Complementation of Subquandles

Saki and Kiani proved that the subrack lattice of a rack $R$ is necessarily complemented if $R$ is finite but not necessarily complemented if $R$ is infinite. In this paper, we investigate further avenues related to the complementation of subquandles. Saki and Kiani's example of an infinite rack without complements is a quandle, which is neither ind-finite nor profinite. We provide an example of an ind-finite quandle whose subobject lattice is not complemented, and conjecture that profinite quandles have complemented subobject lattices. Additionally, we provide a complete classification of subquandles whose set-theoretic complement is also a subquandle, which we call \textit{strongly complemented}, and provide a partial transitivity criterion for the complementation in chains of strongly complemented subquandles. One technical lemma used in establishing this is of independent interest: the inner automorphism group of a subquandle is always a subquotient of the inner automorphism group of the ambient quandle

Differential Influence of Clonal Integration on Morphological and Growth Responses to Light in Two Invasive Herbs

Background and aims: In contrast to seeds, high sensitivity of vegetative fragments to unfavourable environments may limit the expansion of clonal invasive plants. However, clonal integration promotes the establishment of propagules in less suitable habitats and may facilitate the expansion of clonal invaders into intact native communities. Here, we examine the influence of clonal integration on the morphology and growth of ramets in two invasive plants, Alternanthera philoxeroides and Phyla canescens, under varying light conditions. Methods: In a greenhouse experiment, branches, connected ramets and severed ramets of the same mother plant were exposed under full sun and 85 % shade and their morphological and growth responses were assessed. Key results: The influence of clonal integration on the light reaction norm (connection6light interaction) of daughter ramets was species-specific. For A. philoxeroides, clonal integration evened out the light response (total biomass, leaf mass per area, and stem number, diameter and length) displayed in severed ramets, but these connection6light interactions were largely absent for P. canescens. Nevertheless, for both species, clonal integration overwhelmed light effect in promoting the growth of juvenile ramets during early development. Also, vertical growth, as an apparent shade acclimation response, was more prevalent in severed ramets than in connected ramets. Finally, unrooted branches displayed smaller organ size and slower growth than connected ramets, but the pattern of light reaction was similar, suggesting mothe

Phenomic versus genomic prediction—A comparison of prediction accuracies for grain yield in hard winter wheat lines

Abstract Common bread wheat (Triticum aestivum L.) is a key component of global diets, but the genetic improvement of wheat is not keeping pace with the growing demands of the world's population. To increase efficiency and reduce costs, breeding programs are rapidly adopting the use of unoccupied aerial vehicles to conduct high‐throughput spectral analyses. This study examined the effectiveness of multispectral indices in predicting grain yield compared to genomic prediction. Multispectral data were collected on advanced generation yield nursery trials during the 2019–2021 growing seasons in the Colorado State University Wheat Breeding Program. Genome‐wide genotyping was performed on these advanced generations and all plots were harvested to measure grain yield. Two methods were used to predict grain yield: genomic estimated breeding values (GEBVs) generated by a genomic best linear unbiased prediction (gBLUP) model and phenomic phenotypic estimates (PPEs) using only spectral indices via multiple linear regression (MLR), k‐nearest neighbors (KNNs), and random forest (RF) models. In cross‐validation, PPEs produced by MLR, KNN, and RF models had higher prediction accuracy (r¯:0.41≤r¯≤0.48) than GEBVs produced by gBLUP ( r¯=0.35). In leave‐one‐year‐out forward validation using only multispectral data for 2020 and 2021, PPEs from MLR and KNN models had higher prediction accuracy of grain yield than GEBVs of those same lines. These findings suggest that a limited number of spectra may produce PPEs that are more accurate than or equivalently accurate as GEBVs derived from gBLUP, and this method should be evaluated in earlier development material where sequencing is not feasible

Vertical profile of epiphytes in a Pacific Northwest old-growth forest

The vertical stratification of epiphytes is a striking feature of Northwestern forests that surely influences the distribution of other organisms in the canopy. We are just now learning how and why the stratification varies from place to place. Functional groups of epiphytes were stratified with height in an old-growth Pseudotsuga-Tsuga forest in the following order, from the ground up: bryophytes, cyanolichens, and alectorioid lichens. Other macrolichens (mainly green-algal foliose) were found throughout the vertical profile, but their relative abundance peaked in the middle to upper canopy. Cyanolichens (mainly Lobaria oregana) were concentrated in the "light transition zone." The light transition zone is the range of heights in which we found abrupt transitions in light transmittance by the canopy. This zone extends from about 13 to 37 m in height, in an overall canopy height of 50-60 m. Bryophytes were concentrated between the ground and the middle of the light transition zone. The biomass of epiphytic macrolichens was about 1.3 metric tons/ha, composed of approximately 42% cyanolichens, 28% alectorioid lichens, and 30% other lichens. We draw the following methodological conclusions. Using quadrats as windows from a suspended gondola overestimates the relative abundance of alectorioid lichens and underestimates cyanolichens and other lichens. Using 14, 2-m radius lichen litter plots is barely adequate to represent the epiphytic macrolichens of an old-growth stand. Ground-based canopy density measurements (photographic and densiometer) are insufficient to characterize the openness of a vertical transect, because of interference from understory vegetatio

Vertical profile of epiphytes in a Pacific Northwest old-growth forest

The vertical stratification of epiphytes is a striking feature of Northwestern forests that surely influences the distribution of other organisms in the canopy. We are just now learning how and why the stratification varies from place to place. Functional groups of epiphytes were stratified with height in an old-growth Pseudotsuga-Tsuga forest in the following order, from the ground up: bryophytes, cyanolichens, and alectorioid lichens. Other macrolichens (mainly green-algal foliose) were found throughout the vertical profile, but their relative abundance peaked in the middle to upper canopy. Cyanolichens (mainly Lobaria oregana) were concentrated in the "light transition zone." The light transition zone is the range of heights in which we found abrupt transitions in light transmittance by the canopy. This zone extends from about 13 to 37 m in height, in an overall canopy height of 50-60 m. Bryophytes were concentrated between the ground and the middle of the light transition zone. The biomass of epiphytic macrolichens was about 1.3 metric tons/ha, composed of approximately 42% cyanolichens, 28% alectorioid lichens, and 30% other lichens. We draw the following methodological conclusions. Using quadrats as windows from a suspended gondola overestimates the relative abundance of alectorioid lichens and underestimates cyanolichens and other lichens. Using 14, 2-m radius lichen litter plots is barely adequate to represent the epiphytic macrolichens of an old-growth stand. Ground-based canopy density measurements (photographic and densiometer) are insufficient to characterize the openness of a vertical transect, because of interference from understory vegetationMcCune et al "Vertical profile of epiphytes in a Pacific Northwest old-growth forest." Northwest Science. 1997; 71(2): 145-15