相似文献   
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74.
The occurrence of morphologically immature megalopae, which retain zoeal features such as dorsal spines and furcae of telson, is closely correlated with larval mass mortality during seed production of the swimming crab Portunus trituberculatus in Japanese hatcheries. To determine the cause of immature megalopal morphology, zoeae were reared with various supplementary schedules and density of diets (rotifer, Artemia and phytoplanktons including Chlorella vulgaris and Nannochloropsis oculata). In addition, to assess the relationship between immature morphology and endocrine control, the effect of causative dietary factor was compared with the effect of eyestalk ablation at various timing during zoeal development. Megalopal immature morphology was more distinct in Chlorella‐supplemented groups than in Nannochloropsis‐supplemented groups. High density Chlorella supplementation was associated with the highest incidence of immaturity and resulted in larval mass mortality. The premoult of the third zoeal stage was identified as a critical period at which Chlorella supplementation led to the highest incidence of immaturity. This critical period coincided with the critical period at which larval metamorphosis was regulated by the eyestalk neurosecretory system. Our results suggested that the occurrence of immature megalopal morphology under culture conditions is most likely caused by phytoplankton (especially, Chlorella) supplementation, which disrupts the endocrine regulation. On the basis of our results, we successfully prevented the occurrence of immature megalopal morphology in 500 L tanks by excluding the influence of phytoplankton before the critical period (i.e. discontinuing phytoplankton supplementation and supplying rotifer cultured with non‐phytoplankton materials).  相似文献   
75.
The lower Ili River Basin is located in semi-arid area, and the annual rainfall is 177mm. Therefore, the irrigation is inevitable for agriculture. Large-scale irrigated agriculture had been developed since 1960's in the lower parts of the river and the total irrigated area is about 32 000 hm2. In the project area, the paddy rice-upland crop rotation has been practiced. Due to the domestic water use for hydropower and agriculture as well as water use among riparian countries, the deficit of water for agriculture in the lower part has been concerned. The authors, therefore, conducted the field survey and water balance analysis of the Akdara irrigation project in the lower Ill River Basin in order to assess the land and water uses. Moreover, the impact of the water use on water environment to the basin was analyzed. The following results were obtained as following (1) the groundwater level in the irrigated district varied from 1.5 m to 3.5 m through year. (2) 1970's groundwater level was drastically raised from 8 m to 3 m and the groundwater had been recharged in this period. (3) Water use efficiency of agriculture, which is the ratio of total evapotranspiration to the total water withdrawal was as low as 0.23.  相似文献   
76.
Water stress reduces soybean (Glycine max) yield in fields converted from clayey-soil rice (Oryza sativa) paddies to uplands (upland converted paddies [UCPs]). Subirrigation and/or allowing roots to penetrate to a deeper soil layer were expected to effectively mitigate water stress. Therefore, we examined the effects of subirrigation and slit tillage on mitigating water stress in clayey soils (52% clay) in UCPs. Four treatment experiments (subirrigation, slit tillage, subirrigation control, and slit tillage control) were conducted in each of three growing seasons, with sampling for yield analysis conducted in triplicate. Following conventional tillage, a slit tillage blade was used to cut 15-mm-wide vertical slits in the surface of the soil (cutting depth = 15–20 cm) and seeds were sown 15 mm from the cut lines. Subirrigation then occurred for approximately 21–47 days, from the end of the rainy season, when water table elevation was at 35 cm below ground. We found that subirrigation only resulted in improved soybean yield in 2012, when precipitation after the flowering stage was low, whereas slit tillage significantly increased yield in all three growing seasons, including a particularly wet growing season. Overall, subirrigation and slit tillage increased soybean yield by 2% and 13%, respectively. Slit tillage also resulted in a significantly greater taproot length and root density. Stomatal conductance at midday in about the R5–6 stages was higher in slit-tilled plots than in control plots, but only in the subirrigated field.  相似文献   
77.
We genotyped Setaria italica Dehydration-responsive element-binding 2 (SiDREB2) gene, which had been reported to be associated with dehydration stress tolerance, in 588 accessions of foxtail millet from various parts of Eurasia and other regions by a dCAPS marker. Of these, 480 accessions were genotyped in ribosomal DNA (rDNA), polyphenol oxidase (PPO) gene and Heading date 1 (HD1) gene in our previous studies, and 108 accessions from India were newly used in this study and genotyped in these genes in addition to the SiDREB2 gene. We compared the geographical distribution of the SiDREB2 genotypes with that of these three genes. Accessions from countries in South Asia including India and Sri Lanka were the most variable in the SiDREB2 gene followed by Korean accessions and Japanese accessions, suggesting that Indian accessions and East Asian accessions are useful as genetic resources for dehydration stress tolerance. This study also showed that although Indian accessions are not so diverse in rDNA and in transposon display markers previously studied, they are diverse in adaptive genes such as SiDREB2, PPO and HD1 genes.  相似文献   
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79.
Es wurde der Einftuß vom aus der mit Erde bedeckte Mülldeponie entqundenen Gas auf die mikrobiologischen und chemischen Eigenschaften des Oberbodens untersucht. Auf dem einer Deponie benachbarten Acker wurde das Pflanzenwachstum beeinträchtigt. Sein Bodenprofil war teilweise bläulichschwarz gefärbt. Seine Bodenluft war durch O2-Abnahme und CH4 und CO2-Zunahme gekennzeichnet. Durch den Brutversuch mit sterilisierten und unsterilisierten Bodenproben unter Zusatz von CH4 konnte seine Oxydation durch Mikroorganismen bestätigt werden. Durch das Einfließen des kohlenwasserstoffreichen, sauerstoffarmen Gases und durch den mikrobiellen O2-Verbrauch entstanden anaerobe Verhältnisse. Hierdurch ergaben sich Reduktionen von Fe-, Mn-, N-, und S-Verbindungen, und eine Senkung des Redoxpotentials. Wurde feldfrische Feinerde im Becberglas bebrütet, nahm angereichertes Fe2+ sehr schnell, Mn2+ dagegen langsamer ab. Die Wachstumsstörung sollte auf Sauerstoffmangel, der Gegenwart von Schwefelwasserstoff und Mangan-Überachuß im Boden beruhen.  相似文献   
80.
Post-perovskite phase transition in MgSiO3   总被引:2,自引:0,他引:2  
In situ x-ray diffraction measurements of MgSiO3 were performed at high pressure and temperature similar to the conditions at Earth's core-mantle boundary. Results demonstrate that MgSiO3 perovskite transforms to a new high-pressure form with stacked SiO6-octahedral sheet structure above 125 gigapascals and 2500 kelvin (2700-kilometer depth near the base of the mantle) with an increase in density of 1.0 to 1.2%. The origin of the D" seismic discontinuity may be attributed to this post-perovskite phase transition. The new phase may have large elastic anisotropy and develop preferred orientation with platy crystal shape in the shear flow that can cause strong seismic anisotropy below the D" discontinuity.  相似文献   
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