correlation analysis

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  • 文章类型: Journal Article
    水体富营养化严重威胁水质和人类健康,叶绿素a(Chla)是代表河流或湖泊富营养化的关键指标。了解Chla的时空分布及其准确预测对于水系统管理具有重要意义。在这项研究中,运用时空分析和相关分析揭示了富春河中Chla的浓度格局,中国。然后四个外生变量(风速,水温,溶解氧和浊度)通过六个模型(3个传统机器学习模型和3个深度学习模型)用于预测Chla浓度,并比较了具有不同水文特征的河流中的性能。统计分析表明,8月和9月,水库河段的Chla浓度高于自然河段,而优势藻类逐渐从蓝藻变成隐藻。此外,空气温度,环境因子中水温和溶解氧与Chla浓度有很高的相关性。预测模型的结果表明,极端梯度提升(XGBoost)和长短期记忆神经网络(LSTM)是水库河段(NSE=0.93;RMSE=4.67)和天然河段(NSE=0.94;RMSE=1.84)的最佳性能模型。分别。本研究为进一步了解不同类型河流的富营养化和藻华预警提供了参考。
    Eutrophication is a serious threat to water quality and human health, and chlorophyll-a (Chla) is a key indicator to represent eutrophication in rivers or lakes. Understanding the spatial-temporal distribution of Chla and its accurate prediction are significant for water system management. In this study, spatial-temporal analysis and correlation analysis were applied to reveal Chla concentration pattern in the Fuchun River, China. Then four exogenous variables (wind speed, water temperature, dissolved oxygen and turbidity) were used for predicting Chla concentrations by six models (3 traditional machine learning models and 3 deep learning models) and compare the performance in a river with different hydrology characteristics. Statistical analysis shown that the Chla concentration in the reservoir river segment was higher than in the natural river segment during August and September, while the dominant algae gradually changed from Cyanophyta to Cryptophyta. Moreover, air temperature, water temperature and dissolved oxygen had high correlations with Chla concentrations among environment factors. The results of the prediction models demonstrate that extreme gradient boosting (XGBoost) and long short-term memory neural network (LSTM) were the best performance model in the reservoir river segment (NSE = 0.93; RMSE = 4.67) and natural river segment (NSE = 0.94; RMSE = 1.84), respectively. This study provides a reference for further understanding eutrophication and early warning of algal blooms in different type of rivers.
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  • 文章类型: Journal Article
    该研究旨在调查气象参数与伊斯兰堡COVID-19大流行传播之间的相关性,巴基斯坦。气象参数包括最低温度(°C),最高温度(°C),温度平均值(°C),最小湿度(%),最大湿度(%),湿度平均值(%),降雨量(mm)。COVID-19的新确诊病例数和死亡人数等数据是从卫生部获得的,巴基斯坦。各种类型的相关性,即,皮尔森,斯皮尔曼,气象参数和COVID-19之间的Kendall相关性被用于数据分析。结果表明,COVID-19与所有气象参数中的最低温度和平均温度之间存在高度显着关系。研究结果可能有助于竞争当局在巴基斯坦与这种疾病作斗争。
    The study aimed to investigate the correlation between meteorological parameters and the spread of the COVID-19 pandemic in Islamabad, Pakistan. The meteorological parameters include temperature minimum (°C), temperature maximum (°C), temperature average (°C), humidity minimum (%), humidity maximum (%), humidity average (%), and rainfall (mm). The data of COVID-19, such as the number of new confirmed cases and deaths was obtained from the Ministry of Health, Pakistan. The correlations of various types, i.e., Pearson, Spearman, and Kendall correlations between meteorological parameters and COVID-19, were employed for data analyses. The results exhibited a highly significant relationship between COVID-19 and temperature minimum and temperature average among all meteorological parameters. The study findings may help competitive authorities to combat this disease in Pakistan.
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  • 文章类型: Journal Article
    近年来,由于交通事故和伤亡人数急剧增加,驾驶行为分析备受关注,根据许多研究,驾驶环境或行为与驾驶员状态之间存在关系。据我们所知,这些研究主要调查一个生命体征和驾驶环境之间的关系,无论是在室内或室外。因此,我们的论文提供了对驾驶员状态(生命体征,眼睛状态,和头部姿势)以及车辆操纵动作(由驾驶员引起)和外部事件(由其他车辆或行人执行),包括接近其他车辆。我们的方法采用了我们以前的工作中开发的几个模型来估计呼吸频率,心率,血压,氧饱和度,头部姿势,来自机舱内视频的眼睛状态,以及车外视频到最近车辆的距离。此外,使用卷积神经网络(CNN)和双向长短期记忆(BiLSTM)开发了新模型,以将外部事件从舱外视频中分类,以及使用加速度计和陀螺仪传感器数据检测驾驶员操纵的决策树分类器。使用的数据集包括同步的机舱内/机舱外视频和传感器数据,允许估计驾驶员状态,接近其他车辆和检测外部事件,和驾驶员操纵。因此,计算所有待分析变量之间的相关矩阵。结果表明,一侧的机动动作和超车外部事件与另一侧的心率和血压(收缩压和舒张压)之间存在弱相关性。此外,研究结果表明,头部的偏航角与超车事件之间存在相关性,收缩压与距最近车辆的距离之间存在负相关。我们的发现与我们最初的假设一致,特别是关于执行机动或经历谨慎事件的影响,比如超车,由于此类事件引起的激动和紧张,对心率和血压的影响。这些结果可能是实施复杂的安全系统的关键,该系统旨在在发生激进的外部事件或操纵时保持驾驶员的稳定状态。
    Driving behaviour analysis has drawn much attention in recent years due to the dramatic increase in the number of traffic accidents and casualties, and based on many studies, there is a relationship between the driving environment or behaviour and the driver\'s state. To the best of our knowledge, these studies mostly investigate relationships between one vital sign and the driving circumstances either inside or outside the cabin. Hence, our paper provides an analysis of the correlation between the driver state (vital signs, eye state, and head pose) and both the vehicle maneuver actions (caused by the driver) and external events (carried out by other vehicles or pedestrians), including the proximity to other vehicles. Our methodology employs several models developed in our previous work to estimate respiratory rate, heart rate, blood pressure, oxygen saturation, head pose, eye state from in-cabin videos, and the distance to the nearest vehicle from out-cabin videos. Additionally, new models have been developed using Convolutional Neural Network (CNN) and Bidirectional Long Short-Term Memory (BiLSTM) to classify the external events from out-cabin videos, as well as a Decision Tree classifier to detect the driver\'s maneuver using accelerometer and gyroscope sensor data. The dataset used includes synchronized in-cabin/out-cabin videos and sensor data, allowing for the estimation of the driver state, proximity to other vehicles and detection of external events, and driver maneuvers. Therefore, the correlation matrix was calculated between all variables to be analysed. The results indicate that there is a weak correlation connecting both the maneuver action and the overtaking external event on one side and the heart rate and the blood pressure (systolic and diastolic) on the other side. In addition, the findings suggest a correlation between the yaw angle of the head and the overtaking event and a negative correlation between the systolic blood pressure and the distance to the nearest vehicle. Our findings align with our initial hypotheses, particularly concerning the impact of performing a maneuver or experiencing a cautious event, such as overtaking, on heart rate and blood pressure due to the agitation and tension resulting from such events. These results can be the key to implementing a sophisticated safety system aimed at maintaining the driver\'s stable state when aggressive external events or maneuvers occur.
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  • 文章类型: Journal Article
    多环芳烃(PAHs)和黑碳(BC)通常在PM2.5中共存,因为两者都是在有机物不完全燃烧期间形成的。这些化合物被视为具有潜在健康影响的有害空气污染物,包括呼吸和心血管的影响。在这项研究中,为了评估台湾北部城市地区PAHs和BC的健康风险,16优先PAHs和BC,由美国环境保护局确定,在PM2.5中进行分析和定量,以确定它们的浓度,他们之间的关系,和他们可能的来源。结果表明,总PAHs和BC的平均浓度分别为0.91ngm-3和0.97μgm-3,它们之间存在显著的正相关,表示相同的排放源。结果还表明,化石燃料燃烧和交通排放是PAHs的主要贡献者,木材和生物质燃烧的作用不太突出。在这16种优先PAHs中,苯并[a]芘,dibenz[a,h]蒽,苯并[b]荧蒽,和茚并[1,2,3-cd]芘是主要的致癌化合物,占总致癌毒性的89.0%。因此,PAH暴露导致的终生超额癌症风险估计为8.03×10-6,这表明采样点存在对人类健康的潜在致癌风险.总的来说,这项研究强调了未来交通排放和化石燃料燃烧缓解政策的必要性,以减少台湾北部BC和共同生产的PAHs的本地排放。
    Polycyclic aromatic hydrocarbons (PAHs) and black carbon (BC) often coexist in PM2.5 because both form during the incomplete combustion of organic matter. These compounds are regarded as hazardous air pollutants with potential health effects, including respiratory and cardiovascular effects. In this study, to evaluate the health risks of PAHs and BC at an urban site in northern Taiwan, 16 priority PAHs and BC, identified by the United States Environmental Protection Agency, were analyzed and quantified in PM2.5 to determine their concentrations, their relationship with each other, and their likely sources. The results indicated that the mean concentrations of total PAHs and BC were 0.91 ng m-3 and 0.97 μg m-3, respectively, with a significant positive correlation between them, indicating the same emission sources. The results also indicated that fossil fuel combustion and traffic emissions were primary contributors to PAHs, with wood and biomass combustion playing a less prominent role. Among these 16 priority PAHs, benzo[a]pyrene, dibenz[a,h]anthracene, benzo[b]fluoranthene, and indeno[1,2,3-cd]pyrene served as major carcinogenic compounds, accounting for 89.0% of the total carcinogenic toxicity. Thus, the lifetime excess cancer risk resulting from PAH exposure was estimated as 8.03 × 10-6, indicating a potential carcinogenic risk to human health at the sampling site. Overall, this study highlights the need for future mitigation policies for traffic emissions and fossil fuel combustion for reducing the local emissions of BC and co-produced PAHs in northern Taiwan.
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  • 文章类型: English Abstract
    随着城市规模的不断扩大,改变了该地区的土地覆盖类型,大量的自然景观被人造景观所取代,环境温度上升。研究城市空间格局与热环境的响应关系,为改善生态环境、优化城市空间布局提供一定的指导。基于合肥市2020年Landsat8系列遥感影像数据和ENVI、ARCGIS等分析平台,皮尔逊相关和剖面线被用来反映两者之间的相关性。然后,选取相关性最大的3个空间格局分量,构建多元回归函数,研究城市空间格局对城市热环境的影响及其作用机制。结果表明:①2013-2020年合肥市高温区随时间的提前而显著增加。对于不同的季节,城市热岛效应表现为夏季>秋季>春季>冬季。②在中心城区,建筑物占用,建筑物高度,不透明的占用,人口密度明显高于郊区,而部分植被覆盖度的郊区高于市区,主要表现为市区的点分布和水体的不规则分布。③城市高温区主要分布在城市各开发区,而城市地区的其他地方则以中高温和高温分区为主,郊区以中低温为主。④各要素空间格局与热环境之间的皮尔逊系数与建筑物占有率呈正相关(0.395),不透水表面占有率(0.333),人口密度(0.481),和建筑物高度(0.188),并与植被覆盖度(-0.577)和水占有率(-0.384)呈负相关。构造的多元回归函数的系数,包括建筑物占用,人口密度,和部分植被覆盖率,分别为8.372、0.295和-5.639,常数为38.555。研究结果可为优化城市空间布局、提高城市居住质量提供参考依据。
    With the continuous expansion of cities, the land cover type of the region is transformed, a large number of natural landscapes are replaced by man-made landscapes, and the environmental temperature rises. The study of the response relationship between urban spatial pattern and thermal environment provides some guidance for improving the ecological environment and optimizing the urban spatial layout. Based on the Landsat 8 series remote sensing image data of Hefei City in 2020 and analysis platforms such as ENVI and ARCGIS, Pearson correlation and profile lines were used to reflect the correlation between the two. Then, the three spatial pattern components with the greatest correlation were selected to construct multiple regression functions to investigate the influence of urban spatial pattern on urban thermal environment and its mechanism of action. The results showed that:① the high temperature area of Hefei City increased significantly with the advance of time during 2013-2020. For different seasons, the urban heat island effect showed that summer>autumn>spring>winter. ② In the central urban area, the building occupancy, building height, imperviousness occupancy, and population density were significantly higher than those in the suburbs, whereas fractional vegetation coverage presented a higher suburban than urban area and mainly showed a point distribution in the urban area and an irregular distribution of water bodies. ③ The urban high-temperature zone was mainly distributed in various development zones in urban areas, whereas other places in urban areas were dominated by medium-high temperature and above-temperature zoning, and suburban areas were dominated by medium-low temperature. ④ The Pearson coefficients between the spatial pattern of each element and the thermal environment were positively correlated with the building occupancy (0.395), impervious surface occupancy (0.333), population density (0.481), and building height (0.188) and negatively correlated with fractional vegetation coverage (-0.577) and water occupancy (-0.384). The coefficients of the constructed multiple regression functions, including building occupancy, population density, and fractional vegetation coverage, were 8.372, 0.295, and -5.639 respectively, with a constant of 38.555. The results of this study can provide a reference basis for optimizing urban spatial layouts and improving urban living quality.
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  • 文章类型: Journal Article
    COVID-19在2020年严重影响了世界。以中国2020年和2022年的两次疫情为例,分析了地表水质量水平和CODMn和NH3-N浓度的时空变化,并评估了两种污染物的变化与环境和社会因素之间的关系。结果显示在两次封锁期间,由于总用水量(包括工业,农业,和生活用水)减少,水质良好的比例分别提高了6.22%和4.58%,污水比例分别下降6.00%和3.98%,水环境质量明显改善。然而,进入解锁期后,水质优良比例下降6.19%。在第二次封锁期之前,CODMn的平均浓度呈下降趋势,上升,和下降趋势,而平均NH3-N浓度的变化方向相反。相关分析表明,污染物浓度的增加趋势与经纬度呈正相关,与DEM和降水弱相关。NH3-N浓度略有下降趋势与种群密度变化呈负相关,与温度变化呈正相关。省级地区确诊病例数变化与污染物浓度变化的关系不确定,正相关和负相关。这项研究证明了封锁对水质的影响以及通过人为调节改善水质的可能性,可为水环境管理提供参考依据。
    The COVID-19 severely affected the world in 2020. Taking the two outbreaks in China in 2020 and 2022 as examples, the spatiotemporal changes in surface water quality levels and CODMn and NH3-N concentrations were analyzed, and the relationships between the variations in the two pollutants and environmental and social factors were evaluated. The results showed that during the two lockdowns, due to the total water consumption (including industrial, agricultural, and domestic water) decreased, the proportion of good water quality increased by 6.22% and 4.58%, and the proportion of polluted water decreased by 6.00% and 3.98%, the quality of water environment has been improved significantly. However, the proportion of excellent water quality decreased by 6.19% after entering the unlocking period. Before the second lockdown period, the average CODMn concentration exhibited a \"falling, rising, and falling\" trend, while the average NH3-N concentration changed in the opposite direction. The correlation analysis revealed that the increasing trend of pollutant concentrations was positively correlated with longitude and latitude, and weakly correlated with DEM and precipitation. A slight decrease trend in NH3-N concentration was negatively correlated with the population density variation and positively correlated with the temperature variation. The relationship between the change in the number of confirmed cases in provincial regions and the change in pollutant concentrations was uncertain, with positive and negative correlations. This study demonstrates the impact of lockdowns on water quality and the possibility of improving water quality through artificial regulation, which can provide a reference basis for water environmental management.
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  • 文章类型: Journal Article
    未经证实:筛选和鉴定肺结核(PTB)的血液学分子指标对其诊断和治疗至关重要。因此,我们的工作目的是检测血液标志物B和T淋巴细胞衰减因子(BTLA)在PTB中的诊断价值,为PTB的辅助诊断提供一定的理论依据。
    未经评估:根据纳入标准,选取我院2020年1月至2021年12月临床确诊的56例肺结核患者作为研究对象。以我院52名匹配的健康人群作为对照组。从临床实验室获得临床特征。实时聚合酶链反应(RT-PCR)用于分析BTLA及其配体在外周血中的变化。通过流式细胞术分析不同细胞表面上BTLA的变化。相关性检验用于确定BTLA与临床指标之间的关联。采用受试者工作特征(ROC)曲线分析评价不同来源BTLA表达在PTB中的辅助诊断价值。
    UNASSIGNED:与对照组相比,PTB组外周血BTLA的变化显着增加(P=0.0187),而不是其配体。PTB组CD68和抗原提呈细胞(APC)CD11c表面BTLA的变化显著增加(P=0.0004,P<0.0001),而BTLA在CD4+T和CD8+T细胞表面的变化无显著差异(P=0.0792,P=0.8706)。BTLA+CD11c+的表达与免疫球蛋白A(IgA)的表达呈负相关(r=-0.2934,P=0.0282),与C反应蛋白呈正相关(r=0.3277,P=0.0137)。ROC曲线分析表明曲线下面积(AUC),BTLART-PCR检测的敏感性和特异性分别为0.6315、53.57%,57.69%,BTLA+CD11c+检测分别为0.8039、88.46%和73.21%,BTLA+CD68+检测分别为0.6973、60.71%和61.54%。
    UNASSIGNED:BTLA在PTB患者的外周血和特定细胞类型中高表达,并与特定的临床指标相关。可能是PTB辅助诊断的重要分子标志物。
    UNASSIGNED: Screening and identification of hematologic molecular indicators of pulmonary tuberculosis (PTB) is crucial for its diagnose and therapy. Therefore, our work aims to detect the diagnostic value of blood marker B and T lymphocyte attenuator (BTLA) in PTB, and provide a certain theoretical basis for the auxiliary diagnosis of PTB.
    UNASSIGNED: Based on the inclusion criteria, 56 Patients with clinically confirmed pulmonary TB by clinical between January 2020 and December 2021 at our hospital were selected as the research objects of this study. Fifty-two matched healthy population at our hospital was used as the control group. Clinical characteristics were got from clinical laboratory. Real-time polymerase chain reaction (RT-PCR) was used to analyze changes in BTLA along with its ligand in peripheral blood. Changes in BTLA on the surface of different cells were analyzed by flow cytometry. The correlation test was used to determine the associations between BTLA and clinical indicators. Receiver operating characteristic (ROC) curve analysis was used to evaluate the auxiliary diagnostic value in PTB of BTLA expression from different sources.
    UNASSIGNED: Compared with the control, changes in peripheral blood BTLA in the PTB group were significantly increased (P=0.0187) rather than its ligand. Changes in BTLA on the surface of CD68 and antigen-presenting cell (APC) CD11c were significantly increased in the PTB group (P=0.0004, P<0.0001), while changes in BTLA on the surface of CD4+ T and CD8+ T cells were not significantly different (P=0.0792, P=0.8706). The expression of BTLA+CD11c+ was negatively correlated with the expression of immunoglobulin A (IgA) (r=-0.2934, P=0.0282) and positively related to C-reactive protein (r=0.3277, P=0.0137). ROC curve analysis suggested that the area under the curve (AUC), sensitivity and specificity of BTLA RT-PCR detection were 0.6315, 53.57%, 57.69% while for BTLA+CD11c+ detection were 0.8039, 88.46% and 73.21% and for BTLA+CD68+ detection were 0.6973, 60.71% and 61.54%.
    UNASSIGNED: BTLA is highly expressed in peripheral blood and specific cell types of patients with PTB and is correlated with specific clinical indicators, which may be an important molecular marker for the auxiliary diagnosis of PTB.
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  • 文章类型: English Abstract
    近年来,城市臭氧(O3)污染问题日益突出。然而,与O3污染相关的气象因素尚不清楚。苏州市O3污染特征分析,作为一个典型的城市,探索O3污染的高影响气象因素对该地区的空气污染防治至关重要。本研究利用苏州市环境监测中心提供的O3浓度数据和苏州市2015年4-9月的同期气象观测资料,采用相关分析和机器学习方法,分析了苏州市O3浓度的变化及其与气象驱动因子之间的关系。结果表明:①近6年臭氧季臭氧污染超标率在20%以上,O3的污染天数和主要污染物O3的污染天数逐年增加。显然,O3污染问题日益突出。②O3的日变化为单峰,谷点在07:00,最高峰在15:00至16:00。在气温和太阳辐射的日变化中也发现了类似的趋势,但是每日最高峰比O3早。结果还显示,在2017年和2019年,O3浓度具有明显的周末效应,并且在一周内O3浓度与太阳辐照度之间存在显着相关性。此外,O3浓度和污染超标率的月变化是双峰的。③臭氧污染的发生受各种气象条件的影响。每日日照时数超过7小时时出现的最大天数,每日最高气温在30℃左右,太阳辐照度为350至440kW·m-2,相对湿度为50%至75%,当时污染的强度是最强的。当东风风速小于1.5m·s-1或西南风风速小于3.5m·s-1时,臭氧发生中度污染。④建立了基于机器学习的O3浓度优化预测模型,对4月份O3浓度有很好的预测能力,May,七月,和9月,但当O3浓度超过200μg·m-3时表现不佳。同时,发现太阳辐射对O3浓度的影响最明显,其次是相对湿度,而温度和风的重要性不如前两个因素。
    The problem of urban ozone (O3) pollution has become prominent in recent years. However, the meteorological factors associated with O3 pollution remain unclear. Analyzing the characteristics of O3 pollution in Suzhou, as a typical urban city, and exploring the high-impact meteorological factors with O3 pollution are crucial to the prevention and control of air pollution in this region. This study used correlation analysis and machine learning methods to analyze the variation in O3 concentration and the relationship between meteorological driving factors in Suzhou based on the O3 concentration data provided by Suzhou Environmental Monitoring Center and the contemporaneous meteorological observation data in Suzhou from April to September in 2015 to 2020. The results showed that: ① O3 pollution exceeding the standard rate was more than 20% in ozone seasons during the past six years; further, pollution days of O3 and the number of pollution days of O3 as the primary pollutant increased yearly. Evidently, the problem of O3 pollution has become increasingly prominent. ② The diurnal variations in O3 were unimodal with the valley point at 07:00 and the highest peak between 15:00 and 16:00. Similar trends were found in diurnal variations of both air temperature and solar radiation, but the daily highest peak came earlier than that of O3. The results also showed an apparent weekend effect of O3 concentration in 2017 and 2019 and a significant correlation between O3 concentration and solar irradiance during the week. In addition, the monthly variation in O3 concentration and pollution exceeding the standard rate was bimodal. ③The occurrence of ozone pollution was affected by various meteorological conditions. The maximum number of days appeared when daily sunshine hours lasted longer than 7 hours, with a daily maximum air temperature around 30℃, solar irradiance ranging from 350 to 440 kW·m-2, and relative humidity ranging from 50% to 75%, at which time the intensity of pollution was the strongest. When the wind speed of easterly wind was less than 1.5 m·s-1, or the wind speed of southwest wind was less than 3.5 m·s-1, moderate ozone pollution occurred. ④ An optimal prediction model of O3 concentration was established based on machine learning, which had good predictive ability for O3 concentration in April, May, July, and September but did not perform well when O3 concentration exceeded 200 μg·m-3. Meanwhile, it was found that solar radiation had the most obvious effect on O3 concentration, followed by relative humidity, whereas the temperature and wind were less important than the former two factors.
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  • 文章类型: Journal Article
    与传统的单代测试相比,多代毒性测试提供了更敏感的人群水平效应度量。特别是对于具有缓慢吸收速率的应激源(例如纳米材料),多代测试还可以提供更真实的自然暴露场景表示。迄今为止,然而,固有的高成本和劳动强度限制了多代毒性测试的使用,从而限制了它们在环境风险评估中的应用。因此,本研究的目的是确定在Daphniamagna毒性测试中常规测量的短期(er)终点在多大程度上保持对更长时间尺度上测量的繁殖的预测能力,包括多代人。为了评估这一点,进行了一个案例研究,其中在五代中评估了TiO2纳米颗粒(0、0.02、0.2、2和5mgL-1)对D.magna生活史特征的影响。此外,确定了在每一代暴露后,在清洁(非暴露)培养基中饲养来自暴露父母的后代是否表现出持续的不利影响。本研究表明,尽管在非暴露条件下,各种生活史特征与同一代和随后一代的总生殖产量相关,在暴露于nTiO2的情况下,这些相关性是解耦的。此外,发现nTiO2可以在浓度比以前发现的浓度低1-2个数量级(即0.02mgL-1)时对人群相关终点产生不利影响,接近自然淡水生态系统中的浓度范围。
    Multigenerational toxicity tests provide more sensitive measures of population-level effects than conventional single-generation tests. Particularly for stressors which exhibit slow uptake rates (e.g. nanomaterials), multigenerational tests may also provide a more realistic representation of natural exposure scenarios. To date, the inherently high costs and labor intensity have however limited the use of multigenerational toxicity tests and thereby their incorporation in environmental risk assessment. The aim of the present study was therefore to determine to what extent short(er) term endpoints which are conventionally measured in Daphnia magna toxicity tests hold predictive capacity towards reproduction measured over longer timescales, including multiple generations. To assess this, a case-study was performed in which effects of TiO2 nanoparticles (0, 0.02, 0.2, 2 and 5 mg L-1) on D. magna life-history traits were assessed over five generations. Additionally, it was determined whether offspring derived from exposed parents exhibited sustained adverse effects when rearing them in clean (non-exposed) media after each generation of exposure. The present study showed that although various life-history traits correlate with the total reproductive output in the same- and subsequent generation under non-exposed conditions, these correlations were decoupled in presence of exposure to nTiO2. In addition, it was found that nTiO2 can induce adverse effects on population relevant endpoints at concentrations 1-2 orders of magnitude lower than previously found (i.e. 0.02 mg L-1), and close to the range of concentrations occurring in natural freshwater ecosystems.
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  • 文章类型: Journal Article
    重金属在地表水和沉积物中的长期滞留和积累对水生生态系统的可持续发展和人类健康构成巨大威胁。在这项研究中,大型底栖动物,和地表水和沉积物重金属(锰,Cr,Cu,Ni,Pb,Zn,Cd,和As)样本于2019-2020年夏季从黑河上游和中游23处采集。通过Pearson相关分析和冗余分析(RDA)分析重金属与大型底栖动物的相互关系,用综合污染指数(WQI)评价地表水和沉积物中重金属的污染水平和潜在生态风险,单一潜在生态风险指数([公式:见正文]),和沉积物质量准则商(SQG-Q),分别。结果表明,黑河地表水重金属污染水平极低,但是Mn和Pb的含量超过了地表水环境质量标准(GB3838-2002)的第三类标准。表层沉积物中重金属的空间分布差异显著,8种重金属的平均浓度超过甘肃省的背景值。同时,表层沉积物中重金属的污染程度为高污染,生态风险等级为中度风险。结合[公式:见正文]和SQG-Q评估表明,Cd,Ni,Cr和Cr是主要的生态风险因子。此外,Cr和Cd的分布系数较低,表明Cr和Cd容易从表层沉积物中释放出来,造成二次污染。就重金属的来源而言,Cu,As,Zn,Cr,Ni主要来自工业和农业废水,铅来自采矿业和天然来源,Mn和Cd主要来自尾矿及其垃圾渗滤液。Basommatophora和Araneae可以用作地表水中重金属污染的潜在指示生物,和Basommatophora,鞘翅目,半翅目,Araneae可作为表层沉积物重金属污染的指示物种。研究表明,黑河地表水和沉积物中的大型无脊椎动物群落特征对重金属具有敏感的响应,可用于评价内河重金属污染状况。
    Long-term retention and accumulation of heavy metals in surface water and sediment pose a great threat to the sustainable development of aquatic ecosystems and human health. In this research, macrozoobenthos, and surface water and sediment heavy metal (Mn, Cr, Cu, Ni, Pb, Zn, Cd, and As) samples were collected from 23 sites in the upper and middle reaches of the Heihe River in the summers of 2019-2020. The interrelationships between heavy metals and macrozoobenthos were analyzed by Pearson correlation analysis and redundancy analysis (RDA), and the contamination level and potential ecological risk of the heavy metals in surface water and sediments were assessed by comprehensive pollution index (WQI), single potential ecological risk index ([Formula: see text]), and sediment quality guideline-quotient (SQG-Q), respectively. The results showed that the level of heavy metal pollution in the surface water of the Heihe River was extremely low, but the contents of Mn and Pb exceeded the third class of surface water environmental quality standards (GB 3838-2002). The spatial distribution of heavy metals in surface sediments were significantly different, and the average concentration of 8 heavy metals exceeded the background values of Gansu Province. Meanwhile, the pollution level of heavy metals in surface sediments was high pollution, and the ecological risk level was moderate risk. Combining [Formula: see text] and SQG-Q evaluations showed that Cd, Ni, and Cr were the main ecological risk factors. In addition, the distribution coefficients of Cr and Cd were low, indicating that Cr and Cd were easily released from the surface sediments, causing secondary pollution. In terms of the source of the heavy metals, Cu, As, Zn, Cr, and Ni mainly came from industrial and agricultural wastewaters, Pb was from the mining industry and natural sources, and Mn and Cd mainly came from tailings and their landfill leachate. Basommatophora and Araneae can be used as potential indicator organisms for heavy metal pollution in surface water, and Basommatophora, Coleoptera, Hemiptera, and Araneae can be used as indicator species for heavy metal pollution in surface sediments. The study showed that macroinvertebrate community characteristics had a sensitive response to heavy metals in the surface waters and sediments of the Heihe River, which can be used to evaluate the pollution status of heavy metals in inland rivers.
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