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浅析我国的文盲人口问题
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作者 戴星翼 《人口与经济》 CSSCI 北大核心 1990年第6期23-26,64,共5页
怎样开展扫盲活动,首先有一个如何看待文盲人口作用和认识文盲人口运动变化规律的问题,在此基础上,我们才能有正确的行动计划。按笔者浅见,目前对国内文盲人口现状的成因上,主要是旧中国教育事业极端落后和近些年来对教育重视不够及体... 怎样开展扫盲活动,首先有一个如何看待文盲人口作用和认识文盲人口运动变化规律的问题,在此基础上,我们才能有正确的行动计划。按笔者浅见,目前对国内文盲人口现状的成因上,主要是旧中国教育事业极端落后和近些年来对教育重视不够及体脑收入倒挂导致读书无用论重新抬头这两点;在对文盲人口作用的认识上,较多文献的看法往往来自中外教育统计数据的比较。虽然这些研究是重要的和基本的,但还有必要以另外一些角度作一些观察和分析,以深化我们对文盲人口问题的理解。 展开更多
关键词 文盲 劳动力 人口问题 国文 扫盲班 人口作用 文盲率 科技文化 低层次 读书无用论
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城市化水平增长曲线的类型、分段和研究方法 被引量:31
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作者 陈彦光 《地理科学》 CSCD 北大核心 2012年第1期12-17,共6页
城市化水平增长曲线可以分为S形和J形2大类别,其变化特征、动力学背景及研究方法也不尽相同。城市化曲线研究可以分为唯象分析和唯理分析2大途径,唯理研究包括城—乡人口异速生长、城—乡人口替代以及城乡人口迁移和转换3种路径,目前这... 城市化水平增长曲线可以分为S形和J形2大类别,其变化特征、动力学背景及研究方法也不尽相同。城市化曲线研究可以分为唯象分析和唯理分析2大途径,唯理研究包括城—乡人口异速生长、城—乡人口替代以及城乡人口迁移和转换3种路径,目前这些方法主要用于S形曲线研究,对J形曲线的探索不够深入。S形曲线是一种奇对称曲线,其模型导数却是一条偶对称曲线,根据这些特征可以将城市化的S曲线分为3或4个阶段。发展中城市化过程通常不能有效拟合S形曲线,却表现出J形曲线的特征。但是,J形曲线及其函数的导数曲线均不对称,其动力学根源和阶段划分方法暂时尚不明朗。中国未来的城市化曲线研究似乎应该将重点放在J形曲线方面,揭示J形曲线更有助于人们从理论上理解中国的城市化动力学。 展开更多
关键词 城市化水平 城市化曲线 S形曲线 J形曲线 异速生长 城乡人口替代 城乡人口相互作用
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Age-dependent impact of the SYNTAX-score on longer-term mortality after percutaneous coronary intervention in an all-comer population 被引量:4
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作者 Madeleine Eickhoff Stefanie Schupke +11 位作者 Alexander Khandoga Julia Fabian Moritz Baquet David Jochheim David Grundmann Manuela Thienel Axel Bauer Hans Theiss Stefan Brunner Jorg Hausleiter Steffen Massberg Julinda Mehilli 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2018年第9期559-566,共8页
Background The Synergy between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery (SYNTAX)-score is a validated tool for risk stratification and revascularization strategy selection in patients with c... Background The Synergy between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery (SYNTAX)-score is a validated tool for risk stratification and revascularization strategy selection in patients with complex coronary artery disease. The aim of this study was to analyse its age-related prognostic value. Methods SYNTAX-score was calculated in 1331 all-comer patients undergoing percutaneous coronary intervention (PCI): 463 patients ≥ 75 years and 868 patients 〈 75 years. Outcomes of interest were all-cause mortality at one and two years. Results A significant interaction of age and SYNTAX-score for mortality was observed at two-year (Pinteraction= 0.019) but not at one-year follow-up (Pinteraction= 0.594). In multivariable analysis, SYNTAX-score independently predicted 1-year mortality in both age groups (〈 75 years, hazard ratio (HR): 1.43, 95% confidence intervals (CI): 1.03-2.00, P = 0.034; and 〉 75 years, HR: 1.37, 95% CI: 1.01-1.85, P = 0.042), but only two-year mortality among younger patients (〈 75 years, HR: 1.33, 95% CI: 1.01-1.76, P = 0.041; and ≥ 75 years, HR: 1.11, 95% CI: 0.87-1.41, P = 0.394). SYNTAX-score tertiles were useful to stratify 1-year mortality in both, patients 〈 75 years (SYNTAX-score 〈 9, 3.8%; 9-20, 5.3%; 〉 20, 10.3%; P = 0.004) and 〉 75 years (SYNTAX-score 〈 11, 5.7%; 11-22.5, 16.1%; 〉 22.5, 18.7%; P = 0.003), but two-year mortality only among patients 〈 75 years (SYNTAX-score 〈 9, 6.5%; 9-20, 7.6%; ≥ 20, 15%; P 〈 0.001) and not among ≥ 75 years old patients (SYNTAX-score 〈 11, 19.4%; 11-22.5, 26.3%; _〉 22.5, 27.9%; P = 0.138). Conclusions Age modi- fies the impact of the SYNTAX-score on longer-term mortality after PCI. Among patients 〈 75 years, the SYNTAX-score independently predicts the risk of death at one and two years after PCI, while among patients 〉 75 years its predictive role is limited to the first year after PCI. Further studies are needed to evaluate the value of SYNTAX-score for selecting the most appropriate revascularization strategy among elderly patients. 展开更多
关键词 Age MORTALITY Percutaneous coronary intervention Syntax-score The elderly
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Health-related quality of life of 256 recipients after liver transplantation 被引量:6
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作者 Pei-Xian Chen Lu-Nan Yan Wen-Tao Wang 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第36期5114-5121,共8页
AIM:To investigate health-related quality of life(HRQoL) and psychological outcomes in 256 adults who had undergone liver transplantation(LT).METHODS:A stratified random sampling method was used in this follow-up mult... AIM:To investigate health-related quality of life(HRQoL) and psychological outcomes in 256 adults who had undergone liver transplantation(LT).METHODS:A stratified random sampling method was used in this follow-up multicenter study to select a representative sample of recipients undergoing either living donor liver transplantation(LDLT) or deceased donor liver transplantation(DDLT).HRQoL was measured by using the Chinese version of Medical Outcome Study Short Form-36(SF-36),and psychological outcomes by using the beck anxiety inventory(BAI) and the self-rating depression scale(SDS).Clinical and demographic data were collected from the records of the Chinese Liver Transplant Registry and via questionnaires.RESULTS:A total of 256 patients were sampled,including 66(25.8%) receiving LDLT and 190(74.2%) undergoing DDLT;15(5.9%) recipients had anxiety and four(1.6%) developed severe depression after the operation.Compared with LDLT recipients,DDLT patients had higher scores in general health(60.33 ± 16.97 vs 66.86 ± 18.42,P = 0.012),role-physical(63.64 ± 42.55 vs 74.47 ± 36.46,P = 0.048),roleemotional(61.11 ± 44.37 vs 78.95 ± 34.31,P = 0.001),social functioning(78.60 ± 22.76 vs 88.16 ± 21.85,P = 0.003),vitality(70.30 ± 15.76 vs 75.95 ± 16.40,P = 0.016),mental health(65.88 ± 12.94 vs 71.85 ± 15.45,P = 0.005),physical component summary scale(PCS,60.07 ± 7.36 vs 62.58 ± 6.88,P = 0.013) and mental component summary scale(MCS,52.65 ± 7.66 vs 55.95 ± 10.14,P = 0.016).Recipients > 45 years old at the time of transplant scored higher in vitality(77.33 ± 15.64 vs 72.52 ± 16.66,P = 0.020),mental health(73.64 ± 15.06 vs 68.00 ± 14.65,P = 0.003) and MCS(56.61 ± 10.00 vs 54.05 ± 9.30,P = 0.037) than those aged ≤ 45 years.MCS was poorer in recipients with than in those without complications(52.92 ± 12.21 vs 56.06 ± 8.16,P = 0.017).Regarding MCS(55.10 ± 9.66 vs 50.0 ± 10.0,P < 0.05) and PCS(61.93 ± 7.08 vs 50.0 ± 10.0,P < 0.05),recipients scored better than the Sichuan general and had improved overall QoL compared to patients with chronic diseases.MCS and PCS significantly correlated with scores of the BAI(P < 0.001) and the SDS(P < 0.001).CONCLUSION:Age > 45 years at time of transplant,DDLT,full-time working,no complications,anxiety and depression were possible factors influencing postoperative HRQoL in liver recipients. 展开更多
关键词 Liver transplantation Living donor livertransplantation Deceased donor liver transplantation PSYCHOLOGY Health-related quality of life
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Changing human-environment interactions in medium mountains:the Apuseni Mts(Romania)as a case study 被引量:4
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作者 TELBISZ Tamas IMECS Zoltan +1 位作者 MARl Laszlo BOTTLIK Zsolt 《Journal of Mountain Science》 SCIE CSCD 2016年第9期1675-1687,共13页
The study of human-environment relationships in mountain areas is important for both theoretical and practical reasons, as many mountain areas suffer similar problems, such as depopulation, unemployment and natural ha... The study of human-environment relationships in mountain areas is important for both theoretical and practical reasons, as many mountain areas suffer similar problems, such as depopulation, unemployment and natural hazards. Medium mountains constitute a special case within mountains, because they are more populated but less attractive as tourist destinations than high mountains. In this context, the Apuseni Mts (Romania) are considered as a ease study. In this paper, we apply GIS-based, quantitative methods to characterize the strength and dynamics of human-environment interactions, taking into consideration some environmental factors (elevation, relative height, slope, river distance, lithology, land cover, natural attractions) as well as historical population and recent tourism data. We found that population density has strong (r2〉0.8) relationships with all relief factors (elevation, relative height, slope, river distance), and that best-fit functions are nonlinear. We outlined the varying demographic scenarios by elevation zones and interpreted the historically switching sign of population change versus elevation relationship. We demonstrated that lithology also has an impact on the spatial distribution of population, although it is not independent from the relief effect. The land cover of the mainly cultural landscape is very strongly correlated with relief parameters (especially slope), which suggests good adaptation. We pointed out the dominance of karst objects in the natural tourism potential of the Apuseni Mts and also explored further components of real tourism (spas, heritage, towns). Finally, we concluded that the environmental settings investigated do in fact constrain the spatial framework of society, but soeio-economic changes in history can be explained from the side of society, which conforms to the theory of cultural possibilism. 展开更多
关键词 Human-environment relations ApuseniMountains Geographical information system (GIS) Possibilism TOURISM KARST
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Interacting Super-Brownian Motions Depending on Population Size
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作者 CHEN Li YAN Guo-jun 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2008年第2期178-187,共10页
In this paper, we investigate the interacting super-Brownian motion depending on population size. This process can be viewed as the high density limit of a sequence of particle systems with branching mechanism dependi... In this paper, we investigate the interacting super-Brownian motion depending on population size. This process can be viewed as the high density limit of a sequence of particle systems with branching mechanism depending on their population size. We will construct a limit function-valued dual process. 展开更多
关键词 SUPERPROCESS Brownian sheet martingale problem limit dual process
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The Interaction of Population,Industry and Land in Process of Urbanization in China:A Case Study in Jilin Province 被引量:13
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作者 LIU Yanjun ZHOU Guolei +3 位作者 LIU Degang YU Huisheng ZHU Liyuan ZHANG Jing 《Chinese Geographical Science》 SCIE CSCD 2018年第3期529-542,共14页
Urbanization is a complex process that covers a wide range of topics, of which population, industry and land urbanization are three important aspects. Jilin Province is an important agricultural province in China. The... Urbanization is a complex process that covers a wide range of topics, of which population, industry and land urbanization are three important aspects. Jilin Province is an important agricultural province in China. The contradiction between population, industry and land urbanization is especially prominent here, and its coupling development is of great practical significance. In this paper, the coupling degree of population-industry-land urbanization in Jilin Province in 1990, 2000 and 2010 is measured by coupling mode. The spatial pattern of the coupling degree is analyzed by trend surface analysis and global and local spatial autocorrelation. The influence factors and their spatial differentiation are discussed using multiple linear regression(MLR) model and geographic weighted regression(GWR) model. The results show that: 1) the coupling degree of population-industry-land urbanization in Jilin Province is at a low level. Judging from the change of time scale, the urbanization of most research units is becoming more and more coordinated. From the comparison of spatial scales, there is significant spatial difference in the research units of different administrative levels. 2) Judging from the global change trend, the coupling degree of population-industry-land urbanization in the central region is higher than that in western and eastern regions. The coordination of urbanization in the central region is relatively good, and the distribution of the cold and hot spots is basically the same as that overall. 3) The spatial pattern of the coupling degree is related to the cold and hot spot distribution of the influence coefficient of urban population density and per capita urban construction land. The variation of the coupling degree spatial pattern is synchronous with the spatial change of the urban population density influence coefficient. 4) The degree of agglomeration of the urban population is the main factor promoting the coupling pattern of population-industry-land urbanization in Jilin Province, and the extent of its influence is gradually increasing. In addition, the level of city administrative, the efficiency of urban expansion and the capacity of market consumption also have an important influence on the coupling pattern. 展开更多
关键词 population urbanization industry urbanization land urbanization coupling relationship influence mechanism Jilin Province
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Monomer Migration and Annihilation Processes
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作者 KEJian-Hong LINZhen-Quan ZHUANGYou-Yi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第5期953-956,共4页
We propose a two-species monomer migration-annihilation model, in which monomer migration reactions occur between any two aggregates of the same species and monomer annihilation reactions occur between two different s... We propose a two-species monomer migration-annihilation model, in which monomer migration reactions occur between any two aggregates of the same species and monomer annihilation reactions occur between two different species. Based on the mean-field rate equations, we investigate the evolution behaviors of the processes. For the case with an annihilation rate kernel proportional to the sizes of the reactants, the aggregation size distribution of either species approaches the modified scaling form in the symmetrical initial case, while for the asymmetrical initial case the heavy species with a large initial data scales according to the conventional form and the light one does not scale. Moreover,at most one species can survive finally. For the case with aconstant annihilation rate kernel, both species may scale according to the conventional scaling law in the symmetrical case and survive together at the end. 展开更多
关键词 kinetic behavior MIGRATION ANNIHILATION scaling law
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Thoughts on the Sustainable Design Medium of Urban Communities Within Information and Telecommunication Technologies
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作者 Tigran Haas Reza Kazemian 《Sociology Study》 2018年第4期188-205,共18页
The rapid development of informational accessibility, virtual commutability, and their impacts on cities are becoming parts of the very core of concerns of contemporary urban design theories and methodologies. The lev... The rapid development of informational accessibility, virtual commutability, and their impacts on cities are becoming parts of the very core of concerns of contemporary urban design theories and methodologies. The level of access to the new means of cybermobility is becoming a formative factor for socio-spatial gradients and demographic patterns in urban and suburban settings. While the new hyper drive towards the ubiquitous virtual mobility is becoming the dominant mode of our being, it is exposing disparate consequences to cultural experiences, economic conditions, and socio-spatial networks of communities The paper is devoted to elaborate the transformational role of cybernomadic experiences on social interaction for a resilient design of urban communities. The ultimate goal is to identify the applicability of new technological opportunities to empowering the urban poor and finding out the challenges facing urban design territories. The paper also reflects on Jane Jacobs' urban vision for the future and its specific lens 展开更多
关键词 Urban planning placemaking cybernomadism virtual mobility Jane Jacobs
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Conflict between Population and Urbanization Factors: Impact of Urban Heat Island on Energy Consumption Balance
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作者 Parisa Shahmohamadi Che-Ani A. I. +2 位作者 Iraj Etessan Khairul Nizam Abdul Maulud M. F. I. Mohd-Nor 《Journal of Civil Engineering and Architecture》 2010年第10期16-23,共8页
High density of buildings and population in urban areas increases urban temperature, generally known as the urban heat island. Raised temperature, especially in SUlIuner, alms city centers into unwelcome hot areas, wi... High density of buildings and population in urban areas increases urban temperature, generally known as the urban heat island. Raised temperature, especially in SUlIuner, alms city centers into unwelcome hot areas, with direct effects on electricity demand and energy consttrnption for cooling buildings and increases the production of carbon dioxide and other pollutants. Therefore, by considering that the energy consumption in the world has been faced with intense crisis, it becomes increasingly important to study the effects of urban heat island on energy constunption in order to improve people's environment and decrease energy use in cities. This paper, therefore, is focused on urbanization and population size factors to understand tile influence way of these factors on formation of UHI and energy consumption balance. To achieve this aim, this paper explores literally the conceptual framework of confliction between population and urban structure, which produce UHI intensity and affected energy consumption balance. It is then discussed how these two factors can be affected and give implication to the city, and then, focuses on whether actions should be taken for balancing adaptation and mitigation UHI effects. It will be concluded by making the recommendations for preventive action and provide quality of life. 展开更多
关键词 Energy consumption balance urban construction urban heat island ttrban population.
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Effects of Dimers on Cooperation in the Spatial Prisoner's Dilemma Game
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作者 李海红 程洪艳 +3 位作者 代琼琳 鞠萍 章梅 杨俊忠 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第11期813-818,共6页
We investigate the evolutionary prisoner's dilemma game in structured populations by introducing dimers, which are defined as that two players in each dimer always hold a same strategy. We find that influences of dim... We investigate the evolutionary prisoner's dilemma game in structured populations by introducing dimers, which are defined as that two players in each dimer always hold a same strategy. We find that influences of dimets on cooperation depend on the type of dimers and the population structure. For those dimers in which players interact with each other, the cooperation level increases with the number of dimers though the cooperation improvement level depends on the type of network structures. On the other hand, the dimers, in which there are not mutual interactions, will not do any good to the cooperation level in a single community, but interestingly, will improve the cooperation level in a population with two communities. We explore the relationship between dimers and self-interactions and find that the effects of dimers are similar to that of self-interactions. Also, we find that the dimers, which are established over two communities in a multi-community network, act as one type of interaction through which information between communities is communicated by the requirement that two players in a dimer hold a same strategy. 展开更多
关键词 prisoner's dilemma game cooperation frequency NETWORKS
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Interaction Study between Population Mobility and Economic Growth : Evidence from Chongqing
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作者 Li Xiaoyang 《China Population Today》 2016年第3期48-48,共1页
Based on economic convergence model and its derivatives, this paper examines the relationship between popultion mobility and economic growth in Chongqing and its five functional areas by using 2000~2013 panel data. Th... Based on economic convergence model and its derivatives, this paper examines the relationship between popultion mobility and economic growth in Chongqing and its five functional areas by using 2000~2013 panel data. The results show that there exists interactive relationship between population mobility and economic growth, and this interaction is rendered as mutual inhibition. The restrain from economic growth to population mobility shows smaller effect than the reverse. In the sparsely populated areas, economic growth is promoted by population mobility, and in the densely populated areas, economic growth is driven by investment. Therefore, government has to regulate population mobility to achieve sustainable economic growth. 展开更多
关键词 Chongqing densely sustainable restrain mutual interactive panel regulate promoted
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控制第三次人口生育高峰 实现本世纪末人口控制目标 被引量:3
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作者 马瀛通 《中国人口科学》 CSSCI 北大核心 1989年第1期9-12,8,共5页
新中国成立以后,我国人口发展历经两次人口生育高峰期。1986年人口出生率回升为20.77‰,一般认为,我国人口已步入第三次人口生育高峰期。第一、二次人口生育高峰期之所以称为高峰期,最重要的函意是,其形成原是由于对人口作用认识不足及... 新中国成立以后,我国人口发展历经两次人口生育高峰期。1986年人口出生率回升为20.77‰,一般认为,我国人口已步入第三次人口生育高峰期。第一、二次人口生育高峰期之所以称为高峰期,最重要的函意是,其形成原是由于对人口作用认识不足及工作没有跟上造成。 展开更多
关键词 人口作用 生育高峰期 农村 实行计划生育 人口出生率 政府 妇女 计划生育工作 人口控制 生育水平
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武汉市人口扩散与就业扩散的时空关系研究 被引量:6
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作者 朱丽霞 罗逍 +1 位作者 罗静 胡娟 《经济地理》 CSSCI 北大核心 2014年第5期69-75,共7页
利用武汉市2007—2011年的人口和就业面板数据,通过ArcGIS方法探索人口与就业的分布与扩散在空间上的差异性,再运用异速增长模型和人口—就业相互作用模型分析二者的空间协调性及其引致关系。结果发现,武汉市就业主要集中于中心城区,而... 利用武汉市2007—2011年的人口和就业面板数据,通过ArcGIS方法探索人口与就业的分布与扩散在空间上的差异性,再运用异速增长模型和人口—就业相互作用模型分析二者的空间协调性及其引致关系。结果发现,武汉市就业主要集中于中心城区,而人口近一半集中在近远郊区;2007—2011年,人口和就业仍向中心城区集中的同时也向外围扩散,各圈层人口与就业扩散同步性较差,特别是在内部圈层,就业先于人口向郊区扩散;总体上武汉市各圈层的人口与就业发展相对独立,并不存在相互的引致关系。 展开更多
关键词 人口扩散 就业扩散 异速增长模型 人口—就业相互作用 武汉市
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Variation in female aggression in 2 three-spined stickleback populations with female throat and spine coloration 被引量:1
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作者 Lengxob YONG Brittney LEE Jeffrey S. MCKINNON 《Current Zoology》 SCIE CAS CSCD 2018年第3期345-350,共6页
Despite growing interest in female ornament evolution, we still have a rudimentary understanding of female display traits relative to similar traits in males. Under one popular adaptive scenario, female ornaments are ... Despite growing interest in female ornament evolution, we still have a rudimentary understanding of female display traits relative to similar traits in males. Under one popular adaptive scenario, female ornaments are hypothesized to function in female-female competition and serve as badges of status, such that their expression is linked with elevated aggression in some cases. In this study, we investigated the relationship between 2 female ornaments--male-like red throat color and red spine coloration--and female aggression in 2 independently derived stream-resident populations of three-spined stickleback Gasterosteus aculeatus. Using simulated intrusions, we tested whether females with redder ornaments were generally more aggressive, and for variation in aggressive and social behaviors between the 2 populations. We found that the red intensity of the throat and spine did not predict aggression levels in either population, suggesting a limited role for both female ornaments during female-female interaction. The 2 populations exhibited different levels of aggressive behaviors, unrelated to the color patches. Our results suggest that variation in selective pressures between populations may promote interpopulation variance in aggressive behavior but not the correlation between female ornamentation and aggression, and raise the possibility that red coloration may have evolved through different mechanisms or processes in the 2 populations. 展开更多
关键词 AGGRESSION animal coloration female ornaments Gasterosteus aculeatus stickleback.
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GLOBAL ATTRACTIVITY OF POPULATION MODELS WITH DELAYS AND DIFFUSION
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作者 QIU Zhipeng Department of Applied Mathematics, Nanjing University of Science and Technology, Nanjing 210094 Department of Mathematics, University of Science and Technology of China, Hefei 230026, China. 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2005年第3期396-403,共8页
In this paper, the asymptotic behavior of three types of population models with delays and diffusion is studied. The first represents one species growth in the patch Ω and periodic environment and with delays recruit... In this paper, the asymptotic behavior of three types of population models with delays and diffusion is studied. The first represents one species growth in the patch Ω and periodic environment and with delays recruitment, the second models a single species dispersal among the m patches of a heterogeneous environment, and the third models the spread of bacterial infections. Sufficient conditions for the global attractivity of periodic solution are obtained by the method of monotone theory and strongly concave operators. Some earlier results are extended to population models with delays and diffusion. 展开更多
关键词 DELAYS population models global attractivity REACTION-DIFFUSION
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Competition for food in 2 populations of a wild-caught fish
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作者 Pierre J.C. CHUARD Grant E. BROWN James W.A. GRANT 《Current Zoology》 SCIE CAS CSCD 2018年第5期615-622,共8页
Aggressive behavior when competing for resources is expected to increase as the ratio of competitors-to-resource ratio (CRR) units increases. Females are expected to be more aggressive than males when competing for ... Aggressive behavior when competing for resources is expected to increase as the ratio of competitors-to-resource ratio (CRR) units increases. Females are expected to be more aggressive than males when competing for food when body size is more strongly related to reproductive suc- cess in females than in males, whereas aggression is predicted to decrease under high ambient predation risk by natural selection. Under the risk allocation model, however, individuals under high ambient predation risk are expected to be more aggressive, and forage more in the absence of imminent risk than their low risk counterparts. An interaction between adult sex ratio (i.e., adult males/females), ambient predation risk (high vs. low), and sex on intrasexual competition for mates in Trinidadian guppies Poecilia reticulata has been shown. The interaction suggested an increase in aggression rates as CRR increased, except for males from the high predation population. To compare the patterns of competition for food versus mates, we replicated this study by using food patches. We allowed 4 male or 4 female guppies from high and low predation populations to com- pete for 5, 3, or 1 food patches. The foraging rate was higher in a high rather than low ambient pre- dation risk population. Surprisingly, CRR, sex, and population of origin had no effect on aggression rates. Despite other environmental differences between the 2 populations, the effect of ambient predation risk may be a likely explanation for differences in foraging rates. These results highlight the importance for individuals to secure food despite the cost of competition and predation. 展开更多
关键词 AGGRESSION competitor-to-resource ratio FORAGING Poecifia reticulata population differences predation risk SEX
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A plant-pollinator system: How learning versus cost-benefit can induce periodic oscillations
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作者 Virgilio Vazquez Ignacio Barradas 《International Journal of Biomathematics》 SCIE 2018年第2期189-215,共27页
In this paper, we propose a model describing the interaction between two species: a plant population that gets pollinated by an insect population. We assume the plant population is divided into two groups: the first... In this paper, we propose a model describing the interaction between two species: a plant population that gets pollinated by an insect population. We assume the plant population is divided into two groups: the first group in mutualistic relationship with the insect and the second group attracting the insects while deceiving them and not delivering any reward. In addition, we assume that the insect population reduces the number of visits to the plants after several unsuccessful visits. We are interested in the conditions for the coexistence of both species, especially in the appearance of damped or sustained oscillations. We focus the analysis on the parameters that measure the balance among deceit, the benefit that the insect gets from the plant, and the learning by the pollinators. We are especially interested in analyzing the effect of learning by the insect population due to unsuccessfully visiting the deceiving plants. 展开更多
关键词 Deceptive pollination MUTUALISM LEARNING oscillations Hopf bifurcation.
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Evolution of Cooperation in Evolutionary Games for Heterogeneous Interactions
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作者 钱晓岚 杨俊忠 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第4期547-552,共6页
When a population structure is modelled as a square lattice,the cooperation may be improved for an evolutionary prisoner dilemma game or be inhibited for an evolutionary snowdrift game.In this work,we investigate coop... When a population structure is modelled as a square lattice,the cooperation may be improved for an evolutionary prisoner dilemma game or be inhibited for an evolutionary snowdrift game.In this work,we investigate cooperation in a population on a square lattice where the interaction among players contains both prisoner dilemma game and snowdrift game.The heterogeneity in interaction is introduced to the population in two different ways:the heterogenous character of interaction assigned to every player(HCP) or the heterogenous character of interaction assigned to every link between any two players(HCL).The resonant enhancement of cooperation in the case of HCP is observed while the resonant inhibition of cooperation in the case of HCL is prominent.The explanations on the enhancement or inhibition of cooperation are presented for these two cases. 展开更多
关键词 evolutionary games heterogenous interactions resonant enhancement and inhibition
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