Rayleigh-Taylor Instability in a Relativistic Shock

The hierarchy between the mass parameter of the Higgs boson and larger mass scales becomes ever more puzzling as experiments explore higher energies. Neutral naturalness is the umbrella term for symmetry-based explanations for these hierarchies whose quark symmetry partners are not charged under the SU(3)

 color gauge group of the Standard Model. Though the first manifestations of this idea predate the physics runs of the Large Hadron Collider, since the Higgs discovery this paradigm has grown and developed to include a wide variety of concrete realizations with connections to intriguing collider signals. Determining the phenomenology of such models often requires the characterization—typically relying on lattice calculations—of a new confining gauge symmetry. This presents additional motivation to further develop our understanding of nonperturbative field theory as well as to pursue specific lattice studies. The wide range of suggested hidden sectors also produces a variety of dark matter candidates, intersections with astrophysics and cosmology, and ties to neutrinos and flavor. In this review, we orient the reader within both this growing collection of specific models and the physical phenomena they produce. We also survey the often less familiar dynamics of hidden-sector glueballs and quirks. In addition to providing a guide to past efforts, we reveal interesting directions for further study.

Searching for life elsewhere in the universe is one of the most highly prioritized pursuits in astronomy today. However, the ability to observe evidence of Earth-like life through biosignatures is limited by the number of planets in the solar neighborhood with conditions similar to Earth. The occurrence rate of Earth-like planets in the habitable zones of Sun-like stars, η⊕, is therefore crucial for addressing the apparent lack of consensus on its value in the literature. Here we present a review of the current understanding of η⊕. We first provide definitions for parameters that contribute to η⊕. Then, we discuss the previous and current estimated parameter values and the context of the limitations on the analyses that produced these estimates. We compile an extensive list of the factors that go into any calculation of η⊕, and how detection techniques and surveys differ in their sensitivity and ability to accurately constrain η⊕. Understanding and refining the value of η⊕ is crucial for upcoming missions and telescopes, such as the planned Habitable Worlds Observatory and the Large Interferometer for Exoplanets, which aim to search for biosignatures on exoplanets in the solar neighborhood.

Time reversal (TR) is a technique used to focus wave energy to a selected location. High energy TR focusing has application in biomedical ultrasound and nondestructive evaluation of cracks or defects in solids. These applications can benefit from having the narrowest possible spatial extent of the focused sound energy, which is normally diffraction limited. Two-dimensional Helmholtz resonator arrays placed in the near field of TR focusing have been shown to produce a sub-diffraction limited spatial extent of the focused energy (when compared to the free-space wavelength). There is an apparent amplitude dependence to this focusing and this paper will discuss these nonlinear aspects. These observations were made by analyzing experimental results of TR focusing among an array of empty soda cans at different sound excitation levels. These nonlinear effects occur at much lower sound levels than is typical for nonlinear waveform steepening. The conclusion is made that the nonlinear observations are acoustic nonlinearities and are likely caused by acoustic jetting in Helmholtz resonators and this principally causes the amplitude of the focusing to be as much as three times lower in amplitude than linear scaling would predict and causes the spatial extent of the focusing to increase somewhat.

Artificial intelligence (AI)-based prostate cancer detection through whole slide images (WSIs) offers promising potential to address the global pathologist shortage while improving clinical consistency. Digital slides and improving image analysis methods encourage the creation of tools to aid in WSI classification. Despite promising advances, these tools are still limited by available training data. Current publicly available datasets, such as Kaggle's PANDA Challenge, while large in scale, rely on slide-level labels that may introduce noise and limit model reliability. Others contain detailed annotations, but are smaller in size due to manual processing efforts. In this work, we introduce PANDA-PLUS, a 546-image dataset derived from PANDA images with improved pixel-level annotations, as well as an accompanying annotation pipeline that reduces pathologists' time commitment. We present a detailed comparative analysis between PANDA-PLUS and PANDA using Gleason score and ISUP grade, supported by agreement values, κ, and PABAK under multiple weighting schemes. The results demonstrate consistently lower grading in PANDA-PLUS, with disagreement patterns especially pronounced at higher grades. We also demonstrate through single rater grading of various annotation granularities how slide- and patch-level labels may distort grading proportions and alter image scores. PANDA-PLUS not only improves annotation granularity and reduces label noise but also exposes potential grading errors in the original PANDA dataset. We present PANDA-PLUS's annotations as an improved alternative to the PANDA labels and conclude that it represents a step forward in the development of higher-quality public datasets for clinical AI applications in prostate cancer pathology.

We present medium-resolution near-infrared spectral measurements of the carbon monoxide (CO) and the cyano radical (CN) features in 12 Galactic classical Cepheids. The pulsation periods of our sample range from 5.5 to 69 d, and the stars studied each had five or more near-IR spectral observations. The CO and CN measurements were used to probe CNO abundances of these stars, and elemental abundance values from the literature were used to identify the trends of [C/N] and [O/N] with CN and CO. To put these measurements in context, we performed stellar atmosphere fitting to obtain estimates of stellar parameters, with a primary focus on effective temperature. Our measurements and temperature estimates show that CN is significantly affected by dredge-up of processed material. We provide discussion as to the potential nature of the recently confirmed classical Cepheid, ET Vul, and connect our near-infrared CO measurements to the mid-infrared period–colour–metallicity relation.

The glomerular filtration barrier poses a significant challenge for circulating proteins, with molecules below ~60–70 kDa facing rapid renal clearance. Endogenous proteins have evolved sophisticated evasion mechanisms including oligomerization, carrier binding, electrostatic repulsion, and FcRn-mediated recycling. Understanding these natural strategies provides blueprints for engineering therapeutic proteins with improved pharmacokinetics. This review examines how endogenous proteins resist filtration, evaluates their application in protein engineering, and discusses clinical translation including established technologies (PEGylation, Fc-fusion) and emerging strategies (albumin-binding domains, glycoengineering). We address critical challenges of balancing half-life extension with tissue penetration, biological activity, and immunogenicity—essential considerations for the rational design of next-generation therapeutics with optimized dosing and enhanced efficacy.