Editors' Choice

Science  23 Oct 2015:
Vol. 350, Issue 6259, pp. 395
  1. Light Pollution

    Stay away from the light

    1. Sacha Vignieri

    Exposure to continual light conditions delays reproduction in tammar wallabies

    PHOTO: MICHELLE MCFARLANE PHOTOGRAPHY

    We live in a world flooded with light 24 hours a day. Before our recent harnessing of electricity, light was a reliable indicator of seasonal variability in resources and many species evolved to take advantage of this signal. Robert et al. show that artificial light can alter these species physiological responses and desynchronize their seasonal reproduction. Specifically, they found that nocturnal tammar wallabies that lived near a continuously lighted military base secreted less melatonin at night and that this delayed reproduction by nearly a month, as compared to animals living without artificial light nearby. Animals living near the base attempted to avoid lighted areas, but these results suggest that light pollution may have unavoidable physiological effects.

    Proc. R. Soc. London Ser. B 10.1098/rspb.2015.1745 (2015).

  2. Nanomaterials

    A tough shell for nanoparticles

    1. Phil Szuromi

    Nanoparticles made from compound semiconductors such as cadmium sulfide (CdS) can exhibit useful luminescent properties but can also be unstable with respect to ambient air and humidity, especially under conditions of strong illumination. Li et al. show that the passivation of metals by forming self-protecting oxides can be extended to nanoparticles. They added aluminum isopropoxide to the reaction mixture for synthesizing particles 8 nm in diameter, with a cadmium selenide core and a CdS shell. The aluminum dopant was transformed into a protective aluminum oxide coating that greatly improved photoprotection against blue light.

    J. Am. Chem. Soc. 10.1021/jacs.5b05462 (2015).

  3. Microbiome

    Seeing through microbiome development

    1. Caroline Ash

    Zebrafish show that the microbiome varies due to experience as animals age

    PHOTO: ©LACZ, GERARD/ANIMALS ANIMALS

    The transparent zebrafish is an ideal model for studying the codevelopment of the vertebrate gut and its microbiome. Stephens et al. took a pair of zebrafish and kept about 250 of their offspring in identical conditions, from hatching until they died of old age. Despite high levels of replication, variation is the order of the day. Young fish are variably colonized with environmental organisms. As the fish continue to develop, distinct bacterial communities emerge at different life stages, driven by the changing morphology of the gut and diet. Ultimately, despite the general patterns, adult gut communities are as distinct from each other as they are from their environment.

    ISME J. 10.1038/ismej.2015.140 (2015).

  4. Cell Renewal

    Factor adjusts cell number in gut

    1. Beverly A. Purnell
    Plausible reconstructed shapes of the asteroid JunoPHOTO: VIIKINKISKI ET AL., ASTRONOMY & ASTROPHYICS 581, (7 SEPTEMBER 2015) © EDP SCIENCES

    Cells read their environment to trigger an appropriate response for tissue homeostasis. Work now shows that intestinal progenitor cells use the RNA-binding protein Lin-28 to detect such a change and trigger insulin signaling as well as promote symmetric cell division to make full use of increased nutrient availability. Progenitor cells in the embryo and adult maintain their cell number by symmetric division but also generate specific cell types through asymmetric division. Lin-28 functions in early development to ramp up cell number, but an adult role is less clear. Work by Chen et al. identifies Lin-28 in the fly adult intestine as a factor controlling adult stem cell division, and it does so via the insulin-like receptor InR and independently of its well-known target Let-7.

    Development 10.1242/dev.127951 (2015).

  5. Minor Planets

    What shape is the asteroid Juno?

    1. Keith T. Smith

    3 Juno was the third asteroid to be discovered. However, no spacecraft has ever been very close to it, so its shape and surface features have remained poorly understood. Viikinkoski et al. have produced a model of Juno's shape by combining constraints from a full array of available data: optical light curves, near-infrared adaptive optics images, submillimeter interferometry, and the occultations of background stars. They find that the asteroid has a distorted lozenge-like shape with evidence of concave features, suggesting impact craters. The shape appears to be intermediate between that of the lumpy irregular smaller bodies and the near-spherical larger asteroids.

    Astron. Astrophys. 581, L3 (2015).

  6. Team Building

    Lab management: Lessons over 35 years

    1. Brad Wible

    A principal investigator is assembling her lab team. Whom should she hire? With this question in mind, Conti and Liu collected annual reports from the MIT Department of Biology that identified every principal investigator, postdoc, student, and lab technician who worked there from 1966 to 2000. They found that postdoc hiring drove a doubling in average lab size and in the number of publications per lab. The number of a lab's “breakthrough” papers in Science, Nature, or Cell was also influenced by postdoc numbers but was limited to those who had secured external fellowships. The numbers of graduate students and technicians, neither of which influenced overall publication rates, affected breakthrough work. Although the amount of NIH funding influenced productivity, this effect was eliminated after controlling for lab size and composition.

    Res. Policy 44, 1633 (2015).

  7. Heart Disease

    Patching up the injured heart

    1. Paula A. Kiberstis

    During a heart attack, heart muscle is deprived of oxygen and nutrients and dies as a result. Because heart muscle cells, or cardiomyocytes, have a limited capacity to divide, this damage is often permanent. Wei et al. describe an intervention that may help minimize the damage. Working with mice, they applied a collagen patch containing a protein called follistatin-like 1 to the heart immediately after a heart attack. Four weeks later, they saw signs of cardiomyocyte division, new blood vessel growth, and reduced scarring, which are consistent with heart muscle regeneration. Mysteriously, follistatin-like 1 has this beneficial activity only when it is synthesized by cells in the epicardium (a membrane layer surrounding the heart); myocardial-derived follistatin-like 1 was inactive.

    Nature 525, 479 (2015).