WorldWideScience

Sample records for terrestrial background reduction

  1. Terrestrial Background Reduction in RPM Systems by Direct Internal Shielding

    International Nuclear Information System (INIS)

    Robinson, Sean M.; Ashbaker, Eric D.; Schweppe, John E.

    2008-01-01

    Gamma-ray detection systems that are close to the earth or other sources of background radiation often require shielding, especially when trying to detect a relatively weak source. One particular case of interest that we address in this paper is that encountered by the Radiation Portal Monitors (RPMs) systems placed at border-crossing Ports of Entry (POE). These RPM systems are used to screen for illicit radiological materials, and they are often placed in situations where terrestrial background is large. In such environments, it is desirable to consider simple physical modifications that could be implemented to reduce the effects from background radiation without affecting the flow of traffic and the normal operation of the portal. Simple modifications include adding additional shielding to the environment, either inside or outside the apparatus. Previous work (2) has shown the utility of some of these shielding configurations for increasing the Signal to Noise Ratio (SNR) of gross-counting RPMs. Because the total cost for purchasing and installing RPM systems can be quite expensive, in the range of hundreds of thousands of dollars for each cargo-screening installation, these shielding variations may offer increases in detection capability for relatively small cost. Several modifications are considered here in regard to their real-world applicability, and are meant to give a general idea of the effectiveness of the schemes used to reduce background for both gross-counting and spectroscopic detectors. These scenarios are modeled via the Monte-Carlo N-Particle (MCNP) code package (1) for ease of altering shielding configurations, as well as enacting unusual scenarios prior to prototyping in the field. The objective of this paper is to provide results representative of real modifications that could enhance the sensitivity of this, as well as the next generation of radiation detectors. The models used in this work were designed to provide the most general results for

  2. Background reduction in the SNO+ experiment

    Energy Technology Data Exchange (ETDEWEB)

    Segui, L. [University of Oxford, Denys Wilkinson Building, Keble Road, OX1 Oxford (United Kingdom)

    2015-08-17

    SNO+ is a large multi-purpose liquid scintillator experiment, which first aim is to detect the neutrinoless double beta decay of {sup 130}Te. It is placed at SNOLAB, at 6000 m.w.e. and it is based on the SNO infrastructure. SNO+ will contain approximately 780 tonnes of liquid scintillator, loaded with {sup 130}Te inside an acrylic vessel (AV) with an external volume of ultra pure water to reduce the external backgrounds. Light produced in the scintillator by the interaction of particles will be detected with about 9,000 photomultiplier’s. For the neutrinoless double beta decay phase, due to its the extremely low rate expected, the control, knowledge and reduction of the background is essential. Moreover, it will also benefit other phases of the experiment focused on the study of solar neutrinos, nucleon decay, geoneutrinos and supernovae. In order to reduce the internal background level, a novel purification technique for tellurium loaded scintillators has been developed by the collaboration that reduces the U/Th concentration and several cosmic-activated isotopes by at least a factor 10{sup 2} -10{sup 3} in a single pass. In addition, different rejection techniques have been developed for the remaining internal backgrounds based on Monte-Carlo simulations. In this work, the scintillator purification technique and the levels obtained with it will be discussed. Furthermore, an overview of the different backgrounds for the double-beta phase will be presented, highlighting some of the techniques developed to reject the remained decays based on their expected timing differences.

  3. Background reduction in a young interferometer biosensor

    NARCIS (Netherlands)

    Mulder, H. K P; Subramaniam, V.; Kanger, J. S.

    2014-01-01

    Integrated optical Young interferometer (IOYI) biosensors are among the most sensitive label-free biosensors. Detection limits are in the range of 20 fg/mm2. The applicability of these sensors is however strongly hampered by the large background that originates from both bulk refractive index

  4. Intersystem Interference Reduction for Overlaid HAPS-Terrestrial CDMA System

    Science.gov (United States)

    Huang, Jeng-Ji; Wang, Wei-Ting; Li, Mingfu; Shiung, David; Ferng, Huei-Wen

    In this letter, we propose that directional antennas, combined with power management, be incorporated to reduce intersystem interference in a shared band overlaid high altitude platform station (HAPS)-terrestrial code division multiple access (CDMA) system. To eliminate the HAPS to terrestrial interference, the HAPS is accessed only via directional antennas under the proposed scheme. By doing so, the uplink power to the HAPS can accordingly be increased, so that the terrestrial to HAPS interference is also effectively suppressed.

  5. Investigation of reduction in background counts of clover detector

    International Nuclear Information System (INIS)

    Kshetri, Ritesh

    2015-01-01

    The peak-to-total ratio can be improved by increasing the full energy peak (FEP) counts and/or by decreasing the background counts. It is notable that FEP counts will be effected by mode of operation, while background counts will be effected by both modes of operation and suppression cases. It would be interesting to know if the reduction in background is caused more by active suppression or by add back process. We introduce a simple formalism to investigate the reduction of background counts for different cases-single crystal or add back mode with active or passive suppression. A more sophisticated formalism for modeling a general composite detector had been presented in a series of six recent papers by the author

  6. The reduction of background signal in bismuth germanate scintillators

    International Nuclear Information System (INIS)

    Lewis, T.A.

    1986-07-01

    Bismuth germanate (BGO) is one of several new scintillator materials developed in recent years. It has similar energy resolution (6-8%) to sodium iodide (NaI) but it is non-hygroscopic, has a much better Peak-to-Compton ratio and a stopping power about 2.3 times greater than NaI. For counting activated foils it represents an improvement on NaI for high efficiency counting where the resolution of a germanium spectrometer is not required. Two scintillators bought for this purpose were found to have a higher than expected background signal between 500 keV and 2 MeV which was traced to Bi207, an active isotope of bismuth with a 38 year half-life and not listed as occurring naturally. Reference to the manufacturer showed all crystals to be similarly contaminated. It is speculated that this active isotope arises from cosmic proton activation of associated lead in the ore from which the bismuth is extracted. Although not confirmed rigorously it has been shown that bismuth extracted from ore with a low lead content does not contain Bi207. Scintillators have been manufactured from uncontaminated material and reductions in the background signal of more than an order of magnitude have been achieved. This reduction will be of immediate benefit for monitoring nickel foils (fast flux monitors) activated in zero-energy reactors and should also permit the exploitation of other low probability reactions previously not thought to be feasible. (author)

  7. Moving in the Anthropocene: Global reductions in terrestrial mammalian movements

    OpenAIRE

    Boehning-Gaese, Katrin; Fagan, William F.; Fryxell, John M.; Van Moorter, Bram; Alberts, Susan C.; Ali, Abdullahi H.; Allen, Andrew M.; Attias, Nina; Avgar, Tal; Bartlam-Brooks, Hattie; Bayarbaatar, Buuveibaatar; Belant, Jerrold L.; Bertassoni, Alessandra; Beyer, Dean; Bidner, Laura

    2018-01-01

    Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral cha...

  8. Radon Daughters Background Reduction in Alpha Particles Counting System

    International Nuclear Information System (INIS)

    Dadon, S. S.; Pelled, O.; Orion, I.

    2014-01-01

    The ABPC method is using a serially occurring events of the beta decay of the 214Bi fallow by alpha decay of the 214Po that take place almost simultaneously to detect the Pseudo Coincidence Event (PCE) from the RDP, and to subtract them from the gross alpha counts. 267 This work showed that it is possible to improve the efficiency of RDP background reduction, including subtracting the 218Po contribution by using the ABPC method based on a single solid state silicon PIPS detector. False counts percentage obtained at the output of the PCE circuit were smaller than 0.1%. The results show that the PCE circuit was not influenced by non RDP alpha emitters. The PCE system did not reduce the non PCE of the 218Po. After 20 minutes the 218Po was strongly decayed, and its contribution became negligible. In order to overcome this disadvantage, a mathematical matching calculations for the 214Po and the 218Po decay equations were employed, and a constant ratio of the APo214(0) / APo218(0) was obtained. This ratio can be used to estimate the count rate of the 218Po at the first 20 minutes, and to subtract it from the total count rate in order to obtain correct RDP reduction

  9. Moving in the Anthropocene: Global reductions in terrestrial mammalian movements

    Science.gov (United States)

    Tucker, Marlee A.; Böhning-Gaese, Katrin; Fagan, William F.; Fryxell, John; Van Moorter, Bram; Alberts, Susan C; Ali, Abdullahi H.; Allen, Andrew M.; Attias, Nina; Avgar, Tal; Bartlam-Brooks, Hattie; Bayarbaatar, Buuveibaatar; Belant, Jerrold L.; Bertassoni, Alessandra; Beyer, Dean; Bidner, Laura; M. van Beest, Floris; Blake, Stephen; Blaum, Niels; Bracis, Chloe; Brown, Danielle; Nico de Bruyn, P. J.; Cagnacci, Francesca; Calabrese, J.M.; Camilo-Alves, Constança; Chamaillé-Jammes, Simon; Chiaradia, Andre; Davidson, Sarah C.; Dennis, Todd; DeStefano, Stephen; Diefenbach, Duane R.; Douglas-Hamilton, Iain; Fennessy, Julian; Fichtel, Claudia; Fiedler, Wolfgang; Fischer, Christina; Fischhoff, Ilya; Fleming, Christen H.; Ford, Adam T.; Fritz, Susanne A.; Gehr, Benedikt; Goheen, Jacob R.; Gurarie, Eliezer; Hebblewhite, Mark; Heurich, Marco; Mark Hewison, A.J.; Hof, Christian; Hurme, Edward; Isbell, Lynne A.; Janssen, René; Jeltsch, Florian; Kaczensky, Petra; Kane, Adam; Kappeler, Peter M.; Kauffman, Matthew J.; Kays, Roland; Kimuyu, Duncan; Koch, Flavia; Kranstauber, Bart; LaPoint, Scott; Leimgruber, Peter; Linnell, John D. C.; López-López, Pascual; Markham, A. Catherine; Mattisson, Jenny; Medici, Emilia Patricia; Mellone, Ugo; Merrill, E.; de Miranda Mourão, Guilherme; Morato, Ronaldo G.; Morellet, Nicolas; Morrison, Thomas A.; Díaz-Muñoz, Samuel L.; Mysterud, Atle; Nandintsetseg, Dejid; Nathan, Ran; Niamir, Aidin; Odden, John; O'Hara, Robert B.; Oliveira-Santos, Luiz G. R.; Olson, Kirk A.; Patterson, Bruce D.; Cunha de Paula, Rogerio; Pedrotti, Luca; Reineking, Björn; Rimmler, Martin; Rogers, T.L.; Rolandsen, Christer Moe; Rosenberry, Christopher S.; Rubenstein, Daniel I.; Safi, Kamran; Saïd, Sonia; Sapir, Nir; Sawyer, Hall; Schmidt, Niels Martin; Selva, Nuria; Sergiel, Agnieszka; Shiilegdamba, Enkhtuvshin; Silva, João Paulo; Singh, N.; Solberg, Erling J.; Spiegel, Orr; Strand, Olav; Sundaresan, S.R.; Ullmann, Wiebke; Voigt, Ulrich; Wall, J.; Wattles, David W.; Wikelski, Martin; Wilmers, Christopher C.; Wilson, Jon W.; Wittemyer, George; Zięba, Filip; Zwijacz-Kozica, Tomasz; Mueller, Thomas

    2018-01-01

    Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects not only population persistence but also ecosystem processes such as predator-prey interactions, nutrient cycling, and disease transmission.

  10. Spatial distribution of caesium-137 in soil cover of background terrestrial ecosystems, Central European Russia

    Energy Technology Data Exchange (ETDEWEB)

    Paramonova, Tatiana A. [Radioecology and Ecotoxicology Department of Soil Science Faculty, Moscow State Lomonosov University, 119234 Moscow (Russian Federation); Shamshurina, Evgenia N. [Laboratory of soil erosion and fluvial processes of Geography Faculty, Moscow State Lomonosov University, 119234 Moscow (Russian Federation)

    2014-07-01

    ¹³⁷Cs - the main long-living anthropogenic radionuclide - arrived in mass at Russian terrestrial ecosystems after nuclear tests in the atmosphere in 1960-yy. and after Chernobyl accident in 1986 y., but in spite of a long period since these events soil cover contamination by ¹³⁷Cs is considered as extremely resistant due to its firmly fixation by soil solid matter and a long half-life of the radionuclide. Wide-scale investigation in maximal diversity of natural, semi-natural and anthropogenic landscapes of Central European Russia (more than 400 soils samples from Vologda, Yaroslavl, Ivanovo, Tver regions which are representative for the southern taiga zone) demonstrates that modern average specific activity of ¹³⁷Cs in the upper 15-cm layer of soil is 11±3 Bq/kg (contamination density 0.05±0.01 Ci/km²), that is fully ecologically acceptable. It is important that the average concentrations of ¹³⁷Cs in the soil cover of individual regions are close to each other. The most likely these average values are approximate assessment of background radioactive contamination of soils in central European Russia outside of the immediate Chernobyl trace. At the same time approximately 3% of soils are characterized by elevated ¹³⁷Cs content - 62-98 Bq/kg (0.24-0.43 Ci/km²), that indicates the presence of low radioactive spots on the territory and may be considered as local Chernobyl fallout. All of them attribute with forest soils which are commonly characterized by considerably more high accumulation of ¹³⁷Cs (18±5 Bq/kg, 0.06±0.01 Ci/km²) due to advanced absorbing surface of trees. Agricultural lands (plagued or under meadows) and soils of industrial plots with scarce vegetation contain only 6±2 Bq/kg (0.03±0.01 Ci/km²) of ¹³⁷Cs. About 84-92% of ¹³⁷Cs are concentrated in the upper 15-cm layer of natural soils or in Ap horizon of plagued soils, thus vertical migration of radionuclide is very slow in spite of ~30 years after Chernobyl

  11. Surface Sensitive Bolometer for the CUORE background reduction

    International Nuclear Information System (INIS)

    Pedretti, M.; Foggetta, L.; Giuliani, A.; Nones, C.; Sangiorgio, S.

    2005-01-01

    The most critical point of the CUORE Project [CUORE Proposal, see the web page: http://crio.mib.infn.it/wig] is the background level (BKGL) in the neutrinoless double beta decay (0νββ) region that is dominated by degraded particles coming from materials that face the detectors. Surface Sensitive Bolometers (SSBs) have been developed in order to reduce the BKGL by means of an active background discrimination. The principle of this technique and the first results obtained are briefly described in the following paper

  12. Genetic background impacts vaccine-induced reduction of pneumococcal colonization

    NARCIS (Netherlands)

    Kuipers, Kirsten; Van Selm, Saskia; van Opzeeland, Fred; Langereis, Jeroen D.; Verhagen, Lilly M.; Diavatopoulos, Dimitri A.; De Jonge, Marien I.

    2017-01-01

    Vaccination has been one of the most successful strategies to reduce morbidity and mortality caused by respiratory infections. Recent evidence suggests that differences in the host genetic background and environmental factors may contribute to heterogeneity in the immune response to vaccination.

  13. Detector Background Reduction by Passive and Active Shielding

    International Nuclear Information System (INIS)

    Bikit, I.; Bikit, K.; Forkapic, S.; Mrda, D.; Nikolov, J.; Slivka, J.; Todorovic, N.

    2013-01-01

    The operational problems of the gamma ray spectrometer shielded passively with 12 cm of lead and actively by five 0.5 m × 0.5 m × 0.05 m plastic veto shields are described. The active shielding effect from both environmental gamma ray, cosmic muons and neutrons was investigated. For anticoincidence gating wide range of scintillator pulses, corresponding to the energy range of 150 keV-75 MeV, were used. With the optimal set up the integral background, for the energy region of 50 - 3000 keV, of 0.31 c/s was achieved. The detector mass related background was 0.345 c/(kg s). The 511 keV annihilation line was reduced by the factor of 7 by the anticoincidence gate. It is shown that the plastic shields increase the neutron capture gamma line intensities due to neutron termalization.(author)

  14. Drought-induced reduction in global terrestrial net primary production from 2000 through 2009.

    Science.gov (United States)

    Zhao, Maosheng; Running, Steven W

    2010-08-20

    Terrestrial net primary production (NPP) quantifies the amount of atmospheric carbon fixed by plants and accumulated as biomass. Previous studies have shown that climate constraints were relaxing with increasing temperature and solar radiation, allowing an upward trend in NPP from 1982 through 1999. The past decade (2000 to 2009) has been the warmest since instrumental measurements began, which could imply continued increases in NPP; however, our estimates suggest a reduction in the global NPP of 0.55 petagrams of carbon. Large-scale droughts have reduced regional NPP, and a drying trend in the Southern Hemisphere has decreased NPP in that area, counteracting the increased NPP over the Northern Hemisphere. A continued decline in NPP would not only weaken the terrestrial carbon sink, but it would also intensify future competition between food demand and proposed biofuel production.

  15. Gravitational-wave confusion background from cosmological compact binaries: Implications for future terrestrial detectors

    International Nuclear Information System (INIS)

    Regimbau, T.; Hughes, Scott A.

    2009-01-01

    Increasing the sensitivity of a gravitational-wave (GW) detector improves our ability to measure the characteristics of detected sources. It also increases the number of weak signals that contribute to the data. Because GW detectors have nearly all-sky sensitivity, they can be subject to a confusion limit: Many sources which cannot be distinguished may be measured simultaneously, defining a stochastic noise floor to the sensitivity. For GW detectors operating at present and for their planned upgrades, the projected event rate is sufficiently low that we are far from the confusion-limited regime. However, some detectors currently under discussion may have large enough reach to binary inspiral that they enter the confusion-limited regime. In this paper, we examine the binary inspiral confusion limit for terrestrial detectors. We consider a broad range of inspiral rates in the literature, several planned advanced gravitational-wave detectors, and the highly advanced 'Einstein telescope' design. Though most advanced detectors will not be impacted by this limit, the Einstein telescope with a very low-frequency 'seismic wall' may be subject to confusion noise. At a minimum, careful data analysis will be require to separate signals which will appear confused. This result should be borne in mind when designing highly advanced future instruments.

  16. Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia

    Directory of Open Access Journals (Sweden)

    G. C. Edwards

    2013-05-01

    Full Text Available This paper presents the first gaseous elemental mercury (GEM air-surface exchange measurements obtained over naturally enriched and background (−1 Hg terrestrial landscapes in Australia. Two pilot field studies were carried out during the Australian autumn and winter periods at a copper-gold-cobalt-arsenic-mercury mineral field near Pulganbar, NSW. GEM fluxes using a dynamic flux chamber approach were measured, along with controlling environmental parameters over three naturally enriched and three background substrates. The enriched sites results showed net emission to the atmosphere and a strong correlation between flux and substrate Hg concentration, with average fluxes ranging from 14 ± 1 ng m−2 h−1 to 113 ± 6 ng m−2 h−1. Measurements at background sites showed both emission and deposition. The average Hg flux from all background sites showed an overall net emission of 0.36 ± 0.06 ng m−2 h−1. Fluxes show strong relationships with temperature, radiation, and substrate parameters. A compensation point of 2.48, representative of bare soils was determined. For periods of deposition, dry deposition velocities ranged from 0.00025 cm s−1 to 0.0083 cm s−1 with an average of 0.0041 ± 0.00018 cm s−1, representing bare soil, nighttime conditions. Comparison of the Australian data to North American data suggests the need for Australian-specific mercury air-surface exchange data representative of Australia's unique climatic conditions, vegetation types, land use patterns and soils.

  17. Abiotic nitrogen fixation on terrestrial planets: reduction of NO to ammonia by FeS.

    Science.gov (United States)

    Summers, David P; Basa, Ranor C B; Khare, Bishun; Rodoni, David

    2012-02-01

    Understanding the abiotic fixation of nitrogen and how such fixation can be a supply of prebiotic nitrogen is critical for understanding both the planetary evolution of, and the potential origin of life on, terrestrial planets. As nitrogen is a biochemically essential element, sources of biochemically accessible nitrogen, especially reduced nitrogen, are critical to prebiotic chemistry and the origin of life. Loss of atmospheric nitrogen can result in loss of the ability to sustain liquid water on a planetary surface, which would impact planetary habitability and hydrological processes that shape the surface. It is known that NO can be photochemically converted through a chain of reactions to form nitrate and nitrite, which can be subsequently reduced to ammonia. Here, we show that NO can also be directly reduced, by FeS, to ammonia. In addition to removing nitrogen from the atmosphere, this reaction is particularly important as a source of reduced nitrogen on an early terrestrial planet. By converting NO directly to ammonia in a single step, ammonia is formed with a higher product yield (~50%) than would be possible through the formation of nitrate/nitrite and subsequent conversion to ammonia. In conjunction with the reduction of NO, there is also a catalytic disproportionation at the mineral surface that converts NO to NO₂ and N₂O. The NO₂ is then converted to ammonia, while the N₂O is released back in the gas phase, which provides an abiotic source of nitrous oxide.

  18. The effects of noise reduction technologies on the acceptance of background noise.

    Science.gov (United States)

    Lowery, Kristy Jones; Plyler, Patrick N

    2013-09-01

    Directional microphones (D-Mics) and digital noise reduction (DNR) algorithms are used in hearing aids to reduce the negative effects of background noise on performance. Directional microphones attenuate sounds arriving from anywhere other than the front of the listener while DNR attenuates sounds with physical characteristics of noise. Although both noise reduction technologies are currently available in hearing aids, it is unclear if the use of these technologies in isolation or together affects acceptance of noise and/or preference for the end user when used in various types of background noise. The purpose of the research was to determine the effects of D-Mic, DNR, or the combination of D-Mic and DNR on acceptance of noise and preference when listening in various types of background noise. An experimental study in which subjects were exposed to a repeated measures design was utilized. Thirty adult listeners with mild sloping to moderately severe sensorineural hearing loss participated (mean age 67 yr). Acceptable noise levels (ANLs) were obtained using no noise reduction technologies, D-Mic only, DNR only, and the combination of the two technologies (Combo) for three different background noises (single-talker speech, speech-shaped noise, and multitalker babble) for each listener. In addition, preference rankings of the noise reduction technologies were obtained within each background noise (1 = best, 3 = worst). ANL values were significantly better for each noise reduction technology than baseline; and benefit increased significantly from DNR to D-Mic to Combo. Listeners with higher (worse) baseline ANLs received more benefit from noise reduction technologies than listeners with lower (better) baseline ANLs. Neither ANL values nor ANL benefit values were significantly affected by background noise type; however, ANL benefit with D-Mic and Combo was similar when speech-like noise was present while ANL benefit was greatest for Combo when speech spectrum noise was

  19. Background Reduction around Prompt Gamma-ray Peaks from Korean White Ginseng

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. N.; Sun, G. M.; Moon, J. H.; Chung, Y. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Y. E. [Chung-buk National University, Chungju (Korea, Republic of)

    2007-10-15

    Prompt gamma-ray activation analysis (PGAA) is recognized as a very powerful and unique nuclear method in terms of its non-destruction, high precision, and no time-consuming advantages. This method is used for the analysis of trace elements in various types of sample matrix such as metallurgical, environmental, biological samples, etc. When a spectrum is evaluated, background continuum is a major disturbing factor for a precise and accurate analysis. Furthermore, a prompt gamma spectrum is complicate with a wide range. To make the condition free from this limitation, a reduction of the background is important for the PGAA analysis. The background-reducing methods are divided into using the electronic equipment like a suppression mode and principal component analysis (PCA) based on a multivariate statistical method. In PGAA analysis, Lee et al. compared the background reduction methods like PCA and wavelet transform for the prompt gamma-ray spectra. Lim et al. have applied the multivariate statistical method to the identification of the peaks with low-statistics from the explosives. In this paper, effective reduction of background in the prompt gamma spectra using the PCA is applied to the prompt gammaray peaks from Korean Baeksam (Korean white ginseng)

  20. Background reduction and noise discrimination in the proportional counting of tritium using pulse-shape analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hochel, R C; Hayes, D W [Du Pont de Nemours (E.I.) and Co., Aiken, S.C. (USA). Savannah River Lab.

    1975-12-01

    A pulse-shape analysis (PSA) unit of commercial design has been incorporated into a proportional counting system to determine the effectiveness of pulse-shape discrimination in increasing the sensitivity of tritium counting. It was found that a quantitative determination of tritium could be obtained directly from the PSA time spectrum eliminating the need for beta-ray energy selection used in the pulse-shape discrimination (PSD) technique. The performance of the proportional counting system was tested using the PSA unit and anticoincidence shielding, both singly and combined, under several types of background. A background reduction factor of 169 was obtained from the combined PSA-anticoincidence system with only a 2% loss in tritium counting efficiency. The PSA method was also found to offer significant reductions in noise background.

  1. Background reduction and noise discrimination in the proportional counting of tritium using pulse-shape analysis

    International Nuclear Information System (INIS)

    Hochel, R.C.; Hayes, D.W.

    1975-01-01

    A pulse-shape analysis (PSA) unit of commercial design has been incorporated into a proportional counting system to determine the effectiveness of pulse-shape discrimination in increasing the sensitivity of tritium counting. It was found that a quantitative determination of tritium could be obtained directly from the PSA time spectrum eliminating the need for beta-ray energy selection used in the pulse-shape discrimination (PSD) technique. The performance of the proportional counting system was tested using the PSA unit and anticoincidence shielding, both singly and combined, under several types of background. A background reduction factor of 169 was obtained from the combined PSA-anticoincidence system with only a 2% loss in tritium counting efficiency. The PSA method was also found to offer significant reductions in noise background. (Auth.)

  2. Background information on a multimedia nitrogen emission reduction strategy; Hintergrundpapier zu einer multimedialen Stickstoffemissionsminderungsstrategie

    Energy Technology Data Exchange (ETDEWEB)

    Geupel; Jering; Frey (and others)

    2009-04-15

    The background information report on a multimedia nitrogen reduction strategy covers the following chapters: 1. Introduction: the nitrogen cascade and the anthropogenic influence, environmental impact of increased nitrogen emissions and effects on human health. 2. Sources and balancing of anthropogenic nitrogen emissions in Germany. 3. Environmental quality targets, activity goals of environmental measures and instruments of an integrated nitrogen reduction strategy. 4. Conclusions and perspectives. The attachments include emission sources, nitrogen release and nitrogen transport in Germany; catalogue of measures and instruments according the criteria efficiency and cost-efficacy.

  3. A Background Noise Reduction Technique Using Adaptive Noise Cancellation for Microphone Arrays

    Science.gov (United States)

    Spalt, Taylor B.; Fuller, Christopher R.; Brooks, Thomas F.; Humphreys, William M., Jr.; Brooks, Thomas F.

    2011-01-01

    Background noise in wind tunnel environments poses a challenge to acoustic measurements due to possible low or negative Signal to Noise Ratios (SNRs) present in the testing environment. This paper overviews the application of time domain Adaptive Noise Cancellation (ANC) to microphone array signals with an intended application of background noise reduction in wind tunnels. An experiment was conducted to simulate background noise from a wind tunnel circuit measured by an out-of-flow microphone array in the tunnel test section. A reference microphone was used to acquire a background noise signal which interfered with the desired primary noise source signal at the array. The technique s efficacy was investigated using frequency spectra from the array microphones, array beamforming of the point source region, and subsequent deconvolution using the Deconvolution Approach for the Mapping of Acoustic Sources (DAMAS) algorithm. Comparisons were made with the conventional techniques for improving SNR of spectral and Cross-Spectral Matrix subtraction. The method was seen to recover the primary signal level in SNRs as low as -29 dB and outperform the conventional methods. A second processing approach using the center array microphone as the noise reference was investigated for more general applicability of the ANC technique. It outperformed the conventional methods at the -29 dB SNR but yielded less accurate results when coherence over the array dropped. This approach could possibly improve conventional testing methodology but must be investigated further under more realistic testing conditions.

  4. Filter-fluorescer x-ray spectrometer using solid state detectors for γ-ray background reduction

    International Nuclear Information System (INIS)

    Yokoi, Takashi; Kitagawa, Yoneyoshi; Shiraga, Hiroyuki; Matsunaga, Hirohide; Kato, Yoshiaki; Yamanaka, Chiyoe.

    1986-01-01

    Filter-fluorescer x-ray spectrometer using solid state photo-detectors instead of the photomultiplier tubes in order to reduce the γ-ray background noise is reported. A significant reduction of the γ-ray background noise is expected, because solid state photo-detectors are very small in size compared with the photomultiplier tubes. It has been confirmed that the γ-ray background is reduced in the target irradiation experiments with the Gekko MII glass laser. (author)

  5. Trends in European background air reflect reductions in primary emissions of PCBs and PBDEs.

    Science.gov (United States)

    Schuster, Jasmin K; Gioia, Rosalinda; Breivik, Knut; Steinnes, Eiliv; Scheringer, Martin; Jones, Kevin C

    2010-09-01

    Data are presented for polychlorinated biphenyls (PCBs) and polybrominated diphenyls ethers (PBDEs) in passive air samplers (PAS) collected along a rural/remote latitudinal transect from southern UK to northern Norway during 2004-2008. This study is part of an ongoing campaign, using semipermeable membrane devices (SPMDs) as PAS over two year intervals since 1994. Absolute sequestered amounts of selected PCB congeners have decreased in a first order fashion between 1994-2008, with the average time of 8.4+/-3.2 years for atmospheric concentrations to decline by 50%. PCBs have continued to fractionate with latitude during this period. PBDE concentrations declined by 50% between 2000 and 2008 every 2.2+/-0.4 years. Results are discussed in terms of sources, long-range atmospheric transport, global fractionation, and clearance processes. It is concluded that the spatial and temporal trends in background European air mainly reflect the strength of primary diffusive emissions of these compounds and subsequently their ongoing declines. The direct evidence for this is similar rates of decline at all the sites; similar rates of decline for all congeners; no systematic change in the fractionation pattern since 1994. The latest results indicate a reduction in the rate of decline for PCBs (and hence in primary emissions).

  6. Measurement of the reduction of terrestrial gamma-ray dose rates by the snow cover using TL-dosimeters

    International Nuclear Information System (INIS)

    Sakamoto, Ryuichi; Saito, Kimiaki; Nagaoka, Toshi; Tsutsumi, Masahiro; Moriuchi, Shigeru

    1990-12-01

    The objective of the investigation is to make clear the effect of the snow cover on environmental gamma-ray field. The reduction in the natural terrestrial gamma-ray dose rate due to snow cover was measured by TL-dosimeters. The measurements were performed in autumn before snowfall and in winter from September 1987 through March 1988 in Nagaoka city, Niigata prefecture. The dosimeters were set at four points, both outside and inside of the houses, for three months. The penetration factors (ratios of terrestrial gamma-ray dose accumulated during snow covered period to those during snow free period) were 0.54-0.67 in the open field, and 0.73-0.95 in the houses. According to theoretical calculation by the Monte Carlo method and the published snowfall data, the corresponding penetration factor was estimated at 0.54 in an ideal open field. As a result, the measured penetration factors were larger than calculated one by 24 % at maximum. The variation of dose rate inside houses by the difference of the amount of snow fall has been investigated. In general, though the amount of snow fall changes every year, dose rates inside the house were proved to be affected little by them. And, the optimum value of snow density which adapted for inference of penetration factor was found to be 0.3 g/cm 3 . The penetration factors inferred from snowdepth data for the year distributed between 0.6 and 1.0 in winter from November 1985 through April 1986 in Niigata prefecture. (author)

  7. Background Noise Reduction Using Adaptive Noise Cancellation Determined by the Cross-Correlation

    Science.gov (United States)

    Spalt, Taylor B.; Brooks, Thomas F.; Fuller, Christopher R.

    2012-01-01

    Background noise due to flow in wind tunnels contaminates desired data by decreasing the Signal-to-Noise Ratio. The use of Adaptive Noise Cancellation to remove background noise at measurement microphones is compromised when the reference sensor measures both background and desired noise. The technique proposed modifies the classical processing configuration based on the cross-correlation between the reference and primary microphone. Background noise attenuation is achieved using a cross-correlation sample width that encompasses only the background noise and a matched delay for the adaptive processing. A present limitation of the method is that a minimum time delay between the background noise and desired signal must exist in order for the correlated parts of the desired signal to be separated from the background noise in the crosscorrelation. A simulation yields primary signal recovery which can be predicted from the coherence of the background noise between the channels. Results are compared with two existing methods.

  8. Campath, calcineurin inhibitor reduction and chronic allograft nephropathy (3C) study: background, rationale, and study protocol

    Science.gov (United States)

    2013-01-01

    Background Kidney transplantation is the best treatment for patients with end-stage renal failure, but uncertainty remains about the best immunosuppression strategy. Long-term graft survival has not improved substantially, and one possible explanation is calcineurin inhibitor (CNI) nephrotoxicity. CNI exposure could be minimized by using more potent induction therapy or alternative maintenance therapy to remove CNIs completely. However, the safety and efficacy of such strategies are unknown. Methods/Design The Campath, Calcineurin inhibitor reduction and Chronic allograft nephropathy (3C) Study is a multicentre, open-label, randomized controlled trial with 852 participants which is addressing two important questions in kidney transplantation. The first question is whether a Campath (alemtuzumab)-based induction therapy strategy is superior to basiliximab-based therapy, and the second is whether, from 6 months after transplantation, a sirolimus-based maintenance therapy strategy is superior to tacrolimus-based therapy. Recruitment is complete, and follow-up will continue for around 5 years post-transplant. The primary endpoint for the induction therapy comparison is biopsy-proven acute rejection by 6 months, and the primary endpoint for the maintenance therapy comparison is change in estimated glomerular filtration rate from baseline to 2 years after transplantation. The study is sponsored by the University of Oxford and endorsed by the British Transplantation Society, and 18 centers for adult kidney transplant are participating. Discussion Late graft failure is a major issue for kidney-transplant recipients. If our hypothesis that minimizing CNI exposure with Campath-based induction therapy and/or an elective conversion to sirolimus-based maintenance therapy can improve long-term graft function and survival is correct, then patients should experience better graft function for longer. A positive outcome could change clinical practice in kidney transplantation. Trial

  9. A novel background reduction strategy for high level triggers and processing in gamma-ray Cherenkov detectors

    International Nuclear Information System (INIS)

    Cabras, G.; De Angelis, A.; De Lotto, B.; De Maria, M. M.; De Sabata, F.; Mansutti, O.; Frailis, M.; Persic, M.; Bigongiari, C.; Doro, M.; Mariotti, M.; Peruzzo, L.; Saggion, A.; Scalzotto, V.; Paoletti, R.; Scribano, A.; Turini, N.; Moralejo, A.; Tescaro, D.

    2008-01-01

    Gamma ray astronomy is now at the leading edge for studies related both to fundamental physics and astrophysics. The sensitivity of gamma detectors is limited by the huge amount of background, constituted by hadronic cosmic rays (typically two to three orders of magnitude more than the signal) and by the accidental background in the detectors. By using the information on the temporal evolution of the Cherenkov light, the background can be reduced. We will present here the results obtained within the MAGIC experiment using a new technique for the reduction of the background. Particle showers produced by gamma rays show a different temporal distribution with respect to showers produced by hadrons; the background due to accidental counts shows no dependence on time. Such novel strategy can increase the sensitivity of present instruments

  10. Reduction of Background Noise in the NASA Ames 40- by 80-Foot Wind Tunnel

    Science.gov (United States)

    Jaeger, Stephen M.; Allen, Christopher S.; Soderman, Paul T.; Olson, Larry E. (Technical Monitor)

    1995-01-01

    Background noise in both open-jet and closed wind tunnels adversely affects the signal-to-noise ratio of acoustic measurements. To measure the noise of increasingly quieter aircraft models, the background noise will have to be reduced by physical means or through signal processing. In a closed wind tunnel, such as the NASA Ames 40- by 80- Foot Wind Tunnel, the principle background noise sources can be classified as: (1) fan drive noise; (2) microphone self-noise; (3) aerodynamically induced noise from test-dependent hardware such as model struts and junctions; and (4) noise from the test section walls and vane set. This paper describes the steps taken to minimize the influence of each of these background noise sources in the 40 x 80.

  11. Reduction of Compton background from hydrogen in prompt gamma-ray analysis by multiple photon detection

    International Nuclear Information System (INIS)

    Toh, Y.; Oshima, M.; Kimura, A.; Koizumi, M.; Furutaka, K.; Hatsukawa, Y.

    2008-01-01

    Low-energy photons produced by the Compton scattering from hydrogen increase the background in the lower-energy region of the gamma-ray spectrum. This results in an increase in the detection limit for trace elements. In multiple photon detection prompt gamma-ray analysis (MPGA), only those elements that simultaneously emit two or more prompt gamma-rays, which have cascade relation and are emitted within a short interval, can be measured. Therefore, the influence of hydrogen can be reduced. In this study, standard polymer and food samples are measured. The hydrogen background is reduced in MPGA. (author)

  12. Objective Measures of Listening Effort: Effects of Background Noise and Noise Reduction

    Science.gov (United States)

    Sarampalis, Anastasios; Kalluri, Sridhar; Edwards, Brent; Hafter, Ervin

    2009-01-01

    Purpose: This work is aimed at addressing a seeming contradiction related to the use of noise-reduction (NR) algorithms in hearing aids. The problem is that although some listeners claim a subjective improvement from NR, it has not been shown to improve speech intelligibility, often even making it worse. Method: To address this, the hypothesis…

  13. Reduction of combinatorical background in the mass spectrum of electron pairs

    International Nuclear Information System (INIS)

    Tonse, S.

    1992-01-01

    Among the aims of the PHENIX experiment are the identification and measurement of the properties of the ρ, ω, φ and J/ψ vector mesons that have decayed through the e + e - channel. The main obstacle to identifying vector mesons (VM) using the e + e - invariant mass, is the significant number of e + and e - from other sources, which causes a large combinatorical background in the invariant mass spectrum. The work we have done aims to reduce this background by identifying background sources through kinematical cuts and removing them along with their combinatorical effects, while at the same time preserving as much as possible of the signal, i.e. the electrons from VM decay. A measurement of electron pairs (e + and e - ) from π-π and q bar q thermal sources is also a possibility, and a clear identification of the ''easier'' vector mesons (ω, φ) will be an indication of how well the thermal measurement can be done. To determine the nature and values of the kinematical cuts we have used a computer simulation to generate particles according to predetermined phase-space (rapidity and P T ) and multiplicity distributions

  14. Reduction of background noise induced by wind tunnel jet exit vanes

    Science.gov (United States)

    Martin, R. M.; Brooks, T. F.; Hoad, D. R.

    1985-01-01

    The NASA-Langley 4 x 7 m wind tunnel develops low frequency flow pulsations at certain velocity ranges during open throat mode operation, affecting the aerodynamics of the flow and degrading the resulting model test data. Triangular vanes attached to the trailing edge of flat steel rails, mounted 10 cm from the inside of the jet exit walls, have been used to reduce this effect; attention is presently given to methods used to reduce the inherent noise generation of the vanes while retaining their pulsation reduction features.

  15. Reduction of radioactive backgrounds in electroformed copper for ultra-sensitive radiation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hoppe, E.W., E-mail: eric.hoppe@pnnl.gov [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Aalseth, C.E.; Farmer, O.T.; Hossbach, T.W.; Liezers, M.; Miley, H.S.; Overman, N.R. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Reeves, J.H. [Reeves and Son LLC, 10 Albert Ave., Richland, WA 99352 (United States)

    2014-11-11

    Ultra-pure construction materials are required for the next generation of neutrino physics, dark matter and environmental science applications. These materials are also important for use in high-purity germanium spectrometers used in screening materials for radiopurity. The next-generation science applications require materials with radiopurity levels at or below 1 μBq/kg {sup 232}Th and {sup 238}U. Yet radiometric analysis lacks sensitivity below ∼10 μBq/kg for the U and Th decay chains. This limits both the selection of clean materials and the validation of purification processes. Copper is an important high-purity material for low-background experiments due to the ease with which it can be purified by electrochemical methods. Electroplating for purification into near-final shapes, known as electroforming, is one such method. Continued refinement of the copper electroforming process is underway, for the first time guided by an ICP-MS based assay method that can measure {sup 232}Th and {sup 238}U near the desired purity levels. An assay of electroformed copper at a μBq/kg level has been achieved and is described. The implications of electroformed copper at or better than this purity on next-generation low-background experiments are discussed.

  16. Background reduction at low energies with BEGe detector operated in liquid argon using the GERDA-LArGe facility

    Energy Technology Data Exchange (ETDEWEB)

    Budjas, Dusan [Physik-Department E15, Technische Universitaet Muenchen (Germany); Collaboration: GERDA-Collaboration

    2014-07-01

    LArGe is a low background test facility used for proving innovative approaches to background reduction in support of the neutrinoless double beta decay experiment Gerda. These approaches include an anti-Compton veto using scintillation light detection from liquid argon, as well as a novel pulse shape discrimination method exploiting the characteristic electrical field distribution inside BEGe detectors. The latter technique can identify single-site events (typical for double beta decays) and efficiently reject multi-site events (typical for backgrounds from gamma-ray interactions), as well as different types of background events from detector surfaces. While the main focus of the LArGe facility is to assist with reaching the goal of Gerda - improving the sensitivity for {sup 76}Ge neutrinoless double beta decay search, reducing the background at low energies and lowering the energy threshold is also of interest. In particular such efforts can be potentially relevant for search of dark matter or low energy neutrino interactions. In this talk I present the experimental measurement of the low energy region with a BEGe detector operated in LArGe with the application of powerful background suppression methods. The performance will be compared to that of some dedicated dark matter detection experiments.

  17. Quenching methods for background reduction in luminescence-based probe-target binding assays

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Hong [Los Alamos, NM; Goodwin, Peter M [Los Alamos, NM; Keller, Richard A [Los Alamos, NM; Nolan, Rhiannon L [Santa Fe, NM

    2007-04-10

    Background luminescence is reduced from a solution containing unbound luminescent probes, each having a first molecule that attaches to a target molecule and having an attached luminescent moiety, and luminescent probe/target adducts. Quenching capture reagent molecules are formed that are capable of forming an adduct with the unbound luminescent probes and having an attached quencher material effective to quench luminescence of the luminescent moiety. The quencher material of the capture reagent molecules is added to a solution of the luminescent probe/target adducts and binds in a proximity to the luminescent moiety of the unbound luminescent probes to quench luminescence from the luminescent moiety when the luminescent moiety is exposed to exciting illumination. The quencher capture reagent does not bind to probe molecules that are bound to target molecules and the probe/target adduct emission is not quenched.

  18. Objective measures of listening effort: effects of background noise and noise reduction.

    Science.gov (United States)

    Sarampalis, Anastasios; Kalluri, Sridhar; Edwards, Brent; Hafter, Ervin

    2009-10-01

    This work is aimed at addressing a seeming contradiction related to the use of noise-reduction (NR) algorithms in hearing aids. The problem is that although some listeners claim a subjective improvement from NR, it has not been shown to improve speech intelligibility, often even making it worse. To address this, the hypothesis tested here is that the positive effects of NR might be to reduce cognitive effort directed toward speech reception, making it available for other tasks. Normal-hearing individuals participated in 2 dual-task experiments, in which 1 task was to report sentences or words in noise set to various signal-to-noise ratios. Secondary tasks involved either holding words in short-term memory or responding in a complex visual reaction-time task. At low values of signal-to-noise ratio, although NR had no positive effect on speech reception thresholds, it led to better performance on the word-memory task and quicker responses in visual reaction times. Results from both dual tasks support the hypothesis that NR reduces listening effort and frees up cognitive resources for other tasks. Future hearing aid research should incorporate objective measurements of cognitive benefits.

  19. New method of 85Kr reduction in a noble gas based low-background detector

    Science.gov (United States)

    Akimov, D. Yu.; Bolozdynya, A. I.; Burenkov, A. A.; Hall, C.; Kovalenko, A. G.; Kuzminov, V. V.; Simakov, G. E.

    2017-04-01

    Krypton-85 is an anthropogenic beta-decaying isotope which produces low energy backgrounds in dark matter and neutrino experiments, especially those based upon liquid xenon. Several technologies have been developed to reduce the Kr concentration in such experiments. We propose to augment those separation technologies by first adding to the xenon an 85Kr-free sample of krypton in an amount much larger than the natural krypton that is already present. After the purification system reduces the total Kr concentration to the same level, the final 85Kr concentration will be reduced even further by the dilution factor. A test cell for measurement of the activity of various Kr samples has been assembled, and the activity of 25-year-old krypton has been measured. The measured activity agrees well with the expected activity accounting for the 85Kr abundance of the earth's atmosphere in 1990 and the half-life of the isotope. Additional tests with a Kr sample produced in the year 1944 (before the atomic era) have been done in order to demonstrate the sensitivity of the test cell.

  20. New method of 85Kr reduction in a noble gas based low-background detector

    International Nuclear Information System (INIS)

    Akimov, D.Yu.; Burenkov, A.A.; Kovalenko, A.G.; Simakov, G.E.; Bolozdynya, A.I.; Hall, C.; Kuzminov, V.V.

    2017-01-01

    Krypton-85 is an anthropogenic beta-decaying isotope which produces low energy backgrounds in dark matter and neutrino experiments, especially those based upon liquid xenon. Several technologies have been developed to reduce the Kr concentration in such experiments. We propose to augment those separation technologies by first adding to the xenon an 85 Kr-free sample of krypton in an amount much larger than the natural krypton that is already present. After the purification system reduces the total Kr concentration to the same level, the final 85 Kr concentration will be reduced even further by the dilution factor. A test cell for measurement of the activity of various Kr samples has been assembled, and the activity of 25-year-old krypton has been measured. The measured activity agrees well with the expected activity accounting for the 85 Kr abundance of the earth's atmosphere in 1990 and the half-life of the isotope. Additional tests with a Kr sample produced in the year 1944 (before the atomic era) have been done in order to demonstrate the sensitivity of the test cell.

  1. A Dynamic Enhancement With Background Reduction Algorithm: Overview and Application to Satellite-Based Dust Storm Detection

    Science.gov (United States)

    Miller, Steven D.; Bankert, Richard L.; Solbrig, Jeremy E.; Forsythe, John M.; Noh, Yoo-Jeong; Grasso, Lewis D.

    2017-12-01

    This paper describes a Dynamic Enhancement Background Reduction Algorithm (DEBRA) applicable to multispectral satellite imaging radiometers. DEBRA uses ancillary information about the clear-sky background to reduce false detections of atmospheric parameters in complex scenes. Applied here to the detection of lofted dust, DEBRA enlists a surface emissivity database coupled with a climatological database of surface temperature to approximate the clear-sky equivalent signal for selected infrared-based multispectral dust detection tests. This background allows for suppression of false alarms caused by land surface features while retaining some ability to detect dust above those problematic surfaces. The algorithm is applicable to both day and nighttime observations and enables weighted combinations of dust detection tests. The results are provided quantitatively, as a detection confidence factor [0, 1], but are also readily visualized as enhanced imagery. Utilizing the DEBRA confidence factor as a scaling factor in false color red/green/blue imagery enables depiction of the targeted parameter in the context of the local meteorology and topography. In this way, the method holds utility to both automated clients and human analysts alike. Examples of DEBRA performance from notable dust storms and comparisons against other detection methods and independent observations are presented.

  2. Homoacetogenesis in Deep-Sea Chloroflexi, as Inferred by Single-Cell Genomics, Provides a Link to Reductive Dehalogenation in Terrestrial Dehalococcoidetes.

    Science.gov (United States)

    Sewell, Holly L; Kaster, Anne-Kristin; Spormann, Alfred M

    2017-12-19

    The deep marine subsurface is one of the largest unexplored biospheres on Earth and is widely inhabited by members of the phylum Chloroflexi In this report, we investigated genomes of single cells obtained from deep-sea sediments of the Peruvian Margin, which are enriched in such Chloroflexi 16S rRNA gene sequence analysis placed two of these single-cell-derived genomes (DscP3 and Dsc4) in a clade of subphylum I Chloroflexi which were previously recovered from deep-sea sediment in the Okinawa Trough and a third (DscP2-2) as a member of the previously reported DscP2 population from Peruvian Margin site 1230. The presence of genes encoding enzymes of a complete Wood-Ljungdahl pathway, glycolysis/gluconeogenesis, a Rhodobacter nitrogen fixation (Rnf) complex, glyosyltransferases, and formate dehydrogenases in the single-cell genomes of DscP3 and Dsc4 and the presence of an NADH-dependent reduced ferredoxin:NADP oxidoreductase (Nfn) and Rnf in the genome of DscP2-2 imply a homoacetogenic lifestyle of these abundant marine Chloroflexi We also report here the first complete pathway for anaerobic benzoate oxidation to acetyl coenzyme A (CoA) in the phylum Chloroflexi (DscP3 and Dsc4), including a class I benzoyl-CoA reductase. Of remarkable evolutionary significance, we discovered a gene encoding a formate dehydrogenase (FdnI) with reciprocal closest identity to the formate dehydrogenase-like protein (complex iron-sulfur molybdoenzyme [CISM], DET0187) of terrestrial Dehalococcoides/Dehalogenimonas spp. This formate dehydrogenase-like protein has been shown to lack formate dehydrogenase activity in Dehalococcoides/Dehalogenimonas spp. and is instead hypothesized to couple HupL hydrogenase to a reductive dehalogenase in the catabolic reductive dehalogenation pathway. This finding of a close functional homologue provides an important missing link for understanding the origin and the metabolic core of terrestrial Dehalococcoides/Dehalogenimonas spp. and of reductive

  3. Homoacetogenesis in Deep-Sea Chloroflexi, as Inferred by Single-Cell Genomics, Provides a Link to Reductive Dehalogenation in Terrestrial Dehalococcoidetes

    Directory of Open Access Journals (Sweden)

    Holly L. Sewell

    2017-12-01

    Full Text Available The deep marine subsurface is one of the largest unexplored biospheres on Earth and is widely inhabited by members of the phylum Chloroflexi. In this report, we investigated genomes of single cells obtained from deep-sea sediments of the Peruvian Margin, which are enriched in such Chloroflexi. 16S rRNA gene sequence analysis placed two of these single-cell-derived genomes (DscP3 and Dsc4 in a clade of subphylum I Chloroflexi which were previously recovered from deep-sea sediment in the Okinawa Trough and a third (DscP2-2 as a member of the previously reported DscP2 population from Peruvian Margin site 1230. The presence of genes encoding enzymes of a complete Wood-Ljungdahl pathway, glycolysis/gluconeogenesis, a Rhodobacter nitrogen fixation (Rnf complex, glyosyltransferases, and formate dehydrogenases in the single-cell genomes of DscP3 and Dsc4 and the presence of an NADH-dependent reduced ferredoxin:NADP oxidoreductase (Nfn and Rnf in the genome of DscP2-2 imply a homoacetogenic lifestyle of these abundant marine Chloroflexi. We also report here the first complete pathway for anaerobic benzoate oxidation to acetyl coenzyme A (CoA in the phylum Chloroflexi (DscP3 and Dsc4, including a class I benzoyl-CoA reductase. Of remarkable evolutionary significance, we discovered a gene encoding a formate dehydrogenase (FdnI with reciprocal closest identity to the formate dehydrogenase-like protein (complex iron-sulfur molybdoenzyme [CISM], DET0187 of terrestrial Dehalococcoides/Dehalogenimonas spp. This formate dehydrogenase-like protein has been shown to lack formate dehydrogenase activity in Dehalococcoides/Dehalogenimonas spp. and is instead hypothesized to couple HupL hydrogenase to a reductive dehalogenase in the catabolic reductive dehalogenation pathway. This finding of a close functional homologue provides an important missing link for understanding the origin and the metabolic core of terrestrial Dehalococcoides/Dehalogenimonas spp. and of

  4. Background field removal technique using regularization enabled sophisticated harmonic artifact reduction for phase data with varying kernel sizes.

    Science.gov (United States)

    Kan, Hirohito; Kasai, Harumasa; Arai, Nobuyuki; Kunitomo, Hiroshi; Hirose, Yasujiro; Shibamoto, Yuta

    2016-09-01

    An effective background field removal technique is desired for more accurate quantitative susceptibility mapping (QSM) prior to dipole inversion. The aim of this study was to evaluate the accuracy of regularization enabled sophisticated harmonic artifact reduction for phase data with varying spherical kernel sizes (REV-SHARP) method using a three-dimensional head phantom and human brain data. The proposed REV-SHARP method used the spherical mean value operation and Tikhonov regularization in the deconvolution process, with varying 2-14mm kernel sizes. The kernel sizes were gradually reduced, similar to the SHARP with varying spherical kernel (VSHARP) method. We determined the relative errors and relationships between the true local field and estimated local field in REV-SHARP, VSHARP, projection onto dipole fields (PDF), and regularization enabled SHARP (RESHARP). Human experiment was also conducted using REV-SHARP, VSHARP, PDF, and RESHARP. The relative errors in the numerical phantom study were 0.386, 0.448, 0.838, and 0.452 for REV-SHARP, VSHARP, PDF, and RESHARP. REV-SHARP result exhibited the highest correlation between the true local field and estimated local field. The linear regression slopes were 1.005, 1.124, 0.988, and 0.536 for REV-SHARP, VSHARP, PDF, and RESHARP in regions of interest on the three-dimensional head phantom. In human experiments, no obvious errors due to artifacts were present in REV-SHARP. The proposed REV-SHARP is a new method combined with variable spherical kernel size and Tikhonov regularization. This technique might make it possible to be more accurate backgroud field removal and help to achive better accuracy of QSM. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. A novel background reduction strategy for high level triggers and processing in gamma-ray Cherenkov detectors

    OpenAIRE

    Cabras, G.; De Angelis, A.; De Lotto, B.; De Maria, M. M.; De Sabata, F.; Mansutti, O.; Frailis, M.; Persic, M.; Bigongiari, C.; Doro, M.; Mariotti, M.; Peruzzo, L.; Saggion, A.; Scalzotto, V.; Paoletti, R.

    2008-01-01

    Gamma ray astronomy is now at the leading edge for studies related both to fundamental physics and astrophysics. The sensitivity of gamma detectors is limited by the huge amount of background, constituted by hadronic cosmic rays (typically two to three orders of magnitude more than the signal) and by the accidental background in the detectors. By using the information on the temporal evolution of the Cherenkov light, the background can be reduced. We will present here the results obtained wit...

  6. Terrestrial gamma dose rate, radioactivity and radiological hazards in the rocks of an elevated radiation background in Juban District, Ad Dali' Governorate, Yemen.

    Science.gov (United States)

    Abdurabu, Wedad Ali; Ramli, Ahmad Termizi; Saleh, Muneer Aziz; Heryansyah, Arien; Alnhary, Anees; Fadhl, Shadi

    2016-03-01

    This study aims to evaluate natural radiation and radioactivity in the rock and to assess the corresponding health risk in a region of elevated background radiation in Juban District, Ad Dali' Governorate, Yemen. The mean external gamma dose rate was 374 nGy h(-1) which is approximately six times the world average. The measured results were used to compute annual effective dose equivalent, collective effective dose and excess lifetime cancer risk, which are 2.298 mSv, 61.95 man Sv y(-1) and 8.043  ×  10(-3), respectively. Rocks samples from different geological formations were analyzed for quantitative determination of (226)Ra, (232)Th and (40)K. The specific activity of the rocks samples ranges from 7  ±  1 Bq Kg(-1) to 12 513  ±  329 Bq Kg(-1) for (232)Th, from 6  ±  1 Bq kg(-1) to 3089  ±  74 Bq kg(-1) for (226)Ra and 702  ±  69 Bq kg(-1) to 2954  ±  285 Bq kg(-1) for (40)K. (232)Th is the main contributor to gamma dose rate from the rock samples. Indicators of radiological health impact, radium equivalent activity and external hazard index are 3738 Bq kg(-1) and 10.10, respectively. The mean external hazard index was ten times unity in the studied locations in Juban District, which is higher than the recommended value.

  7. Fast neutron spectrometry by bolometers lithium target for the reduction of background experiences of direct detection of dark matter

    International Nuclear Information System (INIS)

    Gironnet, J.

    2010-01-01

    Fast neutron spectrometry is a common interest for both direct dark matter detection and for nuclear research centres. Fast neutrons are usually detected indirectly. Neutrons are first slowed down by moderating materials for being detected in low energy range. Nevertheless, these detection techniques are and are limited in energy resolution. A new kind of fast neutron spectroscopy has been developed at the Institut d'Astrophysique Spatiale (IAS) in the aim of having a better knowledge of neutron backgrounds by the association of the bolometric technique with neutron sensitive crystals containing Li. Lithium-6 is indeed an element which has one the highest cross section for neutron capture with the 6 Li(n,α) 3 H reaction. This reaction releases 4,78 MeV tagging energetically each neutron capture. In particular for fast neutrons, the total energy measured by the bolometer would be the sum of this energy reaction and of the incoming fast neutron energy. To validate this principle, a spectrometer for fast neutrons, compact and semi-transportable, was built in IAS. This cryogenic detector, operated at 300 - 400 mK, consists of a 0.5 g LiF 95% 6 Li enriched crystal read out by a NTD-Ge sensor. This PhD thesis was on the study of the spectrometer characteristics, from the first measurements at IAS, to the measurements in the nuclear research centre of the Paul Scherrer Institute (PSI) until the final calibration with the Amande instrument of the Institut de Radioprotection et de Surete Nucleaire (IRSN). (author)

  8. 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)

  9. HARLIE 3-D Aerosol Backscatter and Wind Profile Measurements During Recent Field Experiments: Background Noise Reduction with a Fabry-Perot Etalon Filter in the HARLIE System

    Science.gov (United States)

    Lee, Sangwoo; Miller, David O.; Schwemmer, Geary; Wilkerson, Thomas D.; Andrus, Ionio; Egbert, Cameron; Anderson, Mark; Starr, David OC. (Technical Monitor)

    2002-01-01

    Background noise reduction of War signals is one of the most important factors in achieving better signal to noise ratio and precise atmospheric data from Mar measurements. Fahey Perot etalons have been used in several lidar systems as narrow band pass filters in the reduction of scattered sunlight. An slalom with spectral bandwidth, (Delta)v=0.23/cm, free spectral range, FSR=6.7/cm, and diameter, d=24mm was installed in a fiber coupled box which included a 500 pm bandwidth interference Filter. The slalom box couples the telescope and detector with 200 pm core fibers and 21 mm focal length collimators. The angular magnification is M=48. The etalon box was inserted into the Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE) system and tested during the HARGLO-2 intercomparison campaign conducted in November 2001 at Wallops Island, Virginia. This paper presents the preliminary test results of the slalom and a complete analysis will be presented at the conference.

  10. 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

  11. 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.

  12. The coincidence counting technique for orders of magnitude background reduction in data obtained with the magnetic recoil spectrometer at OMEGA and the NIF

    International Nuclear Information System (INIS)

    Casey, D. T.; Frenje, J. A.; Seguin, F. H.; Li, C. K.; Rosenberg, M. J.; Rinderknecht, H.; Manuel, M. J.-E.; Gatu Johnson, M.; Schaeffer, J. C.; Frankel, R.; Sinenian, N.; Childs, R. A.; Petrasso, R. D.; Glebov, V. Yu.; Sangster, T. C.; Burke, M.; Roberts, S.

    2011-01-01

    A magnetic recoil spectrometer (MRS) has been built and successfully used at OMEGA for measurements of down-scattered neutrons (DS-n), from which an areal density in both warm-capsule and cryogenic-DT implosions have been inferred. Another MRS is currently being commissioned on the National Ignition Facility (NIF) for diagnosing low-yield tritium-hydrogen-deuterium implosions and high-yield DT implosions. As CR-39 detectors are used in the MRS, the principal sources of background are neutron-induced tracks and intrinsic tracks (defects in the CR-39). The coincidence counting technique was developed to reduce these types of background tracks to the required level for the DS-n measurements at OMEGA and the NIF. Using this technique, it has been demonstrated that the number of background tracks is reduced by a couple of orders of magnitude, which exceeds the requirement for the DS-n measurements at both facilities.

  13. The coincidence counting technique for orders of magnitude background reduction in data obtained with the magnetic recoil spectrometer at OMEGA and the NIF.

    Science.gov (United States)

    Casey, D T; Frenje, J A; Séguin, F H; Li, C K; Rosenberg, M J; Rinderknecht, H; Manuel, M J-E; Gatu Johnson, M; Schaeffer, J C; Frankel, R; Sinenian, N; Childs, R A; Petrasso, R D; Glebov, V Yu; Sangster, T C; Burke, M; Roberts, S

    2011-07-01

    A magnetic recoil spectrometer (MRS) has been built and successfully used at OMEGA for measurements of down-scattered neutrons (DS-n), from which an areal density in both warm-capsule and cryogenic-DT implosions have been inferred. Another MRS is currently being commissioned on the National Ignition Facility (NIF) for diagnosing low-yield tritium-hydrogen-deuterium implosions and high-yield DT implosions. As CR-39 detectors are used in the MRS, the principal sources of background are neutron-induced tracks and intrinsic tracks (defects in the CR-39). The coincidence counting technique was developed to reduce these types of background tracks to the required level for the DS-n measurements at OMEGA and the NIF. Using this technique, it has been demonstrated that the number of background tracks is reduced by a couple of orders of magnitude, which exceeds the requirement for the DS-n measurements at both facilities.

  14. 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.

  15. Background Material

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Hyytiäinen, Kari; Saraiva, Sofia

    This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders.......This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders....

  16. A retention-time-shift-tolerant background subtraction and noise reduction algorithm (BgS-NoRA) for extraction of drug metabolites in liquid chromatography/mass spectrometry data from biological matrices.

    Science.gov (United States)

    Zhu, Peijuan; Ding, Wei; Tong, Wei; Ghosal, Anima; Alton, Kevin; Chowdhury, Swapan

    2009-06-01

    A retention-time-shift-tolerant background subtraction and noise reduction algorithm (BgS-NoRA) is implemented using the statistical programming language R to remove non-drug-related ion signals from accurate mass liquid chromatography/mass spectrometry (LC/MS) data. The background-subtraction part of the algorithm is similar to a previously published procedure (Zhang H and Yang Y. J. Mass Spectrom. 2008, 43: 1181-1190). The noise reduction algorithm (NoRA) is an add-on feature to help further clean up the residual matrix ion noises after background subtraction. It functions by removing ion signals that are not consistent across many adjacent scans. The effectiveness of BgS-NoRA was examined in biological matrices by spiking blank plasma extract, bile and urine with diclofenac and ibuprofen that have been pre-metabolized by microsomal incubation. Efficient removal of background ions permitted the detection of drug-related ions in in vivo samples (plasma, bile, urine and feces) obtained from rats orally dosed with (14)C-loratadine with minimal interference. Results from these experiments demonstrate that BgS-NoRA is more effective in removing analyte-unrelated ions than background subtraction alone. NoRA is shown to be particularly effective in the early retention region for urine samples and middle retention region for bile samples, where the matrix ion signals still dominate the total ion chromatograms (TICs) after background subtraction. In most cases, the TICs after BgS-NoRA are in excellent qualitative correlation to the radiochromatograms. BgS-NoRA will be a very useful tool in metabolite detection and identification work, especially in first-in-human (FIH) studies and multiple dose toxicology studies where non-radio-labeled drugs are administered. Data from these types of studies are critical to meet the latest FDA guidance on Metabolite in Safety Testing (MIST). Copyright (c) 2009 John Wiley & Sons, Ltd.

  17. Background reduction of the KATRIN spectrometers. Transmission function of the pre-spectrometer and systematic tests of the main-spectrometer wire electrode

    Energy Technology Data Exchange (ETDEWEB)

    Prall, Matthias

    2011-07-04

    The KArlsruhe TRItium Neutrino experiment, KATRIN will determine the mass of the anti {nu}{sub e} with a sensitivity of 0.2 eV (90% C.L.) via a measurement of the {beta}-spectrum of tritium decaying in a windowless gaseous molecular tritium source near its endpoint of 18.57 keV. This approach relies exclusively on the relativistic kinematics of the decay products rendering the experiment model independent and reducing the systematic uncertainty. An ultra-low background of a few mHz and an energy resolution of 0.93 eV are among the requirements to reach the sensitivity. These demands are fulfilled with the main spectrometer (MS). While the {beta}-decay electrons are guided by a magnetic field through the experiment, the MS acts as a high-pass filter for the {beta}-decay electrons. Only those above an energy barrier, the retarding potential, are transmitted to the detector. The last about 30 eV of the T{sub 2} {beta}-spectrum will be scanned in this way. The MS is equipped with a 650 m{sup 2}, two-layered, UHV compatible and quasi-massless wire electrode suppressing secondary electron background originating at the main-spectrometer walls and caused by residual radioactivity and cosmic muons. Its energy resolution of 0.93 eV is only achieved, if a large part of the 248 wire electrode modules, which determine the electric field inside the MS, has a mechanical precision of 0.2 mm. Not a single of the about 28.000 wires of the electrode must break during the lifetime of KATRIN. A 2-dimensional laser sensor for contact-less position (precision about 0.01 mm) and tension (precision about 0.04 N) measurements was developed and applied, to firstly, verify the mechanical precision of the electrode modules and secondly, to examine their reliability. A 3-dimensional coordinate measurement table was automated to perform these measurements in a clean room. This table was also used to verify the precision of components using a camera system and image recognition methods (0.05 mm

  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. Infrared variation reduction by simultaneous background suppression and target contrast enhancement for deep convolutional neural network-based automatic target recognition

    Science.gov (United States)

    Kim, Sungho

    2017-06-01

    Automatic target recognition (ATR) is a traditionally challenging problem in military applications because of the wide range of infrared (IR) image variations and the limited number of training images. IR variations are caused by various three-dimensional target poses, noncooperative weather conditions (fog and rain), and difficult target acquisition environments. Recently, deep convolutional neural network-based approaches for RGB images (RGB-CNN) showed breakthrough performance in computer vision problems, such as object detection and classification. The direct use of RGB-CNN to the IR ATR problem fails to work because of the IR database problems (limited database size and IR image variations). An IR variation-reduced deep CNN (IVR-CNN) to cope with the problems is presented. The problem of limited IR database size is solved by a commercial thermal simulator (OKTAL-SE). The second problem of IR variations is mitigated by the proposed shifted ramp function-based intensity transformation. This can suppress the background and enhance the target contrast simultaneously. The experimental results on the synthesized IR images generated by the thermal simulator (OKTAL-SE) validated the feasibility of IVR-CNN for military ATR applications.

  20. Background radiation

    International Nuclear Information System (INIS)

    Arnott, D.

    1985-01-01

    The effects of background radiation, whether natural or caused by man's activities, are discussed. The known biological effects of radiation in causing cancers or genetic mutations are explained. The statement that there is a threshold below which there is no risk is examined critically. (U.K.)

  1. 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...

  2. 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...

  3. 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.

  4. 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.

  5. Generation of terrestrial radiation database in the Larsemann Hills, Antarctica

    International Nuclear Information System (INIS)

    Pal, Rupali; Dhabekar, Bhushan; Jose, Jis Romal; Chinnaesakki, S.; Bakshi, A.K.; Datta, D.; Pradeepkumar, K.S.

    2018-01-01

    Natural background radiation in the environment includes terrestrial radiation, cosmic radiation from space and air activity due to radon/thoron. It is known that cosmic contribution increases near the poles. The terrestrial component is largely due to 232 Th and 238 U series and 40 K. BARC under the cosmic ray dosimetry project with National Centre for Antarctic and Ocean Research (NCAOR) has taken up measurement of natural background radiation at Larsemann Hills, Antarctica. The project includes generation of baseline data on terrestrial radioactivity in water, soil and rock and estimation of cosmic ray doses. Extensive radiation surveys were carried out by the BARC team in the 35 th and 36 th expedition in and around Larsemann hills in East Antarctica where the third Indian station 'Bharati' is situated. This paper presents mapping of terrestrial radiation levels in Antarctica which will help in strengthening the background radiation database and develop a Radiation Informatics System (RIS)

  6. The Solar-Terrestrial Environment

    Science.gov (United States)

    Hargreaves, John Keith

    1995-05-01

    The book begins with three introductory chapters that provide some basic physics and explain the principles of physical investigation. The principal material contained in the main part of the book covers the neutral and ionized upper atmosphere, the magnetosphere, and structures, dynamics, disturbances, and irregularities. The concluding chapter deals with technological applications. The account is introductory, at a level suitable for readers with a basic background in engineering or physics. The intent is to present basic concepts, and for that reason, the mathematical treatment is not complex. SI units are given throughout, with helpful notes on cgs units where these are likely to be encountered in the research literature. This book is suitable for advanced undergraduate and graduate students who are taking introductory courses on upper atmospheric, ionospheric, or magnetospheric physics. This is a successor to The Upper Atmosphere and Solar-Terrestrial Relations, published in 1979.

  7. 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.)

  8. 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.

  9. 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)

  10. 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

  11. 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.

  12. 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....

  13. 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...

  14. 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

  15. Radio Astronomy Explorer /RAE/. I - Observations of terrestrial radio noise.

    Science.gov (United States)

    Herman, J. R.; Caruso, J. A.; Stone, R. G.

    1973-01-01

    Radio Astronomy Explorer (RAE) I data are analyzed to establish characteristics of HF terrestrial radio noise at an altitude of about 6000 km. Time and frequency variations in amplitude of the observed noise well above cosmic noise background are explained on the basis of temporal and spatial variations in ionospheric critical frequency coupled with those in noise source distributions. It is shown that terrestrial radio noise regularly breaks through the ionosphere and reaches RAE with magnitudes 15 dB and more above cosmic noise background, on frequencies above the F-layer critical frequency.

  16. Research progress in airborne surveys of terrestrial gamma radiation

    International Nuclear Information System (INIS)

    Burson, Z.G.

    1974-01-01

    Progress during the last few years in airborne surveys of terrestrial gamma radiation, i.e. in the measuring, recording, and interpreting of gamma ray signals in NaI(Tl) crystals, is discussed. Non-terrestrial background contributions have been accurately characterized. The feasibility of determining the water equivalent of snow cover by aerial survey techniques has been demonstrated. Repeat surveys over areas surrounding reactor sites can now be used to detect average differences of less than 1.0 μR/hr in terrestrial gamma radiation levels. New data acquisition and recording systems allow isotope concentrations and total inventories to be measured in spatial resolutions of a few hundred feet. Aerial survey data have been combined with population distribution data to obtain population exposure values from natural terrestrial gamma radiation around reactor sites

  17. 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

  18. Radio Astronomy Explorer (RAE) 1 observations of terrestrial radio noise

    Science.gov (United States)

    Herman, J. R.; Caruso, J. A.

    1971-01-01

    Radio Astonomy Explorer (RAE) 1 data are analyzed to establish characteristics of HF terrestrial radio noise at an altitude of about 6000 km. Time and frequency variations in amplitude of the observed noise well above cosmic noise background are explained on the basis of temporal and spatial variations in ionospheric critical frequency coupled with those in noise source distributions. It is shown that terrestrial noise regularly breaks through the ionosphere and reaches RAE with magnitudes 15 or more db higher than cosmic noise background. Maximum terrestrial noise is observed when RAE is over the dark side of the Earth in the neighborhood of equatorial continental land masses where thunderstorms occur most frequently. The observed noise level is 30-40 db lower with RAE over oceans.

  19. 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

  20. 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)

  1. 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.)

  2. 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)

  3. 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...

  4. Consequences of simulating terrestrial N dynamics for projecting future terrestrial C storage

    Science.gov (United States)

    Zaehle, S.; Friend, A. D.; Friedlingstein, P.

    2009-04-01

    We present results of a new land surface model, O-CN, which includes a process-based coupling between the terrestrial cycling of energy, water, carbon, and nitrogen. The model represents the controls of the terrestrial nitrogen (N) cycling on carbon (C) pools and fluxes through photosynthesis, respiration, changes in allocation patterns, as well as soil organic matter decomposition, and explicitly accounts for N leaching and gaseous losses. O-CN has been shown to give realistic results in comparison to observations at a wide range of scales, including in situ flux measurements, productivity databases, and atmospheric CO2 concentration data. Notably, O-CN simulates realistic responses of net primary productivity, foliage area, and foliage N content to elevated atmospheric [CO2] as evidenced at free air carbon dioxide enrichment (FACE) sites (Duke, Oak Ridge). We re-examine earlier model-based assessments of the terrestrial C sequestration potential using a global transient O-CN simulation driven by increases in atmospheric [CO2], N deposition and climatic changes over the 21st century. We find that accounting for terrestrial N cycling about halves the potential to store C in response to increases in atmospheric CO2 concentrations; mainly due to a reduction of the net C uptake in temperate and boreal forests. Nitrogen deposition partially alleviates the effect of N limitation, but is by far not sufficient to compensate for the effect completely. These findings underline the importance of an accurate representation of nutrient limitations in future projections of the terrestrial net CO2 exchanges and therefore land-climate feedback studies.

  5. Visual interface for space and terrestrial analysis

    Science.gov (United States)

    Dombrowski, Edmund G.; Williams, Jason R.; George, Arthur A.; Heckathorn, Harry M.; Snyder, William A.

    1995-01-01

    The management of large geophysical and celestial data bases is now, more than ever, the most critical path to timely data analysis. With today's large volume data sets from multiple satellite missions, analysts face the task of defining useful data bases from which data and metadata (information about data) can be extracted readily in a meaningful way. Visualization, following an object-oriented design, is a fundamental method of organizing and handling data. Humans, by nature, easily accept pictorial representations of data. Therefore graphically oriented user interfaces are appealing, as long as they remain simple to produce and use. The Visual Interface for Space and Terrestrial Analysis (VISTA) system, currently under development at the Naval Research Laboratory's Backgrounds Data Center (BDC), has been designed with these goals in mind. Its graphical user interface (GUI) allows the user to perform queries, visualization, and analysis of atmospheric and celestial backgrounds data.

  6. Optimal Background Attenuation for Fielded Radiation Detection Systems

    International Nuclear Information System (INIS)

    Robinson, Sean M.; Kaye, William R.; Schweppe, John E.; Siciliano, Edward R.

    2006-01-01

    Radiation detectors are often placed in positions difficult to shield from the effects of terrestrial background. This is particularly true in the case of Radiation Portal Monitor (RPM) systems, as their wide viewing angle and outdoor installations make them susceptible to terrestrial background from the surrounding area. A low background is desired in most cases, especially when the background noise is of comparable strength to the signal of interest. The problem of shielding a generalized RPM from terrestrial background is considered. Various detector and shielding scenarios are modeled with the Monte-Carlo N Particle (MCNP) computer code. Amounts of nominal-density shielding needed to attenuate the terrestrial background to varying degrees are given, along with optimal shielding geometry to be used in areas where natural shielding is limited, and where radiation detection must occur in the presence of natural background. Common shielding solutions such as steel plating are evaluated based on the signal to noise ratio and the benefits are weighed against the incremental cost.

  7. Advective and diffusive dermal processes for estimating terrestrial amphibian pesticide exposure

    Science.gov (United States)

    Background/Question/Methods Dermal exposure presents a potentially significant but understudied route for pesticide uptake in terrestrial amphibians. Historically, evaluation of pesticide risk to both amphibians and reptiles has been achieved by comparing ingestion and inhalat...

  8. NOVANA. National Monitering and Assessment Programme for the Aquatic and Terrestrial Environments

    DEFF Research Database (Denmark)

    Svendsen, L. M.; Bijl, L. van der; Boutrup, S.

    This report is Part 2 of the Programme Description of NOVANA - the National Monitoring and Assessment Programme for the Aquatic and Terrestrial Environments. Part 2 comprises a de-tailed description of the nine NOVANA subprogrammes: Background monitoring of air......This report is Part 2 of the Programme Description of NOVANA - the National Monitoring and Assessment Programme for the Aquatic and Terrestrial Environments. Part 2 comprises a de-tailed description of the nine NOVANA subprogrammes: Background monitoring of air...

  9. Terrestrial radiation - an overview

    International Nuclear Information System (INIS)

    Hamilton, E.I.

    1989-01-01

    Some of the fundamental principles developed in geology and geochemistry are applied in an assessment of risk from the natural radiation environment. At present, in radiological protection, the contribution made by the Earthy Sciences is meagre and there is a need to improve this situation. Through a more precise understanding of the natural processes which control the distribution of radionuclides (of the naturally occurring uranium, thorium radioactive series and potassium-40) it is possible to provide a firmer scientific basis in order to account for the role that the natural radiation background plays in a consideration of radiological matters. Various examples are provided in order to illustrate this approach and a glossary of geological and other terms is provided. (author)

  10. An intercomparison of detectors for measurement of background radiation

    International Nuclear Information System (INIS)

    Nielsen, S.P.; Boetter-Jensen, L.

    1981-04-01

    Measurements of the background radiation were made in 1978 at 14 locations with a high-pressure ionization chamber, thermoluminiscence dosimeters (TLD's), two NaI(Tl) detectors, and a Ge(Li) spectrometer system. Simultaneous measurements with the ionization chamber and the spectrometer system provide reliable estimates of the total background exposure rate, of the individual contributors to the terrestrial exposure rate, and of the exposure rate from the secondary cosmic radiation. The TLD results agree with those of the ionization chamber. The NaI(Tl) detector results show that accurate estimates of the terrestrial exposure rate can be obtained if empirical corrections are applied. (author)

  11. Groundwater and Terrestrial Water Storage

    Science.gov (United States)

    Rodell, Matthew; Chambers, Don P.; Famiglietti, James S.

    2011-01-01

    Most people think of groundwater as a resource, but it is also a useful indicator of climate variability and human impacts on the environment. Groundwater storage varies slowly relative to other non-frozen components of the water cycle, encapsulating long period variations and trends in surface meteorology. On seasonal to interannual timescales, groundwater is as dynamic as soil moisture, and it has been shown that groundwater storage changes have contributed to sea level variations. Groundwater monitoring well measurements are too sporadic and poorly assembled outside of the United States and a few other nations to permit direct global assessment of groundwater variability. However, observational estimates of terrestrial water storage (TWS) variations from the GRACE satellites largely represent groundwater storage variations on an interannual basis, save for high latitude/altitude (dominated by snow and ice) and wet tropical (surface water) regions. A figure maps changes in mean annual TWS from 2009 to 2010, based on GRACE, reflecting hydroclimatic conditions in 2010. Severe droughts impacted Russia and the Amazon, and drier than normal weather also affected the Indochinese peninsula, parts of central and southern Africa, and western Australia. Groundwater depletion continued in northern India, while heavy rains in California helped to replenish aquifers that have been depleted by drought and withdrawals for irrigation, though they are still below normal levels. Droughts in northern Argentina and western China similarly abated. Wet weather raised aquifer levels broadly across western Europe. Rains in eastern Australia caused flooding to the north and helped to mitigate a decade long drought in the south. Significant reductions in TWS seen in the coast of Alaska and the Patagonian Andes represent ongoing glacier melt, not groundwater depletion. Figures plot time series of zonal mean and global GRACE derived non-seasonal TWS anomalies (deviation from the mean of

  12. Neutron background estimates in GESA

    Directory of Open Access Journals (Sweden)

    Fernandes A.C.

    2014-01-01

    Full Text Available The SIMPLE project looks for nuclear recoil events generated by rare dark matter scattering interactions. Nuclear recoils are also produced by more prevalent cosmogenic neutron interactions. While the rock overburden shields against (μ,n neutrons to below 10−8 cm−2 s−1, it itself contributes via radio-impurities. Additional shielding of these is similar, both suppressing and contributing neutrons. We report on the Monte Carlo (MCNP estimation of the on-detector neutron backgrounds for the SIMPLE experiment located in the GESA facility of the Laboratoire Souterrain à Bas Bruit, and its use in defining additional shielding for measurements which have led to a reduction in the extrinsic neutron background to ∼ 5 × 10−3 evts/kgd. The calculated event rate induced by the neutron background is ∼ 0,3 evts/kgd, with a dominant contribution from the detector container.

  13. 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

  14. Moving in the Anthropocene: Global reductions in terrestrial mammalian movements

    DEFF Research Database (Denmark)

    Tucker, Marlee A.; Böhning-Gaese, Katrin; Fagan, William F.

    2018-01-01

    Until the past century or so, the movement of wild animals was relatively unrestricted, and their travels contributed substantially to ecological processes. As humans have increasingly altered natural habitats, natural animal movements have been restricted. Tucker et al. examined GPS locations...

  15. 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

  16. 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.)

  17. 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.

  18. Radionuclides in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Howard, B.J.; Kennedy, V.H.; Nelson, A.

    1983-06-01

    A bibliographical database has been developed to provide quick access to research and background literature in the field of radioecology. This is a development of an earlier database described by Nelson (Bocock 1981). ITE's particular fields of interest have led to a subject bias in the bibliography towards studies in Cumbria, especially those concerned with radionuclides originating from the reprocessing plant at Sellafield, and towards ecological research studies that are complementary to radionuclide studies. Other subjects covered, include the chemistry of radionuclides, budgets and transfers within ecosystems and techniques for the analysis of environmental samples. ITE's research objectives have led to the establishment of a specialized database which is intended to complement rather than compete with the large international databases made available by suppliers such as IRS-DIALTECH or DIALOG. Currently the database holds about 1900 references which are stored on a 2 1/2 megabyte hard disk on a Digital PDP11/34 computer operating under a time shared system. The references follow a standard format. (author)

  19. Background sources at PEP

    International Nuclear Information System (INIS)

    Lynch, H.; Schwitters, R.F.; Toner, W.T.

    1988-01-01

    Important sources of background for PEP experiments are studied. Background particles originate from high-energy electrons and positrons which have been lost from stable orbits, γ-rays emitted by the primary beams through bremsstrahlung in the residual gas, and synchrotron radiation x-rays. The effect of these processes on the beam lifetime are calculated and estimates of background rates at the interaction region are given. Recommendations for the PEP design, aimed at minimizing background are presented. 7 figs., 4 tabs

  20. Cosmic Microwave Background Timeline

    Science.gov (United States)

    Cosmic Microwave Background Timeline 1934 : Richard Tolman shows that blackbody radiation in an will have a blackbody cosmic microwave background with temperature about 5 K 1955: Tigran Shmaonov anisotropy in the cosmic microwave background, this strongly supports the big bang model with gravitational

  1. Nonlinear Waves in the Terrestrial Quasiparallel Foreshock.

    Science.gov (United States)

    Hnat, B; Kolotkov, D Y; O'Connell, D; Nakariakov, V M; Rowlands, G

    2016-12-02

    We provide strongly conclusive evidence that the cubic nonlinearity plays an important part in the evolution of the large amplitude magnetic structures in the terrestrial foreshock. Large amplitude nonlinear wave trains at frequencies above the proton cyclotron frequency are identified after nonharmonic slow variations are filtered out by applying the empirical mode decomposition. Numerical solutions of the derivative nonlinear Schrödinger equation, predicted analytically by the use of a pseudopotential approach, are found to be consistent with the observed wave forms. The approximate phase speed of these nonlinear waves, indicated by the parameters of numerical solutions, is of the order of the local Alfvén speed. We suggest that the feedback of the large amplitude fluctuations on background plasma is reflected in the evolution of the pseudopotential.

  2. Regional and long-term patterns of lead concentrations in fluvial, marine and terrestrial systems and humans in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Hagner, C. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Hydrophysik

    2000-07-01

    Lead contamination of abiotic and biotic systems has been studied closely since the early 1970s, when lead was firstly perceived as an environmental problem. Lead emission reduction policies were implemented throughout Europe during that time. Nonetheless, analyses of lead loads in aquatic systems, such as the river Elbe, showed no decline over time in either suspended matter or surface sediments. Regional differences in lead concentrations of fluvial systems were found, due to tidal influence, runoff and local emissions. Lead contamination of sediments from the North Sea was highest in estuaries. Concentrations in sediment cores were quite stable down to the depth of background values, due to bioturbation, flow, waves and meandering channels. Terrestrial soils in Europe were highly polluted in industrial and ore mining areas and large cities. No decline in lead concentrations was evident in foraminifers, bladder wrack or fish. It was found that contamination in sediments, mammals and fish was higher in coastal zones than in the open sea. In contrast to in aquatic organisms, positive impacts of lead reduction regulations were detected in terrestrial plants, which adsorbed or took up lead mainly through atmospheric lead deposition. European lead concentrations in plants decreased coincidently with lead emissions. That trend could also be identified in the blood lead levels of the human population in Europe: since 1979 they have declined in every group of the population. Mainly influenced by age, sex and the living environment, overall, the lead loads of humans had never been high enough to cause health danger. (orig.)

  3. The Planetary Terrestrial Analogues Library (PTAL)

    Science.gov (United States)

    Werner, S. C.; Dypvik, H.; Poulet, F.; Rull Perez, F.; Bibring, J.-P.; Bultel, B.; Casanova Roque, C.; Carter, J.; Cousin, A.; Guzman, A.; Hamm, V.; Hellevang, H.; Lantz, C.; Lopez-Reyes, G.; Manrique, J. A.; Maurice, S.; Medina Garcia, J.; Navarro, R.; Negro, J. I.; Neumann, E. R.; Pilorget, C.; Riu, L.; Sætre, C.; Sansano Caramazana, A.; Sanz Arranz, A.; Sobron Grañón, F.; Veneranda, M.; Viennet, J.-C.; PTAL Team

    2018-04-01

    The Planetary Terrestrial Analogues Library project aims to build and exploit a spectral data base for the characterisation of the mineralogical and geological evolution of terrestrial planets and small solar system bodies.

  4. Terrestrial Steering Group. 2014. Arctic Terrestrial Biodiversity Monitoring Plan

    DEFF Research Database (Denmark)

    Aastrup, Peter; Aronsson, Mora; Barry, Tom

    capacity and information may be currently available and (b) to outline near-term required steps to begin implementing the plan and reporting on an initial set of Arctic terrestrial biodiversity focal ecosystem component attributes. The specific objectives of the workshop were to: Identify key products...... for TSG for the next two years. Identify key components of a pan-Arctic status report for priority focal ecosystem components (FEC) attributes for policy and decision makers. Develop a prioritized set of activities to meet reporting objectives. Identify key milestones and timelines for the successful...... implementation of the Arctic Terrestrial Biodiversity Monitoring Plan for the next two years. Identify expert networks required for successful implementation of the plan. Identify key gaps and opportunities for the TSG related to plan implementation and identify near-term next steps to address gaps....

  5. Optimal background matching camouflage.

    Science.gov (United States)

    Michalis, Constantine; Scott-Samuel, Nicholas E; Gibson, David P; Cuthill, Innes C

    2017-07-12

    Background matching is the most familiar and widespread camouflage strategy: avoiding detection by having a similar colour and pattern to the background. Optimizing background matching is straightforward in a homogeneous environment, or when the habitat has very distinct sub-types and there is divergent selection leading to polymorphism. However, most backgrounds have continuous variation in colour and texture, so what is the best solution? Not all samples of the background are likely to be equally inconspicuous, and laboratory experiments on birds and humans support this view. Theory suggests that the most probable background sample (in the statistical sense), at the size of the prey, would, on average, be the most cryptic. We present an analysis, based on realistic assumptions about low-level vision, that estimates the distribution of background colours and visual textures, and predicts the best camouflage. We present data from a field experiment that tests and supports our predictions, using artificial moth-like targets under bird predation. Additionally, we present analogous data for humans, under tightly controlled viewing conditions, searching for targets on a computer screen. These data show that, in the absence of predator learning, the best single camouflage pattern for heterogeneous backgrounds is the most probable sample. © 2017 The Authors.

  6. Measurements of Background Gamma Radiation on Some Localities of North-East Kosovo

    OpenAIRE

    , G. Hodolli; , Y. Halimi; , R. Gashi; , Se. Kadiri; , B. Xhafa; , A. Jonuzaj

    2016-01-01

    The measurement of natural environmental radiations is one of the most important subjects in health physics. The main sources of background radiation are cosmic, terrestrial and cosmogenic radiation produced by reactions with cosmic rays and atmospheric nuclei. Terrestrial radiation varies in different regions in the world. Generally the background dose rate from cosmic rays depends on the latitude and altitude. The dose rate range obtained in some northeast Kosovo, the dose rate varies from ...

  7. 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.

  8. Synthesis of Volumetric Ring Antenna Array for Terrestrial Coverage Pattern

    Directory of Open Access Journals (Sweden)

    Alberto Reyna

    2014-01-01

    Full Text Available This paper presents a synthesis of a volumetric ring antenna array for a terrestrial coverage pattern. This synthesis regards the spacing among the rings on the planes X-Y, the positions of the rings on the plane X-Z, and uniform and concentric excitations. The optimization is carried out by implementing the particle swarm optimization. The synthesis is compared with previous designs by resulting with proper performance of this geometry to provide an accurate coverage to be applied in satellite applications with a maximum reduction of the antenna hardware as well as the side lobe level reduction.

  9. Synthesis of Volumetric Ring Antenna Array for Terrestrial Coverage Pattern

    Science.gov (United States)

    Reyna, Alberto; Panduro, Marco A.; Del Rio Bocio, Carlos

    2014-01-01

    This paper presents a synthesis of a volumetric ring antenna array for a terrestrial coverage pattern. This synthesis regards the spacing among the rings on the planes X-Y, the positions of the rings on the plane X-Z, and uniform and concentric excitations. The optimization is carried out by implementing the particle swarm optimization. The synthesis is compared with previous designs by resulting with proper performance of this geometry to provide an accurate coverage to be applied in satellite applications with a maximum reduction of the antenna hardware as well as the side lobe level reduction. PMID:24701150

  10. Terrestrial invasion of pomatiopsid gastropods in the heavy-snow region of the Japanese Archipelago

    Directory of Open Access Journals (Sweden)

    Kato Makoto

    2011-05-01

    Full Text Available Abstract Background Gastropod mollusks are one of the most successful animals that have diversified in the fully terrestrial habitat. They have evolved terrestrial taxa in more than nine lineages, most of which originated during the Paleozoic or Mesozoic. The rissooidean gastropod family Pomatiopsidae is one of the few groups that have evolved fully terrestrial taxa during the late Cenozoic. The pomatiopsine diversity is particularly high in the Japanese Archipelago and the terrestrial taxa occur only in this region. In this study, we conducted thorough samplings of Japanese pomatiopsid species and performed molecular phylogenetic analyses to explore the patterns of diversification and terrestrial invasion. Results Molecular phylogenetic analyses revealed that Japanese Pomatiopsinae derived from multiple colonization of the Eurasian Continent and that subsequent habitat shifts from aquatic to terrestrial life occurred at least twice within two Japanese endemic lineages. Each lineage comprises amphibious and terrestrial species, both of which are confined to the mountains in heavy-snow regions facing the Japan Sea. The estimated divergence time suggested that diversification of these terrestrial lineages started in the Late Miocene, when active orogenesis of the Japanese landmass and establishment of snowy conditions began. Conclusions The terrestrial invasion of Japanese Pomatiopsinae occurred at least twice beside the mountain streamlets of heavy-snow regions, which is considered the first case of this event in the area. Because snow coverage maintains stable temperatures and high humidity on the ground surface, heavy-snow conditions may have paved the way for these organisms from freshwater to land via mountain streamlets by preventing winter desiccation in mountain valleys. The fact that the terrestrialization of Pomatiopsidae occurred only in year-round wet environments, but not in seasonally dried regions, provides new insight into ancient

  11. Global Warming and the Microwave Background

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2009-04-01

    Full Text Available In the work, the importance of assigning the microwave background to the Earth is ad- dressed while emphasizing the consequences for global climate change. Climate mod- els can only produce meaningful forecasts when they consider the real magnitude of all radiative processes. The oceans and continents both contribute to terrestrial emis- sions. However, the extent of oceanic radiation, particularly in the microwave region, raises concerns. This is not only since the globe is covered with water, but because the oceans themselves are likely to be weaker emitters than currently believed. Should the microwave background truly be generated by the oceans of the Earth, our planet would be a much less efficient emitter of radiation in this region of the electromagnetic spectrum. Furthermore, the oceans would appear unable to increase their emissions in the microwave in response to temperature elevation, as predicted by Stefan’s law. The results are significant relative to the modeling of global warming.

  12. Natural background radiation and population dose in China

    Energy Technology Data Exchange (ETDEWEB)

    Guangzhi, C. (Ministry of Public Health, Beijing, BJ (China)); Ziqiang, P.; Zhenyum, H.; Yin, Y.; Mingqiang, G.

    On the basis of analyzing the data for the natural background radiation level in China, the typical values for indoor and outdoor terrestrial gamma radiation and effective dose equivalents from radon and thoron daughters are recommended. The annual effective dose equivalent from natural radiation to the inhabitant is estimated to be 2.3 mSv, in which 0.54 mSv is from terrestrial gamma radiation and about 0,8 mSv is from radon and its short-lived daughters. 55 Refs.

  13. Cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Wilson, R.W.

    1979-01-01

    The 20-ft horn-reflector antenna at Bell Laboratories is discussed in detail with emphasis on the 7.35 cm radiometer. The circumstances leading to the detection of the cosmic microwave background radiation are explored

  14. Zambia Country Background Report

    DEFF Research Database (Denmark)

    Hampwaye, Godfrey; Jeppesen, Søren; Kragelund, Peter

    This paper provides background data and general information for the Zambia studies focusing on local food processing sub­‐sector; and the local suppliers to the mines as part of the SAFIC project (Successful African Firms and Institutional Change).......This paper provides background data and general information for the Zambia studies focusing on local food processing sub­‐sector; and the local suppliers to the mines as part of the SAFIC project (Successful African Firms and Institutional Change)....

  15. Isodose mapping of terrestrial gamma radiation dose rate of Selangor state, Kuala Lumpur and Putrajaya, Malaysia

    International Nuclear Information System (INIS)

    Sanusi, M.S.M.; Ramli, A.T.; Gabdo, H.T.; Garba, N.N.; Heryanshah, A.; Wagiran, H.; Said, M.N.

    2014-01-01

    A terrestrial gamma radiation survey for the state of Selangor, Kuala Lumpur and Putrajaya was conducted to obtain baseline data for environmental radiological health practices. Based on soil type, geological background and information from airborne survey maps, 95 survey points statistically representing the study area were determined. The measured doses varied according to geological background and soil types. They ranged from 17 nGy h −1 to 500 nGy h −1 . The mean terrestrial gamma dose rate in air above the ground was 182 ± 81 nGy h −1 . This is two times higher than the average dose rate of terrestrial gamma radiation in Malaysia which is 92 nGy h −1 (UNSCEAR 2000). An isodose map was produced to represent exposure rate from natural sources of terrestrial gamma radiation. - Highlights: • A methodology is presented to reduce terrestrial gamma dose rate field survey. • Geological background of acid intrusive of granitic type has the highest dose rates. • The mean dose rate is 2 times higher than the world average. • Isodose map of terrestrial gamma radiation for Selangor, Kuala Lumpur and Putrajaya was produced

  16. Groundwater and Terrestrial Water Storage

    Science.gov (United States)

    Rodell, Matthew; Chambers, Don P.; Famiglietti, James S.

    2014-01-01

    Terrestrial water storage (TWS) comprises groundwater, soil moisture, surface water, snow,and ice. Groundwater typically varies more slowly than the other TWS components because itis not in direct contact with the atmosphere, but often it has a larger range of variability onmultiannual timescales (Rodell and Famiglietti, 2001; Alley et al., 2002). In situ groundwaterdata are only archived and made available by a few countries. However, monthly TWSvariations observed by the Gravity Recovery and Climate Experiment (GRACE; Tapley et al.,2004) satellite mission, which launched in 2002, are a reasonable proxy for unconfinedgroundwater at climatic scales.

  17. Workshop on Oxygen in the Terrestrial Planets

    Science.gov (United States)

    2004-01-01

    Lunar Metal Grains: Solar, Lunar or Terrestrial Origin? 22) Isotopic Zoning in the Inner Solar System; 23) Redox Conditions on Small Bodies; 24) Determining the Oxygen Fugacity of Lunar Pyroclastic Glasses Using Vanadium Valence - An Update; 25) Mantle Redox Evolution and the Rise of Atmospheric O2; 26) Variation of Kd for Fe-Mg Exchange Between Olivine and Melt for Compositions Ranging from Alkaline Basalt to Rhyolite; 27) Determining the Partial Pressure of Oxygen (PO,) in Solutions on Mars; 28) The Influence of Oxygen Environment on Kinetic Properties of Silicate Rocks and Minerals; 29) Redox Evolution of Magmatic Systems; 30) The Constancy of Upper Mantlefo, Through Time Inferred from V/Sc Ratios in Basalts: Implications for the Rise in Atmospheric 0 2; 31) Nitrogen Solubility in Basaltic Melt. Effects of Oxygen Fugacity, Melt Composition and Gas Speciation; 32) Oxygen Isotope Anomalies in the Atmospheres of Earth and Mars; 33) The Effect of Oxygen Fugacity on Interdiffusion of Iron and Magnesium in Magnesiowiistite 34) The Calibration of the Pyroxene Eu-Oxybarometer for the Martian Meteorites; 35) The Europium Oxybarometer: Power and Pitfalls; 36) Oxygen Fugacity of the Martian Mantle from PigeoniteMelt Partitioning of Samarium, Europium and Gadolinium; 37) Oxidation-Reduction Processes on the Moon: Experimental Verification of Graphite Oxidation in the Apollo 17 Orange Glasses; 38) Oxygen and Core Formation in the Earth; 39) Geologic Record of the Atmospheric Sulfur Chemistry Before the Oxygenation of the Early Earth s Atmosphere; 40) Comparative Planetary Mineralogy: V/(CrCAl) Systematics in Chromite as an Indicator of Relative Oxygen Fugacity; 41) How Well do Sulfur Isotopes Constrain Oxygen Abundance in the Ancient Atmospheres? 42) Experimental Constraints on the Oxygen Isotope (O-18/ O-16) Fractionation in the Ice vapor and Adsorbant vapor Systems of CO2 at Conditions Relevant to the Surface of Mars; 43) Micro-XANES Measurements on Experimental Spinels andhe

  18. The natural radiation background

    International Nuclear Information System (INIS)

    Duggleby, J.C.

    1982-01-01

    The components of the natural background radiation and their variations are described. Cosmic radiation is a major contributor to the external dose to the human body whilst naturally-occurring radionuclides of primordial and cosmogenic origin contribute to both the external and internal doses, with the primordial radionuclides being the major contributor in both cases. Man has continually modified the radiation dose to which he has been subjected. The two traditional methods of measuring background radiation, ionisation chamber measurements and scintillation counting, are looked at and the prospect of using thermoluminescent dosimetry is considered

  19. Effects of background radiation

    International Nuclear Information System (INIS)

    Knox, E.G.; Stewart, A.M.; Gilman, E.A.; Kneale, G.W.

    1987-01-01

    The primary objective of this investigation is to measure the relationship between exposure to different levels of background gamma radiation in different parts of the country, and different Relative Risks for leukaemias and cancers in children. The investigation is linked to an earlier analysis of the effects of prenatal medical x-rays upon leukaemia and cancer risk; the prior hypothesis on which the background-study was based, is derived from the earlier results. In a third analysis, the authors attempted to measure varying potency of medical x-rays delivered at different stages of gestation and the results supply a link between the other two estimates. (author)

  20. The cosmic microwave background

    International Nuclear Information System (INIS)

    Silk, J.

    1991-01-01

    Recent limits on spectral distortions and angular anisotropies in the cosmic microwave background are reviewed. The various backgrounds are described, and the theoretical implications are assessed. Constraints on inflationary cosmology dominated by cold dark matter (CDM) and on open cosmological models dominated by baryonic dark matter (BDM), with, respectively, primordial random phase scale-invariant curvature fluctuations or non-gaussian isocurvature fluctuations are described. More exotic theories are addressed, and I conclude with the 'bottom line': what theories expect experimentalists to be measuring within the next two to three years without having to abandon their most cherished theorists. (orig.)

  1. The Cosmic Background Explorer

    Science.gov (United States)

    Gulkis, Samuel; Lubin, Philip M.; Meyer, Stephan S.; Silverberg, Robert F.

    1990-01-01

    The Cosmic Background Explorer (CBE), NASA's cosmological satellite which will observe a radiative relic of the big bang, is discussed. The major questions connected to the big bang theory which may be clarified using the CBE are reviewed. The satellite instruments and experiments are described, including the Differential Microwave Radiometer, which measures the difference between microwave radiation emitted from two points on the sky, the Far-Infrared Absolute Spectrophotometer, which compares the spectrum of radiation from the sky at wavelengths from 100 microns to one cm with that from an internal blackbody, and the Diffuse Infrared Background Experiment, which searches for the radiation from the earliest generation of stars.

  2. Preparation and characterization of Tribulus terrestris-loaded nanoparticles

    Directory of Open Access Journals (Sweden)

    M. Khanavi*

    2017-11-01

    Full Text Available Background and objectives: Tribulus terrestris is a flowering herb (Zygophyllaceae with several properties in folk medicine such as diuretic, tonic, aphrodisiac, analgesic, astringent, and stomachic-lithotripter activities. Although, some extracts and phytochemicals represent excellent bio-activity in vitro, less or no in vivo activity is observed due to their improper molecular size. The intend of this research was investigation of the feasibility of encapsulating T. terrestris into [poly (lactic-co-glycolic acid] PLGA nanoparticles. Methods: Aerial parts of the plant were extracted with aqueous ethanol 85% by percolation apparatus. The nanoparticles of T. terrestris-loaded were prepared using a modified simultaneous double-emulsion solvent evaporation/diffusion method. Elucidations were made on the basis of scanning electron microscopy (SEM and differential scanning calorimetry (DSC. The content of nanoparticles was analyzed by HPLC with indirect method. Results: The results stated that increasing the portion of plant extract could cause bigger size with no considerable increase in polydispersity index (PDI. The encapsulation efficiency of T. terrestris-loaded nanoparticles was 40.3 to 78.5 and the drug loadings were 0.806 to 6.104, with different ratios of extract. The overall pattern of the release in SDS 1% in dialysis bag in all formulations showed similar and biphasic release kinetic, an initial burst release in the first day followed by constant release over 10 days. Conclusion: An effective approach for the preparation of T. terrestris-loaded PLGA nanoparticles was performed. The controlled release profile showed that these biodegradable PLGA nanoparticles had great potential and should be given particular consideration in further biological researches.

  3. 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

  4. 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.

  5. 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.

  6. Thermal background noise limitations

    Science.gov (United States)

    Gulkis, S.

    1982-01-01

    Modern detection systems are increasingly limited in sensitivity by the background thermal photons which enter the receiving system. Expressions for the fluctuations of detected thermal radiation are derived. Incoherent and heterodyne detection processes are considered. References to the subject of photon detection statistics are given.

  7. Berkeley Low Background Facility

    International Nuclear Information System (INIS)

    Thomas, K. J.; Norman, E. B.; Smith, A. R.; Poon, A. W. P.; Chan, Y. D.; Lesko, K. T.

    2015-01-01

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects

  8. Riparian vegetation in the alpine connectome: Terrestrial-aquatic and terrestrial-terrestrial interactions.

    Science.gov (United States)

    Zaharescu, Dragos G; Palanca-Soler, Antonio; Hooda, Peter S; Tanase, Catalin; Burghelea, Carmen I; Lester, Richard N

    2017-12-01

    Alpine regions are under increased attention worldwide for their critical role in early biogeochemical cycles, their high sensitivity to environmental change, and as repositories of natural resources of high quality. Their riparian ecosystems, at the interface between aquatic and terrestrial environments, play important geochemical functions in the watershed and are biodiversity hotspots, despite a harsh climate and topographic setting. With climate change rapidly affecting the alpine biome, we still lack a comprehensive understanding of the extent of interactions between riparian surface, lake and catchment environments. A total of 189 glacial - origin lakes were surveyed in the Central Pyrenees to test how key elements of the lake and terrestrial environments interact at different scales to shape riparian plant composition. Secondly, we evaluated how underlying ecotope features drive the formation of natural communities potentially sensitive to environmental change and assessed their habitat distribution. At the macroscale, vegetation composition responded to pan-climatic gradients altitude and latitude, which captured in a narrow geographic area the transition between large European climatic zones. Hydrodynamics was the main catchment-scale factor connecting riparian vegetation with major water fluxes, followed by topography and geomorphology. Lake sediment Mg and Pb, and water Mn and Fe contents reflected local influences from mafic bedrock and soil water saturation. Community analysis identified four keystone ecosystems: (i) damp ecotone, (ii) snow bed-silicate bedrock, (iii) wet heath, and (iv) calcareous substrate. These communities and their connections with ecotope elements could be at risk from a number of environmental change factors including warmer seasons, snow line and lowland species advancement, increased nutrient/metal input and water level fluctuations. The results imply important natural terrestrial-aquatic linkages in the riparian environment

  9. The Cosmic Microwave Background

    Directory of Open Access Journals (Sweden)

    Jones Aled

    1998-01-01

    Full Text Available We present a brief review of current theory and observations of the cosmic microwave background (CMB. New predictions for cosmological defect theories and an overview of the inflationary theory are discussed. Recent results from various observations of the anisotropies of the microwave background are described and a summary of the proposed experiments is presented. A new analysis technique based on Bayesian statistics that can be used to reconstruct the underlying sky fluctuations is summarised. Current CMB data is used to set some preliminary constraints on the values of fundamental cosmological parameters $Omega$ and $H_circ$ using the maximum likelihood technique. In addition, secondary anisotropies due to the Sunyaev-Zel'dovich effect are described.

  10. Terrestrial gamma-ray flashes

    Science.gov (United States)

    Marisaldi, Martino; Fuschino, Fabio; Labanti, Claudio; Tavani, Marco; Argan, Andrea; Del Monte, Ettore; Longo, Francesco; Barbiellini, Guido; Giuliani, Andrea; Trois, Alessio; Bulgarelli, Andrea; Gianotti, Fulvio; Trifoglio, Massimo

    2013-08-01

    Lightning and thunderstorm systems in general have been recently recognized as powerful particle accelerators, capable of producing electrons, positrons, gamma-rays and neutrons with energies as high as several tens of MeV. In fact, these natural systems turn out to be the highest energy and most efficient natural particle accelerators on Earth. Terrestrial Gamma-ray Flashes (TGFs) are millisecond long, very intense bursts of gamma-rays and are one of the most intriguing manifestation of these natural accelerators. Only three currently operative missions are capable of detecting TGFs from space: the RHESSI, Fermi and AGILE satellites. In this paper we review the characteristics of TGFs, including energy spectrum, timing structure, beam geometry and correlation with lightning, and the basic principles of the associated production models. Then we focus on the recent AGILE discoveries concerning the high energy extension of the TGF spectrum up to 100 MeV, which is difficult to reconcile with current theoretical models.

  11. Terrestrial gamma-ray flashes

    International Nuclear Information System (INIS)

    Marisaldi, Martino; Fuschino, Fabio; Labanti, Claudio; Tavani, Marco; Argan, Andrea; Del Monte, Ettore; Longo, Francesco; Barbiellini, Guido; Giuliani, Andrea; Trois, Alessio; Bulgarelli, Andrea; Gianotti, Fulvio; Trifoglio, Massimo

    2013-01-01

    Lightning and thunderstorm systems in general have been recently recognized as powerful particle accelerators, capable of producing electrons, positrons, gamma-rays and neutrons with energies as high as several tens of MeV. In fact, these natural systems turn out to be the highest energy and most efficient natural particle accelerators on Earth. Terrestrial Gamma-ray Flashes (TGFs) are millisecond long, very intense bursts of gamma-rays and are one of the most intriguing manifestation of these natural accelerators. Only three currently operative missions are capable of detecting TGFs from space: the RHESSI, Fermi and AGILE satellites. In this paper we review the characteristics of TGFs, including energy spectrum, timing structure, beam geometry and correlation with lightning, and the basic principles of the associated production models. Then we focus on the recent AGILE discoveries concerning the high energy extension of the TGF spectrum up to 100 MeV, which is difficult to reconcile with current theoretical models

  12. Radionuclide transfer in terrestrial animals

    International Nuclear Information System (INIS)

    DiGregorio, D.; Kitchings, T.; Van Voris, P.

    1978-01-01

    The analysis of dispersion of radionuclides in terrestrial food chains, generally, is a series of equations identifying the fractional input and outflow rates from trophic level to trophic level. Data that are prerequisite inputs for these food chain transport models include: (1) identification of specific transport pathway, (2) assimilation at each pathway link, and (3) the turnover rate or retention function by successive receptor species in the appropriate food chain. In this report, assimilation coefficients, biological half-lives, and excretion rates for a wide variety of vertebrate and invertebrate species and radionuclides have been compiled from an extensive search of the available literature. Using the information accumulated from the literature, correlations of nuclide metabolism and body weight are also discussed. (author)

  13. Methyl mercury in terrestrial compartments

    International Nuclear Information System (INIS)

    Stoeppler, M.; Burow, M.; Padberg, S.; May, K.

    1993-09-01

    On the basis of the analytical methodology available at present the state of the art for the determination of total mercury and of various organometallic compounds of mercury in air, precipitation, limnic systems, soils, plants and biota is reviewed. This is followed by the presentation and discussion of examples for the data obtained hitherto for trace and ultratrace levels of total mercury and mainly methyl mercury in terrestrial and limnic environments as well as in biota. The data discussed stem predominantly from the past decade in which, due to significant methodological progress, many new aspects were elucidated. They include the most important results in this area achieved by the Research Centre (KFA) Juelich within the project 'Origin and Fate of Methyl Mercury' (contracts EV4V-0138-D and STEP-CT90-0057) supported by the Commission of the European Communities, Brussels. (orig.) [de

  14. Traumatic insemination in terrestrial arthropods.

    Science.gov (United States)

    Tatarnic, Nikolai J; Cassis, Gerasimos; Siva-Jothy, Michael T

    2014-01-01

    Traumatic insemination is a bizarre form of mating practiced by some invertebrates in which males use hypodermic genitalia to penetrate their partner's body wall during copulation, frequently bypassing the female genital tract and ejaculating into their blood system. The requirements for traumatic insemination to evolve are stringent, yet surprisingly it has arisen multiple times within invertebrates. In terrestrial arthropods traumatic insemination is most prevalent in the true bug infraorder Cimicomorpha, where it has evolved independently at least three times. Traumatic insemination is thought to occur in the Strepsiptera and has recently been recorded in fruit fly and spider lineages. We review the putative selective pressures that may have led to the evolution of traumatic insemination across these lineages, as well as the pressures that continue to drive divergence in male and female reproductive morphology and behavior. Traumatic insemination mechanisms and attributes are compared across independent lineages.

  15. Phytopharmacological overview of Tribulus terrestris

    Science.gov (United States)

    Chhatre, Saurabh; Nesari, Tanuja; Somani, Gauresh; Kanchan, Divya; Sathaye, Sadhana

    2014-01-01

    Tribulus terrestris (family Zygophyllaceae), commonly known as Gokshur or Gokharu or puncture vine, has been used for a long time in both the Indian and Chinese systems of medicine for treatment of various kinds of diseases. Its various parts contain a variety of chemical constituents which are medicinally important, such as flavonoids, flavonol glycosides, steroidal saponins, and alkaloids. It has diuretic, aphrodisiac, antiurolithic, immunomodulatory, antidiabetic, absorption enhancing, hypolipidemic, cardiotonic, central nervous system, hepatoprotective, anti-inflammatory, analgesic, antispasmodic, anticancer, antibacterial, anthelmintic, larvicidal, and anticariogenic activities. For the last few decades or so, extensive research work has been done to prove its biological activities and the pharmacology of its extracts. The aim of this review is to create a database for further investigations of the discovered phytochemical and pharmacological properties of this plant to promote research. This will help in confirmation of its traditional use along with its value-added utility, eventually leading to higher revenues from the plant. PMID:24600195

  16. Terrestrial atmosphere, water and astrobiology

    Directory of Open Access Journals (Sweden)

    Coradini M.

    2010-12-01

    Full Text Available Primitive life, defined as a chemical system capable to transfer its molecular information via self-replication and also capable to evolve, originated about 4 billion years ago from the processing of organic molecules by liquid water. Terrestrial atmosphere played a key role in the process by allowing the permanent presence of liquid water and by participating in the production of carbon-based molecules. Water molecules exhibit specific properties mainly due to a dense network of hydrogen bonds. The carbon-based molecules were either home made in the atmosphere and/or in submarine hydrothermal systems or delivered by meteorites and micrometeorites. The search for possible places beyond the earth where the trilogy atmosphere/water/life could exist is the main objective of astrobiology. Within the Solar System, exploration missions are dedicated to Mars, Europa, Titan and the icy bodies. The discovery of several hundreds of extrasolar planets opens the quest to the whole Milky Way.

  17. Terrestrial pathways of radionuclide particulates

    International Nuclear Information System (INIS)

    Boone, F.W.; Ng, Y.C.

    1981-01-01

    Formulations are developed for computing potential human intake of 13 radionuclides via the terrestrial food chains. The formulations are an extension of the NRC methodology. Specific regional crop and livestock transfer and fractional distribution data from the southern part of the U.S.A. are provided and used in the computation of comparative values with those computed by means of USNRC Regulatory Guide 1.109 formulations. In the development of the model, emphasis was also placed on identifying the various time-delay compartments of the food chains and accounting for all of the activity initially deposited. For all radionuclides considered, except 137 Cs, the new formulations predict lower potential intakes from the total of all food chains combined than do the comparable Regulatory Guide formulations by as much as a factor of 40. For 137 Cs the new formulations predict 10% higher potential intakes. (author)

  18. A Spherical Aerial Terrestrial Robot

    Science.gov (United States)

    Dudley, Christopher J.

    This thesis focuses on the design of a novel, ultra-lightweight spherical aerial terrestrial robot (ATR). The ATR has the ability to fly through the air or roll on the ground, for applications that include search and rescue, mapping, surveillance, environmental sensing, and entertainment. The design centers around a micro-quadcopter encased in a lightweight spherical exoskeleton that can rotate about the quadcopter. The spherical exoskeleton offers agile ground locomotion while maintaining characteristics of a basic aerial robot in flying mode. A model of the system dynamics for both modes of locomotion is presented and utilized in simulations to generate potential trajectories for aerial and terrestrial locomotion. Details of the quadcopter and exoskeleton design and fabrication are discussed, including the robot's turning characteristic over ground and the spring-steel exoskeleton with carbon fiber axle. The capabilities of the ATR are experimentally tested and are in good agreement with model-simulated performance. An energy analysis is presented to validate the overall efficiency of the robot in both modes of locomotion. Experimentally-supported estimates show that the ATR can roll along the ground for over 12 minutes and cover the distance of 1.7 km, or it can fly for 4.82 minutes and travel 469 m, on a single 350 mAh battery. Compared to a traditional flying-only robot, the ATR traveling over the same distance in rolling mode is 2.63-times more efficient, and in flying mode the system is only 39 percent less efficient. Experimental results also demonstrate the ATR's transition from rolling to flying mode.

  19. 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

  20. Biogeochemical signals from deep microbial life in terrestrial crust.

    Directory of Open Access Journals (Sweden)

    Yohey Suzuki

    Full Text Available In contrast to the deep subseafloor biosphere, a volumetrically vast and stable habitat for microbial life in the terrestrial crust remains poorly explored. For the long-term sustainability of a crustal biome, high-energy fluxes derived from hydrothermal circulation and water radiolysis in uranium-enriched rocks are seemingly essential. However, the crustal habitability depending on a low supply of energy is unknown. We present multi-isotopic evidence of microbially mediated sulfate reduction in a granitic aquifer, a representative of the terrestrial crust habitat. Deep meteoric groundwater was collected from underground boreholes drilled into Cretaceous Toki granite (central Japan. A large sulfur isotopic fractionation of 20-60‰ diagnostic to microbial sulfate reduction is associated with the investigated groundwater containing sulfate below 0.2 mM. In contrast, a small carbon isotopic fractionation (<30‰ is not indicative of methanogenesis. Except for 2011, the concentrations of H2 ranged mostly from 1 to 5 nM, which is also consistent with an aquifer where a terminal electron accepting process is dominantly controlled by ongoing sulfate reduction. High isotopic ratios of mantle-derived 3He relative to radiogenic 4He in groundwater and the flux of H2 along adjacent faults suggest that, in addition to low concentrations of organic matter (<70 µM, H2 from deeper sources might partly fuel metabolic activities. Our results demonstrate that the deep biosphere in the terrestrial crust is metabolically active and playing a crucial role in the formation of reducing groundwater even under low-energy fluxes.

  1. Family Background and Entrepreneurship

    DEFF Research Database (Denmark)

    Lindquist, Matthew J.; Sol, Joeri; Van Praag, Mirjam

    Vast amounts of money are currently being spent on policies aimed at promoting entrepreneurship. The success of such policies, however, rests in part on the assumption that individuals are not ‘born entrepreneurs’. In this paper, we assess the importance of family background and neighborhood...... effects as determinants of entrepreneurship. We start by estimating sibling correlations in entrepreneurship. We find that between 20 and 50 percent of the variance in different entrepreneurial outcomes is explained by factors that siblings share. The average is 28 percent. Allowing for differential...... entrepreneurship does play a large role, as do shared genes....

  2. Malaysia; Background Paper

    OpenAIRE

    International Monetary Fund

    1996-01-01

    This Background Paper on Malaysia examines developments and trends in the labor market since the mid-1980s. The paper describes the changes in the employment structure and the labor force. It reviews wages and productivity trends and their effects on unit labor cost. The paper highlights that Malaysia’s rapid growth, sustained since 1987, has had a major impact on the labor market. The paper outlines the major policy measures to address the labor constraints. It also analyzes Malaysia’s recen...

  3. Processing horizontal networks measured by integrated terrestrial and GPS technologies

    Directory of Open Access Journals (Sweden)

    Vincent Jakub

    2003-09-01

    Full Text Available Local horizontal networks in which GPS and terrestrial measurements (TER are done are often established at present. Iin other networks, the previous terrestrial measurements can be completed with quantities from contemporary GPS observations (tunnel nets, mining nets with surface and underground parts and other long-shaped nets.The processing of such heterobeneous (GPS, TER networks whose terrestrial measurements are performed as point coordinate measurements (∆X, ∆Y using (geodetic total stationIn is presented in this paper. In such network structures it is then available:- the values ∆X, ∆Y from TER observations which are transformed in the plane of S-JTSK for adjustement,- the values ∆X, ∆Y in the plane S-JTSK that can be obtained by 3D transformation of WGS84 netpoint coordinates from GPS observations to corresponding coordinates S-JTSK.For common adjusting all the ∆X, ∆Y, some elements of the network geometry (e.g. distances should be measured by both methods (GPS, TER. This approach makes possible an effective homogenisation of both network parts what is equivalent to saying that an expressive influence reduction on local frame realizations of S-JTSK in the whole network can be made.Results of network processing obtained in proposed manner are acceptable in general and they are equivalent (accuracy, reliability to results of another processing methods.

  4. Synergistic Antimicrobial Effect of Tribulus terrestris and Bitter Almond Extracts

    Directory of Open Access Journals (Sweden)

    Hamid Abtahi

    2014-12-01

    Full Text Available Background: The antimicrobial effects of the extracts of different kinds of plants have been demonstrated in several studies. However, no study has been conducted so far on the synergistic effects of two herbal extracts on their germicidal effects. In this study, in addition to antibacterial effects of the aqueous, methanol or ethanol extracts of Tribulus terrestris and bitter almond on some bacteria, the synergistic effects of the extracts of these two plants were also evaluated. Materials and Methods: In this experimental study, water, methanol and ethanol extracts of seeds were screened against some bacterial strains. Seeds were extracted by percolation method. Aliquots of the extracts at variable concentrations were then incubated with different bacterial strains, and the antimicrobial activities of the extracts from seeds were determined by MIC. Three antibiotics were used as reference compounds for antibacterial activities. Seeds extract inhibited significantly the growth of the tested bacterial strains. Results: The greatest synergistic effect of T. terrestris and bitter almond extracts is detected in methanol and aqueous extracts. Among the bacterial strains tested, Staphylococcus aureus was most susceptibility. Conclusion: The results showed the highest antibacterial effect in the combination of methanol extract of T. terrestris and the aqueous extract of the bitter almond.

  5. Background of SAM atom-fraction profiles

    International Nuclear Information System (INIS)

    Ernst, Frank

    2017-01-01

    Atom-fraction profiles acquired by SAM (scanning Auger microprobe) have important applications, e.g. in the context of alloy surface engineering by infusion of carbon or nitrogen through the alloy surface. However, such profiles often exhibit an artifact in form of a background with a level that anti-correlates with the local atom fraction. This article presents a theory explaining this phenomenon as a consequence of the way in which random noise in the spectrum propagates into the discretized differentiated spectrum that is used for quantification. The resulting model of “energy channel statistics” leads to a useful semi-quantitative background reduction procedure, which is validated by applying it to simulated data. Subsequently, the procedure is applied to an example of experimental SAM data. The analysis leads to conclusions regarding optimum experimental acquisition conditions. The proposed method of background reduction is based on general principles and should be useful for a broad variety of applications. - Highlights: • Atom-fraction–depth profiles of carbon measured by scanning Auger microprobe • Strong background, varies with local carbon concentration. • Needs correction e.g. for quantitative comparison with simulations • Quantitative theory explains background. • Provides background removal strategy and practical advice for acquisition

  6. Background of SAM atom-fraction profiles

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, Frank

    2017-03-15

    Atom-fraction profiles acquired by SAM (scanning Auger microprobe) have important applications, e.g. in the context of alloy surface engineering by infusion of carbon or nitrogen through the alloy surface. However, such profiles often exhibit an artifact in form of a background with a level that anti-correlates with the local atom fraction. This article presents a theory explaining this phenomenon as a consequence of the way in which random noise in the spectrum propagates into the discretized differentiated spectrum that is used for quantification. The resulting model of “energy channel statistics” leads to a useful semi-quantitative background reduction procedure, which is validated by applying it to simulated data. Subsequently, the procedure is applied to an example of experimental SAM data. The analysis leads to conclusions regarding optimum experimental acquisition conditions. The proposed method of background reduction is based on general principles and should be useful for a broad variety of applications. - Highlights: • Atom-fraction–depth profiles of carbon measured by scanning Auger microprobe • Strong background, varies with local carbon concentration. • Needs correction e.g. for quantitative comparison with simulations • Quantitative theory explains background. • Provides background removal strategy and practical advice for acquisition.

  7. Backgrounded but not peripheral

    DEFF Research Database (Denmark)

    Hovmark, Henrik

    2013-01-01

    .e. the schema enters into apparently contradictory constructions of the informants’ local home-base and, possibly, of their identity (cf. Hovmark, 2010). Second, I discuss the status and role of the specific linguistic category in question, i.e. the directional adverbs. On the one hand we claim that the DDAs......In this paper I pay a closer look at the use of the CENTRE-PERIPHERY schema in context. I address two specific issues: first, I show how the CENTRE-PERIPHERY schema, encoded in the DDAs, enters into discourses that conceptualize and characterize a local community as both CENTRE and PERIPHERY, i......; furthermore, the DDAs are backgrounded in discourse. Is it reasonable to claim, rather boldly, that “the informants express their identity in the use of the directional adverb ud ‘out’ etc.”? In the course of this article, however, I suggest that the DDAs in question do contribute to the socio...

  8. OCRWM Backgrounder, January 1987

    International Nuclear Information System (INIS)

    1987-01-01

    The Nuclear Waste Policy Act of 1982 (NWPA) assigns to the US Department of Energy (DOE) responsibility for developing a system to safely and economically transport spent nuclear fuel and high-level radioactive waste from various storage sites to geologic repositories or other facilities that constitute elements of the waste management program. This transportation system will evolve from technologies and capabilities already developed. Shipments of spent fuel to a monitored retrievable storage (MRS) facility could begin as early as 1996 if Congress authorizes its construction. Shipments of spent fuel to a geologic repository are scheduled to begin in 1998. The backgrounder provides an overview of DOE's cask development program. Transportation casks are a major element in the DOE nuclear waste transportation system because they are the primary protection against any potential radiation exposure to the public and transportation workers in the event an accident occurs

  9. Monitored background radiometer

    International Nuclear Information System (INIS)

    Ruel, C.

    1988-01-01

    A monitored background radiometer is described comprising: a thermally conductive housing; low conductivity support means mounted on the housing; a sensing plate mounted on the low conductivity support means and spaced from the housing so as to be thermally insulated from the housing and having an outwardly facing first surface; the sensing plate being disposed relative to the housing to receive direct electromagnetic radiation from sources exterior to the radiometer upon the first surface only; means for controllably heating the sensing plate; first temperature sensitive means to measure the temperature of the housing; and second temperature sensitive means to measure the temperature of the sensing plate, so that the heat flux at the sensing plate may be determined from the temperatures of the housing and sensing plate after calibration of the radiometer by measuring the temperatures of the housing and sensing plate while controllably heating the sensing plate

  10. Reduction redux.

    Science.gov (United States)

    Shapiro, Lawrence

    2018-04-01

    Putnam's criticisms of the identity theory attack a straw man. Fodor's criticisms of reduction attack a straw man. Properly interpreted, Nagel offered a conception of reduction that captures everything a physicalist could want. I update Nagel, introducing the idea of overlap, and show why multiple realization poses no challenge to reduction so construed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Does terrestrial epidemiology apply to marine systems?

    Science.gov (United States)

    McCallum, Hamish I.; Kuris, Armand M.; Harvell, C. Drew; Lafferty, Kevin D.; Smith, Garriet W.; Porter, James

    2004-01-01

    Most of epidemiological theory has been developed for terrestrial systems, but the significance of disease in the ocean is now being recognized. However, the extent to which terrestrial epidemiology can be directly transferred to marine systems is uncertain. Many broad types of disease-causing organism occur both on land and in the sea, and it is clear that some emergent disease problems in marine environments are caused by pathogens moving from terrestrial to marine systems. However, marine systems are qualitatively different from terrestrial environments, and these differences affect the application of modelling and management approaches that have been developed for terrestrial systems. Phyla and body plans are more diverse in marine environments and marine organisms have different life histories and probably different disease transmission modes than many of their terrestrial counterparts. Marine populations are typically more open than terrestrial ones, with the potential for long-distance dispersal of larvae. Potentially, this might enable unusually rapid propagation of epidemics in marine systems, and there are several examples of this. Taken together, these differences will require the development of new approaches to modelling and control of infectious disease in the ocean.

  12. Steroidal saponins from Tribulus terrestris.

    Science.gov (United States)

    Kang, Li-Ping; Wu, Ke-Lei; Yu, He-Shui; Pang, Xu; Liu, Jie; Han, Li-Feng; Zhang, Jie; Zhao, Yang; Xiong, Cheng-Qi; Song, Xin-Bo; Liu, Chao; Cong, Yu-Wen; Ma, Bai-Ping

    2014-11-01

    Sixteen steroidal saponins, including seven previously unreported compounds, were isolated from Tribulus terrestris. The structures of the saponins were established using 1D and 2D NMR spectroscopy, mass spectrometry, and chemical methods. They were identified as: 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-2α,3β,22α,26-tetrol-12-one (terrestrinin C), 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-22α,26-diol-3,12-dione (terrestrinin D), 26-O-β-d-glucopyranosyl-(25S)-furost-4-en-22α,26-diol-3,6,12-trione (terrestrinin E), 26-O-β-d-glucopyranosyl-(25R)-5α-furostan-3β,22α,26-triol-12-one (terrestrinin F), 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-12β,22α,26-triol-3-one (terrestrinin G), 26-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl-(25R)-furost-4-en-22α,26-diol-3,12-dione (terrestrinin H), and 24-O-β-d-glucopyranosyl-(25S)-5α-spirostan-3β,24β-diol-12-one-3-O-β-d-glucopyranosyl-(1→4)-β-d-galactopyranoside (terrestrinin I). The isolated compounds were evaluated for their platelet aggregation activities. Three of the known saponins exhibited strong effects on the induction of platelet aggregation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Sex ratio variation in the bumblebee Bombus terrestris

    DEFF Research Database (Denmark)

    Duchateau, Marie José; Velthuis, Hayo H. W.; Boomsma, Jacobus Jan

    2004-01-01

    Bombus terrestris, bumblebees, colony development, queen control, reproductive strategies, sex allocation......Bombus terrestris, bumblebees, colony development, queen control, reproductive strategies, sex allocation...

  14. Low background infrared (LBIR) facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Low background infrared (LBIR) facility was originally designed to calibrate user supplied blackbody sources and to characterize low-background IR detectors and...

  15. The Circumpolar Biodiversity Monitoring Program Terrestrial Plan

    DEFF Research Database (Denmark)

    Christensen, Tom; Payne, J.; Doyle, M.

    , understand and report on long-term change in Arctic terrestrial ecosystems and biodiversity, and to identify knowledge gaps and priorities. This poster will outline the key management questions the plan aims to address and the proposed nested, multi-scaled approach linking targeted, research based monitoring...... and coastal environments. The CBMP Terrestrial Plan is a framework to focus and coordinate monitoring of terrestrial biodiversity across the Arctic. The goal of the plan is to improve the collective ability of Arctic traditional knowledge (TK) holders, northern communities, and scientists to detect...

  16. Underwater photosynthesis in flooded terrestrial plants: a matter of leaf plasticity

    NARCIS (Netherlands)

    Mommer, L.; Visser, E.J.W.

    2005-01-01

    Background Flooding causes substantial stress for terrestrial plants, particularly if the floodwater completely submerges the shoot. The main problems during submergence are shortage of oxygen due to the slow diffusion rates of gases in water, and depletion of carbohydrates, which is the substrate

  17. Gamma-emissions of some meteorites and terrestrial rocks. Evaluation of lunar soil radioactivity

    International Nuclear Information System (INIS)

    Nordemann, D.

    1966-01-01

    The gamma-emissions of some terrestrial rocks and of the following meteorites: Bogou, Eagle-Station, Granes, and Dosso were studied by quantitative low background gamma spectrometry. These measurements and their interpretation lead to the evaluation of the possible gamma-emissions of several models of lunar soils. (author) [fr

  18. Hanford Site background: Part 1, Soil background for nonradioactive analytes

    International Nuclear Information System (INIS)

    1993-04-01

    Volume two contains the following appendices: Description of soil sampling sites; sampling narrative; raw data soil background; background data analysis; sitewide background soil sampling plan; and use of soil background data for the detection of contamination at waste management unit on the Hanford Site

  19. Can polar bears use terrestrial foods to offset lost ice-based hunting opportunities?

    Science.gov (United States)

    Rode, Karyn D.; Robbins, Charles T.; Nelson, Lynne; Amstrup, Steven C.

    2015-01-01

    Increased land use by polar bears (Ursus maritimus) due to climate-change-induced reduction of their sea-ice habitat illustrates the impact of climate change on species distributions and the difficulty of conserving a large, highly specialized carnivore in the face of this global threat. Some authors have suggested that terrestrial food consumption by polar bears will help them withstand sea-ice loss as they are forced to spend increasing amounts of time on land. Here, we evaluate the nutritional needs of polar bears as well as the physiological and environmental constraints that shape their use of terrestrial ecosystems. Only small numbers of polar bears have been documented consuming terrestrial foods even in modest quantities. Over much of the polar bear's range, limited terrestrial food availability supports only low densities of much smaller, resident brown bears (Ursus arctos), which use low-quality resources more efficiently and may compete with polar bears in these areas. Where consumption of terrestrial foods has been documented, polar bear body condition and survival rates have declined even as land use has increased. Thus far, observed consumption of terrestrial food by polar bears has been insufficient to offset lost ice-based hunting opportunities but can have ecological consequences for other species. Warming-induced loss of sea ice remains the primary threat faced by polar bears.

  20. 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

  1. Po-210 and other radionuclides in terrestrial and freshwater environments

    Energy Technology Data Exchange (ETDEWEB)

    Gjelsvik, Runhild; Brown, Justin [eds.; Norwegian Radiation Protection Authority (Norway); Holm, Elis [Univ. of Lund (Sweden); Roos, Per [Risoe DTU (Denmark); Saxen, Ritva; Outola, Iisa [STUK - Radiation and Nuclear Safety Authority (Finland)

    2009-01-15

    This report provides new information on Po-210 (and where appropriate its grandparent Pb-210) behaviour in environmental systems including humans. This has primarily been achieved through measurements of Po-210 in aquatic and terrestrial environments that has led to the derivation of information on the levels of this radioisotope in plants, animals and the biotic components of their habitat (i.e. water, soil) providing basic information on transfer where practicable. For freshwater environments, Po-210 concentration ratios derived for freshwater benthic fish and bivalve mollusc were substantially different to values collated from earlier review work. For terrestrial environments, activity concentrations of Po-210 in small mammals (although of a preliminary nature because no correction was made for ingrowth from Pb-210) were considerably higher than values derived from earlier data compilations. It was envisaged that data on levels of naturally occurring radionuclides would render underpinning data sets more comprehensive and would thus allow more robust background dose calculations to be performed subsequently. By way of example, unweighted background dose-rates arising from internal distributions of Po-210 were calculated for small mammals in the terrestrial study. The biokinetics of polonium in humans has been studied following chronic and acute oral intakes of selected Po radioisotopes. This work has provided information on gastrointestinal absorption factors and biological retention times thus improving the database upon which committed effective doses to humans are derived. The information generated in the report, in its entirety, should be of direct relevance for both human and non-human impact assessments. (au)

  2. Po-210 and other radionuclides in terrestrial and freshwater environments

    International Nuclear Information System (INIS)

    Gjelsvik, Runhild; Brown, Justin; Roos, Per; Saxen, Ritva; Outola, Iisa

    2009-01-01

    This report provides new information on Po-210 (and where appropriate its grandparent Pb-210) behaviour in environmental systems including humans. This has primarily been achieved through measurements of Po-210 in aquatic and terrestrial environments that has led to the derivation of information on the levels of this radioisotope in plants, animals and the biotic components of their habitat (i.e. water, soil) providing basic information on transfer where practicable. For freshwater environments, Po-210 concentration ratios derived for freshwater benthic fish and bivalve mollusc were substantially different to values collated from earlier review work. For terrestrial environments, activity concentrations of Po-210 in small mammals (although of a preliminary nature because no correction was made for ingrowth from Pb-210) were considerably higher than values derived from earlier data compilations. It was envisaged that data on levels of naturally occurring radionuclides would render underpinning data sets more comprehensive and would thus allow more robust background dose calculations to be performed subsequently. By way of example, unweighted background dose-rates arising from internal distributions of Po-210 were calculated for small mammals in the terrestrial study. The biokinetics of polonium in humans has been studied following chronic and acute oral intakes of selected Po radioisotopes. This work has provided information on gastrointestinal absorption factors and biological retention times thus improving the database upon which committed effective doses to humans are derived. The information generated in the report, in its entirety, should be of direct relevance for both human and non-human impact assessments. (au)

  3. Methane emissions form terrestrial plants

    Energy Technology Data Exchange (ETDEWEB)

    Bergamaschi, P.; Dentener, F.; Grassi, G.; Leip, A.; Somogyi, Z.; Federici, S.; Seufert, G.; Raes, F. [European Commission, DG Joint Research Centre, Institute for Environment and Sustainability, Ispra (Italy)

    2006-07-01

    In a recent issue of Nature Keppler et al. (2006) report the discovery that terrestrial plants emit CH4 under aerobic conditions. Until now it was thought that bacterial decomposition of plant material under anaerobic conditions, such as in wetlands and water flooded rice paddies, is the main process leading to emissions from terrestrial ecosystems. In a first attempt to upscale these measurements, the authors estimate that global total emissions may be 149 Tg CH4/yr (62-236 Tg CH4/yr), with the main contribution estimated from tropical forests and grasslands (107 Tg CH4/yr with a range of 46-169 Tg CH4/yr). If confirmed, this new source of emission would constitute a significant fraction of the total global methane sources (estimated 500-600 Tg CH4/yr for present day total natural and anthropogenic sources) and have important implications for the global CH4 budget. To accommodate it within the present budget some sources would need to be re-assessed downwards and/or some sinks re-assessed upwards. Furthermore, also considering that methane is a {approx}23 times more powerful greenhouse gas than CO2, the possible feedbacks of these hitherto unknown CH4 emissions on global warming and their impacts on greenhouse gases (GHG) mitigation strategies need to be carefully evaluated. The merit of the paper is without doubt related to the remarkable discovery of a new process of methane emissions active under aerobic conditions. However, we think that the applied approach of scaling up emissions from the leaf level to global totals by using only few measured data (mainly from herbaceous species) and the Net Primary Productivity of the main biomes is scientifically questionable and tends to overestimate considerably the global estimates, especially for forest biomes. Furthermore, some significant constraints on the upper limit of the global natural CH4 emissions arise from the pre-industrial CH4 budget. Pre-industrial atmospheric CH4 mixing ratios have been measured

  4. Note on bouncing backgrounds

    Science.gov (United States)

    de Haro, Jaume; Pan, Supriya

    2018-05-01

    The theory of inflation is one of the fundamental and revolutionary developments of modern cosmology that became able to explain many issues of the early Universe in the context of the standard cosmological model (SCM). However, the initial singularity of the Universe, where physics is indefinite, is still obscure in the combined SCM +inflation scenario. An alternative to SCM +inflation without the initial singularity is thus always welcome, and bouncing cosmology is an attempt at that. The current work is thus motivated to investigate the bouncing solutions in modified gravity theories when the background universe is described by the spatially flat Friedmann-Lemaître-Robertson-Walker (FLRW) geometry. We show that the simplest way to obtain the bouncing cosmologies in such spacetime is to consider some kind of Lagrangian whose gravitational sector depends only on the square of the Hubble parameter of the FLRW universe. For these modified Lagrangians, the corresponding Friedmann equation, a constraint in the dynamics of the Universe, depicts a curve in the phase space (H ,ρ ), where H is the Hubble parameter and ρ is the energy density of the Universe. As a consequence, a bouncing cosmology is obtained when this curve is closed and crosses the axis H =0 at least twice, and whose simplest particular example is the ellipse depicting the well-known holonomy corrected Friedmann equation in loop quantum cosmology (LQC). Sometimes, a crucial point in such theories is the appearance of the Ostrogradski instability at the perturbative level; however, fortunately enough, in the present work, as long as the linear level of perturbations is concerned, this instability does not appear, although it may appear at the higher order of perturbations.

  5. 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.

  6. 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.

  7. Carbon dioxide efficiency of terrestrial enhanced weathering

    OpenAIRE

    Moosdorf, Nils; Renforth, Philip; Hartmann, Jens

    2014-01-01

    Terrestrial enhanced weathering, the spreading of ultramafic silicate rock flour to enhance natural weathering rates, has been suggested as part of a strategy to reduce global atmospheric CO2 levels. We budget potential CO2 sequestration against associated CO2 emissions to assess the net CO2 removal of terrestrial enhanced weathering. We combine global spatial data sets of potential source rocks, transport networks, and application areas with associated CO2 emissions in optimistic and pessimi...

  8. Parallel Computing for Terrestrial Ecosystem Carbon Modeling

    International Nuclear Information System (INIS)

    Wang, Dali; Post, Wilfred M.; Ricciuto, Daniel M.; Berry, Michael

    2011-01-01

    Terrestrial ecosystems are a primary component of research on global environmental change. Observational and modeling research on terrestrial ecosystems at the global scale, however, has lagged behind their counterparts for oceanic and atmospheric systems, largely because the unique challenges associated with the tremendous diversity and complexity of terrestrial ecosystems. There are 8 major types of terrestrial ecosystem: tropical rain forest, savannas, deserts, temperate grassland, deciduous forest, coniferous forest, tundra, and chaparral. The carbon cycle is an important mechanism in the coupling of terrestrial ecosystems with climate through biological fluxes of CO 2 . The influence of terrestrial ecosystems on atmospheric CO 2 can be modeled via several means at different timescales. Important processes include plant dynamics, change in land use, as well as ecosystem biogeography. Over the past several decades, many terrestrial ecosystem models (see the 'Model developments' section) have been developed to understand the interactions between terrestrial carbon storage and CO 2 concentration in the atmosphere, as well as the consequences of these interactions. Early TECMs generally adapted simple box-flow exchange models, in which photosynthetic CO 2 uptake and respiratory CO 2 release are simulated in an empirical manner with a small number of vegetation and soil carbon pools. Demands on kinds and amount of information required from global TECMs have grown. Recently, along with the rapid development of parallel computing, spatially explicit TECMs with detailed process based representations of carbon dynamics become attractive, because those models can readily incorporate a variety of additional ecosystem processes (such as dispersal, establishment, growth, mortality etc.) and environmental factors (such as landscape position, pest populations, disturbances, resource manipulations, etc.), and provide information to frame policy options for climate change

  9. 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...

  10. Chromosome Aberration on High Level Background Natural Radiation Areas

    International Nuclear Information System (INIS)

    Yanti-Lusiyanti; Zubaidah-Alatas

    2001-01-01

    When the body is irradiated, all cells can suffer cytogenetic damage that can be seen as structural damage of chromosome in the lymphocytes. People no matter where they live in world are exposed to background radiation from natural sources both internal and external such as cosmic radiation, terrestrial radiation, cosmogenic radiation radon and thoron. Level of area natural ionizing radiation is varies depending on the altitude, the soil or rock conditions, particular food chains and the building materials and construction features. Level of normal areas of background exposure is annual effective dose 2.4 mSv and the high level areas of background exposure 20 mSv. This paper discuses the frequency of aberration chromosome especially dysenteries in several countries having high level radiation background. It seems that frequency of chromosome aberrations increase, generally with the increase of age of the people and the accumulated dose received. (author)

  11. 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.

  12. Anthropogenic transformation of the terrestrial biosphere.

    Science.gov (United States)

    Ellis, Erle C

    2011-03-13

    Human populations and their use of land have transformed most of the terrestrial biosphere into anthropogenic biomes (anthromes), causing a variety of novel ecological patterns and processes to emerge. To assess whether human populations and their use of land have directly altered the terrestrial biosphere sufficiently to indicate that the Earth system has entered a new geological epoch, spatially explicit global estimates of human populations and their use of land were analysed across the Holocene for their potential to induce irreversible novel transformation of the terrestrial biosphere. Human alteration of the terrestrial biosphere has been significant for more than 8000 years. However, only in the past century has the majority of the terrestrial biosphere been transformed into intensively used anthromes with predominantly novel anthropogenic ecological processes. At present, even were human populations to decline substantially or use of land become far more efficient, the current global extent, duration, type and intensity of human transformation of ecosystems have already irreversibly altered the terrestrial biosphere at levels sufficient to leave an unambiguous geological record differing substantially from that of the Holocene or any prior epoch. It remains to be seen whether the anthropogenic biosphere will be sustained and continue to evolve.

  13. Exposure to background radiation in Australia

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, S.B. [Australian Radiation Lab., Melbourne, VIC (Australia)

    1997-12-31

    The average effective dose received by the Australian population is estimated to be {approx}1.8 mSv / year. One half of this exposure arises from exposure from terrestrial radiation and cosmic rays, the remainder from radionuclides within the body and from inhalation of radon progeny. This paper reviews a number of research programmes carried out by the Australian Radiation Laboratory to study radiation exposure from natural background, particularly in the workplace and illustrate approaches to the quantification and management of exposure to natural radiation. The average radiation doses to the Australian population are relatively low; the average annual radon concentration ranged from 6 Bq m{sup -3} in Queensland to 16 Bq m{sup -3} in the Australian Capital Territory (ACT). Of more importance is the emerging issue of exposure to elevated background radiation in the workplace. Two situation are presented; the radiation exposure to air crues and show cave tour guides. Annual doses up to 3.8 mSv were estimated for international crew members while the highest estimate for show cave tour guides was 9 mSv per year. 9 refs., 2 tabs., 4 figs.

  14. Exposure to background radiation in Australia

    International Nuclear Information System (INIS)

    Solomon, S.B.

    1997-01-01

    The average effective dose received by the Australian population is estimated to be ∼1.8 mSv / year. One half of this exposure arises from exposure from terrestrial radiation and cosmic rays, the remainder from radionuclides within the body and from inhalation of radon progeny. This paper reviews a number of research programmes carried out by the Australian Radiation Laboratory to study radiation exposure from natural background, particularly in the workplace and illustrate approaches to the quantification and management of exposure to natural radiation. The average radiation doses to the Australian population are relatively low; the average annual radon concentration ranged from 6 Bq m -3 in Queensland to 16 Bq m -3 in the Australian Capital Territory (ACT). Of more importance is the emerging issue of exposure to elevated background radiation in the workplace. Two situation are presented; the radiation exposure to air crues and show cave tour guides. Annual doses up to 3.8 mSv were estimated for international crew members while the highest estimate for show cave tour guides was 9 mSv per year

  15. Natural background radiation exposures world-wide

    International Nuclear Information System (INIS)

    Bennett, B.G.

    1993-01-01

    The average radiation dose to the world's population from natural radiation sources has been assessed by UNSCEAR to be 2.4 mSv per year. The components of this exposure, methods of evaluation and, in particular, the variations in the natural background levels are presented in this paper. Exposures to cosmic radiation range from 0.26 mSv per year at sea level to 20 times more at an altitude of 6000 m. Exposures to cosmogenic radionuclides ( 3 H, 14 C) are relatively insignificant and little variable. The terrestrial radionuclides 40 K, 238 U, and 232 Th and the decay products of the latter two constitute the remainder of the natural radiation exposure. Wide variations in exposure occur for these components, particularly for radon and its decay products, which can accumulate to relatively high levels indoors. Unusually high exposures to uranium and thorium series radionuclides characterize the high natural background areas which occur in several localized regions in the world. Extreme values in natural radiation exposures have been estimated to range up to 100 times the average values. (author). 15 refs, 3 tabs

  16. Executive Summary - Historical background

    International Nuclear Information System (INIS)

    2005-01-01

    matter physics experiments at the High Flux Reactor of The Laue Langevin Institute and the ISIS spallation source at Rutherford-Appleton. Recently, we very actively entered the ICARUS neutrino collaboration and were invited to the PIERRE AUGER collaboration which will search for the highest energies in the Universe. Having close ties with CERN we are very actively engaged in CROSS-GRID, a large computer network project. To better understand the historical background of the INP development, it is necessary to add a few comments on financing of science in Poland. During the 70's and the 80's, research was financed through the so-called Central Research Projects for Science and Technical Development. The advantage of this system was that state-allocated research funds were divided only by a few representatives of the scientific community, which allowed realistic allocation of money to a small number of projects. After 1989 we were able to purchase commercially available equipment, which led to the closure of our large and very experienced electronic workshop. We also considerably reduced our well equipped mechanical shop. During the 90's the reduced state financing of science was accompanied by a newly established Committee of Scientific Research which led to the creation of a system of small research projects. This precluded the development of more ambitious research projects and led to the dispersion of equipment among many smaller laboratories and universities. A large research establishment, such as our Institute, could not develop properly under such conditions. In all, between 1989 and 2004 we reduced our personnel from about 800 to 470 and our infrastructure became seriously undercapitalised. However, with energetic search for research funds, from European rather than national research programs, we hope to improve and modernize our laboratories and their infrastructure in the coming years

  17. Background Model for the Majorana Demonstrator

    Science.gov (United States)

    Cuesta, C.; Abgrall, N.; Aguayo, E.; Avignone, F. T.; Barabash, A. S.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Byram, D.; Caldwell, A. S.; Chan, Y.-D.; Christofferson, C. D.; Combs, D. C.; Detwiler, J. A.; Doe, P. J.; Efremenko, Yu.; Egorov, V.; Ejiri, H.; Elliott, S. R.; Fast, J. E.; Finnerty, P.; Fraenkle, F. M.; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M. P.; Gruszko, J.; Guiseppe, V. E.; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, R.; Hoppe, E. W.; Howard, S.; Howe, M. A.; Keeter, K. J.; Kidd, M. F.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; Leon, J.; Leviner, L. E.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Martin, R. D.; Meijer, S.; Mertens, S.; Nomachi, M.; Orrell, J. L.; O'Shaughnessy, C.; Overman, N. R.; Phillips, D. G.; Poon, A. W. P.; Pushkin, K.; Radford, D. C.; Rager, J.; Rielage, K.; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, A. G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, K. J.; Snyder, N.; Suriano, A. M.; Thompson, J.; Timkin, V.; Tornow, W.; Trimble, J. E.; Varner, R. L.; Vasilyev, S.; Vetter, K.; Vorren, K.; White, B. R.; Wilkerson, J. F.; Wiseman, C.; Xu, W.; Yakushev, E.; Young, A. R.; Yu, C.-H.; Yumatov, V.

    The Majorana Collaboration is constructing a system containing 40 kg of HPGe detectors to demonstrate the feasibility and potential of a future tonne-scale experiment capable of probing the neutrino mass scale in the inverted-hierarchy region. To realize this, a major goal of the Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest around the Q-value at 2039 keV. This goal is pursued through a combination of a significant reduction of radioactive impurities in construction materials with analytical methods for background rejection, for example using powerful pulse shape analysis techniques profiting from the p-type point contact HPGe detectors technology. The effectiveness of these methods is assessed using simulations of the different background components whose purity levels are constrained from radioassay measurements.

  18. Casting light on harm reduction

    DEFF Research Database (Denmark)

    Jourdan, Michael

    2009-01-01

    Background: Harm reduction is commonly regarded as complementary to other drug problem responses - as the fourth tier. Yet even core examples of harm reduction such as the provision of injection equipment and methadone treatment has over and over encountered considerable opposition, and harm redu...

  19. 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)

  20. Background noise levels in Europe

    OpenAIRE

    Gjestland, Truls

    2008-01-01

    - This report gives a brief overview of typical background noise levels in Europe, and suggests a procedure for the prediction of background noise levels based on population density. A proposal for the production of background noise maps for Europe is included.

  1. Acclimation of a terrestrial plant to submergence facilitates gas exchange under water

    DEFF Research Database (Denmark)

    Mommer, L.; Pedersen, O.; Visser, E. J. W.

    2004-01-01

    Flooding imposes stress upon terrestrial plants since it severely hampers gas exchange rates between the shoot and the environment. The resulting oxygen deficiency is considered to be the major problem for submerged plants. Oxygen microelectrode studies have, however, shown that aquatic plants...... of this terrestrial plant species to submergence for gas exchange capacity is also shown. Shoot acclimation to submergence involved a reduction of the diffusion resistance to gases, which was not only functional by increasing diffusion of oxygen into the plant, but also by increasing influx of CO2, which enhances...... maintain relatively high internal oxygen pressures under water, and even may release oxygen via the roots into the sediment, also in dark. Based on these results, we challenge the dogma that oxygen pressures in submerged terrestrial plants immediately drop to levels at which aerobic respiration is impaired...

  2. Multi-model analysis of terrestrial carbon cycles in Japan: reducing uncertainties in model outputs among different terrestrial biosphere models using flux observations

    Science.gov (United States)

    Ichii, K.; Suzuki, T.; Kato, T.; Ito, A.; Hajima, T.; Ueyama, M.; Sasai, T.; Hirata, R.; Saigusa, N.; Ohtani, Y.; Takagi, K.

    2009-08-01

    Terrestrial biosphere models show large uncertainties when simulating carbon and water cycles, and reducing these uncertainties is a priority for developing more accurate estimates of both terrestrial ecosystem statuses and future climate changes. To reduce uncertainties and improve the understanding of these carbon budgets, we investigated the ability of flux datasets to improve model simulations and reduce variabilities among multi-model outputs of terrestrial biosphere models in Japan. Using 9 terrestrial biosphere models (Support Vector Machine-based regressions, TOPS, CASA, VISIT, Biome-BGC, DAYCENT, SEIB, LPJ, and TRIFFID), we conducted two simulations: (1) point simulations at four flux sites in Japan and (2) spatial simulations for Japan with a default model (based on original settings) and an improved model (based on calibration using flux observations). Generally, models using default model settings showed large deviations in model outputs from observation with large model-by-model variability. However, after we calibrated the model parameters using flux observations (GPP, RE and NEP), most models successfully simulated seasonal variations in the carbon cycle, with less variability among models. We also found that interannual variations in the carbon cycle are mostly consistent among models and observations. Spatial analysis also showed a large reduction in the variability among model outputs, and model calibration using flux observations significantly improved the model outputs. These results show that to reduce uncertainties among terrestrial biosphere models, we need to conduct careful validation and calibration with available flux observations. Flux observation data significantly improved terrestrial biosphere models, not only on a point scale but also on spatial scales.

  3. Association of Radon Background and Total Background Ionizing Radiation with Alzheimer's Disease Deaths in U.S. States.

    Science.gov (United States)

    Lehrer, Steven; Rheinstein, Peter H; Rosenzweig, Kenneth E

    2017-01-01

    Exposure of the brain to ionizing radiation might promote the development of Alzheimer's disease (AD). Analysis of AD death rates versus radon background radiation and total background radiation in U.S. states. Total background, radon background, cosmic and terrestrial background radiation measurements are from Assessment of Variations in Radiation Exposure in the United States and Report No. 160 - Ionizing Radiation Exposure of the Population of the United States. 2013 AD death rates by U.S. state are from the Alzheimer's Association. Radon background ionizing radiation was significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.467, p = 0.001). Total background ionizing radiation was also significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.452, p = 0.001). Multivariate linear regression weighted by state population demonstrated that AD death rate was significantly correlated with radon background (β= 0.169, p ionizing radiation is a risk factor for AD. Intranasal inhalation of radon gas could subject the rhinencephalon and hippocampus to damaging radiation that initiates AD. The damage would accumulate over time, causing age to be a powerful risk factor.

  4. Terrestrial Energy bets on molten salt reactors

    International Nuclear Information System (INIS)

    Anon.

    2015-01-01

    Terrestrial Energy is a Canadian enterprise, founded in 2013, for marketing the integral molten salt reactor (IMSR). A first prototype (called MSRE and with an energy output of 8 MW) was designed and operated between 1965 and 1969 by the Oak Ridge National Laboratory. IMSR is a small, modular reactor with a thermal energy output of 400 MW. According to Terrestrial Energy the technology of conventional power reactors is too complicated and too expensive. On the contrary IMSR's technology appears to be simple, easy to operate and affordable. With a staff of 30 people Terrestrial Energy appears to be a start-up in the nuclear sector. A process of pre-licensing will be launched in 2016 with the Canadian nuclear safety authority. (A.C.)

  5. Background radiation levels and medical exposure levels in Australia

    International Nuclear Information System (INIS)

    Webb, D.V.; Solomon, S.B.; Thomson, J.E.M.

    1999-01-01

    The average effective background dose received by the Australian population has been reassessed to be ∼1.5 millisievert (mSv) per year. Over half of this exposure arises from exposure from terrestrial radiation and cosmic rays, the remainder from radionuclides within the body and from inhalation of radon progeny. This background is to be compared with medical radiation, primarily diagnostic, which could add half as much again to the population exposure. This paper reviews research programmes carried out by the Australian Radiation Laboratory to study radiation exposure from natural background and from medical use. While the latter exposure is accepted to have a social benefit, there is a need to ensure that doses are no more than necessary to provide effective diagnosis and optimal treatment. Copyright (1999) Australasian Radiation Protection Society Inc

  6. 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

  7. Evolutionary tracks of the terrestrial planets

    International Nuclear Information System (INIS)

    Matsui, Takafumi; Abe, Yutaka

    1987-01-01

    On the basis of the model proposed by Matsui and Abe, the authors show that two major factors - distance from the Sun and the efficiency of retention of accretional energy - control the early evolution of the terrestrial planets. A diagram of accretional energy versus the optical depth of a proto-atmosphere provides a means to follow the evolutionary track of surface temperature of the terrestrial planets and an explanation for why the third planet in our solar system is an 'aqua'-planet. 15 refs; 3 figs

  8. Magnetic reconnection in the terrestrial magnetosphere

    International Nuclear Information System (INIS)

    Feldman, W.C.

    1984-01-01

    An overview is given of quantitative comparisons between measured phenomena in the terrestrial magnetosphere thought to be associated with magnetic reconnection, and related theoretical predictions based on Petschek's simple model. Although such a comparison cannot be comprehensive because of the extended nature of the process and the relatively few in situ multipoint measurements made to date, the agreement is impressive where comparisons have been possible. This result leaves little doubt that magnetic reconnection does indeed occur in the terrestrial magnetosphere. The maximum reconnection rate, expressed in terms of the inflow Mach number, M/sub A/, is measured to be M/sub A/ = 0.2 +- 0.1

  9. Terrestrial propagation of long electromagnetic waves

    CERN Document Server

    Galejs, Janis; Fock, V A

    2013-01-01

    Terrestrial Propagation of Long Electromagnetic Waves deals with the propagation of long electromagnetic waves confined principally to the shell between the earth and the ionosphere, known as the terrestrial waveguide. The discussion is limited to steady-state solutions in a waveguide that is uniform in the direction of propagation. Wave propagation is characterized almost exclusively by mode theory. The mathematics are developed only for sources at the ground surface or within the waveguide, including artificial sources as well as lightning discharges. This volume is comprised of nine chapte

  10. 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

  11. 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.

  12. Backgrounder

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    Center for Mountain Ecosystem Studies, Kunming Institute of Botany of the Chinese Academy of Sciences, China: $1,526,000 to inform effective water governance in the Asian highlands of China, Nepal, and Pakistan. • Ashoka Trust for Research in Ecology and the Environment (ATREE), India: $1,499,300 for research on ...

  13. BACKGROUNDER

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    demographic trends, socio-economic development pathways, and strong ... knowledge and experience, and encourage innovation. ... choices, and will work with stakeholders in government, business, civil society, and regional economic.

  14. Backgrounder

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    Safe and Inclusive Cities: ... improving urban environments and public spaces might have on reducing the city's high ... violence against women among urban youth of working class neighbourhoods of Islamabad, Rawalpindi, and Karachi,.

  15. BACKGROUNDER

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    CARIAA's research agenda addresses gaps and priorities highlighted in the ... Research focuses on climate risk, institutional and regulatory frameworks, markets, and ... The researchers will identify relevant drivers and trends and use develop ...

  16. BACKGROUNDER

    International Development Research Centre (IDRC) Digital Library (Canada)

    Corey Piccioni

    achieving long‐term food security in Africa, with a focus on post‐harvest loss, ... nutrion and health, and the socio‐economic factors that affect food supply ... Water use. Agricultural producvity in sub‐Saharan Africa is the lowest in the world.

  17. On the omnipresent background gamma radiation of the continuous spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Banjanac, R.; Maletić, D.; Joković, D., E-mail: yokovic@ipb.ac.rs; Veselinović, N.; Dragić, A.; Udovičić, V.; Aničin, I.

    2014-05-01

    The background spectrum of a germanium detector, shielded from the radiations arriving from the lower and open for the radiations arriving from the upper hemisphere, is studied by means of absorption measurements, both in a ground level and in an underground laboratory. The low-energy continuous portion of this background spectrum that peaks at around 100 keV, which is its most intense component, is found to be of very similar shape at the two locations. It is established that it is mostly due to the radiations of the real continuous spectrum, which is quite similar to the instrumental one. The intensity of this radiation is in our cases estimated to about 8000 photons/(m{sup 2}s·2π·srad) in the ground level laboratory, and to about 5000 photons/(m{sup 2}s·2π·srad) in the underground laboratory, at the depth of 25 m.w.e. Simulations by GEANT4 and CORSIKA demonstrate that this radiation is predominantly of terrestrial origin, due to environmental gamma radiations scattered off the materials that surround the detector (the “skyshine radiation”), and to a far less extent to cosmic rays of degraded energy. - Highlights: • We studied the low-energy part of continuous background spectra of germanium detectors. • The study was performed at the ground level and at the shallow underground sites. • The instrumental spectrum is due to radiations of the similar continuous spectrum. • The low-energy radiation is of both terrestrial and cosmic-ray origin. • In our study, we find that this radiation is of predominantly terrestrial origin.

  18. Terrestrial ecotoxicity of eight chemicals in a systematic approach

    Energy Technology Data Exchange (ETDEWEB)

    Hund-Rinke, K.; Simon, M. [Fraunhofer Inst. for Molecular Biology and Applied Ecology, Schmallenberg (Germany)

    2005-07-01

    Background and objective. Terrestrial ecotoxicity data are required for many research purposes. The data are derived either from the literature or elaborated by own investigations. As the terrestrial toxicity tests are usually time-consuming and labour intensive, the experiments are performed with a limited number of test organisms and soils. In the context of a project sponsored by CEFIC-LRI (European Chemical Industry Council - Long-Range Research Initiative), EC{sub 50}-values were systematically elaborated for eight chemicals with a wide range of logK{sub ow}-values (CdCl{sub 2}, Trinitrotoluene, 3,4-dichloroaniline, 2,4-dichlorophenol, Tributyltinchloride, Pentachlorophenol, Benzo(a)pyrene, p,p-dichloro-2,2-diphenyl-1,1,1-trichloroethane). The substances were selected covering a broad range of physico-chemical and ecotoxicological properties. As toxicity endpoints, microbial activities, plant germination and growth as well as reproduction of earthworms and collembola were determined. As such systematic investigations are rarely performed and for some substances no data existed, the data pool is made available to the scientific community. Methods. All toxicity tests were conducted on three different soil types (sandy soil, silty soil, loamy soil), according to ISO and OECD guidelines Results, discussion, conclusion and outlook. The different toxicities of the chemicals, the influence of soil properties on bioavailability as well as different sensitivities of test organisms and test parameters are reflected by the EC{sub 50}-values. The results showed that the EC{sub 50}-values calculated on the basis of nominal concentrations can significantly vary from EC{sub 50}-values derived from analytical concentrations for some substances. To avoid false conclusions, this has to be considered especially when concentrations determined in the field are compared with toxicity data obtained from the literature or calculated on the basis of nominal concentrations. Moreover

  19. 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.

  20. Diffuse Cosmic Infrared Background Radiation

    Science.gov (United States)

    Dwek, Eli

    2002-01-01

    The diffuse cosmic infrared background (CIB) consists of the cumulative radiant energy released in the processes of structure formation that have occurred since the decoupling of matter and radiation following the Big Bang. In this lecture I will review the observational data that provided the first detections and limits on the CIB, and the theoretical studies explaining the origin of this background. Finally, I will also discuss the relevance of this background to the universe as seen in high energy gamma-rays.

  1. Background current of radioisotope manometer

    International Nuclear Information System (INIS)

    Vydrik, A.A.

    1987-01-01

    The technique for calculating the main component of the background current of radioisotopic monometers, current from direct collision of ionizing particles and a collector, is described. The reasons for appearance of background photoelectron current are clarified. The most effective way of eliminating background current components is collector protection from the source by a screen made of material with a high gamma-quanta absorption coefficient, such as lead, for example

  2. Transuranic elements in terrestrial animals and the environment: an introduction

    International Nuclear Information System (INIS)

    Potter, G.D.

    1977-01-01

    This discussion provides background information to the session on the ''Transuranic Elements in Terrestrial Animals.'' Briefly outlined are some of the historical events leading to the introduction and dispersion of the transuranic elements into the biosphere, to the establishment of the Nevada Applied Ecology Group (NAEG), and to the studies conducted by the Environmental Monitoring and Support Laboratory (EMSL-LV) and the University of Nevada-Las Vegas involving the transuranics distributed by the ''safety shots'' and the nuclear weapons testing program at the Nevada Test Site and the Tonopah Test Range. These studies are described in relation to the overall objectives of the NAEG program. Other potential sources of the transuranic radionuclides are also discussed

  3. Reduction corporoplasty.

    Science.gov (United States)

    Hakky, Tariq S; Martinez, Daniel; Yang, Christopher; Carrion, Rafael E

    2015-01-01

    Here we present the first video demonstration of reduction corporoplasty in the management of phallic disfigurement in a 17 year old man with a history sickle cell disease and priapism. Surgical management of aneurysmal dilation of the corpora has yet to be defined in the literature. We preformed bilateral elliptical incisions over the lateral corpora as management of aneurysmal dilation of the corpora to correct phallic disfigurement. The patient tolerated the procedure well and has resolution of his corporal disfigurement. Reduction corporoplasty using bilateral lateral elliptical incisions in the management of aneurysmal dilation of the corpora is a safe an feasible operation in the management of phallic disfigurement.

  4. Background subtraction theory and practice

    CERN Document Server

    Elgammal, Ahmed

    2014-01-01

    Background subtraction is a widely used concept for detection of moving objects in videos. In the last two decades there has been a lot of development in designing algorithms for background subtraction, as well as wide use of these algorithms in various important applications, such as visual surveillance, sports video analysis, motion capture, etc. Various statistical approaches have been proposed to model scene backgrounds. The concept of background subtraction also has been extended to detect objects from videos captured from moving cameras. This book reviews the concept and practice of back

  5. Forest inventory with terrestrial LiDAR

    NARCIS (Netherlands)

    Bauwens, Sébastien; Bartholomeus, Harm; Calders, Kim; Lejeune, Philippe

    2016-01-01

    The application of static terrestrial laser scanning (TLS) in forest inventories is becoming more effective. Nevertheless, the occlusion effect is still limiting the processing efficiency to extract forest attributes. The use of a mobile laser scanner (MLS) would reduce this occlusion. In this

  6. High efficiency, long life terrestrial solar panel

    Science.gov (United States)

    Chao, T.; Khemthong, S.; Ling, R.; Olah, S.

    1977-01-01

    The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evaluation of the cell performance was begun. Based on the power output analysis, the goal of a 13% efficiency module was achievable.

  7. Solar and terrestrial radiation: methods and measurements

    National Research Council Canada - National Science Library

    Coulson, Kinsell L

    1975-01-01

    ... AND RETRIEVAL SYSTEM, WITHOUT PERMISSION IN WRITING FROM THE PUBLISHER. ACADEMIC PRESS, INC. Ill Fifth Avenue, New York, New York 10003 United Kingdom Edition published by A C A D E M I C PRESS, INC. (LONDON) LTD. 24/28 Oval Road, London NW1 Library of Congress Cataloging in Publication Data Coulson, Kinsell L Solar and terrestrial radiation. Inclu...

  8. Strategies for monitoring terrestrial animals and habitats

    Science.gov (United States)

    Richard Holthausen; Raymond L. Czaplewski; Don DeLorenzo; Greg Hayward; Winifred B. Kessler; Pat Manley; Kevin S. McKelvey; Douglas S. Powell; Leonard F. Ruggiero; Michael K. Schwartz; Bea Van Horne; Christina D. Vojta

    2005-01-01

    This General Technical Report (GTR) addresses monitoring strategies for terrestrial animals and habitats. It focuses on monitoring associated with National Forest Management Act planning and is intended to apply primarily to monitoring efforts that are broader than individual National Forests. Primary topics covered in the GTR are monitoring requirements; ongoing...

  9. South African red data book - Terrestrial mammals

    CSIR Research Space (South Africa)

    Smithers, RHN

    1986-01-01

    Full Text Available Currently, 243 species of terrestrial wild mammals are known to occur in the Republic of South Africa. Using the well established IUCN definitions, 42 of these may be considered as exposed to some level of threat of extinction. Three species...

  10. Furostanol and Spirostanol Saponins from Tribulus terrestris.

    Science.gov (United States)

    Wang, Zhen-Fang; Wang, Bing-Bing; Zhao, Yang; Wang, Fang-Xu; Sun, Yan; Guo, Rui-Jie; Song, Xin-Bo; Xin, Hai-Li; Sun, Xin-Guang

    2016-03-30

    Twelve new steroidal saponins, including eleven furostanol saponins, terrestrinin J-T (1-11), and one spirostanol saponin, terrestrinin U (12), together with seven known steroidal saponins 13-19 were isolated from T. terrestris. The structures of the new compounds were established on the basis of spectroscopic data, including 1D and 2D NMR and HRESIMS, and comparisons with published data.

  11. Terrestrial water fluxes dominated by transpiration: Comment

    Science.gov (United States)

    Daniel R. Schlaepfer; Brent E. Ewers; Bryan N. Shuman; David G. Williams; John M. Frank; William J. Massman; William K. Lauenroth

    2014-01-01

    The fraction of evapotranspiration (ET) attributed to plant transpiration (T) is an important source of uncertainty in terrestrial water fluxes and land surface modeling (Lawrence et al. 2007, Miralles et al. 2011). Jasechko et al. (2013) used stable oxygen and hydrogen isotope ratios from 73 large lakes to investigate the relative roles of evaporation (E) and T in ET...

  12. 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 ...

  13. Terrestrial gamma radiation baseline mapping using ultra low density sampling methods

    International Nuclear Information System (INIS)

    Kleinschmidt, R.; Watson, D.

    2016-01-01

    Baseline terrestrial gamma radiation maps are indispensable for providing basic reference information that may be used in assessing the impact of a radiation related incident, performing epidemiological studies, remediating land contaminated with radioactive materials, assessment of land use applications and resource prospectivity. For a large land mass, such as Queensland, Australia (over 1.7 million km 2 ), it is prohibitively expensive and practically difficult to undertake detailed in-situ radiometric surveys of this scale. It is proposed that an existing, ultra-low density sampling program already undertaken for the purpose of a nationwide soil survey project be utilised to develop a baseline terrestrial gamma radiation map. Geoelement data derived from the National Geochemistry Survey of Australia (NGSA) was used to construct a baseline terrestrial gamma air kerma rate map, delineated by major drainage catchments, for Queensland. Three drainage catchments (sampled at the catchment outlet) spanning low, medium and high radioelement concentrations were selected for validation of the methodology using radiometric techniques including in-situ measurements and soil sampling for high resolution gamma spectrometry, and comparative non-radiometric analysis. A Queensland mean terrestrial air kerma rate, as calculated from the NGSA outlet sediment uranium, thorium and potassium concentrations, of 49 ± 69 nGy h −1 (n = 311, 3σ 99% confidence level) is proposed as being suitable for use as a generic terrestrial air kerma rate background range. Validation results indicate that catchment outlet measurements are representative of the range of results obtained across the catchment and that the NGSA geoelement data is suitable for calculation and mapping of terrestrial air kerma rate. - Highlights: • A baseline terrestrial air kerma map of Queensland, Australia was developed using geochemical data from a major drainage catchment ultra-low density sampling program

  14. Hanford Site background: Part 1, Soil background for nonradioactive analytes

    International Nuclear Information System (INIS)

    1993-04-01

    The determination of soil background is one of the most important activities supporting environmental restoration and waste management on the Hanford Site. Background compositions serve as the basis for identifying soil contamination, and also as a baseline in risk assessment processes used to determine soil cleanup and treatment levels. These uses of soil background require an understanding of the extent to which analytes of concern occur naturally in the soils. This report documents the results of sampling and analysis activities designed to characterize the composition of soil background at the Hanford Site, and to evaluate the feasibility for use as Sitewide background. The compositions of naturally occurring soils in the vadose Zone have been-determined for-nonradioactive inorganic and organic analytes and related physical properties. These results confirm that a Sitewide approach to the characterization of soil background is technically sound and is a viable alternative to the determination and use of numerous local or area backgrounds that yield inconsistent definitions of contamination. Sitewide soil background consists of several types of data and is appropriate for use in identifying contamination in all soils in the vadose zone on the Hanford Site. The natural concentrations of nearly every inorganic analyte extend to levels that exceed calculated health-based cleanup limits. The levels of most inorganic analytes, however, are well below these health-based limits. The highest measured background concentrations occur in three volumetrically minor soil types, the most important of which are topsoils adjacent to the Columbia River that are rich in organic carbon. No organic analyte levels above detection were found in any of the soil samples

  15. Backgrounds and characteristics of arsonists

    NARCIS (Netherlands)

    Labree, W.; Nijman, H.L.I.; Marle, H.J.C. van; Rassin, E.

    2010-01-01

    The aim of this study was to gain more insight in the backgrounds and characteristics of arsonists. For this, the psychiatric, psychological, personal, and criminal backgrounds of all arsonists (n = 25), sentenced to forced treatment in the maximum security forensic hospital “De Kijvelanden”, were

  16. Measurement of natural background neutron

    CERN Document Server

    Li Jain, Ping; Tang Jin Hua; Tang, E S; Xie Yan Fong

    1982-01-01

    A high sensitive neutron monitor is described. It has an approximate counting rate of 20 cpm for natural background neutrons. The pulse amplitude resolution, sensitivity and direction dependence of the monitor were determined. This monitor has been used for natural background measurement in Beijing area. The yearly average dose is given and compared with the results of KEK and CERN.

  17. Louisiana ESI: T_MAMMAL (Terrestrial Mammal Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for terrestrial mammals in Louisiana. Vector polygons in this data set represent terrestrial mammal...

  18. Aluminum as a source of background in low background experiments

    Energy Technology Data Exchange (ETDEWEB)

    Majorovits, B., E-mail: bela@mppmu.mpg.de [MPI fuer Physik, Foehringer Ring 6, 80805 Munich (Germany); Abt, I. [MPI fuer Physik, Foehringer Ring 6, 80805 Munich (Germany); Laubenstein, M. [Laboratori Nazionali del Gran Sasso, INFN, S.S.17/bis, km 18 plus 910, I-67100 Assergi (Italy); Volynets, O. [MPI fuer Physik, Foehringer Ring 6, 80805 Munich (Germany)

    2011-08-11

    Neutrinoless double beta decay would be a key to understanding the nature of neutrino masses. The next generation of High Purity Germanium experiments will have to be operated with a background rate of better than 10{sup -5} counts/(kg y keV) in the region of interest around the Q-value of the decay. Therefore, so far irrelevant sources of background have to be considered. The metalization of the surface of germanium detectors is in general done with aluminum. The background from the decays of {sup 22}Na, {sup 26}Al, {sup 226}Ra and {sup 228}Th introduced by this metalization is discussed. It is shown that only a special selection of aluminum can keep these background contributions acceptable.

  19. The limits to global-warming mitigation by terrestrial carbon removal

    OpenAIRE

    Boysen, L.; Lucht, W.; Gerten, D.; Heck, V.; Lenton, T.; Schellnhuber, H.

    2017-01-01

    Massive near-term greenhouse gas emissions reduction is a precondition for staying "well below 2°C" global warming as envisaged by the Paris Agreement. Furthermore, extensive terrestrial carbon dioxide removal (tCDR) through managed biomass growth and subsequent carbon capture and storage is required to avoid temperature "overshoot" in most pertinent scenarios. Here, we address two major issues: First, we calculate the extent of tCDR required to "repair" delayed or insufficient emissions redu...

  20. Can polar bears use terrestrial foods to offset lost ice-based hunting opportunities?

    OpenAIRE

    Rode, Karyn D.; Robbins, Charles T.; Nelson, Lynne; Amstrup, Steven C.

    2015-01-01

    Increased land use by polar bears (Ursus maritimus) due to climate‐change‐induced reduction of their sea‐ice habitat illustrates the impact of climate change on species distributions and the difficulty of conserving a large, highly specialized carnivore in the face of this global threat. Some authors have suggested that terrestrial food consumption by polar bears will help them withstand sea‐ice loss as they are forced to spend increasing amounts of time on land. Here, we evaluate the nutriti...

  1. Impacts of droughts on carbon sequestration by China's terrestrial ecosystems from 2000 to 2011

    Science.gov (United States)

    Liu, Y.; Zhou, Y.; Ju, W.; Wang, S.; Wu, X.; He, M.; Zhu, G.

    2014-05-01

    In recent years, China's terrestrial ecosystems have experienced frequent droughts. How these droughts have affected carbon sequestration by the terrestrial ecosystems is still unclear. In this study, the process-based Boreal Ecosystem Productivity Simulator (BEPS) model, driven by remotely sensed vegetation parameters, was employed to assess the effects of droughts on net ecosystem productivity (NEP) of terrestrial ecosystems in China from 2000 to 2011. Droughts of differing severity, as indicated by a standard precipitation index (SPI), hit terrestrial ecosystems in China extensively in 2001, 2006, 2009, and 2011. The national total annual NEP exhibited the slight decline of -11.3 Tg C yr-2 during the aforementioned years of extensive droughts. The NEP reduction ranged from 61.1 Tg C yr-1 to 168.8 Tg C yr-1. National and regional total NEP anomalies were correlated with the annual mean SPI, especially in Northwest China, North China, Central China, and Southwest China. The reductions in annual NEP in 2001 and 2011 might have been caused by a larger decrease in annual gross primary productivity (GPP) than in annual ecosystem respiration (ER). The reductions experienced in 2009 might be due to a decrease in annual GPP and an increase in annual ER, while reductions in 2006 could stem from a larger increase in ER than in GPP. The effects of droughts on NEP lagged up to 3-6 months, due to different responses of GPP and ER. In eastern China, where is humid and warm, droughts have predominant and short-term lagged influences on NEP. In western regions, cold and arid, the drought effects on NEP were relatively weaker but prone to lasting longer.

  2. Terrestrial forest management plan for Palmyra Atoll

    Science.gov (United States)

    Hathaway, Stacie A.; McEachern, Kathryn; Fisher, Robert N.

    2011-01-01

    This 'Terrestrial Forest Management Plan for Palmyra Atoll' was developed by the U.S. Geological Survey (USGS) for The Nature Conservancy (TNC) Palmyra Program to refine and expand goals and objectives developed through the Conservation Action Plan process. It is one in a series of adaptive management plans designed to achieve TNC's mission toward the protection and enhancement of native wildlife and habitat. The 'Terrestrial Forest Management Plan for Palmyra Atoll' focuses on ecosystem integrity and specifically identifies and addresses issues related to assessing the status and distribution of resources, as well as the pressures acting upon them, most specifically nonnative and potentially invasive species. The plan, which presents strategies for increasing ecosystem integrity, provides a framework to implement and track the progress of conservation and restoration goals related to terrestrial resources on Palmyra Atoll. The report in its present form is intended to be an overview of what is known about historical and current forest resources; it is not an exhaustive review of all available literature relevant to forest management but an attempt to assemble as much information specific to Palmyra Atoll as possible. Palmyra Atoll is one of the Northern Line Islands in the Pacific Ocean southwest of the Hawai`ian Islands. It consists of many heavily vegetated islets arranged in a horseshoe pattern around four lagoons and surrounded by a coral reef. The terrestrial ecosystem consists of three primary native vegetation types: Pisonia grandis forest, coastal strand forest, and grassland. Among these vegetation types, the health and extent of Pisonia grandis forest is of particular concern. Overall, the three vegetation types support 25 native plant species (two of which may be extirpated), 14 species of sea birds, six shore birds, at least one native reptile, at least seven native insects, and six native land crabs. Green and hawksbill turtles forage at Palmyra Atoll

  3. JEM-X background models

    DEFF Research Database (Denmark)

    Huovelin, J.; Maisala, S.; Schultz, J.

    2003-01-01

    Background and determination of its components for the JEM-X X-ray telescope on INTEGRAL are discussed. A part of the first background observations by JEM-X are analysed and results are compared to predictions. The observations are based on extensive imaging of background near the Crab Nebula...... on revolution 41 of INTEGRAL. Total observing time used for the analysis was 216 502 s, with the average of 25 cps of background for each of the two JEM-X telescopes. JEM-X1 showed slightly higher average background intensity than JEM-X2. The detectors were stable during the long exposures, and weak orbital...... background was enhanced in the central area of a detector, and it decreased radially towards the edge, with a clear vignetting effect for both JEM-X units. The instrument background was weakest in the central area of a detector and showed a steep increase at the very edges of both JEM-X detectors...

  4. Reduction Corporoplasty

    Directory of Open Access Journals (Sweden)

    Tariq S. Hakky

    2015-04-01

    Full Text Available Objective Here we present the first video demonstration of reduction corporoplasty in the management of phallic disfigurement in a 17 year old man with a history sickle cell disease and priapism. Introduction Surgical management of aneurysmal dilation of the corpora has yet to be defined in the literature. Materials and Methods: We preformed bilateral elliptical incisions over the lateral corpora as management of aneurysmal dilation of the corpora to correct phallic disfigurement. Results The patient tolerated the procedure well and has resolution of his corporal disfigurement. Conclusions Reduction corporoplasty using bilateral lateral elliptical incisions in the management of aneurysmal dilation of the corpora is a safe an feasible operation in the management of phallic disfigurement.

  5. Terrestrial gamma radiation baseline mapping using ultra low density sampling methods.

    Science.gov (United States)

    Kleinschmidt, R; Watson, D

    2016-01-01

    Baseline terrestrial gamma radiation maps are indispensable for providing basic reference information that may be used in assessing the impact of a radiation related incident, performing epidemiological studies, remediating land contaminated with radioactive materials, assessment of land use applications and resource prospectivity. For a large land mass, such as Queensland, Australia (over 1.7 million km(2)), it is prohibitively expensive and practically difficult to undertake detailed in-situ radiometric surveys of this scale. It is proposed that an existing, ultra-low density sampling program already undertaken for the purpose of a nationwide soil survey project be utilised to develop a baseline terrestrial gamma radiation map. Geoelement data derived from the National Geochemistry Survey of Australia (NGSA) was used to construct a baseline terrestrial gamma air kerma rate map, delineated by major drainage catchments, for Queensland. Three drainage catchments (sampled at the catchment outlet) spanning low, medium and high radioelement concentrations were selected for validation of the methodology using radiometric techniques including in-situ measurements and soil sampling for high resolution gamma spectrometry, and comparative non-radiometric analysis. A Queensland mean terrestrial air kerma rate, as calculated from the NGSA outlet sediment uranium, thorium and potassium concentrations, of 49 ± 69 nGy h(-1) (n = 311, 3σ 99% confidence level) is proposed as being suitable for use as a generic terrestrial air kerma rate background range. Validation results indicate that catchment outlet measurements are representative of the range of results obtained across the catchment and that the NGSA geoelement data is suitable for calculation and mapping of terrestrial air kerma rate. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  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. Dragon's paradise lost: palaeobiogeography, evolution and extinction of the largest-ever terrestrial lizards (Varanidae.

    Directory of Open Access Journals (Sweden)

    Scott A Hocknull

    Full Text Available BACKGROUND: The largest living lizard species, Varanus komodoensis Ouwens 1912, is vulnerable to extinction, being restricted to a few isolated islands in eastern Indonesia, between Java and Australia, where it is the dominant terrestrial carnivore. Understanding how large-bodied varanids responded to past environmental change underpins long-term management of V. komodoensis populations. METHODOLOGY/PRINCIPAL FINDINGS: We reconstruct the palaeobiogeography of Neogene giant varanids and identify a new (unnamed species from the island of Timor. Our data reject the long-held perception that V. komodoensis became a giant because of insular evolution or as a specialist hunter of pygmy Stegodon. Phyletic giantism, coupled with a westward dispersal from mainland Australia, provides the most parsimonious explanation for the palaeodistribution of V. komodoensis and the newly identified species of giant varanid from Timor. Pliocene giant varanid fossils from Australia are morphologically referable to V. komodoensis suggesting an ultimate origin for V. komodoensis on mainland Australia (>3.8 million years ago. Varanus komodoensis body size has remained stable over the last 900,000 years (ka on Flores, a time marked by major faunal turnovers, extinction of the island's megafauna, the arrival of early hominids by 880 ka, co-existence with Homo floresiensis, and the arrival of modern humans by 10 ka. Within the last 2000 years their populations have contracted severely. CONCLUSIONS/SIGNIFICANCE: Giant varanids were once a ubiquitous part of Subcontinental Eurasian and Australasian faunas during the Neogene. Extinction played a pivotal role in the reduction of their ranges and diversity throughout the late Quaternary, leaving only V. komodoensis as an isolated long-term survivor. The events over the last two millennia now threaten its future survival.

  8. A cosmic microwave background feature consistent with a cosmic texture.

    Science.gov (United States)

    Cruz, M; Turok, N; Vielva, P; Martínez-González, E; Hobson, M

    2007-12-07

    The Cosmic Microwave Background provides our most ancient image of the universe and our best tool for studying its early evolution. Theories of high-energy physics predict the formation of various types of topological defects in the very early universe, including cosmic texture, which would generate hot and cold spots in the Cosmic Microwave Background. We show through a Bayesian statistical analysis that the most prominent 5 degrees -radius cold spot observed in all-sky images, which is otherwise hard to explain, is compatible with having being caused by a texture. From this model, we constrain the fundamental symmetry-breaking energy scale to be (0) approximately 8.7 x 10(15) gigaelectron volts. If confirmed, this detection of a cosmic defect will probe physics at energies exceeding any conceivable terrestrial experiment.

  9. Stochastic backgrounds of gravitational waves

    International Nuclear Information System (INIS)

    Maggiore, M.

    2001-01-01

    We review the motivations for the search for stochastic backgrounds of gravitational waves and we compare the experimental sensitivities that can be reached in the near future with the existing bounds and with the theoretical predictions. (author)

  10. Berkeley Low Background Counting Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Sensitive low background assay detectors and sample analysis are available for non-destructive direct gamma-ray assay of samples. Neutron activation analysis is also...

  11. Spectral characterization of natural backgrounds

    Science.gov (United States)

    Winkelmann, Max

    2017-10-01

    As the distribution and use of hyperspectral sensors is constantly increasing, the exploitation of spectral features is a threat for camouflaged objects. To improve camouflage materials at first the spectral behavior of backgrounds has to be known to adjust and optimize the spectral reflectance of camouflage materials. In an international effort, the NATO CSO working group SCI-295 "Development of Methods for Measurements and Evaluation of Natural Background EO Signatures" is developing a method how this characterization of backgrounds has to be done. It is obvious that the spectral characterization of a background will be quite an effort. To compare and exchange data internationally the measurements will have to be done in a similar way. To test and further improve this method an international field trial has been performed in Storkow, Germany. In the following we present first impressions and lessons learned from this field campaign and describe the data that has been measured.

  12. Optimal Background Attenuation for Fielded Spectroscopic Detection Systems

    International Nuclear Information System (INIS)

    Robinson, Sean M.; Ashbaker, Eric D.; Schweppe, John E.; Siciliano, Edward R.

    2007-01-01

    Radiation detectors are often placed in positions difficult to shield from the effects of terrestrial background gamma radiation. This is particularly true in the case of Radiation Portal Monitor (RPM) systems, as their wide viewing angle and outdoor installations make them susceptible to radiation from the surrounding area. Reducing this source of background can improve gross-count detection capabilities in the current generation of non-spectroscopic RPM's as well as source identification capabilities in the next generation of spectroscopic RPM's. To provide guidance for designing such systems, the problem of shielding a general spectroscopic-capable RPM system from terrestrial gamma radiation is considered. This analysis is carried out by template matching algorithms, to determine and isolate a set of non-threat isotopes typically present in the commerce stream. Various model detector and shielding scenarios are calculated using the Monte-Carlo N Particle (MCNP) computer code. Amounts of nominal-density shielding needed to increase the probability of detection for an ensemble of illicit sources are given. Common shielding solutions such as steel plating are evaluated based on the probability of detection for 3 particular illicit sources of interest, and the benefits are weighed against the incremental cost of shielding. Previous work has provided optimal shielding scenarios for RPMs based on gross-counting measurements, and those same solutions (shielding the internal detector cavity, direct shielding of the ground between the detectors, and the addition of collimators) are examined with respect to their utility to improving spectroscopic detection

  13. Cosmic microwave background, where next?

    CERN Multimedia

    CERN. Geneva

    2009-01-01

    Ground-based, balloon-borne and space-based experiments will observe the Cosmic Microwave Background in greater details to address open questions about the origin and the evolution of the Universe. In particular, detailed observations the polarization pattern of the Cosmic Microwave Background radiation have the potential to directly probe physics at the GUT scale and illuminate aspects of the physics of the very early Universe.

  14. Terrestrial ecosystems in a changing world

    Energy Technology Data Exchange (ETDEWEB)

    Canadell, J.G. [CSIRO Marine and Atmospheric Research, Canberra, ACT (Australia). Global Carbon Project; Pataki, D.E. [California Univ., Irvine, CA (United States). Dept. of Earth System Science]|[California Univ., Irvine, CA (United States). Dept. of Ecology and Evolutionary Biology; Pitelka, L.F. (eds.) [Maryland Univ., Frostburg, MD (United States). Appalachian Lab.

    2007-07-01

    Over 100 authors present 25 contributions on the impacts of global change on terrestrial ecosystems including: * key processes of the earth system such as the CO2 fertilization effect, shifts in disturbances and biome distribution, the saturation of the terrestrial carbon sink, and changes in functional biodiversity, * ecosystem services such the production of wheat, pest control, and carbon storage in croplands, and * sensitive regions in the world threaten by rapid changes in climate and land use such as high latitudes ecosystems, tropical forest in Southeast Asia, and ecosystems dominated by Monsoon climate. The book also explores new research developments on spatial thresholds and nonlinearities, the key role of urban development in global biogeochemical processes, and the integration of natural and social sciences to address complex problems of the human-environment system. (orig.)

  15. 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...

  16. Application of Terrestrial Environments in Orion Assessments

    Science.gov (United States)

    Barbre, Robert E.

    2016-01-01

    This presentation summarizes the Marshall Space Flight Center Natural Environments Terrestrial and Planetary Environments (TPE) Team support to the NASA Orion space vehicle. The TPE utilizes meteorological data to assess the sensitivities of the vehicle due to the terrestrial environment. The Orion vehicle, part of the Multi-Purpose Crew Vehicle Program, is designed to carry astronauts beyond low-earth orbit and is currently undergoing a series of tests including Exploration Test Flight (EFT) - 1. The presentation describes examples of TPE support for vehicle design and several tests, as well as support for EFT-1 and planning for upcoming Exploration Missions while emphasizing the importance of accounting for the natural environment's impact to the vehicle early in the vehicle's program.

  17. Spiral arms, comets and terrestrial catastrophism

    International Nuclear Information System (INIS)

    Clube, S.V.M.; Napier, W.M.

    1982-01-01

    A review is presented of an hypothesis of terrestrial catastrophism in which comets grow in molecular clouds and are captured by the Sun as it passes through the spiral arms of the Galaxy. Assuming that comets are a major supplier of the Earth-crossing (Appollo) asteroid population, the latter fluctuates correspondingly and leads to episodes of terrestrial bombardment. Changes in the rotational momentum of core and mantle, generated by impacts, lead to episodes of magnetic field reversal and tectonic activity, while surface phenomena lead to ice-ages and mass extinctions. An episodic geophysical history with an interstellar connection is thus implied. If comets in spiral arms are necessary intermediaries in the process of star formation, the theory also has implications relating to early solar system history and galactic chemistry. These aspects are briefly discussed with special reference to the nature of spiral arms. (author)

  18. The circumpolar biodiversity monitoring program - Terrestrial plan

    DEFF Research Database (Denmark)

    Christensen, Tom; Payne, J.; Doyle, M.

    , northern communities, and scientists to detect, understand and report on long-term change in Arctic terrestrial ecosystems and biodiversity. This presentation will outline the key management questions the plan aims to address and the proposed nested, multi-scaled approach linking targeted, research based...... monitoring with survey-based monitoring and remotely sensed data. The CBMP Terrestrial Plan intends to build upon and expand existing monitoring networks, engaging participants across a range of capacity and interests. The presentation will summarize the recommended focal soil ecosystem components...... and attributes to monitor in the plan related to soil invertebrates. Focal Ecosystem Components (FECs) of the soil decomposer system include the soil living invertebrates such as microarthropods, enchytraeids and earthworms and the functions performed by microorganisms such as nitrification, decomposition...

  19. MAFF monitoring of the terrestrial environment

    International Nuclear Information System (INIS)

    Sherlock, J.C.

    1993-01-01

    This paper addresses the food surveillance programme of the Ministry of Agriculture, Fisheries and Food (MAFF), in particular the Terrestrial Radioactivity Monitoring Programme (TRAMP) and the estimation of dietary intake of radionuclides. To define the surveillance programme the following issues need to be decided upon: 1) the type of food which should be analysed; 2) the nature of the contaminants which should be analysed; and 3) the geographical location from which the food samples should be taken. (author)

  20. A molecular palaeobiological exploration of arthropod terrestrialization

    DEFF Research Database (Denmark)

    Lozano-Fernandez, Jesus; Carton, Robert; Tanner, Alastair R.

    2016-01-01

    to the colonization of land is the most likely scenario.Molecular clock analyses confirmed an origin for the three terrestrial lineages bracketed between the Cambrian and the Silurian. While molecular divergence times for Arachnida are consistent with the fossil record,Myriapoda are inferred to have colonized land......, consistent with morphological arguments for convergence in tracheal systems. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’....

  1. Astrophysical and terrestrial neutrinos in Supernova detectors

    International Nuclear Information System (INIS)

    Lagage, P.O.

    1985-09-01

    Supernova (SN) explosions are the place of very fundamental phenomena, whose privileged messengers are neutrinos. But such events are very rare. Then, SN detection has to be combined with other purposes. The recent developments of SN detectors have been associated with developments of underground particle physics (proton decay, monopoles ...). But here, I will restrict myself to discuss the possibilities for a supernova detector to be sensitive to other sources of neutrinos, astrophysical or terrestrial

  2. Furostanol and Spirostanol Saponins from Tribulus terrestris

    Directory of Open Access Journals (Sweden)

    Zhen-Fang Wang

    2016-03-01

    Full Text Available Twelve new steroidal saponins, including eleven furostanol saponins, terrestrinin J–T (1–11, and one spirostanol saponin, terrestrinin U (12, together with seven known steroidal saponins 13–19 were isolated from T. terrestris. The structures of the new compounds were established on the basis of spectroscopic data, including 1D and 2D NMR and HRESIMS, and comparisons with published data.

  3. Sampling Terrestrial Environments for Bacterial Polyketides

    Directory of Open Access Journals (Sweden)

    Patrick Hill

    2017-04-01

    Full Text Available Bacterial polyketides are highly biologically active molecules that are frequently used as drugs, particularly as antibiotics and anticancer agents, thus the discovery of new polyketides is of major interest. Since the 1980s discovery of polyketides has slowed dramatically due in large part to the repeated rediscovery of known compounds. While recent scientific and technical advances have improved our ability to discover new polyketides, one key area has been under addressed, namely the distribution of polyketide-producing bacteria in the environment. Identifying environments where producing bacteria are abundant and diverse should improve our ability to discover (bioprospect new polyketides. This review summarizes for the bioprospector the state-of-the-field in terrestrial microbial ecology. It provides insight into the scientific and technical challenges limiting the application of microbial ecology discoveries for bioprospecting and summarizes key developments in the field that will enable more effective bioprospecting. The major recent efforts by researchers to sample new environments for polyketide discovery is also reviewed and key emerging environments such as insect associated bacteria, desert soils, disease suppressive soils, and caves are highlighted. Finally strategies for taking and characterizing terrestrial samples to help maximize discovery efforts are proposed and the inclusion of non-actinomycetal bacteria in any terrestrial discovery strategy is recommended.

  4. Terrestrial water fluxes dominated by transpiration.

    Science.gov (United States)

    Jasechko, Scott; Sharp, Zachary D; Gibson, John J; Birks, S Jean; Yi, Yi; Fawcett, Peter J

    2013-04-18

    Renewable fresh water over continents has input from precipitation and losses to the atmosphere through evaporation and transpiration. Global-scale estimates of transpiration from climate models are poorly constrained owing to large uncertainties in stomatal conductance and the lack of catchment-scale measurements required for model calibration, resulting in a range of predictions spanning 20 to 65 per cent of total terrestrial evapotranspiration (14,000 to 41,000 km(3) per year) (refs 1, 2, 3, 4, 5). Here we use the distinct isotope effects of transpiration and evaporation to show that transpiration is by far the largest water flux from Earth's continents, representing 80 to 90 per cent of terrestrial evapotranspiration. On the basis of our analysis of a global data set of large lakes and rivers, we conclude that transpiration recycles 62,000 ± 8,000 km(3) of water per year to the atmosphere, using half of all solar energy absorbed by land surfaces in the process. We also calculate CO2 uptake by terrestrial vegetation by connecting transpiration losses to carbon assimilation using water-use efficiency ratios of plants, and show the global gross primary productivity to be 129 ± 32 gigatonnes of carbon per year, which agrees, within the uncertainty, with previous estimates. The dominance of transpiration water fluxes in continental evapotranspiration suggests that, from the point of view of water resource forecasting, climate model development should prioritize improvements in simulations of biological fluxes rather than physical (evaporation) fluxes.

  5. Snubber reduction

    International Nuclear Information System (INIS)

    Olson, D.E.; Singh, A.K.

    1986-01-01

    Many safety-related piping systems in nuclear power plants have been oversupported. Since snubbers make up a large percentage of the pipe supports or restraints used in a plant, a plant's snubber population is much larger than required to adequately restrain the piping. This has resulted in operating problems and unnecessary expenses for maintenance and inservice inspections (ISIs) of snubbers. This paper presents an overview of snubber reduction, including: the incentives for removing snubbers, a historical perspective on how piping became oversupported, why it is possible to remove snubbers, and the costs and benefits of doing so

  6. NOVANA - National Monitoring and Assessment Programme for the Aquatic and Terrestrial Environment

    DEFF Research Database (Denmark)

    Svendsen, L. M.

    This report is Part 1 of the Programme Description of NOVANA - the Nationwide Monitoring and Assessment Programme for the Aquatic and Terrestrial Environments. Part 1 comprises a general description of the background for the programme, including the international obliga-tions and requirements...... for monitoring of nature and the environment. The overall objective and the scientific and strategic background for the priorities upon which NOVANA pro-gramme is based are described, as are the organization of the programme, the overall economy and the technical assumptions made. Finally the scientific content...

  7. Looking for Cosmic Neutrino Background

    Directory of Open Access Journals (Sweden)

    Chiaki eYanagisawa

    2014-06-01

    Full Text Available Since the discovery of neutrino oscillation in atmospheric neutrinos by the Super-Kamiokande experiment in 1998, study of neutrinos has been one of exciting fields in high-energy physics. All the mixing angles were measured. Quests for 1 measurements of the remaining parameters, the lightest neutrino mass, the CP violating phase(s, and the sign of mass splitting between the mass eigenstates m3 and m1, and 2 better measurements to determine whether the mixing angle theta23 is less than pi/4, are in progress in a well-controlled manner. Determining the nature of neutrinos, whether they are Dirac or Majorana particles is also in progress with continuous improvement. On the other hand, although the ideas of detecting cosmic neutrino background have been discussed since 1960s, there has not been a serious concerted effort to achieve this goal. One of the reasons is that it is extremely difficult to detect such low energy neutrinos from the Big Bang. While there has been tremendous accumulation of information on Cosmic Microwave Background since its discovery in 1965, there is no direct evidence for Cosmic Neutrino Background. The importance of detecting Cosmic Neutrino Background is that, although detailed studies of Big Bang Nucleosynthesis and Cosmic Microwave Background give information of the early Universe at ~a few minutes old and ~300 k years old, respectively, observation of Cosmic Neutrino Background allows us to study the early Universe at $sim$ 1 sec old. This article reviews progress made in the past 50 years on detection methods of Cosmic Neutrino Background.

  8. Climate Impacts on Northern Canada: Regional Background

    Energy Technology Data Exchange (ETDEWEB)

    Prowse, Terry D.; Peters, Daniel L. (Water and Climate Impacts Research Centre, Environment Canada, Dept. of Geography, Univ. of Victoria, Victoria, BC (Canada)). e-mail: terry.prowse@ec.gc.caa; Furgal, Chris (Indigenous Environmental Studies Program, Trent Univ., Peterborough, ON (Canada)); Bonsal, Barrie R. (National Water Research Inst., National Hydrology Research Centre, Environment Canada, Saskatoon, SK (Canada))

    2009-07-15

    Understanding the implications of climate change on northern Canada requires a background about the size and diversity of its human and biogeophysical systems. Occupying an area of almost 40% of Canada, with one-third of this contained in Arctic islands, Canada's northern territories consist of a diversity of physical environments unrivaled around the circumpolar north. Major ecozones composed of a range of landforms, climate, vegetation, and wildlife include: Arctic, boreal and taiga cordillera; boreal and taiga plains; taiga shield; and northern and southern Arctic. Although generally characterized by a cold climate, there is an enormous range in air temperature with mean annual values being as high as -5 deg C in the south to as low as -20 deg C in the high Arctic islands. A similar contrast characterizes precipitation, which can be >700 mm y-1 in some southern alpine regions to as low as 50 mm y-1 over islands of the high Arctic. Major freshwater resources are found within most northern ecozones, varying from large glaciers or ice caps and lakes to extensive wetlands and peat lands. Most of the North's renewable water, however, is found within its major river networks and originates in more southerly headwaters. Ice covers characterize the freshwater systems for multiple months of the year while permafrost prevails in various forms, dominating the terrestrial landscape. The marine environment, which envelops the Canadian Arctic Archipelago, is dominated by seasonal to multiyear sea ice often several meters thick that plays a key role in the regional climate. Almost two-thirds of northern Canadian communities are located along coastlines with the entire population being just over 100 000. Most recent population growth has been dominated by an expansion of nonaboriginals, primarily the result of resource development and the growth of public administration. The economies of northern communities, however, remain quite mixed with traditional land

  9. Natural and man-made terrestrial electromagnetic noise: an outlook

    Directory of Open Access Journals (Sweden)

    A. Meloni

    2007-06-01

    Full Text Available The terrestrial environment is continuously exposed to electromagnetic radiations which set up a «background» electromagnetic noise. Within the Non Ionizing Radiation band (NIR, i.e. for frequencies lower than 300 GHz, this background can have a natural or an artificial origin. Natural origins of electromagnetic radiations are generally atmospheric or cosmic while artificial origins are technological applications, power transmission, communications, etc. This paper briefly describes the natural and man-made electromagnetic noise in the NIR band. Natural noise comes from a large variety of sources involving different physical phenomena and covering a wide range of frequencies and showing various propagation characteristics with an extremely broad range of power levels. Due to technological growth man-made electromagnetic noise is nowadays superimposed on natural noise almost everywhere on Earth. In the last decades man-made noise has increased dramatically over and above the natural noise in residential and business areas. This increase has led some scientists to consider possible negative effects of electromagnetic waves on human life and living systems in general. Accurate measurements of natural and man-made electromagnetic noise are necessary to understand the relative power levels in the different bands and their influence on life.

  10. Terrestrial Biosphere Dynamics in the Climate System: Past and Future

    Science.gov (United States)

    Overpeck, J.; Whitlock, C.; Huntley, B.

    2002-12-01

    The paleoenvironmental record makes it clear that climate change as large as is likely to occur in the next two centuries will drive change in the terrestrial biosphere that is both large and difficult to predict, or plan for. Many species, communities and ecosystems could experience rates of climate change, and "destination climates" that are unprecedented in their time on earth. The paleorecord also makes it clear that a wide range of possible climate system behavior, such as decades-long droughts, increases in large storm and flood frequency, and rapid sea level rise, all occurred repeatedly in the past, and for poorly understood reasons. These types of events, if they were to reoccur in the future, could have especially devastating impacts on biodiversity, both because their timing and spatial extent cannot be anticipated, and because the biota's natural defenses have been compromised by land-use, reductions in genetic flexibility, pollution, excess water utilization, invasive species, and other human influences. Vegetation disturbance (e.g., by disease, pests and fire) will undoubtedly be exacerbated by climate change (stress), but could also speed the rate at which terrestrial biosphere change takes place in the future. The paleoenvironmental record makes it clear that major scientific challenges include an improved ability to model regional biospheric change, both past and future. This in turn will be a prerequisite to obtaining realistic estimates of future biogeochemical and biophysical feedbacks, and thus to obtaining better assessments of future climate change. These steps will help generate the improved understanding of climate variability that is needed to manage global biodiversity. However, the most troubling message from the paleoenvironmental record is that unchecked anthropogenic climate change could make the Earth's 6th major mass extinction unavoidable.

  11. Terrestrial Carbon Cycle Variability [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Dennis Baldocchi

    2016-09-01

    Full Text Available A growing literature is reporting on how the terrestrial carbon cycle is experiencing year-to-year variability because of climate anomalies and trends caused by global change. As CO2 concentration records in the atmosphere exceed 50 years and as satellite records reach over 30 years in length, we are becoming better able to address carbon cycle variability and trends. Here we review how variable the carbon cycle is, how large the trends in its gross and net fluxes are, and how well the signal can be separated from noise. We explore mechanisms that explain year-to-year variability and trends by deconstructing the global carbon budget. The CO2 concentration record is detecting a significant increase in the seasonal amplitude between 1958 and now. Inferential methods provide a variety of explanations for this result, but a conclusive attribution remains elusive. Scientists have reported that this trend is a consequence of the greening of the biosphere, stronger northern latitude photosynthesis, more photosynthesis by semi-arid ecosystems, agriculture and the green revolution, tropical temperature anomalies, or increased winter respiration. At the global scale, variability in the terrestrial carbon cycle can be due to changes in constituent fluxes, gross primary productivity, plant respiration and heterotrophic (microbial respiration, and losses due to fire, land use change, soil erosion, or harvesting. It remains controversial whether or not there is a significant trend in global primary productivity (due to rising CO2, temperature, nitrogen deposition, changing land use, and preponderance of wet and dry regions. The degree to which year-to-year variability in temperature and precipitation anomalies affect global primary productivity also remains uncertain. For perspective, interannual variability in global gross primary productivity is relatively small (on the order of 2 Pg-C y-1 with respect to a large and uncertain background (123 +/- 4 Pg-C y-1

  12. Characterization of neutral lipase BT-1 isolated from the labial gland of Bombus terrestris males.

    Directory of Open Access Journals (Sweden)

    Jana Brabcová

    Full Text Available BACKGROUND: In addition to their general role in the hydrolysis of storage lipids, bumblebee lipases can participate in the biosynthesis of fatty acids that serve as precursors of pheromones used for sexual communication. RESULTS: We studied the temporal dynamics of lipolytic activity in crude extracts from the cephalic part of Bombus terrestris labial glands. Extracts from 3-day-old males displayed the highest lipolytic activity. The highest lipase gene expression level was observed in freshly emerged bumblebees, and both gene expression and lipase activity were lower in bumblebees older than 3 days. Lipase was purified from labial glands, further characterized and named as BT-1. The B. terrestris orthologue shares 88% sequence identity with B. impatiens lipase HA. The molecular weight of B. terrestris lipase BT-1 was approximately 30 kDa, the pH optimum was 8.3, and the temperature optimum was 50°C. Lipase BT-1 showed a notable preference for C8-C10 p-nitrophenyl esters, with the highest activity toward p-nitrophenyl caprylate (C8. The Michaelis constant (Km and maximum reaction rate (Vmax for p-nitrophenyl laurate hydrolysis were Km = 0.0011 mM and Vmax = 0.15 U/mg. CONCLUSION: This is the first report describing neutral lipase from the labial gland of B. terrestris. Our findings help increase understanding of its possible function in the labial gland.

  13. Level of terrestrial gamma radiation and doses to population in Jiangsu province

    International Nuclear Information System (INIS)

    1985-01-01

    In this paper the results of investigation of terrestrial gamma radiation level in Jiangsu Province are reported and the population doses due to this radiation are estimated. The sketch map of the geographical distribution of the terrestrial gamma radiation level is given. In this investigation FD-71 portable scintillation counters and RSS-111 high pressure ionization chambers were used. The results showed that the terrestrial gamma absorbed dose rates in air for indoors and outdoors were 10.7 x 10 -8 Gy/h and 6.5 x 10 -8 Gy/h (weighted values) respectively. The indoors-to-outdoors ratio was 1.65. The total (indoor plus outdoor) annual effective dose equivalent from terrestrial gamma radiation, averaged over the population in this province, was 6.0 x 10 -4 Sv. The collective annual effective dose equivalent was 3.6 x 10 4 man.Sv. Therefore, the absorbed dose to population in Jiangsu Province is in the range of the normal background

  14. Analysis techniques for background rejection at the Majorana Demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Cuestra, Clara [University of Washington; Rielage, Keith Robert [Los Alamos National Laboratory; Elliott, Steven Ray [Los Alamos National Laboratory; Xu, Wenqin [Los Alamos National Laboratory; Goett, John Jerome III [Los Alamos National Laboratory

    2015-06-11

    The MAJORANA Collaboration is constructing the MAJORANA DEMONSTRATOR, an ultra-low background, 40-kg modular HPGe detector array to search for neutrinoless double beta decay in 76Ge. In view of the next generation of tonne-scale Ge-based 0νββ-decay searches that will probe the neutrino mass scale in the inverted-hierarchy region, a major goal of the MAJORANA DEMONSTRATOR is to demonstrate a path forward to achieving a background rate at or below 1 count/tonne/year in the 4 keV region of interest around the Q-value at 2039 keV. The background rejection techniques to be applied to the data include cuts based on data reduction, pulse shape analysis, event coincidences, and time correlations. The Point Contact design of the DEMONSTRATOR's germanium detectors allows for significant reduction of gamma background.

  15. LOFT gamma densitometer background fluxes

    International Nuclear Information System (INIS)

    Grimesey, R.A.; McCracken, R.T.

    1978-01-01

    Background gamma-ray fluxes were calculated at the location of the γ densitometers without integral shielding at both the hot-leg and cold-leg primary piping locations. The principal sources for background radiation at the γ densitometers are 16 N activity from the primary piping H 2 O and γ radiation from reactor internal sources. The background radiation was calculated by the point-kernel codes QAD-BSA and QAD-P5A. Reasonable assumptions were required to convert the response functions calculated by point-kernel procedures into the gamma-ray spectrum from reactor internal sources. A brief summary of point-kernel equations and theory is included

  16. A definition of background independence

    International Nuclear Information System (INIS)

    Gryb, Sean

    2010-01-01

    We propose a definition for background (in)/dependence in dynamical theories of the evolution of configurations that have a continuous symmetry and test this definition on particle models and on gravity. Our definition draws from Barbour's best matching framework developed for the purpose of implementing spatial and temporal relationalism. Among other interesting theories, general relativity can be derived within this framework in novel ways. We study the detailed canonical structure of a wide range of best matching theories and show that their actions must have a local gauge symmetry. When gauge theory is derived in this way, we obtain at the same time a conceptual framework for distinguishing between background-dependent and -independent theories. Gauge invariant observables satisfying Kuchar's criterion are identified and, in simple cases, explicitly computed. We propose a procedure for inserting a global background time into temporally relational theories. Interestingly, using this procedure in general relativity leads to unimodular gravity.

  17. Radon reduction

    International Nuclear Information System (INIS)

    Hamilton, M.A.

    1990-01-01

    During a radon gas screening program, elevated levels of radon gas were detected in homes on Mackinac Island, Mich. Six homes on foundations with crawl spaces were selected for a research project aimed at reducing radon gas concentrations, which ranged from 12.9 to 82.3 pCi/l. Using isolation and ventilation techniques, and variations thereof, radon concentrations were reduced to less than 1 pCi/l. This paper reports that these reductions were achieved using 3.5 mil cross laminated or 10 mil high density polyethylene plastic as a barrier without sealing to the foundation or support piers, solid and/or perforated plastic pipe and mechanical fans. Wind turbines were found to be ineffective at reducing concentrations to acceptable levels. Homeowners themselves installed all materials

  18. Generative electronic background music system

    Energy Technology Data Exchange (ETDEWEB)

    Mazurowski, Lukasz [Faculty of Computer Science, West Pomeranian University of Technology in Szczecin, Zolnierska Street 49, Szczecin, PL (Poland)

    2015-03-10

    In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions.

  19. Background metric in supergravity theories

    International Nuclear Information System (INIS)

    Yoneya, T.

    1978-01-01

    In supergravity theories, we investigate the conformal anomaly of the path-integral determinant and the problem of fermion zero modes in the presence of a nontrivial background metric. Except in SO(3) -invariant supergravity, there are nonvanishing conformal anomalies. As a consequence, amplitudes around the nontrivial background metric contain unpredictable arbitrariness. The fermion zero modes which are explicitly constructed for the Euclidean Schwarzschild metric are interpreted as an indication of the supersymmetric multiplet structure of a black hole. The degree of degeneracy of a black hole is 2/sup 4n/ in SO(n) supergravity

  20. Background music and cognitive performance.

    Science.gov (United States)

    Angel, Leslie A; Polzella, Donald J; Elvers, Greg C

    2010-06-01

    The present experiment employed standardized test batteries to assess the effects of fast-tempo music on cognitive performance among 56 male and female university students. A linguistic processing task and a spatial processing task were selected from the Criterion Task Set developed to assess verbal and nonverbal performance. Ten excerpts from Mozart's music matched for tempo were selected. Background music increased the speed of spatial processing and the accuracy of linguistic processing. The findings suggest that background music can have predictable effects on cognitive performance.

  1. Children of ethnic minority backgrounds

    DEFF Research Database (Denmark)

    Johansen, Stine Liv

    2010-01-01

    media products and toys just as they will have knowledge of different media texts, play genres, rhymes etc. This has consequences for their ability to access social settings, for instance in play. New research in this field will focus on how children themselves make sense of this balancing of cultures......Children of ethnic minority background balance their everyday life between a cultural background rooted in their ethnic origin and a daily life in day care, schools and with peers that is founded in a majority culture. This means, among other things, that they often will have access to different...

  2. Generative electronic background music system

    International Nuclear Information System (INIS)

    Mazurowski, Lukasz

    2015-01-01

    In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions

  3. Low Background Micromegas in CAST

    DEFF Research Database (Denmark)

    Garza, J G; Aune, S.; Aznar, F.

    2014-01-01

    Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micr...

  4. Teaching about Natural Background Radiation

    Science.gov (United States)

    Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

    2013-01-01

    Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also…

  5. Educational Choice. A Background Paper.

    Science.gov (United States)

    Quality Education for Minorities Network, Washington, DC.

    This paper addresses school choice, one proposal to address parental involvement concerns, focusing on historical background, definitions, rationale for advocating choice, implementation strategies, and implications for minorities and low-income families. In the past, transfer payment programs such as tuition tax credits and vouchers were…

  6. Kerr metric in cosmological background

    Energy Technology Data Exchange (ETDEWEB)

    Vaidya, P C [Gujarat Univ., Ahmedabad (India). Dept. of Mathematics

    1977-06-01

    A metric satisfying Einstein's equation is given which in the vicinity of the source reduces to the well-known Kerr metric and which at large distances reduces to the Robertson-Walker metric of a nomogeneous cosmological model. The radius of the event horizon of the Kerr black hole in the cosmological background is found out.

  7. Low Background Micromegas in CAST

    CERN Document Server

    Garza, J.G.; Aznar, F.; Calvet, D.; Castel, J.F.; Christensen, F.E.; Dafni, T.; Davenport, M.; Decker, T.; Ferrer-Ribas, E.; Galán, J.; García, J.A.; Giomataris, I.; Hill, R.M.; Iguaz, F.J.; Irastorza, I.G.; Jakobsen, A.C.; Jourde, D.; Mirallas, H.; Ortega, I.; Papaevangelou, T.; Pivovaroff, M.J.; Ruz, J.; Tomás, A.; Vafeiadis, T.; Vogel, J.K.

    2015-11-16

    Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micromegas detectors for the CERN Axion Solar Telescope (CAST), including technological pathfinder activities for the future International Axion Observatory (IAXO). The use of low background techniques and the application of discrimination algorithms based on the high granularity of the readout have led to background levels below 10$^{-6}$ counts/keV/cm$^2$/s, more than a factor 100 lower than the first generation of Micromegas detectors. The best levels achieved at the Canfranc Underground Laboratory (LSC) are as low as 10$^{-7}$ counts/keV/cm$^2$/s, showing good prospects for the application of this technology in IAXO. The current background model, based on underground and surface measurements, is presented, as well as ...

  8. The Cosmic Infrared Background Experiment

    Science.gov (United States)

    Bock, James; Battle, J.; Cooray, A.; Hristov, V.; Kawada, M.; Keating, B.; Lee, D.; Matsumoto, T.; Matsuura, S.; Nam, U.; Renbarger, T.; Sullivan, I.; Tsumura, K.; Wada, T.; Zemcov, M.

    2009-01-01

    We are developing the Cosmic Infrared Background ExpeRiment (CIBER) to search for signatures of first-light galaxy emission in the extragalactic background. The first generation of stars produce characteristic signatures in the near-infrared extragalactic background, including a redshifted Ly-cutoff feature and a characteristic fluctuation power spectrum, that may be detectable with a specialized instrument. CIBER consists of two wide-field cameras to measure the fluctuation power spectrum, and a low-resolution and a narrow-band spectrometer to measure the absolute background. The cameras will search for fluctuations on angular scales from 7 arcseconds to 2 degrees, where the first-light galaxy spatial power spectrum peaks. The cameras have the necessary combination of sensitivity, wide field of view, spatial resolution, and multiple bands to make a definitive measurement. CIBER will determine if the fluctuations reported by Spitzer arise from first-light galaxies. The cameras observe in a single wide field of view, eliminating systematic errors associated with mosaicing. Two bands are chosen to maximize the first-light signal contrast, at 1.6 um near the expected spectral maximum, and at 1.0 um; the combination is a powerful discriminant against fluctuations arising from local sources. We will observe regions of the sky surveyed by Spitzer and Akari. The low-resolution spectrometer will search for the redshifted Lyman cutoff feature in the 0.7 - 1.8 um spectral region. The narrow-band spectrometer will measure the absolute Zodiacal brightness using the scattered 854.2 nm Ca II Fraunhofer line. The spectrometers will test if reports of a diffuse extragalactic background in the 1 - 2 um band continues into the optical, or is caused by an under estimation of the Zodiacal foreground. We report performance of the assembled and tested instrument as we prepare for a first sounding rocket flight in early 2009. CIBER is funded by the NASA/APRA sub-orbital program.

  9. Graded geometry and Poisson reduction

    OpenAIRE

    Cattaneo, A S; Zambon, M

    2009-01-01

    The main result of [2] extends the Marsden-Ratiu reduction theorem [4] in Poisson geometry, and is proven by means of graded geometry. In this note we provide the background material about graded geometry necessary for the proof in [2]. Further, we provide an alternative algebraic proof for the main result. ©2009 American Institute of Physics

  10. Terrestrial Planet Formation from an Annulus -- Revisited

    Science.gov (United States)

    Deienno, Rogerio; Walsh, Kevin J.; Kretke, Katherine A.; Levison, Harold F.

    2018-04-01

    Numerous recent theories of terrestrial planet formation suggest that, in order to reproduce the observed large Earth to Mars mass ratio, planets formed from an annulus of material within 1 au. The success of these models typically rely on a Mars sized embryo being scattered outside 1 au (to ~1.5 au) and starving, while those remaining inside 1 au continue growing, forming Earth and Venus. In some models the scattering is instigated by the migration of giant planets, while in others an embryo-instability naturally occurs due to the dissipation of the gaseous solar nebula. While these models can typically succeed in reproducing the overall mass ratio among the planets, the final angular momentum deficit (AMD) of the present terrestrial planets in our Solar System, and their radial mass concentration (RMC), namely the position where Mars end up in the simulations, are not always well reproduced. Assuming that the gas nebula may not be entirely dissipated when such an embryo-instability happens, here, we study the effects that the time of such an instability can have on the final AMD and RMC. In addition, we also included energy dissipation within embryo-embryo collisions by assuming a given coefficient of restitution for collisions. Our results show that: i) dissipation within embryo-embryo collisions do not play any important role in the final terrestrial planetary system; ii) the final AMD decreases only when the number of final planets formed increases; iii) the RMC tends to always be lower than the present value no matter the number of final planets; and iv) depending on the time that the embryo-instability happen, if too early, with too much gas still present, a second instability will generally happen after the dissipation of the gas nebula.

  11. 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.

  12. Halogens in chondritic meteorites and terrestrial accretion

    Science.gov (United States)

    Clay, Patricia L.; Burgess, Ray; Busemann, Henner; Ruzié-Hamilton, Lorraine; Joachim, Bastian; Day, James M. D.; Ballentine, Christopher J.

    2017-11-01

    Volatile element delivery and retention played a fundamental part in Earth’s formation and subsequent chemical differentiation. The heavy halogens—chlorine (Cl), bromine (Br) and iodine (I)—are key tracers of accretionary processes owing to their high volatility and incompatibility, but have low abundances in most geological and planetary materials. However, noble gas proxy isotopes produced during neutron irradiation provide a high-sensitivity tool for the determination of heavy halogen abundances. Using such isotopes, here we show that Cl, Br and I abundances in carbonaceous, enstatite, Rumuruti and primitive ordinary chondrites are about 6 times, 9 times and 15-37 times lower, respectively, than previously reported and usually accepted estimates. This is independent of the oxidation state or petrological type of the chondrites. The ratios Br/Cl and I/Cl in all studied chondrites show a limited range, indistinguishable from bulk silicate Earth estimates. Our results demonstrate that the halogen depletion of bulk silicate Earth relative to primitive meteorites is consistent with the depletion of lithophile elements of similar volatility. These results for carbonaceous chondrites reveal that late accretion, constrained to a maximum of 0.5 ± 0.2 per cent of Earth’s silicate mass, cannot solely account for present-day terrestrial halogen inventories. It is estimated that 80-90 per cent of heavy halogens are concentrated in Earth’s surface reservoirs and have not undergone the extreme early loss observed in atmosphere-forming elements. Therefore, in addition to late-stage terrestrial accretion of halogens and mantle degassing, which has removed less than half of Earth’s dissolved mantle gases, the efficient extraction of halogen-rich fluids from the solid Earth during the earliest stages of terrestrial differentiation is also required to explain the presence of these heavy halogens at the surface. The hydropilic nature of halogens, whereby they track

  13. Global analytic treatment of terrestrial photogrammetric networks

    CERN Document Server

    Mayoud, M

    1980-01-01

    In order to solve certain special CERN metrology problems, analytical terrestrial photogrammetry may have some advantages which are first discussed along with their drawbacks and limitations. In this application, it is necessary to carry out a rigorous and global adjustment of the observations and simultaneously process all the perspective ray bundles. The basic principles, the least squares solution and the stochastic analysis of the results are presented. However, for the CERN project, one wonders if the production of digital theodolites is going to reduce the advantages of the photogrammetric method. (12 refs).

  14. Fermi GBM Observations of Terrestrial Gamma Flashes

    Science.gov (United States)

    Wilson-Hodge, Colleen A.; Briggs, M. S.; Connaughton, V.; Fishman, G. J.; Bhat, P. N.; Paciesas, W. S.; Preece, R. D.; Kippen, R. M.; vonKienlin, A.; Dwyer, J. R.; hide

    2010-01-01

    In its first two years of operation, the Fermi Gamma Ray Burst Monitor (GBM) has observed 79 Terrestrial Gamma Flashes (TGFs). The thick Bismuth Germanate (BGO) detectors are excellent for TGF spectroscopy, having a high probability of recording the full energy of an incident photon, spanning a broad energy range from 150 keV to 40 MeV, and recording a large number of photons per TGF. Correlations between GBM TGF triggers and lightning sferics detected with the World-Wide Lightning Location Network indicate that TGFs and lightning are simultaneous to within tens of microseconds.

  15. Terrestrial plant methane production and emission

    DEFF Research Database (Denmark)

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

    2012-01-01

    In this minireview, we evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants and plant. Clearly, despite much uncertainty and skepticism, we conclude that the phenomenon is true. Four stimulating factors have been observed to induce...... aerobic CH4 into a global budget is inadequate. Thus it is too early to draw the line under the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH4 precursors in plant material....

  16. Digital terrestrial television broadcasting technology and system

    CERN Document Server

    2015-01-01

    Now under massive deployment worldwide, digital terrestrial television broadcasting (DTTB) offers one of the most attractive ways to deliver digital TV over the VHF/UHF band. Written by a team of experts for specialists and non-specialists alike, this book serves as a comprehensive guide to DTTB. It covers the fundamentals of channel coding and modulation technologies used in DTTB, as well as receiver technology for synchronization, channel estimation, and equalization. It also covers the recently introduced Chinese DTTB standard, using the SFN network in Hong Kong as an example.

  17. MAFF monitoring of the terrestrial environment

    International Nuclear Information System (INIS)

    Sherlock, J.C.

    1991-01-01

    This paper addresses the MAFF food surveillance programme, in particular our Terrestrial Radioactivity Monitoring Programme (TRAMP), and the estimation of dietary intake of radionuclides. The MAFF programme exists primarily to demonstrate that authorized discharges of radioactivity to the environment do not result in individuals receiving doses of radiation in excess of accepted limits. The estimation radionuclide intake ensures over estimation rather than underestimation of dose. Improvements in detection limits and absorption level research could lower the calculated dose to man from radionuclides in food without losing their validity. (author)

  18. Bryophyte in the Beginning of Terrestrial Life

    Directory of Open Access Journals (Sweden)

    Özcan ŞİMŞEK

    2016-12-01

    Full Text Available The beginning of life has been wondered by human beings since ancient ages. The widely accepted opinion is that life began in water and after that landed. In this process, the landing of plants and adapting to terrestrial life of plants are important stages. The last 20 years it’s been done many researches to find out the relationship of bryophytes and tracheophytes. The results of these researches revealed that in evolutionary development process bryophytes and tracheophytes are sister groups. Thesis about earliest land plants are bryophytes is widely accepted recent years. To understand evolutionary process and plants of today’s better, researches about bryophytes must increase.

  19. Grand scheme for solar-terrestrial research

    International Nuclear Information System (INIS)

    Intriligator, D.S.

    1985-01-01

    The study of solar wind and its interaction with magnetic fields and electrical currents is examined. The effects of magnetic storms caused by solar wind interaction with magnetic fields in the magnetosphere and ionosphere are described. The effect of magnetospheric plasma processes on spacecraft operations and the operation of ground-based systems are explained. The development of an International Solar Terrestrial Physics program, which will be designed to place diagnostic experiments on a collection of spacecraft positioned near space is discussed; the components of the program are described

  20. A New Furostanol Glycoside from Tribulus terrestris

    Directory of Open Access Journals (Sweden)

    Tonghua Liu

    2010-01-01

    Full Text Available Besides two known glycosides, a new furostanol glycoside was isolated from the Fruits of Tribulus terrestris L. The structure of the new furostanol glycoside was established as 26-O-β-D-glucopyranosyl-(25S-5α-furostane-20(22-en-12-one-3β, 26-diol-3-O-α-L-rhamnopyranosyl-(1→2-[β-D-glucopyranosyl-(1→4]-β-D-galactopyranoside (1 on the basis of 1D and 2D-NMR techniques, including COSY, HMBC, and HMQC correlations.

  1. Two new furostanol saponins from Tribulus terrestris.

    Science.gov (United States)

    Xu, Ya-Juan; Xu, Tun-Hai; Zhou, Hai-Ou; Li, Bo; Xie, Sheng-Xu; Si, Yun-Shan; Liu, Yue; Liu, Tong-Hua; Xu, Dong-Ming

    2010-05-01

    Two new furostanol saponins were isolated from the fruits of Tribulus terrestris L. Their structures were established as 26-O-beta-D-glucopyranosyl-(25S)-5alpha-furost-20(22)-en-3beta,26-diol-3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-[beta-D-glucopyranosyl-(1 --> 4)]-beta-D-galactopyranoside (1) and 26-O-beta-D-glucopyranosyl-(25S)-5alpha-furost-20(22)-en-12-one-3beta,26-diol-3-O-beta-D-galactopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 4)-beta-D-galactopyranoside (2) on the basis of spectroscopic data as well as chemical evidence.

  2. A new furostanol glycoside from Tribulus terrestris.

    Science.gov (United States)

    Xu, Yajuan; Liu, Yonghong; Xu, Tunhai; Xie, Shengxu; Si, Yunshan; Liu, Yue; Zhou, Haiou; Liu, Tonghua; Xu, Dongming

    2010-01-27

    Besides two known glycosides, a new furostanol glycoside was isolated from the Fruits of Tribulus terrestris L. The structure of the new furostanol glycoside was established as 26-O-beta-D-glucopyranosyl-(25S)-5alpha-furostane-20(22)-en-12-one-3beta, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->4)]-beta-D-galactopyranoside (1) on the basis of 1D and 2D-NMR techniques, including COSY, HMBC, and HMQC correlations.

  3. Handbook of the Solar-Terrestrial Environment

    CERN Document Server

    Kamide, Y

    2007-01-01

    The Handbook of the Solar-Terrestrial Environment is a unique compendium. Recognized international leaders in their field contribute chapters on basic topics of solar physics, space plasmas and the Earth's magnetosphere, and on applied topics like the aurora, magnetospheric storms, space weather, space climatology and planetary science. This book will be of highest value as a reference for researchers working in the area of planetary and space science. However, it is also written in a style accessible to graduate students majoring in those fields.

  4. Forest-stream linkages: effects of terrestrial invertebrate input and light on diet and growth of brown trout (Salmo trutta in a boreal forest stream.

    Directory of Open Access Journals (Sweden)

    Tibor Erős

    Full Text Available Subsidies of energy and material from the riparian zone have large impacts on recipient stream habitats. Human-induced changes, such as deforestation, may profoundly affect these pathways. However, the strength of individual factors on stream ecosystems is poorly understood since the factors involved often interact in complex ways. We isolated two of these factors, manipulating the flux of terrestrial input and the intensity of light in a 2×2 factorial design, where we followed the growth and diet of two size-classes of brown trout (Salmo trutta and the development of periphyton, grazer macroinvertebrates, terrestrial invertebrate inputs, and drift in twelve 20 m long enclosed stream reaches in a five-month-long experiment in a boreal coniferous forest stream. We found that light intensity, which was artificially increased 2.5 times above ambient levels, had an effect on grazer density, but no detectable effect on chlorophyll a biomass. We also found a seasonal effect on the amount of drift and that the reduction of terrestrial prey input, accomplished by covering enclosures with transparent plastic, had a negative impact on the amount of terrestrial invertebrates in the drift. Further, trout growth was strongly seasonal and followed the same pattern as drift biomass, and the reduction of terrestrial prey input had a negative effect on trout growth. Diet analysis was consistent with growth differences, showing that trout in open enclosures consumed relatively more terrestrial prey in summer than trout living in covered enclosures. We also predicted ontogenetic differences in the diet and growth of old and young trout, where we expected old fish to be more affected by the terrestrial prey reduction, but we found little evidence of ontogenetic differences. Overall, our results showed that reduced terrestrial prey inputs, as would be expected from forest harvesting, shaped differences in the growth and diet of the top predator, brown trout.

  5. Competitiveness of terrestrial greenhouse gas offsets. Are they a bridge to the future?

    International Nuclear Information System (INIS)

    McCarl, B.A.; Sands, R.D.

    2007-01-01

    Activities to reduce net greenhouse gas emissions by biological soil or forest carbon sequestration predominantly utilize currently known, readily implementable technologies. Many other greenhouse gas emission reduction options require future technological development or must wait for turnover of capital stock. Carbon sequestration options in soils and forests, while ready to go now, generally have a finite life, allowing use until other strategies are developed. This paper reports on an investigation of the competitiveness of biological carbon sequestration from a dynamic and multiple strategy viewpoint. Key factors affecting the competitiveness of terrestrial mitigation options are land availability and cost effectiveness relative to other options including CO2 capture and storage, energy efficiency improvements, fuel switching, and non-CO2 greenhouse gas emission reductions. The analysis results show that, at lower CO2 prices and in the near term, soil carbon and other agricultural/forestry options can be important bridges to the future, initially providing a substantial portion of attainable reductions in net greenhouse gas emissions, but with a limited role in later years. At higher CO2 prices, afforestation and biofuels are more dominant among terrestrial options to offset greenhouse gas emissions. But in the longer run, allowing for capital stock turnover, options to reduce greenhouse gas emissions from the energy system and biofuels provide an increasing share of potential reductions in total US greenhouse gas emissions

  6. [Roles of soil dissolved organic carbon in carbon cycling of terrestrial ecosystems: a review].

    Science.gov (United States)

    Li, Ling; Qiu, Shao-Jun; Liu, Jing-Tao; Liu, Qing; Lu, Zhao-Hua

    2012-05-01

    Soil dissolved organic carbon (DOC) is an active fraction of soil organic carbon pool, playing an important role in the carbon cycling of terrestrial ecosystems. In view of the importance of the carbon cycling, this paper summarized the roles of soil DOC in the soil carbon sequestration and greenhouse gases emission, and in considering of our present ecological and environmental problems such as soil acidification and climate warming, discussed the effects of soil properties, environmental factors, and human activities on the soil DOC as well as the response mechanisms of the DOC. This review could be helpful to the further understanding of the importance of soil DOC in the carbon cycling of terrestrial ecosystems and the reduction of greenhouse gases emission.

  7. Background radioactivity in environmental materials

    International Nuclear Information System (INIS)

    Maul, P.R.; O'Hara, J.P.

    1989-01-01

    This paper presents the results of a literature search to identify information on concentrations of 'background' radioactivity in foodstuffs and other commonly available environmental materials. The review has concentrated on naturally occurring radioactivity in foods and on UK data, although results from other countries have also been considered where appropriate. The data are compared with established definitions of a 'radioactive' substance and radionuclides which do not appear to be adequately covered in the literature are noted. (author)

  8. Background paper on aquaculture research

    OpenAIRE

    Wenblad, Axel; Jokumsen, Alfred; Eskelinen, Unto; Torrissen, Ole

    2013-01-01

    The Board of MISTRA established in 2012 a Working Group (WG) on Aquaculture to provide the Board with background information for its upcoming decision on whether the foundation should invest in aquaculture research. The WG included Senior Advisor Axel Wenblad, Sweden (Chairman), Professor Ole Torrissen, Norway, Senior Advisory Scientist Unto Eskelinen, Finland and Senior Advisory Scientist Alfred Jokumsen, Denmark. The WG performed an investigation of the Swedish aquaculture sector including ...

  9. Baseline mercury and zinc concentrations in terrestrial and coastal organisms of Admiralty Bay, Antarctica

    International Nuclear Information System (INIS)

    Rodrigues dos Santos, Isaac; Silva-Filho, Emmanoel Vieira; Schaefer, Carlos; Maria Sella, Silvia; Silva, Carlos A.; Gomes, Vicente; Passos, Maria Jose de A.C.R.; Phan Van Ngan

    2006-01-01

    This paper provides the first quantitative information on mercury in soil, coastal sediment, and in characteristic organisms of terrestrial and shallow coastal marine ecosystems from Admiralty Bay (King George Island, Antarctica). As expected for a remote area, mercury content is low in abiotic components of the ecosystem, and probably similar to natural levels. Mercury also occurs in very low concentrations in the vegetation, invertebrates and fish. These low mercury levels may be due to sulphide formation in reducing sediments of this environment. Higher concentrations of mercury occurred in bird feathers and mammal hair, indicating biomagnification. This was not found for Zinc. These results may be useful as a reference background to detect future inputs of trace elements in this remote area of the earth. Terrestrial vegetation and bird feathers are suggested as target regional biomonitors. - Low levels of mercury and zinc occurred in soil and plant samples from Antarctica, but high levels occurred in birds and mammals

  10. The isotropic radio background revisited

    Energy Technology Data Exchange (ETDEWEB)

    Fornengo, Nicolao; Regis, Marco [Dipartimento di Fisica Teorica, Università di Torino, via P. Giuria 1, I–10125 Torino (Italy); Lineros, Roberto A. [Instituto de Física Corpuscular – CSIC/U. Valencia, Parc Científic, calle Catedrático José Beltrán, 2, E-46980 Paterna (Spain); Taoso, Marco, E-mail: fornengo@to.infn.it, E-mail: rlineros@ific.uv.es, E-mail: regis@to.infn.it, E-mail: taoso@cea.fr [Institut de Physique Théorique, CEA/Saclay, F-91191 Gif-sur-Yvette Cédex (France)

    2014-04-01

    We present an extensive analysis on the determination of the isotropic radio background. We consider six different radio maps, ranging from 22 MHz to 2.3 GHz and covering a large fraction of the sky. The large scale emission is modeled as a linear combination of an isotropic component plus the Galactic synchrotron radiation and thermal bremsstrahlung. Point-like and extended sources are either masked or accounted for by means of a template. We find a robust estimate of the isotropic radio background, with limited scatter among different Galactic models. The level of the isotropic background lies significantly above the contribution obtained by integrating the number counts of observed extragalactic sources. Since the isotropic component dominates at high latitudes, thus making the profile of the total emission flat, a Galactic origin for such excess appears unlikely. We conclude that, unless a systematic offset is present in the maps, and provided that our current understanding of the Galactic synchrotron emission is reasonable, extragalactic sources well below the current experimental threshold seem to account for the majority of the brightness of the extragalactic radio sky.

  11. The isotropic radio background revisited

    International Nuclear Information System (INIS)

    Fornengo, Nicolao; Regis, Marco; Lineros, Roberto A.; Taoso, Marco

    2014-01-01

    We present an extensive analysis on the determination of the isotropic radio background. We consider six different radio maps, ranging from 22 MHz to 2.3 GHz and covering a large fraction of the sky. The large scale emission is modeled as a linear combination of an isotropic component plus the Galactic synchrotron radiation and thermal bremsstrahlung. Point-like and extended sources are either masked or accounted for by means of a template. We find a robust estimate of the isotropic radio background, with limited scatter among different Galactic models. The level of the isotropic background lies significantly above the contribution obtained by integrating the number counts of observed extragalactic sources. Since the isotropic component dominates at high latitudes, thus making the profile of the total emission flat, a Galactic origin for such excess appears unlikely. We conclude that, unless a systematic offset is present in the maps, and provided that our current understanding of the Galactic synchrotron emission is reasonable, extragalactic sources well below the current experimental threshold seem to account for the majority of the brightness of the extragalactic radio sky

  12. Backgrounds and characteristics of arsonists.

    Science.gov (United States)

    Labree, Wim; Nijman, Henk; van Marle, Hjalmar; Rassin, Eric

    2010-01-01

    The aim of this study was to gain more insight in the backgrounds and characteristics of arsonists. For this, the psychiatric, psychological, personal, and criminal backgrounds of all arsonists (n=25), sentenced to forced treatment in the maximum security forensic hospital "De Kijvelanden", were compared to the characteristics of a control group of patients (n=50), incarcerated at the same institution for other severe crimes. Apart from DSM-IV Axis I and Axis II disorders, family backgrounds, level of education, treatment history, intelligence (WAIS scores), and PCL-R scores were included in the comparisons. Furthermore, the apparent motives for the arson offences were explored. It was found that arsonists had more often received psychiatric treatment, prior to committing their index offence, and had a history of severe alcohol abuse more often in comparison to the controls. The arsonists turned out to be less likely to suffer from a major psychotic disorder. Both groups did not differ significantly on the other variables, among which the PCL-R total scores and factor scores. Exploratory analyses however, did suggest that arsonists may differentiate from non-arsonists on three items of the PCL-R, namely impulsivity (higher scores), superficial charm (lower scores), and juvenile delinquency (lower scores). Although the number of arsonists with a major psychotic disorder was relatively low (28%), delusional thinking of some form was judged to play a role in causing arson crimes in about half of the cases (52%).

  13. Terrestrial invertebrates in the Rhynie chert ecosystem.

    Science.gov (United States)

    Dunlop, Jason A; Garwood, Russell J

    2018-02-05

    The Early Devonian Rhynie and Windyfield cherts remain a key locality for understanding early life and ecology on land. They host the oldest unequivocal nematode worm (Nematoda), which may also offer the earliest evidence for herbivory via plant parasitism. The trigonotarbids (Arachnida: Trigonotarbida) preserve the oldest book lungs and were probably predators that practiced liquid feeding. The oldest mites (Arachnida: Acariformes) are represented by taxa which include mycophages and predators on nematodes today. The earliest harvestman (Arachnida: Opiliones) includes the first preserved tracheae, and male and female genitalia. Myriapods are represented by a scutigeromorph centipede (Chilopoda: Scutigeromorpha), probably a cursorial predator on the substrate, and a putative millipede (Diplopoda). The oldest springtails (Hexapoda: Collembola) were probably mycophages, and another hexapod of uncertain affinities preserves a gut infill of phytodebris. The first true insects (Hexapoda: Insecta) are represented by a species known from chewing (non-carnivorous?) mandibles. Coprolites also provide insights into diet, and we challenge previous assumptions that several taxa were spore-feeders. Rhynie appears to preserve a largely intact community of terrestrial animals, although some expected groups are absent. The known fossils are (ecologically) consistent with at least part of the fauna found around modern Icelandic hot springs.This article is part of a discussion meeting issue 'The Rhynie cherts: our earliest terrestrial ecosystem revisited'. © 2017 The Author(s).

  14. Carbon dioxide efficiency of terrestrial enhanced weathering.

    Science.gov (United States)

    Moosdorf, Nils; Renforth, Phil; Hartmann, Jens

    2014-05-06

    Terrestrial enhanced weathering, the spreading of ultramafic silicate rock flour to enhance natural weathering rates, has been suggested as part of a strategy to reduce global atmospheric CO2 levels. We budget potential CO2 sequestration against associated CO2 emissions to assess the net CO2 removal of terrestrial enhanced weathering. We combine global spatial data sets of potential source rocks, transport networks, and application areas with associated CO2 emissions in optimistic and pessimistic scenarios. The results show that the choice of source rocks and material comminution technique dominate the CO2 efficiency of enhanced weathering. CO2 emissions from transport amount to on average 0.5-3% of potentially sequestered CO2. The emissions of material mining and application are negligible. After accounting for all emissions, 0.5-1.0 t CO2 can be sequestered on average per tonne of rock, translating into a unit cost from 1.6 to 9.9 GJ per tonne CO2 sequestered by enhanced weathering. However, to control or reduce atmospheric CO2 concentrations substantially with enhanced weathering would require very large amounts of rock. Before enhanced weathering could be applied on large scales, more research is needed to assess weathering rates, potential side effects, social acceptability, and mechanisms of governance.

  15. Terrestrial Sagnac delay constraining modified gravity models

    Science.gov (United States)

    Karimov, R. Kh.; Izmailov, R. N.; Potapov, A. A.; Nandi, K. K.

    2018-04-01

    Modified gravity theories include f(R)-gravity models that are usually constrained by the cosmological evolutionary scenario. However, it has been recently shown that they can also be constrained by the signatures of accretion disk around constant Ricci curvature Kerr-f(R0) stellar sized black holes. Our aim here is to use another experimental fact, viz., the terrestrial Sagnac delay to constrain the parameters of specific f(R)-gravity prescriptions. We shall assume that a Kerr-f(R0) solution asymptotically describes Earth's weak gravity near its surface. In this spacetime, we shall study oppositely directed light beams from source/observer moving on non-geodesic and geodesic circular trajectories and calculate the time gap, when the beams re-unite. We obtain the exact time gap called Sagnac delay in both cases and expand it to show how the flat space value is corrected by the Ricci curvature, the mass and the spin of the gravitating source. Under the assumption that the magnitude of corrections are of the order of residual uncertainties in the delay measurement, we derive the allowed intervals for Ricci curvature. We conclude that the terrestrial Sagnac delay can be used to constrain the parameters of specific f(R) prescriptions. Despite using the weak field gravity near Earth's surface, it turns out that the model parameter ranges still remain the same as those obtained from the strong field accretion disk phenomenon.

  16. Potential Applications of Gosat Based Carbon Budget Products to Refine Terrestrial Ecosystem Model

    Science.gov (United States)

    Kondo, M.; Ichii, K.

    2011-12-01

    optimization procedure as the point analysis, and found that these spatial data help to improve the model's overall reproducibility. The GOSAT product is expected to have higher accuracy since it uses global CO2 observations. Therefore, with the application of GOSAT data, a better estimation of terrestrial carbon cycle can be achieved with optimization. It is anticipated to carry out more detailed analysis upon the arrival of GOSAT product and to verify the reduction in the uncertainty in the future carbon budget and the climate change with the calibrated models, which is the major contribution can be achieved from GOSAT.

  17. Equilibration of the terrestrial water, nitrogen, and carbon cycles

    OpenAIRE

    Schimel, David S.; Braswell, B. H.; Parton, W. J.

    1997-01-01

    Recent advances in biologically based ecosystem models of the coupled terrestrial, hydrological, carbon, and nutrient cycles have provided new perspectives on the terrestrial biosphere’s behavior globally, over a range of time scales. We used the terrestrial ecosystem model Century to examine relationships between carbon, nitrogen, and water dynamics. The model, run to a quasi-steady-state, shows strong correlations between carbon, water, and nitrogen fluxes that l...

  18. Commercialization of terrestrial applications of aerospace power technology

    International Nuclear Information System (INIS)

    Landsberg, D.R.

    1992-01-01

    The potential for commercialization of terrestrial energy systems based upon aerospace power technology's explored. Threats to the aerospace power technology industry, caused by the end of the cold war and weak world economy are described. There are also new opportunities caused by increasing terrestrial energy needs and world-wide concern for the environment. In this paper, the strengths and weaknesses of the aerospace power industry in commercializing terrestrial energy technologies are reviewed. Finally, actions which will enable the aerospace power technology industry to commercialize products into terrestrial energy markets are described

  19. Estimation of effective dose to public from external exposure to natural background radiation in saudi arabia

    International Nuclear Information System (INIS)

    Khalid, A. A.

    2003-01-01

    The effective dose values in sixteen cities in Saudi Arabia due to external exposure to natural radiation were evaluated. These doses are based on natural background components including external exposure to terrestrial radiation and cosmic rays. The importance of evaluating the effective dose to the public due to external exposure to natural background radiation lies in its epidemiological and dosimetric importance and in forming a basis for the assessment of the level of radioactive contamination or pollution in the environment in the future. The exposure to terrestrial radiation was measured using thermoluminescent dosimeters (TLD). The exposure from cosmic radiation was determined using empirical correlation. The values evaluated for the total annual effective dose in all cities were within the world average values. The highest total annual effective dose measured in Al-Khamis city was 802 μSv/y, as compared to 305 μSv/y in Dammam city, which was considered the lowest value

  20. Potential nephrotoxic effects produced by steroidal saponins from hydro alcoholic extract of Tribulus terrestris in STZ-induced diabetic rats.

    Science.gov (United States)

    Gandhi, Sonia; Srinivasan, B P; Akarte, Atul S

    2013-09-01

    Chronic hyperglycemia leads to the development of microvascular complications like diabetic nephropathy. The present study investigated the potential effects of the hydroalcoholic extract of Tribulus terrestris, a plant of Zygophyllaceae family, on the renal complications in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced by administering STZ (90 mg/kg) to the 2-days old neonates. After 6 weeks of induction, diabetic rats were treated with 50 mg/kg hydroalcoholic extract of T. terrestris for 8 weeks. The anti-hyperglycaemic nature was confirmed by reduction in blood glucose and improvement in insulin levels. Diabetic renal injury associated with decrease in total proteins and albumin levels was observed to be improved by T. terrestris extract. Glomerular filtration rate along with inflammatory and growth factors, adiponectin and erythropoietin were also improved by the treatment, though the findings were not significant. However, the beneficial antidiabetic effects of T. terrestris extract in plasma were not observed in kidney histopathology. This was confirmed by the quantitative estimation of unhydrolyzed fraction of saponins (major component: protodioscin) in plasma and kidney samples of normal and diabetic rats. Hence, it can be concluded that 8 weeks treatment with T. terrestris extract produces potential toxic effects in kidney, which are independent of its anti-diabetic action.

  1. Family Background and Educational Choices

    DEFF Research Database (Denmark)

    McIntosh, James; D. Munk, Martin

    enrollments, especially for females. Not only did the educational opportunities for individuals with disadvantaged backgrounds improve absolutely, but their relative position also improved. A similarly dramatic increase in attendance at university for the period 1985-2005 was found for these cohorts when......We examine the participation in secondary and tertiary education of five cohorts of Danish males and females who were aged twenty starting in 1982 and ending in 2002. We find that the large expansion of secondary education in this period was characterized by a phenomenal increase in gymnasium...

  2. Solar system astrophysics background science and the inner solar system

    CERN Document Server

    Milone, Eugene F

    2014-01-01

    The second edition of Solar System Astrophysics: Background Science and the Inner Solar System provides new insights into the burgeoning field of planetary astronomy. As in the first edition, this volume begins with a rigorous treatment of coordinate frames, basic positional astronomy, and the celestial mechanics of two and restricted three body system problems. Perturbations are treated in the same way, with clear step-by-step derivations. Then the Earth’s gravitational potential field and the Earth-Moon system are discussed, and the exposition turns to radiation properties with a chapter on the Sun. The exposition of the physical properties of the Moon and the terrestrial planets are greatly expanded, with much new information highlighted on the Moon, Mercury, Venus, and Mars. All of the material is presented within a framework of historical importance. This book and its sister volume, Solar System Astrophysics: Planetary Atmospheres and the Outer Solar System, are pedagogically well written, providing cl...

  3. Background radiation map of Thailand

    International Nuclear Information System (INIS)

    Angsuwathana, P.; Chotikanatis, P.

    1997-01-01

    The radioelement concentration in the natural environment as well as the radiation exposure to man in day-to-day life is now the most interesting topic. The natural radiation is frequently referred as a standard for comparing additional sources of man-made radiation such as atomic weapon fallout, nuclear power generation, radioactive waste disposal, etc. The Department of Mineral Resources commenced a five-year project of nationwide airborne geophysical survey by awarding to Kenting Earth Sciences International Limited in 1984. The original purpose of survey was to support mineral exploration and geological mapping. Subsequently, the data quantity has been proved to be suitable for natural radiation information. In 1993 the Department of Mineral Resources, with the assistance of IAEA, published a Background Radiation Map of Thailand at the scale of 1:1,000,000 from the existing airborne radiometric digital data. The production of Background Radiation Map of Thailand is the result of data compilation and correction procedure developed over the Canadian Shield. This end product will be used as a base map in environmental application not only for Thailand but also Southeast Asia region. (author)

  4. [Cosmic Microwave Background (CMB) Anisotropies

    Science.gov (United States)

    Silk, Joseph

    1998-01-01

    One of the main areas of research is the theory of cosmic microwave background (CMB) anisotropies and analysis of CMB data. Using the four year COBE data we were able to improve existing constraints on global shear and vorticity. We found that, in the flat case (which allows for greatest anisotropy), (omega/H)0 less than 10(exp -7), where omega is the vorticity and H is the Hubble constant. This is two orders of magnitude lower than the tightest, previous constraint. We have defined a new set of statistics which quantify the amount of non-Gaussianity in small field cosmic microwave background maps. By looking at the distribution of power around rings in Fourier space, and at the correlations between adjacent rings, one can identify non-Gaussian features which are masked by large scale Gaussian fluctuations. This may be particularly useful for identifying unresolved localized sources and line-like discontinuities. Levin and collaborators devised a method to determine the global geometry of the universe through observations of patterns in the hot and cold spots of the CMB. We have derived properties of the peaks (maxima) of the CMB anisotropies expected in flat and open CDM models. We represent results for angular resolutions ranging from 5 arcmin to 20 arcmin (antenna FWHM), scales that are relevant for the MAP and COBRA/SAMBA space missions and the ground-based interferometer. Results related to galaxy formation and evolution are also discussed.

  5. Optical polarization: background and camouflage

    Science.gov (United States)

    Škerlind, Christina; Hallberg, Tomas; Eriksson, Johan; Kariis, Hans; Bergström, David

    2017-10-01

    Polarimetric imaging sensors in the electro-optical region, already military and commercially available in both the visual and infrared, show enhanced capabilities for advanced target detection and recognition. The capabilities arise due to the ability to discriminate between man-made and natural background surfaces using the polarization information of light. In the development of materials for signature management in the visible and infrared wavelength regions, different criteria need to be met to fulfil the requirements for a good camouflage against modern sensors. In conventional camouflage design, the aimed design of the surface properties of an object is to spectrally match or adapt it to a background and thereby minimizing the contrast given by a specific threat sensor. Examples will be shown from measurements of some relevant materials and how they in different ways affect the polarimetric signature. Dimensioning properties relevant in an optical camouflage from a polarimetric perspective, such as degree of polarization, the viewing or incident angle, and amount of diffuse reflection, mainly in the infrared region, will be discussed.

  6. The Cosmic Microwave Background Anisotropy

    Science.gov (United States)

    Bennett, C. L.

    1994-12-01

    The properties of the cosmic microwave background radiation provide unique constraints on the history and evolution of the universe. The first detection of anisotropy of the microwave radiation was reported by the COBE Team in 1992, based on the first year of flight data. The latest analyses of the first two years of COBE data are reviewed in this talk, including the amplitude of the microwave anisotropy as a function of angular scale and the statistical nature of the fluctuations. The two-year results are generally consistent with the earlier first year results, but the additional data allow for a better determination of the key cosmological parameters. In this talk the COBE results are compared with other observational anisotropy results and directions for future cosmic microwave anisotropy observations will be discussed. The National Aeronautics and Space Administration/Goddard Space Flight Center (NASA/GSFC) is responsible for the design, development, and operation of the Cosmic Background Explorer (COBE). Scientific guidance is provided by the COBE Science Working Group.

  7. Cosmic rays and terrestrial life: A brief review

    Science.gov (United States)

    Atri, Dimitra; Melott, Adrian L.

    2014-01-01

    “The investigation into the possible effects of cosmic rays on living organisms will also offer great interest.” - Victor F. Hess, Nobel Lecture, December 12, 1936 High-energy radiation bursts are commonplace in our Universe. From nearby solar flares to distant gamma ray bursts, a variety of physical processes accelerate charged particles to a wide range of energies, which subsequently reach the Earth. Such particles contribute to a number of physical processes occurring in the Earth system. A large fraction of the energy of charged particles gets deposited in the atmosphere, ionizing it, causing changes in its chemistry and affecting the global electric circuit. Remaining secondary particles contribute to the background dose of cosmic rays on the surface and parts of the subsurface region. Life has evolved over the past ∼3 billion years in presence of this background radiation, which itself has varied considerably during the period [1-3]. As demonstrated by the Miller-Urey experiment, lightning plays a very important role in the formation of complex organic molecules, which are the building blocks of more complex structures forming life. There is growing evidence of increase in the lightning rate with increasing flux of charged particles. Is there a connection between enhanced rate of cosmic rays and the origin of life? Cosmic ray secondaries are also known to damage DNA and cause mutations, leading to cancer and other diseases. It is now possible to compute radiation doses from secondary particles, in particular muons and neutrons. Have the variations in cosmic ray flux affected the evolution of life on earth? We describe the mechanisms of cosmic rays affecting terrestrial life and review the potential implications of the variation of high-energy astrophysical radiation on the history of life on earth.

  8. Solar terrestrial coupling through space plasma processes

    International Nuclear Information System (INIS)

    Birn, J.

    2000-01-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project investigates plasma processes that govern the interaction between the solar wind, charged particles ejected from the sun, and the earth's magnetosphere, the region above the ionosphere governed by the terrestrial magnetic field. Primary regions of interest are the regions where different plasma populations interact with each other. These are regions of particularly dynamic plasma behavior, associated with magnetic flux and energy transfer and dynamic energy release. The investigations concerned charged particle transport and energization, and microscopic and macroscopic instabilities in the magnetosphere and adjacent regions. The approaches combined space data analysis with theory and computer simulations

  9. Actinide elements in aquatic and terrestrial environments

    International Nuclear Information System (INIS)

    Bondietti, E.A.

    1978-01-01

    Progress is reported in terrestrial ecology studies with regard to plutonium in biota from the White Oak Creek forest; comparative distribution of plutonium in two forest ecosystems; an ecosystem model of plutonium dynamics; actinide element metabolism in cotton rats; and crayfish studies. Progress is reported in aquatic studies with regard to transuranics in surface waters, frogs, benthic algae, and invertebrates from pond 3513; and radioecology of transuranic elements in cotton rats bordering waste pond 3513. Progress is also reported in stability of trivalent plutonium in White Oak Lake water; chemistry of plutonium, americium, curium, and uranium in pond water; uranium, thorium, and plutonium in small mammals; and effect of soil pretreatment on the distribution of plutonium

  10. Radio techniques for probing the terrestrial ionosphere.

    Science.gov (United States)

    Hunsucker, R. D.

    The subject of the book is a description of the basic principles of operation, plus the capabilities and limitations of all generic radio techniques employed to investigate the terrestrial ionosphere. The purpose of this book is to present to the reader a balanced treatment of each technique so they can understand how to interpret ionospheric data and decide which techniques are most effective for studying specific phenomena. The first two chapters outline the basic theory underlying the techniques, and each following chapter discusses a separate technique. This monograph is entirely devoted to techniques in aeronomy and space physics. The approach is unique in its presentation of the principles, capabilities and limitations of the most important presently used radio techniques. Typical examples of data are shown for the various techniques, and a brief historical account of the technique development is presented. An extended annotated bibliography of the salient papers in the field is included.

  11. Terrestrial nitrogen cycles: Some unanswered questions

    Science.gov (United States)

    Vitousek, P.

    1984-01-01

    Nitrogen is generally considered to be the element which most often limits the growth of plants in both natural and agricultural ecosystems. It regulates plant growth because photosynthetic rates are strongly dependent on the concentration of nitrogen in leaves, and because relatively large mounts of protein are required for cell division and growth. Yet nitrogen is abundant in the biosphere - the well-mixed pool in the atmosphere is considered inexhaustible compared to biotic demand, and the amount of already fixed organic nitrogen in soils far exceeds annual plant uptake in terrestrial ecosystems. In regions where natural vegetation is not nitrogen limited, continuous cultivation induces nitrogen deficiency. Nitrogen loss from cultivated lands is more rapid than that of other elements, and nitrogen fertilization is generally required to maintain crop yield under any continuous system. The pervasiveness of nitrogen deficiency in many natural and most managed sites is discussed.

  12. Accelerated stress testing of terrestrial solar cells

    Science.gov (United States)

    Lathrop, J. W.; Hawkins, D. C.; Prince, J. L.; Walker, H. A.

    1982-01-01

    The development of an accelerated test schedule for terrestrial solar cells is described. This schedule, based on anticipated failure modes deduced from a consideration of IC failure mechanisms, involves bias-temperature testing, humidity testing (including both 85-85 and pressure cooker stress), and thermal-cycle thermal-shock testing. Results are described for 12 different unencapsulated cell types. Both gradual electrical degradation and sudden catastrophic mechanical change were observed. These effects can be used to discriminate between cell types and technologies relative to their reliability attributes. Consideration is given to identifying laboratory failure modes which might lead to severe degradation in the field through second quadrant operation. Test results indicate that the ability of most cell types to withstand accelerated stress testing depends more on the manufacturer's design, processing, and worksmanship than on the particular metallization system. Preliminary tests comparing accelerated test results on encapsulated and unencapsulated cells are described.

  13. 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...

  14. Radionuclide transport processes in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Whicker, F.W.

    1983-01-01

    Some major principles and the status of knowledge concerning the transport of radionuclides through terrestrial ecosystems are reviewed. Fundamental processes which control the flow of radionuclides between ecosystem components such as air, soil, plants, and animals are described, with emphasis on deposition, resuspension, plant uptake, ingestion, and assimilation. Properties of radionuclides, organisms, and ecosystems are examined in relation to their influence on the accumulation of radioactive materials by plants and animals. The effects of the physicochemical nature of the radionuclide; morphology, physiology, and behavior of the organism; and soil, nutrient, and trophic characteristics of the ecosystem are highlighted. Observations in natural ecosystems on radionuclides such as 137 Cs, 90 Sr, 131 I, 3 H, and 239 Pu are used to illustrate current concepts. An assessment of the degree to which the processes controlling radionuclide behavior are understood and of our ability to simulate and predict such behavior with computerized models is offered. Finally, brief comments are made on research needs

  15. New steroidal glycosides from Tribulus terrestris L.

    Science.gov (United States)

    Chen, Gang; Liu, Tao; Lu, Xuan; Wang, Hai-Feng; Hua, Hui-Ming; Pei, Yue-Hu

    2012-01-01

    Two new steroidal glycosides were isolated from Tribulus terrestris L. Their structures were elucidated as 26-O-β-D-glucopyranosyl-5α-furostan-12-one-20(22)-ene-3β,23,26-triol-3-O-β-D-xylopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 3)]-β-D-glucopyranosyl-(1 → 4)-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-galactopyranoside (1) and 26-O-β-D-glucopyranosyl-5α-furostan-20(22)-ene-3β,23,26-triol-3-O-β-D-xylopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 3)]-β-D-glucopyranosyl-(1 → 4)-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-galactopyranoside (2) by spectroscopic methods including 1D and 2D NMR experiments.

  16. An effective method for terrestrial arthropod euthanasia.

    Science.gov (United States)

    Bennie, Neil A C; Loaring, Christopher D; Bennie, Mikaella M G; Trim, Steven A

    2012-12-15

    As scientific understanding of invertebrate life increases, so does the concern for how to end that life in an effective way that minimises (potential) suffering and is also safe for those carrying out the procedure. There is increasing debate on the most appropriate euthanasia methods for invertebrates as their use in experimental research and zoological institutions grows. Their popularity as pet species has also led to an increase in the need for greater veterinary understanding. Through the use of a local injection of potassium chloride (KCl) initially developed for use in American lobsters, this paper describes a safe and effective method for euthanasia in terrestrial invertebrates. Initial work focused on empirically determining the dose for cockroaches, which was then extrapolated to other arthropod species. For this method of euthanasia, we propose the term 'targeted hyperkalosis' to describe death through terminal depolarisation of the thoracic ganglia as a result of high potassium concentration.

  17. Geology and Habitability of Terrestrial Planets

    CERN Document Server

    Fishbaugh, Kathryn E; Raulin, François; Marais, David J; Korablev, Oleg

    2007-01-01

    Given the fundamental importance of and universal interest in whether extraterrestrial life has developed or could eventually develop in our solar system and beyond, it is vital that an examination of planetary habitability goes beyond simple assumptions such as, "Where there is water, there is life." This book has resulted from a workshop at the International Space Science Institute (ISSI) in Bern, Switzerland (5-9 September 2005) that brought together planetary geologists, geophysicists, atmospheric scientists, and biologists to discuss the multi-faceted problem of how the habitability of a planet co-evolves with the geology of the surface and interior, the atmosphere, and the magnetosphere. Each of the six chapters has been written by authors with a range of expertise so that each chapter is itself multi-disciplinary, comprehensive, and accessible to scientists in all disciplines. These chapters delve into what life needs to exist and ultimately to thrive, the early environments of the young terrestrial pl...

  18. Future hotspots of terrestrial mammal loss

    Science.gov (United States)

    Visconti, Piero; Pressey, Robert L.; Giorgini, Daniele; Maiorano, Luigi; Bakkenes, Michel; Boitani, Luigi; Alkemade, Rob; Falcucci, Alessandra; Chiozza, Federica; Rondinini, Carlo

    2011-01-01

    Current levels of endangerment and historical trends of species and habitats are the main criteria used to direct conservation efforts globally. Estimates of future declines, which might indicate different priorities than past declines, have been limited by the lack of appropriate data and models. Given that much of conservation is about anticipating and responding to future threats, our inability to look forward at a global scale has been a major constraint on effective action. Here, we assess the geography and extent of projected future changes in suitable habitat for terrestrial mammals within their present ranges. We used a global earth-system model, IMAGE, coupled with fine-scale habitat suitability models and parametrized according to four global scenarios of human development. We identified the most affected countries by 2050 for each scenario, assuming that no additional conservation actions other than those described in the scenarios take place. We found that, with some exceptions, most of the countries with the largest predicted losses of suitable habitat for mammals are in Africa and the Americas. African and North American countries were also predicted to host the most species with large proportional global declines. Most of the countries we identified as future hotspots of terrestrial mammal loss have little or no overlap with the present global conservation priorities, thus confirming the need for forward-looking analyses in conservation priority setting. The expected growth in human populations and consumption in hotspots of future mammal loss mean that local conservation actions such as protected areas might not be sufficient to mitigate losses. Other policies, directed towards the root causes of biodiversity loss, are required, both in Africa and other parts of the world. PMID:21844048

  19. Intermittent Astrophysical Radiation Sources and Terrestrial Life

    Science.gov (United States)

    Melott, Adrian

    2013-04-01

    Terrestrial life is exposed to a variety of radiation sources. Astrophysical observations suggest that strong excursions in cosmic ray flux and spectral hardness are expected. Gamma-ray bursts and supernovae are expected to irradiate the atmosphere with keV to GeV photons at irregular intervals. Supernovae will produce large cosmic ray excursions, with time development varying with distance from the event. Large fluxes of keV to MeV protons from the Sun pose a strong threat to electromagnetic technology. The terrestrial record shows cosmogenic isotope excursions which are consistent with major solar proton events, and there are observations of G-stars suggesting that the rate of such events may be much higher than previously assumed. In addition there are unknown and unexplained astronomical transients which may indicate new classes of events. The Sun, supernovae, and gamma-ray bursts are all capable of producing lethal fluences, and some are expected on intervals of 10^8 years or so. The history of life on Earth is filled with mass extinctions at a variety of levels of intensity. Most are not understood. Astrophysical radiation may play a role, particularly from large increases in muon irradiation on the ground, and changes in atmospheric chemistry which deplete ozone, admitting increased solar UVB. UVB is strongly absorbed by DNA and proteins, and breaks the chemical bonds---it is a known carcinogen. High muon fluxes will also be damaging to such molecules, but experiments are needed to pin down the rate. Solar proton events which are not directly dangerous for the biota may nevertheless pose a major threat to modern electromagnetic technology through direct impact on satellites and magnetic induction of large currents in power grids, disabling transformers. We will look at the kind of events that are expected on timescales from human to geological, and their likely consequences.

  20. 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.

  1. The terrestrial record of Late Heavy Bombardment

    Science.gov (United States)

    Lowe, Donald R.; Byerly, Gary R.

    2018-04-01

    Until recently, the known impact record of the early Solar System lay exclusively on the surfaces of the Moon, Mars, and other bodies where it has not been erased by later weathering, erosion, impact gardening, and/or tectonism. Study of the cratered surfaces of these bodies led to the concept of the Late Heavy Bombardment (LHB), an interval from about 4.1 to 3.8 billion years ago (Ga) during which the surfaces of the planets and moons in the inner Solar System were subject to unusually high rates of bombardment followed by a decline to present low impact rates by about 3.5 Ga. Over the past 30 years, however, it has become apparent that there is a terrestrial record of large impacts from at least 3.47 to 3.22 Ga and from 2.63 to 2.49 Ga. The present paper explores the earlier of these impact records, providing details about the nature of the 8 known ejecta layers that constitute the evidence for large terrestrial impacts during the earlier of these intervals, the inferred size of the impactors, and the potential effects of these impacts on crustal development and life. The existence of this record implies that LHB did not end abruptly at 3.8-3.7 Ga but rather that high impact rates, either continuous or as impact clusters, persisted until at least the close of the Archean at 2.5 Ga. It implies that the shift from external, impact-related controls on the long-term development of the surface system on the Earth to more internal, geodynamic controls may have occurred much later in geologic history than has been supposed previously.

  2. Grazing livestock are exposed to terrestrial cyanobacteria.

    Science.gov (United States)

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

    2015-02-25

    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 all samples tested, including 6 plant washings, 1 soil sample and ileal contents from 2 grazing horses. Further work was performed to test the hypothesis that ingestion of cyanotoxins contributes to the pathogenesis of some currently unexplained diseases of grazing horses, including equine grass sickness (EGS), equine motor neuron disease (EMND) and hepatopathy. Phormidium population density was significantly higher on EGS fields than on control fields. The cyanobacterial neurotoxic amino acid 2,4-diaminobutyric acid (DAB) was detected in plant washings from EGS fields, but worst case scenario estimations suggested the dose would be insufficient to cause disease. Neither DAB nor the cyanobacterial neurotoxins β-N-methylamino-L-alanine and N-(2-aminoethyl) glycine were detected in neural tissue from 6 EGS horses, 2 EMND horses and 7 control horses. Phormidium was present in low numbers on plants where horses had unexplained hepatopathy. This study did not yield evidence linking known cyanotoxins with disease in grazing horses. However, further study is warranted to identify and quantify toxins produced by cyanobacteria on livestock fields, and determine whether, under appropriate conditions, known or unknown cyanotoxins contribute to currently unexplained diseases in grazing livestock.

  3. The terrestrial biosphere in the SFR region

    Energy Technology Data Exchange (ETDEWEB)

    Jerling, L; Isaeus, M [Stockholm Univ. (Sweden). Dept. of Botany; Lanneck, J [Stockholm Univ. (Sweden). Dept. of Physical Geography; Lindborg, T; Schueldt, R [Danish Nature Council, Copenhagen (Denmark)

    2001-03-01

    This report is a part of the SKB project 'SAFE' (Safety Assessment of the Final Repository of Radioactive Operational Waste). The aim of project SAFE is to update the previous safety analysis of SFR-1.SFR-1 is a facility for disposal of low and intermediate level radioactive waste, which is situated in bedrock beneath the Baltic Sea, one km off the coast near the Forsmark nuclear power plant in Northern Uppland. A part of the SAFE-analysis aims at analysing the transport of radionuclides in the ecosystems.To do so one has to build a model that includes a large amount of information concerning the biosphere.The first step is to collect and compile descriptions of the biosphere.This report is a first attempt to characterise the terrestrial environment of the SFR area of Forsmark. In the first part of the report the terrestrial environment, land class distribution and production of the area is described. The primary production in different terrestrial ecosystems is estimated for a model area in the Forsmark region. The estimations are based on the actual land class distribution and the values for the total primary production (d.w. above ground biomass)and the amount carbon produced, presented as g/m{sup 2} for each land class respectively. An important aspect of the biosphere is the vegetation and its development. The future development of vegetation is of interest since production,decomposition and thus storage of organic material, vary strongly among vegetation types and this has strong implications for the transport of radionuclides.Therefore an attempt to describe the development of terrestrial vegetation has been made in the second part. Any prediction of future vegetation is based on knowledge of the past together with premises for the future development.The predictions made, thus, becomes marred with errors enforced by the assumptions and incomplete information of the past. The assumptions made for the predictions in this report are crude and results in a

  4. The terrestrial biosphere in the SFR region

    International Nuclear Information System (INIS)

    Jerling, L.; Isaeus, M.

    2001-03-01

    This report is a part of the SKB project 'SAFE' (Safety Assessment of the Final Repository of Radioactive Operational Waste). The aim of project SAFE is to update the previous safety analysis of SFR-1.SFR-1 is a facility for disposal of low and intermediate level radioactive waste, which is situated in bedrock beneath the Baltic Sea, one km off the coast near the Forsmark nuclear power plant in Northern Uppland. A part of the SAFE-analysis aims at analysing the transport of radionuclides in the ecosystems.To do so one has to build a model that includes a large amount of information concerning the biosphere.The first step is to collect and compile descriptions of the biosphere.This report is a first attempt to characterise the terrestrial environment of the SFR area of Forsmark. In the first part of the report the terrestrial environment, land class distribution and production of the area is described. The primary production in different terrestrial ecosystems is estimated for a model area in the Forsmark region. The estimations are based on the actual land class distribution and the values for the total primary production (d.w. above ground biomass)and the amount carbon produced, presented as g/m 2 for each land class respectively. An important aspect of the biosphere is the vegetation and its development. The future development of vegetation is of interest since production,decomposition and thus storage of organic material, vary strongly among vegetation types and this has strong implications for the transport of radionuclides.Therefore an attempt to describe the development of terrestrial vegetation has been made in the second part. Any prediction of future vegetation is based on knowledge of the past together with premises for the future development.The predictions made, thus, becomes marred with errors enforced by the assumptions and incomplete information of the past. The assumptions made for the predictions in this report are crude and results in a coarse

  5. The terrestrial biosphere in the SFR region

    Energy Technology Data Exchange (ETDEWEB)

    Jerling, L.; Isaeus, M. [Stockholm Univ. (Sweden). Dept. of Botany; Lanneck, J. [Stockholm Univ. (Sweden). Dept. of Physical Geography; Lindborg, T.; Schueldt, R. [Danish Nature Council, Copenhagen (Denmark)

    2001-03-01

    This report is a part of the SKB project 'SAFE' (Safety Assessment of the Final Repository of Radioactive Operational Waste). The aim of project SAFE is to update the previous safety analysis of SFR-1.SFR-1 is a facility for disposal of low and intermediate level radioactive waste, which is situated in bedrock beneath the Baltic Sea, one km off the coast near the Forsmark nuclear power plant in Northern Uppland. A part of the SAFE-analysis aims at analysing the transport of radionuclides in the ecosystems.To do so one has to build a model that includes a large amount of information concerning the biosphere.The first step is to collect and compile descriptions of the biosphere.This report is a first attempt to characterise the terrestrial environment of the SFR area of Forsmark. In the first part of the report the terrestrial environment, land class distribution and production of the area is described. The primary production in different terrestrial ecosystems is estimated for a model area in the Forsmark region. The estimations are based on the actual land class distribution and the values for the total primary production (d.w. above ground biomass)and the amount carbon produced, presented as g/m{sup 2} for each land class respectively. An important aspect of the biosphere is the vegetation and its development. The future development of vegetation is of interest since production,decomposition and thus storage of organic material, vary strongly among vegetation types and this has strong implications for the transport of radionuclides.Therefore an attempt to describe the development of terrestrial vegetation has been made in the second part. Any prediction of future vegetation is based on knowledge of the past together with premises for the future development.The predictions made, thus, becomes marred with errors enforced by the assumptions and incomplete information of the past. The assumptions made for the predictions in this report are crude and results

  6. Auditory intensity processing: Effect of MRI background noise.

    Science.gov (United States)

    Angenstein, Nicole; Stadler, Jörg; Brechmann, André

    2016-03-01

    Studies on active auditory intensity discrimination in humans showed equivocal results regarding the lateralization of processing. Whereas experiments with a moderate background found evidence for right lateralized processing of intensity, functional magnetic resonance imaging (fMRI) studies with background scanner noise suggest more left lateralized processing. With the present fMRI study, we compared the task dependent lateralization of intensity processing between a conventional continuous echo planar imaging (EPI) sequence with a loud background scanner noise and a fast low-angle shot (FLASH) sequence with a soft background scanner noise. To determine the lateralization of the processing, we employed the contralateral noise procedure. Linearly frequency modulated (FM) tones were presented monaurally with and without contralateral noise. During both the EPI and the FLASH measurement, the left auditory cortex was more strongly involved than the right auditory cortex while participants categorized the intensity of FM tones. This was shown by a strong effect of the additional contralateral noise on the activity in the left auditory cortex. This means a massive reduction in background scanner noise still leads to a significant left lateralized effect. This suggests that the reversed lateralization in fMRI studies with loud background noise in contrast to studies with softer background cannot be fully explained by the MRI background noise. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Low background aspects of GERDA

    International Nuclear Information System (INIS)

    Simgen, Hardy

    2011-01-01

    The GERDA experiment operates bare Germanium diodes enriched in 76 Ge in an environment of pure liquid argon to search for neutrinoless double beta decay. A very low radioactive background is essential for the success of the experiment. We present here the research done in order to remove radio-impurities coming from the liquid argon, the stainless steel cryostat and the front-end electronics. We found that liquid argon can be purified efficiently from 222 Rn. The main source of 222 Rn in GERDA is the cryostat which emanates about 55 mBq. A thin copper shroud in the center of the cryostat was implemented to prevent radon from approaching the diodes. Gamma ray screening of radio-pure components for front-end electronics resulted in the development of a pre-amplifier with a total activity of less than 1 mBq 228 Th.

  8. The cosmic microwave background radiation

    International Nuclear Information System (INIS)

    Wilson, R.W.

    1980-01-01

    The history is described of the discovery of microwave radiation of the cosmic background using the 20-foot horn antenna at the Bell Laboratories back in 1965. Ruby masers with travelling wave were used, featuring the lowest noise in the world. The measurement proceeded on 7 cm. In measuring microwave radiation from the regions outside the Milky Way continuous noise was discovered whose temperature exceeded the calculated contributions of the individual detection system elements by 3 K. A comparison with the theory showed that relict radiation from the Big Bang period was the source of the noise. The discovery was verified by measurements on the 20.1 cm wavelength and by other authors' measurements on 0.5 mm to 74 cm, and by optical measurements of the interstellar molecule spectrum. (Ha)

  9. Polarization of Cosmic Microwave Background

    International Nuclear Information System (INIS)

    Buzzelli, A; Cabella, P; De Gasperis, G; Vittorio, N

    2016-01-01

    In this work we present an extension of the ROMA map-making code for data analysis of Cosmic Microwave Background polarization, with particular attention given to the inflationary polarization B-modes. The new algorithm takes into account a possible cross- correlated noise component among the different detectors of a CMB experiment. We tested the code on the observational data of the BOOMERanG (2003) experiment and we show that we are provided with a better estimate of the power spectra, in particular the error bars of the BB spectrum are smaller up to 20% for low multipoles. We point out the general validity of the new method. A possible future application is the LSPE balloon experiment, devoted to the observation of polarization at large angular scales. (paper)

  10. 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...

  11. The decadal state of the terrestrial carbon cycle

    NARCIS (Netherlands)

    Velde, van der I.R.; Bloom, J.; Exbrayat, J.; Feng, L.; Williams, M.

    2016-01-01

    The terrestrial carbon cycle is currently the least constrained component of the global carbon budget. Large uncertainties stem from a poor understanding of plant carbon allocation, stocks, residence times, and carbon use efficiency. Imposing observational constraints on the terrestrial carbon cycle

  12. Microplastics as an emerging threat to terrestrial ecosystems.

    Science.gov (United States)

    de Souza Machado, Anderson Abel; Kloas, Werner; Zarfl, Christiane; Hempel, Stefan; Rillig, Matthias C

    2018-04-01

    Microplastics (plastics plastic litter or from direct environmental emission. Their potential impacts in terrestrial ecosystems remain largely unexplored despite numerous reported effects on marine organisms. Most plastics arriving in the oceans were produced, used, and often disposed on land. Hence, it is within terrestrial systems that microplastics might first interact with biota eliciting ecologically relevant impacts. This article introduces the pervasive microplastic contamination as a potential agent of global change in terrestrial systems, highlights the physical and chemical nature of the respective observed effects, and discusses the broad toxicity of nanoplastics derived from plastic breakdown. Making relevant links to the fate of microplastics in aquatic continental systems, we here present new insights into the mechanisms of impacts on terrestrial geochemistry, the biophysical environment, and ecotoxicology. Broad changes in continental environments are possible even in particle-rich habitats such as soils. Furthermore, there is a growing body of evidence indicating that microplastics interact with terrestrial organisms that mediate essential ecosystem services and functions, such as soil dwelling invertebrates, terrestrial fungi, and plant-pollinators. Therefore, research is needed to clarify the terrestrial fate and effects of microplastics. We suggest that due to the widespread presence, environmental persistence, and various interactions with continental biota, microplastic pollution might represent an emerging global change threat to terrestrial ecosystems. © 2017 John Wiley & Sons Ltd.

  13. Climate control of terrestrial carbon exchange across biomes and continents

    Science.gov (United States)

    Chuixiang Yi; Daniel Ricciuto; Runze Li; John Wolbeck; Xiyan Xu; Mats Nilsson; John Frank; William J. Massman

    2010-01-01

    Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2 exchange with the atmosphere across biomes...

  14. Growing technology earthy Tribulus terrestris (Tribulus terrestris L.) and its use

    OpenAIRE

    HUDSKÁ, Miluše

    2015-01-01

    This bachelor thesis deals with Puncturevine (Tribulus terrestris) as for planting, content substances, pharmacological use and with influences of planting technology or elicitors upon the active substance contents. Saponines, flavonoids, and phytosterols are the main active substances of Puncturevine. The saponines act as aphrodisiacs, the flavonoids treat with heart diseases and the phytosterols decrease the cholesterol concentration in blood plasma. The active substance contents depend on ...

  15. Bioassays with terrestrial and aquatic species as monitoring tools of hydrocarbon degradation.

    Science.gov (United States)

    Bori, Jaume; Vallès, Bettina; Ortega, Lina; Riva, Maria Carme

    2016-09-01

    In this study chemical analyses and ecotoxicity tests were applied for the assessment of a heavily hydrocarbon-contaminated soil prior and after the application of a remediation procedure that consisted in the stimulation of soil autochthonous populations of hydrocarbon degraders in static-ventilated biopiles. Terrestrial bioassays were applied in mixtures of test soils and artificial control soil and studied the survival and reproduction of Eisenia fetida and the avoidance response of E. fetida and Folsomia candida. Effects on aquatic organisms were studied by means of acute tests with Vibrio fischeri, Raphidocelis subcapitata, and Daphnia magna performed on aqueous elutriates from test soils. The bioremediation procedure led to a significant reduction in the concentration of hydrocarbons (from 34264 to 3074 mg kg(-1), i.e., 91 % decrease) and toxicity although bioassays were not able to report a percentage decrease of toxicity as high as the percentage reduction. Sublethal tests proved the most sensitive terrestrial bioassays and avoidance tests with earthworms and springtails showed potential as monitoring tools of hydrocarbon remediation due to their high sensitivity and short duration. The concentrations of hydrocarbons in water extracts from test soils were 130 and 100 μg L(-1) before and after remediation, respectively. Similarly to terrestrial tests, most aquatic bioassays detected a significant reduction in toxicity, which was almost negligible at the end of the treatment. D. magna survival was the most affected by soil elutriates although toxicity to the crustacean was associated to the salinity of the samples rather than to the concentration of hydrocarbons. Ecotoxicity tests with aqueous soil elutriates proved less relevant in the assessment of hydrocarbon-contaminated soils due to the low hydrosolubility of hydrocarbons and the influence of the physicochemical parameters of the aquatic medium.

  16. The early evolution of the atmospheres of terrestrial planets

    CERN Document Server

    Raulin, François; Muller, Christian; Nixon, Conor; Astrophysics and Space Science Proceedings : Volume 35

    2013-01-01

    “The Early Evolution of the Atmospheres of Terrestrial Planets” presents the main processes participating in the atmospheric evolution of terrestrial planets. A group of experts in the different fields provide an update of our current knowledge on this topic. Several papers in this book discuss the key role of nitrogen in the atmospheric evolution of terrestrial planets. The earliest setting and evolution of planetary atmospheres of terrestrial planets is directly associated with accretion, chemical differentiation, outgassing, stochastic impacts, and extremely high energy fluxes from their host stars. This book provides an overview of the present knowledge of the initial atmospheric composition of the terrestrial planets. Additionally it includes some papers about the current exoplanet discoveries and provides additional clues to our understanding of Earth’s transition from a hot accretionary phase into a habitable world. All papers included were reviewed by experts in their respective fields. We are ...

  17. Accelerator mass analyses of meteorites - carbon-14 terrestrial ages

    International Nuclear Information System (INIS)

    Miura, Y.; Rucklidge, J.; Beukens, R.; Fireman, E.

    1988-01-01

    Carbon-14 terrestrial ages of ten Antarctic meteorites have been measured by the IsoTrace accelerator mass spectrometry (AMS). The 14 C terrestrial age of 1 gram sample was determined from 14 C concentrations collected at melt and re-melt temperatures, compared with the 14 C concentration of the known Bruderheim chondrite. Yamato-790448 (LL3) chondrite was found to be the oldest terrestrial age of 3x10 4 years in the nine Yamato chondrites, whereas Yamato-791630 (L4) chondrite is considered to be the youngest chondrites less than thousand years. Allan Hills chondrite of ALH-77231 (L6) shows older terrestrial age than the nine Yamato chondrites. New accelerator data of the terrestrial age show higher accuracy with smaller sample than the previous counting method. (author)

  18. 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

  19. 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.

  20. Fungal decomposition of terrestrial organic matter accelerated Early Jurassic climate warming

    Science.gov (United States)

    Pieńkowski, Grzegorz; Hodbod, Marta; Ullmann, Clemens V.

    2016-08-01

    Soils - constituting the largest terrestrial carbon pool - are vulnerable to climatic warming. Currently existing uncertainties regarding carbon fluxes within terrestrial systems can be addressed by studies of past carbon cycle dynamics and related climate change recorded in sedimentary successions. Here we show an example from the Early Jurassic (early Toarcian, c. 183 mya) marginal-marine strata from Poland, tracking the hinterland response to climatic changes through a super-greenhouse event. In contrast to anoxia-related enhanced carbon storage in coeval open marine environments, Total Organic Carbon (TOC) concentrations in the Polish successions are substantially reduced during this event. Increasing temperature favoured fungal-mediated decomposition of plant litter - specifically of normally resistant woody tissues. The associated injection of oxidized organic matter into the atmosphere corresponds to abrupt changes in standing vegetation and may have contributed significantly to the amplified greenhouse climate on Earth. The characteristic Toarcian signature of multiple warm pulses coinciding with rapidly decreasing carbon isotope ratios may in part be the result of a radical reduction of the terrestrial carbon pool as a response to climate change.

  1. Solar radiation uncorks the lignin bottleneck on plant litter decomposition in terrestrial ecosystems

    Science.gov (United States)

    Austin, A.; Ballare, C. L.; Méndez, M. S.

    2015-12-01

    Plant litter decomposition is an essential process in the first stages of carbon and nutrient turnover in terrestrial ecosystems, and together with soil microbial biomass, provide the principal inputs of carbon for the formation of soil organic matter. Photodegradation, the photochemical mineralization of organic matter, has been recently identified as a mechanism for previously unexplained high rates of litter mass loss in low rainfall ecosystems; however, the generality of this process as a control on carbon cycling in terrestrial ecosystems is not known, and the indirect effects of photodegradation on biotic stimulation of carbon turnover have been debated in recent studies. We demonstrate that in a wide range of plant species, previous exposure to solar radiation, and visible light in particular, enhanced subsequent biotic degradation of leaf litter. Moreover, we demonstrate that the mechanism for this enhancement involves increased accessibility for microbial enzymes to plant litter carbohydrates due to a reduction in lignin content. Photodegradation of plant litter reduces the structural and chemical bottleneck imposed by lignin in secondary cell walls. In litter from woody plant species, specific interactions with ultraviolet radiation obscured facilitative effects of solar radiation on biotic decomposition. The generalized positive effect of solar radiation exposure on subsequent microbial activity is mediated by increased accessibility to cell wall polysaccharides, which suggests that photodegradation is quantitatively important in determining rates of mass loss, nutrient release and the carbon balance in a broad range of terrestrial ecosystems.

  2. Diversity of introduced terrestrial flatworms in the Iberian Peninsula: a cautionary tale

    Directory of Open Access Journals (Sweden)

    Marta Álvarez-Presas

    2014-06-01

    Full Text Available Many tropical terrestrial planarians (Platyhelminthes, Geoplanidae have been introduced around the globe. One of these species is known to cause significant decline in earthworm populations, resulting in a reduction of ecological functions that earthworms provide. Flatworms, additionally, are a potential risk to other species that have the same dietary needs. Hence, the planarian invasion might cause significant economic losses in agriculture and damage to the ecosystem. In the Iberian Peninsula only Bipalium kewense Moseley, 1878 had been cited till 2007. From that year on, four more species have been cited, and several reports of the presence of these animals in particular gardens have been received. In the present study we have: (1 analyzed the animals sent by non-specialists and also the presence of terrestrial planarians in plant nurseries and garden centers; (2 identified their species through morphological and phylogenetic molecular analyses, including representatives of their areas of origin; (3 revised their dietary sources and (4 used Species Distribution Modeling (SDM for one species to evaluate the risk of its introduction to natural areas. The results have shown the presence of at least ten species of alien terrestrial planarians, from all its phylogenetic range. International plant trade is the source of these animals, and many garden centers are acting as reservoirs. Also, landscape restoration to reintroduce autochthonous plants has facilitated their introduction close to natural forests and agricultural fields. In conclusion, there is a need to take measures on plant trade and to have special care in the treatment of restored habitats.

  3. Background for Terrestrial Antineutrino Investigations: Scientific Basis of Knowledge on the Composition of the Deep Interior of the Earth

    OpenAIRE

    Herndon, J. Marvin

    2004-01-01

    I present from a historical perspective a logical progression of understanding, related to the composition of the deep interior of the Earth, that comes from fundamental discoveries and from discoveries of fundamental quantitative relationships in nature. By following step by step the reasoning from that understanding, one might begin to appreciate what is not yet known that pertains to recent interest in geo-antineutrinos and also what should be investigated to further advance that understan...

  4. Background radioactivity in sediments near Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    McLin, Stephen G.

    2004-01-01

    remained relatively constant since the early 1980s. These results suggest that clay contents in terrestrial sediments are often more important at concentrating background radionuclides than many other environmental factors, including geology, climate and vegetation. Hence, reservoirs and floodplains represent ideal radionuclide sampling locations because fine-grained materials are more easily trapped here. Ultimately, most of these differences still reflect spatial and temporal variability originating from global atmospheric nuclear weapons testing and disintegration of nuclear-powered satellites upon atmospheric reentry

  5. The decadal state of the terrestrial carbon cycle : Global retrievals of terrestrial carbon allocation, pools, and residence times

    NARCIS (Netherlands)

    Bloom, A Anthony; Exbrayat, Jean-François; van der Velde, Ivar R; Feng, Liang; Williams, Mathew

    2016-01-01

    The terrestrial carbon cycle is currently the least constrained component of the global carbon budget. Large uncertainties stem from a poor understanding of plant carbon allocation, stocks, residence times, and carbon use efficiency. Imposing observational constraints on the terrestrial carbon cycle

  6. Estimating Exposure of Terrestrial Wildlife to Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Sample, B.E.

    1994-01-01

    This report presents a general model for exposure of terrestrial wildlife to contaminants (Sect. 2), methods for estimating parameters of the model (Sect. 3), species specific parameters for endpoint species on the Oak Ridge Reservation (ORR) (Sect. 4), and a sample application (Sect. 5). Exposure can be defined as the coincidence in both space and time of a receptor and a stressor, such that the receptor and stressor come into contact and interact (Risk Assessment Forum 1992). In the context of ecological risk assessment, receptors include all endpoint species or communities identified for a site [see Suter (1989) and Suter et al. (1994) for discussions of ecological endpoints for waste sites]. In the context of waste site assessments, stressors are chemical contaminations, and the contact and interaction are uptake of the contaminant by the receptor. Without sufficient exposure of the receptor to the contaminants, there is no ecological risk. Unlike some other endpoint assemblages, terrestrial wildlife are significantly exposed to contaminants in multiple media. They may drink or swim in contaminated water, ingest contaminated food and soil, and breath contaminated air. In addition, because most wildlife are mobile, moving among and within habitats, exposure is not restricted to a single location. They may integrate contamination from several spatially discrete sources. Therefore, exposure models for terrestrial wildlife must include multiple media. This document provides models and parameters for estimating exposure of birds and mammals. Reptiles and amphibians are not considered because few data exist with which to assess exposure to these organisms. In addition, because toxicological data are scarce for both classes, evaluation of the significance of exposure estimates is problematic. However, the general exposure estimation procedure developed herein for birds and mammals is applicable to reptiles and amphibians. Exposure models must be appropriate to the

  7. Plenoptic background oriented schlieren imaging

    International Nuclear Information System (INIS)

    Klemkowsky, Jenna N; Fahringer, Timothy W; Clifford, Christopher J; Thurow, Brian S; Bathel, Brett F

    2017-01-01

    The combination of the background oriented schlieren (BOS) technique with the unique imaging capabilities of a plenoptic camera, termed plenoptic BOS, is introduced as a new addition to the family of schlieren techniques. Compared to conventional single camera BOS, plenoptic BOS is capable of sampling multiple lines-of-sight simultaneously. Displacements from each line-of-sight are collectively used to build a four-dimensional displacement field, which is a vector function structured similarly to the original light field captured in a raw plenoptic image. The displacement field is used to render focused BOS images, which qualitatively are narrow depth of field slices of the density gradient field. Unlike focused schlieren methods that require manually changing the focal plane during data collection, plenoptic BOS synthetically changes the focal plane position during post-processing, such that all focal planes are captured in a single snapshot. Through two different experiments, this work demonstrates that plenoptic BOS is capable of isolating narrow depth of field features, qualitatively inferring depth, and quantitatively estimating the location of disturbances in 3D space. Such results motivate future work to transition this single-camera technique towards quantitative reconstructions of 3D density fields. (paper)

  8. Concerning background from calorimeter ports

    International Nuclear Information System (INIS)

    Digiacomo, N.J.

    1985-01-01

    Any detector system viewing a port or slit in a calorimeter wall will see, in addition to the primary particles of interest, a background of charged and neutral particles and photons generated by scattering from the port walls and by leakage from incompletely contained primary particle showers in the calorimeter near the port. The signal to noise ratio attainable outside the port is a complex function of the primary source spectrum, the calorimeter and port design and, of course, the nature and acceptance of the detector system that views the port. Rather than making general statements about the overall suitability (or lack thereof) of calorimeter ports, we offer here a specific example based on the external spectrometer and slit of the NA34 experiment. This combination of slit and spectrometer is designed for fixed-target work, so that the primary particle momentum spectrum contains higher momentum particles than expected in a heavy ion colliding beam environment. The results are, nevertheless, quite relevant for the collider case

  9. Natural background radiation in Jordan

    International Nuclear Information System (INIS)

    Daoud, M.N.S.

    1997-01-01

    An Airborne Gamma Ray survey has been accomplished for Jordan since 1979. A complete report has been submitted to the Natural Resources Authority along with field and processed data ''digital and analogue''. Natural radioelements concentration is not provided with this report. From the corrected count rate data for each natural radioelement, Concentrations and exposure rates at the ground level were calculated. Contoured maps, showing the exposure rates and the dose rates were created. Both maps reflect the surface geology of Jordan, where the Phosphate areas are very well delineated by high-level contours. In southeastern Jordan the Ordovician sandstone, which contain high percentage of Th (around 2000 ppm in some places) and a moderate percentage of U (about 300 ppm), also show high gamma radiation exposures compared with the surrounding areas. Comparing the values of the exposure rates given in (μR/h) to those obtained from other countries such as United States, Canada, Germany, etc. Jordan shows higher background radiation which reach two folds and even more than those in these countries. More detailed studies should be performed in order to evaluate the radiological risk limits on people who are living in areas of high radiation such that the area of the phosphatic belt which covers a vast area of Jordan high Plateau. (author)

  10. Natural background radiation in Jordan

    Energy Technology Data Exchange (ETDEWEB)

    Daoud, M N.S. [National Resources Authority, Ministry of Energy and Mineral Resources, Amman (Jordan)

    1997-11-01

    An Airborne Gamma Ray survey has been accomplished for Jordan since 1979. A complete report has been submitted to the Natural Resources Authority along with field and processed data ``digital and analogue``. Natural radioelements concentration is not provided with this report. From the corrected count rate data for each natural radioelement, Concentrations and exposure rates at the ground level were calculated. Contoured maps, showing the exposure rates and the dose rates were created. Both maps reflect the surface geology of Jordan, where the Phosphate areas are very well delineated by high-level contours. In southeastern Jordan the Ordovician sandstone, which contain high percentage of Th (around 2000 ppm in some places) and a moderate percentage of U (about 300 ppm), also show high gamma radiation exposures compared with the surrounding areas. Comparing the values of the exposure rates given in ({mu}R/h) to those obtained from other countries such as United States, Canada, Germany, etc. Jordan shows higher background radiation which reach two folds and even more than those in these countries. More detailed studies should be performed in order to evaluate the radiological risk limits on people who are living in areas of high radiation such that the area of the phosphatic belt which covers a vast area of Jordan high Plateau. (author). 8 refs, 10 figs, 7 tabs.

  11. Extreme precipitation patterns and reductions of terrestrial ecosystem production across biomes

    Science.gov (United States)

    Yongguang Zhang; M. Susan Moran; Mark A. Nearing; Guillermo E. Ponce Campos; Alfredo R. Huete; Anthony R. Buda; David D. Bosch; Stacey A. Gunter; Stanley G. Kitchen; W. Henry McNab; Jack A. Morgan; Mitchel P. McClaran; Diane S. Montoya; Debra P.C. Peters; Patrick J. Starks

    2013-01-01

    Precipitation regimes are predicted to shift to more extreme patterns that are characterized by more heavy rainfall events and longer dry intervals, yet their ecological impacts on vegetation production remain uncertain across biomes in natural climatic conditions. This in situ study investigated the effects of these climatic conditions on aboveground net primary...

  12. Precipitation-Static-Reduction Research

    Science.gov (United States)

    1943-03-31

    if» 85 z \\ PRECIPITATION-STATIC-REDUCTION RESEARCH study of the effects of flame length , flame spacing, and burner spacing on B shows that there...unod: Flame length *. The visual length of the flame from the burner tip to the flame tip when examined in a darkened room against a black background...Postlve and Negative Flames The use of the second flame-conduction coefficient, B, facilitates considerably the study of the effect of flame length , spacing

  13. Reducing DRIFT backgrounds with a submicron aluminized-mylar cathode

    Science.gov (United States)

    Battat, J. B. R.; Daw, E.; Dorofeev, A.; Ezeribe, A. C.; Fox, J. R.; Gauvreau, J.-L.; Gold, M.; Harmon, L.; Harton, J.; Lafler, R.; Landers, J.; Lauer, R. J.; Lee, E. R.; Loomba, D.; Lumnah, A.; Matthews, J.; Miller, E. H.; Mouton, F.; Murphy, A. St. J.; Paling, S. M.; Phan, N.; Sadler, S. W.; Scarff, A.; Schuckman, F. G.; Snowden-Ifft, D.; Spooner, N. J. C.; Walker, D.

    2015-09-01

    Background events in the DRIFT-IId dark matter detector, mimicking potential WIMP signals, are predominantly caused by alpha decays on the central cathode in which the alpha particle is completely or partially absorbed by the cathode material. We installed a 0.9 μm thick aluminized-mylar cathode as a way to reduce the probability of producing these backgrounds. We study three generations of cathode (wire, thin-film, and radiologically clean thin-film) with a focus on the ratio of background events to alpha decays. Two independent methods of measuring the absolute alpha decay rate are used to ensure an accurate result, and agree to within 10%. Using alpha range spectroscopy, we measure the radiologically cleanest cathode version to have a contamination of 3.3±0.1 ppt 234U and 73±2 ppb 238U. This cathode reduces the probability of producing an RPR from an alpha decay by a factor of 70±20 compared to the original stainless steel wire cathode. First results are presented from a texturized version of the cathode, intended to be even more transparent to alpha particles. These efforts, along with other background reduction measures, have resulted in a drop in the observed background rate from 500/day to 1/day. With the recent implementation of full-volume fiducialization, these remaining background events are identified, allowing for background-free operation.

  14. The Global Influence of Cloud Optical Thickness on Terrestrial Carbon Uptake

    Science.gov (United States)

    Zhu, P.; Cheng, S. J.; Keppel-Aleks, G.; Butterfield, Z.; Steiner, A. L.

    2016-12-01

    Clouds play a critical role in regulating Earth's climate. One important way is by changing the type and intensity of solar radiation reaching the Earth's surface, which impacts plant photosynthesis. Specifically, the presence of clouds modifies photosynthesis rates by influencing the amount of diffuse radiation as well as the spectral distribution of solar radiation. Satellite-derived cloud optical thickness (COT) may provide the observational constraint necessary to assess the role of clouds on ecosystems and terrestrial carbon uptake across the globe. Previous studies using ground-based observations at individual sites suggest that below a COT of 7, there is a greater increase in light use efficiency than at higher COT values, providing evidence for higher carbon uptake rates than expected given the reduction in radiation by clouds. However, the strength of the COT-terrestrial carbon uptake correlation across the globe remains unknown. In this study, we investigate the influence of COT on terrestrial carbon uptake on a global scale, which may provide insights into cloud conditions favorable for plant photosynthesis and improve our estimates of the land carbon sink. Global satellite-derived MODIS data show that tropical and subtropical regions tend to have COT values around or below the threshold during growing seasons. We find weak correlations between COT and GPP with Fluxnet MTE global GPP data, which may be due to the uncertainty of upscaling GPP from individual site measurements. Analysis with solar-induced fluorescence (SIF) as a proxy for GPP is also evaluated. Overall, this work constructs a global picture of the role of COT on terrestrial carbon uptake, including its temporal and spatial variations.

  15. A survey of natural terrestrial and airborne radionuclides in moss samples from the peninsular Thailand.

    Science.gov (United States)

    Wattanavatee, Komrit; Krmar, Miodrag; Bhongsuwan, Tripob

    2017-10-01

    The aim of this study was to determine the activity concentrations of natural terrestrial radionuclides ( 238 U, 226 Ra, 232 Th and 40 K) and airborne radionuclides ( 210 Pb, 210 Pb ex and 7 Be) in natural terrestrial mosses. The collected moss samples (46) representing 17 species were collected from 17 sampling localities in the National Parks and Wildlife Sanctuaries of Thailand, situated in the mountainous areas between the northern and the southern ends of peninsular Thailand (∼7-12 °N, 99-102 °E). Activity concentrations of radionuclides in the samples were measured using a low background gamma spectrometer. The results revealed non-uniform spatial distributions of all the radionuclides in the study area. Principal component analysis and cluster analysis revealed two distinct origins for the studied radionuclides, and furthermore, the Pearson correlations were strong within 226 Ra, 232 Th, 238 U and 40 K as well as within 210 Pb and 210 Pb ex , but there was no significant correlation between these two groups. Also 7 Be was uncorrelated to the others, as expected due to different origins of the airborne and terrestrial radionuclides. The radionuclide activities of moss samples varied by moss species, topography, geology, and meteorology of each sampling area. The observed abnormally high concentrations of some radionuclides probably indicate that the concentrations of airborne and terrestrial radionuclides in moss samples were directly related to local geological features of the sampling site, or that high levels of 7 Be were most probably linked with topography and regional NE monsoonal winds from mainland China. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Scientific background of the project

    International Nuclear Information System (INIS)

    Christofidis, I.

    1997-01-01

    The main objective of the proposed project is the development of radioimmunometric assay(s) for the determination of free and total PSA in serum samples from normal and pathological individuals (BPH, PCa). This will be achieved by: A. Selection of appropriate antibody pairs (capture and labelled antibody) for determination of total PSA (free and complex) and for determination of free PSA. From bibliography we have already spotted some antibody pairs. B. Radiolabelling of antibodies. Several labelling and purification procedures will be followed in order to obtain the required analytical sensitivity and dynamic range of the assays. Special attention will be given to the affinity constant as well as to the stability of the radiolabelled molecules. C. Development of protocols for immobilisation of capture antibodies. We will use several solid support formats (plastic tubes, beads and magnetizable particles). Direct adsorption or covalent binding will be used. Immunoadsorption through immobilised second antibody will be also tested in order to decrease the preparation cost of the solid phase reagents. D. Preparation of standards of suitable purity levels. We will test different PSA-free matrices (Bovine serum, buffer solutions etc.) in order to select the most appropriate among them in terms of low background determination and low reagents cost. E. Optimisation of the immunoassays conditions for the free PSA and total PSA (e.g. assay buffers, incubation time, temperature, one or two step procedure, washings). F. Optimisation and standardisation of assay protocols for kit production. G. Production of kits for distribution in clinical laboratories in Greece for comparison with commercial kits. H. Evaluation of the developed assays in real clinical conditions using well characterised human serum samples. This will be performed in co-operation with the Hellenic Society for Tumor Markers, and other anticancer institutions and hospital clinicians of long standing relation

  17. 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).

  18. Terrestrial carbohydrates support freshwater zooplankton during phytoplankton deficiency.

    Science.gov (United States)

    Taipale, Sami J; Galloway, Aaron W E; Aalto, Sanni L; Kahilainen, Kimmo K; Strandberg, Ursula; Kankaala, Paula

    2016-08-11

    Freshwater food webs can be partly supported by terrestrial primary production, often deriving from plant litter of surrounding catchment vegetation. Although consisting mainly of poorly bioavailable lignin, with low protein and lipid content, the carbohydrates from fallen tree leaves and shoreline vegetation may be utilized by aquatic consumers. Here we show that during phytoplankton deficiency, zooplankton (Daphnia magna) can benefit from terrestrial particulate organic matter by using terrestrial-origin carbohydrates for energy and sparing essential fatty acids and amino acids for somatic growth and reproduction. Assimilated terrestrial-origin fatty acids from shoreline reed particles exceeded available diet, indicating that Daphnia may convert a part of their dietary carbohydrates to saturated fatty acids. This conversion was not observed with birch leaf diets, which had lower carbohydrate content. Subsequent analysis of 21 boreal and subarctic lakes showed that diet of herbivorous zooplankton is mainly based on high-quality phytoplankton rich in essential polyunsaturated fatty acids. The proportion of low-quality diets (bacteria and terrestrial particulate organic matter) was <28% of the assimilated carbon. Taken collectively, the incorporation of terrestrial carbon into zooplankton was not directly related to the concentration of terrestrial organic matter in experiments or lakes, but rather to the low availability of phytoplankton.

  19. 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.

  20. Isotope powered Stirling generator for terrestrial applications

    International Nuclear Information System (INIS)

    Tingey, G.L.; Sorensen, G.C.; Ross, B.A.

    1995-01-01

    An electric power supply, small enough to be man-portable, is being developed for remote, terrestrial applications. This system is designed for an operating lifetime of five years without maintenance or refueling. A small Radioisotope Stirling Generator (RSG) has been developed. The energy source of the generator is a 60 watt plutonium-238 fuel clad used in the General Purpose Heat Sources (GPHS) developed for space applications. A free piston Stirling Engine drives a linear alternator to convert the heat to power. The system weighs about 7.5 kg and produces 11 watts AC power with a conversion efficiency of 18.5%. Two engine models have been designed, fabricated, and tested to date: (a) a developmental model instrumented to confirm and test parameters, and (b) an electrically heated model with an electrical heater equipped power input leads. Critical components have been tested for 10,000 to 20,000 hours. One complete generator has been operating for over 11,000 hours. Radioisotope heated prototypes are expected to be fabricated and tested in late 1995

  1. Towards a global terrestrial species monitoring program

    Science.gov (United States)

    Schmeller, Dirk S.; Julliard, Romain; Bellingham, Peter J.; Böhm, Monika; Brummitt, Neil; Chiarucci, Alessandro; Couvet, Denis; Elmendorf, Sarah; Forsyth, David M.; Moreno, Jaime García; Gregory, Richard D.; Magnusson, William E.; Martin, Laura J.; McGeoch, Melodie A.; Mihoub, Jean-Baptiste; Pereira, Henrique M.; Proença, Vânia; van Swaay, Chris A.M.; Yahara, Tetsukazu; Belnap, Jayne

    2015-01-01

    Introduction: The Convention for Biological Diversity’s (CBD) Strategic Plan for Biodiversity 2011-2020 envisions that “By 2050, biodiversity is valued, conserved, restored and wisely used, maintaining ecosystem services, sustaining a healthy planet and delivering benefits essential for all people.” Although 193 parties have adopted these goals, there is little infrastructure in place to monitor global biodiversity trends. Recent international conservation policy requires such data to be up-to-date, reliable, comparable among sites, relevant, and understandable; as is becoming obvious from the work plan adopted by the Intergovernmental Panel for Biodiversity and Ecosystem Services (IPBES: www.ipbes.net/; http://tinyurl.com/ohdnknq). In order to meet the five strategic goals of the Strategic Plan for Biodiversity 2011-2020 and its 20 accompanying Aichi Targets for 2020 (www.cbd.int/sp/targets/), advances need to be made in coordinating large-scale biodiversity monitoring and linking these with environmental data to develop a comprehensive Global Observation Network, as is the main idea behind GEOSS the Global Earth Observation System of Systems (Christian 2005)...Here we identify ten requirements important for the successful implementation of a global biodiversity monitoring network under the flag of GEO BON and especially a global terrestrial species monitoring program.

  2. Pollen and spores of terrestrial plants

    Science.gov (United States)

    Bernhardt, Christopher E.; Willard, Debra A.; Shennan, Ian; Long, Antony J.; Horton, Benjamin P.

    2015-01-01

    Pollen and spores are valuable tools in reconstructing past sea level and climate because of their ubiquity, abundance, and durability as well as their reciprocity with source vegetation to environmental change (Cronin, 1999; Traverse, 2007; Willard and Bernhardt, 2011). Pollan is found in many sedimentary environments, from freshwater to saltwater, terrestrial to marine. It can be abundant in a minimal amount of sample material, for example half a gram, as concentrations can be as high as four million grains per gram (Traverse, 2007). The abundance of pollen in a sample lends it to robust statistical analysis for the quantitative reconstruction of environments. The outer cell wall is resistant to decay in sediments and allows palynomorphs (pollen and spores) to record changes in plant communities and sea level over millions of years. These characteristics make pollen and spores a powerful tool to use in sea-level research.This chapter describes the biology of pollen and spores and how they are transported and preserved in sediments. We present a methodology for isolating pollen from sediments and a general language and framework to identify pollen as well as light micrographs of a selection of common pollen grains, We then discuss their utility in sea-level research.

  3. Mapping and Quantifying Terrestrial Vertebrate Biodiversity at ...

    Science.gov (United States)

    The ability to assess, report, map, and forecast functions of ecosystems is critical to our capacity to make informed decisions to maintain the sustainable nature of our environment. Because of the variability among living organisms and levels of organization (e.g. genetic, species, ecosystem), biodiversity has always been difficult to measure precisely, especially within a systematic manner and over multiple scales. In answer to this challenge, the U.S. Environmental Protection Agency has created a partnership with other Federal agencies, academic institutions, and Non-Governmental Organizations to develop the EnviroAtlas (https://www.epa.gov/enviroatlas), an online national Decision Support Tool that allows users to view and analyze the geographical description of the supply and demand for ecosystem services, as well as the drivers of change. As part of the EnviroAtlas, an approach has been developed that uses deductive habitat models for all terrestrial vertebrates of the conterminous United States and clusters them into biodiversity metrics that relate to ecosystem service-relevant categories. Metrics, such as species and taxon richness, have been developed and integrated with other measures of biodiversity. Collectively, these metrics provide a consistent scalable process from which to make geographic comparisons, provide thematic assessments, and to monitor status and trends in biodiversity. The national biodiversity component operates across approximatel

  4. Crustal development in the terrestrial planets

    Science.gov (United States)

    Taylor, S. R.

    1985-01-01

    The development of planetary crusts may be divided into primary, resulting from melting during accretion, and secondary crusts developed by partial melting from planetary mantles. The Mercurian crust is probably primary with no compelling evidence of later basaltic extrusions. Reflectance spectral evidence for the existence Fe2(+) is equivocal. The Viking Lander XRF data on Mars indicate basaltic material at both sites 4,000 km apart. Surface aeolian processes would be expected to provide a homogeneous average of the crust, but no evidence of more siliceous material is present. This conclusion is weakly supported by the Russian gamma ray data. No evidence for granite appears from the Russian Venera XRF data which indicates MORB-type and alkali basalt (4% K2O) surface compositions. The highlands of Ishtar Terra and Aphrodite probably owe their elevation to tectonic processes rather than compositional effects. Venus may thus resemble the early Archean Earth. The terrestrial granitic continental crust is a product of episodic multiple partial melting events, probably a consequence of the presence of surface water.

  5. The shape of terrestrial abundance distributions

    Science.gov (United States)

    Alroy, John

    2015-01-01

    Ecologists widely accept that the distribution of abundances in most communities is fairly flat but heavily dominated by a few species. The reason for this is that species abundances are thought to follow certain theoretical distributions that predict such a pattern. However, previous studies have focused on either a few theoretical distributions or a few empirical distributions. I illustrate abundance patterns in 1055 samples of trees, bats, small terrestrial mammals, birds, lizards, frogs, ants, dung beetles, butterflies, and odonates. Five existing theoretical distributions make inaccurate predictions about the frequencies of the most common species and of the average species, and most of them fit the overall patterns poorly, according to the maximum likelihood–related Kullback-Leibler divergence statistic. Instead, the data support a low-dominance distribution here called the “double geometric.” Depending on the value of its two governing parameters, it may resemble either the geometric series distribution or the lognormal series distribution. However, unlike any other model, it assumes both that richness is finite and that species compete unequally for resources in a two-dimensional niche landscape, which implies that niche breadths are variable and that trait distributions are neither arrayed along a single dimension nor randomly associated. The hypothesis that niche space is multidimensional helps to explain how numerous species can coexist despite interacting strongly. PMID:26601249

  6. 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.

  7. Dinosaurs and the Cretaceous Terrestrial Revolution

    Science.gov (United States)

    Lloyd, Graeme T; Davis, Katie E; Pisani, Davide; Tarver, James E; Ruta, Marcello; Sakamoto, Manabu; Hone, David W.E; Jennings, Rachel; Benton, Michael J

    2008-01-01

    The observed diversity of dinosaurs reached its highest peak during the mid- and Late Cretaceous, the 50 Myr that preceded their extinction, and yet this explosion of dinosaur diversity may be explained largely by sampling bias. It has long been debated whether dinosaurs were part of the Cretaceous Terrestrial Revolution (KTR), from 125–80 Myr ago, when flowering plants, herbivorous and social insects, squamates, birds and mammals all underwent a rapid expansion. Although an apparent explosion of dinosaur diversity occurred in the mid-Cretaceous, coinciding with the emergence of new groups (e.g. neoceratopsians, ankylosaurid ankylosaurs, hadrosaurids and pachycephalosaurs), results from the first quantitative study of diversification applied to a new supertree of dinosaurs show that this apparent burst in dinosaurian diversity in the last 18 Myr of the Cretaceous is a sampling artefact. Indeed, major diversification shifts occurred largely in the first one-third of the group's history. Despite the appearance of new clades of medium to large herbivores and carnivores later in dinosaur history, these new originations do not correspond to significant diversification shifts. Instead, the overall geometry of the Cretaceous part of the dinosaur tree does not depart from the null hypothesis of an equal rates model of lineage branching. Furthermore, we conclude that dinosaurs did not experience a progressive decline at the end of the Cretaceous, nor was their evolution driven directly by the KTR. PMID:18647715

  8. Energetics of the terrestrial bow shock

    Science.gov (United States)

    Hamrin, Maria; Gunell, Herbert; Norqvist, Patrik

    2017-04-01

    The solar wind is the primary energy source for the magnetospheric energy budget. Energy can enter through the magnetopause both as kinetic energy (plasma entering via e.g. magnetic reconnection and impulsive penetration) and as electromagnetic energy (e.g. by the conversion of solar wind kinetic energy into electromagnetic energy in magnetopause generators). However, energy is extracted from the solar wind already at the bow shock, before it encounters the terrestrial magnetopause. At the bow shock the supersonic solar wind is slowed down and heated, and the region near the bow shock is known to host many complex processes, including the accelerating of particles and the generation of waves. The processes at and near the bow shock can be discussed in terms of energetics: In a generator (load) process kinetic energy is converted to (from) electromagnetic energy. Bow shock regions where the solar wind is decelerated correspond to generators, while regions where particles are energized (accelerated and heated) correspond to loads. Recently, it has been suggested that currents from the bow shock generator should flow across the magnetosheath and connect to the magnetospause current systems [Siebert and Siscoe, 2002; Lopez et al., 2011]. In this study we use data from the Magnetospheric MultiScale (MMS) mission to investigate the energetics of the bow shock and the current closure, and we compare with the MHD simulations of Lopez et al., 2011.

  9. Terrestrial nitrogen-carbon cycle interactions at the global scale.

    Science.gov (United States)

    Zaehle, S

    2013-07-05

    Interactions between the terrestrial nitrogen (N) and carbon (C) cycles shape the response of ecosystems to global change. However, the global distribution of nitrogen availability and its importance in global biogeochemistry and biogeochemical interactions with the climate system remain uncertain. Based on projections of a terrestrial biosphere model scaling ecological understanding of nitrogen-carbon cycle interactions to global scales, anthropogenic nitrogen additions since 1860 are estimated to have enriched the terrestrial biosphere by 1.3 Pg N, supporting the sequestration of 11.2 Pg C. Over the same time period, CO2 fertilization has increased terrestrial carbon storage by 134.0 Pg C, increasing the terrestrial nitrogen stock by 1.2 Pg N. In 2001-2010, terrestrial ecosystems sequestered an estimated total of 27 Tg N yr(-1) (1.9 Pg C yr(-1)), of which 10 Tg N yr(-1) (0.2 Pg C yr(-1)) are due to anthropogenic nitrogen deposition. Nitrogen availability already limits terrestrial carbon sequestration in the boreal and temperate zone, and will constrain future carbon sequestration in response to CO2 fertilization (regionally by up to 70% compared with an estimate without considering nitrogen-carbon interactions). This reduced terrestrial carbon uptake will probably dominate the role of the terrestrial nitrogen cycle in the climate system, as it accelerates the accumulation of anthropogenic CO2 in the atmosphere. However, increases of N2O emissions owing to anthropogenic nitrogen and climate change (at a rate of approx. 0.5 Tg N yr(-1) per 1°C degree climate warming) will add an important long-term climate forcing.

  10. 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....

  11. Transfer coefficients for terrestrial foodchain: their derivation and limitations

    International Nuclear Information System (INIS)

    Ng, Y.C.; Colsher, C.S.; Thompson, S.E.

    1979-01-01

    Transfer coefficients to predict the passage of isotopes from the environment to terrestrial foods have been derived for various radionuclides of importance in the nuclear fuel cycle. These data update and extend previously recommended handbook values. We derive transfer coefficients to terrestrial foods and describe the systematics of the derived transfer coefficients. Suggestions are offered for changes in the values of transfer coefficients to terrestrial foods that now appear in federal regulatory guides. Deficiencies in our present knowledge concerning transfer coefficients and limitations in the use of these values to ensure compliance with radiation protection standards are discussed

  12. Interworking evolution of mobile satellite and terrestrial networks

    Science.gov (United States)

    Matyas, R.; Kelleher, P.; Moller, P.; Jones, T.

    1993-01-01

    There is considerable interest among mobile satellite service providers in interworking with terrestrial networks to provide a universal global network. With such interworking, subscribers may be provided a common set of services such as those planned for the Public Switched Telephone Network (PSTN), the Integrated Services Digital Network (ISDN), and future Intelligent Networks (IN's). This paper first reviews issues in satellite interworking. Next the status and interworking plans of terrestrial mobile communications service providers are examined with early examples of mobile satellite interworking including a discussion of the anticipated evolution towards full interworking between mobile satellite and both fixed and mobile terrestrial networks.

  13. Terrestrial nitrogen cycling in Earth system models revisited

    Science.gov (United States)

    Stocker, Benjamin D; Prentice, I. Colin; Cornell, Sarah; Davies-Barnard, T; Finzi, Adrien; Franklin, Oskar; Janssens, Ivan; Larmola, Tuula; Manzoni, Stefano; Näsholm, Torgny; Raven, John; Rebel, Karin; Reed, Sasha C.; Vicca, Sara; Wiltshire, Andy; Zaehle, Sönke

    2016-01-01

    Understanding the degree to which nitrogen (N) availability limits land carbon (C) uptake under global environmental change represents an unresolved challenge. First-generation ‘C-only’vegetation models, lacking explicit representations of N cycling,projected a substantial and increasing land C sink under rising atmospheric CO2 concentrations. This prediction was questioned for not taking into account the potentially limiting effect of N availability, which is necessary for plant growth (Hungate et al.,2003). More recent global models include coupled C and N cycles in land ecosystems (C–N models) and are widely assumed to be more realistic. However, inclusion of more processes has not consistently improved their performance in capturing observed responses of the global C cycle (e.g. Wenzel et al., 2014). With the advent of a new generation of global models, including coupled C, N, and phosphorus (P) cycling, model complexity is sure to increase; but model reliability may not, unless greater attention is paid to the correspondence of model process representations ande mpirical evidence. It was in this context that the ‘Nitrogen Cycle Workshop’ at Dartington Hall, Devon, UK was held on 1–5 February 2016. Organized by I. Colin Prentice and Benjamin D. Stocker (Imperial College London, UK), the workshop was funded by the European Research Council,project ‘Earth system Model Bias Reduction and assessing Abrupt Climate change’ (EMBRACE). We gathered empirical ecologists and ecosystem modellers to identify key uncertainties in terrestrial C–N cycling, and to discuss processes that are missing or poorly represented in current models.

  14. DETECTING THE SUPERNOVA BREAKOUT BURST IN TERRESTRIAL NEUTRINO DETECTORS

    International Nuclear Information System (INIS)

    Wallace, Joshua; Burrows, Adam; Dolence, Joshua C.

    2016-01-01

    We calculate the distance-dependent performance of a few representative terrestrial neutrino detectors in detecting and measuring the properties of the ν e breakout burst light curve in a Galactic core-collapse supernova. The breakout burst is a signature phenomenon of core collapse and offers a probe into the stellar core through collapse and bounce. We examine cases of no neutrino oscillations and oscillations due to normal and inverted neutrino-mass hierarchies. For the normal hierarchy, other neutrino flavors emitted by the supernova overwhelm the ν e signal, making a detection of the breakout burst difficult. For the inverted hierarchy (IH), some detectors at some distances should be able to see the ν e breakout burst peak and measure its properties. For the IH, the maximum luminosity of the breakout burst can be measured at 10 kpc to accuracies of ∼30% for Hyper-Kamiokande (Hyper-K) and ∼60% for the Deep Underground Neutrino Experiment (DUNE). Super-Kamiokande (Super-K) and Jiangmen Underground Neutrino Observatory (JUNO) lack the mass needed to make an accurate measurement. For the IH, the time of the maximum luminosity of the breakout burst can be measured in Hyper-K to an accuracy of ∼3 ms at 7 kpc, in DUNE to ∼2 ms at 4 kpc, and JUNO and Super-K can measure the time of maximum luminosity to an accuracy of ∼2 ms at 1 kpc. Detector backgrounds in IceCube render a measurement of the ν e breakout burst unlikely. For the IH, a measurement of the maximum luminosity of the breakout burst could be used to differentiate between nuclear equations of state

  15. Analysis of background components in Ge-spectrometry and their influence on detection limits

    Energy Technology Data Exchange (ETDEWEB)

    Heusser, G [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    1997-03-01

    In low radioactivity measurements the system own background of the spectrometer is, besides the counting efficiency, the limiting factor for the achievable sensitivity. Since the latter is mostly fixed, background reduction is the only way to gain sensitivity, although it is inversely proportional only to the square root of the background rate but directly proportional to the counting efficiency. A thorough understanding of the background sources and their quantitative contribution helps to choose the most adequate suppression method in order to reach a certain required level of detection limit. For Ge-spectrometry the background can be reduced by 5 to 6 orders of magnitude compared to the unshielded case applying state-of-the-art techniques. This reduction factor holds for the continuous background spectrum as well as for the line background as demonstrated for a Ge detector of the Heidelberg-Moscow double beta decay experiment. (orig./DG)

  16. Finding optimal exact reducts

    KAUST Repository

    AbouEisha, Hassan M.

    2014-01-01

    The problem of attribute reduction is an important problem related to feature selection and knowledge discovery. The problem of finding reducts with minimum cardinality is NP-hard. This paper suggests a new algorithm for finding exact reducts

  17. Biological control of the terrestrial carbon sink

    Science.gov (United States)

    Schulze, E.-D.

    2006-03-01

    This lecture reviews the past (since 1964 when the International Biological Program began) and the future of our understanding of terrestrial carbon fluxes with focus on photosynthesis, respiration, primary-, ecosystem-, and biome-productivity. Photosynthetic capacity is related to the nitrogen concentration of leaves, but the capacity is only rarely reached under field conditions. Average rates of photosynthesis and stomatal conductance are closely correlated and operate near 50% of their maximal rate, with light being the limiting factor in humid regions and air humidity and soil water the limiting factor in arid climates. Leaf area is the main factor to extrapolate from leaves to canopies, with maximum surface conductance being dependent on leaf level stomatal conductance. Additionally, gas exchange depends also on rooting depth which determines the water and nutrient availability and on mycorrhizae which regulate the nutrient status. An important anthropogenic disturbance is the nitrogen uptake from air pollutants, which is not balanced by cation uptake from roots and this may lead to damage and breakdown of the plant cover. Photosynthesis is the main carbon input into ecosystems, but it alone does not represent the ecosystem carbon balance, which is determined by respiration of various kinds. Plant respiration and photosynthesis determine growth (net primary production) and microbial respiration balances the net ecosystem flux. In a spruce forest, 30% of the assimilatory carbon gain is used for respiration of needles, 20% is used for respiration in stems. Soil respiration is about 50% the carbon gain, half of which is root respiration, half is microbial respiration. In addition, disturbances lead to carbon losses, where fire, harvest and grazing bypass the chain of respiration. In total, the carbon balance at the biome level is only about 1% of the photosynthetic carbon input, or may indeed become negative. The recent observed increase in plant growth has

  18. Biological control of the terrestrial carbon sink

    Directory of Open Access Journals (Sweden)

    E.-D. Schulze

    2006-01-01

    Full Text Available This lecture reviews the past (since 1964 when the International Biological Program began and the future of our understanding of terrestrial carbon fluxes with focus on photosynthesis, respiration, primary-, ecosystem-, and biome-productivity. Photosynthetic capacity is related to the nitrogen concentration of leaves, but the capacity is only rarely reached under field conditions. Average rates of photosynthesis and stomatal conductance are closely correlated and operate near 50% of their maximal rate, with light being the limiting factor in humid regions and air humidity and soil water the limiting factor in arid climates. Leaf area is the main factor to extrapolate from leaves to canopies, with maximum surface conductance being dependent on leaf level stomatal conductance. Additionally, gas exchange depends also on rooting depth which determines the water and nutrient availability and on mycorrhizae which regulate the nutrient status. An important anthropogenic disturbance is the nitrogen uptake from air pollutants, which is not balanced by cation uptake from roots and this may lead to damage and breakdown of the plant cover. Photosynthesis is the main carbon input into ecosystems, but it alone does not represent the ecosystem carbon balance, which is determined by respiration of various kinds. Plant respiration and photosynthesis determine growth (net primary production and microbial respiration balances the net ecosystem flux. In a spruce forest, 30% of the assimilatory carbon gain is used for respiration of needles, 20% is used for respiration in stems. Soil respiration is about 50% the carbon gain, half of which is root respiration, half is microbial respiration. In addition, disturbances lead to carbon losses, where fire, harvest and grazing bypass the chain of respiration. In total, the carbon balance at the biome level is only about 1% of the photosynthetic carbon input, or may indeed become negative. The recent observed increase in

  19. Radiobiological analysis of region with higher radiation background. The effect of the background on the isomorphism of some enzymes

    International Nuclear Information System (INIS)

    Usunov, N.; Dojchinov, A.; Kamenov, D.

    1994-01-01

    An attempt is made to establish the the time when the prolong impact of slightly increased radiation background get over the compensator mechanisms of living systems. The object of investigation was the ecosystem of the Bay of Wromos (Black Sea, BG) and its surroundings where the flotation slack from an uranium mine was disposed. radioactivity. The following radiobiological picture of the site is obtained according to measurements performed: the alpha-activity of the beach sands is higher than one of the slack and is different in plants; the beta-activity is higher compared to controls in all samples investigated; the gamma spectra show high concentration of the members of U-238 and Th-232 series. The biological effect provoked by this heightened radiation background is studied by means of the isoenzymes as indicators of changes on molecular level. The isoenzyme spectra of lactate dehydrogenase and butyrol dehydrogenase is studied by vertical electrophoresis. The following species are tested: Tettigonia candata charp, Galliptumus italicus, Grillus campestris and Lumbicus terrestrial. An increase in activity and quantity of enzymes as well as changes of their isoenzyme spectra is observed. Calliptumus italicus could be used as a bio indicator of contamination, as it show better separation of the LDH and BDH-isoforms of LDH and BDH, and is more wide-spread. The increase in activity and quantity of some isoenzyme fractions in the conditions of this experiment is one of the possible mechanisms for increase in radioresistance of the living systems. 3 tabs., 2 figs., 8 refs

  20. Topographic-driven instabilities in terrestrial bodies

    Science.gov (United States)

    Vantieghem, S.; Cebron, D.; Herreman, W.; Lacaze, L.

    2013-12-01

    Models of internal planetary fluid layers (core flows, subsurface oceans) commonly assume that these fluid envelopes have a spherical shape. This approximation however entails a serious restriction from the fluid dynamics point of view. Indeed, in the presence of mechanical forcings (precession, libration, nutation or tides) due to gravitational interaction with orbiting partners, boundary topography (e.g. of the core-mantle boundary) may excite flow instabilities and space-filling turbulence. These phenomena may affect heat transport and dissipation at the main order. Here, we focus on instabilities driven by longitudinal libration. Using a suite of theoretical tools and numerical simulations, we are able to discern a parameter range for which instability may be excited. We thereby consider deformations of different azimuthal order. This study gives the first numerical evidence of the tripolar instability. Furthermore, we explore the non-linear regime and investigate the amplitude as well as the dissipation of the saturated instability. Indeed, these two quantities control the torques on the solid layers and the thermal transport. Furthermore, based on this results, we address the issue of magnetic field generation associated with these flows (by induction or by dynamo process). This instability mechanism applies to both synchronized as non-synchronized bodies. As such, our results show that a tripolar instability might be present in various terrestrial bodies (Early Moon, Gallilean moons, asteroids, etc.), where it could participate in dynamo action. Simulation of a libration-driven tripolar instability in a deformed spherical fluid layer: snapshot of the velocity magnitude, where a complex 3D flow pattern is established.

  1. Tidal heating in multilayered terrestrial exoplanets

    Energy Technology Data Exchange (ETDEWEB)

    Henning, Wade G.; Hurford, Terry, E-mail: wade.g.henning@nasa.gov [NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States)

    2014-07-01

    The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R{sub E} is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.

  2. Sampling supraglacial debris thickness using terrestrial photogrammetry

    Science.gov (United States)

    Nicholson, Lindsey; Mertes, Jordan

    2017-04-01

    The melt rate of debris-covered ice differs to that of clean ice primarily as a function of debris thickness. The spatial distribution of supraglacial debris thickness must therefore be known in order to understand how it is likely to impact glacier behaviour, and meltwater contribution to local hydrological resources and global sea level rise. However, practical means of determining debris cover thickness remain elusive. In this study we explore the utility of terrestrial photogrammetry to produce high resolution, scaled and texturized digital terrain models of debris cover exposures above ice cliffs as a means of quantifying and characterizing debris thickness. Two Nikon D5000 DSLRs with Tamron 100mm lenses were used to photograph a sample area of the Ngozumpa glacier in the Khumbu Himal of Nepal in April 2016. A Structure from Motion workflow using Agisoft Photoscan software was used to generate a surface models with <10cm resolution. A Trimble Geo7X differential GPS with Zephyr antenna, along with a local base station, was used to precisely measure marked ground control points to scale the photogrammetric surface model. Measurements of debris thickness along the exposed cliffline were made from this scaled model, assuming that the ice surface at the debris-ice boundary is horizontal, and these data are compared to 50 manual point measurements along the same clifftops. We conclude that sufficiently high resolution photogrammetry, with precise scaling information, provides a useful means to determine debris thickness at clifftop exposures. The resolution of the possible measurements depends on image resolution, the accuracy of the ground control points and the computational capacity to generate centimetre scale surface models. Application of such techniques to sufficiently high resolution imagery from UAV-borne cameras may offer a powerful means of determining debris thickness distribution patterns over debris covered glacier termini.

  3. Tidal Heating in Multilayered Terrestrial Exoplanets

    Science.gov (United States)

    Henning, Wade G.; Hurford, Terry

    2014-01-01

    The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R(sub E) is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.

  4. Cause of Cambrian Explosion - Terrestrial or Cosmic?

    Science.gov (United States)

    Steele, Edward J; Al-Mufti, Shirwan; Augustyn, Kenneth A; Chandrajith, Rohana; Coghlan, John P; Coulson, S G; Ghosh, Sudipto; Gillman, Mark; Gorczynski, Reginald M; Klyce, Brig; Louis, Godfrey; Mahanama, Kithsiri; Oliver, Keith R; Padron, Julio; Qu, Jiangwen; Schuster, John A; Smith, W E; Snyder, Duane P; Steele, Julian A; Stewart, Brent J; Temple, Robert; Tokoro, Gensuke; Tout, Christopher A; Unzicker, Alexander; Wainwright, Milton; Wallis, Jamie; Wallis, Daryl H; Wallis, Max K; Wetherall, John; Wickramasinghe, D T; Wickramasinghe, J T; Wickramasinghe, N Chandra; Liu, Yongsheng

    2018-08-01

    We review the salient evidence consistent with or predicted by the Hoyle-Wickramasinghe (H-W) thesis of Cometary (Cosmic) Biology. Much of this physical and biological evidence is multifactorial. One particular focus are the recent studies which date the emergence of the complex retroviruses of vertebrate lines at or just before the Cambrian Explosion of ∼500 Ma. Such viruses are known to be plausibly associated with major evolutionary genomic processes. We believe this coincidence is not fortuitous but is consistent with a key prediction of H-W theory whereby major extinction-diversification evolutionary boundaries coincide with virus-bearing cometary-bolide bombardment events. A second focus is the remarkable evolution of intelligent complexity (Cephalopods) culminating in the emergence of the Octopus. A third focus concerns the micro-organism fossil evidence contained within meteorites as well as the detection in the upper atmosphere of apparent incoming life-bearing particles from space. In our view the totality of the multifactorial data and critical analyses assembled by Fred Hoyle, Chandra Wickramasinghe and their many colleagues since the 1960s leads to a very plausible conclusion - life may have been seeded here on Earth by life-bearing comets as soon as conditions on Earth allowed it to flourish (about or just before 4.1 Billion years ago); and living organisms such as space-resistant and space-hardy bacteria, viruses, more complex eukaryotic cells, fertilised ova and seeds have been continuously delivered ever since to Earth so being one important driver of further terrestrial evolution which has resulted in considerable genetic diversity and which has led to the emergence of mankind. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Tidal heating in multilayered terrestrial exoplanets

    International Nuclear Information System (INIS)

    Henning, Wade G.; Hurford, Terry

    2014-01-01

    The internal pattern and overall magnitude of tidal heating for spin-synchronous terrestrial exoplanets from 1 to 2.5 R E is investigated using a propagator matrix method for a variety of layer structures. Particular attention is paid to ice-silicate hybrid super-Earths, where a significant ice mantle is modeled to rest atop an iron-silicate core, and may or may not contain a liquid water ocean. We find multilayer modeling often increases tidal dissipation relative to a homogeneous model, across multiple orbital periods, due to the ability to include smaller volume low viscosity regions, and the added flexure allowed by liquid layers. Gradations in parameters with depth are explored, such as allowed by the Preliminary Earth Reference Model. For ice-silicate hybrid worlds, dramatically greater dissipation is possible beyond the case of a silicate mantle only, allowing non-negligible tidal activity to extend to greater orbital periods than previously predicted. Surface patterns of tidal heating are found to potentially be useful for distinguishing internal structure. The influence of ice mantle depth and water ocean size and position are shown for a range of forcing frequencies. Rates of orbital circularization are found to be 10-100 times faster than standard predictions for Earth-analog planets when interiors are moderately warmer than the modern Earth, as well as for a diverse range of ice-silicate hybrid super-Earths. Circularization rates are shown to be significantly longer for planets with layers equivalent to an ocean-free modern Earth, as well as for planets with high fractions of either ice or silicate melting.

  6. Terrestrial and aquatic mammals of the Pantanal

    Directory of Open Access Journals (Sweden)

    CJR. Alho

    Full Text Available Different works have registered the number of mammal species within the natural habitats of the Pantanal based on currently known records, with species richness ranging from 89 to 152 of annotated occurrences. Our present list sums 174 species. However, at least three factors have to be emphasised to deal with recorded numbers: 1 to establish the ecotone limit between the floodplain (which is the Pantanal and its neighbouring domain like the Cerrado, besides the existence of maps recently produced; 2 the lack of intensive surveys, especially on small mammals, rodents and marsupials; and 3 the constant taxonomic revision on bats, rodents and marsupials. Some species are very abundant - for example the capybara Hydrochoerus hydrochaeris and the crab-eating fox Cerdocyon thous, and some are rare, and others are still intrinsically rare - for example, the bush dog Speothos venaticus. Abundance of species is assumed to reflect ecological resources of the habitat. Local diversity and number of individuals of wild rodents and marsupials also rely on the offering of ecological resources and behavioural specialisation to microhabitat components. A large number of species interact with the type of the vegetation of the habitat, by means of habitat selection through active patterns of ecological behaviour, resulting on dependency on arboreal and forested habitats of the Pantanal. In addition, mammals respond to seasonal shrinking-and-expansion of habitats due to flooding regime of the Pantanal. The highest number of species is observed during the dry season, when there is a considerable expansion of terrestrial habitats, mainly seasonally flooded grassland. Major threats to mammal species are the loss and alteration of habitats due to human intervention, mainly deforestation, unsustainable agricultural and cattle-ranching practices, which convert the natural vegetation into pastures. The Pantanal still harbours about a dozen of species officially listened

  7. Environmental aspects: - Atmospheric, - aquatic, - terrestrial dispersion of radionuclides

    International Nuclear Information System (INIS)

    Kirchmann, R.

    1982-01-01

    After general introductory remarks the paper deals with the dispersion of radionuclides in the atmosphere and in the aquatic environment as well as with the transfer through the terrestrial environment. (RW)

  8. High Efficiency, High Density Terrestrial Panel. [for solar cell modules

    Science.gov (United States)

    Wohlgemuth, J.; Wihl, M.; Rosenfield, T.

    1979-01-01

    Terrestrial panels were fabricated using rectangular cells. Packing densities in excess of 90% with panel conversion efficiencies greater than 13% were obtained. Higher density panels can be produced on a cost competitive basis with the standard salami panels.

  9. NACP Site: Terrestrial Biosphere Model Output Data in Original Format

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set contains the original model output data submissions from the 24 terrestrial biosphere models (TBM) that participated in the North American...

  10. NACP Site: Terrestrial Biosphere Model Output Data in Original Format

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the original model output data submissions from the 24 terrestrial biosphere models (TBM) that participated in the North American Carbon...

  11. Electrochemical Power Plant for Terrestrial Flight Platforms, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — An electrochemical power plant is proposed by MicroCell Technologies to provide power to terrestrial flight platforms. Our power plant is based upon a proton...

  12. Terrestrial radiation level in selected asphalt plants in Port Harcourt ...

    African Journals Online (AJOL)

    Terrestrial radiation level in selected asphalt plants in Port Harcourt, Nigeria. ... An environmental radiation survey in asphalt processing plants in Rivers State was been carried out ... Therefore the results show significant radiological risk.

  13. Climate control of terrestrial carbon exchange across biomes and continents

    DEFF Research Database (Denmark)

    Yi, Chuixiang; Ricciuto, Daniel; Li, Runze

    2010-01-01

    Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate–carbon cycle feedbacks. However, directly observed relationships betwe...

  14. 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

  15. Floral display, reproductive success, and conservation of terrestrial orchids

    Czech Academy of Sciences Publication Activity Database

    Kindlmann, Pavel; Jersáková, Jana

    2005-01-01

    Roč. 26, - (2005), s. 136-144 ISSN 0361-185X Institutional research plan: CEZ:AV0Z60870520 Keywords : deceptiveness * fruit set * number of flowers * Orchis morio * terrestrial orchids Subject RIV: EH - Ecology, Behaviour

  16. Allium hookeri , Thw. Enum. A lesser known terrestrial perennial ...

    African Journals Online (AJOL)

    A lesser known terrestrial perennial herb used as food and its ethnobotanical ... from the wilderness, for consumption and traditional healing of various ailments. ... plants, the lifestyles of the people are changed and they prefer 'junk foods'.

  17. 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)

  18. Terrestrial Planet Finder Coronagraph High Accuracy Optical Propagation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Terrestrial Planet Finder (TPF) project is considering several approaches to discovering planets orbiting stars far from earth and assessing their suitability to...

  19. 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)

  20. Climate control of terrestrial carbon exchange across biomes and continents

    NARCIS (Netherlands)

    Yi, C.; Ricciuto, D.; Li, R.; Hendriks, D.M.D.; Moors, E.J.; Valentini, R.

    2010-01-01

    Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between

  1. Climate control of terrestrial carbon exchange across biomes and continents

    NARCIS (Netherlands)

    Yi, C.; Jacobs, C.M.J.; Moors, E.J.; Elbers, J.A.

    2010-01-01

    Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate–carbon cycle feedbacks. However, directly observed relationships between

  2. Breast Reduction Surgery

    Science.gov (United States)

    ... considering breast reduction surgery, consult a board-certified plastic surgeon. It's important to understand what breast reduction surgery entails — including possible risks and complications — as ...

  3. Roles of Solar Power from Space for Europe - Space Exploration and Combinations with Terrestrial Solar Plant Concepts

    Science.gov (United States)

    Summerer, L.; Pipoli, T.; Galvez, A.; Ongaro, F.; Vasile, M.

    The paper presents the prospective roles of SPS concepts for Europe, shows the outcome of recent studies undertaken by ESA's Advanced Concepts Team (ACT) together with European industry and research centres and gives insight into planned activities. The main focus is on the assessment of the principal validity and economic viability of solar power from space concepts in the light of advances in alternative sustainable, clean and potentially abundant solar-based terrestrial concepts. The paper takes into account expected changes in the European energy system (e.g. gradual introduction of hydrogen as energy vector). Special emphasis is given to the possibilities of integrating space and terrestrial solar plants. The relative geographic proximity of areas in North Africa with high average solar irradiation to the European energy consumer market puts Europe in a special position regarding the integration of space and terrestrial solar power concepts. The paper presents a method to optimise such an integration, taking into account different possible orbital constellations, terrestrial locations, plant number and sizes as well as consumer profiles and extends the scope from the European-only to a multi continental approach including the fast growing Chinese electricity market. The work intends to contribute to the discussion on long-term options for the European commitment to worldwide CO2 emission reduction. Cleaner electricity generation and environmentally neutral transport fuels (e.g. solar generated hydrogen) might be two major tools in reaching this goal.

  4. Terrestrial carbohydrates support freshwater zooplankton during phytoplankton deficiency

    OpenAIRE

    Taipale, Sami J.; Galloway, Aaron W. E.; Aalto, Sanni L.; Kahilainen, Kimmo K.; Strandberg, Ursula; Kankaala, Paula

    2016-01-01

    Freshwater food webs can be partly supported by terrestrial primary production, often deriving from plant litter of surrounding catchment vegetation. Although consisting mainly of poorly bioavailable lignin, with low protein and lipid content, the carbohydrates from fallen tree leaves and shoreline vegetation may be utilized by aquatic consumers. Here we show that during phytoplankton deficiency, zooplankton (Daphnia magna) can benefit from terrestrial particulate organic matter by using terr...

  5. Microbial rhodopsins on leaf surfaces of terrestrial plants

    OpenAIRE

    Atamna-Ismaeel, Nof; Finkel, Omri M.; Glaser, Fabian; Sharon, Itai; Schneider, Ron; Post, Anton F.; Spudich, John L.; von Mering, Christian; Vorholt, Julia A.; Iluz, David; Béjà, Oded; Belkin, Shimshon

    2011-01-01

    The above-ground surfaces of terrestrial plants, the phyllosphere, comprise the main interface between the terrestrial biosphere and solar radiation. It is estimated to host up to 1026 microbial cells that may intercept part of the photon flux impinging on the leaves. Based on 454-pyrosequencing-generated metagenome data, we report on the existence of diverse microbial rhodopsins in five distinct phyllospheres from tamarisk (Tamarix nilotica), soybean (Glycine max), Arabidopsis (Arabidopsis t...

  6. 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.

  7. 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...

  8. Data base for terrestrial food pathways dose commitment calculations

    International Nuclear Information System (INIS)

    Bailey, C.E.

    1979-01-01

    A computer program is under development to allow calculation of the dose-to-man in Georgia and South Carolina from ingestion of radionuclides in terrestrial foods resulting from deposition of airborne radionuclides. This program is based on models described in Regulatory Guide 1.109 (USNRC, 1977). The data base describes the movement of radionuclides through the terrestrial food chain, growth and consumption factors for a variety of radionuclides

  9. Shell bone histology indicates terrestrial palaeoecology of basal turtles

    OpenAIRE

    Scheyer, Torsten; Sander, P. Martin

    2009-01-01

    The palaeoecology of basal turtles from the Late Triassic was classically viewed as being semi-aquatic, similar to the lifestyle of modern snapping turtles. Lately, this view was questioned based on limb bone proportions, and a terrestrial palaeoecology was suggested for the turtle stem. Here, we present independent shell bone microstructural evidence for a terrestrial habitat of the oldest and basal most well-known turtles, i.e. the Upper Triassic Proterochersis robusta and Proganochelys que...

  10. Hungaria Asteroid Region Telescopic Spectral Survey (HARTSS): Stony Asteroids Abundant in the Background and Family Populations

    Science.gov (United States)

    Lucas, Michael P.; Emery, Joshua P.; Pinilla-Alonso, Noemi; Lindsay, Sean S.; Lorenzi, Vania

    2016-10-01

    The Hungaria region represents a "purgatory" for the closest, preserved samples of the material from which the terrestrial planets accreted. The Hungaria region harbors a collisional family of Xe-type asteroids, which are situated among a background of predominantly S-complex asteroids. Deciphering their surface composition may provide constraints on the nature of the primordial building blocks of the terrestrial planets. We hypothesize that planetesimals in the inner part of the primordial asteroid belt experienced partial- to full-melting and differentiation, the Hungaria region should retain any petrologically-evolved material that formed there.We have undertaken an observational campaign entitled the Hungaria Asteroid Region Telescopic Spectral Survey (HARTSS) to record near-infrared (NIR) spectra to characterize taxonomy, surface mineralogy, and potential meteorite analogs. We used NIR instruments at two ground-based facilities (NASA IRTF; TNG). Our data set includes spectra of 82 Hungaria asteroids (61 background; 21 family), 65 were observed during HARTSS. We compare S-complex background asteroids to calibrations developed via laboratory analyses of ordinary chondrites, and to our analyses (EPMA, XRD, VIS+NIR spectra) of 11 primitive achondrite (acapulcoite-lodranite clan) meteorites.We find that stony S-complex asteroids dominate the Hungaria background population (~80%). Background objects exhibit considerable spectral diversity, when quantified by spectral band parameter measurements, translates to a variety of surface compositions. Two main meteorite groups are represented within the Hungaria background: unmelted, nebular L chondrites (and/or L chondrites), and partially-melted primitive achondrites. H-chondrite mineralogies appear to be absent from the Hungaria background. Xe-type Hungaria family members exhibit spectral homogeneity, consistent with the hypothesis that the family was derived from the disruption of a parent body analogous to an enstatite

  11. Cosmic microwave background polarization results from QUIET

    International Nuclear Information System (INIS)

    Buder, I.

    2014-01-01

    Despite the success of precision cosmology, cosmologists cannot fully explain the initial conditions of the Universe. Inflation, an exponential expansion in the first ∼ 10 -36 s, is a promising potential explanation. A generic prediction of inflation is odd-parity (B-mode) polarization in the cosmic microwave background (CMB). Q/U Imaging Experiment (QUIET) aimed at limiting or detecting this polarization. We built a pseudo-correlation microwave polarimeter as an array of mass-produced modules in the focal plane of a 1.4 m telescope. We used rotation around the absorbing ground screen, a new time-stream double-demodulation technique, and optimized optics in the design to reduce instrumental polarization. We observed with this instrument at the Atacama Plateau in Chile between October 2008 and December 2010. This paper describes the analysis and results of these observations from one of 2 parallel pipelines. We developed noise modeling, filtering and data selection following a blind-analysis strategy. Central to this strategy was a suite of null test, each motivated by a possible instrumental problem or systematic effect. We evaluated the systematic errors in the blind stage of the analysis before the result was known. We calculated the CMB power spectra using a pseudo-C l cross-correlation technique that suppressed contamination and made the result insensitive to noise bias. We measured the first 3 peaks of the E-mode spectrum at high significance and limited B-mode polarization. We measured the CMB polarization power at 25 ≤ l ≤ 975. We found no statistically significant deviation from ΛCDM model, and our results are consistent with zero BB and EB power. Systematic errors were well below our B-mode polarization limits. This systematic-error reduction was a strong demonstration of technology for application in more sensitive, next generation CMB experiments. (author)

  12. Debris disks as signposts of terrestrial planet formation

    Science.gov (United States)

    Raymond, S. N.; Armitage, P. J.; Moro-Martín, A.; Booth, M.; Wyatt, M. C.; Armstrong, J. C.; Mandell, A. M.; Selsis, F.; West, A. A.

    2011-06-01

    There exists strong circumstantial evidence from their eccentric orbits that most of the known extra-solar planetary systems are the survivors of violent dynamical instabilities. Here we explore the effect of giant planet instabilities on the formation and survival of terrestrial planets. We numerically simulate the evolution of planetary systems around Sun-like stars that include three components: (i) an inner disk of planetesimals and planetary embryos; (ii) three giant planets at Jupiter-Saturn distances; and (iii) an outer disk of planetesimals comparable to estimates of the primitive Kuiper belt. We calculate the dust production and spectral energy distribution of each system by assuming that each planetesimal particle represents an ensemble of smaller bodies in collisional equilibrium. Our main result is a strong correlation between the evolution of the inner and outer parts of planetary systems, i.e. between the presence of terrestrial planets and debris disks. Strong giant planet instabilities - that produce very eccentric surviving planets - destroy all rocky material in the system, including fully-formed terrestrial planets if the instabilities occur late, and also destroy the icy planetesimal population. Stable or weakly unstable systems allow terrestrial planets to accrete in their inner regions and significant dust to be produced in their outer regions, detectable at mid-infrared wavelengths as debris disks. Stars older than ~100 Myr with bright cold dust emission (in particular at λ ~ 70 μm) signpost dynamically calm environments that were conducive to efficient terrestrial accretion. Such emission is present around ~16% of billion-year old Solar-type stars. Our simulations yield numerous secondary results: 1) the typical eccentricities of as-yet undetected terrestrial planets are ~0.1 but there exists a novel class of terrestrial planet system whose single planet undergoes large amplitude oscillations in orbital eccentricity and inclination; 2) by

  13. Infinitary Combinatory Reduction Systems: Normalising Reduction Strategies

    NARCIS (Netherlands)

    Ketema, J.; Simonsen, Jakob Grue

    2010-01-01

    We study normalising reduction strategies for infinitary Combinatory Reduction Systems (iCRSs). We prove that all fair, outermost-fair, and needed-fair strategies are normalising for orthogonal, fully-extended iCRSs. These facts properly generalise a number of results on normalising strategies in

  14. Actinide elements in aquatic and terrestrial environments

    International Nuclear Information System (INIS)

    Bondietti, E.A.; Bogle, M.A.; Brantley, J.N.

    1979-01-01

    Progress is reported on the following research projects: water-sediment interactions of U, Pu, Am, and Cm; relative availability of actinide elements from abiotic to aquatic biota; comparative uptake of transuranic elements by biota bordering Pond 3513; metabolic reduction of 239 Np from Np(V) to Np(IV) in cotton rats; evaluation of hazards associated with transuranium releases to the biosphere; predicting Pu in bone; adsorption--solubility--complexation phenomena in actinide partitioning between sorbents and solution; comparative soil extraction data; and comparative plant uptake data

  15. THE EFFECTS OF THE IONIZING RADIATION BACKGROUND ON GALAXY EVOLUTION

    International Nuclear Information System (INIS)

    Hambrick, D. Clay; Ostriker, Jeremiah P.; Naab, Thorsten; Johansson, Peter H.

    2009-01-01

    We find that the amount and nature of the assumed ionizing background can strongly affect galaxy formation and evolution. Galaxy evolution simulations typically incorporate an ultraviolet background which falls off rapidly above z = 3; e.g., that of Haardt and Madau. However, this decline may be too steep to fit the Wilkinson Microwave Anistropy Probe constraints on electron scattering optical depth or observations of intermediate redshift (z ∼ 2-4) Lyα forest transmission. As an alternative, we present simulations of the cosmological formation of individual galaxies with UV backgrounds that decline more slowly at high redshift: both a simple intensity rescaling and the background recently derived by Faucher-Giguere, which softens the spectrum at higher redshifts. We also test an approximation of the X-ray background with a similar z dependence. We find for the test galaxies that an increase in either the intensity or hardness of ionizing radiation generically pushes star formation toward lower redshifts: although overall star formation in the simulation boxes is reduced by 10%-25%, the galaxies show a factor of ∼2 increase in the fraction of stars within a 30 kpc radius that are formed after z = 1. Other effects include late gas inflows enhanced up to 30 times, stellar half-mass radii decreased by up to 30%, central velocity dispersions increased up to 40%, and a strong reduction in substructure. The magnitude of the effects depends on the environmental/accretion properties of the particular galaxy.

  16. Mapping the Relative Probability of Common Toad Occurrence in Terrestrial Lowland Farm Habitat in the United Kingdom.

    Directory of Open Access Journals (Sweden)

    Rosie D Salazar

    Full Text Available The common toad (Bufo bufo is of increasing conservation concern in the United Kingdom (UK due to dramatic population declines occurring in the past century. Many of these population declines coincided with reductions in both terrestrial and aquatic habitat availability and quality and have been primarily attributed to the effect of agricultural land conversion (of natural and semi-natural habitats to arable and pasture fields and pond drainage. However, there is little evidence available to link habitat availability with common toad population declines, especially when examined at a broad landscape scale. Assessing such patterns of population declines at the landscape scale, for instance, require an understanding of how this species uses terrestrial habitat.We intensively studied the terrestrial resource selection of a large population of common toads in Oxfordshire, England, UK. Adult common toads were fitted with passive integrated transponder (PIT tags to allow detection in the terrestrial environment using a portable PIT antenna once toads left the pond and before going into hibernation (April/May-October 2012 and 2013. We developed a population-level resource selection function (RSF to assess the relative probability of toad occurrence in the terrestrial environment by collecting location data for 90 recaptured toads.The predicted relative probability of toad occurrence for this population was greatest in wooded habitat near to water bodies; relative probability of occurrence declined dramatically > 50 m from these habitats. Toads also tended to select habitat near to their breeding pond and toad occurrence was negatively related to urban environments.

  17. Some effects of pollutants in terrestrial ecosystems

    Science.gov (United States)

    Stickel, W.H.; McIntyre, A.D.; Mills, C.F.

    1975-01-01

    occur when persistent chemicals enter organisms that eliminate them poorly. However, loss of chemicals in the food chain must be more common than accumulation. The great concentration from water to aquatic organism is chiefly a physical phenomenon, not a food chain effect, but it affords high starting levels for these chains. Terrestrial food chains often start at a high level with heavily contaminated, struggling prey. Litter feeders are another important base. Vegetation may be contaminated enough to be dangerous to animals that eat it. Dermal and respiratory routes of intoxication occur in the wild, but the oral route is far more important at most times and places. The organisms that govern soil fertility and texture are affected more by cultivation than by pesticides. Above ground, growing knowledge of resistance, species differences, and biological controls is leading to integrated control, in which use of chemicals is limited and specific. We do not know what is happening to most nontarget invertebrates. Amphibians and reptiles may be killed by applications of insecticides, but are not highly sensitive and can carry large residues. Effects of these residues on reproduction are little known. Heavy kills of birds by pesticides still occur in the field. Fish-eating and bird-eating birds also undergo shell thinning and related reproductive troubles in many areas, sometimes to the point of population decline and local or regional extermination. DDE most often correlates with shell thinning in the wild and in experiments. No other known chemical approaches DDE in causing severe and lasting shell thinning. Herbivorous birds seem to be largely immune to this effect. It is uncertain how much dieldrin and PCBs contribute to embryotoxicity in carnivorous birds. Mammals may be killed by the more toxic pesticides, but some of the commonest small rodents are so resistant, and lose their residues so rapidly, that they are of little

  18. Random walks on reductive groups

    CERN Document Server

    Benoist, Yves

    2016-01-01

    The classical theory of Random Walks describes the asymptotic behavior of sums of independent identically distributed random real variables. This book explains the generalization of this theory to products of independent identically distributed random matrices with real coefficients. Under the assumption that the action of the matrices is semisimple – or, equivalently, that the Zariski closure of the group generated by these matrices is reductive - and under suitable moment assumptions, it is shown that the norm of the products of such random matrices satisfies a number of classical probabilistic laws. This book includes necessary background on the theory of reductive algebraic groups, probability theory and operator theory, thereby providing a modern introduction to the topic.

  19. 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.

  20. Water vapor estimation using digital terrestrial broadcasting waves

    Science.gov (United States)

    Kawamura, S.; Ohta, H.; Hanado, H.; Yamamoto, M. K.; Shiga, N.; Kido, K.; Yasuda, S.; Goto, T.; Ichikawa, R.; Amagai, J.; Imamura, K.; Fujieda, M.; Iwai, H.; Sugitani, S.; Iguchi, T.

    2017-03-01

    A method of estimating water vapor (propagation delay due to water vapor) using digital terrestrial broadcasting waves is proposed. Our target is to improve the accuracy of numerical weather forecast for severe weather phenomena such as localized heavy rainstorms in urban areas through data assimilation. In this method, we estimate water vapor near a ground surface from the propagation delay of digital terrestrial broadcasting waves. A real-time delay measurement system with a software-defined radio technique is developed and tested. The data obtained using digital terrestrial broadcasting waves show good agreement with those obtained by ground-based meteorological observation. The main features of this observation are, no need for transmitters (receiving only), applicable wherever digital terrestrial broadcasting is available and its high time resolution. This study shows a possibility to estimate water vapor using digital terrestrial broadcasting waves. In the future, we will investigate the impact of these data toward numerical weather forecast through data assimilation. Developing a system that monitors water vapor near the ground surface with time and space resolutions of 30 s and several kilometers would improve the accuracy of the numerical weather forecast of localized severe weather phenomena.

  1. Reduction in language testing

    DEFF Research Database (Denmark)

    Dimova, Slobodanka; Jensen, Christian

    2013-01-01

    /video recorded speech samples and written reports produced by two experienced raters after testing. Our findings suggest that reduction or reduction-like pronunciation features are found in tested L2 speech, but whenever raters identify and comment on such reductions, they tend to assess reductions negatively......This study represents an initial exploration of raters' comments and actual realisations of form reductions in L2 test speech performances. Performances of three L2 speakers were selected as case studies and illustrations of how reductions are evaluated by the raters. The analysis is based on audio...

  2. Conversion of native terrestrial ecosystems in Hawai‘i to novel grazing systems: a review

    Science.gov (United States)

    Leopold, Christina R.; Hess, Steven C.

    2017-01-01

    The remote oceanic islands of Hawai‘i exemplify the transformative effects that non-native herbivorous mammals can bring to isolated terrestrial ecosystems. We reviewed published literature containing systematically collected, analyzed, and peer-reviewed original data specifically addressing direct effects of non-native hoofed mammals (ungulates) on terrestrial ecosystems, and indirect effects and interactions on ecosystem processes in Hawai‘i. The effects of ungulates on native vegetation and ecosystems were addressed in 58 original studies and mostly showed strong short-term regeneration of dominant native trees and understory ferns after ungulate removal, but unassisted recovery was dependent on the extent of previous degradation. Ungulates were associated with herbivory, bark-stripping, disturbance by hoof action, soil erosion, enhanced nutrient cycling from the interaction of herbivory and grasses, and increased pyrogenicity and competition between native plants and pasture grasses. No studies demonstrated that ungulates benefitted native ecosystems except in short-term fire-risk reduction. However, non-native plants became problematic and continued to proliferate after release from herbivory, including at least 11 species of non-native pasture grasses that had become established prior to ungulate removal. Competition from non-native grasses inhibited native species regeneration where degradation was extensive. These processes have created novel grazing systems which, in some cases, have irreversibly altered Hawaii’s terrestrial ecology. Non-native plant control and outplanting of rarer native species will be necessary for recovery where degradation has been extensive. Lack of unassisted recovery in some locations should not be construed as a reason to not attempt restoration of other ecosystems.

  3. The terrestrial biosphere as a net source of greenhouse gases to the atmosphere.

    Science.gov (United States)

    Tian, Hanqin; Lu, Chaoqun; Ciais, Philippe; Michalak, Anna M; Canadell, Josep G; Saikawa, Eri; Huntzinger, Deborah N; Gurney, Kevin R; Sitch, Stephen; Zhang, Bowen; Yang, Jia; Bousquet, Philippe; Bruhwiler, Lori; Chen, Guangsheng; Dlugokencky, Edward; Friedlingstein, Pierre; Melillo, Jerry; Pan, Shufen; Poulter, Benjamin; Prinn, Ronald; Saunois, Marielle; Schwalm, Christopher R; Wofsy, Steven C

    2016-03-10

    The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and therefore has an important role in regulating atmospheric composition and climate. Anthropogenic activities such as land-use change, agriculture and waste management have altered terrestrial biogenic greenhouse gas fluxes, and the resulting increases in methane and nitrous oxide emissions in particular can contribute to climate change. The terrestrial biogenic fluxes of individual greenhouse gases have been studied extensively, but the net biogenic greenhouse gas balance resulting from anthropogenic activities and its effect on the climate system remains uncertain. Here we use bottom-up (inventory, statistical extrapolation of local flux measurements, and process-based modelling) and top-down (atmospheric inversions) approaches to quantify the global net biogenic greenhouse gas balance between 1981 and 2010 resulting from anthropogenic activities and its effect on the climate system. We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010. This results in a net positive cumulative impact of the three greenhouse gases on the planetary energy budget, with a best estimate (in petagrams of CO2 equivalent per year) of 3.9 ± 3.8 (top down) and 5.4 ± 4.8 (bottom up) based on the GWP100 metric (global warming potential on a 100-year time horizon). Our findings suggest that a reduction in agricultural methane and nitrous oxide emissions, particularly in Southern Asia, may help mitigate climate change.

  4. Environmental forcing of terrestrial carbon isotope excursion amplification across five Eocene hyperthermals

    Science.gov (United States)

    Bowen, G. J.; Abels, H.

    2015-12-01

    Abrupt changes in the isotope composition of exogenic carbon pools accompany many major episodes of global change in the geologic record. The global expression of this change in substrates that reflect multiple carbon pools provides important evidence that many events reflect persistent, global redistribution of carbon between reduced and oxidized stocks. As the diversity of records documenting any event grows, however, discrepancies in the expression of carbon isotope change among substrates are almost always revealed. These differences in magnitude, pace, and pattern of change can complicate interpretations of global carbon redistribution, but under ideal circumstances can also provide additional information on changes in specific environmental and biogeochemical systems that accompanied the global events. Here we evaluate possible environmental influences on new terrestrial records of the negative carbon isotope excursions (CIEs) associated with multiple hyperthermals of the Early Eocene, which show a common pattern of amplified carbon isotope change in terrestrial paleosol carbonate records relative to that recorded in marine substrates. Scaling relationships between climate and carbon-cycle proxies suggest that that the climatic (temperature) impact of each event scaled proportionally with the magnitude of its marine CIE, likely implying that all events involved release of reduced carbon with a similar isotopic composition. Amplification of the terrestrial CIEs, however, does not scale with event magnitude, being proportionally less for the first, largest event (the PETM). We conduct a sensitivity test of a coupled plant-soil carbon isotope model to identify conditions that could account for the observed CIE scaling. At least two possibilities consistent with independent lines of evidence emerge: first, varying effects of pCO2 change on photosynthetic carbon isotope discrimination under changing background pCO2, and second, contrasting changes in regional

  5. Impacts of large-scale climatic disturbances on the terrestrial carbon cycle

    Directory of Open Access Journals (Sweden)

    Lucht Wolfgang

    2006-07-01

    Full Text Available Abstract Background The amount of carbon dioxide in the atmosphere steadily increases as a consequence of anthropogenic emissions but with large interannual variability caused by the terrestrial biosphere. These variations in the CO2 growth rate are caused by large-scale climate anomalies but the relative contributions of vegetation growth and soil decomposition is uncertain. We use a biogeochemical model of the terrestrial biosphere to differentiate the effects of temperature and precipitation on net primary production (NPP and heterotrophic respiration (Rh during the two largest anomalies in atmospheric CO2 increase during the last 25 years. One of these, the smallest atmospheric year-to-year increase (largest land carbon uptake in that period, was caused by global cooling in 1992/93 after the Pinatubo volcanic eruption. The other, the largest atmospheric increase on record (largest land carbon release, was caused by the strong El Niño event of 1997/98. Results We find that the LPJ model correctly simulates the magnitude of terrestrial modulation of atmospheric carbon anomalies for these two extreme disturbances. The response of soil respiration to changes in temperature and precipitation explains most of the modelled anomalous CO2 flux. Conclusion Observed and modelled NEE anomalies are in good agreement, therefore we suggest that the temporal variability of heterotrophic respiration produced by our model is reasonably realistic. We therefore conclude that during the last 25 years the two largest disturbances of the global carbon cycle were strongly controlled by soil processes rather then the response of vegetation to these large-scale climatic events.

  6. Measurement of the natural radiation background level of Riyadh City

    International Nuclear Information System (INIS)

    Al-Kusayer, T.A.; Al-Haj, A.N.

    1987-01-01

    A gamma spectroscopy system was used to analyze the radionuclides in soil samples and to determine the cumulative radioactivity of terrestrial origin in the Riyadh City area. Minimal work has been done in the 1980s to measure the natural background radiation level in Saudi Arabia by using thermoluminescent dosimeters. The measurement of the natural radioactivity in the Riyadh area for the radionuclide concentration in becquerels per kilogram, the exposure rate arising from radionuclides in grays per hour, and the equivalent dose rate in sieverts per hour are the goals of this work. Soil samples were collected from 21 places in Riyadh City. Each site was sampled for two depth profiles, 0 to 5 cm and 5 to 15 cm. These measurements were taken before the Chernobyl accident, and in the absence of any measurements for that area in the past, this work can be considered in future work for a reference 137 Cs concentration in Riyadh soil to determine the 137 Cs increase in the soil after the Chernobyl accident

  7. Background outdoor radiation dose to inhabitants around Narwapahar mine

    International Nuclear Information System (INIS)

    Srivastava, V.S.; Jha, V.N.; Topno, R.; Dandpat, B.L.; Patnaik, R.I.; Kumar, R.; Tripathi, R.M.; Puranik, V.D.

    2012-01-01

    Mining of uranium ore due to their inherent radiological characteristics may lead to release radionuclides into the environment. Monitoring of radiological parameters in the villages surrounding the mining areas are of significant concern for the evaluation of public exposure. The monitoring objectives will include the natural distribution of radionuclides in the environment as well as contribution of the source (mine), if any. Radon and its short lived progeny present in the environment contributes maximum natural background radiation dose due to inhalation. Apart from this, terrestrial radionuclides ( 238 U, 232 Th series and 40 K) present in trace level in earth crust are significant contributor of external exposure in the environment. The variation in the levels of these radionuclides depends on the geological strata of the area. Measured radiological parameters are comparable to the global average variation of exposure level due to these natural sources. Statistical treatment of the database reveals that the variation in radon and gamma level is natural and contribution of mining activities at the site is insignificant. The same is attributed to natural uranium mineralization of Singhbhum shear zone. Apart from this, seasonal variation in radon profile is globally reported

  8. Terrestrial floral change during the ETM2 hyperthermal

    Science.gov (United States)

    Wing, S. L.; Currano, E. D.

    2017-12-01

    Hyperthermal events during the Eocene are defined by negative shifts in carbon isotope composition, global temperature increase and carbonate dissolution in marine settings. These features suggest repeated releases of large amounts of carbon followed by increasing concentration of CO2in the atmosphere and ocean, climate change, and biotic responses such as rapid evolution and changes in geographic range and trophic relationships. The Paleocene-Eocene Thermal Maximum (PETM, 56.0 Ma) is the largest Eocene hyperthermal in terms of carbon cycle, climate and biotic effects, including dwarfing of mammalian lineages. Terrestrial floral turnover at the PETM documented in the Bighorn Basin, Wyoming, USA, is very high. Almost all late Paleocene species, most belonging to mesic, warm-temperate lineages, disappeared during the PETM. The PETM flora was composed of species belonging to dry tropical lineages present only during the body of the PETM. Most mesic, warm-temperate species returned to the area immediately after the PETM. Such extreme change in floral composition makes it difficult to assess how much floral turnover is associated with how much change in temperature. The ETM2 hyperthermal event ( 53.7 Ma) is characterized by a carbon isotope excursion and warming about half as great as during the PETM, and by half as much mammalian dwarfing. Here we report on a new fossil flora from ETM2 that demonstrates the magnitude of floral change was also less than during the PETM. Some characteristic PETM plant species reappeared in the Bighorn Basin during ETM2, including species of Fabaceae that dominate PETM assemblages but are less common during ETM2. Many stratigraphically long-ranging plant species that preferred mesic climates remain common in the ETM2 flora. We conclude that warm climate during ETM2 shifted ranges of plant species such that some PETM species returned to northern Wyoming, but was not so severe as to cause local extirpation of species preferring 'background

  9. Terrestrial microbes in martian and chondritic meteorites

    Science.gov (United States)

    Airieau, S.; Picenco, Y.; Andersen, G.

    2007-08-01

    Introduction: The best extraterrestrial analogs for microbiology are meteorites. The chemistry and mineralogy of Asteroid Belt and martian (SNC) meteorites are used as tracers of processes that took place in the early solar system. Meteoritic falls, in particular those of carbonaceous chondrites, are regarded as pristine samples of planetesimal evolution as these rocks are primitive and mostly unprocessed since the formation of the solar system 4.56 billion years ago. Yet, questions about terrestrial contamination and its effects on the meteoritic isotopic, chemical and mineral characteristics often arise. Meteorites are hosts to biological activity as soon as they are in contact with the terrestrial biosphere, like all rocks. A wide biodiversity was found in 21 chondrites and 8 martian stones, and was investigated with cell culture, microscopy techniques, PCR, and LAL photoluminetry. Some preliminary results are presented here. The sample suite included carbonaceous chondrites of types CR, CV, CK, CO, CI, and CM, from ANSMET and Falls. Past studies documented the alteration of meteorites by weathering and biological activity [1]-[4]. Unpublished observations during aqueous extraction for oxygen isotopic analysis [5], noted the formation of biofilms in water in a matter of days. In order to address the potential modification of meteoritic isotopic and chemical signatures, the culture of microbial contaminating species was initiated in 2005, and after a prolonged incubation, some of the species obtained from cell culture were analyzed in 2006. The results are preliminary, and a systematic catalog of microbial contaminants is developing very slowly due to lack of funding. Methods: The primary method was cell culture and PCR. Chondrites. Chondritic meteorite fragments were obtained by breaking stones of approximately one gram in sterile mortars. The core of the rocks, presumably less contaminated than the surface, was used for the present microbial study, and the

  10. TERRESTRIAL, HABITABLE-ZONE EXOPLANET FREQUENCY FROM KEPLER

    International Nuclear Information System (INIS)

    Traub, Wesley A.

    2012-01-01

    Data from Kepler's first 136 days of operation are analyzed to determine the distribution of exoplanets with respect to radius, period, and host-star spectral type. The analysis is extrapolated to estimate the percentage of terrestrial, habitable-zone (HZ) exoplanets. The Kepler census is assumed to be complete for bright stars (magnitude 0.5 Earth radius and periods β–1 , with β ≅ 0.71 ± 0.08; and an extrapolation to longer periods gives the frequency of terrestrial planets in the HZs of FGK stars as η ⊕ ≅ (34 ± 14)%. Thus about one-third of FGK stars are predicted to have at least one terrestrial, HZ planet.

  11. Busting dust: from cosmic grains to terrestrial microbes

    International Nuclear Information System (INIS)

    Mendis, D.A.

    2001-01-01

    Electrostatic charging can have important consequences for both the growth and disruption of microparticulates immersed in a plasma. In this topical review, my emphasis is on the latter process, while I extend the term microparticulates not only to include ordinary inanimate cosmic or terrestrial dust but also to include terrestrial microbes whose sizes range from tens of nanometers (viruses) to tens of micrometers (bacteria). Following a description of the basic mechanism of electrostatic disruption of a solid body, I will discuss the role of size, shape and surface irregularity on the process. I will also consider the mitigating role of electric field emission of electrons on the disruption process of a negatively charged grain as its size falls below a critical size. I will conclude by reviewing some early evidence for the electrostatic disruption of cosmic grains, and the very recent evidence for the electrostatic disruption of the bacterial cell membranes in terrestrial sterilization experiments. (orig.)

  12. [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.

  13. Distribution of {sup 129}I in terrestrial surface water environments

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xuegao [State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098 (China); College of Hydrology and Water Resources, Hohai University, Nanjing (China); Gong, Meng [College of Hydrology and Water Resources, Hohai University, Nanjing (China); Yi, Peng, E-mail: pengyi1915@163.com [State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098 (China); College of Hydrology and Water Resources, Hohai University, Nanjing (China); Aldahan, Ala [Department of Earth Sciences, Uppsala University, Uppsala (Sweden); Department of Geology, United Arab Emirates University, Al Ain (United Arab Emirates); Yu, Zhongbo [State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098 (China); College of Hydrology and Water Resources, Hohai University, Nanjing (China); Possnert, Göran [Tandem Laboratory, Uppsala University, Uppsala (Sweden); Chen, Li [State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098 (China); College of Hydrology and Water Resources, Hohai University, Nanjing (China)

    2015-10-15

    The global distribution of the radioactive isotope iodine-129 in surface waters (lakes and rivers) is presented here and compared with the atmospheric deposition and distribution in surface marine waters. The results indicate relatively high concentrations in surface water systems in close vicinity of the anthropogenic release sources as well as in parts of Western Europe, North America and Central Asia. {sup 129}I level is generally higher in the terrestrial surface water of the Northern hemisphere compared to the southern hemisphere. The highest values of {sup 129}I appear around 50°N and 40°S in the northern and southern hemisphere, separately. Direct gaseous and marine atmospheric emissions are the most likely avenues for the transport of {sup 129}I from the sources to the terrestrial surface waters. To apply iodine-129 as process tracer in terrestrial surface water environment, more data are needed on {sup 129}I distribution patterns both locally and globally.

  14. Earth as a radio source: terrestrial kilometric radiation. Progress report

    International Nuclear Information System (INIS)

    Gurnett, D.A.

    1974-02-01

    Radio wave experiments on the IMP-6 and 8 satellites have shown that the earth emits very intense electromagnetic radiation in the frequency range from about 50 kHz to 500 kHz. A peak intensity the total power emitted in this frequency range is about 1 billion watts. The earth is, therefore, a very intense planetary radio source, with a total power output comparable to the decametric radio emission from Jupiter. This radio emission from the earth is referred to as terrestrial kilometric radiation. Terrestrial kilometric radiation appears to originate from low altitudes (less than 3.0 Re) in the auroral region. Possible mechanisms which can explain the generation and propagation of the terrestrial kilometric radiation are discussed. (U.S.)

  15. Microalgal and Terrestrial Transport Biofuels to Displace Fossil Fuels

    Directory of Open Access Journals (Sweden)

    Lucas Reijnders

    2009-02-01

    Full Text Available Terrestrial transport biofuels differ in their ability to replace fossil fuels. When both the conversion of solar energy into biomass and the life cycle inputs of fossil fuels are considered, ethanol from sugarcane and biodiesel from palm oil do relatively well, if compared with ethanol from corn, sugar beet or wheat and biodiesel from rapeseed. When terrestrial biofuels are to replace mineral oil-derived transport fuels, large areas of good agricultural land are needed: about 5x108 ha in the case of biofuels from sugarcane or oil palm, and at least 1.8-3.6x109 ha in the case of ethanol from wheat, corn or sugar beet, as produced in industrialized countries. Biofuels from microalgae which are commercially produced with current technologies do not appear to outperform terrestrial plants such as sugarcane in their ability to displace fossil fuels. Whether they will able to do so on a commercial scale in the future, is uncertain.

  16. Mercury in the Canadian Arctic terrestrial environment: an update.

    Science.gov (United States)

    Gamberg, Mary; Chételat, John; Poulain, Alexandre J; Zdanowicz, Christian; Zheng, Jiancheng

    2015-03-15

    Contaminants in the Canadian Arctic have been studied over the last twenty years under the guidance of the Northern Contaminants Program. This paper provides the current state of knowledge on mercury (Hg) in the Canadian Arctic terrestrial environment. Snow, ice, and soils on land are key reservoirs for atmospheric deposition and can become sources of Hg through the melting of terrestrial ice and snow and via soil erosion. In the Canadian Arctic, new data have been collected for snow and ice that provide more information on the net accumulation and storage of Hg in the cryosphere. Concentrations of total Hg (THg) in terrestrial snow are highly variable but on average, relatively low (Porcupine caribou herd vary among years but there has been no significant increase or decrease over the last two decades. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Simulation of Experimental Background using FLUKA

    Energy Technology Data Exchange (ETDEWEB)

    Rokni, Sayed

    1999-05-11

    In November 1997, Experiment T423 began acquiring data with the intentions of understanding the energy spectra of high-energy neutrons generated in the interaction of electrons with lead. The following describes a series of FLUKA simulations studying (1) particle yields in the absence of all background; (2) the background caused from scattering in the room; (3) the effects of the thick lead shielding which surrounded the detector; (4) the sources of neutron background created in this lead shielding; and (5) the ratio of the total background to the ideal yield. In each case, particular attention is paid to the neutron yield.

  18. Modeling the Thermal Signature of Natural Backgrounds

    National Research Council Canada - National Science Library

    Gamborg, Marius

    2002-01-01

    Two measuring stations have been established the purpose being to collect comprehensive databases of thermal signatures of background elements in addition to the prevailing meteorological conditions...

  19. Terrestrial dissolved organic matter distribution in the North Sea.

    Science.gov (United States)

    Painter, Stuart C; Lapworth, Dan J; Woodward, E Malcolm S; Kroeger, Silke; Evans, Chris D; Mayor, Daniel J; Sanders, Richard J

    2018-07-15

    The flow of terrestrial carbon to rivers and inland waters is a major term in the global carbon cycle. The organic fraction of this flux may be buried, remineralized or ultimately stored in the deep ocean. The latter can only occur if terrestrial organic carbon can pass through the coastal and estuarine filter, a process of unknown efficiency. Here, data are presented on the spatial distribution of terrestrial fluorescent and chromophoric dissolved organic matter (FDOM and CDOM, respectively) throughout the North Sea, which receives organic matter from multiple distinct sources. We use FDOM and CDOM as proxies for terrestrial dissolved organic matter (tDOM) to test the hypothesis that tDOM is quantitatively transferred through the North Sea to the open North Atlantic Ocean. Excitation emission matrix fluorescence and parallel factor analysis (EEM-PARAFAC) revealed a single terrestrial humic-like class of compounds whose distribution was restricted to the coastal margins and, via an inverse salinity relationship, to major riverine inputs. Two distinct sources of fluorescent humic-like material were observed associated with the combined outflows of the Rhine, Weser and Elbe rivers in the south-eastern North Sea and the Baltic Sea outflow to the eastern central North Sea. The flux of tDOM from the North Sea to the Atlantic Ocean appears insignificant, although tDOM export may occur through Norwegian coastal waters unsampled in our study. Our analysis suggests that the bulk of tDOM exported from the Northwest European and Scandinavian landmasses is buried or remineralized internally, with potential losses to the atmosphere. This interpretation implies that the residence time in estuarine and coastal systems exerts an important control over the fate of tDOM and needs to be considered when evaluating the role of terrestrial carbon losses in the global carbon cycle. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

  20. 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.

  1. Evaluation of radiological doses to the terrestrial plants around Trombay

    International Nuclear Information System (INIS)

    Ajay Kumar; Singhal, R.K.; Preetha, J.; Joshi, S.N.; Hegde, A.G.

    2005-01-01

    Existing policies for radiation protection do not provide explicit criteria for the protection of species other than humans, i.e. not for flora and fauna. Concern over this omission is now being widely expressed and moves are under way to evaluate the doses to terrestrial and aquatic biota. During the present work radiological doses (external and internal) to the terrestrial plants were evaluated by estimating the concentration of anthropogenic ( 137 Cs, 90 Sr) and natural radionuclides ( 238 U, 232 Th and 40 K) in the plant leaves and by measuring the external gamma radiation due to different radionuclide. The soil and vegetation sample were collected from fifteen sampling locations around the different locations at Trombay. The samples were processed as per IAEA (International Atomic Energy Agency) protocol for the estimation of naturally occurring and anthropogenic radionuclides in soil and terrestrial plants. The gamma emitting radionuclides were measured by high resolution gamma (HPGe) spectrometry system. Maximum exposure (external + internal) to the terrestrial plants was observed due to 232 Th while 238 U showed minimum exposure. The average value of radiation exposure to the terrestrial plants for 40 K, 137 Cs, 90 Sr, 238 U and 232 Th was 1555.2 ± 92.4, 691.2 ± 54.3, 2564.1 ± 534.9, 82.5 ±5.2, and 4419.6 ± 1165.5 μGy/y respectively. The radiation exposure (external + internal ) to the terrestrial plants due to all radionuclides was found within the permissible limits (i.e. 10 mGy/d) as per recommended by the United States, Department of Energy (DOE). (author)

  2. Transformation procedures in 3D terrestrial coordinate systems

    Directory of Open Access Journals (Sweden)

    Sedlák Vladimír

    2001-12-01

    Full Text Available Transformation procedures belong to the main tasks of surveyor working in a field of geodesy, for example in satellite geodesy or astronomical geodesy. It is necessary to know transformation procedures in 3D terrestrial (Earth coordinate systems. Increasingly a dynamic advance growth of application of satellite navigation systems, for example GPS (Global Positioning System into engineering surveying, real estate register and others spheres of applied geodesy and geo-surveying (mine surveying exacts knowledge of these transformation procedures between coordinates in various coordinate systems. These tasks are common for daily work for various practical surveyors too, not only for theoretical scientific working surveyors.Conventional Terrestrial System is 3D coordinate system what is the most important coordinate system in global geodesy. Conventional Terrestrial System is an approximation of the nature coordinate system of the Earth. The origin of this coordinate system is placed in the earth substantial centre of gravity and in the centre of geoid. Conventional Terrestrial System is the Cartesian right-handed coordinate system, i.e. positive one. The Local Astronomical System is 3D coordinate system too and it belongs to an important coordinate system in geodesy from its practical point of view. Many geodetic measurements are realized in this coordinate system. Designation of this coordinate system as astronomical system expresses its sticking to a normal line to an equipotential plane, i.e. to a vertical. Local Astronomical system is the left-handed cartesian coordinate system.Transformation procedures in 3D terrestrial coordinate systems with theory of these systems are presented in the paper. Transformation in the local astronomical coordinate system presents common transformation in a frame of an adjustment of various local geodetic networks. In a case of satellite measurements (GPS, satellite altimetry, etc. transformation between local and

  3. Linking terrestrial and marine conservation planning and threats analysis.

    Science.gov (United States)

    Tallis, Heather; Ferdaña, Zach; Gray, Elizabeth

    2008-02-01

    The existence of the Gulf of Mexico dead zone makes it clear that marine ecosystems can be damaged by terrestrial inputs. Marine and terrestrial conservation planning need to be aligned in an explicit fashion to fully represent threats to marine systems. To integrate conservation planning for terrestrial and marine systems, we used a novel threats assessment that included 5 cross-system threats in a site-prioritization exercise for the Pacific Northwest coast ecoregion (U.S.A.). Cross-system threats are actions or features in one ecological realm that have effects on species in another realm. We considered bulkheads and other forms of shoreline hardening threats to terrestrial systems and roads, logging, agriculture, and urban areas threats to marine systems. We used 2 proxies of freshwater influence on marine environments, validated against a mechanistic model and field observations, to propagate land-based threats into marine sites. We evaluated the influence of cross-system threats on conservation priorities by comparing MARXAN outputs for 3 scenarios that identified terrestrial and marine priorities simultaneously: (1) no threats, (2) single-system threats, and (3) single- and cross-system threats. Including cross-system threats changed the threat landscape dramatically. As a result the best plan that included only single-system threats identified 323 sites (161,500 ha) at risk from cross-system threats. Including these threats changed the location of best sites. By comparing the best and sum solutions of the single- and cross-system scenarios, we identified areas ideal for preservation or restoration through integrated management. Our findings lend quantitative support to the call for explicitly integrated decision making and management action in terrestrial and marine ecosystems.

  4. Microbial characterization of toluene-degrading denitrifying consortia obtained from terrestrial and marine ecosystems.

    Science.gov (United States)

    An, Y-J; Joo, Y-H; Hong, I-Y; Ryu, H-W; Cho, K-S

    2004-10-01

    The degradation characteristics of toluene coupled to nitrate reduction were investigated in enrichment culture and the microbial communities of toluene-degrading denitrifying consortia were characterized by denaturing gradient gel electrophoresis (DGGE) technique. Anaerobic nitrate-reducing bacteria were enriched from oil-contaminated soil samples collected from terrestrial (rice field) and marine (tidal flat) ecosystems. Enriched consortia degraded toluene in the presence of nitrate as a terminal electron acceptor. The degradation rate of toluene was affected by the initial substrate concentration and co-existence of other hydrocarbons. The types of toluene-degrading denitrifying consortia depended on the type of ecosystem. The clone RS-7 obtained from the enriched consortium of the rice field was most closely related to a toluene-degrading and denitrifying bacterium, Azoarcus denitrificians (A. tolulyticus sp. nov.). The clone TS-11 detected in the tidal flat enriched consortium was affiliated to Thauera sp. strain S2 (T. aminoaromatica sp. nov.) that was able to degrade toluene under denitrifying conditions. This indicates that environmental factors greatly influence microbial communities obtained from terrestrial (rice field) and marine (tidal flat) ecosystems.

  5. Current and future impacts of ultraviolet radiation on the terrestrial carbon balance

    Institute of Scientific and Technical Information of China (English)

    W. Kolby SMITH; Wei GAO; Heidi STELTZER

    2009-01-01

    One of the most documented effects of human activity on our environment is the reduction of stratospheric ozone resulting in an increase of biologically harmful ultraviolet (UV) radiation. In a less predictable manner, UV radiation incident at the surface of the earth is expected to be further modified in the future as a result of altered cloud condition, atmospheric aerosol concentration, and snow cover. Although UV radiation comprises only a small fraction of the total solar radiation that is incident at the earth's surface, it has the greatest energy per unit wavelength and, thus, the greatest potential to damage the biosphere. Recent investigations have highlighted numerous ways that UV radiation could potentially affect a variety of ecological processes, including nutrient cycling and the terrestrial carbon cycle. The objectives of the following literature review are to summarize and synthesize the available information relevant to the effects of UV radiation and other climate change factors on the terrestrial carbon balance in an effort to highlight current gaps in knowledge and future research directions for UV radiation research.

  6. The potential role of earthworms in toxicity assessment of terrestrial hazardous waste sites

    Energy Technology Data Exchange (ETDEWEB)

    Goven, A.J.; Fitzpatrick, L.C. [Univ. of North Texas, Denton, TX (United States); Venables, B.J. [TRAC Labs., Inc., Denton, TX (United States)

    1994-12-31

    Understanding the toxic potential and mechanisms of action of environmental xenobiotics is fundamental for assessing risk to public and environmental health. Current established protocols with earthworms focus primarily on defining the lethal effects of chemicals associated with soil contamination. Development of sublethal assays, until recently, has been largely ignored. Here the authors develop rationale for use of earthworms as a model organism for comprehensive assessment of risks to higher wildlife from contaminated soils and hazardous waste sites. They present a panel of lethal (LC/LD50`s) and sublethal measurement endpoint biomarkers, developed within the framework of the National Toxicology Program`s tiered immunotoxicity protocol for mice and according to published criteria for good measurement endpoints, that represent sensitive phylogenetically-conserved processes. Specifically the authors discuss immunosuppressive effects of terrestrial heavy metal and organic contamination on the innate, nonspecific and specific immune responses of earthworm, Lumbricus terrestris, coelomocytes in terms of total and differential cell counts, lysozyme activity, nitroblue tetrazolium dye reduction, phagocytic activity and secretary rosette formation. Findings indicate that sensitive phylogenetically conserved immune responses present in invertebrates can be used to assess or predict risk to wildlife from contaminated soils.

  7. The thermal state and evolution of the earth and terrestrial planets

    International Nuclear Information System (INIS)

    Tozer, D.C.

    1977-01-01

    In considering the problem of planetary evolution it is suggested that a completely fresh look at the working of the heat transfer process has made it possible to give a general interpretation of many of the recent discoveries of the Earth's present dynamism and past development without appealing to any but very general assumptions about the material behaviour. Once again, the flow properties of rock are in the forefront of the understanding of the Earth's internal heat while the temperature has somewhat receded into the background as a determined rather than a determining characteristic of the behaviour of the terrestrial planets (Mercury, Venus, Earth, Mars) and the Moon. Misunderstanding about the nature of material properties has made theorists go too far in seeing planets as aggregates of potential laboratory samples, rather than as systems in their own right whose sheer size brings out behaviour requiring distinct ways of describing in situ planetary material. Study of the way in which the evolution of the terrestrial planets becomes regulated by a degree of creep resistance that is quite impossible to measure in the laboratory underlines the similarity of this situation with that which faced attempts to understand stellar evolution. (U.K.)

  8. Antifungal activity of terrestrial Streptomyces rochei strain HF391 against clinical azole -resistant Aspergillus fumigatus

    Science.gov (United States)

    Hadizadeh, S; Forootanfar, H; Shahidi Bonjar, GH; Falahati Nejad, M; Karamy Robati, A; Ayatollahi Mousavi, SA; Amirporrostami, S

    2015-01-01

    Background and Purpose: Actinomycetes have been discovered as source of antifungal compounds that are currently in clinical use. Invasive aspergillosis (IA) due to Aspergillus fumigatus has been identified as individual drug-resistant Aspergillus spp. to be an emerging pathogen opportunities a global scale. This paper described the antifungal activity of one terrestrial actinomycete against the clinically isolated azole-resistant A. fumigatus. Materials and Methods: Soil samples were collected from various locations of Kerman, Iran. Thereafter, the actinomycetes were isolated using starch-casein-nitrate-agar medium and the most efficient actinomycetes (capable of inhibiting A. fumigatus) were screened using agar block method. In the next step, the selected actinomycete was cultivated in starch-casein- broth medium and the inhibitory activity of the obtained culture broth was evaluated using agar well diffusion method. Results: The selected actinomycete, identified as Streptomyces rochei strain HF391, could suppress the growth of A. fumigatus isolates which was isolated from the clinical samples of patients treated with azoles. This strain showed higher inhibition zones on agar diffusion assay which was more than 15 mm. Conclusion: The obtained results of the present study introduced Streptomyces rochei strain HF391 as terrestrial actinomycete that can inhibit the growth of clinically isolated A. fumigatus. PMID:28680984

  9. MCNP variance reduction overview

    International Nuclear Information System (INIS)

    Hendricks, J.S.; Booth, T.E.

    1985-01-01

    The MCNP code is rich in variance reduction features. Standard variance reduction methods found in most Monte Carlo codes are available as well as a number of methods unique to MCNP. We discuss the variance reduction features presently in MCNP as well as new ones under study for possible inclusion in future versions of the code

  10. Modern Reduction Methods

    CERN Document Server

    Andersson, Pher G

    2008-01-01

    With its comprehensive overview of modern reduction methods, this book features high quality contributions allowing readers to find reliable solutions quickly and easily. The monograph treats the reduction of carbonyles, alkenes, imines and alkynes, as well as reductive aminations and cross and heck couplings, before finishing off with sections on kinetic resolutions and hydrogenolysis. An indispensable lab companion for every chemist.

  11. A statistical background noise correction sensitive to the steadiness of background noise.

    Science.gov (United States)

    Oppenheimer, Charles H

    2016-10-01

    A statistical background noise correction is developed for removing background noise contributions from measured source levels, producing a background noise-corrected source level. Like the standard background noise corrections of ISO 3741, ISO 3744, ISO 3745, and ISO 11201, the statistical background correction increases as the background level approaches the measured source level, decreasing the background noise-corrected source level. Unlike the standard corrections, the statistical background correction increases with steadiness of the background and is excluded from use when background fluctuation could be responsible for measured differences between the source and background noise levels. The statistical background noise correction has several advantages over the standard correction: (1) enveloping the true source with known confidence, (2) assuring physical source descriptions when measuring sources in fluctuating backgrounds, (3) reducing background corrected source descriptions by 1 to 8 dB for sources in steady backgrounds, and (4) providing a means to replace standardized background correction caps that incentivize against high precision grade methods.

  12. Hanford Site background: Part 1, Soil background for nonradioactive analytes. Revision 1, Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    Volume two contains the following appendices: Description of soil sampling sites; sampling narrative; raw data soil background; background data analysis; sitewide background soil sampling plan; and use of soil background data for the detection of contamination at waste management unit on the Hanford Site.

  13. Terrestrial neutron-induced soft errors in advanced memory devices

    CERN Document Server

    Nakamura, Takashi; Ibe, Eishi; Yahagi, Yasuo; Kameyama, Hideaki

    2008-01-01

    Terrestrial neutron-induced soft errors in semiconductor memory devices are currently a major concern in reliability issues. Understanding the mechanism and quantifying soft-error rates are primarily crucial for the design and quality assurance of semiconductor memory devices. This book covers the relevant up-to-date topics in terrestrial neutron-induced soft errors, and aims to provide succinct knowledge on neutron-induced soft errors to the readers by presenting several valuable and unique features. Sample Chapter(s). Chapter 1: Introduction (238 KB). Table A.30 mentioned in Appendix A.6 on

  14. Environmental radionuclides tracers and timers of terrestrial processes

    CERN Document Server

    Froehlich, Klaus

    2009-01-01

    The book presents a state-of-the-art summary of knowledge on the use of radionuclides to study processes and systems in the continental part of the Earth's environment. It is conceived as a companion to the two volumes of this series, which deal with isotopes as tracers in the marine environment (Livingston, Marine Radioactivity) and with the radioecology of natural and man-made terrestrial systems (Shaw, Radioactivity in Terrestrial Ecosystems). Although the book focuses on natural and anthropogenic radionuclides (radioactive isotopes), it also refers to stable environmental isotopes, which i

  15. Terrestrial radioactivity monitoring programme (TRAMP) report for 1986

    International Nuclear Information System (INIS)

    1988-01-01

    The Ministry of Agriculture, Fisheries and Food (MAFF) undertakes a comprehensive independent monitoring programme for radioactivity in terrestrial foodstuffs in England and Wales, this report presents the results from the first full year of operation of this programme and complements the data published annually by the Ministry's Directorate of Fisheries Research in respect of the aquatic environment. This work is undertaken in Wales on behalf of the Secretary of State. The Terrestrial Radioactivity Monitoring Programme (TRAMP) concentrates on samples of agricultural produce (milk, crops, meat) collected from the vicinity of the major nuclear sites in England and Wales and is independent of monitoring undertaken for various purposes by site operators. (author)

  16. Comparision of the Martian Gullies With Terrestrial Ones

    Science.gov (United States)

    Cedillo-Flores, Y.; Durand-Manterola, H. J.

    2005-12-01

    Some of the geomorphological features in Mars are the gullies. Some theories developed tried to explained its origin, either by liquid water, liquid carbon dioxide or flows of dry granular material. We made a comparative analysis of the Martian gullies with the terrestrial ones. We present the characteristics of some terrestrial gullies formed at cold enviroment, sited at the Nevado de Toluca volcanoe near Toluca City, Mexico. We compare them with Martian gullies, choisen from four different areas, to recognize possible processes evolved in its formation. Also, we measured the lenghts of those Martian gullies and their range was from 24 m 1775 m.

  17. Cumulus convection and the terrestrial water-vapor distribution

    Science.gov (United States)

    Donner, Leo J.

    1988-01-01

    Cumulus convection plays a significant role in determining the structure of the terrestrial water vapor field. Cumulus convection acts directly on the moisture field by condensing and precipitating water vapor and by redistributing water vapor through cumulus induced eddy circulations. The mechanisms by which cumulus convection influences the terrestrial water vapor distribution is outlined. Calculations using a theory due to Kuo is used to illustrate the mechanisms by which cumulus convection works. Understanding of these processes greatly aids the ability of researchers to interpret the seasonal and spatial distribution of atmospheric water vapor by providing information on the nature of sources and sinks and the global circulation.

  18. Pulses, linkages, and boundaries of coupled aquatic-terrestrial ecosystems

    Science.gov (United States)

    Tockner, K.

    2009-04-01

    Riverine floodplains are linked ecosystems where terrestrial and aquatic habitats overlap, creating a zone where they interact, the aquatic-terrestrial interface. The interface or boundary between aquatic and terrestrial habitats is an area of transition, contact or separation; and connectivity between these habitats may be defined as the ease with which organisms, matter or energy traverse these boundaries. Coupling of aquatic and terrestrial systems generates intertwining food webs, and we may predict that coupled systems are more productive than separated ones. For example, riparian consumers (aquatic and terrestrial) have alternative prey items external to their respective habitats. Such subsidized assemblages occupy a significant higher trophic position than assemblages in unsubsidized areas. Further, cross-habitat linkages are often pulsed; and even small pulses of a driver (e.g. short-term increases in flow) can cause major resource pulses (i.e. emerging aquatic insects) that control the recipient community. For example, short-term additions of resources, simulating pulsed inputs of aquatic food to terrestrial systems, suggest that due to resource partitioning and temporal separation among riparian arthropod taxa the resource flux from the river to the riparian zone increases with increasing riparian consumer diversity. I will discuss the multiple transfer and transformation processes of matter and organisms across aquatic-terrestrial habitats. Key landscape elements along river corridors are vegetated islands that function as instream riparian areas. Results from Central European rivers demonstrate that islands are in general more natural than fringing riparian areas, contribute substantially to total ecotone length, and create diverse habitats in the aquatic and terrestrial realm. In braided rivers, vegetated islands are highly productive landscape elements compared to the adjacent aquatic area. However, aquatic habitats exhibit a much higher decomposition

  19. Polarization for Background Reduction in EDXRF - The Technique That Would Not Work

    International Nuclear Information System (INIS)

    Ryon, R W

    2002-01-01

    As with all electromagnet radiation, polarization of x-rays is a general phenomenon. Such polarization has been known since the classic experiments of Barkla in 1906. The general implementation of polarization to x-ray analysis had to await the fixed geometry of energy-dispersive systems. The means of optimizing these systems is shown in this review paper. Improved detection limits are the result

  20. Low Noise Infrasonic Sensor System with High Reduction of Natural Background Noise

    National Research Council Canada - National Science Library

    Kern, F; Africk, S; Cataldi, P; Chaves, R

    2006-01-01

    ...) coaxial cables, theoretically of arbitrary length, specially terminated and connected to state of the art, ultra high input impedance quiet amplifiers, tailored to the unique characteristics of the sensor outputs...

  1. Vacuum treatment of CR-39 for the reduction of background in neutron induced autoradiography of boron

    International Nuclear Information System (INIS)

    Freyer, K.; Treutler, H.C.; Dietze, K.; Hunyadi, I.; Csige, I.; Somogyi, G.

    1991-01-01

    The influence of etching time and vacuum processing before, during, and after neutron irradiation on the ''signal/noise'' ratio of the neutron induced autoradiography of boron using CR-39 track detectors has been investigated. The neutron irradiation was carried out in a vacuum chamber using the Cf-252 neutron source of the Central Institute of Isotope and Radiation Research at Leipzig. Hungarian-made CR-39 type track detectors, MA-ND/p and MA-ND/α, produced in different years, are compared. After a few hours of 2 kPa (about 10 -2 Torr) vacuum treatment, the ''signal/noise'' ratio for boron determination is improved remarkably in most cases of the detector and etching-time combinations used. (author)

  2. Vacuum treatment of CR-39 for the reduction of background in neutron induced autoradiography of boron

    Energy Technology Data Exchange (ETDEWEB)

    Freyer, K.; Treutler, H.C.; Dietze, K. (Central Inst. of Isotope and Radiation Research, Leipzig (Germany, F.R.)); Hunyadi, I.; Csige, I.; Somogyi, G. (Magyar Tudomanyos Akademia, Debrecen (Hungary). Atommag Kutato Intezete)

    1991-01-01

    The influence of etching time and vacuum processing before, during, and after neutron irradiation on the ''signal/noise'' ratio of the neutron induced autoradiography of boron using CR-39 track detectors has been investigated. The neutron irradiation was carried out in a vacuum chamber using the Cf-252 neutron source of the Central Institute of Isotope and Radiation Research at Leipzig. Hungarian-made CR-39 type track detectors, MA-ND/p and MA-ND/{alpha}, produced in different years, are compared. After a few hours of 2 kPa (about 10{sup -2} Torr) vacuum treatment, the ''signal/noise'' ratio for boron determination is improved remarkably in most cases of the detector and etching-time combinations used. (author).

  3. A new method for background rejection with surface sensitive bolometers

    International Nuclear Information System (INIS)

    Nones, C.; Foggetta, L.; Giuliani, A.; Pedretti, M.; Salvioni, C.; Sangiorgio, S.

    2006-01-01

    We report the performance of three prototype TeO 2 macrobolometers, able to identify events due to energy deposited at the detector surface. This capability is obtained by thermally coupling thin active layers to the main absorber of the bolometer, and is proved by irradiating the detectors with alpha particles. This technique can be very useful in view of background study and reduction for the CUORE experiment, a next generation Double Beta Decay search based on TeO 2 macrobolometers and to be installed in the Laboratori Nazionali del Gran Sasso

  4. Clean air strategy for Alberta: Background project reports

    International Nuclear Information System (INIS)

    1991-06-01

    As a background to the development of a clean air strategy for Alberta, reports are presented which cover the definition of what clean air is, the applicability of full cost accounting to this strategy, market-based approaches to managing Alberta air emissions, gas and electric utility incentives programs for energy efficiency, energy efficiency legislation in Alberta and other jurisdictions, initiatives which address emissions reduction in the transportation sector, coordination of science and technology relevant to clean air issues, and initiatives in energy and environmental education

  5. 41 CFR 128-1.8001 - Background.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Background. 128-1.8001 Section 128-1.8001 Public Contracts and Property Management Federal Property Management Regulations System (Continued) DEPARTMENT OF JUSTICE 1-INTRODUCTION 1.80-Seismic Safety Program § 128-1.8001 Background. The...

  6. Introduction to the background field method

    International Nuclear Information System (INIS)

    Abbott, L.F.; Brandeis Univ., Waltham, MA

    1982-01-01

    The background field approach to calculations in gauge field theories is presented. Conventional functional techniques are reviewed and the background field method is introduced. Feynman rules and renormalization are discussed and, as an example, the Yang-Mills β function is computed. (author)

  7. 12 CFR 408.1 - Background.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Background. 408.1 Section 408.1 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES PROCEDURES FOR COMPLIANCE WITH THE NATIONAL ENVIRONMENTAL POLICY ACT General § 408.1 Background. (a) The National Environmental Policy Act (NEPA) of 1969 (42 U.S.C...

  8. Observing a Gravitational Wave Background With Lisa

    National Research Council Canada - National Science Library

    Tinto, M; Armstrong, J; Estabrook, F

    2000-01-01

    .... Comparison of the conventional Michelson interferometer observable with the fully-symmetric Sagnac data-type allows unambiguous discrimination between a gravitational wave background and instrumental noise. The method presented here can be used to detect a confusion-limited gravitational wave background.

  9. 28 CFR 23.2 - Background.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Background. 23.2 Section 23.2 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL INTELLIGENCE SYSTEMS OPERATING POLICIES § 23.2 Background. It is... potential threats to the privacy of individuals to whom such data relates, policy guidelines for Federally...

  10. 16 CFR 1404.2 - Background.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Background. 1404.2 Section 1404.2 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS CELLULOSE INSULATION § 1404.2 Background. Based on available fire incident information, engineering analysis of the probable...

  11. DNDO Report: Predicting Solar Modulation Potentials for Modeling Cosmic Background Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Behne, Patrick Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-08

    The modeling of the detectability of special nuclear material (SNM) at ports and border crossings requires accurate knowledge of the background radiation at those locations. Background radiation originates from two main sources, cosmic and terrestrial. Cosmic background is produced by high-energy galactic cosmic rays (GCR) entering the atmosphere and inducing a cascade of particles that eventually impact the earth’s surface. The solar modulation potential represents one of the primary inputs to modeling cosmic background radiation. Usosokin et al. formally define solar modulation potential as “the mean energy loss [per unit charge] of a cosmic ray particle inside the heliosphere…” Modulation potential, a function of elevation, location, and time, shares an inverse relationship with cosmic background radiation. As a result, radiation detector thresholds require adjustment to account for differing background levels, caused partly by differing solar modulations. Failure to do so can result in higher rates of false positives and failed detection of SNM for low and high levels of solar modulation potential, respectively. This study focuses on solar modulation’s time dependence, and seeks the best method to predict modulation for future dates using Python. To address the task of predicting future solar modulation, we utilize both non-linear least squares sinusoidal curve fitting and cubic spline interpolation. This material will be published in transactions of the ANS winter meeting of November, 2016.

  12. a Method for Simultaneous Aerial and Terrestrial Geodata Acquisition for Corridor Mapping

    Science.gov (United States)

    Molina, P.; Blázquez, M.; Sastre, J.; Colomina, I.

    2015-08-01

    In this paper, we present mapKITE, a new mobile, simultaneous terrestrial and aerial, geodata collection and post-processing method. On one side, the method combines a terrestrial mobile mapping system (TMMS) with an unmanned aerial mapping one, both equipped with remote sensing payloads (at least, a nadir-looking visible-band camera in the UA) by means of which aerial and terrestrial geodata are acquired simultaneously. This tandem geodata acquisition system is based on a terrestrial vehicle (TV) and on an unmanned aircraft (UA) linked by a 'virtual tether', that is, a mechanism based on the real-time supply of UA waypoints by the TV. By means of the TV-to-UA tether, the UA follows the TV keeping a specific relative TV-to-UA spatial configuration enabling the simultaneous operation of both systems to obtain highly redundant and complementary geodata. On the other side, mapKITE presents a novel concept for geodata post-processing favoured by the rich geometrical aspects derived from the mapKITE tandem simultaneous operation. The approach followed for sensor orientation and calibration of the aerial images captured by the UA inherits the principles of Integrated Sensor Orientation (ISO) and adds the pointing-and-scaling photogrammetric measurement of a distinctive element observed in every UA image, which is a coded target mounted on the roof of the TV. By means of the TV navigation system, the orientation of the TV coded target is performed and used in the post-processing UA image orientation approach as a Kinematic Ground Control Point (KGCP). The geometric strength of a mapKITE ISO network is therefore high as it counts with the traditional tie point image measurements, static ground control points, kinematic aerial control and the new point-and-scale measurements of the KGCPs. With such a geometry, reliable system and sensor orientation and calibration and eventual further reduction of the number of traditional ground control points is feasible. The different

  13. Beam-gas Background Observations at LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00214737; The ATLAS collaboration; Alici, Andrea; Lazic, Dragoslav-Laza; Alemany Fernandez, Reyes; Alessio, Federico; Bregliozzi, Giuseppe; Burkhardt, Helmut; Corti, Gloria; Guthoff, Moritz; Manousos, Athanasios; Sjoebaek, Kyrre; D'Auria, Saverio

    2017-01-01

    Observations of beam-induced background at LHC during 2015 and 2016 are presented in this paper. The four LHC experiments use the non-colliding bunches present in the physics-filling pattern of the accelerator to trigger on beam-gas interactions. During luminosity production the LHC experiments record the beam-gas interactions using dedicated background monitors. These data are sent to the LHC control system and are used to monitor the background levels at the experiments during accelerator operation. This is a very important measurement, since poor beam-induced background conditions can seriously affect the performance of the detectors. A summary of the evolution of the background levels during 2015 and 2016 is given in these proceedings.

  14. PENGARUH BACKGROUND MAHASISWA TERHADAP KINERJA AKADEMIK

    Directory of Open Access Journals (Sweden)

    Trianasari Angkawijaya

    2014-09-01

    Full Text Available Abstract: The Effect of Students’ Background on Academic Performance. This study examines the effect of background variables on the academic performance of accounting students in a private university in Surabaya. The background variables under study included previous academic performance, prior knowledge on accounting, sex, motivation, preparedness, and expectations. The results show that previous academic performance, motivation, and expectations have positive and significant effects on the students’ overall academic performance in accounting, while preparedness affects only the students’ performance in management accounting. In contrast, prior knowledge on accounting and sex do not give significant impacts to the students’ overall academic performance.These findings indicate the importance of previous aca­demic performance as well as motivation and expectations as background variables in current academic performance. Keywords: students’ background, academic performance, accounting Abstrak: Pengaruh Background Mahasiswa terhadap Kinerja Akademik. Penelitian ini mengkaji pengaruh variabel background terhadap kinerja akademik mahasiswa akuntansi di Universitas Surabaya. Lima variabel background utama dipergunakan, yaitu kinerja akademik sebelumnya, pengetahuan akun­tansi sebelumnya, jenis kelamin, motivasi, kesiapan, dan ekspektasi. Hipotesis diuji menggunakan model regresi linier berganda OLS dan Robust Standar Error. Hasil penelitian memerlihatkan bahwa kinerja akademik sebelumnya, motivasi, dan ekspektasi memiliki pengaruh positif signifikan terhadap kinerja akademik keseluruhan, sementara kesiapan memberikan pengaruh positif hanya pada kinerja akademik akuntansi manajemen. Sebaliknya, pengetahuan akuntansi sebelumnya dan jenis kelamin tidak memberi­kan pengaruh signifikan terhadap kinerja akademik keseluruhan. Temuan ini mengindikasikan bahwa kinerja akademik sebelumnya beserta motivasi dan ekspektasi adalah variabel background

  15. Potential cost savings with terrestrial rabies control

    Directory of Open Access Journals (Sweden)

    Cherry Bryan

    2007-04-01

    Full Text Available Abstract Background The cost-benefit of raccoon rabies control strategies such as oral rabies vaccination (ORV are under evaluation. As an initial quantification of the potential cost savings for a control program, the collection of selected rabies cost data was pilot tested for five counties in New York State (NYS in a three-year period. Methods Rabies costs reported to NYS from the study counties were computerized and linked to a human rabies exposure database. Consolidated costs by county and year were averaged and compared. Results Reported rabies-associated costs for all rabies variants totalled $2.1 million, for human rabies postexposure prophylaxes (PEP (90.9%, animal specimen preparation/shipment to laboratory (4.7%, and pet vaccination clinics (4.4%. The proportion that may be attributed to raccoon rabies control was 37% ($784,529. Average costs associated with the raccoon variant varied across counties from $440 to $1,885 per PEP, $14 to $44 per specimen, and $0.33 to $15 per pet vaccinated. Conclusion Rabies costs vary widely by county in New York State, and were associated with human population size and methods used by counties to estimate costs. Rabies cost variability must be considered in developing estimates of possible ORV-related cost savings. Costs of PEPs and specimen preparation/shipments, as well as the costs of pet vaccination provided by this study may be valuable for development of more realistic scenarios in economic modelling of ORV costs versus benefits.

  16. Background {sup 99m}Tc-methoxyisobutylisonitrile uptake of breast-specific gamma imaging in relation to background parenchymal enhancement in magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hai-Jeon; Kim, Bom Sahn [Ewha Womans University, Department of Nuclear Medicine, Yangchun-Ku, Seoul (Korea, Republic of); Kim, Yemi [Ewha Womans University, Clinical Research Institute and Department of Conservative Dentistry, Seoul (Korea, Republic of); Lee, Jee Eun [Ewha Womans University, Department of Radiology, Seoul (Korea, Republic of)

    2015-01-15

    This study investigated factors that could affect background uptake of {sup 99m}Tc- methoxyisobutylisonitrile (MIBI) on normal breast by breast-specific gamma imaging (BSGI). In addition, the impact of background {sup 99m}Tc-MIBI uptake on the diagnostic performance of BSGI was further investigated. One hundred forty-five women with unilateral breast cancer who underwent BSGI, MRI, and mammography were retrospectively enrolled. Background uptake on BSGI was evaluated qualitatively and quantitatively. Patients were classified into non-dense and dense breast groups according to mammographic breast density. Background parenchymal enhancement (BPE) was rated according to BI-RADS classification. The relationship of age, menopausal status, mammographic breast density, and BPE with background {sup 99m}Tc-MIBI uptake was analyzed. Heterogeneous texture and high background uptake ratio on BSGI were significantly correlated with younger age (p < 0.001, respectively), premenopausal status (p < 0.001 and p = 0.003), dense breast (p < 0.001, respectively), and marked BPE (p < 0.001, respectively). On multivariate analysis, only BPE remained a significant factor for background MIBI uptake (p < 0.001).There was a significant reduction in positive predictive value (p = 0.024 and p = 0.002) as background MIBI uptake and BPE grade increased. BPE on MRI was the most important factor for background MIBI uptake on BSGI. High background MIBI uptake or marked BPE can diminish the diagnostic performance of BSGI. (orig.)

  17. Recent Changes in Global Photosynthesis and Terrestrial Ecosystem Respiration Constrained From Multiple Observations

    Science.gov (United States)

    Li, Wei; Ciais, Philippe; Wang, Yilong; Yin, Yi; Peng, Shushi; Zhu, Zaichun; Bastos, Ana; Yue, Chao; Ballantyne, Ashley P.; Broquet, Grégoire; Canadell, Josep G.; Cescatti, Alessandro; Chen, Chi; Cooper, Leila; Friedlingstein, Pierre; Le Quéré, Corinne; Myneni, Ranga B.; Piao, Shilong

    2018-01-01

    To assess global carbon cycle variability, we decompose the net land carbon sink into the sum of gross primary productivity (GPP), terrestrial ecosystem respiration (TER), and fire emissions and apply a Bayesian framework to constrain these fluxes between 1980 and 2014. The constrained GPP and TER fluxes show an increasing trend of only half of the prior trend simulated by models. From the optimization, we infer that TER increased in parallel with GPP from 1980 to 1990, but then stalled during the cooler periods, in 1990-1994 coincident with the Pinatubo eruption, and during the recent warming hiatus period. After each of these TER stalling periods, TER is found to increase faster than GPP, explaining a relative reduction of the net land sink. These results shed light on decadal variations of GPP and TER and suggest that they exhibit different responses to temperature anomalies over the last 35 years.

  18. Protective effect of Tribulus terrestris linn on liver and kidney in cadmium intoxicated rats.

    Science.gov (United States)

    Lakshmi, G Dhana; Kumar, P Ravi; Bharavi, K; Annapurna, P; Rajendar, B; Patel, Pankaj T; Kumar, C S V Satish; Rao, G S

    2012-02-01

    Administration of cadmium (Cd) significantly increased the peroxidation markers such as malondialdehyde and protein carbonyls along with significant decrease in antioxidant markers such as super oxide dismutase and reduced glutathione in liver and kidney tissues. Cadmium also caused a significant alteration in hepatic and renal functional markers in serum viz. total protein, albumin, alanine transaminase, blood urea nitrogen and creatinine. Prominent pathological changes observed in liver were severe vascular and sinusoidal congestion with diffuse degenerative changes and mononuclear infiltration into peripheral areas, while the kidney showed vascular and glomerular congestion, cloudy swelling of tubular epithelium. Coadministration of ethonolic extract of T. terrestris or vitamin E along with Cd significantly reversed the Cd induced changes along with significant reduction in Cd load.

  19. Forest wildfire, fuel reduction treatments, and landscape carbon stocks: a sensitivity analysis

    Science.gov (United States)

    John L. Campbell; Alan A. Ager

    2013-01-01

    Fuel reduction treatments prescribed in fire-suppressed forests of western North America pose an apparent paradox with respect to terrestrial carbon management. Such treatments have the immediate effect of reducing forest carbon stocks but likely reduce future carbon losses through the combustion and mortality caused by high-severity wildfires. Assessing the long-term...

  20. TEMPERATURE ANISOTROPY IN THE PRESENCE OF ULTRA LOW FREQUENCY WAVES IN THE TERRESTRIAL FORESHOCK

    International Nuclear Information System (INIS)

    Selzer, L. A.; Hnat, B.; Osman, K. T.; Nakariakov, V. M.; Eastwood, J. P.; Burgess, D.

    2014-01-01

    We report the first study of the correlation between elevated solar wind core plasma temperatures and temperature anisotropy in the terrestrial foreshock. Plasma temperature is enhanced near the fire hose marginal stability threshold in the presence of ultra low frequency (ULF) large amplitude magnetic perturbations, which are intrinsically right-hand circularly polarized. Direct comparison of contemporaneous anisotropic temperatures in the upstream solar wind and the foreshock suggests that the net heating of plasma is mediated via increase of the parallel temperature in the foreshock region where the ULF waves are present. We consider the possibility that a mechanism based on Landau damping, where solar wind plasma temperature parallel to the background magnetic field is increased by interaction with oblique compressible fast magneto-acoustic ULF waves, influences temperature anisotropy

  1. TEMPERATURE ANISOTROPY IN THE PRESENCE OF ULTRA LOW FREQUENCY WAVES IN THE TERRESTRIAL FORESHOCK

    Energy Technology Data Exchange (ETDEWEB)

    Selzer, L. A.; Hnat, B.; Osman, K. T.; Nakariakov, V. M. [Centre for Fusion, Space and Astrophysics, University of Warwick, Coventry CV4 7AL (United Kingdom); Eastwood, J. P. [Space and Atmospheric Physics, The Blackett Laboratory, Imperial College London, London (United Kingdom); Burgess, D., E-mail: L.A.Selzer@warwick.ac.uk [School of Physics and Astronomy, Queen Mary University of London (United Kingdom)

    2014-06-10

    We report the first study of the correlation between elevated solar wind core plasma temperatures and temperature anisotropy in the terrestrial foreshock. Plasma temperature is enhanced near the fire hose marginal stability threshold in the presence of ultra low frequency (ULF) large amplitude magnetic perturbations, which are intrinsically right-hand circularly polarized. Direct comparison of contemporaneous anisotropic temperatures in the upstream solar wind and the foreshock suggests that the net heating of plasma is mediated via increase of the parallel temperature in the foreshock region where the ULF waves are present. We consider the possibility that a mechanism based on Landau damping, where solar wind plasma temperature parallel to the background magnetic field is increased by interaction with oblique compressible fast magneto-acoustic ULF waves, influences temperature anisotropy.

  2. Installation of a muon veto for low background gamma spectroscopy at the LBNL low-background facility

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, K.J., E-mail: kjthomas@lbl.gov [Department of Nuclear Engineering, University of California, Berkeley, CA 94720 (United States); Nuclear Science Division, Lawrence Berkeley Laboratory, CA 94720 (United States); Norman, E.B. [Department of Nuclear Engineering, University of California, Berkeley, CA 94720 (United States); Nuclear Science Division, Lawrence Berkeley Laboratory, CA 94720 (United States); Smith, A.R.; Chan, Y.D. [Nuclear Science Division, Lawrence Berkeley Laboratory, CA 94720 (United States)

    2013-10-01

    An active veto system consisting of plastic scintillation panels was installed outside the Pb shielding of a 115% n-type HPGe detector in an effort to reduce background continuum generated by cosmic ray muons on the surface. The Low Background Facility at the Lawrence Berkeley National Laboratory performs low level assay (generally of primordial U, Th, K) of candidate construction materials for experiments that require a high level of radiopurity. The counting is performed in two facilities: one local surface site and a remote underground site of approximately 600 m.w.e. For the recently installed veto system at the surface location, the top scintillator panel has been in use for nearly 1 year and the full 3π anticoincidence shield was commissioned into normal counting operations in January 2013. The integrated background from 20 to 3600 keV is reduced overall by a factor of 8, where most of the energy spectrum above 100 keV achieves an overall reduction that varies from 8 to 10. A dramatic improvement of peak-to-background across the entire continuum is observed, greatly enhancing low-level peaks that would otherwise be obscured.

  3. Direct effect of acid rain on leaf chlorophyll content of terrestrial plants in China.

    Science.gov (United States)

    Du, Enzai; Dong, Dan; Zeng, Xuetong; Sun, Zhengzhong; Jiang, Xiaofei; de Vries, Wim

    2017-12-15

    Anthropogenic emissions of acid precursors in China have resulted in widespread acid rain since the 1980s. Although efforts have been made to assess the indirect, soil mediated ecological effects of acid rain, a systematic assessment of the direct foliage injury by acid rain across terrestrial plants is lacking. Leaf chlorophyll content is an important indicator of direct foliage damage and strongly related to plant productivity. We synthesized data from published literature on experiments of simulated acid rain, by directly exposing plants to acid solutions with varying pH levels, to assess the direct effect of acid rain on leaf chlorophyll content across 67 terrestrial plants in China. Our results indicate that acid rain substantially reduces leaf chlorophyll content by 6.71% per pH unit across the recorded plant species. The direct reduction of leaf chlorophyll content due to acid rain exposure showed no significant difference across calcicole, ubiquist or calcifuge species, implying that soil acidity preference does not influence the sensitivity to leaf injury by acid rain. On average, the direct effects of acid rain on leaf chlorophyll on trees, shrubs and herbs were comparable. The effects, however varied across functional groups and economic use types. Specifically, leaf chlorophyll content of deciduous species was more sensitive to acid rain in comparison to evergreen species. Moreover, vegetables and fruit trees were more sensitive to acid rain than other economically used plants. Our findings imply a potential production reduction and economic loss due to the direct foliage damage by acid rain. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Enchytraeids as indicator organisms for chemical stress in terrestrial ecosystems

    NARCIS (Netherlands)

    Didden, W.; Römbke, J.

    2001-01-01

    This review article surveys the available data on enchytraeid sensitivity toward chemical stress, and the effects of chemical stress on enchytraeid communities in terrestrial ecosystems. The factors affecting bioavailability of stressors to enchytraeids and the nature of direct and indirect effects

  5. Facial trauma among victims of terrestrial transport accidents.

    Science.gov (United States)

    d'Avila, Sérgio; Barbosa, Kevan Guilherme Nóbrega; Bernardino, Ítalo de Macedo; da Nóbrega, Lorena Marques; Bento, Patrícia Meira; E Ferreira, Efigênia Ferreira

    2016-01-01

    In developing countries, terrestrial transport accidents - TTA, especially those involving automobiles and motorcycles - are a major cause of facial trauma, surpassing urban violence. This cross-sectional census study attempted to determine facial trauma occurrence with terrestrial transport accidents etiology, involving cars, motorcycles, or accidents with pedestrians in the northeastern region of Brazil, and examine victims' socio-demographic characteristics. Morbidity data from forensic service reports of victims who sought care from January to December 2012 were analyzed. Altogether, 2379 reports were evaluated, of which 673 were related to terrestrial transport accidents and 103 involved facial trauma. Three previously trained and calibrated researchers collected data using a specific form. Facial trauma occurrence rate was 15.3% (n=103). The most affected age group was 20-29 years (48.3%), and more men than women were affected (2.81:1). Motorcycles were involved in the majority of accidents resulting in facial trauma (66.3%). The occurrence of facial trauma in terrestrial transport accident victims tends to affect a greater proportion of young and male subjects, and the most prevalent accidents involve motorcycles. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  6. Incorporation of microplastics from litter into burrows of Lumbricus terrestris

    NARCIS (Netherlands)

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

    2017-01-01

    Pollution caused by plastic debris is an urgent environmental problem. Here, we assessed the effects of microplastics in the soil surface litter on the formation and characterization of burrows built by the anecic earthworm Lumbricus terrestris in soil and quantified the amount of microplastics that

  7. Automatic registration of terrestrial point cloud using panoramic reflectance images

    NARCIS (Netherlands)

    Kang, Z.

    2008-01-01

    Much attention is paid to registration of terrestrial point clouds nowadays. Research is carried out towards improved efficiency and automation of the registration process. This paper reports a new approach for point clouds registration utilizing reflectance panoramic images. The approach follows a

  8. Heritability of sperm length in the bumblebee Bombus terrestris

    DEFF Research Database (Denmark)

    Baer, Boris; de Jong, Gerdien; Schmid-Hempel, Regula

    2006-01-01

    estimates of narrow sense heritability of sperm length in a social insect, the bumblebee Bombus terrestris. In spite of a balanced and straightforward rearing design of colonies, and the possibility to replicate measurements of sperm within single males nested within colonies, the analysis proved...

  9. A larval hunger signal in the bumblebee Bombus terrestris

    DEFF Research Database (Denmark)

    Den Boer, Susanne Petronella A; Duchateau, Marie-Jose

    2006-01-01

    Larvae of Bombus terrestris, a pollen-storing bumblebee, are dependent on progressive provisioning by workers. We test the hypothesis that larval cuticular chemicals can act as a hunger signal. We first show with a new classical conditioning experiment, using a Y-shaped tube, that workers can...

  10. Herbivores Enforce Sharp Boundaries Between Terrestrial and Aquatic Ecosystems

    NARCIS (Netherlands)

    Sarneel, Judith M.; Huig, N.; Veen, G. F.; Rip, W.; Bakker, E. S.

    2014-01-01

    The transitions between ecosystems (ecotones) are often biodiversity hotspots, but we know little about the forces that shape them. Today, often sharp boundaries with low diversity are found between terrestrial and aquatic ecosystems. This has been attributed to environmental factors that hamper

  11. Terrestrial acidification during the end-Permian biosphere crisis?

    NARCIS (Netherlands)

    Sephton, Mark A.; Jiao, Dan; Engel, Michael H.; Looy, Cindy V.; Visscher, Henk

    Excessive acid rainfall associated with emplacement of the Siberian Traps magmatic province is increasingly accepted as a major contributing factor to the end-Permian biosphere crisis. However, direct proxy evidence of terrestrial acidification is so far not available. In this paper, we seek to

  12. Heinrich event 4 characterized by terrestrial proxies in southwestern Europe

    Directory of Open Access Journals (Sweden)

    J. M. López-García

    2013-05-01

    Full Text Available Heinrich event 4 (H4 is well documented in the North Atlantic Ocean as a cooling event that occurred between 39 and 40 Ka. Deep-sea cores around the Iberian Peninsula coastline have been analysed to characterize the H4 event, but there are no data on the terrestrial response to this event. Here we present for the first time an analysis of terrestrial proxies for characterizing the H4 event, using the small-vertebrate assemblage (comprising small mammals, squamates and amphibians from Terrassa Riera dels Canyars, an archaeo-palaeontological deposit located on the seaboard of the northeastern Iberian Peninsula. This assemblage shows that the H4 event is characterized in northeastern Iberia by harsher and drier terrestrial conditions than today. Our results were compared with other proxies such as pollen, charcoal, phytolith, avifauna and large-mammal data available for this site, as well as with the general H4 event fluctuations and with other sites where H4 and the previous and subsequent Heinrich events (H5 and H3 have been detected in the Mediterranean and Atlantic regions of the Iberian Peninsula. We conclude that the terrestrial proxies follow the same patterns as the climatic and environmental conditions detected by the deep-sea cores at the Iberian margins.

  13. Remote sensing the vulnerability of vegetation in natural terrestrial ecosystems

    Science.gov (United States)

    Alistair M. S. Smith; Crystal A. Kolden; Wade T. Tinkham; Alan F. Talhelm; John D. Marshall; Andrew T. Hudak; Luigi Boschetti; Michael J. Falkowski; Jonathan A. Greenberg; John W. Anderson; Andrew Kliskey; Lilian Alessa; Robert F. Keefe; James R. Gosz

    2014-01-01

    Climate change is altering the species composition, structure, and function of vegetation in natural terrestrial ecosystems. These changes can also impact the essential ecosystem goods and services derived from these ecosystems. Following disturbances, remote-sensing datasets have been used to monitor the disturbance and describe antecedent conditions as a means of...

  14. A Google Earth Grand Tour of the Terrestrial Planets

    Science.gov (United States)

    De Paor, Declan; Coba, Filis; Burgin, Stephen

    2016-01-01

    Google Earth is a powerful instructional resource for geoscience education. We have extended the virtual globe to include all terrestrial planets. Downloadable Keyhole Markup Language (KML) files (Google Earth's scripting language) associated with this paper include lessons about Mercury, Venus, the Moon, and Mars. We created "grand…

  15. Terrestrial ecological responses of climate change in the Northern hemisphere

    International Nuclear Information System (INIS)

    Forchhammer, M.C.

    2001-01-01

    Focusing on the single most important atmospheric phenomenon in the Northern hemisphere, the North Atlantic Oscillation (NAO), the author reviews the recent studies coupling the NAO with the ecology of a wide range of terrestrial organisms. In particular, the author focuses on low variations in the NAO affect phenotypic variation in life history Traits and, ultimately, dynamics of populations and of interacting species. (LN)

  16. A review of climate change effects on terrestrial rangeland birds

    Science.gov (United States)

    D. M. Finch; K. E. Bagne; M. M. Friggens; D. M. Smith; K. M. Brodhead

    2011-01-01

    We evaluated existing literature on predicted and known climate change effects on terrestrial rangeland birds. We asked the following questions: 1) How does climate change affect birds? 2) How will birds respond to climate change? 3) Are species already responding? 4) How will habitats be impacted?

  17. Medicinal properties, phytochemistry and pharmacology of tribulus terrestris l. (zygophyllaceae)

    International Nuclear Information System (INIS)

    Hashim, S.; Bakht, T.

    2014-01-01

    Tribulus terrestris (puncture vine) belongs to family Zygophyllaceae and it is a herbaceous, mat forming plant in nature. It extensively grows in warm dry tropics all over the world and ecologically adaptated as a typical C4 xeromorphic plant. T. terrestris is a noxious weed along with its use in many countries as a folk medicine for different purposes from time immemorial. Ancient records describe various medicinal properties of T. terrestris as a popular source to cure variety of different disease conditions in China, India, and Greece. The plant is used directly as a herb or as a main component for production of a number of medicines and food supplements such as for physical rejuvenation, therapy for the conditions affecting liver, kidney, cardiovascular system and immune systems. Also it is used as a folk medicine for increased muscle strength, sexual potency and in treatments of urinary infections, heart diseases and cough. It is considered invigorating stimulant, aphrodisiac, and nutritive. This review discusses the most commonly recognized medicinal properties of this herb. The chemistry of T. terrestris extracts to establish the relationship between medicinal properties of this important plant will also be reviewed. (author)

  18. Data acquisition considerations for Terrestrial Laser Scanning of forest plots

    NARCIS (Netherlands)

    Wilkes, Phil; Lau Sarmiento, Alvaro; Disney, Mathias; Calders, Kim; Burt, Andrew; Gonzalez De Tanago Meñaca, J.; Bartholomeus, Harm; Brede, Benjamin; Herold, Martin

    2017-01-01

    The poor constraint of forest Above Ground Biomass (AGB) is responsible, in part, for large uncertainties in modelling future climate scenarios. Terrestrial Laser Scanning (TLS) can be used to derive unbiased and non-destructive estimates of tree structure and volume and can, therefore, be used to

  19. Endogenous circadian regulation of carbon dioxide exchange in terrestrial ecosystems

    Science.gov (United States)

    We tested the hypothesis that diurnal changes in terrestrial CO2 exchange are driven exclusively by the direct effect of the physical environment on plant physiology. We failed to corroborate this assumption, finding instead large diurnal fluctuations in whole ecosystem carbon assimilation across a ...

  20. Integration of Satellite and Terrestrial Networks at JPL

    Science.gov (United States)

    Pinck, D. S.

    1995-01-01

    This presentation focuses on the activities at JPL on the integration of satellite and terrestrial networks for mobile and personal communications. Activities fall into two categories: 1)advanced systems work, and 2)laboratory and field experimentation. Results of a workshop held at JPL on PCS integration and interoperability will be presented. Experiments will be described.