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51.
Effects of photoperiod and night‐time aeration rate on swim bladder inflation and survival in Pacific bluefin tuna,Thunnus orientalis (Temminck & Schlegel), larvae 
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下载免费PDF全文 Michio Kurata Yoshiki Tamura Tomoki Honryo Yasunori Ishibashi Yoshifumi Sawada 《Aquaculture Research》2017,48(8):4486-4502
Success of swim bladder inflation (SBI) is crucial for early survival of Pacific bluefin tuna (PBF) larvae, because it reduces larval sinking death by enhancing buoyancy. In Experiment 1, we examined the effect of photoperiod on SBI and survival in PBF larvae by comparing photoperiods of 9L: 15D (9L), 14L: 10D (14L: natural photoperiod), 19L: 5D (19L) and 24L: 0D (24L) during 2–10 days post hatch (dph). In Experiment 2, the combined effects of photoperiod (24L and 14L) and nighttime aeration rate (enhanced night‐time aeration: ENA of 1300 mL min?1 as a countermeasure for sinking death and 130 mL min?1) on the survival and SBI were also examined during 2–10 dph. Moreover, in Experiment 3 the effect of photoperiod on vertical distribution of larvae in night‐time was examined on 3–5 dph. Photoperiod of 24L in Experiment 1 significantly inhibited SBI compared with 14L and 19L; nevertheless, it significantly improved survival compared with other photoperiods with a dark period. On the other hand, the shortened light period (9L) showed significantly reduced SBI and also survival. In Experiment 2, the countermeasure for sinking death of ENA under 24L did not further improve the survival; rather it tended to reduce the survival. In Experiment 3, larvae distributed less in the bottom layer in 24L than in 14L, suggesting the reducing effect of 24L on sinking death. The results indicate that 24L without ENA is suitable for survival which is the most serious problem in PBF larviculture. 相似文献
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Increasing nitrate removal at low temperatures by incorporating organic matter into paddy fields 总被引：1，自引：0，他引：1
Tomoki TAKAHASHI Hidehiro INAGAKI Tsutomu FUKUSHIMA Tomohiro OISHI Kazuo MATSUNO 《Soil Science and Plant Nutrition》2010,56(1):163-167
Denitrification of paddy fields is a key process for improving water quality in fields where nitrate concentrations are high. The objective of the present study was to understand the effects of incorporating organic carbon (C) into soil on the denitrification rate of paddy fields in winter. On 11 December 2007, separate paddy field plots were prepared by incorporating 5 Mg ha−1 of rice straw (RS), 11 Mg ha−1 of rice straw compost (RSC) or a control. A field with a high concentration of nitrate in the water (averaging 18 mg N L−1 ) was irrigated until 29 March. During the experiment, the daily average soil temperature at a depth of 0.05 m ranged between 3 and 15°C. The nitrate concentration in the surface water in the RS plot, where the residence time was 2 days, decreased more than the concentration in the control or RSC plots. The total estimated nitrate removal from each plot in relation to the other plots was RS > RSC = control. Measurements of the soil from each plot on 29 February 2008 showed that incorporation of RS significantly increased the denitrification potential, even at low temperatures (5–10°C). Furthermore, the RS plot contained more dissolved organic C than the control or RSC plots. This result indicates that supplying RS effectively increases denitrification under low-temperature conditions. 相似文献
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Shimizu Daisuke Mizusawa Kanta Maeda Tomoki Yamaguchi Daigo Takahashi Akiyoshi 《Fisheries Science》2021,87(1):113-119
Fisheries Science - We examined the effects of tank color and stocking density on the growth of spotted halibut (Verasper variegatus) under a green light-emitting diode (LED). Fish reared for... 相似文献
54.
Zolensky ME Zega TJ Yano H Wirick S Westphal AJ Weisberg MK Weber I Warren JL Velbel MA Tsuchiyama A Tsou P Toppani A Tomioka N Tomeoka K Teslich N Taheri M Susini J Stroud R Stephan T Stadermann FJ Snead CJ Simon SB Simionovici A See TH Robert F Rietmeijer FJ Rao W Perronnet MC Papanastassiou DA Okudaira K Ohsumi K Ohnishi I Nakamura-Messenger K Nakamura T Mostefaoui S Mikouchi T Meibom A Matrajt G Marcus MA Leroux H Lemelle L Le L Lanzirotti A Langenhorst F Krot AN Keller LP Kearsley AT 《Science (New York, N.Y.)》2006,314(5806):1735-1739
The bulk of the comet 81P/Wild 2 (hereafter Wild 2) samples returned to Earth by the Stardust spacecraft appear to be weakly constructed mixtures of nanometer-scale grains, with occasional much larger (over 1 micrometer) ferromagnesian silicates, Fe-Ni sulfides, Fe-Ni metal, and accessory phases. The very wide range of olivine and low-Ca pyroxene compositions in comet Wild 2 requires a wide range of formation conditions, probably reflecting very different formation locations in the protoplanetary disk. The restricted compositional ranges of Fe-Ni sulfides, the wide range for silicates, and the absence of hydrous phases indicate that comet Wild 2 experienced little or no aqueous alteration. Less abundant Wild 2 materials include a refractory particle, whose presence appears to require radial transport in the early protoplanetary disk. 相似文献
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Tomoki TAKAHASHI Keiko NAKANO Rikiya NIRA Etsushi KUMAGAI Mizuhiko NISHIDA Mari NAMIKAWA 《Soil Science and Plant Nutrition》2020,66(3):407-414
ABSTRACT The conversion between the two different systems, ISSS and FAO/USDA, of particle size distribution and soil texture classification is useful to characterize soil physical properties and usage of each published. The objective of this study is to test some functions that have been published for conversion from ISSS to FAO/USDA system for Japanese paddy soils and to select the best method. We tested the topsoils of 267 Japanese paddy fields using the log-linear method, log-normal method, multiple regression method, Skaggs et al.’s method, and Minasny and McBratney’s method. The least AIC was obtained using multiple regression method, and the equation derived was given as follows: siFAO/USDA = 1.305siISSS + 0.396fsISSS?0.100csISSS ? 12.323 where si, fs, and cs are the percentage of silt, fine sand, and coarse sand respectively; ISSS and FAO/USDA is the fractionation system; and its RMSE was 3.1%. For the case that only the total sand content (s) is available instead of fine sand and coarse sand, the following equation was obtained: siFAO/USDA = 0.314siISSS + 1.533sISSS ? 20.903 (RMSE = 3.7%) Among the non-empirical methods, the best estimation method was Skaggs et al.’s method, and its RMSE was 3.3%. The soil texture classification by FAO/USDA system using estimated particle size fractions by the above equation can be classified to correct categories. The accuracy ratio of the classification was 93-97%. 相似文献
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Seijirow Goya Tomoki Wada Kazumi Shimada Daiki Hirao Ryou Tanaka 《Veterinary anaesthesia and analgesia》2018,45(4):432-442
Objective
To investigate the dose-dependent effects of isoflurane and dobutamine on haemodynamics in dogs with experimentally induced mitral valve insufficiency (MI).Study design
Experimental, dose–response study.Animals
Six healthy Beagle dogs.Methods
Dogs with surgically induced MI were anaesthetized once. First, anaesthesia was maintained at an end-tidal isoflurane concentration (Fe′Iso) 1.0% (ISO1.0) for 20 minutes. Then, dobutamine was infused successively at 2, 4, 8 and 12 μg kg?1 minute?1 (DOB2–12) for 10 minutes at each dose rate. Measurements were recorded at each stage. Dobutamine was discontinued and Fe′Iso was increased to 1.5% (ISO1.5) for 20 minutes. Dobutamine was administered similarly to ISO1.0, and cardiovascular variables were recorded. The same sequence was repeated for Fe′Iso 2.0% (ISO2.0). Aortic pressure (AoP) and left atrial pressure (LAP) were recorded by radiotelemetry. The combination method of the pressure–volume loop analysis and transoesophageal echocardiography was used to measure cardiovascular variables: end-systolic elastance (Ees), effective arterial elastance (Ea), Ea/Ees, forward stroke volume (FSV), heart rate (HR), and cardiac output (CO).Results
High isoflurane concentration resulted in reduced Ees and increased Ea/Ees, which indicated low arterial pressure. High-dose dobutamine administration resulted in increased Ees and FSV at all isoflurane concentrations. In ISO1.5 and ISO2.0, HR was lower at DOB4 than baseline (BL) but increased at DOB12 compared with DOB4. CO increased at ≥ DOB8 compared with BL. In ISO1.5 and ISO2.0, systolic and mean AoP increased at ≥ DOB4 and ≥ DOB8, respectively. LAP did not change under all conditions.Conclusions and clinical relevance
The dose-dependent hypotensive effect of isoflurane in MI dogs was mainly derived from the decrease in contractility. Dobutamine increased AoP without increasing LAP by increasing the contractility attenuated by isoflurane. Our findings may improve the cardiovascular management of dogs with MI undergoing general anaesthesia with isoflurane. 相似文献58.
Kiyonori HAYASHI Mitsuhiro FURUSE Tomoki SOH Haruo KUSABA Hisao IWAMOTO K
ichi AND 《Animal Science Journal》2002,73(6):523-531
Development of cerebrovascular noradrenergic (NA) innervation was investigated in the Japanese quail, using histofluorescence technique and quantitative analysis. Cerebral perivascular NA nerves arose from the cerebral carotid (CCA), internal ethmoidal (IEA) and vertebral (VA) arteries before hatching, with the first appearance on the CCA and IEA at embryonic day (E) 8 and of the VA at E14. Nerves arising from the IEA were greater in number and spread more rapidly than those from the CCA and VA. On E16, fluorescent fiber bundles lying on the anterior circulation subdivided rapidly into thin fibers. Consequently, the number of NA nerves over the arterial system increased greatly at hatching, particularly along the distal portion of the anterior ramus. At the same developmental stage, all the major arteries of the anterior and posterior circulation were almost entirely covered by NA nerves. The abrupt reorganization of cerebrovascular NA innervation in newborn quails may be related to some specific trophic and vasomotor roles for structural and functional improvement of the cerebral circulation that is required for its brain differentiation at this critical period of development. The supply of NA nerves to the anterior and posterior circulations sequentially increased during development from posthatching day (P) 1–15. Plexuses of NA nerves in each of the major cerebral arteries at P22 and P42–50 were similar in meshwork construction to each other, and to those seen at P15. Likewise, there was no clear statistical difference in the nerve density of the corresponding arteries among the three posthatching ages, except for the caudal basilar artery. 相似文献
59.
Kubota K Yamauchi N Matsumoto K Watanabe R Oozono S Aramaki S Wood C Soh T Hattori MA 《The Journal of reproduction and development》2008,54(5):340-345
Hedgehog (Hh) plays a pivotal role in various tissues during embryonic development, tissue homeostasis and tumorigenesis. In mammals, Hh exists in three homologs: Desert hedgehog (Dhh), Indian hedgehog (Ihh) and Sonic hedgehog (Shh). In this study, we cloned full-length cDNAs encoding Dhh and Ihh from the rat uterus. Their amino acid sequences have a high homology with those of the mouse and human. In addition, the changes of Hh gene expression in the rat uterus during early pregnancy were analyzed. The results showed that all three hedgehog mRNAs were detected in the rat uterus at the proestrus stage and during early pregnancy (1.5, 3.5, 5.5 and 7.5 days post coitus: dpc). Ihh mRNA expression varied and peaked at 3.5 dpc in the luminal and glandular epithelium. Expression was decreased on 5.5 dpc with the exception of sustained expression in the glandular epithelium. Despite such Ihh variability, the expressions of Dhh and Shh mRNA remained unchanged. This indicated that Ihh was mainly expressed in the rat uterus during early pregnancy. Moreover, the Hh target gene (glioma-associated oncogene homolog 1; Gli1) was also highly expressed at 3.5 dpc in the epithelium and periepithelial stroma in a manner similar to the temporal pattern of Ihh expression. This suggests that Ihh signaling axis play a role in the rat uterus during early pregnancy. In summary, our results elucidate that Ihh is a predominant Hh protein in the rat uterus during early pregnancy and that other Hhs have the potential to be expressed. This observation will help to elucidate the basic molecular mechanism of rat uterus during early pregnancy. 相似文献
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