Occurrence of toxic <Emphasis Type="Italic">Dinophysis acuminata</Emphasis> (Dinophyceae) in Uranouchi Inlet,Japan

In the Uranouchi Inlet, which has a commercial fishery of littleneck clam Ruditapes philippinarum, potentially toxigenic species of Dinophysis acuminata showed an annual occurrence except for the summer of 2000–2002. Relatively high abundances of D. acuminata were observed in April 2000 and November 2002. Some samples of D. acuminata cells, which were collected from the inlet in autumn 2002, contained pectenotoxin-2 (0.9–2.8 pg/cell) and okadaic acid (1.9–2.8 pg/cell). Cell length and hypotheca width of D. acuminata found in the Uranouchi Inlet were 33.7–45.0 and 21.0–31.6 μm, respectively. The length-width ratios ranged 1.21–1.71. Sequences of the 5.8S ribosomal RNA gene and flanking internal transcribed spacers, 1 and 2 of cells of D. acuminata from the inlet fell into a D. acuminata complex clade that included, D. acuminata-D. sacculus-D. acuta reported by others. In the inlet, occurrences of D. acuminata were detected within a broad water temperature range between 13.0 and 26.9°C, and those showing more than 25 cells/L were within 16.4–17.3°C for temperature and 27.6 and 34.1 for salinity. This is the first report that cells of Dinophysis acuminata from southern Japanese coastal waters contained okadaic acid and pectenotoxin-2.     

The respiration in leaf disks from younger taro plants under a moderate potassium deficiency

It has been reported that there is a considerable difference in the response of leaves and roots to K-deficiency (1), which may be due to the difference in the severity of the deficiency in the two tissues under the same K-application (2). The previous work (3) suggested that the metabolic disturbance induced by K-deficiency might depress preferentially the metabolism in roots rather than that in leaves. Another work with taro leaves in the later growth stage (4) suggested that any indirect metabolic disturbance caused by an extended K-deficiency might result in a depressed operation of the TCA cycle. The bleeding experiments with taro plants in the earlier growth stage (5) showed that arseniteand DNP-treatment in vivo with the roots, both reduced significantly the release rate of nitrogenous constituents and water with bleeding sap. Based on these informations, the growth and the respiration of leaves under a moderate K-deficiency were re-examined with younger taro plants in an attempt to compare them with those of the roots (4). At the conclusion of a series of studies on the nutritional physiology of taro plants, effects of Kdeficiency on the metabolic activities of the plants are discussed in special relation to the mitochondrial respiration.     

Development of room-temperature curing aqueous emulsion-type acrylic adhesive II: effect of monomer composition on the final adhesive strength

In a series of studies, development of a new aqueous emulsion-type adhesive for use with wood or paper, which does not release formaldehyde or volatile organic solvents, was attempted. For the purpose of increasing both initial and final adhesive strengths, we selected a system consisting of acrylic monomers copolymerized with functional monomers such as diacetone acrylamide and some cross-linking agents such as dihydrazide or polymeric methylene diphenyl diisocyanate (pMDI). It was found that dihydrazide cross-linker was effective for both the initial and final adhesive strengths, suggesting contribution of hydrazone bonds to the bonding strengths. Cross-linking with pMDI might be slow and was not important in the initial bonding. However, its cross-linking effect might develop gradually, because the adhesive showed good final strengths using pMDI as a cross-linker.     

Traditional seed production in landraces of daikon (Raphanus sativus) in Kyushu, Japan

Landraces of daikon, Japanese radish, Raphanus sativus var. hortensis, are grown and used traditionally in Kyushu, Japan. These landraces are maintained by seeds harvested from selected plants which are transplanted as dormant tap roots or are retained in a portion of field. Seeds kept in intact siliquas on the stems are harvested and stored until use, by hanging the dried stems. Although the relatively small number of plants used in a patch for seed production might be expected to result in a narrow base of genetic diversity of a farmers' lot in a landrace, addition of a few plants with contrasting features, pollen exchange between household patches, and contamination from other cultivars and feral forms may save the landraces from the rapid loss of diversity and deterioration caused by inbreeding depression. The seed production by transplanting described in medieval Japanese literature is relatively similar to the current practice. The factors responsible for maintenance of the landrace together with the cultural and climatic diversity of Japan may have contributed to a high diversity of landraces of the daikon. This revised version was published online in July 2006 with corrections to the Cover Date.     

Patterns of aquaporin expression in the canine eye

Aquaporins (AQPs) function as water channels in many types of cells involved in fluid transport. More than 10 isoforms have been identified, and these are differentially expressed in many types of mammalian cells in the body. Six AQPs (AQP0, AQP1, AQP3, AQP4, AQP5, and AQP9) have been identified in the eyes of humans and/or rodents. The unique permeability characteristics and distribution of AQPs indicate their diverse roles in the regulation of water homeostasis in the eye. The aim of this study was to investigate the localisation of AQPs in normal canine eyes, with AQP0 protein expressed in the crystalline lens and retina. Although AQP1 mRNA was detected in various areas of the canine eye, its protein expression was limited to the cornea, iris and ciliary body. AQP4 was identified in the iris, retina and optic nerve. AQP3 and AQP5 were found in the cornea and conjunctiva, and their expression was particularly high in the limbus. AQP3 and AQP5 were present in the nictitating membrane indicating that they play a role in water transport within the membrane. The observations suggested that several subtypes of the AQP family are involved in the regulation of water homeostasis in the canine eye.     

Estimation of genetic parameters of defective appearances in Japanese Black heifer calves in Kagoshima

Defective appearances, including white spotting (WS), tongue defect (TD), and nipple defect (ND), in Japanese Black cattle potentially lead to economic losses to farmers in Japan. We estimated genetic parameters of defective appearances using 553,433 records of Japanese Black heifer calves housed in the Kagoshima Prefecture. Variance and covariance were estimated using the Gibbs sampling algorithm. The estimated heritability ranged from 0.29 for TD to 0.76 for WS. Percent breeding value (%BV) estimates indicated high variation in WS and ND among sires, reflecting higher heritability. Furthermore, there was a positive linear relationship between the %BV estimate of a sire and the mean incidence rate of each defect in his female offsprings. TD was positively associated with other defects. Therefore, genetic factors strongly affect the incidence of defective appearances in Japanese Black cattle.     

Characterization of Waxy Rice Cakes (Mochi) with Rapid Hardening Quality by Instrumental and Sensory Methods

The textural properties of cooked waxy rice cakes made from four waxy rice varieties including the unique varieties Kantomochi 172 (K172) and BC3 with the property of rapid hardening were analyzed by instrumental and sensory methods. For the instrumental analysis, a compression test, adhesiveness test, and tensile test were conducted. The waxy rice cakes made from K172 and BC3 showed significantly higher compressive force and resistance to break under tensile load. Significant difference in amylopectin chain‐length distribution was observed between each variety, and this difference strongly reflected the hardness of waxy rice cakes. The peak area ratio of amylopectin branch chains with 6–12 degrees of polymerization negatively correlated with the compressive force required for 50 and 80% strain. Sensory evaluation showed that the waxy rice cakes made from these varieties had a significantly harder, less stretchable, less smooth surface, whereas the scores for adhesiveness and ease to cut off (hagire) were preferable to those for other rice varieties.     

脂肪酸添加剂抑制奶牛对环境污染的效果分析

将21头荷斯坦奶牛随机分为对照组和试验Ⅰ～Ⅵ组,每组3头,对照组饲喂TMR,试验Ⅰ～Ⅵ组饲喂TMR加50.0g、100.0g、150.0g、200.0g、250.0g、300.0g/头/d复合脂肪酸日粮.主要探讨复合脂肪酸对奶牛粪尿、N、P的排泄量和CH4释放量的影响.结果表明,TMR加150.0g/头/日～300.0g/头/d复合脂肪酸,比对照组CH4释放量减少11.40%～18.38%(P<0.01),粪尿和N及总P的排泄量分别降低1.38%～5.32%(P>0.05),11.84%～26.68%(P<0.01)和2.32%～4.86%(P>0.05),乳脂率提高10.76%～14.17%(P<0.05),有效抑制奶牛对周围土壤水源和空气的污染,显著提高奶牛的生态效益和经济效益.