Editors' Choice

Science  04 Nov 2016:
Vol. 354, Issue 6312, pp. 594
  1. Public Health

    Worms remodel immune responsiveness

    1. Caroline Ash

    Ascaris lumbricoides is a common parasite of humans.

    PHOTO: EYE OF SCIENCE/SCIENCE SOURCE

    Rural populations in less developed countries commonly show poor immunogenicity in vaccination programs. Helminth infestations remain common in some rural areas, and cellular immune hyporesponsiveness is a hallmark of chronic helminth infections. Community deworming programs are in general believed to be a good thing to reverse the morbidity that a large worm burden can impose on children. Wammes et al. set up a 2-year clinical trial to systematically test the immunological consequences of deworming in >1000 villagers in Indonesia. After treatment, subjects showed significant immune remodeling, with reduced expression of CTLA-4 (cytotoxin T lymphocyte–associated antigen 4) and elevated proinflammatory cytokine responses to malaria parasite antigens. The challenge in the longer term could be that restored immune responsiveness might increase the prevalence of inflammatory diseases.

    Proc. Nat. Acad. Sci. 10.1073/pnas.1604570113 (2016).

  2. Porous Materials

    Printing emulsions and foams in 3D

    1. Marc S. Lavine

    A printed cubic lattice scaffold for the creation of porous ceramics

    PHOTO: MINAS ET AL., MATERIAL VIEWS (10 AUGUST 2016) ©2016

    The properties of porous materials can depend on the overall volume, size, and size distribution of the pores, but these can be difficult features to simultaneously control during fabrication. Emulsion or foam techniques can produce pores of only one narrow size range, but in combination with a direct ink-writing process, Minas et al. developed an approach to create porous materials with highly tunable properties. Shear thinning inks made from modified alumina particles are progressively deposited to form an overall structure, where large pores are made by the writing process and small ones from the emulsion or foam, with pores either open or closed. A percolating network of load-bearing struts results in structures with very high strength-to-weight ratios.

    Adv. Mater. 10.1002/adma.201603390 (2016).

  3. Neuroscience

    Cognition, behavior, and the globus pallidus

    1. Peter Stern

    Deep inside the brain, the external segment of the globus pallidus receives many inputs from the neighboring basal ganglia. Its role in basic cognitive functions has rarely been measured directly. While monkeys were learning a complex task, Schechtman et al. recorded discharges from prototypical neurons in the structure. The animals had to switch to a new stimulus-reward association once a predefined learning criterion had been reached. The activity of the neurons predicted whether the monkeys would change or maintain their previous stimulus choice. Neuronal spike activity also encoded whether such choices were successful. When the animals' performance became more automated and less demanding, discharge rates in the context of choice selection decreased.

    Proc. Nat. Acad. Sci. 10.1073/pnas.1612392113 (2016).

  4. Cell Biology

    Microtubule repair and rescue

    1. Sarah Harrison,
    2. Stella M. Hurtley

    The microtubule network that forms the cytoskeleton is essential for cell polarization and migration. Microtubules tend to grow slowly, and they can shrink rapidly in a process known as catastrophe. Aumeier et al. report that where the network is dense, microtubules bend and cross over, leading to increased mechanical stress and filament damage. Damaged filaments can self-repair in a process that also prevents complete depolymerization. Most of the tubulin incorporates into the growing ends of microtubules, but some incorporates along the shaft of preexisting microtubules at damaged regions. This repair-and-rescue mechanism provides insight into how the network can remain stable in this highly dynamic system.

    Nat. Cell Biol. 18, 1054 (2016).

  5. Chemistry

    Sourcing hydrogen directly from wax

    1. Jake Yeston

    Hydrogen is an appealing fuel because of the energy released in its reaction with oxygen and the nearly ideal safety profile of the sole product, water. The challenge lies in transporting and storing the hydrogen before its use. Gonzalez-Cortes et al. now show that simple paraffin wax can be an efficient source of hydrogen under the right circumstances. Specifically, they embedded carbon-supported ruthenium nanoparticles in the wax and then irradiated it with microwaves, thereby releasing up to half of the available gravimetric hydrogen content. The authors attribute the catalytic efficiency to a possible combination of local superheating and field-induced plasma formation.

    Sci. Rep. 10.1038/srep35315 (2016).

  6. Education

    What a (scientific) argument is not

    1. Melissa McCartney

    Engaging in arguments based on evidence is a practice found in STEM (science, technology, engineering, and mathematics) education frameworks. Are students being taught to argue evidence in the same way that professional scientists do? MacPherson interviewed 10 ecologists about arguments both current and ongoing in their field. These data were compared to ecological arguments portrayed in assessment tasks written for middle and high school science students. Ecologists discussed causal claims, whereas school science tasks instead focused on descriptive and prescriptive claims. This mismatch results in students not receiving an accurate picture of how professional ecologists argue. How can the STEM education community move forward with designing tasks that ask students to critique evidence in a truly scientific way?

    Sci. Ed. 10.1002/sce.21246 (2016).

  7. Neurodevelopment

    Layered haircut underlies hearing

    1. Pamela J. Hines

    Inner-ear sensory hair cells are specifically organized.

    PHOTO: SUSUMU NISHINAGA/SCIENCE SOURCE

    Hair cells deep within the ear transduce sound into hearing. On any single hair cell, a pack of stereocilia is neatly arranged from tallest to shortest. When the stereocilia do not develop adequately, deafness ensues. Studying mice, Tarchini et al. discovered some of the key signaling components that organize stereocilia during development. Two regulators of G proteins, the leucine-glycine-asparagine repeat protein and an inhibitory α-subunit of heterotrimeric G protein, coordinate to define the tallest row of stereocilia. Both regulators are expressed in the bare zone of the hair cell, a surface domain that will not produce stereocilia, and also in the very tips of the row of stereocilia adjacent to the bare zone. These stereocilia will emerge as the tallest of the crowd. If this signaling pathway is disrupted, stereocilia develop to more even and modest heights, and the animal is deaf.

    Development 10.1242/dev.139089 (2016).