Seasonal changes of some environmental factors around the moss vegetation near Syowa Station,East Antarctica

Seasonal changes of environmental factors around the moss vegetation such as snow drift, water supply and temperature were investigated in the vicinity of Syowa Station from February 1983 to January 1984. Topographical features around the vegetation are basically concerned in the formation of snow drift. After late September the depth of snow cover gradually decreased and in October the vegetation was partially exposed from snow. In early December water traces were recognized beneath the snow. In contrast with a decay of the snow drift, the water content of moss turves increased and reached a maximum value of 125.8% during the period from late December to early January. Each small moss colony composing the vegetation had its own pattern of water supply which was considered to be related with small streams from the drift. Referring to the water supply, temperature profile and moss growth were also discussed

The Environmental and Genetic Approach for Life on Earth (EAGLE) project

AbstractThe Transdisciplinary Research Integration Center (TRIC) advances the basic objectives under the umbrella of the Research Organization of Information and Systems (ROIS). The TRIC co-ordinates the development of novel fields of research within the Inter-University Research Institute Corporation of Japan. The TRIC program fosters integrated research and develops information platforms that support the quest for new paradigms in the fields of Earth science and life systems. The project, “Environmental and Genetic Approach for Life on Earth with a Study of Relevant Modeling and Prediction Techniques (EAGLE)” began under the TRIC program in 2005. The goal of the EAGLE project is to improve our understanding of ecosystems on Earth and to investigate the mechanisms leading to the evolution of life and the adaptation of species as a result of past environmental changes. The EAGLE project is also positioned as a national project of the “Microbiological and Ecological Responses to Global Environmental Changes in polar regions (MERGE) program”, so called, “MERGE-Japan” which was initiated as part of the International Polar Year (IPY, 2007–2008). A general outline of the current achievements and discussion of the EAGLE project during the IPY period are presented in this progress report

Notes on floral traits and gender expression of Dryas octopetala under a simulated environmental change

This study presents empirical data for variations of floral traits and gender expression in Arctic Dryas octopetala L. under a simulated environmental amelioration using an open-top chamber (OTC). The short-term experiment (from 8 August 1997 to 2 August 1998) demonstrated in Ny-Alesund, Svalbard that dry weights of gynoecium, peduncle, and hermaphrodite flowers were significantly heavier, whereas petal and androecium weight were significantly lighter in OTC-manipulated shoots than in controls. As a result, "femaleness" (dry-weight allocation to the female organs) showed a significantly higher value in OTC-manipulated shoots as compared to the controls. Moreover, femaleness was significantly positively correlated with flower weight both in OTC-manipulated and control shoots. Thus, it was experimentally demonstrated that the gender as a reproductive effort of D. octopetala flowers changed from male- to female-biased expression under a less stressful condition

Trace Elements in the Hairs of Wintering Members of the 13th Japanese Antarctic Research Expedition.

The concentrations of six trace elements, Hg, Au, Cu, Zn, Sb and Br, in the hairs collected from 10 members of the wintering party of the 13th Japanese Antarctic Research Expedition (1971-1973) during their stay in Antarctica, were measured by neutron activation analysis. The mercury concentration in the hair decreased and its distribution range became narrower during one year-long stay in Antarctica. And its concentration increased and scattered over a wide range again after the party members returned to Japan. The extremely high concentration of antimony suggests that the hair was contaminated by enviromental pollution on board the icebreaker FUJI. No obvious trend was found in the concentrations of other elements during the stay in Antarctica

Mechanism of tumor‐suppressive cell competition in flies

Oncogenic mutations often trigger antitumor cellular response such as induction of apoptosis or cellular senescence. Studies in the last decade have identified the presence of the third guardian against mutation‐induced tumorigenesis, namely “cell competition.” Cell competition is a context‐dependent cell elimination whereby cells with higher fitness eliminate neighboring cells with lower fitness by inducing cell death. While oncogene‐induced apoptosis or oncogene‐induced senescence acts as a cell‐autonomous tumor suppressor, cell competition protects the tissue from tumorigenesis via cell‐cell communication. For instance, in Drosophila epithelium, oncogenic cells with cell polarity mutations overproliferate and develop into tumors on their own but are eliminated from the tissue when surrounded by wild‐type cells. Genetic studies in flies have unraveled that such tumor‐suppressive cell competition is regulated by at least three mechanisms: direct cell‐cell interaction between polarity‐deficient cells and wild‐type cells, secreted factors from epithelial cells, and systemic factors from distant organs. Molecular manipulation of tumor‐suppressive cell competition could provide a novel therapeutic strategy against human cancers

Morphological variation and taxonomic interpretation in the moss genus Bryum in Antarctica

The potential for morphological variation in Antarctic species of Bryum is evaluated and related to problems associated with taxonomic interpretation based on specimens from the Soya Coast, Mac. Robertson Coast, Vestfold Hills and Knox Coast. B. argenteum HEDW. Has been positively determined for Continental Antarctica from six localities on the Soya Coast and from Ross Island, southern Victoria Land. Specimens from the Vestfold Hills and Knox Coast considered with some reservation as this species are here referred to B. pseudotriquetrum (HEDW.) GAERTN, MEYER et SCHERB. B. pseudotriquetrum is widespread in the Antarctic region and includes many species formerly regarded as distinct taxa. Small specimens and those with physical damage to the upper parts of leaves may confused with B. argenteum. It is concluded that only two species of Bryum, B. argenteum and B. pseudotriquetrum, are represented in the Continental Antarctic flora, confirming H. OCHI\u27S (Mem. Natl Inst. Polar Res., Spec. Issue, 11, 70, 1979) taxonomic conclusion

On the structures of moss colony in the Yukidori Valley, Langhovde, East Antarctica

The moss vegetation developing in the Yukidori Valley, Langhovde, East Antarctica, was investigated as based on the samples in the vertical cross-section housed as the herbarium specimens to categorize the structure of the moss colony and to determine the specific composition. The vegetation consists of pure colonies of one species, and mixed colonies composed of two or rarely three moss species. Each colony was classified by species composition and degree of unevenness. The active zone, decomposed zone which were seen in the vertical cross-section, and epiphytic condition on the surface such as cyanobacteria and imperfect lichens, and rhizoidal layers in the inside of colony were determined and measured. Furthermore, the relationship between epiphytic condition and the thickness of the pure and mixed colonies was discussed taking account of ecological significances of these structural features

ダイ45ジ ナンキョク チイキ カンソクタイ ナツタイ ホウコク 2003-2004

本編は第45次南極地域観測隊夏隊行動の概要報告である.観測隊は総勢62名で構成され,このうち越冬隊は40名,夏隊は22名であった.他に越冬隊に2名,夏隊に6名が同行者として参加した.2003年11月14日,観測船「しらせ」は晴海を出港し,観測隊は11月28日,航空機でオーストラリアに入り,翌日「しらせ」に乗船した.「しらせ」は海洋観測を実施しつつ,12月14日には氷縁に到着し,24日には昭和基地に接岸した.夏期間は,昭和基地への物資輸送,同基地でのインテルサット衛星アンテナの建設,発電機のオーバーホール,エアロゾル観測小屋建設などの基地作業を行った.輸送量は空輸,氷上輸送,パイプ輸送を含めて,1107.2tであった.昭和基地では南極周回気球実験,回収気球実験,高々度気球によるオゾンゾンデ観測など大型気球実験が実施され,それぞれ成功した.その他,超伝導重力計観測,重力絶対測定,露岩域地形調査,潜水調査などを実施した.「しらせ」は帰路,海洋観測を実施しつつ,シドニーに到着し,観測隊は航空機により3月27日,全員成田に到着した.一方,ノボラザレフスカヤ基地からドームふじ観測拠点間の日本南極地域観測史上初めての航空機によるアクセスは往復便とも順調に行われ,第二期南極氷床深層掘削計画がスタートした.The summer activities in the 2003-2004 austral summer of the 45th Japanese Antarctic Research Expedition (JARE-45) are reported. The JARE-45 consisted of 62 members including 22 members of the summer party and 40 members of the wintering party. Besides, two wintering members and 6 summer members companied the expedition as observers. The Antarctic research vessel (icebreaker) Shirase" reached the pack ice edge near Lutzow-Holm Bay on 14th December 2003 and anchored at Syowa Station on 24th December. Including light oil transported by pipe, and freight transported by snow vehicles and by helicopter, a total of 1107.2 t of cargo was transported. Construction of facilities at Syowa Station was carried out. The construction of an INTELSAT antenna and shelter continued throughout the summer at Syowa Station. Summer research programs included atmospheric observations, geodesy at Syowa Station, and geological and biological field surveys in ice-free areas along the Soya Coast and the Prince Olav Coast. All of the summer party left Syowa Station on 15th February and headed to Sydney, east Australia. En route, oceanography, marine biological observations and marine geomagnetism were carried out on board. Members of the summer party of JARE-45 returned to Narita on 27th March 2004. Transport of personnel to Dome Fuji Station by airplane via the Russian Antarctic Station, Novolazarevskaya was performed for the first time