Pattern orientation in finite domains without boundaries

We investigate the orientation of nonlinear stripe patterns in finite domains. Motivated by recent experiments, we introduce a control parameter drop from supercritical inside a domain to subcritical outside without boundary conditions at the domain border. As a result, stripes align perpendicular to shallow control parameter drops. For steeper drops, non-adiabatic effects lead to a surprising orientational transition to parallel stripes with respect to the borders. We demonstrate this effect in terms of the Brusselator model and generic amplitude equations

Barents Sea Shrimp - stock assessment report 2022/23

Since the 1980s, the Barents Sea has gone from a situation with high fishing pressure, cold conditions and low demersal fish stock levels, to the current situation with high levels of demersal fish stocks, reduced fishing pressure and warm conditions.Barents Sea Shrimp - stock assessment report 2022/23publishedVersio

Mistrust, disinforming news, and vote choice: A panel survey on the origins and consequences of believing disinformation in the 2017 German parliamentary election

In this paper, we address the question of whether disinforming news spread online possesses the power to change the prevailing political circumstances during an election campaign. We highlight factors for believing disinformation that until now have received little attention, namely trust in news media and trust in politics. A panel survey in the context of the 2017 German parliamentary election (N = 989) shows that believing disinforming news had a specific impact on vote choice by alienating voters from the main governing party (i.e., the CDU/CSU), and driving them into the arms of right-wing populists (i.e., the AfD). Furthermore, we demonstrate that the less one trusts in news media and politics, the more one believes in online disinformation. Hence, we provide empirical evidence for Bennett and Livingston’s notion of a disinformation order, which forms in opposition to the established information system to disrupt democracy

Advice on fishing opportunities for Barents Sea shrimp in 2023

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Advice on fishing opportunities for Barents Sea shrimp in 2024

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Adaptation and mislocalization fields for saccadic outward adaptation in humans

Adaptive shortening of a saccade influences the metrics of other saccades within a spatial window around the adapted target. Within this adaptation field visual stimuli presented before an adapted saccade are mislocalized in proportion to the change of the saccade metric. We investigated the saccadic adaptation field and associated localization changes for saccade lengthening, or outward adaptation. We measured the adaptation field for two different saccade adaptations (14 deg to 20 deg and 20 deg to 26 deg) by testing transfer to 34 different target positions. We measured localization judgements by asking subjects to localize a probe flashed before saccade onset. The amount of adaptation transfer differed for different target locations. It increased with increases of the horizontal component of the saccade and remained largely constant with deviation of the vertical component of the saccade. Mislocalization of probes inside the adaptation field was correlated with the amount of adaptation of saccades to the probe location. These findings are consistent with the assumption that oculomotor space and perceptual space are linked to each other

Systematic extension of the Cahn-Hilliard model for motility-induced phase separation

We consider a continuum model for motility-induced phase separation (MIPS) of active Brownian particles [J. Chem. Phys. 142, 224149 (2015)]. Using a recently introduced perturbative analysis [Phys. Rev. E 98, 020604(R) (2018)], we show that this continuum model reduces to the classic Cahn-Hilliard (CH) model near the onset of MIPS. This makes MIPS another example of the so-called active phase separation. We further introduce a generalization of the perturbative analysis to the next higher order. This results in a generic higher order extension of the CH model for active phase separation. Our analysis establishes the mathematical link between the basic mean-field MIPS model on the one hand, and the leading order and extended CH models on the other hand. Comparing numerical simulations of the three models, we find that the leading order CH model agrees nearly perfectly with the full continuum model near the onset of MIPS. We also give estimates of the control parameter beyond which the higher order corrections become relevant and compare the extended CH model to recent phenomenological models.Comment: 10 pages, 5 figure

Common trends in recruitment dynamics of north-east Atlantic fish stocks and their links to environment, ecology and management

Recruitment dynamics are challenging to assess or predict because of the many underlying drivers that vary in their relevance over time and space. Stock size, demographic and trait composition, condition and distribution of spawning fish and the spatio‐temporal dynamics of trophic and environmental interactions all influence recruitment processes. Exploring common patterns among stocks and linking them to potential drivers may therefore provide insights into key mechanisms of recruitment dynamics. Here, we analysed stock‐recruitment data of 64 stocks from the north‐east Atlantic Ocean for common trends in variation and synchrony among stocks using correlation, cluster and dynamic factor analyses. We tested common trends in recruitment success for relationships with large‐scale environmental processes as well as stock state indicators, and we explored links between recruitment success and demographic, environmental and ecological variables for a subset of individual stocks. The results revealed few statistically significant correlations between stocks but showed that underlying common trends in recruitment success are linked to environmental indices and management indicators. Statistical analyses confirmed previously suggested relationships of environmental–ecological factors such as the subpolar gyre and Norwegian coastal current with specific stocks, and indicated a large relevance of spawning stock biomass and demographics, as well as predation, whereas other suggested relationships were not supported by the data. Our study shows that despite persistent challenges in determining drivers of recruitment due to poor data quality and unclear mechanisms, combining different data analysis techniques can improve our understanding of recruitment dynamics in fish stocks.publishedVersio

Pre-catch and discard mortality in Northeast Atlantic herring and mackerel fisheries: consequences for stock estimates and advice

Unaccounted mortality caused by discarding or pre-catch losses is a major challenge for fisheries management. In pelagic fisheries, a considerable proportion of catches may be lost due to intentional release of unwanted catch (slipping) or net bursts (fishing net tears due to the weight of the catch). Here we review and estimate ranges of discard and pre-catch mortality for two important pelagic fisheries, the Northeast Atlantic (NEA) mackerel and Norwegian spring spawning (NSS) herring, and explore the effects on stock estimates and catch advice. We show that mortality caused by discarding, slipping, and net bursts is unknown but probably corresponds to a considerable percentage of total registered catches. Including estimated unaccounted mortality into assessment models leads to underestimation of the stock levels by 3.7–19.5% and 2.8–6.8% for NEA mackerel and NSS herring, respectively, corresponding to up to several million tonnes of fish that die annually due to fishing without being landed. If discard and pre-catch mortality were eliminated, allowed catches could increase by 10–20%. We demonstrate that unaccounted mortality in pelagic fisheries may be substantial, affecting stock estimates and catch advice. This may undermine the sustainable management and efficient use of pelagic resources.publishedVersio