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81.
Masafumi Amano Katsumi Aida Naoto Okumoto Yoshihisa Hasegawa 《Fish physiology and biochemistry》1993,11(1-6):233-240
Levels of two types of gonadotropin-releasing hormone (salmon GnRH and chicken GnRH-II) in the brain and pituitary, and content of gonadotropin (GTHIβ and IIβ) in the pituitary were measured in male masu salmon from hatching to gonadal maturation for three years in order to clarify the involvement of GnRHs in precocious maturation. Underyearling precocious males were distinguishable in summer of year 1 and were marked by an increased GSI. Spermiation was observed among these individuals thereafter every autumn. Pituitary GTHIβ content in both precocious and immature males, and GTHIIβ content in precocious males showed seasonal fluctuations — high in autumn and low in winter. Pituitary GTHIIβ content was low in immature males. Pituitary sGnRH content in precocious males increased from spring to autumn during the three-year period. sGnRH concentrations in discrete brain areas showed seasonal changes — high during autumn to winter and low in summer. Concentrations in the olfactory bulbs and hypothalamus increased significantly in association with testicular maturation during year 3. sGnRH concentrations in the hypothalamus were significantly higher in precocious males than in immature males; this was possibly due to positive feedback of steroid hormones. cGnRH-II was undetectable in the pituitary and no distinct changes were observed in its concentration in the brain in relation to maturation. The phenomenon of underyearling precocious maturation is considered to be triggered before the onset of early summer. It is suggested that males which mature precociously are larger in size and contain much sGnRH in the pituitary before the outward signs of precocity appear; sGnRH may stimulate GTH II synthesis and induce precocious maturation. 相似文献
82.
Mikimasa Joh Tetsuya Takatsu Mitsuhiro Nakaya Naoto Yoshida Masayasu Nakagami 《Fisheries Science》2009,75(3):619-628
To examine survival processes in marbled sole Pseudopleuronectes yokohamae larvae, nutritional transition date distributions (NTDDs) were compared between larvae and large juveniles (LJs) in Hakodate
Bay from 2001 to 2003. NTDDs were used instead of hatch date distributions because the onset of increment formation coincides
with the timing of the transition from endogenous to exogenous nutritional sources for marbled sole. LJs were defined as being
large enough to be safe from predation by the sand shrimp Crangon uritai. In 2001 and 2002, the ranges of the NTDDs of LJs largely overlapped with those of the larvae. However, in 2003, the early
cohort (those whose otolith rings formed before 17 March) disappeared from the NTDDs during and after April, and the NTDDs
of LJs were heavily biased toward a later period compared to those of the larvae. In 2003, Oyashio coastal water (<3°C and
≤33.0 salinity) unexpectedly intruded into the bay in late March and lowered the water temperature from 6.3°C on 6 March to
4.1°C on 25 March. One possible cause of mortality in the early cohort of 2003 may be feeding failure caused by the extremely
low water temperature. 相似文献
83.
Suzuki T Kim SJ Mohamed ZI Mukasa Y Takigawa S Matsuura-Endo C Yamauchi H Hashimoto N Noda T Saito T 《Journal of agricultural and food chemistry》2007,55(23):9571-9575
The anthocyanin profiles and variety/breeding-line differences of anthocyanin concentrations in petals of common buckwheat flowers have been studied. Four anthocyanins, cyanidin 3-O-glucoside, cyanidin 3-O-rutinoside, cyanidin 3-O-rhamnoside, and cyanidin 3-O-galactosyl-rhamnoside were isolated from the petals of common buckwheat (Fagopyrum esculentum Moench), separated using high performance liquid chromatography and identified using reversed-phase liquid chromatography-electrospray ionization-tandem mass spectrometry techniques. In every variety/breeding line tested, cyanidin 3-O-rutinoside was detected as the major anthocyanin and the next is cyanidin 3-O-glucoside whereas cyanidin 3-O-rhamnoside and cyanidin 3-O-galactosyl-rhamnoside were trace or not detectable in white and pink flowered buckwheat. Of all the varieties/breeding lines tested, Gan-Chao, a Chinese variety, contained the highest amount of anthocyanins. The largest part of cyanidin moiety was presented as a proanthocyanidin form (PAs-Cy). Anthocyanins and PAs-Cy in petals were increased along with increase of flower development stages. Therefore, fully developed petals of red flowered buckwheat, especially Gan-Chao, are promising as a new anthocyanin-rich material for food processing. 相似文献
84.
Yusuke Kudo Kosuke Noborio Naoto Shimoozono Ryuki Kurihara Hayato Minami 《Paddy and Water Environment》2017,15(1):217-220
Many papers on measurements of greenhouse gases (GHGs) emission in rice paddies during a rice cropping season have been published. During a non-cropping season between Nov. and Apr., we investigated direct and indirect GHGs emissions in rice paddies. The indirect GHGs emission was evaluated as the amount of dissolved gases leaching from the paddy fields. Water management practices for the experiment were (1) continuous flooding (CF) and (2) non-flooding (NF). Although the direct CO2 emission in the CF treatment was remained nearly zero during the non-cropping period, direct CO2 emission in the NF treatment was continuously observed throughout the non-cropping period. The concentration of dissolved N2O in the NF treatment was below the detection limit of the instrument during the non-cropping period except immediately after the flooding and before the drainage. The concentration of dissolved N2O kept approximately 2 µg L?1 during the non-cropping period in the CF treatment. The direct CH4 emission and dissolved CH4 were not observed during the non-cropping period. Total gas emission in the NF treatment was 10 times as large as that in the CF treatment. Direct CO2 emission accounted for more than 90 % of the total emission in both treatments. 相似文献
85.
86.
Naoto Yoshida 《Plant pathology》2020,69(7):1379-1389
Carrot motley dwarf (CMD) is caused by mixed infection of carrot red leaf virus (CtRLV) with either carrot mottle virus (CMoV) or carrot mottle mimic virus, and additional infection with CtRLV-associated RNA (CtRLVaRNA). Here, the author investigated the viruses or virus-like RNA isolated from carrots with reddening symptoms in Hokkaido, the northern island of Japan. Three types of infections were mainly detected: single infection with CtRLV, which was most prevalent; double infection with CtRLV and CMoV; and triple infection with CtRLV, CMoV, and CtRLVaRNA. Fields with the three agents were severely affected, with diseased plants showing mottling, whereas in fields where disease incidence was low and sporadic, CtRLV was often found alone in plants with mild symptoms. Inoculation tests using carrot plants showed that CMoV enhanced disease severity, and the RNA accumulation of CtRLV. However, in the presence of CtRLVaRNA (+ CMoV), distinct symptoms such as systemic mottling and stunting developed, while the enhancement of CtRLV accumulation was abolished. These results imply that CtRLVaRNA (+ CMoV) antagonizes CtRLV despite its dependence on CtRLV for aphid transmission, and that mixed infection with CtRLVaRNA is involved in the development of the conspicuous mottling. All agents detected in Hokkaido were very similar to European and American isolates in terms of their genomic sequences and host range. This represents the first report of CMD in Japan, and provides further information on the genetic and biological properties of CMD-associated agents, as well as the aetiology of the disease. 相似文献
87.
88.
89.
Fang Z Nagaosa N Takahashi KS Asamitsu A Mathieu R Ogasawara T Yamada H Kawasaki M Tokura Y Terakura K 《Science (New York, N.Y.)》2003,302(5642):92-95
Efforts to find the magnetic monopole in real space have been made in cosmic rays and in particle accelerators, but there has not yet been any firm evidence for its existence because of its very heavy mass, approximately 10(16) giga-electron volts. We show that the magnetic monopole can appear in the crystal momentum space of solids in the accessible low-energy region (approximately 0.1 to 1 electron volts) in the context of the anomalous Hall effect. We report experimental results together with first-principles calculations on the ferromagnetic crystal SrRuO3 that provide evidence for the magnetic monopole in the crystal momentum space. 相似文献
90.
Shimokawa T Doihara T Makara M Miyawaki K Nabeka H Wakisaka H Kobayashi N Matsuda S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(9):1233-1236
Sugars in the glycocalyx play an important role in the attachment of infectious agents to the respiratory mucosa. We examined the histochemistry of 23 lectins to survey the sugar expression in the glycocalyx of the respiratory mucosa of the Pacific white-sided dolphin, Lagenorhynchus obliquidens. The ciliated and basal cells were positive for all of the lectins studied. SBA, WFA, GSL-II, STL, S-WGA, and PNA staining in the cytoplasm showed different intensities between basal cells and ciliated cells. These results suggest that multiple terminal glycosylation occurs on ciliated and basal cells, such as GalNAc, GlcNAc, NeuNAc, galactose, glucose/mannose, oligosaccharide, and fucose, and that sugar residue expression changes during cell differentiation. The Pacific white-sided dolphin respiratory mucosa might express multiple sugar residues in the glycocalyx, to prevent the attachment and colonisation of infectious agents. 相似文献