Analysis and design of multifunctional agricultural landscapes : a graph theoretic approach

This thesis deals with the development of quantitative methodologies for the evaluation of landscape functions and their interactions in multifunctional agricultural landscapes. It focuses on the spatial coherence of hedgerow networks for ecological functions and landscape character for perception of landscape identity, and on their integration in a multifunctional and multiscale trade-off analysis. Graph theory provided the basis for new methodologies that are applied in this research

Sensorimotor anticipation of others’ actions in real-world and video settings: Modulation by level of engagement?

Electroencephalography (EEG) studies investigating social cognition have used both video and real-world stimuli, often without a strong reasoning as to why one or the other was chosen. Video stimuli can be selected for practical reasons, while naturalistic real-world stimuli are ecologically valid. The current study investigated modulatory effects on EEG mu (8–13Hz) suppression, directly prior to the onset–and during the course–of observed actions, related to real-world and video settings. Recordings were made over sensorimotor cortex and stimuli in both settings consisted of identical (un)predictable object-related grasping and placing actions. In both settings, a very similar mu suppression was found during unfolding of the action, irrespective of predictability. However, mu suppression related to the anticipation of upcoming predictable actions was found exclusively in the real-world setting. Thus, even though the presentation setting does not seem to modulate mu suppression during action observation, it does affect the anticipation-related mu suppression. We discuss the possibility that this may be due to increased social engagement in real-world settings, which in particular affects anticipation. The findings emphasize the importance of using real-world stimuli to bring out the subtle, anticipatory, aspects related to action observation

Sensorimotor representation of observed dyadic actions with varying agent involvement: an EEG mu study

Observation of others’ actions activates motor representations in sensorimotor cortex. Although action observation in the real-world often involves multiple agents displaying varying degrees of action involvement, most lab studies on action observation studied individual actions. We recorded EEG-mu suppression over sensorimotor cortex to investigate how the multi-agent nature of observed hand/arm actions is incorporated in sensorimotor action representations. Hereto we manipulated the extent of agent involvement in dyadic interactions presented in videos. In all clips two agents were present, of which agent-1 always performed the same action, while the involvement of agent-2 differed along three levels: (1) passive and uninvolved, (2) passively involved, (3) actively involved. Additionally, a no-action condition was presented. The occurrence of these four conditions was predictable thanks to cues at the start of each trial, which allowed to study possible mu anticipation effects. Dyadic interactions in which agent-2 was actively involved resulted in increased power suppression of the mu rhythm compared to dyadic interactions in which agent-2 was passively involved. The latter did not differ from actions in which agent-2 was present but not involved. No anticipation effects were found. The results suggest that the sensorimotor representation of a dyadic interaction takes into account the simultaneously performed bodily articulations of both agents, but no evidence was found for incorporation of their static articulated postures

Open data and smallholder food and nutritional security

This report was commissioned CTA as a member of the GODAN initiative. It aims to provide a better understanding of the actual impact of the open data movement on the food and nutrition security of smallholders and highlight the areas of potential unfilled opportunity

Modeling the partially coherent behavior of few-mode far-infrared grating spectrometers

Modelling ultra-low-noise far-infrared grating spectrometers has become crucial for the next generation of far-infrared space observatories. Conventional techniques are awkward to apply because of the partially coherent form of the incident spectral field, and the few-mode response of the optics and detectors. We present a modal technique for modelling the behaviour of spectrometers, which allows for the propagation and detection of partially coherent fields, and the inclusion of straylight radiated by warm internal surfaces. We illustrate the technique by modelling the behaviour of the Long Wavelength Band of the proposed SAFARI instrument on the well-studied SPICA mission.Comment: This paper is submitted to Journal Optical Society of America A. When accepted, the paper can be found here: https://opg.optica.org/josaa/home.cf