974 resultados para PACS 42.55.Wd · 42.55.Xi


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This is a resume of a 1953-1955 study of Ceylon's fishing gears, fisheries and records of experimental and commercial fishing operations. Representative catches of edible fish per unit of effort for several of the gears studied are summarized in the table. They are low compared with many countries, indicating low abundance of fish.

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本文通过细胞遗传学、mtDNARFLP(线粒体DNA、限制性片段长度多态性)和血液蛋白及同工酶3个方面的研究,分析了云南文山黄牛和迪庆黄牛的遗传多样性和遗传分化关系。结果:(1)细胞遗传学云南两个地方黄牛品种的Y染色体形态及其C一带具有显著多态性。文山黄牛和迪庆黄牛分别为一小的近端部和亚申部(或中部)着丝位Y染色体,并分别在Y染色体的臂端部和短臂的臂端部显示弱阳性C一带,说明文山黄牛的父系起源可能是瘤牛(Bosindicus),而迪庆黄牛是普遍牛(Bostaurus)。推测两种Y染色体可能是臂问倒位的结果。(2)mtD-NARFLP两个黄牛品种的111个个体的mtDNA经8种限制性内切酶酶切后,有个酶表现出多态,共检测到17种限制性态型。归结出的3种基因单倍型,分别是A-A-A-A-A-A-A型(瘤斗)、B-B-B-B-B—B-B型(普通型)和A-C-B-B-C-A-A型(耗半Bosgrunniens)。从基因单倍型在群体中的表现可看出,文山黄牛和迪庆黄牛都具有瘤牛和普通牛两种母系起源。但文山黄牛以瘤牛血统为主,迪庆黄牛以普通牛血统为主,而且还可能含有部价耗牛的血统。(3)血液蛋白及同工酶分析了两个黄牛品种的...

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We have investigated the karyotype relationships of two oriental voles, i.e. the Yulong vole (Eothenomys proditor, 2n = 32) and the large oriental vole (Eothenomys miletus, 2n = 56) as well as the Clarke's vole (Microtus clarkei, 2n = 52), by a combined a

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The regional distribution of an ancient Y-chromosome haplogroup C-M130 (Hg C) in Asia provides an ideal tool of dissecting prehistoric migration events. We identified 465 Hg C individuals out of 4284 males from 140 East and Southeast Asian populations. We genotyped these Hg C individuals using 12 Y-chromosome biallelic markers and 8 commonly used Y-short tandem repeats (Y-STRs), and performed phylogeographic analysis in combination with the published data. The results show that most of the Hg C subhaplogroups have distinct geographical distribution and have undergone long-time isolation, although Hg C individuals are distributed widely across Eurasia. Furthermore, a general south-to-north and east-to-west cline of Y-STR diversity is observed with the highest diversity in Southeast Asia. The phylogeographic distribution pattern of Hg C supports a single coastal 'Out-of-Africa' route by way of the Indian subcontinent, which eventually led to the early settlement of modern humans in mainland Southeast Asia. The northward expansion of Hg C in East Asia started similar to 40 thousand of years ago (KYA) along the coastline of mainland China and reached Siberia similar to 15 KYA and finally made its way to the Americas. Journal of Human Genetics (2010) 55, 428-435; doi:10.1038/jhg.2010.40; published online 7 May 2010

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Of the total 240 Pangasius hypothalamus (5 - 8.7cm) fry examined during September' O1 to February'02, 80 (33.33%) were found to be infested with one or more ecroparasites irrespective of genera or groups. Seven parasitic groups were identified with the highest average prevalence of Trichodinids (55%) followed by Dacrylogyrus spp. ( 42%), Episrylis spp. (8%), Apiosoma spp. (7%) Argulus spp. (5%), Gyrodacrylus spp. (4%) and Piscicola spp. (2%) the lowest prevalent group irrespective of months. Trichodinid and Dacrylogyms spp. were recorded to be the dominating parasitic groups among the seven both in terms of monthly prevalence and severity of infestation throughout the period of investigation. The highest prevalence (60%) of ectoparasite was recorded in December and the lowest (10%) in February irrespective of groups.

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A rice-fish culture experiment with four treatments viz., T 1 with Amblyphmyngadan mala alone, T 2 with A. mala and Barbodes gonionotus, T3 with A. mala and Cyprinis carpio and T4 as control (without fish) was carried out in the rice fields during April through August1999. The recovery rate of A. mala were 42%, 37% and 42% in treatments 1, 2 and 3 respectively and the same recorded for B. gonionotus and C. cmpio were 62% and 55% respectively. Among the three species of fish, B. gonionotus showed much higher recovery rate than both of A. mala and C. carpio. The production of A. nwla was 12.50 kg/ha/3 months in monoculture, and 7.92 kglha/3 months and 8.86 kglha/3 months in combination with B. gonionotus and C. carpio, respectively. The production of B. gonionotus in T2 was 169.29 kg/ha/3 months and C. cmpio in T 3 was 252.92 kg/ha/3 months. The total fish production was 12.50 kg/ha/3 months, 175.21 kg/ha/3 months and 261.88 kg/ha/3 months in Tp T2 and T3, respectively. The highest yields of rice grain (5.78 ton/ha) and straw (7.83 ton/ha) were recorded in T3 and the lowest of the same was in T4 (grain 4.96 ton/ha and straw 6.62 ton/ha). Rice yield increased by about 12.10% in T1, 13.30% in T2 and 16.33% in T3 in context to T4, rice-alone culture. The results demonstrated that the culture of fish in rice fields had profound beneficial impact on the production of rice grain and straw.

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A novel potent trypsin inhibitor was purified and characterized from frog Bombina maxima skin. A full-length cDNA encoding the protein was obtained from a cDNA library constructed from the skin. Sequence analysis established that the protein actually comprises three conserved albumin domains. B. maxima serum albumin was subsequently purified, and its coding cDNA was further obtained by PCR-based cloning from the frog liver. Only two amino acid variations were found in the albumin sequences from the skin and the serum. However, the skin protein is distinct from the serum protein by binding of a haem b (0.95 mol/mol protein). Different from bovine serum albumin, B. maxima albumin potently inhibited trypsin. It bound tightly with trypsin in a 1: 1 molar ratio. The equilibrium dissociation constants (K-D) obtained for the skin and the serum proteins were 1.92 x 10(-9) M and 1.55 x 10(-9) M, respectively. B. maxima albumin formed a noncovalent complex with trypsin through an exposed loop formed by a disulfide bond (Cys(53)-Cys(62)), which comprises the scissile bond Arg(58)(P-1)-His(59)(P-1'). No inhibitory effects on thrombin, chymotrypsin, elastase, and subtilisin were observed under the assay conditions. Immunohistochemical study showed that B. maxima albumin is widely distributed around the membranes of epithelial layer cells and within the stratum spongiosum of dermis in the skin, suggesting that it plays important roles in skin physiological functions, such as water economy, metabolite exchange, and osmoregulation.

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PLEASE ALSO CHECK THE FULL TEXT ABSTRACT. Toxin production and toxin profiles of four Raphidophytes grown under different salinities were compared to investigate the influence of salinity on cellular content of neurotoxin. In Chatonella andqua CaTx-1, CaTx-11, and CaTx-111 peaked at 25 pplt with yields of 0.99, 0.42, and 2.90 pg/ceU, but the highest yields (2.35 pg/cell) of CaTx-IV was attained at 30 ppt. On the other hand, Chatonella marina yielded higher proportions of CmTx-1 (0.55 pg/ceH) and CmTx-111 (2.50 pg/cell) at 25 ppt. However, CmTx-IV was present in its highest amount (1.65 pg/cell) at 30 ppt, as seen in C anriqua. A smaH amount of CmTx-11 was also detected at 20-35 ppt. The toxin compositions indicate that H. akashiwo is more sensitive to higher salinities than the other three raphidophytes. Substantial compositional change was observed in case of H. akashiwo. HaTx-11 (corresponding to PbTx-9) was detected only as a trace at 20 and 25 ppt. Toxin HaTx-IV (corresponding to oxidized PbTx-2) was most dominant and peaked at 20 ppt with a yield of 0.3 pg/cell. Considerable amounts of HaTx-1 and III (corresponding to PbTx-2 and 3) were also detected. At higher salinities of above 25 ppt HaTx-11 was not detected. F. japonica gave highest yields of FjTx-11 (PbTx-2) and FjTx-IV (Oxidized PbTx-2) at 20 ppt with yields of 0.95, 1.54 pg/cell while the production of toxic profiles FjTx-1 (PbTx- 1) and FjTx-111 (PbTx-3) peaked at 25 ppt with yields of 0.99, 2.54 pg/ceU. A sharp decrease in all toxins profiles (CaTx, CmTx, HaTX and FjTx) was found at salinities of above 30 ppt.

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A Gram-negative, rod-shaped, non-motile, non-spore-forming bacterium, designated strain HR2(T) was isolated from a soil sample from the Talklimaken Desert in Xinjiang Province, China. Strain HR2(T) grew optimally at pH 7.0-8.0 and 30-37 degrees C in the presence of 0-1% (w/v) NaCl. An analysis of 16S rRNA gene sequences revealed that strain HR2(T) fell within the radiation of the genus Pseudomonas, the highest level of similarity being found with respect to Pseudomonas luteola IAM 13000(T) (97.5%); the levels of sequence similarity with respect to other recognized Pseudomonas species were < 96.4%. DNA-DNA hybridization showed that the genetic relatedness between strain HR2(T) and P. luteola IAM 13000(T) was 53.2%. The G + C content of the genomic DNA of strain HR2(T) was 55.2 mol%. The major fatty acids were 18: 1, summed feature 3 and 16:0. The hydroxylated fatty acids 10:0 3-OH, 12:0 3-OH and 12:0 2-OH were also present. The data obtained in this polyphasic study indicated that this isolate represents a novel species of the genus Pseudomonas, for which the name Pseudomonas duriflava sp. nov. is proposed, The type strain is HR2(T) (=KCTC 221129(T) =CGMCC 1.6858(T)).

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The Ag5 proteins are the most abundant and immunogenic proteins in the venom secretory ducts of stinging insects. An antigen 5-like protein (named tabRTS) composed of 221 amino acid residues was purified and characterized from the salivary glands of the horsefly, Tabanus yao (Diptera, Tabanidae). Its cDNA was cloned from the cDNA library of the horsefly's salivary gland. TabRTS containing the SCP domain (Sc7 family of extracellular protein domain) was found in insect antigen 5 proteins. More interestingly, there is an Arg-Thr-Ser (RTS) disintegrin motif at the C-terminus of tabRTS. The RTS motif is positioned in a loop bracketed by cysteine residues as those found in RTS-disintegrins of Crotalidae and Viperidae snake venoms, which act as angiogenesis inhibitors. Endothelial Cell Tube formation assay in vitro and chicken chorioallantoic membrane (CAM) angiogenesis assay in vivo were performed as to investigate the effect of tabRTS on angiogenesis. It was found that tabRTS could significantly inhibit angiogenesis in vitro and in vivo. Anti-alpha(1)beta(1) monoclonal antibody could dose-dependently inhibit the anti-angiogenic activity of tabRTS. This result indicated that tabRTS possibly targets the alpha(1)beta(1) integrin to exert the anti-angiogenic activity as snake venom RTS-/KTS-disintegrins do. The current work revealed the first angiogenesis inhibitor protein containing RTS motif from invertebrates, a possible novel type of RTS-disintegrin. (C) 2009 Elsevier Ltd. All rights reserved.

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通过DEAF Sephadex t-50阴离子交换、超细Sephadex 6100分子筛和反相高效液相CQ色谱层析,从菜花烙铁头蛇毒冻干粉中纯化出一种具有激肤释放酶活性和。纤维蛋白原溶酶活性的丝氨酸蛋白酶,命名为Jerdonase。在12 .5%胶浓度的SD6还原电泳条件下,该酶分子量大约为55 kD,在非还原电泳条件下,分子量大约为53 kD。此酶是一种糖蛋白,含有约35 .8%的中性糖。它的N末端氨基酸序列为IIGGDEENINEHPFLVALYDA,其序列和蛇毒中其他丝氨酸蛋白酶具有非常高的序列相似性。Jerdonase能够催化BAEE、 S-2238和S-2302的水解,其水解活性可被PMSF抑制,但是EDTA对此没有影响。Jerdonase能优先水解人纤维蛋白原的An链,同时伴随有微弱的B[3链水解活性。另外,此酶能够水解牛低分子量的激肤原,释放舒缓激肤。总之,所有的结果表明Jerdonase是一个具有多功能活性的蛇毒丝氨酸蛋白酶。

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通过DEAF Sephadex A-50阴离子交换柱,Sephadex G75分子筛,Resourse Q阴离子交换柱三步层析从湖南产的烙铁头蛇毒中分离、纯化得到一个L-氨基酸氧化酶( T1vf LAO),它由两个非共价的亚基组成,每个亚基的分子量为55 kD。与台湾产的烙铁头蛇毒L-氨基酸氧化酶分子量(70 kD)不同。T1v+ LAO的N末端氨基酸序列是ADNKNPLEECFRETNYEEFLEIAR,与报 道的蜂科的L-氨基酸氧化酶的相似性比眼镜蛇科的要高。T1vf LAO能抑制大肠杆菌、金黄色葡萄球菌和痢疾杆菌的生长,杀死肿瘤细胞以及诱导血小板聚集。这些活性能被过氧化氢酶所抑制,说明T1vf LAO生理学功能主要是通过酶反应产生的过氧化氢( H202)介导的。

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A novel kinin-releasing and fibrin (ogen)olytic enzyme termed jerdonase was purified to homogeneity from the venom of Trimeresurus jerdonii by DEAE Sephadex A-50 anion exchange, Sephadex G-100 (superfine) gel filtration and reverse-phase high performance liquid chromatography (RP-HPLC). Jerdonase migrated as a single band with an approximate molecular weight of 55 kD under the reduced conditions and 53 kD under the non-reduced conditions. The enzyme was a glycoprotein containing 35.8% neutral carbohydrate. The N-terminal amino acid sequence of jerdonase was determined to be IIGGDECNINEHPFLVALYDA, which showed high sequence identity to other snake venom serine proteases. Jerdonase catalyzed the hydrolysis of BAEE, S-2238 and S-2302, which was inhibited by phenymethylsulfonyl fluoride (PMSF), but not affected by ethylenediaminetetraacetic acid (EDTA). Jerdonase preferentially cleaved the Aalpha-chain of human fibrinogen with lower activity towards Bbeta-chain. Moreover, the enzyme hydrolyzed bovine low-molecular-mass kininogen and releasing bradykinin. In conclusion, all results indicated that jerdonase was a multifunctional venom serine protease.