991 resultados para 378.014


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From the distribution of oceanographic data (temperature and salinity) in both Arabian Gulf and Gulf of Oman, the steric components (thermal, haline and steric heights) are calculated for the upper 50m layer during different seasons. The analysis reveals relevant evidence, that temperature variations (thermal component) play a role in the fluctuations of sea level within the investigated area. The salinity variations (haline component) is only significant near the entrance. The sea level variations due to density (steric component) is low during winter and spring and high during summer and autumn. The steric height is always lower in the northern and central regions of Arabian Gulf and higher in eastern region of Arabian Gulf and in the Gulf of Oman, i.e. the surface water must flow from the Gulf of Oman to the Arabian Gulf. The steric sea level gradient around the Strait of Hormuz are 0.04 cm/km in winter, 0.04 cm/km in spring, and 0.025 cm/km in summer and 0.014 cm/km in autumn.

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青年牛(12月龄)和经产牛(7-8岁)平均卵泡数(≥2mm)及>10mm卵泡数明显高于老年牛(≥14岁)(P<0.01)。青年牛和经产牛平均卵母细胞数及平均COC数高于老年牛(P<0.05)。1和2级卵母细胞比例青年牛高于或等于经产牛高于老年牛,3和4级卵母细胞比例老年牛高于经产牛高于或等于青年牛(P<0.05)。青年牛和经产牛2级卵母细胞占优势,而老年牛3级卵母细胞居多。不同剂量外源性FSH诱导后,经产牛和老年牛平均卵泡数在各剂量组之间没有显著差异(P>0.05);但≥6mm卵泡数及2级卵母细胞比例明显增加,而2-5mm卵泡数相应减少及裸卵和老化卵比例降低(P<0.05)。在10次取卵过程中,青年牛和经产牛发情当天平均卵母细胞数均较以后各次的数量低(P<0.05)。

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Biological aspects, population dynamics and stock assessment of the Caspian Sea prawns Palaemon adspersus and Palaemon eleganse were investigated in Guilan coastal water of the Caspian Sea. Sampling was done monthly with a bottom trawl with mesh size of 3 mm in cod end in 0 - 5 m and 5 - 10 m depth in areas as Astra, Shafa Roud, Anzali, Chonchanan Chamkhaleh and Chaboksar during year 2002. Results of one year sampling showed that mean total length of Palaemon adspersus (pooled data) was 39.9±6.84 mm (X±SD) and mean wiegth was 1.133±0.67 g. The mean total length of females and males was 41.6±7.5 mm and 37.9±5.2 mm respectively and mean weight for the mentioned sexes was 1.353±0.65 g and 0.868±0.38 g respectively. There was significant differences in mean length and weight of females and males (P<0.05). The mean total annual sex ratio of males: females for this species was 1.4 and this sex ratio deviated significantly from 1:1 (X2, P<0.05) and biased towards males in the population of this species. The spawning season of Palaemon adspersus begins in April and ends in September with a peak in June . Mean fecundity of this species was 1994.5 ± 506.6 . The growth coefficients Loo and K for females were estimated as 58.5 mm and 2.3 /Year and for males as 55.9 mm and 2.6 /year respectively . The mean CPUA ( catch / Km2 ) for this species was 9.99 ± 33.2 kg / km2 and the correspondance biomass was calculated as 5067.7 kg in 0 - 10 m depth . The mean total length of Palaemon elegans (pooled data ) was 27.5 ± 5.7 mm (X±S.D) and mm and 24.01±4.18 mm respectively and mean weight for the mentioned sexes were was 0.553 ± 0.3 g and 0.237±0.15 g respectively. There was significant differences in mean length and weight of females and males (P<0.05). The mean total annual sex ratio of males:females for this species was 0.57 and in this species also sex ratio differed significantly from 1:1 (X2, P<0.05) and skewed towards females in the population of this species. The spawning season of Palaemon elegans extended from May to September with a peak in July . Mean fecundity of this species was 642.7±313.4. The growth coefficients LOO and K for females were estimated as 42.119 mm and 2.40 /Year and 33.87 mm and 2.50 /year for males respectively. The mean. CPUA ( catch/ Km2 ) for this species was 0.75±3.86 kg/km2 and the correspondance biomass was calculated as 382.1 kg in 0-10 m depth .

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We have cloned a mouse homologue (designated Myak) of the yeast protein kinase YAK1. The 1210 aa open reading frame contains a putative protein kinase domain, nuclear localization sequences and PEST sequences. Myak appears to be a member of a growing family of YAK1-related genes that include Drosophila and human Minibrain as well as a recently identified rat gene ANPK that encode a steroid hormone receptor interacting protein. RNA blot analysis revealed that Myak is expressed at low levels ubiquitously but at high levels in reproductive tissues, including testis, epididymis, ovary, uterus, and mammary gland, as well as in brain and kidney. In situ hybridization analysis on selected tissues revealed that Myak is particularly abundant in the hormonally modulated epithelia of the epididymis, mammary gland, and uterus, in round spermatids in the testis, and in the corpora lutea in the ovary, Myak is also highly expressed in the aqueduct of the adult brain and in the brain and spinal cord of day 12.5 embryos, Mol. Reprod. Dev. 55:372-378, 2000. (C) 2000 Wiley-Liss, Inc.

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为从活性氧(ROS)角度探讨微囊藻毒素(MC)导致藻类细胞死亡的机理及揭示藻细胞对MC诱发的氧化胁迫的响应机制,采用50和500μg·L-1的微囊藻毒素LR(MC-LR)处理束丝藻(Aphanizomenon sp. DC01)细胞,测定了细胞生长、细胞内活性氧(ROS)含量及抗氧化系统的变化.结果表明,50μg·L-1的MC-LR处理对藻细胞的生长无显著影响,而500μg·L-1的MC-LR处理可诱导藻细胞死亡.50μg·L-1的MC-LR处理的藻细胞ROS含量在处理第2d显著高于对照;但藻细胞能通过还

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对云南6个高原湖泊沿岸带底栖藻类的群落结构、现存量等进行了调查,研究期间发现底栖藻类群落主要由绿藻门的刚毛藻(Cladophora spp.)和硅藻门的一些附植种类组成,除硅藻群落在泸沽湖占优势外,其它湖泊中绿藻群落的相对比率高于硅藻。底栖藻类现存量(chl a)以星云湖最高(24μg·cm-2);底栖硅藻密度以泸沽湖的鸟岛最高,为9.3×106cells·cm-2。分析不同湖泊底栖硅藻的群落结构发现:底栖硅藻Epithemia sorex和Cocconeis klamathensis分别是泸沽湖和抚仙湖

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Service-Oriented Architecture (SOA) and Web Services (WS) offer advanced flexibility and interoperability capabilities. However they imply significant performance overheads that need to be carefully considered. Supply Chain Management (SCM) and Traceability systems are an interesting domain for the use of WS technologies that are usually deemed to be too complex and unnecessary in practical applications, especially regarding security. This paper presents an externalized security architecture that uses the eXtensible Access Control Markup Language (XACML) authorization standard to enforce visibility restrictions on trace-ability data in a supply chain where multiple companies collaborate; the performance overheads are assessed by comparing 'raw' authorization implementations - Access Control Lists, Tokens, and RDF Assertions - with their XACML-equivalents. © 2012 IEEE.

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在描述鳞片、背鳍条和矢耳石三种材料轮纹特征的基础上 ,比较了这些年龄鉴定材料在判读错鄂裸鲤年龄和反映生长特征上的异同。在个体早期生长阶段 ,耳石轮纹阻断、8龄以上个体鳞片上年轮环纹的缺失和背鳍条出现轮纹的重叠是影响错鄂裸鲤年龄准确判读的主要因素。采用耳石和鳞片的体长退算数据 ,VonBertalanffy方程较好地描述了错鄂裸鲤的生长。由于背鳍条的生长在个体的生长过程中始终呈现为负的异速生长 ,因此耳石、鳞片在解释个体生长时优于鳍条

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国家自然科学基金;淡水生态与生物技术国家重点实验室资助