Exploring the drivers of variation in trophic mismatches:A systematic review of long-term avian studies

Many organisms reproduce in seasonal environments, where selection on timing of reproduction is particularly strong as consumers need to synchronize reproduction with the peaked occurrence of their food. When a consumer species changes its phenology at a slower rate than its resources, this may induce a trophic mismatch, that is, offspring growing up after the peak in food availability, potentially leading to reductions in growth and survival. However, there is large variation in the degree of trophic mismatches as well as in its effects on reproductive output. Here, we explore the potential causes for variation in the strength of trophic mismatches in published studies of birds. Specifically, we ask whether the changes in the degree of mismatch that have occurred over time can be explained by a bird's (a) breeding latitude, (b) migration distance, and/or (c) life-history traits. We found that none of these three factors explain changes in the degree of mismatch over time. Nevertheless, food phenology did advance faster at more northerly latitudes, while shifts in bird phenology did not show a trend with latitude. We argue that the lack of support in our results is attributable to the large variation in the metrics used to describe timing of food availability. We propose a pathway to improve the quantification of trophic mismatches, guided by a more rigorous understanding of links between consumers and their resources

High-Precision U-Pb Zircon Age Calibration of the Global Carboniferous Time Scale and Milankovitch Band Cyclicity in the Donets Basin, Eastern Ukraine

High-precision ID-TIMS U-Pb zircon ages for 12 interstratified tuffs and tonsteins are used to radiometrically calibrate the detailed lithostratigraphic, cyclostratigraphic, and biostratigraphic framework of the Carboniferous Donets Basin of eastern Europe. Chemical abrasion of zircons, use of the internationally calibrated EARTHTIME mixed U-Pb isotope dilution tracer, and improved mass spectrometry guided by detailed error analysis have resulted in an age resolution o

Reassessment of trophic mismatches in Arctic shorebirds

Warming climate induces profound changes in natural environment. Among all it can disrupt or reshape existing food webs. That may result in trophic mismatches, e.g., disordering of trophic interactions between carnivore and its prey. These climatic changes are occurring with much faster rates in Arctic areas. Thus, disrupting of the food webs in Arctic may also occur faster. Numerous of studies are devoted to the mismatch phenomena in insectivorous shorebirds feeding on the tundra arthropods. Nevertheless, the evidences that those disruptions lead to any fitness consequences are currently rather slim. In this thesis I aim to inspect and challenge the currently widely accepted ideas on how trophic mismatches should be measured by critically reviewing literature on trophic mismatches in birds and their effects on fitness, showing the importance on detailed data on food availability and diet for measuring mismatches, and how these data may be applied for better understanding of shorebirds ecology in changing Arctic

Formation of motivation to study school programming based on integration intersubject

The article discusses methods of teaching programming at school, based on dynamic programming computer games

6DCNN with roto-translational convolution filters for volumetric data processing

In this work, we introduce 6D Convolutional Neural Network (6DCNN) designed to tackle the problem of detecting relative positions and orientations of local patterns when processing three-dimensional volumetric data. 6DCNN also includes SE(3)-equivariant message-passing and nonlinear activation operations constructed in the Fourier space. Working in the Fourier space allows significantly reducing the computational complexity of our operations. We demonstrate the properties of the 6D convolution and its efficiency in the recognition of spatial patterns. We also assess the 6DCNN model on several datasets from the recent CASP protein structure prediction challenges. Here, 6DCNN improves over the baseline architecture and also outperforms the state of the art

Food web interactions of breeding Arctic shorebirds are shaped by their elevational distribution: dataset

We describe the spatial position of little stints and red knots in the tundra food web, from both a top-down and a bottom-up perspective, and suggest that these affect shorebird diet and survival. The availability of the key food items for chicks is related to their diet, and, although it is not possible to fully disentangle cause and effect, we find support that the diet differences are explained by elevation. Moreover, the difference in the elevational distribution of shorebird nests impacts their relationships with predators