We demonstrate a monolithic frequency converter incorporating up to four tuning degrees of freedom, three temperature and one strain, allowing resonance of pump and generated wavelengths simultaneous with optimal phase-matching. With a Rb-doped periodically-poled potassium titanyl phosphate (KTP) implementation, we demonstrate efficient continuous-wave second harmonic generation from 795 to 397, with low-power efficiency of 72% and high-power slope efficiency of 4.5%. The measured performance shows good agreement with theoretical modeling of the device. We measure optical bistability effects, and show how they can be used to improve the stability of the output against pump frequency and amplitude variations.
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Reinstatement of memory-related neural activity measured with high temporal precision potentially provides a useful index for real-time monitoring of the timing of activation of memory content during cognitive processing. The utility of such an index extends to any situation where one is interested in the (relative) timing of activation of different sources of information in memory, a paradigm case of which is tracking lexical activation during language processing. Essential for this approach is that memory reinstatement effects are robust, so that their absence (in the average) definitively indicates that no lexical activation is present. We used electroencephalography to test the robustness of a reported subsequent memory finding involving reinstatement of frequency-specific entrained oscillatory brain activity during subsequent recognition. Participants learned lists of words presented on a background flickering at either 6 or 15 Hz to entrain a steady-state brain response. Target words subsequently presented on a non-flickering background that were correctly identified as previously seen exhibited reinstatement effects at both entrainment frequencies. Reliability of these statistical inferences was however critically dependent on the approach used for multiple comparisons correction. We conclude that effects are not robust enough to be used as a reliable index of lexical activation during language processing.
MULTIFILE
Inulin is a soluble dietary fibre, also classified as a prebiotic, extracted from chicory roots. The present study aimed to determine the effect of consumption of native chicory inulin on the stool frequency of middle-aged to older adults (40–75 years old) with uncomfortably but not clinically relevant low stool frequency, specified as two to four days without bowel movements per week. Two randomised, double blind, placebo-controlled crossover trials were conducted using similar protocols in differing populations. Trial A was conducted in Amsterdam, The Netherlands and subsequently Trial B was conducted in Newcastle, United Kingdom. Both trials involved supplementation for 5 weeks with 10 g per day of inulin or placebo, a washout period of 2 weeks, and then crossed over to receive the other treatment. In Trial B, faecal gut microbiota composition was assessed using 16S rRNA gene sequencing. In Trial A, which 10 volunteers completed, the stool frequency was significantly increased to an average 4.9 ± 0.23 (SEM) times per week during inulin periods versus 3.6 ± 0.25 in the periods with placebo (p = 0.01). In contrast, in Trial B which 20 volunteers completed, there was no significant effect of the inulin on stool frequency (7.5 ± 2.1 times per week with inulin, 8.1 ± 3.0 with placebo, p = 0.35). However, many subjects in Trial B had a stool frequency >5 per week also for the placebo period, in breach of the inclusion criteria. Combining the data of 16 low stool frequency subjects from Trials A and B showed a significant effect of inulin to increase stool frequency from 4.1 to 5.0 per week (p = 0.032). Regarding secondary outcomes, stool consistency was significantly softer with inulin treatment compared to placebo periods, it increased 0.29 on the Bristol stool scale (p = 0.008) when data from all subjects of Trials A and B were combined. No other differences in bowel habit parameters due to inulin consumption were significant. None of the differences in specific bacterial abundance, alpha or beta diversity were significant, however the trends were in directions consistent with published studies on other types of inulin. We conclude that 10 g per day of native chicory inulin can increase stool frequency in subjects with low stool frequency.
MULTIFILE
‘Dieren in de dijk’ aims to address the issue of animal burrows in earthen levees, which compromise the integrity of flood protection systems in low-lying areas. Earthen levees attract animals that dig tunnels and cause damages, yet there is limited scientific knowledge on the extent of the problem and effective approaches to mitigate the risk. Recent experimental research has demonstrated the severe impact of animal burrows on levee safety, raising concerns among levee management authorities. The consortium's ambition is to provide levee managers with validated action perspectives for managing animal burrows, transitioning from a reactive to a proactive risk-based management approach. The objectives of the project include improving failure probability estimation in levee sections with animal burrows and enhancing risk mitigation capacity. This involves understanding animal behavior and failure processes, reviewing existing and testing new deterrence, detection, and monitoring approaches, and offering action perspectives for levee managers. Results will be integrated into an open-access wiki-platform for guidance of professionals and in education of the next generation. The project's methodology involves focus groups to review the state-of-the-art and set the scene for subsequent steps, fact-finding fieldwork to develop and evaluate risk reduction measures, modeling failure processes, and processing diverse quantitative and qualitative data. Progress workshops and collaboration with stakeholders will ensure relevant and supported solutions. By addressing the knowledge gaps and providing practical guidance, the project aims to enable levee managers to effectively manage animal burrows in levees, both during routine maintenance and high-water emergencies. With the increasing frequency of high river discharges and storm surges due to climate change, early detection and repair of animal burrows become even more crucial. The project's outcomes will contribute to a long-term vision of proactive risk-based management for levees, safeguarding the Netherlands and Belgium against flood risks.
Fontys University of Applied Science’s Institute of Engineering, and the Dutch Institute for Fundamental Energy Research (DIFFER) are proposing to set up a professorship to develop novel sensors for fusion reactors. Sensors are a critical component to control and optimise the unstable plasma of Tokamak reactors. However, sensor systems are particularly challenging in fusion-plasma facing components, such as the divertor. The extreme conditions make it impossible to directly incorporate sensors. Furthermore, in advanced reactor concepts, such as DEMO, access to the plasma via ports will be extremely limited. Therefore, indirect or non-contact sensing modalities must be employed. The research group Distributed Sensor Systems (DSS) will develop microwave sensor systems for characterising the plasma in a tokamak’s divertor. DSS will take advantage of recent rapid developments in high frequency integrated circuits, found, for instance, in automotive radar systems, to develop digital reflectometers. Access through the divertor wall will be achieved via surface waveguide structures. The waveguide will be printed using 3D tungsten printing that has improved precision, and reduced roughness. These components will be tested for durability at DIFFER facilities. The performance of the microwave reflectometer, including waveguides, will be tested by using it to analyse the geometry and dynamics of the Magnum PSI plasma beam. The development of sensor-based systems is an important aspect in the integrated research and education program in Electrical Engineering, where DSS is based. The sensing requirements from DIFFER offers an interesting and highly relevant research theme to DSS and exciting projects for engineering students. Hence, this collaboration will strengthen both institutes and the educational offerings at the institute of engineering. Furthermore millimeter wave (mmWave) sensors have a wide range of potential applications, from plasma characterisation (as in this proposal) though to waste separation. Our research will be a step towards realising these broader application areas.
The FlexEd project is intended as an extension of the Leisure Choices and Wellbeing (LCW) project which is now very concretely and definitively planned to run from November 2024 through January 2026. The LCW project is facilitated by the Academy for Leisure. The Leisure Choices and Wellbeing, The LCW project will use a weekly longitudinal questionnaire of 200 individuals (final sample after attrition) over 40 weeks to measure leisure activity planning, participation, and wellbeing. The three main aims of the project are to uncover the roles of 1) social interaction during leisure, 2) novelty/change in routine during leisure, and 3) leisure travel duration and frequency, in explaining individuals’ and families’ wellbeing. By measuring changes in these leisure activities week to week, it will be possible to uncover how development in leisure choices accrues to improved well-being over time. Societal issueFlexibility in the education calendar for better vacation impacts in society.Collaborative partnersCELTH, ANVR.
