引水和疏浚工程支配下杭州西湖浮游动物的群落变化

研究了引水和疏浚工程支配下浅水、富营养化杭州西湖浮游动物群落的长期变化,包括浮游动物的优势种类组成、密度及生物量与水环境因子的相关分析.疏浚后的2003年调查中,西湖3个采样站的定量样品中共发现69种浮游动物,其中原生动物26种,轮虫27种,枝角类和桡足类各8种.Ⅰ站浮游动物年平均生物量从1990年的0.186mg/L上升到2003年的0.705mg/L,Ⅱ站和Ⅲ站分别从0.665mg/L和0.740mg/L上升到1.399mg/L和1.195mg/L.浮游动物数量组成中原生动物和轮虫平均占99%,并占78%的生物量.在1980～2003年期间,一些优势种类如砂壳纤毛虫（Tintinnoinea）、针簇多肢轮虫（Polyarthra trigla）和长额象鼻溞（Bosmina longirostris）等显著增加了它们的丰度和优势度;暗小异尾轮虫（Trichocerca pusilla）的优势度在引水后的1990～1995年增加了,但在疏浚后的2003年下降了;而20世纪80年代的一些优势种如毛板壳虫（Coleps hirtus）、螺形龟甲轮虫（Keratella cochelearis）和短尾秀体溞（Diaphanosoma brachyurum）等在3个采样站中失去优势种地位或消失.原生动物和轮虫生物量在营养水平较高的Ⅱ～Ⅲ站明显高于营养水平较低的Ⅰ站;长肢秀体溞（Diaphanosoma leuchtenbergianum）、长额象鼻溞、颈沟基合溞（Bosminopsis deitersi）和汤匙华哲水蚤（Sinocalanus dorrii）在营养水平较低的Ⅰ站具有较大的密度和生物量,而微型裸腹溞（Moina micrura）和粗壮温剑水蚤（Thermocyclops dybowskii）则在营养水平较高的Ⅱ～Ⅲ站具有较大的密度和生物量.西湖各类浮游动物在不同湖区形成不同的分布格局主要由引水水流和水体营养状态差异造成.1990～2003年期间,在采样站变异下,浮游动物中轮虫年平均生物量与水体年平均pH值和叶绿素a含量之间分别有极显著和显著的正相关关系,与水体透明度之间有极显著的负相关关系.引水后的1995年,与轮虫生物量最密切的生态因子是叶绿素a含量,而疏浚后水体碱性环境是影响轮虫生物量最密切的生态因子.     

疏浚后杭州西湖浮游动物群落的变化

2003年1-12月调查了疏浚后杭州两湖(小型、浅水、富营养化湖泊)四个采样站(Ⅰ-Ⅳ)浮游动物群落的变化。研究包括优势种组成、密度和生物量,以及浮游动物生物量与水体叶绿素a、有机物耗氧量、总氮和总磷含量之间的相关分析。疏浚后,Ⅲ-Ⅳ站原生动物第一优势种由似铃壳虫(Tintinnopsis sp.)变为筒壳虫(Tintinnidium sp.);Ⅲ-Ⅳ站轮虫第一优势种由暗小异尾轮虫(Trichocerca pusilla)变为针簇多肢轮虫(Polyarthra trigla);Ⅰ站的长额象鼻溞(Bosmina longirostris)和Ⅲ站的微型裸腹溞(Moina micrura)分别取代了长肢秀体溞(Diaphanosoma leuchtenbergianum)第一优势种的地位;桡足类中,剑水蚤优势种为粗壮温剑水蚤(Thermocyclops dybowskii),哲水蚤优势种为汤匙华哲水蚤(Sinocalanus dorrii)。疏浚后,西湖浮游动物平均密度增加了80.5%,其中原生动物密度增量贡献57.3%。平均生物量增加了49.7%,其中轮虫生物量增量贡献36.5%。西湖浮游动物生物量与水体叶绿素a、有机物耗氧量和总磷含量之间均呈垃著的正相关关系。不同采样站中,以Ⅳ站环境生态因子与浮游动物生物量之间的相关程度最高,其次为Ⅲ站、Ⅰ站和Ⅱ站,水体环境生态因子对浮游动物的影响程度与其优势利演变的体现相一致。在不同浮游动物类群中,枝角类生物量与水质生态因子之间的相关程度最高,其次为轮虫、桡足类和原生动物。     

新疆乌伦古湖浮游甲壳动物的季节演替及与环境因子的关系

通过2006年11月至2008年8月2周年8个季度的野外采样调查和室内分析,研究了新疆乌伦古湖浮游甲壳动物的季节演替格局及其与环境因子的相关性。结果表明,枝角类和桡足类的总种类数为25种,其中枝角类6种,桡足类19种。枝角类Shannon-Wiener指数2007年夏季和2008年夏季较高,2007年冬季最低;Pielou 指数2006年冬季最高;桡足类Shannon-wiener指数和Pielou指数除冬季较低外,其余三季较高。方差分析结果表明枝角类和无节幼体的密度与生物量呈现出显著的季节变动格局,其中,枝角类密度和生物量在夏秋季形成单一高峰,最大值出现在2007年夏,最大密度和生物量分别为2.12个/L和0.062 mg/L,而无节幼体密度和生物量形成春秋双高峰,其最大值出现在2007年春,密度和生物量分别为5.14个/L和0.015 mg/L,桡足类密度和生物量季节变化不明显。优势种的季节演替方面,象鼻溞和模式有爪猛水蚤全年形成优势,其他枝角类、哲水蚤和剑水蚤不同季节的优势种各异。经典范对应分析(CCA)结果表明,长刺溞等与水体中的pH值、SD呈正相关,与浮游植物生物量呈负相关;长额象鼻溞等与水深呈正相关,无节幼体等与水温也呈正相关性。     

大沙河水库浮游甲壳类动物群落特征

于2010 年1 月至12 月对广东大沙河水库的三个典型水域(河流区、过渡区和湖泊区)进行逐月采样, 共检出浮游甲壳类动物15 种, 其中枝角类10 种, 桡足类5 种, 多为广温性和嗜暖性种类。全年出现的种类有: 象鼻溞(Bosmina spp.), 微型裸腹溞(Moina micrura)、角突网纹溞(Ceriodaphnia cornuta)、温中剑水蚤(Mesocyclops thermocyclopoides)、博平近剑水蚤(Tropocyclops bopingi)和右突新镖水蚤(Neodiaptomus schmackeri)。在丰度上无节幼体占优势, 枝角类的优势种以小型种类(象鼻溞、微型裸腹溞、角突网纹溞)为主, 枯水期的优势种为象鼻溞, 在丰水期优势种为角突网纹溞, 形成象鼻溞(1-4 月)-角突网纹溞(5-9 月)-象鼻溞(10-12 月)的季节更替结构。浮游甲壳类总丰度和总生物量的变化范围分别是58.73-231.89 ind·L–1 和224.36-986.03 μg·L–1, 季节波动都比较明显, 丰水期浮游甲壳类的丰度和生物量明显高于枯水期; 高峰值均出现在捕食压力相对较低而生长期开始的丰水早期(4 月)。浮游甲壳类的丰度和生物量在三个采样水域之间的时空差异性不明显, 群落结构主要受水库的水温、营养水平和浮游植物种类组成的影响。     

苏州工业园区水体浮游甲壳动物群落特征及其与环境因子的关系

于2012年6月至2013年5月,对苏州工业园区湖泊和河流水体的浮游甲壳动物组成及群落结构进行了研究,分析了浮游甲壳动物的密度和生物量的年度变化,探讨其分布与水体理化因子间的关系.结果表明：园区水体有枝角类6科12属24种,桡足类7科13属18种,其中短尾秀体溞、长额象鼻溞、汤匙华哲水蚤及近邻剑水蚤在不同水体中不同季节均为优势种.在湖泊水体和河流水体中,浮游甲壳动物的密度和生物量表现为夏、秋季较高,冬、春季较低,且在夏、秋季分别具有2个峰值.枝角类平均密度和生物量在河流水体中均高于湖泊水体,两者间均具有显著差异;桡足类的平均密度在河流水体和湖泊水体间差异不显著,而平均生物量要显著高于湖泊水体.湖泊水体和河流水体在溶解氧、pH、透明度、总溶解固体、盐度、总磷、总氮及铵氮含量上均存在显著差异;冗余分析表明无论是湖泊水体还是河流水体,多数浮游甲壳动物的分布与水温、盐度、化学需氧量(COD_Mn)和总磷等指数呈正相关,只有枝角类中的溞属、船卵溞属种类的分布与水体溶解氧、pH值及透明度呈正相关.     

南京玄武湖微型裸腹溞和短尾秀体溞的种群变动和生产量

本文报道了南京玄武湖微型裸腹溞和短尾秀体溞的种群变动和生产量的研究结果,并分析了影响它们的生态因子。计算了种群的瞬时出生率(b),瞬时增长率(r)和瞬时死亡率(d)。观察了微型裸腹溞怀卵量的季节变化。微型裸腹溞生长季节平均生物量为87.51μg/L(干重),生产量为8292.36μg/L(干重),P/B系数为94.76;短尾秀体溞生长季节平均生物量为9.58μg/L(干重),生产量为480.02μg/L(干重),P/B系数为50.52。     

军山湖、青山湖和瑶湖春夏季节浮游甲壳动物的群落结构及其与环境因子的关系

于2016年3—8月,研究了江西省南昌市军山湖、青山湖和瑶湖的春夏季节浮游甲壳动物的群落结构。结果表明:3个湖泊共鉴定出浮游甲壳动物14种,其中枝角类8种、桡足类6种;军山湖、青山湖和瑶湖的浮游甲壳动物密度变动范围分别为0.8~24.9、0.3~18.7和5.9~47.9 ind·L-1;瑶湖的浮游甲壳动物密度显著大于军山湖(P=0.003)和青山湖(P0.001);秀体溞、微型裸腹溞和象鼻溞等富营养化种类是3个湖泊浮游甲壳动物的夏季优势种,而盔形溞是军山湖的春季优势种。冗余分析表明,水温、叶绿素a和pH是决定3个湖泊浮游甲壳动物群落结构的相同环境因子,位于城市近郊的青山湖和瑶湖的浮游甲壳动物群落结构还与氮、磷等营养盐密切相关。     

赣江下游及其支流浮游甲壳动物的群落结构

2009年6月、11月和2010年4月对赣江下游浮游甲壳动物的群落结构和时空变化进行研究.共记录浮游甲壳动物21种,其中枝角类14种、桡足类7种.脆弱象鼻溞Bosmina fatalis、微型裸腹溞Moina micrura和中剑水蚤Mesocyclops sp.为优势种.赣江下游干流浮游甲壳动物的最大平均密度和生物量(11.1ind.·L^-1和0.127mg·L^-1)均出现在6月,最小值(1.59ind.·L^-1和0.01mg·L^-1)均出现在4月.袁河支流的枝角类和桡足类密度在6月(4.97±13.28ind.·L^-1和2.07±4.85ind.·L^-1)和11月(2.07±5.21ind.·L^-1和2.24±5.22ind.·L^-1)高于赣江下游干流和锦江支流.香农-威纳指数(H')和马加利夫指数(d)表明赣江下游及其支流水质为中度污染或重污染.水温和小型浮游植物生物量是影响赣江下游浮游甲壳动物密度时空变化的重要因素.     

焦岗湖浮游甲壳动物群落结构的季节动态

2013年10月至2014年7月分季节对焦岗湖浮游甲壳动物群落结构动态进行调查,并探讨了影响浮游甲壳动物群落结构的环境因子。结果表明:焦岗湖共记录浮游甲壳动物17种,其中枝角类8属11种,桡足类5属6种;全湖枝角类的优势种为秀体溞(Diaphanosoma sp.)、矩形尖额溞(Alona rectangula)和脆弱象鼻溞(Bosmina fatalis),桡足类的优势种为跨立小剑水蚤(Microcyclops vaticans)和透明温剑水蚤(Thermocyclops hyalinus);浮游甲壳动物的密度和生物量呈现明显的季节变化,春、夏季较高,秋、冬季较低,年平均密度和年平均生物量分别为(196.30±313.75)ind·L-1和(1.80±3.18)mg·L-1;枝角类的密度和生物量的最高值分别出现在夏季[(28.53±55.91)ind·L-1]和春季[(0.61±0.70)mg·L-1],桡足类的密度和生物量的最高值均出现在夏季,分别为(31.47±51.09)ind·L-1和(2.82±4.58)mg·L-1;全湖浮游甲壳动物群落Shannon多样性指数的年平均值为1.07±0.81,最大值(1.74±0.46)出现在春季;典范对应分析(CCA)表明,与焦岗湖浮游甲壳动物群落结构的季节动态变化相关的重要环境因子为水温、p H、溶解氧、浮游植物生物量、营养盐等。     

直额裸腹潘对海水盐度的适应能力

枝角类广布于淡水水体且是幼鱼的主要食料,仅有少数种类分布于海水。海产枝角类繁殖力低又不易大量培养,作为海水动物养殖的活饵料意义不大。为了探究利用淡水枝角类供作海产动物人工养殖的活饵料的可能性,我们对不同产地的直额裸腹溞(Moina rectirostris)对盐度的适应能力作了试验研究结果如下。裸腹溞是淡水枝角类中繁殖力最强的一个属,直额裸腹溞在我国干旱地区半咸水水体很常见,曾经在盐度5.5‰的达里湖中形成优势种群,从培养海产动物活饵料的来源,应是很     

Pollen,ovules, and pollination in pea: Success,failure, and resilience in heat

Field pea (Pisum sativum), a major grain legume crop, is autogamous and adapted to temperate climates. The objectives of this study were to investigate effects of high temperature stress on stamen chemical composition, anther dehiscence, pollen viability, pollen interactions with pistil and ovules, and ovule growth and viability. Two cultivars (“CDC Golden” and “CDC Sage”) were exposed to 24/18°C (day/night) continually or to 35/18°C for 4 or 7 days. Heat stress altered stamen chemical composition, with lipid composition of “CDC Sage” being more stable compared with “CDC Golden.” Heat stress reduced pollen viability and the proportion of ovules that received a pollen tube. After 4 days at 35°C, pollen viability in flower buds decreased in “CDC Golden,” but not in “CDC Sage.” After 7 days, partial to full failure of anthers to dehisce resulted in subnormal pollen loads on stigmas. Although growth (ovule size) of fertilized ovules was stimulated by 35°C, heat stress tended to decrease ovule viability. Pollen appears susceptible to stress, but not many grains are needed for successful fertilization. Ovule fertilization and embryos are less susceptible to heat, but further research is warranted to link the exact degree of resilience to stress intensity.     

Love, careers, and heights in France, 2001

Short men are less likely to be married or live in a permanent relationship than their taller counterparts. This pattern is not due to their social status. While blue-collar workers are shorter on average than managers, the effects of height on finding a mate are similar in the two social groups. Being tall is also economically advantageous for men. With identical educational attainment levels, tall men have better careers than short men as they are given greater supervisory responsibilities. In making a commitment, some women might take height into account as an anticipated indicator of future resources of the household. Choice of partner is also influenced by social norms--i.e., partners should be physically well-matched--which is more difficult for shorter men.     

Distribution of N,P, K,Ca, Mg,S, Zn,Fe, Mn and Cu in groundnut

Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.     

Correlations of calcium accumulations in arteries, veins, cartilages, ligaments, and bones in single humans

To show the relationships of calcium accumulation in the thoracic aorta to the other tissues, calcium contents were determined with a microwave-induced plasma-atomic emission spectrometer on arteries, veins, cartilages, ligaments, and bones. These tissues were resected from 18 individuals, consisting of 11 men and 7 women who died in the age range 59–91 yr. As thoracic and abdominal aortas are routinely used for radiographic examination of arterial calcification, they appear to be standard tissues of the calcium accumulation. The calcium accumulations were determined in the femoral artery, the superior and inferior venae cavae, the internal jugular vein, cartilages of the articular disk of the temporomandibular joint and the intervertebral disk, both the ligaments of the anterior cruciate ligament and the ligamentum capitis femoris, and the calcaneus, in contrast with the thoracic aorta. As calcium increased in the thoracic aorta, it increased in the femoral artery, the articular disk of the temporomandibular joint, the intervertebral disk, both ligaments of the anterior cruciate ligament, and the ligamentum capitis femoris, but it did not increase in veins, such as the superior and inferior venae cavae and the internal jugular vein. In contrast, it decreased in the calcaneus.     

Seroepidemiology of human parechovirus types 1, 3, and 6 in Yamagata,Japan, in 2014

To clarify the seroepidemiology of human parechovirus type 1 (HPeV1), 3 and 6, neutralizing antibodies (NT Abs) were measured in 214 serum specimens collected in 2014 in Yamagata, Japan. The seroprevalence against HPeV1 was 100% in all age groups, while that against HPeV3 and HPeV6 was 79.4% and 66.8%, respectively, overall. The geometric mean titers of NT Abs against HPeV1, 3 and 6 were 755.2, 255.0 and 55.9, respectively, overall. Our findings indicate that HPeV1 is the most prevalent HPeV circulating in Yamagata, followed by HPeV3 and HPeV6.     

Diet,intestinal morphology,and nitrogen assimilation efficiency in the damselfish,Stegastes lividus,in Guam

Synopsis Analysis of stomach contents of Stegastes lividus revealed a shift from omnivory in juveniles to herbivory in adults. Red algae, primarily Polysiphonia spp., Gelidiopsis intricata and Ceramium spp., formed the bulk of the diet in all size classes. Foraminifera and small crustaceans were of particular importance in the diet of juveniles. Net nitrogen assimilation efficiency of field-fed S. lividus was approximately 61%, and did not vary with fish size. The net assimilation efficiencies of fish fed on Enteromorpha in the laboratory ranged from size-class means of 36–79% for nitrogen and from 29–72% for total organic material, and increased from juveniles to adults. Apparently, juveniles compensate for a lower efficiency in assimilating plant food by including a higher percentage of animal material in their natural diets. The ratios of intestine length to standard length (IL/SL) and to intestine diameter (IL/ID) increased rapidly in juveniles and leveled off in adults. The retention time for ingested food items may only be about one-half as long in juveniles as in adults. The combination of observed IL/ID ratios and estimated retention times proved most valuable in the interpretation of ontogenetic changes in feeding habits and assimilation efficiency.     

Magnesium,calcium, copper,and zinc in meals

Meals of 12 diets were prepared from conventional foods with precautions against contamination by metallic elements because of epidemiologic associations between ischemic heart disease and the metabolism of magnesium, calcium, copper, and zinc. Magnesium, calcium, copper, and zinc were measured by atomic absorption spectrometry with satisfactory accuracy and precision. The mean daily amount of copper in the diets was less than the apparent adult requirement. Mean amounts of magnesium and zinc were close to apparent requirements; however, adults consuming amounts less than one standard deviation below these means may be depleting body stores and be at risk of pathology. Magnesium and copper were highly correlated (r=0.849,P=0.0001) in meals. This and other significant correlations probably will prevent the relationships of these elements to ischemic heart disease from being elucidated by epidemiology. Metabolic experiments will be necessary to differentiate among several hypotheses.