Gamete sex and elevation affect genetically based variation for unreduced gamete production in a mixed-ploidy plant.

Premise: Unreduced gametes are the primary mechanism of neopolyploid formation. Their production in diploid populations is arguably maladaptive, but the magnitude and patterns of genetically based variation maintained in natural populations are poorly understood.

Methods: We examined variation in male and female unreduced gamete production among plants from different elevations in fireweed, Chamerion angustifolium, grown in a common environment.

Demographic and reproductive impacts of hybridization unrelated to hybrid viability in a native plant.

Premise: Introduced species can influence native congeners through production of hybrids and introgression, but impacts not involving viable hybrids, such as reduced conspecific offspring and increased asexual seed production, are rarely examined. Here we tested for these demographic and reproductive consequences of hybridization between introduced, domesticated apple (Malus domestica) and native crabapple (M. coronaria) in southern Canada.

Predictive Molecular Design and Structure-Property Validation of Novel Terpene-Based, Sustainably Sourced Bacterial Biofilm-Resistant Materials.

Presented in this work is the use of a molecular descriptor, termed the α parameter, to aid in the design of a series of novel, terpene-based, and sustainable polymers that were resistant to biofilm formation by the model bacterial pathogen . To achieve this, the potential of a range of recently reported, terpene-derived monomers to deliver biofilm resistance when polymerized was both predicted and ranked by the application of the α parameter to key features in their molecular structures. These monomers were derived from commercially available terpenes (, α-pinene, β-pinene, and carvone), and the prediction of the biofilm resistance properties of the resultant novel (meth)acrylate polymers was confirmed using a combination of high-throughput polymerization screening (in a microarray format) and testing.

Polyploidy increases storage but decreases structural stability in Arabidopsis thaliana.

Whole-genome duplication, leading to polyploidy and endopolyploidy, is widespread throughout the tree of life. Both polyploidy and endopolyploidy can increase cell size via nucleotypic effects, but the phenotypic consequences of increased cell size at the tissue and whole-organism levels are less well understood. We quantified the consequences of autopolyploidy and endopolyploidy in nine diploid accessions of Arabidopsis thaliana, representing a gradient in endopolyploidy, to their corresponding experimentally synthesized neo-tetraploid and neo-octoploid cytotypes.

Outbreak Associated with Pasteurized Milk.

In July 2019, we investigated a cluster of cases affecting a youth summer camp and nearby community in northeastern Pennsylvania. After initial telephone interviews with camp owners and community members, we identified pasteurized milk from a small dairy conducting on-site pasteurization, Dairy A, as a shared exposure. We conducted site visits at the camp and Dairy A where we collected milk and other samples.