Effects of light and microsite conditions on tree size of 6-year-old Cryptomeria japonica planted in a group selection opening

We examined the extent to which direct and indirect measures of light and microsite conditions could explain variation in tree height and diameter at the base of 6-year-old Cryptomeria japonica trees planted in a group selection opening of about 0.32 ha on a steep slope at Shiiba, Miyazaki Prefecture, southern Japan. We first used the gap light index (GLI) and soil thickness (ST) as directly measured indices. For an indirect measure of light, we used a between-cohort competition index (BCI) estimated from the position and total height of residual trees. For indirect measures of microsite, we examined topographic indices (slope, plan and profile curvature, average slope gradient, and relative elevation) derived from digital elevation models (DEMs) with different resolutions ranging from 2 to 10 m. The multiple linear regression using GLI and ST explained about 45% of variation in tree size, while simple regression using only GLI explained about 35%. The contribution of ST was about half of GLI. The multiple regressions using BCI and the topographic indices did not explain any more variation than using BCI alone (R ² of about 0.26). We conclude that microsite conditions with shallower soil and steeper slope have negative effects on tree growth in group selection openings, although the relative importance is smaller than light conditions. More comprehensive studies considering several openings with more heterogeneous topography including different species are needed to generalize our growth prediction using the indirect measures, which are useful for practical forest management.     

Accessory corpora lutea formation in pregnant Hokkaido sika deer (Cervus nippon yesoensis) investigated by examination of ovarian dynamics and steroid hormone concentrations

Generally, sika deer conceive a single fetus, but approximately 80% of pregnant females have two corpora lutea (CLs). The function of the accessory CL (ACL) is unknown; moreover, the process of ACL formation is unclear, and understanding this is necessary to know its role. To elucidate the process of ACL formation, the ovarian dynamics of six adult Hokkaido sika deer females were examined ultrasonographically together with peripheral estradiol-17β and progesterone concentrations. ACLs formed in three females that conceived at the first estrus of the breeding season, but not in those females that conceived at the second estrus. After copulation, postconception ovulation of the dominant follicle of the first wave is induced by an increase in estradiol-17β, which leads to formation of an ACL. A relatively low concentration of progesterone after the first estrus of the breeding season is considered to be responsible for the increase in estradiol-17β after copulation.     

Growth,Reproductive Performance,Carcass Characteristics and Meat Quality in F1 and F2 Progenies of Somatic Cell-Cloned Pigs

The objective of this study was to examine the health and meat production of cloned sows and their progenies in order to demonstrate the application of somatic cell cloning to the pig industry. This study compared the growth, reproductive performance, carcass characteristics and meat quality of Landrace cloned sows, F1 progenies and F2 progenies. We measured their body weight, growth rate and feed conversion and performed a pathological analysis of their anatomy to detect abnormalities. Three of the five cloned pigs were used for a growth test. Cloned pigs grew normally and had characteristics similar to those of the control purebred Landrace pigs. Two cloned gilts were bred with a Landrace boar and used for a progeny test. F1 progenies had characteristics similar to those of the controls. Two of the F1 progeny gilts were bred with a Duroc or Large White boar and used for the progeny test. F2 progenies grew normally. There were no biological differences in growth, carcass characteristics and amino acid composition among cloned sows, F1 progenies, F2 progenies and conventional pigs. The cloned sows and F1 progenies showed normal reproductive performance. No specific abnormalities were observed by pathological analysis, with the exception of periarteritis in the F1 progenies. All pigs had a normal karyotype. These results demonstrate that cloned female pigs and their progenies have similar growth, reproductive performance and carcass quality characteristics and that somatic cell cloning could be a useful technique for conserving superior pig breeds in conventional meat production.     

Functions of Chisan dams in large-scale granular mass-flow experiments on Sakurajima volcano pumiceous clasts

We investigated the fundamental behaviour of Chisan (check) dams in response to the presence or absence of impounded sediment with different levels of saturation. Large-scale model flume experiments were conducted by use of a model Chisan dam that had been backfilled with pumiceous clasts taken from the Sakurajima volcano in Kagoshima prefecture, Japan. In these experiments, the miniature dam was situated midway down the flume under different backfill sediment conditions and the basal pore-fluid pressure, normal flow depth, and impact load of the granular mass were carefully monitored. Saturated sediment with a volume of 0.6 m³ was released along the slope of the flume segment at 30° and excess pore-fluid pressure was generated, corresponding to a sediment velocity of approximately 4.8 m s^?1. Direct collision of the sediment with the Chisan dam meant the peak impact loads of granular mass against the back surface of the dam exceeded 157 N in experiments without backfill sediment but were as low as 32.1 N in experiments with sediment. Accordingly, placing the backfill sediment substantially reduced peak impact loads. The sediment captured by the Chisan dams was also calculated. For experiments using saturated backfill sediment, the dam captured only 35 % of the material, indicating that most of the granular mass passed over the dam. However, in experiments without backfill sediment or with unsaturated backfill sediment, over 90 % was captured. Although Chisan dams with unsaturated backfill sediment lacked pocket space, almost equivalent granular masses were trapped in these experiments. On the basis of these results, we suggest that Chisan dams with unsaturated backfill sediment could effectively counter debris flow, reducing sediment loads along the streams draining Sakurajima volcano.     

Effects of temperature on food consumption, growth and oxygen consumption of freshwater prawn Macrobrachium rosenbergii (de Man 1879) postlarvae

Effects of temperature on food consumption, growth and oxygen consumption were estimated for the freshwater prawn Macrobrachium rosenbergii postlarvae at 23 °C, 28 °C and 33 °C in the laboratory. The results showed that the animal's initial body weight had a close linear relationship with food consumption and growth. Food consumption increased directly with temperature. Consumption rates (C; mg day^?1 ind^?1 ) of the 28 °C and 33 °C groups were much higher than that of the 23 °C group (P < 0.001), and the 33 °C group's consumption rate was higher than that of the 28 °C group (P < 0.05). The relationship of food consumption with temperature and initial body weight (W; mg) could be described as: C = 0.0679W + 0.185t? 3.17. Growth increased significantly with increased temperature. The relationship among specific growth rate, temperature and initial body weight was as follows: SGR = ?0.110W + 0.213t + 0.176. However, temperature showed no effect on growth efficiency. Oxygen consumption increased significantly with temperature (P < 0.01). The weight‐specific oxygen consumption rates (mg O₂ g^?1 h^?1) at 23 °C, 28 °C and 33 °C were 0.83, 1.16 and 1.49 mg O₂ g^?1 h^?1 for 61.92 mg M. rosenbergii.     

Increase in plasma total antioxidant capacity of grazing Japanese Black heifers and cows in forestland in Japan

Blood total antioxidant capacity (TAC) has become a key bio‐marker for animal health. Forest‐grazing cattle are known to forage various native plants that have high TAC. This study evaluated differences of plasma TAC between forest‐grazing (FG) and pasture‐grazing cattle (PG). Experiment 1 monitored the plasma TAC levels of 32 Japanese Black cattle. The level in PG did not change throughout the grazing period. However, that in FG, which increased from summer, was significantly higher than that in PG through fall (P < 0.05). In experiment 2, we used nine Japanese Black heifers and investigated their blood antioxidant parameters and the TAC in plants that the cattle consumed in late June and September. The plasma TAC levels in FG were significantly higher than those in PG in both periods (P < 0.05). Plasma levels of lipid peroxidation in FG tended to be lower than that in PG (P = 0.098). Furthermore, the TAC levels in various species of shrubs and trees consumed by FG were higher than those in pasture grasses. Results of this study show that plasma TAC of grazing Japanese Black cattle in forestland increase from summer through fall.     

Effect of dietary astaxanthin rich yeast,Phaffia rhodozyma,on meat quality of broiler chickens

We evaluated effects of dietary supplementation with astaxanthin (Ax)‐rich yeast, Phaffia rhodozyma (Xanthophyllomyces dendrorhous), on broiler chicken meat quality. Fourteen‐day‐old female Ross broilers were divided into three groups: control group, Ax‐free diet; Ax 10 group, 10 mg/kg Ax diet; and Ax 20 group, 20 mg/kg Ax diet for 28 days. At 42 days old, chickens were slaughtered, and then growth performance, meat quality and sensory attributes were analyzed. Compared with the control, a* values increased significantly after slaughter and 48 h postmortem for Ax 20 samples (P < 0.05) and for b* values in Ax 20 and Ax 10 groups (P < 0.05). Cooking loss decreased in the Ax 20 group (P < 0.05). After 120 h aging, contents of several free amino acids and total free amino acid content of Ax 20 group were significantly higher than the control (P < 0.05). In sensory evaluation, meat texture attributes improved significantly in the Ax 20 group (P < 0.01). No significant changes occurred in flavor attribute scores of meat soup from the Ax 20 group compared with the control even though most assessors preferred meat soup from the Ax 20 group. Overall, Ax‐rich yeast in the diet improves broiler chicken meat quality.     

Relationship between soak time and number of enmeshed animals in experimentally lost gill nets

In order to determine the effects of ghost fishing by lost gill nets, the relationship was examined between soak time and number of enmeshed animals in experimentally lost gill nets by using diving observations. Two experimental gill nets were set at 13 m depth in Tateyama Bay, Chiba Prefecture, Japan for approximately 200 days. One gill net was deployed in a small trough surrounded by artificial reefs, and the other was deployed on an adjacent open sandy bed. Twelve species of crustaceans, six species of gastropods, and five species of bony fish were enmeshed in the experimental gill nets. The number of enmeshed animals in the artificial reef gill net was substantially larger than that in the sandy bed gill net. The number of enmeshed animals in the experimental gill nets increased rapidly within one month after deployment, and then declined gradually showing fluctuations caused by the decrease in newly enmeshed animals, and the drop off from gill nets caused by the decomposition of dead animals. The decrease in the number of enmeshed animals was expressed by logarithmic equations, and based on these equations, the duration of capture function for the lost gill nets was calculated to be 284–561 days in the artificial reef gill net and 200 days in the sandy bed gill net. The duration of capture function for the lost gill nets for non-commercial by-catch species such as small crustaceans and gastropods was longer than for commercial species such as Japanese spiny lobster and bony fish.     

用单抗研究T细胞与牛流行性白血病发生的关系

本试验对10头患流行性白血病病牛的不同器官的肿瘤组织，用8种单克隆抗体（McAb),TH14B、BAQ44A、PIg45A、BIg715A、PIg501E、cAct105、MM1A、AHCC125染色进行了观察。结果：病牛经临床病理学和免疫琼扩试验而诊断为EBL，通过免疫组织化学检测，在10个病例中发现有9个病例的肿瘤组织对B细胞属性的McAb有很强的染色反应，证明其来源于B细胞。仅有1个病例对B细胞属性的McAb着色很淡，而对T细胞属性的McAb着色很深，呈强阳性反应，说明其来源可能与T细胞有关。