65 research outputs found

    Investigating the Potential of a Newly Developed UAV-Mounted VNIR/SWIR Imaging System for Monitoring Crop Traits—A Case Study for Winter Wheat

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    UAV-based multispectral multi-camera systems are widely used in scientific research for non-destructive crop traits estimation to optimize agricultural management decisions. These systems typically provide data from the visible and near-infrared (VNIR) domain. However, several key absorption features related to biomass and nitrogen (N) are located in the short-wave infrared (SWIR) domain. Therefore, this study investigates a novel multi-camera system prototype that addresses this spectral gap with a sensitivity from 600 to 1700 nm by implementing dedicated bandpass filter combinations to derive application-specific vegetation indices (VIs). In this study, two VIs, GnyLi and NRI, were applied using data obtained on a single observation date at a winter wheat field experiment located in Germany. Ground truth data were destructively sampled for the entire growing season. Likewise, crop heights were derived from UAV-based RGB image data using an improved approach developed within this study. Based on these variables, regression models were derived to estimate fresh and dry biomass, crop moisture, N concentration, and N uptake. The relationships between the NIR/SWIR-based VIs and the estimated crop traits were successfully evaluated (R2: 0.57 to 0.66). Both VIs were further validated against the sampled ground truth data (R2: 0.75 to 0.84). These results indicate the imaging system’s potential for monitoring crop traits in agricultural applications, but further multitemporal validations are needed

    Investigating the Potential of a Newly Developed UAV-Mounted VNIR/SWIR Imaging System for Monitoring Crop Traits—A Case Study for Winter Wheat

    Get PDF
    UAV-based multispectral multi-camera systems are widely used in scientific research for non-destructive crop traits estimation to optimize agricultural management decisions. These systems typically provide data from the visible and near-infrared (VNIR) domain. However, several key absorption features related to biomass and nitrogen (N) are located in the short-wave infrared (SWIR) domain. Therefore, this study investigates a novel multi-camera system prototype that addresses this spectral gap with a sensitivity from 600 to 1700 nm by implementing dedicated bandpass filter combinations to derive application-specific vegetation indices (VIs). In this study, two VIs, GnyLi and NRI, were applied using data obtained on a single observation date at a winter wheat field experiment located in Germany. Ground truth data were destructively sampled for the entire growing season. Likewise, crop heights were derived from UAV-based RGB image data using an improved approach developed within this study. Based on these variables, regression models were derived to estimate fresh and dry biomass, crop moisture, N concentration, and N uptake. The relationships between the NIR/SWIR-based VIs and the estimated crop traits were successfully evaluated (R2: 0.57 to 0.66). Both VIs were further validated against the sampled ground truth data (R2: 0.75 to 0.84). These results indicate the imaging system’s potential for monitoring crop traits in agricultural applications, but further multitemporal validations are needed

    Decision-making in sustainable uban mobility planning: Common practice and future directions

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    This paper highlights the challenges for cities in selecting sustainable and cost-effective transport and mobility measures. Thereby it shall provoke thought on the implications for decision-making resulting from Sustainable Urban Mobility Plans. Firstly, an understanding of the challenges of determining a transport project’s viability will be conveyed. Secondly, the paper presents five case studies of sustainable urban mobility planning and the role of project appraisal in those policy-making processes.In discussing the challenges of traditional project-appraisal and examining actual local decision-making, the paper finds some crucial challenges in the appraisal of small-scale sustainable transport activities. It concludes by highlighting potential implications of these

    Completion of Hepatitis C Virus Replication Cycle in Heterokaryons Excludes Dominant Restrictions in Human Non-liver and Mouse Liver Cell Lines

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    Hepatitis C virus (HCV) is hepatotropic and only infects humans and chimpanzees. Consequently, an immunocompetent small animal model is lacking. The restricted tropism of HCV likely reflects specific host factor requirements. We investigated if dominant restriction factors expressed in non-liver or non-human cell lines inhibit HCV propagation thus rendering these cells non-permissive. To this end we explored if HCV completes its replication cycle in heterokaryons between human liver cell lines and non-permissive cell lines from human non-liver or mouse liver origin. Despite functional viral pattern recognition pathways and responsiveness to interferon, virus production was observed in all fused cells and was only ablated when cells were treated with exogenous interferon. These results exclude that constitutive or virus-induced expression of dominant restriction factors prevents propagation of HCV in these cell types, which has important implications for HCV tissue and species tropism. In turn, these data strongly advocate transgenic approaches of crucial human HCV cofactors to establish an immunocompetent small animal model

    Electric battery and fuel cell vehicles

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    This review of sources has assessed existing evidence for economic benefits arising from activities fostering the use of vehicles that use electricity to power an electric motor. It is designed to support cities in their decision making and measure selection process. The article is one of 22 reviews published in this volume

    Fetaler pyeloamniotischer Shunt bei Hydrops fetalis mit massiver Hydronephrose aufgrund beidseitiger Ureterabgangsstenose

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    Need for a holistic assessment of urban mobility measures : review of existing methods and design of a simplified approach

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    The lack of suitable tools to assess sustainable mobility measures' costs, benefits and overall impacts is a significant factor impeding their implementation. Cost-benefit analysis (CBA) is often applied to large-scale infrastructure projects, but does not capture all relevant socio-economic impacts. Small-scale but potentially highly cost-effective measures often do not have the critical mass to warrant a thorough cost-benefit analysis. This paper reviews existing assessment methodologies, including their advantages, limitations and application to different urban mobility measures, and current assessment practice in cities based on survey results. Based on these analyses, a holistic approach for project appraisal is proposed, consisting of aspects of a multi-criteria analysis (MCA) and CBA and applicable to a variety of urban mobility measures
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