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Sample records for depletion potential odp

  1. Atmospheric chemistry of short-chain haloolefins: photochemical ozone creation potentials (POCPs), global warming potentials (GWPs), and ozone depletion potentials (ODPs).

    Science.gov (United States)

    Wallington, T J; Sulbaek Andersen, M P; Nielsen, O J

    2015-06-01

    Short-chain haloolefins are being introduced as replacements for saturated halocarbons. The unifying chemical feature of haloolefins is the presence of a CC double bond which causes the atmospheric lifetimes to be significantly shorter than for the analogous saturated compounds. We discuss the atmospheric lifetimes, photochemical ozone creation potentials (POCPs), global warming potentials (GWPs), and ozone depletion potentials (ODPs) of haloolefins. The commercially relevant short-chain haloolefins CF3CFCH2 (1234yf), trans-CF3CHCHF (1234ze(Z)), CF3CFCF2 (1216), cis-CF3CHCHCl (1233zd(Z)), and trans-CF3CHCHCl (1233zd(E)) have short atmospheric lifetimes (days to weeks), negligible POCPs, negligible GWPs, and ODPs which do not differ materially from zero. In the concentrations expected in the environment their atmospheric degradation products will have a negligible impact on ecosystems. CF3CFCH2 (1234yf), trans-CF3CHCHF (1234ze(Z)), CF3CFCF2 (1216), cis-CF3CHCHCl (1233zd(Z)), and trans-CF3CHCHCl (1233zd(E)) are environmentally acceptable. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Ozone depletion and chlorine loading potentials

    Science.gov (United States)

    Pyle, John A.; Wuebbles, Donald J.; Solomon, Susan; Zvenigorodsky, Sergei; Connell, Peter; Ko, Malcolm K. W.; Fisher, Donald A.; Stordal, Frode; Weisenstein, Debra

    1991-01-01

    The recognition of the roles of chlorine and bromine compounds in ozone depletion has led to the regulation or their source gases. Some source gases are expected to be more damaging to the ozone layer than others, so that scientific guidance regarding their relative impacts is needed for regulatory purposes. Parameters used for this purpose include the steady-state and time-dependent chlorine loading potential (CLP) and the ozone depletion potential (ODP). Chlorine loading potentials depend upon the estimated value and accuracy of atmospheric lifetimes and are subject to significant (approximately 20-50 percent) uncertainties for many gases. Ozone depletion potentials depend on the same factors, as well as the evaluation of the release of reactive chlorine and bromine from each source gas and corresponding ozone destruction within the stratosphere.

  3. Ozone Depletion Potentials of HCFC-123 and HCFC-124

    Science.gov (United States)

    Riepe, E. L.; Patten, K. O.; Wuebbles, D. J.

    2005-05-01

    The Montreal Protocol has phased out most chlorinated and brominated compounds because of their great efficiency in depleting ozone in the stratosphere. Compounds such as CHCl2CF3 (HCFC-123) and CHClFCF3 (HCFC-124) are being used in commercial refrigeration units and have much shorter atmospheric lifetimes than the chlorofluorocarbons they replace. Despite their small resulting Ozone Depletion Potentials (ODPs), these compounds are still currently expected to be eliminated under the existing Protocol, but there remain questions about finding suitable replacements that would not have other environmental effects. The HCFC-123 and HCFC-124 model-calculated atmospheric lifetimes of 1.3 years and 5.8 years are much shorter compared to the 45 years of CCl3F (CFC-11). In this study, we have reevaluated these compounds with an updated version of the UIUC two-dimensional chemical transport model and with the MOZART (version 3) three-dimensional chemical-transport model. The new version of the two-dimensional model gives ODPs of 0.012 and 0.0125 for HCFC-123 and HCFC-124, respectively. The ODP for HCFC-123 agrees well with previously reported values while the ODP for HCFC-124 is much smaller than earlier estimates. These analyses along with those from the three-dimensional modeling studies will be discussed in the presentation.

  4. Uncertainty analysis of projections of ozone-depleting substances: mixing ratios, EESC, ODPs, and GWPs

    Directory of Open Access Journals (Sweden)

    G. J. M. Velders

    2013-10-01

    Full Text Available The rates at which ozone depleting substances (ODSs are removed from the atmosphere, that is, their lifetimes, are key factors for determining the rate of ozone layer recovery in the coming decades. We present here a comprehensive uncertainty analysis of future mixing ratios of ODSs, levels of equivalent effective stratospheric chlorine (EESC, ozone depletion potentials, and global warming potentials, using, among other information, the 2013 WCRP/SPARC assessment of lifetimes of ODSs and their uncertainties. The year EESC returns to pre-1980 levels, a metric commonly used to indicate a level of recovery from ODS-induced ozone depletion, is 2048 for mid-latitudes based on the lifetimes from the SPARC assessment, which is about 2 yr later than based on the lifetimes from the WMO assessment of 2011. However, the uncertainty in this return to 1980 levels is much larger than the 2 yr change. The year EESC returns to pre-1980 levels ranges from 2039 to 2064 (95% confidence interval for mid-latitudes and 2061 to 2105 for the Antarctic spring. The primary contribution to these ranges comes from the uncertainty in the lifetimes. The earlier years of the return estimates are comparable to a hypothetical scenario in which emissions of ODSs cease in 2014. The later end of the range corresponds to a scenario containing an additional emission of about 7 Mt CFC-11-eq in 2015, which is the same as about 2 times the cumulative anthropogenic emissions of all ODSs from 2014 to 2050, or about 12 times the cumulative HCFC emissions from 2014 to 2050.

  5. Ozone Depletion Potential of CH3Br

    Science.gov (United States)

    Sander, Stanley P.; Ko, Malcolm K. W.; Sze, Nien Dak; Scott, Courtney; Rodriquez, Jose M.; Weisenstein, Debra K.

    1998-01-01

    The ozone depletion potential (ODP) of methyl bromide (CH3Br) can be determined by combining the model-calculated bromine efficiency factor (BEF) for CH3Br and its atmospheric lifetime. This paper examines how changes in several key kinetic data affect BEF. The key reactions highlighted in this study include the reaction of BrO + H02, the absorption cross section of HOBr, the absorption cross section and the photolysis products of BrON02, and the heterogeneous conversion of BrON02 to HOBR and HN03 on aerosol particles. By combining the calculated BEF with the latest estimate of 0.7 year for the atmospheric lifetime of CH3Br, the likely value of ODP for CH3Br is 0.39. The model-calculated concentration of HBr (approximately 0.3 pptv) in the lower stratosphere is substantially smaller than the reported measured value of about I pptv. Recent publications suggested models can reproduce the measured value if one assumes a yield for HBr from the reaction of BrO + OH or from the reaction of BrO + H02. Although the DeAlore et al. evaluation concluded any substantial yield of HBr from BrO + HO2 is unlikely, for completeness, we calculate the effects of these assumed yields on BEF for CH3Br. Our calculations show that the effects are minimal: practically no impact for an assumed 1.3% yield of HBr from BrO + OH and 10% smaller for an assumed 0.6% yield from BrO + H02.

  6. Emission location dependent ozone depletion potentials for very short-lived halogenated species

    Directory of Open Access Journals (Sweden)

    I. Pisso

    2010-12-01

    Full Text Available We present trajectory-based estimates of Ozone Depletion Potentials (ODPs for very short-lived halogenated source gases as a function of surface emission location. The ODPs are determined by the fraction of source gas and its degradation products which reach the stratosphere, depending primarily on tropospheric transport and chemistry, and the effect of the resulting reactive halogen in the stratosphere, which is determined by stratospheric transport and chemistry, in particular by stratospheric residence time. Reflecting the different timescales and physico-chemical processes in the troposphere and stratosphere, the estimates are based on calculation of separate ensembles of trajectories for the troposphere and stratosphere. A methodology is described by which information from the two ensembles can be combined to give the ODPs.

    The ODP estimates for a species with a fixed 20 d lifetime, representing a compound like n-propyl bromide, are presented as an example. The estimated ODPs show strong geographical and seasonal variation, particularly within the tropics. The values of the ODPs are sensitive to the inclusion of a convective parametrization in the trajectory calculations, but the relative spatial and seasonal variation is not. The results imply that ODPs are largest for emissions from south and south-east Asia during Northern Hemisphere summer and from the western Pacific during Northern Hemisphere winter. Large ODPs are also estimated for emissions throughout the tropics with non-negligible values also extending into northern mid-latitudes, particularly in the summer. These first estimates, whilst made under some simplifying assumptions, show larger ODPs for certain emission regions, particularly south Asia in NH summer, than have typically been reported by previous studies which used emissions distributed evenly over land surfaces.

  7. Ozone-depleting Substances (ODS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This site includes all of the ozone-depleting substances (ODS) recognized by the Montreal Protocol. The data include ozone depletion potentials (ODP), global warming...

  8. The ozone depletion potentials on halocarbons: Their dependence of calculation assumptions

    Science.gov (United States)

    Karol, Igor L.; Kiselev, Andrey A.

    1994-01-01

    The concept of Ozone Depletion Potential (ODP) is widely used in the evaluation of numerous halocarbons and of their replacement effects on ozone, but the methods, assumptions and conditions used in ODP calculations have not been analyzed adequately. In this paper a model study of effects on ozone of the instantaneous releases of various amounts of CH3CCl3 and of CHF2Cl (HCFC-22) for several compositions of the background atmosphere are presented, aimed at understanding connections of ODP values with the assumptions used in their calculations. To facilitate the ODP computation in numerous versions for the long time periods after their releases, the above rather short-lived gases and the one-dimensional radiative photochemical model of the global annually averaged atmospheric layer up to 50 km height are used. The variation of released gas global mass from 1 Mt to 1 Gt leads to ODP value increase with its stabilization close to the upper bound of this range in the contemporary atmosphere. The same variations are analyzed for conditions of the CFC-free atmosphere of 1960's and for the anthropogenically loaded atmosphere in the 21st century according to the known IPCC 'business as usual' scenario. Recommendations for proper ways of ODP calculations are proposed for practically important cases.

  9. Ozone Depletion Potential of CH3Br. Appendix H

    Science.gov (United States)

    Ko, Malcolm K. W.; Sze, Nien Dak; Scott, Courtney; Rodriguez, Jose M.; Weisenstein, Debra K.; Sander, Stanley P.

    1998-01-01

    The ozone depletion potential (ODP) of methyl bromide (CH3Br) can be determined by combining the model-calculated bromine efficiency factor (BEF) for CH3Br and its atmospheric lifetime. This paper examines how changes in several key kinetic data affect BEF. The key reactions highlighted in this study include the reaction of BrO + HO2, the absorption cross section of HOBr, the absorption cross section and the photolysis products of BrONO2, and the heterogeneous conversion of BrONO2 to HOBr and HNO3 on aerosol particles. By combining the calculated BEF with the latest estimate of 0.7 year for the atmospheric lifetime of CH3Br, the likely value of ODP for CH3Br is 0.39. The model-calculated concentration of HBr (approx. 0.3 pptv) in the lower stratosphere is substantially smaller than the reported measured value of about 1 pptv. Recent publications suggested models can reproduce the measured value if one assumes a yield for HBr from the reaction of BrO + OH or from the reaction of BrO + HO2. Although the evaluation concluded any substantial yield of HBr from BrO + HO2 is unlikely, for completeness, we calculate the effects of these assumed yields on BEF for CH3Br. Our calculations show that the effects are minimal: practically no impact for an assumed 1.3% yield of HBr from BrO + OH and 10% smaller for an assumed 0.6% yield from BrO + HO2.

  10. Variations in ozone depletion potentials of very short-lived substances with season and emission region

    Science.gov (United States)

    Brioude, J.; Portmann, R. W.; Daniel, J. S.; Cooper, O. R.; Frost, G. J.; Rosenlof, K. H.; Granier, C.; Ravishankara, A. R.; Montzka, S. A.; Stohl, A.

    2010-12-01

    We present a new approach for calculating the fraction of very-short lived substances (VSLS) emitted at the surface (and their degradation products) that reach the stratosphere (β) using the FLEXPART Lagrangian model. The values of β play a key role in determining the efficiency of these compounds for depleting stratospheric ozone, and are used to estimate ozone depletion potentials (ODPs) for several short-lived compounds. Values of β and ODPs of VSLSs are characterized by large regional and seasonal variability owing to the importance of convective transport. For instance, β and ODPs associated with emissions from the Indian subcontinent is an order of magnitude larger than from Europe, mid-latitude North America, or East Asia.The seasonal cycle of β is mainly driven by transport efficiency from the boundary layer into the tropical stratosphere with a minimum in winter and a maximum in summer. Variation of fraction of mass of VSLS reaching the stratosphere (β) plotted against the seasonally varying tropospheric lifetime of VSLS. Values of β are calculated for different seasons (panels) and regions of emission (color code). Also shown are the results for VSLS with predominantly photolytic loss (stars) and OH loss (circles).

  11. Three-dimensional model evaluation of the Ozone Depletion Potentials for n-propyl bromide, trichloroethylene and perchloroethylene

    Directory of Open Access Journals (Sweden)

    D. J. Wuebbles

    2010-07-01

    Full Text Available The existing solvents trichloroethylene (TCE and perchloroethylene (PCE and proposed solvent n-propyl bromide (nPB have atmospheric lifetimes from days to a few months, but contain chlorine or bromine that could affect stratospheric ozone. Several previous studies estimated the Ozone Depletion Potentials (ODPs for various assumptions for location of nPB emissions, but these studies used simplified modeling treatments. The primary purpose of this study is to reevaluate the ODP for nPB using a current-generation chemistry-transport model of the troposphere and stratosphere. For the first time, ODPs for TCE and PCE are also evaluated. Emissions representing industrial use of each compound are incorporated on land surfaces from 30° N to 60° N. The atmospheric chemical lifetime obtained for nPB is 24.7 days, similar to past literature, but the ODP is 0.0049, lower than in past studies. The derived atmospheric lifetime for TCE is 13.0 days and for PCE is 111 days. The corresponding ODPs are 0.00035 and 0.0060, respectively.

  12. FDTs for ODP

    OpenAIRE

    Bowman, Howard; Derrick, John; Linington, Peter F.; van Steen, Maarten

    1995-01-01

    This paper discusses the use and integration of formal techniques into the Open Distributed Processing (ODP) standardization initiative. The ODP reference model is a natural progression from OSI. Multiple viewpoints are used to specify complex ODP systems. Formal methods are playing an increasing role within ODP. We provide an overview of the ODP reference model, before discussing the ODP requirements on FDTs, and the role such techniques play. Finally we discuss the use of formalisms in the ...

  13. A three-dimensional model calculation of the ozone depletion potential of 1-bromopropane (1-C3H7Br)

    Science.gov (United States)

    Bridgeman, C. H.; Pyle, J. A.; Shallcross, D. E.

    2000-11-01

    A three-dimensional chemical transport model has been used to investigate factors affecting the potential impact of a short-lived bromine compound on lower stratospheric ozone. The model is used to calculate the ozone depletion potential (ODP) of 1-bromopropane employing a previously used empirical approach, which depends on the lifetime of the compound and the amount reaching the stratosphere. We show that this approach may be unsuitable for very short-lived compounds. Indeed, for a short-lived compound the definition of the lifetime itself is ambiguous. The lifetime varies with season, region of emission, and depends on the method of calculation. A series of tracer experiments reveals that the amount of bromine reaching the stratosphere, and hence the calculated ODP, can also be highly dependent on the distribution of the surface emissions. Where emissions are located solely in the equatorial region, the calculated ODP is over 3 times greater than when the emissions are centered over Europe. Vigorous convection in the tropics can lift the compound rapidly into the lower stratosphere where the bromine can be released and contribute to ozone destruction. For surface releases at higher latitudes the lifetime in the troposphere is significant compared with the time to reach the stratosphere and a smaller ODP is calculated. This highlights a problem in calculating ODPs for short-lived species. Uncertainties in the degradation mechanisms for short-lived compounds, and the subsequent fate of the degradation intermediates, add further uncertainty to calculations of their impact on the stratosphere. Additional methods need to be developed to assess their potential impact on the stratosphere.

  14. Effective Depletion Potential of Colloidal Spheres

    Institute of Scientific and Technical Information of China (English)

    LI Wei-Hua; MA Hong-Ru

    2004-01-01

    @@ A new semianalytical method, which is a combination of the density functional theory with Rosenfeld density functional and the Ornstein-Zernike equation, is proposed for the calculation of the effective depletion potentials between a pair of big spheres immersed in a small hard sphere fluid. The calculated results are almost identical to the integral equation method with the Percus-Yevick approximation, and are also in agreement well with the Monte Carlo simulation results.

  15. Halocarbon ozone depletion and global warming potentials

    Science.gov (United States)

    Cox, Richard A.; Wuebbles, D.; Atkinson, R.; Connell, Peter S.; Dorn, H. P.; Derudder, A.; Derwent, Richard G.; Fehsenfeld, F. C.; Fisher, D.; Isaksen, Ivar S. A.

    1990-01-01

    Concern over the global environmental consequences of fully halogenated chlorofluorocarbons (CFCs) has created a need to determine the potential impacts of other halogenated organic compounds on stratospheric ozone and climate. The CFCs, which do not contain an H atom, are not oxidized or photolyzed in the troposphere. These compounds are transported into the stratosphere where they decompose and can lead to chlorine catalyzed ozone depletion. The hydrochlorofluorocarbons (HCFCs or HFCs), in particular those proposed as substitutes for CFCs, contain at least one hydrogen atom in the molecule, which confers on these compounds a much greater sensitivity toward oxidation by hydroxyl radicals in the troposphere, resulting in much shorter atmospheric lifetimes than CFCs, and consequently lower potential for depleting ozone. The available information is reviewed which relates to the lifetime of these compounds (HCFCs and HFCs) in the troposphere, and up-to-date assessments are reported of the potential relative effects of CFCs, HCFCs, HFCs, and halons on stratospheric ozone and global climate (through 'greenhouse' global warming).

  16. Atmospheric lifetimes and Ozone Depletion Potentials of trans-1-chloro-3,3,3-trifluoropropylene and trans-1,2-dichloroethylene in a three-dimensional model

    Science.gov (United States)

    Patten, K. O.; Wuebbles, D. J.

    2010-11-01

    The chloroalkenes trans-1-chloro-3,3,3-trifluoropropylene (tCFP) and trans-1,2-dichloroethylene (tDCE) have been proposed as candidate replacements for other compounds in current use that cause concerns regarding potential environmental effects including destruction of stratospheric ozone. Because tCFP and tDCE contain chlorine atoms, the effects of these short-lived compounds on stratospheric ozone must be established. In this study, we derive the atmospheric lifetimes and Ozone Depletion Potentials (ODPs) for tCFP and for tDCE assuming emissions from land surfaces at latitudes 30° N to 60° N using the MOZART 3 three-dimensional model of atmospheric chemistry and physics. 53% of the ozone loss due to tCFP and 98% of the ozone loss due to tDCE take place in the troposphere, rather than in the stratosphere as generally expected from longer-lived chlorocarbons. The atmospheric lifetime of tCFP against chemical reaction is 40.4 days, and its ODP is quite small at 0.00034. The tDCE atmospheric lifetime is 12.7 days, and its ODP is 0.00024, which is the lowest ODP found for any chlorocarbon we have studied. Our study suggests that chlorine from tCFP and tDCE are unlikely to affect ozone at quantities likely to be emitted to the atmosphere.

  17. Atmospheric lifetimes and Ozone Depletion Potentials of trans-1-chloro-3,3,3-trifluoropropylene and trans-1,2-dichloroethylene in a three-dimensional model

    Directory of Open Access Journals (Sweden)

    K. O. Patten

    2010-11-01

    Full Text Available The chloroalkenes trans-1-chloro-3,3,3-trifluoropropylene (tCFP and trans-1,2-dichloroethylene (tDCE have been proposed as candidate replacements for other compounds in current use that cause concerns regarding potential environmental effects including destruction of stratospheric ozone. Because tCFP and tDCE contain chlorine atoms, the effects of these short-lived compounds on stratospheric ozone must be established. In this study, we derive the atmospheric lifetimes and Ozone Depletion Potentials (ODPs for tCFP and for tDCE assuming emissions from land surfaces at latitudes 30° N to 60° N using the MOZART 3 three-dimensional model of atmospheric chemistry and physics. 53% of the ozone loss due to tCFP and 98% of the ozone loss due to tDCE take place in the troposphere, rather than in the stratosphere as generally expected from longer-lived chlorocarbons. The atmospheric lifetime of tCFP against chemical reaction is 40.4 days, and its ODP is quite small at 0.00034. The tDCE atmospheric lifetime is 12.7 days, and its ODP is 0.00024, which is the lowest ODP found for any chlorocarbon we have studied. Our study suggests that chlorine from tCFP and tDCE are unlikely to affect ozone at quantities likely to be emitted to the atmosphere.

  18. The depletion potential in one, two and three dimensions

    Indian Academy of Sciences (India)

    R Roth; P-M König

    2005-06-01

    We study the behavior of the depletion potential in binary mixtures of hard particles in one, two, and three dimensions within the framework of a general theory for depletion potential using density functional theory. By doing so we extend earlier studies of the depletion potential in three dimensions to the cases of = 1 and 2 about which little is known, despite their importance for experiments. We also verify scaling relations between depletion potentials in sphere–sphere and wall–sphere geometries in = 3 and in disk–disk and wall–disk geometries in = 2, which originate from geometrical considerations.

  19. Emission quantification of refrigerant CFCs, HCFCs and HFCs in megacity Lahore (Pakistan) and contributed ODPs and GWPs

    Indian Academy of Sciences (India)

    Zia Ul-Haq; Muhammad Ali; Syeda Adila Batool; Salman Tariq; Zarmina Qayyum

    2016-08-01

    An integrated assessment of emissions of some important refrigerant ozone depleting substances (ODSs) (CFC-11, CFC-12, HCFC-141b and HFC-134a) and their contributed ozone depletion potentials (ODPs) and global warming potentials (GWPs) have been made in the megacity Lahore (Pakistan) for the periodfrom 2005 to 2013. During the production of 6.488 million refrigerator units, the cumulative estimated emissions of CFC-11, CFC-12, HCFC-141b and HFC-134a were 129.7, 6.8, 1257 and 104 mega grams (1 Mg = 106 grams). The estimated GWP (CO2-eq) and ODP (CFC 11-eq) associated with productionphase emissions of these four gases were 616.07, 73.52, 910.96, and 87.36 kilotonnes, and 129.7, 6.8, 139.4, and 0 tonnes, respectively. ODP of HFC-134a is considered to be zero. In addition, the repair and maintenance of 81.2 thousand units resulted in 10.8 Mg emissions of CFC-12 with 10.8 tonnes ODP(CFC11-eq) and 117,802 tonnes GWP (CO2-eq) that were higher than the HFC-134a emissions recorded at 4.3 Mg causing 4563 tonnes GWP(CO2-eq). A decrease in ODP (CFC 11-eq) and GWP (CO2-eq) at the rate of −8.3% and −8.2% per year is observed to be contributed by all the selected ODSs during the study period.

  20. Emission quantification of refrigerant CFCs, HCFCs and HFCs in megacity Lahore (Pakistan) and contributed ODPs and GWPs

    Science.gov (United States)

    Ul-Haq, Zia; Ali, Muhammad; Batool, Syeda Adila; Tariq, Salman; Qayyum, Zarmina

    2016-08-01

    An integrated assessment of emissions of some important refrigerant ozone depleting substances (ODSs) (CFC-11, CFC-12, HCFC-141b and HFC-134a) and their contributed ozone depletion potentials (ODPs) and global warming potentials (GWPs) have been made in the megacity Lahore (Pakistan) for the period from 2005 to 2013. During the production of 6.488 million refrigerator units, the cumulative estimated emissions of CFC-11, CFC-12, HCFC-141b and HFC-134a were 129.7, 6.8, 1257 and 104 mega grams (1 Mg = 106 grams). The estimated GWP (CO2-eq) and ODP (CFC 11-eq) associated with production phase emissions of these four gases were 616.07, 73.52, 910.96, and 87.36 kilotonnes, and 129.7, 6.8, 139.4, and 0 tonnes, respectively. ODP of HFC-134a is considered to be zero. In addition, the repair and maintenance of 81.2 thousand units resulted in 10.8 Mg emissions of CFC-12 with 10.8 tonnes ODP(CFC 11-eq) and 117,802 tonnes GWP (CO2-eq) that were higher than the HFC-134a emissions recorded at 4.3 Mg causing 4563 tonnes GWP(CO2-eq). A decrease in ODP (CFC 11-eq) and GWP (CO2-eq) at the rate of -8.3% and -8.2% per year is observed to be contributed by all the selected ODSs during the study period.

  1. The Abiotic Depletion Potential: Background, Updates, and Future

    Directory of Open Access Journals (Sweden)

    Lauran van Oers

    2016-03-01

    Full Text Available Depletion of abiotic resources is a much disputed impact category in life cycle assessment (LCA. The reason is that the problem can be defined in different ways. Furthermore, within a specified problem definition, many choices can still be made regarding which parameters to include in the characterization model and which data to use. This article gives an overview of the problem definition and the choices that have been made when defining the abiotic depletion potentials (ADPs for a characterization model for abiotic resource depletion in LCA. Updates of the ADPs since 2002 are also briefly discussed. Finally, some possible new developments of the impact category of abiotic resource depletion are suggested, such as redefining the depletion problem as a dilution problem. This means taking the reserves in the environment and the economy into account in the reserve parameter and using leakage from the economy, instead of extraction rate, as a dilution parameter.

  2. Observation-based assessment of stratospheric fractional release, lifetimes, and ozone depletion potentials of ten important source gases

    Directory of Open Access Journals (Sweden)

    J. C. Laube

    2013-03-01

    Full Text Available Estimates of the recovery time of stratospheric ozone heavily rely on the exact knowledge of the processes that lead to the decomposition of the relevant halogenated source gases. Crucial parameters in this context are fractional release factors (FRFs as well as stratospheric lifetimes and ozone depletion potentials (ODPs. We here present data from the analysis of air samples collected between 2009 and 2011 on board research aircraft flying in the mid- and high-latitude stratosphere and infer the above-mentioned parameters for ten major source gases: CFCl3 (CFC-11, CF2Cl2 (CFC-12, CF2ClCFCl2 (CFC-113, CCl4 (carbon tetrachloride, CH3CCl3 (methyl chloroform, CHF2Cl (HCFC-22, CH3CFCl2 (HCFC-141b, CH3CF2Cl (HCFC-142b, CF2ClBr (H-1211, and CF3Br (H-1301. The inferred correlations of their FRFs with mean ages of air reveal less decomposition as compared to previous studies for most compounds. When using the calculated set of FRFs to infer equivalent stratospheric chlorine, we find a reduction of more than 20% as compared to the values inferred in the most recent Scientific Assessment of Ozone Depletion by the World Meteorological Organisation (WMO, 2011. We also note that FRFs and their correlations with mean age are not generally time-independent as often assumed. The stratospheric lifetimes were calculated relative to that of CFC-11. Within our uncertainties the ratios between stratospheric lifetimes inferred here agree with the values in recent WMO reports except for CFC-11, CFC-12 and CH3CCl3. Finally, we calculate lower ODPs than recommended by WMO for six out of ten compounds, with changes most pronounced for the three HCFCs. Collectively these newly calculated values may have important implications for the severity and recovery time of stratospheric ozone loss.

  3. Depletion potential in colloidal mixtures of hard spheres and platelets.

    Science.gov (United States)

    Harnau, L; Dietrich, S

    2004-05-01

    The depletion potential between two hard spheres in a solvent of thin hard disclike platelets is investigated by using either the Derjaguin approximation or density functional theory. Particular attention is paid to the density dependence of the depletion potential. A second-order virial approximation is applied, which yields nearly exact results for the bulk properties of the hard-platelet fluid at densities two times smaller than the density of the isotropic fluid at isotropic-nematic phase coexistence. As the platelet density increases, the attractive primary minimum of the depletion potential deepens and an additional small repulsive barrier at larger sphere separations develops. Upon decreasing the ratio of the radius of the spheres and the platelets, the primary minimum diminishes and the position of the small repulsive barrier shifts to smaller values of the sphere separation.

  4. Depletion potentials in colloidal mixtures of hard spheres and rods.

    Science.gov (United States)

    Li, Weihua; Yang, Tao; Ma, Hong-ru

    2008-01-28

    The depletion potential between a hard sphere and a planar hard wall, or two hard spheres, imposed by suspended rigid spherocylindrical rods is computed by the acceptance ratio method through the application of Monte Carlo simulation. The accurate results and ideal-gas approximation results of the depletion potential are determined with the acceptance ratio method in our simulations. For comparison, the depletion potentials are also studied by using both the density functional theory and Derjaguin approximations. The density profile as a function of positions and orientations of rods, used in the density functional theory, is calculated by Monte Carlo simulation. The potential obtained by the acceptance ratio method is in good agreement with that of density functional theory under the ideal-gas approximation. The comparison between our results and those of other theories suggests that the acceptance ratio method is the only efficient method used to compute the depletion potential induced by nonspherical colloids with the volume fraction beyond the ideal-gas approximation.

  5. Depletion potential in hard-sphere mixtures: theory and applications

    Science.gov (United States)

    Roth; Evans; Dietrich

    2000-10-01

    We present a versatile density functional approach (DFT) for calculating the depletion potential in general fluid mixtures. For the standard situation of a single big particle immersed in a sea of small particles near a fixed object, the system is regarded as an inhomogeneous binary mixture of big and small particles in the external field of the fixed object, and the limit of vanishing density of the big species, rho(b)-->0, is taken explicitly. In this limit our approach requires only the equilibrium density profile of a one-component fluid of small particles in the field of the fixed object, and a knowledge of the density independent weight functions which characterize the mixture functional. Thus, for a big particle near a planar wall or a cylinder or another fixed big particle, the relevant density profiles are functions of a single variable, which avoids the numerical complications inherent in brute force DFT. We implement our approach for additive hard-sphere mixtures, comparing our results with computer simulations for the depletion potential of a big sphere of radius R(b) in a sea of small spheres of radius R(s) near (i) a planar hard wall, and (ii) another big sphere. In both cases our results are accurate for size ratios s=R(s)/R(b) as small as 0.1, and for packing fractions of the small spheres eta(s) as large as 0.3; these are the most extreme situations for which reliable simulation data are currently available. Our approach satisfies several consistency requirements, and the resulting depletion potentials incorporate the correct damped oscillatory decay at large separations of the big particles or of the big particle and the wall. By investigating the depletion potential for high size asymmetries we assess the regime of validity of the well-known Derjaguin approximation for hard-sphere mixtures and argue that this fails, even for very small size ratios s, for all but the smallest values of eta(s) where the depletion potential reduces to the Asakura

  6. New methodology for Ozone Depletion Potentials of short-lived compounds: n-Propyl bromide as an example

    Science.gov (United States)

    Wuebbles, Donald J.; Patten, Kenneth O.; Johnson, Matthew T.; Kotamarthi, Rao

    2001-07-01

    A number of the compounds proposed as replacements for substances controlled under the Montreal Protocol have extremely short atmospheric lifetimes, on the order of days to a few months. An important example is n-propyl bromide (also referred to as 1-bromopropane, CH2BrCH2CH3 or simplified as 1-C3H7Br or nPB). This compound, useful as a solvent, has an atmospheric lifetime of less than 20 days due to its reaction with hydroxyl. Because nPB contains bromine, any amount reaching the stratosphere has the potential to affect concentrations of stratospheric ozone. The definition of Ozone Depletion Potentials (ODP) needs to be modified for such short-lived compounds to account for the location and timing of emissions. It is not adequate to treat these chemicals as if they were uniformly emitted at all latitudes and longitudes as normally done for longer-lived gases. Thus, for short-lived compounds, policymakers will need a table of ODP values instead of the single value generally provided in past studies. This study uses the MOZART2 three-dimensional chemical-transport model in combination with studies with our less computationally expensive two-dimensional model to examine potential effects of nPB on stratospheric ozone. Multiple facets of this study examine key questions regarding the amount of bromine reaching the stratosphere following emission of nPB. Our most significant findings from this study for the purposes of short-lived replacement compound ozone effects are summarized as follows. The degradation of nPB produces a significant quantity of bromoacetone which increases the amount of bromine transported to the stratosphere due to nPB. However, much of that effect is not due to bromoacetone itself, but instead to inorganic bromine which is produced from tropospheric oxidation of nPB, bromoacetone, and other degradation products and is transported above the dry and wet deposition processes of the model. The MOZART2 nPB results indicate a minimal correction of the

  7. DEPLETION POTENTIAL OF COLLOIDS:A DIRECT SIMULATION STUDY

    Institute of Scientific and Technical Information of China (English)

    LI; Wei-hua(

    2001-01-01

    [1]Asakura S, Oosawa F. Surface tension of high-poly-mer solution [J]. J Chem Phys, 1954, 22: 1255~ 1255.[2]Ye X, Narayanan T, Tong P, et al. Depletion interactions in colloid-polymer mixtures [J]. Phys Rev E, 1996, 54: 6500~6510.[3]Kaplan P D, Faucheux L P, Libchaber A J. Direct observation of the entropic potential in a binary suspension [J]. Phys Rev Lett, 1994, 73: 2793~2796.[4]Ohshima Y N, Sakagami H, Okumoto K, et al. Direct measurement of infinite simal depletion force in a colloid-polymer mixture by laser radiation pressure [J]. Phys Rev Lett, 1997, 78: 3963~3966.[5]Dinsmore A D, Yodh A G, Pine D J. Entropic control particle motion using passive surface microstructures [J]. Nature (London), 1996, 383: 239~242.[6]Dinsmore A D, Wong D T, Nelson P, et al. Hard spheres in vecicles: curvature-induced forces and particle-induced curvature [J]. Phys Rev Lett, 1998, 80: 409~412.[7]Gtzelmann B, Evans R, Dietrich S. Depletion forces in fluids [J]. Phys Rev E, 1998, 57: 6785~6800.[8]Miao Y, Cates M E, Lekkerkerker H N W. Depletion force in colloidal systems [J]. Physica A, 1995, 222: 10~24.[9]Biben J, Bladon P, Frenkel D. Depletion effects in binary hard-sphere fluids [J]. J Phys: Condens Matter, 1996, 8: 10799~10821.[10]Dickman R, Attard P, Simonian V. Entropic forces in binary hard sphere mixture: Theory and simulation [J]. J Chem Phys, 1997, 107: 205~213.[11]Bennett C H. Efficient estimation of free energy differences from Monte Carlo data [J]. J Comput Phys, 1976, 22: 245~268; see also Allen M P, Tildesley D J. Computer Simulation of Liquids (Chap.7) [M]. Oxford: Clarendon Press. 1994.

  8. Horizontal spacing, depletion, and infill potential in the Austin chalk

    Energy Technology Data Exchange (ETDEWEB)

    Kyte, D.G.; Meehan, D.N.

    1996-12-31

    Estimated ultimate recoveries on a barrels per acre basis for Austin chalk wells were discussed. The study showed that the maximum six months consecutive production through the life of the well can be used to estimate ultimate recovery in horizontally drilled reservoirs. A statistical approach was used to help identify where the Austin chalk has been overdrilled and areas where infill potential exists. The barrels per acre data were analyzed by a method known as `moving domain`. This procedure involves stepping through the reservoir well by well and looking at it with respect to its nearest neighbors. To analyze for depletion, barrels per acre is compared to date of first production for groups of wells in an area, looking for declining values with time. Areas showing no evidence of depletion and having good recoveries are further studied for infill potential. By comparing effective densities in areas which are not yet being fully drained, an optimum spacing between wells can be determined for horizontal wells in a fractured chalk reservoir. An artificial neural network can also be used to provide qualitative predictions of well performance in developed reservoirs. 6 refs., 15 figs.

  9. Fully depleted CMOS pixel sensor development and potential applications

    Energy Technology Data Exchange (ETDEWEB)

    Baudot, J.; Kachel, M. [Universite de Strasbourg, IPHC, 23 rue du Loess 67037 Strasbourg (France); CNRS, UMR7178, 67037 Strasbourg (France)

    2015-07-01

    CMOS pixel sensors are often opposed to hybrid pixel sensors due to their very different sensitive layer. In standard CMOS imaging processes, a thin (about 20 μm) low resistivity epitaxial layer acts as the sensitive volume and charge collection is mostly driven by thermal agitation. In contrast, the so-called hybrid pixel technology exploits a thick (typically 300 μm) silicon sensor with high resistivity allowing for the depletion of this volume, hence charges drift toward collecting electrodes. But this difference is fading away with the recent availability of some CMOS imaging processes based on a relatively thick (about 50 μm) high resistivity epitaxial layer which allows for full depletion. This evolution extents the range of applications for CMOS pixel sensors where their known assets, high sensitivity and granularity combined with embedded signal treatment, could potentially foster breakthrough in detection performances for specific scientific instruments. One such domain is the Xray detection for soft energies, typically below 10 keV, where the thin sensitive layer was previously severely impeding CMOS sensor usage. Another application becoming realistic for CMOS sensors, is the detection in environment with a high fluence of non-ionizing radiation, such as hadron colliders. However, when considering highly demanding applications, it is still to be proven that micro-circuits required to uniformly deplete the sensor at the pixel level, do not mitigate the sensitivity and efficiency required. Prototype sensors in two different technologies with resistivity higher than 1 kΩ, sensitive layer between 40 and 50 μm and featuring pixel pitch in the range 25 to 50 μm, have been designed and fabricated. Various biasing architectures were adopted to reach full depletion with only a few volts. Laboratory investigations with three types of sources (X-rays, β-rays and infrared light) demonstrated the validity of the approach with respect to depletion, keeping a

  10. Predatory fish depletion and recovery potential on Caribbean reefs

    Science.gov (United States)

    Valdivia, Abel; Cox, Courtney Ellen; Bruno, John Francis

    2017-01-01

    The natural, prehuman abundance of most large predators is unknown because of the lack of historical data and a limited understanding of the natural factors that control their populations. Determining the supportable predator biomass at a given location (that is, the predator carrying capacity) would help managers to optimize protection and would provide site-specific recovery goals. We assess the relationship between predatory reef fish biomass and several anthropogenic and environmental variables at 39 reefs across the Caribbean to (i) estimate their roles determining local predator biomass and (ii) determine site-specific recovery potential if fishing was eliminated. We show that predatory reef fish biomass tends to be higher in marine reserves but is strongly negatively related to human activities, especially coastal development. However, human activities and natural factors, including reef complexity and prey abundance, explain more than 50% of the spatial variation in predator biomass. Comparing site-specific predator carrying capacities to field observations, we infer that current predatory reef fish biomass is 60 to 90% lower than the potential supportable biomass in most sites, even within most marine reserves. We also found that the scope for recovery varies among reefs by at least an order of magnitude. This suggests that we could underestimate unfished biomass at sites that provide ideal conditions for predators or greatly overestimate that of seemingly predator-depleted sites that may have never supported large predator populations because of suboptimal environmental conditions. PMID:28275730

  11. DEPLETION POTENTIAL OF COLLOIDS:A DIRECT SIMULATION STUDY

    Institute of Scientific and Technical Information of China (English)

    李卫华; 薛松; 马红孺

    2001-01-01

    The depletion interaction between abig sphere and a hard wall and between two big hard spheres in a hard sphere colloidal sytem was studied by the Monte Carlo method.Direct simulation of free energy difference was performed by means of the Acceptance Ratio Method (ARM).

  12. The very short-lived ozone depleting substance CHBr3 (bromoform): Revised UV absorption spectrum, atmospheric lifetime and ozone depletion potential

    Science.gov (United States)

    Papanastasiou, Dimitrios K.; McKeen, Stuart A.; Burkholder, James B.

    2014-05-01

    more pronounced as wavelength increases and temperature decreases. The source of this discrepancy is further discussed. A parameterization of the CHBr3 UV spectrum for use in atmospheric models is developed and illustrative photolysis rate calculations are presented to highlight the impact of the revised σ(Λ,T) values on its calculated local lifetimes. For instance, CHBr3 atmospheric photolysis rate in the tropical region obtained with the present spectral data was found to be 10-15% lower (longer lifetime) than that obtained using the currently recommended values. Moreover, seasonally dependent ozone depletion potentials (ODPs) for CHBr3 emitted in the Indian sub-continent were calculated using the semi-empirical relationship of Brioude et al. (Brioude et al., Geophys. Res. Lett., 37, L19804, doi: 10.1029/2010GL044856, 2010) to evaluate the impact of the present results on stratospheric ozone. In conclusion, the present study reports improved UV absorption cross section data for the short-lived ozone depleting substance CHBr3, which are a result of high quality measurements and a thorough investigation of possible sources of systematic error. The CHBr3 UV cross section data, from this study, combined with OH kinetic data enables more accurate model predictions of stratospheric bromine loading and its impact on stratospheric ozone.

  13. Scientific assessment of ozone depletion: 1991

    Science.gov (United States)

    1991-01-01

    Over the past few years, there have been highly significant advances in the understanding of the impact of human activities on the Earth's stratospheric ozone layer and the influence of changes in chemical composition of the radiative balance of the climate system. Specifically, since the last international scientific review (1989), there have been five major advances: (1) global ozone decreases; (2) polar ozone; (3) ozone and industrial halocarbons; (4) ozone and climate relations; and (5) ozone depletion potentials (ODP's) and global warming potentials (GWP's). These topics and others are discussed.

  14. Ozone Depletion by Hydrofluorocarbons

    Science.gov (United States)

    Hurwitz, M.; Fleming, E. L.; Newman, P. A.; Li, F.; Mlawer, E. J.; Cady-Pereira, K. E.; Bailey, R.

    2015-12-01

    Hydrofluorocarbons (HFCs) are second-generation replacements for the chlorofluorocarbons (CFCs), halons and other substances that caused the 'ozone hole'. Atmospheric concentrations of HFCs are projected to increase dramatically in the coming decades. Coupled chemistry-climate simulations forced by these projections show that HFCs will impact the global atmosphere in 2050. As strong radiative forcers, HFCs modulate atmospheric temperature, thereby changing ozone-destroying catalytic cycles and enhancing the stratospheric circulation. These changes lead to a weak depletion of stratospheric ozone. Sensitivity simulations with the NASA Goddard Space Flight Center (GSFC) 2D model show that HFC-125 is the most important contributor to atmospheric change in 2050, as compared with HFC-23, HFC-32, HFC-134a and HFC-143a. Incorporating the interactions between chemistry, radiation and dynamics, for a likely 2050 climate, ozone depletion potentials (ODPs) for HFCs range from 4.3x10-4 to 3.5x10-2; previously HFCs were assumed to have negligible ODPs since these species lack chlorine or bromine atoms. The ozone impacts of HFCs are further investigated with the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM). The GEOSCCM is a three-dimensional, fully coupled ocean-atmosphere model with interactive stratospheric chemistry. Sensitivity simulations in which CO2, CFC-11 and HCFC-22 are enhanced individually are used as proxies for the atmospheric response to the HFC concentrations expected by the mid-21st century. Sensitivity simulations provide quantitative estimates of the impacts of these greenhouse gases on global total ozone, and can be used to assess their effects on the recovery of Antarctic ozone.

  15. Monte Carlo methods for estimating depletion potentials in highly size-asymmetrical hard sphere mixtures.

    Science.gov (United States)

    Ashton, D J; Sánchez-Gil, V; Wilding, N B

    2013-10-14

    We investigate Monte Carlo simulation strategies for determining the effective ("depletion") potential between a pair of hard spheres immersed in a dense sea of much smaller hard spheres. Two routes to the depletion potential are considered. The first is based on estimates of the insertion probability of one big sphere in the presence of the other; we describe and compare three such methods. The second route exploits collective (cluster) updating to sample the depletion potential as a function of the separation of the big particles; we describe two such methods. For both routes, we find that the sampling efficiency at high densities of small particles can be enhanced considerably by exploiting "geometrical shortcuts" that focus the computational effort on a subset of small particles. All the methods we describe are readily extendable to particles interacting via arbitrary potentials.

  16. Verifying ODP trader function by using Event B

    Directory of Open Access Journals (Sweden)

    Belhaj Hafid

    2010-07-01

    Full Text Available In order to support interoperability in open distributed systems, an information service is needed that can provide dynamic knowledge about available service providers. Such a service is Trading function, identified by Basic Reference Model of Open Distributed Processing (RM ODP. RM ODP is a joint effort of ISO and ITU?T. Within the standardization of RM ODP, Trading function is developed as a component standard. The use of formal methods in the design process of ODP systems is explicitly required. Currently there are no formal specifications of ODP concepts which are widely accepted. One interesting question concerns the suitability of event B for their use in ODP. In this paper, the use of event B for verifying ODP is investigated and evaluated. The ODP trader is chosen as case of study because it appears as a first main application of ODP.

  17. A Critical Assessment of the Resource Depletion Potential of Current and Future Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Jens F. Peters

    2016-12-01

    Full Text Available Resource depletion aspects are repeatedly used as an argument for a shift towards new battery technologies. However, whether serious shortages due to the increased demand for traction and stationary batteries can actually be expected is subject to an ongoing discussion. In order to identify the principal drivers of resource depletion for battery production, we assess different lithium-ion battery types and a new lithium-free battery technology (sodium-ion under this aspect, applying different assessment methodologies. The findings show that very different results are obtained with existing impact assessment methodologies, which hinders clear interpretation. While cobalt, nickel and copper can generally be considered as critical metals, the magnitude of their depletion impacts in comparison with that of other battery materials like lithium, aluminum or manganese differs substantially. A high importance is also found for indirect resource depletion effects caused by the co-extraction of metals from mixed ores. Remarkably, the resource depletion potential per kg of produced battery is driven only partially by the electrode materials and thus depends comparably little on the battery chemistry itself. One of the key drivers for resource depletion seems to be the metals (and co-products in electronic parts required for the battery management system, a component rather independent from the actual battery chemistry. However, when assessing the batteries on a capacity basis (per kWh storage capacity, a high-energy density also turns out to be relevant, since it reduces the mass of battery required for providing one kWh, and thus the associated resource depletion impacts.

  18. 1,2-Dichlorohexafluoro-Cyclobutane (1,2-c-C4F6Cl2, R-316c) a Potent Ozone Depleting Substance and Greenhouse Gas: Atmospheric Loss Processes, Lifetimes, and Ozone Depletion and Global Warming Potentials for the (E) and (Z) stereoisomers

    Science.gov (United States)

    Papadimitriou, Vassileios C.; McGillen, Max R.; Smith, Shona C.; Jubb, Aaron M.; Portmann, Robert W.; Hall, Bradley D.; Fleming, Eric L.; Jackman, Charles H.; Burkholder, James B.

    2013-01-01

    The atmospheric processing of (E)- and (Z)-1,2-dichlorohexafluorocyclobutane (1,2-c-C4F6Cl2, R-316c) was examined in this work as the ozone depleting (ODP) and global warming (GWP) potentials of this proposed replacement compound are presently unknown. The predominant atmospheric loss processes and infrared absorption spectra of the R-316c isomers were measured to provide a basis to evaluate their atmospheric lifetimes and, thus, ODPs and GWPs. UV absorption spectra were measured between 184.95 to 230 nm at temperatures between 214 and 296 K and a parametrization for use in atmospheric modeling is presented. The Cl atom quantum yield in the 193 nm photolysis of R- 316c was measured to be 1.90 +/- 0.27. Hexafluorocyclobutene (c-C4F6) was determined to be a photolysis co-product with molar yields of 0.7 and 1.0 (+/-10%) for (E)- and (Z)-R-316c, respectively. The 296 K total rate coefficient for the O(1D) + R-316c reaction, i.e., O(1D) loss, was measured to be (1.56 +/- 0.11) × 10(exp -10)cu cm/ molecule/s and the reactive rate coefficient, i.e., R-316c loss, was measured to be (1.36 +/- 0.20) × 10(exp -10)cu cm/molecule/s corresponding to a approx. 88% reactive yield. Rate coefficient upper-limits for the OH and O3 reaction with R-316c were determined to be global annually averaged lifetimes for the (E)- and (Z)-R-316c isomers were calculated using a 2-D atmospheric model to be 74.6 +/- 3 and 114.1 +/-10 years, respectively, where the estimated uncertainties are due solely to the uncertainty in the UV absorption spectra. Stratospheric photolysis is the predominant atmospheric loss process for both isomers with the O(1D) reaction making a minor, approx. 2% for the (E) isomer and 7% for the (Z) isomer, contribution to the total atmospheric loss. Ozone depletion potentials for (E)- and (Z)-R-316c were calculated using the 2-D model to be 0.46 and 0.54, respectively. Infrared absorption spectra for (E)- and (Z)-R-316c were measured at 296 K and used to estimate their

  19. Ozone depletion, paradigms, and politics

    Energy Technology Data Exchange (ETDEWEB)

    Iman, R.L.

    1993-10-01

    The destruction of the Earth`s protective ozone layer is a prime environmental concern. Industry has responded to this environmental problem by: implementing conservation techniques to reduce the emission of ozone-depleting chemicals (ODCs); using alternative cleaning solvents that have lower ozone depletion potentials (ODPs); developing new, non-ozone-depleting solvents, such as terpenes; and developing low-residue soldering processes. This paper presents an overview of a joint testing program at Sandia and Motorola to evaluate a low-residue (no-clean) soldering process for printed wiring boards (PWBs). Such processes are in widespread use in commercial applications because they eliminate the cleaning operation. The goal of this testing program was to develop a data base that could be used to support changes in the mil-specs. In addition, a joint task force involving industry and the military has been formed to conduct a follow-up evaluation of low-residue processes that encompass the concerns of the tri-services. The goal of the task force is to gain final approval of the low-residue technology for use in military applications.

  20. On the age of stratospheric air and ozone depletion potentials in polar regions

    Science.gov (United States)

    Pollock, W. H.; Heidt, L. E.; Lueb, R. A.; Vedder, J. F.; Mills, M. J.; Solomon, S.

    1992-01-01

    Observations of the nearly inert, man-made chlorofluorocarbon CFC-115 obtained during January 1989 are used to infer the age of air in the lower stratosphere. These observations together with estimated release rates suggest an average age of high-latitude air at pressure altitudes near 17-21 km of about 3 to 5 yr. This information is used together with direct measurements of HCFC-22, HCFC-142b, CH3Br, H-1301, H-1211, and H-2402 to examine the fractional dissociation of these species within the Arctic polar lower stratosphere compared to that of CFC-11 and hence to estimate their local ozone depletion potentials in this region. It is shown that these HCFCs are much less efficiently dissociated within the stratosphere than CFC-11, lowering their ozone depletion potentials to only about 30-40 percent of their chlorine loading potentials. In contrast, the observations of CH3Br and the Halons considered confirm that they are rapidly dissociated within the stratosphere, with important implications for their ozone depletion potentials.

  1. The potential for calcium depletion in forest ecosystems of southeastern United States: Review and analysis

    Science.gov (United States)

    Huntington, Thomas G.

    2000-06-01

    Biogeochemical mass balance assessments of calcium status in southeastern forests indicate that losses through harvesting and soil leaching often exceed inputs from atmospheric deposition and weathering. Many forest soils of the southeastern United States are particularly sensitive because these soils and the underlying saprolite from which these soils are derived are largely depleted of weatherable calcium. At most of the intensively studied sites in the southeastern United States, it is estimated that calcium depletion has already reduced or will likely reduce exchangeable soil calcium reserves to less than the estimated requirement for a merchantable forest stand in 150 years or less. At most sites, calcium uptake into merchantable wood equals or exceeds soil leaching losses. Chronic atmospheric deposition of sulfate and nitrate and declining atmospheric deposition of calcium are likely to accelerate calcium depletion. The southeastern U.S. regional distribution of soil calcium pools and calcium fluxes (deposition and uptake in merchantable wood) indicates that the depletion status of the intensively studied sites is representative of a substantially larger area. Where weathering inputs are insufficient to replace leaching and uptake losses, there is a potential for a regional problem in forest nutrition over the long term.

  2. Potential hazards of compressed air energy storage in depleted natural gas reservoirs.

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Paul W.; Grubelich, Mark Charles; Bauer, Stephen J.

    2011-09-01

    This report is a preliminary assessment of the ignition and explosion potential in a depleted hydrocarbon reservoir from air cycling associated with compressed air energy storage (CAES) in geologic media. The study identifies issues associated with this phenomenon as well as possible mitigating measures that should be considered. Compressed air energy storage (CAES) in geologic media has been proposed to help supplement renewable energy sources (e.g., wind and solar) by providing a means to store energy when excess energy is available, and to provide an energy source during non-productive or low productivity renewable energy time periods. Presently, salt caverns represent the only proven underground storage used for CAES. Depleted natural gas reservoirs represent another potential underground storage vessel for CAES because they have demonstrated their container function and may have the requisite porosity and permeability; however reservoirs have yet to be demonstrated as a functional/operational storage media for compressed air. Specifically, air introduced into a depleted natural gas reservoir presents a situation where an ignition and explosion potential may exist. This report presents the results of an initial study identifying issues associated with this phenomena as well as possible mitigating measures that should be considered.

  3. Potential hazards of compressed air energy storage in depleted natural gas reservoirs.

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Paul W.; Grubelich, Mark Charles; Bauer, Stephen J.

    2011-09-01

    This report is a preliminary assessment of the ignition and explosion potential in a depleted hydrocarbon reservoir from air cycling associated with compressed air energy storage (CAES) in geologic media. The study identifies issues associated with this phenomenon as well as possible mitigating measures that should be considered. Compressed air energy storage (CAES) in geologic media has been proposed to help supplement renewable energy sources (e.g., wind and solar) by providing a means to store energy when excess energy is available, and to provide an energy source during non-productive or low productivity renewable energy time periods. Presently, salt caverns represent the only proven underground storage used for CAES. Depleted natural gas reservoirs represent another potential underground storage vessel for CAES because they have demonstrated their container function and may have the requisite porosity and permeability; however reservoirs have yet to be demonstrated as a functional/operational storage media for compressed air. Specifically, air introduced into a depleted natural gas reservoir presents a situation where an ignition and explosion potential may exist. This report presents the results of an initial study identifying issues associated with this phenomena as well as possible mitigating measures that should be considered.

  4. Arctic stratospheric ozone depletion and increased UVB radiation: potential impacts to human health.

    Science.gov (United States)

    De Fabo, Edward C

    2005-12-01

    Contrary to popular belief, stratospheric ozone depletion, and the resultant increase in solar UV-B (280-320 nm), are unlikely to fully recover soon. Notwithstanding the success of the Montreal Protocol in reducing the amount of ozone destroying chemicals into the stratosphere, the life-times of these compounds are such that even with full compliance with the Protocol by all countries, it will be decades before stratospheric ozone could return to pre-1980 levels. This raises the question, therefore, of what will happen to biological processes essential to the maintenance of life on earth which are sensitive to damage by increased UV-B radiation, particularly those involved with human health? The polar regions, because of the vagaries of climate and weather, are the bellwether for stratospheric ozone depletion and will, therefore, be the first to experience impacts due to increases in solar UV-B radiation. The impacts of these are incompletely understood and cannot be predicted with certainty. While some UV-B impacts on human health are recognized, much is unknown, unclear and uncertain. Thus, this paper attempts, as a first approximation, to point out potential impacts to the health and welfare of human inhabitants of the Arctic due to increased solar UV-B radiation associated with stratospheric ozone depletion. As will be seen, much more data is critically needed before adequate risk assessment can occur.

  5. Potential behavior of depleted uranium penetrators under shipping and bulk storage accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mishima, J.; Parkhurst, M.A.; Scherpelz, R.I.

    1985-03-01

    An investigation of the potential hazard from airborne releases of depleted uranium (DU) from the Army's M829 munitions was conducted at the Pacific Northwest Laboratory. The study included: (1) assessing the characteristics of DU oxide from an April 1983 burn test, (2) postulating conditions of specific accident situations, and (3) reviewing laboratory and theoretical studies of oxidation and airborne transport of DU from accidents. Results of the experimental measurements of the DU oxides were combined with atmospheric transport models and lung and kidney exposure data to help establish reasonable exclusion boundaries to protect personnel and the public at an accident site. 121 references, 44 figures, 30 tables.

  6. UV and infrared absorption spectra, atmospheric lifetimes, and ozone depletion and global warming potentials for CCl2FCCl2F (CFC-112), CCl3CClF2 (CFC-112a), CCl3CF3 (CFC-113a), and CCl2FCF3 (CFC-114a)

    Science.gov (United States)

    Davis, Maxine E.; Bernard, François; McGillen, Max R.; Fleming, Eric L.; Burkholder, James B.

    2016-07-01

    The potential impact of CCl2FCF3 (CFC-114a) and the recently observed CCl2FCCl2F (CFC-112), CCl3CClF2 (CFC-112a), and CCl3CF3 (CFC-113a) chlorofluorocarbons (CFCs) on stratospheric ozone and climate is presently not well characterized. In this study, the UV absorption spectra of these CFCs were measured between 192.5 and 235 nm over the temperature range 207-323 K. Precise parameterizations of the UV absorption spectra are presented. A 2-D atmospheric model was used to evaluate the CFC atmospheric loss processes, lifetimes, ozone depletion potentials (ODPs), and the associated uncertainty ranges in these metrics due to the kinetic and photochemical uncertainty. The CFCs are primarily removed in the stratosphere by short-wavelength UV photolysis with calculated global annually averaged steady-state lifetimes (years) of 63.6 (61.9-64.7), 51.5 (50.0-52.6), 55.4 (54.3-56.3), and 105.3 (102.9-107.4) for CFC-112, CFC-112a, CFC-113a, and CFC-114a, respectively. The range of lifetimes given in parentheses is due to the 2σ uncertainty in the UV absorption spectra and O(1D) rate coefficients included in the model calculations. The 2-D model was also used to calculate the CFC ozone depletion potentials (ODPs) with values of 0.98, 0.86, 0.73, and 0.72 obtained for CFC-112, CFC-112a, CFC-113a, and CFC-114a, respectively. Using the infrared absorption spectra and lifetimes determined in this work, the CFC global warming potentials (GWPs) were estimated to be 4260 (CFC-112), 3330 (CFC-112a), 3650 (CFC-113a), and 6510 (CFC-114a) for the 100-year time horizon.

  7. The potential importance of frost flowers, recycling on snow, and open leads for Ozone Depletion Events

    Directory of Open Access Journals (Sweden)

    M. Piot

    2007-04-01

    Full Text Available We present model studies with the one-dimensional model MISTRA to investigate the potential role of frost flowers, recycling on snow, and open leads in the depletion of tropospheric ozone in the Arctic spring. In our model, we assumed frost flower aerosols to be the major source of bromine. We show that a major ozone depletion event can be satisfactorily reproduced only if the recycling on snow of deposited bromine into gas phase bromine is assumed. In the model, this cycling is more efficient than the bromine explosion process and maintains sufficiently high levels of bromine to deplete ozone down to few nmol mol−1 within four days. We assessed the influence of different surface combinations (open lead/frost flowers on the chemistry in the model. Results showed noticeable modifications affecting the composition of aerosols and the deposition velocities. A model run with a series of coupled frost flower fields and open leads, separated by large areas of snow, showed results comparable with field observations. In addition, we studied the effects of modified temperature of either the frost flower field or the ambient airmass. A warmer frost flower field increases the relative humidity and the aerosol deposition rate. The deposition/re-emission process gains in importance, inducing more reactive bromine in the gas phase, and a stronger ozone depletion. A decrease of 1 K in airmass temperature shows in our model that the aerosol uptake capacities of all gas phase species substantially increases, leading to enhanced uptake of acids from the gas phase. Consequently, the so-called bromine explosion accelerated and O3 mixing ratios decreased. In our model representation, variations in wind speed affected the aerosol source function and influenced the amount of bromine in the atmosphere and thus the ozone depletion strength. Recent studies have suggested the important role of the precipitation of calcium carbonate (CaCO3

  8. The potential importance of frost flowers, recycling on snow, and open leads for ozone depletion events

    Directory of Open Access Journals (Sweden)

    M. Piot

    2008-05-01

    Full Text Available We present model studies with the one-dimensional model MISTRA to investigate the potential role of frost flowers, recycling on snow, and open leads in the depletion of tropospheric ozone in the Arctic spring. In our model, we assumed frost flower aerosols to be the major source of bromine. We show that a major ozone depletion event can be satisfactorily reproduced only if the recycling on snow of deposited bromine into gas phase bromine is assumed. In the model, this cycling is more efficient than the bromine explosion process and maintains sufficiently high levels of bromine to deplete ozone down to few nmol mol−1 within four days. We assessed the influence of different surface combinations (open lead/frost flowers on the chemistry in the model. Results showed noticeable modifications affecting the composition of aerosols and the deposition velocities. A model run with a series of coupled frost flower fields and open leads, separated by large areas of snow, showed results comparable with field observations. In addition, we studied the effects of modified temperature of either the frost flower field or the ambient airmass. A warmer frost flower field increases the relative humidity and the aerosol deposition rate. The deposition/re-emission process gains in importance, inducing more reactive bromine in the gas phase, and a stronger ozone depletion. A decrease of 1K in airmass temperature shows in our model that the aerosol uptake capacities of all gas phase species substantially increases, leading to enhanced uptake of acids from the gas phase. Consequently, the so-called bromine explosion accelerated and O3 mixing ratios decreased. In our model representation, variations in wind speed affected the aerosol source function and influenced the amount of bromine in the atmosphere and thus the ozone depletion strength. Recent studies have suggested the important role of the precipitation of calcium carbonate (CaCO3

  9. Assessing Groundwater Depletion and Dynamics Using GRACE and InSAR: Potential and Limitations.

    Science.gov (United States)

    Castellazzi, Pascal; Martel, Richard; Galloway, Devin L; Longuevergne, Laurent; Rivera, Alfonso

    2016-11-01

    In the last decade, remote sensing of the temporal variation of ground level and gravity has improved our understanding of groundwater dynamics and storage. Mass changes are measured by GRACE (Gravity Recovery and Climate Experiment) satellites, whereas ground deformation is measured by processing synthetic aperture radar satellites data using the InSAR (Interferometry of Synthetic Aperture Radar) techniques. Both methods are complementary and offer different sensitivities to aquifer system processes. GRACE is sensitive to mass changes over large spatial scales (more than 100,000 km(2) ). As such, it fails in providing groundwater storage change estimates at local or regional scales relevant to most aquifer systems, and at which most groundwater management schemes are applied. However, InSAR measures ground displacement due to aquifer response to fluid-pressure changes. InSAR applications to groundwater depletion assessments are limited to aquifer systems susceptible to measurable deformation. Furthermore, the inversion of InSAR-derived displacement maps into volume of depleted groundwater storage (both reversible and largely irreversible) is confounded by vertical and horizontal variability of sediment compressibility. During the last decade, both techniques have shown increasing interest in the scientific community to complement available in situ observations where they are insufficient. In this review, we present the theoretical and conceptual bases of each method, and present idealized scenarios to highlight the potential benefits and challenges of combining these techniques to remotely assess groundwater storage changes and other aspects of the dynamics of aquifer systems.

  10. Assessing groundwater depletion and dynamics using GRACE and InSAR: Potential and limitations

    Science.gov (United States)

    Castellazzi, Pascal; Martel, Richard; Galloway, Devin L.; Longuevergne, Laurent; Rivera, Alfonso

    2016-01-01

    In the last decade, remote sensing of the temporal variation of ground level and gravity has improved our understanding of groundwater dynamics and storage. Mass changes are measured by GRACE (Gravity Recovery and Climate Experiment) satellites, whereas ground deformation is measured by processing synthetic aperture radar satellites data using the InSAR (Interferometry of Synthetic Aperture Radar) techniques. Both methods are complementary and offer different sensitivities to aquifer system processes. GRACE is sensitive to mass changes over large spatial scales (more than 100,000 km2). As such, it fails in providing groundwater storage change estimates at local or regional scales relevant to most aquifer systems, and at which most groundwater management schemes are applied. However, InSAR measures ground displacement due to aquifer response to fluid-pressure changes. InSAR applications to groundwater depletion assessments are limited to aquifer systems susceptible to measurable deformation. Furthermore, the inversion of InSAR-derived displacement maps into volume of depleted groundwater storage (both reversible and largely irreversible) is confounded by vertical and horizontal variability of sediment compressibility. During the last decade, both techniques have shown increasing interest in the scientific community to complement available in situ observations where they are insufficient. In this review, we present the theoretical and conceptual bases of each method, and present idealized scenarios to highlight the potential benefits and challenges of combining these techniques to remotely assess groundwater storage changes and other aspects of the dynamics of aquifer systems.

  11. Asparagine depletion potentiates the cytotoxic effect of chemotherapy against brain tumors.

    Science.gov (United States)

    Panosyan, Eduard H; Wang, Yuntao; Xia, Peng; Lee, Wai-Nang Paul; Pak, Youngju; Laks, Dan R; Lin, Henry J; Moore, Theodore B; Cloughesy, Timothy F; Kornblum, Harley I; Lasky, Joseph L

    2014-05-01

    Targeting amino acid metabolism has therapeutic implications for aggressive brain tumors. Asparagine is an amino acid that is synthesized by normal cells. However, some cancer cells lack asparagine synthetase (ASNS), the key enzyme for asparagine synthesis. Asparaginase (ASNase) contributes to eradication of acute leukemia by decreasing asparagine levels in serum and cerebrospinal fluid. However, leukemic cells may become ASNase-resistant by upregulating ASNS. High expression of ASNS has also been associated with biologic aggressiveness of other cancers, including gliomas. Here, the impact of enzymatic depletion of asparagine on proliferation of brain tumor cells was determined. ASNase was used as monotherapy or in combination with conventional chemotherapeutic agents. Viability assays for ASNase-treated cells demonstrated significant growth reduction in multiple cell lines. This effect was reversed by glutamine in a dose-dependent manner--as expected, because glutamine is the main amino group donor for asparagine synthesis. ASNase treatment also reduced sphere formation by medulloblastoma and primary glioblastoma cells. ASNase-resistant glioblastoma cells exhibited elevated levels of ASNS mRNA. ASNase cotreatment significantly enhanced gemcitabine or etoposide cytotoxicity against glioblastoma cells. Xenograft tumors in vivo showed no significant response to ASNase monotherapy and little response to temozolomide alone. However, combinatorial therapy with ASNase and temozolomide resulted in significant growth suppression for an extended duration of time. Taken together, these findings indicate that amino acid depletion warrants further investigation as adjunctive therapy for brain tumors. Findings have potential impact for providing adjuvant means to enhance brain tumor chemotherapy. ©2014 AACR.

  12. Evaluation of the Acceptability of Potential Depleted Uranium Hexafluoride Conversion Products at the Envirocare Disposal Site

    Energy Technology Data Exchange (ETDEWEB)

    Croff, A.G.

    2001-01-11

    The purpose of this report is to review and document the capability of potential products of depleted UF{sub 6} conversion to meet the current waste acceptance criteria and other regulatory requirements for disposal at the facility in Clive, Utah, owned by Envirocare of Utah, Inc. The investigation was conducted by identifying issues potentially related to disposal of depleted uranium (DU) products at Envirocare and conducting an initial analysis of them. Discussions were then held with representatives of Envirocare, the state of Utah (which is a NRC Agreement State and, thus, is the cognizant regulatory authority for Envirocare), and DOE Oak Ridge Operations. Provisional issue resolution was then established based on the analysis and discussions and documented in a draft report. The draft report was then reviewed by those providing information and revisions were made, which resulted in this document. Issues that were examined for resolution were (1) license receipt limits for U isotopes; (2) DU product classification as Class A waste; (3) use of non-DOE disposal sites for disposal of DOE material; (4) historical NRC views; (5) definition of chemical reactivity; (6) presence of mobile radionuclides; and (7) National Environmental Policy Act coverage of disposal. The conclusion of this analysis is that an amendment to the Envirocare license issued on October 5, 2000, has reduced the uncertainties regarding disposal of the DU product at Envirocare to the point that they are now comparable with uncertainties associated with the disposal of the DU product at the Nevada Test Site that were discussed in an earlier report.

  13. Potential health effects of greenhouse effect and ozone layer depletion in Australia.

    Science.gov (United States)

    Ewan, C; Bryant, E A; Calvert, G D; Marthick, J; Condon-Paoloni, D

    1991-04-15

    To identify potential health effects of the greenhouse effect and ozone layer depletion in Australia. Data were derived from a number of sources: (i) published articles accessed from relevant databases in the disciplines of health, public health and climatology over the past 20 years; (ii) published conference proceedings, review monographs and government reports covering the topic; (iii) a survey of experts in public health and climatology/geography (150 individuals were surveyed in the first phase with a 63% response rate); and (iv) a consensus conference in which 22 invited experts reviewed the results of the literature review and survey and a second conference in which 18 senior members of the health bureaucracy and public health profession considered the implications of the findings. Over 200 published articles or monographs were reviewed. Criteria for selection were whether the papers contributed information to the objectives of the review. Because of the nature of the problem under investigation, predictions based on reasonable scientific assumptions were the major content of the review rather than conclusions based on scientific research. The major predicted health effects of long-term climatic change in Australia are skin and eye damage from increased ultraviolet radiation exposure, increased incidence of some respiratory diseases, vector-borne and water-borne diseases, and the social and physical effects of natural hazards and social and economic restructuring. The most vulnerable groups include the aged, the very young, the chronically ill, those living in poorly designed neighbourhoods and those working in outdoor occupations or heavy industry. The potential effects on health of long-term climatic change cover the broad spectrum of public health concerns. Detailed predictions of likely problems in specific geographic areas are not yet possible, but progressive development of such predictive capability is a high priority. Doctors will have an

  14. Assessment of the micro-structure and depletion potentials in two-dimensional binary mixtures of additive hard-disks

    Science.gov (United States)

    Perera-Burgos, Jorge Adrián; Méndez-Alcaraz, José Miguel; Pérez-Ángel, Gabriel; Castañeda-Priego, Ramón

    2016-09-01

    Depletion forces are a particular class of effective interactions that have been mainly investigated in binary mixtures of hard-spheres in bulk. Although there are a few contributions that point toward the effects of confinement on the depletion potential, little is known about such entropic potentials in two-dimensional colloidal systems. From theoretical point of view, the problem resides in the fact that there is no general formulation of depletion forces in arbitrary dimensions and, typically, any approach that works well in three dimensions has to be reformulated for lower dimensionality. However, we have proposed a theoretical framework, based on the formalism of contraction of the description within the integral equations theory of simple liquids, to account for effective interactions in colloidal liquids, whose main feature is that it does not need to be readapted to the problem under consideration. We have also shown that such an approach allows one to determine the depletion pair potential in three-dimensional colloidal mixtures even near to the demixing transition, provided the bridge functions are sufficiently accurate to correctly describe the spatial correlation between colloids [E. López-Sánchez et al., J. Chem. Phys. 139, 104908 (2013)]. We here report an extensive analysis of the structure and the entropic potentials in binary mixtures of additive hard-disks. In particular, we show that the same functional form of the modified-Verlet closure relation used in three dimensions can be straightforwardly employed to obtain an accurate solution for two-dimensional colloidal mixtures in a wide range of packing fractions, molar fractions, and size asymmetries. Our theoretical results are explicitly compared with the ones obtained by means of event-driven molecular dynamics simulations and recent experimental results. Furthermore, to assess the accuracy of our predictions, the depletion potentials are used in an effective one-component model to reproduce

  15. Selected flavonoids potentiate the toxicity of cisplatin in human lung adenocarcinoma cells: A role for glutathione depletion

    OpenAIRE

    Kachadourian, Remy; LEITNER, VHEATHER M.; Day, Brian J.

    2007-01-01

    Adjuvant therapies that enhance the anti-tumor effects of cisplatin are actively being pursued. Growing evidence supports the involvement of mitochondrial dysfunction in the anti-cancer effect of cis-diammineplatinum(II) dichloride (cisplatin, CDDP). We examined the potential of using selective flavonoids that are effective in depleting tumor cells of glu-tathione (GSH) to potentiate cisplatin-mediated cytotoxicity in human lung adenocarcinoma (A549) cells. We found that cisplatin (40 μM, 48-...

  16. Solid state speciation and potential bioavailability of depleted uranium particles from Kosovo and Kuwait

    Energy Technology Data Exchange (ETDEWEB)

    Lind, O.C. [Isotope Laboratory, Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 As (Norway)], E-mail: ole-christian.lind@umb.no; Salbu, B.; Skipperud, L. [Isotope Laboratory, Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 As (Norway); Janssens, K.; Jaroszewicz, J.; De Nolf, W. [Department of Chemistry, University of Antwerp, Universiteitsplein 1, Antwerp (Belgium)

    2009-04-15

    A combination of synchrotron radiation based X-ray microscopic techniques ({mu}-XRF, {mu}-XANES, {mu}-XRD) applied on single depleted uranium (DU) particles and semi-bulk leaching experiments has been employed to link the potential bioavailability of DU particles to site-specific particle characteristics. The oxidation states and crystallographic forms of U in DU particles have been determined for individual particles isolated from selected samples collected at different sites in Kosovo and Kuwait that were contaminated by DU ammunition during the 1999 Balkan conflict and the 1991 Gulf war. Furthermore, small soil or sand samples heavily contaminated with DU particles were subjected to simulated gastrointestinal fluid (0.16 M HCl) extractions. Characteristics of DU particles in Kosovo soils collected in 2000 and in Kuwait soils collected in 2002 varied significantly depending on the release scenario and to some extent on weathering conditions. Oxidized U (+6) was determined in large, fragile and bright yellow DU particles released during fire at a DU ammunition storage facility and crystalline phases such as schoepite (UO{sub 3}.2.25H{sub 2}O), dehydrated schoepite (UO{sub 3}.0.75H{sub 2}O) and metaschoepite (UO{sub 3}.2.0H{sub 2}O) were identified. As expected, these DU particles were rapidly dissolved in 0.16 M HCl (84 {+-} 3% extracted after 2 h) indicating a high degree of potential mobility and bioavailability. In contrast, the 2 h extraction of samples contaminated with DU particles originating either from corrosion of unspent DU penetrators or from impacted DU ammunition appeared to be much slower (20-30%) as uranium was less oxidized (+4 to +6). Crystalline phases such as UO{sub 2}, UC and metallic U or U-Ti alloy were determined in impacted DU particles from Kosovo and Kuwait, while the UO{sub 2,34} phase, only determined in particles from Kosovo, could reflect a more corrosive environment. Although the results are based on a limited number of DU particles

  17. Depletion potentials in highly size-asymmetric binary hard-sphere mixtures: comparison of simulation results with theory.

    Science.gov (United States)

    Ashton, Douglas J; Wilding, Nigel B; Roth, Roland; Evans, Robert

    2011-12-01

    We report a detailed study, using state-of-the-art simulation and theoretical methods, of the effective (depletion) potential between a pair of big hard spheres immersed in a reservoir of much smaller hard spheres, the size disparity being measured by the ratio of diameters q ≡ σ(s)/σ(b). Small particles are treated grand canonically, their influence being parameterized in terms of their packing fraction in the reservoir η(s)(r). Two Monte Carlo simulation schemes--the geometrical cluster algorithm, and staged particle insertion--are deployed to obtain accurate depletion potentials for a number of combinations of q ≤ 0.1 and η(s)(r). After applying corrections for simulation finite-size effects, the depletion potentials are compared with the prediction of new density functional theory (DFT) calculations based on the insertion trick using the Rosenfeld functional and several subsequent modifications. While agreement between the DFT and simulation is generally good, significant discrepancies are evident at the largest reservoir packing fraction accessible to our simulation methods, namely, η(s)(r) = 0.35. These discrepancies are, however, small compared to those between simulation and the much poorer predictions of the Derjaguin approximation at this η(s)(r). The recently proposed morphometric approximation performs better than Derjaguin but is somewhat poorer than DFT for the size ratios and small-sphere packing fractions that we consider. The effective potentials from simulation, DFT, and the morphometric approximation were used to compute the second virial coefficient B(2) as a function of η(s)(r). Comparison of the results enables an assessment of the extent to which DFT can be expected to correctly predict the propensity toward fluid-fluid phase separation in additive binary hard-sphere mixtures with q ≤ 0.1. In all, the new simulation results provide a fully quantitative benchmark for assessing the relative accuracy of theoretical approaches for

  18. Glutathione depletion and carbon ion radiation potentiate clustered DNA lesions, cell death and prevent chromosomal changes in cancer cells progeny.

    Directory of Open Access Journals (Sweden)

    Maïté Hanot

    Full Text Available Poor local control and tumor escape are of major concern in head-and-neck cancers treated by conventional radiotherapy or hadrontherapy. Reduced glutathione (GSH is suspected of playing an important role in mechanisms leading to radioresistance, and its depletion should enable oxidative stress insult, thereby modifying the nature of DNA lesions and the subsequent chromosomal changes that potentially lead to tumor escape.This study aimed to highlight the impact of a GSH-depletion strategy (dimethylfumarate, and L-buthionine sulfoximine association combined with carbon ion or X-ray irradiation on types of DNA lesions (sparse or clustered and the subsequent transmission of chromosomal changes to the progeny in a radioresistant cell line (SQ20B expressing a high endogenous GSH content. Results are compared with those of a radiosensitive cell line (SCC61 displaying a low endogenous GSH level. DNA damage measurements (γH2AX/comet assay demonstrated that a transient GSH depletion in resistant SQ20B cells potentiated the effects of irradiation by initially increasing sparse DNA breaks and oxidative lesions after X-ray irradiation, while carbon ion irradiation enhanced the complexity of clustered oxidative damage. Moreover, residual DNA double-strand breaks were measured whatever the radiation qualities. The nature of the initial DNA lesions and amount of residual DNA damage were similar to those observed in sensitive SCC61 cells after both types of irradiation. Misrepaired or unrepaired lesions may lead to chromosomal changes, estimated in cell progeny by the cytome assay. Both types of irradiation induced aberrations in nondepleted resistant SQ20B and sensitive SCC61 cells. The GSH-depletion strategy prevented the transmission of aberrations (complex rearrangements and chromosome break or loss in radioresistant SQ20B only when associated with carbon ion irradiation. A GSH-depleting strategy combined with hadrontherapy may thus have considerable

  19. Glutathione depletion and carbon ion radiation potentiate clustered DNA lesions, cell death and prevent chromosomal changes in cancer cells progeny.

    Science.gov (United States)

    Hanot, Maïté; Boivin, Anthony; Malésys, Céline; Beuve, Michaël; Colliaux, Anthony; Foray, Nicolas; Douki, Thierry; Ardail, Dominique; Rodriguez-Lafrasse, Claire

    2012-01-01

    Poor local control and tumor escape are of major concern in head-and-neck cancers treated by conventional radiotherapy or hadrontherapy. Reduced glutathione (GSH) is suspected of playing an important role in mechanisms leading to radioresistance, and its depletion should enable oxidative stress insult, thereby modifying the nature of DNA lesions and the subsequent chromosomal changes that potentially lead to tumor escape.This study aimed to highlight the impact of a GSH-depletion strategy (dimethylfumarate, and L-buthionine sulfoximine association) combined with carbon ion or X-ray irradiation on types of DNA lesions (sparse or clustered) and the subsequent transmission of chromosomal changes to the progeny in a radioresistant cell line (SQ20B) expressing a high endogenous GSH content. Results are compared with those of a radiosensitive cell line (SCC61) displaying a low endogenous GSH level. DNA damage measurements (γH2AX/comet assay) demonstrated that a transient GSH depletion in resistant SQ20B cells potentiated the effects of irradiation by initially increasing sparse DNA breaks and oxidative lesions after X-ray irradiation, while carbon ion irradiation enhanced the complexity of clustered oxidative damage. Moreover, residual DNA double-strand breaks were measured whatever the radiation qualities. The nature of the initial DNA lesions and amount of residual DNA damage were similar to those observed in sensitive SCC61 cells after both types of irradiation. Misrepaired or unrepaired lesions may lead to chromosomal changes, estimated in cell progeny by the cytome assay. Both types of irradiation induced aberrations in nondepleted resistant SQ20B and sensitive SCC61 cells. The GSH-depletion strategy prevented the transmission of aberrations (complex rearrangements and chromosome break or loss) in radioresistant SQ20B only when associated with carbon ion irradiation. A GSH-depleting strategy combined with hadrontherapy may thus have considerable advantage in the

  20. Fishery induces sperm depletion and reduction in male reproductive potential for crab species under male-biased harvest strategy.

    Directory of Open Access Journals (Sweden)

    Luis Miguel Pardo

    Full Text Available Sperm depletion in males can occur when polygynous species are intensively exploited under a male-biased management strategy. In fisheries involving crabs species, the effects of this type of management on the reproductive potential is far from being understood. This study tests whether male-biased management of the principal Chilean crab fishery is able to affect the potential capacity of Metacarcinus edwardsii males to transfer sperm to females. Five localities in southern Chile, recording contrasting crab fishery landing, were selected to assess the potential of sperm depletion triggered by fishery. Seasonally, male crabs from each locality were obtained. Dry weight and histological condition of vasa deferentia and the Vaso-Somatic Index (VSI were determined in order to use them as proxies for sperm depletion and male reproductive condition. A manipulative experiment was performed in the laboratory to estimate vasa deferentia weight and VSI from just-mated males in order to obtain a reference point for the potential effects of the fishery on sperm reserves. Sperm storage capacity is significantly affected by fisheries; during the mating season vasa deferentia from localities with low fishery intensity were heavier than those from high intensity fisheries, and these differences were even more evident in large males. Histological section showed that this disparity in vasa deferentia weight was explained principally by differences in the quantity of spermatophores rather than other seminal material. VSI was always higher in males from localities with low fishery intensity. Males from localities with high fishery intensity showed little capacity to recover sperm reserves and the VSI of these males remained below the values of the just-mated males. Detriment in the capacity of males to transfer sperm is the first step to sperm limitation in an exploited population, thus detection of sperm depletion can be an alert to introduce changes in the

  1. Ultraviolet radiation in the Arctic - The impact of potential ozone depletions and cloud effects

    Science.gov (United States)

    Tsay, Si-Chee; Stamnes, Knut

    1992-01-01

    The combined effects of ozone depletions/redistributions and particulate clouds on atmospheric cheating/photolysis rates and UV radiation reaching the biosphere are investigated by means of an atmospheric radiation model. Consideration is given to four types of particulate clouds prevalent in the summertime Arctic: stratospheric aerosols, tropospheric aerosols (Arctic haze), cirrus clouds, and stratus clouds. The effects of ozone depletion and vertical redistributions of ozone are also examined. Stratus clouds are found to provide significant protection from UV radiation exposure, but while stratospheric aerosols imply increased UVB exposure, Arctic haze results in a decrease. A redistribution of ozone from the stratosphere to the troposphere tends to decrease UV exposure, but for low solar elevations an increase may occur. A 20-percent ozone depletion leads to about 0.4 K/d cooling in the lower stratosphere, while redistribution of ozone from the stratosphere to the troposphere implies a warming of about 0.015 K/d in the upper troposphere.

  2. Depletion of histone demethylase KDM2A enhanced the adipogenic and chondrogenic differentiation potentials of stem cells from apical papilla

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Rui [Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China); Yao, Rui [Department of Pediatrics, Stomatological Hospital of Nankai University, Tianjin 300041 (China); Du, Juan [Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China); Wang, Songlin [Molecular Laboratory for Gene Therapy and Tooth Regeneration, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China); Department of Biochemistry and Molecular Biology, Capital Medical University School of Basic Medical Sciences, Beijing 100069 (China); Fan, Zhipeng, E-mail: zpfan@ccmu.edu.cn [Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050 (China)

    2013-11-01

    Mesenchymal stem cells (MSCs) are a reliable resource for tissue regeneration, but the molecular mechanism underlying directed differentiation remains unclear; this has restricted potential MSC applications. The histone demethylase, lysine (K)-specific demethylase 2A (KDM2A), is evolutionarily conserved and ubiquitously expressed members of the JmjC-domain-containing histone demethylase family. A previous study determined that KDM2A can regulate the cell proliferation and osteo/dentinogenic differentiation of MSCs. It is not known whether KDM2A is involved in the other cell lineages differentiation of MSCs. Here, we show that depletion of KDM2A by short hairpin RNAs can enhance adipogenic and chondrogenic differentiation potentials in human stem cells from apical papilla (SCAPs). We found that the stemness-related genes, SOX2, and the embryonic stem cell master transcription factor, NANOG were significantly increased after silence of KDM2A in SCAPs. Moreover, we found that knock-down of the KDM2A co-factor, BCOR also up-regulated the mRNA levels of SOX2 and NANOG. Furthermore, Chromatin immunoprecipitation assays demonstrate that silence of KDM2A increased the histone H3 Lysine 4 (H3K4) trimethylation in the SOX2 and NANOG locus and regulates its expression. In conclusion, our results suggested that depletion of KDM2A enhanced the adipogenic and chondrogenic differentiation potentials of SCAPs by up-regulated SOX2 and NANOG, BCOR also involved in this regulation as co-factor, and provided useful information to understand the molecular mechanism underlying directed differentiation in MSCs. - Highlights: • Depletion of KDM2A enhances adipogenic/chondrogenic differentiation in SCAPs. • Depletion of KDM2A enhances the differentiation of SCAPs by activate SOX2 and NANOG. • Silence of KDM2A increases histone H3 Lysine 4 trimethylation in SOX2 and NANOG. • BCOR is co-factor of KDM2A involved in the differentiation regulation.

  3. [Plant reaction to elevated ultraviolet irradiation: potential impacts of stratospheric ozone depletion].

    Science.gov (United States)

    Strzhizhovskiĭ, A D

    1999-01-01

    The ozone layer depletion evokes the increase of solar UV-B radiation intensity and corresponding reductions of growth (height, leaf area, fresh and dry weight), photosynthetic activity and flowering in higher plants. Competitive interactions also may be altered indirectly by differential growth responses. The UV-B-sensitivity of plants varies both among species and among cultivars of a given species. Photosynthetic activity may be reduced by direct effects on the photosynthetic process or metabolic pathways, or indirectly through effects on photosynthetic pigments or stomatal function. Plants may also respond by accumulating UV-absorbing compounds in their outer tissue layers, which presumably protect sensitive target from UV-damage. The key enzymes in the biosynthetic pathways of these compounds are specifically induced by UV-B irradiation via gene activation. The effects of UV-B radiation on plants can be modified by prevailing microclimatic conditions. Plants tend to be less sensitive to UV-B under drought or mineral deficiency, while sensitivity increases under low levels of visible light. Prognoses of agricultural yield reduction and economic loss for different scenarious of stratospheric ozone depletion are presented.

  4. Carbonate precipitation in brine – a potential trigger for tropospheric ozone depletion events

    Directory of Open Access Journals (Sweden)

    R. Sander

    2006-01-01

    Full Text Available Tropospheric ozone depletion events (ODEs at high latitudes were discovered 20 years ago and are attributed to bromine explosions. However, an unresolved issue is the explanation of how the acid-catalyzed reaction cycle is triggered in atmospheric particles derived from alkaline sea water. By simulating the chemistry occuring in polar regions over recently formed sea ice, we can model successfully the transformation of inert sea-salt bromide to reactive bromine monoxide (BrO and the subsequent ODE when precipitation of calcium carbonate from freezing sea water is taken into account. In addition, we found the temperature dependence of the equilibrium BrCl+Br−↔Br2Cl− to be important.

  5. Next Generation Refrigeration Lubricants for Low Global Warming Potential/Low Ozone Depleting Refrigeration and Air Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    Hessell, Edward

    2013-12-31

    The goal of this project is to develop and test new synthetic lubricants that possess high compatibility with new low ozone depleting (LOD) and low global warming potential (LGWP) refrigerants and offer improved lubricity and wear protection over current lubricant technologies. The improved compatibility of the lubricants with the refrigerants, along with improved lubricating properties, will resulted in lower energy consumption and longer service life of the refrigeration systems used in residential, commercial and industrial heating, ventilating and air-conditioning (HVAC) and refrigeration equipment.

  6. Next Generation Refrigeration Lubricants for Low Global Warming Potential/Low Ozone Depleting Refrigeration and Air Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    Hessell, Edward Thomas [Chemtura Corporation, Middlebury, CT (United States)

    2013-12-31

    The goal of this project is to develop and test new synthetic lubricants that possess high compatibility with new low ozone depleting (LOD) and low global warming potential (LGWP) refrigerants and offer improved lubricity and wear protection over current lubricant technologies. The improved compatibility of the lubricants with the refrigerants, along with improved lubricating properties, will resulted in lower energy consumption and longer service life of the refrigeration systems used in residential, commercial and industrial heating, ventilating and air-conditioning (HVAC) and refrigeration equipment.

  7. Archive of Core and Site/Hole Data and Photographs from the Ocean Drilling Program (ODP)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Drilling Program (ODP) operated the drilling vessel JOIDES Resolution from 1984-2003 for over 100 cruises worldwide. The ODP was funded by the U.S....

  8. Surface Potential and Threshold Voltage Model of Fully Depleted Narrow Channel SOI MOSFET Using Analytical Solution of 3D Poisson’s Equation

    Directory of Open Access Journals (Sweden)

    Prashant Mani

    2015-06-01

    Full Text Available The present paper is about the modeling of surface potential and threshold voltage of Fully Depleted Silicon on Insulator MOSFET. The surface potential is calculated by solving the 3D Poisson’s equation analytically. The appropriate boundary conditions are used in calculations. The effect of narrow channel width and short channel length for suppression of SCE is analyzed. The narrow channel width effect in the threshold voltage is analyzed for thin film Fully Depleted SOI MOSFET.

  9. Aerobic Exercise As a Potential Way to Improve Self-Control after Ego-Depletion in Healthy Female College Students.

    Science.gov (United States)

    Zou, Zhiling; Liu, Yang; Xie, Jing; Huang, Xiting

    2016-01-01

    To test whether aerobic exercise can help build self-control stamina in healthy female young adults. Stamina in this context is defined as the capability to endure ego depletion, which can be measured with a self-control task following another activity also requiring self-control. Forty-five healthy undergraduate women were randomized to either an experimental group or control group. Participants in the experimental group were required to run in their campus running field for 30 min for a period of 5 weeks. Individuals in the control group were required to do diary entries regarding self-control in their daily lives, also for a period of 5 weeks. Before and after the 5-week intervention, participants completed a pain threshold test, a color word Stroop task and the following Cold Pressor Task (CPT) (with and without a distraction component). There was significant decrease of pain tolerance in session 2 relative to session 1 in the control group, but no such decline was found in the experimental group (though the improvement of pain tolerance was not significant), possibly suggesting successful self-control against this kind of decline. Five weeks of aerobic exercise increased self-control after ego depletion in terms of pain tolerance. These findings suggest that aerobic exercise may serve as a potential effective intervention for enhancing self-control in a college female population.

  10. Potential health implications of water resources depletion and sewage discharges in the Republic of Macedonia.

    Science.gov (United States)

    Hristovski, Kiril D; Pacemska-Atanasova, Tatjana; Olson, Larry W; Markovski, Jasmina; Mitev, Trajce

    2016-08-01

    Potential health implications of deficient sanitation infrastructure and reduced surface water flows due to climate change are examined in the case study of the Republic of Macedonia. Changes in surface water flows and wastewater discharges over the period 1955-2013 were analyzed to assess potential future surface water contamination trends. Simple model predictions indicated a decline in surface water hydrology over the last half century, which caused the surface waters in Macedonia to be frequently dominated by >50% of untreated sewage discharges. The surface water quality deterioration is further supported by an increasing trend in modeled biochemical oxygen demand trends, which correspond well with the scarce and intermittent water quality data that are available. Facilitated by the climate change trends, the increasing number of severe weather events is already triggering flooding of the sewage-dominated rivers into urban and non-urban areas. If efforts to develop a comprehensive sewage collection and treatment infrastructure are not implemented, such events have the potential to increase public health risks and cause epidemics, as in the 2015 case of a tularemia outbreak.

  11. Shear-affected depletion interaction

    NARCIS (Netherlands)

    July, C.; Kleshchanok, D.; Lang, P.R.

    2012-01-01

    We investigate the influence of flow fields on the strength of the depletion interaction caused by disc-shaped depletants. At low mass concentration of discs, it is possible to continuously decrease the depth of the depletion potential by increasing the applied shear rate until the depletion force i

  12. Three-dimensional modeling of HCFC-123 in the atmosphere: assessing its potential environmental impacts and rationale for continued use.

    Science.gov (United States)

    Wuebbles, Donald J; Patten, Kenneth O

    2009-05-01

    HCFC-123 (C2HCl2F3) is used in large refrigeration systems and as a fire suppression agent blend. Like other hydrochlorofluorocarbons, production and consumption of HCFC-123 is limited under the Montreal Protocol on Substances that Deplete the Ozone Layer. The purpose of this study is to update the understanding of the current and projected impacts of HCFC-123 on stratospheric ozone and on climate and to discuss the potential environmental effects from continued use of this chemical for specific applications. For the first time, the Ozone Depletion Potential (ODP) of a HCFC is determined using a three-dimensional model (MOZART-3) of atmospheric physics and chemistry. All previous studies have relied on results from two-dimensional models. The derived HCFC-123 ODP of 0.0098 is smaller than previous values. Analysis of the projected uses and emissions of HCFC-123, assuming reasonable levels of projected growth and use in centrifugal chiller and fire suppressant applications, suggests an extremely small impact on the environment due to its short atmospheric lifetime, low ODP, low Global Warming Potential (GWP), and the small production and emission of its limited applications. The current contribution of HCFC-123 to stratospheric reactive chlorine is too small to be measurable.

  13. Development of mass production type rigid polyurethane foam for LNG carrier using ozone depletion free blowing agent

    Science.gov (United States)

    Lee, Yeongbeom; Baek, Kye Hyun; Choe, Kunhyung; Han, Chonghun

    2016-12-01

    Nowadays the price of natural gas has become higher and the efficiency of propulsion system of liquefied natural gas (LNG) carriers has improved. Due to these trends, required boil-off rate (BOR) for LNG carrier has been lowered from 0.15%/day to 0.12%/day for conventional LNG carriers with sizes between 125,000 m3 and 170,000 m3. This requirement of BOR can be satisfied by using a rigid polyurethane foam (PUF) blown by 1,1-dichloro-1-fluoroethane (HCFC-141b) as an insulator. However, ozone depletion potential (ODP) of HCFC-141b requires alternative blowing agents with zero ODP such as hydroflurocarbons (HFCs) because of tougher environmental regulations. This paper introduces use of HFCs and additives to enhance properties of rigid PUFs under a mass production environment. Among the additives, perfluoroalkane (PFA) reduces thermal conductivity down to 12% and increases compressive strength up to 15% of a rigid PUF prepared in a laboratory scale. Based on this result, a mass production type rigid PUF is manufactured and is evaluated for BOR, mechanical strengths over operation temperature range, and thermal shock stability for LNG carriers. The BOR of the manufactured rigid PUF is below 0.12%/day, which satisfies the recent BOR specification for LNG carriers. The other required properties are also met the specifications for a conventional LNG carrier. Consequently, it is expected that the results in this paper will bring low BOR (LNG carries with rigid PUFs using ODP free blowing agents and contribute environmental protection through saving energy and preserving the ozone layer in the stratosphere.

  14. Phylogenetic Characterization of Marine Benthic Archaea in Organic-Poor Sediments of the Eastern Equatorial Pacific Ocean (ODP Site 1225).

    Science.gov (United States)

    Lauer, Antje; Sørensen, Ketil Bernt; Teske, Andreas

    2016-09-06

    Sequencing surveys of microbial communities in marine subsurface sediments have focused on organic-rich, continental margins; the database for organic-lean deep-sea sediments from mid-ocean regions is underdeveloped. The archaeal community in subsurface sediments of ODP Site 1225 in the eastern equatorial Pacific (3760 m water depth; 1.1 and 7.8 m sediment depth) was analyzed by PCR, cloning and sequencing, and by denaturant gradient gel electrophoresis (DGGE) of 16S rRNA genes. Three uncultured archaeal lineages with different depth distributions were found: Marine Group I (MG-I) within the Thaumarchaeota, its sister lineage Marine Benthic Group A (MBG-A), the phylum-level archaeal lineage Marine Benthic Group B (also known as Deep-Sea Archaeal Group or Lokiarchaeota), and the Deep-Sea Euryarchaeotal Group 3. The MG-I phylotypes included representatives of sediment clusters that are distinct from the pelagic members of this phylum. On the scale from fully oxidized, extremely organic carbon-depleted sediments (for example, those the South Pacific Gyre) to fully reduced, organic carbon-rich marine subsurface sediments (such as those of the Peru Margin), Ocean Drilling Program (ODP) Site 1225 falls into the non-extreme organic carbon-lean category, and harbors archaeal communities from both ends of the spectrum.

  15. Substituting HCFC-22 for HFC-410A: an environmental impact trade-off between the ozone depletion and climate change regimes

    Science.gov (United States)

    Wang, Z.; Fang, X.; Zhang, J.

    2015-12-01

    After the phase-out of hydrochlorofluorocarbons (HCFCs) as ozone-depleting substances pursuant to the requirements of the Montreal Protocol, hydrofluorocarbons (HFCs) are worldwide used as substitutes although the bulk of them are potent greenhouse gases (GHGs). Therefore, the alternation may bring side effect on global climate change. The trade-off of its environmental impacts between the ozone depletion and climate change regimes necessitates a quantification of the past and future consumption and emissions of both the original HCFCs and their alternative HFCs. Now a dilemma arise in China's RAC industry that HCFC-22, which has an ozone-depleting potential (ODP) of 0.055, has been replaced by HFC-410A, which is a blended potent GHG from respective 50% HFC-32 and HFC-125 with a global warming potential (GWP) of 1923.5. Here, we present our results of estimates of consumption and emissions of HCFC-22 and HFC-410A from 1994 to 2050. Historic emissions of HCFC-22 contributed to global total HCFCs by 4.0% (3.0%-5.6%) ODP-weighted. Projection under a baseline scenario shows future accumulative emissions of HFC-410A make up 5.9%-11.0% of global GWP-weighted HFCs emissions, and its annual contribution to national overall CO2 emissions can be 5.5% in 2050. This makes HCFC-22 and HFC-410A emissions of significant importance in ozone depletion and climate change regimes. Two mitigation scenarios were set to assess the mitigation performance under the North America Proposal and an accelerated schedule. In practice of international environmental agreement, "alternative to alternative" should be developed to avoid regrettable alternations.

  16. Archive of Historic Core Data from the Ocean Drilling Program (ODP) Legs 101-129 (Pre-JANUS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Drilling Program (ODP) operated the drilling vessel JOIDES Resolution from 1984-2003 for over 100 cruises worldwide. The ODP was funded by the U.S....

  17. Integrated bio-magnetostratigraphy of ODP Site 709 (equatorial Indian Ocean).

    Science.gov (United States)

    Villa, Giuliana; Fioroni, Chiara; Florindo, Fabio

    2015-04-01

    Over the last decade, calcareous nannofossil biostratigraphy of the lower Eocene-Oligocene sediments has shown great potential, through identification of several new nannofossil species and bioevents (e.g. Fornaciari et al., 2010; Bown and Dunkley Jones, 2012; Toffanin et al., 2013). These studies formed the basis for higher biostratigraphic resolution leading to definition of a new nannofossil biozonation (Agnini et al., 2014). In this study, we investigate the middle Eocene-lower Oligocene sediments from ODP Hole 709C (ODP Leg 115) by means of calcareous nannofossils and magnetostratigraphy. Ocean Drilling Program (ODP) Site 709 was located in the equatorial Indian Ocean and biostratigraphy has been investigated in the nineties (Okada, 1990; Fornaciari et al., 1990) while paleomagnetic data from the Initial Report provided only a poorly constrained magnetostratigraphic interpretation, thus the cored succession was dated only by means of biostratigraphy. Our goal is to test the reliability in the Indian Ocean of the biohorizons recently identified at Site 711 (Fioroni et al., in press), by means of high resolution sampling, new taxonomic updates, quantitative analyses on calcareous nannofossils allowed to increase the number of useful bioevents and to compare their reliability and synchroneity. The new magnetostratigraphic analyses and integrated stratigraphy allow also to achieve an accurate biochronology of the time interval spanning Chrons C20 (middle Eocene) and C12 (early Oligocene). In addition, this equatorial site represents an opportunity to study the carbonate accumulation history and the large fluctuations of the carbonate compensation depth (CCD) during the Eocene (e.g. Pälike et al., 2012). The investigated interval encompasses the Middle Eocene Climatic Optimum (MECO), and the long cooling trend that leads to the Oligocene glacial state. By means of our new bio-magnetostratigraphic data and paleoecological results we provide further insights on

  18. Evidence of Nicoya Ophiolite Material Drilled at ODP Site 1042

    Science.gov (United States)

    Steiger, T.; Meschede, M.; Gawlick, H.

    2005-12-01

    The convergent plate margin off Costa Rica has been intensely studied during the last two decades to understand the process of subduction along the Central American margin. Based on high- resolution 3D seismic data and results from ODP drilling, it has recently been recognized that the Costa Rican forearc wedge on the upper plate is currently undergoing active subduction erosion (Meschede et al., 1999; Ranero and von Huene, 2000) rather than tectonic accretion by underplating. The model of subduction erosion implies that the forearc wedge of the upper plate is progressively reduced at its base and that the offscraped material is transported downward into the subduction zone. Removal of material from the base of the forearc causes extensional deformation of the upper plate, which results in subsidence of the forearc wedge and leads to landward migration of the coastline. Subsidence of the Costa Rican forearc wedge has been proven by benthic foraminifera which clearly indicate subsidence from shallow water deposition about 10-12 Myr ago to the present deep sea deposition in a depth of more than 4000 m at the location of ODP Site 1042 (Meschede et al., 2001). At the base of this drill hole a breccia dated as 14 Myr old has been encountered. It contains basaltic rocks and radiolarites as components. Rocks of these types occur in the nearby Nicoya ophiolite complex at the Nicoya peninsula in a distance of about 60 km. Radiolarians found in a sample from the breccia coincide with radiolarians from the Nicoya ophiolite complex thus indicating the provenance of the breccia. We therefore argue that the breccia represents a coastal breccia formed at the coastline of the Nicoya peninsula 14 Myr ago.

  19. Data Resources for Accessing MARGINS, Ridge 2000 and ODP Data

    Science.gov (United States)

    Goodwillie, A.; Carbotte, S.; Arko, R.; O'Hara, S.; Ryan, W.; Melkonian, A.; Ferrini, V.; Weissel, R.; Bonczkowski, J.

    2007-12-01

    Web-based digital databases are being developed by a number of academic and governmental groups to improve the ability of researchers and students to access geoscience data in a convenient and user-friendly manner. With funding from the U.S. National Science Foundation, the Marine Geoscience Data System (MGDS) (http://www.marine-geo.org/) serves as the data portal for the NSF MARGINS program, providing free public access and preservation to a wide variety of marine and terrestrial data collected during MARGINS projects. The broad suite of integrated database holdings includes rock, fluid, biology and sediment samples information and station details, multibeam bathymetry and underway geophysical data, multi-channel seismics, and water column data. Seamless links point to external repositories for geodetic data (UNAVCO), and land seismic campaign data (IRIS). GeoMapApp (http://www.geomapapp.org/), an MGDS data visualization tool, supports map-based dynamic exploration of data using a multi-resolution global digital elevation model. Built-in land and marine data sets include EarthChem geochemistry, plate boundaries, DSDP/ODP core logs, earthquake events, seafloor photos, and submersible dive tracks. Users can also access land and marine data sets through OGC-compliant Web Services provided by external repositories including PetDB, UNAVCO, IRIS and NGDC. Users can generate custom maps and grids and import their own data sets and grids. A set of short, video-style online tutorials familiarises users step-by-step with GeoMapApp functionality (http://www.geomapapp.org/tutorials/). GeoMapApp is used in a number of undergraduate mini-lessons created during the MARGINS EPO workshop (April, 2007) and is the basis for two education modules hosted at SERC-Carlton (http://www.marine- geo.org/Education.html). MGDS data portal resources make available a wide variety of real scientific data from large NSF-supported research programs. Examples of accessing and manipulating a range

  20. Inhibition of p38-MAPK potentiates cisplatin-induced apoptosis via GSH depletion and increases intracellular drug accumulation in growth-arrested kidney tubular epithelial cells.

    Science.gov (United States)

    Rodríguez-García, Maria Elena; Quiroga, Adoración G; Castro, José; Ortiz, Alberto; Aller, Patricio; Mata, Felicísima

    2009-10-01

    We were interested in analyzing the regulation by mitogen-activated protein kinases (MAPKs) of cisplatin-provoked toxicity in epithelial renal tubule cell lines, when assayed under culture conditions (cell confluence plus serum deprivation), which mimic the characteristics of a nonproliferating epithelium. Under these restrictive growth conditions, cisplatin induced apoptosis with lower efficacy than in exponentially growing cells, and decreased p38-MAPK phosphorylation in NRK-52E and other (LLC-PK1, MDCK, HK2) cell lines. Moreover, cisplatin-provoked apoptosis was potentiated by cotreatment with p38-MAPK-specific inhibitors (SB203580, SB220025) or transfection with a kinase-negative mutant of MKK6, whereas c-Jun NH2-terminal kinase or extracellular signal-regulated kinase/MAPK and ERK Kinase inhibitors were ineffective. By contrast, when applied to exponentially growing cells, cisplatin stimulated p38-MAPK phosphorylation and apoptosis, was attenuated by kinase inhibitors. Treatment of confluent/serum-deprived cells with cisplatin caused mitochondrial transmembrane potential disruption and activated the mitochondrial apoptotic pathway, as indicated by the decrease in Bcl-X(L) expression, increase in Bax expression and cytochrome c release, and these effects were potentiated by cotreatment with SB203580. Treatment of confluent/serum-deprived cells with cisplatin plus SB203580 decreased the intracellular reduced glutathione (GSH) content, and increased intracellular cisplatin accumulation as well as cisplatin binding to DNA. Cotreatment with the GSH-depleting agent D,L-buthionine-R,S-sulfoximine also potentiated cisplatin-provoked apoptosis. In summary, p38-MAPK inhibition potentiates cisplatin-provoked apoptosis in growth-arrested epithelial renal tubule cells, a result that may be explained at least in part by GSH depletion and drug transport alteration.

  1. Stratospheric ozone depletion during the 1995–1996 Arctic winter: 3-D simulations on the potential role of different PSC types

    Directory of Open Access Journals (Sweden)

    J. Hendricks

    Full Text Available The sensitivity of modelled ozone depletion in the winter Arctic stratosphere to different assumptions of prevalent PSC types and PSC formation mechanisms is investigated. Three-dimensional simulations of the winter 1995/96 are performed with the COlogne Model of the Middle Atmosphere (COMMA by applying different PSC microphysical schemes. Model runs are carried out considering either liquid or solid PSC particles or a combined microphysical scheme. These simulations are then compared to a model run which only takes into account binary sulfate aerosols. The results obtained with the three-dimensional model agree with trajectory-box simulations performed in previous studies. The simulations suggest that conditions appropriate for type Ia PSC existence (T < TNAT occur over longer periods and cover larger areas when compared to conditions of potential type Ib PSC existence. Significant differences in chlorine activation and ozone depletion occur between the simulations including only either liquid or solid PSC particles. The largest differences, occurring over large spatial scales and during prolonged time periods, are modelled first, when the stratospheric temperatures stay below TNAT , but above the threshold of effective liquid particle growth and second, in the case of the stratospheric temperatures remaining below this threshold, but not falling below the ice frost point. It can be generally concluded from the present study that differences in PSC microphysical schemes can cause significant fluctuations in ozone depletion modelled for the winter Arctic stratosphere.

    Key words. Atmospheric composition and structure (aerosols and particles; cloud physics and chemistry; middle atmosphere composition and chemistry

  2. Hydrothermal cooling of the ocean crust: Insights from ODP Hole 1256D

    Science.gov (United States)

    Harris, Michelle; Coggon, Rosalind M.; Wood, Martin; Smith-Duque, Christopher E.; Henstock, Timothy J.; Teagle, Damon A. H.

    2017-03-01

    The formation of new ocean crust at mid-ocean ridges is a fundamental component of the plate tectonic cycle and involves substantial transfer of heat and mass from the mantle. Hydrothermal circulation at mid-ocean ridges is critical for the advection of latent and sensible heat from the lower crust to enable the solidification of ocean crust near to the ridge axis. The sheeted dike complex (SDC) is the critical region between the eruptive lavas and the gabbros through which seawater-derived recharge fluids must transit to exchange heat with the magma chambers that form the lower ocean crust. ODP Hole 1256D in the eastern equatorial Pacific Ocean provides the only continuous sampling of in-situ intact upper ocean crust formed at a fast spreading rate, through the SDC into the dike-gabbro transition zone. Here we exploit a high sample density profile of the Sr-isotopic composition of Hole 1256D to quantify the time-integrated hydrothermal recharge fluid flux through the SDC. Assuming kinetically limited fluid-rock Sr exchange, a fluid flux of 1.5- 3.2 ×106 kgm-2 is required to produce the observed Sr-isotopic shifts. Despite significant differences in the distribution and intensity of hydrothermal alteration and fluid/rock Sr-isotopic exchange between Hole 1256D and SDC sampled in other oceanic environments (ODP Hole 504B, Hess Deep and Pito Deep), the estimated recharge fluid fluxes at all sites are similar, suggesting that the heat flux extracted by the upper crustal axial hydrothermal system is relatively uniform at intermediate to fast spreading rates. The hydrothermal heat flux removed by fluid flow through the SDCs, is sufficient to remove only ∼20 to 60% of the available latent and sensible heat from the lower crust. Consequently, there must be additional thermal and chemical fluid-rock exchange deeper in the crust, at least of comparable size to the upper crustal hydrothermal system. Two scenarios are proposed for the potential geometry of this deeper

  3. The Effects of Acute Dopamine Precursor Depletion on the Cognitive Control Functions of Performance Monitoring and Conflict Processing: An Event-Related Potential (ERP) Study

    Science.gov (United States)

    Primosch, Mark; Leyton, Marco; Steffensen, Scott C.

    2015-01-01

    Studies using medications and psychiatric populations implicate dopamine in cognitive control and performance monitoring processes. However, side effects associated with medication or studying psychiatric groups may confound the relationship between dopamine and cognitive control. To circumvent such possibilities, we utilized a randomized, double-blind, placebo-controlled, within-subjects design wherein participants were administered a nutritionally-balanced amino acid mixture (BAL) and an amino acid mixture deficient in the dopamine precursors tyrosine (TYR) and phenylalanine (PHE) on two separate occasions. Order of sessions was randomly assigned. Cognitive control and performance monitoring were assessed using response times (RT), error rates, the N450, an event-related potential (ERP) index of conflict monitoring, the conflict slow potential (conflict SP), an ERP index of conflict resolution, and the error-related negativity (ERN) and error positivity (Pe), ERPs associated with performance monitoring. Participants were twelve males who completed a Stroop color-word task while ERPs were collected four hours following acute PHE and TYR depletion (APTD) or balanced (BAL) mixture ingestion in two separate sessions. N450 and conflict SP ERP amplitudes significantly differentiated congruent from incongruent trials, but did not differ as a function of APTD or BAL mixture ingestion. Similarly, ERN and Pe amplitudes showed significant differences between error and correct trials that were not different between APTD and BAL conditions. Findings indicate that acute dopamine precursor depletion does not significantly alter cognitive control and performance monitoring ERPs. Current results do not preclude the role of dopamine in these processes, but suggest that multiple methods for dopamine-related hypothesis testing are needed. PMID:26492082

  4. Modified crop model estimation of depleted and potential soybean yield=Modelo modificado de estimação da produtividade deplecionada e potencial da soja

    Directory of Open Access Journals (Sweden)

    Paulo Augusto Manfron

    2012-10-01

    Full Text Available Despite the great importance of soybeans in Brazil, there have been few applications of soybean crop modeling on Brazilian conditions. Thus, the objective of this study was to use modified crop models to estimate the depleted and potential soybean crop yield in Brazil. The climatic variable data used in the modified simulation of the soybean crop models were temperature, insolation and rainfall. The data set was taken from 33 counties (28 Sao Paulo state counties, and 5 counties from other states that neighbor São Paulo. Among the models, modifications in the estimation of the leaf area of the soybean crop, which includes corrections for the temperature, shading, senescence, CO2, and biomass partition were proposed; also, the methods of input for the model’s simulation of the climatic variables were reconsidered. The depleted yields were estimated through a water balance, from which the depletion coefficient was estimated. It can be concluded that the adaptation soybean growth crop model might be used to predict the results of the depleted and potential yield of soybeans, and it can also be used to indicate better locations and periods of tillage.Aplicações de modelos de previsão de produtividade na cultura da soja são muito raros. Assim, o objetivo desta pesquisa foi realizar a estimação da produtividade deplecionada e potencial da cultura de soja, usando modelos de previsão modificados. Os dados climáticos utilizados nos modelos de simulação foram a temperatura, precipitação e insolação. Os dados foram proveniente de 33 municípios (28 do estado de São Paulo, e cinco municípios de estados vizinhos. Dentre os modelos propostos modificados está a estimação da área foliar da soja, com correções para temperatura, sombreamento, senescência, CO2, partição de biomassa, bem como os métodos de simulação das variávies climáticas do “input” para o modelo. As produções deplecionadas foram estimadas através do balan

  5. Learning about ozone depletion

    Energy Technology Data Exchange (ETDEWEB)

    Crutzen, J. P. [Department of Atmospheric Chemistry, Max Planck Institute for Chemistry, Mainz, Germany; Oppenheimer M. [Woodrow Wilson School of Public and International Affairs, Department of Geosciences, Princeton University, Princeton, NJ (United States)

    2008-07-15

    Stratospheric ozone depletion has been much studied as a case history in the interaction between environmental science and environmental policy. The positive influence of science on policy is often underscored, but here we review the photochemistry of ozone in order to illustrate how scientific learning has the potential to mislead policy makers. The latter may occur particularly in circumstances where limited observations are combined with simplified models of a complex system, such as may generally occur in the global change arena. Even for the well-studied case of ozone depletion, further research is needed on the dynamics of scientific learning, particularly the scientific assessment process, and how assessments influence the development of public policy.

  6. Potentiation of arsenic trioxide-induced apoptosis by 8-bromo-7-methoxychrysin in human leukemia cells involves depletion of intracellular reduced glutathione

    Institute of Scientific and Technical Information of China (English)

    Guangfen Xiao; Xueyuan Tang; Chenjiao Yao; Chenghong Wang

    2011-01-01

    The novel chrysin analog 8-bromo-7-methoxychrysin (BrMC) has been reported to induce apoptosis of various cancer cell lines.Arsenic trioxide (ATO) treatment induces clinical remission in acute promyelocytic leukemia patients.The combination of ATO with other agents has been shown to improve therapeutic effectiveness in vitro and in vivo.In this report,the mechanism of apoptosis induced by treatment with ATO alone or in combination with BrMC was studied in U937,HL-60,and Jurkat cells.Our results demonstrated that BrMC cooperated with ATO to induce apoptosis in human leukemia cells.This co-treatment caused mitochondrial transmembrane potential dissipation and stimulated the mitochondrial apoptotic pathway,as evidenced by cytochrome c release,down-regulation of X-linked inhibitor of apoptosis (XIAP) and Bcl-XL,and up-regulation of Bax.BrMC alone or in combination with ATO,decreased Akt phosphorylation as well as intracellular reduced glutathione (GSH) content.The thiol antioxidant N-acetylcysteine and exogenous GSH restored GSH content and attenuated apoptosis induced by co-treatment with ATO plus BrMC.In contrast,the non-thiol antioxidant butylated hydroxyanisole and mannitol failed to do so.These findings suggest that GSH depletion explains at least in part the potentiation of ATO-induced apoptosis by BrMC.

  7. Tele-education Process Modelling supported by the ODP Enterprise Viewpoint Language

    NARCIS (Netherlands)

    Jones, Valerie M.; Volman, C.J.A.M.; van Sinderen, Marten J.; Widya, I.A.; Michiels, E.F.

    1997-01-01

    This paper reports on applying the ODP enterprise viewpoint in the domain of tele-education. The work is conducted as part of a research activity that aims at designing a tele-education system to support planning, execution and evaluation of dynamic distributed educational processes. We explore the

  8. Tele-education Process Modelling supported by the ODP Enterprise Viewpoint Language

    NARCIS (Netherlands)

    Volman, Cees; Jones, Val; Sinderen, van Marten; Widya, Ing; Michiels, Eddie

    1997-01-01

    This paper reports on applying the ODP enterprise viewpoint in the domain of tele-education. The work is conducted as part of a research activity that aims at designing a tele-education system to support planning, execution and evaluation of dynamic distributed educational processes. We explore the

  9. Evaluation of PAH depletion of subsurface Exxon Valdez oil residues remaining in Prince William Sound in 2007-2008 and their likely bioremediation potential

    Energy Technology Data Exchange (ETDEWEB)

    Atlas, R. [Louisville Univ., Louisville, KY (United States); Bragg, J.R. [Creative Petroleum Solutions LLC, Houston, TX (United States)

    2009-07-01

    This study examined the extent of oil weathering at the Exxon Valdez oil spill (EVOS) sites and estimated the bioremediation potential for shoreline segments by examining the depletion of total polycyclic aromatic hydrocarbons (PAHs) relative to an estimated applicability threshold of 70 per cent. The distribution of oil was examined by location and current ratios of nitrogen and non-polar oil in order to assess if biodegradation rates were nutrient-limited. The impact of sequestration on the effectiveness of bioremediation was also studied. Results of the study showed that the EVOS residues are patchy and infrequently found on sites that were heavily oiled in 1989. Only 0.4 per cent of the oil originally stranded in 1989 remained. The remaining EVOS residues are sequestered under boulder and cobble armour in areas with limited contact with flowing water. The study also showed that concentrations of nitrogen and dissolved oxygen in pore waters within strata adjacent to the sequestered oil can support biodegradation. Most remaining EVOS residues are highly weathered and biodegraded. It was concluded that nutrients added to the shorelines are unlikely to effectively contact the sequestered oil. 31 refs., 2 tabs., 14 figs.

  10. Three-dimensional distribution of gas hydrate beneath southern Hydrate Ridge: Constraints from ODP Leg 204

    Science.gov (United States)

    Trehu, A.M.; Long, P.E.; Torres, M.E.; Bohrmann, G.; Rack, F.R.; Collett, T.S.; Goldberg, D.S.; Milkov, A.V.; Riedel, M.; Schultheiss, P.; Bangs, N.L.; Barr, S.R.; Borowski, W.S.; Claypool, G.E.; Delwiche, M.E.; Dickens, G.R.; Gracia, E.; Guerin, G.; Holland, M.; Johnson, J.E.; Lee, Y.-J.; Liu, C.-S.; Su, X.; Teichert, B.; Tomaru, H.; Vanneste, M.; Watanabe, M. E.; Weinberger, J.L.

    2004-01-01

    Large uncertainties about the energy resource potential and role in global climate change of gas hydrates result from uncertainty about how much hydrate is contained in marine sediments. During Leg 204 of the Ocean Drilling Program (ODP) to the accretionary complex of the Cascadia subduction zone, we sampled the gas hydrate stability zone (GHSZ) from the seafloor to its base in contrasting geological settings defined by a 3D seismic survey. By integrating results from different methods, including several new techniques developed for Leg 204, we overcome the problem of spatial under-sampling inherent in robust methods traditionally used for estimating the hydrate content of cores and obtain a high-resolution, quantitative estimate of the total amount and spatial variability of gas hydrate in this structural system. We conclude that high gas hydrate content (30-40% of pore space or 20-26% of total volume) is restricted to the upper tens of meters below the seafloor near the summit of the structure, where vigorous fluid venting occurs. Elsewhere, the average gas hydrate content of the sediments in the gas hydrate stability zone is generally <2% of the pore space, although this estimate may increase by a factor of 2 when patchy zones of locally higher gas hydrate content are included in the calculation. These patchy zones are structurally and stratigraphically controlled, contain up to 20% hydrate in the pore space when averaged over zones ???10 m thick, and may occur in up to ???20% of the region imaged by 3D seismic data. This heterogeneous gas hydrate distribution is an important constraint on models of gas hydrate formation in marine sediments and the response of the sediments to tectonic and environmental change. ?? 2004 Published by Elsevier B.V.

  11. Late Eocene sea surface cooling of the western North Atlantic (ODP Site 647A)

    Science.gov (United States)

    Sliwinska, Kasia K.; Coxall, Helen K.; Schouten, Stefan

    2016-04-01

    The initial shift out of the early Cenozoic greenhouse and into a glacial icehouse climate occurred during the middle to late Eocene and culminated in the abrupt growth of a continental-scale ice cap on Antarctica, during an episode known as the Oligocene Isotope Event 1 (Oi-1) ˜33.7 Ma. Documenting the patterns of global and regional cooling prior to Oi-1 is crucial for understanding the driving force and feedback behind the switch in climate mode. Well-dated high-resolution temperature records, however, remain sparse and the climatic response in some of the most climatically sensitive regions of the Earth, including the high latitude North Atlantic (NA), where today large amounts of ocean heat are exchanged, are poorly known. Here we present a sea surface palaeotemperature record from the late Eocene to the early Oligocene (32.5 Ma to 35 Ma) of ODP Hole 647A based on archaeal tetraether lipids (TEX86H). The site is located in the western North Atlantic (Southern Labrador Sea) and is the most northerly located (53° N) open ocean site with a complete Eocene-Oligocene sequence which yields both calcareous and organic microfossils suitable for detailed proxy reconstructions. Our record agrees with the magnitude of temperature decrease (˜3 ° C sea surface cooling) recorded by alkenones and pollen data from the Greenland Sea, but our higher resolution study reveals that the high latitude NA cooling step occurred about 500 kyrs prior to the Oi-1 Antarctic glaciation, at around ˜34.4 Ma. This cooling can be explained by regional effects related to local NA tectonics including ocean gateways, known to have changed at the time, with potential to effect NA overturning circulation due to adjustments in the thermohaline density balance. Alternatively, the cooling itself may be due to changes in NA circulation, suggesting that global ocean circulation played a role in pre-conditioning the Earth for Antarctic glaciation.

  12. Circulating Tumor Cells Enriched by the Depletion of Leukocytes with Bi-Antibodies in Non-Small Cell Lung Cancer: Potential Clinical Application.

    Directory of Open Access Journals (Sweden)

    Jian Yin

    Full Text Available It has been considered that the detection methods for circulating tumor cells (CTCs based on epithelial cell adhesion molecule (EpCAM underestimate the number of CTCs and may miss a metastatic subpopulation with cancer stem cell (CSC properties. Therefore, we investigated EpCAM-positive and -negative CTCs in non-small cell lung cancer (NSCLC patients at different stages, assessed the clinical value of these CTCs and explored their capacity in the following CSC model.CTCs were enriched by the depletion of leukocytes with bi-antibodies using a magnetic bead separation technique and then identified by the expression of EpCAM and cytokeratin 7 and 8 using multi-parameter flow cytometry. We determined the distribution of CTCs classified by the expression of EpCAM in 46 NSCLC patients with stages I to IV, assessed the diagnostic value of these CTCs by longitudinal monitoring in 4 index patients during adjuvant therapy and characterized the stemness of these CTCs by the expression of CXCR4 and CD133 in 10 patients.EpCAM-negative (E- CTCs were detected to be significantly higher than EpCAM-positive (E+ CTCs in stage IV (p = 0.003. The patients with the percentage of E-CTCs more than 95% (r > 95% were detected to be significantly increased from 13.3% in stage I-II to 61.1% in stage IV (p = 0.006. Kaplan-Meier analysis indicated that the patients with r > 95% had significantly shorter survival time than those with r ≤ 0.95 (p = 0.041. Longitudinal monitoring of CTCs indicated that the patients with a high percentage of E-CTCs in the blood were not responsive to either chemotherapy or targeted therapy. Further characterization of CTCs revealed that a stem-like subpopulation of CXCR4+CD133+ CTCs were detected to be significantly more prevalent in E-CTCs than that in E+CTCs (p = 0.005.The enrichment of CTCs by the depletion of leukocytes with bi-antibodies is a valuable method for estimating the number of CTCs, which can be potentially applied in

  13. Potential depletion of surface water in the Colorado River and agricultural drains by groundwater pumping in the Parker-Palo Verde-Cibola area, Arizona and California

    Science.gov (United States)

    Leake, Stanley A.; Owen-Joyce, Sandra J.; Heilman, Julian A.

    2013-01-01

    Water use along the lower Colorado River is allocated as “consumptive use,” which is defined to be the amount of water diverted from the river minus the amount that returns to the river. Diversions of water from the river include surface water in canals and water removed from the river by pumping wells in the aquifer connected to the river. A complication in accounting for water pumped by wells occurs if the pumping depletes water in drains and reduces measured return flow in those drains. In that case, consumptive use of water pumped by the wells is accounted for in the reduction of measured return flow. A method is needed to understand where groundwater pumping will deplete water in the river and where it will deplete water in drains. To provide a basis for future accounting for pumped groundwater in the Parker-Palo Verde-Cibola area, a superposition model was constructed. The model consists of three layers of finite-difference cells that cover most of the aquifer in the study area. The model was run repeatedly with each run having a pumping well in a different model cell. The source of pumped water that is depletion of the river, expressed as a fraction of the pumping rate, was computed for all active cells in model layer 1, and maps were constructed to understand where groundwater pumping depletes the river and where it depletes drains. The model results indicate that if one or more drains exist between a pumping well location and the river, nearly all of the depletion will be from drains, and little or no depletion will come from the Colorado River. Results also show that if a well pumps on a side of the river with no drains in the immediate area, depletion will come from the Colorado River. Finally, if a well pumps between the river and drains that parallel the river, a fraction of the pumping will come from the river and the rest will come from the drains. Model results presented in this report may be considered in development or refinement of strategies

  14. Specifying Data Bases Management Systems by Using RM-ODP Engineering Language

    CERN Document Server

    Laassiri, Jalal; Bouhdadi, Mohamed; Orhanou, Ghizlane; Balouki, Youssef

    2011-01-01

    Distributed systems can be very large and complex. The various considerations that influence their design can result in a substantial specification, which requires a structured framework that has to be managed successfully. The purpose of the RMODP is to define such a framework. The Reference Model for Open Distributed Processing (RM-ODP) provides a framework within which support of distribution, inter-working and portability can be integrated. It defines: an object model, architectural concepts and architecture for the development of ODP systems in terms of five viewpoints. Which include an information viewpoint. Since the usage of Data bases management systems (DBMS) in complex networks is increasing considerably, we are interested, in our work, in giving DBMS specifications through the use of the three schemas (static, dynamic, invariant). The present paper is organized as follows. After a literature review, we will describe then the subset of concepts considered in this work named the database management ...

  15. Specifying Data Bases Management Systems by Using RM-ODP Engineering Language

    Directory of Open Access Journals (Sweden)

    Jalal Laassiri

    2010-05-01

    Full Text Available Distributed systems can be very large and complex. The various considerations that influence their design can result in a substantial specification, which requires a structured framework that has to be managed successfully. The purpose of the RM-ODP is to define such a framework. The Reference Model for Open Distributed Processing (RM-ODP provides a framework within which support of distribution, inter-working and portability can be integrated. It defines: an object model, architectural concepts and architecture for the development of ODP systems in terms of five viewpoints. Which include an information viewpoint. Since the usage of Data bases management systems (DBMS in complex networks is increasing considerably, we are interested, in our work, in giving DBMS specifications through the use of the three schemas (static, dynamic, invariant. The present paper is organized as follows. After a literature review, we will describe then the subset of concepts considered in this work named the database management system (DBMS object model. In the third section, we will be interested in the engineering language and DMBS structure by describing essentially DBMS objects. Finally, we will present DBMS engineering specifications and makes the connection between models and their instances. This introduces the basic form of the semantic approach we have described here.

  16. Optical Dating of Marine Sediment From ODP Core 658B - An Intercomparison With an Independent AMS 14C Chronology

    Science.gov (United States)

    Armitage, S. J.; Stokes, S.; Henderson, G.

    2004-12-01

    We demonstrate the potential of optical dating of detrital quartz silt from marine sediments via a chronological intercomparison for samples from ODP Site 658, which range in age from 0 to 140ka. ODP Site 658 is located off Cap Blanc, Mauritania. It has a high sedimentation rate (18 cm/ka), due to high regional surface productivity and large inputs of windblown Africa dust. This windblown dust provides both the substrate for optical dating and a proxy for North African aridity. The AMS 14C chronology is based on monospecific foraminiferal (Globigerinoides bulloides) samples. This is the first large-scale, systematic application of optical dating to marine sediment, and demonstrates that the technique has considerable potential for the age estimation of otherwise undateable deep-sea material. Optical dating techniques measure the total ionising radiation dose that a mineral grain has received since its last exposure to sunlight (i.e. during burial). The resulting optical age is essentially calibrated via a knowledge of the environmental dose rate, yielding the burial period. The environmental dose rate is derived from the decay of radioisotopes in the sediment (K, U and Th). In terrestrial sediments, the uranium and thorium decay chains can be assumed to be in equilibrium. In the marine realm this assumption is not valid, and unsupported uranium decay series exist on deposition. Consequently, the environmental dose rate changes with sample age. This problem was circumvented by quantifying U and Th decay series disequilibrium, using an MC-ICP-MS. The evolution of the environmental dose rate during burial was modelled, and ages for each sample calculated. The 14C and optical ages are generally in good agreement, indicating that the latter technique can provide equally robust chronologies for marine sediments. Although the maximum age attainable using optical dating is sample specific, the dose rate and luminescence characteristics of the samples analysed in this study

  17. Modeling CO2 Sequestration in Saline Aquifer and Depleted Oil Reservoirs to Evaluate Regional CO2 Sequestration Potential of Ozark Plateau Aquifer System, South-Central Kansas

    Science.gov (United States)

    Watney, W. L.; Rush, J.

    2011-12-01

    The Paleozoic-age Ozark Plateau Aquifer System (OPAS) in southern Kansas consists of a thick (>450 m) and deeply buried (>1 km) succession of Cambro-Ordovician Arbuckle Group strata (dolomite) overlain by Lower Ordovician to Lower Carboniferous-age carbonate, chert, and shale. The Arbuckle Group is a thick widespread saline aquifer in southern Kansas. A 500 meter core of the OPAS interval and immediate overlying Pennsylvanian shale caprock were cored in early 2011 in the BEREXCO Wellington KGS #1-32 well in Wellington Field, a nearly depleted oil field in Sumner County, in south-central Kansas. An exhaustive set of modern logs were run in the KGS #1-32 well including chemical, microresistivity imaging, dipole sonic, nuclear magnetic resonance, and standard porosity and resistivity wireline logs. In addition, routine and special core analyses provide vital means to calibrate these logs. Core also provide vital chemical analyses and rock samples to run flow experiments, including in situ conditions, to establish reaction kinetics of rock and connate brines with CO2. Core and logs also provide the means to calibrate a 26 km2 multicomponent 3D seismic survey that was acquired in Wellington Field in 2010. Studies of four oil fields, also part of this project, are underway in southwestern Kansas to provide additional calibration points for the western part of the regional study that covers 65,000 km2 where CO2 sequestration capacity will be measured. Several hundred deep wells have been identified to serve as type wells in the regional study area. Well logs and sample descriptions are being digitized, correlated, and mapped to define distribution of aquifers, oil reservoirs, and caprocks. Drill stem test data have been analyzed for deep wells to establish that the Arbuckle is an open aquifer connected to surface exposures 100s of km to east in central Missouri. Over 500 km2 of 3D seismic have been donated by industrial partners to aid in understanding fault and fracture

  18. HFK's en het (H)CFK-reductiebeleid in relatie tot het beleid inzake Nederlandse emissies van broeikasgassen. Scenario's voor mondiaal en Nederlands gebruik van gehydrogeneerde fluorkoolwaterstoffen en hun relatie met het broeikas-effect

    NARCIS (Netherlands)

    Olivier JGJ; Kroeze C; Matthijsen AJCM; Woerd HJ van der; LAE; LLO

    1994-01-01

    Hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs) are important substitutes for chlorofluorocarbons (CFCs) and halons. HCFCs have a lower Ozone Depleting Potential (ODP) than CFCs and halons, and are therefore considered temporary substitutes, while HFCs have zero ODP. In addition to O

  19. Photochemical properties of trans-1-chloro-3,3,3-trifluoropropene (trans-CHCl═CHCF3): OH reaction rate constant, UV and IR absorption spectra, global warming potential, and ozone depletion potential.

    Science.gov (United States)

    Orkin, Vladimir L; Martynova, Larissa E; Kurylo, Michael J

    2014-07-17

    Measurements of the rate constant for the gas-phase reactions of OH radicals with trans-1-chloro-3,3,3-trifluoropropene (trans-CHCl═CHCF3) were performed using a flash photolysis resonance-fluorescence technique over the temperature range 220-370 K. The reaction rate constant exhibits a noticeable curvature of the temperature dependence in the Arrhenius plot, which can be represented by the following expression: kt-CFP (220-370 K) = 1.025 × 10(-13) × (T/298)(2.29) exp(+384/T) cm(3 )molecule(-1) s(-1). The room-temperature rate constant was determined to be kt-CFP (298 K) = (3.29 ± 0.10) × 10(-13) cm(3) molecule(-1) s(-1), where the uncertainty includes both two standard errors (statistical) and the estimated systematic error. For atmospheric modeling purposes, the rate constant below room temperature can be represented by the following expression: kt-CFP (220-298 K) = (7.20 ± 0.46) × 10(-13) exp[-(237 ± 16)/T] cm(3) molecule(-1) s(-1). There was no difference observed between the rate constants determined at 4 kPa (30 Torr) and 40 kPa (300 Torr) at both 298 and 370 K. The UV and IR absorption cross sections of this compound were measured at room temperature. The atmospheric lifetime, global warming potential, and ozone depletion potential of trans-CHCl═CHCF3 were estimated.

  20. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); Guam, SRR; Long: 144.41784, Lat: 12.83819 (WGS84); Sensor Depth: 20.40m; Data Range: 20030929-20050908.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  1. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); PRIA, BAK; Long: -176.46025, Lat: 00.19005 (WGS84); Sensor Depth: 18.90m; Data Range: 20020201-20040122.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  2. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); PRIA, BAK; Long: -176.46025, Lat: 00.19005 (WGS84); Sensor Depth: 18.90m; Data Range: 20040123-20050123.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  3. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); NWHI, PHR; Long: -175.88112, Lat: 27.78206 (WGS84); Sensor Depth: 21.64m; Data Range: 20080923-20100913.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  4. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); MHI, KAU; Long: -159.51350, Lat: 22.21593 (WGS84); Sensor Depth: 15.24m; Data Range: 20060914-20070420.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  5. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); Guam, SRR; Long: 144.41778, Lat: 12.83819 (WGS84); Sensor Depth: 20.42m; Data Range: 20051007-20070508.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  6. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); PRIA, BAK; Long: -176.46012, Lat: 00.18994 (WGS84); Sensor Depth: 18.80m; Data Range: 20060131-20080209.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  7. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); Guam, SRR; Long: 144.41778, Lat: 12.83819 (WGS84); Sensor Depth: 20.42m; Data Range: 20051007-20070121.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  8. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); NWHI, MID; Long: -177.42975, Lat: 28.23182 (WGS84); Sensor Depth: 28.96m; Data Range: 20080929-20091007.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  9. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); AMSM, SWA; Long: -171.09092, Lat: -11.05848 (WGS84); Sensor Depth: 15.00m; Data Range: 20020227-20040118.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  10. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); PRIA, BAK; Long: -176.46025, Lat: 00.19005 (WGS84); Sensor Depth: 18.90m; Data Range: 20020201-20031215.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  11. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); PRIA, JAR; Long: -160.01553, Lat: -00.37917 (WGS84); Sensor Depth: 15.00m; Data Range: 20020310-20031209.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  12. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); NWHI, NEC; Long: -164.71230, Lat: 23.56800 (WGS84); Sensor Depth: 25.00m; Data Range: 20030714-20050410.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  13. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); NWHI, NEC; Long: -164.71230, Lat: 23.56800 (WGS84); Sensor Depth: 25.00m; Data Range: 20020911-20030714.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  14. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); NWHI, PHR; Long: -175.88112, Lat: 27.78204 (WGS84); Sensor Depth: 21.34m; Data Range: 20060922-20070805.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  15. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); PRIA, BAK; Long: -176.46025, Lat: 00.19005 (WGS84); Sensor Depth: 18.90m; Data Range: 20040123-20060130.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  16. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); PRIA, BAK; Long: -176.46012, Lat: 00.18994 (WGS84); Sensor Depth: 19.81m; Data Range: 20080210-20100130.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  17. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); NWHI, PHR; Long: -175.88110, Lat: 27.78209 (WGS84); Sensor Depth: 21.34m; Data Range: 20070805-20080922.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  18. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); Guam, SRR; Long: 144.41784, Lat: 12.83819 (WGS84); Sensor Depth: 20.40m; Data Range: 20030928-20050723.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  19. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); NWHI, MID; Long: -177.42972, Lat: 28.23193 (WGS84); Sensor Depth: 29.26m; Data Range: 20041004-20060916.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  20. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); PRIA, JAR; Long: -160.01547, Lat: -00.37915 (WGS84); Sensor Depth: 14.60m; Data Range: 20040326-20060123.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  1. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); PRIA, JAR; Long: -160.01545, Lat: -00.37912 (WGS84); Sensor Depth: 15.24m; Data Range: 20060320-20080326.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  2. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); NWHI, MID; Long: -177.42977, Lat: 28.23180 (WGS84); Sensor Depth: 29.26m; Data Range: 20060916-20080928.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  3. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); MHI, KAU; Long: -159.51350, Lat: 22.21593 (WGS84); Sensor Depth: 15.24m; Data Range: 20060914-20070421.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  4. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); NWHI, PHR; Long: -175.88112, Lat: 27.78204 (WGS84); Sensor Depth: 21.34m; Data Range: 20060922-20070805.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  5. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); PRIA, JAR; Long: -160.01553, Lat: -00.37917 (WGS84); Sensor Depth: 15.00m; Data Range: 20020311-20040325.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  6. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); PRIA, JAR; Long: -160.01547, Lat: -00.37915 (WGS84); Sensor Depth: 14.60m; Data Range: 20040327-20051016.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  7. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); NWHI, PHR; Long: -175.88110, Lat: 27.78209 (WGS84); Sensor Depth: 21.34m; Data Range: 20070806-20070912.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  8. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); NWHI, MID; Long: -177.42977, Lat: 28.23180 (WGS84); Sensor Depth: 29.26m; Data Range: 20060917-20080928.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  9. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); PRIA, BAK; Long: -176.46012, Lat: 00.18994 (WGS84); Sensor Depth: 19.81m; Data Range: 20080209-20100206.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  10. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); PRIA, JAR; Long: -160.01540, Lat: -00.37916 (WGS84); Sensor Depth: 14.63m; Data Range: 20080326-20100401.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  11. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); NWHI, KUR; Long: -178.37780, Lat: 28.42970 (WGS84); Sensor Depth: 27.70m; Data Range: 20020923-20030804.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  12. CRED Ocean Data Platform (ODP), Temperature and Conductivity Recorder (SBE37); NWHI, NEC; Long: -164.71215, Lat: 23.56792 (WGS84); Sensor Depth: 24.90m; Data Range: 20050416-20060903.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  13. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); AMSM, SWA; Long: -171.09092, Lat: -11.05848 (WGS84); Sensor Depth: 15.00m; Data Range: 20020227-20021207.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  14. CRED Ocean Data Platform (ODP), Acoustic Doppler Profiler (ADP); NWHI, NEC; Long: -164.71215, Lat: 23.56792 (WGS84); Sensor Depth: 24.90m; Data Range: 20050411-20060903.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Data Platform (ODP) is placed on the sea floor to measure water current profiles, waves, temperature and conductivity. The ODP consists of an upward...

  15. Cryoinsulation Material Development to Mitigate Obsolescence Risk for Global Warming Potential Foams

    Science.gov (United States)

    Protz, Alison; Bruyns, Roland; Nettles, Mindy

    2015-01-01

    Cryoinsulation foams currently being qualified for the Space Launch System (SLS) core stage are nonozone- depleting substances (ODP) and are compliant with current environmental regulations. However, these materials contain the blowing agent HFC-245fa, a hydrofluorocarbon (HFC), which is a Global Warming Potential (GWP) substance. In August 2014, the Environmental Protection Agency (EPA) proposed a policy change to reduce or eliminate certain HFCs, including HFC-245fa, in end-use categories including foam blowing agents beginning in 2017. The policy proposes a limited exception to allow continued use of HFC and HFC-blend foam blowing agents for military or space- and aeronautics-related applications, including rigid polyurethane spray foams, but only until 2022.

  16. Insights into magmatic processes and hydrothermal alteration of in situ superfast spreading ocean crust at ODP/IODP site 1256 from a cluster analysis of rock magnetic properties

    NARCIS (Netherlands)

    Dekkers, Mark J.|info:eu-repo/dai/nl/073463744; Heslop, David; Herrero-Bervera, Emilio; Acton, Gary; Krasa, David

    2014-01-01

    We analyze magnetic properties from Ocean Drilling Program (ODP)/Integrated ODP (IODP) Hole 1256D (6°44.1' N, 91°56.1' W) on the Cocos Plate in ∼15.2 Ma oceanic crust generated by superfast seafloor spreading, the only drill hole that has sampled all three oceanic crust layers in a tectonically undi

  17. Insights into magmatic processes and hydrothermal alteration of in situ superfast spreading ocean crust at ODP/IODP site 1256 from a cluster analysis of rock magnetic properties

    NARCIS (Netherlands)

    Dekkers, Mark J.; Heslop, David; Herrero-Bervera, Emilio; Acton, Gary; Krasa, David

    2014-01-01

    We analyze magnetic properties from Ocean Drilling Program (ODP)/Integrated ODP (IODP) Hole 1256D (6°44.1' N, 91°56.1' W) on the Cocos Plate in ∼15.2 Ma oceanic crust generated by superfast seafloor spreading, the only drill hole that has sampled all three oceanic crust layers in a tectonically undi

  18. Technical note: Late Pliocene age control and composite depths at ODP Site 982, revisited

    Directory of Open Access Journals (Sweden)

    N. Khélifi

    2012-01-01

    Full Text Available Ocean Drilling Program (ODP Site 982 provided a key sediment section at Rockall Plateau for reconstructing northeast Atlantic paleoceanography and monitoring benthic δ18O stratigraphy over the late Pliocene to Quaternary onset of major Northern Hemisphere glaciation. A renewed hole-specific inspection of magnetostratigraphic reversals and the addition of epibenthic δ18O records for short Pliocene sections in holes 982A, B, and C, crossing core breaks in the δ18O record published for Hole 982B, now imply a major revision of composite core depths. After tuning to the orbitally tuned reference record LR04, the new composite δ18O record results in a hiatus, where the Kaena magnetic subchron might have been lost, and in a significant age reduction for all proxy records by 130 to 20 ky over the time span 3.2–2.7 million years ago (Ma. Our study demonstrates the general significance of reliable composite-depth scales and δ18O stratigraphies in ODP sediment records for generating ocean-wide correlations in paleoceanography. The new concept of age control makes the late Pliocene trends in SST (sea surface temperature and atmospheric pCO2 at Site 982 more consistent with various paleoclimate trends published from elsewhere in the North Atlantic.

  19. Intrinsic Depletion or Not

    DEFF Research Database (Denmark)

    Klösgen, Beate; Bruun, Sara; Hansen, Søren;

      The presence of a depletion layer of water along extended hydrophobic interfaces, and a possibly related formation of nanobubbles, is an ongoing discussion. The phenomenon was initially reported when we, years ago, chose thick films (~300-400Å) of polystyrene as cushions between a crystalline...... giving rise to depletion layers, and the mechanisms and border conditions that control their presence and extension require still clarification. Recently, careful systematic reflectivity experiments were re-done on the same system. No depletion layers were found, and it was conjectured that the whole...

  20. Integral Equation Method for the Determination of the Depletion Potential Between Two Colloidal Particles%用积分方程方法决定胶粒之间的空耗势

    Institute of Scientific and Technical Information of China (English)

    周世琦; 张晓琪; 向贤伟; 向红

    2004-01-01

    Binary components Ornstein-Zernike integral equation with the concentration of large particle component being set to zero was employed to study the depletion potential behavior between two large neutral colloid particles (modeled as hard spheres) immersed in a sea of small neutral solvent particles. The prediction for the depletion potential behavior compared well with simulation data and experimental data available in the literature. It is found that the Hansen-Verlet one phase criterion, based on the effective one component system with the present depletion potential, for the freezing transition is completely not suitable for the real binary components system. It is disclosed that the unsuitability is due to the volume term of the solid phase and liquid phase which can not be treated self-consistently in the Hansen-Verlet one phase criterion.%用硬球模中性胶体粒子,数值求解双组分Ornstein-Zernike积分方程(当大的中性胶体粒子的浓度为零时),用来决定悬浮在溶剂(用小的硬球模拟)中两个胶粒之间的空耗势.所预言的空耗势与文献的模拟数据和实验数据能很好地符合.研究发现,基于空耗势的有效一组分Hansen-Verlet 一相相变标准完全不能预言双组分系统的液-固相变.讨论了导致这种现象的原因: Hansen-Verlet 一相相变标准不能自冾地处理有效一组分系统中固相与液相的体积能.

  1. Addressing Ozone Layer Depletion

    Science.gov (United States)

    Access information on EPA's efforts to address ozone layer depletion through regulations, collaborations with stakeholders, international treaties, partnerships with the private sector, and enforcement actions under Title VI of the Clean Air Act.

  2. Vortioxetine dose-dependently reverses 5-HT depletion-induced deficits in spatial working and object recognition memory: a potential role for 5-HT1A receptor agonism and 5-HT3 receptor antagonism.

    Science.gov (United States)

    du Jardin, Kristian Gaarn; Jensen, Jesper Bornø; Sanchez, Connie; Pehrson, Alan L

    2014-01-01

    We previously reported that the investigational multimodal antidepressant, vortioxetine, reversed 5-HT depletion-induced memory deficits while escitalopram and duloxetine did not. The present report studied the effects of vortioxetine and the potential impact of its 5-HT1A receptor agonist and 5-HT3 receptor antagonist properties on 5-HT depletion-induced memory deficits. Recognition and spatial working memory were assessed in the object recognition (OR) and Y-maze spontaneous alternation (SA) tests, respectively. 5-HT depletion was induced in female Long-Evans rats using 4-cholro-DL-phenylalanine methyl ester HCl (PCPA) and receptor occupancies were determined by ex vivo autoradiography. Rats were acutely dosed with vortioxetine, ondansetron (5-HT3 receptor antagonist) or flesinoxan (5-HT1A receptor agonist). The effects of chronic vortioxetine administration on 5-HT depletion-induced memory deficits were also assessed. 5-HT depletion reliably impaired memory performance in both the tests. Vortioxetine reversed PCPA-induced memory deficits dose-dependently with a minimal effective dose (MED) ≤0.1mg/kg (∼80% 5-HT3 receptor occupancy; OR) and ≤3.0mg/kg (5-HT1A, 5-HT1B, 5-HT3 receptor occupancy: ∼15%, 60%, 95%) in SA. Ondansetron exhibited a MED ≤3.0μg/kg (∼25% 5-HT3 receptor occupancy; OR), but was inactive in the SA test. Flesinoxan had a MED ≤1.0mg/kg (∼25% 5-HT1A receptor occupancy; SA); only 1.0mg/kg ameliorated deficits in the NOR. Chronic p.o. vortioxetine administration significantly improved memory performance in OR and occupied 95%, 66%, and 9.5% of 5-HT3, 5-HT1B, and 5-HT1A receptors, respectively. Vortioxetine's effects on SA performance may involve 5-HT1A receptor agonism, but not 5-HT3 receptor antagonism, whereas the effects on OR performance may involve 5-HT3 receptor antagonism and 5-HT1A receptor agonism. Copyright © 2013 Elsevier B.V. and ECNP. All rights reserved.

  3. Coccolithophore export production during the last deglaciation at ODP Site 1089 (Southern Ocean)

    Science.gov (United States)

    Balestrieri, Chiara; Ziveri, Patrizia; Mortyn, Peter Graham; Fornaciari, Eliana; Agnini, Claudia

    2017-04-01

    In order to assess the Southern Ocean carbonate budget change during the last deglaciation we evaluated the significance of calcification changes observed in calcareous nannofossil assemblages. In particular, we analysed coccolithophore assemblages from TNO57-21, a site survey core drilled as part of ODP Site 1089 (40°57'S; 9°53'E, 4620 m water depth), over the last 25 ky in the Subantarctic South Atlantic. This region is characterized by strong hydrographic gradients and ODP Site 1089 is optimally located in order to monitor the evolution of the Subtropical Front and Subpolar Front and the Agulhas Current (Flores et al., 2003) through time. The mean sedimentation rate is in the range of 15-20 cm/kyr, and the recovery of coccolith-bearing sediments provides a powerful tool to study deep-sea carbonate export production at high-resolution. Much of the CO2 drawdown from the atmosphere has been proposed to be stored into the deep ocean but evidence for increased carbon storage are still elusive (Martínez- Botí et al., 2015). Here, we present data on the Florisphaera profunda index and CaCO3 concentrations per gram of dry sediment, which were used to intepret the productivity trend during the last 25 kyr. These data clearly show a decrease in carbonate production throughout the last deglaciation. Moreover, we have calculated the Calcidiscus leptoporus-Emiliania huxleyi dissolution index (CEX'), which suggests a strong link between increasing coccolith dissolution and the evolution of the bottom water mass dynamics during Termination 1 (TI). Finally, mass estimations of the coccolith carbonate allow us to assess the role of each species as carbonate producers across this time span. These results reveal that during the last 25 ky the productivity was influenced by the mid-latitude westerlies, the study site was bathed by different bottom water masses, and was affected by a shoaling of the lysocline during T1 and the Holocene. References Flores J-A., Marino M., Sierro

  4. Climate variability and long-term expansion of peat lands in Arctic Norway during the late Pliocene (ODP Site 642, Norwegian Sea)

    Science.gov (United States)

    Panitz, Sina; Salzmann, Ulrich; Risebrobakken, Bjorg; De Schepper, Stijn; Pound, Matthew; Bachem, Paul

    2016-04-01

    We present the first high resolution reconstruction of vegetation and climate change in northern Norway between 3.6-3.14 Ma based on pollen assemblages in the marine sediments of ODP Hole 642B, Norwegian Sea (67°N). During the late Pliocene vegetation alternated between cool temperate forests during warmer-than-present intervals and boreal forest similar to today during cooler intervals. The northern boundary of the deciduous to mixed forest zone was displaced at least 4-8° further north and warmest month temperatures were 6-14.5°C higher than present during warm phases. Diverse cool temperate deciduous to mixed forests grew under warm climatic conditions in the lowlands of the Scandinavian mountains during the earliest late Pliocene (c. 3.6-3.47 Ma). A distinct cooling event at c. 3.47 Ma led to the predominance of boreal forest and the development of open, low alpine environments. The cooling culminated around 3.3 Ma, coinciding with Marine Oxygen Isotope Stage (MIS) M2. After c. 3.29 Ma a high variability of climate is indicated by the repeated expansion of forests and peat lands during warmer and cooler periods, respectively. Climate progressively cooled after 3.18 Ma, resembling climatic conditions during MIS M2. A long-term cooling is expressed by an expansion of Sphagnum peat lands that potentially contributed to the decline in atmospheric CO2-concentration at the end of the Piacenzian warm period. Correlations with other Northern Hemisphere records suggest hemisphere-wide effects of climate changes. Late Pliocene vegetation changes will be compared to alkenone-based sea surface temperature reconstructions and dinoflagellate cyst assemblage changes for ODP Hole 642B.

  5. Specification and Verification of Uplink Framework for Application of Software Engineering using RM-ODP

    CERN Document Server

    Salahddine, Krit; Said, El Hajji

    2012-01-01

    This paper present a survey and discussion of the Reference Model for Open Distributed Processing (RM-ODP) viewpoints; oriented approaches to requirements engineering viewpoint and a presentation of new work in the application wireless mobile phone, this area which has been designed with practical application using the Unified Modelling Language (UML)/VHDL_AMS (VHSIC Hardware Description Language Analog and Mixed-Signal). We mainly focus on rising and fulling time, action, uplink behaviour constraints (sequentiality, non determinism and concurrency constraints).We discuss the practical problems of introducing viewpoint; oriented requirements engineering into industrial software engineering practice and why these have prevented the widespread use of existing approaches. The goal of this article is to check the uplink path using the MIC (Microphone amplifier) with all analog inputs, and check the amplifier gain. This paper provides an example of using the Uplink Framework to build a comprehensive, good solution...

  6. Measurements of daily urinary uranium excretion in German peacekeeping personnel and residents of the Kosovo region to assess potential intakes of depleted uranium (DU)

    Energy Technology Data Exchange (ETDEWEB)

    Oeh, U. [GSF-National Research Center for Environment and Health, Institute of Radiation Protection, 85764 Neuherberg (Germany)]. E-mail: uwe.oeh@gsf.de; Priest, N.D. [Middlesex University, School of Health and Social Sciences, Queensway, Enfield, EN3 4SA (United Kingdom); Roth, P. [GSF-National Research Center for Environment and Health, Institute of Radiation Protection, 85764 Neuherberg (Germany); Ragnarsdottir, K.V. [University of Bristol, Department of Earth Sciences, Bristol, BS8 1RJ (United Kingdom); Li, W.B. [GSF-National Research Center for Environment and Health, Institute of Radiation Protection, 85764 Neuherberg (Germany); Hoellriegl, V. [GSF-National Research Center for Environment and Health, Institute of Radiation Protection, 85764 Neuherberg (Germany); Thirlwall, M.F. [Royal Holloway University of London, Department of Geology, Egham, TW20 0EX (United Kingdom); Michalke, B. [GSF-National Research Center for Environment and Health, Institute of Radiation Protection, 85764 Neuherberg (Germany); Giussani, A. [GSF-National Research Center for Environment and Health, Institute of Radiation Protection, 85764 Neuherberg (Germany); Universita degli Studi di Milano, Dipartimento di Fisica, and INFN, Sezione di Milano, 20133 Milan (Italy); Schramel, P. [GSF-National Research Center for Environment and Health, Institute of Radiation Protection, 85764 Neuherberg (Germany); Paretzke, H.G. [GSF-National Research Center for Environment and Health, Institute of Radiation Protection, 85764 Neuherberg (Germany)

    2007-08-01

    Following the end of the Kosovo conflict, in June 1999, a study was instigated to evaluate whether there was a cause for concern of health risk from depleted uranium (DU) to German peacekeeping personnel serving in the Balkans. In addition, the investigations were extended to residents of Kosovo and southern Serbia, who lived in areas where DU ammunitions were deployed. In order to assess a possible DU intake, both the urinary uranium excretion of volunteer residents and water samples were collected and analysed using inductively coupled plasma-mass spectrometry (ICP-MS). More than 1300 urine samples from peacekeeping personnel and unexposed controls of different genders and age were analysed to determine uranium excretion parameters. The urine measurements for 113 unexposed subjects revealed a daily uranium excretion rate with a geometric mean of 13.9 ng/d (geometric standard deviation (GSD) = 2.17). The analysis of 1228 urine samples from the peacekeeping personnel resulted in a geometric mean of 12.8 ng/d (GSD = 2.60). It follows that both unexposed controls and peacekeeping personnel excreted similar amounts of uranium. Inter-subject variation in uranium excretion was high and no significant age-specific differences were found. The second part of the study monitored 24 h urine samples provided by selected residents of Kosovo and adjacent regions of Serbia compared to controls from Munich, Germany. Total uranium and isotope ratios were measured in order to determine DU content. {sup 235}U/{sup 238}U ratios were within {+-} 0.3% of the natural value, and {sup 236}U/{sup 238}U was less than 2 x 10{sup -7}, indicating no significant DU in any of the urine samples provided, despite total uranium excretion being relatively high in some cases. Measurements of ground and tap water samples from regions where DU munitions were deployed did not show any contamination with DU, except in one sample. It is concluded that both peacekeeping personnel and residents serving or

  7. Using DSDP/ODP/IODP core photographs and digital images in the classroom

    Science.gov (United States)

    Pereira, Hélder; Berenguer, Jean-Luc

    2017-04-01

    Since the late 1960's, several scientific ocean drilling programmes have been uncovering the history of the Earth hidden beneath the seafloor. The adventure began in 1968 with the Deep Sea Drilling Project (DSDP) and its special drill ship, the Glomar Challenger. The next stage was the Ocean Drilling Program (ODP) launched in 1985 with a new drill ship, the JOIDES Resolution. The exploration of the ocean seafloor continued, between 2003 and 2013, through the Integrated Ocean Drilling Program (IODP). During that time, in addition to the JOIDES Resolution, operated by the US, the scientists had at their service the Chikyu, operated by Japan, and Mission-Specific-Platforms, funded and implemented by the European Consortium for Ocean Research Drilling. Currently, scientific ocean drilling continues through the collaboration of scientists from 25 nations within the International Ocean Discovery Program (IODP). Over the last 50 years, the scientific ocean drilling expeditions conducted by these programmes have drilled and cored more than 3500 holes. The numerous sediment and rock samples recovered from the ocean floor have provided important insight on the active biological, chemical, and geological processes that have shaped the Earth over millions of years. During an expedition, once the 9.5-meter long cores arrive from the seafloor, the technicians label and cut them into 1.5-meter sections. Next, the shipboard scientists perform several analysis using non-destructive methods. Afterward, the technicians split the cores into two halves, the "working half", which scientists sample and use aboard the drilling platform, and the "archive half", which is kept in untouched condition after being visually described and photographed with a digital imaging system. The shipboard photographer also takes several close-up pictures of the archive-half core sections. This work presents some examples of how teachers can use DSDP/ODP/IODP core photographs and digital images, available

  8. Combined Studies of ODP log Data and Seismic Reflection Data at Southern Hydrate Ridge

    Science.gov (United States)

    Papenberg, C. A.; Petersen, J.; Klaeschen, D.

    2003-12-01

    In August 2002 Ocean Drilling Program (ODP) Leg 204 (Hydrate Ridge) provided essential borehole data to complement recent seismic studies at Hydrate Ridge to correlate amplitude analysis investigations and to constrain previous results. Seismic data was acquired during cruise SO-150 in September 2000 on the German RV SONNE, aiming at qualitative and quantitative estimates of free gas and gas hydrates within the sediments across Hydrate Ridge. Hydrate Ridge is part of the accretionary complex and is characterized by the presence of extensive gas hydrates, causing a prominent Bottom Simulating Reflector (BSR) in marine seismic records. Several seismic in- and crosslines were shot across the ridge to map the spatial distribution of the BSR. Wide angle reflection data of narrowly spaced Ocean Bottom Seismometers (OBS) allow frequency dependent amplitude variations with offset (AVO) investigations. Seismic reflection data, recorded simultaneously with a single channel surface and deep tow streamer completed the data set. The usage of different sources during acquisition provided additional information of the frequency response of the BSR signature. This data set was used to study the complex seismic behaviour of such gas hydrate environments in detail. The borehole data, collected during ODP Leg 204, now improve recent seismic investigations and support previous results. Within the COLIBRI project log information (Vp, Vs and density) was used for forward modeling to combine seismic investigations with new borehole data. The P wave velocity model of a traveltime inversion and AVO analysis of the seismic OBS sections suggest rather low quantities of gas hydrate or at least the lack of massive hydrate zones. Shear wave phases, identified in the seismic OBS sections, refer to slow S wave velocities in the upper sediment layers above the BSR, which support a model with small amounts of hydrate or patchy hydrate zones within the upper sediments.

  9. Ship Heave Effects on ODP Drilling Dynamics: analysis of MWD data in the Nankai Trough

    Science.gov (United States)

    Myers, G.; Gaillot, P.; Goldberg, D.

    2001-12-01

    Characterization of the dynamics of ship heave and its effect on downhole drilling and coring has been long sought after in the Ocean Drilling Program. Operating in the Nankai trough region, the JOIDES Resolution acquired new data of downhole parameters using commercially-available Measurement-While-Drilling (MWD) tools at two drilling sites. Our objective during ODP Leg 196 was to record weight-on-bit, rate of penetration, torque, and pump pressure near the bit as drilling proceeded. Digital instruments installed on the rig floor simultaneously acquired vital surface information of the drilling parameters. Although the sampling rate afforded by the downhole tools is insufficient to resolve wave periods of 8-10 seconds, longer wavelength changes are clearly observed. Wavelet transform analysis was used to eliminate window length restrictions with conventional Fourier analysis and to retain the time-specific information recorded in the raw signal. The integration of the uphole and downhole data sets and subsequent wavelet analysis show less variation with heave than in previous experiments near Antarctica where sea states reached 4 meters. The ratio of surface to downhole weight-on-bit for the two data sets in the >30 second spectral window varies systematically with changes in sea state, water depth, pipe depth and driller input. We are thus able to study the effects and drilling dynamics in changing sea states and in water depths up to 4800 meters and to evaluate the operation of the shipboard heave compensation systems. As a result of these analyses, ODP is deriving an empirical approach for operational use to describe downhole and uphole drilling parameters under a variety of conditions and in different geological environments.

  10. Intrinsic Depletion or Not

    DEFF Research Database (Denmark)

    Klösgen, Beate; Bruun, Sara; Hansen, Søren;

    with an AFM (2).    The intuitive explanation for the depletion based on "hydrophobic mismatch" between the obviously hydrophilic bulk phase of water next to the hydrophobic polymer. It would thus be an intrinsic property of all interfaces between non-matching materials. The detailed physical interaction path......  The presence of a depletion layer of water along extended hydrophobic interfaces, and a possibly related formation of nanobubbles, is an ongoing discussion. The phenomenon was initially reported when we, years ago, chose thick films (~300-400Å) of polystyrene as cushions between a crystalline...

  11. Potential impacts of CF3I on ozone as a replacement for CF3Br in aircraft applications

    Directory of Open Access Journals (Sweden)

    D. Youn

    2006-06-01

    Full Text Available Iodotrifluoromethane (CF3I has been considered to be a candidate replacement for bromotrifluoromethane (CF3Br, which is used in aircraft for fuel inerting and for fire fighting. In this study, the chemical effects of aircraft-released CF3I on atmospheric ozone were examined with the University of Illinois at Urbana-Champaign two-dimensional chemical-radiative-transport (UIUC 2-D CRT model. Using an earlier estimate of the aircraft emission profile for tank inerting in military aircraft, the resulting equivalent Ozone Depletion Potentials (ODPs for CF3I were in the range of 0.07 to 0.25. As a sensitivity study, we also analyzed CF3I emissions associated with fuel inerting if it were to occur at lower altitudes using an alternative estimate. The model calculations of resulting effects on ozone for this case gave ODPs≤0.05. Furthermore, through interactions with the National Institute of Standards and Technology (NIST, we analyzed the potential effects on ozone resulting from using CF3I in fire fighting connected with engine nacelle and auxiliary power unit applications. The scenarios evaluated using the NIST estimate suggested that the ODPs obtained by assuming aircraft flights occurring in several different latitude regions of the Northern Hemisphere are extremely low. According to the model calculation, the altitude where CF3I is released from aircraft is a dominant factor in its ozone depletion effects. On the assumption that the CF3I emission profile is representative of actual release characteristics, aircraft-released CF3I has much lower impacts on the ozone layer and can be a qualified substitute of CF3Br in engine nacelles.

  12. Potential impacts of CF3I on ozone as a replacement for CF3Br in aircraft applications

    Directory of Open Access Journals (Sweden)

    Y. Li

    2006-01-01

    Full Text Available Iodotrifluoromethane (CF3I has been considered to be a candidate replacement for bromotrifluoromethane (CF3Br, which is used in aircraft for fuel inerting and for fire fighting. In this study, the chemical effects of aircraft-released CF3I on atmospheric ozone were examined with the University of Illinois at Urbana-Champaign two-dimensional chemical-radiative-transport (UIUC 2-D CRT model. Using an earlier estimate of the aircraft emission profile for tank inerting in military aircraft, the resulting equivalent Ozone Depletion Potentials (ODPs for CF3I were in the range of 0.07 to 0.25. As a sensitivity study, we also analyzed CF3I emissions associated with fuel inerting if it were to occur at lower altitudes using an alternative estimate. The model calculations of resulting effects on ozone for this case gave ODPs≤0.05. Furthermore, through interactions with the National Institute of Standards and Technology (NIST, we analyzed the potential effects on ozone resulting from using CF3I in fire fighting connected with engine nacelle and auxiliary power unit applications. The scenarios evaluated using the NIST estimate suggested that the ODPs obtained by assuming aircraft flights occurring in several different latitude regions of the Northern Hemisphere are extremely low. According to the model calculation, the altitude where CF3I is released from aircraft is a dominant factor in its ozone depletion effects. On the assumption that the CF3I emission profile is representative of actual release characteristics, aircraft-released CF3I has much lower impacts than CF3Br.

  13. Neogene oxygen isotopic stratigraphy, ODP Site 1148,northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Quanhong

    2001-01-01

    [1]Miller, K. G., Fairbank, R. G., Mountain, G. S., Tertiary oxygen isotope synthesis, sea level history, and continental mar gin erosion, Paleoceanogr., 1987, 2(1): 1-19.[2]Savin, S. M., Keller, G., Douglas, R. G. et al., Miocene benthic foraminiferal isotopic records: A synthesis, Mar. Micro paleont., 1981, 6: 423-450.[3]Jian Zhimin, Chen Minben, Lin Huiling et al., Stepwise paleoceanographic changes during the last deglaciation in the southern South China Sea: the records of isotopes and microfossils, Science in China, Ser. D, 1998, 41 (2): 187-124.[4]Jian Zhimin, Stable isotopic evidences of the glacial deep water properties in the South China Sea, Science in China, Ser.D, 1998, 41(4): 337-344.[5]Zhao Quanhong, Wang Pinxian, Progress in Quaternary paleoceanography of the South China Sea: A review, Quaternary Sciences (in Chinese with English abstract), 1999, 6: 481-501.[6]Woodruff, F., Douglas, R. G., Response of deep-sea benthic Foraminifera to Miocene paleoclimatic events, DSDP Site 289,Mar. Micropaleont., 1981, 6: 617-632.[7]Kennett, J. P., Miocene to early Pliocene oxygen and carbon isotope stratigraphy of the Southwest Pacific, DSDP Leg 90,in Init. Rep. DSDP (eds. Kennett, J. P., von der Borch, C. C.), 1986, 90(pt.2):1383-1411.[8]Vincent, E., Killingley, J. S., Oxygen and carbon isotope record for the Early and Middle Miocene in the central equatorial Pacific (Leg 85) and paleoceanographic implications, in Init. Rep. DSDP (eds. Mayer, L., Theyer, F., Barron, A. J. et al.),1985, 85: 749-769.[9]Woodruff, F., Savin, S. M., Abel, L., Miocene benthic foraminifer oxygen and carbon isotopes, Site 709, Indian Ocean, in Proc. ODP Sci. Res. (eds. Duncan, R. A., Backman, J., Peterson, L. C. et al.), 1990, 115:519-528.[10]Vincent, E., Berger, W. H., Carbon dioxide and polar cooling in the Miocene: The Monterey hypothesis, AGU, Washing ton, D.C., Geophys. Monogr., 1985, 32: 455-468.[11]Miller, K. G., Wright, J. D., Fairbanks

  14. Evidence of Himalayan erosional event at approx. 0.5 Ma from a sediment core from the equatorial Indian Ocean in the vicinityof ODP Leg 116 sites

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Gupta, S.M.; Mislankar, P.G.; Rao, B.R.; Parthiban, G.; Roelandts, I.; Patil, S.K.

    A sediment core collected from an area _100 miles south of the ODP Leg 116 (distal Bengal Fan) in the equatorial Indian Ocean was investigated for microfossils, mineralogy, mineral chemistry, magnetic susceptibility, grain size, major, minor...

  15. Depletion of intense fields

    CERN Document Server

    Seipt, D; Marklund, M; Bulanov, S S

    2016-01-01

    The interaction of charged particles and photons with intense electromagnetic fields gives rise to multi-photon Compton and Breit-Wheeler processes. These are usually described in the framework of the external field approximation, where the electromagnetic field is assumed to have infinite energy. However, the multi-photon nature of these processes implies the absorption of a significant number of photons, which scales as the external field amplitude cubed. As a result, the interaction of a highly charged electron bunch with an intense laser pulse can lead to significant depletion of the laser pulse energy, thus rendering the external field approximation invalid. We provide relevant estimates for this depletion and find it to become important in the interaction between fields of amplitude $a_0 \\sim 10^3$ and electron bunches with charges of the order of nC.

  16. Depletion of Intense Fields

    Science.gov (United States)

    Seipt, D.; Heinzl, T.; Marklund, M.; Bulanov, S. S.

    2017-04-01

    The interaction of charged particles and photons with intense electromagnetic fields gives rise to multiphoton Compton and Breit-Wheeler processes. These are usually described in the framework of the external field approximation, where the electromagnetic field is assumed to have infinite energy. However, the multiphoton nature of these processes implies the absorption of a significant number of photons, which scales as the external field amplitude cubed. As a result, the interaction of a highly charged electron bunch with an intense laser pulse can lead to significant depletion of the laser pulse energy, thus rendering the external field approximation invalid. We provide relevant estimates for this depletion and find it to become important in the interaction between fields of amplitude a0˜1 03 and electron bunches with charges of the order of 10 nC.

  17. Physics of Fully Depleted CCDs

    CERN Document Server

    Holland, S E; Kolbe, W F; Lee, J S

    2014-01-01

    In this work we present simple, physics-based models for two effects that have been noted in the fully depleted CCDs that are presently used in the Dark Energy Survey Camera. The first effect is the observation that the point-spread function increases slightly with the signal level. This is explained by considering the effect on charge-carrier diffusion due to the reduction in the magnitude of the channel potential as collected signal charge acts to partially neutralize the fixed charge in the depleted channel. The resulting reduced voltage drop across the carrier drift region decreases the vertical electric field and increases the carrier transit time. The second effect is the observation of low-level, concentric ring patterns seen in uniformly illuminated images. This effect is shown to be most likely due to lateral deflection of charge during the transit of the photogenerated carriers to the potential wells as a result of lateral electric fields. The lateral fields are a result of space charge in the fully...

  18. Effects of Riverbed Conductance on Stream Depletion

    Science.gov (United States)

    Lackey, G.; Neupauer, R. M.; Pitlick, J.

    2012-12-01

    In the western United States and other regions of the world where growing population and changing climates are threatening water supplies, accurate modeling of potential human impacts on water resources is becoming more important. Stream depletion, the reduction of surface water flow due to the extraction of groundwater from a hydraulically connected aquifer, is one of the more direct ways that development can alter water availability, degrade water quality and endanger aquatic habitats. These factors have made the accurate modeling of stream depletion an important step in the process of installing groundwater wells in regions that are susceptible to this phenomenon. Proper estimation of stream depletion requires appropriate parameterization of aquifer and streambed hydraulic properties. Although many studies have conducted numerical investigations to determine stream depletion at specific sites, they typically do not measure streambed hydraulic conductivity (Kr), but rather assume a representative value. In this work, we establish a hypothetical model aquifer that is 2000 m by 1600 m and has a meandering stream running through its center. The Kr of the model stream is varied from 1.0x10-9 m s-1 to 1.0x10-2 m s-1 in order to determine the sensitivity of the stream depletion calculations to this parameter. It was found that when Kr is in the lower part of this range, slight changes in K¬r lead to significant impacts on the calculated stream depletion values. We vary Kr along the stream channel according to naturally occurring patterns and demonstrate that alterations of the parameter over a few orders of magnitude can affect the estimated stream depletion caused by a well at a specified location. The numerical simulations show that the mean value of Kr and its spatial variability along the channel should be realistic to develop an accurate model of stream depletion.

  19. Depleted uranium disposal options evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hertzler, T.J.; Nishimoto, D.D.; Otis, M.D. [Science Applications International Corp., Idaho Falls, ID (United States). Waste Management Technology Div.

    1994-05-01

    The Department of Energy (DOE), Office of Environmental Restoration and Waste Management, has chartered a study to evaluate alternative management strategies for depleted uranium (DU) currently stored throughout the DOE complex. Historically, DU has been maintained as a strategic resource because of uses for DU metal and potential uses for further enrichment or for uranium oxide as breeder reactor blanket fuel. This study has focused on evaluating the disposal options for DU if it were considered a waste. This report is in no way declaring these DU reserves a ``waste,`` but is intended to provide baseline data for comparison with other management options for use of DU. To PICS considered in this report include: Retrievable disposal; permanent disposal; health hazards; radiation toxicity and chemical toxicity.

  20. Rapid and massive carbon injections of the Early Paleogene: The carbonate and planktonic foraminifera records at ODP Site 1215 (Equatorial Pacific Ocean)

    Science.gov (United States)

    Leon Rodriguez, L.; Dickens, G. R.

    2010-12-01

    Models for ocean chemistry indicate that anthropogenic input of CO2 will decrease seawater pH and the concentration of carbonate ion. This should cause dissolution of pelagic carbonate on the seafloor and may reduce biogenic calcification. Stable carbon isotope records spanning the Late Paleocene and Early Eocene show a series of pronounced negative excursions (CIEs) interpreted as massive inputs of carbon. We therefore studied carbonate-rich sediments at Ocean Drilling Program (ODP) Site 1215, which were deposited on the flank of the East Pacific Rise from the Late Paleocene to Early Eocene, to track potential lysocline and ecological changes before, during and after the CIEs. We document four negative CIEs, which correlate to the PETM (Paleocene/Eocene Thermal Maximum, ~55.5 Ma), H1/ETM2 (~53.7 Ma), I1 (~53.2 Ma), and K/X (~52.5 Ma) events. These excursions are characterized by horizons of low carbonate content and an absence of planktonic foraminifers. Shortly after each perturbation, carbonate content and planktonic foraminifer abundance increased dramatically. We interpret these signals as representing time intervals when the lysocline and CCD initially shoaled because of massive carbon addition and subsequently deepened because of accelerated weathering and addition of alkalinity. We observe permanent ecological changes within the photic zone after the PETM. Globanomalinids (intermediate dwellers) more common in the record before the PETM locally disappeared afterwards. In contrast, acarinids and morozovellids (surface dwellers, photosymbont-bearing) were nearly absent before the PETM but become relatively abundant just after. Chiloguembelinids and “Tenuitellids” (intermediate dwellers) are more abundant between the H1/ETM2 and the I1 events, which could be an indication of enhanced carbonate preservation within the recovery phase of the lysocline or conditions that were more favorable for intermediate dwellers. Subbotinids and igorinids are rare in the

  1. An Internal Standard-Assisted Synthesis and Degradation Proteomic Approach Reveals the Potential Linkage between VPS4B Depletion and Activation of Fatty Acid β-Oxidation in Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Zhongping Liao

    2013-01-01

    Full Text Available The endosomal/lysosomal system, in particular the endosomal sorting complexes required for transport (ESCRTs, plays an essential role in regulating the trafficking and destination of endocytosed receptors and their associated signaling molecules. Recently, we have shown that dysfunction and down-regulation of vacuolar protein sorting 4B (VPS4B, an ESCRT-III associated protein, under hypoxic conditions can lead to the abnormal accumulation of epidermal growth factor receptor (EGFR and aberrant EGFR signaling in breast cancer. However, the pathophysiological consequences of VPS4B dysfunction remain largely elusive. In this study, we used an internal standard-assisted synthesis and degradation mass spectrometry (iSDMS method, which permits the direct measurement of protein synthesis, degradation and protein dynamic expression, to address the effects of VPS4B dysfunction in altering EGF-mediated protein expression. Our initial results indicate that VPS4B down-regulation decreases the expression of many proteins involved in glycolytic pathways, while increased the expression of proteins with roles in mitochondrial fatty acid β-oxidation were up-regulated in VPS4B-depleted cells. This observation is also consistent with our previous finding that hypoxia can induce VPS4B down-regulated, suggesting that the adoption of fatty acid β-oxidation could potentially serve as an alternative energy source and survival mechanism for breast cancer cells in response to hypoxia-mediated VPS4B dysfunction.

  2. Quantitative peptidomic analysis by a newly developed one-step direct transfer technology without depletion of major blood proteins: its potential utility for monitoring of pathophysiological status in pregnancy-induced hypertension.

    Science.gov (United States)

    Araki, Yoshihiko; Nonaka, Daisuke; Tajima, Atsushi; Maruyama, Mayuko; Nitto, Takeaki; Ishikawa, Hitoshi; Yoshitake, Hiroshi; Yoshida, Emiko; Kuronaka, Noriko; Asada, Kyoichi; Yanagida, Mitsuaki; Nojima, Michio; Yoshida, Koyo; Takamori, Kenji; Hashiguchi, Teruto; Maruyama, Ikuro; Lee, Lyang-Ja; Tanaka, Kenji

    2011-07-01

    We have recently developed a new target plate (BLOTCHIP®) for MALDI-MS. An advantage of this procedure is that it does not require the lowering of protein concentrations in test samples prior to analysis. Accordingly, this new technology enables the detection of peptides present in blood samples, including those that would otherwise be adsorbed to abundant blood proteins and would thus escape detection. Using this technology, we analyzed the peripheral blood of patients with pregnancy-induced hypertension (PIH; the most common serious complication of pregnancy) to test a potential utility of the technology for monitoring of the pathophysiological status. In the present study, we found 23 characteristic peptides for PIH in the blood serum of pregnant women. Offline LC-MALDI MS/MS identified 7 of the 23 peptides as fragments derived from kininogen-1 (three peptides), fibrinogen-α, complement component C4-A/B, α-2-HS-glycoprotein and inter-α-trypsin inhibitor heavy chain H4. 2-D scatter plots with combinations of the peptides found in the present study can be grouped for pregnant women with/without PIH, which would be satisfactory reflected for their status. Additionally, the levels of most of these peptides found were significantly decreased by albumin/IgG depletion prior to BLOTCHIP® analysis in accordance with conventional proteomics procedures. These results indicated that BLOTCHIP® analysis can be applied for discovery study of PIH biomarker candidates.

  3. The state of knowledge about the potential risks associated to depleted uranium used in weapons; Etat des connaissances sur les risques potentiels associes a l'uranium appauvri utilise dans les armes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-01-01

    This document brigs back the actual knowledge on uranium and its chemical and radiological toxicity. It pays particular attention to discuss the elements allowing to assess the risks linked to the man exposure to depleted uranium. (N.C.)

  4. Depleted zinc: Properties, application, production.

    Science.gov (United States)

    Borisevich, V D; Pavlov, A V; Okhotina, I A

    2009-01-01

    The addition of ZnO, depleted in the Zn-64 isotope, to the water of boiling water nuclear reactors lessens the accumulation of Co-60 on the reactor interior surfaces, reduces radioactive wastes and increases the reactor service-life because of the inhibitory action of zinc on inter-granular stress corrosion cracking. To the same effect depleted zinc in the form of acetate dihydrate is used in pressurized water reactors. Gas centrifuge isotope separation method is applied for production of depleted zinc on the industrial scale. More than 20 years of depleted zinc application history demonstrates its benefits for reduction of NPP personnel radiation exposure and combating construction materials corrosion.

  5. Assessment of Preferred Depleted Uranium Disposal Forms

    Energy Technology Data Exchange (ETDEWEB)

    Croff, A.G.; Hightower, J.R.; Lee, D.W.; Michaels, G.E.; Ranek, N.L.; Trabalka, J.R.

    2000-06-01

    The Department of Energy (DOE) is in the process of converting about 700,000 metric tons (MT) of depleted uranium hexafluoride (DUF6) containing 475,000 MT of depleted uranium (DU) to a stable form more suitable for long-term storage or disposal. Potential conversion forms include the tetrafluoride (DUF4), oxide (DUO2 or DU3O8), or metal. If worthwhile beneficial uses cannot be found for the DU product form, it will be sent to an appropriate site for disposal. The DU products are considered to be low-level waste (LLW) under both DOE orders and Nuclear Regulatory Commission (NRC) regulations. The objective of this study was to assess the acceptability of the potential DU conversion products at potential LLW disposal sites to provide a basis for DOE decisions on the preferred DU product form and a path forward that will ensure reliable and efficient disposal.

  6. Ego depletion impairs implicit learning.

    Science.gov (United States)

    Thompson, Kelsey R; Sanchez, Daniel J; Wesley, Abigail H; Reber, Paul J

    2014-01-01

    Implicit skill learning occurs incidentally and without conscious awareness of what is learned. However, the rate and effectiveness of learning may still be affected by decreased availability of central processing resources. Dual-task experiments have generally found impairments in implicit learning, however, these studies have also shown that certain characteristics of the secondary task (e.g., timing) can complicate the interpretation of these results. To avoid this problem, the current experiments used a novel method to impose resource constraints prior to engaging in skill learning. Ego depletion theory states that humans possess a limited store of cognitive resources that, when depleted, results in deficits in self-regulation and cognitive control. In a first experiment, we used a standard ego depletion manipulation prior to performance of the Serial Interception Sequence Learning (SISL) task. Depleted participants exhibited poorer test performance than did non-depleted controls, indicating that reducing available executive resources may adversely affect implicit sequence learning, expression of sequence knowledge, or both. In a second experiment, depletion was administered either prior to or after training. Participants who reported higher levels of depletion before or after training again showed less sequence-specific knowledge on the post-training assessment. However, the results did not allow for clear separation of ego depletion effects on learning versus subsequent sequence-specific performance. These results indicate that performance on an implicitly learned sequence can be impaired by a reduction in executive resources, in spite of learning taking place outside of awareness and without conscious intent.

  7. Depletable resources and the economy.

    NARCIS (Netherlands)

    Heijman, W.J.M.

    1991-01-01

    The subject of this thesis is the depletion of scarce resources. The main question to be answered is how to avoid future resource crises. After dealing with the complex relation between nature and economics, three important concepts in relation with resource depletion are discussed: steady state, ti

  8. Venting formation fluids from deep-sea boreholes in a ridge flank setting: ODP Sites 1025 and 1026

    Science.gov (United States)

    Wheat, C. Geoffrey; Jannasch, Hans W.; Kastner, Miriam; Plant, Josh N.; Decarlo, Eric H.; Lebon, Geoff

    2004-08-01

    During ODP Leg 168, two of ten boreholes, ODP Holes 1025C and 1026B, were cased through the sediment section, penetrated basaltic crust that is overpressured, and sealed. In 1999 and 2000 the seals were removed, allowing crustal formation fluids to vent and be sampled. The composition of these fluids is compared to those of basal deep-sea pore waters, which have been the basis for estimating geochemical fluxes from low-temperature ridge flank hydrothermal systems. Estimates for the composition of the major ions in formation fluids based on basal pore waters are within 5% of the values measured in borehole fluids. Similar comparisons for minor and trace elements are not as good; some are reactive in the sediment section, resulting in large uncertainties in the pore water extrapolation, while others are influenced by a variety of contaminants, including steel, grease, drilling muds, and basal sediment. Evidence for contamination includes high dissolved and particulate concentrations of several metals (e.g., Fe, Cu, Co, Zn, and Pb) and measurable changes in concentration during the past four years in response to reaction with basal sediment. This new confidence in estimating the primary composition of formation fluids, coupled with advances in thermodynamic and kinetic models, reveals the possibility of anhydrite precipitation in ridge flank hydrothermal systems at temperatures of ˜70°C. Such new insights allow us to address the timing and conditions under which seawater-crustal reactions occur, leading to more accurate models of crustal evolution.

  9. Grand Canonical Ensemble Monte Carlo Simulation of Depletion Interactions in Colloidal Suspensions

    Institute of Scientific and Technical Information of China (English)

    GUO Ji-Yuan; XIAO Chang-Ming

    2008-01-01

    Depletion interactions in colloidal suspensions confined between two parallel plates are investigated by using acceptance ratio method with grand canonical ensemble Monte Carlo simulation.The numerical results show that both the depletion potential and depletion force are affected by the confinement from the two parallel plates.Furthermore,it is found that in the grand canonical ensemble Monte Carlo simulation,the depletion interactions are strongly affected by the generalized chemical potential.

  10. Testing fully depleted CCD

    Science.gov (United States)

    Casas, Ricard; Cardiel-Sas, Laia; Castander, Francisco J.; Jiménez, Jorge; de Vicente, Juan

    2014-08-01

    The focal plane of the PAU camera is composed of eighteen 2K x 4K CCDs. These devices, plus four spares, were provided by the Japanese company Hamamatsu Photonics K.K. with type no. S10892-04(X). These detectors are 200 μm thick fully depleted and back illuminated with an n-type silicon base. They have been built with a specific coating to be sensitive in the range from 300 to 1,100 nm. Their square pixel size is 15 μm. The read-out system consists of a Monsoon controller (NOAO) and the panVIEW software package. The deafualt CCD read-out speed is 133 kpixel/s. This is the value used in the calibration process. Before installing these devices in the camera focal plane, they were characterized using the facilities of the ICE (CSIC- IEEC) and IFAE in the UAB Campus in Bellaterra (Barcelona, Catalonia, Spain). The basic tests performed for all CCDs were to obtain the photon transfer curve (PTC), the charge transfer efficiency (CTE) using X-rays and the EPER method, linearity, read-out noise, dark current, persistence, cosmetics and quantum efficiency. The X-rays images were also used for the analysis of the charge diffusion for different substrate voltages (VSUB). Regarding the cosmetics, and in addition to white and dark pixels, some patterns were also found. The first one, which appears in all devices, is the presence of half circles in the external edges. The origin of this pattern can be related to the assembly process. A second one appears in the dark images, and shows bright arcs connecting corners along the vertical axis of the CCD. This feature appears in all CCDs exactly in the same position so our guess is that the pattern is due to electrical fields. Finally, and just in two devices, there is a spot with wavelength dependence whose origin could be the result of a defectous coating process.

  11. The Decahedrella-event in ODP Hole 909C - Implications for Miocene stratigraphic and paleoclimatic interpretations across the Fram Strait gateway

    Science.gov (United States)

    Schreck, Michael; Nam, Seung-il; Matthiessen, Jens

    2014-05-01

    ODP Hole 909C has been drilled during ODP Leg 151 in 1993 on a small abyssal terrace located immediately to the North of Hovgaard Ridge within the Fram Strait. This major arctic gateway constitutes the only deep-water connection between the Arctic Ocean and the North Atlantic. Moreover, it serves as a pathway for warmer North Atlantic surface waters entering the Central Arctic, and for colder, sea-ice covered waters that are exported to the south. Therefore the Fram Strait is of crucial importance for global ocean circulation and hence climate. Therefore, this deep-water location was designed by ODP to document the timing of the opening of Fram Strait, and to monitor the Cenozoic evolution of water mass exchange as well as the glacial history and climatic variability in a region critical for understanding Miocene climate evolution. The age model of ODP Hole 909C is primarily based on the interpretation of the magnetic polarity record obtained during the ODP Leg 151 cruise, and provides significant temporal constraints only for the uppermost 40 mbsf, whereas limited recovery and the uncertain occurrence of hiatuses resulted in decreasing reliability of the magnetostratigraphic interpretations downcore and widely divergent hypothesis below 200 mbsf. Two possible correlations of the magnetic signal to the global polarity timescale have been proposed, both neither unique nor definitive, and in the absence of any additional independent age control it is difficult to distinguish between the two models, which in turn seriously hampers reliable paleoenvironmental reconstructions in the Neogene of the gateway region. A detailed palynological study on a paleoenvironmental transect across Fram Strait comprising IODP Site M2 (Central Arctic Ocean), ODP Site 909 (Fram Strait), and ODP Site 907 (Iceland Sea) revealed the presence of a significant acme of the endemic high-latitude acritarch Decahedrella martinheadii at all three sites. Comparable high abundances of this cold

  12. Multiscale modelling approach combining a kinetic model of glutathione metabolism with PBPK models of paracetamol and the potential glutathione-depletion biomarkers ophthalmic acid and 5-oxoproline in humans and rats

    NARCIS (Netherlands)

    Geenen, S.; Yates, J.W.T.; Kenna, J.G.; Bois, F.Y.; Wilson, I.D.; Westerhoff, H.V.

    2013-01-01

    A key role of the antioxidant glutathione is detoxification of chemically reactive electrophilic drug metabolites within the liver. Therefore glutathione depletion can have severe toxic consequences. Ophthalmic acid and 5-oxoproline are metabolites involved in glutathione metabolism, which can be me

  13. Astronomical calibration of upper Campanian–Maastrichtian carbon isotope events and calcareous plankton biostratigraphy in the Indian Ocean (ODP Hole 762C)

    DEFF Research Database (Denmark)

    Thibault, Nicolas Rudolph; Husson, Dorothée; Harlou, Rikke

    2012-01-01

    An integrated framework of magnetostratigraphy, calcareous microfossil bio-events, cyclostratigraphy and d13C stratigraphy is established for the upper Campanian–Maastrichtian of ODP Hole 762C (Exmouth Plateau, Northwestern Australian margin). Bulk-carbonate d13C events and nannofossil bio-events...

  14. Discharge of hydrothermal fluids through sediment at the Escanaba Trough, Gorda Ridge (ODP Leg 169): assessing the effects on the rock magnetic signal

    NARCIS (Netherlands)

    Urbat, Michael; Dekkers, M.J.; Krumsiek, Klaus

    2000-01-01

    An integrated rock-magnetic and multivariate statistical analysis of a suite of sediment samples recovered from ODP Sites 1037 and 1038 (Leg 169, Escanaba Trough, Gorda Ridge spreading center, NE Pacific Ocean) has been carried out to assess the use of the sediment magnetic signal as a tracer of pos

  15. Discharge of hydrothermal fluids through sediment at the Escanaba Trough, Gorda Ridge (ODP Leg 169): assessing the effects on the rock magnetic signal

    NARCIS (Netherlands)

    Urbat, Michael; Dekkers, M.J.; Krumsiek, Klaus

    2002-01-01

    An integrated rock-magnetic and multivariate statistical analysis of a suite of sediment samples recovered from ODP Sites 1037 and 1038 (Leg 169, Escanaba Trough, Gorda Ridge spreading center, NE Pacific Ocean) has been carried out to assess the use of the sediment magnetic signal as a tracer of pos

  16. 黄铁矿产酸成分与中和酸成分的消耗及其有效成分的确定%DEPLETION OF ACID POTENTIAL (AP) AND NEUTRALIZATION POTENTIAL (NP) FROM PYRITE AND THE DETERMINATION OF AP AND NP AVAILABILITY

    Institute of Scientific and Technical Information of China (English)

    李锦文; 李晓; 吴惠明; 陈永亨; Basra Sohan

    2011-01-01

    动态浸滤法研究黄铁矿氧化产酸过程中产酸成分(AP)和中和酸成分(NP)的消耗,讨论了有效NP、AP的确定.50周实验结果表明:(1)中和酸成分NP和产酸成分AP消耗速率呈非线性变化.酸性排放(ARD)前,即pH=4前,AP、NP平均消耗速率VAP与VNPp基本相同;ARD开始释放后,VAP>2VNP;(2)排放液pH<3后,Fe3+参与并加速氧化反应,AP消耗的平均速率及固溶物溶出速率提高4倍以上;(3)抑制ARD释放的有效NP<50%,控制排放液中性的有效NP<30%;引起ARD释放的有效AP>75%,且ARD将持续释放30年以上.%The depletion of Neutralization Potential (NP) and Acid Potential (AP) and the determination of available AP and available NP in pyrite acidification process were studied by using kinetic flood leaching in humidity cell. 50 cycles kinetic test for the studied sample shows that: ( 1 ) The rate of NP and AP depletion changed nonlinearly. The average rate of NP depletion (VNP) is almost same as the average rate of AP deletion (VAP) before onset of acid rock drainage ( drainage pH = 4). VAP is more than 2 VNP after onset of acid rock drainage (ARD); (2) Fe3 + speeds the sulphide oxidation and VAP together with the rate of mineral dissolution increased by over 4 times after drainage pH < 3; (3) The NP availability controlling ARD is less than 50% and NP availability keeping drainage neutral is less than 30%. The AP availability causing ARD is more than 75% and ARD will last more than 30 years.

  17. "When the going gets tough, who keeps going?" Depletion sensitivity moderates the ego-depletion effect.

    Science.gov (United States)

    Salmon, Stefanie J; Adriaanse, Marieke A; De Vet, Emely; Fennis, Bob M; De Ridder, Denise T D

    2014-01-01

    Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In three studies, we assessed individual differences in depletion sensitivity, and demonstrate that depletion sensitivity moderates ego-depletion effects. The Depletion Sensitivity Scale (DSS) was employed to assess depletion sensitivity. Study 1 employs the DSS to demonstrate that individual differences in sensitivity to ego-depletion exist. Study 2 shows moderate correlations of depletion sensitivity with related self-control concepts, indicating that these scales measure conceptually distinct constructs. Study 3 demonstrates that depletion sensitivity moderates the ego-depletion effect. Specifically, participants who are sensitive to depletion performed worse on a second self-control task, indicating a stronger ego-depletion effect, compared to participants less sensitive to depletion.

  18. Replacements For Ozone-Depleting Foaming Agents

    Science.gov (United States)

    Blevins, Elana; Sharpe, Jon B.

    1995-01-01

    Fluorinated ethers used in place of chlorofluorocarbons and hydrochlorofluorocarbons. Replacement necessary because CFC's and HCFC's found to contribute to depletion of ozone from upper atmosphere, and manufacture and use of them by law phased out in near future. Two fluorinated ethers do not have ozone-depletion potential and used in existing foam-producing equipment, designed to handle liquid blowing agents soluble in chemical ingredients that mixed to make foam. Any polyurethane-based foams and several cellular plastics blown with these fluorinated ethers used in processes as diverse as small batch pours, large sprays, or double-band lamination to make insulation for private homes, commercial buildings, shipping containers, and storage tanks. Fluorinated ethers proved useful as replacements for CFC refrigerants and solvents.

  19. The Olorgesailie Drilling Project (ODP): a high-resolution drill core record from a hominin site in the East African Rift Valley

    Science.gov (United States)

    Dommain, R.; Potts, R.; Behrensmeyer, A. K.; Deino, A. L.

    2014-12-01

    The East African rift valley contains an outstanding record of hominin fossils that document human evolution over the Plio-Pleistocene when the global and regional climate and the rift valley itself changed markedly. The sediments of fossil localities typically provide, however, only short time windows into past climatic and environmental conditions. Continuous, long-term terrestrial records are now becoming available through core drilling to help elucidate the paleoenvironmental context of human evolution. Here we present a 500,000 year long high-resolution drill core record obtained from a key fossil and archeological site - the Olorgesailie Basin in the southern Kenya Rift Valley, well known for its sequence of archeological and faunal sites for the past 1.2 million years. In 2012 two drill cores (54 and 166 m long) were collected in the Koora Plain just south of Mt. Olorgesailie as part of the Olorgesailie Drilling Project (ODP) to establish a detailed climate and ecological record associated with the last evidence of Homo erectus in Africa, the oldest transition of Acheulean to Middle Stone Age technology, and large mammal species turnover, all of which are documented in the Olorgesailie excavations. The cores were sampled at the National Lacustrine Core Facility. More than 140 samples of tephra and trachytic basement lavas have led to high-precision 40Ar/39Ar dating. The cores are being analyzed for a suite of paleoclimatic and paleoecological proxies such as diatoms, pollen, fungal spores, phytoliths, ostracodes, carbonate isotopes, leaf wax biomarkers, charcoal, and clay mineralogy. Sedimentological analyses, including lithological descriptions, microscopic smear slide analysis (242 samples), and grain-size analysis, reveal a highly variable sedimentary sequence of deep lake phases with laminated sediments, diatomites, shallow lake and near shore phases, fluvial deposits, paleosols, interspersed carbonate layers, and abundant volcanic ash deposits. Magnetic

  20. Variations of opal accumulation rates and paleoproductivity over the past 12 Ma at ODP Site 1143,southern South China Sea

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The biogenic silica analysis was performed on 463 samples from ODP 184 Site 1143, the southern South China Sea. The results show that the opal content and MAR evidently increased between 12.3 and 5.7 Ma, which was contemporary with the high carbonate and total MARs, reflecting the high biogenic productivity in the late Miocene.This demonstrates the occurrence of the late Miocene "Biogenie Bloom Event" in the southern South China Sea, corresponding to the late Miocene-early Pliocene "Biogenic Bloom Event" in the Indian-Pacific Ocean. The increases of opal content and MAR after the middle Pleistocene (about 0.7 Ma)is inferred to result from the enhanced upwelling and nutrient supply, which was induced by the intensified monsoon circulation after the "Mid-Pleistocene Revolution".

  1. Deep-sea palaeoceanography of the Maldives Islands (ODP Hole 716A), equatorial Indian Ocean during MIS 12–6

    Indian Academy of Sciences (India)

    S Sarkar; A K Gupta

    2009-11-01

    Deep-sea benthic foraminifera, planktic foraminifer Globigerina bulloides and pteropods have been quantitatively analysed in 451 samples from Ocean Drilling Program (ODP) Hole 716A, to understand both surface and deep-sea palaeoceanographic changes in the equatorial Indian Ocean basin during the late Quaternary (∼444–151 Kyrs). Benthic foraminifera were analysed from > 125 m size fraction whereas Globigerina bulloides and pteropods were analysed from > 150 m size fraction. Factor analysis of most dominant benthic foraminiferal species over the studied time span made it possible to identify three biofacies characterizing distinct deep-sea environmental settings at Hole 716A. The environmental interpretation of each species is based on the ecology of recent deep-sea benthic foraminifera. The faunal record indicates fluctuating deep-sea conditions including changes in surface productivity, organic food supply and deep-sea oxygenation linked to changing wind intensities. These changes are pronounced on glacial-interglacial time scales driven by summer monsoon winds.

  2. Depleting depletion: Polymer swelling in poor solvent mixtures

    Science.gov (United States)

    Mukherji, Debashish; Marques, Carlos; Stuehn, Torsten; Kremer, Kurt

    A polymer collapses in a solvent when the solvent particles dislike monomers more than the repulsion between monomers. This leads to an effective attraction between monomers, also referred to as depletion induced attraction. This attraction is the key factor behind standard polymer collapse in poor solvents. Strikingly, even if a polymer exhibits poor solvent condition in two different solvents, it can also swell in mixtures of these two poor solvents. This collapse-swelling-collapse scenario is displayed by poly(methyl methacrylate) (PMMA) in aqueous alcohol. Using molecular dynamics simulations of a thermodynamically consistent generic model and theoretical arguments, we unveil the microscopic origin of this phenomenon. Our analysis suggests that a subtle interplay of the bulk solution properties and the local depletion forces reduces depletion effects, thus dictating polymer swelling in poor solvent mixtures.

  3. Revisiting the Ceara Rise, equatorial Atlantic Ocean: isotope stratigraphy of ODP Leg 154 from 0 to 5 Ma

    Directory of Open Access Journals (Sweden)

    R. H. Wilkens

    2017-07-01

    Full Text Available Isotope stratigraphy has become the method of choice for investigating both past ocean temperatures and global ice volume. Lisiecki and Raymo (2005 published a stacked record of 57 globally distributed benthic δ18O records versus age (LR04 stack. In this study LR04 is compared to high-resolution records collected at all of the sites drilled during ODP Leg 154 on the Ceara Rise, in the western equatorial Atlantic Ocean. Newly developed software is used to check data splices of the Ceara Rise sites and better align out-of-splice data with in-splice data. Core images recovered from core table photos are depth and age scaled and greatly assist in the data analysis. The entire splices of ODP sites 925, 926, 927, 928 and 929 were reviewed. Most changes were minor although several were large enough to affect age models based on orbital tuning. A Ceara Rise composite record of benthic δ18O is out of sync with LR04 between 1.80 and 1.90 Ma, where LR04 exhibits two maxima but Ceara Rise data contain only one. The interval between 4.0 and 4.5 Ma in the Ceara Rise compilation is decidedly different from LR04, reflecting both the low amplitude of the signal over this interval and the limited amount of data available for the LR04 stack. A regional difference in benthic δ18O of 0.2 ‰ relative to LR04 was found. Independent tuning of Site 926 images and physical property data to the Laskar et al. (2004 orbital solution and integration of available benthic stable isotope data from the Ceara Rise provides a new regional reference section for the equatorial Atlantic covering the last 5 million years.

  4. Pliocene-Pleistocene changes in Arctic sea-ice cover: New biomarker records from Fram Strait/Yermak Plateau (ODP Sites 911 and 912)

    Science.gov (United States)

    Stein, Ruediger; Fahl, Kirsten

    2013-04-01

    Recently, a novel and promising biomarker proxy for reconstruction of Arctic sea-ice conditions was developed and is based on the determination of a highly branched isoprenoid with 25 carbons (IP25; Belt et al., 2007). Following this pioneer IP25 study by Belt and colleagues, several IP25 studies of marine surface sediments and sediment cores as well as sediment trap samples from northpolar areas were carried out successfully and allowed detailed reconstruction of modern and late Quaternary sea ice variability in these regions (e.g., Massé et al., 2008; Müller et al., 2009, 2011; Vare et al., 2009; Belt et al., 2010; Fahl and Stein, 2012; for review see Stein et al., 2012). Here, we present new (low-resolution) biomarker records from Ocean Drilling Program (ODP) Sites 911 and 912, representing the Pliocene-Pleistocene time interval (including the interval of major intensification of Northern Hemisphere Glaciation near 2.7 Ma). These data indicate that sea ice of variable extent was present in the Fram Strait/southern Yermak Plateau area during most of the time period under investigation. In general, an increase in sea-ice cover seems to correlate with phases of extended late Pliocene-Pleistocene continental ice-sheets. At ODP Site 912, a significant increase in sea-ice extension occurred near 1.2 Ma (Stein and Fahl, 2012). Furthermore, our data support the idea that a combination of IP25 and open water, phytoplankton biomarker data ("PIP25 index"; Müller et al., 2011) may give more reliable and quantitative estimates of past sea-ice cover (at least for the study area). This study reveals that the novel IP25/PIP25 biomarker approach has potential for semi-quantitative paleo-sea ice studies covering the entire Quaternary and motivate to carry out further detailed high-resolution research on ODP/IODP material using this proxy. References Belt, S.T., Massé, G., Rowland, S.J., Poulin, M., Michel, C., LeBlanc, B., 2007. A novel chemical fossil of palaeo sea ice: IP25

  5. Rotational Mixing and Lithium Depletion

    CERN Document Server

    Pinsonneault, M H

    2010-01-01

    I review basic observational features in Population I stars which strongly implicate rotation as a mixing agent; these include dispersion at fixed temperature in coeval populations and main sequence lithium depletion for a range of masses at a rate which decays with time. New developments related to the possible suppression of mixing at late ages, close binary mergers and their lithium signature, and an alternate origin for dispersion in young cool stars tied to radius anomalies observed in active young stars are discussed. I highlight uncertainties in models of Population II lithium depletion and dispersion related to the treatment of angular momentum loss. Finally, the origins of rotation are tied to conditions in the pre-main sequence, and there is thus some evidence that enviroment and planet formation could impact stellar rotational properties. This may be related to recent observational evidence for cluster to cluster variations in lithium depletion and a connection between the presence of planets and s...

  6. Charge depletion in organic heterojunction

    Science.gov (United States)

    Ng, T. W.; Lo, M. F.; Lee, S. T.; Lee, C. S.

    2012-03-01

    Until now two types of organic-organic heterojunction (OHJ) have been observed in P-N junctions formed between undoped-organic semiconductors. Charge-transfers across OHJs are either negligible or showing electron transfer from P-type to N-type materials, leading to charges accumulation near the interface. Here, we observed that junction of 4,4',4''-tris(2-methylphenyl-phenylamino)triphenylamine (m-MTDATA)/bathocuproine (BCP) show the third-behavior. Electrons in BCP (N-type) transfer to m-MTDATA (P-type), leading to depletion of mobile majority carriers near the junction. While "depletion junctions" are typical in inorganic semiconductors, there are no reports in undoped-OHJ. Formation mechanism of depletion OHJs and fundamental differences between inorganic and organic HJs are discussed.

  7. Associative Interactions in Crowded Solutions of Biopolymers Counteract Depletion Effects.

    Science.gov (United States)

    Groen, Joost; Foschepoth, David; te Brinke, Esra; Boersma, Arnold J; Imamura, Hiromi; Rivas, Germán; Heus, Hans A; Huck, Wilhelm T S

    2015-10-14

    The cytosol of Escherichia coli is an extremely crowded environment, containing high concentrations of biopolymers which occupy 20-30% of the available volume. Such conditions are expected to yield depletion forces, which strongly promote macromolecular complexation. However, crowded macromolecule solutions, like the cytosol, are very prone to nonspecific associative interactions that can potentially counteract depletion. It remains unclear how the cytosol balances these opposing interactions. We used a FRET-based probe to systematically study depletion in vitro in different crowded environments, including a cytosolic mimic, E. coli lysate. We also studied bundle formation of FtsZ protofilaments under identical crowded conditions as a probe for depletion interactions at much larger overlap volumes of the probe molecule. The FRET probe showed a more compact conformation in synthetic crowding agents, suggesting strong depletion interactions. However, depletion was completely negated in cell lysate and other protein crowding agents, where the FRET probe even occupied slightly more volume. In contrast, bundle formation of FtsZ protofilaments proceeded as readily in E. coli lysate and other protein solutions as in synthetic crowding agents. Our experimental results and model suggest that, in crowded biopolymer solutions, associative interactions counterbalance depletion forces for small macromolecules. Furthermore, the net effects of macromolecular crowding will be dependent on both the size of the macromolecule and its associative interactions with the crowded background.

  8. CONTRIBUIÇÃO AOS ESTUDOS DA PRECIPITAÇÃO NO ESTADO DO PARANÁ: A OSCILAÇÃO DECADAL DO PACÍFICO - ODP

    Directory of Open Access Journals (Sweden)

    Lindberg Nascimento Júnior

    2016-04-01

    Full Text Available A Oscilação Decadal do Pacífico – ODP tem sido discutida como a teleconexão de baixa frequência mais recorrente do Oceano Pacífico. A oscilação é caracterizada por meio das temperaturas da superfície do mar e pela temporalidade de atuação na escala de 20 a 30 anos. No Brasil, associações entre ODP nas dinâmicas climáticas regionais e locais são verificadas principalmente na variabilidade pluviométrica. No Paraná, estudos que associaram a oscilação à dinâmica pluviométrica e/ou climática foram obtidos de forma indireta. Neste contexto, o objetivo do trabalho é apresentar as características por meio de associações e correlações espaciais e temporais obtidas por testes estatísticos para a precipitação no estado. O intuito é contribuir aos estudos sobre a gênese das chuvas na região, considerando a variabilidade pluviométrica em escala decadal, e destacando a ODP como um fenômeno que auxilia na produção das chuvas no estado. Foram utilizadas séries históricas de 1976 a 2011: a com dados mensais de chuva e número de dias com chuva, agrupados em escalas trimestrais, sazonais e anuais; e b com índices anuais padronizados da ODP. A caracterização foi processada pela associação em função da similaridade temporal da ODP e das chuvas no Paraná e as correlações foram obtidas pelo coeficiente de correlação linear de Pearson. Em geral, a participação da ODP se mostrou com sinal fraco para chuvas, numa relação de 11% a 20%, considerando o coeficiente de determinação (r². Para os números de dias com chuva a correlação foi de 17 a 46%, sugerindo uma relação com sinal moderado-fraco. Os resultados corroboram para o melhor entendimento das gêneses das chuvas em regiões de clima tropical, especialmente para o Paraná, e aponta abordagens interpretativas dos impactos regionais e locais de teleconexões climáticas de baixa frequência.

  9. Impact of mineral resource depletion

    CSIR Research Space (South Africa)

    Brent, AC

    2006-09-01

    Full Text Available In a letter to the editor, the authors comment on BA Steen's article on "Abiotic Resource Depletion: different perceptions of the problem with mineral deposits" published in the special issue of the International Journal of Life Cycle Assessment...

  10. Global depletion of groundwater resources

    NARCIS (Netherlands)

    Wada, Y.; Beek, L.P.H. van; van Kempen, C.M.; Reckman, J.W.T.M.; Vasak, S.; Bierkens, M.F.P.

    2010-01-01

    In regions with frequent water stress and large aquifer systems groundwater is often used as an additional water source. If groundwater abstraction exceeds the natural groundwater recharge for extensive areas and long times, overexploitation or persistent groundwater depletion occurs. Here we provid

  11. Cord blood glutathione depletion in preterm infants: correlation with maternal cysteine depletion.

    Directory of Open Access Journals (Sweden)

    Alice Küster

    Full Text Available BACKGROUND: Depletion of blood glutathione (GSH, a key antioxidant, is known to occur in preterm infants. OBJECTIVE: Our aim was to determine: 1 whether GSH depletion is present at the time of birth; and 2 whether it is associated with insufficient availability of cysteine (cys, the limiting GSH precursor, or a decreased capacity to synthesize GSH. METHODOLOGY: Sixteen mothers delivering very low birth weight infants (VLBW, and 16 mothers delivering healthy, full term neonates were enrolled. Immediately after birth, erythrocytes from umbilical vein, umbilical artery, and maternal blood were obtained to assess GSH [GSH] and cysteine [cys] concentrations, and the GSH synthesis rate was determined from the incorporation of labeled cysteine into GSH in isolated erythrocytes ex vivo, measured using gas chromatography mass spectrometry. PRINCIPAL FINDINGS: Compared with mothers delivering at full term, mothers delivering prematurely had markedly lower erythrocyte [GSH] and [cys] and these were significantly depressed in VLBW infants, compared with term neonates. A strong correlation was found between maternal and fetal GSH and cysteine levels. The capacity to synthesize GSH was as high in VLBW as in term infants. CONCLUSION: The current data demonstrate that: 1 GSH depletion is present at the time of birth in VLBW infants; 2 As VLBW neonates possess a fully active capacity to synthesize glutathione, the depletion may arise from inadequate cysteine availability, potentially due to maternal depletion. Further studies would be needed to determine whether maternal-fetal cysteine transfer is decreased in preterm infants, and, if so, whether cysteine supplementation of mothers at risk of delivering prematurely would strengthen antioxidant defense in preterm neonates.

  12. Depletion Interactions in a Cylindric Pipeline with a Small Shape Change

    Institute of Scientific and Technical Information of China (English)

    LI Chun-Shu; GAO Hai-Xia; XIAO Chang-Ming

    2007-01-01

    Stressed by external forces, it is possible for a cylindric pipeline to change into an elliptic pipeline. To expose the effect of small shape change of the pipeline on the depletion interactions, both the depletion potentials and depletion forces in the hard sphere systems confined by a cylindric pipeline or by an elliptic pipeline are studied by Monte Carlo simulations. The numerical results show that the depletion interactions are strongly affected by the small change of the shape of the pipeline in a way. Furthermore, it is also found that the depletion interactions will be strengthened if the short axis of the elliptic pipeline is decreased.

  13. Therapeutic ultrasound as a potential male contraceptive: power, frequency and temperature required to deplete rat testes of meiotic cells and epididymides of sperm determined using a commercially available system

    Directory of Open Access Journals (Sweden)

    Tsuruta James K

    2012-01-01

    Full Text Available Abstract Background Studies published in the 1970s by Mostafa S. Fahim and colleagues showed that a short treatment with ultrasound caused the depletion of germ cells and infertility. The goal of the current study was to determine if a commercially available therapeutic ultrasound generator and transducer could be used as the basis for a male contraceptive. Methods Sprague-Dawley rats were anesthetized and their testes were treated with 1 MHz or 3 MHz ultrasound while varying power, duration and temperature of treatment. Results We found that 3 MHz ultrasound delivered with 2.2 Watt per square cm power for fifteen minutes was necessary to deplete spermatocytes and spermatids from the testis and that this treatment significantly reduced epididymal sperm reserves. 3 MHz ultrasound treatment reduced total epididymal sperm count 10-fold lower than the wet-heat control and decreased motile sperm counts 1,000-fold lower than wet-heat alone. The current treatment regimen provided nominally more energy to the treatment chamber than Fahim's originally reported conditions of 1 MHz ultrasound delivered at 1 Watt per square cm for ten minutes. However, the true spatial average intensity, effective radiating area and power output of the transducers used by Fahim were not reported, making a direct comparison impossible. We found that germ cell depletion was most uniform and effective when we rotated the therapeutic transducer to mitigate non-uniformity of the beam field. The lowest sperm count was achieved when the coupling medium (3% saline was held at 37 degrees C and two consecutive 15-minute treatments of 3 MHz ultrasound at 2.2 Watt per square cm were separated by 2 days. Conclusions The non-invasive nature of ultrasound and its efficacy in reducing sperm count make therapeutic ultrasound a promising candidate for a male contraceptive. However, further studies must be conducted to confirm its efficacy in providing a contraceptive effect, to test the

  14. Modeling CO2 Sequestration in Saline Aquifer and Depleted Oil Reservoir To Evaluate Regional CO2 Sequestration Potential of Ozark Plateau Aquifer System, South-Central Kansas

    Energy Technology Data Exchange (ETDEWEB)

    Watney, W. Lynn [University Of Kansas Center For Research, Inc. Lawrence, KS (United States)

    2014-09-30

    1. Drilled, cored, and logged three wells to the basement and collecting more than 2,700 ft of conventional core; obtained 20 mi2 of multicomponent 3D seismic imaging and merged and reprocessed more than 125 mi2 of existing 3D seismic data for use in modeling CO2- EOR oil recovery and CO2 storage in five oil fields in southern Kansas. 2. Determined the technical feasibility of injecting and sequestering CO2 in a set of four depleted oil reservoirs in the Cutter, Pleasant Prairie South, Eubank, and Shuck fields in southwest Kansas; of concurrently recovering oil from those fields; and of quantifying the volumes of CO2 sequestered and oil recovered during the process. 3. Formed a consortium of six oil operating companies, five of which own and operate the four fields. The consortium became part of the Southwest Kansas CO2-EOR Initiative for the purpose of sharing data, knowledge, and interest in understanding the potential for CO2-EOR in Kansas. 4. Built a regional well database covering 30,000 mi2 and containing stratigraphic tops from ~90,000 wells; correlated 30 major stratigraphic horizons; digitized key wells, including wireline logs and sample logs; and analyzed more than 3,000 drill stem tests to establish that fluid levels in deep aquifers below the Permian evaporites are not connected to the surface and therefore pressures are not hydrostatic. Connectivity with the surface aquifers is lacking because shale aquitards and impermeable evaporite layers consist of both halite and anhydrite. 5. Developed extensive web applications and an interactive mapping system that do the following: a. Facilitate access to a wide array of data obtained in the study, including core descriptions and analyses, sample logs, digital (LAS) well logs, seismic data, gravity and magnetics maps, structural and stratigraphic maps, inferred fault traces, earthquakes, Class I and II disposal wells, and

  15. Modeling CO2 Sequestration in Saline Aquifer and Depleted Oil Reservoir To Evaluate Regional CO2 Sequestration Potential of Ozark Plateau Aquifer System, South-Central Kansas

    Energy Technology Data Exchange (ETDEWEB)

    Watney, W. Lynn [University Of Kansas Center For Research, Inc. Lawrence, KS (United States)

    2014-09-30

    1. Drilled, cored, and logged three wells to the basement and collecting more than 2,700 ft of conventional core; obtained 20 mi2 of multicomponent 3D seismic imaging and merged and reprocessed more than 125 mi2 of existing 3D seismic data for use in modeling CO2- EOR oil recovery and CO2 storage in five oil fields in southern Kansas. 2. Determined the technical feasibility of injecting and sequestering CO2 in a set of four depleted oil reservoirs in the Cutter, Pleasant Prairie South, Eubank, and Shuck fields in southwest Kansas; of concurrently recovering oil from those fields; and of quantifying the volumes of CO2 sequestered and oil recovered during the process. 3. Formed a consortium of six oil operating companies, five of which own and operate the four fields. The consortium became part of the Southwest Kansas CO2-EOR Initiative for the purpose of sharing data, knowledge, and interest in understanding the potential for CO2-EOR in Kansas. 4. Built a regional well database covering 30,000 mi2 and containing stratigraphic tops from ~90,000 wells; correlated 30 major stratigraphic horizons; digitized key wells, including wireline logs and sample logs; and analyzed more than 3,000 drill stem tests to establish that fluid levels in deep aquifers below the Permian evaporites are not connected to the surface and therefore pressures are not hydrostatic. Connectivity with the surface aquifers is lacking because shale aquitards and impermeable evaporite layers consist of both halite and anhydrite. 5. Developed extensive web applications and an interactive mapping system that do the following: a. Facilitate access to a wide array of data obtained in the study, including core descriptions and analyses, sample logs, digital (LAS) well logs, seismic data, gravity and magnetics maps, structural and stratigraphic maps, inferred fault traces, earthquakes, Class I and II disposal wells, and

  16. Wall depletion length of a channel-confined polymer

    Science.gov (United States)

    Cheong, Guo Kang; Li, Xiaolan; Dorfman, Kevin D.

    2017-02-01

    Numerous experiments have taken advantage of DNA as a model system to test theories for a channel-confined polymer. A tacit assumption in analyzing these data is the existence of a well-defined depletion length characterizing DNA-wall interactions such that the experimental system (a polyelectrolyte in a channel with charged walls) can be mapped to the theoretical model (a neutral polymer with hard walls). We test this assumption using pruned-enriched Rosenbluth method (PERM) simulations of a DNA-like semiflexible polymer confined in a tube. The polymer-wall interactions are modeled by augmenting a hard wall interaction with an exponentially decaying, repulsive soft potential. The free energy, mean span, and variance in the mean span obtained in the presence of a soft wall potential are compared to equivalent simulations in the absence of the soft wall potential to determine the depletion length. We find that the mean span and variance about the mean span have the same depletion length for all soft potentials we tested. In contrast, the depletion length for the confinement free energy approaches that for the mean span only when depletion length no longer depends on channel size. The results have implications for the interpretation of DNA confinement experiments under low ionic strengths.

  17. Sulphide mineral evolution and metal mobility during alteration of the oceanic crust: Insights from ODP Hole 1256D

    Science.gov (United States)

    Patten, C. G. C.; Pitcairn, I. K.; Teagle, D. A. H.; Harris, M.

    2016-11-01

    Fluxes of metals during the hydrothermal alteration of the oceanic crust have far reaching effects including buffering of the compositions of the ocean and lithosphere, supporting microbial life and the formation of sulphide ore deposits. The mechanisms responsible for metal mobilisation during the evolution of the oceanic crust are complex and are neither fully constrained nor quantified. Investigations into the mineral reactions that release metals, such as sulphide leaching, would generate better understanding of the controls on metal mobility in the oceanic crust. We investigate the sulphide and oxide mineral paragenesis and the extent to which these minerals control the metal budget in samples from Ocean Drilling Program (ODP) Hole 1256D. The ODP Hole 1256D drill core provides a unique sample suite representative of a complete section of a fast-spreading oceanic crust from the volcanic section down to the plutonic complex. The sulphide population at Hole 1256D is divided into five groups based on mineralogical assemblage, lithological location and texture: the magmatic, metasomatised, high temperature hydrothermal, low temperature and patchy sulphides. The initiation of hydrothermal alteration by downward flow of moderate temperature (250-350 °C) hydrothermal fluids under oxidising conditions leads to metasomatism of the magmatic sulphides in the sheeted dyke and plutonic complexes. Subsequent increase in the degree of hydrothermal alteration at temperatures >350 °C under reducing conditions then leads to the leaching of the metasomatised sulphides by rising hydrothermal fluids. Mass balance calculations show that the mobility of Cu, Se and Au occurs through sulphide leaching during high temperature hydrothermal alteration and that the mobility of Zn, As, Sb and Pb is controlled by silicate rather than sulphide alteration. Sulphide leaching is not complete at Hole 1256D and more advanced alteration would mobilise greater masses of metals. Alteration of oxide

  18. The Blake Nose Cretaceous-Paleogene (Florida Atlantic margin, ODP Leg 171B): an exemplar record of the Maastrichtian-Danian transition

    Science.gov (United States)

    Bellier, J.-P.; Marca, S.; Norris, R.D.; Kroon, D.; Klaus, A.; Alexander, I.T.; Bardot, L.P.; Barker, C.E.; Blome, C.D.; Clarke, L.J.; Erbacher, J.; Faul, K.L.; Holmes, M.A.; Huber, B.T.; Katz, M.E.; MacLeod, K.G.; Martinez-Ruiz, F. C.; Mita, I.; Nakai, M.; Ogg, J.G.; Pak, D.K.; Pletsch, T.K.; ,; Shackleton, N.J.; Smit, J.; Ussler, W.; Watkins, D.K.; Widmark, J.; Wilson, P.A.

    1997-01-01

    During ODP Leg 171B, devoted to the analysis of the Blake Plateau margin in front of Florida, 16 holes have been drilled in 5 distinct sites. The sites have documented a sedimentary succession ranging in age from Aptian to Eocene. Emphasis has been put on critical periods, comprising the Paleocene-Eocene transition, the Cretaceous-Tertiary boundary which has been cored in excellent conditions, the middle Maastrichtian extinctions and the Albian anoxic episodes.

  19. Sediment transport time measured with U-Series isotopes: Resultsfrom ODP North Atlantic Drill Site 984

    Energy Technology Data Exchange (ETDEWEB)

    DePaolo, Donald J.; Maher, Kate; Christensen, John N.; McManus,Jerry

    2006-06-05

    High precision uranium isotope measurements of marineclastic sediments are used to measure the transport and storage time ofsediment from source to site of deposition. The approach is demonstratedon fine-grained, late Pleistocene deep-sea sediments from Ocean DrillingProgram Site 984A on the Bjorn Drift in the North Atlantic. The sedimentsare siliciclastic with up to 30 percent carbonate, and dated by sigma 18Oof benthic foraminifera. Nd and Sr isotopes indicate that provenance hasoscillated between a proximal source during the last three interglacialperiods volcanic rocks from Iceland and a distal continental sourceduring glacial periods. An unexpected finding is that the 234U/238Uratios of the silicate portion of the sediment, isolated by leaching withhydrochloric acid, are significantly less than the secular equilibriumvalue and show large and systematic variations that are correlated withglacial cycles and sediment provenance. The 234U depletions are inferredto be due to alpha-recoil loss of234Th, and are used to calculate"comminution ages" of the sediment -- the time elapsed between thegeneration of the small (<_ 50 mu-m) sediment grains in the sourceareas by comminution of bedrock, and the time of deposition on theseafloor. Transport times, the difference between comminution ages anddepositional ages, vary from less than 10 ky to about 300 to 400 ky forthe Site 984A sediments. Long transport times may reflect prior storagein soils, on continental shelves, or elsewhere on the seafloor. Transporttime may also be a measure of bottom current strength. During the mostrecent interglacial periods the detritus from distal continental sourcesis diluted with sediment from Iceland that is rapidly transported to thesite of deposition. The comminution age approach could be used to dateQuaternary non-marine sediments, soils, and atmospheric dust, and may beenhanced by concomitant measurement of 226Ra/230Th, 230Th/234U, andcosmogenic nuclides.

  20. Ozone Depletion from Nearby Supernovae

    CERN Document Server

    Gehrels, N; Jackman, C H; Cannizzo, J K; Mattson, B J; Chen, W; Gehrels, Neil; Laird, Claude M.; Jackman, Charles H.; Cannizzo, John K.; Mattson, Barbara J.; Chen, Wan

    2003-01-01

    Estimates made in the 1970's indicated that a supernova occurring within tens of parsecs of Earth could have significant effects on the ozone layer. Since that time, improved tools for detailed modeling of atmospheric chemistry have been developed to calculate ozone depletion, and advances have been made in theoretical modeling of supernovae and of the resultant gamma-ray spectra. In addition, one now has better knowledge of the occurrence rate of supernovae in the galaxy, and of the spatial distribution of progenitors to core-collapse supernovae. We report here the results of two-dimensional atmospheric model calculations that take as input the spectral energy distribution of a supernova, adopting various distances from Earth and various latitude impact angles. In separate simulations we calculate the ozone depletion due to both gamma-rays and cosmic rays. We find that for the combined ozone depletion roughly to double the ``biologically active'' UV flux received at the surface of the Earth, the supernova mu...

  1. Ozone Depletion from Nearby Supernovae

    Science.gov (United States)

    Gehrels, Neil; Laird, Claude M.; Jackman, Charles H.; Cannizzo, John K.; Mattson, Barbara J.; Chen, Wan; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    Estimates made in the 1970's indicated that a supernova occurring within tens of parsecs of Earth could have significant effects on the ozone layer. Since that time improved tools for detailed modeling of atmospheric chemistry have been developed to calculate ozone depletion, and advances have been made also in theoretical modeling of supernovae and of the resultant gamma ray spectra. In addition, one now has better knowledge of the occurrence rate of supernovae in the galaxy, and of the spatial distribution of progenitors to core-collapse supernovae. We report here the results of two-dimensional atmospheric model calculations that take as input the spectral energy distribution of a supernova, adopting various distances from Earth and various latitude impact angles. In separate simulations we calculate the ozone depletion due to both gamma rays and cosmic rays. We find that for the combined ozone depletion from these effects roughly to double the 'biologically active' UV flux received at the surface of the Earth, the supernova must occur at approximately or less than 8 parsecs.

  2. Magnetic rock properties of the gabbros from the ODP Drill Hole 1105 A of the Atlantis Bank, Southwest Indian Ridge

    Indian Academy of Sciences (India)

    D Gopala Rao; K S Krishna

    2002-12-01

    Laboratory studies of 30 samples from 158m long drill core of the Hole 1105A (ODP Leg 179) of the Atlantis Bank, Southwest Indian Ridge have revealed magnetic properties of the gabbros, olivine gabbros, oxide gabbros and olivine oxide gabbros down the core. Comparison of modal proportions of the oxides, grain sizes and magnetization parameters of the rocks has confirmed that most coarse-grained oxide mineral bearing rocks record low Koenigsberger ratio (2 to 5) and median destructive fields (5 to 7 mT). Average natural remanent magnetization () and stable remanent magnetization () of the core samples are 5.8A/m and 1.9 A/m, respectively. Their mean stable magnetic inclination is 66° ± 4°, about 14° steeper than the expected dipole inclination of the area similar to the one reported at Hole 735 B. The excess inclination perhaps marks a tectonic block rotation of the reversely magnetized rocks of the bank. We interpret that gabbros and serpentinites devoid of basaltic carapace significantly contribute to seafloor spreading anomalies of the bank.

  3. Responses of foraminiferal isotopic variations at ODP Site 1143 in the southern South China Sea to orbital forcing

    Institute of Scientific and Technical Information of China (English)

    TIAN; Jun; WANG; Pinxian; CHENG; Xinrong

    2004-01-01

    The foraminiferal δ18O and δ13C records for the past 5 Ma at ODP Site 1143 reveal the linear responses of the Plio-Pleistocene climatic changes in the southern South China Sea to orbital forcing at the obliquity and precession bands. The phase of the δ18O variations with the orbital forcing is opposite to that of the δ13C, which may be caused by the frequent El Nino events from the equatorial Pacific. The amplification of the Northern Hemisphere Ice Sheet at ~3.3 Ma probably affected the development of the 100-ka climatic cycles. Its further spreading may spur the 100-ka climatic cycle to become the dominant cycle in the late Pleistocene. The "MidPleistocene Transition" event has localized influence on the isotopic variations in the southern South China Sea. The foraminiferal δ13C records for the past 5 Ma at Site 1143 are highly coherent with the orbital forcing at the long eccentricity band, and lead the δ18O records at the shorter eccentricity band, highlighting the importance of the carbon cycle in the global climate change.

  4. Glass chemistry in volcaniclastic sediments of ODP Leg 107, Site 650, sedimentary sequence: provenance and chronological implications

    Science.gov (United States)

    Calanchi, Natale; Gasparotto, Giorgio; Romagnoli, Claudia

    1994-03-01

    A detailed chemical investigation of volcanic glass fragments from volcaniclastic strata (6 tephras, 1 volcanic debris flow, 12 volcanic turbidites) of ODP Leg 107, Site 650, sedimentary sequence, leads to a varied pattern in terms of both provenance and age constraints. The six analyzed tephra strata indicate a provenance from at least three different volcanic provinces: Aeolian, Campanian, and Sicilian Channel (Pantelleria Island). The older tephra strata (021, 018, 012) have a large amount of "orogenic" rhyodacite/rhyolite deposits that may be attributed to the Aeolian province, although no subaerial coeval volcanic activity of similar composition has so far been documented in the Aeolian Arc. Tephra 007 is related to the Pantelleria Island activity and, particularly, to an ignimbrite episode dated circa 130 ka. Tephra strata 005 and 003, have a clear Campanian provenance, and are correlated with analogous tephra layers, observed in the Tyrrhenian and Ionian seas, dated circa 107 and 60 ka respectively. In the oldest portion of the sequence (from 1.3 to 0.13 Ma), the volcaniclastic sediments were only derived from the Aeolian domain whereas in the latest 130 ka, the Campanian influx becomes much more predominant. Therefore, a general K-enrichment trend is observed in the temporal sequence of all the analyzed samples (almost 700 point analyses) which may be related both to a variation in the source area and to the specific Pleistocene magmatic evolution of the peri-Tyrrhenian volcanic provinces.

  5. Lateral continuity of basement seismic reflections in 15 Ma ultrafast-spreading crust at ODP Site 1256

    Science.gov (United States)

    Nag, Sreeja; Swift, Stephen A.

    2011-09-01

    The Ocean Drilling Program (ODP) initiated drilling at Site 1256D in the Guatemala Basin, about 1,000 km off the East Pacific Rise to penetrate plutonic rocks, anticipated to be relatively shallow in this region, formed at an ultra-fast spreading rate. IODP Expedition E312 successfully drilled into gabbros at ~1,150 m in basement. Multi-channel seismic traces show weak laterally coherent sub-basement reflections at borehole depths. Synthetic reflectivity seismograms were computed using a Ricker wavelet and impedance profiles from borehole sonic logs. These seismograms show significant sub-basement amplitude peaks. A zero-offset vertical seismic profile, shot on E312, was processed to investigate the authenticity of these reflections and their relationship to borehole geology. A dual scheme of the median filtering and F-K dip filtering was used. Tests with synthetic seismograms indicate the approach is effective at reasonable SNR levels. Downgoing energy is clearly identified but negligible upgoing energy is visible over random noise. These results indicate that lava flows and igneous contacts in upper ocean crust have significant topography on lateral scales less than the Fresnel Zone (~300 m) due to igneous and tectonic processes.

  6. Magnesium isotope composition of the altered upper oceanic crust at ODP Holes 504B and 896A, Costa Rica Rift

    Science.gov (United States)

    Beaumais, Aurélien; Teagle, Damon A. H.; James, Rachael H.; Harris, Michelle; Pearce, Christopher R.; Milton, James A.; Cooper, Matthew J.; Alt, Jeffrey C.

    2017-04-01

    Chemical reactions between the oceanic crust and seawater play a major role in regulating the composition of the oceans that, in turn, influence important geochemical cycles (e.g., C, S, Mg). It is well established that alteration of the oceanic crust is the principal sink of Mg in seawater, but the effect of this process on the Mg isotope composition of the oceans remains unclear. Here we present the first measurements of Mg isotopes in altered oceanic crust from ODP Holes 504B and 896A. These holes are located in 5.9 Ma crust located 200 km south of the intermediate spreading rate Costa Rica Rift. Hole 504B penetrates: (i) A volcanic section, consisting of primitive to moderately altered mid-ocean ridge basalt (MORB) that was open to seawater alteration under oxic-suboxic conditions at temperatures rocks altered under low temperature (rock scale. [1] Teng et al., (2010) GCA 74, 4150-4166. [2] Huang et al., (2015) Lithos 231, 53-61.

  7. Response of eastern Indian Ocean (ODP Site 762B benthic foraminiferal assemblages to the closure of the Indonesian seaway

    Directory of Open Access Journals (Sweden)

    Ajai Kumar Rai

    2012-06-01

    Full Text Available Pliocene-Pleistocene deep sea benthic foraminifera from ODP Site 762B in the eastern Indian Ocean were examined to understand the tectonically/climatically induced palaeoceanographic changes. In addition to already published data on this site by Rai & Singh (2001, some more faunal parameters were considered in the present work. Characteristic benthic foraminiferal assemblages as well as more diverse fauna during the early Pliocene (before 3.5 Ma reflected relatively oligotrophic and warm bottom water conditions. At the beginning of the late Pliocene (i.e. ~ 3 ± 0.5 Ma relative abundances of Uvigerina proboscidea, infaunal taxa and high productivity taxa increased, whereas faunal diversity showed a distinct decline, suggesting the development of pronounced upwelling resulting in higher surface water productivity. The strongly reduced inflow of warm and oligotrophic water masses as the South Equatorial Current (SEC from the South Pacific to the eastern Indian Ocean due to the effective closure of the Indonesian seaway increased the surface water productivity. The closing of the Indonesian seaway during the late Pliocene was also responsible for the cessation of the warm, southward-flowing Leeuwin Current (LC and the greater influence of the cold, deep and northward-flowing Western Australian Current (WAC in the eastern Indian Ocean.

  8. The Eocene-Oligocene transition at ODP Site 1263, Atlantic Ocean: decreases in nannoplankton size and abundance and correlation with benthic foraminiferal assemblages

    Science.gov (United States)

    Bordiga, M.; Henderiks, J.; Tori, F.; Monechi, S.; Fenero, R.; Thomas, E.

    2015-05-01

    The biotic response of calcareous nannoplankton to environmental and climatic changes during the Eocene-Oligocene transition (~34.8-32.7 Ma) was investigated at high resolution at Ocean Drilling Program (ODP) Site 1263 (Walvis Ridge, South East Atlantic Ocean), and compared with a lower resolution benthic foraminiferal record. During this time interval, the global climate which had been warm during the Eocene, under high levels of atmospheric CO2 (pCO2), transitioned into the cooler climate of the Oligocene, with overall lower pCO2. At Site 1263, the absolute nannofossil abundance (coccoliths per gram of sediment; N g-1) and the mean coccolith size decreased distinctly across the E-O boundary (EOB; 33.89 Ma), mainly due to a sharp decline in abundance of large-sized Reticulofenestra and Dictyococcites, within ~53 kyr. Since carbonate dissolution did not vary much across the EOB, the decrease in abundance and size of nannofossils may highlight an overall decrease in their export production, which could have led to an increased ratio of organic to inorganic carbon (calcite) burial, as well as variations in the food availability for benthic foraminifers. The benthic foraminiferal assemblage data show the global decline in abundance of rectilinear species with complex apertures in the latest Eocene (~34.5 Ma), potentially reflecting changes in the food source, thus phytoplankton, followed by transient increased abundance of species indicative of seasonal delivery of food to the sea floor (Epistominella spp.; ~34.04-33.54 Ma), with a short peak in overall food delivery at the EOB (buliminid taxa; ~33.9 Ma). After Oi-1 (starting at ~33.4 Ma), a high abundance of Nuttallides umbonifera indicates the presence of more corrosive bottom waters, possibly combined with less food arriving at the sea floor. The most important signals in the planktonic and benthic communities, i.e. the marked decrease of large reticulofenestrids, extinctions of planktonic foraminifer species and

  9. The Case of Ozone Depletion

    Science.gov (United States)

    Lambright, W. Henry

    2005-01-01

    While the National Aeronautics and Space Administration (NASA) is widely perceived as a space agency, since its inception NASA has had a mission dedicated to the home planet. Initially, this mission involved using space to better observe and predict weather and to enable worldwide communication. Meteorological and communication satellites showed the value of space for earthly endeavors in the 1960s. In 1972, NASA launched Landsat, and the era of earth-resource monitoring began. At the same time, in the late 1960s and early 1970s, the environmental movement swept throughout the United States and most industrialized countries. The first Earth Day event took place in 1970, and the government generally began to pay much more attention to issues of environmental quality. Mitigating pollution became an overriding objective for many agencies. NASA's existing mission to observe planet Earth was augmented in these years and directed more toward environmental quality. In the 1980s, NASA sought to plan and establish a new environmental effort that eventuated in the 1990s with the Earth Observing System (EOS). The Agency was able to make its initial mark via atmospheric monitoring, specifically ozone depletion. An important policy stimulus in many respects, ozone depletion spawned the Montreal Protocol of 1987 (the most significant international environmental treaty then in existence). It also was an issue critical to NASA's history that served as a bridge linking NASA's weather and land-resource satellites to NASA s concern for the global changes affecting the home planet. Significantly, as a global environmental problem, ozone depletion underscored the importance of NASA's ability to observe Earth from space. Moreover, the NASA management team's ability to apply large-scale research efforts and mobilize the talents of other agencies and the private sector illuminated its role as a lead agency capable of crossing organizational boundaries as well as the science-policy divide.

  10. Action orientation overcomes the ego depletion effect.

    Science.gov (United States)

    Dang, Junhua; Xiao, Shanshan; Shi, Yucai; Mao, Lihua

    2015-04-01

    It has been consistently demonstrated that initial exertion of self-control had negative influence on people's performance on subsequent self-control tasks. This phenomenon is referred to as the ego depletion effect. Based on action control theory, the current research investigated whether the ego depletion effect could be moderated by individuals' action versus state orientation. Our results showed that only state-oriented individuals exhibited ego depletion. For individuals with action orientation, however, their performance was not influenced by initial exertion of self-control. The beneficial effect of action orientation against ego depletion in our experiment results from its facilitation for adapting to the depleting task.

  11. "When the going gets tough, who keeps going?" Depletion sensitivity moderates the ego-depletion effect

    NARCIS (Netherlands)

    Salmon, Stefanie J.; Adriaanse, Marieke A.; De Vet, Emely; Fennis, Bob M.; De Ridder, Denise T D

    2014-01-01

    Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In thre

  12. "When the going gets tough, who keeps going?" : Depletion sensitivity moderates the ego-depletion effect

    NARCIS (Netherlands)

    Salmon, Stefanie J.; Adriaanse, Marieke A.; De Vet, Emely; Fennis, Bob M.; De Ridder, Denise T. D.

    2014-01-01

    Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In thre

  13. "When the going gets tough, who keeps going?" : Depletion sensitivity moderates the ego-depletion effect

    NARCIS (Netherlands)

    Salmon, Stefanie J.; Adriaanse, Marieke A.; De Vet, Emely; Fennis, Bob M.; De Ridder, Denise T. D.

    2014-01-01

    Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In thre

  14. The 1988 Antarctic ozone depletion - Comparison with previous year depletions

    Science.gov (United States)

    Schoeberl, Mark R.; Stolarski, Richard S.; Krueger, Arlin J.

    1989-01-01

    The 1988 spring Antarctic ozone depletion was observed by TOMS to be substantially smaller than in recent years. The minimum polar total ozone values declined only 15 percent during September 1988, compared to nearly 50 percent during September 1987. At southern midlatitudes, exceptionally high total ozone values were recorded beginning in July 1988. The total integrated southern hemispheric ozone increased rapidly during the Austral spring, approaching 1980 levels during October. The high midlatitude total ozone values were associated with a substantial increase in eddy activity as indicated by the standard deviation in total ozone in the zonal band 30-60 deg S. Mechanisms through which the increased midlatitude eddy activity could disrupt the formation of the Antarctic ozone hole are briefly discussed.

  15. Novel degenerate PCR method for whole genome amplification applied to Peru Margin (ODP Leg 201 subsurface samples

    Directory of Open Access Journals (Sweden)

    Amanda eMartino

    2012-01-01

    Full Text Available A degenerate PCR-based method of whole-genome amplification, designed to work fluidly with 454 sequencing technology, was developed and tested for use on deep marine subsurface DNA samples. The method, which we have called Random Amplification Metagenomic PCR (RAMP, involves the use of specific primers from Roche 454 amplicon sequencing, modified by the addition of a degenerate region at the 3’ end. It utilizes a PCR reaction, which resulted in no amplification from blanks, even after 50 cycles of PCR. After efforts to optimize experimental conditions, the method was tested with DNA extracted from cultured E. coli cells, and genome coverage was estimated after sequencing on three different occasions. Coverage did not vary greatly with the different experimental conditions tested, and was around 62% with a sequencing effort equivalent to a theoretical genome coverage of 14.10X. The GC content of the sequenced amplification product was within 2% of the predicted values for this strain of E. coli. The method was also applied to DNA extracted from marine subsurface samples from ODP Leg 201 site 1229 (Peru Margin, and results of a taxonomic analysis revealed microbial communities dominated by Proteobacteria, Chloroflexi, Firmicutes, Euryarchaeota, and Crenarchaeota, among others. These results were similar to those obtained previously for those samples; however, variations in the proportions of taxa show that community analysis can be sensitive to both the amplification technique used and the method of assigning sequences to taxonomic groups. Overall, we find that RAMP represents a valid methodology for amplifying metagenomes from low biomass samples.

  16. Ozone depletion following future volcanic eruptions

    Science.gov (United States)

    Eric Klobas, J.; Wilmouth, David M.; Weisenstein, Debra K.; Anderson, James G.; Salawitch, Ross J.

    2017-07-01

    While explosive volcanic eruptions cause ozone loss in the current atmosphere due to an enhancement in the availability of reactive chlorine following the stratospheric injection of sulfur, future eruptions are expected to increase total column ozone as halogen loading approaches preindustrial levels. The timing of this shift in the impact of major volcanic eruptions on the thickness of the ozone layer is poorly known. Modeling four possible climate futures, we show that scenarios with the smallest increase in greenhouse gas concentrations lead to the greatest risk to ozone from heterogeneous chemical processing following future eruptions. We also show that the presence in the stratosphere of bromine from natural, very short-lived biogenic compounds is critically important for determining whether future eruptions will lead to ozone depletion. If volcanic eruptions inject hydrogen halides into the stratosphere, an effect not considered in current ozone assessments, potentially profound reductions in column ozone would result.

  17. Resource depletion does not influence prospective memory in college students

    Science.gov (United States)

    Talley Shelton, Jill; Cahill, Michael J.; Mullet, Hillary G.; Scullin, Michael K.; Einstein, Gilles O.; McDaniel, Mark A.

    2013-01-01

    This paper reports an experiment designed to investigate the potential influence of prior acts of self-control on subsequent prospective memory performance. College undergraduates (n = 146) performed either a cognitively depleting initial task (e.g., mostly incongruent Stroop task) or a less resource-consuming version of that task (e.g., all congruent Stroop task). Subsequently, participants completed a prospective memory task that required attentionally demanding monitoring processes. The results demonstrated that prior acts of self-control do not impair the ability to execute a future intention in college-aged adults. We conceptually replicated these results in three additional depletion and prospective memory experiments. This research extends a growing number of studies demonstrating the boundary conditions of the resource depletion effect in cognitive tasks. PMID:24021851

  18. Attempted Depletion of Passenger Leukocytes by Irradiation in Pigs

    Directory of Open Access Journals (Sweden)

    Hao-Chih Tai

    2011-01-01

    Full Text Available Allograft/xenograft rejection is associated with “passenger leukocyte” migration from the organ into recipient lymph nodes. In Study 1, we attempted to deplete leukocytes from potential kidney “donor” pigs, using two regimens of total body irradiation. A dose of 700 cGy was administered, followed by either 800 cGy (“low-dose” or 1,300 cGy (“high dose” with the kidneys shielded. Neither regimen was entirely successful in depleting all leukocytes, although remaining T and 8 cell numbers were negligible. Study 2 was aimed at providing an indication of whether near-complete depletion of leukocytes had any major impact on kidney allograft survival. In non-immunosuppressed recipient pigs, survival of a kidney from a donor that received high-dose irradiation was compared with that of a kidney taken from a non-irradiated donor. Kidney graft survival was 9 and 7 days, respectively, suggesting that depletion had little impact on graft survival. The lack of effect may have been related to (i inadequate depletion of passenger leukocytes, thus not preventing a direct T cell response, (ii the presence of dead or dying leukocytes (antigens, thus not preventing an indirect T cell response, or (iii constitutive expression of MHC class II and B7 molecules on the porcine vascular endothelium, activating recipient T cells.

  19. Bond rupture between colloidal particles with a depletion interaction

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, Kathryn A.; Furst, Eric M., E-mail: furst@udel.edu [Department of Chemical and Biomolecular Engineering and Center for Molecular and Engineering Thermodynamics, University of Delaware, Newark, Delaware 19716 (United States)

    2016-05-15

    The force required to break the bonds of a depletion gel is measured by dynamically loading pairs of colloidal particles suspended in a solution of a nonadsorbing polymer. Sterically stabilized poly(methyl methacrylate) colloids that are 2.7 μm diameter are brought into contact in a solvent mixture of cyclohexane-cyclohexyl bromide and polystyrene polymer depletant. The particle pairs are subject to a tensile load at a constant loading rate over many approach-retraction cycles. The stochastic nature of the thermal rupture events results in a distribution of bond rupture forces with an average magnitude and variance that increases with increasing depletant concentration. The measured force distribution is described by the flux of particle pairs sampling the energy barrier of the bond interaction potential based on the Asakura–Oosawa depletion model. A transition state model demonstrates the significance of lubrication hydrodynamic interactions and the effect of the applied loading rate on the rupture force of bonds in a depletion gel.

  20. Coarse-grained molecular dynamics simulations of depletion-induced interactions for soft matter systems.

    Science.gov (United States)

    Shendruk, Tyler N; Bertrand, Martin; Harden, James L; Slater, Gary W; de Haan, Hendrick W

    2014-12-28

    Given the ubiquity of depletion effects in biological and other soft matter systems, it is desirable to have coarse-grained Molecular Dynamics (MD) simulation approaches appropriate for the study of complex systems. This paper examines the use of two common truncated Lennard-Jones (Weeks-Chandler-Andersen (WCA)) potentials to describe a pair of colloidal particles in a thermal bath of depletants. The shifted-WCA model is the steeper of the two repulsive potentials considered, while the combinatorial-WCA model is the softer. It is found that the depletion-induced well depth for the combinatorial-WCA model is significantly deeper than the shifted-WCA model because the resulting overlap of the colloids yields extra accessible volume for depletants. For both shifted- and combinatorial-WCA simulations, the second virial coefficients and pair potentials between colloids are demonstrated to be well approximated by the Morphometric Thermodynamics (MT) model. This agreement suggests that the presence of depletants can be accurately modelled in MD simulations by implicitly including them through simple, analytical MT forms for depletion-induced interactions. Although both WCA potentials are found to be effective generic coarse-grained simulation approaches for studying depletion effects in complicated soft matter systems, combinatorial-WCA is the more efficient approach as depletion effects are enhanced at lower depletant densities. The findings indicate that for soft matter systems that are better modelled by potentials with some compressibility, predictions from hard-sphere systems could greatly underestimate the magnitude of depletion effects at a given depletant density.

  1. Coarse-grained molecular dynamics simulations of depletion-induced interactions for soft matter systems

    Energy Technology Data Exchange (ETDEWEB)

    Shendruk, Tyler N., E-mail: tyler.shendruk@physics.ox.ac.uk [The Rudolf Peierls Centre for Theoretical Physics, Department of Physics, Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom); Bertrand, Martin; Harden, James L.; Slater, Gary W. [Department of Physics, University of Ottawa, 150 Louis-Pasteur, Ottawa, Ontario K1N 6N5 (Canada); Haan, Hendrick W. de [Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe St. North, Oshawa, Ontario L1H 7K4 (Canada)

    2014-12-28

    Given the ubiquity of depletion effects in biological and other soft matter systems, it is desirable to have coarse-grained Molecular Dynamics (MD) simulation approaches appropriate for the study of complex systems. This paper examines the use of two common truncated Lennard-Jones (Weeks-Chandler-Andersen (WCA)) potentials to describe a pair of colloidal particles in a thermal bath of depletants. The shifted-WCA model is the steeper of the two repulsive potentials considered, while the combinatorial-WCA model is the softer. It is found that the depletion-induced well depth for the combinatorial-WCA model is significantly deeper than the shifted-WCA model because the resulting overlap of the colloids yields extra accessible volume for depletants. For both shifted- and combinatorial-WCA simulations, the second virial coefficients and pair potentials between colloids are demonstrated to be well approximated by the Morphometric Thermodynamics (MT) model. This agreement suggests that the presence of depletants can be accurately modelled in MD simulations by implicitly including them through simple, analytical MT forms for depletion-induced interactions. Although both WCA potentials are found to be effective generic coarse-grained simulation approaches for studying depletion effects in complicated soft matter systems, combinatorial-WCA is the more efficient approach as depletion effects are enhanced at lower depletant densities. The findings indicate that for soft matter systems that are better modelled by potentials with some compressibility, predictions from hard-sphere systems could greatly underestimate the magnitude of depletion effects at a given depletant density.

  2. Coarse-grained molecular dynamics simulations of depletion-induced interactions for soft matter systems

    Science.gov (United States)

    Shendruk, Tyler N.; Bertrand, Martin; Harden, James L.; Slater, Gary W.; de Haan, Hendrick W.

    2014-12-01

    Given the ubiquity of depletion effects in biological and other soft matter systems, it is desirable to have coarse-grained Molecular Dynamics (MD) simulation approaches appropriate for the study of complex systems. This paper examines the use of two common truncated Lennard-Jones (Weeks-Chandler-Andersen (WCA)) potentials to describe a pair of colloidal particles in a thermal bath of depletants. The shifted-WCA model is the steeper of the two repulsive potentials considered, while the combinatorial-WCA model is the softer. It is found that the depletion-induced well depth for the combinatorial-WCA model is significantly deeper than the shifted-WCA model because the resulting overlap of the colloids yields extra accessible volume for depletants. For both shifted- and combinatorial-WCA simulations, the second virial coefficients and pair potentials between colloids are demonstrated to be well approximated by the Morphometric Thermodynamics (MT) model. This agreement suggests that the presence of depletants can be accurately modelled in MD simulations by implicitly including them through simple, analytical MT forms for depletion-induced interactions. Although both WCA potentials are found to be effective generic coarse-grained simulation approaches for studying depletion effects in complicated soft matter systems, combinatorial-WCA is the more efficient approach as depletion effects are enhanced at lower depletant densities. The findings indicate that for soft matter systems that are better modelled by potentials with some compressibility, predictions from hard-sphere systems could greatly underestimate the magnitude of depletion effects at a given depletant density.

  3. A Monte Carlo Study of Influences on Depletion Force from Another Large Sphere in Colloidal Suspensions

    Institute of Scientific and Technical Information of China (English)

    XIAO Chang-Ming; GUO Ji-Yuan; HU Ping

    2006-01-01

    @@ According to the acceptance ratio method, the influences on the depletion interactions between a large sphere and a plate from another closely placed large sphere are studied by Monte Carlo simulation. The numerical results show that both the depletion potential and depletion force are affected by the presence of the closely placed large sphere; the closer the large sphere are placed to them, the larger the influence will be. Furthermore, the influences on the depletion interactions from another large sphere are more sensitive to the angle than to the distance.

  4. An Early Cenozoic Ichthyolith Record from Demerara Rise (ODP Site 1258: Equatorial Atlantic Ocean)

    Science.gov (United States)

    Bryant, R. M.; Sibert, E. C.; Norris, R. D.

    2014-12-01

    ichthyoliths and identifying morphotypes will improve our understanding of the pelagic community in deep time and specifically its response to global climate change, which will in turn inform us about fish evolution through time and their potential response to anthropogenic climate forcings.

  5. Ego depletion increases risk-taking.

    Science.gov (United States)

    Fischer, Peter; Kastenmüller, Andreas; Asal, Kathrin

    2012-01-01

    We investigated how the availability of self-control resources affects risk-taking inclinations and behaviors. We proposed that risk-taking often occurs from suboptimal decision processes and heuristic information processing (e.g., when a smoker suppresses or neglects information about the health risks of smoking). Research revealed that depleted self-regulation resources are associated with reduced intellectual performance and reduced abilities to regulate spontaneous and automatic responses (e.g., control aggressive responses in the face of frustration). The present studies transferred these ideas to the area of risk-taking. We propose that risk-taking is increased when individuals find themselves in a state of reduced cognitive self-control resources (ego-depletion). Four studies supported these ideas. In Study 1, ego-depleted participants reported higher levels of sensation seeking than non-depleted participants. In Study 2, ego-depleted participants showed higher levels of risk-tolerance in critical road traffic situations than non-depleted participants. In Study 3, we ruled out two alternative explanations for these results: neither cognitive load nor feelings of anger mediated the effect of ego-depletion on risk-taking. Finally, Study 4 clarified the underlying psychological process: ego-depleted participants feel more cognitively exhausted than non-depleted participants and thus are more willing to take risks. Discussion focuses on the theoretical and practical implications of these findings.

  6. Revisiting ODP Site 690 to Assess the Responses of Marine Carbonate Chemistry to the Paleocene-Eocene Thermal Maximum

    Science.gov (United States)

    Kelly, D. C.; Zachos, J. C.; Bralower, T. J.; Schellenberg, S. A.

    2004-12-01

    The close of the Paleocene epoch (ca. 55 Ma) is punctuated by a transient (warmth and carbonate dissolution. Here we revisit what is arguably the most complete deep-sea record of the PETM recovered from ODP Site 690 to explore the dynamic coupling between atmospheric CO2 levels, marine carbonate chemistry, continental weathering and global climate. The abrupt onset of the CIE is accompanied by a sharp decline in wt.% carbonate, yet wt.% coarse-fraction (>63 microns, foraminiferal shells) values remain fairly constant. These sedimentological shifts collectively point toward the selective removal of fine-fraction (warmth. We believe this selective pattern of "dissolution" actually reflects, in part, reduced calcification among some calcareous nannofossil taxa. An important corollary of this interpretation is that rising pCO2 levels attained a critical threshold that inhibited nannoplankton calcification. Decreased surface-ocean carbonate production triggered a shoaling of the local lysocline and concomitantly enhanced the ocean's carbon-storage capacity providing an important sink for atmospheric CO2. The character of carbonate sedimentation is reversed during the later, recovery stages of the CIE. It is within this stratigraphically expanded portion of the CIE that wt.% carbonate values and the relative proportion of wt.% fine-fraction increase markedly. This secondary shift coincides with a 5 degrees C cooling of intermediate waters and a sharp influx of kaolinite. Concurrent cooling of sea-surface temperatures is also suggested by the disappearance of warm-water microplankton. We believe these changes to be interrelated. The kaolinite spike likely reflects intensified silicate weathering on Antarctica as well as increased continental runoff. Thus, enhanced silicate weathering reactions (CaSiCO3 + CO2 -> SiO2 + CaCO3) may have served as an added sink for atmospheric CO2 and a source of oceanic Ca2+ and HCO3- that drove an alkalinity overshoot thereby fostering

  7. Investigation of intranodal depletion effects

    Energy Technology Data Exchange (ETDEWEB)

    Forslund, P. E-mail: petri.forslund@se.abb.com; Mueller, E.; Lindahl, S

    2001-02-01

    The modeling of depletion induced intranodal effects on important neutron physical parameters in nodal diffusion theory is addressed. Consideration is given to two situations where these aspects are of particular interest, namely, in mixed oxide cores where strong interaction between uranium and plutonium mixed oxide assemblies occur, and in boiling water reactor cores where significant control rod history effects are encountered. A model based on a low order polynomial representation of intranodal cross-section spatial behaviour is considered. Two approaches for determining the constraints for the polynomial fitting procedure are applied. The first one is a conventional method employing intranodal exposure values, whereas the second model combines intranodal exposure and isotopic inventory information. Numerical studies are performed in order to evaluate the relative merits of the different models. It is demonstrated that pin power predictions are significantly influenced by intranodal effects. It is also found that the combined use of intranodal isotopic inventory and exposure distributions for estimating intranodal cross-section behaviour significantly improves the accuracy in pin powers over the more traditional approach of utilizing exposure distributions only.

  8. Depleted argon from underground sources

    Energy Technology Data Exchange (ETDEWEB)

    Back, H.O.; /Princeton U.; Alton, A.; /Augustana U. Coll.; Calaprice, F.; Galbiati, C.; Goretti, A.; /Princeton U.; Kendziora, C.; /Fermilab; Loer, B.; /Princeton U.; Montanari, D.; /Fermilab; Mosteiro, P.; /Princeton U.; Pordes, S.; /Fermilab

    2011-09-01

    Argon is a powerful scintillator and an excellent medium for detection of ionization. Its high discrimination power against minimum ionization tracks, in favor of selection of nuclear recoils, makes it an attractive medium for direct detection of WIMP dark matter. However, cosmogenic {sup 39}Ar contamination in atmospheric argon limits the size of liquid argon dark matter detectors due to pile-up. The cosmic ray shielding by the earth means that Argon from deep underground is depleted in {sup 39}Ar. In Cortez Colorado a CO{sub 2} well has been discovered to contain approximately 500ppm of argon as a contamination in the CO{sub 2}. In order to produce argon for dark matter detectors we first concentrate the argon locally to 3-5% in an Ar, N{sub 2}, and He mixture, from the CO{sub 2} through chromatographic gas separation. The N{sub 2} and He will be removed by continuous cryogenic distillation in the Cryogenic Distillation Column recently built at Fermilab. In this talk we will discuss the entire extraction and purification process; with emphasis on the recent commissioning and initial performance of the cryogenic distillation column purification.

  9. Depletion sensitivity predicts unhealthy snack purchases

    NARCIS (Netherlands)

    Salmon, Stefanie J.; Adriaanse, Marieke A.; Fennis, Bob M.; Vet, De Emely; Ridder, De Denise T.D.

    2016-01-01

    The aim of the present research is to examine the relation between depletion sensitivity - a novel construct referring to the speed or ease by which one's self-control resources are drained - and snack purchase behavior. In addition, interactions between depletion sensitivity and the goal to lose

  10. Depletion sensitivity predicts unhealthy snack purchases

    NARCIS (Netherlands)

    Salmon, Stefanie J.; Adriaanse, Marieke A.|info:eu-repo/dai/nl/304823023; Fennis, Bob M.; De Vet, Emely; De Ridder, Denise T D

    2016-01-01

    The aim of the present research is to examine the relation between depletion sensitivity - a novel construct referring to the speed or ease by which one's self-control resources are drained - and snack purchase behavior. In addition, interactions between depletion sensitivity and the goal to lose

  11. The Chemistry and Toxicology of Depleted Uranium

    Directory of Open Access Journals (Sweden)

    Sidney A. Katz

    2014-03-01

    Full Text Available Natural uranium is comprised of three radioactive isotopes: 238U, 235U, and 234U. Depleted uranium (DU is a byproduct of the processes for the enrichment of the naturally occurring 235U isotope. The world wide stock pile contains some 1½ million tons of depleted uranium. Some of it has been used to dilute weapons grade uranium (~90% 235U down to reactor grade uranium (~5% 235U, and some of it has been used for heavy tank armor and for the fabrication of armor-piercing bullets and missiles. Such weapons were used by the military in the Persian Gulf, the Balkans and elsewhere. The testing of depleted uranium weapons and their use in combat has resulted in environmental contamination and human exposure. Although the chemical and the toxicological behaviors of depleted uranium are essentially the same as those of natural uranium, the respective chemical forms and isotopic compositions in which they usually occur are different. The chemical and radiological toxicity of depleted uranium can injure biological systems. Normal functioning of the kidney, liver, lung, and heart can be adversely affected by depleted uranium intoxication. The focus of this review is on the chemical and toxicological properties of depleted and natural uranium and some of the possible consequences from long term, low dose exposure to depleted uranium in the environment.

  12. High homocysteine induces betaine depletion.

    Science.gov (United States)

    Imbard, Apolline; Benoist, Jean-François; Esse, Ruben; Gupta, Sapna; Lebon, Sophie; de Vriese, An S; de Baulny, Helene Ogier; Kruger, Warren; Schiff, Manuel; Blom, Henk J

    2015-04-28

    Betaine is the substrate of the liver- and kidney-specific betaine-homocysteine (Hcy) methyltransferase (BHMT), an alternate pathway for Hcy remethylation. We hypothesized that BHMT is a major pathway for homocysteine removal in cases of hyperhomocysteinaemia (HHcy). Therefore, we measured betaine in plasma and tissues from patients and animal models of HHcy of genetic and acquired cause. Plasma was collected from patients presenting HHcy without any Hcy interfering treatment. Plasma and tissues were collected from rat models of HHcy induced by diet and from a mouse model of cystathionine β-synthase (CBS) deficiency. S-adenosyl-methionine (AdoMet), S-adenosyl-homocysteine (AdoHcy), methionine, betaine and dimethylglycine (DMG) were quantified by ESI-LC-MS/MS. mRNA expression was quantified using quantitative real-time (QRT)-PCR. For all patients with diverse causes of HHcy, plasma betaine concentrations were below the normal values of our laboratory. In the diet-induced HHcy rat model, betaine was decreased in all tissues analysed (liver, brain, heart). In the mouse CBS deficiency model, betaine was decreased in plasma, liver, heart and brain, but was conserved in kidney. Surprisingly, BHMT expression and activity was decreased in liver. However, in kidney, BHMT and SLC6A12 expression was increased in CBS-deficient mice. Chronic HHcy, irrespective of its cause, induces betaine depletion in plasma and tissues (liver, brain and heart), indicating a global decrease in the body betaine pool. In kidney, betaine concentrations were not affected, possibly due to overexpression of the betaine transporter SLC6A12 where betaine may be conserved because of its crucial role as an osmolyte.

  13. Specification for the VERA Depletion Benchmark Suite

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kang Seog [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-12-17

    CASL-X-2015-1014-000 iii Consortium for Advanced Simulation of LWRs EXECUTIVE SUMMARY The CASL neutronics simulator MPACT is under development for the neutronics and T-H coupled simulation for the pressurized water reactor. MPACT includes the ORIGEN-API and internal depletion module to perform depletion calculations based upon neutron-material reaction and radioactive decay. It is a challenge to validate the depletion capability because of the insufficient measured data. One of the detoured methods to validate it is to perform a code-to-code comparison for benchmark problems. In this study a depletion benchmark suite has been developed and a detailed guideline has been provided to obtain meaningful computational outcomes which can be used in the validation of the MPACT depletion capability.

  14. Identifying water mass depletion in Northern Iraq observed by GRACE

    Directory of Open Access Journals (Sweden)

    G. Mulder

    2014-10-01

    Full Text Available Observations acquired by Gravity Recovery And Climate Experiment (GRACE mission indicate a mass loss of 31 ± 3 km3 or 130 ± 14 mm in Northern Iraq between 2007 and 2009. This data is used as an independent validation of a hydrologic model of the region including lake mass variations. We developed a rainfall–runoff model for five tributaries of the Tigris River, based on local geology and climate conditions. Model inputs are precipitation from Tropical Rainfall Measurement Mission (TRMM observations, and potential evaporation from GLDAS model parameters. Our model includes a representation of the karstified aquifers that cause large natural groundwater variations in this region. Observed river discharges were used to calibrate our model. In order to get the total mass variations, we corrected for lake mass variations derived from Moderate Resolution Imaging Spectroradiometer (MODIS in combination with satellite altimetry and some in-situ data. Our rainfall–runoff model confirms that Northern Iraq suffered a drought between 2007 and 2009 and is consistent with the mass loss observed by GRACE over that period. Also, GRACE observed the annual cycle predicted by the rainfall–runoff model. The total mass depletion seen by GRACE between 2007 and 2009 is mainly explained by a lake mass depletion of 74 ± 4 mm and a natural groundwater depletion of 37 ± 6 mm. Our findings indicate that man-made groundwater extraction has a minor influence in this region while depletion of lake mass and geology play a key role.

  15. DURABILITY OF DEPLETED URANIUM AGGREGATES (DUAGG) IN DUCRETE SHIELDING APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Mattus, Catherine H.; Dole, Leslie R.

    2003-02-27

    The depleted uranium (DU) inventory in the United States exceeds 500,000 metric tonnes. To evaluate the possibilities for reuse of this stockpile of DU, the U.S. Department of Energy (DOE) has created a research and development program to address the disposition of its DU(1). One potential use for this stockpile material is in the fabrication of nuclear shielding casks for the storage, transport, and disposal of spent nuclear fuels. The use of the DU-based shielding would reduce the size and weight of the casks while allowing a level of protection from neutrons and gamma rays comparable to that afforded by steel and concrete. DUAGG (depleted uranium aggregate) is formed of depleted uranium dioxide (DUO2) sintered with a synthetic-basalt-based binder. This study was designed to investigate possible deleterious reactions that could occur between the cement paste and the DUAGG. After 13 months of exposure to a cement pore solution, no deleterious expansive mineral phases were observed to form either with the DUO2 or with the simulated-basalt sintering phases. In the early stages of these exposure tests, Oak Ridge National Laboratory preliminary results confirm that the surface reactions of this aggregate proceed more slowly than expected. This finding may indicate that DUAGG/DUCRETE (depleted uranium concrete) casks could have service lives sufficient to meet the projected needs of DOE and the commercial nuclear power industry.

  16. Sedimentary Characterization of Nazca Ridge ODP Site 1237: Plio-Pleistocene Record of Continental Erosion and Bottom Water Influence

    Science.gov (United States)

    Dileo, K. V.; Joseph, L. H.

    2005-12-01

    Ocean Drilling Program (ODP) Site 1237 (16°0.421'S, 76°22.685'W), drilled ~140 km off the east coast of Peru on the easternmost flank of Nazca Ridge, provides an opportunity to study climatic shifts in the southeastern Pacific Ocean over the last thirty million years. Sediment deposition at this location has been influenced by movement through various oceanic current systems, from a relatively low productivity open ocean setting to a high productivity upwelling zone along the coast of Peru, as the tectonic plate subducts under South America. Today, near the eastern edge of the Peru-Chile current at a water depth of 3212 m, this site is located in the transition zone between Antarctic Circumpolar Deep Water and Pacific Central Water and is close enough to the continent to collect terrigenous sediment from South America. Plio-Pleistocene sediment (~100 mcd) from Site 1237 is comprised of white to light greenish gray clayey nannofossil ooze (Lithologic Unit IB) and clay to ooze with similar percentages of clay minerals, nannofossils, and diatoms (Unit IA). Shipboard results indicated linear sedimentation rates of ~20-30 m/my and siliciclastic mass accumulation rates (MARs) of ~1 g/cm2/ky during this time period. Approximately 90 Plio-Pleistocene samples were analyzed for bulk magnetic susceptibility, anisotropy of magnetic susceptibility (AMS; P' and T), organic carbon content, and calcium carbonate content to aid in interpretation of climatic and oceanic conditions that existed at the time of sediment deposition. Bulk magnetic susceptibility values are very low (10-6 to 10-7 SI, or negative) at the base of the record through ~60 mcd(~3 Ma), gradually increase to a peak value of ~3.7 x 10-4 SI at ~22 mcd (~1 Ma), decreasing and subsequently increasing for the remainder of the record. In the upper part of the record (above 60 mcd) where bulk magnetic susceptibility values are >10-6, P' values (strength of magnetic susceptibility), which can be used to interpret the

  17. Major early Eocene carbon cycle perturbations and changes in planktic foraminiferal assemblages from the southeast Atlantic Ocean (ODP Site 1263)

    Science.gov (United States)

    Luciani, Valeria; D'Onofrio, Roberta; Dickens, Gerald Roy; Wade, Bridget

    2017-04-01

    On a paleoclimatic perspective the early Paleogene represents one of the most interesting and dynamic intervals of the Earth's history. Present record indicates that the Earth climate system reached its Cenozoic maximum peak of global warming and probably of pCO2 during the early Eocene climatic optimum (EECO, 49-53 Ma). Superimposed to the general trend, our planet experienced short-term ( 40-200 kyr) repeated peaks in global temperatures and major changes in the carbon cycle, known as hyperthermals. Great scientific interest has been focused on the early Paleogene hyperthermal events, given the assumed similarity with the current climatic scenario. Less attention has been dedicated to the EECO long lasting perturbation of extraordinary warming thus many characters of this interval still remain largely unconstrained, especially as for the biotic response. We present here results on early Eocene planktic foraminiferal analysis from the southeast Atlantic Ocean Drilling Program (ODP) Site 1263 (Walvis Ridge, Leg 208) to explore possible relationship between changes in assemblages and carbon cycle perturbation. The time interval is of particular interest for an abrupt switch occurred at low-latitude of the northern hemisphere between two important calcifiers of the tropical-subtropical early Paleogene oceans, the genera Morozovella and Acarinina at the carbon isotopic excursion known as J event, at the EECO onset. Precisely, the relative abundance of Morozovella permanently decreased by at least half, along with a progressive decrease in the number of species. Concomitantly, Acarinina almost doubled its abundance and diversified. Site 1263 was located during the early Eocene at a latitude of 40° south therefore representing a temperate setting of southern hemisphere not yet explored for planktic foraminiferal changes. We document a permanent decrease in Morozovella abundance at the beginning of the EECO, although this decline is delayed by 165 kyr with respect to

  18. Possible ozone depletions following nuclear explosions

    Science.gov (United States)

    Whitten, R. C.; Borucki, W. J.; Turco, R. P.

    1975-01-01

    The degree of depletion of the ozone layer ensuing after delivery of strategic nuclear warheads (5000 and 10,000 Mton) due to production of nitrogen oxides is theoretically assessed. Strong depletions are calculated for 16-km and 26-km altitudes, peaking 1-2 months after detonation and lasting for three years, while a significant depletion at 36 km would peak after one year. Assuming the explosions occur between 30 and 70 deg N, these effects should be much more pronounced in this region than over the Northern Hemisphere as a whole. It is concluded that Hampson's concern on this matter (1974) is well-founded.-

  19. Southern high-latitude terrestrial climate change during the Palaeocene-Eocene derived from a marine pollen record (ODP Site 1172, East Tasman Plateau)

    Science.gov (United States)

    Contreras, L.; Pross, J.; Bijl, P. K.; O'Hara, R. B.; Raine, J. I.; Sluijs, A.; Brinkhuis, H.

    2014-07-01

    Reconstructing the early Palaeogene climate dynamics of terrestrial settings in the high southern latitudes is important to assess the role of high-latitude physical and biogeochemical processes in the global climate system. However, whereas a number of high-quality Palaeogene climate records has become available for the marine realm of the high southern latitudes over the recent past, the long-term evolution of coeval terrestrial climates and ecosystems is yet poorly known. We here explore the climate and vegetation dynamics on Tasmania from the middle Palaeocene to the early Eocene (60.7-54.2 Ma) based on a sporomorph record from Ocean Drilling Program (ODP) Site 1172 on the East Tasman Plateau. Our results show that three distinctly different vegetation types thrived on Tasmania under a high-precipitation regime during the middle Palaeocene to early Eocene, with each type representing different temperature conditions: (i) warm-temperate forests dominated by gymnosperms that were dominant during the middle and late Palaeocene (excluding the middle/late Palaeocene transition); (ii) cool-temperate forests dominated by southern beech (Nothofagus) and araucarians that transiently prevailed across the middle/late Palaeocene transition interval (~ 59.5 to ~ 59.0 Ma); and (iii) paratropical forests rich in ferns that were established during and in the wake of the Palaeocene-Eocene Thermal Maximum (PETM). The transient establishment of cool-temperate forests lacking any frost-sensitive elements (i.e. palms and cycads) across the middle/late Palaeocene transition interval indicates markedly cooler conditions, with the occurrence of frosts in winter, on Tasmania during that time. The integration of our sporomorph data with previously published TEX86-based sea-surface temperatures from ODP Site 1172 documents that the vegetation dynamics on Tasmania were closely linked with the temperature evolution in the Tasman sector of the Southwest Pacific region. Moreover, the

  20. Southern high-latitude terrestrial climate change during the Paleocene-Eocene derived from a marine pollen record (ODP Site 1172, East Tasman Plateau)

    Science.gov (United States)

    Contreras, L.; Pross, J.; Bijl, P. K.; O'Hara, R. B.; Raine, J. I.; Sluijs, A.; Brinkhuis, H.

    2014-01-01

    Reconstructing the early Paleogene climate dynamics of terrestrial settings in the high southern latitudes is important to assess the role of high-latitude physical and biogeochemical processes in the global climate system. However, whereas a number of high-quality Paleogene climate records has become available for the marine realm of the high southern latitudes over the recent past, the long-term evolution of coeval terrestrial climates and ecosystems is yet poorly known. We here explore the climate and vegetation dynamics on Tasmania from the middle Paleocene to the early Eocene (60.7-54.2 Ma) based on a sporomorph record from Ocean Drilling Program (ODP) Site 1172 on the East Tasman Plateau. Our results show that three distinctly different vegetation types thrived on Tasmania under a high-precipitation regime during the middle Paleocene to early Eocene, with each type representing different temperature conditions: (i) warm-temperate forests dominated by gymnosperms that were dominant during the middle and late Paleocene; (ii) cool-temperate forests dominated by southern beech (Nothofagus) and araucarians across the middle/late Paleocene transition interval (~59.5 to ~59.0 Ma); and (iii) paratropical forests rich in ferns that were established during and in the wake of the Paleocene-Eocene Thermal Maximum (PETM). The transient establishment of cool-temperate forests lacking any frost-sensitive elements (i.e., palms and cycads) across the middle/late Paleocene transition interval indicates markedly cooler conditions, with the occurrence of frosts in winter, on Tasmania during that time. The integration of our sporomorph data with previously published TEX86-based sea-surface temperatures from ODP Site 1172 documents that the vegetation dynamics on Tasmania were closely linked with the temperature evolution in the Tasman sector of the Southwest Pacific region. Moreover, the comparison of our season-specific climate estimates for the sporomorph assemblages from ODP

  1. Southern high-latitude terrestrial climate change during the Paleocene–Eocene derived from a marine pollen record (ODP Site 1172, East Tasman Plateau

    Directory of Open Access Journals (Sweden)

    L. Contreras

    2014-01-01

    Full Text Available Reconstructing the early Paleogene climate dynamics of terrestrial settings in the high southern latitudes is important to assess the role of high-latitude physical and biogeochemical processes in the global climate system. However, whereas a number of high-quality Paleogene climate records has become available for the marine realm of the high southern latitudes over the recent past, the long-term evolution of coeval terrestrial climates and ecosystems is yet poorly known. We here explore the climate and vegetation dynamics on Tasmania from the middle Paleocene to the early Eocene (60.7–54.2 Ma based on a sporomorph record from Ocean Drilling Program (ODP Site 1172 on the East Tasman Plateau. Our results show that three distinctly different vegetation types thrived on Tasmania under a high-precipitation regime during the middle Paleocene to early Eocene, with each type representing different temperature conditions: (i warm-temperate forests dominated by gymnosperms that were dominant during the middle and late Paleocene; (ii cool-temperate forests dominated by southern beech (Nothofagus and araucarians across the middle/late Paleocene transition interval (~59.5 to ~59.0 Ma; and (iii paratropical forests rich in ferns that were established during and in the wake of the Paleocene–Eocene Thermal Maximum (PETM. The transient establishment of cool-temperate forests lacking any frost-sensitive elements (i.e., palms and cycads across the middle/late Paleocene transition interval indicates markedly cooler conditions, with the occurrence of frosts in winter, on Tasmania during that time. The integration of our sporomorph data with previously published TEX86-based sea-surface temperatures from ODP Site 1172 documents that the vegetation dynamics on Tasmania were closely linked with the temperature evolution in the Tasman sector of the Southwest Pacific region. Moreover, the comparison of our season-specific climate estimates for the sporomorph

  2. Polar stratospheric clouds and ozone depletion

    Science.gov (United States)

    Toon, Owen B.; Turco, Richard P.

    1991-01-01

    A review is presented of investigations into the correlation between the depletion of ozone and the formation of polar stratospheric clouds (PSCs). Satellite measurements from Nimbus 7 showed that over the years the depletion from austral spring to austral spring has generally worsened. Approximately 70 percent of the ozone above Antarctica, which equals about 3 percent of the earth's ozone, is lost during September and October. Various hypotheses for ozone depletion are discussed including the theory suggesting that chlorine compounds might be responsible for the ozone hole, whereby chlorine enters the atmosphere as a component of chlorofluorocarbons produced by humans. The three types of PSCs, nitric acid trihydrate, slowly cooling water-ice, and rapidly cooling water-ice clouds act as important components of the Antarctic ozone depletion. It is indicated that destruction of the ozone will be more severe each year for the next few decades, leading to a doubling in area of the Antarctic ozone hole.

  3. [Hepatomioneuropathy secondary to mitochondrial DNA depletion].

    Science.gov (United States)

    Blanco-Barca, M O; Gómez-Lado, C; Campos-González, Y; Castro-Gago, M

    2007-04-01

    Mitochondrial DNA depletion (mtDNA) is an highly heterogeneous condition characterized by a decreased number of mtDNA copies. The patient is a 22-month-old girl with generalized hypotonia, marked weakness, respiratory failure, arterial hypertension, hyperlactacidemia, hepatosplenomegaly and mild hypertransaminasemia without hepatic failure neither hypoketotic hypoglycemia. Electromyographic findings were consistent with neuromyopathy and muscle biopsy suggested a neurogenic atrophy. Electron microscopy revealed lipid droplets, subsarcolemmal accumulation of mitochondrias and glycogen granules. Respiratory chain enzime activities were normal. Genetic study in muscle showed mtDNA depletion, and the diagnosis of spinal muscular atrophy caused by survival motoneuron gene deletion was excluded. This case might be a novel phenotype of mtDNA depletion which could be named hepatomioneuropatyc form. A normal result of respiratory chain enzimes in muscle doesn't excluded mtDNA depletion.

  4. Depleted bulk heterojunction colloidal quantum dot photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Barkhouse, D.A.R. [Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Road, Toronto, Ontario M5S 3G4 (Canada); IBM Thomas J. Watson Research Center, Kitchawan Road, Yorktown Heights, NY, 10598 (United States); Debnath, Ratan; Kramer, Illan J.; Zhitomirsky, David; Levina, Larissa; Sargent, Edward H. [Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Road, Toronto, Ontario M5S 3G4 (Canada); Pattantyus-Abraham, Andras G. [Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Road, Toronto, Ontario M5S 3G4 (Canada); Quantum Solar Power Corporation, 1055 W. Hastings, Ste. 300, Vancouver, BC, V6E 2E9 (Canada); Etgar, Lioz; Graetzel, Michael [Laboratory for Photonics and Interfaces, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Swiss Federal Institute of Technology, CH-1015 Lausanne (Switzerland)

    2011-07-26

    The first solution-processed depleted bulk heterojunction colloidal quantum dot solar cells are presented. The architecture allows for high absorption with full depletion, thereby breaking the photon absorption/carrier extraction compromise inherent in planar devices. A record power conversion of 5.5% under simulated AM 1.5 illumination conditions is reported. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Depleted Bulk Heterojunction Colloidal Quantum Dot Photovoltaics

    KAUST Repository

    Barkhouse, D. Aaron R.

    2011-05-26

    The first solution-processed depleted bulk heterojunction colloidal quantum dot solar cells are presented. The architecture allows for high absorption with full depletion, thereby breaking the photon absorption/carrier extraction compromise inherent in planar devices. A record power conversion of 5.5% under simulated AM 1.5 illumination conditions is reported. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. A theoretical model of atmospheric ozone depletion

    Science.gov (United States)

    Midya, S. K.; Jana, P. K.; Lahiri, T.

    1994-01-01

    A critical study on different ozone depletion and formation processes has been made and following important results are obtained: (i) From analysis it is shown that O3 concentration will decrease very minutely with time for normal atmosphere when [O], [O2] and UV-radiation remain constant. (ii) An empirical equation is established theoretically between the variation of ozone concentration and time. (iii) Special ozone depletion processes are responsible for the dramatic decrease of O3-concentration at Antarctica.

  7. The potential for ozone depletion in the Arctic polar stratosphere

    Science.gov (United States)

    Brune, W. H.; Anderson, J. G.; Toohey, D. W.; Fahey, D. W.; Kawa, S. R.; Poole, L. R.

    1991-01-01

    The nature of the Arctic polar stratosphere is observed to be similar in many respects to that of the Antarctic polar stratosphere, where an ozone hole has been identified. Most of the available chlorine (CHl and ClONO2) was converted by reactions on polar stratospheric clouds to reactive ClO and Cl2O2 thoroughout the Arctic polar vortex before midwinter. Reactive nitrogen was converted to HNO3, and some, with spatial inhomogeneity, fell out of the stratosphere. These chemical changes ensured characteristic ozone losses of 10 to 15 percent at altitudes inside the polar vortex where polar stratospheric clouds had occurred. These local losses can translate into 5 to 8 percent losses in the vertical column abundance of ozone. As the amount of stratospheric chlorine inevitably increases by 50 percent over the next two decades, ozone losses recognizable as an ozone hole may well appear.

  8. Anatomy of Depleted Interplanetary Coronal Mass Ejections

    Science.gov (United States)

    Kocher, M.; Lepri, S. T.; Landi, E.; Zhao, L.; Manchester, W. B., IV

    2017-01-01

    We report a subset of interplanetary coronal mass ejections (ICMEs) containing distinct periods of anomalous heavy-ion charge state composition and peculiar ion thermal properties measured by ACE/SWICS from 1998 to 2011. We label them “depleted ICMEs,” identified by the presence of intervals where C6+/C5+ and O7+/O6+ depart from the direct correlation expected after their freeze-in heights. These anomalous intervals within the depleted ICMEs are referred to as “Depletion Regions.” We find that a depleted ICME would be indistinguishable from all other ICMEs in the absence of the Depletion Region, which has the defining property of significantly low abundances of fully charged species of helium, carbon, oxygen, and nitrogen. Similar anomalies in the slow solar wind were discussed by Zhao et al. We explore two possibilities for the source of the Depletion Region associated with magnetic reconnection in the tail of a CME, using CME simulations of the evolution of two Earth-bound CMEs described by Manchester et al.

  9. Vegetation and climate dynamics of southern Chile during the past 50,000 years: results of ODP Site 1233 pollen analysis

    Science.gov (United States)

    Heusser, Linda; Heusser, Cal; Pisias, Nicklas

    2006-03-01

    High-resolution pollen data from ODP Site 1233 (41°0.005S, 74°26.992W, 838 m water depth) provide a continuous, chronostratigraphically controlled ˜50,000-yr record of regional changes in vegetation from temperate South America. Deposited ˜38 km west of the transition from northern, summer-green, lowland forest to southern evergreen rain forest, the 135 m core documents the comparatively brief Holocene development of thermophilous vegetation (Lowland Deciduous Beech Forest and Valdivian Evergreen Forest), and the expansion of glacial, subantarctic vegetation (North Patagonian Evergreen Forest-Subantarctic Parkland) during Marine Isotope State (MIS) 2 and 3. Systematic variability in these terrestrial climate proxies that reflect latitudinal movement of the southern westerlies is mirrored in co-eval ocean conditions inferred from radiolaria census data and in Antarctic climate records.

  10. A silicon depleted North Atlantic since the Palaeogene: Evidence from sponge and radiolarian silicon isotopes

    Science.gov (United States)

    Fontorbe, Guillaume; Frings, Patrick J.; De La Rocha, Christina L.; Hendry, Katharine R.; Conley, Daniel J.

    2016-11-01

    Despite being one of Earth's major geochemical cycles, the evolution of the silicon cycle has received little attention and changes in oceanic dissolved silica (DSi) concentration through geologic time remain poorly constrained. Silicon isotope ratios (expressed as δ30Si) in marine microfossils are becoming increasingly recognised for their ability to provide insight into silicon cycling. In particular, the δ30Si of siliceous sponge spicules has been demonstrated to be a useful proxy for past DSi concentrations. We analysed δ30Si in radiolarian tests and sponge spicules from the Blake Nose Palaeoceanographic Transect (ODP Leg 171B) spanning the Palaeocene-Eocene (ca. 60-30 Ma). Our δ30Si results range from +0.32 to + 1.67 ‰ and -0.48 to + 0.63 ‰ for the radiolarian and sponge records, respectively. Using an established relationship between ambient dissolved Si (DSi) concentrations and the magnitude of silicon isotope fractionation in siliceous sponges, we demonstrate that the Western North Atlantic was DSi deplete during the Palaeocene-Eocene throughout the water column, a conclusion that is robust to a range of assumptions and uncertainties. These data can constitute constraints on reconstructions of past-ocean circulation. Previous work has suggested ocean DSi concentrations were higher than modern ocean concentrations prior to the Cenozoic and has posited a drawdown during the Early Palaeogene due to the evolutionary expansion of diatoms. Our results challenge such an interpretation. We suggest here that if such a global decrease in oceanic DSi concentrations occurred, it must predate 60 Ma.

  11. Insights into magmatic processes and hydrothermal alteration of in situ superfast spreading ocean crust at ODP/IODP site 1256 from a cluster analysis of rock magnetic properties

    Science.gov (United States)

    Dekkers, Mark J.; Heslop, David; Herrero-Bervera, Emilio; Acton, Gary; Krasa, David

    2014-08-01

    analyze magnetic properties from Ocean Drilling Program (ODP)/Integrated ODP (IODP) Hole 1256D (6°44.1' N, 91°56.1' W) on the Cocos Plate in ˜15.2 Ma oceanic crust generated by superfast seafloor spreading, the only drill hole that has sampled all three oceanic crust layers in a tectonically undisturbed setting. Fuzzy c-means cluster analysis and nonlinear mapping are utilized to study down-hole trends in the ratio of the saturation remanent magnetization and the saturation magnetization, the coercive force, the ratio of the remanent coercive force and coercive force, the low-field magnetic susceptibility, and the Curie temperature, to evaluate the effects of magmatic and hydrothermal processes on magnetic properties. A statistically robust five cluster solution separates the data predominantly into three clusters that express increasing hydrothermal alteration of the lavas, which differ from two distinct clusters mainly representing the dikes and gabbros. Extensive alteration can obliterate magnetic property differences between lavas, dikes, and gabbros. The imprint of thermochemical alteration on the iron-titanium oxides is only partially related to the porosity of the rocks. Thus, the analysis complements interpretation based on electrofacies analysis. All clusters display rock magnetic characteristics compatible with an ability to retain a stable natural remanent magnetization suggesting that the entire sampled sequence of ocean crust can contribute to marine magnetic anomalies. Paleointensity determination is difficult because of the propensity of oxyexsolution during laboratory heating and/or the presence of intergrowths. The upper part of the extrusive sequence, the granoblastic dikes, and moderately altered gabbros may contain a comparatively uncontaminated thermoremanent magnetization.

  12. Depletion mapping and constrained optimization to support managing groundwater extraction

    Science.gov (United States)

    Fienen, Michael N.; Bradbury, Kenneth R.; Kniffin, Maribeth; Barlow, Paul M.

    2017-01-01

    Groundwater models often serve as management tools to evaluate competing water uses including ecosystems, irrigated agriculture, industry, municipal supply, and others. Depletion potential mapping—showing the model-calculated potential impacts that wells have on stream baseflow - can form the basis for multiple potential management approaches in an oversubscribed basin. Specific management approaches can include scenarios proposed by stakeholders, systematic changes in well pumping based on depletion potential, and formal constrained optimization, which can be used to quantify the tradeoff between water use and stream baseflow. Variables such as the maximum amount of reduction allowed in each well and various groupings of wells using, for example, K-means clustering considering spatial proximity and depletion potential are considered. These approaches provide a potential starting point and guidance for resource managers and stakeholders to make decisions about groundwater management in a basin, spreading responsibility in different ways. We illustrate these approaches in the Little Plover River basin in central Wisconsin, United States—home to a rich agricultural tradition, with farmland and urban areas both in close proximity to a groundwater-dependent trout stream. Groundwater withdrawals have reduced baseflow supplying the Little Plover River below a legally established minimum. The techniques in this work were developed in response to engaged stakeholders with various interests and goals for the basin. They sought to develop a collaborative management plan at a watershed scale that restores the flow rate in the river in a manner that incorporates principles of shared governance and results in effective and minimally disruptive changes in groundwater extraction practices.

  13. Miocene climate as recorded on slope carbonates : examples from Malta (Central Mediterranean) and Northeastern Australia (Marion Plateau, ODP LEG 194)

    Science.gov (United States)

    John, Cédric Michaël

    2003-08-01

    This study investigated the slope carbonates of two Miocene carbonate systems: the Maltese Islands (in the Central Mediterranean) and the Marion Plateau (Northeastern Australia, drilled during ODP Leg 194). The aim of the study was to trace the impact of the Miocene cooling steps (events Mi1-Mi6) in these carbonate systems, especially the Mi3 event, which took place around 13.6 Ma and deeply impacted the marine oxygen isotope record. This event also profoundly impacted oceanographic and climatic patterns, eventually leading to the establishment of the modern ice-house world. In particular, East Antarctica became ice covered at that period. The rational behind the present study was to investigate the impact that this event had on shallow water systems in order to complement the deep-sea record and hence acquire a more global perspective on Miocene climate change. The Maltese Islands were investigated for trends in bulk-rock carbon and oxygen isotopes, as well as bulk-rock mineralogy, clay minerals analysis and organic geochemisty. Results showed that the mid Miocene cooling event deeply impacted sedimentation at that location by changing sedimentation from carbonate to clay-rich sediments. Moreover, it was discovered that each phase of Antarctic glaciation, not just the major mid Miocene event, resulted in higher terrigenous input on Malta. Mass accumulation rates revealed that this was linked to increased runoff during periods when Antarctica was glaciated, and thus that the carbonate sediments were “diluted” by clay-rich sediments. The model subsequently developed to explain this implies feedback from Antarctic glaciations creating cold, dense air masses that push the ITCZ Northward, thus increasing precipitation on the North African subcontinent. Increased precipitation (or stronger African monsoon) accelerated continental weathering and runoff, thus bringing more terrigenous sediment to the paleo-location of the slope sediments of Malta. Spectral analysis of

  14. New Approach For Prediction Groundwater Depletion

    Science.gov (United States)

    Moustafa, Mahmoud

    2017-01-01

    Current approaches to quantify groundwater depletion involve water balance and satellite gravity. However, the water balance technique includes uncertain estimation of parameters such as evapotranspiration and runoff. The satellite method consumes time and effort. The work reported in this paper proposes using failure theory in a novel way to predict groundwater saturated thickness depletion. An important issue in the failure theory proposed is to determine the failure point (depletion case). The proposed technique uses depth of water as the net result of recharge/discharge processes in the aquifer to calculate remaining saturated thickness resulting from the applied pumping rates in an area to evaluate the groundwater depletion. Two parameters, the Weibull function and Bayes analysis were used to model and analyze collected data from 1962 to 2009. The proposed methodology was tested in a nonrenewable aquifer, with no recharge. Consequently, the continuous decline in water depth has been the main criterion used to estimate the depletion. The value of the proposed approach is to predict the probable effect of the current applied pumping rates on the saturated thickness based on the remaining saturated thickness data. The limitation of the suggested approach is that it assumes the applied management practices are constant during the prediction period. The study predicted that after 300 years there would be an 80% probability of the saturated aquifer which would be expected to be depleted. Lifetime or failure theory can give a simple alternative way to predict the remaining saturated thickness depletion with no time-consuming processes such as the sophisticated software required.

  15. Evolution of planktonic foraminifera and thermocline in the southern South China Sea since 12 Ma (ODP-184, Site 1143)

    Institute of Scientific and Technical Information of China (English)

    Ll; Baohua

    2001-01-01

    ., High-resolution records of the thermocline in the Okinawa trough since about 10000 aBP,Science in China, Ser. D, 2001, 44(3): 193-200.[12]Shipboard Scientific Party, Site 1143, in Proceedings of the ODP, Initial Reports 184 (CD-ROM) (eds. Wang, P., Prell, W.L., Blum, P. et al.), Ocean Drilling Program, Texas A&M University, College Station, 2000, 1-103.[13]Le, J., Shackleton, N. J., Carbonate dissolution fluctuation in the western Equatorial Pacific during the late Quaternary,Paleoceanography, 1992, 7(1): 21-42.[14]Bolli, H. M., Saunders, J. B., Oligocene to Holocene lower latitude planktonic foraminifera, in Plankton Stratigraphy (eds.Bolli, H. M., Saunders, J. B., Perch-Nielsen, K.), Cambridge: Cambridge University Press, 1985, 155-262.[15]Kennett, J. P., Srinivasan, M. S., Neogene Planktonic Foraminifera: A Phylogenic Atlas, New York: Hutchinson Ross Pub lishing Company, 1983, 1-265.[16]Berggren, W. A., Kent, D. V., Swisher, C. C. et al., A revised Cenozoic geochronology and chronostratigraphy, in Geo chronology Time Scales and Global Stratigraphic Correlation (eds. Berggren, W. A., Kent, D. V., Aubry, M. P. et al.),SEMP Special Publication, 1995, 54: 129-212.[17]Thompson, P. R., Bé, A. W. H., Duplessy, J. C. et al., Disappearance of pink-pigmented Globigerinoides ruber at 120,000yr BP in the Indian and Pacific Oceans, Nature, 1979, 280: 554-558.[18]Li, B., Chen, M. P., Zhao, Q. et al., Planktonic foraminiferal events and their paleoceanographic signifances in the south ern South China Sea since the last 800,000 years, Acta Micropaleontoligia Sinica (in Chinese with English abstract), 2001, 18(1): 1-9.[19]Wang, P., Xia, L., Wang, L. et al., Lower boundary of the marine Pleistocene in the northern shelf of the South China Sea,Acta Geologica Sinica (in Chinese with English abstract), 1991, 2:176-187.[20]Zhao, Q., Jian, Z., Li, B. et al., Microtektites in the deep sea core of South China Sea at 780,000 ys B.P. and its signifi cance

  16. Substitution of R502 in existing refrigerating, air-conditioning and heat pump systems with refrigerants of low ozone depletion potential in the Federal Republic of Germany; Ersatz von R 502 in bestehenden Kaelte-, Klima- und Waermepumpenanlagen in der Bundesrepublik Deutschland durch Kaeltemittel mit geringerem Ozonabbaupotential

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    The technical basics and the state of engineering for the substitution of R502 in existing refrigeration systems are described and explained. The report contains an overview of the current applications of R502 in the FRG, the presentation and discussion of existing substitutes, the presentation and valuations of research and experiences with the adaptation to alternative refrigerants, the presentation of the required infrastructure and a discussion of the technical feasibility. The conversion of existing systems to refrigerants of lower ozone depletion potential is in conclusion valuated with regard to its technical feasibility, environmental relevance and economic efficiency. (orig.) [Deutsch] Es werden die technischen Grundlagen und der Stand der Technik zum Ersatz von R502 in bestehenden Kaelteanlagen dargestellt und erlaeutert. Der Bericht beinhaltet einen Ueberblick ueber die derzeitige Anwendung von R502 in der BRD, die Vorstellung und Diskussion existierender Ersatzstoffe, die Darstellung und Bewertung der Forschung und Erfahrungen zu Umruestungen auf Ersatzstoffe, die Vorstellung der erforderlichen Infrastruktur und die Diskussion der technischen Durchfuehrbarkeit. Die Umstellung bestehender Anlagen auf Kaeltemittel mit geringerem Ozonabbaupotential wird abschliessend hinsichtlich der technischen Durchfuehrbarkeit, der Umweltrelevanz und der Wirtschaftlichkeit bewertet. (orig.)

  17. Substitution of R502 in existing refrigerating, air-conditioning and heat pump systems with refrigerants of low ozone depletion potential in the Federal Republic of Germany; Ersatz von R 502 in bestehenden Kaelte-, Klima- und Waermepumpenanlagen in der Bundesrepublik Deutschland durch Kaeltemittel mit geringerem Ozonabbaupotential

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    The technical basics and the state of engineering for the substitution of R502 in existing refrigeration systems are described and explained. The report contains an overview of the current applications of R502 in the FRG, the presentation and discussion of existing substitutes, the presentation and valuations of research and experiences with the adaptation to alternative refrigerants, the presentation of the required infrastructure and a discussion of the technical feasibility. The conversion of existing systems to refrigerants of lower ozone depletion potential is in conclusion valuated with regard to its technical feasibility, environmental relevance and economic efficiency. (orig.) [Deutsch] Es werden die technischen Grundlagen und der Stand der Technik zum Ersatz von R502 in bestehenden Kaelteanlagen dargestellt und erlaeutert. Der Bericht beinhaltet einen Ueberblick ueber die derzeitige Anwendung von R502 in der BRD, die Vorstellung und Diskussion existierender Ersatzstoffe, die Darstellung und Bewertung der Forschung und Erfahrungen zu Umruestungen auf Ersatzstoffe, die Vorstellung der erforderlichen Infrastruktur und die Diskussion der technischen Durchfuehrbarkeit. Die Umstellung bestehender Anlagen auf Kaeltemittel mit geringerem Ozonabbaupotential wird abschliessend hinsichtlich der technischen Durchfuehrbarkeit, der Umweltrelevanz und der Wirtschaftlichkeit bewertet. (orig.)

  18. Groundwater depletion embedded in international food trade

    Science.gov (United States)

    Dalin, Carole; Wada, Yoshihide; Kastner, Thomas; Puma, Michael J.

    2017-03-01

    Recent hydrological modelling and Earth observations have located and quantified alarming rates of groundwater depletion worldwide. This depletion is primarily due to water withdrawals for irrigation, but its connection with the main driver of irrigation, global food consumption, has not yet been explored. Here we show that approximately eleven per cent of non-renewable groundwater use for irrigation is embedded in international food trade, of which two-thirds are exported by Pakistan, the USA and India alone. Our quantification of groundwater depletion embedded in the world’s food trade is based on a combination of global, crop-specific estimates of non-renewable groundwater abstraction and international food trade data. A vast majority of the world’s population lives in countries sourcing nearly all their staple crop imports from partners who deplete groundwater to produce these crops, highlighting risks for global food and water security. Some countries, such as the USA, Mexico, Iran and China, are particularly exposed to these risks because they both produce and import food irrigated from rapidly depleting aquifers. Our results could help to improve the sustainability of global food production and groundwater resource management by identifying priority regions and agricultural products at risk as well as the end consumers of these products.

  19. The New MCNP6 Depletion Capability

    Energy Technology Data Exchange (ETDEWEB)

    Fensin, Michael Lorne [Los Alamos National Laboratory; James, Michael R. [Los Alamos National Laboratory; Hendricks, John S. [Los Alamos National Laboratory; Goorley, John T. [Los Alamos National Laboratory

    2012-06-19

    The first MCNP based inline Monte Carlo depletion capability was officially released from the Radiation Safety Information and Computational Center as MCNPX 2.6.0. Both the MCNP5 and MCNPX codes have historically provided a successful combinatorial geometry based, continuous energy, Monte Carlo radiation transport solution for advanced reactor modeling and simulation. However, due to separate development pathways, useful simulation capabilities were dispersed between both codes and not unified in a single technology. MCNP6, the next evolution in the MCNP suite of codes, now combines the capability of both simulation tools, as well as providing new advanced technology, in a single radiation transport code. We describe here the new capabilities of the MCNP6 depletion code dating from the official RSICC release MCNPX 2.6.0, reported previously, to the now current state of MCNP6. NEA/OECD benchmark results are also reported. The MCNP6 depletion capability enhancements beyond MCNPX 2.6.0 reported here include: (1) new performance enhancing parallel architecture that implements both shared and distributed memory constructs; (2) enhanced memory management that maximizes calculation fidelity; and (3) improved burnup physics for better nuclide prediction. MCNP6 depletion enables complete, relatively easy-to-use depletion calculations in a single Monte Carlo code. The enhancements described here help provide a powerful capability as well as dictate a path forward for future development to improve the usefulness of the technology.

  20. Ego depletion in visual perception: Ego-depleted viewers experience less ambiguous figure reversal.

    Science.gov (United States)

    Wimmer, Marina C; Stirk, Steven; Hancock, Peter J B

    2017-02-22

    This study examined the effects of ego depletion on ambiguous figure perception. Adults (N = 315) received an ego depletion task and were subsequently tested on their inhibitory control abilities that were indexed by the Stroop task (Experiment 1) and their ability to perceive both interpretations of ambiguous figures that was indexed by reversal (Experiment 2). Ego depletion had a very small effect on reducing inhibitory control (Cohen's d = .15) (Experiment 1). Ego-depleted participants had a tendency to take longer to respond in Stroop trials. In Experiment 2, ego depletion had small to medium effects on the experience of reversal. Ego-depleted viewers tended to take longer to reverse ambiguous figures (duration to first reversal) when naïve of the ambiguity and experienced less reversal both when naïve and informed of the ambiguity. Together, findings suggest that ego depletion has small effects on inhibitory control and small to medium effects on bottom-up and top-down perceptual processes. The depletion of cognitive resources can reduce our visual perceptual experience.

  1. The modality effect of ego depletion: Auditory task modality reduces ego depletion.

    Science.gov (United States)

    Li, Qiong; Wang, Zhenhong

    2016-08-01

    An initial act of self-control that impairs subsequent acts of self-control is called ego depletion. The ego depletion phenomenon has been observed consistently. The modality effect refers to the effect of the presentation modality on the processing of stimuli. The modality effect was also robustly found in a large body of research. However, no study to date has examined the modality effects of ego depletion. This issue was addressed in the current study. In Experiment 1, after all participants completed a handgrip task, one group's participants completed a visual attention regulation task and the other group's participants completed an auditory attention regulation task, and then all participants again completed a handgrip task. The ego depletion phenomenon was observed in both the visual and the auditory attention regulation task. Moreover, participants who completed the visual task performed worse on the handgrip task than participants who completed the auditory task, which indicated that there was high ego depletion in the visual task condition. In Experiment 2, participants completed an initial task that either did or did not deplete self-control resources, and then they completed a second visual or auditory attention control task. The results indicated that depleted participants performed better on the auditory attention control task than the visual attention control task. These findings suggest that altering task modality may reduce ego depletion.

  2. Plasmonic nanoprobes for stimulated emission depletion microscopy

    CERN Document Server

    Cortes, Emiliano; Sinclair, Hugo G; Guldbrand, Stina; Peveler, William J; Davies, Timothy; Parrinello, Simona; Görlitz, Frederik; Dunsby, Chris; Neil, Mark A A; Sivan, Yonatan; Parkin, Ivan P; French, Paul M; Maier, Stefan A

    2016-01-01

    Plasmonic nanoparticles influence the absorption and emission processes of nearby emitters due to local enhancements of the illuminating radiation and the photonic density of states. Here, we use the plasmon resonance of metal nanoparticles in order to enhance the stimulated depletion of excited molecules for super-resolved microscopy. We demonstrate stimulated emission depletion (STED) microscopy with gold nanorods with a long axis of only 26 nm and a width of 8 nm that provide an enhancement of the resolution compared to fluorescent-only probes without plasmonic components irradiated with the same depletion power. These novel nanoparticle-assisted STED probes represent a ~2x10^3 reduction in probe volume compared to previously used nanoparticles and we demonstrate their application to the first plasmon-assisted STED cellular imaging. We also discuss their current limitations.

  3. Molten-Salt Depleted-Uranium Reactor

    CERN Document Server

    Dong, Bao-Guo; Gu, Ji-Yuan

    2015-01-01

    The supercritical, reactor core melting and nuclear fuel leaking accidents have troubled fission reactors for decades, and greatly limit their extensive applications. Now these troubles are still open. Here we first show a possible perfect reactor, Molten-Salt Depleted-Uranium Reactor which is no above accident trouble. We found this reactor could be realized in practical applications in terms of all of the scientific principle, principle of operation, technology, and engineering. Our results demonstrate how these reactors can possess and realize extraordinary excellent characteristics, no prompt critical, long-term safe and stable operation with negative feedback, closed uranium-plutonium cycle chain within the vessel, normal operation only with depleted-uranium, and depleted-uranium high burnup in reality, to realize with fission nuclear energy sufficiently satisfying humanity long-term energy resource needs, as well as thoroughly solve the challenges of nuclear criticality safety, uranium resource insuffic...

  4. Self-regulation, ego depletion, and inhibition.

    Science.gov (United States)

    Baumeister, Roy F

    2014-12-01

    Inhibition is a major form of self-regulation. As such, it depends on self-awareness and comparing oneself to standards and is also susceptible to fluctuations in willpower resources. Ego depletion is the state of reduced willpower caused by prior exertion of self-control. Ego depletion undermines inhibition both because restraints are weaker and because urges are felt more intensely than usual. Conscious inhibition of desires is a pervasive feature of everyday life and may be a requirement of life in civilized, cultural society, and in that sense it goes to the evolved core of human nature. Intentional inhibition not only restrains antisocial impulses but can also facilitate optimal performance, such as during test taking. Self-regulation and ego depletion- may also affect less intentional forms of inhibition, even chronic tendencies to inhibit. Broadly stated, inhibition is necessary for human social life and nearly all societies encourage and enforce it.

  5. Depletion of the nuclear Fermi sea

    CERN Document Server

    Rios, A; Dickhoff, W H

    2009-01-01

    The short-range and tensor components of the bare nucleon-nucleon interaction induce a sizeable depletion of low momenta in the ground state of a nuclear many-body system. The self-consistent Green's function method within the ladder approximation provides an \\textit{ab-initio} description of correlated nuclear systems that accounts properly for these effects. The momentum distribution predicted by this approach is analyzed in detail, with emphasis on the depletion of the lowest momentum state. The temperature, density, and nucleon asymmetry (isospin) dependence of the depletion of the Fermi sea is clarified. A connection is established between the momentum distribution and the time-ordered components of the self-energy, which allows for an improved interpretation of the results. The dependence on the underlying nucleon-nucleon interaction provides quantitative estimates of the importance of short-range and tensor correlations in nuclear systems.

  6. Inhomogeneous depletion of oxygen ions in metal oxide nanoparticles

    Science.gov (United States)

    Vykhodets, Vladimir B.; Jarvis, Emily A. A.; Kurennykh, Tatiana E.; Beketov, Igor V.; Obukhov, Sviatoslav I.; Samatov, Oleg M.; Medvedev, Anatoly I.; Davletshin, Andrey E.; Whyte, Travis H.

    2016-02-01

    Zirconia and yttria stabilized zirconia (YSZ) have multiple uses, including catalysis, fuel cells, dental applications, and thermal coatings. We employ nuclear reaction analysis to determine elemental composition of YSZ nanoparticles synthesized by laser evaporation including 18O studies to distinguish between oxide and adsorbed oxygen content as a function of surface area. We see dramatic deviation from stoichiometry that can be traced to loss of oxygen from the oxide near the surface of these nanopowders. Density functional calculations are coupled with these experimental studies to explore the electronic structure of nonstoichiometric surfaces achieved through depletion of oxygen. Our results show oxygen-depleted surfaces present under oxygen potentials where stoichiometric, oxygen-terminated surfaces would be favored thermodynamically for crystalline systems. Oxygen depletion at nanopowder surfaces can create effective two-dimensional surface metallic states while maintaining stoichiometry in the underlying nanoparticle core. This insight into nanopowder surfaces applies to dissimilar oxides of aluminum and zirconium indicating synthesis conditions may be more influential than the inherent oxide properties and displaying need for distinct models for nanopowders of these important engineering materials where surface chemistry dominates performance.

  7. Regional strategies for the accelerating global problem of groundwater depletion

    Science.gov (United States)

    Aeschbach-Hertig, Werner; Gleeson, Tom

    2012-12-01

    Groundwater--the world's largest freshwater resource--is critically important for irrigated agriculture and hence for global food security. Yet depletion is widespread in large groundwater systems in both semi-arid and humid regions of the world. Excessive extraction for irrigation where groundwater is slowly renewed is the main cause of the depletion, and climate change has the potential to exacerbate the problem in some regions. Globally aggregated groundwater depletion contributes to sea-level rise, and has accelerated markedly since the mid-twentieth century. But its impacts on water resources are more obvious at the regional scale, for example in agriculturally important parts of India, China and the United States. Food production in such regions can only be made sustainable in the long term if groundwater levels are stabilized. To this end, a transformation is required in how we value, manage and characterize groundwater systems. Technical approaches--such as water diversion, artificial groundwater recharge and efficient irrigation--have failed to balance regional groundwater budgets. They need to be complemented by more comprehensive strategies that are adapted to the specific social, economic, political and environmental settings of each region.

  8. Macrophage depletion disrupts immune balance and energy homeostasis.

    Science.gov (United States)

    Lee, Bonggi; Qiao, Liping; Kinney, Brice; Feng, Gen-Sheng; Shao, Jianhua

    2014-01-01

    Increased macrophage infiltration in tissues including white adipose tissue and skeletal muscle has been recognized as a pro-inflammatory factor that impairs insulin sensitivity in obesity. However, the relationship between tissue macrophages and energy metabolism under non-obese physiological conditions is not clear. To study a homeostatic role of macrophages in energy homeostasis, we depleted tissue macrophages in adult mice through conditional expression of diphtheria toxin (DT) receptor and DT-induced apoptosis. Macrophage depletion robustly reduced body fat mass due to reduced energy intake. These phenotypes were reversed after macrophage recovery. As a potential mechanism, severe hypothalamic and systemic inflammation was induced by neutrophil (NE) infiltration in the absence of macrophages. In addition, macrophage depletion dramatically increased circulating granulocyte colony-stimulating factor (G-CSF) which is indispensable for NE production and tissue infiltration. Our in vitro study further revealed that macrophages directly suppress G-CSF gene expression. Therefore, our study indicates that macrophages may play a critical role in integrating immune balance and energy homeostasis under physiological conditions.

  9. Macrophage depletion disrupts immune balance and energy homeostasis.

    Directory of Open Access Journals (Sweden)

    Bonggi Lee

    Full Text Available Increased macrophage infiltration in tissues including white adipose tissue and skeletal muscle has been recognized as a pro-inflammatory factor that impairs insulin sensitivity in obesity. However, the relationship between tissue macrophages and energy metabolism under non-obese physiological conditions is not clear. To study a homeostatic role of macrophages in energy homeostasis, we depleted tissue macrophages in adult mice through conditional expression of diphtheria toxin (DT receptor and DT-induced apoptosis. Macrophage depletion robustly reduced body fat mass due to reduced energy intake. These phenotypes were reversed after macrophage recovery. As a potential mechanism, severe hypothalamic and systemic inflammation was induced by neutrophil (NE infiltration in the absence of macrophages. In addition, macrophage depletion dramatically increased circulating granulocyte colony-stimulating factor (G-CSF which is indispensable for NE production and tissue infiltration. Our in vitro study further revealed that macrophages directly suppress G-CSF gene expression. Therefore, our study indicates that macrophages may play a critical role in integrating immune balance and energy homeostasis under physiological conditions.

  10. Sensitivity study of control rod depletion coefficients

    OpenAIRE

    Blomberg, Joel

    2015-01-01

    This report investigates the sensitivity of the control rod depletion coefficients, Sg, to different input parameters and how this affects the accumulated 10B depletion, β. Currently the coefficients are generated with PHOENIX4, but the geometries can be more accurately simulated in McScram. McScram is used to calculate Control Rod Worth, which in turn is used to calculate Nuclear End Of Life, and Sg cannot be generated in the current version of McScram. Therefore, it is also analyzed whether...

  11. Contrasts between Antarctic and Arctic ozone depletion.

    Science.gov (United States)

    Solomon, Susan; Portmann, Robert W; Thompson, David W J

    2007-01-09

    This work surveys the depth and character of ozone depletion in the Antarctic and Arctic using available long balloon-borne and ground-based records that cover multiple decades from ground-based sites. Such data reveal changes in the range of ozone values including the extremes observed as polar air passes over the stations. Antarctic ozone observations reveal widespread and massive local depletion in the heart of the ozone "hole" region near 18 km, frequently exceeding 90%. Although some ozone losses are apparent in the Arctic during particular years, the depth of the ozone losses in the Arctic are considerably smaller, and their occurrence is far less frequent. Many Antarctic total integrated column ozone observations in spring since approximately the 1980s show values considerably below those ever observed in earlier decades. For the Arctic, there is evidence of some spring season depletion of total ozone at particular stations, but the changes are much less pronounced compared with the range of past data. Thus, the observations demonstrate that the widespread and deep ozone depletion that characterizes the Antarctic ozone hole is a unique feature on the planet.

  12. Global Warming: Lessons from Ozone Depletion

    Science.gov (United States)

    Hobson, Art

    2010-01-01

    My teaching and textbook have always covered many physics-related social issues, including stratospheric ozone depletion and global warming. The ozone saga is an inspiring good-news story that's instructive for solving the similar but bigger problem of global warming. Thus, as soon as students in my physics literacy course at the University of…

  13. Global Warming: Lessons from Ozone Depletion

    Science.gov (United States)

    Hobson, Art

    2010-01-01

    My teaching and textbook have always covered many physics-related social issues, including stratospheric ozone depletion and global warming. The ozone saga is an inspiring good-news story that's instructive for solving the similar but bigger problem of global warming. Thus, as soon as students in my physics literacy course at the University of…

  14. “When the going gets tough, who keeps going?” Depletion sensitivity moderates the ego-depletion effect

    Science.gov (United States)

    Salmon, Stefanie J.; Adriaanse, Marieke A.; De Vet, Emely; Fennis, Bob M.; De Ridder, Denise T. D.

    2014-01-01

    Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In three studies, we assessed individual differences in depletion sensitivity, and demonstrate that depletion sensitivity moderates ego-depletion effects. The Depletion Sensitivity Scale (DSS) was employed to assess depletion sensitivity. Study 1 employs the DSS to demonstrate that individual differences in sensitivity to ego-depletion exist. Study 2 shows moderate correlations of depletion sensitivity with related self-control concepts, indicating that these scales measure conceptually distinct constructs. Study 3 demonstrates that depletion sensitivity moderates the ego-depletion effect. Specifically, participants who are sensitive to depletion performed worse on a second self-control task, indicating a stronger ego-depletion effect, compared to participants less sensitive to depletion. PMID:25009523

  15. “When the going gets tough, who keeps going?” Depletion sensitivity moderates the ego-depletion effect

    NARCIS (Netherlands)

    Salmon, S.J.; Adriaanse, M.A.; Vet, de E.W.M.L.; Fennis, B.M.; Ridder, de D.T.D.

    2014-01-01

    Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In thre

  16. Human Health Effects of Ozone Depletion From Stratospheric Aircraft

    Science.gov (United States)

    Wey, Chowen (Technical Monitor)

    2001-01-01

    This report presents EPA's initial response to NASA's request to advise on potential environmental policy issues associated with the future development of supersonic flight technologies. Consistent with the scope of the study to which NASA and EPA agreed, EPA has evaluated only the environmental concerns related to the stratospheric ozone impacts of a hypothetical HSCT fleet, although recent research indicates that a fleet of HSCT is predicted to contribute to climate warming as well. This report also briefly describes the international and domestic institutional frameworks established to address stratospheric ozone depletion, as well as those established to control pollution from aircraft engine exhaust emissions.

  17. How Depleted is the MORB mantle?

    Science.gov (United States)

    Hofmann, A. W.; Hart, S. R.

    2015-12-01

    Knowledge of the degree of mantle depletion of highly incompatible elements is critically important for assessing Earth's internal heat production and Urey number. Current views of the degree of MORB source depletion are dominated by Salters and Stracke (2004), and Workman and Hart (2005). The first is based on an assessment of average MORB compositions, whereas the second considers trace element data of oceanic peridotites. Both require an independent determination of one absolute concentration, Lu (Salters & Stracke), or Nd (Workman & Hart). Both use parent-daughter ratios Lu/Hf, Sm/Nd, and Rb/Sr calculated from MORB isotopes combined with continental-crust extraction models, as well as "canonical" trace element ratios, to boot-strap the full range of trace element abundances. We show that the single most important factor in determining the ultimate degree of incompatible element depletion in the MORB source lies in the assumptions about the timing of continent extraction, exemplified by continuous extraction versus simple two-stage models. Continued crust extraction generates additional, recent mantle depletion, without affecting the isotopic composition of the residual mantle significantly. Previous emphasis on chemical compositions of MORB and/or peridotites has tended to obscure this. We will explore the effect of different continent extraction models on the degree of U, Th, and K depletion in the MORB source. Given the uncertainties of the two most popular models, the uncertainties of U and Th in DMM are at least ±50%, and this impacts the constraints on the terrestrial Urey ratio. Salters, F.J.M. and Stracke, A., 2004, Geochem. Geophys. Geosyst. 5, Q05004. Workman, R.K. and Hart, S.R., 2005, EPSL 231, 53-72.

  18. Depletion calculations for the McClellan Nuclear Radiation Center.

    Energy Technology Data Exchange (ETDEWEB)

    Klann, R. T.; Newell, D. L.

    1997-12-08

    Depletion calculations have been performed for the McClellan reactor history from January 1990 through August 1996. A database has been generated for continuing use by operations personnel which contains the isotopic inventory for all fuel elements and fuel-followed control rods maintained at McClellan. The calculations are based on the three-dimensional diffusion theory code REBUS-3 which is available through the Radiation Safety Information Computational Center (RSICC). Burnup-dependent cross-sections were developed at zero power temperatures and full power temperatures using the WIMS code (also available through RSICC). WIMS is based on discretized transport theory to calculate the neutron flux as a function of energy and position in a one-dimensional cell. Based on the initial depletion calculations, a method was developed to allow operations personnel to perform depletion calculations and update the database with a minimal amount of effort. Depletion estimates and calculations can be performed by simply entering the core loading configuration, the position of the control rods at the start and end of cycle, the reactor power level, the duration of the reactor cycle, and the time since the last reactor cycle. The depletion and buildup of isotopes of interest (heavy metal isotopes, erbium isotopes, and fission product poisons) are calculated for all fuel elements and fuel-followed control rods in the MNRC inventory. The reactivity loss from burnup and buildup of fission product poisons and the peak xenon buildup after shutdown are also calculated. The reactivity loss from going from cold zero power to hot full power can also be calculated by using the temperature-dependent, burnup-dependent cross-sections. By calculating all of these reactivity effects, operations personnel are able to estimate the total excess reactivity necessary to run the reactor for the given cycle. This method has also been used to estimate the worth of individual control rods. Using this

  19. Early Paleogene dinoflagellate cysts from ODP Hole 959D, Côte d'Ivoire-Ghana Transform Margin, West Africa: New species, biostratigraphy and paleoenvironmental implications

    Science.gov (United States)

    Awad, Walaa K.; Oboh-Ikuenobe, Francisca E.

    2016-11-01

    A nearly continuous sedimentary record from Ocean Drilling Program (ODP) Site 959 (Hole 959D) in the Côte d'Ivoire-Ghana Transform Margin provides the opportunity to study Lower Paleogene palynology in this equatorial region. This paper presents data for 117 dinoflagellate cyst taxa recorded in 18 samples covering a 91-m interval from 867.60 mbsf to 776.32 mbsf. Preservation of dinoflagellate cysts varied from poor to excellent, and recovery was almost superabundant. Based on last or first occurrence of dinoflagellate cyst events, five zones (zone 1 to zone 5) were identified. The concentration of several dinoflagellate cyst events in the Thanetian interval suggests the presence of hiatuses or condensed horizons as inferred in previous studies of nearby localities. Frequent to common abundance of Apectodinium in the upper Thanetian sediments apparently records the global episodes of intense climatic warming that characterized the latest Paleocene to earliest Eocene time. An assemblage dominated by species of Operculodinium, Spiniferites, and Tectatodinium confirms the outer neritic to oceanic depositional setting of the drill hole as previously inferred from lithologic characteristics. Finally, four new dinoflagellate cyst taxa, Adnatosphaeridium ivoriense, Diphyes digitum, Eocladopyxis furculum and Tectatodinium nigeriaense that were observed only in the Paleocene interval, have been formally identified and described in detail.

  20. Tectonic analysis and paleo-stress determination of the upper lava section at ODP/IODP site 1256 (East Pacific Ocean)

    Science.gov (United States)

    Fontana, Emanuele

    2015-09-01

    Research on the deep sea is of great importance for a better understanding of the mechanism of magma emplacement and the tectonic evolution of oceanic crust. However, details of the internal structure in the upper levels of the oceanic crust are much less complete than that of the more fully studied sub-aerial areas. For the first time, this study proposes a dynamic analysis using the inversion method on core data derived from the drilled basement of the present-day intact oceanic crust at ODP/IODP Site 1256 in the Cocos plate. The research is based on an innovative core reorientation process and combines different stress hypothesis approaches for the analysis of heterogeneous failure-slip data via exploitation of two distinct techniques. From the analysis of the failure-slip data, both techniques produce 5 distinct subsystem datasets. All calculated subsystems are mechanically and geometrically admissible. Interpretation of the results allows the researchers to note a complex local and regional tectonic evolution deriving from the interplay of (1) the ridge push and rotation of both the East Pacific Rise and the Cocos-Nazca Spreading Center, (2) the effect of the slab pull of the Middle America Trench, (3) the influence of lava emplacement mechanisms, and (4) intra-plate deformation.

  1. Late Quaternary Vegetation and Climate Change in the Amazon Basin Based on a 50,000 Year Pollen Record from the Amazon Fan, ODP Site 932

    Science.gov (United States)

    Haberle, Simon G.; Maslin, Mark A.

    1999-01-01

    Hemipelagic sediments from the Amazon deep-sea fan, ODP Site 932 (5° 12.7‧N, 47° 1.8‧W), and continental shelf provide a 50,000-yr-long pollen record of Amazon Basin vegetation. The age model for Hole 932A is constrained by eight magnetic remanence intensity features, one paleomagnetic excursion, and three AMS14C dates.Alchornea,Melastomataceae, Myrtaceae, and Moraceae/Urticaceae are dominant taxa in the pollen record between 40,200 and 19,800 cal yr B.P. Andean taxa, such asPodocarpusandHedyosmum,increase in abundance between 19,800 and 11,000 cal yr B.P. and prior to 40,200 cal yr B.P. The Holocene pollen assemblage, derived from Amazon River and continental shelf sediments, is dominated by secondary growth taxa, such asCecropia.Climatic factors influencing the development of glacial and interglacial tropical vegetation are considered by comparing marine with terrestrial records of vegetation change. This comparison shows that the Amazon Basin forests were not extensively replaced by savanna vegetation during the glacial period, contradicting the refugia hypothesis.

  2. Quaternary clay mineralogy in the northern South China Sea (ODP Site 1146)--Implications for oceanic current transport and East Asian monsoon evolution

    Institute of Scientific and Technical Information of China (English)

    LIU Zhifei(刘志飞); Alain Trentesaux; Steven C. Clemens; WANG Pinxian(汪品先)

    2003-01-01

    Measurement of clay mineralogy at ODP Site 1146 in the northern South China Sea (SCS) indicates that illite, chlorite, and kaolinite contents increased during glacials and smectite content increased during interglacials. The smectite/(illite+chlorite) ratio and the smectite abundance were determined as mineralogical indicators for the East Asian monsoon evolution. At a 10 ka timescale, prevailing southeasterly surface oceanic currents during interglacials transported more smectite from the south and east areas to the north, showing a strengthened summer monsoon circulation, whereas dominated counter-clockwise surface currents during glacials carried more illite and chlorite from Taiwan as well as from the Yangtze River via the Luzon Strait to the northern SCS, indicating a strongly intensified winter monsoon. Based on a 100 ka timescale, a linear correlation between the smectite/(illite+chlorite) ratio and the sedimentation rate reflects that the winter monsoon has prevailed in the northern SCS in the intervals 2000-1200 ka and 400-0 ka and the summer monsoon did the same in the interval 1200-400 ka. The evolution of the summer monsoon provides an almost linear response to the summer insolation of Northern Hemisphere, implying an astronomical forcing of the East Asian monsoon evolution.

  3. Late Paleocene-middle Eocene benthic foraminifera on a Pacific seamount (Allison Guyot, ODP Site 865): Greenhouse climate and superimposed hyperthermal events

    Science.gov (United States)

    Arreguín-Rodríguez, Gabriela J.; Alegret, Laia; Thomas, Ellen

    2016-03-01

    We investigated the response of late Paleocene-middle Eocene (~60-37.5 Ma) benthic foraminiferal assemblages to long-term climate change and hyperthermal events including the Paleocene-Eocene Thermal Maximum (PETM) at Ocean Drilling Program (ODP) Site 865 on Allison Guyot, a seamount in the Mid-Pacific Mountains. Seamounts are isolated deep-sea environments where enhanced current systems interrupt bentho-pelagic coupling, and fossil assemblages from such settings have been little evaluated. Assemblages at Site 865 are diverse and dominated by cylindrical calcareous taxa with complex apertures, an extinct group which probably lived infaunally. Dominance of an infaunal morphogroup is unexpected in a highly oligotrophic setting, but these forms may have been shallow infaunal suspension feeders, which were ecologically successful on the current-swept seamount. The magnitude of the PETM extinction at Site 865 was similar to other sites globally, but lower diversity postextinction faunas at this location were affected by ocean acidification as well as changes in current regime, which might have led to increased nutrient supply through trophic focusing. A minor hyperthermal saw less severe effects of changes in current regime, with no evidence for carbonate dissolution. Although the relative abundance of infaunal benthic foraminifera has been used as a proxy for surface productivity through bentho-pelagic coupling, we argue that this proxy can be used only in the absence of changes in carbonate saturation and current-driven biophysical linking.

  4. Palynological record during the Pleistocene (between 1.05 Ma and 0.36 Ma) from ODP1144, northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    HUANG; Fei; SUN; Xiangjun

    2004-01-01

    This paper presents the pollen record from the lower section of ODP1144 (depth 501.3-225.7 m, ca. 1.05-0.36 Ma). Two pollen zones (PA and PB) and eleven pollen subzones are recognized. Within zone PB, the 11 pollen subzones (PB21-11) are defined according to the pine, fern and herb variations, and are equivalent to the marine isotope stages 21-11 (MISs 21-11). The interglacial periods are typified by an increase in pine pollen and fern spores, and a decrease in herbaceous pollen, while the patterning during the glacial periods is just the opposite. During the interglacial periods, pollen assemblages were dominated by pine similar to those of the present day, suggesting that the paleoenvironment of the interglacial periods was similar to that of the present day, whereas the glacial periods are marked by an increase in herbaceous pollen, mainly Gramineae and Cyperaceae, indicating that grassland covered the exposed continental shelf when sea level declined. Increased Artemisia percentages and the highest pine influx during MIS12 may result from a stronger winter monsoon.

  5. Neutron-activation revisited: the depletion and depletion-activation models.

    Science.gov (United States)

    Abdel-Rahman, Wamied; Podgorsak, Ervin B

    2005-02-01

    The growth of a radioactive daughter in neutron activation is commonly described with the saturation model that ignores the consumption of parent nuclei during the radio-activation process. This approach is not valid when radioactive sources with high specific activities are produced or when the particle fluence rates used are very high. Assuming a constant neutron fluence rate throughout the activation target, a neutron-activation model that accounts for the depletion in parent nuclei is introduced. This depletion model is governed by relationships similar to those describing the parent-daughter-granddaughter decay series, and, in contrast to the saturation model, correctly predicts the practical limit of the daughter specific activity, irrespective of the particle fluence rate. Also introduced is a neutron-activation model that in addition to parent depletion accounts for the neutron activation of daughter nuclei in situations where the cross section for this effect is high. The model is referred to as the depletion-activation model and it provides the most realistic description for the daughter specific activity in neutron activation. Three specific neutron activation examples of interest to medical physics are presented: activation of molybdenum-98 into molybdenum-99 described by the saturation model; activation of cobalt-59 into cobalt-60 described by the depletion model; and activation of iridium-191 into iridium-192 described by the depletion-activation model.

  6. Organic chemistry of fluids from sediment-buried young basement: discrete sampling from ODP borehole 1301A & 1025C

    Science.gov (United States)

    Lin, H.; Cowen, J. P.; Amend, J. P.; Albert, D. B.; Glazer, B. T.; Rappe, M.; Jungbluth, S.; Matzinger, M.

    2010-12-01

    Hydrothermal systems profoundly influence seawater chemistry. However, the extent to which hydrothermal systems impact the quantity and the quality of the deep ocean dissolved organic carbon (DOC) pool remains unclear. To study the organic chemistry within sedimented ridge flank basement aquifers, discrete low temperature (~65°C & ~40°C) basement fluids were collected from Integrated Ocean Drilling Program boreholes via Circulation Obviation Retrofit Kit (CORK) observatories at 1301A (47°45N, 127°45W) and 1025C (47°53N, 128°39W) on the eastern flank of Juan de Fuca Ridge. The basement age is 1.24 Ma and 3.5 Ma at 1025C and 1301A, respectively. Basement fluids were collected using a new clean pumping system (Mobile Pump Valve Unit, or MPVU) and stored in acid-cleaned 60 L Large Volume Tedlar Bags (LVBS). A stainless steel fluid delivery line extends from the basement to the seafloor at 1301A; whereas fluids rise up the middle of the iron casing at 1025C. Here, concentration and preliminary characterization of the DOC will be presented, including labile organic components such as dissolved free and combined amino acids (DFAA & DCAA) and low molecular weight organic acids (LMW-OA). Our data show that compared to seawater levels, the DOC concentration in the younger basement fluid (1025C) was about one-half and in the older (1031A) was less than one-third. Relative to bottom seawater, the basement fluids are also depleted in SO42-, PO43-, NO3- and NO2-, but enriched in NH4+, H2S, Mn and Fe. Microbially mediated reduction of nitrate, sulfate, iron, and manganese and an array of heterotrophic metabolisms may explain these observations. Phylogenic trees based on 16S rRNA gene sequences from borehole 1301A fluids further support the presence of chemolithoautotrophic and heterotrophic organisms. Our preliminary results show that some dissolved free amino acids were slightly enriched in the 1301A basement fluid relative to bottom seawater. Thermodynamic calculations

  7. Geochemical fluxes related to alteration of a subaerially exposed seamount: Nintoku seamount, ODP Leg 197, Site 1205

    Science.gov (United States)

    RéVillon, Sidonie; Teagle, Damon A. H.; Boulvais, Philippe; Shafer, John; Neal, Clive R.

    2007-02-01

    Hole 1205A was drilled on Nintoku Seamount, which lies in the midportion of the Emperor Seamount Chain. This seamount was emergent ˜56 Myr ago but was submerged by 54 Ma, so the lavas have endured weathering in both subaerial and submarine environments. We have studied the petrology, mineralogy, and geochemistry of intercalated altered basalts, breccias, and soil samples recovered at Hole 1205A to quantify the chemical exchanges between the seamount and seawater and/or meteoric fluids. The secondary mineralogy is relatively uniform throughout the section and comprises smectite, Fe-oxyhydroxides, iddingsite, and Ca-carbonates. Soils are composed of variably altered basaltic clasts in a matrix of kaolinite, smectite, and vermiculite with minor goethite, hematite, and magnetite. Throughout the basement section, altered basalts, breccias, and soils are depleted in Si, Mg, Ca, Na, Sr, Rb, and Ba and enriched in Fe. Fe3+/FeT (up to ˜1), δ18O (up to ˜+20‰), and 87Sr/86Sr ratios are strongly elevated relative to primary igneous values. Differences in the 87Sr/86Sr ratios define an Upper Alteration Zone with 87Sr/86Sr close to 56 Ma seawater (˜0.7077) from a Lower Alteration Zone where 87Sr/86Sr are less elevated (˜0.704). The Lower Alteration Zone likely reflects interaction with a subaerial oxidizing fluid at low temperature. This zone probably retained most of the original subaerial weathering signature. The Upper Alteration Zone was altered through circulation of large quantities of cold oxidizing seawater that partially overprinted the subaerial weathering chemical characteristics. Altered samples were compared to estimated protolith compositions to calculate chemical gains and losses. Global chemical fluxes are calculated for the entire basement section using different lithological proportions models and different rates of oceanic island emplacement. Although the global construction rate of ocean islands is small compared to igneous accretion at mid

  8. Ecological and corrosion behavior of depleted uranium

    Directory of Open Access Journals (Sweden)

    Stojanović Mirjana D.

    2015-01-01

    Full Text Available Environmental pollution with radionuclides, particularly uranium and its decay products is a serious global problem. The current scientific studies estimated that the contamination originating from TENORM, caused by nuclear and non-nuclear technologies, has significantly increased natural level of radioactivity in the last thirty years. During the last decades all the more were talking about the "new pollutant" - depleted uranium (DU, which has been used in anti-tank penetrators because of its high density, penetration and pyrophoric properties. It is estimated that during the Gulf War, the war in Bosnia and Yugoslavia and during the invasion of Iraq, 1.4 million missiles with depleted uranium was fired. During the NATO aggression against the ex Yugoslavia in 1999., 112 locations in Kosovo and Metohija, 12 locations in southern Serbia and two locations in Montenegro were bombed. On this occasion, approximately 10 tons of depleted uranium were entered into the environment, mainly on land, where the degree of contamination ranged from 200 Bq / kg to 235 000 Bq/kg, which is up to 1000 times higher than the natural level. Fourteen years ago there was very little information about the behavior of ecological systems damaged by DU penetrators fired. Today, unfortunately, we are increasingly faced with the ―invisible threat" of depleted uranium, which has a strong radioactive and hemotoxic impact on human health. Present paper provides a detailed overview of the current understanding of corrosion and corrosion behavior of DU and environmental factors that control corrosion, together with indicators of environmental impact in order to highlight areas that need further attention in developing remediation programs.

  9. The ultimate disposition of depleted uranium

    Energy Technology Data Exchange (ETDEWEB)

    Lemons, T.R. [Uranium Enrichment Organization, Oak Ridge, TN (United States)

    1991-12-31

    Depleted uranium (DU) is produced as a by-product of the uranium enrichment process. Over 340,000 MTU of DU in the form of UF{sub 6} have been accumulated at the US government gaseous diffusion plants and the stockpile continues to grow. An overview of issues and objectives associated with the inventory management and the ultimate disposition of this material is presented.

  10. Barium depletion in hollow cathode emitters

    Energy Technology Data Exchange (ETDEWEB)

    Polk, James E., E-mail: james.e.polk@jpl.nasa.gov; Mikellides, Ioannis G.; Katz, Ira [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States); Capece, Angela M. [Graduate Aerospace Laboratories, California Institute of Technology, Pasadena, California 91125 (United States)

    2016-01-14

    Dispenser hollow cathodes rely on a consumable supply of Ba released by BaO-CaO-Al{sub 2}O{sub 3} source material in the pores of a tungsten matrix to maintain a low work function surface. The examination of cathode emitters from long duration tests shows deposits of tungsten at the downstream end that appear to block the flow of Ba from the interior. In addition, a numerical model of Ba transport in the cathode plasma indicates that the Ba partial pressure in the insert may exceed the equilibrium vapor pressure of the dominant Ba-producing reaction, and it was postulated previously that this would suppress Ba loss in the upstream part of the emitter. New measurements of the Ba depletion depth from a cathode insert operated for 8200 h reveal that Ba loss is confined to a narrow region near the downstream end, confirming this hypothesis. The Ba transport model was modified to predict the depletion depth with time. A comparison of the calculated and measured depletion depths gives excellent qualitative agreement, and quantitative agreement was obtained assuming an insert temperature 70 °C lower than measured beginning-of-life values.

  11. Mitochondrial DNA depletion analysis by pseudogene ratioing.

    Science.gov (United States)

    Swerdlow, Russell H; Redpath, Gerard T; Binder, Daniel R; Davis, John N; VandenBerg, Scott R

    2006-01-30

    The mitochondrial DNA (mtDNA) depletion status of rho(0) cell lines is typically assessed by hybridization or polymerase chain reaction (PCR) experiments, in which the failure to hybridize mtDNA or amplify mtDNA using mtDNA-directed primers suggests thorough mitochondrial genome removal. Here, we report the use of an mtDNA pseudogene ratioing technique for the additional confirmation of rho0 status. Total genomic DNA from a U251 human glioma cell line treated with ethidium bromide was amplified using primers designed to anneal either mtDNA or a previously described nuclear DNA-embedded mtDNA pseudogene (mtDNApsi). The resultant PCR product was used to generate plasmid clones. Sixty-two plasmid clones were genotyped, and all arose from mtDNApsi template. These data allowed us to determine with 95% confidence that the resultant mtDNA-depleted cell line contains less than one copy of mtDNA per 10 cells. Unlike previous hybridization or PCR-based analyses of mtDNA depletion, this mtDNApsi ratioing technique does not rely on interpretation of a negative result, and may prove useful as an adjunct for the determination of rho0 status or mtDNA copy number.

  12. Residue depletion of albendazole and its metabolites in aquacultured yellow perch (Perca flavescens).

    Science.gov (United States)

    Yu, D; Evans, E R; Hasbrouck, N; Reimschuessel, R; Shaikh, B

    2012-12-01

    Metabolism and residue depletion studies are conducted to determine the marker residue (MR) of a drug in a target tissue of food animals. The MR is used to monitor potential unauthorized use of drugs. The current work is a continuation of our efforts to study metabolism and depletion profiles of albendazole in multiple finfish species to determine a common MR. The results of this study suggest that albendazole sulfone metabolite could potentially serve as MR for albendazole in yellow perch muscle, similar to channel catfish and hybrid striped bass as reported previously by us.

  13. Selection of a management strategy for depleted uranium hexafluoride

    Energy Technology Data Exchange (ETDEWEB)

    Patton, S.E.; Hanrahan, E.J.; Bradley, C.E.

    1995-09-06

    A consequence of the uranium enrichment process used in the United States (US) is the accumulation of a significant amount of depleted uranium hexafluoride (UF{sub 6}). Currently, approximately 560,000 metric tons of the material are stored at three different sites. The US Department of Energy (DOE) has recently initiated a program to consider alternative strategies for the cost-effective and environmentally safe long-term management of this inventory of depleted UF{sub 6}. The program involves a technology and engineering assessment of proposed management options (use/reuse, conversion, storage, or disposal) and an analysis of the potential environmental impacts and life-cycle costs of alternative management strategies. The information obtained from the studies will be used by the DOE to select a preferred long-term management strategy. The selection and implementation of a management strategy will involve consideration of a number of important issues such as environmental, health, and safety effects; the balancing of risks versus costs in a context of reduced government spending; socioeconomic implications, including effects on the domestic and international uranium industry; the technical status of proposed uses or technologies; and public involvement in the decision making process. Because of its provisions for considering a wide range of relevant issues and involving the public, this program has become a model for future DOE materials disposition programs. This paper presents an overview of the Depleted Uranium Hexafluoride Management Program. Technical findings of the program to date are presented, and major issues involved in selecting and implementing a management strategy are discussed.

  14. Stratospheric ozone depletion from future nitrous oxide increases

    Directory of Open Access Journals (Sweden)

    W. Wang

    2014-12-01

    Full Text Available We have investigated the impact of the assumed nitrous oxide (N2O increases on stratospheric chemistry and dynamics using a series of idealized simulations with a coupled chemistry-climate model (CCM. In a future cooler stratosphere the net yield of NOy from N2O is shown to decrease in a reference run following the IPCC A1B scenario, but NOy can still be significantly increased by extra increases of N2O over 2001–2050. Over the last decade of simulations, 50% increases in N2O result in a maximal 6% reduction in ozone mixing ratios in the middle stratosphere at around 10 hPa and an average 2% decrease in the total ozone column (TCO compared with the control run. This enhanced destruction could cause an ozone decline in the first half of this century in the middle stratosphere around 10 hPa, while global TCO still shows an increase at the same time. The results from a multiple linear regression analysis and sensitivity simulations with different forcings show that the chemical effect of N2O increases dominates the N2O-induced ozone depletion in the stratosphere, while the dynamical and radiative effects of N2O increases are overall insignificant. The analysis of the results reveals that the ozone depleting potential of N2O varies with the time period and is influenced by the environmental conditions. For example, carbon dioxide (CO2 increases can strongly offset the ozone depletion effect of N2O.

  15. Lithium Depletion in Fully Convective Pre-Main Sequence Stars

    CERN Document Server

    Bildsten, L; Matzner, C D; Ushomirsky, G; Bildsten, Lars; Brown, Edward F.; Matzner, Christopher D.; Ushomirsky, Greg

    1996-01-01

    We present an analytic calculation of the thermonuclear depletion of lithium in contracting, fully convective, pre-main sequence stars of mass M 0.08 M_sun) and for constraining the masses of lithium depleted stars.

  16. (JASR) Vol. 12, No. 2, 2012 DEPLETING FOREST RESOURCES OF ...

    African Journals Online (AJOL)

    HP

    undisturbed lands leading to depletion of the forest cover and increase on the sand dunes .... depletion of the ozone layer leading to a rise in global temperature. ... Nigeria has good correlation with greenhouse gas emission which can cause ...

  17. Depletions at Browns Park National Wildlife Refuge [Draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Estimated depletion associated with the operation of Spitzie Marsh in Browns Park National Wildlife Refuge. Attached are the methods used to estimate depletion....

  18. Self-regulatory depletion increases emotional reactivity in the amygdala

    National Research Council Canada - National Science Library

    Wagner, Dylan D; Heatherton, Todd F

    2013-01-01

    ... attention control task that required effortful inhibition (depletion group) or not (control group). Compared to the control group, depleted participants showed increased activity in the left amygdala to negative but not to positive or neutral scenes...

  19. Effects of Opuntia dillenii Haw.Polysaccharide Component (ODP-Ⅰa) on Erythrocyte lipid Peroxidative Injury in vivo%仙人掌多糖主要组分对大鼠红细胞脂质过氧化损伤的影响

    Institute of Scientific and Technical Information of China (English)

    赵龙岩; 兰琦杰; 曾富华; 饶力群

    2011-01-01

    目的 分离纯化仙人掌多糖主要组分,观察仙人掌多糖主要组分(ODP-Ⅰ a)对红细胞脂质过氧化损伤的影响,探讨其抗氧化机制.方法 从野生仙人掌Opuntia dillenii Haw.中采用超声提取法并用DEAE-Sepharose Fast Flow柱层析纯化得到仙人掌多糖组分ODP-Ⅰ a、ODP-Ⅰ b和ODP-Ⅱ'.以活性氧(HO)作用于离体正常大鼠红细胞,观察ODP-Ⅰa对红细胞溶血率、高铁血红蛋白含量、丙二醛含量、超氧化物歧化酶和谷胱甘肽过氧化物酶活性、红细胞膜蛋白巯基含量和膜蛋白质高分子聚合物的影响.结果 ODP-Ⅰ a能够抑制HO诱导的红细胞溶血和高铁血红蛋白的产生;提高HO氧化损伤红细胞中超氧化物歧化酶活性、谷胱甘肽过氧化物酶活性和降低丙二醛含量;同时,能够抑制HO引起的膜蛋白巯基含量的降低和红细胞膜蛋白高分子聚合物的形成.结论 ODP-Ⅰ a对活性氧引起的红细胞脂质过氧化损伤具有保护作用.

  20. Children's Models of the Ozone Layer and Ozone Depletion.

    Science.gov (United States)

    Christidou, Vasilia; Koulaidis, Vasilis

    1996-01-01

    The views of 40 primary students on ozone and its depletion were recorded through individual, semi-structured interviews. The data analysis resulted in the formation of a limited number of models concerning the distribution and role of ozone in the atmosphere, the depletion process, and the consequences of ozone depletion. Identifies five target…

  1. Children's Models of the Ozone Layer and Ozone Depletion.

    Science.gov (United States)

    Christidou, Vasilia; Koulaidis, Vasilis

    1996-01-01

    The views of 40 primary students on ozone and its depletion were recorded through individual, semi-structured interviews. The data analysis resulted in the formation of a limited number of models concerning the distribution and role of ozone in the atmosphere, the depletion process, and the consequences of ozone depletion. Identifies five target…

  2. 26 CFR 1.642(e)-1 - Depreciation and depletion.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Depreciation and depletion. 1.642(e)-1 Section 1... (CONTINUED) INCOME TAXES Estates, Trusts, and Beneficiaries § 1.642(e)-1 Depreciation and depletion. An estate or trust is allowed the deductions for depreciation and depletion, but only to the extent...

  3. Indirect Measurement of Evapotranspiration from Soil Moisture Depletion

    Science.gov (United States)

    Li, M.; Chen, Y.

    2007-12-01

    Direct and in situ measurement of evapotranspiration (ET), such as the eddy covariance (EC) method, is often expensive and complicated, especially over tall canopy. In view of soil water balance, depletion of soil moisture can be attributed to canopy ET when horizontal soil moisture movement is negligible and percolation ceases. This study computed the daily soil moisture depletion at the Lien-Hua-Chih (LHC) station (23°55'52"N, 120°53'39"E, 773 m elevation) from July, 2004 to June, 2007 to estimate daily ET. The station is inside an experimental watershed of a natural evergreen forest and the canopy height is about 17 m. Rainfall days are assumed to be no ET. For those days with high soil moisture content, normally 2 to 3 days after significant rainfall input, ET is estimated by potential ET. Soil moistures were measured by capacitance probes at -10 cm, - 30 cm, -50 cm, -70 cm, and -90 cm. A soil heat flux plate was placed at -5 cm. In the summer of 2006, a 22 m tall observation tower was constructed. Temperature and relative humidity sensors were placed every 5 m from ground surface to 20 m for inner and above canopy measurements. Net radiation and wind speed/directions were also installed. A drainage gauge was installed at -50 cm to collect infiltrated water. Continuous measurements of low response instruments were recorded every 30-minute averaged from 10-minute samplings. A nearby weather station provides daily pan evaporation and precipitation data. Since the response of soil water variations is relatively slow to the fluctuations of atmospheric forcing, only daily ET is estimated from daily soil moisture depletion. The annual average precipitation is 2902 mm and the annual average ET is 700 mm. The seasonal ET patterns of the first two water years are similar. The third year has a higher ET because soil moisture was recharged frequently by rainfall In order to examine the applicability of this approach, an EC system, including a 3-D sonic anemometer (Young

  4. Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, Alaska

    Directory of Open Access Journals (Sweden)

    C. R. Thompson

    2014-11-01

    Full Text Available The springtime depletion of tropospheric ozone in the Arctic is known to be caused by active halogen photochemistry resulting from halogen atom precursors emitted from snow, ice, or aerosol surfaces. The role of bromine in driving ozone depletion events (ODEs has been generally accepted, but much less is known about the role of chlorine radicals in ozone depletion chemistry. While the potential impact of iodine in the High Arctic is more uncertain, there have been indications of active iodine chemistry through observed enhancements in filterable iodide, probable detection of tropospheric IO, and recently, detection of atmospheric I2. Despite decades of research, significant uncertainty remains regarding the chemical mechanisms associated with the bromine-catalyzed depletion of ozone, as well as the complex interactions that occur in the polar boundary layer due to halogen chemistry. To investigate this, we developed a zero-dimensional photochemical model, constrained with measurements from the 2009 OASIS field campaign in Barrow, Alaska. We simulated a 7 day period during late March that included a full ozone depletion event lasting 3 days and subsequent ozone recovery to study the interactions of halogen radicals under these different conditions. In addition, the effects of iodine added to our base model were investigated. While bromine atoms were primarily responsible for ODEs, chlorine and iodine were found to enhance the depletion rates and iodine was found to be more efficient per atom at depleting ozone than Br. The interaction between chlorine and bromine is complex, as the presence of chlorine can increase the recycling and production of Br atoms, while also increasing reactive bromine sinks under certain conditions. Chlorine chemistry was also found to have significant impacts on both HO2 and RO2. The results of this work highlight the need for future studies on the production mechanisms of Br2 and Cl2, as well as on the potential

  5. A modern depleted uranium manufacturing facility

    Energy Technology Data Exchange (ETDEWEB)

    Zagula, T.A.

    1995-07-01

    The Specific Manufacturing Capabilities (SMC) Project located at the Idaho National Engineering Laboratory (INEL) and operated by Lockheed Martin Idaho Technologies Co. (LMIT) for the Department of Energy (DOE) manufactures depleted uranium for use in the U.S. Army MIA2 Abrams Heavy Tank Armor Program. Since 1986, SMC has fabricated more than 12 million pounds of depleted uranium (DU) products in a multitude of shapes and sizes with varying metallurgical properties while maintaining security, environmental, health and safety requirements. During initial facility design in the early 1980`s, emphasis on employee safety, radiation control and environmental consciousness was gaining momentum throughout the DOE complex. This fact coupled with security and production requirements forced design efforts to focus on incorporating automation, local containment and computerized material accountability at all work stations. The result was a fully automated production facility engineered to manufacture DU armor packages with virtually no human contact while maintaining security, traceability and quality requirements. This hands off approach to handling depleted uranium resulted in minimal radiation exposures and employee injuries. Construction of the manufacturing facility was complete in early 1986 with the first armor package certified in October 1986. Rolling facility construction was completed in 1987 with the first certified plate produced in the fall of 1988. Since 1988 the rolling and manufacturing facilities have delivered more than 2600 armor packages on schedule with 100% final product quality acceptance. During this period there was an annual average of only 2.2 lost time incidents and a single individual maximum radiation exposure of 150 mrem. SMC is an example of designing and operating a facility that meets regulatory requirements with respect to national security, radiation control and personnel safety while achieving production schedules and product quality.

  6. Conversion of Fibroblasts to Neural Cells by p53 Depletion

    Directory of Open Access Journals (Sweden)

    Di Zhou

    2014-12-01

    Full Text Available Conversion from fibroblasts to neurons has recently been successfully induced. However, the underlying mechanisms are poorly understood. Here, we find that depletion of p53 alone converts fibroblasts into all three major neural lineages. The induced neuronal cells express multiple neuron-specific proteins and generate action potentials and transmitter-receptor-mediated currents. Surprisingly, depletion does not affect the well-known tumorigenic p53 target, p21. Instead, knockdown of p53 upregulates neurogenic transcription factors, which in turn boosts fibroblast-neuron conversion. p53 binds the promoter of the neurogenic transcription factor Neurod2 and regulates its expression during fibroblast-neuron conversion. Furthermore, our method provides a high efficiency of conversion in late-passage fibroblasts. Genome-wide transcriptional analysis shows that the p53-deficiency-induced neurons exhibit an expression profile different from parental fibroblasts and similar to control-induced neurons. The results may help to understand and improve neural conversion mechanisms to develop robust neuron-replacement therapy strategies.

  7. SUZ12 Depletion Suppresses the Proliferation of Gastric Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yingjun Cui

    2013-05-01

    Full Text Available Background/Aims: SUZ12 and EZH2 are two main components of polycomb repressive complex 2 (PRC2 that is known to be of great importance in tumorigenesis. EZH2 has been reported to play a vital role in pathogenesis of human cancer. However, whether SUZ12 has equivalent roles in tumorigenesis has not been demonstrated. Here, we investigated a possible role of SUZ12 for the proliferation of gastric cancer cells. Methods: Western-blot analysis was used to detected the levels of SUZ12, H3K27me3, EZH2 and p27 in ten gastric cell lines. SUZ12 was depleted by RNA interference. Cell cycle was detected by flow cytometry. Luciferase assays was to analyze whether miR-200b directly regulate SUZ12. Results: We found that SUZ12 depletion mediated by RNA interference (RNAi led to a reduction of gastric cell numbers and arrested the cell cycle at G1/S point. As an important G1/S phase inhibitory gene, p27 is re-induced to some extent by SUZ12 knockdown. Furthermore, we demonstrated that SUZ12 was directly downregulated by miR-200b. Conclusion: We provide evidence suggesting that SUZ12 may be a potential therapeutic target for gastric cancer.

  8. Capstone Depleted Uranium Aerosols: Generation and Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Parkhurst, MaryAnn; Szrom, Fran; Guilmette, Ray; Holmes, Tom; Cheng, Yung-Sung; Kenoyer, Judson L.; Collins, John W.; Sanderson, T. Ellory; Fliszar, Richard W.; Gold, Kenneth; Beckman, John C.; Long, Julie

    2004-10-19

    In a study designed to provide an improved scientific basis for assessing possible health effects from inhaling depleted uranium (DU) aerosols, a series of DU penetrators was fired at an Abrams tank and a Bradley fighting vehicle. A robust sampling system was designed to collect aerosols in this difficult environment and continuously monitor the sampler flow rates. Aerosols collected were analyzed for uranium concentration and particle size distribution as a function of time. They were also analyzed for uranium oxide phases, particle morphology, and dissolution in vitro. The resulting data provide input useful in human health risk assessments.

  9. Heatstroke Pathophysiology: The Energy Depletion Model

    Science.gov (United States)

    1989-06-12

    Pathophysiology: The Energy Depletion Model Roger W. Hubbard, Ph.D., Director Heat Research Division U. S. Army Research Institute of Environmental...Medicine Natick, MA 01760-5007 USA Send correspondence to: Roger W. Hubbard, Ph.D. Director Heat Research Division USARIEM Kansas St Natick, MA 01760...The NaK-Pump. Part B: Celular Asoects J.C. Skou, J.G. Normy, A.B. Maunsback, and M. Esmann (Eds) New York: Alan R. Uss, 1988, pp. 171-194. 54: Lewis

  10. Correlation between cosmic rays and ozone depletion.

    Science.gov (United States)

    Lu, Q-B

    2009-03-20

    This Letter reports reliable satellite data in the period of 1980-2007 covering two full 11-yr cosmic ray (CR) cycles, clearly showing the correlation between CRs and ozone depletion, especially the polar ozone loss (hole) over Antarctica. The results provide strong evidence of the physical mechanism that the CR-driven electron-induced reaction of halogenated molecules plays the dominant role in causing the ozone hole. Moreover, this mechanism predicts one of the severest ozone losses in 2008-2009 and probably another large hole around 2019-2020, according to the 11-yr CR cycle.

  11. Optical assessment of phytoplankton nutrient depletion

    DEFF Research Database (Denmark)

    Heath, M.R.; Richardson, Katherine; Kiørboe, Thomas

    1990-01-01

    status (carbon/nitrogen ratio) and the absorption ratio that was independent of light and temperature climate. The absorption ratio for nutrient-replete cells was shown to vary between taxonomic groups. However, the inter-specific variation was less than the differences observed between nutrient......-replete and nutrient-depleted cells. The field data suggest that the absorption ratio may be a useful indicator of nutritional status of natural phytoplankton populations, and can be used to augment the interpretation of other data....

  12. The Time of Shipbuilding Order Depletion

    Institute of Scientific and Technical Information of China (English)

    Reporter Xing Dan

    2012-01-01

    In 2012, shipbuilding market is facing even colder weather. Depletion of orders, deals that can only ensure cost recovery ndustry which has already bankruptcy of ship yards one after another are also torturing this had many uncertainties. Some shipbuilding enterprises are trying to survive by cutting off parts of their business, some enterprises are leaving like the horses migrating on the African grassland, only those horses that have fights with crocodiles will reach the fertile land and enjoy the next warm spring. the business. It is survived the fierce

  13. RESERVOIR CAPACITY DEPLETION ON ACCOUNT OF SEDIMENTATION

    Institute of Scientific and Technical Information of China (English)

    Prabhata K.SWAMEE

    2001-01-01

    Capacity depletion is an important information required for planning of multipurpose reservoirs. It is a complex phenomenon involving diverse fields like surface hydrology, sediment transport, varied flow hydraulics and soil consolidation. Proper assessment of capacity reduction is helpful in ascertaining the life of the reservoir and the project benefits for cost/benefit analysis. In this study dimensionally consistent equations for deposition volume and the trap efficiency have been obtained. Methods of obtaining the parameters involved these equations have also been indicated. It was found that there is good agreement with the field data. It is hoped that the equations are useful to design engineer.

  14. The Importance of Inputs to the Nankai Trough Subduction Zone: Integration of Results from ODP and IODP Drilling Transects in the Shikoku Basin

    Science.gov (United States)

    Underwood, M.; Saito, S.; Henry, P.; Kanamatsu, T.; Scientific Teams of IODP Expeditions 322; 333

    2011-12-01

    Three ODP and IODP drilling transects have been completed across the Nankai Trough subduction zone: Ashizuri, Muroto, and Kumano. An essential component of each transect is the so-called "reference site" seaward of the trench (ODP Sites 1173 and 1177; IODP Sites C0011 and C0012). These Shikoku Basin deposits are unusually heterogeneous, which means that virtually all types of frictional, geotechnical, and hydrogeological properties (including pore pressure) vary in 3-D both landward and seaward of the subduction front. By integrating drilling results from the three transects, we recognize the following basin-wide highlights: (1) Boundaries between lithologic units are not time-correlative. As an example, the base of the upper Shikoku Basin unit (hemipelagic/pyroclastic facies) varies in age from 7.8 Ma (C0012) to 3.3 Ma (1173). (2) A basin-wide boundary caused by diagenesis of dispersed volcanic glass shifts its stratigraphic position, with host-sediment ages that range from 5.2 Ma (C0011) to 3.3 Ma (1173). This reaction is important because it affects both porosity and interstitial water geochemistry prior to subduction. (3) Units of siliciclastic and volcaniclastic turbidites occur at middle to lower depths of the stratigraphy, but they cannot be correlated from the west to the east side of the basin. Activity within those channelized and sheet-flow turbidite systems was sensitive to changes in detrital provenance, as well as autocyclic and allocyclic forcing. (4) Clay mineral assemblages changed consistently through time. Muds deposited during the early and middle Miocene are highly enriched in smectite (>45 wt-% of bulk mud), which maximizes volumetric fluid production as strata move down the plate interface and experience smectite dehydration. (5) Because of unusually high heat flow, smectite-to-illite diagenesis begins outboard of the subduction front along the Muroto transect. That local effect of S=>I diagenesis obscures the basin-wide temporal trends in

  15. Cyclin D1 depletion induces DNA damage in mantle cell lymphoma lines.

    Science.gov (United States)

    Mohanty, Suchismita; Mohanty, Atish; Sandoval, Natalie; Tran, Thai; Bedell, Victoria; Wu, Jun; Scuto, Anna; Murata-Collins, Joyce; Weisenburger, Dennis D; Ngo, Vu N

    2017-03-01

    Elevated cyclin D1 (CCND1) expression levels in mantle cell lymphoma (MCL) are associated with aggressive clinical manifestations related to chemoresistance, but little is known about how this important proto-oncogene contributes to the resistance of MCL. Here, we showed that RNA interference-mediated depletion of CCND1 increased caspase-3 activities and induced apoptosis in the human MCL lines UPN-1 and JEKO-1. In vitro and xenotransplant studies revealed that the toxic effect of CCND1 depletion in MCL cells was likely due to increase in histone H2AX phosphorylation, a DNA damage marker. DNA fiber analysis suggested deregulated replication initiation after CCND1 depletion as a potential cause of DNA damage. Finally, in contrast to depletion or inhibition of cyclin-dependent kinase 4, CCND1 depletion increased chemosensitivity of MCL cells to replication inhibitors hydroxyurea and cytarabine. Our findings have an important implication for CCND1 as a potential therapeutic target in MCL patients who are refractory to standard chemotherapy.

  16. Records of natural fire and climate history during the last three glacial-interglacial cycles around the South China Sea Charcoal record from the ODP 1144

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The history of natural fire and its relationship to climate during the last three gla cial-interglacial cycles in the Southern coast areas of China and the northern continental shelf of the South China Sea (SCS) are discussed based on the statistic study of charcoal particles and associated pollen data from ODP 1144 Site (20° 3′N, 117° 25′E, 2037 m in water depth). Accord ing to the results of the charcoal and pollen study, the sediments from the upper 225 m are divided into 8 zones (C1-8), which might be correlated with the Marine Isotope Stage 1-8 (MIS1-8)respectively. Our study indicates that during the last glacial period (MIS2, 4), the influx of charcoal particle was much higher than that from the interglacial period, suggesting strong occurrence of natural fire and dry climate. During MIS 6 and MIS 8 (C6, C8), although the influx of fine charcoal particles was quite high, the influx of the coarse and medium charcoal particle were much low,which might be due to the smaller source area of fire probably resulting from the limited exposure of the continental shelf before MIS5. During the interglacial period (MIS1, 5, 7), the influxes of charcoal particles were much lower, implying dropping of intensity of the natural fire and then a humid climate. Another reason is that the continental shelf was submerged into the sea during the interglacial periods, and the source areas of fire were reduced then. Although the influx of the fine charcoal particles was much lower during MIS3, the influx of the coarse and medium charcoal par ticles were almost equal to those of MIS4 (C4), which suggests that the intensity of the natural fire remained quite high and the climate was considerably dry during that period.

  17. Simulations and observations of plasma depletion, ion composition, and airglow emissions in two auroral ionospheric depletion experiments

    Science.gov (United States)

    Yau, A. W.; Whalen, B. A.; Harris, F. R.; Gattinger, R. L.; Pongratz, M. B.

    1985-01-01

    Observations of plasma depletion, ion composition modification, and airglow emissions in the Waterhole experiments are presented. The detailed ion chemistry and airglow emission processes related to the ionospheric hole formation in the experiment are examined, and observations are compared with computer simulation results. The latter indicate that the overall depletion rates in different parts of the depletion region are governed by different parameters.

  18. Glutathione Depletion Induces Spermatogonial Cell Autophagy.

    Science.gov (United States)

    Mancilla, Héctor; Maldonado, Rodrigo; Cereceda, Karina; Villarroel-Espíndola, Franz; Montes de Oca, Marco; Angulo, Constanza; Castro, Maite A; Slebe, Juan C; Vera, Juan C; Lavandero, Sergio; Concha, Ilona I

    2015-10-01

    The development and survival of male germ cells depend on the antioxidant capacity of the seminiferous tubule. Glutathione (GSH) plays an important role in the antioxidant defenses of the spermatogenic epithelium. Autophagy can act as a pro-survival response during oxidative stress or nutrient deficiency. In this work, we evaluated whether autophagy is involved in spermatogonia-type germ cell survival during severe GSH deficiency. We showed that the disruption of GSH metabolism with l-buthionine-(S,R)-sulfoximine (BSO) decreased reduced (GSH), oxidized (GSSG) glutathione content, and GSH/GSSG ratio in germ cells, without altering reactive oxygen species production and cell viability, evaluated by 2',7'-dichlorodihydrofluorescein (DCF) fluorescence and exclusion of propidium iodide assays, respectively. Autophagy was assessed by processing the endogenous protein LC3I and observing its sub-cellular distribution. Immunoblot and immunofluorescence analysis showed a consistent increase in LC3II and accumulation of autophagic vesicles under GSH-depletion conditions. This condition did not show changes in the level of phosphorylation of AMP-activated protein kinase (AMPK) or the ATP content. A loss in S-glutathionylated protein pattern was also observed. However, inhibition of autophagy resulted in decreased ATP content and increased caspase-3/7 activity in GSH-depleted germ cells. These findings suggest that GSH deficiency triggers an AMPK-independent induction of autophagy in germ cells as an adaptive stress response. © 2015 Wiley Periodicals, Inc.

  19. Equatorial airglow depletions induced by thermospheric winds

    Energy Technology Data Exchange (ETDEWEB)

    Meriwether, J.W.; Biondi, M.A.; Anderson, D.N.

    1985-08-01

    Interferometric observations on the 630.0 nm nightglow brightness at the equatorial station at Arequipa, Peru (16.2 S, 71.4 W geographic, 3.2 S dip latitude) have revealed widespread areas of airglow depletion, with reductions in intensity as large as factors of 3 or 4. These depletions correlated closely with large increases of the equatorward (northward) wind and the 630.0 nm kinetic temperature. On occasion, the usually small meridional wind reached a velocity of 100 m/s near 22h LT lasting for 1 to 2 hours. The temperature increases of 100K or more existed only in the poleware (southward) direction. Comparisons with modeling calculations suggest that this effect results from an upward movement of the ionosphere along the inclined magnetic field lines, driven by the equatorward neutral wind. The airglow column integrated emission rate is consequently decreased by the slower rate of formation and subsequent dissociative recombination of molecular oxygen ions within the higher F-layer. We conclude that the transient period of equatorward wind is a result of the passage of the midnight pressure bulge. (Author)

  20. Equatorial airglow depletions induced by thermospheric winds

    Energy Technology Data Exchange (ETDEWEB)

    Meriwether J.W. Jr.; Biondi, M.A.; Anderson, D.N.

    1985-08-01

    Interferometric observations of the 630.0 nm nightglow brightness at the equatorial station of Arequipa. Peru (16.2/sup 0/S, 71.4/sup 0/W geographic, 3.2/sup 0/S dip latitude) have revealed widespread areas of airglow depletion, with reductions in intensity as large as factors of 3 or 4. These depletions correlated closely with large increases of the equatorward (northward) wind and the 630.0 nm kinetic temperature. On occasion, the usually small meridonal wind reached a velocity of 100 m/s near 22/sup h/ LT lasting for 1 or 2 hours. The temperature increases of 10 K or more existed only in the poleward (southward) direction. Comparisons with modeling calculations suggest that this effect results from an upward movement of the ionosphere along the inclined magnetic field lines, driven by the equatorward neutral wind. The airglow column integrated emission rate is consequently decreased by the slower rate of formation and subsequent dissociative recombination of molecular oxygen ions within the higher F-layer. We conclude that the transient period of equatorward wind is a result of the passage of the midnight pressure bulge.

  1. Abundances and Depletions of Interstellar Oxygen

    Science.gov (United States)

    Jensen, A. G.; Rachford, B. L.; Snow, T. P.

    2003-12-01

    We extend previous work on interstellar oxygen abundances with the addition of data from the Far Ultraviolet Spectroscopic Explorer (FUSE). We report on the abundance of interstellar neutral oxygen (OI) for several sightlines, using data from FUSE, the International Spectroscopic Explorer (IUE), and the Hubble Space Telescope (HST). OI column densities are derived by measuring the equivalent widths of several ultraviolet absorption lines, and subsequently fitting those to a curve of growth. The column densities of our best-constrained sightlines show a ratio of O/H that agrees with the current best solar value if dust is considered. We do not see evidence of enhanced depletion of gas-phase oxygen that is systematically variable with respect to the physical parameters of different environments (e.g., reddening or molecular fraction). The column densities of our less well-constrained sightlines show some scatter in O/H, but many agree with the solar value to within errors. We discuss these results in the context of deriving the best methods for determining interstellar abundances, the unresolved question of the best value for O/H in the interstellar medium (ISM), the O/H ratio observed in Galactic stars, and the depletion of gas-phase oxygen onto dust grains. Financial support for this research has been provided by the National Science Foundation GK-12 Program and NASA contract NAS 5-32985.

  2. Fully-depleted silicon-on-sapphire and its application to advanced VLSI design

    Science.gov (United States)

    Offord, Bruce W.

    1992-01-01

    In addition to the widely recognized advantages of full dielectric isolation, e.g., reduced parasitic capacitance, transient radiation hardness, and processing simplicity, fully-depleted silicon-on-sapphire offers reduced floating body effects and improved thermal characteristics when compared to other silicon-on-insulator technologies. The properties of this technology and its potential impact on advanced VLSI circuitry will be discussed.

  3. Profound peripheral T-lymphocyte depletion and activation in disseminated tuberculosis

    Directory of Open Access Journals (Sweden)

    Denise Silva Rodrigues

    2006-02-01

    Full Text Available Three HIV-1-seronegative patients with disseminated tuberculosis presented significant depletion of T-cell counts, in CD4+ and/or CD8+ cells, associated with increased expression of activation marker CD38 on CD8+ T-lymphocytes. This finding raises the question of potential mechanisms involved in the activation or loss of T-cells in disseminated tuberculosis.

  4. Depletive stripping chronopotentiometry : a major step forward in electrochemical stripping techniques for metal ion speciation analysis

    NARCIS (Netherlands)

    Town, R.M.; Leeuwen, van H.P.

    2004-01-01

    A comparative evaluation of the utility of the various modes of stripping chronopotentiometry (SCP) for trace metal speciation analysis is presented in the broad context of stripping voltammetric techniques. The remarkable fundamental advantages of depletive SCP at scanned deposition potential (SSCP

  5. Effect of uncouplers on "downhill" beta-galactoside transport in energy-depleted cells of Escherichia coli.

    Science.gov (United States)

    Cecchini, G; Koch, A L

    1975-01-01

    Galactoside permease-containing cells of Escherichia coli can be depleted of energy reserves so that the "downhill" cellular hydrolysis of o-nitrophenyl-beta-d-galactopyranoside (ONPG) no longer takes place. Treatment of such energy-depleted cells with proton-conducting agents such as carbonylcyanide m-chlorophenylhydrazone results in stimulation of ONPG transport. The same agents lower transport of non-energy-depleted cells towards the same levels that result from stimulation of the energy depleted cells. Of course, these agents prevent "uphill" accumulation against a concentration gradient under all conditions. Since uncouplers allow normal and energy-depleted cells to assume the same facilitated transport capability, these results lend support to the chemiosmotic hypothesis of Mitchell that comigration of charge is necessary for the transport of neutral galactosides. Our results imply that a potential favorable to transport is maintained by metabolism in non-energy-depleted cells, whereas an unfavorable potential is developed in the initial instant of time when energy-depleted cells are given ONPG. PMID:1095550

  6. Depletion of Arctic ozone in the winter 1990

    Science.gov (United States)

    Koike, M.; Kondo, Y.; Hayashi, M.; Iwasaka, Y.; Newman, P. A.

    1991-01-01

    Ozone mixing ratios were measured by ozonesondes on board balloons launched from Esrange, near Kiruna, Sweden (68 deg N, 20 deg E) from January 11 to February 9, 1990. The data obtained prior to a sudden warming on February 7, 1990 show that at potential temperatures between 460 and 640 K, the ozone mixing ratio just inside the polar vortex was systematically smaller than that outside, the largest difference being 29 percent at around 525 K. The ozone mixing ratio at 525 K inside the vortex decreased at a rate of about 1.5 percent per day between January 26 and February 4. The temperatures simultaneously observed were quite often low enough to allow for formation of nitric acid trihydrate particles around this altitude. Depletion of ozone due to highly perturbed chemical conditions in late January and early February is strongly suggested.

  7. Large-Scale Depletion of CD25+ Regulatory T Cells from Patient Leukapheresis Samples

    Science.gov (United States)

    Powell, Daniel J.; Parker, Linda L.; Rosenberg, Steven A.

    2006-01-01

    Summary The ability to selectively enrich or deplete T lymphocytes of specific phenotype and function holds significant promise for application in adoptive immunotherapy protocols. Although CD4+ T cells can have an impact on CD8+ T-cell effector function, memory, and maintenance, a subset of CD4+ T cells, CD25+ regulatory T cells (Treg), can regulate peripheral self tolerance and possess the ability to suppress antitumor responses. The authors report the ability to selectively deplete CD25+ Treg cells from patient leukapheresis samples using a clinical-grade, large-scale immunomagnetic system. Using leukapheresis samples containing up to 1.3 × 1010 white blood cells, efficient depletion of Treg cells was measured by flow cytometric analysis of CD25 expression and FOXP3 expression on post-depletion products. Remnant CD25+ cells could not be detected in CD25-depleted products after short-term culture in IL-2 or enriched following secondary immunomagnetic selection for CD25+ cells, confirming that efficient depletion had occurred. In parallel to efficient enrichment of CD25− cells, immunomagnetic selection resulted in the recovery of Treg cells, since CD25+ lymphocytes removed during depletion were primarily composed of CD4+ T cells that expressed high levels of FOXP3 and possessed suppressive activity against autologous TCR-stimulated CD4+ CD25− T cells in vitro. These results show that selective separation of functional CD25+ Treg cells from large-scale samples can be performed in large scale under clinical-grade conditions with sufficient selection, recovery, viability, ability to expand, and function for potential use in adoptive immunotherapy. PMID:16000960

  8. Southwestern Tropical Atlantic coral growth response to atmospheric circulation changes induced by ozone depletion in Antarctica

    Directory of Open Access Journals (Sweden)

    H. Evangelista

    2015-08-01

    Full Text Available Climate changes induced by stratospheric ozone depletion over Antarctica have been recognized as an important consequence of the recently observed Southern Hemisphere atmospheric circulation. Here we present evidences that the Brazilian coast (Southwestern Atlantic may have been impacted from both winds and sea surface temperature changes derived from this process. Skeleton analysis of massive coral species living in shallow waters off Brazil are very sensitive to air–sea interactions, and seem to record this impact. Growth rates of Brazilian corals show a trend reversal that fits the ozone depletion evolution, confirming that ozone impacts are far reaching and potentially affect coastal ecosystems in tropical environments.

  9. Endothelium-dependent vasorelaxation in inhibited by in vivo depletion of vascular thiol levels

    DEFF Research Database (Denmark)

    Laursen, J B; Boesgaard, S; Trautner, S;

    2001-01-01

    Thiols like glutathione may serve as reducing cofactors in the production of nitric oxide (NO) and protect NO from inactivation by radical oxygen species. Depletion of thiol compounds reduces NO-mediated vascular effects in vitro and in vivo. The mechanisms underlying these actions are not clear......, but may involve decreased synthesis of NO and/or increased degradation of NO. This study investigates the effect of glutathione depletion on the response to NO-mediated vasodilation induced by acetylcholine (Ach, 10 micrograms/kg), endothelial NO synthase (eNOS) activity and potential markers of vascular...

  10. Uplift and seismicity driven by groundwater depletion in central California.

    Science.gov (United States)

    Amos, Colin B; Audet, Pascal; Hammond, William C; Bürgmann, Roland; Johanson, Ingrid A; Blewitt, Geoffrey

    2014-05-22

    Groundwater use in California's San Joaquin Valley exceeds replenishment of the aquifer, leading to substantial diminution of this resource and rapid subsidence of the valley floor. The volume of groundwater lost over the past century and a half also represents a substantial reduction in mass and a large-scale unburdening of the lithosphere, with significant but unexplored potential impacts on crustal deformation and seismicity. Here we use vertical global positioning system measurements to show that a broad zone of rock uplift of up to 1-3 mm per year surrounds the southern San Joaquin Valley. The observed uplift matches well with predicted flexure from a simple elastic model of current rates of water-storage loss, most of which is caused by groundwater depletion. The height of the adjacent central Coast Ranges and the Sierra Nevada is strongly seasonal and peaks during the dry late summer and autumn, out of phase with uplift of the valley floor during wetter months. Our results suggest that long-term and late-summer flexural uplift of the Coast Ranges reduce the effective normal stress resolved on the San Andreas Fault. This process brings the fault closer to failure, thereby providing a viable mechanism for observed seasonality in microseismicity at Parkfield and potentially affecting long-term seismicity rates for fault systems adjacent to the valley. We also infer that the observed contemporary uplift of the southern Sierra Nevada previously attributed to tectonic or mantle-derived forces is partly a consequence of human-caused groundwater depletion.

  11. Multi-scale entropic depletion phenomena in polymer liquids

    Science.gov (United States)

    Banerjee, Debapriya; Schweizer, Kenneth S.

    2015-06-01

    We apply numerical polymer integral equation theory to study the entropic depletion problem for hard spheres dissolved in flexible chain polymer melts and concentrated solutions over an exceptionally wide range of polymer radius of gyration to particle diameter ratios (Rg/D), particle-monomer diameter ratios (D/d), and chain lengths (N) including the monomer and oligomer regimes. Calculations are performed based on a calibration of the effective melt packing fraction that reproduces the isobaric dimensionless isothermal compressibility of real polymer liquids. Three regimes of the polymer-mediated interparticle potential of mean force (PMF) are identified and analyzed in depth. (i) The magnitude of the contact attraction that dominates thermodynamic stability scales linearly with D/d and exhibits a monotonic and nonperturbative logarithmic increase with N ultimately saturating in the long chain limit. (ii) A close to contact repulsive barrier emerges that grows linearly with D/d and can attain values far in excess of thermal energy for experimentally relevant particle sizes and chain lengths. This raises the possibility of kinetic stabilization of particles in nanocomposites. The barrier grows initially logarithmically with N, attains a maximum when 2Rg ˜ D/2, and then decreases towards its asymptotic long chain limit as 2Rg ≫ D. (iii) A long range (of order Rg) repulsive, exponentially decaying component of the depletion potential emerges when polymer coils are smaller than, or of order, the nanoparticle diameter. Its amplitude is effectively constant for 2Rg ≤ D. As the polymer becomes larger than the particle, the amplitude of this feature decreases extremely rapidly and becomes negligible. A weak long range and N-dependent component of the monomer-particle pair correlation function is found which is suggested to be the origin of the long range repulsive PMF. Implications of our results for thermodynamics and miscibility are discussed.

  12. Multi-scale entropic depletion phenomena in polymer liquids

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Debapriya [Department of Materials Science, University of Illinois, Urbana, Illinois 61801 (United States); Schweizer, Kenneth S., E-mail: kschweiz@illinois.edu [Department of Materials Science, University of Illinois, Urbana, Illinois 61801 (United States); Department of Chemistry, University of Illinois, Urbana, Illinois 61801 (United States); Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States)

    2015-06-07

    We apply numerical polymer integral equation theory to study the entropic depletion problem for hard spheres dissolved in flexible chain polymer melts and concentrated solutions over an exceptionally wide range of polymer radius of gyration to particle diameter ratios (R{sub g}/D), particle-monomer diameter ratios (D/d), and chain lengths (N) including the monomer and oligomer regimes. Calculations are performed based on a calibration of the effective melt packing fraction that reproduces the isobaric dimensionless isothermal compressibility of real polymer liquids. Three regimes of the polymer-mediated interparticle potential of mean force (PMF) are identified and analyzed in depth. (i) The magnitude of the contact attraction that dominates thermodynamic stability scales linearly with D/d and exhibits a monotonic and nonperturbative logarithmic increase with N ultimately saturating in the long chain limit. (ii) A close to contact repulsive barrier emerges that grows linearly with D/d and can attain values far in excess of thermal energy for experimentally relevant particle sizes and chain lengths. This raises the possibility of kinetic stabilization of particles in nanocomposites. The barrier grows initially logarithmically with N, attains a maximum when 2R{sub g} ∼ D/2, and then decreases towards its asymptotic long chain limit as 2R{sub g} ≫ D. (iii) A long range (of order R{sub g}) repulsive, exponentially decaying component of the depletion potential emerges when polymer coils are smaller than, or of order, the nanoparticle diameter. Its amplitude is effectively constant for 2R{sub g} ≤ D. As the polymer becomes larger than the particle, the amplitude of this feature decreases extremely rapidly and becomes negligible. A weak long range and N-dependent component of the monomer-particle pair correlation function is found which is suggested to be the origin of the long range repulsive PMF. Implications of our results for thermodynamics and miscibility are

  13. Multi-scale entropic depletion phenomena in polymer liquids

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, D [Oak Ridge National Laboratory (ORNL); Schweizer, Kenneth S [ORNL

    2015-01-01

    In this paper, we apply numerical polymer integral equationtheory to study the entropic depletion problem for hard spheres dissolved in flexible chain polymer melts and concentrated solutions over an exceptionally wide range of polymer radius of gyration to particle diameter ratios (Rg/D), particle-monomer diameter ratios (D/d), and chain lengths (N) including the monomer and oligomer regimes. Calculations are performed based on a calibration of the effective melt packing fraction that reproduces the isobaric dimensionless isothermal compressibility of real polymer liquids. Three regimes of the polymer-mediated interparticle potential of mean force (PMF) are identified and analyzed in depth. (i) The magnitude of the contact attraction that dominates thermodynamic stability scales linearly with D/d and exhibits a monotonic and nonperturbative logarithmic increase with N ultimately saturating in the long chain limit. (ii) A close to contact repulsive barrier emerges that grows linearly with D/d and can attain values far in excess of thermal energy for experimentally relevant particle sizes and chain lengths. This raises the possibility of kinetic stabilization of particles in nanocomposites. The barrier grows initially logarithmically with N, attains a maximum when 2Rg ~ D/2, and then decreases towards its asymptotic long chain limit as 2Rg >> D. (iii) A long range (of order Rg) repulsive, exponentially decaying component of the depletion potential emerges when polymer coils are smaller than, or of order, the nanoparticle diameter. Its amplitude is effectively constant for 2Rg ≤ D. As the polymer becomes larger than the particle, the amplitude of this feature decreases extremely rapidly and becomes negligible. A weak long range and N-dependent component of the monomer-particle pair correlation function is found which is suggested to be the origin of the long range repulsive PMF. Finally, implications of our

  14. Depleted Uranium Penetrators : Hazards and Safety

    Directory of Open Access Journals (Sweden)

    S. S. Rao

    1997-01-01

    Full Text Available The depleted uranium (DU alloy is a state-of-the-art material for kinetic energy penetrators due to its superior ballistic performance. Several countries use DU penetrators in their main battle tanks. There is no gamma radiation hazard to the crew members from stowage of DO rounds. Open air firing can result in environmental contamination and associated hazards due to airborne particles containing essentially U/sub 3/0/sub 8/ and UO/sub 2/. Inhalation of polluted air only through respirators or nose masks and refraining form ingestion of water or food materials from contaminated environment are safety measures for avoiding exposure to uranium and its toxicity. Infusion of sodium bicarbonate helps in urinary excretion of uranium that may have entered the body.

  15. Arctic Ozone Depletion from UARS MLS Measurements

    Science.gov (United States)

    Manney, G. L.

    1995-01-01

    Microwave Limb Sounder (MLS) measurements of ozone during four Arctic winters are compared. The evolution of ozone in the lower stratosphere is related to temperature, chlorine monoxide (also measured by MLS), and the evolution of the polar vortex. Lagrangian transport calculations using winds from the United Kingdom Meteorological Office's Stratosphere-Troposphere Data Assimilation system are used to estimate to what extent the evolution of lower stratospheric ozone is controlled by dynamics. Observations, along with calculations of the expected dynamical behavior, show evidence for chemical ozone depletion throughout most of the Arctic lower stratospheric vortex during the 1992-93 middle and late winter, and during all of the 1994-95 winter that was observed by MLS. Both of these winters were unusually cold and had unusually cold and had unusually strong Arctic polar vortices compared to meteorological data over the past 17 years.

  16. Kinetic depletion model for pellet ablation

    Energy Technology Data Exchange (ETDEWEB)

    Kuteev, Boris V. [State Technical Univ., St. Petersburg (Russian Federation)

    2001-11-01

    A kinetic model for depletion effect, which determines pellet ablation when the pellet passes a rational magnetic surface, is formulated. The model predicts a moderate decrease of the ablation rate compared with the earlier considered monoenergy versions [1, 2]. For typical T-10 conditions the ablation rate reduces by a reactor of 2.5 when the 1-mm pellet penetrates through the plasma center. A substantial deceleration of pellets -about 15% per centimeter of low shire rational q region; is predicted. Penetration for Low Field Side and High Field Side injections is considered taking into account modification of the electron distribution function by toroidal magnetic field. It is shown that Shafranov shift and toroidal effects yield the penetration length for HFS injection higher by a factor of 1.5. This fact should be taken into account when plasma-shielding effects on penetration are considered. (author)

  17. Anxiety, ego depletion, and sports performance.

    Science.gov (United States)

    Englert, Chris; Bertrams, Alex

    2012-10-01

    In the present article, we analyzed the role of self-control strength and state anxiety in sports performance. We tested the hypothesis that self-control strength and state anxiety interact in predicting sports performance on the basis of two studies, each using a different sports task (Study 1: performance in a basketball free throw task, N = 64; Study 2: performance in a dart task, N = 79). The patterns of results were as expected in both studies: Participants with depleted self-control strength performed worse in the specific tasks as their anxiety increased, whereas there was no significant relation for participants with fully available self-control strength. Furthermore, different degrees of available self-control strength did not predict performance in participants who were low in state anxiety, but did in participants who were high in state anxiety. Thus increasing self-control strength could reduce the negative anxiety effects in sports and improve athletes' performance under pressure.

  18. Seasonal iron depletion in temperate shelf seas

    Science.gov (United States)

    Birchill, Antony J.; Milne, Angela; Woodward, E. Malcolm S.; Harris, Carolyn; Annett, Amber; Rusiecka, Dagmara; Achterberg, Eric P.; Gledhill, Martha; Ussher, Simon J.; Worsfold, Paul J.; Geibert, Walter; Lohan, Maeve C.

    2017-09-01

    Our study followed the seasonal cycling of soluble (SFe), colloidal (CFe), dissolved (DFe), total dissolvable (TDFe), labile particulate (LPFe), and total particulate (TPFe) iron in the Celtic Sea (NE Atlantic Ocean). Preferential uptake of SFe occurred during the spring bloom, preceding the removal of CFe. Uptake and export of Fe during the spring bloom, coupled with a reduction in vertical exchange, led to Fe deplete surface waters (<0.2 nM DFe; 0.11 nM LPFe, 0.45 nM TDFe, and 1.84 nM TPFe) during summer stratification. Below the seasonal thermocline, DFe concentrations increased from spring to autumn, mirroring NO3- and consistent with supply from remineralized sinking organic material, and cycled independently of particulate Fe over seasonal timescales. These results demonstrate that summer Fe availability is comparable to the seasonally Fe limited Ross Sea shelf and therefore is likely low enough to affect phytoplankton growth and species composition.

  19. Modelling chemical depletion profiles in regolith

    Science.gov (United States)

    Brantley, S.L.; Bandstra, J.; Moore, J.; White, A.F.

    2008-01-01

    Chemical or mineralogical profiles in regolith display reaction fronts that document depletion of leachable elements or minerals. A generalized equation employing lumped parameters was derived to model such ubiquitously observed patterns:C = frac(C0, frac(C0 - Cx = 0, Cx = 0) exp (??ini ?? over(k, ??) ?? x) + 1)Here C, Cx = 0, and Co are the concentrations of an element at a given depth x, at the top of the reaction front, or in parent respectively. ??ini is the roughness of the dissolving mineral in the parent and k???? is a lumped kinetic parameter. This kinetic parameter is an inverse function of the porefluid advective velocity and a direct function of the dissolution rate constant times mineral surface area per unit volume regolith. This model equation fits profiles of concentration versus depth for albite in seven weathering systems and is consistent with the interpretation that the surface area (m2 mineral m- 3 bulk regolith) varies linearly with the concentration of the dissolving mineral across the front. Dissolution rate constants can be calculated from the lumped fit parameters for these profiles using observed values of weathering advance rate, the proton driving force, the geometric surface area per unit volume regolith and parent concentration of albite. These calculated values of the dissolution rate constant compare favorably to literature values. The model equation, useful for reaction fronts in both steady-state erosional and quasi-stationary non-erosional systems, incorporates the variation of reaction affinity using pH as a master variable. Use of this model equation to fit depletion fronts for soils highlights the importance of buffering of pH in the soil system. Furthermore, the equation should allow better understanding of the effects of important environmental variables on weathering rates. ?? 2008.

  20. Parametric Analysis of PWR Spent Fuel Depletion Parameters for Long-Term-Disposal Criticality Safety

    Energy Technology Data Exchange (ETDEWEB)

    DeHart, M.D.

    1999-08-01

    Utilization of burnup credit in criticality safety analysis for long-term disposal of spent nuclear fuel allows improved design efficiency and reduced cost due to the large mass of fissile material that will be present in the repository. Burnup-credit calculations are based on depletion calculations that provide a conservative estimate of spent fuel contents (in terms of criticality potential), followed by criticality calculations to assess the value of the effective neutron multiplication factor (k(sub)eff) for the a spent fuel cask or a fuel configuration under a variety of probabilistically derived events. In order to ensure that the depletion calculation is conservative, it is necessary to both qualify and quantify assumptions that can be made in depletion models.

  1. Environmental effects of ozone depletion and its interactions with climate change: progress report, 2007.

    Science.gov (United States)

    2008-01-01

    This year the Montreal Protocol celebrates its 20th Anniversary. In September 1987, 24 countries signed the Montreal Protocol on Substances that Deplete the Ozone Layer. Today 191 countries have signed and have met strict commitments on phasing out of ozone depleting substances with the result that a 95% reduction of these substances has been achieved. The Montreal Protocol has also contributed to slowing the rate of global climate change, since most of the ozone depleting substances are also effective greenhouse gases. Even though much has been achieved, the future of the stratospheric ozone layer relies on full compliance of the Montreal Protocol by all countries for the remaining substances, including methyl bromide, as well as strict monitoring of potential risks from the production of substitute chemicals. Also the ozone depleting substances existing in banks and equipment need special attention to prevent their release to the stratosphere. Since many of the ozone depleting substances already in the atmosphere are long-lived, recovery cannot be immediate and present projections estimate a return to pre-1980 levels by 2050 to 2075. It has also been predicted that the interactions of the effects of the ozone layer and that of other climate change factors will become increasingly important.

  2. Ozone depletion and UVB radiation: impact on plant DNA damage in southern South America.

    Science.gov (United States)

    Rousseaux, M C; Ballaré, C L; Giordano, C V; Scopel, A L; Zima, A M; Szwarcberg-Bracchitta, M; Searles, P S; Caldwell, M M; Díaz, S B

    1999-12-21

    The primary motivation behind the considerable effort in studying stratospheric ozone depletion is the potential for biological consequences of increased solar UVB (280-315 nm) radiation. Yet, direct links between ozone depletion and biological impacts have been established only for organisms of Antarctic waters under the influence of the ozone "hole;" no direct evidence exists that ozone-related variations in UVB affect ecosystems of temperate latitudes. Indeed, calculations based on laboratory studies with plants suggest that the biological impact of ozone depletion (measured by the formation of cyclobutane pyrimidine dimers in DNA) is likely to be less marked than previously thought, because UVA quanta (315-400 nm) may also cause significant damage, and UVA is unaffected by ozone depletion. Herein, we show that the temperate ecosystems of southern South America have been subjected to increasingly high levels of ozone depletion during the last decade. We found that in the spring of 1997, despite frequent cloud cover, the passages of the ozone hole over Tierra del Fuego (55 degrees S) caused concomitant increases in solar UV and that the enhanced ground-level UV led to significant increases in DNA damage in the native plant Gunnera magellanica. The fluctuations in solar UV explained a large proportion of the variation in DNA damage (up to 68%), particularly when the solar UV was weighted for biological effectiveness according to action spectra that assume a sharp decline in quantum efficiency with increasing wavelength from the UVB into the UVA regions of the spectrum.

  3. Tuning of electrostatic vs. depletion interaction in deciding the phase behavior of nanoparticle-polymer system

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sugam, E-mail: sugam@barc.gov.in; Aswal, V. K. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kohlbrecher, J. [Laboratory for Neutron Scattering, Paul Scherrer Institut, H-5232 PSI Villigen (Switzerland)

    2015-06-24

    Nanoparticle-polymer system interestingly show a re-entrant phase behavior where charge stabilized silica nanoparticles (phase I) undergo particle clustering (phase II) and then back to individual particles (phase I) as a function of polymer concentration. Such phase behavior arises as a result of dominance of various interactions (i) nanoparticle-nanoparticle electrostatic repulsion (ii) polymer induced attractive depletion between nanoparticles and (iii) polymer-polymer repulsion, at different concentration regimes. Small-angle neutron scattering (SANS) has been used to study the evolution of interaction during this re-entrant phase behavior of nanoparticles by contrast-marching the polymer. The SANS data have been modeled using a two-Yukawa potential accounting for both attractive and repulsive parts of the interaction between nanoparticles. The degree of both of these parts has been separately tuned by varying the polymer concentration and ionic strength of the solution. Both of these parts are found to have long-range nature. At low polymer concentrations, the electrostatic repulsion dominates over the depletion attraction. The magnitude and the range of the depletion interaction increase with the polymer concentration leading to nanoparticle clustering. At higher polymer concentrations, the increased polymer-polymer repulsion reduces the strength of depletion leading to re-entrant phase behavior. The clusters formed under depletion attraction are found to have surface fractal morphology.

  4. Auranofin induces apoptosis and necrosis in HeLa cells via oxidative stress and glutathione depletion.

    Science.gov (United States)

    You, Bo Ra; Shin, Hye Rim; Han, Bo Ram; Kim, Suhn Hee; Park, Woo Hyun

    2015-02-01

    Auranofin (Au), an inhibitor of thioredoxin reductase, is a known anti‑cancer drug. In the present study, the anti‑growth effect of Au on HeLa cervical cancer cells was examined in association with levels of reactive oxygen species (ROS) and glutathione (GSH). Au inhibited the growth of HeLa cells with an IC50 of ~2 µM at 24 h. This agent induced apoptosis and necrosis, accompanied by the cleavage of poly (ADP‑ribose) polymerase and loss of mitochondrial membrane potential. The pan‑caspase inhibitor, benzyloxycarbonyl‑Val‑Ala‑Asp‑fluoromethylketone, prevented apoptotic cell death and each of the assessed caspase inhibitors inhibited necrotic cell death induced by Au. With respect to the levels of ROS and GSH, Au increased intracellular O2•- in the HeLa cells and induced GSH depletion. The pan‑caspase inhibitor reduced the levels of O2•- and GSH depletion in Au‑treated HeLa cells. The antioxidant, N‑acetyl cysteine, not only attenuated apoptosis and necrosis in the Au‑treated HeLa cells, but also decreased the levels of O2•- and GSH depletion in the cells. By contrast, L‑buthionine sulfoximine, a GSH synthesis inhibitor, intensified cell death O2•- and GSH depletion in the Au‑treated HeLa cells. In conclusion, Au induced apoptosis and necrosis in HeLa cells via the induction of oxidative stress and the depletion of GSH.

  5. Behavioral cross-sensitization between morphine-induced locomotion and sodium depletion-induced salt appetite.

    Science.gov (United States)

    Na, Elisa S; Morris, Michael J; Johnson, Alan Kim

    2009-10-01

    In general terms, sensitization refers to the capacity of a repetitive stimulus of fixed strength to produce a progressive increase in the magnitude of a response with each stimulation. In the addiction literature cross-sensitization is the capacity of an agent with abuse potential to sensitize a behavioral response induced by another stimulus. In the present experiments we examined the effects of morphine pretreatment on furosemide-induced saline intake and conversely sodium appetite induction on morphine-induced locomotion. In an initial experiment rats were pretreated with morphine (10 mg/kg, s.c.) or vehicle for 5 days. The rats were then sodium or sham depleted and 24 h later given a sodium appetite test. Sodium depleted rats pretreated with morphine increased saline intake compared to depleted rats initially pretreated with vehicle. In a second experiment rats that were previously depleted and repleted of sodium as compared to sham depleted animals showed enhanced locomotor activity in an open field test when challenged with morphine (1 mg/kg, s.c.). These studies demonstrate that the behavioral responses induced by sodium deficiency and morphine treatment cross-sensitize with one another and suggest that common neural substrates underlie the sensitization of behaviors associated with states induced by morphine and sodium appetite.

  6. L'ouverture océanique au sud de la Tasmanie durant le Paléogène et ses conséquences paléocéanographiques: résultats préliminaires de la minéralogie des argiles (leg ODP 189)Palaeogene ocean opening south of Tasmania, and palaeoceanographic implications: preliminary results of clay mineral analyses (ODP Leg 189)

    Science.gov (United States)

    Robert, Christian M.; Exon, Neville F.; Kennett, James P.; Malone, Mitchell J.; Brinkhuis, Henk; Chaproniere, George C. H.; Ennyu, Atsuhito; Fothergill, Patrick; Fuller, Michael D.; Grauert, Marianne; Hill, Peter J.; Janecek, Thomas R.; Kelly, Daniel Clay; Latimer, Jennifer C.; McGonigal Roessig, Kristeen; Nees, Stefan; Ninnemann, Ulysses S.; Nürnberg, Dirk; Pekar, Stephen F.; Pellaton, Caroline C.; Pfühl, Helen A.; Röhl, Ursula; Schellenberg, Stephen A.; Shevenell, Amelia E.; Stickley, Catherine E.; Suzuki, Noritoshi; Touchard, Yannick; Wei, Wuchang; White, Timothy S.

    2001-03-01

    ODP Leg 189 was designed to test the hypothesis that opening of the Tasmanian Seaway and initiation of circumpolar circulation contributed to the thermal isolation of Antarctica, leading to the development of initial ice-sheet and oceanic thermohaline circulation. The clay assemblages of the Tasmanian region contain the traces of two tectonic stages associated with ocean opening south of the south Tasman Rise near the Palaeocene-Eocene boundary and strike-slip activity between the western Tasmanian land-bridge and Antarctica during the Late Eocene. Earliest Oligocene clays indicate that cooling of Antarctic margins and activity of western boundary circulation progressed with the regional subsidence.

  7. Age- and location-dependent differences in store depletion-induced h-channel plasticity in hippocampal pyramidal neurons

    OpenAIRE

    Clemens, Ann M.; Johnston, Daniel

    2013-01-01

    Disruptions of endoplasmic reticulum (ER) Ca2+ homeostasis are heavily linked to neuronal pathology. Depletion of ER Ca2+ stores can result in cellular dysfunction and potentially cell death, although adaptive processes exist to aid in survival. We examined the age and region dependence of one postulated, adaptive response to ER store-depletion (SD), hyperpolarization-activated cation-nonspecific (h)-channel plasticity in neurons of the dorsal and ventral hippocampus (DHC and VHC, respectivel...

  8. Paleoclimatic and Paleomagnetic Variability over the Past 40,000 Years as Recorded by Sediments at ODP Site 1002 in the Cariaco Basin

    Science.gov (United States)

    Verosub, K. L.; Acton, G.; Johnson, B.

    2005-05-01

    The Cariaco Basin, an anoxic basin off the coast of Venezuela, acts as a depocenter for sediments of marine and terrestrial origin. Sedimentation rates for the upper 170 m of sediment recovered during ODP Leg 165 at Site 1002 average 35 cm/k.y. and are fairly constant over the entire 600-k.y.-long interval cored. The high sedimentation rates and anoxic conditions have resulted in a very favorable setting for studying short-term changes in the paleoenvironment as recorded by geochemical and rock-magnetic variations. Paleomagnetic field variability is also recorded, although the sediments are less than ideal owing to their relatively weak magnetizations. Prior geochemical studies of Cariaco Basin sediments have shown that variations in Ti and Fe content correlate with changes in precipitation. These results are being augmented by XRF determinations of a wider range of elements, obtained using the Advanced Light Source at the Lawrence Berkeley National Laboratory. In the laminated intervals, the light and dark lamina that comprise a varve correspond with the drier winter-spring season and wetter summer-fall season, respectively. These changes are interpreted mainly as resulting from changes in the position of the Intertropical Convergence Zone (ITCZ), which currently passes over or near the Cariaco Basin during the summer-fall seasons and migrates well south of the basin in the winter-spring seasons. Several of the rock magnetic parameters that are sensitive to magnetic (Fe) concentration have much larger variations than do the geochemical data, with increases by more than an order of magnitude in several discrete intervals indicating large changes in the amount of Fe entering the basin. Although these changes are ideal for monitoring how the marine and terrigenous sources have abruptly changed over time, they are not favorable for constructing paleosecular variation or relative paleointensity records. Even so, the mean paleomagnetic inclination corresponds to the

  9. Tectonic erosion and consequent collapse of the Pacific margin of Costa Rica: Combined implications from ODP leg 170, seismic offshore data, and regional geology of the Nicoya Peninsula

    Science.gov (United States)

    Vannucchi, P.; Scholl, D. W.; Meschede, M.; McDougall-Reid, K.

    2001-01-01

    The convergent margin off the Pacific coast of the Nicoya Peninsula of Costa Rica exhibits evidence for subduction erosion caused by the underthrusting Cocos plate. Critical evidence for efficacy of this process was recovered at the Ocean Drilling Program (ODP) drilling Site 1042 (Leg 170), positioned ???7 km landward of the Middle America trench axis off the Nicoya Peninsula. The primary drilling objective at this site was to identify the age and origin of a regionally extensive and prominent seismic discontinuity, the so-called base-of-slope sediment (BOSS) horizon or surface. The BOSS horizon, which can be traced landward from near the trench to the Nicoya coastal area and parallel to it for hundreds of kilometers, separates a low-velocity (??? 2.0-2.5 km s-1) sequence of slope sediment, from an underlying sequence of much higher-velocity (> 4-4.5 km s-1) rock. Site 1042 reached the acoustically defined BOSS horizon at a below sea level depth of ??? 3900 m and yielded a carbonate-cemented calcarenitic breccia of early-middle Miocene age. Sedimentological, geochemical, paleontological, and cement paragenesis data document that the breccia accumulated in a shallow water depositional environment. On the basis of coastal exposures, the BOSS horizon, as a margin-wide geologic interface, can be temporally and lithostratigraphically correlated to a regional angular unconformity. This unconformity, known as the Mal Pais unconformity, separates Neogene and younger shelf-to-littoral beds from the underlying mafic units of the Mesozoic Nicoya Complex and Cretaceous and early Tertiary sedimentary sequences. At Site 1042 it is inferred that tectonism caused the vertical subsidence of the early Neogene breccia from a shallow to a deep water setting. The Mal Pais unconformity of the BOSS horizon thus connects the rock fabric of the outermost part of margin to that of coastal Nicoya and implies that in the early Neogene the Nicoya shelf extended seaward to near the present

  10. Links Between Variations of Clay Mineral Supply and Deep Oceanic Circulation Over The Last Million Years At Site 984, Odp Leg 162 (northwestern Atlantic Ocean)

    Science.gov (United States)

    Bout-Roumazeilles, V.; Davies, G.; Récourt, P.

    The high northern latitude oceans influence the global environment through the formation of seasonal ice cover, transfer of sensible and latent heat to the atmosphere, and by deep-water formation. The ODP site 984 was drilled in the northwestern Atlantic Ocean in order to monitor the intermediate and deep-water masses variability at Milankovitch timescale over the last million years. Site 984 is located on the Bjorn Drift (61°N 24°W) on the eastern flank of the Reykjanes Ridge. The site lies on the northwestern margin of the Iceland basin directly under the influence of overflows from the Iceland-Faeroe Ridge. This water-mass flows as a deep northern boundary current through the Charlie -Gibbs fracture zone, south of site 984. The presence and the evolution of sediment drifts are intimately linked with the deep-water circulation patterns in this region, and the drift is presently being sculpted by the NSOW water overflowing the Wyville -Thomson Ridge. The sedimentary sequence recovered at site 984 is characterized by unusually high sedimentation rates. Where fine-grained sediments settle out of the current nepheloid layer, large drifts build up that typically have very high sedimentation rates due to the excess of fine fraction. Thus site 984 provides a very good record of glacial- interglacial and millennial-scale variations in thermohaline circulation and ice- rafting history over the Pleistocene. The clay mineral fraction was studied at high resolution over the last million years. The fine size fraction is mainly composed of smectite and illite which variations display the familiar sequences of glacial and interglacial marine isotope stages. The supply in illite is low during interglacial intervals while the smectite supply is high. By contrast, sediments deposited during glacial periods are characterized by a high illite / low smectite content. These variations tend to indicate that there is a major change in fine particles provenance from glacial to

  11. Alkalic marine tephra layers at ODP Site 1241 - Major explosive eruptions from an oceanic volcano in a pre-shield stage?

    Science.gov (United States)

    Schindlbeck, J. C.; Kutterolf, S.; Freundt, A.; Andrews, G. D. M.; Wang, K.-L.; Völker, D.; Werner, R.; Frische, M.; Hoernle, K.

    2016-12-01

    We report a series of fourteen marine tephra layers that are the products of large explosive eruptions of Subplinian to Plinian intensities and magnitudes (VEI > 4) from Cocos Island, Costa Rica. Cocos Island is a volcanic island in the eastern Central Pacific Ocean 500 km offshore Costa Rica, and is situated on the northwestern flank of the aseismic Cocos Ridge. Geochemical fingerprinting of Pleistocene ( 2.4-1.4 Ma) marine tephra layers from Ocean Drilling Project (ODP) Leg 202 Site 1241 using major and trace element compositions of volcanic glass shards demonstrates unequivocally their origin from Cocos Island rather than the Galápagos Archipelago or the Central American Volcanic Arc (CAVA). Cocos Island and the adjacent seamounts of the Cocos Island Province have alkalic compositions and formed on young (≤ 3 Ma) oceanic crust from an extinct spreading ridge bounded by a transform fault against the older and thicker crust of the aseismic Cocos Ridge. Cocos Island has six times the average volume of the adjacent seamounts although all appear to have formed during the 3-1.4 Ma time period. Cocos Island lies closest to the transform fault and we explain its excessive growth by melts rising from garnet-bearing mantle being deflected from the thick Cocos Ridge lithosphere toward the thinner lithosphere on the other side of the transform, thus enlarging the melt catchment area for Cocos Island compared to the seamounts farther away from the transform. This special setting favored growth above sea level and subaerial explosive eruptions even though the absence of appropriate compositions suggests that the entirely alkalic Cocos Island (and seamounts) never evolved through the productive tholeiitic shield stage typical of other Pacific Ocean islands, possibly because melt production rates remained too small. Conditions of magma generation and ascent resembled Hawaiian pre-shield volcanoes but persisted for much longer (< 1 m.y.) and formed evolved, trachytic magmas

  12. Magmatism and metamorphism at the sheeted dyke-gabbro transition zone: new insight from beerbachite from ODP/IODP Hole 1256D and Oman ophiolite

    Science.gov (United States)

    Python, Marie; Abily, Bénédicte; France, Lydéric

    2014-05-01

    During IODP Expedition 335, two-pyroxenes bearing granulites (beerbachites) were extensively recovered as drilling cuttings at the gabbro-sheeted dyke transition zone of ODP Hole 1256D (East Pacific Rise, 6°44.163'N, 91°56.061'W). This lithology results from high-temperature metamorphism of previously hydrothermally altered diabases, basalts and/or gabbros; the heat source likely stems from the melt lens located at the top of the magmatic chambers imaged along present-day fast-spreading ridges. This lithology, associated with gabbroic bodies, characterises the transition zone between the sheeted dyke complex and the uppermost gabbroic section and represents the interface between magmatic and hydrothermal convecting systems in an oceanic crust formed at fast-spreading ridges. Samples acquired during IODP Exp. 335 show a particularly high degree of recrystallisation and are characterised by the absence of hydrous phases like amphibole, suggesting very high-T metamorphism. The Beerbachites mineral chemical characteristics are rather homogeneous compared to gabbros or dolerite from the sheeted dyke but pyroxenes Mg#, Ti, Al and Cr contents as well as the anorthite content of plagioclase are closer to gabbro than dolerite. This similarity may be explained by two hypothesis: either beerbachites in Hole 1256D are metamorphosed gabbros, or they underwent a melt-rock reaction process with the gabbros parental magma and were re-equilibrated at high temperature until their mineral composition become similar to that of gabbros. The gabbro-sheeted dyke transition zone in the Oman ophiolite is also outlined by the presence of high grade metamorphic rocks. Fine grained granulites and amphibolites that may be derived from the transformation of altered sheeted dyke diabases are in direct contact with fresh gabbroic and troctolitic bodies which are themselves cross-cut by dolerite dykes. The observation of textures show that high-T recrystallisation occurred in the fine grained

  13. Late Quaternary changes in surface productivity and oxygen minimum zone (OMZ) in the northwestern Arabian Sea: Micropaleontologic and sedimentary record at ODP site 728A

    Indian Academy of Sciences (India)

    Ajai K Rai; S S Das

    2011-02-01

    Changes in the abundance of selected planktic foraminiferal species and some sedimentological parameters at ODP site 728A were examined to understand the fluctuations in the surface productivity and deep sea oxygenation in the NW Arabian Sea during last ∼540 kyr. The increased relative abundances of high fertility taxa, i.e., Globigerinita glutinata and Globigerina bulloides mainly during interglacial intervals indicate intense upwelling. Strong SW summer monsoon probably increased the upwelling in the western Arabian Sea during interglacial intervals and caused high surface productivities due to the lateral transport of eutrophic waters. Most of the glacial periods (i.e., MIS 2, 4, 6, 8 and 12) are characterized by higher relative abundances of Neogloboquadrina pachyderma and Neogloboquadrina dutertrei associated with Globigerinoides ruber. The more stratified condition and deep mixed layer due to increased NE winter monsoon are mainly responsible for the higher relative abundances of N. pachyderma during glacial periods. Some of the glacial intervals (i.e., MIS 6 and 8) are also characterized by pteropod spikes reflecting deepening of aragonite compensation depth (ACD) and relatively less intense oxygen minimum zone (OMZ) in this region due to deep sea mixing and thermocline ventilation, and relatively less intense surface productivity during winter monsoon. The interglacial periods are largely devoid of pteropod shells indicating more aragonite dissolution due to increased intensity of OMZ in the northwestern Arabian Sea. In general, the interglacial periods are characterized by low sediment accumulation rates than the glacial intervals. On an average, the total biogenic carbonate percentages were higher during interglacial and during periods of higher surface productivity. Most terrigenous material was trapped on shelf during intervals of high sea level stands of interglacial, whereas more erosion of shelf increased the sedimentation rates during glacial

  14. Effect of greenhouse gas emissions on stratospheric ozone depletion

    OpenAIRE

    Velders GJM; LLO

    1997-01-01

    The depletion of the ozone layer is caused mainly by the increase in emissions of chlorine- and bromine-containing compounds like CFCs, halons, carbon tetrachloride, methyl chloroform and methyl bromide. Emissions of greenhouse gases can affect the depletion of the ozone layer through atmospheric interaction. We studied the interactions in the atmosphere between the greenhouse effect and stratospheric ozone depletion from the point of view of past and future emissions of the anthropogenic com...

  15. Effect of greenhouse gas emissions on stratospheric ozone depletion

    OpenAIRE

    Velders GJM; LLO

    1997-01-01

    The depletion of the ozone layer is caused mainly by the increase in emissions of chlorine- and bromine-containing compounds like CFCs, halons, carbon tetrachloride, methyl chloroform and methyl bromide. Emissions of greenhouse gases can affect the depletion of the ozone layer through atmospheric interaction. We studied the interactions in the atmosphere between the greenhouse effect and stratospheric ozone depletion from the point of view of past and future emissions of the anthropogenic com...

  16. A Novel Depletion-Mode MOS Gated Emitter Shorted Thyristor

    Institute of Scientific and Technical Information of China (English)

    张鹤鸣; 戴显英; 张义门; 马晓华; 林大松

    2000-01-01

    A Novel MOS-gated thyristor, depletion-mode MOS gated emitter shorted thyristor (DMST),and its two structures are proposed. In DMST,the channel of depletion-mode MOS makes the thyristor emitter-based junction inherently short. The operation of the device is controlled by the interruption and recovery of the depletion-mode MOS P channel. The perfect properties have been demonstrated by 2-D numerical simulations and the tests on the fabricated chips.

  17. The Acasta Gneisses revisited: Evidence for an early depleted mantle

    Science.gov (United States)

    Scherer, E. E.; Sprung, P.; Bleeker, W.; Mezger, K.

    2010-12-01

    The oldest known mineral samples crystallized on the Earth are the up to 4.4 Ga zircon grains from the Jack Hills, Australia [e.g., 1,2]. Zircon, which is datable by U-Pb, contains ca. 1 wt% Hf, and has very low Lu/Hf, is well suited to recording the initial 176Hf/177Hf of its parent magma. It has therefore been widely used to track Earth’s crust-mantle differentiation over time and to estimate the relative amounts of juvenile and recycled components that contributed to Archean and Hadean crust. [e.g., 3,4,5,6]. Zircon studies may be subject to sampling bias, however: Juvenile mafic magmas are likely to stem from depleted sources, but are less likely to crystallize zircon. Processes such as host-rock metamorphism, remelting, weathering of the host rock, and sedimentary transport of grains may have further biased the zircon population. Metamict grains or those with high aspect ratios are likely to be destroyed by these processes, potentially biasing the zircon Hf record toward enriched compositions such that the degree of mantle depletion remains poorly defined before 4 Ga. In addition, incorrect age assignments to Hf analyses result in spurious initial ɛHf values. Here, we attempt to overcome these issues by investigating the bulk rock Lu-Hf and Sm-Nd systematics of some of the oldest rocks on Earth, the Acasta Gneisses (Northwest Territories, Canada). Earlier studies showed that zircon grains in these gneisses tend to come from enriched sources [e.g, 3,7,8] and are thus of little use for directly tracking the degree of mantle depletion. Furthermore, the gneisses themselves have been multiply metamorphosed and are often affected by mixing: The banded gneisses in particular comprise several magmatic precursor rocks of different age that have been repeatedly folded into each other. This promted questions of whether zircon ages should be used in the calculation of bulk rock initial epsilon Nd, and whether linear trends on Sm-Nd isochron represented meaningful

  18. Mantle depletion and metasomatism recorded in orthopyroxene in highly depleted peridotites

    DEFF Research Database (Denmark)

    Scott, James; Liu, Jingao; Pearson, D. Graham;

    2016-01-01

    Although trace element concentrations in clinopyroxene serve as a useful tool for assessing the depletion and enrichment history of mantle peridotites, this is not applicable for peridotites in which the clinopyroxene component has been consumed (~ 25% partial melting). Orthopyroxene persists.......6), high spinel Cr# (commonly > 45) and low orthopyroxene Al2O3 (generally compositions shows that all samples, even the most refractory, have undergone metasomatism by small volume light rare earth element-bearing agents. Measured...

  19. No Evidence of the Ego-Depletion Effect across Task Characteristics and Individual Differences: A Pre-Registered Study.

    Science.gov (United States)

    Lurquin, John H; Michaelson, Laura E; Barker, Jane E; Gustavson, Daniel E; von Bastian, Claudia C; Carruth, Nicholas P; Miyake, Akira

    2016-01-01

    Ego-depletion, a psychological phenomenon in which participants are less able to engage in self-control after prior exertion of self-control, has become widely popular in the scientific community as well as in the media. However, considerable debate exists among researchers as to the nature of the ego-depletion effect, and growing evidence suggests the effect may not be as strong or robust as the extant literature suggests. We examined the robustness of the ego-depletion effect and aimed to maximize the likelihood of detecting the effect by using one of the most widely used depletion tasks (video-viewing attention control task) and by considering task characteristics and individual differences that potentially moderate the effect. We also sought to make our research plan transparent by pre-registering our hypotheses, procedure, and planned analyses prior to data collection. Contrary to the ego-depletion hypothesis, participants in the depletion condition did not perform worse than control participants on the subsequent self-control task, even after considering moderator variables. These findings add to a growing body of evidence suggesting ego-depletion is not a reliable phenomenon, though more research is needed that uses large sample sizes, considers moderator variables, and pre-registers prior to data collection.

  20. Precious Metals in Automotive Technology: An Unsolvable Depletion Problem?

    Directory of Open Access Journals (Sweden)

    Ugo Bardi

    2014-04-01

    Full Text Available Since the second half of the 20th century, various devices have been developed in order to reduce the emissions of harmful substances at the exhaust pipe of combustion engines. In the automotive field, the most diffuse and best known device of this kind is the “three way” catalytic converter for engines using the Otto cycle designed to abate the emissions of carbon monoxide, nitrogen oxides and unburnt hydrocarbons. These catalytic converters can function only by means of precious metals (mainly platinum, rhodium and palladium which exist in a limited supply in economically exploitable ores. The recent increase in prices of all mineral commodities is already making these converters significantly expensive and it is not impossible that the progressive depletion of precious metals will make them too expensive for the market of private cars. The present paper examines how this potential scarcity could affect the technology of road transportation worldwide. We argue that the supply of precious metals for automotive converters is not at risk in the short term, but that in the future it will not be possible to continue using this technology as a result of increasing prices generated by progressive depletion. Mitigation methods such as reducing the amounts of precious metals in catalysts, or recycling them can help but cannot be considered as a definitive solution. We argue that precious metal scarcity is a critical factor that may determine the future development of road transportation in the world. As the problem is basically unsolvable in the long run, we must explore new technologies for road transportation and we conclude that it is likely that the clean engine of the future will be electric and powered by batteries.

  1. The TESS camera: modeling and measurements with deep depletion devices

    Science.gov (United States)

    Woods, Deborah F.; Vanderspek, Roland; MacDonald, Robert; Morgan, Edward; Villasenor, Joel; Thayer, Carolyn; Burke, Barry; Chesbrough, Christian; Chrisp, Michael; Clark, Kristin; Furesz, Gabor; Gonzales, Alexandria; Nguyen, Tam; Prigozhin, Gregory; Primeau, Brian; Ricker, George; Sauerwein, Timothy; Suntharalingam, Vyshnavi

    2016-07-01

    The Transiting Exoplanet Survey Satellite, a NASA Explorer-class mission in development, will discover planets around nearby stars, most notably Earth-like planets with potential for follow up characterization. The all-sky survey requires a suite of four wide field-of-view cameras with sensitivity across a broad spectrum. Deep depletion CCDs with a silicon layer of 100 μm thickness serve as the camera detectors, providing enhanced performance in the red wavelengths for sensitivity to cooler stars. The performance of the camera is critical for the mission objectives, with both the optical system and the CCD detectors contributing to the realized image quality. Expectations for image quality are studied using a combination of optical ray tracing in Zemax and simulations in Matlab to account for the interaction of the incoming photons with the 100 μm silicon layer. The simulations include a probabilistic model to determine the depth of travel in the silicon before the photons are converted to photo-electrons, and a Monte Carlo approach to charge diffusion. The charge diffusion model varies with the remaining depth for the photo-electron to traverse and the strength of the intermediate electric field. The simulations are compared with laboratory measurements acquired by an engineering unit camera with the TESS optical design and deep depletion CCDs. In this paper we describe the performance simulations and the corresponding measurements taken with the engineering unit camera, and discuss where the models agree well in predicted trends and where there are differences compared to observations.

  2. Regret causes ego-depletion and finding benefits in the regrettable events alleviates ego-depletion.

    Science.gov (United States)

    Gao, Hongmei; Zhang, Yan; Wang, Fang; Xu, Yan; Hong, Ying-Yi; Jiang, Jiang

    2014-01-01

    This study tested the hypotheses that experiencing regret would result in ego-depletion, while finding benefits (i.e., "silver linings") in the regret-eliciting events counteracted the ego-depletion effect. Using a modified gambling paradigm (Experiments 1, 2, and 4) and a retrospective method (Experiments 3 and 5), five experiments were conducted to induce regret. Results revealed that experiencing regret undermined performance on subsequent tasks, including a paper-and-pencil calculation task (Experiment 1), a Stroop task (Experiment 2), and a mental arithmetic task (Experiment 3). Furthermore, finding benefits in the regret-eliciting events improved subsequent performance (Experiments 4 and 5), and this improvement was mediated by participants' perceived vitality (Experiment 4). This study extended the depletion model of self-regulation by considering emotions with self-conscious components (in our case, regret). Moreover, it provided a comprehensive understanding of how people felt and performed after experiencing regret and after finding benefits in the events that caused the regret.

  3. If ego depletion cannot be studied using identical tasks, it is not ego depletion.

    Science.gov (United States)

    Lange, Florian

    2015-01-01

    The hypothesis that human self-control capacities are fueled by glucose has been challenged on multiple grounds. A recent study by Lange and Eggert adds to this criticism by presenting two powerful but unsuccessful attempts to replicate the effect of sugar drinks on ego depletion. The dual-task paradigms employed in these experiments have been criticized for involving identical self-control tasks, a methodology that has been argued to reduce participants' willingness to exert self-control. The present article addresses this criticism by demonstrating that there is no indication to believe that the study of glucose effects on ego depletion should be restricted to paradigms using dissimilar acts of self-control. Failures to observe such effects in paradigms involving identical tasks pose a serious problem to the proposal that self-control exhaustion might be reversed by rinsing or ingesting glucose. In combination with analyses of statistical credibility, the experiments by Lange and Eggert suggest that the influence of sugar on ego depletion has been systematically overestimated.

  4. Entropic depletion in colloidal suspensions and polymer liquids: role of nanoparticle surface topography.

    Science.gov (United States)

    Banerjee, Debapriya; Yang, Jian; Schweizer, Kenneth S

    2015-12-21

    We employ a hybrid Monte Carlo plus integral equation theory approach to study how dense fluids of small nanoparticles or polymer chains mediate entropic depletion interactions between topographically rough particles where all interaction potentials are hard core repulsion. The corrugated particle surfaces are composed of densely packed beads which present variable degrees of controlled topographic roughness and free volume associated with their geometric crevices. This pure entropy problem is characterized by competing ideal translational and (favorable and unfavorable) excess entropic contributions. Surface roughness generically reduces particle depletion aggregation relative to the smooth hard sphere case. However, the competition between ideal and excess packing entropy effects in the bulk, near the particle surface and in the crevices, results in a non-monotonic variation of the particle-monomer packing correlation function as a function of the two dimensionless length scale ratios that quantify the effective surface roughness. As a result, the inter-particle potential of mean force (PMF), second virial coefficient, and spinodal miscibility volume fraction vary non-monotonically with the surface bead to monomer diameter and particle core to surface bead diameter ratios. A miscibility window is predicted corresponding to an optimum degree of surface roughness that completely destroys depletion attraction resulting in a repulsive PMF. Variation of the (dense) matrix packing fraction can enhance or suppress particle miscibility depending upon the amount of surface roughness. Connecting the monomers into polymer chains destabilizes the system via enhanced contact depletion attraction, but the non-monotonic variations with surface roughness metrics persist.

  5. Teratogenicity of depleted uranium aerosols: A review from an epidemiological perspective

    Directory of Open Access Journals (Sweden)

    Panikkar Bindu

    2005-08-01

    Full Text Available Abstract Background Depleted uranium is being used increasingly often as a component of munitions in military conflicts. Military personnel, civilians and the DU munitions producers are being exposed to the DU aerosols that are generated. Methods We reviewed toxicological data on both natural and depleted uranium. We included peer reviewed studies and gray literature on birth malformations due to natural and depleted uranium. Our approach was to assess the "weight of evidence" with respect to teratogenicity of depleted uranium. Results Animal studies firmly support the possibility that DU is a teratogen. While the detailed pathways by which environmental DU can be internalized and reach reproductive cells are not yet fully elucidated, again, the evidence supports plausibility. To date, human epidemiological data include case examples, disease registry records, a case-control study and prospective longitudinal studies. Discussion The two most significant challenges to establishing a causal pathway between (human parental DU exposure and the birth of offspring with defects are: i distinguishing the role of DU from that of exposure to other potential teratogens; ii documentation on the individual level of extent of parental DU exposure. Studies that use biomarkers, none yet reported, can help address the latter challenge. Thoughtful triangulation of the results of multiple studies (epidemiological and other of DU teratogenicity contributes to disentangling the roles of various potentially teratogenic parental exposures. This paper is just such an endeavor. Conclusion In aggregate the human epidemiological evidence is consistent with increased risk of birth defects in offspring of persons exposed to DU.

  6. Tylosin depletion in edible tissues of turkeys.

    Science.gov (United States)

    Montesissa, C; De Liguoro, M; Santi, A; Capolongo, F; Biancotto, G

    1999-10-01

    The depletion of tylosin residues in edible turkey tissues was followed after 3 days of administration of tylosin tartrate at 500 mg l-1 in drinking water, to 30 turkeys. Immediately after the end of the treatment (day 0) and at day 1, 3, 5 and 10 of withdrawal, six turkeys (three males and three females) per time were sacrificed and samples of edible tissues were collected. Tissue homogenates were extracted, purified and analysed by HPLC according to a method previously published for the analysis of tylosin residues in pig tissues. In all tissues, tylosin residues were already below the detection limits of 50 micrograms kg-1 at time zero. However, in several samples of tissues (skin + fat, liver, kidney, muscle), from the six turkeys sacrificed at that time, one peak corresponding to an unknown tylosin equivalent was detected at measurable concentrations. The identification of this unknown compound was performed by LC-MS/MS analysis of the extracts from incurred samples. The mass fragmentation of the compound was consistent with the structure of tylosin D (the alcoholic derivative of tylosin A), the major metabolite of tylosin previously recovered and identified in tissues and/or excreta from treated chickens, cattle and pigs.

  7. Effect of niobium element on the electrochemical corrosion behavior of depleted uranium

    Science.gov (United States)

    Wu, Yanping; Wu, Quanwen; Zhu, Shengfa; Pu, Zhen; Zhang, Yanzhi; Wang, Qinguo; Lang, Dingmu; Zhang, Yuping

    2016-09-01

    Depleted uranium (DU) has many military and civilian uses. However, its high chemical reactivity limits its application. The effect of Nb content on corrosion behavior of DU is evaluated by scanning Kelvin probe and electrochemical corrosion measurements. The Volta potential value of DU and U-2.5 wt% Nb is about the same level, the Volta potential value of U-5.7 wt% Nb has a rise of 370mVSHE in comparison with DU. The polarization current of U-5.7 wt% Nb alloy is about an order of magnitude of that of DU. The Nb2O5 is the protective layer for the U-Nb alloys. The negative potential of Nb-depleted α phase is the main reason of the poor corrosion resistance of DU and U-2.5 wt% Nb alloy.

  8. Podocyte depletion causes glomerulosclerosis: diphtheria toxin-induced podocyte depletion in rats expressing human diphtheria toxin receptor transgene

    National Research Council Canada - National Science Library

    Wharram, Bryan L; Goyal, Meera; Wiggins, Jocelyn E; Sanden, Silja K; Hussain, Sabiha; Filipiak, Wanda E; Saunders, Thomas L; Dysko, Robert C; Kohno, Kenji; Holzman, Lawrence B; Wiggins, Roger C

    2005-01-01

    .... For determining the causal relationship between podocyte depletion and glomerulosclerosis, a transgenic rat strain in which the human diphtheria toxin receptor is specifically expressed in podocytes was developed...

  9. Transcriptome Analysis of Scrippsiella trochoidea CCMP 3099 Reveals Physiological Changes Related to Nitrate Depletion

    Directory of Open Access Journals (Sweden)

    Joshua Thomas Cooper

    2016-05-01

    Full Text Available Dinoflagellates are a major component of marine phytoplankton and many species are recognized for their ability to produce harmful algal blooms (HABs. Scrippsiella trochoidea is a non-toxic, marine dinoflagellate that can be found in both cold and tropic waters where it is known to produce red tide events. Little is known about the genomic makeup of S. trochoidea and a transcriptome study was conducted to shed light on the biochemical and physiological adaptations related to nutrient depletion. Cultures were grown under N and P limiting conditions and transcriptomes were generated via RNAseq technology. De novo assembly reconstructed 107,415 putative transcripts of which only 41% could be annotated. No significant transcriptomic response was observed in response to initial P depletion, however, a strong transcriptional response to N depletion was detected. Among the down-regulated pathways were those for glutamine/glutamate metabolism as well as urea and nitrate/nitrite transporters. Transcripts for ammonia transporters displayed both up- and down-regulation, perhaps related to a shift to higher affinity transporters. Genes for the utilization of DON compounds were up-regulated. These included transcripts for amino acids transporters, polyamine oxidase, and extracellular proteinase and peptidases. N depletion also triggered down regulation of transcripts related to the production of Photosystems I & II and related proteins. These data are consistent with a metabolic strategy that conserves N, while maximizing sustained metabolism by emphasizing the relative contribution of organic N sources. Surprisingly, the transcriptome also contained transcripts potentially related to secondary metabolite production, including a homolog to the Short Isoform Saxitoxin gene (sxtA from Alexandrium fundyense, which was significantly up-regulated under N-depletion. A total of 113 unique hits to Sxt genes, covering 17 of the 34 genes found in C. raciborskii were

  10. Variation in RNA-Seq transcriptome profiles of peripheral whole blood from healthy individuals with and without globin depletion.

    Directory of Open Access Journals (Sweden)

    Heesun Shin

    Full Text Available BACKGROUND: The molecular profile of circulating blood can reflect physiological and pathological events occurring in other tissues and organs of the body and delivers a comprehensive view of the status of the immune system. Blood has been useful in studying the pathobiology of many diseases. It is accessible and easily collected making it ideally suited to the development of diagnostic biomarker tests. The blood transcriptome has a high complement of globin RNA that could potentially saturate next-generation sequencing platforms, masking lower abundance transcripts. Methods to deplete globin mRNA are available, but their effect has not been comprehensively studied in peripheral whole blood RNA-Seq data. In this study we aimed to assess technical variability associated with globin depletion in addition to assessing general technical variability in RNA-Seq from whole blood derived samples. RESULTS: We compared technical and biological replicates having undergone globin depletion or not and found that the experimental globin depletion protocol employed removed approximately 80% of globin transcripts, improved the correlation of technical replicates, allowed for reliable detection of thousands of additional transcripts and generally increased transcript abundance measures. Differential expression analysis revealed thousands of genes significantly up-regulated as a result of globin depletion. In addition, globin depletion resulted in the down-regulation of genes involved in both iron and zinc metal ion bonding. CONCLUSIONS: Globin depletion appears to meaningfully improve the quality of peripheral whole blood RNA-Seq data, and may improve our ability to detect true biological variation. Some concerns remain, however. Key amongst them the significant reduction in RNA yields following globin depletion. More generally, our investigation of technical and biological variation with and without globin depletion finds that high-throughput sequencing by RNA

  11. Effect of greenhouse gas emissions on stratospheric ozone depletion

    NARCIS (Netherlands)

    Velders GJM; LLO

    1997-01-01

    The depletion of the ozone layer is caused mainly by the increase in emissions of chlorine- and bromine-containing compounds like CFCs, halons, carbon tetrachloride, methyl chloroform and methyl bromide. Emissions of greenhouse gases can affect the depletion of the ozone layer through atmospheric i

  12. Effect of greenhouse gas emissions on stratospheric ozone depletion

    NARCIS (Netherlands)

    Velders GJM; LLO

    1997-01-01

    The depletion of the ozone layer is caused mainly by the increase in emissions of chlorine- and bromine-containing compounds like CFCs, halons, carbon tetrachloride, methyl chloroform and methyl bromide. Emissions of greenhouse gases can affect the depletion of the ozone layer through atmospheric

  13. Ozone depletion during solar proton events in solar cycle 21

    Science.gov (United States)

    Mcpeters, R. D.; Jackman, C. H.

    1985-01-01

    Ozone profile data from the Solar Backscattered Ultraviolet Instrument on Nimbus 7 from 1979 to the present and clear cases of ozone destruction associated with five sudden proton events (SPEs) on June 7, 1979, August 21, 1979, October 13-14, 1981, July 13, 1982, and December 8, 1982 are found. During the SPE on July 13, 1982, the largest of this solar cycle, no depletion at all at 45 km is observed, but there is a 15 percent ozone depletion at 50 km increasing to 27 percent at 55 km, all at a solar zenith angle of 85 deg. A strong variation of the observed depletion with solar zenith angle is found, with maximum depletion occurring at the largest zenith angles (near 85 deg) decreasing to near zero for angles below about 70 deg. The observed depletion is short lived, disappearing within hours of the end of the SPE.

  14. Analysis and Application of Whey Protein Depleted Skim Milk Systems

    DEFF Research Database (Denmark)

    Sørensen, Hanne

    homogenisation (UHPH). The microfiltration will result in a milk fraction more or less depleted from whey protein, and could probably in combination with UHPH treatment contribute to milk fractions and cheeses with novel micro and macrostructures. These novel fractions could be used as new ingredients to improve......-destructive methods for this purpose. A significant changed structure was observed in skim milk depleted or partly depleted for whey protein, acidified and UHPH treated. Some of the properties of the UHPH treated skim milk depleted from whey protein observed in this study support the idea, that UHPH treatment has...... this. LF-NMR relaxation were utilised to obtain information about the water mobility (relaxation time), in diluted skim milk systems depleted from whey protein. Obtained results indicate that measuring relaxation times with LF-NMR could be difficult to utilize, since no clear relationship between...

  15. Barium depletion study on impregnated cathodes and lifetime prediction

    Energy Technology Data Exchange (ETDEWEB)

    Roquais, J.M.; Poret, F.; Doze, R. le; Ricaud, J.L.; Monterrin, A.; Steinbrunn, A

    2003-06-15

    In the thermionic cathodes used in cathode ray-tubes (CRTs), barium is the key element for the electronic emission. In the case of the dispenser cathodes made of a porous tungsten pellet impregnated with Ba, Ca aluminates, the evaporation of Ba determines the cathode lifetime with respect to emission performance in the CRT. The Ba evaporation results in progressive depletion of the impregnating material inside the pellet. In the present work, the Ba depletion with time has been extensively characterized over a large range of cathode temperature. Calculations using the depletion data allowed modeling of the depletion as a function of key parameters. The link between measured depletion and emission in tubes has been established, from which an end-of-life criterion was deduced. Taking modeling into account, predicting accelerated life-tests were performed using high-density maximum emission current (MIK)

  16. The effect of ego depletion on sprint start reaction time.

    Science.gov (United States)

    Englert, Chris; Bertrams, Alex

    2014-10-01

    In the current study, we consider that optimal sprint start performance requires the self-control of responses. Therefore, start performance should depend on athletes' self-control strength. We assumed that momentary depletion of self-control strength (ego depletion) would either speed up or slow down the initiation of a sprint start, where an initiation that was sped up would carry the increased risk of a false start. Applying a mixed between- (depletion vs. nondepletion) and within- (before vs. after manipulation of depletion) subjects design, we tested the start reaction times of 37 sport students. We found that participants' start reaction times decelerated after finishing a depleting task, whereas it remained constant in the nondepletion condition. These results indicate that sprint start performance can be impaired by unrelated preceding actions that lower momentary self-control strength. We discuss practical implications in terms of optimizing sprint starts and related overall sprint performance.

  17. From the lavas to the gabbros: 1.25 km of geochemical characterization of upper oceanic crust at ODP/IODP Site 1256, eastern equatorial Pacific

    Science.gov (United States)

    Höfig, Tobias W.; Geldmacher, Jörg; Hoernle, Kaj; Hauff, Folkmar; Duggen, Svend; Garbe-Schönberg, Dieter

    2014-12-01

    Here we present trace element and Sr-Nd-Hf-Pb (double spike) isotopic data covering the entire igneous section of oceanic crust drilled at Ocean Drilling Program (ODP)/Integrated Ocean Drilling Program (IODP) Site 1256 on the Cocos Plate. The penetrated interval extends from the upper lavas through the sheeted dike complex to the gabbroic plutonic rocks, formed during superfast spreading at the mid-Miocene equatorial East Pacific Rise. The data are used to characterize the effects of chemical alteration, resulting from convection of seawater and hydrothermal fluids, on the trace element and isotopic composition of oceanic crust. Compared to normal mid-ocean-ridge basalt, the igneous basement of Site 1256 (Holes 1256C/D) is isotopically slightly enriched but shows only narrow downhole variations in Nd-Hf-Pb isotope ratios: 143Nd/144Nd = 0.513089 ± 0.000028 (2σ), 176Hf/177Hf = 0.283194 ± 0.000033 (2σ), 206Pb/204Pb = 18.61 ± 0.11 (2σ), 207Pb/204Pb = 15.521 ± 0.014 (2σ), 208Pb/204Pb = 38.24 ± 0.15 (2σ). We believe that this minor variability is mainly of primary (magmatic) origin. The Sr isotopic composition shows considerably larger variation and, as expected, serves as sensitive tracer of seawater influence, which is particularly pronounced in the lava-dike transition zone and the sheeted dikes. The seawater influence is most prominent in a highly metal sulfide-enriched breccia layer encountered in the transition zone with 87Sr/86Sr of ~ 0.706, indicating a maximum water-rock mixing ratio of ~ 12. However, compared to the igneous section drilled at Site 504 (Hole 504B), which formed at intermediate, i.e., slower spreading rates at the Galápagos Spreading Center and hosting a much thicker sulfide-rich stockwork zone, the average intensity of water-rock interaction is lower. This is expressed by lesser mobility of base metals, narrower variability of alteration-sensitive incompatible elements, and less radiogenic Sr isotopic compositions on average at Site

  18. Inhibition of autophagy augments apoptosis in human oral squamous cell carcinoma under nutrient depletion.

    Science.gov (United States)

    Jiang, Li-Cheng; Xin, Zhi-Yuan; Deborah, Baremberg; Zhang, Jun-Sheng; Yuan, Dao-Ying; Xu, Kai; Liu, Xian-Bin; Jiang, Hu-Quan; Fan, Qing-Chun; Zhang, Bin; Li, Ke-Yi

    2015-05-01

    There has been little research conducted regarding autophagy in oral squamous cell carcinoma (OSCC). Given the prevalence of oral cancers which are OSCC and the severe side effects of current treatments, there is a pressing need to develop effective alternative therapies. In this study, we have endeavored to explore the biological characteristics of oral squamous cell carcinoma cell line KB cells, in particular with regard to the role played by autophagy in their survival. Autophagy was activated by nutrient depletion via culturing cells in Earle's balanced salts (EBSS) and was measured via indices relating to Beclin 1, microtubule-associated protein light chain 3 (MAPLC3, LC3), p62, and Green fluorescent protein-light chain 3 plasmid transfection (GFP-LC3). Cell death and apoptosis induced by nutrient depletion was measured using both MTT assay and flow cytometry (FCM). Compared to initial levels at 0 h, Beclin 1 density in EBSS-treated cells was found to have increased at 6, 12, and 18 h in a time-dependent manner and was found to have subsequently declined at 24 and 48 h. p62 levels, LC3-II/LC3-I ratio, and GFP-LC3 levels increased at 6, 12, 18, 24, and 48 h in a time-dependent manner. 3-methyladenine (3-MA) was found to inhibit autophagy and the expression of Beclin 1 and significantly enhanced nutrient depletion-induced apoptosis and death. We concluded that nutrient depletion enhances OSCC cell autophagy in time-course patterns and that the inhibition of autophagy augments apoptosis in OSCC cells. We also deduced that Beclin 1 takes part in the development and progression of autophagy, potentially playing an important role in the crosstalk between apoptosis and autophagy in OSCC cells. These findings suggest that nutrient depletion may be an effective way to explore autophagy and that autophagy inhibitors should be investigated as a potential novel agent for the adjuvant treatment of human OSCC.

  19. Methylphenidate blocks effort-induced depletion of regulatory control in healthy volunteers.

    Science.gov (United States)

    Sripada, Chandra; Kessler, Daniel; Jonides, John

    2014-06-01

    A recent wave of studies--more than 100 conducted over the last decade--has shown that exerting effort at controlling impulses or behavioral tendencies leaves a person depleted and less able to engage in subsequent rounds of regulation. Regulatory depletion is thought to play an important role in everyday problems (e.g., excessive spending, overeating) as well as psychiatric conditions, but its neurophysiological basis is poorly understood. Using a placebo-controlled, double-blind design, we demonstrated that the psychostimulant methylphenidate (commonly known as Ritalin), a catecholamine reuptake blocker that increases dopamine and norepinephrine at the synaptic cleft, fully blocks effort-induced depletion of regulatory control. Spectral analysis of trial-by-trial reaction times revealed specificity of methylphenidate effects on regulatory depletion in the slow-4 frequency band. This band is associated with the operation of resting-state brain networks that produce mind wandering, which raises potential connections between our results and recent brain-network-based models of control over attention.

  20. Depletion of alveolar macrophages in CD11c diphtheria toxin receptor mice produces an inflammatory response

    Science.gov (United States)

    Roberts, Lydia M; Ledvina, Hannah E; Tuladhar, Shraddha; Rana, Deepa; Steele, Shaun P; Sempowski, Gregory D; Frelinger, Jeffrey A

    2015-01-01

    Alveolar macrophages play a critical role in initiating the immune response to inhaled pathogens and have been shown to be the first cell type infected following intranasal inoculation with several pathogens, including Francisella tularensis. In an attempt to further dissect the role of alveolar macrophages in the immune response to Francisella, we selectively depleted alveolar macrophages using CD11c.DOG mice. CD11c.DOG mice express the diphtheria toxin receptor (DTR) under control of the full CD11c promoter. Because mice do not express DTR, tissue restricted expression of the primate DTR followed by treatment with diphtheria toxin (DT) has been widely used as a tool in immunology to examine the effect of acute depletion of a specific immune subset following normal development. We successfully depleted alveolar macrophages via intranasal administration of DT. However, alveolar macrophage depletion was accompanied by many other changes to the cellular composition and cytokine/chemokine milieu in the lung that potentially impact innate and adaptive immune responses. Importantly, we observed a transient influx of neutrophils in the lung and spleen. Our experience serves as a cautionary note to other researchers using DTR mice given the complex changes that occur following DT treatment that must be taken into account when analyzing data. PMID:26029367

  1. Simulation of ozone depletion using ambient irradiance supplemented with UV lamps.

    Science.gov (United States)

    Díaz, S; Camilión, C; Escobar, J; Deferrari, G; Roy, S; Lacoste, K; Demers, S; Belzile, C; Ferreyra, G; Gianesella, S; Gosselin, M; Nozais, C; Pelletier, E; Schloss, I; Vernet, M

    2006-01-01

    In studies of the biological effects of UV radiation, ozone depletion can be mimicked by performing the study under ambient conditions and adding radiation with UV-B lamps. We evaluated this methodology at three different locations along a latitudinal gradient: Rimouski (Canada), Ubatuba (Brazil) and Ushuaia (Argentina). Experiments of the effect of potential ozone depletion on marine ecosystems were carried out in large outdoor enclosures (mesocosms). In all locations we simulated irradiances corresponding to 60% ozone depletion, which may produce a 130-1900% increase in 305 nm irradiance at noon, depending on site and season. Supplementation with a fixed percentage of ambient irradiance provides a better simulation of irradiance increase due to ozone depletion than supplementation with a fixed irradiance value, particularly near sunrise and sunset or under cloudy skies. Calculations performed for Ushuaia showed that, on very cloudy days, supplementation by the square-wave method may produce unrealistic irradiances. Differences between the spectra of the calculated supplementing irradiance and the lamp for a given site and date will be a function of the time of day and may become more or less pronounced according to the biological weighting function of the effect under study.

  2. Drought response strategies define the relative contributions of hydraulic dysfunction and carbohydrate depletion during tree mortality.

    Science.gov (United States)

    Mitchell, Patrick J; O'Grady, Anthony P; Tissue, David T; White, Donald A; Ottenschlaeger, Maria L; Pinkard, Elizabeth A

    2013-02-01

    Plant survival during drought requires adequate hydration in living tissues and carbohydrate reserves for maintenance and recovery. We hypothesized that tree growth and hydraulic strategy determines the intensity and duration of the 'physiological drought', thereby affecting the relative contributions of loss of hydraulic function and carbohydrate depletion during mortality. We compared patterns in growth rate, water relations, gas exchange and carbohydrate dynamics in three tree species subjected to prolonged drought. Two Eucalyptus species (E. globulus, E. smithii) exhibited high growth rates and water-use resulting in rapid declines in water status and hydraulic conductance. In contrast, conservative growth and water relations in Pinus radiata resulted in longer periods of negative carbon balance and significant depletion of stored carbohydrates in all organs. The ongoing demand for carbohydrates from sustained respiration highlighted the role that duration of drought plays in facilitating carbohydrate consumption. Two drought strategies were revealed, differentiated by plant regulation of water status: plants maximized gas exchange, but were exposed to low water potentials and rapid hydraulic dysfunction; and tight regulation of gas exchange at the cost of carbohydrate depletion. These findings provide evidence for a relationship between hydraulic regulation of water status and carbohydrate depletion during terminal drought. © 2012 CSIRO. New Phytologist © 2012 New Phytologist Trust.

  3. Comparison of Three Dimensional Partially and Fully Depleted SOI MOSFET Characteristics Using Mathcad

    Directory of Open Access Journals (Sweden)

    Neha Goel

    2016-03-01

    Full Text Available In this Paper, comparison of three Dimensional characteristics between partially and fully depleted Silicon-On-Insulator (SOI MOSFET is presented, this is done through 3D device modeling using mathcad, based on the numerical solution of three dimensional Poisson’s equation. Behavior of Various Parameters like Surface Potential, Threshold Voltage, Electric field and Drain current are presented in this paper.

  4. Development of a Novel Depleted Uranium Treatment Process at Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Gates-Anderson, D; Bowers, J; Laue, C; Fitch, T

    2007-01-22

    A three-stage process was developed at Lawrence Livermore National Laboratory to treat potentially pyrophoric depleted uranium metal wastes. The three-stage process includes waste sorting/rinsing, acid dissolution of the waste metal with a hydrochloric and phosphoric acid solution, and solidification of the neutralized residuals from the second stage with clay. The final product is a solid waste form that can be transported to and disposed of at a permitted low-level radioactive waste disposal site.

  5. CD4+ T cell depletion during all stages of HIV disease occurs predominantly in the gastrointestinal tract.

    Science.gov (United States)

    Brenchley, Jason M; Schacker, Timothy W; Ruff, Laura E; Price, David A; Taylor, Jodie H; Beilman, Gregory J; Nguyen, Phuong L; Khoruts, Alexander; Larson, Matthew; Haase, Ashley T; Douek, Daniel C

    2004-09-20

    The mechanisms underlying CD4(+) T cell depletion in human immunodeficiency virus (HIV) infection are not well understood. Comparative studies of lymphoid tissues, where the vast majority of T cells reside, and peripheral blood can potentially illuminate the pathogenesis of HIV-associated disease. Here, we studied the effect of HIV infection on the activation and depletion of defined subsets of CD4(+) and CD8(+) T cells in the blood, gastrointestinal (GI) tract, and lymph node (LN). We also measured HIV-specific T cell frequencies in LNs and blood, and LN collagen deposition to define architectural changes associated with chronic inflammation. The major findings to emerge are the following: the GI tract has the most substantial CD4(+) T cell depletion at all stages of HIV disease; this depletion occurs preferentially within CCR5(+) CD4(+) T cells; HIV-associated immune activation results in abnormal accumulation of effector-type T cells within LNs; HIV-specific T cells in LNs do not account for all effector T cells; and T cell activation in LNs is associated with abnormal collagen deposition. Taken together, these findings define the nature and extent of CD4(+) T cell depletion in lymphoid tissue and point to mechanisms of profound depletion of specific T cell subsets related to elimination of CCR5(+) CD4(+) T cell targets and disruption of T cell homeostasis that accompanies chronic immune activation.

  6. Depleted Uranium Hexafluoride Management Program. The technology assessment report for the long-term management of depleted uranium hexafluoride. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Zoller, J.N.; Rosen, R.S.; Holliday, M.A. [and others

    1995-06-30

    With the publication of a Request for Recommendations and Advance Notice of Intent in the November 10, 1994 Federal Register, the Department of Energy initiated a program to assess alternative strategies for the long-term management or use of depleted uranium hexafluoride. This Request was made to help ensure that, by seeking as many recommendations as possible, Department management considers reasonable options in the long-range management strategy. The Depleted Uranium Hexafluoride Management Program consists of three major program elements: Engineering Analysis, Cost Analysis, and an Environmental Impact Statement. This Technology Assessment Report is the first part of the Engineering Analysis Project, and assesses recommendations from interested persons, industry, and Government agencies for potential uses for the depleted uranium hexafluoride stored at the gaseous diffusion plants in Paducah, Kentucky, and Portsmouth, Ohio, and at the Oak Ridge Reservation in Tennessee. Technologies that could facilitate the long-term management of this material are also assessed. The purpose of the Technology Assessment Report is to present the results of the evaluation of these recommendations. Department management will decide which recommendations will receive further study and evaluation.

  7. Depleted Uranium Hexafluoride Management Program. The technology assessment report for the long-term management of depleted uranium hexafluoride. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Zoller, J.N.; Rosen, R.S.; Holliday, M.A. [and others

    1995-06-30

    With the publication of a Request for Recommendations and Advance Notice of Intent in the November 10, 1994 Federal Register, the Department of Energy initiated a program to assess alternative strategies for the long-term management or use of depleted uranium hexafluoride. This Request was made to help ensure that, by seeking as many recommendations as possible, Department management considers reasonable options in the long-range management strategy. The Depleted Uranium Hexafluoride Management Program consists of three major program elements: Engineering Analysis, Cost Analysis, and an Environmental Impact Statement. This Technology Assessment Report is the first part of the Engineering Analysis Project, and assesses recommendations from interested persons, industry, and Government agencies for potential uses for the depleted uranium hexafluoride stored at the gaseous diffusion plants in Paducah, Kentucky, and Portsmouth, Ohio, and at the Oak Ridge Reservation in Tennessee. Technologies that could facilitate the long-term management of this material are also assessed. The purpose of the Technology Assessment Report is to present the results of the evaluation of these recommendations. Department management will decide which recommendations will receive further study and evaluation. These Appendices contain the Federal Register Notice, comments on evaluation factors, independent technical reviewers resumes, independent technical reviewers manual, and technology information packages.

  8. Linkages between ozone depleting substances, tropospheric oxidation and aerosols

    Directory of Open Access Journals (Sweden)

    A. Voulgarakis

    2012-09-01

    Full Text Available Coupling between the stratosphere and the troposphere allows changes in stratospheric ozone abundances to affect tropospheric chemistry. Large-scale effects from such changes on chemically produced tropospheric aerosols have not been systematically examined in past studies. We use a composition-climate model to investigate potential past and future impacts of changes in stratospheric Ozone Depleting Substances (ODS on tropospheric oxidants and sulfate aerosols. In most experiments, we find significant responses in tropospheric photolysis and oxidants, with small but significant effects on methane radiative forcing. The response of sulfate aerosols is sizeable when examining the effect of increasing future nitrous oxide (N2O emissions. We also find that without the regulation of chlorofluorocarbons (CFCs through the Montreal Protocol, sulfate aerosols could have increased by 2050 by a comparable amount to the decreases predicted due to relatively stringent sulfur emissions controls. The historical radiative forcing of CFCs through their indirect effects on methane (−22.6 mW m−2 and sulfate aerosols (−3.0 mW m−2 discussed here is non-negligible when compared to known historical CFC forcing. Our results stress the importance of accounting for stratosphere-troposphere, gas-aerosol and composition-climate interactions when investigating the effects of changing emissions on atmospheric composition and climate.

  9. Extracellular N-acetylaspartate depletion in traumatic brain injury.

    Science.gov (United States)

    Belli, Antonio; Sen, Jon; Petzold, Axel; Russo, Salvatore; Kitchen, Neil; Smith, Martin; Tavazzi, Barbara; Vagnozzi, Roberto; Signoretti, Stefano; Amorini, Angela Maria; Bellia, Francesco; Lazzarino, Giuseppe

    2006-02-01

    N-Acetylaspartate (NAA) is almost exclusively localized in neurons in the adult brain and is present in high concentration in the CNS. It can be measured by proton magnetic resonance spectroscopy and is seen as a marker of neuronal damage and death. NMR spectroscopy and animal models have shown NAA depletion to occur in various types of chronic and acute brain injury. We investigated 19 patients with traumatic brain injury (TBI). Microdialysis was utilized to recover NAA, lactate, pyruvate, glycerol and glutamate, at 12-h intervals. These markers were correlated with survival and a 6-month Glasgow Outcome Score. Eleven patients died and eight survived. A linear mixed model analysis showed a significant effect of outcome and of the interaction between time of injury and outcome on NAA levels (p = 0.009 and p = 0.004, respectively). Overall, extracellular NAA was 34% lower in non-survivors. A significant non-recoverable fall was observed in this group from day 4 onwards, with a concomitant rise in lactate-pyruvate ratio and glycerol. These results suggest that mitochondrial dysfunction is a significant contributor to poor outcome following TBI and propose extracellular NAA as a potential marker for monitoring interventions aimed at preserving mitochondrial function.

  10. High CO depletion in southern infrared-dark clouds

    CERN Document Server

    Fontani, F; Beltran, M T; Dodson, R; Rioja, M; Brand, J; Caselli, P; Cesaroni, R

    2012-01-01

    Infrared-dark high-mass clumps are among the most promising objects to study the initial conditions of the formation process of high-mass stars and rich stellar clusters. In this work, we have observed the (3-2) rotational transition of C18O with the APEX telescope, and the (1,1) and (2,2) inversion transitions of NH3 with the Australia Telescope Compact Array in 21 infrared-dark clouds already mapped in the 1.2 mm continuum, with the aim of measuring basic chemical and physical parameters such as the CO depletion factor (fD), the gas kinetic temperature and the gas mass. In particular, the C18O (3-2) line allows us to derive fD in gas at densities higher than that traced by the (1-0) and (2-1) lines, typically used in previous works. We have detected NH3 and C18O in all targets. The clumps possess mass, H2 column and surface densities consistent with being potentially the birthplace of high-mass stars. We have measured fD in between 5 and 78, with a mean value of 32 and a median of 29. These values are, to o...

  11. Consumer depletion alters seagrass resistance to an invasive macroalga.

    Science.gov (United States)

    Caronni, Sarah; Calabretti, Chiara; Delaria, Maria Anna; Bernardi, Giuseppe; Navone, Augusto; Occhipinti-Ambrogi, Anna; Panzalis, Pieraugusto; Ceccherelli, Giulia

    2015-01-01

    Few field studies have investigated how changes at one trophic level can affect the invasibility of other trophic levels. We examined the hypothesis that the spread of an introduced alga in disturbed seagrass beds with degraded canopies depends on the depletion of large consumers. We mimicked the degradation of seagrass canopies by clipping shoot density and reducing leaf length, simulating natural and anthropogenic stressors such as fish overgrazing and water quality. Caulerpa racemosa was transplanted into each plot and large consumers were excluded from half of them using cages. Potential cage artifacts were assessed by measuring irradiance, scouring by leaf movement, water flow, and sedimentation. Algal invasion of the seagrass bed differed based on the size of consumers. The alga had higher cover and size under the cages, where the seagrass was characterized by reduced shoot density and canopy height. Furthermore, canopy height had a significant effect depending on canopy density. The alteration of seagrass canopies increased the spread of C. racemosa only when large consumers were absent. Our results suggest that protecting declining habitats and/or restoring fish populations will limit the expansion of C. racemosa. Because MPAs also enhance the abundance and size of fish consuming seagrass they can indirectly promote algal invasion. The effects of MPAs on invasive species are context dependent and require balancing opposing forces, such as the conservation of seagrass canopy structure and the protection of fish grazing the seagrass.

  12. Large attractive depletion interactions in soft repulsive-sphere binary mixtures.

    Science.gov (United States)

    Cinacchi, Giorgio; Martínez-Ratón, Yuri; Mederos, Luis; Navascués, Guillermo; Tani, Alessandro; Velasco, Enrique

    2007-12-07

    We consider binary mixtures of soft repulsive spherical particles and calculate the depletion interaction between two big spheres mediated by the fluid of small spheres, using different theoretical and simulation methods. The validity of the theoretical approach, a virial expansion in terms of the density of the small spheres, is checked against simulation results. Attention is given to the approach toward the hard-sphere limit and to the effect of density and temperature on the strength of the depletion potential. Our results indicate, surprisingly, that even a modest degree of softness in the pair potential governing the direct interactions between the particles may lead to a significantly more attractive total effective potential for the big spheres than in the hard-sphere case. This might lead to significant differences in phase behavior, structure, and dynamics of a binary mixture of soft repulsive spheres. In particular, a perturbative scheme is applied to predict the phase diagram of an effective system of big spheres interacting via depletion forces for a size ratio of small and big spheres of 0.2; this diagram includes the usual fluid-solid transition but, in the soft-sphere case, the metastable fluid-fluid transition, which is probably absent in hard-sphere mixtures, is close to being stable with respect to direct fluid-solid coexistence. From these results, the interesting possibility arises that, for sufficiently soft repulsive particles, this phase transition could become stable. Possible implications for the phase behavior of real colloidal dispersions are discussed.

  13. Novel basophil- or eosinophil-depleted mouse models for functional analyses of allergic inflammation.

    Science.gov (United States)

    Matsuoka, Kunie; Shitara, Hiroshi; Taya, Choji; Kohno, Kenji; Kikkawa, Yoshiaki; Yonekawa, Hiromichi

    2013-01-01

    Basophils and eosinophils play important roles in various host defense mechanisms but also act as harmful effectors in allergic disorders. We generated novel basophil- and eosinophil-depletion mouse models by introducing the human diphtheria toxin (DT) receptor gene under the control of the mouse CD203c and the eosinophil peroxidase promoter, respectively, to study the critical roles of these cells in the immunological response. These mice exhibited selective depletion of the target cells upon DT administration. In the basophil-depletion model, DT administration attenuated a drop in body temperature in IgG-mediated systemic anaphylaxis in a dose-dependent manner and almost completely abolished the development of ear swelling in IgE-mediated chronic allergic inflammation (IgE-CAI), a typical skin swelling reaction with massive eosinophil infiltration. In contrast, in the eosinophil-depletion model, DT administration ameliorated the ear swelling in IgE-CAI whether DT was administered before, simultaneously, or after, antigen challenge, with significantly lower numbers of eosinophils infiltrating into the swelling site. These results confirm that basophils and eosinophils act as the initiator and the effector, respectively, in IgE-CAI. In addition, antibody array analysis suggested that eotaxin-2 is a principal chemokine that attracts proinflammatory cells, leading to chronic allergic inflammation. Thus, the two mouse models established in this study are potentially useful and powerful tools for studying the in vivo roles of basophils and eosinophils. The combination of basophil- and eosinophil-depletion mouse models provides a new approach to understanding the complicated mechanism of allergic inflammation in conditions such as atopic dermatitis and asthma.

  14. Novel basophil- or eosinophil-depleted mouse models for functional analyses of allergic inflammation.

    Directory of Open Access Journals (Sweden)

    Kunie Matsuoka

    Full Text Available Basophils and eosinophils play important roles in various host defense mechanisms but also act as harmful effectors in allergic disorders. We generated novel basophil- and eosinophil-depletion mouse models by introducing the human diphtheria toxin (DT receptor gene under the control of the mouse CD203c and the eosinophil peroxidase promoter, respectively, to study the critical roles of these cells in the immunological response. These mice exhibited selective depletion of the target cells upon DT administration. In the basophil-depletion model, DT administration attenuated a drop in body temperature in IgG-mediated systemic anaphylaxis in a dose-dependent manner and almost completely abolished the development of ear swelling in IgE-mediated chronic allergic inflammation (IgE-CAI, a typical skin swelling reaction with massive eosinophil infiltration. In contrast, in the eosinophil-depletion model, DT administration ameliorated the ear swelling in IgE-CAI whether DT was administered before, simultaneously, or after, antigen challenge, with significantly lower numbers of eosinophils infiltrating into the swelling site. These results confirm that basophils and eosinophils act as the initiator and the effector, respectively, in IgE-CAI. In addition, antibody array analysis suggested that eotaxin-2 is a principal chemokine that attracts proinflammatory cells, leading to chronic allergic inflammation. Thus, the two mouse models established in this study are potentially useful and powerful tools for studying the in vivo roles of basophils and eosinophils. The combination of basophil- and eosinophil-depletion mouse models provides a new approach to understanding the complicated mechanism of allergic inflammation in conditions such as atopic dermatitis and asthma.

  15. Partial regulatory T cell depletion prior to schistosomiasis vaccination does not enhance the protection.

    Directory of Open Access Journals (Sweden)

    Xuefeng Wang

    Full Text Available CD4(+CD25(+ regulatory T cells (Tregs do not only influence self-antigen specific immune responses, but also dampen the protective effect induced by a number of vaccines. The impact of CD4(+CD25(+ Tregs on vaccines against schistosomiasis, a neglected tropical disease that is a major public health concern, however, has not been examined. In this study, a DNA vaccine encoding a 26 kDa glutathione S-transferase of Schistosoma japonicum (pVAX1-Sj26GST was constructed and its potential effects were evaluated by depleting CD25(+ cells prior to pVAX1-Sj26GST immunization. This work shows that removal of CD25(+ cells prior to immunization with the pVAX1-Sj26GST schistosomiasis DNA vaccine significantly increases the proliferation of splenocytes and IgG levels. However, CD25(+ cell-depleted mice immunized with pVAX1-Sj26GST show no improved protection against S. japonicum. Furthermore, depletion of CD25(+ cells causes an increase in both pro-inflammatory cytokines (e.g. IFN-γ, GM-CSF and IL-4 and an anti-inflammatory cytokine (e.g. IL-10, with CD4(+CD25(- T cells being one of the major sources of both IFN-γ and IL-10. These findings indicate that partial CD25(+ cell depletion fails to enhance the effectiveness of the schistosome vaccine, possibly due to IL-10 production by CD4(+CD25(- T cells, or other cell types, after CD25(+ cell depletion during vaccination.

  16. AFSC/REFM: Pacific cod Localized Depletion Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data from Localized Depletion study for Pacific cod 2001-2005. Study was conducted using cod pot gear to measure localized abundance of Pacific cod inside and...

  17. Groundwater depletion in the United States (1900-2008)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A natural consequence of groundwater withdrawals is the removal of water from subsurface storage, but the overall rates and magnitude of groundwater depletion in the...

  18. Prediction Method of Safety Mud Density in Depleted Oilfields

    Directory of Open Access Journals (Sweden)

    Yuan Jun-Liang

    2013-04-01

    Full Text Available At present, many oilfields were placed in the middle and late development period and the reservoir pressure depleted usually, resulting in more serious differential pressure sticking and drilling mud leakage both in the reservoir and cap rock. In view of this situation, a systematic prediction method of safety mud density in depleted oilfields was established. The influence of reservoir depletion on stress and strength in reservoir and cap formation were both studied and taken into the prediction of safety mud density. The research showed that the risk of differential pressure sticking and drilling mud leakage in reservoir and cap formation were both increased and they were the main prevention object in depleted oilfields drilling. The research results were used to guide the practice drilling work, the whole progress gone smoothly.

  19. Hyperspectral stimulated emission depletion microscopy and methods of use thereof

    Science.gov (United States)

    Timlin, Jerilyn A; Aaron, Jesse S

    2014-04-01

    A hyperspectral stimulated emission depletion ("STED") microscope system for high-resolution imaging of samples labeled with multiple fluorophores (e.g., two to ten fluorophores). The hyperspectral STED microscope includes a light source, optical systems configured for generating an excitation light beam and a depletion light beam, optical systems configured for focusing the excitation and depletion light beams on a sample, and systems for collecting and processing data generated by interaction of the excitation and depletion light beams with the sample. Hyperspectral STED data may be analyzed using multivariate curve resolution analysis techniques to deconvolute emission from the multiple fluorophores. The hyperspectral STED microscope described herein can be used for multi-color, subdiffraction imaging of samples (e.g., materials and biological materials) and for analyzing a tissue by Forster Resonance Energy Transfer ("FRET").

  20. STRATOSPHERIC OZONE DEPLETION: A FOCUS ON EPA'S RESEARCH

    Science.gov (United States)

    In September of 1987 the United States, along with 26 other countries, signed a landmark treaty to limit and subsequently, through revisions, phase out the production of all significant ozone depleting substances. Many researchers suspected that these chemicals, especially chl...

  1. Depletion of microglia exacerbates postischemic inflammation and brain injury

    National Research Council Canada - National Science Library

    Jin, Wei-Na; Shi, Samuel Xiang-Yu; Li, Zhiguo; Li, Minshu; Wood, Kristofer; Gonzales, Rayna J; Liu, Qiang

    2017-01-01

    ...). Although depletion of microglia has been linked to worse stroke outcomes, it remains unclear to what extent and by what mechanisms activated microglia influence ischemia-induced inflammation and injury in the brain...

  2. Background suppression in fluorescence nanoscopy with stimulated emission double depletion

    Science.gov (United States)

    Gao, Peng; Prunsche, Benedikt; Zhou, Lu; Nienhaus, Karin; Nienhaus, G. Ulrich

    2017-01-01

    Stimulated emission depletion (STED) fluorescence nanoscopy is a powerful super-resolution imaging technique based on the confinement of fluorescence emission to the central subregion of an observation volume through de-excitation of fluorophores in the periphery via stimulated emission. Here, we introduce stimulated emission double depletion (STEDD) as a method to selectively remove artificial background intensity. In this approach, a first, conventional STED pulse is followed by a second, delayed Gaussian STED pulse that specifically depletes the central region, thus leaving only background. Thanks to time-resolved detection we can remove this background intensity voxel by voxel by taking the weighted difference of photons collected before and after the second STED pulse. STEDD thus yields background-suppressed super-resolved images as well as STED-based fluorescence correlation spectroscopy data. Furthermore, the proposed method is also beneficial when considering lower-power, less redshifted depletion pulses.

  3. Asymmetric spindle pole formation in CPAP-depleted mitotic cells.

    Science.gov (United States)

    Lee, Miseon; Chang, Jaerak; Chang, Sunghoe; Lee, Kyung S; Rhee, Kunsoo

    2014-02-21

    CPAP is an essential component for centriole formation. Here, we report that CPAP is also critical for symmetric spindle pole formation during mitosis. We observed that pericentriolar material between the mitotic spindle poles were asymmetrically distributed in CPAP-depleted cells even with intact numbers of centrioles. The length of procentrioles was slightly reduced by CPAP depletion, but the length of mother centrioles was not affected. Surprisingly, the young mother centrioles of the CPAP-depleted cells are not fully matured, as evidenced by the absence of distal and subdistal appendage proteins. We propose that the selective absence of centriolar appendages at the young mother centrioles may be responsible for asymmetric spindle pole formation in CPAP-depleted cells. Our results suggest that the neural stem cells with CPAP mutations might form asymmetric spindle poles, which results in premature initiation of differentiation.

  4. Individual differences in dopamine level modulate the ego depletion effect.

    Science.gov (United States)

    Dang, Junhua; Xiao, Shanshan; Liu, Ying; Jiang, Yumeng; Mao, Lihua

    2016-01-01

    Initial exertion of self-control impairs subsequent self-regulatory performance, which is referred to as the ego depletion effect. The current study examined how individual differences in dopamine level, as indexed by eye blink rate (EBR), would moderate ego depletion. An inverted-U-shaped relationship between EBR and subsequent self-regulatory performance was found when participants initially engaged in self-control but such relationship was absent in the control condition where there was no initial exertion, suggesting individuals with a medium dopamine level may be protected from the typical ego depletion effect. These findings are consistent with a cognitive explanation which considers ego depletion as a phenomenon similar to "switch costs" that would be neutralized by factors promoting flexible switching.

  5. Net depletion determination for Hankin Wetland Development Project

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This memorandum contains the analysis and the data used to produce the net depletion that would occur as a result of the Hankin Wetland Development Project.

  6. Adding trend data to Depletion-Based Stock Reduction Analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Bayesian model of Depletion-Based Stock Reduction Analysis (DB-SRA), informed by a time series of abundance indexes, was developed, using the Sampling Importance...

  7. Hydroxide depletion in dilute supernates stored in waste tanks

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.T.

    1985-10-10

    Free hydroxide ion in dilute supernates are depleted by reaction with atmospheric carbon dioxide to form bicarbonate and carbonate species and by reaction with acidic compounds formed by the radiolytic decomposition of tetraphenylborate salts. A model of the kinetics and thermodynamics of absorption of carbon dioxide in the waste tanks has been developed. Forecasts of the rate of hydroxide depletion and the requirements for sodium hydroxide to maintain technical standards have been made for the washed sludge and washed precipitate storage tanks. Hydroxide depletion is predicted to have a minimal impact on sludge processing operations. However, in-tank precipitation and downstream DWPF operations are predicted to be significantly affected by hydroxide depletion in Tank 49H. The installation of a carbon dioxide scrubber on Tank 49H may be justified in view of the decrease in alkali content and variation in the melter feed.

  8. Conditional depletion of nuclear proteins by the Anchor Away system.

    Science.gov (United States)

    Fan, Xiaochun; Geisberg, Joseph V; Wong, Koon Ho; Jin, Yi

    2011-01-01

    Nuclear proteins play key roles in the regulation of many important cellular processes. In Saccharomyces cerevisiae, many genes encoding nuclear proteins are essential. This unit describes a method termed Anchor Away that can be used to conditionally and rapidly deplete nuclear proteins of interest. It involves conditional export of the protein of interest out of the nucleus and its subsequent sequestration in the cytoplasm. This method can be used to simultaneously deplete multiple proteins from the nucleus.

  9. Cholinergic depletion and basal forebrain volume in primary progressive aphasia

    Directory of Open Access Journals (Sweden)

    Jolien Schaeverbeke

    2017-01-01

    In the PPA group, only LV cases showed decreases in AChE activity levels compared to controls. Surprisingly, a substantial number of SV cases showed significant AChE activity increases compared to controls. BF volume did not correlate with AChE activity levels in PPA. To conclude, in our sample of PPA patients, LV but not SV was associated with cholinergic depletion. BF atrophy in PPA does not imply cholinergic depletion.

  10. Inositol depletion restores vesicle transport in yeast phospholipid flippase mutants.

    Science.gov (United States)

    Yamagami, Kanako; Yamamoto, Takaharu; Sakai, Shota; Mioka, Tetsuo; Sano, Takamitsu; Igarashi, Yasuyuki; Tanaka, Kazuma

    2015-01-01

    In eukaryotic cells, type 4 P-type ATPases function as phospholipid flippases, which translocate phospholipids from the exoplasmic leaflet to the cytoplasmic leaflet of the lipid bilayer. Flippases function in the formation of transport vesicles, but the mechanism remains unknown. Here, we isolate an arrestin-related trafficking adaptor, ART5, as a multicopy suppressor of the growth and endocytic recycling defects of flippase mutants in budding yeast. Consistent with a previous report that Art5p downregulates the inositol transporter Itr1p by endocytosis, we found that flippase mutations were also suppressed by the disruption of ITR1, as well as by depletion of inositol from the culture medium. Interestingly, inositol depletion suppressed the defects in all five flippase mutants. Inositol depletion also partially restored the formation of secretory vesicles in a flippase mutant. Inositol depletion caused changes in lipid composition, including a decrease in phosphatidylinositol and an increase in phosphatidylserine. A reduction in phosphatidylinositol levels caused by partially depleting the phosphatidylinositol synthase Pis1p also suppressed a flippase mutation. These results suggest that inositol depletion changes the lipid composition of the endosomal/TGN membranes, which results in vesicle formation from these membranes in the absence of flippases.

  11. The Optimal Depletion of Exhaustible Resource under Different Commitment

    Institute of Scientific and Technical Information of China (English)

    Zhou Wei; Wu Kangping

    2012-01-01

    There are few papers in the literature focusing on the issue of the optimal depletion of exhaustible resources in the framework of variable time preference. This paper attempts to analyze the pure consumption of exhaustible resource under hy- perbolic time preference, and to discuss the optimal depletion rate and the effect of the protection of the exhaustible resource under different commitment abilities. The results of model show that the case of the hyperbolic discount with the full commitment of the govemment is equivalent to the case of constant discount of the social planner problem. In that case, the optimal depletion rate and the initial consumption of exhaustible resource are the slowest. On the contrary, they are the highest and the myopic behaviors lead to excessive consumption of exhaustible resources inevitably without commitment. Otherwise, in the case of partial commit- ment, the results are between the cases of full commitment and of no commitment. Therefore, with the hyperbolic time preference, the optimal depletion rate of resource depends on the commitment ability. Higher commitment ability leads to lower effective rate of time preference, and consequently, lower depletion rate and lower initial depletion value. The improvement of commitment ability can decrease the impatience and myopia behaviors, and contribute to the protection of the exhaustible resources.

  12. Tumor eradication after cyclophosphamide depends on concurrent depletion of regulatory T cells: a role for cycling TNFR2-expressing effector-suppressor T cells in limiting effective chemotherapy.

    Science.gov (United States)

    van der Most, Robbert G; Currie, Andrew J; Mahendran, Sathish; Prosser, Amy; Darabi, Anna; Robinson, Bruce W S; Nowak, Anna K; Lake, Richard A

    2009-08-01

    Tumor cell death potentially engages with the immune system. However, the efficacy of anti-tumor chemotherapy may be limited by tumor-driven immunosuppression, e.g., through CD25+ regulatory T cells. We addressed this question in a mouse model of mesothelioma by depleting or reconstituting CD25+ regulatory T cells in combination with two different chemotherapeutic drugs. We found that the efficacy of cyclophosphamide to eradicate established tumors, which has been linked to regulatory T cell depletion, was negated by adoptive transfer of CD25+ regulatory T cells. Analysis of post-chemotherapy regulatory T cell populations revealed that cyclophosphamide depleted cycling (Ki-67(hi)) T cells, including foxp3+ regulatory CD4+ T cells. Ki-67(hi) CD4+ T cells expressed increased levels of two markers, TNFR2 and ICOS, that have been associated with a maximally suppressive phenotype according to recently published studies. This suggest that cyclophosphamide depletes a population of maximally suppressive regulatory T cells, which may explain its superior anti-tumor efficacy in our model. Our data suggest that regulatory T cell depletion could be used to improve the efficacy of anti-cancer chemotherapy regimens. Indeed, we observed that the drug gemcitabine, which does not deplete cycling regulatory T cells, eradicates established tumors in mice only when CD25+ CD4+ T cells are concurrently depleted. Cyclophosphamide could be used to achieve regulatory T cell depletion in combination with chemotherapy.

  13. 77 FR 53236 - Proposed International Isotopes Fluorine Extraction Process and Depleted Uranium Deconversion...

    Science.gov (United States)

    2012-08-31

    ... COMMISSION Proposed International Isotopes Fluorine Extraction Process and Depleted Uranium Deconversion... International Isotopes Fluorine Extraction Process and Depleted Uranium Deconversion Plant (INIS) in Lea County... construction, operation, and decommissioning of a fluorine extraction and depleted uranium...

  14. The dynamics of the stratospheric polar vortex and its relation to springtime ozone depletions

    Science.gov (United States)

    Schoeberl, Mark R.; Hartmann, Dennis L.

    1991-01-01

    Recent aircraft observations have determined the structure of polar vortices during winter and their relationship to polar ozone depletions, based on high dynamical isolation and the extremely low temperatures required for stratospheric cloud formation. The aircraft data reveal large gradients of potential vorticity and concentrations of conservative trace species at the transition from high-latitude to polar air, implying that the inward mixing of heat and constituents is strongly inhibited, and that the perturbed polar stratospheric chemistry associated with the ozone hole is isolated from the rest of the stratosphere until the vortex breaks up in late spring. It is therefore the overall polar vortex which limits the annual polar ozone depletions' maximum area-coverage.

  15. NOx Catalyzed Pathway of Stratospheric Ozone Depletion: A Coupled Cluster Investigation.

    Science.gov (United States)

    Dutta, Achintya Kumar; Vaval, Nayana; Pal, Sourav

    2012-06-12

    We report a theoretical investigation on the NOx catalyzed pathways of stratospheric ozone depletion using highly accurate coupled cluster methods. These catalytic reactions represent a great challenge to state-of-the-art ab initio methods, while their mechanisms remain unclear to both experimentalists and theoreticians. In this work, we have used the so-called "gold standard of quantum chemistry," the CCSD(T) method, to identify the saddle points on NOx-based reaction pathways of ozone hole formation. Energies of the saddle points are calculated using the multireference variants of coupled cluster methods. The calculated activation energies and rate constants show good agreement with available experimental results. Tropospheric precursors to stratospheric NOx radicals have been identified, and their potential importance in stratospheric chemistry has been discussed. Our calculations resolve previous conflicts between ab initio and experimental results for a trans nitro peroxide intermediate, in the NOx catalyzed pathway of ozone depletion.

  16. A robust TEC depletion detector algorithm for satellite based navigation in Indian zone and depletion analysis for GAGAN

    Science.gov (United States)

    Dashora, Nirvikar

    2012-07-01

    Equatorial plasma bubble (EPB) and associated plasma irregularities are known to cause severe scintillation for the satellite signals and produce range errors, which eventually result either in loss of lock of the signal or in random fluctuation in TEC, respectively, affecting precise positioning and navigation solutions. The EPBs manifest as sudden reduction in line of sight TEC, which are more often called TEC depletions, and are spread over thousands of km in meridional direction and a few hundred km in zonal direction. They change shape and size while drifting from one longitude to another in nighttime ionosphere. For a satellite based navigation system, like GAGAN in India that depends upon (i) multiple satellites (i.e. GPS) (ii) multiple ground reference stations and (iii) a near real time data processing, such EPBs are of grave concern. A TEC model generally provides a near real-time grid based ionospheric vertical errors (GIVEs) over hypothetically spread 5x5 degree latitude-longitude grid points. But, on night when a TEC depletion occurs in a given longitude sector, it is almost impossible for any system to give a forecast of GIVEs. If loss-of-lock events occur due to scintillation, there is no way to improve the situation. But, when large and random depletions in TEC occur with scintillations and without loss-of-lock, it affects low latitude TEC in two ways. (a) Multiple satellites show depleted TEC which may be very different from model-TEC values and hence the GIVE would be incorrect over various grid points (ii) the user may be affected by depletions which are not sampled by reference stations and hence interpolated GIVE within one square would be grossly erroneous. The most general solution (and the far most difficult as well) is having advance knowledge of spatio-temporal occurrence and precise magnitude of such depletions. While forecasting TEC depletions in spatio-temporal domain are a scientific challenge (as we show below), operational systems

  17. Ego depletion decreases trust in economic decision making

    Science.gov (United States)

    Ainsworth, Sarah E.; Baumeister, Roy F.; Vohs, Kathleen D.; Ariely, Dan

    2014-01-01

    Three experiments tested the effects of ego depletion on economic decision making. Participants completed a task either requiring self-control or not. Then participants learned about the trust game, in which senders are given an initial allocation of $10 to split between themselves and another person, the receiver. The receiver receives triple the amount given and can send any, all, or none of the tripled money back to the sender. Participants were assigned the role of the sender and decided how to split the initial allocation. Giving less money, and therefore not trusting the receiver, is the safe, less risky response. Participants who had exerted self-control and were depleted gave the receiver less money than those in the non-depletion condition (Experiment 1). This effect was replicated and moderated in two additional experiments. Depletion again led to lower amounts given (less trust), but primarily among participants who were told they would never meet the receiver (Experiment 2) or who were given no information about how similar they were to the receiver (Experiment 3). Amounts given did not differ for depleted and non-depleted participants who either expected to meet the receiver (Experiment 2) or were led to believe that they were very similar to the receiver (Experiment 3). Decreased trust among depleted participants was strongest among neurotics. These results imply that self-control facilitates behavioral trust, especially when no other cues signal decreased social risk in trusting, such as if an actual or possible relationship with the receiver were suggested. PMID:25013237

  18. Depletion of macrophages in mice results in higher dengue virus titers and highlights the role of macrophages for virus control

    NARCIS (Netherlands)

    Fink, K.; Ng, C.; Nkenfou, C.; Vasudevan, S.G.; Rooijen, van N.; Schul, W.

    2009-01-01

    Monocytes and macrophages are target cells for dengue infection. Besides their potential role for virus replication, activated monocytes/macrophages produce cytokines that may be critical for dengue pathology. To study the in vivo role of monocytes and macrophages for virus replication, we depleted

  19. The corrosion of depleted uranium in terrestrial and marine environments.

    Science.gov (United States)

    Toque, C; Milodowski, A E; Baker, A C

    2014-02-01

    Depleted Uranium alloyed with titanium is used in armour penetrating munitions that have been fired in a number of conflict zones and testing ranges including the UK ranges at Kirkcudbright and Eskmeals. The study presented here evaluates the corrosion of DU alloy cylinders in soil on these two UK ranges and in the adjacent marine environment of the Solway Firth. The estimated mean initial corrosion rates and times for complete corrosion range from 0.13 to 1.9 g cm(-2) y(-1) and 2.5-48 years respectively depending on the particular physical and geochemical environment. The marine environment at the experimental site was very turbulent. This may have caused the scouring of corrosion products and given rise to a different geochemical environment from that which could be easily duplicated in laboratory experiments. The rate of mass loss was found to vary through time in one soil environment and this is hypothesised to be due to pitting increasing the surface area, followed by a build up of corrosion products inhibiting further corrosion. This indicates that early time measurements of mass loss or corrosion rate may be poor indicators of late time corrosion behaviour, potentially giving rise to incorrect estimates of time to complete corrosion. The DU alloy placed in apparently the same geochemical environment, for the same period of time, can experience very different amounts of corrosion and mass loss, indicating that even small variations in the corrosion environment can have a significant effect. These effects are more significant than other experimental errors and variations in initial surface area.

  20. Ideas and perspectives: Southwestern tropical Atlantic coral growth response to atmospheric circulation changes induced by ozone depletion in Antarctica

    Science.gov (United States)

    Evangelista, Heitor; Wainer, Ilana; Sifeddine, Abdelfettah; Corrège, Thierry; Cordeiro, Renato C.; Lamounier, Saulo; Godiva, Daniely; Shen, Chuan-Chou; Le Cornec, Florence; Turcq, Bruno; Lazareth, Claire E.; Hu, Ching-Yi

    2016-04-01

    Recent Southern Hemisphere (SH) atmospheric circulation, predominantly driven by stratospheric ozone depletion over Antarctica, has caused changes in climate across the extratropics. Here, we present evidence that the Brazilian coast (southwestern Atlantic) may have been impacted from both wind and sea-surface temperature changes derived from this process. Skeleton analysis of massive coral species living in shallow waters off Brazil are very sensitive to air-sea interactions, and seem to record this impact. Growth rates of Brazilian corals show a trend reversal that fits the ozone depletion evolution, confirming that ozone impacts are far reaching and potentially affect coastal ecosystems in tropical environments.

  1. Examining depletion theories under conditions of within-task transfer.

    Science.gov (United States)

    Brewer, Gene A; Lau, Kevin K H; Wingert, Kimberly M; Ball, B Hunter; Blais, Chris

    2017-07-01

    In everyday life, mental fatigue can be detrimental across many domains including driving, learning, and working. Given the importance of understanding and accounting for the deleterious effects of mental fatigue on behavior, a growing body of literature has studied the role of motivational and executive control processes in mental fatigue. In typical laboratory paradigms, participants complete a task that places demand on these self-control processes and are later given a subsequent task. Generally speaking, decrements to subsequent task performance are taken as evidence that the initial task created mental fatigue through the continued engagement of motivational and executive functions. Several models have been developed to account for negative transfer resulting from this "ego depletion." In the current study, we provide a brief literature review, specify current theoretical approaches to ego-depletion, and report an empirical test of current models of depletion. Across 4 experiments we found minimal evidence for executive control depletion along with strong evidence for motivation mediated ego depletion. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  2. Depletion of microglia exacerbates postischemic inflammation and brain injury.

    Science.gov (United States)

    Jin, Wei-Na; Shi, Samuel Xiang-Yu; Li, Zhiguo; Li, Minshu; Wood, Kristofer; Gonzales, Rayna J; Liu, Qiang

    2017-06-01

    Brain ischemia elicits microglial activation and microglia survival depend on signaling through colony-stimulating factor 1 receptor (CSF1R). Although depletion of microglia has been linked to worse stroke outcomes, it remains unclear to what extent and by what mechanisms activated microglia influence ischemia-induced inflammation and injury in the brain. Using a mouse model of transient focal cerebral ischemia and reperfusion, we demonstrated that depletion of microglia via administration of the dual CSF1R/c-Kit inhibitor PLX3397 exacerbates neurodeficits and brain infarction. Depletion of microglia augmented the production of inflammatory mediators, leukocyte infiltration, and cell death during brain ischemia. Of note, microglial depletion-induced exacerbation of stroke severity did not solely depend on lymphocytes and monocytes. Importantly, depletion of microglia dramatically augmented the production of inflammatory mediators by astrocytes after brain ischemia . In vitro studies reveal that microglia restricted ischemia-induced astrocyte response and provided neuroprotective effects. Our findings suggest that neuroprotective effects of microglia may result, in part, from its inhibitory action on astrocyte response after ischemia.

  3. The Physical Origin of Long Gas Depletion Times in Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Semenov, Vadim [Chicago U., Astron. Astrophys. Ctr.; Kravtsov, Andrey [Chicago U., KICP; Gnedin, Nickolay [Fermilab

    2017-04-13

    We present a model that elucidates why gas depletion times in galaxies are long compared to the time scales of the processes driving the evolution of the interstellar medium. We show that global depletion times are not set by any "bottleneck" in the process of gas evolution towards the star-forming state. Instead, depletion times are long because star-forming gas converts only a small fraction of its mass into stars before it is dispersed by dynamical and feedback processes. Thus, complete depletion requires that gas transitions between star-forming and non-star-forming states multiple times. Our model does not rely on the assumption of equilibrium and can be used to interpret trends of depletion times with the properties of observed galaxies and the parameters of star formation and feedback recipes in galaxy simulations. In particular, the model explains the mechanism by which feedback self-regulates star formation rate in simulations and makes it insensitive to the local star formation efficiency. We illustrate our model using the results of an isolated $L_*$-sized disk galaxy simulation that reproduces the observed Kennicutt-Schmidt relation for both molecular and atomic gas. Interestingly, the relation for molecular gas is close to linear on kiloparsec scales, even though a non-linear relation is adopted in simulation cells. This difference is due to stellar feedback, which breaks the self-similar scaling of the gas density PDF with the average gas surface density.

  4. OZONE DEPLETING SUBSTANCES ELIMINATION MANAGEMENT: THE SUCCESS STORY OF MACEDONIA

    Directory of Open Access Journals (Sweden)

    Margarita Matlievska

    2013-04-01

    Full Text Available Man, with its activities, produces and uses substances that have negative impact on the environment and the human health, and can cause an economic damage. Consequently, they have a great impact on quality of life. Among the most harmful chemicals are Ozone Depleting Substances that are subject of regulation with international conventions. This Paper supports the fact that each country has to undertake national efforts for ozone depleting substances reduction and elimination. In that respect, the general objective of the Paper is to present the Macedonian unique experience regarding its efforts to reduce or eliminate these substances. The following two aspects were subject to the research: national legislation which regulates the Ozone Depleting Substances import and export as well as the implementation of the projects that resulted with the elimination of Ozone Depleting Substances quantities in the period 1995 – 2010. The research outcomes confirm the starting research hypothesis i.e. that with adequately created and implemented national action, the amount of Ozone Depleting Substances consumption can dramatically fall.

  5. Global Depletion of Groundwater Resources: Past and Future Analyses

    Science.gov (United States)

    Bierkens, M. F.; de Graaf, I. E. M.; Van Beek, L. P.; Wada, Y.

    2014-12-01

    Globally, about 17% of the crops are irrigated, yet irrigation accounts for 40% of the global food production. As more than 40% of irrigation water comes from groundwater, groundwater abstraction rates are large and exceed natural recharge rates in many regions of the world, thus leading to groundwater depletion. In this paper we provide an overview of recent research on global groundwater depletion. We start with presenting various estimates of global groundwater depletion, both from flux based as well as volume based methods. We also present estimates of the contribution of non-renewable groundwater to irrigation water consumption and how this contribution developed during the last 50 years. Next, using a flux based method, we provide projections of groundwater depletion for the coming century under various socio-economic and climate scenarios. As groundwater depletion contributes to sea-level rise, we also provide estimates of this contribution from the past as well as for future scenarios. Finally, we show recent results of groundwater level changes and change in river flow as a result of global groundwater abstractions as obtained from a global groundwater flow model.

  6. Recovery of the Ozone Layer: The Ozone Depleting Gas Index

    Science.gov (United States)

    Hofmann, David J.; Montzka, Stephen A.

    2009-01-01

    The stratospheric ozone layer, through absorption of solar ultraviolet radiation, protects all biological systems on Earth. In response to concerns over the depletion of the global ozone layer, the U.S. Clean Air Act as amended in 1990 mandates that NASA and NOAA monitor stratospheric ozone and ozone-depleting substances. This information is critical for assessing whether the Montreal Protocol on Substances That Deplete the Ozone Layer, an international treaty that entered into force in 1989 to protect the ozone layer, is having its intended effect of mitigating increases in harmful ultraviolet radiation. To provide the information necessary to satisfy this congressional mandate, both NASA and NOAA have instituted and maintained global monitoring programs to keep track of ozone-depleting gases as well as ozone itself. While data collected for the past 30 years have been used extensively in international assessments of ozone layer depletion science, the language of scientists often eludes the average citizen who has a considerable interest in the health of Earth's protective ultraviolet radiation shield. Are the ozone-destroying chemicals declining in the atmosphere? When will these chemicals decline to pre-ozone hole levels so that the Antarctic ozone hole might disappear? Will this timing be different in the stratosphere above midlatitudes?

  7. Self-regulatory depletion increases emotional reactivity in the amygdala.

    Science.gov (United States)

    Wagner, Dylan D; Heatherton, Todd F

    2013-04-01

    The ability to self-regulate can become impaired when people are required to engage in successive acts of effortful self-control, even when self-control occurs in different domains. Here, we used functional neuroimaging to test whether engaging in effortful inhibition in the cognitive domain would lead to putative dysfunction in the emotional domain. Forty-eight participants viewed images of emotional scenes during functional magnetic resonance imaging in two sessions that were separated by a challenging attention control task that required effortful inhibition (depletion group) or not (control group). Compared to the control group, depleted participants showed increased activity in the left amygdala to negative but not to positive or neutral scenes. Moreover, whereas the control group showed reduced amygdala activity to all scene types (i.e. habituation), the depletion group showed increased amygdala activity relative to their pre-depletion baseline; however this was only significant for negative scenes. Finally, depleted participants showed reduced functional connectivity between the left amygdala and ventromedial prefrontal cortex during negative scene processing. These findings demonstrate that consuming self-regulatory resources leads to an exaggerated neural response to emotional material that appears specific to negatively valenced stimuli and further suggests a failure to recruit top-down prefrontal regions involved in emotion regulation.

  8. A depleted, not ideally chondritic bulk Earth: The explosive-volcanic basalt loss hypothesis

    Science.gov (United States)

    Warren, Paul H.

    2008-04-01

    It has long been customary to assume that in the bulk composition of the Earth, all refractory-lithophile elements (including major oxides Al 2O 3 and CaO, all of the REE, and the heat-producing elements Th and U) occur in chondritic, bulk solar system, proportion to one another. Recently, however, Nd-isotopic studies (most notably Boyet M. and Carlson R. W. (2006) A new geochemical model for the Earth's mantle inferred from 146Sm- 142Nd systematics. Earth Planet. Sci. Lett.250, 254-268) have suggested that at least the outer portion of the planet features a Nd/Sm ratio depleted to ˜0.93 times the chondritic ratio. The primary reaction to this type of evidence has been to invoke a "hidden" reservoir of enriched matter, sequestered into the deepest mantle as a consequence of primordial differentiation. I propose a hypothesis that potentially explains the evidence for Nd/Sm depletion in a very different way. Among the handful of major types of differentiated asteroidal meteorites, two (ureilites and aubrites) are ultramafic restites so consistently devoid of plagioclase that meteoriticists were once mystified as to how all the complementary plagioclase-rich matter (basalt) was lost. The explanation appears to be basalt loss by graphite-fueled explosive volcanism on roughly 100-km sized planetesimals; with the dispersiveness of the process dramatically enhanced, relative to terrestrial experience, because the pyroclastic gases expand into vacuous space (Wilson L. and Keil K. (1991) Consequences of explosive eruptions on small Solar System bodies: the case of the missing basalts on the aubrite parent body. Earth Planet. Sci. Lett.104, 505-512). By analogy with lunar pyroclastic products, the typical size of pyroclastic melt/glass droplets under these circumstances will be roughly 0.1 mm. Once separated from an asteroidal or planetesimal gravitational field, droplets of this size will generally spiral toward the Sun, rather than reaccrete, because drag forces such the

  9. Design and construction of Keda Space Plasma Experiment (KSPEX) for the investigation of the boundary layer processes of ionospheric depletions.

    Science.gov (United States)

    Liu, Yu; Zhang, Zhongkai; Lei, Jiuhou; Cao, Jinxiang; Yu, Pengcheng; Zhang, Xiao; Xu, Liang; Zhao, Yaodong

    2016-09-01

    In this work, the design and construction of the Keda Space Plasma EXperiment (KSPEX), which aims to study the boundary layer processes of ionospheric depletions, are described in detail. The device is composed of three stainless-steel sections: two source chambers at both ends and an experimental chamber in the center. KSPEX is a steady state experimental device, in which hot filament arrays are used to produce plasmas in the two sources. A Macor-mesh design is adopted to adjust the plasma density and potential difference between the two plasmas, which creates a boundary layer with a controllable electron density gradient and inhomogeneous radial electric field. In addition, attachment chemicals can be released into the plasmas through a tailor-made needle valve which leads to the generation of negative ions plasmas. Ionospheric depletions can be modeled and simulated using KSPEX, and many micro-physical processes of the formation and evolution of an ionospheric depletion can be experimentally studied.

  10. Development of a Depleted Monolithic CMOS Sensor in a 150 nm CMOS Technology for the ATLAS Inner Tracker Upgrade

    CERN Document Server

    Wang, T.

    2017-01-01

    The recent R&D focus on CMOS sensors with charge collection in a depleted zone has opened new perspectives for CMOS sensors as fast and radiation hard pixel devices. These sensors, labelled as depleted CMOS sensors (DMAPS), have already shown promising performance as feasible candidates for the ATLAS Inner Tracker (ITk) upgrade, possibly replacing the current passive sensors. A further step to exploit the potential of DMAPS is to investigate the suitability of equipping the outer layers of the ATLAS ITk upgrade with fully monolithic CMOS sensors. This paper presents the development of a depleted monolithic CMOS pixel sensor designed in the LFoundry 150 nm CMOS technology, with the focus on design details and simulation results.

  11. Design and construction of Keda Space Plasma Experiment (KSPEX) for the investigation of the boundary layer processes of ionospheric depletions

    Science.gov (United States)

    Liu, Yu; Zhang, Zhongkai; Lei, Jiuhou; Cao, Jinxiang; Yu, Pengcheng; Zhang, Xiao; Xu, Liang; Zhao, Yaodong

    2016-09-01

    In this work, the design and construction of the Keda Space Plasma EXperiment (KSPEX), which aims to study the boundary layer processes of ionospheric depletions, are described in detail. The device is composed of three stainless-steel sections: two source chambers at both ends and an experimental chamber in the center. KSPEX is a steady state experimental device, in which hot filament arrays are used to produce plasmas in the two sources. A Macor-mesh design is adopted to adjust the plasma density and potential difference between the two plasmas, which creates a boundary layer with a controllable electron density gradient and inhomogeneous radial electric field. In addition, attachment chemicals can be released into the plasmas through a tailor-made needle valve which leads to the generation of negative ions plasmas. Ionospheric depletions can be modeled and simulated using KSPEX, and many micro-physical processes of the formation and evolution of an ionospheric depletion can be experimentally studied.

  12. The depletion of Interleukin-8 causes cell cycle arrest and increases the efficacy of docetaxel in breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Nan [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Chen, Liu-Hua [Department of Minimally Invasive Surgery Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Ye, Run-Yi [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Lin, Ying, E-mail: frostlin@hotmail.com [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China); Wang, Shen-Ming, E-mail: shenmingwang@hotmail.com [Breast Disease Center, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou (China)

    2013-02-15

    Highlights: ► IL-8 depletion affects cell cycle distribution. ► Intrinsic IL-8 mediates breast cancer cell migration and invasion. ► IL-8 siRNA down regulates key factors that control survival and metastatic pathway. ► IL-8 depletion reduces integrin β3 expression. ► IL-8 depletion increases the chemosensitivity to docetaxel. -- Abstract: IL-8 is a multi-functional pro-inflammatory chemokine, which is highly expressed in cancers, such as ER-negative breast cancer. The present study demonstrates the pervasive role of IL-8 in the malignant progression of ER-negative breast cancer. IL-8 siRNA inhibited proliferation and delayed the G1 to S cell cycle progression in MDA-MB-231 and BT549 cells. IL-8 silencing resulted in the upregulation of the CDK inhibitor p27, the downregulation of cyclin D1, and the reduction of phosphorylated-Akt and NF-κB activities. IL-8 depletion also increased the chemosensitivity to docetaxel. These results indicate a role for IL-8 in promoting tumor cell survival and resistance to docetaxel and highlight the potential therapeutic significance of IL-8 depletion in ER-negative breast cancer patients.

  13. Arginine depletion by arginine deiminase does not affect whole protein metabolism or muscle fractional protein synthesis rate in mice.

    Science.gov (United States)

    Marini, Juan C; Didelija, Inka Cajo

    2015-01-01

    Due to the absolute need for arginine that certain cancer cells have, arginine depletion is a therapy in clinical trials to treat several types of cancers. Arginine is an amino acids utilized not only as a precursor for other important molecules, but also for protein synthesis. Because arginine depletion can potentially exacerbate the progressive loss of body weight, and especially lean body mass, in cancer patients we determined the effect of arginine depletion by pegylated arginine deiminase (ADI-PEG 20) on whole body protein synthesis and fractional protein synthesis rate in multiple tissues of mice. ADI-PEG 20 successfully depleted circulating arginine (arginine, whole body protein synthesis and breakdown were maintained in the ADI-PEG 20 treated mice. The fractional protein synthesis rate of muscle was also not affected by arginine depletion. Most tissues (liver, kidney, spleen, heart, lungs, stomach, small and large intestine, pancreas) were able to maintain their fractional protein synthesis rate; however, the fractional protein synthesis rate of brain, thymus and testicles was reduced due to the ADI-PEG 20 treatment. Furthermore, these results were confirmed by the incorporation of ureido [14C]citrulline, which indicate the local conversion into arginine, into protein. In conclusion, the intracellular recycling pathway of citrulline is able to provide enough arginine to maintain protein synthesis rate and prevent the loss of lean body mass and body weight.

  14. Processable high internal phase Pickering emulsions using depletion attraction.

    Science.gov (United States)

    Kim, KyuHan; Kim, Subeen; Ryu, Jiheun; Jeon, Jiyoon; Jang, Se Gyu; Kim, Hyunjun; Gweon, Dae-Gab; Im, Won Bin; Han, Yosep; Kim, Hyunjung; Choi, Siyoung Q

    2017-02-01

    High internal phase emulsions have been widely used as templates for various porous materials, but special strategies are required to form, in particular, particle-covered ones that have been more difficult to obtain. Here, we report a versatile strategy to produce a stable high internal phase Pickering emulsion by exploiting a depletion interaction between an emulsion droplet and a particle using water-soluble polymers as a depletant. This attractive interaction facilitating the adsorption of particles onto the droplet interface and simultaneously suppressing desorption once adsorbed. This technique can be universally applied to nearly any kind of particle to stabilize an interface with the help of various non- or weakly adsorbing polymers as a depletant, which can be solidified to provide porous materials for many applications.

  15. Processable high internal phase Pickering emulsions using depletion attraction

    Science.gov (United States)

    Kim, Kyuhan; Kim, Subeen; Ryu, Jiheun; Jeon, Jiyoon; Jang, Se Gyu; Kim, Hyunjun; Gweon, Dae-Gab; Im, Won Bin; Han, Yosep; Kim, Hyunjung; Choi, Siyoung Q.

    2017-02-01

    High internal phase emulsions have been widely used as templates for various porous materials, but special strategies are required to form, in particular, particle-covered ones that have been more difficult to obtain. Here, we report a versatile strategy to produce a stable high internal phase Pickering emulsion by exploiting a depletion interaction between an emulsion droplet and a particle using water-soluble polymers as a depletant. This attractive interaction facilitating the adsorption of particles onto the droplet interface and simultaneously suppressing desorption once adsorbed. This technique can be universally applied to nearly any kind of particle to stabilize an interface with the help of various non- or weakly adsorbing polymers as a depletant, which can be solidified to provide porous materials for many applications.

  16. Observations of ozone depletion associated with solar proton events

    Science.gov (United States)

    Mcpeters, R. D.; Jackman, C. H.; Stassinopoulos, E. G.

    1981-01-01

    Ozone profiles from the solar proton events (SPE) of January and September 1971 and August 1972 were obtained after the backscattered ultraviolet (BUV) measured radiances were corrected for the direct effects of protons on the instrument. The SPE of August 1972 produced an ozone depletion of 15% at 42 km that persisted for one month in both northern and southern polar regions. This long recovery time indicates that NO(x) was produced in a quantity sufficient to alter the ozone chemistry. The two SPE in 1971 were of moderate size, but produced ozone depletions of 10-30% at 50 km with a 36 hour recovery time. This rapid recovery is consistent with the assumption that HO(x) is responsible for altering the ozone chemistry (Weeks et al., 1972). The magnitude of the observed depletion, however, exceeds that predicted by the chemical models.

  17. Processable high internal phase Pickering emulsions using depletion attraction

    Science.gov (United States)

    Kim, KyuHan; Kim, Subeen; Ryu, Jiheun; Jeon, Jiyoon; Jang, Se Gyu; Kim, Hyunjun; Gweon, Dae-Gab; Im, Won Bin; Han, Yosep; Kim, Hyunjung; Choi, Siyoung Q.

    2017-01-01

    High internal phase emulsions have been widely used as templates for various porous materials, but special strategies are required to form, in particular, particle-covered ones that have been more difficult to obtain. Here, we report a versatile strategy to produce a stable high internal phase Pickering emulsion by exploiting a depletion interaction between an emulsion droplet and a particle using water-soluble polymers as a depletant. This attractive interaction facilitating the adsorption of particles onto the droplet interface and simultaneously suppressing desorption once adsorbed. This technique can be universally applied to nearly any kind of particle to stabilize an interface with the help of various non- or weakly adsorbing polymers as a depletant, which can be solidified to provide porous materials for many applications. PMID:28145435

  18. Effect of Shim Arm Depletion in the NBSR

    Energy Technology Data Exchange (ETDEWEB)

    Hanson A. H.; Brown N.; Diamond, D.J.

    2013-02-22

    The cadmium shim arms in the NBSR undergo burnup during reactor operation and hence, require periodic replacement. Presently, the shim arms are replaced after every 25 cycles to guarantee they can maintain sufficient shutdown margin. Two prior reports document the expected change in the 113Cd distribution because of the shim arm depletion. One set of calculations was for the present high-enriched uranium fuel and the other for the low-enriched uranium fuel when it was in the COMP7 configuration (7 inch fuel length vs. the present 11 inch length). The depleted 113Cd distributions calculated for these cores were applied to the current design for an equilibrium low-enriched uranium core. This report details the predicted effects, if any, of shim arm depletion on the shim arm worth, the shutdown margin, power distributions and kinetics parameters.

  19. Transient Effects And Pump Depletion In Stimulated Raman Scattering

    Science.gov (United States)

    Carlsten, J. L.; Wenzel, R. G...; Druhl, K.

    1983-11-01

    Stimulated rotational Raman scattering in a 300-K multipass cell filled with para-H2 with a single-mode CO2-pumped laser is studied using a frequency-narrowed optical parametric oscillator (OPO) as a probe laser at the Stokes frequency for the So(0) transition. Amplification and pump depletion are examined as a function of incident pump energy. The pump depletion shows clear evidence of transient behavior. A theoretical treatment of transient stimulated Raman scattering, including effects of both pump depletion and medium saturation is presented. In a first approximation, diffraction effects are neglected, and only plane-wave interactions are considered. The theoretical results are compared to the experimental pulse shapes.

  20. Auxin-inducible protein depletion system in fission yeast

    Directory of Open Access Journals (Sweden)

    Kakimoto Tatsuo

    2011-02-01

    Full Text Available Abstract Background Inducible inactivation of a protein is a powerful approach for analysis of its function within cells. Fission yeast is a useful model for studying the fundamental mechanisms such as chromosome maintenance and cell cycle. However, previously published strategies for protein-depletion are successful only for some proteins in some specific conditions and still do not achieve efficient depletion to cause acute phenotypes such as immediate cell cycle arrest. The aim of this work was to construct a useful and powerful protein-depletion system in Shizosaccaromyces pombe. Results We constructed an auxin-inducible degron (AID system, which utilizes auxin-dependent poly-ubiquitination of Aux/IAA proteins by SCFTIR1 in plants, in fission yeast. Although expression of a plant F-box protein, TIR1, decreased Mcm4-aid, a component of the MCM complex essential for DNA replication tagged with Aux/IAA peptide, depletion did not result in an evident growth defect. We successfully improved degradation efficiency of Mcm4-aid by fusion of TIR1 with fission yeast Skp1, a conserved F-box-interacting component of SCF (improved-AID system; i-AID, and the cells showed severe defect in growth. The i-AID system induced degradation of Mcm4-aid in the chromatin-bound MCM complex as well as those in soluble fractions. The i-AID system in conjunction with transcription repression (off-AID system, we achieved more efficient depletion of other proteins including Pol1 and Cdc45, causing early S phase arrest. Conclusion Improvement of the AID system allowed us to construct conditional null mutants of S. pombe. We propose that the off-AID system is the powerful method for in vivo protein-depletion in fission yeast.

  1. Plasma depletion layer: Magnetosheath flow structure and forces

    Directory of Open Access Journals (Sweden)

    Y. L. Wang

    2004-03-01

    Full Text Available The plasma depletion layer (PDL is a layer on the sunward side of the magnetopause with lower plasma density and higher magnetic field compared to the corresponding upstream magnetosheath values. In a previous study, we have validated the UCLA global (MHD model in studying the formation of the PDL by comparing model results, using spacecraft solar wind observations as the driver, with in situ PDL observations. In this study, we extend our previous work and examine the detailed MHD forces responsible for the PDL formation. We argue that MHD models, instead of gasdynamic models, should be used to study the PDL, because gasdynamic models cannot produce the PDL on the sunward side of the magnetopause. For northward (IMF, flux tube depletion occurs in almost all the subsolar magnetosheath. However, the streamlines closest to the magnetopause and the stagnation line show the greatest depletion. The relative strength of the various MHD forces changes along these streamlines. Forces along a flux tube at different stages of its depletion in the magnetosheath are analyzed. We find that a strong plasma pressure gradient force along the magnetic field at the bow shock and a pressure gradient force along the flux tube within the magnetosheath usually exist pushing plasma away from the equatorial plane to deplete the flux tube. More complex force structures along the flux tube are found close to the magnetopause. This new, more detailed description of flux tube depletion is compared with the results of Zwan and Wolf (1976 and differences are found. Near the magnetopause, the pressure gradient force along the flux tube either drives plasma away from the equatorial plane or pushes plasma toward the equatorial plane. As a result, a slow mode structure is seen along the flux tube which might be responsible for the observed two-layered slow mode structures.

    Key words. Magnetospheric physics (magnetosheath; solar wind-magnetosphere interactions. Space

  2. Micelle-induced depletion interaction and resultant structure in charged colloidal nanoparticle system

    Energy Technology Data Exchange (ETDEWEB)

    Ray, D.; Aswal, V. K., E-mail: vkaswal@barc.gov.in [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kohlbrecher, J. [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 PSI Villigen (Switzerland)

    2015-04-28

    The evolution of the interaction and the resultant structure in the mixed system of anionic silica nanoparticles (Ludox LS30) and non-ionic surfactant decaethylene glycol monododecylether (C12E10), undergoing phase separation, have been studied using small-angle neutron scattering and dynamic light scattering. The measurements have been carried out for a fixed concentration of nanoparticle (1 wt. %) with varying concentration of surfactant (0 to 1 wt. %), in the absence and presence of an electrolyte. It is found that the micelles of non-ionic surfactant adsorb on the nanoparticle in the absence of electrolyte (form stable system), whereas these micelles become non-adsorbing in the presence of electrolyte (show phase separation). The phase separation arises because of C12E10 micelles, causing depletion interaction between nanoparticles and leading to their aggregation. The interaction is modeled by double Yukawa potential accounting for attractive depletion as well as repulsive electrostatic forces. Both the interactions (attraction and repulsion) are found to be of long-range. The nanoparticle aggregation (phase separation) is governed by the increase in the magnitude and the range of the depletion attraction with the increase in the surfactant concentration. The nanoparticle aggregates formed are quite large in size (order of micron) and are characterized by the surface fractal having simple cubic packing of nanoparticles within the aggregates.

  3. SCALE Continuous-Energy Monte Carlo Depletion with Parallel KENO in TRITON

    Energy Technology Data Exchange (ETDEWEB)

    Goluoglu, Sedat [ORNL; Bekar, Kursat B [ORNL; Wiarda, Dorothea [ORNL

    2012-01-01

    The TRITON sequence of the SCALE code system is a powerful and robust tool for performing multigroup (MG) reactor physics analysis using either the 2-D deterministic solver NEWT or the 3-D Monte Carlo transport code KENO. However, as with all MG codes, the accuracy of the results depends on the accuracy of the MG cross sections that are generated and/or used. While SCALE resonance self-shielding modules provide rigorous resonance self-shielding, they are based on 1-D models and therefore 2-D or 3-D effects such as heterogeneity of the lattice structures may render final MG cross sections inaccurate. Another potential drawback to MG Monte Carlo depletion is the need to perform resonance self-shielding calculations at each depletion step for each fuel segment that is being depleted. The CPU time and memory required for self-shielding calculations can often eclipse the resources needed for the Monte Carlo transport. This summary presents the results of the new continuous-energy (CE) calculation mode in TRITON. With the new capability, accurate reactor physics analyses can be performed for all types of systems using the SCALE Monte Carlo code KENO as the CE transport solver. In addition, transport calculations can be performed in parallel mode on multiple processors.

  4. Oxygen depletion recorded in upper waters of the glacial Southern Ocean

    Science.gov (United States)

    Lu, Zunli; Hoogakker, Babette A. A.; Hillenbrand, Claus-Dieter; Zhou, Xiaoli; Thomas, Ellen; Gutchess, Kristina M.; Lu, Wanyi; Jones, Luke; Rickaby, Rosalind E. M.

    2016-01-01

    Oxygen depletion in the upper ocean is commonly associated with poor ventilation and storage of respired carbon, potentially linked to atmospheric CO2 levels. Iodine to calcium ratios (I/Ca) in recent planktonic foraminifera suggest that values less than ∼2.5 μmol mol−1 indicate the presence of O2-depleted water. Here we apply this proxy to estimate past dissolved oxygen concentrations in the near surface waters of the currently well-oxygenated Southern Ocean, which played a critical role in carbon sequestration during glacial times. A down-core planktonic I/Ca record from south of the Antarctic Polar Front (APF) suggests that minimum O2 concentrations in the upper ocean fell below 70 μmol kg−1 during the last two glacial periods, indicating persistent glacial O2 depletion at the heart of the carbon engine of the Earth's climate system. These new estimates of past ocean oxygenation variability may assist in resolving mechanisms responsible for the much-debated ice-age atmospheric CO2 decline. PMID:27029225

  5. Depleted internal store-activated Ca2+ entry can trigger neurotransmitter release in bovine chromaffin cells.

    Science.gov (United States)

    Powis, D A; Clark, C L; O'Brien, K J

    1996-02-09

    A potential role of the intracellular Ca2+ stores in modulating catecholamine release has been investigated in bovine chromaffin cells maintained in tissue culture. Pharmacological depletion of the stores with a combination of caffeine, histamine and thapsigargin in Ca2+-free media resulted in a significantly greater release of catecholamines on re-exposure to Ca2+-containing media compared with that from non-store depleted cells. The increase in catecholamine release was prevented by intracellular BAPTA indicating that the increase was caused by a rise in Ca2+. Measurement of intracellular free Ca2+ concentration with the fluorescent indicator, fura-2, over the same time-course as the catecholamine release experiments showed that upon restoration of external Ca2+ there was an immediate, substantial and maintained increase in cytosolic Ca2+. It is most probable that the increase in catecholamine release was a consequence of an increase in Ca2+ influx triggered by prior depletion of the internal Ca2+ stores. However, the data suggest that capacitative Ca2+ entry is poorly linked to catecholamine release; although Ca2+ entry on restoration of external Ca2+ was immediate and substantial, the increase in catecholamine release, although quantitatively significant, was slowly realised.

  6. Proteomic and cellular views of Arthrospira sp. PCC 8005 adaptation to nitrogen depletion.

    Science.gov (United States)

    Deschoenmaeker, Frédéric; Facchini, Raphaël; Leroy, Baptiste; Badri, Hanène; Zhang, C-C; Wattiez, Ruddy

    2014-06-01

    Cyanobacteria are photosynthetic prokaryotes that play a crucial role in the Earth's nitrogen and carbon cycles. Nitrogen availability is one of the most important factors in cyanobacterial growth. Interestingly, filamentous non-diazotrophic cyanobacteria, such as Arthrospira sp. PCC 8005, have developed survival strategies that enable them to adapt to nitrogen deprivation. Metabolic studies recently demonstrated a substantial synthesis and accumulation of glycogen derived from amino acids during nitrogen starvation. Nevertheless, the regulatory mechanism of this adaptation is poorly understood. To the best of our knowledge, this study is the first proteomic and cellular analysis of Arthrospira sp. PCC 8005 under nitrogen depletion. Label-free differential proteomic analysis indicated the global carbon and nitrogen reprogramming of the cells during nitrogen depletion as characterized by an upregulation of glycogen synthesis and the use of endogenous nitrogen sources. The degradation of proteins and cyanophycin provided endogenous nitrogen when exogenous nitrogen was limited. Moreover, formamides, cyanates and urea were also potential endogenous nitrogen sources. The transporters of some amino acids and alternative nitrogen sources such as ammonium permease 1 were induced under nitrogen depletion. Intriguingly, although Arthrospira is a non-diazotrophic cyanobacterium, we observed the upregulation of HetR and HglK proteins, which are involved in heterocyst differentiation. Moreover, after a long period without nitrate, only a few highly fluorescent cells in each trichome were observed, and they might be involved in the long-term survival mechanism of this non-diazotrophic cyanobacterium under nitrogen deprivation.

  7. Oxygen Depletion in the Interstellar Medium: Implications for Grain Models and the Distribution of Elemental Oxygen

    CERN Document Server

    Whittet, D C B

    2009-01-01

    This paper assesses the implications of a recent discovery (Jenkins 2009) that atomic oxygen is being depleted from diffuse interstellar gas at a rate that cannot be accounted for by its presence in silicate and metallic oxide particles. To place this discovery in context, the uptake of elemental O into dust is considered over a wide range of environments, from the tenuous intercloud gas and diffuse clouds sampled by the depletion observations to dense clouds where ice mantles and gaseous CO become important reservoirs of O. The distribution of O in these contrasting regions is quantified in terms of a common parameter, the mean number density of hydrogen. At the interface between diffuse and dense phases (just before the onset of ice mantle growth) as much as 160 ppm of the O abundance is unaccounted for. If this reservoir of depleted oxygen persists to higher densities it has implications for the oxygen budget in molecular clouds, where a shortfall of the same order is observed. Of various potential carrier...

  8. Climate change, ozone depletion and the impact on ultraviolet exposure of human skin

    Energy Technology Data Exchange (ETDEWEB)

    Diffey, Brian [Regional Medical Physics Department, Newcastle General Hospital, Newcastle NE4 6BE (United Kingdom)

    2004-01-07

    For 30 years there has been concern that anthropogenic damage to the Earth's stratospheric ozone layer will lead to an increase of solar ultraviolet (UV) radiation reaching the Earth's surface, with a consequent adverse impact on human health, especially to the skin. More recently, there has been an increased awareness of the interactions between ozone depletion and climate change (global warming), which could also impact on human exposure to terrestrial UV. The most serious effect of changing UV exposure of human skin is the potential rise in incidence of skin cancers. Risk estimates of this disease associated with ozone depletion suggest that an additional peak incidence of 5000 cases of skin cancer per year in the UK would occur around the mid-part of this century. Climate change, which is predicted to lead to an increased frequency of extreme temperature events and high summer temperatures, will become more frequent in the UK. This could impact on human UV exposure by encouraging people to spend more time in the sun. Whilst future social trends remain uncertain, it is likely that over this century behaviour associated with climate change, rather than ozone depletion, will be the largest determinant of sun exposure, and consequent impact on skin cancer, of the UK population. (topical review)

  9. Climate change, ozone depletion and the impact on ultraviolet exposure of human skin.

    Science.gov (United States)

    Diffey, Brian

    2004-01-07

    For 30 years there has been concern that anthropogenic damage to the Earth's stratospheric ozone layer will lead to an increase of solar ultraviolet (UV) radiation reaching the Earth's surface, with a consequent adverse impact on human health, especially to the skin. More recently, there has been an increased awareness of the interactions between ozone depletion and climate change (global warming), which could also impact on human exposure to terrestrial UV. The most serious effect of changing UV exposure of human skin is the potential rise in incidence of skin cancers. Risk estimates of this disease associated with ozone depletion suggest that an additional peak incidence of 5000 cases of skin cancer per year in the UK would occur around the mid-part of this century. Climate change, which is predicted to lead to an increased frequency of extreme temperature events and high summer temperatures, will become more frequent in the UK. This could impact on human UV exposure by encouraging people to spend more time in the sun. Whilst future social trends remain uncertain, it is likely that over this century behaviour associated with climate change, rather than ozone depletion, will be the largest determinant of sun exposure, and consequent impact on skin cancer, of the UK population.

  10. The Effect of Climate Change on Ozone Depletion through Changes in Stratospheric Water Vapour

    Science.gov (United States)

    Kirk-Davidoff, Daniel B.; Hintsa, Eric J.; Anderson, James G.; Keith, David W.

    1999-01-01

    Several studies have predicted substantial increases in Arctic ozone depletion due to the stratospheric cooling induced by increasing atmospheric CO2 concentrations. But climate change may additionally influence Arctic ozone depletion through changes in the water vapor cycle. Here we investigate this possibility by combining predictions of tropical tropopause temperatures from a general circulation model with results from a one-dimensional radiative convective model, recent progress in understanding the stratospheric water vapor budget, modelling of heterogeneous reaction rates and the results of a general circulation model on the radiative effect of increased water vapor. Whereas most of the stratosphere will cool as greenhouse-gas concentrations increase, the tropical tropopause may become warmer, resulting in an increase of the mean saturation mixing ratio of water vapor and hence an increased transport of water vapor from the troposphere to the stratosphere. Stratospheric water vapor concentration in the polar regions determines both the critical temperature below which heterogeneous reactions on cold aerosols become important (the mechanism driving enhanced ozone depletion) and the temperature of the Arctic vortex itself. Our results indicate that ozone loss in the later winter and spring Arctic vortex depends critically on water vapor variations which are forced by sea surface temperature changes in the tropics. This potentially important effect has not been taken into account in previous scenarios of Arctic ozone loss under climate change conditions.

  11. 3-bromopyruvate inhibits glycolysis, depletes cellular glutathione, and compromises the viability of cultured primary rat astrocytes.

    Science.gov (United States)

    Ehrke, Eric; Arend, Christian; Dringen, Ralf

    2015-07-01

    The pyruvate analogue 3-bromopyruvate (3-BP) is an electrophilic alkylator that is considered a promising anticancer drug because it has been shown to kill cancer cells efficiently while having little toxic effect on nontumor cells. To test for potential adverse effects of 3-BP on brain cells, we exposed cultured primary rat astrocytes to 3-BP and investigated the effects of this compound on cell viability, glucose metabolism, and glutathione (GSH) content. The presence of 3-BP severely compromised cell viability and slowed cellular glucose consumption and lactate production in a time- and concentration-dependent manner, with half-maximal effects observed at about 100 µM 3-BP after 4 hr of incubation. The cellular hexokinase activity was not affected in 3-BP-treated astrocytes, whereas within 30 min after application of 3-BP the activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was inhibited, and cellular GSH content was depleted in a concentration-dependent manner, with half-maximal effects observed at about 30 µM 3-BP. The depletion of cellular GSH after exposure to 100 µM 3-BP was not prevented by the presence of 10 mM of the monocarboxylates lactate or pyruvate, suggesting that 3-BP is not taken up into astrocytes predominantly by monocarboxylate transporters. The data suggest that inhibition of glycolysis by inactivation of GAPDH and GSH depletion contributes to the toxicity that was observed for 3-BP-treated cultured astrocytes.

  12. Depleting MEKK1 expression inhibits the ability of invasion and migration of human pancreatic cancer cells.

    Science.gov (United States)

    Su, Fuqin; Li, Hongyan; Yan, Chaoqi; Jia, Baoqing; Zhang, Yi; Chen, Xiaoguang

    2009-12-01

    Mitogen-activated protein/ERK kinase 1 (MEKK1) is a Ser/Thr protein kinase belonging to the MEKK/STE11 subgroup of the MAPKKK family and plays a key role in tumor metastasis. However, it remains unclear about its functions in pancreatic cancer. We analyzed MEKK1 expression in 41 surgically resection pancreatic cancer patient's samples by immunohistochemistry and determined its role in BxPC3 cells via RNAi experiment. The abilities of invasion, motility, and adhesion of BxPC3 cells were detected by transwell assay, wound healing assay and adhesion assay, respectively. Gelatinase activity of MMPs in cultured cells was examined by gelatin zymography. Our data showed that MEKK1 expression is positively correlated with lymphatic metastases (P BxPC3 cells were inhibited significantly (P < 0.01) when MEKK1 was depleted with a specific siRNA. We observed that the activity of MMP2 was decreased in the MEKK1 depletion cell line (P < 0.05), accompanied with decreased phosphorylated ERK1/2. Our results indicated that the depletion of MEKK1 led to a potent inhibition on the invasion and migration of human pancreatic adenocarcinoma in vitro. It suggests that MEKK1 may be a potential target for development of anti-invasion and metastasis drugs.

  13. Activation of TRPV1 channels inhibits mechanosensitive Piezo channel activity by depleting membrane phosphoinositides.

    Science.gov (United States)

    Borbiro, Istvan; Badheka, Doreen; Rohacs, Tibor

    2015-02-10

    Capsaicin is an activator of the heat-sensitive TRPV1 (transient receptor potential vanilloid 1) ion channels and has been used as a local analgesic. We found that activation of TRPV1 channels with capsaicin either in dorsal root ganglion neurons or in a heterologous expression system inhibited the mechanosensitive Piezo1 and Piezo2 channels by depleting phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] and its precursor phosphatidylinositol 4-phosphate [PI(4)P] from the plasma membrane through Ca(2+)-induced phospholipase Cδ (PLCδ) activation. Experiments with chemically inducible phosphoinositide phosphatases and receptor-induced activation of PLCβ indicated that inhibition of Piezo channels required depletion of both PI(4)P and PI(4,5)P2. The mechanically activated current amplitudes decreased substantially in the excised inside-out configuration, where the membrane patch containing Piezo1 channels is removed from the cell. PI(4,5)P2 and PI(4)P applied to these excised patches inhibited this decrease. Thus, we concluded that Piezo channel activity requires the presence of phosphoinositides, and the combined depletion of PI(4,5)P2 and PI(4)P reduces channel activity. In addition to revealing a role for distinct membrane lipids in mechanosensitive ion channel regulation, these data suggest that inhibition of Piezo2 channels may contribute to the analgesic effect of capsaicin.

  14. NUMERICAL SIMULATION FOR FORMED PROJECTILE OF DEPLETED URANIUM ALLOY

    Institute of Scientific and Technical Information of China (English)

    宋顺成; 高平; 才鸿年

    2003-01-01

    The numerical simulation for forming projectile of depleted uranium alloy with the SPH ( Smooth Particle Hydrodynamic ) algorithm was presented. In the computations the artificial pressures of detonation were used, i. e. , the spatial distribution and time distribution were given artificially. To describe the deformed behaviors of the depleted uranium alloy under high pressure and high strain rate, the Johnson-Cook model of materials was introduced. From the numerical simulation the formed projectile velocity,projectile geometry and the minimum of the height of detonation are obtained.

  15. Depletion zone calculation of MAPS detectors using TCAD simulations

    CERN Document Server

    Khan, Hira

    2013-01-01

    The volume of the depleted region of the collecting diode plays a vital role in the charge collection when an ionization particle traverses the Monolithic Active Pixel Sensor (MAPS) detector. Thus the volume of the depletion region should be large enough to collect majority electron-hole pairs generated by the ionization particle otherwise they will diffuse and eventually will take longer time for them to be collected. This report is about simulating a collecting diode (sector 4) with increased resistivity, in TCAD. After that comparing the results with the results of a low resistive collecting diode.

  16. UV radiation below an Arctic vortex with severe ozone depletion

    Directory of Open Access Journals (Sweden)

    B. M. Knudsen

    2005-01-01

    Full Text Available The erythemally weighted (UV irradiance below the severely depleted Arctic vortices in spring 1996 and 1997 were substantially elevated. On average the UV increased 36 and 33% relative to the 1979-1981 mean assuming clear skies from day 80-100 in 1996 and 1997, respectively. On clear sky days large regions of the Arctic experienced maximum UV increases exceeding 70 and 50% on single days in 1996 and 1997, respectively. A minor fraction of these increases are not anthropogenic and have a dynamical origin as seen by comparison to 1982, when hardly any ozone depletion is expected.

  17. Towards a complete propagation uncertainties in depletion calculations

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, J.S. [Universidad Politecnica de Madrid (Spain). Dept. of Nuclear Engineering; Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Garching (Germany); Zwermann, W.; Gallner, L.; Puente-Espel, Federico; Velkov, K.; Hannstein, V. [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Garching (Germany); Cabellos, O. [Universidad Politecnica de Madrid (Spain). Dept. of Nuclear Engineering

    2013-07-01

    Propagation of nuclear data uncertainties to calculated values is interesting for design purposes and libraries evaluation. XSUSA, developed at GRS, propagates cross section uncertainties to nuclear calculations. In depletion simulations, fission yields and decay data are also involved and are a possible source of uncertainty that should be taken into account. We have developed tools to generate varied fission yields and decay libraries and to propagate uncertainties through depletion in order to complete the XSUSA uncertainty assessment capabilities. A generic test to probe the methodology is defined and discussed. (orig.)

  18. ROLE OF NUCLEONIC FERMI SURFACE DEPLETION IN NEUTRON STAR COOLING

    Energy Technology Data Exchange (ETDEWEB)

    Dong, J. M.; Zuo, W. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Lombardo, U. [Universita di Catania and Laboratori Nazionali del Sud (INFN), Catania I-95123 (Italy); Zhang, H. F. [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China)

    2016-01-20

    The Fermi surface depletion of beta-stable nuclear matter is calculated to study its effects on several physical properties that determine the neutron star (NS) thermal evolution. The neutron and proton Z factors measuring the corresponding Fermi surface depletions are calculated within the Brueckner–Hartree–Fock approach, employing the AV18 two-body force supplemented by a microscopic three-body force. Neutrino emissivity, heat capacity, and in particular neutron {sup 3}PF{sub 2} superfluidity, turn out to be reduced, especially at high baryonic density, to such an extent that the cooling rates of young NSs are significantly slowed.

  19. Summer time Fe depletion in the Antarctic mesopause region

    Science.gov (United States)

    Viehl, T. P.; Höffner, J.; Lübken, F.-J.; Plane, J. M. C.; Kaifler, B.; Morris, R. J.

    2015-05-01

    We report common volume measurements of Fe densities, temperatures and ice particle occurrence in the mesopause region at Davis Station, Antarctica (69°S) in the years 2011-2012. Our observations show a strong correlation of the Fe-layer summer time depletion with temperature, but no clear causal relation with the onset or occurrence of ice particles measured as noctilucent clouds (NLC) or polar mesosphere summer echoes (PMSE). The combination of these measurements indicates that the strong summer depletion can be explained by gas-phase chemistry alone and does not require heterogeneous removal of Fe and its compounds on ice particles.

  20. Gut microbiota depletion from early adolescence in mice: Implications for brain and behaviour.

    Science.gov (United States)

    Desbonnet, Lieve; Clarke, Gerard; Traplin, Alexander; O'Sullivan, Orla; Crispie, Fiona; Moloney, Rachel D; Cotter, Paul D; Dinan, Timothy G; Cryan, John F

    2015-08-01

    There is growing appreciation for the importance of bacteria in shaping brain development and behaviour. Adolescence and early adulthood are crucial developmental periods during which exposure to harmful environmental factors can have a permanent impact on brain function. Such environmental factors include perturbations of the gut bacteria that may affect gut-brain communication, altering the trajectory of brain development, and increasing vulnerability to psychiatric disorders. Here we assess the effects of gut bacterial depletion from weaning onwards on adult cognitive, social and emotional behaviours and markers of gut-brain axis dysfunction in mice. Mice were treated with a combination of antibiotics from weaning onwards and effects on behaviours and potential gut-brain axis neuromodulators (tryptophan, monoamines, and neuropeptides) and BDNF expression were assessed in adulthood. Antibiotic-treatment depleted and restructured gut microbiota composition of caecal contents and decreased spleen weights in adulthood. Depletion of the gut microbiota from weaning onwards reduced anxiety, induced cognitive deficits, altered dynamics of the tryptophan metabolic pathway, and significantly reduced BDNF, oxytocin and vasopressin expression in the adult brain. Microbiota depletion from weaning onwards by means of chronic treatment with antibiotics in mice impacts on anxiety and cognitive behaviours as well as key neuromodulators of gut-brain communication in a manner that is similar to that reported in germ-free mice. This model may represent a more amenable alternative for germ-free mice in the assessment of microbiota modulation of behaviour. Finally, these data suggest that despite the presence of a normal gut microbiome in early postnatal life, reduced abundance and diversity of the gut microbiota from weaning influences adult behaviours and key neuromodulators of the microbiota-gut-brain axis suggesting that dysregulation of this axis in the post-weaning period may

  1. B-Cell Depletion Reduces the Maturation of Cerebral Cavernous Malformations in Murine Models.

    Science.gov (United States)

    Shi, Changbin; Shenkar, Robert; Zeineddine, Hussein A; Girard, Romuald; Fam, Maged D; Austin, Cecilia; Moore, Thomas; Lightle, Rhonda; Zhang, Lingjiao; Wu, Meijing; Cao, Ying; Gunel, Murat; Louvi, Angeliki; Rorrer, Autumn; Gallione, Carol; Marchuk, Douglas A; Awad, Issam A

    2016-06-01

    Cerebral cavernous malformations (CCMs) are relatively common vascular malformations, characterized by increased Rho kinase (ROCK) activity, vascular hyper-permeability and the presence of blood degradation products including non-heme iron. Previous studies revealed robust inflammatory cell infiltration, selective synthesis of IgG, in situ antigen driven B-cell clonal expansion, and deposition of immune complexes and complement proteins within CCM lesions. We aimed to evaluate the impact of suppressing the immune response on the formation and maturation of CCM lesions, as well as lesional iron deposition and ROCK activity. Two murine models of heterozygous Ccm3 (Pdcd10), which spontaneously develop CCM lesions with severe and milder phenotypes, were either untreated or received anti-mouse BR3 to deplete B cells. Brains from anti-mouse BR3-treated mice exhibited significantly fewer mature CCM lesions and smaller lesions compared to untreated mice. B cell depletion halted the progression of lesions into mature stage 2 lesions but did not prevent their genesis. Non-heme iron deposition and ROCK activity was decreased in lesions of B cell depleted mice. This represents the first report of the therapeutic benefit of B-cell depletion in the development and progression of CCMs, and provides a proof of principle that B cells play a critical role in CCM lesion genesis and maturation. These findings add biologics to the list of potential therapeutic agents for CCM disease. Future studies would characterize the putative antigenic trigger and further define the mechanism of immune response in the lesions.

  2. Groundwater Depletion in Dhaka City, Bangladesh: A Spatio-temporal Analysis

    Science.gov (United States)

    Jerin, T.; Ishtiaque, A.

    2015-12-01

    Dhaka city, having a population of more than fifteen million, exclusively depends on groundwater as a source of quality drinking water. In recent decades the city is encountering groundwater diminution and the declining scenario is dissimilar in different parts of the city. This paper aims to discuss the groundwater depletion in different parts of Dhaka city from 1990 to 2012 along with the causes and consequences. Groundwater level data of different locations of Dhaka city were collected from Bangladesh Water Development Board (BWDB). The data were processed and analyzed using SPSS and Excel Worksheet; a contour map was generated using ArcGIS 10.0 to outline the contemporary groundwater scenario of Dhaka city and the spatial analyst tool, Inverse Distance Weighted (IDW) was used to prepare the map. In addition, experts' opinions were collected using an in-depth interview strategy in order to provide a better understanding of the causes and consequences of groundwater depletion. The research results show that groundwater in Dhaka city is depleting at an alarming rate; the central part has the worst situation followed by the south-western part. In contrast, northern part has relatively better groundwater condition. Moreover, the peripheral zone exhibits a better condition because of the existence of rivers and wetlands. The interviews reveal that population density and overexploitation are mainly responsible for groundwater depletion; however, various other factors such as the deliberate establishment of deep tube wells, reduction of recharge capacity due to rapid growth of urban structures altogether results in huge drop of water level throughout the city. Rapid decline in groundwater augments the city's exposure towards multiple risks including land subsidence, groundwater pollution and most importantly, paucity of available fresh water that might ultimately results into an urban disaster. Potential solutions to ameliorate this situation include urban greening

  3. Untangling Magmatic Processes and Hydrothermal Alteration of in situ Superfast Spreading Ocean Crust at ODP/IODP Site 1256 with Fuzzy c-means Cluster Analysis of Rock Magnetic Properties

    Science.gov (United States)

    Dekkers, M. J.; Heslop, D.; Herrero-Bervera, E.; Acton, G.; Krasa, D.

    2014-12-01

    Ocean Drilling Program (ODP)/Integrated ODP (IODP) Hole 1256D (6.44.1' N, 91.56.1' W) on the Cocos Plate occurs in 15.2 Ma oceanic crust generated by superfast seafloor spreading. Presently, it is the only drill hole that has sampled all three oceanic crust layers in a tectonically undisturbed setting. Here we interpret down-hole trends in several rock-magnetic parameters with fuzzy c-means cluster analysis, a multivariate statistical technique. The parameters include the magnetization ratio, the coercivity ratio, the coercive force, the low-field susceptibility, and the Curie temperature. By their combined, multivariate, analysis the effects of magmatic and hydrothermal processes can be evaluated. The optimal number of clusters - a key point in the analysis because there is no a priori information on this - was determined through a combination of approaches: by calculation of several cluster validity indices, by testing for coherent cluster distributions on non-linear-map plots, and importantly by testing for stability of the cluster solution from all possible starting points. Here, we consider a solution robust if the cluster allocation is independent of the starting configuration. The five-cluster solution appeared to be robust. Three clusters are distinguished in the extrusive segment of the Hole that express increasing hydrothermal alteration of the lavas. The sheeted dike and gabbro portions are characterized by two clusters, both with higher coercivities than in lava samples. Extensive alteration, however, can obliterate magnetic property differences between lavas, dikes, and gabbros. The imprint of thermochemical alteration on the iron-titanium oxides is only partially related to the porosity of the rocks. All clusters display rock magnetic characteristics in line with a stable NRM. This implies that the entire sampled sequence of ocean crust can contribute to marine magnetic anomalies. Determination of the absolute paleointensity with thermal techniques is

  4. Demixing transition, structure, and depletion forces in binary mixtures of hard-spheres: the role of bridge functions.

    Science.gov (United States)

    López-Sánchez, Erik; Estrada-Álvarez, César D; Pérez-Ángel, Gabriel; Méndez-Alcaraz, José Miguel; González-Mozuelos, Pedro; Castañeda-Priego, Ramón

    2013-09-14

    Asymmetric binary mixtures of hard-spheres exhibit several interesting thermodynamic phenomena, such as multiple kinds of glassy states. When the degrees of freedom of the small spheres are integrated out from the description, their effects are incorporated into an effective pair interaction between large spheres known as the depletion potential. The latter has been widely used to study both the phase behavior and dynamic arrest of the big particles. Depletion forces can be accounted for by a contraction of the description in the multicomponent Ornstein-Zernike equation [R. Castañeda-Priego, A. Rodríguez-López, and J. M. Méndez-Alcaraz, Phys. Rev. E 73, 051404 (2006)]. Within this theoretical scheme, an approximation for the difference between the effective and bare bridge functions is needed. In the limit of infinite dilution, this difference is irrelevant and the typical Asakura-Osawa depletion potential is recovered. At higher particle concentrations, however, this difference becomes important, especially where the shell of first neighbors is formed, and, as shown here, cannot be simply neglected. In this work, we use a variant of the Verlet expression for the bridge functions to highlight their importance in the calculation of the depletion potential at high densities and close to the spinodal decomposition. We demonstrate that the modified Verlet closure predicts demixing in binary mixtures of hard spheres for different size ratios and compare its predictions with both liquid state and density functional theories, computer simulations, and experiments. We also show that it provides accurate correlation functions even near the thermodynamic instability; this is explicitly corroborated with results of molecular dynamics simulations of the whole mixture. Particularly, our findings point toward a possible universal behavior of the depletion potential around the spinodal line.

  5. HFC-134a Export Expansion in Great Urgency

    Institute of Scientific and Technical Information of China (English)

    Zhang Lizhe

    2007-01-01

    @@ 1,1,1,2-tetrafluoroethane (HFC- 134a) is a new refrigerant. It has the features of no toxicity, no odor, no color, no inflammability, no explosion, good thermal stability and stable chemical property. Its ODP (ozone depletion potential) is zero. It has a refrigerating ability similar to F12.

  6. 5.0. Depletion, activation, and spent fuel source terms

    Energy Technology Data Exchange (ETDEWEB)

    Wieselquist, William A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-04-01

    SCALE’s general depletion, activation, and spent fuel source terms analysis capabilities are enabled through a family of modules related to the main ORIGEN depletion/irradiation/decay solver. The nuclide tracking in ORIGEN is based on the principle of explicitly modeling all available nuclides and transitions in the current fundamental nuclear data for decay and neutron-induced transmutation and relies on fundamental cross section and decay data in ENDF/B VII. Cross section data for materials and reaction processes not available in ENDF/B-VII are obtained from the JEFF-3.0/A special purpose European activation library containing 774 materials and 23 reaction channels with 12,617 neutron-induced reactions below 20 MeV. Resonance cross section corrections in the resolved and unresolved range are performed using a continuous-energy treatment by data modules in SCALE. All nuclear decay data, fission product yields, and gamma-ray emission data are developed from ENDF/B-VII.1 evaluations. Decay data include all ground and metastable state nuclides with half-lives greater than 1 millisecond. Using these data sources, ORIGEN currently tracks 174 actinides, 1149 fission products, and 974 activation products. The purpose of this chapter is to describe the stand-alone capabilities and underlying methodology of ORIGEN—as opposed to the integrated depletion capability it provides in all coupled neutron transport/depletion sequences in SCALE, as described in other chapters.

  7. CD20(+) B Cell Depletion Alters T Cell Homing

    NARCIS (Netherlands)

    Kap, Yolanda S.; van Driel, Nikki; Laman, Jon D.; Tak, Paul P.; 't Hart, Bert A.

    2014-01-01

    Depleting mAbs against the pan B cell marker CD20 are remarkably effective in the treatment of autoimmune-mediated inflammatory disorders, but the underlying mechanisms are poorly defined. The primary objective of this study was to find a mechanistic explanation for the remarkable clinical effect of

  8. Gain depletion of X-ray framing camera

    Science.gov (United States)

    Koga, M.; Shiraga, H.

    2017-08-01

    X-ray imaging is very useful to investigate imploded core plasma in inertial fusion experiments. We can obtain information from X-ray images, such as shape, density, and temperature. An X-ray framing camera (XFC) capable of taking two-dimensional, time-resolved X-ray images is used to capture the images. In previous work, we developed a numerical model of an XFC to analyze its X-ray image. The calculated results agreed qualitatively with experimental results. However, it was not accurate enough to determine the absolute value of the signal. We thought this discrepancy was caused by gain depletion. In high energy laser experiments, high photon flux may cause gain depletion. This is a problem for accurate X-ray measurement. In this paper, we report our new model, including gain depletion. The new model is evaluated by tabletop laser experiments and high energy laser experiments. The results calculated using the new model agree quantitatively with our experimental results. Furthermore, we confirmed that gain depletion occurs in our high energy laser experiments. For quantitatively accurate X-ray intensity measurements, the XFC should be used with limited incident photon flux such that the gain linearity is guaranteed.

  9. Depletion of mitochondria in mammalian cells through enforced mitophagy.

    Science.gov (United States)

    Correia-Melo, Clara; Ichim, Gabriel; Tait, Stephen W G; Passos, João F

    2017-01-01

    Mitochondria are not only the 'powerhouse' of the cell; they are also involved in a multitude of processes that include calcium storage, the cell cycle and cell death. Traditional means of investigating mitochondrial importance in a given cellular process have centered upon depletion of mtDNA through chemical or genetic means. Although these methods severely disrupt the mitochondrial electron transport chain, mtDNA-depleted cells still maintain mitochondria and many mitochondrial functions. Here we describe a straightforward protocol to generate mammalian cell populations with low to nondetectable levels of mitochondria. Ectopic expression of the ubiquitin E3 ligase Parkin, combined with short-term mitochondrial uncoupler treatment, stimulates widespread mitophagy and effectively eliminates mitochondria. In this protocol, we explain how to generate Parkin-expressing, mitochondria-depleted cells from scratch in 23 d, as well as offer a variety of methods for confirming mitochondrial clearance. Furthermore, we describe culture conditions to maintain mitochondrial-depleted cells for up to 30 d with minimal loss of viability, for longitudinal studies. This method should prove useful for investigating the importance of mitochondria in a variety of biological processes.

  10. Ozone depletion and skin cancer incidence: an integrated modelling approach

    NARCIS (Netherlands)

    Slaper H; den Elzen MGJ; de Woerd HJ; de Greef J

    1992-01-01

    A decrease in stratospheric ozone, probably caused by chlorofluorocarbon (CFC) emissions, has been observed over large parts of the globe. The incidence of skin cancer is expected to increase due to ozone depletion. An integrated source-risk model is developed and applied to evaluate the increased

  11. Associative Interactions in Crowded Solutions of Biopolymers Counteract Depletion Effects

    NARCIS (Netherlands)

    Groen, Joost; Foschepoth, David; te Brinke, Esra; Boersma, Arnold J; Imamura, Hiromi; Rivas, Germán; Heus, Hans A; Huck, Wilhelm T S

    2015-01-01

    The cytosol of Escherichia coli is an extremely crowded environment, containing high concentrations of biopolymers which occupy 20-30% of the available volume. Such conditions are expected to yield depletion forces, which strongly promote macromolecular complexation. However, crowded macromolecule s

  12. Ultrahigh-contrast imaging by temporally modulated stimulated emission depletion

    NARCIS (Netherlands)

    Doronina-Amitonova, L.V.; Fedotov, I.V.; Zheltikov, A.M.

    2015-01-01

    Stimulated emission depletion (STED) is the key optical technology enabling super-resolution microscopy below the diffraction limit. Here, we demonstrate that modulation of STED in the time domain, combined with properly designed lock-in detection, can radically enhance the contrast of fluorescent i

  13. Stimulated scintillation emission depletion X-ray imaging.

    Science.gov (United States)

    Alekhin, M S; Patton, G; Dujardin, C; Douissard, P-A; Lebugle, M; Novotny, L; Stampanoni, M

    2017-01-23

    X-ray microtomography is a widely applied tool for noninvasive structure investigations. The related detectors are usually based on a scintillator screen for the fast in situ conversion of an X-ray image into an optical image. Spatial resolution of the latter is fundamentally diffraction limited. In this work, we introduce stimulated scintillation emission depletion (SSED) X-ray imaging where, similar to stimulated emission depletion (STED) microscopy, a depletion beam is applied to the scintillator screen to overcome the diffraction limit. The requirements for the X-ray source, the X-ray flux, the scintillator screen, and the STED beam were evaluated. Fundamental spatial resolution limits due to the spread of absorbed X-ray energy were estimated with Monte Carlo simulations. The SSED proof-of-concept experiments demonstrated 1) depletion of X-ray excited scintillation, 2) partial confinement of scintillating regions to sub-diffraction sized volumes, and 3) improvement of the imaging contrast by applying SSED.

  14. Ozone depletion and skin cancer incidence: an integrated modelling approach

    NARCIS (Netherlands)

    Slaper H; den Elzen MGJ; de Woerd HJ; de Greef J

    1992-01-01

    A decrease in stratospheric ozone, probably caused by chlorofluorocarbon (CFC) emissions, has been observed over large parts of the globe. The incidence of skin cancer is expected to increase due to ozone depletion. An integrated source-risk model is developed and applied to evaluate the increased

  15. Vitamin D depletion aggravates hypertension and target-organ damage

    DEFF Research Database (Denmark)

    Andersen, Louise Bjørkholt; Przybyl, Lukasz; Haase, Nadine

    2015-01-01

    BACKGROUND: We tested the controversial hypothesis that vitamin D depletion aggravates hypertension and target-organ damage by influencing renin. METHODS AND RESULTS: Four-week-old double-transgenic rats (dTGR) with excess angiotensin (Ang) II production due to overexpression of the human renin (h......REN) and angiotensinogen (hAGT) genes received vitamin D-depleted (n=18) or standard chow (n=15) for 3 weeks. The depleted group had very low serum 25-hydroxyvitamin D levels (mean±SEM; 3.8±0.29 versus 40.6±1.19 nmol/L) and had higher mean systolic BP at week 5 (158±3.5 versus 134.6±3.7 mm Hg, P....6±3.3 versus 162.3±3.8 mm Hg, PVitamin D depletion led to increased relative heart weights and increased serum creatinine concentrations. Furthermore, the mRNAs of natriuretic peptides, neutrophil gelatinase-associated lipocalin, hREN, and r...

  16. Protection of ATP-Depleted Cells by Impermeant Strychnine Derivatives

    Science.gov (United States)

    Dong, Zheng; Venkatachalam, Manjeri A.; Weinberg, Joel M.; Saikumar, Pothana; Patel, Yogendra

    2001-01-01

    Glycine and structurally related amino acids with activities at chloride channel receptors in the central nervous system also have robust protective effects against cell injury by ATP depletion. The glycine receptor antagonist strychnine shares this protective activity. An essential step toward identification of the molecular targets for these compounds is to determine whether they protect cells through interactions with intracellular targets or with molecules on the outer surface of plasma membranes. Here we report cytoprotection by a cell-impermeant derivative of strychnine. A strychnine-fluorescein conjugate (SF) was synthesized, and impermeability of plasma membranes to this compound was verified by fluorescence confocal microscopy. In an injury model of Madin-Darby canine kidney cells, ATP depletion led to lactate dehydrogenase release. SF prevented lactate dehydrogenase leakage without ameliorating ATP depletion. This was accompanied by preservation of cellular ultrastructure and exclusion of vital dyes. SF protection was also shown for ATP-depleted rat hepatocytes. On the other hand, when a key structural motif in the active site of strychnine was chemically blocked, the SF lost its protective effect, establishing strychnine-related specificity for SF protection. Cytoprotective effects of the cell-impermeant strychnine derivative provide compelling evidence suggesting that molecular targets on the outer surface of plasma membranes may mediate cytoprotection by strychnine and glycine. PMID:11238050

  17. Phosphatidylcholine mobility in bile salt depleted rat liver microsomes

    NARCIS (Netherlands)

    Oliveira Filgueiras, O.M. de; Defize, B.; Echteld, C.J.A. van; Bosch, H. van den

    1980-01-01

    Rat liver microsomes prepared by differential centrifugation are known to contain measurable levels of bile salts. More than 90% of these can be removed by passing the microsomal preparation through a Bio-Gel A-150m column. Bile salt depleted microsomes show a high level (> 95%) of mannose-6-phospha

  18. Spearfishing to depletion: evidence from temperate reef fishes in Chile.

    Science.gov (United States)

    Godoy, Natalio; Gelcich, L Stefan; Vásquez, Julio A; Castilla, Juan Carlos

    2010-09-01

    Unreliable and data-poor marine fishery landings can lead to a lack of regulatory action in fisheries management. Here we use official Chilean landing reports and non-conventional indicators, such as fishers' perceptions and spearfishing competition results, to provide evidence of reef fishes depletions caused by unregulated spearfishing. Results show that the three largest and most emblematic reef fishes targeted mainly by spearfishers (> 98% of landings) [Graus nigra (vieja negra), Semicossyphus darwini (sheephead or pejeperro), and Medialuna ancietae (acha)] show signs of depletion in terms of abundance and size and that overall the catches of reef fishes have shifted from large carnivore species toward smaller-sized omnivore and herbivore species. Information from two snorkeling speargun world championships (1971 and 2004, Iquique, Chile) and from fishers' perceptions shows the mean size of reef fish to be declining. Although the ecological consequences of reef fish depletion are not fully understood in Chile, evidence of spearfishing depleting temperate reef fishes must be explicitly included in policy debates. This would involve bans or strong restrictions on the use of SCUBA and hookah diving gear for spearfishing, and minimum size limits. It may also involve academic and policy discussions regarding conservation and fisheries management synergies within networks of no-take and territorial user-rights fisheries areas, as a strategy for the sustainable management of temperate and tropical reef fisheries.

  19. Depletion patterns and dust evolution in the ISM

    CERN Document Server

    Jones, A P

    1999-01-01

    We review the use of elemental depletions in determining the composition of interstellar dust and present a new interpretation of the elemental depletion patterns for the dust forming elements in a range of diffuse cloud types. We discuss this within the context of dust processing in the ISM and show that Si and Mg are selectively eroded from dust, with respect to Fe, as expected for a sputtering erosion process. However, we find that Si is preferentially and non-stoichiometrically eroded from dust with respect to Mg by some as yet unidentified process that may act in conjunction with grain sputtering. On this basis a new way of interpreting the depletions in terms of `continuous' dust processing through erosion in the interstellar medium is presented. The observed depletion patterns can then be understood in terms of a gradually changing grain chemical composition as the erosion of the atoms proceeds non-stoichiometrically in the low-density interstellar medium. The stoichiometric erosion of multicomponent (...

  20. Depletion and the dynamics in colloid-polymer mixtures

    NARCIS (Netherlands)

    Tuinier, Remco; Fan, Tai-Hsi; Taniguchi, Takashi

    The status of work on the influence of nonadsorbing polymers on depletion dynamics in colloidal dispersions is reviewed. In the past focus has been paid to equilibrium properties of colloid-polymer mixtures. In practice the dynamical behaviour is equally important. Dynamic properties including

  1. Glutamine attenuates post-traumatic glutathione depletion in human muscle.

    Science.gov (United States)

    Fläring, U B; Rooyackers, O E; Wernerman, J; Hammarqvist, F

    2003-03-01

    Glutathione is quantitatively the most important endogenous scavenger system. Glutathione depletion in skeletal muscle is pronounced following major trauma and sepsis in intensive care unit patients. Also, following elective surgery, glutathione depletion occurs in parallel with a progressive decline in muscle glutamine concentration. The present study was designed to test the hypothesis that glutamine supplementation may counteract glutathione depletion in a human trauma model. A homogeneous group of patients (n = 17) undergoing a standardized surgical procedure were prospectively randomly allocated to receive glutamine (0.56 g x day(-1) x kg(-1)) or placebo as part of isonitrogenous and isocaloric nutrition. Percutaneous muscle biopsies and blood samples were taken pre-operatively and at 24 and 72 h after surgery. The concentrations of muscle glutathione and related amino acids were determined in muscle tissue and plasma. In the control (unsupplemented) subjects, total muscle glutathione had decreased by 47+/-8% and 37+/-11% and reduced glutathione had decreased by 53+/-10% and 45+/-16% respectively at 24 and 72 h after surgery (P glutamine supplementation attenuates glutathione depletion in skeletal muscle in humans following standardized surgical trauma.

  2. Electric field diagnostics of the dynamics of equatorial density depletions

    Science.gov (United States)

    Laakso, H.; Maynard, N. C.; Pfaff, R. F.; Aggson, T. L.; Coley, W. R.; Janhunen, P.; Herrero, F. A.

    1997-09-01

    During its life of 10 months, the San Marco D satellite crossed a large number of plasma density depletion channels in the nightside F-region equatorial ionosphere. In-situ measurements of vector electric fields from San Marco D reveal convection velocity variations inside such channels and thus can be used as diagnostics of the dynamics of these plasma depleted regions. Furthermore, in some cases, the temporal evolution of the channel can be inferred from the measurements. In this paper the electric field data are converted to plasma drift velocities in order to illustrate cases where the plasma flow is directed upward or downward in the channel, the channel itself is oriented vertically upward or tilted eastward/westward, or the channel is experiencing a bifurcation or pinching-off process. Although the E × B plasma drift velocities within the depleted channels are commonly a few hundred m s-1, on some occasions electric fields corresponding to speeds as large as 2-3 km s-1 have been observed. The implications for such highly supersonic convection are discussed, including the possible constriction of such high-speed depletion channels at higher altitudes.

  3. Depletion studies of two contrasting D-2 reefs

    Energy Technology Data Exchange (ETDEWEB)

    Gillund, G.N.; Patel, C.

    1980-01-01

    The Nisku B and G pools are 2 W. Pembina D-2 pools with contrasting reservoir properties. Average porosity, permeability, and maximum thickness are 5%, 130 md, and 95 m; and 16.4%, 7100 md and 19 m, respectively. The results of the depletion model studies of waterflooding and miscible flooding and some of the problems that occurred during these studies are reviewed.

  4. DIRECT MEASUREMENT OF WEAK DEPLETION FORCE BETWEEN TWO SURFACES*

    Institute of Scientific and Technical Information of China (English)

    Xiang-jun Gong; Xiao-chen Xing; Xiao-ling Wei; To Ngai

    2011-01-01

    In a mixture of colloidal particles and polymer molecules, the particles may experience an attractive “depletion force” if the size of the polymer molecule is larger than the interparticle separation. This is because individual polymer molecules experience less conformational entropy if they stay between the particles than they escape the inter-particle space,which results in an osmotic pressure imbalance inside and outside the gap and leads to interparticle attraction. This depletion force has been the subject of several studies since the 1980s, but the direct measurement of this force is still experimentally challenging as it requires the detection of energy variations of the order of kBT and beyond. We present here our results for applying total internal reflection microscopy (TIRM) to directly measure the interaction between a free-moving particle and a flat surface in solutions consisting of small water-soluble organic molecules or polymeric surfactants. Our results indicate that stable nanobubbles (ca. 150 nm) exist free in the above aqueous solutions. More importantly, the existence of such nanobubbles induces an attraction between the spherical particle and flat surface. Using TIRM, we are able to directly measure such weak interaction with a range up to 100 nm. Furthermore, we demonstrate that by employing thermo-sensitive microgel particles as a depleting agent, we are able to quantitatively measure and reversibly control kBT-scale depletion attraction as function of solution pH.

  5. Apoptosis and T cell depletion during feline infectious peritonitis

    NARCIS (Netherlands)

    Horzinek, M.C.; Haagmans, B.L.; Egberink, H.F.

    1996-01-01

    Cats that have succumbed to feline infectious peritonitis, an immune- mediated disease caused by variants of feline coronaviruses, show apoptosis and T-cell depletion in their lymphoid organs. The ascitic fluid that develops in the course of the condition causes apoptosis in vitro but only in activa

  6. Ozone depletion, related UVB changes and increased skin cancer incidence

    Science.gov (United States)

    Kane, R. P.

    1998-03-01

    Stratospheric ozone at middle latitudes shows a seasonal variation of about +/-20%, a quasi-biennial oscillation of 1-10% range and a long-term variation in which the level was almost steady up to about 1979 and declined thereafter to the present day by about 10%. These variations are expected to be reflected in solar UVB observed at the ground, but in an opposite direction. Thus UVB should have had a long-term increase of about 10-20%, which should cause an increase in skin cancer incidence of about 20-40%. Skin cancer incidence has increased all over the world, e.g. about 90% in USA during 1974-1990. It is popularly believed that this increase in skin cancer incidence is related to the recent ozone depletion. This seems to be incorrect, for two reasons. Firstly, the observed skin cancer increase is too large (90%) compared with the expected value (40%) from ozone depletion. Secondly, cancer does not develop immediately after exposure to solar UVB. The sunburns may occur within hours; but cancer development and detection may take years, even decades. Hence the observed skin cancer increase since 1974 (no data available for earlier periods) must have occurred due to exposure to solar UVB in the 1950s and 1960s, when there was no ozone depletion. Thus, the skin cancer increase must be attributed to harmful solar UVB levels existing even in the 1960s, accentuated later not by ozone depletion (which started only much later, by 1979) but by other causes, such as a longer human life span, better screening, increasing tendencies of sunbathing at beaches, etc., in affluent societies. On the other hand, the recent ozone depletion and the associated UVB increases will certainly take their toll; only that the effects will not be noticed now but years or decades from now. The concern for the future expressed in the Montreal Protocol for reducing ozone depletion by controlling CFC production is certainly justified, especially because increased UVB is harmful to animal and

  7. MCOR - Monte Carlo depletion code for reference LWR calculations

    Energy Technology Data Exchange (ETDEWEB)

    Puente Espel, Federico, E-mail: fup104@psu.edu [Department of Mechanical and Nuclear Engineering, Pennsylvania State University (United States); Tippayakul, Chanatip, E-mail: cut110@psu.edu [Department of Mechanical and Nuclear Engineering, Pennsylvania State University (United States); Ivanov, Kostadin, E-mail: kni1@psu.edu [Department of Mechanical and Nuclear Engineering, Pennsylvania State University (United States); Misu, Stefan, E-mail: Stefan.Misu@areva.com [AREVA, AREVA NP GmbH, Erlangen (Germany)

    2011-04-15

    Research highlights: > Introduction of a reference Monte Carlo based depletion code with extended capabilities. > Verification and validation results for MCOR. > Utilization of MCOR for benchmarking deterministic lattice physics (spectral) codes. - Abstract: The MCOR (MCnp-kORigen) code system is a Monte Carlo based depletion system for reference fuel assembly and core calculations. The MCOR code is designed as an interfacing code that provides depletion capability to the LANL Monte Carlo code by coupling two codes: MCNP5 with the AREVA NP depletion code, KORIGEN. The physical quality of both codes is unchanged. The MCOR code system has been maintained and continuously enhanced since it was initially developed and validated. The verification of the coupling was made by evaluating the MCOR code against similar sophisticated code systems like MONTEBURNS, OCTOPUS and TRIPOLI-PEPIN. After its validation, the MCOR code has been further improved with important features. The MCOR code presents several valuable capabilities such as: (a) a predictor-corrector depletion algorithm, (b) utilization of KORIGEN as the depletion module, (c) individual depletion calculation of each burnup zone (no burnup zone grouping is required, which is particularly important for the modeling of gadolinium rings), and (d) on-line burnup cross-section generation by the Monte Carlo calculation for 88 isotopes and usage of the KORIGEN libraries for PWR and BWR typical spectra for the remaining isotopes. Besides the just mentioned capabilities, the MCOR code newest enhancements focus on the possibility of executing the MCNP5 calculation in sequential or parallel mode, a user-friendly automatic re-start capability, a modification of the burnup step size evaluation, and a post-processor and test-matrix, just to name the most important. The article describes the capabilities of the MCOR code system; from its design and development to its latest improvements and further ameliorations. Additionally

  8. Two-dimensional analytical models for asymmetric fully depleted double-gate strained silicon MOSFETs

    Institute of Scientific and Technical Information of China (English)

    Liu Hong-Xia; Li Jin; Li Bin; Cao Lei; Yuan Bo

    2011-01-01

    This paper develops the simple and accurate two-dimensional analytical models for new asymmetric double-gate fully depleted strained-Si MOSFET. The models mainly include the analytical equations of the surface potential, surface electric field and threshold voltage, which are derived by solving two dimensional Poisson equation in strained-Si layer.The models are verified by numerical simulation. Besides offering the physical insight into device physics in the model,the new structure also provides the basic designing guidance for further immunity of short channel effect and drain-induced barrier-lowering of CMOS-based devices in nanometre scale.

  9. STED microscopy--super-resolution bio-imaging utilizing a stimulated emission depletion.

    Science.gov (United States)

    Otomo, Kohei; Hibi, Terumasa; Kozawa, Yuichi; Nemoto, Tomomi

    2015-08-01

    One of the most popular super-resolution microscopies that breaks the diffraction barrier is stimulated emission depletion (STED) microscopy. As the optical set-up of STED microscopy is based on a laser scanning microscopy (LSM) system, it potentially has several merits of LSM like confocal or two-photon excitation LSM. In this article, we first describe the principles of STED microscopy and then describe the features of our newly developed two-photon excitation STED microscopy. On the basis of our recent results and those of other researchers, we conclude by discussing future research and new technologies in this field.

  10. Replacement of ozone depleting and toxic chemicals in gravimetric analysis of non-volatile residue

    Science.gov (United States)

    Arnold, G. S.; Uht, J. C.; Sinsheimer, F. B.

    1995-01-01

    The standard tests for determining nonvolatile residue accretion on spacecraft surfaces and in clean processing facilities rely on the use of halogenated solvents that are targeted for elimination because of their toxic or ozone-depleting natures. This paper presents a literature-based screening survey for candidate replacement solvents. Potential replacements were evaluated for their vapor pressure, toxicity, and solvent properties. Three likely candidates were identified: ethyl acetate, methyl acetate, and acetone. Laboratory tests are presented that evaluate the suitability of these candidate replacement solvents.

  11. Fundamental differences between Arctic and Antarctic ozone depletion.

    Science.gov (United States)

    Solomon, Susan; Haskins, Jessica; Ivy, Diane J; Min, Flora

    2014-04-29

    Antarctic ozone depletion is associated with enhanced chlorine from anthropogenic chlorofluorocarbons and heterogeneous chemistry under cold conditions. The deep Antarctic "hole" contrasts with the generally weaker depletions observed in the warmer Arctic. An unusually cold Arctic stratospheric season occurred in 2011, raising the question of how the Arctic ozone chemistry in that year compares with others. We show that the averaged depletions near 20 km across the cold part of each pole are deeper in Antarctica than in the Arctic for all years, although 2011 Arctic values do rival those seen in less-depleted years in Antarctica. We focus not only on averages but also on extremes, to address whether or not Arctic ozone depletion can be as extreme as that observed in the Antarctic. This information provides unique insights into the contrasts between Arctic and Antarctic ozone chemistry. We show that extreme Antarctic ozone minima fall to or below 0.1 parts per million by volume (ppmv) at 18 and 20 km (about 70 and 50 mbar) whereas the lowest Arctic ozone values are about 0.5 ppmv at these altitudes. At a higher altitude of 24 km (30-mbar level), no Arctic data below about 2 ppmv have been observed, including in 2011, in contrast to values more than an order of magnitude lower in Antarctica. The data show that the lowest ozone values are associated with temperatures below -80 °C to -85 °C depending upon altitude, and are closely associated with reduced gaseous nitric acid concentrations due to uptake and/or sedimentation in polar stratospheric cloud particles.

  12. Depleted uranium hexafluoride: The source material for advanced shielding systems

    Energy Technology Data Exchange (ETDEWEB)

    Quapp, W.J.; Lessing, P.A. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Cooley, C.R. [Department of Technology, Germantown, MD (United States)

    1997-02-01

    The U.S. Department of Energy (DOE) has a management challenge and financial liability problem in the form of 50,000 cylinders containing 555,000 metric tons of depleted uranium hexafluoride (UF{sub 6}) that are stored at the gaseous diffusion plants. DOE is evaluating several options for the disposition of this UF{sub 6}, including continued storage, disposal, and recycle into a product. Based on studies conducted to date, the most feasible recycle option for the depleted uranium is shielding in low-level waste, spent nuclear fuel, or vitrified high-level waste containers. Estimates for the cost of disposal, using existing technologies, range between $3.8 and $11.3 billion depending on factors such as the disposal site and the applicability of the Resource Conservation and Recovery Act (RCRA). Advanced technologies can reduce these costs, but UF{sub 6} disposal still represents large future costs. This paper describes an application for depleted uranium in which depleted uranium hexafluoride is converted into an oxide and then into a heavy aggregate. The heavy uranium aggregate is combined with conventional concrete materials to form an ultra high density concrete, DUCRETE, weighing more than 400 lb/ft{sup 3}. DUCRETE can be used as shielding in spent nuclear fuel/high-level waste casks at a cost comparable to the lower of the disposal cost estimates. Consequently, the case can be made that DUCRETE shielded casks are an alternative to disposal. In this case, a beneficial long term solution is attained for much less than the combined cost of independently providing shielded casks and disposing of the depleted uranium. Furthermore, if disposal is avoided, the political problems associated with selection of a disposal location are also avoided. Other studies have also shown cost benefits for low level waste shielded disposal containers.

  13. Repository criticality control for {sup 233}U using depleted uranium

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C.W.; Elam, K.R.; Hopper, C.M.

    1999-07-01

    The US is evaluating methods for the disposition of excess weapons-usable {sup 233}U, including disposal in a repository. Isotopic dilution studies were undertaken to determine how much depleted uranium (DU) would need to be added to the {sup 233}U to minimize the potential for nuclear criticality in a repository. Numerical evaluations were conducted to determine the nuclear equivalence of different {sup 235}U enrichments to {sup 233}U isotopically diluted with DU containing 0.2 wt% {sup 235}U. A homogeneous system of silicon dioxide, water, {sup 233}U, and DU, in which the ratio of each component was varied, was used to determine the conditions of maximum nuclear reactivity. In terms of preventing nuclear criticality in a repository, there are three important limits from these calculations. 1. Criticality safe in any nonnuclear system: The required isotopic dilution to ensure criticality under all conditions, except in the presence of man-made nuclear materials (beryllium, etc.), is {approximately}1.0% {sup 235}U in {sup 238}U. The equivalent {sup 233}U enrichment level is 0.53 wt% {sup 233}U in DU. 2. Critically safe in natural systems: The lowest {sup 235}U enrichment found in a natural reactor at shutdown was {approximately}1.3%. French studies, based on the characteristics of natural uranium ore bodies, indicate that a minimum enrichment of {approximately}1.28% {sup 235}U is required for criticality. These data suggest that nuclear criticality from migrating uranium is not realistic unless the {sup 235}U enrichments exceed {approximately}1.3%, which is a result that is equivalent to 0.72% {sup 233}U in DU. 3. Criticality safety equivalent to light water reactor (LWR) spent nuclear fuel (SNF): The {sup 233}U can be diluted with DU so that the uranium criticality characteristics match SNF uranium. Whatever repository criticality controls are used for SNF can then be used for {sup 233}U. The average LWR SNF assay (after decay of plutonium isotopes to uranium

  14. Arginine depletion by arginine deiminase does not affect whole protein metabolism or muscle fractional protein synthesis rate in mice.

    Directory of Open Access Journals (Sweden)

    Juan C Marini

    Full Text Available Due to the absolute need for arginine that certain cancer cells have, arginine depletion is a therapy in clinical trials to treat several types of cancers. Arginine is an amino acids utilized not only as a precursor for other important molecules, but also for protein synthesis. Because arginine depletion can potentially exacerbate the progressive loss of body weight, and especially lean body mass, in cancer patients we determined the effect of arginine depletion by pegylated arginine deiminase (ADI-PEG 20 on whole body protein synthesis and fractional protein synthesis rate in multiple tissues of mice. ADI-PEG 20 successfully depleted circulating arginine (<1 μmol/L, and increased citrulline concentration more than tenfold. Body weight and body composition, however, were not affected by ADI-PEG 20. Despite the depletion of arginine, whole body protein synthesis and breakdown were maintained in the ADI-PEG 20 treated mice. The fractional protein synthesis rate of muscle was also not affected by arginine depletion. Most tissues (liver, kidney, spleen, heart, lungs, stomach, small and large intestine, pancreas were able to maintain their fractional protein synthesis rate; however, the fractional protein synthesis rate of brain, thymus and testicles was reduced due to the ADI-PEG 20 treatment. Furthermore, these results were confirmed by the incorporation of ureido [14C]citrulline, which indicate the local conversion into arginine, into protein. In conclusion, the intracellular recycling pathway of citrulline is able to provide enough arginine to maintain protein synthesis rate and prevent the loss of lean body mass and body weight.

  15. Evaluation of acute tryptophan depletion and sham depletion with a gelatin-based collagen peptide protein mixture

    DEFF Research Database (Denmark)

    Stenbæk, D S; Einarsdottir, H S; Goregliad-Fjaellingsdal, T

    2016-01-01

    Acute Tryptophan Depletion (ATD) is a dietary method used to modulate central 5-HT to study the effects of temporarily reduced 5-HT synthesis. The aim of this study is to evaluate a novel method of ATD using a gelatin-based collagen peptide (CP) mixture. We administered CP-Trp or CP+Trp mixtures...

  16. Impact of subjacent rocks at the water and air regime of the depleted peat deposits

    Science.gov (United States)

    Rakovich, V. A.

    2009-04-01

    At the depleted peat deposits (after peat extraction), where the residual layer of peat with the thickness of about 0,5 meters is laid at the well water permeable rocks, vegetation typical for dry conditions is developed in case of good drainage conditions; birch trees, willow, alder-trees and buckthorn prevail in this vegetation. Water and air regime is characterized here by good aeration with prevailing of oxidative processes. If water regime is regulated, these depleted peat areas are suitable for agricultural and forest lands; however, necessity of transformation of these depleted lands into forest and agricultural lands must be ecologically and economically justified. If the residual layer of peat with the thickness of 0,05-0,3 m is based at the sapropel or peat sapropel, contrast amphibiotic water and air regime with strong fluctuation of oxidative and restoration process depending on the weather conditions is formed; this regime is formed without artificial increase of the ground waters level. This does not allow bog vegetation or vegetation typical for dry conditions to develop. Thus, within 20 and more years after completion of peat extraction, such areas are not covered by vegetation in spite of favorable agro-chemical qualities of peat layer and favorable for vegetation chemical composition of soil and ground waters. Depleted peat deposits, that are based at the sapropel, are not suitable for agricultural use, because agricultural vegetation requires stable water and air regime with good aeration and oxidative and restoration potential within 400-750 mV. Contrast amphibiotic water and air regime of the depleted peat deposits that are based at sapropel excludes possibility to use them as agricultural lands. Because of this reason, areas with residual peat layer that are based at sapropel are not suitable for forest planting. Due to periodic increase of ground waters level, rot systems of the plants can not penetrate into the required depth, and mechanical

  17. Depletion effects in smectic phases of hard-rod-hard-sphere mixtures.

    Science.gov (United States)

    Martínez-Ratón, Y; Cinacchi, G; Velasco, E; Mederos, L

    2006-10-01

    It is known that when hard spheres are added to a pure system of hard rods the stability of the smectic phase may be greatly enhanced, and that this effect can be rationalised in terms of depletion forces. In the present paper we first study the effect of orientational order on depletion forces in this particular binary system, comparing our results with those obtained adopting the usual approximation of considering the rods parallel and their orientations frozen. We consider mixtures with rods of different aspect ratios and spheres of different diameters, and we treat them within Onsager theory. Our results indicate that depletion effects, and consequently smectic stability, decrease significantly as a result of orientational disorder in the smectic phase when compared with corresponding data based on the frozen-orientation approximation. These results are discussed in terms of the tau parameter, which has been proposed as a convenient measure of depletion strength. We present closed expressions for tau, and show that it is intimately connected with the depletion potential. We then analyse the effect of particle geometry by comparing results pertaining to systems of parallel rods of different shapes (spherocylinders, cylinders and parallelepipeds). We finally provide results based on the Zwanzig approximation of a fundamental-measure density-functional theory applied to mixtures of parallelepipeds and cubes of different sizes. In this case, we show that the tau parameter exhibits a linear asymptotic behaviour in the limit of large values of the hard-rod aspect ratio, in conformity with Onsager theory, as well as in the limit of large values of the ratio of rod breadth to cube side length, d, in contrast to Onsager approximation, which predicts tau approximately d (3). Based on both this result and the Percus-Yevick approximation for the direct correlation function for a hard-sphere binary mixture in the same limit of infinite asymmetry, we speculate that, for

  18. Sedimentation rapidly induces an immune response and depletes energy stores in a hard coral

    Science.gov (United States)

    Sheridan, C.; Grosjean, Ph.; Leblud, J.; Palmer, C. V.; Kushmaro, A.; Eeckhaut, I.

    2014-12-01

    High sedimentation rates have been linked to reduced coral health within multiple systems; however, whether this is a direct result of compromised coral immunity has not been previously investigated. The potential effects of sedimentation on immunity of the hard coral Montipora patula were examined by comparing physiological responses of coral fragments inoculated with sterilized marine sediments and those under control conditions. Sediments were collected from terrestrial runoff-affected reefs in SW Madagascar and applied cyclically for a total of 24 h at a rate observed during precipitation-induced sedimentation events. Coral health was determined 24 h after the onset of the sedimentation stress through measuring metabolic proxies of O2 budget and lipid ratios. Immune response of the melanin synthesis pathway was measured by quantifying phenoloxidase activity and melanin deposits. Sedimentation induced both immune and metabolic responses in M. patula. Both phenoloxidase activity and melanin deposition were significantly higher in the sediment treatment compared to controls, indicating an induced immune response. Sediment-treated corals also showed a tendency towards increased respiration (during the night) and decreased photosynthesis (during the day) and a significant depletion of energy reserves as compared to controls. These data highlight that short-term (24 h) sedimentation, free of live microorganisms, compromises the health of M. patula. The energetically costly immune response, potentially elicited by residual endotoxins and other inflammatory particles associated with the sterile sediments, likely contributes to the energy depletion. Overall, exposure to sedimentation adversely affects coral health and continued exposure may lead to resource depletion and an increased susceptibility to disease.

  19. CRDIAC: Coupled Reactor Depletion Instrument with Automated Control

    Energy Technology Data Exchange (ETDEWEB)

    Steven K. Logan

    2012-08-01

    When modeling the behavior of a nuclear reactor over time, it is important to understand how the isotopes in the reactor will change, or transmute, over that time. This is especially important in the reactor fuel itself. Many nuclear physics modeling codes model how particles interact in the system, but do not model this over time. Thus, another code is used in conjunction with the nuclear physics code to accomplish this. In our code, Monte Carlo N-Particle (MCNP) codes and the Multi Reactor Transmutation Analysis Utility (MRTAU) were chosen as the codes to use. In this way, MCNP would produce the reaction rates in the different isotopes present and MRTAU would use cross sections generated from these reaction rates to determine how the mass of each isotope is lost or gained. Between these two codes, the information must be altered and edited for use. For this, a Python 2.7 script was developed to aid the user in getting the information in the correct forms. This newly developed methodology was called the Coupled Reactor Depletion Instrument with Automated Controls (CRDIAC). As is the case in any newly developed methodology for modeling of physical phenomena, CRDIAC needed to be verified against similar methodology and validated against data taken from an experiment, in our case AFIP-3. AFIP-3 was a reduced enrichment plate type fuel tested in the ATR. We verified our methodology against the MCNP Coupled with ORIGEN2 (MCWO) method and validated our work against the Post Irradiation Examination (PIE) data. When compared to MCWO, the difference in concentration of U-235 throughout Cycle 144A was about 1%. When compared to the PIE data, the average bias for end of life U-235 concentration was about 2%. These results from CRDIAC therefore agree with the MCWO and PIE data, validating and verifying CRDIAC. CRDIAC provides an alternative to using ORIGEN-based methodology, which is useful because CRDIAC's depletion code, MRTAU, uses every available isotope in its

  20. High pressure elasticity and thermal properties of depleted uranium

    Science.gov (United States)

    Jacobsen, M. K.; Velisavljevic, N.

    2016-04-01

    Studies of the phase diagram of uranium have revealed a wealth of high pressure and temperature phases. Under ambient conditions the crystal structure is well defined up to 100 gigapascals (GPa), but very little information on thermal conduction or elasticity is available over this same range. This work has applied ultrasonic interferometry to determine the elasticity, mechanical, and thermal properties of depleted uranium to 4.5 GPa. Results show general strengthening with applied load, including an overall increase in acoustic thermal conductivity. Further implications are discussed within. This work presents the first high pressure studies of the elasticity and thermal properties of depleted uranium metal and the first real-world application of a previously developed containment system for making such measurements.