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Abstract Environmental change can impact host–parasite interactions, but the effects of multiple stressors on parasites are rarely measured. Considering stressor interactions may allow parasitologists to evaluate how parasite burdens change in nature, where stressors rarely occur in isolation. This study aimed to understand how combined stressors such as warming, nutrients and pollution (i.e. metal concentrations) influence myxozoan prevalence and abundance in the Pearl River, Louisiana, USA. Fish were seined between 1963 and 2005 upstream and downstream of a pulp-mill outfall and were then preserved and accessioned into the Royal D. Suttkus Fish Collection of the Tulane University Biodiversity Research Institute. In 2024, we dissected 1188 fish individuals across 7 host species, and we identified myxozoans in 6 species. Six myxozoan genera were detected, includingChloromyxum, Henneguya, Myxidium, Myxobolus, ThelohanellusandUnicauda, with some novel host–parasite combinations. The abundance ofMyxobolusinfectingCarpiodes velifergills declined by 86% over the study period, while the abundance ofMyxobolusinfectingPimephales vigilaxgills was significantly lower downstream of the pulp mill outfall. Among the drivers analyzed, temperature had a significant negative effect on this parasite’s abundance, metal concentrations had a positive effect, and these 2 drivers interacted. Our results highlight the differential susceptibility of wild fishes to myxozoan infections and the usefulness of museum collections for understanding historical change in myxozoan burdens in fish. Since stressor-driven changes in myxozoan abundance do not follow a single pattern across species, we expect a shift in freshwater myxozoan communities with progressing climate change and pollution. 

Abstract ObjectivesThe aim of this research is to develop an understanding of the potential for using recycled glass sand as a resource for restoring Louisiana's coastline by testing the effects of exposure of native estuarine fauna to recycled glass sand and other sand treatments in a laboratory environment. MethodsFive species native to Louisiana estuaries were exposed to six different sediment treatments, including two recycled glass sand treatments, for 30–38 days over a period from June 2022 to January 2023. The tested species were Atlantic croaker (Micropogonias undulatus), Gulf Killifish (Fundulus grandis), Blue Crab (Callinectes sapidus), White Barnacle (Semibalanus balanoides), and Eastern Oyster (Crassostrea virginica). The six treatments were: Mississippi river dredge (natural sand); Quickcrete Play Sand; Fairmount‐Santrol Aquaquartz; Glass Half Full (GHF) L5 fine grain recycled glass sand, a custom‐made mix of 50% Mississippi river dredge, 25% each of two coarse recycled glass sands (GHF L3 and GHF L4); and a control treatment of no sediment. Each animal was housed individually or in pairs based on species, and received feeding and wellness checks daily. After approximately 30 days, all survivors were euthanized and survivorship for each group was calculated. ResultsThe results of the exposure experiments varied slightly among species, but overall survivorship was high and did not differ significantly among treatments. We observed little to no lethal effects of exposure of native estuarine fauna to recycled glass sand, or any of the other sand treatments we tested. ConclusionOur results suggest that recycled glass sand can be used in coastal restoration. 

ABSTRACT Bottlebrush (BB) polymers with polydimethylsiloxane (PDMS) side‐chains exhibit supersoft moduli (E < 100 kPa) without solvent, making them promising tissue‐mimetic materials for biomedical applications. While larger backbones and side‐chains enhance softness, synthetic limitations have constrained their molecular weight. We report a graft‐through method to access ultra‐high molecular weight PDMS BB polymers (~1–20 million g mol⁻¹). Central to this was the design of a norbornene‐pyrrolidine aryllithium initiator for the anionic ring‐opening of hexamethylcyclotrisiloxane (D3), yielding monofunctionalized PDMS macromonomers (MMs) with molecular weights from 1–30 kg mol⁻¹. Subsequent ring‐opening metathesis polymerization (ROMP) produced BB homopolymers within minutes (t ≤ 5 min) and with low dispersity (Đ < 1.3). The ‐C‐Si‐O‐ linkage between the backbone and side‐chains provided improved chemical stability over earlier ‐C‐O‐Si‐ analogues. These MMs were also used to create a linear‐bottlebrush‐linear block copolymer, forming a supersoft (E = 79 kPa), thermoplastic elastomer with excellent elastic recovery (~96%). This platform enables the synthesis of ultra‐high molecular weight graft (co‐)polymers, advancing the study of extreme structure–property relationships and supporting the development of novel soft materials for bio‐interfacing. 

With over 6 million tons produced annually, thermoplastic elastomers (TPEs) have become ubiquitous in modern society, due to their unique combination of elasticity, toughness, and reprocessability. Nevertheless, industrial TPEs display a tradeoff between softness and strength, along with low upper service temperatures, typically ≤100 °C. This limits their utility, such as in bio‐interfacial applications where supersoft deformation is required in tandem with strength, in addition to applications that require thermal stability (e.g., encapsulation of electronics, seals/joints for aeronautics, protective clothing for firefighting, and biomedical devices that can be subjected to steam sterilization). Thus, combining softness, strength, and high thermal resistance into a single versatile TPE has remained an unmet opportunity. Through de novo design and synthesis of novel norbornene‐basedABAtriblock copolymers, this gap is filled. Ring‐opening metathesis polymerization is employed to prepare TPEs with an unprecedented combination of properties, including skin‐like moduli (<100 kPa), strength competitive with commercial TPEs (>5 MPa), and upper service temperatures akin to high‐performance plastics (≈260 °C). Furthermore, the materials are elastic, tough, reprocessable, and shelf stable (≥2 months) without incorporation of plasticizer. Structure–property relationships identified herein inform development of next‐generation TPEs that are both biologically soft yet thermomechanically durable. 

ABSTRACT Ring‐opening metathesis polymerization (ROMP) offers a rapid, mild, and controlled route to prepare block copolymers via sequential monomer addition, where the number of blocks equates to the number of additions. However, block extension is hampered once control is lost, which can occur from cross‐metathesis and polymer precipitation during growth, precluding the ability to make certain functional triblock copolymers via unidirectional chain‐growth. Middle‐out growth from a bifunctional initiator cuts the number of additions in ~half, which has been extensively leveraged for controlled radical polymerizations but remains scarce for ROMP. Herein, a novel bifunctional Hoveyda‐Grubbs type ruthenium‐alkylidene initiator is presented and systematically examined for its use in ROMP of cyclic olefin monomers. The initiator is air‐stable, provides polymers with narrow molecular weight distributions (Đ < 1.20) and enables the preparation of functional ABA triblock and ABABA pentablock copolymers. Exemplars include norbornene‐based thermoplastic elastomers that are soft yet strong, and those that contain outer blocks from low ring strain cyclic olefins, namelycis‐cyclooctene to form poly(cyclooctene) that readily undergoes cross‐metathesis and cyclooctatetraene to form (semi)conductive yet poorly soluble poly(acetylene). This platform represents a valuable synthetic tool for the rapid generation of functional block copolymers with potential applications in soft robotics and electronics. 

Let P(k) denote the largest size of a non-collinear point set in the plane admitting at most k distinct angles. We prove P(2) = P(3) = 5, and we characterize the optimal sets. We also leverage results from Fleischmann et al. [Disc. Comput. Geom. (2023)] to provide the general bounds k+2 ≤ P(k) ≤ 6k, although the upper bound may be improved pending progress toward the Strong Dirac Conjecture. We conjecture that the lower bound is tight, providing infinite families of configurations meeting the bound and ruling out several classes of potential counterexamples. 

Abstract Image‐based machine learning tools are an ascendant ‘big data’ research avenue. Citizen science platforms, like iNaturalist, and museum‐led initiatives provide researchers with an abundance of data and knowledge to extract. These include extraction of metadata, species identification, and phenomic data. Ecological and evolutionary biologists are increasingly using complex, multi‐step processes on data. These processes often include machine learning techniques, often built by others, that are difficult to reuse by other members in a collaboration.We present a conceptual workflow model for machine learning applications using image data to extract biological knowledge in the emerging field of imageomics. We derive an implementation of this conceptual workflow for a specific imageomics application that adheres to FAIR principles as a formal workflow definition that allows fully automated and reproducible execution, and consists of reusable workflow components.We outline technologies and best practices for creating an automated, reusable and modular workflow, and we show how they promote the reuse of machine learning models and their adaptation for new research questions. This conceptual workflow can be adapted: it can be semi‐automated, contain different components than those presented here, or have parallel components for comparative studies.We encourage researchers—both computer scientists and biologists—to build upon this conceptual workflow that combines machine learning tools on image data to answer novel scientific questions in their respective fields. 

Abstract The conference “Transposable Elements at the Crossroads of Evolution, Health and Disease” was hosted by Keystone Symposia in Whistler, British Columbia, Canada, on September 3–6, 2023, and was organized by Kathleen Burns, Harmit Malik and Irina Arkhipova. The central theme of the meeting was the incredible diversity of ways in which transposable elements (TEs) interact with the host, from disrupting the existing genes and pathways to creating novel gene products and expression patterns, enhancing the repertoire of host functions, and ultimately driving host evolution. The meeting was organized into six plenary sessions and two afternoon workshops with a total of 50 invited and contributed talks, two poster sessions, and a career roundtable. The topics ranged from TE roles in normal and pathological processes to restricting and harnessing TE activity based on mechanistic insights gained from genetic, structural, and biochemical studies.