Massive data collection by businesses and governments calls into question traditional methods for protecting privacy, underpinned by two core principles: (i) notice, that there should be no data collection system whose existence is secret, and (ii) consent, that data collected for one purpose not be used for another without user permission. But notice, designated as a fundamental privacy principle in a different era, makes little sense in situations where collection consists of lots and lots of small amounts of information, whereas consent is no longer realistic, given the complexity and number of decisions that must be made. Thus, efforts to protect privacy by controlling use of data are gaining more attention. I discuss relevant technology, policy, and law, as well as some examples that can illuminate the way. Author: Susan Landau

Despite the attention the right has received, we should not forget that it is just one innovative piece of a comprehensive privacy framework that must be implemented locally and enforced globally. Author: Abraham L. Newman

This Review summarizes and draws connections between diverse streams of empirical research on privacy behavior. We use three themes to connect insights from social and behavioral sciences: people’s uncertainty about the consequences of privacy-related behaviors and their own preferences over those consequences; the context-dependence of people’s concern, or lack thereof, about privacy; and the degree to which privacy concerns are malleable—manipulable by commercial and governmental interests. Organizing our discussion by these themes, we offer observations concerning the role of public policy in the protection of privacy in the information age. Authors: Alessandro Acquisti, Laura Brandimarte, George Loewenstein

The mechanistic basis of eukaryotic circadian oscillators in model systems as diverse as Neurospora, Drosophila, and mammalian cells is thought to be a transcription-and-translation–based negative feedback loop, wherein progressive and controlled phosphorylation of one or more negative elements ultimately elicits their own proteasome-mediated degradation, thereby releasing negative feedback and determining circadian period length. The Neurospora crassa circadian negative element FREQUENCY (FRQ) exemplifies such proteins; it is progressively phosphorylated at more than 100 sites, and strains bearing alleles of frq with anomalous phosphorylation display abnormal stability of FRQ that is well correlated with altered periods or apparent arrhythmicity. Unexpectedly, we unveiled normal circadian oscillations that reflect the allelic state of frq but that persist in the absence of typical degradation of FRQ. This manifest uncoupling of negative element turnover from circadian period length determination is not consistent with the consensus eukaryotic circadian model. Authors: Luis F. Larrondo, Consuelo Olivares-Yañez, Christopher L. Baker, Jennifer J. Loros, Jay C. Dunlap

The fundamental properties and ultimate performance limits of organolead trihalide MAPbX3 (MA = CH3NH3+; X = Br– or I–) perovskites remain obscured by extensive disorder in polycrystalline MAPbX3 films. We report an antisolvent vapor-assisted crystallization approach that enables us to create sizable crack-free MAPbX3 single crystals with volumes exceeding 100 cubic millimeters. These large single crystals enabled a detailed characterization of their optical and charge transport characteristics. We observed exceptionally low trap-state densities on the order of 109 to 1010 per cubic centimeter in MAPbX3 single crystals (comparable to the best photovoltaic-quality silicon) and charge carrier diffusion lengths exceeding 10 micrometers. These results were validated with density functional theory calculations. Authors: Dong Shi, Valerio Adinolfi, Riccardo Comin, Mingjian Yuan, Erkki Alarousu, Andrei Buin, Yin Chen, Sjoerd Hoogland, Alexander Rothenberger, Khabiboulakh Katsiev, Yaroslav Losovyj, Xin Zhang, Peter A. Dowben, Omar F. Mohammed, Edward H. Sargent, Osman M. Bakr

State-of-the-art photovoltaics use high-purity, large-area, wafer-scale single-crystalline semiconductors grown by sophisticated, high-temperature crystal growth processes. We demonstrate a solution-based hot-casting technique to grow continuous, pinhole-free thin films of organometallic perovskites with millimeter-scale crystalline grains. We fabricated planar solar cells with efficiencies approaching 18%, with little cell-to-cell variability. The devices show hysteresis-free photovoltaic response, which had been a fundamental bottleneck for the stable operation of perovskite devices. Characterization and modeling attribute the improved performance to reduced bulk defects and improved charge carrier mobility in large-grain devices. We anticipate that this technique will lead the field toward synthesis of wafer-scale crystalline perovskites, necessary for the fabrication of high-efficiency solar cells, and will be applicable to several other material systems plagued by polydispersity, defects, and grain boundary recombination in solution-processed thin films. Authors: Wanyi Nie, Hsinhan Tsai, Reza Asadpour, Jean-Christophe Blancon, Amanda J. Neukirch, Gautam Gupta, Jared J. Crochet, Manish Chhowalla, Sergei Tretiak, Muhammad A. Alam, Hsing-Lin Wang, Aditya D. Mohite

The death of massive stars is believed to involve aspheric explosions initiated by the collapse of an iron core. The specifics of these catastrophic explosions remain uncertain, due partly to limited observational constraints on asymmetries deep inside the star. Here we present near-infrared observations of the young supernova remnant Cassiopeia A, descendant of a type IIb core-collapse explosion, and a three-dimensional map of its interior unshocked ejecta. The remnant’s interior has a bubble-like morphology that smoothly connects to and helps explain the multiringed structures seen in the remnant's bright reverse-shocked main shell of expanding debris. This internal structure may originate from turbulent mixing processes that encouraged outwardly expanding plumes of radioactive 56Ni-rich ejecta. If this is true, substantial amounts of its decay product, 56Fe, may still reside in these interior cavities. Authors: Dan Milisavljevic, Robert A. Fesen

Solvent-solute interactions influence the mechanisms of chemical reactions in solution, but the response of the solvent is often slower than the reactive event. Here, we report that exothermic reactions of fluorine (F) atoms in d3-acetonitrile and d2-dichloromethane involve efficient energy flow to vibrational motion of the deuterium fluoride (DF) product that competes with dissipation of the energy to the solvent bath, despite strong solvent coupling. Transient infrared absorption spectroscopy and molecular dynamics simulations show that after DF forms its first hydrogen bond on a subpicosecond time scale, DF vibrational relaxation and further solvent restructuring occur over more than 10 picoseconds. Characteristic dynamics of gas-phase F-atom reactions with hydrogen-containing molecules persist in polar organic solvents, and the spectral evolution of the DF products serves as a probe of solvent reorganization induced by a chemical reaction. Authors: G. T. Dunning, D. R. Glowacki, T. J. Preston, S. J. Greaves, G. M. Greetham, I. P. Clark, M. Towrie, J. N. Harvey, A. J. Orr-Ewing

Humans represent numbers along a mental number line (MNL), where smaller values are located on the left and larger on the right. The origin of the MNL and its connections with cultural experience are unclear: Pre-verbal infants and nonhuman species master a variety of numerical abilities, supporting the existence of evolutionary ancient precursor systems. In our experiments, 3-day-old domestic chicks, once familiarized with a target number (5), spontaneously associated a smaller number (2) with the left space and a larger number (8) with the right space. The same number (8), though, was associated with the left space when the target number was 20. Similarly to humans, chicks associate smaller numbers with the left space and larger numbers with the right space. Authors: Rosa Rugani, Giorgio Vallortigara, Konstantinos Priftis, Lucia Regolin

Large-scale data sets of human behavior have the potential to fundamentally transform the way we fight diseases, design cities, or perform research. Metadata, however, contain sensitive information. Understanding the privacy of these data sets is key to their broad use and, ultimately, their impact. We study 3 months of credit card records for 1.1 million people and show that four spatiotemporal points are enough to uniquely reidentify 90% of individuals. We show that knowing the price of a transaction increases the risk of reidentification by 22%, on average. Finally, we show that even data sets that provide coarse information at any or all of the dimensions provide little anonymity and that women are more reidentifiable than men in credit card metadata. Authors: Yves-Alexandre de Montjoye, Laura Radaelli, Vivek Kumar Singh, Alex “Sandy” Pentland

Incoming and outgoing solar radiation couple with heat exchange at Earth’s surface to drive weather patterns that redistribute heat and moisture around the globe, creating an atmospheric heat engine. Here, we investigate the engine’s work output using thermodynamic diagrams computed from reanalyzed observations and from a climate model simulation with anthropogenic forcing. We show that the work output is always less than that of an equivalent Carnot cycle and that it is constrained by the power necessary to maintain the hydrological cycle. In the climate simulation, the hydrological cycle increases more rapidly than the equivalent Carnot cycle. We conclude that the intensification of the hydrological cycle in warmer climates might limit the heat engine’s ability to generate work. Authors: F. Laliberté, J. Zika, L. Mudryk, P. J. Kushner, J. Kjellsson, K. Döös

In optical microscopy, fine structural details are resolved by using refraction to magnify images of a specimen. We discovered that by synthesizing a swellable polymer network within a specimen, it can be physically expanded, resulting in physical magnification. By covalently anchoring specific labels located within the specimen directly to the polymer network, labels spaced closer than the optical diffraction limit can be isotropically separated and optically resolved, a process we call expansion microscopy (ExM). Thus, this process can be used to perform scalable superresolution microscopy with diffraction-limited microscopes. We demonstrate ExM with apparent ~70-nanometer lateral resolution in both cultured cells and brain tissue, performing three-color superresolution imaging of ~107 cubic micrometers of the mouse hippocampus with a conventional confocal microscope. Authors: Fei Chen, Paul W. Tillberg, Edward S. Boyden

Coordinated replication and expression of the mitochondrial genome is critical for metabolically active cells during various stages of development. However, it is not known whether replication and transcription can occur simultaneously without interfering with each other and whether mitochondrial DNA copy number can be regulated by the transcription machinery. We found that interaction of human transcription elongation factor TEFM with mitochondrial RNA polymerase and nascent transcript prevents the generation of replication primers and increases transcription processivity and thereby serves as a molecular switch between replication and transcription, which appear to be mutually exclusive processes in mitochondria. TEFM may allow mitochondria to increase transcription rates and, as a consequence, respiration and adenosine triphosphate production without the need to replicate mitochondrial DNA, as has been observed during spermatogenesis and the early stages of embryogenesis. Authors: Karen Agaronyan, Yaroslav I. Morozov, Michael Anikin, Dmitry Temiakov

Translocator proteins (TSPOs) bind steroids and porphyrins, and they are implicated in many human diseases, for which they serve as biomarkers and therapeutic targets. TSPOs have tryptophan-rich sequences that are highly conserved from bacteria to mammals. Here we report crystal structures for Bacillus cereus TSPO (BcTSPO) down to 1.7 Å resolution, including a complex with the benzodiazepine-like inhibitor PK11195. We also describe BcTSPO-mediated protoporphyrin IX (PpIX) reactions, including catalytic degradation to a previously undescribed heme derivative. We used structure-inspired mutations to investigate reaction mechanisms, and we showed that TSPOs from Xenopus and man have similar PpIX-directed activities. Although TSPOs have been regarded as transporters, the catalytic activity in PpIX degradation suggests physiological importance for TSPOs in protection against oxidative stress. Authors: Youzhong Guo, Ravi C. Kalathur, Qun Liu, Brian Kloss, Renato Bruni, Christopher Ginter, Edda Kloppmann, Burkhard Rost, Wayne A. Hendrickson

The 18-kilodalton translocator protein (TSPO), proposed to be a key player in cholesterol transport into mitochondria, is highly expressed in steroidogenic tissues, metastatic cancer, and inflammatory and neurological diseases such as Alzheimer’s and Parkinson’s. TSPO ligands, including benzodiazepine drugs, are implicated in regulating apoptosis and are extensively used in diagnostic imaging. We report crystal structures (at 1.8, 2.4, and 2.5 angstrom resolution) of TSPO from Rhodobacter sphaeroides and a mutant that mimics the human Ala147→Thr147 polymorphism associated with psychiatric disorders and reduced pregnenolone production. Crystals obtained in the lipidic cubic phase reveal the binding site of an endogenous porphyrin ligand and conformational effects of the mutation. The three crystal structures show the same tightly interacting dimer and provide insights into the controversial physiological role of TSPO and how the mutation affects cholesterol binding. Authors: Fei Li, Jian Liu, Yi Zheng, R. Michael Garavito, Shelagh Ferguson-Miller

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Images from the OSIRIS scientific imaging system onboard Rosetta show that the nucleus of 67P/Churyumov-Gerasimenko consists of two lobes connected by a short neck. The nucleus has a bulk density less than half that of water. Activity at a distance from the Sun of >3 astronomical units is predominantly from the neck, where jets have been seen consistently. The nucleus rotates about the principal axis of momentum. The surface morphology suggests that the removal of larger volumes of material, possibly via explosive release of subsurface pressure or via creation of overhangs by sublimation, may be a major mass loss process. The shape raises the question of whether the two lobes represent a contact binary formed 4.5 billion years ago, or a single body where a gap has evolved via mass loss. Authors: Holger Sierks, Cesare Barbieri, Philippe L. Lamy, Rafael Rodrigo, Detlef Koschny, Hans Rickman, Horst Uwe Keller, Jessica Agarwal, Michael F. A’Hearn, Francesco Angrilli, Anne-Therese Auger, M. Antonella Barucci, Jean-Loup Bertaux, Ivano Bertini, Sebastien Besse, Dennis Bodewits, Claire Capanna, Gabriele Cremonese, Vania Da Deppo, Björn Davidsson, Stefano Debei, Mariolino De Cecco, Francesca Ferri, Sonia Fornasier, Marco Fulle, Robert Gaskell, Lorenza Giacomini, Olivier Groussin, Pablo Gutierrez-Marques, Pedro J. Gutiérrez, Carsten Güttler, Nick Hoekzema, Stubbe F. Hviid, Wing-Huen Ip, Laurent Jorda, Jörg Knollenberg, Gabor Kovacs, J. Rainer Kramm, Ekkehard Kührt, Michael Küppers, Fiorangela La Forgia, Luisa M. Lara, Monica Lazzarin, Cédric Leyrat, Josè J. Lopez Moreno, Sara Magrin, Simone Marchi, Francesco Marzari, Matteo Massironi, Harald Michalik, Richard Moissl, Stefano Mottola, Giampiero Naletto, Nilda Oklay, Maurizio Pajola, Marco Pertile, Frank Preusker, Lola Sabau, Frank Scholten, Colin Snodgrass, Nicolas Thomas, Cecilia Tubiana, Jean-Baptiste Vincent, Klaus-Peter Wenzel, Mirco Zaccariotto, Martin Pätzold

Comets contain the best-preserved material from the beginning of our planetary system. Their nuclei and comae composition reveal clues about physical and chemical conditions during the early solar system when comets formed. ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) onboard the Rosetta spacecraft has measured the coma composition of comet 67P/Churyumov-Gerasimenko with well-sampled time resolution per rotation. Measurements were made over many comet rotation periods and a wide range of latitudes. These measurements show large fluctuations in composition in a heterogeneous coma that has diurnal and possibly seasonal variations in the major outgassing species: water, carbon monoxide, and carbon dioxide. These results indicate a complex coma-nucleus relationship where seasonal variations may be driven by temperature differences just below the comet surface. Authors: M. Hässig, K. Altwegg, H. Balsiger, A. Bar-Nun, J. J. Berthelier, A. Bieler, P. Bochsler, C. Briois, U. Calmonte, M. Combi, J. De Keyser, P. Eberhardt, B. Fiethe, S. A. Fuselier, M. Galand, S. Gasc, T. I. Gombosi, K. C. Hansen, A. Jäckel, H. U. Keller, E. Kopp, A. Korth, E. Kührt, L. Le Roy, U. Mall, B. Marty, O. Mousis, E. Neefs, T. Owen, H. Rème, M. Rubin, T. Sémon, C. Tornow, C.-Y. Tzou, J. H. Waite, P. Wurz

Images of comet 67P/Churyumov-Gerasimenko acquired by the OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System) imaging system onboard the European Space Agency’s Rosetta spacecraft at scales of better than 0.8 meter per pixel show a wide variety of different structures and textures. The data show the importance of airfall, surface dust transport, mass wasting, and insolation weathering for cometary surface evolution, and they offer some support for subsurface fluidization models and mass loss through the ejection of large chunks of material. Authors: Nicolas Thomas, Holger Sierks, Cesare Barbieri, Philippe L. Lamy, Rafael Rodrigo, Hans Rickman, Detlef Koschny, Horst Uwe Keller, Jessica Agarwal, Michael F. A'Hearn, Francesco Angrilli, Anne-Therese Auger, M. Antonella Barucci, Jean-Loup Bertaux, Ivano Bertini, Sebastien Besse, Dennis Bodewits, Gabriele Cremonese, Vania Da Deppo, Björn Davidsson, Mariolino De Cecco, Stefano Debei, Mohamed Ramy El-Maarry, Francesca Ferri, Sonia Fornasier, Marco Fulle, Lorenza Giacomini, Olivier Groussin, Pedro J. Gutierrez, Carsten Güttler, Stubbe F. Hviid, Wing-Huen Ip, Laurent Jorda, Jörg Knollenberg, J.-Rainer Kramm, Ekkehard Kührt, Michael Küppers, Fiorangela La Forgia, Luisa M. Lara, Monica Lazzarin, Josè J. Lopez Moreno, Sara Magrin, Simone Marchi, Francesco Marzari, Matteo Massironi, Harald Michalik, Richard Moissl, Stefano Mottola, Giampiero Naletto, Nilda Oklay, Maurizio Pajola, Antoine Pommerol, Frank Preusker, Lola Sabau, Frank Scholten, Colin Snodgrass, Cecilia Tubiana, Jean-Baptiste Vincent, Klaus-Peter Wenzel

Heat transport and ice sublimation in comets are interrelated processes reflecting properties acquired at the time of formation and during subsequent evolution. The Microwave Instrument on the Rosetta Orbiter (MIRO) acquired maps of the subsurface temperature of comet 67P/Churyumov-Gerasimenko, at 1.6 mm and 0.5 mm wavelengths, and spectra of water vapor. The total H2O production rate varied from 0.3 kg s–1 in early June 2014 to 1.2 kg s–1 in late August and showed periodic variations related to nucleus rotation and shape. Water outgassing was localized to the “neck” region of the comet. Subsurface temperatures showed seasonal and diurnal variations, which indicated that the submillimeter radiation originated at depths comparable to the diurnal thermal skin depth. A low thermal inertia (~10 to 50 J K–1 m–2 s–0.5), consistent with a thermally insulating powdered surface, is inferred. Authors: Samuel Gulkis, Mark Allen, Paul von Allmen, Gerard Beaudin, Nicolas Biver, Dominique Bockelée-Morvan, Mathieu Choukroun, Jacques Crovisier, Björn J. R. Davidsson, Pierre Encrenaz, Therese Encrenaz, Margaret Frerking, Paul Hartogh, Mark Hofstadter, Wing-Huen Ip, Michael Janssen, Christopher Jarchow, Stephen Keihm, Seungwon Lee, Emmanuel Lellouch, Cedric Leyrat, Ladislav Rezac, F. Peter Schloerb, Thomas Spilker

The VIRTIS (Visible, Infrared and Thermal Imaging Spectrometer) instrument on board the Rosetta spacecraft has provided evidence of carbon-bearing compounds on the nucleus of the comet 67P/Churyumov-Gerasimenko. The very low reflectance of the nucleus (normal albedo of 0.060 ± 0.003 at 0.55 micrometers), the spectral slopes in visible and infrared ranges (5 to 25 and 1.5 to 5% kÅ−1), and the broad absorption feature in the 2.9-to-3.6–micrometer range present across the entire illuminated surface are compatible with opaque minerals associated with nonvolatile organic macromolecular materials: a complex mixture of various types of carbon-hydrogen and/or oxygen-hydrogen chemical groups, with little contribution of nitrogen-hydrogen groups. In active areas, the changes in spectral slope and absorption feature width may suggest small amounts of water-ice. However, no ice-rich patches are observed, indicating a generally dehydrated nature for the surface currently illuminated by the Sun. Authors: F. Capaccioni, A. Coradini, G. Filacchione, S. Erard, G. Arnold, P. Drossart, M. C. De Sanctis, D. Bockelee-Morvan, M. T. Capria, F. Tosi, C. Leyrat, B. Schmitt, E. Quirico, P. Cerroni, V. Mennella, A. Raponi, M. Ciarniello, T. McCord, L. Moroz, E. Palomba, E. Ammannito, M. A. Barucci, G. Bellucci, J. Benkhoff, J. P. Bibring, A. Blanco, M. Blecka, R. Carlson, U. Carsenty, L. Colangeli, M. Combes, M. Combi, J. Crovisier, T. Encrenaz, C. Federico, U. Fink, S. Fonti, W. H. Ip, P. Irwin, R. Jaumann, E. Kuehrt, Y. Langevin, G. Magni, S. Mottola, V. Orofino, P. Palumbo, G. Piccioni, U. Schade, F. Taylor, D. Tiphene, G. P. Tozzi, P. Beck, N. Biver, L. Bonal, J.-Ph. Combe, D. Despan, E. Flamini, S. Fornasier, A. Frigeri, D. Grassi, M. Gudipati, A. Longobardo, K. Markus, F. Merlin, R. Orosei, G. Rinaldi, K. Stephan, M. Cartacci, A. Cicchetti, S. Giuppi, Y. Hello, F. Henry, S. Jacquinod, R. Noschese, G. Peter, R. Politi, J. M. Reess, A. Semery

The provenance of water and organic compounds on Earth and other terrestrial planets has been discussed for a long time without reaching a consensus. One of the best means to distinguish between different scenarios is by determining the deuterium-to-hydrogen (D/H) ratios in the reservoirs for comets and Earth’s oceans. Here, we report the direct in situ measurement of the D/H ratio in the Jupiter family comet 67P/Churyumov-Gerasimenko by the ROSINA mass spectrometer aboard the European Space Agency’s Rosetta spacecraft, which is found to be (5.3 ± 0.7) × 10−4—that is, approximately three times the terrestrial value. Previous cometary measurements and our new finding suggest a wide range of D/H ratios in the water within Jupiter family objects and preclude the idea that this reservoir is solely composed of Earth ocean–like water. Authors: K. Altwegg, H. Balsiger, A. Bar-Nun, J. J. Berthelier, A. Bieler, P. Bochsler, C. Briois, U. Calmonte, M. Combi, J. De Keyser, P. Eberhardt, B. Fiethe, S. Fuselier, S. Gasc, T. I. Gombosi, K.C. Hansen, M. Hässig, A. Jäckel, E. Kopp, A. Korth, L. LeRoy, U. Mall, B. Marty, O. Mousis, E. Neefs, T. Owen, H. Rème, M. Rubin, T. Sémon, C.-Y. Tzou, H. Waite, P. Wurz

The Rosetta mission shall accompany comet 67P/Churyumov-Gerasimenko from a heliocentric distance of >3.6 astronomical units through perihelion passage at 1.25 astronomical units, spanning low and maximum activity levels. Initially, the solar wind permeates the thin comet atmosphere formed from sublimation, until the size and plasma pressure of the ionized atmosphere define its boundaries: A magnetosphere is born. Using the Rosetta Plasma Consortium ion composition analyzer, we trace the evolution from the first detection of water ions to when the atmosphere begins repelling the solar wind (~3.3 astronomical units), and we report the spatial structure of this early interaction. The near-comet water population comprises accelerated ions (<800 electron volts), produced upstream of Rosetta, and lower energy locally produced ions; we estimate the fluxes of both ion species and energetic neutral atoms. Authors: Hans Nilsson, Gabriella Stenberg Wieser, Etienne Behar, Cyril Simon Wedlund, Herbert Gunell, Masatoshi Yamauchi, Rickard Lundin, Stas Barabash, Martin Wieser, Chris Carr, Emanuele Cupido, James L. Burch, Andrei Fedorov, Jean-André Sauvaud, Hannu Koskinen, Esa Kallio, Jean-Pierre Lebreton, Anders Eriksson, Niklas Edberg, Raymond Goldstein, Pierre Henri, Christoph Koenders, Prachet Mokashi, Zoltan Nemeth, Ingo Richter, Karoly Szego, Martin Volwerk, Claire Vallat, Martin Rubin

Authors: Alessandra Rotundi, Holger Sierks, Vincenzo Della Corte, Marco Fulle, Pedro J. Gutierrez, Luisa Lara, Cesare Barbieri, Philippe L. Lamy, Rafael Rodrigo, Detlef Koschny, Hans Rickman, Horst Uwe Keller, José J. López-Moreno, Mario Accolla, Jessica Agarwal, Michael F. A’Hearn, Nicolas Altobelli, Francesco Angrilli, M. Antonietta Barucci, Jean-Loup Bertaux, Ivano Bertini, Dennis Bodewits, Ezio Bussoletti, Luigi Colangeli, Massimo Cosi, Gabriele Cremonese, Jean-Francois Crifo, Vania Da Deppo, Björn Davidsson, Stefano Debei, Mariolino De Cecco, Francesca Esposito, Marco Ferrari, Sonia Fornasier, Frank Giovane, Bo Gustafson, Simon F. Green, Olivier Groussin, Eberhard Grün, Carsten Güttler, Miguel L. Herranz, Stubbe F. Hviid, Wing Ip, Stavro Ivanovski, José M. Jerónimo, Laurent Jorda, Joerg Knollenberg, Rainer Kramm, Ekkehard Kührt, Michael Küppers, Monica Lazzarin, Mark R. Leese, Antonio C. López-Jiménez, Francesca Lucarelli, Stephen C. Lowry, Francesco Marzari, Elena Mazzotta Epifani, J. Anthony M. McDonnell, Vito Mennella, Harald Michalik, Antonio Molina, Rafael Morales, Fernando Moreno, Stefano Mottola, Giampiero Naletto, Nilda Oklay, José L. Ortiz, Ernesto Palomba, Pasquale Palumbo, Jean-Marie Perrin, Julio Rodríguez, Lola Sabau, Colin Snodgrass, Roberto Sordini, Nicolas Thomas, Cecilia Tubiana, Jean-Baptiste Vincent, Paul Weissman, Klaus-Peter Wenzel, Vladimir Zakharov, John C. Zarnecki

At the end of 2014, construction began on the Grand Canal in Nicaragua, a project shrouded in secrecy since its inception 2.5 years ago. The Nicaraguan government showed scant evidence of having accounted for the impact on the environment and on local residents, or of having adequately consulted the public in selecting the final 278-km route. Such disregard should be alarming to everyone. Projects of this magnitude warrant dialogue among all stakeholders. As construction is projected to span 5 years, there is still time to reconsider it and convene independent assessments and meetings that are transparent, inclusive, and respectful of different perspectives, to guide the project toward the best outcome. Authors: Jorge A. Huete-Perez, Axel Meyer, Pedro J. Alvarez

In science news around the world, a federal judge rules that BP spilled 3.19 million barrels of oil into the Gulf of Mexico during the 2010 Deepwater Horizon disaster, NASA's Mars Reconnaissance Orbiter spots the long-lost Beagle 2 probe on the Red Planet, Australian environmentalists take the country's environment minister to court over his approval last year of a coal mine, the U.S. National Institute of General Medical Sciences imposes a one-grant limit on scientists who already have plentiful support, and the Next-Generation Transit Survey observatory in Chile gains first light. Also, a grassroots plan to save monarch butterflies by planting milkweed backfires. And a veteran Indian space engineer is tapped to head the Indian Space Research Organisation.

When Europe's Rosetta spacecraft started studying comet 67P/Churyumov-Gerasimenko late in 2014, some scientists feared the comet might turn out to be a boring lump of ice and dust. They needn't have worried. Papers in this issue of Science show that 67P is pocked with pits, incised by cracks and cliffs, and decorated with ripples and flows of dust—all signs of an extraordinarily active place. Many of the intriguing landforms testify to the power of the sun, which heats up 67P during part of every orbit, igniting jets of gas and dust that resculpt the surface of the comet. Other discoveries could be primordial, dating from the comet's formation more than 4.5 billion years ago. Mission scientists say the complexity of the comet suggests that the comet-forming regions of the early solar system were more turbulent and chemically diverse than theorists have thought. Author: Eric Hand

A slew of new surveys are illuminating demographics in insecure Afghanistan, after decades in which many key population indicators were a mystery. The Socio-Demographic and Economic Survey, a province-by-province count of households carried out by the Afghan Central Statistics Organization with assistance from the United Nations Population Fund, is now under way, and plans for still more ambitious surveys are being rolled out as well. Such projects follow on more limited assessments of fertility, mortality, and other factors. Worsening security concerns are an issue; surveyors now routinely avoid Taliban-controlled parts of the rural south. But even partial results are a boon to researchers, government officials, and aid agencies once starved for data. Author: Mara Hvistendahl

Later this spring, Japan is likely to restart the first two of the 48 nuclear reactors idled in the aftermath of the 2011 meltdowns at the Fukushima Daiichi Nuclear Power Station. But the resumption of nuclear power generation is refocusing attention on a lingering challenge: what to do with the spent fuel. When Japan turned to nuclear power in the 1960s, it worried about uranium supplies and wanted to minimize the amount of nuclear waste. So it planned on spent fuel reprocessing, which reduces the volume of waste needing long-term storage and produces fresh fuel for reactors. A private firm owned by the country's nuclear utilities started building a reprocessing plant in the northern village of Rokkasho in 1993. But it took more than 2 decades to work the kinks out of an experimental vitrification process. The plant is finally due to come online in spring 2016. But the country is still searching for a site for a deep underground repository for the highly radioactive nuclear waste left over from reprocessing. For the time being, it will be encased in glass and stored until a permanent solution is found. Author: Dennis Normile

Malaria is a scourge of humankind, but many birds seem to shrug it off. Although they are chronically infected with malaria parasites, their behavior seems unaffected, and they mostly reproduce and raise young just as well as noninfected birds. That was a puzzle not just for ornithologists but also for evolutionary biologists, who have long theorized that parasites inevitably take a toll on fitness. The birds' healthy appearance turns out to be deceiving, however. Drawing on data from a 3-decade study of great reed warblers in southern Sweden, researchers report this week in Science that long-term infection with malaria significantly shortened the birds' lives. The analysis also revealed a possible explanation: The blood cells of infected birds also had shorter telomeres, stretches of DNA that cap the ends of chromosomes and protect them during cell division. In many species, shorter telomeres are associated with aging and shorter life span. The shorter lives had a steep cost when it came to reproduction: lost breeding opportunities. On average, uninfected birds raised more than eight offspring to fledglings, infected birds just four. Author: Gretchen Vogel