Late Middle Pleistocene deposits at Norton Farm on the West Sussex coastal plain,southern England     

Martin R. Bates  C. Richard Bates  Philip L. Gibbard  Richard I. Macphail  Frederick J. Owen  Simon A. Parfitt  Richard C. Preece  Mark B. Roberts  J. Eric Robinson  John E. Whittaker  Keith N. Wilkinson 《第四纪科学杂志》2000,15(1):61-89

The coastal plain of West Sussex, southern England, is internationally important because of the sequence of discrete high‐sea‐level events preserved at various elevations across it. New evidence is presented from a site at Norton Farm, near Chichester, on the Lower Coastal Plain, where Pleistocene marine sands, fining upwards into silts, occur between 5.3 m and 9.1 m OD. The sequence reflects a regressive tendency at the transition from an interglacial to a cold stage. The marine sands have yielded foraminifera, ostracods and molluscs that indicate a declining marine influence through the sequence, culminating in a tidal mudflat, strongly weathered in places. Cool‐climate foraminifera (including Elphidium clavatum, Cassidulina reniformis and Elphidium albiumbilicatum) and ostracods have been recovered from the marine sands. Some species with an apparent preference for warmer water conditions, however, are also present. Freshwater taxa washed into the terminal marine sediments include some cold climate indicators, such as Pisidium stewarti and P. obtusale lapponicum. Additional evidence for cool climatic conditions during the deposition of the upper part of the marine sequence is provided by the lack of tree taxa in the pollen record and by features of the micromorphology. The marine sediments probably began accumulating during OIS 7, a conclusion based on their elevation, on amino acid ratios from shells, but especially on vertebrate evidence, particularly the presence of a small form of horse, together with a large, distinctive, form of northern vole (Microtus oeconomus). The occurrence of cool climate indicators in these marine sediments may demonstrate a lag between the climatic deterioration and the expected glacio‐eustatic fall in relative sea‐level. This evidence appears to support the conclusions drawn from the study of coral terraces in Barbados. Such a scenario would provide the conditions necessary for the emplacement of the large erratic boulders reported from the Lower Coastal Plain of West Sussex. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

鲈鱼生长催乳素的分离纯化与N-末端序列分析   总被引：1，自引：1，他引：0  

徐斌  张培军  苗宏志  李德尚  森山俊介  川内浩司 《海洋学报》1998,20(2):83-89

生长催乳素(SL)是生长激素/催乳素家族的一种新的脑垂体蛋白质激素,本研究首次从鲈鱼脑垂体中分离得到.鲈鱼脑垂体在碱性条件下,经葡聚糖凝胶(SephadexG-100)过滤和反相高效液相色谱(rpHPLC)分离出纯化的鲈鱼生长催乳素,(sbSL),并与大麻哈鱼生长催乳素(sSL)抗体发生特异性的Western免疫印迹交叉反应证实.SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)分析,发现鲈鱼生长催乳素分别是由分子量为23.2×103和28.4×103u两种形式组成(后者可能是一种糖基化形式).根据Edman降解原理,测得鲈鱼生长催乳素的N-末端16个氨基酸的序列,它与已知鱼类生长催乳素的N-末端序列比较,具有较高的同源性;由此进一步证实,分离纯化得到的鲈鱼生长催乳素是正确的.  相似文献   

Sources and implications of particulate organic matter from a small tropical river—Zuari River,India     

Fernandes Dearlyn  Wu Ying  Shirodkar Prabhaker Vasant  Pradhan Umesh Kumar  Zhang Jing 《海洋学报(英文版)》2020,39(4):18-32

Transitional ecosystems,estuaries and the coastal seas,are distinctively affected by natural and anthropogenic factors.Organic matter(OM)originating from terrestrial sources is exported by rivers and forms a key component of the global biogeochemical cycles.Most previous studies focused on the bulk biochemical and anthropogenic aspects affecting these ecosystems.In the present study,we examined the sources and fate of OM entrained within suspended particulate matter(SPM)of the Zuari River and its estuary,west coast of India.Besides using amino acid(AA)enantiomers(L-and D-forms)as biomarkers,other bulk biochemical parameters viz.particulate organic carbon(POC),δ13C,particulate nitrogen(PN),δ15N and chlorophyll a were analyzed.Surprisingly no significant temporal variations were observed in the parameters analyzed;nonetheless,salinity,POC,δ13C,PN,δ15N,glutamic acid,serine,alanine,tyrosine,leucine and D-aspartic acid exhibited significant spatial variability suggesting source differentiation.The POC content displayed weak temporal variability with low values observed during the post-monsoon season attributed to inputs from mixed sources.Estuarine samples were less depleted than the riverine samples suggesting contributions from marine plankton in addition to contributions from river plankton and terrestrial C3 plants detritus.Labile OM was observed during the monsoon and post-monsoon seasons in the estuarine region.More degraded OM was noticed during the pre-monsoon season.Principal component analysis was used to ascertain the sources and factors influencing OM.Principally five factors were extracted explaining 84.52%of the total variance.The first component accounted for 27.10%of the variance suggesting the dominance of tidal influence whereas,the second component accounted for heterotrophic bacteria and their remnants associated with the particulate matter,contributing primarily to the AA pool.Based on this study we ascertained the role of the estuarine turbidity maximum(ETM)controlling the sources of POM and its implications to small tropical rivers.Thus,changes in temporal and regional settings are more likely to affect the natural biogeochemical cycles of small tropical rivers.  相似文献   

人工养殖军曹鱼亲鱼不同组织氨基酸含量的分析     

黄建盛  陆枝  张健东  陈刚  潘传豪  邓文鑫 《海洋科学》2019,43(4):61-69

为了分析人工养殖军曹鱼(Rachycentron canadum)亲鱼营养储备情况与性腺发育的相关性,作者采用生化的方法,对其肌肉、肝脏及性腺氨基酸含量进行测定。结果表明:(1)雄性亲鱼从Ⅳ期发育到Ⅴ期的过程中,精巢和肝脏牛磺酸含量、精巢总氨基酸含量均呈显著递增(P0.05);肌肉氨基酸总量呈显著下降趋势(P0.05);而肝脏氨基酸总量则无显著性差异(P0.05);(2)雌性亲鱼从Ⅳ期发育到Ⅴ期的过程中,肝脏牛磺酸含量呈显著升高(P0.05);卵巢无显著变化(P0.05);总氨基酸含量差异变化规律与雄性亲鱼相类似。(3)亲鱼总氨基酸含量、必需氨基酸含量在不同组织间存在显著差异(P0.05),表现为肌肉含量最高,其次是性腺,肝脏中最低。肌肉、肝脏及性腺氨基酸组成类似,含量较高的为谷氨酸、天冬氨酸和赖氨酸;含量较低的为组氨酸、蛋氨酸和半胱氨酸。(4)发育处于同期性腺雌雄亲鱼,雄性亲鱼肌肉、性腺必需氨基酸含量和总氨基酸含量显著高于雌性亲鱼(P0.05),而肝脏必需氨基酸含量总和氨基酸含量无显著性变化(P0.05)。  相似文献   

Influence of two different dietary zinc sources in freshwater prawn Macrobrachium rosenbergii post larvae     

THIRUNAVUKKARASU Muralisankar  PERIYAKALI Saravana Bhavan  SUBRAMANIAN Radhakrishnan  PERUMAL Santhanam 《海洋湖沼学报（英文）》2019,(1):290-299

A feeding experiment was conducted to evaluate the ef fects of bulk zinc(B-Zn) and zinc nanoparticles(Zn-NPs) on survival, growth, compositions of amino acid and fatty acid, and nonspeci?c immune responses of the freshwater prawn, Macrobrachium rosenbergii post larvae. The B-Zn(size 10 μm)and Zn-NPs(size 50 nm) were supplemented separately with the basal feeds of M. rosenbergii at 60 mg/kg and feed without supplementation of any Zn source was served as a control. M. rosenbergii were fed these feeds for 90 days and the results showed that signi?cant( P <0.05) improvements in survival, growth, feed intake,speci?c growth rate, essential amino acids, unsaturated fatty acids, nonspeci?c immune responses(total haemocytes and dif ferential haemocytes count) of M. rosenbergii fed with B-Zn and Zn-NPs supplemented feeds when compared to control. Among these Zn sources, Zn-NPs supplemented feeds fed prawns showed signi?cantly( P <0.05) better performance than that of B-Zn and control. Hence, present study suggests that the 60 mg/kg Zn-NPs can be supplemented with basal feeds of M. rosenbergii for regulating better survival and growth.  相似文献   

罗非鱼嗅觉对15种常见氨基酸的RSE探讨   总被引：1，自引：0，他引：1  

柴敏娟  曾建平  于淼 《台湾海峡》2001,20(Z1):63-68

用15种常见氨基酸刺激罗非鱼嗅上皮，观察由此引起的嗅电反应(嗅电图，下简EOG)，研究各种氨基酸对嗅觉的相对有效刺激性(下简RSE).结果表明①15种氨基酸对鱼类嗅觉的RSE顺序如下L-Ser＞L-Met＞L-Lys＞ DL-Met＞L-Arg＞DL-Ser＞L-Cys＞L-Asn＞L-Thr＞L-His＞ L-Ala＞L-Glu＞DL-Pho＞L-Phe＞L-Asp;②在6种鱼类必需氨基酸中，RSE的排列顺序为L-Met＞L-Lys＞L-Arg＞L-Thr＞L-His＞L-Phe;③氨基酸对鱼类嗅觉的RSE与其结构有关.  相似文献   

两种东风螺的营养成分分析与评估   总被引：2，自引：0，他引：2  

许贻斌  沈铭辉  魏永杰  王德祥  柯才焕 《台湾海峡》2008,27(1):26-32

本文对方斑东风螺和波部东风螺自身营养成分进行分析,测定其中的含肉率和腹足肌含有的基本营养成分,分析氨基酸种类及组成和脂肪酸种类及组成,对方斑东风螺和波部东风螺的营养价值进行综合评定以及对比分析.结果表明:方斑东风螺和波部东风螺含肉率分别为48.94%±2.01%和45.12%±2.29%,腹足肌中都含有高达70%左右的蛋白含量和5%左右低含量的脂肪,糖类含量接近10%,氨基酸种类齐全,必需氨基酸相对含量高,必需氨基酸指数在43以上,肉味鲜美,方斑东风螺的EPA和DHA相对含量总和为7.1%,波部东风螺为10.5%,方斑东风螺和波部东风螺的n-3系列不饱和脂肪酸相对含量分别高达6.4%和7.5%,n-6系列分别为13.4%和15.0%,属名贵滋补的海产品.  相似文献   

对叶百部根的无机元素与氨基酸成分分析   总被引：1，自引：0，他引：1  

姜登钊  刘红兵  李国强  管华诗 《中国海洋大学学报(自然科学版)》2008,38(6)

研究无机元素及氨基酸对对叶百部根生物活性的影响,采用电感耦合等离子质谱和氨基酸自动分析仪对其进行检测,共检测27种无机元素和16种氨基酸。结果表明对叶百部中含有Fe,Zn,Mn,Se等多种对人体有益的无机元素和7种人体必需氨基酸,并对无机元素与氨基酸与百部药效的相关性进行探讨。  相似文献   

中国近海表层沉积物中氨基酸组成特征及生物地球化学意义   总被引：6，自引：2，他引：4  

王丽玲  胡建芳  唐建辉 《海洋学报》2009,31(6):161-169

氨基酸是大多数生物体有机氮和有机碳的主要组分,也是近代沿海海洋沉积物有机质的重要组成部分[1]。海洋中生物残骸蛋白质在细胞破裂后,由微生物分泌的胞外酶和生物细胞残留的蛋白酶能将蛋白质水解成氨基酸,部分氨基酸被微生物作为营养物质吸收利用[2],残余蛋白质和氨基酸经过沉降作用进入沉积物,经历生物作用及成岩改造过程,以蛋白质、肽和水解氨基酸等地质聚合物形式存在,大部分与海洋沉积物结合紧密,少数以游离态存在[3]。因此,相对于常量的碳、氮化合物来说氨基酸通常不稳定,是水体颗粒物和沉积物中有机碳、氮循环的主要物质,也是次级生产者的主要营养物质[1]。  相似文献   

Chemical characterization and composition of dissolved organic matter in Jiaozhou Bay   总被引：1，自引：0，他引：1  

张艳萍  杨桂朋  陈岩 《中国海洋湖沼学报》2009,27(4):851-858

Biologically utilizable dissolved organic compounds, including dissolved organic carbon (DOC), dissolved carbohydrates (DCHO) and dissolved free amino acids (DFAA) were analyzed in filtered surface seawater samples collected at 19 stations in Jiaozhou Bay, China, on June 3, 2007. In these samples, concentrations of DOC, dissolved free carbohydrates (DFCHO), dissolved combined carbohydrates (DCCHO), total dissolved carbohydrates (TDCHO) and total dissolved free amino acids (TDFAA) ranged from 141.7 to 191.1 μmol C/L, 1.98 to 18.18 μmol C/L, 5.04 to 24.90 μmol C/L, 14.52 to 30.36 μmol C/L, and 1.83 to 11.89 μmol C/L, respectively. As a major component of the dissolved carbohydrates, the concentrations of DCCHO were about three times higher than those of DFCHO. Three major constituents of the DFAA were threonine (23.0±5.7 mol%), glutamic acid (16.6±3.2 mol%) and arginine (9.1±3.3 mol%). Based on the composition of DFAA, a molar C:N ratio of 3.60±0.75 in DFAA was derived, indicating longer carbon chains in the amino acids. DCCHO (8.1%) was the most abundant fraction of DOM in most samples, followed by DFCHO (4.8%) and TDFAA (2.7%). These DOM concentrations displayed a decreasing trend from the coast to the central region. Significant correlations were found between the DCCHO and DFCHO concentrations (r=-0.724, n=19, P<0.001) and the DCCHO and TDCHO concentrations (r=0.506, n=19, P=0.027).  相似文献