WorldWideScience

Sample records for terrestrial analog studies

  1. Terrestrial Analogs to Mars

    Science.gov (United States)

    Farr, T. G.; Arcone, S.; Arvidson, R. W.; Baker, V.; Barlow, N. G.; Beaty, D.; Bell, M. S.; Blankenship, D. D.; Bridges, N.; Briggs, G.; Bulmer, M.; Carsey, F.; Clifford, S. M.; Craddock, R. A.; Dickerson, P. W.; Duxbury, N.; Galford, G. L.; Garvin, J.; Grant, J.; Green, J. R.; Gregg, T. K. P.; Guinness, E.; Hansen, V. L.; Hecht, M. H.; Holt, J.; Howard, A.; Keszthelyi, L. P.; Lee, P.; Lanagan, P. D.; Lentz, R. C. F.; Leverington, D. W.; Marinangeli, L.; Moersch, J. E.; Morris-Smith, P. A.; Mouginis-Mark, P.; Olhoeft, G. R.; Ori, G. G.; Paillou, P.; Reilly, J. F., II; Rice, J. W., Jr.; Robinson, C. A.; Sheridan, M.; Snook, K.; Thomson, B. J.; Watson, K.; Williams, K.; Yoshikawa, K.

    2002-08-01

    It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing. These studies include field workshops, characterization of terrestrial analog sites, instrument tests, laboratory measurements (including analysis of Martian meteorites), and computer and laboratory modeling. The combination of all these activities allows scientists to constrain the processes operating in specific terrestrial environments and extrapolate how similar processes could affect Mars. The Terrestrial Analogs for Mars Community Panel has considered the following two key questions: (1) How do terrestrial analog studies tie in to the Mars Exploration Payload Assessment Group science questions about life, past climate, and geologic evolution of Mars, and (2) How can future instrumentation be used to address these questions. The panel has considered the issues of data collection, value of field workshops, data archiving, laboratory measurements and modeling, human exploration issues, association with other areas of solar system exploration, and education and public outreach activities.

  2. Terrestrial Spaceflight Analogs: Antarctica

    Science.gov (United States)

    Crucian, Brian

    2013-01-01

    Alterations in immune cell distribution and function, circadian misalignment, stress and latent viral reactivation appear to persist during Antarctic winterover at Concordia Station. Some of these changes are similar to those observed in Astronauts, either during or immediately following spaceflight. Others are unique to the Concordia analog. Based on some initial immune data and environmental conditions, Concordia winterover may be an appropriate analog for some flight-associated immune system changes and mission stress effects. An ongoing smaller control study at Neumayer III will address the influence of the hypoxic variable. Changes were observed in the peripheral blood leukocyte distribution consistent with immune mobilization, and similar to those observed during spaceflight. Alterations in cytokine production profiles were observed during winterover that are distinct from those observed during spaceflight, but potentially consistent with those observed during persistent hypobaric hypoxia. The reactivation of latent herpesviruses was observed during overwinter/isolation, that is consistently associated with dysregulation in immune function.

  3. A half-century of terrestrial analog studies: From craters on the Moon to searching for life on Mars

    Science.gov (United States)

    Léveillé, Richard

    2010-03-01

    Terrestrial analogs to the Moon and Mars have been used to advance knowledge in planetary science for over a half-century. They are useful in studies of comparative geology of the terrestrial planets and rocky moons, in astronaut training and testing of exploration technologies, and in developing hypotheses and exploration strategies in astrobiology. In fact, the use of terrestrial analogs can be traced back to the origins of comparative geology and astrobiology, and to the early phases of the Apollo astronaut program. Terrestrial analog studies feature prominently throughout the history of both NASA and the USGS' Astrogeology Research Program. In light of current international plans for a return missions to the Moon, and eventually to send sample return and manned missions to Mars, as well as the recent creation of various analog research and development programs, this historical perspective is timely.

  4. NASA HRP Immunology Discipline - Use of Terrestrial Analogs

    Science.gov (United States)

    Crucian, Brian

    2014-01-01

    Due to the cost and operational constraints, as well as technical implementation limitations, it is desirous to perform relevant space physiology investigations first in terrestrial 'space analogs'. This is particularly true for initial investigations, which may then provide appropriate focus for subsequent flight investigations, or for mechanistic investigations that simply cannot be performed during spaceflight. Appropriate analog choice is extremely important. There are a wide variety of terrestrial space analogs, each relevant to a particular physiological discipline (or disciplines) and each with a particular fidelity (or lack thereof) to spaceflight, and each with unique operational constraints. The HRP Immunology Discipline is tasked with managing the HRP Risk concerning clinical risk for Astronaut crews related to spaceflight-associated immune dysregulation. Such dysregulation has been documented to occur during spaceflight, and found to persist for the duration of a 6-month ISS mission. Studies continue to characterize the onorbit phenomenon, but it generally consists of diminished immunocyte function, dysregulated cytokine profiles, and persistent herpesvirus reactivation. Causes are thought to synergistically include microgravity, psychological or physiological stress, radiation, and/or circadian misalignment. An appropriate terrestrial analog for immune dysregulation would replicate as many of these influences as possible. Such analogs may include clinostat or bioreactor cell culture (microgravity), hindlimb suspension (stress, fluid shifts, hypokinesis), or human deployment to remote or extreme environments (isolation, stress, circadian). Also, the laboratory setting may be used as an analog, or to augment analogs, such as sleep deprivation/misalignment or human centrifugation to replicate gravitational stress. As an appropriate example of a NASA Disciplines use of Terrestrial space analogs, this talk will discuss spaceflight associated immune

  5. Terrestrial Analogs to Mars: NRC Community Panel Decadal Report

    Science.gov (United States)

    Farr, T. G.

    2002-12-01

    A report was completed recently by a Community Panel for the NRC Decadal Study of Solar System Exploration. The desire was for a review of the current state of knowledge and for recommendations for action over the next decade. The topic of this panel, Terrestrial Analogs to Mars, was chosen to bring attention to the need for an increase in analog studies in support of the increased pace of Mars exploration. It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing. These studies include field workshops, characterization of terrestrial analog sites, instrument tests, laboratory measurements (including analysis of martian meteorites), and computer and laboratory modeling. The combination of all of these activities allows scientists to constrain the processes operating in specific terrestrial environments and extrapolate how similar processes could affect Mars. The Terrestrial Analogs for Mars Community Panel has considered the following two key questions: (1) How do terrestrial analog studies tie in to the overarching science questions about life, past climate, and geologic evolution of Mars, and (2) How can future instrumentation be used to address these questions. The panel considered the issues of data collection and archiving, value of field workshops, laboratory measurements and modeling, human exploration issues, association with other areas of solar system exploration, and education and public outreach activities. Parts of this work were performed under contract to NASA.

  6. Community Decadal Panel for Terrestrial Analogs to Mars

    Science.gov (United States)

    Barlow, N. G.; Farr, T.; Baker, V. R.; Bridges, N.; Carsey, F.; Duxbury, N.; Gilmore, M. S.; Green, J. R.; Grin, E.; Hansen, V.; Keszthelyi, L.; Lanagan, P.; Lentz, R.; Marinangeli, L.; Morris, P. A.; Ori, G. G.; Paillou, P.; Robinson, C.; Thomson, B.

    2001-11-01

    It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing. These studies include field workshops, characterization of terrestrial analog sites for Mars, instrument tests, laboratory measurements (including analysis of martian meteorites), and computer and laboratory modeling. The combination of all these activities allows scientists to constrain the processes operating in specific terrestrial environments and extrapolate how similar processes could affect Mars. The Terrestrial Analogs for Mars Community Panel is considering the following two key questions: (1) How do terrestrial analog studies tie in to the MEPAG science questions about life, past climate, and geologic evolution of Mars, and (2) How can future instrumentation be used to address these questions. The panel is considering the issues of data collection, value of field workshops, data archiving, laboratory measurements and modeling, human exploration issues, association with other areas of solar system exploration, and education and public outreach activities.

  7. Terrestrial studies

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Tritium in the organic fraction of soil, separated as water by high temperature combustion, was 5 to 50 times higher in activity than water that was freeze-dried from the same samples. The 50-year dose commitment from ingestion of crops is not influenced significantly by the plutonium in the SRP environment. This plutonium is a result of more than 20 years of operating chemical separations facilities. Techniques were developed to detect as little as 0.02 pCi/m 2 of iodine-129 and 0.2 pg of technetium-99 in soil to evaluate environmental effects. A sensitive three-stage mass spectrometer was completed for use in environmental studies of transuranium elements. Results of monitoring particle size distribution of entrapped particles containing Pu-238, and Pu-239,240 are reported

  8. SEARCHING FOR THE SIGNATURES OF TERRESTRIAL PLANETS IN SOLAR ANALOGS

    International Nuclear Information System (INIS)

    Gonzalez Hernandez, J. I.; Israelian, G.; Delgado-Mena, E.; Santos, N. C.; Sousa, S.; Neves, V.; Udry, S.

    2010-01-01

    We present a fully differential chemical abundance analysis using very high resolution (λ/δλ ∼> 85, 000) and very high signal-to-noise (S/N ∼800 on average) HARPS and UVES spectra of 7 solar twins and 95 solar analogs, of which 24 are planet hosts and 71 are stars without detected planets. The whole sample of solar analogs provides very accurate Galactic chemical evolution trends in the metallicity range -0.3 < [Fe/H] < 0.5. Solar twins with and without planets show similar mean abundance ratios. We have also analyzed a sub-sample of 28 solar analogs, 14 planet hosts, and 14 stars without known planets, with spectra at S/N ∼850 on average, in the metallicity range 0.14 < [Fe/H] < 0.36, and find the same abundance pattern for both samples of stars with and without planets. This result does not depend on either the planet mass, from 7 Earth masses to 17.4 Jupiter masses, or the orbital period of the planets, from 3 to 4300 days. In addition, we have derived the slope of the abundance ratios as a function of the condensation temperature for each star and again find similar distributions of the slopes for both stars with and without planets. In particular, the peaks of these two distributions are placed at a similar value but with the opposite sign to that expected from a possible signature of terrestrial planets. In particular, two of the planetary systems in this sample, each of them containing a super-Earth-like planet, show slope values very close to these peaks, which may suggest that these abundance patterns are not related to the presence of terrestrial planets.

  9. Terrestrial analogs, planetary geology, and the nature of geological reasoning

    Science.gov (United States)

    Baker, Victor R.

    2014-05-01

    Analogical reasoning is critical to planetary geology, but its role can be misconstrued by those unfamiliar with the practice of that science. The methodological importance of analogy to geology lies in the formulation of genetic hypotheses, an absolutely essential component of geological reasoning that was either ignored or denigrated by most 20th century philosophers of science, who took the theoretical/ experimental methodology of physics to be the sole model for all of scientific inquiry. Following the seminal 19th century work of Grove Karl Gilbert, an early pioneer of planetary geology, it has long been recognized that broad experience with and understanding of terrestrial geological phenomena provide geologists with their most effective resource for the invention of potentially fruitful, working hypotheses. The actions of (1) forming such hypotheses, (2) following their consequences, and (3) testing those consequences comprise integral parts of effective geological practice in regard to the understanding of planetary surfaces. Nevertheless, the logical terminology and philosophical bases for such practice will be unfamiliar to most planetary scientists, both geologists and nongeologists. The invention of geological hypotheses involves both inductive inferences of the type Gilbert termed “empiric classification” and abductive inferences of a logical form made famous by the 19th century American logician Charles Sanders Peirce. The testing and corroboration of geological hypotheses relies less on the correspondence logic of theoretical/ experimental sciences, like physics, and more on the logic of consistency, coherence, and consilience that characterizes the investigative and historical sciences of interpretation exemplified by geology.

  10. Large impacts around a solar-analog star in the era of terrestrial planet formation.

    Science.gov (United States)

    Meng, Huan Y A; Su, Kate Y L; Rieke, George H; Stevenson, David J; Plavchan, Peter; Rujopakarn, Wiphu; Lisse, Carey M; Poshyachinda, Saran; Reichart, Daniel E

    2014-08-29

    The final assembly of terrestrial planets occurs via massive collisions, which can launch copious clouds of dust that are warmed by the star and glow in the infrared. We report the real-time detection of a debris-producing impact in the terrestrial planet zone around a 35-million-year-old solar-analog star. We observed a substantial brightening of the debris disk at a wavelength of 3 to 5 micrometers, followed by a decay over a year, with quasi-periodic modulations of the disk flux. The behavior is consistent with the occurrence of a violent impact that produced vapor out of which a thick cloud of silicate spherules condensed that were then ground into dust by collisions. These results demonstrate how the time domain can become a new dimension for the study of terrestrial planet formation. Copyright © 2014, American Association for the Advancement of Science.

  11. Utah Marbles and Mars Blueberries: Comparitive Terrestrial Analogs for Hematite Concretions on Mars

    Science.gov (United States)

    Chan, M. A.; Beitler, B.; Parry, W. T.; Ormö, J.; Komatsu, G.

    2005-03-01

    Compelling comparisons show why Utah iron oxide-cemented "marbles" are a good analog for Mars hematite "blueberries". Terrestrial examples offer valuable models for interpreting the diagenetic history and importance of water on Mars.

  12. Lunar and Planetary Science XXXV: Mars: Remote Sensing and Terrestrial Analogs

    Science.gov (United States)

    2004-01-01

    The session "Mars: Remote Sensing and Terrestrial Analogs" included the following:Physical Meaning of the Hapke Parameter for Macroscopic Roughness: Experimental Determination for Planetary Regolith Surface Analogs and Numerical Approach; Near-Infrared Spectra of Martian Pyroxene Separates: First Results from Mars Spectroscopy Consortium; Anomalous Spectra of High-Ca Pyroxenes: Correlation Between Ir and M ssbauer Patterns; THEMIS-IR Emissivity Spectrum of a Large Dark Streak near Olympus Mons; Geomorphologic/Thermophysical Mapping of the Athabasca Region, Mars, Using THEMIS Infrared Imaging; Mars Thermal Inertia from THEMIS Data; Multispectral Analysis Methods for Mapping Aqueous Mineral Depostis in Proposed Paleolake Basins on Mars Using THEMIS Data; Joint Analysis of Mars Odyssey THEMIS Visible and Infrared Images: A Magic Airbrush for Qualitative and Quantitative Morphology; Analysis of Mars Thermal Emission Spectrometer Data Using Large Mineral Reference Libraries ; Negative Abundance : A Problem in Compositional Modeling of Hyperspectral Images; Mars-LAB: First Remote Sensing Data of Mineralogy Exposed at Small Mars-Analog Craters, Nevada Test Site; A Tool for the 2003 Rover Mini-TES: Downwelling Radiance Compensation Using Integrated Line-Sight Sky Measurements; Learning About Mars Geology Using Thermal Infrared Spectral Imaging: Orbiter and Rover Perspectives; Classifying Terrestrial Volcanic Alteration Processes and Defining Alteration Processes they Represent on Mars; Cemented Volcanic Soils, Martian Spectra and Implications for the Martian Climate; Palagonitic Mars: A Basalt Centric View of Surface Composition and Aqueous Alteration; Combining a Non Linear Unmixing Model and the Tetracorder Algorithm: Application to the ISM Dataset; Spectral Reflectance Properties of Some Basaltic Weathering Products; Morphometric LIDAR Analysis of Amboy Crater, California: Application to MOLA Analysis of Analog Features on Mars; Airborne Radar Study of Soil Moisture at

  13. Soil and terrestrial biology studies

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Soil and terrestrial biology studies focused on developing an understanding of the uptake of gaseous substances from the atmosphere by plants, biodegradation of oil, and the movement of Pu in the terrestrial ecosystems of the southeastern United States. Mathematical models were developed for SO 2 and tritium uptake from the atmosphere by plants; the uptake of tritium by soil microorganisms was measured; and the relationships among the Pu content of soil, plants, and animals of the Savannah River Plant area were studied. Preliminary results are reported for studies on the biodegradation of waste oil on soil surfaces

  14. Terrestrial Analogs for Clay Minerals at Yellowknife Bay, Gale Crater, Mars

    Science.gov (United States)

    Treiman, Allan H; Morris, Richard V.; Bristow, Thomas; Ming, Douglas W.; Achillies, Cherie; Bish, David L.; Blake, David; Vaniman, David; Chipera, Steve

    2013-01-01

    Sediments of the Sheepbed unit, Gale Crater, were analyzed by the CheMin X-ray diffraction instrument on the Curiosity Rover. The sediments consist of typical basalt minerals (Fe-forsterite, augite, pigeonite, plagioclase), as well as Fe oxide/hydroxides, Fesulfides, amorphous material, and a phyllosilicate. The phyllosilicate has a broad 001 peak at approx 1.0 nm, consistent with a poorly ordered smectite. However, in the absence of diagnostic tests possible on Earth, its identity is not clear. The position of the 06L diffraction band is generally used to distinguish dioctahedral from trioctahedral smectite, but it is beyond CheMin's range of 2 Theta. The measured position of the 02L diffraction band (approx 22.5deg 2 Theta by CheMin), implies that the smectite is trioctahedral. The exact position and shape of the 02L band is determined by the cations in the 'M' sites of the smectite; to constrain those cations, we sought analogs among terrestrial smectites, emphasizing those developed from basaltic precursors. A potential analog for the Sheepbed smectite is 'griffithite,' a variety of trioctahedral smectite in altered basalt of the Topanga formation, Griffith Park, Los Angeles. 'Griffithite' has an 02L diffraction band that is close in position and shape to that of the Sheepbed smectite, although 'griffithite' has a very sharp 001 peak, indicating a high degree of layer ordering not seen in the Sheepbed smectite. A typical chemical formula for 'griffithite,' determined by electron microprobe, is (Ca0.59 Na0.03) (Mg4.28 Fe1.83) (Si6.64 Al1.36) O20 (OH)4, normalized to Si+Al=8. This formula is consistent with a fully trioctahedral Fe-Mg smectite with Ca and Na as interlayer cations. In the Topanga basalt, four types of 'griffithite' are present: fine-grained, filling cracks and vesicles; coarse-grained, filling vesicles; coarse-grained, replacing olivine phenocrysts; and coarse-grained, replacing glassy mesostasis. The fine-grained 'griffithite' formed first, and

  15. Low Biotoxicity of Mars Analog Soils Suggests that the Surface of Mars May be Habitable for Terrestrial Microorganisms

    Science.gov (United States)

    Schuerger, A. C.; Ming, Douglas W.; Golden, D. C.

    2012-01-01

    Recent studies on the interactive effects of hypobaria, low temperatures, and CO2-enriched anoxic atmospheres on the growth of 37 species of mesophilic bacteria identified 14 potential biocidal agents that might affect microbial survival and growth on the martian surface. Biocidal or inhibitory factors include (not in priority): (1) solar UV irradiation, (2) low pressure, (3) extreme desiccating conditions, (4) extreme diurnal temperature fluctuations, (5) solar particle events, (6) galactic cosmic rays, (7) UV-glow discharge from blowing dust, (8) solar UV-induced volatile oxidants [e.g., O2(-), O(-), H2O2, O3], (9) globally distributed oxidizing soils, (10) extremely high salts levels [e.g., MgCl2, NaCl, FeSO4, and MgSO4] in surficial soils at some sites on Mars, (11) high concentrations of heavy metals in martian soils, (12) likely acidic conditions in martian fines, (13) high CO2 concentrations in the global atmosphere, and (14) perchlorate-rich soils. Despite these extreme conditions several studies have demonstrated that dormant spores or vegetative cells of terrestrial microorganisms can survive simulated martian conditions as long as they are protected from UV irradiation. What has not been explored in depth are the effects of potential biotoxic geochemical components of the martian regolith on the survival and growth of microorganisms. The primary objectives of the research included: (1) prepare and characterize Mars analog soils amended with potential biotoxic levels of sulfates, salts, acidifying minerals, etc.; and (2) use the simulants to conduct biotoxicity assays to determine if terrestrial microorganisms from spacecraft can survive direct exposure to the analog soils.

  16. The Geology of Inferno Chasm, Idaho: a Terrestrial Analog for Lunar Rilles?

    Science.gov (United States)

    Garry, William B.; Hughes, Scott S.; Kobs Nawotniak, Shannon E.; Neish, Catherine D.; Haberle, Christopher W.; Heldmann, Jennifer L.; Lim, Darlene S. S.

    2014-01-01

    Lunar sinuous rilles are thought to have formed by thermal erosion, mechanical erosion, construction, or a combination of these processes via emplacement by lava tubes or lava channels. The investigation of Hadley Rille by Apollo 15 provided the first field observations of a rille, but remote sensing observations remain our primary method for studying these features. Terrestrial volcanic features with similar morphologies to lunar rilles can provide insight into their formation on the Moon.

  17. Characterization of terrestrial hydrothermal alteration products with Mars analog instrumentation: Implications for current and future rover investigations

    Science.gov (United States)

    Black, Sarah R.; Hynek, Brian M.

    2018-06-01

    Interpretation of Martian geology relies heavily on our understanding of terrestrial analog deposits and our ability to obtain comprehensive and accurate mineralogical compositions. Many previous studies of terrestrial hydrothermal deposits relied on limited datasets and/or did not use instruments analogous to those deployed on Mars. We analyzed 100 hydrothermally altered basalts from Costa Rica, Nicaragua, and Iceland with Mars analog Visible to Short Wave Infrared (VSWIR) spectroscopy, X-ray Diffraction (XRD), and Raman laser spectrometry. Alteration mineralogy consisted of amorphous and crystalline SiO2 (cristobalite, tridymite, quartz), Ca/Al/Fe/Mg-sulfates (gypsum, anhydrite, alunite, jarosite, hexahydrite, alunogen), Fe-, Ti-, and Mg-oxides/hydroxides (hematite, goethite, anatase/brookite, brucite), elemental sulfur, and phyllosilicates (montmorillonite, kaolinite). Results indicate VSWIR is best suited for identification of X-ray amorphous materials such as hydrated SiO2 and phyllosilicates, while XRD is best utilized for highly ordered crystalline materials such as sulfates, crystalline SiO2 polymorphs, elemental sulfur, and Mg-hydroxides identification. Surprisingly, XRD had the lowest identification rates for Fe-oxides/hydroxides (42% compared to 61% and 75% for VNIR and Raman, respectively), and nearly equal identification rates as VSWIR for kaolinite (76% for VSWIR, 71% for XRD). Identification of phyllosilicates in XRD, while possible, is not as effective as VSWIR without extensive sample preparation. Our observed identification rates may be attributed to the relative abundance of materials-Fe-oxides/hydroxides being present as surface coatings, the presence of large amounts of kaolinite in some samples, and an increased particle size for kaolinite relative to other clays. Elemental sulfur and Fe- and Ti-oxides/hydroxides were more readily identified with Raman. With NASA's current focus on habitability, hydrothermally altered areas-which we know to

  18. Terrestrial rock glaciers: a potential analog for Martian lobate flow features (LFF)

    Science.gov (United States)

    Sinha, Rishitosh K.; Vijayan, Sivaprahasam; Bharti, Rajiv R.

    2016-05-01

    Rock glaciers, regarded as cryospheric ice/water resource in the terrestrial-glacial systems based on their tongue/lobate-shaped flow characteristic and subsurface investigation using ground-penetrating radar. We examined the subsurface, geomorphology, climate-sensitivity and thermophysical properties of a Lobate Flow Feature (LFF) on Mars (30°-60° N and S hemispheres) to compare/assess the potentials of rock glaciers as an analog in suggesting LFFs to be a source of subsurface ice/water. LFFs are generally observed at the foot of impact craters' wall. HiRISE/CTX imageries from MRO spacecraft were used for geomorphological investigation of LFF using ArcMap-10.0 and subsurface investigation was carried out using data from MRO-SHARAD (shallow radar) after integrating with SiesWare-8.0. ENVI-5.0 was used to retrieve thermophysical properties of LFF from nighttime datasets (12.57 μm) acquired by THEMIS instrument-onboard the Mars Odyssey spacecraft and derive LFFs morphometry from MOLA altimeter point tracks onboard MGS spacecraft. Integrating crater chronology tool (Craterstats) with Arc Map, we have derived the formation age of LFF. Our investigation and comparison of LFF to rock glaciers revealed: (1) LFFs have preserved ice at depth 50m as revealed from SHARAD radargram and top-layer composed of rocky-debris material with thermal inertia ( 300-350 Jm-2 K-1s-1/2). (2) LFF formation age ( 10-100 Ma) corresponds to moderate scale debris covered glaciation of a shorter-span suggesting high sensitivity to obliquity-driven climatic shifts. (3) Presence of polygon cracks and high linear-arcuate furrow-and-ridges on the surface indicates presence of buried ice. This work is a significant step towards suggesting LFF to be a potential source of present-day stored ice/water on Mars.

  19. SAR mapping of Burfellshraun: A terrestrial analog for recent volcanism on Mars

    DEFF Research Database (Denmark)

    Haack, Henning; Rossi, Matti; Dall, Jørgen

    2006-01-01

    between 10 and 100 Myr. Parts of the lava flows show smooth kilometer-sized plates that appear to have rafted on the moving lava flow. We have found a terrestrial analogue with similar features, the Burfellshraun lava flow in Northern Iceland. This is the only known lava flow on Earth where kilometer......-sized rafting plates are observed and constitute the dominating feature. Using a combination of airborne remote sensing data and field observations we have studied the emplacement and physical properties of the flow. On the basis of our observations we have reconstructed the sequence of events that led...

  20. Terrestrial analogs to lunar sinuous rilles - Kauhako Crater and channel, Kalaupapa, Molokai, and other Hawaiian lava conduit systems

    International Nuclear Information System (INIS)

    Coombs, C.R.; Hawke, B.R.; Wilson, L.

    1990-01-01

    Two source vents, one explosive and one effusive erupted to form a cinder cone and low lava shield that together compose the Kalaupapa peninsula of Molokai, Hawaii, A 50-100-m-wide channel/tube system extends 2.3 km northward from kauhako crater in the center of the shield. Based on modeling, a volume of up to about 0.2 cu km of lava erupted at a rate of 260 cu m/sec to flow through the Kauhako conduit system in one of the last eruptive episodes on the peninsula. Channel downcutting by thermal erosion occurred at a rate of about 10 micron/sec to help form the 30-m-deep conduit. Two smaller, secondary tube systems formed east of the main lava channel/tube. Several other lava conduit systems on the islands of Oahu and Hawaii were also compared to the Kauhako and lunar sinuous rille systems. These other lava conduits include Whittington, Kupaianaha, and Mauna Ulu lava tubes. Morphologically, the Hawaiian tube systems studied are very similar to lunar sinuous rilles in that they have deep head craters, sinuous channels, and gentle slopes. Thermal erosion is postulated to be an important factor in the formation of these terrestrial channel systems and by analogy is inferred to be an important process involved in the formation of lunar sinuous rilles. 28 refs

  1. Ethnopharmacological Studies of Tribulus Terrestris (Linn). in ...

    African Journals Online (AJOL)

    Synergism and antagonism impact of different plant metabolites present in crude fruit extract of Tribulus terrestris 'the herbal Viagra' have been studied. Variability in plant composition, biomass and metabolites concentration in different modules was significantly contributed by spatial factor. However the edhaphic ...

  2. Biophysical and lipofection studies of DOTAP analogs.

    Science.gov (United States)

    Regelin, A E; Fankhaenel, S; Gürtesch, L; Prinz, C; von Kiedrowski, G; Massing, U

    2000-03-15

    In order to investigate the relationship between lipid structure and liposome-mediated gene transfer, we have studied biophysical parameters and transfection properties of monocationic DOTAP analogs, systematically modified in their non-polar hydrocarbon chains. Stability, size and (by means of anisotropy profiles) membrane fluidity of liposomes and lipoplexes were determined, and lipofection efficiency was tested in a luciferase reporter gene assay. DOTAP analogs were used as single components or combined with a helper lipid, either DOPE or cholesterol. Stability of liposomes was a precondition for formation of temporarily stable lipoplexes. Addition of DOPE or cholesterol improved liposome and lipoplex stability. Transfection efficiencies of lipoplexes based on pure DOTAP analogs could be correlated with stability data and membrane fluidity at transfection temperature. Inclusion of DOPE led to rather uniform transfection and anisotropy profiles, corresponding to lipoplex stability. Cholesterol-containing lipoplexes were generally stable, showing high transfection efficiency at low relative fluidity. Our results demonstrate that the efficiency of gene transfer mediated by monocationic lipids is greatly influenced by lipoplex biophysics due to lipid composition. The measurement of fluorescence anisotropy is an appropriate method to characterize membrane fluidity within a defined system of liposomes or lipoplexes and may be helpful to elucidate structure-activity relationships.

  3. Sulfate- and Sulfur-Reducing Bacteria as Terrestrial Analogs for Microbial Life on Jupiter's Satellite Io

    Science.gov (United States)

    Pikuta, Elena V.; Hoover, Richard B.; Six, N. Frank (Technical Monitor)

    2001-01-01

    Observations from the Voyager and Galileo spacecraft have revealed Jupiter's moon Io to be the most volcanically active body of our Solar System. The Galileo Near Infrared Imaging Spectrometer (NIMS) detected extensive deposits of sulfur compounds, elemental sulfur and SO2 frost on the surface of Io. There are extreme temperature variations on Io's surface, ranging from -130 C to over 2000 C at the Pillan Patera volcanic vent. The active volcanoes, fumaroles, calderas, and lava lakes and vast sulfur deposits on this frozen moon indicate that analogs of sulfur- and sulfate-reducing bacteria might inhabit Io. Hence Io may have great significance to Astrobiology. Earth's life forms that depend on sulfur respiration are members of two domains: Bacteria and Archaea. Two basic links of the biogeochemical sulfur cycle of Earth have been studied: 1) the sulfur oxidizing process (occurring at aerobic conditions) and 2) the process of sulfur-reduction to hydrogen sulfide (anaerobic conditions). Sulfate-reducing bacteria (StRB) and sulfur-reducing bacteria (SrRB) are responsible for anaerobic reducing processes. At the present time the systematics of StRB include over 112 species distributed into 35 genera of Bacteria and Archaea. Moderately thermophilic and mesophilic SrRB belong to the Bacteria. The hyperthermophilic SrRB predominately belong to the domain Archaea and are included in the genera: Pyrodictium, Thermoproteus, Pyrobaculum, Thermophilum, Desulfurococcus, and Thermodiscus. The StRB and SrRB use a wide spectrum of substrates as electron donors for lithotrophic and heterotrophic type nutrition. The electron acceptors for the StRB include: sulfate, thiosulfate, sulfite, sulfur, arsenate, dithionite, tetrathionate, sulfur monoxide, iron, nitrite, selenite, fumarate, oxygen, carbon dioxide, and chlorine-containing phenol compounds. The Sulfate- and Sulfur-reducing bacteria are widely distributed in anaerobic ecosystems, including extreme environments like hot springs

  4. Natural Analog Studies at Pena Blanca, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    A.M. Simmons

    2005-07-11

    The significance of the Pena Blanca uranium deposits in the State of Chihuahua, Mexico as potential natural analogs for a nuclear waste repository in unsaturated welded tuff was first recognized in the 1980s. In the 1970s, the Pena Blanca region was a major target of uranium exploration and exploitation by the Mexican government. Since then the Nopal I uranium deposit has been studied extensively by researchers in the U.S., Mexico, and Europe. The Nopal I deposit represents an environment similar to that of the proposed high-level radioactive waste repository at Yucca Mountain in many ways. Both are located in semi-arid regions. Both are located in Tertiary rhyolitic tuffs overlying carbonate rocks that have been subjected to basin and range-style tectonic deformation. Both are located in a chemically oxidizing, unsaturated zone 200 m or more above the water table. The alteration of uraninite to secondary minerals at Nopal I may be similar to the alteration of uranium fuel rods in this type of setting. Investigations at Nopal I and in the surrounding Sierra Pena Blanca have included detailed outcrop mapping, hydrologic and isotopic studies of flow and transport, studies of mineral alteration, modeling, and performance assessment.

  5. Natural Analog Studies at Pena Blanca, Mexico

    International Nuclear Information System (INIS)

    A.M. Simmons

    2005-01-01

    The significance of the Pena Blanca uranium deposits in the State of Chihuahua, Mexico as potential natural analogs for a nuclear waste repository in unsaturated welded tuff was first recognized in the 1980s. In the 1970s, the Pena Blanca region was a major target of uranium exploration and exploitation by the Mexican government. Since then the Nopal I uranium deposit has been studied extensively by researchers in the U.S., Mexico, and Europe. The Nopal I deposit represents an environment similar to that of the proposed high-level radioactive waste repository at Yucca Mountain in many ways. Both are located in semi-arid regions. Both are located in Tertiary rhyolitic tuffs overlying carbonate rocks that have been subjected to basin and range-style tectonic deformation. Both are located in a chemically oxidizing, unsaturated zone 200 m or more above the water table. The alteration of uraninite to secondary minerals at Nopal I may be similar to the alteration of uranium fuel rods in this type of setting. Investigations at Nopal I and in the surrounding Sierra Pena Blanca have included detailed outcrop mapping, hydrologic and isotopic studies of flow and transport, studies of mineral alteration, modeling, and performance assessment

  6. Simulations of the Viking Gas Exchange Experiment using palagonite and Fe-rich montmorillonite as terrestrial analogs: implications for the surface composition of Mars.

    Science.gov (United States)

    Quinn, R; Orenberg, J

    1993-10-01

    Simulations of the Gas Exchange Experiment (GEX), one of the Viking Lander Biology Experiments, were run using palagonite and Fe-rich montmorillonite as terrestrial analogs of the Martian soil. These terrestrial analogs were exposed to a nutrient solution of the same composition as that of the Viking Landers under humid (no contact with nutrient) and wet (intimate contact) conditions. The headspace gases in the GEX sample cell were sampled and then analyzed by gas chromatography under both humid and wet conditions. Five gases were monitored: CO2, N2, O2, Ar, and Kr. It was determined that in order to simulate the CO2 gas changes of the Viking GEX experiment, the mixture of soil analog mineral plus nutrient medium must be slightly (pH = 7.4) to moderately basic (pH = 8.7). This conclusion suggests constraints upon the composition of terrestrial analogs to the Mars soil; acidic components may be present, but the overall mixture must be basic in order to simulate the Viking GEX results.

  7. Some Studies of Terrestrial Impact Cratering Rate

    Directory of Open Access Journals (Sweden)

    Jetsu L.

    2011-06-01

    Full Text Available In 1984, a 28.4 Myr periodicity was detected in the ages of terrestrial impact craters and a 26 Myr periodicity in the epochs of mass extinctions of species. Periodic comet showers from the Oort cloud seemed to cause catastrophic events linked to mass extinctions of species. Our first study revealed that the only significant detected periodicity is the “human signal” caused by the rounding of these data into integer numbers. The second study confirmed that the original 28.4 Myr periodicity detection was not significant. The third study revealed that the quality and the quantity of the currently available data would allow detection of real periodicity only if all impacts have been periodic, which cannot be the case. The detection of a periodic signal, if present, requires that more craters should be discovered and the accuracy of age estimates improved. If we sometimes will be able to find the difference between the craters caused by asteroid and comet impacts, the aperiodic component could be removed. The lunar impact craters may eventually provide the required supplementary data.

  8. Analytical, Experimental, and Modelling Studies of Lunar and Terrestrial Rocks

    Science.gov (United States)

    Haskin, Larry A.

    1997-01-01

    The goal of our research has been to understand the paths and the processes of planetary evolution that produced planetary surface materials as we find them. Most of our work has been on lunar materials and processes. We have done studies that obtain geological knowledge from detailed examination of regolith materials and we have reported implications for future sample-collecting and on-surface robotic sensing missions. Our approach has been to study a suite of materials that we have chosen in order to answer specific geologic questions. We continue this work under NAG5-4172. The foundation of our work has been the study of materials with precise chemical and petrographic analyses, emphasizing analysis for trace chemical elements. We have used quantitative models as tests to account for the chemical compositions and mineralogical properties of the materials in terms of regolith processes and igneous processes. We have done experiments as needed to provide values for geochemical parameters used in the models. Our models take explicitly into account the physical as well as the chemical processes that produced or modified the materials. Our approach to planetary geoscience owes much to our experience in terrestrial geoscience, where samples can be collected in field context and sampling sites revisited if necessary. Through studies of terrestrial analog materials, we have tested our ideas about the origins of lunar materials. We have been mainly concerned with the materials of the lunar highland regolith, their properties, their modes of origin, their provenance, and how to extrapolate from their characteristics to learn about the origin and evolution of the Moon's early igneous crust. From this work a modified model for the Moon's structure and evolution is emerging, one of globally asymmetric differentiation of the crust and mantle to produce a crust consisting mainly of ferroan and magnesian igneous rocks containing on average 70-80% plagioclase, with a large

  9. STUDY OF ANTIBACTERIAL EFFECT OF TRIBULUS TERRESTRIS EXTRACT.

    OpenAIRE

    Mohanad H. Hussein.

    2018-01-01

    This study was designed to evaluated antimicrobial activity of Tribulus terrestris aqueous extract against some pathogenic microorganisms. So that, the aqueous extract of Tribulus terrestris was screened for its anti-microbial activity using the plate agar diffusion method. It was tested against four bacteria species; two Gram-positive bacteria (Bacillus subtilis, and Staphylococcus aureus) and two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). The susceptibility of the...

  10. Coastal niches for terrestrial predators: a stable isotope study

    Energy Technology Data Exchange (ETDEWEB)

    Mellbrand, K.; Hamback, P.A., E-mail: peter.hamback@botan.su.se [Stockholm Univ., Dept. of Botany, Stockholm (Sweden)

    2010-12-15

    The purpose of this study was to identify the use of marine versus terrestrial food items by terrestrial arthropod predators on Baltic Sea shores. The inflow of marine nutrients in the area consists mainly of marine algal detritus and emerging aquatic insects (e.g., chironomids). Diets of coastal arthropods were examined using carbon and nitrogen stable isotope analysis in a two source mixing model. The results suggest that spiders are the terrestrial predators mainly utilizing nutrients and energy of marine origin on Baltic Sea shores, whereas insect predators such as beetles and heteropterans mainly utilize nutrients and energy derived from terrestrial sources, possibly owing to differences in hunting behaviour. That spiders are the predators which benefit the most from the marine inflow suggest that eventual effects of marine subsidies for the coastal ecosystem as a whole are likely mediated by spiders. (author)

  11. Coastal niches for terrestrial predators: a stable isotope study

    International Nuclear Information System (INIS)

    Mellbrand, K.; Hamback, P.A.

    2010-01-01

    The purpose of this study was to identify the use of marine versus terrestrial food items by terrestrial arthropod predators on Baltic Sea shores. The inflow of marine nutrients in the area consists mainly of marine algal detritus and emerging aquatic insects (e.g., chironomids). Diets of coastal arthropods were examined using carbon and nitrogen stable isotope analysis in a two source mixing model. The results suggest that spiders are the terrestrial predators mainly utilizing nutrients and energy of marine origin on Baltic Sea shores, whereas insect predators such as beetles and heteropterans mainly utilize nutrients and energy derived from terrestrial sources, possibly owing to differences in hunting behaviour. That spiders are the predators which benefit the most from the marine inflow suggest that eventual effects of marine subsidies for the coastal ecosystem as a whole are likely mediated by spiders. (author)

  12. The Use of Terrestrial Analogs in Preparing for Planetary Surface Exploration: Sampling and Radioisotopic Dating of Impactites and Deployment of In Situ Analytical Technologies

    Science.gov (United States)

    Young, Kelsey

    Impact cratering has played a crucial role in the surface development of the inner planets. Constraining the timing of this bombardment history is important in understanding the origins of life and our planet's evolution. Plate tectonics, active volcanism, and vegetation hinder the preservation and identification of existing impact craters on Earth. Providing age constraints on these elusive structures will provide a deeper understanding of our planet's development. To do this, (U-Th)/He thermochronology and in situ 40 Ar/39Ar laser microprobe geochronology are used to provide ages for the Haughton and Mistastin Lake impact structures, both located in northern Canada. While terrestrial impact structures provide accessible laboratories for deciphering Earth's impact history, the ultimate goal for understanding the history of the reachable inner Solar System is to acquire robust, quantitative age constraints for the large lunar impact basins. The oldest of these is the South Pole-Aitken basin (SPA), located on the lunar farside. While it is known that this basin is stratigraphically the oldest on the Moon, its absolute age has yet to be determined. Several reports released in the last decade have highlighted sampling and dating SPA as a top priority for inner Solar System exploration. This is no easy task as the SPA structure has been modified by four billion subsequent years of impact events. Informed by studies at Mistastin---which has target lithologies analogous to those at SPA---sampling strategies are discussed that are designed to optimize the probability of a high science return with regard to robust geochronology of the SPA basin. Planetary surface missions, like one designed to explore and sample SPA, require the integration of engineering constraints with scientific goals and traverse planning. The inclusion of in situ geochemical technology, such as the handheld X-ray fluorescence spectrometer (hXRF), into these missions will provide human crews with the

  13. Analog to digital workflow improvement: a quantitative study.

    Science.gov (United States)

    Wideman, Catherine; Gallet, Jacqueline

    2006-01-01

    This study tracked a radiology department's conversion from utilization of a Kodak Amber analog system to a Kodak DirectView DR 5100 digital system. Through the use of ProModel Optimization Suite, a workflow simulation software package, significant quantitative information was derived from workflow process data measured before and after the change to a digital system. Once the digital room was fully operational and the radiology staff comfortable with the new system, average patient examination time was reduced from 9.24 to 5.28 min, indicating that a higher patient throughput could be achieved. Compared to the analog system, chest examination time for modality specific activities was reduced by 43%. The percentage of repeat examinations experienced with the digital system also decreased to 8% vs. the level of 9.5% experienced with the analog system. The study indicated that it is possible to quantitatively study clinical workflow and productivity by using commercially available software.

  14. Analogous study of English linguistic knowledge between ...

    African Journals Online (AJOL)

    Marketing strategy is the effective deployment and coordination of marketing resources to achieved the business enterprise objectives within a particular product market. However, banks often have problem of formulating good marketing strategy plan that will enhance the bank general performance. The study examine ...

  15. Assessing antiquity and turnover of terrestrial ecosystems in eastern North America using fossil pollen data: A preliminary study

    International Nuclear Information System (INIS)

    Liu Yao; Jackson, Stephen T; Brewer, Simon; Williams, John W

    2010-01-01

    We explored formal approaches to identifying and interpreting the antiquity and turnover of terrestrial ecosystems in eastern North America using pollen records. Preliminary results of cluster analyses, receiver-operating characteristic (ROC) analyses, and likelihood estimation of ecosystem analog in a simple Bayesian model allow assessment of modern ecosystem antiquities and past ecosystem turnovers. Approaches discussed in this study thus provide a vehicle for further studies.

  16. [Feasibility study for whole plant medicinal use of Tribulus terrestris].

    Science.gov (United States)

    Yang, Li; Wang, Chunyu; Han, Meiw; Yang, Limin

    2009-09-01

    The content differences of leaf, plant and fruit of Tribulus terrestris was compared to study the feasibility of whole plant medicinal use. The samples were collected in three typical habitats and six different production areas of T. terrestris. The main medicinal ingredients saponins and flavonoids were determined in root, stem, leaf and fruit during the harvest time. The two ingredients were abounded in leaf and more than 2.61 times as in other parts of the plant. The results showed that there were no differences between the whole plant and the fruit. It should pay more attentions on the collection, preservation and utilization of the leaf of T. terrestris in the harvesting and processing stage. The whole plant for medical use was feasibility based on the content of the ingredients.

  17. Intra-terrestrial Biosorption of Radionuclides and Analogous Trace Elements. Microbial Interference with the 'Water/Rock Interface'

    International Nuclear Information System (INIS)

    Anderson, Craig

    2005-12-01

    The Swedish nuclear fuel management company (SKB) has instigated final site investigations for a deep subsurface high level nuclear waste (HLW) repository in granitic rock. This facility will be situated 500 meters below ground level and will isolate the HLW from the environment using an engineered multi-barrier system with a supposed design life of 10 5 to 10 6 years. As microbial life is ubiquitous in intra-terrestrial environments, assessing the subsurface geochemical and geomicrobial influences is critical for predicting the safety and longevity of HLW storage. In the possible event of repository failure, the transport of radionuclides through water conducting rock fractures is the predominant concern but radionuclide migration can be retarded by abiotic and biotic sorption processes. In this study biofilms were grown under in situ pressures and conditions using groundwater sourced from boreholes 296 m to 450m below sea level at the Aespoe hard rock laboratory (IM) in Sweden. Purpose built biofilm reactors were installed and left to develop microbial communities for up to one year. The community genera were then analysed genetically along with the population characteristics. Scintillation, NaI Y-detection, ICP-MS and autoradiography were used to investigate the ability of these biofilms to absorb trace metals from fracture fluids and synthetic groundwater containing Co, Pm, Np, Am, Th, U and Mo. The concentrations of PGE (platinum group elements) and REE (rare earth elements) were also measured by ICP-MS for experiments conducted in aerobic conditions. Results indicate that aerobic biofilms grown in near neutral pH conditions, with low pressure (1 bar) and oxygen (<1.5 mg/l; Eh <190 mV), can rapidly attenuate metals to over 1000-fold higher than the levels within the groundwater. In anaerobic conditions biofilms in 1.5 % salt and near neutral pH tend to favour the adsorption of the 3+ valence state (Am, Pm) over other radionuclides such as Co, Th, Np, U and Mo

  18. 76 FR 50274 - Terrestrial Environmental Studies for Nuclear Power Stations

    Science.gov (United States)

    2011-08-12

    ... Draft Regulatory Guides in the ``Regulatory Guides'' collection of the NRC's Library at http://www.nrc... Stations AGENCY: Nuclear Regulatory Commission. ACTION: Draft regulatory guide; request for comment... draft regulatory guide (DG), DG-4016, ``Terrestrial Environmental Studies for Nuclear Power Stations...

  19. Acetyl analogs of combretastatin A-4: synthesis and biological studies.

    Science.gov (United States)

    Babu, Balaji; Lee, Megan; Lee, Lauren; Strobel, Raymond; Brockway, Olivia; Nickols, Alexis; Sjoholm, Robert; Tzou, Samuel; Chavda, Sameer; Desta, Dereje; Fraley, Gregory; Siegfried, Adam; Pennington, William; Hartley, Rachel M; Westbrook, Cara; Mooberry, Susan L; Kiakos, Konstantinos; Hartley, John A; Lee, Moses

    2011-04-01

    The combretastatins have received significant attention because of their simple chemical structures, excellent antitumor efficacy and novel antivascular mechanisms of action. Herein, we report the synthesis of 20 novel acetyl analogs of CA-4 (1), synthesized from 3,4,5-trimethoxyphenylacetone that comprises the A ring of CA-4 with different aromatic aldehydes as the B ring. Molecular modeling studies indicate that these new compounds possess a 'twisted' conformation similar to CA-4. The new analogs effectively inhibit the growth of human and murine cancer cells. The most potent compounds 6k, 6s and 6t, have IC(50) values in the sub-μM range. Analog 6t has an IC(50) of 182 nM in MDA-MB-435 cells and has advantages over earlier analogs due to its enhanced water solubility (456 μM). This compound initiates microtubule depolymerization with an EC(50) value of 1.8 μM in A-10 cells. In a murine L1210 syngeneic tumor model 6t had antitumor activity and no apparent toxicity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Application of natural analog studies to exploration for ore deposits

    International Nuclear Information System (INIS)

    Gustafson, D.L.

    1995-01-01

    Natural analogs are viewed as similarities in nature and are routinely utilized by exploration geologists in their search for economic mineral deposits. Ore deposit modeling is undertaken by geologists to direct their exploration activities toward favorable geologic environments and, therefore, successful programs. Two types of modeling are presented: (i) empirical model development based on the study of known ore deposit characteristics, and (ii) concept model development based on theoretical considerations and field observations that suggest a new deposit type, not known to exist in nature, may exist and justifies an exploration program. Key elements that are important in empirical model development are described, and examples of successful applications of these natural analogs to exploration are presented. A classical example of successful concept model development, the discovery of the McLaughlin gold mine in California, is presented. The utilization of natural analogs is an important facet of mineral exploration. Natural analogs guide explorationists in their search for new discoveries, increase the probability of success, and may decrease overall exploration expenditure

  1. Terrestrial ecology. Comprehensive study of the grassland biome

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Terrestrial ecology and grassland biome studies are designed to characterize the biota of the Hanford Reservation, elucidate seasonal dynamics of plant productivity, decomposition and mineral behavior patterns of important plant communities, and, to study the response of these communities to important natural environmental stresses, such as weather, wildfire and man-induced alterations of communities (influenced by grazing cattle and severe mechanical disturbance of the soil, such as affected by plowing or burial of waste materials or construction activities). A detailed account of the important findings of a 5-yr study is currently being prepared by the terrestrial ecology section staff for publication as a contribution to the International Biological Program Grassland Biome project

  2. Satellite-Based Thermophysical Analysis of Volcaniclastic Deposits: A Terrestrial Analog for Mantled Lava Flows on Mars

    Directory of Open Access Journals (Sweden)

    Mark A. Price

    2016-02-01

    Full Text Available Orbital thermal infrared (TIR remote sensing is an important tool for characterizing geologic surfaces on Earth and Mars. However, deposition of material from volcanic or eolian activity results in bedrock surfaces becoming significantly mantled over time, hindering the accuracy of TIR compositional analysis. Moreover, interplay between particle size, albedo, composition and surface roughness add complexity to these interpretations. Apparent Thermal Inertia (ATI is the measure of the resistance to temperature change and has been used to determine parameters such as grain/block size, density/mantling, and the presence of subsurface soil moisture/ice. Our objective is to document the quantitative relationship between ATI derived from orbital visible/near infrared (VNIR and thermal infrared (TIR data and tephra fall mantling of the Mono Craters and Domes (MCD in California, which were chosen as an analog for partially mantled flows observed at Arsia Mons volcano on Mars. The ATI data were created from two images collected ~12 h apart by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER instrument. The results were validated with a quantitative framework developed using fieldwork that was conducted at 13 pre-chosen sites. These sites ranged in grain size from ash-sized to meter-scale blocks and were all rhyolitic in composition. Block size and mantling were directly correlated with ATI. Areas with ATI under 2.3 × 10−2 were well-mantled with average grain size below 4 cm; whereas values greater than 3.0 × 10−2 corresponded to mantle-free surfaces. Correlation was less accurate where checkerboard-style mixing between mantled and non-mantled surfaces occurred below the pixel scale as well as in locations where strong shadowing occurred. However, the results validate that the approach is viable for a large majority of mantled surfaces on Earth and Mars. This is relevant for determining the volcanic history of Mars, for

  3. Reasoning by analogy: rational foundation of natural analogue studies

    International Nuclear Information System (INIS)

    Petit, J.-C.

    1992-01-01

    Long-term extrapolations concerning the safety of a nuclear waste repository cannot be satisfactorily made on the sole basis of short-term laboratory investigations. Most nuclear countries have hence developed an approach relying on the following research directions: 1. laboratory experiments; 2. in situ testing; 3. modeling; and 4. natural analogues, which are the only means by which very slow mechanisms can be identified and by which long-term predictions of models can be tested for pertinence (if not truly validated). Although the field of natural analogues has grown very rapidly in recent years, receiving support from varied specialists and institutions involved in radioactive waste disposal, there is not yet a full consensus on their actual usefulness. More problematic is the criticism sometimes made that analogical reasoning is not ''true science'' and that information retrieved from the study of natural analogues will always remain questionable. The present paper gives some clues about the exact status of reasoning by analogy, compared to more ''scientific'' ways of deriving information from investigated systems. It is not a thorough discussion of this very complex, and by far too philosophical issue but we hope, at least, to present to readers of papers devoted to natural analogue studies arguments showing that this approach has some sound foundation. (author)

  4. Hydrogen (H) Isotope Composition of Type II Kerogen Extracted by Pyrolysis-GC-MS-IRMS: Terrestrial Shale Deposits as Martian Analogs

    Science.gov (United States)

    Socki, Richard A.; Pernia, Denet; Evans, Michael; Fu, Qi; Bissada, Kadry K.; Curiale, Joseph A.; Niles, Paul B.

    2014-01-01

    water and/or acid during the kerogen isolation process. Either of these interpretations will prove useful when deciphering H isotope data derived from kerogen analyses. Understanding the role that these H-bearing compounds play in terrestrial shale paleo-environmental reconstruction may also prove useful as analogs for understanding the interactions of water and potential kerogen/organic compounds on the planet Mars.

  5. Earth analog image digitization of field, aerial, and lab experiment studies for Planetary Data System archiving.

    Science.gov (United States)

    Williams, D. A.; Nelson, D. M.

    2017-12-01

    A portion of the earth analog image archive at the Ronald Greeley Center for Planetary Studies (RGCPS)-the NASA Regional Planetary Information Facility at Arizona State University-is being digitized and will be added to the Planetary Data System (PDS) for public use. This will be a first addition of terrestrial data to the PDS specifically for comparative planetology studies. Digitization is separated into four tasks. First is the scanning of aerial photographs of volcanic and aeolian structures and flows. The second task is to scan field site images taken from ground and low-altitude aircraft of volcanic structures, lava flows, lava tubes, dunes, and wind streaks. The third image set to be scanned includes photographs of lab experiments from the NASA Planetary Aeolian Laboratory wind tunnels, vortex generator, and of wax models. Finally, rare NASA documents are being scanned and formatted as PDF files. Thousands of images are to be scanned for this project. Archiving of the data will follow the PDS4 standard, where the entire project is classified as a single bundle, with individual subjects (i.e., the Amboy Crater volcanic structure in the Mojave Desert of California) as collections. Within the collections, each image is considered a product, with a unique ID and associated XML document. Documents describing the image data, including the subject and context, will be included with each collection. Once complete, the data will be hosted by a PDS data node and available for public search and download. As one of the first earth analog datasets to be archived by the PDS, this project could prompt the digitizing and making available of historic datasets from other facilities for the scientific community.

  6. Feasibility Study of a Lunar Analog Bed Rest Model

    Science.gov (United States)

    Cromwell, Ronita L.; Platts, Steven H.; Yarbough, Patrice; Buccello-Stout, Regina

    2010-01-01

    The purpose of this study was to determine the feasibility of using a 9.5deg head-up tilt bed rest model to simulate the effects of the 1/6 g load to the human body that exists on the lunar surface. The lunar analog bed rest model utilized a modified hospital bed. The modifications included mounting the mattress on a sled that rolled on bearings to provide freedom of movement. The weight of the sled was off-loaded using a counterweight system to insure that 1/6 body weight was applied along the long axis (z-axis) of the body. Force was verified through use of a force plate mounted at the foot of the bed. A seating assembly was added to the bed to permit periods of sitting. Subjects alternated between standing and sitting positions throughout the day. A total of 35% of the day was spent in the standing position and 65% was spent sitting. In an effort to achieve physiologic fluid shifts expected for a 1/6 G environment, subjects wore compression stockings and performed unloaded foot and ankle exercises. Eight subjects (3 females and 5 males) participated in this study. Subjects spent 13 days in the pre-bed rest phase, 6 days in bed rest and 3 days post bed rest. Subjects consumed a standardized diet throughout the study. To determine feasibility, measures of subject comfort, force and plasma volume were collected. Subject comfort was assessed using a Likert scale. Subjects were asked to assess level of comfort (0-100) for 11 body regions and provide an overall rating. Results indicated minimal to no discomfort as most subjects reported scores of zero. Force measures were performed for each standing position and were validated against subject s calculated 1/6 body weight (r(sup 2) = 0.993). The carbon monoxide rebreathing technique was used to assess plasma volume during pre-bed rest and on the last day of bed rest. Plasma volume results indicated a significant decrease (p = 0.001) from pre to post bed rest values. Subjects lost on average 8.3% (sd = 6.1%) during the

  7. Methodology for the digital calibration of analog circuits and systems with case studies

    CERN Document Server

    Pastre, Marc

    2006-01-01

    Methodology for the Digital Calibration of Analog Circuits and Systems shows how to relax the extreme design constraints in analog circuits, allowing the realization of high-precision systems even with low-performance components. A complete methodology is proposed, and three applications are detailed. To start with, an in-depth analysis of existing compensation techniques for analog circuit imperfections is carried out. The M/2+M sub-binary digital-to-analog converter is thoroughly studied, and the use of this very low-area circuit in conjunction with a successive approximations algorithm for digital compensation is described. A complete methodology based on this compensation circuit and algorithm is then proposed. The detection and correction of analog circuit imperfections is studied, and a simulation tool allowing the transparent simulation of analog circuits with automatic compensation blocks is introduced. The first application shows how the sub-binary M/2+M structure can be employed as a conventional di...

  8. Study of inelastic proton scattering at isobaric analog resonances

    International Nuclear Information System (INIS)

    Davis, S.L.

    1974-01-01

    Inelastic proton scattering at isobaric analog resonances (IAR's) was studied using the targets 138 Ba and 92 Mo. Differential cross sections and analyzing powers were measured at the 10.00, 10.63, 11.09, 11.45, and 11.70 MeV resonances in 138 Ba + p and at the 5.89, 6.09, and 6.55 MeV resonances in 92 Mo + p. In addition, a new measurement, the spin flip asymmetry, was developed. The experiment was performed by using a polarized beam to make spin flip measurements. Angular distributions for the spin flip probability and spin flip asymmetry were measured at all of the above energies except for the lowest three resonances in 138 Ba, where only the spin flip probability was measured. A DWBA code modified to include the coherent addition of resonance amplitudes was used to analyze the 138 Ba data. The partial widths extracted from this analysis were converted to expansion coefficients for parent states in 139 Ba. The coefficients were found to be in good agreement with unified model calculations. For 92 Mo, inelastic polarizations, deduced from the spin flip and spin flip asymmetry, were found to be large. Attempts using Hauser Feshbach theory to describe both the cross section and polarization data repeatedly failed for both the 6.55 and 5.87 MeV IAR's. This failure represents strong evidence that Hauser Feshbach theory is not valid when extended to describe scattering at an IAR. The 92 Mo data were analyzed using a reaction theory modified to include channel-channel correlations. This theory predicts that the enhanced compound scattering is identical to the resonance scattering. Good fits have been obtained with the use of this modified Hauser Feshbach theory. (U.S.)

  9. An In Situ Study of Analogical Reasoning in Novice and Experienced Design Engineers

    DEFF Research Database (Denmark)

    Ahmed, Saeema; Christensen, B T

    2009-01-01

    This paper describes a study to understand the use of analogies by design engineers with different levels of experience in an adaptive design domain. Protocol analyses of 12 design engineers have been analyzed to understand the functions and reasoning of the analogies. The protocols are real......-world data from the aerospace industry. The findings indicate a significant difference in both the use of analogies by novices and experienced designers and the reasoning from the analogies. Novices were found to predominantly transfer information related to the geometric properties without explicit...

  10. Embedding Analogical Reasoning into 5E Learning Model: A Study of the Solar System

    Science.gov (United States)

    Devecioglu-Kaymakci, Yasemin

    2016-01-01

    The purpose of this study was to investigate how the 5E learning model affects learning about the Solar System when an analogical model is utilized in teaching. The data were gathered in an urban middle school 7th grade science course while teaching relevant astronomy topics. The analogical model developed by the researchers was administered to 20…

  11. Habitability: Where to look for life? Halophilic habitats: Earth analogs to study Mars habitability

    Science.gov (United States)

    Gómez, F.; Rodríguez-Manfredi, J. A.; Rodríguez, N.; Fernández-Sampedro, M.; Caballero-Castrejón, F. J.; Amils, R.

    2012-08-01

    Oxidative stress, high radiation doses, low temperature and pressure are parameters which made Mars's surface adverse for life. Those conditions found on Mars surface are harsh conditions for life to deal with. Life, as we know it on Earth, needs several requirements for its establishment but, the only "sine qua nom" element is water. Extremophilic microorganisms widened the window of possibilities for life to develop in the universe, and as a consequence on Mars. Recently reported results in extreme environments indicate the possibility of presence of "oasys" for life in microniches due to water deliquescence in salts deposits. The compilation of data produced by the ongoing missions (Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Exploration Rover Opportunity) offers a completely different view from that reported by Viking missions: signs of an early wet Mars and rather recent volcanic activity. The discovery of important accumulations of sulfates, and the existence of iron minerals like jarosite, goethite and hematite in rocks of sedimentary origin has allowed specific terrestrial models related with this type of mineralogy to come into focus. Río Tinto (Southwestern Spain, Iberian Pyritic Belt) is an extreme acidic environment, product of the chemolithotrophic activity of microorganisms that thrive in the massive pyrite-rich deposits of the Iberian Pyritic Belt. The high concentration of ferric iron and sulfates, products of the metabolism of pyrite, generate a collection of minerals, mainly gypsum, jarosite, goethite and hematites, all of which have been detected in different regions of Mars. Some particular protective environments or elements could house organic molecules or the first bacterial life forms on Mars surface. Terrestrial analogs could help us to afford its comprehension. We are reporting here some preliminary studies about endolithic niches inside salt deposits used by phototrophs for taking advantage of sheltering particular light

  12. Analogical scaffolding and the learning of abstract ideas in physics: Empirical studies

    Directory of Open Access Journals (Sweden)

    Noah S. Podolefsky

    2007-09-01

    Full Text Available Previously, we proposed a model of student reasoning which combines the roles of representation, analogy, and layering of meaning—analogical scaffolding [Podolefsky and Finkelstein, Phys. Rev. ST Phys. Educ. Res. 3, 010109 (2007]. The present empirical studies build on this model to examine its utility and demonstrate the vital intertwining of representation, analogy, and conceptual learning in physics. In two studies of student reasoning using analogy, we show that representations couple to students’ existing prior knowledge and also lead to the dynamic formation of new knowledge. Students presented with abstract, concrete, or blended (both abstract and concrete representations produced markedly different response patterns. In the first study, using analogies to scaffold understanding of electromagnetic (EM waves, students in the blend group were more likely to reason productively about EM waves than students in the abstract group by as much as a factor of 3 (73% vs 24% correct, p=0.002. In the second study, examining representation use within one domain (sound waves, the blend group was more likely to reason productively about sound waves than the abstract group by as much as a factor of 2 (48% vs 23% correct, p=0.002. Using the analogical scaffolding model we examine when and why students succeed and fail to use analogies and interpret representations appropriately.

  13. Analogical scaffolding and the learning of abstract ideas in physics: Empirical studies

    Directory of Open Access Journals (Sweden)

    Noah D. Finkelstein

    2007-09-01

    Full Text Available Previously, we proposed a model of student reasoning which combines the roles of representation, analogy, and layering of meaning—analogical scaffolding [Podolefsky and Finkelstein, Phys. Rev. ST Phys. Educ. Res. 3, 010109 (2007]. The present empirical studies build on this model to examine its utility and demonstrate the vital intertwining of representation, analogy, and conceptual learning in physics. In two studies of student reasoning using analogy, we show that representations couple to students’ existing prior knowledge and also lead to the dynamic formation of new knowledge. Students presented with abstract, concrete, or blended (both abstract and concrete representations produced markedly different response patterns. In the first study, using analogies to scaffold understanding of electromagnetic (EM waves, students in the blend group were more likely to reason productively about EM waves than students in the abstract group by as much as a factor of 3 (73% vs 24% correct, p=0.002 . In the second study, examining representation use within one domain (sound waves, the blend group was more likely to reason productively about sound waves than the abstract group by as much as a factor of 2 (48% vs 23% correct, p=0.002 . Using the analogical scaffolding model we examine when and why students succeed and fail to use analogies and interpret representations appropriately.

  14. Terrestrial Analogs for Surface Properties Associated with Impact Cratering on the Moon - Self-secondary Impact Features at Kings Bowl, Idaho

    Science.gov (United States)

    Matiella Novak, M. A.; Zanetti, M.; Neish, C.; Kukko, A.; Fan, K.; Heldmann, J.; Hughes, S. S.

    2017-12-01

    The Kings Bowl (KB) eruptive fissure and lava field, located in the southern end of Craters of the Moon National Monument, Idaho, is an ideal location for planetary analogue field studies of surface properties related to volcanic and impact processes. Here we look at possible impact features present in the KB lava field near the main vent that resulted in squeeze-ups of molten lava from beneath a semi-solid lava lake crust. These may have been caused by the ejection of blocks during the phreatic eruption that formed the Kings Bowl pit, and their subsequent impact into a partially solidified lava pond. We compare and contrast these features with analogous self-secondary impact features, such as irregular, rimless secondary craters ("splash craters") observed in lunar impact melt deposits, to better understand how self-secondary impacts determine the surface properties of volcanic and impact crater terrains. We do this by analyzing field measurements of these features, as well as high-resolution DEM data collected through the Kinematic LiDAR System (KLS), both of which give us feature dimensions and distributions. We then compare these data with self-secondary impact features on the Moon and related surface roughness constrained through Lunar Reconnaissance Orbiter observations (Mini-RF and LROC NACs). Possible self-secondary impact features can be found in association with many lunar impact craters. These are formed when ballistic ejecta from the crater falls onto the ejecta blanket and melt surrounding the newly formed crater. Self-secondary impact features involving impact melt deposits are particularly useful to study because the visibly smooth melt texture serves to highlight the impact points in spacecraft imagery. The unusual morphology of some of these features imply that they formed when the melt had not yet completely solidified, strongly suggesting a source of impactors from the primary crater itself. We will also discuss ongoing efforts to integrate field

  15. Analogical study of the servo-control of a reactivity modulator

    International Nuclear Information System (INIS)

    Le Bot, Michel

    1969-03-01

    In the context of the study of the transfer functions related to the Cabri reactor, this paper presents: the objective of the servo-control (reactivity modulator, reasons for the analogical study), the principles of the servo-control (description of the servo-controlled system, elaboration of the error signal, principles of the phase meter, critical analysis of different types of phase meters), the analogical formulation (transfer diagram of the process, analogical simulation of the process, analogical realization of the phase meter, simulation of the Low Frequency generator), study of the controlled system and results (system responses to echelon and ramp signals, responses of the controlled system with the phase meter in feedback)

  16. Astrobiology through the ages of Mars: the study of terrestrial analogues to understand the habitability of Mars.

    Science.gov (United States)

    Fairén, Alberto G; Davila, Alfonso F; Lim, Darlene; Bramall, Nathan; Bonaccorsi, Rosalba; Zavaleta, Jhony; Uceda, Esther R; Stoker, Carol; Wierzchos, Jacek; Dohm, James M; Amils, Ricardo; Andersen, Dale; McKay, Christopher P

    2010-10-01

    Mars has undergone three main climatic stages throughout its geological history, beginning with a water-rich epoch, followed by a cold and semi-arid era, and transitioning into present-day arid and very cold desert conditions. These global climatic eras also represent three different stages of planetary habitability: an early, potentially habitable stage when the basic requisites for life as we know it were present (liquid water and energy); an intermediate extreme stage, when liquid solutions became scarce or very challenging for life; and the most recent stage during which conditions on the surface have been largely uninhabitable, except perhaps in some isolated niches. Our understanding of the evolution of Mars is now sufficient to assign specific terrestrial environments to each of these periods. Through the study of Mars terrestrial analogues, we have assessed and constrained the habitability conditions for each of these stages, the geochemistry of the surface, and the likelihood for the preservation of organic and inorganic biosignatures. The study of these analog environments provides important information to better understand past and current mission results as well as to support the design and selection of instruments and the planning for future exploratory missions to Mars.

  17. The neural substrate of analogical reasoning: an fMRI study.

    Science.gov (United States)

    Luo, Qian; Perry, Conrad; Peng, Danling; Jin, Zhen; Xu, Duo; Ding, Guosheng; Xu, Shiyong

    2003-10-01

    This study investigated the anatomical substrate of analogical reasoning using functional magnetic resonance imaging. In the study, subjects performed a verbal analogy task (e.g., soldier is to army as drummer is to band) and, to control for activation caused by purely semantic access, a semantic judgment task. Significant activation differences between the verbal analogy and the semantic judgment task were found bilaterally in the prefrontal cortex (right BA 11/BA 47 and left BA45), the fusiform gyrus, and the basal ganglia; left lateralized in the postero-superior temporal gyrus (BA 22) and the (para) hippocampal region; and right lateralized in the anterior cingulate. The role of these areas in analogical reasoning is discussed.

  18. The Cigar Lake analog study: An international R ampersand D project

    International Nuclear Information System (INIS)

    Cramer, J.J.; Sargent, F.P.

    1994-01-01

    This paper provides background information and summarizes the results of AECL's analog study on the Cigar Lake uranium deposit. This R ampersand D project includes national and international cooperation with many organizations directly or indirectly involved in nuclear waste management research. The emphasis is on the analog aspects of this deposit and the implications of modelling activities related to the environmental and safety assessment of the Canadian disposal concept for nuclear fuel waste

  19. Study of time variation of terrestrial gamma radiation due to depth distribution of soil moisture content

    International Nuclear Information System (INIS)

    Yoshioka, Katsuhiro

    1994-01-01

    An empirical equation was deduced from studies of time variations of terrestrial gamma exposure rate and soil moisture content with depth distribution in the surface layer. It was definitely suggested that the variation of terrestrial gamma exposure rate is most strongly influenced by the change of soil moisture content at 5 cm depth. The seasonal variation with a relative maximum in early autumn and a relative minimum in early spring was clearly obtained in the consequence of long time measurements of terrestrial gamma exposure rate and degree of soil dryness. The diurnal change and phase difference due to the effect of depth were also obtained in the dynamic characteristics of soil moisture content at 3 different depths. From the comparison between measured terrestrial gamma exposure rate and that evaluated from soil moisture content using the empirical equation, it was seen that seasonal variations of the both agreed fairly well as a whole. (author)

  20. General and specialized brain correlates for analogical reasoning: A meta-analysis of functional imaging studies.

    Science.gov (United States)

    Hobeika, Lucie; Diard-Detoeuf, Capucine; Garcin, Béatrice; Levy, Richard; Volle, Emmanuelle

    2016-05-01

    Reasoning by analogy allows us to link distinct domains of knowledge and to transfer solutions from one domain to another. Analogical reasoning has been studied using various tasks that have generally required the consideration of the relationships between objects and their integration to infer an analogy schema. However, these tasks varied in terms of the level and the nature of the relationships to consider (e.g., semantic, visuospatial). The aim of this study was to identify the cerebral network involved in analogical reasoning and its specialization based on the domains of information and task specificity. We conducted a coordinate-based meta-analysis of 27 experiments that used analogical reasoning tasks. The left rostrolateral prefrontal cortex was one of the regions most consistently activated across the studies. A comparison between semantic and visuospatial analogy tasks showed both domain-oriented regions in the inferior and middle frontal gyri and a domain-general region, the left rostrolateral prefrontal cortex, which was specialized for analogy tasks. A comparison of visuospatial analogy to matrix problem tasks revealed that these two relational reasoning tasks engage, at least in part, distinct right and left cerebral networks, particularly separate areas within the left rostrolateral prefrontal cortex. These findings highlight several cognitive and cerebral differences between relational reasoning tasks that can allow us to make predictions about the respective roles of distinct brain regions or networks. These results also provide new, testable anatomical hypotheses about reasoning disorders that are induced by brain damage. Hum Brain Mapp 37:1953-1969, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  1. Tribulus terrestris for treatment of sexual dysfunction in women: randomized double-blind placebo - controlled study

    Science.gov (United States)

    2014-01-01

    Background Tribulus terrestris as a herbal remedy has shown beneficial aphrodisiac effects in a number of animal and human experiments. This study was designed as a randomized double-blind placebo-controlled trial to assess the safety and efficacy of Tribulus terrestris in women with hypoactive sexual desire disorder during their fertile years. Sixty seven women with hypoactive sexual desire disorder were randomly assigned to Tribulus terrestris extract (7.5 mg/day) or placebo for 4 weeks. Desire, arousal, lubrication, orgasm, satisfaction, and pain were measured at baseline and after 4 weeks after the end of the treatment by using the Female Sexual Function Index (FSFI). Two groups were compared by repeated measurement ANOVA test. Results Thirty women in placebo group and thirty women in drug group completed the study. At the end of the fourth week, patients in the Tribulus terrestris group had experienced significant improvement in their total FSFI (p Tribulus terrestris may safely and effectively improve desire in women with hypoactive sexual desire disorder. Further investigation of Tribulus terrestris in women is warranted. PMID:24773615

  2. Tribulus terrestris for treatment of sexual dysfunction in women: randomized double-blind placebo - controlled study.

    Science.gov (United States)

    Akhtari, Elham; Raisi, Firoozeh; Keshavarz, Mansoor; Hosseini, Hamed; Sohrabvand, Farnaz; Bioos, Soodabeh; Kamalinejad, Mohammad; Ghobadi, Ali

    2014-04-28

    Tribulus terrestris as a herbal remedy has shown beneficial aphrodisiac effects in a number of animal and human experiments. This study was designed as a randomized double-blind placebo-controlled trial to assess the safety and efficacy of Tribulus terrestris in women with hypoactive sexual desire disorder during their fertile years. Sixty seven women with hypoactive sexual desire disorder were randomly assigned to Tribulus terrestris extract (7.5 mg/day) or placebo for 4 weeks. Desire, arousal, lubrication, orgasm, satisfaction, and pain were measured at baseline and after 4 weeks after the end of the treatment by using the Female Sexual Function Index (FSFI). Two groups were compared by repeated measurement ANOVA test. Thirty women in placebo group and thirty women in drug group completed the study. At the end of the fourth week, patients in the Tribulus terrestris group had experienced significant improvement in their total FSFI (p Tribulus terrestris may safely and effectively improve desire in women with hypoactive sexual desire disorder. Further investigation of Tribulus terrestris in women is warranted.

  3. Durable terrestrial bedrock predicts submarine canyon formation

    Science.gov (United States)

    Smith, Elliot; Finnegan, Noah J.; Mueller, Erich R.; Best, Rebecca J.

    2017-01-01

    Though submarine canyons are first-order topographic features of Earth, the processes responsible for their occurrence remain poorly understood. Potentially analogous studies of terrestrial rivers show that the flux and caliber of transported bedload are significant controls on bedrock incision. Here we hypothesize that coarse sediment load could exert a similar role in the formation of submarine canyons. We conducted a comprehensive empirical analysis of canyon occurrence along the West Coast of the contiguous United States which indicates that submarine canyon occurrence is best predicted by the occurrence of durable crystalline bedrock in adjacent terrestrial catchments. Canyon occurrence is also predicted by the flux of bed sediment to shore from terrestrial streams. Surprisingly, no significant correlation was observed between canyon occurrence and the slope or width of the continental shelf. These findings suggest that canyon incision is promoted by greater yields of durable terrestrial clasts to the shore.

  4. Barrier analogs: Long-term performance issues, preliminary studies, and recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Waugh, W.J. [Rust Geotech, Inc., Grand Junction, CO (United States). Environmental Sciences Lab.; Chatters, J.C.; Last, G.V.; Bjornstad, B.N.; Link, S.O. [Pacific Northwest Lab., Richland, WA (United States); Hunter, C.R. [Cascade Earth Sciences, La Grande, OR (United States)

    1994-02-01

    The US Department of Energy`s Hanford Protective Barrier Development Program is funding studies of natural analogs of the long-term performance of waste site covers. Natural-analog studies examine past environments as evidence for projecting the future performance of engineered structures. The information generated by analog studies is needed to (1) evaluate the designs and results of short term experiments and demonstrations, (2) formulate performance-modeling problems that bound expected changes in waste site environments, and (3) understand emergent system attributes that cannot be evaluated with short-term experiments or computer models. Waste site covers will be part of dynamic environmental systems with attributes that transcend the traits of engineered components. This report discusses results of the previously unreported preliminary studies conducted in 1983 and 1984. These results indicate that analogs could play an important role in predicting the long-term behavior of engineered waste covers. Layered exposures of glacial-flood-deposited gravels mantled with silt or sand that resemble contemporary barrier designs were examined. Bergmounds, another anomaly left by cataclysmic glacial floods, were also examined as analogs of surface gravel.

  5. Use of Nucleic Acid Analogs for the Study of Nucleic Acid Interactions

    Directory of Open Access Journals (Sweden)

    Shu-ichi Nakano

    2011-01-01

    Full Text Available Unnatural nucleosides have been explored to expand the properties and the applications of oligonucleotides. This paper briefly summarizes nucleic acid analogs in which the base is modified or replaced by an unnatural stacking group for the study of nucleic acid interactions. We also describe the nucleoside analogs of a base pair-mimic structure that we have examined. Although the base pair-mimic nucleosides possess a simplified stacking moiety of a phenyl or naphthyl group, they can be used as a structural analog of Watson-Crick base pairs. Remarkably, they can adopt two different conformations responding to their interaction energies, and one of them is the stacking conformation of the nonpolar aromatic group causing the site-selective flipping of the opposite base in a DNA double helix. The base pair-mimic nucleosides can be used to study the mechanism responsible for the base stacking and the flipping of bases out of a nucleic acid duplex.

  6. Uranium determinations by 133Xe in terrestrial zircon, apatite and chromite; comparative study of thermal releases of fissiogenic xenon from terrestrial and meteoritic minerals

    International Nuclear Information System (INIS)

    Sakamoto, K.; Hamajima, Y.; Itoh, K.; Yamazaki, K.

    1980-01-01

    Terrestrial zircon and apatite, as examples of uranium rich refractory minerals, and chromite, also highly refractory but uranium poor, were neutron-irradiated for their 133 Xe release studies. Uranium determination by 133 Xe was found not to be successful in these refractory samples, due to incomplete fissiogenic-xenon release at 1600 deg C as revealed by stepwise heating experiment. In these terrestrial materials the high temperature release peaks appeared at >=1500 deg C, but in meteoritic whitlockite and chromite values of 1000 approximately 1200 deg C were reported. (author)

  7. Terrestrial analogs for interpretation of infrared spectra from the Martian surface and subsurface: Sulfate, nitrate, carbonate, and phyllosilicate-bearing Atacama Desert soils

    Science.gov (United States)

    Sutter, B.; Dalton, J. B.; Ewing, S. A.; Amundson, R.; McKay, C. P.

    2007-10-01

    Hyperarid (Mars soils have similar sulfate concentrations; possess phyllosilicates (e.g., smectite) and minor carbonate. Nitrate has not been detected on Mars, but its presence has been proposed. The similar compositions of Atacama and Mars soils have prompted the visible-infrared (0.35-25 μm) investigation of Atacama soils as Mars analogs. Results from this work determined the best infrared features for detecting sulfate, nitrate, carbonate, and phyllosilicate on Mars. The fundamental region (>6.5 μm) was not suited for salt and phyllosilicate detection because of overlapping spectra from primary silicates (e.g., feldspar), water and carbon dioxide. The visible near-infrared (0.35-2.5 μm) region was suited for detecting carbonate, nitrate, gypsum water of hydration, and phyllosilicate hydroxyls without interference from primary silicates. However, gypsum water of hydration features can obscure phyllosilicate hydroxyl, carbonate and nitrate, features if gypsum levels are high. Overtone/combination absorption features in the midinfrared were determined to be the best indicators of sulfate (4.48-4.70 μm), nitrate (4.12 μm), and carbonate (3.98 μm) because interferences from overlapping primary silicate and water features are not present in this region. Interferences from CO2 and thermal emission effects in the overtone/combination region are possible but may be minimized by corrective techniques. Infrared analysis of Atacama Desert soils can provide insight into the spectral search of sulfate, nitrate, carbonate, and phyllosilicate containing soils on Mars.

  8. Assessment of planetary geologic mapping techniques for Mars using terrestrial analogs: The SP Mountain area of the San Francisco Volcanic Field, Arizona

    Science.gov (United States)

    Tanaka, K.L.; Skinner, J.A.; Crumpler, L.S.; Dohm, J.M.

    2009-01-01

    We photogeologically mapped the SP Mountain region of the San Francisco Volcanic Field in northern Arizona, USA to evaluate and improve the fidelity of approaches used in geologic mapping of Mars. This test site, which was previously mapped in the field, is chiefly composed of Late Cenozoic cinder cones, lava flows, and alluvium perched on Permian limestone of the Kaibab Formation. Faulting and folding has deformed the older rocks and some of the volcanic materials, and fluvial erosion has carved drainage systems and deposited alluvium. These geologic materials and their formational and modificational histories are similar to those for regions of the Martian surface. We independently prepared four geologic maps using topographic and image data at resolutions that mimic those that are commonly used to map the geology of Mars (where consideration was included for the fact that Martian features such as lava flows are commonly much larger than their terrestrial counterparts). We primarily based our map units and stratigraphic relations on geomorphology, color contrasts, and cross-cutting relationships. Afterward, we compared our results with previously published field-based mapping results, including detailed analyses of the stratigraphy and of the spatial overlap and proximity of the field-based vs. remote-based (photogeologic) map units, contacts, and structures. Results of these analyses provide insights into how to optimize the photogeologic mapping of Mars (and, by extension, other remotely observed planetary surfaces). We recommend the following: (1) photogeologic mapping as an excellent approach to recovering the general geology of a region, along with examination of local, high-resolution datasets to gain insights into the complexity of the geology at outcrop scales; (2) delineating volcanic vents and lava-flow sequences conservatively and understanding that flow abutment and flow overlap are difficult to distinguish in remote data sets; (3) taking care to

  9. The neuromechanism underlying verbal analogical reasoning of metaphorical relations: an event-related potentials study.

    Science.gov (United States)

    Zhao, Ming; Meng, Huishan; Xu, Zhiyuan; Du, Fenglei; Liu, Tao; Li, Yongxin; Chen, Feiyan

    2011-11-24

    Using event-related potentials (ERPs), this study investigated the neuromechanism underlying verbal analogical reasoning of two different metaphorical relations: attributive metaphor and relational metaphor. The analogical reasoning of attributive metaphor (AM-AR) involves a superficial similarity between analogues, while the analogical reasoning of relational metaphor (RM-AR) requires a structural similarity. Subjects were asked to judge whether one word pair was semantically analogous to another word pair. Results showed that the schema induction stage elicited a greater N400 component at the right anterior scalp for the AM-AR and RM-AR tasks, possibly attributable to semantic processing of metaphorical word pairs. The N400 was then followed by a widely distributed P300 and a late negative component (LNC1) at the left anterior scalp. The P300 was possibly related to the formation of a relational category, while the LNC1 was possibly related to the maintenance of a reasoning cue in working memory. The analogy mapping stage elicited broadly distributed N400 and LNC2, which might indicate the presence of semantic retrieval and analogical transfer. In the answer production stage, all conditions elicited the P2 component due to early stimulus encoding. The largest P2 amplitude was in the RM-AR task. The RM-AR elicited a larger LPC than did the AM-AR, even though the baseline correction was taken as a control for the differential P2 effect. The LPC effect might suggest that relational metaphors involved more integration processing than attributive metaphors. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Analog study of the second re-extraction line of the La Hague plant

    International Nuclear Information System (INIS)

    Bory, M.; Francois, N.

    1966-01-01

    This study, realized on an analog computer, aims to determine the behavior of an uranium and plutonium re-extraction line in dynamical state. The system perturbations are temperature and acidity variations of aqueous phase and variations of the TBP of the solvent. The uranium contents variations are described. (A.L.B.)

  11. A study on the application of two different acoustic analogies to experimental PIV data

    NARCIS (Netherlands)

    Koschatzky, V.; Westerweel, J.; Boersma, B.J.

    2011-01-01

    The aim of the present study is to compare two different acoustic analogies applied to time-resolved particle image velocimetry (PIV) data for the prediction of the acoustic far-field generated by the flow over a rectangular cavity. We consider the model problem of sound radiating from an open,

  12. A dual use case study of space technologies for terrestrial medical applications (Conference Presentation)

    Science.gov (United States)

    Cozmuta, Ioana

    2017-05-01

    Many challenges exist in understanding the human body as a whole, its adaptability, its resilience, its immunological response, its healing and regeneration power. New knowledge is usually obtained by exploring unique conditions and environments and space is one such variable. Primarily, these attributes have been studied in space for the purpose of understanding the effect of the space environment on long duration space travel. However a myriad of lessons learned have emerged that are important for terrestrial medicine problems such as cardiovascular changes, intracranial pressure changes, vision changes, reduced immunity, etc. For medical study purposes, the changes induced by the space environment on the human body are in general fast and predictable; they persist while in the space environment but also revert to the initial pre-flight healthy state upon return to Earth. This provides a unique cycle to study wellness and disease prediction as well as to develop more effective countermeasures for the benefit of people on earth. At a scientific level, the environment of space can be used to develop new lines of investigations and new knowledge to push the terrestrial state of the art (i.e. study of phase diagrams, identification of new system's states, etc). Moreover, the specialized requirements for space medicine have driven advances in terrestrial medical technologies in areas such as monitoring, diagnostic, prevention and treatment. This talk will provide an overview of compelling examples in key areas of interest for terrestrial medical applications.

  13. Exploring trade-offs between carbon storage, yield and biodiversity in analog forestry. A case study in the Peruvian Amazon

    Science.gov (United States)

    Recanati, F.; Saini, M.; Guariso, G.; Melia, P.

    2016-12-01

    Creation and management of agro-ecosystems can considerably influence the greenhouse gas exchange between terrestrial ecosystems and atmosphere. This is especially evident for tropical areas, where the expansion of agricultural lands for monoculture is among the main causes of deforestation and consequent CO2 emissions. In these contexts, agro-ecological approaches, such as analog forestry, seem promising alternatives to intensive ones. Analog forestry is usually created for reforestation purposes through the combination of ecological succession and architecture of natural forests (i.e., inclusion of species from shrubs to higher trees). Besides provisioning a variety of food and medicinal products, they provide high levels of biodiversity (compared to other agricultural practices) and important ecosystem services, like carbon storage. Given the complexity of such agro-ecosystems, this study aims to estimate the quantity of carbon that can be stored in an analog forest as a function of its species composition. Consequently, trade-offs between performances in terms of carbon storage, productivity and biodiversity are explored. The analysis focuses on the Peruvian region of Madre de Dios, where native forest and its biodiversity is threatened by intensive agriculture. To quantify plant above- and belowground biomass and the related carbon content, we feed appropriate allometric models with plant morphological information gathered in the field. Relying on our database of productive plant species suitable for the region, we formulate an optimization problem aimed at the selection of plant population under different constraint systems. The latter are defined according to possible farmers' preferences (e.g., average profitability or multi-functionality). The analysis refers to the farm-scale and is performed over medium-term horizon (i.e., 40 years), in order to take into account important plant dynamics (species growth and the evolution of shade interaction

  14. Periglacial and glacial analogs for Martian landforms

    Science.gov (United States)

    Rossbacher, Lisa A.

    1992-01-01

    The list of useful terrestrial analogs for Martian landforms has been expanded to include: features developed by desiccation processes; catastrophic flood features associated with boulder-sized materials; and sorted ground developed at a density boundary. Quantitative analytical techniques developed for physical geography have been adapted and applied to planetary studies, including: quantification of the patterns of polygonally fractured ground to describe pattern randomness independent of pattern size, with possible correlation to the mechanism of origin and quantification of the relative area of a geomorphic feature or region in comparison to planetary scale. Information about Martian geomorphology studied in this project was presented at professional meetings world-wide, at seven colleges and universities, in two interactive televised courses, and as part of two books. Overall, this project has expanded the understanding of the range of terrestrial analogs for Martian landforms, including identifying several new analogs. The processes that created these terrestrial features are characterized by both cold temperatures and low humidity, and therefore both freeze-thaw and desiccation processes are important. All these results support the conclusion that water has played a significant role in the geomorphic history of Mars.

  15. Study of the orientation of retinal in bovine rhodopsin: the use of a photoactivatable retinal analog

    International Nuclear Information System (INIS)

    Nakayama, T.

    1987-01-01

    Rhodopsin is the major transmembrane protein in the photoreceptor cells of vertebrate and invertebrate retina. Bovine rhodopsin consists of a polypeptide chain of 348 amino acids of known sequence in which the chromophore, 11-cis-retinal, is linked to Lys-296 as a Schiff base. To investigate the orientation of retinal in the protein and to study the interactions between retinal and the protein, the authors have developed a crosslinking approach using a 3 H-labeled photoactivatable analog of retinal. Bleached rhodopsin in rod outer segments was reconstituted with the analog to give a pigment with λ/sub max/ at 460nm. Reduction of the Schiff base with borane dimenthylamine, followed by degradation with CNBr and sequencing of the radioactive fragment showed that the analog is attached to Lys-296, as in the native rhodopsin. Further, the reconstitute protein after photolysis was phosphorylated by rhodopsin kinase. Photolysis of the reconstituted pigment at -15 0 C resulted in crosslinking of the analog to the opsin to the extent of 30% as analyzed by SDS electrophoresis. The site(s) of crosslinking in the protein are under investigation

  16. A STUDY ABOUT TERRESTRIAL LASER SCANNING FOR RECONSTRUCTION OF PRECAST CONCRETE TO SUPPORT QLASSIC ASSESSMENT

    Directory of Open Access Journals (Sweden)

    M. A. Aziz

    2016-09-01

    Full Text Available Nowadays, terrestrial laser scanning shows the potential to improve construction productivity by measuring the objects changes using real-time applications. This paper presents the process of implementation of an efficient framework for precast concrete using terrestrial laser scanning that enables contractors to acquire accurate data and support Quality Assessment System in Construction (QLASSIC. Leica Scanstation C10, black/white target, Autodesk Revit and Cyclone software were used in this study. The results were compared with the dimensional of based model precast concrete given by the company as a reference with the AutoDesk Revit model from the terrestrial laser scanning data and conventional method (measuring tape. To support QLASSIC, the tolerance dimensions of cast in-situ & precast elements is +10mm / -5mm. The results showed that the root mean square error for a Revit model is 2.972mm while using measuring tape is 13.687mm. The accuracy showed that terrestrial laser scanning has an advantage in construction jobs to support QLASSIC.

  17. a Study about Terrestrial Laser Scanning for Reconstruction of Precast Concrete to Support Qlassic Assessment

    Science.gov (United States)

    Aziz, M. A.; Idris, K. M.; Majid, Z.; Ariff, M. F. M.; Yusoff, A. R.; Luh, L. C.; Abbas, M. A.; Chong, A. K.

    2016-09-01

    Nowadays, terrestrial laser scanning shows the potential to improve construction productivity by measuring the objects changes using real-time applications. This paper presents the process of implementation of an efficient framework for precast concrete using terrestrial laser scanning that enables contractors to acquire accurate data and support Quality Assessment System in Construction (QLASSIC). Leica Scanstation C10, black/white target, Autodesk Revit and Cyclone software were used in this study. The results were compared with the dimensional of based model precast concrete given by the company as a reference with the AutoDesk Revit model from the terrestrial laser scanning data and conventional method (measuring tape). To support QLASSIC, the tolerance dimensions of cast in-situ & precast elements is +10mm / -5mm. The results showed that the root mean square error for a Revit model is 2.972mm while using measuring tape is 13.687mm. The accuracy showed that terrestrial laser scanning has an advantage in construction jobs to support QLASSIC.

  18. Terrestrial invertebrate population studies in the Chernobyl exclusion zone, Ukraine

    International Nuclear Information System (INIS)

    Jackson, D.; Stone, D.M.; Copplestone, D.; Gilhen, M.C.

    2004-01-01

    The Chernobyl reactor accident in April 1986 caused the release to atmosphere of substantial amounts of radioactivity. Precise estimates of the release vary. The USSR State Committee presented information to a meeting of the International Atomic Energy Agency in August 1986 indicating a release of some 2.9x10 5 TBq 137 Cs and 2x10 5 TBq 90 Sr, with a total fission/activation product release of 1.7x10 6 TBq. Other commentators suggest that up to double this amount may have been released. Estimates of deposition likewise vary, although it is probable that about half the released activity was deposited within 20 km of the release point, predominantly following two plume trajectories to the north and west. This resulted in the death of pine trees over 400 ha, the abandonment of 100,000 to 150,000 ha of agricultural land and the establishment of an exclusion zone extending to 30 km from the site. High levels of radionuclide contamination continue to prevail within the exclusion zone. Nonetheless, over the past fifteen years, re-colonisation has been widespread. Mixed deciduous woodlands, with a high proportion of birch (Betula spp.) and willow (Salix spp.), have become established in the forest areas, while agricultural land has succeeded to tall grassland and scrub. Field sites established in this study exhibited external gamma dose rates varying from 0.1 μSv h -1 to 140 μSv h -1 . Corresponding mean concentrations of 137 Cs in the top 20 cm of soil varied from about 6.10 2 to 3.10 6 Bq kg -1 dw. This study summarises observations over the period 2001 to 2004. Sub-surface activity, as measured by bait lamina penetration, appears to be inversely correlated with concentrations of 137 Cs and 90 Sr in soil. Likewise, at the very highest levels of contamination, there is some loss of invertebrate diversity; although little associated change in overall biomass. Between years, population densities and species dominance vary significantly. This does not appear to correlate

  19. Final report of the AECL/SKB Cigar Lake analog study. AECL research No. AECL-10851

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, J J; Smellie, J A.T. [eds.

    1994-07-15

    AECL has conducted natural analog studies on the Cigar Lake uranium deposit in northern Saskatchewan since 1984 as part of the Canadian Nuclear Fuel Waste Management Program. This report provides background information and summarizes the results of the study, emphasizing the analog aspects and the implications of modelling activities related to the performance assessment of disposal concepts for nuclear fuel wastes developed in both Canada and Sweden. The study was undertaken to obtain an understanding of the process involved in, and the effects of, steady-state water-rock interaction and trace-element migration in and around the deposit, including paleo-migration processes since the deposit was formed. To achieve these objectives, databases and models were produced to evaluate the equilibrium thermodynamic codes and databases; the role of colloids, organics, and microbes in transport processes for radionuclides; and the stability of UO2 and the influence of radiolysis on UO2 dissolution and radionuclide migration.

  20. Using Analogies in Teaching Physics: A Study on Latvian Teachers' Views and Experience

    Science.gov (United States)

    Jonane, Lolita

    2015-01-01

    The role of analogies as tools for teaching difficult science concepts has been widely discussed in science education. The application of analogies in the context of sustainable education involves richer potential. The purposeful use of appropriate analogies can facilitate analogical thinking and transfer skills, as well as develop abilities which…

  1. Comparative study of digital laser film and analog paper image recordings

    International Nuclear Information System (INIS)

    Lee, K.R.; Cox, G.G.; Templeton, A.W.; Preston, D.F.; Anderson, W.H.; Hensley, K.S.; Dwyer, S.J.

    1987-01-01

    The increase in the use of various imaging modalities demands higher quality and more efficacious analog image recordings. Laser electronic recordings with digital array prints of 4,000 x 5,000 x 12 bits obtained using laser-sensitive film or paper are being evaluated. Dry silver paper recordings are being improved and evaluated. High-resolution paper dot printers are being studied to determine their gray-scale capabilities. The authors evaluated the image quality, costs, clinical utilization, and acceptability of CT scans, MR images, digital subtraction angiograms, digital radiographs, and radionuclide scans recorded by seven different printers (three laser, three silver paper, and one dot) and compared the same features in conventional film recording. This exhibit outlines the technical developments and instrumentation of digital laser film and analog paper recorders and presents the results of the study

  2. Application of the Analog Method to Modelling Heat Waves: A Case Study with Power Transformers

    Science.gov (United States)

    2017-04-21

    UNCLASSIFIED Massachusetts Institute of Technology Lincoln Laboratory APPLICATION OF THE ANALOG METHOD TO MODELLING HEAT WAVES: A CASE STUDY WITH...18 2 Calibration and validation statistics with the use of five atmospheric vari- ables to construct analogue diagnostics for JJA of transformer T2...electrical grid as a series of nodes (transformers) and edges (transmission lines) so that basic mathematical anal- ysis can be performed. The mathematics

  3. Antiproliferative effects of an analog of curcumin in Hep-2 cells: a comparative study with curcumin.

    Science.gov (United States)

    Kumaravel, Mohankumar; Sankar, Pajaniradje; Latha, Periyasamy; Benson, Chellakan S; Rukkumani, Rajagopalan

    2013-02-01

    Curcumin, the major active principle of Curcuma longa, is one of the promising, plant-derived, chemopreventive agents being studied for its anticarcinogenic and antioxidant properties. Hence, in our study, we aimed at testing the antiproliferative efficacy of an o-hydroxyl substituted analog of curcumin, bis demethoxy curcumin analog (BDMC-A), and comparing its efficacy with that of curcumin. BDMC-A was synthesised with a yield of 78% and 98% purity. Hep-2 cells and the MTT cell viability assay were used to examine cell proliferation. LDH assay and cell counts were performed to assess the cytotoxicity and anti-proliferative effects of the compound, respectively. Flow cytometry followed by Western blot were performed to investigate the cell cycle distribution. BDMC-A inhibited cell proliferation at a much lower concentration (IC50 20 microM) than curcumin (IC50 50 microM). Similar effects were observed in the LDH release and cell count assays. Flow cytometric studies using propidium iodide showed accumulation of cells in the G0/G1 phase and the arrest was further confirmed by immunoblotting of protein cyclin D1. BDMC-A was more potent in inhibiting the cells at a lower dose when compared with curcumin. Our results showed that the analog of curcumin is likely to possess more efficacy compared with curcumin in inhibiting cancer.

  4. U-Series Transport Studies at the Pena Blanca, Mexico Natural Analog Site

    Energy Technology Data Exchange (ETDEWEB)

    A. M. Simmons; M. T. Murrell

    2001-05-31

    Natural analogs provide a line of evidence that supports the understanding of how natural and engineered processes would occur over long time frames and large spatial scales at a potential nuclear waste repository at Yucca Mountain, Nevada. Studies of U-series disequilibria within and around uranium deposits can provide valuable information on the timing of actinide mobility and hence the stability of a potential repository over geologic time scales. The Nopal I uranium deposit at Pena Blanca, Mexico, is situated in unsaturated tuff that is similar in composition to the Topopah Spring Tuff of Yucca Mountain and closely matches other evaluation criteria for suitable natural analogs. By modeling the observed radioactive isotope disequilibria at Nopal I, we can estimate the rates of sorption-desorption and dissolution-precipitation of the radionuclides over time. Such information is vital to the testing or validation of performance assessment models for geologic nuclear waste disposal.

  5. U-Series Transport Studies at the Pena Blanca, Mexico Natural Analog Site

    International Nuclear Information System (INIS)

    Simmons, A. M.; Murrell, M. T.

    2001-01-01

    Natural analogs provide a line of evidence that supports the understanding of how natural and engineered processes would occur over long time frames and large spatial scales at a potential nuclear waste repository at Yucca Mountain, Nevada. Studies of U-series disequilibria within and around uranium deposits can provide valuable information on the timing of actinide mobility and hence the stability of a potential repository over geologic time scales. The Nopal I uranium deposit at Pena Blanca, Mexico, is situated in unsaturated tuff that is similar in composition to the Topopah Spring Tuff of Yucca Mountain and closely matches other evaluation criteria for suitable natural analogs. By modeling the observed radioactive isotope disequilibria at Nopal I, we can estimate the rates of sorption-desorption and dissolution-precipitation of the radionuclides over time. Such information is vital to the testing or validation of performance assessment models for geologic nuclear waste disposal

  6. Analogical Thinking for Generation of Innovative Ideas: An Exploratory Study of Influential Factors

    Directory of Open Access Journals (Sweden)

    Eunyoung Kim

    2016-07-01

    Full Text Available Analogical thinking is one of the most effective tools to generate innovative ideas. It enables us to develop new ideas by transferring information from well-known domains and utilizing them in a novel domain. However, using analogical thinking does not always yield appropriate ideas, and there is a lack of consensus among researchers regarding the evaluation methods for assessing new ideas. Here, we define the appropriateness of generated ideas as having high structural and low superficial similarities with their source ideas. This study investigates the relationship between thinking process and the appropriateness of ideas generated through analogical thinking. We conducted four workshops with 22 students in order to collect the data. All generated ideas were assessed based on the definition of appropriateness in this study. The results show that participants who deliberate more before reaching the creative leap stage and those who are engaged in more trial and error for deciding the final domain of a new idea have a greater possibility of generating appropriate ideas. The findings suggest new strategies of designing workshops to enhance the appropriateness of new ideas.

  7. Use of natural analog and modeling studies to constrain the effects of magmatic activity on long-term geologic repositories

    International Nuclear Information System (INIS)

    Valentine, G.A.; Rosenberg, N.D.; Crowe, B.M.; Perry, F.V.

    1995-01-01

    Examples of the application of natural-analog studies to the estimation of the consequences of a volcanic eruption penetrating a radioactive waste repository are given, including the criteria for analog selection and new data from ongoing studies. Examples of early modeling results focusing on the spatial and temporal scale of subsurface processes are also provided. All of these examples are taken from studies of the potential Yucca Mountain repository, Nevada, but similar approaches could be applied in other areas. In addition, studies of subsurface processes initiated by magmatic events serve as useful analogs for repository thermal loading studies

  8. Preliminary studies of 99mTc labeled fatty acid analogs for myocardial imaging

    International Nuclear Information System (INIS)

    Guo Yuzhi; Kung, H.F.; Mack, R.H.

    1988-01-01

    Radio iodine labelled fatty acid analogs are potential myocardial imaging agents for SPECT. In this paper are reported three new 99m Tc labbeled fatty acid analogs: 9 '9 m Tc-BAT-TDA, 99m Tc-BAT-PDA and 99m Tc-BAT-H x DA. Ligand exchange reaction with 99m Tc stannous glucoheptonate in 50% aqueous ethanol is used for labelling. The yield of reactions is 87%, 70%, 49% respectively. 99m Tc-fatty acid is purified by extraction into chloroform and the purity as determined by reverse phase HPLC is 98%. In order to determine the structure of Tc-BAT-fatty acid, 99 Tc-BAT-PDA is synthesized with 99 Tc ammonium pertechnetate in 50% citric acid buffer (pH=6)/ethanol using stannous chloride as the reducing agent. 99 Tc-BAT-PDA displays the expected Tc=O UV absorption at 420nm and strong peak at 900cm -1 in the FTIR spectrum. Biodistribution studies of three 99m Tc-fatty acid analogs are conducted in rats using 125 I-ω- (p-iodophenyl) -penta-decanoic acid (IPPDA) as internal standard. The initial heart uptake of them is significantly lower than that of 125 I-IPPDA

  9. Final report of the AECL/SKB Cigar Lake analog study

    International Nuclear Information System (INIS)

    Cramer, J.

    1994-05-01

    The Cigar Lake uranium deposit is located in northern Saskatchewan, Canada. The 1.3-billion-year-old deposit is located at a depth of about 450 m below surface in a water-saturated sandstone at the unconformity contact with the high-grade metamorphic rocks of the Canadian Shield. The Cigar Lake deposit has many features that parallel those being considered within the Canadian concept for disposal of nuclear fuel waste. The study of these natural structures and processes provides valuable insight toward the eventual design and site selection of a nuclear fuel waste repository. The main feature of this analog is the absence of any indication on the surface of the rich uranium ore 450 m below. This indicates that the combination of natural barriers has been effective in isolating the uranium ore from the surface environment. More specifically, the deposit provides analog information relevant to the stability of UO 2 fuel waste, the performance of clay-based barriers, radionuclide migration, colloid formation, radiolysis, fission-product geochemistry and general aspects of water-rock interaction. The main geochemical studies on this deposit focus on the evolution of groundwater compositions in the deposit and on their redox chemistry with respect to the uranium, iron and sulphide systems. Since 1984, through cooperation from the owners of the Cigar Lake deposit, analog studies have been conducted. AECL, with support from Ontario Hydro under the auspices of the CANDU Owners Group, initiated international participation in 1989 through collaboration with the Swedish Nuclear Fuel and Waste Management Company (SKB) and, more recently, with the Los Alamos National Laboratory (LANL). This report gives the results of the various studies carried out during the 3-year collaboration between AECL and SKB, as well as a summery of the LANL study. It provides detailed information on the generated databases and models, and integrates this information into conclusions for use in safety

  10. Synthesis and structure-distribution study of radioiodinated norepinephrine storage analogs

    Energy Technology Data Exchange (ETDEWEB)

    Wieland, D.M.; Inbasekaran, M.; Brown, L.E.; Marsh, D.D.; Beierwaltes, W.H. (Michigan Univ., Ann Arbor (USA). Medical Center)

    Unlabelled analogs of norepinephrine have been synthesised and then labelled with /sup 125/I in an attempt to find an agent with heart uptake and neuronal specificity greater than metaiodobenzylguanidine (MIBG). The analogs of norepinephrine were injected intravenously into dogs and showed a heart concentration similar to MIBG. Neuronal specificity of some analogs is being evaluated in rat heart.

  11. Synthesis and structure-distribution study of radioiodinated norepinephrine storage analogs

    International Nuclear Information System (INIS)

    Wieland, D.M.; Inbasekaran, M.; Brown, L.E.; Marsh, D.D.; Beierwaltes, W.H.

    1982-01-01

    Unlabelled analogs of norepinephrine have been synthesised and then labelled with 125 I in an attempt to find an agent with heart uptake and neuronal specificity greater than metaiodobenzylguanidine (MIBG). The analogs of norepinephrine were injected intravenously into dogs and showed a heart concentration similar to MIBG. Neuronal specificity of some analogs is being evaluated in rat heart. (U.K.)

  12. Archaeological analogous and industrials for deep storage: study of the archaeological metallic piece

    International Nuclear Information System (INIS)

    Criado Portal, A. J.; Martinez Garcia, J. A.; Calabres Molina, R.; Garcia abajo, A.; Penco Valenzuela, F.; Lecanda Esteban, J. A.; Garcia Bartual, M.; Jimenez Gonzalez, J. M.; Bravo Munoz, E.; Rodriguez Lobo, L. M.; Fernandez Cascos, T.; Fernandes Cordero, O.; Montero Ruiz, I.

    2000-01-01

    The aim of present research is to obtain information about archaeological analogous of iron and steel, useful for the model of deep geological repository (AGP). The analogous examined have remained buried between 1400 and 2400 years, in very assorted geochemical environments. The extraction of the archaeological pieces has been accomplished according to normalised protocols, trying to carry to the laboratory so the piece as its burial environment, avoiding all possible pollution. Trying to the archaeological analogous could provide valuable information to the AGP model, the study has been directed to related the physical-chemical characteristics of the terrain respect to the deterioration of the archaeological metallic piece. The geology of the surrounding terrain to the archaeological deposit, the geomorphological study of the terrain and data from the analysis of ground: pH, wetness, porosity, organic matter contents, bacteria presence, sulphates, carbonates, chlorides, etc., have allowed to explain the physical-chemical phenomena suffered by the archaeological iron and steel pieces. Also, an exhaustive study of the archaeological piece has been accomplished, concerning the microstructure of the corrosion layer and of the not deteriorated metallic rest. Obtained information concerns different items, such as corrosion velocity and formations of oxide layers, diffusion of chemical elements from the corrosion layer to the metal and viceversa, and structural changes in oxide layers and in the metallic remains by structural ageing. Obtained data have allowed to develop a mathematical model for calculation of corrosion velocity in buried iron and steels, based on physical-chemical variables of grounds, chemical composition and thermomechanical treatment given to the metal during its manufacture. (Author)

  13. Natural analog study of engineered protective barriers at the Hanford Site

    International Nuclear Information System (INIS)

    Bjornstad, B.N.; Teel, S.S.

    1993-09-01

    The purpose of this study is to evaluate surficial sedimentary deposits formed in the Pasco Basin over the geologic past as analogs for engineered protective barriers. Evidence for likely changes to be expected in an engineered barrier are preserved in geologically recent deposits. Although the design life of the engineered bonier is only 1,000 years, soils and sediments of this age are uncommon in the Pasco Basin. The evidence of and probability for the following natural processes that could adversely affect the long-term stability of an engineered protective barrier reviewed in this report are deflation by wind, soil compaction, soil eluviation/illuviation, bioturbation, and cryoturbation

  14. Study of an analog/logic processor for the design of an auto patch hybrid computer

    International Nuclear Information System (INIS)

    Koched, Hassen

    1976-01-01

    This paper presents the experimental study of an analog multiprocessor designed at SES/CEN-Saclay. An application of such a device as a basic component of an auto-patch hybrid computer is presented. First, the description of the processor, and a presentation of the theoretical concepts which governed the design of the processor are given. Experiments on an hybrid computer are then presented. Finally, different systems of automatic patching are presented, and conveniently modified, for the use of such a processor. (author) [fr

  15. Analog computing

    CERN Document Server

    Ulmann, Bernd

    2013-01-01

    This book is a comprehensive introduction to analog computing. As most textbooks about this powerful computing paradigm date back to the 1960s and 1970s, it fills a void and forges a bridge from the early days of analog computing to future applications. The idea of analog computing is not new. In fact, this computing paradigm is nearly forgotten, although it offers a path to both high-speed and low-power computing, which are in even more demand now than they were back in the heyday of electronic analog computers.

  16. Activities and results of the terrestrial effects program: acid precipitation in Ontario study (Apios)

    Energy Technology Data Exchange (ETDEWEB)

    Linzon, S N

    1986-11-01

    Studies on the terrestrial effects of acidic precipitation in Ontario involve determining the effects on soils, crops, forests, lichens, mosses and biogeochemical systems. In the soils program, a baseline study was started in 1980 to establish a reliable and uniform data base for soils across the province, in order to identify future trends. Soil sensitivity criteria are being derived for mapping purposes. Starting in 1982, a complex, sophisticated mobile rain exclusion canopy system was constructed outdoors for controlled acid rain studies to determine the dose-response relationships of field crops. In response to numerous complaints a program was designed to determine the role that acidic precipitation is playing in the decline of sugar maple trees in Ontario. At 8 sites, tree conditions were noted, samples of foliage, bark, roots and soil were collected for chemical analysis, and increment cores and discs (from felled trees) were taken for radial growth patterns. Results from this study indicated that acidic precipitation was an additional stress to insect outbreaks and spring droughts. Intensive surveys have been conducted in selected areas in Ontario to identify the current viability and distribution of common denominator lichens and mosses. Biogeochemical studies are being conducted at four watersheds in Ontario. The different watersheds are located in progressively decreasing atmospheric deposition loadings from east to west across the province. The studies are attempting to document the role of contrasting terrestrial ecosystems in the process of lake acidification by atmospheric deposition. 9 references.

  17. Isotopic studies of rare gases in terrestrial samples and in natural nucleosynthesis

    International Nuclear Information System (INIS)

    Reynolds, J.H.

    1988-08-01

    This project is concerned with research in rare gas mass spectrometry. The broad objective is to read the natural record that isotopes of the rare gases comprise as trace constituents of natural gases, rocks, and meteorites. In past years, these interests have led to the study of such diverse problems as the dating of rocks, the early chronology and isotopic structure of the solar system as revealed by extinct radioactivities, and the elemental and isotopic composition of trapped primordial rare gases in meteorites. In recent years, the project has focused progressively more on terrestrial problems

  18. Isotopic studies of rare gases in terrestrial samples and in natural nucleosynthesis

    International Nuclear Information System (INIS)

    1987-07-01

    This project is concerned with research in rare gas mass spectrometry. The broad objective is to read the natural record that isotopes of the rare gases comprise as trace constituents of natural gases, rocks, and meteorites. In past years, these interests have led to the study of such diverse problems as the dating of rocks, the early chronology and isotopic structure of the solar system as revealed by extinct radioactivities, and the elemental and isotopic composition of trapped primordial rare gases in meteorites. In recent years, the project has focused progressively more on terrestrial problems

  19. Detecting analogies unconsciously

    Directory of Open Access Journals (Sweden)

    Thomas Peter Reber

    2014-01-01

    Full Text Available Analogies may arise from the conscious detection of similarities between a present and a past situation. In this functional magnetic resonance imaging study, we tested whether young volunteers would detect analogies unconsciously between a current supraliminal (visible and a past subliminal (invisible situation. The subliminal encoding of the past situation precludes awareness of analogy detection in the current situation. First, participants encoded subliminal pairs of unrelated words in either one or nine encoding trials. Later, they judged the semantic fit of supraliminally presented new words that either retained a previously encoded semantic relation (‘analog’ or not (‘broken analog’. Words in analogs versus broken analogs were judged closer semantically, which reflects unconscious analogy detection. Hippocampal activity associated with subliminal encoding correlated with the behavioral measure of unconscious analogy detection. Analogs versus broken analogs were processed with reduced prefrontal but enhanced medial temporal activity. We conclude that analogous episodes can be detected even unconsciously drawing on the episodic memory network.

  20. Reasoning by analogy: rational foundation of natural analogue studies. [Application to radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Petit, J.-C. (CEA Centre d' Etudes Nucleaires de Fontenay-aux Roses, (France). DRDD/SESD)

    1992-01-01

    Long-term extrapolations concerning the safety of a nuclear waste repository cannot be satisfactorily made on the sole basis of short-term laboratory investigations. Most nuclear countries have hence developed an approach relying on the following research directions: 1. laboratory experiments; 2. in situ testing; 3. modeling; and 4. natural analogues, which are the only means by which very slow mechanisms can be identified and by which long-term predictions of models can be tested for pertinence (if not truly validated). Although the field of natural analogues has grown very rapidly in recent years, receiving support from varied specialists and institutions involved in radioactive waste disposal, there is not yet a full consensus on their actual usefulness. More problematic is the criticism sometimes made that analogical reasoning is not ''true science'' and that information retrieved from the study of natural analogues will always remain questionable. The present paper gives some clues about the exact status of reasoning by analogy, compared to more ''scientific'' ways of deriving information from investigated systems. It is not a thorough discussion of this very complex, and by far too philosophical issue but we hope, at least, to present to readers of papers devoted to natural analogue studies arguments showing that this approach has some sound foundation. (author).

  1. Potentiometric and NMR complexation studies of phenylboronic acid PBA and its aminophosphonate analog with selected catecholamines

    Science.gov (United States)

    Ptak, Tomasz; Młynarz, Piotr; Dobosz, Agnieszka; Rydzewska, Agata; Prokopowicz, Monika

    2013-05-01

    Boronic acids are a class of intensively explored compounds, which according to their specific properties have been intensively explored in last decades. Among them phenylboronic acids and their derivatives are most frequently examined as receptors for diverse carbohydrates. In turn, there is a large gap in basic research concerning complexation of catecholamines by these compounds. Therefore, we decided to undertake studies on interaction of chosen catecholamines, namely: noradrenaline (norephinephrine), dopamine, L-DOPA, DOPA-P (phosphonic analog of L-DOPA) and catechol, with simple phenyl boronic acid PBA by means of potentiometry and NMR spectroscopy. For comparison, the binding properties of recently synthesized phenylboronic receptor 1 bearing aminophosphonate function in meta-position were investigated and showed promising ability to bind catecholamines. The protonation and stability constants of PBA and receptor 1 complexes were examined by potentiometry. The obtained results demonstrated that PBA binds the catecholamines with the following affinity order: noradrenaline ⩾ dopamine ≈ L-DOPA > catechol > DOPA-P, while its modified analog 1 reveals slightly different preferences: dopamine > noradrenaline > catechol > L-DOPA > DOPA-P.

  2. Synthesis of piperazine sulfonamide analogs as diabetic-II inhibitors and their molecular docking study.

    Science.gov (United States)

    Taha, Muhammad; Irshad, Maryam; Imran, Syahrul; Chigurupati, Sridevi; Selvaraj, Manikandan; Rahim, Fazal; Ismail, Nor Hadiani; Nawaz, Faisal; Khan, Khalid Mohammed

    2017-12-01

    Piperazine Sulfonamide analogs (1-19) have been synthesized, characterized by different spectroscopic techniques and evaluated for α-amylase Inhibition. Analogs 1-19 exhibited a varying degree of α-amylase inhibitory activity with IC 50 values ranging in between 1.571 ± 0.05 to 3.98 ± 0.397 μM when compared with the standard acarbose (IC 50  = 1.353 ± 0.232 μM). Compound 1, 2, 3 and 7 showed significant inhibitory effects with IC 50 value 2.348 ± 0.444, 2.064 ± 0.04, 1.571 ± 0.05 and 2.118 ± 0.204 μM, respectively better than the rest of the series. Structure activity relationships were established. Molecular docking studies were performed to understand the binding interaction of the compounds. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Study for material analogs of FeSb2: Material design for thermoelectric materials

    Science.gov (United States)

    Kang, Chang-Jong; Kotliar, Gabriel

    2018-03-01

    Using the ab initio evolutionary algorithm (implemented in uspex) and electronic structure calculations we investigate the properties of a new thermoelectric material FeSbAs, which is a material analog of the enigmatic thermoelectric FeSb2. We utilize the density functional theory and the Gutzwiller method to check the energetics. We find that FeSbAs can be made thermodynamically stable above ˜30 GPa. We investigate the electronic structure and thermoelectric properties of FeSbAs based on the density functional theory and compare with those of FeSb2. Above 50 K, FeSbAs has higher Seebeck coefficients than FeSb2. Upon doping, the figure of merit becomes larger for FeSbAs than for FeSb2. Another material analog FeSbP, was also investigated, and found thermodynamically unstable even at very high pressure. Regarding FeSb2 as a member of a family of compounds (FeSb2, FeSbAs, and FeSbP) we elucidate what are the chemical handles that control the gaps in this series. We also investigate solubility (As or P for Sb in FeSb2) we found As to be more soluble. Finally, we study a two-band model for thermoelectric properties and find that the temperature dependent chemical potential and the presence of the ionized impurities are important to explain the extremum in the Seebeck coefficient exhibited in experiments for FeSb2.

  4. Experimental study of interfacial shear stress for an analogy model of evaporative heat transfer

    International Nuclear Information System (INIS)

    Kwon, Hyuk; Park, GoonCherl; Min, ByungJoo

    2008-01-01

    In this study, we conducted measurements of an evaporative interfacial shear stress in a passive containment cooling system (PCCS). An interfacial shear stress for a counter-current flow was measured from a momentum balance equation and the interfacial friction factor for evaporation was evaluated by using experimental data. A model for the evaporative heat transfer coefficient of a vertical evaporative flat surface was developed based on an analogy between heat and momentum transfer. It was found that the interfacial shear stress increases with the Jacob number, which incorporates the evaporation rate, and the air and water Reynolds numbers. The relationship between the evaporative heat transfer and the interfacial shear stress was evaluated by using the experimental results. This relationship was used to develop a model for an evaporative heat transfer coefficient by using an analogy between heat and mass transfer. The prediction of this model were found to be in good agreement with the experimental data obtained for evaporative heat transfer by Kang and Park. (author)

  5. Spatial and temporal characteristics of poloidal waves in the terrestrial plasmasphere: a CLUSTER case study

    Directory of Open Access Journals (Sweden)

    S. Schäfer

    2007-05-01

    Full Text Available Oscillating magnetic field lines are frequently observed by spacecraft in the terrestrial and other planetary magnetospheres. The CLUSTER mission is a very suitable tool to further study these Alfvén waves as the four CLUSTER spacecraft provide for an opportunity to separate spatial and temporal structures in the terrestrial magnetosphere. Using a large scaled configuration formed by the four spacecraft we are able to detect a poloidal Ultra-Low-Frequency (ULF pulsation of the magnetic and electric field in order to analyze its temporal and spatial structures. For this purpose the measurements are transformed into a specific field line related coordinate system to investigate their specific amplitude pattern depending on the path of the CLUSTER spacecraft across oscillating field lines. These measurements are then compared with modeled spacecraft observations across a localized poloidal wave resonator in the dayside plasmasphere. A detailed investigation of theoretically expected poloidal eigenfrequencies allows us to specify the observed 16 mHz pulsation as a third harmonic oscillation. Based on this we perform a case study providing a clear identification of wave properties such as an spatial scale structure of about 0.67 RE, the azimuthal wave number m≈30, temporal evolution, and energy transport in the detected ULF pulsations.

  6. Bioprinting of Micro-Organ Tissue Analog for Drug Metabolism Study

    Science.gov (United States)

    Sun, Wei

    An evolving application of tissue engineering is to develop in vitro 3D cell/tissue models for drug screening and pharmacological study. In order to test in space, these in vitro models are mostly manufactured through micro-fabrication techniques and incorporate living cells with MEMS or microfluidic devices. These cell-integrated microfluidic devices, or referred as microorgans, are effective in furnishing reliable and inexpensive drug metabolism and toxicity studies [1-3]. This paper will present an on-going research collaborated between Drexel University and NASA JSC Radiation Physics Laboratory for applying a direct cell printing technique to freeform fabrication of 3D liver tissue analog in drug metabolism study. The paper will discuss modeling, design, and solid freeform fabrication of micro-fluidic flow patterns and bioprinting of 3D micro-liver chamber that biomimics liver physiological microenvironment for enhanced drug metabolization. Technical details to address bioprinting of 3D liver tissue analog, integration with a microfluidic device, and basic drug metabolism study for NASA's interests will presented. 1. Holtorf H. Leslie J. Chang R, Nam J, Culbertson C, Sun W, Gonda S, "Development of a Three-Dimensional Tissue-on-a-Chip Micro-Organ Device for Pharmacokinetic Analysis", the 47th Annual Meeting of the American Society for Cell Biology, Washington, DC, December 1-5, 2007. 2. Chang, R., Nam, J., Culbertson C., Holtorf, H., Jeevarajan, A., Gonda, S. and Sun, W., "Bio-printing and Modeling of Flow Patterns for Cell Encapsulated 3D Liver Chambers For Pharmacokinetic Study", TERMIS North America 2007 Conference and Exposition, Westin Harbour Castle, Toronto, Canada, June 13-16, 2007. 3.Starly, B., Chang, R., Sun, W., Culbertson, C., Holtorf, H. and Gonda, S., "Bioprinted Tissue-on-chip Application for Pharmacokinetic Studies", Proceedings of World Congress on Tissue Engineering and Regenerative Medicine, Pittsburgh, PA, USA, April 24-27, 2006.

  7. Remembering Places in Space: A Human Analog Study of the Morris Water Maze

    Science.gov (United States)

    Fitting, Sylvia; Allen, Gary L.; Wedell, Douglas H.

    We conducted a human analog study of the Morris Water Maze, with individuals indicating a remembered location in a 3 m diameter arena over different intervals of time and with different memory loads. The primary focus of the study was to test a theory of how varying cue location and number of cues affects memory for spatial location. As expected, memory performance, as measured by proximity to the actual location, was negatively affected by increasing memory load, increasing delay interval, and decreasing the number of cues. As memory performance decremented, bias effects increased and were in accordance with the cue-based memory model described by Fitting, Wedell and Allen (2005). Specifically, remembered locations were biased toward the nearest cue and error decreased with more cues. These results demonstrate that localization processes that apply to small two-dimensional task fields may generalize to a larger traversable task field.

  8. Final report of the AECL/SKB Cigar Lake analog study

    International Nuclear Information System (INIS)

    Cramer, J.J.

    1994-07-01

    The Cigar Lake uranium deposit is located in northern Saskatchewan, Canada. The 1.3-billion-year-old deposit is located at a depth of about 450 m below surface in a water-saturated sandstone at the unconformity contact with the high-grade metamorphic rocks of the Canadian Shield. The uranium mineralization, consisting primarily of uraninite (UO 2 ), is surrounded by a clay-rich halo in both sandstone and basement rocks, and remains extremely well preserved and intact. The average grade of the mineralization is ∼ 8 wt.% U; locally grades are as high as ∼ 55 wt.%U. The Cigar lake deposit has many features that parallel those being considered within the Canadian concept for disposal of nuclear fuel waste. Specifically, the deposit provides analog information relevant to the stability of UO 2 fuel waste, the performance of clay-based barriers, radionuclide migration, colloid formation, radiolysis, fission-product geochemistry and general aspects of water-rock interaction. The main geochemical studies on this deposit focus on the evolution of groundwater compositions in the deposit and on their redox chemistry with respect to the uranium, iron and sulphide systems. Since 1984, through cooperation from the owners of the Cigar lake deposit, analog studies have been conducted. AECL, with support from Ontario Hydro under the auspices of the CANDU Owners Group, initiated international participation in 1989 through collaboration with the Swedish Nuclear Fuel and Waste Management Company (SKB) and, more recently, with the Los Alamos National Laboratory (LANL). This report gives the results of the various studies carried out during the 3-year collaboration between AECL and SKB, as well as a summary of the LANL study. It provides detailed information on the generated databases and models, and integrates this information into conclusions for use in safety assessment of the Canadian, Swedish and United States disposal concepts. 15 refs., 25 figs., 55 tabs

  9. Bed Rest is an Analog to Study the Physiological Changes of Spaceflight and to Evaluate Countermeasures

    Science.gov (United States)

    Pfannenstiel, P.; Ottenbacher, M.; Inniss, A.; Ware, D.; Anderson, K.; Stranges, S.; Keith, K.; Cromwell, R.; Neigut. J.; Powell, D.

    2012-01-01

    The UTMB/NASA Flight Analog Research Unit is an inpatient unit with a bionutrition kitchen and unique testing areas for studying subjects subjected to 6 degree head-down complete bed rest for prolonged periods as an analog for zero gravity. Bed rest allows study of physiological changes and performance of functional tasks representative of critical interplanetary mission operations and measures of the efficacy of countermeasures designed to protect against the resulting deleterious effects. METHODS/STUDY POPULATION: Subjects are healthy adults 24-55 years old; 60 75 in tall; body mass index 18.5-30; and bone mineral density normal by DXA scan. Over 100 subjects have been studied in 7 campaigns since 2004. The iRAT countermeasure combines high intensity interval aerobic exercises on alternating days with continuous aerobic exercise. Resistance exercise is performed 3 days per week. Subjects are tested on an integrated suite of functional and interdisciplinary physiological tests before and after 70 days of total bed rest. RESULTS/ANTICIPATED RESULTS: It is anticipated that post-bed rest functional performance will be predicted by a weighted combination of sensorimotor, cardiovascular and muscle physiological factors. Control subjects who do not participate in the exercise countermeasure will have significantly greater decreases in these parameters. DISCUSSION/SIGNIFICANCE OF IMPACT: Astronauts experience alterations in multiple physiological systems due to exposure to the microgravity, leading to disruption in the ability to perform functional tasks after reintroduction to a gravitational environment. Current flight exercise countermeasures are not fully protective of cardiovascular, muscle and bone health. There is a need to refine and optimize countermeasures to mitigate health risks associated with long-term space missions.

  10. A study of analog-to digital sliding scale. Converter utilization

    Energy Technology Data Exchange (ETDEWEB)

    Maddaleno, F; Rossi, M

    1996-12-31

    The well-known Sliding Scale technique provides a statistical linearization of the Analog to Digital Converter, obtaining a high differential linearity. This technique sums at each conversion a known and uncorrelated variable signal (offset) to the analog input signal, and then subs tract numerically the offset from the conversion result. 2 refs.

  11. Neutron-skin thickness from the study of the anti-analog giant dipole resonance

    NARCIS (Netherlands)

    Krasznahorkay, A.; Stuhl, L.; Csatlós, M.; Algora, A.; Gulyás, J.; Timár, J.; Paar, N.; Vretenar, D.; Boretzky, K.; Heil, M.; Litvinov, Yu A.; Rossi, D.; Scheidenberger, C.; Simon, H.; Weick, H.; Bracco, A.; Brambilla, S.; Blasi, N.; Camera, F.; Giaz, A.; Million, B.; Pellegri, L.; Riboldi, S.; Wieland, O.; Altstadt, S.; Fonseca, M.; Glorius, J.; Göbel, K.; Heftrich, T.; Koloczek, A.; Kräckmann, S.; Langer, C.; Plag, R.; Pohl, M.; Rastrepina, G.; Reifarth, R.; Schmidt, S.; Sonnabend, K.; Weigand, M.; Harakeh, M. N.; Kalantar-Nayestanaki, N.; Rigollet, C.; Bagchi, S.; Najafi, M. A.; Aumann, T.; Atar, L.; Heine, M.; Holl, M.; Movsesyan, A.; Schrock, P.; Volkov, V.; Wamers, F.; Fiori, E.; Löher, B.; Marganiec, J.; Savran, D.; Johansson, H. T.; Fernández, P. Diaz; Garg, U.; Balabanski, D. L.

    2012-01-01

    The gamma-decay of the anti-analog of the giant dipole resonance (AGDR) has been measured to the isobaric analog state excited in the p(124Sn,n) reaction at a beam energy of 600 MeV/nucleon. The energy of the transition was also calculated with state-of-the-art self-consistent random-phase

  12. The analogy research study on gamma radiation dose rate of radioisotopes 131Ba and 131I

    International Nuclear Information System (INIS)

    Hu Youhua; Feng Guangwen

    2013-01-01

    Analogy is a inference method ,according some properties of a class of things to inferring the similar things should also have the similar properties. The analogy of same radionuclides is widely used in radioisotope logging environment impact assessment so far. This paper is to provide fFor future providing a theoretical calculation method and analogy method between different radionuclides in radioisotope logging environment impact assessment. In this paper, using the latest decay scheme, through theoretical modeling, the aim is the the establishment of 131 Ba and 131 I radioisotopes gamma radiation dose rate calculation method, and try to carry out analogy research on gamma radiation dose rate of different radioisotopes with the same activity. The results show that the analogy of different radionuclides is feasible, which provides the new method reference for carrying out such radiation environmental impact assessment in future. (authors)

  13. A comparative study on fluorescent cholesterol analogs as versatile cellular reporters

    DEFF Research Database (Denmark)

    Sezgin, Erdinc; Betul Can, Fatma; Schneider, Falk

    2016-01-01

    Cholesterol is a crucial component of cellular membranes, but knowledge of its intracellular dynamics is scarce. Thus, it is of utmost interest to develop tools for visualization of cholesterol organization and dynamics in cells and tissues. For this purpose, many studies make use of fluorescently...... for their performance in cellular assays: 1) plasma membrane incorporation, specifically the preference for more ordered membrane environments in phase separated giant unilamellar vesicles (GUVs) and giant plasma membrane vesicles (GPMVs); 2) cellular trafficking, specifically subcellular localization in Niemann-Pick C...... in the intracellular trafficking assay. However, none showed positive performance in all assays. Our results constitute a concise guide for the careful use of fluorescent cholesterol analogs in visualizing cellular cholesterol dynamics....

  14. Study of the interaction of the rupture zones of contiguous anchor plates in analogical medium

    Directory of Open Access Journals (Sweden)

    Abbad H.

    2018-01-01

    Full Text Available Knowing what occurs above anchor plates is certainly instructive. In this general vision of the interaction soil-anchor plates that our work was directed. An experimental study which required the design and implantation of a model containing plastic granules powder to similate a natural environment, is presented. The latter is subjected to the removal of anchor paltes. For each test, digital photographs are taken to materialize different deformed configurations during the pullout process. These photos processed in couples by the 7D software (image correlation giving the evolution of the displacement field and plane strain analogical environment. Particular attention is paid to the discussion of the interference of rupture zones of contiguous anchors by reducing the distance between plates.

  15. Optical analogy. Synthesis report

    International Nuclear Information System (INIS)

    1965-01-01

    The authors report the study of conditions under which light attenuation (reflection, diffusion, absorption) and the attenuation of some radiations (notably thermal neutrons) can be described with analogical calculations. The analogy between light physical properties and neutron properties is not searched for, but the analogy between their attenuation characteristics. After having discussed this possible analogy, they propose a mathematical formulation of neutron and optical phenomena which could theoretically justify the optical analogy. The second part reports a more practical study of optics problems such as the study of simple optics materials and illumination measurements, or more precisely the study of angular distributions of optical reflections, a determination of such angular distributions, and an experimental determination of the albedo

  16. Tribulus terrestris versus placebo in the treatment of erectile dysfunction: A prospective, randomized, double blind study.

    Science.gov (United States)

    Santos, C A; Reis, L O; Destro-Saade, R; Luiza-Reis, A; Fregonesi, A

    2014-05-01

    To evaluate the possible effects of Tribulus terrestris herbal medicine in the erectile dysfunction treatment and to quantify its potential impact on serum testosterone levels. Prospective, randomized, double-blind and placebo-controlled study including thirty healthy men selected from 100 patients who presented themselves spontaneously complaining of erectile dysfunction, ≥ 40 years of age, nonsmokers, not undergoing treatment for prostate cancer or erectile dysfunction, no dyslipidemia, no phosphodiesterase inhibitor use, no hormonal manipulation and, if present hypertension and/or diabetes mellitus should be controlled. International Index of Erectile Function (IIEF-5) and serum testosterone were obtained before randomization and after 30 days of study. Patients were randomized into two groups of fifteen subjects each. The study group received 800 mg of Tribulus terrestris, divided into two doses per day for thirty days and the control group received placebo administered in the same way. The groups were statistically equivalent in all aspects evaluated. The mean (SD) age was 60 (9.4) and 62.9 (7.9), P = .36 for intervention and placebo groups, respectively. Before treatment, the intervention group showed mean IIEF-5 of 13.2 (5-21) and mean total testosterone 417.1 ng/dl (270.7-548.4 ng/dl); the placebo group showed mean IIEF-5 of 11.6 (6-21) and mean total testosterone 442.7 ng/dl (301-609.1 ng/dl). After treatment, the intervention group showed mean IIEF-5 of 15.3 (5-21) and mean total testosterone 409.3 ng/dl (216.9-760.8 ng/dl); the placebo group showed mean IIEF-5 of 13.7 (6-21) and mean total testosterone 466.3 ng/dl (264.3-934.3 ng/dl). The time factor caused statistically significant changes in both groups for IIEF-5 only (P = .0004), however, there was no difference between the two groups (P = .7914). At the dose and interval studied, Tribulus terrestris was not more effective than placebo on improving symptoms of erectile dysfunction or serum total

  17. Is it time for studying real-life debiasing? Evaluation of the effectiveness of an analogical intervention technique

    Directory of Open Access Journals (Sweden)

    Balazs eAczel

    2015-08-01

    Full Text Available The aim of this study was to initiate the exploration of debiasing methods applicable in real-life settings for achieving lasting improvement in decision-making competence regarding multiple decision biases. Here, we tested the potentials of the analogical encoding method for decision debiasing. The advantage of this method is that it can foster the transfer from learning abstract principles to improving behavioral performance. For the purpose of the study, we devised an analogical debiasing technique for ten biases (covariation detection, insensitivity to sample size, base rate neglect, regression to the mean, outcome bias, sunk cost fallacy, framing effect, anchoring bias, overconfidence bias, planning fallacy and assessed the susceptibility of the participants (N = 154 to these biases before and four weeks after the training. We also compared the effect of the analogical training to the effect of an ‘awareness training’ and a ‘no-training’ control group. Results suggested improved performance of the analogical training group only on tasks where the violations of statistical principles are measured. The interpretation of these findings require further investigation, yet it is possible that analogical training may be the most effective in the case of learning abstract concepts, such as statistical principles, which are otherwise difficult to master. The study encourages a systematic research of debiasing trainings and the development of intervention assessment methods to measure the endurance of behavior change in decision debiasing.

  18. Ethnopharmacological studies of Tribulus terrestris (Linn). in relation to its aphrodisiac properties.

    Science.gov (United States)

    Mathur, Manish; Sundaramoorthy, S

    2012-01-01

    Synergism and antagonism impact of different plant metabolites present in crude fruit extract of Tribulus terrestris 'the herbal Viagra' have been studied. Variability in plant composition, biomass and metabolites concentration in different modules was significantly contributed by spatial factor. However the edhaphic parameters also changes with both spatial and temporal factors significantly. Fruit is the officinal part and the fruit production significantly related with soil nitrogen (P<0.01), whereas the soil nitrogen and pH also influenced the alkaloid content in fruit (P<0.05). The linear relation between fruit protein and fruit alkaloid (P<0.01) also observed and the relationship in between different soil parameters were established. Bioassay work confirmed its aphrodisiac properties, and site III is suggested for maximum biomass and high concentration of different metabolites.

  19. The substitution of the implant and abutment for their analogs in mechanical studies: In vitro and in silico analysis

    International Nuclear Information System (INIS)

    Gomes, Rafael Soares; Bergamo, Edmara Tatiely Pedroso; Bordin, Dimorvan; Del Bel Cury, Altair Antoninha

    2017-01-01

    The use of analogs could reduce the cost of mechanical tests involving implant-supported crowns, but it is unclear if it would negatively affect the data accuracy. This study evaluated the substitution of the implant by implants analogs or abutment analogs as a support for crowns in mechanical tests, taking into account stress distribution and fracture load of monolithic lithium disilicate crowns. Thirty lithium disilicate monolithic crowns were randomized into three groups according to the set: Implant + abutment (IA); implant analog + abutment (IAA); abutment analog (AA). The specimens were subjected to mechanical fatigue (10 6 cycles, 200 N, 2 Hz) and thermal fatigue (10 4 cycles, 5°–55 °C). A final compression load was applied and the maximum fracture load was recorded. Data were analyzed using one-way ANOVA (α = 0.05). The experiment was validated by finite element analysis and the maximum principal stress was recorded. No statistically significant difference was observed in the mean fracture load among groups (P > 0.05). The failure mode was similar for all groups with the origin of crack propagation located at the load point application. Finite element analysis showed similar stress distribution and stress peak values for all groups. The use of implant's or abutment's analog does not influence the fracture load and stress distribution for cemented implant-supported crowns. - Highlights: • A less costly methodology for evaluate implant-supported crowns is proposed. • It is suggested the substitution of the implant or abutment for their analogs. • The outcomes of fracture load are not influenced by these replacements.

  20. The substitution of the implant and abutment for their analogs in mechanical studies: In vitro and in silico analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Rafael Soares; Bergamo, Edmara Tatiely Pedroso; Bordin, Dimorvan; Del Bel Cury, Altair Antoninha, E-mail: altair@unicamp.br

    2017-06-01

    The use of analogs could reduce the cost of mechanical tests involving implant-supported crowns, but it is unclear if it would negatively affect the data accuracy. This study evaluated the substitution of the implant by implants analogs or abutment analogs as a support for crowns in mechanical tests, taking into account stress distribution and fracture load of monolithic lithium disilicate crowns. Thirty lithium disilicate monolithic crowns were randomized into three groups according to the set: Implant + abutment (IA); implant analog + abutment (IAA); abutment analog (AA). The specimens were subjected to mechanical fatigue (10{sup 6} cycles, 200 N, 2 Hz) and thermal fatigue (10{sup 4} cycles, 5°–55 °C). A final compression load was applied and the maximum fracture load was recorded. Data were analyzed using one-way ANOVA (α = 0.05). The experiment was validated by finite element analysis and the maximum principal stress was recorded. No statistically significant difference was observed in the mean fracture load among groups (P > 0.05). The failure mode was similar for all groups with the origin of crack propagation located at the load point application. Finite element analysis showed similar stress distribution and stress peak values for all groups. The use of implant's or abutment's analog does not influence the fracture load and stress distribution for cemented implant-supported crowns. - Highlights: • A less costly methodology for evaluate implant-supported crowns is proposed. • It is suggested the substitution of the implant or abutment for their analogs. • The outcomes of fracture load are not influenced by these replacements.

  1. Controlled dual release study of curcumin and a 4-aminoquinoline analog from gum acacia containing hydrogels

    CSIR Research Space (South Africa)

    Aderibigbe, BA

    2014-10-01

    Full Text Available The potential of gum acacia containing hydrogels as controlled dual-drug delivery systems for antiprotozoal agents was investigated. 4-Aminoquinoline analog and curcumin were selected as model drugs because they exhibit antiprotozoal activity...

  2. Studies towards the synthesis of ATP analogs as potential glutamine synthetase inhibitors

    CSIR Research Space (South Africa)

    Salisu, S

    2011-05-01

    Full Text Available and Centre for Chemico- and Biomedicinal Research, Rhodes University, Grahamstown, South Africa b CSIR BIO/CHEMTEK, Modderfontein, South Africa ABSTRACT In research directed at the development of adenine triphosphate (ATP) analogs as potential...

  3. Analog earthquakes

    International Nuclear Information System (INIS)

    Hofmann, R.B.

    1995-01-01

    Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository

  4. Thermal expansion in 3d-metal Prussian Blue Analogs-A survey study

    International Nuclear Information System (INIS)

    Adak, Sourav; Daemen, Luke L.; Hartl, Monika; Williams, Darrick; Summerhill, Jennifer; Nakotte, Heinz

    2011-01-01

    We present a comprehensive study of the structural properties and the thermal expansion behavior of 17 different Prussian Blue Analogs (PBAs) with compositions M II 3 [(M') III (CN) 6 ] 2 .nH 2 O and M II 2 [Fe II (CN) 6 ].nH 2 O, where M II =Mn, Fe, Co, Ni, Cu and Zn, (M') III =Co, Fe and n is the number of water molecules, which range from 5 to 18 for these compounds. The PBAs were synthesized via standard chemical precipitation methods, and temperature-dependent X-ray diffraction studies were performed in the temperature range between -150 deg. C (123 K) and room-temperature. The vast majority of the studied PBAs were found to crystallize in cubic structures of space groups Fm3-bar m, F4-bar 3m and Pm3-bar m. The temperature dependence of the lattice parameters was taken to compute an average coefficient of linear thermal expansion in the studied temperature range. Of the 17 compounds, 9 display negative values for the average coefficient of linear thermal expansion, which can be as large as 39.7x 1 0 -6 K -1 for Co 3 [Co(CN) 6 ] 2 .12H 2 O. All of the M II 3 [Co III (CN) 6 ] 2 .nH 2 O compounds show negative thermal expansion behavior, which correlates with the Irving-Williams series for metal complex stability. The thermal expansion behavior for the PBAs of the M II 3 [Fe III (CN) 6 ] 2 .nH 2 O family are found to switch between positive (for M=Mn, Co, Ni) and negative (M=Cu, Zn) behavior, depending on the choice of the metal cation (M). On the other hand, all of the M II 2 [Fe II (CN) 6 ].nH 2 O compounds show positive thermal expansion behavior. - Graphical Abstract: The structure of Prussian Blue analogs (PBAs) consists of two types of metal centered octahedral units connected by cyanide ligand. Lattice and interstitial water molecules are present in these framework structures. All the PBAs of the M 3 [Co(CN) 6 ] 2 .nH 2 O family show negative thermal expansion (NTE) behavior. The lattice parameters and magnitude of NTE correlates inversely with the Irving

  5. Studies of chaos and thermal noise in a driven Josephson junction using an electronic analog

    International Nuclear Information System (INIS)

    Pegrum, C.M.; Gurney, W.S.C.; Nisbet, R.M.

    1989-01-01

    Using an electronic analog of a resistively shunted driven Josephson junction, the authors have demonstrated a number of effects, including the appearance of a devil's staircase in the current-voltage characteristic, the onset of chaos, and the effect of noise on these phenomena. The authors stress that the analog is simple, but models the junction behavior with a high degree of accuracy and detail

  6. Structure-activity studies of vasoactive intestinal peptide (VIP): cyclic disulfide analogs.

    Science.gov (United States)

    Bolin, D R; Cottrell, J; Garippa, R; O'Neill, N; Simko, B; O'Donnell, M

    1993-02-01

    Analogs of vasoactive intestinal peptide with cysteine residues incorporated at selected sites within the sequence were prepared by solid phase methods, oxidized to the corresponding cyclic disulfides and purified to homogeneity by preparative HPLC. The cyclic compounds were assayed as smooth muscle relaxants on isolated guinea pig trachea, as bronchodilators in vivo in guinea pigs, and for binding to VIP receptors in guinea pig lung membranes. Of the analogs prepared at the N-terminus, one compound, Ac-[D-Cys6,D-Cys11,Lys12,Nle17,Val26,Th r28]-VIP, was found to be a full agonist with slightly more than one tenth the potency of native VIP. Most other cyclic analogs in the N-terminal region were found to be inactive. A second analog, Ac-[Lys12,Cys17,Val26,Cys28]-VIP, was also found to be a full agonist with potency about one third that of native VIP. Furthermore, this compound was active as a bronchodilator in vivo in guinea pig, but with somewhat diminished potency as compared to native VIP. Strikingly, this cyclic compound was found to have significantly longer duration of action (> 40 min) when compared to an analogous acyclic compound (5 min). The conformational restrictions imposed by formation of the cyclic ring structures may have stabilized the molecule to degradation, thus enhancing the effective duration of action. Analysis of this series of cyclic analogs has also yielded information about the requirements for the receptor-active conformation of VIP.

  7. Terrestrial ecology

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The main effort of the Terrestrial Ecology Division has been redirected to a comprehensive study of the Espiritu Santo Drainage Basin located in northeastern Puerto Rico. The general objective are to provide baseline ecological data for future environmental assessment studies at the local and regional levels, and to provide through an ecosystem approach data for the development of management alternatives for the wise utilization of energy, water, and land resources. The interrelationships among climate, vegetation, soils, and man, and their combined influence upon the hydrologic cycle will be described and evaluated. Environmental management involves planning and decision making, and both require an adequate data base. At present, little is known about the interworkings of a complete, integrated system such as a drainage basin. A literature survey of the main research areas confirmed that, although many individual ecologically oriented studies have been carried out in a tropical environment, few if any provide the data base required for environmental management. In view of rapidly changing socio-economic conditions and natural resources limitations, management urgently requires data from these systems: physical (climatological), biological, and cultural. This integrated drainage basin study has been designed to provide such data. The scope of this program covers the hydrologic cycle as it is affected by the interactions of the physical, biological, and cultural systems

  8. An evaluation of scanpath-comparison and machine-learning classification algorithms used to study the dynamics of analogy making.

    Science.gov (United States)

    French, Robert M; Glady, Yannick; Thibaut, Jean-Pierre

    2017-08-01

    In recent years, eyetracking has begun to be used to study the dynamics of analogy making. Numerous scanpath-comparison algorithms and machine-learning techniques are available that can be applied to the raw eyetracking data. We show how scanpath-comparison algorithms, combined with multidimensional scaling and a classification algorithm, can be used to resolve an outstanding question in analogy making-namely, whether or not children's and adults' strategies in solving analogy problems are different. (They are.) We show which of these scanpath-comparison algorithms is best suited to the kinds of analogy problems that have formed the basis of much analogy-making research over the years. Furthermore, we use machine-learning classification algorithms to examine the item-to-item saccade vectors making up these scanpaths. We show which of these algorithms best predicts, from very early on in a trial, on the basis of the frequency of various item-to-item saccades, whether a child or an adult is doing the problem. This type of analysis can also be used to predict, on the basis of the item-to-item saccade dynamics in the first third of a trial, whether or not a problem will be solved correctly.

  9. Hole Burning Imaging Studies of Cancerous and Analogous Normal Ovarian Tissues Utilizing Organelle Specific Dyes

    Energy Technology Data Exchange (ETDEWEB)

    Matsuzaki, Satoshi [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    Presented in this dissertation is the successful demonstration that nonphotochemical hole burning (NPWB) imaging can be used to study in vitro tissue cellular systems for discerning differences in cellular ultrastructures due to cancer development. This has been accomplished with the surgically removed cancerous ovarian and analogous normal peritoneal tissues from the same patient and the application of a fluorescent mitochondrion specific dye, Molecular Probe MitoFluor Far Red 680 (MF680), commonly known as rhodamine 800, that has been proven to exhibit efficient NPHB. From the results presented in Chapters 4 and 5 , and Appendix B, the following conclusions were made: (1) fluorescence excitation spectra of MF680 and confocal microscopy images of thin sliced tissues incubated with MF680 confirm the site-specificity of the probe molecules in the cellular systems. (2) Tunneling parameters, {lambda}{sub 0} and σΛ, as well as the standard hole burning parameters (namely, γ and S), have been determined for the tissue samples by hole growth kinetics (HGK) analyses. Unlike the preliminary cultured cell studies, these parameters have not shown the ability to distinguish tissue cellular matrices surrounding the chromophores. (3) Effects of an external electric (Stark) field on the nonphotochemical holes have been used to determine the changes in permanent dipole moment (fΔμ) for MF680 in tissue samples when burn laser polarization is parallel to the Stark field. Differences are detected between fΔμs in the two tissue samples, with the cancerous tissue exhibiting a more pronounced change (1.35-fold increase) in permanent dipole moment change relative to the normal analogs. It is speculated that the difference may be related to differences in mitochondrial membrane potentials in these tissue samples. (4) In the HGK mode, hole burning imaging (HBI) of cells adhered to coverslips and cooled to liquid helium temperatures in the complete absence of

  10. Adaptation of the landscape for biodiversity to climate change : terrestrial case studies Limburg (NL), Kent and Hampshire (UK)

    NARCIS (Netherlands)

    Rooij, van S.A.M.; Baveco, J.M.; Bugter, R.J.F.; Eupen, van M.; Opdam, P.F.M.; Steingröver, E.G.; Taylor, S.; Steenwijk, van H.

    2007-01-01

    This study is part of the BRANCH project, aimed at assessing the impact of climate change on species and habitats and formulating strategies for adaptation. It focuses on the local scale in three terrestrial case studies, Limburg (NL) and in Kent and Hampshire (UK). We developed and tested: (a) a

  11. Stereoselective synthesis of an iodinated resveratrol analog: Preliminary bioevaluation studies of the radioiodinated species

    Energy Technology Data Exchange (ETDEWEB)

    Dhyani, Manish V.; Kameswaran, Mythili; Korde, Aruna G.; Pandey, Usha [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Chattopadhyay, Subrata [Bio-Organic Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Banerjee, Sharmila, E-mail: sharmila@barc.gov.i [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2011-07-15

    Stereoselective synthesis of an E-hydroxystilbene has been carried out using the McMurry reaction. Synthesis of a monoiodinated hydroxystilbene has been carried out by a McMurry cross-coupling reaction. For the purpose of biological evaluation, the facile electrophilic substitution route has been attempted to radioiodinate it with {sup 125}I. The HPLC pattern of the radioiodinated hydroxystilbene, which could be obtained in >90% radiochemical purity, was found to be identical to that of its non-radioactive analog that has been independently prepared using the McMurry cross-coupling route. In vitro cell uptake studies were carried out in breast cancer cells MCF7, overexpressing estrogen receptors. In vivo biodistribution studies in female Swiss mice show a uterine uptake of 0.85{+-}0.4% ID/g at 3 h.p.i. with a uterus to muscle ratio of 2.83. Uptake in the thyroid was insignificant indicating good in vivo stability of the radioiodinated hydroxystilbene.

  12. 3D QSAR Studies of DAMNI Analogs as Possible Non-nucleoside Reverse Transcriptase Inhibitors

    Directory of Open Access Journals (Sweden)

    S. Ganguly

    2008-01-01

    Full Text Available The non-nucleoside inhibitors of HIV-1-reverse transcriptase (NNRTIs are an important class of drugs employed in antiviral therapy. Recently, a novel family of NNRTIs commonly referred to as 1-[2-diarylmethoxy] ethyl 2-methyl-5-nitroimidazoles (DAMNI derivatives have been discovered. The 3D-QSAR studies on DAMNI derivatives as NNRTIs was performed by comparative molecular field analysis (CoMFA and comparative molecular similarity indices analysis (CoMSIA methods to determine the factors required for the activity of these compounds. The global minimum energy conformer of the template molecule 15, the most active molecule of the series, was obtained by simulated annealing method and used to build the structures of the molecules in the dataset. The combination of steric and electrostatic fields in CoMSIA gave the best results with cross-validated and conventional correlation coefficients of 0.654 and 0.928 respectively. The predictive ability of CoMFA and CoMSIA were determined using a test set of ten DAMNI derivatives giving predictive correlation coefficients of 0.92 and 0.98 respectively indicating good predictive power. Further, the robustness of the models was verified by bootstrapping analysis. The information obtained from CoMFA and CoMSIA 3D contour maps may be of utility in the design of more potent DAMNI analogs as NNRTIs in future.

  13. Synthesis, β-glucuronidase inhibition and molecular docking studies of hybrid bisindole-thiosemicarbazides analogs.

    Science.gov (United States)

    Taha, Muhammad; Ismail, Nor Hadiani; Imran, Syahrul; Rahim, Fazal; Wadood, Abdul; Khan, Huma; Ullah, Hayat; Salar, Uzma; Khan, Khalid Mohammed

    2016-10-01

    Hybrid bisindole-thiosemicarbazides analogs (1-18) were synthesized and screened for β-glucuronidase activity. All compounds showed varied degree of β-glucuronidase inhibitory potential when compared with standard d-saccharic acid 1,4-lactone (IC50=48.4±1.25μM). Compounds 4, 7, 9, 6, 5, 12, 17 and 18 showed exceptional β-glucuronidase inhibition with IC50 values ranging from 0.1 to 5.7μM. Compounds 1, 3, 8, 16, 13, 2 and 14 also showed better activities than standard with IC50 values ranging from 7.12 to 15.0μM. The remaining compounds 10, 11, and 15 showed good inhibitory potential with IC50 values 33.2±0.75, 21.4±0.30 and 28.12±0.25μM respectively. Molecular docking studies were carried out to confirm the binding interaction of the compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Rock Abrasion and Ventifact Formation on Mars from Field Analog, Theoretical, and Experimental Studies

    Science.gov (United States)

    Bridges, N. T.; Laity, J. E.

    2001-01-01

    Rocks observed by the Viking Landers and Pathfinder Lander/Sojourner rover exhibit a suite of perplexing rock textures. Among these are pits, spongy textures, penetrative flutes, lineaments, crusts, and knobs Fluvial, impact, chemical alteration, and aeolian mechanisms have been proposed for many of these. In an effort to better understand the origin and characteristics of Martian rock textures, abraded rocks in the Mojave Desert and other regions have been studied. We find that most Martian rock textures, as opposed to just a few, bear close resemblance to terrestrial aeolian textures and can most easily be explained by wind, not other, processes. Flutes, grooves, and some pits on Mars are consistent with abrasion by saltating particles, as described previously. However, many other rock textures probably also have an aeolian origin. Sills at the base of rocks that generally lie at high elevations, such as Half Dome, are consistent with such features on Earth that are related to moats or soil ramps that shield the basal part of the rock from erosion. Crusts consisting of fluted fabrics, such as those on Stimpy and Chimp, are similar to fluted crusts on Earth that spall off over time. Knobby and lineated rocks are similar to terrestrial examples of heterogeneous rocks that differentially erode. The location of specific rock textures on Mars also gives insight into their origin. Many of the most diagnostic ventifacts found at the Pathfinder site are located on rocks that lie near the crests or the upper slopes of ridges. On Earth, the most active ventifact formation occurs on sloped or elevated topography, where windflow is accelerated and particle kinetic energy and flux are increased. Integrated 0 together, these observations point to significant aeolian 0 modification of rocks on Mars and cast doubt on whether many primary textures resulting from other processes are preserved. Experimental simulations of abrasion in the presence of abundant sand indicate that

  15. Development of an experimental approach to study coupled soil-plant-atmosphere processes using plant analogs

    Science.gov (United States)

    Trautz, Andrew C.; Illangasekare, Tissa H.; Rodriguez-Iturbe, Ignacio; Heck, Katharina; Helmig, Rainer

    2017-04-01

    The atmosphere, soils, and vegetation near the land-atmosphere interface are in a state of continuous dynamic interaction via a myriad of complex interrelated feedback processes which collectively, remain poorly understood. Studying the fundamental nature and dynamics of such processes in atmospheric, ecological, and/or hydrological contexts in the field setting presents many challenges; current experimental approaches are an important factor given a general lack of control and high measurement uncertainty. In an effort to address these issues and reduce overall complexity, new experimental design considerations (two-dimensional intermediate-scale coupled wind tunnel-synthetic aquifer testing using synthetic plants) for studying soil-plant-atmosphere continuum soil moisture dynamics are introduced and tested in this study. Validation of these experimental considerations, particularly the adoption of synthetic plants, is required prior to their application in future research. A comparison of three experiments with bare soil surfaces or transplanted with a Stargazer lily/limestone block was used to evaluate the feasibility of the proposed approaches. Results demonstrate that coupled wind tunnel-porous media experimentation, used to simulate field conditions, reduces complexity, and enhances control while allowing fine spatial-temporal resolution measurements to be made using state-of-the-art technologies. Synthetic plants further help reduce system complexity (e.g., airflow) while preserving the basic hydrodynamic functions of plants (e.g., water uptake and transpiration). The trends and distributions of key measured atmospheric and subsurface spatial and temporal variables (e.g., soil moisture, relative humidity, temperature, air velocity) were comparable, showing that synthetic plants can be used as simple, idealized, nonbiological analogs for living vegetation in fundamental hydrodynamic studies.

  16. Analogical Reasoning and Computer Programming.

    Science.gov (United States)

    Clement, Catherine A.; And Others

    1986-01-01

    A study of correlations between analogical reasoning and Logo programming mastery among female high school students related the results of pretests of analogical reasoning to posttests of programming mastery. A significant correlation was found between analogical reasoning and the ability to write subprocedures for use in several different…

  17. Isotopic studies of rare gases in terrestrial samples and natural nucleosynthesis

    International Nuclear Information System (INIS)

    1990-07-01

    This project is concerned with research in rare gas mass spectrometry. We read the natural record that isotopes of the rare gases provide. We study fluids using a system (RARGA) that is sometimes deployed in the field. In 1990 there was a strong effort to reduce the backlog of RARGA samples on hand, so that it was a year of intensive data gathering. Samples from five different areas in the western United States and samples from Guatemala and Australia were analyzed. In a collaborative study we also began analyzing noble gases from rocks associated with the fluids. An important objective, continuing in 1991, is to understand better the reasons for somewhat elevated 3 He/ 4 He ratios in regions where there is no contemporary volcanism which could produce the effect by addition of mantle helium. Our helium data have given us and our collaborators some insights, which are to be followed up, into gold mineralization in geothermal regions. Our DOE work in calibrating a sensitive laser microprobe mass spectrometer for noble gases in fluid inclusions continues. Having completed a series of papers on noble gases in diamonds, we next will attempt to make precise isotopic measurements on xenon from mantle sources, in search of evidence for terrestrially elusive 244 Pu decay

  18. Isotopic studies of rare gases in terrestrial samples and natural nucleosynthesis

    International Nuclear Information System (INIS)

    Reynolds, J.H.

    1991-01-01

    This project is concerned with research in rare gas mass spectrometry. We read the natural record that isotopes of the rate gases provide. We study fluids using a system (RARGA) that is sometimes deployed in the field. In 1990 there was a strong effort to reduce the backlog of RARGA samples on hand, so that it was a year of intensive data gathering. Samples from five different areas in the Western United States and samples from Guatemala and Australia were analyzed. In a collaborative study we also began analyzing noble gases from rocks associated with the fluids. An important objective, continuing in 1991, is to understand better the reasons for somewhat elevated 3 He/ 4 He ratios in regions where there is no contemporary volcanism which could produce the effect by addition of mantle helium. Our helium data have given us and our collaborators some insights, which are to be followed up, into gold mineralization in geothermal regions. Our DOE work in calibrating a sensitive laser microprobe mass spectrometer for noble gases in fluid inclusions continues. Having completed a series of papers on noble gases in diamonds, we next will attempt to make precise isotopic measurements on xenon from mantle sources in search of evidence for terrestrially elusive 244 Pu decay. 41 refs., 3 figs

  19. The analogy in the formation of hardness salts and gallstones according to the EPR study

    Science.gov (United States)

    Pichugina, Alina; Tsyro, Larisa; Unger, Felix

    2017-11-01

    The article shows that the hardness salts contain the same crystalline phases as the bile stone pigment. The identity of EPR spectra of hardness salts and pigment of gallstones containing calcium carbonate was established. An analogy between the processes of formation of hardness salts and gallstones is played, in which particles with open spin-orbitals (fermions) play a decisive role.

  20. Study of the interaction between bovine hemoglobin and analogs of biphenyldicarboxylate by spectrofluorimetry

    International Nuclear Information System (INIS)

    Wang, Ruiyong; Yin, Yujing; Wang, Ruiqiang; Xie, Yuanzhe; Ge, Baoyu; Li, Zhigang; Li, Zhen; Shi, Jie; Chang, Junbiao

    2013-01-01

    The interaction between bovine hemoglobin and analogs of Biphenyldicarboxylate was investigated by fluorescence, synchronous fluorescence, ultraviolet–vis absorbance, resonance light-scattering spectra and three-dimensional fluorescence spectra at pH 7.40. The quenching mechanism and binding constants were determined by the quenching of bovine hemoglobin fluorescence in presence of analogs. Results showed that the nature of the quenching was of static type. Both the van der Waals and hydrogen bonding played a major role in stabilizing the complex. The distance between donor and acceptors was obtained to be 2.11–2.25 nm according to Förster's theory. The influence of analogs on the conformation of bovine hemoglobin was investigated. -- Highlights: • The interactions between bovine hemoglobin and analogs of DDB have been investigated. • Results reveal that DDB has the strongest affinity for hemoglobin among four compounds. • The van der Waals and hydrogen bonding play major role in the binding process. • The influence of molecular structure on the binding aspects has been investigated

  1. Structural studies of nucleoside analog and feedback inhibitor binding to Drosophila melanogaster multisubstrate deoxyribonucleoside kinase

    DEFF Research Database (Denmark)

    Mikkelsen, Niels Egil; Munch-Petersen, Birgitte; Eklund, Hans

    2008-01-01

    -drug that eventually may kill the cell. To be able to optimize the function of dNK, it is vital to have structural information of dNK complexes. Here we present crystal structures of dNK complexed with four different nucleoside analogs floxuridine (5FdU), brivudine (BVDU), zidovudine (AZT) and zalcitabine (ddC...

  2. Cernavoda NPP impact study on terrestrial and aquatic biota. Preliminary results

    International Nuclear Information System (INIS)

    Bobric, Elena; Bucur, Cristina; Popescu, Ion; Simionov, Vasile; Titescu, Gheorghe; Varlam, Carmen

    2010-01-01

    Recently, the awareness of the vulnerability of the environment has increased and the need to protect it against industrial pollutants has been recognized. The concept of sustainable development, requires new and developing international policies for environmental protection. See 'Protection of the environment from the effects of ionizing radiation' IAEA-TECDOC-1091, International Atomic Energy Agency, Vienna. As it is recommended in 'Cernavoda Unit No. 2 NPP Environmental Impact Assessment CES-03702-IAD-006', it is Cernavoda NPP responsibility to conduct an Ecological Risk Assessment study, mainly to assess the impact of nuclear power plant operation on terrestrial and aquatic biota. Long records from normal operation of Cernavoda Unit 1, wind pattern, meteorological conditions, and source terms data were used to evaluate areas of interest for environmental impact, conducting to a circle of 20 km radius around mentioned nuclear objective. The screening campaign established tritium level (because Cernavoda NPP is a CANDU type reactor, and tritium is the most important radioisotope evacuated in the environment) in air, water, soil and vegetation, focusing the interest area on particular ecosystem. Using these primary data it was evaluated which are the monitored ecological receptors and which are the measurement endpoints.This paper presents the Ecological Risk Assessment at Cernavoda NPP technical requirements, and the preliminary results of evaluating criteria for representative ecosystem components at Cernavoda NPP. (authors)

  3. Study of high-spin analog resonances near the N=50 neutron shell

    International Nuclear Information System (INIS)

    Gales, S.; El Hage, Y.; Schapira, J.P.; Fortier, S.; Laurent, H.; Maison, J.M.

    1979-01-01

    The 96 Zr( 3 He,d) 97 Nb and the 92 Mo( 3 He,d) 93 Tc reactions, investigated at, respectively 39.0 and 28.5 MeV incident energies, were used to selectively populate high-spin analog resonances in the 97 Nb and 93 Tc nuclei. Angular distributions were measured for the dsub(3/2), gsub(7/2) and hsub(11/2) analog states of the low-lying levels in 97 Zr. A DWBA analysis of the data for these unbound levels (using Gamov functions as form factors) was carried out and spectroscopic strengths extracted. The 96 Zr( 3 He,dp) and 92 Mo( 3 He,dp) reactions were performed, respectively, at 37.5 and 30 MeV incident energies. The angular distributions of the emitted protons were measured in coincidence using method II of Litherland and Ferguson with 0 0 detection of deuteron groups. Spins, population parameters and proton branching ratios to the ground state and excited states of the targets were determined from the analysis of the angular correlation data. The position of the neutron threshold as compared with the excitation energies of the analog states in 97 Nb and 93 Tc is found to be an important parameter in the extraction of the structure informations on core-excited components in the parent levels wave functions. Neutron particle-hole multiplets are observed for the first time in 96 Zr through the decay of the gsub(7 /2) and hsub(11/2) analog resonances. The limitation of the present method due to the neutron threshold or to the energy resolution in the proton channel is discussed and compared with the results of inelastic resonant scattering through isobaric analog resonances

  4. How We Used NASA Lunar Set in Planetary Material Science Analog Studies on Lunar Basalts and Breccias with Industrial Materials of Steels and Ceramics

    Science.gov (United States)

    Berczi, S.; Cech, V.; Jozsa, S.; Szakmany, G.; Fabriczy, A.; Foldi, T.; Varga, T.

    2005-01-01

    Analog studies play important role in space materials education. Various aspects of analogies are used in our courses. In this year two main rock types of NASA Lunar Set were used in analog studies in respect of processes and textures with selected industrial material samples. For breccias and basalts on the lunar side, ceramics and steels were found as analogs on the industrial side. Their processing steps were identified on the basis of their textures both in lunar and in industrial groups of materials.

  5. Field studies on the terrestrial behavior of actinide elements in East Tennessee

    International Nuclear Information System (INIS)

    Garten, C.T. Jr.; Bondietti, E.A.; Trabalka, J.R.; Walker, R.L.; Scott, T.G.

    1984-01-01

    Field studies on the comparative uptake of various actinide elements ( 232 Th, 233 U, 238 U, 239 Pu, 241 Am, and 244 Cm) by plants and animals inhabiting historically contaminated environments on the Oak Ridge National Laboratory (ORNL) reservation in East Tennessee are summarized. The present-day pattern of actinide element bioaccumulation from a flood plain site contaminated with Pu in 1944 is U > Th approx. Pu. Thus the environmentally dispersed 239 Pu exhibits a transfer from floodplain soil to biota comparable to that of indigenous 232 Th and less than that of the indigenous 238 U. This ranking agrees with the chemical extractability of U, Th, and Pu from soil, using either weak acids or strongly basic reagents. The pattern of actinide element uptake from the shoreline of a historically contaminated pond is Pu 238 U = 233 U. This ranking also agrees with the chemical extractability of Pu, Am, Cm, and U from shoreline sediment, using weak acids. Results from field studies at ORNL agree with what has been generally inferred about the relative food chain transfer of the actinides, based on laboratory studies and field studies at other sites in the United States. Because they share the same valence state, there are apparent strong similarities in soil sorption, plant uptake, and animal uptake between trivalent Am and Cm and between tetravalent Pu and Th. Available evidence suggests that knowledge of the behavior of naturally occurring 232 Th in the terrestrial food chain can be useful for predicting the long-term fate of environmentally dispersed 239 Pu, while data on 238 U might be used to place an upper limit on the expected long-term food chain transfer of all transuranic elements except Np. 33 references, 5 figures, 1 table

  6. Evaluating the effects of herbicide drift on nontarget terrestrial plants: A case study with mesotrione.

    Science.gov (United States)

    Brain, Richard A; Perine, Jeff; Cooke, Catriona; Ellis, Clare Butler; Harrington, Paul; Lane, Andrew; O'Sullivan, Christine; Ledson, Mark

    2017-09-01

    Nature of exposure is a fundamental driver in nontarget terrestrial plant risk assessment for pesticides; consequently a novel study was designed to generate field-based drift exposure and evaluate corresponding biological effects of the herbicide mesotrione. The approach used a combination of US guideline drift reduction technology and vegetative vigor approaches. In each of 3 independent replicate spray application trials, 10 pots each of lettuce and tomato were placed at distances of 10, 20, 30, 40, and 50 ft (∼3, 6, 9, 12, and 15 m) from the downwind edge of the spray boom. Each application was conducted using a commercial 60-ft (18-m) boom sprayer fitted with TeeJet ® Technologies TTI110025 nozzles, with a nominal application rate of 0.2 lb a.i./A (224 g a.i./ha). The environmental conditions required by the protocol (air temperature 10-30 °C and wind perpendicular to the swath (±30°) blowing toward the plants at a mean wind speed of ≥10 mph [≥4.5 m/s] measured at 2.0 m above the ground) were met for each application. Following exposure, plants were transferred to a greenhouse for the 21-d vegetative vigor phase of the study. Symptoms of phytotoxicity and plant height were assessed at 7, 14, and 21 d after treatment. On completion of the 21-d after treatment assessment, all plants were harvested and dried in an oven to determine shoot dry weight. The biological data indicated that no statistically significant effects were observed at a distance of 30 ft (∼9 m) from mesotrione drift at wind speeds of ≥10 mph (10.9-12.4 mph); this endpoint (30 ft) is defined as the no observed effects distance (NOED). Environ Toxicol Chem 2017;36:2465-2475. © 2017 SETAC. © 2017 SETAC.

  7. A study of the terrestrial and cosmic gamma-rays in Jordan

    International Nuclear Information System (INIS)

    Mansi, M. A.

    1996-01-01

    Natural terrestrial gamma and cosmic radiations dose rates in Jordan were measured during a period of three years in thirty four stations distributed over all Jordanian territories using the thermoluminescence dosimeter(TLD) Coso 4 :Tm. The average absorbed dose rates in air from terrestrial gamma and cosmic radiations were found to vary from(57 ±3;9) n Gy/hr in Assafi to (350 ± 14; 42) n Gy/hr in Manjam Alhisa. The mean dose rate due to terrestrial gamma radiations was found to be equal to (55 ± 2; 13) nGy/hr, and that due to cosmic radiations was calculated to be(35 ± 1;4) n Gy/hr. The annual effective dose equivalent from terrestrial and cosmic gamma radiations was found to be equal to(0.65±0.02; 0.12)mSv/year. It was found that the absorbed dose rate due to cosmic radiations in Jordan can be fitted by the formula, D c osmic=27+5.2 h+1.86 h 2 where h is the altitude reference to the Dead Sea measured in km. 19 refs., 17 figs., 6 tabs.(Author)

  8. In Vivo Effects of Preservative-free and Preserved Prostaglandin Analogs: Mouse Ocular Surface Study.

    Science.gov (United States)

    Kim, Jee Hyun; Kim, Eun Joo; Kim, Yeoun-Hee; Kim, Yong Il; Lee, Se-Hyung; Jung, Jae-Chang; Lee, Kyoo Won; Park, Young Jeung

    2015-08-01

    Chronic use of topical hypotensive agents induces several side effects caused by preservatives. The purpose of this study was to evaluate the effects of prostaglandin analogs with varying concentrations of benzalkonium chloride (BAC), preservative-free (PF), and alternative preservatives on mouse corneal tissue. Thirty-five, 8- to 10-week-old female C57BL/6 mice (five mice for each group) were used for this study. To the control group, we applied normal saline, and to each drug-treated group we applied 0.02% BAC, bimatoprost 0.01% (with BAC 0.02%), latanoprost 0.005% (with BAC 0.02%), travoprost 0.004% (with 0.001% polyquad) or tafluprost 0.0015% with/without 0.001% BAC, once a day (9 p.m.) for 4 weeks. Corneal fluorescein staining was evaluated in all groups. After harvest, the corneal tissues were embedded in paraffin and then Hematoxylin-Eosin stain was performed for histopathological examination. Immunofluorescence staining was done against TNF-α, IL-6, HLA DR, pJNK, and pAkt. In corneal fluorescein staining, severe punctate epithelial keratitis was seen in the groups of 0.02% BAC, 0.02% BAC containing bimatoprost 0.01% and latanoprost 0.005%. The surface desquamation, irregular surface, loss of cell borders, anisocytosis and stromal shrinkage were observed in the groups of BAC-containing eye drops. Moreover, the groups treated with BAC-containing eye drops have high inflammatory markers, significantly decreased cell viability-related signal, pAkt, and higher apoptosis-inducing signal, pJNK, than the control group. On the other hand, travoprost 0.004% and PF tafluprost 0.0015% have less cellular morphologic changes, lower inflammation, and higher cellular viability than BAC-containing formulations. Corneal damage, increased inflammation and apoptosis and low cell viability were observed in BAC-containing groups. PF or alternatively preserved glaucoma medications seem to be a reasonable and viable alternative to those preserved with BAC.

  9. Hints of Habitable Environments on Mars Challenge Our Studies of Mars-Analog Sites on Earth

    Science.gov (United States)

    desMarais, David J

    2009-01-01

    environments persisted in the near-subsurface for hundreds of millions of years and might exist even today. Studies of Mars-analog environments must better understand subsurface nonphotosynthetic ecosystems and their biosignatures in mafic and ultramafic terranes. Studies must determine minimum needs for water activity and energy and also establish survival limits when conditions that support active metabolism and propagation become progressively less frequent over time.

  10. Analogical scaffolding: Making meaning in physics through representation and analogy

    Science.gov (United States)

    Podolefsky, Noah Solomon

    This work reviews the literature on analogy, introduces a new model of analogy, and presents a series of experiments that test and confirm the utility of this model to describe and predict student learning in physics with analogy. Pilot studies demonstrate that representations (e.g., diagrams) can play a key role in students' use of analogy. A new model of analogy, Analogical Scaffolding, is developed to explain these initial empirical results. This model will be described in detail, and then applied to describe and predict the outcomes of further experiments. Two large-scale (N>100) studies will demonstrate that: (1) students taught with analogies, according to the Analogical Scaffolding model, outperform students taught without analogies on pre-post assessments focused on electromagnetic waves; (2) the representational forms used to teach with analogy can play a significant role in student learning, with students in one treatment group outperforming students in other treatment groups by factors of two or three. It will be demonstrated that Analogical Scaffolding can be used to predict these results, as well as finer-grained results such as the types of distracters students choose in different treatment groups, and to describe and analyze student reasoning in interviews. Abstraction in physics is reconsidered using Analogical Scaffolding. An operational definition of abstraction is developed within the Analogical Scaffolding framework and employed to explain (a) why physicists consider some ideas more abstract than others in physics, and (b) how students conceptions of these ideas can be modeled. This new approach to abstraction suggests novel approaches to curriculum design in physics using Analogical Scaffolding.

  11. Terrestrial magnetosphere

    International Nuclear Information System (INIS)

    Pande, D.C.; Agarwal, D.C.

    1982-01-01

    This paper presents a review about terrestrial magnetosphere. During the last few years considerable investigation have been carried out about the properties of Solar Wind and its interaction with planetary magnetic fields. It is therefore of high importance to accumulate all the investigations in a comprehensive form. The paper reviews the property of earth's magnetosphere, magnetosheath, magneto pause, polar cusps, bow shook and plasma sheath. (author)

  12. Stress distribution patterns of implant supported overdentures-analog versus finite element analysis: A comparative in-vitro study

    Directory of Open Access Journals (Sweden)

    Soumyadev Satpathy

    2015-01-01

    Full Text Available Aims and Objectives: The aim of this study was to asses & compare the load transfer characteristics of Ball/O-ring and Bar/Clip attachment systems in implant supported overdentures using analog and finite element analysis models. Methodology: For the analog part of the study, castable bar was used for the bar and clip attachment and a metallic housing with a rubber O-ring component was used for the ball/O-ring attachment. The stress on the implant surface was measured using the strain-gauge technique. For the finite element analysis, the model were fabricated and load applications were done in a similar manner as in analog study. Results: The difference between both the attachment systems was found to be statistically significant (P<0.001. Conclusion: Ball/O-ring attachment system transmitted lesser amount of stresses to the implants on the non-loading side, as compared to the Bar-Clip attachment system. When overall stress distribution is compared, the Bar-Clip attachment seems to perform better than the Ball/O-ring attachment, because the force was distributed better.

  13. Investigations in space-related molecular biology. [cryo-electron microscopic and diffraction studies on terrestrial and extraterrestrial specimens

    Science.gov (United States)

    Fernandez-Moran, H.; Pritzker, A. N.

    1974-01-01

    Improved instrumentation and preparation techniques for high resolution, high voltage cryo-electron microscopic and diffraction studies on terrestrial and extraterrestrial specimens are reported. Computer correlated ultrastructural and biochemical work on hydrated and dried cell membranes and related biological systems provided information on membrane organization, ice crystal formation and ordered water, RNA virus linked to cancer, lunar rock samples, and organometallic superconducting compounds. Apollo 11, 12, 14, and 15 specimens were analyzed

  14. The neural basis of analogical reasoning: an event-related potential study.

    Science.gov (United States)

    Qiu, Jiang; Li, Hong; Chen, Antao; Zhang, Qinglin

    2008-10-01

    The spatiotemporal analysis of brain activation during the execution of easy analogy (EA) and difficult analogy (DA) tasks was investigated using high-density event-related brain potentials (ERPs). Results showed that reasoning tasks (schema induction) elicited a more negative ERP deflection (N500-1000) than did the baseline task (BS) between 500 and 1000 ms. Dipole source analysis of difference waves (EA-BS and DA-BS) indicated that the negative components were both localized near the left thalamus, possibly associated with the retrieval of alphabetical information. Furthermore, DA elicited a more positive ERP component (P600-1000) than did EA in the same time window. Two generators of P600-1000 were located in the medial prefrontal cortex (BA10) and the left frontal cortex (BA6) which was possibly involved in integrating information in schema abstraction. In the stage of analogy mapping, a greater negativity (N400-600) in the reasoning tasks as compared to BS was found over fronto-central scalp regions. A generator of this effect was located in the left fusiform gyrus and was possibly related to associative memory and activation of schema. Then, a greater negativity in the reasoning tasks, in comparison to BS task, developed between 900-1200 ms (LNC1) and 2000-2500 ms (LNC2). Dipole source analysis (EA-BS) localized the generator of LNC1 in the left prefrontal cortex (BA 10) which was possibly related to mapping the schema to the target problem, and the generator of LNC2 in the left prefrontal cortex (BA 9) which was possibly related to deciding whether a conclusion correctly follows from the schema.

  15. Study on transfer coefficients of 90Sr, 137Cs, natural U, 226Ra and 239Pu in terrestrial food chains

    International Nuclear Information System (INIS)

    Qin Suyun; Qi Yong; Li Shuqin; Zhou Caiyun; Zhang Jingjuan; Li Jikai; Li Xuequn

    1995-01-01

    The aim of study was to provide values of transfer parameter of 90 Sr, 137 Cs, Natural U, 226 Ra and 239 Pu in terrestrial food chains, more applicable for Chinese socio-natural conditions. Data of radionuclides contents in agricultural crops and in associated soils, in sheep tissues and in associated grasses were collected in couples. The transfer coefficients in terrestrial food chains (soil-crops, grasses-sheep tissues) were calculated. On basis of statistical analysis, the representative values and 95% ranges of transfer coefficient for 5 radionuclides in 7 kind of agricultural products for southern moist areas and north dry areas were given. Regression analysis showed that relation between the transfer coefficients and the radionuclide contents in their associated soils present a negative correlation, it could be described with a equation: Y = aX -b

  16. Equatorial secondary cosmic ray observatory to study space weather and terrestrial events

    Science.gov (United States)

    Vichare, Geeta; Bhaskar, Ankush; Datar, Gauri; Raghav, Anil; Nair, K. U.; Selvaraj, C.; Ananthi, M.; Sinha, A. K.; Paranjape, M.; Gawade, T.; Anil Kumar, C. P.; Panneerselvam, C.; Sathishkumar, S.; Gurubaran, S.

    2018-05-01

    Recently, equatorial secondary cosmic ray observatory has been established at Equatorial Geophysical Research Laboratory (EGRL), Tirunelveli, (Geographic Coordinates: 8.71°N, 77.76°E), to study secondary cosmic rays (SCR) produced due to the interaction of primary cosmic rays with the Earth's atmosphere. EGRL is a regional center of Indian Institute of Geomagnetism (IIG), located near the equator in the Southern part of India. Two NaI(Tl) scintillation detectors are installed inside the temperature controlled environment. One detector is cylindrical in shape of size 7.62 cm × 7.62 cm and another one is rectangular cuboid of 10.16 cm × 10.16 cm × 40.64 cm size. Besides NaI(Tl) detectors, various other research facilities such as the Geomagnetic observatory, Medium Frequency Radar System, Digital Ionosonde, All-sky airglow imager, Atmospheric electricity laboratory to measure the near-Earth atmospheric electric fields are also available at EGRL. With the accessibility of multi- instrument facilities, the objective is set to understand the relationship between SCR and various atmospheric and ionospheric processes, during space weather and terrestrial events. For gamma-ray spectroscopy, it is important to test the performance of the NaI(Tl) scintillation detectors and to calibrate the gamma-ray spectrum in terms of energy. The present article describes the details of the experimental setup installed near the equator to study cosmic rays, along with the performance testing and calibration of the detectors under various conditions. A systematic shift in the gain is observed with varying temperature of the detector system. It is found that the detector's response to the variations in the temperature is not just linear or non-linear type, but it depends on the history of the variation, indicating temperature hysteresis effects on NaI detector and PMT system. This signifies the importance of isothermal environment while studying SCR flux using NaI(Tl) detectors

  17. Detecting analogical resemblance without retrieving the source analogy.

    Science.gov (United States)

    Kostic, Bogdan; Cleary, Anne M; Severin, Kaye; Miller, Samuel W

    2010-06-01

    We examined whether people can detect analogical resemblance to an earlier experimental episode without being able to recall the experimental source of the analogical resemblance. We used four-word analogies (e.g., robin-nest/beaver-dam), in a variation of the recognition-without-cued-recall method (Cleary, 2004). Participants studied word pairs (e.g., robin-nest) and were shown new word pairs at test, half of which analogically related to studied word pairs (e.g., beaver-dam) and half of which did not. For each test pair, participants first attempted to recall an analogically similar pair from the study list. Then, regardless of whether successful recall occurred, participants were prompted to rate the familiarity of the test pair, which was said to indicate the likelihood that a pair that was analogically similar to the test pair had been studied. Across three experiments, participants demonstrated an ability to detect analogical resemblance without recalling the source analogy. Findings are discussed in terms of their potential relevance to the study of analogical reasoning and insight, as well as to the study of familiarity and recognition memory.

  18. A diagnostic study of temperature controls on global terrestrial carbon exchange

    International Nuclear Information System (INIS)

    Vukicevic, Tomislava; Schimel, David

    2001-01-01

    The observed interannual variability of atmospheric CO 2 reflects short-term variability in sources and sinks of CO 2 . Analyses using 13 C and O 2 suggest that much of the observed interannual variability is due to changes in terrestrial CO 2 exchange. First principles, empirical correlations and process models suggest a link between climate variation and net ecosystem exchange, but the scaling of ecological process studies to the globe is notoriously difficult. We sought to identify a component of global CO 2 exchange that varied coherently with land temperature anomalies using an inverse modeling approach. We developed a family of simplified spatially aggregated ecosystem models (designated K-model versions) consisting of five compartments: atmospheric CO 2 , live vegetation, litter, and two soil pools that differ in turnover times. The pools represent cumulative differences from mean storage due to temperature variability and can thus have positive or negative values. Uptake and respiration of CO 2 are assumed to be linearly dependent on temperature. One model version includes a simple representation of the nitrogen cycle in which changes in the litter and soil carbon pools result in stoichiometric release of plant-available nitrogen, the other omits the nitrogen feedback. The model parameters were estimated by inversion of the model against global temperature and CO 2 anomaly data using the variational method. We found that the temperature sensitivity of carbon uptake (NPP) was less than that of respiration in all model versions. Analyses of model and data also showed that temperature anomalies trigger ecosystem changes on multiple, lagged time-scales. Other recent studies have suggested a more active land biosphere at Northern latitudes in response to warming and longer growing seasons. Our results indicate that warming should increase NPP, consistent with this theory, but that respiration should increase more than NPP, leading to decreased or negative NEP. A

  19. Study of archaeological analogs for the validation of nuclear glass long-term behavior models

    International Nuclear Information System (INIS)

    Verney-Carron, A.

    2008-10-01

    Fractured archaeological glass blocks collected from a shipwreck discovered in the Mediterranean Sea near Embiez Island (Var) were investigated because of their morphological analogy with vitrified nuclear waste and of a known and stable environment. These glasses are fractured due to a fast cooling after they were melted (like nuclear glass) and have been altered for 1800 years in seawater. This work results in the development and the validation of a geochemical model able to simulate the alteration of a fractured archaeological glass block over 1800 years. The kinetics associated with the different mechanisms (interdiffusion and dissolution) and the thermodynamic parameters of the model were determined by leaching experiments. The model implemented in HYTEC software was used to simulate crack alteration over 1800 years. The consistency between simulated alteration thicknesses and measured data on glass blocks validate the capacity of the model to predict long-term alteration. This model is able to account for the results from the characterization of crack network and its state of alteration. The cracks in the border zone are the most altered due to a fast renewal of the leaching solution, whereas internal cracks are thin because of complex interactions between glass alteration and transport of elements in solution (influence of initial crack aperture and of the crack sealing). The lowest alteration thicknesses, as well as their variability, can be explained. The analog behavior of archaeological and nuclear glasses from leaching experiments makes possible the transposition of the model to nuclear glass in geological repository. (author)

  20. Feasibility study of a small, thorium-based fission power system for space and terrestrial applications

    Science.gov (United States)

    Worrall, Michael Jason

    One of the current challenges facing space exploration is the creation of a power source capable of providing useful energy for the entire duration of a mission. Historically, radioisotope batteries have been used to provide load power, but this conventional system may not be capable of sustaining continuous power for longer duration missions. To remedy this, many forays into nuclear powered spacecraft have been investigated, but no robust system for long-term power generation has been found. In this study, a novel spin on the traditional fission power system that represents a potential optimum solution is presented. By utilizing mature High Temperature Gas Reactor (HTGR) technology in conjunction with the capabilities of the thorium fuel cycle, we have created a light-weight, long-term power source capable of a continuous electric power output of up to 70kW for over 15 years. This system relies upon a combination of fissile, highly-enriched uranium dioxide and fertile thorium carbide Tri-Structural Isotropic (TRISO) fuel particles embedded in a hexagonal beryllium oxide matrix. As the primary fissile material is consumed, the fertile material breeds new fissile material leading to more steady fuel loading over the lifetime of the core. Reactor control is achieved through an innovative approach to the conventional boron carbide neutron absorber by utilizing sections of borated aluminum placed in rotating control drums within the reflector. Borated aluminum allows for much smaller boron concentrations, thus eliminating the potential for 10B(n,alpha)6Li heating issues that are common in boron carbide systems. A wide range of other reactivity control systems are also investigated, such as a radially-split rotating reflector. Lastly, an extension of the design to a terrestrial based system is investigated. In this system, uranium enrichment is dropped to 20 percent in order to meet current regulations, a solid uranium-zirconium hydride fissile driver replaces the

  1. Changes of radio-technological studies in the field of medical imaging. From analogous studies to digital ones

    International Nuclear Information System (INIS)

    Shiraishi, Junji; Uchiyama, Yoshikazu; Honda, Michitaka; Ogura, Toshihiro; Kunitomo, Hiroshi; Kishimoto, Kenji; Ishii, Rie; Hara, Takeshi; Tanaka, Rie

    2014-01-01

    Eight authors briefly describe practical reviews of domestic changes in the title of their expertized field for the purpose of enlightenment. Reviews concern following studies: on the construction of medical images, on characteristics of input/output, of resolution, of noise, on whole assessment of images with noise-equivalent number of quanta/detective quantum efficiency (NEQ/DQE), with subjectivity, on computer-aided diagnosis (CAD), and on image displaying system assessment. X-ray image subtraction along with the development of CT is the origin of real-time digitalized image construction. Studies on the input/output affects the quality of images and exposure dose to patients, which have contributed to works of investigators at manufacturing and technologists on site. Then described are changes in the assessment of image by digital radiography (DR), of which basis was originally established at analogous sensitizer/film (S/F) era, of image resolution and of noise characteristic assessment, during the period from S/F to DR systems. Assessment of images with NEQ/DQE has been essentially based on the description in the 'Image Science' published in 1974 and its derived domestic educational researches; and the assessment with subjectivity involves the receiver operating characteristic (ROC), which leads to computer-aided diagnosis (CAD). Studies on image display are now changing responding to clinical and social needs. (T.T.)

  2. The impact of analogies on creative concept generation: lessons from an in vivo study in engineering design.

    Science.gov (United States)

    Chan, Joel; Schunn, Christian

    2015-01-01

    Research on innovation often highlights analogies from sources outside the current problem domain as a major source of novel concepts; however, the mechanisms underlying this relationship are not well understood. We analyzed the temporal interplay between far analogy use and creative concept generation in a professional design team's brainstorming conversations, investigating the hypothesis that far analogies lead directly to very novel concepts via large steps in conceptual spaces (jumps). Surprisingly, we found that concepts were more similar to their preceding concepts after far analogy use compared to baseline situations (i.e., without far analogy use). Yet far analogies increased the team's concept generation rate compared to baseline conditions. Overall, these results challenge the view that far analogies primarily lead to novel concepts via jumps in conceptual spaces and suggest alternative pathways from far analogies to novel concepts (e.g., iterative, deep exploration within a functional space). Copyright © 2014 Cognitive Science Society, Inc.

  3. Does fear extinction in the laboratory predict outcomes of exposure therapy? A treatment analog study.

    Science.gov (United States)

    Forcadell, Eduard; Torrents-Rodas, David; Vervliet, Bram; Leiva, David; Tortella-Feliu, Miquel; Fullana, Miquel A

    2017-11-01

    Fear extinction models have a key role in our understanding of anxiety disorders and their treatment with exposure therapy. Here, we tested whether individual differences in fear extinction learning and fear extinction recall in the laboratory were associated with the outcomes of an exposure therapy analog (ETA). Fifty adults with fear of spiders participated in a two-day fear-learning paradigm assessing fear extinction learning and fear extinction recall, and then underwent a brief ETA. Correlational analyses indicated that enhanced extinction learning was associated with better ETA outcome. Our results partially support the idea that individual differences in fear extinction learning may be associated with exposure therapy outcome, but suggest that further research in this area is needed. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Subject-3: Study on migration of radionuclides released into terrestrial and aquatic environment after nuclear accident

    International Nuclear Information System (INIS)

    Amano, H.; Matsunaga, T.; Ueno, T.; Nagao, S.; Yanase, N.; Tkachenko, Yu.

    2001-01-01

    Subject-3 has been focused on the migration behavior of long-lived radionuclides in the terrestrial surface environment, especially in connection with their chemical and physical forms. Migration behavior of radionuclides is strongly affected with their chemical and physical forms (for example; Gunten and Benes 1995). One of the two categories in Subject-3 consists of migration from surface soils including aging effects of hot particles, plant uptake from contaminated soils, and resuspension of radionuclides. The other is run off by river system, considering the role of organic materials. (author)

  5. Water, soil, crops and radionuclides. Studies on the behavior of radionuclides in the terrestrial environments

    International Nuclear Information System (INIS)

    Uchida, Shigeo

    2008-01-01

    In order to predict the migration of artificially-produced radionuclides into a human body and its radiation dose rates of human body and to decrease the exposed radiation doses of human body, the behavior of radionuclides in the environment must be elucidated. In National Institute of Radiological Sciences (NIRS), the environmental radioecological research group of Nakaminato Laboratory for Marine Radioecology has progressed the survey and research on the behavior of artificially-produced radionuclides in the terrestrial environment. This article describes the research results (the radioactivity of water, soil, and crops) made so far at Nakaminato Laboratory for Marine Radioecology. (M.H.)

  6. Subject-3: Study on migration of radionuclides released into terrestrial and aquatic environment after nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Amano, H.; Matsunaga, T.; Ueno, T.; Nagao, S.; Yanase, N. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Arkhipov, A.N. [Chernobyl Scientific and Technical Center for International Research (Ukraine); Tkachenko, Yu. [The State Enterprise Regional Monitoring and Domestic Control (RADEC) (Unknown)

    2001-03-01

    Subject-3 has been focused on the migration behavior of long-lived radionuclides in the terrestrial surface environment, especially in connection with their chemical and physical forms. Migration behavior of radionuclides is strongly affected with their chemical and physical forms (for example; Gunten and Benes 1995). One of the two categories in Subject-3 consists of migration from surface soils including aging effects of hot particles, plant uptake from contaminated soils, and resuspension of radionuclides. The other is run off by river system, considering the role of organic materials. (author)

  7. A floodplain mesocosm study: Distribution, mobility, aging, and functioning of engineered silver nanoparticles at the aquatic-terrestrial interface

    Science.gov (United States)

    Metreveli, George; Kurtz, Sandra; Philippe, Allan; Tayyebi, Narjes; Seitz, Frank; Rosenfeldt, Ricki R.; Grün, Alexandra; Kumahor, Samuel K.; Baumann, Thomas; Bundschuh, Mirco; Lang, Friederike; Klitzke, Sondra; Manz, Werner; Schulz, Ralf; Vogel, Hans-Jörg; Schaumann, Gabriele E.

    2017-04-01

    With increasing use of engineered nanoparticles (ENPs) in different commercial products the risk for their release into the environment is continuously increased. The aging, distribution, mobility, biological availability, and ecotoxicological impact of ENPs in aquatic and terrestrial compartments will be influenced especially by the natural dynamics of meadow areas, which represent a sensible zone between these two compartments. In this study we present a newly developed floodplain stream mesocosm system linking aquatic and terrestrial aging of ENPs in one system. Using this system we investigated the distribution, mobility, and biological effects of silver nanoparticles (Ag NPs) at the aquatic-terrestrial interface. The mesocosm consists of a main channel, floodplain area, and transport columns simulating an aquatic compartment with river bed, aquatic-terrestrial transition zone, and terrestrial area, respectively. The system contained water sampled from the River Rhine, quartz sand as sediment phase and natural repacked soil from a Rhine floodplain. Every 3 weeks floodplain area was flooded for four days by increasing the water level in the main channel. The dispersions of Ag NPs were injected into the main channel as a pulse function with the pulse duration of 3 weeks and interval of 3 weeks between pulses. The biological effects of Ag NPs on the benthic organism Gammarus fossarum were evaluated in the bioassays during and between the Ag NP pulses. The total duration of the experiment was 33 weeks. The results of mesocosm experiments showed a fluctuating but successively increasing concentrations of total silver in the aqueous phase. At the end of the experiment 0.5% of the silver was still available in the aqueous phase mostly as nanoparticles. Although the major part of silver was immobilized in sediment and soil especially in their top layer, the feeding activity of Gammarus fossarum was not consistently affected. It is most likely due to the low

  8. Terrestrial gamma radiation dose study to determine the baseline for environmental radiological health practices in Melaka state, Malaysia

    International Nuclear Information System (INIS)

    Ramli, Ahmad Termizi; Sahrone, Sallehudin; Wagiran, Husin

    2005-01-01

    Environmental terrestrial gamma radiation dose rates were measured throughout Melaka, Malaysia, over a period of two years, with the objective of establishing baseline data on the background radiation level. Results obtained are shown in tabular, graphic and cartographic form. The values of terrestrial gamma radiation dose rate vary significantly over different soil types and for different underlying geological characteristics present in the study area. The values ranged from 54 ± 5 to 378 ± 38 nGy h -1 . The highest terrestrial gamma dose rates were measured over soil types of granitic origin and in areas with underlying geological characteristics of an acid intrusive (undifferentiated) type. An isodose map of terrestrial gamma dose rate in Melaka was drawn by using the GIS application 'Arc View'. This was based on data collected using a NaI(Tl) scintillation detector survey meter. The measurements were taken at 542 locations. Three small 'hot spots' were found where the dose rates were more than 350 nGy h -1 . The mean dose rates in the main population areas in the mukims (parishes) of Bukit Katil, Sungai Udang, Batu Berendam, Bukit Baru and Bandar Melaka were 154 ± 15, 161 ± 16, 160 ± 16, 175 ± 18 and 176 ± 18 nGy h -1 , respectively. The population-weighted mean dose rate throughout Melaka state is 172 ± 17 nGy h -1 . This is lower than the geographical mean dose rate of 183 ± 54 nGy h -1 . The lower value arises from the fact that most of the population lives in the central area of the state where the lithology is dominated by sedimentary rocks consisting of shale, mudstone, phyllite, slate, hornfels, sandstone and schist of Devonian origin which have lower associated dose rates. The mean annual effective dose to the population from outdoor terrestrial gamma radiation was estimated to be 0.21 mSv. This value is higher than the world average of 0.07 mSv

  9. An assessment of non-volant terrestrial vertebrates response to wind farms--a study of small mammals.

    Science.gov (United States)

    Łopucki, Rafał; Mróz, Iwona

    2016-02-01

    The majority of studies on the effects of wind energy development on wildlife have been focused on birds and bats, whereas knowledge of the response of terrestrial, non-flying vertebrates is very scarce. In this paper, the impact of three functioning wind farms on terrestrial small mammal communities (rodents and shrews) and the population parameters of the most abundant species were studied. The study was carried out in southeastern Poland within the foothills of the Outer Western Carpathians. Small mammals were captured at 12 sites around wind turbines and at 12 control sites. In total, from 1200 trap-days, 885 individuals of 14 studied mammal species were captured. There was no difference in the characteristics of communities of small mammals near wind turbines and within control sites; i.e. these types of sites were inhabited by a similar number of species of similar abundance, similar species composition, species diversity (H' index) and species evenness (J') (Pielou's index). For the two species with the highest proportion in the communities (Apodemus agrarius and Microtus arvalis), the parameters of their populations (mean body mass, sex ratio, the proportion of adult individuals and the proportion of reproductive female) were analysed. In both species, none of the analysed parameters differed significantly between sites in the vicinity of turbines and control sites. For future studies on the impact of wind turbines on small terrestrial mammals in different geographical areas and different species communities, we recommend the method of paired 'turbine-control sites' as appropriate for animal species with pronounced fluctuations in population numbers.

  10. Terrestrial scanning or digital images in inventory of monumental objects? - case study

    Science.gov (United States)

    Markiewicz, J. S.; Zawieska, D.

    2014-06-01

    Cultural heritage is the evidence of the past; monumental objects create the important part of the cultural heritage. Selection of a method to be applied depends on many factors, which include: the objectives of inventory, the object's volume, sumptuousness of architectural design, accessibility to the object, required terms and accuracy of works. The paper presents research and experimental works, which have been performed in the course of development of architectural documentation of elements of the external facades and interiors of the Wilanów Palace Museum in Warszawa. Point clouds, acquired from terrestrial laser scanning (Z+F 5003h) and digital images taken with Nikon D3X and Hasselblad H4D cameras were used. Advantages and disadvantages of utilisation of these technologies of measurements have been analysed with consideration of the influence of the structure and reflectance of investigated monumental surfaces on the quality of generation of photogrammetric products. The geometric quality of surfaces obtained from terrestrial laser scanning data and from point clouds resulting from digital images, have been compared.

  11. Bayesian calibration of terrestrial ecosystem models: a study of advanced Markov chain Monte Carlo methods

    Science.gov (United States)

    Lu, Dan; Ricciuto, Daniel; Walker, Anthony; Safta, Cosmin; Munger, William

    2017-09-01

    Calibration of terrestrial ecosystem models is important but challenging. Bayesian inference implemented by Markov chain Monte Carlo (MCMC) sampling provides a comprehensive framework to estimate model parameters and associated uncertainties using their posterior distributions. The effectiveness and efficiency of the method strongly depend on the MCMC algorithm used. In this work, a differential evolution adaptive Metropolis (DREAM) algorithm is used to estimate posterior distributions of 21 parameters for the data assimilation linked ecosystem carbon (DALEC) model using 14 years of daily net ecosystem exchange data collected at the Harvard Forest Environmental Measurement Site eddy-flux tower. The calibration of DREAM results in a better model fit and predictive performance compared to the popular adaptive Metropolis (AM) scheme. Moreover, DREAM indicates that two parameters controlling autumn phenology have multiple modes in their posterior distributions while AM only identifies one mode. The application suggests that DREAM is very suitable to calibrate complex terrestrial ecosystem models, where the uncertain parameter size is usually large and existence of local optima is always a concern. In addition, this effort justifies the assumptions of the error model used in Bayesian calibration according to the residual analysis. The result indicates that a heteroscedastic, correlated, Gaussian error model is appropriate for the problem, and the consequent constructed likelihood function can alleviate the underestimation of parameter uncertainty that is usually caused by using uncorrelated error models.

  12. Study of Subtropical Forestry Index Retrieval Using Terrestrial Laser Scanning and Hemispherical Photography

    Directory of Open Access Journals (Sweden)

    Ting Yun

    2015-01-01

    Full Text Available In order to retrieve gap fraction, leaf inclination angle, and leaf area index (LAI of subtropical forestry canopy, here we acquired forestry detailed information by means of hemispherical photography, terrestrial laser scanning, and LAI-2200 plant canopy analyzer. Meanwhile, we presented a series of image processing and computer graphics algorithms that include image and point cloud data (PCD segmentation methods for branch and leaf classification and PCD features, such as normal vector, tangent plane extraction, and hemispherical projection method for PCD coordinate transformation. In addition, various forestry mathematical models were proposed to deduce forestry canopy indexes based on the radiation transfer model of Beer-Lambert law. Through the comparison of the experimental results on many plot samples, the terrestrial laser scanner- (TLS- based index estimation method obtains results similar to digital hemispherical photograph (HP and LAI-2200 plant canopy analyzer taken of the same stands and used for validation. It indicates that the TLS-based algorithm is able to capture the variability in LAI of forest stands with a range of densities, and there is a high chance to enhance TLS as a calibration tool for other devices.

  13. A Study of an Architecture Design Learning Process Based on Social Learning, Course Teaching, Interaction, and Analogical Thinking

    Directory of Open Access Journals (Sweden)

    Yun-Wu Wu

    2014-01-01

    Full Text Available The students in the vocational education of architecture design in Taiwan often face many learning obstacles, such as no problem solving ability and lack of creativity. Therefore, this study used a social learning model as a learning strategy in the architecture design learning process to solve related learning difficulties. Firstly, this study used cognitive development teaching activities and a learning process based on analogical thinking and analogical reasoning to build the social learning model. Secondly, the social learning model of this study was implemented in the teaching of a required course of architecture design for 120 freshmen in China University of Technology. The questionnaire survey results were then statically analyzed and compared to measure the differences in the students’ knowledge about architecture designs before and after the teaching in this study. In this study, the social learning model is proven helpful in inspiring the students’ creativity by converting new knowledge of architecture design into schemas and hence retaining the new knowledge for future application. The social learning model can be applied in the teaching of architecture design in other schools, while more research can be conducted in the future to further confirm its feasibility to promote effective learning.

  14. The Influence of the Terrestrial Reference Frame on Studies of Sea Level Change

    Science.gov (United States)

    Nerem, R. S.; Bar-Sever, Y. E.; Haines, B. J.; Desai, S.; Heflin, M. B.

    2015-12-01

    The terrestrial reference frame (TRF) provides the foundation for the accurate monitoring of sea level using both ground-based (tide gauges) and space-based (satellite altimetry) techniques. For the latter, tide gauges are also used to monitor drifts in the satellite instruments over time. The accuracy of the terrestrial reference frame (TRF) is thus a critical component for both types of sea level measurements. The TRF is central to the formation of geocentric sea-surface height (SSH) measurements from satellite altimeter data. The computed satellite orbits are linked to a particular TRF via the assumed locations of the ground-based tracking systems. The manner in which TRF errors are expressed in the orbit solution (and thus SSH) is not straightforward, and depends on the models of the forces underlying the satellite's motion. We discuss this relationship, and provide examples of the systematic TRF-induced errors in the altimeter derived sea-level record. The TRF is also crucial to the interpretation of tide-gauge measurements, as it enables the separation of vertical land motion from volumetric changes in the water level. TRF errors affect tide gauge measurements through GNSS estimates of the vertical land motion at each tide gauge. This talk will discuss the current accuracy of the TRF and how errors in the TRF impact both satellite altimeter and tide gauge sea level measurements. We will also discuss simulations of how the proposed Geodetic Reference Antenna in SPace (GRASP) satellite mission could reduce these errors and revolutionize how reference frames are computed in general.

  15. Terrestrial planet formation.

    Science.gov (United States)

    Righter, K; O'Brien, D P

    2011-11-29

    Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (~10(6) y), followed by planetesimals to embryos (lunar to Mars-sized objects; few 10(6) y), and finally embryos to planets (10(7)-10(8) y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids.

  16. Conjecturing via Reconceived Classical Analogy

    Science.gov (United States)

    Lee, Kyeong-Hwa; Sriraman, Bharath

    2011-01-01

    Analogical reasoning is believed to be an efficient means of problem solving and construction of knowledge during the search for and the analysis of new mathematical objects. However, there is growing concern that despite everyday usage, learners are unable to transfer analogical reasoning to learning situations. This study aims at facilitating…

  17. Are ship tracks useful analogs for studying the aerosol indirect effect?

    Science.gov (United States)

    Christensen, M.; Toll, V.; Stephens, G. L.

    2017-12-01

    Vessels transiting the ocean sometimes leave their mark on the clouds - leaving behind reflective cloud lines, known as ship tracks. Ship tracks have been looked upon by some as a possible Rosetta Stone connecting the effects of changing aerosol over the ocean and cloud albedo effects on climate (Porch et al. 1990, Atmos. Enviorn., 1051-1059). In this research, we establish whether ship tracks, and volcano tracks - a natural analog, can be used to relate these cloud-scale perturbations to the aerosol effects occurring at larger regional-scales. Two databases containing over 1,500 ship and 900 volcano tracks, all carefully hand-selected from satellite imagery, are utilized; showing that ship tracks exhibit very similar cloud albedo effect responses to that of volcano tracks. For comparison, our global dataset utilises over 7 million CloudSat profiles consisting of single-layer marine warm cloud in which the retrievals are co-located with the MODerate Imaging Spectroradiometer (MODIS) product so that statistical relationships between aerosol and cloud can be computed over 4x4 degree regions. All datasets show the same key physical processes that govern the cloud-aerosol indirect effect, namely, the strong negative responses in cloud droplet size and the bidirectional responses in liquid water path and cloud albedo depending on the meteorological conditions. Finally, this analysis is extended to a comparison against several general circulation models where it is suggested that key processes such as cloud-top entrainment and evaporation that regulates against strong liquid water path responses are likely underrepresented in most models.

  18. Biopharmaceutical Characterization and Bioavailability Study of a Tetrazole Analog of Clofibric Acid in Rat.

    Science.gov (United States)

    Vara-Gama, Nancy; Valladares-Méndez, Adriana; Navarrete-Vazquez, Gabriel; Estrada-Soto, Samuel; Orozco-Castellanos, Luis Manuel; Rivera-Leyva, Julio César

    2017-02-14

    In the current investigation, the physicochemical, biopharmaceutical and pharmacokinetic characterization of a new clofibric acid analog (Compound 1 ) was evaluated. Compound 1 showed affinity by lipophilic phase in 1 to 5 pH interval, indicating that this compound would be absorbed favorably in duodenum or jejunum. Also, Compound 1 possess two ionic species, first above of pH 4.43 and, the second one is present over pH 6.08. The apparent permeability in everted sac rat intestine model was 8.73 × 10 -6 cm/s in duodenum and 1.62 × 10 -5 cm/s in jejunum, suggesting that Compound 1 has low permeability. Elimination constant after an oral administration of 50 μg/kg in Wistar rat was 1.81 h -1 , absorption constant was 3.05 h -1 , C max was 3.57 μg/mL at 0.33 h, AUC 0-α was 956.54 μ/mL·h and distribution volume was 419.4 mL. To IV administration at the same dose, ke was 1.21 h -1 , Vd was 399.6 mL and AUC 0-α was 747.81 μ/mL·h. No significant differences were observed between pharmacokinetic parameters at every administration route. Bioavailability evaluated was 10.4%. Compound 1 is metabolized to Compound 2 probably by enzymatic hydrolysis, and it showed a half-life of 9.24 h. With these properties, Compound 1 would be considered as a prodrug of Compound 2 with potential as an antidiabetic and anti dyslipidemic agent.

  19. Biopharmaceutical Characterization and Bioavailability Study of a Tetrazole Analog of Clofibric Acid in Rat

    Directory of Open Access Journals (Sweden)

    Nancy Vara-Gama

    2017-02-01

    Full Text Available In the current investigation, the physicochemical, biopharmaceutical and pharmacokinetic characterization of a new clofibric acid analog (Compound 1 was evaluated. Compound 1 showed affinity by lipophilic phase in 1 to 5 pH interval, indicating that this compound would be absorbed favorably in duodenum or jejunum. Also, Compound 1 possess two ionic species, first above of pH 4.43 and, the second one is present over pH 6.08. The apparent permeability in everted sac rat intestine model was 8.73 × 10−6 cm/s in duodenum and 1.62 × 10−5 cm/s in jejunum, suggesting that Compound 1 has low permeability. Elimination constant after an oral administration of 50 μg/kg in Wistar rat was 1.81 h−1, absorption constant was 3.05 h−1, Cmax was 3.57 μg/mL at 0.33 h, AUC0–α was 956.54 μ/mL·h and distribution volume was 419.4 mL. To IV administration at the same dose, ke was 1.21 h−1, Vd was 399.6 mL and AUC0–α was 747.81 μ/mL·h. No significant differences were observed between pharmacokinetic parameters at every administration route. Bioavailability evaluated was 10.4%. Compound 1 is metabolized to Compound 2 probably by enzymatic hydrolysis, and it showed a half-life of 9.24 h. With these properties, Compound 1 would be considered as a prodrug of Compound 2 with potential as an antidiabetic and anti dyslipidemic agent.

  20. Histories of terrestrial planets

    International Nuclear Information System (INIS)

    Benes, K.

    1981-01-01

    The uneven historical development of terrestrial planets - Mercury, Venus, Earth, Moon and Mars - is probably due to the differences in their size, weight and rotational dynamics in association with the internal planet structure, their distance from the Sun, etc. A systematic study of extraterrestrial planets showed that the time span of internal activity was not the same for all bodies. It is assumed that the initial history of all terrestrial planets was marked with catastrophic events connected with the overall dynamic development of the solar system. In view of the fact that the cores of small terrestrial bodies cooled quicker, their geological development almost stagnated after two or three thousand million years. This is what probably happened to the Mercury and the Moon as well as the Mars. Therefore, traces of previous catastrophic events were preserved on the surface of the planets. On the other hand, the Earth is the most metamorphosed terrestrial planet and compared to the other planets appears to be atypical. Its biosphere is significantly developed as well as the other shell components, its hydrosphere and atmosphere, and its crust is considerably differentiated. (J.P.)

  1. Structural diagenesis in Upper Carboniferous tight gas sandstones. Lessons learned from the Piesberg analog study

    Energy Technology Data Exchange (ETDEWEB)

    Steindorf, P.; Hoehne, M.; Becker, S.; Hilgers, C. [RWTH Aachen Univ. (Germany). Energy and Mineral Resources Group (EMR); Koehrer, B. [Wintershall Holding GmbH, Barnstorf (Germany)

    2013-08-01

    unconventional reservoir properties at a subseismic scale, considering both the alteration and evolution of pore space during diagenesis and the formation of structures. Combined with well-log and core data, uncertainties in 3D-reservoir modeling parameters and fluid migration pathways from seismic- to micro-scale of analogous subsurface tight gas reservoirs may be significantly reduced. (orig.)

  2. Comparative Study of the Effect of Baicalin and Its Natural Analogs on Neurons with Oxygen and Glucose Deprivation Involving Innate Immune Reaction of TLR2/TNFα

    Directory of Open Access Journals (Sweden)

    Hui-Ying Li

    2012-01-01

    Full Text Available This work is to study the baicalin and its three analogs, baicalin, wogonoside, and wogonin, on the protective effect of neuron from oxygen-glucose deprivation (OGD and toll-like receptor 2 (TLR2 expression in OGD damage. The results showed that baicalin and its three analogs did protect neurons from OGD damage and downregulated protein level of TLR2. D-Glucopyranosiduronic acid on site 7 in the structure played a core of cytotoxicity of these flavonoid analogs. The methoxyl group on carbon 8 of the structure had the relation with TLR2 protein expression, as well as the anti-inflammation. In addition, we detected caspase3 and antioxidation capability, to investigate the effect of four analogs on cell apoptosis and total antioxidation competence in OGD model.

  3. Functional analysis of protein N-myristoylation: Metabolic labeling studies using three oxygen-substituted analogs of myristic acid and cultured mammalian cells provide evidence for protein-sequence-specific incorporation and analog-specific redistribution

    International Nuclear Information System (INIS)

    Johnson, D.R.; Heuckeroth, R.O.; Gordon, J.I.; Cox, A.D.; Solski, P.A.; Buss, J.E.; Devadas, B.; Adams, S.P.; Leimgruber, R.M.

    1990-01-01

    Covalent attachment of myristic acid (C14:0) to the NH 2 -terminal glycine residue of a number of cellular, viral, and oncogene-encoded proteins is essential for full expression of their biological function. Substitution of oxygen for methylene groups in this fatty acid does not produce a significant change in chain length or stereochemistry but does result in a reduction in hydrophobicity. These heteroatom-containing analogs serve as alternative substrates for mammalian myristoyl-CoA: protein N-myristoyltransferase and offer the opportunity to explore structure/function relationships of myristate in N-myristoyltransferase proteins. The authors have synthesized three tritiated analogs of myristate with oxygen substituted for methylene groups at C6, C11, and C13. Metabolic labeling studies were performed with these compounds and (i) a murine myocyte cell line (BC 3 H1), (ii) a rat fibroblast cell that produces p60 v-src (3Xsrc), or (iii) NIH 3T3 cells that have been engineered to express a fusion protein consisting of an 11-residue myristoylation signal from the Rasheed sarcoma virus (RaSV) gag protein linked to c-Ha-ras with a Cys → Ser-186 mutation. Two-dimensional gel electrophoresis of membrane and soluble fractions prepared from cell lysates revealed different patterns of incorporation of the analogs into cellular N-myristoyl proteins. The demonstration that these analogs differ in the extent to which they are incorporated and in their ability to cause redistribution of any single protein suggests that they may also have sufficient selectivity to be of potential therapeutic value

  4. NMR studies of abasic sites in DNA duplexes: deoxyadenosine stacks into the helix opposite the cyclic analog of 2-deoxyribose

    International Nuclear Information System (INIS)

    Kalnik, M.W.; Chang, C.N.; Grollman, A.P.; Patel, D.J.

    1988-01-01

    Proton and phosphorus NMR studies are reported for the complementary d(C-A-T-G-A-G-T-A-C) x d(G-T-A-C-F-C-A-T-G) nonanucleotide duplex (designated AP/sub F/ 9-mer duplex) which contains a stable abasic site analog, F, in the center of the helix. This oligodeoxynucleotide contains a modified tetrahydrofuran moiety, isosteric with 2-deoxyribofuranose, which serves as a structural analog of a natural apurinic/apyrimidinic site. Exchangeable and nonexchangeable base and sugar protons, including those located at the abasic site, have been assigned in the complementary AP/sub F/ 9-mer duplex by recording and analyzing two-dimensional phase-sensitive NOESY data sets in H 2 O and D 2 O solution at low temperature (0 0 C). These studies indicate that A5 inserts into the helix opposite the abasic site F14 and stacks with flanking G4 x C15 and G6 x C13 Watson-Crick base pairs. Base-sugar proton NOE connectivities were measured through G4-A5-G6 on the unmodified strand and between the base protons of C15 and the sugar protons of the 5'-flanking residue F14 on the modified strand. These studies establish that all glycosidic torsion angles are anti and that the helix is right-handed at and adjacent to the abasic site in the AP/sub F/ 9-mer duplex. Two of the 16 phosphodiester groups exhibit phosphorus resonances outside the normal spectral dispersion indicative of altered torsion angles at two of the phosphate groups in the backbone of the AP/sub F/ 9-mer duplex

  5. Influence of ice and snow covers on the UV exposure of terrestrial microbial communities: dosimetric studies.

    Science.gov (United States)

    Cockell, Charles S; Rettberg, Petra; Horneck, Gerda; Wynn-Williams, David D; Scherer, Kerstin; Gugg-Helminger, Anton

    2002-08-01

    Bacillus subtilis spore biological dosimeters and electronic dosimeters were used to investigate the exposure of terrestrial microbial communities in micro-habitats covered by snow and ice in Antarctica. The melting of snow covers of between 5- and 15-cm thickness, depending on age and heterogeneity, could increase B. subtilis spore inactivation by up to an order of magnitude, a relative increase twice that caused by a 50% ozone depletion. Within the snow-pack at depths of less than approximately 3 cm snow algae could receive two to three times the DNA-weighted irradiance they would receive on bare ground. At the edge of the snow-pack, warming of low albedo soils resulted in the formation of overhangs that provided transient UV protection to thawed and growing microbial communities on the soils underneath. In shallow aquatic habitats, thin layers of heterogeneous ice of a few millimetres thickness were found to reduce DNA-weighted irradiances by up to 55% compared to full-sky values with equivalent DNA-weighted diffuse attenuation coefficients (K(DNA)) of >200 m(-1). A 2-mm snow-encrusted ice cover on a pond was equivalent to 10 cm of ice on a perennially ice covered lake. Ice covers also had the effect of stabilizing the UV exposure, which was often subject to rapid variations of up to 33% of the mean value caused by wind-rippling of the water surface. These data show that changing ice and snow covers cause relative changes in microbial UV exposure at least as great as those caused by changing ozone column abundance. Copyright 2002 Elsevier Science B.V.

  6. A study of the thermal behavior of terrestrial tridymite by continuous X-ray diffraction

    Science.gov (United States)

    Smelik, Eugene A.; Reeber, Robert R.

    1990-06-01

    Phase transition behavior of two types of terrestrial tridymite; crystals from Topaz Mountain in the Thomas Range of northwestern Utah and Smith Peak in Plumas County, California; were investigated. The Topaz Mtn. samples were characterized at room temperature using optical, X-ray diffraction (Debye-Scherrer, rotation, and Laue), and transmission electron microscopy (TEM) methods. Least-squares refinement of the powder data yielded an orthorhombic cell with a = 17.072 Å, b = 9.923 Å, and c = 16.291 Å. The tridymite is designated PO-2 (nomenclature of Nukui and Nakazawa 1980). This material is complexly twinned and has severe stacking disorder parallel to [001]. Additional X-ray experiments were performed on one Plumas County crystal and four Topaz Mtn. crystals during heating from room temperature to a minimum of 320° C with one run attaining a maximum temperature of 532° C. Crystal to crystal behavior was somewhat variable suggesting kinetic barriers to transition controlled by the detailed structural state of each crystal. The Laue results indicated that the transition behavior of these multiple twinned tridymites could be conveniently divided into two classes: discontinuous and continuous. The discontinuous diffraction effects were generally associated with major structural transitions. Continuous diffraction effects involved gradual structural distortions of the tridymite framework that occurred over discrete ranges of temperature. Upon cooling, many of the minor effects were not reversible while the major transitions were reversible with some temperature hysteresis. Comparison of initial and final diffraction patterns indicated that the starting and ending structures were very similar but not identical. From the five experiments, three distinct patterns emerged based on the major transitions observed: Type I behavior (Topaz Mtn.) characterized by three major changes at 175 187° C, 283 302° C, and 348 352° C, Type II behavior (Plumas Co.) characterized

  7. Byers Peninsula: A reference site for coastal, terrestrial and limnetic ecosystem studies in maritime Antarctica

    Science.gov (United States)

    Quesada, A.; Camacho, A.; Rochera, C.; Velázquez, D.

    2009-11-01

    This article describes the development of an international and multidisciplinary project funded by the Spanish Polar Programme on Byers Peninsula (Livingston Island, South Shetlands). The project adopted Byers Peninsula as an international reference site for coastal and terrestrial (including inland waters) research within the framework of the International Polar Year initiative. Over 30 scientists from 12 countries and 26 institutions participated in the field work, and many others participated in the processing of the samples. The main themes investigated were: Holocene changes in climate, using both lacustrine sediment cores and palaeo-nests of penguins; limnology of the lakes, ponds, rivers and wetlands; microbiology of microbial mats, ecology of microbial food webs and viral effects on aquatic ecosystems; ornithology, with investigations on a Gentoo penguin rookery ( Pygoscelis papua) as well as the flying ornithofauna; biocomplexity and life cycles of species from different taxonomic groups; analysis of a complete watershed unit from a landscape perspective; and human impacts, specifically the effect of trampling on soil characteristics and biota. Byers Peninsula offers many features as an international reference site given it is one of the largest ice-free areas in the Antarctic Peninsula region, it has a variety of different landscape units, and it hosts diverse aquatic ecosystems. Moreover, the Byers Peninsula is a hotspot for Antarctic biodiversity, and because of its high level of environmental protection, it has been very little affected by human activities. Finally, the proximity to the Spanish polar installations on Livingston Island and the experience derived from previous expeditions to the site make it logistically feasible as a site for ongoing monitoring and research.

  8. Analog model study of the ground-water basin of the Upper Coachella Valley, California

    Science.gov (United States)

    Tyley, Stephen J.

    1974-01-01

    An analog model of the ground-water basin of the upper Coachella Valley was constructed to determine the effects of imported water on ground-water levels. The model was considered verified when the ground-water levels generated by the model approximated the historical change in water levels of the ground-water basin caused by man's activities for the period 1986-67. The ground-water basin was almost unaffected by man's activities until about 1945 when ground-water development caused the water levels to begin to decline. The Palm Springs area has had the largest water-level decline, 75 feet since 1986, because of large pumpage, reduced natural inflow from the San Gorgonio Pass area, and diversions of natural inflows at Snow and Falls Creeks and Chino Canyon starting in 1945. The San Gorgonio Pass inflow had been reduced from about 18,000 acre-feet in 1986 to about 9,000 acre-feet by 1967 because of increased ground-water pumpage in the San Gorgonio Pass area, dewatering of the San Gorgonio Pass area that took place when the tunnel for the Metropolitan Water District of Southern California was drilled, and diversions of surface inflow at Snow and Falls Creeks. In addition, 1944-64 was a period of below-normal precipitation which, in part, contributed to the declines in water levels in the Coachella Valley. The Desert Hot Springs, Garnet Hill, and Mission Creek subbasins have had relatively little development; consequently, the water-level declines have been small, ranging from 5 to 15 feet since 1986. In the Point Happy area a decline of about 2 feet per year continued until 1949 when delivery of Colorado River water to the lower valley through the Coachella Canal was initiated. Since 1949 the water levels in the Point Happy area have been rising and by 1967 were above their 1986 levels. The Whitewater River subbasin includes the largest aquifer in the basin, having sustained ground-water pumpage of about 740,000 acre-feet from 1986 to 1967, and will probably

  9. Science Teachers' Analogical Reasoning

    Science.gov (United States)

    Mozzer, Nilmara Braga; Justi, Rosária

    2013-08-01

    Analogies can play a relevant role in students' learning. However, for the effective use of analogies, teachers should not only have a well-prepared repertoire of validated analogies, which could serve as bridges between the students' prior knowledge and the scientific knowledge they desire them to understand, but also know how to introduce analogies in their lessons. Both aspects have been discussed in the literature in the last few decades. However, almost nothing is known about how teachers draw their own analogies for instructional purposes or, in other words, about how they reason analogically when planning and conducting teaching. This is the focus of this paper. Six secondary teachers were individually interviewed; the aim was to characterize how they perform each of the analogical reasoning subprocesses, as well as to identify their views on analogies and their use in science teaching. The results were analyzed by considering elements of both theories about analogical reasoning: the structural mapping proposed by Gentner and the analogical mechanism described by Vosniadou. A comprehensive discussion of our results makes it evident that teachers' content knowledge on scientific topics and on analogies as well as their pedagogical content knowledge on the use of analogies influence all their analogical reasoning subprocesses. Our results also point to the need for improving teachers' knowledge about analogies and their ability to perform analogical reasoning.

  10. Structural parallels between terrestrial microbialites and Martian sediments: are all cases of `Pareidolia'?

    Science.gov (United States)

    Rizzo, Vincenzo; Cantasano, Nicola

    2017-10-01

    The study analyses possible parallels of the microbialite-known structures with a set of similar settings selected by a systematic investigation from the wide record and data set of images shot by NASA rovers. Terrestrial cases involve structures both due to bio-mineralization processes and those induced by bacterial metabolism, that occur in a dimensional field longer than 0.1 mm, at micro, meso and macro scales. The study highlights occurrence on Martian sediments of widespread structures like microspherules, often organized into some higher-order settings. Such structures also occur on terrestrial stromatolites in a great variety of `Microscopic Induced Sedimentary Structures', such as voids, gas domes and layer deformations of microbial mats. We present a suite of analogies so compelling (i.e. different scales of morphological, structural and conceptual relevance), to make the case that similarities between Martian sediment structures and terrestrial microbialites are not all cases of `Pareidolia'.

  11. Preliminary study of the 129I distribution in environment of La Hague reprocessing plant with the help of a terrestrial moss: Homalotecium sericeum. Study report

    International Nuclear Information System (INIS)

    1999-01-01

    The preliminary study of the 129 I distribution has allowed to underline the limits of use of a Homalotecium sericeum type terrestrial moss as biological indicator. However, this preliminary study allowed all the same to give a spatial distribution of this radioelement around La Hague reprocessing plant (source term) that underlines the existence of four geographic areas in function of collected activities. The levels are generally under 99 Bq/kg dry. It is recommended to improve the knowledge that we can have of transfers and quantity of iodine 129 from the marine environment to the terrestrial environment, but also, the one that we can have of factors able to modify the spatial distribution of this radionuclide. (N.C.)

  12. Assessment of the importance of acidic fogwater and cloudwater in affecting terrestrial vegetation: Some important case studies

    Energy Technology Data Exchange (ETDEWEB)

    Irving, P.M.; Eagar, C. (National Acid Precipitation Assessment Program, Washington, DC (USA). Office of the Director of Research; Forest Service, Broomall, PA (USA). Northeastern Forest Experiment Station)

    1989-01-01

    The purpose of this paper is to present some examples of terrestrial effects of concern as case studies to demonstrate the methodology to be used for answering questions of the NAPAP Integrated Assessment. The two examples presented, one each for forestry and crops, represent what is probably the worst case'' for possible acidic rain effects on crops and forests. Both examples revolve around hypotheses centering on stress from acidic fogwater or cloudwater. Because it is likely that additional information will become available prior to the publication of the Integrated Assessment, it should be understood that the analyses and interpretations presented on the following pages are subject to change when NAPAP publishes its final Assessment in 1990. 76 refs., 3 tabs.

  13. Phytopharmacology of Tribulus terrestris.

    Science.gov (United States)

    Shahid, M; Riaz, M; Talpur, M M A; Pirzada, T

    2016-01-01

    Tribulus terrestris is an annual herb which belongs to the Zygophyllaceae family. This plant has been used in traditional medicine for the treatment of various diseases for hundreds of decades. The main active phytoconstituents of this plant include flavonoids, alkaloids, saponins, lignin, amides, and glycosides. The plant parts have different pharmacological activities including aphrodisiac, antiinflammatory, antimicrobial and antioxidant potential. T. terrestris is most often used for infertility and loss of libido. It has potential application as immunomodulatory, hepatoprotective, hypolipidemic, anthelmintic and anticarcinogenic activities. The aim of the present article is to create a database for further investigation of the phytopharmacological properties of this plant to promote research. This study will definitely help to confirm its traditional use along with its value-added utility, eventually leading to higher revenues from the plant.

  14. Enantioselective syntheses and biological studies of aeruginosin 298-A and its analogs: application of catalytic asymmetric phase-transfer reaction.

    Science.gov (United States)

    Fukuta, Yuhei; Ohshima, Takashi; Gnanadesikan, Vijay; Shibuguchi, Tomoyuki; Nemoto, Tetsuhiro; Kisugi, Takaya; Okino, Tatsufumi; Shibasaki, Masakatsu

    2004-04-13

    Aeruginosin 298-A was isolated from the freshwater cyanobacterium Microcystis aeruginosa (NIES-298) and is an equipotent thrombin and trypsin inhibitor. A variety of analogs were synthesized to gain insight into the structure-activity relations. We developed a versatile synthetic process for aeruginosin 298-A as well as several attractive analogs, in which all stereocenters were controlled by catalytic asymmetric phase-transfer reaction promoted by two-center asymmetric catalysts and catalytic asymmetric epoxidation promoted by a lanthanide-BINOL complex. Furthermore, serine protease inhibitory activities of aeruginosin 298-A and its analogs were examined.

  15. Molecular modeling of fentanyl analogs

    Directory of Open Access Journals (Sweden)

    LJILJANA DOSEN-MICOVIC

    2004-11-01

    Full Text Available Fentanyl is a highly potent and clinically widely used narcotic analgesic. A large number of its analogs have been synthesized, some of which (sufentanil and alfentanyl are also in clinical use. Theoretical studies, in recent years, afforded a better understanding of the structure-activity relationships of this class of opiates and allowed insight into the molecular mechanism of the interactions of fentanyl analogs with their receptors. An overview of the current computational techniques for modeling fentanyl analogs, their receptors and ligand-receptor interactions is presented in this paper.

  16. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  17. The "Goldberg Variations" and Ian McEwan's Saturday - a study of interdisciplinary analogies

    OpenAIRE

    Lykka, Inga Hild

    2014-01-01

    This thesis examines the musical influence on Ian McEwan’s fiction, in particular that of the Goldberg Variations’ influence on his novel Saturday. This involves an interdisciplinary analysis that compares the two arts, and sheds light on both possibilities and difficulties with regards to which musical features are likely to occur in literature or not. The analysis is founded on previous interdisciplinary studies of music and literature in general, studies of representations of the Goldberg ...

  18. Analogies in the microscopic behavior of superfluid and classical helium studied by neturon scattering [Analogieen in het microscopische gedrag van superfluid en klassiek helium

    NARCIS (Netherlands)

    Crevecoeur, R.M.

    1996-01-01

    In this thesis we have presented the results of a neutron scattering study of the analogies in the microscopic behavior of superfluid and classical helium. Therefore we performed both neutron-diffraction experiments to study the structure and inelastic neutron scattering experiments to study the

  19. The natural analogous study of the migration of radionuclides in granite for nuclear waste disposal

    International Nuclear Information System (INIS)

    Yu Jinsheng

    1995-01-01

    Granite is one of the optimum types of surround rock for radioactive waste geological disposal. The study of natural analogues could provide very useful reference materials for selecting validating and designing site of repository in granite. The basic research substances are as follows: the fracture system and the circulation paths of the fluid, the hydrothermal alteration, the evolution of hydrothermal solution, the U, Th, REE element geochemical behaviours, the secondary mineral phases and its retention capacity for the concerned radioactive nuclides and the mass transfer modelling

  20. Automatic control of scale range applied for analog study of reactor kinetics

    International Nuclear Information System (INIS)

    Sergent, O.; Tellier, N.

    1967-01-01

    We study the response of a reactor, initially in a sub-critical state, for linear release of reactivity obeying to the following criteria, a rod drop comes in 10 seconds after the moment when the neutron power becomess equal to 10 -3 times the nominal power. We are interested in the maximum reactivity reached and in the energy released during the power excursion. For the power varying in a range from 1 to 10 10 we have used the method of automatic change scale which was installed and described in a previous report [fr

  1. Ring-testing and field-validation of a terrestrial model ecosystem TME) - An instrument for testing potentially harmful substances: conceptual approach and study design.

    NARCIS (Netherlands)

    Knacker, T.; van Gestel, C.A.M.; Jones, S.E.; Soares, A.M.V.M.; Schallnass, H.-J.; Förster, B.; Edwards, C.A.

    2004-01-01

    During spring and summer 1999 a ring-test and field-validation study with an open, intact Terrestrial Model Ecosystem (TME) was conducted at four different European sites (Amsterdam, The Netherlands; Bangor, U.K.; Coimbra, Portugal; Flörsheim, Germany). The objective of the study was to establish a

  2. Study of the electron transfer in analog compounds of the Prussia blue

    International Nuclear Information System (INIS)

    Romero V, S.; Damaso C, L.F.; Reguera R, E.; Yee M, H.T.

    2006-01-01

    As answer to the necessity of the search of new nano structured materials, the present work was carried out that it studies the electron transfer in compound similar of the Prussia blue (CAAP), which are representative molecular materials, because its chromophore, magnetic, and electric properties, depend mainly on the processes that are made in their levels or orbital energy. It is known that these made up with octahedra symmetry that its are presented in form of powders, suffer processes of electron transfer when its are exposed to external stimulation by means of light (embracing the regions from the ultraviolet one until the infrared in the electromagnetic spectrum), because they are made up of mixed valency. To know that types of electronic transfers are those that are made in the study materials, 4 series of CAAP its were synthesized by the method of mixtures of aqueous solutions: M[Fe +3 CN) 6 ] 2 nH 2 O, M[Cr +3 (CN) 6 ] 2 nH 2 O, M[Mn +3 (CN) 6 ] 3 nH 2 O y M[Co +3 (CN) 6 ] 3 nH 2 O, and later on studied by means of the electron spectroscopy technique with a UV-SENSE spectrophotometer (Perkin-Elmer) in or n range of work of 250 to 1100 nm. Because to discuss the electronic structures of any compound, it is required the calculation of the energy levels, they took like reference the data tabulated by John Alexander and Harry Gray calculated by the modified theoretical approach of Wolfsberg-Helmhoz. When comparing the obtained spectra with the theoretical data, it was concludes that in the CAAP, its are carried out electronic transfers among orbital molecular metallic of the type d → d, and load transfer (TC) among orbital molecular of the ligand and metal. When being carried out a load transfer in the CAAP that initially are made up of under-spin these its are photoinduced to an excited state of high spin. In consequence it is possible to vary the interactions among the metals of transition of the CAAP and the ligands, allowing the extension of coordinated

  3. Characterizing Earth Analogs in Reflected Light: Atmospheric Retrieval Studies for Future Space Telescopes

    Science.gov (United States)

    Feng, Y. Katherina; Robinson, Tyler D.; Fortney, Jonathan J.; Lupu, Roxana E.; Marley, Mark S.; Lewis, Nikole K.; Macintosh, Bruce; Line, Michael R.

    2018-05-01

    Space-based high-contrast imaging mission concepts for studying rocky exoplanets in reflected light are currently under community study. We develop an inverse modeling framework to estimate the science return of such missions given different instrument design considerations. By combining an exoplanet albedo model, instrument noise model, and ensemble Markov chain Monte Carlo sampler, we explore retrievals of atmospheric and planetary properties for Earth twins as a function of signal-to-noise ratio (S/N) and resolution (R). Our forward model includes Rayleigh-scattering, single-layer water clouds with patchy coverage, and pressure-dependent absorption due to water vapor, oxygen, and ozone. We simulate data at R = 70 and 140 from 0.4 to 1.0 μm with S/N = 5, 10, 15, and 20 at 550 nm (i.e., for HabEx/LUVOIR-type instruments). At these same S/Ns, we simulate data for WFIRST paired with a starshade, which includes two photometric points between 0.48 and 0.6 μm and R = 50 spectroscopy from 0.6 to 0.97 μm. Given our noise model for WFIRST-type detectors, we find that weak detections of water vapor, ozone, and oxygen can be achieved with observations with at least R = 70/S/N = 15 or R = 140/S/N = 10 for improved detections. Meaningful constraints are only achieved with R = 140/S/N = 20 data. The WFIRST data offer limited diagnostic information, needing at least S/N = 20 to weakly detect gases. Most scenarios place limits on planetary radius but cannot constrain surface gravity and, thus, planetary mass.

  4. Analog elements for transuranic chemistries

    International Nuclear Information System (INIS)

    Weimer, W.C.

    1982-01-01

    The analytical technique for measuring trace concentrations of the analog rare earth elements has been refined for optimal detection. The technique has been used to determine the rare earth concentrations in a series of geological and biological materials, including samples harvested from controlled lysimeter investigations. These studies have demonstrated that any of the trivalent rare earth elements may be used as analog elements for the trivalent transuranics, americium and curium

  5. CMOS Analog IC Design: Fundamentals

    OpenAIRE

    Bruun, Erik

    2018-01-01

    This book is intended for use as the main textbook for an introductory course in CMOS analog integrated circuit design. It is aimed at electronics engineering students who have followed basic courses in mathematics, physics, circuit theory, electronics and signal processing. It takes the students directly from a basic level to a level where they can start working on simple analog IC design projects or continue their studies using more advanced textbooks in the field. A distinct feature of thi...

  6. Rhetoric and analogies

    OpenAIRE

    Aragonès, Enriqueta; Gilboa, Itzhak; Postlewaite, Andrew; Schmeidler, David; Universitat Autònoma de Barcelona. Unitat de Fonaments de l'Anàlisi Econòmica; Universitat Autònoma de Barcelona. Institut d'Anàlisi Econòmica

    2013-01-01

    The art of rhetoric may be defined as changing other people's minds (opinions, beliefs) without providing them new information. One tech- nique heavily used by rhetoric employs analogies. Using analogies, one may draw the listener's attention to similarities between cases and to re-organize existing information in a way that highlights certain reg- ularities. In this paper we offer two models of analogies, discuss their theoretical equivalence, and show that finding good analogies is a com- p...

  7. Numerical study of time domain analogy applied to noise prediction from rotating blades

    Science.gov (United States)

    Fedala, D.; Kouidri, S.; Rey, R.

    2009-04-01

    Aeroacoustic formulations in time domain are frequently used to model the aerodynamic sound of airfoils, the time data being more accessible. The formulation 1A developed by Farassat, an integral solution of the Ffowcs Williams and Hawkings equation, holds great interest because of its ability to handle surfaces in arbitrary motion. The aim of this work is to study the numerical sensitivity of this model to specified parameters used in the calculation. The numerical algorithms, spatial and time discretizations, and approximations used for far-field acoustic simulation are presented. An approach of quantifying of the numerical errors resulting from implementation of formulation 1A is carried out based on Isom's and Tam's test cases. A helicopter blade airfoil, as defined by Farassat to investigate Isom's case, is used in this work. According to Isom, the acoustic response of a dipole source with a constant aerodynamic load, ρ0c02, is equal to the thickness noise contribution. Discrepancies are observed when the two contributions are computed numerically. In this work, variations of these errors, which depend on the temporal resolution, Mach number, source-observer distance, and interpolation algorithm type, are investigated. The results show that the spline interpolating algorithm gives the minimum error. The analysis is then extended to Tam's test case. Tam's test case has the advantage of providing an analytical solution for the first harmonic of the noise produced by a specific force distribution.

  8. Halophilic-Psychrophilic Bacteria from Tirich Mir Glacier, Pakistan, as Potential Candidate for Astrobiological Studies

    Science.gov (United States)

    Rafiq, M. R.; Anesio, A. M. A.; Hayat, M. H.; Zada, S. Z.; Sajjad, W. S.; Shah, A. A. S.; Hasan, F. H.

    2016-09-01

    Hindu Kush, Karakoram, and Himalaya region is referred to as 'third pole' and could be suitable as a terrestrial analog of Mars and increased possibility of finding polyextremophiles. Study is focused on halophilic psychrophiles.

  9. Studies of volatiles and organic materials in early terrestrial and present-day outer solar system environments

    Science.gov (United States)

    Sagan, Carl; Thompson, W. Reid; Chyba, Christopher F.; Khare, B. N.

    1991-01-01

    A review and partial summary of projects within several areas of research generally involving the origin, distribution, chemistry, and spectral/dielectric properties of volatiles and organic materials in the outer solar system and early terrestrial environments are presented. The major topics covered include: (1) impact delivery of volatiles and organic compounds to the early terrestrial planets; (2) optical constants measurements; (3) spectral classification, chemical processes, and distribution of materials; and (4) radar properties of ice, hydrocarbons, and organic heteropolymers.

  10. Study and achievement of a digital-analog-divider; Etude et realisation d'un diviseur-analogique-numerique

    Energy Technology Data Exchange (ETDEWEB)

    Petin, A [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1969-04-01

    This apparatus is designed to give directly, in digital form, the value of the ratio Vt1/V2 two analog voltages. It consists essentially of an analog-digital coder operating by successive weighing; the comparison voltage is made proportional to the divider V2 in the coder. The input dynamics are such that the voltages Vi and V2 are all in the range -50 mV to -5 V. Each of the circuits has an input impedance of about 10 K{omega}. As for the quotient, it is a binary number given in series and parallel form; it is made up of 8 bits, this giving a change of 1/16 to 16 per jump of 1/16 in the zone where the accuracy is highest (V2 {>=} 800 mV). The time required for a division is, at best, 15 {mu}sec. During the time of calculation, the voltages V{sub 1} and V{sub 2} should not vary by more than 1 per cent and 0.5 per cent respectively. The theory of the system and the investigation of a synoptic diagram, the study of the circuits and the actual construction are presented. (author) [French] Cet appareil est destine a fournir directement sous forme numerique la valeur du rapport V1/V2 de deux tensions analogiques. Il est constitue essentiellement d'un codeur analogique-numerique fonctionnant par pesees successives dans lequel la tension de reference est rendue proportionnelle au diviseur V2. La dynamique d'entree est telle que les tensions V1 et V2 peuvent etre comprises dans l'intervalle -50 mV a -5 V. Chacune des voies presente une impedance d'entree d'environ 10 K{omega}. En ce qui concerne le quotient, c'est un nombre binaire delivre sous les formes serie et parallele ; il est compose de 8 bits, ce qui donne une variation de 1/16 a 16 par bond de 1/16 dans la zone de meilleure precision (V2 {>=} 800 mV). Le temps necessaire pour effectuer la division est au mieux de 15 {mu}s. Durant le temps de calcul les tensions V{sub 1} et V{sub 2} ne doivent pas varier respectivement de plus de 1 pour cent et 0.5 pour cent. Apres avoir etabli la theorie du systeme, les

  11. Study and achievement of a digital-analog-divider; Etude et realisation d'un diviseur-analogique-numerique

    Energy Technology Data Exchange (ETDEWEB)

    Petin, A. [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1969-04-01

    This apparatus is designed to give directly, in digital form, the value of the ratio Vt1/V2 two analog voltages. It consists essentially of an analog-digital coder operating by successive weighing; the comparison voltage is made proportional to the divider V2 in the coder. The input dynamics are such that the voltages Vi and V2 are all in the range -50 mV to -5 V. Each of the circuits has an input impedance of about 10 K{omega}. As for the quotient, it is a binary number given in series and parallel form; it is made up of 8 bits, this giving a change of 1/16 to 16 per jump of 1/16 in the zone where the accuracy is highest (V2 {>=} 800 mV). The time required for a division is, at best, 15 {mu}sec. During the time of calculation, the voltages V{sub 1} and V{sub 2} should not vary by more than 1 per cent and 0.5 per cent respectively. The theory of the system and the investigation of a synoptic diagram, the study of the circuits and the actual construction are presented. (author) [French] Cet appareil est destine a fournir directement sous forme numerique la valeur du rapport V1/V2 de deux tensions analogiques. Il est constitue essentiellement d'un codeur analogique-numerique fonctionnant par pesees successives dans lequel la tension de reference est rendue proportionnelle au diviseur V2. La dynamique d'entree est telle que les tensions V1 et V2 peuvent etre comprises dans l'intervalle -50 mV a -5 V. Chacune des voies presente une impedance d'entree d'environ 10 K{omega}. En ce qui concerne le quotient, c'est un nombre binaire delivre sous les formes serie et parallele ; il est compose de 8 bits, ce qui donne une variation de 1/16 a 16 par bond de 1/16 dans la zone de meilleure precision (V2 {>=} 800 mV). Le temps necessaire pour effectuer la division est au mieux de 15 {mu}s. Durant le temps de calcul les tensions V{sub 1} et V{sub 2} ne doivent pas varier respectivement de plus de 1 pour cent et 0.5 pour cent. Apres avoir etabli la

  12. Potential of Probing the Lunar Regolith using Rover-Mounted Ground Penetrating Radar: Moses Lake Dune Field Analog Study

    Science.gov (United States)

    Horz, F.; Heggy, E.; Fong, T.; Kring, D.; Deans, M.; Anglade, A.; Mahiouz, K.; Bualat, M.; Lee, P.; Bluethmann, W.

    2009-01-01

    Probing radars have been widely recognized by the science community to be an efficient tool to explore lunar subsurface providing a unique capability to address several scientific and operational issues. A wideband (200 to 1200 MHz) Ground Penetrating Radar (GPR) mounted on a surface rover can provide high vertical resolution and probing depth from few tens of centimeters to few tens of meters depending on the sounding frequency and the ground conductivity. This in term can provide a better understand regolith thickness, elemental iron concentration (including ilmenite), volatile presence, structural anomalies and fracturing. All those objectives are of important significance for understanding the local geology and potential sustainable resources for future landing sites in particular exploring the thickness, structural heterogeneity and potential volatiles presence in the lunar regolith. While the operation and data collection of GPR is a straightforward case for most terrestrial surveys, it is a challenging task for remote planetary study especially on robotic platforms due to the complexity of remote operation in rough terrains and the data collection constrains imposed by the mechanical motion of the rover and limitation in data transfer. Nevertheless, Rover mounted GPR can be of great support to perform systematic subsurface surveys for a given landing site as it can provide scientific and operational support in exploring subsurface resources and sample collections which can increase the efficiency of the EVA activities for potential human crews as part of the NASA Constellation Program. In this study we attempt to explore the operational challenges and their impact on the EVA scientific return for operating a rover mounted GPR in support of potential human activity on the moon. In this first field study, we mainly focused on the ability of GPR to support subsurface sample collection and explore shallow subsurface volatiles.

  13. Rockfall monitoring by Terrestrial Laser Scanning - case study of the basaltic rock face at Castellfollit de la Roca (Catalonia, Spain)

    Science.gov (United States)

    Abellán, A.; Vilaplana, J. M.; Calvet, J.; García-Sellés, D.; Asensio, E.

    2011-03-01

    This case study deals with a rock face monitoring in urban areas using a Terrestrial Laser Scanner. The pilot study area is an almost vertical, fifty meter high cliff, on top of which the village of Castellfollit de la Roca is located. Rockfall activity is currently causing a retreat of the rock face, which may endanger the houses located at its edge. TLS datasets consist of high density 3-D point clouds acquired from five stations, nine times in a time span of 22 months (from March 2006 to January 2008). The change detection, i.e. rockfalls, was performed through a sequential comparison of datasets. Two types of mass movement were detected in the monitoring period: (a) detachment of single basaltic columns, with magnitudes below 1.5 m3 and (b) detachment of groups of columns, with magnitudes of 1.5 to 150 m3. Furthermore, the historical record revealed (c) the occurrence of slab failures with magnitudes higher than 150 m3. Displacements of a likely slab failure were measured, suggesting an apparent stationary stage. Even failures are clearly episodic, our results, together with the study of the historical record, enabled us to estimate a mean detachment of material from 46 to 91.5 m3 year-1. The application of TLS considerably improved our understanding of rockfall phenomena in the study area.

  14. Analog and hybrid computing

    CERN Document Server

    Hyndman, D E

    2013-01-01

    Analog and Hybrid Computing focuses on the operations of analog and hybrid computers. The book first outlines the history of computing devices that influenced the creation of analog and digital computers. The types of problems to be solved on computers, computing systems, and digital computers are discussed. The text looks at the theory and operation of electronic analog computers, including linear and non-linear computing units and use of analog computers as operational amplifiers. The monograph examines the preparation of problems to be deciphered on computers. Flow diagrams, methods of ampl

  15. Structured Analog CMOS Design

    CERN Document Server

    Stefanovic, Danica

    2008-01-01

    Structured Analog CMOS Design describes a structured analog design approach that makes it possible to simplify complex analog design problems and develop a design strategy that can be used for the design of large number of analog cells. It intentionally avoids treating the analog design as a mathematical problem, developing a design procedure based on the understanding of device physics and approximations that give insight into parameter interdependences. The proposed transistor-level design procedure is based on the EKV modeling approach and relies on the device inversion level as a fundament

  16. Studies toward the unique pederin family member psymberin: full structure elucidation, two alternative total syntheses, and analogs.

    Science.gov (United States)

    Feng, Yu; Jiang, Xin; De Brabander, Jef K

    2012-10-17

    Two synthetic approaches to psymberin have been accomplished. A highly convergent first generation synthesis led to the complete stereochemical assignment and demonstrated that psymberin and irciniastatin A are identical compounds. This synthesis featured a diastereoselective aldol coupling between the aryl fragment and a central tetrahydropyran core and a novel one-pot procedure to convert an amide, via intermediacy of a sensitive methyl imidate, to the N-acyl aminal reminiscent of psymberin. The highlights of the second generation synthesis include an efficient iridium-catalyzed enantioselective bisallylation of neopentyl glycol and a stepwise Sonogashira coupling/cycloisomerization/reduction sequence to construct the dihydroisocoumarin unit. The two synthetic avenues were achieved in 17-18 steps (longest linear sequence, ~14-15 isolations) from 3 fragments prepared in 7-8 (first generation) and 3-8 (second generation) steps each. This convergent approach allowed for the preparation of sufficient amounts of psymberin (~ 0.5 g) for follow-up biological studies. Meanwhile, our highly flexible strategy enabled the design and synthesis of multiple analogs, including a psymberin-pederin hybrid, termed psympederin, that proved crucial to a comprehensive understanding of the chemical biology of psymberin and related compounds that will be described in a subsequent manuscript.

  17. Bacterial Peptide Deformylase Inhibition of Tetrazole-Substituted Biaryl Acid Analogs: Synthesis, Biological Evaluations, and Molecular Docking Study.

    Science.gov (United States)

    Khan, Firoz A Kalam; Patil, Rajendra H; Patil, Manjiri; Arote, Rohidas; Shinde, Devanand B; Sangshetti, Jaiprakash N

    2016-12-01

    The synthesis and screening of tetrazole-substituted biaryl acid analogs 7a-l as bacterial peptide deformylase (PDF) enzyme inhibitors is reported. The compounds 7e (IC 50 value = 5.50 μM) and 7g (IC 50 value = 7.25 μM) showed good PDF inhibition activity. The compounds 7e (MIC range = 10.75-11.66 μg/mL) and 7g (MIC range = 8.91-12.83 μg/mL) also showed potent antibacterial activity when compared with the standard ciprofloxacin (MIC range = 25-50 μg/mL). Thus, the active derivatives were not only potent PDF enzyme inhibitors but also efficient antibacterial agents. In order to gain more insight into the binding mode of the compounds with the PDF enzyme, the most active compounds 7e and 7g, the moderately active compound 7k, and the least active compound 7h were docked against the PDF enzyme of Escherichia coli. The docking study of the most active compounds 7e and 7g against the PDF enzyme exhibited good binding properties. Hence, we believe our synthesized compounds 7a-l could serve as reservoir for bacterial PDF inhibitor development. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Antibacterial activity of Tribulus terrestris and its synergistic effect with Capsella bursa-pastoris and Glycyrrhiza glabra against oral pathogens: an in-vitro study.

    Science.gov (United States)

    Soleimanpour, Saman; Sedighinia, Fereshteh Sadat; Safipour Afshar, Akbar; Zarif, Reza; Ghazvini, Kiarash

    2015-01-01

    In this study, antimicrobial activities of an ethanol extract of Tribulus terrestris aloneand in combination with Capsella bursa-pastoris and Glycyrrhiza glabra were examined in vitro against six pathogens namely Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, Enterococcus faecalis Staphylococcus aureus, and Escherichia coli. Antibacterial activities of the extracts were examined using disc and well diffusion methods and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ethanol extracts were determined against these microorganisms using agar and broth dilution methods. Chlorhexidine was used as positive control. Tribulus terrestris extract exhibited good antibacterial activity against all bacteria. Antibacterial activity of mixed extract was evaluated and exhibited that mixed extract was more effective against all bacteria than any of the cases alone which indicates the synergistic effect between these three extracts (p˂0.05). No strain showed resistance against these extracts. In agar dilution, Tribulus terrestris exhibited MIC values ranging from 35.0 to 20.0 mg/ml and mixed extract showed MIC values ranging from 12.5 to 5.0 mg/ml. The results of broth dilution method were consistent with the findings of the agar dilution method. This in-vitro study was a preliminary evaluation of antibacterial activity of the plants. It provided scientific evidence to support uses of T. terrestris and its mixture with C. bursa-pastoris and G. glabra for the treatment of oral infections. In-vivo studies are also required to better evaluate the effect of these extracts.

  19. Analogical proportions: another logical view

    Science.gov (United States)

    Prade, Henri; Richard, Gilles

    This paper investigates the logical formalization of a restricted form of analogical reasoning based on analogical proportions, i.e. statements of the form a is to b as c is to d. Starting from a naive set theoretic interpretation, we highlight the existence of two noticeable companion proportions: one states that a is to b the converse of what c is to d (reverse analogy), while the other called paralogical proportion expresses that what a and b have in common, c and d have it also. We identify the characteristic postulates of the three types of proportions and examine their consequences from an abstract viewpoint. We further study the properties of the set theoretic interpretation and of the Boolean logic interpretation, and we provide another light on the understanding of the role of permutations in the modeling of the three types of proportions. Finally, we address the use of these proportions as a basis for inference in a propositional setting, and relate it to more general schemes of analogical reasoning. The differences between analogy, reverse-analogy, and paralogy is still emphasized in a three-valued setting, which is also briefly presented.

  20. A study of the terrestrial thermosphere by remote sensing of OI dayglow in the far and extreme ultraviolet

    International Nuclear Information System (INIS)

    Cotton, D.M.

    1991-01-01

    The upper region of the Earth's atmosphere, the thermosphere, is a key part of the coupled solar-terrestrial system. An important method of obtaining information in the this region is through analysis of radiation excited through the interactions of the thermosphere with solar ionizing, extreme and far ultraviolet radiation. This dissertation presents one such study by the remote sensing of OI in the far and extreme ultraviolet dayglow. The research program included the development construction, and flight of a sounding rocket spectrometer to test this current understanding of the excitation and transport mechanisms of the OI 1356, 1304, 1027, and 989 angstrom emissions. This data set was analyzed using current electron and radiative transport models with the purpose of checking the viability of OI remote sensing; that is, whether existing models and input parameters are adequate to predict these detailed measurements. From discrepancies between modeled and measured emissions, inferences about these input parameters were made. Among other things, the data supports a 40% optically thick cascade contribution to the 1304 angstrom emission. From upper lying states corresponding to 1040, 1027 and 989 angstrom about half of this cascade has been accounted for in this study. There is also evidence that the Lyman β airglow from the geo-corona contributes a significant proportion (30-50%) to the OI 1027 angstrom feature. Furthermore, the photoelectron contribution to the 1027 angstrom feature appears to be underestimated in the current models by a factor of 20

  1. Detailed Study of the Formation of Sugar Derivatives Produced from the UV Irradiation of Astrophysical Ice Analogs

    Science.gov (United States)

    Nuevo, Michel; Cooper, George; Saunders, John; Buffo, Christina E.; Materese, Christopher K.; Sandford, Scott A.

    2018-01-01

    Carbonaceous meteorites such as Murchison contain a large variety of organic compounds of astrobiological interest such as amino acids, other amphiphilic compounds, functionalized nitrogen heterocycles (including nucleobases), functionalized polycylic aromatic hydro-carbons (including quinones), and sugar derivatives. The presence of such a broad variety of organics in meteorites strongly suggests that molecules essential to life can form abiotically under astrophysical conditions. This hypothesis is strongly supported by laboratory studies in which astrophysical ice analogs (i.e., mixtures of H2O, CO, CO2, CH3OH, CH4, NH3, etc.) are subjected to ultraviolet (UV) irradiation at low temperature (less than 15 K) to simulate cold interstellar environments. These studies have shown that the organic residues recovered at room temperature after irradiation contain organic compounds that are very similar to those found in meteorites. No systematic search for the presence of sugar derivatives in laboratory residues had been carried out until the recent detection of ribose, the sugar of RNA, as well as other sugars, sugar alcohols, and sugar acids in one residue produced from the UV irradiation of an ice mixture containing H2O, CH3OH, and NH3 at 80 K. In this work, we present a detailed study of the formation of sugar derivatives contained in organic residues that are produced from the UV irradiation of ice mixtures of different starting compositions (H2O, CH3OH, CO, CO2, and/or NH3) at less than 15 K. While the presence of sugar alcohols, sugars, and sugar acids-in some cases with up to 6 carbon atoms-could be confirmed in all these residues, their distribution was shown to vary with the composition of the starting ices. In particular, only a few ices result in the formation of sugar derivatives displaying a distribution that resembles that of meteorites, in which sugar alcohols and sugar acids are very abundant while sugars are mostly absent.

  2. Using an Ongoing Study of Terrestrial Plant Response to Ultraviolet Radiation in Project ALERT

    Science.gov (United States)

    Condon, Estelle; Skiles, J. W.; Seitz, Jeffery C.; Dantoni, Hector L.

    1998-01-01

    The ALERT (Augmented Learning Environment for Renewable Teaching) Project is a cooperative California-based program with two main partners: California State University (CSU) geoscience and education departments and two NASA Centers, the Jet Propulsion Laboratory (JPL) in Pasadena and the Ames Research Center (ARC) in Mountain View. This paper presents an example of how a NASA research effort can be used in the undergraduate classroom. A study, now in the fourth year, subjects test plants to exposures of varying solar ultraviolet (UV) radiation (280 - 340 nm); a full solar UV exposure, a solar UV exposure less about 14% of ambient UV flux, and a UV-blocked regime. This experiment is simple in that only modest amounts of expense are required yet it is elegant since only one variable, UV-flux is involved. The experiment lends itself to teaching several of the Earth Sciences because it uses information from botany, taxonomy, and ecology. Aspects of physics are inherent in the study since portions of the electromagnetic spectrum are studied. Further, since only one of many variables are manipulated, UV flux, the study demonstrates how the scientific method is used in formulating and testing hypotheses. Based on the ALERT experience this summer, this study will be implemented at a CSU campus with the expectation that it will serve as a pedagogical tool and where it will involve students in actual research.

  3. Study of cosmic rays reveals secrets of solar-terrestrial science

    Science.gov (United States)

    Jokipii, J. R.

    For many years cosmic rays provided the most important source of energetic particles for studies of subatomic physics. Today, cosmic rays are being studied as a natural phenomenon that can tell us much about both the Earth's environment in space and distant astrophysical processes. Cosmic rays are naturally occurring energetic particles—mainly ions—with kinetic energies extending from just above thermal energies to more than 1020 electron volts (eV). They constantly bombard the Earth from all directions, with more than 1018 particles having energies >1 MeV striking the top of the Earth's atmosphere each second. Figure 1 illustrates the continuous cosmic ray energy spectrum.

  4. Historical Photogrammetry and Terrestrial Laser Scanning for the 3d Virtual Reconstruction of Destroyed Structures: a Case Study in Italy

    Science.gov (United States)

    Bitelli, G.; Dellapasqua, M.; Girelli, V. A.; Sbaraglia, S.; Tinia, M. A.

    2017-05-01

    The current dramatic episodes of destruction of archaeological sites have again highlighted the problem of the safeguarding the threatened heritage and, if possible, recovering those damaged by all the armed conflicts of the past. The historical photogrammetry offers the possibility to recover a posteriori the geometrical and material properties of destroyed structures, reconstructing their 3D model to document, study and maintain their memory, until to support their real anastylosis. The presented work is about the 3D reconstruction of the civic tower of the little town of Sant'Alberto, near the city of Ravenna, Italy. The tower, as a symbol of resistance and pride of the town's population, was destroyed in December 1944 by German troops in retaliation, when they were forced to leave the area. A city committee has subsequently collected all the historical evidence concerning the tower, including a series of photographic images that can be used for the photogrammetric reconstruction; the images calibration and orientation have been solved using the geometric information derived by a terrestrial laser scanner survey realized in the area where the tower was originally located. Despite the scarcity and very poor quality of the available images, the conducted photogrammetric procedure has allowed a complete and qualitatively satisfying object reconstruction, also thanks to the use of geometric constraint tools offered by the chosen software. The integration between the obtained model of the old tower and the 3D TLS survey of the square made it possible to reconstruct the ancient situation of the area.

  5. Assessment of the Effects of Urban Expansion on Terrestrial Carbon Storage: A Case Study in Xuzhou City, China

    Directory of Open Access Journals (Sweden)

    Cheng Li

    2018-02-01

    Full Text Available Carbon storage is closely connected to the productivities and climate regulation capacities of ecosystems. Assessing the effects of urban expansion on carbon storage has become increasingly important for achieving urban sustainability. This study analyzed the effects of urban expansion on terrestrial carbon storage in Xuzhou City, China during 2000–2025. The cellular automata (CA model was developed to simulate future urban expansion under three scenarios, namely, the business as usual (BAU, ecological protection (ECO, and planning strengthened (PLS scenarios. The Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST model was further applied to explore the consequences of urban expansion on carbon storage. The results show that urban expansion resulted in 6.099 Tg of carbon storage loss from 2000–2015. Moreover, significant differences in the effects of the urban expansion scenarios on carbon storage were identified in terms of both magnitude and spatial pattern from 2015–2025. Compared with the other scenarios, the PLS scenario could be considered as a good option that would allow future development to achieve the objectives of the lowest carbon storage losses. The findings improve the understanding of the effects of urban expansion on carbon storage and may be used to support urban planning and management.

  6. Studies of the contributions of nonpoint terrestrial sources to mineral water quality

    International Nuclear Information System (INIS)

    Huff, D.D.

    1977-05-01

    The contributions of nonpoint sources of water quality constituents represent a background loading rate that will not be reduced easily. Consequently, those contributions may have a dominant effect on aquatic ecosystems once point sources have been controlled. Modeling studies conducted at the Tennessee Valley Authority and Oak Ridge National Laboratory represent contrasting approaches that highlight some of the possibilities for predicting nonpoint source inputs to aquatic systems

  7. Volcanic settings and their reservoir potential: An outcrop analog study on the Miocene Tepoztlán Formation, Central Mexico

    Science.gov (United States)

    Lenhardt, Nils; Götz, Annette E.

    2011-07-01

    The reservoir potential of volcanic and associated sedimentary rocks is less documented in regard to groundwater resources, and oil and gas storage compared to siliciclastic and carbonate systems. Outcrop analog studies within a volcanic setting enable to identify spatio-temporal architectural elements and geometric features of different rock units and their petrophysical properties such as porosity and permeability, which are important information for reservoir characterization. Despite the wide distribution of volcanic rocks in Mexico, their reservoir potential has been little studied in the past. In the Valley of Mexico, situated 4000 m above the Neogene volcanic rocks, groundwater is a matter of major importance as more than 20 million people and 42% of the industrial capacity of the Mexican nation depend on it for most of their water supply. Here, we present porosity and permeability data of 108 rock samples representing five different lithofacies types of the Miocene Tepoztlán Formation. This 800 m thick formation mainly consists of pyroclastic rocks, mass flow and fluvial deposits and is part of the southern Transmexican Volcanic Belt, cropping out south of the Valley of Mexico and within the two states of Morelos and Mexico State. Porosities range from 1.4% to 56.7%; average porosity is 24.8%. Generally, permeabilities are low to median (0.2-933.3 mD) with an average permeability of 88.5 mD. The lavas are characterized by the highest porosity values followed by tuffs, conglomerates, sandstones and tuffaceous breccias. On the contrary, the highest permeabilities can be found in the conglomerates, followed by tuffs, tuffaceous breccias, sandstones and lavas. The knowledge of these petrophysical rock properties provides important information on the reservoir potential of volcanic settings to be integrated to 3D subsurface models.

  8. Ar-40/Ar-39 Studies of Martian Meteorite RBT 04262 and Terrestrial Standards

    Science.gov (United States)

    Park, J.; Herzog, G. F.; Turrin, B.; Lindsay, F. N.; Delaney, J. S.; Swisher, C. C., III; Nagao, K.; Nyquist, L. E.

    2014-01-01

    Park et al. recently presented an Ar-40/Ar-39 dating study of maskelynite separated from the Martian meteorite RBT 04262. Here we report an additional study of Ar-40/Ar-39 patterns for smaller samples, each consisting of only a few maskelynite grains. Considered as a material for Ar-40/Ar-39 dating, the shock-produced glass maskelynite has both an important strength (relatively high K concentration compared to other mineral phases) and some potentially problematic weaknesses. At Rutgers, we have been analyzing small grains consisting of a single phase to explore local effects that might be averaged and remain hidden in larger samples. Thus, to assess the homogeneity of the RBT maskelynite and for comparison with the results of, we analyzed six approx. 30 microgram samples of the same maskelynite separate they studied. Furthermore, because most Ar-40/Ar-39 are calculated relative to the age of a standard, we present new Ar-40/Ar-39 age data for six standards. Among the most widely used standards are sanidine from Fish Canyon (FCs) and various hornblendes (hb3gr, MMhb-1, NL- 25), which are taken as primary standards because their ages have been determined by independent, direct measurements of K and A-40.

  9. Study nonlinear dynamics of stratospheric ozone concentration at Pakistan Terrestrial region

    Science.gov (United States)

    Jan, Bulbul; Zai, Muhammad Ayub Khan Yousuf; Afradi, Faisal Khan; Aziz, Zohaib

    2018-03-01

    This study investigates the nonlinear dynamics of the stratospheric ozone layer at Pakistan atmospheric region. Ozone considered now the most important issue in the world because of its diverse effects on earth biosphere, including human health, ecosystem, marine life, agriculture yield and climate change. Therefore, this paper deals with total monthly time series data of stratospheric ozone over the Pakistan atmospheric region from 1970 to 2013. Two approaches, basic statistical analysis and Fractal dimension (D) have adapted to study the nature of nonlinear dynamics of stratospheric ozone level. Results obtained from this research have shown that the Hurst exponent values of both methods of fractal dimension revealed an anti-persistent behavior (negatively correlated), i.e. decreasing trend for all lags and Rescaled range analysis is more appropriate as compared to Detrended fluctuation analysis. For seasonal time series all month follows an anti-persistent behavior except in the month of November which shown persistence behavior i.e. time series is an independent and increasing trend. The normality test statistics also confirmed the nonlinear behavior of ozone and the rejection of hypothesis indicates the strong evidence of the complexity of data. This study will be useful to the researchers working in the same field in the future to verify the complex nature of stratospheric ozone.

  10. The impact of fire on terrestrial tardigrade biodiversity: a first case-study from Portugal

    Directory of Open Access Journals (Sweden)

    Filipe Vicente

    2013-05-01

    Full Text Available Currently, loss of habitat is the greatest threat to biodiversity, yet little is known about its effect on microscopic animal taxa, such as Tardigrada. One of the causes of habitat destruction is forest fire, both natural and anthropogenic. The latter is commonly used in agriculture to kill insect pests, as a soil preparation, or conservation to create habitat mosaics. In Portugal, 42% of fire frequency is anthropogenic. There is no consensus on the impact of fires on biodiversity, with studies pointing towards different conclusions. Different methods and target taxonomic study groups may partly explain this paradigm. This study is the first into possible effects of habitat destruction on tardigrade populations, in which we analysed the taxonomic and genetic variations of tardigrades from a fire affected location in a Portuguese natural park. Sampling was performed over a 10-year period, from 2000 to 2010. The location was affected by a small fire in 1998 and a big fire in 2003. A total of 11 species from nine separate genera was recorded, from which 19 cox1 haplotypes were identified. Our data suggest a negative effect of a forest fire on tardigrade populations. Taxonomic and genetic richness, as well as abundance show lower levels in the years after a fire, compared with the preceding years. Additionally, the population recovered visibly faster after the small fire than after the bigger one. This is consistent with larger fires destroying larger forest areas, leaving fewer animals at a farther distance available for re-colonisation. Most species found before the main fire are also found after it, indicating these tardigrades have a high recolonisation capability. However, only three of all recorded haplotypes were found both pre and post the main fire, which indicates genetic diversity loss as a direct consequence of fire. Therefore, we conclude that habitat destruction by means of forest fire has a detrimental effect on tardigrade

  11. Experimental study of electronic electrostatic waves detected in the terrestrial magnetosphere by the satellite GEOS 2

    International Nuclear Information System (INIS)

    Canu, P.

    1982-09-01

    After reviewing the general characteristics of electrostator waves a brief resume is given of the observations made up to the present moment. The GEOS satellite and the ''wave'' experiment are described, as well as the method and results of the statistical study of the strong electrostatic wave observed. Creating mechanisms of diffuse auroras are discussed. In a later chapter a new method of using the relaxation probe is presented as well as the results it gives on the mode of propagation of waves in the neighbourhood of the FUH frequency [fr

  12. USAF Advanced Terrestrial Energy Study. Volume 4. Analysis, Data, and Bibliography.

    Science.gov (United States)

    1983-04-01

    bYftUb IUM sac E1PT 𔃾U CUP- Ps4 #t~f*-- PAGE NO 3kr-3 CONP TIt PUWEM bU$JkCL%* bYNPI~bIUl4 COMP PLAeLi ATLANTIL Lilt. NJ* USA COMP DAIL 12 JUt. IV76 PubLe...ATTRACTIVE WHEN COMPARED WITH BATTERIES AND DIESEL ENGINES. IT IS THE ENELRGY-WEIGHT RATIO WHICH MOTIVATE & FUEL-ICELL APPLICATION. EXAMINATION OP THE...Allocated Study, Operating Plant Reference Goal or or Experimental Number Target Results or Comments B. 7 >60% 65-70% Golf cart Motive power size B. 23 60

  13. Isotopic studies of rare gases in terrestrial samples and natural nucleosynthesis

    International Nuclear Information System (INIS)

    1991-05-01

    This project is concerned with research in rare gas mass spectrometry. Using a two-pronged attack, we study fluids using a system (RARGA) designed for fluid analysis in bulk which is sometimes deployed in the field and a laser microprobe mass spectrometer for fluid inclusion studies. In 1991 the RARGA project continued monitoring helium isotope variations associated with renewed seismic activity in Long Valley Caldera and expanded our geothermal data base to include Lassen National Park. An important objective, continuing in 1992, is to understand better the reasons for somewhat elevated 3 He/ 4 He ratios in regions where there is no contemporary volcanism which could produce the effect by addition of mantle helium. To this end, 1991 saw continued efforts to understand variations in composition between fluids and associated reservoir rocks and extended the data base to include fluids from the Gulf of Mexico. Our DOE work in calibrating a sensitive laser microprobe mass spectrometer for noble gases in fluid inclusions continues with successful returns particularly in calibrating neutron irradiated samples for tracing halogen ratios. In connection with observations of neutron-produced noble gas nuclides in granites, we have begun comparing measurements with calculations for both thermal and epithermal neutrons. We submitted a third paper on noble gases in diamonds, concentrating on observed effects of 4 He, 3 He, and fission xenon implantation from nuclear processes in adjacent material in the matrix rock. 16 refs., 1 tab

  14. Producing and Recognizing Analogical Relations

    Science.gov (United States)

    Lipkens, Regina; Hayes, Steven C

    2009-01-01

    Analogical reasoning is an important component of intelligent behavior, and a key test of any approach to human language and cognition. Only a limited amount of empirical work has been conducted from a behavior analytic point of view, most of that within Relational Frame Theory (RFT), which views analogy as a matter of deriving relations among relations. The present series of four studies expands previous work by exploring the applicability of this model of analogy to topography-based rather than merely selection-based responses and by extending the work into additional relations, including nonsymmetrical ones. In each of the four studies participants pretrained in contextual control over nonarbitrary stimulus relations of sameness and opposition, or of sameness, smaller than, and larger than, learned arbitrary stimulus relations in the presence of these relational cues and derived analogies involving directly trained relations and derived relations of mutual and combinatorial entailment, measured using a variety of productive and selection-based measures. In Experiment 1 participants successfully recognized analogies among stimulus networks containing same and opposite relations; in Experiment 2 analogy was successfully used to extend derived relations to pairs of novel stimuli; in Experiment 3 the procedure used in Experiment 1 was extended to nonsymmetrical comparative relations; in Experiment 4 the procedure used in Experiment 2 was extended to nonsymmetrical comparative relations. Although not every participant showed the effects predicted, overall the procedures occasioned relational responses consistent with an RFT account that have not yet been demonstrated in a behavior-analytic laboratory setting, including productive responding on the basis of analogies. PMID:19230515

  15. D-seco-Vitamin D analogs having reversed configurations at C-13 and C-14: Synthesis, docking studies and biological evaluation.

    Science.gov (United States)

    Szybinski, Marcin; Sokolowska, Katarzyna; Sicinski, Rafal R; Plum, Lori A; DeLuca, Hector F

    2017-10-01

    Prompted by results of molecular modeling performed on the seco-d-ring-vitamins D, we turned our attention to such analogs, having reversed configurations at C-13 and C-14, as the next goals of our studies on the structure-activity relationship for vitamin D compounds. First, we developed an efficient total synthesis of the "upper" C/seco-d-ring fragment with a 7-carbon side chain. Then, we coupled it with A-ring fragments using Sonogashira or Wittig-Horner protocol, providing the targeted D-seco analogs of 1α,25-dihydroxyvitamin D 3 and 1α,25-dihydroxy-19-norvitamin D 3 possessing a vinyl substituent at C-14 and a double bond between C-17 and C-20. The affinities of the synthesized vitamin D analogs to the full-length recombinant rat VDR were examined, as well as their differentiating and transcriptional activities. In these in vitro tests, they were significantly less active compared to 1α,25-(OH) 2 D 3 . Moreover, it was established that the analogs tested in vivo in rats showed no calcemic potency. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Natural-analog studies for partial validation of conceptual models of radionuclide retardation at the Waste Isolation Pilot Plant (WIPP)

    International Nuclear Information System (INIS)

    Ward, D.B.; Brookins, D.G.

    1990-01-01

    Transport by groundwater within the Culebra Dolomite, an aquifer above the Waste Isolation Pilot Plant (WIPP), is the most probable mechanism for long-term release of radionuclides to the accessible environment. Radionuclides could be retarded by sorption if the groundwater is exposed to sufficient amounts of fracture-lining clays. In this natural-analog study, distributions of U and trace metals have been examined to constrain the strength of clay/solute interactions within the Culebra. Uranium solid/liquid distribution ratios, calculated from U concentrations of groundwaters and consanguineous fracture-filling clays, range from ∼80 to 800 m ell/g and imply retardation factors of 60 to 500 using a fracture-flow model. Retardation factors inferred from uranium-series disequilibria and 14 C ages in Culebra groundwaters alone are much lower (∼10), implying that clays may contain a significant unreactive component of U. Such a possibility is corroborated by Rb/Sr ages; these imply long-term stability of the clays,with resetting occurring more than 250 Ma ago. Factor analysis and mass-balance calculations suggest, however, that Mg-rich clays are dissolving in Pleistocene-age groundwaters and/or are converting to Na-rich smectites, and that B and Li are taken up from the water by the clays. Apparently, the solution chemistry reflects gradual equilibration of clays with groundwater, but thus far the bulk of the clays remain structurally intact. Measurements of the distribution of U in the Culebra will be more meaningful if the inert and exchangeable components of the U content of the clays can be quantified. 26 refs., 3 figs., 2 tabs

  17. Studies of activation products in the terrestrial environment of three swedish nuclear power stations

    International Nuclear Information System (INIS)

    Ingemansson, T.; Erlandsson, B.; Mattsson, S.

    1982-01-01

    Samples of sewage sludge, lichen (Cladonia alpestris), soil and ground level air have been analysed for activation products released to the atmosphere from the three Swedish nuclear power stations at Simpevarp near Oskarshamn, Ringhals and Barsebaeck. The activity concentration of the activation products in the sludge can be arranged in the following sequence: 60 Co > 65 Zn > 58 Co 54 Mn. There is agreement between the time variation of the activity concentration in the sludge and the reported releases to the air from the power stations. The measured activity ratio 58 Co/ 60 Co in sludge does not significantly differ from that reported in the releases to the air. The activity concentration in sludge sedimented from incoming waste water has been used to get better time resolution than using only digested sludge from the final step of the plant. These studies have shown that the activity concentration of 60 Co increases substantially with the first rain run-off that reaches the sewage plant and then falls off rapidly. Measurements on samples of lichen and underlying soil show that the radioactive cobalt isotopes ( 58 Co and 60 Co) have a short mean residence time in the lichen carpet compared to most fission products present in global fall-out. (author)

  18. Studies of the terrestrial O2 and carbon cycles in sand dune gases and in biosphere 2

    Energy Technology Data Exchange (ETDEWEB)

    Severinghaus, Jeffrey Peck [Columbia Univ., New York, NY (United States)

    1995-01-01

    Molecular oxygen in the atmosphere is coupled tightly to the terrestrial carbon cycle by the processes of photosynthesis, respiration, and burning. This dissertation examines different aspects of this coupling in four chapters. Chapter 1 explores the feasibility of using air from sand dunes to reconstruct atmospheric O2 composition centuries ago. Such a record would reveal changes in the mass of the terrestrial biosphere, after correction for known fossil fuel combustion, and constrain the fate of anthropogenic CO2.

  19. Experimental studies on the uptake of technetium-99 to terrestrial crops

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Joanne; Ewers, Leon [Centre for Radiation, Chemical and Environmental Hazards, Public Health England (United Kingdom)

    2014-07-01

    Technetium-99 has been dispersed in the environment from many sources such as nuclear weapons testing, releases from medical or industrial processes, nuclear power plants and nuclear fuel processing facilities. The pertechnetate ion, {sup 99}TcO{sub 4}{sup -} is the form produced during the nuclear fuel cycle and the most likely to be released into the environment. A recent review published by Public Health England (formerly the Health Protection Agency) found that the availability for the root uptake of technetium into crops depends on whether the technetium is in a chemically non-reduced more plant available form, such as TcO{sub 4}{sup -} or a chemically reduced less plant available form, such as TcO{sub 2}. Based on the review, generic soil to crop transfer factor (TF) values for use in non-site specific UK based radiological assessments were proposed, with the TF value for the reduced form of technetium in crops around a factor of 10 lower than that for the non-reduced form. The implications of the use of different TF values on the activity concentrations in crops and animal products predicted by PHE's food chain model, FARMLAND, for both routine and accidental release situations were explored. Recommendations on the best choice of TF values for use in the model have been given for a range of contamination scenarios. A small scale experimental study has been carried out to provide further evidence that the generic assumption made on the difference between soil-crop TF values for non-reduced and reduced forms of technetium is valid. The study was also designed to establish likely time periods over which the chemical reduction of technetium takes place and to provide additional soil-crop TF values for use in UK based radiological assessments. Soil to crop TFs for crops harvested from loam and peat soils up to 4 months after contamination are about a factor of 10 higher than those seen in soil contaminated more than a year previously, indicating that the

  20. Lichen biomarkers upon heating: a Raman spectroscopic study with implications for extra-terrestrial exploration

    Science.gov (United States)

    Miralles, I.; Capel Ferrón, C.; Hernández, V.; López-Navarrete, J. T.; Jorge-Villar, S. E.

    2017-01-01

    Lithopanspermia Theory has suggested that life was transferred among planets by meteorites and other rocky bodies. If the planet had an atmosphere, this transfer of life had to survive drastic temperature changes in a very short time in its entry or exit. Only organisms able to endure such a temperature range could colonize a planet from outer space. Many experiments are being carried out by NASA and European Space Agency to understand which organisms were able to survive and how. Among the suite of instruments designed for extraplanetary exploration, particularly for Mars surface exploration, a Raman spectrometer was selected with the main objective of looking for life signals. Among all attributes, Raman spectroscopy is able to identify organic and inorganic compounds, either pure or in admixture, without requiring sample manipulation. In this study, we used Raman spectroscopy to examine the lichen Squamarina lentigera biomarkers. We analyse spectral signature changes after sample heating under different experimental situations, such as (a) laser, (b) analysis accumulations over the same spot and (c) environmental temperature increase. Our goal is to evaluate the capability of Raman spectroscopy to identify unambiguously life markers even if heating has induced spectral changes, reflecting biomolecular transformations. Usnic acid, chlorophyll, carotene and calcium oxalates were identified by the Raman spectra. From our experiments, we have seen that usnic acid, carotene and calcium oxalates (the last two have been suggested to be good biomarkers) respond in a different way to environmental heating. Our main conclusion is that despite their abundance in nature or their inorganic composition the resistance to heat makes some molecules more suitable than others as biomarkers.

  1. Analog circuit design

    CERN Document Server

    Dobkin, Bob

    2012-01-01

    Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

  2. Use of geochemical and isotope tracers to assess groundwater dependency of a terrestrial ecosystem: case study from southern Poland

    Science.gov (United States)

    Zurek, Anna J.; Witczak, Stanislaw; Kania, Jaroslaw; Rozanski, Kazimierz; Dulinski, Marek; Wachniew, Przemyslaw

    2015-04-01

    The presented study was aimed at better understanding of the functioning of groundwater dependent terrestrial ecosystem (GDTE) located in the south of Poland. The studied GDTE consists of a valuable forest stand (Niepolomice Forest) and associated wetland (Wielkie Bloto fen). It relies not only on shallow, unconfined aquifer but indirectly also on groundwater originating from the deeper confined aquifer, underlying the Quaternary cover and separated from it by an aquitard of variable thickness. The main objective of the study was to evaluate the contribution of groundwater to the water balance of the studied GDTE and thereby assess the potential risk to this system associated with intense exploitation of the deeper aquifer. The Wielkie Błoto fen area and the adjacent parts of Niepolomice Forest are drained by the Dluga Woda stream with 8.2 km2 of gauged catchment area. Hydrometric measurements, carried out on the Dluga Woda stream over two-year period (August 2011 - August 2013) were supplemented by chemical and isotope analyses of stream water, monitored on monthly basis. Physico-chemical parameters of the stream water (SEC, pH, Na content, Na/Cl molar ratio) and isotope tracers (deuterium, oxygen-18 and tritium) were used to quantify the expected contribution of groundwater seepage from the deeper aquifer to the water balance of the Dluga Woda catchment. The mean transit time of water through the catchment, derived from temporal variations of δ18O and tritium content in the Dluga Woda stream, was in the order of three months. This fast component of the total discharge of Dluga Woda stream is associated surface runoff and groundwater flow paths through the Quaternary cover. The slow component devoid of tritium and probably originated from the deeper Neogene aquifer is equal to approximately 30% of the total discharge. The relationships between the physico-chemical parameters of the stream water and the flow rate of Dluga Woda clearly indicate that the monitored

  3. Chemical and Biological Substances Decontamination Study for Mars Missions and Terrestrial Applications

    Science.gov (United States)

    Pottage, Thomas; Walker, James; Bennett, Allan; Vrublevskis, John; Hovland, Scott

    This study, funded by the European Space Agency (ESA) and undertaken by the Health Protec-tion Agency, UK supported by Systems Engineering and Assessment Ltd., was devised to select suitable current decontamination technologies for development for future manned missions to the Moon and Mars. There is a requirement to decontaminate the habitat module due to the concerns about astronaut ill health, microbial deterioration of materials and potential forward contamination in the case of Mars. In the case of the MIR space station, biodeterioration of components and materials occurred, and dangerous levels of airborne microorganisms were detected during air sampling procedures which lead to the introduction of microbial exposure limits (as MORD SSP 50260) to ensure the health of the crew. COSPAR planetary protection guidelines highlight the need to reduce any potential forward or backwards contamination issues that may occur through the use of Extra Vehicular Activity (EVA) suits whilst on Mars. Decontamination of the suit exterior must be completed before any EVA activity on Mars, whilst a further decontamination cycle must be completed after entry to the airlock following EVA. Technologies and techniques have also been investigated for the microbial reduction of the interior surfaces of the EVA suit to stop biodeterioration of the materials and protect the user from pathogenic microbe accumulation. The first work package reviewed the systems description and requirements as detailed in the statement of work. The requirements were broken down into 12 further requirement sections, where they were updated and expanded, resulted in Technical Note (TN) 1 which was then used as the base document for WP2 and WP3. WP2 investigated the current technologies available for the decontamination of the habitat module interior on missions of up to 6 months and missions that have durations of greater than 6 months. A comprehensive review was carried out for the different methods that

  4. Analog synthetic biology.

    Science.gov (United States)

    Sarpeshkar, R

    2014-03-28

    We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecular count and part-count resources needed to compute at a given level of precision. We conclude that analog computation is significantly more efficient in its use of resources than deterministic digital computation even at relatively high levels of precision in the cell. Based on this analysis, we conclude that synthetic biology must use analog, collective analog, probabilistic and hybrid analog-digital computational approaches; otherwise, even relatively simple synthetic computations in cells such as addition will exceed energy and molecular-count budgets. We present schematics for efficiently representing analog DNA-protein computation in cells. Analog electronic flow in subthreshold transistors and analog molecular flux in chemical reactions obey Boltzmann exponential laws of thermodynamics and are described by astoundingly similar logarithmic electrochemical potentials. Therefore, cytomorphic circuits can help to map circuit designs between electronic and biochemical domains. We review recent work that uses positive-feedback linearization circuits to architect wide-dynamic-range logarithmic analog computation in Escherichia coli using three transcription factors, nearly two orders of magnitude more efficient in parts than prior digital implementations.

  5. A case study on the historical peninsula of Istanbul based on three-dimensional modeling by using photogrammetry and terrestrial laser scanning.

    Science.gov (United States)

    Ergun, Bahadir; Sahin, Cumhur; Baz, Ibrahim; Ustuntas, Taner

    2010-06-01

    Terrestrial laser scanning is a popular methodology that is used frequently in the process of documenting historical buildings and cultural heritage. The historical peninsula region sprawls over an area of approximately 1,500 ha and is one of the main aggregate areas of the historical buildings in Istanbul. In this study, terrestrial laser scanning and close range photogrammetry techniques are integrated into each other to create a 3D city model of this part of Istanbul, including some of the buildings that represent the most brilliant areas of Byzantine and Ottoman Empires. Several terrestrial laser scanners with their different specifications were used to solve various geometric scanning problems for distinct areas of the subject city. Photogrammetric method was used for the documentation of the façades of these historical buildings for architectural purposes. This study differentiates itself from the similar ones by its application process that focuses on the geometry, the building texture, and density of the study area. Nowadays, the largest-scale studies among 3D modeling studies, in terms of the methodology of measurement, are urban modeling studies. Because of this large scale, the application of 3D urban modeling studies is executed in a gradual way. In this study, a modeling method based on the façades of the streets was used. In addition, the complimentary elements for the process of modeling were combined in several ways. A street model was presented as a sample, as being the subject of the applied study. In our application of 3D modeling, the modeling based on close range photogrammetry and the data of combined calibration with the data of terrestrial laser scanner were used in a compatible way. The final work was formed with the pedestal data for 3D visualization.

  6. Analogy-Enhanced Instruction: Effects on Reasoning Skills in Science

    Science.gov (United States)

    Remigio, Krisette B.; Yangco, Rosanelia T.; Espinosa, Allen A.

    2014-01-01

    The study examined the reasoning skills of first year high school students after learning general science concepts through analogies. Two intact heterogeneous sections were randomly assigned to Analogy-Enhanced Instruction (AEI) group and Non Analogy-Enhanced (NAEI) group. Various analogies were incorporated in the lessons of the AEI group for…

  7. An overview of structure-activity relationship studies of curcumin analogs as antioxidant and anti-inflammatory agents.

    Science.gov (United States)

    Arshad, Laiba; Haque, Md Areeful; Abbas Bukhari, Syed Nasir; Jantan, Ibrahim

    2017-04-01

    Curcumin, extracted mainly from Curcuma longa rhizomes, has been reported to possess potent anti-inflammatory and anti-oxidant activities. Although safe at higher doses and exhibiting multiple biological activities, curcumin still has the problem of poor bioavailability which has been an attractive area of research over the last few years. A number of efforts have been made by modifying structural features of curcumin. This review highlights the structurally modified and more stable newly synthesized curcumin analogs that have been screened against antioxidant and anti-inflammatory activities. Also the structure-activity relationship to gain insight into future guidelines for scheming new compounds has been discussed, and further these analogs being more stable may serve as promising agents for use in different pathological conditions.

  8. Characterizing Terrestrial Exoplanets

    Science.gov (United States)

    Meadows, V. S.; Lustig-Yaeger, J.; Lincowski, A.; Arney, G. N.; Robinson, T. D.; Schwieterman, E. W.; Deming, L. D.; Tovar, G.

    2017-11-01

    We will provide an overview of the measurements, techniques, and upcoming missions required to characterize terrestrial planet environments and evolution, and search for signs of habitability and life.

  9. Cooling tower drift studies at the Paducah, Kentucky Gaseous Diffusion Plant. [Transport of drift-derived chromium in terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, F.G.; Hanna, S.R.; Parr, P.D.

    1979-01-01

    The transfer and fate of chromium from cooling tower drift to terrestrial ecosystems were quantified at the Department of Energy's uranium enrichment facility at Paducah, Kentucky. Chromium concentrations in plant materials (fescue grass) decreased with increasing distance from the cooing tower, ranging from 251 +- 19 ppM at 15 meters to 0.52 +- 0.07 ppM at 1500 meters. The site of drift contamination, size characteristics, and elemental content of drift particles were determined using a scanning electron microscope with energy dispersive x-ray analysis capabilities. Results indicate that elemental content in drift water (mineral residue) may not be equivalent to the content in the recirculating cooling water of the tower. This hypothesis is contrary to basic assumptions in calculating drift emissions. A laboratory study simulating throughfall from 1 to 6 inches of rain suggested that there are more exchange sites associated with litter than live foliage. Leachate from each one inch throughfall simulant removed 3% of the drift mass from litter compared to 7 to 9% from live foliage. Results suggest that differences in retention are related to chemical properties of the drift rather than physical lodging of the particle residue. To determine the potential for movement of drift-derived chromium to surface streams, soil--water samplers (wells) were placed along a distance gradient to Little Bayou Creek. Samples from two depths following rainstorms revealed the absence of vertical or horizontal movement with maximum concentrations of 0.13 ppb at 50 meters from the tower. Preliminary model estimates of drift deposition are compared to depositionmeasurements. Isopleths of the predicted deposition are useful to identify areas of maximum drift transport in the environs of the gaseous diffusion plant.

  10. Are winter-active species vulnerable to climate warming? A case study with the wintergreen terrestrial orchid, Tipularia discolor.

    Science.gov (United States)

    Marchin, Renée M; Dunn, Robert R; Hoffmann, William A

    2014-12-01

    In the eastern United States, winter temperature has been increasing nearly twice as fast as summer temperature, but studies of warming effects on plants have focused on species that are photosynthetically active in summer. The terrestrial orchid Tipularia discolor is leafless in summer and acquires C primarily in winter. The optimum temperature for photosynthesis in T. discolor is higher than the maximum temperature throughout most of its growing season, and therefore growth can be expected to increase with warming. Contrary to this hypothesis, experimental warming negatively affected reproductive fitness (number of flowering stalks, flowers, fruits) and growth (change in leaf area from 2010 to 2012) in T. discolor. Temperature in June-July was critical for flowering, and mean July temperature greater than 29 °C (i.e., 2.5 °C above ambient) eliminated reproduction. Warming of 1.2 °C delayed flowering by an average of 10 days and fruiting by an average of 5 days. Warming of 4.4 °C reduced relative growth rates by about 60%, which may have been partially caused by the direct effects of temperature on photosynthesis and respiration. Warming indirectly increased vapor pressure deficit (VPD) by 0.2-0.5 kPa, and leaf-to-air VPD over 1.3 kPa restricted stomatal conductance of T. discolor to 10-40% of maximum conductance. These results highlight the need to account for changes in VPD when estimating temperature responses of plant species under future warming scenarios. Increasing temperature in the future will likely be an important limiting factor to the distribution of T. discolor, especially along the southern edge of its range.

  11. Challenges in Using Analogies

    Science.gov (United States)

    Lin, Shih-Yin; Singh, Chandralekha

    2011-01-01

    Learning physics requires understanding the applicability of fundamental principles in a variety of contexts that share deep features. One way to help students learn physics is via analogical reasoning. Students can be taught to make an analogy between situations that are more familiar or easier to understand and another situation where the same…

  12. Hydraulic Capacitor Analogy

    Science.gov (United States)

    Baser, Mustafa

    2007-01-01

    Students have difficulties in physics because of the abstract nature of concepts and principles. One of the effective methods for overcoming students' difficulties is the use of analogies to visualize abstract concepts to promote conceptual understanding. According to Iding, analogies are consistent with the tenets of constructivist learning…

  13. Monitoring gully change: A comparison of airborne and terrestrial laser scanning using a case study from Aratula, Queensland

    Science.gov (United States)

    Goodwin, Nicholas R.; Armston, John D.; Muir, Jasmine; Stiller, Issac

    2017-04-01

    Airborne laser scanning (ALS) and terrestrial laser scanning (TLS) technologies capture spatially detailed estimates of surface topography and when collected multi-temporally can be used to assess geomorphic change. The sensitivity and repeatability of ALS measurements to characterise geomorphic change in topographically complex environments such as gullies; however, remains an area lacking quantitative research. In this study, we captured coincident ALS and TLS datasets to assess their ability and synergies to detect geomorphic change for a gully located in Aratula, southeast Queensland, Australia. We initially used the higher spatial density and ranging accuracy of TLS to provide an assessment of the Digital Elevation Models (DEM) derived from ALS within a gully environment. Results indicated mean residual errors of 0.13 and 0.09 m along with standard deviation (SD) of residual errors of 0.20 and 0.16 m using pixel sizes of 0.5 and 1.0 m, respectively. The positive mean residual errors confirm that TLS data consistently detected deeper sections of the gully than ALS. We also compared the repeatability of ALS and TLS for characterising gully morphology. This indicated that the sensitivity to detect change using ALS is substantially lower than TLS, as expected, and that the ALS survey characteristics influence the ability to detect change. Notably, we found that using one ALS transect (mean density of 5 points / m2) as opposed to three transects increased the SD of residual error by approximately 30%. The supplied classification of ALS ground points was also demonstrated to misclassify gully features as non-ground, with minimum elevation filtering found to provide a more accurate DEM of the gully. The number and placement of terrestrial laser scans were also found to influence the derived DEMs. Furthermore, we applied change detection using two ALS data captures over a four year period and four TLS field surveys over an eight month period. This demonstrated that

  14. Natural analogs for Yucca Mountain

    International Nuclear Information System (INIS)

    Murphy, W.M.

    1995-01-01

    High-level radioactive waste in the US, spent fuels from commercial reactors and nuclear materials generated by defense activities, will remain potentially hazardous for thousands of years. Demonstrable long-term stability of certain geologic and geochemical systems motivates and sustains the concept that high-level waste can be safely isolated in geologic repositories for requisite periods of time. Each geologic repository is unique in its properties and performance with reguard to isolation of nuclear wastes. Studies of processes analogous to waste-form alteration and radioelement transport in environments analogous to Yucca Mountain are being conducted at two sites, described in this article to illustrate uses of natural analog data: the Nopal I uranium deposit in the Sierra Pena Blanca, Mexico, and the Akrotiri archaeological site on the island of Santorini, Greece

  15. Antibacterial activity of Tribulus terrestris and its synergistic effect with Capsella bursa-pastoris and Glycyrrhiza glabra against oral pathogens: an in-vitro study

    Science.gov (United States)

    Soleimanpour, Saman; Sedighinia, Fereshteh Sadat; Safipour Afshar, Akbar; Zarif, Reza; Ghazvini, Kiarash

    2015-01-01

    Objective: In this study, antimicrobial activities of an ethanol extract of Tribulus terrestris aloneand in combination with Capsella bursa-pastoris and Glycyrrhiza glabra were examined in vitro against six pathogens namely Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, Enterococcus faecalis Staphylococcus aureus, and Escherichia coli. Materials and methods: Antibacterial activities of the extracts were examined using disc and well diffusion methods and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ethanol extracts were determined against these microorganisms using agar and broth dilution methods. Chlorhexidine was used as positive control. Results: Tribulus terrestris extract exhibited good antibacterial activity against all bacteria. Antibacterial activity of mixed extract was evaluated and exhibited that mixed extract was more effective against all bacteria than any of the cases alone which indicates the synergistic effect between these three extracts (p˂0.05). No strain showed resistance against these extracts. In agar dilution, Tribulus terrestris exhibited MIC values ranging from 35.0 to 20.0 mg/ml and mixed extract showed MIC values ranging from 12.5 to 5.0 mg/ml. The results of broth dilution method were consistent with the findings of the agar dilution method. Conclusion: This in-vitro study was a preliminary evaluation of antibacterial activity of the plants. It provided scientific evidence to support uses of T. terrestris and its mixture with C. bursa-pastoris and G. glabra for the treatment of oral infections. In-vivo studies are also required to better evaluate the effect of these extracts. PMID:26101754

  16. Antibacterial activity of Tribulus terrestris and its synergistic effect with Capsella bursa-pastoris and Glycyrrhiza glabra against oral pathogens: an in-vitro study

    Directory of Open Access Journals (Sweden)

    Saman Soleimanpour

    2015-04-01

    Full Text Available Objective: In this study, antimicrobial activities of an ethanol extract of Tribulus terrestris aloneand in combination with Capsella bursa-pastoris and Glycyrrhiza glabra were examined in vitro against six pathogens namely Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, Enterococcus faecalis Staphylococcus aureus, and Escherichia coli. Materials and methods: Antibacterial activities of the extracts were examined using disc and well diffusion methods and the minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC of ethanol extracts were determined against these microorganisms using agar and broth dilution methods. Chlorhexidine was used as positive control. Results: Tribulus terrestris extract exhibited good antibacterial activity against all bacteria. Antibacterial activity of mixed extract was evaluated and exhibited that mixed extract was more effective against all bacteria than any of the cases alone which indicates the synergistic effect between these three extracts (p˂0.05. No strain showed resistance against these extracts. In agar dilution, Tribulus terrestris exhibited MIC values ranging from 35.0 to 20.0 mg/ml and mixed extract showed MIC values ranging from 12.5 to 5.0 mg/ml. The results of broth dilution method were consistent with the findings of the agar dilution method. Conclusion: This in-vitro study was a preliminary evaluation of antibacterial activity of the plants. It provided scientific evidence to support uses of T. terrestris and its mixture with C. bursa-pastoris and G. glabra for the treatment of oral infections. In-vivo studies are also required to better evaluate the effect of these extracts.

  17. Investigation of 3′-debenzoyl-3′-(3-([124I]-iodobenzoyl))paclitaxel analog as a radio-tracer to study multidrug resistance in vivo

    International Nuclear Information System (INIS)

    Sajjad, M.; Riaz, U.; Yao, R.; Bernacki, R.J.; Abouzied, M.; Erb, D.A.; Chaudhary, N.D.; Veith, J.M.; Georg, G.I.; Nabi, H.A.

    2012-01-01

    A study was carried out to identify a suitable radioactive paclitaxel analog and to use it to investigate tumor multidrug resistance in vivo. 3′-Debenzoyl-3′-(3-([ 124 I]-iodobenzoyl))paclitaxel was prepared by aromatic iodination of 3′-debenzoyl-3′-(3-trimethylstannylbenzoyl)paclitaxel. Uptake of the labeled paclitaxel analog in nude mice bearing tumor with the paclitaxel sensitive cancer cell lines MCF7 and MDA-435/LCC6(WT), and multidrug resistant cell lines NCI/ADR-RES and MDA-435/LCC6(MDR), was studied. There was no difference in drug level between the sensitive and resistant MDA-435/LCC6 tumors at 6 h post-injection. However, at 6 h, there was a significant increase in drug level for the MCF7 tumor as compared with the NCI/ADR-RES tumor, presumably due to increased drug retention. At 24 h, drug uptake/retention was significantly higher in both sensitive tumor cell lines as compared to their drug resistant counterparts. Pretreatment of mice with MDR transport modulators, Cyclosporine or tRA 96029, did not increase the level of labeled paclitaxel analog in the drug resistant MDA-435/LCC6(MDR) tumor. On the other hand, at 24 h Cyclosporine apparently increased analog level in the drug sensitive MDA-435/LCC6(WT) tumor, aiding drug imaging studies. - Highlights: ► 3′-Debenzoyl-3′-(3-iodobenzoyl)paclitaxel cytotoxicity was comparable to paclitaxel. ► 3′-Debenzoyl-3′-(3-([ 124 I]-iodobenzoyl)paclitaxel was synthesized. ► Uptake of the drug was higher in sensitive tumor compared to the resistant tumor. ► The Pgp-modulators had a positive effect on drug-sensitive tumor. ► The sensitive tumor was visible in images obtained using micoPET.

  18. V. Terrestrial vertebrates

    Science.gov (United States)

    Dean Pearson; Deborah Finch

    2011-01-01

    Within the Interior West, terrestrial vertebrates do not represent a large number of invasive species relative to invasive weeds, aquatic vertebrates, and invertebrates. However, several invasive terrestrial vertebrate species do cause substantial economic and ecological damage in the U.S. and in this region (Pimental 2000, 2007; Bergman and others 2002; Finch and...

  19. Meat analog: a review.

    Science.gov (United States)

    Malav, O P; Talukder, S; Gokulakrishnan, P; Chand, S

    2015-01-01

    The health-conscious consumers are in search of nutritious and convenient food item which can be best suited in their busy life. The vegetarianism is the key for the search of such food which resembles the meat in respect of nutrition and sensory characters, but not of animal origin and contains vegetable or its modified form, this is the point when meat analog evolved out and gets shape. The consumers gets full satisfaction by consumption of meat analog due to its typical meaty texture, appearance and the flavor which are being imparted during the skilled production of meat analog. The supplement of protein in vegetarian diet through meat alike food can be fulfilled by incorporating protein-rich vegetative food grade materials in meat analog and by adopting proper technological process which can promote the proper fabrication of meat analog with acceptable meat like texture, appearance, flavor, etc. The easily available vegetables, cereals, and pulses in India have great advantages and prospects to be used in food products and it can improve the nutritional and functional characters of the food items. The various form and functional characters of food items are available world over and attracts the meat technologists and the food processors to bring some innovativeness in meat analog and its presentation and marketability so that the acceptability of meat analog can be overgrown by the consumers.

  20. Comparative analysis of components incorporated in conservation priority assessments: a case study based on South African species of terrestrial mammals

    CSIR Research Space (South Africa)

    Keith, M

    2007-04-01

    Full Text Available priority assessments of South African terrestrial mammals 99 Estimates of conservation value a) Relative Endemism (RE) – (modified from Freitag & van Jaarsveld (1997)). The extent of occurrence, obtained from various sources (Halte- north & Diller 1980... of threat a) Relative Body Mass (RBM) – Based on average body weights (in grams) for each taxon obtained from Dorst & Dandelot (1972), Haltenorth & Diller (1980), Skinner & Smithers (1990), and Skinner & Chimimba (2005) and was computed as: RBM = log...

  1. Isotopic tracers for net primary productivity for a terrestrial ecosystem: a case study of the Volta River basin

    International Nuclear Information System (INIS)

    Hayford, E.K.; Odamtten, G.T.; Enu-Kwesi, L.

    2006-01-01

    The coupling effect of vapour release and CO2 uptake during photosynthesis plays an important role in the carbon and hydrologic cycles. The water use efficiency (WUE) for transpiration was used in calculating the net primary productivity (NPP) for terrestrial ecosystem. Three parameters were used in calculating the water and carbon balance of the River Volta watershed. These are 1) stable isotopes of hydrogen and oxygen, 2) long-term data on precipitation and evapotranspiration, and 3) stoichiometric relations of water and carbon. Results indicate that soils in the watershed annually respire 0.199 Pg C, and that the NPP is +0.029 Pg C yr-1. This implies an annual change in CO2 to the atmosphere within the watershed. Annually, River Volta watershed receives about 380 km3 of rainfall; approximately 50 per cent of which is returned to the atmosphere through plant transpiration. Associated with annual transpiration flux is a carbon flux of 0.170 x 1015 g C yr-1 or 428 g C m-2 yr-1 from the terrestrial ecosystem. Modeled estimates of heterotrophic soil respiration exceeds slightly the estimated NPP values, implying that carbon flux to and from the Volta river watershed is close to being in balance. In other words, the watershed releases annually more carbon dioxide to the atmosphere than it takes. Apart from the terrestrial carbon flux, the balance of photosynthesis and respiration in the Volta lake was also examined. The lake was found to release carbon dioxide to the atmosphere although the magnitude of the flux is smaller than that of the terrestrial ecosystem. (au)

  2. Estimation Terrestrial Net Primary Productivity Based on CASA Model: a Case Study in Minnan Urban Agglomeration, China

    International Nuclear Information System (INIS)

    Hua, L Z; Liu, H; Zhang, X L; Zheng, Y; Man, W; Yin, K

    2014-01-01

    Net Primary Productivity (NPP) is a key component of the terrestrial carbon cycle. The research of net primary productivity will help in understanding the amount of carbon fixed by terrestrial vegetation and its influencing factors. Model simulation is considered as a cost-effective and time-efficient method for the estimation of regional and global NPP. In the paper, a terrestrial biosphere model, CASA (Carnegie Ames Stanford Approach), was applied to estimate monthly NPP in Minnan urban agglomeration (i.e. Xiamen, Zhangzhou and Quanzhou cities) of Fujian province, China, in 2009 and 2010, by incorporating satellite observation of SPOT Vegetation NDVI data together with other climatic parameters and landuse map. The model estimates average annual terrestrial NPP of Minnan area as 16.3 million Mg C. NPP decreased from southwest to the northeast. The higher NPP values exceeding 720 gC·m − 2 ·a −1 showed in North Zhangzhou city and lower values under 500 gC·m − 2 ·a −1 showed in the some areas of northeast Quanzhou city. Seasonal variations of NPP were large. It was about 45% of the total annual NPP in the three months in summer, and the NPP values were very low in winter. From 2009 to 2010, the value of annual NPP showed a slightly decrease trend, approximately 7.8% because the annual temperature for 2010 decline 13.6% compared with 2009 in despite of an increase in rainfall of about 34.3%. The results indicate that temperature was a main limiting factor on vegetation growth, but water is not a limiting factor in the rainy area

  3. Hepatoprotective and Antioxidant Activities of Tribulus Terrestris

    NARCIS (Netherlands)

    Harraz, Fathalla M; Ghazy, Nabila M; Hammoda, Hala M; Nafeaa, Abeer A.; Abdallah, Ingy I.

    2015-01-01

    Tribulus terrestris L. has been used in folk medicine throughout history. The present study examined the acute toxicity of the total ethanolic extract of T. Terrestris followed by investigation of the hepatoprotective activity of the total ethanolic extract and different fractions of the aerial

  4. Assessing the repeatability of terrestrial laser scanning for monitoring gully topography: A case study from Aratula, Queensland, Australia

    Science.gov (United States)

    Goodwin, Nicholas Robert; Armston, John; Stiller, Isaac; Muir, Jasmine

    2016-06-01

    Terrestrial laser scanning (TLS) technology is a powerful tool for quantifying gully morphology and monitoring change over time. This is due to the high sampling density, sub-centimetre positional accuracies (x, y, z), flexibility of survey configurations and ability to link multiple TLS scans together. However, to ensure correct interpretation of results, research is needed to test the repeatability of TLS derived products to quantify the accuracy and separate 'false' from 'true' geomorphic change. In this study, we use the RIEGL VZ400 scanner to test the repeatability of TLS datasets for mapping gully morphology. We then quantify change following a rainfall event of approximately 100 mm. Our study site, located in south-east Queensland, Australia was chosen to be challenging from a repeatability perspective with high topographic variability. The TLS data capture involved three sets of linked scans: one survey pre-rainfall, to be compared to two surveys post-rainfall acquired on consecutive days. Change is considered negligible in the two post-rainfall scans to test survey repeatability. To verify TLS accuracy, an independent dataset of gully extent and spot heights were acquired using traditional total station techniques. Results confirm that the TLS datasets can be registered multi-temporally at sub-centimetre levels of accuracy in three dimensions. Total station and TLS elevation samples showed strong agreement with a mean error and standard deviation (SD) of residuals equal to 0.052 and 0.047 m, respectively (n = 889). Significantly, our repeatability tests found that return type and pulse deviation influence the accuracy and repeatability of DEMs in gully environments. Analysis of consecutive day datasets showed that DEMs derived from first return data recorded 40% higher SD of residual error than DEMs using multiple return data. A significant empirical relationship between pulse deviation and the variance of residuals for repeat DEMs is also shown (r2 = 0

  5. Molecular analogs of the hemihelix: A computational study of chain molecules containing left- and right-handed helices

    Science.gov (United States)

    Pichierri, Fabio

    2014-08-01

    Using density functional theory (DFT) we design two novel chain molecules containing a left-handed (thia)helicene unit connected to a right-handed (thia)helicene unit via a phosphoroussbnd phosphorous (Psbnd P) bond. These chains represent the molecular analogs of the novel hemihelix structure recently discovered by a group of Harvard University scientists. The HOMO and LUMO levels of the heterochiral chains, termed hemihelicenes, are localized on the left- and right-handed blocks, respectively. In contrast, the frontier orbitals of the chains containing homochiral (thia)helicenes connected by a Psbnd P bond are delocalized all over the chain.

  6. Patterns of Analogical Reasoning among Beginning Readers

    Science.gov (United States)

    Farrington-Flint, Lee; Wood, Clare; Canobi, Katherine H.; Faulkner, Dorothy

    2004-01-01

    Despite compelling evidence that analogy skills are available to beginning readers, few studies have actually explored the possibility of identifying individual differences in young children's analogy skills in early reading. The present study examined individual differences in children's use of orthographic and phonological relations between…

  7. Troubleshooting analog circuits

    CERN Document Server

    Pease, Robert A

    1991-01-01

    Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other

  8. Impacts of land use and cover change on terrestrial carbon stocks and the micro-climate over urban surface: a case study in Shanghai, China

    Science.gov (United States)

    Zhang, F.; Zhan, J.; Bai, Y.

    2016-12-01

    Land use and cover change is the key factor affecting terrestrial carbon stocks and micro-climate, and their dynamics not only in regional ecosystems but also in urbanized areas. Using the typical fast-growing city of Shanghai, China as a case study, this paper explored the relationships between terrestrial carbon stocks, micro-climate and land cover within an urbanized area. The main objectives were to assess variation in soil carbon stocks and local climate conditions across terrestrial land covers with different intensities of urban development, and quantify spatial distribution and dynamic variation of carbon stocks and microclimate in response to urban land use and cover change. On the basis of accurate spatial datasets derived from a series of Landsat TM images during the years 1988 to 2010 and reliable estimates of urban climate and soil carbon stocks using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, our results showed that carbon stocks per unit area in terrestrial land covers decreased and urban temperature increased with increasing intensity of urban development. Urban land use and cover change and sealing of the soil surface created hotspots for losses in carbon stocks. Total carbon stocks in Shanghai decreased by about 30%-35%, representing a 1.5% average annual decrease, and the temperature increased by about 0.23-0.4°/10a during the past 20 years. We suggested potential policy measures to mitigate negative effects of land use and cover change on carbon stocks and microclimate in urbanized areas.

  9. Tree crown structural characterization: A study using terrestrial laser scanning and three-dimensional radiative transfer modeling

    Science.gov (United States)

    Moorthy, Inian

    Spectroscopic observational data for vegetated environments, have been coupled with 3D physically-based radiative transfer models for retrievals of biochemical and biophysical indicators of vegetation health and condition. With the recent introduction of Terrestrial Laser Scanning (TLS) units, there now exists a means of rapidly measuring intricate structural details of vegetation canopies, which can also serve as input into 3D radiative transfer models. In this investigation, Intelligent Laser Ranging and Imaging System (ILRIS-3D) data was acquired of individual tree crowns in laboratory, and field-based experiments. The ILRIS-3D uses the Time-Of-Flight (TOF) principle to measure the distances of objects based on the time interval between laser pulse exitance and return, upon reflection from an object. At the laboratory-level, this exploratory study demonstrated and validated innovative approaches for retrieving crown-level estimates of Leaf Area Index (LAI) (r2 = 0.98, rmse = 0.26m2/m2), a critical biophysical parameter for vegetation monitoring and modeling. These methods were implemented and expanded in field experiments conducted in olive (Olea europaea L.) orchards in Cordoba, Spain, where ILRIS-3D observations for 24 structurally-variable trees were made. Robust methodologies were developed to characterize diagnostic architectural parameters, such as tree height (r2 = 0.97, rmse = 0.21m), crown width (r 2 = 0.98, rmse = 0.12m), crown height (r2 = 0.81, rmse = 0.11m), crown volume (r2 = 0.99, rmse = 2.6m3), and LAI (r2 = 0.76, rmse = 0.27m2/ m2). These parameters were subsequently used as direct inputs into the Forest LIGHT (FLIGHT) 3D ray tracing model for characterization of the spectral behavior of the olive crowns. Comparisons between FLIGHT-simulated spectra and measured data showed small differences in the visible (measurements were significantly correlated to TLS-derived tree crown complexity metrics. The specific implications of internal crown

  10. Environmental and radiological safety studies. Interaction of 238PuO2 heat sources with terrestrial and aquatic environments. Progress report, July 1-September 30, 1980

    International Nuclear Information System (INIS)

    Waterbury, G.R.

    1981-01-01

    The containers for 238 PuO 2 heat sources in radioisotope thermoelectric generators are designed with large safety factors to ensure that they will withstand reentry from orbit and impact with the earth and safely contain the nuclear fuel until it is recovered. Existing designs have proved more than adequately safe, but the Space and Terrestrial Division of the Department of Energy Office of Advanced Nuclear Systems and Projects continually seeks more information about the heat sources to improve their safety. The work discussed here includes studies of the effects on the heat source of terrestrial and aquatic environments to obtain data for design of even safer systems. The data obtained in several ongoing experiments are presented; these data tables will be updated quarterly. Discussions of experimental details are minimized and largely repetitive in succeeding reports. Compilations of usable data generated in each experiment are emphasized. These compilations include data from environmental chamber experiments that simulate terrestrial conditions, experiments to measure PuO 2 dissolution rates, soil column experiments to measure sorption of plutonium by soils, and several aquatic experiments

  11. Synthesis and Docking Studies of 2,4,6-Trihydroxy-3-Geranylacetophenone Analogs as Potential Lipoxygenase Inhibitor

    Directory of Open Access Journals (Sweden)

    Chean Hui Ng

    2014-08-01

    Full Text Available The natural product molecule 2,4,6-trihydroxy-3-geranyl-acetophenone (tHGA isolated from the medicinal plant Melicope ptelefolia was shown to exhibit potent lipoxygenase (LOX inhibitory activity. It is known that LOX plays an important role in inflammatory response as it catalyzes the oxidation of unsaturated fatty acids, such as linoleic acid to form hydroperoxides. The search for selective LOX inhibitors may provide new therapeutic approach for inflammatory diseases. Herein, we report the synthesis of tHGA analogs using simple Friedel-Craft acylation and alkylation reactions with the aim of obtaining a better insight into the structure-activity relationships of the compounds. All the synthesized analogs showed potent soybean 15-LOX inhibitory activity in a dose-dependent manner (IC50 = 10.31–27.61 μM where compound 3e was two-fold more active than tHGA. Molecular docking was then applied to reveal the important binding interactions of compound 3e in soybean 15-LOX binding site. The findings suggest that the presence of longer acyl bearing aliphatic chain (5Cs and aromatic groups could significantly affect the enzymatic activity.

  12. Analog circuits cookbook

    CERN Document Server

    Hickman, Ian

    2013-01-01

    Analog Circuits Cookbook presents articles about advanced circuit techniques, components and concepts, useful IC for analog signal processing in the audio range, direct digital synthesis, and ingenious video op-amp. The book also includes articles about amplitude measurements on RF signals, linear optical imager, power supplies and devices, and RF circuits and techniques. Professionals and students of electrical engineering will find the book informative and useful.

  13. FGF growth factor analogs

    Science.gov (United States)

    Zamora, Paul O [Gaithersburg, MD; Pena, Louis A [Poquott, NY; Lin, Xinhua [Plainview, NY; Takahashi, Kazuyuki [Germantown, MD

    2012-07-24

    The present invention provides a fibroblast growth factor heparin-binding analog of the formula: ##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, X, Y and Z are as defined, pharmaceutical compositions, coating compositions and medical devices including the fibroblast growth factor heparin-binding analog of the foregoing formula, and methods and uses thereof.

  14. Natural analogs in the host rock salt. Pt. 1. General study (2011). Pt. 2. Detail studies (2012-2013); Natuerliche Analoga im Wirtsgestein Salz. T. 1. Generelle Studie (2011). T. 2. Detailstudien (2012-2013)

    Energy Technology Data Exchange (ETDEWEB)

    Brasser, Thomas; Fahrenholz, Christine; Kull, Herbert; Meleshyn, Artur; Moenig, Heike; Noseck, Ulrich; Schoenwiese, Dagmar; Wolf, Jens

    2014-12-15

    The first part of the project ISIBELII on natural analogs in the host rock salt included a summary of available studies on the topic to be used in a safety analysis for a final repository for heat generating radioactive waste. In 2012 the results of the preliminary safety analysis Gorleben was available, including results on the fracturing of anhydrite, the formation of cryogenic gaps and the influence of earthquakes. The requirements for the barrier system have been modified due to the safety requirements for the final disposal of heat-generating radioactive wastes valid since 2010. For containers the functionality gas to be demonstrated for 500 years. The following issues are covered: natural analogs for the integrity demonstration of the geological barrier, natural analogs for the integrity demonstration of geotechnical barriers, natural analogs for the evaluation of release scenarios. The detail studies include anhydrite fracturing, salt grit compaction, chemical composition of fluid inclusions, thermal stability of salt rock, mechanical stability of salt rock, influence of earthquakes, qualified closures, iron corrosion, and microbial processes.

  15. Young Children's Analogical Reasoning in Science Domains

    Science.gov (United States)

    Haglund, Jesper; Jeppsson, Fredrik; Andersson, Johanna

    2012-01-01

    This exploratory study in a classroom setting investigates first graders' (age 7-8 years, N = 25) ability to perform analogical reasoning and create their own analogies for two irreversible natural phenomena: mixing and heat transfer. We found that the children who contributed actively to a full-class discussion were consistently successful at…

  16. Children's Use of Analogy during Collaborative Reasoning

    Science.gov (United States)

    Lin, Tzu-Jung; Anderson, Richard C.; Hummel, John E.; Jadallah, May; Miller, Brian W.; Nguyen-Jahiel, Kim; Morris, Joshua A.; Kuo, Li-Jen; Kim, Il-Hee; Wu, Xiaoying; Dong, Ting

    2012-01-01

    This microgenetic study examined social influences on children's development of analogical reasoning during peer-led small-group discussions of stories about controversial issues. A total of 277 analogies were identified among 7,215 child turns for speaking during 54 discussions from 18 discussion groups in 6 fourth-grade classrooms (N = 120; age…

  17. Electrical Circuits and Water Analogies

    Science.gov (United States)

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  18. Expert analogy use in a naturalistic setting

    Science.gov (United States)

    Kretz, Donald R.; Krawczyk, Daniel C.

    2014-01-01

    The use of analogy is an important component of human cognition. The type of analogy we produce and communicate depends heavily on a number of factors, such as the setting, the level of domain expertise present, and the speaker's goal or intent. In this observational study, we recorded economics experts during scientific discussion and examined the categorical distance and structural depth of the analogies they produced. We also sought to characterize the purpose of the analogies that were generated. Our results supported previous conclusions about the infrequency of superficial similarity in subject-generated analogs, but also showed that distance and depth characteristics were more evenly balanced than in previous observational studies. This finding was likely due to the nature of the goals of the participants, as well as the broader nature of their expertise. An analysis of analogical purpose indicated that the generation of concrete source examples of more general target concepts was most prevalent. We also noted frequent instances of analogies intended to form visual images of source concepts. Other common purposes for analogies were the addition of colorful speech, inclusion (i.e., subsumption) of a target into a source concept, or differentiation between source and target concepts. We found no association between depth and either of the other two characteristics, but our findings suggest a relationship between purpose and distance; i.e., that visual imagery typically entailed an outside-domain source whereas exemplification was most frequently accomplished using within-domain analogies. Overall, we observed a rich and diverse set of spontaneously produced analogical comparisons. The high degree of expertise within the observed group along with the richly comparative nature of the economics discipline likely contributed to this analogical abundance. PMID:25505437

  19. Expert Analogy Use in a Naturalistic Setting

    Directory of Open Access Journals (Sweden)

    Donald R Kretz

    2014-11-01

    Full Text Available The use of analogy is an important component of human cognition. The type of analogy we produce and communicate depends heavily on a number of factors, such as the setting, the level of domain expertise present, and the speaker’s goal or intent. In this observational study, we recorded economics experts during scientific discussion and examined the categorical distance and structural depth of the analogies they produced. We also sought to characterize the purpose of the analogies that were generated. Our results supported previous conclusions about the infrequency of superficial similarity in subject-generated analogs, but also showed that distance and depth characteristics were more evenly balanced than in previous observational studies. This finding was likely due to the nature of the goals of the participants, as well as the broader nature of their expertise. An analysis of analogical purpose indicated that the generation of concrete source examples of more general target concepts was most prevalent. We also noted frequent instances of analogies intended to form visual images of source concepts. Other common purposes for analogies were the addition of colorful speech, inclusion (i.e., subsumption of a target into a source concept, or differentiation between source and target concepts. We found no association between depth and either of the other two characteristics, but our findings suggest a relationship between purpose and distance; i.e., that visual imagery typically entailed an outside-domain source whereas exemplification was most frequently accomplished using within-domain analogies. Overall, we observed a rich and diverse set of spontaneously produced analogical comparisons. The high degree of expertise within the observed group along with the richly comparative nature of the economics discipline likely contributed to this analogical abundance.

  20. Introduced Terrestrial Species (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data represent predicted future potential distributions of terrestrial plants, animals, and pathogens non-native to the Middle-Atlantic region. These data are...

  1. Terrestrial ecosystems and biodiversity

    CSIR Research Space (South Africa)

    Davis-Reddy, Claire

    2017-10-01

    Full Text Available Ecoregions Terrestrial Biomes Protected Areas Climate Risk and Vulnerability: A Handbook for Southern Africa | 75 7.2. Non-climatic drivers of ecosystem change 7.2.1. Land-use change, habitat loss and fragmentation Land-use change and landscape... concentrations of endemic plant and animal species, but these mainly occur in areas that are most threatened by human activity. Diverse terrestrial ecosystems in the region include tropical and sub-tropical forests, deserts, savannas, grasslands, mangroves...

  2. Study on characteristics of the aperture-averaging factor of atmospheric scintillation in terrestrial optical wireless communication

    Science.gov (United States)

    Shen, Hong; Liu, Wen-xing; Zhou, Xue-yun; Zhou, Li-ling; Yu, Long-Kun

    2018-02-01

    In order to thoroughly understand the characteristics of the aperture-averaging effect of atmospheric scintillation in terrestrial optical wireless communication and provide references for engineering design and performance evaluation of the optics system employed in the atmosphere, we have theoretically deduced the generally analytic expression of the aperture-averaging factor of atmospheric scintillation, and numerically investigated characteristics of the apertureaveraging factor under different propagation conditions. The limitations of the current commonly used approximate calculation formula of aperture-averaging factor have been discussed, and the results showed that the current calculation formula is not applicable for the small receiving aperture under non-uniform turbulence link. Numerical calculation has showed that aperture-averaging factor of atmospheric scintillation presented an exponential decline model for the small receiving aperture under non-uniform turbulent link, and the general expression of the model was given. This model has certain guiding significance for evaluating the aperture-averaging effect in the terrestrial optical wireless communication.

  3. Microstructure and Macrosegregation Study of Directionally Solidified Al-7Si Samples Processed Terrestrially and Aboard the International Space Station

    Science.gov (United States)

    Angart, Samuel; Erdman, R. G.; Poirier, David R.; Tewari, S.N.; Grugel, R. N.

    2014-01-01

    This talk reports research that has been carried out under the aegis of NASA as part of a collaboration between ESA and NASA for solidification experiments on the International Space Station (ISS). The focus has been on the effect of convection on the microstructural evolution and macrosegregation in hypoeutectic Al-Si alloys during directional solidification (DS). The DS-experiments have been carried out under 1-g at Cleveland State University (CSU) and under low-g on the International Space Station (ISS). The thermal processing-history of the experiments is well defined for both the terrestrially-processed samples and the ISS-processed samples. We have observed that the primary dendrite arm spacings of two samples grown in the low-g environment of the ISS show good agreement with a dendrite-growth model based on diffusion controlled growth. The gravity-driven convection (i.e., thermosolutal convection) in terrestrially grown samples has the effect of decreasing the primary dendrite arm spacings and causes macrosgregation. In order to process DS-samples aboard the ISS, dendritic-seed crystals have to partially remelted in a stationary thermal gradient before the DS is carried out. Microstructural changes and macrosegregation effects during this period are described.

  4. The Digital Dividend of Terrestrial Broadcasting

    CERN Document Server

    Beutler, Roland

    2012-01-01

    The “digital revolution” of the last two decades has pervaded innumerable aspects of our daily lives and changed our planet irreversibly. The shift from analog to digital broadcasting has facilitated a seemingly infinite variety of new applications—audience interactivity being but one example. The greater efficiency and compression of digital media have endowed broadcasters with a “digital dividend” of spare transmission capacity over and above the requirements of terrestrial broadcasting. The question is, who will use it, and how? Comparing the European experience with that of broadcasters elsewhere in the world, the author sketches the current status of international frequency management, quantifies the value of the “dividend” itself, analyzes the details of the analog-to-digital switchovers already completed, and posits what the future holds for the sector. As we grapple with new devices, inconceivable a mere generation ago, that allow us to access digital media instantly, anywhere and at any...

  5. Characterization of nanomaterial test solutions for terrestrial plant dose-response studies: A comparative study of DLS and SAXS

    Science.gov (United States)

    Industrial applications of nanomaterials have expanded at an increasing rate in recent years, accompanied by the need for comprehensive toxicological assessments to establish environmental health and safety standards. Relatively few studies have examined the effects of nanoparti...

  6. MODIS-derived terrestrial primary production [chapter 28

    Science.gov (United States)

    Maosheng Zhao; Steven Running; Faith Ann Heinsch; Ramakrishna Nemani

    2011-01-01

    Temporal and spatial changes in terrestrial biological productivity have a large impact on humankind because terrestrial ecosystems not only create environments suitable for human habitation, but also provide materials essential for survival, such as food, fiber and fuel. A recent study estimated that consumption of terrestrial net primary production (NPP; a list of...

  7. The Mojave Desert: A Martian Analog Site for Future Astrobiology Themed Missions

    Science.gov (United States)

    Salas, E.; Abbey, W.; Bhartia, R.; Beegle, L. W.

    2011-01-01

    Astrobiological interest in Mars is highlighted by evidence that Mars was once warm enough to have liquid water present on its surface long enough to create geologic formations that could only exist in the presense of extended fluvial periods. These periods existed at the same time life on Earth arose. If life began on Mars as well during this period, it is reasonable to assume it may have adapted to the subsurface as environments at the surface changed into the inhospitable state we find today. If the next series of Mars missions (Mars Science Laboratory, the ExoMars Trace Gas Orbiter proposed for launch in 2016, and potential near surface sample return) fail to discover either extinct or extant life on Mars, a subsurface mission would be necessary to attempt to "close the book" on the existence of martian life. Mars is much colder and drier than Earth, with a very low pressure CO2 environment and no obvious habitats. Terrestrial regions with limited precipitation, and hence reduced active biota, are some of the best martian low to mid latitude analogs to be found on Earth, be they the Antarctic dry valleys, the Atacama or Mojave Deserts. The Mojave Desert/Death Valley region is considered a Mars analog site by the Terrestrial Analogs Panel of the NSF-sponsored decadal survey; a field guide was even developed and a workshop was held on its applicability as a Mars analog. This region has received a great deal of attention due to its accessibility and the variety of landforms and processes observed relevant to martian studies.

  8. Archaeological analogous and industrials for deep storage: study of the archaeological metallic piece; Analogos arqueologicos e industriales para almacenamientos profundos: estudio de piezas arqueologicas metalicas

    Energy Technology Data Exchange (ETDEWEB)

    Criado Portal, A J; Martinez Garcia, J A; Calabres Molina, R; Garcia abajo, A; Penco Valenzuela, F; Lecanda Esteban, J A; Garcia Bartual, M; Jimenez Gonzalez, J M; Bravo Munoz, E; Rodriguez Lobo, L M; Fernandez Cascos, T; Fernandes Cordero, O; Montero Ruiz, I

    2000-07-01

    The aim of present research is to obtain information about archaeological analogous of iron and steel, useful for the model of deep geological repository (AGP). The analogous examined have remained buried between 1400 and 2400 years, in very assorted geochemical environments. The extraction of the archaeological pieces has been accomplished according to normalised protocols, trying to carry to the laboratory so the piece as its burial environment, avoiding all possible pollution. Trying to the archaeological analogous could provide valuable information to the AGP model, the study has been directed to related the physical-chemical characteristics of the terrain respect to the deterioration of the archaeological metallic piece. The geology of the surrounding terrain to the archaeological deposit, the geomorphological study of the terrain and data from the analysis of ground: pH, wetness, porosity, organic matter contents, bacteria presence, sulphates, carbonates, chlorides, etc., have allowed to explain the physical-chemical phenomena suffered by the archaeological iron and steel pieces. Also, an exhaustive study of the archaeological piece has been accomplished, concerning the microstructure of the corrosion layer and of the not deteriorated metallic rest. Obtained information concerns different items, such as corrosion velocity and formations of oxide layers, diffusion of chemical elements from the corrosion layer to the metal and viceversa, and structural changes in oxide layers and in the metallic remains by structural ageing. Obtained data have allowed to develop a mathematical model for calculation of corrosion velocity in buried iron and steels, based on physical-chemical variables of grounds, chemical composition and thermomechanical treatment given to the metal during its manufacture. (Author)

  9. Computational approaches to analogical reasoning current trends

    CERN Document Server

    Richard, Gilles

    2014-01-01

    Analogical reasoning is known as a powerful mode for drawing plausible conclusions and solving problems. It has been the topic of a huge number of works by philosophers, anthropologists, linguists, psychologists, and computer scientists. As such, it has been early studied in artificial intelligence, with a particular renewal of interest in the last decade. The present volume provides a structured view of current research trends on computational approaches to analogical reasoning. It starts with an overview of the field, with an extensive bibliography. The 14 collected contributions cover a large scope of issues. First, the use of analogical proportions and analogies is explained and discussed in various natural language processing problems, as well as in automated deduction. Then, different formal frameworks for handling analogies are presented, dealing with case-based reasoning, heuristic-driven theory projection, commonsense reasoning about incomplete rule bases, logical proportions induced by similarity an...

  10. Structure problems in the analog computation

    International Nuclear Information System (INIS)

    Braffort, P.L.

    1957-01-01

    The recent mathematical development showed the importance of elementary structures (algebraic, topological, etc.) in abeyance under the great domains of classical analysis. Such structures in analog computation are put in evidence and possible development of applied mathematics are discussed. It also studied the topological structures of the standard representation of analog schemes such as additional triangles, integrators, phase inverters and functions generators. The analog method gives only the function of the variable: time, as results of its computations. But the course of computation, for systems including reactive circuits, introduces order structures which are called 'chronological'. Finally, it showed that the approximation methods of ordinary numerical and digital computation present the same structure as these analog computation. The structure analysis permits fruitful comparisons between the several domains of applied mathematics and suggests new important domains of application for analog method. (M.P.)

  11. Harmonic development of tide-generating potential of terrestrial planets

    Science.gov (United States)

    Kudryavtsev, Sergey M.

    2008-08-01

    The aim of this study is to obtain high-accurate harmonic developments of the tide-generating potential (TGP) of Mercury, Venus and Mars. The planets’ TGP values have been first calculated on the base of DE/LE-406 numerical planetary/lunar ephemerides over a long period of time and then processed by a new spectral analysis method. According to this method the development is directly made to Poisson series where both amplitudes and arguments of the series’ terms are high-degree polynomials of time. A new harmonic development of Mars TGP is made over the time period 1900 AD 2100 AD and includes 767 second-order Poisson series’ terms of minimum amplitude equal to 10-7 m2 s-2. Analogous series composing both Mercury and Venus TGP harmonic models are built over the time period 1000 AD 3000 AD and include 1,061 and 693 terms, respectively. A modification of the standard HW95 format for representation of the terrestrial planets’ TGP is proposed. The number of terms in the planets’ TGP models transformed to the modified HW95 format is 650 for Mercury, 422 for Venus, and 480 for Mars. The quality of the new developments of the terrestrial planets’ TGP is better than that of the similar developments obtained earlier.

  12. CMOS analog circuit design

    CERN Document Server

    Allen, Phillip E

    1987-01-01

    This text presents the principles and techniques for designing analog circuits to be implemented in a CMOS technology. The level is appropriate for seniors and graduate students familiar with basic electronics, including biasing, modeling, circuit analysis, and some familiarity with frequency response. Students learn the methodology of analog integrated circuit design through a hierarchically-oriented approach to the subject that provides thorough background and practical guidance for designing CMOS analog circuits, including modeling, simulation, and testing. The authors' vast industrial experience and knowledge is reflected in the circuits, techniques, and principles presented. They even identify the many common pitfalls that lie in the path of the beginning designer--expert advice from veteran designers. The text mixes the academic and practical viewpoints in a treatment that is neither superficial nor overly detailed, providing the perfect balance.

  13. Analogical Reasoning in Geometry Education

    Science.gov (United States)

    Magdas, Ioana

    2015-01-01

    The analogical reasoning isn't used only in mathematics but also in everyday life. In this article we approach the analogical reasoning in Geometry Education. The novelty of this article is a classification of geometrical analogies by reasoning type and their exemplification. Our classification includes: analogies for understanding and setting a…

  14. Digital and analog communication systems

    Science.gov (United States)

    Shanmugam, K. S.

    1979-01-01

    The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.

  15. Analogs for transuranic elements

    International Nuclear Information System (INIS)

    Weimer, W.C.; Laul, J.C.; Kutt, J.C.

    1981-01-01

    A combined theoretical and experimental approach is being used to estimate the long-term environmental and biogeochemical behaviors of selected transuranic elements. The objective of this research is to estimate the effect that long-term (hundreds of years) environmental weathering has on the behavior of the transuranic elements americium and curium. This is achieved by investigating the actual behavior of naturally occurring rare earth elements, especially neodymium, that serve as transuranic analogs. Determination of the analog element behavior provides data that can be used to estimate the ultimate availability to man of transuranic materials released into the environment

  16. Nonequilibrium molecular dynamics study of ring polymer melts under shear and elongation flows: A comparison with their linear analogs

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jeongha; Kim, Jinseong; Baig, Chunggi, E-mail: cbaig@unist.ac.kr [Department of Chemical Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798 (Korea, Republic of)

    2016-07-15

    We present detailed results for the structural and rheological properties of unknotted and unconcatenated ring polyethylene (PE) melts under shear and elongation flows via direct atomistic nonequilibrium molecular dynamics simulations. Short (C{sub 78}H{sub 156}) and long (C{sub 400}H{sub 800}) ring PE melts were subjected to planar Couette flow (PCF) and planar elongational flow (PEF) across a wide range of strain rates from linear to highly nonlinear flow regimes. The results are analyzed in detail through a direct comparison with those of the corresponding linear polymers. We found that, in comparison to their linear analogs, ring melts possess rather compact chain structures at or near the equilibrium state and exhibit a considerably lesser degree of structural deformation with respect to the applied flow strength under both PCF and PEF. The large structural resistance of ring polymers against an external flow field is attributed to the intrinsic closed-loop configuration of the ring and the topological constraint of nonconcatenation between ring chains in the melt. As a result, there appears to be a substantial discrepancy between ring and linear systems in terms of their structural and rheological properties such as chain orientation, the distribution of chain dimensions, viscosity, flow birefringence, hydrostatic pressure, the pair correlation function, and potential interaction energies. The findings and conclusions drawn in this work would be a useful guide in future exploration of the characteristic dynamical and relaxation mechanisms of ring polymers in bulk or confined systems under flowing conditions.

  17. Experimental Acid Weathering of Fe-Bearing Mars Analog Minerals and Rocks: Implications for Aqueous Origin of Hematite-Bearing Sediments in Meridiani Planum, Mars

    Science.gov (United States)

    Golden, D. C.; Koster, A. M.; Ming, D. W.; Morris, R. V.; Mertzman, S. A.

    2011-01-01

    A working hypothesis for Meridiani evaporite formation involves the evaporation of fluids derived from acid weathering of Martian basalts and subsequent diagenesis [1, 2]. However, there are no reported experimental studies for the formation of jarosite and gray hematite (spherules), which are characteristic of Meridiani rocks from Mars analog precursor minerals. A terrestrial analog for hematite spherule formation from basaltic rocks under acidic hydrothermal conditions has been reported [3], and we have previously shown that the hematite spherules and jarosite can be synthetically produced in the laboratory using Fe3+ -bearing sulfate brines under hydrothermal conditions [4]. Here we expand and extend these studies by reacting Mars analog minerals with sulfuric acid to form Meridiani-like rock-mineral compositions. The objective of this study is to provide environmental constraints on past aqueous weathering of basaltic materials on Mars.

  18. A segmentation approach for a delineation of terrestrial ecoregions

    Science.gov (United States)

    Nowosad, J.; Stepinski, T.

    2017-12-01

    Terrestrial ecoregions are the result of regionalization of land into homogeneous units of similar ecological and physiographic features. Terrestrial Ecoregions of the World (TEW) is a commonly used global ecoregionalization based on expert knowledge and in situ observations. Ecological Land Units (ELUs) is a global classification of 250 meters-sized cells into 4000 types on the basis of the categorical values of four environmental variables. ELUs are automatically calculated and reproducible but they are not a regionalization which makes them impractical for GIS-based spatial analysis and for comparison with TEW. We have regionalized terrestrial ecosystems on the basis of patterns of the same variables (land cover, soils, landform, and bioclimate) previously used in ELUs. Considering patterns of categorical variables makes segmentation and thus regionalization possible. Original raster datasets of the four variables are first transformed into regular grids of square-sized blocks of their cells called eco-sites. Eco-sites are elementary land units containing local patterns of physiographic characteristics and thus assumed to contain a single ecosystem. Next, eco-sites are locally aggregated using a procedure analogous to image segmentation. The procedure optimizes pattern homogeneity of all four environmental variables within each segment. The result is a regionalization of the landmass into land units characterized by uniform pattern of land cover, soils, landforms, climate, and, by inference, by uniform ecosystem. Because several disjoined segments may have very similar characteristics, we cluster the segments to obtain a smaller set of segment types which we identify with ecoregions. Our approach is automatic, reproducible, updatable, and customizable. It yields the first automatic delineation of ecoregions on the global scale. In the resulting vector database each ecoregion/segment is described by numerous attributes which make it a valuable GIS resource for

  19. The Role of Terrestrial Inputs of Organic Matter in Arctic Lagoons: Comparative Studies from Open-Water and Ice-Covered Periods

    Science.gov (United States)

    Dunton, K. H.; McClelland, J. W.; Connelly, T.; Linn, S.; Khosh, M.

    2012-12-01

    Coastal ecosystems of the Arctic receive extraordinarily large quantities of terrestrial organic matter through river discharge and shoreline erosion. This organic matter, both in dissolved and particulate form, may provide an important carbon and energy subsidy that supports and maintains heterotrophic activity and food webs in coastal waters, especially in the lagoons. Recent food web studies using stable isotopes confirm the significant assimilation of terrestrial organic matter, based on the depletion in both 13C and 15N content of invertebrate and vertebrate consumers collected in eastern Beaufort Sea lagoons vs. offshore waters. Our current work specifically focuses on a set of 12 field sites along the eastern Alaskan Beaufort Sea coast, from Barter Island to Demarcation Bay. To examine linkages between biological communities and organic matter inputs from land, we compared sites ranging from lagoons to open coastal systems that receive differing amounts of freshwater runoff and also differ markedly in their exchange characteristics with shelf waters. Our temporal and spatial effort included field sampling during the ice covered period in a number of lagoons characterized by differences in their exchange characteristics with the nearshore shelf. Our preliminary chemical and biological measurements, the first of their kind in arctic coastal lagoons, reveal that lagoon benthos can become hypersaline (43) and net heterotrophic (values to 30% oxygen saturation) during winter, before rebounding during the period of ice break-up to net autotrophic (>100% saturation) under continued hypersaline conditions. Measurements of water and sediment chemistry, benthic and water column community characteristics, and natural abundance isotopic tracers promise to reveal the dynamic nature of these productive lagoon ecosystems under different hydrologic conditions. The possible role of terrestrially derived carbon to arctic estuarine food webs is especially important in view of

  20. Microplastics in the terrestrial ecosystem: Implications for Lumbricus terrestris (Oligochaeta, Lumbricidae)

    NARCIS (Netherlands)

    Huerta Lwanga, Esperanza; Gertsen, H.F.; Gooren, H.; Peters, P.D.; Salanki, T.E.; Ploeg, van der M.J.C.; Besseling, E.; Koelmans, A.A.; Geissen, V.

    2016-01-01

    Plastic debris is widespread in the environment, but information on the effects of microplastics on terrestrial fauna is completely lacking. Here, we studied the survival and fitness of the earthworm Lumbricus terrestris (Oligochaeta, Lumbricidae) exposed to microplastics (Polyethylene, <150 μm)

  1. Reasoning through Instructional Analogies

    Science.gov (United States)

    Kapon, Shulamit; diSessa, Andrea A.

    2012-01-01

    This article aims to account for students' assessments of the plausibility and applicability of analogical explanations, and individual differences in these assessments, by analyzing properties of students' underlying knowledge systems. We developed a model of explanation and change in explanation focusing on knowledge elements that provide a…

  2. The Paradox of Analogy

    Directory of Open Access Journals (Sweden)

    David Botting

    2012-03-01

    Full Text Available I will show that there is a type of analogical reasoning that instantiates a pattern of reasoning in confirmation theory that is considered at best paradoxical and at worst fatal to the entire syntactical approach to confirmation and explanation. However, I hope to elaborate conditions under which this is a sound (although not necessarily strong method of reasoning.

  3. Analogy, explanation, and proof

    Science.gov (United States)

    Hummel, John E.; Licato, John; Bringsjord, Selmer

    2014-01-01

    People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic) whose truth was not even known prior to the existence of the explanation (proof). What do the cognitive operations underlying the inference that the milk is sour have in common with the proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This seemingly small difference poses a challenge to the task of marshaling our understanding of analogical reasoning to understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence. PMID:25414655

  4. How Analogy Drives Physics

    International Nuclear Information System (INIS)

    Hofstadter, Doug

    2004-01-01

    Many new ideas in theoretical physics come from analogies to older ideas in physics. For instance, the abstract notion of 'isospin' (or isotopic spin) originated in the prior concept of 'spin' (quantized angular momentum); likewise, the concept of 'phonon' (quantum of sound, or quantized collective excitation of a crystal) was based on the prior concept of 'photon' (quantum of light, or quantized element of the electromagnetic field). But these two examples, far from being exceptions, in fact represent the bread and butter of inventive thinking in physics. In a nutshell, intraphysics analogy-making -- borrowing by analogy with something already known in another area of physics -- is central to the progress of physics. The aim of this talk is to reveal the pervasiveness -- indeed, the indispensability -- of this kind of semi-irrational, wholly intuitive type of thinking (as opposed to more deductive mathematical inference) in the mental activity known as 'doing physics'. Speculations as to why wild analogical leaps are so crucial to the act of discovery in physics (as opposed to other disciplines) will be offered.

  5. Quantum Analog Computing

    Science.gov (United States)

    Zak, M.

    1998-01-01

    Quantum analog computing is based upon similarity between mathematical formalism of quantum mechanics and phenomena to be computed. It exploits a dynamical convergence of several competing phenomena to an attractor which can represent an externum of a function, an image, a solution to a system of ODE, or a stochastic process.

  6. Case studies to test: A framework for using structural, reactivity, metabolic and physicochemical similarity to evaluate the suitability of analogs for SAR-based toxicological assessments.

    Science.gov (United States)

    Blackburn, Karen; Bjerke, Donald; Daston, George; Felter, Susan; Mahony, Catherine; Naciff, Jorge; Robison, Steven; Wu, Shengde

    2011-06-01

    A process for evaluating analogs for use in SAR (Structure-Activity Relationship) assessments was previously published (Wu et al. 2010). Subsequently, this process has been updated to include a decision tree for estrogen binding (from US EPA) and flags for developmental and reproductive toxicity (DART). This paper presents the results of blinded case studies designed to test this updated framework. The results of these case studies support the conclusion that the process outlined by Wu et al. (2010) can be successfully applied to develop surrogate values for risk assessment. The read across results generated by the process were shown to be protective when compared to the actual toxicity data. Successful application of the approach requires significant expertise as well as discipline to not overstep the boundaries of the defined analogs and the rating system. The end result of this rigor can be the inability to read across all endpoints for all chemicals resulting in data gaps that cannot be filled using read across, however, this reflects the current state of the science and is preferable to making non-protective decisions. Future work will be targeted towards expanding read across capabilities. Two examples of a broader category approach are also shown. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Comparative evaluation of pressure generated on a simulated maxillary oral analog by impression materials in custom trays of different spacer designs: An in vitro study.

    Science.gov (United States)

    Chopra, Sakshi; Gupta, Narendra Kumar; Tandan, Amrit; Dwivedi, Ravi; Gupta, Swati; Agarwal, Garima

    2016-01-01

    Literature reveals that masticatory load on denture bearing tissues through complete dentures should be maximum on primary stress bearing areas and least on relief area in accordance with the histology of underlying tissues. A study to validate the existing beliefs was planned to compare the pressure on mucosa using selective pressure technique and minimal pressure technique, with the incorporation of two different impression materials utilizing the pressure sensors during secondary impression procedure. The study was performed using a maxillary analog. Three pressure sensors were imbedded in the oral analog, one in the mid palatine area and the other two in the right and left ridge crest. Custom trays of two different configurations were fabricated. The two impression materials tested were light body and zinc oxide eugenol. A total of 40 impressions were made. A constant weight of 1 kg was placed, and the pressure was recorded as initial and end pressures. A significant difference in the pressure produced using different impression materials was found (P changing the amount of pressure produced. The impression materials used also had a significant role to play on the pressures acting on the tissues during impression procedure. Light body VPS impression material may be recommended to achieve minimal pressure on the denture bearing tissues in both selective as well as minimal pressure techniques.

  8. Study of the Role of Terrestrial Processes in the Carbon Cycle Based on Measurements of the Abundance and Isotopic Composition of Atmospheric CO2

    Energy Technology Data Exchange (ETDEWEB)

    Piper, Stephen C; Keeling, Ralph F

    2012-01-03

    The main objective of this project was to continue research to develop carbon cycle relationships related to the land biosphere based on remote measurements of atmospheric CO2 concentration and its isotopic ratios 13C/12C, 18O/16O, and 14C/12C. The project continued time-series observations of atmospheric carbon dioxide and isotopic composition begun by Charles D. Keeling at remote sites, including Mauna Loa, the South Pole, and eight other sites. Using models of varying complexity, the concentration and isotopic measurements were used to study long-term change in the interhemispheric gradients in CO2 and 13C/12C to assess the magnitude and evolution of the northern terrestrial carbon sink, to study the increase in amplitude of the seasonal cycle of CO2, to use isotopic data to refine constraints on large scale changes in isotopic fractionation which may be related to changes in stomatal conductance, and to motivate improvements in terrestrial carbon cycle models. The original proposal called for a continuation of the new time series of 14C measurements but subsequent descoping to meet budgetary constraints required termination of measurements in 2007.

  9. Radiotracers in the study of marine food chains. The use of compartmental analysis and analog modelling in measuring utilization rates of particulate organic matter by benthic invertebrates

    International Nuclear Information System (INIS)

    Gremare, A.; Amouroux, J.M.; Charles, F.

    1991-01-01

    The present study assesses the problem of recycling when using radiotracers to quantify ingestion and assimilation rates of particulate organic matter by benthic invertebrates. The rapid production of dissolved organic matter and its subsequent utilization by benthic invertebrates constitutes a major bias in this kind of study. However recycling processes may also concern POM through the production and reingestion of faeces. The present paper shows that compartmental analysis of the diffusion kinetics of the radiotracer between the different compartments of the system studied and the analog modelling of the exchanges of radioactivity between compartments may be used in order to determine ingestion and assimilation rates. This method is illustrated by the study of a system composed of the bacteria Lactobacillus sp. and the filter-feeding bivalve Venerupis decussata. The advantages and drawbacks of this approach relative to other existing methods are briefly discussed. (Author)

  10. Terrestrial and extraterrestrial fullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Heymann, D.; Jenneskens, L.W.; Jehlicka, J; Koper, C.; Vlietstra, E. [Rice Univ, Houston, TX (United States). Dept. of Earth Science

    2003-07-01

    This paper reviews reports of occurrences of fullerenes in circumstellar media, interstellar media, meteorites, interplanetary dust particles (IDPs), lunar rocks, hard terrestrial rocks from Shunga (Russia), Sudbury (Canada) and Mitov (Czech Republic), coal, terrestrial sediments from the Cretaceous-Tertiary-Boundary and Pennian-Triassic-Boundary, fulgurite, ink sticks, dinosaur eggs, and a tree char. The occurrences are discussed in the context of known and postulated processes of fullerene formation, including the suggestion that some natural fullerenes might have formed from biological (algal) remains.

  11. In vitro and in vivo studies in Balb-c and nude mice of a new 177Lu-Bombesin analog developed for prostate tumor diagnosis and treatment

    International Nuclear Information System (INIS)

    Pujatti, Priscilla B.; Santos, Josefina S.; Couto, Renata M.; Araujo, Elaine B. de; Mengatti, Jair; Suzuki, Miriam F.

    2009-01-01

    In this work we describe the radiolabeling with 177 Lu and some properties of the novel bombesin analog BBNp6 - DOTA-X-BBN(6-14), where X is a spacer of six aminoacids. Bombesin (BBN) is an analog of human gastrin releasing peptide (GRP) isolated from the skin of the frog Bombina bombina in 1970. Development of radiolabeled BBN derivatives as agents for diagnostic imaging and systemic radiotherapy has increased considerable because of the observation that GRP receptors (GRPr) are over-expressed in a variety of human tumor cells, such as prostate tumor cells. 177 Lu-labeled peptides are attractive due to the excellent radiophysical properties and commercial availability of the radiometal. BBNp6 was labeled with high yield after reacting with 92.5 MBq of 177 LuCl3 at 90 deg C for 30 minutes and this mixture kept stable for more than 96 hours at 4 deg C and 1 hour in human plasma. In vivo studies showed a multicompartimental distribution model with fast blood clearance, mainly performed by renal pathway. In addition, 177 Lu-BBNp6 showed high affinity for PC-3 tumor xenografts, but not for pancreas and intestine (GRP positive tissues), suggesting its specificity and usefulness for prostate tumor treatment. Moreover, scintigraphic images showed that this derivative can also be a tool in this tumor diagnosis. So, BBNp6 is a promising radiopharmaceutical for prostate tumor imaging and treatment. (author)

  12. Pentagastrin analogs containing α-aminooxy acids

    International Nuclear Information System (INIS)

    Balaspiri, L.; Kovacs, L.; Kovacs, K.; Varga, L.; Varro, V.; Schoen, I.; Kisfaludy, L.

    1982-01-01

    Two 14 C-labelled pentagastrin analogs of different specific radioactivities, containing α-aminooxy acids, have been synthesised to study their biological effects in the gastro-intestinal tract. (U.K.)

  13. Quantum States Transfer by Analogous Bell States

    International Nuclear Information System (INIS)

    Mei Di; Li Chong; Yang Guohui; Song Heshan

    2008-01-01

    Transmitting quantum states by channels of analogous Bell states is studied in this paper. We analyze the transmitting process, constructed the probabilitic unitary operator, and gain the largest successful transfer quantum state probability.

  14. Studies on the Edible Terrestrial Snails Helix aspersa Muller Food Conversion Ratio in a Confined Microclimate System

    Directory of Open Access Journals (Sweden)

    Adrian Toader-Williams

    2010-05-01

    Full Text Available Terrestrial edible snail breeding is an agricultural activity that finds itself at pioneering stage in Romania. One of the species used in snail farming is Helix aspersa Muller. In order to accelerate their growth, farmers feed the snails with pumpkins as well as concentrated forage consisting of mix of flours to which calcium carbonate is added in order to supplement snails need for shell’s development. In a controlled microclimate environment we measured the average growth of six weeks old Helix aspersa Muller snails placed in four different plastic enclosures. The consumption of different type of foods within 24 hours period was measured. The wheat (60%, corn flour (20% and calcium carbonate (20% mix had a superior food conversion ratio (FCR of 4.80, whereas the second FCR registered 6.04 in the case of 53% pumpkin and 47% flour mix served in the same time followed by the pure fresh vegetable mix accounting for a FCR of 8.00 and by 19.02 when only the pumpkin has been administrated as meal. During the experiments the snails did not have access to soil, being known that soil is an integral part of their diet.

  15. A Comparative Study of the Applied Methods for Estimating Deflection of the Vertical in Terrestrial Geodetic Measurements

    Directory of Open Access Journals (Sweden)

    Luca Vittuari

    2016-04-01

    Full Text Available This paper compares three different methods capable of estimating the deflection of the vertical (DoV: one is based on the joint use of high precision spirit leveling and Global Navigation Satellite Systems (GNSS, a second uses astro-geodetic measurements and the third gravimetric geoid models. The working data sets refer to the geodetic International Terrestrial Reference Frame (ITRF co-location sites of Medicina (Northern, Italy and Noto (Sicily, these latter being excellent test beds for our investigations. The measurements were planned and realized to estimate the DoV with a level of precision comparable to the angular accuracy achievable in high precision network measured by modern high-end total stations. The three methods are in excellent agreement, with an operational supremacy of the astro-geodetic method, being faster and more precise than the others. The method that combines leveling and GNSS has slightly larger standard deviations; although well within the 1 arcsec level, which was assumed as threshold. Finally, the geoid model based method, whose 2.5 arcsec standard deviations exceed this threshold, is also statistically consistent with the others and should be used to determine the DoV components where local ad hoc measurements are lacking.

  16. Grazing livestock are exposed to terrestrial cyanobacteria

    OpenAIRE

    McGorum , Bruce C; Pirie , R Scott; Glendinning , Laura; McLachlan , Gerry; Metcalf , James S; Banack , Sandra A; Cox , Paul A; Codd , Geoffrey A

    2015-01-01

    While toxins from aquatic cyanobacteria are a well-recognised cause of disease in birds and animals, exposure of grazing livestock to terrestrial cyanobacteria has not been described. This study identified terrestrial cyanobacteria, predominantly Phormidium spp., in the biofilm of plants from most livestock fields investigated. Lower numbers of other cyanobacteria, microalgae and fungi were present on many plants. Cyanobacterial 16S rDNA, predominantly from Phormidium spp., was detected in al...

  17. Spatial vision in Bombus terrestris

    Directory of Open Access Journals (Sweden)

    Aravin eChakravarthi

    2016-02-01

    Full Text Available Bombus terrestris is one of the most commonly used insect models to investigate visually guided behavior and spatial vision in particular. Two fundamental measures of spatial vision are spatial resolution and contrast sensitivity. In this study, we report the threshold of spatial resolution in B. terrestris and characterize the contrast sensitivity function of the bumblebee visual system for a dual choice discrimination task. We trained bumblebees in a Y-maze experimental set-up to associate a vertical sinusoidal grating with a sucrose reward, and a horizontal grating with absence of a reward. Using a logistic psychometric function, we estimated a resolution threshold of 0.21 cycles deg-1 of visual angle. This resolution is in the same range but slightly lower than that found in honeybees (Apis mellifera and A. cerana and another bumblebee species (B. impatiens. We also found that the contrast sensitivity of B. terrestris was 1.57 for the spatial frequency 0.09 cycles deg-1 and 1.26. for 0.18 cycles deg-1.

  18. Radionuclides in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Bocock, K.L.

    1981-01-01

    This report summarizes information on the distribution and movement of radionuclides in semi-natural terrestrial ecosystems in north-west England with particular emphasis on inputs to, and outputs from ecosystems; on plant and soil aspects; and on radionuclides in fallout and in discharges by the nuclear industry. (author)

  19. Analog storage integrated circuit

    Science.gov (United States)

    Walker, J.T.; Larsen, R.S.; Shapiro, S.L.

    1989-03-07

    A high speed data storage array is defined utilizing a unique cell design for high speed sampling of a rapidly changing signal. Each cell of the array includes two input gates between the signal input and a storage capacitor. The gates are controlled by a high speed row clock and low speed column clock so that the instantaneous analog value of the signal is only sampled and stored by each cell on coincidence of the two clocks. 6 figs.

  20. Analogy, Explanation, and Proof

    Directory of Open Access Journals (Sweden)

    John eHummel

    2014-11-01

    Full Text Available People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic whose truth was not even known prior to the existence of the explanation (proof. What do the cognitive operations underlying the (inductive inference that the milk is sour have in common with the (deductive proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This small-seeming difference poses a challenge to the task of marshaling our understanding of analogical reasoning in the service of understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence.

  1. Design and synthesis of enantiomerically enriched, radiolabeled MK-801 analogs as potential radiotracers for imaging and autoradiographic studies of the NMDA receptor-ion channel complex

    International Nuclear Information System (INIS)

    Eng, W.S.; Burns, H.D.; Gibson, R.E.; Ransom, R.W.; Thorpe, H.; Fioravanit, C.; Britcher, S.F.; Magill, C.A.; Solomon, H.F.; Dannals, R.F.; Wilson, A.A.; Ravert, H.T.; Wagner, H.N.

    1989-01-01

    MK-801 is a potent, non-competitive antagonist for the N-methyl-D-asspartate (NMDA) receptor-ion channel complex. This complex is though to be involved in nerve cell damage in stroke patients when excess calcium is released through the activated channel. A thorough understanding of drug interactions with the NMDA receptor complex could lead to improved therapy for reducing hypoxic-ischemic neuronal injuries in stroke patients. Based on the results of extensive structure-activity studies, the authors have developed several enantiomerically enriched, radiolabeled analogs of MK-801, including: 3-1231-MK-801 for Single Photon Emission Computed tomography (SPECT); 3-1251-MK-801 for in-vivo and in-vitro autoradiography; 8-11C-MeO-MK-801 for Positron Emission Tomography (PET). Details of the synthesis of these radiotracers and their application to both in-vitro and in-vivo studies are described

  2. Fluvial Channel Networks as Analogs for the Ridge-Forming Unit, Sinus Meridiani, Mars

    Science.gov (United States)

    Wilkinson, M. J.; du Bois, J. B.

    2010-01-01

    Fluvial models have been generally discounted as analogs for the younger layered rock units of Sinus Meridiani. A fluvial model based on the large fluvial fan provides a possibly close analog for various features of the sinuous ridges of the etched, ridge-forming unit (RFU) in particular. The close spacing of the RFU ridges, their apparently chaotic orientations, and their organization in dense networks all appear unlike classical stream channel patterns. However, drainage patterns on large fluvial fans low-angle, fluvial aggradational features, 100s of km long, documented worldwide by us provide parallels. Some large fan characteristics resemble those of classical floodplains, but many differences have been demonstrated. One major distinction relevant to the RFU is that channel landscapes of large fans can dominate large areas (1.2 million km2 in one S. American study area). We compare channel morphologies on large fans in the southern Sahara Desert with ridge patterns in Sinus Meridiani (fig 1). Stream channels are the dominant landform on large terrestrial fans: they may equate to the ubiquitous, sinuous, elongated ridges of the RFU that cover areas region wide. Networks of convergent/divergent and crossing channels may equate to similar features in the ridge networks. Downslope divergence is absent in channels of terrestrial upland erosional landscapes (fig. 1, left), whereas it is common to both large fans (fig. 1, center) and RFU ridge patterns (fig 1, right downslope defined as the regional NW slope of Sinus Meridiani). RFU ridge orientation, judged from those areas apparently devoid of impact crater control, is broadly parallel with the regional slope (arrow, fig. 1, right), as is mean orientation of major channels on large fans (arrow, fig. 1, center). High densities per unit area characterize fan channels and martian ridges reaching an order of magnitude higher than those in uplands just upstream of the terrestrial study areas fig. 1. In concert with

  3. Component Processes in Analogical Reasoning

    Science.gov (United States)

    Sternberg, Robert J.

    1977-01-01

    Describes alternative theoretical positions regarding (a) the component information processes used in analogical reasoning and (b) strategies for combining these processes. Also presents results from three experiments on analogical reasoning. (Author/RK)

  4. Modeling the terrestrial N processes in a small mountain catchment through INCA-N: A case study in Taiwan.

    Science.gov (United States)

    Lu, Meng-Chang; Chang, Chung-Te; Lin, Teng-Chiu; Wang, Lih-Jih; Wang, Chiao-Ping; Hsu, Ting-Chang; Huang, Jr-Chuan

    2017-09-01

    Riverine dissolved inorganic nitrogen (DIN) is an important indicator of trophic status of aquatic ecosystems. High riverine DIN export in Taiwan, ~3800kg-Nkm -2 yr -1 , which is ~18 times higher than the global average, urges the need of thorough understanding of N cycling processes. We applied INCA-N (Integrated Nitrogen Catchment Model) to simulate riverine DIN export and infer terrestrial N processes using weekly rainwater and streamwater samples collected at the Fushan Experimental Forest (FEF) of northern Taiwan. Results showed that the modeled discharge and nitrate export are in good agreement with observations, suggesting the validity of our application. Based on our modeling, the three main N removal processes, in the order of descending importance, were plant uptake, riverine N transport and denitrification at FEF. The high plant uptake rate, 4920kg-Nkm -2 yr -1 , should have led to accumulation of large biomass but biomass at FEF was relatively small compared to other tropical forests, likely due to periodic typhoon disruptions. The low nitrate concentration but high DIN export highlights the importance of hydrological control over DIN export, particularly during typhoons. The denitrification rate, 750kg-Nkm -2 yr -1 , at FEF was also low compared to other tropical forest ecosystems, likely resulting from quick water drainage through the coarse-loamy top soils. The high DIN export to atmospheric deposition ratio, 0.45, suggests that FEF may be in advanced stages of N excess. This simulation provides useful insights for establishing monitoring programs and improves our understanding N cycling in subtropical watersheds. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Potential and Actual Terrestrial Rabies Exposures in People and Domestic Animals, Upstate South Carolina, 1994–2004: A Surveillance Study

    Directory of Open Access Journals (Sweden)

    Foppa Ivo M

    2009-02-01

    Full Text Available Abstract Background Although there has been a reduction of rabies in pets and domestic animals during recent decades in the United States, rabies remains enzootic among bats and several species of terrestrial wildlife. Spillover transmission of wildlife rabies to domestic animals therefore remains a public health threat Methods Retrospective analysis of surveillance data of reported animal incidents (bites, scratches, mucous membrane contacts from South Carolina, 1995 to 2003, was performed to assess risk factors of potential rabies exposures among human and animal victims. Results Dogs and cats contributed the majority (66.7% and 26.4%, respectively of all reported incidents, with stray dogs and cats contributing 9.0% and 15.1 respectively. Current rabies vaccination status of dogs and cats (40.2% and 13.8%, respectively were below World Health Organization recommended levels. Owned cats were half as likely to be vaccinated for rabies as dogs (OR 0.53, 95% CI 0.48, 0.58. Animal victims were primarily exposed to wildlife (83.0%, of which 27.5% were rabid. Almost 90% of confirmed rabies exposures were due to wildlife. Skunks had the highest prevalence of rabies among species of exposure animals (63.2%. Among rabid domestic animals, stray cats were the most commonly reported (47.4%. Conclusion While the majority of reported potential rabies exposures are associated with dog and cat incidents, most rabies exposures derive from rabid wildlife. Stray cats were most frequently rabid among domestic animals. Our results underscore the need for improvement of wildlife rabies control and the reduction of interactions of domestic animals, including cats, with wildlife.

  6. [Asu(1,7)E-CT, an analog of eel calcitonin. A comparative study in man with reference to other synthetic calcitonins].

    Science.gov (United States)

    Caniggia, A; Nuti, R; Vattimo, A; Galli, M; Turchetti, V; Franci, B; Martorelli, T; Righi, G

    1983-04-28

    (Asu) E-CT is a deaminodicarba-analog of the synthetic eel-calcitonin (E-CT) that shows specific activity and the potency reasonably high in comparison with that of the most potent natural hormone. The structure of its molecule indicates that the disulphide bond in calcitonins is not essential for the biological activity but only for the maintenance of the specific conformation by forming an intramolecular bridge. The instability of calcitonins should mainly be attributed to the presence of the disulfide bond and (Asu)E-CT proved to be more stable "in vitro" than native calcitonins. The more prolonged hypocalcemic effect of E-CT and its aminosuberic analog (Asu)E-CT has been accounted for to a greater stability of and persistence at the receptor site. (Asu) E-CT has been largely studied in Japan on experimental animals and successfully used in the treatment of hypercalcemia in man. On the contrary investigations on human administration of this analog are very scarce. The present paper reports studies carried out in normal subjects and Paget's disease patients to investigate the effects of (Asu)E-CT in man in comparison with the effects of synthetic human calcitonin (H-CT) and synthetic salmon calcitonin (S-CT). Two different experimental procedures have been used: 1) rapid intravenous injection of (Asu)E-CT (80 MRC. U.) or respectively of H-CT and S-CT (100 MRC. U.) in 15 subjects (7 normals and 8 with Paget's disease); 2) slow 7 days continuous subcutaneous infusion of similar daily amounts of (Asu)E-CT, H-CT and S-CT administered by a microjet pump device in 21 subjects (7 normals and 14 with Paget's disease). The intravenous administration of (Asu)E-CT induced a rapid and persistent decrease in total plasma calcium, ionized calcium and plasma phosphate that was more evident in Paget's disease patients than in normal subjects. No clearly cut differences have been observed with the hypocalcemic and hypophosphatemic effect of H-CT and S-CT administered

  7. Linking animals aloft with the terrestrial landscape

    Science.gov (United States)

    Buler, Jeffrey J.; Barrow, Wylie; Boone, Matthew; Dawson, Deanna K.; Diehl, Robert H.; Moore, Frank R.; Randall, Lori A.; Schreckengost, Timothy; Smolinsky, Jaclyn A.

    2018-01-01

    Despite using the aerosphere for many facets of their life, most flying animals (i.e., birds, bats, some insects) are still bound to terrestrial habitats for resting, feeding, and reproduction. Comprehensive broad-scale observations by weather surveillance radars of animals as they leave terrestrial habitats for migration or feeding flights can be used to map their terrestrial distributions either as point locations (e.g., communal roosts) or as continuous surface layers (e.g., animal densities in habitats across a landscape). We discuss some of the technical challenges to reducing measurement biases related to how radars sample the aerosphere and the flight behavior of animals. We highlight a recently developed methodological approach that precisely and quantitatively links the horizontal spatial structure of birds aloft to their terrestrial distributions and provides novel insights into avian ecology and conservation across broad landscapes. Specifically, we present case studies that (1) elucidate how migrating birds contend with crossing ecological barriers and extreme weather events, (2) identify important stopover areas and habitat use patterns of birds along their migration routes, and (3) assess waterfowl response to wetland habitat management and restoration. These studies aid our understanding of how anthropogenic modification of the terrestrial landscape (e.g., urbanization, habitat management), natural geographic features, and weather (e.g., hurricanes) can affect the terrestrial distributions of flying animals.

  8. COED Transactions, Vol. X, No. 9, September 1978. Use of the Analog/Hybrid Computer in Boundary Layer and Convection Studies.

    Science.gov (United States)

    Mitchell, Eugene E., Ed.

    In certain boundary layer or natural convection work, where a similarity transformation is valid, the equations can be reduced to a set of nonlinear ordinary differential equations. They are therefore well-suited to a fast solution on an analog/hybrid computer. This paper illustrates such usage of the analog/hybrid computer by a set of…

  9. Children's analogical reasoning about natural phenomena.

    Science.gov (United States)

    Pauen, S; Wilkening, F

    1997-10-01

    This report investigates children's analogical reasoning in a physics task, using an analogy generated by the children rather than by the experimenter. A total of 127 elementary school children took part in three related studies. Children learned to predict the behavior of a balance scale. Later, they were asked to solve a force interaction problem. Two versions of the balance scale training were devised: version A suggested an incorrect solution to the target problem (negative analogy), and version B suggested a correct solution to the target problem (positive analogy). In Study 1, 9- to 10-year-olds showed spontaneous transfer in both training conditions. In Study 2, 7-year-olds did not show any transfer in the positive analogy condition. Study 3 revealed that the lack of transfer in younger children was not due to a failure either to notice the analogy or to perform the mapping. Instead, 7-year-olds transferred only selected aspects of the correct solution. Copyright 1997 Academic Press.

  10. Inductive, Analogical, and Communicative Generalization

    Directory of Open Access Journals (Sweden)

    Adri Smaling

    2003-03-01

    Full Text Available Three forms of inductive generalization - statistical generalization, variation-based generalization and theory-carried generalization - are insufficient concerning case-to-case generalization, which is a form of analogical generalization. The quality of case-to-case generalization needs to be reinforced by setting up explicit analogical argumentation. To evaluate analogical argumentation six criteria are discussed. Good analogical reasoning is an indispensable support to forms of communicative generalization - receptive and responsive (participative generalization — as well as exemplary generalization.

  11. Novel acyclonucleoside analog bearing a 1,2,4-triazole–Schiff base: Synthesis, characterization and analytical studies using square wave-adsorptive stripping voltammetry and HPLC

    Directory of Open Access Journals (Sweden)

    Ali F. Alghamdi

    2017-09-01

    Full Text Available New acyclonucleoside analogs tethered by a 1,2,4-triazole scaffold were synthesized through the condensation of 4-amino-5-(2-phenyleth-1-yl-2,4-dihydro-3H-1,2,4-triazole-3-thione (2 with benzaldehyde followed by the alkylation of the resulting Schiff base (3with 2-bromoethanol, 3-chloropropanol and/or 3-chloropropan-1,2-diol. Voltammetric studies were carried out for the analysis of 1 × 10−6 mol L−1 of the newly synthesized acyclonucleoside analogs (4–6 using square wave-adsorptive stripping voltammetry (SW-AdSV. The sharp voltammetric peak and high reduction current were recorded using a Britton–Robinson B–R pH 10 buffer at Ep = −1250 mV on the hanging mercury drop surface (HMDE and Ag/AgCl reference electrode. Several experimental conditions were studied, such as the supporting electrolytes, the pH, and the accumulation time, as well as the potential, the scan rate, the frequency and the step potential for 4-benzylideneamino-5-(2-phenyleth-1-yl-3-[(2,3-dihydroxyprop-1-ylthio]-1,2,4-triazole (6. The analytical performance of the voltammetric technique was investigated through the analysis of the calibration curve, the detection limit, the recovery and the stability. The voltammetric analytical applications were evaluated by the recovery of compound (6 in the urine and plasma samples. The HPLC technique was also applied for the separation of compound (6 from interference using a C-18 (5 μm column with UV detection at 254 nm.

  12. Comparative evaluation of pressure generated on a simulated maxillary oral analog by impression materials in custom trays of different spacer designs: An in vitro study

    Directory of Open Access Journals (Sweden)

    Sakshi Chopra

    2016-01-01

    Full Text Available Introduction: Literature reveals that masticatory load on denture bearing tissues through complete dentures should be maximum on primary stress bearing areas and least on relief area in accordance with the histology of underlying tissues. A study to validate the existing beliefs was planned to compare the pressure on mucosa using selective pressure technique and minimal pressure technique, with the incorporation of two different impression materials utilizing the pressure sensors during secondary impression procedure. Materials and Methods: The study was performed using a maxillary analog. Three pressure sensors were imbedded in the oral analog, one in the mid palatine area and the other two in the right and left ridge crest. Custom trays of two different configurations were fabricated. The two impression materials tested were light body and zinc oxide eugenol. A total of 40 impressions were made. A constant weight of 1 kg was placed, and the pressure was recorded as initial and end pressures. Results: A significant difference in the pressure produced using different impression materials was found (P < 0.001. Light body vinyl polysiloxane produced significantly lesser pressure than zinc oxide eugenol impression materials. The presence of relief did affect the magnitude of pressure at various locations. Conclusion: All impression materials produced pressure during maxillary edentulous impression making. Tray modification is an important factor in changing the amount of pressure produced. The impression materials used also had a significant role to play on the pressures acting on the tissues during impression procedure. Clinical Implication: Light body VPS impression material may be recommended to achieve minimal pressure on the denture bearing tissues in both selective as well as minimal pressure techniques.

  13. ON THE EFFECT OF GIANT PLANETS ON THE SCATTERING OF PARENT BODIES OF IRON METEORITE FROM THE TERRESTRIAL PLANET REGION INTO THE ASTEROID BELT: A CONCEPT STUDY

    International Nuclear Information System (INIS)

    Haghighipour, Nader; Scott, Edward R. D.

    2012-01-01

    In their model for the origin of the parent bodies of iron meteorites, Bottke et al. proposed differentiated planetesimals, formed in 1-2 AU during the first 1.5 Myr, as the parent bodies, and suggested that these objects and their fragments were scattered into the asteroid belt as a result of interactions with planetary embryos. Although viable, this model does not include the effect of a giant planet that might have existed or been growing in the outer regions. We present the results of a concept study where we have examined the effect of a planetary body in the orbit of Jupiter on the early scattering of planetesimals from the terrestrial region into the asteroid belt. We integrated the orbits of a large battery of planetesimals in a disk of planetary embryos and studied their evolutions for different values of the mass of the planet. Results indicate that when the mass of the planet is smaller than 10 M ⊕ , its effects on the interactions among planetesimals and planetary embryos are negligible. However, when the planet mass is between 10 and 50 M ⊕ , simulations point to a transitional regime with ∼50 M ⊕ being the value for which the perturbing effect of the planet can no longer be ignored. Simulations also show that further increase of the mass of the planet strongly reduces the efficiency of the scattering of planetesimals from the terrestrial planet region into the asteroid belt. We present the results of our simulations and discuss their possible implications for the time of giant planet formation.

  14. Discrete Calculus by Analogy

    CERN Document Server

    Izadi, F A; Bagirov, G

    2009-01-01

    With its origins stretching back several centuries, discrete calculus is now an increasingly central methodology for many problems related to discrete systems and algorithms. The topics covered here usually arise in many branches of science and technology, especially in discrete mathematics, numerical analysis, statistics and probability theory as well as in electrical engineering, but our viewpoint here is that these topics belong to a much more general realm of mathematics; namely calculus and differential equations because of the remarkable analogy of the subject to this branch of mathemati

  15. ESD analog circuits and design

    CERN Document Server

    Voldman, Steven H

    2014-01-01

    A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design.  It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres

  16. Working group 4: Terrestrial

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    A working group at a Canada/USA symposium on climate change and the Arctic identified major concerns and issues related to terrestrial resources. The group examined the need for, and the means of, involving resource managers and users at local and territorial levels in the process of identifying and examining the impacts and consequences of climatic change. Climatic change will be important to the Arctic because of the magnitude of the change projected for northern latitudes; the apparent sensitivity of its terrestrial ecosystems, natural resources, and human support systems; and the dependence of the social, cultural, and economic welfare of Arctic communities, businesses, and industries on the health and quality of their environment. Impacts of climatic change on the physical, biological, and associated socio-economic environment are outlined. Gaps in knowledge needed to quantify these impacts are listed along with their relationships with resource management. Finally, potential actions for response and adaptation are presented

  17. Terrestrial plant methane production

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Bruhn, Dan; Møller, Ian M.

    We evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants. We conclude that the phenomenon is true. Four stimulating factors have been observed to induce aerobic plant CH4 production, i.e. cutting injuries, increasing temperature...... the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH4 precursors in plant material....

  18. Use of insulin and insulin analogs and risk of cancer - systematic review and meta-analysis of observational studies

    DEFF Research Database (Denmark)

    Karlstad, Oystein; Linde, Jakob Starup; Vestergaard, Peter

    2013-01-01

    -control studies examining risk of cancer associated with insulin use in patients with diabetes. DATA SOURCES: Systematic literature search in 5 databases: PubMed, Embase, Web of Science, Scopus and Cochrane Library. STUDY ELIGIBILITY CRITERIA (PICOS): POPULATION: diabetes patients. EXPOSURE: Users of any...

  19. Possible climates on terrestrial exoplanets.

    Science.gov (United States)

    Forget, F; Leconte, J

    2014-04-28

    What kind of environment may exist on terrestrial planets around other stars? In spite of the lack of direct observations, it may not be premature to speculate on exoplanetary climates, for instance, to optimize future telescopic observations or to assess the probability of habitable worlds. To begin with, climate primarily depends on (i) the atmospheric composition and the volatile inventory; (ii) the incident stellar flux; and (iii) the tidal evolution of the planetary spin, which can notably lock a planet with a permanent night side. The atmospheric composition and mass depends on complex processes, which are difficult to model: origins of volatiles, atmospheric escape, geochemistry, photochemistry, etc. We discuss physical constraints, which can help us to speculate on the possible type of atmosphere, depending on the planet size, its final distance for its star and the star type. Assuming that the atmosphere is known, the possible climates can be explored using global climate models analogous to the ones developed to simulate the Earth as well as the other telluric atmospheres in the solar system. Our experience with Mars, Titan and Venus suggests that realistic climate simulators can be developed by combining components, such as a 'dynamical core', a radiative transfer solver, a parametrization of subgrid-scale turbulence and convection, a thermal ground model and a volatile phase change code. On this basis, we can aspire to build reliable climate predictors for exoplanets. However, whatever the accuracy of the models, predicting the actual climate regime on a specific planet will remain challenging because climate systems are affected by strong positive feedbacks. They can drive planets with very similar forcing and volatile inventory to completely different states. For instance, the coupling among temperature, volatile phase changes and radiative properties results in instabilities, such as runaway glaciations and runaway greenhouse effect.

  20. Use of Insulin and Insulin Analogs and Risk of Cancer — Systematic Review and Meta-Analysis of Observational Studies

    Science.gov (United States)

    Karlstad, Øystein; Starup-Linde, Jacob; Vestergaard, Peter; Hjellvik, Vidar; T. Bazelier, Marloes; K. Schmidt, Marjanka; Andersen, Morten; Auvinen, Anssi; Haukka, Jari; Furu, Kari; de Vries, Frank; L. de Bruin, Marie

    2014-01-01

    Background: An association of insulin use and risk of cancer has been reported but evidence is conflicting and methodological issues have been identified. Objective: To summarize results regarding insulin use and cancer risk by a systematic review and meta-analysis of cohort and case-control studies examining risk of cancer associated with insulin use in patients with diabetes. Data Sources: Systematic literature search in 5 databases: PubMed, Embase, Web of Science, Scopus and Cochrane Library. Study Eligibility Criteria (PICOS): Population: diabetes patients. Exposure: Users of any exogenous insulin. Comparison: Diabetes patients with or without use of antidiabetic drugs. Outcome: Any incident cancer. Study Design: Cohort and case-control studies. Results: 42 eligible studies examined risk of any cancer and 27 site-specific cancers. Results of individual studies were heterogeneous. Meta-analyses were significant for: Insulin vs No Insulin: Increased risk for pancreas, liver, kidney, stomach and respiratory cancer, decreased risk for prostate cancer. Insulin vs Non-Insulin Antidiabetics: Increased risk for any, pancreatic and colorectal cancer. Glargine vs Non-Glargine Insulin: Increased risk for breast cancer, decreased risk for colon cancer. Limitations: Few studies available for most cancer sites and exposure contrasts, and few assess effect of dose and duration of exposure. Methodological issues in several studies. Availability of confounders. Conclusions: Insulin use was associated with risk of cancer at several sites. Cautious interpretation of results is warranted as methodological issues and limitations in several of the included studies have been identified. Choice of study design may have a profound effect on estimated cancer risk. PMID:24215311

  1. Beach-ridge sedimentology as an archive of terrestrial climate change: Insights from a geochemical and stratigraphic study of the Tijucas Strandplain, southern Brazil

    Science.gov (United States)

    Krask, J. L.; Hein, C. J.; Galy, V.; FitzGerald, D.; Henrique de Fontoura Klein, A.

    2017-12-01

    Whereas millennial-scale variations in climate forcing drives changes in terrestrial processes, which are in turn directly linked to fluvial sediment loads (e.g., weathering and erosion), the impact of decadal- to centennial- scale climate fluctuations on downstream coastal sedimentation patterns and landscape evolution remains unclear. Specifically, the connection between long-term (decades or more) precipitation seasonality and sediment export from river systems has not been established. This study examines the manner in which sub-millennial-scale fluctuations in precipitation over river catchments may be recorded in coastal progradational sedimentary archives. The 5-km wide Tijucas Strandplain (southern Brazil) formed over the last 5800 years through the rapid reworking of sediment discharged from the Tijucas River in a regime of falling sea level. In an overall regime shift from sand- to mud- dominance (linked to a long-term reduction in wave energy caused by bay shoaling) are nearly 70 distinct transitions between shore-parallel sand- and mud- dominated facies. Bulk organic carbon and terrestrial plant-wax fatty acid stable hydrogen (δD) and carbon (δ13C) isotopic measurements from sediments from select sandy and muddy ridges across the plain reveal that these two sedimentological regimes are geochemically distinct. Specifically, waxes from sediments deposited during periods of sandy progradation had δD values, on average, >10 ‰ higher than those from mud-dominated periods, indicating that these sedimentary units reflect different hydroclimatic conditions within the river drainage basin at the time of deposition. Comparison of plant wax isotopic signatures of river, bay, and beach sediments during the current period of mud-dominated progradation reveals a close correlation with earlier periods of mud deposition within the Tijucas Strandplain. Thus, decadal- to centennial- scale sedimentologic transitions within the plain are interpreted to reflect climate

  2. Estimating the terrestrial N processes in subtropical mountainous forestry catchment through INCA-N: A case study in FuShan catchment, Taiwan

    Science.gov (United States)

    Lu, Meng-Chang; Huang, -Chuan, Jr.; Chang, Chung-Te; Shih, Yu-Ting; Lin, Teng-Chiu

    2016-04-01

    The riverine DIN is a crucial indicator for eutrophication in river network. The riverine DIN export in Taiwan is featured by the extremely high yield, ~3800 kg-N km-2yr-1, nearly 20-fold than the global average, showing the interesting terrestrial N process yet rarely documented. In this study we collected the DIN samples in rainwater, soil water, and stream water in a mountainous forest watershed, FuShan experimental forest watershed 1 (WS1) which is a natural broadleaf forest without human activities. Based on the intensive observations, we applied the INCA-N to simulate the riverine DIN response and thus estimate the terrestrial N processes in a global synthesis. The result showed that both discharge and DIN yield were simulated well with the average Nash-Sutcliffe efficiency coefficient of 0.83 and 0.76 , respectively. Among all N processes, N uptake, mineralization, nitrification, denitrfication, and immobilization are significantly positive correlated with soil moisture (R2>0.99), which indicates that soil moisture greatly influences N cycle processes. The average rate of mineralization and nitrification in wet years are consistent with documented values, whereas the rates in dry years are lower than the observations. Despite the high nitrification rate, the secondary forest may uptake abundant N indicating the plant uptake, which responds for removing considerable nitrate, is a controlling factor in forest ecosystem. Our simulated denitrification rate falls between the documented rates of temperate forest and agricultural area, and that may be affected by the high N-deposition in Taiwan. Simulated in-stream denitrification rate is less than 10% of the rate in soil, and is a little lower than that in temperate forest. This preliminary simulation provides an insightful guide to establish the monitoring programme and improve the understanding of N cycle in subtropical.

  3. Albert Einstein, Analogizer Extraordinaire

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    Where does deep insight in physics come from? It is tempting to think that it comes from the purest and most precise of reasoning, following ironclad laws of thought that compel the clear mind completely rigidly. And yet the truth is quite otherwise. One finds, when one looks closely at any major discovery, that the greatest of physicists are, in some sense, the most crazily daring and irrational of all physicists. Albert Einstein exemplifies this thesis in spades. In this talk I will describe the key role, throughout Albert Einstein's fabulously creative life, played by wild guesses made by analogy lacking any basis whatsoever in pure reasoning. In particular, in this year of 2007, the centenary of 1907, I will describe how over the course of two years (1905 through 1907) of pondering, Einstein slowly came, via analogy, to understand the full, radical consequences of the equation that he had first discovered and published in 1905, arguably the most famous equation of all time: E = mc2.

  4. Microplastics in the Terrestrial Ecosystem: Implications for Lumbricus terrestris (Oligochaeta, Lumbricidae).

    Science.gov (United States)

    Huerta Lwanga, Esperanza; Gertsen, Hennie; Gooren, Harm; Peters, Piet; Salánki, Tamás; van der Ploeg, Martine; Besseling, Ellen; Koelmans, Albert A; Geissen, Violette

    2016-03-01

    Plastic debris is widespread in the environment, but information on the effects of microplastics on terrestrial fauna is completely lacking. Here, we studied the survival and fitness of the earthworm Lumbricus terrestris (Oligochaeta, Lumbricidae) exposed to microplastics (Polyethylene, digestion of ingested organic matter, microplastic was concentrated in cast, especially at the lowest dose (i.e., 7% in litter) because that dose had the highest proportion of digestible organic matter. Whereas 50 percent of the microplastics had a size of earthworms. These concentration-transport and size-selection mechanisms may have important implications for fate and risk of microplastic in terrestrial ecosystems.

  5. Individual differences influence two-digit number processing, but not their analog magnitude processing: a large-scale online study.

    Science.gov (United States)

    Huber, Stefan; Nuerk, Hans-Christoph; Reips, Ulf-Dietrich; Soltanlou, Mojtaba

    2017-12-23

    Symbolic magnitude comparison is one of the most well-studied cognitive processes in research on numerical cognition. However, while the cognitive mechanisms of symbolic magnitude processing have been intensively studied, previous studies have paid less attention to individual differences influencing symbolic magnitude comparison. Employing a two-digit number comparison task in an online setting, we replicated previous effects, including the distance effect, the unit-decade compatibility effect, and the effect of cognitive control on the adaptation to filler items, in a large-scale study in 452 adults. Additionally, we observed that the most influential individual differences were participants' first language, time spent playing computer games and gender, followed by reported alcohol consumption, age and mathematical ability. Participants who used a first language with a left-to-right reading/writing direction were faster than those who read and wrote in the right-to-left direction. Reported playing time for computer games was correlated with faster reaction times. Female participants showed slower reaction times and a larger unit-decade compatibility effect than male participants. Participants who reported never consuming alcohol showed overall slower response times than others. Older participants were slower, but more accurate. Finally, higher grades in mathematics were associated with faster reaction times. We conclude that typical experiments on numerical cognition that employ a keyboard as an input device can also be run in an online setting. Moreover, while individual differences have no influence on domain-specific magnitude processing-apart from age, which increases the decade distance effect-they generally influence performance on a two-digit number comparison task.

  6. Working hours, sleep, salivary cortisol, fatigue and neuro-behavior during Mars analog mission: five crews study.

    Science.gov (United States)

    Rai, Balwant; Foing, Bernard H; Kaur, Jasdeep

    2012-05-16

    The buoyancy of humans in exploring extreme space environments has been established during missions to the moon. Long duration missions like mission to Mars however, requires humans to adapt to systemic and complex environments beyond the human body's capacity. Astronauts will encounter both physiological and psychological extremes during this trip. Very few studies are conducted on effect of long duration work and sleepiness on cognitive performance. So, this study was planned to find out effects of leadership responsibility, sleepiness and long duration working hours on cognitive performance. The 30 members (leadership: normal; 10:20) were selected from MDRS crews (Mars Desert Research Station, USA). Neurobehavioral test performance, self-ratings of fatigue and sleepiness, and salivary cortisol levels were evaluated during first day, mid and end day of mission. The leadership group did not show any signs of reduced test performance, even in elevated fatigue and sleepiness. The leadership group had faster reaction times on end of mission as compared to first and after 7 day of mission. Salivary cortisol levels were significantly higher in leadership group as compared to normal group. The results suggest that long duration work and sleepiness does not affect the cognitive performance of crew member. Further study is required while taking into account all factors and large sample size to prove this fact. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  7. A bilateral frontoparietal network underlies visuospatial analogical reasoning.

    Science.gov (United States)

    Watson, Christine E; Chatterjee, Anjan

    2012-02-01

    Our ability to reason by analogy facilitates problem solving and allows us to communicate ideas efficiently. In this study, we examined the neural correlates of analogical reasoning and, more specifically, the contribution of rostrolateral prefrontal cortex (RLPFC) to reasoning. This area of the brain has been hypothesized to integrate relational information, as in analogy, or the outcomes of subgoals, as in multi-tasking and complex problem solving. Using fMRI, we compared visuospatial analogical reasoning to a control task that was as complex and difficult as the analogies and required the coordination of subgoals but not the integration of relations. We found that analogical reasoning more strongly activated bilateral RLPFC, suggesting that anterior prefrontal cortex is preferentially recruited by the integration of relational knowledge. Consistent with the need for inhibition during analogy, bilateral, and particularly right, inferior frontal gyri were also more active during analogy. Finally, greater activity in bilateral inferior parietal cortex during the analogy task is consistent with recent evidence for the neural basis of spatial relation knowledge. Together, these findings indicate that a network of frontoparietal areas underlies analogical reasoning; we also suggest that hemispheric differences may emerge depending on the visuospatial or verbal/semantic nature of the analogies. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Elucidating the neurotoxic effects of MDMA and its analogs.

    Science.gov (United States)

    Karuppagounder, Senthilkumar S; Bhattacharya, Dwipayan; Ahuja, Manuj; Suppiramaniam, Vishnu; Deruiter, Jack; Clark, Randall; Dhanasekaran, Muralikrishnan

    2014-04-17

    There is a rapid increase in the use of methylenedioxymethamphetamine (MDMA) and its structural congeners/analogs globally. MDMA and MDMA-analogs have been synthesized illegally in furtive dwellings and are abused due to its addictive potential. Furthermore, MDMA and MDMA-analogs have shown to have induced several adverse effects. Hence, understanding the mechanisms mediating this neurotoxic insult of MDMA-analogs is of immense importance for the public health in the world. We synthesized and investigated the neurotoxic effects of MDMA and its analogs [4-methylenedioxyamphetamine (MDA), 2, 6-methylenedioxyamphetamine (MDMA), and N-ethyl-3, 4-methylenedioxyamphetamine (MDEA)]. The stimulatory or the dopaminergic agonist effects of MDMA and MDMA-analogs were elucidated using the established 6-hydroxydopamine lesioned animal model. Additionally, we also investigated the neurotoxic mechanisms of MDMA and MDMA-analogs on mitochondrial complex-I activity and reactive oxygen species generation. MDMA and MDMA-analogs exhibited stimulatory activity as compared to amphetamines and also induced several behavioral changes in the rodents. MDMA and MDMA-analogs enhanced the reactive oxygen generation and inhibited mitochondrial complex-I activity which can lead to neurodegeneration. Hence the mechanism of neurotoxicity, MDMA and MDMA-analogs can enhance the release of monoamines, alter the monoaminergic neurotransmission, and augment oxidative stress and mitochondrial abnormalities leading to neurotoxicity. Thus, our study will help in developing effective pharmacological and therapeutic approaches for the treatment of MDMA and MDMA-analog abuse. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Study of external exposure doses received by Cuban population due to terrestrial component of the environmental radiation sources; Estudio de las dosis por exposicion externa que recibe la poblacion cubana debidas a la componente terrestre de la radiacion ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Zerquera, Juan Tomas; Prendes Alonso, Miguel [Centro de Proteccion y Higiene de las Radiaciones, La Habana (Cuba); Brigido Flores, Osvaldo [Laboratorio de Vigilancia Radiologica Ambiental de Camaguey (Cuba); Hernandez Perez, Alberto [Laboratorio de Vigilancia Radiologica Ambiental de Oriente, Holguin (Cuba)

    2001-07-01

    The work presents the results of the study carried out to evaluate the doses that the Cuban population receives for the external exposition to the terrestrial component of the environmental sources of radiation. Starting from the carried out measurements it was possible to estimate the doses effective representative annual stockings that the Cuban population receives for external exposition to the terrestrial radiation, considering the permanency in indoors and outdoors. The dose received due to this component was 180{+-}14 mSv/year. These values are in the range of those reported internationally. (author)

  10. Prospects of 'Topologically unquenched QCD' from a study of the analogous importance sampling method in the massive Schwinger model

    International Nuclear Information System (INIS)

    Duerr, S.

    2000-01-01

    I give a quick summary of my proposal for simulating an improvement on quenched QCD with dynamical fermions which interact with the gluon configuration only via the topological index of the latter. It amounts to include only the topological part of the functional determinant into the measure, thereby absorbing a correction factor into the observable. I discuss the prospects of this concept from a study in the massive N f- flavour Schwinger model, where the correction factor is indeed found to be of order 0(1)

  11. Feedback in analog circuits

    CERN Document Server

    Ochoa, Agustin

    2016-01-01

    This book describes a consistent and direct methodology to the analysis and design of analog circuits with particular application to circuits containing feedback. The analysis and design of circuits containing feedback is generally presented by either following a series of examples where each circuit is simplified through the use of insight or experience (someone else’s), or a complete nodal-matrix analysis generating lots of algebra. Neither of these approaches leads to gaining insight into the design process easily. The author develops a systematic approach to circuit analysis, the Driving Point Impedance and Signal Flow Graphs (DPI/SFG) method that does not require a-priori insight to the circuit being considered and results in factored analysis supporting the design function. This approach enables designers to account fully for loading and the bi-directional nature of elements both in the feedback path and in the amplifier itself, properties many times assumed negligible and ignored. Feedback circuits a...

  12. A natural analogy of high-level radioactive waste disposal. A case study of the groundwater from a uranium deposit

    International Nuclear Information System (INIS)

    Li Xinchun; Zhang Zhanshi; Ouyang Hegen

    2009-01-01

    Radionuclide migration is one of the key effects of high-level radioactive waste disposal. The groundwater is considered the primary means of radionuclide migration. Uranium and rare earth element(REE) in groundwater from a uranium deposit were used as a chemical analogue to study the migration of radionuclides. The results show that REE and its chemical analogue might migrate under the uranium deposit condition, but uranium and its analogue do not migrate obviously. According to the results, we might infer that after the groundwater penetrates into the HLW repository, REE and its analogue might migrate with the groundwater; but there is no obvious migration of uranium and its chemical analogue,which might increase our confidence to built a safe HLW repository. (authors)

  13. Comparative thermal and thermodynamic study of DNA chemically modified with antitumor drug cisplatin and its inactive analog transplatin.

    Science.gov (United States)

    Lando, Dmitri Y; Chang, Chun-Ling; Fridman, Alexander S; Grigoryan, Inessa E; Galyuk, Elena N; Hsueh, Ya-Wei; Hu, Chin-Kun

    2014-08-01

    Antitumor activity of cisplatin is exerted by covalent binding to DNA. For comparison, studies of cisplatin-DNA complexes often employ the very similar but inactive transplatin. In this work, thermal and thermodynamic properties of DNA complexes with these compounds were studied using differential scanning calorimetry (DSC) and computer modeling. DSC demonstrates that cisplatin decreases thermal stability (melting temperature, Tm) of long DNA, and transplatin increases it. At the same time, both compounds decrease the enthalpy and entropy of the helix-coil transition, and the impact of transplatin is much higher. From Pt/nucleotide molar ratio rb=0.001, both compounds destroy the fine structure of DSC profile and increase the temperature melting range (ΔT). For cisplatin and transplatin, the dependences δTm vs rb differ in sign, while δΔT vs rb are positive for both compounds. The change in the parameter δΔT vs rb demonstrates the GC specificity in the location of DNA distortions. Our experimental results and calculations show that 1) in contrast to [Pt(dien)Cl]Cl, monofunctional adducts formed by transplatin decrease the thermal stability of long DNA at [Na(+)]>30mM; 2) interstrand crosslinks of cisplatin and transplatin only slightly increase Tm; 3) the difference in thermal stability of DNA complexes with cisplatin vs DNA complexes with transplatin mainly arises from the different thermodynamic properties of their intrastrand crosslinks. This type of crosslink appears to be responsible for the antitumor activity of cisplatin. At any [Na(+)] from interval 10-210mM, cisplatin and transplatin intrastrand crosslinks give rise to destabilization and stabilization, respectively. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. The Moon as a recorder of organic evolution in the early solar system: a lunar regolith analog study.

    Science.gov (United States)

    Matthewman, Richard; Court, Richard W; Crawford, Ian A; Jones, Adrian P; Joy, Katherine H; Sephton, Mark A

    2015-02-01

    The organic record of Earth older than ∼3.8 Ga has been effectively erased. Some insight is provided to us by meteorites as well as remote and direct observations of asteroids and comets left over from the formation of the Solar System. These primitive objects provide a record of early chemical evolution and a sample of material that has been delivered to Earth's surface throughout the past 4.5 billion years. Yet an effective chronicle of organic evolution on all Solar System objects, including that on planetary surfaces, is more difficult to find. Fortunately, early Earth would not have been the only recipient of organic matter-containing objects in the early Solar System. For example, a recently proposed model suggests the possibility that volatiles, including organic material, remain archived in buried paleoregolith deposits intercalated with lava flows on the Moon. Where asteroids and comets allow the study of processes before planet formation, the lunar record could extend that chronicle to early biological evolution on the planets. In this study, we use selected free and polymeric organic materials to assess the hypothesis that organic matter can survive the effects of heating in the lunar regolith by overlying lava flows. Results indicate that the presence of lunar regolith simulant appears to promote polymerization and, therefore, preservation of organic matter. Once polymerized, the mineral-hosted newly formed organic network is relatively protected from further thermal degradation. Our findings reveal the thermal conditions under which preservation of organic matter on the Moon is viable.

  15. Study of nuclear reactions and analog isobar states in the system He8 + p for low energy with the help of MAYA active target

    International Nuclear Information System (INIS)

    Demonchy, Ch.E.

    2003-12-01

    With the resent improvements in the field of exotics beams, and specially with the SPIRAL facility at GANIL, we were able to study He 9 shell inversion already known for Be 11 and Li 10 , which are two members of the N=7 family. A new detector was developed and also the software tools for the data analysis. This detector is at the same time the target (active-target) and is called MAYA. The He 9 was studied by determining the properties of its isobaric analogue states in Li 9 . The characteristics of the IAS (isomeric analog state) states were determined by an analysis of the resonances in the elastic scattering cross section for He 8 + p from 2 up to 3.9 MeV/n. A study of (p,d) and (p,t) reactions was done too, in this domain of energy. By comparing the experimental results with calculations, an assignation of spin and parity for two states in He 9 was possible. (author)

  16. Beginning analog electronics through projects

    CERN Document Server

    Singmin, Andrew

    2001-01-01

    Analog electronics is the simplest way to start a fun, informative, learning program. Beginning Analog Electronics Through Projects, Second Edition was written with the needs of beginning hobbyists and students in mind. This revision of Andrew Singmin's popular Beginning Electronics Through Projects provides practical exercises, building techniques, and ideas for useful electronics projects. Additionally, it features new material on analog and digital electronics, and new projects for troubleshooting test equipment.Published in the tradition of Beginning Electronics Through Projects an

  17. Comparative Climatology of Terrestrial Planets

    Science.gov (United States)

    Mackwell, Stephen J.; Simon-Miller, Amy A.; Harder, Jerald W.; Bullock, Mark A.

    Public awareness of climate change on Earth is currently very high, promoting significant interest in atmospheric processes. We are fortunate to live in an era where it is possible to study the climates of many planets, including our own, using spacecraft and groundbased observations as well as advanced computational power that allows detailed modeling. Planetary atmospheric dynamics and structure are all governed by the same basic physics. Thus differences in the input variables (such as composition, internal structure, and solar radiation) among the known planets provide a broad suite of natural laboratory settings for gaining new understanding of these physical processes and their outcomes. Diverse planetary settings provide insightful comparisons to atmospheric processes and feedbacks on Earth, allowing a greater understanding of the driving forces and external influences on our own planetary climate. They also inform us in our search for habitable environments on planets orbiting distant stars, a topic that was a focus of Exoplanets, the preceding book in the University of Arizona Press Space Sciences Series. Quite naturally, and perhaps inevitably, our fascination with climate is largely driven toward investigating the interplay between the early development of life and the presence of a suitable planetary climate. Our understanding of how habitable planets come to be begins with the worlds closest to home. Venus, Earth, and Mars differ only modestly in their mass and distance from the Sun, yet their current climates could scarcely be more divergent. Our purpose for this book is to set forth the foundations for this emerging science and to bring to the forefront our current understanding of atmospheric formation and climate evolution. Although there is significant comparison to be made to atmospheric processes on nonterrestrial planets in our solar system — the gas and ice giants — here we focus on the terrestrial planets, leaving even broader comparisons

  18. Arctic Terrestrial Biodiversity Monitoring Plan

    DEFF Research Database (Denmark)

    Christensen, Tom; Payne, J.; Doyle, M.

    The Conservation of Arctic Flora and Fauna (CAFF), the biodiversity working group of the Arctic Council, established the Circumpolar Biodiversity Monitoring Program (CBMP) to address the need for coordinated and standardized monitoring of Arctic environments. The CBMP includes an international...... on developing and implementing long-term plans for monitoring the integrity of Arctic biomes: terrestrial, marine, freshwater, and coastal (under development) environments. The CBMP Terrestrial Expert Monitoring Group (CBMP-TEMG) has developed the Arctic Terrestrial Biodiversity Monitoring Plan (CBMP......-Terrestrial Plan/the Plan) as the framework for coordinated, long-term Arctic terrestrial biodiversity monitoring. The goal of the CBMP-Terrestrial Plan is to improve the collective ability of Arctic traditional knowledge (TK) holders, northern communities, and scientists to detect, understand and report on long...

  19. Children's Development of Analogical Reasoning: Insights from Scene Analogy Problems

    Science.gov (United States)

    Richland, Lindsey E.; Morrison, Robert G.; Holyoak, Keith J.

    2006-01-01

    We explored how relational complexity and featural distraction, as varied in scene analogy problems, affect children's analogical reasoning performance. Results with 3- and 4-year-olds, 6- and 7-year-olds, 9- to 11-year-olds, and 13- and 14-year-olds indicate that when children can identify the critical structural relations in a scene analogy…

  20. Dietary characterization of terrestrial mammals.

    Science.gov (United States)

    Pineda-Munoz, Silvia; Alroy, John

    2014-08-22

    Understanding the feeding behaviour of the species that make up any ecosystem is essential for designing further research. Mammals have been studied intensively, but the criteria used for classifying their diets are far from being standardized. We built a database summarizing the dietary preferences of terrestrial mammals using published data regarding their stomach contents. We performed multivariate analyses in order to set up a standardized classification scheme. Ideally, food consumption percentages should be used instead of qualitative classifications. However, when highly detailed information is not available we propose classifying animals based on their main feeding resources. They should be classified as generalists when none of the feeding resources constitute over 50% of the diet. The term 'omnivore' should be avoided because it does not communicate all the complexity inherent to food choice. Moreover, the so-called omnivore diets actually involve several distinctive adaptations. Our dataset shows that terrestrial mammals are generally highly specialized and that some degree of food mixing may even be required for most species.

  1. Terrestrial Zone Exoplanets and Life

    Science.gov (United States)

    Matthews, Brenda

    2018-01-01

    One of the most exciting results from ALMA has been the detection of significant substructure within protoplanetary disks that can be linked to planet formation processes. For the first time, we are able to observe the process of assembly of material into larger bodies within such disks. It is not possible, however, for ALMA to probe the growth of planets in protoplanetary disks at small radii, i.e., in the terrestrial zone, where we expect rocky terrestrial planets to form. In this regime, the optical depths prohibit observation at the high frequencies observed by ALMA. To probe the effects of planet building processes and detect telltale gaps and signatures of planetary mass bodies at such small separations from the parent star, we require a facility of superior resolution and sensitivity at lower frequencies. The ngVLA is just such a facility. We will present the fundamental science that will be enabled by the ngVLA in protoplanetary disk structure and the formation of planets. In addition, we will discuss the potential for an ngVLA facility to detect the molecules that are the building blocks of life, reaching limits well beyond those reachable with the current generation of telescopes, and also to determine whether such planets will be habitable based on studies of the impact of stars on their nearest planetary neighbours.

  2. Studies of fracture network geometry of reservoir outcrop analogues from terrestrial lidar data: attempts to quantify spatial variations of fracture characteristics

    Science.gov (United States)

    Vsemirnova, E. A.; Jones, R. R.; McCaffrey, K. J. W.

    2012-04-01

    We describe studies analysing terrestrial lidar datasets of fracture systems from a range of reservoir analogues in clastic and carbonate lithologies that represent geological analogues of offshore hydrocarbon reservoirs for the UK continental shelf. As fracture networks (observed here from centimetre to kilometre scale) can significantly affect the permeability of a fractured reservoir, the definition of fracture network geometry at various scales has become an important goal of structural analysis. The main aim of the study has been to extend the investigation of fracture networks in order to quantify spatial variations in fracture parameters in a variety of lithologies. The datasets were pre-processed using RiSCAN PRO software, and then re-sampled and filtered to derive characteristics which are traditionally measured from outcrops, including size distributions, fracture spacing and clustering statistics. This type of analysis can significantly reduce the uncertainty associated with some field fracture network measurements. The digitised fracture networks datasets are then used to investigate various aspects of spatial heterogeneity. A series of fracture maps (joints and faults) were generated at different scales, and fracture trends were studied to test scale dependency of fracture orientations. Multiscale trend analysis was then applied to describe the trend structure of the fracture networks.

  3. Pilot Study on the Effect of Botanical Medicine (Tribulus terrestris) on Serum Testosterone Level and Erectile Function in Aging Males With Partial Androgen Deficiency (PADAM).

    Science.gov (United States)

    Roaiah, Mohamed Farid; El Khayat, Yasser Ibrahim; GamalEl Din, Sameh Fayek; Abd El Salam, Mohamed Ahmed

    2016-05-18

    This study was conducted on 30 consecutive male patients presenting to Kasr-Al Ainy Andrology outpatient clinic complaining of manifestations of partial androgen deficiency in aging males (PADAM). In this study (750 mg/day) of Tribulus terrestris in 3 divided doses, each of 250 mg, as an endogenous testosterone enhancer had been tried for a duration of 3 months and the evaluation of its effect had been monitored for each patient concerning its effect on serum testosterone (total and free) and luteinizing hormone (LH), as well as its impact on erectile function, which was evaluated by the International Index of Erectile Function-5 (IIEF-5) questionnaire for those patients. Results showed a statistically significant difference in the level of testosterone (total and free) and IIEF-5, but no statistically significant difference in the level of LH before and after treatment. Also, the study showed statistically significant correlation between testosterone (total and free) and IIEF-5, but no statistically significant correlation between the level of LH and the IIEF-5 before and after treatment.

  4. Concept and Practice of Teaching Technical University Students to Modern Technologies of 3d Data Acquisition and Processing: a Case Study of Close-Range Photogrammetry and Terrestrial Laser Scanning

    Science.gov (United States)

    Kravchenko, Iulia; Luhmann, Thomas; Shults, Roman

    2016-06-01

    For the preparation of modern specialists in the acquisition and processing of three-dimensional data, a broad and detailed study of related modern methods and technologies is necessary. One of the most progressive and effective methods of acquisition and analyzing spatial data is terrestrial laser scanning. The study of methods and technologies for terrestrial laser scanning is of great importance not only for GIS specialists, but also for surveying engineers who make decisions in traditional engineering tasks (monitoring, executive surveys, etc.). The understanding and formation of the right approach in preparing new professionals need to develop a modern and variable educational program. This educational program must provide effective practical and laboratory work and the student's coursework. The resulting knowledge of the study should form the basis for practical or research of young engineers. In 2014, the Institute of Applied Sciences (Jade University Oldenburg, Germany) and Kyiv National University of Construction and Architecture (Kiev, Ukraine) had launched a joint educational project for the introduction of terrestrial laser scanning technology for collection and processing of spatial data. As a result of this project practical recommendations have been developed for the organization of educational processes in the use of terrestrial laser scanning. An advanced project-oriented educational program was developed which is presented in this paper. In order to demonstrate the effectiveness of the program a 3D model of the big and complex main campus of Kyiv National University of Construction and Architecture has been generated.

  5. Application of 4D-QSAR Studies to a Series of Raloxifene Analogs and Design of Potential Selective Estrogen Receptor Modulators

    Directory of Open Access Journals (Sweden)

    Carlos Rangel Rodrigues

    2012-06-01

    Full Text Available Four-dimensional quantitative structure-activity relationship (4D-QSAR analysis was applied on a series of 54 2-arylbenzothiophene derivatives, synthesized by Grese and coworkers, based on raloxifene (an estrogen receptor-alpha antagonist, and evaluated as ERa ligands and as inhibitors of estrogen-stimulated proliferation of MCF-7 breast cancer cells. The conformations of each analogue, sampled from a molecular dynamics simulation, were placed in a grid cell lattice according to three trial alignments, considering two grid cell sizes (1.0 and 2.0 Å. The QSAR equations, generated by a combined scheme of genetic algorithms (GA and partial least squares (PLS regression, were evaluated by “leave-one-out” cross-validation, using a training set of 41 compounds. External validation was performed using a test set of 13 compounds. The obtained 4D-QSAR models are in agreement with the proposed mechanism of action for raloxifene. This study allowed a quantitative prediction of compounds’ potency and supported the design of new raloxifene analogs.

  6. In Silico Exploration of 1,7-Diazacarbazole Analogs as Checkpoint Kinase 1 Inhibitors by Using 3D QSAR, Molecular Docking Study, and Molecular Dynamics Simulations

    Directory of Open Access Journals (Sweden)

    Xiaodong Gao

    2016-05-01

    Full Text Available Checkpoint kinase 1 (Chk1 is an important serine/threonine kinase with a self-protection function. The combination of Chk1 inhibitors and anti-cancer drugs can enhance the selectivity of tumor therapy. In this work, a set of 1,7-diazacarbazole analogs were identified as potent Chk1 inhibitors through a series of computer-aided drug design processes, including three-dimensional quantitative structure–activity relationship (3D-QSAR modeling, molecular docking, and molecular dynamics simulations. The optimal QSAR models showed significant cross-validated correlation q2 values (0.531, 0.726, fitted correlation r2 coefficients (higher than 0.90, and standard error of prediction (less than 0.250. These results suggested that the developed models possess good predictive ability. Moreover, molecular docking and molecular dynamics simulations were applied to highlight the important interactions between the ligand and the Chk1 receptor protein. This study shows that hydrogen bonding and electrostatic forces are key interactions that confer bioactivity.

  7. Contaminant exposure in terrestrial vertebrates

    International Nuclear Information System (INIS)

    Smith, Philip N.; Cobb, George P.; Godard-Codding, Celine; Hoff, Dale; McMurry, Scott T.; Rainwater, Thomas R.; Reynolds, Kevin D.

    2007-01-01

    Here we review mechanisms and factors influencing contaminant exposure among terrestrial vertebrate wildlife. There exists a complex mixture of biotic and abiotic factors that dictate potential for contaminant exposure among terrestrial and semi-terrestrial vertebrates. Chemical fate and transport in the environment determine contaminant bioaccessibility. Species-specific natural history characteristics and behavioral traits then play significant roles in the likelihood that exposure pathways, from source to receptor, are complete. Detailed knowledge of natural history traits of receptors considered in conjunction with the knowledge of contaminant behavior and distribution on a site are critical when assessing and quantifying exposure. We review limitations in our understanding of elements of exposure and the unique aspects of exposure associated with terrestrial and semi-terrestrial taxa. We provide insight on taxa-specific traits that contribute, or limit exposure to, transport phenomenon that influence exposure throughout terrestrial systems, novel contaminants, bioavailability, exposure data analysis, and uncertainty associated with exposure in wildlife risk assessments. Lastly, we identify areas related to exposure among terrestrial and semi-terrestrial organisms that warrant additional research. - Both biotic and abiotic factors determine chemical exposure for terrestrial vertebrates

  8. Effects of Multimedia and Schema Induced Analogical Reasoning on Science Learning

    Science.gov (United States)

    Zheng, R. Z.; Yang, W.; Garcia, D.; McCadden, E. P.

    2008-01-01

    The present study investigates the effects of multimedia and schema induced analogical reasoning on science learning. It involves 89 fourth grade elementary students in the north-east of the United States. Participants are randomly assigned into four conditions: (a) multimedia with analogy; (b) multimedia without analogy; (c) analogy without…

  9. Geologic Interpretation of Data Sets Collected by Planetary Analog Geology Traverses and by Standard Geologic Field Mapping. Part 1; A Comparison Study

    Science.gov (United States)

    Eppler, Dean B.; Bleacher, Jacob F.; Evans, Cynthia A.; Feng, Wanda; Gruener, John; Hurwitz, Debra M.; Skinner, J. A., Jr.; Whitson, Peggy; Janoiko, Barbara

    2013-01-01

    Geologic maps integrate the distributions, contacts, and compositions of rock and sediment bodies as a means to interpret local to regional formative histories. Applying terrestrial mapping techniques to other planets is challenging because data is collected primarily by orbiting instruments, with infrequent, spatiallylimited in situ human and robotic exploration. Although geologic maps developed using remote data sets and limited "Apollo-style" field access likely contain inaccuracies, the magnitude, type, and occurrence of these are only marginally understood. This project evaluates the interpretative and cartographic accuracy of both field- and remote-based mapping approaches by comparing two 1:24,000 scale geologic maps of the San Francisco Volcanic Field (SFVF), north-central Arizona. The first map is based on traditional field mapping techniques, while the second is based on remote data sets, augmented with limited field observations collected during NASA Desert Research & Technology Studies (RATS) 2010 exercises. The RATS mission used Apollo-style methods not only for pre-mission traverse planning but also to conduct geologic sampling as part of science operation tests. Cross-comparison demonstrates that the Apollo-style map identifies many of the same rock units and determines a similar broad history as the field-based map. However, field mapping techniques allow markedly improved discrimination of map units, particularly unconsolidated surficial deposits, and recognize a more complex eruptive history than was possible using Apollo-style data. Further, the distribution of unconsolidated surface units was more obvious in the remote sensing data to the field team after conducting the fieldwork. The study raises questions about the most effective approach to balancing mission costs with the rate of knowledge capture, suggesting that there is an inflection point in the "knowledge capture curve" beyond which additional resource investment yields progressively

  10. Electronic devices for analog signal processing

    CERN Document Server

    Rybin, Yu K

    2012-01-01

    Electronic Devices for Analog Signal Processing is intended for engineers and post graduates and considers electronic devices applied to process analog signals in instrument making, automation, measurements, and other branches of technology. They perform various transformations of electrical signals: scaling, integration, logarithming, etc. The need in their deeper study is caused, on the one hand, by the extension of the forms of the input signal and increasing accuracy and performance of such devices, and on the other hand, new devices constantly emerge and are already widely used in practice, but no information about them are written in books on electronics. The basic approach of presenting the material in Electronic Devices for Analog Signal Processing can be formulated as follows: the study with help from self-education. While divided into seven chapters, each chapter contains theoretical material, examples of practical problems, questions and tests. The most difficult questions are marked by a diamon...

  11. Hepatic Cyst Infection During Use of the Somatostatin Analog Lanreotide in Autosomal Dominant Polycystic Kidney Disease: An Interim Analysis of the Randomized Open-Label Multicenter DIPAK-1 Study

    NARCIS (Netherlands)

    Lantinga, M.A. (Marten A.); D’Agnolo, H.M.A. (Hedwig M. A.); E. Casteleijn (Eric); de Fijter, J.W. (Johan W.); E. Meijer (Esther); A.L. Messchendorp (A. Lianne); D. Peters (Dorien); M. Salih (Mahdi); E.M. Spithoven (Edwin); D. Soonawala (Darius); F.W. Visser (Folkert); Wetzels, J.F.M. (Jack F. M.); R. Zietse (Bob); J.P.H. Drenth (Joost); R.T. Gansevoort (Ron); Drenth, J.P.H.; J.W. de Fijter (Johan); Gansevoort, R.T.; D.J.M. Peters (Dorien J.M.); J.F.M. Wetzels (Jack); Zietse, R.

    2017-01-01

    textabstractIntroduction and Aims: The DIPAK-1 Study investigates the reno- and hepatoprotective efficacy of the somatostatin analog lanreotide compared with standard care in patients with later stage autosomal dominant polycystic kidney disease (ADPKD). During this trial, we witnessed several

  12. A single center, open, randomized study investigating the clinical safety and the endothelial modulating effects of a prostacyclin analog in combination with eptifibatide in patients having undergone primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction

    DEFF Research Database (Denmark)

    Holmvang, Lene; Ostrowski, Sisse Rye; Dridi, Nadia Paarup

    2012-01-01

    Treatment with the endothelial modulator prostacyclin may be beneficial in patients with endothelial dysfunction. The primary aim of the present pilot study was to evaluate the safety and the potential endothelial modulating affect of the prostacyclin analog iloprost in patients with a recent ST ...

  13. Optical analog transmission device

    International Nuclear Information System (INIS)

    Ikawa, Shinji.

    1994-01-01

    The present invention concerns a device such as electro-optical conversion elements, optoelectric-electric elements and optical transmission channel, not undergoing deleterious effects on the efficiency of conversion and transmission due to temperature, and aging change. That is, a sine wave superposing means superposes, on a detector signal to be transmitted, a sine-wave signal having a predetermined amplitude and at a frequency lower than that of the detector signal. An optoelectric conversion means converts the electric signal as the signal of the sine-wave signal superposing means into an optical signal and outputs the same to an optical transmitting channel. The optoelectric conversion means converts the transmitted signal to an electric signal. A discriminating means discriminates the electric signal into a detector signal and a sine-wave signal. A calculating means calculates an optical transmitting efficiency of the transmitting channel based on the amplitude of the discriminated sine-wave signal. A processing means compensates an amplitude value of the detector signals discriminated by the discriminating means based on the optical transmission efficiency. As a result, an optical analog transmission device can be attained, which conducts optical transmission at a high accuracy without undergoing the defective effects of the optical transmission efficiency. (I.S.)

  14. The relative roles of climate and land use in the degradation of a terrestrial ecosystem: a case study from Kjarardalur, West Iceland

    Science.gov (United States)

    Erlendsson, Egill; Gísladóttir, Guðrún

    2016-04-01

    Around AD 870 the virgin environment of Iceland became populated by humans and mammal land herbivores. Since then, the island has lost nearly all of its native birch woodland, resulting in dramatic degradation of landscapes and ecosystems, attributed mainly to over-exploitation of woodlands and late-medieval climate deterioration. As part of policy making in agriculture, a heated debate is ongoing over limitations to sheep grazing in pastures suffering from long-term degradation. In this context the history of climate and land use is of great importance. Those who consider grazing a minimal attribute to land degradation argue that the harsh climate conditions of the little ice age are the primary mechanism behind the current degraded landscape. Others err on the side of caution and propose a careful approach to grazing. This study forms a contribution to the historical context of the impact of grazing upon the Icelandic terrestrial ecosystem. Using the analyses of pollen and spores from coprophilous fungi as principal methods, we present data about historical environmental change from within two different land holdings in Kjarardalur Valley, West Iceland. One dataset comes from within a landholding governed by the chieftain farm Reykholt, the other comes from within the land of the indipendent farm, Norðtunga. In the past the valley was used primarily as a pasture, associated with shielings (organised seasonal grazing). Pollen data from the pasture in Kjarardalur Valley, West Iceland, demonstrate a rapid loss of birch (Betula pubescens) woodland from grazing areas owned by the major farm and institution, Reykholt. The suppressive nature of grazing is demonstrated by the expansion of woodland as soon when animal stocks are reduced, probably as a consequence of the bubonic plague after AD 1402. Resumed exploitation of resources eventually depleted all birch woodland from the Reykholt landholding and precipitated soil erosion. The trajectory of environmental change

  15. NaturAnalogs for the Unsaturated Zone

    Energy Technology Data Exchange (ETDEWEB)

    A. Simmons; A. Unger; M. Murrell

    2000-03-08

    The purpose of this Analysis/Model Report (AMR) is to document natural and anthropogenic (human-induced) analog sites and processes that are applicable to flow and transport processes expected to occur at the potential Yucca Mountain repository in order to build increased confidence in modeling processes of Unsaturated Zone (UZ) flow and transport. This AMR was prepared in accordance with ''AMR Development Plan for U0135, Natural Analogs for the UZ'' (CRWMS 1999a). Knowledge from analog sites and processes is used as corroborating information to test and build confidence in flow and transport models of Yucca Mountain, Nevada. This AMR supports the Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR) and the Yucca Mountain Site Description. The objectives of this AMR are to test and build confidence in the representation of UZ processes in numerical models utilized in the UZ Flow and Transport Model. This is accomplished by: (1) applying data from Boxy Canyon, Idaho in simulations of UZ flow using the same methodologies incorporated in the Yucca Mountain UZ Flow and Transport Model to assess the fracture-matrix interaction conceptual model; (2) Providing a preliminary basis for analysis of radionuclide transport at Pena Blanca, Mexico as an analog of radionuclide transport at Yucca Mountain; and (3) Synthesizing existing information from natural analog studies to provide corroborating evidence for representation of ambient and thermally coupled UZ flow and transport processes in the UZ Model.

  16. An analog silicon retina with multichip configuration.

    Science.gov (United States)

    Kameda, Seiji; Yagi, Tetsuya

    2006-01-01

    The neuromorphic silicon retina is a novel analog very large scale integrated circuit that emulates the structure and the function of the retinal neuronal circuit. We fabricated a neuromorphic silicon retina, in which sample/hold circuits were embedded to generate fluctuation-suppressed outputs in the previous study [1]. The applications of this silicon retina, however, are limited because of a low spatial resolution and computational variability. In this paper, we have fabricated a multichip silicon retina in which the functional network circuits are divided into two chips: the photoreceptor network chip (P chip) and the horizontal cell network chip (H chip). The output images of the P chip are transferred to the H chip with analog voltages through the line-parallel transfer bus. The sample/hold circuits embedded in the P and H chips compensate for the pattern noise generated on the circuits, including the analog communication pathway. Using the multichip silicon retina together with an off-chip differential amplifier, spatial filtering of the image with an odd- and an even-symmetric orientation selective receptive fields was carried out in real time. The analog data transfer method in the present multichip silicon retina is useful to design analog neuromorphic multichip systems that mimic the hierarchical structure of neuronal networks in the visual system.

  17. Natural Analogs for the Unsaturated Zone

    International Nuclear Information System (INIS)

    Simmons, A.; Unger, A.; Murrell, M.

    2000-01-01

    The purpose of this Analysis/Model Report (AMR) is to document natural and anthropogenic (human-induced) analog sites and processes that are applicable to flow and transport processes expected to occur at the potential Yucca Mountain repository in order to build increased confidence in modeling processes of Unsaturated Zone (UZ) flow and transport. This AMR was prepared in accordance with ''AMR Development Plan for U0135, Natural Analogs for the UZ'' (CRWMS 1999a). Knowledge from analog sites and processes is used as corroborating information to test and build confidence in flow and transport models of Yucca Mountain, Nevada. This AMR supports the Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR) and the Yucca Mountain Site Description. The objectives of this AMR are to test and build confidence in the representation of UZ processes in numerical models utilized in the UZ Flow and Transport Model. This is accomplished by: (1) applying data from Boxy Canyon, Idaho in simulations of UZ flow using the same methodologies incorporated in the Yucca Mountain UZ Flow and Transport Model to assess the fracture-matrix interaction conceptual model; (2) Providing a preliminary basis for analysis of radionuclide transport at Pena Blanca, Mexico as an analog of radionuclide transport at Yucca Mountain; and (3) Synthesizing existing information from natural analog studies to provide corroborating evidence for representation of ambient and thermally coupled UZ flow and transport processes in the UZ Model

  18. Quantitative palynofacies analysis as a new tool to study transfers of fossil organic matter in recent terrestrial environments

    Energy Technology Data Exchange (ETDEWEB)

    Graz, Y.; Di-Giovanni, C. [Universite d' Orleans, Universite Francois Rabelais - Tours, CNRS/INSU, Institut des Sciences de la Terre d' Orleans - UMR 6113 Campus Geosciences, 1A, rue de la Ferollerie, 45071 Orleans cedex 2 (France); Copard, Y. [M2C, UMR 6143 CNRS/Universite de Rouen, place E. Blondel, Bat. Irese A, Universite de Rouen, 76821 Mont Saint Aignan Cedex (France); Laggoun-Defarge, F.; Boussafir, M.; Lallier-Verges, E.; Baillif, P.; Perdereau, L.; Simonneau, A. [Universite d' Orleans, Universite Francois Rabelais - Tours, CNRS/INSU, Institut des Sciences de la Terre d' Orleans - UMR 6113 Campus Geosciences, 1A, rue de la Ferollerie, 45071 Orleans cedex 2 (France)

    2010-10-01

    Classical palynofacies method, which consists of an organic concentrate microscopic qualitative observation after mineral phase dissolution, is commonly used in order to study sedimentary organic matter. In the present study we develop a new quantitative palynofacies method that allows organic particles mass concentrations to be determined in studied samples. This method was developed to help quantify the input of fossil organic matter (FOM) into modern environments as a result of sedimentary rocks weathering. Studied samples were collected from different pools, like bedrocks, weathering profiles, soils and riverine particles in an experimental watershed ''Le Laval''. This watershed overlying Callovo-Oxfordian marls (1 km{sup 2} in area) is located near Digne, Alpes-de-Haute-Provence, in France. In addition to palynofacies techniques, Rock-Eval 6 pyrolysis and Al{sub 2}O{sub 3} content measurements (inductively coupled plasma emission spectrometry) were carried out on the samples. Obtained results show that this quantitative palynofacies method is suitable for FOM studies in modern environments, and FOM particles are quantified in the different pools. Results also give evidence that FOM alteration depends on the type of weathering, but also on the kind of organic particles. Soil formation under vegetation, resulting from the (bio)chemical weathering, lead to fossil organic particles concentration losses that do not exceed 30%. Elsewhere, mechanical weathering appears extremely fast and has no qualitative or quantitative influence on the observed FOM particles, which feeds directly into riverine stocks. FOM appears to be very resistant to weathering processes, this highlights its occurrence into supergene pools and then into carbon cycle. Quantitative palynofacies analysis is a new method adapted to such study, but can also be applied to other palynological, paleoenvironmental or archeological studies. (author)

  19. Morphological and allozyme studies of small terrestrial snails (Opeas sp., Subulina sp. and Huttonella bicolor) collected from Peninsular Malaysia.

    Science.gov (United States)

    Choh, M S; Yap, C K; Tan, S G; Jambari, H A

    2006-01-01

    Shell morphological characters and allozyme electrophoresis were used to study the relationships among six geographical populations of land snails collected from Peninsular Malaysia. Allozyme electrophoresis was used to study the genetic variations to complement the morphological features studied that included shell lengths, numbers of whorls and shell colour. Ten loci coding for six enzymes (MDH, LAP, ALP, PGM, G6PDH and EST) could be reliably scored in samples from the six populations studied. The dendrogram showed two major clusters with one cluster comprising Subulinidae populations from Perak, Selangor, Johor, Terengganu and Pahang while the other cluster included only the Streptaxidae Huttonella bicolor (red) population. The Subulinidae populations were grouped into two subclusters: one subcluster included the Subulina sp. populations from Perak, Selangor an Johor while the other subcluster included the Opeas sp. populations from Terengganu and Pahang. Morphological features can identify the different families and therefore they can complement the allozyme genetic studies on the land snail populations. Like other reports in the literature, our results also underline the importance of a genetic approach in conjunction with a morphological approach, for discriminating land snail species. The present results suggest that small land snails, which were similar in colour but different in sizes, were not of the same family/genus.

  20. Musik som analogi og metafor

    DEFF Research Database (Denmark)

    Bonde, Lars Ole

    2014-01-01

    Indeholder underkapitlerne: 2.5.1 Musik som analogi 2.5.2 Musik som metafor 2.5.3 Musikkens psykologiske funktioner - en taxonomi og metaforisk lytning til fire baroksatser......Indeholder underkapitlerne: 2.5.1 Musik som analogi 2.5.2 Musik som metafor 2.5.3 Musikkens psykologiske funktioner - en taxonomi og metaforisk lytning til fire baroksatser...

  1. Drawing Analogies in Environmental Education

    Science.gov (United States)

    Affifi, Ramsey

    2014-01-01

    Reconsidering the origin, process, and outcomes of analogy-making suggests practices for environmental educators who strive to disengage humans from the isolating illusions of dichotomizing frameworks. We can view analogies as outcomes of developmental processes within which human subjectivity is but an element, threading our sense of self back…

  2. The use of vitamin D analogs is independently associated with the favorable renal prognosis in chronic kidney disease stages 4-5: the CKD-ROUTE study.

    Science.gov (United States)

    Arai, Yohei; Kanda, Eiichiro; Iimori, Soichiro; Naito, Shotaro; Noda, Yumi; Kawasaki, Tomoki; Sato, Hidehiko; Ando, Ryoichi; Sasaki, Sei; Sohara, Eisei; Okado, Tomokazu; Rai, Tatemitsu; Uchida, Shinichi

    2017-06-01

    Vitamin D analogs have generally been recommended for treatment of mineral bone disease in chronic kidney disease (CKD). However, the association between this treatment and CKD progression has not yet been established. We designed a post hoc propensity score-matched cohort analysis derived from 3-year follow-up data of a prospective cohort. Adult participants with pre-dialysis CKD stages 4-5 who had newly been prescribed active vitamin D analogs during the observation period were eligible as matched cases. Then, matched controls were extracted from participants who had never been prescribed active vitamin D analogs. The primary outcome was a composite of end-stage renal disease or a 50 % reduction in estimated glomerular filtration rate (eGFR). A Cox proportional hazards model evaluated the association between the use of vitamin D analogs and the primary outcome. We enrolled 240 patients (males, 65 %). The number of matched cases and controls was 30 and 210, respectively. The primary outcome was observed in 94 patients, whereas 25 patients died. The mean ± standard deviation age and eGFR were 69 ± 12 years and 17 ± 5.7 ml/min/1.73 m 2 , respectively. In a Cox proportional hazard model, the use of vitamin D analogs was independently associated with a lower risk of the primary outcome (crude hazard ratio 0.41; 95 % confidence interval 0.19, 0.89; adjusted hazard ratio 0.38; 95 % confidence interval 0.17, 0.88). The use of vitamin D analogs is independently associated with the preservation of renal function in patients with pre-dialysis CKD stages 4-5.

  3. Terrestrial and exposure histories of Antarctic meteorites

    International Nuclear Information System (INIS)

    Nishiizumi, K.

    1986-01-01

    Records of cosmogenic effects were studied in a large suite of Antarctic meteorites. The cosmogenic nuclide measurements together with cosmic ray track measurements on Antartic meteorites provide information such as exposure age, terrestrial age, size and depth in meteoroid or parent body, influx rate in the past, and pairing. The terrestrail age is the time period between the fall of the meteorite on the Earth and the present. To define terrestrial age, two or more nuclides with different half-lives and possibly noble gases are required. The cosmogenic radionuclides used are C-14, Kr-81, Cl-36, Al-26, Be-10, Mn-53, and K-40

  4. Terrestrial and exposure histories of Antarctic meteorites

    Science.gov (United States)

    Nishiizumi, K.

    1986-01-01

    Records of cosmogenic effects were studied in a large suite of Antarctic meteorites. The cosmogenic nuclide measurements together with cosmic ray track measurements on Antartic meteorites provide information such as exposure age, terrestrial age, size and depth in meteoroid or parent body, influx rate in the past, and pairing. The terrestrail age is the time period between the fall of the meteorite on the Earth and the present. To define terrestrial age, two or more nuclides with different half-lives and possibly noble gases are required. The cosmogenic radionuclides used are C-14, Kr-81, Cl-36, Al-26, Be-10, Mn-53, and K-40.

  5. The future of vitamin D analogs

    Directory of Open Access Journals (Sweden)

    Carlien eLeyssens

    2014-04-01

    Full Text Available The active form of vitamin D3, 1,25-dihydroxyvitamin D3, is a major regulator of bone and calcium homeostasis. In addition, this hormone also inhibits the proliferation and stimulates the differentiation of normal as well as malignant cells. Supraphysiological doses of 1,25-dihydroxyvitamin D3 are required to reduce cancer cell proliferation. However, these doses will lead in vivo to calcemic side effects such as hypercalcemia and hypercalciuria. During the last 25 years, many structural analogs of 1,25-dihydroxyvitamin D3 have been synthesized by the introduction of chemical modifications in the A-ring, central CD-ring region or side chain of 1,25-dihydroxyvitamin D3 in the hope to find molecules with a clear dissociation between the beneficial antiproliferative effects and adverse calcemic side effects. One example of such an analog with a good dissociation ratio is calcipotriol (DaivonexR, which is clinically used to treat the hyperproliferative skin disease psoriasis. Other vitamin D analogs were clinically approved for the treatment of osteoporosis or secondary hyperparathyroidism. No vitamin D analog is currently used in the clinic for the treatment of cancer although several analogs have been shown to be potent drugs in animal models of cancer. Omics studies as well as in vitro cell biological experiments unraveled basic mechanisms involved in the antineoplastic effects of vitamin D and its analogs. 1,25-dihydroxyvitamin D3 and analogs act in a cell type- and tissue-specific manner. Moreover, a blockade in the transition of the G0/1 towards S phase of the cell cycle, induction of apoptosis, inhibition of migration and invasion of tumor cells together with effects on angiogenesis and inflammation have been implicated in the pleiotropic effects of 1,25-dihydroxyvitamin D3 and its analogs. In this review we will give an overview of the action of vitamin D analogs in tumor cells and look forward how these compounds could be introduced in the

  6. Comparative study on DOTA-derivatized bombesin analog labeled with {sup 90}Y and {sup 177}Lu: in vitro and in vivo evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Koumarianou, Eftychia [Institute R-RP, NCSR ' Demokritos' , Athens (Greece); IAE, Radioisotope Centre POLATOM, 05-400 Swierk-Otwock (Poland)], E-mail: eytyxiak@yahoo.com; Mikolajczak, Renata; Pawlak, Dariusz [IAE, Radioisotope Centre POLATOM, 05-400 Swierk-Otwock (Poland); Zikos, Xhristos; Bouziotis, Pinelopi [Institute R-RP, NCSR ' Demokritos' , Athens (Greece); Garnuszek, Piotr; Karczmarczyk, Urszula; Maurin, Michal [Department of Radiopharmaceuticals, National Medicines Institute, Chelmska 30/34, 00-725 Warsaw (Poland); Archimandritis, Spyridon C. [Institute R-RP, NCSR ' Demokritos' , Athens (Greece)

    2009-08-15

    Introduction: The aim of the study was to compare in vitro and in vivo a novel DOTA-chelated bombesin (BN) analog of the amino acid sequence, QRLGNQWAVGHLM-CONH{sub 2} (BN[2-14]NH{sub 2}), labeled with {sup 90}Y and {sup 177}Lu, for its potential use in targeted radiotherapy of tumors expressing gastrin releasing peptide (GRP) receptors. The same amino acid sequence, but with different chelator, referred as BN1.1 (Gly-Gly-Cys-Aca-QRLGNQWAVGHLM-CONH{sub 2}), has already been studied and reported; however, the DOTA-chelated one, suitable for labeling with M{sup +3} type radiometals, was not yet described. Methods: The conditions for labeling of DOTA-BN[2-14]NH{sub 2} with noncarrier added {sup 90}Y and with {sup 177}Lu [specific activity (SA), 15 Ci/mg Lu] were investigated and optimized to provide {sup 90}Y-DOTA-BN[2-14]NH{sub 2} and {sup 177}Lu-DOTA-BN[2-14]NH{sub 2} of high SA. The stability of the radiolabeled compounds in human serum was evaluated over a period of 24 h. The human prostate cancer cell line PC-3, known to express GRP receptors, was used for in vitro evaluation of radiolabeled peptide affinity to GRP receptors and for assessment of cytotoxicity of both nonlabeled and radiolabeled peptide. Biodistribution accompanied by receptor blocking was studied in normal Swiss mice. Results: {sup 90}Y-DOTA-BN[2-14]NH{sub 2} and {sup 177}Lu-DOTA-BN[2-14]NH{sub 2} were obtained with radiochemical yield >98% and high SA (67.3 GBq {sup 90}Y/{mu}mol and 33.6 GBq {sup 177}Lu/{mu}mol, respectively). They were stable when incubated in human serum for up to 24 h. The binding affinities of DOTA-BN[2-14]NH{sub 2} and both {sup nat}Y- and {sup nat}Lu-labeled analogs to GRP receptors were high (IC{sub 50}=1.78, 1.99, and 1.34 nM, respectively), especially for the {sup nat}Lu-DOTA-BN[2-14]NH{sub 2} complex. The cytotoxicity study of DOTA-BN[2-14]NH{sub 2} to PC-3 cells revealed an IC{sub 50}=6300 nM after 72 h of exposition, while the labeled derivatives showed no

  7. Comparative study on DOTA-derivatized bombesin analog labeled with 90Y and 177Lu: in vitro and in vivo evaluation

    International Nuclear Information System (INIS)

    Koumarianou, Eftychia; Mikolajczak, Renata; Pawlak, Dariusz; Zikos, Xhristos; Bouziotis, Pinelopi; Garnuszek, Piotr; Karczmarczyk, Urszula; Maurin, Michal; Archimandritis, Spyridon C.

    2009-01-01

    Introduction: The aim of the study was to compare in vitro and in vivo a novel DOTA-chelated bombesin (BN) analog of the amino acid sequence, QRLGNQWAVGHLM-CONH 2 (BN[2-14]NH 2 ), labeled with 90 Y and 177 Lu, for its potential use in targeted radiotherapy of tumors expressing gastrin releasing peptide (GRP) receptors. The same amino acid sequence, but with different chelator, referred as BN1.1 (Gly-Gly-Cys-Aca-QRLGNQWAVGHLM-CONH 2 ), has already been studied and reported; however, the DOTA-chelated one, suitable for labeling with M +3 type radiometals, was not yet described. Methods: The conditions for labeling of DOTA-BN[2-14]NH 2 with noncarrier added 90 Y and with 177 Lu [specific activity (SA), 15 Ci/mg Lu] were investigated and optimized to provide 90 Y-DOTA-BN[2-14]NH 2 and 177 Lu-DOTA-BN[2-14]NH 2 of high SA. The stability of the radiolabeled compounds in human serum was evaluated over a period of 24 h. The human prostate cancer cell line PC-3, known to express GRP receptors, was used for in vitro evaluation of radiolabeled peptide affinity to GRP receptors and for assessment of cytotoxicity of both nonlabeled and radiolabeled peptide. Biodistribution accompanied by receptor blocking was studied in normal Swiss mice. Results: 90 Y-DOTA-BN[2-14]NH 2 and 177 Lu-DOTA-BN[2-14]NH 2 were obtained with radiochemical yield >98% and high SA (67.3 GBq 90 Y/μmol and 33.6 GBq 177 Lu/μmol, respectively). They were stable when incubated in human serum for up to 24 h. The binding affinities of DOTA-BN[2-14]NH 2 and both nat Y- and nat Lu-labeled analogs to GRP receptors were high (IC 50 =1.78, 1.99, and 1.34 nM, respectively), especially for the nat Lu-DOTA-BN[2-14]NH 2 complex. The cytotoxicity study of DOTA-BN[2-14]NH 2 to PC-3 cells revealed an IC 50 =6300 nM after 72 h of exposition, while the labeled derivatives showed no significant cytotoxic effect. The internalization rate to PC-3 cells was more rapid for 177 Lu-labeled peptide (84.87%) than for the 90 Y

  8. Terrestrial movements and habitat use of gopher frogs in longleaf pine forests: a comparative study of juveniles and adults

    Science.gov (United States)

    Elizabeth A. Roznik; Steve A. Johnson; Cathryn H. Greenberg; George W. Tanner

    2009-01-01

    Many animals exhibit changes in patterns of movement and habitat use as they age, and understanding such ontogenetic shifts is important for ensuring that habitat management is appropriate for all life stages. We used radiotelemetry to study movements and habitat use of juvenile and adult gopher frogs (Rana capito) as they migrated from the same ponds following...

  9. Terrestrial Water Storage

    Science.gov (United States)

    Rodell, M.; Chambers, D. P.; Famiglietti, J. S.

    2015-01-01

    During 2014 dryness continued in the Northern Hemisphere and relative wetness continued in the Southern Hemisphere (Fig. 2.21; Plate 2.1g). These largely canceled out such that the global land surface began and ended the year with a terrestrial water storage (TWS) anomaly slightly below 0 cm (equivalent height of water; Fig. 2.22). TWS is the sum of groundwater, soil moisture, surface water, snow, and ice. Groundwater responds more slowly to meteorological phenomena than the other components because the overlying soil acts as a low pass filter, but often it has a larger range of variability on multiannual timescales (Rodell and Famiglietti 2001; Alley et al. 2002).In situ groundwater data are only archived and made and Tanzania. The rest of the continent experienced mixed to dry conditions. Significant reductions in TWS in Greenland, Antarctica, and southern coastal Alaska reflect ongoing ice sheet and glacier ablation, not groundwater depletion.

  10. Development and Comparative Study of Effects of Training Algorithms on Performance of Artificial Neural Network Based Analog and Digital Automatic Modulation Recognition

    Directory of Open Access Journals (Sweden)

    Jide Julius Popoola

    2015-11-01

    Full Text Available This paper proposes two new classifiers that automatically recognise twelve combined analog and digital modulated signals without any a priori knowledge of the modulation schemes and the modulation parameters. The classifiers are developed using pattern recognition approach. Feature keys extracted from the instantaneous amplitude, instantaneous phase and the spectrum symmetry of the simulated signals are used as inputs to the artificial neural network employed in developing the classifiers. The two developed classifiers are trained using scaled conjugate gradient (SCG and conjugate gradient (CONJGRAD training algorithms. Sample results of the two classifiers show good success recognition performance with an average overall recognition rate above 99.50% at signal-to-noise ratio (SNR value from 0 dB and above with the two training algorithms employed and an average overall recognition rate slightly above 99.00% and 96.40% respectively at - 5 dB SNR value for SCG and CONJGRAD training algorithms. The comparative performance evaluation of the two developed classifiers using the two training algorithms shows that the two training algorithms have different effects on both the response rate and efficiency of the two developed artificial neural networks classifiers. In addition, the result of the performance evaluation carried out on the overall success recognition rates between the two developed classifiers in this study using pattern recognition approach with the two training algorithms and one reported classifier in surveyed literature using decision-theoretic approach shows that the classifiers developed in this study perform favourably with regard to accuracy and performance probability as compared to classifier presented in previous study.

  11. Sensitivity of terrestrial ecosystems to elevated atmospheric CO{sub 2}: Comparisons of model simulation studies to CO{sub 2} effect

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Y. [Marine Biological Lab., Woods Hole, MA (United States)

    1995-06-01

    In the context of a project to compare terrestrial ecosystem models, the Vegetation/Ecosystem Modeling and Analysis Project (VEMAP), we have analyzed how three biogeochemistry models link plant growth to doubled atmospheric CO{sub 2}. A common set of input data was used to drive three biogeochemistry models, BIOME-BGC, CENTURY and TEM. For the continental United States the simulation results show that with doubled CO{sub 2}, NPP increased by 8.7%, 5.0% and 10.8% for TEM, CENTURY and BIOME-BGC, respectively. At the biome level the range of NPP estimates varied considerably among models. TEM-simulated enhancement of NPP ranged from 2% to 28%; CENTURY, from 2% to 9%; and BIOME-BGC, from 4% to 27%. A transect analysis across several biomes along a latitude at 41.5 N shows that the TEM-simulated CO{sub 2} enhancement of NPP ranged from 0% to 22%; CENTURY, from 1% to 10% and BIOME-BGC, from 1% to 63%. In this study, we have investigated the underlying mechanisms of the three models to reveal how increased CO{sub 2} affects photosynthesis rate, water using efficiency and nutrient cycles. The relative importance of these mechanisms in each of the three biogeochemistry models will be discussed.

  12. Tectono-sedimentary analysis using the anisotropy of magnetic susceptibility: a study of the terrestrial and freshwater Neogene of the Orava Basin

    Science.gov (United States)

    Łoziński, Maciej; Ziółkowski, Piotr; Wysocka, Anna

    2017-10-01

    The Orava Basin is an intramontane depression filled with presumably fine-grained sediments deposited in river, floodplain, swamp and lake settings. The basin infilling constitutes a crucial record of the neoalpine evolution of the Inner/Outer Carpathian boundary area since the Neogene, when the Jurassic-Paleogene basement became consolidated, uplifted and eroded. The combination of sedimentological and structural studies with anisotropy of magnetic susceptibility (AMS) measurements provided an effective tool for recognition of terrestrial environments and deformations of the basin infilling. The lithofacies-oriented sampling and statistical approach to the large dataset of AMS specimens were utilized to define 12 AMS facies based on anisotropy degree (P) and shape (T). The AMS facies allowed a distinction of sedimentary facies ambiguous for classical methods, especially floodplain and lacustrine sediments, as well as revealing their various vulnerabilities to tectonic modification of AMS. A spatial analysis of facies showed that tuffites along with lacustrine and swamp deposits were generally restricted to marginal and southern parts of the basin. Significant deformations were noticed at basin margins and within two intrabasinal tectonic zones, which indicated the tectonic activity of the Pieniny Klippen Belt after the Middle Miocene. The large southern area of the basin recorded consistent N-NE trending compression during basin inversion. This regional tectonic rearrangement resulted in a partial removal of the southernmost basin deposits and shaped the basin's present-day extent.

  13. Terrestrial sedimentary pyrites as a potential source of trace metal release to groundwater – A case study from the Emsland, Germany

    International Nuclear Information System (INIS)

    Houben, Georg J.; Sitnikova, Maria A.; Post, Vincent E.A.

    2017-01-01

    Pyrite is a common minor constituent of terrestrial freshwater sediments and a sink for trace elements. Different amounts and morphological types (framboids and euhedral crystals) of sedimentary pyrites were found in the heavy mineral fraction of cores obtained from several drillholes located in the Emsland region, NW Germany. Their trace element contents were investigated to assess their potential for groundwater contamination after oxidation, e.g. induced by dewatering or autotrophic denitrification. Nickel, arsenic and cadmium were found in significant concentrations in pyrite. Geochemical modeling showed that elevated trace metal concentrations in groundwater, potentially exceeding drinking water standards, should preferentially occur in a less than 1 m thick zone situated around the depth of the redoxcline, where nitrate is reduced by pyrite. This was confirmed by depth-specific groundwater sampling in the Emsland and by previously published studies. The absolute concentration of released trace metals depends on their content in the pyrite but also strongly on the nitrate load of groundwater. - Highlights: • Pyrite from heavy mineral fraction of aquifer sediment analyzed for trace metal content. • Pyrites contain significant concentration of trace metals, such as nickel, arsenic, cadmium. • Trace elements are released by autotrophic denitrification. • Reactive transport model predicts small zone of trace element accumulation. • Release of trace elements strongly dependent on nitrate content of groundwater.

  14. Changes in analogical reasoning in adulthood.

    Science.gov (United States)

    Clark, E; Gardner, M K; Brown, G; Howell, R J

    1990-01-01

    This study sought to investigate adult intellectual development through an analysis of a particular type of cognitive ability, verbal analogical reasoning. The performance of 60 individuals between the ages of 20 and 79 was compared on 100 verbal analogies. The subjects consisted of six groups of ten individuals each (five males and five females), matched as a group for education and gender. Solution times and error rates served as the dependent measures. Results showed that there was a significant trend for the older subjects (60- and 70-year-olds) to be slower than the young subjects (20-, 30-, 40-, and 50-year-olds), but not necessarily more error prone. These data suggest that verbal analogical reasoning changes with age. Supplemental data demonstrated a change in other abilities as well (i.e., decline in perceptual-motor speed and spatial skill).

  15. Electrical analog of a Josephson junction

    International Nuclear Information System (INIS)

    Goldman, A.M.

    1979-01-01

    It is noted that a mathematical description of the phase-coupling of two oscillators synchronized by a phase-lock-loop under the influence of thermal white noise is analogous to that of the phase coupling of two superconductors in a Josephson junction also under the influence of noise. This analogy may be useful in studying threshold instabilities of the Josephson junction in regimes not restricted to the case of large damping. This is of interest because the behavior of the mean voltage near the threshold current can be characterized by critical exponents which resemble those exhibited by an order parameter of a continuous phase transition. As it is possible to couple a collection of oscillators together in a chain, the oscillator analogy may also be useful in exploring the dynamics and statistical mechanics of coupled junctions

  16. The analogic model ''RIC'' of thermal behaviour of mass concrete

    International Nuclear Information System (INIS)

    Gonzalez Redondo, M.; Gonzalez de Posada, F.; Plana Claver, J.

    1997-01-01

    In order to study the thermal field and calorific flows in heat sources (i.e. mass concrete during setting) we have conceived, built and experimented with an analogical electric model. This model, named RIC, consists of resistors (R) and capacitors (C) in which nodes an electric current (I) has been injected. Several analogical constants were used for the mathematical approximation. Thus, this paper describes the analogical RIC model, simulating heat generation, boundary and initial conditions and concreting. (Author) 4 refs

  17. Coordinating Chemical and Mineralogical Analyses of Antarctic Dry Valley Sediments as Potential Analogs for Mars

    Science.gov (United States)

    Patel, S. N.; Bishop, J. L.; Englert, P.; Gibson, E. K.

    2015-01-01

    The Antarctic Dry Valleys (ADV) provide a unique terrestrial analog for Martian surface processes as they are extremely cold and dry sedimentary environments. The surface geology and the chemical composition of the Dry Valleys that are similar to Mars suggest the possible presence of these soil-formation processes on Mars. The soils and sediments from Wright Valley, Antarctica were investigated in this study to examine mineralogical and chemical changes along the surface layer in this region and as a function of depth. Surface samples collected near Prospect Mesa and Don Juan Pond of the ADV were analyzed using visible/near-infrared (VNIR) and mid-IR reflectance spectroscopy and major and trace element abundances.

  18. Joint Terrestrial and Aerial Measurements to Study Ground Deformation: Application to the Sciara Del Fuoco at the Stromboli Volcano (Sicily

    Directory of Open Access Journals (Sweden)

    Alessandro Bonforte

    2016-05-01

    Full Text Available The 2002–2003 Stromboli eruption triggered the failure of part of the Sciara del Fuoco slope, which generated a tsunami that struck the island and the northern coastline of Sicily. The Sciara del Fuoco is a very steep slope where all lava flows from the craters’ emplacement; most lateral eruptions usually take place from fissures propagating in this sector of the volcano. The eruption went on to produce a lava field that filled the area affected by the landslide. This in turn led to further instability, renewing the threat of another slope failure and a potentially related tsunami. This work describes a new joint approach, combining surveying data and aerial image correlometry methods, to study the motion of this unstable slope. The combination has the advantage of very precise surveying measurements, which can be considered the ground truth to constrain the very-high-resolution aerial photogrammetric data, thereby obtaining highly detailed and accurate ground deformation maps. The joint use of the two methods can be very useful to obtain a more complete image of the deformation field for monitoring dangerous and/or rather inaccessible places. The proposed combined methodology improves our ability to study and assess hazardous processes associated with significant ground deformation.

  19. Analogical reasoning abilities of recovering alcoholics.

    Science.gov (United States)

    Gardner, M K; Clark, E; Bowman, M A; Miller, P J

    1989-08-01

    This study investigated analogical reasoning abilities of alcoholics who had been abstinent from alcohol for at least 1 year. Their performance was compared to that of nonalcoholic controls matched as a group for education, age, and gender. Solution times and error rates were modeled using a regression model. Results showed a nonsignificant trend for alcoholics to be faster, but more error prone, than controls. The same componential model applied to both groups, and fit them equally well. Although differences have been found in analogical reasoning ability between controls and alcoholics immediately following detoxification, we find no evidence of differences after extended periods of sobriety.

  20. Analogy Mapping Development for Learning Programming

    Science.gov (United States)

    Sukamto, R. A.; Prabawa, H. W.; Kurniawati, S.

    2017-02-01

    Programming skill is an important skill for computer science students, whereas nowadays, there many computer science students are lack of skills and information technology knowledges in Indonesia. This is contrary with the implementation of the ASEAN Economic Community (AEC) since the end of 2015 which is the qualified worker needed. This study provided an effort for nailing programming skills by mapping program code to visual analogies as learning media. The developed media was based on state machine and compiler principle and was implemented in C programming language. The state of every basic condition in programming were successful determined as analogy visualization.

  1. Ancient Terrestrial Carbon: Lost and Found

    Science.gov (United States)

    Freeman, K. H.

    2017-12-01

    Carbon fluxes in terrestrial environments dominate the global carbon cycle. The fluxes of terrestrial carbon are strongly tied to regional climate due to the influences of temperature, water, and nutrient dynamics on plant productivity. However, climate also influences the destruction of terrestrial organic matter, through weathering, erosion, and biomass loss via fire and oxidative microbial processes. Organic geochemical methods enable us to interrogate past terrestrial carbon dynamics and learn how continental processes might accelerate, or mitigate carbon transfer to the atmosphere, and the associated greenhouse warming. Terrestrial soil systems represent the weathering rind of the continents, and are inherently non-depositional and erosive. The production, transport, and depositional processes affecting organics in continental settings each impart their own biases on the amount and characteristics of preserved carbon. Typically, the best archives for biomarker records are sediments in ancient lakes or subaqueous fans, which represents a preservation bias that tends to favor wetter environments. Paleosols, or ancient soils, formed under depositional conditions that, for one reason or another, truncated soil ablation, erosion, or other loss processes. In modern soils, widely ranging organic carbon abundances are almost always substantially greater than the trace amounts of carbon left behind in ancient soils. Even so, measureable amounts of organic biomarkers persist in paleosols. We have been investigating processes that preserve soil organic carbon on geologic timescales, and how these mechanisms may be sensitive to past climate change. Climate-linked changes in temperature, moisture, pH, and weathering processes can impact carbon preservation via organo-mineral sorption, soil biogeochemistry, and stability based on the physical and chemical properties of organic compounds. These will be discussed and illustrated with examples from our studies of Cenozoic

  2. Study on the application of NASA energy management techniques for control of a terrestrial solar water heating system

    Science.gov (United States)

    Swanson, T. D.; Ollendorf, S.

    1979-01-01

    This paper addresses the potential for enhanced solar system performance through sophisticated control of the collector loop flow rate. Computer simulations utilizing the TRNSYS solar energy program were performed to study the relative effect on system performance of eight specific control algorithms. Six of these control algorithms are of the proportional type: two are concave exponentials, two are simple linear functions, and two are convex exponentials. These six functions are typical of what might be expected from future, more advanced, controllers. The other two algorithms are of the on/off type and are thus typical of existing control devices. Results of extensive computer simulations utilizing actual weather data indicate that proportional control does not significantly improve system performance. However, it is shown that thermal stratification in the liquid storage tank may significantly improve performance.

  3. Terrestrial Permafrost Models of Martian Habitats and Inhabitants

    Science.gov (United States)

    Gilichinsky, D.

    2011-12-01

    The terrestrial permafrost is the only rich depository of viable ancient microorganisms on Earth, and can be used as a bridge to possible Martian life forms and shallow subsurface habitats where the probability of finding life is highest. Since there is a place for water, the requisite condition for life, the analogous models are more or less realistic. If life ever existed on Mars, traces might have been preserved and could be found at depth within permafrost. The age of the terrestrial isolates corresponds to the longevity of the frozen state of the embedding strata, with the oldest known dating back to the late Pliocene in Arctic and late Miocene in Antarctica. Permafrost on Earth and Mars vary in age, from a few million years on Earth to a few billion years on Mars. Such a difference in time scale would have a significant impact on the possibility of preserving life on Mars, which is why the longevity of life forms preserved within terrestrial permafrost can only be an approximate model for Mars. 1. A number of studies indicate that the Antarctic cryosphere began to develop on the Eocene-Oligocene boundary, after the isolation of the continent. Permafrost degradation is only possible if mean annual ground temperature, -28°C now, rise above freezing, i.e., a significant warming to above 25°C is required. There is no evidence of such sharp temperature increase, which indicates that the climate and geological history was favorable to persistence of pre-Pliocene permafrost. These oldest relics (~30Myr) are possibly to be found at high hypsometric levels of ice-free areas (Dry Valleys and nearby mountains). It is desirable to test the layers for the presence of viable cells. The limiting age, if one exists, within this ancient permafrost, where the viable organisms were no longer present, could be established as the limit for life preservation below 0oC. Positive results will extend the known temporal limits of life in permafrost. 2. Even in this case, the age of

  4. Divergent apparent temperature sensitivity of terrestrial ecosystem respiration

    Science.gov (United States)

    Bing Song; Shuli Niu; Ruise Luo; Yiqi Luo; Jiquan Chen; Guirui Yu; Janusz Olejnik; Georg Wohlfahrt; Gerard Kiely; Ako Noormets; Leonardo Montagnani; Alessandro Cescatti; Vincenzo Magliulo; Beverly Elizabeth Law; Magnus Lund; Andrej Varlagin; Antonio Raschi; Matthias Peichl; Mats B. Nilsson; Lutz Merbold

    2014-01-01

    Recent studies revealed convergent temperature sensitivity of ecosystem respiration (Re) within aquatic ecosystems and between terrestrial and aquatic ecosystems. We do not know yet whether various terrestrial ecosystems have consistent or divergent temperature sensitivity. Here, we synthesized 163 eddy covariance flux sites across the world and...

  5. FLEX (Fluorescence Explorer mission: Observation fluorescence as a new remote sensing technique to study the global terrestrial vegetation state

    Directory of Open Access Journals (Sweden)

    J. Moreno

    2014-06-01

    Full Text Available FLEX (Fluorescence EXplorer is a candidate for the 8th ESA’s Earth Explorer mission. Is the first space mission specifically designed for the estimation of vegetation fluorescence on a global scale. The mission is proposed to fly in tandem with the future ESA´s Sentinel-3 satellite. It is foreseen that the information obtained by Sentinel-3 will be supplemented with that provided by FLORIS (Fluorescence Imaging Spectrometer onboard FLEX. FLORIS will measure the radiance between 500 and 800 nm with a bandwidth between 0.1 nm and 2 nm, providing images with a 150 km swath and 300 m pixel size. This information will allow a detailed monitoring of vegetation dynamics, by improving the methods for the estimation of classical biophysical parameters, and by introducing a new one: fluorescence. This paper presents the current status of FLEX mission in A/B1 phase and the different ongoing studies, campaigns and projects carried out in support of the FLEX mission.

  6. Epoxyeicosatrienoic acid analog attenuates the development of malignant hypertension, but does not reverse it once established: a study in Cyp1a1-Ren-2 transgenic rats

    Czech Academy of Sciences Publication Activity Database

    Jíchová, Š.; Kopkan, L.; Husková, Z.; Doleželová, Š.; Neckář, Jan; Kujal, P.; Vernerová, Z.; Kramer, H. J.; Sadowski, J.; Kompanowska; Jezierska, E.; Reddy, N. R.; Falck, J. R.; Imig, J. D.; Červenka, L.

    2016-01-01

    Roč. 34, č. 10 (2016), s. 2008-2025 ISSN 0263-6352 R&D Projects: GA ČR(CZ) GA15-07544S Institutional support: RVO:67985823 Keywords : epoxyeicosatrienoic acid analog * malignant hypertension * renal blood flow autoregulation * renin-angiotensin system * sodium excretion Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 4.085, year: 2016

  7. Study of Diagenetic Features in Rudist Buildups of Cretaceous Edwards Formation Using Ground Based Hyperspectral Scanning and Terrestrial LiDAR

    Science.gov (United States)

    Krupnik, D.; Khan, S.; Okyay, U.; Hartzell, P. J.; Biber, K.

    2015-12-01

    Ground based remote sensing is a novel technique for development of digital outcrop models which can be instrumental in performing detailed qualitative and quantitative sedimentological analysis for the study of depositional environment, diagenetic processes, and hydrocarbon reservoir characterization. For this investigation, ground-based hyperspectral data collection is combined with terrestrial LiDAR to study outcrops of Late Albian rudist buildups of the Edwards formation in the Lake Georgetown Spillway in Williamson County, Texas. The Edwards formation consists of shallow water deposits of reef and associated inter-reef facies, including rudist bioherms and biostromes. It is a significant aquifer and was investigated as a hydrocarbon play in south central Texas. Hyperspectral data were used to map compositional variation in the outcrop by distinguishing spectral properties unique to each material. Lithological variation was mapped in detail to investigate the structure and composition of rudist buildups. Hyperspectral imagery was registered to a 3D model produced from the LiDAR point cloud with an accuracy of up to one pixel. Flat-topped toucasid-rich bioherm facies were distinguished from overlying toucasid-rich biostrome facies containing chert nodules, overlying sucrosic dolostones, and uppermost peloid wackestones and packstones of back-reef facies. Ground truth was established by petrographic study of samples from this area and has validated classification products of remote sensing data. Several types of porosity were observed and have been associated with increased dolomitization. This ongoing research involves integration of remotely sensed datasets to analyze geometrical and compositional properties of this carbonate formation at a finer scale than traditional methods have achieved and seeks to develop a workflow for quick and efficient ground based remote sensing-assisted outcrop studies.

  8. Hydrothermal simulation experiments as a tool for studies of the origin of life on Earth and other terrestrial planets: a review.

    Science.gov (United States)

    Holm, Nils G; Andersson, Eva

    2005-08-01

    The potential of life's origin in submarine hydrothermal systems has been evaluated by a number of investigators by conducting high temperature-high pressure experiments involving organic compounds. In the majority of these experiments little attention has been paid to the importance of constraining important parameters, such as the pH and the redox state of the system. This is particularly revealed in the apparent difficulties in interpreting experimental data from hydrothermal organic synthesis and stability studies. However, in those cases where common mineral assemblages have been used in an attempt to buffer the pH and redox conditions to geologically and geochemically realistic values, theoretical and experimental data seem to converge. The use of mineral buffer assemblages provides a convenient way by which to constrain the experimental conditions. Studies at high temperatures and pressure in the laboratory have revealed a number of reactions that proceed rapidly in hydrothermal fluids, including the Strecker synthesis of amino acids. In other cases, the verification of postulated abiotic reaction mechanisms has not been possible, at least for large molecules such as large fatty acids and hydrocarbons. This includes the Fischer-Tropsch synthesis reaction. High temperature-high pressure experimental methods have been developed and used successfully for a long time in, for example, mineral solubility studies under hydrothermal conditions. By taking advantage of this experimental experience new and, at times, unexpected directions can be taken in bioorganic geochemistry, one being, for instance, primitive two-dimensional information coding. This article critically reviews some of the organic synthesis and stability experiments that have been conducted under simulated submarine hydrothermal conditions. We also discuss some of the theoretical and practical considerations that apply to hydrothermal laboratory studies of organic molecules related to the origin of

  9. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J M

    2010-01-01

    The design of an analog-to-digital converter or digital-to-analog converter is one of the most fascinating tasks in micro-electronics. In a converter the analog world with all its intricacies meets the realm of the formal digital abstraction. Both disciplines must be understood for an optimum conversion solution. In a converter also system challenges meet technology opportunities. Modern systems rely on analog-to-digital converters as an essential part of the complex chain to access the physical world. And processors need the ultimate performance of digital-to-analog converters to present the results of their complex algorithms. The same progress in CMOS technology that enables these VLSI digital systems creates new challenges for analog-to-digital converters: lower signal swings, less power and variability issues. Last but not least, the analog-to-digital converter must follow the cost reduction trend. These changing boundary conditions require micro-electronics engineers to consider their design choices for...

  10. Analog fourier transform channelizer and OFDM receiver

    OpenAIRE

    2007-01-01

    An OFDM receiver having an analog multiplier based I-Q channelizing filter, samples and holds consecutive analog I-Q samples of an I-Q baseband, the I-Q basebands having OFDM sub-channels. A lattice of analog I-Q multipliers and analog I-Q summers concurrently receives the held analog I-Q samples, performs analog I-Q multiplications and analog I-Q additions to concurrently generate a plurality of analog I-Q output signals, representing an N-point discrete Fourier transform of the held analog ...

  11. Children's analogical reasoning in a third-grade science discussion

    Science.gov (United States)

    May, David B.; Hammer, David; Roy, Patricia

    2006-03-01

    Expert scientific inquiry involves the generation and use of analogies. How and when students might develop this aspect of expertise has implications for understanding how and when instruction might facilitate that development. In a study of K-8 student inquiry in physical science, we are examining cases of spontaneous analogy generation. In the case we present here, a third-grader generates an analogy and modifies it to reconcile his classmates' counterarguments, allowing us to identify in these third-graders specific aspects of nascent expertise in analogy use. Promoting abilities and inclinations such as these children display requires that educators recognize and respond to them.

  12. Isobaric analog states in rare-earth nuclei studied with the (3He,t) charge-exchange reaction at thetasub(L)=00

    International Nuclear Information System (INIS)

    Jaenecke, J.

    1983-01-01

    The ( 3 He, t) charge-exchange reaction leading to the ground-state isobaric analog states (IAS) of sup(152, 154, 156, 158, 160)Gd, sup(160, 162)Dy, sup(162, 164, 166, 168, 170)Er, sup(170, 172, 174, 176)Yb and sup(176, 178, 180)Hf has been studied at thetasub(L) = 0 0 and E( 3 He) = 60.5 MeV. The reaction 28 Si( 3 He, t) 28 P was used for energy calibration. The centroid energies of most IAS were determined to +- 6 keV. Coulomb displacement energies have been extracted from the measured Q-values. They display the influence of non-spherical nuclear shapes which increase the rms radii and lower the Coulomb displacement energies. The dependence on both quadrupole and hexadecapole deformations is apparent with deformation parameters in good agreement with results from other measurements. The total widths GAMMA of the IAS are in the range 30 to 110 keV. They increase more strongly with neutron excess than is known for the IAS of the Sn and Te isotopes. The width of the IAS of 176 Yb is anomalously low. The zero-degree ( 3 He, t) cross sections are in the range 5 to 20 μb/sr. They generally increase with neutron excess except for the sequence of Yb isotopes. No systematic dependence on (N - Z) appears to exist. Excitation energies and zero-degree cross sections for the reactions 28 Si( 3 He, t) 28 P, 16 O( 3 He, t) 16 F and 12 C( 3 He,t) 12 N are reported. (orig.)

  13. Is the Link from Working Memory to Analogy Causal? No Analogy Improvements following Working Memory Training Gains

    Science.gov (United States)

    Richey, J. Elizabeth; Phillips, Jeffrey S.; Schunn, Christian D.; Schneider, Walter

    2014-01-01

    Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data [1], but less work has tested this relationship through experimental manipulation [2]. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working memory tasks. This study investigated whether working memory improvements, if replicated, would increase analogical reasoning ability. We assessed participants’ performance on verbal and visual analogy tasks after a complex working memory training program incorporating verbal and spatial tasks [3], [4]. Participants’ improvements on the working memory training tasks transferred to other short-term and working memory tasks, supporting the possibility of broad effects of working memory training. However, we found no effects on analogical reasoning. We propose several possible explanations for the lack of an impact of working memory improvements on analogical reasoning. PMID:25188356

  14. Is the link from working memory to analogy causal? No analogy improvements following working memory training gains.

    Directory of Open Access Journals (Sweden)

    J Elizabeth Richey

    Full Text Available Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data, but less work has tested this relationship through experimental manipulation. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working memory tasks. This study investigated whether working memory improvements, if replicated, would increase analogical reasoning ability. We assessed participants' performance on verbal and visual analogy tasks after a complex working memory training program incorporating verbal and spatial tasks. Participants' improvements on the working memory training tasks transferred to other short-term and working memory tasks, supporting the possibility of broad effects of working memory training. However, we found no effects on analogical reasoning. We propose several possible explanations for the lack of an impact of working memory improvements on analogical reasoning.

  15. Is the link from working memory to analogy causal? No analogy improvements following working memory training gains.

    Science.gov (United States)

    Richey, J Elizabeth; Phillips, Jeffrey S; Schunn, Christian D; Schneider, Walter

    2014-01-01

    Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data, but less work has tested this relationship through experimental manipulation. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working memory tasks. This study investigated whether working memory improvements, if replicated, would increase analogical reasoning ability. We assessed participants' performance on verbal and visual analogy tasks after a complex working memory training program incorporating verbal and spatial tasks. Participants' improvements on the working memory training tasks transferred to other short-term and working memory tasks, supporting the possibility of broad effects of working memory training. However, we found no effects on analogical reasoning. We propose several possible explanations for the lack of an impact of working memory improvements on analogical reasoning.

  16. Using Analogies to Prevent Misconceptions about Chemical Equilibrium

    Science.gov (United States)

    Sahin Pekmez, Esin

    2010-01-01

    The main purpose of this study was to find the effectiveness of using analogies to prevent misconceptions about chemical equilibrium. Nineteen analogies, which were based on dynamic aspects of chemical equilibrium and application of Le Chatelier's principle, were developed. The participations of this study consisted of 11th grade students (n: 151)…

  17. Gemini analogs of vitamin D.

    Science.gov (United States)

    Pazos, Gonzalo; Rivadulla, Marcos L; Pérez-García, Xenxo; Gandara, Zoila; Pérez, Manuel

    2014-01-01

    The Gemini analogs are the last significant contribution to the family of vitamin D derivatives in medicine, for the treatment of cancer. The first Gemini analog was characterized by two symmetric side chains at C-20. Following numerous modifications, the most active analog bears a C-23-triple bond, C-26, 27- hexafluoro substituents on one side chain and a terminal trideuteromethylhydroxy group on the other side chain. This progression was possible due to improvements in the synthetic methods for the preparation of these derivatives, which allowed for increasing molecular complexity and complete diastereoselective control at C-20 and the substituted sidechains.

  18. 64Cu-DOTA as a surrogate positron analog of Gd-DOTA for cardiac fibrosis detection with PET: pharmacokinetic study in a rat model of chronic MI.

    Science.gov (United States)

    Kim, Heejung; Lee, Sung-Jin; Davies-Venn, Cynthia; Kim, Jin Su; Yang, Bo Yeun; Yao, Zhengsheng; Kim, Insook; Paik, Chang H; Bluemke, David A

    2016-02-01

    The aim of this study was to investigate the pharmacokinetics of (64)Cu-DOTA (1,4,7,10-azacyclododecane-N,N',N'',N'''-tetraacetic acid), a positron surrogate analog of the late gadolinium (Gd)-enhancement cardiac magnetic resonance agent, Gd-DOTA, in a rat model of chronic myocardial infarction (MI) and its microdistribution in the cardiac fibrosis by autoradiography. DOTA was labeled with (64)Cu-acetate. CD rats (n=5) with MI by left anterior descending coronary artery ligation and normal rats (n=6) were injected intravenously with (64)Cu-DOTA (18.5 MBq, 0.02 mmol DOTA/kg). Dynamic PET imaging was performed for 60 min after injection. (18)F-Fluorodeoxyglucose ([(18)F]-FDG) PET imaging was performed to identify the viable myocardium. For the region of interest analysis, the (64)Cu-DOTA PET image was coregistered to the [(18)F]-FDG PET image. To validate the PET images, slices of heart samples from the base to the apex were analyzed using autoradiography and by histological staining with Masson's trichrome. (64)Cu-DOTA was rapidly taken up in the infarct area. The time-activity curves demonstrated that (64)Cu-DOTA concentrations in the blood, fibrotic tissue, and perfusion-rich organs peaked within a minute post injection; thereafter, it was rapidly washed out in parallel with blood clearance and excreted through the renal system. The blood clearance curve was biphasic, with a distribution half-life of less than 3 min and an elimination half-life of ∼21.8 min. The elimination half-life of (64)Cu-DOTA from the focal fibrotic tissue (∼22.4 min) and the remote myocardium (∼20.1 min) was similar to the blood elimination half-life. Consequently, the uptake ratios of focal fibrosis-to-blood and remote myocardium-to-blood remained stable for the time period between 10 and 60 min. The corresponding ratios obtained from images acquired from 30 to 60 min were 1.09 and 0.59, respectively, indicating that the concentration of (64)Cu-DOTA in the focal

  19. Drilling Automation Tests At A Lunar/Mars Analog Site

    Science.gov (United States)

    Glass, B.; Cannon, H.; Hanagud, S.; Lee, P.; Paulsen, G.

    2006-01-01

    Future in-situ lunar/martian resource utilization and characterization, as well as the scientific search for life on Mars, will require access to the subsurface and hence drilling. Drilling on Earth is hard - an art form more than an engineering discipline. The limited mass, energy and manpower in planetary drilling situations makes application of terrestrial drilling techniques problematic. The Drilling Automation for Mars Exploration (DAME) project is developing drilling automation and robotics for projected use in missions to the Moon and Mars in the 2011-15 period. This has been tested recently, drilling in permafrost at a lunar/martian analog site (Haughton Crater, Devon Island, Canada).

  20. Gas cluster ion beam for the characterization of organic materials in submarine basalts as Mars analogs

    International Nuclear Information System (INIS)

    Sano, Naoko; Barlow, Anders J.; Cumpson, Peter J.; Purvis, Graham W. H.; Abbott, Geoffrey D.; Gray, Neil N. D.

    2016-01-01

    The solar system contains large quantities of organic compounds that can form complex molecular structures. The processing of organic compounds by biological systems leads to molecules with distinctive structural characteristics; thus, the detection and characterization of organic materials could lead to a high degree of confidence in the existence of extra-terrestrial life. Given the nature of the surface of most planetary bodies in the solar system, evidence of life is more likely to be found in the subsurface where conditions are more hospitable. Basalt is a common rock throughout the solar system and the primary rock type on Mars and Earth. Basalt is therefore a rock type that subsurface life might exploit and as such a suitable material for the study of methods required to detect and analyze organic material in rock. Telluric basalts from Earth represent an analog for extra-terrestrial rocks where the indigenous organic matter could be analyzed for molecular biosignatures. This study focuses on organic matter in the basalt with the use of surface analysis techniques utilizing Ar gas cluster ion beams (GCIB); time of flight secondary ion mass spectrometry (ToF-SIMS), and x-ray photoelectron spectroscopy (XPS), to characterize organic molecules. Tetramethylammonium hydroxide (TMAH) thermochemolysis was also used to support the data obtained using the surface analysis techniques. The authors demonstrate that organic molecules were found to be heterogeneously distributed within rock textures. A positive correlation was observed to exist between the presence of microtubule textures in the basalt and the organic compounds detected. From the results herein, the authors propose that ToF-SIMS with an Ar GCIB is effective at detecting organic materials in such geological samples, and ToF-SIMS combined with XPS and TMAH thermochemolysis may be a useful approach in the study of extra-terrestrial organic material and life.

  1. Gas cluster ion beam for the characterization of organic materials in submarine basalts as Mars analogs

    Energy Technology Data Exchange (ETDEWEB)

    Sano, Naoko, E-mail: naoko.sano@ncl.ac.uk; Barlow, Anders J.; Cumpson, Peter J. [National EPSRC XPS Users' Service (NEXUS), School of Mechanical and Systems Engineering, Stephenson Building, Newcastle University, Newcastle-upon-Tyne NE1 7RU (United Kingdom); Purvis, Graham W. H.; Abbott, Geoffrey D.; Gray, Neil N. D. [School of Civil Engineering and Geosciences, Devonshire Building, Newcastle University, Newcastle-upon-Tyne NE1 7RU (United Kingdom)

    2016-07-15

    The solar system contains large quantities of organic compounds that can form complex molecular structures. The processing of organic compounds by biological systems leads to molecules with distinctive structural characteristics; thus, the detection and characterization of organic materials could lead to a high degree of confidence in the existence of extra-terrestrial life. Given the nature of the surface of most planetary bodies in the solar system, evidence of life is more likely to be found in the subsurface where conditions are more hospitable. Basalt is a common rock throughout the solar system and the primary rock type on Mars and Earth. Basalt is therefore a rock type that subsurface life might exploit and as such a suitable material for the study of methods required to detect and analyze organic material in rock. Telluric basalts from Earth represent an analog for extra-terrestrial rocks where the indigenous organic matter could be analyzed for molecular biosignatures. This study focuses on organic matter in the basalt with the use of surface analysis techniques utilizing Ar gas cluster ion beams (GCIB); time of flight secondary ion mass spectrometry (ToF-SIMS), and x-ray photoelectron spectroscopy (XPS), to characterize organic molecules. Tetramethylammonium hydroxide (TMAH) thermochemolysis was also used to support the data obtained using the surface analysis techniques. The authors demonstrate that organic molecules were found to be heterogeneously distributed within rock textures. A positive correlation was observed to exist between the presence of microtubule textures in the basalt and the organic compounds detected. From the results herein, the authors propose that ToF-SIMS with an Ar GCIB is effective at detecting organic materials in such geological samples, and ToF-SIMS combined with XPS and TMAH thermochemolysis may be a useful approach in the study of extra-terrestrial organic material and life.

  2. Tidally Heated Terrestrial Exoplanets

    Science.gov (United States)

    Henning, Wade Garrett

    This work models the surface and internal temperatures for hypothetical terrestrial planets in situations involving extreme tidal heating. The feasibility of such planets is evaluated in terms of the orbital perturbations that may give rise to them, their required proximity to a hoststar, and the potential for the input tidal heating to cause significant partial melting of the mantle. Trapping terrestrial planets into 2:1 resonances with migrating Hot Jupiters is considered as a reasonable way for Earth-like worlds to both maintain high eccentricities and to move to short enough orbital periods (1-20 days) for extreme tidal heating to occur. Secular resonance and secular orbital perturbations may support moderate tidal heating at a low equilibrium eccentricity. At orbital periods below 10-30 days, with eccentricities from 0.01 to 0.1, tidal heat may greatly exceed radiogenic heat production. It is unlikely to exceed insolation, except when orbiting very low luminosity hosts, and thus will have limited surface temperature expression. Observations of such bodies many not be able to detect tidal surface enhancements given a few percent uncertainty in albedo, except on the nightside of spin synchronous airless objects. Otherwise detection may occur via spectral detection of hotspots or high volcanic gas concentrations including sulfur dioxide and hydrogen sulfide. The most extreme cases may be able to produce magma oceans, or magma slush mantles with up to 40-60% melt fractions. Tides may alter the habitable zones for smaller red dwarf stars, but are generally detrimental. Multiple viscoelastic models, including the Maxwell, Voigt-Kelvin, Standard Anelastic Solid, and Burgers rheologies are explored and applied to objects such as Io and the super-Earth planet GJ 876d. The complex valued Love number for the Burgers rheology is derived and found to be a useful improvement when modeling the low temperature behavior of tidal bodies, particularly during low eccentricity

  3. Enhanced Input of Terrestrial Particulate Organic Matter Reduces the Resilience of the Clear-Water State of Shallow Lakes: A Model Study

    NARCIS (Netherlands)

    Lischke, B.; Hilt, S.; Janse, J.H.; Kuiper, J.J.; Mehner, T.; Mooij, W.M.; Gaedke, U.

    2014-01-01

    The amount of terrestrial particulate organic matter (t-POM) entering lakes is predicted to increase as a result of climate change. This may especially alter the structure and functioning of ecosystems in small, shallow lakes which can rapidly shift from a clear-water, macrophyte-dominated into a

  4. The use of the multivariate Principal Response Curve (PRC) for community analysis: a case study on the effects of carbendazim on enchytraeids in Terrestrial Model Ecosystems (TME).

    NARCIS (Netherlands)

    Moser, T.; Römbke, J.; Schallnass, H.-J.; van Gestel, C.A.M.

    2007-01-01

    The effects of the fungicide carbendazim (formulation Derosal®) on enchytraeids were determined in Terrestrial Model Ecosystem (TME) tests. TMEs consisted of intact soil columns (diameter 17.5 cm; length 40 cm) taken from three grassland sites (Amsterdam (The Netherlands), Bangor (Wales, England)

  5. Two analogy strategies: the cases of mind metaphors and introspection

    Science.gov (United States)

    Fischer, Eugen

    2018-04-01

    Analogical reasoning is often employed in problem-solving and metaphor interpretation. This paper submits that, as a default, analogical reasoning addressing these different tasks employs different mapping strategies. In problem-solving, it employs analogy-maximising strategies (like structure mapping, Gentner, D., & Markman, A. B. (1997). Structure mapping in analogy and similarity. American Psychologist, 52, 45-56); in metaphor interpretation, analogy-minimising strategies (like ATT-Meta, Barnden, J. A. (2015). Open-ended elaborations in creative metaphor. In T. R. Besold, M. Schorlemmer, & A. Smaill (Eds.), Computational creativity research: Towards creative machines (pp. 217-242). Berlin: Springer). The two strategies interact in analogical reasoning with conceptual metaphors. This interaction leads to predictable fallacies. The paper supports these hypotheses through case-studies on "mind" metaphors from ordinary discourse, and abstract problem-solving in the philosophy of mind, respectively. It shows that (1) default metaphorical interpretations for vision- and space-cognition metaphors can be derived with a variant of the analogy-minimising ATT-Meta approach, (2) philosophically influential introspective conceptions of the mind can be derived with conceptual metaphors only through an analogy-maximising strategy, and (3) the interaction of these strategies leads to hitherto unrecognised fallacies in analogical reasoning with metaphors. This yields a debunking explanation of introspective conceptions.

  6. Ecological transfer mechanisms - Terrestrial

    International Nuclear Information System (INIS)

    Martin, W.E.; Raines, Gilbert E.; Bloom, S.G.; Levin, A.A.

    1969-01-01

    Radionuclides produced by nuclear excavation detonations and released to the environment may enter a variety of biogeochemical cycles and follow essentially the same transfer pathways as their stable-element counterparts. Estimation of potential internal radiation doses to individuals and/or populations living in or near fallout-contaminated areas requires analysis of the food-chain and other ecological pathways by which radionuclides released to the environment may be returned to man. A generalized materials transfer diagram, applicable to the forest, agricultural, freshwater and marine ecosystems providing food and water to the indigenous population of Panama and Colombia in regions that could be affected by nuclear excavation of a sea-level canal between the Atlantic and Pacific Oceans, is presented. Transfer mechanisms effecting the movement of stable elements and radionuclides in terrestrial ecosystems are discussed, and methods used to simulate these processes by means of mathematical models are described to show how intake values are calculated for different radionuclides in the major ecological pathways leading to man. These data provide a basis for estimating potential internal radiation doses for comparison with the radiation protection criteria established by recognized authorities; and this, in turn, provides a basis for recommending measures to insure the radiological safety of the nuclear operation plan. (author)

  7. Solar-terrestrial physics

    International Nuclear Information System (INIS)

    Patel, V.L.

    1977-01-01

    The Glossary is designed to be a technical dictionary that will provide solar workers of various specialties, students, other astronomers and theoreticians with concise information on the nature and the properties of phenomena of solar and solar-terrestrial physics. Each term, or group of related terms, is given a concise phenomenological and quantitative description, including the relationship to other phenomena and an interpretation in terms of physical processes. The references are intended to lead the non-specialist reader into the literature. This section deals with: geomagnetic field; coordinate systems; geomagnetic indices; Dst index; auroral electrojet index AE; daily, 27-day and semi-annual variations of geomagnetic field; micropulsation; geomagnetic storms; storm sudden commencement (SSC) or sudden commencement (SC); initial phase; ring current; sudden impulses; ionosphere; D region; polar cap absorption; sudden ionospheric disturbance; E region; sporadic E; equatorial electrojet; solar flare effect; F 1 and F 2 regions; spread F; travelling ionospheric disturbances; magnetosphere; magnetospheric coordinate systems; plasmasphere; magnetosheath; magnetospheric tail; substorm; radiation belts or Van Allen belts; whistlers; VLF emissions; aurora; auroral forms; auroral oval and auroral zones; auroral intensity; stable auroral red arcs; pulsing aurora; polar glow aurora; and airglow. (B.R.H.)

  8. Ecological transfer mechanisms - Terrestrial

    Energy Technology Data Exchange (ETDEWEB)

    Martin, W E; Raines, Gilbert E; Bloom, S G; Levin, A A [Battelle Memorial Institute, CoIumbus, OH (United States)

    1969-07-01

    Radionuclides produced by nuclear excavation detonations and released to the environment may enter a variety of biogeochemical cycles and follow essentially the same transfer pathways as their stable-element counterparts. Estimation of potential internal radiation doses to individuals and/or populations living in or near fallout-contaminated areas requires analysis of the food-chain and other ecological pathways by which radionuclides released to the environment may be returned to man. A generalized materials transfer diagram, applicable to the forest, agricultural, freshwater and marine ecosystems providing food and water to the indigenous population of Panama and Colombia in regions that could be affected by nuclear excavation of a sea-level canal between the Atlantic and Pacific Oceans, is presented. Transfer mechanisms effecting the movement of stable elements and radionuclides in terrestrial ecosystems are discussed, and methods used to simulate these processes by means of mathematical models are described to show how intake values are calculated for different radionuclides in the major ecological pathways leading to man. These data provide a basis for estimating potential internal radiation doses for comparison with the radiation protection criteria established by recognized authorities; and this, in turn, provides a basis for recommending measures to insure the radiological safety of the nuclear operation plan. (author)

  9. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2014-01-01

    Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehensively, linearization issues and measurement methods for the characterization of advanced analog filters are introduced in addition. Numerous elaborate illustrations promote an easy comprehension. This book will be of value to engineers and researchers in industry as well as scientists and Ph.D students at universities. The book is also recommendable to graduate students specializing on nanoelectronics, microelectronics ...

  10. Applications of landscape genetics to connectivity research in terrestrial animals [Chapter 12

    Science.gov (United States)

    Lisette P. Waits; Samuel A. Cushman; Steve F. Spear

    2016-01-01

    Landscape genetic studies have focused on terrestrial animals more than any other taxonomic group. This chapter focuses on applications of landscape genetics for understanding connectivity of terrestrial animal populations. It starts with a general introduction covering unique characteristics and challenges of the terrestrial study system. This is followed by...

  11. Aquatic and Terrestrial Environment 2004

    DEFF Research Database (Denmark)

    Andersen, J. M.; Boutrup, S.; Bijl, L. van der

    This report presents the 2004 results of the Danish National Monitoring and Assess-ment Programme for the Aquatic and Terrestrial Environments (NOVANA). 2004 was the first year in which terrestrial nature was included in the monitoring pro-gramme. The report reviews the state of the groundwater......, watercourses, lakes and marine waters and the pressures upon them and reviews the monitoring of terrestrial natural habitats and selected plants and animals. The report is based on the annual reports prepared for each subprogramme by the Topic Centres. The latter reports are mainly based on data collected...

  12. Tribulus terrestris Extract Improves Human Sperm Parameters In Vitro

    Science.gov (United States)

    Khaleghi, Sara; Bakhtiari, Mitra; Asadmobini, Atefeh; Esmaeili, Farzane

    2016-01-01

    Objective. The object of present study was to investigate the effects of direct addition of Tribulus terrestris extract on human sperm parameters. Design. Semen specimens from 40 healthy men volunteers were divided into 4 groups: one group received no treatment (control group) while the others were incubated with 20, 40, and 50 µg/mL of T terrestris extract (experimental groups). Motility, viability, and DNA fragmentation were assessed in all groups. Results. The incubation of human semen with 40 and 50 μg/mL of T terrestris extract significantly enhanced total sperm motility, number of progressive motile spermatozoa, and curvilinear velocity over 60 to 120 minutes’ holding time (P terrestris extract (P terrestris extract to human sperm could affect male fertility capacity. PMID:27694560

  13. Tribulus terrestris Extract Improves Human Sperm Parameters In Vitro.

    Science.gov (United States)

    Khaleghi, Sara; Bakhtiari, Mitra; Asadmobini, Atefeh; Esmaeili, Farzane

    2016-09-30

    The object of present study was to investigate the effects of direct addition of Tribulus terrestris extract on human sperm parameters. Semen specimens from 40 healthy men volunteers were divided into 4 groups: one group received no treatment (control group) while the others were incubated with 20, 40, and 50 µg/mL of T terrestris extract (experimental groups). Motility, viability, and DNA fragmentation were assessed in all groups. The incubation of human semen with 40 and 50 μg/mL of T terrestris extract significantly enhanced total sperm motility, number of progressive motile spermatozoa, and curvilinear velocity over 60 to 120 minutes' holding time (P terrestris extract (P terrestris extract to human sperm could affect male fertility capacity. © The Author(s) 2016.

  14. Young Children's Analogical Problem Solving: Gaining Insights from Video Displays

    Science.gov (United States)

    Chen, Zhe; Siegler, Robert S.

    2013-01-01

    This study examined how toddlers gain insights from source video displays and use the insights to solve analogous problems. Two- to 2.5-year-olds viewed a source video illustrating a problem-solving strategy and then attempted to solve analogous problems. Older but not younger toddlers extracted the problem-solving strategy depicted in the video…

  15. The interplay of conflict and analogy in multidisciplinary teams.

    Science.gov (United States)

    Paletz, Susannah B F; Schunn, Christian D; Kim, Kevin H

    2013-01-01

    Creative teamwork in multidisciplinary teams is a topic of interest to cognitive psychologists on the one hand, and to both social and organizational psychologists on the other. However, the interconnections between cognitive and social layers have been rarely explored. Drawing on mental models and dissonance theories, the current study takes a central variable studied by cognitive psychologists-analogy-and examines its relationship to a central variable examined by social psychologists-conflict. In an observational, field study, over 11h of audio-video data from conversations of the Mars Exploration Rover scientists were coded for different types of analogy and micro-conflicts that reveal the character of underlying psychological mechanisms. Two different types of time-lagged logistic models applied to these data revealed asymmetric patterns of associations between analogy and conflict. Within-domain analogies, but not within-discipline or outside-discipline analogies, preceded science and work process conflicts, suggesting that in multidisciplinary teams, representational gaps in very close domains will be more likely to spark conflict. But analogies also occurred in reaction to conflict: Process and negative conflicts, but not task conflicts, preceded within-discipline analogies, but not to within-domain or outside-discipline analogies. This study demonstrates ways in which cognition can be bidirectionally tied to social processes and discourse. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Young Children's Analogical Reasoning: The Role of Immediate Feedback

    Science.gov (United States)

    Chiu, Shuhui; Alexander, Patricia A.

    2014-01-01

    In this study, a computerized measure, Interactive Analogical Measure (IAM), was developed and used to assess young children's ability to reason analogically. The IAM was equipped to provide corrective feedback and the effects of that feedback were tested for experimental and control groups. A group of 5-year-olds (N = 80) participated in the…

  17. Analysis of Attention and Analogical Reasoning in Children of Poverty

    Science.gov (United States)

    Weatherholt, Tara N.; Harris, Ruby C.; Burns, Barbara M.; Clement, Catherine

    2006-01-01

    This study examined the relationship between specific attentional aspects of processing capacity and analogical reasoning in children from low-income families. 77 children aged 48-77 (M = 56.7) months were assessed on an analogical reasoning task (matrices subtest of the Kaufman Brief Intelligence Test) and on computerized attention tasks designed…

  18. Some aspects of analogical reasoning in mathematical creativity

    OpenAIRE

    Pease, Alison; Guhe, Markus; Smaill, Alan

    2010-01-01

    Analogical reasoning can shed light on both of the two key processes of creativity– generation and evaluation. Hence, it is a powerful tool for creativity. We illustrate this with three historical case studies of creative mathematical conjectures which were either found or evaluated via analogies. We conclude by describing our ongoing efforts to build computational realisations of these ideas.

  19. SSERVI Analog Regolith Simulant Testbed Facility

    Science.gov (United States)

    Minafra, J.; Schmidt, G. K.

    2016-12-01

    SSERVI's goals include supporting planetary researchers within NASA, other government agencies; private sector and hardware developers; competitors in focused prize design competitions; and academic sector researchers. The SSERVI Analog Regolith Simulant Testbed provides opportunities for research scientists and engineers to study the effects of regolith analog testbed research in the planetary exploration field. This capability is essential to help to understand the basic effects of continued long-term exposure to a simulated analog test environment. The current facility houses approximately eight tons of JSC-1A lunar regolith simulant in a test bin consisting of a 4 meter by 4 meter area. SSERVI provides a bridge between several groups, joining together researchers from: 1) scientific and exploration communities, 2) multiple disciplines across a wide range of planetary sciences, and 3) domestic and international communities and partnerships. This testbed provides a means of consolidating the tasks of acquisition, storage and safety mitigation in handling large quantities of regolith simulant Facility hardware and environment testing scenarios include, but are not limited to the following; Lunar surface mobility, Dust exposure and mitigation, Regolith handling and excavation, Solar-like illumination, Lunar surface compaction profile, Lofted dust, Mechanical properties of lunar regolith, and Surface features (i.e. grades and rocks) Numerous benefits vary from easy access to a controlled analog regolith simulant testbed, and planetary exploration activities at NASA Research Park, to academia and expanded commercial opportunities in California's Silicon Valley, as well as public outreach and education opportunities.

  20. Insulin analogs with improved pharmacokinetic profiles.

    Science.gov (United States)

    Brange; Vølund

    1999-02-01

    The aim of insulin replacement therapy is to normalize blood glucose in order to reduce the complications of diabetes. The pharmacokinetics of the traditional insulin preparations, however, do not match the profiles of physiological insulin secretion. The introduction of the rDNA technology 20 years ago opened new ways to create insulin analogs with altered properties. Fast-acting analogs are based on the idea that an insulin with less tendency to self-association than human insulin would be more readily absorbed into the systemic circulation. Protracted-acting analogs have been created to mimic the slow, steady rate of insulin secretion in the fasting state. The present paper provides a historical review of the efforts to change the physicochemical and pharmacological properties of insulin in order to improve insulin therapy. The available clinical studies of the new insulins are surveyed and show, together with modeling results, that new strategies for optimal basal-bolus treatment are required for utilization of the new fast-acting analogs.

  1. Osilodrostat (LCI699), a potent 11β-hydroxylase inhibitor, administered in combination with the multireceptor-targeted somatostatin analog pasireotide: A 13-week study in rats

    Energy Technology Data Exchange (ETDEWEB)

    Li, Li, E-mail: li1.li@novartis.com [Preclinical Safety, Novartis Institutes for BioMedical Research, East Hanover, NJ (United States); Vashisht, Kapil; Boisclair, Julie [Preclinical Safety, Novartis Institutes for BioMedical Research, East Hanover, NJ (United States); Li, Wenkui; Lin, Tsu-han [Drug Metabolism and Pharmacokinetics, Novartis Institutes for BioMedical Research, East Hanover, NJ (United States); Schmid, Herbert A. [Novartis Oncology Development, Basel (Switzerland); Kluwe, William; Schoenfeld, Heidi; Hoffmann, Peter [Preclinical Safety, Novartis Institutes for BioMedical Research, East Hanover, NJ (United States)

    2015-08-01

    The somatostatin analog pasireotide and the 11β-hydroxylase inhibitor osilodrostat (LCI699) reduce cortisol levels by distinct mechanisms of action. There exists a scientific rationale to investigate the clinical efficacy of these two agents in combination. This manuscript reports the results of a toxicology study in rats, evaluating different doses of osilodrostat and pasireotide alone and in combination. Sixty male and 60 female rats were randomized into single-sex groups to receive daily doses of pasireotide (0.3 mg/kg/day, subcutaneously), osilodrostat (20 mg/kg/day, orally), osilodrostat/pasireotide in combination (low dose, 1.5/0.03 mg/kg/day; mid-dose, 5/0.1 mg/kg/day; or high dose, 20/0.3 mg/kg/day), or vehicle for 13 weeks. Mean body-weight gains from baseline to Week 13 were significantly lower in the pasireotide-alone and combined-treatment groups compared to controls, and were significantly higher in female rats receiving osilodrostat monotherapy. Osilodrostat and pasireotide monotherapies were associated with significant changes in the histology and mean weights of the pituitary and adrenal glands, liver, and ovary/oviduct. Osilodrostat alone was associated with adrenocortical hypertrophy and hepatocellular hypertrophy. In combination, osilodrostat/pasireotide did not exacerbate any target organ changes and ameliorated the liver and adrenal gland changes observed with monotherapy. C{sub max} and AUC{sub 0–24h} of osilodrostat and pasireotide increased in an approximately dose-proportional manner. In conclusion, the pasireotide and osilodrostat combination did not exacerbate changes in target organ weight or toxicity compared with either monotherapy, and had an acceptable safety profile; addition of pasireotide to the osilodrostat regimen may attenuate potential adrenal gland hyperactivation and hepatocellular hypertrophy, which are potential side effects of osilodrostat monotherapy. - Highlights: • We examined the target organ toxicity of SOM230

  2. Biogeochemical Indicators in High- and Low-Arctic Marine and Terrestrial Avian Community Changes: Comparative Isotopic (13C, 15N, and 34S) Studies in Alaska and Greenland

    Science.gov (United States)

    Causey, D.; Bargmann, N. A.; Burnham, K. K.; Burnham, J. L.; Padula, V. M.; Johnson, J. A.; Welker, J. M.

    2011-12-01

    Understanding the complex dynamics of environmental change in northern latitudes is of paramount importance today, given documented rapid shifts in sea ice, plant phenology, temperatures, deglaciation, and habitat fidelity. This knowledge is particularly critical for Arctic avian communities, which are integral components by which biological teleconnections are maintained between the mid and northern latitudes. Furthermore, Arctic birds are fundamental to Native subsistence lifestyles and a focus for conservation activities. Avian communities of marine and terrestrial Arctic environments represent a broad spectrum of trophic levels, from herbivores (eg., geese Chen spp.), planktivores (eg., auklets Aethia spp.), and insectivores (eg., passerines: Wheatears Oenanthe spp., Longspurs Calcarius spp.), to predators of marine invertebrates (eg., eiders Somateria spp.), nearshore and offshore fish (eg., cormorants Phalacrocorax spp, puffins Fratercula spp.), even other bird species (eg., gulls Larus spp., falcons Peregrinus spp.). This diversity of trophic interconnections is an integral factor in the dynamics of Arctic ecosystem ecology, and they are key indicators for the strength and trajectories of change. We are especially interested in their feeding ecology, using stable isotope-diet relations to examine historical diets and to predict future feeding ecology by this range of species. Since 2009, we have been studying the foodweb ecology using stable isotopes (δ13C, δ15N, δ34S) of contemporaneous coastal and marine bird communities in High Arctic (Northwest Greenland) and Low Arctic (western Aleutian Islands, AK). We are quantifying the isotopic values of blood, organ tissues, and feathers, and have carried out comparisons between native and lipid-extracted samples. Although geographically distant, these communities comprise similar taxonomic and ecological congeners, including several species common to both (eg., Common Eider, Black-legged Kittiwake, Northern

  3. A Study of the Abundance and 13C/12C Ratio of Atmospheric Carbon Dioxide to Advance the Scientific Understanding of Terrestrial Processes Regulating the Global Carbon Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Stephen C. Piper

    2005-10-15

    The primary goal of our research program, consistent with the goals of the U.S. Climate Change Science Program and funded by the terrestrial carbon processes (TCP) program of DOE, has been to improve understanding of changes in the distribution and cycling of carbon among the active land, ocean and atmosphere reservoirs, with particular emphasis on terrestrial ecosystems. Our approach is to systematically measure atmospheric CO2 to produce time series data essential to reveal temporal and spatial patterns. Additional measurements of the 13C/12C isotopic ratio of CO2 provide a basis for distinguishing organic and inorganic processes. To pursue the significance of these patterns further, our research also involved interpretations of the observations by models, measurements of inorganic carbon in sea water, and of CO2 in air near growing land plants.

  4. TERRESTRIAL PLANET FORMATION FROM AN ANNULUS

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Kevin J.; Levison, Harold F., E-mail: kwalsh@boulder.swri.edu [Southwest Research Institute, 1050 Walnut St. Suite 300, Boulder, CO 80302 (United States)

    2016-09-01

    It has been shown that some aspects of the terrestrial planets can be explained, particularly the Earth/Mars mass ratio, when they form from a truncated disk with an outer edge near 1.0 au. This has been previously modeled starting from an intermediate stage of growth utilizing pre-formed planetary embryos. We present simulations that were designed to test this idea by following the growth process from km-sized objects located between 0.7 and 1.0 au up to terrestrial planets. The simulations explore initial conditions where the solids in the disk are planetesimals with radii initially between 3 and 300 km, alternately including effects from a dissipating gaseous solar nebula and collisional fragmentation. We use a new Lagrangian code known as LIPAD, which is a particle-based code that models the fragmentation, accretion, and dynamical evolution of a large number of planetesimals, and can model the entire growth process from km-sizes up to planets. A suite of large (∼ Mars mass) planetary embryos is complete in only ∼1 Myr, containing most of the system mass. A quiescent period then persists for 10–20 Myr characterized by slow diffusion of the orbits and continued accretion of the remaining planetesimals. This is interrupted by an instability that leads to embryos crossing orbits and embryo–embryo impacts that eventually produce the final set of planets. While this evolution is different than that found in other works exploring an annulus, the final planetary systems are similar, with roughly the correct number of planets and good Mars-analogs.

  5. Fast multichannel analog storage system

    International Nuclear Information System (INIS)

    Freytag, D.R.

    1982-11-01

    A Multichannel Analog Storage System based on a commercial 32-channel parallel in/serial out (PISO) analog shift register is described. The basic unit is a single width CAMAC module containing 512 analog cells and the associated logic for data storage and subsequent readout. At sampling rates of up to 30 MHz the signals are strobed directly into the PISO. At higher rates signals are strobed into a fast presampling stage and subsequently transferred in block form into an array of PISO's. Sampling rates of 300 MHz have been achieved with the present device and 1000 MHz are possible with improved signal drivers. The system is well suited for simultaneous handling of many signal channels with moderate numbers of samples in each channel. RMS noise over full scale signal has been measured as 1:3000 (approx. = 11 bit). However, nonlinearities in the response and differences in sensitivity of the analog cells require an elaborate calibration system in order to realize 11 bit accuracy for the analog information

  6. Influence of multiple global change drivers on terrestrial carbon storage

    DEFF Research Database (Denmark)

    Yue, Kai; Fornara, Dario A; Yang, Wanqin

    2017-01-01

    The interactive effects of multiple global change drivers on terrestrial carbon (C) storage remain poorly understood. Here, we synthesise data from 633 published studies to show how the interactive effects of multiple drivers are generally additive (i.e. not differing from the sum of their indivi......The interactive effects of multiple global change drivers on terrestrial carbon (C) storage remain poorly understood. Here, we synthesise data from 633 published studies to show how the interactive effects of multiple drivers are generally additive (i.e. not differing from the sum...... additive effects of multiple global change drivers into future assessments of the C storage ability of terrestrial ecosystems....

  7. Licancabur Volcano, Bolivia and life in the Atacama: Environmental physics and analogies to Mars

    Science.gov (United States)

    Hock, Andrew Nelson

    Although there is no perfect environmental analog to Mars on Earth, quantitative study of relevant terrestrial field sites can serve as the basis for physical models and technology development to aid future exploration. This dissertation describes original field and laboratory research on two terrestrial analog sites: Licancabur Volcano, Bolivia, and the Atacama Desert, Chile. Atop Licancabur, at an elevation of nearly 6,000 meters above sea level, sits the highest volcanic lake on Earth. Prior to this work, little was known about the lake, its waters, the role of volcanism or its potential relationship to locales on Mars. In the first part of this work, I describe observations of the lake resulting from several years of field study, including data on meteorological conditions and solar irradiance. These and other measurements provide the basis for (1) the first quantitative mass and energy balance model of the lake, and (2) the first determination of the altitude effect on solar visible and ultraviolet flux from the high altitude summit. Under the observed conditions, model results indicate: lake waters are primarily meteoric in origin and evaporating rapidly; volcanic input is not required to explain observations of lake water temperature or year-end model results. Nearby, Chile's Atacama Desert is known to be one of the driest, most inhospitable environments on Earth. There, environmental similarities to Mars provide an apt testing ground for new astrobiological exploration technologies. In the latter part of this work, I present results from my work with the Life In The Atacama (LITA) Mars rover field experiment. In particular, I report on the development of a new data analysis tool named the LITA Data Scoring System (DSS). Subject to the user-defined constraints, the DSS was used to facilitate targeting, analysis and mapping of rover science results relevant to potential habitability and evidence for life at three desert field sites. Although experimental in

  8. Analogical reasoning and aging: the processing speed and inhibition hypothesis.

    Science.gov (United States)

    Bugaiska, Aurélia; Thibaut, Jean-Pierre

    2015-01-01

    This study was designed to investigate the effect of aging on analogical reasoning by manipulating the strength of semantic association (LowAssoc or HighAssoc) and the number of distracters' semantic analogies of the A:B::C:D type and to determine which factors might be responsible for the age-related differences on analogical reasoning by testing two different theoretical frameworks: the inhibition hypothesis and the speed mediation hypothesis. We compared young adults and two groups of aging people (old and old-old) with word analogies of the A:B::C:D format. Results indicate an age-related effect on analogical reasoning, this effect being greatest with LowAssoc analogies. It was not associated with the presence of semantic distractors. Moreover, the results show that the variance part of the analogy task due to age was mainly explained by processing speed (rather than by inhibition) in the case of old participants and by both processing speed and inhibition in the old-old group. These results are discussed in relation to current models of aging and their interaction with the processes involved in analogical reasoning.

  9. Analogy as a means of theoretical adoption of pedagogical disciplines

    Directory of Open Access Journals (Sweden)

    Solovcova Irina A.

    2006-01-01

    Full Text Available The paper considers an application of analogy in the initial-teacher training as a tool of approaching pedagogical disciplines. The author proposes a classification of pedagogical analogies which provides choices of the most efficient model for a specific didactic situation. The article clarifies the model of the theoretical approach to pedagogical disciplines through active use of analogy, which contributes to a higher efficiency in a teacher and student interaction. The model consists of three stages: training (the stage of acquiring analogy model, the analytical stage (acquisition of pedagogical concepts, phenomena and systems through the application of analogy, and the stage of self-realization (the application of analogy method in students’ scientific-research activities considering external and internal didactic conditions which transform analogy from a teaching method into a tool for the acquisition of pedagogical disciplines. The author demonstrates that the application of analogy has a positive effect not only on the acquisition of pedagogical knowledge (especially methodic and the development of heuristic skills in students, but also on motivation for the study of pedagogical disciplines (cognitive aspect and professional pedagogical activity (formation of an individual-pedagogical attitude. .

  10. Molecular interactions between (--epigallocatechin gallate analogs and pancreatic lipase.

    Directory of Open Access Journals (Sweden)

    Shihui Wang

    Full Text Available The molecular interactions between pancreatic lipase (PL and four tea polyphenols (EGCG analogs, like (--epigallocatechin gallate (EGCG, (--gallocatechin gallate (GCG, (--epicatechin gallate (ECG, and (--epigallocatechin (EC, were studied from PL activity, conformation, kinetics and thermodynamics. It was observed that EGCG analogs inhibited PL activity, and their inhibitory rates decreased by the order of EGCG>GCG>ECG>EC. PL activity at first decreased rapidly and then slowly with the increase of EGCG analogs concentrations. α-Helix content of PL secondary structure decreased dependent on EGCG analogs concentration by the order of EGCG>GCG>ECG>EC. EGCG, ECG, and EC could quench PL fluorescence both dynamically and statically, while GCG only quenched statically. EGCG analogs would induce PL self-assembly into complexes and the hydrodynamic radii of the complexes possessed a close relationship with the inhibitory rates. Kinetics analysis showed that EGCG analogs non-competitively inhibited PL activity and did not bind to PL catalytic site. DSC measurement revealed that EGCG analogs decreased the transition midpoint temperature of PL enzyme, suggesting that these compounds reduced PL enzyme thermostability. In vitro renaturation through urea solution indicated that interactions between PL and EGCG analogs were weak and non-covalent.

  11. Cyclopentanoid analogs of phosphatidylcholine: susceptibility to phospholipase A2.

    Science.gov (United States)

    Lister, M D; Hancock, A J

    1988-10-01

    Six isomers of dipalmitoylcyclopentanetriol phosphocholine (cyclopentano-lecithin) were tested as potential substrates for phospholipase A2. Since each of these analogs possesses a configuration that mimics a narrow range of conformations of a glycerophospholipid molecule, the analogs were used to assess the enzyme's conformational requirements. Studies showed that all of the analogs containing the phosphocholine at the C-1 (or C-3) position could be hydrolyzed, while only one of the three analogs that contains the polar head group at the C-2 position was susceptible. Kinetic studies, however, revealed that only the all-trans-(1,3/2-1P)-cyclopentano-lecithin gave initial rates of hydrolysis that were measurable by pH-stat. Acyl group specificity of the enzyme towards the all-trans isomer was determined with an analog was acyl groups were distinguishable. The synthesis of this mixed-acid-cyclopentano-PC is described herein. When this analog was enzymatically assayed, results unequivocally showed the enzyme to be specific for C-2 acyl hydrolysis. This specificity, and data showing that the all-trans analog is stereospecifically hydrolyzed, indicate that it is acted on in an analogous manner to dipalmitoylphosphatidylcholine. These studies indicate that although the configuration of the analog is not necessarily a prerequisite for hydrolysis, there does appear to be an optimal spatial orientation for enzymatic activity. The analogy between the susceptibilities of all-trans-(1,3/2-1P)-cyclopentano-lecithin and glycero-lecithin suggests that the conformation of the glycero-lecithin during phospholipase A2-mediated hydrolysis may be best simulated by the all-trans orientation of C-O bonds in the artificial substrate.

  12. The UF GEM Research Center Mobile Terrestrial Laser Scanner System M-TLSS Applied to Beach Morphology Studies in St. Augustine, Florida.

    Science.gov (United States)

    Fernandez, J. C.; Shrestha, R. L.; Carter, W. E.; Slatton, C. K.; Singhania, A.

    2006-12-01

    The UF GEM Research Center is working towards developing a Mobile Terrestrial Laser Scanning System (M- TLSS). The core of the M-TLSS is a commercial 2-axis ground based laser scanner, Optech ILRIS-36D, which is capable of generating XYZ with laser intensity or RGB textured point clouds in a range from 3m to 1500m. The laser operates at a wavelength of 1535 nm. The sample separation can be adjusted down to 0.00115°, and the scanning speed is 2,000 points per second. The scanner is integrated to a mobile telescoping, rotating and tilting platform which is essentially a telescopic lift mounted on the back of a pick up truck. This provides up to 6 degrees of freedom for performing scanning operations. A scanner built-in 6 megapixel digital camera and a digital video camera provide the M-TLSS moving and still imagining capability. The applications of the M-TLSS data sets are numerous in both the fields of science and engineering. This paper will focus on the application of M-TLSS as a complement to ALSM in the study of beach morphology in the St. Augustine, Florida area. ALSM data covers a long stretch of beach with a moderate sample density of approximately 1 laser return per square meter, which enables the detection of submeter-scale changes in shoreline position and dune heights over periods of few months. The M-TLSS, on the other hand, can provide high density point clouds (centimeter scale point spacing) of smaller areas known to be highly prone to erosion. From these point clouds centimeter level surface grids are created. These grids will be compared with the ALSM data and with a time series of M-TLSS data over the same area to provide high resolution, short term beach erosion monitoring. Surface morphological parameters that will be compared among the ALSM and M-TLSS data sets include shoreline position and gradients and standard deviations of elevations on cross- shore transects.

  13. Analog electronics for radiation detection

    CERN Document Server

    2016-01-01

    Analog Electronics for Radiation Detection showcases the latest advances in readout electronics for particle, or radiation, detectors. Featuring chapters written by international experts in their respective fields, this authoritative text: Defines the main design parameters of front-end circuitry developed in microelectronics technologies Explains the basis for the use of complementary metal oxide semiconductor (CMOS) image sensors for the detection of charged particles and other non-consumer applications Delivers an in-depth review of analog-to-digital converters (ADCs), evaluating the pros and cons of ADCs integrated at the pixel, column, and per-chip levels Describes incremental sigma delta ADCs, time-to-digital converter (TDC) architectures, and digital pulse-processing techniques complementary to analog processing Examines the fundamental parameters and front-end types associated with silicon photomultipliers used for single visible-light photon detection Discusses pixel sensors ...

  14. The fragmentation of Pangaea and Mesozoic terrestrial vertebrate biodiversity.

    Science.gov (United States)

    Vavrek, Matthew J

    2016-09-01

    During the Mesozoic (242-66 million years ago), terrestrial regions underwent a massive shift in their size, position and connectivity. At the beginning of the era, the land masses were joined into a single supercontinent called Pangaea. However, by the end of the Mesozoic, terrestrial regions had become highly fragmented, both owing to the drifting apart of the continental plates and the extremely high sea levels that flooded and divided many regions. How terrestrial biodiversity was affected by this fragmentation and large-scale flooding of the Earth's landmasses is uncertain. Based on a model using the species-area relationship (SAR), terrestrial vertebrate biodiversity would be expected to nearly double through the Mesozoic owing to continental fragmentation, despite a decrease of 24% in total terrestrial area. Previous studies of Mesozoic vertebrates have generally found increases in terrestrial diversity towards the end of the era, although these increases are often attributed to intrinsic or climatic factors. Instead, continental fragmentation over this time may largely explain any observed increase in terrestrial biodiversity. This study demonstrates the importance that non-intrinsic effects can have on the taxonomic success of a group, and the importance of geography to understanding past biodiversity. © 2016 The Author(s).

  15. Synthetic Analogs of Phospholipid Metabolites as Antimalarials.

    Science.gov (United States)

    1979-07-01

    phosphatidic acid analogs containing ether and phosphonate groups; completely non- hydrolyzable lecithin analogs containing phosphinate and ether groups...substance is a completely non- hydrolyzable analog of lecithin containing ether and phosphonate moieties instead of the normally labile carboxylic and...and also ant-i-phospholipase C (clostridial enzyme) activity. This substance Is a completely non- hydrolyzable analog of lecithin containing ether

  16. Effect factors for terrestrial acidification in Brazil

    DEFF Research Database (Denmark)

    Crespo Mendes, Natalia; Laurent, Alexis; Hauschild, Michael Zwicky

    conditions, which is an essential approach considering countries like Brazil, with high biodiversity. Previous studies have assessed the impacts of terrestrial acidification from the estimations of the potential losses of vascular plants species richness as a result of exposure to acidifying substances...... for 13 biomes, with 2409 species addressed for whole world. In this context this work aims to provide spatially-differentiated effect factors (EF) for terrestrial acidification in Brazil and support the development of spatially-differentiated characterization factors for Brazil. In order to maintain...... in Brazil, represented by 33167 species, indicating that this is a comprehensive study. Maps of soil pH in Brazil were extracted at 1-km resolution and pH values were extracted for the depth range of 0-30cm. For each ecoregion, species richness was plotted against soil pH and the exposure-response curves...

  17. Reconstitution of FMN-free NADPH-cytochrome P-450 reductase with a phosphorothioate analog of FMN: 31P NMR studies of the reconstituted protein

    International Nuclear Information System (INIS)

    Krum, D.P.; Otvos, J.D.; Calhoun, J.P.; Miziorko, H.M.; Masters, B.S.S.

    1987-01-01

    A phosphorothioate analog of FMN (FMNS) has been synthesized and shown to be completely competent in reconstituting the FMN-free form of NADPH-cytochrome P-450 reductase as evidenced by flavin determinations and cytochrome c reductase activity assays. The FMNS-reconstituted FMN-free reductase gives rise to an air-stable semiquinone, and the fluorescence of FMNS is quenched upon addition of FMN-free reductase. 31 P NMR spectra of the FMN-free reductase reveal only two resonances (-7.3 and -11.3 ppm), which are attributable to FAD. This result confirms the assignments of Otvos et al, and demonstrates unequivocally that there are no phosphate residues other than those of FMN and FAD attached to the steapsin-solubilized reductase. The addition of FMN to the FMN-free reductase resulted in the appearance of one additional resonance at 3.9 ppm. Addition of FMNS to the FMN-free reductase caused no change, surprisingly, in the 31 P NMR spectrum until Mn(II) was added, after which a peak centered at ∼ 45 ppm was observed. This unexpected result may be explained if the T 1 for the phosphate of FMNS is significantly longer than that of FMN, and suggests that the sulfur atom of FMNS may perturb the interaction of the phosphate with its protein environment. These results demonstrate the utility of phosphorothioate analogs as mechanistic probes for proteins containing nucleotide cofactors

  18. Study of the National Science Foundation's South Pole Station as an analogous data base for the logistical support of a Moon laboratory

    Science.gov (United States)

    Hickam, H. H., Jr.

    1993-01-01

    The day will come when the United States will want to return to the Earth's Moon. When that occurs, NASA may look to the Apollo program for technical and inspirational guidance. The Apollo program, however, was designed to be an end to itself--the landing of a man on the Moon and his return safely within the decade of the 1960's. When that was accomplished, the program folded because it was not self-sustaining. The next time we return to the Moon, we should base our planning on a program that is designed to be a sustained effort for an indefinite period. It is the thrust of this report that the South Pole Station of the National Science Foundation can be used to develop analogs for the construction, funding, and logistical support of a lunar base. Other analogs include transportation and national efforts versus international cooperation. A recommended lunar base using the South Pole Station as inspiration is provided, as well as details concerning economical construction of the base over a 22-year period.

  19. The Description of Problems Relating to Analogies Used in Science and Technology Textbooks

    Directory of Open Access Journals (Sweden)

    Rahmi YAĞBASAN

    2008-01-01

    Full Text Available The aim of this study was to determine the problems concerning the use of analogies ingeneral and analogies used in primary school science and technology lessons inparticular. In this study, descriptive method was used. 4th, 5th, and 8th classes Scienceand Technology course books; 7 th, 8 th classes Science Books were used as a source.Analogies in the course books were classified according to the literature and theproblems found related to the analogies are pointed out in the study. In this study itwas seen that eighty-nine analogies were used in Science and Technology and inScience course books. These analogies were used in descending order as 8, 4, 6, 7, 5class groups. Also it was seen that these analogies were generally at simple andpictorial analogies.

  20. Broad-Scale Comparison of Photosynthesis in Terrestrial and Aquatic Plant Communities

    DEFF Research Database (Denmark)

    Sand-Jensen, Kaj; Krause-Jensen, D.

    1997-01-01

    Comparisons of photosynthesis in terrestrial and aquatic habitats have been impaired by differences in methods and time-scales of measurements. We compiled information on gross photosynthesis at high irradiance and photosynthetic efficiency at low irradiance from 109 published terrestrial studies...... communities probably due to more efficient light utilization and gas exchange in the terrestrial habitats. By contrast only small differences were found within different aquatic plant communities or within different terrestrial plant communities....... of forests, grasslands and crops and 319 aquatic studies of phytoplankton, macrophyte and attached microalgal communities to test if specific differences existed between the communities. Maximum gross photosynthesis and photosynthetic efficiency were systematically higher in terrestrial than in aquatic...

  1. Heat Transfer Analogies

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, A

    1965-11-15

    This report contains descriptions of various analogues utilised to study different steady-state and unsteady-state heat transfer problems. The analogues covered are as follows: 1 . Hydraulic: a) water flow b) air flow 2. Membrane 3. Geometric Electrical: a) Electrolytic-tank b) Conducting sheet 4. Network; a) Resistance b) R-C A comparison of the different analogues is presented in the form of a table.

  2. Heat Transfer Analogies

    International Nuclear Information System (INIS)

    Bhattacharyya, A.

    1965-11-01

    This report contains descriptions of various analogues utilised to study different steady-state and unsteady-state heat transfer problems. The analogues covered are as follows: 1 . Hydraulic: a) water flow b) air flow 2. Membrane 3. Geometric Electrical: a) Electrolytic-tank b) Conducting sheet 4. Network; a) Resistance b) R-C A comparison of the different analogues is presented in the form of a table

  3. THE COMPOSITIONAL DIVERSITY OF EXTRASOLAR TERRESTRIAL PLANETS. II. MIGRATION SIMULATIONS

    International Nuclear Information System (INIS)

    Carter-Bond, Jade C.; O'Brien, David P.; Raymond, Sean N.

    2012-01-01

    Prior work has found that a variety of terrestrial planetary compositions are expected to occur within known extrasolar planetary systems. However, such studies ignored the effects of giant planet migration, which is thought to be very common in extrasolar systems. Here we present calculations of the compositions of terrestrial planets that formed in dynamical simulations incorporating varying degrees of giant planet migration. We used chemical equilibrium models of the solid material present in the disks of five known planetary host stars: the Sun, GJ 777, HD4203, HD19994, and HD213240. Giant planet migration has a strong effect on the compositions of simulated terrestrial planets as the migration results in large-scale mixing between terrestrial planet building blocks that condensed at a range of temperatures. This mixing acts to (1) increase the typical abundance of Mg-rich silicates in the terrestrial planets' feeding zones and thus increase the frequency of planets with Earth-like compositions compared with simulations with static giant planet orbits, and (2) drastically increase the efficiency of the delivery of hydrous phases (water and serpentine) to terrestrial planets and thus produce waterworlds and/or wet Earths. Our results demonstrate that although a wide variety of terrestrial planet compositions can still be produced, planets with Earth-like compositions should be common within extrasolar planetary systems.

  4. Mud Volcanoes - Analogs to Martian Cones and Domes (by the Thousands!)

    Science.gov (United States)

    Allen, Carlton C.; Oehler, Dorothy

    2010-01-01

    Mud volcanoes are mounds formed by low temperature slurries of gas, liquid, sediments and rock that erupt to the surface from depths of meters to kilometers. They are common on Earth, with estimates of thousands onshore and tens of thousands offshore. Mud volcanoes occur in basins with rapidly-deposited accumulations of fine-grained sediments. Such settings are ideal for concentration and preservation of organic materials, and mud volcanoes typically occur in sedimentary basins that are rich in organic biosignatures. Domes and cones, cited as possible mud volcanoes by previous authors, are common on the northern plains of Mars. Our analysis of selected regions in southern Acidalia Planitia has revealed over 18,000 such features, and we estimate that more than 40,000 occur across the area. These domes and cones strongly resemble terrestrial mud volcanoes in size, shape, morphology, associated flow structures and geologic setting. Geologic and mineralogic arguments rule out alternative formation mechanisms involving lava, ice and impacts. We are studying terrestrial mud volcanoes from onshore and submarine locations. The largest concentration of onshore features is in Azerbaijan, near the western edge of the Caspian Sea. These features are typically hundreds of meters to several kilometers in diameter, and tens to hundreds of meters in height. Satellite images show spatial densities of 20 to 40 eruptive centers per 1000 square km. Many of the features remain active, and fresh mud flows as long as several kilometers are common. A large field of submarine mud volcanoes is located in the Gulf of Cadiz, off the Atlantic coasts of Morocco and Spain. High-resolution sonar bathymetry reveals numerous km-scale mud volcanoes, hundreds of meters in height. Seismic profiles demonstrate that the mud erupts from depths of several hundred meters. These submarine mud volcanoes are the closest morphologic analogs yet found to the features in Acidalia Planitia. We are also conducting

  5. Multichannel analog temperature sensing system

    International Nuclear Information System (INIS)

    Gribble, R.

    1985-08-01

    A multichannel system that protects the numerous and costly water-cooled magnet coils on the translation section of the FRX-C/T magnetic fusion experiment is described. The system comprises a thermistor for each coil, a constant current circuit for each thermistor, and a multichannel analog-to-digital converter interfaced to the computer

  6. 49205 ANALOGE OG DIGITALE FILTRE

    DEFF Research Database (Denmark)

    Gaunholt, Hans

    1997-01-01

    Theese lecture notes treats the fundamental theory and the most commonly used design methods for passive- active and digital filters with special emphasis on microelectronic realizations. The lecture notes covers 75% of the material taught in the course 49205 Analog and Digital Filters...

  7. Drawing Analogies to Deepen Learning

    Science.gov (United States)

    Fava, Michelle

    2017-01-01

    This article offers examples of how drawing can facilitate thinking skills that promote analogical reasoning to enable deeper learning. The instructional design applies cognitive principles, briefly described here. The workshops were developed iteratively, through feedback from student and teacher participants. Elements of the UK National…

  8. Utilization of the terrestrial cyanobacteria

    Science.gov (United States)

    Katoh, Hiroshi; Tomita-Yokotani, Kaori; Furukawa, Jun; Kimura, Shunta; Yokoshima, Mika; Yamaguchi, Yuji; Takenaka, Hiroyuki

    The terrestrial, N _{2}-fixing cyanobacterium, Nostoc commune has expected to utilize for agriculture, food and terraforming cause of its extracellular polysaccharide, desiccation tolerance and nitrogen fixation. Previously, the first author indicated that desiccation related genes were analyzed and the suggested that the genes were related to nitrogen fixation and metabolisms. In this report, we suggest possibility of agriculture, using the cyanobacterium. Further, we also found radioactive compounds accumulated N. commune (cyanobacterium) in Fukushima, Japan after nuclear accident. Thus, it is investigated to decontaminate radioactive compounds from the surface soil by the cyanobacterium and showed to accumulate radioactive compounds using the cyanobacterium. We will discuss utilization of terrestrial cyanobacteria under closed environment. Keyword: Desiccation, terrestrial cyanobacteria, bioremediation, agriculture

  9. High resolution tomography using analog coding

    International Nuclear Information System (INIS)

    Brownell, G.L.; Burnham, C.A.; Chesler, D.A.

    1985-01-01

    As part of a 30-year program in the development of positron instrumentation, the authors have developed a high resolution bismuth germanate (BGO) ring tomography (PCR) employing 360 detectors and 90 photomultiplier tubes for one plane. The detectors are shaped as trapezoid and are 4 mm wide at the front end. When assembled, they form an essentially continuous cylindrical detector. Light from a scintillation in the detector is viewed through a cylindrical light pipe by the photomultiplier tubes. By use of an analog coding scheme, the detector emitting light is identified from the phototube signals. In effect, each phototube can identify four crystals. PCR is designed as a static device and does not use interpolative motion. This results in considerable advantage when performing dynamic studies. PCR is the positron tomography analog of the γ-camera widely used in nuclear medicine

  10. Bayesian analogy with relational transformations.

    Science.gov (United States)

    Lu, Hongjing; Chen, Dawn; Holyoak, Keith J

    2012-07-01

    How can humans acquire relational representations that enable analogical inference and other forms of high-level reasoning? Using comparative relations as a model domain, we explore the possibility that bottom-up learning mechanisms applied to objects coded as feature vectors can yield representations of relations sufficient to solve analogy problems. We introduce Bayesian analogy with relational transformations (BART) and apply the model to the task of learning first-order comparative relations (e.g., larger, smaller, fiercer, meeker) from a set of animal pairs. Inputs are coded by vectors of continuous-valued features, based either on human magnitude ratings, normed feature ratings (De Deyne et al., 2008), or outputs of the topics model (Griffiths, Steyvers, & Tenenbaum, 2007). Bootstrapping from empirical priors, the model is able to induce first-order relations represented as probabilistic weight distributions, even when given positive examples only. These learned representations allow classification of novel instantiations of the relations and yield a symbolic distance effect of the sort obtained with both humans and other primates. BART then transforms its learned weight distributions by importance-guided mapping, thereby placing distinct dimensions into correspondence. These transformed representations allow BART to reliably solve 4-term analogies (e.g., larger:smaller::fiercer:meeker), a type of reasoning that is arguably specific to humans. Our results provide a proof-of-concept that structured analogies can be solved with representations induced from unstructured feature vectors by mechanisms that operate in a largely bottom-up fashion. We discuss potential implications for algorithmic and neural models of relational thinking, as well as for the evolution of abstract thought. Copyright 2012 APA, all rights reserved.

  11. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Digital terrestrial broadcasting receiver in the U.K; Eikoku chijoha digital hoso jushinki

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Digital terrestrial broadcasting is broadcasted in parallel with existing UHF analog broadcasting, whereas each of allocated channel frequencies can transmit five to six programs simultaneously. Each home can receive a number of programs with the existing antenna without a need of installing a new satellite antenna or cable. Among the countries of the world running forward to digitization of broadcasting all at once, the U.K. develops advancing movements and leads the world by starting the digital terrestrial broadcasting. In addition to the digitized broadcasting of conventional analog broadcasting programs, the `Ondigitals` (broadcasting operators) have started newly the pay broadcasting. Toshiba has been selected as one of the six developers and manufacturers of digital terrestrial broadcasting receivers, and has developed the digital terrestrial broadcasting receiver DTB2000. For the modulation system, the orthogonal frequency division multiplex (OFDM) was chosen as a system being strong against ghost and most suitable for digital terrestrial broadcasting. In addition, the receiver is equipped with software download function by using the broadcasting waves, and the common interface being the communication specification specified in the DVB (digital video broadcasting) to provide future function expandability. (translated by NEDO)

  13. Generating explanations via analogical comparison.

    Science.gov (United States)

    Hoyos, Christian; Gentner, Dedre

    2017-10-01

    Generating explanations can be highly effective in promoting learning in both adults and children. Our interest is in the mechanisms that underlie this effect and in whether and how they operate in early learning. In adult reasoning, explanation may call on many subprocesses-including comparison, counterfactual reasoning, and reasoning by exclusion; but it is unlikely that all these processes are available to young children. We propose that one process that may serve both children and adults is comparison. In this study, we asked whether children would use the results of a comparison experience when asked to explain why a model skyscraper was stable. We focused on a challenging principle-that diagonal cross-bracing lends stability to physical structures (Gentner et al., Cognitive Science, 40, 224-240, 2016). Six-year-olds either received no training or interacted with model skyscrapers in one of three different conditions, designed to vary in their potential to invite and support comparison. In the Single Model condition, children interacted with a single braced model. In the comparison conditions (Low Alignability and High Alignability), children compared braced and unbraced models. Following experience with the models, children were asked to explain why the braced model was stable. They then received two transfer tasks. We found that children who received highly alignable pairs were most likely to (a) produce brace-based explanations and (b) transfer the brace principle to a dissimilar context. This provides evidence that children can benefit from analogical comparison in generating explanations and also suggests limitations on this ability.

  14. Structure of the terrestrial planets

    International Nuclear Information System (INIS)

    Lyttleton, R.A.

    1977-01-01

    Recent reviews (cf. Runcorn, 1968; or Cook, 1972, 1975) on the structure of the planets omit reference to the phase-change hypothesis for the nature of the terrestrial core, despite that numerous prior predictions of the theory based on this hypothesis have subsequently been borne out as correct. These reviews also ignore the existence of theoretical calculations of the internal structure of Venus which can be computed with high accuracy by use of the terrestrial seismic data. Several examples of numerous mistakes committed in these reviews are pointed out. (Auth.)

  15. Priapism caused by 'Tribulus terrestris'.

    Science.gov (United States)

    Campanelli, M; De Thomasis, R; Tenaglia, R L

    2016-01-01

    A 36-year-old Caucasian man was diagnosed with a 72-h-lasting priapism that occurred after the assumption of a Herbal supplement based on Tribulus terrestris, which is becoming increasingly popular for the treatment of sexual dysfunction. The patient underwent a cavernoglandular shunt (Ebbehoj shunt) in order to obtain complete detumescence, from which derived negative post-episode outcomes on sexual function. All patients consuming non-FDA-approved alternative supplements such as Tribulus terrestris should be warned about the possible serious side effects.

  16. Pilot Studies of Geologic and Terrestrial Carbon Sequestration in the Big Sky Region, USA, and Opportunities for Commercial Scale Deployment of New Technologies

    Science.gov (United States)

    Waggoner, L. A.; Capalbo, S. M.; Talbott, J.

    2007-05-01

    Within the Big Sky region, including Montana, Idaho, South Dakota, Wyoming and the Pacific Northwest, industry is developing new coal-fired power plants using the abundant coal and other fossil-based resources. Of crucial importance to future development programs are robust carbon mitigation plans that include a technical and economic assessment of regional carbon sequestration opportunities. The objective of the Big Sky Carbon Sequestration Partnership (BSCSP) is to promote the development of a regional framework and infrastructure required to validate and deploy carbon sequestration technologies. Initial work compiled sources and potential sinks for carbon dioxide (CO2) in the Big Sky Region and developed the online Carbon Atlas. Current efforts couple geologic and terrestrial field validation tests with market assessments, economic analysis and regulatory and public outreach. The primary geological efforts are in the demonstration of carbon storage in mafic/basalt formations, a geology not yet well characterized but with significant long-term storage potential in the region and other parts of the world; and in the Madison Formation, a large carbonate aquifer in Wyoming and Montana. Terrestrial sequestration relies on management practices and technologies to remove atmospheric CO2 to storage in trees, plants, and soil. This indirect sequestration method can be implemented today and is on the front-line of voluntary, market-based approaches to reduce CO2 emissions. Details of pilot projects are presented including: new technologies, challenges and successes of projects and potential for commercial-scale deployment.

  17. Flash and Continuous Photolysis Studies of the Thionitrosyl Complex Cr(CH3CN)5(NS)2+ and the Nitric Oxide Analogs. Reactions of Nitrogen Monosulfide in Solution

    DEFF Research Database (Denmark)

    Dethlefsen, Johannes Wied; Hedegård, Erik; Rimmer, R. Dale

    2009-01-01

    Photolysis of the thionitrosyl complex Cr(CH3CN)5(NS)2+ (1) in acetonitrile solution leads to the dissociation of nitrogen monosulfide (NS).  In deaerated solution, this reaction is reversible, and flash photolysis studies demonstrate that NS reacts with Cr(CH3CN)62+ according to the rate law d[1...... dependent quantum yields of 0.3-1.0 mol/Einstein. Mass spectroscopic studies of the product solutions demonstrate formation of S8, presumably from the decomposition of NS. The quantitative photochemical behaviors of 1 and the nitrosyl analog 2 are compared. Udgivelsesdato: Jan....

  18. Efficacy of Tribulus Terrestris Extract on the Serum Glucose and Lipids of Women with Diabetes Mellitus

    Science.gov (United States)

    Samani, Nasrin Babadai; Jokar, Azam; Soveid, Mahmood; Heydari, Mojtaba; Mosavat, Seyed Hamdollah

    2016-01-01

    Background: Considering folkloric use of Tribulus terrestris (T. terrestris) in diabetes and proven anti-hyperglycemic and anti-hyperlipidemic effects of T. terrestris in animal studies, we aimed to evaluate the efficacy of the hydro alcoholic extract of T. terrestris on the serum glucose and lipid profile of women with diabetes mellitus. Methods: Ninety-eight diabetic women were randomly allocated to receive the T. terrestris (1000 mg/day) or placebo for three months. The patients were evaluated in terms of the fasting blood glucose, 2-hour postprandial glucose, glycosylated hemoglobin and lipid profile. Results: T. terrestris showed a significant blood glucose lowering effect in diabetic women compared to placebo (Pterrestris group was significantly reduced compared with placebo, while no significant effect was observed in the triglyceride and high-density lipoprotein levels. Conclusion: This study showed preliminary promising hypoglycemic effect of T. terrestris in diabetic women. PMID:27840471

  19. Efficacy of Tribulus Terrestris Extract on the Serum Glucose and Lipids of Women with Diabetes Mellitus.

    Science.gov (United States)

    Samani, Nasrin Babadai; Jokar, Azam; Soveid, Mahmood; Heydari, Mojtaba; Mosavat, Seyed Hamdollah

    2016-05-01

    Considering folkloric use of Tribulus terrestris (T. terrestris) in diabetes and proven anti-hyperglycemic and anti-hyperlipidemic effects of T. terrestris in animal studies, we aimed to evaluate the efficacy of the hydro alcoholic extract of T. terrestris on the serum glucose and lipid profile of women with diabetes mellitus. Ninety-eight diabetic women were randomly allocated to receive the T. terrestris (1000 mg/day) or placebo for three months. The patients were evaluated in terms of the fasting blood glucose, 2-hour postprandial glucose, glycosylated hemoglobin and lipid profile. T. terrestris showed a significant blood glucose lowering effect in diabetic women compared to placebo (Pterrestris group was significantly reduced compared with placebo, while no significant effect was observed in the triglyceride and high-density lipoprotein levels. This study showed preliminary promising hypoglycemic effect of T. terrestris in diabetic women.

  20. Vegetation Structure, Tree Volume and Biomass Estimation using Terrestrial Laser Scanning Remote Sensing: A Case Study of the Mangrove Forests in the Everglades National Park

    Science.gov (United States)

    Feliciano, E. A.; Wdowinski, S.; Potts, M. D.

    2012-12-01

    Mangrove forests are being threatened by accelerated climate change, sea level rise and coastal projects. Carbon/above ground biomass (AGB) losses due to natural or human intervention can affect global warming. Thus, it is important to monitor AGB fluctuations in mangrove forests similar to those inhabiting the Everglades National Park (ENP). Tree volume and tree wood specific density are two important measurements for the estimation of AGB (mass = volume * density). Wood specific density is acquired in the laboratory by analyzing stem cores acquired in the field. However, tree volume is a challenging task because trees resemble tapered surfaces. The majority of published studies estimate tree volume and biomass using allometric equations, which describe the size, shape, volume or AGB of a given population of trees. However, these equations can be extremely general and might not give a representative value of volume or AGB for a specific tree species. In order to have precise biomass estimations, other methodologies for tree volume estimation are needed. To overcome this problem, we use a state-of-the-art remote sensing tool known as ground-based LiDAR a.k.a Terrestrial Laser Scanner (TLS), which can be used to precisely measure vegetation structure and tree volume from its 3-D point cloud. We surveyed three mangrove communities: (Rhizophora mangle, Laguncuria racemosa and Avicennia germinans) in three different sites along Shark River Slough (SRS), which is the primary source of water to the ENP. Our sites included: small-, intermediate- and tall- size mangroves. Our ground measurements included both: traditional forestry surveys and TLS surveys for tree attributes (tree height and diameter at breast height (DBH)) comparison. These attributes are used as input to allometric equations for the estimation of tree volume and AGB. A total of 25 scans were collected in 2011 with a Leica ScanStation C10 TLS. The 3-D point cloud acquired from the TLS data revealed that

  1. Sensing Methods for Detecting Analog Television Signals

    Science.gov (United States)

    Rahman, Mohammad Azizur; Song, Chunyi; Harada, Hiroshi

    This paper introduces a unified method of spectrum sensing for all existing analog television (TV) signals including NTSC, PAL and SECAM. We propose a correlation based method (CBM) with a single reference signal for sensing any analog TV signals. In addition we also propose an improved energy detection method. The CBM approach has been implemented in a hardware prototype specially designed for participating in Singapore TV white space (WS) test trial conducted by Infocomm Development Authority (IDA) of the Singapore government. Analytical and simulation results of the CBM method will be presented in the paper, as well as hardware testing results for sensing various analog TV signals. Both AWGN and fading channels will be considered. It is shown that the theoretical results closely match with those from simulations. Sensing performance of the hardware prototype will also be presented in fading environment by using a fading simulator. We present performance of the proposed techniques in terms of probability of false alarm, probability of detection, sensing time etc. We also present a comparative study of the various techniques.

  2. Kinematics and age of 15 stars-photometric solar analogs

    Science.gov (United States)

    Galeev, A. I.; Shimansky, V. V.

    2008-03-01

    The radial and space velocities are inferred for 15 stars that are photometric analogs of the Sun. The space velocity components (U, V, W) of most of these stars lie within the 10-60 km/s interval. The star HD 225239, which in our previous papers we classified as a subgiant, has a space velocity exceeding 100 km/s, and belongs to the thick disk. The inferred fundamental parameters of the atmospheres of solar analogs are combined with published evolutionary tracks to estimate the masses and ages of the stars studied. The kinematics of photometric analogs is compared to the data for a large group of solar-type stars.

  3. Global orbit feedback utilizing analog and digital technologies

    International Nuclear Information System (INIS)

    Singh, O.; Tang, Y.; Ramamoorthy, S.; Krinsky, S.; Yu, L.H.

    1997-01-01

    At the NSLS, an analog global orbit feedback system is used in regular operations, and a digital global orbit feedback system is available in machine physics studies on the X-Ray Ring. Here, the authors discuss the relative merits of utilizing analog and digital technology in orbit feedback. Results of experiments are reported characterizing the performance of the analog and digital systems when operated individually or together. They give their thoughts on plans for future development of the orbit feedback systems at the NSLS

  4. Concept Confusion and Concept Discernment in Basic Magnetism Using Analogical Reasoning

    Science.gov (United States)

    Lemmer, Miriam; Morabe, Olebogeng Nicodimus

    2017-01-01

    Analogical reasoning is central to all learning, whether in daily life situations, in the classroom or while doing research. Although analogies can aid the learning process of making sense of phenomena and understanding new ideas in terms of known ideas, these should be used with care. This article reports a study of the use of analogies and the…

  5. Analog circuit design art, science and personalities

    CERN Document Server

    Williams, Jim

    1991-01-01

    This book is far more than just another tutorial or reference guide - it's a tour through the world of analog design, combining theory and applications with the philosophies behind the design process. Readers will learn how leading analog circuit designers approach problems and how they think about solutions to those problems. They'll also learn about the `analog way' - a broad, flexible method of thinking about analog design tasks.A comprehensive and useful guide to analog theory and applications. Covers visualizing the operation of analog circuits. Looks at how to rap

  6. Analog Filter Design Rules for Multilevel Polybinary Signaling Generation

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Cavallero, Francisco javier Vaquero; Tafur Monroy, Idelfonso

    2014-01-01

    Polybinary signaling has gained attention lately due to its generation simplicity and reduced spectral usage. This paper presents a study on the requirements for analog filters for the generation of multilevel polybinary signals with three to nine levels.......Polybinary signaling has gained attention lately due to its generation simplicity and reduced spectral usage. This paper presents a study on the requirements for analog filters for the generation of multilevel polybinary signals with three to nine levels....

  7. Eye Movements Reveal Optimal Strategies for Analogical Reasoning.

    Science.gov (United States)

    Vendetti, Michael S; Starr, Ariel; Johnson, Elizabeth L; Modavi, Kiana; Bunge, Silvia A

    2017-01-01

    Analogical reasoning refers to the process of drawing inferences on the basis of the relational similarity between two domains. Although this complex cognitive ability has been the focus of inquiry for many years, most models rely on measures that cannot capture individuals' thought processes moment by moment. In the present study, we used participants' eye movements to investigate reasoning strategies in real time while solving visual propositional analogy problems (A:B::C:D). We included both a semantic and a perceptual lure on every trial to determine how these types of distracting information influence reasoning strategies. Participants spent more time fixating the analogy terms and the target relative to the other response choices, and made more saccades between the A and B items than between any other items. Participants' eyes were initially drawn to perceptual lures when looking at response choices, but they nonetheless performed the task accurately. We used participants' gaze sequences to classify each trial as representing one of three classic analogy problem solving strategies and related strategy usage to analogical reasoning performance. A project-first strategy, in which participants first extrapolate the relation between the AB pair and then generalize that relation for the C item, was both the most commonly used strategy as well as the optimal strategy for solving visual analogy problems. These findings provide new insight into the role of strategic processing in analogical problem solving.

  8. Eye Movements Reveal Optimal Strategies for Analogical Reasoning

    Directory of Open Access Journals (Sweden)

    Michael S. Vendetti

    2017-06-01

    Full Text Available Analogical reasoning refers to the process of drawing inferences on the basis of the relational similarity between two domains. Although this complex cognitive ability has been the focus of inquiry for many years, most models rely on measures that cannot capture individuals' thought processes moment by moment. In the present study, we used participants' eye movements to investigate reasoning strategies in real time while solving visual propositional analogy problems (A:B::C:D. We included both a semantic and a perceptual lure on every trial to determine how these types of distracting information influence reasoning strategies. Participants spent more time fixating the analogy terms and the target relative to the other response choices, and made more saccades between the A and B items than between any other items. Participants' eyes were initially drawn to perceptual lures when looking at response choices, but they nonetheless performed the task accurately. We used participants' gaze sequences to classify each trial as representing one of three classic analogy problem solving strategies and related strategy usage to analogical reasoning performance. A project-first strategy, in which participants first extrapolate the relation between the AB pair and then generalize that relation for the C item, was both the most commonly used strategy as well as the optimal strategy for solving visual analogy problems. These findings provide new insight into the role of strategic processing in analogical problem solving.

  9. Terrestrial Ecology Guide.

    Science.gov (United States)

    Morrison, James W., Ed.; Hall, James A., Ed.

    This collection of study units focuses on the study of the ecology of land habitats. Considered are such topics as map reading, field techniques, forest ecosystem, birds, insects, small mammals, soils, plant ecology, preparation of terrariums, air pollution, photography, and essentials of an environmental studies program. Each unit contains…

  10. Taiwan's industrial heavy metal pollution threatens terrestrial biota

    International Nuclear Information System (INIS)

    Hsu, M.J.; Selvaraj, K.; Agoramoorthy, G.

    2006-01-01

    The bioconcentration levels of essential (Cu, Fe, Mg, Mn, and Zn) and non-essential (As, Cd, Hg, Pb, and Sn) elements have been investigated in different terrestrial biota such as fungi, plant, earthworm, snail, crab, insect, amphibian, lizard, snake, and bat including the associated soil, to investigate the ecosystem health status in Kenting National Park, Taiwan. High bioconcentrations of Cd, Hg, and Sn in snail, earthworm, crab, lizard, snake, and bat indicated a contaminated terrestrial ecosystem. High concentrations of Cd, Hg, and Sn in plant species, effective bioaccumulation of Cd by earthworm, snail, crab and bat, as well as very high levels of Hg found in invertebrates, amphibians, and reptiles revealed a strong influence from industrial pollution on the biotic community. This study for the first time presents data on the impact of heavy metal pollution on various terrestrial organisms in Taiwan. - Metal effects occur at any terrestrial levels in Taiwan

  11. Construction of the Hunveyor-Husar space probe model system for planetary science education and analog studies and simulations in universities and colleges of Hungary.

    Science.gov (United States)

    Bérczi, Sz.; Hegyi, S.; Hudoba, Gy.; Hargitai, H.; Kokiny, A.; Drommer, B.; Gucsik, A.; Pintér, A.; Kovács, Zs.

    Several teachers and students had the possibility to visit International Space Camp in the vicinity of the MSFC NASA in Huntsville Alabama USA where they learned the success of simulators in space science education To apply these results in universities and colleges in Hungary we began a unified complex modelling in planetary geology robotics electronics and complex environmental analysis by constructing an experimental space probe model system First a university experimental lander HUNVEYOR Hungarian UNiversity surVEYOR then a rover named HUSAR Hungarian University Surface Analyser Rover has been built For Hunveyor the idea and example was the historical Surveyor program of NASA in the 1960-ies for the Husar the idea and example was the Pathfinder s rover Sojouner rover The first step was the construction of the lander a year later the rover followed The main goals are 1 to build the lander structure and basic electronics from cheap everyday PC compatible elements 2 to construct basic experiments and their instruments 3 to use the system as a space activity simulator 4 this simulator contains lander with on board computer for works on a test planetary surface and a terrestrial control computer 5 to harmonize the assemblage of the electronic system and instruments in various levels of autonomy from the power and communication circuits 6 to use the complex system in education for in situ understanding complex planetary environmental problems 7 to build various planetary environments for application of the

  12. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel

    2017-01-01

    This textbook is appropriate for use in graduate-level curricula in analog-to-digital conversion, as well as for practicing engineers in need of a state-of-the-art reference on data converters. It discusses various analog-to-digital conversion principles, including sampling, quantization, reference generation, nyquist architectures and sigma-delta modulation. This book presents an overview of the state of the art in this field and focuses on issues of optimizing accuracy and speed, while reducing the power level. This new, third edition emphasizes novel calibration concepts, the specific requirements of new systems, the consequences of 22-nm technology and the need for a more statistical approach to accuracy. Pedagogical enhancements to this edition include additional, new exercises, solved examples to introduce all key, new concepts and warnings, remarks and hints, from a practitioner’s perspective, wherever appropriate. Considerable background information and practical tips, from designing a PCB, to lay-o...

  13. Analogies between antiferromagnets and antiferroelectrics

    International Nuclear Information System (INIS)

    Enz, C.P.; Matthias, B.T.

    1980-01-01

    Ferro- and antiferromagnetism in the Laves phase TiBesub(2-x) Cusub(x) occurs for 0.1 4 H 2 PO 4 and its solid solutions with TlH 2 PO 4 and with the ferroelectric KH 2 PO 4 are discussed as function of deuteration and of pressure. Another analogy as function of pressure is established with the antiferroelectric perovskite PbZrO 3 . (author)

  14. Novel phosphanucleoside analogs of dideoxynucleosides

    Czech Academy of Sciences Publication Activity Database

    Páv, Ondřej; Buděšínský, Miloš; Rosenberg, Ivan

    2017-01-01

    Roč. 73, č. 34 (2017), s. 5220-5228 ISSN 0040-4020 R&D Projects: GA ČR(CZ) GA17-12703S; GA ČR GA13-26526S; GA MZd NV15-31604A Institutional support: RVO:61388963 Keywords : phosphanucleoside * nucleoside analog * ring-closing metathesis * stereoselective hydroboration * chiral resolution Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 2.651, year: 2016

  15. Investigation on the toxic potential of Tribulus terrestris in vitro.

    Science.gov (United States)

    Abudayyak, M; Jannuzzi, A T; Özhan, G; Alpertunga, B

    2015-04-01

    Tribulus terrestris L. (Zygophyllaceae) has been commonly used to energize, vitalize, and improve sexual function and physical performance in men. This study investigates the potential cytotoxic and genotoxic, and endocrine disrupting activities of T. terrestris in vitro. The whole T. terrestris plant was extracted with water, methanol, and chloroform. The genotoxic potential of T. terrestris extracts at 3-2400 µg/mL was assessed by Comet assay in a rat kidney cell line (NRK-52E) and by Ames assay in Salmonella typhimurium TA98 and TA100 strains. Endocrine disrupting effects of the extracts at concentrations of 0.22-25 000 µg/mL were assessed by YES/YAS assay in Saccharomyces cerevisiae. Cytotoxic activity of the extracts was determined by the MTT test in NRK-52E cells. The different exposure times were used for four tests (3-48 h). The methanol extract of T. terrestris IC50 value was 160 µg/mL. The other extracts did not show cytotoxic effects. In the Comet and Ames genotoxicity assays, none of the extracts possessed genotoxic activities at concentrations of 0-2400 µg/mL. Only the water extract of T. terrestris induced frame shift mutations after metabolic activation. The water extract also showed estrogenic activity by YES/YAS assay in S. cerevisiae at concentrations ≥27 µg/mL (≥2.6-fold), while the other T. terrestris extracts had anti-estrogenic properties. Tribulus terrestris had estrogenic and genotoxic activities. The study was useful in determining its toxicological effects and the precautions regarding consumption.

  16. Electrostatic analogy for symmetron gravity

    Science.gov (United States)

    Ogden, Lillie; Brown, Katherine; Mathur, Harsh; Rovelli, Kevin

    2017-12-01

    The symmetron model is a scalar-tensor theory of gravity with a screening mechanism that suppresses the effect of the symmetron field at high densities characteristic of the Solar System and laboratory scales but allows it to act with gravitational strength at low density on the cosmological scale. We elucidate the screening mechanism by showing that in the quasistatic Newtonian limit there are precise analogies between symmetron gravity and electrostatics for both strong and weak screening. For strong screening we find that large dense bodies behave in a manner analogous to perfect conductors in electrostatics. Based on this analogy we find that the symmetron field exhibits a lightning rod effect wherein the field gradients are enhanced near the ends of pointed or elongated objects. An ellipsoid placed in a uniform symmetron gradient is shown to experience a torque. By symmetry there is no gravitational torque in this case. Hence this effect unmasks the symmetron and might serve as the basis for future laboratory experiments. The symmetron force between a point mass and a large dense body includes a component corresponding to the interaction of the point mass with its image in the larger body. None of these effects have counterparts in the Newtonian limit of Einstein gravity. We discuss the similarities between symmetron gravity and the chameleon model as well as the differences between the two.

  17. Assessment of the primary stability of root analog zirconia implants designed using cone beam computed tomography software by means of the Periotest® device: An ex vivo study. A preliminary report.

    Science.gov (United States)

    Matys, Jacek; Świder, Katarzyna; Flieger, Rafał; Dominiak, Marzena

    2017-08-01

    The implant primary stability is a fundamental prerequisite for a success of osseointegration process which determines the prosthetic reconstruction time. The aim of the present study was to assess the quality and precision of modern conical bone computer tomography (CBCT) software in preparing root analog zirconia implants (RAZIs) by measuring its primary stability by means of the Periotest device. Thirteen pig jaws with proper erupted first premolar (P1) teeth were used in the study. The CBCT examination was conducted in the area of the P1 tooth in each mandible. The 3-dimensional (3D) view of each tooth was designed from CBCT scan. The created 3D images were used to prepare root analog zirconia implants milled from a medical-grade zirconia block by means of laboratory milling. The RAZIs and titanium implants were placed into an alveolar socket after the tooth had been removed. The primary stability of the teeth before their extraction (G1), RAZIs (G2) and titanium implants (G3) were checked by Periotest devices. The mean results in PTV were: 15.9, 3.35, 12.7 for G1, G2 and G3 group, respectively. RAZIs during immediate loading achieved a significantly higher primary stability (lower Periotest value) as compared to the teeth and implants. The modern CBCT device allows us to design a precise image of an extracted tooth for the purpose of manufacturing a root analog implant. The additional feature of the surgical protocol using RAZI is the possibility of avoiding the augmentation procedure, which reduces the whole cost of the treatment.

  18. Terrestrial Ecology Section

    International Nuclear Information System (INIS)

    Harris, W.F.

    1978-01-01

    Studies on ecological effects of coal combustion included the following: episodic air pollution stress; interaction of gaseous pollutants and acid precipitation; and brimstone: preliminary results from SO 2 effects on forest growth. Studies on fate and transport of contaminants included deposition of aerosol-associated trace elements to a deciduous forest; hydrologic source areas; and environmental behavior of mercury. The environmental research park is described and forest resource management is discussed. Ecosystem analysis studies included hydrology of Walker branch; water budget of an oak-hickory forest; nutrient release from decaying wood; transpiration of the tulip poplar; and atmospheric CO 2 and its interaction with biospheric changes

  19. PRELIMINARY RESULTS OF THE MONUMENTAL TREE MONITORING BASED ON TERRESTRIAL LASER SCANNING - A CASE STUDY OF THE OAK BARTEK IN ZAGNAŃSK (POLAND

    Directory of Open Access Journals (Sweden)

    Wezyk Piotr

    2015-12-01

    Full Text Available In April 2013, the Laboratory of Geomatics launched the project under the acronym “Bartek 3D” in cooperation with the Research Section of Students from the AGH in Krakow, Pedagogical University and the Jagiellonian University as well. The main aim of the project is to monitor the biggest and probably one of the oldest treesin Poland - Oak Bartek in Zagnańsk (N 50o59’14”; E 20o38’59”, based on multi-temporal Terrestrial Laser Scanning (TLS technology. One of the results of the project should be a 3D model ofOak Bartek and detection of the changes in the shape of the tree. Terrestrial Laser Scanning and the traditional forest inventory measurements were performed during the Leaf-OFF season in April 2013 and April 2014 and repeated in Leaf-ON period in July 2013 and October 2014 with using scanners: FARO FOCUS 3D, RIEGL VZ-400, LEICA C10 and RevScan (HandyScan. The results based on TLS technology showed some differences comparing to existing data obtained by traditional measurements for forestry inventory: • Height (H of the tree: altimeter Vertex (Haglöf H = 29.31m; HTLS= 28.49 m; • Trunk circumference (L measured with stretched tape: LST = 9.80 m; adjacent along the shape of bark: LT= 13.70 m; TLS measurments: LTLS1/4 = 9.97 m and LRevScan= 13.54 m • The average diameter at breast height (DBH130cm calculated on the basis of 3D basal area of stem DBHTLS1/4 = 3.03 m (DBHT= 3.12 m.

  20. Development of the Gecko (Pachydactylus turneri) Animal Model during Foton M-2 to Study Comparative Effects of Microgravity in Terrestrial and Aquatic Organisms

    Science.gov (United States)

    Almeida, E. A.; Roden, C.; Phillips, J. A.; Globus, R. K.; Searby, N.; Vercoutere, W.; Morey-Holton, E.; Gulimova, V.; Saveliev, S.; Tairbekov, M.; hide

    2006-01-01

    Terrestrial organisms exposed to microgravity during spaceflight experience degeneration in bone, muscle, and possibly other tissues that require gravity-mediated mechanical stimulation for normal regenerative growth. In the Gecko experiment aboard Foton M-2, we flew for the first time, five terrestrial Pachydactylus turneri specimens to develop a model of microgravity effects comparable to the newt Pleurodeles waltl, a well-established model organism for spaceflight. These lower vertebrate species have similar body plans and size, are poikilothermic, have tissue regenerative ability, and are adapted to moderate periods of fasting. Furthermore the gecko (Pachydactylus) can also survive prolonged periods without water. In pre-flight control experiments and after a 16-day Foton M-2 spaceflight without food or water, the geckos were recovered and showed no apparent negative health effects. However, detailed analysis of bone mass and architecture by micro Computed Tomography { pCT), showed that both synchronous control and spaceflight animals lost significant amounts of cancellous bone in the distal femur and humerus relative to basal controls. In addition, cell cycle analysis of 30h post-flight liver tissue reveals a shift of DNA content from G2 and S to G1, both in spaceflight and synchronous controls. Together, these results suggest that housing conditions alone induce rapid catabolism of cancellous bone and reduced normal tissue regeneration. Further use of the gecko Puchydactylus turneri as a spaceflight model requires modification of housing conditions, possibly by including water and food, or changing other factors such as eliminating housing stresses to obtain stable bone structure and tissue regeneration during spaceflight experiments.