Editors' Choice

Science  16 Feb 2018:
Vol. 359, Issue 6377, pp. 757
  1. Collateral Damage

    A world at war on science

    1. Brad Wible

    World War I pervasively reduced scientific exchange between opposing countries.

    PHOTO: WELLCOME COLLECTION

    As casualties mounted along the frontlines of World War I, the international scientific frontier was no exception. Iaria et al. show that the war drove down both citations of and similarities to research from scientists in the opposing camp (Allied versus Central nations). Leading-edge science was most affected. Relative to researchers whose prewar work referenced the most highly cited 5% or 3% of research from the opposing camp, prolific researchers who depended on the top 1% from behind enemy lines showed the steepest declines during the war in terms of publications in top journals, Nobel-nominated breakthroughs, introducing new scientific terms, and having those new terms mentioned in granted patents.

    Quart. J. Econ. 10.1093/qje/qjx046 (2018).

  2. Immunology

    Innate receptor sees cancer growth factor

    1. Seth Thomas Scanlon

    Innate lymphoid cells (ILCs) and natural killer (NK) cells express receptors that recognize ligands associated with pathogens and cellular stress. One such human receptor, NKp44, has been implicated in recognizing transformed cells, but its actual target has remained elusive. Barrow et al. report that a member of the platelet-derived growth factor (PDGF) family, PDGF-DD, is a ligand for NKp44. Notably, cancer cells use PDGFs to promote their survival, growth, and dissemination. PDGF-DD induced ILC and NK cell cytokine secretion in vitro. Furthermore, the expression of PDGF-DD in tumors promoted increased rejection in NKp44-expressing transgenic mice. This was further enhanced by anti-CD96 checkpoint blockade. A meta-analysis of human cancer data hints that NKp44–PDGF-DD interactions may have positive clinical outcomes for certain cancers, such as glioblastoma.

    Cell 10.1016/j.cell.2017.11.037 (2018).

  3. Paleontology

    Around the world in 170 million years

    1. Sacha Vignieri

    Dinosaurs followed a classic pattern of adaptive radiation as they spread across the planet.

    CREDIT: JULIUS T. CSOTONYI

    Dinosaurs were the dominant vertebrate on the planet for more than 170 million years. During that time, they dispersed and diversified into the myriad of forms that we recognize from fossils today. O'Donovan et al. use a phylogenetic modeling approach, in combination with fossil locations, to reconstruct locations of origin and map the path of dinosaur evolution and radiation from their emergence to their demise. The authors find that dinosaurs followed a classic pattern of evolutionary radiation from their origin in what is now South America. Dinosaur speciation rates were faster early in their history and slowed toward the end. Further, the authors conclude that early speciation was likely due to vicariance, whereas later speciation events were shaped by ecological pressures and niche filling.

    Nat. Ecol. Evol. 10.1038/s41559-017-0454-6 (2018).

  4. Geophysics

    Hot mantle rushes in to fill the void

    1. Brent Grocholski

    Volcanism in the western United States over the past 20 million years is tied to the subducting Juan de Fuca and Farallon slabs and mantle dynamics. Zhou et al. present a geodynamic model of the region using past plate motion, current seismic tomographic imaging, and volcanic history. They find that the large amount of intraplate volcanism in the past required the intrusion of hotter mantle below the western United States. This intrusion was driven by the sinking of the ancient Farallon slab beneath the region.

    Nat. Geosci. 10.1038/s41561-017-0035-y (2018).

  5. Tissue Homeostasis

    Checks and balances at a cellular level

    1. Valda Vinson

    To stay healthy, tissues must maintain proper ratios of their constituent cell types. Adler et al. developed a framework for describing a range of circuit topologies between two cell types where each secretes a signal that is sensed by the other. Without regulation, both cell types grow to a stable cell number close to the carrying capacity of the system. To maintain one cell type at lower numbers, production of the signal that it senses could be down-regulated by the signal that it secretes, or it could remove its cognate signal by endocytosis. Endocytosis allows a faster response and is more robust to parameter variation. The concepts also apply to three- and four-cell circuits and provide a basis for understanding tissue homeostasis.

    Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1714377115 (2018).

  6. Climate Change

    Cities feel the heat of climate change

    1. Julia Fahrenkamp-Uppenbrink

    Many climate change studies aim to determine how the global annual mean surface air temperature has changed or will change over time. Since 1975, this temperature has changed at a rate of about 0.15° to 0.2°C per decade. But as Papalexiou et al. show, this figure does not capture the rising extremes in heat that many people living in cities around the world are experiencing. In the past three decades, the highest temperatures of the year at 9000 stations have risen by an average of 0.25°C per decade. In many big cities, the rise has been even larger, with Houston, Moscow, and Paris experiencing rises of more than 0.8°C per decade. These fast rises in the most extreme temperatures increase the risk of heat-related fatalities.

    Earth's Future 10.1002/2017EF000709 (2018).

  7. Molecular Biology

    Retrotransposons acting as lightning rods

    1. Steve Mao

    Long interspersed nuclear elements–1 (L1s) are abundant retrotransposons in the human genome. L1s can duplicate and jump in the genomes of neural progenitor cells in a process called retrotransposition. High levels of retrotransposition are associated with neuronal diversity and pathology. Jacob-Hirsch et al. mapped genome-wide retrotranspositions in human brain samples. The majority of L1 insertions in brains of normal donors occur in preexisting L1 elements that serve as “lightning rods” to guide safe landings of potentially harmful retrotranspositions. However, in brains of patients with neurodevelopmental disorders, enhanced transpositions can occur in genes associated with neurologic and psychiatric disorders, increasing the risk of damaging insertions.

    Cell Res. 10.1038/cr.2018.8 (2018).