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.     

Underwater sound detection by cephalopod statocyst

Abstract:   The cephalopod receptor of particle motion was identified. In a previous study, it was suggested that statocysts served this function, but there was no direct supporting evidence, and epidermal hair cells had not been conclusively ruled out. Experiments on Octopus ocellatus were conducted using respiratory activity as an indicator of sound perception. Intact animals clearly responded to 141-Hz particle motion at particle accelerations below 1.3 × 10⁻³ m/s², and the mean perception threshold at this frequency was approximately 6.0 × 10⁻⁴ m/s². Specimens in which the statoliths had been surgically removed did not show any response for accelerations up to 3.9 × 10⁻³ m/s² at 141 Hz, which was approximately 16 dB greater than the mean perception threshold at this frequency. Specimens that had undergone a control operation in which the statoliths remained intact showed positive responses at 2.8 × 10⁻³ m/s² for the same frequency stimulus. This indicates that the statocyst, which is morphologically similar to the inner ear system in fish, is responsible for the observed responses to particle motion in O. ocellatus . This is the first direct evidence that cephalopods detect kinetic sound components using statocysts.     

Influence of light intensity on feeding, growth, and early survival of leopard coral grouper (Plectropomus leopardus) larvae under mass-scale rearing conditions

This study investigated the effect of different light intensities on feeding, growth and survival of early stage leopard coral grouper Plectropomus leopardus larvae. Four different light intensities (0, 500, 1000 and 3000 lx) were used and larvae were kept under constant light conditions from 0 day after hatching (DAH) to 5 DAH. The larvae were fed a small S-type of Thai strain rotifers at a density of 20 individuals/mL from 2 DAH. The number of rotifers in larval digestive organ and total length of larvae were examined at 3 h intervals between 04:00 and 22:00 h on 3 DAH, and thereafter at 6 h intervals until the end of the experiment (5 DAH). Four experimental trials of the larval rearing were repeated using by 60 kL mass-scale rearing tanks. The results indicate that coral grouper larvae are visual feeders and their food intake increases with increasing light intensity. Food intake of larvae reared at 3000 lx was significantly higher than those reared at 0–1000 lx on 3 DAH despite being the first-feeding day (P < 0.01). On 4 DAH, total length of larvae reared at 3000 lx was significantly larger than those reared at the lower light intensities (0, 500 and 1000 lx), and thereafter light intensity significantly influenced larval feeding and growth until the end of the experiment. Survival on 5 DAH did not show a significant difference between light intensities, but survival rate at 3000 lx and 1000 lx had a tendency to be higher than those reared at the lower light intensities (0 and 500 lx). In contrast, larvae reared at 0 lx exhibited stagnant and/or negative growth. These results indicate that light intensity is significantly the factor affecting larval feeding, growth, and survival in coral grouper larvae under the rearing conditions.     

Post-release movement and diel activity patterns of hatchery-reared and wild black-spot tuskfish <Emphasis Type="Italic">Choerodon schoenleinii</Emphasis> determined by ultrasonic telemetry

ABSTRACT:   Post-release movement and diel activity patterns of hatchery-reared and wild black-spot tuskfish were examined using ultrasonic telemetry. Five hatchery-reared and four wild fish were released in the sandy bottom of Urasoko Bay, Ishigaki Island, Okinawa, Japan, and monitored using automated monitoring receivers from November 2005 to February 2006. Both hatchery-reared and wild fish tended to stay near the release site for over two weeks, before leaving the release site. Both hatchery-reared and wild tuskfish showed diurnal rhythm intermittently; signals were recorded more frequently in the daytime and less frequently in the nighttime, suggesting that the fish of both origins were active during the day and inactive during the night. These findings indicate that the one-year-old hatchery-reared tuskfish have some consistent behavioral characteristics with those of the wild.     

Reproductive season and female maturity size of coconut crab <Emphasis Type="Italic">Birgus latro</Emphasis> on Hatoma Island,southern Japan

Information about reproductive season, size at sexual maturity and size-dependent reproductive potentials is important for efficient resource management. Such information is necessary to determine seasonal closures and minimum legal size limits. To conserve resources of coconut crab Birgus latro, which are in danger of extinction due to excessive exploitation, their reproductive season, female size at functional maturity and relationship between female size and reproductive potentials were investigated. The reproductive season started in early June and ended late August, and females with higher reproductive potentials showed a tendency to spawn early in the reproductive season. The prohibition of exploiting the resources during the reproductive season, especially early in the season, would be appropriate for sustainability of high reproductive outputs. Fifty percent of investigated females matured functionally at 24.5-mm thoracic length (TL). However, the size at which all females reached functional maturity was 32.3 mm TL, and there was a wide variation in the size of functional maturity among individuals. We must determine minimum legal size by taking the variation into account to allow all individuals to mate at least once before they are caught, which may prevent serious depression in reproductive rate and genetic diversity.     

Stimulation of axillary shoot formation of cuttings of Hylocereus trigonus (Cactaceae) by pre-soaking in benzyladenine solution

Either before or after curing their cut surfaces for 5 days, 7 cm- and 15-cm-long decapitated Hylocereus trigonus cuttings were treated by soaking their apical or basal ends in benzyladenine (BA) solution. They were then planted and grown in a greenhouse.For the 7 cm-long cuttings, BA (25–100 mg l^?1) applied to the apical ends for 24 h increased the ratio of cuttings with sprouted buds to 64–100%, the number of sprouted buds to 1.9–3.1 and of shoots to 1.6–2.8, and the shoot length to 35–60 mm, compared to the water control which showed 13%, 1.0, 1.0 and 12.5 mm, respectively. Soaking the basal part had only a small effect.Naphthylacetic acid (NAA) applied to the basal ends of cuttings immediately after cutting increased the number of sprouted buds and shoots by inducing early rooting. The number and length of BA-induced axillary shoots in the longer cuttings was greater than those in the shorter ones.In the 15-cm-long cuttings, increasing the soaking time from 5 min to 24 h resulted in a greater promotive effect of BA on shoot formation. BA applied before curing showed the same effect as that given after curing but caused necrosis of the tissue just under the cut surface. Enlarging the area soaked in BA solution from 5 cm to 10 cm decreased the number of sprouting buds and shoots.     

A novel method for the reinforcement of harp soundboard

The effects of a carbon fiber-reinforced plastic (CFRP) overlay on the wooden soundboard of a harp were compared to those of conventional veneer reinforcement with respect to the vibrational properties and bending strength. CFRP reinforcement has a minimal effect on the vibrational properties of the soundboard in its width direction, whereas conventional veneer reinforcement significantly reduces the acoustic conversion efficiency of the soundboard. The CFRP-reinforced soundboard also has sufficient bending strength in its longitudinal direction. These results indicate that CFRP is a promising material for the reinforcement of the wooden soundboards of harps to minimize the reduction of the sound amplitude.     

Vibrational properties of harp soundboard with respect to its multi-layered structure

The vibrational properties of a harp soundboard were investigated with respect to its multi-layered structure. The surfaces of harp soundboards are usually reinforced with veneer; however, this reduces the specific dynamic Young’s modulus (E′/ρ) and significantly increases the internal friction (Q ^?1) of soundboards. Since smaller E′/ρ and greater Q ^?1 values impart a smaller acoustic conversion efficiency, the attachment of veneer is predicted to reduce the amplitude of the sound produced, as suggested by harp makers. The vibrational properties of veneer-reinforced wood are elucidated using a multi-layered model comprising base wood, a glue layer, veneer and a varnish layer. The results of calculations suggest that a thinner veneer attached with minimal glue would increase the sound amplitude.     

Interannual variability of net ecosystem production for a broadleaf deciduous forest in Sapporo, northern Japan

To estimate net ecosystem production (NEP), ecosystem respiration (R _E), and gross primary production (GPP), and to elucidate the interannual variability of NEP in a cool temperate broadleaf deciduous forest in Sapporo, northern Japan, we measured net ecosystem exchange (NEE) using an eddy covariance technique with a closed-path infrared gas analyzer from 2000 to 2003. NEP, R _E, and GPP were derived from NEE, and data gaps were filled using empirical regression models with meteorological variables such as photosynthetic active radiation and soil temperature. In general, NEP was positive (CO₂ uptake) from May to September, either positive or negative in October, and negative (CO₂ release) from November to the following April. NEP rapidly increased during leaf expansion in May and reached its maximum in June or July. The four-year averages (±?standard deviation) of annual NEP, GPP, and R _E were 443?±?45, 1,374?±?39, and 931?±?11?g?C?m^?2?year^?1, respectively. The lower annual NEP and GPP in 2000 may have been caused by lower solar radiation in the foliated season. During the foliated season, monthly GPP varied from year to year more than monthly R _E. Variations in the amount of incoming solar radiation may have caused the interannual variations in the monthly GPP. Additionally, in May, the timing of leaf expansion had a large impact on GPP. Variations in GPP affected the interannual variation in NEP at our site. Thus, interannual variation in NEP was affected by the incoming solar radiation and the timing of leaf expansion.     

Growth performance and leaf ecophysiological traits in three Aquilaria species in Malaysia

New Forests - The genus Aquilaria (Thymelaeaceae) is widely used for the production of agarwood, and includes several valuable plantation species in Southeast Asia. To understand appropriate...