Contents
Vol 307, Issue 5710
Contents
This Week in Science
Editorial
Editors' Choice
NetWatch
Departments
Products & Materials
News of the Week
ScienceScope
Random Samples
News Focus
Letters
Books
Essays on Science and Society
Perspectives
Brevia
- Simple Foraminifera Flourish at the Ocean's Deepest Point
Newly described species of tubular and round protists that thrive at depths of 10 kilometers in Pacific trenches lack calcified walls and resemble early evolutionary forms.
Research Articles
- Crystal Structure of a Complex Between the Catalytic and Regulatory (RIα) Subunits of PKA
The structure of protein kinase C shows that cyclic AMP activates the enzyme by substituting for two amino acids of the catalytic subunit and displacing the inhibitory subunit.
- Saturn's Temperature Field from High-Resolution Middle-Infrared Imaging
High atmospheric temperatures near Saturn’s south pole, imaged from the Keck I Telescope, probably reflect the 15-year summer in the southern hemisphere.
Reports
- Rapid Formation of Sulfuric Acid Particles at Near-Atmospheric Conditions
Experiments show that sulfuric acid and water can react without ammonia to form new particles at a rate high enough to explain their natural atmospheric abundance.
- Dislocations in Complex Materials
High-resolution transmission electron microscopy confirms that many common materials deform in a complex manner by propagation of partial dislocations along two or more planes.
- End States in One-Dimensional Atom Chains
Atoms at the ends of a single-atom-wide gold chain on a silicon surface have distinctive electronic states that favorably lower energy levels within the chains.
- Photic Zone Euxinia During the Permian-Triassic Superanoxic Event
Organic compounds and sulfur isotopes found at the Permian-Triassic boundary in Australia and China imply that oxygen was depleted in the upper ocean at that time.
- Abrupt and Gradual Extinction Among Late Permian Land Vertebrates in the Karoo Basin, South Africa
Correlation of sections in the Karoo Basin imply a period of enhanced vertebrate extinction before the end-Permian catastrophe, and some replacement by Triassic species.
- Aconitase Couples Metabolic Regulation to Mitochondrial DNA Maintenance
One of the proteins that packages mitochondrial DNA is a well-known metabolic enzyme, linking energy metabolism and mitochondrial DNA stability.
- Natural Selection and Developmental Constraints in the Evolution of Allometries
Artificial selection readily changes the ratio of body size to wing size in butterflies, indicating that the relative sizes of body parts are shaped by selection, not developmental constraints.
- Mechanisms of Hair Graying: Incomplete Melanocyte Stem Cell Maintenance in the Niche
Hair turns gray when stem cells in the hair follicle can no longer replenish the supply of pigment-producing cells.
- Dynamic Complex Formation During the Yeast Cell Cycle
Only two-thirds of the proteins involved in cell division are transcribed in a periodic fashion, but these form cell cycle protein complexes and confer periodic function to the ensemble
- Escape of Intracellular Shigella from Autophagy
Harmful bacteria disguise their identity by coating telltale surface proteins with other proteins, thereby escaping digestion by the cells they invade.
- Nod2-Dependent Regulation of Innate and Adaptive Immunity in the Intestinal Tract
Mice lacking a gene associated with human Crohn's disease succumb to intestinal infection because they have lower concentrations of antimicrobial peptides in their gut.
- The Kaposin B Protein of KSHV Activates the p38/MK2 Pathway and Stabilizes Cytokine mRNAs
A protein from the herpesvirus that causes Kaposi's sarcoma exacerbates the disease by inhibiting degradation of cytokine mRNAs in the host, increasing inflammation.
- Mutualistic Fungi Control Crop Diversity in Fungus-Growing Ants
Fungal strains farmed by ant colonies maintain exclusivity by producing compounds that, when eaten by the ants and deposited in their manure, exclude competing fungal strains.
Technical Comments