Editors' Choice

Science  28 Sep 2018:
Vol. 361, Issue 6409, pp. 1351
  1. Archaeology

    A massive cemetery at Lake Turkana

    1. Andrew M. Sugden

    A view of Lothagam North Pillar, Kenya, built by eastern Africa's earliest herders ∼5000 to 4300 years ago

    PHOTO: KATHERINE GRILLO

    The oldest monumental architecture in eastern Africa was built about 5000 years ago. Apparently, these are commemorative structures built by pastoralists. Hildebrand et al. report a detailed excavation and ground-penetrating radar survey at the Lothagam North Pillar Site in Kenya. A massive mortuary was revealed, containing the skeletal remains of nearly 600 individuals buried over several centuries. Associated personal ornamentation included beads, colored stone, tusks, and a headpiece with over 400 teeth from more than 100 gerbils. There appeared to be no differentiation by hierarchy, gender, or age. The authors suggest that this site and others like it would have been stable landmarks at which mobile communities could gather and interact.

    Proc. Natl. Acad. Sci. U.S.A. 115, 8942 (2018).

  2. Stem Cells

    The blood, by night and day

    1. Beverly A. Purnell

    Many developmental events have now been associated with the daily cycle. But what is happening physiologically during the hours of light and dark? Bone turnover, immunity, and stem cell migration from the bone marrow are certainly affected. Golan et al. observed two peaks in bone marrow hematopoietic stem and progenitor cells (HSPCs) after transient increases of norepinephrine and tumor necrosis factor. The nighttime peak increases melatonin secretion to maintain and replenish HSPCs and to reduce differentiation. By contrast, the morning peak increases differentiation and vascular permeability for blood replenishment. Hence, light and dark provide different signals that are crucial for blood cell activity and overall health.

    Cell Stem Cell 10.1016/j.stem.2018.08.002 (2018).

  3. Evolution

    Father, do not eat thy son

    1. Caroline Ash

    Rhabdoblennius nitidus males destroy their eggs to reset fertility.

    PHOTO: AFLO RELAX/MASTERFILE

    Being a parent is costly in many ways. In hard times, some animal parents resort to desertion, abortion, or even cannibalism. Such behaviors may allow adults to regain energy reserves and bank them for reproduction under more favorable conditions. Matsumoto et al. studied filial cannibalism in caregiving male blennies (Rhabdoblennius nitidus). These fish cannot court additional females while guarding eggs because their androgen supplies are suppressed by the presence of the eggs. Hormone synthesis only resumes in the fathers when all the eggs are removed, but not necessarily eaten, from a blenny's nest. Thus, the blennies eschew cannibalism in favor of infanticide to rapidly reset their reproductive physiology. In this way, they gain another chance at courtship and potentially a bigger clutch of eggs.

    Curr. Biol. 28, 2831 (2018).

  4. Workforce Population

    Connecting the bio to the tech

    1. Melissa McCartney

    With so many investments being made in training current STEM students to enter a 21st-century job market, why are some biotech companies struggling to fill entry-level positions? Thompson et al. surveyed academic and industry stakeholders and found disconnects on several levels. On the university side, faculty and career counselors are unfamiliar with the career opportunities, partly because biotech companies have done a relatively poor job of marketing entry-level careers. Several obstacles limiting the placement of STEM graduates arise from this, including students not being job ready at graduation and students pursuing education beyond what is needed, leaving them overqualified. The authors make recommendations for encouraging and implementing partnerships among academia, industry, government agencies, and undergraduate institutions as a way forward.

    CBE Life Sci. Educ. 17, es12 (2018).

  5. Plasmonics

    Controlling gold helices with DNA

    1. Phil Szuromi

    The plasmonic properties of gold nanoparticles can be exploited by creating arrays that control their spacing and orientation to induce chiral optical properties. Lan et al. attached gold nanorods to V-shaped hinged DNA origami structures, thereby allowing the DNA origami to self-assemble along their edges and create staircase helical structures. By interchanging the spacer that sets the hinge angle of the V with a longer spacer, they converted the helix into an extended structure with a different circular-dichroism spectrum. Alternatively, the authors show that a fixed spacer can be used and additional DNA strands attached at the hinge and at the ends of the V structures. These strands could then be reversibly displaced by ones that cause the helix to switch handedness.

    J. Am. Chem. Soc. 140, 11763 (2018).

  6. Science Learning

    Better communication without politics

    1. Barbara R. Jasny

    How can preconceived beliefs be overcome so that people can avoid misperceptions about climate change? Guilbeault et al. developed an experimental system in which 2400 conservative and liberal individuals were placed into networks with either no cues as to the political orientation of other participants or visible designations. Groups were asked to interpret a graph showing trends in Arctic sea ice. At first, nearly 40% of conservatives incorrectly interpreted the data, saying that amounts of Arctic sea ice would be increasing by 2025; 26% of liberals made the same mistake. After network interactions in the absence of political identifiers, more than 85% of individuals of either ideology correctly saw the trend toward decreasing Arctic sea ice. Knowledge of the political identification or affiliation of others prevented social learning.

    Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1722664115 (2018).

  7. Longevity

    Fasting to improve health span

    1. Gemma Alderton

    Patterns of eating, as well as caloric content, are important determinants of health span. Mitchell et al. investigated how dietary composition and feeding patterns influence longevity in a large cohort of mice over 54 weeks. Caloric restriction (a 30% reduction in daily intake) or single-meal feeding (resulting in fasting during each day but no caloric restriction) increased life span and delayed the onset of age-associated pathologies in mice compared with ad libitum feeding. It is possible that daily fasting, even without caloric restriction, may improve health span in humans.

    Cell Metab. 10.1016/j.cmet.2018.08.011 (2018).