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Monitoring diseases within tree canopies is challenging due to their inaccessibility and the complexity of canopy ecosystems. Here, we explore the potential of stemflow sampling as a novel, ground-based method for detecting and monitoring canopy-associated pathogens. In a case study focused on Litylenchus crenatae ssp. mccannii (LCM), the nematode associated with Beech Leaf Disease (BLD), we collected stemflow samples from 18 Fagus grandifolia Ehrh. (American beech) trees across 12 storm events. eDNA assays detected LCM presence in 7 of those storms, with quantitative PCR-derived gene concentrations ranging from 80 to 158,000 copies mL−1. Higher detections and concentrations coincided with leaf senescence and bud formation periods, and they correlated conditionally with event rainfall amount and pre-storm changes in relative humidity. Although based on a single site and season, these findings demonstrate the potential for stemflow sampling to capture a pathogen’s eDNA (i.e., canopy distress signals) at ground level. This method could complement traditional monitoring, offering another affordable, non-invasive tool for pathogen detection. Additional validation, particularly regarding live versus dead organisms and across varied site conditions, will be essential to evaluate the breadth of value stemflow eDNA offers for canopy disease management and ecological research. 

Plasmonic nanoparticles with chiral resonances in the visible wavelengths complement optical dissymmetry in the ultraviolet and near-infrared wavelengths in natural products and metamaterials respectively. Here, we show that under oxidative conditions, hot holes photogenerated with circularly polarized light in gold nanoprisms can spatially direct the photodeposition of lead oxide (PbO2), resulting in chiral nanostructures tunable with the polarization and wavelength of light. We observe a g-factor of 3.6 × 10–3, which can be attributed to the enhanced optical dissymmetry with PbO2 deposition of the side of nanoprisms upon illumination with green 532 nm light. Our finite-difference time-domain calculations support the site-specific photodeposition of PbO2 onto nanoprisms. This work shows that plasmonic nanoparticles can have tunable chiral properties imbued as a function of the wavelength and polarization of light. 

Double electron−electron resonance (DEER) spectroscopy measures distance distributions between spin labels in proteins, yielding important structural and energetic information about conformational landscapes. Analysis of an experimental DEER signal in terms of a distance distribution is a nontrivial task due to the ill-posed nature of the underlying mathematical inversion problem. This work introduces a Bayesian probabilistic inference approach to analyze DEER data, assuming a nonparametric distance distribution with a Tikhonov smoothness prior. The method uses Markov Chain Monte Carlo sampling with a compositional Gibbs sampler to determine a posterior probability distribution over the entire parameter space, including the distance distribution, given an experimental data set. This posterior contains all of the information available from the data, including a full quantification of the uncertainty about the model parameters. The corresponding uncertainty about the distance distribution is visually captured via an ensemble of posterior predictive distributions. Several examples are presented to illustrate the method. Compared with bootstrapping, it performs faster and provides slightly larger uncertainty intervals. 

Primordial black holes (PBHs) remain a viable dark matter candidate in the asteroid-mass range. We point out that, in this scenario, the PBH abundance would be large enough for at least one object to cross through the inner Solar System per decade. Since Solar System ephemerides are modeled and measured to extremely high precision, such close encounters could produce detectable perturbations to orbital trajectories with characteristic features. We evaluate this possibility with a suite of simple Solar System simulations, and we argue that the abundance of asteroid-mass PBHs can plausibly be probed by existing and near-future data.