Extended Peer Communities: Appraising the contributions of tacit knowledges in climate change decision-making

This paper explores the implications of assessing tacit knowledges of climatic change in extended peer communities, as applied in two European research projects on climate action. Post-normal science (PNS) proposes the extension of the peer community to co-produce better quality knowledge for decision-making on issues like climate change, where facts are uncertain, values in dispute, stakes high and decisions urgent. The paper has two aims. The first, more practical, is to explore methods for critically appraising tacit knowledges for climate action, using the example of two ongoing research projects. The second, more conceptual, is to improve practices and discourses surrounding tacit knowledge in current PNS praxis, with close consideration to the implications and challenges involved in including these forms of knowledge in decision making processes. By exploring theoretical perspectives on the topic of tacit knowledge, four challenges facing extended peer communities in engaging with tacit forms of knowledge have been identified: communication, representation, appropriation, and assessment.publishedVersio

Experimental Observation of Modulational Instability in Crossing Surface Gravity Wavetrains

The coupled nonlinear Schrödinger equation (CNLSE) is a wave envelope evolution equation applicable to two crossing, narrow-banded wave systems. Modulational instability (MI), a feature of the nonlinear Schrödinger wave equation, is characterized (to first order) by an exponential growth of sideband components and the formation of distinct wave pulses, often containing extreme waves. Linear stability analysis of the CNLSE shows the effect of crossing angle, θ, on MI, and reveals instabilities between 0◦ < θ < 35◦, 46◦ < θ < 143◦, and 145◦ < θ < 180◦. Herein, the modulational stability of crossing wavetrains seeded with symmetrical sidebands is determined experimentally from tests in a circular wave basin. Experiments were carried out at 12 crossing angles between 0◦ ≤ θ ≤ 88◦, and strong unidirectional sideband growth was observed. This growth reduced significantly at angles beyond θ ≈ 20◦, reaching complete stability at θ = 30–40◦. We find satisfactory agreement between numerical predictions (using a time-marching CNLSE solver) and experimental measurements for all crossing angles

Evaluation of a temporal causal model for predicting the mood of clients in an online therapy

Background Self-reported client assessments during online treatments enable the development of statistical models for the prediction of client improvement and symptom development. Evaluation of these models is mandatory to ensure their validity. Methods For this purpose, we suggest besides a model evaluation based on study data the use of a simulation analysis. The simulation analysis provides insight into the model performance and enables to analyse reasons for a low predictive accuracy. In this study, we evaluate a temporal causal model (TCM) and show that it does not provide reliable predictions of clients' future mood levels. Results Based on the simulation analysis we investigate the potential reasons for the low predictive performance, for example, noisy measurements and sampling frequency. We conclude that the analysed TCM in its current form is not sufficient to describe the underlying psychological processes. Conclusions The results demonstrate the importance of model evaluation and the benefit of a simulation analysis. The current manuscript provides practical guidance for conducting model evaluation including simulation analysis

Large Scale Structure traced by Molecular Gas at High Redshift

We present observations of redshifted CO(1-0) and CO(2-1) in a field containing an overdensity of Lyman break galaxies (LBGs) at z=5.12. Our Australia Telescope Compact Array observations were centered between two spectroscopically-confirmed z=5.12 galaxies. We place upper limits on the molecular gas masses in these two galaxies of M(H_2) <1.7 x 10^10 M_sun and <2.9 x 10^9 M_sun (2 sigma), comparable to their stellar masses. We detect an optically-faint line emitter situated between the two LBGs which we identify as warm molecular gas at z=5.1245 +/- 0.0001. This source, detected in the CO(2-1) transition but undetected in CO(1-0), has an integrated line flux of 0.106 +/- 0.012 Jy km/s, yielding an inferred gas mass M(H_2)=(1.9 +/- 0.2) x 10^10 M_sun. Molecular line emitters without detectable counterparts at optical and infrared wavelengths may be crucial tracers of structure and mass at high redshift.Comment: 4 pages, accepted for publication in ApJ Letter

Cattle CODE: An Economic Model for Determining Byproduct Returns for Feedlot Cattle

Cattle CODE — Coproduct Optimizer Decision Evaluator — is a model developed to predict performance and economic returns when byproducts are fed to finishing cattle. Four scenarios were evaluated to illustrate how the model works and to show sensitivity to corn price and distance from the ethanol plant, which resulted in positive returns for feeding WDGS, Sweet Bran, or DDGS up to 50% of diet DM and under 100 miles distance from the ethanol plant to the feedlot

Cattle CODE: An Economic Model for Determining Byproduct Returns for Feedlot Cattle

Cattle CODE — Coproduct Optimizer Decision Evaluator — is a model developed to predict performance and economic returns when byproducts are fed to finishing cattle. Four scenarios were evaluated to illustrate how the model works and to show sensitivity to corn price and distance from the ethanol plant, which resulted in positive returns for feeding WDGS, Sweet Bran, or DDGS up to 50% of diet DM and under 100 miles distance from the ethanol plant to the feedlot

The XXL Survey V: Detection of the Sunyaev-Zel'dovich effect of the Redshift 1.9 Galaxy Cluster XLSSU J021744.1-034536 with CARMA

We report the detection of the Sunyaev-Zel'dovich (SZ) effect of galaxy cluster XLSSU J021744.1-034536, using 30 GHz CARMA data. This cluster was discovered via its extended X-ray emission in the XMM-Newton Large Scale Structure survey, the precursor to the XXL survey. It has a photometrically determined redshift $z=1.91^{+0.19}_{-0.21}$, making it among the most distant clusters known, and nominally the most distant for which the SZ effect has been measured. The spherically integrated Comptonization is $Y_{500}=(3.0\pm0.4)\times 10^{-12}$, a measurement which is relatively insensitive to assumptions regarding the size and redshift of the cluster, as well as the background cosmology. Using a variety of locally calibrated cluster scaling relations extrapolated to z~2, we estimate a mass $M_{500} \sim (1$-$2)\times 10^{14}M_{sun}$ from the X-ray flux and SZ signal. The measured properties of this cluster are in good agreement with the extrapolation of an X-ray luminosity-SZ effect scaling relation calibrated from clusters discovered by the South Pole Telescope at higher masses and lower redshifts. The full XXL-CARMA sample will provide a more complete, multi-wavelength census of distant clusters in order to robustly extend the calibration of cluster scaling relations to these high redshifts.Comment: ApJ, in press. 9 pages, 4 figures, 4 table

Highly directionally spread, overturning breaking waves modelled with Smoothed Particle Hydrodynamics: A case study involving the Draupner wave

Wave breaking in the ocean affects the height of extreme waves, energy dissipation, and interaction between the atmosphere and upper ocean. Numerical modelling is a critical step in understanding the physics of wave breaking and offers insight that is hard to gain from field data or experiments. High-fidelity numerical modelling of three-dimensional breaking waves is extremely challenging. Conventional grid-based numerical methods struggle to model the steep and double-valued free surfaces that occur during wave breaking. The Smoothed Particle Hydrodynamics (SPH) method does not fall prey to these issues. Herein, we examine the SPH method's ability to model highly directionally spread overturning breaking waves by numerically reproducing the experiments presented in McAllister et al. (2019). We find that the SPH method reproduces the experimental observations well; when comparing experimental and numerical measurements we achieve coefficient of determination values of 0.92−0.95, with some smaller-scale features less well reproduced owing to finite resolution. We also examine aspects of the simulated wave's geometry and kinematics and find that existing breaking criteria are difficult to apply in highly directionally spread conditions.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Environmental Fluid Mechanic