Genes and gene networks underlying spatial cognition in food-caching chickadees.

Substantial progress has been made in understanding the genetic architecture of phenotypes involved in a variety of evolutionary processes. Behavioral genetics remains, however, among the least understood. We explore the genetic architecture of spatial cognitive abilities in a wild passerine bird, the mountain chickadee (Poecile gambeli).

Modeling the Converse Magnetoelectric Effect in the Low-Frequency Range.

This article is devoted to the theory of the converse magnetoelectric (CME) effect for the longitudinal, bending, longitudinal-shear, and torsional resonance modes and its quasi-static regime. In contrast to the direct ME effect (DME), these issues have not been studied in sufficient detail in the literature. However, in a number of cases, in particular in the study of low-frequency ME antennas, the results obtained are of interest.

Quantitative Analyses of Coupling in Hybrid Zones.

In hybrid zones, whether barrier loci experience selection mostly independently or as a unit depends on the ratio of selection to recombination as captured by the coupling coefficient. Theory predicts a sharper transition between an uncoupled and coupled system when more loci affect hybrid fitness. However, the extent of coupling in hybrid zones has rarely been quantified.

Modeling the Magnetoelectric Composites in a Wide Frequency Range.

This article presents a general theory of the ME effect in composites in the low- and high-frequency ranges. Besides the quasi-static region, the area of electromechanical resonance, including longitudinal, bending, longitudinal shear, and torsional modes, is considered in more detail. To demonstrate the theory, expressions of ME voltage coefficients are obtained for symmetric and asymmetric layered structures.

Thermal acclimation in a non-migratory songbird occurs via changes to thermogenic capacity, but not conductance.

Thermoregulatory performance can be modified through changes in various subordinate traits, but the rate and magnitude of change in these traits is poorly understood. We investigated flexibility in traits that affect thermal balance between black-capped chickadees (Poecile atricapillus) acclimated for 6 weeks to cold (-5°C) or control (23°C) environments (n=7 per treatment). We made repeated measurements of basal and summit metabolic rates via flow-through respirometry and of body composition using quantitative magnetic resonance of live birds.

Technological advances in protein extraction, structure improvement and assembly, digestibility and bioavailability of plant-based foods.

Plant-based foods are being considered seriously to replace traditional animal-origin foods for various reasons. It is well known that animals release large amounts of greenhouse gases into the environment during feeding, and eating animal-origin foods may also cause some health problems. Moreover, animal resources will likely be in short supply as the world population grows.

Modeling the Composites for Magnetoelectric Microwave Devices.

Many studies of the ME effect have been carried out in the microwave range in connection with the possibility of creating new electronic devices. One of the main microwave ME effects is the FMR line shift in an electric field, and the purpose of this article is to compare the FMR line shift in the ME structure in an electric field for a number of ferromagnetic metals, their alloys, and YIG ferrite using various piezoelectrics. This article discusses the regimes when the bias field is directed along the main axes of the magnetic component, while, as is known, the observed effect is due only to deformation.

Physics of Composites for Low-Frequency Magnetoelectric Devices.

The article discusses the physical foundations of the application of the linear magnetoelectric (ME) effect in composites for devices in the low-frequency range, including the electromechanical resonance (EMR) region. The main theoretical expressions for the ME voltage coefficients in the case of a symmetric and asymmetric composite structure in the quasi-static and resonant modes are given. The area of EMR considered here includes longitudinal, bending, longitudinal shear, and torsional modes.

The genetic basis of spatial cognitive variation in a food-caching bird.

Spatial cognition is used by most organisms to navigate their environment. Some species rely particularly heavily on specialized spatial cognition to survive, suggesting that a heritable component of cognition may be under natural selection. This idea remains largely untested outside of humans, perhaps because cognition in general is known to be strongly affected by learning and experience.

Variable Signatures of Selection Despite Conserved Recombination Landscapes Early in Speciation.

Recently diverged taxa often exhibit heterogeneous landscapes of genomic differentiation, characterized by regions of elevated differentiation on an otherwise homogeneous background. While divergence peaks are generally interpreted as regions responsible for reproductive isolation, they can also arise due to background selection, selective sweeps unrelated to speciation, and variation in recombination and mutation rates. To investigate the association between patterns of recombination and landscapes of genomic differentiation during the early stages of speciation, we generated fine-scale recombination maps for six southern capuchino seedeaters (Sporophila) and two subspecies of White Wagtail (Motacilla alba), two recent avian radiations in which divergent selection on pigmentation genes has likely generated peaks of differentiation.

Freezing and freeze-drying of strawberries with an additional effect of micro-vibrations.

Our research focuses on the formation of ice crystals and evaluating the structure of preserved frozen and freeze-dried strawberries. Strawberries were frozen in two ways. One-half of strawberries were frozen at - 30 °C under conditions of convective heat exchange.

Asymmetric introgression reveals the genetic architecture of a plumage trait.

Genome-wide variation in introgression rates across hybrid zones offers a powerful opportunity for studying population differentiation. One poorly understood pattern of introgression is the geographic displacement of a trait implicated in lineage divergence from genome-wide population boundaries. While difficult to interpret, this pattern can facilitate the dissection of trait genetic architecture because traits become uncoupled from their ancestral genomic background.

Migratory divides coincide with reproductive barriers across replicated avian hybrid zones above the Tibetan Plateau.

Migratory divides are proposed to be catalysts for speciation across a diversity of taxa. However, it is difficult to test the relative contributions of migratory behaviour vs. other divergent traits to reproductive isolation.

Unifying Theoretical and Empirical Perspectives on Genomic Differentiation.

Differentiation is often heterogeneous across the genomes of diverging populations. Despite substantial recent progress, much work remains to improve our abilities to connect genomic patterns to underlying evolutionary processes. Crosstalk between theoretical and empirical research has shaped the field of evolutionary genetics since its foundation and needs to be greatly enhanced for modern datasets.

Using Networks to Connect Individual-Level Reproductive Behavior to Population Patterns.

We propose an application of network analysis to determine which traits and behaviors predict fertilizations within and between populations. This approach quantifies how reproductive behavior between individuals shapes patterns of selection and gene flow, filling an important gap in our understanding of the connection between evolutionary processes and emergent patterns.

Extensive phenotypic diversification coexists with little genetic divergence and a lack of population structure in the White Wagtail subspecies complex (Motacilla alba).

Geographically clustered phenotypes often demonstrate consistent patterns in molecular markers, particularly mitochondrial DNA (mtDNA) traditionally used in phylogeographic studies. However, distinct evolutionary trajectories among traits and markers can lead to their discordance. First, geographic structure in phenotypic traits and nuclear molecular markers can be co-aligned but inconsistent with mtDNA (mito-nuclear discordance).

[The principal and auxiliary immunohistochemical markers of intravital mechanical strangulation asphyxia].

Unlabelled: The objective of the present study was the evaluation of the auxiliary methods for the diagnostics of the intravital formation of the constriction marks; the secondary objective was to determine the pace at which the death and asphyxia occur.

Material And Methods: The materials on which the study was based included 17 cases of mechanical strangulation asphyxia involving 13 men and 4 women at the age from 8 to 28 years. All cases of hanging were associated with different blood alcohol levels.

Effects of assortative mate choice on the genomic and morphological structure of a hybrid zone between two bird subspecies.

Phenotypic differentiation plays an important role in the formation and maintenance of reproductive barriers. In some cases, variation in a few key aspects of phenotype can promote and maintain divergence; hence, the identification of these traits and their associations with patterns of genomic divergence is crucial for understanding the patterns and processes of population differentiation. We studied hybridization between the alba and personata subspecies of the white wagtail (Motacilla alba), and quantified divergence and introgression of multiple morphological traits and 19,437 SNP loci on a 3,000 km transect.

Hybridization Associated with Cycles of Ecological Succession in a Passerine Bird.

Identifying the diversity of contexts that can lead to hybridization is important for understanding its prevalence and dynamics in natural populations. Despite the potential of ecological succession to dramatically alter species co-occurrence and abundances, it is unknown whether it directly promotes hybridization and, if so, has long-lasting consequences. Here, we summarize 30 years of survey data across 10 populations to show that in western and mountain bluebirds, heterospecific pairing occurs during repeatable and transient colonization events at the early stages of species turnover.

Genomic variation across two barn swallow hybrid zones reveals traits associated with divergence in sympatry and allopatry.

Hybrid zones are geographic regions where isolating barriers between divergent populations are challenged by admixture. Identifying factors that facilitate or inhibit hybridization in sympatry can illuminate the processes that maintain those reproductive barriers. We analysed patterns of hybridization and phenotypic variation across two newly discovered hybrid zones between three subspecies of barn swallow (Hirundo rustica).

Magnetoelectric Current Sensors.

In this work a magnetoelectric (ME) current sensor design based on a magnetoelectric effect is presented and discussed. The resonant and non-resonant type of ME current sensors are considered. Theoretical calculations of the ME current sensors by the equivalent circuit method were conducted.

Effects of asymmetric nuclear introgression, introgressive mitochondrial sweep, and purifying selection on phylogenetic reconstruction and divergence estimates in the Pacific clade of Locustella warblers.

When isolated but reproductively compatible populations expand geographically and meet, simulations predict asymmetric introgression of neutral loci from a local to invading taxon. Genetic introgression may affect phylogenetic reconstruction by obscuring topology and divergence estimates. We combined phylogenetic analysis of sequences from one mtDNA and 12 nuDNA loci with analysis of gene flow among 5 species of Pacific Locustella warblers to test for presence of genetic introgression and its effects on tree topology and divergence estimates.

Limited phylogeographic signal in sex-linked and autosomal loci despite geographically, ecologically, and phenotypically concordant structure of mtDNA variation in the Holarctic avian genus Eremophila.

Phylogeographic studies of Holarctic birds are challenging because they involve vast geographic scale, complex glacial history, extensive phenotypic variation, and heterogeneous taxonomic treatment across countries, all of which require large sample sizes. Knowledge about the quality of phylogeographic information provided by different loci is crucial for study design. We use sequences of one mtDNA gene, one sex-linked intron, and one autosomal intron to elucidate large scale phylogeographic patterns in the Holarctic lark genus Eremophila.

Geographic mode of speciation in a mountain specialist Avian family endemic to the Palearctic.

Mountains host greater avian diversity than lowlands at the same latitude due to their greater diversity of habitats stratified along an elevation gradient. Here we test whether this greater ecological heterogeneity promotes sympatric speciation. We selected accentors (Prunellidae), an avian family associated with mountains of the Palearctic, as a model system.