Hyperspectral imaging for small-scale analysis of symptoms caused by different sugar beet diseases

Hyperspectral imaging (HSI) offers high potential as a non-invasive diagnostic tool for disease detection. In this paper leaf characteristics and spectral reflectance of sugar beet leaves diseased with Cercospora leaf spot, powdery mildew and leaf rust at different development stages were connected. Light microscopy was used to describe the morphological changes in the host tissue due to pathogen colonisation. Under controlled conditions a hyperspectral imaging line scanning spectrometer (ImSpector V10E) with a spectral resolution of 2.8 nm from 400 to 1000 nm and a spatial resolution of 0.19 mm was used for continuous screening and monitoring of disease symptoms during pathogenesis. A pixel-wise mapping of spectral reflectance in the visible and near-infrared range enabled the detection and detailed description of diseased tissue on the leaf level. Leaf structure was linked to leaf spectral reflectance patterns. Depending on the interaction with the host tissue, the pathogens caused disease-specific spectral signatures. The influence of the pathogens on leaf reflectance was a function of the developmental stage of the disease and of the subarea of the symptoms. Spectral reflectance in combination with Spectral Angle Mapper classification allowed for the differentiation of mature symptoms into zones displaying all ontogenetic stages from young to mature symptoms. Due to a pixel-wise extraction of pure spectral signatures a better understanding of changes in leaf reflectance caused by plant diseases was achieved using HSI. This technology considerably improves the sensitivity and specificity of hyperspectrometry in proximal sensing of plant diseases

Measuring the Impact of Walking Environments on Brain Activation: Results from an fNIRS Pilot Study

Studying the impact of built urban environments on pedestrians' walking experience can improve our understanding of the environmental factors that influence perceived walkability. This can contribute to the design of pleasant urban environments that promote better health and well-being for city residents. However, evidence-based research on perceptions of walkability is still limited. Research has demonstrated that functional near-infrared spectroscopy (fNIRS), an optical brain imaging technique, can measure cortical neural activation. Some studies have employed fNIRS to investigate brain activation by contrasting built and natural environments; however, little research has used fNIRS to investigate the effect of built urban environments on brain activity. Therefore, the aim of this study was to apply fNIRS to measure the effect of different built urban environments on prefrontal cortex activation. The present article presents preliminary results from a pilot study involving five participants (one female, age 31.4 ± 5.1 years). While we measured their prefrontal cortex (PFC) oxyhemoglobin (HbO) and deoxyhemoglobin (HbR), participants watched nine 20-second videos of urban environments from a pedestrian's perspective in a laboratory setting. Viewing pleasant walking environments led to a significant decrease in HbO concentrations in the right and central regions of the PFC, indicating physiological relaxation. This study demonstrates the feasibility of using fNIRS to study the built environment and opens up promising opportunities to explore the relationship between urban environments and pedestrians' experiences

New live screening of plant-nematode interactions in the rhizosphere

Abstract Free living nematodes (FLN) are microscopic worms found in all soils. While many FLN species are beneficial to crops, some species cause significant damage by feeding on roots and vectoring viruses. With the planned legislative removal of traditionally used chemical treatments, identification of new ways to manage FLN populations has become a high priority. For this, more powerful screening systems are required to rapidly assess threats to crops and identify treatments efficiently. Here, we have developed new live assays for testing nematode responses to treatment by combining transparent soil microcosms, a new light sheet imaging technique termed Biospeckle Selective Plane Illumination Microscopy (BSPIM) for fast nematode detection, and Confocal Laser Scanning Microscopy for high resolution imaging. We show that BSPIM increased signal to noise ratios by up to 60 fold and allowed the automatic detection of FLN in transparent soil samples of 1.5 mL. Growing plant root systems were rapidly scanned for nematode abundance and activity, and FLN feeding behaviour and responses to chemical compounds observed in soil-like conditions. This approach could be used for direct monitoring of FLN activity either to develop new compounds that target economically damaging herbivorous nematodes or ensuring that beneficial species are not negatively impacted

Pedestrian Access to Public Transport

PhD thesis in Risk management and societal safetyAsplan Via

Stimulating Urban Walking Environments – Can we Measure the Effect?

Walking is an outdoor mobility. Understanding how urban environments influence the experience of walking enables walking to be supported through urban planning and design. This research demonstrates that the effect of a stimulating walking environment is a measurable factor. Psychological knowledge provides a background for quantifying the amount of visual stimulus that pedestrians receive unconsciously from the surrounding environment. While walking, people capture the visual environment through frequent head movements. By looking downwards to the walking surface, pedestrians turn away from what surrounds them. Socially active urban squares and pedestrian streets are highly stimulating. Head movements increase by 71% and looking down decreases by 54%, compared to environments designed for cars. Underpasses are the least stimulating. Head movements drop by 64% and time looked down increases by 164% in an underpass, compared to the busiest urban square in the study. A second analysis introduces a method to quantitatively represent the visual walking environment. Two multiple linear regression statistics uncover the environmental features that attract pedestrians’ visual attention. If not crossing streets, pedestrians do not look at cars; they look at other people, non-monotonous facades and green features. Shop windows receive prolonged viewings, to inspect what is going on behind transparent facades. Narrower streets are more stimulating, as more details are closer to the eyes. The distance at which human sense organs can collect sensory information from the environment is limited. Walking environments that do not fit with this human scale are less stimulating