Science.gov

Sample records for questionable impact origin

  1. A glass spherule of questionable impact origin from the Apollo 15 landing site: Unique target mare basalt

    USGS Publications Warehouse

    Ryder, G.; Delano, J.W.; Warren, P.H.; Kallemeyn, G.W.; Dalrymple, G.B.

    1996-01-01

    A 6 mm-diameter dark spherule, 15434,28, from the regolith on the Apennine Front at the Apollo 15 landing site has a homogeneous glass interior with a 200 ??m-thick rind of devitrified or crystallized melt. The rind contains abundant small fragments of Apollo 15 olivine-normative mare basalt and rare volcanic Apollo 15 green glass. The glass interior of the spherule has the chemical composition, including a high FeO content and high CaO/Al2O3, of a mare basalt. Whereas the major element and Sc, Ni, and Co abundances are similar to those of low-Ti mare basalts, the incompatible elements and Sr abundances are similar to those of high-Ti mare basalts. The relative abundance patterns of the incompatible trace elements are distinct from any other lunar mare basalts or KREEP; among these distinctions are a much steeper slope of the heavy rare earth elements. The 15434,28 glass has abundances of the volatile element Zn consistent with both impact glasses and crystalline mare basalts, but much lower than in glasses of mare volcanic origin. The glass contains siderophile elements such as Ir in abundances only slightly higher than accepted lunar indigenous levels, and some, such as Au, are just below such upper limits. The age of the glass, determined by the 40Ar/39Ar laser incremental heating technique, is 1647 ?? 11 Ma (2 ??); it is expressed as an age spectrum of seventeen steps over 96% of the 39Ar released, unusual for an impact glass. Trapped argon is negligible. The undamaged nature of the sphere demonstrates that it must have spent most of its life buried in regolith; 38Ar cosmic ray exposure data suggest that it was buried at less than 2m but more than a few centimeters if a single depth is appropriate. That the spherule solidified to a glass is surprising; for such a mare composition, cooling at about 50??C s-1 is required to avoid crystallization, and barely attainable in such a large spherule. The low volatile abundances, slightly high siderophile abundances, and

  2. A Glass Spherule of Questionable Impact Origin from the Apollo 15 Landing Site: Unique Target Mare Basalt

    NASA Technical Reports Server (NTRS)

    Ryder, Graham; Delano, John W.; Warren, Paul H.; Kallemeyn, Gregory W.; Dalrymple, G. Brent

    1996-01-01

    A 6 mm-diameter dark spherule, 15434,28, from the regolith on the Apennine Front at the Apollo 15 landing site has a homogeneous glass interior with a 200 microns-thick rind of devitrified or crystallized melt. The rind contains abundant small fragments of Apollo 15 olivine-normative mare basalt and rare volcanic Apollo 15 green glass. The glass interior of the spherule has the chemical composition, including a high FeO content and high CaO/Al2O3, of a mare basalt. Whereas the major element and Sc, Ni, and Co abundances are similar to those of low-Ti mare basalts, the incompatible elements and Sr abundances are similar to those of high-Ti mare basaits. The relative abundance patterns of the incompatible trace elements are distinct from any other lunar mare basalts or KREEP; among these distinctions are a much steeper slope of the heavy rare earth elements. The 15434,28 glass has abundances of the volatile element Zn consistent with both impact glasses and crystalline mare basalts, but much lower than in glasses of mare volcanic origin. The glass contains siderophile elements such as Ir in abundances only slightly higher than accepted lunar indigenous levels, and some, such as Au, are just below such upper limits. The age of the glass, determined by the Ar-40/Ar-39 laser incremental heating technique, is 1647 +/- 11 Ma (2 sigma); it is expressed as an age spectrum of seventeen steps over 96% of the Ar-38 released, unusual for an impact glass. Trapped argon is negligible. The undamaged nature of the sphere demonstrates that it must have spent most of its life buried in regolith; Ar-38 cosmic ray exposure data suggest that it was buried at less than 2m but more than a few centimeters if a single depth is appropriate. That the spherule solidified to a glass is surprising; for such a mare composition, cooling at about 50 C/s is required to avoid crystallization, and barely attainable in such a large spherule. The low volatile abundances, slightly high siderophile

  3. Open Questions on the Origin of Eukaryotes.

    PubMed

    López-García, Purificación; Moreira, David

    2015-11-01

    Despite recent progress, the origin of the eukaryotic cell remains enigmatic. It is now known that the last eukaryotic common ancestor was complex and that endosymbiosis played a crucial role in eukaryogenesis at least via the acquisition of the alphaproteobacterial ancestor of mitochondria. However, the nature of the mitochondrial host is controversial, although the recent discovery of an archaeal lineage phylogenetically close to eukaryotes reinforces models proposing archaea-derived hosts. We argue that, in addition to improved phylogenomic analyses with more comprehensive taxon sampling to pinpoint the closest prokaryotic relatives of eukaryotes, determining plausible mechanisms and selective forces at the origin of key eukaryotic features, such as the nucleus or the bacterial-like eukaryotic membrane system, is essential to constrain existing models.

  4. Impact origin of the Moon

    SciTech Connect

    Slattery, W.L.

    1998-12-31

    A few years after the Apollo flights to the Moon, it became clear that all of the existing theories on the origin of the Moon would not satisfy the growing body of constraints which appeared with the data gathered by the Apollo flights. About the same time, researchers began to realize that the inner (terrestrial) planets were not born quietly -- all had evidences of impacts on their surfaces. This fact reinforced the idea that the planets had formed by the accumulation of planetesimals. Since the Earth`s moon is unique among the terrestrial planets, a few researchers realized that perhaps the Moon originated in a singular event; an event that was quite probable, but not so probable that one would expect all the terrestrial planets to have a large moon. And thus was born the idea that a giant impact formed the Moon. Impacts would be common in the early solar system; perhaps a really large impact of two almost fully formed planets of disparate sizes would lead to material orbiting the proto-earth, a proto-moon. This idea remained to be tested. Using a relatively new, but robust, method of doing the hydrodynamics of the collision (Smoothed-Particle Hydrodynamics), the author and his colleagues (W. Benz, Univ. of Arizona, and A.G.W. Cameron, Harvard College Obs.) did a large number of collision simulations on a supercomputer. The author found two major scenarios which would result in the formation of the Moon. The first was direct formation; a moon-sized object is boosted into orbit by gravitational torques. The second is when the orbiting material forms a disk, which, with subsequent evolution can form the Moon. In either case the physical and chemical properties of the newly formed Moon would very neatly satisfy the physical and chemical constraints of the current Moon. Also, in both scenarios the surface of the Earth would be quite hot after the collision. This aspect remains to be explored.

  5. Question 1: origin of life and the living state.

    PubMed

    Kauffman, Stuart

    2007-10-01

    The aim of this article is to discuss four topics: First, the origin of molecular reproduction. Second, the origin of agency - the capacity of a system to act on its own behalf. Agency is a stunning feature of human and some wider range of life. Third, to discuss a still poorly articulated feature of life noticed by the philosopher Immanuel Kant over 200 years ago: A self propagating organization of process. We have no theory for this aspect of life, yet it is central to life. Fourth, I will discuss constraints, as in Schroedinger's aperiodic crystal (Schroedinger E, What is life? The physical aspect of the living cell, 1944), as information, part of the total non-equilibrium union of matter, energy, work, work cycles, constraints, and information that appear to comprise the living state.

  6. Question 1: Origin of Life and the Living State

    NASA Astrophysics Data System (ADS)

    Kauffman, Stuart

    2007-10-01

    The aim of this article is to discuss four topics: First, the origin of molecular reproduction. Second, the origin of agency the capacity of a system to act on its own behalf. Agency is a stunning feature of human and some wider range of life. Third, to discuss a still poorly articulated feature of life noticed by the philosopher Immanuel Kant over 200 years ago: A self propagating organization of process. We have no theory for this aspect of life, yet it is central to life. Fourth, I will discuss constraints, as in Schroedinger’s aperiodic crystal (Schroedinger E, What is life? The physical aspect of the living cell, 1944), as information, part of the total non-equilibrium union of matter, energy, work, work cycles, constraints, and information that appear to comprise the living state.

  7. Questions

    ERIC Educational Resources Information Center

    Kuntz, Haley

    2007-01-01

    A canoe trip guide for young people gets used to the never-ending flow of questions. Kids are constantly inquiring about how many kilometres have been traveled that day, how many kilometres to go that day, what is for dinner, and when the next set of moving water is coming up. With kids, the questions are endless. Questions often are used as a…

  8. Experimental U.S. Census Bureau Race and Hispanic Origin Survey Questions: Reactions from Spanish Speakers

    ERIC Educational Resources Information Center

    Terry, Rodney L.; Fond, Marissa

    2013-01-01

    People of Hispanic origin, including monolingual Spanish speakers, have experienced difficulty identifying with a race category on U.S. demographic surveys. As part of a larger research effort by the U.S. Census Bureau to improve race and Hispanic origin questions for the 2020 Census, we tested experimental versions of race and Hispanic origin…

  9. Impact origin of the Sudbury structure: Evolution of a theory

    NASA Technical Reports Server (NTRS)

    Lowman, Paul D., Jr.

    1992-01-01

    This paper reviews the origin, development, and present status of the widely accepted theory, proposed by Robert S. Dietz in 1962, that the Sudbury structure was formed by meteoritic or asteroidal impact. The impact theory for the origin of the Sudbury structure seems supported by a nearly conclusive body of evidence. However, even assuming an impact origin to be correct, at least three major questions require further study: (1) the original size and shape of the crater, before tectonic deformation and erosion; (2) the source of the melt now forming the Sudbury Igneous Complex; and (3) the degree, if any, to which the Ni-Cu-platinum group elements are meteoritic. The history of the impact theory illustrates several under-appreciated aspects of scientific research: (1) the importance of cross-fertilization between space research and terrestrial geology; (2) the role of the outsider in stimulating thinking by insiders; (3) the value of small science, at least in the initial stages of an investigation, Dietz's first field work having been at his own expense; and (4) the value of analogies (here, between the Sudbury Igneous Complex and the maria), which although incorrect in major aspects, may trigger research on totally new lines. Finally, the Sudbury story illustrates the totally unpredictable and, by implication, unplannable nature of basic research, in that insight to the origin of the world's then-greatest Ni deposit came from the study of tektites and the Moon.

  10. Impact jetting as the origin of chondrules.

    PubMed

    Johnson, Brandon C; Minton, David A; Melosh, H J; Zuber, Maria T

    2015-01-15

    Chondrules are the millimetre-scale, previously molten, spherules found in most meteorites. Before chondrules formed, large differentiating planetesimals had already accreted. Volatile-rich olivine reveals that chondrules formed in extremely solid-rich environments, more like impact plumes than the solar nebula. The unique chondrules in CB chondrites probably formed in a vapour-melt plume produced by a hypervelocity impact with an impact velocity greater than 10 kilometres per second. An acceptable formation model for the overwhelming majority of chondrules, however, has not been established. Here we report that impacts can produce enough chondrules during the first five million years of planetary accretion to explain their observed abundance. Building on a previous study of impact jetting, we simulate protoplanetary impacts, finding that material is melted and ejected at high speed when the impact velocity exceeds 2.5 kilometres per second. Using a Monte Carlo accretion code, we estimate the location, timing, sizes, and velocities of chondrule-forming impacts. Ejecta size estimates indicate that jetted melt will form millimetre-scale droplets. Our radiative transfer models show that these droplets experience the expected cooling rates of ten to a thousand kelvin per hour. An impact origin for chondrules implies that meteorites are a byproduct of planet formation rather than leftover building material.

  11. Impact Chemistry and the Origin of Life

    NASA Astrophysics Data System (ADS)

    Melosh, H. J.; Pasek, M.

    2012-12-01

    Most discussions of global environmental effects of large impacts focus on changes deleterious to extant life. However, impacts may also produce changes that enhance or even create conditions beneficial to the origin of life. Many other authors have discussed impact delivery of organic molecules, and some have shown the shock synthesis of prebiotic molecules such as amino acids during impact. Our past work on the chemistry of impacts demonstrated that strong chemical reduction occurs in impact melt ejecta (spherules and melt droplets; tektites). Here we focus on the element phosphorus (P), whose role is crucial in biology as the backbone of DNA and RNA, and in metabolic biochemical energy transfer. Pasek previously showed that reduced P readily enters into interesting biological compounds with organic molecules in aqueous solution, and that these reduced P compounds may generate structures similar to sugar phosphates, which are critical to life as we know it. In this talk we argue that impact reduction of P transforms terrestrial and meteoritic phosphates bearing an oxidation state of +5 to the lower redox states of +3 (phosphites) and 0 as an alloy with metal (phosphides). We base this argument on studies of fulgurites—glasses formed by cloud-to-ground lightning—that bear phosphides and phosphites as major carriers of P. Fulgurite chemistry frequently parallels that of impact glasses. Additionally, thermodynamic calculations show that separation of an O-rich vapor from a melt readily results in the transformation of phosphate to phosphites and metal phosphides. These results are confirmed by the presence of metal phosphides within tektites. The impact reduction of phosphates followed by global dispersal of reduced P in the form of glassy droplets likely played a major role in the origin of life on Earth and perhaps on other young planets.

  12. An open question on the origin of life: the first forms of metabolism.

    PubMed

    Luisi, Pier Luigi

    2012-11-01

    The general framework of the origin of life on Earth is outlined, emphasizing that the so-called prebiotic 'RNA world' is as yet on shaky scientific ground, and that one should any way ask the question of the structure of the first protocellular compartments capable of the initial forms of metabolism. This question is the basis of the research project on the minimal cells, containing the minimal and sufficient complexity capable of leading to life. Such research is briefly summarized, highlighting experiments with liposome-based semisynthetic cells which are capable of ribosomal protein synthesis with a very minimal number of enzymes. The most recent finding in this area of research is the unexpected observation that the formation and closure of liposomes in situ acts as an attractor for the solute molecules in solution, bringing about a very high local concentration in some of the liposomes. It is argued that this spontaneous overcrowding, which permits reactions which are not possible in the original dilute solution, might be the origin of cellular metabolism for the origin of life on Earth.

  13. Question 2: why an astrobiological study of titan will help us understand the origin of life.

    PubMed

    Raulin, Francois

    2007-10-01

    For understanding the origin(s) of life on Earth it is essential to search for and study extraterrestrial environments where some of the processes which participated in the emergence of Life on our planet are still occurring. This is one of the goals of astrobiology. In that frame, the study of extraterrestrial organic matter is essential and is certainly not of limited interest regarding prebiotic molecular evolution. Titan, the largest satellite of Saturn and the only planetary body with an atmosphere similar to that of the Earth is one of the places of prime interest for these astrobiological questions. It presents many analogies with the primitive Earth, and is a prebiotic-like laboratory at the planetary scale, where a complex organic chemistry in is currently going on.

  14. Crime laboratory proficiency testing results, 1978-1991, II: Resolving questions of common origin.

    PubMed

    Peterson, J L; Markham, P N

    1995-11-01

    A preceding article has examined the origins of crime laboratory proficiency testing and the performance of laboratories in the identification and classification of common types of physical evidence. Part II reviews laboratory proficiency in determining if two or more evidence samples shared a common source. Parts I and II together review the results of 175 separate tests issued to crime laboratories over the period 1978 to 1991. Laboratories perform best in determining the origin of finger and palm prints, metals, firearms (bullets and catridge cases), and footwear. Laboratories have moderate success in determining the source of bloodstains, questioned documents, toolmarks, and hair. A final category is of greater concern and includes those evidence categories where 10% or more of results disagree with manufacturers regarding the source of samples. This latter group includes paint, glass, fibers, and body fluid mixtures. The article concludes with a comparison of current findings with earlier LEAA study results, and a discussion of judicial and policy implications.

  15. Impact frustration of the origin of life.

    PubMed

    Maher, K A; Stevenson, D J

    1988-02-18

    One possible definition for the origin of life on Earth is the time at which the interval between devastating environmental insults by impact exceeded the timescale for establishing self-replicating proto-organisms. A quantitative relationship for the Hadean (pre-3,800 Myr ago) and Early Archean (3,800 to 3,400 Myr) impact flux can be derived from the lunar and terrestrial impact records. Also, the effects of impact-related processes on the various environments proposed for abiogenesis (the development of life through chemical evolution from inorganic materials) can be estimated. Using a range of plausible values for the timescale for abiogenesis, the interval in time when life might first have bootstrapped itself into existence can be found for each environment. We find that if the deep marine hydrothermal setting provided a suitable site, abiogenesis could have happened as early as 4,000 to 4,200 Myr ago, whereas at the surface of the Earth abiogenesis could have occurred between 3,700 and 4,000 Myr.

  16. The ultimate question of origins: God and the beginning of the Universe.

    NASA Astrophysics Data System (ADS)

    Craig, W. L.

    Both cosmology and philosophy trace their roots to the wonder felt by the ancient Greeks as they contemplated the Universe. The ultimate question remains why the Universe exists rather than nothing. This question led Leibniz to postulate the existence of a metaphysically necessary being, which he identified as God. Leibniz's critics, however, disputed this identification, claiming that the space-time universe itself may be the metaphysically necessary being. The discovery during this century that the Universe began to exist, however, calls into question the Universe's status as metaphysically necessary, since any necessary being must be eternal in its existence. Although various cosmogonic models claiming to avert the beginning of the Universe predicted by the standard model have been and continue to be offered, no model involving an eternal universe has proved as plausible as the standard model. Unless we are to assert that the Universe simply sprang into being uncaused out of nothing, we are thus led to Leibniz's conclusion. Several objections to inferring a supernatural cause of the origin of the Universe are considered and found to be unsound.

  17. The Ultimate Question of Origins: God and the Beginning of the Universe

    NASA Astrophysics Data System (ADS)

    Craig, William Lane

    1999-12-01

    Both cosmology and philosophy trace their roots to the wonder felt by the ancient Greeks as they contemplated the universe. The ultimate question remains why the universe exists rather than nothing. This question led Leibniz to postulate the existence of a metaphysically necessary being, which he identified as God. Leibniz's critics, however, disputed this identification, claiming that the space-time universe itself may be the metaphysically necessary being. The discovery during this century that the universe began to exist, however, calls into question the universe's status as metaphysically necessary, since any necessary being must be eternal in its existence. Although various cosmogonic models claiming to avert the beginning of the universe predicted by the standard model have been and continue to be offered, no model involving an eternal universe has proved as plausible as the standard model. Unless we are to assert that the universe simply sprang into being uncaused out of nothing, we are thus led to Leibniz's conclusion. Several objections to inferring a supernatural cause of the origin of the universe are considered and found to be unsound.

  18. 38 CFR 19.27 - Adequacy of Notice of Disagreement questioned within the agency of original jurisdiction.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Disagreement questioned within the agency of original jurisdiction. 19.27 Section 19.27 Pensions, Bonuses, and... Appeals Processing by Agency of Original Jurisdiction § 19.27 Adequacy of Notice of Disagreement... 19.26, there remains within the agency of original jurisdiction a conflict of opinion or a...

  19. Open Questions on the Origin of Life at Anoxic Geothermal Fields

    PubMed Central

    Mulkidjanian, Armen Y.; Bychkov, Andrew Yu.; Dibrova, Daria V.; Galperin, Michael Y.; Koonin, Eugene V.

    2014-01-01

    We have recently reconstructed the ‘hatcheries’ of the first cells by combining geochemical analysis with phylogenomic scrutiny of the inorganic ion requirements of universal components of modern cells (Mulkidjanian et al.: Origin of first cells at terrestrial, anoxic geothermal fields. Proc Natl Acad Sci USA 2012, 109:E821–830). These ubiquitous, and by inference primordial, proteins and functional systems show affinity to and functional requirement for K+, Zn2+, Mn2+, and phosphate. Thus, protocells must have evolved in habitats with a high K+/Na+ ratio and relatively high concentrations of Zn, Mn and phosphorous compounds. Geochemical reconstruction shows that the ionic composition conducive to the origin of cells could not have existed in marine settings but is compatible with emissions of vapor-dominated zones of inland geothermal systems. Under anoxic, CO2-dominated atmosphere, the ionic composition of pools of cool, condensed vapor at anoxic geothermal fields would resemble the internal milieu of modern cells. Such pools would be lined with porous silicate minerals mixed with metal sulfides and enriched in K+ ions and phosphorous compounds. Here we address some questions that have appeared in print after the publication of our anoxic geothermal field scenario. We argue that anoxic geothermal fields, which were identified as likely cradles of life by using a top-down approach and phylogenomics analysis as a tool, could provide geochemical conditions similar to those which were suggested as most conducive for the emergence of life by the chemists who pursuit the complementary bottom-up strategy. PMID:23132762

  20. Study questions environmental impact of fuel-cell vehicles

    NASA Astrophysics Data System (ADS)

    Stafford, Ned

    2015-09-01

    Fuel-cell electric vehicles are seen by many as an environmentally friendly technology that can reduce greenhousegas emissions by producing no harmful emissions. But a new study has found that overall a fuel cell electric vehicle has about the same negative environmental impact as a luxury sports car.

  1. Open questions on the origin of life at anoxic geothermal fields.

    PubMed

    Mulkidjanian, Armen Y; Bychkov, Andrew Yu; Dibrova, Daria V; Galperin, Michael Y; Koonin, Eugene V

    2012-10-01

    We have recently reconstructed the 'hatcheries' of the first cells by combining geochemical analysis with phylogenomic scrutiny of the inorganic ion requirements of universal components of modern cells (Mulkidjanian et al. Proc Natl Acad Sci U S A 109:E821-830, 2012). These ubiquitous, and by inference primordial, proteins and functional systems show affinity to and functional requirement for K⁺, Zn²⁺, Mn²⁺, and phosphate. Thus, protocells must have evolved in habitats with a high K⁺/Na⁺ ratio and relatively high concentrations of Zn, Mn and phosphorous compounds. Geochemical reconstruction shows that the ionic composition conducive to the origin of cells could not have existed in marine settings but is compatible with emissions of vapor-dominated zones of inland geothermal systems. Under an anoxic, CO₂-dominated atmosphere, the ionic composition of pools of cool, condensed vapor at anoxic geothermal fields would resemble the internal milieu of modern cells. Such pools would be lined with porous silicate minerals mixed with metal sulfides and enriched in K⁺ ions and phosphorous compounds. Here we address some questions that have appeared in print after the publication of our anoxic geothermal field scenario. We argue that anoxic geothermal fields, which were identified as likely cradles of life by using a top-down approach and phylogenomics analysis, could provide geochemical conditions similar to those which were suggested as most conducive for the emergence of life by the chemists who pursuit the complementary bottom-up strategy.

  2. Errors in medical literature: not a question of impact.

    PubMed

    Costantino, Giorgio; Casazza, Giovanni; Cernuschi, Giulia; Solbiati, Monica; Birocchi, Simone; Ceriani, Elisa; Duca, Piergiorgio; Montano, Nicola

    2013-03-01

    The editorial and peer-review processes should guarantee readers as to the reliability of published data. The first step of these processes is to check for errors. The aim of our study was to look for the presence of objective errors in consecutive articles published on three of the most authoritative clinical journals. Two reviewers evaluated the presence of any error in 200 consecutive original articles containing at least two tables, allowing a reanalysis of the data, published between October 2010 and April 2011. Error was considered any action different from what was planned. Errors were listed as: methodological, numerical and slips. They were considered as severe if numbers in the abstract were completely different from numbers reported in the full text. Among the 125 articles included in the study, 102 (82 %, 95 % CI 74-88 %) contained some kind of error, even multiple. Nine articles (7 %, 95 % CI 3-13 %) contained one slip, 92 articles (74 %, 95 % CI 65-81 %) contained at least one numerical error, and 22 articles (18 %, 95 % CI 11-25 %) contained one methodological error. Five articles (4 %, 95 % CI 1-9 %) contained one serious error. None of the errors retrieved (0 %, 95 % CI 0-2 %) would have changed the results of the studies. Most of the articles published in the most important medical journals present mistakes. Our results could be a clue to editorial and peer review systems system weaknesses. A debate within the scientific medical community about these systems, and possible alternative adjustments are needed.

  3. Growth Impacts on Public Service Expenditures: Some Questions for the Community. Coping with Growth.

    ERIC Educational Resources Information Center

    Rimbey, Neil R.

    Defining public services as the basic community/regional services which are provided to residents through tax receipts and service charges, this publication identifies variables for each service group and presents them in the form of questions that communities should find useful when analyzing impacts of growth. After listing questions dealing…

  4. Investigating the Grammatical and Pragmatic Origins of Wh-Questions in Children with Autism Spectrum Disorders

    PubMed Central

    Jyotishi, Manya; Fein, Deborah; Naigles, Letitia

    2017-01-01

    Compared to typically developing children, children with autism (ASD) show delayed production of wh-questions. It is currently controversial the degree to which such deficits derive from social-pragmatic requirements and/or because these are complex grammatical structures. The current study employed the intermodal preferential looking (IPL) paradigm, which reduces social-pragmatic demands. The IPL paradigm can help distinguish these proposals, as successful comprehension promotes the “pragmatics-origins” argument whereas comprehension difficulties would implicate a “grammatical-origins” argument. Additionally, we tested both the linguistic and social explanations by assessing the contributions of children's early grammatical knowledge (i.e., SVO word order) and their social-pragmatic scores on the Vineland to their later wh-question comprehension. Fourteen children with ASD and 17 TD children, matched on language level, were visited in their homes at 4-month intervals. Comprehension of wh-questions and SVO word order were tested via IPL: the wh-question video showed a costumed horse and bird serving as agents or patients of familiar transitive actions. During the test trials, they were displayed side by side with directing audios (e.g., “What did the horse tickle?”, “What hugged the bird?”, “Where is the horse/bird?”). Children's eye movements were coded offline; the DV was their percent looking to the named item during test. To show comprehension, children should look longer at the named item during a where-question than during a subject-wh or object-wh question. Results indicated that TD children comprehended both subject and object wh-questions at 32 months of age. Comprehension of object-wh questions emerged chronologically later in children with ASD compared to their TD peers, but at similar levels of language. Moreover, performance on word order and social-pragmatic scores independently predicted both groups' later performance on wh-question

  5. Understanding origins and impacts of drought

    NASA Astrophysics Data System (ADS)

    Loboda, Tatiana; Krankina, Olga; Kurbanov, Eldar

    2012-10-01

    Impacts of Extreme Weather on Natural, Socio-economic, and Land-Use Systems:Focus on the 2010 Summer Anomaly in the Volga Region;Yoshkar-Ola, Russia, 17-21 June 2012 In the summer of 2010 an extreme drought captured the attention of the media, the Russian government, and the international community. This drought resulted in widespread crop failure within one of the largest wheat-exporting regions of the world, leading to global grain price hikes. A joint NASA, Global Observations of Forest and Land Cover Dynamics (GOFC-GOLD), and Northern Eurasia Earth Science Partnership Initiative (NEESPI) meeting at the Volga State University of Technology, held 2 years after the 2010 drought, provided for a wide-ranging and in-depth review of recent research on the drought and its impacts on ecosystems and society and drew participants from the United States, Europe, Russia, and Kazakhstan.

  6. Examining the Impact of Question Surface Features on Students' Answers to Constructed-Response Questions on Photosynthesis

    ERIC Educational Resources Information Center

    Weston, Michele; Haudek, Kevin C.; Prevost, Luanna; Urban-Lurain, Mark; Merrill, John

    2015-01-01

    One challenge in science education assessment is that students often focus on surface features of questions rather than the underlying scientific principles. We investigated how student written responses to constructed-response questions about photosynthesis vary based on two surface features of the question: the species of plant and the order of…

  7. The origin of the Fast Radio Bursts, still an open question

    NASA Astrophysics Data System (ADS)

    Marcote, B.; Giroletti, M.; Garrett, M.; Paragi, Z.; Yuang, J.; Hada, K.; Cheung, C. C.

    2017-03-01

    Fast Radio Bursts (FRBs) are transient sources characterized by exhibiting a strong single pulse (with a duration of milliseconds or submilliseconds). They were firstly discovered by Lorimer et al. (2007), and nowadays tens of these events have been observed. Their origin remains unknown. Both, Galactic and extragalactic origins, have been proposed. The observed pulses resemble the ones from pulsars, and thus preferring a Galactic origin. However, the large dispersion measures observed in the FRBs point to an extragalactic origin. Many scenarios have been proposed up to now to explain the FRBs, most of them based on cataclysmic events. However, the discovery of the first repeating FRB (Spitler et al. 2016) indicates that could there be, at least, two different scenarios. Keane et al. (2016) reported for the first time the localization of an FRB. FRB 150418 was observed by the Parkes Telescope and a transient source associated with a galaxy was localized in the same field of view with the Australian Telescope Compact Array (ATCA). This association would confirm the extragalactic origin of the FRBs. However, this association has been widely discussed during the last months. Here we present a monitoring of the associated galaxy, WISE J071634.59190039.2, with the European VLBI Network (EVN). Our data show a compact radio emission persistent on day/week timescales one year after the observed FRB. This behavior perfectly fits to the expected emission of a regular active galactic nuclei (AGN), and thus not with the association of the FRB. The full study on this source can be found in Giroletti et al. (2016).

  8. Recent discoveries of new hantaviruses widen their range and question their origins.

    PubMed

    Henttonen, Heikki; Buchy, Philippe; Suputtamongkol, Yupin; Jittapalapong, Sathaporn; Herbreteau, Vincent; Laakkonen, Juha; Chaval, Yannick; Galan, Maxime; Dobigny, Gauthier; Charbonnel, Nathalie; Michaux, Johan; Cosson, Jean-François; Morand, Serge; Hugot, Jean-Pierre

    2008-12-01

    Hantaviruses belong to the Bunyaviridae family. While usually hosted by wild mammals, they are potentially pathogenic for humans, and several serologically distinct groups associated with different syndromes have been identified. Yet, investigations have mostly been conducted where human infections by hantaviruses constitute a real and well-identified public health problem, i.e., the holarctic and neotropical areas. Some hantaviruses have also been described from a Suncus murinus in India and a Bandicota indica in Thailand. In addition, recent investigations in Cambodia revealed new Hantavirus types. More recently, two new Hantavirus species were described: Sangassou from a Hylomyscus simus, and Tanganya from a Crocidura theresae, both from Africa (Guinea), thus strongly questioning the current views about geographic range, evolution, and epidemiology of hantaviruses. In such a framework, we have conducted a survey of Hantavirus diversity in Southeast Asia which allows us to isolate the Thailand virus and address questions about the taxonomy of their rodent hosts. Here we present a molecular analysis of representatives of all currently known Hantavirus species, thus allowing the comparison between the newly described ones with a large range sample of rodent hantaviruses. Our results clearly point to the presence of a particular lineage of hantaviruses in Southeast Asia. It also strongly suggests that new viruses, additional mammalian hosts and different related syndromes in humans are likely to be discovered in the near future, particularly in Southeast Asia and in Africa, where Muridae rodents are highly diversified. Furthermore, additional work is also urgently needed to investigate the hantaviruses associated with Crociduridae and Soricidae.

  9. Open questions in origin of life: experimental studies on the origin of nucleic acids and proteins with specific and functional sequences by a chemical synthetic biology approach.

    PubMed

    Adamala, Katarzyna; Anella, Fabrizio; Wieczorek, Rafal; Stano, Pasquale; Chiarabelli, Cristiano; Luisi, Pier Luigi

    2014-01-01

    In this mini-review we present some experimental approaches to the important issue in the origin of life, namely the origin of nucleic acids and proteins with specific and functional sequences. The formation of macromolecules on prebiotic Earth faces practical and conceptual difficulties. From the chemical viewpoint, macromolecules are formed by chemical pathways leading to the condensation of building blocks (amino acids, or nucleotides) in long-chain copolymers (proteins and nucleic acids, respectively). The second difficulty deals with a conceptual problem, namely with the emergence of specific sequences among a vast array of possible ones, the huge "sequence space", leading to the question "why these macromolecules, and not the others?" We have recently addressed these questions by using a chemical synthetic biology approach. In particular, we have tested the catalytic activity of small peptides, like Ser-His, with respect to peptide- and nucleotides-condensation, as a realistic model of primitive organocatalysis. We have also set up a strategy for exploring the sequence space of random proteins and RNAs (the so-called "never born biopolymer" project) with respect to the production of folded structures. Being still far from solved, the main aspects of these "open questions" are discussed here, by commenting on recent results obtained in our groups and by providing a unifying view on the problem and possible solutions. In particular, we propose a general scenario for macromolecule formation via fragment-condensation, as a scheme for the emergence of specific sequences based on molecular growth and selection.

  10. Question 1: Peptide nucleic acids and the origin and homochirality of life.

    PubMed

    Nielsen, Peter E

    2007-10-01

    The possibilities of pseudo peptide DNA mimics like PNA (peptide nucleic acid) having a role for the prebiotic origin of life prior to an RNA world is discussed. In particular a scenario is proposed in which protocells with an achiral genetic material through several generations stepwise is converted into a chiral genetic material, e.g., by incorporation of RNA units. Provided that a sufficiently large sequence space is occupied, a selection process based on catalytic function in which a single cell (first common ancestor) has a definite evolutionary advantage, selection of this cell would by contingency also lock it into homochirality.

  11. Examining the Impact of Question Surface Features on Students’ Answers to Constructed-Response Questions on Photosynthesis

    PubMed Central

    Weston, Michele; Haudek, Kevin C.; Prevost, Luanna; Urban-Lurain, Mark; Merrill, John

    2015-01-01

    One challenge in science education assessment is that students often focus on surface features of questions rather than the underlying scientific principles. We investigated how student written responses to constructed-response questions about photosynthesis vary based on two surface features of the question: the species of plant and the order of two question prompts. We asked four versions of the question with different combinations of the two plant species and order of prompts in an introductory cell biology course. We found that there was not a significant difference in the content of student responses to versions of the question stem with different species or order of prompts, using both computerized lexical analysis and expert scoring. We conducted 20 face-to-face interviews with students to further probe the effects of question wording on student responses. During the interviews, we found that students thought that the plant species was neither relevant nor confusing when answering the question. Students identified the prompts as both relevant and confusing. However, this confusion was not specific to a single version. PMID:25999312

  12. "Finding Useful Questions: On Bayesian Diagnosticity, Probability, Impact, and Information Gain": Correction to Nelson (2005)

    ERIC Educational Resources Information Center

    Nelson, Jonathan D.

    2007-01-01

    Reports an error in "Finding Useful Questions: On Bayesian Diagnosticity, Probability, Impact, and Information Gain" by Jonathan D. Nelson (Psychological Review, 2005[Oct], Vol 112[4], 979-999). In Table 13, the data should indicate that 7% of females had short hair and 93% of females had long hair. The calculations and discussion in the article…

  13. Finding Useful Questions: On Bayesian Diagnosticity, Probability, Impact, and Information Gain

    ERIC Educational Resources Information Center

    Nelson, Jonathan D.

    2005-01-01

    Several norms for how people should assess a question's usefulness have been proposed, notably Bayesian diagnosticity, information gain (mutual information), Kullback-Liebler distance, probability gain (error minimization), and impact (absolute change). Several probabilistic models of previous experiments on categorization, covariation assessment,…

  14. The Impact of Initial Teacher Education on Understandings of Physical Education: Asking the Right Question

    ERIC Educational Resources Information Center

    Chroinin, Deirdre Ni; Coulter, Maura

    2012-01-01

    Evaluation of professional socialisation can provide insight on the impact of Physical Education Teacher Education. A large-scale (n=326) single question "What is PE?" qualitative methodology was used to access pre-service primary teachers' understandings of the nature and purpose of physical education . Data analysis involved word…

  15. Compound-specific isotope analysis: Questioning the origins of a trichloroethene plume

    USGS Publications Warehouse

    Eberts, S.M.; Braun, C.; Jones, S.

    2008-01-01

    Stable carbon isotope ratios of trichloroethene (TCE), cis-1,2- dichloroethene, and trans-1,2-dichloroethene were determined by use of gas chromatography-combustion-isotope ratio mass spectroscopy to determine whether compound-specific stable carbon isotopes could be used to help understand the origin and history of a TCE groundwater plume in Fort Worth, TX. Calculated ??13C values for total chlorinated ethenes in groundwater samples, which can approximate the ??13C of a spilled solvent if all degradation products are accounted for, were useful for determining whether separate lobes of the plume resulted from different sources. Most notably, values for one lobe, where tetrachloroethene (PCE) has been detected periodically, were outside the range for manufactured TCE but within the range for manufactured PCE, whereas values for a separate lobe, which is downgradient of reported TCE spills, were within the range for manufactured TCE. Copyright ?? Taylor & Francis Group, LLC.

  16. Mars 2001 Mission: Addressing Scientific Questions Regarding the Characteristics and Origin of Local Bedrock and Soil

    NASA Technical Reports Server (NTRS)

    Saunders, R. S.; Arvidson, R. E.; Weitz, C. M.; Marshall, J.; Squyres, S. W.; Christensen, P. R.; Meloy, T.; Smith, P.

    1999-01-01

    The Mars Surveyor Program 2001 Mission will carry instruments on the orbiter, lander and rover that will support synergistic observations and experiments to address important scientific questions regarding the local bedrock and soils. The martian surface is covered in varying degrees by fine materials less than a few mms in size. Viking and Pathfinder images of the surface indicate that soils at those sites are composed of fine particles. Wheel tracks from the Sojourner rover suggest that soil deposits are composed of particles <40 mm. Viking images show that dunes are common in many areas on Mars and new MOC images indicate that dunes occur nearly everywhere. Dunes on Mars are thought to be composed of 250-500 microns particles based upon Viking IRTM data and Mars wind tunnel experiments. If martian dunes are composed of sand particles > 100 microns and soils are dominated by <10 micron particles, then where are the intermediate grain sizes? Have they been wom away through prolonged transport over the eons? Were they never generated to begin with? Or are they simply less easy to identify because do they not form distinctive geomorphic features such as dunes or uniform mantles that tend to assume superposition in the soil structure?

  17. Origin of insoluble organic matter in type 1 and 2 chondrites: New clues, new questions

    NASA Astrophysics Data System (ADS)

    Quirico, Eric; Orthous-Daunay, François-Régis; Beck, Pierre; Bonal, Lydie; Brunetto, Rosario; Dartois, Emmanuel; Pino, Thomas; Montagnac, Gilles; Rouzaud, Jean-Noël; Engrand, Cécile; Duprat, Jean

    2014-07-01

    Insoluble organic matter (IOM) extracted from primitive chondrites is a polyaromatic solid with a structure and composition resembling that of terrestrial kerogens. A survey of its composition and structure has been carried out on a series of 27 CR, CM, CI and ungrouped C2 carbonaceous chondrites (Tagish Lake, Bells, Essebi, Acfer 094) using infrared and multi-wavelength Raman micro-spectroscopy (244, 514 and 785 nm laser excitations). The results show that chondritic IOM from PCA 91008 (CM2), WIS 91600 (CM2), QUE 93005 (CM2), Tagish Lake (C2 ungrouped) and possibly Cold Bokkeveld (CM2) has been subjected to the past action of short duration thermal metamorphism, presumably triggered by impacts. The IOM in most of the CM chondrites that experienced moderate to heavy aqueous alteration may have been slightly modified by collision-induced heating. However, even IOM from chondrites that escaped significant thermal metamorphism displays Raman characteristics consistent with a formation by thermal processing, either in the protosolar disk or in the parent body. An alternative energetic process to thermal heating is ion irradiation. After thoroughly analyzing both these scenarii, no conclusion can be drawn as to which is the most plausible mechanism nor whether the heating process took place prior or after accretion. The results show for the first time that the width of the G band in spectra collected with a 514 nm excitation correlates with the O/C atomic ratio, suggesting a major role of oxygen in the cross-linking of polyaromatic units.

  18. Open questions in origin of life: experimental studies on the origin of nucleic acids and proteins with specific and functional sequences by a chemical synthetic biology approach

    PubMed Central

    Adamala, Katarzyna; Anella, Fabrizio; Wieczorek, Rafal; Stano, Pasquale; Chiarabelli, Cristiano; Luisi, Pier Luigi

    2014-01-01

    In this mini-review we present some experimental approaches to the important issue in the origin of life, namely the origin of nucleic acids and proteins with specific and functional sequences. The formation of macromolecules on prebiotic Earth faces practical and conceptual difficulties. From the chemical viewpoint, macromolecules are formed by chemical pathways leading to the condensation of building blocks (amino acids, or nucleotides) in long-chain copolymers (proteins and nucleic acids, respectively). The second difficulty deals with a conceptual problem, namely with the emergence of specific sequences among a vast array of possible ones, the huge “sequence space”, leading to the question “why these macromolecules, and not the others?” We have recently addressed these questions by using a chemical synthetic biology approach. In particular, we have tested the catalytic activity of small peptides, like Ser-His, with respect to peptide- and nucleotides-condensation, as a realistic model of primitive organocatalysis. We have also set up a strategy for exploring the sequence space of random proteins and RNAs (the so-called “never born biopolymer” project) with respect to the production of folded structures. Being still far from solved, the main aspects of these “open questions” are discussed here, by commenting on recent results obtained in our groups and by providing a unifying view on the problem and possible solutions. In particular, we propose a general scenario for macromolecule formation via fragment-condensation, as a scheme for the emergence of specific sequences based on molecular growth and selection. PMID:24757502

  19. Genetic data suggest a natural prehuman origin of open habitats in northern Madagascar and question the deforestation narrative in this region.

    PubMed

    Quéméré, Erwan; Amelot, Xavier; Pierson, Julie; Crouau-Roy, Brigitte; Chikhi, Lounès

    2012-08-07

    The impact of climate change and anthropogenic deforestation on biodiversity is of growing concern worldwide. Disentangling how past anthropogenic and natural factors contributed to current biome distribution is thus a crucial issue to understand their complex interactions on wider time scales and to improve predictions and conservation strategies. This is particularly important in biodiversity hotspots, such as Madagascar, dominated by large open habitats whose origins are increasingly debated. Although a dominant narrative argues that Madagascar was originally entirely covered by woodlands, which were destroyed by humans, a number of recent studies have suggested that past climatic fluctuations played a major role in shaping current biome distributions well before humans arrived. Here, we address the question of the origin of open habitats in the Daraina region in northern Madagascar, using a multiproxy approach combining population genetics modeling and remote-sensing analyses. We show that (i) contrary to most regions of Madagascar, the forest cover in Daraina remained remarkably stable over the past 60 y, and (ii) the golden-crowned sifaka (Propithecus tattersalli), a forest-dwelling lemur, underwent a strong population contraction before the arrival of the first humans, hence excluding an anthropogenic cause. Prehuman Holocene droughts may have led to a significant increase of grasslands and a reduction in the species' habitat. This contradicts the prevailing narrative that land cover changes are necessarily anthropogenic in Madagascar but does not preclude the later role played by humans in other regions in which recent lemur bottlenecks have been observed.

  20. Genetic data suggest a natural prehuman origin of open habitats in northern Madagascar and question the deforestation narrative in this region

    PubMed Central

    Quéméré, Erwan; Amelot, Xavier; Pierson, Julie; Crouau-Roy, Brigitte; Chikhi, Lounès

    2012-01-01

    The impact of climate change and anthropogenic deforestation on biodiversity is of growing concern worldwide. Disentangling how past anthropogenic and natural factors contributed to current biome distribution is thus a crucial issue to understand their complex interactions on wider time scales and to improve predictions and conservation strategies. This is particularly important in biodiversity hotspots, such as Madagascar, dominated by large open habitats whose origins are increasingly debated. Although a dominant narrative argues that Madagascar was originally entirely covered by woodlands, which were destroyed by humans, a number of recent studies have suggested that past climatic fluctuations played a major role in shaping current biome distributions well before humans arrived. Here, we address the question of the origin of open habitats in the Daraina region in northern Madagascar, using a multiproxy approach combining population genetics modeling and remote-sensing analyses. We show that (i) contrary to most regions of Madagascar, the forest cover in Daraina remained remarkably stable over the past 60 y, and (ii) the golden-crowned sifaka (Propithecus tattersalli), a forest-dwelling lemur, underwent a strong population contraction before the arrival of the first humans, hence excluding an anthropogenic cause. Prehuman Holocene droughts may have led to a significant increase of grasslands and a reduction in the species’ habitat. This contradicts the prevailing narrative that land cover changes are necessarily anthropogenic in Madagascar but does not preclude the later role played by humans in other regions in which recent lemur bottlenecks have been observed. PMID:22826244

  1. Inheritance of silicate differentiation during lunar origin by giant impact

    NASA Technical Reports Server (NTRS)

    Warren, Paul H.

    1992-01-01

    It is pointed out that the implication of the popular giant impact model of lunar origin (e.g., Hartmann and Davis, 1975; Cameron and Ward, 1976; Stevenson, 1987) is that any depth-related silicate differentiation within the impactor (and/or the earth) at the time of the impact must be partly inherited by the preferentially peripheral matter that forms the moon. This paper presents calculations of the magnitude of the net differentiation of the protolunar matter for a variety of elements and scenarios, with different assumptions regarding the geometries of the 'sampled' peripheral zones, the relative proportions of the earth-derived to impactor-derived matter in the final moon, and the degree to which the impactor mantle had crystallized prior to the giant impact. It is shown that these differention effects constrain the overall plausibility of the giant impact hypothesis.

  2. Origin of the Vredefort structure, South Africa: Impact model

    NASA Technical Reports Server (NTRS)

    Therriault, A. M.; Reid, A. M.; Reimold, W. U.

    1993-01-01

    A model is presented for the evolution of the Vredefort structure, based on reasoned constraints on the original size of the Vredefort structure from observational data and comparison with other terrestrial impact craters. The models for complex craters (ring and multi-ring basins) of Croft, Grieve, and co-workers, and Schultz and co-workers, were used to reconstruct the Vredefort impact event, using a final crater diameter of 300 km, as estimated by Therriault. The sequence of events (stages 2-5) is illustrated diagramatically. The stages are: initial penetration, excavation and compression, dynamic rebound and uplift, maximum radial growth and collapse, and final crater form.

  3. The Origin and Impact History of Lunar Meteorite Yamato 86032

    NASA Technical Reports Server (NTRS)

    Yamaguchi, A.; Takeda, H.; Nyquist, L. E.; Bogard, D. D.; Ebihara, M.; Karouji, Y.

    2004-01-01

    Yamato (Y) 86032 is a feldspathic lunar highland breccia having some characteristics of regolith breccia. The absence of KREEP components in the matrix in Y86032 indicates that these meteorites came from a long distance from Mare Imbrium, perhaps from the far-side of the moon. One ferroan anorthosite (FAN) clast in Y86032 has a very old Ar-Ar age of approximately 4.35-4.4 Ga. The negative Nd of this clast may suggest a direct link with the primordial magma ocean. The facts indicate that Y86032 contains components derived from a protolith of the original lunar crust. Detailed petrologic characterization of each component in this breccia is essential to understand the early impact history and origin of the lunar highland crust. We made a large slab (5.2 x 3.6 cm x 3-5 mm) of Y86032 to better understand the relationship of various lithologies and their petrologic origin.

  4. The origin and emergence of life under impact bombardment.

    PubMed

    Cockell, Charles S

    2006-10-29

    Craters formed by asteroids and comets offer a number of possibilities as sites for prebiotic chemistry, and they invite a literal application of Darwin's 'warm little pond'. Some of these attributes, such as prolonged circulation of heated water, are found in deep-ocean hydrothermal vent systems, previously proposed as sites for prebiotic chemistry. However, impact craters host important characteristics in a single location, which include the formation of diverse metal sulphides, clays and zeolites as secondary hydrothermal minerals (which can act as templates or catalysts for prebiotic syntheses), fracturing of rock during impact (creating a large surface area for reactions), the delivery of iron in the case of the impact of iron-containing meteorites (which might itself act as a substrate for prebiotic reactions), diverse impact energies resulting in different rates of hydrothermal cooling and thus organic syntheses, and the indiscriminate nature of impacts into every available lithology-generating large numbers of 'experiments' in the origin of life. Following the evolution of life, craters provide cryptoendolithic and chasmoendolithic habitats, particularly in non-sedimentary lithologies, where limited pore space would otherwise restrict colonization. In impact melt sheets, shattered, mixed rocks ultimately provided diverse geochemical gradients, which in present-day craters support the growth of microbial communities.

  5. A multiple-impact origin for the Moon

    NASA Astrophysics Data System (ADS)

    Rufu, Raluca; Aharonson, Oded; Perets, Hagai B.

    2017-01-01

    The hypothesis of lunar origin by a single giant impact can explain some aspects of the Earth-Moon system. However, it is difficult to reconcile giant-impact models with the compositional similarity of the Earth and Moon without violating angular momentum constraints. Furthermore, successful giant-impact scenarios require very specific conditions such that they have a low probability of occurring. Here we present numerical simulations suggesting that the Moon could instead be the product of a succession of a variety of smaller collisions. In this scenario, each collision forms a debris disk around the proto-Earth that then accretes to form a moonlet. The moonlets tidally advance outward, and may coalesce to form the Moon. We find that sub-lunar moonlets are a common result of impacts expected onto the proto-Earth in the early Solar System and find that the planetary rotation is limited by impact angular momentum drain. We conclude that, assuming efficient merger of moonlets, a multiple-impact scenario can account for the formation of the Earth-Moon system with its present properties.

  6. The origin and emergence of life under impact bombardment

    PubMed Central

    Cockell, Charles S

    2006-01-01

    Craters formed by asteroids and comets offer a number of possibilities as sites for prebiotic chemistry, and they invite a literal application of Darwin's ‘warm little pond’. Some of these attributes, such as prolonged circulation of heated water, are found in deep-ocean hydrothermal vent systems, previously proposed as sites for prebiotic chemistry. However, impact craters host important characteristics in a single location, which include the formation of diverse metal sulphides, clays and zeolites as secondary hydrothermal minerals (which can act as templates or catalysts for prebiotic syntheses), fracturing of rock during impact (creating a large surface area for reactions), the delivery of iron in the case of the impact of iron-containing meteorites (which might itself act as a substrate for prebiotic reactions), diverse impact energies resulting in different rates of hydrothermal cooling and thus organic syntheses, and the indiscriminate nature of impacts into every available lithology—generating large numbers of ‘experiments’ in the origin of life. Following the evolution of life, craters provide cryptoendolithic and chasmoendolithic habitats, particularly in non-sedimentary lithologies, where limited pore space would otherwise restrict colonization. In impact melt sheets, shattered, mixed rocks ultimately provided diverse geochemical gradients, which in present-day craters support the growth of microbial communities. PMID:17008223

  7. ON A GIANT IMPACT ORIGIN OF CHARON, NIX, AND HYDRA

    SciTech Connect

    Canup, Robin M.

    2011-02-15

    It is generally believed that Charon was formed as a result of a large, grazing collision with Pluto that supplied the Pluto-Charon system with its high angular momentum. It has also been proposed that Pluto's small outer moons, Nix and Hydra, formed from debris from the Charon-forming impact, although the viability of this scenario remains unclear. Here I use smooth particle hydrodynamics impact simulations to show that it is possible to simultaneously form an intact Charon and an accompanying debris disk from a single impact. The successful cases involve colliding objects that are partially differentiated prior to impact, having thin outer ice mantles overlying a uniform composition rock-ice core. The composition of the resulting debris disks varies from a mixture of rock and ice (similar to the bulk composition of Pluto and Charon) to a pure ice disk. If Nix and Hydra were formed from such an impact-generated disk, their densities should be less than or similar to that of Charon and Pluto, and the small moons could be composed entirely of ice. If they were instead formed from captured material, a mixed rock-ice composition and densities similar to that of Charon and Pluto would be expected. Improved constraints on the properties of Nix and Hydra through occultations and/or the New Horizons encounter may thus help to distinguish between these two modes of origin, particularly if the small moons are found to have ice-like densities.

  8. Towards answering the "so what" question in marine renewables environmental impact assessment.

    NASA Astrophysics Data System (ADS)

    Degraer, Steven; Birchenough, Silvana N. R.; Braeckman, Ulrike; Coolen, Joop W. P.; Dannheim, Jennifer; De Mesel, Ilse; Grégoire, Marilaure; Kerckhof, Francis; Lacroix, Geneviève; Lindeboom, Han; Moens, Tom; Soetaert, Karline; Vanaverbeke, Jan; Van Hoey, Gert

    2016-04-01

    Marine renewable energy (MRE) projects are increasingly occupying the European North-Atlantic coasts and this is clearly observed in the North Sea. Given the expected impacts on the marine environment, each individual project is accompanied by a legally mandatory, environmental monitoring programme. These programmes are focused on the resultant effects on ecosystem component structure (e.g. species composition, numbers and densities) of single industrial projects. To date, there is a tendency to further narrow down to only a selection of ecosystem components (e.g. marine mammals and birds). While a wide knowledge-based understanding of structural impacts on (a selection of) ecosystem components exists, this evidence is largely lacking when undertaking impact assessments at the ecosystem functioning level (e.g. trophic interactions, dispersal and nutrient cycling). This critical knowledge gap compromises a scientifically-underpinned answer to the "so what" question of environmental impacts, i.e. whether the observed impacts are considered to be good or bad, or acceptable or unacceptable. The importance of ecosystem functioning is further acknowledged in the descriptors 4 and 6 of the Marine Strategy Framework Directive (EU MSFD) and is at the heart of a sustainable use and management of our marine resources. There hence is a fundamental need to focus on ecosystem functioning at the spatial scales at which marine ecosystems function when assessing MRE impacts. Here, we make a plea for an increased investment in a large (spatial) scale impact assessment of MRE projects focused on ecosystem functioning. This presentation will cover a selection of examples from North Sea MRE monitoring programmes, where the current knowledge has limited conclusions on the "so what" question. We will demonstrate how an ecosystem functioning-focused approach at an appropriate spatial scale could advance our current understanding, whilst assessing these issues. These examples will cover

  9. Origin of small pits in martian impact craters

    NASA Astrophysics Data System (ADS)

    Boyce, Joseph M.; Wilson, Lionel; Mouginis-Mark, Peter J.; Hamilton, Christopher W.; Tornabene, Livio L.

    2012-09-01

    We propose a numerical model for the formation of the closely-spaced pits found in the thin, ejecta-related deposits superposed on the floors, interior terrace blocks, and near-rim ejecta blankets of well-preserved martian impact craters. Our model predicts the explosive degassing of water from this pitted material, which is assumed to originally be water-bearing, impact melt-rich breccia at the time of deposition. This process is analogous to what occurred in the fall-out suevite deposits at the Ries impact structure in Germany. At Ries, impact heating of water-bearing target material resulted in the rapid degassing of its water and other volatiles. The martian environment plays an important role in enhancing the effects of this degassing by increasing the flow-speed of the escaping gas. The high flow-rate of gas through particulate materials, such as suevite, tends to quickly form segregation channels or vent pipes, similar to those found in the Ries deposits. These pipes act as conduits for the efficient high-speed escape of the gas and small clasts that it entrains. Escaping gas and entrained clasts abraded and eroded the conduit walls, flaring them to form pits above a network of pipes.

  10. Cloud Creek structure, central Wyoming, USA: Impact origin confirmed

    NASA Astrophysics Data System (ADS)

    Stone, D. S.; Therriault, A. M.

    2003-03-01

    The circular Cloud Creek structure in central Wyoming, USA is buried beneath ~1200 m of Mesozoic sedimentary rocks and has a current diameter of ~7 km. The morphology/morphometry of the structure, as defined by borehole, seismic, and gravity data, is similar to that of other buried terrestrial complex impact structures in sedimentary target rocks, e.g., Red Wing Creek in North Dakota, USA. The structure has a fault-bordered central peak with minimum diameter of ~1.4 km, composed predominantly of Paleozoic carbonates thickened by thrust faulting and brecciation, and is elevated some 520 m above equivalent strata beyond the outer rim of the structure. There is a ~1.6 km wide annular trough sloping away from the central peak (maximum structural relief, 300 m) and terminated by a detached, fault-bounded, rim anticline. The youngest rocks within the structure are Late Triassic (Norian?) clastics and these are overlain unconformably by post-impact Middle Jurassic (Bathonian?) sandstones and shales. Thus, the formation of the Cloud Creek structure is dated chronostratigraphicly as ~190 ± 20 Ma. Reported here for the first time are measurements of planar deformation features (PDFs) in shocked quartz grains in thin sections made from drill cuttings recovered in a borehole drilled at the southern perimeter of the central peak. Other, less definitive microstructures consistent with impact occur in samples collected from boreholes drilled into the central peak and rim anticline. The shock- metamorphic evidence confirms an impact origin for the Cloud Creek structure.

  11. The Impact of Asking Intention or Self-Prediction Questions on Subsequent Behavior

    PubMed Central

    Wood, Chantelle; Conner, Mark; Miles, Eleanor; Sandberg, Tracy; Taylor, Natalie; Godin, Gaston; Sheeran, Paschal

    2015-01-01

    The current meta-analysis estimated the magnitude of the impact of asking intention and self-prediction questions on rates of subsequent behavior, and examined mediators and moderators of this question–behavior effect (QBE). Random-effects meta-analysis on 116 published tests of the effect indicated that intention/prediction questions have a small positive effect on behavior (d+ = 0.24). Little support was observed for attitude accessibility, cognitive dissonance, behavioral simulation, or processing fluency explanations of the QBE. Multivariate analyses indicated significant effects of social desirability of behavior/behavior domain (larger effects for more desirable and less risky behaviors), difficulty of behavior (larger effects for easy-to-perform behaviors), and sample type (larger effects among student samples). Although this review controls for co-occurrence of moderators in multivariate analyses, future primary research should systematically vary moderators in fully factorial designs. Further primary research is also needed to unravel the mechanisms underlying different variants of the QBE. PMID:26162771

  12. Testing and Resilience of the Impact Origin of the Moon

    NASA Technical Reports Server (NTRS)

    Righter, K.; Canup, R. M.

    2016-01-01

    The leading hypothesis for the origin of the Moon is the giant impact model, which grew out of the post-Apollo science community. The hypothesis was able to explain the high E-M system angular momentum, the small lunar core, and consistent with the idea that the early Moon melted substantially. The standard hypothesis requires that the Moon be made entirely from the impactor, strangely at odds with the nearly identical oxygen isotopic composition of the Earth and Moon, compositions that might be expected to be different if Moon came from a distinct impactor. Subsequent geochemical research has highlighted the similarity of both geochemical and isotopic composition of the Earth and Moon, and measured small but significant amounts of volatiles in lunar glassy materials, both of which are seemingly at odds with the standard giant impact model. Here we focus on key geochemical measurements and spacecraft observations that have prompted a healthy re-evaluation of the giant impact model, provide an overview of physical models that are either newly proposed or slightly revised from previous ideas, to explain the new datasets.

  13. Impact origin of the Newporte structure, Williston basin, North Dakota

    SciTech Connect

    Forsman, N.F.; Gerlach, T.R.; Anderson, N.L.

    1996-05-01

    The Newporte field is located just south of the United States-Canada border in Renville County, North Dakota, in the north-central portion of the Williston basin. Integration of seismic, well-log, and core data supports the interpretation of an impact origin for the Newporte structure. The structure involves both Precambrian basement and lower Paleozoic sedimentary units. Oil and gas production began in 1977 from brecciated basement rocks along the rim of the 3.2-km-diameter circular structure. Both well logs and seismic data were used to determine thickness changes of sedimentary units overlying the structure. Resulting isopach maps reveal a circular, bowl-shaped feature with a recognizable rim. Microscopic shock metamorphic features in quartz and feldspar are visible in basement clasts that form a mixed breccia with Cambrian Deadwood sandstone within the western rim of the structure. A Late Cambrian-Early Ordovician age is suggested for the structure because of the presence of flatlying Deadwood sandstone overlying mixed basement/sandstone breccia along portions of the rim. Identification of the Newporte structure as an impact crater adds to the growing base of evidence revealing the relevance of impact craters to petroleum exploration.

  14. The Impact of Multifaceted Questions on Eyewitness Accuracy Following Forced Fabrication Interviews.

    PubMed

    Chrobak, Quin M; Rindal, Eric J; Zaragoza, Maria S

    2015-01-01

    Lawyers will frequently use complex-question forms, such as multifaceted questions (single questions that contain both a true and a false proposition), when cross-examining witnesses, and prior research has shown that use of such questions reduces testimonial accuracy. The present study extends this research by using a forced fabrication paradigm (Chrobak & Zaragoza, 2008) to assess how multifaceted questions might affect eyewitness suggestibility after exposure to misleading post-event information. Consistent with prior studies, the use of multifaceted questions led to lower accuracy than simple questions. The novel finding was that multifaceted questions caused larger impairments in performance among fabrication participants (who had earlier been suggestively interviewed), than in control participants (who had not). We also provide preliminary evidence that the impairment caused by multifaceted questions is due to both (a) having to consider two propositions simultaneously, and (b) the shift in question focus from the fabricated event to a true event.

  15. Traits, not origin, explain impacts of plants on larval amphibians.

    PubMed

    Cohen, Jillian S; Maerz, John C; Blossey, Bernd

    2012-01-01

    Managing habitats for the benefit of native fauna is a priority for many government and private agencies. Often, these agencies view nonnative plants as a threat to wildlife habitat, and they seek to control or eradicate nonnative plant populations. However, little is known about how nonnative plant invasions impact native fauna, and it is unclear whether managing these plants actually improves habitat quality for resident animals. Here, we compared the impacts of native and nonnative wetland plants on three species of native larval amphibians; we also examined whether plant traits explain the observed impacts. Specifically, we measured plant litter quality (carbon : nitrogen : phosphorus ratios, and percentages of lignin and soluble phenolics) and biomass, along with a suite of environmental conditions known to affect larval amphibians (hydroperiod, temperature, dissolved oxygen, and pH). Hydroperiod and plant traits, notably soluble phenolics, litter C:N ratio, and litter N:P ratio, impacted the likelihood that animals metamorphosed, the number of animals that metamorphosed, and the length of larval period. As hydroperiod decreased, the likelihood that amphibians achieved metamorphosis and the percentage of tadpoles that successfully metamorphosed also decreased. Increases in soluble phenolics, litter N:P ratio, and litter C:N ratio decreased the likelihood that tadpoles achieved metamorphosis, decreased the percentage of tadpoles metamorphosing, decreased metamorph production (total metamorph biomass), and increased the length of larval period. Interestingly, we found no difference in metamorphosis rates and length of larval period between habitats dominated by native and nonnative plants. Our findings have important implications for habitat management. We suggest that to improve habitats for native fauna, managers should focus on assembling a plant community with desirable traits rather than focusing only on plant origin.

  16. Early Archean Spherule Beds-Confirmation of Impact Origin

    NASA Technical Reports Server (NTRS)

    Shukolyukov, A.; Kyte, F. T.; Lugmair, G. W.; Lowe, D. R.; Byerly, G. R.

    2000-01-01

    The oldest record of major impact events on Earth may be a number of early Archean (3.5 to 3.2 Ga) spherule beds that have been identified in the Barberton Greenstone Belt, South Africa. Several field, petrographic, and geochemical criteria distinguish these beds from typical volcanic and clastic sediments. These criteria include the wide geographic distribution of two beds in a variety of depositional environments, the presence of relict quench textures, absence of juvenile volcaniclastic debris within the beds, and extreme enrichment of Ir and other platinum group elements (PGE) as compared to surrounding sediments. Some researchers, however, argued for a terrestrial origin for spherule bed formation, possibly related to volcanism and gold mineralization.

  17. The origins and impact of primate segmental duplications

    PubMed Central

    Marques-Bonet, Tomas; Girirajan, Santhosh; Eichler, Evan E.

    2009-01-01

    Duplicated sequences are substrates for the emergence of new genes and are an important source of genetic instability associated with rare and common diseases. Analyses of primate genomes have shown an increase in the proportion of interspersed segmental duplications (SDs) within the genomes of humans and great apes. This contrasts with other mammalian genomes that seem to have their recently duplicated sequences organized in a tandem configuration. In this review, we focus on the mechanistic origin and impact of this difference with respect to evolution, genetic diversity and primate phenotype. Although many genomes will be sequenced in the future, resolution of this aspect of genomic architecture still requires high quality sequences and detailed analyses. PMID:19796838

  18. The Murray Springs Clovis site, Pleistocene extinction, and the question of extraterrestrial impact.

    PubMed

    Haynes, C Vance; Boerner, J; Domanik, K; Lauretta, D; Ballenger, J; Goreva, J

    2010-03-02

    Some of the evidence for the recent hypothesis of an extraterrestrial impact that caused late Pleistocene megafaunal extinctions [Firestone et al. (2007) Proc Natl Acad Sci USA 104:16016-16021] was based upon samples collected at Murray Springs, a Clovis archaeological site in southeastern Arizona. Here we describe sampling and analyses of magnetic separates from within, above, and below the lower Younger Dryas boundary (LYDB) black mat at Murray Springs, as well as radiation measurements from the LYDB at Murray Springs and two other well-stratified Clovis sites. The main magnetic fraction at Murray Springs is maghemite. Magnetic microspherules have terrestrial origins but also occur as cosmic dust particles. We failed to find iridium or radiation anomalies. The evidence for massive biomass burning at Murray Springs is addressed and found to be lacking. We could not substantiate some of the claims by Firestone and others, but our findings do not preclude a terminal Pleistocene cosmic event.

  19. The Savannah hypotheses: origin, reception and impact on paleoanthropology.

    PubMed

    Bender, Renato; Tobias, Phillip V; Bender, Nicole

    2012-01-01

    The reconstruction of the human past is a complex task characterized by a high level of interdisciplinarity. How do scientists from different fields reach consensus on crucial aspects of paleoanthropological research? The present paper explores this question through an historical analysis of the origin, development, and reception of the savannah hypotheses (SHs). We show that this model neglected to investigate crucial biological aspects which appeared to be irrelevant in scenarios depicting early hominins evolving in arid or semi-arid open plains. For instance, the exploitation of aquatic food resources and other aspects of hominin interaction with water were largely ignored in classical paleoanthropology. These topics became central to alternative ideas on human evolution known as aquatic hypotheses. Since the aquatic model is commonly regarded as highly controversial, its rejection led to a stigmatization of the whole spectrum of topics around water use in non-human hominoids and hominins. We argue that this bias represents a serious hindrance to a comprehensive reconstruction of the human past. Progress in this field depends on clear differentiation between hypotheses proposed to contextualize early hominin evolution in specific environmental settings and research topics which demand the investigation of all relevant facets of early hominins' interaction with complex landscapes.

  20. A One-Day Dental Faculty Workshop in Writing Multiple-Choice Questions: An Impact Evaluation.

    PubMed

    AlFaris, Eiad; Naeem, Naghma; Irfan, Farhana; Qureshi, Riaz; Saad, Hussain; Al Sadhan, Ra'ed; Abdulghani, Hamza Mohammad; Van der Vleuten, Cees

    2015-11-01

    Long training workshops on the writing of exam questions have been shown to be effective; however, the effectiveness of short workshops needs to be demonstrated. The aim of this study was to evaluate the impact of a one-day, seven-hour faculty development workshop at the College of Dentistry, King Saud University, Saudi Arabia, on the quality of multiple-choice questions (MCQs). Kirkpatrick's four-level evaluation model was used. Participants' satisfaction (Kirkpatrick's Level 1) was evaluated with a post-workshop questionnaire. A quasi-experimental, randomized separate sample, pretest-posttest design was used to assess the learning effect (Kirkpatrick's Level 2). To evaluate transfer of learning to practice (Kirkpatrick's Level 3), MCQs created by ten faculty members as a result of the training were assessed. To assess Kirkpatrick's Level 4 regarding institutional change, interviews with three key leaders of the school were conducted, coded, and analyzed. A total of 72 course directors were invited to and attended some part of the workshop; all 52 who attended the entire workshop completed the satisfaction form; and 22 of the 36 participants in the experimental group completed the posttest. The results showed that all 52 participants were highly satisfied with the workshop, and significant positive changes were found in the faculty members' knowledge and the quality of their MCQs with effect sizes of 0.7 and 0.28, respectively. At the institutional level, the interviews demonstrated positive structural changes in the school's assessment system. Overall, this one-day item-writing faculty workshop resulted in positive changes at all four of Kirkpatrick's levels; these effects suggest that even a short training session can improve a dental school's assessment of its students.

  1. Do the Ubangui diamonds originate from a giant impact?

    NASA Astrophysics Data System (ADS)

    Shelkov, D.; Milledge, H. J.; Verchovsky, A. B.; Hutchison, R.; Collinson, D. W.; Pillinger, C. T.

    1994-07-01

    Carbonado wa first recognized as a form of polycrystalline diamond as long ago as the 1840s, when it was discovered and mined as a placer mineral in Brazil. It is now known from a number of other sources, where it is colloquially known as 'carbons.' Common to all these samples is the fact that they occur in alluvial deposits far from primary diamond-bearing rocks such as kimberlite and lamporite. Several authors have suggested that carbonado might have a crustal origin. Recently, it has been proposed that a magnetic anomaly spread over 700,000 sq km of Central Africa might be interpreted as a crater formed by an impact that occurred in sedimentary rocks during Precambrian times; if authenticated this would be the largest impact feature recognized to date. Such a hypothesis makes the investigation of Ubangui diamonds and other carbonados worhtwhile. We considered isotopic systematics and other properties of a variety of intact Ubangui carbons. Because of their importance as grinding and polishing materials microcrystalline diamonds are usually crushed before marketing; the stones we obtained were not and showed a surface rind with a texture very reminiscent of a fusion crust. We have now made C isotopic measurements on five approximately centimeter-sized specimens. We have also begun to study N and its isotopes in carbonados. The results were comparable to data obtained for Brazilian carbonados. So far we have not detected any differences for N between the heavy C diamond and the rest of our samples.

  2. "The Question Which Has Puzzled, and Still Puzzles": How American Indian Authors Challenged Dominant Discourse about Native American Origins in the Nineteenth Century

    ERIC Educational Resources Information Center

    Howey, Meghan C. L.

    2010-01-01

    This article examines the ways American Indian authors, particularly three contemporary Anishinaabeg writers, engaged with the question of Native American origins during the racially polarized project of "imagining" the nation of the United States throughout the 19th century. In this article, the author argues that American Indian…

  3. Treatment of Scores of Questionable Validity: The Origins and Development of the ETS Board of Review--ETS Archives Occasional Paper.

    ERIC Educational Resources Information Center

    Saretzky, Gary D.

    This report provides historical background on the origins, development and procedures, of Educational Testing Service's (ETS's) Board of Review. Established in 1969, the Board of Review makes final decisions for all test scores of questionable validity. ETS cancels or withholds scores believed to be invalid. Reasons for invalid scores range from…

  4. Impact of Question-Answering Tasks on Search Processes and Reading Comprehension

    ERIC Educational Resources Information Center

    Cerdan, Raquel; Vidal-Abarca, Eduardo; Martinez, Tomas; Gilabert, Ramiro; Gil, Laura

    2009-01-01

    This study examined the effect of (a) high- and low-level questions and (b) reading the text before the questions asked on performance, delayed text recall, and deep text comprehension, as well as on specific text-inspection patterns. Participants were 37 undergraduate students who answered either high- or low-level questions using the software…

  5. The Impact of a Question-Embedded Video-Based Learning Tool on E-Learning

    ERIC Educational Resources Information Center

    Vural, Omer Faruk

    2013-01-01

    In this study, it is mainly focused on investigating the effect of question-embedded online interactive video environment on student achievement. A quasi-experimental design was development to compare the effectiveness of a question-embedded interactive video environment (QVE) and an interactive video environment without the question component…

  6. Soil moisture-precipitation coupling: observations question an impact on precipitation occurrence in North America

    NASA Astrophysics Data System (ADS)

    Guillod, Benoit P.; Orlowsky, Boris; Miralles, Diego; Dolman, Han; Reichstein, Markus; Teuling, Adriaan J.; Van den Hurk, Bart; Buchmann, Nina; Seneviratne, Sonia I.

    2013-04-01

    The coupling between soil moisture and convective precipitation through indirect mechanisms (e.g. boundary-layer growth and convection triggering) remains a key challenge out of numerous aspects on the interactions between the land surface and precipitation. In particular, how surface turbulent fluxes (sensible, latent heat fluxes and their partitioning) impact the occurrence of rainfall is poorly understood, due to the number and diversity of the processes involved. Here we explore the relationship between Evaporative Fraction (EF) and precipitation occurrence on the daily time scale. We apply a recently developed method (Findell et al., 2011) to observational data in North America: EF derived from FLUXNET sites and from GLEAM (satellite-based estimates), and radar precipitation data from NEXRAD. We then compare the resulting estimate of land-precipitation coupling to the NARR reanalysis (North American Regional Reanalysis). While a strong relationship is found in NARR, observations do not confirm a strong impact of EF on precipitation occurrence (i.e., no significant coupling is found). Further analyses show that, while precipitation data from NARR and NEXRAD agree well, EF data from the different sources differ widely and lead to different coupling. This questions the existence of a positive coupling between EF and precipitation occurrence in North America and highlights the need for more reliable datasets of high spatial and temporal resolution to fully quantify the strength of such land-surface atmosphere coupling. References: Findell, K. L., P. Gentine, B. R. Lintner, and C. Kerr. 2011. Probability of afternoon precipitation in eastern United States and Mexico enhanced by high evaporation. Nature Geosci, 4, 434-439.

  7. An Impact Origin for Surface Minerals on Ceres

    NASA Astrophysics Data System (ADS)

    Zolotov, M. Y.

    2013-12-01

    The dwarf planet Ceres is the largest body in the main asteroid belt with a hydrated dark rocky surface and an uncertain internal structure [1,2]. Spectra of Ceres in the near- and mid-infrared ranges show that surface materials may not contain abundant serpentine, saponite, sulfates, olivine, pyroxenes, and organic matter [2,3], which are common in carbonaceous chondrites. However, brucite, Mg carbonates, cronstedtite, and magnetite could be abundant and indicate aqueous processes [2,3]. The formation of abundant brucite, carbonates, and cronstedtite requires open-system low-temperature conditions characterized by elevated water/rock ratios and low fugacities of hydrogen and carbon dioxide. The observed mineralogy is more consistent with a near-surface origin than with a formation within Ceres or on planetesimals. The instability of aqueous solutions at the surface of Ceres implies mineral deposition during transient events of fluidal activity. But a warming of near-surface rocks by thermal processes in the interior requires dehydration of rocks, which is not consistent with the low density of Ceres. The lack of low-solubility sulfates in surface materials does not indicate percolation of interior fluids. Carbonate-bearing fluids may not percolate to the cold surface, especially if Ceres had undergone water-rock differentiation [1,4]. The lack of serpentine in surface materials does not indicate a formation of brucite through aqueous alteration of olivine-rich rocks. Though, the observed minerals could form in impact collisions of ice-rich targets and/or impactors. OH-bearing phases may condense from water-rich impact plumes [5]. Brucite and Mg carbonates could form through hydrolysis and carbonation of condensed MgO formed through evaporation of silicates. Apparently abundant carbonates may indicate an ample oxidation of organics. Ferric iron in magnetite and cronstedtite agrees with water-rich and oxidizing impact settings [5]. Turbulent and disequilibrium

  8. On-Line Mathematics Assessment: The Impact of Mode on Performance and Question Answering Strategies

    ERIC Educational Resources Information Center

    Johnson, Martin; Green, Sylvia

    2006-01-01

    The transition from paper-based to computer-based assessment raises a number of important issues about how mode might affect children's performance and question answering strategies. In this project 104 eleven-year-olds were given two sets of matched mathematics questions, one set on-line and the other on paper. Facility values were analyzed to…

  9. Questioning the Questions

    ERIC Educational Resources Information Center

    Tienken, Christopher H.; Goldberg, Stephanie; DiRocco, Dominic

    2010-01-01

    Historical accounts of questioning used in the education process trace back to Socrates. One of the best examples of his use of questioning is found in Plato's "The Republic." Socrates used a series of strategic questions to help his student Glaucon come to understand the concept of justice. Socrates purposefully posed a series of…

  10. Questioning the Questions

    ERIC Educational Resources Information Center

    Tienken, Christopher H.; Goldberg, Stephanie; DiRocco, Dominic

    2009-01-01

    Well-known historical accounts of questioning used in the education process trace back to Socrates. One of the best examples of his use of questioning is found in Plato's classic work "The Republic" (2003). Today, teachers still use questions as one way to help students develop productive thinking skills and to understand concepts and topics.…

  11. Positive vs. Negative: The Impact of Question Polarity in Voting Advice Applications

    PubMed Central

    Krouwel, André; van de Pol, Jasper; de Vreese, Claes

    2016-01-01

    Online Voting Advice Applications (VAAs) are survey-like instruments that help citizens to shape their political preferences and compare them with those of political parties. Especially in multi-party democracies, their increasing popularity indicates that VAAs play an important role in opinion formation for citizens, as well as in the public debate prior to elections. Hence, the objectivity and transparency of VAAs are crucial. In the design of VAAs, many choices have to be made. Extant research in survey methodology shows that the seemingly arbitrary choice to word questions positively (e.g., ‘The city council should allow cars into the city centre’) or negatively (‘The city council should ban cars from the city centre’) systematically affects the answers. This asymmetry in answers is in line with work on negativity bias in other areas of linguistics and psychology. Building on these findings, this study investigated whether question polarity also affects the answers to VAA statements. In a field experiment (N = 31,112) during the Dutch municipal elections we analysed the effects of polarity for 16 out of 30 VAA statements with a large variety of linguistic contrasts. Analyses show a significant effect of question wording for questions containing a wide range of implicit negations (such as ‘forbid’ vs. ‘allow’), as well as for questions with explicit negations (e.g., ‘not’). These effects of question polarity are found especially for VAA users with lower levels of political sophistication. As these citizens are an important target group for Voting Advice Applications, this stresses the need for VAA builders to be sensitive to wording choices when designing VAAs. This study is the first to show such consistent wording effects not only for political attitude questions with implicit negations in VAAs, but also for political questions containing explicit negations. PMID:27723776

  12. The impact of definition and question order on the prevalence of bullying victimization using student self-reports.

    PubMed

    Huang, Francis L; Cornell, Dewey G

    2015-12-01

    Accurate measurement is essential to determining the prevalence of bullying and evaluating the effectiveness of intervention efforts. The most common measurement approach is through anonymous self-report surveys, but previous studies have suggested that students do not adhere to standard definitions of bullying and may be influenced by the order of questions about types of victimization. In the current study, we have presented findings from 2 randomized experiments designed to determine (a) the impact of using or not using a definition of bullying and (b) asking about general versus specific types of bullying victimization and how the order of these questions affects victimization-prevalence rates. The study was conducted using a sample of 17,301 students attending 119 high schools. Findings indicate that the use of a definition had no impact on prevalence rates, but asking specific bullying-victimization questions (e.g., "I have been verbally bullied at school") prior to general bullying-victimization questions (e.g., "I have been bullied at school"), resulted in a 29-76% increase in victimization-prevalence rates. Results suggest that surveys that ask general-to-specific bullying-victimization questions, such as those found in national and international surveys, may be underreporting bullying victimization.

  13. Unreviewed Disposal Question Evaluation: Impact of New Information since 2008 PA on Current Low-Level Solid Waste Operations

    SciTech Connect

    Flach, G.; Smith, F.; Hamm, L.; Butcher, T.

    2014-10-06

    Solid low-level waste disposal operations are controlled in part by an E-Area Low-Level Waste Facility (ELLWF) Performance Assessment (PA) that was completed by the Savannah River National Laboratory (SRNL) in 2008 (WSRC 2008). Since this baseline analysis, new information pertinent to disposal operations has been identified as a natural outcome of ongoing PA maintenance activities and continuous improvement in model simulation techniques (Flach 2013). An Unreviewed Disposal Question (UDQ) Screening (Attachment 1) has been initiated regarding the continued ability of the ELLWF to meet Department of Energy (DOE) Order 435.1 performance objectives in light of new PA items and data identified since completion of the original UDQ Evaluation (UDQE). The present UDQE assesses the ability of Solid Waste (SW) to meet performance objectives by estimating the influence of new information items on a recent sum-of-fractions (SOF) snapshot for each currently active E-Area low-level waste disposal unit. A final SOF, as impacted by this new information, is projected based on the assumptions that the current disposal limits, Waste Information Tracking System (WITS) administrative controls, and waste stream composition remain unchanged through disposal unit operational closure (Year 2025). Revision 1 of this UDQE addresses the following new PA items and data identified since completion of the original UDQE report in 2013: New Kd values for iodine, radium and uranium; Elimination of cellulose degradation product (CDP) factors; Updated radionuclide data; Changes in transport behavior of mobile radionuclides; Potential delay in interim closure beyond 2025; and Component-in-grout (CIG) plume interaction correction. Consideration of new information relative to the 2008 PA baseline generally indicates greater confidence that PA performance objectives will be met than indicated by current SOF metrics. For SLIT9, the previous prohibition of non-crushable containers in revision 0

  14. Values in translation: how asking the right questions can move translational science toward greater health impact.

    PubMed

    Kelley, Maureen; Edwards, Kelly; Starks, Helene; Fullerton, Stephanie M; James, Rosalina; Goering, Sara; Holland, Suzanne; Disis, Mary L; Burke, Wylie

    2012-12-01

    The speed and effectiveness of current approaches to research translation are widely viewed as disappointing given small gains in real population health outcomes despite huge investments in basic and translational science. We identify critical value questions-ethical, social, economic, and cultural-that arise at moments throughout the research pathway. By making these questions visible, and promoting discussion of them with diverse stakeholders, we can facilitate handoffs along the translational pathway and increase uptake of effective interventions. Who is involved with those discussions will determine which research projects, populations, and methods get prioritized. We argue that some upfront investment in community and interdisciplinary engagement, shaped by familiar questions in ethics, social justice, and cultural knowledge, can save time and resources in the long run because interventions and strategies will be aimed in the right direction, that is, toward health improvements for all.

  15. How to Improve Your Impact Factor: Questioning the Quantification of Academic Quality

    ERIC Educational Resources Information Center

    Smeyers, Paul; Burbules, Nicholas C.

    2011-01-01

    A broad-scale quantification of the measure of quality for scholarship is under way. This trend has fundamental implications for the future of academic publishing and employment. In this essay we want to raise questions about these burgeoning practices, particularly how they affect philosophy of education and similar sub-disciplines. First,…

  16. Students' Questions and Discursive Interaction: Their Impact on Argumentation during Collaborative Group Discussions in Science

    ERIC Educational Resources Information Center

    Chin, Christine; Osborne, Jonathan

    2010-01-01

    This study investigated the potential of students' written and oral questions both as an epistemic probe and heuristic for initiating collaborative argumentation in science. Four classes of students, aged 12-14 years from two countries, were asked to discuss which of two graphs best represented the change in temperature as ice was heated to steam.…

  17. On the Impact of Adaptive Test Question Selection for Learning Efficiency

    ERIC Educational Resources Information Center

    Barla, Michal; Bielikova, Maria; Ezzeddinne, Anna Bou; Kramar, Tomas; Simko, Marian; Vozar, Oto

    2010-01-01

    In this paper we present a method for adaptive selection of test questions according to the individual needs of students within a web-based educational system. It functions as a combination of three particular methods. The first method is based on the course structure and focuses on the selection of the most appropriate topic for learning. The…

  18. The Impact of the Document-Based Question on the Teaching of United States History.

    ERIC Educational Resources Information Center

    Rothschild, Eric

    2000-01-01

    Provides historical information on the Document-Based Question (DBQ) that has been a part of the Advanced Placement (AP) U.S. history examination since 1973. Focuses on the effects that DBQ had on course content and teaching methods. Addresses the new changes made with the redesign of the DBQ in 1982. (CMK)

  19. A question of origin: dioxin-like PCBs and their relevance in stock management of European eels.

    PubMed

    Freese, Marko; Sühring, Roxana; Pohlmann, Jan-Dag; Wolschke, Hendrik; Magath, Victoria; Ebinghaus, Ralf; Hanel, Reinhold

    2016-01-01

    The stock of European Eel (Anguilla anguilla L.) has reached an all-time low in 2011. Spawner quality of mature eels in terms of health status and fitness is considered one of the key elements for successful migration and reproduction. Dioxin-like Polychlorinated Biphenyls (dl-PCBs) are known persistent organic pollutants potentially affecting the reproductive capability and health status of eels throughout their entire lifetime. In this study, muscle tissue samples of 192 European eels of all continental life stages from 6 different water bodies and 13 sampling sites were analyzed for contamination with lipophilic dl-PCBs to investigate the potential relevance of the respective habitat in light of eel stock management. Results of this study reveal habitat-dependent and life history stage-related accumulation of targeted PCBs. Sum concentrations of targeted PCBs differed significantly between life stages and inter-habitat variability in dl-PCB levels and -profiles was observed. Among all investigated life stages, migrant silver eels were found to be the most suitable life history stage to represent their particular water system due to habitat dwell-time and their terminal contamination status. With reference to a possible negative impact of dl-PCBs on health and the reproductive capability of eels, it was hypothesized that those growing up in less polluted habitats have a better chance to produce healthy offspring than those growing up in highly polluted habitats. We suggest that the contamination status of water systems is fundamental for the life cycle of eels and needs to be considered in stock management and restocking programs.

  20. Noachian and Hesperian modification of the original Chryse impact basin topography

    NASA Technical Reports Server (NTRS)

    Stockman, Stephanie; Frey, Herbert

    1994-01-01

    We propose a new center (35.5 W, 32.5 N) and ring assignment for the original Chryse impact basin based on photogeologic mapping and re-examination of the published geology. Noachian features in the Chryse Planitia area are the best indicators of the original ancient multiringed impact structure. While other workers have centered the Chryse impact on the topographic low associated with Hesperian volcanic and fluvial deposits, we suggest that the center of the original Noachian-age excavation cavity was located 800 km farther NE, and the basin topography was significantly modified over time.

  1. The Big Money Question: Action Research Projects Give District a Clear Picture of Professional Learning's Impact

    ERIC Educational Resources Information Center

    Dill-Varga, Barbara

    2015-01-01

    How do districts know if the resources they have allocated to support professional learning in their school district are actually improving the quality of teaching and impacting student performance? In an increasingly challenging financial environment, this is important to know. In this article, a Chicago-area district facing a budget deficit…

  2. Apollo 15 yellow impact glasses: Chemistry, petrology, and exotic origin

    SciTech Connect

    Delano, J.W.; Lindsley, D.H.; Ma, M.; Schmitt, R.A.

    1982-11-15

    The Apollo 15 yellow impact glasses are characterized by moderate TiO/sub 2/ (approx.4.8%) and high abundances of the large ion lithophile elements (e.g., K, P, Hf, Th, REE). Since the chemistry of these glasses cannot be duplicated by any combination of local components presently known to occur at the Apollo 15 landing site, these yellow glasses seem to be exotic to that area. Chemical and petrologic constraints suggest that these samples were produced by impact melting of an immature mare regolith developed upon an unusual variety of mare basalt. We speculate that the target basalt were the youngest lava flows known to exist on the moon (i.e., Eratosphenian-age lavas in Oceanus Procellarum and Mare Imbrium). Specific tests are proposed for evaluating this provocative hypothesis.

  3. Origin of asteroid rotation rates in catastrophic impacts.

    PubMed

    Love, S G; Ahrens, T J

    1997-03-13

    The rotation rates of asteroids, which are deduced from periodic fluctuations in their brightnesses, are controlled by mutual collisions. The link between asteroid spin and collision history is usually made with reference to impact experiments on centimetre-scale targets, where material strength governs the impact response. Recent work, however, indicates that for objects of the size of most observed asteroids (> or = 1 km in diameter), gravity rather than intrinsic strength controls the dynamic response to collisions. Here we explore this idea by modelling the effect of impacts on large gravitating bodies. We find that the fraction of a projectile's angular momentum that is retained by a target asteroid is both lower and more variable than expected from laboratory experiments, with spin evolution being dominated by 'catastrophic' collisions that eject approximately 50 per cent of the target's mass. The remnant of an initially non-rotating silicate asteroid that suffers such a collision rotates at a rate of approximately 2.9 per day, which is close to the observed mean asteroid rotation rate of approximately 2.5 d-1. Moreover, our calculations suggest that the observed trend in the mean spin frequency for different classes of asteroids (2.2 d-1 for C-type asteroids, 2.5 d-1 for S-type, and 4.0 d-1 for M-type) is due to increasing mean density, rather than increasing material strength.

  4. Enfuvirtide for nurses: answering patient questions on activity, safety, and lifestyle impact.

    PubMed

    Glutzer, Eileen; Lalezari, Jacob P

    2005-01-01

    The introduction of enfuvirtide, the first self-administered parenteral antiretroviral, has reinforced the HIV nurse's role in patient education, support, and motivation. Detailed background knowledge of the drug will assist nurses to provide answers to common questions and concerns raised during patient training. Three particular concerns often raised are curiosity about how enfuvirtide works, what side effects can be expected, and how these and the process of daily injection will affect the patient's daily routine. This brief review is designed to provide nurse-educators with clinical information on these three issues to help them better provide the answers patients will need to help them feel confident self-administering this new drug.

  5. DETECTING AND MITIGATING THE ENVIRONMENTAL IMPACT OF FECAL PATHOGENS ORIGINATING FROM CONFINED ANIMAL FEEDING OPERATIONS: REVIEW

    EPA Science Inventory

    This report presents a review of literature regarding the potential impact of fecal pathogens originating from animal agriculture in the United States. Livestock production and dairy operations continue their trend toward larger and more concentrated facilities. These operations ...

  6. A Question of Questions.

    ERIC Educational Resources Information Center

    Fenwick, John; McMillan, Rod

    In a conventional teaching situation, a lecturer may use a wide range of questioning techniques aimed at helping students to become active learners. In distance learning, students are often isolated and have limited opportunities for interaction in a social learning environment. Hence, learning strategies in distance learning need to be structured…

  7. A giant impact origin of Pluto-Charon.

    PubMed

    Canup, Robin M

    2005-01-28

    Pluto and its moon, Charon, are the most prominent members of the Kuiper belt, and their existence holds clues to outer solar system formation processes. Here, hydrodynamic simulations are used to demonstrate that the formation of Pluto-Charon by means of a large collision is quite plausible. I show that such an impact probably produced an intact Charon, although it is possible that a disk of material orbited Pluto from which Charon later accumulated. These findings suggest that collisions between 1000-kilometer-class objects occurred in the early inner Kuiper belt.

  8. Microanalysis of Hypervelocity Impact Residues of Possible Interstellar Origin

    NASA Technical Reports Server (NTRS)

    Stroud, Rhonda M.; Achilles, Cheri; Allen, Carlton; Anasari, Asna; Bajt, Sasa; Bassim, Nabil; Bastien, Ron S.; Bechtel, H. A.; Borg, Janet; Brenker, Frank E.; Bridges, John; Brownlee, Donald E.; Burchell, Mark; Burghammer, Manfred; Butterworth, Anna L.; Changela, Hitesh; Cloetens, Peter; Davis, Andrew M.; Doll, Ryan; Floss, Christine; Flynn, George; Fougeray, Patrick; Frank, David; Sandford, Scott A.; Zolensky, Michael E.

    2012-01-01

    The NASA Stardust spacecraft deployed two collector trays, one dedicated to the collection of dust from Comet Wild 2, and the other for the capture of interstellar dust (ISD). The samples were returned successfully to Earth in 2006, and now provide an unprecedented opportunity for laboratory-based microanalysis of materials from the outer solar system and beyond. Results from the cometary sample studies have demonstrated that Wild 2 contains much more refractory condensate material and much less pristine extra-solar material than expected, which further indicates that there was significant transport of inner solar system materials to the Kuiper Belt in the early solar system [1]. The analysis of the interstellar samples is still in the preliminary examination (PE) phase, due to the level of difficulty in the definitive identification of the ISD features, the overall low abundance, and its irreplaceable nature, which necessitates minimally invasive measurements [2]. We present here coordinated microanalysis of the impact features on the Al foils, which have led to the identification of four impacts that are possibly attributable to interstellar dust. Results from the study of four ISD candidates captured in aerogel are presented elsewhere [2].

  9. Impact Crater Hydrothermal Niches for Life on Mars: Question of Scale

    NASA Technical Reports Server (NTRS)

    Pope, K. O.; Ames, D. E.; Kieffer, S. W.; Ocampo, A. C.

    2000-01-01

    A major focus in the search for fossil life on Mars is on ancient hydrothermal deposits. Nevertheless, remote sensing efforts have not found mineral assemblages characteristic of hydrothermal activity. Future remote sensing work, including missions with higher spatial resolution, may detect localized hydrothermal deposits, but it is possible that dust mantles will prohibit detection from orbit and lander missions will be required. In anticipation of such missions, it is critical to develop a strategy for selecting potential hydrothermal sites on Mars. Such a strategy is being developed for volcanogenic hydrothermal systems, and a similar strategy is needed for impact hydrothermal systems.

  10. Physical impacts of regional climate change in the West African Sahel and the question of desertification

    SciTech Connect

    Nicholson, S.E.; Ba, M.

    1997-11-01

    The question of desertification is examined in the West African Sahel region by considering various physical indicators assumed to accompany this process. The study considers only the past 14 years, since the availability of comprehensive satellite data sets. The physical indicators examined include vegetation cover, surface albedo, soil moisture, wind-borne dust, river flow, lakes, and the ratio of available moisture to vegetation growth. Vegetation cover and albedo are assessed from satellite data. Soil moisture is assessed using a surface hydrologic model. Dust is estimated from visibility measurements. The most important results are that: (1) there is no progressive change in the vegetation cover, (2) an increase of albedo as the region dries up cannot be documented, and (3) there has been a tremendous increase in wind-borne dust over the Sahel. The vegetation cover responds almost directly to rainfall and the movement of the desert boundary corresponds roughly to rainfall fluctuations. The most important meteorological effect of the drought and/or desertification in the Sahel may be the enhanced dust generation, with the region becoming a major global source of atmospheric mineral dust. 5 refs., 7 figs., 1 tab.

  11. Questions concerning the potential impact of glyphosate-based herbicides on amphibians.

    PubMed

    Wagner, Norman; Reichenbecher, Wolfram; Teichmann, Hanka; Tappeser, Beatrix; Lötters, Stefan

    2013-08-01

    Use of glyphosate-based herbicides is increasing worldwide. The authors review the available data related to potential impacts of these herbicides on amphibians and conduct a qualitative meta-analysis. Because little is known about environmental concentrations of glyphosate in amphibian habitats and virtually nothing is known about environmental concentrations of the substances added to the herbicide formulations that mainly contribute to adverse effects, glyphosate levels can only be seen as approximations for contamination with glyphosate-based herbicides. The impact on amphibians depends on the herbicide formulation, with different sensitivity of taxa and life stages. Effects on development of larvae apparently are the most sensitive endpoints to study. As with other contaminants, costressors mainly increase adverse effects. If and how glyphosate-based herbicides and other pesticides contribute to amphibian decline is not answerable yet due to missing data on how natural populations are affected. Amphibian risk assessment can only be conducted case-specifically, with consideration of the particular herbicide formulation. The authors recommend better monitoring of both amphibian populations and contamination of habitats with glyphosate-based herbicides, not just glyphosate, and suggest including amphibians in standardized test batteries to study at least dermal administration.

  12. Chesapeake Bay Crater, Virginia: Confirmation of Impact Origin

    NASA Astrophysics Data System (ADS)

    Koeberl, C.; Reimold, W. U.; Brandt, D.; Poag, C. W.

    1995-09-01

    Poag et al. [1] identified a late Eocene boulder bed in drill cores from southeast Virginia, and interpreted it as an impact-generated tsunami deposit. Seismic studies and other geophysical evidence indicated the existence of a possible impact structure centered at Chesapeake Bay (37 degrees x 15' N and 76 degrees x 04' W), which may be 85-90 km in diameter [2]. Four drill cores have penetrated into the breccia, although none is available from the center of the structure, or reaches basement. A central peak-ring of crystalline rocks with about 25 km diameter is surrounded by a 30 km-wide annular trough and terrace terrane. The trough is filled with polymictic breccia composed mainly of autochthonous sedimentary clasts in a sandy matrix with some angular clasts of granitic and metasedimentary basement rocks [2]. The Chesapeake Bay crater is of special interest, because it is close to the region identified as the possible source region for the North American tektites, is of about the expected size, and has an age identical to that of the tektites [3]. While the source craters for the Central European and Ivory Coast tektite strewn fields are known, the source crater of the North American tektites has remained elusive. A variety of locations were suggested, including Popigai (Siberia), Wanapitei (Canada), Mistastin (Canada), and Bee Bluff (Texas), but all were later discounted. The distribution of the tektites and microtektites in the strewn field suggests that the North American tektite source crater is likely to be located at or near the eastern coast of the North American continent, maybe underwater [4,5]. The location of the Chesapeake Bay structure is in agreement with the area suggested before [4,5]. We have started a petrological and geochemical study of target rocks and breccias from the Chesapeake Bay structure. We analyzed the major and trace element composition of 17 mainly sedimentary samples, for comparison with North American tektite values. 14 of these

  13. Origins of task-specific sensory-independent organization in the visual and auditory brain: neuroscience evidence, open questions and clinical implications.

    PubMed

    Heimler, Benedetta; Striem-Amit, Ella; Amedi, Amir

    2015-12-01

    Evidence of task-specific sensory-independent (TSSI) plasticity from blind and deaf populations has led to a better understanding of brain organization. However, the principles determining the origins of this plasticity remain unclear. We review recent data suggesting that a combination of the connectivity bias and sensitivity to task-distinctive features might account for TSSI plasticity in the sensory cortices as a whole, from the higher-order occipital/temporal cortices to the primary sensory cortices. We discuss current theories and evidence, open questions and related predictions. Finally, given the rapid progress in visual and auditory restoration techniques, we address the crucial need to develop effective rehabilitation approaches for sensory recovery.

  14. Radiative Impacts of Elevated Aerosol Layers from Different Origins

    NASA Astrophysics Data System (ADS)

    Sauer, D. N.; Weinzierl, B.; Gasteiger, J.; Heimerl, K.

    2014-12-01

    Aerosol particles are omnipresent in the Earth's atmosphere and have important impacts on weather and climate by their effects on the atmospheric radiative balance. With the advent of more and more sophisticated representations of atmospheric processes in earth system models, the lack of reliable input data on aerosols leads to significant uncertainties in the prediction of future climate scenarios. In recent years large discrepancies in radiative forcing estimates from aerosol layers in modeling studies have been revealed emphasizing the need for detailed and systematic observations of aerosols. Airborne in-situ measurements represent an important pillar for validating both model results and retrievals of aerosol distributions and properties from remote sensing methods on global scales. However, detailed observations are challenging and therefore are subject to substantial uncertainties themselves. Here we use data from airborne in-situ measurements of elevated aerosol layers from various field experiments in different regions of the world. The data set includes Saharan mineral dust layers over Africa, the Atlantic Ocean and the Caribbean from the SALTRACE and the SAMUM campaigns as well as long-range transported biomass burning aerosol layers from wild fires in the Sahel region and North America measured over the tropical Atlantic Ocean, Europe and the Arctic detected during SAMUM2, CONCERT2011, DC3 and ACCESS 2012. We aim to characterize the effects of the measured aerosol layers, in particular with respect to ageing, mixing state and vertical structure, on the overall atmospheric radiation budget as well as local heating and cooling rates. We use radiative transfer simulations of short and long-wave radiation and aerosol optical properties derived in a consistent way from the in-situ observations of microphysical properties using T-matrix calculations. The results of this characterization will help to improve the parameterization of the effects of elevated

  15. Constraining the Origin of Impact Craters on Al Foils from the Stardust Interstellar Dust Collector

    NASA Technical Reports Server (NTRS)

    Stroud, Rhonda M.; Achilles, Cheri; Allen, Carlton; Ansari, Asna; Bajt, Sasa; Bassim, Nabil; Bastien, Ron S.; Bechtel, H. A.; Borg, Janet; Brenker, Frank E.; Bridges, John; Brownlee, Donald E.; Burchell, Mark; Burghammer, Manfred; Butterworth, Anna L.; Changela, Hitesh; Cloetens, Peter; Davis, Andrew M.; Doll, Ryan; Floss, Christine; Flynn, George; Fougeray, Patrick; Frank, David; Sandford, Scott A.; Zolensky, Michael E.

    2012-01-01

    Preliminary examination (PE) of the aerogel tiles and Al foils from the Stardust Interstellar Dust Collector has revealed multiple impact features. Some are most likely due to primary impacts of interstellar dust (ISD) grains, and others are associated with secondary impacts of spacecraft debris, and possibly primary impacts of interplanetary dust particles (IDPs) [1, 2]. The current focus of the PE effort is on constraining the origin of the individual impact features so that definitive results from the first direct laboratory analysis of contemporary ISD can be reported. Because crater morphology depends on impacting particle shape and composition, in addition to the angle and direction of impact, unique particle trajectories are not easily determined. However, elemental analysis of the crater residues can distinguish real cosmic dust from the spacecraft debris, due to the low cosmic abundance of many of the elements in the spacecraft materials. We present here results from the elemental analysis of 24 craters and discuss the possible origins of 4 that are identified as candidate ISD impacts

  16. National Association of Attorneys General Model Solicitation Act: Its Origin and Impact on Colleges and Universities.

    ERIC Educational Resources Information Center

    Suffern, Kevin A.

    1988-01-01

    The National Association of Attorneys' Model Solicitation Act, which covers college and university fund-raising and has been used for state legislation, is discussed. Its origins and basic concepts, impact on institutions, and reasons for eliminating college and university exemption are examined. (MSE)

  17. Everyone Wins: A Mars-Impact Origin for Carbonaceous Phobos and Deimos

    NASA Technical Reports Server (NTRS)

    Fries, M.; Welzenbach, L.; Steele, A.

    2016-01-01

    Discussions of Phobos' and Deimos' origin(s) tend to feature an orthogonally opposed pair of observations: dynamical studies which favor coalescence of the moons from an orbital debris ring arising from a large impact on Mars; and reflectance spectroscopy of the moons that indicate a carbonaceous composition that is not consistent with Martian surface materials. One way to reconcile this discrepancy is to consider the option of a Mars-impact origin for Phobos and Deimos, followed by surficial decoration of carbon-rich materials by interplanetary dust particles (IDP). The moons experience a high IDP flux because of their location in Mars' gravity well. Calculations show that accreted carbon is sufficient to produce a surface with reflectance spectra resembling carbonaceous chondrites.

  18. Early Impact History and Dynamical Origin of Differentiated Meteorites and Asteroids

    NASA Astrophysics Data System (ADS)

    Scott, E. R. D.; Keil, K.; Goldstein, J. I.; Asphaug, E.; Bottke, W. F.; Moskovitz, N. A.

    Differentiated asteroids and igneous meteorites present numerous challenges to our understanding of the impact and dynamical evolution of asteroids and meteorite parent bodies. Igneous meteorites, including irons, achondrites, and stony-iron meteorites, testify to the prior existence of ~100 differentiated bodies. Destruction of these bodies by hypervelocity impact over 4 G.y. would have required numerous giant impacts, although this is inconsistent with the preservation of Vesta's basaltic crust and the lack of differentiated asteroid families. We review recent advances in elucidating the early chronology of meteorites, spectroscopic observations of likely differentiated asteroids, petrological studies of differentiated meteorites, impact disruption of differentiated planetesimals during accretion, and dynamical scenarios for capturing material into the asteroid belt. Together, these advances suggest a new paradigm in which planetesimals accreted rapidly in the inner solar system and were melted by 26Al less than 2 m.y. after the formation of calcium-aluminum-rich inclusions (CAIs). While molten they were disrupted by grazing hit-and-run impacts during the accretion of planetesimals. Later, when still hot, the survivors were disrupted by hypervelocity impacts. Impact debris from the differentiated bodies was transferred from the newly formed terrestrial planet region to stable orbits in the asteroid belt. This evolutionary history leaves many questions unanswered but suggests new paths for future exploration of the asteroid belt and petrological and isotopic studies of meteorites.

  19. Shocked zircons in the Onaping Formation: Further proof of impact origin

    NASA Technical Reports Server (NTRS)

    Bohor, B. F.; Betterton, W. J.

    1992-01-01

    The Onaping Formation fills the structural basin at Sudbury, Ontario, Canada. This formation is composed of three members: a basal, coarse, mainly quartzitic breccia (Basal Member); a light-colored, heavily included, polymict middle unit (Gray Member); and a similar but dark-colored upper unit (Black Member). Two different origins were proposed for the Onaping: (1) volcanic ash-flow sheet; and (2) impact fall-back ejecta. These origins are critically discussed in a review paper coauthored by proponents of each view.

  20. Apollo 14 glasses of impact origin and their parent rock types.

    NASA Technical Reports Server (NTRS)

    Chao, E. C. T.; Best, J. B.; Minkin, J. A.

    1972-01-01

    Eight chemical groups can be recognized on the basis of studies of more than 200 Apollo 14 glass particles of impact origin. It is found that the major rock type of a highland site is dominated by annealed noritic rocks rather than by anorthosites as previously suggested. Both mafic and salic rock types are associated with the noritic rocks. A number of tables are provided showing the chemical composition of the minerals investigated.

  1. Cumulative impacts of human activities on urban garden soils: origin and accumulation of metals.

    PubMed

    Szolnoki, Zs; Farsang, A; Puskás, I

    2013-06-01

    The concentration of heavy metals and soil properties in fifty urban garden soils of Szeged (SE Hungary) were determined to evaluate the cumulative impacts of urbanization and cultivation on these soils. Using two enrichment factors (EFs) (based on reference horizon; Ti as reference element) and multivariate statistical analysis (PCA), the origin of the studied elements was defined. According to statistical coincidence of EFs confirmed by t-test, anthropogenic enrichment of Cu (EF = 4), Zn (EF = 2.7) and Pb (EF = 2.5) was significant in topsoils. Moreover, PCA also revealed the geogenic origin of Ni, Co, Cr and As and differentiated two groups of the anthropogenic metals [Pb, Zn] [Cu]. Spatial distribution of the metals visualized by GIS reflected the traffic origin of Pb; while based on ANOVA, the anthropogenic source of Cu is relevant (mainly pesticides) and there is a statistically significant difference in its concentration depending on land use.

  2. Shared Storybook Reading in Head Start: Impact of Questioning Styles on the Vocabulary of Hispanic Dual Language Learners

    ERIC Educational Resources Information Center

    Walsh, Bridget A.; Sánchez, Claudia; Burnham, Melissa M.

    2016-01-01

    This study examined various ways of asking questions about target vocabulary words during shared storybook reading with young Hispanic dual language learners enrolled in Head Start. The study examined the demand level and placement of adults' questions during shared storybook reading. The research design incorporated five conditions; namely,…

  3. To Question or Not to Question: That Seems to Be the Question.

    ERIC Educational Resources Information Center

    Bradtmueller, Weldon G.; Egan, James B.

    Research on the effects of questioning in the classroom has explored the placement, timing, type, and social impact of questions. Principles of good questioning include the following: (1) well-stated questions should be concise, clear, and complete; (2) questions should be topical in nature, requiring a complex answer; (3) yes or no questions…

  4. The Shedler-Westen Assessment Procedure (SWAP): Evaluating Psychometric Questions about Its Reliability, Validity, and Impact of Its Fixed Score Distribution

    ERIC Educational Resources Information Center

    Blagov, Pavel S.; Bi, Wu; Shedler, Jonathan; Westen, Drew

    2012-01-01

    The Shedler-Westen Assessment Procedure (SWAP) is a personality assessment instrument designed for use by expert clinical assessors. Critics have raised questions about its psychometrics, most notably its validity across observers and situations, the impact of its fixed score distribution on research findings, and its test-retest reliability. We…

  5. Impact Constraints on the Age and Origin of the Crustal Dichotomy on Mars

    NASA Technical Reports Server (NTRS)

    Frey, H. V.

    2004-01-01

    MOLA data have revealed a large population of "Quasi-Circular Depressions" (QCDs) with little or no visible expression in image data. These likely buried impact basins have important implications for the age of the lowland crust, how that compares with original highland crust, and when and how the crustal dichotomy may have formed. The buried lowlands are of Early Noachian age, likely slightly younger than the buried highlands but older than the exposed (visible) highland surface. A depopulation of large visible basins at diameters 800 to 1300 km suggests some global scale event early in martian history, maybe related to the formation of the lowlands andor the development of Tharsis. A suggested early disappearance of the global magnetic field can be placed within a temporal sequence of formation of the very largest impact basins. The global field appears to have disappeared at about the time the lowlands formed. It seems likely the topographic crustal dichotomy was produced very early in martian history by processes which operated very quickly. This and the preservation of large relic impact basins in the north- em hemisphere, which themselves can account for the lowland topography, suggest that large impacts played the major role in the origin Mars fundamental crustal feature.

  6. Impact Constraints on the Age and Origin of the Crustal Dichotomy on Mars

    NASA Technical Reports Server (NTRS)

    Frey, Herbert V.

    2004-01-01

    MOLA data have revealed a large population of 'Quasi-Circular Depressions' (QCDs) with little or no visible expression in image data. These likely buried impact basins have important implications for the age of the lowland crust, how that compares with original highland crust, and when and how the crustal dichotomy may have formed. The buried lowlands are of Early Noachian age, likely slightly younger than the buried highlands but older than the exposed (visible) highland surface. A depopulation of large visible basins at diameters 800 to 1300 km suggests some global scale event early in martian history, maybe related to the formation of the lowlands and/or the development of Tharsis. A suggested early disappearance of the global magnetic field can be placed within a temporal sequence of formation of the very largest impact basins. The global field appears to have disappeared at about the time the lowlands formed. It seems likely the topographic crustal dichotomy was produced very early in martian history by processes which operated very quickly. This and the preservation of large relic impact basins in the northern hemisphere, which themselves can account for the lowland topography, suggest that large impacts played the major role in the origin Mars fundamental crustal feature.

  7. Evidence for an Extraterrestrial Impact Origin of the Carolina Bays on the Atlantic Coast of North America

    NASA Astrophysics Data System (ADS)

    Howard, G. A.; West, A.; Firestone, R. B.; Kennett, J. P.; Kimbel, D.; Newell, W.; Kobres, R.

    2007-05-01

    The Carolina Bays, one of the most conspicuous geomorphic features on the Atlantic Coastal Plain of the United States, are a group of about 500,000, oriented, crater-like, elliptical lakes, wetlands, and depressions, ranging from a few dozen meters to about 11 km in length. Although long proposed as impact structures (Melton and Schriever, 1933; Prouty, 1934), this origin for the Carolina Bays has remained controversial mainly because of an apparent absence of associated extraterrestrial materials. Analyses of Bay orientation showed that their long axes converge near the Great Lakes, suggesting that an impact or airburst over that region may have formed the Bays (Eyton and Parkhurst, 1975). However, Bays dates have been reported over a wide range, calling into question whether all Carolina Bays could have formed simultaneously, although this issue remains unresolved and controversial. Many Bay researchers, who subscribe to widely differing theories, agree that modern Carolina Bays have been subject to repeated modification and that they most likely evolved from some type of ancestral depressions. Now for the first time, we present conclusive geochemical and sedimentary evidence in support of an extraterrestrial connection for the Carolina Bays. Analyses of sediment from the rim sands and basins of fifteen Bays, widely distributed across North and South Carolina, reveal anomalously high abundances of microspherules, iridium, fullerenes with ET helium, carbon spherules, glass-like carbon, and other potential markers for extraterrestrial impact. No such markers were found in paleosols beneath the rim sands or basal sediments of the Bays examined. The assemblage of geochemical and sediment signatures of extraterrestrial impact found in Bay sediments are essentially the same as in the pan-North-American Younger Dryas impact boundary layer (the YDB), dated at 12.9 ka. We hypothesize that at least some Bays were formed by the YD impact during the last deglacial, and we

  8. Are Extracted Materials Truly Representative of Original Samples? Impact of C18 Extraction on CDOM Optical and Chemical Properties.

    PubMed

    Andrew, Andrea A; Del Vecchio, Rossana; Zhang, Yi; Subramaniam, Ajit; Blough, Neil V

    2016-01-01

    Some properties of dissolved organic matter (DOM) and chromophoric dissolved organic matter (CDOM) can be easily measured directly on whole waters, while others require sample concentration and removal of natural salts. To increase CDOM content and eliminate salts, solid phase extraction (SPE) is often employed. Biases following extraction and elution are inevitable, thus raising the question of how truly representative the extracted material is of the original. In this context, we investigated the wavelength dependence of extraction efficiency for C18 cartridges with respect to CDOM optical properties using samples obtained from the Middle Atlantic Bight (MAB) and the Equatorial Atlantic Ocean (EAO). Further, we compared the optical changes of C18 extracts and the corresponding whole water following chemical reduction with sodium borohydride (NaBH4). C18 cartridges preferentially extracted long-wavelength absorbing/emitting material for samples impacted by riverine input. Extraction efficiency overall decreased with offshore distance away from riverine input. Spectral slopes of C18-OM samples were also almost always lower than those of their corresponding CDOM samples supporting the preferential extraction of higher molecular weight absorbing material. The wavelength dependence of the optical properties (absorption, fluorescence emission, and quantum yield) of the original water samples and their corresponding extracted material were very similar. C18 extracts and corresponding water samples further exhibited comparable optical changes following NaBH4 reduction, thus suggesting a similarity in nature (structure) of the optically active extracted material, independent of geographical locale. Altogether, these data suggested a strong similarity between C18 extracts and corresponding whole waters, thus indicating that extracts are representative of the CDOM content of original waters.

  9. Impact of iron contamination in multicrystalline silicon solarcells: origins, chemical states, and device impacts

    SciTech Connect

    Buonassisi, Tonio; Heuer, Matthias; Istratov, Andrei A.; Marcus,Matthew A.; Jonczyk, Ralf; Lai, Barry; Cai, Zhonghou; Schindler, Roland; Weber, Eicke R.

    2004-11-08

    Synchrotron-based microprobe techniques have been applied to study the distribution, size, chemical state, and recombination activity of Fe clusters in two types of mc-Si materials: block cast mc-Si, and AstroPower Silicon Film(TM) sheet material. In sheet material, high concentrations of metals were found at recombination-active, micron-sized intragranular clusters consisting of micron and sub-micron sized particles. In addition, Fe nanoparticles were located in densities of {approx}2'107 cm-2 along recombination-active grain boundaries. In cast mc-Si,two types of particles were identified at grain boundaries: (1) micron-sized oxidized Fe particles accompanied by other metals (Cr, Mn, Ca, Ti), and (2) a higher number of sub-micron FeSi2 precipitates that exhibited a preferred orientation along the crystal growth direction. In both materials, it is believed that the larger Fe clusters are inclusions of foreign particles, from which Fe dissolves in the melt to form the smaller FeSi2 nanoprecipitates, which by virtue of their more homogeneous distribution are deemed more dangerous to solar cell device performance. Based on this understanding, strategies proposed to reduce the impact of Fe on mc-Si electrical properties include gettering, passivation, and limiting the dissolution of foreign Fe-rich particles in the melt.

  10. Origin of orbital debris impacts on Long Duration Exposure Facility's (LDEF) trailing surfaces

    NASA Technical Reports Server (NTRS)

    Kessler, Donald J.

    1992-01-01

    Orbital debris tracked by the US Space Command is mostly in near circular orbit around the Earth. If small debris were in the same types of orbits, there would be very few orbital debris impacts on the Long Duration Exposure Facility's (LDEF's) trailing surfaces. However, at least 15 percent of the impacts found on the trailing A03 gold surface was found to be orbital debris impacts. This measurement suggests that the orbital distribution of small debris is not the same as that of larger debris. Although this is not a total surprise, since modelling of satellite breakups has predicted different distributions, it does raise questions as to what types of orbits could be responsible for these impacts. A model was developed to explain these LDEF results. The model calculates the expected debris impact crater distribution around LDEF, as a function of debris orbital parameters. The results show that only low inclination and highly elliptical orbits could be responsible for these impacts. The most common object left in this type of orbit is an orbital transfer stage, used by the US and ESA to place objects into geosynchronous orbit, and inclinations near 28 and 7 degrees for the US and ESA, respectively. Even large fragments from satellites, which break up in these types of orbits, are difficult to observe from the ground; consequently, little is known about the number and characteristics of breakups in these orbits. The LDEF data suggest that these objects are breaking up. The LDEF data also suggest that the ratio of the contribution of small debris from this type of orbit to the contribution from circular orbits is about an order of magnitude larger than the same ratio for debris tracked by the US Space Command.

  11. Question Mapping

    ERIC Educational Resources Information Center

    Martin, Josh

    2012-01-01

    After accepting the principal position at Farmersville (TX) Junior High, the author decided to increase instructional rigor through question mapping because of the success he saw using this instructional practice at his prior campus. Teachers are the number one influence on student achievement (Marzano, 2003), so question mapping provides a…

  12. Curiosity Questions

    ERIC Educational Resources Information Center

    Nelsen, Jane; DeLorenzo, Chip

    2010-01-01

    Have you ever found yourself lecturing a child, with the best of intentions, in an attempt to help him or her learn a lesson or process a situation in a manner that you feel will be productive? Curiosity questions, which the authors also call What and How questions, help children process an experience, event, or natural consequence so that they…

  13. The origin of the moon and the single impact hypothesis. III

    NASA Technical Reports Server (NTRS)

    Benz, W.; Cameron, A. G. W.; Melosh, H. J.

    1989-01-01

    Calculations of the single-impact hypothesis for the origin of the moon were performed using the smoothed particle hydrodynamics (SPH) code developed by Benz et al. (1986). Results are presented from calculations of a relatively low-level collision with an impactor mass in the range 6-8 x 10 to the 26th g. Several runs of the calculations are conducted for this mass range with variations in the SPH code, the equation of state, and the initial planetary models. The effects of these variations are compared. It is found that the orbiting mass is injected by gravitational torques.

  14. Chicxulub Impact and the Stratigraphy, Nature and Origin of Near-K-T Breccia

    NASA Astrophysics Data System (ADS)

    Adatte, T.; Keller, G.; Berner, Z.; Stüben, D.

    2007-05-01

    Breccias with altered impact glass and located at or near the K-T boundary in Texas (USA), northern and southern Mexico, Belize, Guatemala, Haiti and Brazil are investigated to determine their age, stratigraphy and origin. Ages are variable. The oldest breccia deposit is within the uppermost Maastrichtian in the southern USA (Brazos, Texas), NE Mexico (e.g., Loma Cerca, El Penon) and in the Chicxulub impact crater cores on Yucatan (e.g., cores Yaxcopoil-1, Y6, C1). In all these sections, the geochemistry of glass within the breccias is identical and consistent with Chicxulub impact ejecta. The K-T boundary, Ir anomaly and mass extinction is located well above these impact breccia layers. This strongly supports a pre-K-T age for the Chicxulub impact, as also determined based on sedimentology, stratigraphy and paleontology. In NE Mexico and Texas the oldest Chicxulub impact spherule ejecta layer is interbedded in normal marine sedimentation in the upper Maastrichtian (base of CF1 Zone), about 300'000 year prior to the K-T boundary. All stratigraphically younger spherule ejecta layers represent repeated episodes of reworking and transport of the original layer during a sea-level regression and re- deposition in incised valleys in shallow environments (e.g., Brazos, Texas, La Popa Basin NE Mexico) and submarine canyons in deeper environments via mass flows and turbidites (e.g. Mimbral, Penon, Loma Cerca and many other section throughout NE Mexico). In southern Mexico, Belize and eastern Guatemala, the widespread thick microspherule and larger spheroid deposits are interbedded with breccia, microbreccias and conglomerates in the early Danian as a result of erosion in shallow carbonate platform sediments. The presence of early Danian planktic foraminifera in the matrix of the breccia, as well as within spherule clasts, indicate that redeposition occurred during the early Danian Parvularugoglobigerina eugubina (P1a) zone. In Haiti (Beloc sections), spherule deposits and

  15. Secondary Particulate Matter Originating from an Industrial Source and Its Impact on Population Health

    PubMed Central

    Mangia, Cristina; Cervino, Marco; Gianicolo, Emilio Antonio Luca

    2015-01-01

    Epidemiological studies have reported adverse associations between long-term exposure to ambient particulate matter (PM2.5) and several health outcomes. One issue in this field is exposure assessment and, in particular, the role of secondary PM2.5, often neglected in environmental and health risk assessment. Thus, the aim of this work was to evaluate the long-term environmental and health impact of primary and secondary PM2.5 concentrations originating from a single industrial source. As a case study, we considered a coal power plant which is a large emitter of both primary PM2.5 and secondary PM2.5 precursors. PM2.5 concentrations were estimated using the Calpuff dispersion model. The health impact was expressed in terms of number of non-accidental deaths potentially attributable to the power plant. Results showed that the estimated secondary PM2.5 extended over a larger area than that related to primary PM2.5 with maximum concentration values of the two components well separated in space. Exposure to secondary PM2.5 increased significantly the estimated number of annual attributable non-accidental deaths. Our study indicates that the impact of secondary PM2.5 may be relevant also at local scale and ought to be considered when estimating the impact of industrial emissions on population health. PMID:26184247

  16. Origin of basaltic soils at Gusev crater, Mars, by aeolian modification of impact-generated sediment

    NASA Astrophysics Data System (ADS)

    McGlynn, Ian O.; Fedo, Christopher M.; McSween, Harry Y., Jr.

    2011-04-01

    Textural properties of soils including grain size, sorting, modality, skewness, shape (quantified as sphericity and qualified as form), roundness, and grain size distribution, have been measured and calculated from Microscopic Imager (MI) high-resolution images from the Mars Exploration Rover (MER) Spirit in Gusev crater. Soil targets were classified by grain size into five groups: fine to medium sand dark soil, medium sand to very fine pebble bed form armor, and very fine to medium pebble lithic fragments, a bimodal mixed soil, and an excavated soil trench. The abundance of submature, very poorly sorted, bimodal mixed soils indicates incomplete sorting by soil type. Probability distributions of excavated subsurface soil match crushed sediment analogs, indicating impact comminution, while all other soils show no direct evidence of an impact origin. If soils were produced primarily by impacts, then the evidence from probability distributions, angular shapes, and agglutinates have been reworked by postimpact surface activity. Soils in Gusev crater are continuously modified, reworked, and sandblasted. Textures of surface sediments are disconnected from subsurface textures and only reflect modern surficial aeolian processes. Models to reconstruct physical and chemical soil formation properties should not assume a static three-dimensional structure. A three-step model, initiated by the formation of basaltic crust and its alteration, followed by bolide impact, and finally modification by aeolian reworking is envisioned for the formation of soils. Such a scenario accounts for the potential that surface sediments may be compositionally and texturally distinct from the subsurface.

  17. The Impact of Political Context on the Questions Asked and Answered: The Evolution of Education Research on Racial Inequality

    ERIC Educational Resources Information Center

    Wells, Amy Stuart; Roda, Allison

    2016-01-01

    This chapter examines how the larger political context and policies enacted at different points in American history have affected the questions education researchers asked and answered. The authors argue that while education researchers are often quick to consider how their research should shape policy, they are less likely to contemplate the…

  18. School Avoidance and Substance Use among Lesbian, Gay, Bisexual, and Questioning Youths: The Impact of Peer Victimization and Adult Support

    ERIC Educational Resources Information Center

    Darwich, Lina; Hymel, Shelley; Waterhouse, Terry

    2012-01-01

    This study examined differences among lesbian, gay, bisexual, and questioning youths in their perceptions of adult support. For socially stigmatized youths, adult support is of particular significance. However, there is very little understanding about how adult support protects youths from homophobic victimization as well as other risk factors. In…

  19. The Interrelations of Features of Questions, Mark Schemes and Examinee Responses and Their Impact upon Marker Agreement

    ERIC Educational Resources Information Center

    Black, Beth; Suto, Irenka; Bramley, Tom

    2011-01-01

    In this paper we develop an evidence-based framework for considering many of the factors affecting marker agreement in GCSEs and A levels. A logical analysis of the demands of the marking task suggests a core grouping comprising: (i) question features; (ii) mark scheme features; and (iii) examinee response features. The framework synthesises…

  20. The Impact of Guided Student-Generated Questioning on Chemistry Achievement and Self-Efficacy of Elementary Preservice Teachers

    ERIC Educational Resources Information Center

    Moseley, Christine; Bonner, Emily; Ibey, Marilyn

    2016-01-01

    This study investigated the use of Guided Student-Generated Questioning (GSGQ) as a metacognitive instructional strategy to increase chemistry achievement and self-efficacy of elementary preservice teachers. The Chemistry Self-Efficacy Scale (CSES), modified from the Biology Self-Efficacy Scale (BSES),was used to determine elementary preservice…

  1. Late Impacts and the Origins of the Atmospheres on the Terrestrial Planets

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, S.; Stewart, S. T.; Lock, S. J.; Parai, R.; Tucker, J. M.

    2014-12-01

    Models for the origin of terrestrial atmospheres typically require an intricate sequence of events, including hydrodynamic escape, outgassing of mantle volatiles and late delivery. Here we discuss the origin of the atmospheres on the terrestrial planets in light of new ideas about the formation of the Moon, giant impact induced atmospheric loss and recent noble gas measurements. Our new measurements indicate that noble gases in the Earth's atmosphere cannot be derived from any combination of fractionation of a nebular-derived atmosphere followed by outgassing of deep or shallow mantle volatiles. While Ne in the mantle retains a nebular component, the present-day atmosphere has no memory of nebular gases. Rather, atmospheric noble gases have a close affinity to chondrites. On the other hand, Venus's atmosphere has 20 and 70 times higher abundance of 20Ne and 36Ar, respectively, and a 20Ne/22Ne ratio closer to the solar value than Earth's atmosphere. While the present atmosphere of Mars is significantly fractionated in the lighter noble gases due to long term atmospheric escape, the Kr isotopic ratios in Martian atmosphere are identical to solar. Thus, while Earth's atmosphere has no memory of accretion of nebular gases, atmospheres on both Venus and Mars preserve at least a component of nebular gases. To explain the above observations, we propose that a common set of processes operated on the terrestrial planets, and that their subsequent evolutionary divergence is simply explained by planetary size and the stochastic nature of giant impacts. We present geochemical observations and simulations of giant impacts to show that most of Earth's mantle was degassed and the outgassed volatiles were largely lost during the final sequence of giant impacts onto Earth. Earth's noble gases were therefore dominantly derived from late-accreting planetesimals. In contrast, Venus did not suffer substantial atmospheric loss by a late giant impact and retains a higher abundance of

  2. Shared origin for seven of Mars Trojans - impact ejecta from Mars?

    NASA Astrophysics Data System (ADS)

    Polishook, David; Jacobson, Seth A.; Aharonson, Oded

    2016-10-01

    Seven out of nine Mars Trojans belong to an orbital grouping that started to spread about 109 years ago (Cuk et al. 2015). We spectrally observed two of them (311999 and 385250) using the IRTF telescope and found that both present an identical olivine-rich reflectance spectrum, that is similar to the reflectance spectrum of (5261) Eureka, the largest of these seven Trojans (Rivkin et al. 2007). These measurements confirm the shared origin of the seven. Moreover, olivine-rich reflectance spectra is rare within asteroids, but is visible in numerous locations on Mars and is found within SNC meteorites that are argued to originate from Mars (Chassigny, ALHA77005; McSween 1985). This spectral resemblance encourages us to suggest that the seven Trojans are impact ejecta from Mars' plutonic rock. We will present dynamical calculations showing how the impact ejecta could have been caught in L5 and that there are enough size-relevant craters on Mars surface to produce these seven Trojans.

  3. The Calvin 28 cryptoexplosive disturbance, Cass County, Michigan: Evidence for impact origin

    NASA Technical Reports Server (NTRS)

    Milstein, Randall L.

    1988-01-01

    The Calvin 28 cryptoexplosive disturbance is an isolated, nearly circular subsurface structure of Late Ordovician age in southwestern Michigan. The structure is defined by 107 wells, is about 7.24 km in diameter and consists of a central dome, an annular depression and an encircling anticlinal rim. Seismic and geophysical well log data confirm that an intricate system of faults and structural derangement exists within the structure. Deformation decreases with depth and distance from the structure. U.S.G.S. topographic maps and aerial imagery show the structure is reflected as a subtle surface topographic rise controlling local drainage. Igneous or diapiric intrusion and solution collapse are rejected as possible origins for Calvin 28 on the basis of stratigraphic, structural and geophysical evidence. A volcanic origin is inconsistent with calculated energy requirements and an absence of igneous material. Although shock-metamorphic features are unidentified, microbreccias occur in deep wells that penetrate the structure. Morphology and structural parameters support an impact origin.

  4. Panspermia asks new questions

    NASA Astrophysics Data System (ADS)

    Klyce, Brig

    2001-08-01

    There is a widespread sentiment that panspermia is uninteresting is because it does not answer fundamental questions about the origin of life. The strongest version of panspermia asks entirely new questions. While barriers to the acceptance of panspermia are falling and evidence supporting it is accumulating, the mere possibility of panspermia unhinges the Darwinian account of evolutionary progress. The new theory removes an issue dividing science and religion, but it requires an amendment to the big bang theory.

  5. Possible mantle origin of olivine around lunar impact basins detected by SELENE

    NASA Astrophysics Data System (ADS)

    Yamamoto, Satoru; Nakamura, Ryosuke; Matsunaga, Tsuneo; Ogawa, Yoshiko; Ishihara, Yoshiaki; Morota, Tomokatsu; Hirata, Naru; Ohtake, Makiko; Hiroi, Takahiro; Yokota, Yasuhiro; Haruyama, Junichi

    2010-08-01

    The composition, structure and evolution of the Moon's mantle is poorly constrained. The mineral olivine, one of the main constituents of Earth's mantle, has been identified by Earth-based telescopic observations at two craters on the near side of the Moon, Aristarchus and Copernicus. Global reflectance spectra in five discrete spectral bands produced by the spacecraft Clementine suggested several possible olivine-bearing sites, but one of the candidate occurrences of olivine was later re-classified, on the basis of continuous reflectance spectra over the entire 1μm band, as a mixture of plagioclase and pyroxene. Here we present a global survey of the lunar surface using the Spectral Profiler onboard the lunar explorer SELENE/Kaguya. We found many exposures of olivine on the Moon, located in concentric regions around the South Pole-Aitken, Imbrium and Moscoviense impact basins where the crust is relatively thin. We propose that these exposures of olivine can be attributed either to an excavation of the lunar mantle at the time of the impacts that formed the basins, or to magnesium-rich pluton in the Moon's lower crust. On the basis of radiative transfer modelling, we suggest that at least some of the olivine detected near impact basins originates from upper mantle of the Moon.

  6. The impact of history on our perception of evolutionary events: endosymbiosis and the origin of eukaryotic complexity.

    PubMed

    Keeling, Patrick J

    2014-02-01

    Evolutionary hypotheses are correctly interpreted as products of the data they set out to explain, but they are less often recognized as being heavily influenced by other factors. One of these is the history of preceding thought, and here I look back on historically important changes in our thinking about the role of endosymbiosis in the origin of eukaryotic cells. Specifically, the modern emphasis on endosymbiotic explanations for numerous eukaryotic features, including the cell itself (the so-called chimeric hypotheses), can be seen not only as resulting from the advent of molecular and genomic data, but also from the intellectual acceptance of the endosymbiotic origin of mitochondria and plastids. This transformative idea may have unduly affected how other aspects of the eukaryotic cell are explained, in effect priming us to accept endosymbiotic explanations for endogenous processes. Molecular and genomic data, which were originally harnessed to answer questions about cell evolution, now so dominate our thinking that they largely define the question, and the original questions about how eukaryotic cellular architecture evolved have been neglected. This is unfortunate because, as Roger Stanier pointed out, these cellular changes represent life's "greatest single evolutionary discontinuity," and on this basis I advocate a return to emphasizing evolutionary cell biology when thinking about the origin of eukaryotes, and suggest that endogenous explanations will prevail when we refocus on the evolution of the cell.

  7. The Impact of History on Our Perception of Evolutionary Events: Endosymbiosis and the Origin of Eukaryotic Complexity

    PubMed Central

    Keeling, Patrick J.

    2014-01-01

    Evolutionary hypotheses are correctly interpreted as products of the data they set out to explain, but they are less often recognized as being heavily influenced by other factors. One of these is the history of preceding thought, and here I look back on historically important changes in our thinking about the role of endosymbiosis in the origin of eukaryotic cells. Specifically, the modern emphasis on endosymbiotic explanations for numerous eukaryotic features, including the cell itself (the so-called chimeric hypotheses), can be seen not only as resulting from the advent of molecular and genomic data, but also from the intellectual acceptance of the endosymbiotic origin of mitochondria and plastids. This transformative idea may have unduly affected how other aspects of the eukaryotic cell are explained, in effect priming us to accept endosymbiotic explanations for endogenous processes. Molecular and genomic data, which were originally harnessed to answer questions about cell evolution, now so dominate our thinking that they largely define the question, and the original questions about how eukaryotic cellular architecture evolved have been neglected. This is unfortunate because, as Roger Stanier pointed out, these cellular changes represent life’s “greatest single evolutionary discontinuity,” and on this basis I advocate a return to emphasizing evolutionary cell biology when thinking about the origin of eukaryotes, and suggest that endogenous explanations will prevail when we refocus on the evolution of the cell. PMID:24492708

  8. Questionable Exercises.

    ERIC Educational Resources Information Center

    Liemohn, Wendell; Haydu, Traci; Phillips, Dawn

    1999-01-01

    This publication presents general guidelines for exercise prescription that have an anatomical basis but also consider the exerciser's ability to do the exercise correctly. It reviews various common questionable exercises, explaining how some exercises, especially those designed for flexibility and muscle fitness, can cause harm. Safer…

  9. Questor's Question

    ERIC Educational Resources Information Center

    Erickson, Mary; Dock, Michelle Nichols; Eldridge, Laurie

    2009-01-01

    Questor is a curious little bird whose four broad questions are helpful to anyone interested in making art or understanding the art of others. He was designed as a character in an online video for children, "Building on a River: Questor's Tale." The video is narrated by Questor, who relates the 2000 year history of architecture along the Salt…

  10. "The" Question.

    ERIC Educational Resources Information Center

    Lowe, Pardee, Jr.

    1984-01-01

    Examines the suggestions found in Michael Canale's paper, "Considerations in the Testing of Reading and Listening Proficiency," in the light of a possible U.S. Government's Interagency Language Roundtable receptive skills proficiency test which must supply the answer to the question of how well an individual can understand a particular…

  11. Critical Questions.

    ERIC Educational Resources Information Center

    Worthy, Jo; Hoffman, James V.

    1998-01-01

    Offers responses from four readers of this journal, all reading and/or classroom teachers, to a question posed by another teacher: whether children who have had limited literacy experiences should start reading in whole-language readers and/or trade books or whether they should start in controlled-vocabulary preprimers. (SR)

  12. Four Questions

    ERIC Educational Resources Information Center

    Hark-Weber, Amara G., Ed.

    2013-01-01

    Teaching artists often find themselves working in schools and communities that are new to them, whether these are situations close to home or farther afield. This issue of Four Questions highlights teaching artists who travel extensively as part of their teaching and artistic practices and bring their expertise, energy, and creativity to…

  13. The cratering record at Uranus: Implications for satellite evolution and the origin of impacting objects

    NASA Technical Reports Server (NTRS)

    Strom, Robert G.

    1987-01-01

    The crater size/frequency distributions on the major Uranian satellites show two distinctly different crater populations of different ages. Any hypothesis on the origin of the objects responsible for the period of heavy bombardment must account for the occurrence of different crater populations (size/frequency distributions) in different parts of the solar system. A computerized simulation using short-period comet impact velocities and a modified Holsapple-Schmidt crater scaling law was used to recover the size distribution of cometary nuclei from the observed cratering record. The most likely explanation for the cratering record is that the period of heavy bombardment was caused by different families of accretional remnants indigenous to the system in which the different crater populations occurred.

  14. Geochemistry of polymict ureilite EET83309, and a partially-disruptive impact model for ureilite origin

    NASA Technical Reports Server (NTRS)

    Warren, Paul H.; Kallemeyn, Gregory W.

    1989-01-01

    Bulk-compositional data for the EET83309 polymict ureilite were obtained using INAA and radiochemistry procedures and electron probe analysis. It was found that the EET83309 has a bulk composition indistinguishable from ordinary ('monomict') ureilites for all elements except light-middle REEs (which are present in much higher concentrations), suggesting that polymict ureilites are mixtures of ordinary ureilites which were mixed on a very small number of parent bodies. Despite the light-REE enrichments, polymict ureilites are nearly devoid of basaltic (Al-rich) material. It is suggested that the missing basalt may have been blown off the parent body by a partially disruptive collision with a large C-rich projectile. This impact model of ureilite origin reconciles many paradoxical aspects of ureilite composition.

  15. Origin and diagenesis of K/T impact spherules - from Haiti to Wyoming and beyond

    USGS Publications Warehouse

    Bohor, B.F.; Glass, B.P.

    1995-01-01

    Impact spherules in Cretaceous/Tertiary (K/T) boundary clays and claystones consist of two types; each type is confined to its own separate layer of the boundary couplet in the Western Hemisphere. The form and composition of each of the spherule types result from its own unique mode of origin during the K/T event. Type 1 splash-form spherules occur only in the melt-ejecta (basal) layer of the K/T couplet. This layer was deposited from a ballistic ejecta curtain composed of melt-glass droplets transported mostly within the atmosphere. In contrast, Type 2 spherules are accreted, partially crystalline, spheroidal bodies that formed by condensation of vaporized bolide and target-rock materials in an expanding fireball cloud, from which they settled out of buoyant suspension to form the fireball layer. Dendritic and skeletal Ni-rich spinel crystals are unique to these Type 2 spherules in the fireball layer. -from Authors

  16. An investigation into the impact of question structure on the performance of first year physics undergraduate students at the University of Cambridge

    NASA Astrophysics Data System (ADS)

    Gibson, Valerie; Jardine-Wright, Lisa; Bateman, Elizabeth

    2015-07-01

    We describe a study of the impact of exam question structure on the performance of first year Natural Sciences physics undergraduates from the University of Cambridge. The results show conclusively that a student’s performance improves when questions are scaffolded compared with university style questions. In a group of 77 female students we observe that the average exam mark increases by 13.4% for scaffolded questions, which corresponds to a 4.9 standard deviation effect. The equivalent observation for 236 male students is 9% (5.5 standard deviations). We also observe a correlation between exam performance and A2-level marks for UK students, and that students who receive their school education overseas, in a mixed gender environment, or at an independent school are more likely to receive a first class mark in the exam. These results suggest a mis-match between the problem-solving skills and assessment procedures between school and first year university and will provide key input into the future teaching and assessment of first year undergraduate physics students.

  17. Potassium isotopic evidence for a high-energy giant impact origin of the Moon.

    PubMed

    Wang, Kun; Jacobsen, Stein B

    2016-10-27

    The Earth-Moon system has unique chemical and isotopic signatures compared with other planetary bodies; any successful model for the origin of this system therefore has to satisfy these chemical and isotopic constraints. The Moon is substantially depleted in volatile elements such as potassium compared with the Earth and the bulk solar composition, and it has long been thought to be the result of a catastrophic Moon-forming giant impact event. Volatile-element-depleted bodies such as the Moon were expected to be enriched in heavy potassium isotopes during the loss of volatiles; however such enrichment was never found. Here we report new high-precision potassium isotope data for the Earth, the Moon and chondritic meteorites. We found that the lunar rocks are significantly (>2σ) enriched in the heavy isotopes of potassium compared to the Earth and chondrites (by around 0.4 parts per thousand). The enrichment of the heavy isotope of potassium in lunar rocks compared with those of the Earth and chondrites can be best explained as the result of the incomplete condensation of a bulk silicate Earth vapour at an ambient pressure that is higher than 10 bar. We used these coupled constraints of the chemical loss and isotopic fractionation of K to compare two recent dynamic models that were used to explain the identical non-mass-dependent isotope composition of the Earth and the Moon. Our K isotope result is inconsistent with the low-energy disk equilibration model, but supports the high-energy, high-angular-momentum giant impact model for the origin of the Moon. High-precision potassium isotope data can also be used as a 'palaeo-barometer' to reveal the physical conditions during the Moon-forming event.

  18. Potassium isotopic evidence for a high-energy giant impact origin of the Moon

    NASA Astrophysics Data System (ADS)

    Wang, Kun; Jacobsen, Stein B.

    2016-10-01

    The Earth-Moon system has unique chemical and isotopic signatures compared with other planetary bodies; any successful model for the origin of this system therefore has to satisfy these chemical and isotopic constraints. The Moon is substantially depleted in volatile elements such as potassium compared with the Earth and the bulk solar composition, and it has long been thought to be the result of a catastrophic Moon-forming giant impact event. Volatile-element-depleted bodies such as the Moon were expected to be enriched in heavy potassium isotopes during the loss of volatiles; however such enrichment was never found. Here we report new high-precision potassium isotope data for the Earth, the Moon and chondritic meteorites. We found that the lunar rocks are significantly (>2σ) enriched in the heavy isotopes of potassium compared to the Earth and chondrites (by around 0.4 parts per thousand). The enrichment of the heavy isotope of potassium in lunar rocks compared with those of the Earth and chondrites can be best explained as the result of the incomplete condensation of a bulk silicate Earth vapour at an ambient pressure that is higher than 10 bar. We used these coupled constraints of the chemical loss and isotopic fractionation of K to compare two recent dynamic models that were used to explain the identical non-mass-dependent isotope composition of the Earth and the Moon. Our K isotope result is inconsistent with the low-energy disk equilibration model, but supports the high-energy, high-angular-momentum giant impact model for the origin of the Moon. High-precision potassium isotope data can also be used as a ‘palaeo-barometer’ to reveal the physical conditions during the Moon-forming event.

  19. A giant impact origin for Pluto's small moons and satellite multiplicity in the Kuiper belt.

    PubMed

    Stern, S A; Weaver, H A; Steffl, A J; Mutchler, M J; Merline, W J; Buie, M W; Young, E F; Young, L A; Spencer, J R

    2006-02-23

    The two newly discovered satellites of Pluto (P1 and P2) have masses that are small compared to both Pluto and Charon-that is, between 5 x 10(-4) and 1 x 10(-5) of Pluto's mass, and between 5 x 10(-3) and 1 x 10(-4) of Charon's mass. This discovery, combined with the constraints on the absence of more distant satellites of Pluto, reveal that Pluto and its moons comprise an unusual, highly compact, quadruple system. These facts naturally raise the question of how this puzzling satellite system came to be. Here we show that P1 and P2's proximity to Pluto and Charon, the fact that P1 and P2 are on near-circular orbits in the same plane as Pluto's large satellite Charon, along with their apparent locations in or near high-order mean-motion resonances, all probably result from their being constructed from collisional ejecta that originated from the Pluto-Charon formation event. We also argue that dust-ice rings of variable optical depths form sporadically in the Pluto system, and that rich satellite systems may be found--perhaps frequently--around other large Kuiper belt objects.

  20. PSD Questions

    EPA Pesticide Factsheets

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  1. Domestication and early agriculture in the Mediterranean Basin: Origins, diffusion, and impact

    PubMed Central

    Zeder, Melinda A.

    2008-01-01

    The past decade has witnessed a quantum leap in our understanding of the origins, diffusion, and impact of early agriculture in the Mediterranean Basin. In large measure these advances are attributable to new methods for documenting domestication in plants and animals. The initial steps toward plant and animal domestication in the Eastern Mediterranean can now be pushed back to the 12th millennium cal B.P. Evidence for herd management and crop cultivation appears at least 1,000 years earlier than the morphological changes traditionally used to document domestication. Different species seem to have been domesticated in different parts of the Fertile Crescent, with genetic analyses detecting multiple domestic lineages for each species. Recent evidence suggests that the expansion of domesticates and agricultural economies across the Mediterranean was accomplished by several waves of seafaring colonists who established coastal farming enclaves around the Mediterranean Basin. This process also involved the adoption of domesticates and domestic technologies by indigenous populations and the local domestication of some endemic species. Human environmental impacts are seen in the complete replacement of endemic island faunas by imported mainland fauna and in today's anthropogenic, but threatened, Mediterranean landscapes where sustainable agricultural practices have helped maintain high biodiversity since the Neolithic. PMID:18697943

  2. The Impact of 3-Option Responses to Multiple-Choice Questions on Guessing Strategies and Cut Score Determinations

    PubMed Central

    ROYAL, KENNETH D.; STOCKDALE, MYRAH R.

    2017-01-01

    Introduction: Research has asserted MCQ items using three response options (one correct answer with two distractors) is comparable to, and possibly preferable over, traditional MCQ item formats consisting of four response options (e.g., one correct answer with three distractors), or five response options (e.g., one correct answer with four distractors). Some medical educators have also adopted the practice of using 3-option responses on MCQ exams as a response to the difficulty experienced in generating additional plausible distractors. To date, however, little work has explored how 3-option responses might impact validity threats stemming from random guessing strategies, and what impact 3-option responses might have on cut-score determinations, particularly in the context of medical education classroom assessments. The purpose of this work is to further explore these critically important considerations that largely have gone ignored in the medical education literature to this point. Methods: A cumulative binomial distribution formula was used to calculate the probability that an examinee will answer at random a given number of items correctly on any exam (of any length). By way of a demonstration, a variety of scenarios were presented to illustrate how examination length and the number of response options impact examinees’ chances of passing a given examination, and how subsequent cut-score decisions may be impacted by these factors. Results: As a general rule, classroom assessments containing fewer items should utilize traditional 4-option or 5-option responses, whereas assessments of greater length are afforded greater flexibility in potentially utilizing 3-option responses. Conclusions: More research on items with 3-option responses is needed to better understand what value, if any, 3-option responses truly add to classroom assessments, and in what contexts potential benefits might be discernible. PMID:28367465

  3. A symbiotic view of the origin of life at hydrothermal impact crater-lakes.

    PubMed

    Chatterjee, Sankar

    2016-07-27

    Submarine hydrothermal vents are generally considered as the likely habitats for the origin and evolution of early life on Earth. The theory suffers from the 'concentration problem' of cosmic and terrestrial biomolecules because of the vastness of the Eoarchean global ocean. An attractive alternative site would be highly sequestered, small, hydrothermal crater-lakes that might have cradled life on early Earth. A new symbiotic model for the origin of life at hydrothermal crater-lakes is proposed here. Meteoritic impacts on the Eoarchean crust at the tail end of the Heavy Bombardment period might have played important roles in the origin of life. Impacts and collisions that created hydrothermal crater lakes on the Eoarchean crust inadvertently became the perfect crucibles for prebiotic chemistry with building blocks of life, which ultimately led to the first organisms by prebiotic synthesis. In this scenario, life arose through four hierarchical stages of increasing molecular complexity in multiple niches of crater basins. In the cosmic stage (≥4.6 Ga), the building blocks of life had their beginnings in the interstellar space during the explosion of a nearby star. Both comets and carbonaceous chondrites delivered building blocks of life and ice to early Earth, which were accumulated in hydrothermal impact crater-lakes. In the geologic stage (∼4 Ga), crater basins contained an assortment of cosmic and terrestrial organic compounds, powered by hydrothermal, solar, tidal, and chemical energies, which drove the prebiotic synthesis. At the water surface, self-assembled primitive lipid membranes floated as a thick oil slick. Archean Greenstone belts in Greenland, Australia, and South Africa possibly represent the relics of these Archean craters, where the oldest fossils of thermophilic life (∼3.5 Ga) have been detected. In the chemical stage, monomers such as nucleotides and amino acids were selected from random assemblies of the prebiotic soup; they were

  4. Does Plant Origin Influence the Fitness Impact of Flower Damage? A Meta-Analysis

    PubMed Central

    González-Browne, Catalina; Murúa, Maureen M.; Navarro, Luis; Medel, Rodrigo

    2016-01-01

    Herbivory has been long considered an important component of plant-animal interactions that influences the success of invasive species in novel habitats. One of the most important hypotheses linking herbivory and invasion processes is the enemy-release hypothesis, in which exotic plants are hypothesized to suffer less herbivory and fitness-costs in their novel ranges as they leave behind their enemies in the original range. Most evidence, however, comes from studies on leaf herbivory, and the importance of flower herbivory for the invasion process remains largely unknown. Here we present the results of a meta-analysis of the impact of flower herbivory on plant reproductive success, using as moderators the type of damage caused by floral herbivores and the residence status of the plant species. We found 51 papers that fulfilled our criteria. We also included 60 records from unpublished data of the laboratory, gathering a total of 143 case studies. The effects of florivory and nectar robbing were both negative on plant fitness. The methodology employed in studies of flower herbivory influenced substantially the outcome of flower damage. Experiments using natural herbivory imposed a higher fitness cost than simulated herbivory, such as clipping and petal removal, indicating that studies using artificial herbivory as surrogates of natural herbivory underestimate the real fitness impact of flower herbivory. Although the fitness cost of floral herbivory was high both in native and exotic plant species, floral herbivores had a three-fold stronger fitness impact on exotic than native plants, contravening a critical element of the enemy-release hypothesis. Our results suggest a critical but largely unrecognized role of floral herbivores in preventing the spread of introduced species into newly colonized areas. PMID:26785039

  5. Assessing the impact of de novo social ties within health intervention settings: New questions for health behavior intervention research

    PubMed Central

    Tesdahl, Eric; Gesell, Sabina B.

    2015-01-01

    Recent developments in the study of health and social networks have focused on linkages between health outcomes and naturally-occurring social relations, such as friendship or kinship. Based on findings in this area, a new generation of health behavior intervention programs have been implemented that rely on the formation of new social relations among program participants. However, little is known about the qualities of these de novo social relations. We examined the social networks of 59 participants within a randomized controlled trial of an intervention designed to prevent excessive gestational weight gain. We employed exponential random graph modeling techniques to analyze supportive relationships formed between participants in the intervention arm, to detect unique effects of program participation on the likelihood of forming ties. Program participation had a positive effect on the likelihood of forming supportive social relations, however, in this particular timeframe we did not detect any additional effect of such relations on the health behaviors or outcomes of interest. Our findings raise two critical questions: do short-term group-level programs reliably lead to the formation of new social relations among participants; and do these relations have a unique effect on health outcomes relative to standard methods of health behavior intervention? PMID:26577514

  6. Assessing the Impact of De Novo Social Ties within Health Intervention Settings: New Questions for Health Behavior Intervention Research.

    PubMed

    Tesdahl, Eric; Gesell, Sabina B

    2015-12-01

    Recent developments in the study of health and social networks have focused on linkages between health outcomes and naturally occurring social relations, such as friendship or kinship. Based on findings in this area, a new generation of health behavior intervention programs have been implemented that rely on the formation of new social relations among program participants. However, little is known about the qualities of these de novo social relations. We examined the social networks of 59 participants within a randomized controlled trial of an intervention designed to prevent excessive gestational weight gain. We employed exponential random graph modeling techniques to analyze supportive relationships formed between participants in the intervention arm, to detect unique effects of program participation on the likelihood of forming ties. Program participation had a positive effect on the likelihood of forming supportive social relations, however, in this particular timeframe we did not detect any additional effect of such relations on the health behaviors or outcomes of interest. Our findings raise two critical questions: do short-term group-level programs reliably lead to the formation of new social relations among participants; and do these relations have a unique effect on health outcomes relative to standard methods of health behavior intervention?

  7. On the origin of superparamagnetic minerals of tropical soils and their impact on landmine detection

    NASA Astrophysics Data System (ADS)

    Igel, Jan; Preetz, Holger; Altfelder, Sven

    2010-05-01

    Magnetic susceptibility of soils is mainly determined by their content of ferrimagnetic minerals whereas titanomagnetite, magnetite and maghemite being the most important ones. Titanomagnetite and magnetite are of magmatic origin, i.e. they crystallise during cooling of iron-rich magma and are part of many igneous rocks. Maghemite and sometimes magnetite are of pedogenic origin. They develop by crystallisation of dissolved iron during soil forming processes. Ferrimagnetic minerals that are smaller than some tens of nanometres are superparamagnetic (SP) and show frequency dependent susceptibility. SP minerals crystallise if magma cools down rapidly (e.g. volcanic magmas, glasses and ashes) and are frequently formed during pedogenesis. In order to investigate the origin and formation of SP minerals in tropical soils, we analyse magnetic properties of 594 samples from the entire tropics comprising the whole range of weathering states from unweathered rock to highly weathered soil. Tropical soils are subject to intense chemical weathering and are rich in ferrimagnetic and in particular SP minerals. The process leading to a high content of these minerals is either residual enrichment due to their weathering resistance or neo-formation. In this study we focus on the frequency dependent susceptibility (absolute and relative) of the samples and classify it according to the parent material and alteration. We observe that • within each parent-material group, rock material shows in general lower susceptibility and absolute frequency dependence than soil material • ultrabasic and basic/intermediate rocks and soils developed from these rocks show high absolute frequency dependent susceptibility and, in contrast, acid rocks and sediments show lower absolute frequency dependence • absolute frequency dependence increases from unweathered rock to weathered rock, and from subsoil to topsoil material within every group of parent material • relative frequency dependence rises

  8. False alarms and missed events: the impact and origins of perceived inaccuracy in tornado warning systems.

    PubMed

    Ripberger, Joseph T; Silva, Carol L; Jenkins-Smith, Hank C; Carlson, Deven E; James, Mark; Herron, Kerry G

    2015-01-01

    Theory and conventional wisdom suggest that errors undermine the credibility of tornado warning systems and thus decrease the probability that individuals will comply (i.e., engage in protective action) when future warnings are issued. Unfortunately, empirical research on the influence of warning system accuracy on public responses to tornado warnings is incomplete and inconclusive. This study adds to existing research by analyzing two sets of relationships. First, we assess the relationship between perceptions of accuracy, credibility, and warning response. Using data collected via a large regional survey, we find that trust in the National Weather Service (NWS; the agency responsible for issuing tornado warnings) increases the likelihood that an individual will opt for protective action when responding to a hypothetical warning. More importantly, we find that subjective perceptions of warning system accuracy are, as theory suggests, systematically related to trust in the NWS and (by extension) stated responses to future warnings. The second half of the study matches survey data against NWS warning and event archives to investigate a critical follow-up question--Why do some people perceive that their warning system is accurate, whereas others perceive that their system is error prone? We find that subjective perceptions are--in part-a function of objective experience, knowledge, and demographic characteristics. When considered in tandem, these findings support the proposition that errors influence perceptions about the accuracy of warning systems, which in turn impact the credibility that people assign to information provided by systems and, ultimately, public decisions about how to respond when warnings are issued.

  9. Tektite origin by hypervelocity asteroidal or cometary impact: The quest for the source craters

    NASA Technical Reports Server (NTRS)

    Koeberl, Christian

    1992-01-01

    Tektites are natural glasses that are chemically homogeneous, often spherically symmetrical objects several centimeters in size, and occur in four known strewn fields on the surface of the Earth: the North American, moldavite (or Central European), Ivory Coast, and Australasian strewn fields. Tektites found within such strewn fields are related to each other with respect to their petrological, physical, and chemical properties as well as their age. A theory of tektite origin needs to explain the similarity of tektites in respect to age and certain aspects of isotopic and chemical composition within one strewn field, as well as the variety of tektite materials present in each strewn field. In addition to tektites on land, microtektites (which are generally less than 1 mm in diameter) have been found in deep-sea cores. Tektites are classified into three groups: (1) normal or splash-form tektites, (2) aerodynamically shaped tektites, and (3) Muong Nong-type tektites (sometimes also called layered tektites). The aerodynamic ablation results from partial remelting of glass during atmospheric passage after it was ejected outside the terrestrial atmosphere and quenched from a hot liquid. Aerodynamically shaped tektites are known mainly from the Australasian strewn field where they occur as flanged-button australites. The shapes of splash-form tektites (spheres, droplets, teardrops, dumbbells, etc., or fragments thereof) are the result of the solidification of rotating liquids in the air or vacuum. Mainly due to chemical studies, it is now commonly accepted that tektites are the product of melting and quenching of terrestrial rocks during hypervelocity impact on the Earth. The chemistry of tektites is in many respects identical to the composition of upper crustal material.

  10. Mercurian volcanism questioned

    USGS Publications Warehouse

    Wilhelms, D.E.

    1976-01-01

    The Mariner 10 television team has argued that extensive plains on Mercury were formed by volcanism and compared them with the demonstrably lunar maria. I believe, however, that in stratigraphic relations, surface morphology, and albedo contrast, the Mercurian plains more closely resemble the lunar light plains. These lunar plains were interpreted as volcanic on the basis of data comparable to that available to the Mariner 10 investigators but have been shown by the Apollo missions to be of impact origin. The plains on Mercury might also be formed of impact materials, perhaps of impact melt or other basin ejecta that behaved more like a fluid when emplaced that did lunar basin ejecta. ?? 1976.

  11. The Impact of Origin and Host Country Schooling on the Economic Performance of Immigrants

    ERIC Educational Resources Information Center

    Kanas, Agnieszka; van Tubergen, Frank

    2009-01-01

    This study examines the economic returns to schooling acquired in the country of origin and the country of destination. It uses large-scale survey data on Turkish, Moroccan, Surinamese and Antillean immigrants in the Netherlands, which contain direct measures of pre- and post migration schooling. It is studied whether the returns to origin-country…

  12. A decadal satellite analysis of the origins and impacts of smoke in Colorado

    NASA Astrophysics Data System (ADS)

    Martin, M. Val; Heald, C. L.; Ford, B.; Prenni, A. J.; Wiedinmyer, C.

    2013-03-01

    We analyze the record of aerosol optical depth (AOD) measured by the MODerate resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite in combination with surface PM2.5 to investigate the impact of fires on aerosol loading and air quality over Colorado from 2000 to 2012, and to evaluate the contribution of local versus transported smoke. Fire smoke contributed significantly to the AOD levels observed over Colorado. During the worst fire seasons of 2002 and 2012, average MODIS AOD over the Colorado Front Range corridor were 20-50% larger than the other 11 yr studied. Surface PM2.5 was also unusually elevated during fire events and concentrations were in many occasions above the daily National Ambient Air Quality Standard (35 μg m-3) and even reached locally unhealthy levels (> 100 μg m-3) over populated areas during the 2012 High Park fire and the 2002 Hayman fire. Over the 13 yr examined, long-range transport of smoke from northwestern US and even California (>1500 km distance) occurred often and affected AOD and surface PM2.5. During most of the transport events, MODIS AOD and surface PM2.5 were reasonable correlated (r2 = 0.2-0.9), indicating that smoke subsided into the Colorado boundary layer and reached surface levels. However, that is not always the case since at least one event of AOD enhancement was disconnected from the surface (r2<0.01 and low PM2.5 levels). Observed plume heights from the Multi-angle Imaging SpectroRadiometer (MISR) satellite instrument and vertical aerosol profiles measured by the space-based Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) showed a complex vertical distribution of smoke emitted by the High Park fire in 2012. Smoke was detected from a range of 1.5 to 7.5 km altitude at the fire origin and from ground levels to 12.3 km altitude far away from the source. The variability of smoke altitude as well as the local meteorology were key in determining the aerosol loading and air quality over the Colorado

  13. A decadal satellite analysis of the origins and impacts of smoke in Colorado

    NASA Astrophysics Data System (ADS)

    Martin, M. Val; Heald, C. L.; Ford, B.; Prenni, A. J.; Wiedinmyer, C.

    2013-08-01

    We analyze the record of aerosol optical depth (AOD) measured by the MODerate resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite in combination with surface PM2.5 to investigate the impact of fires on aerosol loading and air quality over Colorado from 2000 to 2012, and to evaluate the contribution of local versus transported smoke. Fire smoke contributed significantly to the AOD levels observed over Colorado. During the worst fire seasons of 2002 and 2012, average MODIS AOD over the Colorado Front Range corridor were 20-50% larger than the other 11 yr studied. Surface PM2.5 was also unusually elevated during fire events and concentrations were in many occasions above the daily National Ambient Air Quality Standard (35 μg m-3) and even reached locally unhealthy levels (> 100 μg m-3) over populated areas during the 2012 High Park fire and the 2002 Hayman fire. Over the 13 yr examined, long-range transport of smoke from northwestern US and even California (> 1500 km distance) occurred often and affected AOD and surface PM2.5. During most of the transport events, MODIS AOD and surface PM2.5 were reasonable correlated (r2 = 0.2-0.9), indicating that smoke subsided into the Colorado boundary layer and reached surface levels. However, that is not always the case since at least one event of AOD enhancement was disconnected from the surface (r2<0.01 and low PM2.5 levels). Observed plume heights from the Multi-angle Imaging SpectroRadiometer (MISR) satellite instrument and vertical aerosol profiles measured by the space-based Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) showed a complex vertical distribution of smoke emitted by the High Park fire in 2012. Smoke was detected from a range of 1.5 to 7.5 km altitude at the fire origin and from ground levels to 12.3 km altitude far away from the source. The variability of smoke altitude as well as the local meteorology were key in determining the aerosol loading and air quality over the

  14. Impact of Roasting on Identification of Hazelnut (Corylus avellana L.) Origin: A Chemometric Approach.

    PubMed

    Locatelli, Monica; Coïsson, Jean Daniel; Travaglia, Fabiano; Bordiga, Matteo; Arlorio, Marco

    2015-08-19

    Hazelnuts belonging to different cultivars or cultivated in different geographic areas can be differentiated by their chemical profile; however, the roasting process may affect the composition of raw hazelnuts, thus compromising the possibility to identify their origin in processed foods. In this work, we characterized raw and roasted hazelnuts (Tonda Gentile Trilobata, TGT, from Italy and from Chile, Tonda di Giffoni from Italy, and Tombul from Turkey), as well as hazelnuts isolated from commercial products, with the aim to discriminate their cultivar and origin. The chemometric evaluation of selected chemical parameters (proximate composition, fatty acids, total polyphenols, antioxidant activity, and protein fingerprint by SDS-PAGE) permitted us to identify hazelnuts belonging to different cultivars and, concerning TGT samples, their different geographic origin. Also commercial samples containing Piedmontese TGT hazelnuts were correctly assigned to TGT cluster. In conclusion, even if the roasting process modifies the composition of roasted hazelnuts, this preliminary model study suggests that the identification of their origin is still possible.

  15. Endogenous production, exogenous delivery and impact-shock synthesis of organic molecules - An inventory for the origins of life

    NASA Technical Reports Server (NTRS)

    Chyba, Christopher; Sagan, Carl

    1992-01-01

    The contribution of organic-rich comets, carbonaceous asteroids, and interplanetary dust particles and of impact shock-synthesized organics in the atmosphere to the origin of life on earth is studied and quantitatively compared with the principal non-heavy-bombardment sources of prebiotic organics. The results suggest that heavy bombardment before 3.5 Gyr ago either produced or delivered quantities of organics comparable to those produced by other energy sources.

  16. Nd-isotopic evidence for the origin of the Sudbury complex by meteoritic impact

    NASA Technical Reports Server (NTRS)

    Faggart, B. E.; Basu, A. R.; Tatsumoto, M.

    1985-01-01

    A Neodymium isotopic investigation was undertaken in order to determine the possibility that the Sudbury geological structure in Ontario, Canada was formed by meteoritic impact. Conclusive evidence points to the melting of crustal rocks by way of meteoritic impact in the forming of the Sudbury structure.

  17. Atmosphere-Forest Exchange: Important Questions Regarding the Atmosphere's Role in the Delivery of Nutrient Nitrogen and Impacts on Nitrogen and Carbon Cycling

    NASA Astrophysics Data System (ADS)

    Carroll, M.; Shepson, P. B.; Bertman, S. B.; Sparks, J. P.; Holland, E. A.

    2002-12-01

    Atmosphere-Forest Exchange: Important Questions Regarding the Atmosphere's Role in the Delivery of Nutrient Nitrogen and Impacts on Nitrogen and Carbon Cycling Atmospheric composition and chemistry directly affect ecosystem nitrogen cycling and indirectly affect ecosystem carbon cycling and storage. Current understanding of atmosphere-forest nitrogen exchange and subsequent impacts is based almost exclusively on nitrogen deposition data obtained from networks using buckets placed in open areas, studies involving inorganic nitrogen, frequently with enhanced N deposition inputs applied only to soils, and that ignore multiple stresses (e.g., the combined effects of aerosols, ozone exposure, elevated CO2, and drought). Current models of nitrogen cycling treat deposited nitrogen (e.g., HNO3 and NO3-) as a permanent sink whereas data appear to indicate that photolytic and heterogeneous chemical processes occurring on surfaces and in dew can result in the re-evolution of gaseous species such as NO and HONO. Similarly, the direct uptake of gaseous nitrogen compounds by foliage has been neglected, compromising conclusions drawn from deposition experiments and ignoring a mechanism that may significantly affect nitrogen cycling and carbon storage, one that may become more significant with future atmospheric and climate change. We hypothesize that the atmosphere plays a significant role in the delivery of nutrient nitrogen to the N-limited mixed hardwood forest at the PROPHET research site at the University of Michigan Biological Station. We assert that a complete understanding of atmosphere- biosphere interactions and feedbacks is required to develop a predictive capability regarding forest response to increasing atmospheric CO2, reactive nitrogen, oxidants, and aerosols, increasing nitrogen and acidic deposition, and anticipated climate change. We further assert that conclusions drawn from studies that are limited to inorganic nitrogen, fertilization of soils, and/or that

  18. Impact origin of the Chesapeake Bay structure and the source of the North American tektites

    USGS Publications Warehouse

    Koeberl, C.; Poag, C.W.; Reimold, W.U.; Brandt, D.

    1996-01-01

    Seismic profiles, drill core samples, and gravity data suggest that a complex impact crater ???35.5 million years old and 90 kilometers in diameter is buried beneath the lower Chesapeake Bay. The breccia that fills the structure contains evidence of shock metamorphism, including impact melt breccias and multiple sets of planar deformation features (shock lamellae) in quartz and feldspar. The age of the crater and the composition of some breccia clasts are consistent with the Chesapeake Bay impact structure being the source of the North American tektites.

  19. Untangling the origin of viruses and their impact on cellular evolution.

    PubMed

    Nasir, Arshan; Sun, Feng-Jie; Kim, Kyung Mo; Caetano-Anollés, Gustavo

    2015-04-01

    The origin and evolution of viruses remain mysterious. Here, we focus on the distribution of viral replicons in host organisms, their morphological features, and the evolution of highly conserved protein and nucleic acid structures. The apparent inability of RNA viral replicons to infect contemporary akaryotic species suggests an early origin of RNA viruses and their subsequent loss in akaryotes. A census of virion morphotypes reveals that advanced forms were unique to viruses infecting a specific supergroup, while simpler forms were observed in viruses infecting organisms in all forms of cellular life. Results hint toward an ancient origin of viruses from an ancestral virus harboring either filamentous or spherical virions. Finally, phylogenetic trees built from protein domain and tRNA structures in thousands of genomes suggest that viruses evolved via reductive evolution from ancient cells. The analysis presents a complete account of the evolutionary history of cells and viruses and identifies viruses as crucial agents influencing cellular evolution.

  20. The Impact of Type of Examples on Originality: Explaining Fixation and Stimulation Effects

    ERIC Educational Resources Information Center

    Agogué, Marine; Kazakçi, Akin; Hatchuel, Armand; Le Masson, Pascal; Weil, Benoit; Poirel, Nicolas; Cassotti, Mathieu

    2014-01-01

    There are obstacles to creativity: one of them is called fixation effect, the fact that some knowledge about existing or obvious solutions is spontaneously activated and constrains the generation of new solutions. Converging evidence in cognitive psychology has indicated that the ability to generate original ideas can be limited by recently…

  1. The Impact of Generation and Country of Origin on the Mental Health of Children of Immigrants

    ERIC Educational Resources Information Center

    Montazer, Shirin; Wheaton, Blair

    2011-01-01

    The authors reexamine the study of generational differences in adjustment among the children of immigrants by arguing that the country of origin defines and shapes the adaptation process across generations. Using a sample of children in Toronto, the authors demonstrate that generational differences in the mental health of children occur only in…

  2. Origin of complex impact craters on native oxide coated silicon surfaces

    NASA Astrophysics Data System (ADS)

    Samela, Juha; Nordlund, Kai; Popok, Vladimir N.; Campbell, Eleanor E. B.

    2008-02-01

    Crater structures induced by impact of keV-energy Arn+ cluster ions on silicon surfaces are measured with atomic force microscopy. Complex crater structures consisting of a central hillock and outer rim are observed more often on targets covered with a native silicon oxide layer than on targets without the oxide layer. To explain the formation of these complex crater structures, classical molecular dynamics simulations of Ar cluster impacts on oxide coated silicon surfaces, as well as on bulk amorphous silica, amorphous Si, and crystalline Si substrates, are carried out. The diameter of the simulated hillock structures in the silicon oxide layer is in agreement with the experimental results, but the simulations cannot directly explain the height of hillocks and the outer rim structures when the oxide coated silicon substrate is free of defects. However, in simulations of 5keV /atom Ar12 cluster impacts, transient displacements of the amorphous silicon or silicon oxide substrate surfaces are induced in an approximately 50nm wide area surrounding the impact point. In silicon oxide, the transient displacements induce small topographical changes on the surface in the vicinity of the central hillock. The comparison of cluster stopping mechanisms in the various silicon oxide and silicon structures shows that the largest lateral momentum is induced in the silicon oxide layer during the impact; thus, the transient displacements on the surface are stronger than in the other substrates. This can be a reason for the higher frequency of occurrence of the complex craters on oxide coated silicon.

  3. Order or chaos? Origin and mode of emplacement of breccias in floors of large impact structures

    NASA Astrophysics Data System (ADS)

    Dressler, B. O.; Reimold, W. U.

    2004-09-01

    Breccias in the crater floor of large impact structures are pseudotachylites (sensu largo), authigenic monomict and polymict clastic-matrix breccias, so-called footwall breccias, and impact melt breccias. Pseudotachylite bodies in the center of large impact structures (e.g., Vredefort Dome, South Africa) appear to have a random distribution and orientation, but most dip steeply or vertically. Large bodies of pseudotachylite in the more distal sectors of the >200-km-diameter Sudbury Structure have been interpreted as ring and terrace collapse features. In the Vredefort Dome, networks of randomly distributed pseudotachylite veins accompany large ("mother lode") pseudotachylite dikes. In general, pseudotachylites in the floors of central parts of impact craters may form through explosive transfer of thermal shock energy, in a process that could be termed "flash replacement melting", whereas pseudotachylites at large distances from the centers of large impact structure are believed to have formed through friction leading to partial or complete melting, similar to the formation of tectonic pseudotachylites. In smaller structures (e.g., Ries and Slate Islands), clastic-matrix breccias instead of pseudotachylites occur as the most common breccias in the crater floors. They have a chaotic distribution pattern. Their dips are commonly also steep to vertical. Melt breccia dikes in the target rocks of the crater floor are associated with melt sheets that fill the lower part of the excavation cavity. At Vredefort, erosion has removed the coherent melt sheet, but melt breccia dikes (Vredefort Granophyre) in the crater floor are preserved. They are characterized by a remarkably homogeneous chemical composition and are believed to represent the initial, undifferentiated impact melt. Near the Vredefort collar, the Granophyre forms more or less concentric dikes. In the more central parts of the Dome, their orientation is more random, but, in places, may be controlled by the Archean

  4. Glasses of impact origin from Apollo 11, 12, 15, and 16 - Evidence for fractional vaporization and mare/highland mixing

    NASA Technical Reports Server (NTRS)

    Delano, J. W.; Lindsley, D. H.; Rudowski, R.

    1982-01-01

    Electron microprobe analyses have been performed on glasses of impact origin in Apollo 11 breccias (10059, 10060, 10061), Apollo 12 soil (12070), and Apollo 15 breccias (15318, 15425, 15426, 15427). These glasses were produced by shock melting of regolith, rather than of rock. Simple concepts for better understanding and interpreting the chemical data from impact glasses have been developed. These concepts are a significant improvement on earlier strategies, which centered principally on cluster analysis. Using ratios of refractory lithophile elements, the compositional effects of fractional vaporization often associated with impact melting to obtain chemical information about the mare and highland components in the regoliths parental to the glasses have been 'seen through'. This method is also applied to the mare-derived impact glasses from Apollo 16 in order to place constraints on the types of volcanic components occurring in Mare Nectaris. Since impact glasses can be used to derive chemical constraints on the indigenous lithologies comprising multi-component regoliths; the frequent occurrence of these glasses, as well as their low masses, should make them critically important for study when small quantities of grab-samples are returned by future unmanned spacecraft from planets, satellites, and asteroids where regoliths are present.

  5. On the origin and composition of Theia: Constraints from new models of the Giant Impact

    NASA Astrophysics Data System (ADS)

    Meier, M. M. M.; Reufer, A.; Wieler, R.

    2014-11-01

    Knowing the isotopic composition of Theia, the proto-planet which collided with the Earth in the Giant Impact that formed the Moon, could provide interesting insights on the state of homogenization of the inner Solar System at the late stages of terrestrial planet formation. We use the known isotopic and modeled chemical compositions of the bulk silicate mantles of Earth and Moon and combine them with different Giant Impact models, to calculate the possible ranges of isotopic composition of Theia in O, Si, Ti, Cr, Zr and W in each model. We compare these ranges to the isotopic composition of carbonaceous chondrites, Mars, and other Solar System materials. In the absence of post-impact isotopic re-equilibration, the recently proposed high angular momentum models of the Giant Impact ("impact-fission", Cúk, M., Stewart, S.T. [2012]. Science 338, 1047; and "merger", Canup, R.M. [2012]. Science 338, 1052) allow - by a narrow margin - for a Theia similar to CI-chondrites, and Mars. The "hit-and-run" model (Reufer, A., Meier, M.M.M., Benz, W., Wieler, R. [2012]. Icarus 221, 296-299) allows for a Theia similar to enstatite-chondrites and other Earth-like materials. If the Earth and Moon inherited their different mantle FeO contents from the bulk mantles of the proto-Earth and Theia, the high angular momentum models cannot explain the observed difference. However, both the hit-and-run as well as the classical or "canonical" Giant Impact model naturally explain this difference as the consequence of a simple mixture of two mantles with different FeO. Therefore, the simplest way to reconcile the isotopic similarity, and FeO dissimilarity, of Earth and Moon is a Theia with an Earth-like isotopic composition and a higher (∼20%) mantle FeO content.

  6. Environmental impacts on soil and groundwater at airports: origin, contaminants of concern and environmental risks.

    PubMed

    Nunes, L M; Zhu, Y-G; Stigter, T Y; Monteiro, J P; Teixeira, M R

    2011-11-01

    Environmental impacts of airports are similar to those of many industries, though their operations expand over a very large area. Most international impact assessment studies and environmental management programmes have been giving less focus on the impacts to soil and groundwater than desirable. This may be the result of the large attention given to air and noise pollution, relegating other environmental descriptors to a second role, even when the first are comparatively less relevant. One reason that contributes to such "biased" evaluation is the lack of systematic information about impacts to soil and groundwater from airport activities, something the present study intends to help correct. Results presented here include the review of over seven hundred documents and online databases, with the objective of obtaining the following information to support environmental studies: (i) which operations are responsible for chemical releases?; (ii) where are these releases located?; (iii) which contaminants of concern are released?; (iv) what are the associated environmental risks? Results showed that the main impacts occur as a result of fuel storage, stormwater runoff and drainage systems, fuel hydrant systems, fuel transport and refuelling, atmospheric deposition, rescue and fire fighting training areas, winter operations, electrical substations, storage of chemical products by airport owners or tenants, and maintenance of green areas. A new method for ranking environmental risks of organic substances, based on chemical properties, is proposed and applied. Results show that the contaminants with the highest risks are the perfluorochemicals, benzene, trichloroethylene and CCl(4). The obtained information provides a basis for establishing the planning and checking phases of environmental management systems, and may also help in the best design of pollution prevention measures in order to avoid or reduce significant environmental impacts from airports.

  7. Recognizing Question Entailment for Medical Question Answering

    PubMed Central

    Abacha, Asma Ben; Dina, Demner-Fushman

    2016-01-01

    With the increasing heterogeneity and specialization of medical texts, automated question answering is becoming more and more challenging. In this context, answering a given medical question by retrieving similar questions that are already answered by human experts seems to be a promising solution. In this paper, we propose a new approach for the detection of similar questions based on Recognizing Question Entailment (RQE). In particular, we consider Frequently Asked Question (FAQs) as a valuable and widespread source of information. Our final goal is to automatically provide an existing answer if FAQ similar to a consumer health question exists. We evaluate our approach using consumer health questions received by the National Library of Medicine and FAQs collected from NIH websites. Our first results are promising and suggest the feasibility of our approach as a valuable complement to classic question answering approaches. PMID:28269825

  8. The impact of migration on pregnancy outcomes among Mexican-origin women.

    PubMed

    Hessol, Nancy A; Fuentes-Afflick, Elena

    2014-06-01

    To examine the association between individual-level and state-level migration status in the United States (US) and the risk of preterm and low birth weight infants among Mexican-origin women. We performed secondary analysis of the 2003 US birth certificate data for 641,474 infants born to Mexican-origin Latina women. The dependent variables were prematurity and low birth weight. The primary independent variables were individual- (maternal) and state-level migration status. Logistic regression analysis estimated the relationship between maternal and state-level migration status, maternal and infant factors, and the risk of prematurity and low birth weight. Women who were born in Mexico had less education and use of prenatal care than US-born, Mexican-origin women but also fewer preterm or low birth weight infants. After adjusting for maternal and infant characteristics, women who were born and resided in Mexico at delivery were 37-64% less likely to deliver preterm or low birth weight infants, and women who were born in Mexico and resided in the US had a 20-21% lower risk as compared to women who were born and resided in the same US state. Women who delivered in states with a higher proportion of Mexican-origin mothers were slightly more likely to deliver a preterm infant and slightly less likely to give birth to a low birth weight infant. These findings support the perinatal advantage of Mexican-born women and provide evidence that both individual- as well as state-level migration factors influence perinatal outcomes.

  9. Students' Perceptions about Peer Assessment for Writing: Their Origin and Impact on Revision Work

    ERIC Educational Resources Information Center

    Kaufman, Julia H.; Schunn, Christian D.

    2011-01-01

    We investigate students' negative perceptions about an online peer assessment system for undergraduate writing across the disciplines. Specifically, we consider the nature of students' resistance to peer assessment; what factors influence that resistance; and how students' perceptions impact their revision work. We do this work by first examining…

  10. A Large Impact Origin for Sputnik Planum and Surrounding Terrains, Pluto?

    NASA Astrophysics Data System (ADS)

    Schenk, Paul M.; McKinnon, William; Moore, Jeffrey; Nimmo, Francis; Stern, S. Alan; Weaver, Hal; Ennico, Kimberly; Olkin, Cathy; Young, Leslie

    2015-11-01

    One of the most prominent features on Pluto discovered by New Horizons is the oval-shaped bright deposit within western Tombaugh Regio (all names used herein are informal). This smooth bright deposit, provisionally identified with frozen nitrogen and methane and informally referred to as Sputnik Planum, is bounded on the northeast by an arcuate scarp (Cousteau Rupes). The smooth bright material there embays what appears to be an eroded plateau 1-2 km high. The arcuate scarp leads to speculation that the deposits formed in an ancient impact basin, but detailed mapping at 2 km pixel scales suggests that this large structure is more complex than any simple impact basin. To the southwest are a series of high peaks and massifs (also embayed by bright material) but these broken massifs have a different morphology from Cousteau Rupes, being both higher and more disrupted. The southern section of this putative 800-km-wide circular structure is completely missing as smooth material extends well to the south of the nominal rim location. A possible analog occurs at the “other End of the Solar System” on Mercury, in Caloris Basin. This 1400-km-wide impact basin is also irregular in shape, with large deviations form circularity, and occasional large massifs along some rim segments. Post-impact smooth plains embay the rim scarp in some areas, though these are likely to be volcanic plains on Mercury. The relief of the rim scarps to the NE and SW and putative evidence for convection within Sputnik Planum suggests that the floor of the deposits lies 1-3 km below the mean surface (pending stereo mapping). This depth is consistent with the filling of an ancient impact basin with ices, deposited either volcanically or atmospherically, although other explanations are also possible. This work was supported by NASA's New Horizons project.

  11. Origin and emplacement of impactites in the Chesapeake Bay impact structure, Virginia, USA

    USGS Publications Warehouse

    Horton, J.W.; Gohn, G.S.; Powars, D.S.; Edwards, L.E.

    2007-01-01

    The late Eocene Chesapeake Bay impact structure, located on the Atlantic margin of Virginia, may be Earth's best-preserved large impact structure formed in a shallow marine, siliciclastic, continental-shelf environment. It has the form of an inverted sombrero in which a central crater ???40 km in diameter is surrounded by a shallower brim, the annular trough, that extends the diameter to ???85 km. The annular trough is interpreted to have formed largely by the collapse and mobilization of weak sediments. Crystalline-clast suevite, found only in the central crater, contains clasts and blocks of shocked gneiss that likely were derived from the fragmentation of the central-uplift basement. The suevite and entrained megablocks are interpreted to have formed from impact-melt particles and crystalline-rock debris that never left the central crater, rather than as a fallback deposit. Impact-modified sediments in the annular trough include megablocks of Cretaceous nonmarine sediment disrupted by faults, fluidized sands, fractured clays, and mixed-sediment intercalations. These impact-modified sediments could have formed by a combination of processes, including ejection into and mixing of sediments in the water column, rarefaction-induced fragmentation and clastic injection, liquefaction and fluidization of sand in response to acoustic-wave vibrations, gravitational collapse, and inward lateral spreading. The Exmore beds, which blanket the entire crater and nearby areas, consist of a lower diamicton member overlain by an upper stratified member. They are interpreted as unstratified ocean-resurge deposits, having depositional cycles that may represent stages of inward resurge or outward anti-resurge flow, overlain by stratified fallout of suspended sediment from the water column. ?? 2008 The Geological Society of America. All rights reserved.

  12. Impact origin of the Avak structure, Arctic Alaska, and genesis of the Barrow gas fields

    SciTech Connect

    Kirschner, C.E. ); Grantz, A.; Mullen, M.W. )

    1992-05-01

    Geophysical and subsurface geologic data suggest that the Avak structure, which underlies the Arctic Coastal Plain 12 km southeast of Barrow, Alaska, is a hypervelocity meteorite or comet impact structure. The structure is a roughly circular area of uplifted, chaotically deformed Upper Triassic to Lower Cretaceous sedimentary rocks 8 km in diameter that is bounded by a ring of anastomosing, inwardly dipping, listric normal faults 12 km in diameter. A zone of gently outward-dipping sedimentary country rocks forms a discontinuous ring of rim anticlines within the peripheral ring of normal faults. Beyond these anticlines, the sedimentary rocks are almost flat-lying. Data concerning the age of the Avak structure are not definitive. If submarine landslide deposits in the upper part of the Aptian and Albian Torok Formation, in the subsurface 200 km to the east, were triggered by the Avak event, then the Avak meteorite struck a submerged marine shelf about 100 [plus minus] 5 Ma. However, the impact features found at Avak characterize the distal zones of meteorite impact structures. Fused rocks, plastic deformation, and shock-metamorphic minerals found in more proximal zones of impact structures are apparently missing. These observations, and the lack of Avak ejecta in cuttings and cores from the Torok Formation and Nanushuk Group in surrounding test wells, indicate that the impact event postdated these beds. In this case, the Avak meteorite struck a Late Cretaceous or Tertiary marine shelf or coastal plain between the Cenomanian (ca. 95 Ma), and deposition of the basal beds of the overlying late Pliocene and Quaternary Gubik Formation (ca. 3 Ma).

  13. Socrates' questions: a focus for nursing.

    PubMed

    Bunkers, Sandra S

    2004-07-01

    This column focuses on the philosophical dialogue originated by Socrates. Six questions that Socrates would ask the ancient Greeks are explored in discussing a book written by Phillips entitled Six Questions of Socrates. These questions were: What is virtue? What is moderation? What is justice? What is good? What is courage? What is piety? A human becoming perspective is used as a lens to view the discussion on these questions and the question is posed, "What would it be like to frame discussions on health and quality of life around Socrates' questions?" Parse's teaching-learning processes are presented as a means of creating an environment where dialogue on these questions can occur.

  14. Impact melting of frozen oceans on the early Earth: implications for the origin of life.

    PubMed

    Bada, J L; Bigham, C; Miller, S L

    1994-02-01

    Without sufficient greenhouse gases in the atmosphere, the early Earth would have become a permanently frozen planet because the young Sun was less luminous than it is today. Several resolutions to this faint young Sun-frozen Earth paradox have been proposed, with an atmosphere rich in CO2 being the one generally favored. However, these models assume that there were no mechanisms for melting a once frozen ocean. Here we show that bolide impacts between about 3.6 and 4.0 billion years ago could have episodically melted an ice-covered early ocean. Thaw-freeze cycles associated with bolide impacts could have been important for the initiation of abiotic reactions that gave rise to the first living organisms.

  15. [Assessment of the impact of GMO of plant origin on rat progeny development in 3 generations].

    PubMed

    Tyshko, N V; Zhminchenko, V M; Pashorina, V A; Seliaskin, K E; Saprykin, V P; Utembaeva, N T; Tutel'ian, V A

    2011-01-01

    The publication presents the results of assessment of impact of genetically modified (GM) maize Liberty Link on prenatal and postnatal development of progeny of 3 generations of Wistar rats. A total of 630 adult animals and 2837 pups were used in the experiment. The animals were divided into 5 groups which got the diets with inclusion of maize: the animals of the experimental group got the diet with the GM-maize, animals of the control group - with near isogenic conventional analogue of the GM-maize, animals of the 1st, 2nd and 3rd reference groups - conventional varieties of maize ROSS 144 MV, ROSS 197 MVW, Dokuchayevskaya 250 MV respectively. The maize was included in the diet at maximum possible level not violating the balance of basic nutrients. Analysis of the data obtained during the study did not reveal any impact of GM-maize on rat progeny development.

  16. Impact melting of frozen oceans on the early Earth: implications for the origin of life

    NASA Technical Reports Server (NTRS)

    Bada, J. L.; Bigham, C.; Miller, S. L.

    1994-01-01

    Without sufficient greenhouse gases in the atmosphere, the early Earth would have become a permanently frozen planet because the young Sun was less luminous than it is today. Several resolutions to this faint young Sun-frozen Earth paradox have been proposed, with an atmosphere rich in CO2 being the one generally favored. However, these models assume that there were no mechanisms for melting a once frozen ocean. Here we show that bolide impacts between about 3.6 and 4.0 billion years ago could have episodically melted an ice-covered early ocean. Thaw-freeze cycles associated with bolide impacts could have been important for the initiation of abiotic reactions that gave rise to the first living organisms.

  17. Cleopatra crater on Venus - Venera 15/16 data and impact/volcanic origin controversy

    NASA Astrophysics Data System (ADS)

    Basilevsky, A. T.; Ivanov, B. A.

    1990-02-01

    The morphology and morphometry of the 100-km diameter, 2.4-km deep Cleopatra crater on Venus are examined using Venera 15/16 images. The Cleopatra crater is compared to circular structures on Venus, Mercury, Mars, the earth and the moon. Consideration is given to the possible causes for the genesis of the Cleopatra crater. It is concluded that Cleopatra has a clear impact basin morphology with an anomalous crater depth.

  18. Questions, Questioning Techniques, and Effective Teaching.

    ERIC Educational Resources Information Center

    Wilen, William W., Ed.

    This book focuses on questioning techniques and strategies teachers may employ to make the difference between active and passive learning in the classroom. There are nine chapters: (1) Why Questions? (Ambrose A. Clegg, Jr.); (2) Review of Research on Questioning Techniques (Meredith D. Gall and Tom Rhody); (3) The Multidisciplinary World of…

  19. Impact of remanent magnetic field on the heat load of original CEBAF cryomodule

    SciTech Connect

    Ciovati, Gianluigi; Cheng, Guangfeng; Drury, Michael; Fischer, John; Geng, Rongli

    2016-11-22

    The heat load of the original cryomodules for the CEBAF accelerator is ~50% higher than the target value of 100 W at 2.07 K for refurbished cavities operating at an accelerating gradient of 12.5 MV/m. This issue is due to the quality factor of the cavities being ~50% lower in the cryomodule than when tested in a vertical cryostat, even at low RF field. Previous studies were not conclusive about the origin of the additional losses. We present the results of a systematic study of the additional losses in a five-cell cavity from a decommissioned cryomodule after attaching components, which are part of the cryomodule, such as the cold tuner, the He tank and the cold magnetic shield, prior to cryogenic testing in a vertical cryostat. Flux-gate magnetometers and temperature sensors are used as diagnostic elements. Different cool-down procedures and tests in different residual magnetic fields were investigated during the study. Here, three flux-gate magnetometers attached to one of the cavities installed in the refurbished cryomodule C50-12 confirmed the hypothesis of high residual magnetic field as a major cause for the increased RF losses.

  20. Impact of remanent magnetic field on the heat load of original CEBAF cryomodule

    DOE PAGES

    Ciovati, Gianluigi; Cheng, Guangfeng; Drury, Michael; ...

    2016-11-22

    The heat load of the original cryomodules for the CEBAF accelerator is ~50% higher than the target value of 100 W at 2.07 K for refurbished cavities operating at an accelerating gradient of 12.5 MV/m. This issue is due to the quality factor of the cavities being ~50% lower in the cryomodule than when tested in a vertical cryostat, even at low RF field. Previous studies were not conclusive about the origin of the additional losses. We present the results of a systematic study of the additional losses in a five-cell cavity from a decommissioned cryomodule after attaching components, whichmore » are part of the cryomodule, such as the cold tuner, the He tank and the cold magnetic shield, prior to cryogenic testing in a vertical cryostat. Flux-gate magnetometers and temperature sensors are used as diagnostic elements. Different cool-down procedures and tests in different residual magnetic fields were investigated during the study. Here, three flux-gate magnetometers attached to one of the cavities installed in the refurbished cryomodule C50-12 confirmed the hypothesis of high residual magnetic field as a major cause for the increased RF losses.« less

  1. Evaluation d'impact sur la santé et évaluation d'impact sur l'équité en santé : éventail de pratiques et questions de recherche.

    PubMed

    Villeval, Mélanie; Bidault, Elsa; Lang, Thierry

    2016-09-01

    L'Evaluation d'Impact sur la Santé (EIS) se développe au niveau international et est encore au stade émergent en France. Elle vise à évaluer les effets positifs et négatifs potentiels d'un projet, d'un programme ou d'une politique sur la santé. L'objectif est de produire des recommandations en direction des décideurs, afin d'en maximiser les effets positifs et d'en diminuer les effets négatifs. L'EIS est un moyen particulièrement intéressant d'action sur les déterminants de la santé au-delà des comportements individuels et du système de santé. Les politiques de logement, de transport, de solidarité, économiques, etc. ont, en effet, des impacts souvent non prévus sur la santé. Au-delà des effets sur la santé, l'EIS doit aussi permettre d'apprécier la distribution de ces effets dans la population.Si la préoccupation pour l'équité en santé est centrale dans l'EIS, elle reste cependant difficilement traduite en pratique. Face à cette difficulté, des démarches d'évaluation d'impact ont été développées pour renforcer la prise en compte de l'équité à chaque étape de l'EIS ou « Equity Focused Health Impact Assessment », ou prendre en compte les impacts sur les inégalités de santé de façon spécifique. Ainsi, l'Evaluation de l'Impact sur l'Equité en Santé (EIES) semble, par exemple, particulièrement intéressante pour évaluer l'impact sur les inégalités de projets dans le champ sanitaire.L'EIS et l'EIES posent de nombreuses questions de recherche, notamment autour de la réunion, dans une même démarche, du politique, du citoyen et de l'expert. La participation des populations vulnérables potentiellement affectées par la politique évaluée est une valeur centrale de l'EIS, mais pose des questions d'acceptabilité sociale. La collaboration avec les décideurs politiques est également un enjeu majeur. Les difficultés méthodologiques, notamment de quantification des impacts, peuvent constituer des freins à la promotion

  2. BICEP2, Planck, spinorial space-time, pre-Big Bang.. On the possible origin of primordial CMB B-modes and gravitational waves. Potentialities of alternative cosmologies and open questions

    NASA Astrophysics Data System (ADS)

    Gonzalez-Mestres, Luis

    2015-05-01

    The field of Cosmology is currently undergoing a positive and constructive crisis. Controversies concerning inflation are not really new. But after the 2013-2014 Planck and BICEP2 announcements, and the more recent joint analysis by Planck, BICEP2 and the Keck Array (PBKA), the basic issues can involve more direct links between the Mathematical Physics aspects of cosmological patterns and the interpretation of experimental results. Open questions and new ideas on the foundations of Cosmology can emerge, while future experimental and observational programs look very promising. The BICEP2 result reporting an excess of B-mode polarization signal of the cosmic microwave background (CMB) radiation was initially presented as a signature of primordial gravitational waves from cosmic inflation. But polarized dust emission can be at the origin of such a signal, and the evidence claimed by BICEP2 is no longer secure after the PBKA analysis. Furthermore, even assuming that significant CMB B-mode polarization has indeed been generated by the early Universe, its theoretical and cosmological interpretation would be far from obvious. Inflationary gravitational waves are not the only possible source of primordial CMB B-modes. Alternative cosmologies such as pre-Big Bang patterns and the spinorial space-time (SST) we introduced in 1996-97 can naturally produce this polarization. Furthermore, the SST automatically generates for each comoving observer a local privileged space direction (PSD) whose existence may have been confirmed by Planck data. If such a PSD exists, vector perturbations have most likely been strong in the early Universe and may have produced CMB B-modes. Pre-Big Bang cosmologies can also generate gravitational waves in the early Universe without inflation. After briefly describing detectors devoted to the study of the CMB polarization, we discuss the situation emerging from BICEP2 results, Planck results and the PBKA analysis. In particular, we further analyze

  3. Evidence for an 800 km Diameter Impact Structure in Meridiani Planum and Associated Channels and Basins: A Connection with the Origin of the Hematite Deposits?

    NASA Technical Reports Server (NTRS)

    Newsom, H. E.; Barber, C. A.; Schelble, R. T.; Hare, T. M.; Feldman, W. C.; Sutherland, V.; Gordon, H.; Thorsos, I. E.; Livingston, A.; Lewis, K.

    2003-01-01

    Topographic evidence for the existence of an early 800 km diameter multi-ringed impact structure, and evidence for fluvial and lacustrine environments in Meridiani Planum suggests a connection with the origin of the hematite deposits present in the region.

  4. Origin of the Sudbury Complex by meteoritic impact: Neodymium isotopic evidence

    USGS Publications Warehouse

    Faggart, B.E.; Basu, A.R.; Tatsumoto, M.

    1985-01-01

    Samarium-neodymium isotopic data on whole rocks and minerals of the Sudbury Complex in Canada gave an igneous crystallization age of 1840 ?? 21 ?? 106 years. The initial epsilon neodymium values for 15 whole rocks are similar to those for average upper continental crust, falling on the crustal trend of neodymium isotopic evolution as defined by shales. The rare earth element concentration patterns of Sudbury rocks are also similar to upper crustal averages. These data suggest that the Sudbury Complex formed from melts generated in the upper crust and are consistent with a meteoritic impact.

  5. The cratering record on Mercury and the origin of impacting objects

    NASA Technical Reports Server (NTRS)

    Strom, Robert G.; Neukum, Gerhard

    1988-01-01

    The cratering records of terrestrial planets are discussed with special consideration given to Mercury. The geologic units on Mercury most relevant to its cratering record are reviewed, and new observations are presented on the issues of equilibrium and saturation. The implications of the Mercurian cratering record for geologic processes are examined. Particular attention is given to the origin of objects responsible for the period of late heavy bombardment on terrestrial planets; it is suggested that the impactors were accretional remnants left over from the formation of the terrestrial planets and confined to the inner solar system. The cratering record in the outer solar system may have been produced largely by objects in planetocentric orbits.

  6. Impact of fermentation on nitrogenous compounds of cocoa beans (Theobroma cacao L.) from various origins.

    PubMed

    Hue, C; Gunata, Z; Breysse, A; Davrieux, F; Boulanger, R; Sauvage, F X

    2016-02-01

    Tangential filtration technique was used to separate and quantify three different fractions of nitrogenous compounds depending on their molecular size, during cocoa fermentation. On every phenotype and origin analyzed, protein profile of non-fermented samples was similar. During fermentation course, proteins get degraded with a concomitant increase in amino acids content. Peptides between 3 and 10 kDa were observed at low levels. A strong correlation between amino acids and ammonia nitrogen, a fermentation marker was found. Attention was drawn on each fraction, and enabled to point out other phenomenon occurring during fermentation. The migration of some nitrogenous compounds towards the bean shell during fermentation was demonstrated. Acetone treatment of cocoa powder prior to SDS-PAGE led to losses of nitrogenous compounds. This result gives clues on the tanning phenomenon carried out by polyphenols on nitrogenous compounds, phenomenon which increases during fermentation.

  7. Metabolites of Microbial Origin with an Impact on Health: Ochratoxin A and Biogenic Amines

    PubMed Central

    Russo, Pasquale; Capozzi, Vittorio; Spano, Giuseppe; Corbo, Maria R.; Sinigaglia, Milena; Bevilacqua, Antonio

    2016-01-01

    Safety and quality are significant challenges for food; namely, safety represents a big threat all over the world and is one of the most important goal to be achieved in both Western Society and Developing Countries. Wine safety mainly relies upon some metabolites and many of them are of microbial origin. The main goal of this review is a focus on two kinds of compounds (biogenic amines and mycotoxins, mainly Ochratoxin A) for their deleterious effects on health. For each class of compounds, we will focus on two different traits: (a) synthesis of the compounds in wine, with a brief description of the most important microorganisms and factors leading this phenomenon; (b) prevention and/or correction strategies and new trends. In addition, there is a focus on a recent predictive tool able to predict toxin contamination of grape, in order to perform some prevention approaches and achieve safe wine. PMID:27092133

  8. Impact of Parental Bos taurus and Bos indicus Origins on Copy Number Variation in Traditional Chinese Cattle Breeds

    PubMed Central

    Zhang, Liangzhi; Jia, Shangang; Plath, Martin; Huang, Yongzhen; Li, Congjun; Lei, Chuzhao; Zhao, Xin; Chen, Hong

    2015-01-01

    Copy number variation (CNV) is an important component of genomic structural variation and plays a role not only in evolutionary diversification but also in domestication. Chinese cattle were derived from Bos taurus and Bos indicus, and several breeds presumably are of hybrid origin, but the evolution of CNV regions (CNVRs) has not yet been examined in this context. Here, we of CNVRs, mtDNA D-loop sequence variation, and Y-chromosomal single nucleotide polymorphisms to assess the impact of maternal and paternal B. taurus and B. indicus origins on the distribution of CNVRs in 24 Chinese domesticated bulls. We discovered 470 genome-wide CNVRs, only 72 of which were shared by all three Y-lineages (B. taurus: Y1, Y2; B. indicus: Y3), whereas 265 were shared by inferred taurine or indicine paternal lineages, and 228 when considering their maternal taurine or indicine origins. Phylogenetic analysis uncovered eight taurine/indicine hybrids, and principal component analysis on CNVs corroborated genomic exchange during hybridization. The distribution patterns of CNVRs tended to be lineage-specific, and correlation analysis revealed significant positive or negative co-occurrences of CNVRs across lineages. Our study suggests that CNVs in Chinese cattle partly result from selective breeding during domestication, but also from hybridization and introgression. PMID:26260653

  9. Impact origin of the Avak Structure, Arctic Alaska, and genesis of the Barrow gas fields

    USGS Publications Warehouse

    Kirschner, C.E.; Grantz, A.; Mullen, M.W.

    1992-01-01

    Geophysical and subsurface geologic data suggest that the Avak structure, which underlies the Arctic Coastal Plain 12 km southeast of Barrow, Alaska, is a hypervelocity meteorite or comet impact structure. The structure is a roughly circular area of uplifted, chaotically deformed Upper Triassic to Lower Cretaceous sedimentary rocks 8 km in diameter that is bounded by a ring of anastomosing, inwardly dipping, listric normal faults 12 km in diameter. Examination of cores from the Barrow gas fields and data concerning the age of the Avak structure suggest that the Avak meteorite struck a Late Cretaceous or Tertiary marine shelf or coastal plain between the Cenomanian (ca. 95 Ma), and deposition of the basal beds of the overlying late Pliocene and Quaternary Gubik Formation (ca. 3 Ma). -from Authors

  10. The origin of the moon and the single-impact hypothesis III.

    PubMed

    Benz, W; Cameron, A G; Melosh, H J

    1989-01-01

    In previous papers in this series the smoothed particle hydrodynamics method (SPH) has been used to explore the conditions in which a major planetary collision may have been responsible for the formation of the Moon. In Paper II (W. Benz, W.L. Slattery, and A.G.W. Cameron 1987, Icarus 71, 30-45) it was found that the optimum conditions were obtained when the mass ratio of the impactor to the protoearth was 0.136. In the present paper we investigate the importance of the equation of state by running this optimum case several times and varying the equation of state and other related parameters. The two equations of state compared are the Tillotson (used in the previous papers) and the CHART D/CSQ ANEOS. Because of differences in these equations of state, including the fact that different types of rocks were used in association with each, it was not possible to prepare initial planetary models that were comparable in every respect, so several different simulations were necessary in which different planetary parameters were matched between the equations of state. We also used a new version of the SPH code. The results reaffirmed the previous principal conclusions: the collisions produced a disk of rocky material in orbit, with most of the material derived from the impacting object. These results indicate that the equation of state is not a critical factor in determining the amount of material thrown into orbit. This confirms the conclusions of Paper II that gravitational torques, and not pressure gradients, inject the orbiting mass. However, the way this mass is distributed in orbit is affected by the equation of state and the choice of rock material, the Tillotson equation for granite giving slightly larger mean orbital radius for the particles left in orbit than the ANEOS dunite for the same impact parameter. We also find, compared to Paper II, that in all subsequent cases the new SPH code leads to a slightly less extended prelunar accretion disk. We think this is

  11. Germ Cell Origins of Posttraumatic Stress Disorder Risk: The Transgenerational Impact of Parental Stress Experience.

    PubMed

    Rodgers, Ali B; Bale, Tracy L

    2015-09-01

    Altered stress reactivity is a predominant feature of posttraumatic stress disorder (PTSD) and may reflect disease vulnerability, increasing the probability that an individual will develop PTSD following trauma exposure. Environmental factors, particularly prior stress history, contribute to the developmental programming of the hypothalamic-pituitary-adrenal stress axis. Critically, the consequences of stress experiences are transgenerational, with parental stress exposure impacting stress reactivity and PTSD risk in subsequent generations. Potential molecular mechanisms underlying this transmission have been explored in rodent models that specifically examine the paternal lineage, identifying epigenetic signatures in male germ cells as possible substrates of transgenerational programming. Here, we review the role of these germ cell epigenetic marks, including posttranslational histone modifications, DNA methylation, and populations of small noncoding RNAs, in the development of offspring stress axis sensitivity and disease risk.

  12. The Long-Term Impacts of Medicaid Exposure in Early Childhood: Evidence from the Program's Origin*

    PubMed Central

    Boudreaux, Michel H.; Golberstein, Ezra; McAlpine, Donna D.

    2016-01-01

    This paper examines the long-term impact of exposure to Medicaid in early childhood on adult health and economic status. The staggered timing of Medicaid's adoption across the states created meaningful variation in cumulative exposure to Medicaid for birth cohorts that are now in adulthood. Analyses of the Panel Study of Income Dynamics suggest exposure to Medicaid in early childhood (age 0-5) is associated with statistically significant and meaningful improvements in adult health (age 25-54), and this effect is only seen in subgroups targeted by the program. Results for economic outcomes are imprecise and we are unable to come to definitive conclusions. Using separate data we find evidence of two mechanisms that could plausibly link Medicaid's introduction to long-term outcomes: contemporaneous increases in health services utilization for children and reductions in family medical debt. PMID:26763123

  13. Impact origin of the Avak structure, Arctic Alaska, and genesis of the Barrow gas fields

    SciTech Connect

    Kirschner, C.E.; Grantz, A. )

    1990-05-01

    Geophysical and subsurface geologic data confirm that the Avak structure, which underlies the coastal plain 12 km southeast of Barrow, is an impact crater. The structure is a roughly circular area of chaotically deformed Upper Triassic to Lower Cretaceous sedimentary rocks 8 km in diameter bounded by a ring of anastomozing, inwardly dipping, listric normal faults. Beyond the ring, these rocks are almost flat. Basement is strongly deformed Ordovician and Silurian argillite. Strong density and seismic velocity contrast between the argillite and the overlying strata produce gravity and seismic reflection signatures that define ring anticlines around the disturbed zone and a structural high at its center. The Mesozoic strata are about 760 m thick in the adjacent Barrow gas fields, where the Neocomian pebble shale unit and the gas-producing Lower Jurassic Barrow sandstone lie at average subsea depths of 438 m and 670 m, respectively. In the Avak well, drilled on the central high, the pebble shale unit and Barrow sandstone lie near the surface, documenting more than 500 m of uplift at the high. The cores in this well also show steep dips (30-90{degree}), abundant tectonic breccia with argillite clasts 90 m above basement, fractured quartz grains, and shatter cones resembling those found in well-documented meteorite craters. Stratigraphic data suggest that the Avak meteorite struck a late Early Cretaceous marine shelf, produced peripheral highs that trapped gas in the Barrow fields, and triggered massive landslides on the adjacent outer shelf. The age of the landslides dates the impact at about 105 Ma.

  14. Framing choice: The origins and impact of consumer rhetoric in US health care debates.

    PubMed

    Lee, Nancy S

    2015-08-01

    This paper examines the origins of consumerist discourse in health care from a communication perspective via a historical textual analysis of health writing in popular magazines from 1930 to 1949. The focus is on Consumers Union's Consumer Reports and the American Medical Association's lay health magazine, Hygeia. Findings from Consumer Reports show that the consumer movement of the 1930s-40s staunchly advocated for universal health insurance. Whereas consumer rights language nowadays tends towards individual choice and personal responsibility, consumerism in health care during that era articulated ideas about consumer citizenship, framing choice and responsibility in collectivist terms and health care as a social good. This paper also illuminates the limits and weaknesses of a central tenet in consumerism-freedom of choice-by analyzing stories in Hygeia about the doctor-patient relationship. A textual analysis finds that the AMA's justification in the 1930s-40s against socialized medicine, i.e., the freedom to choose a doctor, was in practice highly controlled by the medical profession. Findings show that long before the rhetoric of the "empowered consumer" became popular, some patients exercised some choice even in an era when physicians achieved total professional dominance. But these patients were few and tend to occupy the upper socioeconomic strata of US society. In reality choice was an illusion in a fee-for-service era when most American families could not afford the costs of medical care.

  15. Developmental origins of cardiovascular disease: Impact of early life stress in humans and rodents.

    PubMed

    Murphy, M O; Cohn, D M; Loria, A S

    2017-03-01

    The Developmental Origins of Health and Disease (DOHaD) hypothesizes that environmental insults during childhood programs the individual to develop chronic disease in adulthood. Emerging epidemiological data strongly supports that early life stress (ELS) given by the exposure to adverse childhood experiences is regarded as an independent risk factor capable of predicting future risk of cardiovascular disease. Experimental animal models utilizing chronic behavioral stress during postnatal life, specifically maternal separation (MatSep) provides a suitable tool to elucidate molecular mechanisms by which ELS increases the risk to develop cardiovascular disease, including hypertension. The purpose of this review is to highlight current epidemiological studies linking ELS to the development of cardiovascular disease and to discuss the potential molecular mechanisms identified from animal studies. Overall, this review reveals the need for future investigations to further clarify the molecular mechanisms of ELS in order to develop more personalized therapeutics to mitigate the long-term consequences of chronic behavioral stress including cardiovascular and heart disease in adulthood.

  16. Impacts of produced water origin on bacterial community structures of activated sludge.

    PubMed

    Wang, Zhenyu; Pan, Feng; Hesham, Abd El-Latif; Gao, Yingxin; Zhang, Yu; Yang, Min

    2015-11-01

    The purpose of this study was to reveal how activated sludge communities respond to influent quality and indigenous communities by treating two produced waters from different origins in a batch reactor in succession. The community shift and compositions were investigated using Polymerase Chain Reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and further 16S ribosomal DNA (rDNA) clone library analysis. The abundance of targeted genes for polycyclic aromatic hydrocarbon (PAH) degradation, nahAc/phnAc and C12O/C23O, was tracked to define the metabolic ability of the in situ microbial community by Most Probable Number (MPN) PCR. The biosystem performed almost the same for treatment of both produced waters in terms of removals of chemical oxygen demand (COD) and PAHs. Sludge communities were closely associated with the respective influent bacterial communities (similarity>60%), while one sludge clone library was dominated by the Betaproteobacteria (38%) and Bacteriodetes (30%) and the other was dominated by Gammaproteobacteria (52%). This suggested that different influent and water quality have an effect on sludge community compositions. In addition, the existence of catabolic genes in sludge was consistent with the potential for degradation of PAHs in the treatment of both produced waters.

  17. The origin, global distribution, and functional impact of the human 8p23 inversion polymorphism.

    PubMed

    Salm, Maximilian P A; Horswell, Stuart D; Hutchison, Claire E; Speedy, Helen E; Yang, Xia; Liang, Liming; Schadt, Eric E; Cookson, William O; Wierzbicki, Anthony S; Naoumova, Rossi P; Shoulders, Carol C

    2012-06-01

    Genomic inversions are an increasingly recognized source of genetic variation. However, a lack of reliable high-throughput genotyping assays for these structures has precluded a full understanding of an inversion's phylogenetic, phenotypic, and population genetic properties. We characterize these properties for one of the largest polymorphic inversions in man (the ∼4.5-Mb 8p23.1 inversion), a structure that encompasses numerous signals of natural selection and disease association. We developed and validated a flexible bioinformatics tool that utilizes SNP data to enable accurate, high-throughput genotyping of the 8p23.1 inversion. This tool was applied retrospectively to diverse genome-wide data sets, revealing significant population stratification that largely follows a clinal "serial founder effect" distribution model. Phylogenetic analyses establish the inversion's ancestral origin within the Homo lineage, indicating that 8p23.1 inversion has occurred independently in the Pan lineage. The human inversion breakpoint was localized to an inverted pair of human endogenous retrovirus elements within the large, flanking low-copy repeats; experimental validation of this breakpoint confirmed these elements as the likely intermediary substrates that sponsored inversion formation. In five data sets, mRNA levels of disease-associated genes were robustly associated with inversion genotype. Moreover, a haplotype associated with systemic lupus erythematosus was restricted to the derived inversion state. We conclude that the 8p23.1 inversion is an evolutionarily dynamic structure that can now be accommodated into the understanding of human genetic and phenotypic diversity.

  18. Nature, Origin, Potential Composition, and Climate Impact of the Asian Tropopause Aerosol Layer (ATAL)

    NASA Technical Reports Server (NTRS)

    Fairlie, T. D.; Vernier, J.-P.; Thomason, L. W.; Natarajan, M.; Bedka, K.; Wienhold, F.; Bian J.; Martinsson, B.

    2015-01-01

    Satellite observations from SAGE II and CALIPSO indicate that summertime aerosol extinction has more than doubled in the Asian Tropopause Aerosol Layer (ATAL) since the late 1990s. Here we show remote and in-situ observations, together with results from a chemical transport model (CTM), to explore the likely composition, origin, and radiative forcing of the ATAL. We show in-situ balloon measurements of aerosol backscatter, which support the high levels observed by CALIPSO since 2006. We also show in situ measurements from aircraft, which indicate a predominant carbonaceous contribution to the ATAL (Carbon/Sulfur ratios of 2- 10), which is supported by the CTM results. We show that the peak in ATAL aerosol lags by 1 month the peak in CO from MLS, associated with deep convection over Asia during the summer monsoon. This suggests that secondary formation and growth of aerosols in the upper troposphere on monthly timescales make a significant contribution to ATAL. Back trajectory calculations initialized from CALIPSO observations provide evidence that deep convection over India is a significant source for ATAL through the vertical transport of pollution to the upper troposphere.

  19. The Impact of Positive Role Models on the Success of Students Involved in Original Scientific Research

    NASA Astrophysics Data System (ADS)

    Danch, J. M.

    2010-12-01

    To maximize student understanding of the methods of science via performance of authentic scientific research, a mentorship program for middle school students was developed for the 2010 - 2011 school year. A population of 8th grade science students will be selected from a district middle school and be paired with secondary student mentors already conducting individual research as part of a successful preexisting science research program. Students will interact with mentors in a school setting to develop and implement original scientific research projects. Upon completion, students will present their findings at an interscholastic science symposium and/or an in-district science symposium. Students will also receive support from professional scientists at the University of Medicine and Dentistry of New Jersey through interactive visitations and electronic communication. In an effort to provide diverse role models, mentors from a variety of racial, ethnic, and gender groups will participate. Student success will be evaluated through questionnaires, symposium participation and monitoring of future participation in authentic research programs as participants make the transition from middle to high school.

  20. Moon and Terrestrial Planets: Unresolved Questions

    NASA Astrophysics Data System (ADS)

    Schmitt, H. H.

    2002-12-01

    Human exploration during Apollo began the documentation of the evolution of the Moon and of its importance in understanding the origin and evolution of the terrestrial planets. This revolution in planetary geology continues as a vigorous and vibrant arena for discovery and debate for new generations of geoscientists. Although much has been learned and, indeed, resolved in lunar science, we are left with major questions unresolved. One fundamental question is that of the origin of the Moon. A large consensus has developed in the planetary science community that the Moon was created by the "giant impact" of a Mars-sized asteroid on the Earth after the accretion of the Earth was largely complete and differentiation had begun. A minority, however, questions this consensus hypothesis because of increasing indications that the lower mantle of the Moon may be largely undifferentiated. If the issue of the high angular momentum of the Earth-Moon system can be resolved through new modeling studies, then capture of a co-orbiting planetesimal may be an important alternative to a "giant impact". Another important question, particularly in consideration of the terrestrial and Martian surface environments during the first 0.8 billion years of Earth history, is the impact record of that period as recorded on the Moon. Again, a large consensus has developed that the 50 or so large and very large impact basins identified on the Moon were created over a very short "cataclysm" between about 3.9 and 3.8 billion years ago. Here also, a minority suggests that this period of large basin formation, although distinct in lunar history, took place over several hundred million years and that the apparent cataclysm is an artifact of sampling the effects of the last few basin-forming impacts. Either way, a previously unavailable source of impactors appeared somewhere in the solar system and greatly affected terrestrial environments at the time the precursors to life were appearing on Earth

  1. On the origins of Mendelian disease genes in man: the impact of gene duplication.

    PubMed

    Dickerson, Jonathan E; Robertson, David L

    2012-01-01

    Over 3,000 human diseases are known to be linked to heritable genetic variation, mapping to over 1,700 unique genes. Dating of the evolutionary age of these disease-associated genes has suggested that they have a tendency to be ancient, specifically coming into existence with early metazoa. The approach taken by past studies, however, assumes that the age of a disease is the same as the age of its common ancestor, ignoring the fundamental contribution of duplication events in the evolution of new genes and function. Here, we date both the common ancestor and the duplication history of known human disease-associated genes. We find that the majority of disease genes (80%) are genes that have been duplicated in their evolutionary history. Periods for which there are more disease-associated genes, for example, at the origins of bony vertebrates, are explained by the emergence of more genes at that time, and the majority of these are duplicates inferred to have arisen by whole-genome duplication. These relationships are similar for different disease types and the disease-associated gene's cellular function. This indicates that the emergence of duplication-associated diseases has been ongoing and approximately constant (relative to the retention of duplicate genes) throughout the evolution of life. This continued until approximately 390 Ma from which time relatively fewer novel genes came into existence on the human lineage, let alone disease genes. For single-copy genes associated with disease, we find that the numbers of disease genes decreases with recency. For the majority of duplicates, the disease-associated mutation is associated with just one of the duplicate copies. A universal explanation for heritable disease is, thus, that it is merely a by-product of the evolutionary process; the evolution of new genes (de novo or by duplication) results in the potential for new diseases to emerge.

  2. Impact origin of sediments at the Opportunity landing site on Mars.

    PubMed

    Knauth, L Paul; Burt, Donald M; Wohletz, Kenneth H

    2005-12-22

    Mars Exploration Rover Opportunity discovered sediments with layered structures thought to be unique to aqueous deposition and with minerals attributed to evaporation of an acidic salty sea. Remarkable iron-rich spherules were ascribed to later groundwater alteration, and the inferred abundance of water reinforced optimism that Mars was once habitable. The layered structures, however, are not unique to water deposition, and the scenario encounters difficulties in accounting for highly soluble salts admixed with less soluble salts, the lack of clay minerals from acid-rock reactions, high sphericity and near-uniform sizes of the spherules and the absence of a basin boundary. Here we present a simple alternative explanation involving deposition from a ground-hugging turbulent flow of rock fragments, salts, sulphides, brines and ice produced by meteorite impact. Subsequent weathering by intergranular water films can account for all of the features observed without invoking shallow seas, lakes or near-surface aquifers. Layered sequences observed elsewhere on heavily cratered Mars and attributed to wind, water or volcanism may well have formed similarly. If so, the search for past life on Mars should be reassessed accordingly.

  3. Potential water quality impacts originating from land burial of cattle carcasses.

    PubMed

    Yuan, Qi; Snow, Daniel D; Bartelt-Hunt, Shannon L

    2013-07-01

    Among the conventional disposal methods for livestock mortalities, on-farm burial is a preferred method, but the potential water quality impacts of animal carcass burial are not well understood. Typically, on-farm burial pits are constructed without liners and any leachate produced may infiltrate into soil and groundwater. To date, no information is available on temporal trends for contaminants in leachate produced from livestock mortality pits. In our study, we examined the concentrations of conventional contaminants including electrical conductivity, COD, TOC, TKN, TP, and solids, as well as veterinary antimicrobials and steroid hormones in leachate over a period of 20 months. Most of the contaminants were detected in leachate after 50 days of decomposition, reaching a peak concentration at approximately 200 days and declined to baseline levels by 400 days. The estrogen 17β-estradiol and a veterinary antimicrobial, monensin, were observed at maximum concentrations of 20,069 ng/L and 11,980 ng/L, respectively. Estimated mass loading of total steroid hormone and veterinary pharmaceuticals were determined to be 1.84 and 1.01 μg/kg of buried cattle carcass materials, respectively. These data indicate that leachate from carcass burial sites represents a potential source of nutrients, organics, and residues of biologically active micro-contaminants to soil and groundwater.

  4. Origin and history of chondrite regolith, fragmental and impact-melt breccias from Spain

    NASA Astrophysics Data System (ADS)

    Casanova, I.; Keil, K.; Wieler, R.; San Miguel, A.; King, E. A.

    1990-06-01

    Six ordinary chondrite breccias from the Museo Nacional de Ciencias Naturales, Madrid (Spain), are described and classified as follows: the solar gas-rich regolith breccia Oviedo (H5); the premetamorphic fragmental breccias Cabezo de Mayo (type 6, L-LL), and Sevilla (LL4); the fragmental breccias Canellas (H4) and Gerona (H5); and the impact melt breccia, Madrid (L6). It is confirmed that chondrites with typical light-dark structures and petrographic properties typical of regolith breccias may (Oviedo) or may not (Canellas) be solar gas-rich. Cabezo de Mayo and Sevilla show convincing evidence that they were assembled prior to peak metamorphism and were equilibrated during subsequent reheating. Compositions of olivine and low-Ca pyroxene in host chondrite and breccia clasts in Cabezo de Mayo are transitional between groups L and LL. It is suggested, based on mineralogic and oxygen isotopic compositions of host and clasts, that the rock formed on the L parent body by mixing, prior to peak metamorphism. This was followed by partial equilibrium of two different materials: the indigenous L chondrite host and exotic LL melt rock clasts.

  5. Origin and history of chondrite regolith, fragmental and impact-melt breccias from Spain

    NASA Technical Reports Server (NTRS)

    Casanova, I.; Keil, K.; Wieler, R.; San Miguel, A.; King, E. A.

    1990-01-01

    Six ordinary chondrite breccias from the Museo Nacional de Ciencias Naturales, Madrid (Spain), are described and classified as follows: the solar gas-rich regolith breccia Oviedo (H5); the premetamorphic fragmental breccias Cabezo de Mayo (type 6, L-LL), and Sevilla (LL4); the fragmental breccias Canellas (H4) and Gerona (H5); and the impact melt breccia, Madrid (L6). It is confirmed that chondrites with typical light-dark structures and petrographic properties typical of regolith breccias may (Oviedo) or may not (Canellas) be solar gas-rich. Cabezo de Mayo and Sevilla show convincing evidence that they were assembled prior to peak metamorphism and were equilibrated during subsequent reheating. Compositions of olivine and low-Ca pyroxene in host chondrite and breccia clasts in Cabezo de Mayo are transitional between groups L and LL. It is suggested, based on mineralogic and oxygen isotopic compositions of host and clasts, that the rock formed on the L parent body by mixing, prior to peak metamorphism. This was followed by partial equilibrium of two different materials: the indigenous L chondrite host and exotic LL melt rock clasts.

  6. Neighbour Origin and Ploidy Level Drive Impact of an Alien Invasive Plant Species in a Competitive Environment.

    PubMed

    Sun, Yan; Müller-Schärer, Heinz; Schaffner, Urs

    2016-01-01

    Our understanding of the potential mechanisms driving the spread and naturalization of alien plant species has increased over the past decades, but specific knowledge on the factors contributing to their increased impact in the introduced range is still urgently needed. The native European plant Centaurea stoebe occurs as two cytotypes with different life histories (monocarpic diploids, allo-polycarpic tetraploids). However, only tetraploids have been found in its introduced range in North America, where C. stoebe has become a most prominent plant invader. Here, we focus on the ploidy level of C. stoebe and origin of neighbouring community in explaining the high impact during the invasion of new sites in the introduced range. We conducted a mesocosm experiment under open-field conditions with the diploid (EU2x) and tetraploid (EU4x) cytotype of Centaurea stoebe from its native European (EU) range, and with the invasive tetraploid (NA4x) cytotype from the introduced North American (NA) range in competition with EU (old) or NA (new) neighbouring plant communities. In the presence of competition, the biomass of EU neighbouring community was reduced to a comparable level by all three geo-cytotypes of C. stoebe. In contrast, the biomass of the NA neighbouring community was reduced beyond when competing with tetraploid, but not with diploid C. stoebe. The fact that the biomass of all three geo-cytotypes of C. stoebe was correlated with the biomass of the EU neighbouring community, but not with that of the NA neighbouring community suggests that different mechanisms underlie the competitive interactions between C. stoebe and its old vs. new neighbouring communities, such as competition for the same limiting resources at home vs competition through novel allelo-chemicals or differential resource uptake strategies in the introduced range. We therefore caution to simply use the ecosystem impact assessed at home to predict impact in the introduced range.

  7. Neighbour Origin and Ploidy Level Drive Impact of an Alien Invasive Plant Species in a Competitive Environment

    PubMed Central

    Sun, Yan; Müller-Schärer, Heinz; Schaffner, Urs

    2016-01-01

    Our understanding of the potential mechanisms driving the spread and naturalization of alien plant species has increased over the past decades, but specific knowledge on the factors contributing to their increased impact in the introduced range is still urgently needed. The native European plant Centaurea stoebe occurs as two cytotypes with different life histories (monocarpic diploids, allo-polycarpic tetraploids). However, only tetraploids have been found in its introduced range in North America, where C. stoebe has become a most prominent plant invader. Here, we focus on the ploidy level of C. stoebe and origin of neighbouring community in explaining the high impact during the invasion of new sites in the introduced range. We conducted a mesocosm experiment under open-field conditions with the diploid (EU2x) and tetraploid (EU4x) cytotype of Centaurea stoebe from its native European (EU) range, and with the invasive tetraploid (NA4x) cytotype from the introduced North American (NA) range in competition with EU (old) or NA (new) neighbouring plant communities. In the presence of competition, the biomass of EU neighbouring community was reduced to a comparable level by all three geo-cytotypes of C. stoebe. In contrast, the biomass of the NA neighbouring community was reduced beyond when competing with tetraploid, but not with diploid C. stoebe. The fact that the biomass of all three geo-cytotypes of C. stoebe was correlated with the biomass of the EU neighbouring community, but not with that of the NA neighbouring community suggests that different mechanisms underlie the competitive interactions between C. stoebe and its old vs. new neighbouring communities, such as competition for the same limiting resources at home vs competition through novel allelo-chemicals or differential resource uptake strategies in the introduced range. We therefore caution to simply use the ecosystem impact assessed at home to predict impact in the introduced range. PMID:27203687

  8. Dust Infall Onto Phobos and Deimos Can Explain Their Carbonaceous Reflectance Signature, Perhaps Overlying a Mars-Impact-Origin Core: A Hypothesis

    NASA Technical Reports Server (NTRS)

    Fries, M.; Cintala, M.; Steele, A.; Welzenbach, L. C.

    2017-01-01

    Discussions of Phobos' and Deimos' (henceforth P&D) origin(s) include an unresolved conflict: dynamical studies which favor coalescence of the moons from a large impact on Mars [1,2], versus reflectance spectroscopy of the moons showing a carbonaceous composition that is not consistent with martian surface materials [3-5]. One way to reconcile this discrepancy is to consider the combined options of a Mars impact origin for Phobos and Deimos, followed by deposition of carbon-rich materials by interplanetary dust particle (IDP) infall. This is significant because, unlike asteroidal bodies, P&D experience a high IDP flux due to their location in Mars' gravity well. We present some relatively simple, initial calculations which indicate that accreted carbon may be sufficient to produce a surface with sufficient added carbon to account for P&D's reflectance spectra. If this is true, then a major objection to an impact origin for P&D is resolved.

  9. Carbonates in fractures of Martian meteorite Allan Hills 84001: petrologic evidence for impact origin

    NASA Technical Reports Server (NTRS)

    Scott, E. R.; Krot, A. N.; Yamaguchi, A.

    1998-01-01

    Carbonates in Martian meteorite Allan Hills 84001 occur as grains on pyroxene grain boundaries, in crushed zones, and as disks, veins, and irregularly shaped grains in healed pyroxene fractures. Some carbonate disks have tapered Mg-rich edges and are accompanied by smaller, thinner and relatively homogeneous, magnesite microdisks. Except for the microdisks, all types of carbonate grains show the same unique chemical zoning pattern on MgCO3-FeCO3-CaCO3 plots. This chemical characteristic and the close spatial association of diverse carbonate types show that all carbonates formed by a similar process. The heterogeneous distribution of carbonates in fractures, tapered shapes of some disks, and the localized occurrence of Mg-rich microdisks appear to be incompatible with growth from an externally derived CO2-rich fluid that changed in composition over time. These features suggest instead that the fractures were closed as carbonates grew from an internally derived fluid and that the microdisks formed from a residual Mg-rich fluid that was squeezed along fractures. Carbonate in pyroxene fractures is most abundant near grains of plagioclase glass that are located on pyroxene grain boundaries and commonly contain major or minor amounts of carbonate. We infer that carbonates in fractures formed from grain boundary carbonates associated with plagiociase that were melted by impact and dispersed into the surrounding fractured pyroxene. Carbonates in fractures, which include those studied by McKay et al. (1996), could not have formed at low temperatures and preserved mineralogical evidence for Martian organisms.

  10. An original experiment to determine impact of catch crop introduction in a crop rotation on N2O production fate

    NASA Astrophysics Data System (ADS)

    Tallec, Tiphaine; Le Dantec, Valérie; Zawilski, Bartosz; Brut, Aurore; Boussac, Marion; Ferlicoq, Morgan; Ceschia, Eric

    2015-04-01

    The raise in N2O concentration from the preindustrial era (280 ppb) to nowadays (324 ppb) is estimated to account for approximately 6% of the predicted global warming (IPCC 2014). Worldwide, soils are considered to be the dominant source of N2O, releasing an estimated 9.5 Tg N2O-N y-1 (65% of global N2O emissions), of which 36.8% are estimated to originate from agricultural soils (IPCC 2001). Most N2O originating from agricultural soils is a by- or end-product of nitrification or denitrification. The fate of N2O produced by microbiological processes in the subsoil is controlled by biotic (crop species, occurring soil organic matter, human pressure via mineral and organic nitrogen fertilisation) and abiotic (environmental conditions such as temperature, soil moisture, pH, etc.) factors. In cropland, contrary to forest and grassland, long bare soil periods can occurred between winter and summer crops with a high level of mineral (fertilizer) and organic (residues) nitrogen remaining in the soil, causing important emissions of carbon and nitrogen induced by microbial activities. Introduction of catch crop has been identified as an important mitigation option to reduce environmental impact of crops mainly thanks to their ability to increase CO2 fixation, to decrease mineral nitrogen lixiviation and also reduce the potential fate of N2O production. Uncertainty also remains about the impact of released mineral nitrogen coming from crushed catch crop on N2O production if summer crop seedling and mineral nitrogen release are not well synchronized. To verify those assumptions, a unique paired-plot experiment was carried in the south-west of France from September 2013 to august 2014 to test impact of management change on N2O budget and production dynamic. A crop plot was divided into two subplots, one receiving a catch crop (mustard), the other one remaining conventionally managed (bare-soil during winter). This set-up allowed avoiding climate effect. Each subplot was

  11. MinUrals: Mineral resources of the Urals -- origin, development, and environmental impact

    NASA Astrophysics Data System (ADS)

    Leistel, J. M.; Minurals Team

    2003-04-01

    The MinUrals project (supported by the European Commission under the 5th F.P.- INCO2 - contract ICA2-CT-2000-10011) is focusing on the South Urals mining sector, in order to improve local socio-economic conditions, through: 1) The reinterpretation of the geodynamics of South Urals and of the different types of ore deposits and the development of tools for mineral exploration (new geophysical and geochemical technology). The convergence setting and the formation of arc, fore-arc and back-arc systems explain the volcano-sedimentary and structural features. This geodynamic setting largely controls the distribution and characteristics of the different types of mineralisation; 2) The evaluation of local mining-related risks to the environment, with a development of methodologies for assessing and reducing the environmental impact and localizing areas of high metal potential/low environmental constraints. Three pilote sites were investigated: Sibay and Uchaly (with mining installations), and Karabash (with mining installations and smelter); 3) The implementation of a Geographical Information System taking into account the mineral potential and the environmental constraints that, through data ranking and combining the key parameters of the areas with high metal potential and environmental constraints, will enable the production of a Mineral Potential and Environmental Constraints Map of the South Urals; 4) The elaboration of recommendations for a suitable environmentally-aware mining-industry legislation, based on a comparison with the European legislation, to be adressed to the Commission on the demarcation of powers and subjects between the federal government, governments of the subjects of the Russian Federation and local authorities. More information can be found on the project web sites [http://minurals.brgm.fr] or [http://www.nhm.ac.uk/mineralogy/minurals/minurals.htm] or [http://www.anrb.ru/geol/MinUrals] or [http://minurals.ilmeny.ac.ru] MinUrals Team (*): Aug

  12. Origins of a 350-kilobase genomic duplication in Mycobacterium tuberculosis and its impact on virulence.

    PubMed

    Domenech, Pilar; Rog, Anya; Moolji, Jalal-ud-din; Radomski, Nicolas; Fallow, Ashley; Leon-Solis, Lizbel; Bowes, Julia; Behr, Marcel A; Reed, Michael B

    2014-07-01

    In the present study, we have investigated the evolution and impact on virulence of a 350-kb genomic duplication present in the most recently evolved members of the Mycobacterium tuberculosis East Asian lineage. In a mouse model of infection, comparing HN878 subclones HN878-27 (no duplication) and HN878-45 (with the 350-kb duplication) revealed that the latter is impaired for in vivo growth during the initial 3 weeks of infection. Furthermore, the median survival time of mice infected with isolate HN878-45 is significantly longer (77 days) than that of mice infected with HN878-27. Whole-genome sequencing of both isolates failed to reveal any mutational events other than the duplication that could account for such a substantial difference in virulence. Although we and others had previously speculated that the 350-kb duplication arose in response to some form of host-applied selective pressure (P. Domenech, G. S. Kolly, L. Leon-Solis, A. Fallow, M. B. Reed, J. Bacteriol. 192: 4562-4570, 2010, and B. Weiner, J. Gomez, T. C. Victor, R. M. Warren, A. Sloutsky, B. B. Plikaytis, J. E. Posey, P. D. van Helden, N. C. Gey van Pittius, M. Koehrsen, P. Sisk, C. Stolte, J. White, S. Gagneux, B. Birren, D. Hung, M. Murray, J. Galagan, PLoS One 7: e26038, 2012), here we show that this large chromosomal amplification event is very rapidly selected within standard in vitro broth cultures in a range of isolates. Indeed, subclones harboring the duplication were detectable after just five rounds of in vitro passage. In contrast, the duplication appears to be highly unstable in vivo and is negatively selected during the later stages of infection in mice. We believe that the rapid in vitro evolution of M. tuberculosis is an underappreciated aspect of its biology that is often ignored, despite the fact that it has the potential to confound the data and conclusions arising from comparative studies of isolates at both the genotypic and phenotypic levels.

  13. Posing Einstein's Question: Questioning Einstein's Pose.

    ERIC Educational Resources Information Center

    Topper, David; Vincent, Dwight E.

    2000-01-01

    Discusses the events surrounding a famous picture of Albert Einstein in which he poses near a blackboard containing a tensor form of his 10 field equations for pure gravity with a question mark after it. Speculates as to the content of Einstein's lecture and the questions he might have had about the equation. (Contains over 30 references.) (WRM)

  14. Ask Questions to Encourage Questions Asked

    ERIC Educational Resources Information Center

    belcastro, sarah-marie

    2017-01-01

    We delineate some types of structured practice (modeling, requests, feedback, and space-making) that help students learn to pose appropriate questions and to initiate exploration of those questions. Developing skills requires practice, so we suggest ways to embed structured practice into existing class sessions. Including structured practice is…

  15. Evaluating the Long-Term Health and Economic Impacts of Central Residential Air Filtration for Reducing Premature Mortality Associated with Indoor Fine Particulate Matter (PM2.5) of Outdoor Origin.

    PubMed

    Zhao, Dan; Azimi, Parham; Stephens, Brent

    2015-07-21

    Much of human exposure to fine particulate matter (PM2.5) of outdoor origin occurs in residences. High-efficiency particle air filtration in central heating, ventilating, and air-conditioning (HVAC) systems is increasingly being used to reduce concentrations of particulate matter inside homes. However, questions remain about the effectiveness of filtration for reducing exposures to PM2.5 of outdoor origin and adverse health outcomes. Here we integrate epidemiology functions and mass balance modeling to estimate the long-term health and economic impacts of HVAC filtration for reducing premature mortality associated with indoor PM2.5 of outdoor origin in residences. We evaluate 11 classifications of filters (MERV 5 through HEPA) using six case studies of single-family home vintages and ventilation system combinations located in 22 U.S. cities. We estimate that widespread use of higher efficiency filters would reduce premature mortality by 0.002-2.5% and increase life expectancy by 0.02-1.6 months, yielding annual monetary benefits ranging from $1 to $1348 per person in the homes and locations modeled herein. Large differences in the magnitude of health and economic impacts are driven largely by differences in rated filter efficiency and building and ventilation system characteristics that govern particle infiltration and persistence, with smaller influences attributable to geographic location.

  16. Evaluating the Long-Term Health and Economic Impacts of Central Residential Air Filtration for Reducing Premature Mortality Associated with Indoor Fine Particulate Matter (PM2.5) of Outdoor Origin

    PubMed Central

    Zhao, Dan; Azimi, Parham; Stephens, Brent

    2015-01-01

    Much of human exposure to fine particulate matter (PM2.5) of outdoor origin occurs in residences. High-efficiency particle air filtration in central heating, ventilating, and air-conditioning (HVAC) systems is increasingly being used to reduce concentrations of particulate matter inside homes. However, questions remain about the effectiveness of filtration for reducing exposures to PM2.5 of outdoor origin and adverse health outcomes. Here we integrate epidemiology functions and mass balance modeling to estimate the long-term health and economic impacts of HVAC filtration for reducing premature mortality associated with indoor PM2.5 of outdoor origin in residences. We evaluate 11 classifications of filters (MERV 5 through HEPA) using six case studies of single-family home vintages and ventilation system combinations located in 22 U.S. cities. We estimate that widespread use of higher efficiency filters would reduce premature mortality by 0.002–2.5% and increase life expectancy by 0.02–1.6 months, yielding annual monetary benefits ranging from $1 to $1348 per person in the homes and locations modeled herein. Large differences in the magnitude of health and economic impacts are driven largely by differences in rated filter efficiency and building and ventilation system characteristics that govern particle infiltration and persistence, with smaller influences attributable to geographic location. PMID:26197328

  17. Who Asks the Questions?

    ERIC Educational Resources Information Center

    Hervey, Sheena

    2006-01-01

    From a very young age, children actively strive to make sense of their world through constant questioning. The ability to ask questions comes naturally for young children, but such natural inclination does not continue because it teachers who ask most of the questions. Sheena Hervey suggests that teaching students how to pose questions is a…

  18. Revisiting Routine Questions

    ERIC Educational Resources Information Center

    Hughes, Rebecca; Monaghan, John; Shingadia, Eisha; Vaughan, Stephen

    2006-01-01

    What is a routine question? The focus of this paper is routine questions and time (in years) since a hitherto routine question was last attempted by the solver. The data comes from undergraduate students' work on solving two calculus questions. The data was selected for reporting purposes because it is well documented and because it threw up…

  19. Questions of Chemistry.

    ERIC Educational Resources Information Center

    Pedrosa de Jesus, Helena; Teixeira-Dias, Jose J. C.; Watts, Mike

    2003-01-01

    Documents the use of student-generated questions as diagnostic of their willingness to engage in classroom interactions. Explores four ways of gathering students' written questions and their relative effectiveness. Examines students' capacity to design and present 'quality questions' and the extent to which these questions are indicative of…

  20. Gay-Straight Alliances: Understanding Their Impact on the Academic and Social Experiences of Lesbian, Gay, Bisexual, Transgender, and Questioning High School Students

    ERIC Educational Resources Information Center

    McCormick, Adam; Schmidt, Kathryn; Clifton, Emily

    2015-01-01

    Few studies have examined the effectiveness of gay-straight alliances (GSAs) on the social and academic experiences of lesbian, gay, bisexual, transgender, and questioning (LGBTQ) youths. The limited research on GSAs suggests that they are associated with positive youth development and increased safety; however, little qualitative information…

  1. Questioning the Role of Internationalization in the Nationalization of Higher Education: The Impact of the EU TEMPUS Programme on Higher Education in Syria

    ERIC Educational Resources Information Center

    Ayoubi, Rami M.; Massoud, Hiba K.

    2011-01-01

    Given the need for major reform of the higher education programmes in Syria, and answering the voices that question the role of European Union (EU) in assisting the development of the higher education sector, this study presents an analysis of the contribution of (TEMPUS) Programme in modernising higher education in Syria. The study compares the…

  2. Question analysis for Indonesian comparative question

    NASA Astrophysics Data System (ADS)

    Saelan, A.; Purwarianti, A.; Widyantoro, D. H.

    2017-01-01

    Information seeking is one of human needs today. Comparing things using search engine surely take more times than search only one thing. In this paper, we analyzed comparative questions for comparative question answering system. Comparative question is a question that comparing two or more entities. We grouped comparative questions into 5 types: selection between mentioned entities, selection between unmentioned entities, selection between any entity, comparison, and yes or no question. Then we extracted 4 types of information from comparative questions: entity, aspect, comparison, and constraint. We built classifiers for classification task and information extraction task. Features used for classification task are bag of words, whether for information extraction, we used lexical, 2 previous and following words lexical, and previous label as features. We tried 2 scenarios: classification first and extraction first. For classification first, we used classification result as a feature for extraction. Otherwise, for extraction first, we used extraction result as features for classification. We found that the result would be better if we do extraction first before classification. For the extraction task, classification using SMO gave the best result (88.78%), while for classification, it is better to use naïve bayes (82.35%).

  3. Samples from Martian craters: Origin of the Martian soil by hydrothermal alteration of impact melt deposits and atmospheric interactions with ejecta during crater formation

    NASA Technical Reports Server (NTRS)

    Newsom, Horton E.

    1988-01-01

    The origin of the Martian soil is an important question for understanding weathering processes on the Martian surface, and also for understanding the global geochemistry of Mars. Chemical analyses of the soil will provide an opportunity to examine what may be a crustal average, as studies of loess on the Earth have demonstrated. In this regard the origin of the Martian soil is also important for understanding the chemical fractionations that have affected the composition of the soil. Several processes that are likely to contribute to the Martian soil are examined.

  4. Anomalous Enstatite Meteorites Queen Alexandra Range 94204 and Pairs: The Perplexing Question of Impact Melts or Partial Melt Residues, Either way, Unrelated to Yamato 793225

    NASA Astrophysics Data System (ADS)

    van Niekerk, D.; Keil, K.

    2012-03-01

    QUE 94204 and its seven pairs are anomalous enstatite meteorites that may either be impact melt products, or partial melt residues. We explore the petrology of these meteorites and present new findings.

  5. Endogenous production, exogenous delivery and impact-shock synthesis of organic molecules: an inventory for the origins of life.

    PubMed

    Chyba, C; Sagan, C

    1992-01-09

    Sources of organic molecules on the early Earth divide into three categories: delivery by extraterrestrial objects; organic synthesis driven by impact shocks; and organic synthesis by other energy sources (such as ultraviolet light or electrical discharges). Estimates of these sources for plausible end-member oxidation states of the early terrestrial atmosphere suggest that the heavy bombardment before 3.5 Gyr ago either produced or delivered quantities of organics comparable to those produced by other energy sources. Which sources of prebiotic organics were quantitatively dominant depends strongly on the composition of the early terrestrial atmosphere. In the event of an early strongly reducing atmosphere, production by atmospheric shocks seems to have dominated that due to electrical discharges. Organic synthesis by ultraviolet light may, in turn, have dominated shock production, but only if a long-wavelength absorber such as H2S were supplied to the atmosphere at a rate sufficient for synthesis to have been limited by ultraviolet flux, rather than by reactant abundance. In the apparently more likely case of an early terrestrial atmosphere of intermediate oxidation state, atmospheric shocks were probably of little importance for direct organic production. For [H2]/[CO2] ratios of approximately 0.1, net organic production was some three orders of magnitude lower than for reducing atmospheres, with delivery of intact exogenous organics in interplanetary dust particles (IDPs) and ultraviolet production being the most important sources. At still lower [H2]/[CO2] ratios, IDPs may have been the dominant source of prebiotic organics on the early Earth. Endogenous, exogenous and impact-shock sources of organics could each have made a significant contribution to the origins of life.

  6. Exam Question Exchange.

    ERIC Educational Resources Information Center

    Alexander, John J.

    1979-01-01

    Describes an exam question which challenges college freshmen, enrolled in chemistry, to derive temperature dependence of an equilibrium constant. The question requires cognitive response at the level of synthesis. (Author/SA)

  7. Burning Questions about Calories.

    ERIC Educational Resources Information Center

    Keller, J. David; Berry, Kimberly A.

    2001-01-01

    Uses questioning techniques to teach about caloric consumption and weight gain. Starts with defining questions about calories and includes the stages of measuring calories, analyzing data, and conducting inquiry research. Includes directions for the experiment. (YDS)

  8. Pesticide Labeling Questions & Answers

    EPA Pesticide Factsheets

    Pesticide manufacturers, applicators, state regulatory agencies, and other stakeholders raise questions or issues about pesticide labels. The questions on this page are those that apply to multiple products or address inconsistencies among product labels.

  9. Questions in Reference Interviews.

    ERIC Educational Resources Information Center

    White, Marilyn Domas

    1998-01-01

    Characterizes the questioning behavior in reference interviews preceding delegated online searches of bibliographic databases and relates it to questioning behavior in other types of interviews/settings. Compares questions asked by the information specialist and those asked by the client; findings show the information specialist dominates the…

  10. Exam Question Exchange.

    ERIC Educational Resources Information Center

    Alexander, John J., Ed.

    1987-01-01

    Contains two articles relating to chemistry examination questions. One provides examples of how to sequence multiple choice questions so that partial credit may be given for some responses. The second includes a question and solution dealing with stereoisomerism as a result of free radical chlorination of a nonstereoisometic substance. (TW)

  11. Exam Question Exchange.

    ERIC Educational Resources Information Center

    Alexander, John J., Ed.

    1983-01-01

    Acceptable answers are provided for two chemistry questions. The first question is related to the prediction of the appearance of non-first-order proton nuclear magnetic resonance (NMR) spectra. The second question is related to extraterrestrial kinetic theory of gases. (JN)

  12. Listening and Questioning

    ERIC Educational Resources Information Center

    Haroutunian-Gordon, Sophie

    2007-01-01

    In the article that follows, I take up a debate that has arisen over the past three years concerning the following issue: Does every act of listening involve the listener in questioning? I argue that the answer to the questions is yes. I give background on the question and then consider one instance of listening that may suggest no role for…

  13. Making Questions Flow

    ERIC Educational Resources Information Center

    Rothstein, Dan; Santana, Luz; Minigan, Andrew P.

    2015-01-01

    Getting students to ask questions can feel like pulling teeth. How can teachers transform that feeling and create classrooms that come alive with questions? The authors, developers of the question formulation technique, suggest two simple changes: First, teachers need to give students both a structure and the opportunity to practice generating…

  14. Improving Student Question Classification

    ERIC Educational Resources Information Center

    Heiner, Cecily; Zachary, Joseph L.

    2009-01-01

    Students in introductory programming classes often articulate their questions and information needs incompletely. Consequently, the automatic classification of student questions to provide automated tutorial responses is a challenging problem. This paper analyzes 411 questions from an introductory Java programming course by reducing the natural…

  15. Does the sedimentology of the Chelmsford formation provide evidence for a meteorite impact origin of the Sudbury structure?

    NASA Technical Reports Server (NTRS)

    Long, D. G. F.

    1992-01-01

    The post-'event' fill of the Paleoproterozoic Sudbury Basin consists of at least 600 m of deep-water mudrocks of the Onwatin Formation, overlain by 850 m of lithic-arkosic muddy sandstones in the Chelmsford Formation. While mudstones of the Onwatin reflect deposition in a deep-water, anoxic setting, there is no clear evidence of local breccias, conglomerates, or sand bodies to support the concept that the basin was protected by the steep walls of an impact crater. Carbonates in the basal, Vermillion Member are of sedimentary exhalitive origin and were not derived from a shallow marine shelf. Turbidites in the Chelmsford Formation show no evidence of centripetal fill as might be expected from a restricted, circular basin. They appear to have been emplaced by predominantly southwesterly flowing turbidity currents, which showed little to no deflection along the depositional axis of an elongate foreland basin that developed in front of the rising Penokean mountain chain. While the presence of minor sandstone-filled fractures in parts of the Chelmsford Formation suggests the presence of north- or south-directed paleoslopes, no evidence is seen to support the existence of subbasins or a central uplift within the Sudbury Basin. While tilt-corrected paleocurrent orientations are ambiguous, due to postdepositional shortening of strata during cleavage development, strain correction of the observations makes little difference to the net, south-southwest-directed paleoflow.

  16. Impact of heating on sensory properties of French Protected Designation of Origin (PDO) blue cheeses. Relationships with physicochemical parameters.

    PubMed

    Bord, Cécile; Guerinon, Delphine; Lebecque, Annick

    2016-07-01

    The aim of this study was to measure the impact of heating on the sensory properties of blue-veined cheeses in order to characterise their sensory properties and to identify their specific sensory typology associated with physicochemical parameters. Sensory profiles were performed on a selection of Protected Designation of Origin (PDO) cheeses representing the four blue-veined cheese categories produced in the Massif Central (Fourme d'Ambert, Fourme de Montbrison, Bleu d'Auvergne and Bleu des Causses). At the same time, physicochemical parameters were measured in these cheeses. The relationship between these two sets of data was investigated. Four types of blue-veined cheeses displayed significantly different behaviour after heating and it is possible to discriminate these cheese categories through specific sensory attributes. Fourme d'Ambert and Bleu d'Auvergne exhibited useful culinary properties: they presented good meltability, stretchability and a weak oiling-off. However, basic tastes (salty, bitter and sour) are also sensory attributes which can distinguish heated blue cheeses. The relationship between the sensory and physicochemical data indicated a correlation suggesting that some of these sensory properties may be explained by certain physicochemical parameters of heated cheeses.

  17. [Ethical questions in neonatology].

    PubMed

    Popow, C

    1996-01-01

    Rapid scientific progress in the fields of prenatal diagnostics, obstetrics and neonatology has enabled severe malformations and hereditary diseases to be detected at a very early fetal stage and has also led to the survival of very immature newborn infants in increasing numbers. Parents, doctors and nurses must all participate in the difficult decision making with regard to therapeutic alternatives and due respect must be paid to the intersects of the child, the impact on the family, but also to the professional opinion of the attending doctors and carers. Problems of the ethical limits of prenatal diagnostics, as well as the severity of malformations or organ failure justifying termination of pregnancy or intensive care measures are discussed with reference to clinical cases. Likewise, the question of precedence of the rights of the parents and siblings to quality of life versus the right of the infant to live is broached. From the neonatological point of view candid discussion with the parents, painstaking efforts to build up an atmosphere of confidence and the provision of supportive measures on the one hand, whilst avoiding the expression of dogmatic opinions and patronizing attitudes on the other hand, are essential prerequisites in dealing with the ethical dilemmas arising in the pre- and neonatal management of such cases.

  18. Research-Based Responses to Key Questions about the 2010 Head Start Impact Study. Early Childhood Highlights. Volume 2, Issue 1

    ERIC Educational Resources Information Center

    Child Trends, 2011

    2011-01-01

    Since 1965, Head Start has provided comprehensive services to help prepare the nation's most disadvantaged three- to five-year-old children for school and to strengthen their families. In 1998 Congress instructed the Department of Health and Human Services (DHHS) to conduct an evaluation of Head Start to determine its impact on child development…

  19. Measuring Victimization inside Prisons: Questioning the Questions

    ERIC Educational Resources Information Center

    Wolff, Nancy; Shi, Jing; Bachman, Ronet

    2008-01-01

    Violence and victimization inside the prison setting are accepted as facts, although the facts about their prevalence remain uncertain. Variation in the methods used to estimate rates of sexual and physical victimization contribute to the wide range in estimates appearing in the prison literature. This article focuses on the questions used in the…

  20. Question-Asking and Question-Exploring

    ERIC Educational Resources Information Center

    Sands, Lorraine; Carr, Margaret; Lee, Wendy

    2012-01-01

    The Centre of Innovation Research at Greerton Early Childhood Centre was characterised as a dispositional milieu where working theories were explored through a narrative research methodology. As the research progressed, the teachers at Greerton strengthened the way we were listening to, and watching out for young children's questions to enable…

  1. Asking questions with focus

    NASA Astrophysics Data System (ADS)

    Liu, Fang; Xu, Yi

    2004-05-01

    This study investigates how different interrogative meanings interact with focus in determining the overall F0 profile of a question. We recorded eight native speakers of Mandarin producing statements, yes-no questions with and without a question particle, wh questions, incredulous questions, and confirmation questions. In each sentence, either the initial, medial, final, or no word was focused. The tonal components of the sentences are all high, all rising, all low, or all falling. F0 contours were extracted by measuring every complete vocal period in the initial, medial, and final disyllabic words in each sentence. Preliminary results show that in both statements and questions, the pitch range of the focused words is expanded and that of the postfocus words suppressed (compressed and lowered). However, postfocus pitch-range suppression seems less extensive in questions than in statements, and in some question types than in others. Finally, an extra F0 rise is often observed in the final syllable of a question unless the syllable is the question particle which has the neutral tone. This is indicative of a high or rising boundary tone associated with the interrogative meaning, which seems to be superimposed on the tone of the sentence-final syllable. [Work supported by NIDCD DC03902.

  2. Beginning EFL Teachers' Beliefs about Quality Questions and Their Questioning Practices

    ERIC Educational Resources Information Center

    Pham, Ly Ngoc Khanh; Hamid, M. Obaidul

    2013-01-01

    Motivated by the scarcity of research that examines the impact of teacher beliefs on their actual practices in Vietnam, this study investigated the relationship between teachers' beliefs about quality questions and their questioning behaviours in terms of questioning purposes, content focus, students' cognitive level, wording and syntax. Thirteen…

  3. IMPACT REGIMES AND POST-FORMATION SEQUESTRATION PROCESSES: IMPLICATIONS FOR THE ORIGIN OF HEAVY NOBLE GASES IN TERRESTRIAL PLANETS

    SciTech Connect

    Mousis, Olivier; Petit, Jean-Marc; Picaud, Sylvain; Thomas, Caroline; Schmitt, Bernard

    2010-05-10

    The difference between the measured atmospheric abundances of neon, argon, krypton, and xenon for Venus, Earth, and Mars is striking. Because these abundances drop by at least 2 orders of magnitude as one moves outward from Venus to Mars, the study of the origin of this discrepancy is a key issue that must be explained if we are to fully understand the different delivery mechanisms of the volatiles accreted by the terrestrial planets. In this work, we aim to investigate whether it is possible to quantitatively explain the variation of the heavy noble gas abundances measured on Venus, Earth, and Mars, assuming that cometary bombardment was the main delivery mechanism of these noble gases to the terrestrial planets. To do so, we use recent dynamical simulations that allow the study of the impact fluxes of comets upon the terrestrial planets during the course of their formation and evolution. Assuming that the mass of noble gases delivered by comets is proportional to the rate at which they collide with the terrestrial planets, we show that the krypton and xenon abundances in Venus and Earth can be explained in a manner consistent with the hypothesis of cometary bombardment. In order to explain the krypton and xenon abundance differences between Earth and Mars, we need to invoke the presence of large amounts of CO{sub 2}-dominated clathrates in the Martian soil that would have efficiently sequestered these noble gases. Two different scenarios based on our model can also be used to explain the differences between the neon and argon abundances of the terrestrial planets. In the first scenario, cometary bombardment of these planets would have occurred at epochs contemporary with the existence of their primary atmospheres. Comets would have been the carriers of argon, krypton, and xenon, while neon would have been gravitationally captured by the terrestrial planets. In the second scenario, we consider impacting comets that contained significantly smaller amounts of argon

  4. Discovery of microscopic evidence for shock metamorphism at the Serpent Mound structure, south-central Ohio: Confirmation of an origin by impact

    USGS Publications Warehouse

    Carlton, R.W.; Koeberl, C.; Baranoski, M.T.; SchuMacHer, G.A.

    1998-01-01

    The origin of the Serpent Mound structure in south-central Ohio has been disputed for many years. Clearly, more evidence was needed to resolve the confusion concerning the origin of the Serpent Mound feature either by endogenic processes or by hypervelocity impact. A petrographic study of 21 samples taken from a core 903 m long drilled in the central uplift of the structure provides evidence of shock metamorphism in the form of multiple sets of planar deformation features in quartz grains, as well as the presence of clasts of altered impact-melt rock. Crystallographic orientations of the planar deformation features show maxima at the shock-characteristic planes of {101??3} and {101??2} and additional maxima at {101??1}, {213??1}, and {516??1}. Geochemical analyses of impact breccias show minor enrichments in the abundances of the siderophile elements Cr, Co, Ni, and Ir, indicating the presence of a minor meteoritic component.

  5. Impact of growth hormone replacement therapy on sleep in adult patients with growth hormone deficiency of pituitary origin

    PubMed Central

    Morselli, Lisa L.; Nedeltcheva, Arlet; Leproult, Rachel; Spiegel, Karine; Martino, Enio; Legros, Jean-Jacques; Weiss, Roy E.; Mockel, Jean; Van Cauter, Eve; Copinschi, Georges

    2013-01-01

    Objectives We previously reported that adult patients with GH deficiency (GHD) due to a confirmed or likely pituitary defect, as compared to healthy controls individually matched for age, gender and BMI, have more slow-wave sleep (SWS) and higher delta activity (a marker of SWS intensity). Here we examined the impact of recombinant human GH (rhGH) therapy, compared to placebo, on objective sleep quality in a subset of patients from the same cohort. Design Single-blind randomized cross-over design study. Methods Fourteen patients with untreated GHD of confirmed or likely pituitary origin, aged 22–74 yr, participated in the study. Patients with associated hormonal deficiencies were on appropriate replacement therapy. Polygraphic sleep recordings, with bedtimes individually tailored to habitual sleep times, were performed after 4 months on rhGH or placebo. Results Valid data were obtained in 13 patients. At the end of rhGH treatment period, patients had a shorter sleep period time than at the end of the placebo period (479±11 vs 431±19 min respectively; p=0.005), primarily due to an earlier wake up time, and a decrease in the intensity of SWS (delta activity) (559±125 vs 794±219 μV2, respectively; p=0.048). Conclusions Four months of rhGH replacement therapy partly reversed sleep disturbances previously observed in untreated patients. The decrease in delta activity associated with rhGH treatment adds further evidence to the hypothesis that the excess of high intensity SWS observed in untreated pituitary GHD patients is likely to result from overactivity of the hypothalamic GHRH system due to the lack of negative feedback inhibition by GH. PMID:23447518

  6. Unpark Those Questions

    ERIC Educational Resources Information Center

    Ness, Molly

    2013-01-01

    Whenever Mr. Henderson's 3rd grade students had a question that he couldn't immediately answer or that seemed off-topic, he asked them to write the question on a sticky note and place it on a poster dubbed the "Parking Lot." His intention was to find time later to answer those questions, but too often, he said, the parking lot…

  7. Risk Factor Analysis and the Youth Question

    ERIC Educational Resources Information Center

    France, Alan

    2008-01-01

    This paper is concerned with exploring how in late modernity the "youth question" is being addressed by public policy and what impact this is having on understandings of childhood and youth. Historically the youth question has been shaped by adult anxieties over youth delinquency and their problems of social integration. In late modernity, this is…

  8. 1 Great Question

    ERIC Educational Resources Information Center

    Nethery, Carrie

    2011-01-01

    In this article, the author presents an ideal question that can take an art teacher and his or her students through all the levels of thought in Bloom's taxonomy--perfect for modeling the think-aloud process: "How many people is the artist inviting into this picture?" This great question always helps the students look beyond the obvious and dig…

  9. Let's Switch Questioning Around

    ERIC Educational Resources Information Center

    Tovani, Cris

    2015-01-01

    English teacher Cris Tovani knows from her experiences teaching elementary school that students are naturally curious. But, too often, students are so trained to be question answerers that by the time they reach high school, they no longer form questions of their own and instead focus on trying to figure out what answer the teacher wants. Tovani…

  10. Questions About the Oceans.

    ERIC Educational Resources Information Center

    Dubach, Harold W.; Taber, Robert W.

    This book was prompted by the success of a display mounted by the National Oceanographic Data Center at the 17th International Science Fair in 1966, which enabled visiting teachers and students to ask and receive answers to questions via teletype. The book contains one hundred questions typical of those asked, together with answers ranging in…

  11. Designing Great Hinge Questions

    ERIC Educational Resources Information Center

    Wiliam, Dylan

    2015-01-01

    According to author Dylan Wiliam, because lessons never go exactly as planned, teachers should build plan B into plan A. This involves designing a lesson with a "hinge" somewhere in the middle and using specific kinds of questions--what he calls hinge questions--to quickly assess students' understanding of a concept before moving on.…

  12. Problem of Questioning

    SciTech Connect

    2005-10-31

    Le Prof.Leprince-Ringuet, chercheur sur le plan scientifique, artistique et humain, parle de la remise en question des hommes et la remise en question scientifique fondamentale ou exemplaire- plusieurs personnes prennent la parole p.ex Jeanmairet, Adam, Gregory. Le Prof.Gregory clot la soirée en remerciant le Prof.Leprince-Ringuet

  13. Problem of Questioning

    ScienceCinema

    None

    2016-07-12

    Le Prof.Leprince-Ringuet, chercheur sur le plan scientifique, artistique et humain, parle de la remise en question des hommes et la remise en question scientifique fondamentale ou exemplaire- plusieurs personnes prennent la parole p.ex Jeanmairet, Adam, Gregory. Le Prof.Gregory clot la soirée en remerciant le Prof.Leprince-Ringuet

  14. “A question of balance”: addressing the public health impacts of multinational enterprises in the OECD Guidelines for Multinational Enterprises

    PubMed Central

    Yang, Joshua S.; McDaniel, Patricia A.; Malone, Ruth E.

    2012-01-01

    Background The global community is beginning to address non-communicable diseases, but how to increase the accountability of multinational enterprises (MNEs) for the health impacts of their products and practices remains unclear. We examine the Organization for Economic Cooperation and Development’s (OECD) efforts to do so through voluntary MNE guidelines. Methods We developed a historical case study of how the OECD Guidelines for Multinational Enterprises were developed and revised from 1973–2000 through an analysis of publicly available archived OECD and tobacco industry documents. Results The first edition of the Guidelines was a purely economic instrument. Outside pressures and a desire to ward off more stringent regulatory efforts resulted in the addition over time of guidelines related to the environment, consumer interests, sustainable development, and human rights. Conclusion Despite their voluntary nature, the Guidelines can play a role in efforts to help balance the interests of MNEs and public health by providing a starting point for efforts to create binding provisions addressing MNEs’ contributions to disease burden or disease reduction. PMID:23046298

  15. What is a Question?

    NASA Technical Reports Server (NTRS)

    Knuth, Kevin H.; Clancy, Daniel (Technical Monitor)

    2002-01-01

    A given question can be defined in terms of the set of statements or assertions that answer it. Application of the logic of inference to this set of assertions allows one to derive the logic of inquiry among questions. There are interesting symmetries between the logics of inference and inquiry; where probability describes the degree to which a premise implies an assertion, there exists an analogous quantity that describes the bearing or relevance that a question has on an outstanding issue. These have been extended to suggest that the logic of inquiry results in functional relationships analogous to, although more general than, those found in information theory. Employing lattice theory, I examine in greater detail the structure of the space of assertions and questions demonstrating that the symmetries between the logical relations in each of the spaces derive directly from the lattice structure. Furthermore, I show that while symmetries between the spaces exist, the two lattices are not isomorphic. The lattice of assertions is described by a Boolean lattice 2(sup N) whereas the lattice of real questions is shown to be a sublattice of the free distributive lattice FD(N) = 2(sup 2(sup N)). Thus there does not exist a one-to-one mapping of assertions to questions, there is no reflection symmetry between the two spaces, and questions in general do not possess unique complements. Last, with these lattice structures in mind, I discuss the relationship between probability, relevance and entropy.

  16. How Deep is the Critical Zone: A Scientific Question with Potential Impact For Decision-makers in Areas of Shale-Gas Development and Hydraulic Fracturing

    NASA Astrophysics Data System (ADS)

    Brantley, S. L.

    2014-12-01

    Citizens living in areas of shale-gas development such as the Marcellus gas play in Pennsylvania and surrounding states are cognizant of the possibility that drilling and production of natural gas -- including hydraulic fracturing -- may have environmental impacts on their water. The Critical Zone is defined as the zone from vegetation canopy to the lower limits of groundwater. This definition is nebulous in terms of the lower limit, and yet, defining the bottom of the Critical Zone is important if citizens are to embrace shale-gas development. This is because, although no peer-reviewed study has been presented that documents a case where hydraulic fracturing or formation fluids have migrated upwards from fracturing depths to drinking water resources, a few cases of such leakage have been alleged. On the other hand, many cases of methane migration into aquifers have been documented to occur and some have been attributed to shale-gas development. The Critical Zone science community has a role to play in understanding such contamination problems, how they unfold, and how they should be ameliorated. For example, one big effort of the Critical Zone science community is to promote sharing of data describing the environment. This data effort has been extended to provide data for citizens to understand water quality by a team known as the Shale Network. As scientists learn to publish data online, these efforts must also be made accessible to non-scientists. As citizens access the data, the demand for data will grow and all branches of government will eventually respond by providing more accessible data that will help the public and policy-makers make decisions.

  17. Managing Affect in Learners' Questions in Undergraduate Science

    ERIC Educational Resources Information Center

    Pedrosa-de-Jesus, Helena; Watts, Mike

    2014-01-01

    This article aims to position students' classroom questioning within the literature surrounding affect and its impact on learning. The article consists of two main sections. First, the act of questioning is discussed in order to highlight how affect shapes the process of questioning, and a four-part genesis to question-asking that we call…

  18. EPA Subaward Frequent Questions

    EPA Pesticide Factsheets

    These answers to frequent questions (FQ) are intended to provide information to recipients of EPA financial assistance to help them understand EPA’s interpretations of the Uniform Grant Guidance (UGG) and EPA’s Subaward Policy.

  19. Exam Question Exchange.

    ERIC Educational Resources Information Center

    Alexander, John J.

    1980-01-01

    Provides exam questions and solutions for a problem in amplification sequence of reactions, and a problem in applying group theory techniques and making spectral assignments and structural determination by qualitative arguments in the bonding in metal complexes. (CS)

  20. Rubella: Questions and Answers

    MedlinePlus

    ... of special precautions. Does the MMR vaccine cause autism? There is no scientific evidence that measles, MMR, ... other vaccine causes or increases the risk of autism. The question about a possible link between MMR ...

  1. Perchlorate Questions and Answers

    MedlinePlus

    ... EPA's Interim Health Advisory for Perchlorate in Public Water Systems On January 8, 2009, the Environmental Protection ... thyroid hormone. Questions and Answers about EPA’s Drinking Water Findings If perchlorate is present in my drinking ...

  2. Impact of Scientific Versus Emotional Wording of Patient Questions on Doctor-Patient Communication in an Internet Forum: A Randomized Controlled Experiment with Medical Students

    PubMed Central

    Bientzle, Martina; Griewatz, Jan; Küppers, Julia; Cress, Ulrike; Lammerding-Koeppel, Maria

    2015-01-01

    Background Medical expert forums on the Internet play an increasing role in patient counseling. Therefore, it is important to understand how doctor-patient communication is influenced in such forums both by features of the patients or advice seekers, as expressed in their forum queries, and by characteristics of the medical experts involved. Objective In this experimental study, we aimed to examine in what way (1) the particular wording of patient queries and (2) medical experts’ therapeutic health concepts (for example, beliefs around adhering to a distinctly scientific understanding of diagnosis and treatment and a clear focus on evidence-based medicine) impact communication behavior of the medical experts in an Internet forum. Methods Advanced medical students (in their ninth semester of medical training) were recruited as participants. Participation in the online forum was part of a communication training embedded in a gynecology course. We first measured their biomedical therapeutic health concept (hereinafter called “biomedical concept”). Then they participated in an online forum where they answered fictitious patient queries about mammography screening that either included scientific or emotional wording in a between-group design. We analyzed participants’ replies with regard to the following dimensions: their use of scientific or emotional wording, the amount of communicated information, and their attempt to build a positive doctor-patient relationship. Results This study was carried out with 117 medical students (73 women, 41 men, 3 did not indicate their sex). We found evidence that both the wording of patient queries and the participants’ biomedical concept influenced participants’ response behavior. They answered emotional patient queries in a more emotional way (mean 0.92, SD 1.02) than scientific patient queries (mean 0.26, SD 0.55; t 74=3.48, P<.001, d=0.81). We also found a significant interaction effect between participants’ use of

  3. How Effective Are Your Questions?

    ERIC Educational Resources Information Center

    Partin, Ronald L.

    1979-01-01

    Guidelines are given to the teacher on using questions to improve classroom discussions. Included are: reasons for using questions, ways to ask questions and acknowledge students' responses, and types of questions which should and should not be used. (SJL)

  4. Lunar Geoscience: Key Questions for Future Lunar Exploration

    NASA Astrophysics Data System (ADS)

    Head, James

    2014-05-01

    Lunar Geoscience: Key Questions for Future Lunar Exploration James W. Head, Department of Geological Sciences, Brown University, Providence, RI 02912 USA. (Invited paper/solicited talk for EGU 2014 PS2.3 Lunar session, Bernard H. Foing, Convener EGU PS2.3) The last several decades of intensive robotic exploration of the Moon has built on early Apollo and Luna exploration to provide fundamental knowledge of Earth's satellite and an excellent perspective on the most well-documented planetary body other than Earth. This new planetological perspective has raised substantial new questions about the nature of the origin of the Moon, its early differentiation and bombardment history, its internal thermal evolution, the production of its secondary crust as exemplified by the lunar maria, and tertiary crust as potentially seen in steep-sided domes and impact melt differentiates, the abundance of interior volatiles and their role in volcanic eruptions, and the abundance of surface volatiles and their concentration in polar regions. On the basis of this new information, a series of specific outstanding geoscience questions can be identified that can serve as guides for future human and robotic exploration. These include: 1) What is the nature and abundance of impact melt seas and what rock types do they produce upon differentiation and solidification? 2) Where are lunar mantle samples located on the lunar surface and what processes are responsible for placing them there? 3) What processes are responsible for producing the silica-rich viscous domes, such as those seen at Gruithuisen? 4) What are the volatile species involved in the emplacement of lunar pyroclastic deposits and what clues do they provide about deep magmatic volatiles and shallow volatile formation processes? 5) How do we account for the differing characteristics of regional dark mantling pyroclastic deposits? 6) When did mare basalt volcanism begin (earliest cryptmaria) and how and where is it manifested? 7

  5. Sources of clasts in terrestrial impact melts - Clues to the origin of LKFM. [Low-K Fra Mauro

    NASA Technical Reports Server (NTRS)

    Mccormick, K. A.; Taylor, G. J.; Keil, K.; Spudis, P. D.; Grieve, R. A. F.

    1989-01-01

    Low-K Fra Mauro (LKFM) 'basalt', which is found exclusively as an impact melt rock, cannot be modeled geochemically from its clast population or from any combination of known pristine lunar rock types. To clarify clast/melt relationships, a study was made of impact melt rocks from Mistastin Lake crater, Labrador, where there are only three target rocks: anorthosite, quartz monzonite, and granodiorite. Feldspar compositions in these rocks define distinct fields on the An-Ab-Or ternary diagram, making it possible to identify the source of each feldspar clast. Clasts in the Mistastin impact melts do not reflect the abundance of target rocks melted during the impact. The abundance of anorthosite in the clast population varies from 34 to 100 percent compared to a relatively constant value of 65 percent calculated to be in the melt matrix. Therefore the clasts appear to be derived predominantly from material relatively far removed from the zone of impact melting. Melt-matrix composition is dictated strictly by the composition of the target materials within a small radius around and below the point of impact. This suggests that the LKFM composition was derived from a lower crustal source.

  6. Impact of Primary and Secondary Social Origin Factors on the Transition to University in the Czech Republic

    ERIC Educational Resources Information Center

    Simonová, Natalie; Soukup, Petr

    2015-01-01

    The main objective of this paper is to show to what extent and why students with the same academic aptitude but different social backgrounds have different odds of entering university. For our analysis, we separated primary and secondary factors of social origin in the formation of educational inequalities. The results show that the primary and…

  7. Questioning Ohio's Loyalty Requirement

    ERIC Educational Resources Information Center

    O'Neil, Robert M.

    2006-01-01

    Beginning this past summer, all new employees at some Ohio public universities, including those accepting teaching positions, are being confronted with politically sensitive and intrusive questions. In addition to the "Have you solicited any individual for membership in an organization on the U.S. Department of State Terrorist…

  8. A question of choice.

    PubMed

    Grabiner, Gene

    2011-06-22

    Women's reproductive rights, reproductive health, and constitutional privacy rights in the United States are addressed in light of the contemporary onslaught of the Christian Right. The misuse of State power by fundamentalist social forces in America is critiqued. The article also briefly reviews the question of State control over women's bodies.

  9. A Question of Character

    ERIC Educational Resources Information Center

    Stuart, Reginald

    2010-01-01

    When intern placement veteran Jacqueline Perkins begins counseling students at Florida A&M University (FAMU) about their prospects for getting well-paying, security-related jobs with the federal government, she confronts the 800-pound gorilla in the room--the question of whether a student has been convicted of or pleaded guilty to a…

  10. Exam Question Exchange.

    ERIC Educational Resources Information Center

    Alexander, John J., Ed.

    1978-01-01

    Two exam questions are presented. One suitable for advanced undergraduate or beginning graduate courses in organic chemistry, is on equivalent expressions for the description of several pericyclic reactions. The second, for general chemistry students, asks for an estimation of the rate of decay of a million-year-old Uranium-238 sample. (BB)

  11. My Favorite Exam Question

    ERIC Educational Resources Information Center

    Styer, Dan

    2015-01-01

    My favorite exam question comes from the final exam in an introductory mechanics course: "A rolling 31 ton railroad boxcar collides with a stationary flatcar. The coupling mechanism activates so the cars latch together and roll down the track attached. Of the initial kinetic energy, 38% dissipates as heat, sound, vibrations, mechanical…

  12. A Question of Choice

    PubMed Central

    2011-01-01

    Women's reproductive rights, reproductive health, and constitutional privacy rights in the United States are addressed in light of the contemporary onslaught of the Christian Right. The misuse of State power by fundamentalist social forces in America is critiqued. The article also briefly reviews the question of State control over women's bodies. PMID:21696627

  13. Asking Questions about Participation

    ERIC Educational Resources Information Center

    Davies, Ian; Flanagan, Bernie; Hogarth, Sylvia; Mountford, Paula; Philpott, Jenny

    2009-01-01

    We raise questions about young people's participation in light of findings from a project ("Democracy through Citizenship") funded by the Joseph Rowntree Reform Trust Limited, and managed by the Institute for Citizenship. Following a six-month feasibility study the project took place over a three-year period in one local authority in the…

  14. Asking the Right Questions

    ERIC Educational Resources Information Center

    Lord, Rob

    2011-01-01

    As a student teacher at Nottingham Trent University, the author explored the issues surrounding children asking investigable questions in science and the repertoire of strategies that could be employed by teachers in the classroom to support this process. His project was carried out in an inner-city primary school in Nottingham. The four focus…

  15. The Compensation Question

    ERIC Educational Resources Information Center

    Richwine, Jason; Biggs, Andrew; Mishel, Lawrence; Roy, Joydeep

    2012-01-01

    Over the past few years, as cash-strapped states and school districts have faced tough budget decisions, spending on teacher compensation has come under the microscope. The underlying question is whether, when you take everything into account, today's teachers are fairly paid, underpaid, or overpaid. In this forum, two pairs of respected…

  16. What Is the Question?

    ERIC Educational Resources Information Center

    Woodruff, Melba D.

    Second language educators need to examine in greater depth the learning processes of young children in order to provide them with the kind of teaching they need in order to really learn. This means searching other fields to learn as much as possible about: questioning strategies and the development of critical thinking skills; hemispheric…

  17. That Is the Question.

    ERIC Educational Resources Information Center

    Korsunsky, Syd

    2002-01-01

    Describes the author's evolution from a teacher set in his ways to one who adapted to students' voices. Contends that classrooms need to be environments where students are able to ask their own questions. Explains that key elements of such an environment include the following: interviews; mini-lessons; multi-genre projects; literature circles;…

  18. Questioning and Experimentation

    ERIC Educational Resources Information Center

    Mutanen, Arto

    2014-01-01

    The paper is a philosophical analysis of experimentation. The philosophical framework of the analysis is the interrogative model of inquiry developed by Hintikka. The basis of the model is explicit and well-formed logic of questions and answers. The framework allows us to formulate a flexible logic of experimentation. In particular, the formulated…

  19. Questioning in the Classroom.

    ERIC Educational Resources Information Center

    Hyman, Ronald T.

    This study investigates the pattern of teacher questioning regarding three elements: sequence, student respondent, and cognitive process. The rationale for this type of teaching rests on the claims for teaching students the process of critical (reflective) thinking. In this type of teaching it is necessary to have data before the students. Only…

  20. Answering Consumer Questions: Opportunity for Impact

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Food can be a touchy subject. It seems people either have very strong thoughts and opinions on food or they could care less as long as food is available to feed them and their families. With the current economic environment, many individuals are examining food choices more closely to ensure the g...

  1. The great lunar hot spot and the composition and origin of the Apollo mafic (``LKFM'') impact-melt breccias

    NASA Astrophysics Data System (ADS)

    Korotev, Randy L.

    2000-02-01

    Thorium-rich, mafic impact-melt breccias from the Apollo 14-17 missions, that is, those breccias identified with the composition known as ``LKFM,'' are regarded largely as products of basin-forming impacts that penetrated the feldspathic crust and sampled underlying mafic material and magma-ocean residuum carrying the compositional signature of KREEP (potassium, rare earth elements, phosphorous). Despite considerable compositional variation among such breccias, compositions of all of them correspond to mixtures of only four components: (1) a norite with composition generally similar to that of Apollo 15 basalt (mean abundance: 58% range: ~30-95%), (2) Fo~90 dunite (mean: 13%, range: 1-27%), (3) feldspathic upper crust (mean: 29%, range: 4-50%), and FeNi metal (0.1-1.7%). Petrographic evidence has shown that much of the feldspathic component, but none of the KREEP component, is clastic. This observation and the high proportion of KREEP norite component in the breccias suggest that the melt zone of the impact or impacts forming the breccias contained little feldspathic material but consisted predominantly of material with the average composition of KREEP norite. The dunite component probably derives ultimately from the upper mantle. These conclusions support the hypothesis that the breccias were not formed in typical feldspathic crust but instead by one or more impacts into what is designated here ``the great lunar hot spot,'' that is, the anomalous Th-rich terrane in the Imbrium-Procellarum area identified by the Apollo and Lunar Prospector gamma-ray spectrometers. The LKFM composition is a special product of the great lunar hot spot and is not the average composition of the lower crust in typical feldspathic highlands. Similarly, Mg-suite and alkali-suite plutonic rocks of the Apollo collection are likely all differentiation products of the hot spot, not of plutons that might occur in typical feldspathic crust.

  2. Do Contaminants Originating from State-of-the-Art Treated Wastewater Impact the Ecological Quality of Surface Waters?

    PubMed Central

    Stalter, Daniel; Magdeburg, Axel; Quednow, Kristin; Botzat, Alexandra; Oehlmann, Jörg

    2013-01-01

    Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0–100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn), 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide) as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in urban areas this

  3. Big questions about the universe

    NASA Astrophysics Data System (ADS)

    Stavinschi, Magda

    2011-06-01

    Astronomy is not only a branch of science but also an important part of the culture and civilisations of peoples. Starting with archeoastronomy to the present day, it has always contributed to a better understanding of life, of humanity. After 400 years of modern astronomy, it still addresses major problems such as: Why there is something rather than nothing? Why is nature comprehensible to humans? How is cosmos related to humanity? Do multiverses exist? Is there life on other planets? Are we alone in the universe? Does the universe have a beginning? If so, what does it mean? How did the universe originate? All these questions are a challenge for interdisciplinary and transdisciplinary investigations, for philosophers, physicists, cosmologists, mathematicians, theologians. The new insights gained by pursuing in depth these common investigations will shape the society we live in and have important consequences on the future we are creating.

  4. Knowledge based question answering

    SciTech Connect

    Pazzani, M.J.; Engelman, C.

    1983-01-01

    The natural language database query system incorporated in the Knobs Interactive Planning System comprises a dictionary driven parser, APE-II, and script interpreter whch yield a conceptual dependency as a representation of the meaning of user input. A conceptualisation pattern matching production system then determines and executes a procedure for extracting the desired information from the database. In contrast to syntax driven q-a systems, e.g. those based on atn parsers, APE-II is driven bottom-up by expectations associated with word meanings. The goals of this approach include utilising similar representations for questions with similar meanings but widely varying surface structures, developing a powerful mechanism for the disambiguation of words with multiple meanings and the determination of pronoun referents, answering questions which require inferences to be understood, and interpreting ellipses and ungrammatical statements. The Knobs demonstration system is an experimental, expert system for air force mission planning applications. 16 refs.

  5. Benedict Arnold: A Question of Honor.

    ERIC Educational Resources Information Center

    Nicolosi, Annie; O'Connell, Libby Haight; Rust, Mead

    2003-01-01

    The spring 2003 The Idea Book for Educators highlights television programming from the Arts and Entertainment Network (A&E), the History Channel, and the Biography Channel, with a focus on an A&E original movie premiere, "Benedict Arnold: A Question of Honor." The booklet contains the following materials: "A&E Study…

  6. Questions of wisdom.

    PubMed

    Schmidt Bunkers, Sandra

    2009-04-01

    In this column questions concerning wisdom are addressed, such as, what is wisdom? Can wisdom be taught in the academy? Several perspectives on wisdom from philosophy, education, business, and psychology are presented. Wisdom with creativity-creativity with wisdom is then explored through discussion of Parse's humanbecoming teaching-learning model and Laird Hamilton's life lessons learned from surfing, which he termed wisdom of the wave. The column concludes with consideration of the wise person.

  7. Quantum theory from questions

    NASA Astrophysics Data System (ADS)

    Höhn, Philipp Andres; Wever, Christopher S. P.

    2017-01-01

    We reconstruct the explicit formalism of qubit quantum theory from elementary rules on an observer's information acquisition. Our approach is purely operational: we consider an observer O interrogating a system S with binary questions and define S 's state as O 's "catalog of knowledge" about S . From the rules we derive the state spaces for N elementary systems and show that (a) they coincide with the set of density matrices over an N -qubit Hilbert space C2N; (b) states evolve unitarily under the group PSU (2N) according to the von Neumann evolution equation; and (c) O 's binary questions correspond to projective Pauli operator measurements with outcome probabilities given by the Born rule. As a by-product, this results in a propositional formulation of quantum theory. Aside from offering an informational explanation for the theory's architecture, the reconstruction also unravels previously unnoticed structural insights. We show that, in a derived quadratic information measure, (d) qubits satisfy inequalities which bound the information content in any set of mutually complementary questions to 1 bit; and (e) maximal sets of mutually complementary questions for one and two qubits must carry precisely 1 bit of information in pure states. The latter relations constitute conserved informational charges which define the unitary groups and, together with their conservation conditions, the sets of pure quantum states. These results highlight information as a "charge of quantum theory" and the benefits of this informational approach. This work emphasizes the sufficiency of restricting to an observer's information to reconstruct the theory and completes the quantum reconstruction initiated in a companion paper (P. Höhn, arXiv:1412.8323).

  8. Questioning Many Mysteries

    NASA Astrophysics Data System (ADS)

    Martin, Sara F.

    2015-04-01

    The first section of this memoir queries my formative years. Indirectly I address the question, did my childhood and early years make a difference in my choice of career? Why and how did I begin my journey to becoming a scientist? Did I choose the field of solar astronomy or did circumstances dictate it for me? In the second section, I travel through my work environments and experiences, talking about interactions and aspects of being a scientist that do not appear in our research papers. What parts of my research were happenstances and what parts did I plan? What does it feel like to be on scientific quests? Using examples in my journey, I also turn to questions that have intrigued me throughout my sojourn as a solar astronomer. How do scientific discoveries come about? What factors lead to little discoveries? And what factors lead to major exciting discoveries? Are there timely questions we do not think to ask? How can small, seemingly scattered pieces of knowledge suddenly coalesce into a deeper understanding - what is called the "Aha!" experience - the times when our mental light switches on, and with child-like wonder we behold a "big picture"?

  9. Open questions in classical gravity

    SciTech Connect

    Mannheim, P.D. )

    1994-04-01

    In this work, the authors discuss some outstanding open questions regarding the validity and uniqueness of the standard second-order Newton-Einstein classical gravitational theory. On the observational side the authors discuss the degree to which the realm of validity of Newton's law of gravity can actually be extended to distances much larger than the solar system distance scales on which the law was originally established. On the theoretical side the authors identify some commonly accepted (but actually still open to question) assumptions which go into the formulation of the standard second-order Einstein theory in the first place. In particular, it is shown that while the familiar second-order Poisson gravitational equation (and accordingly its second-order covariant Einstein generalization) may be sufficient to yield Newton's law of gravity they are not in fact necessary. The standard theory thus still awaits the identification of some principle which would then make it necessary too. It is shown that current observational information does not exclusively mandate the standard theory, and that the conformal invariant fourth-order theory of gravity considered recently by Mannheim and Kazanas is also able to meet the constraints of data, and in fact to do so without the need for any so far unobserved nonluminous or dark matter. 37 refs., 7 figs.

  10. Les questions de migrations internationales

    NASA Astrophysics Data System (ADS)

    Samman, Mouna Liliane

    1993-03-01

    International migrations have growing implications for both countries of origin and countries of destination. In the latter, the presence of foreigners and of members of their families today creates problems of integration, causes argument and brings mounting xenophobia. Paralleling political, economic and social measures taken by public authorities to respond to these difficulties, education needs to assist in defusing the resulting social tensions by preparing the minds of learners and helping to develop new attitudes. In particular, when educational programmes address questions of international migration, these should be treated in the framework of historical evolution so that their real significance and their true temporal and spatial dimensions become apparent. It is also important that the growing interdependence between countries should be made plain, that national history should be placed in its international context, and that the true consequences of these developments should be made clear. In this context, learners need to be acquainted with Human Rights, thereby stressing universal moral values and the role of the individual. Lastly, questions relating to international migration are usually presented in the media in a selective and partial manner, and the young people who take in this information often accept the hasty judgments which are made of situations as proven facts. This is why all teaching about international migration needs to be considered or reconsidered in the light of the complementary or competing actions of the media.

  11. Early Archean Spherule Beds: Chromium Isotopes Confirm Origin Through Multiple Impacts of Projectiles of Carbonaceous Chondrite Type

    NASA Technical Reports Server (NTRS)

    Kyte, Frank T.; Shukolyukov, Alex; Lugmair, Guenter W.; Lowe, Donald R.; Byerly, Gary R.

    2003-01-01

    Three Early Archean spherule beds from Barberton, South Africa, have anomalous Cr isotope compositions in addition to large Ir anomalies, confirming the presence of meteoritic material with a composition similar to that in carbonaceous chondrites. The extra-terrestrial components in beds S2, S3, and S4 are estimated to be approx. l%, 50% - 60%, and 15% - 30%, respectively. These beds are probably the distal, and possibly global, ejecta from major large-body impacts. These impacts were probably much larger than the Cretaceous-Tertiary event, and all occurred over an interval of approx. 20 m.y., implying an impactor flux at 3.2 Ga that was more than an order of magnitude greater than the present flux.

  12. Metal/sulfide-silicate intergrowth textures in EL3 meteorites: Origin by impact melting on the EL parent body

    NASA Astrophysics Data System (ADS)

    van Niekerk, Deon; Keil, Klaus

    2011-10-01

    We document the petrographic setting and textures of Fe,Ni metal, the mineralogy of metallic assemblages, and the modal mineral abundances in the EL3 meteorites Asuka (A-) 881314, A-882067, Allan Hills 85119, Elephant Moraine (EET) 90299/EET 90992, LaPaz Icefield 03930, MacAlpine Hills (MAC) 02635, MAC 02837/MAC 02839, MAC 88136, Northwest Africa (NWA) 3132, Pecora Escarpment 91020, Queen Alexandra Range (QUE) 93351/QUE 94321, QUE 94594, and higher petrologic type ELs Dar al Gani 1031 (EL4), Sayh al Uhaymir 188 (EL4), MAC 02747 (EL4), QUE 94368 (EL4), and NWA 1222 (EL5). Large metal assemblages (often containing schreibersite and graphite) only occur outside chondrules and are usually intergrown with silicate minerals (euhedral to subhedral enstatite, silica, and feldspar). Sulfides (troilite, daubréelite, and keilite) are also sometimes intergrown with silicates. Numerous authors have shown that metal in enstatite chondrites that are interpreted to have been impact melted contains euhedral crystals of enstatite. We argue that the metal/sulfide-silicate intergrowths in the ELs we studied were also formed during impact melting and that metal in EL3s thus does not retain primitive (i.e., nebular) textures. Likewise, the EL4s are also impact-melt breccias. Modal abundances of metal in the EL3s and EL4s range from approximately 7 to 30 wt%. These abundances overlap or exceed those of EL6s, and this is consistent either with pre-existing heterogeneity in the parent body or with redistribution of metal during impact processes.

  13. Asteroid impact vs. Deccan eruptions: The origin of low magnetic susceptibility beds below the Cretaceous-Paleogene boundary revisited

    NASA Astrophysics Data System (ADS)

    Abrajevitch, Alexandra; Font, Eric; Florindo, Fabio; Roberts, Andrew P.

    2015-11-01

    The respective roles of an asteroid impact and Deccan Traps eruptions in biotic changes at the Cretaceous-Paleogene (K-Pg) boundary are still debated. In many shallow marine sediments from around the world, the K-Pg boundary is marked by a distinct clay layer that is often underlain by a several decimeter-thick low susceptibility zone. A previous study of the Gubbio section, Italy (Lowrie et al., 1990), attributed low magnetization intensity in this interval to post-depositional dissolution of ferrimagnetic minerals. Dissolution was thought to be a consequence of downward infiltration of reducing waters that resulted from rapid accumulation of organic matter produced by mass extinctions after the K-Pg event. We compare the magnetic properties of sediments from the Gubbio section with those of the Bidart section in southern France. The two sections are similar in their carbonate lithology and the presence of a boundary clay and low susceptibility zone. When compared to background Cretaceous sediments, the low susceptibility zone in both sections is marked by an absence of biogenic magnetite, a decrease in total ferrimagnetic mineral content, and a preferential loss of magnetite with respect to hematite - features that are consistent with reductive dissolution. However, unlike the Gubbio section, where the low susceptibility zone starts immediately below the boundary clay, the low susceptibility zone and the clay layer at Bidart are separated by a ∼4-cm carbonate interval that contains abundant biogenic magnetite. Such separation casts doubt on a causal link between the impact and sediment bleaching. More likely, the low susceptibility layer marks a different environmental event that preceded the impact. An episode of increased atmospheric and oceanic acidity associated with Deccan Traps volcanism that occurred well before the K-Pg impact is argued here to account for the distinct magnetic properties of the low susceptibility intervals.

  14. A Universe of Questions.

    ERIC Educational Resources Information Center

    Zeldovich, Yakov

    1992-01-01

    Reprinted from the original Russian manuscript of Yakov Zeldovich, this article chronicles his studies of the universe and his attempts to construct a theory of its evolution. He provides the high school student with compelling cosmological discussions about uniformity, galactic clusters, radiation, evolution, the big bang, and gravitational…

  15. A Question of Evidence

    ERIC Educational Resources Information Center

    Todd, Ross J.

    2008-01-01

    Broadly defined, evidence-based practice (EBP) is fundamentally about professional practice being informed and guided by best available evidence of what works. The EBP movement had its origins in the early 1990s in the United Kingdom in medicine and health care services. Sackett et al. defined evidence-based medicine as the "conscientious,…

  16. Questions, Relatives, and Minimal Projection.

    ERIC Educational Resources Information Center

    Demuth, Katherine

    1995-01-01

    This article examines the acquisition of wh-questions and relative clauses in Sesotho, a language with no wh-movement in either questions or relatives, and in which wh-questions must be clefted. (10 references) (JL)

  17. The Art of Asking Questions.

    ERIC Educational Resources Information Center

    Sykes, Rosetta A.

    1979-01-01

    A rationale is given for the use of questioning techniques and strategies in classroom instruction. B. Bloom's Taxonomy of Educational Objectives is presented as one framework for questions. Five pitfalls, including avoiding vague questions and personal pronouns, are discussed. (CL)

  18. Open questions about giant viruses.

    PubMed

    Claverie, Jean-Michel; Abergel, Chantal

    2013-01-01

    The recent discovery of giant viruses exhibiting double-stranded DNA genomes larger than a million base pairs, encoding more than a thousand proteins and packed in near micron-sized icosahedral particles, opened a new and unexpected chapter in virology. As of today, these giant viruses and their closest relatives of lesser dimensions infect unicellular eukaryotes found in aquatic environments, but belonging to a wide diversity of early branching phyla. This broad phylogenetic distribution of hosts is consistent with the hypothesis that giant viruses originated prior to the radiation of the eukaryotic domain and/or might have been involved in the partition of nuclear versus cytoplasmic functions in ancestral cells. The distinctive features of the known giant viruses, in particular the recurrent presence of components of the translation apparatus in their proteome, raise a number of fundamental questions about their origin, their mode of evolution, and the relationship they may entertain with other dsDNA viruses, the genome size of which exhibits the widest distribution among all biological entities, from less than 5 kb to more than 1.25 Mb (a ratio of 1:250). At a more conceptual level, the convergence between the discovery of increasingly reduced parasitic cellular organisms and that of giant viruses exhibiting a widening array of cellular-like functions may ultimately abolish the historical discontinuity between the viral and the cellular world.

  19. [Origin of biosphere].

    PubMed

    Levchenko, V F; Starobogatov, Ia I

    2010-01-01

    Concepts of origin of life on the planet are briefly considered. The problem of origin of biosphere is discussed, with a suggestion that the origin of living organisms and biosphere are two aspects of the same process. There is put forward a hypothesis of embryosphere--the primary medium, in which preorganisms could appear. The ecosystemic approach to origin of life poses a question about sources of the matter and energy used by the primary life as well as about causes of the biochemical unity that exists in all Earth organisms.

  20. Questioning and Experimentation

    NASA Astrophysics Data System (ADS)

    Mutanen, Arto

    2014-08-01

    The paper is a philosophical analysis of experimentation. The philosophical framework of the analysis is the interrogative model of inquiry developed by Hintikka. The basis of the model is explicit and well-formed logic of questions and answers. The framework allows us to formulate a flexible logic of experimentation. In particular, the formulated model can be interpreted realistically. Moreover, the model demonstrates an explicit logic of knowledge acquisition. So, the natural extension of the model is to apply it to an analysis of the learning process.

  1. Geophysical anomalies and quartz microstructures, Eastern Warburton Basin, North-east South Australia: Tectonic or impact shock metamorphic origin?

    NASA Astrophysics Data System (ADS)

    Glikson, Andrew Y.; Uysal, I. Tonguç; Fitz Gerald, John D.; Saygin, Erdinc

    2013-03-01

    The Eastern Warburton Basin, Northeast South Australia, features major geophysical anomalies, including a magnetic high of near-200 nT centred on a 25 km-wide magnetic low (< 100 nT), interpreted in terms of a magmatic body below 6 km depth. A distinct seismic tomographic low velocity anomaly may reflect its thick (9.5 km) sedimentary section, high temperatures and possible deep fracturing. Scanning electron microscope (SEM) analyses of granites resolves microbreccia veins consisting of micron-scale particles injected into resorbed quartz grains. Planar and sub-planar elements in quartz grains (Qz/PE) occur in granites, volcanics and sediments of the > 30,000 km-large Eastern Warburton Basin. The Qz/PE include multiple intersecting planar to curved sub-planar elements with relic lamellae less than 2 μm wide with spacing of 4-5 μm. Qz/PE are commonly re-deformed, displaying bent and wavy patterns accompanied with fluid inclusions. U-stage measurements of a total of 243 planar sets in 157 quartz grains indicate dominance of ∏{10-12}, ω{10-13} and subsidiary §{11-22}, {22-41}, m{10-11} and x{51-61} planes. Transmission Electron Microscopy (TEM) analysis displays relic narrow ≤ 1 μm-wide lamellae and relic non-sub grain boundaries where crystal segments maintain optical continuity. Extensive sericite alteration of feldspar suggests hydrothermal alteration to a depth of 500 m below the unconformity which overlies the Qz/PE-bearing Warburton Basin terrain. The data are discussed in terms of (A) Tectonic-metamorphic deformation and (B) impact shock metamorphism producing planar deformation features (Qz/PDF). Deformed Qz/PE are compared to re-deformed Qz/PDFs in the Sudbury, Vredefort, Manicouagan and Charlevoix impact structures. A 4-5 km uplift of the Big Lake Granite Suite during 298-295 Ma is consistent with missing of upper Ordovician to Devonian strata and possible impact rebound. The occurrence of circular seismic tomography anomalies below the east

  2. Early Archean Spherule Beds: Chromium Isotopes Confirm Origin through Multiple Impacts of Projectiles of Carbonaceous Chondrite Type: Comment and Reply

    NASA Technical Reports Server (NTRS)

    Kyte, Frank T.

    2003-01-01

    This is a exchange in the form of a comment and a reply in regards to an earlier article. The authors of the original article, consider it likely that virtually all of the projectile will condense with the silicate fraction, resulting in very little platinum group element fractionation in the final ejecta deposit. Further, we find no evidence in the commentator's, (i.e., Glikson), comment to support vapor fractionation. We note that the Pd/Ir ratios of published data on 2.56 Ga Hamersley Basin spherules are all greater than in chondrites, contrary to the assertion by Glikson. This is consistent with relatively high Pd concentrations (and Pd/Ir ratios) in crustal rocks.

  3. Impact of information on intentions to vaccinate in a potential epidemic: Swine-origin Influenza A (H1N1).

    PubMed

    Chanel, Olivier; Luchini, Stéphane; Massoni, Sébastien; Vergnaud, Jean-Christophe

    2011-01-01

    Vaccination campaigns to prevent the spread of epidemics are successful only if the targeted populations subscribe to the recommendations of health authorities. However, because compulsory vaccination is hardly conceivable in modern democracies, governments need to convince their populations through efficient and persuasive information campaigns. In the context of the swine-origin A (H1N1) 2009 pandemic, we use an interactive study among the general public in the South of France, with 175 participants, to explore what type of information can induce change in vaccination intentions at both aggregate and individual levels. We find that individual attitudes to vaccination are based on rational appraisal of the situation, and that it is information of a purely scientific nature that has the only significant positive effect on intention to vaccinate.

  4. Approaches to Cell Biology Teaching: Questions about Questions

    ERIC Educational Resources Information Center

    Allen, Deborah; Tanner, Kimberly

    2002-01-01

    There are many questions to be asked about the pedagogical practice of questioning. Questions provide insight into what students at any age or grade level already know about a topic, which provides a beginning point for teaching. Questions reveal misconceptions and misunderstandings that must be addressed for teachers to move student thinking…

  5. The Origin and Impact of Ideals in eHealth Research: Experiences From the U-CARE Research Environment

    PubMed Central

    von Essen, Louise; Grönqvist, Helena

    2014-01-01

    Background The prevalence of information technology (IT) in society is a foundation for new modes of interaction between patients and health specialists. IT plays an important role in the renewal of care. Several countries have incorporated eHealth plans into their national health strategies. Part of the eHealth evolution concerns Internet psychological treatment and psychosocial care. These interventions are complex to design and evaluate due to legal, ethical, organizational, technical, and methodological challenges. Objective The objective of our study was to seek to make explicit contributions to the understanding of ideals in eHealth research, and illuminate their implications for establishing an effective research environment. Our analysis draws from three years of experience in establishing an eHealth research environment, and the literature. Methods We worked inductively to characterize challenging research ideals, and their origins, in our environment. Thereafter, we made a selective search of the literature to scrutinize and illuminate each ideal and it’s implications. Results In this work, we propose a structured approach to address ideals in eHealth research. The scrutinized ideals are accountability, innovation, rigor, relevance, and sustainability. The approach supports researchers to systematically understand the ideals, their origin, and to manage their implications within an eHealth research environment. Conclusions The complexity of eHealth research causes a need for sustainable, multi-disciplinary research environments. There is a need for a structured approach to organize eHealth research. The proposed approach helps to systematically scrutinize ideals, thus promoting high quality research. PMID:24860071

  6. Automatically Classifying Question Types for Consumer Health Questions

    PubMed Central

    Roberts, Kirk; Kilicoglu, Halil; Fiszman, Marcelo; Demner-Fushman, Dina

    2014-01-01

    We present a method for automatically classifying consumer health questions. Our thirteen question types are designed to aid in the automatic retrieval of medical answers from consumer health resources. To our knowledge, this is the first machine learning-based method specifically for classifying consumer health questions. We demonstrate how previous approaches to medical question classification are insufficient to achieve high accuracy on this task. Additionally, we describe, manually annotate, and automatically classify three important question elements that improve question classification over previous techniques. Our results and analysis illustrate the difficulty of the task and the future directions that are necessary to achieve high-performing consumer health question classification. PMID:25954411

  7. The Gentle Art of Questioning: Writing Great Clicker Questions

    NASA Astrophysics Data System (ADS)

    Chasteen, Stephanie

    2012-02-01

    How does a teacher use questioning effectively? This workshop will focus on writing those questions that engage students, spark their curiosity, help recap material, give you insight into their thinking, or help them learn critical ideas in physics. We will focus on ``peer instruction'' -- a research-tested method of requiring students to discuss challenging questions with one another. We will investigate the surprising power of multiple-choice questions to achieve critical thinking skills. Finally, we will look at writing questions that align with our goals for students, discuss the elements of effective questions, and practice writing questions and work on improving them.

  8. PQA: Pretty Questionable Assumptions

    ERIC Educational Resources Information Center

    Hoare, Anthony; Aitchison, Rebecca

    2009-01-01

    The intention to introduce a form of post qualification application (PQA) for entry to UK universities has provoked considerable interest, debate and controversy, not least over its impact on diversifying the intake of undergraduates gaining entry to the allegedly most prestigious universities and courses. We review the arguments and evidence…

  9. [Organization, availability and possibility of analysis of disaster data of climate related origin and its impacts on health].

    PubMed

    Xavier, Diego Ricardo; Barcellos, Christovam; Barros, Heglaucio da Silva; Magalhães, Monica de Avelar Figueiredo Mafra; Matos, Vanderlei Pascoal de; Pedroso, Marcel de Moraes

    2014-09-01

    The occurrence of disasters is often related to unforeseeable able natural processes. However, the analysis of major databases may highlight seasonal and long-term trends, as well as some spatial patterns where risks are concentrated. In this paper the process of acquiring and organizing climate-related disaster data collected by civil protection institutions and made available by the Brazilian Climate and Health Observatory is described. Preliminary analyses show the concentration of disasters caused by heavy rainfall events along the Brazilian coastline especially during the summer. Droughts have longer duration and extent, affecting large areas of the south and northeast regions of the country. These data can be used to analyze and monitor the impact of extreme climatic events on health, as well as identify the vulnerability and climate deteminants.

  10. Generation, Propagation and Impact of Giant Tsunamis of Tectonic Origin in the Mediterranean Sea: Some Hints From Preliminary Scenario Studies

    NASA Astrophysics Data System (ADS)

    Tinti, S.; Armigliato, A.; Pagnoni, G.; Tonini, R.; Zaniboni, F.

    2006-12-01

    The recent catastrophic Indian Ocean tsunami occurred on December 26, 2004 raised a number of urgent issues regarding tsunamis worldwide. The event pointed out that we have very little knowledge on mega- tsunamis and on their potential impact on human habitat. The international community is starting to define a common strategy of how to deal with these mega-events, and several projects focussed on tsunamis, with emphasis on hazard and risk assessment, have recently started or are going to start soon worldwide both at national and international levels. Properly dealing with tsunami hazard and risk is of great importance also for the Mediterranean countries, that are known to have been attacked by numerous tsunamis in the past, several of which had catastrophic size and impact. Scenarios represent a very useful technique for the definition and evaluation of tsunami hazard and risk for any given region, and a basic step in the frame of tsunami mitigation and preparedness and of sustainable coastal zone development. We present some simple scenarios of earthquake-generated tsunamis in the Mediterranean. Based on earthquake and tsunami catalogues as well as on basic seismotectonics, we identify four different seismogenic areas in the western, central and eastern sectors of the Mediterranean Sea. In each case, we choose a fault system capable of generating an earthquake with magnitude equal or larger than the highest magnitude registered in that region in historical times. We simulate the propagation of each scenario tsunami by means of a shallow-water finite-element numerical code, discuss the basic features of the wave propagation and roughly identify the Mediterranean coastal sectors expected to suffer the heaviest tsunami effects. One important outcome is that all the studied scenario tsunamis are able to produce relevant effects both locally and at trans-Mediterranean distances. Furthermore, the tsunami waves attack the nearest coasts within at most 15 minutes, which

  11. The origin of Phobos grooves from ejecta launched from impact craters on Mars: Tests of the hypothesis

    NASA Astrophysics Data System (ADS)

    Ramsley, Kenneth R.; Head, James W.

    2013-01-01

    The surface of the martian moon Phobos is characterized by parallel and intersecting grooves that bear resemblance to secondary crater chains observed on planetary surfaces. Murray (2011) has hypothesized that the main groove-forming process on Phobos is the intersection of Phobos with ejecta from primary impact events on Mars to produce chains of secondary craters. The hypothesis infers a pattern of parallel jets of ejecta, either fluidized or solidified, that break into equally-spaced fragments and disperse uniformly along-trajectory during the flight from Mars to Phobos. At the moment of impact with Phobos the dispersed fragments emplace secondary craters that are aligned along strike corresponding to the flight pattern of ejecta along trajectory. The aspects of the characteristics of grooves on Phobos cited by this hypothesis that might be explained by secondary ejecta include: their observed linearity, parallelism, planar alignment, pitted nature, change in character along strike, and a "zone of avoidance" where ejecta from Mars is predicted not to impact (Murray, 2011). To test the hypothesis we plot precise Keplerian orbits for ejecta from Mars (elliptical and hyperbolic with periapsis located below the surface of Mars). From these trajectories we: (1) set the fragment dispersion limits of ejecta patterns required to emplace the more typically well-organized parallel grooves observed in returned images from Phobos; (2) plot ranges of the ejecta flight durations from Mars to Phobos and map regions of exposure; (3) utilize the same exposure map to observe trajectory-defined ejecta exposure shadows; (4) observe hemispheric exposure in response to shorter and longer durations of ejecta flight; (5) assess the viability of ejecta emplacing the large family of grooves covering most of the northern hemisphere of Phobos; and (6) plot the arrival of parallel lines of ejecta emplacing chains of craters at oblique incident angles. We also assess the bulk volume of

  12. Engaging Students through Effective Questions

    ERIC Educational Resources Information Center

    Neal, Mary-Anne

    2011-01-01

    In what ways might questioning techniques improve student learning? What kinds of questions enable educators to tap into different parts of the cognitive domain? How can questions engage students when their attention begins to wander? Many questions at the lower levels of Bloom's Taxonomy--particularly knowledge and comprehension--are closed-ended…

  13. Improving Multiple-Choice Questions

    ERIC Educational Resources Information Center

    Torres, Cristina; Lopes, Ana Paula; Babo, Lurdes; Azevedo, Jose

    2011-01-01

    A MC (multiple-choice) question can be defined as a question in which students are asked to select one alternative from a given set of alternatives in response to a question stem. The objective of this paper is to analyse if MC questions may be considered as an interesting alternative for assessing knowledge, particularly in the mathematics area,…

  14. Unproven (questionable) cancer therapies.

    PubMed Central

    Brigden, M L

    1995-01-01

    More than half of all cancer patients use some form of alternative treatment during the course of their illness. Alternative therapies are often started early in patients' illness, and their use is frequently not acknowledged to health care professionals. Some alternative therapies are harmful, and their promoters may be fraudulent. Persons who try alternative cancer therapies may not be poorly educated but may ultimately abandon conventional treatment. Recent attention has focused on aspects of questionable therapies that make these treatments attractive to patients and that may be perceived as being deficient in the practice of conventional health care professionals. Physicians with patients with cancer should always make sure that unproven therapies are discussed early in the therapeutic relationship. They should also attempt to be aware of alternative therapies that are in vogue in their particular geographic area. PMID:8533410

  15. Common Questions about Sexual Health Education.

    ERIC Educational Resources Information Center

    McKay, Alexander

    2000-01-01

    Provides research-based answers to questions commonly posed by educators, parents, and others about the philosophy, methods, and impact of school sexual health education, discussing such issues as: whether these school programs are needed, what values they teach, whether the programs should teach about sexual orientation and abstinence, and…

  16. Systemic Sclerosis: Commonly Asked Questions by Rheumatologists

    PubMed Central

    Young, Amber; Khanna, Dinesh

    2016-01-01

    Systemic sclerosis is a rare autoimmune disorder with significant morbidity and mortality due to multi-organ system involvement. Early diagnosis and screening for organ involvement is critical as earlier treatment appears to improve function and may impact mortality. The purpose of this article is to address some of the commonly asked questions by rheumatologists on systemic sclerosis. PMID:25807095

  17. Questions of copyright.

    PubMed

    Anfray, Caroline; Emery, Marie-Pierre; Conway, Katrin; Acquadro, Catherine

    2012-01-31

    The Berne Convention and the national laws on intellectual property fully apply to PRO instruments. The identification of and access to an original PRO instrument is often associated with copyright ownership. This is the copyright holder of the instrument who will control its access (distribution and reproduction), its adaptation or modification, and its translation. Copyright is a means to protect the integrity of an instrument. The ownership of an instrument should be defined in the beginning between all parties involved, and each step of the instrument's life, including distribution, should be anticipated for purpose of copyright.

  18. MERGER RATES OF DOUBLE NEUTRON STARS AND STELLAR ORIGIN BLACK HOLES: THE IMPACT OF INITIAL CONDITIONS ON BINARY EVOLUTION PREDICTIONS

    SciTech Connect

    Mink, S. E. de; Belczynski, K. E-mail: kbelczyn@astrouw.edu.pl

    2015-11-20

    The initial mass function (IMF), binary fraction, and distributions of binary parameters (mass ratios, separations, and eccentricities) are indispensable inputs for simulations of stellar populations. It is often claimed that these are poorly constrained, significantly affecting evolutionary predictions. Recently, dedicated observing campaigns have provided new constraints on the initial conditions for massive stars. Findings include a larger close binary fraction and a stronger preference for very tight systems. We investigate the impact on the predicted merger rates of neutron stars and black holes. Despite the changes with previous assumptions, we only find an increase of less than a factor of 2 (insignificant compared with evolutionary uncertainties of typically a factor of 10–100). We further show that the uncertainties in the new initial binary properties do not significantly affect (within a factor of 2) our predictions of double compact object merger rates. An exception is the uncertainty in IMF (variations by a factor of 6 up and down). No significant changes in the distributions of final component masses, mass ratios, chirp masses, and delay times are found. We conclude that the predictions are, for practical purposes, robust against uncertainties in the initial conditions concerning binary parameters, with the exception of the IMF. This eliminates an important layer of the many uncertain assumptions affecting the predictions of merger detection rates with the gravitational wave detectors aLIGO/aVirgo.

  19. Nucleosynthesis: a field with still many open nuclear physics questions

    SciTech Connect

    Goriely, S.

    2010-06-01

    Stellar nucleosynthesis is a vastly interdisciplinary field. There is a large number of different problems invoked calling for a variety of different and complementary research fields. Impressive progress has been made for the last decades in the various fields related to nucleosynthesis, especially in experimental and theoretical nuclear physics, as well as in ground-based or space astronomical observations and astrophysical modellings. In spite of that success, major problems and puzzles remain. The three major nucleosynthesis processes called for to explain the origin of the elements heavier than iron are described and the major pending questions discussed. As far as nuclear physics is concerned, good quality nuclear data is known to be a necessary condition for a reliable modelling of stellar nucleosynthesis. Through some specific examples, the need for further theoretical or experimental developments is also critically discussed in view of their impact on nucleosynthesis predictions.

  20. Ni/S/Cl systematics and the origin of impact-melt glasses in Martian meteorite Elephant Moraine 79001

    NASA Astrophysics Data System (ADS)

    Schrader, Christian M.; Cohen, Barbara A.; Donovan, John J.; Vicenzi, Edward P.

    2016-04-01

    Martian meteorite Elephant Moraine A79001 (EET 79001) has received considerable attention for the unusual composition of its shock melt glass, particularly its enrichment in sulfur relative to the host shergottite. It has been hypothesized that Martian regolith was incorporated into the melt or, conversely, that the S-enrichment stems from preferential melting of sulfide minerals in the host rock during shock. We present results from an electron microprobe study of EET 79001 including robust measurements of major and trace elements in the shock melt glass (S, Cl, Ni, Co, V, and Sc) and minerals in the host rock (Ni, Co, and V). We find that both S and major element abundances can be reconciled with previous hypotheses of regolith incorporation and/or excess sulfide melt. However, trace element characteristics of the shock melt glass, particularly Ni and Cl abundances relative to S, cannot be explained either by the incorporation of regolith or sulfide minerals. We therefore propose an alternative hypothesis whereby, prior to shock melting, portions of EET 79001 experienced acid-sulfate leaching of the mesostasis, possibly groundmass feldspar, and olivine, producing Al-sulfates that were later incorporated into the shock melt, which then quenched to glass. Such activity in the Martian near-surface is supported by observations from the Mars Exploration Rovers and laboratory experiments. Our preimpact alteration model, accompanied by the preferential survival of olivine and excess melting of feldspar during impact, explains the measured trace element abundances better than either the regolith incorporation or excess sulfide melting hypothesis does.

  1. Early Archean spherule beds of possible impact origin from Barberton, South Africa: A detailed mineralogical and geochemical study

    NASA Technical Reports Server (NTRS)

    Koeberl, Christian; Reimold, Wolf Uwe; Boer, Rudolf H.

    1992-01-01

    The Barberton Greenstone belt is a 3.5- to 3.2-Ga-old formation situated in the Swaziland Supergroup near Barberton, northeast Transvaal, South Africa. The belt includes a lower, predominantly volcanic sequence, and an upper sedimentary sequence (e.g., the Fig Tree Group). Within this upper sedimentary sequence, Lowe and Byerly identified a series of different beds of spherules with diameters of around 0.5-2 mm. Lowe and Byerly and Lowe et al. have interpreted these spherules to be condensates of rock vapor produced by large meteorite impacts in the early Archean. We have collected a series of samples from drill cores from the Mt. Morgan and Princeton sections near Barberton, as well as samples taken from underground exposures in the Sheba and Agnes mines. These samples seem much better preserved than the surface samples described by Lowe and Byerly and Lowe et al. Over a scale of just under 30 cm, several well-defined spherule beds are visible, interspaced with shales and/or layers of banded iron formation. Some spherules have clearly been deposited on top of a sedimentary unit because the shale layer shows indentions from the overlying spherules. Although fresher than the surface samples (e.g., spherule bed S-2), there is abundant evidence for extensive alteration, presumably by hydrothermal processes. In some sections of the cores sulfide mineralization is common. For our mineralogical and petrographical studies we have prepared detailed thin sections of all core and underground samples (as well as some surface samples from the S-2 layer for comparison). For geochemical work, layers with thicknesses in the order of 1-5 mm were separated from selected core and underground samples. The chemical analyses are being performed using neutron activation analysis in order to obtain data for about 35 trace elements in each sample. Major elements are being determined by XRF and plasma spectrometry. To clarify the history of the sulfide mineralization, sulfur isotopic

  2. Children's questions: a mechanism for cognitive development.

    PubMed

    Chouinard, Michael M

    2007-01-01

    methodology allowed detailed, veridical analysis of every question asked by the children during their recording sessions. Results indicate that children ask many information-seeking questions and get informative answers. When they do not get an informative response, they keep asking; attention is not enough. Results also indicate that the content of children's questions parallel their conceptual advances, and shift within an exchange and over the course of development to reflect the learning process. So, these data suggest that the components of the IRM are in place and are used by children from very early in development, and the information they seek changes with time. Study 2 asked whether preverbal children who are not yet asking linguistic questions can recruit information via gestures, expressions, and vocalizations, in addition to further investigating the linguistic questions of older children. This study analyzed questions from a cross-sectional diary study, kept by 68 parents of their children's questions (aged 1;0-5;0). Also, this methodology allowed for data collection over a large number of children, a large range of situational contexts, and allows for the collection of low frequency, high-salience events. Results from Study 2 suggest that all of the components of the IRM are in place, and extends these findings down to younger, preverbal children who recruit information using gesture and vocalizations. Study 3 investigated the questions asked in one specific domain, biological knowledge, and examined the impact that different stimulus types have on children's questions. This study gathered data from 112 parent/child dyads (children aged 2, 3, and 4 years) walking through one of three zoos (one with real animals, one with drawings of animals, and one with three-dimensional replicas of animals), looking at the animals together. Results from this study also suggest that all of the components of the IRM are in place from the earliest age, further supporting the

  3. Research Question, Study Design and Continuous Research Education and Training Exercises (CREATE) Program.

    PubMed

    Burt, Tal; Sharma, Pooja; Mittal, Sanjay

    2012-01-01

    The clinical research project starts with identifying the optimal research question, one that is ethical, impactful, feasible, scientifically sound, novel, relevant, and interesting. The project continues with the design of the study to answer the research question. Such design should be consistent with ethical and methodological principles, and make optimal use of resources in order to have the best chances of identifying a meaningful answer to the research question. Physicians and other healthcare providers are optimally positioned to identify meaningful research questions the answer to which could make significant impact on healthcare delivery. The typical medical education curriculum, however, lacks solid training in clinical research. We propose CREATE (Continuous Research Education And Training Exercises) as a peer- and group-based, interactive, analytical, customized, and accrediting program with didactic, training, mentoring, administrative, and professional support to enhance clinical research knowledge and skills among healthcare professionals, promote the generation of original research projects, increase the chances of their successful completion and potential for meaningful impact. The key features of the program are successive intra- and inter-group discussions and confrontational thematic challenges among participating peers aimed at capitalizing on the groups' collective knowledge, experience and skills, and combined intellectual processing capabilities to optimize choice of research project elements and stakeholder decision-making.

  4. Questioning cochlear amplification

    NASA Astrophysics Data System (ADS)

    van der Heijden, Marcel; Versteegh, Corstiaen P. C.

    2015-12-01

    Thirty years ago it was hypothesized that motile processes inject mechanical energy into cochlear traveling waves. This mechanical amplification, alternatively described as negative damping, is invoked to explain both the sensitivity and the nonlinear compression of cochlear responses. There is a recent trend to present cochlear amplification as an established fact, even though the evidence is at most circumstantial and several thorny problems have remained unresolved. We analyze several of these issues, and present new basilar membrane recordings that allowed us to quantify cochlear energy flow. Specifically, we address the following questions: (1) Does auditory sensitivity require narrowband amplification? (2) Has the "RC problem" (lowpass filtering of outer hair cell receptor potential) been resolved? (3) Can OHC motility improve auditory sensitivity? (4) Is there a net power gain between neighboring locations on the basilar membrane? The analyses indicate that mechanical amplification in the cochlea is neither necessary nor useful, and that realizing it by known forms of motility would reduce sensitivity rather than enhance it. Finally, our experimental data show that the peaking of the traveling wave is realized by focusing the acoustic energy rather than amplifying it. (Abbreviations. BM: basilar membrane; CF: characteristic frequency; IHC: inner hair cell; ME: middle ear; MT; mechanotransducer; OHC: outer hair cell; SPL: sound pressure level.)

  5. Cosmic questions: an introduction.

    PubMed

    Primack, J R; Abrams, N E

    2001-12-01

    This introductory talk at the Cosmic Questions conference sponsored by the AAAS summarizes some earlier pictures of the universe and some pictures based on modern physics and cosmology. The uroboros (snake swallowing its tail) is an example of a traditional picture. The Biblical flat-earth picture was very different from the Greek spherical earth-centered picture, which was the standard view until the end of the Middle Ages. Many people incorrectly assume that the Newtonian picture of stars scattered through otherwise empty space is still the prevailing view. Seeing Earth from space shows the power of a new picture. The Hubble Space Telescope can see all the bright galaxies, all the way to the cosmic Dark Ages. We are at the center of cosmic spheres of time: looking outward is looking backward in time. All the matter and energy in the universe can be represented as a cosmic density pyramid. The laws of physics only allow the material objects in the universe to occupy a wedge-shaped region on a diagram of mass versus size. All sizes--from the smallest size scale, the Planck scale, to the entire visible universe--can be represented on the Cosmic Uroboros. There are interesting connections across this diagram, and the human scale lies in the middle.

  6. Impact of Arizona’s SB 1070 Immigration Law on Utilization of Health Care and Public Assistance Among Mexican-Origin Adolescent Mothers and Their Mother Figures

    PubMed Central

    Umaña-Taylor, Adriana J.; Williams, David R.; Harvey-Mendoza, Elizabeth; Jahromi, Laudan B.; Updegraff, Kimberly A.

    2014-01-01

    Objectives. We examined the impact of Arizona’s “Supporting Our Law Enforcement and Safe Neighborhoods Act” (SB 1070, enacted July 29, 2010) on the utilization of preventive health care and public assistance among Mexican-origin families. Methods. Data came from 142 adolescent mothers and 137 mother figures who participated in a quasi-experimental, ongoing longitudinal study of the health and development of Mexican-origin adolescent mothers and their infants (4 waves; March 2007–December 2011). We used general estimating equations to determine whether utilization of preventive health care and public assistance differed before versus after SB 1070’s enactment. Results. Adolescents reported declines in use of public assistance and were less likely to take their baby to the doctor; compared with older adolescents, younger adolescents were less likely to use preventive health care after SB 1070. Mother figures were less likely to use public assistance after SB 1070 if they were born in the United States and if their post–SB 1070 interview was closer to the law’s enactment. Conclusions. Findings suggest that immigration policies such as SB 1070 may contribute to decreases in use of preventive health care and public assistance among high-risk populations. PMID:24354823

  7. Impact of anthropogenic and climatic changes on biomass and diversity of the Central African forests, from local to global scale: original methods for new results

    NASA Astrophysics Data System (ADS)

    Mortier, Frédéric; Gourlet-Fleury, Sylvie; Ouédraogo, Dakis; Picard, Nicolas; Rossi, Vivien

    2014-05-01

    Forests of the Congo Basin, the second most important remaining block of tropical moist forest in the world, are facing increasing anthropogenic pressure and climate change. Understanding the biomass and diversity dynamics under these pressures is one major challenge for African nations and international communities. This talk aims to present original methods to model, infer, and predict growth, biomass and diversity of Central African forests, as well as new results on the impacts of global change on those forests, at various scales. With respect to methods, we will present theoretical frameworks allowing (i) to model growth processes in species-rich ecosystems like tropical rain forests, (ii) to take into account uncertainties in biomass estimation. In terms of results, we will highlight at a local scale, how human activities as well as climatic variations would impact (i) the composition and diversity of forests, (ii) the dynamics of biomass and growth processes. At a global scale, we will demonstrate how environmental filtering controls the above ground biomass. The number of studies are currently increasing over the Congo Basin through several research projects led by our team (CoForTips, DynAfFor) and contributing to various international organization's programs (Cifor, FAO, Comifac, Ofac).

  8. Questions for Music Education Research

    ERIC Educational Resources Information Center

    Jorgensen, Estelle R.

    2008-01-01

    In addressing the question-set "What questions do music education researchers need to address?", an illustrative list of juxtaposed descriptive and normative questions is sketched as follows: What are and should be the dimensions of music education? What are and should be the institutional agencies of music education? What are and should be the…

  9. Improving the Questions Students Ask

    ERIC Educational Resources Information Center

    Donohue-Smith, Maureen

    2006-01-01

    Teachers often tell their classes that "there is no such thing as a stupid question." But this is not completely honest. Questions aren't asked in a vacuum; their intelligence or stupidity depends on a variety of contextual variables. The ideal question is the right one, posed to the right source in the right way at the right time for the right…

  10. The Hermeneutics of Educational Questioning

    ERIC Educational Resources Information Center

    Bingham, Charles

    2005-01-01

    This article looks at the practice of educational questioning using the philosophical hermeneutics of Hans-Georg Gadamer. It first looks at questions and statements from a hermeneutic perspective, demonstrating some of the differences and similarities between the two. It then details Gadamer's notion of the "true question", asking whether it is…

  11. Does Anyone Have Any Questions?

    ERIC Educational Resources Information Center

    Finkelstein, Judith M.; Ritter, Virginia F.

    The purpose of this study was to determine if answering a child's question with a question produces further analytical questioning by the child. A sample of 80 children in nursery-kindergarten, first, second and third grades (ages ranging from 4-9 years) were divided into two groups. An abstract painting by Kandinsky was shown individually to each…

  12. Children Who Question Their Heterosexuality

    ERIC Educational Resources Information Center

    Carver, Priscilla R.; Egan, Susan K.; Perry, David G.

    2004-01-01

    Many gay, lesbian, and bisexual adults report a period of childhood sexual questioning--an uneasy questioning of their heterosexuality brought on by same-sex attractions and motivating same-sex sexual exploration. This article evaluates hypotheses about the correlates, causes, and consequences of childhood sexual questioning. Participants were 182…

  13. Investigations of Human Question Answering.

    ERIC Educational Resources Information Center

    Graesser, Arthur C.

    The development and testing of QUEST, a model of human question answering, are reported. QUEST accounts for answers adults produce for different categories of open-class questions, identifying the information sources associated with the content words in questions. Each information source is organized in a conceptual graph structure. The model…

  14. Postreading Questioning and Middle School Students' Understanding of Literature

    ERIC Educational Resources Information Center

    Liang, Lauren Aimonette; Watkins, Naomi M.; Graves, Michael F.; Hosp, John

    2010-01-01

    The study examined the effectiveness of a "story map," a questioning technique (Beck & McKeown, 1981) for improving students' understanding of literature. Though the story map idea was widely adopted as a student-initiated strategy, the original story map--a teacher-generated, postreading questioning framework--was never empirically tested. This…

  15. Questioning Our Questions: Assessing Question Asking Practices to Evaluate a yPAR Program

    ERIC Educational Resources Information Center

    Grace, Sarah; Langhout, Regina Day

    2014-01-01

    The purpose of this research was to examine question asking practices in a youth participatory action research (yPAR) after school program housed at an elementary school. The research question was: In which ways did the adult question asking practices in a yPAR setting challenge and/or reproduce conventional models of power in educational…

  16. The interplanetary superhighway and the Origins Program

    NASA Technical Reports Server (NTRS)

    Lo, M. W.

    2002-01-01

    The origin of the universe and of life itself have been central to human inquiries since the dawn of consciousness. To develop and use the technologies to answer these timeless and profound questions is the mission of NASA's Origins Program.

  17. The Enigma of the Origin of Round, Deep, Rimed Lakes in the Russian Heartland-Was Lake Smerdyachie Formed During the Impact of an Extraterrestrial Body?

    NASA Astrophysics Data System (ADS)

    Abbott, D. H.; Gusiakov, V. K.; Kiselev, A.; Amelin, I. I.; Breger, D. L.; McCafferty, P.

    2014-12-01

    The heartland of Russia has many enigmatic deep lakes. Shallow lakes have a more obvious origin, perhaps as kettle lakes, oxbow lakes or subsidence features. Deep lakes, particularly round lakes with partial or complete rims are more problematic. Traditionally, round or nearly round lakes with rims are candidates for Holocene age impact structures. The problem is that there are too many such lakes in the Russian heartland- a minimum of 15 deep, round lakes with diameters between 0.2 and 3 km. Even with a possibly increased impact rate during the Holocene, these deep lakes would represent the entire budget of Holocene impacts concentrated in one small region of the Earth. We examine here Lake Smerdyachie, a previously proposed impact lake. Smerdyachie is perfectly round with a raised rim. It has a diameter of about 350 meters and a maximum water depth of over 30 m. The basement at Smerdyachie is at~40 meters depth. It consists of Carboniferous age carbonate rock with fossils of brachiopods, crinoids and gastropods. The overlying material consists of unconsolidated, sand and silt-sized, quartz-rich sediments. We found clasts of brachiopod, crinoid and gastropod-bearing Carboniferous carbonate rock up to 32 cm in diameter on the SE rim of Smerdyachie. These clasts are present over about 1/3 of the total circumference of the lake. We also made panned concentrates of the sediment on the rim. To the NW, the concentrated sediment has a negative magnetic susceptibility (-0.07 to -0.03 cgs units), consistent with a higher concentration of pulverized limestone. To the SE, the sediment has a positive magnetic susceptibility (0.06 to 0.35 cgs units). The areas of positive magnetic susceptibility lie on the SE two-thirds of the rim of the lake. The highest susceptibility value is from the sample taken closest to the lake shoreline on the SE rim. This spatial distribution of susceptibility could mean that there is a higher concentration of iron rich material on the SE side of

  18. Back to the Origin

    PubMed Central

    Evertts, Adam G.

    2012-01-01

    In bacteria, replication is a carefully orchestrated event that unfolds the same way for each bacterium and each cell division. The process of DNA replication in bacteria optimizes cell growth and coordinates high levels of simultaneous replication and transcription. In metazoans, the organization of replication is more enigmatic. The lack of a specific sequence that defines origins of replication has, until recently, severely limited our ability to define the organizing principles of DNA replication. This question is of particular importance as emerging data suggest that replication stress is an important contributor to inherited genetic damage and the genomic instability in tumors. We consider here the replication program in several different organisms including recent genome-wide analyses of replication origins in humans. We review recent studies on the role of cytosine methylation in replication origins, the role of transcriptional looping and gene gating in DNA replication, and the role of chromatin’s 3-dimensional structure in DNA replication. We use these new findings to consider several questions surrounding DNA replication in metazoans: How are origins selected? What is the relationship between replication and transcription? How do checkpoints inhibit origin firing? Why are there early and late firing origins? We then discuss whether oncogenes promote cancer through a role in DNA replication and whether errors in DNA replication are important contributors to the genomic alterations and gene fusion events observed in cancer. We conclude with some important areas for future experimentation. PMID:23634256

  19. Sustained Ocean Observations represent the key to understanding the origins of ocean climate variability and its impact on atmospheric climate (Fridtjof Nansen Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Bryden, Harry L.

    2013-04-01

    Sustained ocean observing programmes with open access to the observations offer remarkable opportunities for understanding the origin of interannual ocean climate variability and its impact on atmospheric climate. Traditionally ocean observations have been exploratory or experimental, usually of short duration and/or limited spatial extent so that we lack long time series of basin-scale ocean conditions except perhaps for SST, which here is considered to be an atmospheric variable that is responding to (rather than causing) ocean variability. An exception in the ocean is the sustained TOGA monitoring of El Nino-Southern Oscillation climate variability in the Pacific over the last 25 years. Now with satellite records of sea surface height and wind stress for the past 20 years, with Argo records of ocean heat and salt content variability down to 2000 m depth for the past 10 years and with basin-scale current monitoring programmes like Rapid (that includes the Florida Straits transport monitoring done since 1980) for the past 9 years, we can begin to examine events in ocean circulation, their effects on upper ocean heat content including sea surface temperature and then their effects on the atmosphere. With a proper observational basis, we can identify the origin of the ocean variability and its subsequent impact on the climate. We illustrate the opportunities by examining an event in the Atlantic meridional overturning circulation in 2009-10 when the overturning was 30% lower than normal. The principal proximate cause of the reduced overturning circulation was an increase in southward mid-ocean thermocline flow accompanied by a reduction in the deep southward flow of Lower North Atlantic Deep Water thereby increasing the gyre circulation at the expense of the overturning circulation. Because the overturning circulation transports a sizeable amount of heat and salt northwards, the reduction in overturning circulation affects upper ocean heat and salinity content

  20. Life, the Universe, and everything—42 fundamental questions

    NASA Astrophysics Data System (ADS)

    Allen, Roland E.; Lidström, Suzy

    2017-01-01

    In The Hitchhiker’s Guide to the Galaxy, by Douglas Adams, the Answer to the Ultimate Question of Life, the Universe, and Everything is found to be 42—but the meaning of this is left open to interpretation. We take it to mean that there are 42 fundamental questions which must be answered on the road to full enlightenment, and we attempt a first draft (or personal selection) of these ultimate questions, on topics ranging from the cosmological constant and origin of the Universe to the origin of life and consciousness.

  1. Eight questions about invasions and ecosystem functioning.

    PubMed

    Strayer, David L

    2012-10-01

    I pose eight questions central to understanding how biological invasions affect ecosystems, assess progress towards answering those questions and suggest ways in which progress might be made. The questions concern the frequency with which invasions affect ecosystems; the circumstances under which ecosystem change is most likely; the functions that are most often affected by invaders; the relationships between changes to ecosystems, communities, and populations; the long-term responses of ecosystems to invasions; interactions between biological invasions and other anthropogenic activities and the difficulty of managing undesirable impacts of non-native species. Some questions have been answered satisfactorily, others require more data and thought, and others might benefit from being reformulated or abandoned. Actions that might speed progress include careful development of trait-based approaches; strategic collection and publication of new data, including more frequent publication of negative results; replacement of expert opinion with hard data where needed; careful consideration of whether questions really need to be answered, especially in cases where answers are being provided for managers and policy-makers; explicit attention to and testing of the domains of theories; integrating invasions better into an ecosystem context; and remembering that our predictive ability is limited and will remain so for the foreseeable future.

  2. Student Moderators in Asynchronous Online Discussion: A Question of Questions

    ERIC Educational Resources Information Center

    Zingaro, Daniel

    2012-01-01

    Much current research exalts the benefits of having students facilitate weekly discussions in asynchronous online courses. This study seeks to add to what is known about student moderation through an analysis of the types of questions students use to spur each discussion. Prior experimental work has demonstrated that the types of questions posed…

  3. Reference Readiness for AV Questions.

    ERIC Educational Resources Information Center

    Drolet, Leon L., Jr.

    1981-01-01

    Reviews 50 reference tools which librarians can use to answer almost any audiovisual question including queries on trivia, equipment selection, biographical information, and motion picture ratings. (LLS)

  4. Origin and Health Impacts of Emissions of Toxic By-Products and Fine Particles from Combustion and Thermal Treatment of Hazardous Wastes and Materials

    PubMed Central

    Cormier, Stephania A.; Lomnicki, Slawo; Backes, Wayne; Dellinger, Barry

    2006-01-01

    High-temperature, controlled incineration and thermal treatment of contaminated soils, sediments, and wastes at Superfund sites are often preferred methods of remediation of contaminated sites under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 and related legislation. Although these methods may be executed safely, formation of toxic combustion or reaction by-products is still a cause of concern. Emissions of polycyclic aromatic hydrocarbons (PAHs); chlorinated hydrocarbons (CHCs), including polychlorinated dibenzo-p-dioxins and dibenzofurans; and toxic metals (e.g., chromium VI) have historically been the focus of combustion and health effects research. However, fine particulate matter (PM) and ultrafine PM, which have been documented to be related to cardiovascular disease, pulmonary disease, and cancer, have more recently become the focus of research. Fine PM and ultrafine PM are effective delivery agents for PAHs, CHCs, and toxic metals. In addition, it has recently been realized that brominated hydrocarbons (including brominated/chlorinated dioxins), redox-active metals, and redox-active persistent free radicals are also associated with PM emissions from combustion and thermal processes. In this article, we discuss the origin of each of these classes of pollutants, the nature of their association with combustion-generated PM, and the mechanisms of their known and potential health impacts. PMID:16759977

  5. Questioning Questions: Elementary Teachers' Adaptations of Investigation Questions Across the Inquiry Continuum

    NASA Astrophysics Data System (ADS)

    Biggers, Mandy

    2017-01-01

    Questioning is a central practice in science classrooms. However, not every question translates into a "good" science investigation. Questions that drive science investigations can be provided by many sources including the teacher, the curriculum, or the student. The variations in the source of investigation questions were explored in this study. A dataset of 120 elementary science classroom videos and associated lesson plans from 40 elementary teachers (K-5) across 21 elementary school campuses were scored on an instrument measuring the amount of teacher-direction or student-direction of the lessons' investigation questions. Results indicated that the investigation questions were overwhelmingly teacher directed in nature, with no opportunities for students to develop their own questions for investigation. This study has implications for researchers and practitioners alike, calling attention to the teacher-directed nature of investigation questions in existing science curriculum materials, and the need for teacher training in instructional strategies to adapt their existing curriculum materials across the continuum of teacher-directed and student-directed investigation questions. Teachers need strategies for adapting the teacher-directed questions provided in their existing curriculum materials in order to allow students the opportunity to engage in this essential scientific practice.

  6. Using Seen Examination Questions in Economics: An Evaluation

    ERIC Educational Resources Information Center

    Reimann, Nicola; Robson, Martin

    2013-01-01

    This paper presents a detailed quantitative analysis of the use of seen questions within examinations in Economics option modules at one UK university. 4622 marks for seen and unseen questions awarded over a period of three years were analysed; the impact of personal characteristics was analysed using a sub-sample. It was found that the number of…

  7. Update on Medical Practices that should be questioned in 2015

    PubMed Central

    Morgan, Daniel J.; Dhruva, Sanket S.; Wright, Scott M.; Korenstein, Deborah

    2016-01-01

    Importance Overuse of medical care, consisting primarily of overdiagnosis and overtreatment, is a common clinical problem. Objective To identify and highlight articles published in 2014 that are most likely to impact overuse, organized into the categories of overdiagnosis, overtreatment, and methods to avoid overuse. These manuscripts were reviewed and interpreted for their importance to clinical medicine. Evidence Review A structured review of English-language articles on PubMed published in 2014 and review of tables of contents of relevant journals to identify potential articles that related to medical overuse in adults. Findings We reviewed 910 articles, of which 440 addressed overuse. Of these, 104 were deemed most relevant based on the presentation of original data, quality of methodology, magnitude of clinical impact, and the number of patients potentially affected. The 10 most influential articles were selected by author consensus using the same criteria. Findings included lack of benefit for screening pelvic examinations (positive predictive value <5%), carotid artery and thyroid ultrasounds. Harms of cancer screening included unnecessary surgery and complications. Head CT scans were an overused diagnostic test (4% with clinically significant findings) and overtreatment included acetaminophen for low back pain, prolonged opioid use after surgery (3% of patients on >90 days), perioperative aspirin, medications to increase HDL, and stenting for renal artery stenosis. Conclusions and Relevance Many common medical practices should be reconsidered. It is hoped that our review promotes reflection on these 10 articles and lead to questioning other non-evidence based practices. PMID:26551354

  8. Questions Dog Design of Tests

    ERIC Educational Resources Information Center

    Gewertz, Catherine

    2012-01-01

    On the verge of signing a contract to help design assessments for the common standards, ACT Inc. has withdrawn from the project amid conflict-of-interest questions sparked by its own development of a similar suite of tests. Even though it involves only a small subcontract, the move by the Iowa-based test-maker, and the questions from the state…

  9. Asking Research Questions: Theoretical Presuppositions

    ERIC Educational Resources Information Center

    Tenenberg, Josh

    2014-01-01

    Asking significant research questions is a crucial aspect of building a research foundation in computer science (CS) education. In this article, I argue that the questions that we ask are shaped by internalized theoretical presuppositions about how the social and behavioral worlds operate. And although such presuppositions are essential in making…

  10. Test Pool Questions, Area III.

    ERIC Educational Resources Information Center

    Sloan, Jamee Reid

    This manual contains multiple choice questions to be used in testing students on nurse training objectives. Each test includes several questions covering each concept. The concepts in section A, medical surgical nursing, are diseases of the following systems: musculoskeletal; central nervous; cardiovascular; gastrointestinal; urinary and male…

  11. Answering Your Questions about AIDS.

    ERIC Educational Resources Information Center

    Kalichman, Seth C.

    This book focuses on AIDS education and answers 350 commonly asked questions about Human Immunodeficiency Virus (HIV) and Acquired Immune Deficiency Syndrome (AIDS) taken from questions addressed to two major urban AIDS hotlines (Milwaukee, Wisconsin, and Houston, Texas). Chapter 1, "HIV - The Virus That Causes AIDS," discusses: the HIV…

  12. Toward Automated Consumer Question Answering: Automatically Separating Consumer Questions from Professional Questions in the Healthcare Domain

    PubMed Central

    Liu, Feifan; Antieau, Lamont D.; Yu, Hong

    2011-01-01

    Objective Both healthcare professionals and healthcare consumers have information needs that can be met through the use of computers, specifically via medical question answering systems. However, the information needs of both groups are different in terms of literacy levels and technical expertise, and an effective question answering system must be able to account for these differences if it is to formulate the most relevant responses for users from each group. In this paper, we propose that a first step toward answering the queries of different users is automatically classifying questions according to whether they were asked by healthcare professionals or consumers. Design We obtained two sets of consumer questions (~10,000 questions in total) from Yahoo answers. The professional questions consist of two question collections: 4654 point-of-care questions (denoted as PointCare) obtained from interviews of a group of family doctors following patient visits and 5378 questions from physician practices through professional online services (denoted as OnlinePractice). With more than 20,000 questions combined, we developed supervised machine-learning models for automatic classification between consumer questions and professional questions. To evaluate the robustness of our models, we tested the model that was trained on the Consumer-PointCare dataset on the Consumer-OnlinePractice dataset. We evaluated both linguistic features and statistical features and examined how the characteristics in two different types of professional questions (PointCare vs. OnlinePractice) may affect the classification performance. We explored information gain for feature reduction and the back-off linguistic category features. Results 10-fold cross-validation results showed the best F1-measure of 0.936 and 0.946 on Consumer-PointCare and Consumer-OnlinePractice respectively, and the best F1-measure of 0.891 when testing the Consumer-PointCare model on the Consumer-OnlinePractice dataset

  13. The Value Question in Metaphysics.

    PubMed

    Kahane, Guy

    2012-07-01

    Much seems to be at stake in metaphysical questions about, for example, God, free will or morality. One thing that could be at stake is the value of the universe we inhabit-how good or bad it is. We can think of competing philosophical positions as describing possibilities, ways the world might turn out to be, and to which value can be assigned. When, for example, people hope that God exists, or fear that we do not possess free will, they express attitudes towards these possibilities, attitudes that presuppose answers to questions about their comparative value. My aim in this paper is to distinguish these evaluative questions from related questions with which they can be confused, to identify structural constraints on their proper pursuit, and to address objections to their very coherence. Answers to such evaluative questions offer one measure of the importance of philosophical disputes.

  14. The Value Question in Metaphysics

    PubMed Central

    Kahane, Guy

    2012-01-01

    Much seems to be at stake in metaphysical questions about, for example, God, free will or morality. One thing that could be at stake is the value of the universe we inhabit—how good or bad it is. We can think of competing philosophical positions as describing possibilities, ways the world might turn out to be, and to which value can be assigned. When, for example, people hope that God exists, or fear that we do not possess free will, they express attitudes towards these possibilities, attitudes that presuppose answers to questions about their comparative value. My aim in this paper is to distinguish these evaluative questions from related questions with which they can be confused, to identify structural constraints on their proper pursuit, and to address objections to their very coherence. Answers to such evaluative questions offer one measure of the importance of philosophical disputes. PMID:23024399

  15. Do clinicians use more question marks?

    PubMed Central

    Otte, Willem M; van’t Klooster, Maryse A; van Diessen, Eric; Leijten, Frans SS; Sander, Josemir W

    2015-01-01

    Objective To quantify the use of question marks in titles of published studies. Design and setting Literature review. Participants All Pubmed publications between 1 January 2013 and 31 December 2013 with an available abstract. Papers were classified as being clinical when the search terms clin*, med* or patient* were found anywhere in the paper’s title, abstract or the journal’s name. Other papers were considered controls. As a verification, clinical journals were compared to non-clinical journals in two different approaches. Also, 50 highest impact journals were explored for publisher group dependent differences. Main outcome measure Total number of question marks in titles. Results A total of 368,362 papers were classified as clinical and 596,889 as controls. Clinical papers had question marks in 3.9% (95% confidence interval 3.8–4.0%) of titles and other papers in 2.3% (confidence interval 2.3–2.3%; p < 0.001). These findings could be verified for clinical journals compared to non-clinical journals. Different percentages between four publisher groups were found (p < 0.01). Conclusion We found more question marks in titles of clinical papers than in other papers. This could suggest that clinicians often have a question-driven approach to research and scientists in more fundamental research a hypothesis-driven approach. An alternative explanation is that clinicians like catchy titles. Publishing groups might have pro- and anti-question mark policies. PMID:26085937

  16. Impact and safety of endoscopic ultrasound guided fine needle aspiration on patients with cirrhosis and pyrexia of unknown origin in India

    PubMed Central

    Choudhary, Narendra; Bansal, Rinkesh Kumar; Puri, Rajesh; Singh, Rajiv Ranjan; Nasa, Mukesh; Shah, Vinit; Sarin, Haimanti; Guleria, Mridula; Saigal, Sanjiv; Saraf, Neeraj; Sud, Randhir; Soin, Arvinder S.

    2016-01-01

    Background and aims: Etiologic diagnosis of pyrexia of unknown origin is important in patients with cirrhosis for optimal management and to prevent flare up of infectious disease after liver transplantation. However, there is very limited literature available on this subject. The present study aimed to examine the safety and impact of endoscopic ultrasound (EUS) guided fine needle aspiration (FNA) in patients with cirrhosis. Methods: The study was conducted between January 2014 and January 2016 at a tertiary care center. A total of 50 (47 lymph nodes, 3 adrenal) EUS guided FNAs were performed in 46 patients. Data are presented as median (25 – 75 IQR). Results: The study included 46 patients (40 males) whose mean age was 47.9 ± 11.1 (SD) years; mean Child-Turcotte-Pugh (CTP) score and mean MELD (Model for End-Stage Liver Disease) score were 10 (8 – 11) and 18 (12 – 20), respectively. The Child Pugh class was A in 4, B in 14, and C in 28 (including three patients with adrenal FNAs). Indications for FNA were pyrexia of unknown origin and lymphadenopathy on CT imaging. The cytopathological diagnoses were metastatic disease in 1 (adrenal), granulomatous change in 10 (6 positive with acid fast bacilli stain), histoplasmosis in three (two adrenals, one lymph node), 32 lymph nodes were reactive and four lymph node FNAs showed inadequate cellularity. The pathologic nodes had significantly lower long-to-short axis ratio [1.25 (1.09 – 1.28) versus 1.46 (1.22 – 1.87), P = 0.020]; a higher proportion of hypoechoic echotexture (5 versus 3, P = 0.017), and sharply defined borders (4 versus 2, P = 0.029). Complications included mild hepatic encephalopathy related to sedation in two patients with Child’s C status. Conclusion: EUS guided FNA is safe in patients with cirrhosis and modified the management in 14/46 (30.4 %) patients. PMID:27652300

  17. A Preliminary Investigation of the Yallalie Basin: A Buried 15 KM Diameter Structure of Possible Impact Origin in the Perth Basin, Western Australia

    NASA Astrophysics Data System (ADS)

    Dentith, M. C.; Bevan, A. W. R.; McInerney, K. B.

    1992-07-01

    some surface expression. A broad depression approximately 120 m deep is centered on Yallalie Well and is bounded to the west and north by a marked "rim." The area is characterized by a radial pattern of drainage that flows into the depression and which is gradually exhuming the buried structure. A southerly flowing stream drains the depression and has breached the "rim" to the south. Evidence for impact at Yallalie: Quartz grains taken from the core at a depth of 430-460 m in the Yallalie 1 well show widesprad development of prismatic cleavage fractures and irregular, slightly curved planes formed by brittle fracture. Quartz grains from a depth of 150-180 m in the well are essentially undeformed (McInerney, 1991). However, multiple sets of closely spaced planar features in quartz, characteristic of highly shocked rocks, have yet to be observed in core material from the Yallalie structure. Nevertheless, the morphology of the Yallalie structure determined from geophysical data suggests strongly that it is of impact origin. Work is continuing on the core material to search for diagnostic shock-metamorhic effects, and to constrain the age of the structure. References Cockbain A. E. (1990) In Geology and Mineral Resources of Western Australia, Western Australia Geological Survey, Memoir 3, pp. 514-516. Dence M. R., Grieve R. A. F., and Robertson P. B. (1977) In Impact and Explosion Cratering (eds. D. J. Roddy, R. O. Pepin, and R. B. Merrill), Pergamon Press, pp. 247-275. McInerney K. B. (1991) Honors Thesis (unpublished), University of Western Australia.

  18. Measuring injury risk factors: question reliability in a statewide sample

    PubMed Central

    Koziol-McLain, J.; Brand, D.; Morgan, D.; Leff, M.; Lowenstein, S.

    2000-01-01

    Background—Recently (1996–98), Colorado added 15 questions pertaining to injury related risks and behaviors to the behavioral risk factor surveillance system (BRFSS). Questions addressed bicycle helmet use, traffic crashes, exposure to violence, suicidal behavior, and gun storage. Objective—To measure the test-retest reliability of these injury related questions. Methods—Of 330 BRFSS participants, 229 (69%) were called a second time and reasked nine selected injury questions. Retests were completed 7–28 days after the original interview. Results—Test-retest agreement was very high (κ >0.80) for bicycle helmet use, domestic police visits, and gun ownership. All other injury risk questions had substantial agreement (κ >0.60). Conclusions—The injury related questions added to the Colorado BRFSS have high test-retest reliability. PMID:10875674

  19. Phrasal Paraphrase Based Question Reformulation for Archived Question Retrieval.

    PubMed

    Zhang, Yu; Zhang, Wei-Nan; Lu, Ke; Ji, Rongrong; Wang, Fanglin; Liu, Ting

    2013-01-01

    Lexical gap in cQA search, resulted by the variability of languages, has been recognized as an important and widespread phenomenon. To address the problem, this paper presents a question reformulation scheme to enhance the question retrieval model by fully exploring the intelligence of paraphrase in phrase-level. It compensates for the existing paraphrasing research in a suitable granularity, which either falls into fine-grained lexical-level or coarse-grained sentence-level. Given a question in natural language, our scheme first detects the involved key-phrases by jointly integrating the corpus-dependent knowledge and question-aware cues. Next, it automatically extracts the paraphrases for each identified key-phrase utilizing multiple online translation engines, and then selects the most relevant reformulations from a large group of question rewrites, which is formed by full permutation and combination of the generated paraphrases. Extensive evaluations on a real world data set demonstrate that our model is able to characterize the complex questions and achieves promising performance as compared to the state-of-the-art methods.

  20. Phrasal Paraphrase Based Question Reformulation for Archived Question Retrieval

    PubMed Central

    Lu, Ke; Ji, Rongrong; Wang, Fanglin; Liu, Ting

    2013-01-01

    Lexical gap in cQA search, resulted by the variability of languages, has been recognized as an important and widespread phenomenon. To address the problem, this paper presents a question reformulation scheme to enhance the question retrieval model by fully exploring the intelligence of paraphrase in phrase-level. It compensates for the existing paraphrasing research in a suitable granularity, which either falls into fine-grained lexical-level or coarse-grained sentence-level. Given a question in natural language, our scheme first detects the involved key-phrases by jointly integrating the corpus-dependent knowledge and question-aware cues. Next, it automatically extracts the paraphrases for each identified key-phrase utilizing multiple online translation engines, and then selects the most relevant reformulations from a large group of question rewrites, which is formed by full permutation and combination of the generated paraphrases. Extensive evaluations on a real world data set demonstrate that our model is able to characterize the complex questions and achieves promising performance as compared to the state-of-the-art methods. PMID:23805178

  1. Questioning ORACLE: An Assessment of ORACLE's Analysis of Teachers' Questions and [A Comment on "Questioning ORACLE"].

    ERIC Educational Resources Information Center

    Scarth, John; And Others

    1986-01-01

    Analysis of teachers' questions, part of the ORACLE (Observation Research and Classroom Learning Evaluation) project research, is examined in detail. Scarth and Hammersley argue that the rules ORACLE uses for identifying different types of questions involve levels of ambiguity and inference that threaten reliability and validity of the study's…

  2. Original Misunderstanding

    ERIC Educational Resources Information Center

    Holtzman, Alexander

    2009-01-01

    Humorist Josh Billings quipped, "About the most originality that any writer can hope to achieve honestly is to steal with good judgment." Billings was harsh in his view of originality, but his critique reveals a tension faced by students every time they write a history paper. Research is the essence of any history paper. Especially in high school,…

  3. Climate Leadership Awards Frequent Questions

    EPA Pesticide Factsheets

    Provides answers to frequently asked questions regarding the Climate Leadership Awards, sponsored by EPA's Center for Corporate Climate Leadership with co-sponsorship from the Center for Climate and Energy Solutions and The Climate Registry.

  4. Twenty Questions about Student Errors.

    ERIC Educational Resources Information Center

    Fisher, Kathleen M.; Lipson, Joseph Isaac

    1986-01-01

    Discusses the value of studying errors made by students in the process of learning science. Addresses 20 research questions dealing with student learning errors. Attempts to characterize errors made by students and clarify some terms used in error research. (TW)

  5. Interview Questions with Bentham Scientific

    NASA Technical Reports Server (NTRS)

    Mather, John C.

    2013-01-01

    John Mather answers questions for an interview for the Bentham Science Newsletter. He covers topics ranging from his childhood, his professional career and his thoughts on research, technology and today's scientists and engineers.

  6. Frequent Questions about TSCA CBI

    EPA Pesticide Factsheets

    General Questions and Answers Concerning Confidential Business Information (CBI) Provisions of the Toxic Substances Control Act (TSCA), as amended by the Frank R. Lautenberg Chemical Safety for the 21st Century Act

  7. Solar physics: Dynamo theory questioned

    NASA Astrophysics Data System (ADS)

    Charbonneau, Paul

    2016-07-01

    Observations of X-ray emission -- a diagnostic tool for the mechanisms driving stellar magnetic fields -- from four cool stars call into question accepted models of magnetic-field generation in the Sun and stars. See Letter p.526

  8. Birds: Old Questions and New.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    2002-01-01

    Discusses questions such as how birds fly and the meaning of bird songs. Explains the relationship between birds and ecological activism and points out the excitement in research and observation of birds. (Contains 34 references.) (YDS)

  9. HPV Vaccine - Questions and Answers

    MedlinePlus

    ... and Media Resources News Newsletters Events Redirect for HPV Vaccine FAQ Recommend on Facebook Tweet Share Compartir ... to the address below. http://www.cdc.gov/hpv/parents/questions-answers.html File Formats Help: How ...

  10. Resource Classification for Medical Questions

    PubMed Central

    Roberts, Kirk; Rodriguez, Laritza; Shooshan, Sonya E.; Demner-Fushman, Dina

    2016-01-01

    We present an approach for manually and automatically classifying the resource type of medical questions. Three types of resources are considered: patient-specific, general knowledge, and research. Using this approach, an automatic question answering system could select the best type of resource from which to consider answers. We first describe our methodology for manually annotating resource type on four different question corpora totaling over 5,000 questions. We then describe our approach for automatically identifying the appropriate type of resource. A supervised machine learning approach is used with lexical, syntactic, semantic, and topic-based feature types. This approach is able to achieve accuracies in the range of 80.9% to 92.8% across four datasets. Finally, we discuss the difficulties encountered in both manual and automatic classification of this challenging task. PMID:28269901

  11. Frequent Questions About Universal Waste

    EPA Pesticide Factsheets

    Frequent questions such as Who is affected by the universal waste regulations? What is “mercury-containing equipment”? How are waste batteries managed under universal waste? How are waste pesticides managed under universal waste?

  12. Resource Classification for Medical Questions.

    PubMed

    Roberts, Kirk; Rodriguez, Laritza; Shooshan, Sonya E; Demner-Fushman, Dina

    2016-01-01

    We present an approach for manually and automatically classifying the resource type of medical questions. Three types of resources are considered: patient-specific, general knowledge, and research. Using this approach, an automatic question answering system could select the best type of resource from which to consider answers. We first describe our methodology for manually annotating resource type on four different question corpora totaling over 5,000 questions. We then describe our approach for automatically identifying the appropriate type of resource. A supervised machine learning approach is used with lexical, syntactic, semantic, and topic-based feature types. This approach is able to achieve accuracies in the range of 80.9% to 92.8% across four datasets. Finally, we discuss the difficulties encountered in both manual and automatic classification of this challenging task.

  13. Extraction of Questions Behind Messages

    NASA Astrophysics Data System (ADS)

    Matsumura, Naohiro; Kawahara, Daisuke; Okamoto, Masashi; Kurohashi, Sadao; Nishida, Toyoaki

    To overcome the limitation of conventional text-mining approaches in which frequent patterns of word occurrences are to be extracted to understand obvious user needs, this paper proposes an approach to extracting questions behind messages to understand potential user needs. We first extract characteristic case frames by comparing the case frames constructed from target messages with the ones from 25M sentences in the Web and 20M sentences in newspaper articles of 20 years. Then we extract questions behind messages by transforming the characteristic case frames into interrogative sentences based on new information and old information, i.e., replacing new information with WH-question words. The proposed approach is, in other words, a kind of classification of word occurrence pattern. Qualitative evaluations of our preliminary experiments suggest that extracted questions show problem consciousness and alternative solutions -- all of which help to understand potential user needs.

  14. Questions Students Ask: Beta Decay.

    ERIC Educational Resources Information Center

    Koss, Jordan; Hartt, Kenneth

    1988-01-01

    Answers a student's question about the emission of a positron from a nucleus. Discusses the problem from the aspects of the uncertainty principle, beta decay, the Fermi Theory, and modern physics. (YP)

  15. Folic Acid Questions and Answers

    MedlinePlus

    ... Controls NCBDDD Cancel Submit Search The CDC Folic Acid Note: Javascript is disabled or is not supported ... please visit this page: About CDC.gov . Folic Acid Homepage Facts Quiz Frequently Asked Questions General Information ...

  16. Henipaviruses-unanswered questions of lethal zoonoses.

    PubMed

    Field, Hume; Kung, Nina

    2011-12-01

    The highly lethal Hendra and Nipah viruses have been described for little more than a decade, yet within that time have been aetiologically associated with major livestock and human health impacts, albeit on a limited scale. Do these emerging pathogens pose a broader threat, or are they inconsequential 'viral chatter'. Given their lethality, and the evident multi-generational human-to-human transmission associated with Nipah virus in Bangladesh, it seems prudent to apply the precautionary principle. While much is known of their clinical, pathogenic and epidemiologic features in livestock species and humans, a number of fundamental questions regarding the relationship between the viruses, their natural fruit-bat host and the environment remain unanswered. In this paper, we pose and probe these questions in context, and offer perspectives based primarily on our experience with Hendra virus in Australia, augmented with Nipah virus parallels.

  17. Questionable research practices among italian research psychologists

    PubMed Central

    Wicherts, Jelte M.; Veldkamp, Coosje L. S.; Albiero, Paolo; Cubelli, Roberto

    2017-01-01

    A survey in the United States revealed that an alarmingly large percentage of university psychologists admitted having used questionable research practices that can contaminate the research literature with false positive and biased findings. We conducted a replication of this study among Italian research psychologists to investigate whether these findings generalize to other countries. All the original materials were translated into Italian, and members of the Italian Association of Psychology were invited to participate via an online survey. The percentages of Italian psychologists who admitted to having used ten questionable research practices were similar to the results obtained in the United States although there were small but significant differences in self-admission rates for some QRPs. Nearly all researchers (88%) admitted using at least one of the practices, and researchers generally considered a practice possibly defensible if they admitted using it, but Italian researchers were much less likely than US researchers to consider a practice defensible. Participants’ estimates of the percentage of researchers who have used these practices were greater than the self-admission rates, and participants estimated that researchers would be unlikely to admit it. In written responses, participants argued that some of these practices are not questionable and they have used some practices because reviewers and journals demand it. The similarity of results obtained in the United States, this study, and a related study conducted in Germany suggest that adoption of these practices is an international phenomenon and is likely due to systemic features of the international research and publication processes. PMID:28296929

  18. Disability Discrimination and Obesity: The Big Questions?

    PubMed

    Flint, Stuart W; Snook, Jeremé

    2015-12-01

    Obesity discrimination in employment and recruitment has become a topic of focus for research examination with increasing reports of discrimination by colleagues and managers. Whilst a limited number of legal cases have emerged, disability law is consulted in line with the expectation of anti-discriminatory practices at work. In line with disability law, whether obesity is defined as a disability or not has an impact on the outcome of a court ruling. Ambiguity when defining obesity through either the medical or social model means there are many questions that remain unanswered which might lead to inconsistency in court rulings.

  19. [Validation of the questionnaire for adolescents concerning ailments of lumbosacral region. Part II: reliability of questions about risk factors].

    PubMed

    Baczkiewicz, Maja; Demczuk-Włodarczyk, Ewa

    2011-01-01

    The second part of the series of articles presents the reliability testing results of questions concerning factors that could influence or originate the symptoms of low back pain (LBP). The questions are a part of the questionnaire designed for pupils aged 13-18. 124 persons aged 13-17 were tested. The questionannaires were filled in twice by every pupil in no more than 7-day period, and then the answers were compared according to the test-retest method. The questions concerning risk factors were about: the intensive growth period, chronic diseases, the medical diagnosis of LBP, concomitant faulty posture, sport training and leisure time physical activities, leisure time spent sitting, possible nutritional deficiencies, the amount of sleep, the impact of lifting and dislike for school. Results that were obtained in the process of testing indicated that reasoning would be invalid if based on questions about sports (45% repeatable answers), about leisure time physical activities (Polish version of the leisure time exercise questionnaire of Godin and Shepard--correlation for the Godin and Shepard index was 0,29) and about intensive growth period (small number of valid responses indicates that the question is incomprehensible for adolescents). The rest of questions were found acceptably reliable.

  20. Cosmic Origin and Theology of the Revelation

    NASA Astrophysics Data System (ADS)

    Guijarro, José Francisco

    2007-04-01

    All along cultural history man has asked himself about the origin of man, the origin of life ante the origin of the cosmos. Regarding the question about the origin of the cosmos, any theological research must settle before any other goal the question of its language: what we understand as scientific, mythical or theological language. The biblical texts on Creation are analyzed in their historical, cultural and theological context. It is concluded that the fundamental religious meanings of the biblical texts are not in opposition to scientific interpretation of cosmic origin.

  1. Quantifying the origins of life on a planetary scale

    PubMed Central

    Scharf, Caleb; Cronin, Leroy

    2016-01-01

    A simple, heuristic formula with parallels to the Drake Equation is introduced to help focus discussion on open questions for the origins of life in a planetary context. This approach indicates a number of areas where quantitative progress can be made on parameter estimation for determining origins of life probabilities, based on constraints from Bayesian approaches. We discuss a variety of “microscale” factors and their role in determining “macroscale” abiogenesis probabilities on suitable planets. We also propose that impact ejecta exchange between planets with parallel chemistries and chemical evolution could in principle amplify the development of molecular complexity and abiogenesis probabilities. This amplification could be very significant, and both bias our conclusions about abiogenesis probabilities based on the Earth and provide a major source of variance in the probability of life arising in planetary systems. We use our heuristic formula to suggest a number of observational routes for improving constraints on origins of life probabilities. PMID:27382156

  2. Quantifying the origins of life on a planetary scale.

    PubMed

    Scharf, Caleb; Cronin, Leroy

    2016-07-19

    A simple, heuristic formula with parallels to the Drake Equation is introduced to help focus discussion on open questions for the origins of life in a planetary context. This approach indicates a number of areas where quantitative progress can be made on parameter estimation for determining origins of life probabilities, based on constraints from Bayesian approaches. We discuss a variety of "microscale" factors and their role in determining "macroscale" abiogenesis probabilities on suitable planets. We also propose that impact ejecta exchange between planets with parallel chemistries and chemical evolution could in principle amplify the development of molecular complexity and abiogenesis probabilities. This amplification could be very significant, and both bias our conclusions about abiogenesis probabilities based on the Earth and provide a major source of variance in the probability of life arising in planetary systems. We use our heuristic formula to suggest a number of observational routes for improving constraints on origins of life probabilities.

  3. Open questions for Alzheimer's disease immunotherapy.

    PubMed

    Golde, Todd E

    2014-01-01

    Perhaps more definitively than any other class of novel Alzheimer's disease (AD) therapy, pre-clinical studies in mouse models of amyloid β (Aβ) deposition have established the disease-modifying potential of anti-Aβ immunotherapy. Despite disappointing results to date from anti-Aβ immunotherapy therapeutic trials, there is continued hope that such immunotherapies, especially if used in the preclinical stages, could prove to be the first disease-modifying therapies available for AD. The general optimism that Aβ-targeting and emerging tau-targeting immunotherapies may prove to be disease modifying is tempered by many unanswered questions regarding these therapeutic approaches, including but not limited to i) lack of precise understanding of mechanisms of action, ii) the factors that regulate antibody exposure in the brain, iii) the optimal target epitope, and iv) the mechanisms underlying side effects. In this review I discuss how answering these and other questions could increase the likelihood of therapeutic success. As passive immunotherapies are also likely to be extremely expensive, I also raise questions relating to cost-benefit of biologic-based therapies for AD that could limit future impact of these therapies by limiting access due to economic constraints.

  4. Explaining Errors in Children's Questions

    ERIC Educational Resources Information Center

    Rowland, Caroline F.

    2007-01-01

    The ability to explain the occurrence of errors in children's speech is an essential component of successful theories of language acquisition. The present study tested some generativist and constructivist predictions about error on the questions produced by ten English-learning children between 2 and 5 years of age. The analyses demonstrated that,…

  5. Teaching Ideas: Building Questioning Skills.

    ERIC Educational Resources Information Center

    Felton, Randall G.; Allen, Rodney F.

    1986-01-01

    This exercise shows how to turn the expository treatment of a topic or event into a mystery or puzzling situation that students are asked to solve. Once a puzzle is presented, students may pose only questions that can be answered yes or no. Three sample lessons are included to illustrate the process. (JDH)

  6. Four Questions to Ask Yourself

    ERIC Educational Resources Information Center

    Abilock, Debbie, Ed.

    2007-01-01

    One's commitment to intellectual freedom is manifested not just in the creation of a strong and clear selection policy or the celebration of Banned Books Week but by his or her willingness to examine his or her practices openly with others. In this article, the author proposes four questions to explore in one's teaching and in professional…

  7. Instance-Based Question Answering

    DTIC Science & Technology

    2006-12-01

    answer clustering, composition, and scoring. Moreover, with the effort dedicated to improving monolingual system performance, system parameters are...text collections: document type, manual or automatic annotations (if any), and stylistic and notational differences in technical terms. Monolingual ...forum in which cross language retrieval systems and question answering systems are tested for various Eu- ropean languages. The CLEF QA monolingual task

  8. Constructivism and Objectivism: Additional Questions

    ERIC Educational Resources Information Center

    Meltzer, Edmund S.

    2006-01-01

    In past issues of "The Educational Forum," David Elkind (2004; 2005) and Jamin Carson (2005) have engaged in a dialogue about constructivism and objectivism as viable philosophies of education. In this issue, yet another author joins in the discussion by questioning the role of science and religion in objectivism.

  9. Questionable Methods in Alcoholism Research.

    ERIC Educational Resources Information Center

    Koocher, Gerald P.

    1991-01-01

    Alcoholism research paradigms that use substantial cash incentives to attract participants and that call for alcoholics to consume ethanol in laboratory raise ethical questions. When using such methods, investigators should be obligated to discuss risk-benefit rationales and detail precautionary behaviors to protect participants. Discussion of…

  10. Addressing Phonological Questions with Ultrasound

    ERIC Educational Resources Information Center

    Davidson, Lisa

    2005-01-01

    Ultrasound can be used to address unresolved questions in phonological theory. To date, some studies have shown that results from ultrasound imaging can shed light on how differences in phonological elements are implemented. Phenomena that have been investigated include transitional schwa, vowel coalescence, and transparent vowels. A study of…

  11. What Children Learn from Questioning

    ERIC Educational Resources Information Center

    Harris, Paul

    2015-01-01

    Research shows that young children ask a multitude of why and how questions. And when they do, they're not simply trying to get adult attention; instead, they're actively seeking information. In this article, Paul Harris describes the findings of a number of research analyses based on extensive transcripts of children's natural speech. Some of the…

  12. Eight Questions for Better Lessons

    ERIC Educational Resources Information Center

    Kriegel, Otis

    2016-01-01

    In this article, veteran educator Otis Kriegel provides eight questions that teachers can ask themselves as they create or tweak lesson plans. With practical, straightforward advice, Kriegel suggests that teachers be mindful of who their audience is, how much students already know, and what materials they'll need. He also urges teachers to…

  13. Ten Practical Questions about Branding

    ERIC Educational Resources Information Center

    Moore, Robert M.; Rattenbury, Jeanne

    2004-01-01

    "Marketing" and "branding" were once considered dirty words on campus but faculty, staff, and board members now appreciate the value of getting their message out and managing their reputation. The question is not so much whether to invest, but when, how, and most important, what's the return on investment? A roundtable of accomplished marketing…

  14. The Geography of Virtual Questioning

    ERIC Educational Resources Information Center

    Mon, Lorri; Bishop, Bradley Wade; McClure, Charles R.; McGilvray, Jessica; Most, Linda; Milas, Theodore Patrick; Snead, John T.

    2009-01-01

    This article explores the geography of virtual questioning by using geographic information systems to study activity within the Florida Electronic Library "Ask a Librarian" collaborative chat service. Researchers mapped participating libraries throughout the state of Florida that served as virtual "entry portals" for users as…

  15. [Menstruation in the systemic context. New questions -- questionable connections].

    PubMed

    Lütje, W

    2005-10-01

    Experiencing and the significance of menstruation could possibly be a decisive factor in your physiology or pathologic physiology, in accordance with blood flow disturbance or endometriosis. Menstruation is a systemic, characteristic experience. Evolution, family, culture, community, media, health service and even the economy have an influence on the "period system". Damage and use, sense and the nonsensical of regular bleeding stand to the test. The cycle comes under increasing "pressure" and is no longer in "rhythm". Counter regulation, through regulation of the period seems to prevent the personal, community and health-wise restrictions. The price for this is unknown. Clearly, there is no longer a path between a natural, relaxed acceptance of and an artificial abolition of blood flow. The question of direction is posed in the menarche. This question remains unanswered even in our time.

  16. On a question of Gross

    NASA Astrophysics Data System (ADS)

    Banerjee, Abhijit

    2007-03-01

    Using the notion of weighted sharing of sets we prove two uniqueness theorems which improve the results proved by Fang and Qiu [H. Qiu, M. Fang, A unicity theorem for meromorphic functions, Bull. Malaysian Math. Sci. Soc. 25 (2002) 31-38], Lahiri and Banerjee [I. Lahiri, A. Banerjee, Uniqueness of meromorphic functions with deficient poles, Kyungpook Math. J. 44 (2004) 575-584] and Yi and Lin [H.X. Yi, W.C. Lin, Uniqueness theorems concerning a question of Gross, Proc. Japan Acad. Ser. A 80 (2004) 136-140] and thus provide an answer to the question of Gross [F. Gross, Factorization of meromorphic functions and some open problems, in: Proc. Conf. Univ. Kentucky, Lexington, KY, 1976, in: Lecture Notes in Math., vol. 599, Springer, Berlin, 1977, pp. 51-69], under a weaker hypothesis.

  17. Origin of Tektites.

    PubMed

    O'keefe, J A; Shute, B E

    1963-03-29

    A comet of the size recently postulated by H. C. Urey would leave a large crater. It is shown, from aerodynamic theory, from observations of distribution around terrestrial impact craters, and from experimental nuclear explosions, that the observed distribution of tektites cannot be the result of impact on the earth, whether cometary or meteoritic. It is further shown, from aerodynamic theory, from observation of a meteor shower, and from study of the breakup of artificial satellites, that the distribution of tektites can be accounted for as a result of fusion stripping of a satellite, as originally suggested by Suess.

  18. Unreviewed safety question determination application guide

    SciTech Connect

    Not Available

    1991-09-01

    The basic purpose of the Unreviewed Safety Question Determination (USQD) process is to ascertain if a change to a facility can be made without a prior safety review and approval by the original approving body. The USQD process judges whether the change could result in the facility being outside its authorization basis. If the change could result in the facility being outside its authorization basis, the change involves an Unreviewed Safety Question (USQ). The authorization basis consists of those aspects of the facility design basis relied upon by the original approving body to authorize operation. The authorization basis would typically include the facility Safety Analysis Report, Technical Safety Requirements (TSRs), Operational Safety Requirements (OSRs), Technical Specifications, DOE-issued Safety Evaluation Reports, Safety Analysis Report Update Program documents, Safety Studies, Safety Assessments, Risk Assessments, Facility Safety Evaluations, and any applicable commitments made to comply with Department of Energy (DOE) orders or policies. Steps in the USQD process include defining the changes being evaluated; evaluating the process by which the change is accomplished; then the potential effects of the change are compared to the authorization basis for the facility to determine if the change could result in the facility being outside is authorization basis. The USQD will provide input to the change control board for facilities placed under configuration management to aid their understanding of the extent of a proposed change and whether or not the change should be authorized. The USQD will also provide input to the categorization of reportable occurrences under DOE Order 5000.3A, Occurrence Reporting and Processing of Operations Information. This report provides an overview of the steps in the USQD process and detailed instructions and examples intended primarily for use by the personnel who perform, review, and approve the USQDs. 3 refs., 3 figs.

  19. Originator dynamics

    PubMed Central

    Manapat, Michael; Ohtsuki, Hisashi; Bürger, Reinhard; Nowak, Martin A.

    2009-01-01

    We study the origin of evolution. Evolution is based on replication, mutation, and selection. But how does evolution begin? When do chemical kinetics turn into evolutionary dynamics? We propose “prelife” and “prevolution” as the logical precursors of life and evolution. Prelife generates sequences of variable length. Prelife is a generative chemistry that proliferates information and produces diversity without replication. The resulting “prevolutionary dynamics” have mutation and selection. We propose an equation that allows us to investigate the origin of evolution. In one limit, this “originator equation” gives the classical selection equation. In the other limit, we obtain “prelife.” There is competition between life and prelife and there can be selection for or against replication. Simple prelife equations with uniform rate constants have the property that longer sequences are exponentially less frequent than shorter ones. But replication can reverse such an ordering. As the replication rate increases, some longer sequences can become more frequent than shorter ones. Thus, replication can lead to “reversals” in the equilibrium portraits. We study these reversals, which mark the transition from prelife to life in our model. If the replication potential exceeds a critical value, then life replicates into existence. PMID:18996397

  20. Classroom Questions. ERIC/AE Digest.

    ERIC Educational Resources Information Center

    Brualdi, Amy C.

    Questioning is one of the most popular modes of teaching, but it has the capacity to turn a child off to learning if done incorrectly. This digest provides teachers with information on the types of questions and questioning behaviors that can facilitate the learning process and on the types of questions that are ineffective. Good questions foster…

  1. Policy Determinations Regarding PSD Questions

    EPA Pesticide Factsheets

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  2. Let's Start at the Very Beginning: The Impact of Program Origins and Negotiated Community-University Partnerships on Canadian Radical Humanities Programs

    ERIC Educational Resources Information Center

    Groen, Janet; Hyland-Russell, Tara

    2012-01-01

    This article examines the community-university partnerships and the planning process of three Canadian Radical Humanities programs: programs that offer university entry-level humanities to adult learners on the margins of society. Examining these three iterations has revealed the significance of program origins, particularly the introduction of…

  3. Interim Exceptional Events Rule Frequently Asked Questions

    EPA Pesticide Factsheets

    Air agencies and other stakeholders have raised technical questions and issues related to implementation since the EPA promulgated the EER. This Question and Answer (Q&A) document is intended to respond to some of these frequently asked questions.

  4. Questions and answers based on revised 10 CFR Part 20

    SciTech Connect

    Borges, T.; Stafford, R.S.; Lu, P.Y.; Carter, D.

    1994-05-01

    NUREG/CR-6204 is a collection of questions and answers that were originally issued in seven sets and which pertain to revised 10 CFR Part 20. The questions came from both outside and within the NRC. The answers were compiled and provided by NRC staff within the offices of Nuclear Reactor Regulation, Nuclear Material Safety and Safeguards, Nuclear Regulatory Research, the Office of State Programs, and the five regional offices. Although all of the questions and answers have been reviewed by attorneys in the NRC Office of the General Counsel, they do not constitute official legal interpretations relevant to revised 10 CFR Part 20. The questions and answers do, however, reflect NRC staff decisions and technical options on aspects of the revised 10 CFR Part 20 regulatory requirements. This NUREG is being made available to encourage communication among the public, industry, and NRC staff concerning the major revisions of the NRC`s standards for protection against radiation.

  5. Information Extraction Supported Question Answering

    DTIC Science & Technology

    1999-10-15

    cymfony.com, wei@cymfony.com phone : (716) 565-9114 fax: (716) 565-0308 15 October, 1999 Abstract This paper discusses the use of our information...display a currently valid OMB control number . 1. REPORT DATE 19 OCT 1999 2. REPORT TYPE 3. DATES COVERED 00-10-1999 to 00-10-1999 4. TITLE AND...SUBTITLE Information Extraction Supported Question Answering 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT

  6. Origin of the moon - The collision hypothesis

    NASA Astrophysics Data System (ADS)

    Stevenson, D. J.

    By the impact or collision hypothesis, the author means any theory that seeks to derive the Moon-forming material from the outcome of one or more collisions between the Earth and other Sun-orbiting bodies. The impacting body or bodies must be large - larger than the Moon and perhaps even larger than Mars. This definition does not assume that the formation of the Moon was necessarily a singular event. Among proponents of the collision hypothesis, there are those who think that a single event overwhelmingly dominated and those who think that a few (or even many) impact events were needed. There are even versions of the collision hypothesis that are not very different from extreme versions of one of the alternative origin scenarios of capture, fission, and binary accretion! This review proceeds by advancing 10 propositions that the author believes embody the most important issues confronting the theory. These propositions may or may not be true, but they form a framework for asking the right questions.

  7. Biology Question Generation from a Semantic Network

    NASA Astrophysics Data System (ADS)

    Zhang, Lishan

    Science instructors need questions for use in exams, homework assignments, class discussions, reviews, and other instructional activities. Textbooks never have enough questions, so instructors must find them from other sources or generate their own questions. In order to supply instructors with biology questions, a semantic network approach was developed for generating open response biology questions. The generated questions were compared to professional authorized questions. To boost students' learning experience, adaptive selection was built on the generated questions. Bayesian Knowledge Tracing was used as embedded assessment of the student's current competence so that a suitable question could be selected based on the student's previous performance. A between-subjects experiment with 42 participants was performed, where half of the participants studied with adaptive selected questions and the rest studied with mal-adaptive order of questions. Both groups significantly improved their test scores, and the participants in adaptive group registered larger learning gains than participants in the control group. To explore the possibility of generating rich instructional feedback for machine-generated questions, a question-paragraph mapping task was identified. Given a set of questions and a list of paragraphs for a textbook, the goal of the task was to map the related paragraphs to each question. An algorithm was developed whose performance was comparable to human annotators. A multiple-choice question with high quality distractors (incorrect answers) can be pedagogically valuable as well as being much easier to grade than open-response questions. Thus, an algorithm was developed to generate good distractors for multiple-choice questions. The machine-generated multiple-choice questions were compared to human-generated questions in terms of three measures: question difficulty, question discrimination and distractor usefulness. By recruiting 200 participants from

  8. No question about exciting questions in cell biology.

    PubMed

    Pollard, Thomas D

    2013-12-01

    Although we have a good grasp of many important processes in cell biology, including knowledge of many molecules involved and how they interact with each other, we still do not understand most of the dynamical features that are the essence of living systems. Fortunately, we now have the ability to dissect biological systems in enough detail to understand their dynamics, including the use of mathematical models to account for past observations and predict future experiments. This deep level of mechanistic understanding should be our goal—not simply to satisfy our scientific curiosity, but also to understand the causes of disease well enough to predict risks, make early diagnoses, and treat effectively. Many big questions remain to be answered before we reach this goal of understanding cellular dynamics.

  9. The origin of lunar craters

    NASA Technical Reports Server (NTRS)

    Wegener, A.

    1975-01-01

    A review is presented of four hypotheses concerning the origin of lunar craters, taking into account the bubble hypothesis, the tide hypothesis, the volcanic hypothesis, and the impact hypothesis. A description is given of a series of experiments on impact craters and studies of a meteorite crater in Arizona are considered. It is concluded that the typical lunar craters can best be interpreted as impact craters.

  10. Investigations of Human Question Answering

    DTIC Science & Technology

    1990-02-01

    Aiello, & Miller, 1975; Graesser & Black, 1985; Graesser & Golding, 1988; Norman, 1973; Norman & Rumelhart, 1975; Piaget , 1952; Shanon, 1983; Trabasso...Rumelhart, D. E. (1975). Explorations in cognition. San Francisco: Freeman. Piaget , J. (1952). The origins of intelligence in children. New York...California 5825 Callaghan, Suite 225 Santa Barbara, CA 93106 San Antonio, TX 78228 Dr. Ralph Dusek Dr. Jean -Claude Falmagne V-P Human Factors Irvine

  11. Answering Key Fuel Cycle Questions

    SciTech Connect

    Piet, S.J.; Dixon, B.W.; Bennett, R.G.; Smith, J.D.; Hill, R.N.

    2004-10-03

    Given the range of fuel cycle goals and criteria, and the wide range of fuel cycle options, how can the set of options eventually be narrowed in a transparent and justifiable fashion? It is impractical to develop all options. We suggest an approach that starts by considering a range of goals for the Advanced Fuel Cycle Initiative (AFCI) and then posits seven questions, such as whether Cs and Sr isotopes should be separated from spent fuel and, if so, what should be done with them. For each question, we consider which of the goals may be relevant to eventually providing answers. The AFCI program has both ''outcome'' and ''process'' goals because it must address both waste already accumulating as well as completing the fuel cycle in connection with advanced nuclear power plant concepts. The outcome objectives are waste geologic repository capacity and cost, energy security and sustainability, proliferation resistance, fuel cycle economics, and safety. The process objectives are rea diness to proceed and adaptability and robustness in the face of uncertainties.

  12. Questioning Intuition through Reflective Engagement

    ERIC Educational Resources Information Center

    Schmidt, Christopher D.

    2014-01-01

    Current literature on ethics and moral development focuses on discussion concerning the impact of intuition on moral decision-making. Through the use of student journal reflections over the course of one semester, this study utilized a grounded theory approach in order to explore and understand participant levels of awareness and understanding of…

  13. Questions about Careers in Oceanography.

    ERIC Educational Resources Information Center

    Anderson, Aubrey L.

    Knowing the relationship of the ocean to man, the weather and climate, availability of resources from the ocean, use of the ocean in transporation, waste disposal, and defense, and developing an understanding of the impact on the oceans of human activity are all goals of oceanographers. The goal of this brochure is to provide concise informative…

  14. Answering Key Fuel Cycle Questions

    SciTech Connect

    Steven J. Piet; Brent W. Dixon; J. Stephen Herring; David E. Shropshire; Mary Lou Dunzik-Gougar

    2003-10-01

    The Advanced Fuel Cycle Initiative (AFCI) program has both “outcome” and “process” goals because it must address both waste already accumulating as well as completing the fuel cycle in connection with advanced nuclear power plant concepts. The outcome objectives are waste geological repository capacity and cost, energy security and sustainability, proliferation resistance, fuel cycle economics, and safety. The process objectives are readiness to proceed and adaptability and robustness in the face of uncertainties. A classic decision-making approach to such a multi-attribute problem would be to weight individual quantified criteria and calculate an overall figure of merit. This is inappropriate for several reasons. First, the goals are not independent. Second, the importance of different goals varies among stakeholders. Third, the importance of different goals is likely to vary with time, especially the “energy future.” Fourth, some key considerations are not easily or meaningfully quantifiable at present. Instead, at this point, we have developed 16 questions the AFCI program should answer and suggest an approach of determining for each whether relevant options improve meeting each of the program goals. We find that it is not always clear which option is best for a specific question and specific goal; this helps identify key issues for future work. In general, we suggest attempting to create as many win-win decisions (options that are attractive or neutral to most goals) as possible. Thus, to help clarify why the program is exploring the options it is, and to set the stage for future narrowing of options, we have developed 16 questions, as follows: · What are the AFCI program goals? · Which potential waste disposition approaches do we plan for? · What are the major separations, transmutation, and fuel options? · How do we address proliferation resistance? · Which potential energy futures do we plan for? · What potential external triggers do we

  15. [Nursing] Test Pool Questions. Area II.

    ERIC Educational Resources Information Center

    Watkins, Nettie; Patton, Bob

    This manual consists of area 2 test pool questions which are designed to assist instructors in selecting appropriate questions to help prepare practical nursing students for the Oklahoma state board exam. Multiple choice questions are utilized to facilitate testing of nursing 2 curriculum objectives. Each test contains questions covering each…

  16. Five Strategies for Questioning with Intention

    ERIC Educational Resources Information Center

    Costa, Arthur L.; Kallick, Bena

    2015-01-01

    Masterful teachers don't just ask a lot of questions; they ask questions in a purposeful way. In this article, Costa and Kallick describe five strategies that can help teachers become more purposeful in designing and posing questions. One strategy is to plan questions that elicit student thinking at various cognitive levels, from simple recall of…

  17. Questioning Technology in the Development of a Resilient Higher Education

    ERIC Educational Resources Information Center

    Hall, Richard; Winn, Joss

    2011-01-01

    This article considers the impact that peak oil and climate change may have on the future of higher education. In particular, it questions the role of technology in supporting the provision of a higher education which is resilient to a scenario both of energy depletion and the need to adapt to the effects of global warming. One emerging area of…

  18. Effect of Lecture Instruction on Student Performance on Qualitative Questions

    ERIC Educational Resources Information Center

    Heron, Paula R. L.

    2015-01-01

    The impact of lecture instruction on student conceptual understanding in physics has been the subject of research for several decades. Most studies have reported disappointingly small improvements in student performance on conceptual questions despite direct instruction on the relevant topics. These results have spurred a number of attempts to…

  19. Are Professors Professionals? A Fresh Look at This Question

    ERIC Educational Resources Information Center

    Newlyn, David

    2015-01-01

    Are university educators professionals? Whether or not university educators should be regarded as professionals is an important question that has an impact on a number of issues including job satisfaction, societal status and salary levels. This paper examines the need to classify this group as a profession and the consequences of that…

  20. Socratic Questioning in the Paideia Method to Encourage Dialogical Discussions

    ERIC Educational Resources Information Center

    Davies, Maree; Sinclair, Anne

    2014-01-01

    This study focused on the impact of using Socratic questioning, based on the Paideia Method, on the nature of middle-schools students' patterns of interaction and on the cognitive complexity of their discussions. The hypothesis is that an experimental group will increase in both interaction focus and complexity at T3, which is the face-to-face…

  1. Origins of magnetospheric plasma

    SciTech Connect

    Moore, T.E. )

    1991-01-01

    A review is given of recent (1987-1990) progress in understanding of the origins of plasmas in the earth's magnetosphere. In counterpoint to the early supposition that geomagnetic phenomena are produced by energetic plasmas of solar origin, 1987 saw the publication of a provocative argument that accelerated ionospheric plasma could supply all magnetospheric auroral and ring current particles. Significant new developments of existing data sets, as well as the establishment of entirely new data sets, have improved the ability to identify plasma source regions and to track plasma through the magnetospheric system of boundary layers and reservoirs. These developments suggest that the boundary between ionospheric and solar plasmas, once taken to lie at the plasmapause, actually lies much nearer to the magnetopause. Defining this boundary as the surface where solar wind and ionosphere contribute equally to the plasma, it is referred to herein as the 'geopause'. It is now well established that the infusion of ionospheric O(+) plays a major role in the storm-time distention of the magnetotail and inflation of the inner magnetosphere. After more than two decades of observation and debate, the question remains whether magnetosheric are protons of solar or terrestrial origin. 161 refs.

  2. Metabolic disorders and cardiovascular risk in treatment-naive HIV-infected patients of sub-saharan origin starting antiretrovirals: impact of westernized lifestyle.

    PubMed

    Eholié, Serge Paul; Lacombe, Karine; Krain, Alysa; Diallo, Zelica; Ouiminga, Mariama; Campa, Pauline; Bouchaud, Olivier; Bissagnene, Emmanuel; Girard, Pierre-Marie

    2015-04-01

    In a cohort of HIV-infected patients of sub-Saharan origin we describe the incidence of metabolic syndrome, insulin resistance, and lipodystrophy after 3 years of combined antiretroviral therapy, and model the 10-year risk of cardiovascular diseases, while taking into account environmental factors. This is a multinational, prospective cohort study conducted in HIV outpatient clinics from four tertiary care centers set in France and Côte d'Ivoire. The participants were HIV-infected, treatment-naive patients eligible to start antiretroviral treatment and were of sub-Saharan African origin. The main outcome measures were the incidence of metabolic syndrome, insulin resistance, and lipodystrophy, and the assessment of the 10-year risk of cardiovascular diseases using Framingham risk prediction, D.A.D. Cardiovascular Disease Risk, and WHO/ISH prediction charts. Of 245 patients followed for up to 3 years, the incidence of metabolic syndrome, insulin resistance, and lipodystrophy was 5.5, 8.5, and 6.8 per 100 person-years of follow-up (cumulative incidence: 14.4%, 19.2%, and 18.1%, respectively). Living in France as well as female gender and being overweight were risk factors for metabolic disorders as whole and only first generation protease inhibitors were marginally associated with metabolic syndrome. Cardiovascular risk as modeled through the three equations was high in all patients with the synergistic and deleterious effect of living in France compared to Côte d'Ivoire. This cohort study shows how the synergy between HIV, antiretroviral (ARV) exposure, and westernization of life style in a cohort of HIV-infected patients of sub-Saharan origin leads to a progressive increase in the risk of lipodystrophy, as well as metabolic syndrome and insulin resistance, all associated with increased cardiovascular risk.

  3. Probiotic Potential of a Lactobacillus Bacterium of Canine Faecal-Origin and Its Impact on Select Gut Health Indices and Immune Response of Dogs.

    PubMed

    Kumar, Sachin; Pattanaik, Ashok Kumar; Sharma, Shalini; Jadhav, Sunil Eknath; Dutta, Narayan; Kumar, Avneesh

    2017-02-10

    The objective of the present study was to develop a probiotic of canine-origin for its potential application in pet nutrition. Accordingly, 32 lactic acid bacteria (LAB) strains were isolated from faeces of dogs, out of which 9 strains were short-listed for further in vitro testing based on the aggregation time and cell surface hydrophobicity. The results of acid-, bile- and phenol-tolerance tests indicated that out of the nine, isolate cPRO23 was having better resistance to these adverse conditions likely to be encountered in the gastrointestinal tract. The isolate also showed optimal enzymatic activities for amylase, lipase and protease. Further assessments also indicated its superiority in terms of co-aggregation and antagonistic activity against pathogenic strains of Salmonella typhimurium and Salmonella enteritidis. Subsequently, the isolate was identified through 16S rRNA sequencing and sequence homology, and designated as Lactobacillus johnsonii CPN23. The candidate probiotic was then evaluated in vivo using 15 adult Labrador dogs, divided into 3 groups, viz. CON (with no probiotics), dPRO (with Lactobacillus acidophilus NCDC 15 as a conventional dairy-origin probiotic) and cPRO (with L. johnsonii CPN23 as a canine-origin probiotic). Results of the 9-week study indicated that supplementation of cPRO improved (P < 0.05) the faecal concentration of acetate and butyrate with a concomitant reduction (P < 0.05) in faecal ammonia. The cell-mediated immune response, assessed as delayed-type hypersensitivity reaction to phytohaemagglutinin-P, was better (P < 0.05) in dogs fed cPRO as compared to the CON dogs. There were, however, no variations evident in the antibody response to sheep-erythrocytes among the three groups. It is concluded that the canine-origin L. johnsonii CPN23, in addition to possessing all the in vitro functional attributes of a candidate probiotic, also has the potential to be used as a probiotic in pet nutrition programs.

  4. Wolf presence in the ranch of origin: impacts on temperament and physiological responses of beef cattle following a simulated wolf encounter.

    PubMed

    Cooke, R F; Bohnert, D W; Reis, M M; Cappellozza, B I

    2013-12-01

    This experiment evaluated temperament, vaginal temperature, and plasma cortisol in beef cows from wolf-naïve and wolf-experienced origins that were subjected to a simulated wolf encounter. Multiparous, pregnant, nonlactating Angus-crossbreed cows from the Eastern Oregon Agricultural Research Center located near Burns, OR (CON; n = 50), and from a commercial operation near Council, ID (WLF; n = 50), were used. To date, grey wolves are not present around Burns, OR, and thus CON were naïve to wolves. Conversely, wolves are present around Council, ID, and WLF cows were selected from a herd that had experienced multiple confirmed wolf-predation episodes from 2008 to 2012. Following a 50-d commingling and adaptation period, CON and WLF cows were ranked by temperament, BW, and BCS and allocated to 5 groups (d 0; 10 CON and 10 WLF cows/group). Groups were individually subjected to the experimental procedures on d 2 (n = 3) and d 3 (n = 2). Before the simulated wolf encounter, cow temperament was assessed and blood samples and vaginal temperatures (using intravaginal data loggers) were collected (presimulation assessments). Cows were then sorted by origin, moved to 2 adjacent drylot pens (10 WLF and 10 CON cows/pen), and subjected to a simulated wolf encounter event for 20 min, which consisted of 1) cotton plugs saturated with wolf urine attached to the drylot fence, 2) continuous reproduction of wolf howls, and 3) 3 leashed dogs that were walked along the fence perimeter. Thereafter, WLF and CON cows were commingled and returned to the handling facility for postsimulation assessments, which were conducted immediately after exposure to wolf-urine-saturated cotton plugs, wolf howl reproduction, and 20-s exposure to the 3 dogs while being restrained in a squeeze chute. Chute score, temperament score, and plasma cortisol concentration increased (P ≤ 0.01) from pre- to postsimulation assessment in WLF but did not change in CON cows (P ≥ 0.19). Exit velocity decreased (P

  5. An abiotic origin for hydrocarbons in the Allan Hills 84001 martian meteorite through cooling of magmatic and impact-generated gases.

    PubMed

    Zolotov MYu; Shock, E L

    2000-05-01

    Thermodynamic calculations of metastable equilibria were used to evaluate the potential for abiotic synthesis of aliphatic and polycyclic aromatic hydrocarbons (PAHs) in the martian meteorite Allan Hills (ALH) 84001. The calculations show that PAHs and normal alkanes could form metastably from CO, CO2, and H2 below approximately 250-300 degrees C during rapid cooling of trapped magmatic or impact-generated gases. Depending on temperature, bulk composition, and oxidation-reduction conditions, PAHs and normal alkanes can form simultaneously or separately. Moreover, PAHs can form at lower H/C ratios, higher CO/CO2 ratios, and higher temperatures than normal alkanes. Dry conditions with H/C ratios less than approximately 0.01-0.001 together with high CO/CO2 ratios also favor the formation of unalkylated PAHs. The observed abundance of PAHs, their low alkylation, and a variable but high aromatic to aliphatic ratio in ALH 84001 all correspond to low H/C and high CO/CO2 ratios in magmatic and impact gases and can be used to deduce spatial variations of these ratios. Some hydrocarbons could have been formed from trapped magmatic gases, especially if the cooling was fast enough to prevent reequilibration. We propose that subsequent impact heating(s) in ALH 84001 could have led to dissociation of ferrous carbonates to yield fine-grain magnetite, formation of a CO-rich local gas phase, reduction of water vapor to H2, reequilibration of the trapped magmatic gases, aromatization of hydrocarbons formed previously, and overprinting of the synthesis from magmatic gases, if any. Rapid cooling and high-temperature quenching of CO-, H2-rich impact gases could have led to magnetite-catalyzed hydrocarbon synthesis.

  6. An abiotic origin for hydrocarbons in the Allan Hills 84001 martian meteorite through cooling of magmatic and impact-generated gases

    NASA Technical Reports Server (NTRS)

    Shock, E. L.

    2000-01-01

    Thermodynamic calculations of metastable equilibria were used to evaluate the potential for abiotic synthesis of aliphatic and polycyclic aromatic hydrocarbons (PAHs) in the martian meteorite Allan Hills (ALH) 84001. The calculations show that PAHs and normal alkanes could form metastably from CO, CO2, and H2 below approximately 250-300 degrees C during rapid cooling of trapped magmatic or impact-generated gases. Depending on temperature, bulk composition, and oxidation-reduction conditions, PAHs and normal alkanes can form simultaneously or separately. Moreover, PAHs can form at lower H/C ratios, higher CO/CO2 ratios, and higher temperatures than normal alkanes. Dry conditions with H/C ratios less than approximately 0.01-0.001 together with high CO/CO2 ratios also favor the formation of unalkylated PAHs. The observed abundance of PAHs, their low alkylation, and a variable but high aromatic to aliphatic ratio in ALH 84001 all correspond to low H/C and high CO/CO2 ratios in magmatic and impact gases and can be used to deduce spatial variations of these ratios. Some hydrocarbons could have been formed from trapped magmatic gases, especially if the cooling was fast enough to prevent reequilibration. We propose that subsequent impact heating(s) in ALH 84001 could have led to dissociation of ferrous carbonates to yield fine-grain magnetite, formation of a CO-rich local gas phase, reduction of water vapor to H2, reequilibration of the trapped magmatic gases, aromatization of hydrocarbons formed previously, and overprinting of the synthesis from magmatic gases, if any. Rapid cooling and high-temperature quenching of CO-, H2-rich impact gases could have led to magnetite-catalyzed hydrocarbon synthesis.

  7. Isotopic tracing of the impact of mobility on infectious disease: The origin of people with treponematosis buried in hull, England, in the late medieval period.

    PubMed

    Roberts, C A; Millard, A R; Nowell, G M; Gröcke, D R; Macpherson, C G; Pearson, D G; Evans, D H

    2013-02-01

    Treponematosis has been one of the most studied and debated infectious diseases in paleopathology, particularly from the standpoint of its origin, evolution, and transmission. This study links evidence for treponematosis in skeletons from the 14th-16th century AD cemetery of the Augustinian friary of Hull Magistrates Court, England, with data from stable isotope analysis to test the hypothesis that the people with treponemal disease buried at this site were not locally born and raised. The objective is to explore the potential of using stable isotope data to track the place of origin and extent of mobility of individuals with an infectious disease. Dental enamel samples of 12 skeletons were selected for strontium ((87) Sr/(86) Sr ratio) and oxygen (δ(18) O) stable isotope analysis based on the presence (six - diseased) or absence (six - controls) of bone changes associated with treponemal disease. The oxygen isotope ratios of all but three individuals (1047, 1121, 823) overlapped at two standard deviations with the inferred local precipitation range, and only one individual (1216) had a strontium isotope ratio outside the regional range. Two of the four had probable/possible treponemal bone changes. Those with treponemal bone changes were not demonstrably more likely to be migrants than those without such lesions. However, because of extensive documentary evidence for trade with the Baltic Sea area, and for merchants from towns such as Stralsund, Danzig and Elbing being in Hull, it is very plausible that the four migrants came from the Baltic area or even southern Sweden.

  8. Impact of origin and biological source on chemical composition, anticholinesterase and antioxidant properties of some St. John's wort species (Hypericum spp., Hypericaceae) from the Central Balkans.

    PubMed

    Božin, Biljana; Kladar, Nebojša; Grujić, Nevena; Anačkov, Goran; Samojlik, Isidora; Gavarić, Neda; Conić, Branislava Srđenović

    2013-09-25

    The study shows the influence of the origin of plant material and biological source on the in vitro antioxidant (neutralization of DPPH and OH radical, nitric oxide, and inhibition of lipid peroxidation) and anticholinesterase activity of chemically characterized and quantified ethanol extracts of ten St. John's wort samples. The investigated samples were: five Hypericum perforatum species representatives collected at different localities, one commercial sample of Hyperici herba purchased at a local market and four Hypericum species autochtonous to the Balkan Peninsula (H. maculatum subsp. immaculatum, H. olympicum, H. richeri subsp. grisebachii and H. barbatum). All the examined extracts exhibited notable antioxidant potential, but in most of the cases indigenous Hypericum species expressed stronger effects compared to the original source of the drug, H. perforatum. The changes in the content of phenolic compounds, especially flavonoids, hyperforin and hypericin, related to the source of the drug affected the investigated activities. Since all of the investigated species have shown prominent inhibition of acetylcholinesterase in vitro activity, they could be further investigated as potential substances in preventing of Alzheimer's disease.

  9. Impact of dose-dense immunochemotherapy on prognosis of germinal center and non germinal center origin of diffuse large B cell lymphoma.

    PubMed

    Rigacci, L; Puccini, B; Iovino, L; Martelli, M; Finolezzi, E; DI Lollo, S; Doria, M; Bosi, A

    2011-08-01

    Diffuse large B cell lymphoma (DLBCL) is the most common type of non-Hodgkin's lymphoma. Gene-expression profiling in DLCBL has brought insight into the biological heterogeneity of the disease. Two major subgroups have been identified: germinal center B (GCB) cell and non-germinal center (non-GCB). The aim of this study was to define retrospectively by immunohistochemistry the bcell origin of 69 patients treated with R-CHOP14 and to evaluate if dose-dense therapy could improve their clinical outcome. According to immunohistochemistry analysis 28 patients were derived from germinal center and 41 from non-germinal center. After a median period of observation of 46 months (range 3-101 months) the overall survival (OS) was 75% and progression-free survival (PFS) was 53% and no differences were observed according to cell origin. In conclusion, we can point out that intensification could enhance the efficacy of the R-CHOP regimen and improve overall survival in patients with non germinal lymphoma.

  10. Different impact of heat-inactivated and viable lactic acid bacteria of aquatic origin on turbot (Scophthalmus maximus L.) head-kidney leucocytes.

    PubMed

    Muñoz-Atienza, Estefanía; Araújo, Carlos; Lluch, Nuria; Hernández, Pablo E; Herranz, Carmen; Cintas, Luis M; Magadán, Susana

    2015-05-01

    In aquaculture, several criteria should be considered to select an appropriate probiotic, including the aquatic origin and safety of the strain and its ability to modulate the host immune response. The properties and effects of probiotics are strain-specific and some factors such as viability, dose and duration of diet supplementation may regulate their immunomodulatory activities. In this study, we assessed the in vitro effect of eight heat-inactivated and viable lactic acid bacteria (LAB) of aquatic origin belonging to the genera Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Weissella on the viability and innate immune response of turbot (Scophthalmus maximus L.) leucocytes. Head-kidney leucocytes were incubated with viable and heat-inactivated LAB at different concentrations. After incubation, the viability of leucocytes was evaluated using colorimetric assays (MTT and LDH) and flow cytometry (annexin V/propidium iodide). Heat-inactivated LAB showed no cytotoxic effect while viable LAB exerted variable influence on apoptosis of turbot phagocytes and lymphocytes. Leucocyte respiratory burst activity and phagocytosis were also differentially activated, as viable LAB stimulated leucocytes more efficiently than the heat-inactivated LAB. Our results suggest diverse strain-specific mechanisms of interaction between the evaluated LAB and turbot leucocytes. Furthermore, our work sets up in vitro systems to evaluate the effect of LAB as potential probiotics, which will be useful to develop efficient screening.

  11. Evaluation of four maternal smoking questions.

    PubMed Central

    Kharrazi, M; Epstein, D; Hopkins, B; Kreutzer, R; Doebbert, G; Hiatt, R; Swan, S; Eskenazi, B; Pirkle, J L; Bernert, J T

    1999-01-01

    OBJECTIVE: The authors evaluated four questions about maternal smoking during pregnancy for use on birth certificates. METHODS: Question 1 (yes/no format) and Question 2 (trimester-specific design) were tested among 1171 women who delivered at two Kaiser Permanente medical centers in northern California. Responses to Questions 1 and 2 were compared with smoking information provided by participants in telephone interviews conducted during pregnancy. Question 3 (multiple choice format) and Question 4 (month- and grouped month-specific design) were tested among 900 women who enrolled in a statewide prenatal screening program and who delivered in 20 hospitals in four Central Valley counties. Responses to Questions 3 and 4 were compared with mid-pregnancy serum cotinine levels. The authors evaluated the four questions in terms of conciseness, response rate, data accuracy, and type of data requested. RESULTS: Questions 1 and 2 were the most concise. Response rates could not be calculated for Questions 1 and 2. Response rates were 86.0% for Question 3 and 74.2% for Question 4. Sensitivity was 47.3% for Question 1, 62.1% for Question 2, 83.8% for Question 3, and 86.7% for Question 4. The types of data requested by Questions 2 and 4 seem to best satisfy the needs of the broad audience of birth certificate users. CONCLUSIONS: No single question was clearly superior. The authors propose a combination of Questions 2 and 4, which asks about average number of cigarettes smoked per day in the three months before pregnancy and in each trimester of pregnancy. PMID:9925173

  12. Lac Télé structure, Republic of Congo: Geological setting of a cryptozoological and biodiversity hotspot, and evidence against an impact origin

    NASA Astrophysics Data System (ADS)

    Master, Sharad

    2010-11-01

    Lac Télé is a large lake, ˜5.6 km in diameter, with an ovoid shape, situated at 17°10'E, 1°20'N, in the great tropical rain forest region of the Republic of Congo. This lake has attracted widespread attention, mainly because of the legends among the local people that it harbours a strange animal known as the Mokele-Mbembe, but also because it is situated in a region that is a hotbed of biodiversity and conservation efforts with respect to various endangered mammalian species, including gorillas and chimpanzees. Because of its appearance, Lac Télé has been regarded as a possible meteorite impact structure. Various expeditions, studying cryptozoology, conservation ecology, biodiversity, and the impact hypothesis, have visited Lac Télé in the past several decades. The Lac Télé structure is located in the NW part of the intracratonic Congo Basin, in a region dominated by Holocene alluvium, dense tropical rain forest, and swamps which form part of the basin of the Likouala aux Herbes, a multi-branched meandering river flowing over very low gradients into the Sangha river, a major tributary of the Congo river. Previous bathymetric studies have shown that the average depth of Lac Télé is only 4 m, including organic-rich silty sediments. The structure is that of a flat-bottomed dish. Modelling of the Lac Télé as an impact structure indicates a number of features which ought to be present. The absence of any of these features, coupled with the irregular ovoid shape, the palynological record, and the location of the structure at the intersection of major regional lineaments, is regarded as evidence against the impact hypothesis. Lac Télé as an isolated lake ecosystem is not unique in the Congo Basin, and there are several other similar small shallow isolated lakes surrounded by rain forest and marshes, some of which formed by damming of drainage systems by neotectonic faults. It is suggested that the formation of Lac Télé may be related to its location

  13. Chemical Impact of Solar Energetic Particle Event From The Young Sun: Implications for the Origin of Prebiotic Chemistry and the Fain Young Sun Paradox

    NASA Astrophysics Data System (ADS)

    Airapetian, V.; Gronoff, G.; Hébrard, E.; Danchi, W.

    2015-12-01

    Understanding how the simple molecules present on the early Earth and possibly Mars may have set a path for complex biological molecules, the building blocks of life, represents one of greatest unsolved questions. Here we present a new model of the rise of the abiotic nitrogen fixation and associated pre-biotic chemistry in the early Earth and Mars atmosphere mediated by solar eruptive events. Our physical models of interaction of magnetic clouds ejected from the young Sun with magnetospheres of the early Earth show significant perturbations of geomagnetic fields that produce extended polar caps. These polar caps provide pathways for energetic particles associated with magnetic clouds to penetrate into the nitrogen-rich weakly reducing atmosphere and initiate the reactive chemistry by breaking molecular nitrogen, carbon dioxide, methane and producing hydrogen cyanide, the essential compound for life. The model also shows that contrary to the current models of warming of early Earth and Mars, major atmospheric constituents, CO2 and CH4 will be destroyed due to collisional dissociation with energetic particles. Instead, efficient formation of the potent greenhouse gas, nitrous oxide, as a by-product of these processes is expected. This mechanism can consistently explain the Faint Young Sun's paradox for the early atmospheres of Earth and Mars. Our new model provides insight into how life may have initiated on Earth and Mars and how to search for the spectral signatures on planets "pregnant" with the potential for life.

  14. Does Question Structure Affect Exam Performance in the Geosciences?

    NASA Astrophysics Data System (ADS)

    Day, E. A.; D'Arcy, M. K.; Craig, L.; Streule, M. J.; Passmore, E.; Irving, J. C. E.

    2015-12-01

    The jump to university level exams can be challenging for some students, often resulting in poor marks, which may be detrimental to their confidence and ultimately affect their overall degree class. Previous studies have found that question structure can have a strong impact on the performance of students in college level exams (see Gibson et al., 2015, for a discussion of its impact on physics undergraduates). Here, we investigate the effect of question structure on the exam results of geology and geophysics undergraduate students. Specifically, we analyse the performance of students in questions that have a 'scaffolded' framework and compare them to their performance in open-ended questions and coursework. We also investigate if observed differences in exam performance are correlated with the educational background and gender of students, amongst other factors. It is important for all students to be able to access their degree courses, no matter what their backgrounds may be. Broadening participation in the geosciences relies on removing systematic barriers to achievement. Therefore we recommend that exams are either structured with scaffolding in questions at lower levels, or students are explicitly prepared for this transition. We also recommend that longitudinal studies of exam performance are conducted within individual departments, and this work outlines one approach to analysing performance data.

  15. Conducting systematic reviews of intervention questions I: Writing the review protocol, formulating the question and searching the literature.

    PubMed

    O'Connor, A M; Anderson, K M; Goodell, C K; Sargeant, J M

    2014-06-01

    This article is the fourth of six articles addressing systematic reviews in animal agriculture and veterinary medicine. Previous articles in the series have introduced systematic reviews, discussed study designs and hierarchies of evidence, and provided details on conducting randomized controlled trials, a common design for use in systematic reviews. This article describes development of a review protocol and the first two steps in a systematic review: formulating a review question, and searching the literature for relevant research. The emphasis is on systematic reviews of questions related to interventions. The review protocol is developed prior to conducting the review and specifies the plan for the conduct of the review, identifies the roles and responsibilities of the review team and provides structured definitions related to the review question. For intervention questions, the review question should be defined by the PICO components: population, intervention, comparison and outcome(s). The literature search is designed to identify all potentially relevant original research that may address the question. Search terms related to some or all of the PICO components are entered into literature databases, and searches for unpublished literature also are conducted. All steps of the literature search are documented to provide transparent reporting of the process.

  16. Basaltic glass formed from hydrovolcanism and impact processes: Characterization and clues for detection of mode of origin from VNIR through MWIR reflectance and emission spectroscopy

    NASA Astrophysics Data System (ADS)

    Farrand, W. H.; Wright, S. P.; Rogers, A. D.; Glotch, T. D.

    2016-09-01

    The CheMin X-ray diffraction instrument on-board the Curiosity rover in Gale crater has measured a consistent X-ray amorphous component in drill core samples examined to-date, clearly demonstrating that X-ray amorphous materials are a significant fraction of the martian surface layer. Glasses are potential components of this amorphous material and in this study, basaltic tephras from several hydro- and glaciovolcanic centers, as well as impact melts from India's Lonar Crater, were examined using thin section petrography, visible and near-infrared reflectance and mid-wave infrared emission spectroscopy as well as measuring major and minor element chemistry of representative samples using X-ray fluorescence (XRF) spectroscopy. The objectives of this study have been to look for distinguishing characteristics between volcanic and impact glasses and to determine features that indicate whether the glasses are fresh or altered using methods available on current and planned Mars rovers. Spectral features in the visible and near-infrared (VNIR) that can be used as indicators of alteration include the development of hydration features at 1.9 and ∼3 μm and a feature attributed to ferric oxide development at 0.48 μm. In the mid-wave infrared, it was observed that glass-rich tephra field samples did not display a broad, disordered glass feature near 9-10 μm (as is observed in pristine basaltic glasses) but rather a doublet with centers near 9.5 and 11 μm attributed in earlier work to incipient devitrification into SiO4 chain and sheet structures respectively. A tentative observation was made that the Si-O bending feature, observed in all the sample spectra near 22 μm was broader in the hydro- and glaciovolcanic glass samples than in the impact glass samples. Hydro- and glaciovolcanic glass-rich tephra samples were used as library spectra in linear deconvolution analyses of Mars Global Surveyor Thermal Emission Spectrometer (MGS TES) surface spectral types. These

  17. Muddy and dolomitic rip-up clasts in Triassic fluvial sandstones: Origin and impact on potential reservoir properties (Argana Basin, Morocco)

    NASA Astrophysics Data System (ADS)

    Henares, Saturnina; Arribas, Jose; Cultrone, Giuseppe; Viseras, Cesar

    2016-06-01

    The significance of rip-up clasts as sandstone framework grains is frequently neglected in the literature being considered as accessory components in bulk sandstone composition. However, this study highlights the great value of muddy and dolomitic rip-up clast occurrence as: (a) information source about low preservation potential from floodplain deposits and (b) key element controlling host sandstone diagenetic evolution and thus ultimate reservoir quality. High-resolution petrographic analysis on Triassic fluvial sandstones from Argana Basin (T6 and T7/T8 units) highlights the significance of different types of rip-up clasts as intrabasinal framework components of continental sediments from arid climates. On the basis of their composition and ductility, three main types are distinguished: (a) muddy rip-up clasts, (b) dolomitic muddy rip-up clasts and (c) dolomite crystalline rip-up clasts. Spatial distribution of different types is strongly facies-related according to grain size. Origin of rip-up clasts is related to erosion of coeval phreatic dolocretes, in different development stages, and associated muddy floodplain sediments. Cloudy cores with abundant inclusions and clear outer rims of dolomite crystals suggest a first replacive and a subsequent displacive growth, respectively. Dolomite crystals are almost stoichiometric. This composition is very similar to that of early sandstone dolomite cement, supporting phreatic dolocretes as dolomite origin in both situations. Sandstone diagenesis is dominated by mechanical compaction and dolomite cementation. A direct correlation exists between: (1) muddy rip-up clast abundance and early reduction of primary porosity by compaction with irreversible loss of intergranular volume (IGV); and (2) occurrence of dolomitic rip-up clasts and dolomite cement nucleation in host sandstone, occluding adjacent pores but preserving IGV. Both processes affect reservoir quality by generation of vertical and 3D fluid flow baffles and

  18. [Multiple sclerosis: etiology, epidemiology, some questions of pathogenicity].

    PubMed

    Chuprina, H M

    2012-01-01

    In the article the questions of ways of development of the dissipated sclerosis, as nosologies, are affected from the group of autoimmune diseases. Examined etiology, epidedemiologiya, separate links of pathogeny of the dissipated sclerosis. The analysis of multifaktors of his origin is conducted, with the detailed study of internal and external factors, marked on the important role of inherited predisposition, infectious and klimato-geograficheskogo factors in genesis of the dissipated sclerosis.

  19. Core questions in domestication research

    PubMed Central

    Zeder, Melinda A.

    2015-01-01

    The domestication of plants and animals is a key transition in human history, and its profound and continuing impacts are the focus of a broad range of transdisciplinary research spanning the physical, biological, and social sciences. Three central aspects of domestication that cut across and unify this diverse array of research perspectives are addressed here. Domestication is defined as a distinctive coevolutionary, mutualistic relationship between domesticator and domesticate and distinguished from related but ultimately different processes of resource management and agriculture. The relative utility of genetic, phenotypic, plastic, and contextual markers of evolving domesticatory relationships is discussed. Causal factors are considered, and two leading explanatory frameworks for initial domestication of plants and animals, one grounded in optimal foraging theory and the other in niche-construction theory, are compared. PMID:25713127

  20. Partitioning of Cr, V, and Mn between mantles and cores of differentiated planetesimals - Implications for giant impact hypothesis of lunar origin

    SciTech Connect

    Ringwood, A.E.; Kato, T.; Hibberson, W.; Ware, N. )

    1991-01-01

    The partition coefficients of Cr, V, and Mn between metallic Fe and the mineral phases present in the mantle of a giant planetesimal have been determined in the 1500-2000 C range at 3-25 GPa, in order to ascertain whether the formation of an Fe core within a differentiated giant planetesimal could have caused depletions of Cr, V, and Mn in the Mars-sized planetesimal hypothesized as the basis for lunar formation after impact with the earth. The results obtained indicate that the formation of such an Fe core would have led to no such depletion; Cr, V, and Mn are depleted relative to Mg in the earth mantle to a degree comparable to the lunar depletion factor, suggesting that the protolunar material was primarily derived from the earth's mantle. 36 refs.

  1. The Cantarell Breccia System, Southern Gulf Of Mexico: Structural Evolution And Support For An Origin Relarted To The Chixculub Meteorite Impact

    NASA Astrophysics Data System (ADS)

    Ricoy, V.

    2003-04-01

    The Upper Cretaceous within the Campeche Basin, southern Gulf of Mexico hosts a world class petroleum system. Cantarell is the most important reservoir that consists of a complex brecciated carbonate reservoir deposited at or around the Cretaceous-Tertiary boundary. Previous sedimentological studies suggests that the Upper Cretaceous Carbonate breccias found in the Cantarell oilfield system and through the Bay of Campeche, were the result of a catastrophic shelf collapse event triggered by the Chixculub meteorite impact. This work presents new evidence from structural and stratigraphic interpretation of 3D seismic and 2D lines which gives light to features that support the platform collapse model. The reservoir consists of thick (up to 300 m), heterogeneous, monomyctic and polymictic breccias developed at the K-T boundary, and widely distributed throughout the Campeche Basin. The timing, internal architecture, widespread deposition and distance to the platform margin source (over 30 kms) of the breccia unit, combined with a contorted irregular seismic reflector near the base of the Cretaceous carbonate platform, suggests that the geological processes accountable for the emplacement of the breccias relates to the massive catastrophic collapse of the Cretaceous platform as a result of the Chixculub meteorite impact. Structural interpretation of the 3D seismic data, together with well stratigraphic markers unraveled a complex Oligocene-Miocene structural deformation history of the Cantarell field, which resulted in several discrete reservoir blocks partitioned by a complex array of thrusts, normal and reverse faults. It is proposed that the structural deformation of the area controlled to a large extent the distribution of the reservoir properties found in the Cantarell area. This idea is tested using the structural model matched against the well log porosity data.

  2. Modeling sea salt and sulfate aerosol over the global oceans to understand the origins of marine cloud condensation nuclei and the impact of pollution on them

    NASA Astrophysics Data System (ADS)

    Fan, Tianyi

    Over the oceans, anthropogenic aerosols compete with natural aerosols from sea spray and oceanic phytoplankton-derived sulfate to create cloud condensation nuclei (CCN). To understand the impact of pollution on the marine CCN, we need knowledge of both natural and anthropogenic aerosols. In this research, we model sea salt and sulfate aerosol in a coupled climate and sectional microphysical model, CAM/CARMA. We develop a sea salt source function, CMS, based upon several earlier source functions (Clarke, Monahan, and Smith). The CMS source function is capable of reproducing observed sea salt mass, optical depth and number concentration as well as the size distribution better than other source function choices we tried. However, as we note, it is also important to properly set the removal rate of the particles to reproduce the observed abundances. The simulated non-sea-salt sulfate mass agrees well with the observations. Direct emission of sulfate from sea spray is the largest source of marine sulfate aerosol and depends on the sea salt emission. Non-sea-salt sulfate from gas- and aqueous-phase conversion, together with sea salt, contributes to the marine CCN over the mid-latitude Northern Hemisphere, while sea salt dominates the CCN over the Southern Ocean. Human impact on marine CCN extends to 45 oS. Anthropogenic sulfur emissions are responsible for about 35% of the surface layer CCN over the global oceans. With doubling the year 2000 anthropogenic sulfur emissions. Surface layer CCN increases by about 22% over the global oceans if sulfur emissions are doubled from. With no or double anthropogenic emissions, the changes in the surface layer CCN number over the Southern Hemisphere oceans are usually less than 10%.

  3. Regional Screening Levels Frequent Questions (May 2016)

    EPA Pesticide Factsheets

    Regional Screening Level RSL frequently asked question FAQ page provides risk assessors answers to common questions about the preliminary remediation goal PRG risk based concentration RBC and risk calculator for the assessment of human Health.

  4. Questions for Your Doctor: Your First Visit

    MedlinePlus

    The Testicular Cancer Resource Center Questions for your Doctor: Your First Visit This list of questions is intended to help ... cancer, be happy, but also be aware that testicular cancer is misdiagnosed as epididymitis or something similar almost ...

  5. What Questions Should I Ask My Doctor?

    MedlinePlus

    ... Trials Database Supporting Research Raising Awareness Our Blog Patient Education Pancreas News Basics of Pancreatic Cancer FAQs The ... Detection- Goggins Lab Sol Goldman Center Discussion Board Patient Education / Basics of Pancreatic Cancer Questions What questions should ...

  6. Questions and Answers for Architectural Coatings Rule

    EPA Pesticide Factsheets

    The EPA compiled this question and answer document from inquiries received after the publication of the 1999 final architectural coatings rule and from questions raised at meetings with industry associations.

  7. What Questions Do They Ask? Ausubel Rephrased.

    ERIC Educational Resources Information Center

    Spargo, Peter E.; Enderstein, L. Gus

    1997-01-01

    Investigates what questions elementary students would ask when presented with various situations relating to the natural environment. Findings reveal the extraordinary range of questions that elementary students have concerning the solar system and space. (JRH)

  8. Provocative Questions in Cancer: NCI Seminar

    Cancer.gov

    science writers' seminar to discuss various aspects of one of NCI’s signature efforts -- the Provocative Questions project. Discussion will focus on the scientific research that surrounds some of these questions.

  9. Two-Year-Old Children Differentiate Test Questions from Genuine Questions

    ERIC Educational Resources Information Center

    Grosse, Gerlind; Tomasello, Michael

    2012-01-01

    Children are frequently confronted with so-called "test questions". While genuine questions are requests for missing information, test questions ask for information obviously already known to the questioner. In this study we explored whether two-year-old children respond differentially to one and the same question used as either a genuine question…

  10. Better Questions and Answers Equal Success.

    ERIC Educational Resources Information Center

    Swicegood, Philip R.; Parsons, James L.

    1989-01-01

    Students with learning disabilities and behavior problems need instruction designed to increase active thinking and questioning skills. Described methods for teaching these skills include T. Raphael's question-answer relationships, A. Hahn's questioning strategy, reciprocal teaching, and the "ReQuest" procedure. Practice activities for…

  11. Questions and Answers About Nuclear Power Plants.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC.

    This pamphlet is designed to answer many of the questions that have arisen about nuclear power plants and the environment. It is organized into a question and answer format, with the questions taken from those most often asked by the public. Topics include regulation of nuclear power sources, potential dangers to people's health, whether nuclear…

  12. Answering Wh- Questions About Sentences and Text.

    ERIC Educational Resources Information Center

    Singer, Murray

    1986-01-01

    Describes a study designed to identify the mental operations that contribute to people's ability to answer wh- questions, that is, questions which request information that plays a particular role in relation to some action or event. Wh- questions are signaled by interrogative pronouns and adverbs like who, what, when, and where. (SED)

  13. Answers to Your Questions About American Indians.

    ERIC Educational Resources Information Center

    Bureau of Indian Affairs (Dept. of Interior), Washington, DC.

    Many of the frequent questions which arise concerning the relationship between Indians and the Federal Government are answered in this document. These questions and answers, in general, relate to Indians with whom the Federal government still retains a special relationship. Questions and answers pertain to the following areas: (1) the Indian…

  14. Wh- Questions and Individuals with Intellectual Disability

    ERIC Educational Resources Information Center

    Sanders, Eric

    2012-01-01

    The purpose of this study was to investigate the comprehension of questions beginning with different wh- question words presented in two referential conditions to individuals with intellectual disability (ID). Thirty-nine school-age participants completed a battery of who, what, where, when, why, and how questions with and without a picture…

  15. Memory, Knowledge, and the Answering of Questions.

    ERIC Educational Resources Information Center

    Norman, Donald A.

    An examination of the nature of memory reveals that the representation of knowledge cannot be separated from the uses of knowledge. The answering of questions is not a simple retrieval and response of stored information; rather the process is embedded in a general structural framework containing knowledge of the questioner, the question, and the…

  16. What Can We Learn from Students' Questions?

    ERIC Educational Resources Information Center

    Commeyras, Michelle

    1995-01-01

    Creating opportunities and encouraging student-centered questioning requires a special teacher-student dynamic. Students need to be empowered to ask questions. The article explores what teachers can learn from questions students ask, focusing on learning outcomes for teachers, and using a second-grade lesson on Harriet Tubman as an example. (SM)

  17. Questions That Science Teachers Find Difficult (II).

    ERIC Educational Resources Information Center

    Goodwin, Alan

    2003-01-01

    Presents some questions that science teachers find difficult. Focuses on three further questions relating to "simple" everyday situations that are normally explained in terms of the kinetic theory of matter. Identifies looking at the difference between chemical and physical changes as the most problematic question. (Author/YDS)

  18. Delivery of QTIiv2 Question Types

    ERIC Educational Resources Information Center

    Wills, Gary B.; Davis, Hugh C.; Gilbert, Lester; Hare, Jonathon; Howard, Yvonne; Jeyes, Steve; Millard, David; Sherratt, Robert

    2009-01-01

    The IMS Question and Test Interoperability (QTI) standard identifies 16 different question types which may be used in online assessment. While some partial implementations exist, the R2Q2 project has developed a complete solution that renders and responds to all 16 question types as specified. In addition, care has been taken in the R2Q2 project…

  19. How to Make Your Questions Essential

    ERIC Educational Resources Information Center

    Wiggins, Grant; Wilbur, Denise

    2015-01-01

    Good essential questions rarely emerge in the first draft. Common first-draft questions typically are convergent low-level questions designed to support content acquisition. They either point toward the one official "right" answer, or they elicit mere lists and thus no further inquiry. So how can teachers ensure that subsequent drafts…

  20. 47 CFR 13.215 - Question pools.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Question pools. 13.215 Section 13.215 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL RADIO OPERATORS Examination System § 13.215 Question pools. The question pool for each written examination element will be composed of...

  1. Teaching Students to Form Effective Questions

    ERIC Educational Resources Information Center

    Stafford, Tish

    2009-01-01

    The ability to question lies at the heart of human curiosity and is a necessary component of cognition. The author stresses that forming questions is essential to human thought and communication. As such, forming questions is a foundational process that cuts across curricular areas and is embedded in content standards across the nation, including…

  2. 32 CFR 316.7 - Questions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 2 2011-07-01 2011-07-01 false Questions. 316.7 Section 316.7 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) PRIVACY PROGRAM DEFENSE INFORMATION SYSTEMS AGENCY PRIVACY PROGRAM § 316.7 Questions. Questions on both the substance and procedure...

  3. 32 CFR 316.7 - Questions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 2 2014-07-01 2014-07-01 false Questions. 316.7 Section 316.7 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) PRIVACY PROGRAM DEFENSE INFORMATION SYSTEMS AGENCY PRIVACY PROGRAM § 316.7 Questions. Questions on both the substance and procedure...

  4. 32 CFR 316.7 - Questions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 2 2012-07-01 2012-07-01 false Questions. 316.7 Section 316.7 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) PRIVACY PROGRAM DEFENSE INFORMATION SYSTEMS AGENCY PRIVACY PROGRAM § 316.7 Questions. Questions on both the substance and procedure...

  5. 32 CFR 316.7 - Questions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 2 2013-07-01 2013-07-01 false Questions. 316.7 Section 316.7 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) PRIVACY PROGRAM DEFENSE INFORMATION SYSTEMS AGENCY PRIVACY PROGRAM § 316.7 Questions. Questions on both the substance and procedure...

  6. 32 CFR 316.7 - Questions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Questions. 316.7 Section 316.7 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) PRIVACY PROGRAM DEFENSE INFORMATION SYSTEMS AGENCY PRIVACY PROGRAM § 316.7 Questions. Questions on both the substance and procedure...

  7. The Contrast between Interrogatives and Questions.

    ERIC Educational Resources Information Center

    Huddleston, Rodney

    1994-01-01

    Explores the relation between interrogative, a category of grammatical form, and question, a category of meaning. Mismatches between interrogative phrases and questioned elements are also investigated. Two kinds of interrogative and three kinds of question are distinguished. (47 references) (Author/CK)

  8. Developing Qualitative Research Questions: A Reflective Process

    ERIC Educational Resources Information Center

    Agee, Jane

    2009-01-01

    The reflective and interrogative processes required for developing effective qualitative research questions can give shape and direction to a study in ways that are often underestimated. Good research questions do not necessarily produce good research, but poorly conceived or constructed questions will likely create problems that affect all…

  9. Teaching Culture: Questioning Perspectives on Our Practices

    ERIC Educational Resources Information Center

    Met, Myriam

    2010-01-01

    Despite years of training, teaching experience, reading professional literature, attending conferences, and learning from expert colleagues, when it comes to the teaching of culture, the author wishes she knew more answers to many critical questions. Her questions are framed by the basic questions that all curricula seek to answer: WHAT is the…

  10. Chronology, geochemistry, and petrology of a ferroan noritic anorthosite clast from Descartes breccia 67215: Clues to the age, origin, structure, and impact history of the lunar crust

    NASA Astrophysics Data System (ADS)

    Norman, M. D.; Borg, L. E.; Nyquist, L. E.; Bogard, D. D.

    2003-04-01

    The petrology, major and trace element geochemistry, and Nd-Ar-Sr isotopic compositions of a ferroan noritic anorthosite clast from lunar breccia 67215 have been studied in order to improve our understanding of the composition, age, structure, and impact history of the lunar crust. The clast (designated 67215c) has an unusually well preserved igneous texture. Mineral compositions are consistent with classification of 67215c as a member of the ferroan anorthositic suite of lunar highlands rocks, but the texture and mineralogy show that it cooled more rapidly and at shallower depths than did more typical ferroan anorthosites (FANs). Incompatible trace element concentrations are enriched in 67215c relative to typical FANs, but diagnostic signatures such as Ti/Sm, Sc/Sm, plagiophile element ratios, and the lack of Zr/Hf and Nb/Ta fractionation show that this cannot be due to the addition of KREEP. Alternatively, 67215c may contain a greater fraction of trapped liquid than is commonly present in lunar FANs. 147Sm-143Nd isotopic compositions of mineral separates from 67215c define an isochron age of 4.40 ± 0.11 Gyr with a near-chondritic initial 143Nd of +0.85 ± 0.53. The 40Ar-39Ar composition of plagioclase from this clast records a post-crystallization thermal event at 3.93 ± 0.08 Gyr, with the greatest contribution to the uncertainty in this age deriving from a poorly constrained correction for lunar atmosphere 40Ar. Rb-Sr isotopic compositions are disturbed, probably by the same event recorded by the Ar isotopic compositions. Trace element compositions of FANs are consistent with crystallization from a moderately evolved magma ocean and do not support a highly depleted source composition such as that implied by the positive initial 143Nd of the ferroan noritic anorthosite 62236. Alternatively, the Nd isotopic systematics of lunar FANs may have been subject to variable degrees of modification by impact metamorphism, with the plagioclase fraction being more strongly

  11. Analysis of Glioblastoma Patients' Plasma Revealed the Presence of MicroRNAs with a Prognostic Impact on Survival and Those of Viral Origin

    PubMed Central

    Herman, Ana; Gruden, Kristina; Blejec, Andrej; Podpečan, Vid; Motaln, Helena; Rožman, Primož; Hren, Matjaž; Zupančič, Klemen; Veber, Matija; Verbovšek, Urška; Lah Turnšek, Tamara; Porčnik, Andrej; Koršič, Marjan; Knežević, Miomir; Jeras, Matjaž

    2015-01-01

    Background Glioblastoma multiforme (GBM) is among the most aggressive cancers with a poor prognosis in spite of a plethora of established diagnostic and prognostic biomarkers and treatment modalities. Therefore, the current goal is the detection of novel biomarkers, possibly detectable in the blood of GBM patients that may enable an early diagnosis and are potential therapeutic targets, leading to more efficient interventions. Experimental Procedures MicroRNA profiling of 734 human and human-associated viral miRNAs was performed on blood plasma samples from 16 healthy individuals and 16 patients with GBM, using the nCounter miRNA Expression Assay Kits. Results We identified 19 miRNAs with significantly different plasma levels in GBM patients, compared to the healthy individuals group with the difference limited by a factor of 2. Additionally, 11 viral miRNAs were found differentially expressed in plasma of GBM patients and 24 miRNA levels significantly correlated with the patients’ survival. Moreover, the overlap between the group of candidate miRNAs for diagnostic biomarkers and the group of miRNAs associated with survival, consisted of ten miRNAs, showing both diagnostic and prognostic potential. Among them, hsa miR 592 and hsa miR 514a 3p have not been previously described in GBM and represent novel candidates for selective biomarkers. The possible signalling, induced by the revealed miRNAs is discussed, including those of viral origin, and in particular those related to the impaired immune response in the progression of GBM. Conclusion The GBM burden is reflected in the alteration of the plasma miRNAs pattern, including viral miRNAs, representing the potential for future clinical application. Therefore proposed biomarker candidate miRNAs should be validated in a larger study of an independent cohort of patients. PMID:25950799

  12. Excellent Outcomes and Lack of Prognostic Impact of Cell of Origin for Localized Diffuse Large B-cell Lymphoma in the Rituximab Era

    PubMed Central

    Kumar, Anita; Lunning, Matthew A.; Zhang, Zhigang; Migliacci, Jocelyn C.; Moskowitz, Craig H.; Zelenetz, Andrew D.

    2015-01-01

    Summary Therapeutic options for limited-stage diffuse large B cell lymphoma (DLBCL) include short- or full-course R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone) +/- radiotherapy. The optimal treatment remains unclear. The prognostic value of cell-of-origin (COO) in early stage DLBCL is unknown. Patients with limited-stage DLBCL (stage I or stage II, non-bulky) treated with R-CHOP +/- involved field radiotherapy (IFRT) from 1999 – 2012 were included. COO by the Hans algorithm was analysed in a subset of patients. Of 261 patients, 30% were stage I (N=82), 37% Stage IE (N=96), <1% stage IXEE (N=1), 18% stage II (N=46) and 14% Stage IIE (N=37). The stage-modified IPI stratified patients into prognostically relevant groups. There was no significant difference in progression-free survival (PFS) or overall survival (OS) for patients in the germinal centre B-cell-like (GCB; n=65) and non-GCB cohorts (n=22). Seventeen patients received R-CHOP x 3-4 cycles (Arm A), 147 received R-CHOP x 3-4 cycles + IFRT (Arm B), 48 received R-CHOP x6 cycles (Arm C), and 50 received R-CHOP x6 cycles +IFRT (Arm D). The outcomes were excellent, with 5-year PFS of 82% and 5-year OS of 93%, and were similar across the 4 treatment groups. In the rituximab era, outcomes for limited-stage DLBCL, regardless of treatment approach, were excellent. Baseline COO was not a significant prognostic factor in patients treated with short-course R-CHOP + IFRT. PMID:26456939

  13. Impact of sludge stabilization processes and sludge origin (urban or hospital) on the mobility of pharmaceutical compounds following sludge landspreading in laboratory soil-column experiments.

    PubMed

    Lachassagne, Delphine; Soubrand, Marilyne; Casellas, Magali; Gonzalez-Ospina, Adriana; Dagot, Christophe

    2015-11-01

    This study aimed to determine the effect of sludge stabilization treatments (liming and anaerobic digestion) on the mobility of different pharmaceutical compounds in soil amended by landspreading of treated sludge from different sources (urban and hospital). The sorption and desorption potential of the following pharmaceutical compounds: carbamazepine (CBZ), ciprofloxacin (CIP), sulfamethoxazole (SMX), salicylic acid (SAL), ibuprofen (IBU), paracetamol (PAR), diclofenac (DIC), ketoprofen (KTP), econazole (ECZ), atenolol (ATN), and their solid-liquid distribution during sludge treatment (from thickening to stabilization) were investigated in the course of batch testing. The different sludge samples were then landspread at laboratory scale and leached with an artificial rain simulating 1 year of precipitation adapted to the surface area of the soil column used. The quality of the resulting leachate was investigated. Results showed that ibuprofen had the highest desorption potential for limed and digested urban and hospital sludge. Ibuprofen, salicylic acid, diclofenac, and paracetamol were the only compounds found in amended soil leachates. Moreover, the leaching potential of these compounds and therefore the risk of groundwater contamination depend mainly on the origin of the sludge because ibuprofen and diclofenac were present in the leachates of soils amended with urban sludge, whereas paracetamol and salicylic acid were found only in the leachates of soils amended with hospital sludge. Although carbamazepine, ciprofloxacin, sulfamethoxazole, ketoprofen, econazole, and atenolol were detected in some sludge, they were not present in any leachate. This reflects either an accumulation and/or (bio)degradation of these compounds (CBZ, CIP, SMX, KTP, ECZ, and ATN ), thus resulting in very low mobility in soil. Ecotoxicological risk assessment, evaluated by calculating the risk quotients for each studied pharmaceutical compound, revealed no high risk due to the

  14. Assessment of PM₂.₅ and PM₁ chemical profile in a multiple-impacted Mediterranean urban area: origin, sources and meteorological dependence.

    PubMed

    Pateraki, St; Asimakopoulos, D N; Bougiatioti, A; Maggos, Th; Vasilakos, Ch; Mihalopoulos, N

    2014-05-01

    Airborne particulate matter in the PM2.5 and PM1 size ranges has been sampled at three sites within the Mediterranean urban area of the Athens Basin, representing background, roadside-industrialized and coastal background locations. With the principal aim to identify the sources and discriminate the contribution of the regional input versus the local one, simultaneous chemical characterization with respect to carbonaceous and ionic species was also carried out on the collected samples. In general, the average recorded values were within the Mediterranean concentration range. The constant prevalence of the ionic mass (52%-79%) over one of the carbonaceous, being combined with the occurrence of its maximum rates at the coastal background environment (74%-79% and 73%-77% for PM2.5 and PM1, respectively) leads to the hypothesis that the fine PM pollution in the basin, especially for the remote locations, is evidently governed by the external intrusion. Even at the polluted atmosphere of the roadside-industrialized environment, the PM mass was regionally originated, with the corresponding input reaching up to 87% (northward flow). Applying factor analysis on the PM2.5 database it came obvious that the sources which were responsible for the configured PM burden were not fully differentiated not only between the different types of environment but also between the exceedances and the clean air events. The contribution of the secondary, marine and combustion processes was constant at all the stations of the network, while a continuous input of crustal particles characterized both the roadside-industrialized and the coastal atmosphere. Finally, the episodic values show a general common signal of secondary mixed ΡΜ emissions, high influence of both regional and local pollution spikes, confirming the earlier findings for the significance of transportation.

  15. Medical Marijuana: More Questions than Answers

    PubMed Central

    Hill, Kevin P.

    2014-01-01

    With 23 states and the District of Columbia having enacted medical marijuana laws as of August 2014, it is important that psychiatrists be able to address questions about medical marijuana from patients, families, and other health care professionals. The author discusses the limited medical literature on synthetic cannabinoids and medical marijuana. The synthetic cannabinoids dronabinol and nabilone are approved by the United States Food and Drug Administration for nausea and vomiting associated with cancer chemotherapy and appetite stimulation in patients with wasting diseases such as acquired immunodeficiency syndrome (AIDS). Results of clinical trials of these agents for other conditions have varied widely thus far. In addition, few data are available on the use of the marijuana plant as a medical treatment. The author concludes that there is a clear need for additional research on possible medical uses of cannabinoids. He notes that discussions with prospective medical marijuana patients should emphasize the importance of communication among all parties due to the possible side effects of treatment with marijuana and its potential to interact with other medications the patient may be taking. Facilitating a thorough substance abuse consultation is one of most positive ways that psychiatrists, especially addiction psychiatrists, can make an impact as medical marijuana becomes increasingly common. A careful review of the prospective medical marijuana user's substance use history, co-occurring medical and psychiatric conditions, family history, and psychosocial stressors is essential in evaluating the potential risks of medical marijuana for these patients. The author concludes that psychiatrists can have a significant impact by increasing the likelihood that medical marijuana will be used in a safe and responsible way. PMID:25226202

  16. The origin of grasslands in the temperate forest zone of east-central Europe: long-term legacy of climate and human impact

    NASA Astrophysics Data System (ADS)

    Kuneš, Petr; Svobodová-Svitavská, Helena; Kolář, Jan; Hajnalová, Mária; Abraham, Vojtěch; Macek, Martin; Tkáč, Peter; Szabó, Péter

    2015-05-01

    The post-glacial fate of central European grasslands has stimulated palaeoecological debates for a century. Some argued for the continuous survival of open land, while others claimed that closed forest had developed during the Middle Holocene. The reasons behind stability or changes in the proportion of open land are also unclear. We aim to reconstruct regional vegetation openness and test the effects of climate and human impact on vegetation change throughout the Holocene. We present a newly dated pollen record from north-western fringes of the Pannonian Plain, east-central Europe, and reconstruct Holocene regional vegetation development by the REVEALS model for 27 pollen-equivalent taxa. Estimated vegetation is correlated in the same area with a human activity model based on all available archaeological information and a macrophysical climate model. The palaeovegetation record indicates the continuous presence of open land throughout the Holocene. Grasslands and open woodlands were probably maintained by local arid climatic conditions during the early Holocene delaying the spread of deciduous (oak) forests. Significantly detectable human-made landscape transformation started only after 2000 BC. Our analyses suggest that Neolithic people spread into a landscape that was already open. Humans probably contributed to the spread of oak, and influenced the dynamics of hazel and hornbeam.

  17. Preschool Word Learning during Joint Book Reading: Effect of Adult Questions and Comments

    ERIC Educational Resources Information Center

    Ard, Lisa M.; Beverly, Brenda L.

    2004-01-01

    Adults naturally comment and pose questions during joint book reading (JBR), a recognized context for vocabulary acquisition. An original story containing 10 nonsense words mapped to novel referents was read to 40 typically developing preschoolers. Children who heard scripted questions and comments identified approximately two more words than…

  18. Effects of Re-Using a Conceptual Examination Question in Physics

    ERIC Educational Resources Information Center

    Sharma, Manjula D.; Sefton, Ian M.; Cole, Martyn; Whymark, Aaron; Millar, Rosemary M.; Smith, Andrew

    2005-01-01

    We report on a study of what happened when we recycled a conceptual examination question in a first-year university physics course. The question, which was used for three consecutive years, asked about an astronaut's experience of weighing in an orbiting space-craft. The original intention was to use a phenomenographic approach to look for…

  19. Planetary protection - some legal questions

    NASA Astrophysics Data System (ADS)

    Fasan, E.

    2004-01-01

    When we legally investigate the topic of Planetary Protection, we have to realise that there are primarily two very distinct parts of our juridical work: We have to study lexlata, theexistingapplicableLaw, especially Space Law, and also lexferenda, whatshouldbethe law . With this in mind, we have to deliberate the legal meaning of the notions "Planetary", and "Protection". About " Planetary": Our own Earth is our most important planet. At present only here do exist human beings, who are sensu strictu the only legal subjects. We make the law, we have to apply it, and we are to be protected as well as bound by it. But what is further meant by "Planetary"? Is it planets in an astronomical sense only, the nine planets which revolve around our fixed star, namely the sun, or is it also satellites, moving around most of these planets, as our own Moon circles Earth. "The Moon and other Celestial Bodies (C.B.)" are subject to Space Law, especially to International Treaties, Agreements, Resolutions of the UN, etc. I propose that they and not only the planets in an strictly astronomical sense are to be protected. But I do not think that the said notion also comprises asteroids, comets, meteorites, etc. although they too belong to our solar system. Our investigation comes to the result that such bodies have a different (lesser) legal quality. Also we have to ask Protectionfrom what ? From: Natural bodies - Meteorites, NEO Asteroids, Comets which could hit Earth or C.B.Artificial Objects: Space Debris threatening especially Earth and near Earth orbits.Terrestrial Life - no infection of other celestial bodies. Alien life forms which could bring about "harmful contamination" of Earth and the life, above all human life, there, etc. Here, astrobiological questions have to be discussed. Special realms on C.B. which should be protected from electronic "noise" such as craters SAHA or Deadalus on the Moon, also taking into account the "Common Heritage" Principle. Then, we have to

  20. Planetary protection - some legal questions

    NASA Astrophysics Data System (ADS)

    Fasan, E.

    When we legally investigate the topic of Planetary Protection, we have to realise that there are primarily two very distinct parts of our juridical work: We have to study lex lata, the existing applicable Law, especially Space Law, and also lex ferenda, what should be the law. With this in mind, we have to deliberate the legal meaning of "Planetary", and of "Protection". About "Planetary": Our own Earth is the most important planet. At present only here do exist human beings, who are sensu strictu the only legal subjects. We make the law, we have to apply it, and we are to be protected as well as bound by it. Then, we have to discuss what is further meant by "Planetary": Is it planets in an astronomical sense only, the nine planets which revolve around our fixed star, namely the sun, or is it also satellites, moving around most of these planets, as our own Moon circles Earth. "The Moon and other Celestial Bodies (C.B)" are subject to Space Law, especially to International Treaties, Agreements, Resolutions of the UN etc. I propose that they and not only the planets in an strictly astronomical sense are to be protected. But I do not think that the said notion also comprises asteroids, comets, meteorites etc. although they too belong to our solar system. Our investigation comes to the result that such bodies have a different (lesser) legal quality. Also we have to ask Protection from what? From: Natural bodies - Meteorites, NEO Asteroids, Comets which could hit Earth or C.B. Artificial Objects: Space Debris threatening especially Earth and near Earth orbits. Terrestrial Life - no infection of other celestial bodies. Alien life forms which could bring about "harmful contamination" of Earth and the life, above all human life, there etc. Here, astrobiological questions have to be discussed. Special realms on C.B. which should be protected from Electronic "Noise" such as craters SAHA or Deadalus on the Moon, also taking into account the "Common Heritage" Principle. Then

  1. Introducing human papillomavirus vaccines - questions remain.

    PubMed

    Paavonen, Jorma; Lehtinen, Matti

    2008-01-01

    Genital human papillomavirus (HPV) infection and HPV-associated cervical and other anogenital cancers are significant public health problems. HPV 16 and HPV 18 are responsible for approximately 70% of all invasive cervical cancers worldwide. The first prophylactic HPV virus-like particle (VLP) vaccine against HPV types 6/11/16/18 was licensed in 2006 for girls and women aged 9-26 years. The second prophylactic HPV vaccine against HPV types 16 and 18 has been licensed this year. These vaccines are almost 100% effective in preventing infection and high-grade precancer associated with the HPV types included in the vaccine. The vaccines are well tolerated, safe, and highly immunogenic when given in three doses within 6 months. Efficacy of the vaccine against external vulvar and HPV-related vaginal lesions is also high. Even though the vaccine is highly effective against high-grade cervical, vaginal, or vulvar precancers, this only applies to women unexposed to these HPV types and only to high-grade intraepithelial lesions caused by these HPV types. Therefore, it is important to understand that the population impact of the vaccines will be much lower than vaccinating naive populations. Implementing HPV vaccine is a great opportunity but also a great challenge. However, mandatory HPV vaccination may raise many questions, and more answers are needed.

  2. 19 Urban Questions: Teaching in the City. Second Edition. Counterpoints: Studies in Postmodern Theory of Education, Vol. 215

    ERIC Educational Resources Information Center

    Steinberg, Shirley R., Ed

    2010-01-01

    The second edition of "19 Urban Questions: Teaching in the City" adds new questions to those in the original volume. Continuing the developing conversation in urban education, the book is provocative in style and rich in detail. Emphasizing the complexity of urban education, Shirley R. Steinberg and the authors ask direct questions about what…

  3. Observe-reflect-act: The cycle of reflective practice on questioning in STEM education

    NASA Astrophysics Data System (ADS)

    Ginley, Erica

    Countless studies have been conducted on questioning techniques in education. However, little research has been focused on the use of reflective practice in relation to teachers' questioning techniques in STEM: Science, Technology, Engineering and Math education. Within this action research study of my own teaching, six lessons were taught, observed, and reflected upon. The main focus was on whether and how reflective practice influences questioning. Through the analysis of video footage, conversation transcriptions, reflective journal entries, pre-service teacher survey, and student work, the importance of different questioning techniques became apparent. They demonstrated that reflective practice has an impact on improving questioning skills and, thus, better engaging students in the learning process.

  4. Vertical distribution of soil organic carbon originated from a prior peatland in Greece and impacts on the landscape, after conversion to arable land

    NASA Astrophysics Data System (ADS)

    Kayrotis, Theodore; Charoulis, A.; Vavoulidou, E.; Tziouvalekas, M.

    2010-05-01

    The vertical distribution and the status of soil organic carbon (Corg.) in 66 surface and subsurface soil samples were investigated. These soils originated mainly from organic deposits of Philippoi (northern Greece) have been classified as Histosols and belong to the suborder of Saprists. The present study consisted of an area of 10,371 ha where about 90% of the soils are organic. The main crops are maize (Zea mays L.), sugar beets (Beta vulgaris L.), tobacco (Nicotiana tabacum L.), cotton (Gossypium hirsutum L.), tomatoes (Lycopersicon esculentum Mill.), and wheat (Triticum aestivum L.).The surface horizons consist mainly of well-humified organic materials mixed with mineral soil particles. Usually, they have moderate or insufficient drainage regime and conditions become favorable for microbial growth. Microbes decompose and transform the soil organic compounds into mineral forms, which are then available as nutrients for the crop. The organic matter was derived primarily from Cyperaceae (Cladium mariscus, various Carex species, etc.) and from decomposed residues of arable crops. The dominant features of these soils are the high content of organic matter and the obvious stratification of soil horizons. In contrast, most arable soils in Greece are characterized by low organic matter content. The stratification differentiates the physical and chemical properties and the groundwater table even during dry summers lies at depths,150 cm beneath surface. The Corg. content was high and varied greatly among the examined samples. In the surface layers ranged between 3.57 and 336.50 g kg2 (mean 199.26 g kg2) and between 22.10 and 401.10 g kg2 in the subsurface horizons (mean 258.89 g kg2). It can be argued that surface layers are drier and part of soil organic matter was seriously affected by the process of oxidation. At drier sites, soil subsidence was appeared as a consequence of soil organic matter oxidation. Increased contents were found in the northern part of the

  5. Explaining topic prevalence in answers to open-ended survey questions about climate change

    NASA Astrophysics Data System (ADS)

    Tvinnereim, Endre; Fløttum, Kjersti

    2015-08-01

    Citizens’ opinions are crucial for action on climate change, but are, owing to the complexity of the issue, diverse and potentially unformed. We contribute to the understanding of public views on climate change and to knowledge needed by decision-makers by using a new approach to analyse answers to the open survey question `what comes to mind when you hear the words `climate change’?’. We apply automated text analysis, specifically structural topic modelling, which induces distinct topics based on the relative frequencies of the words used in 2,115 responses. From these data, originating from the new, nationally representative Norwegian Citizen Panel, four distinct topics emerge: Weather/Ice, Future/Impact, Money/Consumption and Attribution. We find that Norwegians emphasize societal aspects of climate change more than do respondents in previous US and UK studies. Furthermore, variables that explain variation in closed questions, such as gender and education, yield different and surprising results when employed to explain variation in what respondents emphasize. Finally, the sharp distinction between scepticism and acceptance of conventional climate science, often seen in previous studies, blurs in many textual responses as scepticism frequently turns into ambivalence.

  6. Petrography and geochemistry of distal spherules from the K-Pg boundary in the Umbria-Marche region (Italy) and their origin as fractional condensates and melts in the Chicxulub impact plume

    NASA Astrophysics Data System (ADS)

    Belza, J.; Goderis, S.; Montanari, A.; Vanhaecke, F.; Claeys, P.

    2017-04-01

    The impact spherules from the distal K-Pg boundary sections are considered to represent silicate droplets condensed and solidified from a laterally expanding, cooling vapor plume formed upon hypervelocity impact. In the present-day Cretaceous-Paleogene boundary (K-Pg) spherule population of the Umbria-Marche region in Italy, three texturally and compositionally distinct types of impact spherules can be identified that are dominantly composed of (1) goethite, (2) K-feldspar or (3) glauconite. Although these phases represent the products of diagenetic alteration, the remnant textural characteristics of the spherules and the type of alteration product are indicative of the spherules' original compositions, which are important to constrain the physicochemical conditions prevalent throughout the impact vapor plume. The presence of relict ghost crystals and the identification of 'iddingsite' indicate that goethite likely represents pseudomorphic replacement after olivine. Goethite spherules contain numerous dendritic, euhedral and skeletal spinel crystals variably dispersed in the groundmass. In terms of textures, five types of goethite spherules can be distinguished, showing striking similarities to chondrules: (I) skeletal, (II) barred, (III) radial/barred, (IV) porphyritic and (V) relict/granular. The morphology of both spinel and olivine (pseudomorphs) is consistent with established formation conditions (peak temperature Tmax, degree of supercooling ΔT, cooling rate, presence of nucleation sites) for different chondrule textural types. As goethite spherules are anomalously enriched in moderately to highly refractory lithophile (Sc, V, Y, Zr, Nb, REE, Hf, Ta, Th) and siderophile (Cr, Co, Ni, W, Ir, Pt) elements, they are interpreted to represent (diagenetically altered) refractory (high-T) condensation products from a well-homogenized plume consisting of both vaporized target and projectile matter. Different from goethite spherules, K-feldspar spherules exhibit

  7. 150 Student Questions on Solar Physics

    NASA Astrophysics Data System (ADS)

    Lopez, R. E.; Gross, N. A.; Knipp, D. J.

    2010-12-01

    The Center for Integrated Space Weather Modeling (CISM) holds a two-week Space Weather Summer School for introductory graduate students and space weather professionals to gain a system level understanding of the space environment and the effects of space weather. A typical day in the summer school consists of three morning lectures followed by an afternoon lab session. After the morning lectures, the participants are each asked to submit a question about the mornings topics on a question card. The lecturers then take the time to answer these questions prior to afternoon sessions. In the last 5 years over 1000 such question cards have been collected and cataloged. Despite detailed lectures by experts similar questions appear every year. We have analyzed over 150 questions related to the introductory lectures on solar physics and solar activity. Questions content was categorized using the AGU Index, and question sophistication was categorized using Bloom’s Taxonomy of Educational Objectives. Specific analysis results along with lists of questions will be presented. We hope that these results can be used to improve the lecture and classroom content and allow students to move beyond low level education objectives and ask more sophisticated questions.

  8. Modern human origins: progress and prospects.

    PubMed Central

    Stringer, Chris

    2002-01-01

    The question of the mode of origin of modern humans (Homo sapiens) has dominated palaeoanthropological debate over the last decade. This review discusses the main models proposed to explain modern human origins, and examines relevant fossil evidence from Eurasia, Africa and Australasia. Archaeological and genetic data are also discussed, as well as problems with the concept of 'modernity' itself. It is concluded that a recent African origin can be supported for H. sapiens, morphologically, behaviourally and genetically, but that more evidence will be needed, both from Africa and elsewhere, before an absolute African origin for our species and its behavioural characteristics can be established and explained. PMID:12028792

  9. Effect of lecture instruction on student performance on qualitative questions

    NASA Astrophysics Data System (ADS)

    Heron, Paula R. L.

    2015-06-01

    The impact of lecture instruction on student conceptual understanding in physics has been the subject of research for several decades. Most studies have reported disappointingly small improvements in student performance on conceptual questions despite direct instruction on the relevant topics. These results have spurred a number of attempts to improve learning in physics courses through new curricula and instructional techniques. This paper contributes to the research base through a retrospective analysis of 20 randomly selected qualitative questions on topics in kinematics, dynamics, electrostatics, waves, and physical optics that have been given in introductory calculus-based physics at the University of Washington over a period of 15 years. In some classes, questions were administered after relevant lecture instruction had been completed; in others, it had yet to begin. Simple statistical tests indicate that the average performance of the "after lecture" classes was significantly better than that of the "before lecture" classes for 11 questions, significantly worse for two questions, and indistinguishable for the remaining seven. However, the classes had not been randomly assigned to be tested before or after lecture instruction. Multiple linear regression was therefore conducted with variables (such as class size) that could plausibly lead to systematic differences in performance and thus obscure (or artificially enhance) the effect of lecture instruction. The regression models support the results of the simple tests for all but four questions. In those cases, the effect of lecture instruction was reduced to a nonsignificant level, or increased to a significant, negative level when other variables were considered. Thus the results provide robust evidence that instruction in lecture can increase student ability to give correct answers to conceptual questions but does not necessarily do so; in some cases it can even lead to a decrease.

  10. Question Classification Taxonomies as Guides to Formulating Questions for Use in Chemistry Classrooms

    ERIC Educational Resources Information Center

    Festo, Kayima

    2016-01-01

    Teacher questions play an important role in facilitating classroom discourse. Using appropriate question types and proper questioning techniques help to create reflective-active learners. Teacher questions can elicit students' explanations, elaboration of their ideas and thinking, and they can be used to disclose students' misconceptions. Despite…

  11. Correlation between Question Intonation and Focus of Interrogation--Evidence from French Dislocated Questions.

    ERIC Educational Resources Information Center

    Shen, Xiao-nan

    This study explores the relationship between question intonation patterns in French using dislocated questions and question-focus (Q- focus). A dislocated question is defined as an interrogative sentence whose sequence is interrupted by the topicalization of a constituent at the left ("Toi, tu viens?"), at the right (Tu viens,…

  12. Is There a Relationship between Chemistry Performance and Question Type, Question Content and Gender?

    ERIC Educational Resources Information Center

    Hudson, Ross D.

    2012-01-01

    This research inquires into the effectiveness of the two predominant forms of questions--multiple-choice questions and short-answer questions--used in the State University Entrance Examination for Chemistry including the relationship between performance and gender. It examines not only the style of question but also the content type examined…

  13. Military Medical Care: Questions and Answers

    DTIC Science & Technology

    2008-05-20

    Order Code RL33537 Military Medical Care : Questions and Answers Updated May 20, 2008 Richard A. Best Jr. Specialist in National Defense Foreign...control number. 1. REPORT DATE 20 MAY 2008 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Military Medical Care : Questions and...8-98) Prescribed by ANSI Std Z39-18 Military Medical Care : Questions and Answers Summary The primary mission of the military health system, which

  14. Critical Questions for Space Human Factors

    NASA Technical Reports Server (NTRS)

    Woolford, Barbara; Bagian, Tandi

    2000-01-01

    crews. Yet prioritizing the research that can and should be done by NASA will be based on the critical nature of the issues, and the impact of the individual research questions on mission design. The risks to crew health and safety associated with answering critical human factors issues must be properly included and communicated in order to support the Agency's decisions regarding future space programs.

  15. The Origin of Mercury

    NASA Astrophysics Data System (ADS)

    Benz, W.; Anic, A.; Horner, J.; Whitby, J. A.

    Mercury's unusually high mean density has always been attributed to special circumstances that occurred during the formation of the planet or shortly thereafter, and due to the planet's close proximity to the Sun. The nature of these special circumstances is still being debated and several scenarios, all proposed more than 20 years ago, have been suggested. In all scenarios, the high mean density is the result of severe fractionation occurring between silicates and iron. It is the origin of this fractionation that is at the centre of the debate: is it due to differences in condensation temperature and/or in material characteristics (e.g. density, strength)? Is it because of mantle evaporation due to the close proximity to the Sun? Or is it due to the blasting off of the mantle during a giant impact?

  16. The Origin of Mercury

    NASA Astrophysics Data System (ADS)

    Benz, W.; Anic, A.; Horner, J.; Whitby, J. A.

    2007-10-01

    Mercury’s unusually high mean density has always been attributed to special circumstances that occurred during the formation of the planet or shortly thereafter, and due to the planet’s close proximity to the Sun. The nature of these special circumstances is still being debated and several scenarios, all proposed more than 20 years ago, have been suggested. In all scenarios, the high mean density is the result of severe fractionation occurring between silicates and iron. It is the origin of this fractionation that is at the centre of the debate: is it due to differences in condensation temperature and/or in material characteristics (e.g. density, strength)? Is it because of mantle evaporation due to the close proximity to the Sun? Or is it due to the blasting off of the mantle during a giant impact? In this paper we investigate, in some detail, the fractionation induced by a giant impact on a proto-Mercury having roughly chondritic elemental abundances. We have extended the previous work on this hypothesis in two significant directions. First, we have considerably increased the resolution of the simulation of the collision itself. Second, we have addressed the fate of the ejecta following the impact by computing the expected reaccretion timescale and comparing it to the removal timescale from gravitational interactions with other planets (essentially Venus) and the Poynting Robertson effect. To compute the latter, we have determined the expected size distribution of the condensates formed during the cooling of the expanding vapor cloud generated by the impact. We find that, even though some ejected material will be reaccreted, the removal of the mantle of proto-Mercury following a giant impact can indeed lead to the required long-term fractionation between silicates and iron and therefore account for the anomalously high mean density of the planet. Detailed coupled dynamical chemical modeling of this formation mechanism should be carried out in such a way as to

  17. 47 CFR 97.523 - Question pools.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Question pools. 97.523 Section 97.523 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Qualifying Examination Systems § 97.523 Question pools. All VECs must cooperate in maintaining...

  18. 47 CFR 97.523 - Question pools.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Question pools. 97.523 Section 97.523 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Qualifying Examination Systems § 97.523 Question pools. All VECs must cooperate in maintaining...

  19. 47 CFR 97.523 - Question pools.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Question pools. 97.523 Section 97.523 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Qualifying Examination Systems § 97.523 Question pools. All VECs must cooperate in maintaining...

  20. 47 CFR 97.523 - Question pools.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Question pools. 97.523 Section 97.523 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Qualifying Examination Systems § 97.523 Question pools. All VECs must cooperate in maintaining...