Relationship between <Superscript>137</Superscript>Cs concentration and potassium content in stem wood of Japanese cedar (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>)

To utilize forest resources in areas affected by fallout from the Fukushima Daiichi Nuclear Power Plant accident, it is important to understand the mechanisms of ¹³⁷Cs movement through the stem wood of contaminated trees. Understanding the mechanism of absorption and migration of ¹³⁷Cs to stem wood is necessary for clues to the future prediction of the transition of ¹³⁷Cs to xylem. In the present study, radial variations in ¹³⁷Cs concentration were investigated in Japanese cedar (Cryptomeria japonica D. Don) trees collected 1 year and 10 months after the accident. Additionally, the relationship between ¹³⁷Cs concentration and potassium (K) content was established. Trees with a higher moisture content and lower lightness value in heartwood tended to have a higher ¹³⁷Cs concentration in the heartwood. In these trees, ¹³⁷Cs concentration peaked at the heartwood–sapwood boundary and gradually decreased toward the pith. By contrast, K content within the heartwood remained nearly constant along the radial direction. The heartwood-to-sapwood ratio of ¹³⁷Cs concentration was significantly positively correlated with that of K content. Based on these results, we suggest that ¹³⁷Cs movement from sapwood to heartwood might be related to the K content ratio of heartwood and sapwood.     

Radial and between-family variations of the microfibril angle and the relationships with bending properties in Picea jezoensis families

With emphasis on tree breeding for wood quality in Picea jezoensis, we aimed to evaluate radial and between-family variations in the microfibril angle (MFA) of the S₂ layer in the latewood tracheids in 10 open-pollinated families of 43-year-old P. jezoensis trees. In addition, the relationships between MFA/wood density with the modulus of elasticity (MOE) or modulus of rupture (MOR) were investigated. Significant differences in MFA between families were found from the pith toward the bark. MFA showed higher values around the pith area, although some families showed relatively lower values than others around this area. In addition, due to a larger coefficient of variations of MFA near the pith, the potential for juvenile wood MFA improvement may be greater compared with mature wood. MOE was correlated with MFA in juvenile wood and with wood density in mature wood, whereas MOR was mainly correlated with wood density at radial positions in both woods. Therefore, to improve the MOE and MOR of P. jezoensis wood, both MFA and wood density would be factors to consider in both juvenile and mature woods. On the other hand, there are indications that, only wood density would be an important criterion for improving mature wood properties.     

Molecular identification of `Candidatus Mycoplasma haemovis' in sheep with hemolytic anemia

We examined the presence of hemoplasmas, hemotropic mycoplasmas, among 11 sheep (Ovis aries) with regenerative and hemolytic anemia and found six of them were positive by real-time PCR. The positive samples were then subjected to conventional PCR for direct sequencing of the 16S rRNA gene. Nucleotide sequences of all the positive samples were identified as the 16S rRNA gene of `Candidatus Mycoplasma haemovis' by phylogenetic analysis, demonstrating the infections with this particular hemoplasma species in Japan.     

A Recessive Lesion Mimic Mutant of Rice with Elevated Resistance to Fungal Pathogens

A gamma-ray-induced rice mutant, M1009, which spontaneously forms brown specks on leaves was isolated. In appearance, these lesions very much resemble those that are produced during the hypersensitive resistance response of rice to pathogens. A similar phenotype has been associated with a number of mutants in maize or Arabidopsis, which have been briefly categorized as disease lesion mimics. Brown speck formation was suppressed at temperatures of 25°C and above, and was severe at 20°C. Light irradiation is also required to initiate brown specks. In addition, the mutant exhibits heightened resistance to two major fungal pathogens of rice, Magnaporthe grisea and Cochliobolus miyabeanus. Genetic characterization of the mutant has indicated that its les-bs (lesion-brown speck) phenotype segregates as a monogenic recessive mutation. Received 13 September 1999/ Accepted in revised form 15 December 1999     

Outbreak of neonatal canine herpesvirus infection in a specific pathogen-free beagle colony

Nine out of 19 newborn pups from 4 litters died or euthanatized on day 10 to 17 after birth in a specific-pathogen-free beagle colony which had been established by cesarean section and bottle-feeding. Necropsy showed congestion and edema of the lungs, congestion of the liver and splenomegaly, as well as many subcapsular petechiae and wedge-shaped areas of ecchymosis on the cut surface of the kidneys. A cytopathic agent isolated from the lungs, kidneys and liver was identified as a canine herpesvirus. The bitches in the animal house were seroconverted into positive for the isolate after the outbreak of the disease. Histopathological lesions in six cases were characterized by multiple necrosis and hemorrhage in various organs. In addition, fibrinoid necrosis was seen in the arterial walls in wedge-shaped necrotic areas of the kidneys. The outbreak appeared to be temporary, since the same disease has not occurred in the colony up to the present time.     

Effects of direct exposure to cold weather under grazing in winter on the physiological,immunological, and behavioral conditions of Japanese Black beef cattle in central Japan

This study aimed to reveal the effects of direct exposure to cold weather under grazing in winter (GW) on the health of Japanese Black beef cattle, as assessed using physiological, immunological, and behavioral parameters. Ten Japanese Black beef cattle (328 ± 45 kg, 7.6 ± 3.4 years of age) were used in this experiment. In winter, five of the 10 cattle grazed for 2 months in a 1.8 ha pasture (GW), and the remaining cattle were fed under confined conditions with tethering (control [CT]). The two groups were fed similar feed during the experiment, except for the grazing forage. Blood samples were collected approximately every 2 weeks. The numbers of neutrophils and monocytes and antioxidant enzyme activity were higher in the GW group than in the CT group (p < 0.05). The proportions of CD4‐single‐positive cells were lower in GW cattle than in CT cattle (p = 0.06). This study showed that direct exposure of beef cattle to cold weather under GW enhanced the levels of circulating neutrophils and monocytes and contributed to the kinetic homeostasis of lymphocytes but also activated antioxidant enzymes due to an increase in oxidative stress.     

Genetic and antigenic characterization of bovine viral diarrhea viruses isolated from cattle in Hokkaido,Japan

In our previous study, we genetically analyzed bovine viral diarrhea viruses (BVDVs) isolated from 2000 to 2006 in Japan and reported that subgenotype 1b viruses were predominant. In the present study, 766 BVDVs isolated from 2006 to 2014 in Hokkaido, Japan, were genetically analyzed to understand recent epidemics. Phylogenetic analysis based on nucleotide sequences of the 5′-untranslated region of viral genome revealed that 766 isolates were classified as genotype 1 (BVDV-1; 544 isolates) and genotype 2 (BVDV-2; 222). BVDV-1 isolates were further divided into BVDV-1a (93), 1b (371) and 1c (80) subgenotypes, and all BVDV-2 isolates were grouped into BVDV-2a subgenotype (222). Further comparative analysis was performed with BVDV-1a, 1b and 2a viruses isolated from 2001 to 2014. Phylogenetic analysis based on nucleotide sequences of the viral glycoprotein E2 gene, a major target of neutralizing antibodies, revealed that BVDV-1a, 1b and 2a isolates were further classified into several clusters. Cross-neutralization tests showed that BVDV-1b isolates were antigenically different from BVDV-1a isolates, and almost BVDV-1a, 1b and 2a isolates were antigenically similar among each subgenotype and each E2 cluster. Taken together, BVDV-1b viruses are still predominant, and BVDV-2a viruses have increased recently in Hokkaido, Japan. Field isolates of BVDV-1a, 1b and 2a show genetic diversity on the E2 gene with antigenic conservation among each subgenotype during the last 14 years.     

Software development for estimating the concentration of radioactive cesium in the skeletal muscles of cattle from blood samples

The 2011 earthquake severely damaged the Fukushima Daiichi Nuclear Power Plant (FNPP), resulting in the release of large quantities of radioactive material into the environment. The deposition of these radionuclides in rice straw as livestock feed led to the circulation of contaminated beef in the market. Based on the safety concern of the consumers, a reliable method for estimating concentrations of radioactive cesium in muscle tissue is needed. In this study, we analyzed the concentrations of radioactive cesium in the blood and skeletal muscle of 88 cattle, and detected a linear correlation between them. We then developed software that can be used to estimate radioactive cesium concentrations in muscle tissue from blood samples. Distribution of this software to the livestock production field would allow us to easily identify high‐risk cattle, which would be beyond the safety regulation, before shipping out to the market. This software is planned to be released as freeware. This software would contribute to food safety, and aid the recovery of the livestock industry from the damage creacted by the 2011 Tohoku earthquake and tsunami.     

The cumulative methane production from dairy cattle slurry can be explained by its volatile solid,temperature and length of storage

In order to refine the national estimate of methane emission from stored cattle slurry, it is important to comprehend the basic characteristics of methane production. Two dairy cattle slurries were obtained from livestock farms located in Hokkaido (a northern island) and Kyushu (a southern island). The slurries were diluted with water into three levels: undiluted, three times diluted, and 10 times diluted. Three hundred mL of the slurries were put into a bottle with a headspace volume of 2.0 L, which was filled with nitrogen gas and then sealed by butyl rubber. Four levels of temperature were used for incubation: 35, 25, 15 and 5 °C. The time course of the cumulative methane production per volatile solid (VS) was satisfactorily expressed by an asymptotic regression model. The effect of dilution on the methane production per VS was not distinctive, but that of temperature was of primary importance. In particular, higher temperature yields a higher potential production and a shorter time when the cumulative production reaches half of the potential production. The inclusive and simple models obtained in this study indicate that the cumulative methane production from stored cattle slurry can be explained by VS, temperature and length of storage.