Editors' Choice

Science  30 May 2014:
Vol. 344, Issue 6187, pp. 985
  1. Plant Ecology

    Ancient leaves tattle on insects

    1. Laura M. Zahn

    Insects chewing leaves in the forest


    Paleoentomologists have long estimated past levels of insect diversity by counting different types of leaf damage in fossils—but they've had little evidence of whether leaf damage is, in fact, a good proxy for insect diversity. Carvalho et al. examined the canopies of 24 tree species in modern tropical forests to assess the level of insect damage and identify the types of insects associated with the observed damage. The number of insect species collected from the forests correlated positively with the different types of leaf damage seen on leaves fed to these insects in the laboratory. The findings support the practice of extrapolating from fossils of chewed leaves to the diversity of the ancient chewers.

    PLOS One 9, 94950 (2014).

  2. Aging

    Tracking down a tonic for a long life

    1. L. Bryan Ray

    Scientists may not yet have found the fountain of youth, but Ye et al. now report on a screen for drugs that can extend life span in the worm Caenorhabditis elegans. Starting with a collection of over 1200 drugs that have or are suspected to have activity in human cells, they identified nearly 60 compounds that extended life span up to 43%. Many of the compounds targeted proteins that function in signaling pathways between cells, such as hormone or neurotransmitter receptors, particularly those for adrenaline and noradrenaline, serotonin, dopamine, histamine, and serotonin. Given that humans and worms share some aging mechanisms, these results may help bypass the time and expense of similar studies in mammals.

    Aging Cell 13, 206 (2014).

  3. Materials Science

    Weaving solar energy into fabrics

    1. Jake Yeston

    A solar cell textile integrated in a fabric.


    Imagine a sweatshirt that charges your cell phone or a sail that powers a ship's radio. To bring solar-powered fabric closer to reality, Pan et al. modified the standard design of a dye-sensitized solar cell by sandwiching the dye and electrolyte between two flexible electrodes. Earlier approaches twisted the electrodes together into cylinders. Instead, Pan et al. stacked grids of titanium dioxide-coated titanium wires and carbon nanotube fibers, making it easier to connect multiple cells. With a solid-state electrolyte, the cells lost less than 6% of their efficiency over 300 hours of operation in air. As a proof of principle, the authors used several woven cells connected in series to power a red light–emitting diode.

    Angew. Chem. Int. Ed. 53, 10.1002/anie.201402561 (2014).

  4. Education

    Making business students science-savvy

    1. Melissa McCartney

    What happens when science pedagogy goes to business school? Future business leaders become knowledgeable about the latest developments in renewable-energy technology. Rodgers engaged undergraduate business management students in developing their business skills while learning about renewable-energy technologies by having them take a basic course on energy sources and prepare a “rocket pitch”—a short presentation designed to recruit investors. Rodgers also had the students research and design a new environmental technology project. The experience exposed them to primary sources and immersed them in debate about which energy source would be an ideal investment for the future. The approach, Rodgers found, prepared the business students to use scientific knowledge in their future business decisions.

    J. Coll. Sci. Teach. 43, 28 (2014).

  5. Cancer

    Serendipity rules in cancer therapy

    1. Paula A. Kiberstis

    While testing cancer drugs in a mouse model of a deadly blood cancer, multiple myeloma, Shortt et al. made a startling discovery: On its own, an inert solvent commonly used as a drug delivery vehicle can halt the cancer's growth. The researchers noticed that control mice treated with N-methyl-2-pyrrolidone (NMP) survived longer than control mice treated with other drug delivery vehicles. Further analyses of NMP in cultured cells and live mice confirmed the solvent's antimyeloma activity. NMP shares certain mechanistic similarities with other promising drug candidates for myeloma that were discovered in more traditional ways. Plans for phase 1 clinical trials are under way.

    Cell Rep. 7, 10.1016/j.celrep.2014.04.008 (2014).

  6. Chemistry

    Nanoparticle transformations in 3D

    1. Phil Szuromi

    A golden nanoparticle framework.


    When silver nanocubes react with gold ions, they combine into hollow-frame octohedral structures. Now Goris et al. have imaged the process with electron tomography and x-ray element mapping to see how it happens. Goris et al. reacted silver nanocubes with HAuCl4 and found that three silver atoms were oxidized for every gold atom consumed. They removed a series of samples at different points in the reaction and used three-dimensional (3D) tomography to see the steps. First, a pinhole opens up in one facet. Next, all the facets open up. Then the vertices flatten to become new facets, until finally only an octahedral wire frame structure remains. The analysis also revealed that a protective gold layer surrounded the initial pinhole and forced the reaction of silver from the interior of the nanocube.

    Nano Lett. 10.1021/nl500593j (2014).

  7. Physics

    Stretching graphene to switch it off

    1. Jelena Stajic

    Graphene, which is made up of a single layer of carbon atoms arranged in a honeycomb pattern, has remarkable mechanical and electrical properties, but conducts electricity almost too well. Therefore, researchers are looking for ways to switch off graphene devices more easily. It is known that graphene sometimes develops electronic states in which it doesn't conduct electricity when it is placed on hexagonal boron nitride (hBN), another honeycomb-structured material. Woods et al. now have found that graphene stretches and adapts locally to the underlying hBN lattice so that the atoms of the two lattices lie on top of each other, as long as the angle of orientation of the graphene layer with respect to hBN is not too great. The matched areas probably contribute to the nonconducting states through the homogeneity of their electronic properties.

    Nat. Phys. 10.1038/nphys2954 (2014).

  8. Oceanography

    Arctic sea ice traps floating plastic

    1. Eric Hand

    Scientists are all too familiar with microplastics—tiny polymer beads, fibers, or fragments—in ocean eddies or near coastlines. But currents, it turns out, also carry them to the Arctic. Obbard et al. melted and filtered parts of four Arctic sea-ice cores, analyzing the remaining particles' chemistry. They found rayon, as well as polyester, nylon, and other synthetic polymers. As Arctic ice freezes, the researchers argue, it traps floating microplastics, accumulating hundreds of particles per cubic meter: three orders of magnitude larger than some counts of particles in the Pacific Garbage Patch. And melting sea ice, they note, could release more than 1 trillion pieces of plastic to the ocean in the next decade.

    Earth's Future 10.1002/2014EF000240 (2014).

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