A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.

A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.

New measurements test a decades-old hypothesis about the proton's identity.

Mitotic chromosome size and shape are influenced by conditions that control ionic hydrogels.

The fossil record attributes shark decline in the Caribbean to human activity.

Chemical inhibition of Plasmodium plasmepsin proteins offers a new path for drug-based malaria vaccination.

Long-sought particle, made of force-carrying gluons, represents a new type of matter.

Studies probe the limits of new sodium channel blockers.

Opinions shift after new data suggest vaccine for Ebola Zaire may also protect against Bundibugyo.

The feedback between competition and evolution is central to hypotheses about the origin and maintenance of species diversity. Yet, whether competition-induced evolution is sufficiently rapid, consistent, and strong to maintain diversity on ecological timescales remains unresolved. We conducted an outdoor mesocosm experiment with four pairs of orchard fly species in which we manipulated species' ability to evolve to one another during interspecific competition. We found significant competition-induced rapid evolution across phenotypes, which typically shifted in parallel across species. This evolution strongly affected the competitive population dynamics of all species pairs, typically boosting the rarer species' abundance, and in one pair, reversing the abundance hierarchy. These results suggest that feedback between competition and evolution may be common and maintain species diversity on ecological timescales.

After a record-low snowpack, federal authorities canceled dam releases for managing fish and sandbars.

The formation of metaphase chromosomes requires the activity of condensins, DNA translocases that reduce chromosomal length through the process of loop extrusion. Reduction of length, however, does not account for the increase in density of chromatin in condensed states. Here, we show that eukaryotic chromosomes are ionic hydrogels and that the chromosomal material is a two-state system, with interconversion between condensed and decondensed states through a volume phase transition, analogous to a liquid-gas transition. Ionic contacts between histone tails and DNA, formed and broken by histone acetylation and deacetylation, may control the transition and be responsible for condensation in heterochromatin and decondensation in euchromatin.

Study of mitochondria suggests new treatment strategy for Alzheimer's and other diseases.

Uncertainty remains regarding the impact of rapid anthropogenic warming on forest ecosystem structure, biodiversity, and function. As an analog, we reconstruct forest canopy density and compositional change in Wyoming, USA, through the Paleocene-Eocene Thermal Maximum (PETM), an interval of abrupt carbon increase and warming ~56 million years ago. We develop a proxy to quantify leaf area index and assess shifts in floral composition using palynomorphs. Forest canopies opened abruptly at onset of PETM warming, landscape erosion increased, and vegetation shifted from broad-leaved angiosperm to fern- and palm-dominated ecosystems. When combined with regional data, these patterns suggest that continental-scale changes in plant communities cause landscape destabilization. These shifts also have implications for multimillennial-scale hydrologic and carbon cycle feedbacks in the climate system.