Generalized additive model

广义加性模型
  • 文章类型: Journal Article
    物种-环境关系已通过物种分布模型(SDM)和物种丰度模型(SAM)进行了广泛的探索。它们已成为了解生物多样性保护的空间生态学和种群动态的关键组成部分。尽管如此,在物种范围的内部结构内,栖息地适宜性和物种丰富度并不总是表现出相似的模式,使用来自SDM或SAM的信息可能是不完整的,并误导了保护工作。我们评估了对丰度-适宜性关系的支持,并使用合并后的信息优先考虑了南美矮凯门虫(Paleosuchuspalpebrosus和P.trigonatus)的保护。我们使用了7个环境预测集(地表水,人类影响,地形,降水,温度,动态生境指数,土壤温度),2种回归方法(广义线性模型-GLM,广义加性模型-GAM),和4个参数分布(二项式,Poisson,负二项式,Gamma)来开发分布和丰度模型。我们使用最好的预测模型来定义四个类别(低,中等,高,非常高)计划物种保护。两种古生物物种的最佳分布和丰度模型包括所有预测集的组合,除了三角菌的最佳丰度模型只包含温度,降水,地表水,人类影响,和地形。我们发现环境适宜性预测丰度的非一致性和低解释力与先前有关SDM-SAM的研究一致。我们从每个最佳SDM和SAM中提取了最相关的信息,并创建了一个共识模型(2,790,583km2),我们将其归类为低(39.6%)。中等(42.7%),高(14.9%),和非常高(2.8%)的保护优先事项。我们确定了279,338平方公里,必须将保护列为优先事项,其中只有29%的区域受到保护。我们得出的结论是,来自相关方法的最佳模型可用于提供系统的优先排序方案,以促进保护,并作为替代品,以产生用于量化生态模式的见解。
    Species-environment relationships have been extensively explored through species distribution models (SDM) and species abundance models (SAM), which have become key components to understand the spatial ecology and population dynamics directed at biodiversity conservation. Nonetheless, within the internal structure of species\' ranges, habitat suitability and species abundance do not always show similar patterns, and using information derived from either SDM or SAM could be incomplete and mislead conservation efforts. We gauged support for the abundance-suitability relationship and used the combined information to prioritize the conservation of South American dwarf caimans (Paleosuchus palpebrosus and P. trigonatus). We used 7 environmental predictor sets (surface water, human impact, topography, precipitation, temperature, dynamic habitat indices, soil temperature), 2 regressions methods (Generalized Linear Models-GLM, Generalized Additive Models-GAM), and 4 parametric distributions (Binomial, Poisson, Negative binomial, Gamma) to develop distribution and abundance models. We used the best predictive models to define four categories (low, medium, high, very high) to plan species conservation. The best distribution and abundance models for both Paleosuchus species included a combination of all predictor sets, except for the best abundance model for P. trigonatus which incorporated only temperature, precipitation, surface water, human impact, and topography. We found non-consistent and low explanatory power of environmental suitability to predict abundance which aligns with previous studies relating SDM-SAM. We extracted the most relevant information from each optimal SDM and SAM and created a consensus model (2,790,583 km2) that we categorized as low (39.6%), medium (42.7%), high (14.9%), and very high (2.8%) conservation priorities. We identified 279,338 km2 where conservation must be critically prioritized and only 29% of these areas are under protection. We concluded that optimal models from correlative methods can be used to provide a systematic prioritization scheme to promote conservation and as surrogates to generate insights for quantifying ecological patterns.
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  • 文章类型: Journal Article
    藻类对环境因素高度敏感,特别是营养波动;过多的营养会导致特定藻类的增殖,导致优势。在这项研究中,我们旨在从资源利用效率(RUE)的角度重新评估藻类优势的变化。我们在不同的水系统建立了80个监测点,收集水和浮游植物样本。使用规范对应分析(CCA)和广义加性模型(GAM),我们分析了浮游植物RUE与养分浓度之间的相关性,量化藻类优势度与RUE的对应关系。我们的结果表明,总磷(TP)和总氮(TN)浓度的RUE之间存在显着负相关,但与N:P呈正相关TN的RUE与TN浓度和N:P呈负相关。我们用相互作用项构建了GAMs,并证实了藻类优势与RUE之间的非线性关系。当TN的RUE较低时,观察到正相关,而其他方面则呈负相关。这些发现揭示了藻类群落的生态适应性,并为预测藻类水华爆发的风险提供了有价值的见解。
    Algae are highly sensitive to environmental factors, especially nutrient fluctuations; excessive nutrients can lead to the proliferation of specific algae species, resulting in dominance. In this study, we aimed to reevaluate changes in algal dominance from the perspective of resource utilization efficiency (RUE). We established 80 monitoring sites across different water systems, collecting water and phytoplankton samples. Using canonical correspondence analysis (CCA) and a generalized additive model (GAM), we analyzed the correlation between phytoplankton RUE and nutrient concentrations, quantifying the corresponding relationship between algal dominance and RUE. Our results indicate a significant negative correlation between the RUE of total phosphorus (TP) and total nitrogen (TN) concentration, but a positive correlation with N:P. The RUE of TN was negatively correlated with TN concentration and N:P. We constructed GAMs with interaction terms and confirmed a nonlinear relationship between algal dominance and RUE. When the RUE of TN was low, a positive correlation was observed, while a negative correlation was observed otherwise. These findings reveal the ecological adaptability of algal communities and provide valuable insights for predicting the risk of algal bloom outbreaks.
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  • 文章类型: Journal Article
    了解和量化空气污染排放对水质变化的影响和贡献对于地表水质量保护和管理至关重要。为了解决这个问题,我们创建了一个包含六个水质指标-高锰酸盐指数(CODMn)的五年每日数据矩阵,NH3-N,pH值,浊度,电导率,和溶解有机物(DOM)-和六个空气污染指标-O3,CO,NO2、SO2、2.5μm颗粒物(PM2.5)、和可吸入颗粒物(PM10)-使用来自世界上最长的引水工程的七个国家监测站的数据,中国南水北调中线工程(MR-SNWD)。多变量技术(Mann-Kendall,斯皮尔曼的相关性,滞后相关性,和广义加性模型[GAMs])用于检查空气污染对水质的非线性关系和滞后效应。空气污染和水质沿MR-SNWD表现出明显的空间异质性,所有水质参数均符合I类或II类国家标准,并且空气污染指标超过这些阈值。除了CODMn和DOM,其他水质和空气污染指标表现出显著的季节性差异。空气污染对北站水质表现出明显的滞后效应,NO2、SO2、PM2.5和PM10与pH值的变化高度相关,平均滞后17天。基于GAMs,滞后效应增强了空气污染与水质之间的显著非线性关系,增加为CODMn解释的平均偏差,NH3-N,和93%的pH值,24%,41%,分别。这些发现为保护人为空气污染下长距离跨流域引水工程的水质提供了科学依据。
    Understanding and quantifying the influences and contributions of air pollution emissions on water quality variations is critically important for surface water quality protection and management. To address this, we created a five-year daily data matrix of six water quality indicators-permanganate index (CODMn), NH3-N, pH, turbidity, conductivity, and dissolved organic matter (DOM)-and six air pollution indicators-O3, CO, NO2, SO2, 2.5 μm particulate matter (PM2.5), and inhalable particles (PM10)-using data from seven national monitoring stations along the world\'s longest water-diversion project, the Middle Route of the South-to-North Water Diversion Project in China (MR-SNWD). Multivariate techniques (Mann-Kendall, Spearman\'s correlation, lag correlation, and Generalized Additive Models [GAMs]) were applied to examine the nonlinear relationships and lag effects of air pollution on water quality. Air pollution and water quality exhibited marked spatial heterogeneity along the MR-SNWD, with all water quality parameters meeting Class I or II national standards and the air pollution indicators exceeding those thresholds. Except for CODMn and DOM, the other water quality and air pollution indicators exhibited significant seasonal differences. Air pollution exhibited significant lag effects on water quality at the northern stations, with NO2, SO2, PM2.5, and PM10 being highly correlated with changes in pH, with an average lag of 17 d. Based on the GAMs, lag effects enhanced the significant nonlinear relationships between air pollution and water quality, increasing the average deviance explained for CODMn, NH3-N, and pH by 93%, 24%, and 41%, respectively. These findings provide a scientific basis for protecting water quality along the long-distance inter-basin water-diversion project under anthropogenic air pollution.
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  • 文章类型: Journal Article
    背景:废水监测数据可用于估计疾病趋势,以告知公共卫生应对措施。一个通常估计的指标是病原体数量的变化率,这通常与回顾性分析中的临床监测相关。然而,变化率估计方法的准确性以前没有被评估过。
    目的:我们通过生成已知变化率的合成废水时间序列数据,评估了估算废水病原体负荷变化率的方法的性能。每种方法也在现实世界的数据上进行了评估。
    方法:从高斯过程(GP)联合采样平滑趋势及其一阶导数,并添加独立误差以生成合成病毒载量测量;范围超参数和误差方差变化以产生代表不同潜在疾病模式的9种模拟场景。将来自四种估计方法(这项工作中建立的两种和开发的两种)的变化率估计的方向和大小与GP一阶导数进行了比较,以评估分类和定量准确性。每种方法还适用于2021年1月至2023年5月在北卡罗来纳州25个地点收集的公共SARS-CoV-2废水监测数据。美国。
    结果:所有四种方法都不一致地确定了GP一阶导数符号给出的趋势的正确方向。在所有九种模拟疾病模式中,在所有估计的四分之一到一半之间表明了错误的趋势方向,不管估计方法如何。北卡罗莱纳州SARS-CoV-2数据被分类为高原(在统计上与零没有区别)的趋势的比例通过估计方法而不是站点差异很大。
    结论:我们的结果表明,仅靠废水测量可能无法提供足够的数据来实时可靠地跟踪疾病趋势。相反,废水病毒载量可以与其他公共卫生监测数据相结合,以改善对其他结果的预测。
    BACKGROUND: Wastewater monitoring data can be used to estimate disease trends to inform public health responses. One commonly estimated metric is the rate of change in pathogen quantity, which typically correlates with clinical surveillance in retrospective analyses. However, the accuracy of rate of change estimation approaches has not previously been evaluated.
    OBJECTIVE: We assessed the performance of approaches for estimating rates of change in wastewater pathogen loads by generating synthetic wastewater time series data for which rates of change were known. Each approach was also evaluated on real-world data.
    METHODS: Smooth trends and their first derivatives were jointly sampled from Gaussian processes (GP) and independent errors were added to generate synthetic viral load measurements; the range hyperparameter and error variance were varied to produce nine simulation scenarios representing different potential disease patterns. The directions and magnitudes of the rate of change estimates from four estimation approaches (two established and two developed in this work) were compared to the GP first derivative to evaluate classification and quantitative accuracy. Each approach was also implemented for public SARS-CoV-2 wastewater monitoring data collected January 2021-May 2023 at 25 sites in North Carolina, USA.
    RESULTS: All four approaches inconsistently identified the correct direction of the trend given by the sign of the GP first derivative. Across all nine simulated disease patterns, between a quarter and a half of all estimates indicated the wrong trend direction, regardless of estimation approach. The proportion of trends classified as plateaus (statistically indistinguishable from zero) for the North Carolina SARS-CoV-2 data varied considerably by estimation method but not by site.
    CONCLUSIONS: Our results suggest that wastewater measurements alone might not provide sufficient data to reliably track disease trends in real-time. Instead, wastewater viral loads could be combined with additional public health surveillance data to improve predictions of other outcomes.
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  • 文章类型: Journal Article
    我们检查了美国600个空气监测站的PM2.5和危险测绘系统烟雾羽流卫星数据,以识别2018-2023年所有5月至9月的14.0%的表面烟雾,由于加州火灾,2020年和2021年的影响很大,和2023年,由于加拿大火灾。与不吸烟日相比,吸烟日的PM2.5平均多11μgm-3,最大每日8小时平均(MDA8)O3浓度高8ppb,它们还占超过每日PM2.5卫生标准(35μgm-3)的所有天数的94%和超过O3卫生标准(70ppb)的所有天数的36%。为了估计烟雾对O3MDA8的贡献,使用非烟雾日数据和多达8个预测因子为每个站点建立了广义加和模型(GAM)。非吸烟日数据的GAM残差的平均值和标准偏差为0±6.1ppb,吸烟日数据为4.3±7.9ppb,表明MDA8O3在烟雾日显着增强。我们在72%的吸烟日发现了阳性残差,这些天,我们计算出烟雾对O3MDA8的平均贡献为7.8±6.0ppb。在6年的时间里,美国大陆烟雾导致的超标天数占所有超标天数的25%,最高的是2023年(38%)。2023年,美国中部经历了异常多的超限天数,1522年,其中52%受到烟雾的影响,虽然美国东部的超常天数较少,288,其中78%受到烟雾的影响。我们的结果表明,野地大火是PM2.5和O3基于健康的国家空气质量标准超标的原因。
    We examined PM2.5 and Hazard Mapping System smoke plume satellite data at ∼600 United States (US) air monitoring stations to identify surface smoke on 14.0% of all May-September days for 2018-2023, with large influences in 2020 and 2021, due to California fires, and 2023, due to Canadian fires. Days with smoke have an average of 11 μg m-3 more PM2.5 and 8 ppb higher maximum daily 8 h average (MDA8) O3 concentrations than nonsmoke days, and they also account for 94% of all days that exceed the daily PM2.5 health standard (35 μg m-3) and 36% of all days that exceed the O3 health standard (70 ppb). To estimate the smoke contributions to the O3 MDA8, Generalized Additive Models (GAMs) were built for each site using the nonsmoke day data and up to 8 predictors. The mean and standard deviation of the residuals from the GAMs were 0 ± 6.1 ppb for the nonsmoke day data and 4.3 ± 7.9 ppb for the smoke day data, indicating a significant enhancement in the MDA8 O3 on smoke days. We found positive residuals on 72% of the smoke days and for these days, we calculate an average smoke contribution to the O3 MDA8 of 7.8 ± 6.0 ppb. Over the 6 year period, the percentage of exceedance days due to smoke in the continental US was 25% of all exceedance days, and the highest was in 2023 (38%). In 2023, the Central US experienced an unusually high number of exceedance days, 1522, with 52% of these impacted by smoke, while the Eastern US had fewer exceedance days, 288, with 78% of these impacted by smoke. Our results demonstrate the importance of wildland fires as contributors to exceedances of the health-based national air quality standards for PM2.5 and O3.
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  • 文章类型: Journal Article
    由于类固醇对诊断内分泌失调至关重要,缺乏对影响激素水平的因素的研究使得解释结果变得困难。我们的研究旨在评估分析前程序的稳定性以及使用现实世界数据的荷尔蒙生理波动的影响。该数据集是使用来自个体的12,418条记录创建的,这些个体的类固醇激素测量是在2019年9月至2024年3月期间在我们的实验室进行的。我们使用经过充分验证的液相色谱和串联质谱技术常规测量了血浆中的22种类固醇激素。归一化转换后,离群值去除,和z分数归一化,构建了广义相加模型来评估预分析稳定性和年龄,性别,和样本时间依赖的荷尔蒙波动。大多数激素随着年龄的增长表现出显著的变异性,特别是类固醇激素前体,性激素,和某些皮质类固醇如醛固酮。18-羟基皮质醇,18-氧皮质醇,性激素在男性和女性之间有所不同。某些激素水平,包括皮质醇,可的松,11-脱氧皮质醇,18-羟基皮质醇,18-氧皮质醇,皮质酮,醛固酮,estrone,睾丸激素,双氢睾酮,硫酸脱氢表雄酮,11-酮雌酮,和11-羟基睾酮,随采样时间波动。此外,孕烯醇酮和孕酮水平在取样后1小时内下降,孕烯醇酮在离心后4度的储存时间变得不稳定,而其他激素水平在不离心或离心样品后的短时间内保持相对稳定。这是首次使用真实世界数据来评估血浆激素的分析前稳定性并评估生理因素对类固醇激素的影响。
    Since steroids are crucial for diagnosing endocrine disorders, the lack of research on factors that affect hormone levels makes interpreting the results difficult. Our study aims to assess the stability of the pre-analytical procedure and the impact of hormonal physiological fluctuations using real-world data. The datasets were created using 12,418 records from individuals whose steroid hormone measurements were taken in our laboratory between September 2019 and March 2024. 22 steroid hormones in plasma by a well-validated liquid chromatography tandem mass spectrometry method were measured. After normalization transformation, outlier removal, and z-score normalization, generalized additive models were constructed to evaluate preanalytic stability and age, sex, and sample time-dependent hormonal fluctuations. Most hormones exhibit significant variability with age, particularly steroid hormone precursors, sex hormones, and certain corticosteroids such as aldosterone. 18-hydroxycortisol, 18-oxocortisol. Sex hormones varied between males and females. Levels of certain hormones, including cortisol, cortisone, 11-deoxycortisol, 18-hydroxycortisol, 18-oxocortisol, corticosterone, aldosterone, estrone, testosterone, dihydrotestosterone, dehydroepiandrosterone sulfate, 11-ketotestosterone, and 11-hydroxytestosterone, fluctuated with sampling time. Moreover, levels of pregnenolone and progesterone decreased within 1 hour of sampling, with pregnenolone becoming unstable with storage time at 4 degrees after centrifugation, while other hormone levels remained relatively stable for a short period of time without or after centrifugation of the sample. This is the first instance real-world data has been used to assess the pre-analytic stability of plasma hormones and to evaluate the impact of physiological factors on steroid hormones.
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  • 文章类型: Journal Article
    背景:仅在少数研究中检查了化学暴露与估计的肾小球滤过率(eGFR)之间的不一致关系。我们调查了一项代表性研究中招募的361名个体中对羟基苯甲酸酯暴露与肾功能指标之间的关联。
    方法:尿对羟基苯甲酸酯的水平,包括对羟基苯甲酸甲酯(MeP),对羟基苯甲酸乙酯(EtP),对羟基苯甲酸丙酯(PrP),和对羟基苯甲酸丁酯(BuP),使用UPLC-MS/MS进行测量。使用多元逻辑回归和贝叶斯内核机回归(BKMR)评估对羟基苯甲酸酯暴露与肾功能指标之间的关联。
    结果:成人组的尿对羟基苯甲酸酯的中位数水平明显高于次要组,也就是说,397vs.148ng/mL的MeP,38.8vs.EtP为13.6ng/mL,117vs.PrP为57.7ng/mL,和6.61vs.对于BuP为2.79ng/mL(所有P<0.001)。在成人组中,多变量回归模型证实白蛋白-肌酐比值与尿MeP(β=0.580)和BUN(β=0.061)呈正相关,eGFR(β=-0.051)与尿EtP呈负相关(均P<0.001)。在成人组中,与最低三元组相比,尿EtP水平的第三三分位数(T3)的调整比值比表明eGFR异常的风险增加了3.08倍,其次是第二个三分位数(T2),风险增加2.63倍。广义加性模型(GAM)和BKMR模型显示尿EtP水平与早期CKD呈非线性相关,以及降低eGFR。我们观察到尿对羟基苯甲酸酯对eGFR的显著正累积效应,和尿EtP与eGFR异常的显着正单一暴露效果。
    结论:我们发现暴露于EtP与高BUN水平和eGFR降低的风险之间存在显著关联。
    BACKGROUND: The inconsistent relationship between chemical exposure and estimated glomerular filtration rate (eGFR) has been examined in only a few studies. We investigated the association between paraben exposure and indicators of renal function in a total of 361 individuals recruiting from a representative study.
    METHODS: The levels of urinary parabens, including methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and butylparaben (BuP), were measured using UPLC-MS/MS. The association between paraben exposure and indices of renal function was assessed using multiple logistic regression and Bayesian Kernel Machine Regression (BKMR).
    RESULTS: The median levels of urinary parabens in the adult group were significantly higher than those in the minor group, that is, 397 vs. 148 ng/mL for MeP, 38.8 vs. 13.6 ng/mL for EtP, 117 vs. 57.7 ng/mL for PrP, and 6.61 vs. 2.79 ng/mL for BuP (all P < 0.001). In the adult group, multivariate regression models confirmed a positive association between the albumin-to-creatinine ratio and urinary MeP (β = 0.580) and a positive association of BUN (β = 0.061) and a negative association of eGFR (β = -0.051) with urinary EtP (all P < 0.001). In the adult group, compared with the lowest tertile group, the adjusted odds ratio in the third tertile (T3) of urinary EtP levels indicated a 3.08 times increased risk of eGFR abnormalities, followed by the second tertile (T2) with a 2.63 times increased risk. The generalized additive model (GAM) and BKMR models showed a non-linear correlation between urinary EtP levels and early CKD, as well as reduced eGFR. We observed a significant positive cumulative effect of urinary paraben on eGFR, and a significant positive single exposure effect of urinary EtP with eGFR abnormality.
    CONCLUSIONS: We found a significant association between exposure to EtP and an increased risk of high BUN levels and decreased eGFR.
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  • 文章类型: Journal Article
    目的:先前的研究表明,关于肥胖和骨质疏松之间的关系的观点相互矛盾。部分原因是肥胖分类的变化和这些关系的非线性性质。这项研究调查了肥胖指数与骨质疏松症之间的关系,使用双能X射线吸收法(DXA)诊断,采用非线性模型并提供最佳阈值以防止骨矿物质密度进一步下降。
    方法:2019年,一项前瞻性研究招募了50岁以上的男性和绝经后的女性。人体测量,血液生物化学,收集通过DXA测量的骨质疏松症。使用广义加性模型和分段回归模型分析肥胖指数与骨质疏松症之间的关联。
    结果:该研究包括872名女性和1321名男性。腹部容积指数(AVI)等指标,内脏肥胖指数(VAI),腰围(WC),臀围,体重指数(BMI),腰臀比,腰围与身高比(WHtR)与骨质疏松呈负相关.在女性中,骨质疏松症的风险与肥胖指数之间的关系呈U型,阈值为WC=94厘米,考虑到骨密度的变化,AVI=17.67cm2,BMI=25.74kg/m2,VAI=4.29,WHtR=0.61。相反,男性表现出逆关联的线性模式。
    结论:肥胖和肥胖对骨质疏松症的影响在男女之间有显著差异。在绝经后的女性中,关系是非线性的(U形),非常低和非常高的肥胖与更高的骨质疏松症风险相关。在50岁以上的男性中,这种关系是线性的,与较高的肥胖与较低的骨质疏松症风险相关。研究表明,保持特定的肥胖水平可以帮助预防绝经后妇女的骨质疏松症。
    OBJECTIVE: Previous research shows conflicting views on the relationship between obesity and osteoporosis, partly due to variations in obesity classification and the nonlinear nature of these relationships. This study investigated the association between adiposity indices and osteoporosis, diagnosed using dual-energy X-ray absorptiometry (DXA), employing nonlinear models and offering optimal thresholds to prevent further bone mineral density decline.
    METHODS: In 2019, a prospective study enrolled males over 50 years and postmenopausal women. Anthropometric measurements, blood biochemistry, and osteoporosis measured by DXA were collected. Associations between adiposity indices and osteoporosis were analyzed using a generalized additive model and segmented regression model.
    RESULTS: The study included 872 women and 1321 men. Indices such as abdominal volume index (AVI), visceral adiposity index (VAI), waist circumference (WC), hip circumference, body mass index (BMI), waist-to-hip ratio, and waist-to-height ratio (WHtR) were inversely associated with osteoporosis. In women, the relationship between the risk of osteoporosis and the adiposity indices was U-shaped, with thresholds of WC = 94 cm, AVI = 17.67 cm2, BMI = 25.74 kg/m2, VAI = 4.29, and WHtR = 0.61, considering changes in bone mineral density. Conversely, men exhibited a linear patterns for the inverse association.
    CONCLUSIONS: The impact of obesity and adiposity on osteoporosis varies significantly between women and men. In postmenopausal women, the relationship is nonlinear (U-shaped), with both very low and very high adiposity linked to higher osteoporosis risk. In men over 50, the relationship is linear, with higher adiposity associated with lower osteoporosis risk. The study suggests that maintaining specific levels of adiposity could help prevent osteoporosis in postmenopausal women.
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  • 文章类型: Journal Article
    在这种人口统计学中,探索膳食核黄素摄入与认知能力下降之间联系的研究是有限的。我们的目的是研究核黄素摄入水平与认知能力下降之间的关系。
    在此横截面分析中使用了2011年至2014年的国家健康和营养检查调查(NHANES)数据。建立阿尔茨海默病测试注册表的联盟Word学习延迟召回试验(DR),数字符号替换测试(DSST),动物流畅性测试(AFT)和Z测试用于评估认知表现。多元逻辑回归,我们进行了限制性三次样条和亚组分析,以评估核黄素摄入与认知功能下降之间的关联.
    该研究共包括2255名患者,其中47.9%是男性。认知功能下降的发生率为23.8%。调整所有选定的协变量后,我们发现,在美国成年人中,高核黄素摄入与较低的认知障碍风险相关.当核黄素摄入量被用作分类变量时,与摄入量最低的相比,DR试验中核黄素摄入量最高的个体的比值比(OR),后测试,DSST检验和Z检验为0.73(95%CI:0.53~1),0.68(95%CI:0.49-0.96),0.53(95%CI:0.37-0.77)和0.56(95%CI:0.39-0.8)。该研究还发现核黄素摄入与认知能力下降之间存在L形关联,拐点约为2.984mg/d。
    我们在美国老年人的全国样本中进行的横断面研究表明,饮食中的核黄素摄入与认知能力下降呈负相关。
    UNASSIGNED: Research exploring the link between dietary riboflavin intake and cognitive decline in this demographic is limited. Our aim was to examine the association between riboflavin intake levels and cognitive decline.
    UNASSIGNED: The National Health and Nutrition Examination Survey (NHANES) data from 2011 to 2014 were utilized in this cross-sectional analysis. The Consortium to Establish a Registry for Alzheimer\'s Disease test Word Learning delayed recall trial (DR), Digit Symbol Substitution Test (DSST), Animal Fluency Test(AFT) and Z test were used to evaluate cognitive performance. Multivariate logistic regression, restricted cubic spline and subgroup analysis were performed to evaluate the associations between riboflavin intake and cognitive decline.
    UNASSIGNED: The study included a total of 2255 patients, with 47.9% being male. The incidence of cognitive decline was 23.8%. After adjusting for all selected covariates, we found that high riboflavin intake was associated with a lower risk of cognitive impairment in adults in the United States. When riboflavin intake was used as a Categorical variable, compared to those with the lowest intake, the odds ratio (OR) of individuals with the highest riboflavin intake for DR test, AFT test, DSST test and Z test were 0.73 (95% CI: 0.53~1), 0.68(95% CI: 0.49-0.96),0.53(95% CI: 0.37-0.77) and 0.56(95% CI: 0.39-0.8). The study also found an L-shaped association between riboflavin intake and cognitive decline, with an inflection point at approximately 2.984 mg/d.
    UNASSIGNED: Our cross-sectional study in a nationwide sample of American old adults suggests that dietary riboflavin intake was negative associated with cognitive decline.
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  • 文章类型: Journal Article
    植物物候是反映气候变化对生态系统影响的重要指标。我们利用近地表遥感持续监测植被物候,即,2020年3月至2022年11月,中国黄土高原沟壑地区的PhenoCam。在每个图像中,选择了三个感兴趣的区域(ROI)来代表不同类型的植被(灌木丛,Arbor,和草原),并在每个ROI内计算了五个植被指数。结果表明,绿色色坐标(GCC),超额绿色指数(ExG),和植被对比指数(VCI)都很好地捕捉到了植被绿度的季节性变化。PhenoCam捕获了不同植被的季节性轨迹,反映了植被生长的差异。这种差异可能受到外部非生物环境因素的影响。我们用广义加性模型(GAM)分析了GCC系列对环境变量的非线性响应。我们的结果表明,土壤温度是影响黄土沟壑地区植物物候的重要驱动因素,特别是灌丛对土壤温度变化表现出显著的非线性响应。由于黄土高原小尺度的原位物候监测实验还比较少见,为进一步了解黄土高原植被物候变化和生态系统功能提供了参考。
    Plant phenology is an important indicator of the impact of climate change on ecosystems. We have continuously monitored vegetation phenology using near-surface remote sensing, i.e., the PhenoCam in a gully region of the Loess Plateau of China from March 2020 to November 2022. In each image, three regions of interest (ROIs) were selected to represent different types of vegetation (scrub, arbor, and grassland), and five vegetation indexes were calculated within each ROI. The results showed that the green chromatic coordinate (GCC), excess green index (ExG), and vegetation contrast index (VCI) all well-captured seasonal changes in vegetation greenness. The PhenoCam captured seasonal trajectories of different vegetation that reflect differences in vegetation growth. Such differences may be influenced by external abiotic environmental factors. We analyzed the nonlinear response of the GCC series to environmental variables with the generalized additive model (GAM). Our results suggested that soil temperature was an important driver affecting plant phenology in the Loess gully region, especially the scrub showed a significant nonlinear response to soil temperature change. Since in situ phenology monitoring experiments of the small-scale on the Loess Plateau are still relatively rare, our work provides a reference for further understanding of vegetation phenological variations and ecosystem functions on the Loess Plateau.
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