178 research outputs found

    Bean Leaf Beetle Biology and Management

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    In the past few years, Iowa bean leaf beetle densities have reached record levels. Bean leaf beetles are present in Iowa soybean fields every year, but recently many producers have had to apply insecticides to manage this pest

    Site-specific soybean insect management: benefits and barriers

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    Insect pest management involves monitoring pests and treating with an insecticide when economic thresholds are exceeded. Site-specific insect management offers the opportunity to treat only those areas where pest populations are highest. For 3 years, entomologists at Iowa State University have been involved in a site-specific farming project, funded by the Iowa Soybean Promotion Board, to study the potential of this technology for soybean insect management. Some potential benefits and current barriers to implementing site-specific soybean insect management have been identified

    Early-season bean leaf beetles rarely equal economic damage

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    Don\u27t be surprised to see more bean leaf beetles this season than in typical years. Last year, a large bean leaf beetle population was present in most of Iowa. The mild winter apparently allowed at least 50 percent winter survival of overwintering beetles. This is in contrast to the 25 percent survival recorded last year. The bean leaf beetle completes two generations each year in Iowa. Adults overwinter and emerge in late April or May depending on the temperature. Adults have been reported in 1998 since the third week of April

    New Thresholds and Strategies for Management of Bean Leaf Beetles in Iowa Soybean

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    The bean leaf beetle is an annual pest of soybean in midwestern states. Adult beetles feed on any aboveground plant part and are especially fond of soybean pods late in the growing season. Larvae, which are similar in appearance to com rootworm larvae, feed below the soil surface on soybean nodules, but their impact on yield or plant health is not known. In addition to the physical injury that bean leaf beetle adults cause to soybean plants, this insect also transmits bean pod mottle virus-a potentially yield-robbing plant disease that makes proper management of this insect even more critical. This report focuses on a new concept for managing second-generation bean leaf beetle adults, the performance of insecticides in controlling this pest, and the problems related to bean pod mottle virus and transmission by adult beetles

    Management of Bean Leaf Beetles and Bean Pod Mottle Virus: A Summary of Current and Future Research

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    In 2002, the bean leaf beetle, Cerotoma trifurcata (Forster), population reached the highest level recorded in 14 years (Fig. 1). The bean leaf beetle is now considered the most frequent insect pest of Iowa soybean, and concern over this pest is greater because it transmits a soybean virus, Bean pod mottle virus (BPMV). Bean leaf beetle management recently has become more complicated because of this insect\u27s association with BPMV, therefore, it is important to understand the life cycle of the beetle and its relation to BPMV before management decisions are made

    Trends in NMR Structural Elucidation Of Polycyclic Cages, Namely: Adamantane, Pentacycloundecane and Trishomocubane

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    Advances in Nuclear Magnetic Resonance (NMR) spectroscopy is a cornerstone in structure elucidation of polycyclic ‘cage’ scaffolds. Due to the  compactness of these compounds, much overlap, as well as unique through-space and bond NMR interactions are frequently observed. This review  serves as a guide for the NMR elucidation of future derivatives by providing some of the typical and relevant aspects of the characteristic trends,  substituent patterns and chemical shift behaviour for the identification of the polycyclic structures, namely adamantane, pentacycloundecane and trishomocubane derivatives

    Evaluating the use of 3'-(p-Aminophenyl) fluorescein for determining the formation of highly reactive oxygen species in particle suspensions

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    <p>Abstract</p> <p>Background</p> <p>Given the importance of highly reactive oxygen species (hROS) as reactants in a wide range of biological, photochemical, and environmental systems there is an interest in detection and quantification of these species. The extreme reactivity of the hROS, which includes hydroxyl radicals, presents an analytical challenge. 3'-(<it>p</it>-Aminophenyl) fluorescein (APF) is a relatively new probe used for measuring hROS. Here, we further evaluate the use of APF as a method for the detection of hydroxyl radicals in particle suspensions.</p> <p>Results</p> <p>Particle-generated hROS can be quantified with an estimated detection limit of 50 nM. Measurements of hROS in two National Institute of Standards and Technology (NIST 2709 and 2710) soil suspensions and a pyrite suspension show non-linear particle dose-response curves for hROS generation. APF can also be used in solutions containing no dissolved molecular oxygen (O<sub>2</sub>) to determine the role of O<sub>2 </sub>in the formation of hROS. Results confirm that O<sub>2 </sub>is mechanistically important in the formation of hROS by dissolved ferrous iron and in pyrite suspensions.</p> <p>Conclusion</p> <p>Given the non-linear dose-response curves for particle generation of hROS, we recommend using several particle loadings in experiments aimed to compare particles for their hROS generation potential. The method presented here is specific to hROS and simple to perform. The analysis can be conducted in mobile labs as only basic laboratory equipment is required.</p

    Identifying Unique Neighborhood Characteristics to Guide Health Planning for Stroke and Heart Attack: Fuzzy Cluster and Discriminant Analyses Approaches

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    Socioeconomic, demographic, and geographic factors are known determinants of stroke and myocardial infarction (MI) risk. Clustering of these factors in neighborhoods needs to be taken into consideration during planning, prioritization and implementation of health programs intended to reduce disparities. Given the complex and multidimensional nature of these factors, multivariate methods are needed to identify neighborhood clusters of these determinants so as to better understand the unique neighborhood profiles. This information is critical for evidence-based health planning and service provision. Therefore, this study used a robust multivariate approach to classify neighborhoods and identify their socio-demographic characteristics so as to provide information for evidence-based neighborhood health planning for stroke and MI.The study was performed in East Tennessee Appalachia, an area with one of the highest stroke and MI risks in USA. Robust principal component analysis was performed on neighborhood (census tract) socioeconomic and demographic characteristics, obtained from the US Census, to reduce the dimensionality and influence of outliers in the data. Fuzzy cluster analysis was used to classify neighborhoods into Peer Neighborhoods (PNs) based on their socioeconomic and demographic characteristics. Nearest neighbor discriminant analysis and decision trees were used to validate PNs and determine the characteristics important for discrimination. Stroke and MI mortality risks were compared across PNs. Four distinct PNs were identified and their unique characteristics and potential health needs described. The highest risk of stroke and MI mortality tended to occur in less affluent PNs located in urban areas, while the suburban most affluent PNs had the lowest risk.Implementation of this multivariate strategy provides health planners useful information to better understand and effectively plan for the unique neighborhood health needs and is important in guiding resource allocation, service provision, and policy decisions to address neighborhood health disparities and improve population health
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