Proceedings of the National Academy of Sciences (PNAS)

Energy costs of Hannibal’s alpine crossing

Hannibal crossed the Alps with a large army containing 37 war elephants in 218 BC. Details of his route have scholars ...
PNAS

Mastering the interface for advanced all-solid-state lithium rechargeable batteries

Contributed by John B. Goodenough, September 30, 2016 (sent for review August 24, 2016; reviewed by Ken Poeppelmeier and Jean-Marie Tarascon) ...
PNAS

Metabolic breadth links insect pathogenicity and plant association in Metarhizium robertsii

Fungi often transition between ecological roles, acting as pathogens, symbionts, and decomposers, yet the mechanisms enabling such lifestyle flexibility remain unclear. By comparing early and recently ...
PNAS

Hamiltonian Systems and Transformation in Hilbert Space

Hamiltonian Systems and Transformation in Hilbert Space For more than 40 y, entomologists have attempted to estimate the number of insect species on Earth, with the current consensus—the figure most ...
PNAS

Editorial and Journal Policies

The PNAS Editorial Board is made up of NAS members who are active scientists and experts in their fields. On submission, your paper is assigned to an Editorial Board member in one of the 31 NAS ...
PNAS

Extremism does not stop at borders, and neither should our models

The Democracy Index finding holds up best. Its negative direct effect on offensive VEI (we use β for SDM coefficients throughout) survives spatial adjustment in every bivariate specification (Table 1) ...
PNAS

Assembling the mitochondrial ATP synthase

Assembling the mitochondrial ATP synthase The assembly of the mitochondrial ATP synthase is a complicated process that involves the coordinated association of mitochondrially and nuclear encoded ...
PNAS

Peopling of the Americas

PNAS: Welcome to Science Sessions, the podcast of the Proceedings of the National Academy of Sciences, where we connect you with Academy members, researchers, and policymakers. Join us as we explore ...
PNAS

Full solid-state magnetic refrigeration device toward thermal management

For practical purposes, utilizing high thermal conductivity materials (HTCMs) to implement regeneration is a promising alternative to attempts of pursuing an ideal thermal diode, while they still ...
PNAS

The skeleton of tropical intraseasonal oscillations

Although theory and simulation of the MJO remain difficult challenges, they are guided by the generally accepted, fundamental features of the MJO (i.e., the MJO's “skeleton”) on ...
PNAS

Genomic insights that advance the species definition for prokaryotes

To help advance the species definition for prokaryotes, we have compared the gene content of 70 closely related and fully sequenced bacterial genomes to identify whether species boundaries exist, and ...
PNAS

The average distances in random graphs with given expected degrees

Most of the research papers in random graph theory concern the Erdős–Rényi model 𝒢p, in which each edge is independently chosen with probability p for some given p > 0 (see ref. 3). In such random ...