Exploring Functional Transitions of the 2’-dG Riboswitch Aptamer
Researchers introduced an explicit‑electrostatics RNA‑structure‑based model (SBM) that enables all‑atom‑like molecular dynamics of the 2′‑dG riboswitch over biologically relevant timescales. Simulations reveal that Mg²⁺ ions and temperature reshape the folding energy landscape, stabilizing the regulatory P1 helix in the ligand‑bound (holo) state while leaving it flexible when unbound. The study identifies a multibasin free‑energy profile where secondary structures persist but tertiary contacts reorganize depending on ligand presence. Results align with SHAPE, NMR, and explicit‑solvent data, validating the coarse‑grained approach.
Profile of Helen M. Piwnica-Worms
Helen M. Piwnica‑Worms, a veteran cancer biologist, has spent decades dissecting how tumor cells bypass cell‑cycle checkpoints and develop drug resistance. Her early work clarified the role of tyrosine phosphorylation in src and cdc2 regulation, laying groundwork for modern checkpoint...
The Latino Health Experience: Past and Future
A new PNAS review by Goldman and Pebley examines the Latino health paradox, highlighting the group’s historically higher life expectancy alongside persistent chronic disease, disability, and occupational risks. The authors document how COVID‑19 sharply reduced Latino survival, exposing socioeconomic and...
In This Issue
The latest issue presents three breakthrough studies: a genome‑wide analysis reveals a sweeping genetic replacement in Neanderthals, reshaping our view of their demographic history; researchers identify “hasslers” – toxic close contacts – as accelerators of biological aging using DNA‑methylation clocks;...
Spider Venom Phospholipase D Toxin Structure: Interfacial Binding Site, Mechanism, Activation, and Head Group Preference
Researchers solved crystal structures of a phospholipase D toxin from the Chilean six‑eyed sand spider at 1.85‑2.6 Å resolution, capturing the enzyme bound to a micelle‑like assembly of sphingolipid substrates and products. The structures reveal the active‑site geometry, an interfacial binding site...
Toward the Simultaneous Detection of Multiple Diseases with a Highly Cost-Effective Cell-Free DNA Methylome Test
Researchers introduced MethylScan, a low‑cost cell‑free DNA methylome sequencing assay that profiles the entire cfDNA methylome from a single blood draw. In a cohort of 1,061 individuals, the test achieved an AUROC of 0.938 for multicancer detection (63.3% sensitivity at...
Hydraulic Stress Limits Thermal Acclimation in Trees Under Chronic Drought
A five‑year field experiment on European beech (Fagus sylvatica) and downy oak (Quercus pubescens) shows that trees can acclimate leaf cooling when temperatures rise but water is plentiful. When chronic soil‑moisture deficit is added, hydraulic safety margins shrink, stomata close,...
Reefense: Living Shoreline Mosaics Can Achieve Ecological and Engineering Outcomes with Interdisciplinary Design
A new interdisciplinary effort, dubbed Reefense, demonstrates that living shoreline mosaics—particularly oyster‑reef based designs—can deliver both coastal protection and ecosystem benefits. The research, funded by DARPA, shows that a stable substrate can provide immediate wave attenuation while the maturing reef...
Training Thermodynamic Computers by Gradient Descent
The paper introduces a gradient‑descent training framework for thermodynamic computers, allowing them to execute neural‑network‑style computations with dramatically lower energy use. By maximizing the probability of an idealized trajectory that mimics a trained neural network, the authors align the physical...
Lone Black Holes Promise Fresh Insights Into the Fates of Massive Stars
Astronomers have confirmed several isolated, stellar‑mass black holes using astrometric microlensing, most notably OG 2011‑BLG‑0462, which recent Hubble Space Telescope data validates. These lone black holes, detected without companion stars, fill the long‑standing “mass gap” between neutron stars and typical black...
In This Issue
The latest issue presents three interdisciplinary studies: a genomic analysis reveals a widespread genetic replacement in Neanderthal populations across Europe, challenging earlier notions of continuity; an experimental investigation of GPT‑4 in mathematics education shows significant productivity gains but raises questions...
Nanoscale Infrared Spectroscopy Reveals Complex Organic–Mineral Assemblages in Asteroid Bennu
Researchers used nanoscale infrared (nano‑FTIR) and Raman spectroscopy on OSIRIS‑REx sample OREX‑800066‑3 to map chemical variability at ~20 nm resolution. The analysis identified three recurring domains—aliphatic‑rich, carbonate‑rich, and nitrogen‑bearing organic‑rich—each spatially distinct. Organosulfur species were confined to carbonate‑rich zones, indicating late‑stage...
The Low-Density Lipoprotein Receptor LDLR Mediates Cellular Entry of Nonenveloped Hepatitis A Virus
Researchers have identified the low‑density lipoprotein receptor (LDLR) as the primary cellular entry factor for nonenveloped hepatitis A virus (nHAV). LDLR binds the capsid near its fivefold vertex, directing the virus into clathrin‑dependent endosomes where it encounters ganglioside receptors. Knockout of...