Regional variability in landscape effects on forest bird communities

Landscape Ecology - Functional responses to landscape heterogeneity are context-dependent, hampering the transferability of landscape-scale conservation initiatives. Japan provides a unique...     

The changes in proximate compositions and glycogen contents in the dorsal ordinary muscles of the full-cycle cultured Pacific bluefin tuna Thunnus orientalis occurring with growth

ABSTRACT:   Using full-cycle cultured (FC) Pacific bluefin tuna (body length [BL], 42.6–66.4 cm; body weight [BW], 1.66–7.40 kg, n  = 15), the changes in chemical compositions and histological structure of the cephalal parts of the dorsal ordinary muscles (DOM) occurring with growth were investigated. A positive correlation ( r  = 0.9644, P  < 0.05) was observed between BL and BW with growth. The protein, lipid and ash contents of DOM and condition factor did not change with growth. However, the glycogen content of DOM increased ( P  < 0.05) from approximately 55 cm (BL) in this study. Using optical microscopic photographs, the various shapes of muscle fibers were observed and it was noted that the muscle fiber diameter increased ( P  < 0.05) with growth. Using transmission electron microscopic observation, many glycogen granules were observed in muscle fibers (especially, side of connective tissue) of DOM throughout the growth stage in this study. These results indicate that the glycogen content of DOM of FC Pacific bluefin tuna increases before the lipid with growth.     

Development of X-ray computed tomography for live standing cattle

An X‐ray computed tomography (CT) system for live standing cattle was developed for studying the meat yield, carcass composition and so on. The gantry contained three X‐ray tubes and detectors that corresponded to each X‐ray tube. The system was able to operate while the animal remained standing. The scan area had a diameter of 900 mm. The Musculus longissimus and Musculus trapezius areas, and the back fat thickness in the CT image were evaluated and compared to the actual cross‐section of the carcass using eight cattle. The differences among the muscles, and the subcutaneous and intermuscular fat were easily recognized. The correlation coefficient between the CT image and the actual carcass photograph of the M. longissimus area and the back fat thickness was high (r = 0.84, r = 0.93, P < 0.01). The present study demonstrated that muscle, fat and bone can be clearly imaged from a live standing animal using X‐ray equipment.     

Concentrations and specific antibodies to staphylococcal enterotoxin-C and toxic shock syndrome toxin-1 in bovine mammary gland secretions,and inflammatory response to the intramammary inoculation of these toxins

To investigate the pathological role of staphylococcal enterotoxins (SEs) and toxic shock syndrome toxin-1 (TSST-1) in bovine mastitis, the production of SEs and TSST-1 was investigated in staphylococci isolated from 120 mammary gland secretions (MGS, 51 from no clinical sign-mammary glands and 69 from staphylococcal mastitic-mammary glands) collected from dairy farms where staphylococcal mastitis frequently occurred in Miyagi and Yamagata prefectures from 1997 to 1998. Concentrations of these toxins and specific antibody titers in each MGS were also measured. Furthermore, SEC and TSST-1 were inoculated into lactating mammary glands and inflammatory responses were analyzed. A high percentage of staphylococci including Staphylococcus aureus and coagulase-negative staphylococci isolated from both no clinical sign- and mastitic-MGS produced both SEC and/or TSST-1. The concentration of SEC increased with the severity of the mastitis, and was significantly higher (P<0.05) in acute mastitic-than in no clinical signs-MGS. Titers of specific antibodies to TSST-1 in MGS were significantly higher (P<0.05) than those to SEC, regardless of whether or not the cows were lactating or mastitic. Specific antibodies purified from MGS neutralized each toxin in vitro. A significant increase (P < 0.05) in somatic cell counts was induced by the intramammary inoculation of SEC but not TSST-1. These findings indicated that SEC rather than TSST-1 plays an important role in the pathology of staphylococcal bovine mastitis. The inflammatory activity of TSST-1 was probably neutralized by specific antibodies in MGS.     

Pathogenicity of Rhodococcus equi expressing a virulence-associated 20 kDa protein (VapB) in foals

Rhodococcus equi strains of intermediate virulence (IMV) for mice possess a 20kDa protein designated Virulence Associated Protein B (VapB) and a virulence plasmid of 79-100kb, and can be recovered from the submaxillary lymph nodes of pigs. The pathogenicity of such R. equi strains for foals is unknown. In this study, two foals, 42 and 43 days of age, were infected intratracheally with 10(6) and 10(9) cells of R. equi IMV strain A5, respectively. The foal infected with 10(9) cells of strain A5 became clinically ill, with the onset of illness (pyrexia and depression) occurring 21 days after inoculation. R. equi was isolated from the feces and tracheal washings of the foal from 14 to 28 days after inoculation. The foal infected with 10(6) cells of A5 showed no clinical signs, and no R. equi was isolated from any of the samples of feces or tracheal washings during the 28 days of observation. Two foals of 45 and 50 days of age were infected with 10(5) or 10(6) of virulent R. equi ATCC 33701 having 15-17kDa surface proteins designated VapA. Both exhibited severe clinical signs (pyrexia, depression and anorexia) at 12 and 13 days after inoculation. Histopathological examination revealed that strain A5 caused focal granulomatous pneumonia in the foals. R. equi IMV strain A5 was isolated from lung lesions of both foals and from the contents of the intestinal tracts of the foal infected with 10(9) bacteria. These results suggest that IMV R. equi having VapB is less virulent than virulent R. equi having VapA in foals. This finding supports our previous results on the pathogenicities of R. equi strains having these virulence-associated antigens assessed by mouse pathogenicity tests.     

Optimal application timing of simeconazole granules for control of rice kernel smut and false smut

We investigated the optimal timing of simeconazole (RS-2-(4-fluorophenyl)-1-(1H-1,2,4-triazol-1-yl)-3-trimethylsilylpropan-2-ol) application for controlling rice kernel smut in field trials in Miyagi Prefecture, Japan, using formulations of simeconazole (1.5% granules). The field tests revealed that a submerged application of simeconazole granules (450–600 g ai/ha) at 1–5 weeks before heading was highly effective against kernel smut, with treatments 1–2 weeks before heading being the most effective. Submerged application of the fungicide at 2–5 weeks before heading was also highly effective against false smut, with treatment 3 weeks before heading being the most effective. These periods overlap the timing for optimal application of simeconazole to control rice sheath blight and ear blight. Consequently, we concluded that treatment with simeconazole 2–3 weeks before heading can be a useful tool for controlling all four diseases.     

Lesion-based analysis of leaf blast suppression in mixture of rice cultivar and a resistant near-isogenic line

Leaf blast suppression in multilines was evaluated based on the number of susceptible lesions observed in a pure stand of susceptible rice cultivar Sasanishiki, and in 1 : 1 and 1 : 3 mixtures of Sasanishiki and a resistant near-isogenic line, Sasanishiki BL4 or BL7, from 1998 to 2001. The number of lesions first observed in fields in the 1 : 1 and 1 : 3 mixtures were close to theoretical numbers calculated using the number of lesions observed in the pure stands and the ratios of the susceptible Sasanishiki in the mixtures. The ratio of the number of lesions in the 1 : 1 and 1 : 3 mixtures to the number in the pure stand was 0.29 and 0.09, respectively. The relationship between these ratios and the ratios of susceptible Sasanishiki in mixtures was defined in an equation to estimate the degree of leaf blast suppression. Validation studies for the ratios of the number of lesions in the 1 : 1 and 1 : 3 mixtures to the number in the pure stand were conducted in two different locations and showed that the ratios are almost acceptable. The calculated autoinfection to alloinfection ratio was 1.3 and 1.4 in the 1 : 1 and 1 : 3 mixtures, respectively, suggesting that the calculated ratio will affect the degree of leaf blast suppression. Thus, predictors were obtained to estimate leaf blast suppression for effective blast control in multilines.     

Isolation and characterization of lectins from the AG-D group of binucleate <Emphasis Type="Italic">Rhizoctonia</Emphasis> species

Isolates from 18 anastomosis groups (AGs) of binucleate Rhizoctonia were screened for lectin activity. Eight AGs (AG-B, AG-D, AG-F, AG-G, AG-H, AG-I, AG-R and AG-U) had low to moderate lectin activities. Among these, members of AG-D and AG-I had the highest activity. Partially purified lectins from AG-D preferentially agglutinated human blood type A to type B and O. Mucin and galactose were the most potent inhibitors among the tested carbohydrates. The molecular masses of these lectins ranged from 12.7 kDa for the monomer to 62 kDa for the pentamer type. Proline, alanine, glutamic acid, aspartic acid, leucine, threonine, serine and tyrosine were the major amino acid components of these lectins. Lectins from AG-D were stable at 4–50°C and from pH 6.0 to 10.0. When assayed with isoelectric focusing, these lectins gave bands at pI 9.30. Specificity of lectins from AG-D to galactose and its derivatives suggest a possible recognition role in this fungal species.