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Correlation of personality with individual reproductive success in shrub-nesting birds depends on their life history style
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作者 Jianchuan Li Wen Zhang +5 位作者 Ningning Sun Yujie Wang Lifang Gao Ran Feng Liqing Fan Bo Du 《Avian Research》 SCIE CSCD 2024年第1期42-49,共8页
Two questions in the research of animal personality—whether there is a correlation between a personality trait and individual reproductive success,and what is the genetic basis underlying a personality trait—remain ... Two questions in the research of animal personality—whether there is a correlation between a personality trait and individual reproductive success,and what is the genetic basis underlying a personality trait—remain unresolved.We addressed these two questions in three shrub-nesting birds,the Azure-winged Magpie(Cyanopica cyanus,AM),White-collared Blackbird(Turdus albocinctus,WB),and Brown-cheeked Laughingthrush(Trochalopteron henrici,BL).The personality type of an individual was first identified according to its response to a territorial intruder.Then,we compared the fleeing distance,breeding parameters,and differential expressed genes(DEGs) in the brain transcriptome between bold and shy breeders.In the three species,bold breeders exhibited more aggressiveness towards an intruder of their territory than did shy breeders.The reproductive success of bold breeders was significantly higher than that of shy breeders in AM but not in WB and BL.The three species shared one DEG,crabp1,which was up-regulated in bold relative to in shy individuals.By regulating the expression of corticotropin-releasing hormone,higher crabp1 gene expression can decrease cellular response to retinoic acid.Therefore,bold individuals are insensitive to external stresses and able to exhibit more aggressiveness to intruders than their shier counterparts.Aggressiveness is beneficial to bold individuals in AM but not in WB and BL because the former could evoke neighbors to make the same response of defending against intruders but the latter could not.Although a personality trait may have the same genetic basis across species,its correlation with reproductive success depends largely on the life history style of a species. 展开更多
关键词 BOLDNESS life history style PERSONALITY Reproductive success Transcriptome analysis
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A preliminary study on life history of marine red alga Stylonema alsidii(Zandardini)Drew f.ramosum Zheng et Li
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作者 Bingxin HUANG Yao ZHANG +4 位作者 Yue CHU Youxuan GUO Junxia LIANG Jianan QIN Lanping DING 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第3期915-922,共8页
Stylonema alsidii(Zandardini)Drew f.ramosum Zheng et Li is a common species in the genus Stylonema,but there are limited reports on morphological taxonomy and a lack of studies on life history and the regulation of ea... Stylonema alsidii(Zandardini)Drew f.ramosum Zheng et Li is a common species in the genus Stylonema,but there are limited reports on morphological taxonomy and a lack of studies on life history and the regulation of early development.The early development,discoid formation,and erect thallus growth of Stylonema alsidii f.ramosum were observed under laboratory conditions.In addition,the influence of main environmental factors such as temperature and light intensity on its development was briefly studied,and various stages of its life history were observed.The result shows:(1)there are two reproductive modes:asexual reproduction and sexual reproduction;(2)the morphology of this species varies in different degrees under laboratory culture conditions;(3)sexual reproduction and asexual reproduction can coexist under suitable conditions.Five pathways of life history were inferred from experimental phenomena.Mature sporophytes form mature gametophytes by producing initially isolated or initially attached monospore,and mature gametophytes form mature sporophytes by fertilization of eggs and sperms.The sexual and asexual reproduction processes of Stylonema alsidii f.ramosum were reported for the first time,and this is also the first report on sexual reproduction in the genus Stylonema. 展开更多
关键词 Stylonema alsidii(Zandardini)Drew f.ramosum Zheng et Li life history environmental factor asexual reproduction sexual reproduction
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教育生活史视角下师范生眼中的“好老师”研究--基于教育自传的Nvivo11质性分析
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作者 裴长安 李卓 《兵团教育学院学报》 2024年第1期59-64,共6页
研究采用教育生活史视角,以S大学95位师范生的教育自传为研究对象,借助Nvivo11软件对研究资料进行三级编码与分析,旨在探究师范生眼中“好老师”的形象特点。通过对编码结果进行观察,发现师范生眼中“好老师”特征的优先等级的顺序排列... 研究采用教育生活史视角,以S大学95位师范生的教育自传为研究对象,借助Nvivo11软件对研究资料进行三级编码与分析,旨在探究师范生眼中“好老师”的形象特点。通过对编码结果进行观察,发现师范生眼中“好老师”特征的优先等级的顺序排列为道德素养、能力素养、个人特质和知识素养。师范生撰写教育自传不仅是对个人成长的回顾与反思,更是教育研究的一份宝贵资料,为教育机构和学校的改革与发展提供重要的方向指引。 展开更多
关键词 教育生活史 师范生 “好老师” 教育自传
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Re-identifying Grateloupia yangjiangensis(Rhodophyta, Halymeniaceae) based on morphological observations, life history and rbcL sequence analyses 被引量:10
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作者 WANG Hongwei GUO Shaoru +3 位作者 ZHANG Xiaoming ZHAO Dan ZHANG Wen LUAN Rixiao 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第4期77-84,共8页
On the basis of morphological observations, life history and molecular phylogeny, Grateloupia yangjiangensis, which is similar to G. filicina, G. orientalis, G. catenata, and G. ramosissima in appearance, was re-exami... On the basis of morphological observations, life history and molecular phylogeny, Grateloupia yangjiangensis, which is similar to G. filicina, G. orientalis, G. catenata, and G. ramosissima in appearance, was re-examined. The results are as follows:(1) the auxiliary-cell ampullae of G. yangjiangensis were of Grateloupia type, thalli was fleshy and gelatinous in texture, and the erect axes were compressed; the cortex was 0.25–0.30 mm thick, consisting of five to seven outer layers, and there were five inner layers of triangular or stellate cells;(2) there was no filamentous stage in the development of the carpospores;(3) the ribulose-1,5-bisphosphate carboxylase/oxygenase gene(rbcL) sequence of four G. yangjiangensis examined showed that there was no intergeneric divergence among them, and for the phylogenetic tree, four sequences of G. yangjiangensis formed a single monophyletic subclade within the large Grateloupia clade of Halymeniaceae. In conclusion, G. yangjiangensis was a single species within the genus Grateloupia. This research provided criterion for identification and cultivation of G. yangjiangensis. 展开更多
关键词 Grateloupia yangjiangensis HALYMENIACEAE RHODOPHYTA morphological observations life history RBCL
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Life-history dependent relationships between plasma alkaline phosphatase activity and body condition in male Eurasian Tree Sparrows 被引量:1
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作者 Yuliang Zhao Lingjuan Gong +3 位作者 Baohua Zhao Xuebin Gao Yuefeng Wu Dongming Li 《Avian Research》 CSCD 2017年第3期163-167,共5页
Background: In temperate-breeding birds, individuals must adjust their physiological states from one life-history stage to another in response to changing conditions to maximize ecological fitness. Previous evidences ... Background: In temperate-breeding birds, individuals must adjust their physiological states from one life-history stage to another in response to changing conditions to maximize ecological fitness. Previous evidences have shown that body mass, size-corrected mass(SCM), and hematocrit(Hct) could be used as estimates of the energetic state of individuals to illustrate life-history trade-offs and individual quality in field physiology. Plasma alkaline phosphatase(ALP) plays critical roles in regulating the metabolism of energy but very limited information is known on its link with body mass or Hct.Methods: We determined the changes of plasma ALP levels in both early breeding and wintering stages of male Eurasian Tree Sparrows(Passer montanus), and examined the relationships between ALP and body mass, SCM, and Hct of the birds.Results: Our study showed that(1) in male Eurasian Tree Sparrows, body mass did not vary with life-history stage but plasma ALP activity significantly increased in the wintering stage compared to the breeding stage;(2) ALP activity was not correlated with individual body mass but was positively correlated with individual SCM and Hct. Such positive correlations, however, only occurred in the wintering but not in the breeding stages.Conclusions: Our results suggest that plasma ALP activities in free-living birds can be used as one of the indicators o body condition or nutritional status for analyzing individual variation in the wintering but not in the breeding stages. The life-history dependent relationships between plasma ALP activity and body condition may contribute to our better understanding of the trade-off between individual survival and reproduction in free-living animals. 展开更多
关键词 Alkaline phosphatase Size-corrected mass HEMATOCRIT Passer montanus life history Trade-off
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“翠色真红”--生活史视野下宋女生活服色考论
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作者 银连桐 王小松 《丝绸》 CAS CSCD 北大核心 2024年第4期105-113,共9页
长期以来,宋女日常服色的观点抵牾杂驳,聚讼纷纭。文章通过梳理过往研究,以社会生活史为基本视野,以二重证据法结合传世绘画、出土实物、札记、诗文等探讨宋代女性生活服饰色彩的总体情状。文章认为宋代女装色彩浓艳绚烂和质朴淡雅两种... 长期以来,宋女日常服色的观点抵牾杂驳,聚讼纷纭。文章通过梳理过往研究,以社会生活史为基本视野,以二重证据法结合传世绘画、出土实物、札记、诗文等探讨宋代女性生活服饰色彩的总体情状。文章认为宋代女装色彩浓艳绚烂和质朴淡雅两种格调并峙。文章从皮尔斯“规约符号”的观点出发,认为色彩作为规约符号在政治场合之外、日常生活里只在男性群体中发挥作用,在女性那里并没有具体明晰的规范。宋代女性服色的研究通常以传世绘画为端绪。然而,大多数为文人主持并收藏流转的绘画并不能完整反映时装服色系统的真实情况,政治理念与生活实践之间存在张力与裂隙。宋代女性生活色彩丰富多变。色彩研究必须认识到历史的参与者,即“人”的复杂性,并从日常生活的多重视角出发,才能在丰富纷杂的历史材料中括撮出女服色彩的具体写真。 展开更多
关键词 色彩 皮尔斯符号学 宋代 女子服饰 社会规范 生活史
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Opportunistic-tended life history traits of Siniperca kneri in the Three Gorges Reservoir,China: potential responses to impoundment
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作者 ZHAO Shasha CHENG Fei +2 位作者 HOU Gang HU Zhengyu XIE Songguang 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2019年第2期694-705,共12页
Reservoir impoundment changes original fluvial habitats into lentic environments. Fish species adapted to lentic habitats may take the advantage of such habitat changes and show typical life history traits might facil... Reservoir impoundment changes original fluvial habitats into lentic environments. Fish species adapted to lentic habitats may take the advantage of such habitat changes and show typical life history traits might facilitate the population increase. Siniperca kneri rarely occurred in fishery landing in the Three Gorges Reservoir (TGR) area before its impoundment in 2003, but it is now a dominant species. In this study, a total of 438 females of S . kneri were collected monthly during September 2012 through January 2014 using gill nets in the TGR. The age, growth, and reproductive biology were then investigated, and compared with other S . kneri populations. The standard length at age 1 was 149.9 mm in the TGR, which is larger than the three compared populations (i.e., Sandaohe Reservoir, Xinfengjiang Reservoir, and North River), but smaller than one (the Guishi Reservoir). The youngest mature female in the TGR was age 1, which is younger than that of the two compared populations (i.e., Xinfengjiang Reservoir and the North River). The relative fecundity in the TGR was 140 eggs/g, which is higher than that of the only available compared population (Xinfengjiang Reservoir, 96 eggs/g). Our results demonstrated that S . kneri in the TGR tended to have faster growth in the first year, a younger age at first maturation, and higher reproductive eff ort. We suggest that such opportunistic-tended life history traits might facilitate rapid increase of the population. 展开更多
关键词 SINIPERCA kneri life history TRAITS OPPORTUNISTIC growth REPRODUCTION COLONIZATION
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Isoenergetic-practical and semi-purified diets for protein requirement determination in Hermetia illucens larvae:consequences on life history traits
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作者 Sara Bellezza Oddon Ilaria Biasato Laura Gasco 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2022年第3期897-906,共10页
Background:Black soldier fly(BSF)is one of the most promising species for the intensive breeding of insects given its adaptability and its efficiency in the conversion of waste.To maximize the production and use waste... Background:Black soldier fly(BSF)is one of the most promising species for the intensive breeding of insects given its adaptability and its efficiency in the conversion of waste.To maximize the production and use waste as substrates,it is essential to determine the larvae nutritional requirements.The study aims to evaluate the effects of5 practical,semi-purified and isoenergetic diets(PSPID)with increasing protein levels(10%,CP10;14%,CP14;16%,CP16;19%,CP19)on BSF life history traits.A total of 2000 six-day-old larvae were weighed and divided into groups of 100(4 replicates/treatment[PSPID and Gainesville diet(GA)used as environmental control]).In larva-prepupa stage,sampling was carried out on 30 individuals/replicate,while in prepupa-adult stage on 35.Results:In the whole larval stage,the CP16 treatment performed better when compared to the other groups.At18 days old,the CP14 treatment showed a higher weight than the CP19(P<0.01),while the CP10 and CP16weights were intermediate.On the contrary,the CP10 prepupae weight was higher than the CP19(P<0.01).The CP10 and CP14 pupae performed better in terms of weight when compared to the others(P<0.01).The dietary treatments did not affect the adult parameters.The sex significantly influenced both the exuvia weight,which was the greatest in females(P<0.001),and the fly lifespan,longest in males(P<0.05).Fly lifespan was also influenced by the interaction between treatment and sex,with the CP19 females showing a longer life than the others(P<0.05).Conclusions:In conclusion,the optimal protein level considering the whole larval stage is 16%on dry matter(DM).At 18 days old,looking at the size intended for the meal production,it can be considered 14%on DM.The result obtained on adult emergence in PSPID may not be attributable to the protein content.Further researches on macronutrients requirements determination have to be conducted to evaluate the substrates composition effects on BSF life history traits. 展开更多
关键词 Hermetia illucens life history traits Nutritional requirements Semi-purified
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Effects of life-history components on population dynamics of the rare endangered plant <i>Davidia involucrata</i> 被引量:1
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作者 Haimei You Yanhong Liu Kazue Fujiwara 《Natural Science》 2013年第1期62-70,共9页
In order to estimate the most effect stage and process on population growth and effective conserve the rare endangered plant Davidia involucrata, we analyzed the dynamics and the contributions of life-history componen... In order to estimate the most effect stage and process on population growth and effective conserve the rare endangered plant Davidia involucrata, we analyzed the dynamics and the contributions of life-history components on population dynamics based on Lefkovitch matrix model and sensitivity analysis. The life cycle of Davidia involucrata was divided into six stages (seed, seedling, juvenile, immature, early adult and late adult) based on the species characteristics and published literature data, the survival rates in each life-history stage were simulated using a static life table, and the fecundity of each stage was determined according to sample information. The results showed that the structure of the observed population was not ideal, and the numbers of seedlings and coppice shoots was similar. The population growth rate was influenced largely by individual growth process, and asexual reproduction made a larger contribution to population growth than sexual reproduction. However, sexual reproduction was more important than asexual reproduction, because most asexual reproducing individuals (the coppice shoots) were derived mainly from human destruction (e.g. felling trees). The most important stage was stage V (late adult), associated with seed production and germination. Therefore, conservation of Davidia involucrata populations should focus on stage V and sexual reproduction, in order to improve the seed production and germination rate, and to promote population stability and development. 展开更多
关键词 Davidia INVOLUCRATA Lefkovitch Matrix model life-history Stage Population ECOLOGY Sensitivity Analysis
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An aqueous BiI_(3)-Zn battery with dual mechanisms of Zn^(2+)(de)intercalation and I^(-)/I_(2)redox
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作者 Qi Deng Fangzhong Liu +3 位作者 Xiongwei Wu Changzhu Li Weibin Zhou Bei Long 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期670-678,I0014,共10页
The development of aqueous battery with dual mechanisms is now arousing more and more interest.The dual mechanisms of Zn^(2+)(de)intercalation and I^(-)/I_(2)redox bring unexpected effects.Herein,differing from previo... The development of aqueous battery with dual mechanisms is now arousing more and more interest.The dual mechanisms of Zn^(2+)(de)intercalation and I^(-)/I_(2)redox bring unexpected effects.Herein,differing from previous studies using Zn I_(2)additive,this work designs an aqueous Bi I_(3)-Zn battery with selfsupplied I^(-).Ex situ tests reveal the conversion of Bi I_(3)into Bi(discharge)and Bi OI(charge)at the 1st cycle and the dissolved I^(-)in electrolyte.The active I^(-)species enhances the specific capacity and discharge medium voltage of electrode as well as improves the generation of Zn dendrite and by-product.Furthermore,the porous hard carbon is introduced to enhance the electronic/ionic conductivity and adsorb iodine species,proven by experimental and theoretical studies.Accordingly,the well-designed Bi I_(3)-Zn battery delivers a high reversible capacity of 182 m A h g^(-1)at 0.2 A g^(-1),an excellent rate capability with 88 m A h g^(-1)at 10 A g^(-1),and an impressive cyclability with 63%capacity retention over 20 K cycles at 10 A g^(-1).An excellent electrochemical performance is obtained even at a high mass loading of 6 mg cm^(-2).Moreover,a flexible quasi-solid-state Bi I_(3)-Zn battery exhibits satisfactory battery performances.This work provides a new idea for designing high-performance aqueous battery with dual mechanisms. 展开更多
关键词 Aqueous BiI_(3)-Zn battery Dual mechanisms I^(-)-induced uniform zinc deposition Ultralong cyclic life Flexible quasi-solid-state battery
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Life Cycle-Stages in History of Tourism in the Republic of Macedonia
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作者 Nikola V. Dimitrov 《Journal of Tourism and Hospitality Management》 2017年第5期173-188,共16页
The aim of this paper is to explore the historical development of tourism through identified stages of the life cycle (TALC) model. Many of the major destinations in the world have a far longer history and go throug... The aim of this paper is to explore the historical development of tourism through identified stages of the life cycle (TALC) model. Many of the major destinations in the world have a far longer history and go through various successive cycles with different phases. In this article, we present the case of Macedonia, as a Balkan mainland tourist destination. The analysis is based on primary and secondary data sources for an extended period. The article shows the life cycle of the tourist destination in combination and adaptation of new TALC model that matches regulation theories and the Ford paradigm of global model for tourism development of mass production and consumption. Finally, the paper suggests and recommends practical advice aimed at motivating key players in the formation of economic policy for tourism development. 展开更多
关键词 life cycle TALC model history of tourism regulation theories Ford paradigm MACEDONIA
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Historical retrospects and evolutionary characteristics of paleogenomic science and technology
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作者 Qiang-Yu Xiang Kun-Lan Zuo Huan Liu 《History & Philosophy of Medicine》 2024年第2期14-22,共9页
Paleogenomics is a discipline in which the extraction and analysis of DNA from ancient biological remains are studied to understand the evolutionary history of past organisms.Research on this topic has revealed the ev... Paleogenomics is a discipline in which the extraction and analysis of DNA from ancient biological remains are studied to understand the evolutionary history of past organisms.Research on this topic has revealed the evolutionary history of humans and other species,traced human migrations and genetic changes,and investigated ancient diseases and environmental influences due to its uniqueness.This paper reviews the scientific and technological history of the development of paleogenomics,including the molecular cloning era,the polymerase chain reaction(PCR)technique era,the genomics era,and the bio-data analysis era.This field explores the key technological development processes and effects of significant scientific discoveries,ranging from gene cloning technology and sequencing technology to breakthroughs and applications in big data analysis,addressing challenges such as sample contamination and trace collection analysis in paleogenomics research. 展开更多
关键词 paleogenomics history of science and technology key technologies life evolution
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Textual research on Xu Chunfu's life
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作者 Ju-Yi Wang Hui Huang +1 位作者 Lin-Na Wu Wen-Qing Wu 《History & Philosophy of Medicine》 2024年第3期9-15,共7页
Xu Chunfu was a famous medical expert in the Ming Dynasty, who authored the Gu Jin Yi Tong Da Quan and the Yi Xue Zhi Nan Jie Jing Liu Shu. This paper uses the Xu family genealogy, literature catalog, historical recor... Xu Chunfu was a famous medical expert in the Ming Dynasty, who authored the Gu Jin Yi Tong Da Quan and the Yi Xue Zhi Nan Jie Jing Liu Shu. This paper uses the Xu family genealogy, literature catalog, historical records to study the Xu family’s life and deeds. Xu Chunfu was born in the second year of the Jiajing reign of the Ming Dynasty (1523) and passed away in the 24th year of the Wanli reign of the Ming Dynasty (1596). He served as an official in the Tai Hospital for about 20 years. His work Gu Jin Yi Tong Da Quan was written around the 43rd year of the Jiajing reign of the Ming Dynasty (1556), with a lower limit of the fifth year of the Longqing reign of the Ming Dynasty (1571), and the initial engraving time was not earlier than the eighth year of the Wanli reign of the Ming Dynasty (1580). This paper corrects the shortcomings and errors in previous research, and provides a comprehensive and systematic examination of Xu Chunfu’s life and works. 展开更多
关键词 Xu Chunfu life history biographical verification Gu Jin Yi Tong Da Quan Yi Xue Zhi Nan Jie Jing Liu Shu Genealogy of the Xu Clan in Qimen Tangtou Yinan and Chiling
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Covariation in Insular Life-history Traits of the Rice Frog(Fejervarya limnocharis)in Eastern China
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作者 Feng XU Gregory H.ADLER Yiming LI 《Asian Herpetological Research》 SCIE 2013年第1期28-35,共8页
Although shifts in life-history traits of insular vertebrates, as compared with mainland populations, have been observed in many taxa, few studies have examined the relationships among individual life-history traits o... Although shifts in life-history traits of insular vertebrates, as compared with mainland populations, have been observed in many taxa, few studies have examined the relationships among individual life-history traits on islands. Lifehistory theory also predicts that there is a trade-off between body size and reproductive effort, and between egg size and clutch size. We surveyed the rice frog, Fejervarya limnocharis, on 20 islands within the Zhoushan Archipelago and two nearby sites on the mainland of China to compare differences in life-history traits and to explore relationships among those traits. Rice frog females reached a greater body size on half of the smaller islands among the total 20 surveyed islands, and larger egg size, decreased clutch size and reduced reproductive effort on most of the islands when compared to the two mainland sites. Insular body size was negatively correlated with reproductive effort. There was a negative correlation between egg size and clutch size. Results suggest that life-history theory provides a good explanation for co-variation between body size and reproductive effort, and between egg size and clutch size in rice frogs on the islands. 展开更多
关键词 island syndrome life-history traits trade-off body size egg size clutch size reproductive effort
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Study on fish life history traits and variation in the Taiwan Strait and its adjacent waters 被引量:3
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作者 HU Wenjia YE Guanqiong +4 位作者 LU Zhenbin DU Jianguo CHEN Mingru CHOU Loke Ming YANG Shengyun 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第2期45-54,共10页
Large portions of the world's fishery resources are overexploited. Life history traits of fish species are important indicators to reveal different life history strategies and to indicate population responses to fish... Large portions of the world's fishery resources are overexploited. Life history traits of fish species are important indicators to reveal different life history strategies and to indicate population responses to fishing pressures. For this study, empirical data on fishing grounds located in the coastal area between Fujian Coast and Taiwan Island were collected. These areas have experienced severe overfishing in the past 30 years, leading to changes in the structure and function of the fish communities. Fifty-one commercial fish species in this fishing ground were selected to study the life history traits. Using the life history traits, all the species were grouped into five different life history strategies by principle component analysis. More than 60% of the species were categorized in Group 5 that was similar to r-strategists. Twenty-five commercial species were selected for further analysis of changes in life history variables, and to discuss the population responses to exploitation. Results showed that most of the species appeared to become smaller size, shorter life, earlier maturation and faster growing under long-term exploitation. The exploitation rate of each species was also calculated to further discuss the impacts of fishing pressures to fish populations. Four species were found with the severest changes on life history traits indicating some of the species might be more susceptible to exploitation. This study on fish life history traits and their long-term variations under fishing pressures could provide important scientific implications for fishery management and conservation. 展开更多
关键词 life history traits fish life history strategy fishery exploitation the Taiwan Strait
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Temperature Effect on the Life History of Three Types of Brachionus calyciflorus Females 被引量:4
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作者 席贻龙 黄祥飞 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2004年第2期192-197,共6页
The effect of temperature on the life history characteristics of amictic females (AF), unfertilized mictic females (UMF) and fertilized mictic females (FMF) in Brachionus calyciflorus was studied with replicated indiv... The effect of temperature on the life history characteristics of amictic females (AF), unfertilized mictic females (UMF) and fertilized mictic females (FMF) in Brachionus calyciflorus was studied with replicated individual cultures at 20℃,25℃ and 30℃, and with algae Scenedesmus obliquus for their food. There were highly significant effects of both temperature and female type, independently and interactively, on the duration of juvenile and post-reproduction periods, and the number of eggs produced by the rotifer per life cycle. Among all the temperature-female type combinations, all the juvenile periods of FMF, and the post-reproduction periods of UMF and FMF at 20℃, were the longest, and the number of eggs produced by an UMF at 30℃ was the highest. There were highly significant effects of both temperature and female type on the duration of the reproduction period, but no clear correlation was observed between temperature and female type. The reproduction period of AF was longer than that of UMF and FMF. Only temperature influenced significantly the mean life-span of the three types of females. The duration of juvenile, reproduction and post-reproduction periods as well as the life-span of the three types of females were all reduced very significantly with rise of temperature, but the rates of reduction varied with female type. Among the three types of females, the number of eggs produced per life cycle by an UMF was the highest, and that of a FMF was the lowest. A significant relationship between the number of eggs produced per life cycle and temperature was observed only in the UMF. 展开更多
关键词 Brachionus calyciflorus ROTIFER life history TEMPERATURE female type
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Significant Effects of Fishing Gear Selectivity on Fish Life History 被引量:4
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作者 LIANG Zhenlin SUN Peng +2 位作者 YAN Wei HUANG Liuyi TANG Yanli 《Journal of Ocean University of China》 SCIE CAS 2014年第3期467-471,共5页
Over the past few decades, extreme changes have occurred in the characters of exploited fish populations. The majority of these changes have affected the growth traits of fish life history, which include a smaller siz... Over the past few decades, extreme changes have occurred in the characters of exploited fish populations. The majority of these changes have affected the growth traits of fish life history, which include a smaller size-at-age, an earlier age-at-maturation and among others. Currently, the causes of these life history traits changes still require systematic analyses and empirical studies. The explanations that have been cited are merely expressed in terms of fish phenotypic adaptation. It has been claimed that the original traits of fish can be recovered once the intensity of exploitation of the fish is controlled. Sustained environmental and fishing pressure will change the life history traits of most fish species, so the fish individual's traits are still in small size-at-age and at earlier age-at-maturation in exploited fish populations. In this paper, we expressed our view of points that fishing gear has imposed selectivity on fish populations and individuals as various other environmental factors have done and such changes are unrecoverable. According to the existing tend of exploited fish individual's life history traits, we suggested further researches in this field and provided better methods of fishery management and thereby fishery resources protection than those available early. 展开更多
关键词 size composition life history fishing gear selectivity fishery management
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Effects of Microcystis aeruginosa on life history of water flea Daphnia magna 被引量:3
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作者 刘利平 李慷 +3 位作者 陈桃英 戴习林 江敏 James S. DIANA 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第4期892-897,共6页
Cyanobacterial blooms in eutrophic freshwater systems are a worldwide problem, creating adverse effects for many aquatic organisms by producing toxic mierocystins and deteriorating water quality. In this study, microc... Cyanobacterial blooms in eutrophic freshwater systems are a worldwide problem, creating adverse effects for many aquatic organisms by producing toxic mierocystins and deteriorating water quality. In this study, microcystins (MCs) in Microcystis aeruginosa, and Daphnia magna exposed to M. aeruginosa, were analyzed by HPLC-MS, and the effects of M. aeruginosa on D. magna were investigated. When D. magna was exposed to M. aeruginosa for more than 2 h, Microcystin-LR (MC-LR) was detected. When exposed to 1.5× 10^6, 3× 10^6, 0.75× 10^7, and 1.5× 10^7 cell/mL of M. aeruginosa for 96 h, average survival of D. magna for treatments were 23.33%, 33.33%, 13.33%, 16.67%, respectively, which were significantly lower than the average 100% survival in the control group (P 〈 0.05). The adverse effects ofM. aeruginosa on body length, time for the first brood, brood numbers, gross fecundity, lifespan, and population growth olD. magna were density-dependent. These results suggest that the occurrence of M. aeruginosa blooms could strongly inhibit the population growth of D. magna through depression of survival, individual growth and gross fecundity. In the most serious situations, M. aeruginosa blooms could undermine the food web by eliminating filter-feeding zooplankton, which would destroy the ecological balance of aquaculture water bodies. 展开更多
关键词 Microcvstis aeruginosa Daphnia magna life history TOXICITY
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A two-parameter model to predict fatigue life of high-strength steels in a very high cycle fatigue regime 被引量:7
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作者 Chengqi Sun Xiaolong Liu Youshi Hong 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2015年第3期383-391,共9页
In this paper, ultrasonic (20 kHz) fatigue tests were performed on specimens of a high-strength steel in very high cycle fatigue (VHCF) regime. Experimental results showed that for most tested specimens failed in ... In this paper, ultrasonic (20 kHz) fatigue tests were performed on specimens of a high-strength steel in very high cycle fatigue (VHCF) regime. Experimental results showed that for most tested specimens failed in a VHCF regime, a fatigue crack originated from the interior of specimen with a fish-eye pattern, which contained a fine granular area (FGA) centered by an inclusion as the crack origin. Then, a two-parameter model is proposed to predict the fatigue life of high-strength steels with fish-eye mode failure in a VHCF regime, which takes into account the inclusion size and the FGA size. The model was verified by the data of present experiments and those in the literature. Furthermore, an analytic formula was obtained for estimating the equivalent crack growth rate within the FGA. The results also indicated that the stress intensity factor range at the front of the FGA varies within a small range, which is irrespective of stress amplitude and fatigue life. 展开更多
关键词 Very high-cycle fatigue - High-strength steels Fatigue life Inclusion size Crack growth rate
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Sexual Fusion and Life History of Scytosiphon lomentaria (Scytosiphonaceae, Phaeophyceae) in Dalian, China 被引量:1
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作者 LI Xiaoli ZHANG Zeyu +1 位作者 DONG Shuanglin CAO Shuqing 《Journal of Ocean University of China》 SCIE CAS 2011年第2期170-176,共7页
Morphology and life history of a brown alga Scytosiphon lomentaria (Lyngbye) Link (Scytosiphonaceae, Phaeophyceae) were investigated from 2005 to 2009 in the coastal waters of Dalian, China. The erect thalli collected... Morphology and life history of a brown alga Scytosiphon lomentaria (Lyngbye) Link (Scytosiphonaceae, Phaeophyceae) were investigated from 2005 to 2009 in the coastal waters of Dalian, China. The erect thalli collected in the field were tubular, hollow, and commonly constricted at intervals. Ascocysts were presented. Plurilocular gametangia, which were positioned in continuous sori on the erect thallus surface, produced biflagellar gametes. Gametophytes were dioecious and gametes were nearly isogamous. Gametes fusion occurred in three types. Type one, female and male gametes fused directly while swimming; type two, female gamete settled first, with which a male one contacted and fused rapidly; type three, while settling adjacently, a male gamete's entire protoplast moved slowly into the previously settled female one, with only an empty cell membrane left. In culture zygotes developed into crustose sporophytes that formed unilocular sporangia. Biflagellar zoospores developed into erect thalli that formed plurilocular gametangia. The results indicated that a periodical heteromorphic alternation history with haploid gametophyte generation and diploid sporophyte generation exists in S. lomentaria of the Dalian populations. 展开更多
关键词 sexual fusion life history MORPHOLOGY Scytosiphon lomentaria
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