Urban green space (UGS) can be regarded as an effective approach to mitigate urban heat island (UHI) effects. Many studies have investigated the impacts of composition and configuration of UGS on ...land surface temperature (LST), while little attention has been paid to the impacts among different urban blocks. Thus, taking 1835 urban blocks in Beijing as samples, including low-rise point (LRP), low-rise street (LRS), low-rise block (LRB), mid-rise point (MRP), mid-rise street (MRS), mid-rise block (MRB), high-rise point (HRP), high-rise street (HRS) and high-rise block (HRB), this study investigated the impacts of UGS on LST among different urban blocks. The results showed that UGS serves as cold islands among different urban blocks. Percentage of landscape (PLAND) of UGS in all types of urban blocks, edge density (ED) of UGS in MRS, area-weighted fractal dimension index (FRAC_AM) of UGS in HRS and HRB show significantly negative impacts on LST, while aggregation index (AI) of UGS in LRP shows significantly positive impacts. The findings suggest that both composition and configuration of UGS can affect LST among different urban blocks and rational allocation of UGS would be effective for mitigating UHI effects.
Intrapartum fever is a well-known predisposing factor for severe perinatal outcomes. Herein, we explored the intrapartum features, obstetric outcomes, and neonatal outcomes in relation to the extent ...of intrapartum fever
three group analyses.
A retrospective cohort analysis consisting of 575 term, singleton live births in one medical center from January 1st to December 31st, 2020 was carried out. Parturients who had experienced a maximal intrapartum fever of <38.0 °C were compared with two sub-groups of parturients who had experienced respective maximal fevers of 38.0-38.9 °C and ≥39.0 °C. We computed the adjusted risks for adverse perinatal outcomes
multiple logistic regression models to control for confounders.
There were statistically remarkable differences among the three groups in 13 items including body mass index, epidural, and WBC before delivery (
< 0.05). In contrast with intrapartum fevers of 37.5-37.9 °C, intrapartum fevers of 38.0-38.9 °C were linked to an elevated risk of neonatal sepsis and neonatal intensive care unit admission with an odds ratio (OR) of 4.28 (95% CI 2.162-8.479) and 1.73 (95% CI 1.125-2.666), nonetheless, the relationship was remarkably higher for intrapartum fever ≥39.0 °C, with an OR of 6.40 (95% CI 2.450-16.725) and 2.23 (95% CI 1.021-4.854). Additionally, intrapartum fevers of 38.0-38.9 °C and ≥39.0 °C were related to remarkably higher risk for operative deliveries (OR 2.24, 95% CI 1.373-3.648; OR 3.59, 95% CI 1.398-9.226; respectively) and histological chorioamnionitis (OR 3.77, 95% CI 2.261-6.271; OR 19.24, 95% CI 7.385-50.111, respectively).
Intrapartum fever is an important indicator of adverse perinatal outcomes. The higher the temperature, the higher risk of histological chorioamnionitis, as well as the risk of neonatal sepsis and neonatal intensive care unit admission.
Intrapartum fever is a well-known risk factor for adverse perinatal outcomes. In this study, we evaluated the clinical features for intrapartum maternal fever and investigated the risk factors for ...neonatal early-onset sepsis (EOS) with intrapartum maternal fever.
This retrospective cohort study involved a total of 568 neonates born to mothers with intrapartum maternal fever (temperature peak ≥38 degree Celsius) in Hangzhou Women's Hospital from January 1st to December 31st, 2019. Neonates were assigned to the EOS and non-sepsis groups based on the diagnostic criteria for early-onset neonatal sepsis,. Demographic data, clinical information and laboratory test results were evaluated to assess the risk factors for EOS.
A total of 568 neonates were included in this study, 84 of whom were diagnosed with EOS. The EOS group was significantly different from the non-sepsis group in 11 items including the both white blood cell (WBC) count and C-reactive protein (CRP) level of the mother before delivery (
< 0.05). A logistic regression analysis revealed that a high maternal WBC count before delivery (OR = 3.261,
= 0.019) and a maternal histological chorioamnionitis (HCA) diagnosis (OR = 5.608,
= 0.002) were independent risk factors for EOS. The optimal cut-off value for WBC (before delivery) was 16.75 × 10*
/L for EOS, according to receiver operating characteristic analysis (area under curve was 0.821).
Elevated prenatal maternal WBC counts and maternal HCA diagnosis are both independently associated with EOS. Prenatal maternal WBC counts can be used as a sensitive indicator to predict EOS early.
Understanding the cooling effect (CE) of urban parks is vital to mitigate the urban heat islands. ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) land surface ...temperature data (LST) data were used to construct diurnal thermal variations to explore the CE of urban parks in the fifth ring regions of Beijing. Local climate zone (LCZ) classification was used to distinguish different parks for examining the internal CE of parks. New subclasses of LCZ (e.g., LCZAG, LCZBG, LCZCG) were created based on the basic subclasses, such as LCZA (mainly consist of dense trees), LCZB (scattered tress with dense bush), LCZC (scattered bush), and LCZG (water). The external CE of parks was evaluated in different directions, and the impacts of buildings around parks on the external CE were also analyzed. The results showed that urban parks tended to heat up slower than the whole urban regions during the daytime, and water releasing energy dominated the mean LST of parks at night. Large parks meeting the minimum area (40,000 m
2
) of LCZ had better CE inside each park during the daytime. Three hundred thirty four large parks were divided into six types of LCZ. The strength of the CE decrease with the increases of distance, and seemed to exist at a distance of up to 150–200 m. Such impacts of parks were insignificant at night. In addition, parks containing certain dense trees and water had better CE inside and out. The height and density of buildings had a relatively obvious impact on the CE of parks. This study can provide insight into the impacts of urban parks on the urban thermal environment and promote the CE of urban parks in future urban planning.
The development of ski areas would bring socio-economic benefits to mountain regions. At present, the ski industry in China is developing rapidly, and the number of ski areas is increasing ...dramatically. However, the understanding of the spatial pattern and driving factors for these ski areas is limited. This study collected detailed data about ski areas and their surrounding natural and economic factors in China. Criteria for classification of ski areas were proposed, and a total of 589 alpine ski areas in China were classified into three types: ski resorts for vacationing (va-ski resorts), ski areas for learning (le-ski areas) and ski parks to experience skiing (ex-ski parks), with proportions of 2.1%, 15.4% and 82.5%, respectively, which indicated that the Chinese ski industry was still dominated by small-sized ski areas. The overall spatial patterns of ski areas were clustered with a nearest neighbor indicator (NNI) of 0.424, in which ex-ski parks and le-ski areas exhibited clustered distributions with NNIs of 0.44 and 0.51, respectively, and va-ski resorts were randomly distributed with an NNI of 1.04. The theory and method of spatial autocorrelation were first used to analyze the spatial pattern and driving factors of ski areas. The results showed that ski areas in cities had a positive spatial autocorrelation with a Moran’s index value of 0.25. The results of Local Indications of Spatial Association (LISA) showed that ski areas were mainly concentrated in 3 regions: the Beijing-centered Yanshan-Taihang Mountains and Shandong Hill areas, the Harbin-centered Changbai Mountain areas and the Urumqi-centered Tianshan-Altay Mountain areas. The first location was mainly driven by socio-economic factors, and the latter two locations were mainly driven by natural factors. Ski tourism in China still faces many challenges. The government sector should strengthen supervision, develop a ski industry alliance, and promote the healthy and sustainable development of the ski industry in the future.
Urban morphology significantly affects the urban thermal environment. Seasonal impacts of two-dimensional (2D) and three-dimensional (3D) urban morphology on land surface temperature (LST) remain ...uncertain, and the impacts exist scale effects. Thus, taking Beijing as the study area, boosted regression tree (BRT) model was used to investigate the seasonal contributions of urban morphology to the thermal environment. Building density (BD), building height (BH), floor area ratio (FAR), sky view factor (SVF), and frontal area index (FAI), were used to comprehensively characterize urban morphology, and 13 scales ranging from 30 m to 600 m were used to investigate scale effects. The results showed that there are obvious spatial differences in LST and urban morphology indicators in the study area. 270 m was determined as the optimal scale for modeling in the study area. BH and BD are the domain indicators, which together contribute more than 75% of the variance of LST among four seasons, while the relative influences of SVF, FAR, and FAI are relatively low. Relationships between urban morphology indicators and LST are nonlinear among four seasons. The findings provide a scientific understanding for urban planners on mitigating the UHI effects through optimizing buildings.
•BRT model was applied to explore seasonal contributions of 2D/3D urban morphology to the thermal environment.•Scale effects for urban morphology analysis were explored.•Relative contribution and marginal effect of urban morphology indicators to LST across seasons were analyzed.•Rational allocation of BH and BD should be carried out to mitigate UHI effects.
Urban parks are regarded as a promising measure to alleviate urban heat island (UHI) effects. Park cooling effects have been widely investigated, however, the impacts of surrounding 2D/3D landscapes ...on it remain uncertain, especially in extreme hot weather. Therefore, taking 70 parks in Beijing as the samples, this study investigated the impacts of surrounding 2D/3D landscapes (vegetation, water, impervious surface, and buildings) on the park cooling effects in the extreme hot and normal days. First, based on buffer method, park cooling efficiency (PCE) was determined in the extreme hot and normal days. Then, both 2D (percentage of landscape (PLAND), landscape shape index (LSI), and aggregation index (AI)) and 3D (building density (BD), building height (BH), sky view factor (SVF), and frontal area index (FAI)) metrics were used to explore how surrounding 2D/3D landscapes influence PCE based on boosted regression tree (BRT) approach. The results showed that parks demonstrated the cooling islands, and the average PCE were 7.01 and 7.49 in the extreme hot and normal days, respectively. Surrounding buildings and vegetation metrics are the most important indicator in the extreme hot and normal days, respectively, which account for 30.6% and 47.1% of the contribution of PCE. The relationships between the key surrounding landscape metrics and PCE were nonlinear in the extreme hot and normal days. This study emphasized that surrounding 2D/3D landscapes can significantly affect park cooling effects, and the impacts are nonlinear. The findings are conducive to enhance the park cooling effects by optimizing the surrounding landscapes.
•BRT model was applied to explore the impacts of surrounding 2D/3D landscapes on PCE.•Relative importance of surrounding 2D/3D landscape metrics to PCE were analyzed.•Marginal effects of key influencing factors to PCE were explored.•Rational planning of park surrounding landscapes was proposed.
To determine the potential sources of dust at high latitudes in the Northern Hemisphere, this study measured the stable isotopic ratios of strontium (Sr), neodymium (Nd) and lead (Pb) in insoluble ...dust in snow samples (as well as in soil and sand samples) from sites in northwestern China and high latitudes in the Northern Hemisphere: Altay (Xinjiang, China), Ny-Ålesund (Svalbard), Barrow (Alaska) and the Arctic Ocean. The combined plots of the Sr–Nd–Pb isotopic data demonstrate that there are distinctive geographic patterns among the different sampling sites. The Sr–Nd results from the Altay (Xinjiang) and Ny-Ålesund (Svalbard) sites display overall crust-like isotopic patterns, indicating that local mineral sources represent a significant contribution. The 87Sr/86Sr and εNd(0) data from the sea ice snow samples from the Arctic Ocean and snow samples from Barrow (Alaska) suggest potential long-range dust transport to the Arctic region. Our results indicate that Russia may be a source of anthropogenic pollutants for the high Arctic region, while North America may be a source of anthropogenic pollutants for Barrow, Alaska. These findings are beneficial for protecting the environment at the global scale.
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•New Sr–Nd–Pb data from Arctic and western Chinese snow samples are presented.•East Asian deserts are the primary dust source for the Arctic regions.•The anthropogenic pollutants in Arctic regions may be from Russia and North America.
•Diurnal LST variations across different block types were analyzed.•Performances of BRT and RF in exploring the diurnal impacts were compared.•Relative importance of urban landscapes on diurnal LST ...were determined.•Nonlinear patterns between key urban landscapes and diurnal LST were revealed.•Landscapes optimization strategies were proposed to develop block thermal comfort.
Urban landscapes significantly affect land surface temperature (LST) and are considered crucial factors affecting urban heat island (UHI). The impacts of urban landscapes on LST have been extensively explored, mainly focusing on grid scale and the daytime. However, how 2D/3D urban landscapes affect diurnal LST at the block scale is unclear. Therefore, taking 1, 536 blocks (including low-rise blocks (LRB), middle-rise blocks (MRB), and high-rise blocks (HRB)) in Beijing as samples, the performances of boosted regression tree (BRT) and random forest (RF) were first evaluated, and the impacts of 2D/3D urban landscapes on diurnal LST across different block types were explored. The results showed that the mean LST was the highest in MRB (daytime) and HRB (nighttime). BRT performed better than RF in investigating diurnal impacts at the block scale. Vegetation and buildings are the domain factors influencing daytime and nighttime LST in LRB and MRB, while buildings are the domain factor in HRB except at 03:09 (impervious surface). The relationships between the key 2D/3D urban landscape metrics and block diurnal LST are nonlinear. The findings can serve as f basis for UHI mitigation and urban renewal strategies by urban planners to develop thermal comfort.
•Diurnal LST variations across different landscape types were compared.•Trees exhibit lower LST than low vegetation during the daytime and transition time.•3D landscapes exhibited a greater impact on ...diurnal LST than 2D landscapes.•Nonlinear relationships between key factors and diurnal LST were revealed.
The diverse urban features considerably influence land surface temperature (LST). Numerous studies have extensively investigated the impacts of 2D/3D urban features on LST. However, the diurnal impacts have not been comprehensively understood. Therefore, taking 1, 510 blocks within the 4th ring road of Beijing as samples, this study examined the influence of urban features (2D: low vegetation, water, and impervious surface; 3D: buildings and trees) on diurnal LST at the block scale based on ECOSTRESS LST using boosted regression tree (BRT) algorithm. The results showed that trees exhibit better cooling effects than low vegetation except at 3:09. The 3D features exhibited a greater impact on diurnal LST compared with 2D features, and it contributed strongly to daytime LST, which was 27.8 % on average higher than the 2D features. Building and tree densities had the greatest influence on daytime LST, while building height influenced nighttime LST the most. The impacts of key metrics on diurnal LST were nonlinear, and the relationship had diurnal variations. Taller buildings and trees were negatively correlated with LST during the daytime and transition time, but positively correlated with nighttime LST. The findings provide insights into landscape optimization strategies to improve block thermal comfort.
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