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131.
Atsushi Sakai Takahisa Hirayama Shigenori Oshioka Yasumasa Hirata 《Journal of Forest Research》2006,11(4):253-265
Large areas of previously clear-cut conifer plantations have been recently abandoned in Japan. We investigated the vegetation
in the clear-cut sites and examined the environmental factors affecting species composition of the vegetation. We set up 32
study sites, each composed of several study plots (5 × 5 m), ranging from 220 m to 1060 m a.s.l. Elevation and warmth index
(cumulated thermal quantity) were the primary factors affecting the species composition, with clear-cut areas showing a smaller
effect in the nonmetric multidimensional scaling (NMS) ordination. Two-way indicator species analysis (TWINSPAN) divided the
32 study sites into ten vegetation groups, clustering the sites by elevation or by postharvest disturbances (i.e., replanting
or browsing of Sika deer). Deciduous trees and shrubs were significant in the vegetation cover at higher elevations, while
they were less so in areas of high Sika deer populations. We also investigated the abundance of old-growth species, which
are expected to regenerate where the clear-cut site is abandoned. Evergreen Quercus and Castanopsis saplings were abundant at low elevations (<600 m), suggesting that they will successfully regenerate. The sapling densities
of Abies firma and Betula grossa were significantly large where a clear-cut site was adjacent to natural forest, which is expected to act as a seed source.
This implies that degraded deciduous forests may establish after clear-cutting at intermediate and high elevations (>600 m)
if the clear-cut site is distinct from seed sources. It is argued that the preservation of natural forests is critical for
the regeneration of old-growth species. 相似文献
132.
Summary Genetic changes induced by grafting were observed in soybean storage proteins, involving the 11S acidic subunit composition and Kunitz trypsin inhibitor. Changes from Gly
1
Gly
1to Gly
1
gly
1involved the 11S acidic subunit, and those from Ti
0Ti0 to Ti
3Ti0 involved the KTI in the first progeny (G1S1) in the scion (Gly
1
Gly
1
Ti
0Ti0, var. Kinzu) grafted onto var. Raiden (gly
1
gly
1
Ti
3
Ti
3). The progenies G1S2 and G2S1 from the seeds that had been changed segregated for both proteins. However, the segregation ratio in the progenies were different from those of the F2's from the sexual crosses between Kinzu and Raiden used for grafting. These findings show that the changes (changed genes) were transmitted to the progenies in an unstable manner. 相似文献
133.
Summary Characteristics of fruit shape in the progeny from a graft-induced change were analysed. Non-pointed, typically inverted-blunt (two-lobed) fruit apex was observed in chimeric state within a scion of Yatsubusa grafted onto Spanish Paprika (inverted-blunt, three-or four-lobed fruit). This frequency of change in fruit shape was unstable in an early generation on the graft. 相似文献
134.
Noboru Yagishita Yutaka Hirata Hajime Mizukami Hiromu Ohashi Keiko Yamashita 《Euphytica》1990,46(3):249-252
Summary The genetic nature of low capsaicin content in variant strains induced by grafting was elucidated by crossing the G5S23 strain with the two cultivars, Yatsubusa (Capsicum annuum L. var. fasciculatum Ilish) and Spanish Paprika (C. annuum L. grossum Sendt) originally used for grafting. Decreased capsaicin synthesis was a stable characteristic for at least several generations from G5S16 to G5S23 and was transmitted to the progenies of crosses. This fact shows that the decreased capsaicin synthesis is a genetic trait in the graft-induced variant strains. The genetically dependent characteristic of pungency of the G5S23, Yatsubusa and Spanish Paprika were analysed by High Perfomance Liquid Chromatography measurement and tasting assay.Cross experiment between the G5S23 strain, hot parent Yatsubusa and sweet parent Spanish Paprika showed that pungent and sweet for pungency chracteristics are generally controlled by at least two pairs of genes. Although segregation of capsaicin content and pungency was clearly demonstrated in F2 progenies from reciprocal crosses between the G5S23 strain and Spanish Paprika, F2 progenies from reciprocal crosses between G5S23 and Yatsubusa were all hot and did not develop low capsaicin plants. 相似文献
135.
Tani H Noda N Yamada K Kurata S Tsuneda S Hirata A Kanagawa T 《Journal of agricultural and food chemistry》2005,53(7):2535-2540
Quenching probe (QProbe) polymerase chain reaction (PCR) is a simple and cost-effective real-time PCR assay in comparison with other real-time PCR assays such as the TaqMan assay. We used QProbe-PCR to quantify genetically modified (GM) soybean (Roundup Ready soybean). We designed event-specific QProbes for Le1 (soy endogenous gene) and RRS (recombinant gene), and we quantified certified reference materials containing 0.1, 0.5, 1, 2, and 5% GM soybean. The TaqMan assay was also applied to the same samples, and the results were compared. The accuracy of QProbe-PCR was similar to that of TaqMan assay. When GM soybean content was 0.5% or more, the relative standard deviations of QProbe-PCR were less than 20%. QProbe-PCR is sensitive enough to monitor labeling systems and has acceptable levels of accuracy and precision. 相似文献
136.
Volcanism in response to plate flexure 总被引:2,自引:0,他引:2
Hirano N Takahashi E Yamamoto J Abe N Ingle SP Kaneoka I Hirata T Kimura J Ishii T Ogawa Y Machida S Suyehiro K 《Science (New York, N.Y.)》2006,313(5792):1426-1428
Volcanism on Earth is known to occur in three tectonic settings: divergent plate boundaries (such as mid-ocean ridges), convergent plate boundaries (such as island arcs), and hot spots. We report volcanism on the 135 million-year-old Pacific Plate not belonging to any of these categories. Small alkalic volcanoes form from small percent melts and originate in the asthenosphere, as implied by their trace element geochemistry and noble gas isotopic compositions. We propose that these small volcanoes erupt along lithospheric fractures in response to plate flexure during subduction. Minor extents of asthenospheric melting and the volcanoes' tectonic alignment and age progression in the direction opposite to that of plate motion provide evidence for the presence of a small percent melt in the asthenosphere. 相似文献
137.
Masuno K Yanai T Hirata A Yonemaru K Sakai H Satoh M Masegi T Nakai Y 《Veterinary pathology》2006,43(2):202-207
Light and electron microscopic features and immunohistochemical features of Cryptosporidium andersoni (C. andersoni) and host reaction in the mucosa were studied. Although the affected cattle demonstrated no apparent clinical signs, a severe infection of C. andersoni was observed in the abomasum. C. andersoni were round in shape, measured 6-8 microm in size and were mainly observed to be freely located in the gastric pits, being attached in occasional cases to the surface of the abomasum epithelium. Frequent inflammatory cells had infiltrated the lamina propria of the affected mucosa, and frequent mitotic figures were observed in epithelial cells at the dilated isthmus. To access the cell kinetics, the number of epithelial cells infected with C. andersoni were counted and compared with noninfected cattle. The number of gastric pit cells in infected cattle was significantly higher than that in the controls. The number of proliferative cells determined by the Ki-67 antigen in C. andersoni infected cattle was also significantly higher than that in the controls. Transmission electron microscopy and scanning electron microscopy revealed that the morphology of the C. andersoni organism was common to those of other Cryptosporidium spp. Immunohistochemically, several commercial antibodies against Cryptosporidium spp. showed positive reactions at the wall of these oocysts or parasitophorous vacuoles. This report is possibly the first to discuss the prominent hyperplasia of the abomasum mucosa, as well as morphologic features of C. andersoni in cattle. 相似文献
138.
Shingo Matsumoto Noriharu Ae Yohichi Koyama Katsumasa Iijima Rumiko Kodashima Mari Hirata Junko Kasuga Nobuhisa Koga 《Biology and Fertility of Soils》2008,45(1):107-111
Phosphate buffer-extractable organic nitrogen (PEON), which can be extracted from soil with a 67-mM neutral phosphate buffer
solution, is considered to be a major source of mineralizable nitrogen (N) that is ubiquitous in soil. We have developed a
Western blot analysis and enzyme-linked immune sorbent assay (ELISA) method for determining PEON. First, anti-PEON antibody
(IgG) from a rabbit was produced using purified PEON from a volcanic ash soil. PEON was detected as a ladder-like staining
pattern in the high-molecular-weight region and as a single band under 14 kDa in Western blot analysis using the anti-PEON
IgG. In the ELISA assay, the anti-PEON IgG could specifically react with PEON irrespective of soil type and management. Furthermore,
the absorbance at 450 nm in ELISA was highly correlated to the concentration of organic N (Norg) in phosphate extracts of different soils. We propose the immune assay using the anti-PEON IgG as a possible novel method
for evaluating available N in soil. 相似文献
139.
Yasuhiro Sugimoto Yukio Toyomitsu Isao Muto Masahiko Hirata 《Water, air, and soil pollution》2009,199(1-4):23-32
This study monitored nitrate levels in well water and analyzed their association with well attributes (physicochemical parameters of water, location, livestock farming conditions) in a nitrate-polluted, animal industry district in central Miyakonojo Basin, southern Kyushu, Japan, to characterize the nitrate status of groundwater in the district. Water quality varied considerably among the wells, with nitrate-N concentration and natural nitrogen-15 abundance in nitrate-N (δ15N-NO3) ranging from 1.1–44.6 mg L?1 and 4.2–17.8‰, respectively. There was a significant positive correlation between nitrate-N concentration and δ15N-NO3. Nitrate-N concentration was higher in wells located at higher elevations, having larger areas of livestock barns within a 100-m radius and with higher animal populations. Wells in pig farms showed a higher nitrate tendency than those in the other situations (cattle farm, poultry farm, non-livestock farm and non-farmer). The results show that the nitrate status of groundwater in the district has not been drastically changed since 1996, and the nitrate in the wells is of multiple origins (e.g. chemical fertilizer, animal wastes) with a tendency for higher contribution of animal wastes in more heavily polluted wells. The results also highlight a need for further regular monitoring of groundwater quality in the district particularly for wells; (1) located at higher elevations, (2) with a large area of livestock barns nearby, (3) in farms with a high animal population and/or (4) in pig farms. 相似文献
140.
Kato A Obara K Igarashi T Tsuruoka H Nakagawa S Hirata N 《Science (New York, N.Y.)》2012,335(6069):705-708
Many large earthquakes are preceded by one or more foreshocks, but it is unclear how these foreshocks relate to the nucleation process of the mainshock. On the basis of an earthquake catalog created using a waveform correlation technique, we identified two distinct sequences of foreshocks migrating at rates of 2 to 10 kilometers per day along the trench axis toward the epicenter of the 2011 moment magnitude (M(w)) 9.0 Tohoku-Oki earthquake in Japan. The time history of quasi-static slip along the plate interface, based on small repeating earthquakes that were part of the migrating seismicity, suggests that two sequences involved slow-slip transients propagating toward the initial rupture point. The second sequence, which involved large slip rates, may have caused substantial stress loading, prompting the unstable dynamic rupture of the mainshock. 相似文献