Diatoms and the ecological conditions of their growth in sea ice in the arctic ocean     

Meguro H  Ito K  Fukushima H 《Science (New York, N.Y.)》1966,152(3725):1089-1090

A summer field survey off Point Barrow, Alaska, revealed that Arctic sea ice develops a growth of phytoplanktonic diatoms. The diatoms are found in a brine solution in microfissures between ice crystals on the underside of the ice. The chlorophyll content of this layer is 100 times more than that of the surrounding sea waters; this has led to a hypothesis that a considerable fraction of the primary production of the Arctic Sea may be carried out in sea ice, especially during the spring and early summer months.  相似文献   

The mode of operation of a regulating reservoir for effective use of river flow     

Shinichi Nishimura  Sang-bong Lee  Kengo Ito  Masateru Senge 《Paddy and Water Environment》2005,3(3):149-154

In the absence of a reservoir on the downstream side, a river flow that increases temporarily by rainfall cannot be stored and discharged apart from requirements in a command area. This unused water (excess water) occurs to some extent even in a drought year and making effective use of this supply is considered as one of the countermeasures for water shortage. Setting up a regulating reservoir on the upstream side of head works is regarded as one of the methods for making effective use of excess water. The inflow to the river and water delivery loss occurred from rainfall are stored in the regulating reservoir and supplied to the command area on the downstream side as agricultural water. An operational method for the regulating reservoir to effectively utilize the excess water was examined for a canal system by simulation. In an investigated area, there was excess water even in drought years, and making use of it through the regulating reservoir whose capacity is smaller compared to that of a dam can become one of the countermeasures for the drought period. The simulation in this study could estimate quantitatively the effect of the regulating reservoir to make the excess water effective.  相似文献   

古梅灵芝和梅子精抗过敏性作用的研究     

松本紘齐  伊藤均  伊藤浩子 《北京林业大学学报》1999,21(2):77-80

抑制组胺游离和肠管收缩等过敏反应的研究表明,对于由Ｃｏｍｐｏｕｎｄ４８／８０或ＩｇＥ抗血清反应引起的老鼠腹腔细胞中组胺的游离及外源组胺引起的土拨鼠肠管的收缩,古梅灵芝和梅子精均有明显的抑制作用．  相似文献   

湖北省杜仲种质资源收集与繁殖保存研究   总被引：3，自引：0，他引：3  

周志翔  王鹏程 《华中农业大学学报》1998,17(5):507-511

以湖北省杜仲资源调查为基础,分析了湖北省杜仲资源的分布特点及生长差异,对不同类型的杜仲种质资源进行了收集和繁殖试验,确定了影响杜仲繁殖保存效果的主导因子,为湖北省杜仲种质资源的保存和利用提供了依据。  相似文献   

Genetic variation in resistance of the tiger pufferfish Takifugu rubripes to a host-specific monogenean parasite Heterobothrium okamotoi     

Kim  Dong In  Hosoya  Sho  Mizuno  Naoki  Ito  Kotaro  Ieda  Risa  Kikuchi  Kiyoshi 《Fisheries Science》2019,85(6):1019-1025

Fisheries Science - The tiger pufferfish Takifugu rubripes is one of the most valuable aquaculture species in Japan. In this study, we investigated the genetic variation in resistance to...  相似文献   

Glycosphingolipid receptors for pathogenic vibrios in intestines of mariculture fish     

Naoyuki Matsunaga  Shin-ichi Chisada  Hideyuki Fujioka  Kana Takashima  Nozomu Okino  Makoto Ito 《Fisheries Science》2011,77(4):583-590

Vibrios are highly motile, facultatively anaerobic bacteria that are ubiquitous in aquatic environments and part of the normal intestinal microflora of healthy fish, but some species can cause vibriosis. The adherence of vibrios to host fish intestines is a significant event not only for their survival and growth, but also in terms of pathogenicity. However, the molecular mechanism underlying the adhesion of vibrios to the intestinal tract of fish is not fully understood. We report here the identification of intestinal glycosphingolipid (GSL) receptors to which pathogenic vibrios attach in typical mariculture fish. Thin-layer chromatography overlay assays using five species of ³⁵S-labeled vibrios and intestinal glycosphingolipids of seven species of mariculture fish revealed that all of the fish tested possessed GM3 (NeuAcα2-3Galβ1-4Glcβ1-1′Cer) and/or GM4 (NeuAcα2-3Galβ1-1′Cer) as major acidic intestinal GSLs and that all of the vibrios tested specifically adhered to GM3 and/or GM4. Our results demonstrate that these GSLs were able to function as a receptor for the various vibrios tested. Analysis of the relationship between sugar structure and receptor activity for vibrios revealed that ‘NeuAcα2-3Galβ1-’ is required at the non-reducing end of glycosphingolipids for the bacteria to attach.  相似文献   

Influence of Amylose Content on Cookie and Sponge Cake Quality and Solvent Retention Capacities in Wheat Flour     

Zenta Nishio  Hanaki Oikawa  Takanobu Haneda  Masako Seki  Miwako Ito  Tadashi Tabiki  Hiroaki Yamauchi  Hideho Miura 《Cereal Chemistry》2009,86(3):313-318

Reduced amylose wheat (Triticum æstivum L.) produces better quality noodles and bread less prone to going stale, while little is known about the relationships between amylose content and the quality of soft wheat baking products such as sugar snap cookies (SSC) and Japanese sponge cakes (JSC). Near‐isogenic lines developed from wheat cultivar Norin 61, differing in their level of granule‐bound starch synthase (Wx protein) activity, were used to produce wheat grains and ultimately flours of different amylose contents. These were tested with regard to their effect on soft wheat baking quality and solvent retention capacities (SRC). Amylose content was strongly correlated to cookie diameter (r = 0.969, P < 0.001) and cake volume (r = 0.976, P < 0.001), indicating that the soft wheat baking quality associated with SSC diameter and JSC volume were improved by an incremental increases in amylose content. Among the four kinds of SRC tests (water, sodium carbonate, sucrose and lactic acid), the water SRC test showed the highest correlation with amylose content, SSC diameter, and JSC volume. When the regression analysis was conducted between the nonwaxy and partial waxy isogenic lines that are available in commercial markets, only water SRC was significantly correlated to amylose content (r = –0.982, P < 0.001) among of four SRC tests. This suggests that, unlike udon noodle quality, high‐amylose content is indispensable in improving soft wheat baking quality, a process requiring less water retention capacity.  相似文献   

冻融作用下特定污染物的清洗试验研究     

芮大虎  张军  武迎飞  杨建辉  伊藤譲 《保鲜与加工》2017,(4):69-75

抽出处理法是目前修复土壤污染常用的方法之一，为了解决抽出处理法中对渗透性差的土中污染物和低浓度污染物效率低的问题，利用土体冻结过程中在一定的温度梯度和水分条件下未冻土侧水分（溶质）向冻结锋面迁移和冻融作用导致渗透性增强的特性，开展了基础试验。试验将混有模拟污染物NaCl溶液的粘土作为研究对象，结合传统的抽出处理法，实施了单向冻融试验和污染物清洗模型试验，探索了利用冻融现象清洗污染土壤的可行性。结果表明，冻融作用有助于提高污染物的抽出效率。  相似文献   

Effect of Growing Environment of Soft Wheats on Amylose Content and Its Relationship with Cookie and Sponge Cake Quality and Solvent Retention Capacity     

Zenta Nishio  Yuri Miyazaki  Masako Seki  Miwako Ito  Tadashi Tabiki  Koichi Nagasawa  Hiroaki Yamauchi  Hideho Miura 《Cereal Chemistry》2011,88(2):189-194

The effect of growing environments of soft wheat on amylose content and its relationship with baking quality and solvent retention capacities (SRC) was investigated. Near‐isogenic soft wheat lines of Norin 61 differing in granule‐bound starch synthase (Wx protein) activity and grown in three different regions of Japan: Hokkaido (spring‐sown) for 2006 and 2007, Kanto (autumn‐sown), and Kyushu (autumn‐sown) for 2007 were evaluated. Spring‐sown samples produced grains of greater protein content (10.9–12.4%) than autumn‐sown samples (7.3–9.1%). In contrast, spring‐sown samples of 2007 with higher maturing temperature had lower amylose content (25.5% for Norin 61) compare to the autumn‐sown and spring‐sown samples of 2006 (27.6–28.4% for Norin 61). Amylose content was strongly correlated to sugar snap cookie (SSCD) diameter (r = 0.957–0.961; n = 10, all samples; P ≤ 0.001, r = 0.701–0.976; n = 7 partial waxy and nonwaxy samples; and Japanese sponge cake (JSCV) volume r = 0.971–0.993; n = 10; P≤ 0.001, r = 0.764–0.922; n = 7 partial waxy and nonwaxy samples), regardless of seeding season and growing conditions. The strength of the JSVC‐amylose relationship (slope) was similar among the three regions, whereas the strength of the SSCD‐amylose relationship was slightly weaker for spring‐sown samples and slightly stronger for partial waxy and nonwaxy autumn‐sown samples. Among of the four solvents (water, solutions of sodium carbonate, sucrose, or lactic acid), water‐SRC showed the greatest correlation to amylose content (r = –0.969 to –0.996; n = 10; P ≤ 0.001, r = –0.629 to –0.983; n = 7 partial waxy and nonwaxy samples), indicated that amylose content can be accurately estimated from the water‐SRC within the samples from the same grown environment.  相似文献