Perineuronal nets in motor circuitry regulate the performance of learned vocalizations in songbirds.

The accurate and reliable performance of learned vocalizations (e.g., speech and birdsong) modulates the efficacy of communication in humans and songbirds.

Medical Student Evaluations of Medical Faculty: Characteristics of Highly and Lower-Rated Teachers.

Purpose: Our purpose was to evaluate the characteristics of highly and poorly rated teachers as well as to assess the validity and reliability of those evaluations.

Methods: We downloaded 14 years of medicine faculty evaluations completed by 3rd and 4 year medical students. We dichotomized overall teaching effectiveness as outstanding (receiving "outstanding") or inferior (rated as a "unsatisfactory," "marginal," or "acceptable").

The Equilibrium Theory of Biodiversity Dynamics: A General Framework for Scaling Species Richness and Community Abundance along Environmental Gradients.

AbstractLarge-scale temporal and spatial biodiversity patterns have traditionally been explained by multitudinous particular factors and a few theories. However, these theories lack sufficient generality and do not address fundamental interrelationships and coupled dynamics among resource availability, community abundance, and species richness. We propose the equilibrium theory of biodiversity dynamics (ETBD) to address these linkages.

Tracking gonadal development in fish: An in vivo MRI study on polar cod, Boreogadus saida (Lepechin, 1774).

Magnetic resonance imaging (MRI) was applied to determine the sex of polar cod (Boreogadus saida Lepechin, 1774) (Actinopterygii: Gadidae) and to follow the gonadal development in individual animals over time. Individual unanaesthetised fish were transferred to a measurement chamber inside a preclinical 9.4 T MRI scanner and continuously perfused with aerated seawater.

Mathematical biases in the calculation of the Living Planet Index lead to overestimation of vertebrate population decline.

The Living Planet Index (LPI) measures the average change in population size of vertebrate species over recent decades and has been repeatedly used to assess the changing state of nature. The LPI indicates that vertebrate populations have decreased by almost 70% over the last 50 years. This is in striking contrast with current studies based on the same population time series data that show that increasing and decreasing populations are balanced on average.