Contents
Vol 310, Issue 5756
Special Issue
Breakthrough of the Year
News
BREAKTHROUGH OF THE YEAR
Contents
This Week in Science
Editorial
Editors' Choice
NetWatch
Products & Materials
News of the Week
ScienceScope
Random Samples
News Focus
Letters
Books
Policy Forum
Perspectives
Association Affairs
Review
Brevia
- Torus-Margo Pits Help Conifers Compete with Angiosperms
The success of conifer trees is partly a result of specialized pits in the ends of water-conducting cells that allow efficient fluid transport equal to that of angiosperms.
Research Articles
- Radar Soundings of the Subsurface of Mars
Mars Express radar data reveal that 2 kilometers of layered deposits rich in pure water ice underlie the North Polar Cap, but their weight barely deforms the underlying crust.
- Radar Soundings of the Ionosphere of Mars
Radar observations from Mars Express map the bulging of the Martian ionosphere in areas where the magnetic field in Mars' crust is oriented vertically.
- Animal Evolution and the Molecular Signature of Radiations Compressed in Time
New sequences of 50 genes from 17 taxa successfully resolve fungal evolution, but not animal evolution, because animals evolved in a series of closely spaced steps in deep time.
Reports
- Separation and Conversion Dynamics of Four Nuclear Spin Isomers of Ethylene
Among the four discrete nuclear spin isomers of ethylene, interconversion can occur among pairs of like-symmetry, qualifying the abundances of these isomers in space.
- Synthesis of Imido Analogs of the Uranyl Ion
The two oxygens that form double bonds to uranium in a common compound can be replaced with nitrogen groups, shedding light on the nature of bonding in actinide metals.
- Trading Water for Carbon with Biological Carbon Sequestration
Data and modeling imply that the use of large tree plantations to sequester atmospheric carbon dioxide will tax water supplies and degrade soils in many parts of the United States.
- Heterogeneous Hadean Hafnium: Evidence of Continental Crust at 4.4 to 4.5 Ga
Isotopic data from more than 100 of Earth's oldest preserved minerals imply that Earth had significant continental crust by 4.3 and perhaps as early as 4.5 billion years ago.
- X-ray Structure of the EmrE Multidrug Transporter in Complex with a Substrate
A membrane protein that transports drugs out of bacteria is an antiparallel dimer, with asymmetry between the two subunits driving unidirectional transport.
- A Developmental Timing MicroRNA and Its Target Regulate Life Span in C. elegans
In the nematode, a known RNA regulator that synchronizes development also controls life span through an insulin signaling pathway, suggesting a biological clock for aging.
- fgf20 Is Essential for Initiating Zebrafish Fin Regeneration
A newly described growth factor controls the earliest stages of limb regeneration in zebrafish, but does not otherwise participate in development.
- Protein Synthesis upon Acute Nutrient Restriction Relies on Proteasome Function
When mammalian cells are starved of amino acids, a cellular organelle, the proteasome, degrades preexisting proteins to supply the amino acids needed for protein synthesis.
- Category-Specific Cortical Activity Precedes Retrieval During Memory Search
Brain activation patterns characteristic of a previously observed object can be seen seconds before subjects consciously remember that object.
- Inducible Nitric Oxide Synthase Binds, S-Nitrosylates, and Activates Cyclooxygenase-2
Two important enzymes that induce inflammation in mammals physically interact and augment each other's activity, providing a potential target for anti-inflammatory drugs.
- Diversity and Function of Adaptive Immune Receptors in a Jawless Vertebrate
Lampreys insert different sequence modules into a constant gene to generate antigen-specific lymphocyte receptors, which can protect them against infection.
