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131.
Weekly variations in density of juvenile yellowfin goby Acanthogobius flavimanus with a variety of environmental variables (e.g. water temperature, salinity and transparency, and prey density) were investigated
on a tidal mudflat within the Tama River estuary, central Japan, from March to July 2001. Metamorphosing newly settled juveniles
occurred from mid-March to late May. Metamorphosed benthich juveniles first appeared in late March, the density sharply increasing
to a peak (67.0 ind./m2) in early May but rapidly decreasing to less than 10% of that two weeks later. No consistent relationships were apparent
between short-term variations in fish density by developmental stages and water temperature, or salinity. In contrast, a weak
negative relation was found between juvenile density and water transparency. Further, benthic juvenile density was positively
related to short-term fluctuations of errant polychaetes, which is one of the main prey items. 相似文献
132.
133.
Youichi Ikeshita Yuri Kanamori Nobuyuki Fukuoka Jun Matsumoto Yasutaka Kano 《Scientia Horticulturae》2010
To investigate the effects of night-time temperature on cell and fruit size, and sugar accumulation in watermelon fruit, fruits were treated with high night-time temperatures in a greenhouse. The minimum night-time ambient temperature of the heating box (18 °C) was approximately 6 °C higher than that of the control. The length, diameter and weight of heat-treated fruit at the end of heating treatment, 16 days after anthesis (DAA), were significantly greater than that of control fruit, but those at harvesting, 42 DAA, were almost the same in both treatments. Mean cell size of the outer portion of heat-treated fruit at 16 DAA was significantly larger than that of the control. Cell size of the fruits at 42 DAA did not differ between heat-treated and control fruits. Sucrose, glucose and fructose content of fruit at 16 DAA did not differ between heat-treated and control fruit. However, sucrose content of the outer portion of heat-treated fruit was 162% of that of control fruit at 42 DAA. Glucose and fructose contents at 42 DAA did not differ between heat-treated and control fruit, except glucose content of outer portion. 相似文献
134.
Wakabayashi N Tsujino M Tajiri M Taki M Koshino A Ikeda H Fukushima N Tsujiuchi T 《Journal of toxicologic pathology》2010,23(1):63-66
Lysophosphatidic acid (LPA) is a bioactive phospholipid that stimulates cell proliferation and migration, and protects cells from apoptosis. It interacts with specific G protein-coupled transmembrane receptors. Recently, frequent mutations of the LPA receptor-1 (LPA1) gene were detected in rat lung adenocarcinomas induced by N-nitrosobis(2-hydroxypropyl)amine (BHP). In this study, to evaluate the involvement of other LPA receptor gene alterations during lung carcinogenesis, we investigated mutations of the LPA2, LPA3, LPA4 and LPA5 genes in lung adenocarcinomas induced by BHP in rats. Fifteen male Wistar rats, 6 weeks of age, were given 2000 ppm BHP in their drinking water for 12 weeks and then maintained without further treatment until sacrifice at 25 weeks, and 15 adenocarcinomas were obtained. Genomic DNAs were extracted from frozen tissues, and the LPA2, LPA3, LPA4 and LPA5 genes were examined for mutations, using polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis. No mutations of LPA2, LPA3, LPA4 and LPA5 were detected in the 15 adenocarcinomas. These results suggest that alterations due to LPA2, LPA3, LPA4 and LPA5 gene mutations might not be involved in the development of lung adenocarcinomas induced by BHP in rats. 相似文献
135.
Toshihiro Yokoo Kouki Kanou Masato Moteki Hiroshi Kohno Prasert Tongnunui Hisashi Kurokura 《Fisheries Science》2012,78(2):237-247
We describe the assemblage structures and spatial distributions of juvenile and adult small gobioid fishes in a mangrove estuary
in Trang Province, southern Thailand. The 11,183 gobioid juveniles and adults collected during the present study were classified
into three families, 19 genera and 36 species. The three most dominant species were Pandaka
pygmaea, Acentrogobius kranjiensis and Acentrogobius malayanus, which accounted for 75.9, 15.0 and 3.8% of the total number of gobioids collected, respectively. Spatial differences in
gobioid fish assemblages were found in a mangrove estuary and its adjacent marine area. The diverse gobioid fauna with a variety
of lifestyles found at muddy-bottomed, low-salinity stations, which were mainly upper- and middle-reach stations, can be partly
accounted for by the existence of the various microhabitats in muddy-bottomed areas around mangroves. These microhabitats
may contribute to local fish catches because gobies are of great significance as prey species for piscivores, including commercially
important fish in mangrove estuaries. The abundance of each gobioid species would contribute to the development of rational
methods for assessing the effectiveness of mangrove conservation and rehabilitation programs. 相似文献
136.
Hideaki Tanoue Teruhisa Komatsu Takurou Tsujino Ippei Suzuki Masayoshi Watanabe Hideki Goto Nobuyuki Miyazaki 《Fisheries Science》2012,78(3):533-538
The feeding events of wild animals have been widely researched in recent decades. The use of invasive methods to determine
stomach contents in which the fish is killed can, however, be considered to be unjustifiable in the case of an endangered
fish, such as the Japanese late. Here, we report on a method that can be used to verify feeding events of a fish species without
the need for killing the fish through the use of a high-speed video camera and a three-axis micro-acceleration data-logger.
High-quality images obtained by the video showed that the fish opens its mouth with a quick downward movement of the mandibles
and ingests prey via suction feeding. The movement of the mandibles was also simultaneously recorded by changes in the three-axis
accelerations obtained by the logger attached to the dorsum. We attached the logger with an automatic release system to the
dorsum of one captive Japanese lates and two wild fish together with an acoustic transmitter and then released the fish in
the Shimanto River in Japan. After retrieving the logger, the movement records of the fish obtained by the three-axis accelerometer
showed the same pattern of feeding events as those in captivity. A total of 13 feeding events at night and five during the
daytime were obtained for the three fish during a total 129.7 h of recording. 相似文献
137.
Chotichayapong C Wiengsamut K Chanthai S Sattayasai N Tamiya T Kanzawa N Tsuchiya T 《Fish physiology and biochemistry》2012,38(5):1533-1543
Myoglobin from Asian swamp eel Monopterus albus was purified from fish muscle using salt fractionation followed by column chromatography and molecular filtration. The purified Mb of 0.68?mg/g wet weight of muscle was determined for its molecular mass by MALDI-TOF-MS to be 15,525.18?Da. Using isoelectric focusing technique, the purified Mb showed two derivatives with pI of 6.40 and 7.12. Six peptide fragments of this protein identified by LC-MS/MS were homologous to Mbs of sea raven Hemitripterus americanus, yellowfin tuna Thunnus albacores, blue marlin Makaira nigicans, common carp Cyprinus carpio, and goldfish Carassius auratus. According to the Mb denaturation, the swamp eel Mb had thermal stability higher than walking catfish Clarias batrachus Mb and striped catfish Pangasius hypophthalmus Mb, between 30 and 60?(°)C. For the thermal stability of Mb, the swamp eel Mb showed a biphasic behavior due to the O(2) dissociation and the heme orientation disorder, with the lowest increase in both Kd(f) and Kd(s). The thermal sensitivity of swamp eel Mb was lower than those of the other Mbs for both of fast and slow reaction stages. These results suggest that the swamp eel Mb globin structure is thermally stable, which is consistent with heat-tolerant behavior of the swamp eel particularly in drought habitat. 相似文献
138.
Atsuya Yamashita Yuusuke Fujimoto Mayumi Tamaki Andi Setiawan Tomohisa Tanaka Kaori Okuyama-Dobashi Hirotake Kasai Koichi Watashi Takaji Wakita Masaaki Toyama Masanori Baba Nicole J. de Voogd Shinya Maekawa Nobuyuki Enomoto Junichi Tanaka Kohji Moriishi 《Marine drugs》2015,13(11):6759-6773
The current treatments of chronic hepatitis B (CHB) face a limited choice of vaccine, antibody and antiviral agents. The development of additional antiviral agents is still needed for improvement of CHB therapy. In this study, we established a screening system in order to identify compounds inhibiting the core promoter activity of hepatitis B virus (HBV). We prepared 80 extracts of marine organisms from the coral reefs of Indonesia and screened them by using this system. Eventually, two extracts showed high inhibitory activity (>95%) and low cytotoxicity (66% to 77%). Solvent fractionation, column chromatography and NMR analysis revealed that 3,5-dibromo-2-(2,4-dibromophenoxy)-phenol (compound 1) and 3,4,5-tribromo-2-(2,4-dibromophenoxy)-phenol (compound 2), which are classified as polybrominated diphenyl ethers (PBDEs), were identified as anti-HBV agents in the extracts. Compounds 1 and 2 inhibited HBV core promoter activity as well as HBV production from HepG2.2.15.7 cells in a dose-dependent manner. The EC50 values of compounds 1 and 2 were 0.23 and 0.80 µM, respectively, while selectivity indexes of compound 1 and 2 were 18.2 and 12.8, respectively. These results suggest that our cell-based HBV core promoter assay system is useful to determine anti-HBV compounds, and that two PBDE compounds are expected to be candidates of lead compounds for the development of anti-HBV drugs. 相似文献
139.
140.