Editors' Choice

Science  11 Oct 2019:
Vol. 366, Issue 6462, pp. 197
  1. Plant Ecology

    Plants, soils, and climate

    1. Andrew M. Sugden

    The perennial herb Plantago lanceolata

    CREDIT: AVALON/PICTURE NATURE/ALAMY STOCK PHOTO

    Environmental change is rarely straightforward in its consequences for natural communities, because of the complexity of spatial and temporal interspecific interactions. Rasmussen et al. experimentally studied the effects of temperature and moisture variation on the growth patterns of a perennial herb (Plantago lanceolata) and its associated soil microbial community. They used a reciprocal multifactorial design, using plants and soil communities from three different habitats in Sweden. Although warming and increased moisture had a generally positive effect on plant growth, the strength of the response depended on the origin of the plants, as did the responses of root-associated fungi. Thus, climate change may be expected to produce complex patterns of variation in plant-soil interactions, which may be difficult to predict.

    J. Ecol. 10.1111/1365-2745.13292 (2019).

  2. Materials Science

    Glassy carbon for maximum impact

    1. Marc S. Lavine

    Materials designed for impact absorption need to be able not only to cope with high-stress deformations but also to accommodate high strain, as the energy absorbed is the integral of the stress-strain response. Although lightweight designed materials, such as those based on trusses, can show high strength or high deformability, they usually cannot do both. Guell Izard et al. devised an architected material with smooth interconnected surfaces, similar to a shell, that they fabricated out of glassy carbon. Under optimal conditions with a spinodal topology, the propagation of cracks is impeded as they do not align with the stress direction. This enables a slow, progressive failure during impact, and thus higher energy absorption.

    Small 10.1002/smll.201903834 (2019).

  3. Conservation

    Species shuffling by humans

    1. Sacha Vignieri

    Human activities are resulting in ubiquitous distribution of some species, such as the pigeon, Columba livia.

    PHOTO: EYEEM/ALAMY STOCK PHOTO

    Zoogeographic regions describe general patterns of faunal organization across the world and our definition of these regions has largely been consistent since the versions put forward by Wallace and Sclater in the mid to late 19th century. As the result of thousands of years of evolution, these regions have largely been thought to be relatively static and resistant to change. Human activities, especially in the 20th and 21st centuries, have caused substantial upheavals in natural systems, leading to the question of whether our activities have also affected these larger faunal associations. Bernardo-Madrid et al. surveyed mammals, amphibians, and birds using large datasets and network approaches to determine whether classic associations have been altered. They found that the introduction and movement of species between regions have led to homogenization of many of these regions. Further, predicated extinctions could exacerbate these trends, leading to loss of regional faunal uniqueness.

    Ecol. Lett. 22, 1297 (2019).

  4. Biotechnology

    Expanding DNA storage capacity

    1. Steve Mao

    DNA makes a good archival medium for information storage, thanks to its remarkably high physical density and the relatively low cost of high-throughput sequencing. However, its synthesis presents a challenge both technically and economically. Two recent studies invented similar methods to augment DNA-based information storage capacity. Instead of using only four standard DNA nucleotides (A, T, G, and C), Choi et al. and Anavy et al. have developed platforms for reading and writing degenerate nucleotides and mixtures of nucleotides in various predetermined ratios. This expanded alphabet enables higher information content per synthesis cycle.

    Sci. Rep. 9, 6582 (2019); Nat. Biotechnol. 37, 1229 (2019).

  5. Nanomaterials

    Better contact to WSe2 nanosheets

    1. Phil Szuromi

    The high electron and hole mobility of tungsten selenide (WSe2) nanosheets should make them ideal semiconductors for field-effect transistor (FET) devices, but with typical contact materials (silica layers on silicon and gold), mobilities, and on-off ratios fall to impractical levels. Stoeckel et al. functionalized one or both sides of WSe2 single-layer nanosheets with molecules containing silane groups. The tails of these molecules formed monolayers on the nanosheets, whereas the head groups formed monolayers on silica. These molecules also appeared to functionalize defect sites, and their presence changed the work function of the nanosheet and decreased the contact resistance to gold. High mobilities enabled unipolar and, for doubly-functionalized nanosheets, ambipolar FET operation in devices with gold top contacts.

    ACS Nano 10.1021/acsnano.9b05423 (2019).

  6. Microbiome

    Antibiotics blunt flu immunity

    1. Priscilla N. Kelly

    The microbiome influences our immune system and how we respond to various physiological stresses. Hagan et al. report that depleting gut microbiota reduces the ability of influenza vaccine to induce functional immunity in humans. The researchers conducted a small clinical trial of healthy individuals who had low prior exposure either to influenza virus or to the vaccine. One group took a course of broad-spectrum antibiotics before receiving the vaccine, while the other group did not take antibiotics and only received the vaccine. Antibiotic use diminished the gut microbiome composition and impaired the ability of the immune system to generate antibodies. Treatment with antibiotics also disturbed bile acid metabolism and caused inflammatory responses.

    Cell 178, 1313 (2019).

  7. Scientific Workforce

    Experience versus salary

    1. Melissa McCartney

    Unpaid internships are common in STEM fields, but little is known about the career trajectories of STEM graduates in unpaid versus paid positions. Fournier et al. took data from the U.K. Destination of Leavers from Higher Education survey and compared whether science graduates in paid or unpaid positions 6 months after graduating successfully obtained a high salary or were working in a STEM field 3.5 years later. Results show that unpaid work was strongly associated with persistence in STEM but that there is a negative association between unpaid work and future earnings. Personal connections frequently were used by men and high socioeconomic–status graduates to find unpaid work, raising concerns about the diversity of the unpaid workforce.

    PLOS ONE 14, e0217032 (2019).