A model to estimate available timber and forest biomass and reforestation expenses in a mountainous region in Japan

We developed a model to estimate supply potentials and available amounts of timber and forest biomass resources from profitable sub-compartments of thinning and final felling operations. Economic balances were estimated while considering not only harvesting expenses but also reforestation expenses after final felling, which should be considered for sustainable forest management. Harvesting expenses were estimated based on two types of timber harvesting systems and three types of forest biomass harvesting systems in each sub-compartment. Then, the model was applied to Nasushiobara city of Tochigi prefecture, Japan. Reforestation expenses had large negative impacts on the financial balances of final felling operations. Few sub-compartments were profitable after considering reforestation expenses. Most profitable sub-compartments were those with mechanized operation systems and landing sales. These accounted for 17.19% of all sub-compartments, while only 5.75% of the sub-compartments were profitable based on their current operation systems and landing sales. Although the overall supply potentials of timber and forest biomass resources were 380,000 m3 and 210,000 Mg, respectively, and 15 times the planned harvest of coniferous tree volume of 25,000 m3year-1 and 50 times the annual demand for the woody gasification power generation of 4,000 Mg year-1 in Nasushiobara, available amounts of timber and forest biomass resources were only49,429 m3 and 33,333 Mg, which were 13.0% and 15.7% of supply potentials for landing sales with mechanized operation systems.     

Two Amino Acid Substitutions in the Coat Protein of Pepper mild mottle virus Are Responsible for Overcoming the L(4) Gene-Mediated Resistance in Capsicum spp

ABSTRACT The Capsicum spp. L genes (L(1) to L(4)) confer resistance to tobamoviruses. Currently, the L(4) gene from Capsicum chacoense is the most effective resistance gene and has been used widely in breeding programs in Japan which have developed new resistant cultivars against Pepper mild mottle virus (PMMoV). However, in 2004, mild mosaic symptoms began appearing on the leaves of commercial pepper plants in the field which possessed the L(4) resistance gene. Serological and biological assays on Capsicum spp. identified the causal virus strain as a previously unreported pathotype, P(1,2,3,4). PMMoV sequence analysis of the virus and site-directed mutagenesis using a PMMoV-J of the P(1,2) pathotype revealed that two amino acid substitutions in the coat protein, Gln to Arg at position 46 and Gly to Lys at position 85, were responsible for overcoming the L(4) resistance gene.     

A comparative study of monoterpenoids and phenylpropanoids from essential oils against stored grain insects: acute toxins or feeding deterrents

The relationship between the acute toxicity and feeding deterrent activity of ten compounds occurring commonly in essential oils was explored in order to determine whether they are acute toxins or antifeedants against stored-grain pests. Simultaneously, the objective was also to demonstrate the comparative efficacy against three post-harvest stored-grain pests. Thymol, carvacrol, eugenol and trans-anethole were specifically toxic, and linalool was a generalist feeding deterrent against all three species studied. Thymol was most toxic to Tribolium castaneum and Rhyzopertha dominica compared to carvacrol and eugenol but was least toxic to Sitophilus oryzae. Similarly, linalool deterred feeding of S. oryzae (FI₅₀ = 0.025 mg/g of the wafer diet), T. castaneum (FI₅₀ = 0.207 mg/g of the wafer diet) and R. dominica (FI₅₀ = 0.482 mg/g of the wafer diet) at different concentrations; R. dominica beetles required about 20 times the concentration to deter feeding compared to S. oryzae and more than twice compared to T. castaneum. Comparison of toxicity and deterrent activity with respective artificial blends as binary mixtures revealed that synergism was not a generalized phenomenon, and the variations were both species as well as blend specific. Individual compound efficacy correlations were not ascertained, which suggests that artificial blends could be prepared to obtain potential mixtures for substantial control of stored-grain insect pests. The present study also implies that the compounds are mostly acute toxins, and whatever inhibition in feeding was obtained could be due to physiological toxicity rather than any interaction with gustatory receptors.     

Comparisons of ribosomal DNA-internal transcribed spacer sequences and biological features among <Emphasis Type="Italic">Olpidium bornovanus</Emphasis> isolates from Cucurbitaceae-cultivating soil in Japan

The chytrid fungus Olpidium bornovanus is an obligate plant parasite that acts as a vector to transmit Melon necrotic spot virus in cultivated soil. Here, we conducted a molecular phylogenetic analysis of 16 isolates of O. bornovanus taken from soil in which Cucurbitaceae plants had been grown in various locations throughout Japan. The ribosomal DNA and internal transcribed spacer region sequences of the 16 O. bornovanus isolates were divided into four molecular phylogenetic groups, designated O.bor-A to O.bor-D. Biological features of O. bornovanus isolates such as host specificity varied consistently with their molecular phylogenetic groups.     

Role of sulphide reduction by magnesium hydroxide on the sediment of the eutrophic closed bay

This study was focused on the effect of magnesium hydroxide (Mg(OH)₂) for improving the sediment of aquaculture field and eutrophic closed estuaries. Sediment samples were collected from Omura Bay, Nagasaki, Japan. The change in pH, acid volatile sulphides (AVS) and dissolved organic carbon (DOC) in interstitial water of the sediment samples were measured before and after 20‐day incubation under the condition of overlapping seawater at 25°C with 0.3–0.4 mg/L of dissolved oxygen (DO). Hydrogen sulphide (H₂S) and the dsrA gene copy number of Grp3 sulphate‐reducing bacteria (SRB) in the sediment samples were also measured at 7‐day incubation under the same condition. The pH of Mg(OH)₂ treatment group was significantly increased from 7.43 to 8.25; it was higher compared to the control group which pH was maintained around 7.6. Meanwhile, the AVS content of Mg(OH)₂ treatment group was significantly reduced and the value was lower than the control group after the 20‐day incubation. Each concentration of interstitial water DOC in the treatment group and the control group increased after the incubation from initial value of 15.4–40.1 and 29.0  mg/L respectively. Furthermore, simultaneous decrease in H₂S and the dsrA gene copy number of Grp3 SRB was observed at the end of the 7‐day incubation by adding Mg(OH)₂. It is concluded that the loss of activity of SRB was strongly related to the decrease in sulphide (H₂S and AVS) and the increase in DOC was due to the alkalization of the sediment by adding Mg(OH)₂.     

An evaluation of radiographic hepatic size in dogs with portosystemic shunt

Radiographically, the hepatic sizes of portosystemic shunt (PSS) cases were evaluated. In this study the hepatic area was compared in PSS and non-PSS dogs by utilizing the right lateral radiography. The top three breeds of PSS dogs of Maltese, Shih Tzu and Yorkshire Terrier, were included and these dogs had a significantly smaller hepatic area ratio of 46.37 +/- 0.63%, 61.76 +/- 0.78% and 41.59 +/- 0.23% respectively (p<0.05) and the average overall hepatic area in the 3 dog breeds was 47.75 +/- 0.40%.     

Infestivity of Demodex canis to hamster skin engrafted onto SCID mice

We demonstrated that Demodex canis was transferred to skin xenografts of a dog and a hamster onto severe combined immunodeficiency mice. After the transfer of mites, the number of eggs, larvae, nymphs and adult mites per gram of canine and hamster xenografts increased, whereas no live mites were detected on murine allograft. These results indicate that D. canis proliferates in hair follicles of dog and hamster skins but not in murine allograft. Therefore, D. canis may have host preference but not strict host-specificity.     

Differentiation of Erysipelothrix rhusiopathiae strains by nucleotide sequence analysis of a hypervariable region in the spaA gene: discrimination of a live vaccine strain from field isolates.

Erysipelothrix rhusiopathiae causes erysipelas in swine and is considered a reemerging disease contributing substantially to economic losses in the swine industry. Since an attenuated live vaccine was commercialized in 1974 in Japan, outbreaks of acute septicemia or subacute urticaria of erysipelas have decreased dramatically. In contrast, a chronic form of erysipelas found during meat inspections in slaughterhouses has been increasing. In this study, a new strain-typing method was developed based on nucleotide sequencing of a hypervariable region in the surface protective antigen (spaA) gene for discrimination of the live vaccine strain from field isolates. Sixteen strains isolated from arthritic lesions found in slaughtered pigs were segregated into 4 major patterns: 1) identical nucleotide sequence with the vaccine strain: 3 isolates; 2) 1 nucleotide substitution (C to A) at position 555: 5 isolates; 3) 1 nucleotide substitution at various positions: 5 isolates; and 4) 2 nucleotide substitutions: 3 isolates. Isolates with the same nucleotide sequence as the vaccine strain were further characterized by other properties, including the mouse pathogenicity test. One strain isolated from pigs on a farm where the live vaccine had been used was found to be closely related to the vaccine strain. The phylogenetic tree constructed based on the spaA sequence suggests that the evolutionary distance of the isolates is related to the pathogenicity in mice. The new strain-typing system based on nucleotide sequencing of the spaA region is useful to discriminate the vaccine strain from field isolates.     

Effects of medetomidine and midazolam alone or in combination on the metabolic and neurohormonal responses in healthy cats

The purpose of this study was to investigate the effects of a medetomidine-midazolam combination on some neurohormonal and metabolic variables in healthy cats. Five cats were used repeatedly in each of 5 groups, which were injected intramuscularly with physiological saline solution (control), 0.5 mg/kg of midazolam, 40 microg/kg of medetomidine, 80 microg/kg of medetomidine, and 40 microg/kg of medetomidine plus 0.5 mg/kg of midazolam. Blood samples were taken 10 times over 24 h from a catheter introduced into the jugular vein. Plasma concentrations of glucose, insulin, glucagon, cortisol, nonesterified fatty acids (NEFAs), norepinephrine, and epinephrine were determined. In addition, the duration of lateral recumbency, rectal temperature, heart rate, and respiratory rate were examined. The combination of medetomidine and midazolam enhanced the duration of lateral recumbency and reduced the hyperglycemia induced by medetomidine alone. Recovery from hypoinsulinemia induced by the medetomidine-midazolam combination tended to be more rapid than when the same dose of medetomidine was used alone. The decrease in plasma norepinephrine levels induced by medetomidine alone was diminished by the addition of midazolam. Midazolam alone did not significantly change the plasma glucose, insulin, glucagon, cortisol, epinephrine, or NEFA concentration, but increased the norepinephrine concentration. This study revealed that the combination of medetomidine and midazolam produces minimal neurohormonal and metabolic changes when compared with medetomidine alone in cats.