361 research outputs found

    Vent Fauna in the Mariana Trough

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    Ecological and growth characteristics of trees after resumption of management in  abandoned substitution forest in Japan

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    Since the 1950s, secondary (substitution) forests known as Satoyama woods have been abandoned due to changes in human lifestyle. The aim of this study was to investigate the relationships between human activity and substitution forests to better understand the traditional management required to prevent succession to evergreen forest. An objective was to identify the tree species, their numbers of trunks (NT), and the basal area (BA) (collectively, the stand density) in the woods today, half a century after people abandoned the substitution forests. Another goal was to compare, over a six-year period, the figures for total NT, BA, and the number of living, dead or fallen trunks between an abandoned substitution forest (a control plot) and a mown plot. NT decreased from 700 trunks/ha to 600 trunks/ha on the control, and from 600 trunks/ha to 400 trunks/ha on the mown plot at ground level over six years. The total BA increased annually on the control plot but decreased from 48m2/ha to 38m2/ha on the mown plot over six years. Many hydrophytes (Alnus japonica, etc.), Quercus serrata, and other trees species were found dead on the mown plots. All Quercus myrsinaefolia (evergreen trees) were still alive by the sixth year. These results demonstrate that the vegetation in these forests succeeded to Quercetum myrsinaefoliae, Tyoische Subass., which is therefore shown as the potential vegetation of succession over this timescale. If it is desired to maintain the traditional vegetation type, then the study suggests that it is necessary to manage the substitution forest. This is in order to prevent succession to evergreen forest and can be achieved by cutting Pleioblastus chino, climbing plants, and shade plants (evergreen trees)

    Cellular DBP and E4BP4 proteins are critical for determining the period length of the circadian oscillator

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    AbstractThe phenotypes of mice carrying clock gene mutations have been critical to understanding the mammalian clock function. However, behavior does not necessarily reflect cell-autonomous clock phenotypes, because of the hierarchical dominance of the central clock. We performed cell-based siRNA knockdown and cDNA overexpression and monitored rhythm using bioluminescent reporters of clock genes. We found that knockdown of DBP, D-box positive regulator, in our model led to a short-period phenotype, whereas overexpressing of DBP produced a long-period rhythm when compared to controls. Furthermore, knockdown and overexpressing of E4BP4, D-box negative regulator, led to an opposite effect of DBP. Our experiments demonstrated that D-box regulators play a crucial role in determining the period length of Per1 and Per2 promoter-driven circadian rhythms in Rat-1 fibroblasts

    Long-Term Effect of Enzyme Replacement Therapy with Fabry Disease

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    Objective. To determine the effects of enzyme replacement therapy (ERT) on the hearing acuity in patients with Fabry disease. Materials. The study sample comprised 34 ears of 17 affected patients who underwent pure-tone audiometry before and after ERT. Methods. The patients were studied in relation to factors such as changes in hearing, presence of accompanying symptoms, status of renal and cardiac function, age, and gender. Data of pure-tone audiometry obtained before ERT and at the final examination were compared. Results. At the end of the follow-up period, no significant worsening of hearing acuity was noted at the end of the follow-up period. SSNHL was detected in 10 ears of 6 patients. Steroid therapy successfully cured the disease in 9 of the 10 ears. Conclusions. No significant worsening of hearing acuity was noted from the beginning to the end of ERT. The rate of improvement in SSNHL of Fabry disease was excellent in the treated patients. Hearing loss is a factor that causes marked deterioration of the patients’ quality of life, and it is desirable that the hearing acuity of patients be periodically evaluated and prompt treatment of SSNHL be administered, if available

    Transplantation of a human induced pluripotent stem cell-derived airway epithelial cell sheet into the middle ear of rats

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    [Introduction] Early postoperative regeneration of the middle ear mucosa is essential for the prevention of postoperative refractory otitis media and recurrent cholesteatoma. As a means for intractable otitis media management, we focused on human induced pluripotent stem cell (hiPSC)-derived airway epithelial cells (AECs), which have been used in upper airway mucosal regeneration and transplantation therapy. In this study, we transplanted hiPSC-derived AECs into the middle ear of immunodeficient rats. [Methods] Following the preparation of AEC sheets from hiPSCs, the bilateral middle ear mucosa of X-linked severe combined immunodeficient rats was scraped, and the AEC sheets were transplanted in the ears unilaterally. [Results] Human nuclear antigen (HNA)-positive ciliated cells were observed on the transplanted side of the middle ear cavity surface in three of six rats in the 1-week postoperative group and in three of eight rats in the 2-week postoperative group. No HNA-positive cells were found on the control side. The percentage of HNA-positive ciliated cells in the transplanted areas increased in the 2-week postoperative group compared with the 1-week group, suggesting survival of hiPSC-derived AECs. Additionally, HNA-positive ciliated cells were mainly located at sites where the original ciliated cells were localized. Immunohistochemical analysis showed that the transplanted AECs contained cytokeratin 5- and mucin 5AC-positive cells, indicating that both basal cells and goblet cells had regenerated within the middle ear cavity. [Conclusions] The results of this study are an important first step in the establishment of a novel transplantation therapy for chronic otitis media

    Population history of deep-sea vent and seep Provanna snails (Mollusca: Abyssochrysoidea) in the northwestern Pacific

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    Background Gastropods of the genus Provanna are abundant and widely distributed in deep-sea chemosynthetic environments with seven extant species described in the northwestern Pacific. Methods We investigated the population history and connectivity of five Provanna species in the northwestern Pacific through population genetic analyses using partial sequences of the cytochrome c oxidase subunit I gene. Results We found that P. subglabra, the most abundant and genetically diverse species, is genetically segregated by depth. Among the five species, the three comparatively shallower species (P. lucida, P. kuroshimensis, P. glabra) had a more constant demographic history compared to the deeper species (P. subglabra, P.  clathrata). Discussion Environmental differences, especially depth, appears to have a role in the segregation of Provanna snails. The population of P. clathrata in the Irabu Knoll appears to have expanded after P. subglabra population. The remaining three species, P. lucida, P. kuroshimensis, and P. glabra, are only known from a single site each, all of which were shallower than 1,000 m. These data indicate that Provanna gastropods are vertically segregated, and that their population characteristics likely depend on hydrothermal activities

    トウキョウノウギョウダイガクセタガヤキャンパス ノ チョウルイソウ

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    東京農業大学世田谷キャンパスにおいて鳥類のラインセンサスとポイントセンサスを実施し,同様の調査を行った馬事公苑と種構成や個体数を比較した。1年と3カ月にわたる両調査地の調査で,計24科42種が確認された。2つの調査地間で,2種類のセンサス法による月を単位とした種数,個体数,Shannon-Wienerの多様度指数を比較した結果,世田谷キャンパスに比べ馬事公苑で種数と個体数が多く,多様度指数が高い傾向が認められた。この理由として,馬事公苑は外周を階層構造の発達した樹林が取り囲むなど緑地の占める面積割合が高く,まとまった落葉広葉樹林や水辺,芝地など多様な環境が含まれることが影響していると考えられた。また,世田谷キャンパス全体を25m×25mの区画に区切り,シジュウカラ,メジロ,コゲラなど7種の観察総数と緑被率との関系を解析した結果,すべての種で緑被率と観察総数との間に正の相関が認められた。キャンパス内の鳥類の多様性を高めるためには,落葉層を含む下層植生の発達したまとまった樹林を設けることが有効であると考えられる。The bird census was studied for approximately 1 year starting in January 2008 at the Tokyo University of Agriculture and Baji-Koen located in urban Tokyo. To assess the number of species and individuals, a line-census survey and fixed-point survey were conducted weekly during the study period. The census data confirmed 42 species and the avifauna consisted of resident birds including tree sparrows, bulbuls, white-eyes, great tits that adapted to the urban environment, and a small number of migrating birds. The avian species were significantly more diverse at Baji-Koen than at the university campus according to the two census surveys. In addition, we assessed the influence of the extent of green cover on the abundance of birds at the campus and found a correlation between the percentage of green cover and the abundance of 7 bird species. The results suggest that habitat characteristics such as the expanse of green cover influence bird diversity and that greater vegetative coverage is required to achieve greater diversity in campus avifauna
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