长江口北港和北支浮游动物群落生态学比较研究

浮游动物是河口生态系统的重要组成部分，在食物网中，浮游动物是浮游植物捕食者，对浮游植物有摄食压力，所以控制浮游植物数量的增长。同时，浮游动物还是鱼类的饵料，从而影响渔业资源的数量。长江口是各种经济鱼、虾和蟹的重要产卵场、索饵场和洄游场。长江口各个分汊的分流量的差异较大，导致不同分汊的水文环境明显不同，其中最为明显就是北港和北支水域。然而以往对浮游动物的研究仅限于某一水域，没有对整体水域进行研究，本文选择最具代表性的北港和北支水域，对两水域浮游动物的群落生态特征进行比较研究。 本论文的数据来源于2004年5、8、11月和2005年2月在长江口北港和北支水域4个航次的海洋综合调查资料。通过采用优势度和优势种贡献率等生态学指标，同时结合逐步回归分析，讨论了温、盐与浮游动物总丰度变化的关系。结果表明，就四季而言，浮游动物总丰度和盐度呈显著正相关，和温度负相关。而就单个季节而言，除了5月和2月落潮，总丰度和盐度均呈显著正相关，与温度相关关系不显著。调查水域优势种主要为河口半咸水种或近海种。北港的盐度约为0-5, 表现为长江淡水特征；北支的盐度约为12-28，表现为长江径流和外海水团混合水团的特征。上述优势种的盐度适应和水团分布特征决定了长江口浮游动物分布的时空变化，即盐度较高的水域往往有较高的丰度，北支的总丰度和生物量均大于北港。此外，在长江口口内水域，水温较低的枯水期，浮游动物丰度高于水温较高的丰水期，温度的季节波动，以及主要优势种中华华哲水蚤（Sinocalanus sinensis）对低温环境的适应，是调查水域浮游动物总丰度季节变化的重要因素。 另一方面，本论文通过物种多样性、累积优势度曲线等群落水平的指标和相似性检验分析（ANOSIM），对长江口北港和北支浮游动物群落及其主要优势种的差异，以及主要生态因子对浮游动物群落的影响进行了分析。结果表明，北港主要由潮汐影响的淡水和低盐水组成，北支由中、高盐水组成。春季，北港浮游动物丰度和多样性均低于北支，主要优势种为中华华哲水蚤；北支优势种种数较多，主要是真刺唇角水蚤（Labidocera euchaeta）。夏季，北港和北支的多样性较接近，但是种类组成差别较大，北港以中华华哲水蚤和太平洋纺锤水蚤（Acartia pacifica）为主构成河口半咸水群落，北支以由火腿许水蚤（Schmackeria poplesia）、虫肢歪水蚤（Tortanus vermiculus）和太平洋纺锤水蚤等构成河口低盐群落。秋季，北港的丰度和多样性均低于北支，两个水域的群落差异明显，北港主要由中华华哲水蚤构成，北支由小拟哲水蚤（Paracalanus parvus）、针刺拟哲水蚤（Paracalanus aculeatus）、真刺唇角水蚤和中华哲水蚤（Calanus sinicus）等近岸和外海种组成。冬季，两个水域种数和多样性均较低，群落差别达四季最小，中华华哲水蚤占绝对优势。温度和盐度及其相互作用是决定长江口浮游动物群落特征的最主要因素。其中温度是造成研究水域浮游动物群落季节变化的主要因素，而由径流和外海水之间的消长引起的盐度变化是造成北港和北支浮游动物群落区域变化的决定因素。

Novas fontes de antioxidantes e inibidores de enzimas relevantes para o tratamento da diabetes mellitus tipo 2 e doença de Alzheimer

Dissertação de mest., Engenharia Biológica, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2009

Characterisation of monotreme caseins reveals lineage-specific expansion of an ancestral casein locus in mammals

Using a milk-cell cDNA sequencing approach we characterised milk-protein sequences from two monotreme species, platypus (Ornithorhynchus anatinus) and echidna (Tachyglossus aculeatus) and found a full set of caseins and casein variants. The genomic organisation of the platypus casein locus is compared with other mammalian genomes, including the marsupial opossum and several eutherians. Physical linkage of casein genes has been seen in the casein loci of all mammalian genomes examined and we confirm that this is also observed in platypus. However, we show that a recent duplication of β-casein occurred in the monotreme lineage, as opposed to more ancient duplications of α-casein in the eutherian lineage, while marsupials possess only single copies of α- and β-caseins. Despite this variability, the close proximity of the main α- and β-casein genes in an inverted tail-tail orientation and the relative orientation of the more distant kappa-casein genes are similar in all mammalian genome sequences so far available. Overall, the conservation of the genomic organisation of the caseins indicates the early, pre-monotreme development of the fundamental role of caseins during lactation. In contrast, the lineage-specific gene duplications that have occurred within the casein locus of monotremes and eutherians but not marsupials, which may have lost part of the ancestral casein locus, emphasises the independent selection on milk provision strategies to the young, most likely linked to different developmental strategies. The monotremes therefore provide insight into the ancestral drivers for lactation and how these have adapted in different lineages.

Abundance and biomass of mesozooplankton in the Levantine Basin during the Bilim 2 cruise in April 2008

The Sesame dataset contains mesozooplankton data collected during April 2008 in the Levantine Basin (between 33.20 and 36.50 N latitude and between 30.99 and 31.008 E longitude). Mesozooplankton samples were collected by using a WP-2 closing net with 200 µm mesh size during day hours (07:00-18:00). Samples were taken from 0-50, 50-100, 100-200 m layers at 5 stations in Levantine Basin The dataset includes samples analyzed for mesozooplankton species composition, abundance and total mesozooplankton biomass. Sampling volume was estimated by multiplying the mouth area with the wire length. Sampling biomass was measured by weighing filters and then determined by sampling volume. The samples were sieved sequentially through meshes of 500 and 200 micron to separate the mesozooplankton into size fractions. The entire sample (1/2) or an aliquot of the taxon-specific mesozooplankton abundance and the total abundance of the mesozooplankton were was analyzed under the binocular microscope. Minimum 500 individuals of mesozooplankton were identified and numerated at higher taxonomic level. Taxonomic identification was done at the METU- Institute of Marine Sciences by Alexandra Gubanova,Tuba Terbiyik using the relevant taxonomic literatures. Mesozooplankton abundance and biomass were estimated by Zahit Uysal and Yesim Ak.

Abundance of mesozooplankton in the Cilician Basin during the Bilim 2 cruise in March 2008

The Sesame dataset contains mesozooplankton data collected during March 2008 in the Cilician Basin (between between 35.40'- 36.79 N latitude and 33.19- 36.07 E ). Mesozooplankton samples were collected by using a WP-2 closing net with 200 micron mesh size during day hours (07:00-18:00). Samples were taken in the 0-50, 50-100, 100-200 m layer at 6 stations in the Cilician Basin. The dataset includes samples analyzed for mesozooplankton species composition, abundance and total biomass (Dry weight(mg/m**3)). Taxon-specific mesozooplankton abundance: 1/2 sample or an aliquot was analyzed under the binocular microscope. Copepod species were identified and enumerated; the other mesozooplankters were identified and enumerated at higher taxonomic level (commonly named as mesozooplankton groups). Taxonomic identification was done at the METU-Institute of Marine Sciences by Tuba Terbiyik using the relevant taxonomic literatures. Mesozooplankton total abundance: 1/2 sample or an aliquot was analyzed under the binocular microscope. Copepod species were identified and enumerated; the other mesozooplankters were identified and enumerated at higher taxonomic level (commonly named as mesozooplankton groups). Taxonomic identification was done at the METU-Institute of Marine Sciences using the relevant taxonomic literatures