Ⅰ. Impact assessment of oil pollution

金沢大学大学院自然科学研究科　環境科学Editor : Tazaki, Kazue |田崎, 和

Strong ice-ocean interaction beneath Shirase Glacier Tongue in East Antarctica

Mass loss from the Antarctic ice sheet, Earth’s largest freshwater reservoir, results directly in global sea-level rise and Southern Ocean freshening. Observational and modeling studies have demonstrated that ice shelf basal melting, resulting from the inflow of warm water onto the Antarctic continental shelf, plays a key role in the ice sheet’s mass balance. In recent decades, warm ocean-cryosphere interaction in the Amundsen and Bellingshausen seas has received a great deal of attention. However, except for Totten Ice Shelf, East Antarctic ice shelves typically have cold ice cavities with low basal melt rates. Here we present direct observational evidence of high basal melt rates (7–16 m yr−1) beneath an East Antarctic ice shelf, Shirase Glacier Tongue, driven by southward-flowing warm water guided by a deep continuous trough extending to the continental slope. The strength of the alongshore wind controls the thickness of the inflowing warm water layer and the rate of basal melting

〔研究ノート〕腸内細菌叢検索における試料保存方法がDNA解析に与える影響の評価

　　Recently, studies of intestinal microbiota have been conducted using mainly next-generation sequencers to perform comprehensive bacterial DNA analyses. When using this molecular biological approach, intestinal bacterial DNA is extracted from fecal samples. But the influence of the fecal sample storage condition and the methods of DNA extraction on the analysis have not been investigated as far as we know. In this study, we evaluate the effects of different freezing conditions and storage periods of microbial DNA in fecal samples using PCR-DGGE analysis. Fecal samples were stored at −20 ºC, −80 ºC and −80 ºC followed by a liquid nitrogen treatment and kept for 3 months and 1 year, respectively. 　　Microbial DNA extracted from these fecal samples was examined using PCR-DGGE analysis to monitor total intestinal microbiota: Bacteroides, Bifidobacterium, Lactobacillus and Clostridium groups. DGGE profiles demonstrated that the total bacterial flora was stable and no significant changes were found due to storage conditions or periods. In genus specific detection of samples stored for three months, DNA bands were detected in all samples except for in part of the Clostridium group. In the case of fecal samples stored for one year, both at −80 ºC and also treated with liquid nitrogen, amplified genus specific bands were present in all samples. A different band pattern was observed only in the amplicon of the liquid nitrogen treated samples from the Clostridium group. On the other hand, in microbial DNA extracted from samples preserved at −20 ºC it was impossible to amplify specific fragments. Since some bacterial groups in fecal samples were affected by the freezing method, storage conditions and period, it appears that rapidly freezing fecal samples may be the most effective way to maintain intestinal microbiota

Posttraumatic Cranial Cystic Fibrous Dysplasia

A 14-year-old was girl admitted to our hospital with a subcutaneous mass of the occipital head. The mass had grown for 6 years, after she had sustained a head injury at the age of 6, and was located directly under a previous wound. Skull X-ray Photograph (xp), computed tomography (CT), and magnetic resonance imaging (MRI) showed a bony defect and cystic changes in the skull corresponding to a subcutaneous mass. Bone scintigraphy revealed partial accumulation. The patient underwent total removal of the skull mass, and the diagnosis from the pathological findings of the cyst wall was fibrous dysplasia (FD). The radiographic findings for cystic cranial FD can be various. Progressive skull disease has been reported to be associated with head trauma, but the relationship between cranial FD and head trauma has not been previously reported. Previous studies have suggested that c-fos gene expression is a key mechanism in injury-induced FD