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61.
The regeneration of Japanese black pine (Pinus thunbergii) seedlings is inhibited in a black locust (Robinia pseudoacacia)-dominated area. We examined the presence of pathogenic fungi in Japanese black pine seedlings in the area in order to determine the effect of pathogenic fungi on the inhibition of regeneration. When Japanese black pine seedlings were planted in the soil obtained from a black locust-dominated area, all of the seedlings died under low-intensity light conditions, whereas 84% of the seedlings survived in the soil obtained from a Japanese black pine-dominated area under the same light conditions. One fungus was isolated from 48.7% of the dead pine seedlings and was identified as Cylindrocladium pacificum Kang, Crous & Schoch, based on the morphological characteristics, growth, and DNA analysis. This fungus was also isolated from 50% of the dead pine seedlings in 2005 and 66.7% of the seedlings in 2006—both were planted in a black locust-dominated area. The virulence of this fungus increased under high-nitrogen and/or low-intensity light conditions. These results reveal the possibility that the soil eutrophication and shading by the black locust are conducive to a severe damping-off disease and threaten the survival and regeneration of Japanese black pine seedlings.  相似文献   
62.
Paddy and Water Environment - Crops adapt to variable soil moisture by varying the distribution of their roots and patterns of water absorption. Meanwhile, proper numerical model for predicting...  相似文献   
63.
Fish express two different chitinases, acidic fish chitinase-1 (AFCase-1) and acidic fish chitinase-2 (AFCase-2), in the stomach. AFCase-1 and AFCase-2 have different degradation patterns, as fish efficiently degrade chitin ingested as food. For a comparison with the enzymatic properties and the primary structures of chitinase isozymes obtained previously from the stomach of demersal fish, in this study, we purified chitinase isozymes from the stomach of Japanese sardine Sardinops melanostictus, a surface fish that feeds on plankton, characterized the properties of these isozymes, and cloned the cDNAs encoding chitinases. We also predicted 3D structure models using the primary structures of S. melanostictus stomach chitinases. Two chitinase isozymes, SmeChiA (45 kDa) and SmeChiB (56 kDa), were purified from the stomach of S. melanostictus. Moreover, two cDNAs, SmeChi-1 encoding SmeChiA, and SmeChi-2 encoding SmeChiB were cloned. The linker regions of the deduced amino acid sequences of SmeChi-1 and SmeChi-2 (SmeChi-1 and SmeChi-2) are the longest among the fish stomach chitinases. In the cleavage pattern groups toward short substrates and the phylogenetic tree analysis, SmeChi-1 and SmeChi-2 were classified into AFCase-1 and AFCase-2, respectively. SmeChi-1 and SmeChi-2 had catalytic domains that consisted of a TIM-barrel (β/α)8–fold structure and a deep substrate-binding cleft. This is the first study showing the 3D structure models of fish stomach chitinases.  相似文献   
64.
Curcuminoids are substances of great interest because of their important pharmacological activities, particularly anti-inflammatory, anticarcinogenic, and anti-Alzheimer's activities. In this study, we report the first procedure and effect of processing for the high, efficient, and useful purification of curcumin, demethoxycurcumin, and bisdemethoxycurcumin from turmeric powder. Purification involves high-speed countercurrent chromatographic (HSCCC) separation of these curcuminoids using a simple two-phase solvent system composed of n-hexane/chloroform/methanol/water (5/10/7.5/2.5, v/v). The HSCCC-fractionated effluent peaks indicated that the peak resolutions were 1.7 between curcumin and demethoxycurcumin and 2.1 between demethoxycurcumin and bisdemethoxycurcumin for 25 mg of loaded turmeric powder. These purified substances were analyzed by liquid chromatography-tandem mass spectrometry with scan and daughter scan negative modes, and the wide absorbance from 200 to 500 nm was monitored by photodiode array detection. The separation yielded 1.1 mg of curcumin, 0.6 mg of demethoxycurcumin, and 0.9 mg of bisdemethoxycurcumin (>98% purity). Moreover, the antioxidant effect of curcuminoids was measured by a 1,1-diphenyl-2-picrylhydrazil assay. The order of antioxidant activity was purified curcumin > purified demethoxycurcumin > purified bisdemethoxycurcumin > turmeric powder. Curcumin, demethoxycurcumin, and bisdemethoxycurcumin can be used for various evaluations of their pharmacological activities.  相似文献   
65.
To predict soil moisture condition in arbitral agricultural lands by taking spatial distribution of soil type in a watershed into account, we investigated the possible proper methods of determining the soil hydrological parameters using available soil physical properties database of Japanese soils, “SolphyJ”, and the digital soil map. In this study, simulation of soil moisture was conducted at three neighboring locations, including monitoring sites each in Toyama and Fukui cities. The simulated results of soil moisture appeared to be improved when hydraulic parameters were obtained by fitting water retention data of SolphyJ compared to the parameters estimated by neural network with soil texture and dry bulk density data. It is probably because peculiar soil structure in each field could affect the hydraulic properties more than the soil texture. Simulation results also indicated that soil moistures are much different even if they are located in neighbors (<5 km). We concluded that combination of these two databases is useful for estimating soil hydraulic parameters and to predict soil moisture condition in arbitrary agricultural lands.  相似文献   
66.
Abstract

The humus composition was analyzed and the humic acid characterized by UV and visible absorption spectroscopy in order to investigate the rotting and maturing process of city refuse compost according to the method of Kumada et al. During the composting process, the following findings were obtained: (1) the HT value was almost constant, but the HE/HT ratio varied somewhat, (2) HA increased with decrease in FA, and the PQ value so increased clearly, (3) the shoulder-like absorption at a wavelength near 270 nm weakened, and (4) the RF value of humic acid increased, whereas the Δ log K value seldom varied.

The IR spectrum of humic acid gradually changed as follows: (1) the absorption band in the 1700-1600 cm-1 region and in the 1550-1500 cm-1 region increased slightly, (2) the band in the 1100-1000 cm-1 region decreased, and (3) the bands at 835 and 710 cm-1 com pletely disappeared. On the whole, the shape of the IR spectrum of the city refuse compost became featureless. These changes were probably due to the oxidation which occurred in the composting process.  相似文献   
67.
A cDNA clone encoding a prohibitin-like protein (Toprh) was isolated from a piroplasm cDNA library of Theileria orientalis and its nucleotide sequence was determined. An open reading frame, encoding a polypeptide of 278 amino acid residues, was found in Toprh cDNA sequence. An intron of 89 bp was identified when this cDNA clone was compared with the Toprh gene in the genome of T. orientalis. The deduced amino acid sequence of Toprh shares 93.8, 93.1 and 69.1% identities with the prohibitins of T. parva (from chromosome 1), T. annulata (from chromosome 1), and Plasmodium falciparum, (from chromosome 10), respectively. By Western blot analysis, Toprh was found to be expressed in the piroplasm stage of the parasites.  相似文献   
68.
Herpesviral DNA was detected in 24/261 DNA samples that were extracted from whole blood of 13 wild animal species in South Africa. Herpesviral DNA was shown in 22 impalas (Aepyceros melampus) and 2 springboks (Antidorcas marsupialis). All of DNA sequences detected in impalas were identical, whereas two DNA sequences detected in springboks were different each other. These three sequences showed 44 to 72% homology to the corresponding gene of the Gammaherpesvirinae, indicating that these three viruses should be unrecognized novel gammaherpesviruses. The putative novel herpesviruses were tentatively designated as Aepyceros melampus (impala) herpesvirus 1 (ImHV-1), Antidorcas marsupialis (springbok) herpesviruses 1 (SpHV-1) and 2 (SpHV-2). ImHV-1 seems to be a relatively independent virus. SpHV-1 belongs to a group of ruminant lymphotropic herpesviruses and SpHV-2 is closer to a malignant catarrhal fever virus group. Potential threat of these herpesviruses to domestic animals should be considered.  相似文献   
69.
The mRNA expression patterns of EGF, HB-EGF, Amphiregulin, EGF receptor, IGF-1, CSF-1, IL-1 alpha, IL-1 beta, IL-1 receptor type 1, IL-1 receptor antagonist, LIF, COX-1, COX-2, Mucin-1, calcitonin, and rat USAG-1 mouse homologue, all of which are involved in the process of conceptus implantation to the endometrium, were examined during the estrous cycle by means of real-time quantitative PCR. COX-2, HB-EGF, LIF, Mucin-1, CSF-1, IL-1 alpha, IL-1 beta, and IL-1 receptor antagonist were temporally regulated during the estrous cycle and highly expressed during the estrous stage. In the case of COX-1, EGF, IGF-1, and EGF receptor, the highest mRNA expression was during the diestrous stage. In contrast, the rat USAG-1 mouse homologue mRNA expression did not change during the estrous cycle. These results indicate that rat USAG-1 mouse homologue expression at implantation might be specifically regulated by embryonic factors rather than the maternal environment.  相似文献   
70.
The mechanism by which mouse spermatozoa are injured during freezing   总被引:1,自引:0,他引:1  
To improve the cryopreservation protocol for mouse sperm, we attempted to estimate the type and extent of cryoinjury at various steps of the process. First, we demonstrated that mouse sperm are sensitive to chilling at -15 C and that the sensitivity is dependent on the length of exposure. To estimate cryoinjuries, sperm suspensions were ice-seeded at -5 or -15 C, frozen with liquid nitrogen (LN(2)) gas and then frozen in LN(2). In one experiment, sperm seeded at -5 C were cooled slowly to -15 C before deep freezing. At various steps of the cryopreservation process, the sperm were warmed and their viability was assessed based on motility and the integrities of the plasma membrane and acrosome. The motility of frozen-thawed sperm was higher on seeding at -5 C (28%) than at -15 C (9%). The motility did not decrease when the sample was transferred from LN(2) gas to LN(2). To estimate cryoinjury of sperm, we presumed the viability of frozen sperm to be decreased by chilling, hypertonic stress and formation of intracellular ice. When the sperm suspension was cooled and seeded at -5 C, the motility decreased by 25% due to hypertonic stress. When the sperm were cooled in LN(2) gas, the motility decreased by 17% with the formation of intracellular ice. When the sperm were cooled to -15 C, the motility decreased by 51% from chilling. After seeding, the motility decreased by 18% due to formation of intracellular ice and by 7% due to hypertonic stress. Considering the results, it would be preferable to seed samples at a higher temperature to prevent intracellular ice from forming and to cool seeded samples rapidly enough to minimize chilling injury and hypertonic stress, but not too rapidly to allow intracellular ice to form.  相似文献   
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