期刊文献+
共找到3,741篇文章
< 1 2 188 >
每页显示 20 50 100
Study on optimization of the population system and its coordination with natural resources and environment in the Qaidam Basin
1
作者 YU Dan-lin MAO Han-ying FANG Chuang-lin(Laboratory of Modeling and Adjustment of Regional Sustainable Development, Institute ofGeography, Chinese Academy of Sciences, Beijing 100101, China) 《Journal of Geographical Sciences》 SCIE CSCD 1999年第3期248-256,共9页
The population system is the only subsystem tha has charecteristic of subjectivity in theregional PRED system. Influenced by the particular status quo of natural resources and environmentconditions, the population sub... The population system is the only subsystem tha has charecteristic of subjectivity in theregional PRED system. Influenced by the particular status quo of natural resources and environmentconditions, the population subsystem of the Qaidam Basin is very different from those of otherregions'. Based on the on-the-spot investigation to the Qaidam Basin in July 1997, the authors of thispaper sum up several characters of the population subsystem of the Basin. (1) Population mainlyconsisting of the big volume of immigrants and floating population increases very fast. (2) With highpopulation mobility there was great discrepany between the actual number of population (aggregatepopulation) and the statidtical population. (3) Degree of urbanization is very high, and employmentconcentrates mainly on the industrial and teftiary industrial sectors. (4) Sex ratio remains veryunbalanced, especially in the youth group of population which exerts high pressure on employmentand training because of the young age structure. (5) Population quality is relatively high as a wholeWhile educahonal level characterizes the undeveloped regions. In order to predict the futurepopulation of the Basin. according to the characters of population system, this paper puts forward away called dividing-steps-forecast-sum to do the prediction till 2050, use both modeling forecastingmethod and empirical evaluation. The results indicated that the total population of the Basin whllreach 1 .28 million in 2050. Among them, the natural increment and immigrant and floating incrementoccupy 34.99% and 60.86%, respectively, with another 4.13% of special population. In terms ofcharactedstics of population and predicted results as well as the status quo of natural resources andenvironment this paper suggests several thoughts to optimize and adjust the population system of theQaidam Basin. They are, firsuy, to control the number of population as well as improve thepopulation quality, and secondly, to reghate the floating population to assort them withsocioeconomic development in the Basin. Above all, the most important step is to throw high level ofscience and techniqte into the Basin's socioeconomic system to enhance the carrying capacity ofresources and environment and improve the coordinated relationship among population, resources andcnvironment 展开更多
关键词 the Qaidam Basin population system OPTIMIZATION
在线阅读 下载PDF
Spatial patterns of a reaction-diffusion population system with cross-diffusion and habitat complexity 被引量:1
2
作者 Weiyu Li Yanfeng Li Ruizhi Yang 《International Journal of Biomathematics》 2025年第8期69-90,共22页
In this paper,a population system with cross-diffusion and habitat complexity is selected as study object.We investigate that how cross-diffusion and habitat complexity destabilize the otherwise stable periodic soluti... In this paper,a population system with cross-diffusion and habitat complexity is selected as study object.We investigate that how cross-diffusion and habitat complexity destabilize the otherwise stable periodic solutions of the ODEs to generate the new abundant spatial Turing patterns.By utilizing the local Hopf bifurcation theorem and perturbation theory,we establish a formula to determine the Turing instability of periodic solutions of the population system withcross-diffusion and habitat complexity.Finally,numerical simulations are performed to verify theoretical analysis,simultaneously,we verify the formation process of spatial Turing patterns when the cross-diffusion coefficients and habitat complexity change. 展开更多
关键词 population system CROSS-DIFFUSION habitat complexity periodic solution Turing instability
原文传递
Succession of algae population and blooms with their driving factors in China's lakes 被引量:1
3
作者 Jing Cao Zhaosheng Chu +1 位作者 Haifeng Jia Binghui Zheng 《Journal of Environmental Sciences》 2026年第2期13-26,共14页
Algae play an important role in lake ecosystems,and algal succession is vital to studying the mechanism of algal bloom outbreaks.This paper provides a comprehensive review of algae blooms development,bloom-forming alg... Algae play an important role in lake ecosystems,and algal succession is vital to studying the mechanism of algal bloom outbreaks.This paper provides a comprehensive review of algae blooms development,bloom-forming algae succession,the diversity of common blooms-forming algae,and key drivers for algae succession in Chinese lakes,based on an extensive literature survey and data sets.Furthermore,it summarizes the influencing factors for algae blooms and bloom-forming algae succession in five lake zones of China.The results indicated that the number of research publications on algal blooms in China constituted the largest share of global research,representing 41.9 %.The predominant types of algae blooms in all publications were cyanobacterial blooms,followed by dinoflagellate blooms.The blooms-forming algae in China's lakes have experienced a clear succession pattern:Bacillariophyta,Chlorophyta and Pyrrophyta were dominated in the initial investigations;dominance of Microcystis,Anabaena, dinoflagellates and diatoms increased significantly since1960s;in the past decade,Cylindrospermopsis and dinoflagellates expanded.Current research on algae blooms in Chinese lakes mainly focuses on cyanobacterial blooms,especially Microcystis blooms,while researches on filamentous cyanobacterial blooms and other algae blooms is still insufficient.This systematic review will help researchers to understand the basic features such as the occurrence,the diversity,the physio-ecology and the driving factors of common blooms-forming algae,will further provide a scientific basis for their control in various lake regions. 展开更多
关键词 SUCCESSION Algae population Algal blooms Cyanobacterial blooms
原文传递
Optimal boundary control for a competitive population system with size structure and time delay in a polluted environment
4
作者 Fenghui Qin Zhanping Wang 《International Journal of Biomathematics》 2025年第5期223-246,共24页
In this paper,we consider the optimal boundary control problem of a two-species competitive system with time delay and size structure in a polluted environment.First,the well posedness of the system is studied by usin... In this paper,we consider the optimal boundary control problem of a two-species competitive system with time delay and size structure in a polluted environment.First,the well posedness of the system is studied by using the characteristic line method and the fixed point principle.Second,the necessary conditions for optimal boundary control are obtained by conjugate system and normal cone property.Finally,the existence and uniqueness of the optimal strategy are proved by Ekeland variational principle. 展开更多
关键词 Polluted environment time delay size structure competitive population optimal control
原文传递
Global,regional,and national burden of thyroid cancer in working-age population:A systematic analysis for the Global Burden of Disease Study 2021
5
作者 Tingting Zuo He Li +3 位作者 Tianyi Li Yuanjie Zheng Bo Zhu Wanqing Chen 《Chinese Journal of Cancer Research》 2025年第5期759-770,共12页
Objective:This study aims to estimate the thyroid cancer(TC)burden and trends from 1990 and 2021 among working-age population(WAP),at the global,regional,and national levels.Methods:Based on the Global Burden of Disea... Objective:This study aims to estimate the thyroid cancer(TC)burden and trends from 1990 and 2021 among working-age population(WAP),at the global,regional,and national levels.Methods:Based on the Global Burden of Disease 2021 study,this cross-sectional study included data on TC incidence and mortality for WAP aged 15-64 years across 204 countries and territories from 1990 to 2021.The age-standardized incidence rate(ASIR)and age-standardized mortality rate(ASMR)of TC were used to estimate the disease burden.Temporal trends of ASIR and ASMR were estimated by average annual percentage changes(AAPCs)based on age-period-cohort models.Relative inequality of TC burden across 204 countries was estimated by the slope index of concentration index.Results:Globally,ASIR of TC increased from 2.27 per 100,000 population to 3.41 per 100,000 population from1990 to 2021,with AAPC of 1.59%[95%confidence interval(95%CI):1.54,1.64];in contrast,ASMRs were stable at 0.31 per 100,000 population.Females had a higher disease burden than males,and adults aged 45-64 years accounted for more than 55%of the TC cases.Across regions and countries,North Africa and Comoros experienced the highest increase in ASIR,with AAPCs of 2.97%and 7.73%,respectively.All socio-demographic index(SDI)regions experienced a significant increase in ASIR,and regions with high and high-middle SDI experienced a significant decrease in ASMR.Global ASIR burden and ASMR burden were revealed to be concentrated mainly in higher-SDI and lower-SDI countries,respectively,with the concentration index in both sexes of 0.16(95%CI:0.13,0.19)and-0.14(95%CI:-0.18,-0.10)in 2021.Conclusions:Over the past three decades,the incidence burden of TC among the global WAP remarkably increased.International and regional policies for TC controls are supposed to be updated timely,to handle the current increasing burden and geographic disparities among WAP. 展开更多
关键词 Thyroid cancer working-age population global burden of disease estimated annual percentage change health inequality
暂未订购
Ecological Dynamics of a Logistic Population Model with Impulsive Age-selective Harvesting
6
作者 DAI Xiangjun JIAO Jianjun 《应用数学》 北大核心 2026年第1期72-79,共8页
In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asy... In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting. 展开更多
关键词 The logistic population model Selective harvesting Asymptotic stability EXTINCTION
在线阅读 下载PDF
Mapping world’s coastal population facing water-related risks
7
作者 Olli Varis Maija Taka Matti Kummu 《Geography and Sustainability》 2026年第1期206-217,共12页
Endowed with opportunities from both land and ocean,coastal areas attract expanding human populations and economic activities.At the same time,they face growing societal and environmental pressures from both the above... Endowed with opportunities from both land and ocean,coastal areas attract expanding human populations and economic activities.At the same time,they face growing societal and environmental pressures from both the above river catchments and the bordering sea due to climate change,ecosystem degradation,and expansion of built-up areas.Despite the accumulation of human population,economic activities,and environmental impacts,we lack social-ecological systems analysis on water-related risks to world’s coastal human population.To address this research gap,we analyze the spatial extent of six globally important water stressors to people within the world’s coastal zone(100 km from the coastal line)and classify this zone globally into 12 groups by distance from the coastline and elevation from the mean sea level.Adopting the approaches of the UN Sendai Framework and IPCC,we produce risk maps from the stressor maps by multiplying them with population exposure and vulnerability.For most risks,geographical hotspots are the Chinese coast,Bay of Bengal,Gujarat,and the Island of Java.The analysis reveals fundamental differences between water stressors and related risks,often mixed in scholarly literature.Both manifest specific geographic patterns and latitudinal profiles.Our study highlights the importance of high-resolution spatial analysis of vulnerability,exposure,and risks posed by water related stressors in the world’s coastal zone,in a manner prompted by key policy bodies to promote policy design and shared responsibility for managing stress-prone areas. 展开更多
关键词 Coastal zone population RiskSocial-ecological systems Spatial analysis Water
在线阅读 下载PDF
Enlarged Sink Capacity and Optimized Population Physiological Characteristics are Key to High Yield in Conventional Japonica Rice
8
作者 ZHANG Haipeng MI Kailiang +3 位作者 CHEN Ting ZHANG Muyan XU Fangfu ZHANG Hongcheng 《Rice science》 2026年第1期113-128,I0081-I0095,共31页
Clarifying the photosynthetic and population characteristics of conventional japonica rice at different yield levels is crucial for boosting yield and ensuring food security.Therefore,a two-year field trial with two c... Clarifying the photosynthetic and population characteristics of conventional japonica rice at different yield levels is crucial for boosting yield and ensuring food security.Therefore,a two-year field trial with two conventional japonica varieties was conducted at four planting densities:16 cm×30 cm(D1),14 cm×30 cm(D2),12 cm×30 cm(D3),and 10 cm×30 cm(D4).This study aimed to investigate how photosynthetic and population characteristics influence grain yield under varying planting densities.The results indicated that higher yields were primarily driven by increased grain weight and seed-setting rate(with a 9.68%‒11.40%higher single panicle weight),supported by optimized dry matter translocation and source-sink relationships.Elevated planting density(D2‒D4)enhanced panicle number and total spikelet number(by 3.91%‒15.00%)but reduced the number of spikelets per panicle,1000-grain weight,and photosynthetic efficiency due to mutual shading.Despite these trade-offs,yield increased by 4.10%‒12.42%under higher densities.The use of planting density D4 in japonica rice cultivation contributed to maximize yield.These findings provide important theoretical insights and practical significance for increasing the yield of conventional japonica rice and ensuring food security. 展开更多
关键词 conventional japonica YIELD population characteristics photosynthetic efficiency planting density
在线阅读 下载PDF
Satellite tracking reveals a migratory divide and population-specific migratory strategies in White-naped Cranes
9
作者 Lijia Wen Gankhuyag Purev-Ochir +6 位作者 Baasansuren Erdenechim Dashdorj Khurelbaatar Xuezhu Li Xianda Li Yi Hao Yumin Guo Yanjie Xu 《Avian Research》 2026年第1期67-73,共7页
Migratory divides,where individuals from distinct breeding populations within a species exhibit divergent migratory routes and strategies,play a critical role in shaping avian ecology and evolution.These divides can d... Migratory divides,where individuals from distinct breeding populations within a species exhibit divergent migratory routes and strategies,play a critical role in shaping avian ecology and evolution.These divides can drive intraspecific genetic divergence and promote reproductive isolation,potentially leading to population differentiation and speciation.Understanding the migration strategies of populations utilizing distinct flyways is essential not only for elucidating the mechanisms underlying migration patterns but also for informing effective species conservation efforts.From 2014 to 2023,we used satellite tracking to monitor the migration patterns of 87 White-naped Cranes(Antigone vipio)from the species'two breeding populations—western(Mongolia)and eastern(Songnen Plain,China).We delineated their migratory routes,quantified key migration parameters,and identified their population-and season-specific differences in migratory strategies.Our results indicate that the Greater Khingan Mountains and the Bohai-Yellow Sea formed a distinct migratory barrier separating the eastern and western populations.Significant differences in migration strategies were observed between populations and seasons.The western population adopts a"longer-distance,slower-speed,more-stopover"strategy,while the eastern population employs a"shorter-distance,higher-speed,fewer-stopover"strategy.Our study identifies the migratory divides between the two populations of White-naped Cranes and highlights the importance of migratory divides in shaping distinct migration strategies.These findings enhance our understanding of the factors driving population-specific migration strategies and provide a foundation for tailored conservation efforts for these populations. 展开更多
关键词 Bird migration CRANE Ecological barriers Movement ecology population difference
在线阅读 下载PDF
Epidemiological Characteristics of Varicella and Population Immunity against Varicella-zoster Virus in Fujian Province,China,from 2018 to 2024
10
作者 Shijia Wu Zhifei Chen +5 位作者 Suhan Zhang Xiuhui Yang Hairong Zhang Weiyi Pan Yong Zhou Dong Li 《Biomedical and Environmental Sciences》 2026年第2期251-255,共5页
Varicella,a highly contagious respiratory infection caused by the varicella-zoster virus(VZV),predominantly affects children and is characterized by symptoms such as low-grade fever and vesicular rash[1,2].In China,va... Varicella,a highly contagious respiratory infection caused by the varicella-zoster virus(VZV),predominantly affects children and is characterized by symptoms such as low-grade fever and vesicular rash[1,2].In China,varicella remains prevalent,with a steady increase in incidence,peaking at 70.14 cases per 100,000 individuals in 2019[3].Although the number of reported outbreaks and cases from 2020 to 2022 was lower than those from 2006 to 2012 and 2013 to 2019,varicella continues to pose a significant public health challenge[3]. 展开更多
关键词 epidemiological characteristics varicella zoster virus public health challenge Fujian province population immunity China VARICELLA respiratory infection
暂未订购
ATLAS study:Design,athletic performance,and sex-specific regression models for muscle strength in the Greek population
11
作者 Natia A.Pogosova Despoina Brekou +7 位作者 Ioanna E.Gavra Efthymia A.Katsareli Eleni More Panagiotis G.Symianakis Maria Kafyra Ioanna Panagiota Kalafati Giannis Arnaoutis George V.Dedoussis 《Sports Medicine and Health Science》 2026年第1期79-95,共17页
Purpose:ATLAS is a cross-sectional study aiming to investigate environmental and genetic determinants of athletic performance in healthy Greek competitive athletes(CA).This article presents the study design,investigat... Purpose:ATLAS is a cross-sectional study aiming to investigate environmental and genetic determinants of athletic performance in healthy Greek competitive athletes(CA).This article presents the study design,investigates the muscle strength performance(MSP)of 289 adult and teenage CA,exercisers,and physically inactive individuals(PI),and proposes predictive models of MSP for adults.Methods:Muscle maximal,speed,and explosive strength(MMS/MSS/MES)at unilateral maximal concentric flexion and extension contraction(FC/EC)were evaluated using Biodex System 3 PRO^(TM)at 60°/s,180°/s,and 300°/s,while additional performance markers were assessed through field ergometric testing.Participants were interviewed about their lifestyle,dietary habits,physical activity,injury,and medical history.Body composition was assessed via bioelectrical impedance.gDNA was extracted from biochemical samples and then genotyped.Statistical analysis was conducted using IBM SPSS Statistics v21.0 and R.Results:Age,fitness,and sex impacted correlations of MSP with body composition and anthropometric measurements(p<0.05).Among CA,females outperformed males in accuracy(p<0.001)while,males outperformed females in anaerobic power,MSP,speed,and endurance(p<0.001).Adult CA outperformed exercisers and PI in MMS,MSS,and MES(p<0.05).Multiple linear regression models,with predictors age,FFM,body extremity,training load explained the majority of variation in MMS(R^(2)_(adj):71.4%–88.9%),MSS(R^(2)_(adj):64.8%–78.4%),and MES(R^(2)_(adj):52.7%–68.4%)at EC,FC,and their mean(p<0.001).Conclusions:Muscle-strengthening strategies should be customized according to individual fitness levels,body composition,and anthropometric measurements.The innovative sex-specific regression models assessing MMS,MSS,and MES at EC and FC provide a framework for personalizing rehabilitation and skill-specific training strategies. 展开更多
关键词 Athletic performance Isokinetic dynamometer Muscle strength performance Greek population Predictive models Body composition
在线阅读 下载PDF
Ignoring population differences in minimum mortality temperature substantially underestimates heat exposure and risk
12
作者 Jie Cao Weiqi Zhou Zheng Cao 《Ecological Frontiers》 2026年第1期135-144,共10页
Urban populations are increasingly exposed to extreme heat due to climate change and rapid urbanization,heightening health risks in cities worldwide.Accurate heat exposure assessment is essential for public health pla... Urban populations are increasingly exposed to extreme heat due to climate change and rapid urbanization,heightening health risks in cities worldwide.Accurate heat exposure assessment is essential for public health planning and risk reduction.Most existing approaches rely on a single threshold temperature(e.g.,35℃of daily max temperature),applied uniformly to the entire population.However,this one-size-fits-all assumption overlooks substantial differences in heat sensitivity across population subgroups.In this study,we address this limitation by quantifying subgroup-specific temperature-mortality relationships and using corresponding minimum mortality temperatures(MMTs)to assess heat exposure.Results show that the population-wide MMT was 27.5℃,but it varied greatly across population subgroups.The elderly population(≥65)had an MMT of 24.6℃,much lower than the 28.6℃observed in younger individuals(<65).Females also exhibited a lower MMT that males(25℃versus 28.2℃).However,educational attainment did not significantly affect MMT.Using a uniform MMT resulted in substantial underestimation of heat exposure,ranging from 25.3%in 1990 to 13.9%in 2020,reflecting demographic shifts over time.Spatially,nearly half of the city experienced underestimated heat risk,especially in central and northeastern regions where heat-vulnerable populations are concentrated.These findings underscore the need for more nuanced heat exposure assessments that account for demographic and spatial variability,paving the way for targeted public health interventions to protect the most vulnerable urban populations. 展开更多
关键词 Heat exposure Heat risk population difference Minimum mortality temperature Mortality burden
在线阅读 下载PDF
Differences in cynomolgus macaque populations used for infectious disease research
13
作者 Darcy Quist Kimimuepigha Ebisine +2 位作者 Emma Kennedy Stuart Dowall Mike Dennis 《Animal Models and Experimental Medicine》 2026年第2期298-307,共10页
Cynomolgus macaques,a species of Old World primate native to southeastern and eastern Asia and the island of Mauritius,are one of the most important nonhuman primate models for infectious disease.Although the closely ... Cynomolgus macaques,a species of Old World primate native to southeastern and eastern Asia and the island of Mauritius,are one of the most important nonhuman primate models for infectious disease.Although the closely related rhesus macaque is classified into subspecies based on geographic origin,no such subdivision exists for cynomolgus macaques,and they continue to be used interchangeably in infectious disease research,reducing the comparability of data produced from these studies.Research into the population genetics of cynomolgus macaques has found significant differences between macaques native to different areas,including their genetic diversity,with macaques from insular populations such as Mauritius and the Philippines exhibiting highly restricted heterozygosity compared to mainland populations native to Indonesia or Cambodia.In the context of infectious disease studies,research into pathogens,including Ebola virus,Crimean-Congo hemorrhagic fever virus,and Mycobacterium tuberculosis have found differences in study outcomes,survival times,and immune cell responses between different populations of macaques.This review provides an overview of the differences between cynomolgus macaque populations in the context of genetic diversity,and in response to infection,and highlights the need for clear reporting of geographic origin of primates used in research.This will improve data comparison between studies and help to further refine this important animal model. 展开更多
关键词 animal models communicable diseases genetic variation Macaca fascicularis population genetics
暂未订购
Ecosystem management and agricultural green development in subtropical regions
14
作者 Jinshui Wu Tony G.O’Donnell +4 位作者 Andrew Macrae Hongsong Chen Weiguo Cheng Zhihong Xu Zhengmiao Deng 《Journal of Integrative Agriculture》 2026年第2期399-401,共3页
The United Nations Sustainable Development Goal(SDG) 2 aims to achieve Zero Hunger by 2030.However,global hunger and food insecurity have continued to rise at an alarming rate(UN 2023).Subtropical regions are home to ... The United Nations Sustainable Development Goal(SDG) 2 aims to achieve Zero Hunger by 2030.However,global hunger and food insecurity have continued to rise at an alarming rate(UN 2023).Subtropical regions are home to more than 30% of the world's population,predominantly in developing countries where per capita farmland and food supply are only 40% of those in developed nations(FAO 2018).Meeting the Zero Hunger target amid ongoing population growth in these regions requires a substantial increase in agricultural production while minimizing soil degradation and adverse ecological impacts.This challenge is shared by many countries across South Asia,Africa,and Central and South America. 展开更多
关键词 ecosystem management developing countries subtropical regions sustainable development goal agricultural green development zero hunger sustainable development goal sdg population growth
在线阅读 下载PDF
Long-term Mechanism and Implementation Path of Increasing Income of Rural Low-income Population in Zhejiang Province from the Perspective of Common Prosperity
15
作者 Peiyi YE 《Asian Agricultural Research》 2026年第2期23-26,共4页
Taking the rural low-income population of Zhejiang Province as its subject, this paper examines how to build a sustainable income-growth mechanism and identify feasible implementation paths within the context of the c... Taking the rural low-income population of Zhejiang Province as its subject, this paper examines how to build a sustainable income-growth mechanism and identify feasible implementation paths within the context of the common prosperity strategy. The research identifies key obstacles to income expansion, including an undiversified industrial structure, insufficient human capital, and a lack of robust social protection. These call for systemic solutions featuring institutional innovation, resource consolidation, and capability enhancement. Building on Zhejiang's experience as a common prosperity demonstration zone, the article constructs an integrated framework centered on four pillars: industrial empowerment, education upgrading, social security reinforcement, and digital coordination. It further offers concrete policy proposals involving the cultivation of localized industries, vocational skill training, enhanced safety nets, and the adoption of digital tools. The study thus offers both theoretical insights and practical paradigms for tackling the challenge of raising incomes in low-income rural areas. 展开更多
关键词 Common prosperity Rural low-income population Long-term mechanism of increasing income Implementation path Zhejiang Province
在线阅读 下载PDF
Coronal plane alignment of the knee phenotypes and ankle joint coronal plane alignment patterns in Egyptian population
16
作者 Ahmed A Khalifa Mohamed Moustafa +3 位作者 Shikuria Lemma Mostafa Fayez Ahmed M Abdelaal Amr A Fadle 《World Journal of Orthopedics》 2026年第1期67-80,共14页
BACKGROUND In an era leaning toward a personalized alignment of total knee arthroplasty,coronal plane alignment of the knee(CPAK)phenotypes for each population are studied;furthermore,other possible variables affectin... BACKGROUND In an era leaning toward a personalized alignment of total knee arthroplasty,coronal plane alignment of the knee(CPAK)phenotypes for each population are studied;furthermore,other possible variables affecting the alignment,such as ankle joint alignment,should be considered.AIM To determine CPAK distribution in the North African(Egyptian)population with knee osteoarthritis and to assess ankle joint line orientation(AJLO)adaptations across different CPAK types.METHODS A cross-sectional study was conducted on patients with primary knee osteoarthritis and normal ankle joints.Radiographic parameters included the mechanical lateral distal femoral angle,medial proximal tibial angle,and the derived calculations of joint line obliquity(JLO)and arithmetic hip-knee-ankle angle(aHKA).The tibial plafond horizontal angle(TPHA)was used for AJLO assessment,where 0°is neutral(type N),<0°is varus(type A),and>0°is valgus(type B).The nine CPAK types were further divided into 27 subtypes after incorporating the three AJLO types.RESULTS A total of 527 patients(1054 knees)were included for CPAK classification,and 435 patients(870 knees and ankles)for AJLO assessment.The mean age was 57.2±7.8 years,with 79.5%females.Most knees(76.4%)demonstrated varus alignment(mean aHKA was-5.51°±4.84°)and apex distal JLO(55.3%)(mean JLO was 176.43°±4.53°).CPAK types I(44.3%),IV(28.6%),and II(10%)were the most common.Regarding AJLO,70.2%of ankles exhibited varus orientation(mean TPHA was-5.21°±6.45°).The most frequent combined subtypes were CPAK type I-A(33.7%),IV-A(21.5%),and I-N(6.9%).A significant positive correlation was found between the TPHA and aHKA(r=0.40,P<0.001).CONCLUSION In this North African cohort,varus knee alignment with apex distal JLO and varus AJLO predominated.CPAK types I,IV,and II were the most common types,while subtypes I-A,IV-A,and I-N were commonly occurring after incorporating AJLO types;furthermore,the AJLO was significantly correlated to aHKA. 展开更多
关键词 Coronal plane alignment of the knee classification Coronal alignment Ankle joint alignment Knee arthroplasty Knee replacement North African population
暂未订购
Genetic diversity and population structure of the Fujian oyster Crassostrea angulata revealed by mitochondrial COI gene and nuclear gene ITS2 sequences
17
作者 Shiqi YU Ziqiang HAN Huayong QUE 《Journal of Oceanology and Limnology》 2026年第1期419-432,共14页
The Fujian oyster(Crassostrea angulata) is an economically significant shellfish species distributed mainly along the Fujian coast, Southeast China. However, its genetic diversity and structure remain unclear. The mai... The Fujian oyster(Crassostrea angulata) is an economically significant shellfish species distributed mainly along the Fujian coast, Southeast China. However, its genetic diversity and structure remain unclear. The main distribution area of the C. angulata is located in Fujian, South China. In total, 420 C. angulata were collected from 14 natural habitats(populations) along the Fujian coast, and their genetic diversity and structure were analyzed in the mitochondrial COI and nuclear gene ITS2 sequences. Results reveal that all the 14 populations of C. angulata exhibited high levels of genetic diversity, with a total of 57(haplotype diversity: 0.811±0.016) and 124(haplotype diversity: 0.912±0.007) haplotypes revealed by COI and ITS2, respectively. Notably, significant intermediate level of genetic differentiations between the Ningde Zhujiang(ZJ) population(FS T by COI: 0.035–0.142, P<0.05;FS T by ITS2: 0.078–0.123, P<0.05) with other populations were observed for the first time, which is also supported by the results of molecular variance analysis(FC T by COI: 0.105, P<0.05;FC T by ITS2: 0.086, P<0.05) and the clustering of the ZJ population into distinct branches in the interpopulation genetic differentiation tree. Furthermore, the evolutionary tree and haplotype network analyses do not support the formation of a clear geographical genealogical structure among these 14 populations. In addition, the population dynamics analysis suggests that the C. angulata may have undergone expansion during the third ice age of the Pleistocene. These results provide a reference for the preservation and further genetic improvement of C. angulata. 展开更多
关键词 Crassostrea angulata genetic diversity population structure mitochondrial COⅠgene nuclear gene ITS2 sequence
在线阅读 下载PDF
Using novel microsatellite markers to characterize genetics of asexual sea cucumber Stichopus chloronotus populations in tropical nearshore islands of the South China Sea
18
作者 Xiang HU Xinxin HUANG +3 位作者 Mengjiao LIU Linwen HE Fei GAO Qiang XU 《Journal of Oceanology and Limnology》 2026年第1期219-233,共15页
Stichopus chloronotus is a tropical sea cucumber with facultative asexual reproduction in the Indo-Western Pacific,yet its wild populations are decreasing due to extensive harvesting.Understanding the species’genetic... Stichopus chloronotus is a tropical sea cucumber with facultative asexual reproduction in the Indo-Western Pacific,yet its wild populations are decreasing due to extensive harvesting.Understanding the species’genetic characteristics is essential for effective management and conservation.To develop novel microsatellite markers and assess the genetic diversity,clonality,and genetic structure of eight populations of S.chloronotus in the South China Sea,193 individuals from eight populations across Wuzhizhou and Fenjiezhou(Boundary)islands were analyzed using nine newly developed microsatellite markers and five previously established markers.RNA-Seq was employed to obtained 62662 unigenes and identified 16926 microsatellite loci.Fourteen polymorphic microsatellite loci were developed,of which 11 were highly polymorphic(polymorphic information content>0.5).The number of alleles(N_(a))ranged from 3 to 6 per locus,and the average Shannon diversity index(I)was 1.107.All the populations exhibited asexual reproduction,with regional variations in reproductive modes.Asexual reproduction was predominant in the northwestern Wuzhizhou Island population(SY 7)and the Fenjiezhou Island population(LS 8),where four and five predominant clones represented more than 89%of the individuals,which led to reduced genetic diversity.Overall,genetic diversity was moderately low,with significant genetic differentiation among populations(F_(ST)=0.33;P<0.001),suggesting limited gene flow(the number of migrants(N_(m))<1).These findings highlight the role of reproductive strategies in shaping fine-scale genetic differentiation in S.chloronotus.The limited recruitment success of sexually produced larvae and habitat heterogeneity likely constrain clone dispersal,contributing to distinct genetic restructuring.This study provided key insights into the interplay between reproductive strategies and genetic patterns in sea cucumbers,offering a scientific basis for targeted conservation efforts. 展开更多
关键词 Stichopus chloronotus microsatellite marker(SSR) population genetic diversity asexual reproduction
在线阅读 下载PDF
Molecular phylogeography and population history of Saccostrea mordax based on mitochondrial DNA
19
作者 Zeyu TANG Cui LI +3 位作者 Guochen ZANG Zhenqiang LIU Zongmei CUI Haiyan WANG 《Journal of Oceanology and Limnology》 2026年第1期357-371,共15页
The Saccostrea mordax Gould,1850 is a typical intertidal species,whose genetic differentiation is influenced by various factors,including geological and climatic changes.To explore the genetic structure and historical... The Saccostrea mordax Gould,1850 is a typical intertidal species,whose genetic differentiation is influenced by various factors,including geological and climatic changes.To explore the genetic structure and historical population characteristics of Saccostrea mordax,we sequenced the mitochondrial cytochrome c oxidase subunit I(COI)gene from 58 specimens sampled from four locations in the western Pacific.Additionally,103 individuals from the Persian Gulf and western Pacific(from databases)were included for phylogenetic analysis.The Bayesian Inference tree showed that all specimens were divided into two clades,i.e.,the Persian Gulf population and the western Pacific population.Spatial molecular variance analysis indicated significant genetic differentiation between the two populations,and isolation by distance analysis revealed a positive correlation between genetic differentiation and geographic distance.Neutrality tests and Bayesian Skyline Plot suggested that both populations underwent expansions during the late Pleistocene.This study revealed the population history of Saccostrea mordax and described a new lineage,Saccostrea mordax lineage D,providing a foundation for understanding oyster biodiversity formation and genetic resource conservation. 展开更多
关键词 Saccostrea mordax cytochrome c oxidase subunit I(COI) genetic structure population expansion Saccostrea mordax lineage D
在线阅读 下载PDF
Increasing meridional disparity of population exposure to heat stress
20
作者 Xiaofan Xu Yuxiao Kong +5 位作者 Jintao Zhang Jianping Duan Minghong Tan Xue Yang Hongzhou Zhu Deliang Chen 《Geography and Sustainability》 2026年第1期95-105,共11页
Global warming and socioeconomic development are expected to exacerbate human exposure to heat stress,but the extent and inequality of such changes remain unclear.Here,we quantified the future population exposure to h... Global warming and socioeconomic development are expected to exacerbate human exposure to heat stress,but the extent and inequality of such changes remain unclear.Here,we quantified the future population exposure to heat stress(PEHS)under different Shared Socioeconomic Pathways(SSPs)and Representative Concentration Pathways(RCPs)scenarios using a novel decomposition framework that separates the contributions of climate change,population change,and their interaction.Results show that global PEHS will increase substantially during the 21st century,with low-latitude regions experiencing the largest absolute increases,and high-latitude regions facing the largest relative increases.Globally,projected increases in PEHS under SSP3-7.0 are roughly three times those under SSP1-2.6,with low latitudes contributing about 70%-75%of the global total.SSP1-2.6 most effectively limits future heat exposure,with the highest risks in low-latitude developing regions,underscoring the need for low-emission pathways and targeted population and urbanization management.The findings highlight the urgent need for both climate mitigation and population adaptation strategies to address the growing and uneven heat exposure risks worldwide. 展开更多
关键词 population exposure Extreme heatwave Meridional disparity
在线阅读 下载PDF
上一页 1 2 188 下一页 到第
使用帮助 返回顶部