Analysis of the Change in Dominant Phytoplankton Species in Unstratified Lake Oshima-Ohnuma Estimated by a Bottle Incubation Experiment

1996年5?7月に、渡島大沼において、優占植物プランクトンの細胞密度を測定し、さらにボトル培養実験によりそれらの成長速度を見積り、春から夏への植物プランクトン優占種変化に関わる要因を明らかにすることを試みた。4、5月にAsterionella gracillimaが優占種となったが、その成長速度は5月には比較的低く、その後、細胞密度が低下し、この主な原因は栄養塩の不足であることが示唆された。6月後半からMelosira gramulataの成長速度が増加し、優占種となった。M.gramulataは水深6mでも成長速度が高いことから、深層で生存できることと、湖が成層を形成しないことで再懸濁により有光層に存在できる状況が同種の成長に適していることが考えられた

Fundamental study on functionality of synthetic sulfides : Evaluation of metal sulfides as solid lubricant

Replacement of exhaustible and harmful resources used as solid lubricants is required for sliding elements such asplain bearings. In particular, the substitution of lead containing in the lead bronze is considered an urgent task. Therefore, in this study, attention was focused on metal sulfides (Cu2S, Cu5FeS4, SnS, TiS2, etc) as a substitute material for lead. After synthesis of sulfide and preparation of sintered body, friction and abrasion test was carried out and applicability as solid lubricant was investigated. The tribological properties of the dry conditions were evaluated by a journal type high speed tester. As a result, the friction coefficient of the bronze specimen without sulfide was about 0.3, whereas the bronze specimen containing sulfide showed a friction coefficient of about 0.1, indicating that the sulfide reducedthe frictional resistance. Among them, the specimens containing Cu2S and Cu5FeS4 exhibited a lower friction coefficient. It is considered that this is influenced not onlyby the effect of hardness but also by film formation by sulfide

A preliminary study of glacial geomorphology in area between Breid Bay and the Sør Rondane Mountains in Queen Maud Land, East Antarctica

During the period from 12 to 17 February 1983,a preliminary study of glacial geomorphology was carried out in the area between Breid Bay and the Sør Rondane Mountains by the 23rd and 24th Japanese Antarctic Research Expedition to implement earth science programs in the Sør Rondane Mountains. The obstruction by the Sør Rondane Mountains to the ice flow is the cause of the elevated ice surface in the south of the mountains, and also the cause of the extremely low level in the north of the mountains, probably aided by the shelter effect of the mountains. Outlines of the ice shelf front and the respective positions have indeed remained unchanged over twenty-three years, but the reentrant, a widely and deeply fractured zone, is formed in the ice shelf between the Base Roi Baudouin and the ice front. It was found that the reentrant was formed between 1967 and 1973,and further fracturing of the platform of this ice shelf may occur with the development of crevasses, and therefore the ice shelf may break off in not so far future. A rough estimate of the mass budget of the ice sheet in the area between Breid Bay and the Sør Rondane Mountains suggests that the ice sheet may keep the present shape owing to the high accumulation rate over the ice sheet surface at present. If the present accumulation rate decreases, the lowering of the ice sheet surface may occur and, therefore, the thinning of the ice sheet may cause the retreat of grounding line, since most of the base of the ice sheet lies well below see level. The detailed radio-echo sounding is essential for clarifying whether the ice sheet in this area is of a marine type or not. At least, it is grounding in the front of the ice shelf at present

Detection of bone metastases using diffusion weighted magnetic resonance imaging: comparison with 11C-methionine PET and bone scintigraphy

Purpose: We evaluated the ability of diffusion-weighted imaging (DWI) to detect bone metastasis by comparing the results obtained using this modality with those obtained using 11C-methionine (MET) positron emission tomography (PET) and bone scintigraphy.Materials and methods: This retrospective study involved 29 patients with bone metastasis. DWI was obtained using a single-shot echo planar imaging (EPI) sequence with fat suppression using a short inversion time inversion recovery sequence. The detection capabilities of DWI for bone metastases were compared with those of whole body MET PET (in 19 patients) and 99mTc-methylene diphosphonate bone scintigraphy (in 15 patients).Results: Among the 19 patients who were diagnosed using DWI and PET,the PET identified 39 bone metastases, while the DWI identified 60 metastases out of 69 metastases revealed with conventional magnetic resonance imaging (MRI).Among the 15 patients who were diagnosed using DWI and bone scintigraphy,the bone scintigraphy identified 18 bone metastases, while the DWI identified 72 metastases out of 78 metastases revealed with conventional MRI. The overall bone metastasis detection rates were 56.5% for PET, 23.1% for bone scintigraphy and 92.3% for DWI.Conclusion: DWI is a very sensitive method for detecting bone metastasis and is superior to MET PET and bone scintigraphy in terms of its detection capabilities

The Diagnostic Ability of Diffusion Weighted Imaging with Background Body Signal Suppression (DWIBS) in Bone Metastasis

Recently High resolution diffusion-weighted imaging with background body signal suppression(DWIBS) and 3D images offers significant improvement for whole body screening strategies for detecting malignancy. The authors present a report of performing DWIBS in 10 patients with different kinds of tumors and bone metastasis in order to assess its ability in detecting bone metastasis. DWIBS data were compared with 11C-methinine positron emission tomography(MET-PET) and whole body bone scan. We believe DWIBS is a very sensitive method for detecting bone metastasis especially in pelvic cavity which is superior to MET-PET and bone scan; although for providing specifity side-by-side comparison with conventional MRI is necessary.ISMRM 14th Scientific Meeting & Exhibitio

Characterization of Cervical Cancer Tumors befor/during Radiotherapy by using Oligonucleotide Microarray

日本放射線影響学会第４８回大

Analysis of the Change in Dominant Phytoplankton Species in Unstratified Lake Oshima-Ohnuma Estimated by a Bottle Incubation Experiment

1996年5?7月に、渡島大沼において、優占植物プランクトンの細胞密度を測定し、さらにボトル培養実験によりそれらの成長速度を見積り、春から夏への植物プランクトン優占種変化に関わる要因を明らかにすることを試みた。4、5月にAsterionella gracillimaが優占種となったが、その成長速度は5月には比較的低く、その後、細胞密度が低下し、この主な原因は栄養塩の不足であることが示唆された。6月後半からMelosira gramulataの成長速度が増加し、優占種となった。M.gramulataは水深6mでも成長速度が高いことから、深層で生存できることと、湖が成層を形成しないことで再懸濁により有光層に存在できる状況が同種の成長に適していることが考えられた