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131.
In order to determine the effects of ghost fishing by lost gill nets, the relationship was examined between soak time and
number of enmeshed animals in experimentally lost gill nets by using diving observations. Two experimental gill nets were
set at 13 m depth in Tateyama Bay, Chiba Prefecture, Japan for approximately 200 days. One gill net was deployed in a small
trough surrounded by artificial reefs, and the other was deployed on an adjacent open sandy bed. Twelve species of crustaceans,
six species of gastropods, and five species of bony fish were enmeshed in the experimental gill nets. The number of enmeshed
animals in the artificial reef gill net was substantially larger than that in the sandy bed gill net. The number of enmeshed
animals in the experimental gill nets increased rapidly within one month after deployment, and then declined gradually showing
fluctuations caused by the decrease in newly enmeshed animals, and the drop off from gill nets caused by the decomposition
of dead animals. The decrease in the number of enmeshed animals was expressed by logarithmic equations, and based on these
equations, the duration of capture function for the lost gill nets was calculated to be 284–561 days in the artificial reef
gill net and 200 days in the sandy bed gill net. The duration of capture function for the lost gill nets for non-commercial
by-catch species such as small crustaceans and gastropods was longer than for commercial species such as Japanese spiny lobster
and bony fish. 相似文献
132.
Gaudi BS Bennett DP Udalski A Gould A Christie GW Maoz D Dong S McCormick J Szymanski MK Tristram PJ Nikolaev S Paczynski B Kubiak M Pietrzynski G Soszynski I Szewczyk O Ulaczyk K Wyrzykowski L;OGLE Collaboration Depoy DL Han C Kaspi S Lee CU Mallia F Natusch T Pogge RW Park BG;MuFUN Collaboration Abe F Bond IA Botzler CS Fukui A Hearnshaw JB Itow Y Kamiya K Korpela AV Kilmartin PM Lin W Masuda K Matsubara Y Motomura M Muraki Y Nakamura S Okumura T Ohnishi K Rattenbury NJ Sako T Saito T Sato S 《Science (New York, N.Y.)》2008,319(5865):927-930
Searches for extrasolar planets have uncovered an astonishing diversity of planetary systems, yet the frequency of solar system analogs remains unknown. The gravitational microlensing planet search method is potentially sensitive to multiple-planet systems containing analogs of all the solar system planets except Mercury. We report the detection of a multiple-planet system with microlensing. We identify two planets with masses of approximately 0.71 and approximately 0.27 times the mass of Jupiter and orbital separations of approximately 2.3 and approximately 4.6 astronomical units orbiting a primary star of mass approximately 0.50 solar mass at a distance of approximately 1.5 kiloparsecs. This system resembles a scaled version of our solar system in that the mass ratio, separation ratio, and equilibrium temperatures of the planets are similar to those of Jupiter and Saturn. These planets could not have been detected with other techniques; their discovery from only six confirmed microlensing planet detections suggests that solar system analogs may be common. 相似文献
133.
Chromosomal locations of the murine T-cell receptor alpha-chain gene and the T-cell gamma gene 总被引:11,自引:0,他引:11
D M Kranz H Saito C M Disteche K Swisshelm D Pravtcheva F H Ruddle H N Eisen S Tonegawa 《Science (New York, N.Y.)》1985,227(4689):941-945
Two independent methods were used to identify the mouse chromosomes on which are located two families of immunoglobulin (Ig)-like genes that are rearranged and expressed in T lymphocytes. The genes coding for the alpha subunit of T-cell receptors are on chromosome 14 and the gamma genes, whose function is yet to be determined, are on chromosome 13. Since genes for the T-cell receptor beta chain were previously shown to be on mouse chromosome 6, all three of the Ig-like multigene families expressed and rearranged in T cells are located on different chromosomes, just as are the B-cell multigene families for the Ig heavy chain, and the Ig kappa and lambda light chains. The findings do not support earlier contentions that genes for T-cell receptors are linked to the Ig heavy chain locus (mouse chromosome 12) or to the major histocompatibility complex (mouse chromosome 17). 相似文献
134.
Matsubara H Yoshimoto S Saito H Jianglin Y Tanaka Y Noda S 《Science (New York, N.Y.)》2008,319(5862):445-447
Shorter-wavelength surface-emitting laser sources are important for a variety of fields, including photonics, information processing, and biology. We report on the creation of a current-driven blue-violet photonic-crystal surface-emitting laser. We have developed a fabrication method, named "air holes retained over growth," in order to construct a two-dimensional gallium nitride (GaN)/air photonic-crystal structure. The resulting periodic structure has a photonic-crystal band-edge effect sufficient for the successful operation of a current-injection surface-emitting laser. This represents an important step in the development of laser sources that could be focused to a size much less than the wavelength and be integrated two-dimensionally at such short wavelengths. 相似文献
135.
Masaharu Komatsu Naoki Ichiyama Takashi Kurimoto Shota Takumi Kazuhiro Shiozaki Yasumasa Sugiyama Tatsuhiko Furukawa Seiichi Ando Saki Itonori Hiroaki Saito 《Fisheries Science》2013,79(2):313-320
We have previously established the method for isolation of ceramide aminoethylphosphonate (CAEP) from jumbo flying squid Dosidicus gigas. In this study, we performed a MTT assay to evaluate the safety of CAEP to the cell lines for the application to health food and supplements. The CAEP did not show any cytotoxicity to various HEK293-transfectant cells. Next, we elucidated the positive function of CAEP to the somatic cells. Recently, we have reported that hepatotoxin microcystin-LR was taken up into the hepatocytes mediated by hepatocellular uptake transporters OATP1B1 and OATP1B3, and the cells were induced cytotoxicity subsequently. Cytotoxicity of microcystin-LR to permanently OATP1B3-expressing HEK293-OATP1B3 cells rather than to HEK293-OATP1B1 cells was preferentially attenuated by CAEP in a concentration-dependent manner. In addition, the enzyme activity of serine/threonine phosphatase, which was inhibited by microcystin-LR, was recuperated by co-exposure to CAEP. Furthermore, microcystin-LR-induced cellular protein phosphorylation were disrupted by CAEP exposure. These results suggested that CAEP is a promising remedy and/or preventive medicine for liver damage with microcystin-LR. 相似文献
136.
Elisabete Yurie Sataque Ono Elaine Cunha Moreno Mario Augusto Ono Carolina Nachi Rossi Gervásio Hitoshi Saito Édio Vizoni Yoshitsugu Sugiura Elisa Yoko Hirooka 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(4):653-660
In this study the effect of different cropping systems and crop successions was evaluated on natural Fusarium sp. contamination and fumonisin levels in corn. The cropping systems consisted of a conventional and no-tillage area cultivated
with corn in the summer following either oats or fallow in the winter (2006 and 2007 growing seasons). In addition, the effect
of applying nitrogen fertilizer (0, 22.5, 45.0, 90.0 and 90.0 kg ha−1 nitrogen supplemented with potassium oxide) on fumonisin contamination was evaluated in the 2006 growing season. Fusarium sp. was detected in 90% samples in 2006 and in 100% samples in 2007. In both growing seasons, no-till corn following oats
showed the highest mean fumonisin levels and differed significantly (P < 0.05) from all the others (2006) and from conventional till corn following either oats or fallow in the winter (2007).
Fumonisin levels ranged from 0.13 to 19.52 μg g−1 (mean 6.97 μg g−1) and from 3.70 to 7.75 μg g−1 (mean 6.29 μg g−1) in no-till corn following oats from the 2006 and 2007 growing seasons, respectively. Plots treated with 0 kg ha−1 and 22.5 kg ha−1 nitrogen showed the highest mean fumonisin levels and differed significantly from those with 45.0 and 90 kg ha−1 nitrogen. Fumonisin levels correlated negatively (P < 0.05) with the nitrogen fertilization rates. Although no-till is advantageous from a soil conservation standpoint, it may
enhance the potential for fumonisin contamination in corn. 相似文献
137.
A stable Leifsonia xyli subsp. xyli GFP‐tagged strain reveals a new colonization niche in sugarcane tissues 下载免费PDF全文
M. C. Quecine T. M. Silva G. Carvalho S. Saito M. Mondin N. S. Teixeira‐Silva L. E. A. Camargo C. B. Monteiro‐Vitorello 《Plant pathology》2016,65(1):154-162
Ratoon stunting disease (RSD), caused by the bacterium Leifsonia xyli subsp. xyli (Lxx), is one of the most economically important diseases of sugarcane worldwide. Because knowledge on the interaction of Lxx with its host at the microscopic level is limited, the development of tools to monitor Lxx during the colonization process could shed new light on the processes that control disease development. In this investigation, a transformation protocol was optimized and a mutant Lxx strain engineered that stably expressed the gfp gene in sugarcane tissues. In vitro, the growth of the mutant did not differ from that of the wild type. Also, plants inoculated with both strains showed comparable growth and development when analysed 180 days after inoculation (dai). Fluorescence microscopy of roots, stalks, meristems and leaf tissues of Lxx‐GFP‐inoculated plants was performed at 180 dai. In the leaves, Lxx‐tagged cells were observed within the xylem vessels as has been described before but, in addition, they were found in a new niche within the host tissues, in the mesophyll and in the bundle sheath cells surrounding the vascular system. This finding indicates that Lxx is able to move from the xylem to the parenchyma of the leaf cells. This first report of an Lxx mutant expressing a heterologous gene revealed that colonization of sugarcane by this pathogen is not limited to the xylem vessels as commonly reported. 相似文献
138.
Coral reefs are considered to be a source of atmospheric carbon dioxide because of their high calcium carbonate production and low net primary production. This was tested by direct measurement of diurnal changes in the partial pressure of carbon dioxide (Pco(co2)) in reef waters during two 3-day periods, one in March 1993 and one in March 1994, on Shiraho reef of the Ryukyu Islands, Japan. Although the Pco(co2) values in reef waters exhibited large diurnal changes ranging from 160 to 520 microatmospheres, they indicate that the reef flat area is a net sink for atmospheric carbon dioxide. This suggests that the net organic production rate of the reef community exceeded its calcium carbonate production rate during the observation periods. 相似文献
139.
140.
Onuma M Nagamine T Nakaya Y Neagari Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(9):1169-1175
The captive breeding program of the Okinawa rail started in 2008. For successful captive breeding, information related to reproduction, such as age at sexual maturity, testicular cycles and ovulatory cycles, is essential to predict when reproduction is possible and when certain reproductive behaviors are most likely to occur. We made gross and histological observations of the reproductive organs of Okinawa rails to gain understanding of sexual maturity, the testicular cycle and the ovulatory cycle. We found that the weight of the testis was smallest in December and largest in March. Changes in the diameter of the seminiferous tubule showed the same pattern. Mature sperm were observed from March to June. The heaviest ovary was observed in April. A single peak of reproduction, from March to April, was observed in males and females. Our observations suggested that the Okinawa rail is a seasonal breeder. Establishing suitable breeding pairs will be critical to ensure success of the Okinawa rail captive breeding program. Our results suggested that pairing must be started before March. If supportive breeding is used, semen should be collected from March to June and artificial insemination conducted in April. 相似文献