ALBERT

Description: 〈p〉Malaria parasites adopt a remarkable variety of morphological life stages as they transition through multiple mammalian host and mosquito vector environments. We profiled the single-cell transcriptomes of thousands of individual parasites, deriving the first high-resolution transcriptional atlas of the entire 〈i〉Plasmodium berghei〈/i〉 life cycle. We then used our atlas to precisely define developmental stages of single cells from three different human malaria parasite species, including parasites isolated directly from infected individuals. The Malaria Cell Atlas provides both a comprehensive view of gene usage in a eukaryotic parasite and an open-access reference dataset for the study of malaria parasites.〈/p〉

Description: Columbus crater in the Terra Sirenum region of the Martian southern highlands contains light-toned layered deposits with interbedded sulfate and phyllosilicate minerals, a rare occurrence on Mars. Here we investigate in detail the morphology, thermophysical properties, mineralogy, and stratigraphy of these deposits; explore their regional context; and interpret the crater's aqueous history. Hydrated mineral-bearing deposits occupy a discrete ring around the walls of Columbus crater and are also exposed beneath younger materials, possibly lava flows, on its floor. Widespread minerals identified in the crater include gypsum, polyhydrated and monohydrated Mg/Fe-sulfates, and kaolinite; localized deposits consistent with montmorillonite, Fe/Mg-phyllosilicates, jarosite, alunite, and crystalline ferric oxide or hydroxide are also detected. Thermal emission spectra suggest abundances of these minerals in the tens of percent range. Other craters in northwest Terra Sirenum also contain layered deposits and Al/Fe/Mg-phyllosilicates, but sulfates have so far been found only in Columbus and Cross craters. The region's intercrater plains contain scattered exposures of Al-phyllosilicates and one isolated mound with opaline silica, in addition to more common Fe/Mg-phyllosilicates with chlorides. A Late Noachian age is estimated for the aqueous deposits in Columbus, coinciding with a period of inferred groundwater upwelling and evaporation, which (according to model results reported here) could have formed evaporites in Columbus and other craters in Terra Sirenum. Hypotheses for the origin of these deposits include groundwater cementation of crater-filling sediments and/or direct precipitation from subaerial springs or in a deep (∼900 m) paleolake. Especially under the deep lake scenario, which we prefer, chemical gradients in Columbus crater may have created a habitable environment at this location on early Mars.

Description: We show here that transtensional rifting along the eastern boundary of the Sierra Nevada microplate (Walker Lane rift) began by ca. 12 Ma in the central Sierra Nevada (USA), within the ancestral Cascades arc, triggering voluminous high-K intermediate volcanism (Stanislaus Group). Flood andesite (i.e., unusually large-volume effusive eruptions of intermediate composition) lavas erupted from fault-controlled fissures within a series of grabens that we refer to as the Sierra Crest graben-vent system. This graben-vent system includes the following. 1. The north-northwest–south-southeast Sierra Crest graben proper consists of a single 28-km-long, 8–10-km-wide full graben that is along the modern Sierra Nevada crest between Sonora Pass and Ebbetts Pass (largely in the Carson-Iceberg Wilderness). This contains fissure vents for the high-K intermediate lavas. 2. A series of north-northwest-south-southeast half-grabens on the western margin of the full graben, which progressively disrupted an ancient Nevadaplano paleochannel that contains the type section of Stanislaus Group (Red Peak–Bald Peak area). These Miocene half-grabens are as much as 15 km west of the modern Sierra Nevada crest, and vented high-K lavas from point sources. 3. Series of northeast-southwest grabens define a major transfer zone along the northeast side of the Sierra Crest graben. These extend as much as ~30 km from the modern range crest down the modern Sierra Nevada range front, in a zone ~30 km wide, and vented high-K lavas and tuffs of the Stanislaus Group from point sources. Range-front north-south and northeast-southwest faults to the south of that, along the southeast side of the Sierra Crest graben, did not vent volcanic rocks (although they ponded them); those will be described elsewhere. We present evidence for a dextral component of slip on the north-northwest–south-southeast normal faults, and a sinistral component of slip on the northeast-southwest normal faults. The onset of transtension immediately preceded the high-K volcanism (within the analytical error of 40 Ar/ 39 Ar dates), and triggered the deposition of a debris avalanche deposit with a preserved volume of ~50 km 3 . The grabens are mainly filled with high-K lava flows, ponded to thicknesses of as much as 400 m; this effusive volcanism culminated in the development of the Little Walker caldera over a relatively small part of the field. Trachydacite outflow ignimbrites from the caldera also became ponded in the larger graben-vent complex, where they interfingered with high-K lavas vented there, and escaped the graben-vent complex on its west margin to flow westward down two paleochannels to the western foothills. The Sierra Crest graben-vent system is spectacularly well exposed at the perfect structural level for viewing the controls of synvolcanic faults on the siting and styles of feeders, vents, and graben fills under a transtensional strain regime in an arc volcanic field.

Description: To examine the problem of how far coral larvae disperse from their natal reef, coral recruitment densities were experimentally determined at distances up to 5 kilometers from a small, relatively isolated platform reef, Helix Reef, on the central Great Barrier Reef for 7 months. High concentrations of recruits, accounting for up to 40 percent of all recruitment, were found downstream of the reef in areas of high water residence time, suggesting that near-field(proximal) circulation has a profound influence on dispersal and recruitment of coral larvae. Coral recruitment declined logarithmically with distance from the reef, decreasing by an order of magnitude at radial distances of only 600 to 1200 meters. On an ecological time scale, advective dispersal of semipassive marine larvae with relatively short planktonic lives(minimally days) may be extensive, but success of recruitment is highly limited. Through evolutionary time, sufficient dispersal occurs to ensure gene flow to reef tracts hundreds or possibly thousands of kilometers apart. In the short term, however, coral reefs appear to be primarily self-seeded with respect to coral larvae.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sammarco, P W -- Andrews, J C -- New York, N.Y. -- Science. 1988 Mar 18;239(4846):1422-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17769738" target="_blank"〉PubMed〈/a〉

Description: The most prominent feature on the surface of Mars is the near-hemispheric dichotomy between the southern highlands and northern lowlands. The root of this dichotomy is a change in crustal thickness along an apparently irregular boundary, which can be traced around the planet, except where it is presumably buried beneath the Tharsis volcanic rise. The isostatic compensation of these distinct provinces and the ancient population of impact craters buried beneath the young lowlands surface suggest that the dichotomy is one of the most ancient features on the planet. However, the origin of this dichotomy has remained uncertain, with little evidence to distinguish between the suggested causes: a giant impact or mantle convection/overturn. Here we use the gravity and topography of Mars to constrain the location of the dichotomy boundary beneath Tharsis, taking advantage of the different modes of compensation for Tharsis and the dichotomy to separate their effects. We find that the dichotomy boundary along its entire path around the planet is accurately fitted by an ellipse measuring approximately 10,600 by 8,500 km, centred at 67 degrees N, 208 degrees E. We suggest that the elliptical nature of the crustal dichotomy is most simply explained by a giant impact, representing the largest such structure thus far identified in the Solar System.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Andrews-Hanna, Jeffrey C -- Zuber, Maria T -- Banerdt, W Bruce -- England -- Nature. 2008 Jun 26;453(7199):1212-5. doi: 10.1038/nature07011.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. jhanna@mit.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18580944" target="_blank"〉PubMed〈/a〉

Description: Both poles of Mars are hidden beneath caps of layered ice. We calculated the density of the south polar layered deposits by combining the gravity field obtained from initial results of radio tracking of the Mars Reconnaissance Orbiter with existing surface topography from the Mars Orbiter Laser Altimeter on the Mars Global Surveyor spacecraft and basal topography from the Mars Advanced Radar for Subsurface and Ionospheric Sounding on the Mars Express spacecraft. The results indicate a best-fit density of 1220 kilograms per cubic meter, which is consistent with water ice that has approximately 15% admixed dust. The results demonstrate that the deposits are probably composed of relatively clean water ice and also refine the martian surface-water inventory.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zuber, Maria T -- Phillips, Roger J -- Andrews-Hanna, Jeffrey C -- Asmar, Sami W -- Konopliv, Alexander S -- Lemoine, Frank G -- Plaut, Jeffrey J -- Smith, David E -- Smrekar, Suzanne E -- New York, N.Y. -- Science. 2007 Sep 21;317(5845):1718-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA. zuber@mit.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/17885129" target="_blank"〉PubMed〈/a〉

Description: High-resolution gravity data obtained from the dual Gravity Recovery and Interior Laboratory (GRAIL) spacecraft show that the bulk density of the Moon's highlands crust is 2550 kilograms per cubic meter, substantially lower than generally assumed. When combined with remote sensing and sample data, this density implies an average crustal porosity of 12% to depths of at least a few kilometers. Lateral variations in crustal porosity correlate with the largest impact basins, whereas lateral variations in crustal density correlate with crustal composition. The low-bulk crustal density allows construction of a global crustal thickness model that satisfies the Apollo seismic constraints, and with an average crustal thickness between 34 and 43 kilometers, the bulk refractory element composition of the Moon is not required to be enriched with respect to that of Earth.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wieczorek, Mark A -- Neumann, Gregory A -- Nimmo, Francis -- Kiefer, Walter S -- Taylor, G Jeffrey -- Melosh, H Jay -- Phillips, Roger J -- Solomon, Sean C -- Andrews-Hanna, Jeffrey C -- Asmar, Sami W -- Konopliv, Alexander S -- Lemoine, Frank G -- Smith, David E -- Watkins, Michael M -- Williams, James G -- Zuber, Maria T -- New York, N.Y. -- Science. 2013 Feb 8;339(6120):671-5. doi: 10.1126/science.1231530. Epub 2012 Dec 5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut de Physique du Globe de Paris, Sorbonne Paris Cite, Universite Paris Diderot, Case 7071, Lamarck A, 5, rue Thomas Mann, 75205 Paris Cedex 13, France. wieczor@ipgp.fr〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23223394" target="_blank"〉PubMed〈/a〉

Description: The Procellarum region is a broad area on the nearside of the Moon that is characterized by low elevations, thin crust, and high surface concentrations of the heat-producing elements uranium, thorium, and potassium. The region has been interpreted as an ancient impact basin approximately 3,200 kilometres in diameter, although supporting evidence at the surface would have been largely obscured as a result of the great antiquity and poor preservation of any diagnostic features. Here we use data from the Gravity Recovery and Interior Laboratory (GRAIL) mission to examine the subsurface structure of Procellarum. The Bouguer gravity anomalies and gravity gradients reveal a pattern of narrow linear anomalies that border Procellarum and are interpreted to be the frozen remnants of lava-filled rifts and the underlying feeder dykes that served as the magma plumbing system for much of the nearside mare volcanism. The discontinuous surface structures that were earlier interpreted as remnants of an impact basin rim are shown in GRAIL data to be a part of this continuous set of border structures in a quasi-rectangular pattern with angular intersections, contrary to the expected circular or elliptical shape of an impact basin. The spatial pattern of magmatic-tectonic structures bounding Procellarum is consistent with their formation in response to thermal stresses produced by the differential cooling of the province relative to its surroundings, coupled with magmatic activity driven by the greater-than-average heat flux in the region.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Andrews-Hanna, Jeffrey C -- Besserer, Jonathan -- Head, James W 3rd -- Howett, Carly J A -- Kiefer, Walter S -- Lucey, Paul J -- McGovern, Patrick J -- Melosh, H Jay -- Neumann, Gregory A -- Phillips, Roger J -- Schenk, Paul M -- Smith, David E -- Solomon, Sean C -- Zuber, Maria T -- England -- Nature. 2014 Oct 2;514(7520):68-71. doi: 10.1038/nature13697.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Geophysics and Center for Space Resources, Colorado School of Mines, Golden, Colorado 80401, USA. ; Department of Earth and Planetary Sciences, University of California, Santa Cruz, California 95064, USA. ; Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island 02912, USA. ; Planetary Science Directorate, Southwest Research Institute, Boulder, Colorado 80302, USA. ; Lunar and Planetary Institute, Houston, Texas 77058, USA. ; Hawaii Institute of Geophysics and Planetology, University of Hawaii, Honolulu, Hawaii 96822, USA. ; Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, Indiana 47907, USA. ; Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA. ; Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA. ; 1] Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington DC 20015, USA [2] Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25279919" target="_blank"〉PubMed〈/a〉

Description: The earliest history of the Moon is poorly preserved in the surface geologic record due to the high flux of impactors, but aspects of that history may be preserved in subsurface structures. Application of gravity gradiometry to observations by the Gravity Recovery and Interior Laboratory (GRAIL) mission results in the identification of a population of linear gravity anomalies with lengths of hundreds of kilometers. Inversion of the gravity anomalies indicates elongated positive-density anomalies that are interpreted to be ancient vertical tabular intrusions or dikes formed by magmatism in combination with extension of the lithosphere. Crosscutting relationships support a pre-Nectarian to Nectarian age, preceding the end of the heavy bombardment of the Moon. The distribution, orientation, and dimensions of the intrusions indicate a globally isotropic extensional stress state arising from an increase in the Moon's radius by 0.6 to 4.9 kilometers early in lunar history, consistent with predictions of thermal models.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Andrews-Hanna, Jeffrey C -- Asmar, Sami W -- Head, James W 3rd -- Kiefer, Walter S -- Konopliv, Alexander S -- Lemoine, Frank G -- Matsuyama, Isamu -- Mazarico, Erwan -- McGovern, Patrick J -- Melosh, H Jay -- Neumann, Gregory A -- Nimmo, Francis -- Phillips, Roger J -- Smith, David E -- Solomon, Sean C -- Taylor, G Jeffrey -- Wieczorek, Mark A -- Williams, James G -- Zuber, Maria T -- New York, N.Y. -- Science. 2013 Feb 8;339(6120):675-8. doi: 10.1126/science.1231753. Epub 2012 Dec 5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Geophysics and Center for Space Resources, Colorado School of Mines, Golden, CO 80401, USA. jcahanna@mines.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23223393" target="_blank"〉PubMed〈/a〉

Description: High-resolution gravity data from the Gravity Recovery and Interior Laboratory spacecraft have clarified the origin of lunar mass concentrations (mascons). Free-air gravity anomalies over lunar impact basins display bull's-eye patterns consisting of a central positive (mascon) anomaly, a surrounding negative collar, and a positive outer annulus. We show that this pattern results from impact basin excavation and collapse followed by isostatic adjustment and cooling and contraction of a voluminous melt pool. We used a hydrocode to simulate the impact and a self-consistent finite-element model to simulate the subsequent viscoelastic relaxation and cooling. The primary parameters controlling the modeled gravity signatures of mascon basins are the impactor energy, the lunar thermal gradient at the time of impact, the crustal thickness, and the extent of volcanic fill.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Melosh, H J -- Freed, Andrew M -- Johnson, Brandon C -- Blair, David M -- Andrews-Hanna, Jeffrey C -- Neumann, Gregory A -- Phillips, Roger J -- Smith, David E -- Solomon, Sean C -- Wieczorek, Mark A -- Zuber, Maria T -- New York, N.Y. -- Science. 2013 Jun 28;340(6140):1552-5. doi: 10.1126/science.1235768. Epub 2013 May 30.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907, USA. jmelosh@purdue.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23722426" target="_blank"〉PubMed〈/a〉