population dynamics

人口动态
  • 文章类型: Journal Article
    Climate change is increasing the proportion of river networks experiencing flow intermittence, which in turn reduces local diversity (i.e., α-diversity) but enhances variation in species composition among sites (i.e., β-diversity), with potential consequences on ecosystem stability. Indeed, the multiscale theory of stability proposes that regional stability can be attained not only by local processes but also by spatial asynchrony among sites. However, it is still unknown whether and how scale-dependent changes in biodiversity associated with river flow intermittence influence stability across spatial scales. To elucidate this, we here focus on multiple metacommunities of French rivers experiencing contrasting levels of flow intermittence. We clearly show that the relative contribution of spatial asynchrony to regional stability was higher for metacommunities of intermittent than perennial rivers. Surprisingly, spatial asynchrony was mainly linked to asynchronous population dynamics among sites, but not to β-diversity. This finding was robust for both truly aquatic macroinvertebrates and for taxa that disperse aerially during their adult stages, implying the need to conserve multiple sites across the landscape to attain regional stability in intermittent rivers. By contrast, metacommunities of truly aquatic macroinvertebrates inhabiting perennial rivers were mainly stabilized by local processes. Our study provides novel evidence that metacommunities of perennial and intermittent rivers are stabilized by contrasting processes operating at different spatial scales. We demonstrate that flow intermittence enhances spatial asynchrony among sites, thus resulting in a regional stabilizing effect on intermittent river networks. Considering that climate change is increasing the proportion of intermittent rivers worldwide, our results suggest that managers need to focus on the spatial dynamics of metacommunities more than on local-scale processes to monitor, restore, and conserve freshwater biodiversity.
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  • 文章类型: Journal Article
    Temporal environmental noise (EN) is a prevalent natural phenomenon that controls population and community dynamics, shaping the destiny of biological species and genetic types. Conventional theoretical models often depict EN as a Markovian process with an exponential distribution of correlation times, resulting in two distinct qualitative dynamical categories: quenched (long environmental timescales) and annealed (short environmental timescales). However, numerous empirical studies demonstrate a fat-tailed decay of correlation times. Here we study the consequences of power-law correlated EN on the dynamics of isolated and competing populations. We analyze the intermediate region that lies between the quenched and annealed regimes and show that it can widen indefinitely. Within this region, dynamics is primarily driven by rare, yet not exceedingly rare, long periods of almost-steady environmental conditions. For an isolated population, the time to extinction in this region exhibits a power-law scaling with the logarithm of the abundance and also a nonmonotonic dependence on the spectral exponent.
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  • 文章类型: Journal Article
    作为全球椰子产业的重大挫折,致命性黄化病(LYD),由植物浆体引起,继续威胁着美洲的椰子树,加勒比海,非洲,和大洋洲。尽管有经济影响,LYD向量上存在有限的信息,这阻碍了疾病的预防和管理。使用双面黄色粘性陷阱,我们研究了影响LYD的三种吸液昆虫的季节丰度和种群动态的因素,即,Diostrombus(半翅目:Derbidae)sp。和Patarasp.(半翅目:Derbidae),和NedoptepacurtaDmitriev(半翅目:Cicadellidae),关于五种椰子基因型(斯里兰卡绿矮人(SGD),瓦努阿图高个子(VTT),SGD×VTT,马来亚黄矮人(MYD)×VTT,和西部地区的西非高个子(WAT)),以及2019年4月至2021年5月在加纳中部地区的一个(SGD)。结果表明,N.curta和Patarasp。是西部和中部地区最丰富的物种,分别。椰子品种和吸汁昆虫之间存在显着差异。在干旱季节,所有采样地点的所有椰子基因型都记录了吸汁昆虫的种群发育高峰。在温度与N.corta和Patarasp的种群之间检测到显着正相关。在AgonaNkwanta,VTT的N.Curta人口最多,而WAT的Patarasp人口最高。和Diostrombussp.这些发现为评估可能影响圣保罗角威尔特病病理系统的因素的作用提供了有用的信息。
    As a major setback to the global coconut industry, lethal yellowing disease (LYD), caused by phytoplasmas, continues to threaten coconut palms in the Americas, the Caribbean, Africa, and Oceania. Despite its economic impacts, limited information exists on LYD vectors, which impedes the prevention and management of the disease. Using double-sided yellow sticky traps, we investigate the factors that influence the seasonal abundance and population dynamics of three sap-sucking insects of LYD, i.e., Diostrombus (Hemiptera: Derbidae) sp. and Patara sp. (Hemiptera: Derbidae), and Nedoptepa curta Dmitriev (Hemiptera: Cicadellidae), on five coconut genotypes (Sri Lanka Green Dwarf (SGD), Vanuatu Tall (VTT), SGD × VTT, Malayan Yellow Dwarf (MYD) × VTT, and West African Tall (WAT)) in the Western Region, and one (SGD) in the Central Region of Ghana from April 2019 to May 2021. The results showed that N. curta and Patara sp. were the most abundant species in the Western and Central Regions, respectively. There was a significant difference between the coconut cultivars and sap-sucking insects. The peak population development of the sap-sucking insects was recorded during the dry season on all the coconut genotypes at all sampling locations. A significant positive correlation was detected between temperature and the population of N. curta and Patara sp. In the Agona Nkwanta, VTT had the highest population of N. curta, whereas WAT had the highest population of Patara sp. and Diostrombus sp. These findings provide useful information for assessing the role of factors that could affect the Cape Saint Paul Wilt disease pathosystem.
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  • 文章类型: Journal Article
    缅因湾(GoM)是世界海洋中变暖最快的地区之一。一些物种的分布变化已经被记录在案,特别是对于商业上重要的物种。对目前尚未开发但将来可能会开发的物种知之甚少。作为对这些问题的案例研究,我们专注于lumpfish(Cyclopteruslumpus),因为人们认识到并及时需要了解野生lumpfish种群动态,以支持可持续的渔业和水产养殖发展。使用来自五个不同的渔业依赖和独立调查的发生数据,我们检查了GoM中块状鱼随时间的分布。我们发现,秋天更有可能出现块状鱼,并且与较深的水域和较冷的底部温度相关。自1980年以来,龙鱼的存在随着时间的推移而增加,并向北转移。给定一组有限的数据,这些发现应谨慎解释,因为需要额外的工作来评估肿块鱼的实际分布是否正在发生变化。然而,我们的工作为资源管理人员提供了初步信息,以确保可持续地收获龙鱼,用于紧急龙鱼水产养殖设施。
    The Gulf of Maine (GoM) is one of the fastest-warming parts of the world\'s oceans. Some species\' distributional shifts have already been documented, especially for commercially-important species. Less is known about species that are not currently exploited but may become so in the future. As a case study into these issues, we focus on lumpfish (Cyclopterus lumpus) because of the recognized and timely need to understand wild lumpfish population dynamics to support sustainable fisheries and aquaculture developments. Using occurrence data from five different fisheries-dependent and independent surveys, we examined lumpfish distribution over time in the GoM. We found that lumpfish presence was more likely in Fall and correlated with deeper waters and colder bottom temperatures. Since 1980, lumpfish presence has increased over time and shifted north. Given a limited set of data, these findings should be interpreted with caution as additional work is needed to assess if the actual distribution of lumpfish is changing. Nevertheless, our work provides preliminary information for resource managers to ensure that lumpfish are harvested sustainably for use in emergent lumpfish aquaculture facilities.
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  • 文章类型: Dataset
    南极半岛的快速气候变暖正在推动区域人口下降和捕食者和猎物的分布变化。受影响的物种包括南极海豹和南象海豹,所有这些都依赖于半岛地区的生命周期的关键阶段。然而,在这个偏远地区,数据收集很困难,因此,用于识别和调查这些物种种群趋势的长期时间序列很少见。我们提供了ShirreffPhocidCapeCensus(CS-PHOC)数据集:每周的phocids计数(crabeater,豹子,南象,和Weddell海豹)在Shirreff角被拖走,利文斯顿岛,自1997年以来的大多数南方夏季。这些人口普查的数据被清理和汇总,从23个野外季节的284次人口普查中获得了稳健和可比的计数数据。CS-PHOC数据集,可通过SCAR生物多样性门户网站公开获得,将每年更新,以提供有关南极半岛南大洋台风的重要信息。
    Rapid climatic warming of the Antarctic Peninsula is driving regional population declines and distribution shifts of predators and prey. Affected species include Antarctic ice seals and the southern elephant seal, all of which rely on the peninsula region for critical stages of their life cycle. However, data collection is difficult in this remote region, and therefore long-term time series with which to identify and investigate population trends in these species are rare. We present the Cape Shirreff Phocid Census (CS-PHOC) dataset: weekly counts of phocids (crabeater, leopard, southern elephant, and Weddell seals) hauled out at Cape Shirreff, Livingston Island, during most austral summers since 1997. Data from these censuses were cleaned and aggregated, resulting in robust and comparable count data from 284 censuses across 23 field seasons. The CS-PHOC dataset, which is publicly available through the SCAR Biodiversity Portal, will be updated yearly to provide important information about Southern Ocean phocids in the Antarctic Peninsula.
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  • 文章类型: Journal Article
    背景:与亲密的兄弟姐妹分开并在早年离开父母的家是青少年的重大生活事件(反映在双胞胎分开时的年龄),并可能使他们心理健康状况不良。这项研究旨在研究青春期后期和成年后期的抑郁症状与分离年龄和居住活动之间的关系,并探讨可能的潜在遗传影响。
    方法:居住移动性包括17岁之前的移动次数和总距离。根据FinnTwin12队列的3071对双胞胎,我们使用线性回归评估了分居年龄和居住流动性与17岁和成年青年时的一般行为量表(GBI)评分的相关性.较高的GBI评分表明更多的抑郁症状发生。然后,重复测量混合模型(MMRM)用于可视化分数轨迹并测试关联,控制“基线”状态。在GBI得分差异之间进行了双变量交叉滞后路径模型的双分析,在cotwin之间,和分离状态对潜在的遗传影响。
    结果:与17岁之前分离的双胞胎相比,后来分离的双胞胎在17岁和成年后的GBI得分明显较低。在MMRM中,年龄越晚的分离和移动次数越多,青年期GBI评分越高.检测到很小的遗传效应,其中17岁时的GBI配对差异与22岁之前的分离状态有关(系数:0.01)。
    结论:该研究提供了有关兄弟姐妹和家庭对青春期后期和成年后抑郁症状的影响的有效证据,同时发现了一些反向效应的证据。这表明在解释结果时更加谨慎。确认了居住活动和抑郁症状之间的强烈关联,尽管还需要进一步的详细研究。
    BACKGROUND: Separating with close siblings and leaving the parental home at an early age represents a major life event for an adolescent (reflected by age at separation in a twin pair) and may predispose them to poor mental health. This study aims to examine the association of age at separation and residential mobility on depressive symptoms in late adolescence and young adulthood and to explore possible underlying genetic effects.
    METHODS: Residential mobility consisted of the number and total distance of moves before age 17. Based on 3071 twins from the FinnTwin12 cohort, we used linear regression to assess the association of age at separation and residential mobility with General Behavior Inventory (GBI) scores at age 17 and in young adulthood. A higher GBI score indicated more depressive symptoms occurred. Then, the mixed model for repeated measures (MMRM) was used to visualize the scores\' trajectory and test the associations, controlling for \"baseline\" state. Twin analyses with a bivariate cross-lagged path model were performed between the difference in GBI scores, between cotwins, and separation status for the potential genetic influence.
    RESULTS: Compared to twins separated before age 17, twins who separated later had significantly lower GBI scores at age 17 and in young adulthood. In MMRM, separation at a later age and a higher number of moves were associated with a higher GBI score in young adulthood. A small genetic effect was detected wherein GBI within-pair differences at age 17 were associated with separation status before age 22 (coefficient: 0.01).
    CONCLUSIONS: The study provides valid evidence about the influence of siblings and family on depressive symptoms in later adolescence and young adulthood while finding some evidence for a reverse direction effect. This suggests more caution in the interpretation of results. A strong association between residential mobility and depressive symptoms was affirmed, although further detailed research is needed.
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  • 文章类型: Journal Article
    尽管进行了广泛的考古研究,我们对上旧石器时代欧洲人口历史的了解仍然有限,主要是由于化石残骸的稀缺可用性和较差的分子保存。由于牙齿在化石记录中占据主导地位,并在形态中保留了遗传特征,我们编制了一个大型数据集,包含大约47到7千年前的450个牙列(ka),数量超过现有的骨骼和古遗传数据集。我们使用基于合并的机器学习近似贝叶斯计算(ABC)框架测试了一系列竞争的人口统计场景,我们修改了该框架以用于表型数据。大多数情况下是同意的,但也挑战了一些迄今可用的证据,我们确定西欧的人口流动约为28ka,西部和东部避难所的分离株在~28和14.7ka之间,和瓶颈在最后一次冰川的最大值。方法上,这项研究标志着ABC在骨骼表型中的开创性应用,为令人兴奋的未来研究途径铺平道路。
    Despite extensive archaeological research, our knowledge of the human population history of Upper Paleolithic Europe remains limited, primarily due to the scarce availability and poor molecular preservation of fossil remains. As teeth dominate the fossil record and preserve genetic signatures in their morphology, we compiled a large dataset of 450 dentitions dating between ~47 and 7 thousand years ago (ka), outnumbering existing skeletal and paleogenetic datasets. We tested a range of competing demographic scenarios using a coalescent-based machine learning Approximate Bayesian Computation (ABC) framework that we modified for use with phenotypic data. Mostly in agreement with but also challenging some of the hitherto available evidence, we identified a population turnover in western Europe at ~28 ka, isolates in western and eastern refugia between ~28 and 14.7 ka, and bottlenecks during the Last Glacial Maximum. Methodologically, this study marks the pioneering application of ABC to skeletal phenotypes, paving the way for exciting future research avenues.
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  • 文章类型: Journal Article
    棉花或solenopsismealybug,prophenacoccussolenopsis(Tinsley,1898)(半翅目:假球菌科),在埃及感染各种寄主植物。进行了一项研究,以观察麦虫的发生率以及气象变量和植物年龄对Esna地区玉米(单杂交168个黄色玉米品种)植物昆虫种群的可能影响,卢克索省,埃及,连续两个赛季(2021年和2022年)。P.solenopsis侵染玉米植物从6月的第3周到收获,并且有三个季节性发病/季节的高峰;在6月的第1周和7月的第3/4周,8月的第二周。同样,每个季节的侵染百分比有三个高峰。在第一个赛季,每个样本的平均种群密度为174.04±16.93个个体,在第二季,156.72±14.28人。最有利的气候条件是,在第一个季节的8月和第二个季节的9月,而6月在两个生长季节都不太合适(根据每周调查估计)。天气条件和植物年龄的综合影响与P.solenopsis种群的估计显着相关,解释方差(E.V.)为93.18和93.86%,分别,在两个季节。此外,它们的影响解释了93.30和95.54%的侵染百分比差异,分别,在两个季节。玉米的植株年龄是决定每个季节紫杉种群密度变化的最有效因素。第一个季节的平均日最低温度和第二个季节的平均日露点是影响侵染百分比变化的最重要因素。然而,在两个季节,平均每日最高温度是人口和感染变化中最小的有效变量。这项研究为监测和早期发现玉米中的粉虱铺平了道路;以及其发育的最佳气候条件。
    The cotton or solenopsis mealybug, Phenacoccus solenopsis (Tinsley, 1898) (Hemiptera: Pseudococcidae), infests various host plants in Egypt. A study was conducted to observe the incidence of mealybugs and the possible influences of meteorological variables and plant age on the insect population of maize (single-hybrid 168 yellow maize cultivar) plants in Esna district, Luxor governorate, Egypt, in two consecutive seasons (2021 and 2022). P. solenopsis infested maize plants from the 3rd week of June to harvest, and had three peaks of seasonal incidence/season namely; in the 1st week of June in the 3rd/4th week of July, and the 2nd week of August. Similarly, there were three peaks in the percent of infestations per season. In the first season, the average population density of P. solenopsis per sample was 174.04 ± 16.93 individuals, and in the second season, 156.72 ± 14.28 individuals. The most favorable climate for P. solenopsis population increase and infestation occurred in August in the first season and in September in the second season, while June was less suitable in both growing seasons (as estimated by weekly surveys). The combined effects of weather conditions and plant age are significantly related to the estimates of P. solenopsis populations, with an explained variance (E.V.) of 93.18 and 93.86%, respectively, in the two seasons. In addition, their influences explained differences in infestation percentages of 93.30 and 95.54%, respectively, in the two seasons. Maize plant age was the most effective factor in determining changes in P. solenopsis population densities in each season. The mean daily minimum temperature in the first season and mean daily dew point in the second season were the most important factors affecting the percent changes in infestation. However, in both seasons, the mean daily maximum temperature was the least effective variable in population and infestation variation. This study paves the way for monitoring and early detection of mealybugs in maize; as well as the optimal climatic conditions for its development.
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  • 文章类型: Journal Article
    人口增长加上对电能的需求,导致圣保罗州建设了数百座水力发电厂,巴西。这些干预措施的后果是河流的支离破碎,形成障碍,阻碍迁徙鱼类的流动性,对这些物种的生命周期产生影响,尤其是在饲养区和饲养区之间的运动。出于这个原因,本文旨在评估有关大坝的最新知识,自由伸展,以及圣保罗州及其支流的三个主要流域的迁徙物种。通过对2003年至2023年的系统评价,共获得89篇文章,其中48个是关于水坝的,5解决了鱼类换位系统,和36个描绘迁徙物种。在上半场,研究更多地集中在水坝对鱼类动物的影响上,而在研究的后半部分,对洄游鱼类的研究占主导地位。大多数研究是在主要河流中进行的,支流中很少。最后,16种迁徙物种,考虑到长距离,被研究过,研究最多的是P.lineatus,P.maculatus,L.Friderici,obtusidens和S.hilarri以及在河流中最常见的是Prochiloduslineatus,斑毛虫,巨大孢子虫和沙门氏菌。因此,我们建议维持圣保罗州主要河流和支流中仍然存在的自然流态,以维持所库存物种的健康种群。
    Population growth combined with the need for electrical energy resulted in the construction of hundreds of hydroelectric plants in the state of São Paulo, Brazil. The consequence of these interventions was the fragmentation of rivers, forming barriers, that hinder the mobility of migratory fish species, generating an impact on the life cycle of these species, especially about movement between breeding and feeding areas. For this reason, this article aimed to evaluate the state-of-the-art knowledge regarding dams, free stretches, and migratory species in the three main river basins of the state of São Paulo and its tributaries. Through a systematic review from 2003 to 2023, 89 articles were obtained, 48 of which were about dams, 5 which addressed fish transposition systems, and 36 portraying migratory species. In the first half, research focused more on the impacts of dams on fish fauna, while in the second half of the period studied, studies of migratory fish were dominant. Most research was conducted in the main rivers, with few in the tributaries. Finally, 16 migratory species, considered long-distance, were studied, the most studied being P. lineatus, P. maculatus, L. friderici, M. obtusidens and S. hilarri and the ones that occurred most frequently in rivers are Prochilodus lineatus, Pimelodus maculatus, Megaleporinus obtusidens and Salminus hilarii. Therefore, we recommend maintaining the natural flow regime that still exists in the main rivers and tributaries of the state of São Paulo, to maintain healthy populations of the inventoried species.
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    文章类型: Journal Article
    The article presents a comparative analysis of the process of population aging in the context of demographic and professional risks of depopulation among working population in Russia. The values of the main medical and demographic indicators of population aging for Russia and developed countries were given. The results of UN forecasts, probabilistic forecasts of the total number and some characteristics of the age-sex structure for the population of the Russian Federation were analyzed. The state of demographic disadvantage in Russia and in the world was convincingly shown. Particular attention was paid to the consideration of the demographic risks of a reduction in the working-age population and an increase in the burden on the working-age population. The need for further research on the use of geroprotectors and modern gerontotechnologies as means and methods for preventing premature decline in work ability, slowing down the aging process of workers, reducing the mortality rate among working population and increasing professional longevity has been proven.
    В статье представлен сравнительный анализ процесса старения населения в контексте демографических и профессиональных рисков депопуляции работающего населения в России. Приведены основные медико-демографические показатели старения населения для России и развитых стран. Проанализированы результаты прогнозов ООН, вероятностных прогнозов общей численности и ряда характеристик структуры по возрасту и полу для населения РФ. Убедительно показано состояние демографического неблагополучия в России и мире. Особое внимание уделено рассмотрению демографических рисков сокращения численности населения в рабочих возрастах, увеличению нагрузки на трудоспособное население. Доказана необходимость дальнейших исследований, посвященных использованию геропротекторов и современных геронтотехнологий в качестве средств и методов профилактики преждевременного снижения профессиональной работоспособности, замедления процессов старения организма работающих, снижения уровня смертности трудоспособного населения и увеличения профессионального долголетия.
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