Editors' Choice

Science  27 Feb 2015:
Vol. 347, Issue 6225, pp. 961
  1. Exoplanet Detection

    Untangling dips and pulses in starlight

    1. Margaret M. Moerchen

    Five small rocky planets orbit the star Kepler-444

    ILLUSTRATION: TIAGO CAMPANTE/PETER DEVINE

    The menagerie of known exoplanets continues to grow with Kepler data. The NASA spacecraft has monitored stars for brightness dips due to planetary transits, enabling Campante et al. to find five rocky planets orbiting the K star Kepler-444—all between Mercury and Venus in size. Kepler's precise photometry also allowed the team to measure the star's asteroseismic pulsations. A comparison of those values with stellar evolution models revealed an age of 11.2 ± 1.0 billion years, or 80% as old as the universe itself. A planetary system this old (over twice the age of Earth) demonstrates the wide time frame in which Earth-sized planets have existed and helps astronomers discern the earliest times of planet formation.

    Astrophys. J. 10.1088/0004-637X/799/2/170 (2015).

  2. Physics

    Hunting the elusive (quasi)particles

    1. Jelena Stajic

    Majorana fermions, particles that are their own antiparticles, have not yet been observed in nature. There have, however, been several possible sightings of their counterparts in solid-state systems, which may eventually lead to advances in quantum computing. Xu et al. used scanning tunneling microscopy to observe signatures of these Majorana modes in a system consisting of a conventional superconductor with a topological insulator (TI) layer on top of it. The authors observed a distinct change of the experimental signal as the thickness of the TI layer crossed a threshold value, which they interpreted as evidence for the Majorana modes.

    Phys. Rev. Lett. 114, 017001 (2015).

  3. RNA Editing

    Squid are hyper-editors when it comes to RNA

    1. Lisa D. Chong

    The nervous system of squid contains an unusually high amount of edited RNA

    PHOTO: © JEFF ROTMAN/ALAMY

    During RNA editing, specific enzymes alter nucleotides in mRNA transcripts so that the resulting protein differs in amino acid sequence from what was encoded by the original DNA. Such RNA editing is a means to generate greater protein diversity; however, most organisms only use it sparingly. Alon et al., however, now report an exception. They sequenced RNA and DNA from the squid nervous system and discovered that 60% of the transcripts exhibited RNA editing. Such “recoding” occurred largely in genes with cytoskeletal or neuronal functions and may be advantageous to organisms such as squid that must respond quickly and continually to environmental changes.

    eLife 4, e05198 (2015).

  4. Social Science

    Trading growth for happiness

    1. Gilbert Chin

    Muslims pray before breaking fast during the holy month of Ramadan

    PHOTO: © DIVYAKANT SOLANKI/EPA/CORBIS

    Does the dawn-to-dusk fasting practiced by Muslims during the holy month of Ramadan affect labor supply and productivity? The timing of Ramadan follows the lunar calendar, and day length varies with latitude and season; Campante and Yanagizawa-Drott use these sources of exogenous variation to demonstrate that longer fasting results in a lower rate of growth in gross domestic product. They also find that an increase in subjective well-being serves as recompense for what is a costly religious practice, probably via well-established cultural mechanisms that have contributed to the evolution of many prosocial religions, as described by Norenzayan et al.

    Quart. J. Econ. 130, 10.1093/qje/qjv002 (2015); Behav. Brain Sci. 10.1017/S0140525X14001356 (2014).

  5. Proteomics

    The secrets of blood proteins revealed

    1. Laura M. Zahn

    The levels of particular proteins in your blood can provide important insight into your health. However, to what degree environmental factors versus heritability influence the relative abundance of all blood proteins is unknown. To find out, Liu et al. used mass spectrometry on plasma samples collected from monozygotic and dizygotic twins at two different times. They detected 342 unique proteins overall, and although 80 showed evidence of heritability, they found that the expression of many proteins varied widely. Proteins used as clinical biomarkers showed less variability in expression overall; however, some were still quite variable, suggesting that scientists still need to better characterize the predictive value of these blood biomarkers.

    Mol. Syst. Biol. 11, 786 (2015).

  6. Education

    Achievement viewed through a genetic lens

    1. Melissa McCartney

    Why is educational achievement so highly heritable? To investigate, Krapohl et al. used a multivariate analysis to determine how nine broad domains of educational achievement, including intelligence, self-efficacy, personality, well-being, parent-rated behavior problems, child-rated behavior problems, health, perceived school environment, and home environment, contributed to the performance of 6653 pairs of twins on a nationwide exam administered in the United Kingdom at age 16. Results showed that although intelligence was the dominant domain, the other eight domains collectively influenced the heritability of educational achievement at a level equivalent to that of intelligence alone. These results demonstrate that a wide array of heritable factors contributes to academic achievement.

    Proc. Natl. Acad. Sci. U.S.A. 111, 42 (2014).

  7. Receptor Chemistry

    Easier binding the second time around

    1. Jake Yeston

    The hemoglobin protein that shuttles oxygen around our blood manifests a well-known example of cooperative binding: Once one oxygen jumps aboard, the protein conformation shifts to accommodate others more easily. Gan et al. present a synthetic x-shaped receptor complex that similarly binds two oxocarbon anions cooperatively. Spectroscopic monitoring revealed an order-of-magnitude enhancement in binding of the second anion relative to the first. The receptor is held together by cadmium ions, and swapping them out for copper, in conjunction with a solvent switch induced efficient release of both bound guests.

    J. Am. Chem. Soc. 137, 10.1021/ja5120437 (2015).