scholarly journals Analysis of the Spatial Distribution of Aedes Albopictus by Indicator Kriging in an Urban Area of Shanghai, China

2020 ◽  
Author(s):  
Yibin Zhou ◽  
Hongxia Liu ◽  
Peien Leng ◽  
Jiang Zhu ◽  
Shenjun Yao ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Spatial Autocorrelation ◽  
Urban Area ◽  
Aedes Albopictus ◽  
Urban Areas ◽  
Light Trap ◽  
Indicator Kriging ◽  
Surveillance Program ◽  
Temporal And Spatial Distribution ◽  
Positive Rate

Abstract Background: Aedes albopictus is a well-recognized vector of major arboviral diseases and a primary pest in tropical and temperate regions of China. In the current monitoring system for the spread of Ae. albopictus based on the sub-district scale in most cities of China, spatial distribution has not been considered for the analysis of the density of species. So, the system is not accurate enough for epidemic investigations, especially in big cities like Shanghai.Methods: In this study, an improved surveillance program integrating the actual monitoring locations was used to investigate the temporal and spatial distribution of Ae. albopictus abundance in an urban area of Shanghai, China, from 2018 to 2019 by using the mosquito-oviposition trap (MOT) method. The study area of 14 sub-districts was divided into 133 grids. The vector abundance and spatial structure of Ae. Albopictus were predicted by the indicator Kriging based on eight MOTs in each grid. Meanwhile, the light trap (LT) method was also used for the analysis and compared with the MOT method.Results: A total of 8,192 MOTs were placed in the study area in 2018, and 7,917 (96.6%) were retrieved with a positive rate of 6.45%, while in 2019, 22,715 (97.0%) of 23,408 MOTs were recovered with a positive rate of 5.44%. When using the LT method, 273 (93.5%) and 312 (94.5%) adult female Ae. albopictus were gathered in 2018 and 2019, respectively. The Ae. albopictus populations in the urban area of Shanghai increased slowly from May, reached a peak in July, and declined gradually from September. The MOT positivity index (MPI) showed a significant positive spatial autocorrelation across the study area, while LT collections indicated a non-significant spatial autocorrelation. The MPI was suitable for spatial interpolation by using the indicator Kriging and showed different hotspots in different years.Conclusions: The improved surveillance system integrating geographic information can help improve our understanding of the spatial and temporal distribution of Ae. albopictus in urban areas of Shanghai and could provide a practical method for decision-makers to implement vector control and management of mosquitoes.

scholarly journals Analysis of the Spatial Distribution of Aedes Albopictus by Indicator Kriging in an Urban Area of Shanghai, China

2020 ◽  
Author(s):  
Yibin Zhou ◽  
Hongxia Liu ◽  
Peien Leng ◽  
Jiang Zhu ◽  
Shenjun Yao ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Spatial Autocorrelation ◽  
Urban Area ◽  
Aedes Albopictus ◽  
Urban Areas ◽  
Light Trap ◽  
Indicator Kriging ◽  
Surveillance Program ◽  
Temporal And Spatial Distribution ◽  
Positive Rate

Abstract Background: Aedes albopictus is a well-recognized vector of major arboviral diseases and a primary pest in tropical and temperate regions of China. The current monitoring system, based on sub-district scale, in most cities of China for the spread of Ae. albopictus has not taken spatial distribution for the analysis of density of species. So it is not accurate enough for epidemic investigations, especially in big cities like Shanghai.Methods: In this study, a new surveillance program integrate the actual monitoring locations was used to investigate the temporal and spatial distribution of Ae. albopictus abundance in an urban area of Shanghai, China, from 2018 to 2019 by using the mosquito-oviposition trap (MOT) method. The study area of 14 sub-districts was divided into 133 grids with a side length of approximately 500 m. The vector abundance and spatial structure of Ae. Albopictus were predicted by the indicator Kriging based on eight MOTs in each grid. Meanwhile, the light trap (LT) method was also used for the analysis and compared with the MOT method.Results: A total of 8,192 MOTs were placed in the study area in 2018, and 7,917 (96.6%) were retrieved with a positive rate of 6.45%, while in 2019, 22,715 (97.0%) of 23,408 MOTs were recovered with a positive rate of 5.44%. When using the LT method, 273 (93.5%) and 312 (94.5%) adult female Ae. albopictus were gathered in 2018 and 2019, respectively. The Ae. albopictus populations in the urban area of Shanghai increased slowly from May, reached a peak in July, and declined gradually from September. The MOT positivity index (MPI) showed a significant positive spatial autocorrelation across the study area, while LT collections indicated a non-significant spatial autocorrelation. The MPI was suitable for spatial interpolation by using the indicator Kriging, and showed different hotspots in different years.Conclusions: The new surveillance system integrate geographic information can help improve our understanding of the spatial and temporal distribution of Ae. albopictus in urban areas of Shanghai and could provide a practical method for decision-makers to implement vector control and management of mosquitoes.

scholarly journals Analysis of the spatial distribution of Aedes albopictus in an urban area of Shanghai, China

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yibin Zhou ◽  
Hongxia Liu ◽  
Peien Leng ◽  
Jiang Zhu ◽  
Shenjun Yao ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Spatial Autocorrelation ◽  
Urban Area ◽  
Aedes Albopictus ◽  
Urban Areas ◽  
Light Trap ◽  
Kriging Model ◽  
Geographical Information ◽  
Surveillance Program ◽  
Positive Rate

Abstract Background Aedes albopictus is a vector of major arboviral diseases and a primary pest in tropical and temperate regions of China. In most cities of China, the current monitoring system for the spread of Ae. albopictus is based on the subdistrict scale and does not consider spatial distribution for analysis of species density. Thus, the system is not sufficiently accurate for epidemic investigations, especially in large cities. Methods This study used an improved surveillance program, with the mosquito oviposition trap (MOT) method, integrating the actual monitoring locations to investigate the temporal and spatial distribution of Ae. albopictus abundance in an urban area of Shanghai, China from 2018 to 2019. A total of 133 monitoring units were selected for surveillance of Ae. albopictus density in the study area, which was composed of 14 subdistricts. The vector abundance and spatial structure of Ae. albopictus were predicted using a binomial areal kriging model based on eight MOTs in each unit. Results were compared to the light trap (LT) method of the traditional monitoring scheme. Results A total of 8,192 MOTs were placed in the study area in 2018, and 7917 (96.6%) were retrieved, with a positive rate of 6.45%. In 2019, 22,715 (97.0%) of 23,408 MOTs were recovered, with a positive rate of 5.44%. Using the LT method, 273 (93.5%) and 312 (94.5%) adult female Ae. albopictus were gathered in 2018 and 2019, respectively. The Ae. albopictus populations increased slowly from May, reached a peak in July, and declined gradually from September. The MOT positivity index (MPI) showed significant positive spatial autocorrelation across the study area, whereas LT collections indicated a nonsignificant spatial autocorrelation. The MPI was suitable for spatial interpolation using the binomial areal kriging model and showed different hot spots in different years. Conclusions The improved surveillance system integrated with a geographical information system (GIS) can improve our understanding of the spatial and temporal distribution of Ae. albopictus in urban areas and provide a practical method for decision-makers to implement vector control and mosquito management. Graphical abstract

La cittŕ in-visibile. Analisi statistica spaziale degli stranieri nel comune di Roma

2009 ◽  
pp. 59-78
Author(s):  
Francesco Giovanni Truglia
Keyword(s):  
Spatial Distribution ◽  
Statistical Analysis ◽  
Urban Area ◽  
Urban Areas ◽  
Social Geography ◽  
Spatial Statistical Analysis ◽  
Units Of Analysis ◽  
The City ◽  
Statistical Indicators

- This contribution is aimed at builgin a sort of social geography of multicultural cohabitation in the municipality of Rome and identifying ethnic locations based a series of statistical indicators - some of which unpublished - with the use of certain instruments of spatial statistical analysis. The study is articulated on two levels. The first examines the urban areas and offers a horizontal overview of foreigners' spatial distribution. The second takes into consideration units of analysis referred to different administrative divisions (City, Municipality, urban area). This is a vertical analysis that takes into account the specific aspects of a certain urban area compared to the city and municipality of reference.

scholarly journals Spatial-Temporal Population Dynamics of Male and Female Aedes Albopictus at a Local Scale in Medellín, Colombia

2021 ◽  
Author(s):  
Carolina Camargo ◽  
Catalina Alfonso-Parra ◽  
Sebastián Díaz ◽  
Diego F. Rincón ◽  
Luis Felipe Ramírez-Sánchez ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Spatial Distribution ◽  
Aedes Albopictus ◽  
Climatic Variables ◽  
Vegetation Coverage ◽  
Female Size ◽  
Temporal And Spatial Distribution ◽  
Male And Female ◽  
Males And Females ◽  
Temporal And Spatial

Abstract Background: Diseases transmitted by invasive Aedes aegypti and Aedes albopictus mosquitoes are major public health issues in the tropics and subtropics. Understanding the ecology of mosquito vectors is essential for the development of effective disease mitigation programs and will allow for accurate predictions of vector occurrence and abundance. Studies that examine mosquito population dynamics are typically focused on female presence or total adult captures without discriminating the temporal and spatial distribution of both sexes. Methods: We collected immature and adult mosquitoes twice monthly during a two-year period (2018 – 2019) in the Medellín Botanical Garden (Medellín, Colombia) and assessed: 1) the relationship between climatic variables/vegetation coverage and adult captures, 2) the temporal and spatial distribution of Ae. aegypti and Ae. albopictus during the study period, 3) the temporal and spatial distribution of Ae. albopictus males and females, and 4) the correlation of male and female size in relation to climatic variables and vegetation coverage. Results: We show that Ae. albopictus was the predominant species in the park during the study period. Adult captures were positively correlated with precipitation and relative humidity, and inversely correlated with temperature and wind speed. Spatial analysis showed that Ae. aegypti and Ae. albopictus were distributed at different locations within the surveilled area. Moreover, we observed a spatial misalignment of Ae. albopictus males and females—the majority of males were located in the high vegetation coverage sites and the females in the medium vegetation coverage sites. Conclusions: Our work elucidates the differential dynamics of Ae. albopictus males and females, which is pivotal to develop accurate surveillance and the successful establishment of vector control programs based on the disruption of insect reproduction.

scholarly journals Analysis on Space accessibility of Medical Service Facilities in Central Wuhan Based on Improvement of 2SFCA

2021 ◽  
Vol 293 ◽  
pp. 02052
Author(s):  
Yi Wang ◽  
Jun Shao ◽  
Miao Xu ◽  
Changyou Wu ◽  
Yibang Li
Keyword(s):  
Spatial Distribution ◽  
Urban Area ◽  
Urban Areas ◽  
Spatial Accessibility ◽  
Transition Effect ◽  
The Third ◽  
Medical Institutions ◽  
Spatial Distribution Characteristics ◽  
Medical Facilities ◽  
Ring Line

Aiming at the current imperfect hierarchical diagnosis and treatment system and the unreasonable spatial distribution of medical facilities. This article introduces 2SFCA model improved by the Gaussian distance decay function and multiple stage radius to evaluate the accessibility of medical facilities in Wuhan. The results indicate that: firstly, compared with the traditional 2SFCA model, the improved 2SFCA model is more sensitive to the identification of spatial accessibility, and the transition effect of the identification results is more obvious, which can accurately reflect the spatial distribution characteristics of the accessibility of medical facilities in Wuhan. Secondly, the distribution of medical facilities in Wuhan is obvious and the main factors that affect the accessibility value in different urban areas are quite different. Thirdly, the high value areas of medical facilities in the main urban area of Wuhan are mainly concentrated within the second ring line, the transition effect between the second and third ring lines is obvious, and the low value areas are mainly concentrated outside the third ring line. In the end, the main reasons for the low accessibility of the area outside the Third Ring Road are the low service quantity and low service ability of the community health service institutions and the high traffic resistance. The research results can provide a reference for the layout and planning of medical institutions in the main urban area of Wuhan.

scholarly journals Research on the Temporal and Spatial Distribution and Influencing Factors of Forestry Output Efficiency in China

2021 ◽  
Vol 13 (9) ◽  
pp. 4687
Author(s):  
Yu Lin ◽  
Wenhui Chen ◽  
Junchang Liu
Keyword(s):  
Spatial Distribution ◽  
Spatial Autocorrelation ◽  
Malmquist Index ◽  
Fixed Effect ◽  
Practical Significance ◽  
Total Output ◽  
Eastern Region ◽  
Fixed Asset ◽  
Temporal And Spatial Distribution ◽  
Output Efficiency

Forestry output efficiency is key to forestry development. China is now promoting the development of forestry, and thus the research on forestry output efficiency is of practical significance. Through the data envelopment analysis (DEA)-Malmquist index, spatial autocorrelation model, and fixed effect model of panel data, in this study, we analyzed the forestry output efficiency of China with indicators, such as the fixed asset input, employed personnel, total output value, and timber output, and drew the following conclusions. In the time series, the forestry total-factor productivity (TFP) in China saw a rapid increase, which is attributed to the technological progress change (TC), whereas the efficiency change (EC) imposed negative influences upon the forestry TFP. In the spatial distribution, there was a difference in the increase in the forestry output efficiency among the eastern, central, and western regions of China, with the eastern region having the fastest growth and the central region having the slowest growth. According to the spatial autocorrelation, there was spatial aggregation (high–high (HH) and low–low (LL)) with a significant positive correlation. Through the optimized fixed effect regression model, the fixed asset input, employed personnel, total output value, and timber output all had significant influences on the comprehensive technical efficiency of the forestry output, wherein the input indicators had negative influences, and the output indicators had positive influences.

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