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Satellite data (MODIS, GOME, and MOPITT) together with a chemical transport global model of the atmosphere (MOZART-2) are used to characterize air pollution in Eastern China and the Eastern US to assess the differences between the...
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Satellite data (MODIS, GOME, and MOPITT) together with a chemical transport global model of the atmosphere (MOZART-2) are used to characterize air pollution in Eastern China and the Eastern US to assess the differences between the photochemical conditions in these two regions. Observations show that aerosol concentrations (both fine (radius < 0.5 μm) and coarse modes (radius > 0.5 μm)) are higher in Eastern China than in the Eastern US. The NO_x concentrations in both regions are substantially higher than in remote regions such as over the oceans (150 compared to 5 (10~(14)#cm~(-2)) over the Pacific Ocean). The CO concentrations are high in both urbanized areas (30 compared to 10 (10~(17)#cm~(-2)) over the Pacific Ocean). However, the concentrations of non-methane hydrocarbons from both anthropogenic and biogenic sources are considerably lower in Eastern China than in the Eastern US. As a result, the rate of photochemical ozone production and ozone concentrations during summer is significantly lower in Eastern China (daily averaged concentrations of 40-50 ppbv in summer) than in the Eastern US (daily averaged values of 60-70 ppbv). The analysis also shows that in Eastern China, the O_3 production is mainly due to the oxidation of carbon monoxide (54% of total O_3 production), while, in the Eastern US, the O_3 production is attributed primarily to the oxidation of reactive hydrocarbons (68% of total O_3 production). The results also indicate that biogenic emissions of hydrocarbons contribute substantially to the production of O_3 in the Eastern US. The O_3 production due to the oxidation of biogenic hydrocarbons represents approximately one third of total O_3 photochemical production in this region. Measurements of surface ozone in the Eastern US and Eastern China seem to support that the summer ozone production is lower in Eastern China than in the Eastern US. However, additional surface measurements, especially of reactive hydrocarbons and ozone are needed in Eastern China in order to improve the present analysis and to confirm our current conclusions. A sensitivity study shows that with increase in anthropogenic emissions of HCs, the surface ozone concentrations significantly increase in Eastern China, indicating that the increase in the emissions of HCs plays an important role for the enhancement in surface ozone in this region.
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To accurately determine the space use of animals, we need to follow animal movements over prolonged periods, which is especially challenging for the critically endangered Grauer's gorillas (Gorilla beringei graueri) in eastern Dem...
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To accurately determine the space use of animals, we need to follow animal movements over prolonged periods, which is especially challenging for the critically endangered Grauer's gorillas (Gorilla beringei graueri) in eastern Democratic Republic of the Congo (DRC). As a consequence, we know little about Grauer's gorillas, particularly from the lower elevational parts of their range. Between 2016 and 2018, we tracked unhabituated Grauer's gorillas in lowland forests (500-1,000 m a.s.l.), at the community-managed Nkuba Conservation Area in Nord Kivu (DRC) to provide estimates of daily travel distances (DTD), daily displacement distances (DDD), and the linearity of recorded paths expressed as the Linearity Index (LI): DDD/DTD. We found an average DTD of similar to 1.3 km (range 0.05-5.0 km), with temporal variation among monthly averages; specifically, an increase in travel distance over the June-August dry season resulting in peak travel distances at the beginning of the September-December wet season. Daily displacements showed similar temporal variation, which resulted in a lack of obvious temporal patterns in LI. We conclude that the movement patterns of Grauer's gorillas in lowland forests, which are characterized by larger DTD than those of Grauer's gorillas that inhabit highland habitats, show similarity to travel distances of other predominantly frugivorous gorillas. Moreover, the observed temporal patterns in space use may be tentatively linked to temporal changes in fruit availability or consumption. These observations have consequences for our understanding of the ecological role that Grauer's gorillas play and provide baseline data to estimate current and future distributions, abundances, and carrying capacities of this highly threatened animal.
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Land-use changes or plant species have a profound impact on soil chemical properties, but under their combined action, little is known about the changes in soil fungal communities and functional guilds. We investigated the effects...
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Land-use changes or plant species have a profound impact on soil chemical properties, but under their combined action, little is known about the changes in soil fungal communities and functional guilds. We investigated the effects of different land-use types and plant species on the fungal community and functional guilds in the eastern mountainous area of Liaoning Province, including natural secondary forests (Quercus mongolica, shrub wood), plantation forests (Larix gmelini, Pinus koraiensis), and farmland (Zea mays). Fungal community diversity and composition were analyzed using Illumina Miseq high-throughput sequencing. Responses of soil fungal communities to environmental factors were assessed through canonical correlation analysis (CCA) and Pearson correlation analysis. The results illustrated that LG, and PK did not improve soil conditions to the same degree as QM. In addition, compared to SW, ZM decreased soil fertility. The dominant phyla were Ascomycota and Basidiomycota, with average relative abundances of 55.3% and 31.78%, respectively. The phylum Ascomycota was the dominant group in QM, SW, and ZM, while, Basidiomycota dominated in LG, and PK. Heatmap (P<0.05) and NMDS (stress = 0.07) plots showed that soil fungal communities from LG, PK, and ZM tended to be separated from those of QM and SW. Additionally, soil fungal community functions from QM, SW, and LG were separated from those of PK and ZM. Both analyses demonstrated that different land-use types and plant species had significantly different impacts on the soil fungal communities. Canonical correlation analysis suggested that soil pH value, NH4+-N, and NO3--N contents were the main factors affecting the soil fungal community diversity and composition. Our results demonstrated that fungal community diversity, composition, and functional groups significantly differed among the three different land use types, so were differences in different plant species under the same land-use type.
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Statistical models for the seasonal prediction of hurricane strikes on the Eastern Seaboard of the United States (ESUS) are developed with the application of the statistical software (SAS) generalized linear model (GENMOD) to perf...
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Statistical models for the seasonal prediction of hurricane strikes on the Eastern Seaboard of the United States (ESUS) are developed with the application of the statistical software (SAS) generalized linear model (GENMOD) to perform a Poisson regression linked by a logarithmic function. Preseason climatic/oceanic signals of the El Nino South Oscillation (ENSO), the Atlantic Meridional Mode (AMM), the Atlantic Multi-decadal Oscillation (AMO), Sahel rainfall (20 degrees-10 degrees N, 20 degrees W-10 degrees E) and the North Atlantic sea surface temperature (SST) across a selected domain, all of which are closely associated with the dominant principal components of the North Atlantic Hurricane Track Density Function (HTDF), are applied as predictors. While using the Poisson regression without dividing the season into differing levels of activity types greatly degrades the model, classification of season types [based on accumulated cyclone energy (ACE)] before using the Poisson regression, can significantly improve the model performance. With this proposed new methodology, landfall counts in hyperactive and above-normal season type years can be predicted with 56.01 and 71.36% skill improvements respectively, compared with merely using climatology.
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Introduction: Recurrence patterns after curative intent gastrectomy for T1-2N0 gastric adenocarcinoma are poorly defined. We sought to assess timing, patterns, and risk factors for recurrence in patients treated at two high-volume...
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Introduction: Recurrence patterns after curative intent gastrectomy for T1-2N0 gastric adenocarcinoma are poorly defined. We sought to assess timing, patterns, and risk factors for recurrence in patients treated at two high-volume gastric cancer centers in the United States and China.
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Soil hydrological properties and aggregate stability are strongly impacted by erosion and management practices. However, magnitudes of the erosion-induced changes in topsoil depth and the attendant alterations in soil properties a...
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Soil hydrological properties and aggregate stability are strongly impacted by erosion and management practices. However, magnitudes of the erosion-induced changes in topsoil depth and the attendant alterations in soil properties are not well understood. Therefore, the present study was conducted on a long term (20 years) simulated study of topsoil depth and use of soil amendments to monitor changes in soil hydrological properties, and aggregate stability of an Alfisol at the Waterman Farm of The Ohio State University, Columbus, Ohio. The aim of the study was to compare long-term effects of soil amendments (synthetic fertilizer and organic compost) on soil physical and hydrological properties at varying soil depth. The experimental plots, comprising of five treatments, were laid out in Randomized Block Design and replicated thrice. Treatments were: (1) topsoil removed (20 cm deep), (2) undisturbed topsoil (intact topsoil); with two soil amendments: (a) synthetic fertilizer 150 kg nitrogen (N) ha(-1) yr(-1), (b) organic compost at 20 Mg ha(-1) yr(-1), and (3) a permanent grass field (as a benchmark plot). Soil properties, measured for 0-10 cm and 10-20 cm depth, were: texture, aggregate stability, geometric mean diameter (GMD) of aggregates, water retention properties, hydraulic conductivity (Ks), pore size distribution, and plant available water capacity (PAWC). Aggregate stability was the highest (87.9 and 84.7%) in the permanent grass at 0-10 cm and 10-20 cm depths, respectively. Among the cultivated treatments, compost-amended undisturbed plots (87.6 and 86.9%) had the highest proportion of water stable aggregates (WSA) at 0-10 cm and 10-20 cm depths, respectively. However, the GMD of aggregates was the highest 4.1 mm (0-10 cm) and 3.5 mm (10-20 cm) for the topsoil removed and compost-amended treatment. Soil texture was silty clay loam in topsoil removed treatments, clay loam in the undisturbed treatment, and loam in permanent grass treatment, probably due to artificial removal of topsoil. Plant available water content was more in the disturbed and undisturbed compost-amended plots for both the 0-10 and 10-20 cm depths, respectively. The highest soil water volumetric content ranged from 0.37 to 0.25 m(3) m(-3) in the topsoil removed fertilizer added compared with 0.34 to 0.24 m(3) m(-3) in undisturbed compost added plots, respectively. However, the pore size distribution was not affected by treatments at the 0-10 cm depth. For the10-20 cm depth, an overall greater pore size distribution range of 0.04 to 0.33 m(3) m(-3) was observed in the permanent grass, and undisturbed compost amended treatments. Soil Ks (cm day(-1)) for 0-10 cm depth did not differ significantly across treatments. The data obtained enhances the understanding of the impacts of long-term use of amendments on soil water retention and aggregate stability of simulated topsoil removed and undisturbed field under no-till (NT) in corn (Zea mays)-soybean (Glycine max L Merr.) rotation in the Eastern Corn Belt of the U.S.
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Habitat loss threatens large mammals worldwide, and their survival will depend on habitat in human-dominated landscapes. Conservation planners thus face the challenge to identify areas of least conflict with land use, yet broadsca...
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Habitat loss threatens large mammals worldwide, and their survival will depend on habitat in human-dominated landscapes. Conservation planners thus face the challenge to identify areas of least conflict with land use, yet broadscale species distribution models rarely incorporate real landscape patterns nor do they identify potential conservation conflicts. An excellent example of such conservation challenges is provided by European bison (Bison bonasus). Almost extinct by the early 20th century, bison can only survive in the wild if large metapopulations are established, but it is unclear where new herds can be reintroduced. Using European bison as an example we conducted a continental-scale habitat assessment based on real landscape patterns. Our specific aims here were to (1) map European bison habitat throughout the species' former range, (2) examine whether broadscale habitat suitability factors differ from previously reported fine-scale factors, and (3) assess where suitable habitat occurs in areas with low potential for conflict with land use. We assessed habitat suitability using herd range maps for all 36 free-ranging European bison herds as habitat use data. Habitat suitability maps were compared with maps of land cover, livestock density, agricultural constraints, and protected areas to assess potential conservation conflicts. Our models had high goodness of fit (AUC 1/4 0.941), and we found abundant potential bison habitat. European bison prefer mosaic-type landscapes, with a preference for broad-leaved and mixed forests. European bison metapopulations do not appear to be limited by habitat availability. However, most potential habitat occurred outside protected areas and has substantial potential for conservation conflicts. The most promising areas for establishing large bison metapopulations all occur in Eastern Europe (i.e., the Carpathians, the Belarus- Ukraine borderlands, and several regions in European Russia). The future of European bison and that of other large mammals in the wild thus clearly lies in Eastern Europe, because habitat there is most abundant and least fragmented, and because the potential for conflict with land use is lower. More generally we suggest that broadscale habitat assessments that incorporate land use can be powerful tools for conservation planning and will be key if large herbivore and carnivore conservation is to succeed in a human-dominated world.
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Agriculture is expanding and intensifying in many areas of the world, but abandoned agriculture is also becoming more widespread. Unfortunately, data and methods to monitor abandoned agriculture accurately over large areas are lac...
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Agriculture is expanding and intensifying in many areas of the world, but abandoned agriculture is also becoming more widespread. Unfortunately, data and methods to monitor abandoned agriculture accurately over large areas are lacking. Remote sensing methods may be able to fill this gap though, especially with the frequent observations provided by coarser-resolution sensors and new classification techniques. Past efforts to map abandoned agriculture relied mainly on Landsat data, making it hard to map large regions, and precluding the use of phenology information to identify abandoned agriculture. Our objective here was to test methods to map abandoned agriculture at broad scales with coarse-resolution satellite imagery and phenology data. We classified abandoned agriculture for one Moderate Resolution Imaging Spectroradiometer (MODIS) tile in Eastern Europe (~1,236,000km ~2) where abandoned agriculture was widespread. Input data included Normalized Difference Vegetation Index (NDVI) and reflectance bands (NASA Global MODIS Terra and Aqua 16-Day Vegetation Indices for the years 2003 through 2008, ~250-m resolution), as well as phenology metrics calculated with TIMESAT. The data were classified with Support Vector Machines (SVM). Training data were derived from several Landsat classifications of agricultural abandonment in the study area. A validation was conducted based on independently collected data. Our results showed that it is possible to map abandoned agriculture for large areas from MODIS data with an overall classification accuracy of 65%. Abandoned agriculture was widespread in our study area (15.1% of the total area, compared to 29.6% agriculture). We found strong differences in the MODIS data quality for different years, with data from 2005 resulting in the highest classification accuracy for the abandoned agriculture class (42.8% producer's accuracy). Classifications of MODIS NDVI data were almost as accurate as classifications based on a combination of both red and near-infrared reflectance data. MODIS NDVI data only from the growing-season resulted in similar classification accuracy as data for the full year. Using multiple years of MODIS data did not increase classification accuracy. Six phenology metrics derived with TIMESAT from the NDVI time series (2003-2008) alone were insufficient to detect abandoned agriculture, but phenology metrics improved classification accuracies when used in conjunction with NDVI time series by more than 8% over the use of NDVI data alone. The approach that we identified here is promising and suggests that it is possible to map abandoned agriculture at broad scales, which is relevant to gain a better understanding of this important land use change process.
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Maize lethal necrosis (MLN) disease is a major constraint on maize production in Eastern Africa since its first report in 2012 in Kenya. The main causative agent is maize chlorotic mottle virus (MCMV) which co-infects maize with o...
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Maize lethal necrosis (MLN) disease is a major constraint on maize production in Eastern Africa since its first report in 2012 in Kenya. The main causative agent is maize chlorotic mottle virus (MCMV) which co-infects maize with other viruses from the family Potyviridae. In Africa, Sugarcane mosaic virus (SCMV) is the most common potyvirus that co-infects maize synergistically with MCMV. MCMV can be transmitted by insect vectors, mechanically and via contaminated seeds. Monitoring of MCMV is important in farmers’ fields, seed fields, seed-lots and in grain. Robust diagnostic tools are essential in epidemiological studies, germplasm screening and exchange of disease-free materials across the regions and globally. Therefore, a sensitive, reliable and affordable diagnostic tool for MCMV is necessary in the laboratory and also in the field. A reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay with two-end point analysis was developed to detect MCMV in active vegetative stages and in seed. Six sets of specific primers were designed and evaluated. Amplification was detected in 60 min using the SYBR green colour change and in 10 to 20 min for real-time amplification in the Genie II platform. The assay discriminated the common viruses infecting maize in Eastern Africa. The assay showed excellent specificity to MCMV. The simplicity, rapidity, and inexpensiveness of this technique make it a suitable choice for large-scale sample processing, especially by laboratories with limited resources and for field analysis performed by regulatory agencies in the region.?Key word: Maize lethal necrosis, maize chlorotic mottle virus, diagnostics, loop mediated isothermal amplification.
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