Abstract The larval mesopelagic fish assemblage and its distribution patterns were investigated in the Kuroshio region off southern Japan in late winter. A total of 8690 fish larvae was collected, 85.8% of which were mesopelagic fish larvae. Mesopelagic fish larvae were significantly more abundant in the area east of the Kuroshio axis than west of the Kuroshio axis (660.6 versus 194.5 ind 10 m −2 ). Sigmops gracile , Bathylagus ochotensis , Notoscopelus japonicus , Diaphus slender type and Myctophum asperum were the five most abundant larvae and accounted for 16.9, 16.4, 15.2, 13.9 and 9.3% of the total catch in numbers, respectively. We conclude that these larvae were transported by the Kuroshio Current to the more productive transition waters, where they spend their juvenile stage from spring to early summer. The possibility of expatriation and southward long‐distance spawning migrations of N. japonicus and B. ochotensis are discussed, based on the geographic distribution patterns of their larvae, juveniles and adults.
A case of spontaneous perforation of the hypopharynx accompanied by acute mediastinitis is reported. An 8-year-old male was admitted to our hospital for sudden dyspnea. On admission, he had a low grade fever, subcutaneous emphysema, and pneumomediastinum. The next day, C-reactive protein values were markedlyelevated. Radiographic findings showed dilatation of the right upper mediastinum and leakage of contrast material from the right piriform sinus or just below it. As no underlying disease was present and his history was unremarkable, neither chest trauma nor a foreign body was considered likely. Spontaneous perforation was suspected. Hypopharyngeal or esophageal perforation should be considerd in a patient presenting with pneumomediastinum and findings of severe inflammation. Early diagnosis and treatment of acute mediastinitis are essential for lifesaving.
The first case of anaplastic carcinoma arising in median ectopic thyroid (thyroglossal duct remnants) in an 84-year-old woman is presented. This expands the spectrum of histologic types of thyroid malignancies reported in this location and supports the theory that these carcinomas arise from thyroid rests associated with thyroglossal ducts. The presence of a histologically benign follicular neoplasm adjacent to the carcinoma suggests the possibility that the anaplastic carcinoma resulted from the transformation of an underlying well-differentiated tumor. Some unusual features of this case are discussed as well as the criteria for establishing the diagnosis of carcinoma arising in a thyroglossal duct remnant.
The array of vectors for the winnowing wind in the threshing unit was investigated using PIV in order to improve the winnowing accuracy.It is difficult to measure wlnd velocities at many points simultaneously using the anemometer.However, visualization of the winnowing wind was possible using thc tracer and laser beam.Furthermore, the PIV method made it possible to measure an array of vectors for the winnowlng wlnd.The results produced by PIV concurred with the results of conventional method.The wlnd map obtained in this method is expected to provide essential data for understanding of the characteristics of trajectories of grain and chaff.
