Strength properties and effect of moisture content on the bending and compressive strength parallel to the grain of sugi (Cryptomeria japonica) round timber

Static bending tests and compressive test parallel to the grain of sugi (Japanese cedar, Cryptomeria japonica) green round timber were conducted to confirm whether its strength would satisfy the referenced strength determined by the Construction Ministry. The strength of green round timber and air-dried round timber were compared for bending and compression parallel to the grain. The strength change ratio in response to a 1 % change in the moisture content of round timber was compared with that of small clear specimens and timber. The results revealed that a 5 % parametric tolerance limit of bending and compressive strength parallel to the grain satisfied the referenced strength, even when using green round timber. The average strength of air-dried round timber was higher than that of green round timber, in both bending and compression parallel to the grain, with significant differences indicated at a 5 % significance level. The relation between the cross-section area that includes round timber, timber and the small clear specimens, and the strength change ratio in response to a 1 % change in moisture content change was fitted to a logarithm curve. Thus, the size of the specimen was considered to affect the strength change ratio.     

Changes in mitochondrial fatty acid composition following temperature acclimation of carp and their possible effects on FoF1-ATPase activity

Carp undergo temperature acclimation of respiratory function by altering mitochondrial ATP synthase (F_oF₁-ATPase) both quantitatively and qualitatively (Itoi et al. 2003). To address such acclimation temperature-dependent changes of F_oF₁-ATPase activity, we investigated in this study the correlation between the fatty acid composition and F_oF₁-ATPase activity in fast muscle of thermally acclimated carp. The quantities of saturated fatty acids of mitochondria from carp acclimated to 10 °C were significantly lower than those of carp acclimated to 30 °C. While mono- and poly-unsaturated fatty acids tended to increase with cold acclimation of carp, the molar concentration of 16:0 aldehyde in mitochondria from the 10 °C-acclimated carp were less than those from the 30 °C-acclimated fish. The specific activities of F_oF₁-ATPase in the 10 °C- and 30 °C-acclimated fish mitochondria were calculated to be 167±22 and 56±10 nmol/min ⋅ mg mitochondrial protein, respectively, the difference being significant at P<0.005. Taken together, the increase in F_oF₁-ATPase activity in fast muscle mitochondria of carp after cold temperature acclimation may be closely related to the increase of unsaturated fatty acids in mitochondria. Abbreviations: BSA - bovine serum albumin; DHA - docosahexaenoic acid; EGTA - ethyleneglycol bis(2-aminoethylether)tetraacetic acid; EPA - eicosapentaenoic acid; F_oF₁-ATPase - mitochondrial ATP synthase; α-F₁-ATPase - F_oF₁-ATPase α-subunit; β-F₁-ATPase - F_oF₁-ATPase β-subunit; HEPES - 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid; SDS - sodium dodecyl sulfate; SDS-PAGE - SDS-polyacrylamide gel electrophoresis. This revised version was published online in July 2006 with corrections to the Cover Date.     

Traditional seed production in landraces of daikon (Raphanus sativus) in Kyushu, Japan

Landraces of daikon, Japanese radish, Raphanus sativus var. hortensis, are grown and used traditionally in Kyushu, Japan. These landraces are maintained by seeds harvested from selected plants which are transplanted as dormant tap roots or are retained in a portion of field. Seeds kept in intact siliquas on the stems are harvested and stored until use, by hanging the dried stems. Although the relatively small number of plants used in a patch for seed production might be expected to result in a narrow base of genetic diversity of a farmers' lot in a landrace, addition of a few plants with contrasting features, pollen exchange between household patches, and contamination from other cultivars and feral forms may save the landraces from the rapid loss of diversity and deterioration caused by inbreeding depression. The seed production by transplanting described in medieval Japanese literature is relatively similar to the current practice. The factors responsible for maintenance of the landrace together with the cultural and climatic diversity of Japan may have contributed to a high diversity of landraces of the daikon. This revised version was published online in July 2006 with corrections to the Cover Date.     

Translation of continuous artificial selection on phenotype into genotype during rice breeding programs

Understanding genetic diversity among local populations is a primary goal of modern crop breeding programs. Here, we demonstrated the genetic relationships of rice varieties in Hokkaido, Japan, one of the northern limits of rice cultivation around the world. Furthermore, artificial selection during rice breeding programs has been characterized using genome sequences. We utilized 8,565 single nucleotide polymorphisms and insertion/deletion markers distributed across the genome in genotype-by-sequencing for genetic diversity analyses. Phylogenetics, genetic population structure, and principal component analysis showed that a total of 110 varieties were classified into four distinct clusters according to different populations geographically and historically. Furthermore, the genome sequences of 19 rice varieties along with historic representations in Hokkaido, nucleotide diversity and F_ST values in each cluster revealed that artificial selection of elite phenotypes focused on chromosomal regions. These results clearly demonstrated the history of the selections on agronomic traits as genome sequences among current rice varieties from Hokkaido.     

Pathogenicity of highly pathogenic avian influenza viruses of H5N1 subtype isolated in Thailand for different poultry species

Highly pathogenic avian influenza (HPAI) viruses of the H5N1 subtype have caused several rounds of outbreaks in Thailand. In this study, we used 3 HPAI viruses isolated in Thailand in January 2004 from chicken, quail, and duck for genetic and pathogenetic studies. Sequence analysis of the entire genomes of these isolates revealed that they were genetically similar to each other. Chickens, quails, domestic ducks, and cross-bred ducks were inoculated with these isolates to evaluate their pathogenicity to different host species. A/chicken/Yamaguchi/7/04 (H5N1), an HPAI virus isolated in Japan, was also used in the chicken and quail studies for comparison. All four isolates were shown to be highly pathogenic to chickens and quails, with 100% mortality by 10(6) EID50 inoculants of the viruses. They caused sudden death in chickens and quails within 2-4 days after inoculation. The mean death times (MDT) of quails infected with the Thai isolates were shorter than those of chickens infected with the same isolates. Mortality against domestic and cross-bred ducks ranged from 50 to 75% by intranasal inoculation with the 10(6) EID50 viruses. Neurological symptoms were observed in most of the inoculated domestic ducks and appeared less severe in the cross-bred ducks. The MDTs of the ducks infected with the Thai isolates were 4.8-6 days post-inoculation. Most of the surviving ducks infected with the Thai isolates had sero-converted until 14 dpi. Our study illustrated the pathobiology of the Thai isolates against different poultry species and would provide useful information for improving control strategies against HPAI.     

The structure of vocalization of ewes and male lambs at pasture

We performed an analysis of the vocalization of 161 ewes and 50 male lambs that were pastured day and night. The vocalization structures of the phonetic notations of the opened-mouth from closed mouth /ηaee/ and /ηnaeee/ and closed-mouth /ηηηη/ of ewes, and the opened-mouth from closed-mouth /ηeee/ and /ηneeee/ and closed-mouth /ηηηη/ of male lambs were studied in terms of their audio characteristics. The items subject to analysis included duration of each vocalization, fundamental frequency, sound pressure and first formant (F1), second formant (F2), and third formant (F3). Among the male lambs, the duration of each call type showed significant differences depending on the behavior types or the target types, and the closed-mouth to open-mouth sounds, /ηeee/ and /ηneeee/ showed a tendency to be longer than the closed-mouth sound of /ηηηη/. A significant correlation ( r  = 0.9, P  < 0.05) was observed between the fundamental frequency and F1 with the /ηeee/ type of call of the male lambs when the vocalization was targeted toward the stockperson. When the ewes' behavior pattern was grazing and moving and the calling target was an ewe, the sound pressure significantly differed between /ηηηη/ and /ηnaeee/ ( P  < 0.05). From the analysis of the call durations, the fundamental frequencies, the sound pressures and formants, and the particular characteristics in sound structure were shown to vary according to the vocalization conditions and the situations, and where the animals were placed, even within the same call types.     

Optimization of the supplemental essential amino acids to a fish meal-free diet based on fermented soybean meal for rainbow trout <Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>

To minimize the supplemental essential amino acids (EAAs) to a fish meal-free diet for rainbow trout Oncorhynchus mykiss, four types of fish meal-free diets and a control fish meal-based diet were fed to triplicate groups of trout (initial BW, 16 g) for 10 weeks. Two fish meal-free diets based on a fermented and an unfermented soybean meal were unsupplemented with EAAs (diet FSBM and SBM), and two fish meal-free diets based on the fermented soybean meal were supplemented with a combination of lysine and methionine (diet F + ML) and all EAAs (diet F + All), the EAA contents of which were lower than those of the control diet (diet FM). Although physiological conditions such as the biliary bile acid status and morphological features of fish fed diet FSBM were improved and similar to those of fish fed diet FM, the growth performance was not significantly different (P > 0.05) from fish fed diet SBM. The growth performances and whole body protein contents of fish fed F + ML and F + All diets were similarly improved compared to fish fed diet FSBM. These findings indicate that supplementation of lysine and methionine to a fermented soybean meal-based fish meal-free diet is enough to maximize the amino acid utilization of the diet.     

Decreasing dietary lipids improves larval survival and growth of Japanese eel Anguilla japonica

Shark eggs-based diet is the only diet by which eel larvae can grow to glass eels in captivity. However, the high level of lipids in the diet is suggested to negatively affect eel larvae. This paper examines the effect of defatted shark eggs (DSE) and hen egg yolk (HY) on growth and survival of larvae of Japanese eel Anguilla japonica. Lyophilized shark egg and commercial HY were defatted with n-hexane, and four experimental diets were prepared using both defatted and untreated shark eggs and HY. Larvae were reared for 3 weeks by feeding the experimental diets. The highest survival rate was observed in the larvae fed DSE, and larvae fed HY showed the lowest survival rate. The best growth was found in larvae fed DSE, followed by shark eggs and defatted HY, and the worst growth was in HY-fed larvae. These results show that decreasing dietary lipids improves the nutritional value of both shark eggs and HY for eel larvae. Regulation of the dietary lipid level may positively affect the larval performance of eels by combination of ingredients with a low lipid content.     

Nutritional evaluation of live food organisms and commercial dry feeds used for seed production of amberjack Seriola dumerili

To improve the nutritional quality of live foods and dry feeds ordinarily used for the seed production of amberjack Seriola dumerili, the nutrient contents of rotifers, Artemia nauplii and commercial feeds used in two larval production stations were evaluated. For comparison of the nutrient contents, artificially produced larvae, wild-caught juveniles and wild zooplankton samples were also analyzed. The proportions of 22∶6n-3 in the polar lipid of the cultured larvae increased by feeding the dry feeds. The taurine contents of the cultured larvae reflected the contents of their foods (rotifers<dry feed<Artemia nauplii). The taurine content and the proportion of 22∶6n-3 in Acartia spp. were higher than in foods fed to the larvae. These parameters in the wild juveniles were higher than the cultured ones. The A/E ratios [(each essential amino acid/total essential amino acids)×1000] of the total amino acids of the live foods and dry feeds were similar to those of the cultured larvae, except for the lower ratios of histidine, arginine, threonine and lysine in the live foods. The mucosal folds of the intestine of the cultured larvae did not show typical signs of dietary phospholipid deficiency. These results suggest that requirements of nutrients such as 22∶6n-3 and taurine should be determined for mass production of amberjack seeds.