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991.
We quantitatively evaluated the cumulative ecological risks from multiple pesticides used in paddy fields in Japan. Moreover, we visualized the temporal and regional variability of those risks for 1990–2010. Considering the region-specific parameters of environmental conditions, region-specific predicted environmental concentrations were estimated at 350 river-flow monitoring sites in Japan. Then the multi-substance potentially affected fraction (msPAF) was calculated as a risk index of multiple pesticides by using the computation tool NIAES-CERAP. The median msPAF values for insecticides and herbicides decreased by 92.4% and 53.1%, respectively, from 1990 to 2010. This substantial reduction in ecological risk was attributed to the development of low-risk pesticides by manufacturers, the efforts of farmers in risk reduction, and tighter regulation by the Japanese government. In particular, the substantial reduction of the ecological risk from insecticides was largely due to the decrease in the use of organophosphorus insecticides. 相似文献
992.
Takashi OKU Kotaro SATO Masaki KURAO Shohei MATSUURA Yasufumi SAKAI Takao TSUCHIYA 《Journal of General Plant Pathology》2000,66(4):332-334
The pathogenic race of 59 cultures of Xanthomonas oryzae pv. oryzae, a pathogen of bacterial leaf blight of rice, isolated from six locations in the inland mountainous area of Hiroshima Prefecture
in 1999, were determined by a set of traditional differentials. Four races—I, II, V and VII—were found across the area; however,
we noticed the composition of the races as well as the dominant race in each location different. All races were avirulent
on differential cultivar Te-tep. Races V and VII were new to Hiroshima. The rice cultivars infected with bacterial leaf blight
in Hiroshima are thought to be grouped into the Kinmaze group, which does not have any resistance genes. Apparently, a variety
of races occurred unexpectedly on the cultivars contrary to stabilizing selection theory.
Received 25 February 2000/ Accepted in revised form 13 July 2000 相似文献
993.
An experimental study was conducted to evaluate the effect of length on the parallel-to-grain tensile strength of Japanese larch (Larix kaempferi, Carriere) lumber. Six hundred pieces of mechanically graded lumber were tested at gauge lengths of 60, 100, and 180 cm. The lumber was sorted into matched groups according to the dynamic Young's modulus measured by the longitudinal vibration method before the lumber was cut to the particular length. The averages of the dynamic Young's modulus of high-grade (H) and low-grade (L) specimens were 12.8 and 7.5 GPa, respectively. Using nonparametric estimates, the estimated length effect parameters of H and L were 0.268 and 0.304 for the 50th percentile and 0.121 and 0.256 for the 5th percentile, respectively. We then concluded that the different length effect factors between H and L could be used when using the lumber for practical purposes. The parameters of L were larger than those for H, and the parameters for 5th percentiles were smaller than the parameters for 50th percentiles. When two-parameter Weibull distribution functions were fitted to the strength data, the estimated shape parameters of the Weibull distribution by the parametric method were almost identifical to the inverse of nonparametric parameters except the 5th percentiles for H. The influence of defects such as knots on the lower tail of the strength distribution in H may be different from that in L.Part of this paper was presented at the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998 相似文献
994.
The tensile strength (TS) test results of Japanese larch (Larix kaempferi, Carriere) lumber of varying length have shown that the length effects on TS were different between high-grade (H) and low-grade (L) lumber. In this paper, we examined the effect of knots on the TS distribution by measuring the number of knots and the knot area ratio of each specimen. There were more knots in L than in H; and the knot area ratio in L distinctly increased as the length increased compared to that in H. The correlation coefficients between physical properties and TS indicated that knots were the most influencial factor for TS among several physical properties: annual ring width, distance from pith, density, dynamic Young's modulus, and knots. We attempted to estimate the length effect parameters by introducing the concept of assumed knot strength. We thought that the length effect parameters for 50th percentiles of TS could be estimated well with fitted 3P-Weibull, and that the parameters for 5th-percentiles could be estimated well with 2P-Weibull fitted to lower-tail 10% data by the likelihood method. The differences of length effect on TS between H and L should be governed by the presence of knots. The independent model based on the concept of assumed knot strength may express the TS of structural lumber of various lengths. 相似文献
995.
Hiroaki SHIGEMURA Takashi MAEDA Shiko NAKAYAMA Akira OHISHI Yuki CARLE Eiko OOKUMA Yoshiki ETOH Shinichiro HIRAI Mari MATSUI Hirokazu KIMURA Tsuyoshi SEKIZUKA Makoto KURODA Nobuyuki SERA Yasuo INOSHIMA Koichi MURAKAMI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(9):1345
Dissemination of extended-spectrum cephalosporin (ESC)-resistant Salmonella is a public health concern in the egg production industry. ESC-resistant Salmonella often acquires the bla gene via insertion sequences (ISs). Therefore, this study aimed to assess antimicrobial resistance in Salmonella from Japanese layer breeding chains and egg processing chains, and determine the genetic profiles of IS-like elements in ESC-resistant Salmonella. Antimicrobial susceptibility testing was performed on 224 isolates from 49 facilities involving layer breeder farms, hatcheries, pullet-rearing farms, and layer farms in breeding chains along with egg processing chains. ESC-resistant Salmonella strains were whole-genome sequenced. Among them, 40 (17.9%) were resistant to at least streptomycin, tetracycline, ampicillin, chloramphenicol, cefpodoxime, nalidixic acid, ciprofloxacin, and/or kanamycin despite lacking resistance to azithromycin and meropenem. Moreover, 15 were ESC-resistant Salmonella harboring blaCMY-2 (Salmonella enterica serovar Ohio, n=12; S. Braenderup, n=1; untypeable with O7:b:-, n=1) and blaCTX-M-14 (S. Cerro, n=1). IncA/C2 plasmids containing ISEcp1, IS26, and multiple antimicrobial resistance genes (including blaCMY-2) were identified in S. Ohio isolates from pullet-rearing and layer farms belonging to the same company. Chromosomal integration of partial or whole IncA/C2 plasmids was seen with two S. Ohio isolates via ISEcp1 or IS26, respectively. Antimicrobial resistance genes such as blaCMY-2 might be transmitted among the upper and the lower levels of layer breeding chains via the replicon type IncA/C2 plasmids containing ISEcp1 and IS26. 相似文献
996.
The influence of inorganic matter on the pyrolysis of Japanese cedar (Cryptomeria japonica) wood was studied at a gasification temperature of 800°C with demineralization through acid washing. Some influences on the
formation of char, tar, and low molecular weight products coincided with results reported at temperatures lower than the gasification
temperature. However, the carbonization behavior of the volatile products and the yield of polysaccharide fraction were not
able to be explained as a sum of the pyrolysis of cellulose, hemicellulose, and lignin even after demineralization. These
results suggest some interactions between wood constituent polymers other than the influence of inorganic matter. 相似文献
997.
998.
999.
Na Song Xiumei Zhang Tianxiang Gao Takashi Yanagimoto 《Journal of the World Aquaculture Society》2011,42(4):512-521
To examine the present population genetic diversity and variability of Japanese flounder, a 394‐bp hypervariable fragment of mtDNA control region was sequenced. A total of 215 individuals from two wild and eight cultured populations were analyzed. The 91 variable sites defined 61 haplotypes and 12 of them were shared. Six single base pair insertion/deletions were detected. The haplotype diversity (h), the nucleotide diversity (π), and mean number of pairwise differences (k) in cultured populations (h = 0.443–0.844; π = 0.010–0.030; k = 3.745–11.838) were obviously lower than those in the wild populations (h = 0.987–0.988; π = 0.032; k = 12.443–12.718). Fixation index (Fst) and analysis of molecular variance (AMOVA) revealed that significant genetic differentiation mainly existed among cultured populations. The results of the exact test of population differentiation (nondifferentiation exact P values) rejected a panmictic mtDNA gene pool in all cultured populations. The results of this study indicated that genetic diversity of cultured Japanese flounder populations in China had significantly declined due to farm propagation and an increase in broodstock number should increase genetic diversity in cultured Japanese flounder base on the genetic theory. 相似文献
1000.
Aigo Takeshige Yoichi Miyake Hideaki Nakata Takashi Kitagawa Shingo Kimura 《Fisheries Science》2013,79(6):989-998
Effect of wind stress on the annual catch of Japanese anchovy Engraulis japonicus off northwestern Kyushu for the period between 1963 and 2009 was investigated. Regime shift analysis detected several step changes in catch and environmental variables. Since the mid-1980s, the anchovy catch in the coastal fishery zones has declined, while the catch in the offshore zone has increased. The decline of catch in the coastal zones showed a significant correlation with the long-term variations in prevailing north-northeastward wind stress over the Goto-Nada Sea during spring spawning season. The results indicated that weakened north-northeastward winds caused the recent low recruitment of anchovy through low levels of wind-induced eggs and larval transport from the offshore spawning ground to the coastal nursery areas, resulting in the potential shift of nursery area to the northwestern offshore region. Thus, as well as the growth-favorable ambient temperature, transport process would play a key role on long-term fluctuations in anchovy abundance in these coastal seas. 相似文献