A taxonomic study of Macrochloris multinucleata (Chlorophyceae) isolated from soils in the vicinity of Syowa Station.

第2回極域科学シンポジウム/第33回極域生物シンポジウム 11月18日（金） 統計数理研究所 3階リフレッシュフロ

Diatoms composing benthic microbial mats in freshwater lakes of Skarvsnes ice-free area, East Antarctica

Diatoms composing benthic microbial mats in Skarvsnes lakes, East Antarctica, were studied in terms of their taxonomy and relationship to environmental factors. Samples were collected from 13 freshwater lakes in the area. Amphora sp. (cf. veneta) was dominant in 11 of the 13 samples, while Craticula sp. (cf. molesta) and Diadesmis sp. (cf. perpusilla) were respectively dominant in the remaining 2 samples. Navicula ectoris Van de Vijver was also reported here for the first time in continental Antarctica. Mosses in the microbial mats did not have a significant effect on the diatom species composition. Redundancy analysis revealed that the main environmental gradient for diatoms was electric conductivity, despite its relatively narrow range (18-390 mS m^(-1)). Our results suggest that Diadesmis sp. and Psammothidium metakryophilum are halophobes, whereas Amphora sp. is a halophile

Feasibility studies on future phycological research in polar regions

Cyanobacteria and algal communities are essential in the process of initial primary succession following landscape deglaciation. Near the glacial front, a shallow wetland zone is maintained by melting ice. Here, algal mats and crusts quickly develop. The ground in all of these wet habitats is cold due to the close presence of the glacial front and permafrost. Cyanobacteria and algal populations which survive and expand in such extreme cold and unstable environments display special ecological and physiological acclimatization-adaptation characteristics, which enable them to succeed during the initial colonization phase. In this text, it is proposed to use these young microbial ecosystems as feasibility studies for developing the necessary methodology to assess the algal response to climate change. Cyanobacteria and algal communities are the most appropriate model microorganisms for such study because of their global universality, environmental sensitivity, fast reproductive potential and relatively easy experimental manipulation. We propose the microbial studies on three different mutually complementary levels : ・Study of diversity, structure and life strategies of Cyanobacteria and algae participating in the initiation of primary succession. ・Study of primary production, nitrogen fixation and nutrient utilization in natural and nutritionally-manipulated experimental set-ups. ・Study of physiological response of Cyanobacteria and algae to temperature change. The processes of primary succession have been widely studied by Japanese, as well as Czech, scientists in polar regions during recent times. In this paper, we review phycological studies which have been carried out in the Antarctic and the Arctic, and sounded on feasibility studies in this field

Distribution of soil algae at the monitoring sites in the vicinity of Syowa Station between austral summers of 1992/1993 and 1997/1998

Distribution of soil algae was studied in the vicinity of Syowa Station in Lutzow-Holm Bay, Antarctica between the austral summers of 1992/1993 (JARE-33) and 1997/1998 (JARE-38) from the viewpoint of environmental monitoring. Soils were collected from 10 monitoring sites. Sites 1-4 were within Syowa Station. Sites 1-3 were close to a urinal tank. Six sites (sites 5-10) were several km from the station. Site 10 was in a penguin rookery. Twenty-one soil algae were identified : eight of Cyanophyceae, eight of Chlorophyceae, three of Xanthophyceae and two of Bacillariophyceae. Leptolyngbya cf. battersii, Phormidium autumnale, Navicula muticopsis, Xanthonema spp., Botrydiopsis spp. and Macrochloris multinucleata were common. An ornithocoprophilous alga, Prasiola crispa, was found in cultures of soils from sites 1-3 and at site 10. Total carbon contents (TC), total nitrogen (TN) and total phosphorus (TP) in soils ranged from 0.04 to 0.991%, 0.002-0.401% and 0.161-0.809%, respectively. Maximum TC, TN and TP were observed at site 10. Relatively high values of TC (0.301%) and TN (0.016%) were detected at site 2. Presence of P. crispa at sites 1-3 and higher values of TC and TN at site 2 indicated that eutrophication of surface soils occurred near the urinal tank. The results of cluster analysis showed that most soil algal assemblages at sites 1-3 were grouped together. No clear changes in soil algal communities were observed during the study period at any of the monitoring sites

Distribution of aquatic mosses in the Soya Coast region, East Antarctica

The distribution of aquatic mosses among 73 lakes in the Soya Coast region, East Antarctica, was surveyed. Two species of mosses, Bryum pseudotriquetrum and Leptobryum sp. were found at the bottom of lakes. B. pseudotriquetrum was found in 38 lakes (52.1%), mainly in freshwater lakes throughout the study area. Leptobryum sp. was found in 26 lakes (35.6%) in a rather restricted area, and mainly in relatively saline lakes

Management of Multiple Primary Lung Cancer in Patients with Centrally Located Early Cancer Lesions

BackgroundPatients with centrally located early lung cancer (CLELC) are often heavy smokers with a considerably high risk of multiple primary lung cancer (MPLC) lesions; treatment strategies for such patients must preserve the cardiopulmonary function.MethodsBetween July 2004 and July 2008, patients with CLELC underwent photodynamic therapy (PDT) using NPe6, second-generation photosensitizer at Tokyo Medical University Hospital. Among these patients, we retrospectively analyzed MPLC, which was treated by surgery plus PDT or PDT alone and examined the effectiveness of PDT, and we propose a treatment strategy for patients with MPLC.ResultsA total of 64 patients with CLECL received NPe6-PDT, and MPLCs were found in 22 patients (34.4%) using sputum cytology and a bronchoscopical examination using autofluorescence bronchoscopy. Among these 22 patients, 10 patients underwent surgery for primary lung cancer and underwent NPe6-PDT for the treatment of secondary primary CLELC, one patient underwent PDT for CLELC as a primary lesion followed by an operation for peripheral-type lung cancer as a secondary primary lesion, and 11 patients underwent PDT alone for MPLC lesions (28 lesions) that were roentgenographically occult lung cancers. Among these 22 patients with MPLC including peripheral-type lung cancers, which were resected by surgery, all 39 CLELC lesions exhibited a complete response after PDT, and all patients were alive.ConclusionsFor patients with lung cancer with a long-term history of smoking, careful follow-up examinations after surgical resection are needed considering the incidence of metachronous primary lung cancers. PDT can play an important role for the treatment strategy for MPLC

ナンキョク コショウ ニオケル セイタイ チシガクテキ ケンキュウ ケイカク (REGAL Project) コレマデ ノ ケイカ ト コンゴ ノ ケイカク

第36次から42次観測隊にかけて,南極湖沼における生態・地史学的研究計画(Research on Ecology and Geohistory of Antarctic Lakes: REGAL Project)の第一期計画(REGAL-I)が実施された.本研究計画は,南極科学委員会(SCAR)のもとで進められているRiSCCに対応したものであり,南極湖沼生態系の構造と変遷史の解明を目的としている.昭和基地周辺の数多くの多様な湖沼を観測対象とし,湖水の物理・化学的性質や生物相の多様性,堆積物からの古環境の復元などを行った.As part of the RiSCC (Regional Sensitivity to Climate Change in Antarctic Terrestrial and Limnetic Ecosystems) program sponsored by the Scientific Committee on Antarctic Research (SCAR), the REGAL (Research on Ecology and Geohistory on Antarctic Lakes) project has been conducted around the Syowa Station area. The first period of the program (REGAL-I) was promoted from 1994/1995 to 2000/2001, aiming to understand the structure and history of the Antarctic lake ecosystem. The progress of REGAL-I is summarized preparatory to drawing up the plan of REGAL-II from 2003/2004 to 2004/2005