A time-series data analysis to examine effects of subsidies to fishery productions in Japan

A cointegration analysis is conducted to examine the effect of fishery subsidies on fisheries production using data compiled over more than 30 years in Japan. The results illustrate that one fishery production indicator (production value per fishermen) shows a positive relationship with one particular group of government financial transfer (GFT) (that is, government general service expenditures including cost for fishery managements, scientific researches, and other administrative activities). No other tested results between GFTs and fishery indicators showed a real relationship. Although further scrutiny is awaited, this study could provide an empirical basis for an argument that, under an effective fishing management system, fisheries subsidies do not necessarily cause production increases or negative impact on fishing stocks.     

基于声学摄像仪的溯河洄游幼香鱼计数

至今主要靠目视计数来掌握香鱼(Plecoglossus altivelis)的资源量,这种方法很耗劳动力且精度低.由华盛顿大学研发的声学摄像仪DIDSON(Dual-frequency IDentification SONar)可在浑浊不清的水中摄取接近光学视频画质的图像.其附带软件虽可对体长为几十厘米的大个体鱼计数,但对于体长6 cm以下的小个体鱼,由于其回波信号弱,计数显得非常困难.本文提供了一种基于DIDSON的溯河洄游幼香鱼计数的新方法.首先从声学图像中消除静止的背景,提取出运动目标并除去噪音像素,然后用卡尔曼滤波器对剩下的目标进行跟踪,根据目标移动的特性把目标分为香鱼和垃圾2大类,在除去向下游移动的垃圾之后,可正确地计算向上游移动香鱼的数量.通过现场实测验证了上述声学计数方法的实用性和高效性.     

Origin and nature of halloysite in Ando soils from Towada tephra,Japan

The origin and nature of halloysite in Ando soils from Towada tephra were investigated. These soils were formed from five tephras: Towada-a (1,000 years old), Towada-b (2,000 years old), Chuseri (4,000 years old), Nanbu (8,600 years old) and Ninokura (10,000 years old).Formation of halloysite took place only in the buried soils from Nanbu and Ninokura tephras occurring in an “accumulating zone”, where thicknesses of overburden tephra deposits were mostly 2.5 m or greater and silica enrichment of the clay fractions could occur.The amounts of halloysite were greater in (1) the soils from Ninokura tephra than in those from Nanbu tephra, and greater in (2) the humus horizons as compared to the nonhumus horizons of these same soils. The mean sizes of spheroidal halloysite particles and the ratios of numbers of tubular to spheroidal forms differed with differences in soil horizons and age.High-resolution electron micrographs of glycerol-solvated spheroidal halloysite particles had lattice images of 11 Å due to (001) from the exterior to the interior and had no indications of layer separation. Moreover, the central core of spheroidal halloysite with a diameter of 150 Å showed neither layer structure nor allophane spherules.Results obtained in this study thus indicate that spheroidal and tubular forms of halloysite were formed concurrently in these Ando soils.     

Multiplex PCR and Genescan analysis to detect immunoglobulin heavy chain gene rearrangement in feline B-cell neoplasms

Lymphoid neoplasms are usually diagnosed on the basis of cytological and histopathological findings. However, in some cases, discrimination of lymphoid neoplasms from reactive lymphoid proliferation is difficult. PCR amplification of complementarity-determining region 3 (CDR3) of the immunoglobulin heavy-chain variable region (IGHV) gene can be used to assess clonality of B-cell populations as a supportive diagnostic tool for B-cell neoplasms. Because of the sequence variation and possible somatic hypermutation of the IGHV gene, sensitivity of the PCR-based assay to detect clonal IGHV gene rearrangement largely depends on the sequences and numbers of primer sets. Prior to the development of an efficient assay, we cloned and sequenced 97 IGHV complementary DNAs (48 IGHV-1 and 49 IGHV-3 clones) from normal cat spleens. On the basis of these sequences, we designed 6 forward primers at the variable region and 5 reverse primers at the joining region. Using each of 6 forward primers and a mixture of 5 reverse primers, we amplified CDR3 of IGHV genes and analyzed the PCR products by conventional PAGE and Genescan analyses using fluorescence-labeled primers. Twenty-six feline B-cell neoplasms diagnosed by histopathological and immunohistochemical examinations were subjected to the newly developed analysis of IGHV gene rearrangement. Clonal IGHV gene rearrangement was detected in 22 of 26 (84%) samples by both PAGE and Genescan analyses. To reduce the number of PCR reactions, we constructed a multiplex PCR analysis system using a mixture of IGHV-1- and IGHV-3-specific primers as forward primers and a mixture of 5 joining region reverse primers. Results of the multiplex PCR were 100% concordant with those obtained by each of the singleplex PCRs. The multiplex PCR-based assay and Genescan analysis developed in the present study would be useful and practical tools to detect clonal IGHV gene rearrangement in feline B-cell neoplasms.     

Mycobacterium ulcerans infection in an Indian flap-shelled turtle (Lissemys punctata punctata)

We report an atypical mycobacterial infection in an Indian flap-shelled turtle, Lissemys punctata punctata, that died in an aquarium in Japan. At necropsy, the turtle showed multiple white nodules on the capsular surface and parenchyma of various organs such as the liver, spleen, intestine, and lung. Histologically, granulomatous inflammation surrounding a central zone of necrosis was observed. Sections stained by the Ziehl-Neelsen method revealed numerous acid-fast bacilli in the cytoplasm of macrophages and in the central area of necrosis. The organisms were identified as a mycobacterial species by PCR and nucleotide sequence analysis and revealed 98-100% homology to M. ulcerans. This is, to our knowledge, the first report of mycobacteriosis due to M. ulcerans in a turtle.     

Sarcoptes scabiei var. canis refractory to ivermectin treatment in two dogs

A 10-year-old castrated male Shih Tzu presented with severe generalized pruritus. Skin scrapings revealed the presence of Sarcoptes scabiei var. canis. A Yorkshire terrier in the same household simultaneously developed pruritus due to scabies. Both dogs were treated with 300 μg/kg ivermectin, at first orally and then subcutaneously at 14 day intervals. However, live mites were still found on day 35, and the skin condition deteriorated in both dogs. These findings suggested that the S. scabiei in these dogs was clinically refractory to ivermectin. The pruritus in both dogs rapidly and completely disappeared following topical fipronil administration. This appears to be the first report of canine scabies refractory to ivermectin treatment.     

Ethanol Does Not Promote MeIQx-initiated Rat Colon Carcinogenesis Based on Evidence from Analysis of a Colon Cancer Surrogate Marker

Epidemiological studies suggest that alcohol consumption increases the risk of developing colorectal cancer. However, the data are confounded by numerous cosegregating variables. To cast further light on the relationships between alcohol intake and colon cancer development, 21-day-old male F344/DuCrj rats were fed 200 ppm 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) in their diet for 8 weeks and doses of 0, 0.1, 0.3, 1, 3, 10 and 20% of ethanol in their drinking water ad libitum for 16 weeks thereafter. The rats were sacrificed after 24 weeks of experiment, and aberrant crypt foci (ACF), surrogate lesions for colon cancer, were examined under a light microscope at low magnification. Ethanol was found not to affect the ACF formation at any dose compared with the initiated-controls. Furthermore, ethanol did not alter colon epithelial cell proliferation. These data, obtained by analysis of a colon cancer surrogate marker lesion, indicate that ethanol lacks promotion activity for MeIQx-initiated rat colon carcinogenesis.