Cardenolides in Seeds: Exploring the Legacy of Tadeus Reichstein.

The common milkweed is widespread in North America and produces cardenolide toxins that deter herbivores by targeting the transmembrane enzyme Na/K-ATPase. In 1979, Nobel Laureate Tadeus Reichstein elucidated the structure of novel cardenolides isolated from roots and proposed structures for several other cardenolides that could not be confirmed. In this study, we investigate the cardenolide composition of seeds, focusing on their abundance and inhibitory potency on the sensitive porcine Na/K-ATPase and that of the highly resistant large milkweed bug, .

Plant chemical diversity enhances defense against herbivory.

Multiple hypotheses have been put forth to understand why defense chemistry in individual plants is so diverse. A major challenge has been teasing apart the importance of concentration vs. composition of defense compounds and resolving the mechanisms of diversity effects that determine plant resistance against herbivores.

Long-living transients in ecological models: Recent progress, new challenges, and open questions.

Traditionally, mathematical models in ecology placed an emphasis on asymptotic, long-term dynamics. However, a large number of recent studies highlighted the importance of transient dynamics in ecological and eco-evolutionary systems, in particular 'long transients' that can last for hundreds of generations or even longer. Many models as well as empirical studies indicated that a system can function for a long time in a certain state or regime (a 'metastable regime') but later exhibits an abrupt transition to another regime not preceded by any parameter change (or following the change that occurred long before the transition).

Potent Nitrogen-containing Milkweed Toxins are Differentially Regulated by Soil Nitrogen and Herbivore-induced Defense.

Theories have been widely proposed and tested for impacts of soil nitrogen (N) on phytochemical defenses. Among the hundreds of distinct cardenolide toxins produced by milkweeds (Asclepias spp.), few contain N, yet these appear to be the most toxic against specialist herbivores.

Convergence and Divergence among Herbivorous Insects Specialized on Toxic Plants: Revealing Syndromes among the Cardenolide Feeders across the Insect Tree of Life.

AbstractRepeatable macroevolutionary patterns provide hope for rules in biology, especially when we can decipher the underlying mechanisms. Here we synthesize natural history, genetic adaptations, and toxin sequestration in herbivorous insects that specialize on plants with cardiac glycoside defenses. Work on the monarch butterfly provided a model for evolution of the "sequestering specialist syndrome," where specific amino acid substitutions in the insect's Na/K-ATPase are associated with (1) high toxin resistance (target site insensitivity [TSI]), (2) sequestration of toxins, and (3) aposematic coloration.

Rapid haemostasis to achieve dressing longevity: evaluation trial results using StatSeal catheter exit site protection.

Peripherally inserted central catheters (PICCs) are vital in delivering intravenous therapy. Despite their advantages, PICCs can lead to complications such as catheter exit site bleeding, which can cause patient distress and increase infection risk. This study evaluated the efficacy of StatSeal, a topical haemostatic device, in managing PICC exit site bleeding.

Short report: Integrated evaluations for autism spectrum disorder in pediatric primary care clinics.

Primary care providers often screen for autism during well child visits in the first few years of life and refer children for diagnostic evaluations when needed. However, most children do not receive a diagnosis until years later which delays access to services. Racism, socioeconomic status, and other systemic inequalities that limit access to health care further delay diagnostic evaluations.

When can higher-order interactions produce stable coexistence?

Most ecological models are based on the assumption that species interact in pairs. Diverse communities, however, can have higher-order interactions, in which two or more species jointly impact the growth of a third species. A pitfall of the common pairwise approach is that it misses the higher-order interactions potentially responsible for maintaining natural diversity.

Effect of migrations on synchrony in host-parasitoid system.

Insect outbreaks can cause large scale defoliation of forest trees or destruction of crops, leading to ecosystem degradation and economic losses. Some outbreaks occur simultaneously across large geographic scales and some outbreaks occur periodically every few years across space. Parasitoids are a natural enemy of these defoliators and could help mitigate these pest outbreaks.

Neuropathologic Validation and Diagnostic Accuracy of Presynaptic Dopaminergic Imaging in the Diagnosis of Parkinsonism.

Background And Objectives: Degeneration of the presynaptic nigrostriatal dopaminergic system is one of the main biological features of Parkinson disease (PD), multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD), which can be measured using single-photon emission CT imaging for diagnostic purposes. Despite its widespread use in clinical practice and research, the diagnostic properties of presynaptic nigrostriatal dopaminergic (DAT) imaging in parkinsonism have never been evaluated against the diagnostic gold standard of neuropathology. The aim of this study was to evaluate the diagnostic parameters of DAT imaging compared with pathologic diagnosis in patients with parkinsonism.

Low risk management intervention: Limited impact of remedial tillage on net ecosystem carbon balance at a commercial Miscanthus plantation.

Perennial bioenergy crops are a key tool in decarbonizing global energy systems, but to ensure the efficient use of land resources, it is essential that yields and crop longevity are maximized. Remedial shallow surface tillage is being explored in commercial Miscanthus plantations as an approach to reinvigorate older crops and to rectify poor establishment, improving yields. There are posited links, however, between tillage and losses in soil carbon (C) via increased ecosystem C fluxes to the atmosphere.

Landscape fragmentation overturns classical metapopulation thinking.

Habitat loss and isolation caused by landscape fragmentation represent a growing threat to global biodiversity. Existing theory suggests that the process will lead to a decline in metapopulation viability. However, since most metapopulation models are restricted to simple networks of discrete habitat patches, the effects of real landscape fragmentation, particularly in stochastic environments, are not well understood.

Preparation of monodisperse cerium oxide particle suspensions from a tetravalent precursor.

Cerium oxide particles are a unique material that enables studying the intersection of metal oxides, -elements, and nanomaterials. Distinct from diverse applications in catalysis, energy, and medicine, cerium possesses additional influence as a non-radioactive actinide surrogate. Herein, we present a synthesis for sub-micron cerium particles using hexamethylenetetramine and ammonium hydroxide as precipitating agents with a Ce precursor.

A model free method of predicting transient dynamics in anaerobic digestion.

Transient dynamics pose unique challenges when dealing with predictions and management of ecological systems yet little headway has been made on understanding when an ecological system might be in a transient state. As a start we consider a specific model, here focusing on a canonical model for anaerobic digestion. Through a series of simplifications, we analyse the potential of the model for transient dynamics, and the driving mechanisms.

Perennial biomass cropping and use: Shaping the policy ecosystem in European countries.

Demand for sustainably produced biomass is expected to increase with the need to provide renewable commodities, improve resource security and reduce greenhouse gas emissions in line with COP26 commitments. Studies have demonstrated additional environmental benefits of using perennial biomass crops (PBCs), when produced appropriately, as a feedstock for the growing bioeconomy, including utilisation for bioenergy (with or without carbon capture and storage). PBCs can potentially contribute to Common Agricultural Policy (CAP) (2023-27) objectives provided they are carefully integrated into farming systems and landscapes.

Novel Miscanthus hybrids: Modelling productivity on marginal land in Europe using dynamics of canopy development determined by light interception.

New biomass crop hybrids for bioeconomic expansion require yield projections to determine their potential for strategic land use planning in the face of global challenges. Our biomass growth simulation incorporates radiation interception and conversion efficiency. Models often use leaf area to predict interception which is demanding to determine accurately, so instead we use low-cost rapid light interception measurements using a simple laboratory-made line ceptometer and relate the dynamics of canopy closure to thermal time, and to measurements of biomass.

An approach to assessing subsea pipeline-associated mercury release into the North Sea and its potential environmental and human health impact.

Mercury is a naturally occurring heavy metal that has also been associated with anthropogenic sources such as cement production or hydrocarbon extraction. Mercury is a contaminant of concern as it can have a significant negative impact on organismal health when ingested. In aquatic environments, it bioaccumulates up the foodweb, where it then has the potential to impact human health.

Structural characterization of a new samarium-sodium heterometallic coordination polymer.

Lanthanide-containing materials are of inter-est in the field of crystal engin-eering because of their unique properties and distinct structure types. In this context, a new samarium-sodium heterometallic coordination polymer, poly[tetra-kis-(μ-2-formyl-6-meth-oxy-phenolato)samarium(III)sodium(I)], {[SmNa(CHO)]·solvent} (), was synthesized and crystallized slow evaporation from a mixture of ethanol and aceto-nitrile. The compound features alternating Sm and Na ions, which are linked by -vanillin (-vanillin) ligands to form a mono-periodic chain-like coordination polymer.

Variation in Avian Predation Pressure as a Driver for the Diversification of Periodical Cicada Broods.

AbstractPeriodical cicadas live 13 or 17 years underground as nymphs, then emerge in synchrony as adults to reproduce. Developmentally synchronized populations called broods rarely coexist, with one dominant brood locally excluding those that emerge in off years. Twelve modern 17-year cicada broods are believed to have descended from only three ancestral broods following the last glaciation.

Making Your Own Luck: Weak Vertical Swimming Improves Dispersal Success for Coastal Marine Larvae.

Dispersive early life stages are common in nature. Although many dispersing organisms ("propagules") are passively moved by outside forces, some improve their chances of successful dispersal through weak movements that exploit the structure of the environment to great effect. The larvae of many coastal marine invertebrates, for instance, swim vertically through the water column to exploit depth-varying currents, food abundance, and predation risk.

Rate-induced tipping in complex high-dimensional ecological networks.

In an ecosystem, environmental changes as a result of natural and human processes can cause some key parameters of the system to change with time. Depending on how fast such a parameter changes, a tipping point can occur. Existing works on rate-induced tipping, or R-tipping, offered a theoretical way to study this phenomenon but from a local dynamical point of view, revealing, e.