Spatially varying correlation between environmental conditions and human leptospirosis in Sarawak, Malaysia

@#The spatial distribution of environmental conditions may influence the dynamics of vectorborne diseases like leptospirosis. This study aims to investigate the global and localised relationships between leptospirosis with selected environmental variables. The association between environmental variables and the spatial density of geocoded leptospirosis cases was determined using global Poisson regression (GPR) and geographically weighted Poisson regression (GWPR). A higher prevalence of leptospirosis was detected in areas with higher water vapour pressure (exp(â): 1.12; 95% CI: 1.02 - 1.25) and annual precipitation (exp(â): 1.15; 95% CI: 1.02 - 1.31), with lower precipitation in the driest month (exp(â): 0.85; 95% CI: 0.75 – 0.96) and the wettest quarter (exp(â): 0.88; 95% CI: 0.77 – 1.00). Water vapor pressure (WVP) varied the most in the hotspot regions with a standard deviation of 0.62 (LQ: 0.15; UQ; 0.99) while the least variation was observed in annual precipitation (ANNP) with a standard deviation of 0.14 (LQ: 0.11; UQ; 0.30). The reduction in AICc value from 519.73 to 443.49 indicates that the GWPR model is able to identify the spatially varying correlation between leptospirosis and selected environmental variables. The results of the localised relationships in this study could be used to formulate spatially targeted interventions. This would be particularly useful in localities with a strong environmental or socio-demographical determinants for the transmission of leptospirosis.

Differences in spatial distribution of medicinal plant resources in Yinshan region of Inner Mongolia / 中国中药杂志

Yinshan Mountains stands on the southern edge of the Inner Mongolia Plateau, which stretches 1 200 km from east to west and 50 to 100 km from north to south. The rich and varied topographic environment of the Yinshan Mountains has created a variety of vegetation floras, which also makes the species of medicinal plant resources in this area unevenly distributed. Therefore, studying the spatial distribution difference of medicinal plant resources among various banners, counties, and districts in the Yinshan area is of great significance to formulate the protection policy and promote the industry development of medicinal plant. This study is based on the fourth national survey of traditional Chinese medicine resources in Inner Mongolia, regarding the results of the third national survey of traditional Chinese medicine resources. The species of medicinal plant resources in the Yinshan area around 31 banners, counties and districts were counted in detail. Then, using exploratory spatial data analysis(ESDA), trend surface analysis, spatial autocorrelation, geographical detector and other geostatistical analysis methods to analyze the differences in the spatial distribution of medicinal plant resources of the Yinshan area in Inner Mongolia. After discussing and analyzing the experimental results to account for the reasons for the overall trend of change and the degree of aggregation, the author further put forward relevant constructive suggestions. The results show that the areas with the most abundant and concentrated distribution of medicinal plant resources in the Yinshan area are located in Guyang county, Shiguai District of Baotou city, Tutou right banner, and Tuoketuo county; the higher richness and concentrated distribution of medicinal plant resources is in Wulate front banner, Wulate middle banner, Wulate back banner; areas with relatively low abundance and concentrated distribution of medicinal plant resources located in Qingshan district of Baotou city, Saihan district and Yuquan district of Hohhot city; areas with the lowest abundance and concentrated distribution of medicinal plant resources are located in Xincheng district and Huimin district of Hohhot city. It can be concluded that the horizontal distribution difference of multiple ecological factors, the special wetland environment of the river, the vertical difference of elevation, the farmland and other factors have an important influence on the richness of the medicinal plant resources species.

Estimation of second season maize yield loss by the spatial variability of the soil physical-water properties / Estimativa da perda de produtividade do milho segunda safra pela variabilidade espacial das características físico-hídricas do solo

Irrigation systems are still traditionally dimensioned and managed considering that the cultivated area is homogeneous, thereby not taking into account the spatial variability of soil physical and hydraulic parameters, potentially limiting productivity. The aim of this work was to estimate the yield losses of second season maize crops when comparing the application of constant and variable complementary irrigation depths along the area, in scenarios with distinct rainfall indices, for an irrigated area in the state of Mato Grosso, Brazil. Data of the soil parameters bulk density (b) and available water capacity (AWC) were analysed and maps of spatial variability were generated using geostatistical tools. In the sequence, water balance for the average values of b and AWC and individual water balances for each pixel generated in the interpolations were determined, allowing the estimation of production losses due to the application of water depths. The water demand of the second season maize was estimated with precision for the three scenarios studied. Traditional irrigation management resulted in deficit areas and excessive depths up to 54 mm for both cases, leading to a reduction in productivity of up to 12.5%.

Os sistemas de irrigação ainda são tradicionalmente dimensionados e manejados considerando que a área cultivada seja homogênea, não se levando em conta a variabilidade espacial dos parâmetros físico-hídricos do solo, podendo ser esta um fator limitante à produtividade. Assim, este trabalho teve por objetivo estimar as perdas de produtividade da cultura do milho "safrinha" ao comparar a aplicação de lâminas complementares constantes e variáveis ao longo da área, em cenários com índices de precipitação pluvial distintos, para uma área irrigada no estado do Mato Grosso. Dados dos parâmetros densidade do solo (s) e capacidade de água disponível (CAD) foram analisados, e mapas de variabilidade espacial foram gerados por meio de ferramentas de geoestatística. Em sequência, realizou-se o balanço hídrico para os valores médios de s e CAD, e balanços hídricos individuais para cada pixel gerado nas interpolações, permitindo estimar as perdas de produção por conta da aplicação de lâminas deficitárias. A demanda hídrica da cultura do milho "safrinha" foi estimada com precisão para os três cenários estudados. O manejo da irrigação tradicional proporcionou a aplicação de lâminas deficitárias e excessivas em até 54 mm para os dois casos, o que acarretou em reduções de produtividade de até 12,5%.

Spatial differences of Chinese material medicine resources species in Jilin province / 中国中药杂志

The differences in the spatial distribution of regional Chinese material medicine resources between regions are determined by differences in natural conditions and social resources among different regions. Spatiotemporal evolution of the distribution of Chinese material medicine resources is a manifestation of the development process of Chinese medicine industry in time and space. The spatiotemporal evolution of the distribution of regional Chinese material medicine resources can reveal the regularity of spatial distribution of Chinese material medicine resources. County as the basic unit of the national material medicine resources census, the difference of resource endowment is of great significance to the rational development of Chinese material medicine resources policy and the coordinated development of regional resources and environment. Based on the results of the pilot project of Jilin province, this study selected 51 counties that had completed the census of Chinese material medicine resources. According to the species of Chinese material medicine resources, we explored the diversity of Chinese material medicine resources in Jilin province by using statistical data analysis (ESDA), trend surface analysis and spatial variability function to analyze the spatial differences of Chinese material medicine resources. Chinese material medicine resources are distributed in the eastern and southeastern part of Jilin province, mostly in the Changbai Mountains. The species of Chinese material medicine resources tend to be low-value spatial aggregation; the overall cold spots are located in Changchun and Jilin city, near the administrative center, mostly urban built-up area. The rich areas of Chinese material medicine resources are rich in hot spots, mainly in broad-leaved forest. The low-abundance of Chinese material medicine resources is dominated by cultivated vegetation.

Probability of occurrence of the Brazilian spotted fever in northeast of Paraná state, Brazil / Probabilidade de ocorrência de febre maculosa brasileira no norte pioneiro do estado do Paraná, Brasil

Abstract Brazilian spotted fever (BSF) is a fatal zoonosis because of the difficulties in its early diagnosis and treatment. Occurrences of BSF in the northeast of the state of Paraná prompted investigation of areas at risk of this rickettsiosis in the municipalities of Japira, Jaboti, Pinhalão and Tomazina. To determine the areas at risk, 592 serum samples from dogs and 230 from equids were analyzed by means of the indirect immunofluorescence assay (IFA) for Rickettsia rickettsii and R. parkeri . In addition, risk probability maps were drawn up using the kriging indicator technique. Among the samples tested, 5.3% (43/822) indicated presence of antibodies reactive to at least one of the two Rickettsia species tested: 7.8% of the equids (18/230) and 4.2% of the dogs (25/592) were positive. Geostatistical analysis showed that the average seropositivity rate was 5 to 6%. Although the average seropositivity rates observed among these dogs and equids were lower than those reported from endemic areas of Brazil, the biotic components (etiological agent, vector and reservoirs) and environmental aspects of BSF epidemiology were present in these municipalities.

Resumo A febre maculosa brasileira (FMB) é uma zoonose fatal devido às dificuldades para diagnosticá-la e tratá-la precocemente. A ocorrência de casos de FMB no Estado do Paraná suscitou a investigação de áreas de risco desta rickettsiose nos municípios de Japira, Jaboti, Pinhalão e Tomazina, na mesorregião norte pioneiro do Paraná. Para determinar as áreas de risco foram analisadas amostras de soro de 592 cães e 230 equídeos submetidos à reação de imunofluorescência indireta para Rickettsia rickettsii e R. parkeri. Além disto, foram construídos mapas de probabilidade de risco pela técnica de krigagem indicatriz. Das amostras testadas 5,3% (43/822) continham anticorpos para pelo menos uma das duas rickettsias testadas. Os equídeos apresentaram uma positividade de 7,8% (18/230) e os cães de 4,2% (25/592). A análise geoestatística mostrou que a soropositividade média é de 5 a 6%. Embora as soropositividade médias de cães e equídeos constatadas tenham sido menores do que as relatadas em áreas endêmicas do território brasileiro, os componentes bióticos (agente etiológico, vetor e reservatórios) e ambientais da epidemiologia da FMB se fazem presentes nos municípios referidos.

Spatial assessment of soil contamination by heavy metals from informal electronic waste recycling in Agbogbloshie, Ghana

OBJECTIVES: This study examined the spatial distribution and the extent of soil contamination by heavy metals resulting from primitive, unconventional informal electronic waste recycling in the Agbogbloshie e-waste processing site (AEPS) in Ghana. METHODS: A total of 132 samples were collected at 100 m intervals, with a handheld global position system used in taking the location data of the soil sample points. Observing all procedural and quality assurance measures, the samples were analyzed for barium (Ba), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn), using X-ray fluorescence. Using environmental risk indices of contamination factor and degree of contamination (Cdeg), we analyzed the individual contribution of each heavy metal contamination and the overall Cdeg. We further used geostatistical techniques of spatial autocorrelation and variability to examine spatial distribution and extent of heavy metal contamination. RESULTS: Results from soil analysis showed that heavy metal concentrations were significantly higher than the Canadian Environmental Protection Agency and Dutch environmental standards. In an increasing order, Pb>Cd>Hg>Cu>Zn>Cr>Co>Ba>Ni contributed significantly to the overall Cdeg. Contamination was highest in the main working areas of burning and dismantling sites, indicating the influence of recycling activities. Geostatistical analysis also revealed that heavy metal contamination spreads beyond the main working areas to residential, recreational, farming, and commercial areas. CONCLUSIONS: Our results show that the studied heavy metals are ubiquitous within AEPS and the significantly high concentration of these metals reflect the contamination factor and Cdeg, indicating soil contamination in AEPS with the nine heavy metals studied.

Eficiência de malhas amostrais utilizadas na caracterização da variabilidade espacial de fósforo e potássio / Efficiency of sampling grids used in the characterization of phosphorus and potassium

O objetivo do trabalho foi estudar a eficiência das malhas amostrais, utilizadas nas áreas manejadas com agricultura de precisão, para a caracterização da variabilidade espacial dos teores de fósforo (P) e potássio (K). O estudo foi conduzido em 30 áreas agrícolas, localizadas no Rio Grande do Sul, cujos solos foram classificados como Latossolos Vermelhos. As dimensões das malhas amostrais estudadas foram: 100x100m (10 áreas), 142x142m (10 áreas) e 173x173m (10 áreas). Foram analisados os teores de P e K na profundidade de 0,00-0,10m. Os dados foram submetidos à análise estatística descritiva e a análise geoestatística. De modo geral, as áreas estudadas apresentaram teores médios de P e K adequados ao desenvolvimento das culturas. Entretanto, observaram-se locais com baixos teores de P, justificando fertilizações em sítio-específico. Com base em parâmetros geoestatísticos, as dimensões de malhas amostrais utilizadas são eficientes em captar as diferentes escalas da variabilidade espacial de P e K, porém, recomenda-se o uso de malhas amostrais menores, que considerem a variabilidade espacial a curtas distâncias.

The objective of the research was to evaluate the efficiency of the sampling grids, used in areas managed with precision agriculture, for the characterization of spatial variability levels of phosphorus (P) and potassium (K). The study was conducted in 30 agricultural areas, located in Rio Grande do Sul state, presenting soils classified as Oxisols. The sizes of the sampling grids studied were: 100x100m (10 areas), 142x142m (10 areas) and 173x173m (10 areas).Were analyzed the levels of P and K, in depth of sampling from 0.00-0.10m. The data were subjected to descriptive statistical analysis and geostatistical analysis. In, general, the areas showed average levels of P and K suitable for crops development. However, were observed subareas with low levels of P, justifying fertilization on site-specific. Based on geostatistical parameters, sizes of the sampling grids used are efficient to capture the different scales of spatial variability of P and K, however, it is indicated smaller sampling grids to consider the spatial variability over short distances.

Produtividade da cana-de-açúcar: variabilidade linear e espacial entre componentes tecnológicos e da produção / Productivity of cane sugar: linear and spatial variability between components and technological production

Na atualidade, a cultura da cana-de-açúcar desempenha frente à realidade brasileira, sobretudo no aspecto relacionado às fontes energéticas alternativas, importantíssimo papel. No ano de 2009, no município de Suzanápolis (SP), no Cerrado Brasileiro, foi instalado um experimento com a cultura da cana-de-açúcar em um Argissolo Vermelho eutrófico, com o objetivo de selecionar, por meio de coeficientes de correlação de Pearson, da modelagem de regressões lineares simples e de múltiplas e da correlação espacial, os melhores componentes tecnológicos e os de produção, para explicar a variabilidade da produtividade da cana-de-açúcar. Foi instalada a malha geoestatística, para a coleta de dados, com 120 pontos amostrais, numa área de 14,53 ha. Para as regressões lineares simples, a população de plantas é o componente da produção que apresenta a melhor correlação quadrática com a produtividade da cana-de-açúcar, dada por: PRO = -0,553**xPOP2+16,14*xPOP-15,77. Entretanto, para as regressões lineares múltiplas, a equação PRO = - 21,11+4,92xPOP**+0,76xPUR** é a que melhor se apresenta para estimar a referida produtividade. Espacialmente, a melhor correlação com a produtividade da cana-de-açúcar é determinada, também, pelo componente da produção da população de plantas.

Nowadays, the culture of the sugarcane plays an important role regarding the Brazilian reality, especially in the aspect related to the alternative energy sources. In 2009, the municipality of Suzanápolis (SP), in the Brazilian Cerrado, an experiment was conducted with the culture of the sugarcane in a Red eutrophic, with the aim of selecting, using Pearson correlation coefficients, modeling, simple, linear and multiple regressions and spatial correlation, and also the best technological and productive components, to explain the variability of the productivity of the sugarcane. The geostatistical grid was installed in order to collect the data, with 120 sampling points, in an area of 14.53 ha. For the simple linear regressions, the plants population is the component of production that presents the best quadratic correlation with the productivity of the sugarcane, given by: PRO = -0.553**xPOP2+16.14*xPOP-15.77. However, for multiple linear regressions, the equation PRO = -21.11+4.92xPOP**+0.76xPUR** is the one that best presents in order to estimate that productivity. Spatially, the best correlation with yield of the sugarcane is also determined by the component of the production population of plants.

A geoprocessing approach for studying and controlling schistosomiasis in the state of Minas Gerais, Brazil

Geographical information systems (GIS) are tools that have been recently tested for improving our understanding of the spatial distribution of disease. The objective of this paper was to further develop the GIS technology to model and control schistosomiasis using environmental, social, biological and remote-sensing variables. A final regression model (R² = 0.39) was established, after a variable selection phase, with a set of spatial variables including the presence or absence of Biomphalaria glabrata, winter enhanced vegetation index, summer minimum temperature and percentage of houses with water coming from a spring or well. A regional model was also developed by splitting the state of Minas Gerais (MG) into four regions and establishing a linear regression model for each of the four regions: 1 (R² = 0.97), 2 (R² = 0.60), 3 (R² = 0.63) and 4 (R² = 0.76). Based on these models, a schistosomiasis risk map was built for MG. In this paper, geostatistics was also used to make inferences about the presence of Biomphalaria spp. The result was a map of species and risk areas. The obtained risk map permits the association of uncertainties, which can be used to qualify the inferences and it can be thought of as an auxiliary tool for public health strategies.

Variabilidade espacial de atributos físicos do solo em uma microbacia hidrográfica / Spatial variability of soil physical atribbutes in small watershed

A variabilidade espacial dos atributos físicos do solo é importante para a caracterização do comportamento espacial dos solos em bacias hidrográficas. Objetivou-se com este trabalho estudar a variabilidade espacial de atributos físicos do solo em uma microbacia hidrográfica, visando subsidiar estudos de manejo do solo e da água. A área em estudo é uma microbacia que pode ser considerada homogênea para estudos com agentes erosivos, como a precipitação, devido ao tamanho reduzido (1,23 ha), mas de grande variabilidade de respostas à erosão, em função dos atributos do solo, vegetação, histórico de uso e relevo. Com o auxílio de SIG, DGPS e estação total, toda área foi dividida em grid retangular de 20 m, onde o solo foi amostrado em duas camadas, 0 a 20 cm e 20 a 40 cm. Os atributos avaliados foram: teores de areia, silte e argila e argila dispersa em água (ADA). Os resultados foram analisados utilizando-se a estatística básica, como histogramas e assimetria, e geoestatística, por meio de semivariogramas e mapas de krigagem. Houve dependência espacial de todos os atributos analisados, especialmente na camada de 20 a 40 cm.

The spatial variability of physical attributes in the soil is of great importance for soil and water management practices. This work aimed at to study the spatial variability of soil physical attributes in a small watershed, in order to evaluate the management of soil and water. The watershed area is considered homogenious, based on erosive agents, such as rainfall, due to its small area (1,23 ha), and it shows variability of soil properties, concerning vegetation, land use, and topography. GIS, DGPS and total station were used to set up a grid of 20x20 m. Soil were sampled from 0 to 20 cm and 20 to 40 cm layers. Amount of sandy, silt, clay and water dispersible clay were evaluated. The data were compared in histograms, coefficient of simetry, and geostatistical analyses expressed by semivariograms and kriging maps. All soil attributes demonstrated a spatial dependence, specially at 20-40 cm layer.