154 research outputs found
Anguillid Eels as a Model Species for Understanding Endocrinological Influences on the Onset of Spawning Migration of Fishes
No full textSIMPLE SUMMARY: Endocrine regulation has been thought to play a major role in the onset of migration. Anguillid eels provide a good model for studying the onset mechanisms of migrations to breeding areas, because the process of the onset of migration occurs in inland waters. In this review, we summarize information about the silvering process in anguillid eels and the dynamics of mRNA expression of neurohormones and pituitary hormones, thyroid hormones, and sex steroids associated with the onset of the spawning migration. We also provide new results. Because 11-KT drastically increases during silvering, the role of 11-KT in the onset of spawning migration was discussed in detail. ABSTRACT: Anguillid eels are the iconic example of catadromous fishes, because of their long-distance offshore spawning migrations. They are also a good model for research on the onset mechanisms of migrations to breeding areas, because the migrations begin in inland waters. When eels transform from yellow eels to silver eels, it is called silvering. Silver eels show various synchronous external and internal changes during silvering, that include coloration changes, eye-size increases, and gonadal development, which appear to be pre-adaptations to the oceanic environment and for reproductive maturation. A strong gonadotropic axis activation occurs during silvering, whereas somatotropic and thyrotropic axes are not activated. Among various hormones, 11-ketotestosterone (11-KT) drastically increases during spawning migration onset. Gradual water temperature decreases simulating the autumn migratory season, inducing 11-KT increases. Administration of 11-KT appeared to cause changes related to silvering, such as early-stage oocyte growth and eye enlargement. Moreover, 11-KT may be an endogenous factor that elevates the migratory drive needed for the spawning migration onset. These findings suggested that water temperature decreases cause 11-KT to increase in autumn and this induces silvering and increases migratory drive. In addition, we newly report that 11-KT is associated with a corticotropin-releasing hormone that influences migratory behavior of salmonids. This evidence that 11-KT might be among the most important factors in the spawning migration onset of anguillid eels can help provide useful knowledge for understanding endocrinological mechanisms of the initiation of spawning migrations
I remember entertainment at the Poston II internment camp
No full textSunkie Oye, a resident of Seabrook, recalls the three years her family was interned at the Poston II internment camp in the desert out west. Because of the war, her father had been incarcerated in Santa Fe, New Mexico, but was allowed to rejoin the family at Poston a year later. When he arrived, he recruited volunteers to help build an ampitheater for entertainment. Among the internees at Poston were professional actors, actresses, and costume designers. Everyone chipped in to put on shows and skits. Sunkie was an accomplished Japanese classical dancer and played the shamisen well. She remembers how much fun she had performing on the stage that her father had helped design and build. The Seabrook Educational and Cultural Center has been soliciting current and past residents of Seabrook Farms for an "I remember" project. Residents are asked to create narratives regarding their experiences at Seabrook Farms. These memories help preserve the history and multi-cultural heritage of Seabrook Farms
わたしのくすり箱 絵本の窓から眺めたこと
No full textapplication/pdfMore than forty picturebooks were brought to the author while she was in hospital for treatment of cancer. The paper tells how picturebooks supported her in the struggle with fear caused by the disease, and talks about the medicinal effect picturebooks may have. The picturebooks referred to in the paper include Errol Le Cain’s Mr Mistoffelees with Mungojerrie and Rumpelteazer, Margaret Wise Brown’s Good Night, Moon, Antoine de Saint-Exupéry’s The Little Prince, Verma Aardema’s Bringing the Rain to Kapiti Plain, and so on, along with works by Japanese artists, such as Mitsumasa Anno, Ryusuke Saito, Heijiro Taki, and Hideko Ise.departmental bulletin pape
Profiles of thyroid hormones and mRNA expression for thyroid stimulating hormone in Japanese eel during downstream migration
No full textEel Cruise XVIII
No full text航海番号: KH-12-2 Leg 1, Leg2 ; 航海日程: May 13 - June 1, 2012 ／ June 6 - June 28, 201
Effects of soil water content and grass recycling on N2O emission in an urban lawn under laboratory incubation study
No full textDielectric study of acetophenone and its derivatives
No full textComplex permittivity measurements on acetophenone and its derivatives o-hydroxybenzaldehyde, o-methylacetophenone, and o-hydroxyacetophenone are performed at frequencies between 1 MHz and 20 GHz at temperatures from 273 to 323 K. The parameters obtained from the fitting of the complex permittivity are analyzed in order to study the effects of the hydroxyl group within a molecule on the dielectric relaxation phenomenon in these liquids. The analysis indicates that dynamical properties are affected not only by the intermolecular hydrogen bond but also by the slight change in molecular structure. This conclusion differs from those obtained from the results of other experiments
N2O emissions during the freezing and thawing periods from six fields in a livestock farm, southern Hokkaido, Japan
No full textIn many countries, high nitrous oxide (N2O) emissions have been observed during soil freezing and thawing periods. Quantification of those emissions is crucial to evaluate annual N2O emissions. For this study, we measured N2O and NO fluxes along with soil N2O concentrations at a corn field and five grasslands during a winter-spring period in Southern Hokkaido, Japan. We also measured denitrification activities of the soils from those sites. During the observation period, the soils froze to a maximum depth of 370 mm under saturated conditions and the lowest soil temperature at a 50 mm depth was -4.5℃. After 6 March 2005, daily air temperature rose above 0℃, but the soil temperature remained approximately 0℃ for about two weeks. These two weeks were defined as the 'transition period,' while the periods before and after the transition period were defined as the 'freezing' and the 'thawing' periods, respectively. During the freezing and transition periods, N2O concentration increased in the frozen soils relative to the unfrozen soils and the highest values were observed in the frozen soils during the transition period. During the thawing period, the N2O concentration in the soils decreased. N2O emissions were much higher during the thawing period than during the freezing and transition periods, and remarkably higher N2O emissions were observed at the corn site compared to those at the grassland sites. NO emissions were also observed during the thawing period but at much lower levels than N2O emissions at all the sites. N2O-N/NO-N ratio exceeded one at all the sites during the entire period, indicating N2O production through denitrification. At the corn site, denitrification activity was much lower and N2O/(N2O+N2) was much higher than at the grasslands. The result indicated that high N2O emissions at the corn site were caused by complementary processes: (1) high accumulated N2O through denitrification in the frozen soil during the freezing and transition periods, and (2) low N2O reduction rate during the thawing period
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