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991.
Optimal carbamate treatment conditions were studied for flower induction in seedlings of an asparagus cultivar ‘Mary Washington
500 W’. Flower induction was most accelerated by soaking seeds in 50 mg l−1 carbamate solution for 12 days at 25 °C under the fluorescent light. Longer exposure to carbamate over a 12 day period induced a higher percentage of seedlings
to flower. A higher percentage of flowering seedlings were male. Flower induction frequency among seven cultivars through
carbamate treatment widely ranged from 13 to 67%. ‘Geynlim’, ‘Mary Washington 500 W’ and ‘Welcome’ exhibited a high percentage
of flowering seedlings, while ‘Larac’ and ‘Vulkan’ showed low values. Only male flowers were induced in all-male cultivars.
Variation in pollen germination was found within all cultivars. ‘Geynlim’, ‘Cito’ and ‘Mary Washington 500 W’ showed high
values of average pollen germination. Application of carbamate compound to induce flower production can rapidly produce homogenic
cultivars which include both sexes. This is necessary for genetic studies and breeding purposes.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
992.
Masahiro Iwaoka Kazuhiro Aruga Rin Sakurai Koo Hyun Cho Hideo Sakai Hiroshi Kobayashi 《Journal of Forest Research》1999,4(3):195-200
Medium to large size harvester heads mounted on large machines are popular in Japan. These machines encounter some problems
during thinning operations,e.g. damage to residual stand and the compaction of soil. The performance of these large harvesters was compared with that of
smaller ones operating simultaneously in the same line thinning operation of the same stand. The results of a time study showed
that mean cycle times for the smaller and larger harvesters were not significantly different. This means that the work efficiency
of the smaller harvester can be at the same level as the larger harvester on sites similar to those of this study. The mean
values “Feed” element of the cycle time, however, were significantly different. Although this time difference appears to provide
an advantage to the larger harvester, simulation results show that the advantage is not great enough to significantly shorten
the total cycle times. That is to say, the work efficiency remains essentially the same even if the feeding performance of
the small size harvester becomes as high as that of larger ones. The small harvester performs adequately in thinning operations,
and is not inferior to the larger ones. This result indicates that there is economic potential for small base machines that
can be mounted with small harvester heads, resulting in less damage to residual trees and site soils during thinning operation.
A part of this paper was orally presented at the 109th Annual Meeting of the Japanese Forestry Society (1998).
The time study research presented in this paper was supported by the National Federation of Logging Contractors Cooperative
Associations. 相似文献
993.
994.
Rommaneeya LEELA-ARPORN Hiroshi OHTA Genya SHIMBO Noboru SASAKI Mitsuyoshi TAKIGUCHI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(9):1459
The size of canine focal liver lesions (FLLs) is known to be one of the predicting criteria for malignancy. However, there are discrepancies for the measurement of maximum lesion size, resulting in contradicting results among studies and incidences of false positive outcomes. Thus far, the morphometric changes of FLLs for distinguishing malignancy from benignancy remains undocumented. This study aimed to investigate morphometric characteristics of FLLs using computed tomography (CT). CT images of 40 dogs with histopathological confirmation of 49 liver lesions, including 39 hepatocellular carcinomas and 10 nodular hyperplasias were retrospectively reviewed. The morphometric parameters including size (long and short axis diameters measured on transverse image), shape (measured by long to short axis (L/S) ratio), volume, and surface appearance of a liver lesion were evaluated using univariate and stepwise multivariate analyses, respectively. The results of univariate analysis showed that long and short axis diameters, L/S ratio, volume, and surface appearance of a lesion were significantly different between hepatocellular carcinomas and nodular hyperplasias. Multivariate analysis revealed that short axis diameter (>3.30 cm; odds ratio (OR): 36.1, 95% confidence interval (CI): 3.36–387.05, P=0.0031) and L/S ratio (>1.23; OR: 18.1, 95% CI: 1.61–205.12, P=0.0191) were independent predictors of malignancy, with the area under the curve of 0.9154. These results suggest that the combination of short axis diameter and L/S ratio is a promising tool for predicting liver malignancy with outstanding discriminating ability. 相似文献
995.
M Abduh Ibnu Hajar Hiroshi Inada Masahide Hasobe Takafumi Arimoto 《Fisheries Science》2008,74(3):461-468
ABSTRACT: To understand the mechanism of the behavioral response in the capture process of how fish recognize fishing gear and then how they can avoid the gear, the visual acuity of Pacific saury Cololabis saira was investigated by histological examination of the retina of individuals in the size range of 75–365 mm fork length (FL). The contour map of cone density distribution shows that the highest cone density is located in the temporal area of the retina, which indicated the visual axis as the forward direction. The visual acuity (VA) depends both on the focal length of the lens and the number of cones in the retina. The lens diameter increased linearly from 1.40 to 4.73 mm with fish growth, while the cone density decreased gradually from 765 to 378 cells/0.01 mm2 . Our results show that the visual acuity increases proportionately from 0.057 to 0.140 for individuals ranging in FL from 75 to 365 mm as expressed by the equation VA = 0.0065 × FL 0.5271 ( r 2 = 0.9624). 相似文献
996.
Hiroaki Kurogi Makoto Okazaki Noritaka Mochioka Tadao Jinbo Hiroshi Hashimoto Masanori Takahashi Atsushi Tawa Jun Aoyama Akira Shinoda Katsumi Tsukamoto Hideki Tanaka Koichiro Gen Yukinori Kazeto Seinen Chow 《Fisheries Science》2011,77(2):199-205
Two adult male freshwater eels, Anguilla japonica, were captured in June 2008 in the West Mariana Ridge (13°N, 142°E) in the North Pacific, but collections of females have yet to be reported. In September 2008, we successfully caught two adult female A. japonica, 55.5 and 66.2 cm in total length, in the adjacent but northern area (14°N, 143°E). Six newly hatched eel larvae (pre-leptocephali) were also collected by subsequent plankton sampling conducted near the female catch area. Female adults appeared to be in the post-spawning state, probably a considerable time after spawning, since a small number of remarkably regressed oocytes (50–250 μm in diameter) were observed in the ovaries. Capture of post-spawning female eels and newly hatched larvae near the Suruga Seamount (14°N) together with the previous collection of mature males in the southern area (13°N) corroborates that the area along the West Mariana Ridge is the spawning area of this species, but suggests that the eel spawning may occur over a wider area than previously expected. 相似文献
997.
Hikaru Watanabe Makoto Okazaki Tsutomu Tamura Kenji Konishi Denzo Inagake Takeharu Bando Hiroshi Kiwada Tomio Miyashita 《Fisheries Science》2012,78(3):557-567
This study represents the first quantitative analysis of the characteristics of the distribution areas and stomach contents
of common minke whale Balaenoptera acutorostrata, sei whale B. borealis, and Bryde’s whale B. edeni in relation to oceanographic and prey environments in mid summer in the western North Pacific. Common minke whales were distributed
within subarctic regions and the northernmost region of the transitional domain, coinciding with the main habitat of their
preferred prey, Pacific saury Cololabis saira. Sei whales were mainly found in the northernmost part of the transition zone and showed prey preference for Japanese anchovy
Engraulis japonica, which was significantly more abundant in the main distribution area of the whale than in its adjacent areas. “Hot spots”
of Bryde’s whales were found in several regions of the transition zone between the subarctic boundary and the Kuroshio front.
This whale species preferred Japanese anchovy as prey, for which the distribution density was significantly higher in the
main distribution area of the whale than in the adjacent areas. These results indicate that the summer distributions of Pacific
saury and Japanese anchovy greatly influence the distributions of these whale species, suggesting that the whales’ habitat
selection is closely related to their prey selection. 相似文献
998.
Climate change and interspecific interactions drive species alternations between anchovy and sardine in the western North Pacific: Detection of causality by convergent cross mapping 下载免费PDF全文
Shin‐Ichiro Nakayama Akinori Takasuka Momoko Ichinokawa Hiroshi Okamura 《Fisheries Oceanography》2018,27(4):312-322
The abundance and recruitment of anchovy Engraulis spp. and sardine Sardinops spp. alternate in a synchronized way across the Pacific. Convergent cross mapping (CCM) indicated that climate change drives the alternation of the two species in the California Current System. However, climate indices patterns in the western North Pacific contrast with those in the eastern North Pacific, despite synchronous species alternations occurring. Therefore, it is of great interest to clarify whether climate change, or any other factors, affects the population dynamics of Japanese anchovy and Japanese sardine in the western North Pacific. Using CCM, we tested whether climate change and interspecific interactions affect the population dynamics of these two species. We found that climate change affected recruitment, and we clarified the spatiotemporal pattern of this effect. This result supports the existing hypotheses that population dynamics are regulated by climate change in the western North Pacific. The present study also detected interspecific interactions between sardine and anchovy, which might promote the alternation of the two species, and has not been reported in other regions. 相似文献
999.
Susumu Uji Tadahide Kurokawa Hiroshi Hashimoto Tohru Suzuki Koichi Okuzawa 《Aquaculture Research》2014,45(6):1096-1108
Muscles play important roles in feeding, respiration and swimming during not only adult stage but also larval stage in fish. However, there is no information of the muscle development in larval greater amberjack, Seriola dumerili (Risso). Here, we investigated muscle development in the greater amberjack, focusing primarily on the cranial muscles from 0 days post hatch (dph) to 12 dph using a modified whole‐mount immunohistochemical staining method. We found that the muscles required for feeding develop by 3 dph, when the larvae begin to feed. Subsequently, muscle composition in the dorsal branchial arches changes to the adult form between 5 and 8 dph. At 8 dph, all the muscles required for feeding and respiration appear, whereas the dorsal, pelvic and caudal fin muscles required for swimming develop later. This report provides fundamental information on larval greater amberjack muscle development, which will enable the detection of abnormal larval muscles and improve larval rearing techniques by modifying environmental conditions. 相似文献
1000.
Hiroshi Ashida Toshiyuki Tanabe Keisuke Satoh Atsushi Fukui Sho Tanaka Nobuhiro Suzuki 《Fisheries Science》2010,76(5):785-793
The reproductive biology of male skipjack tuna Katsuwonus pelamis was examined from May 2005 to December 2007 in the tropical western and central Pacific Ocean. Testis maturity was classified
into five stages (i.e., immature, early maturation, mid maturation, late maturation, and regression) on the basis of morphological
changes in the germinal epithelium. The testis duct system (TS), which was characterized by lobules that lack spermatocysts,
store only sperm, and form an anastomosing network, was located under the main sperm duct. The TS was observed at all stages
of maturity except the immature stage, and first appeared in individuals with a fork length (FL) of 38–40 cm. The estimated
minimum size at first maturity was 35.5 cm FL and the size at 0.5 maturity was 40.7 cm in FL. It was difficult to clearly
differentiate the testis maturity stage based solely on the gonad index (GI) class because each GI class contained mature
fish. Monthly changes in testis height index and GI did not follow a seasonal cycle. Mature individuals dominated throughout
the year. These results imply that male skipjack tuna in this area showed evidence of spawning activity throughout the year
without a clear seasonal pattern. 相似文献