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Sample records for 1-2 billion years

  1. Atmospheric oxygenation three billion years ago.

    PubMed

    Crowe, Sean A; Døssing, Lasse N; Beukes, Nicolas J; Bau, Michael; Kruger, Stephanus J; Frei, Robert; Canfield, Donald E

    2013-09-26

    It is widely assumed that atmospheric oxygen concentrations remained persistently low (less than 10(-5) times present levels) for about the first 2 billion years of Earth's history. The first long-term oxygenation of the atmosphere is thought to have taken place around 2.3 billion years ago, during the Great Oxidation Event. Geochemical indications of transient atmospheric oxygenation, however, date back to 2.6-2.7 billion years ago. Here we examine the distribution of chromium isotopes and redox-sensitive metals in the approximately 3-billion-year-old Nsuze palaeosol and in the near-contemporaneous Ijzermyn iron formation from the Pongola Supergroup, South Africa. We find extensive mobilization of redox-sensitive elements through oxidative weathering. Furthermore, using our data we compute a best minimum estimate for atmospheric oxygen concentrations at that time of 3 × 10(-4) times present levels. Overall, our findings suggest that there were appreciable levels of atmospheric oxygen about 3 billion years ago, more than 600 million years before the Great Oxidation Event and some 300-400 million years earlier than previous indications for Earth surface oxygenation.

  2. Life: the first two billion years.

    PubMed

    Knoll, Andrew H; Bergmann, Kristin D; Strauss, Justin V

    2016-11-05

    Microfossils, stromatolites, preserved lipids and biologically informative isotopic ratios provide a substantial record of bacterial diversity and biogeochemical cycles in Proterozoic (2500-541 Ma) oceans that can be interpreted, at least broadly, in terms of present-day organisms and metabolic processes. Archean (more than 2500 Ma) sedimentary rocks add at least a billion years to the recorded history of life, with sedimentological and biogeochemical evidence for life at 3500 Ma, and possibly earlier; phylogenetic and functional details, however, are limited. Geochemistry provides a major constraint on early evolution, indicating that the first bacteria were shaped by anoxic environments, with distinct patterns of major and micronutrient availability. Archean rocks appear to record the Earth's first iron age, with reduced Fe as the principal electron donor for photosynthesis, oxidized Fe the most abundant terminal electron acceptor for respiration, and Fe a key cofactor in proteins. With the permanent oxygenation of the atmosphere and surface ocean ca 2400 Ma, photic zone O2 limited the access of photosynthetic bacteria to electron donors other than water, while expanding the inventory of oxidants available for respiration and chemoautotrophy. Thus, halfway through Earth history, the microbial underpinnings of modern marine ecosystems began to take shape.This article is part of the themed issue 'The new bacteriology'.

  3. Energy tax price tag for CPI: $1. 2 billion, jobs, and production

    SciTech Connect

    Begley, R.

    1993-03-03

    If President Clinton's proposed energy tax had been fully in place last year, it would have cost the US chemical industry an additional $1.2 billion and 9,900 jobs, according to Chemical Manufacturers Association (CMA; Washington) estimates. It also would have driven output down 3% and prices up 5%, CMA says. Allen Lenz, CMA director/trade and economics, says the increase in production costs that would accompany the tax will not be shared by foreign competitors, cannot be neutralized with higher border taxes because of existing trade agreements, and provides another reason to move production offshore. Worse, the US chemical industry's generally impressive trade surplus declined by $2.5 billion last year, and a further drop is projected for this year. The margin of error gets thinner all the time as competition increases, Lenz says. We're not concerned only with the chemical industry, but the rest of US-based manufacturing because they taken half our output, he adds. One problem is the energy intensiveness of the chemical process industries-a CMA report says that 55% of the cost of producing ethylene glycol is energy related. And double taxation of such things as coproducts returned for credit to oil refineries could add up to $115 million/year, the report says.

  4. Large data analysis: automatic visual personal identification in a demography of 1.2 billion persons

    NASA Astrophysics Data System (ADS)

    Daugman, John

    2014-05-01

    The largest biometric deployment in history is now underway in India, where the Government is enrolling the iris patterns (among other data) of all 1.2 billion citizens. The purpose of the Unique Identification Authority of India (UIDAI) is to ensure fair access to welfare benefits and entitlements, to reduce fraud, and enhance social inclusion. Only a minority of Indian citizens have bank accounts; only 4 percent possess passports; and less than half of all aid money reaches its intended recipients. A person who lacks any means of establishing their identity is excluded from entitlements and does not officially exist; thus the slogan of UIDAI is: To give the poor an identity." This ambitious program enrolls a million people every day, across 36,000 stations run by 83 agencies, with a 3-year completion target for the entire national population. The halfway point was recently passed with more than 600 million persons now enrolled. In order to detect and prevent duplicate identities, every iris pattern that is enrolled is first compared against all others enrolled so far; thus the daily workflow now requires 600 trillion (or 600 million-million) iris cross-comparisons. Avoiding identity collisions (False Matches) requires high biometric entropy, and achieving the tremendous match speed requires phase bit coding. Both of these requirements are being delivered operationally by wavelet methods developed by the author for encoding and comparing iris patterns, which will be the focus of this Large Data Award" presentation.

  5. Conservation of protein structure over four billion years

    PubMed Central

    Ingles-Prieto, Alvaro; Ibarra-Molero, Beatriz; Delgado-Delgado, Asuncion; Perez-Jimenez, Raul; Fernandez, Julio M.; Gaucher, Eric A.; Sanchez-Ruiz, Jose M.; Gavira, Jose A.

    2013-01-01

    SUMMARY Little is known with certainty about the evolution of protein structures in general and the degree of protein structure conservation over planetary time scales in particular. Here we report the X-ray crystal structures of seven laboratory resurrections of Precambrian thioredoxins dating back up to ~4 billion years before present. Despite considerable sequence differences compared with extant enzymes, the ancestral proteins display the canonical thioredoxin fold while only small structural changes have occurred over 4 billion years. This remarkable degree of structure conservation since a time near the last common ancestor of life supports a punctuated-equilibrium model of structure evolution in which the generation of new folds occurs over comparatively short periods of time and is followed by long periods of structural stasis. PMID:23932589

  6. Conservation of protein structure over four billion years.

    PubMed

    Ingles-Prieto, Alvaro; Ibarra-Molero, Beatriz; Delgado-Delgado, Asuncion; Perez-Jimenez, Raul; Fernandez, Julio M; Gaucher, Eric A; Sanchez-Ruiz, Jose M; Gavira, Jose A

    2013-09-03

    Little is known about the evolution of protein structures and the degree of protein structure conservation over planetary time scales. Here, we report the X-ray crystal structures of seven laboratory resurrections of Precambrian thioredoxins dating up to approximately four billion years ago. Despite considerable sequence differences compared with extant enzymes, the ancestral proteins display the canonical thioredoxin fold, whereas only small structural changes have occurred over four billion years. This remarkable degree of structure conservation since a time near the last common ancestor of life supports a punctuated-equilibrium model of structure evolution in which the generation of new folds occurs over comparatively short periods and is followed by long periods of structural stasis.

  7. Emergence of modern continental crust about 3 billion years ago

    NASA Astrophysics Data System (ADS)

    Dhuime, Bruno; Wuestefeld, Andreas; Hawkesworth, Chris J.

    2015-07-01

    The continental crust is the principal record of conditions on the Earth during the past 4.4 billion years. However, how the continental crust formed and evolved through time remains highly controversial. In particular, the composition and thickness of juvenile continental crust are unknown. Here we show that Rb/Sr ratios can be used as a proxy for both the silica content and the thickness of the continental crust. We calculate Rb/Sr ratios of the juvenile crust for over 13,000 samples, with Nd model ages ranging from the Hadean to Phanerozoic. The ratios were calculated based on the evolution of Sr isotopes in the period between the TDM Nd model age and the crystallization of the samples analysed. We find that the juvenile crust had a low silica content and was largely mafic in composition during the first 1.5 billion years of Earth’s evolution, consistent with magmatism on a pre-plate tectonics planet. About 3 billion years ago, the Rb/Sr ratios of the juvenile continental crust increased, indicating that the newly formed crust became more silica-rich and probably thicker. This transition is in turn linked to the onset of plate tectonics and an increase of continental detritus into the oceans.

  8. Providing safe drinking water to 1.2 billion unserved people

    SciTech Connect

    Gadgil, Ashok J.; Derby, Elisabeth A.

    2003-06-01

    Despite substantial advances in the past 100 years in public health, technology and medicine, 20% of the world population, mostly comprised of the poor population segments in developing countries (DCs), still does not have access to safe drinking water. To reach the United Nations (UN) Millennium Goal of halving the number of people without access to safe water by 2015, the global community will need to provide an additional one billion urban residents and 600 million rural residents with safe water within the next twelve years. This paper examines current water treatment measures and implementation methods for delivery of safe drinking water, and offers suggestions for making progress towards the goal of providing a timely and equitable solution for safe water provision. For water treatment, based on the serious limitations of boiling water and chlorination, we suggest an approach based on filtration coupled with ultraviolet (UV) disinfection, combined with public education. Additionally, owing to the capacity limitations for non-governmental organizations (NGOs) to take on this task primarily on their own, we suggest a strategy based on financially sustainable models that include the private sector as well as NGOs.

  9. Orbital forcing of climate 1.4 billion years ago.

    PubMed

    Zhang, Shuichang; Wang, Xiaomei; Hammarlund, Emma U; Wang, Huajian; Costa, M Mafalda; Bjerrum, Christian J; Connelly, James N; Zhang, Baomin; Bian, Lizeng; Canfield, Donald E

    2015-03-24

    Fluctuating climate is a hallmark of Earth. As one transcends deep into Earth time, however, both the evidence for and the causes of climate change become difficult to establish. We report geochemical and sedimentological evidence for repeated, short-term climate fluctuations from the exceptionally well-preserved ∼1.4-billion-year-old Xiamaling Formation of the North China Craton. We observe two patterns of climate fluctuations: On long time scales, over what amounts to tens of millions of years, sediments of the Xiamaling Formation record changes in geochemistry consistent with long-term changes in the location of the Xiamaling relative to the position of the Intertropical Convergence Zone. On shorter time scales, and within a precisely calibrated stratigraphic framework, cyclicity in sediment geochemical dynamics is consistent with orbital control. In particular, sediment geochemical fluctuations reflect what appear to be orbitally forced changes in wind patterns and ocean circulation as they influenced rates of organic carbon flux, trace metal accumulation, and the source of detrital particles to the sediment.

  10. Orbital forcing of climate 1.4 billion years ago

    PubMed Central

    Zhang, Shuichang; Wang, Xiaomei; Hammarlund, Emma U.; Wang, Huajian; Costa, M. Mafalda; Bjerrum, Christian J.; Connelly, James N.; Zhang, Baomin; Bian, Lizeng; Canfield, Donald E.

    2015-01-01

    Fluctuating climate is a hallmark of Earth. As one transcends deep into Earth time, however, both the evidence for and the causes of climate change become difficult to establish. We report geochemical and sedimentological evidence for repeated, short-term climate fluctuations from the exceptionally well-preserved ∼1.4-billion-year-old Xiamaling Formation of the North China Craton. We observe two patterns of climate fluctuations: On long time scales, over what amounts to tens of millions of years, sediments of the Xiamaling Formation record changes in geochemistry consistent with long-term changes in the location of the Xiamaling relative to the position of the Intertropical Convergence Zone. On shorter time scales, and within a precisely calibrated stratigraphic framework, cyclicity in sediment geochemical dynamics is consistent with orbital control. In particular, sediment geochemical fluctuations reflect what appear to be orbitally forced changes in wind patterns and ocean circulation as they influenced rates of organic carbon flux, trace metal accumulation, and the source of detrital particles to the sediment. PMID:25775605

  11. Nine Billion Years: Past and Future of the Solar System

    NASA Astrophysics Data System (ADS)

    Leubner, I. H.

    2013-05-01

    As the Sun is losing mass and thus gravity by radiation and solar wind, solar-planetary energy balances diminish. Since the planets are only weakly bound to the Sun, the planets have been moving away from the Sun, causing increases of orbits and orbital periods. This is modeled for selected planets from Mercury to Sedna and from the formation of the Solar system at -4.5 to +4.5 billion years (Byr/Ma). Planets were initially significantly closer to the Sun, suggesting that modeling of the formation of the solar system needs to be revisited. By +4.5Byr planets beyond Saturn will have separated from the Solar System. The presently outermost solar object, Sedna, is in the process of separation. Climate changes of Mars and Earth are modeled as a function of time. The prediction of the transition of Mars from water to ice at -3.6 Byr is in agreement with observations (-2.9 to -3.7 Byr). This provides for the first time answers to the why and when of water to ice transition on Mars. Earth temperatures are predicted to decrease by of 38, 24, and 20C between -4.5 Byr to +4.5 Byr for present temperatures of +50, 0, and -50 C, respectively. Mars: Water - Ice Transition

  12. 3.5 billion years of reshaped Moho, southern Africa

    NASA Astrophysics Data System (ADS)

    Stankiewicz, Jacek; de Wit, Maarten

    2013-12-01

    According to some previous studies, Archean continental crust is, on global average, apparently thinner than Proterozoic crust. Subsequently, the validity of this statement has been questioned. To provide an additional perspective on this issue, we present analyses of Moho signatures derived from recent seismic data along swaths 2000 km in length across southern Africa and its flanking ocean. The imaged crust has a near continuous age range between ca. 0.1 and 3.7 billion years, and the seismic data allow direct comparison of Moho depths between adjacent Archean, Proterozoic and Phanerozoic crust. We find no simple secular change in depth to Moho over this time period. In contrast, there is significant variation in depth to Moho beneath both Archean and Proterozoic crust; Archean crust of southern Africa displays as much crustal diversity in thickness as the adjacent Proterozoic crust. The Moho beneath all crustal provinces that we have analysed has been severely altered by tectono-metamorphic and igneous processes, in many cases more than once, and cannot provide unequivocal data for geodynamic models dealing with secular changes in continental crust formation. These results and conclusions are similar to those documented along ca. 2000 km swaths across the Canadian Shield recorded by Lithoprobe. Tying the age and character of the Precambrian crust of southern Africa to their depth diversities is clearly related to manifold processes of tectono-thermal ‘surgery’ subsequent to their origin, the details of which are still to be resolved, as they are in most Precambrian terranes. Reconstructing pristine Moho of the early Earth therefore remains a formidable challenge. In South Africa, better knowledge of ‘fossilised’ Archean crustal sections ‘turned-on-edge’, such as at the Vredefort impact crater (for the continental crust), and from the Barberton greenstone belt (for oceanic crust) is needed to characterize potential pristine Archean Moho transitions.

  13. Missing billions.

    PubMed

    Conly, S

    1997-01-01

    This article discusses funding of population programs that support the Cairo International Conference on Population and Development's Plan of Action. The Plan of Action calls for a quadrupling of annual financial commitments for population programs to $17 billion by the year 2000 and $22 billion by 2015. The increased expenditures would cover the increased demand for services from unmet need and population growth. Donor countries are expected to increase their share from the current 25% to about 33%, or $5.7 billion by the year 2000. The estimates are in 1993 constant dollars. $17 billion is less than the $40 billion that is spent worldwide on playing golf. During 1993-94, general donor support increased to $1.2 billion. Denmark, Germany, Japan, the Netherlands, the United Kingdom, and the United States increased their support. The United States doubled its support for population programs during 1992-95 to $583 million. During 1996-97 the US Congress cut funding back to the 1995 level. France, Italy, Spain, Belgium, and Austria have lagged in support for population programs in the present and the past. Equal burden sharing would require the US to increase funding to $1.9 billion. Developed country assistance declined to the lowest share of combined gross national product since 1970. This shifts the burden to multilateral sources. The European Union is committed to increasing its funding, and the World Bank increased funding for population and reproductive health to about $600 million in 1996 from $424 million in 1994. Bangladesh, China, India, Indonesia, Mexico, South Africa, and Turkey spent 85% of all government expenditures on family planning in developing countries. External donors in Africa are the main support of family planning. Private consumers in Latin America pay most of the costs of family planning. External assistance will be needed for some time.

  14. A SWIRE Picture is Worth Billions of Years

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1: SWIRE View of Distant Galaxies [figure removed for brevity, see original site] [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 2Figure 3 Figure 4

    These spectacular images, taken by the Spitzer Wide-area Infrared Extragalactic (SWIRE) Legacy project, encapsulate one of the primary objectives of the Spitzer mission: to connect the evolution of galaxies from the distant, or early, universe to the nearby, or present day, universe.

    The Tadpole galaxy (main image) is the result of a recent galactic interaction in the local universe. Although these galactic mergers are rare in the universe's recent history, astronomers believe that they were much more common in the early universe. Thus, SWIRE team members will use this detailed image of the Tadpole galaxy to help understand the nature of the 'faint red-orange specks' of the early universe.

    The larger picture (figure 2) depicts one-sixteenth of the SWIRE survey field called ELAIS-N1. In this image, the bright blue sources are hot stars in our own Milky Way, which range anywhere from 3 to 60 times the mass of our Sun. The fainter green spots are cooler stars and galaxies beyond the Milky Way whose light is dominated by older stellar populations. The red dots are dusty galaxies that are undergoing intense star formation. The faintest specks of red-orange are galaxies billions of light-years away in the distant universe.

    Figure 3 features an unusual ring-like galaxy called CGCG 275-022. The red spiral arms indicate that this galaxy is very dusty and perhaps undergoing intense star formation. The star-forming activity could have been initiated by a near head-on collision with another galaxy.

    The most distant galaxies that SWIRE is able to detect are revealed in a zoom of deep space (figure 4). The colors in this feature represent the same objects as those in the larger field image of ELAIS

  15. Galaxies in the First Billion Years After the Big Bang

    NASA Astrophysics Data System (ADS)

    Stark, Daniel P.

    2016-09-01

    In the past five years, deep imaging campaigns conducted with the Hubble Space Telescope (HST) and ground-based observatories have delivered large samples of galaxies at 6.56 UV-selected galaxies are relatively compact with blue UV continuum slopes, low stellar masses, and large specific star formation rates. In the last year, ALMA (the Atacama Large Millimeter Array) and ground-based infrared spectrographs have begun to complement this picture, revealing minimal dust obscuration and hard radiation fields, and providing evidence for metal-poor ionized gas. Weak low-ionization absorption lines suggest a patchy distribution of neutral gas surrounds O and B stars, possibly aiding in the escape of ionizing radiation. Gamma ray burst afterglows and Lyman-α surveys have provided evidence that the intergalactic medium (IGM) evolves from mostly ionized at z≃6-6.5 ([Formula: see text]) to considerably neutral at z≃7-8 ([Formula: see text]). The reionization history that emerges from considering the UV output of galaxies over 6

  16. Birth of the Kaapvaal tectosphere 3.08 billion years ago.

    PubMed

    Moser, D E; Flowers, R M; Hart, R J

    2001-01-19

    The crustal remnants of Earth's Archean continents have been shielded from mantle convection by thick roots of ancient mantle lithosphere. The precise time of crust-root coupling (tectosphere birth) is poorly known but is needed to test competing theories of continental plate genesis. Our mapping and geochronology of an impact-generated section through the Mesoarchean crust of the Kaapvaal craton indicates tectosphere birth at 3.08 +/- 0.01 billion years ago, roughly 0.12 billion years after crust assembly. Growth of the southern African mantle root by subduction processes occurred within about 0.2 billion years. The assembly of crust before mantle may be common to the tectosphere.

  17. Large molecular gas reservoirs in ancestors of Milky Way-mass galaxies nine billion years ago

    NASA Astrophysics Data System (ADS)

    Papovich, C.; Labbé, I.; Glazebrook, K.; Quadri, R.; Bekiaris, G.; Dickinson, M.; Finkelstein, S. L.; Fisher, D.; Inami, H.; Livermore, R. C.; Spitler, L.; Straatman, C.; Tran, K.-V.

    2016-12-01

    The gas accretion and star formation histories of galaxies like the Milky Way remain an outstanding problem in astrophysics 1,2 . Observations show that 8 billion years ago, the progenitors to Milky Way-mass galaxies were forming stars 30 times faster than today and were predicted to be rich in molecular gas 3 , in contrast to the low present-day gas fractions (<10%) 4-6 . Here we show the detection of molecular gas from the CO (J = 3-2) emission (rest-frame 345.8 GHz) in galaxies at redshifts z = 1.2-1.3, selected to have the stellar mass and star formation rate of the progenitors of today's Milky Way-mass galaxies. The CO emission reveals large molecular gas masses, comparable to or exceeding the galaxy stellar masses, and implying that most of the baryons are in cold gas, not stars. The total luminosities of the galaxies from star formation and CO luminosities yield long gas consumption timescales. Compared to local spiral galaxies, the star formation efficiency, estimated from the ratio of total infrared luminosity (L IR) to CO emission, has remained nearly constant since redshift z = 1.2, despite the order of magnitude decrease in gas fraction, consistent with the results for other galaxies at this epoch 7-10 . Therefore, the physical processes that determine the rate at which gas cools to form stars in distant galaxies appear to be similar to that in local galaxies.

  18. 3.4-Billion-year-old biogenic pyrites from Barberton, South Africa: sulfur isotope evidence.

    PubMed

    Ohmoto, H; Kakegawa, T; Lowe, D R

    1993-10-22

    Laser ablation mass spectroscopy analyses of sulfur isotopic compositions of microscopic-sized grains of pyrite that formed about 3.4 billion years ago in the Barberton Greenstone Belt, South Africa, show that the pyrite formed by bacterial reduction of seawater sulfate. These data imply that by about 3.4 billion years ago sulfate-reducing bacteria had become active, the oceans were rich in sulfate, and the atmosphere contained appreciable amounts (>10(-13) of the present atmospheric level) of free oxygen.

  19. 3.4-Billion-year-old biogenic pyrites from Barberton, South Africa: sulfur isotope evidence

    NASA Technical Reports Server (NTRS)

    Ohmoto, H.; Kakegawa, T.; Lowe, D. R.

    1993-01-01

    Laser ablation mass spectroscopy analyses of sulfur isotopic compositions of microscopic-sized grains of pyrite that formed about 3.4 billion years ago in the Barberton Greenstone Belt, South Africa, show that the pyrite formed by bacterial reduction of seawater sulfate. These data imply that by about 3.4 billion years ago sulfate-reducing bacteria had become active, the oceans were rich in sulfate, and the atmosphere contained appreciable amounts (>>10(-13) of the present atmospheric level) of free oxygen.

  20. Two billion years of magmatism recorded from a single Mars meteorite ejection site.

    PubMed

    Lapen, Thomas J; Righter, Minako; Andreasen, Rasmus; Irving, Anthony J; Satkoski, Aaron M; Beard, Brian L; Nishiizumi, Kunihiko; Jull, A J Timothy; Caffee, Marc W

    2017-02-01

    The timing and nature of igneous activity recorded at a single Mars ejection site can be determined from the isotope analyses of Martian meteorites. Northwest Africa (NWA) 7635 has an Sm-Nd crystallization age of 2.403 ± 0.140 billion years, and isotope data indicate that it is derived from an incompatible trace element-depleted mantle source similar to that which produced a geochemically distinct group of 327- to 574-million-year-old "depleted" shergottites. Cosmogenic nuclide data demonstrate that NWA 7635 was ejected from Mars 1.1 million years ago (Ma), as were at least 10 other depleted shergottites. The shared ejection age is consistent with a common ejection site for these meteorites. The spatial association of 327- to 2403-Ma depleted shergottites indicates >2 billion years of magmatism from a long-lived and geochemically distinct volcanic center near the ejection site.

  1. Two billion years of magmatism recorded from a single Mars meteorite ejection site

    PubMed Central

    Lapen, Thomas J.; Righter, Minako; Andreasen, Rasmus; Irving, Anthony J.; Satkoski, Aaron M.; Beard, Brian L.; Nishiizumi, Kunihiko; Jull, A. J. Timothy; Caffee, Marc W.

    2017-01-01

    The timing and nature of igneous activity recorded at a single Mars ejection site can be determined from the isotope analyses of Martian meteorites. Northwest Africa (NWA) 7635 has an Sm-Nd crystallization age of 2.403 ± 0.140 billion years, and isotope data indicate that it is derived from an incompatible trace element–depleted mantle source similar to that which produced a geochemically distinct group of 327- to 574-million-year-old “depleted” shergottites. Cosmogenic nuclide data demonstrate that NWA 7635 was ejected from Mars 1.1 million years ago (Ma), as were at least 10 other depleted shergottites. The shared ejection age is consistent with a common ejection site for these meteorites. The spatial association of 327- to 2403-Ma depleted shergottites indicates >2 billion years of magmatism from a long-lived and geochemically distinct volcanic center near the ejection site. PMID:28164153

  2. Exploring for Galaxies in the First Billion Years with Hubble and Spitzer - Pathfinding for JWST

    NASA Astrophysics Data System (ADS)

    Illingworth, Garth D.

    2017-01-01

    Hubble has revolutionized the field of distant galaxies through its deep imaging surveys, starting with the Hubble Deep Field (HDF) in 1995. That first deep survey revealed galaxies at redshift z~1-3 that provided insights into the development of the Hubble sequence. Each new HST instrument has explored new regimes, through the peak of star formation at z~2-3, just 2-3 billion years after the Big Bang, to our first datasets at a billion years at z~6, and then earlier to z~11. HST's survey capabilities were enhanced by 40X with ACS, and then similarly with the WFC3/IR, which opened up the first billion years to an unforeseen degree. I will discuss what we have learned from the remarkable HST and Spitzer imaging surveys (HUDF, GOODS, HUDF09/12 and CANDELS), as well as surveys of clusters like the Hubble Frontier Fields (HFF). Lensing clusters provide extraordinary opportunities for characterizing the faintest earliest galaxies, but also present extraordinary challenges. Together these surveys have resulted in the measurement of the volume density of galaxies in the first billion years down to astonishingly faint levels. The role of faint galaxies in reionizing the universe is still much-discussed, but there is no doubt that such galaxies contribute greatly to the UV ionizing flux, as shown by deep luminosity function studies. Together Hubble and Spitzer have also established the stellar-mass buildup over 97% of cosmic history. Yet some of the greatest surprises have come from the discovery of very luminous galaxies at z~8-11, around 400-650 million years after the Big Bang. Spectroscopic followup by Keck of some of these very rare, bright galaxies has confirmed redshifts from z~7 to z~9, and revealed, surprisingly, strong Lyα emission near the peak of reionization when the HI fraction in the IGM is high. The recent confirmation of a z=11.1 galaxy, just 400 million years after the Big Bang, by a combination of Hubble and Spitzer data, moved Hubble into JWST territory

  3. The First Billion Years: The Growth of Galaxies in the Reionization Epoch

    NASA Astrophysics Data System (ADS)

    Illingworth, Garth

    2015-08-01

    Detection and measurement of the earliest galaxies in the first billion years only became possible after the Hubble Space Telescope was updated in 2009 with the infrared WFC3/IR camera during Shuttle servicing mission SM4. The first billion years is a fascinating epoch, not just because of the earliest galaxies known from about 450 Myr after the Big Bang, but also because it encompasses the reionization epoch that peaked around z~9, as Planck has recently shown, and ended around redshift z~6 at 900 Myr. Before 2009 just a handful of galaxies were known in the reionization epoch at z>6. But within the last 5 years, with the first HUDF09 survey, the HUDF12, CANDELS and numerous other surveys on the GOODS and CANDELS fields, as well as detections from the cluster lensing programs like CLASH and the Frontier Fields, the number of galaxies at redshifts 7-10 has exploded, with some 700 galaxies being found and characterized. The first billion years was a period of extraordinary growth in the galaxy population with rapid growth in the star formation rate density and global mass density in galaxies. Spitzer observations in the infrared of these Hubble fields are establishing masses as well as giving insights into the nature and timescales of star formation from the very powerful emission lines being revealed by the Spitzer IRAC data. I will discuss what we understand about the growth of galaxies in this epoch from the insights gained from remarkable deep fields like the XDF, as well as the wide-area GOODS/CANDELS fields, the detection of unexpectedly luminous galaxies at redshifts 8-10, the impact of early galaxies on reionization, confirmation of a number of galaxies at z~7-8 from ground-based spectroscopic measurements, and the indications of a change in the growth of the star formation rate around 500 Myr. The first billion years was a time of dramatic growth and change in the early galaxy population.

  4. Increased subaerial volcanism and the rise of atmospheric oxygen 2.5 billion years ago.

    PubMed

    Kump, Lee R; Barley, Mark E

    2007-08-30

    The hypothesis that the establishment of a permanently oxygenated atmosphere at the Archaean-Proterozoic transition (approximately 2.5 billion years ago) occurred when oxygen-producing cyanobacteria evolved is contradicted by biomarker evidence for their presence in rocks 200 million years older. To sustain vanishingly low oxygen levels despite near-modern rates of oxygen production from approximately 2.7-2.5 billion years ago thus requires that oxygen sinks must have been much larger than they are now. Here we propose that the rise of atmospheric oxygen occurred because the predominant sink for oxygen in the Archaean era-enhanced submarine volcanism-was abruptly and permanently diminished during the Archaean-Proterozoic transition. Observations are consistent with the corollary that subaerial volcanism only became widespread after a major tectonic episode of continental stabilization at the beginning of the Proterozoic. Submarine volcanoes are more reducing than subaerial volcanoes, so a shift from predominantly submarine to a mix of subaerial and submarine volcanism more similar to that observed today would have reduced the overall sink for oxygen and led to the rise of atmospheric oxygen.

  5. A massive galaxy in its core formation phase three billion years after the Big Bang.

    PubMed

    Nelson, Erica; van Dokkum, Pieter; Franx, Marijn; Brammer, Gabriel; Momcheva, Ivelina; Schreiber, Natascha Förster; da Cunha, Elisabete; Tacconi, Linda; Bezanson, Rachel; Kirkpatrick, Allison; Leja, Joel; Rix, Hans-Walter; Skelton, Rosalind; van der Wel, Arjen; Whitaker, Katherine; Wuyts, Stijn

    2014-09-18

    Most massive galaxies are thought to have formed their dense stellar cores in early cosmic epochs. Previous studies have found galaxies with high gas velocity dispersions or small apparent sizes, but so far no objects have been identified with both the stellar structure and the gas dynamics of a forming core. Here we report a candidate core in the process of formation 11 billion years ago, at redshift z = 2.3. This galaxy, GOODS-N-774, has a stellar mass of 100 billion solar masses, a half-light radius of 1.0 kiloparsecs and a star formation rate of solar masses per year. The star-forming gas has a velocity dispersion of 317 ± 30 kilometres per second. This is similar to the stellar velocity dispersions of the putative descendants of GOODS-N-774, which are compact quiescent galaxies at z ≈ 2 (refs 8-11) and giant elliptical galaxies in the nearby Universe. Galaxies such as GOODS-N-774 seem to be rare; however, from the star formation rate and size of this galaxy we infer that many star-forming cores may be heavily obscured, and could be missed in optical and near-infrared surveys.

  6. The evolution in the stellar mass of brightest cluster galaxies over the past 10 billion years

    NASA Astrophysics Data System (ADS)

    Bellstedt, Sabine; Lidman, Chris; Muzzin, Adam; Franx, Marijn; Guatelli, Susanna; Hill, Allison R.; Hoekstra, Henk; Kurinsky, Noah; Labbe, Ivo; Marchesini, Danilo; Marsan, Z. Cemile; Safavi-Naeini, Mitra; Sifón, Cristóbal; Stefanon, Mauro; van de Sande, Jesse; van Dokkum, Pieter; Weigel, Catherine

    2016-08-01

    Using a sample of 98 galaxy clusters recently imaged in the near-infrared with the European Southern Observatory (ESO) New Technology Telescope, WIYN telescope and William Herschel Telescope, supplemented with 33 clusters from the ESO archive, we measure how the stellar mass of the most massive galaxies in the universe, namely brightest cluster galaxies (BCGs), increases with time. Most of the BCGs in this new sample lie in the redshift range 0.2 < z < 0.6, which has been noted in recent works to mark an epoch over which the growth in the stellar mass of BCGs stalls. From this sample of 132 clusters, we create a subsample of 102 systems that includes only those clusters that have estimates of the cluster mass. We combine the BCGs in this subsample with BCGs from the literature, and find that the growth in stellar mass of BCGs from 10 billion years ago to the present epoch is broadly consistent with recent semi-analytic and semi-empirical models. As in other recent studies, tentative evidence indicates that the stellar mass growth rate of BCGs may be slowing in the past 3.5 billion years. Further work in collecting larger samples, and in better comparing observations with theory using mock images, is required if a more detailed comparison between the models and the data is to be made.

  7. Early formation of the Moon 4.51 billion years ago

    PubMed Central

    Barboni, Melanie; Boehnke, Patrick; Keller, Brenhin; Kohl, Issaku E.; Schoene, Blair; Young, Edward D.; McKeegan, Kevin D.

    2017-01-01

    Establishing the age of the Moon is critical to understanding solar system evolution and the formation of rocky planets, including Earth. However, despite its importance, the age of the Moon has never been accurately determined. We present uranium-lead dating of Apollo 14 zircon fragments that yield highly precise, concordant ages, demonstrating that they are robust against postcrystallization isotopic disturbances. Hafnium isotopic analyses of the same fragments show extremely low initial 176Hf/177Hf ratios corrected for cosmic ray exposure that are near the solar system initial value. Our data indicate differentiation of the lunar crust by 4.51 billion years, indicating the formation of the Moon within the first ~60 million years after the birth of the solar system. PMID:28097222

  8. Evidence for Early Life in ˜3.5 Billion-Year-Old Pillow Lavas

    NASA Astrophysics Data System (ADS)

    Banerjee, N. R.; Furnes, H.; Muehlenbachs, K.; Staudigel, H.; de Wit, M.

    2004-12-01

    Recently discovered biosignatures in the formerly glassy rims of ˜3.5 billion-year-old pillow lavas from the Barberton Greenstone Belt (BGB) in South Africa suggest they were colonized by microbes early in Earth's history. These subaqueous volcanic rocks represent a new geological setting in the search for early life on Earth. This is not entirely surprising since microbial alteration of basaltic glass in pillow lavas and volcaniclastic rocks has been well documented from recent oceanic crust and well-preserved ophiolites. The BGB magmatic sequence contains exceptionally well-preserved mafic to ultramafic pillow lavas, sheet flows, and intrusions interpreted to represent 3.48 to 3.22 billion-year-old oceanic crust and island arc assemblages. We observed micron-sized tubular structures mineralized by titanite in the formerly glassy rims of the BGB pillow lavas. Based on their similarity to textures observed in recent glassy pillow basalts we interpret these structures to represent ancient traces of microbial activity formed during biogenic etching of the originally glassy pillow rims as microbes colonized the glass surface. Petrographic observations coupled with overlapping metamorphic and magmatic dates indicate this process occurred soon after eruption of the pillow lavas. Subsequent greenschist facies seafloor hydrothermal alteration caused the structures to be mineralized by titanite; a process also observed in ophiolitic pillow lavas of much younger age. X-ray mapping reveals the presence of carbon along the margins of the tubular structures interpreted as residual organic material. Disseminated carbonates within the microbially-altered BGB pillow rims have low carbon isotope values consistent with microbial oxidation of organic matter. In contrast, disseminated carbonate in the crystalline pillow interiors have carbon isotope values bracketed between Archean marine carbonate and mantle carbon dioxide. It remains to be seen how deep into the Archean oceanic

  9. The VIRMOS-VLT Deep Survey: the Last 10 Billion Years of Evolution of Galaxy Clustering

    NASA Astrophysics Data System (ADS)

    Pollo, A.; Guzzo, L.; Le Fèvre, O.; Meneux, B.; Cappi, A.; McCracken, H. J.; Iovino, A.; Marinoni, C.; Bottini, D.; Garilli, B.; Le Brun, V. L.; Maccagni, D.; Picat, J. P.; Scaramella, R.; Scodeggio, M.; Tresse, L.; Vettolani, G.; Zanichelli, A.; Adami, C.; Arnouts, S.; Bardelli, S.; Bolzonella, M.; Charlot, S.; Ciliegi, P.; Contini, T.; Foucaud, S.; Franzetti, P.; Gavignaud, I.; Ilbert, O.; Marano, B.; Mazure, A.; Merighi, R.; Paltani, S.; Pellò, R.; Pozzetti, L.; Radovich, M.; Zamorani, G.; Zucca, E.; Bondi, M.; Bongiorno, A.; Brinchmann, J.; Cucciati, O.; de la Torre, S.; Lamareille, F.; Mellier, Y.; Merluzzi, P.; Temporin, S.; Vergani, D.; Walcher, C. J.

    2007-12-01

    We discuss the evolution of clustering of galaxies in the Universe from the present epoch back to z ˜ 2, using the first-epoch data from the VIMOS-VLT Deep Survey (VVDS). We present the evolution of the projected two-point correlation function of galaxies for the global galaxy population, as well as its dependence on galaxy intrinsic luminosities and spectral types. While we do not find strong variations of the correlation function parameters with redshift for the global galaxy population, the clustering of objects with different intrinsic luminosities evolved significantly during last 8-10 billion years. Our findings indicate that bright galaxies in the past traced higher density peaks than they do now and that the shape of the correlation function of most luminous galaxies is different from observed for their local counterparts, which is a supporting evidence of a non-trivial evolution of the galaxy vs. dark matter bias.

  10. Geodynamo, solar wind, and magnetopause 3.4 to 3.45 billion years ago.

    PubMed

    Tarduno, John A; Cottrell, Rory D; Watkeys, Michael K; Hofmann, Axel; Doubrovine, Pavel V; Mamajek, Eric E; Liu, Dunji; Sibeck, David G; Neukirch, Levi P; Usui, Yoichi

    2010-03-05

    Stellar wind standoff by a planetary magnetic field prevents atmospheric erosion and water loss. Although the early Earth retained its water and atmosphere, and thus evolved as a habitable planet, little is known about Earth's magnetic field strength during that time. We report paleointensity results from single silicate crystals bearing magnetic inclusions that record a geodynamo 3.4 to 3.45 billion years ago. The measured field strength is approximately 50 to 70% that of the present-day field. When combined with a greater Paleoarchean solar wind pressure, the paleofield strength data suggest steady-state magnetopause standoff distances of < or = 5 Earth radii, similar to values observed during recent coronal mass ejection events. The data also suggest lower-latitude aurora and increases in polar cap area, as well as heating, expansion, and volatile loss from the exosphere that would have affected long-term atmospheric composition.

  11. Extraterrestrial demise of banded iron formations 1.85 billion years ago

    USGS Publications Warehouse

    Slack, J.F.; Cannon, W.F.

    2009-01-01

    In the Lake Superior region of North America, deposition of most banded iron formations (BIFs) ended abruptly 1.85 Ga ago, coincident with the oceanic impact of the giant Sudbury extraterrestrial bolide. We propose a new model in which this impact produced global mixing of shallow oxic and deep anoxic waters of the Paleoproterozoic ocean, creating a suboxic redox state for deep seawater. This suboxic state, characterized by only small concentrations of dissolved O2 (???1 ??M), prevented transport of hydrothermally derived Fe(II) from the deep ocean to continental-margin settings, ending an ???1.1 billion-year-long period of episodic BIF mineralization. The model is supported by the nature of Precambrian deep-water exhalative chemical sediments, which changed from predominantly sulfide facies prior to ca. 1.85 Ga to mainly oxide facies thereafter. ?? 2009 Geological Society of America.

  12. Star Formation in Galaxy Clusters Over the Past 10 Billion Years

    NASA Astrophysics Data System (ADS)

    Tran, Kim-Vy

    2012-01-01

    Galaxy clusters are the largest gravitationally bound systems in the universe and include the most massive galaxies in the universe; this makes galaxy clusters ideal laboratories for disentangling the nature versus nurture aspect of how galaxies evolve. Understanding how galaxies form and evolve in clusters continues to be a fundamental question in astronomy. The ages and assembly histories of galaxies in rich clusters test both stellar population models and hierarchical formation scenarios. Is star formation in cluster galaxies simply accelerated relative to their counterparts in the lower density field, or do cluster galaxies assemble their stars in a fundamentally different manner? To answer this question, I review multi-wavelength results on star formation in galaxy clusters from Coma to the most distant clusters yet discovered at look-back times of 10 billion years (z 2).

  13. Atmospheric carbon dioxide: a driver of photosynthetic eukaryote evolution for over a billion years?

    PubMed

    Beerling, David J

    2012-02-19

    Exciting evidence from diverse fields, including physiology, evolutionary biology, palaeontology, geosciences and molecular genetics, is providing an increasingly secure basis for robustly formulating and evaluating hypotheses concerning the role of atmospheric carbon dioxide (CO(2)) in the evolution of photosynthetic eukaryotes. Such studies span over a billion years of evolutionary change, from the origins of eukaryotic algae through to the evolution of our present-day terrestrial floras, and have relevance for plant and ecosystem responses to future global CO(2) increases. The papers in this issue reflect the breadth and depth of approaches being adopted to address this issue. They reveal new discoveries pointing to deep evidence for the role of CO(2) in shaping evolutionary changes in plants and ecosystems, and establish an exciting cross-disciplinary research agenda for uncovering new insights into feedbacks between biology and the Earth system.

  14. Constraining the last 7 billion years of galaxy evolution in semi-analytic models

    NASA Astrophysics Data System (ADS)

    Mutch, Simon J.; Poole, Gregory B.; Croton, Darren J.

    2013-01-01

    We investigate the ability of the Croton et al. semi-analytic model to reproduce the evolution of observed galaxies across the final 7 billion years of cosmic history. Using Monte Carlo Markov Chain techniques we explore the available parameter space to produce a model which attempts to achieve a statistically accurate fit to the observed stellar mass function at z = 0 and z ≈ 0.8, as well as the local black hole-bulge relation. We find that in order to be successful we are required to push supernova feedback efficiencies to extreme limits which are, in some cases, unjustified by current observations. This leads us to the conclusion that the current model may be incomplete. Using the posterior probability distributions provided by our fitting, as well as the qualitative details of our produced stellar mass functions, we suggest that any future model improvements must act to preferentially bolster star formation efficiency in the most massive haloes at high redshift.

  15. Atmospheric carbon dioxide: a driver of photosynthetic eukaryote evolution for over a billion years?

    PubMed Central

    Beerling, David J.

    2012-01-01

    Exciting evidence from diverse fields, including physiology, evolutionary biology, palaeontology, geosciences and molecular genetics, is providing an increasingly secure basis for robustly formulating and evaluating hypotheses concerning the role of atmospheric carbon dioxide (CO2) in the evolution of photosynthetic eukaryotes. Such studies span over a billion years of evolutionary change, from the origins of eukaryotic algae through to the evolution of our present-day terrestrial floras, and have relevance for plant and ecosystem responses to future global CO2 increases. The papers in this issue reflect the breadth and depth of approaches being adopted to address this issue. They reveal new discoveries pointing to deep evidence for the role of CO2 in shaping evolutionary changes in plants and ecosystems, and establish an exciting cross-disciplinary research agenda for uncovering new insights into feedbacks between biology and the Earth system. PMID:22232760

  16. Dust production 0.7-1.5 billion years after the Big Bang

    NASA Astrophysics Data System (ADS)

    Michałowski, Michał J.

    2016-06-01

    Cosmic dust is an important component of the Universe, and its origin, especially at high redshifts, is still unknown. I present a simple but powerful method of assessing whether dust observed in a given galaxy could in principle have been formed by asymptotic giant branch (AGB) stars or supernovae (SNe). Using this method I show that for most of the galaxies with detected dust emission between z=4 and z=7.5 (1.5-0.7 billion years after the Big Bang) AGB stars are not numerous and efficient enough to be responsible for the measured dust masses. Supernovae could account for most of the dust, but only if all of them had efficiencies close to the maximal theoretically allowed value. This suggests that a different mechanism is responsible for dust production at high redshifts, and the most likely possibility is the grain growth in the interstellar medium.

  17. Searching for Organics Preserved in 4.5 Billion Year Old Salt

    NASA Technical Reports Server (NTRS)

    Zolensky, Michael E.; Fries, M.; Steele, A.; Bodnar, R.

    2012-01-01

    Our understanding of early solar system fluids took a dramatic turn a decade ago with the discovery of fluid inclusion-bearing halite (NaCl) crystals in the matrix of two freshly fallen brecciated H chondrite falls, Monahans and Zag. Both meteorites are regolith breccias, and contain xenolithic halite (and minor admixed sylvite -- KCl, crystals in their regolith lithologies. The halites are purple to dark blue, due to the presence of color centers (electrons in anion vacancies) which slowly accumulated as 40K (in sylvite) decayed over billions of years. The halites were dated by K-Ar, Rb-Sr and I-Xe systematics to be 4.5 billion years old. The "blue" halites were a fantastic discovery for the following reasons: (1) Halite+sylvite can be dated (K is in sylvite and will substitute for Na in halite, Rb substitutes in halite for Na, and I substitutes for Cl). (2) The blue color is lost if the halite dissolves on Earth and reprecipitates (because the newly-formed halite has no color centers), so the color serves as a "freshness" or pristinity indicator. (3) Halite frequently contains aqueous fluid inclusions. (4) Halite contains no structural oxygen, carbon or hydrogen, making them ideal materials to measure these isotopic systems in any fluid inclusions. (5) It is possible to directly measure fluid inclusion formation temperatures, and thus directly measure the temperature of the mineralizing aqueous fluid. In addition to these two ordinary chondrites halite grains have been reliably reported in several ureilites, an additional ordinary chondrite (Jilin), and in the carbonaceous chondrite (Murchison), although these reports were unfortunately not taken seriously. We have lately found additional fluid inclusions in carbonates in several additional carbonaceous chondrites. Meteoritic aqueous fluid inclusions are apparently relatively widespread in meteorites, though very small and thus difficult to analyze.

  18. Prodigious degassing of a billion years of accumulated radiogenic helium at Yellowstone

    NASA Astrophysics Data System (ADS)

    Lowenstern, J. B.; Evans, W. C.; Bergfeld, D.; Hunt, A. G.

    2014-02-01

    Helium is used as a critical tracer throughout the Earth sciences, where its relatively simple isotopic systematics is used to trace degassing from the mantle, to date groundwater and to time the rise of continents. The hydrothermal system at Yellowstone National Park is famous for its high helium-3/helium-4 isotope ratio, commonly cited as evidence for a deep mantle source for the Yellowstone hotspot. However, much of the helium emitted from this region is actually radiogenic helium-4 produced within the crust by α-decay of uranium and thorium. Here we show, by combining gas emission rates with chemistry and isotopic analyses, that crustal helium-4 emission rates from Yellowstone exceed (by orders of magnitude) any conceivable rate of generation within the crust. It seems that helium has accumulated for (at least) many hundreds of millions of years in Archaean (more than 2.5 billion years old) cratonic rocks beneath Yellowstone, only to be liberated over the past two million years by intense crustal metamorphism induced by the Yellowstone hotspot. Our results demonstrate the extremes in variability of crustal helium efflux on geologic timescales and imply crustal-scale open-system behaviour of helium in tectonically and magmatically active regions.

  19. Prodigious degassing of a billion years of accumulated radiogenic helium at Yellowstone.

    PubMed

    Lowenstern, J B; Evans, W C; Bergfeld, D; Hunt, A G

    2014-02-20

    Helium is used as a critical tracer throughout the Earth sciences, where its relatively simple isotopic systematics is used to trace degassing from the mantle, to date groundwater and to time the rise of continents. The hydrothermal system at Yellowstone National Park is famous for its high helium-3/helium-4 isotope ratio, commonly cited as evidence for a deep mantle source for the Yellowstone hotspot. However, much of the helium emitted from this region is actually radiogenic helium-4 produced within the crust by α-decay of uranium and thorium. Here we show, by combining gas emission rates with chemistry and isotopic analyses, that crustal helium-4 emission rates from Yellowstone exceed (by orders of magnitude) any conceivable rate of generation within the crust. It seems that helium has accumulated for (at least) many hundreds of millions of years in Archaean (more than 2.5 billion years old) cratonic rocks beneath Yellowstone, only to be liberated over the past two million years by intense crustal metamorphism induced by the Yellowstone hotspot. Our results demonstrate the extremes in variability of crustal helium efflux on geologic timescales and imply crustal-scale open-system behaviour of helium in tectonically and magmatically active regions.

  20. Prodigious degassing of a billion years of accumulated radiogenic helium at Yellowstone

    USGS Publications Warehouse

    Lowenstern, Jacob B.; Evans, William C.; Bergfeld, D.; Hunt, Andrew G.

    2014-01-01

    Helium is used as a critical tracer throughout the Earth sciences, where its relatively simple isotopic systematics is used to trace degassing from the mantle, to date groundwater and to time the rise of continents1. The hydrothermal system at Yellowstone National Park is famous for its high helium-3/helium-4 isotope ratio, commonly cited as evidence for a deep mantle source for the Yellowstone hotspot2. However, much of the helium emitted from this region is actually radiogenic helium-4 produced within the crust by α-decay of uranium and thorium. Here we show, by combining gas emission rates with chemistry and isotopic analyses, that crustal helium-4 emission rates from Yellowstone exceed (by orders of magnitude) any conceivable rate of generation within the crust. It seems that helium has accumulated for (at least) many hundreds of millions of years in Archaean (more than 2.5 billion years old) cratonic rocks beneath Yellowstone, only to be liberated over the past two million years by intense crustal metamorphism induced by the Yellowstone hotspot. Our results demonstrate the extremes in variability of crustal helium efflux on geologic timescales and imply crustal-scale open-system behaviour of helium in tectonically and magmatically active regions.

  1. Cooling and exhumation of continents at billion-year time scales

    NASA Astrophysics Data System (ADS)

    Blackburn, T.; Bowring, S. A.; Perron, T.; Mahan, K. H.; Dudas, F. O.

    2011-12-01

    The oldest rocks on Earth are preserved within the continental lithosphere, where assembled fragments of ancient orogenic belts have survived erosion and destruction by plate tectonic and surface processes for billions of years. Though the rate of orogenic exhumation and erosion has been measured for segments of an orogenic history, it remains unclear how these exhumation rates have changed over the lifetime of any terrane. Because the exhumation of the lithospheric surface has a direct effect on the rate of heat loss within the lithosphere, a continuous record of lithosphere exhumation can be reconstructed through the use of thermochronology. Thermochronologic studies have typically employed systems sensitive to cooling at temperatures <300 °C, such as the (U-Th)/He and 40Ar/39Ar systems. This largely restricts their application to measuring cooling in rocks from the outer 10 km of the Earth's crust, resulting in a thermal history that is controlled by either upper crustal flexure and faulting and/or isotherm inflections related to surface topography. Combining these biases with the uplift, erosion and recycling of these shallow rocks results in a poor preservation potential of any long-term record. Here, an ancient and long-term record of lithosphere exhumation is constructed using U-Pb thermochronology, a geochronologic system sensitive to cooling at temperatures found at 20-50 km depth (400-650 °C). Lower crustal xenoliths provide material that resided at these depths for billions of years or more, recording a thermal history that is buried deep enough to remain insensitive to upper crustal deformation and instead is dominated by the vertical motions of the continents. We show how this temperature-sensitive system can produce a long-term integrated measure of continental exhumation and erosion. Preserved beneath Phanerozoic sedimentary rocks within Montana, USA, the Great Falls Tectonic Zone formed when two Archean cratons, the Wyoming Province and Medicine

  2. Analogues of primeval galaxies two billion years after the Big Bang

    NASA Astrophysics Data System (ADS)

    Amorín, Ricardo; Fontana, Adriano; Pérez-Montero, Enrique; Castellano, Marco; Guaita, Lucia; Grazian, Andrea; Fèvre, Olivier Le; Ribeiro, Bruno; Schaerer, Daniel; Tasca, Lidia A. M.; Thomas, Romain; Bardelli, Sandro; Cassarà, Letizia; Cassata, Paolo; Cimatti, Andrea; Contini, Thierry; Barros, Stephane De; Garilli, Bianca; Giavalisco, Mauro; Hathi, Nimish; Koekemoer, Anton; Le Brun, Vincent; Lemaux, Brian C.; Maccagni, Dario; Pentericci, Laura; Pforr, Janine; Talia, Margherita; Tresse, Laurence; Vanzella, Eros; Vergani, Daniela; Zamorani, Giovanni; Zucca, Elena; Merlin, Emiliano

    2017-03-01

    Deep observations are revealing a growing number of young galaxies in the first billion years of cosmic time1. Compared to typical galaxies at later times, they show more extreme emission-line properties2, higher star formation rates3, lower masses4, and smaller sizes5. However, their faintness precludes studies of their chemical abundances and ionization conditions, strongly limiting our understanding of the physics driving early galaxy build-up and metal enrichment. Here we study a rare population of ultraviolet-selected, low-luminosity galaxies at redshift 2.4 < z < 3.5 that exhibit all the rest-frame properties expected from primeval galaxies. These low-mass, highly compact systems are rapidly forming galaxies able to double their stellar mass in only a few tens of millions of years. They are characterized by very blue ultraviolet spectra with weak absorption features and bright nebular emission lines, which imply hard radiation fields from young hot massive stars6,7. Their highly ionized gas phase has strongly sub-solar carbon and oxygen abundances, with metallicities more than a factor of two lower than that found in typical galaxies of similar mass and star formation rate at z≤2.58. These young galaxies reveal an early and short stage in the assembly of their galactic structures and their chemical evolution, a vigorous phase that is likely to be dominated by the effects of gas-rich mergers, accretion of metal-poor gas and strong outflows.

  3. The controversial "Cambrian" fossils of the Vindhyan are real but more than a billion years older.

    PubMed

    Bengtson, Stefan; Belivanova, Veneta; Rasmussen, Birger; Whitehouse, Martin

    2009-05-12

    The age of the Vindhyan sedimentary basin in central India is controversial, because geochronology indicating early Proterozoic ages clashes with reports of Cambrian fossils. We present here an integrated paleontologic-geochronologic investigation to resolve this conundrum. New sampling of Lower Vindhyan phosphoritic stromatolitic dolomites from the northern flank of the Vindhyans confirms the presence of fossils most closely resembling those found elsewhere in Cambrian deposits: annulated tubes, embryo-like globules with polygonal surface pattern, and filamentous and coccoidal microbial fabrics similar to Girvanella and Renalcis. None of the fossils, however, can be ascribed to uniquely Cambrian or Ediacaran taxa. Indeed, the embryo-like globules are not interpreted as fossils at all but as former gas bubbles trapped in mucus-rich cyanobacterial mats. Direct dating of the same fossiliferous phosphorite yielded a Pb-Pb isochron of 1,650 +/- 89 (2sigma) million years ago, confirming the Paleoproterozoic age of the fossils. New U-Pb geochronology of zircons from tuffaceous mudrocks in the Lower Vindhyan Porcellanite Formation on the southern flank of the Vindhyans give comparable ages. The Vindhyan phosphorites provide a window of 3-dimensionally preserved Paleoproterozoic fossils resembling filamentous and coccoidal cyanobacteria and filamentous eukaryotic algae, as well as problematic forms. Like Neoproterozoic phosphorites a billion years later, the Vindhyan deposits offer important new insights into the nature and diversity of life, and in particular, the early evolution of multicellular eukaryotes.

  4. Rapid oxygenation of Earth's atmosphere 2.33 billion years ago.

    PubMed

    Luo, Genming; Ono, Shuhei; Beukes, Nicolas J; Wang, David T; Xie, Shucheng; Summons, Roger E

    2016-05-01

    Molecular oxygen (O2) is, and has been, a primary driver of biological evolution and shapes the contemporary landscape of Earth's biogeochemical cycles. Although "whiffs" of oxygen have been documented in the Archean atmosphere, substantial O2 did not accumulate irreversibly until the Early Paleoproterozoic, during what has been termed the Great Oxygenation Event (GOE). The timing of the GOE and the rate at which this oxygenation took place have been poorly constrained until now. We report the transition (that is, from being mass-independent to becoming mass-dependent) in multiple sulfur isotope signals of diagenetic pyrite in a continuous sedimentary sequence in three coeval drill cores in the Transvaal Supergroup, South Africa. These data precisely constrain the GOE to 2.33 billion years ago. The new data suggest that the oxygenation occurred rapidly-within 1 to 10 million years-and was followed by a slower rise in the ocean sulfate inventory. Our data indicate that a climate perturbation predated the GOE, whereas the relationships among GOE, "Snowball Earth" glaciation, and biogeochemical cycling will require further stratigraphic correlation supported with precise chronologies and paleolatitude reconstructions.

  5. Constraints on the first billion years of the geodynamo from paleointensity studies of zircons

    NASA Astrophysics Data System (ADS)

    Tarduno, John; Cottrell, Rory; Davis, William

    2014-05-01

    Several lines of reasoning, including new ideas on core thermal conductivity, suggest that onset of a strong geomagnetic field might have been delayed by one billion years (or more) after the lunar forming event. Here we extend the Proterozoic/Archean to Paleoarchean record of the geomagnetic field constrained by single crystal paleointensity (SCP) analyses (Tarduno et al., Science, 2010) to older times using zircons containing minute magnetic inclusions. Specifically, we focus on samples from the Jack Hills (Yilgarn Craton, Western Australia). We employ a CO2 laser demagnetization system and a small bore (6.3 mm) 3-component DC SQUID magnetometer; the latter offers the highest currently available moment resolution. Sample age is analyzed using SHRIMP U-Pb geochronology. Preliminary data support the presence of a relatively strong Paleoarchean field produced by a core dynamo, extending the known record by at least 100 million years, to approximately 3.55 Ga. These data only serve to exacerbate the apparent problem posed by the presence of a Paleoarchean dynamo. Alternative dynamo driving mechanisms, or efficient core/lowermost mantle heat loss processes unique to the Paleoarchean (and older times) might have been at work. We will discuss these processes, and our efforts to study even older Eoarchean-Hadean zircons.

  6. A redox-stratified ocean 3.2 billion years ago

    NASA Astrophysics Data System (ADS)

    Satkoski, Aaron M.; Beukes, Nicolas J.; Li, Weiqiang; Beard, Brian L.; Johnson, Clark M.

    2015-11-01

    Before the Great Oxidation Event (GOE) 2.4-2.2 billion years ago it has been traditionally thought that oceanic water columns were uniformly anoxic due to a lack of oxygen-producing microorganisms. Recently, however, it has been proposed that transient oxygenation of shallow seawater occurred between 2.8 and 3.0 billion years ago. Here, we present a novel combination of stable Fe and radiogenic U-Th-Pb isotope data that demonstrate significant oxygen contents in the shallow oceans at 3.2 Ga, based on analysis of the Manzimnyama Banded Iron Formation (BIF), Fig Tree Group, South Africa. This unit is exceptional in that proximal, shallow-water and distal, deep-water facies are preserved. When compared to the distal, deep-water facies, the proximal samples show elevated U concentrations and moderately positive δ56Fe values, indicating vertical stratification in dissolved oxygen contents. Confirmation of oxidizing conditions using U abundances is robustly constrained using samples that have been closed to U and Pb mobility using U-Th-Pb geochronology. Although redox-sensitive elements have been commonly used in ancient rocks to infer redox conditions, post-depositional element mobility has been rarely tested, and U-Th-Pb geochronology can constrain open- or closed-system behavior. The U abundances and δ56Fe values of the Manzimnyama BIF suggest the proximal, shallow-water samples record precipitation under stronger oxidizing conditions compared to the distal deeper-water facies, which in turn indicates the existence of a discrete redox boundary between deep and shallow ocean waters at this time; this work, therefore, documents the oldest known preserved marine redox gradient in the rock record. The relative enrichment of O2 in the upper water column is likely due to the existence of oxygen-producing microorganisms such as cyanobacteria. These results provide a new approach for identifying free oxygen in Earth's ancient oceans, including confirming the age of redox

  7. Iapetus: 4.5 Billion Years of Contamination by Phoebe Dust

    NASA Astrophysics Data System (ADS)

    Hamilton, Douglas P.

    1997-07-01

    One of the strangest satellites in the Solar System is Saturn's tidally-locked Iapetus which has a bright white trailing hemisphere and a jet-black leading face. It has long been suspected that dark dusty debris, originating from Saturn's outermost satellite Phoebe and brought inward by Poynting-Robertson drag, is responsible for Iapetus' striking albedo asymmetry. The Phoebe-dust model is very compelling because it naturally explains why the leading face of Iapetus, the side that is receiving dust from Phoebe, is dark. The model has not gained universal acceptance, however, primarily due to the following dynamical problems: i) the distribution of dark material on Iapetus does not precisely match predicted contours of constant dust flux from Phoebe, ii) there are dark-floored craters in Iapetus' high-albedo hemisphere, and iii) Iapetus' North pole is brighter than parts of the trailing hemisphere. These problems are greatly reduced with the realization that Iapetus took nearly a billion years to become tidally locked to Saturn. I suggest the following scenario for the origin of the black/while dichotomy on Iapetus. Phoebe was probably captured early in the Solar System's history, well before Iapetus' spin slowed to its present synchronous rate. While Iapetus was spinning rapidly, dust from Phoebe accumulated at all longitudes on Iapetus uniformly. The accumulation was greatest near Iapetus' equator and decreased with roughly a cosine dependence toward the poles where the dust flux was lowest. After Iapetus became tidally locked, its trailing side was shielded from Phoebe dust, and volatile ice accumulated there burying the dark Phoebe material. Large impacts on the trailing side have dredged up some ancient Phoebe debris, creating the dark-floored craters. In addition, impacts have mixed dark debris with icy material, thereby lowering the albedo of the trailing side. Iapetus' poles are the brightest parts of the satellite simply because little Phoebe dust ever

  8. Galaxy evolution. Evidence for mature bulges and an inside-out quenching phase 3 billion years after the Big Bang.

    PubMed

    Tacchella, S; Carollo, C M; Renzini, A; Förster Schreiber, N M; Lang, P; Wuyts, S; Cresci, G; Dekel, A; Genzel, R; Lilly, S J; Mancini, C; Newman, S; Onodera, M; Shapley, A; Tacconi, L; Woo, J; Zamorani, G

    2015-04-17

    Most present-day galaxies with stellar masses ≥10(11) solar masses show no ongoing star formation and are dense spheroids. Ten billion years ago, similarly massive galaxies were typically forming stars at rates of hundreds solar masses per year. It is debated how star formation ceased, on which time scales, and how this "quenching" relates to the emergence of dense spheroids. We measured stellar mass and star-formation rate surface density distributions in star-forming galaxies at redshift 2.2 with ~1-kiloparsec resolution. We find that, in the most massive galaxies, star formation is quenched from the inside out, on time scales less than 1 billion years in the inner regions, up to a few billion years in the outer disks. These galaxies sustain high star-formation activity at large radii, while hosting fully grown and already quenched bulges in their cores.

  9. A Massive Galaxy in Its Core Formation Phase Three Billion Years After the Big Bang

    NASA Technical Reports Server (NTRS)

    Nelson, Erica; van Dokkum, Pieter; Franx, Marijn; Brammer, Gabriel; Momcheva, Ivelina; Schreiber, Natascha M. Forster; da Cunha, Elisabete; Tacconi, Linda; Bezanson, Rachel; Kirkpatrick, Allison; Leja, Joel; Rix, Hans-Walter; Skelton, Rosalind; van der Wel, Arjen; Whitaker, Katherine; Wuyts, Stijn

    2014-01-01

    Most massive galaxies are thought to have formed their dense stellar cores at early cosmic epochs. However, cores in their formation phase have not yet been observed. Previous studies have found galaxies with high gas velocity dispersions or small apparent sizes but so far no objects have been identified with both the stellar structure and the gas dynamics of a forming core. Here we present a candidate core in formation 11 billion years ago, at z = 2.3. GOODS-N-774 has a stellar mass of 1.0 × 10 (exp 11) solar mass, a half-light radius of 1.0 kpc, and a star formation rate of 90 (sup +45 / sub -20) solar mass/yr. The star forming gas has a velocity dispersion 317 plus or minus 30 km/s, amongst the highest ever measured. It is similar to the stellar velocity dispersions of the putative descendants of GOODS-N-774, compact quiescent galaxies at z is approximately equal to 2 (exp 8-11) and giant elliptical galaxies in the nearby Universe. Galaxies such as GOODS-N-774 appear to be rare; however, from the star formation rate and size of the galaxy we infer that many star forming cores may be heavily obscured, and could be missed in optical and near-infrared surveys.

  10. A large neutral fraction of cosmic hydrogen a billion years after the Big Bang.

    PubMed

    Wyithe, J Stuart B; Loeb, Abraham

    2004-02-26

    The fraction of ionized hydrogen left over from the Big Bang provides evidence for the time of formation of the first stars and quasar black holes in the early Universe; such objects provide the high-energy photons necessary to ionize hydrogen. Spectra of the two most distant known quasars show nearly complete absorption of photons with wavelengths shorter than the Lyman alpha transition of neutral hydrogen, indicating that hydrogen in the intergalactic medium (IGM) had not been completely ionized at a redshift of z approximately 6.3, about one billion years after the Big Bang. Here we show that the IGM surrounding these quasars had a neutral hydrogen fraction of tens of per cent before the quasar activity started, much higher than the previous lower limits of approximately 0.1 per cent. Our results, when combined with the recent inference of a large cumulative optical depth to electron scattering after cosmological recombination therefore suggest the presence of a second peak in the mean ionization history of the Universe.

  11. A role for copper in protozoan grazing - two billion years selecting for bacterial copper resistance.

    PubMed

    Hao, Xiuli; Lüthje, Freja; Rønn, Regin; German, Nadezhda A; Li, Xuanji; Huang, Fuyi; Kisaka, Javan; Huffman, David; Alwathnani, Hend A; Zhu, Yong-Guan; Rensing, Christopher

    2016-11-01

    The Great Oxidation Event resulted in integration of soft metals in a wide range of biochemical processes including, in our opinion, killing of bacteria by protozoa. Compared to pressure from anthropologic copper contamination, little is known on impacts of protozoan predation on maintenance of copper resistance determinants in bacteria. To evaluate the role of copper and other soft metals in predatory mechanisms of protozoa, we examined survival of bacteria mutated in different transition metal efflux or uptake systems in the social amoeba Dictyostelium discoideum. Our data demonstrated a strong correlation between the presence of copper/zinc efflux as well as iron/manganese uptake, and bacterial survival in amoebae. The growth of protozoa, in turn, was dependent on bacterial copper sensitivity. The phagocytosis of bacteria induced upregulation of Dictyostelium genes encoding the copper uptake transporter p80 and a triad of Cu(I)-translocating PIB -type ATPases. Accumulated Cu(I) in Dictyostelium was monitored using a copper biosensor bacterial strain. Altogether, our data demonstrate that Cu(I) is ultimately involved in protozoan predation of bacteria, supporting our hypothesis that protozoan grazing selected for the presence of copper resistance determinants for about two billion years.

  12. Potentially biogenic carbon preserved in a 4.1 billion-year-old zircon.

    PubMed

    Bell, Elizabeth A; Boehnke, Patrick; Harrison, T Mark; Mao, Wendy L

    2015-11-24

    Evidence of life on Earth is manifestly preserved in the rock record. However, the microfossil record only extends to ∼ 3.5 billion years (Ga), the chemofossil record arguably to ∼ 3.8 Ga, and the rock record to 4.0 Ga. Detrital zircons from Jack Hills, Western Australia range in age up to nearly 4.4 Ga. From a population of over 10,000 Jack Hills zircons, we identified one >3.8-Ga zircon that contains primary graphite inclusions. Here, we report carbon isotopic measurements on these inclusions in a concordant, 4.10 ± 0.01-Ga zircon. We interpret these inclusions as primary due to their enclosure in a crack-free host as shown by transmission X-ray microscopy and their crystal habit. Their δ(13)CPDB of -24 ± 5‰ is consistent with a biogenic origin and may be evidence that a terrestrial biosphere had emerged by 4.1 Ga, or ∼ 300 My earlier than has been previously proposed.

  13. Genetic Code Mutations: The Breaking of a Three Billion Year Invariance

    PubMed Central

    Mat, Wai-Kin; Xue, Hong; Wong, J. Tze-Fei

    2010-01-01

    The genetic code has been unchanging for some three billion years in its canonical ensemble of encoded amino acids, as indicated by the universal adoption of this ensemble by all known organisms. Code mutations beginning with the encoding of 4-fluoro-Trp by Bacillus subtilis, initially replacing and eventually displacing Trp from the ensemble, first revealed the intrinsic mutability of the code. This has since been confirmed by a spectrum of other experimental code alterations in both prokaryotes and eukaryotes. To shed light on the experimental conversion of a rigidly invariant code to a mutating code, the present study examined code mutations determining the propagation of Bacillus subtilis on Trp and 4-, 5- and 6-fluoro-tryptophans. The results obtained with the mutants with respect to cross-inhibitions between the different indole amino acids, and the growth effects of individual nutrient withdrawals rendering essential their biosynthetic pathways, suggested that oligogenic barriers comprising sensitive proteins which malfunction with amino acid analogues provide effective mechanisms for preserving the invariance of the code through immemorial time, and mutations of these barriers open up the code to continuous change. PMID:20808824

  14. Potentially biogenic carbon preserved in a 4.1 billion-year-old zircon

    DOE PAGES

    Bell, Elizabeth A.; Boehnke, Patrick; Harrison, T. Mark; ...

    2015-10-19

    Here, evidence of life on Earth is manifestly preserved in the rock record. However, the microfossil record only extends to ~3.5 billion years (Ga), the chemofossil record arguably to ~3.8 Ga, and the rock record to 4.0 Ga. Detrital zircons from Jack Hills, Western Australia range in age up to nearly 4.4 Ga. From a population of over 10,000 Jack Hills zircons, we identified one >3.8-Ga zircon that contains primary graphite inclusions. Here, we report carbon isotopic measurements on these inclusions in a concordant, 4.10 ± 0.01-Ga zircon. We interpret these inclusions as primary due to their enclosure in amore » crack-free host as shown by transmission X-ray microscopy and their crystal habit. Their δ13CPDB of –24 ± 5‰ is consistent with a biogenic origin and may be evidence that a terrestrial biosphere had emerged by 4.1 Ga, or ~300 My earlier than has been previously proposed.« less

  15. Potentially biogenic carbon preserved in a 4.1 billion-year-old zircon

    SciTech Connect

    Bell, Elizabeth A.; Boehnke, Patrick; Harrison, T. Mark; Mao, Wendy L.

    2015-10-19

    Here, evidence of life on Earth is manifestly preserved in the rock record. However, the microfossil record only extends to ~3.5 billion years (Ga), the chemofossil record arguably to ~3.8 Ga, and the rock record to 4.0 Ga. Detrital zircons from Jack Hills, Western Australia range in age up to nearly 4.4 Ga. From a population of over 10,000 Jack Hills zircons, we identified one >3.8-Ga zircon that contains primary graphite inclusions. Here, we report carbon isotopic measurements on these inclusions in a concordant, 4.10 ± 0.01-Ga zircon. We interpret these inclusions as primary due to their enclosure in a crack-free host as shown by transmission X-ray microscopy and their crystal habit. Their δ13CPDB of –24 ± 5‰ is consistent with a biogenic origin and may be evidence that a terrestrial biosphere had emerged by 4.1 Ga, or ~300 My earlier than has been previously proposed.

  16. Enhanced cellular preservation by clay minerals in 1 billion-year-old lakes.

    PubMed

    Wacey, David; Saunders, Martin; Roberts, Malcolm; Menon, Sarath; Green, Leonard; Kong, Charlie; Culwick, Timothy; Strother, Paul; Brasier, Martin D

    2014-07-28

    Organic-walled microfossils provide the best insights into the composition and evolution of the biosphere through the first 80 percent of Earth history. The mechanism of microfossil preservation affects the quality of biological information retained and informs understanding of early Earth palaeo-environments. We here show that 1 billion-year-old microfossils from the non-marine Torridon Group are remarkably preserved by a combination of clay minerals and phosphate, with clay minerals providing the highest fidelity of preservation. Fe-rich clay mostly occurs in narrow zones in contact with cellular material and is interpreted as an early microbially-mediated phase enclosing and replacing the most labile biological material. K-rich clay occurs within and exterior to cell envelopes, forming where the supply of Fe had been exhausted. Clay minerals inter-finger with calcium phosphate that co-precipitated with the clays in the sub-oxic zone of the lake sediments. This type of preservation was favoured in sulfate-poor environments where Fe-silicate precipitation could outcompete Fe-sulfide formation. This work shows that clay minerals can provide an exceptionally high fidelity of microfossil preservation and extends the known geological range of this fossilization style by almost 500 Ma. It also suggests that the best-preserved microfossils of this time may be found in low-sulfate environments.

  17. Rapid oxygenation of Earth’s atmosphere 2.33 billion years ago

    PubMed Central

    Luo, Genming; Ono, Shuhei; Beukes, Nicolas J.; Wang, David T.; Xie, Shucheng; Summons, Roger E.

    2016-01-01

    Molecular oxygen (O2) is, and has been, a primary driver of biological evolution and shapes the contemporary landscape of Earth’s biogeochemical cycles. Although “whiffs” of oxygen have been documented in the Archean atmosphere, substantial O2 did not accumulate irreversibly until the Early Paleoproterozoic, during what has been termed the Great Oxygenation Event (GOE). The timing of the GOE and the rate at which this oxygenation took place have been poorly constrained until now. We report the transition (that is, from being mass-independent to becoming mass-dependent) in multiple sulfur isotope signals of diagenetic pyrite in a continuous sedimentary sequence in three coeval drill cores in the Transvaal Supergroup, South Africa. These data precisely constrain the GOE to 2.33 billion years ago. The new data suggest that the oxygenation occurred rapidly—within 1 to 10 million years—and was followed by a slower rise in the ocean sulfate inventory. Our data indicate that a climate perturbation predated the GOE, whereas the relationships among GOE, “Snowball Earth” glaciation, and biogeochemical cycling will require further stratigraphic correlation supported with precise chronologies and paleolatitude reconstructions. PMID:27386544

  18. Potentially biogenic carbon preserved in a 4.1 billion-year-old zircon

    PubMed Central

    Bell, Elizabeth A.; Harrison, T. Mark; Mao, Wendy L.

    2015-01-01

    Evidence of life on Earth is manifestly preserved in the rock record. However, the microfossil record only extends to ∼3.5 billion years (Ga), the chemofossil record arguably to ∼3.8 Ga, and the rock record to 4.0 Ga. Detrital zircons from Jack Hills, Western Australia range in age up to nearly 4.4 Ga. From a population of over 10,000 Jack Hills zircons, we identified one >3.8-Ga zircon that contains primary graphite inclusions. Here, we report carbon isotopic measurements on these inclusions in a concordant, 4.10 ± 0.01-Ga zircon. We interpret these inclusions as primary due to their enclosure in a crack-free host as shown by transmission X-ray microscopy and their crystal habit. Their δ13CPDB of −24 ± 5‰ is consistent with a biogenic origin and may be evidence that a terrestrial biosphere had emerged by 4.1 Ga, or ∼300 My earlier than has been previously proposed. PMID:26483481

  19. Enhanced cellular preservation by clay minerals in 1 billion-year-old lakes

    PubMed Central

    Wacey, David; Saunders, Martin; Roberts, Malcolm; Menon, Sarath; Green, Leonard; Kong, Charlie; Culwick, Timothy; Strother, Paul; Brasier, Martin D.

    2014-01-01

    Organic-walled microfossils provide the best insights into the composition and evolution of the biosphere through the first 80 percent of Earth history. The mechanism of microfossil preservation affects the quality of biological information retained and informs understanding of early Earth palaeo-environments. We here show that 1 billion-year-old microfossils from the non-marine Torridon Group are remarkably preserved by a combination of clay minerals and phosphate, with clay minerals providing the highest fidelity of preservation. Fe-rich clay mostly occurs in narrow zones in contact with cellular material and is interpreted as an early microbially-mediated phase enclosing and replacing the most labile biological material. K-rich clay occurs within and exterior to cell envelopes, forming where the supply of Fe had been exhausted. Clay minerals inter-finger with calcium phosphate that co-precipitated with the clays in the sub-oxic zone of the lake sediments. This type of preservation was favoured in sulfate-poor environments where Fe-silicate precipitation could outcompete Fe-sulfide formation. This work shows that clay minerals can provide an exceptionally high fidelity of microfossil preservation and extends the known geological range of this fossilization style by almost 500 Ma. It also suggests that the best-preserved microfossils of this time may be found in low-sulfate environments. PMID:25068404

  20. Archean rocks in antarctica: 2.5-billion-year uranium-lead ages of pegmatites in enderby land.

    PubMed

    Grew, E S; Manton, W I

    1979-10-26

    Uranium-lead isotopic data indicate that the granulite-facies Napier complex of Enderby Land, Antarctica, was cut by charnockitic pegmatites 2.5 billion years ago and by pegmatites lacking hypersthene 0.52 billion years ago. The 4-bil-lion-years lead-lead ages (whole rock) reported for the Napier complex are rejected since these leads developed in three stages. Reconstructions of Gondwanaland suggest that the Napier complex may be a continuation of the Archean granulitic terrain of southern India.

  1. Megascopic Eukaryotic Algae from the 2.1-Billion-Year-Old Negaunee Iron-Formation, Michigan

    NASA Astrophysics Data System (ADS)

    Han, Tsu-Ming; Runnegar, Bruce

    1992-07-01

    Hundreds of specimens of spirally coiled, megascopic, carbonaceous fossils resembling Grypania spiralis (Walcott), have been found in the 2.1-billion-year-old Negaunee Iron-Formation at the Empire Mine, near Marquette, Michigan. This occurrence of Grypania is 700 million to 1000 million years older than fossils from previously known sites in Montana, China, and India. As Grypania appears to have been a photosynthetic alga, this discovery places the origin of organelle-bearing eukaryotic cells prior to 2.1 billion years ago.

  2. The formation of submillimetre-bright galaxies from gas infall over a billion years.

    PubMed

    Narayanan, Desika; Turk, Matthew; Feldmann, Robert; Robitaille, Thomas; Hopkins, Philip; Thompson, Robert; Hayward, Christopher; Ball, David; Faucher-Giguère, Claude-André; Kereš, Dušan

    2015-09-24

    Submillimetre-bright galaxies at high redshift are the most luminous, heavily star-forming galaxies in the Universe and are characterized by prodigious emission in the far-infrared, with a flux of at least five millijanskys at a wavelength of 850 micrometres. They reside in haloes with masses about 10(13) times that of the Sun, have low gas fractions compared to main-sequence disks at a comparable redshift, trace complex environments and are not easily observable at optical wavelengths. Their physical origin remains unclear. Simulations have been able to form galaxies with the requisite luminosities, but have otherwise been unable to simultaneously match the stellar masses, star formation rates, gas fractions and environments. Here we report a cosmological hydrodynamic galaxy formation simulation that is able to form a submillimetre galaxy that simultaneously satisfies the broad range of observed physical constraints. We find that groups of galaxies residing in massive dark matter haloes have increasing rates of star formation that peak at collective rates of about 500-1,000 solar masses per year at redshifts of two to three, by which time the interstellar medium is sufficiently enriched with metals that the region may be observed as a submillimetre-selected system. The intense star formation rates are fuelled in part by the infall of a reservoir gas supply enabled by stellar feedback at earlier times, not through major mergers. With a lifetime of nearly a billion years, our simulations show that the submillimetre-bright phase of high-redshift galaxies is prolonged and associated with significant mass buildup in early-Universe proto-clusters, and that many submillimetre-bright galaxies are composed of numerous unresolved components (for which there is some observational evidence).

  3. Atmospheric sulfur rearrangement 2.7 billion years ago: Evidence for oxygenic photosynthesis

    NASA Astrophysics Data System (ADS)

    Kurzweil, Florian; Claire, Mark; Thomazo, Christophe; Peters, Marc; Hannington, Mark; Strauss, Harald

    2013-03-01

    Mass-independently fractionated sulfur isotopes (MIF-S) provide strong evidence for an anoxic atmosphere during the Archean. Moreover, the temporal evolution of MIF-S shows increasing magnitudes between 2.7 and 2.5 Ga until the start of the Great Oxidation Event (G.O.E.) at around 2.4 Ga. The conclusion of a completely anoxic atmosphere up to the G.O.E. is in contrast to recent studies on redox-sensitive elements, which suggest slightly oxidizing conditions during continental weathering already several hundred million years prior to the G.O.E. In order to investigate this apparent inconsistency, we present multiple sulfur isotopes for 2.71 Ga pyritic black shales derived from the Kidd Creek area, Ontario, Canada. These samples display high positive Δ33S values up to 3.8‰ and the typical late Archean slope in Δ36S/Δ33S of -0.9. In contrast, the time period before (3.2-2.73 Ga) is characterized by greatly attenuated MIF-S magnitudes and a slope in Δ36S/Δ33S of -1.5. We attribute the increase in Δ33S magnitude as well as the contemporaneous change in the slope of Δ36S/Δ33S to changes in the relative reaction rate of different MIF-S source reactions and changes in atmospheric sulfur exit channels. Both of these are dependent on atmospheric CH4:CO2 and O2 mixing ratios. We propose a distinct change in atmospheric composition at 2.7 Ga resulting from increased fluxes of oxygen and methane as the best explanation for the observed Neoarchean MIF-S record. Our data and modeling results suggest that oxygenic photosynthesis was a major contributor to primary productivity 2.7 billion years ago.

  4. Herschel-ATLAS: rapid evolution of dust in galaxies over the last 5 billion years

    NASA Astrophysics Data System (ADS)

    Dunne, L.; Gomez, H. L.; da Cunha, E.; Charlot, S.; Dye, S.; Eales, S.; Maddox, S. J.; Rowlands, K.; Smith, D. J. B.; Auld, R.; Baes, M.; Bonfield, D. G.; Bourne, N.; Buttiglione, S.; Cava, A.; Clements, D. L.; Coppin, K. E. K.; Cooray, A.; Dariush, A.; de Zotti, G.; Driver, S.; Fritz, J.; Geach, J.; Hopwood, R.; Ibar, E.; Ivison, R. J.; Jarvis, M. J.; Kelvin, L.; Pascale, E.; Pohlen, M.; Popescu, C.; Rigby, E. E.; Robotham, A.; Rodighiero, G.; Sansom, A. E.; Serjeant, S.; Temi, P.; Thompson, M.; Tuffs, R.; van der Werf, P.; Vlahakis, C.

    2011-10-01

    We present the first direct and unbiased measurement of the evolution of the dust mass function of galaxies over the past 5 billion years of cosmic history using data from the Science Demonstration Phase of the Herschel-Astrophysical Terahertz Large Area Survey (Herschel-ATLAS). The sample consists of galaxies selected at 250 ?m which have reliable counterparts from the Sloan Digital Sky Survey (SDSS) at z < 0.5, and contains 1867 sources. Dust masses are calculated using both a single-temperature grey-body model for the spectral energy distribution and also a model with multiple temperature components. The dust temperature for either model shows no trend with redshift. Splitting the sample into bins of redshift reveals a strong evolution in the dust properties of the most massive galaxies. At z= 0.4-0.5, massive galaxies had dust masses about five times larger than in the local Universe. At the same time, the dust-to-stellar mass ratio was about three to four times larger, and the optical depth derived from fitting the UV-sub-mm data with an energy balance model was also higher. This increase in the dust content of massive galaxies at high redshift is difficult to explain using standard dust evolution models and requires a rapid gas consumption time-scale together with either a more top-heavy initial mass function (IMF), efficient mantle growth, less dust destruction or combinations of all three. This evolution in dust mass is likely to be associated with a change in overall interstellar medium mass, and points to an enhanced supply of fuel for star formation at earlier cosmic epochs.

  5. Searching for the birthplaces of open clusters with ages of several billion years

    NASA Astrophysics Data System (ADS)

    Acharova, I. A.; Shevtsova, E. S.

    2016-01-01

    We discuss the possibility of finding the birthplaces of open clusters (OC) with ages of several billion years. The proposed method is based on the comparison of the results of the chemical evolution modeling of the Galactic disk with the parameters of the cluster. Five OCs older than 7 Gyr are known: NGC6791, BH176, Collinder 261, Berkeley 17, and Berkeley 39. The oxygen and iron abundances in NGC6791 and the oxygen abundance in BH176 are twice the solar level, the heavy-element abundances in other clusters are close to the corresponding solar values. According to chemical evolution models, at the time of the formation of the objects considered the regions where the oxygen and iron abundances reached the corresponding levels extended out to 5 kpc from the Galactic center.At present time theOCs considered are located several kpc from the Galactic center. Some of these clusters are located extremely high, about 1 kpc above the disk midplane, i.e., they have been subject to some mechanism that has carried them into orbits uncharacteristic of this type of objects. It follows from a comparison with the results of chemical evolution that younger clusters with ages of 4-5 Gyr, e.g., NGC1193,M67, and others, may have formed in a broad range of Galactocentric distances. Their large heights above the disk midplane is sufficient to suggest that these clusters have moved away from their likely birthplaces. Clusters are carried far away from the Galactic disk until the present time: about 40 clusters with ages from 0 to 2 Gyr are observed at heights ranging from 300 to 750 pc.

  6. Survival of Pure Disk Galaxies over the Last 8 Billion Years

    NASA Astrophysics Data System (ADS)

    Sachdeva, Sonali; Saha, Kanak

    2016-03-01

    Pure disk galaxies without any bulge component, i.e., bulges that are neither classical nor pseudo, seem to have escaped the effects of merger activity that are inherent to hierarchical galaxy formation models as well as strong internal secular evolution. We discover that a significant fraction (˜15%-18%) of disk galaxies in the Hubble Deep Field (0.4\\lt z\\lt 1.0) and in the local universe (0.02\\lt z\\lt 0.05) are such pure disk systems (PDSs). The spatial distribution of light in these PDSs is well-described by a single exponential function from the outskirts to the center and appears to have remained intact over the last 8 billion years, keeping the mean central surface brightness and scale-length nearly constant. These two disk parameters of PDSs are brighter and shorter, respectively, than those of disks which are part of disk galaxies with bulges. Since the fraction of PDSs, as well as their profile-defining parameters, do not change, this indicates that these galaxies have not witnessed either major mergers or multiple minor mergers since z˜ 1. However, there is a substantial increase in their total stellar mass and total size over the same time range. This suggests that smooth accretion of cold gas via cosmic filaments is the most probable mode of their evolutions. We speculate that PDSs are dynamically hotter and cushioned in massive dark matter halos, which may prevent them from undergoing strong secular evolution.

  7. The transition to a sulphidic ocean approximately 1.84 billion years ago.

    PubMed

    Poulton, Simon W; Fralick, Philip W; Canfield, Donald E

    2004-09-09

    The Proterozoic aeon (2.5 to 0.54 billion years (Gyr) ago) marks the time between the largely anoxic world of the Archean (> 2.5 Gyr ago) and the dominantly oxic world of the Phanerozoic (< 0.54 Gyr ago). The course of ocean chemistry through the Proterozoic has traditionally been explained by progressive oxygenation of the deep ocean in response to an increase in atmospheric oxygen around 2.3 Gyr ago. This postulated rise in the oxygen content of the ocean is in turn thought to have led to the oxidation of dissolved iron, Fe(II), thus ending the deposition of banded iron formations (BIF) around 1.8 Gyr ago. An alternative interpretation suggests that the increasing atmospheric oxygen levels enhanced sulphide weathering on land and the flux of sulphate to the oceans. This increased rates of sulphate reduction, resulting in Fe(II) removal in the form of pyrite as the oceans became sulphidic. Here we investigate sediments from the approximately 1.8-Gyr-old Animikie group, Canada, which were deposited during the final stages of the main global period of BIF deposition. This allows us to evaluate the two competing hypotheses for the termination of BIF deposition. We use iron-sulphur-carbon (Fe-S-C) systematics to demonstrate continued ocean anoxia after the final global deposition of BIF and show that a transition to sulphidic bottom waters was ultimately responsible for the termination of BIF deposition. Sulphidic conditions may have persisted until a second major rise in oxygen between 0.8 to 0.58 Gyr ago, possibly reducing global rates of primary production and arresting the pace of algal evolution.

  8. The transition to a sulphidic ocean ~ 1.84 billion years ago

    NASA Astrophysics Data System (ADS)

    Poulton, Simon W.; Fralick, Philip W.; Canfield, Donald E.

    2004-09-01

    The Proterozoic aeon (2.5 to 0.54 billion years (Gyr) ago) marks the time between the largely anoxic world of the Archean (> 2.5Gyr ago) and the dominantly oxic world of the Phanerozoic (< 0.54Gyr ago). The course of ocean chemistry through the Proterozoic has traditionally been explained by progressive oxygenation of the deep ocean in response to an increase in atmospheric oxygen around 2.3Gyr ago. This postulated rise in the oxygen content of the ocean is in turn thought to have led to the oxidation of dissolved iron, Fe(II), thus ending the deposition of banded iron formations (BIF) around 1.8Gyr ago. An alternative interpretation suggests that the increasing atmospheric oxygen levels enhanced sulphide weathering on land and the flux of sulphate to the oceans. This increased rates of sulphate reduction, resulting in Fe(II) removal in the form of pyrite as the oceans became sulphidic. Here we investigate sediments from the ~1.8-Gyr-old Animikie group, Canada, which were deposited during the final stages of the main global period of BIF deposition. This allows us to evaluate the two competing hypotheses for the termination of BIF deposition. We use iron-sulphur-carbon (Fe-S-C) systematics to demonstrate continued ocean anoxia after the final global deposition of BIF and show that a transition to sulphidic bottom waters was ultimately responsible for the termination of BIF deposition. Sulphidic conditions may have persisted until a second major rise in oxygen between 0.8 to 0.58Gyr ago, possibly reducing global rates of primary production and arresting the pace of algal evolution.

  9. U.S. Health Care Costs from Birth Defects Total Almost $23 Billion a Year

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_163141.html U.S. Health Care Costs From Birth Defects Total Almost $23 Billion ... U.S. newborns have a serious birth defect, and health care costs tied to these difficulties total almost $23 ...

  10. Switching To Less-Expensive Blindness Drug Could Save Medicare Part B $18 Billion Over A Ten-Year Period

    PubMed Central

    Hutton, DW; Newman-Casey, PA; Tavag, M; Zacks, DN; Stein, JD

    2014-01-01

    The biologic drugs bevacizumab and ranibizumab have revolutionized treatment of diabetic macular edema and macular degeneration, leading causes of blindness. Ophthalmologic use of these drugs has increased, now accounting for roughly one-sixth of the Medicare Part B drug budget. Ranibizumab and bevacizumab have similar efficacy and potentially minor differences in adverse event rates, but at $2,023 per dose, ranibizumab costs forty times more than bevacizumab. Using modeling methods, we predict ten-year (2010–2020) population-level costs and health benefits of using bevacizumab and ranibizumab. Our results show that if all patients were treated with the less-expensive bevacizumab instead of current usage patterns, Medicare Part B, patients, and the health care system would save $18 billion, $4.6 billion, and $29 billion, respectively. Altering patterns of use with these therapies by encouraging bevacizumab use and hastening approval of biosimilar therapies would dramatically reduce spending without substantially affecting patient outcomes. PMID:24889941

  11. Strongly baryon-dominated disk galaxies at the peak of galaxy formation ten billion years ago

    NASA Astrophysics Data System (ADS)

    Genzel, R.; Schreiber, N. M. Förster; Übler, H.; Lang, P.; Naab, T.; Bender, R.; Tacconi, L. J.; Wisnioski, E.; Wuyts, S.; Alexander, T.; Beifiori, A.; Belli, S.; Brammer, G.; Burkert, A.; Carollo, C. M.; Chan, J.; Davies, R.; Fossati, M.; Galametz, A.; Genel, S.; Gerhard, O.; Lutz, D.; Mendel, J. T.; Momcheva, I.; Nelson, E. J.; Renzini, A.; Saglia, R.; Sternberg, A.; Tacchella, S.; Tadaki, K.; Wilman, D.

    2017-03-01

    In the cold dark matter cosmology, the baryonic components of galaxies—stars and gas—are thought to be mixed with and embedded in non-baryonic and non-relativistic dark matter, which dominates the total mass of the galaxy and its dark-matter halo. In the local (low-redshift) Universe, the mass of dark matter within a galactic disk increases with disk radius, becoming appreciable and then dominant in the outer, baryonic regions of the disks of star-forming galaxies. This results in rotation velocities of the visible matter within the disk that are constant or increasing with disk radius—a hallmark of the dark-matter model. Comparisons between the dynamical mass, inferred from these velocities in rotational equilibrium, and the sum of the stellar and cold-gas mass at the peak epoch of galaxy formation ten billion years ago, inferred from ancillary data, suggest high baryon fractions in the inner, star-forming regions of the disks. Although this implied baryon fraction may be larger than in the local Universe, the systematic uncertainties (owing to the chosen stellar initial-mass function and the calibration of gas masses) render such comparisons inconclusive in terms of the mass of dark matter. Here we report rotation curves (showing rotation velocity as a function of disk radius) for the outer disks of six massive star-forming galaxies, and find that the rotation velocities are not constant, but decrease with radius. We propose that this trend arises because of a combination of two main factors: first, a large fraction of the massive high-redshift galaxy population was strongly baryon-dominated, with dark matter playing a smaller part than in the local Universe; and second, the large velocity dispersion in high-redshift disks introduces a substantial pressure term that leads to a decrease in rotation velocity with increasing radius. The effect of both factors appears to increase with redshift. Qualitatively, the observations suggest that baryons in the early

  12. Strongly baryon-dominated disk galaxies at the peak of galaxy formation ten billion years ago.

    PubMed

    Genzel, R; Schreiber, N M Förster; Übler, H; Lang, P; Naab, T; Bender, R; Tacconi, L J; Wisnioski, E; Wuyts, S; Alexander, T; Beifiori, A; Belli, S; Brammer, G; Burkert, A; Carollo, C M; Chan, J; Davies, R; Fossati, M; Galametz, A; Genel, S; Gerhard, O; Lutz, D; Mendel, J T; Momcheva, I; Nelson, E J; Renzini, A; Saglia, R; Sternberg, A; Tacchella, S; Tadaki, K; Wilman, D

    2017-03-15

    In the cold dark matter cosmology, the baryonic components of galaxies-stars and gas-are thought to be mixed with and embedded in non-baryonic and non-relativistic dark matter, which dominates the total mass of the galaxy and its dark-matter halo. In the local (low-redshift) Universe, the mass of dark matter within a galactic disk increases with disk radius, becoming appreciable and then dominant in the outer, baryonic regions of the disks of star-forming galaxies. This results in rotation velocities of the visible matter within the disk that are constant or increasing with disk radius-a hallmark of the dark-matter model. Comparisons between the dynamical mass, inferred from these velocities in rotational equilibrium, and the sum of the stellar and cold-gas mass at the peak epoch of galaxy formation ten billion years ago, inferred from ancillary data, suggest high baryon fractions in the inner, star-forming regions of the disks. Although this implied baryon fraction may be larger than in the local Universe, the systematic uncertainties (owing to the chosen stellar initial-mass function and the calibration of gas masses) render such comparisons inconclusive in terms of the mass of dark matter. Here we report rotation curves (showing rotation velocity as a function of disk radius) for the outer disks of six massive star-forming galaxies, and find that the rotation velocities are not constant, but decrease with radius. We propose that this trend arises because of a combination of two main factors: first, a large fraction of the massive high-redshift galaxy population was strongly baryon-dominated, with dark matter playing a smaller part than in the local Universe; and second, the large velocity dispersion in high-redshift disks introduces a substantial pressure term that leads to a decrease in rotation velocity with increasing radius. The effect of both factors appears to increase with redshift. Qualitatively, the observations suggest that baryons in the early (high

  13. Switching to less expensive blindness drug could save medicare part B $18 billion over a ten-year period.

    PubMed

    Hutton, David; Newman-Casey, Paula Anne; Tavag, Mrinalini; Zacks, David; Stein, Joshua

    2014-06-01

    The biologic drugs bevacizumab and ranibizumab have revolutionized treatment of diabetic macular edema and neovascular age-related macular degeneration, leading causes of blindness. Ophthalmologic use of these drugs has increased and now accounts for roughly one-sixth of the Medicare Part B drug budget. The two drugs have similar efficacy and potentially minor differences in adverse-event rates; however, at $2,023 per dose, ranibizumab costs forty times more than bevacizumab. Using modeling methods, we predict ten-year (2010-20) population-level costs and health benefits of using bevacizumab and ranibizumab. Our results show that if all patients were treated with the less expensive bevacizumab instead of current usage patterns, savings would amount to $18 billion for Medicare Part B and nearly $5 billion for patients. With an additional $6 billion savings in other health care expenses, the total savings would be almost $29 billion. Altering patterns of use with these therapies by encouraging bevacizumab use and hastening approval of biosimilar therapies would dramatically reduce spending without substantially affecting patient outcomes.

  14. Air density 2.7 billion years ago limited to less than twice modern levels by fossil raindrop imprints.

    PubMed

    Som, Sanjoy M; Catling, David C; Harnmeijer, Jelte P; Polivka, Peter M; Buick, Roger

    2012-03-28

    According to the 'Faint Young Sun' paradox, during the late Archaean eon a Sun approximately 20% dimmer warmed the early Earth such that it had liquid water and a clement climate. Explanations for this phenomenon have invoked a denser atmosphere that provided warmth by nitrogen pressure broadening or enhanced greenhouse gas concentrations. Such solutions are allowed by geochemical studies and numerical investigations that place approximate concentration limits on Archaean atmospheric gases, including methane, carbon dioxide and oxygen. But no field data constraining ground-level air density and barometric pressure have been reported, leaving the plausibility of these various hypotheses in doubt. Here we show that raindrop imprints in tuffs of the Ventersdorp Supergroup, South Africa, constrain surface air density 2.7 billion years ago to less than twice modern levels. We interpret the raindrop fossils using experiments in which water droplets of known size fall at terminal velocity into fresh and weathered volcanic ash, thus defining a relationship between imprint size and raindrop impact momentum. Fragmentation following raindrop flattening limits raindrop size to a maximum value independent of air density, whereas raindrop terminal velocity varies as the inverse of the square root of air density. If the Archaean raindrops reached the modern maximum measured size, air density must have been less than 2.3 kg m(-3), compared to today's 1.2 kg m(-3), but because such drops rarely occur, air density was more probably below 1.3 kg m(-3). The upper estimate for air density renders the pressure broadening explanation possible, but it is improbable under the likely lower estimates. Our results also disallow the extreme CO(2) levels required for hot Archaean climates.

  15. ESA's billion star surveyor - Flight operations experience from Gaia's first 1.5 Years

    NASA Astrophysics Data System (ADS)

    Milligan, D.; Rudolph, A.; Whitehead, G.; Loureiro, T.; Serpell, E.; di Marco, F.; Marie, J.; Ecale, E.

    2016-10-01

    This paper details the initial in-flight mission operations experience from ESA's ultra-precise Gaia spacecraft. Tasked with mapping the positions and movements of 1 billion stars to unprecedented precision (to the 10 s of micro-arc-second level, comparable to the width of a coin on the Moon as viewed from Earth). ESA's Science cornerstone mission is expected to also discover and chart 100,000's of new objects including near Earth Asteroids, exoplanets, brown dwarfs and Quasars. After a flawless launch 19 Dec 2013, Gaia was brought the circa 1.5 million kms into L2 via a sequence of technically demanding orbit transfer manoeuvres using onboard thrusters in thrust vectoring mode. Starting in parallel to this, and lasting 6 months, the full spacecraft was commissioned and brought gradually up to the highest operational mode. A number of problems were detected and tackled during commissioning and early routine phase operations. An apparent dimming of the on-board laser and imaged stars, was tracked down to water ice building up inside the telescope enclosure. Also apparent was more straylight than expected. Elsewhere, a micro-propulsion thruster developed unexpected performance levels and a back-up chemical thruster suffered a failed latch valve. These issues, like several others, were dealt with and solved in a series of review meetings, in-orbit special operations and newly developed procedures and on-board software changes. After commissioning Gaia was working so well that it was producing approximately 45% more science data than originally foreseen, primarily since it was able to see stars fainter than required. The mission operations concept was quickly adapted to partially automate ground operations and increase ground station time to allow the full scientific potential of Gaia to be realised.

  16. 1.8 Billion Years of Detrital Zircon Recycling Calibrates a Refractory Part of Earth's Sedimentary Cycle.

    PubMed

    Hadlari, Thomas; Swindles, Graeme T; Galloway, Jennifer M; Bell, Kimberley M; Sulphur, Kyle C; Heaman, Larry M; Beranek, Luke P; Fallas, Karen M

    2015-01-01

    Detrital zircon studies are providing new insights on the evolution of sedimentary basins but the role of sedimentary recycling remains largely undefined. In a broad region of northwestern North America, this contribution traces the pathway of detrital zircon sand grains from Proterozoic sandstones through Phanerozoic strata and argues for multi-stage sedimentary recycling over more than a billion years. As a test of our hypothesis, integrated palynology and detrital zircon provenance provides clear evidence for erosion of Carboniferous strata in the northern Cordillera as a sediment source for Upper Cretaceous strata. Our results help to calibrate Earth's sedimentary cycle by showing that recycling dominates sedimentary provenance for the refractory mineral zircon.

  17. Tracing the effects of an enormous meteorite impact 3 billion years ago

    NASA Astrophysics Data System (ADS)

    Wendel, JoAnna

    2014-07-01

    The most well-known and popularized meteorite impact occurred 65 million years ago and left behind the Chicxulub crater, a feature more than 110 miles in diameter. Dust kicked up by the impact, which lingered in the atmosphere for years, may have helped kill all the nonavian dinosaurs along with three quarters of the world's plant and animal species.

  18. An age difference of two billion years between a metal-rich and a metal-poor globular cluster.

    PubMed

    Hansen, B M S; Kalirai, J S; Anderson, J; Dotter, A; Richer, H B; Rich, R M; Shara, M M; Fahlman, G G; Hurley, J R; King, I R; Reitzel, D; Stetson, P B

    2013-08-01

    Globular clusters trace the formation history of the spheroidal components of our Galaxy and other galaxies, which represent the bulk of star formation over the history of the Universe. The clusters exhibit a range of metallicities (abundances of elements heavier than helium), with metal-poor clusters dominating the stellar halo of the Galaxy, and higher-metallicity clusters found within the inner Galaxy, associated with the stellar bulge, or the thick disk. Age differences between these clusters can indicate the sequence in which the components of the Galaxy formed, and in particular which clusters were formed outside the Galaxy and were later engulfed along with their original host galaxies, and which were formed within it. Here we report an absolute age of 9.9 ± 0.7 billion years (at 95 per cent confidence) for the metal-rich globular cluster 47 Tucanae, determined by modelling the properties of the cluster's white-dwarf cooling sequence. This is about two billion years younger than has been inferred for the metal-poor cluster NGC 6397 from the same models, and provides quantitative evidence that metal-rich clusters like 47 Tucanae formed later than metal-poor halo clusters like NGC 6397.

  19. Earth's air pressure 2.7 billion years ago constrained to less than half of modern levels

    NASA Astrophysics Data System (ADS)

    Som, Sanjoy M.; Buick, Roger; Hagadorn, James W.; Blake, Tim S.; Perreault, John M.; Harnmeijer, Jelte P.; Catling, David C.

    2016-06-01

    How the Earth stayed warm several billion years ago when the Sun was considerably fainter is the long-standing problem of the `faint young Sun paradox'. Because of negligible O2 and only moderate CO2 levels in the Archaean atmosphere, methane has been invoked as an auxiliary greenhouse gas. Alternatively, pressure broadening in a thicker atmosphere with a N2 partial pressure around 1.6-2.4 bar could have enhanced the greenhouse effect. But fossilized raindrop imprints indicate that air pressure 2.7 billion years ago (Gyr) was below twice modern levels and probably below 1.1 bar, precluding such pressure enhancement. This result is supported by nitrogen and argon isotope studies of fluid inclusions in 3.0-3.5 Gyr rocks. Here, we calculate absolute Archaean barometric pressure using the size distribution of gas bubbles in basaltic lava flows that solidified at sea level ~2.7 Gyr in the Pilbara Craton, Australia. Our data indicate a surprisingly low surface atmospheric pressure of Patm = 0.23 +/- 0.23 (2σ) bar, and combined with previous studies suggests ~0.5 bar as an upper limit to late Archaean Patm. The result implies that the thin atmosphere was rich in auxiliary greenhouse gases and that Patm fluctuated over geologic time to a previously unrecognized extent.

  20. A spin-down clock for cool stars from observations of a 2.5-billion-year-old cluster.

    PubMed

    Meibom, Søren; Barnes, Sydney A; Platais, Imants; Gilliland, Ronald L; Latham, David W; Mathieu, Robert D

    2015-01-29

    The ages of the most common stars--low-mass (cool) stars like the Sun, and smaller--are difficult to derive because traditional dating methods use stellar properties that either change little as the stars age or are hard to measure. The rotation rates of all cool stars decrease substantially with time as the stars steadily lose their angular momenta. If properly calibrated, rotation therefore can act as a reliable determinant of their ages based on the method of gyrochronology. To calibrate gyrochronology, the relationship between rotation period and age must be determined for cool stars of different masses, which is best accomplished with rotation period measurements for stars in clusters with well-known ages. Hitherto, such measurements have been possible only in clusters with ages of less than about one billion years, and gyrochronology ages for older stars have been inferred from model predictions. Here we report rotation period measurements for 30 cool stars in the 2.5-billion-year-old cluster NGC 6819. The periods reveal a well-defined relationship between rotation period and stellar mass at the cluster age, suggesting that ages with a precision of order 10 per cent can be derived for large numbers of cool Galactic field stars.

  1. Plate tectonics 2.5 billion years ago: evidence at kolar, South India.

    PubMed

    Krogstad, E J; Balakrishnan, S; Mukhopadhyay, D K; Rajamani, V; Hanson, G N

    1989-03-10

    The Archean Kolar Schist Belt, south India, is a suture zone where two gneiss terranes and at least two amphibolite terranes with distinct histories were accrted. Amphibolites from the eastern and western sides of the schist belt have distinct incompatible element and isotopic characteristics sugesting that their volcanic protoliths were derived from dint mantle sources. The amphibolite and gneiss terranes were juxtaposed by horizontal compression and shearing between 2530 and 2420 million years ago (Ma) along a zone marked by the Kolar Schist Belt. This history of accretion of discrete crustal terranes resembles those of Phanerozoic convergent margins and thus suggests that plate tectonics operated on Earth by 2500 Ma.

  2. Plate tectonics 2.5 billion years ago - Evidence at Kolar, south India

    NASA Technical Reports Server (NTRS)

    Krogstad, E. J.; Hanson, G. N.; Balakrishnan, S.; Rajamani, V.; Mukhopadhyay, D. K.

    1989-01-01

    The Archean Kolar Schist Belt, south India, is a suture zone where two gneiss terranes and at least two amphibolite terranes with distinct histories were accreted. Amphibolites from the eastern and western sides of the schist belt have distinct incompatible element and isotopic characteristics suggesting that their volcanic protoliths were derived from different mantle sources. The amphibolite and gneiss terranes were juxtaposed by horizontal compression and shearing between 2530 and 2420 million years ago (Ma) along a zone marked by the Kolar Schist Belt. This history of accretion of discrete crustal terranes resembles those of Phanerozoic convergent margins and thus suggests that plate tectonics operated on earth by 2500 Ma.

  3. The Last Eight-billion Years of Intergalactic Si IV Evolution

    NASA Astrophysics Data System (ADS)

    Cooksey, Kathy L.; Prochaska, J. Xavier; Thom, Christopher; Chen, Hsiao-Wen

    2011-03-01

    We identified 24 Si IV absorption systems with z <~ 1 from a blind survey of 49 low-redshift quasars with archival Hubble Space Telescope ultraviolet spectra. We relied solely on the characteristic wavelength separation of the doublet to automatically detect candidates. After visual inspection, we defined a sample of 20 definite (group G = 1) and 4 "highly likely" (G = 2) doublets with rest equivalent widths Wr for both lines detected at ≥ 3{σ_{{W_{r}}}}. The absorber line density of the G = 1 doublets was {{{d}}{{N}}_{Si IV}}/{{d}X} = 1.4^{+0.4}_{-0.3} for log N(Si+3)>12.9. The best-fit power law to the G = 1 frequency distribution of column densities f(N(Si+3)) had normalization k = (1.2+0.5 -0.4) × 10-14 cm2 and slope α N = -1.6+0.3 -0.3. Using the power-law model of f(N(Si+3)), we measured the Si+3 mass density relative to the critical density: {Ω_{{{Si^{+3}}}}}= (3.7^{+2.8}_{-1.7}) × 10^{-8} for 13 <= log N(Si+3) <= 15. From Monte Carlo sampling of the distributions, we estimated our value to be a factor of 4.8+3.0 -1.9 higher than the 2 <= z <= 4.5 < {Ω_{{{Si^{+3}}}}}>. From a simple linear fit to {Ω_{{{Si^{+3}}}}} over the age of the universe, we estimated a slow and steady increase from z = 5.5 → 0 with {{d}}{Ω_{{{Si^{+3}}}}}/{{d}}t_age = (0.61± 0.23) × 10^{-8} Gyr^{-1}. We compared our ionic ratios {{N({{Si^{+3}}})}/{N({C^{+3}})}} to a 2 < z < 4.5 sample and concluded, from survival analysis, that the two populations are similar, with median < {{N({{Si^{+3}}})}/{N({C^{+3}})}}> = 0.16.

  4. The Archean Dongwanzi ophiolite complex, North China craton: 2.505-billion-year-old oceanic crust and mantle.

    PubMed

    Kusky, T M; Li, J H; Tucker, R D

    2001-05-11

    We report a thick, laterally extensive 2505 +/- 2.2-million-year-old (uranium-lead ratio in zircon) Archean ophiolite complex in the North China craton. Basal harzburgite tectonite is overlain by cumulate ultramafic rocks, a mafic-ultramafic transition zone of interlayered gabbro and ultramafic cumulates, compositionally layered olivine-gabbro and pyroxenite, and isotropic gabbro. A sheeted dike complex is rooted in the gabbro and overlain by a mixed dike-pillow lava section, chert, and banded iron formation. The documentation of a complete Archean ophiolite implies that mechanisms of oceanic crustal accretion similar to those of today were in operation by 2.5 billion years ago at divergent plate margins and that the temperature of the early mantle was not extremely elevated, as compared to the present-day temperature. Plate tectonic processes similar to those of the present must also have emplaced the ophiolite in a convergent margin setting.

  5. Illuminating the past 8 billion years of cold gas towards two gravitationally lensed quasars

    NASA Astrophysics Data System (ADS)

    Allison, J. R.; Moss, V. A.; Macquart, J.-P.; Curran, S. J.; Duchesne, S. W.; Mahony, E. K.; Sadler, E. M.; Whiting, M. T.; Bannister, K. W.; Chippendale, A. P.; Edwards, P. G.; Harvey-Smith, L.; Heywood, I.; Indermuehle, B. T.; Lenc, E.; Marvil, J.; McConnell, D.; Sault, R. J.

    2017-03-01

    Using the Boolardy Engineering Test Array of the Australian Square Kilometre Array Pathfinder (ASKAP BETA), we have carried out the first z = 0-1 survey for H I and OH absorption towards the gravitationally lensed quasars PKS B1830-211 and MG J0414+0534. Although we detected all previously reported intervening systems towards PKS B1830-211, in the case of MG J0414+0534, three systems were not found, indicating that the original identifications may have been confused with radio frequency interference. Given the sensitivity of our data, we find that our detection yield is consistent with the expected frequency of intervening H I systems estimated from previous surveys for 21-cm emission in nearby galaxies and z ∼ 3 damped Lyman α absorbers. We find spectral variability in the z = 0.886 face-on spiral galaxy towards PKS B1830-211 from observations undertaken with the Westerbork Synthesis Radio Telescope in 1997/1998 and ASKAP BETA in 2014/2015. The H I equivalent width varies by a few per cent over approximately yearly time-scales. This long-term spectral variability is correlated between the north-east and south-west images of the core, and with the total flux density of the source, implying that it is observationally coupled to intrinsic changes in the quasar. The absence of any detectable variability in the ratio of H I associated with the two core images is in stark contrast to the behaviour previously seen in the molecular lines. We therefore infer that coherent opaque H I structures in this galaxy are larger than the parsec-scale molecular clouds found at mm-wavelengths.

  6. Constraint on a varying proton-electron mass ratio 1.5 billion years after the big bang.

    PubMed

    Bagdonaite, J; Ubachs, W; Murphy, M T; Whitmore, J B

    2015-02-20

    A molecular hydrogen absorber at a lookback time of 12.4 billion years, corresponding to 10% of the age of the Universe today, is analyzed to put a constraint on a varying proton-electron mass ratio, μ. A high resolution spectrum of the J1443+2724 quasar, which was observed with the Very Large Telescope, is used to create an accurate model of 89 Lyman and Werner band transitions whose relative frequencies are sensitive to μ, yielding a limit on the relative deviation from the current laboratory value of Δμ/μ=(-9.5 ± 5.4(stat)± 5.3(syst))×10(-6).

  7. Taking out one billion tones of carbon: the magic of China's 11thFive-Year Plan

    SciTech Connect

    Lin, Jiang; Zhou, Nan; Levine, Mark D.; Fridley, David

    2007-05-01

    China's 11th Five-Year Plan (FYP) sets an ambitious targetfor energy-efficiency improvement: energy intensity of the country sgross domestic product (GDP) should be reduced by 20 percent from 2005 to2010 (NDRC, 2006). This is the first time that a quantitative and bindingtarget has been set for energy efficiency, and signals a major shift inChina's strategic thinking about its long-term economic and energydevelopment. The 20 percent energy intensity target also translates intoan annual reduction of over one billion tons of CO2 by 2010, making theChinese effort one of most significant carbon mitigation effort in theworld today. While it is still too early to tell whether China willachieve this target, this paper attempts to understand the trend inenergy intensity in China and to explore a variety of options towardmeeting the 20 percent target using a detailed endues energymodel.

  8. 1.8 Billion Years of Detrital Zircon Recycling Calibrates a Refractory Part of Earth’s Sedimentary Cycle

    PubMed Central

    Hadlari, Thomas; Swindles, Graeme T.; Galloway, Jennifer M.; Bell, Kimberley M.; Sulphur, Kyle C.; Heaman, Larry M.; Beranek, Luke P.; Fallas, Karen M.

    2015-01-01

    Detrital zircon studies are providing new insights on the evolution of sedimentary basins but the role of sedimentary recycling remains largely undefined. In a broad region of northwestern North America, this contribution traces the pathway of detrital zircon sand grains from Proterozoic sandstones through Phanerozoic strata and argues for multi-stage sedimentary recycling over more than a billion years. As a test of our hypothesis, integrated palynology and detrital zircon provenance provides clear evidence for erosion of Carboniferous strata in the northern Cordillera as a sediment source for Upper Cretaceous strata. Our results help to calibrate Earth's sedimentary cycle by showing that recycling dominates sedimentary provenance for the refractory mineral zircon. PMID:26658165

  9. Taking out 1 billion tons of CO2: The magic of China's 11th Five-Year Plan?

    SciTech Connect

    Zhou, Nan; Lin, Jiang; Zhou, Nan; Levine, Mark; Fridley, David

    2007-07-01

    China's 11th Five-Year Plan (FYP) sets an ambitious target for energy-efficiency improvement: energy intensity of the country's gross domestic product (GDP) should be reduced by 20% from 2005 to 2010 (NDRC, 2006). This is the first time that a quantitative and binding target has been set for energy efficiency, and signals a major shift in China's strategic thinking about its long-term economic and energy development. The 20% energy intensity target also translates into an annual reduction of over 1.5 billion tons of CO2 by 2010, making the Chinese effort one of most significant carbon mitigation effort in the world today. While it is still too early to tell whether China will achieve this target, this paper attempts to understand the trend in energy intensity in China and to explore a variety of options toward meeting the 20% target using a detailed end-use energy model.

  10. A large population of galaxies 9 to 12 billion years back in the history of the Universe

    NASA Astrophysics Data System (ADS)

    Le Fèvre, O.; Paltani, S.; Arnouts, S.; Charlot, S.; Foucaud, S.; Ilbert, O.; McCracken, H. J.; Zamorani, G.; Bottini, D.; Garilli, B.; Le Brun, V.; Maccagni, D.; Picat, J. P.; Scaramella, R.; Scodeggio, M.; Tresse, L.; Vettolani, G.; Zanichelli, A.; Adami, C.; Bardelli, S.; Bolzonella, M.; Cappi, A.; Ciliegi, P.; Contini, T.; Franzetti, P.; Gavignaud, I.; Guzzo, L.; Iovino, A.; Marano, B.; Marinoni, C.; Mazure, A.; Meneux, B.; Merighi, R.; Pellò, R.; Pollo, A.; Pozzetti, L.; Radovich, M.; Zucca, E.; Arnaboldi, M.; Bondi, M.; Bongiorno, A.; Busarello, G.; Gregorini, L.; Lamareille, F.; Mathez, G.; Mellier, Y.; Merluzzi, P.; Ripepi, V.; Rizzo, D.

    2005-09-01

    To understand the evolution of galaxies, we need to know as accurately as possible how many galaxies were present in the Universe at different epochs. Galaxies in the young Universe have hitherto mainly been identified using their expected optical colours, but this leaves open the possibility that a significant population remains undetected because their colours are the result of a complex mix of stars, gas, dust or active galactic nuclei. Here we report the results of a flux-limited I-band survey of galaxies at look-back times of 9 to 12 billion years. We find 970 galaxies with spectroscopic redshifts between 1.4 and 5. This population is 1.6 to 6.2 times larger than previous estimates, with the difference increasing towards brighter magnitudes. Strong ultraviolet continua (in the rest frame of the galaxies) indicate vigorous star formation rates of more than 10-100 solar masses per year. As a consequence, the cosmic star formation rate representing the volume-averaged production of stars is higher than previously measured at redshifts of 3 to 4.

  11. Decimetre-scale multicellular eukaryotes from the 1.56-billion-year-old Gaoyuzhuang Formation in North China

    PubMed Central

    Zhu, Shixing; Zhu, Maoyan; Knoll, Andrew H.; Yin, Zongjun; Zhao, Fangchen; Sun, Shufen; Qu, Yuangao; Shi, Min; Liu, Huan

    2016-01-01

    Fossils of macroscopic eukaryotes are rarely older than the Ediacaran Period (635–541 million years (Myr)), and their interpretation remains controversial. Here, we report the discovery of macroscopic fossils from the 1,560-Myr-old Gaoyuzhuang Formation, Yanshan area, North China, that exhibit both large size and regular morphology. Preserved as carbonaceous compressions, the Gaoyuzhuang fossils have statistically regular linear to lanceolate shapes up to 30 cm long and nearly 8 cm wide, suggesting that the Gaoyuzhuang fossils record benthic multicellular eukaryotes of unprecedentedly large size. Syngenetic fragments showing closely packed ∼10 μm cells arranged in a thick sheet further reinforce the interpretation. Comparisons with living thalloid organisms suggest that these organisms were photosynthetic, although their phylogenetic placement within the Eukarya remains uncertain. The new fossils provide the strongest evidence yet that multicellular eukaryotes with decimetric dimensions and a regular developmental program populated the marine biosphere at least a billion years before the Cambrian Explosion. PMID:27186667

  12. Decimetre-scale multicellular eukaryotes from the 1.56-billion-year-old Gaoyuzhuang Formation in North China.

    PubMed

    Zhu, Shixing; Zhu, Maoyan; Knoll, Andrew H; Yin, Zongjun; Zhao, Fangchen; Sun, Shufen; Qu, Yuangao; Shi, Min; Liu, Huan

    2016-05-17

    Fossils of macroscopic eukaryotes are rarely older than the Ediacaran Period (635-541 million years (Myr)), and their interpretation remains controversial. Here, we report the discovery of macroscopic fossils from the 1,560-Myr-old Gaoyuzhuang Formation, Yanshan area, North China, that exhibit both large size and regular morphology. Preserved as carbonaceous compressions, the Gaoyuzhuang fossils have statistically regular linear to lanceolate shapes up to 30 cm long and nearly 8 cm wide, suggesting that the Gaoyuzhuang fossils record benthic multicellular eukaryotes of unprecedentedly large size. Syngenetic fragments showing closely packed ∼10 μm cells arranged in a thick sheet further reinforce the interpretation. Comparisons with living thalloid organisms suggest that these organisms were photosynthetic, although their phylogenetic placement within the Eukarya remains uncertain. The new fossils provide the strongest evidence yet that multicellular eukaryotes with decimetric dimensions and a regular developmental program populated the marine biosphere at least a billion years before the Cambrian Explosion.

  13. A large population of galaxies 9 to 12 billion years back in the history of the Universe.

    PubMed

    Le Fèvre, O; Paltani, S; Arnouts, S; Charlot, S; Foucaud, S; Ilbert, O; McCracken, H J; Zamorani, G; Bottini, D; Garilli, B; Le Brun, V; Maccagni, D; Picat, J P; Scaramella, R; Scodeggio, M; Tresse, L; Vettolani, G; Zanichelli, A; Adami, C; Bardelli, S; Bolzonella, M; Cappi, A; Ciliegi, P; Contini, T; Franzetti, P; Gavignaud, I; Guzzo, L; Iovino, A; Marano, B; Marinoni, C; Mazure, A; Meneux, B; Merighi, R; Pellò, R; Pollo, A; Pozzetti, L; Radovich, M; Zucca, E; Arnaboldi, M; Bondi, M; Bongiorno, A; Busarello, G; Gregorini, L; Lamareille, F; Mathez, G; Mellier, Y; Merluzzi, P; Ripepi, V; Rizzo, D

    2005-09-22

    To understand the evolution of galaxies, we need to know as accurately as possible how many galaxies were present in the Universe at different epochs. Galaxies in the young Universe have hitherto mainly been identified using their expected optical colours, but this leaves open the possibility that a significant population remains undetected because their colours are the result of a complex mix of stars, gas, dust or active galactic nuclei. Here we report the results of a flux-limited I-band survey of galaxies at look-back times of 9 to 12 billion years. We find 970 galaxies with spectroscopic redshifts between 1.4 and 5. This population is 1.6 to 6.2 times larger than previous estimates, with the difference increasing towards brighter magnitudes. Strong ultraviolet continua (in the rest frame of the galaxies) indicate vigorous star formation rates of more than 10-100 solar masses per year. As a consequence, the cosmic star formation rate representing the volume-averaged production of stars is higher than previously measured at redshifts of 3 to 4.

  14. A One Billion Year Martian Climate Model: The Importance of Seasonally Resolved Polar Caps and the Role of Wind

    NASA Technical Reports Server (NTRS)

    Armstrong, J. C.; Leovy, C. B.; Quinn, T. R.; Haberle, R. M.; Schaeffer, J.

    2003-01-01

    Wind deflation and deposition are powerful agents of surface change in the present Mars climate regime. Recent studies indicate that, while the distribution of regions of potential deflation (or erosion) and deposition is remarkably insensitive to changes in orbital parameters (obliquity, timing of perihelion passage, etc.), rates of aeolian surface modification may be highly sensitive to these parameters even if the atmospheric mass remains constant. But previous work suggested the atmospheric mass is likely to be sensitive to obliquity, especially if a significant mass of carbon dioxide can be stored in the regolith or deposited in the form of massive polar caps. Deflation and erosion are highly sensitive to surface pressure, so feedback between orbit variations and surface pressure can greatly enhance the sensitivity of aeolian modification rates to orbital parameters. We used statistics derived from a 1 Gyr orbital integration of the spin axis of Mars, coupled with 3D general circulation models (GCMs) at a variety of orbital conditions and pressures, to explore this feedback. We also employed a seasonally resolved 1D energy balance model to illuminate the gross characteristics of the longterm atmospheric evolution, wind erosion and deposition over one billion years. We find that seasonal polar cycles have a critical influence on the ability for the regolith to release CO2 at high obliquities, and find that the atmospheric CO2 actually decreases at high obliquities due to the cooling effect of polar deposits at latitudes where seasonal caps form. At low obliquity, the formation of massive, permanent polar caps depends critically on the values of the frost albedo, A(sub frost), and frost emissivity, E(sub frost). Using our 1D model with values of A(sub frost) = 0.67 and E(sub frost) = 0.55, matched to the NASA Ames GCM results, we find that permanent caps only form at low obliquities (< 10 degrees). Thus, contrary to expectations, the Martian atmospheric pressure

  15. Organic-walled microfossils in 3.2-billion-year-old shallow-marine siliciclastic deposits.

    PubMed

    Javaux, Emmanuelle J; Marshall, Craig P; Bekker, Andrey

    2010-02-18

    Although the notion of an early origin and diversification of life on Earth during the Archaean eon has received increasing support in geochemical, sedimentological and palaeontological evidence, ambiguities and controversies persist regarding the biogenicity and syngeneity of the record older than Late Archaean. Non-biological processes are known to produce morphologies similar to some microfossils, and hydrothermal fluids have the potential to produce abiotic organic compounds with depleted carbon isotope values, making it difficult to establish unambiguous traces of life. Here we report the discovery of a population of large (up to about 300 mum in diameter) carbonaceous spheroidal microstructures in Mesoarchaean shales and siltstones of the Moodies Group, South Africa, the Earth's oldest siliciclastic alluvial to tidal-estuarine deposits. These microstructures are interpreted as organic-walled microfossils on the basis of petrographic and geochemical evidence for their endogenicity and syngeneity, their carbonaceous composition, cellular morphology and ultrastructure, occurrence in populations, taphonomic features of soft wall deformation, and the geological context plausible for life, as well as a lack of abiotic explanation falsifying a biological origin. These are the oldest and largest Archaean organic-walled spheroidal microfossils reported so far. Our observations suggest that relatively large microorganisms cohabited with earlier reported benthic microbial mats in the photic zone of marginal marine siliciclastic environments 3.2 billion years ago.

  16. Sulfur isotopes of organic matter preserved in 3.45-billion-year-old stromatolites reveal microbial metabolism.

    PubMed

    Bontognali, Tomaso R R; Sessions, Alex L; Allwood, Abigail C; Fischer, Woodward W; Grotzinger, John P; Summons, Roger E; Eiler, John M

    2012-09-18

    The 3.45-billion-year-old Strelley Pool Formation of Western Australia preserves stromatolites that are considered among the oldest evidence for life on Earth. In places of exceptional preservation, these stromatolites contain laminae rich in organic carbon, interpreted as the fossil remains of ancient microbial mats. To better understand the biogeochemistry of these rocks, we performed microscale in situ sulfur isotope measurements of the preserved organic sulfur, including both Δ(33)S and . This approach allows us to tie physiological inference from isotope ratios directly to fossil biomass, providing a means to understand sulfur metabolism that is complimentary to, and independent from, inorganic proxies (e.g., pyrite). Δ(33)S values of the kerogen reveal mass-anomalous fractionations expected of the Archean sulfur cycle, whereas values show large fractionations at very small spatial scales, including values below -15‰. We interpret these isotopic patterns as recording the process of sulfurization of organic matter by H(2)S in heterogeneous mat pore-waters influenced by respiratory S metabolism. Positive Δ(33)S anomalies suggest that disproportionation of elemental sulfur would have been a prominent microbial process in these communities.

  17. Mobile hydrocarbon microspheres from >2-billion-year-old carbon-bearing seams in the South African deep subsurface.

    PubMed

    Wanger, G; Moser, D; Hay, M; Myneni, S; Onstott, T C; Southam, G

    2012-11-01

    By ~2.9 Ga, the time of the deposition of the Witwatersrand Supergroup, life is believed to have been well established on Earth. Carbon remnants of the microbial biosphere from this time period are evident in sediments from around the world. In the Witwatersrand Supergroup, the carbonaceous material is often concentrated in seams, closely associated with the gold deposits and may have been a mobile phase 2 billion years ago. Whereas today the carbon in the Witwatersrand Supergroup is presumed to be immobile, hollow hydrocarbon spheres ranging in size from <1 μm to >50 μm were discovered emanating from a borehole drilled through the carbon-bearing seams suggesting that a portion of the carbon may still be mobile in the deep subsurface. ToF-SIMS and STXM analyses revealed that these spheres contain a suite of alkane, alkenes, and aromatic compounds consistent with the described organic-rich carbon seams within the Witwatersrand Supergroup's auriferous reef horizons. Analysis by electron microscopy and ToF-SIMS, however, revealed that these spheres, although most likely composed of biogenic carbon and resembling biological organisms, do not retain any true structural, that is, fossil, information and were formed by an abiogenic process.

  18. Sulfur isotopes of organic matter preserved in 3.45-billion-year-old stromatolites reveal microbial metabolism

    PubMed Central

    Bontognali, Tomaso R. R.; Sessions, Alex L.; Allwood, Abigail C.; Fischer, Woodward W.; Grotzinger, John P.; Summons, Roger E.; Eiler, John M.

    2012-01-01

    The 3.45-billion-year-old Strelley Pool Formation of Western Australia preserves stromatolites that are considered among the oldest evidence for life on Earth. In places of exceptional preservation, these stromatolites contain laminae rich in organic carbon, interpreted as the fossil remains of ancient microbial mats. To better understand the biogeochemistry of these rocks, we performed microscale in situ sulfur isotope measurements of the preserved organic sulfur, including both Δ33S and . This approach allows us to tie physiological inference from isotope ratios directly to fossil biomass, providing a means to understand sulfur metabolism that is complimentary to, and independent from, inorganic proxies (e.g., pyrite). Δ33S values of the kerogen reveal mass-anomalous fractionations expected of the Archean sulfur cycle, whereas values show large fractionations at very small spatial scales, including values below -15‰. We interpret these isotopic patterns as recording the process of sulfurization of organic matter by H2S in heterogeneous mat pore-waters influenced by respiratory S metabolism. Positive Δ33S anomalies suggest that disproportionation of elemental sulfur would have been a prominent microbial process in these communities. PMID:22949693

  19. Evidence from massive siderite beds for a CO2-rich atmosphere before approximately 1.8 billion years ago

    NASA Technical Reports Server (NTRS)

    Ohmoto, Hiroshi; Watanabe, Yumiko; Kumazawa, Kazumasa

    2004-01-01

    It is generally thought that, in order to compensate for lower solar flux and maintain liquid oceans on the early Earth, methane must have been an important greenhouse gas before approximately 2.2 billion years (Gyr) ago. This is based upon a simple thermodynamic calculation that relates the absence of siderite (FeCO3) in some pre-2.2-Gyr palaeosols to atmospheric CO2 concentrations that would have been too low to have provided the necessary greenhouse effect. Using multi-dimensional thermodynamic analyses and geological evidence, we show here that the absence of siderite in palaeosols does not constrain atmospheric CO2 concentrations. Siderite is absent in many palaeosols (both pre- and post-2.2-Gyr in age) because the O2 concentrations and pH conditions in well-aerated soils have favoured the formation of ferric (Fe3+)-rich minerals, such as goethite, rather than siderite. Siderite, however, has formed throughout geological history in subsurface environments, such as euxinic seas, where anaerobic organisms created H2-rich conditions. The abundance of large, massive siderite-rich beds in pre-1.8-Gyr sedimentary sequences and their carbon isotope ratios indicate that the atmospheric CO2 concentration was more than 100 times greater than today, causing the rain and ocean waters to be more acidic than today. We therefore conclude that CO2 alone (without a significant contribution from methane) could have provided the necessary greenhouse effect to maintain liquid oceans on the early Earth.

  20. Dipolar geomagnetic field and low orbital obliquity during the last two billion years: Evidence from paleomagnetism of evaporite basins

    NASA Astrophysics Data System (ADS)

    Evans, D. A.

    2006-05-01

    Paleomagnetism of climatically sensitive sedimentary rock types, such as glacial deposits and evaporites, can test the uniformitarianism of ancient geomagnetic fields and paleoclimatic zones. Precambrian glacial deposits laid down in near-equatorial paleomagnetic latitudes indicate a paleoclimatic paradox that can be explained either by Snowball Earth episodes, or high orbital obliquity, or dramatically non-uniformitarian geomagnetic fields. Here I present the first global paleomagnetic compilation of the Earth's entire basin-scale evaporite record. Evaporation exceeds precipitation in today's subtropical desert belts, generally within a zone of 15-35° from the equator. Assuming a geocentric axial dipole (GAD) magnetic field for Cenozoic- Mesozoic time, evaporite basins of the past 250 Myr have a volume-weighted mean paleolatitude of 23±4°, also squarely within the subtropics. Carboniferous-Permian evaporites have an indistinguishable weighted-mean paleolatitude of 22±4°, which does not change significantly when recently hypothesized octupolar field components are included in the calculations. Early Paleozoic (including late Ediacaran) evaporites are lower-latitude (weighted mean 10±5°), but detailed analyses of individual examples show this cannot be attributed solely to nondipolar field components or sedimentary inclination biases; the cause may be due to particular paleogeographic effects on regional tropical climates, or incomplete sampling by the paleomagnetic data. Proterozoic (pre-Ediacaran) evaporite basins have a volume- weighted mean inclination of 33±4°, which would correspond to a mean paleolatitude of 18±3° for a pure GAD field. This latter mean is indistinguishable, within error, from the Cenozoic-Mesozoic mean and demonstrates the success of the GAD model as a first-order description of the geomagnetic field for the last two billion years. Also, general circulation climate models of a high-obliquity Earth predict either no strong zonal

  1. a Billion Years of Steady-State Crustal Growth; the 1.9-0.9 GA Evolution of SW Fennoscandia

    NASA Astrophysics Data System (ADS)

    Slagstad, T.; Roberts, N. M.; Andersen, T.; Sauer, S.; Røhr, T. S.

    2012-12-01

    continent-continent collision, but has more recently been placed in the context of orogenesis within an accretionary orogen. Either way, the 1.02-0.98 Ga period was an extensive compressional phase that saw the final accretion and stabilization of all existing fragments of this margin. An extensional phase resumed after 0.96 Ga, and subduction either ceased altogether or jumped outboard again. This billion year period features steady-state crustal growth for much of it. Variations in trench-continent movement (tectonic switching) produce periods of more crustal reworking alternating with periods of greater juvenile addition; alternating compressional and extensional environments stabilize as well as produce arc-derived continental crust. The preserved record, however, is not representative of the crust produced; whereas the dominantly extensional period has produced a large expanse of crust that is partially preserved, a dominantly compressional environment removed crust to the mantle. Although a full continent-continent collision may not have occurred, the regional geodynamics, possibly related to Rodinia formation, have biased the preserved record of crustal growth. Our model supports the concept of steady-state crustal growth, and preservation bias that leaves an episodic record.

  2. Lamellar magnetism and exchange bias in billion-year-old titanohematite with nanoscale ilmenite exsolution lamellae: I. Mineral and magnetic characterization

    NASA Astrophysics Data System (ADS)

    McEnroe, Suzanne A.; Robinson, Peter; Miyajima, Nobuyoshi; Fabian, Karl; Dyar, Darby; Sklute, Elizabeth

    2016-07-01

    Recent high-resolution aeromagnetic surveys in South Norway have revealed numerous remanent anomalies over Mesoproterozoic metamorphic rocks. Studies on the nature of the minerals that are the remanent carriers has led to discoveries of titanohematite samples with unusual magnetic properties caused by nanoscale exsolution lamellae with their related lamellar magnetism. Here we focus on a rock unit dominated by quartz-plagioclase-biotite granulite containing titanohematite grains with a strong lattice-preferred orientation parallel to regional foliation. When samples with their natural remanent magnetization (NRM), acquired nearly 1 billion years ago, are cooled to 10 K and hysteresis loops measured, these loops show bi-modal exchange bias caused by the magnetism induced within the ilmenite by antiferromagnetic coupling with the adjacent lamellar NRM. By contrast when the samples are cooled in a strong magnetic field (1.5 Tesla), this results in unimodal lamellar magnetism, and, below the TN of ilmenite it adopts a consistent negative orientation, giving rise to unimodal negative exchange bias of >500 mT. The results presented here cover the chemical and magnetic properties, Mossbauer results and transmission electron microscopy of the titanohematite and ilmenite lamellae. Initial magnetic experiments indicated the shifts found in the exchange-bias experiments were directly related to the orientation of the sample to the applied field and the initial state of the NRM. In most samples with these unusual magnetic properties, ilmenite lamellae could not be seen in an optical or a scanning electron microscope. However magnetic experiments gave proof of the presence of ilmenite, later confirmed by Mössbauer spectroscopy. Several attempts were made to identify ilmenite in TEM studies, finally successful in showing ilmenite lamellae parallel to (001) of hematite with thicknesses ˜1.2 to 1.7 nm and aspect ratios 7-13. Here we compare new TEM images and the magnetic

  3. Exceptional preservation of aragonite in a circa 3.3 billion year old microbial mat from the Barberton greenstone belt, South Africa

    NASA Astrophysics Data System (ADS)

    Westall, Frances; Cavalazzi, Barbara; Lemelle, Laurence; Marrochhi, Yves; Rouzaud, Jean-Noel; Simionovici, Alexandre; Andreazza, Caroline; Foucher, Frédéric; Thiel, Volker; Hofmann, Axel

    2010-05-01

    Exceptional preservation of aragonite in a circa 3.3 billion year old microbial mat from the Barberton greenstone belt, South Africa Frances Westall, Barbara Cavalazzi, Laurence Lemelle, Yves Marrocchi, Jean-Noël Rouzaud, Alexandre Simionovici, Murielle Salomé, Smail Mostefaoui, Caroline Andreazza, Frédéric Foucher, Jan Toporski, Andrea Jauss, Volker Thiel, Axel Hofmann, Anders Meibom, François Robert Aragonite occurs as a biologically-formed mineral precipitate within modern calcifying microbial mats. It is, however, rarely preserved in the geological record because, as one of the least stable polymorphs of calcium carbonate, it readily converts to calcite in present environmental conditions at the Earth's surface. In an in situ investigation at the micro- to nanometer-scale, we show that 5-10 nm sized nanocrystals of aragonite are preserved within the organic framework of a partially calcified microbial mat from the ~ 3.3 billion year-old Josefsdal Chert in the Barberton greenstone belt, South Africa. Transformation of the aragonite to calcite was blocked by a combination of chemical inhibitors within the crystal lattice, organic molecules coating the nanocrystals and, in particular, to the precocious permeation of the mat by hydrothermal silica. Apart from its exceptional preservation for 3.3 billion years, the identification of aragonite in the Josefsdal microbial mat is the earliest evidence for in situ calcification of a microbial mat. Furthermore, the indications of associated sulphur-reducing bacteria (SRB) activity with calcification strongly support a photosynthetic origin for the mat. This is the most direct evidence for photosynthesis in early Archaean rocks.

  4. Recrystallized Granite Surface Fissures Of The Wasatch Range, Produced Not Later Than 1/4 Billion Years Ago

    NASA Astrophysics Data System (ADS)

    McDonald, Keith L.

    2000-05-01

    Our studies of numerous recrystallized fissures in 4 granite plutons of Wasatch Range, namely, Mount Tuscarora-Wolverine-Millicent,^1,6,7 Bonanza Peak-Midway,^2 Little Cottonwood Canyon and Ferguson Canyon plutons, all of which formed magma chambers reaching Earth-atmosphere interface, establish that they resulted from high thermal gradients rather than passages of earthquake waves. Magma chambers formed, solidified during Permo-Caroniferous Ice Age(roughly, 1/3...1/4 billion yr ago, a time interval preceding period of extrusion of Rocky Mountains, 10^8 yr ago), and while fluid, belched lava flows^5 extending over its reservoir walls to run hundred of meters. We have shown how the magma melts, dilutes and replaces overlying metamorphic rock^7 to reach Earth's surface so that a pluton containing large amounts of dross(Fe-ores, etc.) had a short fluid lifetime. We also described how offshoots from a long-running main fissure form acute angles with that fissure.^3 Such recrystallized fissures, reaching depths of perhaps 100 m, have initial fractures near time of solidification of their uppermost portion of magma chamber while still hot(<= 1600^oF), a time when max. stresses occur near granite surface due to high thermal gradients, owing to snow coverage, cold water contacts due to rain, stream flow over granite surface, partial coverage by ocean, etc., wherever heat sinks might occur, during P-C ice age--when region of Wasatch Range existed at sea level, Salt Lake Valley being covered entirely by ocean water and region east of Wasatch Bouleuard rising gently above Pacific Ocean to elevations of possibly 500-1000 ft, say, at a distance of 10-15 mi to east. This fact is implied by Chinese Wall of white limestone on Grandeur Peak, unequivocally, and similarly another in Neff's Canyon running e. from n. ridge of 9200 ft. saddle-summit, as well as a dozen other ancient calcified stream beds emptying into ocean to w., in Salt Lake Valley. This existed prior to regional

  5. Microbially Induced Sedimentary Structures Recording an Ancient Ecosystem in the ca. 3.48 Billion-Year-Old Dresser Formation, Pilbara, Western Australia

    PubMed Central

    Christian, Daniel; Wacey, David; Hazen, Robert M.

    2013-01-01

    Abstract Microbially induced sedimentary structures (MISS) result from the response of microbial mats to physical sediment dynamics. MISS are cosmopolitan and found in many modern environments, including shelves, tidal flats, lagoons, riverine shores, lakes, interdune areas, and sabkhas. The structures record highly diverse communities of microbial mats and have been reported from numerous intervals in the geological record up to 3.2 billion years (Ga) old. This contribution describes a suite of MISS from some of the oldest well-preserved sedimentary rocks in the geological record, the early Archean (ca. 3.48 Ga) Dresser Formation, Western Australia. Outcrop mapping at the meter to millimeter scale defined five sub-environments characteristic of an ancient coastal sabkha. These sub-environments contain associations of distinct macroscopic and microscopic MISS. Macroscopic MISS include polygonal oscillation cracks and gas domes, erosional remnants and pockets, and mat chips. Microscopic MISS comprise tufts, sinoidal structures, and laminae fabrics; the microscopic laminae are composed of primary carbonaceous matter, pyrite, and hematite, plus trapped and bound grains. Identical suites of MISS occur in equivalent environmental settings through the entire subsequent history of Earth including the present time. This work extends the geological record of MISS by almost 300 million years. Complex mat-forming microbial communities likely existed almost 3.5 billion years ago. Key Words: Archean—Biofilms—Microbial mats—Early Earth—Evolution. Astrobiology 13, 1103–1124. PMID:24205812

  6. Microbially induced sedimentary structures recording an ancient ecosystem in the ca. 3.48 billion-year-old Dresser Formation, Pilbara, Western Australia.

    PubMed

    Noffke, Nora; Christian, Daniel; Wacey, David; Hazen, Robert M

    2013-12-01

    Microbially induced sedimentary structures (MISS) result from the response of microbial mats to physical sediment dynamics. MISS are cosmopolitan and found in many modern environments, including shelves, tidal flats, lagoons, riverine shores, lakes, interdune areas, and sabkhas. The structures record highly diverse communities of microbial mats and have been reported from numerous intervals in the geological record up to 3.2 billion years (Ga) old. This contribution describes a suite of MISS from some of the oldest well-preserved sedimentary rocks in the geological record, the early Archean (ca. 3.48 Ga) Dresser Formation, Western Australia. Outcrop mapping at the meter to millimeter scale defined five sub-environments characteristic of an ancient coastal sabkha. These sub-environments contain associations of distinct macroscopic and microscopic MISS. Macroscopic MISS include polygonal oscillation cracks and gas domes, erosional remnants and pockets, and mat chips. Microscopic MISS comprise tufts, sinoidal structures, and laminae fabrics; the microscopic laminae are composed of primary carbonaceous matter, pyrite, and hematite, plus trapped and bound grains. Identical suites of MISS occur in equivalent environmental settings through the entire subsequent history of Earth including the present time. This work extends the geological record of MISS by almost 300 million years. Complex mat-forming microbial communities likely existed almost 3.5 billion years ago.

  7. State Funds for Higher Education Total $34-Billion; 11-Pct. Biennial Rise Equals Lowest in 29 Years.

    ERIC Educational Resources Information Center

    Jaschik, Scott

    1987-01-01

    Tight state budgets and regional economic difficulties have prompted a sharp drop in the rate that state appropriations for higher education have increased over the past two years. New England fares well while farm and oil states suffer. (MLW)

  8. The Evolution of the Galaxy Rest-Frame Ultraviolet Luminosity Function Over the First Two Billion Years

    NASA Technical Reports Server (NTRS)

    Finkelstein, Steven L.; Ryan, Russell E., Jr.; Papovich, Casey; Dickinson, Mark; Song, Mimi; Somerville, Rachel; Ferguson, Henry C.; Salmon, Brett; Giavalisco, Mauro; Koekomoer, Anton M.; Ashby, Matthew L. N.; Behroozi, Peter; Castellano, Marco; Dunlop, James S.; Faber, Sandy M.; Fazio, Giovanni G.; Fontana, Adriano; Grogin, Norman A.; Hathi, Nimish; Jaacks, Jason; Kocevski, Dale D.; Livermore, Rachael; McLure, Ross J.; Merlin, Emiliano; Rafelski, Marc Alexander

    2014-01-01

    We present a robust measurement and analysis of the rest-frame ultraviolet (UV) luminosity function at z = 4 to 8. We use deep Hubble Space Telescope imaging over the CANDELS/GOODS fields, the Hubble Ultra Deep Field and the Hubble Frontier Field deep parallel observations near the Abell 2744 and MACS J0416.1- 2403 clusters. The combination of these surveys provides an effective volume of 0.6-1.2 ×10(exp 6) Mpc(exp 3) over this epoch, allowing us to perform a robust search for bright (M(sub UV) less than -21) and faint (M(sub UV) = -18) galaxies. We select galaxies using a well-tested photometric redshift technique with careful screening of contaminants, finding a sample of 7446 galaxies at 3.5 less than z less than 8.5, with more than 1000 galaxies at z of approximately 6 - 8. We measure both a stepwise luminosity function for galaxies in our redshift samples, as well as a Schechter function, using a Markov Chain Monte Carlo analysis to measure robust uncertainties. At the faint end our UV luminosity functions agree with previous studies, yet we find a higher abundance of UV-bright galaxies at z of greater than or equal to 6. Our bestfit value of the characteristic magnitude M* is consistent with -21 at z of greater than or equal to 5, different than that inferred based on previous trends at lower redshift. At z = 8, a single power-law provides an equally good fit to the UV luminosity function, while at z = 6 and 7, an exponential cutoff at the bright-end is moderately preferred. We compare our luminosity functions to semi-analytical models, and find that the lack of evolution in M* is consistent with models where the impact of dust attenuation on the bright-end of the luminosity function decreases at higher redshift, though a decreasing impact of feedback may also be possible. We measure the evolution of the cosmic star-formation rate (SFR) density by integrating our observed luminosity functions to M(sub UV) = -17, correcting for dust attenuation, and find that

  9. The Evolution of the Galaxy Rest-frame Ultraviolet Luminosity Function over the First Two Billion Years

    NASA Astrophysics Data System (ADS)

    Finkelstein, Steven L.; Ryan, Russell E., Jr.; Papovich, Casey; Dickinson, Mark; Song, Mimi; Somerville, Rachel S.; Ferguson, Henry C.; Salmon, Brett; Giavalisco, Mauro; Koekemoer, Anton M.; Ashby, Matthew L. N.; Behroozi, Peter; Castellano, Marco; Dunlop, James S.; Faber, Sandy M.; Fazio, Giovanni G.; Fontana, Adriano; Grogin, Norman A.; Hathi, Nimish; Jaacks, Jason; Kocevski, Dale D.; Livermore, Rachael; McLure, Ross J.; Merlin, Emiliano; Mobasher, Bahram; Newman, Jeffrey A.; Rafelski, Marc; Tilvi, Vithal; Willner, S. P.

    2015-09-01

    We present a robust measurement and analysis of the rest-frame ultraviolet (UV) luminosity functions at z = 4-8. We use deep Hubble Space Telescope imaging over the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey/GOODS fields, the Hubble Ultra Deep Field, and the Hubble Frontier Field deep parallel observations near the Abell 2744 and MACS J0416.1-2403 clusters. The combination of these surveys provides an effective volume of 0.6-1.2 × 106 Mpc3 over this epoch, allowing us to perform a robust search for faint ({M}{UV}=-18) and bright (M{}{UV}\\lt -21) high-redshift galaxies. We select candidate galaxies using a well-tested photometric redshift technique with careful screening of contaminants, finding a sample of 7446 candidate galaxies at 3.5 \\lt z \\lt 8.5, with >1000 galaxies at z ≈ 6-8. We measure both a stepwise luminosity function for candidate galaxies in our redshift samples, and a Schechter function, using a Markov Chain Monte Carlo analysis to measure robust uncertainties. At the faint end, our UV luminosity functions agree with previous studies, yet we find a higher abundance of UV-bright candidate galaxies at z ≥slant 6. Our best-fit value of the characteristic magnitude {M}{UV}* is consistent with -21 at z ≥slant 5, which is different than that inferred based on previous trends at lower redshift, and brighter at ˜2σ significance than previous measures at z = 6 and 7. At z = 8, a single power law provides an equally good fit to the UV luminosity function, while at z = 6 and 7 an exponential cutoff at the bright end is moderately preferred. We compare our luminosity functions to semi-analytical models, and find that the lack of evolution in {M}{UV}* is consistent with models where the impact of dust attenuation on the bright end of the luminosity function decreases at higher redshift, although a decreasing impact of feedback may also be possible. We measure the evolution of the cosmic star-formation rate (SFR) density by

  10. 5.5 billion -- and growing.

    PubMed

    Robey, B

    1992-07-17

    On World Population Day in 1992 the total world population reached 5.5 billion, 100 million more than on July 11, 1991, and it is expected to pass the 6 billion figure by 2000. In developed countries the average number of children is 2/family, while in developing countries the norm is 4 children, a substantial drop from 6 children in the 1960s. The 2 billion level was reached in 1930, the world population doubled from 1 billion in 100 years. The billion mark in 1960 took only 30 years, the 4 billion figure was reached in 1975 in only 15 years, and to grow to 5 billion in 1987 took only 12 years. A 20-year delay to reach replacement level adds another 1 billion to the population size. If the 2-children-per family size had been reached in 1990, the total would still have increased to 8 billion by 2100. Provided the present trend of 3.4 children/couple continues, there will be 102 billion people in 2100. Some claim that the resources of the Earth are already overtaxed with ever-worsening environmental pollution. Family planning information and services have to me made available to those millions who want to avoid pregnancy and ensure a better future for fewer children.

  11. Spend Billions and They Will Come

    ERIC Educational Resources Information Center

    Fox, Bette-Lee

    2004-01-01

    People look at one billion dollars in one of two ways: if it is the result of the long, hard effort of years of fundraising, they rejoice; if it signifies an astronomical budget deficit, they cringe. How, then, should people respond as a community to reaching the $1 billion mark ($1,242,436,438, to be exact) in this year's spending for public…

  12. Developmental Norms of Children Aged 2 1/2-5 Years: A Pilot Study.

    ERIC Educational Resources Information Center

    Muralidharan, Rajalakshmi

    1969-01-01

    The purpose of this pilot study, aside from collection of developmental data on 38 nursery school children aged 2 1/2 to 5 years, was (1) to develop, modify and adapt the testing equipment used in Gesell's Developmental Schedule, in the field of motor, adaptive, language, and personal-social development; (2) to develop elaborate, exhaustive,…

  13. Common Aetiology for Diverse Language Skills in 4 1/2-Year-Old Twins

    ERIC Educational Resources Information Center

    Hayiou-Thomas, Marianna E.; Kovas, Yulia; Harlaar, Nicole; Plomin, Robert; Bishop, Dorothy V. M.; Dale, Philip S.

    2006-01-01

    Multivariate genetic analysis was used to examine the genetic and environmental aetiology of the interrelationships of diverse linguistic skills. This study used data from a large sample of 4 1/2-year-old twins who were tested on measures assessing articulation, phonology, grammar, vocabulary, and verbal memory. Phenotypic analysis suggested two…

  14. Two-phase increase in the maximum size of life over 3.5 billion years reflects biological innovation and environmental opportunity

    PubMed Central

    Payne, Jonathan L.; Boyer, Alison G.; Brown, James H.; Finnegan, Seth; Kowalewski, Michał; Krause, Richard A.; Lyons, S. Kathleen; McClain, Craig R.; McShea, Daniel W.; Novack-Gottshall, Philip M.; Smith, Felisa A.; Stempien, Jennifer A.; Wang, Steve C.

    2009-01-01

    The maximum size of organisms has increased enormously since the initial appearance of life >3.5 billion years ago (Gya), but the pattern and timing of this size increase is poorly known. Consequently, controls underlying the size spectrum of the global biota have been difficult to evaluate. Our period-level compilation of the largest known fossil organisms demonstrates that maximum size increased by 16 orders of magnitude since life first appeared in the fossil record. The great majority of the increase is accounted for by 2 discrete steps of approximately equal magnitude: the first in the middle of the Paleoproterozoic Era (≈1.9 Gya) and the second during the late Neoproterozoic and early Paleozoic eras (0.6–0.45 Gya). Each size step required a major innovation in organismal complexity—first the eukaryotic cell and later eukaryotic multicellularity. These size steps coincide with, or slightly postdate, increases in the concentration of atmospheric oxygen, suggesting latent evolutionary potential was realized soon after environmental limitations were removed. PMID:19106296

  15. From the Cover: Sulfur isotopes of organic matter preserved in 3.45-billion-year-old stromatolites reveal microbial metabolism

    NASA Astrophysics Data System (ADS)

    Bontognali, Tomaso R. R.; Sessions, Alex L.; Allwood, Abigail C.; Fischer, Woodward W.; Grotzinger, John P.; Summons, Roger E.; Eiler, John M.

    2012-09-01

    The 3.45-billion-year-old Strelley Pool Formation of Western Australia preserves stromatolites that are considered among the oldest evidence for life on Earth. In places of exceptional preservation, these stromatolites contain laminae rich in organic carbon, interpreted as the fossil remains of ancient microbial mats. To better understand the biogeochemistry of these rocks, we performed microscale in situ sulfur isotope measurements of the preserved organic sulfur, including both Δ33S and . This approach allows us to tie physiological inference from isotope ratios directly to fossil biomass, providing a means to understand sulfur metabolism that is complimentary to, and independent from, inorganic proxies (e.g., pyrite). Δ33S values of the kerogen reveal mass-anomalous fractionations expected of the Archean sulfur cycle, whereas values show large fractionations at very small spatial scales, including values below -15‰. We interpret these isotopic patterns as recording the process of sulfurization of organic matter by H2S in heterogeneous mat pore-waters influenced by respiratory S metabolism. Positive Δ33S anomalies suggest that disproportionation of elemental sulfur would have been a prominent microbial process in these communities.

  16. Nine billion or bust?

    NASA Astrophysics Data System (ADS)

    nerd, nerd; Pepperday, Mike; Szautner, a. a. z.

    2014-02-01

    In reply to a review of Tony Ryan and Steve McKevitt's book Project Sunshine, which explores ways in which the Earth could support a future population of nine billion people (Letting the sunshine in, November 2013 pp50-51, http://ow.ly/r0FTM).

  17. The OAO heat pipes - 8 1/2 years of flight data

    NASA Technical Reports Server (NTRS)

    Harwell, W.; Mcintosh, R.

    1981-01-01

    Heat pipe performance data taken during the 8 1/2 years of flight of the OAO-C (Copernicus) spacecraft are presented. Three fixed conductance heat pipes (FCHP), each with different wicking concepts (axial groove, pedestal artery, and self-priming spiral artery), and one variable conductance heat pipe (VCHP) are onboard. Aluminum tubes (1/2 in. diameter) rolled into a 48 in. loop containing ultra high purity ammonia as the heat transfer fluid comprise all FCHP, whose purpose is to circumferentially isothermalize the central tube housing the telescope. The VCHP is a hot, non-wicked reservoir concept including a composite artery and methanol heat transfer fluid, and is used to maintain the temperature of the onboard processor. Flight thermal data analysis reveals that no degradation in performance occurred since launch and agrees well with pre-flight data; the onboard processor still shows an offset in control range of 4 F, and the pipes perform the same after 8 1/2 years in orbit.

  18. Stable Isotope Geochemistry of Extremely Well-Preserved 2.45-Billion-Year-Old Hydrothermal Systems in the Vetreny Belt, Baltic Shield: Insights into Paleohydrosphere

    NASA Astrophysics Data System (ADS)

    Zakharov, D. O.; Bindeman, I. N.

    2015-12-01

    The early Paleoproterozoic was an eventful period in the Earth's history. The first portions of free oxygen emerged in the atmosphere, Snowball Earth glaciations happened several times and the first supercontinent broke up due to extensive rifting. These events should have affected the stable isotopic composition of the hydrosphere. In this study, we use rocks that were altered in underwater hydrothermal systems to investigate the stable isotopic composition of the hydrosphere 2.39-2.45 billion years ago (hereinafter, Ga). Extremely low-δ18O (down to -27.5‰ SMOW) rocks from 2.39 Ga metamorphosed subglacial hydrothermal systems of the Belomorian belt, Baltic Shield formed at near-equatorial latitudes suggesting a Snowball (or Slushball) Earth glaciation. These results motivated us to look at temporally and geographically close hydrothermal systems from the unmetamorhposed 2.45 Ga Vetreny Belt rift. The length of the rift is 250 km and it is composed of high-Mg basalts, mafic-ultramafic intrusions and sedimentary successions. We examined several localities of high-Mg basalt flows that include astonishingly fresh pillow lavas, often with preserved volcanic glass, eruptive breccias, and hydrothermal alteration zones. Collected samples serve a great textural evidence of water-rock interaction that occurred in situ while basalts were cooling. The preliminary results from coexisting quartz and epidote (T, D18O=311°C), and from coexisting calcite and quartz (T, D18O=190°C) yield values of δ18O of involved water between -1.6 and -0.9 ‰. The values of δ13C in calcites vary between -4.0 and -2.3 ‰. It is likely that hydrothermal fluids operated in the Vetreny Belt rift were derived from seawater that is no different from modern oceanic water in terms of δ18O. Apparently, the rift was a Paleoproterozoic analog of the modern Red Sea, filled with oceanic water. The result is important because the Vetreny Belt rift predates the onset of Snowball Earth glaciation at 2

  19. Composition and syngeneity of molecular fossils from the 2.78 to 2.45 billion-year-old Mount Bruce Supergroup, Pilbara Craton, Western Australia

    NASA Astrophysics Data System (ADS)

    Brocks, Jochen J.; Buick, Roger; Logan, Graham A.; Summons, Roger E.

    2003-11-01

    Shales of very low metamorphic grade from the 2.78 to 2.45 billion-year-old (Ga) Mount Bruce Supergroup, Pilbara Craton, Western Australia, were analyzed for solvent extractable hydrocarbons. Samples were collected from ten drill cores and two mines in a sampling area centered in the Hamersley Basin near Wittenoom and ranging 200 km to the southeast, 100 km to the southwest and 70 km to the northwest. Almost all analyzed kerogenous sedimentary rocks yielded solvent extractable organic matter. Concentrations of total saturated hydrocarbons were commonly in the range of 1 to 20 ppm (μg/g rock) but reached maximum values of 1000 ppm. The abundance of aromatic hydrocarbons was ˜1 to 30 ppm. Analysis of the extracts by gas chromatography-mass spectrometry (GC-MS) and GC-MS metastable reaction monitoring (MRM) revealed the presence of n-alkanes, mid- and end-branched monomethylalkanes, ω-cyclohexylalkanes, acyclic isoprenoids, diamondoids, tri- to pentacyclic terpanes, steranes, aromatic steroids and polyaromatic hydrocarbons. Neither plant biomarkers nor hydrocarbon distributions indicative of Phanerozoic contamination were detected. The host kerogens of the hydrocarbons were depleted in 13C by 2 to 21‰ relative to n-alkanes, a pattern typical of, although more extreme than, other Precambrian samples. Acyclic isoprenoids showed carbon isotopic depletion relative to n-alkanes and concentrations of 2α-methylhopanes were relatively high, features rarely observed in the Phanerozoic but characteristic of many other Precambrian bitumens. Molecular parameters, including sterane and hopane ratios at their apparent thermal maxima, condensate-like alkane profiles, high mono- and triaromatic steroid maturity parameters, high methyladamantane and methyldiamantane indices and high methylphenanthrene maturity ratios, indicate thermal maturities in the wet-gas generation zone. Additionally, extracts from shales associated with iron ore deposits at Tom Price and Newman have

  20. Interaction, at Ambient Temperature and 80 °C, between Minerals and Artificial Seawaters Resembling the Present Ocean Composition and that of 4.0 Billion Years Ago

    NASA Astrophysics Data System (ADS)

    Carneiro, Cristine E. A.; Stabile, Antonio C.; Gomes, Frederico P.; da Costa, Antonio C. S.; Zaia, Cássia T. B. V.; Zaia, Dimas A. M.

    2016-10-01

    Probably one of the most important roles played by minerals in the origin of life on Earth was to pre-concentrate biomolecules from the prebiotic seas. There are other ways to pre concentrate biomolecules such as wetting/drying cycles and freezing/sublimation. However, adsorption is most important. If the pre-concentration did not occur—because of degradation of the minerals—other roles played by them such as protection against degradation, formation of polymers, or even as primitive cell walls would be seriously compromised. We studied the interaction of two artificial seawaters with kaolinite, bentonite, montmorillonite, goethite, ferrihydrite and quartz. One seawater has a major cation and anion composition similar to that of the oceans of the Earth 4.0 billion years ago (ASW 4.0 Ga). In the other, the major cations and anions are an average of the compositions of the seawaters of today (ASWT). When ASWT, which is rich in Na+ and Cl-, interacted with bentonite and montmorrilonite structural collapse occurred on the 001 plane. However, ASW 4.0 Ga, which is rich in Mg2+ and SO4 2-, did not induce this behavior. When ASW 4.0 Ga was reacted with the minerals for 24 h at room temperature and 80 °C, the release of Si and Al to the fluid was below 1 % of the amount in the minerals—meaning that dissolution of the minerals did not occur. In general, minerals adsorbed Mg2+ and K+ from the ASW 4.0 Ga and these cations could be used for the formation of polymers. Also, when the minerals were mixed with ASW 4.0 Ga at 80 °C and ASWT at room temperature or 80 °C it caused the precipitation of CaSO4•2H2O and halite, respectively. Finally, further experiments (adsorption, formation of polymers, protection of molecules against degradation, primitive cell wall formation) performed under the conditions described in this paper will probably be more representative of what happened on the prebiotic Earth.

  1. Prevalence and genotypes of Giardia duodenalis in 1-2 year old dairy cattle.

    PubMed

    Trout, James M; Santín, Mónica; Greiner, Ellis C; Fayer, Ronald

    2006-09-10

    To determine the prevalence of Giardia genotypes in 12-24 month old dairy heifers, fecal specimens were collected from two farms each in Vermont, New York, Pennsylvania, Maryland, Virginia, North Carolina, and Florida. Specimens, cleaned of fecal debris and concentrated using CsCl density gradient centrifugation, were subjected to PCR and DNA sequence analysis. Prevalence of Giardia infection, ranged from 11% to 75% on 14 farms with an average prevalence of 36% (204 positive cattle out of 571 examined). DNA sequence analysis of the 16S rRNA gene revealed 91% of the 204 Giardia isolates were Assemblage E, and 9% were Assemblage A. The prevalence of these genotypes varied greatly from farm to farm, with four farms having exclusively Assemblage E Giardia. Overall, Assemblage E was present in 33% of all animals tested and Assemblage A was present in 3% of the animals. Thus, while many of the heifers were infected with a genotype that is not known to be infectious for humans, 1-2 year old heifers on 10 of 14 farms did harbor zoonotic Assemblage A Giardia. Therefore, heifers cannot be overlooked as a potential source of human infectious cysts in the environment, with some farms representing a much higher risk than others.

  2. Rational Action Selection in 1 1/2- to 3-Year-Olds Following an Extended Training Experience

    ERIC Educational Resources Information Center

    Klossek, Ulrike M. H.; Dickinson, Anthony

    2012-01-01

    Previous studies failed to find evidence for rational action selection in children under 2 years of age. The current study investigated whether younger children required more training to encode the relevant causal relationships. Children between 1 1/2 and 3 years of age were trained over two sessions to perform actions on a touch-sensitive screen…

  3. News and Views: The brightest thing for 7.4 billion light years; Experiment starts; MAGIC accident; Last service for HST; Cassini collects rings, ring arcs and moons

    NASA Astrophysics Data System (ADS)

    2008-10-01

    March this year saw a gamma-ray burst 100 times brighter than any observed. Its unusual brightness, enough to make it a naked-eye object, arose because the beam of radiation was directed towards Earth, making it magnitude 5.3 at its peak - not bad for something halfway across the universe! Cassini continues to explore Saturn and its satellites by looking more closely at the moons and confirming that some of them have partial rings: clumps of ring material moving with them in orbit.

  4. Solid Waste Program Fiscal Year 1996 Multi-Year Program Plan WBS 1.2.1, Revision 1

    SciTech Connect

    1995-09-01

    This document contains the Fiscal Year 1996 Multi-Year Program Plan for the Solid Waste Program at the Hanford Reservation in Richland, Washington. The Solid Waste Program treats, stores, and disposes of a wide variety of solid wastes consisting of radioactive, nonradioactive and hazardous material types. Solid waste types are typically classified as transuranic waste, low-level radioactive waste, low-level mixed waste, and non-radioactive hazardous waste. This report describes the mission, goals and program strategies for the Solid Waste Program for fiscal year 1996 and beyond.

  5. The evolution of dust-obscured star formation activity in galaxy clusters relative to the field over the last 9 billion years

    NASA Astrophysics Data System (ADS)

    Alberts, Stacey; Pope, Alexandra; Brodwin, Mark; Atlee, David W.; Lin, Yen-Ting; Dey, Arjun; Eisenhardt, Peter R. M.; Gettings, Daniel P.; Gonzalez, Anthony H.; Jannuzi, Buell T.; Mancone, Conor L.; Moustakas, John; Snyder, Gregory F.; Stanford, S. Adam; Stern, Daniel; Weiner, Benjamin J.; Zeimann, Gregory R.

    2014-01-01

    We compare the star formation (SF) activity in cluster galaxies to the field from z = 0.3 to 1.5 using Herschel Spectral and Photometric Imaging REceiver 250 μm imaging and utilizing 274 clusters from the IRAC Shallow Cluster Survey (ISCS). These clusters were selected as rest-frame near-infrared overdensities over the 9 square degree Boötes field. This sample allows us to quantify the evolution of SF in clusters over a long redshift baseline without bias against active cluster systems. Using a stacking analysis, we determine the average star formation rates (SFRs) and specific SFRs (SSFR = SFR/M⋆) of stellar mass-limited (M ≥ 1.3 × 1010 M⊙), statistical samples of cluster and field galaxies, probing both the star-forming and quiescent populations. We find a clear indication that the average SF in cluster galaxies is evolving more rapidly than in the field, with field SF levels at z ≳ 1.2 in the cluster cores (r < 0.5 Mpc), in good agreement with previous ISCS studies. By quantifying the SF in cluster and field galaxies as an exponential function of cosmic time, we determine that cluster galaxies are evolving approximately two times faster than the field. Additionally, we see enhanced SF above the field level at z ˜ 1.4 in the cluster outskirts (r > 0.5 Mpc). These general trends in the cluster cores and outskirts are driven by the lower mass galaxies in our sample. Blue cluster galaxies have systematically lower SSFRs than blue field galaxies, but otherwise show no strong differential evolution with respect to the field over our redshift range. This suggests that the cluster environment is both suppressing the SF in blue galaxies on long time-scales and rapidly transitioning some fraction of blue galaxies to the quiescent galaxy population on short time-scales. We argue that our results are consistent with both strangulation and ram pressure stripping acting in these clusters, with merger activity occurring in the cluster outskirts.

  6. Temporal Learning in 4 1/2- and 6-Year-Old Children: Role of Instructions and Prior Knowledge.

    ERIC Educational Resources Information Center

    Droit, Sylvie; And Others

    1990-01-01

    Examined the role of prior temporal knowledge of 4 1/2- and 6-year-olds through the use of high-rate, interval, and minimal instructions in a fixed-interval training schedule. Determined that the subjects' learning depended on their verbal self-control skills. (BC)

  7. Great Plains makes 100 billion cubic feet

    SciTech Connect

    Not Available

    1987-03-01

    The Great Plains coal gasification plant on January 18, 1987 produced its 100 billionth cubic foot of gas since start-up July 28, 1984. Owned by the Department of Energy and operated by ANG Coal Gasification Company, the plant uses the Lurgi process to produce about 50 billion cubic feet per year of gas from five million tons per year of lignite. The plant has been performing at well above design capacity.

  8. Deepwater royalty relief product of 3 1/2 year U.S. political effort

    SciTech Connect

    Davis, R.E.; Neff, S.

    1996-04-01

    Against the backdrop of more than 20 years of increasingly stringent environmental regulation, ever-expanding exploration and development moratoria on the Outer Continental Shelf (OCS), and reductions in producer tax incentives, oil and natural gas exploration companies active in deep waters of the Gulf of Mexico recently won a significant legislative victory. On Nov. 28, 1995, President Clinton signed into law S.395, the Alaska Power Administration Sale Act. Title 3 of S.395 embodies the Outer Continental Shelf Deep Water Royalty Relief Act. This landmark legislation provides substantial incentives for oil and natural gas production in the gulf of Mexico by temporarily eliminating royalties on certain deepwater leases. It is the first direct incentive for oil and gas production enacted at the federal level in many years. This paper reviews the elements used to arrive at this successful legislation including the congressional leadership. It describes debates, cabinet level discussions, and use of parlimentary procedures.

  9. Three-dimensional preservation of cellular and subcellular structures suggests 1.6 billion-year-old crown-group red algae

    PubMed Central

    Bengtson, Stefan; Sallstedt, Therese; Belivanova, Veneta; Whitehouse, Martin

    2017-01-01

    The ~1.6 Ga Tirohan Dolomite of the Lower Vindhyan in central India contains phosphatized stromatolitic microbialites. We report from there uniquely well-preserved fossils interpreted as probable crown-group rhodophytes (red algae). The filamentous form Rafatazmia chitrakootensis n. gen, n. sp. has uniserial rows of large cells and grows through diffusely distributed septation. Each cell has a centrally suspended, conspicuous rhomboidal disk interpreted as a pyrenoid. The septa between the cells have central structures that may represent pit connections and pit plugs. Another filamentous form, Denaricion mendax n. gen., n. sp., has coin-like cells reminiscent of those in large sulfur-oxidizing bacteria but much more recalcitrant than the liquid-vacuole-filled cells of the latter. There are also resemblances with oscillatoriacean cyanobacteria, although cell volumes in the latter are much smaller. The wider affinities of Denaricion are uncertain. Ramathallus lobatus n. gen., n. sp. is a lobate sessile alga with pseudoparenchymatous thallus, “cell fountains,” and apical growth, suggesting florideophycean affinity. If these inferences are correct, Rafatazmia and Ramathallus represent crown-group multicellular rhodophytes, antedating the oldest previously accepted red alga in the fossil record by about 400 million years. PMID:28291791

  10. [3 1/2 years experiences with ECCE with tunnel incision].

    PubMed

    Häberle, H; Anders, N; Antoni, H J; Pham, D T; Wollensak, J

    1997-01-01

    Since January 1992 planned extracapsular cataract extraction (ECCE) is performed routinely with the no-stitch technique at our clinic. To minimize surgically induced astigmatism further, modified wound constructions for planned ECCE with on 1.1-mm tunnel width were evaluated. The follow-up time was up to 3 years postoperatively. For 250 eyes wound closure was performed prospectively either sutureless (n = 70), with a single perpendicular suture (n = 100) or cross sutures (n = 40) at the 12 o'clock position or sutureless in the temporal position (n = 40). The complication rate was 4% (filtering bleb, iris prolapse or transient hypotonia). There were no wound ruptures, but once endophthalmitis was observed. Late mean astigmatism after up to 3 years follow-up for vertical incision was 2.05 +/- 1.16 D (1.01 +/- 0.96 D preoperatively) for sutureless wound closure, 1.63 +/- 1.08 D (0.86 +/- 0.95 D) for perpendicular and 1.76 +/- 0.88 D (0.73 +/- 0.55 D) for cross-sutures. A temporal incision resulted in 0.78 +/- 0.52 D (1.0 +/- 0.69 D) of astigmatism and was only performed on eyes with against the rule astigmatism preoperatively. Surgically induced astigmatism was stabilized early. For with the rule astigmatism preoperatively, a 12 o'clock incision with a perpendicular single suture is recommended and for against the rule astigmatism, a temporal incision.

  11. Four billion people facing severe water scarcity

    PubMed Central

    Mekonnen, Mesfin M.; Hoekstra, Arjen Y.

    2016-01-01

    Freshwater scarcity is increasingly perceived as a global systemic risk. Previous global water scarcity assessments, measuring water scarcity annually, have underestimated experienced water scarcity by failing to capture the seasonal fluctuations in water consumption and availability. We assess blue water scarcity globally at a high spatial resolution on a monthly basis. We find that two-thirds of the global population (4.0 billion people) live under conditions of severe water scarcity at least 1 month of the year. Nearly half of those people live in India and China. Half a billion people in the world face severe water scarcity all year round. Putting caps to water consumption by river basin, increasing water-use efficiencies, and better sharing of the limited freshwater resources will be key in reducing the threat posed by water scarcity on biodiversity and human welfare. PMID:26933676

  12. Four billion people facing severe water scarcity.

    PubMed

    Mekonnen, Mesfin M; Hoekstra, Arjen Y

    2016-02-01

    Freshwater scarcity is increasingly perceived as a global systemic risk. Previous global water scarcity assessments, measuring water scarcity annually, have underestimated experienced water scarcity by failing to capture the seasonal fluctuations in water consumption and availability. We assess blue water scarcity globally at a high spatial resolution on a monthly basis. We find that two-thirds of the global population (4.0 billion people) live under conditions of severe water scarcity at least 1 month of the year. Nearly half of those people live in India and China. Half a billion people in the world face severe water scarcity all year round. Putting caps to water consumption by river basin, increasing water-use efficiencies, and better sharing of the limited freshwater resources will be key in reducing the threat posed by water scarcity on biodiversity and human welfare.

  13. Ultra-dense billion year memory chip

    SciTech Connect

    2009-01-01

    This video shows an iron nanoparticle shuttle moving through a carbon nanotube in the presence of a low voltage electrical current. The shuttles position inside the tube can function as a high-density nonvolatile memory element. (Courtesy of /Zettl Research Group, Lawrence Berkeley National Laboratory and University of California at Berkeley.)

  14. Palaeoclimates: the first two billion years

    PubMed Central

    Kasting, James F; Ono, Shuhei

    2006-01-01

    Earth's climate during the Archaean remains highly uncertain, as the relevant geologic evidence is sparse and occasionally contradictory. Oxygen isotopes in cherts suggest that between 3.5 and 3.2 Gyr ago (Ga) the Archaean climate was hot (55–85 °C); however, the fact that these cherts have experienced only a modest amount of weathering suggests that the climate was temperate, as today. The presence of diamictites in the Pongola Supergroup and the Witwatersrand Basin of South Africa suggests that by 2.9 Ga the climate was glacial. The Late Archaean was relatively warm; then glaciation (possibly of global extent) reappeared in the Early Palaeoproterozoic, around 2.3–2.4 Ga. Fitting these climatic constraints with a model requires high concentrations of atmospheric CO2 or CH4, or both. Solar luminosity was 20–25% lower than today, so elevated greenhouse gas concentrations were needed just to keep the mean surface temperature above freezing. A rise in O2 at approximately 2.4 Ga, and a concomitant decrease in CH4, provides a natural explanation for the Palaeoproterozoic glaciations. The Mid-Archaean glaciations may have been caused by a drawdown in H2 and CH4 caused by the origin of bacterial sulphate reduction. More work is needed to test this latter hypothesis. PMID:16754607

  15. Factor analysis of the WISC-R (Spanish version) at 11 age levels between 6 1/2 and 16 1/2 years.

    PubMed

    Gass, C S; Demsky, Y I; Martin, P C

    1998-01-01

    The Spanish version of the Wechsler Intelligence Scale for Children-Revised (WISC-R, Wechsler, 1974)-the Escala de Inteligencia para Niños-Revision (EIWN-R, Wechsler, 1982)-has a potentially important role in the assessment of Hispanic children. However, little is known regarding its psychometric characteristics. This study used the normative data from the EIWN-R standardization sample (N = 532 Cuban Americans) to examine its factorial composition and general comparability with the WISC-R. Within each of the 11 age groups (ages 6 1/2 to 16 1/2), the correlation matrix of raw scores was subjected to a principal components analysis and varimax rotation. The results supported a 2-factor solution across age groups roughly corresponding with Wechsler's verbal and performance dimensions. The existence of a meaningful third factor, which has empirical support in the WISC-R literature, failed to emerge for the EIWN-R.

  16. World population beyond six billion.

    PubMed

    Gelbard, A; Haub, C; Kent, M M

    1999-03-01

    This world report reviews population growth pre-1900, population change during 1900-50 and 1950-2000, causes and effects of population change and projections to 2050. World population grew from 2 billion in 1900 to almost 6 billion in 2000. Population showed more rapid growth in the 17th and 18th centuries. Better hygiene and public sanitation in the 19th century led to expanded life expectancies and quicker growth, primarily in developed countries. Demographic transition in the 19th and 20th centuries was the result of shifts from high to low mortality and fertility. The pace of change varies with culture, level of economic development, and other factors. Not all countries follow the same path of change. The reproductive revolution in the mid-20th century and modern contraception led to greater individual control of fertility and the potential for rapid fertility decline. Political and cultural barriers that limit access affect the pace of decline. Population change is also affected by migration. Migration has the largest effect on the distribution of population. Bongaarts explains differences in fertility by the proportion in unions, contraceptive prevalence, infertility, and abortion. Educational status has a strong impact on adoption of family planning. Poverty is associated with multiple risks. In 2050, population could reach 10.7 billion or remain low at 7.3 billion.

  17. To reactivate or not to reactivate: nature and varied behavior of structural inheritance in the Proterozoic basement of the Eastern Colorado mineral belt over 1.7 billion years of earth history

    USGS Publications Warehouse

    Caine, Jonathan Saul; Ridley, John; Wessel, Zachary R.

    2010-01-01

    The eastern central Front Range of the Rocky Mountains in Colorado has long been a region of geologic interest because of Laramide-age hydrothermal polymetallic vein-related ores. The region is characterized by a well-exposed array of geologic structures associated with ductile and brittle deformation, which record crustal strain over 1.7 billion years of continental growth and evolution. The mineralized areas lie along a broad linear zone termed the Colorado Mineral Belt. This lineament has commonly been interpreted as following a fundamental boundary, such as a suture zone, in the North American Proterozoic crust that acted as a persistent zone of weakness localizing the emplacement of magmas and associated hydrothermal fluid flow. However, the details on the controls of the location, orientation, kinematics, density, permeability, and relative strength of various geological structures and their specific relationships to mineral deposit formation are not related to Proterozoic ancestry in a simple manner. The objectives of this field trip are to show key localities typical of the various types of structures present, show recently compiled and new data, offer alternative conceptual models, and foster dialogue. Topics to be discussed include: (1) structural history of the eastern Front Range; (2) characteristics, kinematics, orientations, and age of ductile and brittle structures and how they may or may not relate to one another and mineral deposit permeability; and (3) characteristics, localization, and evolution of the metal and non–metal-bearing hydrothermal systems in the eastern Colorado Mineral Belt.

  18. Quantitative sensory tests before and 1(1/2) years after orthognathic surgery: a cross-sectional study.

    PubMed

    Baad-Hansen, L; Arima, T; Arendt-Nielsen, L; Neumann-Jensen, B; Svensson, P

    2010-05-01

    Quality control is very important in relation to invasive and lengthy treatments, such as integrated orthodontic and surgical correction of dentofacial deformities. The aim of this cross-sectional study was to compare self-reported somatosensory disturbances and quantitative sensory testing (QST) findings between two groups of patients and a healthy control group (n = 24); one group (n = 21) scheduled for bimaxillary orthognathic surgery (BOS) (pre-op) and one group (n = 24) examined 1(1/2) years after BOS (post-op). Self-reported data on pain and somatosensory disturbances were collected, and QST was performed at six trigeminal and one extratrigeminal site. Sensitivity to brush stroke, tactile stimuli, pinprick, two-point-discrimination threshold (2P-DT), pinch pain threshold (PiPT) and pressure pain threshold (PPT) was evaluated. Results were analysed with anovas, Spearman's Correlation, and chi square tests. Eight per cent of post-op patients reported intra-oral, 46% extra-oral, and 46% no somatosensory disturbances. Sensitivity to brush stroke, pinprick and 2P-DT was significantly increased at all examination sites in the post-op patients compared with healthy controls (P < 0.002). Tactile thresholds and PPT did not differ between groups (P > 0.071). Pinch pain threshold were decreased in pre-op patients compared with controls (P < 0.040). Self-reported somatosensory disturbances were not correlated with QST findings. In conclusion; 1(1/2) years after BOS, a large proportion of patients reported somatosensory disturbances and was hypersensitive to mechanical stimuli when compared with pre-op patients and healthy controls. Pre-op patients showed minor somatosensory changes. In addition to patients serving as their own control in prospective studies, a healthy control group and extratrigeminal control sites should be included in future studies.

  19. A reconstruction of Archean biological diversity based on molecular fossils from the 2.78 to 2.45 billion-year-old Mount Bruce Supergroup, Hamersley Basin, Western Australia

    NASA Astrophysics Data System (ADS)

    Brocks, Jochen J.; Buick, Roger; Summons, Roger E.; Logan, Graham A.

    2003-11-01

    Bitumens extracted from 2.7 to 2.5 billion-year-old (Ga) shales of the Fortescue and Hamersley Groups in the Pilbara Craton, Western Australia, contain traces of molecular fossils. Based on a combination of molecular characteristics typical of many Precambrian bitumens, their consistently and unusually high thermal maturities, and their widespread distribution throughout the Hamersley Basin, the bitumens can be characterized as 'probably of Archean age'. Accepting this interpretation, the biomarkers open a new window on Archean biodiversity. The presence of hopanes in the Archean rocks confirms the antiquity of the domain Bacteria, and high relative concentrations of 2α-methylhopanes indicate that cyanobacteria were important primary producers. Oxygenic photosynthesis therefore evolved > 2.7 Ga ago, and well before independent evidence suggests significant levels of oxygen accumulated in the atmosphere. Moreover, the abundance of cyanobacterial biomarkers in shales interbedded with oxide-facies banded iron formations (BIF) indicates that although some Archean BIF might have been formed by abiotic photochemical processes or anoxygenic phototrophic bacteria, those in the Hamersley Group formed as a direct consequence of biological oxygen production. Biomarkers of the 3β-methylhopane series suggest that microaerophilic heterotrophic bacteria, probably methanotrophs or methylotrophs, were active in late Archean environments. The presence of steranes in a wide range of structures with relative abundances like those from late Paleoproterozoic to Phanerozoic sediments is convincing evidence for the existence of eukaryotes in the late Archean, 900 Ma before visible fossil evidence indicates that the lineage arose. Sterol biosynthesis in extant eukaryotes requires molecular oxygen. The presence of steranes together with biomarkers of oxygenic photosynthetic cyanobacteria suggests that the concentration of dissolved oxygen in some regions of the upper water column was

  20. White House Budget Proposal Would Provide National Science Foundation With 1.2% Increase

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2014-03-01

    The proposed 7.255 billion budget request for the U.S. National Science Foundation (NSF) for fiscal year (FY) 2015, announced by the White House on 4 March, would increase funding just 83 million, 1.2% above the FY 2014 estimate (see Table 1). The budget for NSF's Directorate for Geosciences (GEO) would nudge up 0.1% to 1.304 billion, an increase of 1.36 million (see Table 2).

  1. Life with Four Billion Atoms

    SciTech Connect

    Knight, Thomas

    2013-04-10

    Today it is commonplace to design and construct single silicon chips with billions of transistors. These are complex systems, difficult (but possible) to design, test, and fabricate. Remarkably, simple living systems can be assembled from a similar number of atoms, most of them in water molecules. In this talk I will present the current status of our attempts at full understanding and complexity reduction of one of the simplest living systems, the free-living bacterial species Mesoplasma florum. This 400 nm diameter cell thrives and replicates every 40 minutes with a genome of only 800 kilobases. Our recent experiments using transposon gene knockouts identified 354 of 683 annotated genes as inessential in laboratory culture when inactivated individually. While a functional redesigned genome will certainly not remove all of those genes, this suggests that roughly half the genome can be removed in an intentional redesign. I will discuss our recent knockout results and methodology, and our future plans for Genome re-engineering using targeted knock-in/knock-out double recombination; whole cell metabolic models; comprehensive whole cell metabolite measurement techniques; creation of plug-and-play metabolic modules for the simplified organism; inherent and engineered biosafety control mechanisms. This redesign is part of a comprehensive plan to lay the foundations for a new discipline of engineering biology. Engineering biological systems requires a fundamentally different viewpoint from that taken by the science of biology. Key engineering principles of modularity, simplicity, separation of concerns, abstraction, flexibility, hierarchical design, isolation, and standardization are of critical importance. The essence of engineering is the ability to imagine, design, model, build, and characterize novel systems to achieve specific goals. Current tools and components for these tasks are primitive. Our approach is to create and distribute standard biological parts

  2. Lamellar magnetism and exchange bias in billion-year-old metamorphic titanohematite with nanoscale ilmenite exsolution lamellae: II. Exchange-bias at 5 K after field-free cooling of NRM and after cooling in a +5 T field

    NASA Astrophysics Data System (ADS)

    Robinson, Peter; McEnroe, Suzanne A.; Jackson, M.

    2016-11-01

    This is the second of three papers investigating properties of titanohematite-bearing quartzo-feldspathic rocks that create a significant remanent magnetic anomaly in the Modum District, South Norway. The first paper provided initial magnetic results, mineralogical characterization and evidence for the presence of lamellar magnetism. In this paper, knowledge of lamellar magnetic properties is explored through experiments where ilmenite lamellae were magnetized below 57 K, and interact magnetically along interfaces with the titanohematite host. Samples with known NRM directions were placed in specific orientations in an MPMS then cooled in zero field to 5 K, where hysteresis loops were measured in fields up to 5 Tesla. This assured that results were ultimately related to the natural lamellar magnetism produced during cooling ˜ 1 billion years ago. In a second set of experiments the same oriented samples, were subjected to a +5 Tesla field then field cooled to 5 K before hysteresis experiments. The first experiments consistently produced asymmetric shifted hysteresis loops with two loop separations, one in a positive field and one in a negative field. Without exception, when the NRM was oriented toward the negative field end of the MPMS, the bimodal loop showed a dominant loop separation in a positive field. By contrast, when the NRM was oriented toward the positive field end of the MPMS, the bimodal loop showed a dominant loop separation in a negative field. Both observations are consistent with antiferromagnetic coupling between the hard magnetization of ilmenite and the more easily shifted lamellar magnetism of the hematite. The bimodal nature of the loops indicates that the NRMs are vector sums of natural lamellar moments, which are oriented both positively and negatively, and that these opposite moments control the orientations of ilmenite magnetizations when cooling through 57 K. Here, extreme exchange biases up to 1.68 Tesla were measured. The second set of

  3. Interaction, at Ambient Temperature and 80 °C, between Minerals and Artificial Seawaters Resembling the Present Ocean Composition and that of 4.0 Billion Years Ago.

    PubMed

    Carneiro, Cristine E A; Stabile, Antonio C; Gomes, Frederico P; da Costa, Antonio C S; Zaia, Cássia T B V; Zaia, Dimas A M

    2016-10-25

    Probably one of the most important roles played by minerals in the origin of life on Earth was to pre-concentrate biomolecules from the prebiotic seas. There are other ways to pre concentrate biomolecules such as wetting/drying cycles and freezing/sublimation. However, adsorption is most important. If the pre-concentration did not occur-because of degradation of the minerals-other roles played by them such as protection against degradation, formation of polymers, or even as primitive cell walls would be seriously compromised. We studied the interaction of two artificial seawaters with kaolinite, bentonite, montmorillonite, goethite, ferrihydrite and quartz. One seawater has a major cation and anion composition similar to that of the oceans of the Earth 4.0 billion years ago (ASW 4.0 Ga). In the other, the major cations and anions are an average of the compositions of the seawaters of today (ASWT). When ASWT, which is rich in Na(+) and Cl(-), interacted with bentonite and montmorrilonite structural collapse occurred on the 001 plane. However, ASW 4.0 Ga, which is rich in Mg(2+) and SO4(2-), did not induce this behavior. When ASW 4.0 Ga was reacted with the minerals for 24 h at room temperature and 80 °C, the release of Si and Al to the fluid was below 1 % of the amount in the minerals-meaning that dissolution of the minerals did not occur. In general, minerals adsorbed Mg(2+) and K(+) from the ASW 4.0 Ga and these cations could be used for the formation of polymers. Also, when the minerals were mixed with ASW 4.0 Ga at 80 °C and ASWT at room temperature or 80 °C it caused the precipitation of CaSO4∙2H2O and halite, respectively. Finally, further experiments (adsorption, formation of polymers, protection of molecules against degradation, primitive cell wall formation) performed under the conditions described in this paper will probably be more representative of what happened on the prebiotic Earth.

  4. Lamellar magnetism and exchange bias in billion-year-old metamorphic titanohematite with nanoscale ilmenite exsolution lamellae - II: exchange-bias at 5 K after field-free cooling of NRM and after cooling in a +5 T field

    NASA Astrophysics Data System (ADS)

    Robinson, Peter; McEnroe, Suzanne A.; Jackson, Mike

    2017-02-01

    This is the second of three papers investigating properties of titanohematite-bearing quartzo-feldspathic rocks that create a significant remanent magnetic anomaly in the Modum District, South Norway. The first paper provided initial magnetic results, mineralogical characterization and evidence for the presence of lamellar magnetism. In this paper, knowledge of lamellar magnetic properties is explored through experiments where ilmenite lamellae were magnetized below 57 K, and interact magnetically along interfaces with the titanohematite host. Samples with known NRM directions were placed in specific orientations in an MPMS then cooled in zero field to 5 K, where hysteresis loops were measured in fields up to 5 Tesla. This assured that results were ultimately related to the natural lamellar magnetism produced during cooling ˜1 billion years ago. In a second set of experiments the same oriented samples, were subjected to a +5 Tesla (T) field then field cooled to 5 K before hysteresis experiments. The first experiments consistently produced asymmetric shifted hysteresis loops with two loop separations, one in a positive field and one in a negative field. Without exception, when the NRM was oriented toward the negative field end of the MPMS, the bimodal loop showed a dominant loop separation in a positive field. By contrast, when the NRM was oriented toward the positive field end of the MPMS, the bimodal loop showed a dominant loop separation in a negative field. Both observations are consistent with antiferromagnetic coupling between the hard magnetization of ilmenite and the more easily shifted lamellar magnetism of the hematite. The bimodal nature of the loops indicates that the NRMs are vector sums of natural lamellar moments, which are oriented both positively and negatively, and that these opposite moments control the orientations of ilmenite magnetizations when cooling through 57 K. Here, extreme exchange biases up to 1.68 T were measured. The second set of

  5. Use of iron supplements in children aged 1-2 years with iron deficiency anemia: A cross-sectional study

    PubMed Central

    Sezik, Handan Atsiz; Can, Huseyin; Kurnaz, Mehmet Ali; Tuna, Mine; Ay, Zeynep

    2015-01-01

    Objectives: Iron deficiency (ID) is the most common nutritional problem in the world and is the most common cause of childhood anemia. In this study, our aim was to find out about the state of usage of iron preparation, which is distributed free of charge by the Ministry of Health, for the infants between 4-12 months in our country, as well as detecting the awareness degree of families those who are informed about iron-deficiency anemia (IDA), prophylaxis of the drug and to determine the drug’s effectiveness. Methods: It was a cross-sectional survey. The laboratory values from the files of the children aged 1-2 those who visited our hospital’s department of pediatrics, between January 2010 to August 2013, were collected. The survey included families who have children diagnosed with IDA. Questions included about families’ sociodemographic characteristics, the state of the usage of the iron drug, how much information received in terms of the side effects- consumption period and dosage. Results: A total of 139 children were enrolled in our study. While 77.7% of the families who participated stated that (n = 108) iron medicine was prescribed other 43.2% of families stated (n = 60) was prescribed and they were informed about iron pills and IDA. 25.9% of families had received information about drug’s side effects, 74.8% of them had information about period of consumption and 77.7% said they were given information about the drug dose. The average duration of use of iron medicine was 6.98±4.52 (min: 1, max: 24) months. It has been noted that; parent’s education level, mother’s occupation, child’s gender, how the child was born and receiving information about how to use the medicine had no effects on usage of the drug in children. Nevertheless, it has been noticed that, when the families were given proper information the drug use increased and the patients compliance with medications also increased. Conclusion: We believe that, due to frequent diagnosis of

  6. Project Ice Storm: Prenatal Maternal Stress Affects Cognitive and Linguistic Functioning in 5 1/2-Year-Old Children

    ERIC Educational Resources Information Center

    Laplante, David P.; Brunet, Alain; Schmitz, Norbert; Ciampi, Antonio; King, Suzanne

    2008-01-01

    The study used data from Project Ice Storm to determine the extent to which exposure to prenatal maternal stress due to a natural disaster can explain variance in the intellectual and language performance of offspring at age 5 1/2.

  7. Countdown to Six Billion Teaching Kit.

    ERIC Educational Resources Information Center

    Zero Population Growth, Inc., Washington, DC.

    This teaching kit features six activities focused on helping students understand the significance of the world population reaching six billion for our society and our environment. Featured activities include: (1) History of the World: Part Six Billion; (2) A Woman's Place; (3) Baby-O-Matic; (4) Earth: The Apple of Our Eye; (5) Needs vs. Wants; and…

  8. Eight billion asteroids in the Oort cloud

    NASA Astrophysics Data System (ADS)

    Shannon, Andrew; Jackson, Alan P.; Veras, Dimitri; Wyatt, Mark

    2015-01-01

    The Oort cloud is usually thought of as a collection of icy comets inhabiting the outer reaches of the Solar system, but this picture is incomplete. We use simulations of the formation of the Oort cloud to show that ˜4 per cent of the small bodies in the Oort cloud should have formed within 2.5 au of the Sun, and hence be ice-free rock-iron bodies. If we assume that these Oort cloud asteroids have the same size distribution as their cometary counterparts, the Large Synoptic Survey Telescope should find roughly a dozen Oort cloud asteroids during 10 years of operations. Measurement of the asteroid fraction within the Oort cloud can serve as an excellent test of the Solar system's formation and dynamical history. Oort cloud asteroids could be of particular concern as impact hazards as their high mass density, high impact velocity, and low visibility make them both hard to detect and hard to divert or destroy. However, they should be a rare class of object, and we estimate globally catastrophic collisions should only occur about once per billion years.

  9. Colleges' Billion-Dollar Campaigns Feel the Economy's Sting

    ERIC Educational Resources Information Center

    Masterson, Kathryn

    2009-01-01

    The economy's collapse has caught up with the billion-dollar campaign. In the past 12 months, the amount of money raised by a dozen of the colleges engaged in higher education's biggest fund-raising campaigns fell 32 percent from the year before. The decline, which started before the worst of the recession, has forced colleges to postpone…

  10. Projecting a world of 10.4 billion.

    PubMed

    Yanagishita, M

    1988-01-01

    Summary data are presented from the World Bank's "World Population 1987-88: Short and Long-Term Estimates by Age and Sex with Related Demographic Statistics." The projections do not differ much from those in the World Bank's 1985 projection except for large upward revisions for South Asian and West Asian countries and especially large upward revisions for Kenya, Ethiopia, Burkina Faso, Nigeria, and Egypt. World population is expected to reach 10.4 billion in 2100 and to stabilize at 10 billion around year 2070. Intermediate figures are given for year 2000 (6.2 billion) and year 2050 (9.5 billion). The fifteen most populous countries in 2100 will be (in millions) China (1683), India (1678), Nigeria (529), Pakistan (395), USSR (385), Indonesia (363), Brazil (292), US (279), Ethiopia (204), Mexico (197), Iran (157), Philippines (137), Egypt (132), Japan (124), and Tanzania (123). The world's annual growth rate (currently 1.7%) will decrease to .9% in 2025 and .07% in 2100 due to decreasing birth rates, especially in Africa. Nevertheless, the population of Sub-Saharan Africa will be 5 times its present size. The slowest annual growth will be for Europe, North America, and China; and the highest for Sri Lanka, Pakistan, and Bangladesh.

  11. Americans Are Spending Billions Nipping and Tucking

    MedlinePlus

    ... Tucking New report details costs of most popular plastic surgery procedures To use the sharing features on ... A new report from the American Society of Plastic Surgeons (ASPS) found that Americans spent $16 billion ...

  12. Environmental change explains cichlid adaptive radiation at Lake Malawi over the past 1.2 million years.

    PubMed

    Ivory, Sarah J; Blome, Margaret W; King, John W; McGlue, Michael M; Cole, Julia E; Cohen, Andrew S

    2016-10-18

    Long paleoecological records are critical for understanding evolutionary responses to environmental forcing and unparalleled tools for elucidating the mechanisms that lead to the development of regions of high biodiversity. We use a 1.2-My record from Lake Malawi, a textbook example of biological diversification, to document how climate and tectonics have driven ecosystem and evolutionary dynamics. Before ∼800 ka, Lake Malawi was much shallower than today, with higher frequency but much lower amplitude water-level and oxygenation changes. Since ∼800 ka, the lake has experienced much larger environmental fluctuations, best explained by a punctuated, tectonically driven rise in its outlet location and level. Following the reorganization of the basin, a change in the pacing of hydroclimate variability associated with the Mid-Pleistocene Transition resulted in hydrologic change dominated by precession rather than the high-latitude teleconnections recorded elsewhere. During this time, extended, deep lake phases have abruptly alternated with times of extreme aridity and ecosystem variability. Repeated crossings of hydroclimatic thresholds within the lake system were critical for establishing the rhythm of diversification, hybridization, and extinction that dominate the modern system. The chronology of these changes closely matches both the timing and pattern of phylogenetic history inferred independently for the lake's extraordinary array of cichlid fish species, suggesting a direct link between environmental and evolutionary dynamics.

  13. The Prevalence of Mental Health Problems in Children 1 1/2 Years of Age--The Copenhagen Child Cohort 2000

    ERIC Educational Resources Information Center

    Skovgaard, Anne Mette; Houmann, Tine; Christiansen, Eva; Landorph, Susanne; Jorgensen, Torben; Olsen, E. M.; Heering, K.; Kaas-Nielsen, S.; Samberg, V.; Lichtenberg, A.

    2007-01-01

    Background: The Copenhagen Child Cohort, CCC 2000, was established to investigate developmental psychopathology prospectively from birth in a general population. Methods: A random sample of 211 children from the CCC 2000 was investigated when the children were 1 1/2 years of age. The prevalence and associates of mental health problems and…

  14. Waste and decontamination services FY 94 Multi-Year Program Plan Phase II WBS No. 1.2.3

    SciTech Connect

    Cruz, E.A.

    1994-05-01

    During the remediation of the Hanford Site large volumes of radioactive and mixed solid waste are expected to be produced, thus creating the need for subsequent decontamination, treatment, storage, and/or waste disposal. The program mission is to manage current and future contaminated solid waste streams in a safe, responsible, cost effective and legally compliant manner. This document presents the strategy and technical requirements, along with key objectives and deliverables for the waste and decontamination services program for fiscal year 1994. Time schedules, cost estimates, and justification for each proposed activity are given in tables and charts.

  15. Ubiquitous Supercritical Wing Design Cuts Billions in Fuel Costs

    NASA Technical Reports Server (NTRS)

    2015-01-01

    A Langley Research Center engineer’s work in the 1960s and ’70s to develop a wing with better performance near the speed of sound resulted in a significant increase in subsonic efficiency. The design was shared with industry. Today, Renton, Washington-based Boeing Commercial Airplanes, as well as most other plane manufacturers, apply it to all their aircraft, saving the airline industry billions of dollars in fuel every year.

  16. Oncology pharma costs to exceed $150 billion by 2020.

    PubMed

    2016-10-01

    Worldwide costs of oncology drugs will rise above $150 billion by 2020, according to a report by the IMS Institute for Healthcare Informatics. Many factors are in play, according to IMS, including the new wave of expensive immunotherapies. Pembrolizumab (Keytruda), priced at $150,000 per year per patient, and nivolumab (Opdivo), priced at $165,000, may be harbingers of the market for cancer immunotherapies.

  17. Teledesic pushes $9-billion, 900-satellite system

    NASA Astrophysics Data System (ADS)

    1994-03-01

    Teledesic Corp. is seeking FCC approval to deploy a communication satellite system, costing $9 billion and using more than 900 satellites in low Earth orbit. This system would provide telephone and broadband data service to remote areas and developing countries. The two major stockholders in Teledesic are William Gates (of Microsoft Corp.) and Craig McCaw (of McCaw Cellular Communications). Each satellite would act as a node in a packet-switching network. The satellites would provide continuous global coverage.

  18. Prevalence of species and genotypes of Cryptosporidium found in 1-2-year-old dairy cattle in the eastern United States.

    PubMed

    Fayer, Ronald; Santín, Mónica; Trout, James M; Greiner, Ellis

    2006-01-30

    The prevalence of Cryptosporidium species in 1-2-year-old heifers was determined for 571 animals on 14 dairy farms in seven states on the East Coast of the United States. A fecal specimen collected directly from each heifer was processed to concentrate oocysts that were then examined by polymerase chain reaction (PCR). For every PCR-positive specimen the 18S rRNA gene of Cryptosporidium was sequenced. Cryptosporidium was identified by PCR from heifers on 13 of 14 farms. On all except four farms groups of heifers were housed in a barn or in large covered pens. Others were pastured. From many of the same farms an earlier study reported that 41% of 393 pre-weaned calves and 26.2% of 447 post-weaned calves were infected. In the present study, 11.9% of 571 heifers were infected with Cryptosporidium, 0.7% with Cryptosporidium parvum, the zoonotic species. Of 68 PCR-positive specimens characterized by gene sequencing 1, 4, 10, 24, and 29 calves were infected with Cryptosporidium suis, Cryptosporidium parvum, Cryptosporidium deer-like genotype, Cryptosporidium bovis, and Cryptosporidium andersoni, respectively. These findings demonstrate a lower prevalence of infection in 1-2-year-old dairy cattle than in younger cattle as well as a change in the diversity of species present. Consequently, the risk of humans acquiring infection with C. parvum from exposure to feces from yearling and older cattle appears much lower than from exposure to pre-weaned calves.

  19. Phase 1/2 study of carfilzomib plus melphalan and prednisone in patients aged over 65 years with newly diagnosed multiple myeloma.

    PubMed

    Moreau, Philippe; Kolb, Brigitte; Attal, Michel; Caillot, Denis; Benboubker, Lotfi; Tiab, Mourad; Touzeau, Cyrille; Leleu, Xavier; Roussel, Murielle; Chaleteix, Carine; Planche, Lucie; Chiffoleau, Anne; Fortin, June; Avet-Loiseau, Hervé; Mary, Jean-Yves; Hulin, Cyrille; Facon, Thierry

    2015-05-14

    This phase 1/2 dose-escalation study investigated the combination of carfilzomib with melphalan and prednisone (CMP) in patients aged >65 years with newly diagnosed multiple myeloma (MM). Melphalan and prednisone were administered orally on days 1 to 4; carfilzomib was IV administered on days 1, 2, 8, 9, 22, 23, 29, and 30 of a 42-day cycle. Patients received up to 9 cycles of CMP. In the phase 1 dose-escalation portion, the primary objectives were to determine the incidence of dose-limiting toxicities during the first cycle of CMP treatment to define the maximal tolerated dose (MTD) of carfilzomib. In the phase 2 portion, the primary objective was to evaluate the overall response rate (ORR) of CMP. In the phase 1 portion of the study, 24 patients received CMP at carfilzomib dosing levels of 20 mg/m(2), 27 mg/m(2), 36 mg/m(2), and 45 mg/m(2). The MTD was established as 36 mg/m(2). In the phase 2 portion of the study, 44 patients were enrolled at the MTD. Among 50 efficacy-evaluable patients treated at the MTD, the ORR was 90%. The projected 3-year overall survival rate was 80%. The combination of CMP was observed to be effective in elderly patients with newly diagnosed MM. This trial was registered at www.clinicaltrials.gov as #NCT01279694 (Eudract identifier 2010-019462-92).

  20. Spherule beds 3.47-3.24 billion years old in the Barberton Greenstone Belt, South Africa: a record of large meteorite impacts and their influence on early crustal and biological evolution.

    PubMed

    Lowe, Donald R; Byerly, Gary R; Kyte, Frank T; Shukolyukov, Alexander; Asaro, Frank; Krull, Alexandra

    2003-01-01

    Four layers, S1-S4, containing sand-sized spherical particles formed as a result of large meteorite impacts, occur in 3.47-3.24 Ga rocks of the Barberton Greenstone Belt, South Africa. Ir levels in S3 and S4 locally equal or exceed chondritic values but in other sections are at or only slightly above background. Most spherules are inferred to have formed by condensation of impact-produced rock vapor clouds, although some may represent ballistically ejected liquid droplets. Extreme Ir abundances and heterogeneity may reflect element fractionation during spherule formation, hydraulic fractionation during deposition, and/or diagenetic and metasomatic processes. Deposition of S1, S2, and S3 was widely influenced by waves and/or currents interpreted to represent impact-generated tsunamis, and S1 and S2 show multiple graded layers indicating the passage of two or more wave trains. These tsunamis may have promoted mixing within a globally stratified ocean, enriching surface waters in nutrients for biological communities. S2 and S3 mark the transition from the 300-million-year-long Onverwacht stage of predominantly basaltic and komatiitic volcanism to the late orogenic stage of greenstone belt evolution, suggesting that regional and possibly global tectonic reorganization resulted from these large impacts. These beds provide the oldest known direct record of terrestrial impacts and an opportunity to explore their influence on early life, crust, ocean, and atmosphere. The apparent presence of impact clusters at 3.26-3.24 Ga and approximately 2.65-2.5 Ga suggests either spikes in impact rates during the Archean or that the entire Archean was characterized by terrestrial impact rates above those currently estimated from the lunar cratering record.

  1. Spherule Beds 3.47-3.24 Billion Years Old in the Barberton Greenstone Belt, South Africa: A Record of Large Meteorite Impacts and Their Influence on Early Crustal and Biological Evolution

    NASA Technical Reports Server (NTRS)

    Lowe, Donald R.; Byerly, Gary R.; Kyte, Frank T.; Shukolyukov, Alexander; Asaro, Frank; Krull, Alexander

    2003-01-01

    Four layers, S1-S4, containing sand-sized spherical particles formed as a result of large meteorite impacts, occur in 3.47-3.24 Ga rocks of the Barberton Greenstone Belt, South Africa. Ir levels in S3 and S4 locally equal or exceed chondritic values but in other sections are at or only slightly above background. Most spherules are inferred to have formed by condensation of impact-produced rock vapor clouds, although some may represent ballistically ejected liquid droplets. Extreme Ir abundances and heterogeneity may reflect element fractionation during spherule formation, hydraulic fractionation during deposition, and/or diagenetic and metasomatic processes. Deposition of S1, S2, and S3 was widely influenced by waves and/or currents interpreted to represent impact-generated tsunamis, and S1 and S2 show multiple graded layers indicating the passage of two or more wave trains. These tsunamis may have promoted mixing within a globally stratified ocean, enriching surface waters in nutrients for biological communities. S2 and S3 mark the transition from the 300-million-year-long Onverwacht stage of predominantly basaltic and komatiitic volcanism to the late orogenic stage of greenstone belt evolution, suggesting that regional and possibly global tectonic reorganization resulted from these large impacts. These beds provide the oldest known direct record of terrestrial impacts and an opportunity to explore their influence on early life, crust, ocean, and atmosphere. The apparent presence of impact clusters at 3.26-3.24 Ga and approx. 2.65-2.5 Ga suggests either spikes in impact rates during the Archean or that the entire Archean was characterized by terrestrial impact rates above those currently estimated from the lunar cratering record.

  2. $1.2 Billion Investment Needed in 2017 to Implement CCDBG Reauthorization

    ERIC Educational Resources Information Center

    Center for Law and Social Policy, Inc. (CLASP), 2016

    2016-01-01

    The Child Care and Development Block Grant (CCDBG) is the primary source of federal funding for child care subsidies for low-income families and to improve child care quality for all children. Quality child care enables parents to work or go to school while providing children with safe and enriching environments where they can learn and thrive.…

  3. The updated billion-ton resource assessment

    SciTech Connect

    Turhollow, Anthony; Perlack, Robert; Eaton, Laurence; Langholtz, Matthew; Brandt, Craig; Downing, Mark; Wright, Lynn; Skog, Kenneth; Hellwinckel, Chad; Stokes, Bryce; Lebow, Patricia

    2014-10-03

    This paper summarizes the results of an update to a resource assessment, published in 2005, commonly referred to as the billion-ton study (BTS). The updated results are consistent with the 2005 BTS in terms of overall magnitude. However, in looking at the major categories of feedstocks the forest residue biomass potential was determined to be less owing to tighter restrictions on forest residue supply including restrictions due to limited projected increase in traditional harvest for pulpwood and sawlogs. The crop residue potential was also determined to be less because of the consideration of soil carbon and not allowing residue removal from conventionally tilled corn acres. The energy crop potential was estimated to be much greater largely because of land availability and modeling of competition among various competing uses of the land. Generally, the scenario assumptions in the updated assessment are much more plausible to show a billion-ton resource, which would be sufficient to displace 30% or more of the country s present petroleum consumption.

  4. The updated billion-ton resource assessment

    DOE PAGES

    Turhollow, Anthony; Perlack, Robert; Eaton, Laurence; ...

    2014-10-03

    This paper summarizes the results of an update to a resource assessment, published in 2005, commonly referred to as the billion-ton study (BTS). The updated results are consistent with the 2005 BTS in terms of overall magnitude. However, in looking at the major categories of feedstocks the forest residue biomass potential was determined to be less owing to tighter restrictions on forest residue supply including restrictions due to limited projected increase in traditional harvest for pulpwood and sawlogs. The crop residue potential was also determined to be less because of the consideration of soil carbon and not allowing residue removalmore » from conventionally tilled corn acres. The energy crop potential was estimated to be much greater largely because of land availability and modeling of competition among various competing uses of the land. Generally, the scenario assumptions in the updated assessment are much more plausible to show a billion-ton resource, which would be sufficient to displace 30% or more of the country s present petroleum consumption.« less

  5. The Yatela gold deposit: 2 billion years in the making

    NASA Astrophysics Data System (ADS)

    Hein, K. A. A.; Matsheka, I. R.; Bruguier, O.; Masurel, Q.; Bosch, D.; Caby, R.; Monié, P.

    2015-12-01

    Gold mineralisation in the Yatela Main gold mine is hosted in a saprolitic residuum situated above Birimian supracrustal rocks, and at depth. The supracrustal rocks comprise metamorphosed calcitic and dolomitic marbles that were intruded by diorite (2106 ± 10 Ma, 207Pb/206Pb), and sandstone-siltstone-shale sequences (youngest detrital zircon population dated at 2139 ± 6 Ma). In-situ gold-sulphide mineralisation is associated with hydrothermal activity synchronous to emplacement of the diorite and forms a sub-economic resource; however, the overlying saprolitic residuum hosts economic gold mineralisation in friable lateritized palaeosols and aeolian sands (loess). Samples of saprolitic residuum were studied to investigate the morphology and composition of gold grains as a proxy for distance from source (and possible exploration vector) because the deposit hosts both angular and detrital gold suggesting both proximal and distal sources. U-Pb geochronology of detrital zircons also indicated a proximal and distal source, with the age spectra giving Archaean (2.83-3.28 Ga), and Palaeoproterozoic (1.95-2.20 Ga) to Neoproterozoic (1.1-1.8 Ga) zircons in the Yatela depocentre. The 1.1-1.8 Ga age spectrum restricts the maximum age for the first deposition of the sedimentary units in the Neoproterozoic, or during early deposition in the Taoudeni Basin. Models for formation of the residuum include distal and proximal sources for detritus into the depocentre, however, it is more likely that material was sourced locally and included recycled material. The creation of a deep laterite weathering profile and supergene enrichment of the residuum probably took place during the mid-Cretaceous-early Tertiary.

  6. Gamma-Ray Blazars within the First 2 Billion Years

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Becerra Gonzalez, J.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Bregeon, J.; Bruel, P.; Buehler, R.; Buson, S.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Cheung, C. C.; Chiang, J.; Chiaro, G.; Ciprini, S.; Conrad, J.; Costantin, D.; Costanza, F.; Cutini, S.; D’Ammando, F.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Lalla, N.; Di Mauro, M.; Di Venere, L.; Domínguez, A.; Drell, P. S.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Finke, J.; Focke, W. B.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giordano, F.; Giroletti, M.; Green, D.; Grenier, I. A.; Guillemot, L.; Guiriec, S.; Hartmann, D. H.; Hays, E.; Horan, D.; Jogler, T.; Jóhannesson, G.; Johnson, A. S.; Kuss, M.; La Mura, G.; Larsson, S.; Latronico, L.; Li, J.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Magill, J. D.; Maldera, S.; Manfreda, A.; Marcotulli, L.; Mazziotta, M. N.; Michelson, P. F.; Mirabal, N.; Mitthumsiri, W.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Negro, M.; Nuss, E.; Ohsugi, T.; Ojha, R.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paliya, V. S.; Paneque, D.; Perkins, J. S.; Persic, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Principe, G.; Rainò, S.; Rando, R.; Rani, B.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Romani, R. W.; Sgrò, C.; Simone, D.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Stalin, C. S.; Stawarz, L.; Suson, D. J.; Takahashi, M.; Tanaka, K.; Thayer, J. B.; Thompson, D. J.; Torres, D. F.; Torresi, E.; Tosti, G.; Troja, E.; Vianello, G.; Wood, K. S.

    2017-03-01

    The detection of high-redshift (z > 3) blazars enables the study of the evolution of the most luminous relativistic jets over cosmic time. More importantly, high-redshift blazars tend to host massive black holes and can be used to constrain the space density of heavy black holes in the early universe. Here, we report the first detection with the Fermi-Large Area Telescope of five γ-ray-emitting blazars beyond z = 3.1, more distant than any blazars previously detected in γ-rays. Among these five objects, NVSS J151002+570243 is now the most distant known γ-ray-emitting blazar at z = 4.31. These objects have steeply falling γ-ray spectral energy distributions (SEDs), and those that have been observed in X-rays have a very hard X-ray spectrum, both typical of powerful blazars. Their Compton dominance (ratio of the inverse Compton to synchrotron peak luminosities) is also very large (> 20). All of these properties place these objects among the most extreme members of the blazar population. Their optical spectra and the modeling of their optical-UV SEDs confirm that these objects harbor massive black holes ({M}{BH}∼ {10}8-10 {M}ȯ ). We find that, at z≈ 4, the space density of > {10}9 {M}ȯ black holes hosted in radio-loud and radio-quiet active galactic nuclei are similar, implying that radio-loudness may play a key role in rapid black hole growth in the early universe.

  7. The Growth of Galaxies over the last 12 Billion Years

    NASA Astrophysics Data System (ADS)

    Mosleh, M.

    2016-09-01

    One of the key unsolved problems in astrophysics is to understand the formation and evolution of galaxies. There are many complementary approaches to study the evolution of galaxies and infer how distant galaxies are connected to galaxies in the present day universe. These canonical ways are either focused on the evolution of luminosity/mass function, star formation rate density, or the evolution of the observed scaling relations of galaxies. Among the scaling relations, the relation between the stellar mass and sizes of galaxies has considerable importance. Evidence is provided by many recent studies that the size of galaxies were smaller at higher redshifts compared to galaxies of similar mass in the local Universe. Studying these galaxy properties at different epochs can place important constrains on the underlying processes assumed for the galaxy mass and structural evolution. I will present the study of the mass-size evolution of galaxies from redshift z=7 to z=1 and the stellar mass-size relation for nearby galaxies (z=0). Also, I will present the stellar mass assembly history of quiescent and star-forming galaxies between z=2 and z=0.5, by studying the radial mass profile of these galaxies.

  8. Scoping design analyses for optimized shipping casks containing 1-, 2-, 3-, 5-, 7-, or 10-year-old PWR spent fuel

    SciTech Connect

    Bucholz, J.A.

    1983-01-01

    This report details many of the interrelated considerations involved in optimizing large Pb, Fe, or U-metal spent fuel shipping casks containing 1, 2, 3, 5, 7, or 10-year-old PWR fuel assemblies. Scoping analyses based on criticality, shielding, and heat transfer considerations indicate that some casks may be able to hold as many as 18 to 21 ten-year-old PWR fuel assemblies. In the criticality section, a new type of inherently subcritical fuel assembly separator is described which uses hollow, borated stainless-steel tubes in the wall-forming structure between the assemblies. In another section, details of many n/..gamma.. shielding optimization studies are presented, including the optimal n/..gamma.. design points and the actual shielding requirements for each type of cask as a function of the age of the spent fuel and the number of assemblies in the cask. Multigroup source terms based on ORIGEN2 calculations at these and other decay times are also included. Lastly, the numerical methods and experimental correlations used in the steady-state and transient heat transfer analyses are fully documented, as are pertinent aspects of the SCOPE code for Shipping Cask Optimization and Parametric Evaluation. (While only casks for square, intact PWR fuel assemblies were considered in this study, the SCOPE code may also be used to design and analyze casks containing canistered spent fuel or other waste material. An abbreviated input data guide is included as an appendix).

  9. Simulating Billion-Task Parallel Programs

    SciTech Connect

    Perumalla, Kalyan S; Park, Alfred J

    2014-01-01

    In simulating large parallel systems, bottom-up approaches exercise detailed hardware models with effects from simplified software models or traces, whereas top-down approaches evaluate the timing and functionality of detailed software models over coarse hardware models. Here, we focus on the top-down approach and significantly advance the scale of the simulated parallel programs. Via the direct execution technique combined with parallel discrete event simulation, we stretch the limits of the top-down approach by simulating message passing interface (MPI) programs with millions of tasks. Using a timing-validated benchmark application, a proof-of-concept scaling level is achieved to over 0.22 billion virtual MPI processes on 216,000 cores of a Cray XT5 supercomputer, representing one of the largest direct execution simulations to date, combined with a multiplexing ratio of 1024 simulated tasks per real task.

  10. Four-Year Maintenance Treatment With Adalimumab in Patients with Moderately to Severely Active Ulcerative Colitis: Data from ULTRA 1, 2, and 3

    PubMed Central

    Colombel, Jean-Frederic; Sandborn, William J; Ghosh, Subrata; Wolf, Douglas C; Panaccione, Remo; Feagan, Brian; Reinisch, Walter; Robinson, Anne M; Lazar, Andreas; Kron, Martina; Huang, Bidan; Skup, Martha; Thakkar, Roopal B

    2014-01-01

    OBJECTIVES: The safety and efficacy of adalimumab for patients with moderately to severely active ulcerative colitis (UC) has been reported up to week 52 from the placebo-controlled trials ULTRA (Ulcerative Colitis Long-Term Remission and Maintenance with Adalimumab) 1 and 2. Up to 4 years of data for adalimumab-treated patients from ULTRA 1, 2, and the open-label extension ULTRA 3 are presented. METHODS: Remission per partial Mayo score, remission per Inflammatory Bowel Disease Questionnaire (IBDQ) score, and mucosal healing rates were assessed in adalimumab-randomized patients from ULTRA 1 and 2 up to week 208. Corticosteroid-free remission was assessed in adalimumab-randomized patients who used corticosteroids at lead-in study baseline. Maintenance of remission per partial Mayo score and mucosal healing was assessed in patients who entered ULTRA 3 in remission per full Mayo score and with mucosal healing, respectively. As observed, last observation carried forward (LOCF) and nonresponder imputation (NRI) were used to report efficacy. Adverse events were reported for any adalimumab-treated patient. RESULTS: A total of 600/1,094 patients enrolled in ULTRA 1 or 2 were randomized to receive adalimumab and included in the intent-to-treat analyses of the studies. Of these, 199 patients remained on adalimumab after 4 years of follow-up. Rates of remission per partial Mayo score, remission per IBDQ score, mucosal healing, and corticosteroid discontinuation at week 208 were 24.7%, 26.3%, 27.7% (NRI), and 59.2% (observed), respectively. Of the patients who were followed up in ULTRA 3 (588/1,094), a total of 360 patients remained on adalimumab 3 years later. Remission per partial Mayo score and mucosal healing after ULTRA 1 or 2 to year 3 of ULTRA 3 were maintained by 63.6% and 59.9% of patients, respectively (NRI). Adverse event rates were stable over time. CONCLUSIONS: Remission, mucosal healing, and improved quality of life were maintained in patients with moderately to

  11. Time to remission for eating disorder patients: a 2(1/2)-year follow-up study of outcome and predictors.

    PubMed

    Clausen, Loa

    2008-01-01

    The aim of the present study was to analyse outcome, time to remission, and predictors of time to remission in a cohort of Danish eating disorder patients. Seventy-eight patients (35 anorexic, 30 bulimic and 13 unspecified eating disorder patients) were interviewed 2(1/2) years after initial assessment. Method of assessment was Eating Disorder Examination (EDE), Longitudinal Interval Follow-up Evaluation of Eating Disorders (LIFE-EAT-II), Eating Disorder Inventory (EDI), Symptom Check List (SCL-90R), Present State Examination (PSE) and the Structured Clinical Interview for DSM-III-R Axis-II (SCID-II). Method of analysis was Kaplan-Meier estimate of survival, Log Rank test and Cox regression analysis. In total 48.7% reached remission with mean time to remission at 27 months. A trend difference between the diagnostic groups when measuring time to remission was found, i.e. patients with unspecified eating disorders remitted faster than bulimic (BN) patients who in turn remitted faster than anorexic (AN) patients. Body mass index (BMI) at baseline was the best predictor of time to remission for the total sample. Predictors differed when looking at diagnostic groups separately. Final outcome was comparable with earlier studies while relapse frequency was low. Patients with AN remitted faster than found in earlier survival analysis studies, while the remission rate for BN patients was comparable with earlier studies. Despite the prognostic value of BMI for the total sample, predictor analysis implied more disorder diversity than homogeneity.

  12. Uranium in Canada: A billion dollar industry

    SciTech Connect

    Ruzicka, V. )

    1989-12-01

    In 1988, Canada maintained its position as the world's leading producer of uranium with an output of more than 12,400 MT of uranium in concentrates, worth $1.1 billion Canadian. As domestic requirements represent only 15% of current Canadian production, most of the output was exported. With current implementation of the Canada/US Free Trade Agreement, the US has become Canada's major uranium export customer. With a large share of the world's known uranium resources, Canada remains the focus of international uranium exploration activity. In 1988, the uranium exploration expenditures in Canada exceeded $58 million Canadian. The principal exploration targets were deposits associated with Proterozoic unconformities in Saskatchewan and Northwest Territories, particularly those in the Athabasca and Thelon basin regions of the Canadian Shield. Major attention was also paid to polymetallic deposits in which uranium is associated with precious metals, such as gold and platinum group elements. Conceptual genetic models for these deposit types represent useful tools to guide exploration.

  13. Agroecohydrology: Key to Feeding 9 Billion?

    NASA Astrophysics Data System (ADS)

    Herrick, J.

    2011-12-01

    Agricultural production necessary to feed 9 billion people in 2050 depends on increased production on existing croplands, and expanding onto 'marginal' lands. A high proportion of these lands are marginal because they are too steep or too dry to reliably support crop production. These same characteristics increase their susceptibility to accelerated erosion, leading (for most soil profiles) to further reductions in plant available water as infiltration and soil profile water holding capacity decline. Sustaining production on these marginal lands will require careful land use planning. In this paper, we present a land use planning framework that integrates 4 elements: (1) potential production (based on soil profile characteristics), (2) edaphic, topographic and climatic limitations to production, (3) soil resistance to degradation, and (4) resilience. This framework expands existing land capability classification systems through the integration of biophysical feedbacks and thresholds. State and transition models, similar to those currently applied to rangelands in the United States and other countries, are used to organize and communicate knowledge about the sustainability of different land use changes and management actions at field to regional scales. This framework emphasizes hydrologic characteristics of soil profiles and landscapes over fertility because fertility declines are more easily addressed through increased inputs. The presentation will conclude with a discussion of how research in ecohydrology can be more effectively focused to support sustainable food production in the context of increasingly rapid social and economic changes throughout the world.

  14. LLNL's Big Science Capabilities Help Spur Over $796 Billion in U.S. Economic Activity Sequencing the Human Genome

    SciTech Connect

    Stewart, Jeffrey S.

    2015-07-28

    LLNL’s successful history of taking on big science projects spans beyond national security and has helped create billions of dollars per year in new economic activity. One example is LLNL’s role in helping sequence the human genome. Over $796 billion in new economic activity in over half a dozen fields has been documented since LLNL successfully completed this Grand Challenge.

  15. An ultraluminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30.

    PubMed

    Wu, Xue-Bing; Wang, Feige; Fan, Xiaohui; Yi, Weimin; Zuo, Wenwen; Bian, Fuyan; Jiang, Linhua; McGreer, Ian D; Wang, Ran; Yang, Jinyi; Yang, Qian; Thompson, David; Beletsky, Yuri

    2015-02-26

    So far, roughly 40 quasars with redshifts greater than z = 6 have been discovered. Each quasar contains a black hole with a mass of about one billion solar masses (10(9) M Sun symbol). The existence of such black holes when the Universe was less than one billion years old presents substantial challenges to theories of the formation and growth of black holes and the coevolution of black holes and galaxies. Here we report the discovery of an ultraluminous quasar, SDSS J010013.02+280225.8, at redshift z = 6.30. It has an optical and near-infrared luminosity a few times greater than those of previously known z > 6 quasars. On the basis of the deep absorption trough on the blue side of the Lyman-α emission line in the spectrum, we estimate the proper size of the ionized proximity zone associated with the quasar to be about 26 million light years, larger than found with other z > 6.1 quasars with lower luminosities. We estimate (on the basis of a near-infrared spectrum) that the black hole has a mass of ∼1.2 × 10(10) M Sun symbol, which is consistent with the 1.3 × 10(10) M Sun symbol derived by assuming an Eddington-limited accretion rate.

  16. Expert fears doom if world population hits 12-15 billion.

    PubMed

    1994-02-22

    Earth's land, water and cropland are disappearing so rapidly that the world population must be slashed to 2 billion or less by 2100 to provide prosperity for all in that year, says a study released yesterday. The alternative, if current trends continue, is a population of 12 billion to 15 billion people and an apocalyptic worldwide scene of "absolute misery, poverty, disease and starvation," said the study's author, David Pimentel, an ecologist at Cornell University. In the US, the population would climb to 500 million and the standard of living would decline to slightly better than in present-day China. Mr. Pimentel said at the annual meeting of the American Association for the Advancement of Science. Even now, the world population of 6 billion is at least 3 times what the Earth's battered natural resources and depleted energy reserves would be able to comfortably support in 2100, Mr. Pimentel said. Mr. Pimentel defines "comfortably support" as providing something close to the current American standard of living, but with wiser use of energy and natural resources. Although a decline to 1 billion or 2 billion people over the next century sounds nearly impossible, it could be done by limiting families around the world to an average of 1.5 children, Mr. Pimentel said. Currently, US women have an average of 2.1 children, while the average in Rwanda is 8.5.

  17. Well servicing boom pushes costs over $3 billion

    SciTech Connect

    Not Available

    1981-07-01

    Results of the Annual Petroleum Engineer Well Servicing Survey are presented. The most significant change in well servicing trends was reduced abandonments - the number of abandoned wells dropped from 9011 in 1979 to 3021 in 1980. For the second year in a row, producers will spend more than $3 billion for well services. Well servicing operators performed nearly 568,000 servicing and repair jobs on 734,728 operating wells in the US during 1980. In addition, 71,000 wells were completed or recompleted in 1980. Tables of data are summarized for completion, workover, and servicing activities and for servicing operations for 11 individual US regions, including Appalachia, California on shore/off shore, Four Corners, Great Lakes, Gulf of Mexico, Louisiana (on shore), mid-continent, Rocky-Williston, Texas (on shore, includes SE New Mexico), and the southeast. The US total data exclude wells in Alaska.

  18. Sneak Peek to the 2016 Billion-Ton Report

    SciTech Connect

    2016-06-01

    The 2005 Billion-Ton Study became a landmark resource for bioenergy stakeholders, detailing for the first time the potential to produce at least one billion dry tons of biomass annually in a sustainable manner from U.S. agriculture and forest resources. The 2011 U.S. Billion-Ton Update expanded and updated the analysis, and in 2016, the U.S. Department of Energy’s Bioenergy Technologies Office plans to release the 2016 Billion-Ton Report: Advancing Domestic Resources for a Thriving Bioeconomy.

  19. Billions for biodefense: federal agency biodefense funding, FY2001-FY2005.

    PubMed

    Schuler, Ari

    2004-01-01

    Over the past several years, the United States government has spent substantial resources on preparing the nation against a bioterrorist attack. This article analyzes the civilian biodefense funding by the federal government from fiscal years 2001 through 2005, specifically analyzing the budgets and allocations for biodefense at the Department of Health and Human Services, the Department of Homeland Security, the Department of Defense, the Department of Agriculture, the Environmental Protection Agency, the National Science Foundation, and the Department of State. In total, approximately $14.5 billion has been funded for civilian biodefense through FY2004, with an additional $7.6 billion in the President's budget request for FY2005.

  20. Regional Feedstock Partnership Summary Report: Enabling the Billion-Ton Vision

    SciTech Connect

    Owens, Vance N.; Karlen, Douglas L.; Lacey, Jeffrey A.

    2016-07-12

    The U.S. Department of Energy (DOE) and the Sun Grant Initiative established the Regional Feedstock Partnership (referred to as the Partnership) to address information gaps associated with enabling the vision of a sustainable, reliable, billion-ton U.S. bioenergy industry by the year 2030 (i.e., the Billion-Ton Vision). Over the past 7 years (2008–2014), the Partnership has been successful at advancing the biomass feedstock production industry in the United States, with notable accomplishments. The Billion-Ton Study identifies the technical potential to expand domestic biomass production to offset up to 30% of U.S. petroleum consumption, while continuing to meet demands for food, feed, fiber, and export. This study verifies for the biofuels and chemical industries that a real and substantial resource base could justify the significant investment needed to develop robust conversion technologies and commercial-scale facilities. DOE and the Sun Grant Initiative established the Partnership to demonstrate and validate the underlying assumptions underpinning the Billion-Ton Vision to supply a sustainable and reliable source of lignocellulosic feedstock to a large-scale bioenergy industry. This report discusses the accomplishments of the Partnership, with references to accompanying scientific publications. These accomplishments include advances in sustainable feedstock production, feedstock yield, yield stability and stand persistence, energy crop commercialization readiness, information transfer, assessment of the economic impacts of achieving the Billion-Ton Vision, and the impact of feedstock species and environment conditions on feedstock quality characteristics.

  1. How to Bring Solar Energy to Seven Billion People (LBNL Science at the Theater)

    ScienceCinema

    Wadia, Cyrus

    2016-07-12

    By exploiting the powers of nanotechnology and taking advantage of non-toxic, Earth-abundant materials, Berkeley Lab's Cyrus Wadia has fabricated new solar cell devices that have the potential to be several orders of magnitude less expensive than conventional solar cells. And by mastering the chemistry of these materials-and the economics of solar energy-he envisions bringing electricity to the 1.2 billion people now living without it.

  2. Predictors (0-10 Months) of Psychopathology at Age 1 1/2 Years--A General Population Study in the Copenhagen Child Cohort CCC 2000

    ERIC Educational Resources Information Center

    Skovgaard, A. M.; Olsen, E. M.; Christiansen, E.; Houmann, T.; Landorph, S. L.; Jorgensen, T.

    2008-01-01

    Background: Epidemiological studies of mental health problems in the first years of life are few. This study aims to investigate infancy predictors of psychopathology in the second year of life. Methods: A random general population sample of 210 children from the Copenhagen Child Birth Cohort CCC 2000 was investigated by data from National Danish…

  3. Universities Report $1.8-Billion in Earnings on Inventions in 2011

    ERIC Educational Resources Information Center

    Blumenstyk, Goldie

    2012-01-01

    Universities and their inventors earned more than $1.8-billion from commercializing their academic research in the 2011 fiscal year, collecting royalties from new breeds of wheat, from a new drug for the treatment of HIV, and from longstanding arrangements over enduring products like Gatorade. Northwestern University earned the most of any…

  4. Diet and environment 1.2 million years ago revealed through analysis of dental calculus from Europe's oldest hominin at Sima del Elefante, Spain.

    PubMed

    Hardy, Karen; Radini, Anita; Buckley, Stephen; Blasco, Ruth; Copeland, Les; Burjachs, Francesc; Girbal, Josep; Yll, Riker; Carbonell, Eudald; Bermúdez de Castro, Jose María

    2017-02-01

    Sima del Elefante, Atapuerca, Spain contains one of the earliest hominin fragments yet known in Europe, dating to 1.2 Ma. Dental calculus from a hominin molar was removed, degraded and analysed to recover entrapped remains. Evidence for plant use at this time is very limited and this study has revealed the earliest direct evidence for foods consumed in the genus Homo. This comprises starchy carbohydrates from two plants, including a species of grass from the Triticeae or Bromideae tribe, meat and plant fibres. All food was eaten raw, and there is no evidence for processing of the starch granules which are intact and undamaged. Additional biographical detail includes fragments of non-edible wood found adjacent to an interproximal groove suggesting oral hygiene activities, while plant fibres may be linked to raw material processing. Environmental evidence comprises spores, insect fragments and conifer pollen grains which are consistent with a forested environment.

  5. Diet and environment 1.2 million years ago revealed through analysis of dental calculus from Europe's oldest hominin at Sima del Elefante, Spain

    NASA Astrophysics Data System (ADS)

    Hardy, Karen; Radini, Anita; Buckley, Stephen; Blasco, Ruth; Copeland, Les; Burjachs, Francesc; Girbal, Josep; Yll, Riker; Carbonell, Eudald; Bermúdez de Castro, Jose María

    2017-02-01

    Sima del Elefante, Atapuerca, Spain contains one of the earliest hominin fragments yet known in Europe, dating to 1.2 Ma. Dental calculus from a hominin molar was removed, degraded and analysed to recover entrapped remains. Evidence for plant use at this time is very limited and this study has revealed the earliest direct evidence for foods consumed in the genus Homo. This comprises starchy carbohydrates from two plants, including a species of grass from the Triticeae or Bromideae tribe, meat and plant fibres. All food was eaten raw, and there is no evidence for processing of the starch granules which are intact and undamaged. Additional biographical detail includes fragments of non-edible wood found adjacent to an interproximal groove suggesting oral hygiene activities, while plant fibres may be linked to raw material processing. Environmental evidence comprises spores, insect fragments and conifer pollen grains which are consistent with a forested environment.

  6. Effect of recombinant human growth hormone on changes in height, bone mineral density, and body composition over 1-2 years in children with Hurler or Hunter syndrome.

    PubMed

    Polgreen, Lynda E; Thomas, William; Orchard, Paul J; Whitley, Chester B; Miller, Bradley S

    2014-02-01

    Patients with Hurler or Hunter syndrome typically have moderate to severe growth deficiencies despite therapy with allogeneic hematopoietic stem cell transplantation and/or enzyme replacement therapy. It is unknown whether treatment with recombinant human growth hormone (hGH) can improve growth in these children. The objectives of this study were to determine the effects of hGH on growth, bone mineral density (BMD), and body composition in children with Hurler or Hunter syndrome enrolled in a longitudinal observational study. The difference in annual change in outcomes between hGH treated and untreated subjects was estimated by longitudinal regression models that adjusted for age, Tanner stage, and sex where appropriate. We report on 23 participants who completed at least 2 annual study visits (10 [43%] treated with hGH): Hurler syndrome (n=13) average age of 9.8 ± 3.1 years (range 5.3-13.6 years; 54% female) and Hunter syndrome (n=10) average age of 12.0 ± 2.7 years (range 7.0-17.0 years; 0% female). As a group, children with Hurler or Hunter syndrome treated with hGH had no difference in annual change in height (growth velocity) compared to those untreated with hGH. Growth velocity in hGH treated individuals ranged from -0.4 to 8.1cm/year and from 0.3 to 6.6 cm/year in the untreated individuals. Among children with Hunter syndrome, 100% (N=4) of those treated but only 50% of those untreated with hGH had an annual increase in height standard deviation score (SDS). Of the individuals treated with hGH, those with GHD had a trend towards higher annualized growth velocity compared to those without GHD (6.5 ± 1.9 cm/year vs. 3.5 ± 2.1cm/year; p=.050). Children treated with hGH had greater annual gains in BMD and lean body mass. In conclusion, although as a group we found no significant difference in growth between individuals treated versus not treated with hGH, individual response was highly variable and we are unable to predict who will respond to treatment. Thus

  7. EPA Survey Shows $271 Billion Needed for Nations Wastewater Infrastructure

    EPA Pesticide Factsheets

    WASHINGTON - The U.S. Environmental Protection Agency (EPA) today released a survey showing that $271 billion is needed to maintain and improve the nation's wastewater infrastructure, including the pipes that carry wastewater to treatment plants, th

  8. Harnessing Energy from the Sun for Six Billion People

    ScienceCinema

    Daniel Nocera

    2016-07-12

    Daniel Nocera, a Massachusetts Institute of Technology professor whose recent research focuses on solar-powered fuels, presents a Brookhaven Science Associates Distinguished Lecture, titled "Harnessing Energy from the Sun for Six Billion People -- One at a Time."

  9. NASA Now Minute: Earth and Space Science: 100 Billion Planets

    NASA Video Gallery

    Stephen Kane, co-author of the article, “Study Shows Our Galaxy has 100Billion Planets” reveals details about this incredible study explainsjust how common planets are in our Milky Way galaxy...

  10. Academic Pork Barrel Tops $2-Billion for the First Time.

    ERIC Educational Resources Information Center

    Brainard, Jeffrey; Borrego, Anne Marie

    2003-01-01

    Describes how, despite the growing budget deficit, Congress directed a record $2 billion to college projects in 2003, many of them dealing with security and bioterrorism. Includes data tables on the earmarks. (EV)

  11. Summary and Comparison of the 2016 Billion-Ton Report with the 2011 U.S. Billion-Ton Update

    SciTech Connect

    2016-06-01

    In terms of the magnitude of the resource potential, the results of the 2016 Billion-Ton Report (BT16) are consistent with the original 2005 Billion-Ton Study (BTS) and the 2011 report, U.S. Billion-Ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry (BT2. An effort was made to reevaluate the potential forestland, agricultural, and waste resources at the roadside, then extend the analysis by adding transportation costs to a biorefinery under specified logistics assumptions to major resource fractions.

  12. White Nail Radio Transmitter: Billion Dollar Savings through Energy Efficiency

    DTIC Science & Technology

    2011-05-10

    energy consumption ashore by 50 percent CNO, Navy Energy Vision, P 10 White Nail Vision Your Cell Phone Cell ...Greenhouse Gas Power 4 1 Energy Navy Use 7.3 Billion kWh White Nail Cell Phone Savings 11 Billion kWh One and a half times!!! Saves the output of four of...Estimated Total Number of transmitters 3,000,000 Estimated total power saved Watt 1,250,000,000 Cell Phone Transmitter Efficiency 1.25 Gigawatts

  13. Breast and ovarian cancer screening of non-carriers from BRCA1/2 mutation-positive families: 2-year follow-up of cohorts from France and Quebec

    PubMed Central

    Dorval, Michel; Noguès, Catherine; Berthet, Pascaline; Chiquette, Jocelyne; Gauthier-Villars, Marion; Lasset, Christine; Picard, Claude; Plante, Marie; Simard, Jacques; Julian-Reynier, Claire

    2011-01-01

    We described and compared breast and ovarian screening practices in the 2-year period following test result disclosure in female non-carriers from BRCA1/2 mutation-positive families living in two countries, France and Quebec, Canada, which provide universal health care. Four hundred and two (France n=293; Quebec n=109) unaffected female non-carriers from BRCA-proven mutation families provided information about the uptake of mammography, clinical breast examination, breast self-examination, and ovarian ultrasounds using self-administered questionnaires. The frequency of screening practices between study cohorts were compared using logistic regression. Annual mammography was conducted in 23 and 43% of French and Quebecer women participants <50 years of age, respectively (adjusted odds ratio (aOR)=2.72; 95% confidence interval (CI), 1.08–6.81). In women ≥50 years of age, mammography was conducted in 49 and 65% of French and Quebecer participants (aOR=1.77; 95% CI, 0.07–4.51). Overall, 33% of French women and 39% of Quebecer women underwent at least one ovarian ultrasound during the 2-year period following BRCA1/2 test result with no significant difference between cohorts of women <50 years of age. Among older women, Quebecers reported more frequently than French women that they had undergone ultrasound once (aOR=3.00; 95% CI, 1.02–8.83). The frequency of cancer screening practices for female non-carriers from BRCA1/2 mutation-positive families in both France and Quebec exceeded those recommended for similarly aged women in the general population. Our findings highlight the need for clearcut recommendations on the follow-up of women from BRCA1/2 families who are not themselves carriers of a BRCA1/2 mutation. PMID:21248744

  14. The uncertain timing of reaching 8 billion, peak world population, and other demographic milestones.

    PubMed

    Scherbov, Sergei; Lutz, Wolfgang Lutz; Sanderson, Warren C

    2011-01-01

    We present new probabilistic forecasts of the timing of the world's population reaching 8 billion, the world's peak population, and the date at which one-third or more of the world's population would be 60+ years old. The timing of these milestones, as well as the timing of the Day of 7 Billion, is uncertain. We compute that the 60 percent prediction interval for the Day of 8 Billion is between 2024 and 2033. Our figures show that there is around a 60 percent chance that one-third of the world's population would be 60+ years old in 2100. In the UN 2010 medium variant, that proportion never reaches one-third. As in our past forecasts (Lutz et al. 2001, 2008), we find the chance that the world's population will peak in this century to be around 84 percent and the timing of that peak to be highly uncertain. Focal days, like the Day of 7 Billion, play a role in raising public awareness of population issues, but they give a false sense of the certainty of our knowledge. The uncertainty of the timing of demographic milestones is not a constant of nature. Understanding the true extent of our demographic uncertainty can help motivate governments and other agencies to make the investments necessary to reduce it.

  15. N zooming into the Mediterranean outflow fossil moat during the 1.2-1.8 million years period (Early-Pleistocene) - An approach by radiogenic and stable isotopes

    NASA Astrophysics Data System (ADS)

    Lebreiro, Susana M.; Antón, Laura; Reguera, M. Isabel; Fernández, Marta; Conde, Estefanía; Barrado, Ana I.; Yllera, Abel

    2015-12-01

    The fossil Alvarez Cabral erosive Moat contains hemipelagite, contourite and turbidite facies where oceanography changes in the Mediterranean outflow are archived over the 1.2-1.8 Myr time period. Here we used Pb and Sr radiogenic isotopes to trace water masses and sediment source changes, for the first time in twenty glacial-interglacial (G-I) cycles of the Early-Pleistocene interval, and the last Glacial Maximum through Holocene cycle (including the Younger Dryas and Heinrich Stadial-1). A mixing line of Pb isotopes gives reliable low radiogenic 208Pb/204Pb, 206Pb/204Pb, and 206Pb/207Pb typical of Mediterranean Outflow Water (MOW) in one end-member and the signature of high radiogenic isotopes of Atlantic Waters (AW) towards the second end-member. The 87Sr/86Sr isotopes also display two end-members of the mixing line between eolian transport/dust source (0.71) and fluvial transport/weathering source (0.73) previously proposed in the Gulf of Cadiz. Combination of Pb and Sr radiogenic isotopes with O and C stable isotopes of planktonic and benthic foraminifera, and the response of foraminifera benthos over the Early-Pleistocene interval, reveals a direct link between water masses circulation and shifts in G-I. We found a persistent cyclic pattern of MOW circulation and fluvial deposition during glaciations and AW and aeolian influence during interglaciations. On site U1386B/C, the upper-MOW was less ventilated but productive and with high flux of organic flux matter during glacials, while Atlantic Waters were better ventilated, enriched in O, but less productive during interglacials. We infer that shifts in ocean and atmospheric processes in the Gulf of Cadiz were strongly controlled by Earth's obliquity (41 kyr-cycle) and 35°NH insolation during the Early-Pleistocene. We propose a correlation in changes in phase-relationship between precession and obliquity. In general terms, physical properties of fine sediments (glacials) show lower NGR, low reflectance and

  16. Large $N$ approach to kaon decays and mixing 28 years later: $\\Delta I = 1/2$ rule, $\\hat B_K$ and $\\Delta M_K$

    SciTech Connect

    Buras, Andrzej J.; Gérard, Jean -Marc; Bardeen, William A.

    2014-05-20

    We review and update our results for K → π π decays and K⁰- K¯⁰ mixing obtained by us in the 1980s within an approach based on the dual representation of QCD as a theory of weakly interacting mesons for large N colours. In our analytic approach the dynamics behind the enhancement of ReA0 and suppression of ReA2, the so-called ΔI = 1/2 rule for K → π π decays, has a simple structure: the usual octet enhancement through quark-gluon renormalization group evolution down to the scales O(1 GeV) is continued as a meson evolution down to zero momentum scales at which the factorization of hadronic matrix elements is at work. The inclusion of lowest-lying vector meson contributions in addition to the pseudoscalar ones and of Wilson coefficients in a momentum scheme improves significantly the matching between quark-gluon and meson evolutions. In particular, the anomalous dimension matrix governing the meson evolution exhibits the structure of the known anomalous dimension matrix in the quark-gluon evolution. The recent results on ReA2 and ReA0 from the RBC-UKQC collaboration give support for our approach. In particular, the signs of the two main contractions found numerically by these authors follow uniquely from our analytic approach. At NLO in 1/N we obtain R = ReA0/ReA2= 16.0±1.5 which amounts to an order of magnitude enhancement over the strict large N limit value √2. QCD penguins contribute at 15% level to this result. We also find B^K = 0.73± 0.02, with the smallness of 1/N corrections to the large N value B^K = 3/4 resulting within our approach from an approximate cancellation between pseudoscalar and vector meson one-loop contributions. We summarize the status of ΔMK in this approach.

  17. Large $N$ approach to kaon decays and mixing 28 years later: $$\\Delta I = 1/2$$ rule, $$\\hat B_K$$ and $$\\Delta M_K$$

    DOE PAGES

    Buras, Andrzej J.; Gérard, Jean -Marc; Bardeen, William A.

    2014-05-20

    We review and update our results for K → π π decays and K⁰- K¯⁰ mixing obtained by us in the 1980s within an approach based on the dual representation of QCD as a theory of weakly interacting mesons for large N colours. In our analytic approach the dynamics behind the enhancement of ReA0 and suppression of ReA2, the so-called ΔI = 1/2 rule for K → π π decays, has a simple structure: the usual octet enhancement through quark-gluon renormalization group evolution down to the scales O(1 GeV) is continued as a meson evolution down to zero momentum scalesmore » at which the factorization of hadronic matrix elements is at work. The inclusion of lowest-lying vector meson contributions in addition to the pseudoscalar ones and of Wilson coefficients in a momentum scheme improves significantly the matching between quark-gluon and meson evolutions. In particular, the anomalous dimension matrix governing the meson evolution exhibits the structure of the known anomalous dimension matrix in the quark-gluon evolution. The recent results on ReA2 and ReA0 from the RBC-UKQC collaboration give support for our approach. In particular, the signs of the two main contractions found numerically by these authors follow uniquely from our analytic approach. At NLO in 1/N we obtain R = ReA0/ReA2= 16.0±1.5 which amounts to an order of magnitude enhancement over the strict large N limit value √2. QCD penguins contribute at 15% level to this result. We also find B^K = 0.73± 0.02, with the smallness of 1/N corrections to the large N value B^K = 3/4 resulting within our approach from an approximate cancellation between pseudoscalar and vector meson one-loop contributions. We summarize the status of ΔMK in this approach.« less

  18. Two years' experience of implementing molecular screening of hepatitis B virus, hepatitis C virus and human immunodeficiency virus 1, 2 in Riyadh blood donors.

    PubMed

    Mohamud, Hanat S; Mohamed, Deqa H; Alqahtani, Farjah H; Almajid, Fahad M; Alswat, Khalid; Somily, Ali M

    2016-04-01

    Molecular screening technologies have improved blood safety by reducing the number of window-period transmissions relative to serological screening. In the two years following the introduction of molecular testing in King Khalid University Hospital, Saudi Arabia, 25,920 donor samples were screened in parallel by both serological and molecular techniques for hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV). No HCV or HIV NAT yields were detected. However, molecular screening enabled the interdiction of two confirmed HBV NAT yields. This is only the second report of confirmed HBV NAT yield in the Kingdom of Saudi Arabia, and amongst the few reports in the wider Middle East and North Africa region.

  19. [Protective special shoes for diabetics. Personal experience with a group of high risk diabetics during a 2 and 1/2 year period].

    PubMed

    Záhumenský, E; Adamíková, A

    1993-09-01

    A group of 60 type II diabetics with the risk of development of ulceration of the feet was provided with protective specialized footwear. In the course of 2.5 years in 45 patients who could be evaluated the frequency of relapses of previous ulcerations, the development of first ulcerations and the effect on indicators of immediate high risk of a defect (formation of decubital ulcers, blisters) was investigated, as well as the general biomechanical comfort. In 10 patients with relapsing defects relapses developed twice (20%), no primary ulceration developed. As compared with common footwear, the protective footwear had a favourable effect on the formation of sores and blisters 25 patients (55.5%/ 45/100%) reported improvement of the general comfort when walking. 28 (62.2%) patients make use of the favourable experience with the specialized footwear when selecting shoes or when modifiying standard footwear. A surprising finding was delayed fatigue when walking reported by 35 (77.8%) patients, mitigation of dysaesthesias by 23 (51%), pain in the joints by 14 (31.1%), improved stability by 35 (77.8%) of the patients. With regard of the improvement of some subjective complaints the use of protective footwear can be considered a symptomatic-therapeutic element. According to clinical results specialized footwear has a favourable and protective effect on already damaged feet with a reduced tolerance for combined (mechanical, ischaemic, neurotrophic, infectious) insults. Consistent with data of authors from abroad after a 2-5-year follow-up there was a cca 50% reduction in the number of relapses of ulcerations and amputations as compared with common not modified footwear.

  20. Multi-Billion Shot, High-Fluence Exposure of Cr(4+): YAG Passive Q-Switch

    NASA Technical Reports Server (NTRS)

    Stephen, Mark A.; Dallas, Joseph L.; Afzal, Robert S.

    1997-01-01

    NASA's Goddard Space Flight Center is developing the Geoscience Laser Altimeter System (GLAS) employing a diode pumped, Q-Switched, ND:YAG laser operating at 40 Hz repetition rate. To meet the five-year mission lifetime goal, a single transmitter would accumulate over 6.3 billion shots. Cr(4+):YAG is a promising candidate material for passively Q-switching the laser. Historically, the performance of saturable absorbers has degraded over long-duration usage. To measure the multi-billion shot performance of Cr(4+):YAG, a passively Q-switched GLAS-like oscillator was tested at an accelerated repetition rate of 500 Hz. The intracavity fluence was calculated to be approximately 2.5 J/cm(exp 2). The laser was monitored autonomously for 165 days. There was no evidence of change in the material optical properties during the 7.2 billion shot test.. All observed changes in laser operation could be attributed to pump laser diode aging. This is the first demonstration of multi-billion shot exposure testing of Cr(4+):YAG in this pulse energy regime

  1. Winglets Save Billions of Dollars in Fuel Costs

    NASA Technical Reports Server (NTRS)

    2010-01-01

    The upturned ends now featured on many airplane wings are saving airlines billions of dollars in fuel costs. Called winglets, the drag-reducing technology was advanced through the research of Langley Research Center engineer Richard Whitcomb and through flight tests conducted at Dryden Flight Research Center. Seattle-based Aviation Partners Boeing -- a partnership between Aviation Partners Inc., of Seattle, and The Boeing Company, of Chicago -- manufactures Blended Winglets, a unique design featured on Boeing aircraft around the world. These winglets have saved more than 2 billion gallons of jet fuel to date, representing a cost savings of more than $4 billion and a reduction of almost 21.5 million tons in carbon dioxide emissions.

  2. Billions for biodefense: federal agency biodefense funding, FY2009-FY2010.

    PubMed

    Franco, Crystal

    2009-09-01

    Since 2001, the United States government has spent substantial resources on preparing the nation against a bioterrorist attack. Earlier articles in this series analyzed civilian biodefense funding by the federal government for fiscal years (FY) 2001 through 2009. This article updates those figures with budgeted amounts for FY2010, specifically analyzing the budgets and allocations for biodefense at the Departments of Health and Human Services, Defense, Homeland Security, Agriculture, and State; the Environmental Protection Agency; and the National Science Foundation. This year's article also provides an assessment of the proportion of the biodefense budget that serves multiple programmatic goals and benefits, including research into infectious disease pathogenesis and immunology, public health planning and preparedness, and disaster response efforts. The FY2010 federal budget for civilian biodefense totals $6.05 billion. Of that total, $4.96 billion is budgeted for programs that serve multiple goals and provide manifold benefits.

  3. Medicare, Medicaid fraud a billion-dollar art form in the US

    PubMed Central

    Korcok, M

    1997-01-01

    Medicare and Medicaid fraud costs billions of dollars each year in the US. Investigators have shown that fraud is found in all segments of the health care system. Even though the Canadian system has stricter regulations and tighter controls, can regulators here afford to be complacent about believing that such abuse would not happen here? One province has established an antifraud unit to monitor its health insurance scheme; it already has 1 prosecution under its belt. PMID:9141996

  4. Bill and Melinda Gates Pledge $1-Billion for Minority Scholarships.

    ERIC Educational Resources Information Center

    Monaghan, Peter; Lederman, Douglas; van der Werf, Martin; Pulley, John

    1999-01-01

    Reports on a $1 billion dollar grant from Bill and Melinda Gates to send 20,000 low-income minority students to college. The Gates Millenium Scholars Program will require students to demonstrate financial need and maintain a 3.0 grade point average in college. A list of the largest private gifts to higher education since 1967 is also provided. (DB)

  5. Skeptics Say Billions for Education Won't Stimulate Economy

    ERIC Educational Resources Information Center

    Field, Kelly

    2009-01-01

    Skeptics question whether infusion of billions of dollars for education in the economic-stimulus bill before Congress would actually give a healthy jolt to the economy. The bill would help thousands of students pay for college and could give colleges money to fix crumbling buildings. Some members of Congress are calling for the removal of…

  6. Four laser companies to exceed $1 billion revenue in 2016

    NASA Astrophysics Data System (ADS)

    Thoss, Andreas F.

    2017-02-01

    It seems very likely that for first time four companies will exceed the revenue of 1 billion in 2016. This comes along with substantial changes in the market for lasers and laser systems. The article analyzes some of the changes and looks at the individual success strategies of the major players in these markets.

  7. Planet Earth 2025. A look into a future world of 8 billion humans.

    PubMed

    Hinrichsen, D; Rowley, J

    1999-01-01

    Population projections for the next quarter century are reasonably predictable, and related resource challenges are quite visible. The world's population is expected to grow to around 8 billion by 2025. According to the International Food Policy Research Institute, if current levels of investments in agriculture and social welfare continue, food grain production will increase by about 1.5% and livestock production by 2.7% a year over the next 2 decades. These levels are much lower now compared to previous decades, and population could outstrip supply unless there is a big increase in developing country imports. The continued destruction of the earth's forest mantle as a result of human activities is another desperate concern. By 2025, some 3 billion people will live in land-short countries and another 2 billion will be living in urban areas with high levels of air pollution. In addition, coastal ecosystems, which are already exposed to unbridled coastal development and mounting pollution loads, will experience more pressures as the number of people living near them increases in the next 25 years. One final challenge is the unprecedented rate of habitat loss and species extinction. Ecosystem destruction is so severe that as many as 60,000 plant species could be lost by the year 2025.

  8. President Carter signs $227 billion excise tax measure

    SciTech Connect

    Miller, C.J.; McAfee, J.; Dibona, C.J.; Carter, J.

    1980-04-07

    According to President J. Carter, who signed into law a $227 billion excise tax (windfall profits tax) on revenue from decontrolled U.S. crude oil production, the new tax program will provide the U.S. with the incentive and the means to produce and conserve domestic oil and replace more oil with alternative sources of energy. According to C. DiBona (API), the new tax will discourage the increased amount of domestic production required to compensate, by the mid-to-late 1980's, for a 1.7 million bbl/day shortfall, which will have to be made up with imports from foreign producers. According to J. McAfee of Gulf Oil Corp., only a token amount, about $34 billion of the $227 billion which will be raised by the new tax over the next decade, will be devoted to energy development and mass transit. According to C. J. Miller of the Independent Petroleum Association of America, the tax's complex and sometimes conflicting regulations will pose harsh problems for smaller producers.

  9. A 17-billion-solar-mass black hole in a group galaxy with a diffuse core.

    PubMed

    Thomas, Jens; Ma, Chung-Pei; McConnell, Nicholas J; Greene, Jenny E; Blakeslee, John P; Janish, Ryan

    2016-04-21

    Quasars are associated with and powered by the accretion of material onto massive black holes; the detection of highly luminous quasars with redshifts greater than z = 6 suggests that black holes of up to ten billion solar masses already existed 13 billion years ago. Two possible present-day 'dormant' descendants of this population of 'active' black holes have been found in the galaxies NGC 3842 and NGC 4889 at the centres of the Leo and Coma galaxy clusters, which together form the central region of the Great Wall--the largest local structure of galaxies. The most luminous quasars, however, are not confined to such high-density regions of the early Universe; yet dormant black holes of this high mass have not yet been found outside of modern-day rich clusters. Here we report observations of the stellar velocity distribution in the galaxy NGC 1600--a relatively isolated elliptical galaxy near the centre of a galaxy group at a distance of 64 megaparsecs from Earth. We use orbit superposition models to determine that the black hole at the centre of NGC 1600 has a mass of 17 billion solar masses. The spatial distribution of stars near the centre of NGC 1600 is rather diffuse. We find that the region of depleted stellar density in the cores of massive elliptical galaxies extends over the same radius as the gravitational sphere of influence of the central black holes, and interpret this as the dynamical imprint of the black holes.

  10. Severe Obesity In Adults Cost State Medicaid Programs Nearly $8 Billion In 2013.

    PubMed

    Wang, Y Claire; Pamplin, John; Long, Michael W; Ward, Zachary J; Gortmaker, Steven L; Andreyeva, Tatiana

    2015-11-01

    Efforts to expand Medicaid while controlling spending must be informed by a deeper understanding of the extent to which the high medical costs associated with severe obesity (having a body mass index of [Formula: see text] or higher) determine spending at the state level. Our analysis of population-representative data indicates that in 2013, severe obesity cost the nation approximately $69 billion, which accounted for 60 percent of total obesity-related costs. Approximately 11 percent of the cost of severe obesity was paid for by Medicaid, 30 percent by Medicare and other federal health programs, 27 percent by private health plans, and 30 percent out of pocket. Overall, severe obesity cost state Medicaid programs almost $8 billion a year, ranging from $5 million in Wyoming to $1.3 billion in California. These costs are likely to increase following Medicaid expansion and enhanced coverage of weight loss therapies in the form of nutrition consultation, drug therapy, and bariatric surgery. Ensuring and expanding Medicaid-eligible populations' access to cost-effective treatment for severe obesity should be part of each state's strategy to mitigate rising obesity-related health care costs.

  11. 1,2-Diphenylhydrazine

    Integrated Risk Information System (IRIS)

    1,2 - Diphenylhydrazine ; CASRN 122 - 66 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcin

  12. 1,2-Dibromoethane

    Integrated Risk Information System (IRIS)

    EPA 635 / R - 04 / 067 www.epa.gov / iris TOXICOLOGICAL REVIEW OF 1,2 - DIBROMOETHANE ( CAS No . 106 - 93 - 4 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) June 2004 U.S . Environmental Protection Agency Washington , DC DISCLAIMER This document has been revie

  13. 1,2-Dichloropropane

    Integrated Risk Information System (IRIS)

    1,2 - Dichloropropane ; CASRN 78 - 87 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

  14. 1,2-Dichlorobenzene

    Integrated Risk Information System (IRIS)

    1,2 - Dichlorobenzene ; CASRN 95 - 50 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

  15. 1,2-Dichloroethane

    Integrated Risk Information System (IRIS)

    1,2 - Dichloroethane ; CASRN 107 - 06 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

  16. Scalable in-memory RDFS closure on billions of triples.

    SciTech Connect

    Goodman, Eric L.; Mizell, David

    2010-06-01

    We present an RDFS closure algorithm, specifically designed and implemented on the Cray XMT supercomputer, that obtains inference rates of 13 million inferences per second on the largest system configuration we used. The Cray XMT, with its large global memory (4TB for our experiments), permits the construction of a conceptually straightforward algorithm, fundamentally a series of operations on a shared hash table. Each thread is given a partition of triple data to process, a dedicated copy of the ontology to apply to the data, and a reference to the hash table into which it inserts inferred triples. The global nature of the hash table allows the algorithm to avoid a common obstacle for distributed memory machines: the creation of duplicate triples. On LUBM data sets ranging between 1.3 billion and 5.3 billion triples, we obtain nearly linear speedup except for two portions: file I/O, which can be ameliorated with the additional service nodes, and data structure initialization, which requires nearly constant time for runs involving 32 processors or more.

  17. Ultrarelativistic heavy ion collisions: the first billion seconds

    NASA Astrophysics Data System (ADS)

    Baym, Gordon

    2016-12-01

    I first review the early history of the ultrarelativistic heavy ion program, starting with the 1974 Bear Mountain Workshop, and the 1983 Aurora meeting of the U.S. Nuclear Science Committtee, just one billion seconds ago, which laid out the initial science goals of an ultrarelativistic collider. The primary goal, to discover the properties of nuclear matter at the highest energy densities, included finding new states of matter - the quark-gluon plasma primarily - and to use collisions to open a new window on related problems of matter in cosmology, neutron stars, supernovae, and elsewhere. To bring out how the study of heavy ions and hot, dense matter in QCD has been fulfilling these goals, I concentrate on a few topics, the phase diagram of matter in QCD, and connections of heavy ion physics to cold atoms, cosmology, and neutron stars.

  18. Fast scalable visualization techniques for interactive billion-particle walkthrough

    NASA Astrophysics Data System (ADS)

    Liu, Xinlian

    This research develops a comprehensive framework for interactive walkthrough involving one billion particles in an immersive virtual environment to enable interrogative visualization of large atomistic simulation data. As a mixture of scientific and engineering approaches, the framework is based on four key techniques: adaptive data compression based on space-filling curves, octree-based visibility and occlusion culling, predictive caching based on machine learning, and scalable data reduction based on parallel and distributed processing. In terms of parallel rendering, this system combines functional parallelism, data parallelism, and temporal parallelism to improve interactivity. The visualization framework will be applicable not only to material simulation, but also to computational biology, applied mathematics, mechanical engineering, and nanotechnology, etc.

  19. Bigger, Better Catalog Unveils Half a Billion Celestial Objects

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These frames are samples from the photographic sky surveys, which have been digitized by a technical team at the Space Telescope Science Institute to support the Hubble Space Telescope operations. The team processed these images to create a new astronomical catalog, called the Guide Star Catalog II. This project was undertaken by the Space Telescope Science Institute as an upgrade to an earlier sky survey and catalog (DSS-I and GSC-I), initially done to provide guide stars for pointing the Hubble Space Telescope. By virtue of its sheer size, the DSS-II and GSC-II have many research applications for both professional and amateur astronomers. [Top] An example from the DSS-II shows the Rosette Nebula, (originally photographed by the Palomar Observatory) as digitized in the DSS-I (left) and DSS-II (right). The DSS-II includes views of the sky at both red and blue wavelengths, providing invaluable color information on about one billion deep-sky objects. [Bottom] This blow-up of the inset box in the raw DSS-I scan shows examples of the GSC-I and the improved GSC-II catalogs. Astronomers extracted the stars from the scanned plate of the Rosette and listed them in the catalogs. The new GSC-II catalog provides the colors, positions, and luminosities of nearly half a billion stars -- over 20 times as many as the original GSC-I. The GSC-II contains information on stars as dim as the 19th magnitude. Credit: NASA, the DSS-II and GSC-II Consortia (with images from the Palomar Observatory-STScI Digital Sky Survey of the northern sky, based on scans of the Second Palomar Sky Survey are copyright c 1993-1999 by the California Institute of Technology)

  20. A 17-billion-solar-mass black hole in a group galaxy with a diffuse core

    NASA Astrophysics Data System (ADS)

    Thomas, Jens; Ma, Chung-Pei; McConnell, Nicholas J.; Greene, Jenny E.; Blakeslee, John P.; Janish, Ryan

    2016-04-01

    Quasars are associated with and powered by the accretion of material onto massive black holes; the detection of highly luminous quasars with redshifts greater than z = 6 suggests that black holes of up to ten billion solar masses already existed 13 billion years ago. Two possible present-day ‘dormant’ descendants of this population of ‘active’ black holes have been found in the galaxies NGC 3842 and NGC 4889 at the centres of the Leo and Coma galaxy clusters, which together form the central region of the Great Wall—the largest local structure of galaxies. The most luminous quasars, however, are not confined to such high-density regions of the early Universe; yet dormant black holes of this high mass have not yet been found outside of modern-day rich clusters. Here we report observations of the stellar velocity distribution in the galaxy NGC 1600—a relatively isolated elliptical galaxy near the centre of a galaxy group at a distance of 64 megaparsecs from Earth. We use orbit superposition models to determine that the black hole at the centre of NGC 1600 has a mass of 17 billion solar masses. The spatial distribution of stars near the centre of NGC 1600 is rather diffuse. We find that the region of depleted stellar density in the cores of massive elliptical galaxies extends over the same radius as the gravitational sphere of influence of the central black holes, and interpret this as the dynamical imprint of the black holes.

  1. $75 Billion in Formula Grants Failed to Drive Reform. Can $5 Billion in Competitive Grants Do the Job? Education Stimulus Watch. Special Report 2

    ERIC Educational Resources Information Center

    Smarick, Andy

    2009-01-01

    In early 2009, Congress passed and President Barack Obama signed into law the American Recovery and Reinvestment Act (ARRA), the federal government's nearly $800 billion stimulus legislation. According to key members of Congress and the Obama administration, the education portions of the law, totaling about $100 billion, were designed both to…

  2. Parametrization and Classification of 20 Billion LSST Objects: Lessons from SDSS

    SciTech Connect

    Ivezic, Z.; Axelrod, T.; Becker, A.C.; Becla, J.; Borne, K.; Burke, David L.; Claver, C.F.; Cook, K.H.; Connolly, A.; Gilmore, D.K.; Jones, R.L.; Juric, M.; Kahn, Steven M.; Lim, K-T.; Lupton, R.H.; Monet, D.G.; Pinto, P.A.; Sesar, B.; Stubbs, Christopher W.; Tyson, J.Anthony; /UC, Davis

    2011-11-10

    The Large Synoptic Survey Telescope (LSST) will be a large, wide-field ground-based system designed to obtain, starting in 2015, multiple images of the sky that is visible from Cerro Pachon in Northern Chile. About 90% of the observing time will be devoted to a deep-wide-fast survey mode which will observe a 20,000 deg{sup 2} region about 1000 times during the anticipated 10 years of operations (distributed over six bands, ugrizy). Each 30-second long visit will deliver 5{sigma} depth for point sources of r {approx} 24.5 on average. The co-added map will be about 3 magnitudes deeper, and will include 10 billion galaxies and a similar number of stars. We discuss various measurements that will be automatically performed for these 20 billion sources, and how they can be used for classification and determination of source physical and other properties. We provide a few classification examples based on SDSS data, such as color classification of stars, color-spatial proximity search for wide-angle binary stars, orbital-color classification of asteroid families, and the recognition of main Galaxy components based on the distribution of stars in the position-metallicity-kinematics space. Guided by these examples, we anticipate that two grand classification challenges for LSST will be (1) rapid and robust classification of sources detected in difference images, and (2) simultaneous treatment of diverse astrometric and photometric time series measurements for an unprecedentedly large number of objects.

  3. Fuel efficient stoves for the poorest two billion

    NASA Astrophysics Data System (ADS)

    Gadgil, Ashok

    2012-03-01

    About 2 billion people cook their daily meals on generally inefficient, polluting, biomass cookstoves. The fuels include twigs and leaves, agricultural waste, animal dung, firewood, and charcoal. Exposure to resulting smoke leads to acute respiratory illness, and cancers, particularly among women cooks, and their infant children near them. Resulting annual mortality estimate is almost 2 million deaths, higher than that from malaria or tuberculosis. There is a large diversity of cooking methods (baking, boiling, long simmers, brazing and roasting), and a diversity of pot shapes and sizes in which the cooking is undertaken. Fuel-efficiency and emissions depend on the tending of the fire (and thermal power), type of fuel, stove characteristics, and fit of the pot to the stove. Thus, no one perfect fuel-efficient low-emitting stove can suit all users. Affordability imposes a further severe constraint on the stove design. For various economic strata within the users, a variety of stove designs may be appropriate and affordable. In some regions, biomass is harvested non-renewably for cooking fuel. There is also increasing evidence that black carbon emitted from stoves is a significant contributor to atmospheric forcing. Thus improved biomass stoves can also help mitigate global climate change. The speaker will describe specific work undertaken to design, develop, test, and disseminate affordable fuel-efficient stoves for internally displaced persons (IDPs) of Darfur, Sudan, where the IDPs face hardship, humiliation, hunger, and risk of sexual assault owing to their dependence on local biomass for cooking their meals.

  4. The continuing cost of privatization: extra payments to Medicare Advantage plans jump to $11.4 billion in 2009.

    PubMed

    Biles, Brian; Pozen, Jonah; Guterman, Stuart

    2009-05-01

    The Medicare Modernization Act of 2003 explicitly increased Medicare payments to private Medicare Advantage (MA) plans. As a result, MA plans have, for the past six years, been paid more for their enrollees than they would be expected to cost in traditional fee-for-service Medicare. Payments to MA plans in 2009 are projected to be 13 percent greater than the corresponding costs in traditional Medicare--an average of $1,138 per MA plan enrollee, for a total of $11.4 billion. Although the extra payments are used to provide enrollees additional benefits, those benefits are not available to all beneficiaries-- but they are financed by general program funds. If payments to MA plans were instead equal to the spending level under traditional Medicare, the more than $150 billion in savings over 10 years could be used to finance improved benefits for the low-income elderly and disabled, or for expanding health-insurance coverage.

  5. Vizualization Challenges of a Subduction Simulation Using One Billion Markers

    NASA Astrophysics Data System (ADS)

    Rudolph, M. L.; Gerya, T. V.; Yuen, D. A.

    2004-12-01

    Recent advances in supercomputing technology have permitted us to study the multiscale, multicomponent fluid dynamics of subduction zones at unprecedented resolutions down to about the length of a football field. We have performed numerical simulations using one billion tracers over a grid of about 80 thousand points in two dimensions. These runs have been performed using a thermal-chemical simulation that accounts for hydration and partial melting in the thermal, mechanical, petrological, and rheological domains. From these runs, we have observed several geophysically interesting phenomena including the development of plumes with unmixed mantle composition as well as plumes with mixed mantle/crust components. Unmixed plumes form at depths greater than 100km (5-10 km above the upper interface of subducting slab) and consist of partially molten wet peridotite. Mixed plumes form at lesser depth directly from the subducting slab and contain partially molten hydrated oceanic crust and sediments. These high resolution simulations have also spurred the development of new visualization methods. We have created a new web-based interface to data from our subduction simulation and other high-resolution 2D data that uses an hierarchical data format to achieve response times of less than one second when accessing data files on the order of 3GB. This interface, WEB-IS4, uses a Javascript and HTML frontend coupled with a C and PHP backend and allows the user to perform region of interest zooming, real-time colormap selection, and can return relevant statistics relating to the data in the region of interest.

  6. Plutonium-244 fission tracks - Evidence in a lunar rock 3.95 billion years old.

    NASA Technical Reports Server (NTRS)

    Hutcheon, I. D.; Price, P. B.

    1972-01-01

    Tracks attributed to the spontaneous fission of plutonium-244 and of uranium-238 were detected in a large whitlockite crystal in the lunar breccia 14321 from the Fra Mauro formation. For a track-retention age of 3.95 b.y., the number of plutonium tracks relative to the number of uranium tracks is 0.51 plus or minus 0.15, provided that the rock was not heavily neutron-irradiated 3.95 b.y. ago.

  7. The rapid formation of a large rotating disk galaxy three billion years after the Big Bang.

    PubMed

    Genzel, R; Tacconi, L J; Eisenhauer, F; Schreiber, N M Förster; Cimatti, A; Daddi, E; Bouché, N; Davies, R; Lehnert, M D; Lutz, D; Nesvadba, N; Verma, A; Abuter, R; Shapiro, K; Sternberg, A; Renzini, A; Kong, X; Arimoto, N; Mignoli, M

    2006-08-17

    Observations and theoretical simulations have established a framework for galaxy formation and evolution in the young Universe. Galaxies formed as baryonic gas cooled at the centres of collapsing dark-matter haloes; mergers of haloes and galaxies then led to the hierarchical build-up of galaxy mass. It remains unclear, however, over what timescales galaxies were assembled and when and how bulges and disks--the primary components of present-day galaxies--were formed. It is also puzzling that the most massive galaxies were more abundant and were forming stars more rapidly at early epochs than expected from models. Here we report high-angular-resolution observations of a representative luminous star-forming galaxy when the Universe was only 20% of its current age. A large and massive rotating protodisk is channelling gas towards a growing central stellar bulge hosting an accreting massive black hole. The high surface densities of gas, the high rate of star formation and the moderately young stellar ages suggest rapid assembly, fragmentation and conversion to stars of an initially very gas-rich protodisk, with no obvious evidence for a major merger.

  8. A high abundance of massive galaxies 3-6 billion years after the Big Bang.

    PubMed

    Glazebrook, Karl; Abraham, Roberto G; McCarthy, Patrick J; Savaglio, Sandra; Chen, Hsiao-Wen; Crampton, David; Murowinski, Rick; Jørgensen, Inger; Roth, Kathy; Hook, Isobel; Marzke, Ronald O; Carlberg, R G

    2004-07-08

    Hierarchical galaxy formation is the model whereby massive galaxies form from an assembly of smaller units. The most massive objects therefore form last. The model succeeds in describing the clustering of galaxies, but the evolutionary history of massive galaxies, as revealed by their visible stars and gas, is not accurately predicted. Near-infrared observations (which allow us to measure the stellar masses of high-redshift galaxies) and deep multi-colour images indicate that a large fraction of the stars in massive galaxies form in the first 5 Gyr (refs 4-7), but uncertainties remain owing to the lack of spectra to confirm the redshifts (which are estimated from the colours) and the role of obscuration by dust. Here we report the results of a spectroscopic redshift survey that probes the most massive and quiescent galaxies back to an era only 3 Gyr after the Big Bang. We find that at least two-thirds of massive galaxies have appeared since this era, but also that a significant fraction of them are already in place in the early Universe.

  9. Detection of pristine gas two billion years after the Big Bang.

    PubMed

    Fumagalli, Michele; O'Meara, John M; Prochaska, J Xavier

    2011-12-02

    In the current cosmological model, only the three lightest elements were created in the first few minutes after the Big Bang; all other elements were produced later in stars. To date, however, heavy elements have been observed in all astrophysical environments. We report the detection of two gas clouds with no discernible elements heavier than hydrogen. These systems exhibit the lowest heavy-element abundance in the early universe, and thus are potential fuel for the most metal-poor halo stars. The detection of deuterium in one system at the level predicted by primordial nucleosynthesis provides a direct confirmation of the standard cosmological model. The composition of these clouds further implies that the transport of heavy elements from galaxies to their surroundings is highly inhomogeneous.

  10. Gunshot Wounds Cost U.S. Hospitals Nearly $7 Billion Over 9 Years

    MedlinePlus

    ... in the United States, there's little research on gun violence from a public health perspective. Part of ... passed in 1996 that restricts federal funding for firearms research, Spitzer said. "Firearm injuries are tied to ...

  11. Oxidative Weathering of Earth's Surface 3.7 Billion Years ago? - A Chromium Isotope Perspective

    NASA Astrophysics Data System (ADS)

    Frei, R.; Crowe, S.; Bau, M.; Polat, A.; Fowle, D. A.; Døssing, L. N.

    2015-12-01

    The Great Oxidation Event signals the first large-scale oxygenation of the atmosphere roughly 2.4 Gyr ago. Geochemical signals diagnostic of oxidative weathering, however, extend as far back as 3.3-2.9 Gyr ago. 3.8-3.7 Gyr old rocks from Isua, Greenland stand as a deep time outpost, recording information on Earth's earliest surface chemistry and the low oxygen primordial biosphere. We find positive Cr isotope values (average δ53Cr = +0.05 +/- 0.10 permil; δ53Cr = (53Cr/52Cr)sample/(53Cr/52Cr)SRM 979 - 1) x 1000, where SRM 979 denotes Standard Reference Material 979 in both the Fe and Si-rich mesobands of 7 compositionally distinct quartz-magnetite and magnesian banded iron formation (BIF) samples collected from the eastern portion of the Isua BIF (Western Greenland). These postively fractioned Cr isotopes, relative to the igneous silicate Earth reservoir, in metamorphosed BIFs from Isua indicate oxidative Cr cycling 3.8-3.7 Gyr ago. We also examined the distribution of U, which is immobile in its reduced state but mobile when it is oxidized. Elevated U/Th ratios (mean U/Th ratio of 0.70 ± 0.29) in these BIFs relative to the contemporary crust, also signal oxidative mobilization of U. We suggest that reactive oxygen species (ROS) accumulated in Earth's surface environment inducing the oxidative weathering of rocks during the deposition of the Isua BIFs. The precise threshold atmospheric O2 concentrations for the induction of Cr isotope fractionation remain uncertain, but we argue that our data are consistent with the very low levels of oxygen or other ROS indicated by other proxies. Importantly, any trace of Cr that cycled through redox reactions on land would tend both to be heavy, and to mobilize into the contemporaneous run-off more readily than Cr weathered directly as Cr(III). Once having reached the oceans, this fractionated Cr would have been stripped from seawater by Fe (oxy)hydroxides formed during the deposition of BIFs from low oxygen oceans. The reactive oxygen species recorded in Isua sediments may also have been sufficient to support aerobic metabolisms, which are known to occur in extant bacteria at oxygen concentrations as low as 10-8 atm.

  12. Atmospheric carbon dioxide concentrations before 2.2 billion years ago.

    PubMed

    Rye, R; Kuo, P H; Holland, H D

    1995-12-07

    The composition of the Earth's early atmosphere is a subject of continuing debate. In particular, it has been suggested that elevated concentrations of atmospheric carbon dioxide would have been necessary to maintain normal surface temperatures in the face of lower solar luminosity in early Earth history. Fossil weathering profiles, known as palaeosols, have provided semi-quantitative constraints on atmospheric oxygen partial pressure (pO2) before 2.2 Gyr ago. Here we use the same well studied palaeosols to constrain atmospheric pCO2 between 2.75 and 2.2 Gyr ago. The observation that iron lost from the tops of these profiles was reprecipitated lower down as iron silicate minerals, rather than as iron carbonate, indicates that atmospheric pCO2 must have been less than 10(-1.4) atm--about 100 times today's level of 360 p.p.m., and at least five times lower than that required in one-dimensional climate models to compensate for lower solar luminosity at 2.75 Gyr. Our results suggest that either the Earth's early climate was much more sensitive to increases in pCO2 than has been thought, or that one or more greenhouse gases other than CO2 contributed significantly to the atmosphere's radiative balance during the late Archaean and early Proterozoic eons.

  13. The Stability Of Disk Barred Galaxies Over the Past 7 Billion Years

    NASA Astrophysics Data System (ADS)

    Tapia, Amauri; Simmons, Brooke

    2017-01-01

    A recently released model of interacting disk galaxies provides a hypothesis for the origins of off center bars in disks. No systematic search for offset bars in the early universe has yet been undertaken. The Galaxy Zoo project has produced data regarding the large-scale bars of many galaxies. Using this data alongside images collected by the Hubble Space Telescope and other sources, we have examined 5190 galaxies for signatures of off-centered bars. Less than 5 percent of the sample shows clear signs of an offset bar. We describe their overall properties of this sub-sample and compare the properties of galaxies with offset bars to those with centered bars. We assess the feasibility of the proposed model and place these galaxies in the context of the overall evolution of galaxies.

  14. Survival Of Pure Disc Galaxies Over The Last 8 Billion Years

    NASA Astrophysics Data System (ADS)

    Sachdeva, Sonali

    2016-09-01

    The presence of pure disk galaxies without any bulge component, i.e., neither classical nor pseudo, poses a severe challenge not just to the hierarchical galaxy formation models but also to the theories of internal secular evolution. We discover that a significant fraction of disk galaxies ( 15-18 %) in the Hubble Deep Field (0.4 < z < 1.0) as well as in the local Universe (0.02 < z < 0.05) are such pure disk systems (PDS). We trace the evolution of this population to find how they survived the merger violence and other disk instabilities to remain dynamically undisturbed. We find that smooth accretion of cold gas via cosmic filaments is the most probable mode of their growth in mass and size since z 1. We speculate that PDSs are dynamically hotter and cushioned in massive dark matter haloes which may prevent them from undergoing strong secular evolution.

  15. Using MeerKAT to study HI in galaxies over nine billion years of cosmic time

    NASA Astrophysics Data System (ADS)

    Baker, Andrew

    2015-08-01

    Understanding the evolution of cold gas in galaxies is a critical element of understanding their overall evolution. Existing (sub)millimeter facilities have made it possible to study the molecular component of galaxies' ISMs over wide ranges in redshift, but studying their atomic gas content through the HI line has only been possible over a very limited range in lookback time. In this presentation, I will describe South Africa's new SKA precursor array, MeerKAT, and an approved 5000 hour deep field survey (Looking At the Distant Universe with the MeerKAT Array = LADUMA) that will probe the HI content of galaxies out to z = 1.4. Using a combination of direct and stacked detections, LADUMA will examine the evolution of the baryonic Tully-Fisher relation, the HI mass function, and the cosmic HI density over ranges of cosmic time that have been inaccessible to us up to now.

  16. The Buildup of Passive Galaxies in Clusters and the Field Over the Last 7 Billion Years.

    NASA Astrophysics Data System (ADS)

    Rudnick, Gregory; van der Wel, A.; Moustakas, J.; Jablonka, P.

    2011-01-01

    One of galaxy evolution's most long-standing problems is determining how clusters affect the properties of infalling galaxies. One useful metric for this is how quickly the passive galaxy population in clusters assembles over time. Standard practice has been to assume that all red sequence galaxies are passive and to measure the evolution in the red fraction and red sequence luminosity function over time. This approach, however, neglects the possible contribution of dusty galaxies to the red sequence, which can be significant at intermediate environment and low to intermediate stellar masses. We move beyond a simple red sequence cut by using a new multi-color technique to distinguish red passive galaxies from red dusty star-forming galaxies. Isolating passive galaxies is inherently more physical than studying galaxies selected on one color alone. We track the buildup of passive galaxies in the field and in clusters using the COSMOS data for the former and a large imaging and spectroscopy survey of intermediate redshift clusters for the latter. The fraction of passive galaxies in clusters increases with increasing galaxy mass, increasing cluster velocity dispersion, and with time at a fixed mass and velocity dispersion. We relate the passive fraction in clusters to that for field galaxies of similar masses and use this to constrain the processes that shut off star formation in infalling cluster galaxies. The fraction of dust-obscured star forming galaxies changes with stellar mass and environment and this affects the interpretation of the rapid evolution in the faint red sequence galaxy population and its environmental dependence, as seen in other works.

  17. A Powerful Toolkit for Synthetic Biology: Over 3.8 Billion Years of Evolution

    NASA Technical Reports Server (NTRS)

    Rothschild, Lynn J.

    2010-01-01

    The combination of evolutionary with engineering principles will enhance synthetic biology. Conversely, synthetic biology has the potential to enrich evolutionary biology by explaining why some adaptive space is empty, on Earth or elsewhere. Synthetic biology, the design and construction of artificial biological systems, substitutes bio-engineering for evolution, which is seen as an obstacle. But because evolution has produced the complexity and diversity of life, it provides a proven toolkit of genetic materials and principles available to synthetic biology. Evolution operates on the population level, with the populations composed of unique individuals that are historical entities. The source of genetic novelty includes mutation, gene regulation, sex, symbiosis, and interspecies gene transfer. At a phenotypic level, variation derives from regulatory control, replication and diversification of components, compartmentalization, sexual selection and speciation, among others. Variation is limited by physical constraints such as diffusion, and chemical constraints such as reaction rates and membrane fluidity. While some of these tools of evolution are currently in use in synthetic biology, all ought to be examined for utility. A hybrid approach of synthetic biology coupled with fine-tuning through evolution is suggested

  18. Geomagnetic field strength 3.2 billion years ago recorded by single silicate crystals.

    PubMed

    Tarduno, John A; Cottrell, Rory D; Watkeys, Michael K; Bauch, Dorothy

    2007-04-05

    The strength of the Earth's early geomagnetic field is of importance for understanding the evolution of the Earth's deep interior, surface environment and atmosphere. Palaeomagnetic and palaeointensity data from rocks formed near the boundary of the Proterozoic and Archaean eons, some 2.5 Gyr ago, show many hallmarks of the more recent geomagnetic field. Reversals are recorded, palaeosecular variation data indicate a dipole-dominated morphology and available palaeointensity values are similar to those from younger rocks. The picture before 2.8 Gyr ago is much less clear. Rocks of the Archaean Kaapvaal craton (South Africa) are among the best-preserved, but even they have experienced low-grade metamorphism. The variable acquisition of later magnetizations by these rocks is therefore expected, precluding use of conventional palaeointensity methods. Silicate crystals from igneous rocks, however, can contain minute magnetic inclusions capable of preserving Archaean-age magnetizations. Here we use a CO2 laser heating approach and direct-current SQUID magnetometer measurements to obtain palaeodirections and intensities from single silicate crystals that host magnetite inclusions. We find 3.2-Gyr-old field strengths that are within 50 per cent of the present-day value, indicating that a viable magnetosphere sheltered the early Earth's atmosphere from solar wind erosion.

  19. Intergalactic Lyman continuum photon budget in the past 5 billion years

    NASA Astrophysics Data System (ADS)

    Gaikwad, Prakash; Khaire, Vikram; Choudhury, Tirthankar Roy; Srianand, Raghunathan

    2017-04-01

    We constrain the H I photoionization rate (Γ _{H I}) at z ≲ 0.45 by comparing the flux probability distribution function and power spectrum of the Lyα forest data along 82 Quasi-Stellar Object (QSO) sightlines obtained using Cosmic Origins Spectrograph with models generated from smoothed particle hydrodynamic simulations. We have developed a module named 'Code for Ionization and Temperature Evolution (CITE)' for calculating the intergalactic medium (IGM) temperature evolution from high to low redshifts by post-processing the GADGET-2 simulation outputs. Our method, that produces results consistent with other simulations, is computationally less expensive thus allowing us to explore a large parameter space. It also allows rigorous estimation of the error covariance matrix for various statistical quantities of interest. We find that the best-fitting Γ _{H I}(z) increases with z and follows (4 ± 0.1) × 10-14 (1 + z)4.99 ± 0.12 s-1. At any given z, the typical uncertainties Δ Γ _{H I} / Γ _{H I} are ∼25 per cent that contains not only the statistical errors but also those arising from possible degeneracy with the thermal history of the IGM and cosmological parameters and uncertainties in fitting the QSO continuum. These values of Γ _{H I} favour the scenario where only QSOs contribute to the ionizing background at z < 2. Our derived 3σ upper limit on average escape fraction is 0.008, consistent with measurements of low-z galaxies.

  20. Connecting galaxy and supermassive black hole growth during the last 8 billion years

    NASA Astrophysics Data System (ADS)

    Juneau, Stephanie

    It has become increasingly clear that a complete picture of galaxy evolution requires a better understanding of the role of Active Galactic Nuclei (AGN). In particular, they could be responsible for regulating star formation and galaxy growth via feedback processes. There are also competing views about the main modes of stellar growth and supermassive black hole growth in galaxies that need to be resolved. With high infrared luminosities (thus star formation rates) and a frequent occurrence of AGN, galaxies selected in the far-infrared wavebands form an ideal sample to search for a connection between AGN and star formation. The first part of this thesis contains a detailed analysis of the molecular gas properties of nearby infrared luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs). We find that the enhanced molecular gas density in the most IR-luminous systems can be explained by major galaxy mergers, and that AGN are more likely to reside in higher-density systems. While the frequent concurrence of AGN and galaxy mergers in ULIRGs was already established, this work provides a coherent framework that explains trends observed with five molecular gas tracers with a broad range of critical densities, and a comparison with simulations that reproduce observed molecular line ratios without invoking AGN-induced chemistry. The second part of the thesis presents an analysis of the AGN content of intermediate redshift galaxies (0.3 < z < 1). However, identifying complete AGN samples at these redshift is challenging because it is difficult to find X-ray weak or absorbed AGN. To alleviate this problem, we developed the Mass-Excitation (MEx) diagram, which is applicable out to redshift of ˜ 1 with existing optical spectra. It improves the overall AGN census by detecting AGN that are missed in even the most sensitive X-ray surveys. The new diagnostic was used to study the concurrence of star formation and AGN in 70 micron-selected galaxies from the Far-Infrared Deep Extragalactic Legacy survey. When multiple AGN diagnostics are combined, we find not only a high AGN fraction in FIR-selected galaxies (as high as for nearby FIR-selected galaxies), but a high incidence of X-ray absorbed AGN. These findings may have considerable implications for current views about the main mode of AGN growth.

  1. Evolution of the brain: from behavior to consciousness in 3.4 billion years.

    PubMed

    Oró, John J

    2004-06-01

    Once life began as single-cell organisms, evolution favored those able to seek nutrients and avoid risks. Receptors sensed the environment, memory traces were laid, and adaptive responses were made. Environmental stress, at times as dramatic as the collision of an asteroid, resulted in extinctions that favored small predators with dorsal nerve cords and cranially positioned brains. Myelination, and later thermoregulation, led to increasingly efficient neural processing. As somatosensory, visual, and auditory input increased, a neocortex developed containing both sensory and motor neural maps. Hominids, with their free hands, pushed cortical development further and began to make simple stone tools. Tools and increasing cognition allowed procurement of a richer diet that led to a smaller gut, thus freeing more energy for brain expansion. Multimodal association areas, initially developed for processing incoming sensory information, blossomed and began to provide the organism with an awareness of self and environment. Advancements in memory storage and retrieval gave the organism a sense of continuity through time. This developing consciousness eventually left visible traces, which today are dramatically evident on cave walls in France and Spain. We will take this journey from the single cell to human consciousness.

  2. ON THE LAST 10 BILLION YEARS OF STELLAR MASS GROWTH IN STAR-FORMING GALAXIES

    SciTech Connect

    Leitner, Samuel N.

    2012-02-01

    The star formation rate-stellar mass relation (SFR-M{sub *}) and its evolution (i.e., the SFR main sequence) describe the growth rate of galaxies of a given stellar mass and at a given redshift. Assuming that present-day star-forming galaxies (SFGs) were always star forming in the past, these growth rate observations can be integrated to calculate average star formation histories (SFHs). Using this Main Sequence Integration (MSI) approach, we trace present-day massive SFGs back to when they were 10%-20% of their current stellar mass. The integration is robust throughout those epochs: the SFR data underpinning our calculations are consistent with the evolution of stellar mass density in this regime. Analytic approximations to these SFHs are provided. Integration-based results reaffirm previous suggestions that current SFGs formed virtually all of their stellar mass at z < 2. It follows that massive galaxies observed at z > 2 are not the typical progenitors of SFGs today. We also check MSI-based SFHs against those inferred from analysis of the fossil record-from spectral energy distributions (SEDs) of SFGs in the Sloan Digital Sky Survey and color-magnitude diagrams (CMDs) of resolved stars in dwarf irregular galaxies. Once stellar population age uncertainties are accounted for, the main sequence is in excellent agreement with SED-based SFHs (from VESPA). Extrapolating SFR main sequence observations to dwarf galaxies, we find differences between MSI results and SFHs from CMD analysis of Advanced Camera for Surveys Nearby Galaxy Survey Treasury and Local Group galaxies. Resolved dwarfs appear to grow much slower than main sequence trends imply, and also slower than slightly higher mass SED-analyzed galaxies. This difference may signal problems with SFH determinations, but it may also signal a shift in star formation trends at the lowest stellar masses.

  3. The First Half Billion Years (z > 9): Results from the Frontier Fields

    NASA Astrophysics Data System (ADS)

    Coe, Dan A.; Bradley, Larry D.

    We present z > 9 candidates identified in Hubble Frontier Fields imaging of the first four clusters and blank parallel fields (two-thirds of the complete program). Based on the deeper Hubble imaging, we revise the redshift estimate of the CLASH z ~ 9.6 candidate MACS1149-JD to z = 9.2+0.2 -0.5 (95% C.L.). We identify a new possible fainter z ~ 9 companion 3'' away (~1 kpc in the source plane). And we discover a new z ~ 9.2 candidate in the MACS1149 parallel field. Combined with previously published candidates at z ~ 9.8 and 9.1 (in A2744 and its parallel field, respectively), these five z > 9 candidates fall below our published expectation of 8 - 47 at this stage in the program. We attribute some of this shortfall to incompleteness, which we have yet to quantify. At z ~ 8 (7.5 - 8.5), we detect 26 candidates down to F160W H < 28.7 AB, roughly one-third the ~82 we expect. If our z > 9 incompleteness is similar (~68%), our results would support the sharp drop in z > 9 number counts claimed by some (but not all) previous works and supported by several (but not all) theoretical models. Properly quantifying our incompleteness will require adding simulated high-redshift galaxies into the images and testing our recovery rate. Additionally, incorporating the deep Spitzer imaging into our analysis could potentially significantly improve our identification of z > 9 candidates by rejecting low-redshift (z ~ 2) interlopers. Data from the full Frontier Fields program will provide strong evidence for or against accelerated evolution and a sharp drop in the cosmic star formation rate density at z > 9.

  4. The discovery of fullerenes in the 1.85 billion-year-old Sudbury meteorite crater

    SciTech Connect

    Becker, L.; Bada, J.L.; Winans, R.E.; Hunt, J.E.; Bunch, T.E.; French, B.M.

    1996-02-01

    Fullerenes (C{sub 60}, C{sub 70}) have been identified by laser time-of-flight and electron-ionization mass spectroscopy in rock samples (black tuff in the Onaping formation) from the crater. They were likely synthesized within the impact plume from carbon contained in the meteorite. The isotopic ratios suggest {sup 13}C enrichment. They are associated with sulfur which may have protected them. This is the largest known deposit of naturally occurring fullerenes.

  5. How Long Is a Piece of String? 4.5 Billion Years Perhaps!

    ERIC Educational Resources Information Center

    Russell, Terry; McGuigan, Linda

    2014-01-01

    As reported in an earlier article (Russell and McGuigan, 2014), with Nuffield Foundation support, the authors of this article have been exploring with a group of primary teachers the teaching and learning of evolution and inheritance, focusing on conceptual progression. The new National Curriculum for England requires learners to access knowledge…

  6. THE CHEMICAL EVOLUTION OF STAR-FORMING GALAXIES OVER THE LAST 11 BILLION YEARS

    SciTech Connect

    Zahid, H. Jabran; Kewley, Lisa J.; Geller, Margaret J.; Hwang, Ho Seong; Fabricant, Daniel G.; Kurtz, Michael J.

    2013-07-10

    We calculate the stellar mass-metallicity relation at five epochs ranging to z {approx} 2.3. We quantify evolution in the shape of the mass-metallicity relation as a function of redshift; the mass-metallicity relation flattens at late times. There is an empirical upper limit to the gas-phase oxygen abundance in star-forming galaxies that is independent of redshift. From examination of the mass-metallicity relation and its observed scatter, we show that the flattening at late times is a consequence of evolution in the stellar mass where galaxies enrich to this empirical upper metallicity limit; there is also evolution in the fraction of galaxies at a fixed stellar mass that enrich to this limit. The stellar mass where metallicities begin to saturate is {approx}0.7 dex smaller in the local universe than it is at z {approx} 0.8.

  7. Three billion years of crustal evolution in eastern Canada: Constraints from receiver functions

    NASA Astrophysics Data System (ADS)

    Petrescu, L.; Bastow, I. D.; Darbyshire, F. A.; Gilligan, A.; Bodin, T.; Menke, W.; Levin, V.

    2016-02-01

    The geological record of SE Canada spans more than 2.5 Ga, making it a natural laboratory for the study of crustal formation and evolution over time. We estimate the crustal thickness, Poisson's ratio, a proxy for bulk crustal composition, and shear velocity (Vs) structure from receiver functions at a network of seismograph stations recently deployed across the Archean Superior Craton, the Proterozoic Grenville, and the Phanerozoic Appalachian provinces. The bulk seismic crustal properties and shear velocity structure reveal a correlation with tectonic provinces of different ages: the post-Archean crust becomes thicker, faster, more heterogeneous, and more compositionally evolved. This secular variation pattern is consistent with a growing consensus that crustal growth efficiency increased at the end of the Archean. A lack of correlation among elevation, Moho topography, and gravity anomalies within the Proterozoic belt is better explained by buoyant mantle support rather than by compositional variations driven by lower crustal metamorphic reactions. A ubiquitous ˜20 km thick high-Vs lower crustal layer is imaged beneath the Proterozoic belt. The strong discontinuity at 20 km may represent the signature of extensional collapse of an orogenic plateau, accommodated by lateral crustal flow. Wide anorthosite massifs inferred to fractionate from a mafic mantle source are abundant in Proterozoic geology and are underlain by high-Vs lower crust and a gradational Moho. Mafic underplating may have provided a source for these intrusions and could have been an important post-Archean process stimulating mafic crustal growth in a vertical sense.

  8. 3.5 billion years of glass bioalteration: Volcanic rocks as a basis for microbial life?

    SciTech Connect

    Staudigel, H.; Furnes, H.; McLoughlin, N.; Banerjee, N.R.; Connell, L.B.; Templeton, A.

    2009-04-07

    Alteration textures in volcanic glass from the seafloor fall into two classes, one suggestive of abiotic/diffusive hydration and chemical exchange, and another likely to be caused by microbial, cavity-forming, congruent dissolution. Glass bioalteration is common in submarine lavas throughout the world's ocean, dominant in the upper 300 m of the oceanic crust, and found in all well-preserved ophiolites and greenstone belts dating back to 3.5 Ga. It may yield a significant fraction of the global biomass and geochemical fluxes and is relevant to the development of the earliest life on Earth. We present a critical review concerning these glass bioalteration textures and present new data on their microchemical environment. We explore arguments for their biogenicity and further develop the prevalent model for their formation by relating corrosion morphology to the mechanism of microbial dissolution. Biological alteration produces conspicuous micron-scale granular and tubular textures. Granular glass alteration is well explained by colonizing microbes that selectively dissolve the glass in their contact area, forming a sponge-like interconnected network of micron-sized cavities along glass surfaces. Tubular alteration meanwhile, is more likely to be caused by filamentous cell extensions in a process similar to fungal tunneling of soil feldspars and marine carbonates. While we see clear functional similarities to fungal dissolution behavior, we do not know whether fungal or prokaryotic organisms are involved. However, this functional constraint may eventually help to identify potential microbes responsible for these features, potentially including eukaryotic or prokaryotic organisms. Yet, we caution that these organisms may be difficult to identify and to study, because they are likely to be sparsely distributed, slow growing, and difficult to cultivate.

  9. A powerful toolkit for synthetic biology: Over 3.8 billion years of evolution.

    PubMed

    Rothschild, Lynn J

    2010-04-01

    The combination of evolutionary with engineering principles will enhance synthetic biology. Conversely, synthetic biology has the potential to enrich evolutionary biology by explaining why some adaptive space is empty, on Earth or elsewhere. Synthetic biology, the design and construction of artificial biological systems, substitutes bio-engineering for evolution, which is seen as an obstacle. But because evolution has produced the complexity and diversity of life, it provides a proven toolkit of genetic materials and principles available to synthetic biology. Evolution operates on the population level, with the populations composed of unique individuals that are historical entities. The source of genetic novelty includes mutation, gene regulation, sex, symbiosis, and interspecies gene transfer. At a phenotypic level, variation derives from regulatory control, replication and diversification of components, compartmentalization, sexual selection and speciation, among others. Variation is limited by physical constraints such as diffusion, and chemical constraints such as reaction rates and membrane fluidity. While some of these tools of evolution are currently in use in synthetic biology, all ought to be examined for utility. A hybrid approach of synthetic biology coupled with fine-tuning through evolution is suggested.

  10. Stimulus Plan Aids Education: House Bill Could Provide $100 Billion to K-12 Schools

    ERIC Educational Resources Information Center

    Klein, Alyson

    2009-01-01

    Cash-strapped school districts could see an unprecedented $100 billion infusion of federal aid under a massive economic-stimulus package unveiled by House Democrats this week. The overall measure, put forth January 15 by the House Appropriations Committee, is aimed at providing a $825 billion jolt to the stumbling U.S. economy, and to help avert…

  11. cis-1,2-Dichloroethylene

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 09 / 006 F www.epa.gov / iris TOXICOLOGICAL REVIEW OF cis - 1,2 - DICHLOROETHYLENE and trans - 1,2 - DICHLOROETHYLENE ( CAS Nos . cis : 156 - 59 - 2 ; trans : 156 - 60 - 5 ; mixture : 540 - 59 - 0 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS )

  12. Federal AIDS funding tops $4 billion in FY 99.

    PubMed

    1998-12-01

    AIDS-related funding for fiscal year (FY) 1999 is up $800 million from FY 1998 levels. The increases are earmarked for treatment and prevention programs, Ryan White funding, AIDS research, and housing for people with HIV. The spending package also allocates more funding for substance abuse treatment and prevention programs. A chart details the breakdown of funding by category.

  13. Billion here, a billion there - a review and analysis of synthetic-fuels development under Title I of the Energy Security Act

    SciTech Connect

    Contratto, D.C.

    1980-01-01

    Title I of the Energy Security Act launched a synthetic fuels program that could produce 2 billion barrels of fuel per day by 1992 and could cost $88 billion. A review of the Act's statutory language to see how implementation will take place and to identify potential problems and opportunities concludes that there is room for creative use of the money in the institutional structure. It will be up to those in charge of implementing the Act to seek out and develop these opportunities. 271 references.

  14. Food security: the challenge of feeding 9 billion people.

    PubMed

    Godfray, H Charles J; Beddington, John R; Crute, Ian R; Haddad, Lawrence; Lawrence, David; Muir, James F; Pretty, Jules; Robinson, Sherman; Thomas, Sandy M; Toulmin, Camilla

    2010-02-12

    Continuing population and consumption growth will mean that the global demand for food will increase for at least another 40 years. Growing competition for land, water, and energy, in addition to the overexploitation of fisheries, will affect our ability to produce food, as will the urgent requirement to reduce the impact of the food system on the environment. The effects of climate change are a further threat. But the world can produce more food and can ensure that it is used more efficiently and equitably. A multifaceted and linked global strategy is needed to ensure sustainable and equitable food security, different components of which are explored here.

  15. U.S. Billion-Ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry

    SciTech Connect

    Downing, Mark; Eaton, Laurence M; Graham, Robin Lambert; Langholtz, Matthew H; Perlack, Robert D; Turhollow Jr, Anthony F; Stokes, Bryce; Brandt, Craig C

    2011-08-01

    The report, Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply (generally referred to as the Billion-Ton Study or 2005 BTS), was an estimate of 'potential' biomass based on numerous assumptions about current and future inventory, production capacity, availability, and technology. The analysis was made to determine if conterminous U.S. agriculture and forestry resources had the capability to produce at least one billion dry tons of sustainable biomass annually to displace 30% or more of the nation's present petroleum consumption. An effort was made to use conservative estimates to assure confidence in having sufficient supply to reach the goal. The potential biomass was projected to be reasonably available around mid-century when large-scale biorefineries are likely to exist. The study emphasized primary sources of forest- and agriculture-derived biomass, such as logging residues, fuel treatment thinnings, crop residues, and perennially grown grasses and trees. These primary sources have the greatest potential to supply large, reliable, and sustainable quantities of biomass. While the primary sources were emphasized, estimates of secondary residue and tertiary waste resources of biomass were also provided. The original Billion-Ton Resource Assessment, published in 2005, was divided into two parts-forest-derived resources and agriculture-derived resources. The forest resources included residues produced during the harvesting of merchantable timber, forest residues, and small-diameter trees that could become available through initiatives to reduce fire hazards and improve forest health; forest residues from land conversion; fuelwood extracted from forests; residues generated at primary forest product processing mills; and urban wood wastes, municipal solid wastes (MSW), and construction and demolition (C&D) debris. For these forest resources, only residues, wastes, and small-diameter trees were

  16. Rules Set for $4 Billion Race to Top Contest: Final Rules Give States Detailed Map in Quest for $4 Billion in Education Stimulus Aid

    ERIC Educational Resources Information Center

    McNeil, Michele

    2009-01-01

    For a good shot at $4 billion in grants from the federal Race to the Top Fund, states will need to make a persuasive case for their education reform agendas, demonstrate significant buy-in from local school districts, and devise plans to evaluate teachers and principals based on student performance, according to final regulations released last…

  17. NREL Helps Clean Cities Displace Billions of Gallons of Petroleum, One Vehicle at a Time (Fact Sheet)

    SciTech Connect

    Not Available

    2010-10-01

    With more than 15 years and nearly 3 billion gallons of displaced petroleum under its belt, the Clean Cities program relies on the support and expertise of the National Renewable Energy Laboratory (NREL). An initiative of the U.S. Department of Energy (DOE), Clean Cities creates public-private partnerships with a common mission: to reduce petroleum consumption in the transportation sector. Since the inception of Clean Cities in 1993, NREL has played a central role in supporting the program, an effort that stems from the laboratory's strategy to put scientific innovation into action in the marketplace.

  18. Feeding nine billion: the challenge to sustainable crop production.

    PubMed

    Gregory, Peter J; George, Timothy S

    2011-11-01

    In the recent past there was a widespread working assumption in many countries that problems of food production had been solved, and that food security was largely a matter of distribution and access to be achieved principally by open markets. The events of 2008 challenged these assumptions, and made public a much wider debate about the costs of current food production practices to the environment and whether these could be sustained. As in the past 50 years, it is anticipated that future increases in crop production will be achieved largely by increasing yields per unit area rather than by increasing the area of cropped land. However, as yields have increased, so the ratio of photosynthetic energy captured to energy expended in crop production has decreased. This poses a considerable challenge: how to increase yield while simultaneously reducing energy consumption (allied to greenhouse gas emissions) and utilizing resources such as water and phosphate more efficiently. Given the timeframe in which the increased production has to be realized, most of the increase will need to come from crop genotypes that are being bred now, together with known agronomic and management practices that are currently under-developed.

  19. Lewin estimates 2 billion barrels of US tar sand recoverable at mid $20/bbl

    SciTech Connect

    Not Available

    1986-12-01

    In 1983, Lewin and Associates prepared a report which established that the US tar sands resource amounts to over 60 billion barrels of bitumen in-place. However, no estimate was made of the technically or economically recoverable portion of this resource. More recent work carried out by Lewin for the US Department of Energy presents an appraisal of technically and economically recoverable tar sands. The paper describes the tar sand resource in-place, tar sand recovery models used in the study, engineering cost models, the economics of the steam soak prospect, and the economics of a surface mining prospect. The results of the Lewin study show that 5.7 billion barrels of domestic tar sand are technically recoverable, using cyclic steam injection and surface extractive mining. Of this, 4.9 billion barrels are technically recoverable from surface mining methods, with 0.8 billion recoverable from steam soak applications. 1 figure, 3 tables.

  20. 234U/238U Disequilibrium along stylolitic discontinuities in deep Mesozoic limestone formations of the Eastern Paris basin: evidence for discrete uranium mobility over the last 1-2 million years

    NASA Astrophysics Data System (ADS)

    Deschamps, P.; Hillaire-Marcel, C. E.; Michelot, J.-L.; Doucelance, R.; Ghaleb, B.; Buschaert, S.

    The (234U/238) equilibrium state of borehole core samples from the deep, low-permeability limestone formations surrounding the target argilite layer of the Meuse/Haute-Marne experimental site of the French agency for nuclear waste management -ANDRA- (Agence nationale pour la gestion des déchets radioactifs) was examined to improve understanding of naturally occurring radionuclide behaviour in such geological settings. Highly precise, accurate MC-ICP-MS measurements of the (234U/238U) activity ratio show that limestone samples characterised by pressure dissolution structures (stylolites or dissolution seams) display systematic (234U/238U) disequilibria, while the pristine carbonate samples remain in the secular equilibrium state. The systematic feature is observed throughout the zones marked by pressure dissolution structures: (i) the material within the seams shows a deficit of 234U over 238U ((234U/238U) down to 0.80) and (ii) the surrounding carbonate matrix is characterised by an activity ratio greater than unity (up to 1.05). These results highlight a centimetric-scale uranium remobilisation in the limestone formations along these sub-horizontal seams. Although their nature and modalities are not fully understood, the driving processes responsible for these disequilibria were active during the last 1-2 Ma.

  1. If slow rate of health care spending growth persists, projections may be off by $770 billion.

    PubMed

    Cutler, David M; Sahni, Nikhil R

    2013-05-01

    Despite earlier forecasts to the contrary, US health care spending growth has slowed in the past four years, continuing a trend that began in the early 2000s. In this article we attempt to identify why US health care spending growth has slowed, and we explore the spending implications if the trend continues for the next decade. We find that the 2007-09 recession, a one-time event, accounted for 37 percent of the slowdown between 2003 and 2012. A decline in private insurance coverage and cuts to some Medicare payment rates accounted for another 8 percent of the slowdown, leaving 55 percent of the spending slowdown unexplained. We conclude that a host of fundamental changes--including less rapid development of imaging technology and new pharmaceuticals, increased patient cost sharing, and greater provider efficiency--were responsible for the majority of the slowdown in spending growth. If these trends continue during 2013-22, public-sector health care spending will be as much as $770 billion less than predicted. Such lower levels of spending would have an enormous impact on the US economy and on government and household finances.

  2. 1,1,2-Trichloroethane

    Integrated Risk Information System (IRIS)

    1,1,2 - Trichloroethane ; CASRN 79 - 00 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcino

  3. 1,2,4-Tribromobenzene

    Integrated Risk Information System (IRIS)

    1,2,4 - Tribromobenzene ; CASRN 615 - 54 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcin

  4. 1,1,2-Trichloropropane

    Integrated Risk Information System (IRIS)

    1,1,2 - Trichloropropane ; CASRN 598 - 77 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarci

  5. 1,2,3-Trichloropropane

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 08 / 010F www.epa.gov / iris TOXICOLOGICAL REVIEW OF 1,2,3 - TRICHLOROPROPANE ( CAS No . 96 - 18 - 4 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) September 2009 U.S . Environmental Protection Agency Washington DC i DISCLAIMER This document ha

  6. trans-1,2-Dichloroethylene

    Integrated Risk Information System (IRIS)

    trans - 1,2 - Dichloroethylene ; CASRN 156 - 60 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for No

  7. 1,2,4-Trichlorobenzene

    Integrated Risk Information System (IRIS)

    1,2,4 - Trichlorobenzene ; CASRN 120 - 82 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarci

  8. 1,2-Epoxybutane (EBU)

    Integrated Risk Information System (IRIS)

    1,2 - Epoxybutane ( EBU ) ; CASRN 106 - 88 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarc

  9. Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply, April 2005

    SciTech Connect

    2005-04-01

    The purpose of this report is to determine whether the land resources of the United States are capable of producing a sustainable supply of biomass sufficient to displace 30 percent or more of the country’s present petroleum consumption – the goal set by the Biomass R&D Technical Advisory Committee in their vision for biomass technologies. Accomplishing this goal would require approximately 1 billion dry tons of biomass feedstock per year.

  10. Two Billion Cars: What it Means for Climate and Energy Policy

    ScienceCinema

    Daniel Sperling

    2016-07-12

    April 13, 2009: Daniel Sperling, director of the Institute of Transportation Studies at UC Davis, presents the next installment of Berkeley Lab's Environmental Energy Technologies Divisions Distinguished Lecture series. He discusses Two Billion Cars and What it Means for Climate and Energy Policy.

  11. 2016 Billion-Ton Report: Advancing Domestic Resources for a Thriving Bioeconomy

    SciTech Connect

    Langholtz, M. H.; Stokes, B. J.; Eaton, L. M.

    2016-07-06

    This product builds on previous efforts, namely the 2005 Billion-Ton Study (BTS) and the 2011 U.S. Billion-Ton Update (BT2).With each report, greater perspective is gained on the potential of biomass resources to contribute to a national energy strategy. Similarly, each successive report introduces new questions regarding commercialization challenges. BTS quantified the broad biophysical potential of biomass nationally, and BT2 elucidated the potential economic availability of these resources. These reports clearly established the potential availability of up to one billion tons of biomass resources nationally. However, many questions remain, including but not limited to crop yields, climate change impacts, logistical operations, and systems integration across production, harvest, and conversion. The present report aims to address many of these questions through empirically modeled energy crop yields, scenario analysis of resources delivered to biorefineries, and the addition of new feedstocks. Volume 2 of the 2016 Billion-Ton Report is expected to be released by the end of 2016. It seeks to evaluate environmental sustainability indicators of select scenarios from volume 1 and potential climate change impacts on future supplies.

  12. High-Stakes Hustle: Public Schools and the New Billion Dollar Accountability

    ERIC Educational Resources Information Center

    Baines, Lawrence A.; Stanley, Gregory Kent

    2004-01-01

    High-stakes testing costs up to $50 billion per annum, has no impact on student achievement, and has changed the focus of American public schools. This article analyzes the benefits and costs of the accountability movement, as well as discusses its roots in the eugenics movements of the early 20th century.

  13. Conservation in a World of Six Billion: A Grassroots Action Guide.

    ERIC Educational Resources Information Center

    Hren, Benedict J.

    This grassroots action guide features a conservation initiative working to bring the impacts of human population growth, economic development, and natural resource consumption into balance with the limits of nature for the benefit of current and future generations. Contents include information sheets entitled "Six Billion People and Growing,""The…

  14. Mass spectrometry at and below 0.1 parts per billion

    SciTech Connect

    Bradley, M.; Palmer, F.; Pritchard, D.E.

    1994-12-31

    The single ion Penning trap mass spectrometer at M.I.T. can compare masses to within 0.1 parts per billion. We have created a short table of fundamental atomic masses and made measurements useful for calibrating the X-ray standard, and determining Avogadro`s number, the molar Plank constant, and the fine structure constant.

  15. Two Billion Cars: What it Means for Climate and Energy Policy

    SciTech Connect

    Daniel Sperling

    2009-04-15

    April 13, 2009: Daniel Sperling, director of the Institute of Transportation Studies at UC Davis, presents the next installment of Berkeley Lab's Environmental Energy Technologies Divisions Distinguished Lecture series. He discusses Two Billion Cars and What it Means for Climate and Energy Policy.

  16. The Other Inconvenient Truth: Feeding 9 Billion While Sustaining the Earth System

    NASA Astrophysics Data System (ADS)

    Foley, J. A.

    2010-12-01

    As the international community focuses on climate change as the great challenge of our era, we have been largely ignoring another looming problem — the global crisis in agriculture, food security and the environment. Our use of land, particularly for agriculture, is absolutely essential to the success of the human race: we depend on agriculture to supply us with food, feed, fiber, and, increasingly, biofuels. Without a highly efficient, productive, and resilient agricultural system, our society would collapse almost overnight. But we are demanding more and more from our global agricultural systems, pushing them to their very limits. Continued population growth (adding more than 70 million people to the world every year), changing dietary preferences (including more meat and dairy consumption), rising energy prices, and increasing needs for bioenergy sources are putting tremendous pressure on the world’s resources. And, if we want any hope of keeping up with these demands, we’ll need to double the agricultural production of the planet in the next 30 to 40 years. Meeting these huge new agricultural demands will be one of the greatest challenges of the 21st century. At present, it is completely unclear how (and if) we can do it. If this wasn’t enough, we must also address the massive environmental impacts of our current agricultural practices, which new evidence indicates rival the impacts of climate change. Simply put, providing for the basic needs of 9 billion-plus people, without ruining the biosphere in the process, will be one of the greatest challenges our species has ever faced. In this presentation, I will present a new framework for evaluating and assessing global patterns of agriculture, food / fiber / fuel production, and their relationship to the earth system, particularly in terms of changing stocks and flows of water, nutrients and carbon in our planetary environment. This framework aims to help us manage the challenges of increasing global food

  17. Educational Assistance Overpayments, A Billion Dollar Problem--A Look at the Causes, Solutions, and Collection Efforts. Veterans Administration. Report to the Congress by the Comptroller General of the United States.

    ERIC Educational Resources Information Center

    Comptroller General of the U.S., Washington, DC.

    Overpayments to veterans and veterans' dependents under the VA's educational assistance programs have increased dramatically in recent years; as of the end of 1975, cumulative overpayments totaled almost $1.4 billion. In fiscal year 1967, overpayments represented 0.7 percent of VA's total educational benefits paid, whereas in the first six months…

  18. The rapid assembly of an elliptical galaxy of 400 billion solar masses at a redshift of 2.3.

    PubMed

    Fu, Hai; Cooray, Asantha; Feruglio, C; Ivison, R J; Riechers, D A; Gurwell, M; Bussmann, R S; Harris, A I; Altieri, B; Aussel, H; Baker, A J; Bock, J; Boylan-Kolchin, M; Bridge, C; Calanog, J A; Casey, C M; Cava, A; Chapman, S C; Clements, D L; Conley, A; Cox, P; Farrah, D; Frayer, D; Hopwood, R; Jia, J; Magdis, G; Marsden, G; Martínez-Navajas, P; Negrello, M; Neri, R; Oliver, S J; Omont, A; Page, M J; Pérez-Fournon, I; Schulz, B; Scott, D; Smith, A; Vaccari, M; Valtchanov, I; Vieira, J D; Viero, M; Wang, L; Wardlow, J L; Zemcov, M

    2013-06-20

    Stellar archaeology shows that massive elliptical galaxies formed rapidly about ten billion years ago with star-formation rates of above several hundred solar masses per year. Their progenitors are probably the submillimetre bright galaxies at redshifts z greater than 2. Although the mean molecular gas mass (5 × 10(10) solar masses) of the submillimetre bright galaxies can explain the formation of typical elliptical galaxies, it is inadequate to form elliptical galaxies that already have stellar masses above 2 × 10(11) solar masses at z ≈ 2. Here we report multi-wavelength high-resolution observations of a rare merger of two massive submillimetre bright galaxies at z = 2.3. The system is seen to be forming stars at a rate of 2,000 solar masses per year. The star-formation efficiency is an order of magnitude greater than that of normal galaxies, so the gas reservoir will be exhausted and star formation will be quenched in only around 200 million years. At a projected separation of 19 kiloparsecs, the two massive starbursts are about to merge and form a passive elliptical galaxy with a stellar mass of about 4 × 10(11) solar masses. We conclude that gas-rich major galaxy mergers with intense star formation can form the most massive elliptical galaxies by z ≈ 1.5.

  19. Two ten-billion-solar-mass black holes at the centres of giant elliptical galaxies.

    PubMed

    McConnell, Nicholas J; Ma, Chung-Pei; Gebhardt, Karl; Wright, Shelley A; Murphy, Jeremy D; Lauer, Tod R; Graham, James R; Richstone, Douglas O

    2011-12-08

    Observational work conducted over the past few decades indicates that all massive galaxies have supermassive black holes at their centres. Although the luminosities and brightness fluctuations of quasars in the early Universe suggest that some were powered by black holes with masses greater than 10 billion solar masses, the remnants of these objects have not been found in the nearby Universe. The giant elliptical galaxy Messier 87 hosts the hitherto most massive known black hole, which has a mass of 6.3 billion solar masses. Here we report that NGC 3842, the brightest galaxy in a cluster at a distance from Earth of 98 megaparsecs, has a central black hole with a mass of 9.7 billion solar masses, and that a black hole of comparable or greater mass is present in NGC 4889, the brightest galaxy in the Coma cluster (at a distance of 103 megaparsecs). These two black holes are significantly more massive than predicted by linearly extrapolating the widely used correlations between black-hole mass and the stellar velocity dispersion or bulge luminosity of the host galaxy. Although these correlations remain useful for predicting black-hole masses in less massive elliptical galaxies, our measurements suggest that different evolutionary processes influence the growth of the largest galaxies and their black holes.

  20. MMap: Fast Billion-Scale Graph Computation on a PC via Memory Mapping

    PubMed Central

    Lin, Zhiyuan; Kahng, Minsuk; Sabrin, Kaeser Md.; Chau, Duen Horng (Polo); Lee, Ho; Kang, U

    2015-01-01

    Graph computation approaches such as GraphChi and TurboGraph recently demonstrated that a single PC can perform efficient computation on billion-node graphs. To achieve high speed and scalability, they often need sophisticated data structures and memory management strategies. We propose a minimalist approach that forgoes such requirements, by leveraging the fundamental memory mapping (MMap) capability found on operating systems. We contribute: (1) a new insight that MMap is a viable technique for creating fast and scalable graph algorithms that surpasses some of the best techniques; (2) the design and implementation of popular graph algorithms for billion-scale graphs with little code, thanks to memory mapping; (3) extensive experiments on real graphs, including the 6.6 billion edge YahooWeb graph, and show that this new approach is significantly faster or comparable to the highly-optimized methods (e.g., 9.5× faster than GraphChi for computing PageRank on 1.47B edge Twitter graph). We believe our work provides a new direction in the design and development of scalable algorithms. Our packaged code is available at http://poloclub.gatech.edu/mmap/. PMID:25866846

  1. [L1-2 lumbar disc herniation: a case report].

    PubMed

    Monobe, T; Fujita, T; Nakaue, Y; Nishi, N

    1996-03-01

    A 49-year-old female presented a two-year history of pain in the right thigh and lower back. Neurological examination on admission demonstrated weakness of the right iliopsoas and quadriceps, hypesthesia on the right L1-2 dermatome. Radiological examination including myelography, CT myelography and discography disclosed an L1-2 herniated disc. Sagittal MRI also revealed an L1-2, an L4-5 and L5-S1 protruded disc. A posterior microdiscectomy (Love's method) was performed for the L1-2 disc. A controlateral protruded disc which compressed the L-2 nerve root was identified and partially removed. The postoperative myelography showed residual disc. The patient was free from pain and regained normal sensorimotor function. Love's posterior microdiscectomy has a disadvantage in that the operative field is limited. Careful surgical procedure was needed to avoid injury to nerve roots and the cauda equina in a tight L1-2 lumbar canal.

  2. Side Elevation, End Elevation, Cross Section, 1/2 Roof Plan, 1/2 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Side Elevation, End Elevation, Cross Section, 1/2 Roof Plan, 1/2 Reflected Plan, 1/2 Floor Plan, 1/2 Reflected Plan - Jack's Mill Covered Bridge, Spanning Henderson Creek, Oquawka, Henderson County, IL

  3. 7 CFR 1.2 - Policy.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Policy. 1.2 Section 1.2 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS Official Records § 1.2 Policy. (a) Agencies of USDA shall comply with the time limits set forth in the FOIA and in this subpart for responding to...

  4. 29 CFR 1.2 - Definitions. 1

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 1 2012-07-01 2012-07-01 false Definitions. 1 1.2 Section 1.2 Labor Office of the Secretary of Labor PROCEDURES FOR PREDETERMINATION OF WAGE RATES § 1.2 Definitions. 1 1 These definitions... Assistance Act of 1972. (e) The term Wage Determinations OnLine (WDOL) shall mean the Government Internet...

  5. 29 CFR 1.2 - Definitions. 1

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 1 2014-07-01 2013-07-01 true Definitions. 1 1.2 Section 1.2 Labor Office of the Secretary of Labor PROCEDURES FOR PREDETERMINATION OF WAGE RATES § 1.2 Definitions. 1 1 These definitions are... Assistance Act of 1972. (e) The term Wage Determinations OnLine (WDOL) shall mean the Government Internet...

  6. 29 CFR 1.2 - Definitions. 1

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 1 2011-07-01 2011-07-01 false Definitions. 1 1.2 Section 1.2 Labor Office of the Secretary of Labor PROCEDURES FOR PREDETERMINATION OF WAGE RATES § 1.2 Definitions. 1 1 These definitions... Assistance Act of 1972. (e) The term Wage Determinations OnLine (WDOL) shall mean the Government Internet...

  7. 29 CFR 1.2 - Definitions. 1

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 1 2013-07-01 2013-07-01 false Definitions. 1 1.2 Section 1.2 Labor Office of the Secretary of Labor PROCEDURES FOR PREDETERMINATION OF WAGE RATES § 1.2 Definitions. 1 1 These definitions... Assistance Act of 1972. (e) The term Wage Determinations OnLine (WDOL) shall mean the Government Internet...

  8. 11 CFR 1.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 11 Federal Elections 1 2010-01-01 2010-01-01 false Definitions. 1.2 Section 1.2 Federal Elections FEDERAL ELECTION COMMISSION PRIVACY ACT § 1.2 Definitions. As defined in the Privacy Act of 1974 and for the purposes of this part, unless otherwise required by the context, the following terms shall...

  9. 45 CFR 1210.1-2 - Scope.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Scope. 1210.1-2 Section 1210.1-2 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE VISTA TRAINEE DESELECTION AND VOLUNTEER EARLY TERMINATION PROCEDURES General § 1210.1-2 Scope. (a) This part applies to all Trainees and...

  10. 45 CFR 1211.1-2 - Applicability.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Applicability. 1211.1-2 Section 1211.1-2 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE VOLUNTEER GRIEVANCE PROCEDURES § 1211.1-2 Applicability. This part applies to all volunteers enrolled under part A of title I of the...

  11. 43 CFR 2812.1-2 - Contents.

    Code of Federal Regulations, 2010 CFR

    2006-10-01

    ... 43 Public Lands: Interior 2 2006-10-01 2006-10-01 false Contents. 2812.1-2 Section 2812.1-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT... Bay Revested Lands § 2812.1-2 Contents. (a) An individual applicant and each member of...

  12. 43 CFR 2812.1-2 - Contents.

    Code of Federal Regulations, 2010 CFR

    1997-10-01

    ... 43 Public Lands: Interior 2 1997-10-01 1997-10-01 false Contents. 2812.1-2 Section 2812.1-2 LAND RESOURCE MANAGEMENT (2000) TRAMROADS AND LOGGING ROADS Over O. and C. and Coos Bay Revested Lands § 2812.1-2 Contents. (a) An individual applicant and each member of any unincorporated association which...

  13. The $1. 5 billion question: Can the US Global Change Research Program deliver on its promises

    SciTech Connect

    Monastersky, R.

    1993-09-04

    President Clinton has continued the funding for scientific investigations of global climatic change, increasing funds to a total of $1.5 billion spread amoung 11 different agencies. However, a growing number of critics warn that the program appears heading toward failure. The main issue is relevancy. Almost every agrees that the research effort will support important scientific work over the next decade, but it will not necessarily provide the information policymakers need to address the threat of climatic change, ozone depletion, deforestation, desertification, and similiar issues. This article summarizes the concerns and comments of critics, and the gap between the climate scientists and governmental policymakers.

  14. Greenhouse gas implications of a 32 billion gallon bioenergy landscape in the US

    NASA Astrophysics Data System (ADS)

    DeLucia, E. H.; Hudiburg, T. W.; Wang, W.; Khanna, M.; Long, S.; Dwivedi, P.; Parton, W. J.; Hartman, M. D.

    2015-12-01

    Sustainable bioenergy for transportation fuel and greenhouse gas (GHGs) reductions may require considerable changes in land use. Perennial grasses have been proposed because of their potential to yield substantial biomass on marginal lands without displacing food and reduce GHG emissions by storing soil carbon. Here, we implemented an integrated approach to planning bioenergy landscapes by combining spatially-explicit ecosystem and economic models to predict a least-cost land allocation for a 32 billion gallon (121 billion liter) renewable fuel mandate in the US. We find that 2022 GHG transportation emissions are decreased by 7% when 3.9 million hectares of eastern US land are converted to perennial grasses supplemented with corn residue to meet cellulosic ethanol requirements, largely because of gasoline displacement and soil carbon storage. If renewable fuel production is accompanied by a cellulosic biofuel tax credit, CO2 equivalent emissions could be reduced by 12%, because it induces more cellulosic biofuel and land under perennial grasses (10 million hectares) than under the mandate alone. While GHG reducing bioenergy landscapes that meet RFS requirements and do not displace food are possible, the reductions in GHG emissions are 50% less compared to previous estimates that did not account for economically feasible land allocation.

  15. On the constancy of the lunar cratering flux over the past 3.3 billion yr

    NASA Technical Reports Server (NTRS)

    Guinness, E. A.; Arvidson, R. E.

    1977-01-01

    Utilizing a method that minimizes random fluctuations in sampling crater populations, it can be shown that the ejecta deposit of Tycho, the floor of Copernicus, and the region surrounding the Apollo 12 landing site have incremental crater size-frequency distributions that can be expressed as log-log linear functions over the diameter range from 0.1 to 1 km. Slopes are indistinguishable for the three populations, probably indicating that the surfaces are dominated by primary craters. Treating the crater populations of Tycho, the floor of Copernicus, and Apollo 12 as primary crater populations contaminated, but not overwhelmed, with secondaries, allows an attempt at calibration of the post-heavy bombardment cratering flux. Using the age of Tycho as 109 m.y., Copernicus as 800 m.y., and Apollo 12 as 3.26 billion yr, there is no basis for assuming that the flux has changed over the past 3.3 billion yr. This result can be used for dating intermediate aged surfaces by crater density.

  16. The Value Of The Nonprofit Hospital Tax Exemption Was $24.6 Billion In 2011.

    PubMed

    Rosenbaum, Sara; Kindig, David A; Bao, Jie; Byrnes, Maureen K; O'Laughlin, Colin

    2015-07-01

    The federal government encourages public support for charitable activities by allowing people to deduct donations to tax-exempt organizations on their income tax returns. Tax-exempt hospitals are major beneficiaries of this policy because it encourages donations to the hospitals while shielding them from federal and state tax liability. In exchange, these hospitals must engage in community benefit activities, such as providing care to indigent patients and participating in Medicaid. The congressional Joint Committee on Taxation estimated the value of the nonprofit hospital tax exemption at $12.6 billion in 2002--a number that included forgone taxes, public contributions, and the value of tax-exempt bond financing. In this article we estimate that the size of the exemption reached $24.6 billion in 2011. The Affordable Care Act (ACA) brings a new focus on community benefit activities by requiring tax-exempt hospitals to engage in communitywide planning efforts to improve community health. The magnitude of the tax exemption, coupled with ACA reforms, underscores the public's interest not only in community benefit spending generally but also in the extent to which nonprofit hospitals allocate funds for community benefit expenditures that improve the overall health of their communities.

  17. Clusters of Galaxies in the last 5 Billion Years: from the Brightest Cluster Galaxy to the Intra-Cluster Light

    NASA Astrophysics Data System (ADS)

    Pillepich, Annalisa

    2014-10-01

    Understanding the physical processes which shape the galaxy population in the high density environment of galaxy clusters as a function of cosmic time is a central open question in galaxy evolution studies. With the Frontier Field Initiative, HST will provide an ultra-deep view and an unprecedented multi-wavelength dataset to study the galaxy population in and around galaxy clusters at intermediate redshift. With our study, we aim at providing the first self-consistent theoretical framework based on cosmological hydrodynamical simulations to understand the evolution of cluster galaxies: our analysis is designed to complement and aid the interpretation of the wealth of observational data within the LCDM Cosmology. In particular, we plan an in-depth analysis of a sample of 15 haloes with masses between 7x10^13 and 2x10^15 Msun at z=0, simulated with the gravity+hydrodynamics code Arepo. The numerical scheme and the galaxy formation model adopted in this study have already been successfully tested against a series of global measurements: they will allow us to follow the fate, within each cluster, of hundreds of well-resolved galaxies with stellar masses above 5x10^9 Msun. Our analysis will include the assembly properties of the central brightest galaxies as well as the demographics of the satellite populations and their cluster-centric gradients of colors, morphologies and star formation rates. Our setup is suitable to quantify the effects of environment on star formation, stripping, and quenching across an unprecedented range of galaxy masses, cluster masses and spatial scales, in addition to providing valuable clues about the diffuse intra-cluster light.

  18. U.S. Families Spend 1.5 Billion Hours Yearly on Kids with Special Health Needs

    MedlinePlus

    ... health care needs, the researchers estimated. Muscular dystrophy, cerebral palsy, cystic fibrosis, intellectual disability, epilepsy and head injury ... home is usually the parents. "A child with cerebral palsy might not be able to get out of ...

  19. Northwest Africa 8159: An approximately 2.3 Billion Year Old Martian Olivine-Bearing Augite Basalt

    NASA Technical Reports Server (NTRS)

    Simon, J. I.; Peters, T. J.; Tappa, M. J.; Agee, C. B.

    2014-01-01

    Based on petrology, mineralogy, and bulk composition, the new NWA 8159 martian meteorite is distinct from all known samples from Mars. In particular, the augite compositional trends are unique, but most similar to those of nakhite intercumulus. Whether NWA 8159 represents a new lithology or is related to a known meteorite group remains to be determined. Sr and Nd isotopic analyses will allow comparison of source characteristics with SNC and other new ungrouped meteorites (e.g., NWA 7635). Here we report initial Rb-Sr and Sm-Nd isotopic results for NWA 8159 with the objective to determine its formation age and to potentially identify similarities and potential source affinities with other martian rocks.

  20. The Sandvik peridotite, Gurskøy, Norway: Three billion years of mantle evolution in the Baltica lithosphere

    NASA Astrophysics Data System (ADS)

    Lapen, Thomas J.; Medaris, L. Gordon, Jr.; Beard, Brian L.; Johnson, Clark M.

    2009-05-01

    The Sandvik ultramafic body, Island of Gurskøy, Western Gneiss Region, Norway, is a mantle fragment that contains polymetamorphic mineral assemblages and affords a unique view into the response of subcontinental lithospheric mantle to repeated orogenic/magmatic events. The Sandvik peridotite body and nearby outcrops record four paragenetic stages: 1) pre-exsolution porphyroclasts of ol + grt + opx (high-Ca ) + cpx (low-Ca), which equilibrated at 1100-1200 °C and 6.5-7.0 GPa; 2) kelyphite containing ol + grt + spl +opx (low-Ca) + am (high-Al), as well as exsolved pyroxene containing opx + cpx + spl in equilibrium with matrix olivine, at 725 °C and 1.5 GPa; 3) granoblastic matrix of ol + spl + opx (low-Ca) + am (high-Al), at 700 °C and 1.0 GPa. A nearby outcrop contains a fourth assemblage consisting of ol + chl + opx + am. Lu-Hf and Re-Os model ages of garnet peridotite indicate melt depletion at 3.3 Ga [Beyer, E.E., Brueckner, H.K., Griffin, W.L., O'Reilly, S.Y., Graham, S., 2004. Archean mantle fragments in Proterozoic crust, Western Gneiss Region, Norway. Geology 32, 609-612.; Lapen, T.J., Medaris, L.G. Jr., Johnson, C.M., and Beard, B.L., 2005. Archean to Middle Proterozoic evolution of Baltica subcontinental lithosphere: evidence from combined Sm-Nd and Lu-Hf isotope analyses of the Sandvik ultramafic body, Norway. Contributions to Mineralogy and Petrology 150, 131-145.], marking the time of separation from the convecting mantle. Lu-Hf whole rock and mineral isochron ages of constituent garnet peridotite and garnet pyroxenite layers in the Sandvik body reflect cooling and emplacement at ~ 1.25 Ga and ~ 1.18 Ga, respectively, whereas Sm-Nd whole rock and mineral ages of the garnet pyroxenite layers and the garnet peridotite are consistent with metasomatic alteration at ~ 1.15 Ga [Lapen, T.J., Medaris, L.G. Jr., Johnson, C.M., and Beard, B.L., 2005. Archean to Middle Proterozoic evolution of Baltica subcontinental lithosphere: evidence from combined Sm-Nd and Lu-Hf isotope analyses of the Sandvik ultramafic body, Norway. Contributions to Mineralogy and Petrology 150, 131-145.]. The isochron ages likely record lithospheric modification associated with the 1.25-1.00 Ga Sveconorwegian orogeny and represent the youngest age of the Stage 1 mineral assemblage equilibration. A 606 ± 39 Ma Sm-Nd isochron age of the Stage 2 kelyphite assemblage is consistent with partial re-equilibration of the porphyroclastic assemblage during continental rifting associated with opening of the Iapetus Ocean between Baltica and Laurentia at ~ 600 Ma, or extension between Baltica and Siberia that may have been associated with opening of the Ægir Sea. The age of kelyphite, therefore, places the Sandvik peridotite in the uppermost mantle prior to Silurian shortening between the Baltic and Laurentian continents.

  1. Half a billion years of reworking of Hadean mafic crust to produce the Nuvvuagittuq Eoarchean felsic crust

    NASA Astrophysics Data System (ADS)

    O'Neil, Jonathan; Boyet, Maud; Carlson, Richard W.; Paquette, Jean-Louis

    2013-10-01

    The Nuvvuagittuq greenstone belt is dominated by mafic rocks, called the Ujaraaluk unit, that are mostly composed of cummingtonite-plagioclase-biotite with variable amounts of garnet. While the oldest zircons contained in thin intrusive trondhjemitic bands are ∼3.8 Ga, 146Sm-142Nd systematics suggest that the Ujaraaluk unit is as old as 4.4 Ga. The Nuvvuagittuq greenstone belt is surrounded by Eoarchean TTGs that have geochemical and isotopic compositions consistent with their derivation by partial melting of a source similar in composition and age to the Ujaraaluk unit. New zircon dates reported here show the Nuvvuagittuq TTGs to consist at least of four distinct age units of 3.76 Ga, 3.66 Ga, 3.5-3.4 Ga and 3.35 Ga. The Hf isotopic compositions of zircons from the TTG are consistent with derivation from Hadean mafic crust. The 3.66 Ga to 3.35 Ga TTGs appear to have been formed primarily from melting of a source compositionally similar to the 4.4 Ga Ujaraaluk unit, whereas the more radiogenic Hf of the zircons from the 3.76 Ga TTGs may suggest derivation from melting of a source compositionally similar to 4.1 Ga intrusive gabbros. Alternatively, the distinct rare earth element patterns of the 3.76 Ga and 3.66 Ga TTGs suggest their derivation from sources with variable amounts of residual garnet and hence formation at different depths. The composition of the older TTGs is indicative of a deeper source that may have involved a greater interaction between the melt and the mantle to explain the more radiogenic Hf isotopic compositions of their zircons. Sources compositionally similar to the Ujaraaluk unit and intrusive gabbros appear to be the most likely candidates for the Hadean precursor of the Nuvvuagittuq TTGs.

  2. The Evolution of Massive Morphological Spheroid and Disk Galaxies in CANDELS from 11 to 6 Billion Years Ago

    NASA Astrophysics Data System (ADS)

    McIntosh, Daniel H.; CANDELS Collaboration

    2017-01-01

    The premiere HST/WFC3 Treasury program CANDELS (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey) has produced detailed visual classifications for statistically useful samples of bright (H>24.5mag) galaxies during and after z~2, the epoch of peak galaxy development. By averaging multiple classifications per galaxy that encompass spheroid-only, bulge-dominated, disk-dominated, disk-only, and irregular/peculiar appearances at visible rest-frame wavelengths, we find that 90% of massive (>1e10 Msun) galaxies at 0.62 to mostly Q at later times. Combining morphologies, structural properties, and SF nature, we find clear differences in the histories of spheroid and disk populations that are robust to selections based on visual or Sersic selection, and to either Q/SF divisor. Massive spheroids experience strong number density growth, substantial size growth, and rapid changes in SF fraction suggesting quenching processes that act on <0.5 Gyr timescales. In contrast, the massive disk population undergoes a steady addition of similar-size disks and a mild decline in average sSFR. Our results indicate that active SF in disks appears to slowly build up their inner mass (or bulge), which subsequently quenches these galaxies. Data-theory comparison is needed to better constrain which physical processes drive the transformation and quenching of massive galaxies.

  3. A stimulating conversation. Healthcare organizations praise the economic stimulus law, start considering ways to use the $150 billion in relief.

    PubMed

    Lubell, Jennifer

    2009-02-23

    The industry eagerly awaits its $150 billion under the stimulus package, but not everyone will win, experts say. Still, "The initial stimulus package was a very solid start," said system exec Conway Collis, left.

  4. NASA's Fiscal Year 2012 Budget Request

    NASA Video Gallery

    NASA announced an $18.7 billion budget request for fiscal year 2012 that supports a reinvigorated path of innovation, technological development and scientific discovery. The budget supports all ele...

  5. Another Record Year for Academic Pork.

    ERIC Educational Resources Information Center

    Brainard, Jeffrey

    2002-01-01

    Discusses how, fueled by the war on terrorism, Congress has awarded a record $1.8 billion in academic earmarks in the 2002 fiscal year. Profiles several recipient programs and includes a campus-by-campus list of projects. (EV)

  6. 43 CFR 2812.1-2 - Contents.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Contents. 2812.1-2 Section 2812.1-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) TRAMROADS AND LOGGING ROADS Over O. and C. and Coos Bay Revested Lands § 2812.1-2 Contents. (a)...

  7. 43 CFR 2812.1-2 - Contents.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Contents. 2812.1-2 Section 2812.1-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) TRAMROADS AND LOGGING ROADS Over O. and C. and Coos Bay Revested Lands § 2812.1-2 Contents. (a)...

  8. 43 CFR 2812.1-2 - Contents.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Contents. 2812.1-2 Section 2812.1-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) TRAMROADS AND LOGGING ROADS Over O. and C. and Coos Bay Revested Lands § 2812.1-2 Contents. (a)...

  9. 43 CFR 2812.1-2 - Contents.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Contents. 2812.1-2 Section 2812.1-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) TRAMROADS AND LOGGING ROADS Over O. and C. and Coos Bay Revested Lands § 2812.1-2 Contents. (a)...

  10. Collision-free spatial hash functions for structural analysis of billion-vertex chemical bond networks

    NASA Astrophysics Data System (ADS)

    Zhang, Cheng; Bansal, Bhupesh; Branicio, Paulo S.; Kalia, Rajiv K.; Nakano, Aiichiro; Sharma, Ashish; Vashishta, Priya

    2006-09-01

    State-of-the-art molecular dynamics (MD) simulations generate massive datasets involving billion-vertex chemical bond networks, which makes data mining based on graph algorithms such as K-ring analysis a challenge. This paper proposes an algorithm to improve the efficiency of ring analysis of large graphs, exploiting properties of K-rings and spatial correlations of vertices in the graph. The algorithm uses dual-tree expansion (DTE) and spatial hash-function tagging (SHAFT) to optimize computation and memory access. Numerical tests show nearly perfect linear scaling of the algorithm. Also a parallel implementation of the DTE + SHAFT algorithm achieves high scalability. The algorithm has been successfully employed to analyze large MD simulations involving up to 500 million atoms.

  11. Enumeration of 166 billion organic small molecules in the chemical universe database GDB-17.

    PubMed

    Ruddigkeit, Lars; van Deursen, Ruud; Blum, Lorenz C; Reymond, Jean-Louis

    2012-11-26

    Drug molecules consist of a few tens of atoms connected by covalent bonds. How many such molecules are possible in total and what is their structure? This question is of pressing interest in medicinal chemistry to help solve the problems of drug potency, selectivity, and toxicity and reduce attrition rates by pointing to new molecular series. To better define the unknown chemical space, we have enumerated 166.4 billion molecules of up to 17 atoms of C, N, O, S, and halogens forming the chemical universe database GDB-17, covering a size range containing many drugs and typical for lead compounds. GDB-17 contains millions of isomers of known drugs, including analogs with high shape similarity to the parent drug. Compared to known molecules in PubChem, GDB-17 molecules are much richer in nonaromatic heterocycles, quaternary centers, and stereoisomers, densely populate the third dimension in shape space, and represent many more scaffold types.

  12. Investigation of Radar Propagation in Buildings: A 10 Billion Element Cartesian-Mesh FETD Simulation

    SciTech Connect

    Stowell, M L; Fasenfest, B J; White, D A

    2008-01-14

    In this paper large scale full-wave simulations are performed to investigate radar wave propagation inside buildings. In principle, a radar system combined with sophisticated numerical methods for inverse problems can be used to determine the internal structure of a building. The composition of the walls (cinder block, re-bar) may effect the propagation of the radar waves in a complicated manner. In order to provide a benchmark solution of radar propagation in buildings, including the effects of typical cinder block and re-bar, we performed large scale full wave simulations using a Finite Element Time Domain (FETD) method. This particular FETD implementation is tuned for the special case of an orthogonal Cartesian mesh and hence resembles FDTD in accuracy and efficiency. The method was implemented on a general-purpose massively parallel computer. In this paper we briefly describe the radar propagation problem, the FETD implementation, and we present results of simulations that used over 10 billion elements.

  13. Billion-atom synchronous parallel kinetic Monte Carlo simulations of critical 3D Ising systems

    SciTech Connect

    Martinez, E.; Monasterio, P.R.; Marian, J.

    2011-02-20

    An extension of the synchronous parallel kinetic Monte Carlo (spkMC) algorithm developed by Martinez et al. [J. Comp. Phys. 227 (2008) 3804] to discrete lattices is presented. The method solves the master equation synchronously by recourse to null events that keep all processors' time clocks current in a global sense. Boundary conflicts are resolved by adopting a chessboard decomposition into non-interacting sublattices. We find that the bias introduced by the spatial correlations attendant to the sublattice decomposition is within the standard deviation of serial calculations, which confirms the statistical validity of our algorithm. We have analyzed the parallel efficiency of spkMC and find that it scales consistently with problem size and sublattice partition. We apply the method to the calculation of scale-dependent critical exponents in billion-atom 3D Ising systems, with very good agreement with state-of-the-art multispin simulations.

  14. Barium fluoride whispering-gallery-mode disk-resonator with one billion quality-factor.

    PubMed

    Lin, Guoping; Diallo, Souleymane; Henriet, Rémi; Jacquot, Maxime; Chembo, Yanne K

    2014-10-15

    We demonstrate a monolithic optical whispering-gallery-mode resonator fabricated with barium fluoride (BaF₂) with an ultra-high quality (Q) factor above 10⁹ at 1550 nm, and measured with both the linewidth and cavity-ring-down methods. Vertical scanning optical profilometry shows that the root mean square surface roughness of 2 nm is achieved for our mm-size disk. To the best of our knowledge, we show for the first time that one billion Q-factor is achievable by precision polishing in relatively soft crystals with mohs hardness of 3. We show that complex thermo-optical dynamics can take place in these resonators. Beside usual applications in nonlinear optics and microwave photonics, high-energy particle scintillation detection utilizing monolithic BaF₂ resonators potentially becomes feasible.

  15. 44 CFR 1.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 44 Emergency Management and Assistance 1 2011-10-01 2011-10-01 false Definitions. 1.2 Section 1.2 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY... Emergency Management Agency. (e) Major rule means any regulation that is likely to result in: (1) An...

  16. 44 CFR 1.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Definitions. 1.2 Section 1.2 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY... Emergency Management Agency. (e) Major rule means any regulation that is likely to result in: (1) An...

  17. 24 CFR 1.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... participates in carrying out such program or activity (such as a redeveloper in the Urban Renewal Program... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false Definitions. 1.2 Section 1.2 Housing and Urban Development Office of the Secretary, Department of Housing and Urban...

  18. 24 CFR 1.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... participates in carrying out such program or activity (such as a redeveloper in the Urban Renewal Program... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Definitions. 1.2 Section 1.2 Housing and Urban Development Office of the Secretary, Department of Housing and Urban...

  19. 24 CFR 1.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... participates in carrying out such program or activity (such as a redeveloper in the Urban Renewal Program... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false Definitions. 1.2 Section 1.2 Housing and Urban Development Office of the Secretary, Department of Housing and Urban...

  20. 24 CFR 1.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... participates in carrying out such program or activity (such as a redeveloper in the Urban Renewal Program... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false Definitions. 1.2 Section 1.2 Housing and Urban Development Office of the Secretary, Department of Housing and Urban...

  1. 24 CFR 1.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... participates in carrying out such program or activity (such as a redeveloper in the Urban Renewal Program... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Definitions. 1.2 Section 1.2 Housing and Urban Development Office of the Secretary, Department of Housing and Urban...

  2. 8 CFR 1.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Definitions. 1.2 Section 1.2 Aliens and... alien means an applicant for admission coming or attempting to come into the United States at a port-of-entry, or an alien seeking transit through the United States at a port-of-entry, or an alien...

  3. AC conductivity and relaxation mechanism in (Nd1/2Li1/2)(Fe1/2V1/2)O3 ceramics

    NASA Astrophysics Data System (ADS)

    Nath, Susmita; Barik, Subrat Kumar; Choudhary, R. N. P.

    2016-05-01

    In the present study we have synthesized polycrystalline sample of (Nd1/2Li1/2)(Fe1/2V1/2)O3 ceramic by a standard high-temperature solid-state reaction technique. Studies of dielectric and electrical properties of the compound have been carried out in a wide range of temperature (RT - 400 °C) and frequency (1kHz - 1MHz) using complex impedance spectroscopic technique. The imaginary vs. real component of the complex impedance plot (Nyquist plot) of the prepared sample exhibits the existence of grain, grain boundary contributions in the complex electrical parameters and negative temperature coefficient of resistance (NTCR) type behavior like semiconductor. Details study of ac conductivity plot reveals that the material obeys universal Jonscher's power law.

  4. Cloaking spin-(1/2) matter waves

    SciTech Connect

    Lin, De-Hone

    2010-06-15

    A physical construct for the cloaking of relativistic spin-(1/2) matter waves is proposed. It is shown that when the effective energy and mass of relativistic spin-(1/2) particles moving in an effective vector field in a spherical shell are controlled, their matter waves can be perfectly guided through the shell without any distortion or loss; that is, the construct provides a three-dimensional cloaking shell for relativistic spin-(1/2) matter waves. The proposal serves as the basis for some interesting applications such as providing a method to guide the matter waves of spin particles and an ideal setup to exhibit spin-spin interactions as well as perfect quantum interferences of some global effects in spin-(1/2) matter waves.

  5. Skin cancer risk in BRCA1/2 mutation carriers.

    PubMed

    Gumaste, P V; Penn, L A; Cymerman, R M; Kirchhoff, T; Polsky, D; McLellan, B

    2015-06-01

    Women with BRCA1/2 mutations have an elevated risk of breast and ovarian cancer. These patients and their clinicians are often concerned about their risk for other cancers, including skin cancer. Research evaluating the association between BRCA1/2 mutations and skin cancer is limited and has produced inconsistent results. Herein, we review the current literature on the risk of melanoma and nonmelanoma skin cancers in BRCA1/2 mutation carriers. No studies have shown a statistically significant risk of melanoma in BRCA1 families. BRCA2 mutations have been linked to melanoma in large breast and ovarian cancer families, though a statistically significant elevated risk was reported in only one study. Five additional studies have shown some association between BRCA2 mutations and melanoma, while four studies did not find any association. With respect to nonmelanoma skin cancers, studies have produced conflicting results. Given the current state of medical knowledge, there is insufficient evidence to warrant increased skin cancer surveillance of patients with a confirmed BRCA1/2 mutation or a family history of a BRCA1/2 mutation, in the absence of standard risk factors. Nonetheless, suspected BRCA1/2 mutation carriers should be counselled about skin cancer risks and may benefit from yearly full skin examinations.

  6. Cisplatin inhibits MEK1/2

    PubMed Central

    Yamamoto, Tetsu; Tsigelny, Igor F.; Götz, Andreas W.; Howell, Stephen B.

    2015-01-01

    Cisplatin (cDDP) is known to bind to the CXXC motif of proteins containing a ferrodoxin-like fold but little is known about its ability to interact with other Cu-binding proteins. MEK1/2 has recently been identified as a Cu-dependent enzyme that does not contain a CXXC motif. We found that cDDP bound to and inhibited the activity of recombinant MEK1 with an IC50 of 0.28 μM and MEK1/2 in whole cells with an IC50 of 37.4 μM. The inhibition of MEK1/2 was relieved by both Cu+1 and Cu+2 in a concentration-dependent manner. cDDP did not inhibit the upstream pathways responsible for activating MEK1/2, and did not cause an acute depletion of cellular Cu that could account for the reduction in MEK1/2 activity. cDDP was found to bind MEK1/2 in whole cells and the extent of binding was augmented by supplementary Cu and reduced by Cu chelation. Molecular modeling predicts 3 Cu and cDDP binding sites and quantum chemistry calculations indicate that cDDP would be expected to displace Cu from each of these sites. We conclude that, at clinically relevant concentrations, cDDP binds to and inhibits MEK1/2 and that both the binding and inhibitory activity are related to its interaction with Cu bound to MEK1/2. This may provide the basis for useful interactions of cDDP with other drugs that inhibit MAPK pathway signaling. PMID:26155939

  7. Discovery of a 12 billion solar mass black hole at redshift 6.3 and its challenge to the black hole/galaxy co-evolution at cosmic dawn

    NASA Astrophysics Data System (ADS)

    Wu, Xue-Bing; Wang, Feige; Fan, Xiaohui; Yi, Weimin; Zuo, Wenwen; Bian, Fuyan; Jiang, Linhua; McGreer, Ian; Wang, Ran; Yang, Jinyi; Yang, Qian; Thompson, David; Beletsky, Yuri

    2015-08-01

    To date about 40 quasars with redshifts z>6 have been discovered. Each quasar harbors a black hole with a mass of about one billion solar masses. The existence of such black holes when the Universe was less than one billion years after the Big Bang presents significant challenges to theories of the formation and growth of black holes and the black hole/galaxy co-evolution. I will report a recent discovery of an ultra-luminous quasar at redshift z=6.30, which has an observed optical and near-infrared luminosity a few times greater than those of previously known z>6 quasars. With near-infrared spectroscopy, we obtain a black hole mass of about 12 billion solar masses, which is well consistent with the mass derived by assuming an Eddington-limited accretion. This ultra-luminous quasar with a 12 billion solar mass black hole at z>6 provides a unique laboratory to the study of the mass assembly and galaxy formation around the most massive black holes in the early Universe. It raises further challenges to the black hole/galaxy co-evolution in the epoch of cosmic reionization because the black hole needs to grow much faster than the host galaxy.

  8. A multicomponent formal [1+2+1+2]-cycloaddition for the synthesis of dihydropyridines.

    PubMed

    Girling, P Ricardo; Batsanov, Andrei S; Shen, Hong C; Whiting, Andrew

    2012-05-18

    Reaction of methoxyvinylmethylketone with different amines and aldehydes under Lewis-acid catalysed conditions results in a novel, formal, step-wise [1+2+1+2]-cycloaddition to give dihydropyridine products.

  9. Waste Management Project fiscal year 1998 multi-year work plan, WBS 1.2

    SciTech Connect

    Jacobsen, P.H.

    1997-09-23

    The Waste Management Project manages and integrates (non-TWRS) waste management activities at the site. Activities include management of Hanford wastes as well as waste transferred to Hanford from other DOE, Department of Defense, or other facilities. This work includes handling, treatment, storage, and disposal of radioactive, nonradioactive, hazardous, and mixed solid and liquid wastes. Major Waste Management Projects are the Solid Waste Project, Liquid Effluents Project, and Analytical Services. Existing facilities (e.g., grout vaults and canyons) shall be evaluated for reuse for these purposes to the maximum extent possible.

  10. Waste management project fiscal year 1998 multi-year work plan WBS 1.2

    SciTech Connect

    Slaybaugh, R.R.

    1997-08-29

    The MYWP technical baseline describes the work to be accomplished by the Project and the technical standards which govern that work. The Waste Management Project manages and integrates (non-TWRS) waste management activities at the site. Activities include management of Hanford wastes as well as waste transferred to Hanford from other DOE, Department of Defense, or other facilities. This work includes handling, treatment, storage, and disposition of radioactive, nonradioactive, hazardous, and mixed solid and liquid wastes. Major Waste Management Projects are the Solid Waste Project (SW), Liquid Effluents Project (LEP), and Analytical Services. Existing facilities (e.g., grout vaults and canyons) shall be evaluated for reuse for these purposes to the maximum extent possible. The paper tabulates the major facilities that interface with this Project, identifying the major facilities that generate waste, materials, or infrastructure for this Project and the major facilities that will receive waste and materials from this Project.

  11. Evaluation testing of a portable vapor detector for Part-Per-Billion (PPB) level UDMH and N2H4

    NASA Technical Reports Server (NTRS)

    Curran, Dan; Lueck, Dale E.

    1995-01-01

    Trace level detection of hydrazine (N2H4), monomethyl hydrazine (MMH) and unsymmetrical dimethylhydrazine (UDMH) has been receiving increased attention over the past several years. In May 1995 the American Conference of Government Industrial Hygienists (ACGIH) lowered their acceptable threshold limit value (TLV) from 100 parts-per-billion (ppb) to 10 ppb. Several types of ppb-level detectors are being developed by the United States Air Force (USAF) Space and Missile Systems Center (SMSC). A breadboard version of a portable, lightweight hydrazine detection sensor was developed and produced by Giner Corp. for the USAF. This sensor was designed for ppb level UDMH and N2H4 vapor detection in near real-time. This instrument employs electrochemical sensing, utilizing a three electrode cell with an anion-exchange polymer electrolyte membrane as the only electrolyte in the system. The sensing, counter and reference electrodes are bonded to the membrane forming a single component. The only liquid required to maintain the sensor is deionized water which hydrates the membrane. At the request of the USAF SMSC, independent testing and evaluation of the breadboard instrument was performed at NASA's Toxic Vapor Detection Laboratory (TVDL) for response to ppb-level N2H4 and UDMH and MMH. The TVDL, located at Kennedy Space Center (KSC) has the unique ability to generate calibrated sample vapor streams of N2H4, UDMH, and MMH over a range from less than 10 ppb to thousands of parts per million (ppm) with full environmental control of relative humidity (0-90%) and temperature (0-50 C). The TVDL routinely performs these types of tests. Referenced sensors were subjected to extensive testing, including precision, linearity, response/recovery times, zero and span drift, humidity and temperature effects as well as ammonia interference. Results of these tests and general operation characteristics are reported.

  12. Rapid analysis of perchlorate in drinking water at parts per billion levels using microchip electrophoresis.

    PubMed

    Gertsch, Jana C; Noblitt, Scott D; Cropek, Donald M; Henry, Charles S

    2010-05-01

    A microchip capillary electrophoresis (MCE) system has been developed for the determination of perchlorate in drinking water. The United States Environmental Protection Agency (USEPA) recently proposed a health advisory limit for perchlorate in drinking water of 15 parts per billion (ppb), a level requiring large, sophisticated instrumentation, such as ion chromatography coupled with mass spectrometry (IC-MS), for detection. An inexpensive, portable system is desired for routine online monitoring applications of perchlorate in drinking water. Here, we present an MCE method using contact conductivity detection for perchlorate determination. The method has several advantages, including reduced analysis times relative to IC, inherent portability, high selectivity, and minimal sample pretreatment. Resolution of perchlorate from more abundant ions was achieved using zwitterionic, sulfobetaine surfactants, N-hexadecyl-N,N-dimethyl-3-ammonio-1-propane sulfonate (HDAPS) and N-tetradecyl-N,N-dimethyl-3-ammonio-1-propane sulfonate (TDAPS). The system performance and the optimization of the separation chemistry, including the use of these surfactants to resolve perchlorate from other anions, are discussed in this work. The system is capable of detection limits of 3.4 +/- 1.8 ppb (n = 6) in standards and 5.6 +/- 1.7 ppb (n = 6) in drinking water.

  13. Sharing global CO2 emission reductions among one billion high emitters.

    PubMed

    Chakravarty, Shoibal; Chikkatur, Ananth; de Coninck, Heleen; Pacala, Stephen; Socolow, Robert; Tavoni, Massimo

    2009-07-21

    We present a framework for allocating a global carbon reduction target among nations, in which the concept of "common but differentiated responsibilities" refers to the emissions of individuals instead of nations. We use the income distribution of a country to estimate how its fossil fuel CO(2) emissions are distributed among its citizens, from which we build up a global CO(2) distribution. We then propose a simple rule to derive a universal cap on global individual emissions and find corresponding limits on national aggregate emissions from this cap. All of the world's high CO(2)-emitting individuals are treated the same, regardless of where they live. Any future global emission goal (target and time frame) can be converted into national reduction targets, which are determined by "Business as Usual" projections of national carbon emissions and in-country income distributions. For example, reducing projected global emissions in 2030 by 13 GtCO(2) would require the engagement of 1.13 billion high emitters, roughly equally distributed in 4 regions: the U.S., the OECD minus the U.S., China, and the non-OECD minus China. We also modify our methodology to place a floor on emissions of the world's lowest CO(2) emitters and demonstrate that climate mitigation and alleviation of extreme poverty are largely decoupled.

  14. GERLUMPH Data Release 2: 2.5 Billion Simulated Microlensing Light Curves

    NASA Astrophysics Data System (ADS)

    Vernardos, G.; Fluke, C. J.; Bate, N. F.; Croton, D.; Vohl, D.

    2015-04-01

    In the upcoming synoptic all-sky survey era of astronomy, thousands of new multiply imaged quasars are expected to be discovered and monitored regularly. Light curves from the images of gravitationally lensed quasars are further affected by superimposed variability due to microlensing. In order to disentangle the microlensing from the intrinsic variability of the light curves, the time delays between the multiple images have to be accurately measured. The resulting microlensing light curves can then be analyzed to reveal information about the background source, such as the size of the quasar accretion disk. In this paper we present the most extensive and coherent collection of simulated microlensing light curves; we have generated \\gt 2.5 billion light curves using the GERLUMPH high resolution microlensing magnification maps. Our simulations can be used to train algorithms to measure lensed quasar time delays, plan future monitoring campaigns, and study light curve properties throughout parameter space. Our data are openly available to the community and are complemented by online eResearch tools, located at http://gerlumph.swin.edu.au.

  15. Microwave spectrum of 1,2-propanediol

    NASA Astrophysics Data System (ADS)

    Lovas, F. J.; Plusquellic, D. F.; Pate, Brooks H.; Neill, Justin L.; Muckle, Matthew T.; Remijan, Anthony J.

    2009-09-01

    The microwave spectrum of the sugar alcohol 1,2-propanediol (CH 3CHOHCH 2OH) has been measured over the frequency range 6.5-25.0 GHz with several pulsed-beam Fourier-transform microwave spectrometers. Seven conformers of 1,2-propanediol have been assigned and ab initio electronic structure calculations of the 10 lowest energy forms have been calculated. Stark effect measurements were carried out on several of the lowest energy conformers to provide accurate determinations of the dipole moment components and assist in conformer assignment.

  16. Layout finishing of a 28nm, 3 billions transistors, multi-core processor

    NASA Astrophysics Data System (ADS)

    Morey-Chaisemartin, Philippe; Beisser, Eric

    2013-06-01

    Designing a fully new 256 cores processor is a great challenge for a fabless startup. In addition to all architecture, functionalities and timing issues, the layout by itself is a bottleneck due to all the process constraints of a 28nm technology. As developers of advanced layout finishing solutions, we were involved in the design flow of this huge chip with its 3 billions transistors. We had to face the issue of dummy patterns instantiation with respect to design constraints. All the design rules to generate the "dummies" are clearly defined in the Design Rule Manual, and some automatic procedures are provided by the foundry itself, but these routines don't take care of the designer requests. Such a chip, embeds both digital parts and analog modules for clock and power management. These two different type of designs have each their own set of constraints. In both cases, the insertion of dummies should not introduce unexpected variations leading to malfunctions. For example, on digital parts were signal race conditions are critical on long wires or bus, introduction of uncontrolled parasitic along these nets are highly critical. For analog devices such as high frequency and high sensitivity comparators, the exact symmetry of the two parts of a current mirror generator should be guaranteed. Thanks to the easily customizable features of our dummies insertion tool, we were able to configure it in order to meet all the designer requirements as well as the process constraints. This paper will present all these advanced key features as well as the layout tricks used to fulfill all requirements.

  17. No Photon Left Behind: How Billions of Spectral Lines are Transforming Planetary Sciences

    NASA Astrophysics Data System (ADS)

    Villanueva, Geronimo L.

    2014-06-01

    With the advent of realistic potential energy surface (PES) and dipole moment surface (DMS) descriptions, theoretically computed linelists can now synthesize accurate spectral parameters for billions of spectral lines sampling the untamed high-energy molecular domain. Being the initial driver for these databases the characterization of stellar spectra, these theoretical databases, in combination with decades of precise experimental studies (nicely compiled in community databases such as HITRAN and GEISA), are leading to unprecedented precisions in the characterization of planetary atmospheres. Cometary sciences are among the most affected by this spectroscopic revolution. Even though comets are relatively cold bodies (T˜100 K), their infrared molecular emission is mainly defined by non-LTE solar fluorescence induced by a high-energy source (Sun, T˜5600 K). In order to interpret high-resolution spectra of comets acquired with extremely powerful telescopes (e.g., Keck, VLT, NASA-IRTF), we have developed advanced non-LTE fluorescence models that integrate the high-energy dynamic range of ab-initio databases (e.g., BT2, VTT, HPT2, BYTe, TROVE) and the precision of laboratory and semi-empirical compilations (e.g., HITRAN, GEISA, CDMS, WKMC, SELP, IUPAC). These new models allow us to calculate realistic non-LTE pumps, cascades, branching-ratios, and emission rates for a broad range of excitation regimes for H2O, HDO, HCN, HNC and NH3. We have implemented elements of these compilations to the study of Mars spectra, and we are now exploring its application to modeling non-LTE emission in exoplanets. In this presentation, we present application of these advanced models to interpret highresolution spectra of comets, Mars and exoplanets.

  18. 50 CFR 1.2 - Authorized representative.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR GENERAL PROVISIONS DEFINITIONS § 1.2 Authorized representative. Authorized representative means the subordinate... matters. The Director, U.S. Fish and Wildlife Service is frequently the authorized representative of...

  19. 8 CFR 1.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Nationality DEPARTMENT OF HOMELAND SECURITY GENERAL PROVISIONS DEFINITIONS § 1.2 Definitions. As used in this... otherwise noted, means the Department of Homeland Security. Director or district director prior to March 1... or after March 1, 2003, pursuant to delegation from the Secretary of Homeland Security or...

  20. 1,1,1,2-Tetrafluoroethane

    Integrated Risk Information System (IRIS)

    1,1,1,2 - Tetrafluoroethane ; CASRN 811 - 97 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Nonca

  1. 1,2,4,5-Tetrachlorobenzene

    Integrated Risk Information System (IRIS)

    1,2,4,5 - Tetrachlorobenzene ; CASRN 95 - 94 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Nonca

  2. 1,1,2,2-Tetrachloroethane

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 09 / 001 F www.epa.gov / iris TOXICOLOGICAL REVIEW OF 1,1,2,2 - TETRACHLOROETHANE ( CAS No . 79 - 34 - 5 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) September 2010 U.S . Environmental Protection Agency Washington , DC ii DISCLAIMER This docu

  3. 1,2,3-triazolium ionic liquids

    SciTech Connect

    Luebke, David; Nulwala, Hunaid; Tang, Chau

    2014-12-09

    The present invention relates to compositions of matter that are ionic liquids, the compositions comprising substituted 1,2,3-triazolium cations combined with any anion. Compositions of the invention should be useful in the separation of gases and, perhaps, as catalysts for many reactions.

  4. Theoretical study of the photo-isomerisation reactions of 1,2-dihydro-1,2-phosphaborine and 1,2-dihydro-1,2-alumazaine

    NASA Astrophysics Data System (ADS)

    Su, Ming-Der

    2015-07-01

    The mechanisms of the photochemical isomerisation reactions are investigated theoretically using the model systems, 1,2-dihydro-1,2-phosphaborine (5) and 1,2-dihydro-1,2-alumazaine (6), using the CAS(6,6)/6-311G(d,p) and MP2-CAS-(6,6)/6-311++G(3df,3pd)//CAS(6,6)/6-311G(d,p) methods. For each model reactant, three reaction pathways, which lead to three kinds of photo-isomers, are examined. The structures of the conical intersections, which play a key role in such photo-rearrangements, are determined. The thermal (or dark) reactions of the reactant species are also examined, using the same level of theory, to provide a qualitative explanation of the reaction pathways. These model investigations demonstrate that the preferred reaction route for these two aromatic heterocyclics is as follows: reactant → Franck-Condon region → conical intersection → photoproduct. The theoretical evidences anticipate that after irradiation of 5, the photoproduct yield of the Dewar BP-isomer, 8, should be larger than that of the Dewar BP-isomer, 7, whereas no Dewar BP-isomer 9 can be observed. Moreover, the present theoretical data predict after irradiation of 6, all three Dewar AlN-isomers (10, 11, and 12) and the starting molecule, 6, are produced.

  5. 1,1,1,2-Tetrachloroethane

    Integrated Risk Information System (IRIS)

    1,1,1,2 - Tetrachloroethane ; CASRN 630 - 20 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Nonca

  6. 1,2-Dibromo-3-chloropropane (DBCP)

    Integrated Risk Information System (IRIS)

    1,2 - Dibromo - 3 - chloropropane ( DBCP ) ; CASRN 96 - 12 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessm

  7. Industrial R&D Spending Reached $26.6 Billion in 1976. Science Resources Studies Highlights, May 5, 1978.

    ERIC Educational Resources Information Center

    National Science Foundation, Washington, DC. Div. of Science Resources Studies.

    This report presents data compiled as part of a comprehensive program to measure and analyze the nation's resources expended for research and development (R&D). Industry, which carries out 69% of the R&D in the United States, spent $26.6 billion on these activities in 1976, 10% above the 1975 level. In constant dollars, this presents an…

  8. $100 Billion: For Reform...or to Subsidize the Status Quo? Education Stimulus Watch. Special Report 1

    ERIC Educational Resources Information Center

    Smarick, Andy

    2009-01-01

    This is the first in a quarterly series of special reports on the K-12 education implications of the federal government's economic stimulus package, the American Recovery and Reinvestment Act (ARRA). That the ARRA, which was signed into law in February, will pump nearly $100 billion--an unprecedented sum of federal money--into K-12 education is…

  9. 77 FR 3075 - Resolution Plans Required for Insured Depository Institutions With $50 Billion or More in Total...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-23

    ... Plan will describe the plan to resolve each parent holding company under the Bankruptcy Code, the Rule... insurance fund or the economy, or if the parent company has been designated as a systemically important... association is over $50 billion and receives a CAMELS rating of 3 or worse or its parent receives...

  10. Who'll have to pay? The cost of dealing with AIDS in Asia will run into the billions.

    PubMed

    1993-11-03

    In September 1993, at a meeting funded by the Asian Development Bank and the United Nations Development Program, researchers, economists, and government health officials from China, India, Indonesia, South Korea, Burma, the Philippines, Sri Lanka, and Thailand met to discuss the economic effects of human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) on Asia. The World Health Organization (WHO) places the estimate of the number of people in India who are infected with HIV at around 1 million. However, Jacob John of Vellore Medical College (who first discovered the virus in India) places the estimate at higher than 2.5 million with an increase to 9-18 million by the year 2000. Charles Myers of Harvard University, Mechai Viravaidya of Bangkok's Population and Community Development Association, and Stasia Obremskey ( a health and development consultant) predict 3.4-4.3 million Thais will be infected by that year. According to Obremskey, the number of AIDS cases will reach 650,000, of which 500,000 will die. Health care for full-blown AIDS costs $1016/yr, while lost productivity due to early death costs $22,000 per victim. Myers, Mechai and Obremskey state that Thailand could prevent 3.5 million cases and save $5.1 billion, if people ceased high-risk behavior and the treatment of sexually transmitted diseases was given the highest priority. In the Philippines there are only 416 reported cases of HIV and AIDS, but Dennis Maducduc of the Department of Health AIDS program states that Filipinos are secretive about this, and Orville Solon of the University of the Philippines suggests there are 100 cases for each reported case. Solon believes $15 million has been lost due to infection and death of overseas contract workers who account for 8% of the country's foreign exchange earnings. New studies in Africa, where, as in Thailand, mortality is less than predicted, suggest a less virulent strain of HIV. This apparent fact and prevention, especially

  11. Development of disease-resistant walnut rootstocks: Integration of conventional and genomic approaches (SCRI-match Year 3)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Walnuts are grown on almost every continent with total world-wide production estimated at over 4 billion in-shell pounds. California walnut growers, who produce 99% of the US walnut crop, produced an estimated 1.2 billion pounds on approximately 310,000 bearing acres with a farm gate value of approx...

  12. Gaia Data Release 1. Astrometry: one billion positions, two million proper motions and parallaxes

    NASA Astrophysics Data System (ADS)

    Lindegren, L.; Lammers, U.; Bastian, U.; Hernández, J.; Klioner, S.; Hobbs, D.; Bombrun, A.; Michalik, D.; Ramos-Lerate, M.; Butkevich, A.; Comoretto, G.; Joliet, E.; Holl, B.; Hutton, A.; Parsons, P.; Steidelmüller, H.; Abbas, U.; Altmann, M.; Andrei, A.; Anton, S.; Bach, N.; Barache, C.; Becciani, U.; Berthier, J.; Bianchi, L.; Biermann, M.; Bouquillon, S.; Bourda, G.; Brüsemeister, T.; Bucciarelli, B.; Busonero, D.; Carlucci, T.; Castañeda, J.; Charlot, P.; Clotet, M.; Crosta, M.; Davidson, M.; de Felice, F.; Drimmel, R.; Fabricius, C.; Fienga, A.; Figueras, F.; Fraile, E.; Gai, M.; Garralda, N.; Geyer, R.; González-Vidal, J. J.; Guerra, R.; Hambly, N. C.; Hauser, M.; Jordan, S.; Lattanzi, M. G.; Lenhardt, H.; Liao, S.; Löffler, W.; McMillan, P. J.; Mignard, F.; Mora, A.; Morbidelli, R.; Portell, J.; Riva, A.; Sarasso, M.; Serraller, I.; Siddiqui, H.; Smart, R.; Spagna, A.; Stampa, U.; Steele, I.; Taris, F.; Torra, J.; van Reeven, W.; Vecchiato, A.; Zschocke, S.; de Bruijne, J.; Gracia, G.; Raison, F.; Lister, T.; Marchant, J.; Messineo, R.; Soffel, M.; Osorio, J.; de Torres, A.; O'Mullane, W.

    2016-11-01

    Context. Gaia Data Release 1 (DR1) contains astrometric results for more than 1 billion stars brighter than magnitude 20.7 based on observations collected by the Gaia satellite during the first 14 months of its operational phase. Aims: We give a brief overview of the astrometric content of the data release and of the model assumptions, data processing, and validation of the results. Methods: For stars in common with the Hipparcos and Tycho-2 catalogues, complete astrometric single-star solutions are obtained by incorporating positional information from the earlier catalogues. For other stars only their positions are obtained, essentially by neglecting their proper motions and parallaxes. The results are validated by an analysis of the residuals, through special validation runs, and by comparison with external data. Results: For about two million of the brighter stars (down to magnitude 11.5) we obtain positions, parallaxes, and proper motions to Hipparcos-type precision or better. For these stars, systematic errors depending for example on position and colour are at a level of ± 0.3 milliarcsecond (mas). For the remaining stars we obtain positions at epoch J2015.0 accurate to 10 mas. Positions and proper motions are given in a reference frame that is aligned with the International Celestial Reference Frame (ICRF) to better than 0.1 mas at epoch J2015.0, and non-rotating with respect to ICRF to within 0.03 mas yr-1. The Hipparcos reference frame is found to rotate with respect to the Gaia DR1 frame at a rate of 0.24 mas yr-1. Conclusions: Based on less than a quarter of the nominal mission length and on very provisional and incomplete calibrations, the quality and completeness of the astrometric data in Gaia DR1 are far from what is expected for the final mission products. The present results nevertheless represent a huge improvement in the available fundamental stellar data and practical definition of the optical reference frame.

  13. Regiospecific synthesis of 3-substituted imidazo[1,2-a]pyridines, imidazo[1,2-a]pyrimidines, and imidazo[1,2-c]pyrimidine.

    PubMed

    Katritzky, Alan R; Xu, Yong-Jiang; Tu, Hongbin

    2003-06-13

    3-Substituted imidazo[1,2-a]pyridines, imidazo[1,2-a]pyrimidines, and imidazo[1,2-c]pyrimidine were obtained regiospecifically in yields of 35-92% in one pot by reaction of 2-aminopyridines or 2-(or 4-)aminopyrimidines, respectively, with 1,2-bis(benzotriazolyl)-1,2-(dialkylamino)ethanes.

  14. 1,1,2-Trichloro-1,2,2-trifluoroethane (CFC-113)

    Integrated Risk Information System (IRIS)

    1,1,2 - Trichloro - 1,2,2 - trifluoroethane ( CFC - 113 ) ; CASRN 76 - 13 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health

  15. Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasability of a Billion-Ton Annual Supply

    SciTech Connect

    Perlack, R.D.

    2005-12-15

    land resources of the United States are capable of producing a sustainable supply of biomass sufficient to displace 30 percent or more of the country's present petroleum consumption--the goal set by the Advisory Committee in their vision for biomass technologies. Accomplishing this goal would require approximately 1 billion dry tons of biomass feedstock per year.

  16. [China. Twelve years of the one-child policy: a critical analysis].

    PubMed

    Kubwimana, E

    1993-08-01

    Contrary to what this study of classical indicators (e.g., birth rate, fertility rate, or birth order) is able to somewhat foresee, China has experienced a slow evolution throughout the last 20 years, but the demographic behavior is irreversible. In terms of completed fertility, China has gone from a traditional level of almost 6 children per woman to 4 children around 1980 and probably less than 2.5 at the beginning of the current decade. By no means did the Chinese blindly obey the orders of those responsible for family planning, as certain Chinese specialists were, a little naively, expecting. It has been about 10 years, and the policy of limiting births is not well accepted by the entire rural population. More realistic than at the beginning of the implementation of the one child policy, many Chinese demographers now postulate a slow reduction and anticipate a replacement fertility level (2.1) in the last years of the century. The battle for a population of 1.2 billion in the year 2000 appears to be irremediably lost. From now on it will be a matter of containing the population to the limit of 1.3 billion, which is not out of the scope of the authorities if the relative general level estimations of the population are correct. Finally, the slowing of demographic growth will have been simply accelerated, at the price of creating a society which exacerbates the contrasts between city and country and between advanced and backward provinces.

  17. Spin-1/2 Optical Lattice Clock

    NASA Astrophysics Data System (ADS)

    Lemke, N. D.; Ludlow, A. D.; Barber, Z. W.; Fortier, T. M.; Diddams, S. A.; Jiang, Y.; Jefferts, S. R.; Heavner, T. P.; Parker, T. E.; Oates, C. W.

    2009-08-01

    We experimentally investigate an optical clock based on Yb171 (I=1/2) atoms confined in an optical lattice. We have evaluated all known frequency shifts to the clock transition, including a density-dependent collision shift, with a fractional uncertainty of 3.4×10-16, limited principally by uncertainty in the blackbody radiation Stark shift. We measured the absolute clock transition frequency relative to the NIST-F1 Cs fountain clock and find the frequency to be 518 295 836 590 865.2(0.7) Hz.

  18. Taming the 1.2 m Telescope

    NASA Astrophysics Data System (ADS)

    Griffin, S.; Edwards, M.; Greenwald, D.; Kono, D.; Liang, D.; Lohnes, K.; Wright, V.; Spillar, E.

    2013-09-01

    Achievable residual jitter on the 1.2 m telescope at MSSS shown in Figure 1 has historically been limited to 10-20 arc-sec. peak in moderate wind conditions due to the combination of the dynamics associated with the twin telescopes on the common declination axis shaft, and the related control system behavior. Figure 1 1.2 m Telescope The lightly damped, low frequency fundamental vibration mode shape of the telescopes rotating out of phase on the common declination axis shaft severely degraded the performance of the prior controllers. This vibration mode is easily excited by external forces such as wind loading and internal torque commands from the mount control system. The relatively poor historic performance was due to a combination of the low error rejection of external disturbances, and the controller exciting the mode. A radical new approach has been implemented that has resulted in a decrease of jitter to less than 1 arcsec under most conditions. The new approach includes minor hardware modifications to provide active damping with accelerometers as feedback sensors. This architecture has allowed a bandwidth increase of almost an order of magnitude and eliminated the large amplitude motions at the mode natural frequency, resulting in much improved pointing and jitter performance. A representative comparison of historical versus new architecture performance is shown in Figure 2 for the declination axis.

  19. Billions for biodefense: federal agency biodefense funding, FY2008-FY2009.

    PubMed

    Franco, Crystal

    2008-06-01

    Since 2001, the United States government has spent substantial resources on preparing the nation against a bioterrorist attack. Earlier articles in this series analyzed civilian biodefense funding by the federal government from fiscal years 2001 through 2008. This article updates those figures with budgeted amounts for fiscal year 2009, specifically analyzing the budgets and allocations for biodefense at the Departments of Health and Human Services, Homeland Security, Defense, Agriculture, and State and the Environmental Protection Agency and the National Science Foundation.

  20. A billion pixels, a billion stars

    NASA Astrophysics Data System (ADS)

    Gilmore, Gerry; van Leeuwen, Floor

    2016-09-01

    The Gaia spacecraft is conducting the most ambitious and thorough census of our galaxy ever attempted, gathering data on 100,000 stars every hour. With the mission's first major data release due this month, Gerry Gilmore and Floor van Leeuwen explain how the spacecraft works and assess its likely impact on the field of astrophysics

  1. Continuous transformation of a -1/2 wedge disclination line to a +1/2 one

    NASA Astrophysics Data System (ADS)

    Fukuda, Jun-Ichi

    2010-04-01

    It is known that, in the order-parameter space S2/Z2 (a typical example being a uniaxial nematic liquid crystal in three dimensions), a -1/2 wedge disclination line and a +1/2 one are topologically equivalent and can thus be transformed continuously into each other. Here we report the realization of this transformation in a simulation of a cholesteric blue phase under an electric field.

  2. 1,2-hydroxypyridonates as contrast agents for magnetic resonance imaging: TREN-1,2-HOPO.

    PubMed

    Jocher, Christoph J; Moore, Evan G; Xu, Jide; Avedano, Stefano; Botta, Mauro; Aime, Silvio; Raymond, Kenneth N

    2007-10-29

    1,2-Hydroxypyridinones (1,2-HOPO) form very stable lanthanide complexes that may be useful as contrast agents for magnetic resonance imaging (MRI). X-ray diffraction of single crystals established that the solid-state structures of the Eu(III) and the previously reported [Inorg. Chem. 2004, 43, 5452] Gd(III) complex are identical. The recently discovered sensitizing properties of 1,2-HOPO chelates for Eu(III) luminescence [J. Am. Chem. Soc. 2006, 128, 10 067] allow for direct measurement of the number of water molecules coordinated to the metal center. Fluorescence measurements of the Eu(III) complex corroborate that, in solution, two water molecules coordinate the lanthanide (q = 2) as proposed from the analysis of NMRD profiles. In addition, fluorescence measurements have verified the anion binding interactions of lanthanide TREN-1,2-HOPO complexes in solution, studied by relaxivity, revealing only very weak oxalate binding (KA = 82.7 +/- 6.5 M-1). Solution thermodynamic studies of the metal complex and free ligand have been carried out using potentiometry, spectrophotometry, and fluorescence spectroscopy. The metal ion selectivity of TREN-1,2-HOPO supports the feasibility of using 1,2-HOPO ligands for selective lanthanide binding [pGd = 19.3 (2), pZn = 15.2 (2), pCa = 8.8 (3)].

  3. Billions for biodefense: federal agency biodefense funding, FY2007-FY2008.

    PubMed

    Franco, Crystal; Deitch, Shana

    2007-06-01

    Since 2001, the U.S. government has spent substantial resources on preparing the nation against a bioterrorist attack. Earlier articles in this series analyzed civilian biodefense funding by the federal government from fiscal years 2001 through 2007. This article updates those figures with budgeted amounts for fiscal year 2008, specifically analyzing the budgets and allocations for biodefense at the Department of Health and Human Services, the Department of Homeland Security, the Department of Defense, the Department of Agriculture, the Environmental Protection Agency, the Department of State, and the National Science Foundation.

  4. Billions for biodefense: Federal Agency biodefense funding, FY2006-FY2007.

    PubMed

    Lam, Clarence; Franco, Crystal; Schuler, Ari

    2006-01-01

    Since 2001, the United States government has spent substantial resources on preparing the nation against a bioterrorist attack. Earlier articles in this series analyzed the civilian biodefense funding by the federal government from fiscal years 2001 through 2006. This article updates those figures with budgeted amounts for fiscal year 2007, specifically analyzing the budgets and allocations for biodefense at the Department of Health and Human Services, the Department of Homeland Security, the Department of Agriculture, the Environmental Protection Agency, the Department of State, and the National Science Foundation.

  5. Billions for biodefense: federal agency biodefense budgeting, FY2005-FY2006.

    PubMed

    Schuler, Ari

    2005-01-01

    Since 2001, the United States government has spent substantial resources on preparing the nation against a bioterrorist attack. An earlier article analyzed the civilian biodefense funding by the federal government from fiscal years 2001 through 2005. This article updates those figures with budgeted amounts for fiscal year 2006, specifically analyzing the budgets and allocations for biodefense at the Department of Health and Human Services, the Department of Homeland Security, the Department of Agriculture, the Environmental Protection Agency, the National Science Foundation, and the Department of State.

  6. $5.8 Billion and Change: An Exploration of Long-Term Budgetary Trends.

    ERIC Educational Resources Information Center

    Schirmer, Peter; Childress, Michael T.; Nett, Charles C.

    Over the past 20 years, the share of Kentucky's general fund dollars spent on police and corrections, and health and human services, has increased. Meanwhile, the share spent on elementary and secondary education has not changed, while higher education funding has fallen. Compared to similar states, Kentucky spends less money per student at all…

  7. With GI Bill's Billions at Stake, Colleges Compete to Lure Veterans

    ERIC Educational Resources Information Center

    Sander, Libby

    2012-01-01

    As the Post-9/11 GI Bill nears its fourth year, with more than 550,000 veterans enrolled in thousands of institutions, advocacy groups, lawmakers, and President Obama warn that veterans are vulnerable in a higher-education marketplace eager for their GI Bill dollars--with some purveyors, particularly for-profits, recruiting aggressively. The…

  8. 77 FR 30407 - 1,2-Ethanediamine, N

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-23

    ... AGENCY 40 CFR Part 180 1,2-Ethanediamine, N1-(2-aminoethyl)-, polymer with 2, 4- diisocyanato-1...-ethanediamine, N1-(2-aminoethyl)-, polymer with 2,4-diisocyanato-1-methylbenzene, when used as an inert... residues of 1,2- ethanediamine, N1-(2-aminoethyl)-, polymer with 2,4-diisocyanato-1- methylbenzene on...

  9. The 1.2 micron CMOS technology

    NASA Technical Reports Server (NTRS)

    Pina, C. A.

    1985-01-01

    A set of test structures was designed using the Jet Propulsion Laboratory (JPL) test chip assembler and was used to evaluate the first CMOS-bulk foundry runs with feature sizes of 1.2 microns. In addition to the problems associated with the physical scaling of the structures, this geometry provided an additional set of problems, since the design files had to be generated in such a way as to be capable of being processed through p-well, n-well, and twin-well processing lines. This requirement meant that the files containing the geometric design rules as well as the structure design files had to produce process-insensitive designs, a requirement that does not apply to the more mature 3.0-micron CMOS feature size technology. Because of the photolithographic steps required with this feature size, the maximum allowable chip size was 10 x 10 mm, and this chip was divided into 24 project areas, with each area being 1.6 x 1.6 mm in size. The JPL-designed structures occupied 13 out of the 21 allowable project sizes and provided the only test information obtained from these three preliminary runs. The structures were used to successfully evaluate three different manufacturing runs through two separate foundries.

  10. Siah1/2 Ubiquitin Ligases in ER Stress Signaling in Melanoma

    DTIC Science & Technology

    2015-10-01

    year will establish novel therapeutic modality for treatment of cancer , focused on melanoma. Major Task 3: Determine the effect of Siah1/2 and ER...demonstrate the importance of these activities to prostate NE lesions/tumors that are known to be the more aggressive form of prostate cancer ...1,902,606 Associate Director: Ronai, Z. 1.2 calendar (10%) Program Leader: Ronai, Z. 1.2 calendar (10%) Cancer Center Support Grant Goals: To provide

  11. 26. A sepia photograph, 7 1/2" x 8 1/2" oh ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. A sepia photograph, 7 1/2" x 8 1/2" oh semi-matte paper, aerial oblique of central Terre Haute with negative inscribed letters (prints on positive as white) along the bottom margin, "(02105-631K-118) (3-10-37. 10:30A) (R-1000) (State Normal College, Terre Haute, Ind.)" This view taken looking east shows the gas building in the near foreground right. On the reverse in red pencil, "Campus Scenes 10" and in black pencil, "1937". Source: Indiana State University Archives. - John T. Beasley Building, 632 Cherry Street (between Sixth & Seventh Streets), Terre Haute, Vigo County, IN

  12. Agricultural Baseline (BL0) scenario of the 2016 Billion-Ton Report

    SciTech Connect

    Davis, Maggie R.; Hellwinkel, Chad; Eaton, Laurence; Langholtz, Matthew H; Turhollow, Anthony; Brandt, Craig; Myers, Aaron

    2016-07-13

    Scientific reason for data generation: to serve as the reference case for the BT16 volume 1 agricultural scenarios. The agricultural baseline runs from 2015 through 2040; a starting year of 2014 is used. Date the data set was last modified: 02/12/2016 How each parameter was produced (methods), format, and relationship to other data in the data set: simulation was developed without offering a farmgate price to energy crops or residues (i.e., building on both the USDA 2015 baseline and the agricultural census data (USDA NASS 2014). Data generated are .txt output files by year, simulation identifier, county code (1-3109). Instruments used: POLYSYS (version POLYS2015_V10_alt_JAN22B) supplied by the University of Tennessee APAC The quality assurance and quality control that have been applied: • Check for negative planted area, harvested area, production, yield and cost values. • Check if harvested area exceeds planted area for annuals. • Check FIPS codes.

  13. 4% Yield Increase (HH4), All Energy Crops scenario of the 2016 Billion Ton Report

    SciTech Connect

    Davis, Maggie R.; Hellwinkel, Chad; Eaton, Laurence; Langholtz, Matthew H; Turhollow, Anthony; Brandt, Craig; Myers, Aaron

    2016-07-13

    Scientific reason for data generation: to serve as an alternate high-yield scenario for the BT16 volume 1 agricultural scenarios to compare these projections of potential biomass supplies against a reference case (agricultural baseline 10.11578/1337885). The simulation runs from 2015 through 2040; a starting year of 2014 is used but not reported. Date the data set was last modified: 02/02/2016. How each parameter was produced (methods), format, and relationship to other data in the data set: This exogenous price simulations (also referred to as “specified-price” simulations) introduces a farmgate price, and POLYSYS solves for biomass supplies that may be brought to market in response to these prices. In specified-price scenarios, a specified farmgate price is offered constantly in all counties over all years of the simulation. This simulation begins in 2015 with an offered farmgate price for primary crop residues only between 2015 and 2018 and long-term contracts for dedicated crops beginning in 2019. Expected mature energy crop yield grows at a compounding rate of 4% beginning in 2016. The yield growth assumptions are fixed after crops are planted such that yield gains do not apply. Instruments used: Policy Analysis System –POLYSYS (version POLYS2015_V10_alt_JAN22B), an agricultural policy modeling system of U.S. agriculture (crops and livestock), supplied by the University of Tennessee Institute of Agriculture, Agricultural Policy Analysis Center.

  14. ALMA Reveals Large Molecular Gas Reservoirs in Ancestors of Milky Way-Mass Galaxies at z=1.2-1.3

    NASA Astrophysics Data System (ADS)

    Papovich, Casey J.; Labbe, Ivo; Glazebrook, Karl; Quadri, Ryan; Bekiaris, Georgios; Dickinson, Mark; Finkelstein, Steven L.; Fisher, David B.; Inami, Hanae; Livermore, Rachael C.; Spitler, Lee; Straatman, Caroline; Tran, Kim-Vy

    2017-01-01

    The gas accretion and star-formation histories of galaxies like the Milky Way remain an outstanding problem in astrophysics. Observations show that 8 billion years ago, at redshifts z > 1, the progenitors to Milky Way-mass galaxies were forming stars 30 times faster than today and predicted to be rich in molecular gas, in contrast with low present-day gas fractions (<10%). Using ALMA Band 4 observations, we detected the molecular gas using the CO(J=3-2) emission (rest-frame 345.8 GHz) in a sample of galaxies at redshifts z=1.2-1.3, selected to have the stellar mass (Log M*/M⊙ =10.2) and star-formation rate (SFR = 20 M⊙ yr-1) of the main progenitors of today's Milky Way-mass galaxies at this epoch. We show that with relatively short ALMA integrations, we now probe efficiently the CO luminosities of z > 1 star-forming galaxies a factor two lower than was possible previously. The CO emission from these galaxies reveals large molecular gas reservoirs, with a ratio of molecular-gas mass-to-stellar mass of ~100%, indicating most of the baryons are in cold gas, not stars. The ratio of the galaxies' total luminosity from star formation to CO luminosity corresponds to long gas-consumption timescales. Compared to local spiral galaxies, the star-formation efficiency, estimated from the ratio of total IR luminosity to CO emission, has remained nearly constant since redshift z=1.2, despite the order of magnitude decrease in gas fraction, consistent with results for more massive and more luminous galaxies at this epoch. This implies that the the physical processes that determine the rate at which gas cools to form stars in distant galaxies appear to be similar to that in local galaxies.

  15. 3% Yield Increase (HH3), All Energy Crops scenario of the 2016 Billion Ton Report

    SciTech Connect

    Davis, Maggie R.; Hellwinkel, Chad; Eaton, Laurence; Langholtz, Matthew H.; Turhollow, Anthony; Brandt, Craig; Myers, Aaron

    2016-07-13

    Scientific reason for data generation: to serve as an alternate high-yield scenario for the BT16 volume 1 agricultural scenarios to compare these projections of potential biomass supplies against a reference case (agricultural baseline 10.11578/1337885). The simulation runs from 2015 through 2040; a starting year of 2014 is used but not reported. Date the data set was last modified: 02/02/2016 How each parameter was produced (methods), format, and relationship to other data in the data set: This exogenous price simulations (also referred to as “specified-price” simulations) introduces a farmgate price, and POLYSYS solves for biomass supplies that may be brought to market in response to these prices. In specified-price scenarios, a specified farmgate price is offered constantly in all counties over all years of the simulation. This simulation begins in 2015 with an offered farmgate price for primary crop residues only between 2015 and 2018 and long-term contracts for dedicated crops beginning in 2019. Expected mature energy crop yield grows at a compounding rate of 3% beginning in 2016. The yield growth assumptions are fixed after crops are planted such that yield gains do not apply to crops already planted, but new plantings do take advantage of the gains in expected yield growth. Instruments used: Policy Analysis System –POLYSYS (version POLYS2015_V10_alt_JAN22B), an agricultural policy modeling system of U.S. agriculture (crops and livestock), supplied by the University of Tennessee Institute of Agriculture, Agricultural Policy Analysis Center.

  16. 2% Yield Increase (HH2), All Energy Crops scenario of the 2016 Billion Ton Report

    DOE Data Explorer

    Davis, Maggie R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000181319328); Hellwinkel, Chad [University of Tennessee] (ORCID:0000000173085058); Eaton, Laurence [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000312709626); Langholtz, Matthew H [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000281537154); Turhollow, Anthony [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000228159350); Brandt, Craig [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000214707379); Myers, Aaron [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000320373827)

    2016-07-13

    Scientific reason for data generation: to serve as an alternate high-yield scenario for the BT16 volume 1 agricultural scenarios to compare these projections of potential biomass supplies against a reference case (agricultural baseline 10.11578/1337885). The simulation runs from 2015 through 2040; a starting year of 2014 is used but not reported. Date the data set was last modified: 02/02/2016 How each parameter was produced (methods), format, and relationship to other data in the data set: This exogenous price simulations (also referred to as “specified-price” simulations) introduces a farmgate price, and POLYSYS solves for biomass supplies that may be brought to market in response to these prices. In specified-price scenarios, a specified farmgate price is offered constantly in all counties over all years of the simulation. This simulation begins in 2015 with an offered farmgate price for primary crop residues only between 2015 and 2018 and long-term contracts for dedicated crops beginning in 2019. Expected mature energy crop yield grows at a compounding rate of 2% beginning in 2016. The yield growth assumptions are fixed after crops are planted such that yield gains do not apply to crops already planted, but new plantings do take advantage of the gains in expected yield growth. Instruments used: Policy Analysis System –POLYSYS (version POLYS2015_V10_alt_JAN22B), an agricultural policy modeling system of U.S. agriculture (crops and livestock), supplied by the University of Tennessee Institute of Agriculture, Agricultural Policy Analysis Center.

  17. Compound-specific carbon and hydrogen isotope analysis of sub-parts per billion level waterborne petroleum hydrocarbons

    USGS Publications Warehouse

    Wang, Y.; Huang, Y.; Huckins, J.N.; Petty, J.D.

    2004-01-01

    Compound-specific carbon and hydrogen isotope analysis (CSCIA and CSHIA) has been increasingly used to study the source, transport, and bioremediation of organic contaminants such as petroleum hydrocarbons. In natural aquatic systems, dissolved contaminants represent the bioavailable fraction that generally is of the greatest toxicological significance. However, determining the isotopic ratios of waterborne hydrophobic contaminants in natural waters is very challenging because of their extremely low concentrations (often at sub-parts ber billion, or even lower). To acquire sufficient quantities of polycyclic aromatic hydrocarbons with 10 ng/L concentration for CSHIA, more than 1000 L of water must be extracted. Conventional liquid/liquid or solid-phase extraction is not suitable for such large volume extractions. We have developed a new approach that is capable of efficiently sampling sub-parts per billion level waterborne petroleum hydrocarbons for CSIA. We use semipermeable membrane devices (SPMDs) to accumulate hydrophobic contaminants from polluted waters and then recover the compounds in the laboratory for CSIA. In this study, we demonstrate, under a variety of experimental conditions (different concentrations, temperatures, and turbulence levels), that SPMD-associated processes do not induce C and H isotopic fractionations. The applicability of SPMD-CSIA technology to natural systems is further demonstrated by determining the ??13C and ??D values of petroleum hydrocarbons present in the Pawtuxet River, RI. Our results show that the combined SPMD-CSIA is an effective tool to investigate the source and fate of hydrophobic contaminants in the aquatic environments.

  18. White Light Demonstration of One Hundred Parts per Billion Irradiance Suppression in Air by New Starshade Occulters

    NASA Technical Reports Server (NTRS)

    Levinton, Douglas B.; Cash, Webster C.; Gleason, Brian; Kaiser, Michael J.; Levine, Sara A.; Lo, Amy S.; Schindhelm, Eric; Shipley, Ann F.

    2007-01-01

    A new mission concept for the direct imaging of exo-solar planets called the New Worlds Observer (NWO) has been proposed. The concept involves flying a meter-class space telescope in formation with a newly-conceived, specially-shaped, deployable star-occulting shade several meters across at a separation of some tens of thousands of kilometers. The telescope would make its observations from behind the starshade in a volume of high suppression of incident irradiance from the star around which planets orbit. The required level of irradiance suppression created by the starshade for an efficacious mission is of order 0.1 to 10 parts per billion in broadband light. This paper discusses the experimental setup developed to accurately measure the suppression ratio of irradiance produced at the null position behind candidate starshade forms to these levels. It also presents results of broadband measurements which demonstrated suppression levels of just under 100 parts per billion in air using the Sun as a light source. Analytical modeling of spatial irradiance distributions surrounding the null are presented and compared with photographs of irradiance captured in situ behind candidate starshades.

  19. A handful of 'antipoverty' vaccines exist for neglected diseases, but the world's poorest billion people need more.

    PubMed

    Hotez, Peter

    2011-06-01

    So-called neglected tropical diseases are the most common infections of the world's poor. Almost all of the "bottom billion"--the 1.4 billion people who live below the poverty level defined by the World Bank--suffer from one or more neglected diseases including hookworm infection, sleeping sickness, or Chagas disease. These diseases are actually a cause of poverty because of their adverse effects on child growth and development and worker productivity. Vaccines to combat such diseases have come to be known as "antipoverty vaccines." Unfortunately, the recent surge in the development and delivery of vaccines to combat the major childhood killers--such as pneumococcal pneumonia and measles--has bypassed neglected diseases. Nevertheless, some vaccines for these neglected diseases are now entering the clinical pipeline. In this article I describe how some antipoverty vaccine development is proceeding and offer recommendations for stimulating further development such as through pooled funding for innovation, developing-country manufacturers, and public-private partnerships for product development.

  20. Electrical properties of Ba(Dy1/2Nb1/2)O3 ceramic

    NASA Astrophysics Data System (ADS)

    Nath, K. Amar; Chandra, K. P.; Dubey, K.; Prasad, K.

    2016-05-01

    Polycrystalline Ba(Dy1/2Nb1/2)O3 was prepared using a high-temperature solid-state reaction method. X-ray diffraction analysis indicated the formation of a single-phase cubic structure having space group Pm3m. AC impedance plots as a function of frequency at different temperatures were used to analyse the electrical behaviour of the sample, which indicated the negative temperature coefficient of resistance character. Complex impedance analysis targeted non-Debye type dielectric relaxation. Frequency dependent ac conductivity data obeyed Jonscher's power law. The apparent activation energy was estimated to be 0.97 eV at 1 kHz.

  1. Performance as Promised: How the Chandra X-ray Observatory Accomplished One of Nasa's Most Challenging Missions for Billions of Dollars Less than Originally Planned

    NASA Technical Reports Server (NTRS)

    Davidson, Greg; Hefner, Keith

    2004-01-01

    As the nation looks toward bold new ventures in space, the Chandra X-ray Observatory program offers an example of how billion-dollar missions can be successfully developed within tightening fiscal constraints. Chandra experienced many of challenges facing bold space programs (state-of-the-art technical requirements and budget-induced slips and restructurings), and yet the Chandra team achieved nearly all the originally envisioned performance for dramatically lower cost. This was accomplished by a combination of team- work, systems engineering, advanced technology insertion, and effective approaches for program implementation. A thorough tradeoff of science utility vs. cost led to the selection of a highly elliptical orbit with uncrewed robotic delivery, deployment, and maintenance. Progressive, focused technology demonstrations were accomplished prior to commitment of major resources to critical elements of the system design, such as the high resolution mirror assembly (HRMA). Pathfinder hardware was developed to reduce risks. A variety of schedule risk reduction measures were implemented and resulted in the X-ray calibration taking place exactly within five days of its originally planned date after after five years of development. The team worked together in an effective manner to contain requirements creep. reductions such as the ACIS-2 chip device. It is estimated that the above combination of measures achieved the avoidance of over $4B in costs, while enabling a highly successful mission.

  2. Metabolism of 1,2,3,4-, 1,2,3,5-, and 1,2,4,5-tetrachlorobenzene in the squirrel monkey

    SciTech Connect

    Schwartz, H.; Chu, I.; Villeneuve, D.C.; Benoit, F.M.

    1987-01-01

    The metabolism of three tetrachlorobenzene isomers (TeCB) was investigated in the squirrel monkey. The animals were administered orally 6 single doses of /sup 14/C-labeled 1,2,3,4-, 1,2,4,5-, or 1,2,3,5-tetrachlorobenzene over a 3-wk period at levels ranging from 50 to 100 mg/kg body weight (b.w) and kept in individual metabolism cages to collect urine and feces for radioassay. Approximately 38% (1,2,3,4-TeCB), 36% (1,2,3,5-TeCB), and 18% (1,2,4,5-TeCB) of the doses were excreted respectively in the feces 48 h post administration. In monkeys dosed with 1,2,3,4-TeCB, unchanged compound accounted for 50% of the fecal radioactivity. Unchanged compound accounted for more than 50% of the fecal radioactivity found in the monkeys dosed with 1,2,3,5-TeCB. The fecal metabolites were identified in both groups. No metabolites were detected in the feces of monkeys dosed with 1,2,4,5-TeCB. While the fecal route represented the major route of excretion for 1,2,3,4-TeCB, the other two isomers were eliminated exclusively in the feces. The above data in the squirrel monkey are different from those obtained with the rat and the rabbit, and demonstrate the different metabolic pathways for the isomers.

  3. 40 CFR 721.10345 - 1,2-Benzenedicarboxylic acid, 1,2-bis(methylcyclohexyl) ester.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...(methylcyclohexyl) ester. 721.10345 Section 721.10345 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10345 1,2-Benzenedicarboxylic acid, 1,2-bis(methylcyclohexyl) ester. (a... 1,2-benzenedicarboxylic acid, 1,2-bis(methylcyclohexyl) ester (PMN P-05-110; CAS No. 27987-25-3)...

  4. 40 CFR 721.10345 - 1,2-Benzenedicarboxylic acid, 1,2-bis(methylcyclohexyl) ester.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...(methylcyclohexyl) ester. 721.10345 Section 721.10345 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10345 1,2-Benzenedicarboxylic acid, 1,2-bis(methylcyclohexyl) ester. (a... 1,2-benzenedicarboxylic acid, 1,2-bis(methylcyclohexyl) ester (PMN P-05-110; CAS No. 27987-25-3)...

  5. 40 CFR 721.10345 - 1,2-Benzenedicarboxylic acid, 1,2-bis(methylcyclohexyl) ester.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...(methylcyclohexyl) ester. 721.10345 Section 721.10345 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10345 1,2-Benzenedicarboxylic acid, 1,2-bis(methylcyclohexyl) ester. (a... 1,2-benzenedicarboxylic acid, 1,2-bis(methylcyclohexyl) ester (PMN P-05-110; CAS No. 27987-25-3)...

  6. NASA budget growth 1-2% in fiscal 1993?

    NASA Astrophysics Data System (ADS)

    Leath, Audrey T.

    1992-04-01

    Senator Barbara Mikulski (D-Md.) presented departing NASA Administrator Richard Truly with a sobering question at a March 25 hearing of the Senate Appropriations VA, HUD, and Independent Agencies subcommittee. Mikulski told Truly that if the so-called budget “firewalls” don't come down so that defense money can be shifted to domestic spending, her subcommittee's budget allocation will not be sufficient to fund President Bush's requests for NASA. The question she posed to Truly was, if the firewalls do not come down, “Do you believe the best appropriations strategy would be to go to a continuing resolution until March of next year … or recommend trying to squeeze the existing requirements into a growth rate of 1-2% and cut programs based on your priorities?” A continuing resolution would mean continuation of funding at current levels.

  7. Vaccine Assistance To Low- And Middle-Income Countries Increased To $3.6 Billion In 2014.

    PubMed

    Haakenstad, Annie; Birger, Maxwell; Singh, Lavanya; Liu, Patrick; Lim, Stephen; Ng, Marie; Dieleman, Joseph L

    2016-02-01

    In the 2012 Global Vaccine Action Plan, development assistance partners committed to providing sustainable financing for vaccines and expanding vaccination coverage to all children in low- and middle-income countries by 2020. To assess progress toward these goals, the Institute for Health Metrics and Evaluation produced estimates of development assistance for vaccinations. These estimates reveal major increases in the assistance provided since 2000. In 2014, $3.6 billion in development assistance for vaccinations was provided for low- and middle-income countries, up from $822 million in 2000. The funding increase was driven predominantly by the establishment of Gavi, the Vaccine Alliance, supported by the Bill & Melinda Gates Foundation and the governments of the United States and United Kingdom. Despite stagnation in total development assistance for health from donors from 2010 onward, development assistance for vaccination has continued to grow.

  8. United States menhaden oil could save billions in U.S. health care costs and improve IQ in children.

    PubMed

    Bibus, Douglas M

    2016-02-01

    The United States menhaden oil annual production is sufficient to supply all of the recommended long chain Omega-3s for Americans over 55 with coronary heart disease (CHD) and pregnant and lactating women. According to a recent study, the utilization of preventable intake levels could potentially save up to $1.7 billion annually in hospital costs alone. In addition, the remaining oil could be used to support a culture of enough Atlantic salmon to provide every pregnant and lactating woman in the U.S. with 8-12 ounces of fish per week, as recommended by the Food and Drug Administration (FDA), throughout the duration of pregnancy and lactation. Based on the FDA's quantitative assessment, this may result in a net increase of IQ by 5.5 points in children and improve their early age verbal development.

  9. Crystalline 1H-1,2,3-triazol-5-ylidenes

    SciTech Connect

    Bertrand, Guy; Gulsado-Barrios, Gregorio; Bouffard, Jean; Donnadieu, Bruno

    2016-08-02

    The present invention provides novel and stable crystalline 1H-1,2,3 triazolium carbenes and metal complexes of 1H-1,2,3 triazolium carbenes. The present invention also provides methods of making 1H-1,2,3 triazolium carbenes and metal complexes of 1H-1,2,3 triazolium carbenes. The present invention also provides methods of using 1H-1,2,3 triazolium carbenes and metal complexes of 1H-1,2,3 triazolium carbenes in catalytic reactions.

  10. Vibrational analysis of 1,2-dichloro-2-methylpropane and 1,2-dibromo-2-methylpropane

    NASA Astrophysics Data System (ADS)

    Crowder, G. A.; Richardson, Mary Townsend

    1982-02-01

    Liquid-state IR and Raman spectra and solid-state IR spectra have been obtained for 1,2-dichloro-2-methylpropane and l,2-dibromo-2-methylpropane. Carbon-halogen stretching bands are observed in the liquid-state spectrum of the dichloro compound at 751, 725, 624 and 574 cm -1 and at 677, 640, 551 and 507 cm -1 in the liquid-state spectrum of the dibromo compound. Both compounds exist as P CTt HHH and P XT XHH conformations in the liquid, but only the P XT XHH conformer is present for each in the crystalline solid. Further Interpretation of the spectra was aided by normal coordinate calculations.

  11. CETA's $11 Billion

    ERIC Educational Resources Information Center

    Hersher, Judy

    1978-01-01

    The Comprehensive Employment and Training Act (CETA) is now before Congress for review and reenactment. This article examines previous CETA program efforts and the new provisions intended to target jobs and training to the most disadvantaged in terms of income and length of unemployment. (Author/AM)

  12. Developing a Billion Leaders

    ERIC Educational Resources Information Center

    Gergen, Christopher; Rego, Lyndon; Wright, Joel

    2014-01-01

    Intentionally developing the leadership capacity of all students is a necessary requirement for schools around the world. The Center for Creative Leadership in Greensboro, N.C., has been at the center of this work and presents three schools as examples: Ravenscroft School in Raleigh, N.C., the African Leadership Academy in Johannesburg, South…

  13. Rh-Catalyzed Asymmetric Hydrogenation of 1,2-Dicyanoalkenes.

    PubMed

    Li, Meina; Kong, Duanyang; Zi, Guofu; Hou, Guohua

    2017-01-06

    A highly efficient enantioselective hydrogenation of 1,2-dicyanoalkenes catalyzed by the complex of rhodium and f-spiroPhos has been developed. A series of 1,2-dicyanoalkenes were successfully hydrogenated to the corresponding chiral 1,2-dicyanoalkanes under mild conditions with excellent enantioselectivities (up to 98% ee). This methodology provides efficient access to the asymmetric synthesis of chiral diamines.

  14. Acyl migration kinetics of vegetable oil 1,2-diacylglycerols

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The acyl migration kinetics of long-chain 1,2-diacylglycerol (1,2-DAG) to form 1,3-diacylglycerol (1,3-DAG) over the temperature range of 25 to 80 degrees Celsius were examined using proton NMR spectroscopy. The 1,2-DAG mole fraction of 0.32 at equilibrium was found to be insensitive to temperature...

  15. 43 CFR 3471.1-2 - Land description in lease.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Land description in lease. 3471.1-2 Section 3471.1-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND... Coal Management Provisions and Limitations § 3471.1-2 Land description in lease. (a) All...

  16. 43 CFR 3430.1-2 - Commercial quantities defined.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Commercial quantities defined. 3430.1-2 Section 3430.1-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND... Leases § 3430.1-2 Commercial quantities defined. For the purpose of § 3430.1-1 of this title,...

  17. 45 CFR 1216.1-2 - Applicability of this part.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Applicability of this part. 1216.1-2 Section 1216.1-2 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE NONDISPLACEMENT OF EMPLOYED WORKERS AND NONIMPAIRMENT OF CONTRACTS FOR SERVICE § 1216.1-2 Applicability of this part. (a)...

  18. 43 CFR § 2812.1-2 - Contents.

    Code of Federal Regulations, 2010 CFR

    2015-10-01

    ... 43 Public Lands: Interior 2 2015-10-01 2015-10-01 false Contents. § 2812.1-2 Section § 2812.1-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT... Coos Bay Revested Lands § 2812.1-2 Contents. (a) An individual applicant and each member of...

  19. State Implementation and Perceptions of Title I School Improvement Grants under the Recovery Act: One Year Later

    ERIC Educational Resources Information Center

    McMurrer, Jennifer; McIntosh, Shelby

    2012-01-01

    The American Recovery and Reinvestment Act of 2009 (ARRA), also known as the stimulus package, appropriated $100 billion for education and included $3 billion for school improvement grants (SIGs) to help reform low-performing schools. This amount was in addition to the $546 million provided by the regular fiscal year 2009 appropriations bill for…

  20. Reaction of pyrido(1,2-a)benzimidazole and tetrahydropyrido(1,2-a)benzimidazole with acetylenedicarboxylic ester

    SciTech Connect

    Prostakov, N.S.; Varlamov, A.V.; Shendrik, I.V.; Krapivko, A.P.; Golovtsov, N.I.

    1986-08-01

    Previously unknown polynuclear condensed systems with bridgehead nitrogen atoms have been obtained by treating acetylenedicarboxylic ester with pyrido(1,2-a)benzimidazole and tetrahydropyrido(1,2-a)benzimidazole.

  1. First principles prediction of a morphotropic phase boundary in the Bi(Zn1/2Ti1/2)O3-(Bi1/2Sr1/2)(Zn1/2Nb1/2)O3 alloy

    SciTech Connect

    Cooper, Valentino R; Henry, Asegun S; Takagi, Shigeyuki M; Singh, David J

    2011-01-01

    The magnitude and direction of polarization within alloys of the tetragonally distorted Bi(Zn1/2Ti1/2)O3 (BZT) and the rhombohedrally oriented Bi1/2Sr1/2Zn1/2Nb1/2O3 (BSZN) are explored using density functional theory. For compositions with 50% of BZT, we find that the polarization points mainly along the [001] direction. Conversely, for low concentrations of BZT the polarization is rhombohedrally oriented. Based on these results we propose a phase diagram with a possible monoclinc phase between 25% and 50 % BZT where this material may have a useful piezoelectric response.

  2. Word Criticality Analysis. MOS: 31V. Skill Levels 1 & 2.

    DTIC Science & Technology

    1981-09-01

    336,1 2- 347 . 1 2-17,4 -371.12-310#t2 2-Mo1, 2- 34411 2 1-SO 2-311.l 2-333,1 2-321, 2-337,1 2-336,2 2-376,4 2-3?1,5 2-368,3 0Wt,1 3 Abk.KP.IL 2-34, T 2 2...34 -r---2-3 M, Io 3 KX kVu 0.&0 2-337,2 2-321.1 2-368,1 2-343.2 2-347,2 2-31 , 1 2-370. 1 2- 186, 1 2-371. 1 3 LCLP 2-3483 2- 347 *4 2-335,3 _ 2-3209 1 2...DIT CINTEIL HUIME WEJ UNITED STATES ARM~Y TRAIIN~G AN~D DOCTRINE COi’JLAifD FORT L1OME, VIRGINIA 23651 ATOP ~~ ~ ~ ~ ~ ~ ~ .Zo 10- ./8 dte . *u~ -Wil*.h~.,.I ATE

  3. Assessing Progress in Reducing the At-Risk Population after 13 Years of the Global Programme to Eliminate Lymphatic Filariasis

    PubMed Central

    Hooper, Pamela J.; Chu, Brian K.; Mikhailov, Alexei; Ottesen, Eric A.; Bradley, Mark

    2014-01-01

    Background In 1997, the World Health Assembly adopted Resolution 50.29, committing to the elimination of lymphatic filariasis (LF) as a public health problem, subsequently targeted for 2020. The initial estimates were that 1.2 billion people were at-risk for LF infection globally. Now, 13 years after the Global Programme to Eliminate Lymphatic Filariasis (GPELF) began implementing mass drug administration (MDA) against LF in 2000—during which over 4.4 billion treatments have been distributed in 56 endemic countries—it is most appropriate to estimate the impact that the MDA has had on reducing the population at risk of LF. Methodology/Principal Findings To assess GPELF progress in reducing the population at-risk for LF, we developed a model based on defining reductions in risk of infection among cohorts of treated populations following each round of MDA. The model estimates that the number of people currently at risk of infection decreased by 46% to 789 million through 2012. Conclusions/Significance Important progress has been made in the global efforts to eliminate LF, but significant scale-up is required over the next 8 years to reach the 2020 elimination goal. PMID:25411843

  4. Teaching Strategies for American Literature 1, 2 and Advanced American Literature 1, 2.

    ERIC Educational Resources Information Center

    Barr, Mary A.; Theodore, Maria E.

    This guide presents teaching strategies for using the basic texts adopted for American literature study in two different year-long courses. Included are the rationale, course objectives, course outline, suggested units and activities, and individualized projects using media for "American Literature, Chronologically Speaking," and the rationale,…

  5. The VIMOS VLT Deep Survey: Final Public Release of ~ 35 000 Galaxies and Active Galactic Nuclei Covering 13 Billion Years of Evolution

    NASA Astrophysics Data System (ADS)

    Le Fèvre, O.; Adami, C.; Arnouts, S.; Bardelli, S.; Bolzonella, M.; Bondi, M.; Bongiorno, A.; Bottini, D.; Cappi, A.; Cassata, P.; Charlot, S.; Ciliegi, P.; Contini, T.; Cucciati, O.; de la Torre, S.; Foucaud, S.; Franzetti, P.; Garilli, B.; Gavignaud, I.; Guzzo, L.; Ilbert, O.; Iovino, A.; Le Brun, V.; Lemaux, B.; López-Sanjuan, C.; Maccagni, D.; McCracken, H. J.; Marano, B.; Marinoni, C.; Mazure, A.; Mellier, Y.; Merighi, R.; Merluzzi, P.; Moreau, C.; Paltani, S.; Pellò, R.; Pollo, A.; Pozzetti, L.; Scaramella, R.; Scodeggio, M.; Tasca, L.; Tresse, L.; Vergani, D.; Vettolani, G.; Zamorani, G.; Zanichelli, A.; Zucca, E.

    2014-03-01

    The VIMOS VLT Deep Survey (VVDS) final and public data release offers an excellent opportunity to revisit galaxy evolution with a sample of 35 016 galaxies and active galactic nuclei covering the redshift range 0 < z < 6.7. The VVDS includes three tiered surveys, the wide, deep and ultra-deep surveys, covering up to 8.7 square degrees, and each magnitude-selected with limits iAB = 22.5, 24 and 24.75 respectively. The VVDS redshifts, spectra, and all associated multi-wavelength data are available at http://cesam.lam.fr/vvds. The highlights and scientific legacy of the VVDS are summarised.

  6. GALAXY EVOLUTION. An over-massive black hole in a typical star-forming galaxy, 2 billion years after the Big Bang.

    PubMed

    Trakhtenbrot, Benny; Urry, C Megan; Civano, Francesca; Rosario, David J; Elvis, Martin; Schawinski, Kevin; Suh, Hyewon; Bongiorno, Angela; Simmons, Brooke D

    2015-07-10

    Supermassive black holes (SMBHs) and their host galaxies are generally thought to coevolve, so that the SMBH achieves up to about 0.2 to 0.5% of the host galaxy mass in the present day. The radiation emitted from the growing SMBH is expected to affect star formation throughout the host galaxy. The relevance of this scenario at early cosmic epochs is not yet established. We present spectroscopic observations of a galaxy at redshift z = 3.328, which hosts an actively accreting, extremely massive BH, in its final stages of growth. The SMBH mass is roughly one-tenth the mass of the entire host galaxy, suggesting that it has grown much more efficiently than the host, contrary to models of synchronized coevolution. The host galaxy is forming stars at an intense rate, despite the presence of a SMBH-driven gas outflow.

  7. The evolution of the [O II], H β and [O III] emission line luminosity functions over the last nine billions years

    NASA Astrophysics Data System (ADS)

    Comparat, Johan; Zhu, Guangtun; Gonzalez-Perez, Violeta; Norberg, Peder; Newman, Jeffrey; Tresse, Laurence; Richard, Johan; Yepes, Gustavo; Kneib, Jean-Paul; Raichoor, Anand; Prada, Francisco; Maraston, Claudia; Yèche, Christophe; Delubac, Timothée; Jullo, Eric

    2016-09-01

    Emission line galaxies are one of the main tracers of the large-scale structure to be targeted by the next-generation dark energy surveys. To provide a better understanding of the properties and statistics of these galaxies, we have collected spectroscopic data from the VVDS and DEEP2 deep surveys and estimated the galaxy luminosity functions (LFs) of three distinct emission lines, [O II}] (λ λ 3726,3729) (0.5 < z < 1.3), Hβ (λ4861) (0.3 < z < 0.8) and [O {III}] (λ 5007) (0.3 < z < 0.8). Our measurements are based on 35 639 emission line galaxies and cover a volume of ˜107 Mpc3. We present the first measurement of the Hβ LF at these redshifts. We have also compiled LFs from the literature that were based on independent data or covered different redshift ranges, and we fit the entire set over the whole redshift range with analytic Schechter and Saunders models, assuming a natural redshift dependence of the parameters. We find that the characteristic luminosity (L*) and density (φ*) of all LFs increase with redshift. Using the Schechter model over the redshift ranges considered, we find that, for [O {II}] emitters, the characteristic luminosity L*(z = 0.5) = 3.2 × 1041 erg s-1 increases by a factor of 2.7 ± 0.2 from z = 0.5 to 1.3; for Hβ emitters L*(z = 0.3) = 1.3 × 1041 erg s-1 increases by a factor of 2.0 ± 0.2 from z = 0.3 to 0.8; and for [O {III}] emitters L*(z = 0.3) = 7.3 × 1041 erg s-1 increases by a factor of 3.5 ± 0.4 from z = 0.3 to 0.8.

  8. A TALE OF DWARFS AND GIANTS: USING A z = 1.62 CLUSTER TO UNDERSTAND HOW THE RED SEQUENCE GREW OVER THE LAST 9.5 BILLION YEARS

    SciTech Connect

    Rudnick, Gregory H.; Tran, Kim-Vy; Papovich, Casey; Momcheva, Ivelina; Willmer, Christopher

    2012-08-10

    We study the red sequence in a cluster of galaxies at z = 1.62 and follow its evolution over the intervening 9.5 Gyr to the present day. Using deep YJK{sub s} imaging with the HAWK-I instrument on the Very Large Telescope, we identify a tight red sequence and construct its rest-frame i-band luminosity function (LF). There is a marked deficit of faint red galaxies in the cluster that causes a turnover in the LF. We compare the red-sequence LF to that for clusters at z < 0.8, correcting the luminosities for passive evolution. The shape of the cluster red-sequence LF does not evolve between z = 1.62 and z = 0.6 but at z < 0.6 the faint population builds up significantly. Meanwhile, between z = 1.62 and 0.6 the inferred total light on the red sequence grows by a factor of {approx}2 and the bright end of the LF becomes more populated. We construct a simple model for red-sequence evolution that grows the red sequence in total luminosity and matches the constant LF shape at z > 0.6. In this model the cluster accretes blue galaxies from the field whose star formation is quenched and who are subsequently allowed to merge. We find that three to four mergers among cluster galaxies during the 4 Gyr between z = 1.62 and z = 0.6 match the observed LF evolution between the two redshifts. The inferred merger rate is consistent with other studies of this cluster. Our result supports the picture that galaxy merging during the major growth phase of massive clusters is an important process in shaping the red-sequence population at all luminosities.

  9. Corrigendum to "A redox-stratified ocean 3.2 billion years ago" [Earth Planet. Sci. Lett. 430 (2015) 43-53

    NASA Astrophysics Data System (ADS)

    Satkoski, Aaron M.; Beukes, Nicolas J.; Li, Weiqiang; Beard, Brian L.; Johnson, Clark M.

    2017-02-01

    The authors have discovered a calculation error in the concentration data for U, Th and Pb. This error does not affect any measured isotopic compositions: 206Pb/204Pb, 207Pb/204Pb, 238U/204Pb, 232Th/204Pb, and 235U/204Pb; these all remain the same. None of the Fe isotope data are affected. Hence, none of the conclusions for open or closed-system U-Th-Pb behavior are affected, nor the conclusions of a redox gradient between shallow- and deep-water U contents. The magnitude of the shallow- and deep-water U content contrast remains the same, where U contents in shallow seawater are estimated to have been about three times that of deep-water samples.

  10. DOD, State, and USAID Obligated Over $17.7 Billion to About 7,000 Contractors and Other Entities for Afghanistan Reconstruction During Fiscal years 2007-2009

    DTIC Science & Technology

    2010-10-27

    number. 1. REPORT DATE 27 OCT 2010 2. REPORT TYPE 3 . DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE DOD, State, and USAID...2009 ............................................................................... 7 Table 3 : Contractors and Obligations Made Against Afghanistan...combat troops. 3 To determine the reliability of the data provided, we met with officials, including contracting and financial officers, from DOD

  11. A Tale of Dwarfs and Giants: Using a z = 1.62 Cluster to Understand How the Red Sequence Grew over the Last 9.5 Billion Years

    NASA Astrophysics Data System (ADS)

    Rudnick, Gregory H.; Tran, Kim-Vy; Papovich, Casey; Momcheva, Ivelina; Willmer, Christopher

    2012-08-01

    We study the red sequence in a cluster of galaxies at z = 1.62 and follow its evolution over the intervening 9.5 Gyr to the present day. Using deep YJKs imaging with the HAWK-I instrument on the Very Large Telescope, we identify a tight red sequence and construct its rest-frame i-band luminosity function (LF). There is a marked deficit of faint red galaxies in the cluster that causes a turnover in the LF. We compare the red-sequence LF to that for clusters at z < 0.8, correcting the luminosities for passive evolution. The shape of the cluster red-sequence LF does not evolve between z = 1.62 and z = 0.6 but at z < 0.6 the faint population builds up significantly. Meanwhile, between z = 1.62 and 0.6 the inferred total light on the red sequence grows by a factor of ~2 and the bright end of the LF becomes more populated. We construct a simple model for red-sequence evolution that grows the red sequence in total luminosity and matches the constant LF shape at z > 0.6. In this model the cluster accretes blue galaxies from the field whose star formation is quenched and who are subsequently allowed to merge. We find that three to four mergers among cluster galaxies during the 4 Gyr between z = 1.62 and z = 0.6 match the observed LF evolution between the two redshifts. The inferred merger rate is consistent with other studies of this cluster. Our result supports the picture that galaxy merging during the major growth phase of massive clusters is an important process in shaping the red-sequence population at all luminosities. Based on observations obtained at the European Southern Observatory using the ESO Very Large Telescope on Cerro Paranal through ESO program 386.A-0514(A).

  12. Sulfur isotope mass-independent fractionation in impact deposits of the 3.2 billion-year-old Mapepe Formation, Barberton Greenstone Belt, South Africa

    NASA Astrophysics Data System (ADS)

    van Zuilen, M. A.; Philippot, P.; Whitehouse, M. J.; Lepland, A.

    2014-10-01

    Theoretical and experimental studies have shown that atmospheric SO2 isotopologue self-shielding effects in the 190-220 nm region of the solar spectrum are the likely cause for mass independent fractionation of sulfur isotopes (S-MIF). The main products of this photochemical reaction - SO3 and S0 - typically define a compositional array of ca. Δ33S/δ34S = 0.06-0.14. This is at odds with the generally observed trend in Archean sulfides, which broadly defines an array of ca. Δ33S/δ34S = 0.9. Various explanations have been proposed, including a diminution of δ34S caused by chemical and biogenic mass-dependent fractionation of sulfur isotopes (S-MDF), mixing with photolytic products produced during felsic volcanic events, or partial blocking of the low-wavelength part of the spectrum due to the presence of reduced atmospheric gases or an organic haze. Early in Earth history large meteorite impacts would have ejected dust and gas clouds into the atmosphere that shielded solar radiation and affected global climate. It is thus likely that at certain time intervals of high meteorite flux the atmosphere was significantly perturbed, having an effect on atmospheric photochemistry and possibly leaving anomalous sulfur isotopic signatures in the rock record. Here we describe the sulfur isotopic signatures in sulfides of spherule beds S2, S3 and S4 of the Barberton Greenstone Belt, South Africa. In particular, in spherule bed S3 - and to a lesser extent S4 - a trend of ca. Δ33S/δ34S = 0.23 is observed that closely follows the expected trend for SO2-photolysis in the 190-220 nm spectral range. This suggests that an impact dust cloud (deposited as spherule beds), which sampled the higher region of the atmosphere, specifically incorporated products of SO2 photolysis in the 190-220 nm range, and blocked photochemical reactions at higher wavelengths (250-330 nm band). By implication, the generally observed Archean trend appears to be the result of mixing of different MIF-S sources arising from a variety of photochemical reactions that took place in the lower part of the atmosphere.

  13. 1.8 billion years of fluid-crust interaction: A zircon oxygen isotope record for the lower crust, western Churchill Province, Canadian Shield

    NASA Astrophysics Data System (ADS)

    Petts, Duane C.; Moser, Desmond E.; Longstaffe, Frederick J.; Davis, William J.; Stern, Richard A.

    2014-04-01

    The western Churchill Province of the Canadian Shield experienced a prolonged and complex formation history (ca. 4.04 to 1.70 Ga), with evidence for multiple episodes of orogenesis and regional magmatic activity. Here we report on the oxygen isotopic compositions of garnet and zircon recovered from lower crustal xenoliths, which have U-Pb ages between ca. 3.5 and 1.7 Ga. Overall, zircon from four metabasite xenoliths from the Rankin Inlet sample suite have δ18O values ranging from + 5.5 to + 8.6‰. Zircon from three metatonalite/anorthosite xenoliths and five metabasite xenoliths from the Repulse Bay sample suite have δ18O values of + 5.6 to + 8.3‰. High δ18O values (> + 6.0‰) for the oldest igneous zircon cores (ca. 3.5 Ga and 3.0-2.6 Ga) indicate that their metatonalite/anorthosite protolith magmas were generated from, or had assimilated, supracrustal rocks that interacted previously with surface-derived fluids. Igneous zircon cores (ca. 2.9-2.6 Ga) from one metabasite xenolith have δ18O values of + 5.6 to + 6.4‰, which suggests a formation from a mantle-derived basaltic/gabbroic magma. Metamorphic zircon cores (ca. 2.0-1.9 Ga) from one metabasite xenolith commonly have δ18O values between + 6.0 and + 6.3‰, which is indicative of a basalt/gabbro protolith and localized reworking of the lower crust caused by regional-scale plate convergence. The wide range of δ18O values (+ 5.5 to + 8.3‰) for ca. 1.75-1.70 Ga metamorphic zircon rims (identified in all xenoliths) indicates regional transient heating and reworking of mantle- and supracrustal-derived crust, induced by magmatic underplating along the crust-mantle boundary.

  14. Galaxy Zoo: an independent look at the evolution of the bar fraction over the last eight billion years from HST-COSMOS

    NASA Astrophysics Data System (ADS)

    Melvin, Thomas; Masters, Karen; Lintott, Chris; Nichol, Robert C.; Simmons, Brooke; Bamford, Steven P.; Casteels, Kevin R. V.; Cheung, Edmond; Edmondson, Edward M.; Fortson, Lucy; Schawinski, Kevin; Skibba, Ramin A.; Smith, Arfon M.; Willett, Kyle W.

    2014-03-01

    We measure the redshift evolution of the bar fraction in a sample of 2380 visually selected disc galaxies found in Cosmic Evolution Survey (COSMOS) Hubble Space Telescope (HST) images. The visual classifications used both to identify the disc sample and to indicate the presence of stellar bars were provided by citizen scientists via the Galaxy Zoo: Hubble (GZH) project. We find that the overall bar fraction decreases by a factor of 2, from 22 ± 5 per cent at z = 0.4 (tlb = 4.2 Gyr) to 11 ± 2 per cent at z = 1.0 (tlb = 7.8 Gyr), consistent with previous analysis. We show that this decrease, of the strong bar fraction in a volume limited sample of massive disc galaxies [stellar mass limit of log (M⋆/M⊙) ≥ 10.0], cannot be due to redshift-dependent biases hiding either bars or disc galaxies at higher redshifts. Splitting our sample into three bins of mass we find that the decrease in bar fraction is most prominent in the highest mass bin, while the lower mass discs in our sample show a more modest evolution. We also include a sample of 98 red disc galaxies. These galaxies have a high bar fraction (45 ± 5 per cent), and are missing from other COSMOS samples which used SED fitting or colours to identify high-redshift discs. Our results are consistent with a picture in which the evolution of massive disc galaxies begins to be affected by slow (secular) internal process at z ˜ 1. We discuss possible connections of the decrease in bar fraction to the redshift, including the growth of stable disc galaxies, mass evolution of the gas content in disc galaxies, as well as the mass-dependent effects of tidal interactions.

  15. A 4.2 billion year old impact basin on the Moon: U-Pb dating of zirconolite and apatite in lunar melt rock 67955

    NASA Astrophysics Data System (ADS)

    Norman, Marc D.; Nemchin, Alexander A.

    2014-02-01

    A sharp rise in the flux of asteroid-size bodies traversing the inner Solar System at 3.9 Ga has become a central tenet of recent models describing planetary dynamics and the potential habitability of early terrestrial environments. The prevalence of ˜3.9 Ga crystallization ages for lunar impact-melt breccias and U-Pb isotopic compositions of lunar crustal rocks provide the primary evidence for a short-lived, cataclysmic episode of late heavy bombardment at that time. Here we report U-Pb isotopic compositions of zirconolite and apatite in coarse-grained lunar melt rock 67955, measured by ion microprobe, that date a basin-scale impact melting event on the Moon at 4.22±0.01 Ga followed by entrainment within lower grade ejecta from a younger basin approximately 300 million yr later. Significant impacts prior to 3.9 Ga are also recorded by lunar zircons although the magnitudes of those events are difficult to establish. Other isotopic evidence such as 40Ar-39Ar ages of granulitic lunar breccias, regolith fragments, and clasts extracted from fragmental breccias, and Re-Os isotopic compositions of lunar metal is also suggestive of impact-related thermal events in the lunar crust during the period 4.1-4.3 Ga. We conclude that numerous large impactors hit the Moon prior to the canonical 3.9 Ga cataclysm, that some of those pre-cataclysm impacts were similar in size to the younger lunar basins, and that the oldest preserved lunar basins are likely to be significantly older than 3.9 Ga. This provides sample-based support for dynamical models capable of producing older basins on the Moon and discrete populations of impactors. An extended period of basin formation implies a less intense cataclysm at 3.9 Ga, and therefore a better opportunity for preservation of early habitable niches and Hadean crust on the Earth. A diminished cataclysm at 3.9 Ga suggests that the similarity in the age of the oldest terrestrial continental crust with the canonical lunar cataclysm is likely to be coincidental with no genetic significance.

  16. LoCuSS: THE STEADY DECLINE AND SLOW QUENCHING OF STAR FORMATION IN CLUSTER GALAXIES OVER THE LAST FOUR BILLION YEARS

    SciTech Connect

    Haines, C. P.; Pereira, M. J.; Egami, E.; Rawle, T. D.; Smith, G. P.; Sanderson, A. J. R.; Babul, A.; Finoguenov, A.; Merluzzi, P.; Busarello, G.; Okabe, N.

    2013-10-01

    We present an analysis of the levels and evolution of star formation activity in a representative sample of 30 massive galaxy clusters at 0.15 < z < 0.30 from the Local Cluster Substructure Survey, combining wide-field Spitzer/MIPS 24 μm data with extensive spectroscopy of cluster members. The specific SFRs of massive (M > or approx. 10{sup 10} M{sub ☉}) star-forming cluster galaxies within r{sub 200} are found to be systematically ∼28% lower than their counterparts in the field at fixed stellar mass and redshift, a difference significant at the 8.7σ level. This is the unambiguous signature of star formation in most (and possibly all) massive star-forming galaxies being slowly quenched upon accretion into massive clusters, their star formation rates (SFRs) declining exponentially on quenching timescales in the range 0.7-2.0 Gyr. We measure the mid-infrared Butcher-Oemler effect over the redshift range 0.0-0.4, finding rapid evolution in the fraction (f{sub SF}) of massive (M{sub K} < – 23.1) cluster galaxies within r{sub 200} with SFRs > 3 M{sub ☉} yr{sup –1}, of the form f{sub SF}∝(1 + z){sup 7.6±1.1}. We dissect the origins of the Butcher-Oemler effect, revealing it to be due to the combination of a ∼3 × decline in the mean specific SFRs of star-forming cluster galaxies since z ∼ 0.3 with a ∼1.5 × decrease in number density. Two-thirds of this reduction in the specific SFRs of star-forming cluster galaxies is due to the steady cosmic decline in the specific SFRs among those field galaxies accreted into the clusters. The remaining one-third reflects an accelerated decline in the star formation activity of galaxies within clusters. The slow quenching of star formation in cluster galaxies is consistent with a gradual shut down of star formation in infalling spiral galaxies as they interact with the intracluster medium via ram-pressure stripping or starvation mechanisms. The observed sharp decline in star formation activity among cluster galaxies since z ∼ 0.4 likely reflects the increased susceptibility of low-redshift spiral galaxies to gas removal mechanisms as their gas surface densities decrease with time. We find no evidence for the build-up of cluster S0 bulges via major nuclear starburst episodes.

  17. In situ Raman spectroscopy and confocal microscopy of 2.5-billion-year-old fossil microorganisms: viable nondestructive techniques for the study of returned Martian samples

    NASA Astrophysics Data System (ADS)

    Calvin, W. M.; Fraeman, A.; Ehlmann, B. L.; Lautze, N. C.

    2014-12-01

    The Humu'ula Groundwater Research Project (HGRP) drilled their first continuously-cored hole in the saddle region of the big island of Hawaii in March of 2013. Temperatures at the bottom of the hole were unexpectedly high and reached over 100C. The core traverses various lava flows, representing the shield-building phase of the island and the lithology is dominantly basalt with varying amounts of plagioclase and olivine phenocrysts. Logging of the core noted that discontinuous alteration became prevalent starting at ~ 1 km depth. In May of 2015 we collected 780 infrared spectra of the core from depths of 0.97 to 1.76 km using our portable field spectrometer with a contact probe and field of view of 10 mm. Many of the spectra are unaltered, showing mafic mineralogy (augite or augite with olivine). Minerals from aqueous alteration include clinochlore, micaceous minerals likely mixed with other common phyllic alteration products, and three groups of spectral types associated with zeolites. This suite of minerals suggests alteration was initiated from higher temperature and moderate pH fluids. Based on the field reconnaissance spectroscopy, 25 sections were cut that represent the alteration diversity for thin section and subsequent detailed petrologic analyses. Eight of these sections were examined using the Ultra-Compact Imaging Spectrometer (UCIS) prototype instrument at the Jet Propulsion Laboratory. UCIS collects spectra at 80 μm / pixel and identifies the same alteration mineralogy as the bulk samples, but clearly shows that the alteration occurs in veins and vugs. Unaltered olivine and pyroxene phenocrysts occur in the groundmass adjacent to highly altered vugs, and are preserved throughout the section surveyed. Given the limited alteration and abundant preservation of olivine to depths of 1.5 km, the core may be representative of alteration in moderate pH environments on Mars, where unaltered basaltic materials occur in close proximity to alteration products. Similar alteration might occur at the surface with limited water exposure, or in the subsurface where materials are subsequently exhumed through impact processes.

  18. The economic downturn and its lingering effects reduced medicare spending growth by $4 billion in 2009-12.

    PubMed

    Dranove, David; Garthwaite, Craig; Ody, Christopher

    2015-08-01

    Previous work has found a strong connection between the most recent economic recession and reductions in private health spending. However, the effect of economic downturns on Medicare spending is less clear. In contrast to studies involving earlier time periods, our study found that when the macroeconomy slowed during the Great Recession of 2007-09, so did Medicare spending growth. A small (14 percent) but significant share of the decline in Medicare spending growth from 2009 to 2012 relative to growth from 2004 to 2009 can be attributed to lingering effects of the recession. Absent the economic downturn, Medicare spending would have been $4 billion higher in 2009-12. A major reason for the relatively small impact of the macroeconomy is the relative lack of labor-force participation among people ages sixty-five and older. We estimate that if they had been working at the same rate as the nonelderly before the recession, the effect of the downturn on Medicare spending growth would have been twice as large.

  19. Malthus is still wrong: we can feed a world of 9-10 billion, but only by reducing food demand.

    PubMed

    Smith, Pete

    2015-08-01

    In 1798, Thomas Robert Malthus published 'An essay on the principle of population' in which he concluded that: 'The power of population is so superior to the power of the earth to produce subsistence for man, that premature death must in some shape or other visit the human race.' Over the following century he was criticised for underestimating the potential for scientific and technological innovation to provide positive change. Since then, he has been proved wrong, with a number of papers published during the past few decades pointing out why he has been proved wrong so many times. In the present paper, I briefly review the main changes in food production in the past that have allowed us to continue to meet ever growing demand for food, and I examine the possibility of these same innovations delivering food security in the future. On the basis of recent studies, I conclude that technological innovation can no longer be relied upon to prove Malthus wrong as we strive to feed 9-10 billion people by 2050. Unless we are prepared to accept a wide range of significant, undesirable environmental consequences, technology alone cannot provide food security in 2050. Food demand, particularly the demand for livestock products, will need to be managed if we are to continue to prove Malthus wrong into the future.

  20. Multi million-to-Billion Atom Molecular Dynamics Simulations of Cavitation-Induced Damage on a Silica Slab

    NASA Astrophysics Data System (ADS)

    Shekhar, Adarsh; Nomura, Ken-Ichi; Kalia, Rajiv; Nakano, Aiichiro; Vashishta, Priya

    2012-02-01

    Cavitation bubble collapse causes severe damage to materials. For example, cavitation erosion is a major threat to the safety of nuclear power plants. The cavitation bubbles may also be utilized for preventing stress corrosion cracking with water jet peening technology. We have performed multi million-to-billion atoms molecular dynamics simulations to investigate the shock-induced cavitation damage mechanism on an amorphous silica slab in water. The system consists of a 60nm thick silica slab immersed in water in an MD box of dimension 285 x 200 x 200 nm3. A nanobubble is created by removing water molecules within a sphere of radius 100 nm. To apply a planar shock, we assign a uniform particle velocity vp on the entire system towards a planar momentum mirror. We have performed the simulation with two kinds of bubbles, an empty bubble and a bubble filled with inert gas. The simulation results reveal nanojet formation during bubble collapse causing damage on the silica surface; however, the damage was significantly reduced in the case of the filled bubble. We will discuss the effect of the presence of inter gas inside the nanobubble on the pressure distribution, the extent of damage, and collapse behavior corresponding the shock front.

  1. Impacts of a 32-billion-gallon bioenergy landscape on land and fossil fuel use in the US

    NASA Astrophysics Data System (ADS)

    Hudiburg, Tara W.; Wang, Weiwei; Khanna, Madhu; Long, Stephen P.; Dwivedi, Puneet; Parton, William J.; Hartman, Melannie; Delucia, Evan H.

    2016-01-01

    Sustainable transportation biofuels may require considerable changes in land use to meet mandated targets. Understanding the possible impact of different policies on land use and greenhouse gas emissions has typically proceeded by exploring either ecosystem or economic modelling. Here we integrate such models to assess the potential for the US Renewable Fuel Standard to reduce greenhouse gas emissions from the transportation sector through the use of cellulosic biofuels. We find that 2022 US emissions are decreased by 7.0 ± 2.5% largely through gasoline displacement and soil carbon storage by perennial grasses. If the Renewable Fuel Standard is accompanied by a cellulosic biofuel tax credit, these emissions could be reduced by 12.3 ± 3.4%. Our integrated approach indicates that transitioning to cellulosic biofuels can meet a 32-billion-gallon Renewable Fuel Standard target with negligible effects on food crop production, while reducing fossil fuel use and greenhouse gas emissions. However, emissions savings are lower than previous estimates that did not account for economic constraints.

  2. Fiscal Year 1996 Annual Report and Five-Year (1996-2000) Strategic Investment Plan

    DTIC Science & Technology

    1996-03-01

    Monitor Petroleum, Oil , Lubricants Peroxone Oxidation Pilot System Pollution Prevention Thrust Area Parts Per Billion Platform Transmitting...Ground Combat Center, Twenty-nine Palms , California. Totally these systems are reducing carbon dioxide emissions by 287 tons per year, nitrogen oxide...Treatment - Improved Recovery of Free Petroleum, Oils , and Lubricants from Aquifers - Improved Remediation of Groundwater Contaminated with

  3. An 8 1/2-Year Record: Mentally Retarded Workers in the Federal Service.

    ERIC Educational Resources Information Center

    Civil Service Commission, Washington, DC. Bureau of Recruiting and Examining.

    Summarized in this report are efforts employed to secure for mentally retarded persons increased job opportunities in the Federal Service. Before actuating the project, extensive studies and job training programs were conducted, and the information obtained widely disseminated. Services of state vocational rehabilitation departments were used in…

  4. The ATS-5 solar cell experiment after 6-1/2 years in synchronous orbit

    NASA Technical Reports Server (NTRS)

    Anspaugh, B.

    1976-01-01

    Several types of solar cell/coverslide combinations were launched into synchronous orbit. The cells were 2 and 10 ohm-cm crucible-grown silicon with thicknesses of 0.2 and 0.3 mm. Coverslides were fused silica, ranging in thickness from 0.15 to 1.52 mm. The cells were mounted on two panels, one a rigid aluminum honeycomb structure, giving essentially infinite backshielding; the other was a thin Kapton-fiberglass substrate, offering minimal protection to the rear surface of the cells. The current-voltage curves of the cells were measured. Correction of cell electrical output to standard temperature and solar intensity was performed, using empirical radiation-dependent corrections. It is found that the cells on the flexible panel degrade much more rapidly than predicted, while the rigid panel cells follow the predictions fairly well. The anomalous behavior of the flexible panel cells is attributed to the deposition of a contaminant on the cell coverslides.

  5. Liquid effluents 1994 fiscal year work plan: WBS 1.2.2.1

    SciTech Connect

    Ashworth, F.L. Jr.

    1993-08-01

    The program mission is to manage current and future liquid effluent streams in a safe, responsible, cost effective and legally compliant manner. This is achieved through planning and integration, public and stakeholder interaction, definition of requirements for generators and provision of timely treatment, storage, disposal capability, and waste minimization of waste streams where applicable.

  6. Word Criticality Analysis. MOS: 44E. Skill Levels 1 & 2.

    DTIC Science & Technology

    1981-09-01

    78.4 2- 64,1 I GLgKP(Ix 2- 62,1 2- 58,1 1 ’ ’. I fMbs WIUf,D LIaT BY 04GE tfTF .PV. 107? PIGE . 1 GE 2- 79,1 I G1M& 2- 32,1 G(1N)EM2- 17,1 2- 137,1 2...0 2 0 n~ 1 . i , - I - I C5MS WIRD LIST BY PIGE 1Yj’© p𔃻L’ 1177 P.GP 6 j 1 EltL 2- 10,1 2- 18,1 2- 12,1 N1 MI IFV 2- 12.1 2- 66 l 2- 57.2 2- 26,1

  7. The Economic Burden of Vision Loss and Eye Disorders among the United States Population Younger than 40 Years

    PubMed Central

    Wittenborn, John S.; Zhang, Xinzhi; Feagan, Charles W.; Crouse, Wesley L.; Shrestha, Sundar; Kemper, Alex R.; Hoerger, Thomas J.; Saaddine, Jinan B.

    2017-01-01

    Objective To estimate the economic burden of vision loss and eye disorders in the United States population younger than 40 years in 2012. Design Econometric and statistical analysis of survey, commercial claims, and census data. Participants The United States population younger than 40 years in 2012. Methods We categorized costs based on consensus guidelines. We estimated medical costs attributable to diagnosed eye-related disorders, undiagnosed vision loss, and medical vision aids using Medical Expenditure Panel Survey and MarketScan data. The prevalence of vision impairment and blindness were estimated using National Health and Nutrition Examination Survey data. We estimated costs from lost productivity using Survey of Income and Program Participation. We estimated costs of informal care, low vision aids, special education, school screening, government spending, and transfer payments based on published estimates and federal budgets. We estimated quality-adjusted life years (QALYs) lost based on published utility values. Main Outcome Measures Costs and QALYs lost in 2012. Results The economic burden of vision loss and eye disorders among the United States population younger than 40 years was $27.5 billion in 2012 (95% confidence interval, $21.5–$37.2 billion), including $5.9 billion for children and $21.6 billion for adults 18 to 39 years of age. Direct costs were $14.5 billion, including $7.3 billion in medical costs for diagnosed disorders, $4.9 billion in refraction correction, $0.5 billion in medical costs for undiagnosed vision loss, and $1.8 billion in other direct costs. Indirect costs were $13 billion, primarily because of $12.2 billion in productivity losses. In addition, vision loss cost society 215 000 QALYs. Conclusions We found a substantial burden resulting from vision loss and eye disorders in the United States population younger than 40 years, a population excluded from previous studies. Monetizing quality-of-life losses at $50 000 per QALY would

  8. Validation of an evacuated canister method for measuring part-per-billion levels of chemical warfare agent simulants.

    PubMed

    Coffey, Christopher C; LeBouf, Ryan F; Calvert, Catherine A; Slaven, James E

    2011-08-01

    The National Institute for Occupational Safety and Health (NIOSH) research on direct-reading instruments (DRIs) needed an instantaneous sampling method to provide independent confirmation of the concentrations of chemical warfare agent (CWA) simulants. It was determined that evacuated canisters would be the method of choice. There is no method specifically validated for volatile organic compounds (VOCs) in the NIOSH Manual of Analytical Methods. The purpose of this study was to validate an evacuated canister method for sampling seven specific VOCs that can be used as a simulant for CWA agents (cyclohexane) or influence the DRI measurement of CWA agents (acetone, chloroform, methylene chloride, methyl ethyl ketone, hexane, and carbon tetrachloride [CCl4]). The method used 6-L evacuated stainless-steel fused silica-lined canisters to sample the atmosphere containing VOCs. The contents of the canisters were then introduced into an autosampler/preconcentrator using a microscale purge and trap (MPT) method. The MPT method trapped and concentrated the VOCs in the air sample and removed most of the carbon dioxide and water vapor. After preconcentration, the samples were analyzed using a gas chromatograph with a mass selective detector. The method was tested, evaluated, and validated using the NIOSH recommended guidelines. The evaluation consisted of determining the optimum concentration range for the method; the sample stability over 30 days; and the accuracy, precision, and bias of the method. This method meets the NIOSH guidelines for six of the seven compounds (excluding acetone) tested in the range of 2.3-50 parts per billion (ppb), making it suitable for sampling of these VOCs at the ppb level.

  9. New Schools, Overcrowding Relief, and Achievement Gains in Los Angeles--Strong Returns from a $19.5 Billion Investment. Policy Brief 12-2

    ERIC Educational Resources Information Center

    Welsh, William; Coghlan, Erin; Fuller, Bruce; Dauter, Luke

    2012-01-01

    Aiming to relieve overcrowded schools operating on multiple tracks, the Los Angeles Unified School District (LAUSD) has invested more than $19 billion to build 130 new facilities over the past decade. District leaders asked researchers at Berkeley to estimate the achievement effects of this massive initiative--benefits that may stem from entering…

  10. 43 CFR 3472.1-2 - Special leasing qualifications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Special leasing qualifications. 3472.1-2... Lease Qualification Requirements § 3472.1-2 Special leasing qualifications. (a) Each applicant or bidder... compliance with the special leasing qualifications of this subpart. (4)(i) An entity, seeking to qualify...

  11. 43 CFR 3472.1-2 - Special leasing qualifications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Special leasing qualifications. 3472.1-2... Lease Qualification Requirements § 3472.1-2 Special leasing qualifications. (a) Each applicant or bidder... compliance with the special leasing qualifications of this subpart. (4)(i) An entity, seeking to qualify...

  12. 43 CFR 3472.1-2 - Special leasing qualifications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Special leasing qualifications. 3472.1-2... Lease Qualification Requirements § 3472.1-2 Special leasing qualifications. (a) Each applicant or bidder... compliance with the special leasing qualifications of this subpart. (4)(i) An entity, seeking to qualify...

  13. 41 CFR 51-1.2 - Mandatory source priorities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Mandatory source priorities. 51-1.2 Section 51-1.2 Public Contracts and Property Management Other Provisions Relating to... Mandatory source priorities. (a) The JWOD Act mandates that commodities or services on the Procurement...

  14. 36 CFR 1.2 - Applicability and scope.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Applicability and scope. 1.2 Section 1.2 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR GENERAL... administered by the National Park Service; (2) The boundaries of lands and waters administered by the...

  15. 43 CFR 3802.1-2 - When not required.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false When not required. 3802.1-2 Section 3802.1-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT... transported without using mechanized earth moving equipment or tracked vehicles....

  16. 43 CFR 3430.1-2 - Commercial quantities defined.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Commercial quantities defined. 3430.1-2 Section 3430.1-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND... sale of the coal shall exceed the cost of developing the mine and extracting, removing,...

  17. 41 CFR 51-1.2 - Mandatory source priorities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 1 2012-07-01 2009-07-01 true Mandatory source priorities. 51-1.2 Section 51-1.2 Public Contracts and Property Management Other Provisions Relating to Public Contracts COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED 1-GENERAL §...

  18. 41 CFR 51-1.2 - Mandatory source priorities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 1 2014-07-01 2014-07-01 false Mandatory source priorities. 51-1.2 Section 51-1.2 Public Contracts and Property Management Other Provisions Relating to Public Contracts COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED 1-GENERAL §...

  19. 41 CFR 51-1.2 - Mandatory source priorities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 1 2011-07-01 2009-07-01 true Mandatory source priorities. 51-1.2 Section 51-1.2 Public Contracts and Property Management Other Provisions Relating to Public Contracts COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED 1-GENERAL §...

  20. 41 CFR 51-1.2 - Mandatory source priorities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 1 2013-07-01 2013-07-01 false Mandatory source priorities. 51-1.2 Section 51-1.2 Public Contracts and Property Management Other Provisions Relating to Public Contracts COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED 1-GENERAL §...

  1. 43 CFR 3582.1-2 - Hardrock minerals.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Hardrock minerals. 3582.1-2 Section 3582.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL LEASING AREAS National Park Service Areas § 3582.1-2 Hardrock minerals. Except as otherwise specifically provided in this subpart, leasing...

  2. 43 CFR 3582.1-2 - Hardrock minerals.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Hardrock minerals. 3582.1-2 Section 3582.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL LEASING AREAS National Park Service Areas § 3582.1-2 Hardrock minerals. Except as otherwise specifically provided in this subpart, leasing...

  3. 43 CFR 3583.1-2 - Hardrock minerals.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Hardrock minerals. 3583.1-2 Section 3583.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL LEASING AREAS Shasta and Trinity Units of the Whiskeytown-Shasta-Trinity National Recreation Area § 3583.1-2 Hardrock minerals. This subpart governs...

  4. 43 CFR 3583.1-2 - Hardrock minerals.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Hardrock minerals. 3583.1-2 Section 3583.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL LEASING AREAS Shasta and Trinity Units of the Whiskeytown-Shasta-Trinity National Recreation Area § 3583.1-2 Hardrock minerals. This subpart governs...

  5. 43 CFR 3583.1-2 - Hardrock minerals.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Hardrock minerals. 3583.1-2 Section 3583.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL LEASING AREAS Shasta and Trinity Units of the Whiskeytown-Shasta-Trinity National Recreation Area § 3583.1-2 Hardrock minerals. This subpart governs...

  6. 43 CFR 3582.1-2 - Hardrock minerals.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Hardrock minerals. 3582.1-2 Section 3582.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL LEASING AREAS National Park Service Areas § 3582.1-2 Hardrock minerals. Except as otherwise specifically provided in this subpart, leasing...

  7. 43 CFR 3582.1-2 - Hardrock minerals.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Hardrock minerals. 3582.1-2 Section 3582.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL LEASING AREAS National Park Service Areas § 3582.1-2 Hardrock minerals. Except as otherwise specifically provided in this subpart, leasing...

  8. 43 CFR 3583.1-2 - Hardrock minerals.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Hardrock minerals. 3583.1-2 Section 3583.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SPECIAL LEASING AREAS Shasta and Trinity Units of the Whiskeytown-Shasta-Trinity National Recreation Area § 3583.1-2 Hardrock minerals. This subpart governs...

  9. Fermions in d = 1 + 2 dimensions from first principles

    SciTech Connect

    Carrillo-Ruiz, Ma. Georgina; Napsuciale, Mauro

    2006-09-25

    In this work we construct states describing planar electrons ('spin' (1/2) particles with well defined parity) in d = 1 + 2 from first principles and show that they satisfy Dirac equation, which turns out to be the covariant form of the eigenvalue equation for spatial inversion (parity) just like in d = 1 + 3.

  10. 14 CFR 1.2 - Abbreviations and symbols.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Abbreviations and symbols. 1.2 Section 1.2 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION DEFINITIONS DEFINITIONS... indicated airspeed. ICAO means International Civil Aviation Organization. IFR means instrument flight...

  11. 45 CFR 1206.1-2 - Application of this part.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 4 2011-10-01 2011-10-01 false Application of this part. 1206.1-2 Section 1206.1-2 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE GRANTS AND CONTRACTS-SUSPENSION AND TERMINATION AND DENIAL OF APPLICATION FOR REFUNDING Suspension and Termination of Assistance §...

  12. 43 CFR 2201.1-2 - Segregative effect.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Segregative effect. 2201.1-2 Section 2201... Exchanges-Specific Requirements § 2201.1-2 Segregative effect. (a) If a proposal is made to exchange Federal... public land status records. (c) The segregative effect shall terminate upon the occurrence of any of...

  13. 43 CFR 2201.1-2 - Segregative effect.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregative effect. 2201.1-2 Section 2201... Exchanges-Specific Requirements § 2201.1-2 Segregative effect. (a) If a proposal is made to exchange Federal... public land status records. (c) The segregative effect shall terminate upon the occurrence of any of...

  14. 43 CFR 2201.1-2 - Segregative effect.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Segregative effect. 2201.1-2 Section 2201... Exchanges-Specific Requirements § 2201.1-2 Segregative effect. (a) If a proposal is made to exchange Federal... public land status records. (c) The segregative effect shall terminate upon the occurrence of any of...

  15. 43 CFR 2201.1-2 - Segregative effect.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Segregative effect. 2201.1-2 Section 2201... Exchanges-Specific Requirements § 2201.1-2 Segregative effect. (a) If a proposal is made to exchange Federal... public land status records. (c) The segregative effect shall terminate upon the occurrence of any of...

  16. 48 CFR 970.2201-1-2 - Policies.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Policies. 970.2201-1-2... REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Application of Labor Policies 970.2201-1-2 Policies. (a... installations; retention by DOE of absolute authority on all questions of security; and DOE review of...

  17. 43 CFR 3472.1-2 - Special leasing qualifications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Special leasing qualifications. 3472.1-2... Lease Qualification Requirements § 3472.1-2 Special leasing qualifications. (a) Each applicant or bidder... compliance with the special leasing qualifications of this subpart. (4)(i) An entity, seeking to qualify...

  18. 5 CFR 1.2 - Extent of the competitive service.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Extent of the competitive service. 1.2 Section 1.2 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE RULES COVERAGE AND... pursuant to statute or by the Office of Personnel Management (hereafter referred to in this subchapter...

  19. 50 CFR Figures 1-2 to Part 223 - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false 1 Figures 1-2 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES Figures 1-2 to Part 223...

  20. 50 CFR Figures 1-2 to Part 223 - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false 1 Figures 1-2 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES Figures 1-2 to Part 223...

  1. Lowering detection limits for 1,2,3-trichloropropane in water using solid phase extraction coupled to purge and trap sample introduction in an isotope dilution GC-MS method.

    PubMed

    Liao, Wenta; Ghabour, Miriam; Draper, William M; Chandrasena, Esala

    2016-09-01

    Purge and trap sample introduction (PTI) has been the premier sampling and preconcentration technique for gas chromatographic determination of volatile organic compounds (VOCs) in drinking water for almost 50 years. PTI affords sub parts-per-billion (ppb) detection limits for purgeable VOCs including fixed gases and higher boiling hydrocarbons and halocarbons. In this study the coupling of solid phase extraction (SPE) to PTI was investigated as a means to substantially increase enrichment and lower detection limits for the emerging contaminant, 1,2,3-trichloropropane (TCP). Water samples (500 mL) were dechlorinated, preserved with a biocide, and spiked with the isotope labeled internal standard, d5-TCP. The entire 500 mL sample was extracted with activated carbon or carbon molecular sieve SPE cartridges, and then eluted with dichloromethane -- excess solvent was removed in a nitrogen evaporator and diethylene glycol "keeper" remaining was dispersed in 5 mL of water for PTI GC-MS analysis. The experimental Method Detection Limit (MDL) for TCP was 0.11 ng/L (ppt) and accuracy was 95-103% in sub-ppt determinations. Groundwater samples including impaired California sources and treated water (n = 21) were analyzed with results ranging from below the method reporting limit (0.30 ng/L) to > 250 ng/L. Coupling of SPE with PTI may provide similar reductions in detection limits for other VOCs with appropriate physical-chemical properties.

  2. Fluorination of 1,2,3,4- and 1,2,3,5-tetrahalobenzenes with potassium fluoride in dimethyl sulfone

    USGS Publications Warehouse

    Finger, G.C.; Dickerson, D.R.; Shiley, R.H.

    1972-01-01

    1,2,3,4-Tetrachlorobenzene, 1,2,3,5-tetrachlorobenzene, 2,4,6-trichlorofluorobenzene, and 2,6-dichloro-1,4-difluorobenzene were fluorinated with potassium fluoride and potassium fluoride-cesium fluoride mixtures in dimethyl sulfone. By varying the concentration, temperature and reaction time, the degree of fluorination could be controlled to some extent. The optimum conditions for producing mono-, di- and tri-fluoro-substituted chlorobenzenes and trace amounts of tetrafluorobenzene from the corresponding tetrachlorobenzenes are given. 1,2,3,5-Tetrafluorobenzene was obtained in 44.8% yield from 2,6-dichloro-1,4-difluorobenzene. 1,2,3,4-Tetrafluorobenzene was obtained in only trace amounts from 1,2,3,4-tetrachlorobenzene. A total of 24 new chlorofluorobenzenes and intermediates are described. Fluorination with potassium fluoride and certain other metal fluorides was also investigated. ?? 1972.

  3. Institutional Characteristics Contributing to the Effectiveness of 4-Year Business Degrees

    ERIC Educational Resources Information Center

    Book-Ellard, Tracy Lynn

    2012-01-01

    Over $8 billion is spent yearly, on college education in one Southern U.S. state, yet the employment effectiveness of public and private 4-year undergraduate business degrees (effectiveness defined as obtaining employment or entering into a degree program requiring a 4-year business degree by the end of Year 1 and remaining employed or in a degree…

  4. X-1-2 with Pilots Robert Champine Herb Hoover

    NASA Technical Reports Server (NTRS)

    1949-01-01

    The Bell Aircraft Corporation X-1-2 and two of the NACA pilots that flew the aircraft. The one on the left is Robert Champine with the other being Herbert Hoover. The X-1-2 was also equipped with the 10-percent wing and 8 percent tail, powered with an XLR-11 rocket engine and aircraft made its first powered flight on December 9, 1946 with Chalmers 'Slick' Goodlin at the controls. As with the X-1-1 the X-1-2 continued to investigate transonic/supersonic flight regime. NACA pilot Herbert Hoover became the first civilian to fly Mach 1, March 10, 1948. X-1-2 flew until October 23, 1951, completing 74 glide and powered flights with nine different pilots, when it was retired to be rebuilt as the X-1E.

  5. Technical Fact Sheet – 1,2,3-Trichloropropane (TCP)

    EPA Pesticide Factsheets

    This fact sheet, developed by the U.S. Environmental Protection Agency (EPA) Federal Facilities Restoration and Reuse Office (FFRRO), provides a brief summary of the contaminant 1,2,3-trichloropropane (TCP), including physical and chemical properties;

  6. Technical Fact Sheet – 1,2,3-Trichloropropane (TCP)

    EPA Pesticide Factsheets

    This fact sheet, developed by the U.S. Environmental Protection Agency (EPA) Federal Facilities Restoration and Reuse Office (FFRRO), provides a brief summary of the contaminant 1,2,3-trichloropropane (TCP), including physical and chemical properties

  7. 39 CFR 1.2 - Delegation of authority.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (ARTICLE I) § 1.2 Delegation of authority. Except for powers, duties, or obligations specifically vested in the Governors by law, the Board may delegate its authority to the Postmaster General under such...

  8. INTAKE, DAMS #1, #2, AND #3, AND FOOTBRIDGE; FACING NORTHNORTHEAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTAKE, DAMS #1, #2, AND #3, AND FOOTBRIDGE; FACING NORTH-NORTHEAST - Shoshone Falls Hydroelectric Project, Intake, North Bank of Snake River, immediately West/Northwest of the Shoshone Falls Hydroelectric Project Dam No. 1, Tipperary Corner, Jerome County, ID

  9. SU(1,2) invariance in two-dimensional oscillator

    NASA Astrophysics Data System (ADS)

    Krivonos, Sergey; Nersessian, Armen

    2017-02-01

    Performing the Hamiltonian analysis we explicitly established the canonical equivalence of the deformed oscillator, constructed in arXiv:1607.03756, with the ordinary one. As an immediate consequence, we proved that the SU(1, 2) symmetry is the dynamical symmetry of the ordinary two-dimensional oscillator. The characteristic feature of this SU(1, 2) symmetry is a non-polynomial structure of its generators written in terms of the oscillator variables.

  10. Cycloadditions of Noncomplementary Substituted 1,2,3-Triazines

    PubMed Central

    2015-01-01

    The scope of the [4 + 2] cycloaddition reactions of substituted 1,2,3-triazines, bearing noncomplementary substitution with electron-withdrawing groups at C4 and/or C6, is described. The studies define key electronic and steric effects of substituents impacting the reactivity, mode (C4/N1 vs C5/N2), and regioselectivity of the cycloaddition reactions of 1,2,3-triazines with amidines, enamines, and ynamines, providing access to highly functionalized heterocycles. PMID:25222918

  11. Word Criticality Analysis MOS: 15D. Skill Levels 1 & 2.

    DTIC Science & Technology

    1981-09-01

    ICASE .2 31 2- 29,2.2-247;1 2-2 ,1;i; Sol 0 1CASTER Z; 77,1 A-~ 49*1 2- 11;1 ICASUALTY . 2-13 217,1 2.lt5;i 2-134,1 j -153,1 1-249,1 ICAICH 2-251,1 I...1 3-. 67,2 3- 69,11 3- 63,11 3- 6206 3- 611 3-:42T13- 50,11 3- 49,& 3- 44.13 3- 24.1 3- 9.3 3- 6,1 3- Sol 3- 4#1 3- 3.3 2 O3.lI 1 -209,1 2-207,1 2...6001 3- host 2-249s1 3- Sol 2-269, 0 2.25001--- 3- 5,1 2-26 ’ i -270,2 I Nf1MFNC L.AT’R rz.k 29681 3- 0,1 3- 42I , - 51,2 11- 55,1 3- ’.spz __A NUM

  12. Microbial production and applications of 1,2-propanediol.

    PubMed

    Saxena, R K; Anand, Pinki; Saran, Saurabh; Isar, Jasmine; Agarwal, Lata

    2010-03-01

    1,2-Propanediol (propylene glycol) is an existing commodity chemical and can be produced from renewable resources using microbes. By virtue of being a natural product, relevant biochemical pathways can be harnessed into fermentation processes to produce 1,2-propanediol. In the present review, the chemical process and different biological strategies for the production of 1,2-propanediol are reviewed and compared with the potentials and limitations of all processes. For the successful commercial production of this diol, it is necessary to establish the metabolic pathways and production hosts (microorganisms), which are capable of delivering final product with high yields and volumetric productivity. Three pathways which have been recognized for 1,2-propanediol production are discussed here. In the first, de-oxy sugars like fucose and rhamnose are used as the carbon sources, while in the other route, the glycolytic intermediate-dihydroxyacetonephosphate (DHAP) is used to produce 1,2-propanediol via the formation of methylglyoxal. A new pathway of 1,2-propanediol production by lactic acid degradation under anoxic conditions and the enzymes involved is also discussed. The production of this diol has gained attention because of their newer applications in industries such as polymers, food, pharmaceuticals, textiles, etc. Furthermore, improvement in fermentation technology will permit its uses in other applications. Future prospect in the light of the current research and its potential as a major bulk chemical are discussed.

  13. 7S(1/2) ? 9S(1/2) two-photon spectroscopy of trapped francium.

    PubMed

    Simsarian, J E; Shi, W; Orozco, L A; Sprouse, G D; Zhao, W Z

    1996-12-01

    We report on the spectroscopic measurement of the (210)Fr 9S(1/2) energy obtained by two-photon excitation of atoms confined and cooled in a magneto-optic trap. The resonant intermediate level 7P(3/2) is the upper state of the trapping transition. We have measured the energy difference between the 9S(1/2) state and the 7S(1/2) ground state to be 25 671.021 +/- 0.006 cm(-1).

  14. Antiferromagnetic Spin Ice Correlations at (1/2,1/2,1/2) in the Ground State of the Pyrochlore Magnet Tb2Ti2O7

    NASA Astrophysics Data System (ADS)

    Fritsch, K.; Ross, K. A.; Qiu, Y.; Copley, J. R. D.; Guidi, T.; Bewley, R. I.; Dabkowska, H. A.; Gaulin, B. D.

    2013-03-01

    The ground state of the candidate spin liquid pyrochlore magnet Tb2Ti2O7 (TTO) has been long debated. Despite theoretical expectations of magnetic order below 1K based on classical Ising-like Tb spins, muSR and neutron scattering experiments show no long range order down to 50mK. Two theoretical scenarios have been put forward to account for this: the quantum spin ice scenario and a non-magnetic singlet ground state, but no clear consensus has been reached. We present neutron scattering measurements on TTO at 70mK that reveal elastic scattering intensity at (1/2,1/2,1/2) positions in reciprocal space. The corresponding spin configuration can be modeled as a short-range antiferromagnetically ordered spin ice, in which spins obey a variant of the ice rules in each unit cell, and flip directions between adjacent cells. At low temperatures, this elastic scattering is separated from low-lying magnetic inelastic scattering by ~0.05meV. The elastic signal disappears under the application of small magnetic fields and upon elevating temperature. Pinch-point-like elastic diffuse scattering is observed, which together with the elastic spin ice correlations strongly supports the quantum spin ice picture for TTO.

  15. Will 1,2-dihydro-1,2-azaborine-based drugs resist metabolism by cytochrome P450 compound I?

    PubMed

    Silva, Pedro J

    2016-01-01

    1,2-dihydro-1,2-azaborine is a structural and electronic analogue of benzene which is able to occupy benzene-binding pockets in T4 lysozyme and has been proposed as suitable arene-mimicking group for biological and pharmaceutical applications. Its applicability in a biological context requires it to be able to resist modification by xenobiotic-degrading enzymes like the P450 cytochromes. Quantum chemical computations described in this work show that 1,2-dihydro-1,2-azaborine is much more prone to modification by these enzymes than benzene, unless steric crowding of the ring prevents it from reaching the active site, or otherwise only allows reaction at the less reactive C4-position. This novel heterocyclic compound is therefore expected to be of limited usefulness as an aryl bioisostere.

  16. Will 1,2-dihydro-1,2-azaborine-based drugs resist metabolism by cytochrome P450 compound I?

    PubMed Central

    2016-01-01

    1,2-dihydro-1,2-azaborine is a structural and electronic analogue of benzene which is able to occupy benzene-binding pockets in T4 lysozyme and has been proposed as suitable arene-mimicking group for biological and pharmaceutical applications. Its applicability in a biological context requires it to be able to resist modification by xenobiotic-degrading enzymes like the P450 cytochromes. Quantum chemical computations described in this work show that 1,2-dihydro-1,2-azaborine is much more prone to modification by these enzymes than benzene, unless steric crowding of the ring prevents it from reaching the active site, or otherwise only allows reaction at the less reactive C4-position. This novel heterocyclic compound is therefore expected to be of limited usefulness as an aryl bioisostere. PMID:27547588

  17. Method for preparation of 7-hydroxy-1,2,3,4-tetrahydroquinoline from 1,2,3,4-tetrahydroquinoline

    DOEpatents

    Field, George; Hammond, Peter R.

    1994-01-01

    Methods for the efficient preparation of 7-hydroxy-1,2,3,4-tetrahydroquinoline include a first method in which the acylation of m-aminophenol obtains a lactam which is reduced to give the desired quinoline and a second method in which tetrahydroquinoline is nitrated and hydrogenated and then hydrolyzed to obtain the desire quinoline. 7-hydroxy-1,2,3,4-tetrahydroquinoline is used in the efficient synthesis of four lasing dyes of the rhodamine class.

  18. Method for preparation of 7-hydroxy-1,2,3,4-tetrahydroquinoline from 1,2,3,4-tetrahydroquinoline

    DOEpatents

    Field, G.; Hammond, P.R.

    1994-02-01

    Methods for the efficient preparation of 7-hydroxy-1,2,3,4-tetrahydroquinoline include a first method in which the acylation of m-aminophenol obtains a lactam which is reduced to give the desired quinoline and a second method in which tetrahydroquinoline is nitrated and hydrogenated and then hydrolyzed to obtain the desire quinoline. 7-hydroxy-1,2,3,4-tetrahydroquinoline is used in the efficient synthesis of four lasing dyes of the rhodamine class.

  19. Biodegradation of 1,2,3- and 1,2,4-Trichlorobenzene in Soil and in Liquid Enrichment Culture †

    PubMed Central

    Marinucci, A. C.; Bartha, R.

    1979-01-01

    The biodegradation of radiochemically pure (99%) 1,2,3- and 1,2,4-trichlorobenzene (TCB) in soil was investigated. Experimental difficulties posed by the high volatility and slow biodegradation rate of the TCBs were partially overcome by using a specially designed incubation and trapping apparatus. Evolution of 14CO2 from active versus poisoned soil dosed with 50 μg of the individual TCBs per g gave conclusive proof that both isomers are biodegradable. At 20°C, 1,2,4-TCB was mineralized at an approximate rate of 1 nmol/day per 20 g of soil sample, and 1,2,3-TCB was mineralized at one-half to one-third that rate. Mineral fertilizers or cosubstrates failed to increase TCB mineralization rates in soil. Anaerobic conditions had a negative effect on mineralization, and increased temperatures had a positive effect. With increasing 1,2,4-TCB concentrations, 14CO2 evolution exhibited saturation kinetics with an apparent Km of 55.5 nmol per g of soil. Recovery of total radioactivity was good from soil containing high organic matter concentrations. From low-organic-matter soil, some of the radioactivity was recovered only on combustion, and overall recovery was lower. In soil-inoculated liquid culture, the cosubstrates glucose and benzene caused a slight stimulation of 1,2,4-TCB mineralization. Cochromatography of known standards with the extracts of soil pretreated with [14C]TCBs indicated that 3,4,5-trichlorophenol, 2,6-dichlorophenol and, to a lesser degree, 2,3-dichlorophenol were present in soils incubated with 1,2,3-TCB. 2,4-, 2,5-, and 3,4-dichlorophenol were present in soils incubated with 1,2,4-TCB. PMID:120698

  20. Medical migration. A study projects Americans spending up to $68 billion abroad by 2010 for treatment, but some doubt the trend's momentum.

    PubMed

    Rhea, Shawn

    2008-05-05

    As soaring costs are sending Americans abroad for healthcare, a new study projects they'll spend $68 billion annually by 2010 for overseas treatment. Besides that cost, it could pressure U.S. providers to deliver quality for less. "As you see other cultures where the outcomes look very favorable, then we'll see more people questioning why we can't provide that level of care at similar costs," says Jeffrey Moe, left.

  1. 1,2-Hydroxypyridonates as Contrast Agents for Magnetic ResonanceImaging: TREN-1,2-HOPO

    SciTech Connect

    Jocher, Christoph J.; Moore, Evan G.; Xu, Jide; Avedano, Stefano; Botta, Mauro; Aime, Silvio; Raymond, Kenneth N.

    2007-05-08

    1,2-Hydroxypyridinones (1,2-HOPO) form very stable lanthanide complexes that may be useful as contrast agents for Magnetic Resonance Imaging (MRI). X-ray diffraction of single crystals established that the solid state structures of the Eu(III) and the previously reported [Inorg. Chem. 2004, 43, 5452] Gd(III) complex are identical. The recently discovered sensitizing properties of 1,2-HOPO chelates for Eu(III) luminescence allow direct measurement of the number if water molecules in the metal complex. Fluorescence measurements of the Eu(III) complex corroborate that in solution two water molecules coordinate the lanthanide (q = 2) as proposed from the analysis of NMRD profiles. In addition, fluorescence measurements have verified the anion binding interactions of lanthanide TREN-1,2-HOPO complexes in solution, studied by relaxivity, revealing only very weak oxalate binding (K{sub A} = 82.7 {+-} 6.5 M{sup -1}). Solution thermodynamic studies of the metal complex and free ligand have been carried out using potentiometry, spectrophotometry and fluorescence spectroscopy. The metal ion selectivity of TREN-1,2-HOPO supports the feasibility of using 1,2-HOPO ligands for selective lanthanide binding [pGd = 19.3 (2); pZn = 15.2 (2), pCa = 8.8 (3)].

  2. Near infrared rubidium 62P3/2,1/2→62S1/2 laser

    NASA Astrophysics Data System (ADS)

    Moran, Paul J.; Richards, Ryan M.; Rice, Christopher A.; Perram, Glen P.

    2016-09-01

    An optically pumped near infrared rubidium (Rb) pulsed, mirrorless laser has been demonstrated in a heat pipe along both the 62P3/2-62S1/2 transition at 2.73 μm and the 62P1/2-62S1/2 transition at 2.79 μm. The bleached limit, slope efficiency, and maximum laser output energy of the near infrared Rb laser scale linearly with increasing Rb density, contrary to prior results. Previously, a maximum output energy of ~5 nJ had been observed before a rollover occurred in the scaling of output energy with rubidium concentration. In this experiment, the maximum laser output energy observed was ~100 nJ, with no indication of any scaling limitation. A maximum slope efficiency of 1.7×10-4 was observed. A small percentage of the pump photons were absorbed even at the maximum Rb density attainable in the heat pipe, indicating that laser efficiency could be scaled to near the quantum efficiency. Additionally, the hyperfine structure and absorption spectral profile of the 52S1/2-62P1/2 and 52S1/2-62P3/2 (blue) pump transitions were studied using a cw pump source.

  3. Student Financial Aid Reaches $20.5-Billion, but Fails to Keep Pace with Rising College Costs, Study Finds.

    ERIC Educational Resources Information Center

    Evangelauf, Jean

    1987-01-01

    A College Board study found that over seven years, college charges rose 56 percent to 80 percent, while institutional, state, and federal aid rose only 20 percent and dramatic shifts in the composition of federal aid occurred. (MSE)

  4. Dense Energetic Compounds of C, H, N, and O Atoms. III. 5-(4-Nitro-(1,2, 5)oxadiazolyl)-5H-(1,2,3)triazolo(4,5-c)(1,2,5)oxadiazole

    DTIC Science & Technology

    1993-07-21

    1,2,5)oxadiazolyl]-5H- [1,2,3]triazolo[4,5-cI[ 1,2,5] oxadiazole by A. Gunasekaran and J. H. Boyer Published in Heteroatom Chem., 1993, accepted...Nitro-(1,2,5)oxadiazolyl]-5H- [1,2,3] triazolo[4,5-c] [1,2,5] oxadiazole Ananthakrishnan Gunasekaran and Joseph H. Boyer* Department of Chemistry...diaminoazofurazan 7 by treat- ment with sodium azide and underwent thermolysis to 5-[4-azido-(1,2,5)oxadiazolyl]-5H- [1,2,3]triazolo[4,5-c](1,2,5] oxadiazole 5. The

  5. Medicinal Chemistry Profiling of Monocyclic 1,2-Azaborines.

    PubMed

    Zhao, Peng; Nettleton, David O; Karki, Rajeshri G; Zécri, Frédéric J; Liu, Shih-Yuan

    2017-03-07

    The first examples of biologically active monocyclic 1,2-azaborines have been synthesized and demonstrated to exhibit not only improved in vitro aqueous solubility in comparison with their corresponding carbonaceous analogues, but in the context of a CDK2 inhibitor, also improved biological activity and better in vivo oral bioavailability. This proof-of-concept study establishes the viability of monocyclic 1,2-azaborines as a novel pharmacophore with distinct pharmacological profiles that can help address challenges associated with solubility in drug development research.

  6. A New Class of Jeff = 1 / 2 Mott Insulators

    NASA Astrophysics Data System (ADS)

    Birol, Turan; Haule, Kristjan

    2015-03-01

    We predict a novel class of Jeff=1/2 Mott insulators in a family of Ir and Rh fluoride compounds with the K2GeF6 crystal structure that are previously synthesized, but not characterized extensively. First principles calculations in the level of all electron Density Functional Theory + Dynamical Mean Field Theory (DFT+DMFT) indicate that these compounds have large Mott gaps and some of them exhibit unprecedented proximity to the ideal, SU(2) symmetric Jeff=1/2 limit.

  7. Existence of independent [1, 2]-sets in caterpillars

    NASA Astrophysics Data System (ADS)

    Santoso, Eko Budi; Marcelo, Reginaldo M.

    2016-02-01

    Given a graph G, a subset S ⊆ V (G) is an independent [1, 2]-set if no two vertices in S are adjacent and for every vertex ν ∈ V (G)/S, 1 ≤ |N(ν) ∩ S| ≤ 2, that is, every vertex ν ∈ V (G)/S is adjacent to at least one but not more than two vertices in S. In this paper, we discuss the existence of independent [1, 2]-sets in a family of trees called caterpillars.

  8. Redox cycloisomerization approach to 1,2-dihydropyridines.

    PubMed

    Trost, Barry M; Biannic, Berenger

    2015-03-20

    The phosphine-catalyzed synthesis of 1,2-dihydropyridines via an alkyne isomerization/electrocyclization sequence is described. Propargylidenecarbamate substrates were prepared following a one-pot procedure between a terminal alkyne, a benzonitrile, and a chloroformate in the presence of trimethylaluminum. This methodology gives access to a diverse set of 2,6-disubstituted 1,2-dihydropyridines in high yield. The products can be easily converted into substituted piperidines or pyridines, and this methodology was applied to the synthesis of indolizidines.

  9. Antimicrobial studies of some novel quinazolinones fused with [1,2,4]-triazole, [1,2,4]-triazine and [1,2,4,5]-tetrazine rings.

    PubMed

    Pandey, Sarvesh Kumar; Singh, Abhishek; Singh, Ashutosh; Nizamuddin

    2009-03-01

    Three series of novel and new fused heterocyclic systems, viz. triazolo[4,3-a]-quinazolin-7-ones (4), [1,2,4,5]-tetrazino[4,3-a]-quinazolin-8-ones (6) and indolo[2,3-c][1,2,4]-triazino[4,3-a]-quinazolin-8-ones (8) have been synthesized from the key intermediate 3-(substituted-phenyl)-2-hydrazino-quinazolin-4-ones (3). Thus, condensation of (3) with appropriate aromatic acids in the presence of DCC in dichloromethane afforded the fused system (4), while reaction of (3) with isatin in methanol gave the corresponding Schiff base (7) which on cyclodehydration furnished another fused heterocyclic system (8). The intermediate (3) on refluxing with substituted-phenylisothiocyanate gave the substituted-thiosemicarbazide (5), which on oxidative cyclization with bromine in CCl(4) furnished the novel fused system (6). The structures of intermediate and final compounds have been determined by means of IR, (1)H NMR, (13)C NMR, UV and elemental analysis. All the synthesized compounds have been screened for their antibacterial activity against gram-negative bacteria, Escherichia coli, Pseudomonas aeruginosa and gram-positive bacteria, Streptococcus pneumoniae, Bacillus subtilis, as well as demonstrated significant antifungal activity against fungi viz. Candida albicans, Aspergillus fumigatus, Aspergillus flavus, and Aspergillus niger.

  10. Private Donations to Colleges Rise for 4th Consecutive Year

    ERIC Educational Resources Information Center

    Wolverton, Brad

    2008-01-01

    Backed by a strong economy and a growing stock market, American colleges and universities raised an estimated $29.8-billion in the 2007 fiscal year, the highest total ever recorded, according to a report released last week by the Council for Aid to Education. But the country's recent economic troubles have some fund-raising experts concerned that…

  11. Capping blowouts from Iran's eight-year war

    SciTech Connect

    Sayers, B. )

    1991-05-01

    This paper reports on capping blowouts from Iran's eight year war. Fires in three Iranian wells (two oil, one gas), started during 1987 by Iraqi sabotage, finally were extinguished during the last several months of 1990. Burning during the final months of the countries' eight-year war, plus another subsequent peaceful two years, the fires consumed millions of barrels of oil and billions of cubic feet of gas before they were capped. Ironically, bringing the wells under control took relatively little time.

  12. 43 CFR 3802.1-2 - When not required.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...-2 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINING CLAIMS UNDER THE GENERAL MINING LAWS Exploration and Mining, Wilderness Review Program § 3802.1-2 When not required. A plan of operations under...

  13. Anxiety Self Report (ASR (1,2,3,4,). X

    ERIC Educational Resources Information Center

    Parsons, Jane S.

    The Anxiety Self Report (ASR 1,2,3,4) is provided, followed by information about the report. The ASR is discussed as to its development, description, response bias, scoring procedures, reliability, stability, validity, and correlation between the ASR and the Manifest Anxiety Scale. (For related documents, see TM 002 928, 929.) (DB)

  14. CMMI (Trademark) Version 1.2, Training Changes

    DTIC Science & Technology

    2006-01-01

    exercises, and SEI instructor presentations will be intermixed throughout the week to provide a better balance. TOEFL * requirements will now be...used as part of the registration process. *Test of English as a Foreign Language © 2006 by Carnegie Mellon University CMMI v1.2: Training Changes

  15. 15. View of the Main Office (Buildings 1, 2, and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. View of the Main Office (Buildings 1, 2, and 3), U.S. Plant Introduction Station, Glenn Dale, MD, ca. 1950. Facilities and Engineering Branch. Beltsville Agricultural Research Center, Building 426. - U.S. Plant Introduction Station, 11601 Old Pond Road, Glenn Dale, Prince George's County, MD

  16. CLOSEUP AERIAL VIEW OF BLAST FURNACES 1 & 2. SHARED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CLOSE-UP AERIAL VIEW OF BLAST FURNACES 1 & 2. SHARED CAST HOUSE LIES IN BETWEEN TWO SKIP INCLINES. HIP ROOF AT RIGHT COVERS BLOWING ENGINE HOUSE. VIEW FACING NORTH. - Pittsburgh Steel Company, Monessen Works, Donner Avenue, Monessen, Westmoreland County, PA

  17. 1,2,4-Butanetriol: Analysis and Synthesis

    DTIC Science & Technology

    1982-12-08

    ANHYDRIDE ........................41 CLEAVAGE OF CYCLIC ETHERS. .. ....... ......... 43 REFERENCES .. ... .......... .......... ......... 45... NOMENCLATURE .. ... .......... .......... ........ 49 1. iii/jy NSWC TR 82-380 ILLUSTRATIONS Figure Page I HYDROGENATION OF DIETHYLMALATE IN ETHANOL OVER NIKKI...of acetic acid, acetic anhydride , and sul Uric acid yielded 1,2,4-butanetriol triacetate. Subsequent methanolysis of the acetate produced BT. Wagaman

  18. Di(hydroxyphenyl)- 1,2,4-triazole monomers

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Hergenrother, Paul M. (Inventor); Wolf, Peter (Inventor)

    1993-01-01

    The di(hydroxyphenyl)- 1,2,4-triazole monomers were first synthesized by reacting bis (4-hydroxyphenyl) hydrazide with aniline hydrochloride at 250 C in the melt and also by reacting 1,3 or 1,4-bis- (4-hydroxyphenyl)- phenylene- dihydrazide with 2 moles of aniline hydrochloride in the melt. Purification of the di(hydroxyphenyl)- 1,2,4-triazole monomers was accomplished by recrystallization. Poly (1,2,4-triazoles) (PT) were prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenyl)- 1,2,4-triazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The reactions were carried out in polar aprotic solvents such as sulfolane or diphenylsulfone using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. This synthetic route has provided high molecular weight PT of new chemical structure, is economically and synthetically more favorable than other routes, and allows for facile chemical structure variation due to the availability of a large variety of activated aromatic dihalides.

  19. The Addition of Bromine to 1,2-Diphenylethene

    ERIC Educational Resources Information Center

    Amburgey-Peters, Judith C.; Haynes, Leroy W.

    2005-01-01

    The bromination of 1,2-diphenylethene, using a variety of solvents and brominating agents, can be used in both introductory and advanced organic chemistry courses. The reactions can be used to illustrate the effects of changing solvents and reagents, as well as to reveal interesting aspects of organic reaction mechanisms.

  20. Design for a Moore No. 1 1/2 lathe

    SciTech Connect

    Rhorer, R.L.

    1981-01-01

    To increase our capability to machine small spherical parts, we are designing an ultraprecision lathe based on a Moore No. 1 1/2 measuring machine. The machine is being designed for single axis cutting, utilizing an accurate rotary table for spherical cuts. This report summarizes the design and presents an error budget analysis for the design.