Mississippi

密西西比州
  • 文章类型: Journal Article
    了解臭氧引起的产量损失的长期变化趋势对于制定减轻臭氧破坏影响的策略至关重要。实现零饥饿可持续发展目标。尽管大量的实验研究表明,臭氧对农业生产的影响表现出明显的波动,并且在不同的地理位置之间存在显著差异。以前使用全球统计模型的研究往往无法捕捉到这种时空变化,导致臭氧影响估计的不确定性。为了解决这个问题,我们使用地理和时间加权回归(GTWR)模型,对美国(1981-2021年)臭氧对玉米和大豆产量影响的时空变化进行了综合评估.我们的结果显示,在过去的四十年里,臭氧污染导致玉米平均产量损失-3.5%,大豆平均产量损失-6.1%,每年的经济损失约为26亿美元。有趣的是,尽管在1997年实施严格的臭氧排放控制措施后,臭氧对作物产量的影响总体呈下降趋势,但我们的研究确定了干旱年份异常高的减产率的明显峰值。在整个研究区域的臭氧影响中检测到显著的空间异质性,玉米和大豆的臭氧损害热点位于东南地区和密西西比河流域,分别。此外,我们发现水热因素调节作物对臭氧的反应,随着温度的升高,玉米呈现出倒U型的产量损失趋势,大豆呈上升趋势。随着降水的增加,两种作物都经历了臭氧引起的产量损失。总的来说,我们的研究强调了将时空变异性纳入臭氧污染导致的作物产量损失评估的必要性。从我们的发现中获得的见解可以有助于制定特定地区的污染物排放政策,基于不同地区臭氧引起的农业损害的不同概况。
    Understanding the long-term change trends of ozone-induced yield losses is crucial for formulating strategies to alleviate ozone damaging effects, aiming towards achieving the Zero Hunger Sustainable Development Goal. Despite a wealth of experimental research indicating that ozone\'s influence on agricultural production exhibits marked fluctuations and differs significantly across various geographical locations, previous studies using global statistical models often failed to capture this spatial-temporal variability, leading to uncertainties in ozone impact estimation. To address this issue, we conducted a comprehensive assessment of the spatial-temporal variability of ozone impacts on maize and soybean yields in the United States (1981-2021) using a geographically and temporally weighted regression (GTWR) model. Our results revealed that over the past four decades, ozone pollution has led to average yield losses of -3.5% for maize and -6.1% for soybean, translating into an annual economic loss of approximately $2.6 billion. Interestingly, despite an overall downward trend in ozone impacts on crop yields following the implementation of stringent ozone emission control measures in 1997, our study identified distinct peaks of abnormally high yield reduction rates in drought years. Significant spatial heterogeneity was detected in ozone impacts across the study area, with ozone damage hotspots located in the Southeast Region and the Mississippi River Basin for maize and soybean, respectively. Furthermore, we discovered that hydrothermal factors modulate crop responses to ozone, with maize showing an inverted U-shaped yield loss trend with temperature increases, while soybean demonstrated an upward trend. Both crops experienced amplified ozone-induced yield losses with rising precipitation. Overall, our study highlights the necessity of incorporating spatiotemporal variability into assessments of crop yield losses attributable to ozone pollution. The insights garnered from our findings can contribute to the formulation of region-specific pollutant emission policies, based on the distinct profiles of ozone-induced agricultural damage across different regions.
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  • 文章类型: Letter
    暂无摘要。
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  • 文章类型: Journal Article
    背景心血管健康(CVH)状态的变化与心血管疾病的风险有关。然而,没有研究探讨CVH与心源性猝死(SCD)风险的变化规律.我们旨在研究基线CVH和CVH随时间变化与SCD风险之间的联系。方法和结果在前瞻性队列ARIC(社区动脉粥样硬化风险)研究中进行了分析,始于1987年至1989年。ARIC从美国4个社区招募了15792名45至64岁的人(福赛斯县,北卡罗来纳州;杰克逊,密西西比州;明尼阿波利斯的郊区,明尼苏达州;和华盛顿县,马里兰)。具有0至2、3至4和5至7个理想CVH指标的受试者被归类为不良,中间,或理想的CVH,分别。考虑了在1987年至1989年和1993年至1995年之间的6年内CVH的变化。主要研究结果是医生裁定的SCD。研究人群由15026名受试者组成,其中12207人有CVH变化的数据。在平均23.0年的随访中,记录583例SCD。基线CVH指标和随时间变化的CVH指标与SCD风险之间存在很强的负相关。与CVH持续较差的受试者相比,从不良到中等/理想的人群的SCD风险较低(风险比[HR],0.67[95%CI,0.48-0.94]),中级到穷人(HR,0.73[95%CI,0.54-0.99]),从中级到理想(HR,0.49[95%CI,0.24-0.99]),理想到差/中等CVH(HR,0.23[95%CI,0.10-0.52]),或那些具有一致中级(HR,0.49[95%CI,0.36-0.66])或一致理想的CVH(HR,0.31[95%CI,0.13-0.76])。对于非SCD也观察到类似的结果。结论与持续较差的CVH相比,CVH的其他变化模式与SCD风险较低相关.这些发现强调了在SCD的原始预防中促进理想CVH的重要性。
    Background The change of cardiovascular health (CVH) status has been associated with risk of cardiovascular disease. However, no studies have explored the change patterns of CVH in relation to risk of sudden cardiac death (SCD). We aim to examine the link between baseline CVH and change of CVH over time with the risk of SCD. Methods and Results Analyses were conducted in the prospective cohort ARIC (Atherosclerosis Risk in Communities) study, started in 1987 to 1989. ARIC enrolled 15 792 individuals 45 to 64 years of age from 4 US communities (Forsyth County, North Carolina; Jackson, Mississippi; suburbs of Minneapolis, Minnesota; and Washington County, Maryland). Subjects with 0 to 2, 3 to 4, and 5 to 7 ideal metrics of CVH were categorized as having poor, intermediate, or ideal CVH, respectively. Change in CVH over 6 years between 1987 to 1989 and 1993 to 1995 was considered. The primary study outcome was physician adjudicated SCD. The study population consisted of 15 026 subjects, of whom 12 207 had data about CVH change. Over a median follow-up of 23.0 years, 583 cases of SCD were recorded. There was a strong inverse association between baseline CVH metrics and time varying CVH metrics with risk of SCD. Compared with subjects with consistently poor CVH, risk of SCD was lower in those changed from poor to intermediate/ideal (hazard ratio [HR], 0.67 [95% CI, 0.48-0.94]), intermediate to poor (HR, 0.73 [95% CI, 0.54-0.99]), intermediate to ideal (HR, 0.49 [95% CI, 0.24-0.99]), ideal to poor/intermediate CVH (HR, 0.23 [95% CI, 0.10-0.52]), or those with consistently intermediate (HR, 0.49 [95% CI, 0.36-0.66]) or consistently ideal CVH (HR, 0.31 [95% CI, 0.13-0.76]). Similar results were also observed for non-SCD. Conclusions Compared with consistently poor CVH, other patterns of change in CVH were associated with lower risk of SCD. These findings highlight the importance of promotion of ideal CVH in the primordial prevention of SCD.
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  • 文章类型: Journal Article
    蓝色Lentic带是自1990年代以来在莫比尔河流域形成的密集的真实栖息地的空间带,它对当地和下游水生栖息地施加了相当大的环境压力。描述蓝色长乐带的时空演变对于了解其形成及其对当地环境的影响至关重要。然而,关于它的相关讨论是不存在的,因为蓝色的Lentic带是一个新的发现。在这项研究中,我们开发了一种回顾性的划定方法,以可视化莫比尔河流域的真实栖息地的时空演变,并开发了一个镶嵌模型,以数值方式分析了蓝色列蒂奇带的时空扩展。在开发的方法中,首先根据2019年Sentinel-2卫星图像以10m的空间分辨率划定真实栖息地的基准清单。然后,使用国家土地覆盖数据库(NLCD),将基准清单用于回顾性地描绘莫比尔河流域过去的真实栖息地。估计真实栖息地图像对象的核密度表面以检测密集的真实栖息地区域,依次形成密集的真实栖息地的时空物体。密集的真实栖息地的时空对象被投影到平面空间上,然后被结构化为空间镶嵌物,即α峰,β斜率,和γ边缘。对这些镶嵌物的属性进行了数值推导,以量化蓝色Lentic带的时空扩展。结果表明,蓝色Lentic带具有4个α峰,3个β斜坡,和单个γ边缘。它是由最密集的植物栖息地的4个稳定热点(α峰)形成的。蓝色Lentic带的扩展范围约为15.42公里。扩展距离约为蓝色Lentic带中β斜率平均范围的0.57,表明莫比尔河流域的景观发生了重大变化。农场养殖cat鱼产业的发展被认为是形成蓝色Lentic带的主要动力。这项研究的结果强调了蓝色Lentic带的迅速扩张及其对当地和下游水生栖息地的负面影响,这需要关注多个学科的系统性调查。
    The Blue Lentic Belt is a spatial belt of dense lentic habitats formed in the Mobile River Basin since the 1990s, and it is imposing considerable environmental stress on local and downstream aquatic habitats. Depicting the spatiotemporal evolution of the Blue Lentic Belt is essential to understanding its formation and consequential impacts on local environments. However, relevant discussion on it is absent since the Blue Lentic Belt is a new discovery. In this study, we developed a retrospective delineation method to visualize the spatiotemporal evolution of the lentic habitats in the Mobile River Basin and a tesseral model to numerically analyze the spatiotemporal expansion of the Blue Lentic Belt. In the developed method, the baseline inventory of lentic habitats is first delineated from 2019 Sentinel-2 satellite imagery at a spatial resolution of 10 m. The baseline inventory is then used to retrospectively delineate the past lentic habitats in the Mobile River Basin using the National Land Cover Database (NLCD). Kernel density surfaces of lentic habitat image objects are estimated to detect the regions of dense lentic habitats, which sequentially form spatiotemporal objects of dense lentic habitats. The spatiotemporal objects of dense lentic habitats are projected onto planar space and are then structuralized as groups of spatial tesserae, namely α-peaks, β-slopes, and γ-edges. Attributes of these tesserae are numerically derived to quantify the spatiotemporal expansion of the Blue Lentic Belt. The results indicate that the Blue Lentic Belt has 4 α-peaks, 3 β-slopes, and a single γ-edge. It is formed from 4 stable hotspots (α-peaks) of the densest lentic habitats. The expansion of the Blue Lentic Belt ranges about 15.42 km. The expansion distance is about 0.57 of the average range of the β-slopes in the Blue Lentic Belt, indicating a significant change of landscape in the Mobile River Basin. The development of the farm-raised catfish industry is considered the main driving force in the formation of the Blue Lentic Belt. The outcomes of this study have emphasized the rapid expansion of the Blue Lentic Belt and its negative impacts on local and downstream aquatic habitats, which calls for attention to systemic investigations by multiple disciplines.
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  • 文章类型: Journal Article
    根据美国疾病控制和预防中心的数据,大约8%的美国人在平均季节感染流感。有必要加强对流感的预警和对公众健康的预测。在这项研究中,使用空间自相关分析和空间扫描分析来确定美国流感样疾病(ILI)患病率的时空模式,在2011-2020传输季节。构建了季节性自回归综合移动平均(SARIMA)模型来预测高危状态的流感发病率。我们发现ILI的发病率最高主要集中在路易斯安那州,哥伦比亚特区和弗吉尼亚州。密西西比州是一个高风险的州,流感发病率较高,并与邻近国家表现出一个高-高集群。SARIMA(1,0,0)(1,1,0)52模型适用于预测密西西比州的ILI发病率。实际值和预测值之间的相对误差表明预测值与实际值匹配良好。在美国,流感仍然是一个重要的健康问题。ILI的传播因季节和地理区域而异。流感的高峰期是冬季和春季,流感发病率较高的州集中在东南部。在高风险州加强监测可以帮助控制流感的传播。
    About 8% of the Americans contract influenza during an average season according to the Centers for Disease Control and Prevention in the United States. It is necessary to strengthen the early warning for influenza and the prediction of public health. In this study, Spatial autocorrelation analysis and spatial scanning analysis were used to identify the spatiotemporal patterns of influenza-like illness (ILI) prevalence in the United States, during the 2011-2020 transmission seasons. A seasonal autoregressive integrated moving average (SARIMA) model was constructed to predict the influenza incidence of high-risk states. We found the highest incidence of ILI was mainly concentrated in the states of Louisiana, District of Columbia and Virginia. Mississippi was a high-risk state with a higher influenza incidence, and exhibited a high-high cluster with neighboring states. A SARIMA (1, 0, 0) (1, 1, 0)52 model was suitable for forecasting the ILI incidence of Mississippi. The relative errors between actual values and predicted values indicated that the predicted values matched the actual values well. Influenza is still an important health problem in the United States. The spread of ILI varies by season and geographical region. The peak season of influenza was the winter and spring, and the states with higher influenza rates are concentrated in the southeast. Increased surveillance in high-risk states could help control the spread of the influenza.
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  • 文章类型: Journal Article
    亚硝酸盐(NO2-)敏化的光解在减弱废水衍生的痕量有机污染物中起着重要作用(例如,苯胺,酚类化合物,等。)在地表水中。然而,动力学,机制,许多被NO2-敏化的新兴污染物的光解的影响因素仍然未知。在这里,我们报道了在紫外线365nm(UV365)辐射下,NO2-敏化了抗菌剂对氯对苯二甲酚(PCMX)和氯苯(CP)在水溶液中的光解。随着NO2-浓度的增加,PCMX和CP的光解速率常数非线性增加。自由基猝灭研究和动力学模型表明,羟基自由基(HO•)和二氧化氮自由基(NO2•)对PCMX和CP的去除起主要作用。固相萃取(SPE)结合高分辨率质谱(HR-MS)分析确定了一系列中间产物,包括羟基化,硝化,硝化,和二聚衍生物。同位素标记的亚硝酸盐(15NO2-)的实验表明,中间产物的硝基和亚硝基取代基是由亚硝酸盐氮衍生的。根据确定的产品和理论计算,阐明了PCMX和CP的NO2-敏化光解的机理和途径。脱氧部分抑制了4-氯-3,5-二甲基-2-硝基苯酚(硝基-PCMX)的形成,而HO•清除剂如异丙醇(i-PrOH)的存在抑制了硝基-PCMX的进一步转化。密西西比河天然有机物(MRNOM)的存在抑制了PCMX和CP的去除,可能是由于光屏蔽和自由基猝灭。然而,在废水和湿地水基质中仍观察到PCMX和CP的明显降解。这项研究的结果为在太阳辐射下富含NO2的废水或受废水影响的地表水中PCMX和CP的转化和命运提供了一些启示。
    Nitrite (NO2-)-sensitized photolysis plays an important role in the attenuation of effluent-derived trace organic contaminants (e.g., anilines, phenolic compounds, etc.) in surface waters. However, the kinetics, mechanisms, and influencing factors of photolysis of many emerging contaminants sensitized by NO2- still remain largely unknown. Herein, we report that NO2--sensitized photolysis of the antimicrobial agents parachlormetaxylenol (PCMX) and chlorophene (CP) in aqueous solution under ultraviolet 365 nm (UV365) radiation. A nonlinear increase in photolysis rate constants of PCMX and CP was observed with increasing NO2- concentration. Radical quenching studies and kinetic modeling revealed that hydroxyl radical (HO•) and nitrogen dioxide radicals (NO2•) contributed dominantly to the removal of PCMX and CP. Solid phase extraction (SPE) combined with high resolution-mass spectrometry (HR-MS) analysis identified a series of intermediate products including hydroxylated, nitrated, nitrosated, and dimerized derivatives. Experiments with isotopically labelled nitrite (15NO2-) showed that the nitro- and nitroso-substituents of intermediate products were derived from the nitrite nitrogen. Based on the identified products and theoretical computations, the mechanisms and pathways of NO2--sensitized photolysis of PCMX and CP are elucidated. Deoxygenation partially inhibited the formation of 4-chloro-3,5-dimethyl-2-nitrophenol (nitro-PCMX) while the presence of HO• scavenger such as isopropanol (i-PrOH) suppressed the further transformation of nitro-PCMX. The presence of Mississippi River natural organic matter (MRNOM) inhibited the removal of PCMX and CP, likely due to light screening and radical quenching. However, appreciable degradation of PCMX and CP was still observed in wastewater and wetland water matrices. Results of this study shed some light on the transformation and fate of PCMX and CP in NO2--rich wastewater effluents or effluent-impacted surface waters under solar radiation.
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  • 文章类型: Journal Article
    Recently, the exposure of nanoplastics (NPs) in the environment has received extensive attention. Research concerning their fate and transport in the aquatic environment is very important and urgent. In this study, the influence of two sources of natural organic matter (NOM) on the behaviour of NPs were investigated in view of the complexity of NOM. Humic acid (HA), Suwannee River humic acid (SRHA) and Upper Mississippi River NOM (MRNOM) were chosen to represent pedogenic NOM, while bovine serum albumin (BSA) was on behalf of aquagenic NOM. The results showed that NOM could reduce the aggregation and sedimentation of NPs, exhibiting excellent stabilization effect. The stability effect was affected by the concentrations and the sources of NOMs. For pedogenic NOMs, the stabilization effect was caused by adsorption modes with different microscopic morphologies through specific functional groups, while it was induced by the mode of steric stabilization in the presence of BSA. Spectroscopic method and micromorphology study further provided a new insight into exploring the possible mechanism of the interaction between NPs and NOMs.
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  • 文章类型: Journal Article
    Changing environments of temperature, precipitation and moisture availability can affect vegetation in ecosystems, by affecting regeneration from the seed bank. Our objective was to explore the responses of soil seed bank germination to climate-related environments along geographic gradients. We collected seed banks in baldcypress (Taxodium distichum) swamps along the Mississippi River and the Gulf of Mexico Coast in the United States, which have distinct temperature and/or precipitation gradients, and germinated them in a greenhouse. The frequency, richness and seed density of species germinated from the seed bank were compared between various geographic locations, experimental water regimes (saturated, flooded) and wetland types (tidal, non-tidal and inland swamps). We also analyzed the relationship of seed density to the environment by using a Non-metric Multi-dimensional Scaling (NMDS) model. Sixty-one species germinated from the seed bank, differing in pattern by geographic location, experimental water regime and wetland type. The foundation species (i.e., T. distichum and Cephalanthus occidentalis) germinated with a niche affinity for the northern part of the latitudinal gradient (Tennessee and Illinois) and these species may shift northward with climate change. Some species had higher seed density in the locations that were subject to more persistent drought conditions (e.g., Texas) including Cyperus rotundus and Gratiola virginiana, indicating that these species may be better adapted to sites with high temperature and low precipitation. In contrast, certain species including Saururus cernuus and Ludwigia palustris were present throughout the range of these gradients, and so may be more resilient to any future climate shifts. We found that the regeneration potential of baldcypress swamps might be altered by changes in local and climate environment because of nuances of responses of seed banks to climates along latitudinal and longitudinal gradients. Our study can help predict vegetation regeneration potential to climate change environments depending on the ability of these species to disperse and maintain seed banks.
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  • 文章类型: Journal Article
    Flooding displaces large populations each season, which potentially increases the exposure of the vulnerable societies. Having failed to curve down the number of people infected with COVID-19 in the first wave of the pandemic, many states in the United States (U.S.) are now at high risk of the concurrence of the two disasters. Assessing this compound risk before the country enters the flood season is of vital importance. Therefore, we provide a prompt tool to assess the compound risk of COVID-19 at the county level over the U.S. We find that (1) the number of flood insurance house claims can proxy the displaced population accurately with more spatiotemporal detail, and (2) the high-risk areas of both flooding and COVID-19 are concentrated along the southern and eastern coasts and some parts of the Mississippi River. Our findings may trigger the interest of further exploring the topics related to the concurrence of COVID-19 and flooding.
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  • 文章类型: Journal Article
    Framework-forming scleractinian (FFS) corals provide structurally complex habitats to support abundant and diverse benthic communities but are vulnerable to environmental changes and anthropogenic disturbances. Scientific modeling of suitable habitat provides important insights into the impact of the environmental conditions and fills the gap in the knowledge on habitat suitability. This study presents predictive habitat suitability modeling for deep-sea (depth > 50 m) FFS corals in the GoM. We first conducted a nonparametric estimate of the observed coral point process intensity as a function of each numeric environmental variable. Next, we performed species distribution modeling (SDM) using an assemble of four machine learning models - maximum entropy (ME), support vector machine (SVM), random forest (RF), and deep neural network (DNN). We found that most important variables controlling the coral distribution are super-dominant gravel and rock substrata, SW and SE aspects, slope steepness, salinity, depth, temperature, acidity, dissolved oxygen, and chlorophyll-a. Highly suitable habitats are predicted to be on the continental slope off Texas, Louisiana, and Mississippi and the shelf and slope of the West Florida Escarpment. All the four models have outstanding prediction performances with AUC values over 0.95. DNN model performs best (AUC = 0.987). The study contributes to coral habitat modeling research by presenting unique methods including nonparametric function of coral point process intensity, DNN and SVM models that have not been used in coral SDM, post-classification model assembling, and percentile approach to determine a threshold value for classifying a suitability score map into a binary map. Our findings would help support conservation prioritization, management and planning, and guide new field exploration.
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