Audiogram measurement based on the auditory brainstem response for juvenile Japanese sand lance <Emphasis Type="Italic">Ammodytes personatus</Emphasis>

In this study, the auditory thresholds for juvenile Japanese sand lance Ammodytes personatus were measured based on its auditory brainstem response (ABR). The amplitude of the ABR waveforms to a sound stimulus were larger than that of the electric background noise caused by general brainwaves and myogenic signals after the averaging procedure. Japanese sand lance responded to low frequency sounds between 128 Hz and 512 Hz with a sound pressure level of 115–125 dB. As the test frequency decreased, so did the auditory threshold level, and the level was about 116 dB at 128 Hz and 181 Hz. These results indicate that Japanese sand lance can detect low frequency sound but are less sensitive than other fish species. These high thresholds are probably caused by the lack of a swim bladder.     

Population structure of Valsa ceratosperma, causal fungus of Valsa canker, in apple and pear orchards

On the basis of mycelial compatibility, the population structure of Valsa ceratosperma, the causal fungus of Valsa canker on broadleaf trees, was investigated in apple and pear orchards in Japan. Field strains of V. ceratosperma from a single canker on trunks or scaffold limbs belonged to different mycelial compatibility groups. Thus, the population structure of this fungus was complex in most orchards. Because mycelia of strains originating from different conidia from the same pycnidium were compatible, infection by this fungus is thought to be ascospores.     

Relationship between light and diel vertical migration of <Emphasis Type="Italic">Diaphus theta</Emphasis> and <Emphasis Type="Italic">Euphausia pacifica</Emphasis> off eastern Hokkaido

Underwater irradiance in sound-scattering layers (SSLs) during diel vertical migration (DVM) of marine organisms was investigated by a drifting vessel at locations in the western North Pacific during the period August 24–27, 2008. The inhabitants of the layers were identified via sampling as Diaphus theta, a type of myctophid fish, and Euphausia pacifica, a species of zooplankton. Underwater irradiance was estimated by the Beer–Lambert law using irradiance measurements on the deck and the diffuse attenuation coefficients obtained in the water. During DVM, the mean irradiances at 490 nm at the lower and upper boundaries of the SSL composed of E. pacifica were ?54.0 and ?45.3 dB, respectively. In contrast, the values for the boundaries of the D. theta SSL were ?82.5 and ?59.3 dB, respectively. It was possible to distinguish between D. theta and E. pacifica based on these ranges and the differences between the mean volume-backscattering strength (ΔMVBS) at 120 and 38 kHz. It was also possible to distinguish between D. theta/E. pacifica and other causes of scattering more clearly using these two parameters together than when using the ΔMVBS parameters separately. Our results suggest that underwater irradiance is an important parameter for discriminating among organisms in DVM.     

Effect of cooled and chlorinated chiller water on Campylobacter and coliform counts on broiler carcasses during chilling at a middle-size poultry processing plant

To evaluate the effect of cooled and chlorinated chill water for Campylobacter and coliforms at a middle-size processing plant which was considered to be difficult for eliminate pathogenic bacteria on carcasses, following three conditions were examined; keeping temperature at < 20, < 10 and < 10°C, and chlorine concentration at < 50, < 50 and 50 to 70 ppm during processing in experiment 1, 2 and 3 respectively. Fifteen prechill and 15 postchill carcasses were examined in each experiment. In lower temperature of experiment 2, decreasing rate (%) of coliforms was significantly higher (P<0.01) than that in experiment 1. In higher chlorination of experiment 3, no Campylobacter was detected from all postchill carcasses.     

Detection of tumorigenic Agrobacterium strains from infected apple saplings by colony PCR with improved PCR primers

With the colony polymerase chain reaction (PCR), the specificity of newly prepared primer sets VCF2/VCR2, VCF3/VCR3, VCF4/VCR4, and VCF5/VCR5 to Ti or Ri plasmids in Agrobacterium strains were compared to that of the conventional set VCF/VCR. At first, control strains, which consisted of a nonpathogenic strain and phytopathogenic strains carrying Ti or Ri plasmid, were used. VCF3/VCR3 and VCF5/VCR5 were highly specific to all the phytopathogenic strains, whereas the others were not. These two primer sets were superior to VCF/VCR in their specificity with colony PCR to tumorigenic Agrobacterium strains isolated from apple saplings.     

Characterization of tetraploid plants regenerated via protoplast culture of Iris fulva and their crossability with Japanese irises

Characteristics such as flower form, size and color of outer and inner perianths, anthocyanins in outer perianths, size, color and fertility of pollen and self-fertility of diploid and tetraploid lines regenerated via protoplast culture of Iris fulva were examined and compared with those of the diploid wild line. Among these characteristics, flower form, inner and outer perianth sizes of the tetraploid lines were noticeable, because these lines had upward flower forms and bigger flowers than diploid lines. Furthermore, reciprocal crosses between diploid or tetraploid lines of I. fulva and I. ensata and those of I. fulva and I. laevigata were performed. Three seedlings were obtained from the cross of tetraploid I. fulva × diploid I. laevigata through embryo rescue. One of them was identified as the interspecific hybrid between tetraploid I. fulva and I. laevigata by flow cytometoric (FCM), cytological and molecular (RAPD) analyses. This is the first report on production of hybrids from these lines. I. fulva has unique brown flowers, and this trait could be very useful for flower color breeding of I. laevigata which lacks this color. Therefore, the hybrid of I. fulva (4×) × I. laevigata may be the best available gene source for brown color breeding of this species.     

Incidence of viruses in <Emphasis Type="Italic">Alstroemeria</Emphasis> plants cultivated in Japan and characterization of <Emphasis Type="Italic">Broad bean wilt virus-2, Cucumber mosaic virus</Emphasis> and <Emphasis Type="Italic">Youcai mosaic virus</Emphasis>

Alstroemeria plants were surveyed for viruses in Japan from 2002 to 2004. Seventy-two Alstroemeria plants were collected from Aichi, Nagano, and Hokkaido prefectures and 54.2% were infected with some species of virus. The predominant virus was Alstroemeria mosaic virus, followed by Tomato spotted wilt virus, Youcai mosaic virus (YoMV), Cucumber mosaic virus (CMV), Alstroemeria virus X and Broad bean wilt virus-2 (BBWV-2). On the basis of nucleotide sequence of the coat protein genes, all four CMV isolates belong to subgroup IA. CMV isolates induced mosaic and/or necrosis on Alstroemeria. YoMV and BBWV-2 were newly identified by traits such as host range, particle morphology, and nucleotide sequence as viruses infecting Alstroemeria. A BBWV-2 isolate also induced mosaic symptoms on Alstroemeria seedlings.     

The four-line model of the Triangular Running Skyline system: Theory and numerical examples

The generalized static solution of the Triangular Running Skyline (TRS) system has been derived. A pair of tail spars with a haulback line enables the carriage of the TRS system to move around over the triangular area formed by connecting the bases of the three spars with each other,i.e., the two tail spars and one head spar. From the head spar, the main and slack-pulling lines stretch toward the carriage to move up and down the load. The theory derived in this paper separately evaluates the line lengths and line tensions of the main and slack-pulling lines (the four-line model), while the previous theory treats these two lines as a single equivalent line (the three-line model). Four numerical examples provided in this paper ascertained the accuracy of the two procedures of the four-line model. A part of this paper was orally presented at the Second Annual Meeting of the Japanese Forest Engineering Association, November 18, 1995, Tokyo. This English title is a tentative translation form the original Japanese by the authors of this paper.