Editors' Choice

Science  15 Jun 2018:
Vol. 360, Issue 6394, pp. 1199
  1. Particle Physics

    In the company of top quarks

    1. Jelena Stajic

    Part of the Compact Muon Solenoid at CERN's Large Hadron Collider

    PHOTO: NG IMAGES/ALAMY STOCK PHOTO

    The coupling of elementary particles to the Higgs boson is correlated with their masses. For some particles, it can be measured by observing the decay of the Higgs into those particles. The top quark, however, is too heavy for the Higgs to decay into. Therefore, Sirunyan et al. from the Compact Muon Solenoid Collaboration at the Large Hadron Collider (LHC) looked at the processes in which the Higgs boson is produced in conjunction with the top quark and its antiparticle. By combining the results from the runs at different center-of-mass energies of proton-proton collisions at the LHC, they found that such processes indeed occurred and that the signal strength was consistent with the predictions of the Standard Model of particle physics.

    Phys. Rev. Lett. 120, 231801 (2018).

  2. Ecosystems

    Salmon teleconnection disservice

    1. Caroline Ash

    Pink salmon spawning in an Alaskan river

    PHOTO: MICHAEL QUINTON/MINDEN PICTURES

    Pink salmon (Oncorhynchus gorbuscha) populations in the North Pacific have grown during the past four decades. Fish numbers have expanded partly in response to climate change and partly because of hatchery release from Russia and the United States. Perhaps surprisingly, this is not entirely good news. Among other problems of competition, Springer et al. have discovered a remarkable 15,000-kilometer link between the pink salmon and the migration of a shearwater (Ardenna tenuirostris), which nests in Australia and New Zealand and winters in the North Pacific. Using data collected from ship-towed continuous plankton recorders, Batten et al. show that the pink salmon's consumption of zooplankton could be the cause of starvation and mass mortality of the birds. This in turn affects Pacific aboriginal societies that harvest the returning birds for food.

    Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1720577115 (2018); Fisher. Oceanogr. 10.1111/fog.12276 (2018).

  3. Microbiome

    Gut bacteria relieve epilepsy

    1. Gemma Alderton

    A high-fat and low-carbohydrate, or ketogenic, diet is used to treat children with refractory epilepsy. Olson et al. show that the ketogenic diet enriches populations of the gut commensal bacteria Akkermansia muciniphila and Parabacteroides spp. The presence of these species appears to protect against induced epileptic seizures in mice, even in those on a nonketogenic diet. Together, these bacteria alter the profile of circulating metabolites, which subsequently modulates metabolism in the brain. Specifically, reduction in γ-glutamylation of circulating amino acids and elevated hippocampal GABA (γ-aminobutyric acid)/glutamate are associated with seizure protection in mice.

    Cell 10.1016/j.cell.2018.04.027 (2018).

  4. Metabolism

    RNA processing for metabolic control

    1. L. Bryan Ray

    Autophagy is a cellular response to nutrient starvation that allows cells to recycle existing molecules and organelles. Tang et al. investigated the mechanisms by which TORC1 (target of rapamycin complex 1) regulates autophagy. They discovered that regulation occurs through control of RNA processing. Using a genetic screen in fruitflies, they pinpointed the CPA (cleavage and polyadenylation) complex as the regulator of autophagy. CPA in turn regulates polyadenylation and alternative splicing of RNAs encoding the key proteins that regulate autophagy. This control appears to be conserved in mammalian cells, too: Loss of a component of the CPA complex disrupted regulation of metabolism and autophagy in cultured human cells.

    Cell Metab. 10.1016/j.cmet.2018.02.023 (2018).

  5. Human Genetics

    Variants may affect disease heritability

    1. Laura M. Zahn

    Huntington's disease (HD) is a late-onset neurodegenerative disease caused by the inheritance of an expansion of a trinucleotide repeat in the huntingtin (HTT) gene. A Venezuelan population exhibits an earlier onset of HD than is observed in individuals of European ancestry. Chao et al. sequenced alleles from ∼400 Venezuelan individuals carrying a pathogenic HTT allele. Although Venezuelan sequence–specific changes were evident in the allele, they did not explain early onset of HD. A genome-wide investigation comparing European and Venezuelan individuals revealed other Mendelian modifying genes. This study demonstrates the importance of population-specific investigations of genetic diseases.

    PLOS Genet. 10.1371/journal.pgen.1007274 (2018).

  6. Quantum Sensing

    A quantum enhancement for plasmonic sensors

    1. Ian S. Osborne

    Laser light can induce electronic excitations on metal surfaces. These excitations, or plasmons, are sensitive to the surface environment and are now routinely used in chemical and biological sensing applications. Dowran et al. show that the sensitivity of these plasmonic sensors can be enhanced by using quantum states of light. They replace the laser light (used in the classical configuration) with quantum light, in this case a twin beam of entangled photons; one beam is used as a reference and the other to excite the surface plasmons. They find an appreciable sensitivity enhancement in the quantum configuration. Moreover, the reduced light intensity could also prove useful for the detection of light-sensitive chemical or biological samples.

    Optica 5, 628 (2018).

  7. Structural Biology

    Edge cases cause trouble

    1. Michael A. Funk

    Single-particle cryo–electron microscopy detects macromolecules trapped in a thin layer of vitreous ice. High-resolution, accurate reconstructions benefit from randomly arranged and well-dispersed particles, but biological samples do not always cooperate. Noble et al. used cryo–electron tomography to investigate particle distributions in cryo–electron microscopy samples. Troublingly, most macromolecules localized to the air-water interface, a phenomenon associated with denaturation of proteins and that may result in preferred orientations and uneven distribution of particles. Assessment of samples with cryo–electron tomography before further data collection would allow for tailored optimization of sample conditions, which should lead to higher-resolution structures and enable early detection of artifacts.

    eLife 10.7554/eLife.34257 (2018).