Editors' Choice

Science  13 Feb 2015:
Vol. 347, Issue 6223, pp. 733
  1. Plant Science

    HIV antivirals from engineered soybeans

    1. Pamela J. Hines

    Engineered soybeans could produce key antiviral

    PHOTO: © DESIGN PICS INC/ALAMY

    Affordable antivirals used as vaginal microbicides could have a substantial impact on the HIV epidemic, particularly in the developing world. One potential candidate is cyanovirin-N, a protein produced by a cyanobacterium that prevents viral entry in preclinical studies. Large-scale production of cyanovirin-N, however, is prohibitively expensive. To get around this, O'Keefe et al. genetically engineered soybean seeds to make cyanovirin-N. The seeds produced large quantities of the antiviral and it survived the normal industrial processing systems already in place for soybeans. By rough estimate, one greenhouse growing engineered soybeans could provide enough cyanovirin-N to protect a woman for 90 years.

    Plant Biotech. J. 10.1111/pbi.12309 (2015).

  2. Neuroscience

    Brain activity predicts later recollection

    1. Peter Stern

    When people remember details about a specific event (a process referred to as “recollection”), a part of their brain called the core recollection network is highly active. To better understand the underlying connectivity of different brain regions involved in recollection, King et al. scanned the brains of people while they were retrieving earlier memories. Memory retrieval led to increased activity in specific areas of their brains, both in the core recollection network and in other regions. By analyzing the active areas in different people, areas of functional connectivity emerged. More accurate recollections correlated with greater connectivity among these different regions.

    J. Neurosci. 35, 1763 (2015).

  3. Symbiosis

    Plastid thieves escape starvation

    1. Caroline Ash

    Ingested algae pitch in to prevent starvation

    CREDIT: JAN DE VRIES AND STEFFEN KÖHLER/CAI

    Green sea slugs feed on algae, and in the process they take up photosynthetic plastids from the algae. The plastids stay intact in the slug's gut cells for months, and the slugs benefit nutritionally from ongoing photosynthesis. So much so that that some scientists think that the plastids can prevent slugs from dying of starvation. But photosynthesis and starvation can also produce toxic products that cause the slugs to die. de Vries et al. found one species of slug that does not rely on photosynthesis to keep it going during hard times. This slug resists death by ramping up mechanisms to remove damaged plastids and toxins.

    Proc. R. Soc. B 10.1098/rspb.2014.2519 (2015).

  4. Biomaterials

    Better bone patching with hydrogel foam

    1. Marc S. Lavine

    Pore structure of a 3D architectured hydrogel (ArcGel)

    CREDIT: HZG 2015

    Bone grafts are currently the clinical standard for replacing larger bone defects caused by trauma, infections, or tumors. Degradable biomaterials are not sufficient for regenerating bone without the addition of peptides or growth factors to attract and direct the needed cells. Neffe et al. devised a one-step process for creating hydrogels through a foaming process using gelatin and lysine connected by urea junctions. The gels form an open porous structure that allows cells to invade and provides support for their adhesion, as well as offering tailorable local environments and mechanical properties and controlled and rapid degradation. In vivo testing for the regeneration of 5-mm femoral defects in rats showed healing capacity comparable to that of bone grafts after 6 weeks.

    Adv. Mater. 10.1002/adma.201404787 (2015).

  5. Biomechanics

    Measuring the forces that shape tissues

    1. Valda Vinson

    During development, intracellular molecular motors generate forces that cause cells to change shape and remodel their contacts with other cells. But exactly how these forces change cell shape is largely unknown. Bambardekar et al. used light-sheet microscopy and optical tweezers to image a developing fruit fly embryo and directly measure the tension at cell-cell junctions. As morphogenesis progressed, the tension increased and became anisotropic (directional) across the embryo. On the basis of these measurements and by monitoring the effect of cell deformations on neighboring cells, the authors then created a model that predicts how local deformations propagate through the tissue.

    Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1418732112 (2015).

  6. Environmental Science

    Energy and wastewater treatment, too

    1. Nicholas S. Wigginton

    Treating wastewater removes organic matter that would otherwise harm the environment when released back into waterways. New bioelectrochemical systems provide the added benefit of using this organic matter as a fuel for bacteria to generate hydrogen gas or electricity during wastewater treatment. However, concerns remain about whether the other functions of wastewater treatment, including reducing the amount of trace organic compounds released back into the environment, will be lost. Werner et al. tested the breakdown of low levels of pharmaceuticals, pesticides, and antibiotics in microbial fuel cells and microbial electrolysis cells. Although some of these contaminants persisted after passing through the microbial reactors, the breakdown efficiency was similar to that of most modern wastewater treatment methods.

    Water Res. 10.1016/j.watres.2015.01.013 (2015).

  7. Optics

    A temperature probe for the ultracold

    1. Ian S. Osborne

    The temperature of an everyday macroscopic object is well understood and easy to measure. The concept of temperature, however, becomes blurry when the number of particles in a system becomes so small that the ensemble breaks down into a number of individual components, such as for atoms or molecules trapped in an optical lattice and cooled to ultralow temperatures. McDonald et al. demonstrate a spectroscopic technique that uses the line shift and change in the line shape of an atomic or molecular transition to determine the temperature of trapped atoms or molecules down to nanokelvin temperatures. This technique should prove useful in a range of applications, including metrology and probing the energetic dynamics of ultracold chemical reactions.

    Phys. Rev. Lett. 114, 23001 (2015).

  8. Cancer Research

    Lifetime risk of cancer goes up

    1. Carolyn Gramling

    More than 50% of people born in the U.K. since 1960 will develop cancer in their lifetimes, finds a new study. Combining actual cancer rates from 1951 to 2012 with projected rates for 2013 through 2060, Ahmad et al. estimated lifetime risks for men and women born in 1930 with those for men and women born from 1931 to 1960. For men, the risk increased from 38.5% for those born in 1930 to 53.5% for those born in 1960; for women, risk increased from 36.7% to 47.5%. Increasing life expectancy was the primary reason for the risk increase.

    Br. J. Cancer, 10.1038/bjc.2014.606(2014).