Editors' Choice

Science  27 Oct 2017:
Vol. 358, Issue 6362, pp. 494
  1. Forest Ecology

    Temperate forest dynamics and climate

    1. Andrew M. Sugden

    Temperate forest composition and disturbance regimes may shift during climate change, with consequences for the climate system.

    PHOTO: HERBERT KRATKY/IMAGE BROKER/AURORA PHOTOS

    Climate change affects biota, and biotic effects feed into the climate system. In a modeling study, Thom et al. investigated how the present cooling effect of temperate forest on local climate might change over the next 200 years as climate warming shifts the patterns of forest disturbance. Their model, applied to temperate forest in Austria, indicates marked nonlinear changes in tree species composition and disturbance regimes over time, with potential reductions in the climate regulation function of the forest. The results also indicate how the composition of these forests might best be managed to achieve optimal levels of carbon storage, evaporative cooling, and albedo to mitigate climate change.

    Ecol. Monogr. 10.1002/ecm.1272 (2017).

  2. Reprogramming

    Inflammation and cardiac reprogramming

    1. Beverly A. Purnell

    Tissue repair after a heart attack is a balance between inflammation to remove cell debris and active cell regeneration. Intervening in cell replacement and reprogramming thus offers therapeutic options to promote healing with minimal scar formation by fibroblasts. However, reprogramming of adult fibroblasts into pulsatile cardiomyocytes is not straightforward. To improve the reprogramming protocol, Zhou et al. performed an unbiased screen of 786 transcription factors, epigenetic regulators, cytokines, and nuclear receptors. The screen identified a transcription factor (ZNF281) that associates with the essential cardiac development transcription factor GATA4 to stimulate cardiac reprogramming and suppress inflammatory signaling. Anti-inflammatory drugs also stimulate cardiac gene expression. ZNF281 appears to act at a nexus between cardiac and inflammatory gene programs that exert opposite influences on fibroblast reprogramming.

    Genes Dev. 10.1101/gad.305482.117 (2017).

  3. Microbiota

    Drone technology for whale health

    1. Caroline Ash

    It is hard to obtain biological samples from whales. However, whales do shed lots of material as oily slicks behind them and in their massive exhalations, or blows, at the surface. Exhalations contain tissue debris and respiratory microorganisms. Apprill et al. used a small drone furnished with a Petri dish and a 96-well plate to capture exhaled material from 28 humpback whales off Vancouver Island, Canada, and Cape Cod, USA. 16S ribosomal RNA sequencing of bacteria and archaea revealed that animals from the two populations have diverse, distinctive, and yet surprisingly consistent core microbiomes in common with each other and with small, toothed cetaceans: bottlenose dolphins. Fortunately, in this study, no known cetacean respiratory pathogens were detected. These data offer a glimpse into what a healthy microbiota state might look like for a baleen whale.

    mSystems 10.1128/mSystems.00119-17 (2017).

  4. Photochemistry

    Coupling up for enhanced reactions

    1. Ian S. Osborne

    Light is an essential ingredient in many biological contexts, such as photosynthesis and vision. The underlying assumption in such optical processes is that a single quantum of light, a photon, is absorbed per absorbing molecule, resulting in an excited state of the molecule. This places an upper limit on the quantum efficiency of any photochemical process. Galego et al. show theoretically how this limit can be overcome. By considering molecules in an optical cavity, a light-matter hybrid “supermolecule” can be created as the molecules couple together over long distance with a confined optical mode of the cavity. A single photon then can trigger a many-molecule reaction. Understanding, controlling, and enhancing the photochemical process will be crucial for developing new energy-harvesting technology.

    Phys. Rev. Lett. 119, 136001 (2017).

  5. Physics

    Figuring the shape of the electron

    1. Jelena Stajic

    Although incomplete, the Standard Model (SM) of particle physics has been generally dependable in making correct experimental predictions. A curious case is the electric dipole moment of the electron (eEDM), which the SM predicts to be a lot smaller than do theories that aim to extend the SM. The eEDM can be measured using experiments with polar molecules and molecular ions, with the former boasting large fluxes and the latter long interrogation times. Cairncross et al. used molecular ions of HfF to find that the eEDM has a magnitude of less than 1.3 × 10−28 e cm, confirming an earlier result from neutral molecule measurements. Future experiments may yield even more precision, improving the ability to distinguish between the various extensions to the SM.

    Phys. Rev. Lett. 119, 153001 (2017).

  6. Aviation

    A bump in the high road

    1. H. Jesse Smith

    Clear-air turbulence will become more common and more intense as the climate warms.

    PHOTO: ISTOCK.COM/XJBEN

    Clear-air turbulence (CAT), which is invisible to the naked eye and undetectable by sensors onboard aircraft, can cause discomfort or injuries to passengers and often forces planes to alter their flight paths to avoid it. Storer et al. use a global climate model to project how climate warming is expected to influence CAT. They find large relative increases in CAT, particularly in the midlatitudes, with some regions experiencing several times more turbulence during the period from 2050 to 2080 than now. Within that interval, severe CAT becomes as common as moderate CAT has been historically, and the strongest turbulence increases the most.

    Geophys. Res. Lett. 10.1002/2017GL074618 (2017).

  7. Molecular Biology

    Mobile elements' joyride

    1. Steve Mao

    Retrotransposons are mobile DNA elements that replicate themselves in genomes by taking full advantage of the host environment. Tiwari et al. show that they have another trick up their sleeves to ensure inheritance to the next generation. In fruit flies, retrotransposon RNAs mimic an endogenous transcript and hijack its dedicated transport machinery, which then transports them into the germ plasm of developing oocytes. Fortunately, flies express a protein called p53 that restrains retrotransposon activity. But the host genome may have also benefited from this mechanism and been able to shape its own evolution by exploiting the retrotransposons.

    Curr. Biol. 10.1016/j.cub.2017.08.036 (2017).