Biological evaluation of the Belgian beaches by means of terrestrial invertebrates

Beaches belong to the least studied ecosystems, although they contain typical habitats for a large amount of specialised terrestrial invertebrates. This specific beach fauna was quite diverse along the Belgian coast at the beginning of the twentieth century. Especially species bound to organic matter, washed up on the tide line, were well represented. As a result of the development of mass tourism, most of our beaches are subject to mechanical beach cleaning and the suppletion of sand. These activities are believed to be responsible for the degradation of the original habitat. However, documentation on this topic was scarce and evidence of negative effects on local biodiversity was lacking. Therefore, the main goal of this research was to make an inventory of the terrestrial arthropod fauna on Flemish beaches and analysing temporal and spatial variation, in function of abiotic components such as the degree of recreation and the intensity of mechanical beach cleaning. The main conclusion is that a high degree of recreation and mechanical beach cleaning indeed has a negative influence on the richness of the species bound to organic detritus and also induces a change in community structure of terrestrial invertebrates along the Flemish coast. Secondly, predators and even parasites are also indirectly influenced by these anthropogenic disturbances, as a result of the declining prey population. Excluding or at least reducing these impacts along certain sections of the Flemish coast, might ensure the preservation of the organic detritus on the tide line and hence its associated beach fauna

ERP mismatch response to phonological and temporal regularities in speech

Predictions of our sensory environment facilitate perception across domains. During speech perception, formal and temporal predictions may be made for phonotactic probability and syllable stress patterns, respectively, contributing to the efficient processing of speech input. The current experiment employed a passive EEG oddball paradigm to probe the neurophysiological processes underlying temporal and formal predictions simultaneously. The component of interest, the mismatch negativity (MMN), is considered a marker for experience-dependent change detection, where its timing and amplitude are indicative of the perceptual system's sensitivity to presented stimuli. We hypothesized that more predictable stimuli (i.e. high phonotactic probability and first syllable stress) would facilitate change detection, indexed by shorter peak latencies or greater peak amplitudes of the MMN. This hypothesis was confirmed for phonotactic probability: high phonotactic probability deviants elicited an earlier MMN than low phonotactic probability deviants. We do not observe a significant modulation of the MMN to variations in syllable stress. Our findings confirm that speech perception is shaped by formal and temporal predictability. This paradigm may be useful to investigate the contribution of implicit processing of statistical regularities during (a)typical language development.Maastricht University (Grant to BMJ to support women in higher academic positions) and Netherlands Organization for Scientific Research (NWO) 452-16-004info:eu-repo/semantics/publishedVersio

Ghost-busting: Patch occupancy and habitat preferences of Ocyale ghost (Araneae: Lycosidae), a single site endemic in north-western Madagascar

Microendemic species are of great conservation concern due to their vulnerability to stochastic events and environmental change. Therefore, understanding the basic ecology of such organisms is integral to future efforts to conserve them. Here, we present the first ecological study of the only known population of Ocyale ghost (Lycosidae) – the single species within this genus in Madagascar – located at a small lake shore in the north-west of the island. We aimed to reveal spatial patterns of microhabitat selection and patch occupancy in relation to substrate patch covariates, including distance to lake edge, topography, and sand coverage. We found microhabitat selection to be strong in our occupancy models, with plots closer to the lake edge and with a higher proportion of sand showing the highest estimated occupancy. We suggest decreases in prey availability and changes in the physical characteristics of the substrate in relation to the distance from lake shore and sand availability (important for burrowing and temperature regulation), respectively, as potential factors behind occupancy. We discuss our findings in the context of the proportional underrepresentation of invertebrates in conservation research, which threatens the persistence of endemic and microendemic invertebrates in the face of significant global and local environmental change

Homomorphic Training of 30,000 Logistic Regression Models

In this work, we demonstrate the use the CKKS homomorphic encryption scheme to train a large number of logistic regression models simultaneously, as needed to run a genome-wide association study (GWAS) on encrypted data. Our implementation can train more than 30,000 models (each with four features) in about 20 minutes. To that end, we rely on a similar iterative Nesterov procedure to what was used by Kim, Song, Kim, Lee, and Cheon to train a single model [KSKLC18]. We adapt this method to train many models simultaneously using the SIMD capabilities of the CKKS scheme. We also performed a thorough validation of this iterative method and evaluated its suitability both as a generic method for computing logistic regression models, and specifically for GWAS