Modified method for evaluating weathering intensity using outdoor exposure tests on wood-based panels

The deterioration of wood-based panels at eight sites in Japan over 7?years of outdoor exposure was investigated. In particular, the modulus of rupture (MOR) retention and internal bond strength (IB) retention after 7?years of exposure were compared among panels and sites. The deterioration of panels was greater in southern Japan than in northern Japan. The strength retentions in northern Japan decrease linearly, while those in southern Japan decreased exponentially. To quantify regional differences, deterioration rates were calculated based on three different weather conditions (precipitation, temperature, and sunlight hours), and the significance of each of these parameters on panel deterioration was determined. We found that the correlation coefficients between both IB and MOR retention and weathering intensity were the same whether we used 10-day, monthly, or daily weathering data.     

Mechanism of acid-neutralization in two Japanese watersheds

In Japan, acidification of terrestrial water has not yet been reported except lakes acidified by volcano or mine. However, acid deposition in Japan is as much as those in northern Europe and north-eastern U.S.A., and acidification of terrestrial water may occur in future. In order to predict long-term acidification, it is necessary to understand acid-neutralization mechanism in watershed. Therefore, two experimental watersheds study for geology, hydrology, and water chemistry were conducted. On the basis of these data, chemical change in percolation of precipitation through watersheds and acid-neutralization mechanism are analyzed. The principal results are: (1) Acid deposition is neutralized continuously in percolation of precipitation from ground-surface to aquifer, (2) Chemical weathering of primary minerals plays an important role in the acidneutralization in the watersheds, and should be quantified and taken into account in the long-term prediction of acidification.     

A long‐term study of the effects of SLC12A1 homozygous mutation (g.62382825G>A,p.Pro372Leu) in Japanese Black cattle

Recessive missense mutation in the solute carrier family 12, member 1 (SLC12A1) gene (g.62382825G>A) is associated with hydrallantois, which is the accumulation of fluid in the allantoic cavity of a pregnant animal, and usually causes fetal death in Japanese Black cattle. However, the symptoms of a homozygote with this mutation that do not result in fetal death have not previously been tracked and evaluated. In the present study, we observed a homozygote with the SLC12A1 risk allele over a long‐term period. The calf did not show any obvious clinical symptoms, although it did exhibit a slight growth retardation that accompanied mild calciuria. At 28 months of age, the homozygote showed renal dysfunction, which in turn resulted in hydronephrosis. The time course of the symptoms was consistent with the phenotype of Bartter syndrome in humans. Additionally, the risk heterozygous genotype did not any effects on carcass traits, which indicates that eliminating the risk allele would not have any unfavorable effects. Therefore, we emphasize that both the fetal‐ and late‐stage symptoms associated with the SLC12A1 risk allele compromise animal welfare, and consequently may result in severe economic losses for individual farmers if the SLC12A1 risk allele is not eliminated from the population.     

Histopathologic features of the skin of hairless newborn pigs with goiter.

The skin of 15 hairless newborn pigs with parenchymatous goiter was studied histopathologically. Most of the lesions were in the hair follicles; follicles were scarce and reduced in size, contained slender hairs, and revealed a shortage of penetration into the hypodermis. Hair follicles in the immature stages, hair pegs, and germs also were recognized, with the thin epidermis lacking in keratinization. It was felt that these changes resulted from a retardation of cellular differentiation of the germinal layer. In view of these findings, skin lesions were regarded as hypoplasia of hair.     

Discovering the dominance of the non-native European eel in the upper reaches of the Tone River system,Japan

To investigate the presence of non-native anguillid eels in Japanese waters, 141 eels were collected from seven sampling sites throughout the Tone River system. Genetic species identification showed an extraordinary dominance of the non-native European eel Anguilla anguilla in the uppermost site of the study area. Estimation of age from otoliths suggested that the European eels were introduced into the river in the 1990s, corresponding to previous reports from other Japanese water systems. Comparison of the von Bertalanffy growth curve parameters indicated that the European eels caught in the Tone River system appeared to have a similar or even higher growth rate than the same species in the original habitats in Europe. The long-term inhabitation and the normal development of European eels in Japanese waters suggest that regulations prohibiting the release of non-native eels and safeguards against accidental escape from culture ponds must be strictly maintained in order to ensure the conservation of the native Japanese eel.