シラセ サイヒョウ コウコウ データ ガ シメス ナンキョク リュツォ・ホルムワン テイチャクヒョウ ノ ネンネン ヘンカ

南極リュツォ・ホルム湾において毎年ほぼ同時期,同海域を航海する砕氷船「しらせ」は,海氷モニタリング・プラットフォームに適している.同湾の海氷状況の年々変化を推測するために,1983年から2002年までの間の「しらせ」砕氷航行データを解析した.主にラミング砕氷と氷厚や積雪深との関係を調べ,ラミング一回当たりの進出距離を砕氷航行の難易度の指標とすることにより,定着氷域の変化の特徴を抽出した.ラミング時の進出距離が短い1990年代前・中期は,航海が困難で厳しい氷状を反映し,氷厚や積雪深が大きい.一方,1990年代終わりから2002年までの間は,進出距離が長い傾向にあり,湾内定着氷の崩壊・流出の頻発期とも符合していることがわかった.Characteristics of sea-ice conditions in Lutzow-Holmbukta, Antarctica, have been investigated using the ice navigation log from the icebreaker Shirase, which has made a voyage almost at the same season and in the same sailing route every year since 1983. The vessel is considered as a suitable monitoring platform for sea ice. Not only basic information such as ice thickness and snow depth, but also ramming icebreaking data have been analyzed. In particular, the penetrating distances by ramming reflect difficulty in ice navigation and show distinctly interannual variations from 1983 to 2002. The periods with longer distances are consistent with those when breakup of landfast ice occurred frequently in the bay. The penetrating distances have shown a tendency to increase since the end of the 1990s, when ice breakup has been pronounced

Successful Treatment of Gastrosplenic Fistula Arising from Diffuse Large B-Cell Lymphoma with Chemotherapy: Two Case Reports

Gastrosplenic fistula (GSF) is a rare condition arising from gastric or splenic lymphomas. Surgical resection is the most common treatment, as described in previous reports. We report two cases of GSF in diffuse large B-cell lymphoma (DLBCL) patients that were successfully treated with chemotherapy and irradiation without surgical resection. Case 1 was of a 63-year-old man who had primary gastric DLBCL with a large lesion outside the stomach wall, leading to a spontaneous fistula in the spleen. Case 2 was of a 59-year-old man who had primary splenic DLBCL, which proliferated and infiltrated directly into the stomach. In both cases, chemotherapy comprising rituximab + dose-adjusted EPOCH regimen (etoposide, prednisone, vincristine, cyclophosphamide and doxorubicin) was administered. Case 1 had significant bleeding from the lesion of the stomach during the treatment cycle; however, endoscopic hemostasis was achieved. Case 2 developed a fistula between the stomach and the spleen following therapeutic chemotherapy; however, no complications related to the fistula were observed thereafter. In both cases, irradiation was administered, and complete remission was achieved

センジョウ カンソク データ ニ モトヅク ナンキョク リュツォ・ホルムワン テイチャクヒョウ ノ カキ ニオケル ヒョウアツ オヨビ セキセツシン ブンプ トクセイ ニツイテ

南極観測船「しらせ」船上で取得された海氷観測結果をもとに,リュツォ・ホルム湾定着氷の夏季における氷厚及び積雪深分布について考察した.ビデオ観測結果から求めた各年の全氷厚(氷厚+積雪深)確率密度分布は薄氷型と厚氷型に分けられることがわかった.また大陸沿岸から約km圏内では全氷厚及び積雪深は沿岸に向かって漸減する傾向を示した.これは北東方向の卓越風による積雪輸送によると考えられる.電磁誘導法によって観測された全氷厚分布には不連続的な変化が認められた.NOAAAVHRR画像と比較した結果,不連続の位置は定着氷流出後の再結氷域における一年氷と,未流出の厚い多年氷との境界に一致することがわかった.定着氷の流出範囲は年によって大きく変動する.流出位置が沖側に後退すると厚い多年氷域の割合が多くなり厚氷型になり,沿岸に近づくと積雪影響も相まって厚い多年氷域が縮小または消滅し,薄氷型になるというメカニズムが明らかになった.Sea ice observations have been conducted onboard the Antarctic Research Vessel Shirase" since . The authors summarize these data to investigate spatial and inter-annual variability of sea ice thickness and snow depth of the summer land-fast ice in Lutzow-Holmbukta. Probability density functions of annual total thickness (ice thickness+snow depth) derived from video observations are categorized into two types, i.e. a thin-ice and a thick-ice type. The total thickness distributions observed by the electro-magnetic inductive method have a clear discontinuity, which reects the past break-up of the land-fast ice. Thin rst-year ice develops oshore of this location, while multi-year ice mostly develops onshore. Ice thickness and snow depth gradually decrease toward the coast within about km oshore, probably due to snow drift driven by the strong northeasterly wind. It is concluded that the past breakup of the land-fast ice as well as snow depth have dominant inuence on the spatial distribution of ice thickness in Lutzow-Holmbukta. The extent of break-up varies signicantly year by year. The smaller extent enhances the development of thick multi-year ice, while the larger extent, coupled with the inuence of snow drift, enhances reduction or extinction of thick multi-year ice

Accelerated decline of sea ice cover on the Northern Sea Route

第3回極域科学シンポジウム/特別セッション「これからの北極研究」11月28日（水） 国立極地研究所 2階大会議

Classification of Ice in Lutzow-Holm Bay, East Antarctica, Using Data from ASCAT and AMSR2

This paper presents an ice classification algorithm based on combined active and passive microwave radiometer data in Lutzow-Holm Bay (LHB), East Antarctica. The ice classification algorithm is developed based on the threshold values of an advanced scatterometer (ASCAT) and advanced microwave scanning radiometer 2 (here, AMSR2). These values are calculated via the features of various ice types, including open ice, first-year (FY) ice, multi-year (MY) ice, MY ice including icebergs (MY IB), ice shelves, coastal ice sheets, and inland ice sheets. To verify the validity of the ice classification algorithm, the algorithm results are compared with visual observation data and satellite imagery. Except for the flaw polynya and area with surface melting, the FY ice, MY ice, and the ice shelf areas estimated here using the proposed ice classification algorithm match those discernible from the verification data. Inter-annual changes in the areal extents of FY ice, MY ice, and the ice shelves are investigated here using the proposed ice classification algorithm. Investigation of MY ice and ice shelf areas revealed that the breakup of MY ice induced a breakup of an ice shelf. A comparison of the FY ice and MY ice areas showed the replacement of these ice types. The proposed ice classification algorithm can detect ice breakup events as quantitative changes in the distribution and ice type. In future work, we plan to classify sea ice in other sea ice areas, applying the proposed algorithm throughout the Antarctic region

Interannual variation of landfast ice condition in Lutzow-Holmbukta, Antarctica, derived from navigation log of icebreaker Shirase

Characteristics of sea-ice conditions in Lutzow-Holmbukta, Antarctica, have been investigated using the ice navigation log from the icebreaker Shirase, which has made a voyage almost at the same season and in the same sailing route every year since 1983. The vessel is considered as a suitable monitoring platform for sea ice. Not only basic information such as ice thickness and snow depth, but also ramming icebreaking data have been analyzed. In particular, the penetrating distances by ramming reflect difficulty in ice navigation and show distinctly interannual variations from 1983 to 2002. The periods with longer distances are consistent with those when breakup of landfast ice occurred frequently in the bay. The penetrating distances have shown a tendency to increase since the end of the 1990s, when ice breakup has been pronounced

Aleukemic leukemia cutis in a patient with Philadelphia chromosome-positive biphenotypic leukemia.

Aleukemic leukemia cutis is a rare condition characterized by the invasion of leukemic blasts into the skin before their appearance in the peripheral blood. Leukemia cutis usually occurs in patients with myeloid leukemia, especially the myelomonocytic and monocytic types of acute myeloblastic leukemia. We describe the case of a 62-year-old woman with aleukemic leukemia cutis who developed Philadelphia-positive acute leukemia 1 month after skin involvement. Leukemic cells expressed both myeloid and B-cell lineage surface markers, and monoclonal rearrangement of the immunoglobulin heavy chain was detected by Southern blot analysis. This report is the first of a case of aleukemic leukemia cutis preceding Philadelphia-positive biphenotypic leukemia

Acquired Hemophilia A Developing Cerebral Infarction 36 Days after the Frequent Administration of Bypass Hemostatic Agents

A 74-years-old male who was a smoker and received treatment for hypertension, dyslipidemia, peripheral arterial disease and idiopathic interstitial pneumonia complained of subcutaneous hemorrhage of the right lower thigh. Marked anemia (hemoglobin 5.5 g/dL) and prolonged activated partial thromboplastin time (≥130 s) were noted. The factor VIII activity level was reduced to 1.2%, and the factor VIII inhibitor titer was 285.3 BU/mL, a diagnosis of acquired hemophilia A (AHA) was made. Then, hematomas of 5 intra-muscles were recurred. Hemostasis became difficult despite frequent and high-dose administration of recombinant human coagulation factor VIIa (total: 18 days, 305 mg). Hemostasis was achieved by switching to activated prothrombin complex concentrate (for 3 days, 18,000 units), however, cerebral infarction occurred after 36 days. After the frequent administration of bypass hemostatic agents on elderly AHA patients with several risk factors for ischemic stroke, the risk of subsequent thrombotic events may persist for 1 month