985 resultados para 436
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Age and growth of sailfish (Istiophorus platypterus) in waters off eastern Taiwan were examined from counts of growth rings on cross sections of the fourth spine of the first dorsal fin. Length and weight data and the dorsal fin spines were collected monthly at the fishing port of Shinkang (southeast of Taiwan) from July 1998 to August 1999. In total, 1166 dorsal fins were collected, of which 1135 (97%) (699 males and 436 females) were aged successfully. Trends in the monthly mean marginal increment ratio indicated that growth rings are formed once a year. Two methods were used to back-calculate the length of presumed ages, and growth was described by using the standard von Bertalanffy growth function and the Richards function. The most reasonable and conservative description of growth assumes that length-at-age follows the Richards function and that the relationship between spine radius and lower jaw fork length (LJFL) follows a power function. Growth differed significantly between the sexes; females grew faster and reached larger sizes than did males. The maximum sizes in our sample were 232 cm LJFL for female and 221 cm LJFL for male.
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1.对嗜热蓝藻层理鞭枝藻(Mastigocladus laminosus)藻胆体的光谱特性和光能传递进行了研究。其完整藻胆体的吸收峰位于622 nm,室温荧光发射峰位于673 nm。在77K荧光发射光谱中,完整藻胆体的荧光峰只有一个,位于685 nm,是末端发射体1的荧光。在低浓度磷酸缓冲液中发生严重解离的藻胆体,其77K荧光发射光谱中有二个发射峰和一个发射肩。两个荧光发射峰分别位于644 nm和683 nm。前者为主峰,属于C-藻蓝蛋白的荧光,后者是次峰,属于末端发射体2的荧光。荧光发射肩位于660 nm附近,属于别藻蓝蛋白的荧光。据此,提出层理鞭枝藻藻胆体光能传递途径如下: 藻红蓝蛋白→c—藻蓝蛋白→别藻蓝蛋白→端发射体l、末端发射体2: 2.对嗜热蓝藻层理鞭枝藻藻胆体—类囊体膜的光谱特性和光能传递进行了研究。在吸收光谱中,其藻胆体——类囊体膜在可见光区域有5个峰,它们分别位于420 nm、438 nm、490 nm、624 nm和678 nm。420 nm、438 nm和678 nm为叶绿素a的吸收峰位置。490 nm是类胡罗卜素的吸收峰,624 nm是藻胆体的吸收峰。对藻胆体——类囊体膜用580 nm波长的光激发藻胆蛋白时,在室温荧光发射光谱中有一个发射峰和一个发射肩,分别位于657 nm和690 nm,前者属于藻胆蛋白的荧光,后者属于叶绿素a的荧光。这说明藻胆蛋白能将捕获的光能传递给类囊体膜上的叶绿素a。在77K荧光发射光谱中有4个峰,它们分别位于649 nm、660 nm、688 nm和730 nm。前二者属于藻胆蛋白的荧光,后二者属于叶绿素a的荧光。这同样说明藻胆蛋白能将捕获的光能传递给类囊体膜上的叶绿素a。当用436 nm波长光激发叶绿素a时,藻胆体——类囊体膜的室温荧光发射光谱中有两个荧光峰出现,位于685 nm的峰来源于光系统Ⅱ,位于713 nm的峰来源于系统I。这说明叶绿素a捕获的光能不能逆传递给藻胆体中的藻胆蛋白。在77K荧光发射光谱中也只有叶绿素a的荧光峰,位于695 nm的峰来源于光系统Ⅱ,位于730 nm的峰来源于光系统l。此结果同样说明叶绿素a捕获的光能不能逆传递给藻胆蛋白. 3.我们以多变鱼腥藻(Anabaena variabilis)为材料,对其藻胆体核心和藻蓝蛋白进行了重组实验,得到了具有光能传递效率的藻胆体核心——藻蓝蛋白复合物。在吸收光谱中,藻胆体核心有一吸收峰和一个吸收肩,分别位于654 nm和600 nm。藻蓝蛋白的吸收光谱中只有一个峰,位于620 nm.重组样品的吸收光谱有一吸收峰和一吸收肩,分别位于654 nm和620 nm.由于620 nm与654 nm的吸收比远大于核心的600 nm与654 nm的吸收比,因此,可以认为部分藻蓝蛋白已与核心重组。在室温荧光发射光谱中,藻胆体核心只有一个峰,位于676 nm。藻蓝蛋白只有一个峰,位于653 nm。重组样品有一荧光发射峰和一荧光发射肩,分别在669 nm和650 nm附近。669 nm荧光来源于核心,650 nm荧光来源于藻蓝蛋白。重组后的核心的650 nm荧光显著大于未重组的核心,这也说明部分藻蓝蛋白与核心已重组.在77K荧光发射光谱中,藻蓝蛋白只有一个峰,位于655 nm。藻胆体核心有二个峰,分别位于666 nm和686 nm。重组样品有两个荧光发射峰和一荧光发射肩,分别位于666 nm、683 nm和648 nm附近.重组的核心的别藻蓝蛋白的荧光(F666)和藻蓝蛋白的荧光(F648)都强于未重组的核心。这一结果同样说明有藻胆体——藻蓝蛋白复合物生成。 除以上研究工作之外,我们还对多变鱼腥藻藻胆体在解离过程中的光谱特性及光能传递、藻胆体——类囊体膜的光谱特性及光能传递、藻胆体解离重组、藻胆体核心在低浓度磷酸缓冲液中的光谱特性、以及温度对藻胆体核心的影响等进行了研究。研究结果有待整理。 本文编写:PBS:藻胆体;PEB:藻红胆素;PE:藻红蛋白;PUB:藻尿胆素;PEC:藻红蓝蛋白;PCB:藻蓝胆素;PC:藻蓝蛋白;PSⅡ:光系统Ⅱ;APC:别藻蓝蛋白;PS I:光系统I;TE:末端发射体
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利用经酸处理的Sepharose 4B为层析介质,以含0.2mol/L半乳糖,pH7.4台氏液作为洗脱液,从广西产金环蛇(Bungarus fasciatus)蛇毒中一步分离得到一种磷脂酶A_(2)。用SDS-聚丙烯酰胺凝胶电泳测定其分子量为14kDa。N端部分序列测定表明,所分离得到的磷脂酶A_(2)其N端16个氨基酸残基序列与已报道的金环蛇蛇毒磷脂酶A_(2)同功酶Ⅵ(Lu&Lo,1978)一致。该酶糖含量较高,为13.4%;具有弱的磷脂酶A_(2)活性,无毒,也无溶血和出血毒活性。
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滇金丝猴(Rhinopithecus bieti)是我国著名的濒危保护动物.迄今为止,关于滇金丝猴并基于DNA序列的群体遗传学研究还没有报道.文章测定了来自于云南省维西县滇金丝猴群体样本的线粒体控制区全序列以及部分个体的细胞色素b全序列.在排除了核线粒体假基因存在的可能性之后,滇金丝猴维西群体内部被确认存在着两个序列分歧较大的分枝.即使如此,如果考虑到群体结构和迁移的影响,维西群体的遗传多样性水平可能并不高.
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The 4-bp deletion (-CTTT) at codon 41/42 (CD41/42) of the human beta-globin gene represents one of the most common beta-thalassemia mutations in East Asia and Southeast Asia, which is historically afflicted with endemic malaria, thus hypothetically evolvi
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The karyotype of Indian muntjacs (Muntiacus muntjak vaginalis) has been greatly shaped by chromosomal fusion, which leads to its lowest diploid number among the extant known mammals. We present, here, comparative results based on draft sequences of 37 bac
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1994年9月, 中国科学院昆明动物研究所灵长类生物学研究室学者徐林赴英国伦敦大学药理系进修, 1995年6月转入爱尔兰都柏林大学药理和治疗系攻读电生理学博士学位.在此期间, 他在学习记忆的细胞分子机理研究方面取得了新突破, 研究结果已在《Nature》(Vol. 387/29 May 1997)正式发表。
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疣螈属的红瘰疣螈(Tylototriton shanjing)和棕黑疣螈(T.verrucosus)的物种界限一直不清楚.测定了来自中国西南地区14个地点的T.shanjing和T.verrucosus共40只标本的线粒体DNA Cyt b基因(753 bp).结果表明:(1)用邻接法、最大简约法和贝叶斯法等3种系统发育分析法分别重建棕黑疣螈种组系统发育树的拓扑结构不支持T.shanjing是单系群;(2)T.shanjing与T.verrucsus的mtDNA Cyt b序列差异平均值仅为1.2%.未达到种级水平.因此,全部T.shanjing样品都属于同一个物种,即T.verrucosus,不支持T.shanjing的物种地位,T.shanjing为T.verrucosus的同物异名,并建议恢复T.verrucosus的中文名红瘰疣螈.根据基于40个样品Cvt b基因序列的系统发育树和遗传变异以及地理分布,这些红瘰疣螈(T.verrucosus)样品聚为3支,即中国西南地区的红瘰疣螈可分为片马、滇中滇西和滇东南3个地理居群.
Prenatal stress modifies hippocampal synaptic plasticity and spatial learning in young rat offspring
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Clinical studies demonstrate that prenatal stress causes cognitive deficits and increases vulnerability to affective disorders in children and adolescents. The underlying mechanisms are not yet fully understood. Here, we reported that prenatal stress (10
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In the present study, ectoparasite infestation of common freshwater ornamental fish species imported into Iran including: Dwarf gourami (Colisa lalia), Angelfish (Pterophyllum scalare), Oscar (Astronatus ocellatus), Red eye Tetra ( Moenkhansia Sanctaefilomenae), Barb( Capoeta tetrazona), Arowana (Osteoglossum bicirrhosum), Goldfish(Carassius auratus), Red fin Shark (Lebeo elythrurus, Catfish (Hypostomus plecostomus) and Pangasius sutchi ( Pangasius hypophthalmus) from May until April was investigated.A total of 6 specimens sample of each fish species) randomly were obtained and taken alive to the lab. After observing gill and skin wet smear under the microscope , gill was dissected and examined carefully .Photo and films were taken from the isolated parasites and parasite identification was performed according to Yamaguti AP1), Bychowsky (■Y).From a total of examined fishes 1\ ► sample (YY.V.) were parasitized .Parasite groups that were observed consisting ciliated protozoan myxosporidian , monogenean Digenean metacercaria and crustacean .The only non-parasitized fish was Barb. Monogenea Trianchoratus sp. , Cleidodiscus sp. , Ancylodiscoides sp. , Thaparocleidus sp. , Centrocestus formosanus metacercaria and Myxobolus longisporus report for the first time in ornamental fish which imported from Southeast of Asia to Iran. According to the results, it seems that severe quarantine and sanitary rules are necessary.