Spatial heterogeneity

空间异质性
  • 文章类型: Journal Article
    地理加权回归(GWR)是一种可以捕获空间异质性影响的局部统计模型。该模型可用于单变量和多变量响应。然而,应该注意的是,GWR模型需要误差正态的假设。为了克服这个问题,我们提出了一个广义伽马分布响应的GWR模型,该模型可以捕获某些特殊的连续分布现象。所提出的模型被称为地理加权多变量广义伽马回归(GWMGGR)。使用Bernt-Hall-Hall-Haussman(BHHH)算法优化的最大似然估计(MLE)方法进行参数估计。为了确定空间异质性效应的重要性,使用最大似然比检验(MLRT)方法进行假设检验.我们使用k均值聚类方法根据每个响应的估计模型参数进行了空间聚类,以解释获得的结果。所提出的方法的一些亮点是:•具有多变量广义伽马分布响应的GWR的新模型,以克服正态分布误差的假设。•拟合优度测试,以测试GWMGGR模型中的空间效应。•基于三个教育指标的中爪哇地区/城市的空间聚类。
    Geographically Weighted Regression (GWR) is one of the local statistical models that can capture the effects of spatial heterogeneity. This model can be used for both univariate and multivariate responses. However, it should be noted that GWR models require the assumption of error normality. To overcome this problem, we propose a GWR model for generalized gamma distributed responses that can capture the phenomenon of some special continuous distributions. The proposed model is known as Geographically Weighted Multivariate Generalized Gamma Regression (GWMGGR). Parameter estimation is performed using the Maximum Likelihood Estimation (MLE) method optimized with the Bernt-Hall-Hall-Haussman (BHHH) algorithm. To determine the significance of the spatial heterogeneity effect, a hypothesis test was conducted using the Maximum Likelihood Ratio Test (MLRT) approach. We made a spatial cluster based on the estimated model parameters for each response using the k-means clustering method to interpret the obtained results. Some highlights of the proposed method are:•A new model for GWR with multivariate generalized gamma distributed responses to overcome the assumption of normally distributed errors.•Goodness of fit test to test the spatial effects in GWMGGR model.•Spatial clustering of districts/cities in Central Java based on three dimensions of educational indicators.
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  • 文章类型: Journal Article
    树木暴露于显著的时空热变化,这可能会导致一次和二次生长的发生和动力学出现冠内差异。近几十年来,已观察到冬末和早春温度升高,可能加速芽的破裂,形成层的激活及其潜在的协调。除非在树冠水平上存在补偿机制,否则冠内温度异质性可能会导致树形不对称。在温室中对年轻的核桃树进行了原始的增温实验。从2月到8月,加热部分和对照部分之间的白天平均温差为4°C。增温处理明显提前了萌芽日期,长达14天。变暖并没有改变二次增长的恢复,而是提高了增长率,导致更高的木质部细胞产量(两倍)和径向增量增加(与对照相比,增加80%)。分生序列的恢复是异步的,没有对温度的协调。在形成层分裂前两周,温暖的树枝上的芽开始膨胀,比控制分支早一周。在变暖的情况下,注意到芽生态结束时碳和水的再动员存在差异。总的来说,我们的结果证明在冠尺度上缺乏补偿机制,这可能会导致树冠内温度异质性的显着变化。
    Trees are exposed to significant spatio-temporal thermal variations, which can induce intracrown discrepancies in the onset and dynamics of primary and secondary growth. In recent decades, an increase in late winter and early spring temperatures has been observed, potentially accelerating bud break, cambial activation and their potential coordination. Intracrown temperature heterogeneities could lead to asymmetric tree shapes unless there is a compensatory mechanism at the crown level. An original warming experiment was conducted on young Juglans regia trees in a greenhouse. From February to August, the average temperature difference during the day between warmed and control parts was 4°C. The warming treatment advanced the date of budbreak significantly, by up to 14 days. Warming did not alter secondary growth resumption but increased growth rates, leading to higher xylem cell production (twice as many) and to an increase in radial increment (+80% compared to control). Meristems resumptions were asynchronous without coordination in response to temperature. Buds on warmed branches began to swell two weeks prior to cambial division, which was one week earlier than on control branches. A difference in carbon and water remobilisation at the end of bud ecodormancy was noted under warming. Overall, our results argue for a lack of compensatory mechanisms at the crown scale, which may lead to significant changes in tree architecture in response to intra-crown temperature heterogeneities.
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  • 文章类型: Journal Article
    土壤中微量元素(TEs)的来源多样性和健康风险使得揭示污染之间的关系成为必要,来源,和风险。然而,对空间异质性的忽视制约了现有识别方法的可靠性。在这项研究中,空间异质性被认为是准确剖析土壤TEs污染源风险联系的必要和可行因素。通过集成正矩阵分解,开发了一个全面的框架,地质探测器,和风险评估工具,并成功应用于中国北方一个矿业密集型城市。总的来说,TEs来自自然背景(28.5%),大气沉降(25.6%),煤炭开采(21.8%),和金属工业(24.1%)。高方差TEs(Se,Hg,Cd)首先通过揭示异质源-汇关系来系统地破译。具体来说,硒占主导地位(76.5%)为非均质煤炭开采(q=0.187),汞是由金属开采(q=0.183)和冶炼(q=0.363)的异质性确定的(92.6%),Cd是由地形和土壤特性共同影响的异质大气沉降(q>0.254)引起的(50.9%)。高度异质的来源也值得注意,因为它们有可能在当地造成极端风险(THI=1.122)。本研究强调了在土壤TEs污染和风险评估中整合空间异质性的必要性。
    The source diversity and health risk of trace elements (TEs) in soil make it necessary to reveal the relationship between pollution, source, and risk. However, neglect of spatial heterogeneity restricts the reliability of existing identification methods. In this study, spatial heterogeneity is proposed as a necessary and feasible factor for accurately dissecting the pollution-source-risk link of soil TEs. A comprehensive framework is developed by integrating positive matrix factorization, Geodetector, and risk evaluation tools, and successfully applied in a mining-intensive city in northern China. Overall, the TEs are derived from natural background (28.5 %), atmospheric deposition (25.6 %), coal mining (21.8 %), and metal industry (24.1 %). The formation mechanism of heterogeneity for high-variance TEs (Se, Hg, Cd) is first systematically deciphered by revealing the heterogeneous source-sink relationship. Specifically, Se is dominated (76.5 %) by heterogeneous coal mining (q=0.187), Hg is determined (92.6 %) by the heterogeneity of metal mining (q=0.183) and smelting (q=0.363), and Cd is caused (50.9 %) by heterogeneous atmospheric deposition (q>0.254) co-influenced by the terrains and soil properties. Highly heterogeneous sources are also noteworthy for their potential to pose extreme risks (THI=1.122) in local areas. This study highlights the necessity of integrating spatial heterogeneity in pollution and risk assessment of soil TEs.
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  • 文章类型: Journal Article
    细胞呼吸辅因子NADH(还原型烟酰胺腺嘌呤二核苷酸)和FAD++(氧化的黄素腺嘌呤二核苷酸)的荧光强度反映皮肤和其他组织中的能量代谢,并且可以通过荧光光谱法(FS)在体内定量。然而,生理参数的变异性在很大程度上决定了测量结果的可重复性和诊断测试的可靠性。在这项前瞻性研究中,我们评估了基线时通过FS评估的51名健康志愿者皮肤中NADH和FAD++荧光强度测量的日间重现性,在局部冷却(10°C)和加热皮肤(35°C)后。结果表明,前臂皮肤中NADH(AFNADH)的荧光幅度是研究的FS参数中最具可重复性的。结合热功能测试评估前臂背侧的AFNADH是临床上用于评估皮肤能量代谢的最有前途的方法。
    The fluorescence intensities of the cellular respiratory cofactors NADH (reduced nicotinamide adenine dinucleotide) and FAD++ (oxidized flavin adenine dinucleotide) reflect energy metabolism in skin and other tissues and can be quantified in vivo by fluorescence spectroscopy (FS). However, the variability of physiological parameters largely determines the reproducibility of measurement results and the reliability of the diagnostic test. In this prospective study, we evaluated the interday reproducibility of NADH and FAD++ fluorescence intensity measurements in the skin of 51 healthy volunteers assessed by the FS at baseline, after local cooling (10°C) and heating of the skin (35°C). Results showed that the fluorescence amplitude of NADH (AFNADH) in forearm skin was the most reproducible of the FS parameters studied. Assessment of AFNADH in the dorsal forearm in combination with a thermal functional test is the most promising method for clinical use for assessing energy metabolism in the skin.
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  • 文章类型: Journal Article
    健康的社会决定因素是人们出生的环境条件,活,学习,工作,玩,崇拜,影响广泛健康的年龄,功能和生活质量的结果和风险-这些健康的社会决定因素通常有助于解释美国(US)存在的种族和族裔健康不平等。这些社会健康决定因素的根本原因与结构性种族主义有关,居住隔离是结构性种族主义的一个领域,允许结构性种族主义的地理实施。这篇评论的重点是三种住宅隔离措施,这些措施通常用于将隔离作为种族/族裔的函数,收入,同时种族/民族和收入。提出了与这些住宅隔离措施的时空异质性有关的经验发现。我们还讨论了利用这三种住宅隔离措施的一些含义。
    Social determinants of health are the conditions in the environments where people are born, live, learn, work, play, worship, and age that affect a wide range of health, functioning and quality of life outcomes and risks - these social determinants of health often aid in explaining the racial and ethnic health inequities present in the United States (US). The root cause of these social determinants of health has been tied to structural racism, and residential segregation is one such domain of structural racism that allows for the operationalization of the geography of structural racism. This review focuses on three residential segregation measures that are often utilized to capture segregation as a function of race/ethnicity, income, and simultaneously race/ethnicity and income. Empirical findings related to the spatial and spatio-temporal heterogeneity of these residential segregation measures are presented. We also discuss some of the implications of utilizing these three residential segregation measures.
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  • 文章类型: Journal Article
    有大量的研究表明,暴力对弱势社区的健康产生不成比例的影响,了解最近的暴力犯罪趋势对于促进健康公平至关重要。劫车事件引起了媒体的特别关注,尽管对这种暴力犯罪的研究很少。我们使用中断的时间序列模型来研究警察杀害乔治·弗洛伊德对明尼阿波利斯劫车的时空模式与邻里劣势的影响。提供接地,我们将我们的结果与经过充分研究的凶杀模式进行比较。结果表明,在乔治·弗洛伊德被谋杀和随后的社会动荡之后,劫车事件在空间上都有所增加和分散。比杀人更重要。社会弱势社区的绝对增长最大,而优势社区的相对增长更大。未来的挑战是确定政策对策,以有效遏制这种暴力,而不诉诸严厉和不公平的警务和量刑做法。
    There is abundant research showing the disproportionate impacts of violence on health in disadvantaged neighborhoods, making an understanding of recent violent crime trends essential for promoting health equity. Carjackings have been of particular interest in the media, although little research has been undertaken on this violent crime. We use interrupted time series models to examine the impact of the police killing of George Floyd on the spatiotemporal patterns of carjacking in Minneapolis in relation to neighborhood disadvantage. To provide grounding, we compare our results to the well-studied patterns of homicides. Results indicate that carjackings both increased and dispersed spatially after the murder of George Floyd and subsequent social unrest, more so than homicides. Socially disadvantaged neighborhoods experienced the greatest absolute increase while more advantaged neighborhoods saw a greater relative increase. The challenge ahead is to identify policy responses that will effectively curb such violence without resorting to harsh and inequitable policing and sentencing practices.
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  • 文章类型: Journal Article
    了解丛枝菌根真菌(AMF)组合的驱动因素对于利用AMF对植物生长和健康的益处至关重要。丛枝菌根真菌即使在小范围内也在空间上异质分布。我们回顾了植物分布在驱动AMF组合中的作用(乘客假设),使用景观生态学概念框架的换位。因为生根系统对应于具有有限承载能力的栖息地斑块,由于寄主偏好效应而质量不同,我们建议将植物群落视为AMF微生境的马赛克。我们回顾了景观生态学的预测如何应用于植物群落对AMF的影响,以及检验这些预测的现有证据。尽管已经进行了许多关于植物组成异质性对AMF组合的影响的研究,他们主要关注植物丰富度的影响,虽然只有少数人研究了构型异质性的影响,植物连通性或植物群落时间动态。我们提出了关键预测和未来前景来填补这些空白。将植物群落视为景观,通过包括空间明确的维度及其相关的生态过程来扩展乘客假设,并可能有助于在小空间尺度上理解和操纵AMF组合。
    Understanding the drivers of assemblages of arbuscular mycorrhizal fungi (AMF) is essential to leverage the benefits of AMF for plant growth and health. Arbuscular mycorrhizal fungi are heterogeneously distributed in space even at small scale. We review the role of plant distribution in driving AMF assemblages (the passenger hypothesis), using a transposition of the conceptual framework of landscape ecology. Because rooting systems correspond to habitat patches with limited carrying capacity that differ in quality due to host-preference effects, we suggest considering plant communities as mosaics of AMF microhabitats. We review how predictions from landscape ecology apply to plant community effects on AMF, and the existing evidence that tests these predictions. Although many studies have been conducted on the effect of plant compositional heterogeneity on AMF assemblages, they mostly focused on the effect of plant richness, while only a few investigated the effect of configurational heterogeneity, plant connectivity or plant community temporal dynamics. We propose key predictions and future prospects to fill these gaps. Considering plant communities as landscapes extends the passenger hypothesis by including a spatially explicit dimension and its associated ecological processes and may help understand and manipulate AMF assemblages at small spatial scales.
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  • 文章类型: Journal Article
    背景:在发展中国家,与发达国家相比,儿童和母亲的死亡概率更大;这些健康结果的不平等是不公平的。本研究包括对巴基斯坦母婴死亡率的空间分析。该研究旨在估计地区死亡率指数(MDI),测量不等式比率和斜率,并确定众多因素对巴基斯坦各地区STI分数的空间影响。
    方法:本研究使用来自多指标聚类调查(MICS)的微观水平家庭数据集来估计MI。为了找出QI分数有多不同,使用不等式比率和斜率。这项研究进一步利用空间自相关测试来确定具有高死亡率和低死亡率的集群的空间依赖性的大小和位置。地理加权回归(GWR)模型也被用来检验社会经济的空间影响,环境,健康,和dmi上的住房属性。
    结果:MI的不平等比率表明,上十分位数地区的死亡率是下十分位数地区的16倍,Bal路支省的地区在MI方面描述了极端的空间异质性。地方空间关联指标(LISA)和Moran\的检验结果证实了巴基斯坦各地区所有死亡率的空间同质性。H-H孕产妇死亡率和MI集中在俾路支省,在旁遮普邦看到了儿童死亡率的H-H集群。GWR的结果表明,财富指数五分位数对STI有显著的空间影响;然而,改善卫生条件,洗手的做法,和产前护理对MI评分产生不利影响。
    结论:研究结果揭示了巴基斯坦地区所有死亡率之间的MI和空间关系的显着差异。此外,社会经济,环境,健康,住房变量对DMA有影响。值得注意的是,有死亡风险的个体之间的空间接近性发生在死亡率升高的地区.政策制定者可以通过关注脆弱地区和实施提高公众意识等措施来减轻这些死亡率,加强医疗服务,改善获得清洁饮用水和卫生设施的机会。
    BACKGROUND: In developing countries, the death probability of a child and mother is more significant than in developed countries; these inequalities in health outcomes are unfair. The present study encompasses a spatial analysis of maternal and child mortalities in Pakistan. The study aims to estimate the District Mortality Index (DMI), measure the inequality ratio and slope, and ascertain the spatial impact of numerous factors on DMI scores across Pakistani districts.
    METHODS: This study used micro-level household datasets from multiple indicator cluster surveys (MICS) to estimate the DMI. To find out how different the DMI scores were, the inequality ratio and slope were used. This study further utilized spatial autocorrelation tests to determine the magnitude and location of the spatial dependence of the clusters with high and low mortality rates. The Geographically Weighted Regression (GWR) model was also applied to examine the spatial impact of socioeconomic, environmental, health, and housing attributes on DMI.
    RESULTS: The inequality ratio for DMI showed that the upper decile districts are 16 times more prone to mortalities than districts in the lower decile, and the districts of Baluchistan depicted extreme spatial heterogeneity in terms of DMI. The findings of the Local Indicator of Spatial Association (LISA) and Moran\'s test confirmed spatial homogeneity in all mortalities among the districts in Pakistan. The H-H clusters of maternal mortality and DMI were in Baluchistan, and the H-H clusters of child mortality were seen in Punjab. The results of GWR showed that the wealth index quintile has a significant spatial impact on DMI; however, improved sanitation, handwashing practices, and antenatal care adversely influenced DMI scores.
    CONCLUSIONS: The findings reveal a significant disparity in DMI and spatial relationships among all mortalities in Pakistan\'s districts. Additionally, socioeconomic, environmental, health, and housing variables have an impact on DMI. Notably, spatial proximity among individuals who are at risk of death occurs in areas with elevated mortality rates. Policymakers may mitigate these mortalities by focusing on vulnerable zones and implementing measures such as raising public awareness, enhancing healthcare services, and improving access to clean drinking water and sanitation facilities.
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  • 文章类型: Journal Article
    高纬度极地和青藏高原的全氟烷基和多氟烷基物质(PFASs)受到了国际上的广泛关注。这里,我们测量了湖水中的18种PFAS和11种主要异构体,沉积物,以及2020年NamCo湖周围的径流。首次报道了高纬度极地地区和青藏高原水体中超短链三氟乙酸(TFA)和全氟丙酸(PFPrA)以及全氟辛酸(PFOA)和全氟辛烷磺酸(PFOS)的主要异构体的浓度。结果表明,冰川径流中的∑PFASs浓度比非冰川径流中的∑PFASs浓度高约139%。多次冰川径流事件的南湖湖水和沉积物中∑PFASs的浓度分别高出约113%和108%,分别,比那些在北湖。短链全氟丁酸(PFBA)和超短链TFA和PFPrA的浓度,这可能是冰雪融化的指标,表现出显著的空间异质性。总的来说,水中PFAS浓度的空间异质性,NamCo湖的沉积物和周围径流可能主要是由冰川融化引起的。
    Per- and polyfluoroalkyl substances (PFASs) in high-latitude polar regions and the Tibetan Plateau have received widespread international attention. Here, we measured 18 PFASs and 11 major isomers in the lake water, sediment, and surrounding runoff of Lake Nam Co in 2020. The concentrations of ultrashort-chain trifluoroacetic acid (TFA) and perfluoropropanoic acid (PFPrA) and major isomers of perfluoooctanoic acid (PFOA) and perfluoooctane sulfonate acid (PFOS) in water bodies in high-latitude polar regions and the Tibetan Plateau are reported for the first time. The results showed that the concentration of ∑PFASs in glacial runoff was approximately 139 % greater than that in nonglacial runoff. The concentrations of ∑PFASs in the lake water and sediment in the southern lake with multiple glacial runoff events were approximately 113 % and 108 % higher, respectively, than those in the northern lake. The concentrations of short-chain perfluorobutanoic acid (PFBA) and ultrashort-chain TFA and PFPrA, which may be indicators of ice and snow melt, exhibited significant spatial heterogeneity. Overall, the spatial heterogeneity of PFAS concentrations in the water, sediment and surrounding runoff of Lake Nam Co may be caused mainly by glacial melting.
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  • 文章类型: Journal Article
    通过土地利用变化评估大规模人类活动对碳储存的影响越来越受到陆地生态系统评估的关注。淮河流域,一个重要的中国粮食生产区,随着社会经济的加速,土地利用发生了显著的变化。评估土地利用变化对碳储量和未来碳固存的影响对于区域生态系统可持续性和中国粮食安全至关重要。同时,为区域土地利用规划和决策过程提供数据支持。尽管如此,将土地利用变化与碳储量和未来碳库响应联系起来的机制仍不清楚。我们利用了多源数据集和代表性场景,集成PLUS,InVEST模型,和地质探测器评估土地利用变化对淮河流域碳储量的影响(2000-2030)。数据表明:(1)从2000年到2020年,耕地减少了28,344.69km2,建设用地增加了26,914.56km2,其他土地类型变化不大。(2)土地利用变化导致碳损失1.17×108t,主要是由于建设用地的扩大。(3)四种模拟情景均表现出碳储量相对于2020年有所减少,经济发展情景最低为4.98×109t,生态保护情景最高为5.06×109t。(4)海拔主要驱动碳储量变化,它与核电站的相互作用影响最大。这些因素协同增强了它们的解释力。该研究为旨在增强区域碳固存和完善低碳土地管理的策略提供了科学依据,维护生态系统稳定。
    Evaluating the impact of large-scale human activities on carbon storage through land use changes is of growing interest in terrestrial ecosystem assessments. The Huaihe River Basin, a vital Chinese grain production area, has undergone marked land use changes amid socio-economic acceleration. Evaluating the impacts of land use change on carbon storage and future carbon sequestration is imperative for regional ecosystem sustainability and Chinese food security, simultaneously, furnishing data support to regional land use planning and decision-making processes. Nonetheless, the mechanisms linking land use changes to carbon storage and the future carbon reservoir responses remain unclear. We utilized a multi-source dataset and representative scenarios, integrating PLUS, InVEST models, and Geodetector to assess land use change impacts on carbon storage in the Huaihe River Basin (2000-2030). The data indicates the following: (1) from 2000 to 2020, cultivated land decreased by 28,344.69 km2, construction land increased by 26,914.56 km2, and other land types changed little. (2) Land use change resulted a carbon loss of 1.17 × 108 t, primarily due to the expansion of construction land. (3) All four simulation scenarios exhibited diminished carbon storage relative to 2020, with the economic development scenario recording the lowest at 4.98 × 109 t and the ecological protection scenario the highest at 5.06 × 109 t. (4) Elevation predominantly drives carbon storage changes, with its interaction with NPP having the greatest impact. The factors synergistically enhance their explanatory power. The research provides a scientific basis for strategies aimed at augmenting regional carbon sequestration and refining low-carbon land management, safeguarding ecosystem stability.
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