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61.
To examine water circulation patterns of coastal water, 72 seaweed (Sargasso) samples and 27 coastal water samples were collected from coastal areas of the Noto Peninsula, Japan, during the period from December 1998 to June 2002. The (228)Ra and (226)Ra activities of those samples were measured by low-background gamma-ray spectrometry. There was a wide range of activities of (228)Ra (0.5-2Bq/kg-fresh) and (226)Ra (0.5-1.2Bq/kg-fresh) in the Sargasso samples. The (228)Ra/(226)Ra activity ratio of Sargasso samples exhibited seasonal variation with minimum values in June ((228)Ra/(226)Ra= approximately 1) and maximum values in December (1.5-2.5), which was mainly governed by changes in (228)Ra activity. It is also notable that the seasonal variation of the (228)Ra/(226)Ra ratio of Sargasso is in approximate agreement with that of the ambient coastal water. Sargasso samples appear to have retained the (228)Ra/(226)Ra ratio of the ambient coastal waters, and the temporal variations in that ratio provide insight into seasonal changes in water circulation in the Noto Peninsula coastal area. 相似文献
62.
Ken Inoue Makoto Kanai Yuzo Tanabe Takeo Kubota Catherine D. Kashork Keiko Wakui Yoshimitsu Fukushima James R. Lupski Lisa G. Shaffer 《黑龙江环境通报》2001,21(13):1133-1136
A submicroscopic genomic duplication in Xq22.2 that contains the entire proteolipid protein 1 gene (PLP1) is responsible for the majority of Pelizaeus–Merzbacher disease (PMD) patients. We previously developed an interphase FISH assay to screen for PLP1 duplications in PMD patients using peripheral blood and lymphoblastoid cell lines. This assay has been utilized as a clinical diagnostic test in our cytogenetics laboratory. To expand usage of the interphase FISH assay to prenatal diagnosis of PLP1 duplications, we examined three PMD families with PLP1 duplications utilizing aminiotic fluid samples. In two families the FISH assay revealed fetuses with PLP1 duplications, whereas the other fetus showed a normal copy number of PLP1. Haplotype analyses, as well as an additional FISH analysis using postnatal blood samples, confirmed the results of the prenatal analyses. Our study demonstrates utility of the interphase FISH assay in the prenatal diagnosis of PLP1 duplications in PMD. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
63.
Hidetoshi Kita Koji Nanbu Takeo Hamano Makoto Yoshino Ken-ichi Okamoto Masamitsu Funaoka 《Journal of Polymers and the Environment》2002,10(3):69-75
Carbon molecular sieving membranes were prepared by pyrolysis of lignocresol derived from lignin by the phase-separation method. Lignocresol membranes formed by a dip process on a porous -alumina tubing were carbonized at 400–800°C under nitrogen atmosphere. The thickness of the membrane formed on the outer surface of the substrate was about 400 nm judging from SEM observation. Gas-evolving behavior of lignocresol was measured using thermogravimetry-mass spectrometry (TG-MS). The gaseous products evolved from lignocresol included a number of fragments with higher molecular weights; whereas those from phenolic resin are mainly due to phenol and methylphenol. These evolved pyrolysis fragments effectively contribute to micropore formation of carbonized lignocresol membranes. Gas permeation rates through the membrane decreased in the order of increasing kinetic molecular diameter of the penetrant gas, and the membrane behaved like a molecular sieve. The permeation properties were dependent on heating conditions, and a pyrolysis temperature of 600°C gave the best membrane performance. Gas selectivities of the membrane prepared at 600°C were 50, 8, 290, and 87 for CO2/N2, O2/N2, H2/CH4, and CO2/CH4 at 35°C, respectively. 相似文献
64.
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a widely spread environmental pollutant. Homopoietic system is one of the targets of TCDD in laboratory animals including monkeys. The present study is the hemopoietic cell kinetics in mice, from the severe depression in cellularity of bone marrow and CFU-GM, to their recovery after the intraperitoneal injection of high dosage of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD). The bone-marrow cellularity and CFU-GM were severely decreased to 37.8% and 48% of the control, respectively until day 1 after exposure to TCDD. They were, however, soon recovered, even overshot the control value. Subsequently, they tended to show decrease and oscillation again to and under the control value. In conclusion, our cell kinetic study has proven the oscillation in bone-marrow cellularity and CFU-GM during the recovery period, of which the observation seems to be useful to extend our understanding in the hematotoxicity of TCDD. 相似文献
65.
66.
The optical beam deflection method was applied to study the effects of acid solution on both a terrestial and aquatic plants Egeria and Cerastium, which are common aquatic plant and terrestial weed respectively. A probe beam from a He-Ne laser was passed through a vicinity of a leaf of the plants, which were put in culture dishes filled with acid solutions. Deflection signals of the probe beam were monitored and compared for acid solutions with different pH values. The results of Egria showed that the deflection signals changed dramatically when pH values of acid solutions were 2.0 and 3.0, while little at pH of 4.0 and 5.0. For Cerastium when pH were below 3.0, deflection signals changed greatly with time at the begining. After a certain period of time, deflection signals changed little with time. When pH value was above 4.0, deflection signals of Cerastium were still changing with time even after 20 hours. The results suggested that the damage threshold of pH was between 3.0 and 4.0 for both the land and aquatic plants. 相似文献
67.
To examine water circulation patterns of coastal water, 72 seaweed (Sargasso) samples and 27 coastal water samples were collected from coastal areas of the Noto Peninsula, Japan, during the period from December 1998 to June 2002. The (228)Ra and (226)Ra activities of those samples were measured by low-background gamma-ray spectrometry. There was a wide range of activities of (228)Ra (0.5-2Bq/kg-fresh) and (226)Ra (0.5-1.2Bq/kg-fresh) in the Sargasso samples. The (228)Ra/(226)Ra activity ratio of Sargasso samples exhibited seasonal variation with minimum values in June ((228)Ra/(226)Ra= approximately 1) and maximum values in December (1.5-2.5), which was mainly governed by changes in (228)Ra activity. It is also notable that the seasonal variation of the (228)Ra/(226)Ra ratio of Sargasso is in approximate agreement with that of the ambient coastal water. Sargasso samples appear to have retained the (228)Ra/(226)Ra ratio of the ambient coastal waters, and the temporal variations in that ratio provide insight into seasonal changes in water circulation in the Noto Peninsula coastal area. 相似文献
68.
Soromon Kataoka Hideaki Sawai Hideto Yamada Nozomi Kanazawa Koji Koyama Gen Nishimura Mamoru Morikawa Noriaki Sakuragi Hisanori Minakami 《黑龙江环境通报》2004,24(1):45-49
Hypochondroplasia is an autosomal dominant skeletal dysplasia expressing postnatal onset of short stature with mild rhizomelic shortening of the limbs. This manifestation leads to restricted prenatal diagnosis of the disorder. We report here on a sporadic case of a hypochondroplastic baby, whose prenatal sonographic measurements were serially recorded from 19 weeks of gestation. Mild shortening of the limbs became manifest after 26 weeks of gestation. Biparietal diameter was within the normal range throughout gestation. Both parents were of average stature. A tentative diagnosis of a nonlethal short-limb skeletal dysplasia was made. At birth, the clinical manifestations of the neonate were not characteristic, but the radiographic features raised the possibility of hypochondroplasia. Molecular analyses revealed a C to G mutation at nucleotide 1659 of the fibroblast growth factor receptor 3 (FGFR3) gene, a common mutation in hypochondroplasia. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
69.
Sex mosaics in a male dimorphic ant Cardiocondyla kagutsuchi 总被引:1,自引:1,他引:0
Gynandromorphy, or the development of organisms with a combination of male and female morphological features, is common in
Hymenoptera. The underlying mechanism is likely associated with the sex-determination system, and studying this phenomenon
should lead to a deeper understanding of both embryonic development and sex determination. The reproductive capabilities of
gynandromorphs (hereafter, sex mosaics) remain unclear. We studied gynandromorphy in the Malaysian ant Cardiocondyla kagutsuchi, which has sex mosaics of queens (gynandromorphs; mosaic of queens and winged male) and workers (ergatandromorphs; mosaic
of worker and wingless ergatoid male). These sex mosaics were classified into seven morphological categories. Most individuals
had more male than female body areas. Behavioral observations revealed that sex mosaics behave more in accordance with the
“sex” of their brain than that of the reproductive organs (gaster). Relative DNA quantities showed that both female and male
regions contained haploid and diploid nuclei, irrespective of their phenotypic appearance, indicating that external appearance
did not reflect internal tissues. Nearly one third of the adults were sex mosaics and they were not infected with Wolbachia. Our results suggest that the production of sex mosaics in this species does not pose a substantial cost to colonies and
that the underlying causes are therefore not strongly selected against. 相似文献
70.
Tomoyoshi?HirotaEmail author Kazuei?Usuki Masaki?Hayashi Manabu?Nemoto Yukiyoshi?Iwata Yosuke?Yanai Tomotsugu?Yazaki Satoshi?Inoue 《Mitigation and Adaptation Strategies for Global Change》2011,16(7):791-802
In the northernmost region of Japan (Hokkaido Island), earlier onsets of thick snowcover in recent years (post 1980) have
reduced the penetration depth of soil frost, resulting in over-winter survival of unharvested small potato (Solanum tuberosum) tubers that emerge as weeds in the spring in rotation crop fields. To prevent the occurrence of potato weeds, a method was
developed to manipulate soil-frost depths by artificially controlling snowcover thickness, guided by a simple numerical model
that simulates soil freezing-thawing processes using daily mean air temperature and snowcover thinckness as input variables.
The method involves removal of snowcover to expose the soil surface in the beginning of winter until the soil freezes to a
sufficient depth. After that time, snow is deposited back or allowed to accumulate naturally to prevent further penetration
of frost, which may cause undesirable delay in the seeding of spring crops. Field trials indicated that the model predicted
frost depths within several centimeters of observed values, when measured temperature and snowcover thickness were used as
model input. Based on the field and laboratory data, a soil temperature of −3°C is necessary for complete elimination of potato
tubers. To achieve this temperature in potato-burial zones without causing excessive freezing, an optimal frost depth is 0.3
to 0.4 m. The method is being adopted by progressive potato producers in the region, who use tractor-mounted snow ploughs
to manipulate snowcover over a large scale. This is an emerging new technology for agricultural adaptation to climate variability. 相似文献