1,621 research outputs found

    MAIZE YIELD ESTIMATION IN KENYA USING MODIS

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    Abstract. Monitoring staple crop production can support agricultural research, business such as crop insurance, and government policy. Obtaining accurate estimates through field work is very expensive, and estimating it through remote sensing is promising. We estimated county-level maize yield for the 37 maize producing countries in Kenya from 2010 to 2017 using Moderate Resolution Imaging Spectroradiometer (MODIS) data. Support Vector Regression (SVR) and Random Forest (RF) were used to fit models with observed county level maize yield as a function of vegetation indices. The following five MODIS vegetation indices were used: green normalized difference vegetation index, normalized difference vegetation index, normalized difference moisture index, gross primary production, and fraction of photosynthetically active radiation. The models were evaluated with 5-fold leave one year out cross-validation. For SVR, R2 was 0.70, the Root Mean Square Error (RMSE) was 0.50 MT/ha and Mean Absolute Percentage Error (MAPE) was 27.6%. On the other hand for RF these were 0.69, 0.51 MT/ha and 29.3% respectively. These results are promising and should be tested in specific applications to understand if they are good enough for use

    Geometric potential and transport in photonic topological crystals

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    We report on the experimental realization of an optical analogue of a quantum geometric potential for light wave packets constrained on thin dielectric guiding layers fabricated in silica by the femtosecond laser writing technology. We further demonstrate the optical version of a topological crystal, with the observation of Bloch oscillations and Zener tunneling of purely geometric nature

    Role of arginase 2 in systemic metabolic activity and adipose tissue fatty acid metabolism in diet-induced obese mice

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    Visceral adipose tissue (VAT) inflammation and metabolic dysregulation are key components of obesity-induced metabolic disease. Upregulated arginase, a ureahydrolase enzyme with two isoforms (A1-cytosolic and A2-mitochondrial), is implicated in pathologies associated with obesity and diabetes. This study examined A2 involvement in obesity-associated metabolic and vascular disorders. WT and globally deleted A2(−/−) or A1(+/−) mice were fed either a high fat/high sucrose (HFHS) diet or normal diet (ND) for 16 weeks. Increases in body and VAT weight of HFHS-fed WT mice were abrogated in A2−/−, but not A1+/−, mice. Additionally, A2−/− HFHS-fed mice exhibited higher energy expenditure, lower blood glucose, and insulin levels compared to WT HFHS mice. VAT and adipocytes from WT HFHS fed mice showed greater A2 expression and adipocyte size and reduced expression of PGC-1α, PPAR-γ, and adiponectin. A2 deletion blunted these effects, increased levels of active AMPK-α, and upregulated genes involved in fatty acid metabolism. A2 deletion prevented HFHS-induced VAT collagen deposition and inflammation, which are involved in adipocyte metabolic dysfunction. Endothelium-dependent vasorelaxation, impaired by HFHS diet, was significantly preserved in A2−/− mice, but more prominently maintained in A1+/− mice. In summary, A2 is critically involved in HFHS-induced VAT inflammation and metabolic dysfunction

    Antigen depot is not required for alum adjuvanticity

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    Alum adjuvants have been in continuous clinical use for more than 80 yr. While the prevailing theory has been that depot formation and the associated slow release of antigen and/or inflammation are responsible for alum enhancement of antigen presentation and subsequent T- and B-cell responses, this has never been formally proven. To examine antigen persistence, we used the chimeric fluorescent protein EαGFP, which allows assessment of antigen presentation in situ, using the Y-Ae antibody. We demonstrate that alum and/or CpG adjuvants induced similar uptake of antigen, and in all cases, GFP signal did not persist beyond 24 h in draining lymph node antigen-presenting cells. Antigen presentation was first detectable on B cells within 6–12 h of antigen administration, followed by conventional dendritic cells (DCs) at 12–24 h, then finally plasmacytoid DCs at 48 h or later. Again, alum and/or CpG adjuvants did not have an effect on the magnitude or sequence of this response; furthermore, they induced similar antigen-specific T-cell activation in vivo. Notably, removal of the injection site and associated alum depot, as early as 2 h after administration, had no appreciable effect on antigen-specific T- and B-cell responses. This study clearly rules out a role for depot formation in alum adjuvant activity

    Survival and cause-specific mortality of female eastern wild turkeys in two frequently-burned longleaf pine savannas

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    Longleaf pine savannas have declined throughout the southeastern United States due to land-use change. Fortunately, natural resource professionals are currently restoring these ecologically and economically important savannas. Although efforts are underway to restore longleaf pine savannas, little information exists on female eastern wild turkey Meleagris gallopavo silvestris population dynamics in these systems. Therefore, we evaluated survival and cause-specific mortality of female eastern wild turkeys in two longleaf pine savannas in southwestern Georgia. We radio-marked 126 female wild turkeys during 2010–2013 and monitored their survival; 66 (52.4%) radio-marked females died during the study. We estimated causes of death for 37 mortality events with predation serving as the leading known cause of mortality, with 35.1% of mortalities attributed to mesocarnivore predation (e.g., bobcat Lynx rufus, coyote Canis latrans, and gray fox Urocyon cinereoargenteus) and 18.9% to great-horned owl Bubo virginianus predation. One female (2.7%) was hit by a vehicle. Seasonal survival estimates varied from a high during fall (Ŝ = 0.94; 95% CI: 0.86–1.00) to a low during spring (Ŝ = 0.76; 95% CI: 0.68–0.87). Survival of incubating females was 0.82 (95% CI: 0.71–0.93) and survival of nonincubating females was 0.67 (95% CI: 0.52–0.87). Annual survival was 0.55 (95% CI: 0.44–0.67). To ensure sustainable wild turkey populations in longleaf pine savannas, we suggest managers monitor relationships between survival and population productivity

    Survival and cause-specific mortality of female eastern wild turkeys in two frequently-burned longleaf pine savannas

    Get PDF
    Longleaf pine savannas have declined throughout the southeastern United States due to land-use change. Fortunately, natural resource professionals are currently restoring these ecologically and economically important savannas. Although efforts are underway to restore longleaf pine savannas, little information exists on female eastern wild turkey Meleagris gallopavo silvestris population dynamics in these systems. Therefore, we evaluated survival and cause-specific mortality of female eastern wild turkeys in two longleaf pine savannas in southwestern Georgia. We radio-marked 126 female wild turkeys during 2010–2013 and monitored their survival; 66 (52.4%) radio-marked females died during the study. We estimated causes of death for 37 mortality events with predation serving as the leading known cause of mortality, with 35.1% of mortalities attributed to mesocarnivore predation (e.g., bobcat Lynx rufus, coyote Canis latrans, and gray fox Urocyon cinereoargenteus) and 18.9% to great-horned owl Bubo virginianus predation. One female (2.7%) was hit by a vehicle. Seasonal survival estimates varied from a high during fall (Ŝ = 0.94; 95% CI: 0.86–1.00) to a low during spring (Ŝ = 0.76; 95% CI: 0.68–0.87). Survival of incubating females was 0.82 (95% CI: 0.71–0.93) and survival of nonincubating females was 0.67 (95% CI: 0.52–0.87). Annual survival was 0.55 (95% CI: 0.44–0.67). To ensure sustainable wild turkey populations in longleaf pine savannas, we suggest managers monitor relationships between survival and population productivity

    Evaluating Antioxidant Activity of Selected Plant Species Native to Cedarville, Ohio

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    Over the past several decades, there has been an increase in the number of synthetic drug molecules developed and utilized to treat various conditions. Although these synthetic drugs have proven useful, there has been growing public concern regarding the potentially negative long-term effects of synthetic agents on the body. As a result, there has been an increased interest in identifying and utilizing plant extracts and purified compounds since they are perceived to be a more natural alternative to synthetic drugs. The goal of this study was to evaluate the specific antioxidant properties of alsike clover Trifolum hybridum when produced under differing growing conditions. The alsike clover was collected from the campus of Cedarville University, Cedarville, Ohio for testing. Alsike clover was removed from the field in January 2013, and transplanted indoors under grow lights for 14 days. These plants were then subjected to three separate 60-day treatments: control treatment - watering to field capacity with no fertilizer; positive treatment - watering to field capacity with fertilizer; and negative treatment - half of the water given to the field capacity treatment with no fertilizer. The rationale for choosing these different treatments was to evaluate the effects of specific growing conditions on bioactive secondary metabolite production in alsike clover. The biological evaluation was accomplished by conducting diphenylpicrylhyrazyl (DPPH) free-radical scavenging and Folin Ciocalteu assays to assess the concentration of polyphenolic compounds. Results from these experiments indicate that the biological and chemical profiles of alsike clover can be influenced by the environmental conditions under which the plants are grown
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