Editors' Choice

Science  07 Nov 2014:
Vol. 346, Issue 6210, pp. 713
  1. Biomedicine

    Disease biomarkers: What's the risk?

    1. Michael D. Crabtree
    CREDIT: MEDICALRF/SCIENCE SOURCE

    With approximately 60% of cardiac events occurring in patients of low or moderate risk, doctors need new biomarkers to accurately predict which of their patients will develop disease. Antibodies targeting the protein apolipoprotein A-1 (apoA-1), which plays a role in lipid metabolism, are one such candidate. Some of these antibodies may confer more risk than others, depending where on apoA-1 they bind. Using serum samples from cardiac patients, Teixeira et al. identified the peptides within apoA-1 where antibodies bound. These finding may point toward new therapeutic opportunities and improved biomarkers for predicting the risk of cardiovascular disease.

    J. Biol. Chem. 10.1074/jbc.M114.589002 (2014).

  2. Education

    One scoring rubric to rule them all

    1. Melissa McCartney

    Evaluating the effectiveness of undergraduate STEM (science, technology, engineering, and mathematics) courses requires assessing teaching practices. This is largely done through student course evaluations, which often have not been administered or collected in a consistent manner. To standardize this process, Wieman and Gilbert developed a rubric that assigns points to each teaching practice for which there is research showing that the practice improves learning. Although a potentially valuable tool for improving undergraduate STEM teaching, it will need to be periodically updated in order to incorporate the latest developments in teaching and learning research.

    CBE Life Sci. Educ. 13, 552 (2014).

  3. Conservation Biology

    Heed the warnings

    1. Sacha Vignieri
    CREDIT: ENCYCLOPAEDIA BRITANNICA/UIG VIA GETTY IMAGES

    This year marks the 100th anniversary of the passing of the last known passenger pigeon. Can studying its extinction, which happened rapidly despite the birds' relative abundance, inform today's conservation efforts? To find out, Stanton modeled this event and showed that the main causal factor was unmanaged over-harvest for food and sport. Furthermore, they found that if current monitoring and risk categorization had been in place, the rapid decline would have identified this species as endangered in time to protect it. More than just sad history, this study emphasizes that rapid declines suggest impending extinction, even if local abundance persists.

    Biol. Conserv. 10.1016/j.biocon.2014.09.023 (2014).

  4. Neurobiology

    Diversity generates complexity in the brain

    1. Pamela J. Hines

    Complexity in the brain derives not only from having a lot of neurons but also from the different ways neurons connect. Neurexin proteins help to establish these connections, but they themselves complicate the picture. Alternative splicing adds diversity to neurexins' protein coding regions by creating mRNAs with different combinations of exons. This diversity broadens the range of molecules bound by neurexins and modulates when and where neurons express them. To get a complete picture of neurexin diversity, Schreiner et al. sequenced the many neurexin transcripts produced adult mouse brains. Although two types of neurexins made good use of the diversity available to them, a third neurexin barely scratched the surface of its options.

    Neuron 84, 386 (2014).

  5. Surface Chemistry

    Charge control of silicon chemistry

    1. Phil Szuromi

    A site on an organic molecule often can be made more or less reactive by changing its neighboring functional groups so that they add or withdraw electronic charge from the site. Piva et al. show a similar effect for the reaction of dangling bond states on a hydrogen-terminated silicon surface with unsaturated organic molecules such as styrene. They modified the electronic properties of the surface by changing the surface concentration of arsenic dopants and used scanning tunneling microscopy to monitor product formation. Negatively charged doubly occupied dangling bonds, which were more prevalent on the highly doped surfaces, were less reactive than neutral singly occupied dangling bonds. These results are consistent with density functional theory calculations and help explain the heterogeneous reactivity of dangling bonds on silicon surfaces.

    Phys. Rev. B 90, 155422 (2014).

  6. Cosmology

    Out with the WIMPs, in with the SIMPs?

    1. Adrian Cho

    Physicists seeking to identify dark matter—the stuff whose gravity may bind the galaxies—may have been stalking the wrong particle. The favorite candidate is the weakly interacting massive particle (WIMP), thought to have a mass between 1 and 1000 times that of a proton and interacting with each other and ordinary matter only through the weak nuclear force. But hypothetical strongly interacting massive particles (SIMPs) would do just as good a job at explaining the stuff, report Hochberg et al. They argue that dark matter could also consist of lighter particles that have a mass around one-10th of the proton and interact with one another very strongly, but with ordinary matter much more weakly than WIMPs. Strongly interacting dark matter would help resolve some differences between dark matter simulations and observed properties of galaxies.

    Phys. Rev. Lett. 10.1103/PhysRevLett.113.171301 (2014).

    SIMPs would help reconcile observed properties of galaxies and models of dark matter distribution (shown).

    CREDIT: RALF KAEHLER, OLIVER HAHN AND TOM ABEL/KAVLI INSTITUTE FOR PARTICLE ASTROPHYSICS AND COSMOLOGY
  7. Geochemistry

    Constructing geochemical geometry

    1. Brent Grocholski

    Lavas erupted from oceanic hot spots have diverse chemistries that provide clues to the evolution of Earth's mantle. Jackson et al. develop a conceptual model of chemical variations within the mantle plume supplying the Samoan hot spot, by correlating geographic and geochemical variations in the erupted volcanic products. Lead and helium isotopes identify four distinct geochemical groups, all embedded in a common component that defines the mantle plume. The lens-like embedded materials appear to be isolated from one another, mixing only with the common component and creating compositionally distinct lavas in different spots along the Samoan hot spot track.

    Nature 10.1038/nature13794 (2014).

  8. Kidney Disease

    The dark side of protective genes

    1. Paula A. Kiberstis

    Aberrant antibody deposits in the kidney characterize immunoglobulin A nephropathy (IgAN), a disease most prevalent in East Asians. Kiryluk et al. studied the underlying genetics of IgAN and found that variants of genes with roles in maintaining the intestinal epithelial barrier or in the immune response to mucosal pathogens conferred an elevated risk of IgAN. People living in areas with the greatest diversity of helminthes showed the highest genetic risk for developing IgAN. This intriguing correlation suggests that the high incidence of IgAN in certain regions might be a consequence of protective adaptation to mucosal pathogens.

    Nat. Genet. 10.1038/ng.3118 (2014).

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