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Sample records for oxide depletion dyspnoea

  1. Inhomogeneous depletion of oxygen ions in metal oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    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.

  2. Depletion effect of oxide semiconductor analyzed by Hall effects.

    PubMed

    Oh, Teresa

    2014-12-01

    This letter discusses the tunneling behavior of amorphous indium-gallium-zinc-oxide (a-IGZO) analyzed through the observation of its Hall effects. The properties of the a-IGZO changed from those of a majority carrier to those of a minority carrier after the annealing process as a result of the electron-hole recombination due to the thermal activation energy and the formation of a depletion layer with a high-potential Schottky barrier. Therefore, the diffusion current of these minority charge carriers caused ambipolar transfer characteristics, a tunneling behavior, in the metal-oxide semiconductor (MOS) transistor. PMID:25971008

  3. Cough, pain and dyspnoea: similarities and differences

    PubMed Central

    Gracely, Richard H; Undem, Bradley J; Banzett, Robert B

    2007-01-01

    The three common symptoms, pain, dyspnoea and cough, share some important features. We felt that the analogies to be made among them could be instructive, possibly suggesting new avenues of research. Each of these symptoms can be profoundly uncomfortable, and can profoundly degrade quality of life. The sign, cough, is often given more prominence than the symptom, urge to cough, but both are important to the patient (the former is of more concern to nearby people). Advances in pain research over the last several decades have pointed the way to new studies of dyspnoea; they may serve as a model for the psychophysical study of the perception of urge to cough, as well as providing models for understanding both central and peripheral sensitization of the afferent pathway. We briefly review here the afferent and central pathways and psychophysics of pain, dyspnoea and urge to cough. PMID:17336558

  4. Linkages between ozone-depleting substances, tropospheric oxidation and aerosols

    NASA Astrophysics Data System (ADS)

    Voulgarakis, A.; Shindell, D. T.; Faluvegi, G.

    2013-05-01

    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 individual historical radiative forcings of CFCs and N2O through their indirect effects on methane (-22.6 mW m-2 for CFCs and -6.7 mW m-2 for N2O) and sulfate aerosols (-3.0 mW m-2 for CFCs and +6.5 mW m-2 for N2O when considering the direct aerosol effect) discussed here are non-negligible when compared to known historical ODS 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.

  5. Linkages Between Ozone-depleting Substances, Tropospheric Oxidation and Aerosols

    NASA Technical Reports Server (NTRS)

    Voulgarakis, A.; Shindell, D. T.; Faluvegi, G.

    2013-01-01

    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 individual historical radiative forcings of CFCs and N2O through their indirect effects on methane (-22.6mW/sq. m for CFCs and -6.7mW/sq. m for N2O) and sulfate aerosols (-3.0mW/sq. m for CFCs and +6.5mW/sq. m for N2O when considering the direct aerosol effect) discussed here are non-negligible when compared to known historical ODS 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.

  6. Depletion of Vandium in Planetary Mantles: Controlled by Metal, Oxide, or Silicate?

    NASA Technical Reports Server (NTRS)

    Righter, Kevin

    2006-01-01

    Vanadium concentrations in planetary mantles can provide information about the conditions during early accretion and differentiation. Because V is a slightly siderophile element, it is usually assumed that any depletion would be due to core formation and metal-silicate equilibrium. However, V is typically more compatible in phases such as spinel, magnesiowuestite and garnet. Fractionation of all of these phases would cause depletions more marked than those from metal. In this paper consideration of depletions due to metal, oxide and silicate are critically evaluated.

  7. Nitrous Oxide: A Greenhouse Gas That is Also an Ozone Layer Depleting Gas

    NASA Astrophysics Data System (ADS)

    Reed, S.; Uriarte, M.; Wood, T. E.; Cavaleri, M. A.; Lugo, A. E.

    2014-12-01

    Nitrous oxide, N2O, is the major source of nitrogen oxides in the stratosphere, where these oxides playa critical roles in ozone layer depletion by itself and moderating ozone layer depletion by chlorinated chemicals. Thus N2O plays a complex role in the stratosphere. Nitrous oxide is also a greenhouse gas and it contributes to the radiative forcing of climate. Indeed, it is considered the third most important greenhouse gas next to carbon dioxide and methane. This dual role of nitrous oxide makes it an interesting gas for the atmosphere- it bridges the issue of ozone layer depletion and climate change. Nitrous oxide has both natural and anthropogenic sources. Therefore, one needs to consider this important distinction between natural and anthropogenic sources as well as its role in two related but separate environmental issues. Further, the sources of nitrous oxide are varied and diffuse, which makes it difficult to quantify different sources. However, it is clear that a majority of anthropogenic nitrous oxide comes from food production (including agricultural and animal growth practices), an activity that is at the heart of human existence. Thus, limiting N2O emissions is not a simple task! I will briefly summarize our understanding of these roles of nitrous oxide in the earth's atmosphere and touch on the possible ways to limit N2O emissions.

  8. Nitrous Oxide: A Greenhouse Gas That is Also an Ozone Layer Depleting Gas

    NASA Astrophysics Data System (ADS)

    Ravishankara, A. R.

    2015-12-01

    Nitrous oxide, N2O, is the major source of nitrogen oxides in the stratosphere, where these oxides playa critical roles in ozone layer depletion by itself and moderating ozone layer depletion by chlorinated chemicals. Thus N2O plays a complex role in the stratosphere. Nitrous oxide is also a greenhouse gas and it contributes to the radiative forcing of climate. Indeed, it is considered the third most important greenhouse gas next to carbon dioxide and methane. This dual role of nitrous oxide makes it an interesting gas for the atmosphere- it bridges the issue of ozone layer depletion and climate change. Nitrous oxide has both natural and anthropogenic sources. Therefore, one needs to consider this important distinction between natural and anthropogenic sources as well as its role in two related but separate environmental issues. Further, the sources of nitrous oxide are varied and diffuse, which makes it difficult to quantify different sources. However, it is clear that a majority of anthropogenic nitrous oxide comes from food production (including agricultural and animal growth practices), an activity that is at the heart of human existence. Thus, limiting N2O emissions is not a simple task! I will briefly summarize our understanding of these roles of nitrous oxide in the earth's atmosphere and touch on the possible ways to limit N2O emissions.

  9. Extreme (13)C depletion of carbonates formed during oxidation of biogenic methane in fractured granite.

    PubMed

    Drake, Henrik; Åström, Mats E; Heim, Christine; Broman, Curt; Åström, Jan; Whitehouse, Martin; Ivarsson, Magnus; Siljeström, Sandra; Sjövall, Peter

    2015-01-01

    Precipitation of exceptionally 13C-depleted authigenic carbonate is a result of, and thus a tracer for, sulphate-dependent anaerobic methane oxidation, particularly in marine sediments. Although these carbonates typically are less depleted in 13C than in the source methane, because of incorporation of C also from other sources, they are far more depleted in 13C (δ13C as light as -69‰ V-PDB) than in carbonates formed where no methane is involved. Here we show that oxidation of biogenic methane in carbon-poor deep groundwater in fractured granitoid rocks has resulted in fracture-wall precipitation of the most extremely 13C-depleted carbonates ever reported, δ13C down to -125‰ V-PDB. A microbial consortium of sulphate reducers and methane oxidizers has been involved, as revealed by biomarker signatures in the carbonates and S-isotope compositions of co-genetic sulphide. Methane formed at shallow depths has been oxidized at several hundred metres depth at the transition to a deep-seated sulphate-rich saline water. This process is so far an unrecognized terrestrial sink of methane. PMID:25948095

  10. Extreme (13)C depletion of carbonates formed during oxidation of biogenic methane in fractured granite.

    PubMed

    Drake, Henrik; Åström, Mats E; Heim, Christine; Broman, Curt; Åström, Jan; Whitehouse, Martin; Ivarsson, Magnus; Siljeström, Sandra; Sjövall, Peter

    2015-05-07

    Precipitation of exceptionally 13C-depleted authigenic carbonate is a result of, and thus a tracer for, sulphate-dependent anaerobic methane oxidation, particularly in marine sediments. Although these carbonates typically are less depleted in 13C than in the source methane, because of incorporation of C also from other sources, they are far more depleted in 13C (δ13C as light as -69‰ V-PDB) than in carbonates formed where no methane is involved. Here we show that oxidation of biogenic methane in carbon-poor deep groundwater in fractured granitoid rocks has resulted in fracture-wall precipitation of the most extremely 13C-depleted carbonates ever reported, δ13C down to -125‰ V-PDB. A microbial consortium of sulphate reducers and methane oxidizers has been involved, as revealed by biomarker signatures in the carbonates and S-isotope compositions of co-genetic sulphide. Methane formed at shallow depths has been oxidized at several hundred metres depth at the transition to a deep-seated sulphate-rich saline water. This process is so far an unrecognized terrestrial sink of methane.

  11. Extreme 13C depletion of carbonates formed during oxidation of biogenic methane in fractured granite

    PubMed Central

    Drake, Henrik; Åström, Mats E.; Heim, Christine; Broman, Curt; Åström, Jan; Whitehouse, Martin; Ivarsson, Magnus; Siljeström, Sandra; Sjövall, Peter

    2015-01-01

    Precipitation of exceptionally 13C-depleted authigenic carbonate is a result of, and thus a tracer for, sulphate-dependent anaerobic methane oxidation, particularly in marine sediments. Although these carbonates typically are less depleted in 13C than in the source methane, because of incorporation of C also from other sources, they are far more depleted in 13C (δ13C as light as −69‰ V-PDB) than in carbonates formed where no methane is involved. Here we show that oxidation of biogenic methane in carbon-poor deep groundwater in fractured granitoid rocks has resulted in fracture-wall precipitation of the most extremely 13C-depleted carbonates ever reported, δ13C down to −125‰ V-PDB. A microbial consortium of sulphate reducers and methane oxidizers has been involved, as revealed by biomarker signatures in the carbonates and S-isotope compositions of co-genetic sulphide. Methane formed at shallow depths has been oxidized at several hundred metres depth at the transition to a deep-seated sulphate-rich saline water. This process is so far an unrecognized terrestrial sink of methane. PMID:25948095

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

    PubMed

    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.

  13. Air-pressure tunable depletion width, rectification behavior, and charge conduction in oxide nanotubes.

    PubMed

    Alivov, Yahya; Funke, Hans H; Singh, Vivek; Nagpal, Prashant

    2015-02-01

    Metal-oxide nanotubes provide large surface areas and functionalizable surfaces for a variety of optical and electronic applications. Here we report air-tunable rectifying behavior, depletion width modulation, and two-dimensional (2D) charge conduction in hollow titanium-dioxide nanotubes. The metal contact forms a Schottky-diode in the nanotubes, and the rectification factor (on/off ratio) can be varied by more than 3 orders of magnitude (1-2 × 10(3)) as the air pressure is increased from 2 mTorr to atmospheric pressure. This behavior is explained using a change in depletion width of these thin nanotubes by adsorption of water vapor on both surfaces of a hollow nanotube, and the resulting formation of a metal-insulator-semiconductor (MIS) junction, which controls the 2D charge conduction properties in thin oxide nanotubes.

  14. Comparison of two lung clearance models based on the dissolution rates of oxidized depleted uranium

    SciTech Connect

    Crist, K.C.

    1984-10-01

    An in-vitro dissolution study was conducted on two respirable oxidized depleted uranium samples. The dissolution rates generated from this study were then utilized in the International Commission on Radiological Protection Task Group lung clearance model and a lung clearance model proposed by Cuddihy. Predictions from both models based on the dissolution rates of the amount of oxidized depleted uranium that would be cleared to blood from the pulmonary region following an inhalation exposure were compared. It was found that the predictions made by both models differed considerably. The difference between the predictions was attributed to the differences in the way each model perceives the clearance from the pulmonary region. 33 references, 11 figures, 9 tables.

  15. Glutathione depletion due to copper-induced phytochelatin synthesis causes oxidative stress in Silene cucubalus

    SciTech Connect

    Ric De Vos, C.H.; Vonk, M.J.; Vooijs, R.; Schat, H. )

    1992-03-01

    The relation between loss of glutathione due to metal-induced phytochelatin synthesis and oxidative stress was studied in the roots of copper-sensitive and tolerant Silene cucubalus (L.) Wib., resistant to 1 and 40 micromolar Cu, respectively. The amount of nonprotein sulfhydryl compounds other then glutathione was taken as a measure of phytochelatins. At a supply of 20 micromolar Cu, which is toxic for sensitive plants only, phytochelatin synthesis and loss of total glutathione were observed only in sensitive plants within 6 h of exposure. When the plants were exposed to a range of copper concentrations for 3 d, a marked production of phytochelatins in sensitive plants was already observed at 0.5 micromolar Cu, whereas the production in tolerant plants was negligible at 40 micromolar or lower. The highest production in tolerant plants was only 40% of that in sensitive plants. In both varieties, the synthesis of phytochelatins was coupled to a loss of glutathione. Copper at toxic concentrations caused oxidative stress, as was evidenced by both the accumulation of lipid peroxidation products and a shift in the glutathione redox couple to a more oxidized state. Depletion of glutathione by pretreatment with buthionine sulfoximine significantly increased the oxidative damage by copper. At a comparably low glutathione level, cadmium had no effect on either lipid peroxidation or the glutathione redox couple in buthionine sulfoximine-treated plants. These results indicate that copper may specifically cause oxidative stress by depletion of the antioxidant glutathione due to phytochelatin synthesis.

  16. Oxidation of depleted uranium penetrators and aerosol dispersal at high temperatures

    SciTech Connect

    Elder, J.C.; Tinkle, M.C.

    1980-12-01

    Aerosols dispersed from depleted uranium penetrators exposed to air and air-CO/sub 2/ mixtures at temperatures ranging from 500 to 1000/sup 0/C for 2- or 4-h periods were characterized. These experiments indicated dispersal of low concentrations of aerosols in the respirable size range (typically <10/sup -3/% of penetrator mass at 223 cm/s (5 mph) windspeed). Oxidation was maximum at 700/sup 0/C in air and 800/sup 0/C in 50% air-50% CO/sub 2/, indicating some self-protection developed at higher temperatures. No evidence of self-sustained burning was observed, although complete oxidation can be expected in fires significantly exceeding 4 h, the longest exposure of this series. An outdoor burning experiment using 10 batches of pine wood and paper packing material as fuel caused the highest oxidation rate, probably accelerated by disruption of the oxide layer accompanying broad temperature fluctuation as each fuel batch was added.

  17. Mechanisms of exertional dyspnoea in symptomatic smokers without COPD.

    PubMed

    Elbehairy, Amany F; Guenette, Jordan A; Faisal, Azmy; Ciavaglia, Casey E; Webb, Katherine A; Jensen, Dennis; Ramsook, Andrew H; Neder, J Alberto; O'Donnell, Denis E

    2016-09-01

    Dyspnoea and activity limitation can occur in smokers who do not meet spirometric criteria for chronic obstructive pulmonary disease (COPD) but the underlying mechanisms are unknown.Detailed pulmonary function tests and sensory-mechanical relationships during incremental exercise with respiratory pressure measurements and diaphragmatic electromyography (EMGdi) were compared in 20 smokers without spirometric COPD and 20 age-matched healthy controls.Smokers (mean±sd post-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity 75±4%, mean±sd FEV1 104±14% predicted) had greater activity-related dyspnoea, poorer health status and lower physical activity than controls. Smokers had peripheral airway dysfunction: higher phase-III nitrogen slopes (3.8±1.8 versus 2.6±1.1%·L(-1)) and airway resistance (difference between airway resistance measured at 5 Hz and 20 Hz 19±11 versus 12±7% at 5 Hz) than controls (p<0.05). Smokers had significantly (p<0.05) lower peak oxygen uptake (78±40 versus 107±45% predicted) and ventilation (61±26 versus 97±29 L·min(-1)). Exercise ventilatory requirements, operating lung volumes and cardio-circulatory responses were similar. However, submaximal dyspnoea ratings, resistive and total work of breathing were increased in smokers compared with controls (p<0.05); diaphragmatic effort (transdiaphragmatic pressure/maximumal transdiaphragmatic pressure) and fractional inspiratory neural drive to the diaphragm (EMGdi/maximal EMGdi) were also increased (p<0.05) mainly reflecting the reduced denominator.Symptomatic smokers at risk for COPD had greater exertional dyspnoea and lower exercise tolerance compared with healthy controls in association with greater airways resistance, contractile diaphragmatic effort and fractional inspiratory neural drive to the diaphragm. PMID:27492828

  18. Heterogeneous OH oxidation of motor oil particles causes selective depletion of branched and less cyclic hydrocarbons.

    PubMed

    Isaacman, Gabriel; Chan, Arthur W H; Nah, Theodora; Worton, David R; Ruehl, Chris R; Wilson, Kevin R; Goldstein, Allen H

    2012-10-01

    Motor oil serves as a useful model system for atmospheric oxidation of hydrocarbon mixtures typical of anthropogenic atmospheric particulate matter, but its complexity often prevents comprehensive chemical speciation. In this work we fully characterize this formerly "unresolved complex mixture" at the molecular level using recently developed soft ionization gas chromatography techniques. Nucleated motor oil particles are oxidized in a flow tube reactor to investigate the relative reaction rates of observed hydrocarbon classes: alkanes, cycloalkanes, bicycloalkanes, tricycloalkanes, and steranes. Oxidation of hydrocarbons in a complex aerosol is found to be efficient, with approximately three-quarters (0.72 ± 0.06) of OH collisions yielding a reaction. Reaction rates of individual hydrocarbons are structurally dependent: compared to normal alkanes, reaction rates increased by 20-50% with branching, while rates decreased ∼20% per nonaromatic ring present. These differences in rates are expected to alter particle composition as a function of oxidation, with depletion of branched and enrichment of cyclic hydrocarbons. Due to this expected shift toward ring-opening reactions heterogeneous oxidation of the unreacted hydrocarbon mixture is less likely to proceed through fragmentation pathways in more oxidized particles. Based on the observed oxidation-induced changes in composition, isomer-resolved analysis has potential utility for determining the photochemical age of atmospheric particulate matter with respect to heterogeneous oxidation.

  19. Palmitate induces ER calcium depletion and apoptosis in mouse podocytes subsequent to mitochondrial oxidative stress

    PubMed Central

    Xu, S; Nam, S M; Kim, J-H; Das, R; Choi, S-K; Nguyen, T T; Quan, X; Choi, S J; Chung, C H; Lee, E Y; Lee, I-K; Wiederkehr, A; Wollheim, C B; Cha, S-K; Park, K-S

    2015-01-01

    Pathologic alterations in podocytes lead to failure of an essential component of the glomerular filtration barrier and proteinuria in chronic kidney diseases. Elevated levels of saturated free fatty acid (FFA) are harmful to various tissues, implemented in the progression of diabetes and its complications such as proteinuria in diabetic nephropathy. Here, we investigated the molecular mechanism of palmitate cytotoxicity in cultured mouse podocytes. Incubation with palmitate dose-dependently increased cytosolic and mitochondrial reactive oxygen species, depolarized the mitochondrial membrane potential, impaired ATP synthesis and elicited apoptotic cell death. Palmitate not only evoked mitochondrial fragmentation but also caused marked dilation of the endoplasmic reticulum (ER). Consistently, palmitate upregulated ER stress proteins, oligomerized stromal interaction molecule 1 (STIM1) in the subplasmalemmal ER membrane, abolished the cyclopiazonic acid-induced cytosolic Ca2+ increase due to depletion of luminal ER Ca2+. Palmitate-induced ER Ca2+ depletion and cytotoxicity were blocked by a selective inhibitor of the fatty-acid transporter FAT/CD36. Loss of the ER Ca2+ pool induced by palmitate was reverted by the phospholipase C (PLC) inhibitor edelfosine. Palmitate-dependent activation of PLC was further demonstrated by following cytosolic translocation of the pleckstrin homology domain of PLC in palmitate-treated podocytes. An inhibitor of diacylglycerol (DAG) kinase, which elevates cytosolic DAG, strongly promoted ER Ca2+ depletion by low-dose palmitate. GF109203X, a PKC inhibitor, partially prevented palmitate-induced ER Ca2+ loss. Remarkably, the mitochondrial antioxidant mitoTEMPO inhibited palmitate-induced PLC activation, ER Ca2+ depletion and cytotoxicity. Palmitate elicited cytoskeletal changes in podocytes and increased albumin permeability, which was also blocked by mitoTEMPO. These data suggest that oxidative stress caused by saturated FFA leads to

  20. Real-life assessment of the multidimensional nature of dyspnoea in COPD outpatients.

    PubMed

    Morélot-Panzini, Capucine; Gilet, Hélène; Aguilaniu, Bernard; Devillier, Philippe; Didier, Alain; Perez, Thierry; Pignier, Christophe; Arnould, Benoit; Similowski, Thomas

    2016-06-01

    Dyspnoea is a prominent symptom of chronic obstructive pulmonary disease (COPD). Recent multidimensional dyspnoea questionnaires like the Multidimensional Dyspnea Profile (MDP) individualise the sensory and affective dimensions of dyspnoea. We tested the MDP in COPD outpatients based on the hypothesis that the importance of the affective dimension of dyspnoea would vary according to clinical characteristics.A multicentre, prospective, observational, real-life study was conducted in 276 patients. MDP data were compared across various categories of patients (modified Medical Research Council (mMRC) dyspnoea score, COPD Assessment Test (CAT) score, Global Initiative for Chronic Obstructive Lung Disease (GOLD) airflow obstruction categories, GOLD "ABCD" categories, and Hospital Anxiety and Depression Scale (HADS)). Univariate and multivariate regressions were conducted to explore factors influencing the affective dimension of dyspnoea. Cluster analysis was conducted to create homogeneous patient profiles.The MDP identified a more marked affective dimension of dyspnoea with more severe mMRC, CAT, 12-item Short-Form Health Survey mental component, airflow obstruction and HADS. Multivariate analysis identified airflow obstruction, depressive symptoms and physical activity as determinants of the affective dimension of dyspnoea. Patients clustered into an "elderly, ex-smoker, severe disease, no rehabilitation" group exhibited the most marked affective dimension of dyspnoea.An affective/emotional dimension of dyspnoea can be identified in routine clinical practice. It can contribute to the phenotypic description of patients. Studies are needed to determine whether targeted therapeutic interventions can be designed and whether they are useful.

  1. Heterogeneous OH oxidation of motor oil particles causes selective depletion of branched and less cyclic hydrocarbons

    NASA Astrophysics Data System (ADS)

    Isaacman, G.; Chan, A. W.; Nah, T.; Worton, D. R.; Ruehl, C.; Kolesar, K. R.; Cappa, C. D.; Wilson, K. R.; Goldstein, A. H.

    2012-12-01

    Motor oil serves as a useful model system for atmospheric oxidation of hydrocarbon mixtures typical of anthropogenic atmospheric particulate matter, but its complexity often prevents comprehensive chemical speciation. In this work we fully characterize this formerly "unresolved complex mixture" at the molecular level using two-dimensional gas chromatography with vacuum-ultraviolet ionization and high resolution time-of-flight mass spectrometry (GCxGC/VUV-HRTOFMS). This "soft" ionization technique allows us to classify compounds by carbon number, cyclization, and branching, resolving 80-90% of hydrocarbon mass in petroleum fuels. Nucleated motor oil (15W-40) particles were oxidized by OH radicals in a flow tube reactor and the oxidative decay and transformations of straight, branched, cyclic, and polycyclic alkanes were measured using high resolution analysis. Oxidation of hydrocarbons in a complex aerosol is found to be efficient and steady, with approximately three-quarters (0.72 ± 0.06) of OH collisions yielding a reaction. Reaction rates of individual hydrocarbons are structurally dependent: compared to normal alkanes, reaction rates increased by 20-50% with branching, while rates decreased ~20% per non-aromatic ring present. These differences in rates will alter particle composition as a function of oxidation, with depletion of branched and enrichment of cyclic hydrocarbons. Compositional changes in turn influence oxidation pathways, since functionalization reactions are more prevalent with cyclic compounds. The GCxGC plane provides separation by parameters typically used in current models (volatility and polarity) so is used to explore changes in oxidation mechanisms of motor oil. Estimates of fragmentation and functionalization of this complex hydrocarbon mixture are compared to simple model compounds based on movement in the chromatographic plane.

  2. Depleted uranium oxides and silicates as spent nuclear fuel waste package fill materials

    SciTech Connect

    Forsberg, C.W.

    1996-09-10

    A new repository waste package (WP) concept for spent nuclear fuel (SNF) is being investigated that uses depleted uranium (DU) to improve performance and reduce the uncertainties of geological disposal of SNF. The WP would be filled with SNF and then filled with depleted uranium (DU) ({approximately}0.2 wt % {sup 235}U) dioxide (UO{sub 2}) or DU silicate-glass beads. Fission products and actinides can not escape the SNF UO{sub 2} crystals until the UO{sub 2} dissolves or is transformed into other chemical species. After WP failure, the DU fill material slows dissolution by three mechanisms: (1) saturation of AT groundwater with DU and suppression of SNF dissolution, (2) maintenance of chemically reducing conditions in the WP that minimize SNF solubility by sacrificial oxidation of DU from the +4 valence state, and (3) evolution of DU to lower-density hydrated uranium silicates. The fill expansion seals the WP from water flow. The DU also isotopically exchanges with SNF uranium as the SNF degrades to reduce long-term nuclear-criticality concerns.

  3. Low Nourishment of Vitamin C Induces Glutathione Depletion and Oxidative Stress in Healthy Young Adults.

    PubMed

    Waly, Mostafa I; Al-Attabi, Zahir; Guizani, Nejib

    2015-09-01

    The present study was conducted to assess the status of vitamin C among healthy young adults in relation to serum antioxidant parameters [glutathione (GSH), thiols, and total antioxidant capacity, (TAC)], and oxidative stress markers [malondialdehyde (MDA), and nitrites plus nitrates (NN)]. A prospective study included 200 young adults, and their dietary intake was assessed by using food diaries. Fasting plasma vitamin C, serum levels of GSH, thiols, TAC, MDA, and NN were measured using biochemical assays. It was observed that 38% of the enrolled subjects, n=76, had an adequate dietary intake of vitamin C (ADI group). Meanwhile, 62%, n=124, had a low dietary intake of vitamin C (LDI group) as compared to the recommended dietary allowances. The fasting plasma level of vitamin C was significantly higher in the ADI group as compared to the LDI group. Oxidative stress in the sera of the LDI group was evidenced by depletion of GSH, low thiols levels, impairment of TAC, an elevation of MDA, and increased NN. In the ADI group, positive correlations were found between plasma vitamin C and serum antioxidant parameters (GSH, thiols, and TAC). Meanwhile, the plasma vitamin C was negatively correlated with serum MDA and NN levels. This study reveals a significant increase of oxidative stress status and reduced antioxidant capacity in sera from healthy young adults with low intake of the dietary antioxidant, vitamin C.

  4. Low Nourishment of Vitamin C Induces Glutathione Depletion and Oxidative Stress in Healthy Young Adults

    PubMed Central

    Waly, Mostafa I.; Al-Attabi, Zahir; Guizani, Nejib

    2015-01-01

    The present study was conducted to assess the status of vitamin C among healthy young adults in relation to serum antioxidant parameters [glutathione (GSH), thiols, and total antioxidant capacity, (TAC)], and oxidative stress markers [malondialdehyde (MDA), and nitrites plus nitrates (NN)]. A prospective study included 200 young adults, and their dietary intake was assessed by using food diaries. Fasting plasma vitamin C, serum levels of GSH, thiols, TAC, MDA, and NN were measured using biochemical assays. It was observed that 38% of the enrolled subjects, n=76, had an adequate dietary intake of vitamin C (ADI group). Meanwhile, 62%, n=124, had a low dietary intake of vitamin C (LDI group) as compared to the recommended dietary allowances. The fasting plasma level of vitamin C was significantly higher in the ADI group as compared to the LDI group. Oxidative stress in the sera of the LDI group was evidenced by depletion of GSH, low thiols levels, impairment of TAC, an elevation of MDA, and increased NN. In the ADI group, positive correlations were found between plasma vitamin C and serum antioxidant parameters (GSH, thiols, and TAC). Meanwhile, the plasma vitamin C was negatively correlated with serum MDA and NN levels. This study reveals a significant increase of oxidative stress status and reduced antioxidant capacity in sera from healthy young adults with low intake of the dietary antioxidant, vitamin C. PMID:26451357

  5. Arsenic exposure from drinking water and dyspnoea risk in Araihazar, Bangladesh: a population-based study.

    PubMed

    Pesola, Gene R; Parvez, Faruque; Chen, Yu; Ahmed, Alauddin; Hasan, Rabiul; Ahsan, Habibul

    2012-05-01

    Bangladesh has high well water arsenic exposure. Chronic arsenic ingestion may result in diseases that manifest as dyspnoea, although information is sparse. Baseline values were obtained from an arsenic study. Trained physicians ascertained data on dyspnoea among 11,746 subjects. Data were collected on demographic factors, including smoking, blood pressure and arsenic exposure. Logistic regression models estimated odds ratios and confidence intervals for the association between arsenic exposure and dyspnoea. The adjusted odds of having dyspnoea was 1.32-fold (95% CI 1.15-1.52) greater in those exposed to high well water arsenic concentrations (≥ 50 μg · L(-1)) compared with low-arsenic-exposed nonsmokers (p<0.01). A significant dose-response relationship was found for arsenic (as well as smoking) in relation to dyspnoea. In nonsmokers, the adjusted odds of having dyspnoea were 1.36, 1.96, 2.34 and 1.80-fold greater for arsenic concentrations of 7-38, 39-90, 91-178 and 179-864 μg · L(-1), respectively, compared with the reference arsenic concentration of <7 μg · L(-1) (p<0.01; Chi-squared test for trend). Arsenic exposure through well water is associated with dyspnoea, independently of smoking status. This study suggests that mandated well water testing for arsenic with reduction in exposure may significantly reduce diseases that manifest as dyspnoea, usually cardiac or pulmonary.

  6. Arsenic exposure from drinking water and dyspnoea risk in Araihazar, Bangladesh: a population-based study

    PubMed Central

    Pesola, Gene R.; Parvez, Faruque; Chen, Yu; Ahmed, Alauddin; Hasan, Rabiul; Ahsan, Habibul

    2014-01-01

    Bangladesh has high well water arsenic exposure. Chronic arsenic ingestion may result in diseases that manifest as dyspnoea, although information is sparse. Baseline values were obtained from an arsenic study. Trained physicians ascertained data on dyspnoea among 11,746 subjects. Data were collected on demographic factors, including smoking, blood pressure and arsenic exposure. Logistic regression models estimated odds ratios and confidence intervals for the association between arsenic exposure and dyspnoea. The adjusted odds of having dyspnoea was 1.32-fold (95% CI 1.15–1.52) greater in those exposed to high well water arsenic concentrations (≥50 μg·L−1) compared with low-arsenic-exposed nonsmokers (p<0.01). A significant dose–response relationship was found for arsenic (as well as smoking) in relation to dyspnoea. In nonsmokers, the adjusted odds of having dyspnoea were 1.36, 1.96, 2.34 and 1.80-fold greater for arsenic concentrations of 7–38, 39–90, 91–178 and 179–864 μg·L−1, respectively, compared with the reference arsenic concentration of <7 μg·L−1 (p<0.01; Chi-squared test for trend). Arsenic exposure through well water is associated with dyspnoea, independently of smoking status. This study suggests that mandated well water testing for arsenic with reduction in exposure may significantly reduce diseases that manifest as dyspnoea, usually cardiac or pulmonary. PMID:22088973

  7. Exertional dyspnoea in chronic heart failure: the role of the lung and respiratory mechanical factors.

    PubMed

    Dubé, Bruno-Pierre; Agostoni, Piergiuseppe; Laveneziana, Pierantonio

    2016-09-01

    Exertional dyspnoea is among the dominant symptoms in patients with chronic heart failure and progresses relentlessly as the disease advances, leading to reduced ability to function and engage in activities of daily living. Effective management of this disabling symptom awaits a better understanding of its underlying physiology.Cardiovascular factors are believed to play a major role in dyspnoea in heart failure patients. However, despite pharmacological interventions, such as vasodilators or inotropes that improve central haemodynamics, patients with heart failure still complain of exertional dyspnoea. Clearly, dyspnoea is not determined by cardiac factors alone, but likely depends on complex, integrated cardio-pulmonary interactions.A growing body of evidence suggests that excessively increased ventilatory demand and abnormal "restrictive" constraints on tidal volume expansion with development of critical mechanical limitation of ventilation, contribute to exertional dyspnoea in heart failure. This article will offer new insights into the pathophysiological mechanisms of exertional dyspnoea in patients with chronic heart failure by exploring the potential role of the various constituents of the physiological response to exercise and particularly the role of abnormal ventilatory and respiratory mechanics responses to exercise in the perception of dyspnoea in patients with heart failure. PMID:27581831

  8. Stratospheric ozone depletion due to nitrous oxide: influences of other gases.

    PubMed

    Portmann, R W; Daniel, J S; Ravishankara, A R

    2012-05-01

    The effects of anthropogenic emissions of nitrous oxide (N(2)O), carbon dioxide (CO(2)), methane (CH(4)) and the halocarbons on stratospheric ozone (O(3)) over the twentieth and twenty-first centuries are isolated using a chemical model of the stratosphere. The future evolution of ozone will depend on each of these gases, with N(2)O and CO(2) probably playing the dominant roles as halocarbons return towards pre-industrial levels. There are nonlinear interactions between these gases that preclude unambiguously separating their effect on ozone. For example, the CH(4) increase during the twentieth century reduced the ozone losses owing to halocarbon increases, and the N(2)O chemical destruction of O(3) is buffered by CO(2) thermal effects in the middle stratosphere (by approx. 20% for the IPCC A1B/WMO A1 scenario over the time period 1900-2100). Nonetheless, N(2)O is expected to continue to be the largest anthropogenic emission of an O(3)-destroying compound in the foreseeable future. Reductions in anthropogenic N(2)O emissions provide a larger opportunity for reduction in future O(3) depletion than any of the remaining uncontrolled halocarbon emissions. It is also shown that 1980 levels of O(3) were affected by halocarbons, N(2)O, CO(2) and CH(4), and thus may not be a good choice of a benchmark of O(3) recovery.

  9. Stratospheric ozone depletion due to nitrous oxide: influences of other gases

    PubMed Central

    Portmann, R. W.; Daniel, J. S.; Ravishankara, A. R.

    2012-01-01

    The effects of anthropogenic emissions of nitrous oxide (N2O), carbon dioxide (CO2), methane (CH4) and the halocarbons on stratospheric ozone (O3) over the twentieth and twenty-first centuries are isolated using a chemical model of the stratosphere. The future evolution of ozone will depend on each of these gases, with N2O and CO2 probably playing the dominant roles as halocarbons return towards pre-industrial levels. There are nonlinear interactions between these gases that preclude unambiguously separating their effect on ozone. For example, the CH4 increase during the twentieth century reduced the ozone losses owing to halocarbon increases, and the N2O chemical destruction of O3 is buffered by CO2 thermal effects in the middle stratosphere (by approx. 20% for the IPCC A1B/WMO A1 scenario over the time period 1900–2100). Nonetheless, N2O is expected to continue to be the largest anthropogenic emission of an O3-destroying compound in the foreseeable future. Reductions in anthropogenic N2O emissions provide a larger opportunity for reduction in future O3 depletion than any of the remaining uncontrolled halocarbon emissions. It is also shown that 1980 levels of O3 were affected by halocarbons, N2O, CO2 and CH4, and thus may not be a good choice of a benchmark of O3 recovery. PMID:22451111

  10. Altered chondrocytic oxidative metabolism during the restoration of depleted intercellular matrix.

    PubMed Central

    Boussidan, F.; Nahir, A. M.

    1990-01-01

    The depletion of proteoglycans (PGs), induced by a single intravenous injection of papain, is a useful model for studying the response of chondrocytes in vivo to injury. The present study concentrated on the activity of enzymes related to the synthesis of PGs, either directly, with uridine diphosphoglucose dehydrogenase (UDPGD), or indirectly, through the general oxidative metabolism of the chondrocytes. Most of the enzymes showed diminished activity on day 2; in some, there was little change in activity, whereas in others there was marked increase in activity over the following days. Thus, on day 9 the activities of glucose-6-phosphate dehydrogenase and of glyceraldehyde-3-phosphate dehydrogenase were twice the original (day 0) values, and those of succinate dehydrogenase and of UDPGD were one and a half times greater than the original activities. Such increased enzymatic activity preceded the increase in PG content, which by day 14 reached up to 80% of the initial value. Both the increased activity and the replenishment of the PG content were inhibited when hydrocortisone (10 mg/kg) was injected. Images Fig. 1 PMID:2372415

  11. Severe dyspnoea with alteration of the diffusion capacity of the lung associated with fingolimod treatment.

    PubMed

    Bianco, Assunta; Patanella, Agata Katia; Nociti, Viviana; De Fino, Chiara; Lucchini, Matteo; Savio, Francesco Lo; Rossini, Paolo Maria; Mirabella, Massimiliano

    2016-09-01

    In phase II clinical trial, fingolimod at a dose of 5.0mg (ten times higher than the currently approved dose) induced dyspnoea and decreased forced expiratory flow in some patients, probably trought an airways constriction S1P4-mediated. In phase III trials, respiratory adverse events associated with fingolimod treatment as dyspnoea, cough, oropharingeal pain and nasal congestion are reported with the same incidence of placebo. Here we report two cases of severe dyspnoea with alteration of the diffusion capacity of the lung associated with fingolimod treatment, which led to permanent treatment withdrawal. PMID:27645336

  12. Exertional dyspnoea in COPD: the clinical utility of cardiopulmonary exercise testing.

    PubMed

    O'Donnell, Denis E; Elbehairy, Amany F; Faisal, Azmy; Webb, Katherine A; Neder, J Alberto; Mahler, Donald A

    2016-09-01

    Activity-related dyspnoea is often the most distressing symptom experienced by patients with chronic obstructive pulmonary disease (COPD) and can persist despite comprehensive medical management. It is now clear that dyspnoea during physical activity occurs across the spectrum of disease severity, even in those with mild airway obstruction. Our understanding of the nature and source of dyspnoea is incomplete, but current aetiological concepts emphasise the importance of increased central neural drive to breathe in the setting of a reduced ability of the respiratory system to appropriately respond. Since dyspnoea is provoked or aggravated by physical activity, its concurrent measurement during standardised laboratory exercise testing is clearly important. Combining measurement of perceptual and physiological responses during exercise can provide valuable insights into symptom severity and its pathophysiological underpinnings. This review summarises the abnormal physiological responses to exercise in COPD, as these form the basis for modern constructs of the neurobiology of exertional dyspnoea. The main objectives are: 1) to examine the role of cardiopulmonary exercise testing (CPET) in uncovering the physiological mechanisms of exertional dyspnoea in patients with mild-to-moderate COPD; 2) to examine the escalating negative sensory consequences of progressive respiratory impairment with disease advancement; and 3) to build a physiological rationale for individualised treatment optimisation based on CPET. PMID:27581832

  13. Clinical Scores for Dyspnoea Severity in Children: A Prospective Validation Study

    PubMed Central

    Eggink, Hendriekje; Brand, Paul; Reimink, Roelien; Bekhof, Jolita

    2016-01-01

    Background In acute dyspnoeic children, assessment of dyspnoea severity and treatment response is frequently based on clinical dyspnoea scores. Our study aim was to validate five commonly used paediatric dyspnoea scores. Methods Fifty children aged 0–8 years with acute dyspnoea were clinically assessed before and after bronchodilator treatment, a subset of 27 children were videotaped and assessed twice by nine observers. The observers scored clinical signs necessary to calculate the Asthma Score (AS), Asthma Severity Score (ASS), Clinical Asthma Evaluation Score 2 (CAES-2), Pediatric Respiratory Assessment Measure (PRAM) and respiratory rate, accessory muscle use, decreased breath sounds (RAD). Results A total of 1120 observations were used to assess fourteen measurement properties within domains of validity, reliability and utility. All five dyspnoea scores showed overall poor results, scoring insufficiently on more than half of the quality criteria for measurement properties. The AS and PRAM were the most valid with good values on six and moderate values on three properties. Poor results were mainly due to insufficient measurement properties in the validity and reliability domains whereas utility properties were moderate to good in all scores. Conclusion This study shows that commonly used dyspnoea scores show insufficient validity and reliability to allow for clinical use without caution. PMID:27382963

  14. Common causes of dyspnoea in athletes: a practical approach for diagnosis and management

    PubMed Central

    Mohseni, Zahra S.; Berwager, Jeffrey D.; Hegedus, Eric J.

    2016-01-01

    Key points “Dyspnoea” during exercise is a common complaint in seemingly otherwise healthy athletes, which may be associated with fatigue and underperformance. Because dyspnoea is an general term and may be caused by numerous factors, ranging from poor aerobic fitness to serious, potentially fatal respiratory and nonrespiratory pathologies, it is important for clinicians to obtain an appropriate case history and ask relevant exercise-specific questions to fully characterise the nature of the complaint so that a targeted diagnostic plan can be developed. Exercise-induced bronchoconstriction and exercise-induced laryngeal obstruction are two common causes of dyspnoea in athletes, and both are regularly misdiagnosed and mismanaged due to poor adherence to available practice parameters. Aside from airway dysfunction, iron deficiency and anaemia, infectious disease, and musculoskeletal conditions are common problems in athletes which ultimately may lead to complaints of dyspnoea. Educational aims To inform readers of the common causes of dyspnoea encountered in athletes. To highlight that airway diseases, such as asthma and exercise-induced bronchoconstriction, are commonly misdiagnosed and mismanaged. To introduce readers to common nonairway causes of dyspnoea in athletes, including clinical features and general principles of diagnosis, and management. To emphasise the importance of a detailed case history and proper adherence to established protocols in evaluating and managing the dyspnoeic athlete. To provide readers with a general framework of appropriate questions that are useful for developing a targeted diagnostic plan for evaluating dyspnoeic athletes. Dyspnoea during exercise is a common chief complaint in athletes and active individuals. It is not uncommon for dyspnoeic athletes to be diagnosed with asthma, “exercise-induced asthma” or exercise-induced bronchoconstriction based on their symptoms, but this strategy regularly leads to misdiagnosis and

  15. Acute depletion of plasma glutamine increases leucine oxidation in prednisone-treated humans.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To determine whether depletion in plasma glutamine worsens the catabolic response to corticosteroids, seven healthy volunteers received oral prednisone for 6 days on two separate occasions, at least 2 weeks apart, and in random order. On the sixth day of each treatment course, they received 5 h intr...

  16. Efficiency of photosynthetic water oxidation at ambient and depleted levels of inorganic carbon.

    PubMed

    Shevela, Dmitriy; Nöring, Birgit; Koroidov, Sergey; Shutova, Tatiana; Samuelsson, Göran; Messinger, Johannes

    2013-11-01

    Over 40 years ago, Joliot et al. (Photochem Photobiol 10:309-329, 1969) designed and employed an elegant and highly sensitive electrochemical technique capable of measuring O2 evolved by photosystem II (PSII) in response to trains of single turn-over light flashes. The measurement and analysis of flash-induced oxygen evolution patterns (FIOPs) has since proven to be a powerful method for probing the turnover efficiency of PSII. Stemler et al. (Proc Natl Acad Sci USA 71(12):4679-4683, 1974), in Govindjee's lab, were the first to study the effect of "bicarbonate" on FIOPs by adding the competitive inhibitor acetate. Here, we extend this earlier work by performing FIOPs experiments at various, strictly controlled inorganic carbon (Ci) levels without addition of any inhibitors. For this, we placed a Joliot-type bare platinum electrode inside a N2-filled glove-box (containing 10-20 ppm CO2) and reduced the Ci concentration simply by washing the samples in Ci-depleted media. FIOPs of spinach thylakoids were recorded either at 20-times reduced levels of Ci or at ambient Ci conditions (390 ppm CO2). Numerical analysis of the FIOPs within an extended Kok model reveals that under Ci-depleted conditions the miss probability is discernibly larger (by 2-3 %) than at ambient conditions, and that the addition of 5 mM HCO3 (-) to the Ci-depleted thylakoids largely restores the original miss parameter. Since a "mild" Ci-depletion procedure was employed, we discuss our data with respect to a possible function of free or weakly bound HCO3 (-) at the water-splitting side of PSII. PMID:23828399

  17. PX-12-induced HeLa cell death is associated with oxidative stress and GSH depletion.

    PubMed

    Shin, Hye Rim; You, Bo Ra; Park, Woo Hyun

    2013-12-01

    PX-12, as an inhibitor of thioredoxin (Trx), has antitumor activity. However, little is known about the toxicological effect of PX-12 on cervical cancer cells. In the present study, the growth inhibitory effects of PX-12 on HeLa cervical cancer cells in association with reactive oxygen species (ROS) and glutathione (GSH) levels were investigated. Based on MTT assays, PX-12 inhibited the growth of HeLa cells with an IC50 value of ~7 μM at 72 h. DNA flow cytometry analysis indicated that 5 and 10 μM PX-12 significantly induced a G2/M phase arrest of the cell cycle. PX-12 also increased the number of dead cells and annexin V-fluorescein isothiocyanate-positive cells, which was accompanied by the loss of mitochondrial membrane potential. All the investigated caspase inhibitors significantly rescued certain cells from PX-12-induced HeLa cell death. With respect to ROS and GSH levels, PX-12 increased ROS levels (including O2(•-)) in HeLa cells and induced GSH depletion. N-acetyl cysteine markedly reduced the levels of O2(•-) in PX-12-treated HeLa cells, and prevented apoptotic cell death and GSH depletion in these cells. By contrast, L-buthionine sulfoximine intensified cell death and GSH depletion in PX-12-treated HeLa cells. To conclude, this is the first study to demonstrate that PX-12 inhibits the growth of HeLa cells via G2/M phase arrest, as well as inhibiting apoptosis; the effect was associated with intracellular increases in ROS levels and GSH depletion.

  18. Tidal expiratory flow limitation, dyspnoea and exercise capacity in patients with bilateral bronchiectasis.

    PubMed

    Koulouris, N G; Retsou, S; Kosmas, E; Dimakou, K; Malagari, K; Mantzikopoulos, G; Koutsoukou, A; Milic-Emili, J; Jordanoglou, J

    2003-05-01

    In this study the authors investigated whether expiratory flow limitation (FL) is present during tidal breathing in patients with bilateral bronchiectasis (BB) and whether it is related to the severity of chronic dyspnoea (Medical Research Council (MRC) dyspnoea scale), exercise capacity (maximal mechanical power output (WRmax)) and severity of the disease, as assessed by high-resolution computed tomography (HRCT) scoring. Lung function, MRC dyspnoea, HRCT score, WRmax and FL were assessed in 23 stable caucasian patients (six males) aged 56 +/- 17 yrs. FL was assessed at rest both in seated and supine positions. To detect FL, the negative expiratory pressure (NEP) technique was used. The degree of FL was rated using a five-point FL score. WRmax was measured using a cyclo-ergometer. According to the NEP technique, five patients were FL during resting breathing when supine but not seated, four were FL both seated and supine, and 14 were NFL both seated and supine. Furthermore, it was shown that: 1) in stable BB patients FL during resting breathing is common, especially in the supine position; 2) the degree of MRC dyspnoea is closely related to the five-point FL score; 3) WRmax (% pred) is more closely correlated with the MRC dyspnoea score than with the five-point FL score; and 4) HRCT score is closely related to forced expiratory volume in one second % pred but not five-point FL score. In conclusion, flow limitation is common at rest in sitting and supine positions in patients with bilateral bronchiectasis. Flow limitation and reduced exercise capacity are both associated with more severe dyspnoea. Finally, high-resolution computed tomography scoring correlates best with forced expiratory volume in one second.

  19. Influence of oxygen depletion layer on the properties of tin oxide gas-sensing films fabricated by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Natarajan, Gomathi; Cameron, David C.

    2009-06-01

    In this paper we report on the influence of film thickness on the electrical and gas-sensing properties of tin oxide thin films grown by atomic layer deposition (ALD) technique. The nature of the carrier and post-flow gases used in ALD was found to have a dramatic influence on the electrical conductance of the deposited films. Up to a film thickness of 50 nm the sheet conductance of the films increased with the thickness, and above 50 nm the sheet conductance was not significantly influenced by the film thickness. This effect was attributed to oxygen depletion at the film surface. When the depth of oxygen depletion ( d dep) was greater than or equal to the film thickness ( t), the sheet conductance was thickness dependant. On the other hand, when d dep≤ t, the sheet conductance was independent of the film thickness but depended on the depth of the oxygen depletion. This proposed explanation was verified by subjecting the films to different lengths of post-annealing in an oxygen depleted atmosphere. Gas-sensing functionality of the films with various thicknesses was examined. It was observed that the film thickness had a significant influence on the gas-sensing property of the films. When the thickness was greater than 40 nm, the sensitivity of the films to ethanol was found to follow the widely reported trend, i.e., the sensitivity decreases when the film thickness increases. Below the film thickness of 40 nm the sensitivity decreases as film thickness decreases, and we propose a model to explain this observation based on the increase in resistance due to multiple grain boundaries.

  20. Cysteine depletion causes oxidative stress and triggers outer membrane vesicle release by Neisseria meningitidis; implications for vaccine development.

    PubMed

    van de Waterbeemd, Bas; Zomer, Gijsbert; van den Ijssel, Jan; van Keulen, Lonneke; Eppink, Michel H; van der Ley, Peter; van der Pol, Leo A

    2013-01-01

    Outer membrane vesicles (OMV) contain immunogenic proteins and contribute to in vivo survival and virulence of bacterial pathogens. The first OMV vaccines successfully stopped Neisseria meningitidis serogroup B outbreaks but required detergent-extraction for endotoxin removal. Current vaccines use attenuated endotoxin, to preserve immunological properties and allow a detergent-free process. The preferred process is based on spontaneously released OMV (sOMV), which are most similar to in vivo vesicles and easier to purify. The release mechanism however is poorly understood resulting in low yield. This study with N. meningitidis demonstrates that an external stimulus, cysteine depletion, can trigger growth arrest and sOMV release in sufficient quantities for vaccine production (±1500 human doses per liter cultivation). Transcriptome analysis suggests that cysteine depletion impairs iron-sulfur protein assembly and causes oxidative stress. Involvement of oxidative stress is confirmed by showing that addition of reactive oxygen species during cysteine-rich growth also triggers vesiculation. The sOMV in this study are similar to vesicles from natural infection, therefore cysteine-dependent vesiculation is likely to be relevant for the in vivo pathogenesis of N. meningitidis. PMID:23372704

  1. Grain boundary depletion and migration during selective oxidation of Cr in a Ni-5Cr binary alloy exposed to high-temperature hydrogenated water

    SciTech Connect

    Schreiber, Daniel K.; Olszta, Matthew J.; Bruemmer, Stephen M.

    2014-10-01

    High-resolution microscopy of a high-purity Ni-5Cr alloy exposed to 360°C hydrogenated water reveals intergranular selective oxidation of Cr accompanied by local Cr depletion and diffusion-induced grain boundary migration (DIGM). The corrosion-product oxide consists of a porous, interconnected network of Cr2O3 platelets with no further O ingress into the metal ahead. Extensive grain boundary depletion of Cr (to <0.05at.%) is observed typically 20–100 nm wide as a result of DIGM and reaching depths of many micrometers beyond the oxidation front.

  2. Dyspnoea at rest and at the end of different exercises in patients with near-fatal asthma.

    PubMed

    Barreiro, E; Gea, J; Sanjuás, C; Marcos, R; Broquetas, J; Milic-Emili, J

    2004-08-01

    Blunted perception of dyspnoea under resistive loading has been observed in patients with a history of near-fatal asthma (NFA). The perception of dyspnoea at rest and at the end point of various exercises was assessed in such patients. Respiratory function and exercise capacity (6-min walking distance, incremental cycloergometry and inspiratory threshold loading) were assessed in seven NFA and eight non-NFA patients. Dyspnoea (Borg scale) was measured at rest and at the end point of the various exercises. Dyspnoea at rest was significantly lower in NFA patients. Although exercise tolerance was similarly reduced in both the NFA and non-NFA groups, dyspnoea at peak cycle exercise was significantly lower in the former (2.6+/-2 versus 6.1+/-3.8 (Borg scale; mean+/-SD)), who mainly (86%) stopped because of leg discomfort. A similar trend was observed in the 6-min walking distance and inspiratory threshold loading tests. Dyspnoea at peak exercise was the best indicator of the NFA condition, with a sensitivity of 100% and specificity of 63% for a Borg scale score of < or = 6. Perception of dyspnoea is blunted in near-fatal asthma patients at both rest and the end point of various forms of exercise. Dyspnoea at peak exercise is the best indicator of the near-fatal asthma condition. PMID:15332388

  3. A young man with dyspnoea and audible expiration: the loops never lie.

    PubMed

    Taher, Hisham; Samuelson, Megan; Gehlbach, Brian; Gross, Thomas

    2016-06-01

    Spirometry provides clues to solving this puzzle of dyspnoea and wheeze in a young nonsmoker-the loops never lie! http://ow.ly/YC9zI A 10 s recording of expiratory sounds from this case can be found at: http://ow.ly/UVVu300moD1.

  4. Cognitive behaviour therapy reduces dyspnoea ratings in patients with chronic obstructive pulmonary disease (COPD).

    PubMed

    Livermore, Nicole; Dimitri, Andrew; Sharpe, Louise; McKenzie, David K; Gandevia, Simon C; Butler, Jane E

    2015-09-15

    There is evidence that psychological factors contribute to the perception of increased difficulty of breathing in patients with chronic obstructive pulmonary disease (COPD), and increase morbidity. We tested the hypothesis that cognitive behaviour therapy (CBT) decreases ratings of perceived dyspnoea in response to resistive loading in patients with COPD. From 31 patients with COPD, 18 were randomised to four sessions of specifically targeted CBT and 13 to routine care. Prior to randomisation, participants were tested with an inspiratory external resistive load protocol (loads between 5 and 45cmH2O/L/s). Six months later, we re-measured perceived dyspnoea in response to the same inspiratory resistive loads and compared results to measurements prior to randomisation. There was a significant 17% reduction in dyspnoea ratings across the loads for the CBT group, and no reduction for the routine care group. The decrease in ratings of dyspnoea suggests that CBT to alleviate breathing discomfort may have a role in the routine treatment of people with COPD.

  5. A young man with dyspnoea and audible expiration: the loops never lie.

    PubMed

    Taher, Hisham; Samuelson, Megan; Gehlbach, Brian; Gross, Thomas

    2016-06-01

    Spirometry provides clues to solving this puzzle of dyspnoea and wheeze in a young nonsmoker-the loops never lie! http://ow.ly/YC9zI A 10 s recording of expiratory sounds from this case can be found at: http://ow.ly/UVVu300moD1. PMID:27408634

  6. Dual bronchodilation with QVA149 reduces patient-reported dyspnoea in COPD: the BLAZE study.

    PubMed

    Mahler, Donald A; Decramer, Marc; D'Urzo, Anthony; Worth, Heinrich; White, Tracy; Alagappan, Vijay K T; Chen, Hungta; Gallagher, Nicola; Kulich, Károly; Banerji, Donald

    2014-06-01

    We evaluated the effect of QVA149, a dual bronchodilator combining indacaterol and glycopyrronium, on direct patient-reported dyspnoea in patients with moderate-to-severe chronic obstructive pulmonary disease. In this multicentre, blinded, double-dummy, three-period crossover study, 247 patients were randomised to once-daily QVA149 110/50 μg, placebo or tiotropium 18 μg. Superiority of QVA149 versus placebo (primary objective) and tiotropium (secondary objective) was assessed for improvement in dyspnoea via the self-administered computerised (SAC) version of the Baseline and Transition Dyspnoea Index after 6 weeks. Secondary end-points included lung function, rescue medication use and safety. After 6 weeks, the SAC Transition Dyspnoea Index total score was significantly higher with QVA149 versus placebo (least squares mean (LSM) treatment difference 1.37, p<0.001) and tiotropium (LSM treatment difference 0.49, p=0.021). QVA149 provided significant improvements in lung function, with higher forced expiratory volume in 1 s area under the curve from 0-4 h post-dose versus placebo and tiotropium at day 1 and week 6 (all p<0.001). Rescue medication use was significantly lower with QVA149 versus placebo (p<0.001) and tiotropium (p=0.002). All treatments were well tolerated. Once-daily QVA149 provided superior improvements in patient-reported dyspnoea and lung function versus placebo and tiotropium. These benefits were associated with improvements in other symptoms and reduced use of rescue medication.

  7. Assessment at the single-cell level identifies neuronal glutathione depletion as both a cause and effect of ischemia-reperfusion oxidative stress.

    PubMed

    Won, Seok Joon; Kim, Ji-Eun; Cittolin-Santos, Giordano Fabricio; Swanson, Raymond A

    2015-05-01

    Oxidative stress contributes to neuronal death in brain ischemia-reperfusion. Tissue levels of the endogenous antioxidant glutathione (GSH) are depleted during ischemia-reperfusion, but it is unknown whether this depletion is a cause or an effect of oxidative stress, and whether it occurs in neurons or other cell types. We used immunohistochemical methods to evaluate glutathione, superoxide, and oxidative stress in mouse hippocampal neurons after transient forebrain ischemia. GSH levels in CA1 pyramidal neurons were normally high relative to surrounding neuropil, and exhibited a time-dependent decrease during the first few hours of reperfusion. Colabeling for superoxide in the neurons showed a concurrent increase in detectable superoxide over this interval. To identify cause-effect relationships between these changes, we independently manipulated superoxide production and GSH metabolism during reperfusion. Mice in which NADPH oxidase activity was blocked to prevent superoxide production showed preservation of neuronal GSH content, thus demonstrating that neuronal GSH depletion is result of oxidative stress. Conversely, mice in which neuronal GSH levels were maintained by N-acetyl cysteine treatment during reperfusion showed less neuronal superoxide signal, oxidative stress, and neuronal death. At 3 d following ischemia, GSH content in reactive astrocytes and microglia was increased in the hippocampal CA1 relative to surviving neurons. Results of these studies demonstrate that neuronal GSH depletion is both a result and a cause of neuronal oxidative stress after ischemia-reperfusion, and that postischemic restoration of neuronal GSH levels can be neuroprotective.

  8. EBSD characterisation of Y2Ba4CuUOx phase in melttextured YBCO with addition of depleted uranium oxide

    NASA Astrophysics Data System (ADS)

    Koblischka-Veneva, A.; Mücklich, F.; Koblischka, M. R.; Babu, N. Hari; Cardwell, D. A.

    2006-06-01

    Melt-textured YBCO samples processed with added Y2O3 and depleted uranium oxide (DU) contain nano-particles, which have been identified previously as Y2Ba4CuUOx (U-411). This phase has a cubic unit cell, which is clearly distinct from the orthorhombic Y-123 and Y-211 phases within the YBCO system. In samples with a high amount of DU addition (0.8 wt-% DU), U-2411 particles have sizes between 200 nm and several µm, so identification of the Kikuchi patterns of this phase becomes possible. Together with a parallel EDX analysis, the particles embedded in the Y-123 matrix can be identified unambiguously. In this way, a three-phase EBSD scan becomes possible, allowing also the identification of nanometre-sized particles in the sample microstructure.

  9. Depletion analysis of mixed-oxide fuel pins in light water reactors and the Advanced Test Reactor

    SciTech Connect

    Chang, G.S.; Ryskamp, J.M.

    2000-03-01

    An experiment containing weapons-grade mixed-oxide (WG-MOX) fuel has been designed and is being irradiated in the Advanced Test Reactor (ATR) at the Idaho National Engineering and Environmental Laboratory (INEEL). The ability to accurately predict fuel pin performance is an essential requirement for the MOX fuel test assembly design. Detailed radial fission power and temperature profile effects and fission gas release in the fuel pin are a function of the fuel pin's temperature, fission power, and fission product ad actinide concentration profiles. In addition, the burnup-dependent profile analyses in irradiated fuel pins is important for fuel performance analysis to support the potential licensing of the MOX fuel made from WG-plutonium and depleted uranium for use in US reactors. The MCNP Coupling With ORIGEN2 burnup calculation code (MCWO) can analyze the detailed burnup profiles of WG-MOX and reactor-grade mixed-oxide (RG-MOX) fuel pins. The validated code MCWO can provide the best-estimate neutronic characteristics of fuel burnup performance analysis. Applying this capability with a new minicell method allows calculation of detailed nuclide concentration and power distributions within the MOX pins as a function of burnup. This methodology was applied to MOX fuel in a commercial pressurized water reactor and in an experiment currently being irradiated in the ATR. The prediction of nuclide concentration profiles and power distributions in irradiated MOX plus via this new methodology can provide insights into MOX fuel performance.

  10. Oceanic nickel depletion and a methanogen famine before the Great Oxidation Event.

    PubMed

    Konhauser, Kurt O; Pecoits, Ernesto; Lalonde, Stefan V; Papineau, Dominic; Nisbet, Euan G; Barley, Mark E; Arndt, Nicholas T; Zahnle, Kevin; Kamber, Balz S

    2009-04-01

    It has been suggested that a decrease in atmospheric methane levels triggered the progressive rise of atmospheric oxygen, the so-called Great Oxidation Event, about 2.4 Gyr ago. Oxidative weathering of terrestrial sulphides, increased oceanic sulphate, and the ecological success of sulphate-reducing microorganisms over methanogens has been proposed as a possible cause for the methane collapse, but this explanation is difficult to reconcile with the rock record. Banded iron formations preserve a history of Precambrian oceanic elemental abundance and can provide insights into our understanding of early microbial life and its influence on the evolution of the Earth system. Here we report a decline in the molar nickel to iron ratio recorded in banded iron formations about 2.7 Gyr ago, which we attribute to a reduced flux of nickel to the oceans, a consequence of cooling upper-mantle temperatures and decreased eruption of nickel-rich ultramafic rocks at the time. We measured nickel partition coefficients between simulated Precambrian sea water and diverse iron hydroxides, and subsequently determined that dissolved nickel concentrations may have reached approximately 400 nM throughout much of the Archaean eon, but dropped below approximately 200 nM by 2.5 Gyr ago and to modern day values ( approximately 9 nM) by approximately 550 Myr ago. Nickel is a key metal cofactor in several enzymes of methanogens and we propose that its decline would have stifled their activity in the ancient oceans and disrupted the supply of biogenic methane. A decline in biogenic methane production therefore could have occurred before increasing environmental oxygenation and not necessarily be related to it. The enzymatic reliance of methanogens on a diminishing supply of volcanic nickel links mantle evolution to the redox state of the atmosphere.

  11. Oceanic nickel depletion and a methanogen famine before the Great Oxidation Event.

    PubMed

    Konhauser, Kurt O; Pecoits, Ernesto; Lalonde, Stefan V; Papineau, Dominic; Nisbet, Euan G; Barley, Mark E; Arndt, Nicholas T; Zahnle, Kevin; Kamber, Balz S

    2009-04-01

    It has been suggested that a decrease in atmospheric methane levels triggered the progressive rise of atmospheric oxygen, the so-called Great Oxidation Event, about 2.4 Gyr ago. Oxidative weathering of terrestrial sulphides, increased oceanic sulphate, and the ecological success of sulphate-reducing microorganisms over methanogens has been proposed as a possible cause for the methane collapse, but this explanation is difficult to reconcile with the rock record. Banded iron formations preserve a history of Precambrian oceanic elemental abundance and can provide insights into our understanding of early microbial life and its influence on the evolution of the Earth system. Here we report a decline in the molar nickel to iron ratio recorded in banded iron formations about 2.7 Gyr ago, which we attribute to a reduced flux of nickel to the oceans, a consequence of cooling upper-mantle temperatures and decreased eruption of nickel-rich ultramafic rocks at the time. We measured nickel partition coefficients between simulated Precambrian sea water and diverse iron hydroxides, and subsequently determined that dissolved nickel concentrations may have reached approximately 400 nM throughout much of the Archaean eon, but dropped below approximately 200 nM by 2.5 Gyr ago and to modern day values ( approximately 9 nM) by approximately 550 Myr ago. Nickel is a key metal cofactor in several enzymes of methanogens and we propose that its decline would have stifled their activity in the ancient oceans and disrupted the supply of biogenic methane. A decline in biogenic methane production therefore could have occurred before increasing environmental oxygenation and not necessarily be related to it. The enzymatic reliance of methanogens on a diminishing supply of volcanic nickel links mantle evolution to the redox state of the atmosphere. PMID:19360085

  12. Onset of recent exertional dyspnoea in a firefighter with left bundle-branch block

    PubMed Central

    De Rosa, Roberto; Ratti, Gennaro; Lamberti, Monica

    2014-01-01

    Background The presence of a left bundle-branch block (LBBB) among firefighters raises questions about stratifying risk of subsequent cardiovascular events as this conduction disorder may mask underlying coronary artery disease. This report describes the case of a firefighter with a history LBBB with exertional dyspnoea of recent onset after work activity. Case report A 39-year-old male firefighter with LBBB developed exertional dyspnoea after a prolonged session of work. ECG and treadmill test only showed a permanent LBBB; echocardiography and myocardial scintigraphy did not add to this. However, multislice CT (MSCT) showed a significant stenosis in the mid-left anterior descending artery (LAD). Coronary angiography confirmed the stenosis with subsequent placement of a coronary stent. Conclusions An occupational physician should take into account that factors such as age and low cardiovascular risk do not always exclude heart disease, especially when there are conduction system abnormalities that can mask possible coronary artery disease. PMID:25352387

  13. Cough and dyspnoea may discriminate allergic and infectious respiratory phenotypes in infancy.

    PubMed

    Rancière, Fanny; Clarisse, Bénédicte; Nikasinovic, Lydia; Just, Jocelyne; Momas, Isabelle

    2012-06-01

    Asthma symptoms are non-specific during infancy, making the identification of different subgroups among preschool children with early respiratory manifestations an important challenge. We previously used a clustering approach to identify bronchial obstructive phenotypes in 1-yr-old infants from the Pollution and Asthma Risk: an Infant Study (PARIS) birth cohort. In the present study, we examined whether these phenotypes were stable at 3 yr and studied their comorbidity and risk factors. Partitioning around medoids (PAM) method was applied at 1 and 3 yr of age to cluster children according to wheezing, dry night cough, dyspnoea with sleep disturbance and breathlessness. The resulting groups were used to derive phenotypes in 2084 children during their first 3 yr of life. Analysis of associated comorbidity and risk factors was conducted using multinomial logistic regression. PAM groups were similarly defined at both ages so that two respiratory phenotypes were identified between birth and 3 yr: cough phenotype (CP) and dyspnoea phenotype (DP) including 14.1% and 30.7% of children, respectively. CP infants experienced more often allergic features than DP, dominated by respiratory infections. Parental history of allergy, potential allergen exposure and psychosocial factors were associated with CP. Day care centre attendance was more frequent in DP as well as exposure to domestic chemical pollution, suggesting a greater vulnerability to pathogens. Finally, dry night cough and dyspnoea disturbing the sleep appear to be markers of two respiratory profiles potentially allergic and infectious before 3 yr old.

  14. Cough and dyspnoea may discriminate allergic and infectious respiratory phenotypes in infancy.

    PubMed

    Rancière, Fanny; Clarisse, Bénédicte; Nikasinovic, Lydia; Just, Jocelyne; Momas, Isabelle

    2012-06-01

    Asthma symptoms are non-specific during infancy, making the identification of different subgroups among preschool children with early respiratory manifestations an important challenge. We previously used a clustering approach to identify bronchial obstructive phenotypes in 1-yr-old infants from the Pollution and Asthma Risk: an Infant Study (PARIS) birth cohort. In the present study, we examined whether these phenotypes were stable at 3 yr and studied their comorbidity and risk factors. Partitioning around medoids (PAM) method was applied at 1 and 3 yr of age to cluster children according to wheezing, dry night cough, dyspnoea with sleep disturbance and breathlessness. The resulting groups were used to derive phenotypes in 2084 children during their first 3 yr of life. Analysis of associated comorbidity and risk factors was conducted using multinomial logistic regression. PAM groups were similarly defined at both ages so that two respiratory phenotypes were identified between birth and 3 yr: cough phenotype (CP) and dyspnoea phenotype (DP) including 14.1% and 30.7% of children, respectively. CP infants experienced more often allergic features than DP, dominated by respiratory infections. Parental history of allergy, potential allergen exposure and psychosocial factors were associated with CP. Day care centre attendance was more frequent in DP as well as exposure to domestic chemical pollution, suggesting a greater vulnerability to pathogens. Finally, dry night cough and dyspnoea disturbing the sleep appear to be markers of two respiratory profiles potentially allergic and infectious before 3 yr old. PMID:22300433

  15. Low frequency noise and radiation response in the partially depleted SOI MOSFETs with ion implanted buried oxide

    NASA Astrophysics Data System (ADS)

    Liu, Yuan; Chen, Hai-Bo; Liu, Yu-Rong; Wang, Xin; En, Yun-Fei; Li, Bin; Lu, Yu-Dong

    2015-08-01

    Low frequency noise behaviors of partially depleted silicon-on-insulator (PDSOI) n-channel metal-oxide semiconductors (MOS) transistors with and without ion implantation into the buried oxide are investigated in this paper. Owing to ion implantation-induced electron traps in the buried oxide and back interface states, back gate threshold voltage increases from 44.48 V to 51.47 V and sub-threshold swing increases from 2.47 V/dec to 3.37 V/dec, while electron field effect mobility decreases from 475.44 cm2/V·s to 363.65 cm2/V·s. In addition, the magnitude of normalized low frequency noise also greatly increases, which indicates that the intrinsic electronic performances are degenerated after ion implantation processing. According to carrier number fluctuation theory, the extracted flat-band voltage noise power spectral densities in the PDSOI devices with and without ion implantation are equal to 7×10-10 V2·Hz-1 and 2.7×10-8 V2·Hz-1, respectively, while the extracted average trap density in the buried oxide increases from 1.42×1017 cm-3·eV-1 to 6.16×1018 cm-3·eV-1. Based on carrier mobility fluctuation theory, the extracted average Hooge’s parameter in these devices increases from 3.92×10-5 to 1.34×10-2 after ion implantation processing. Finally, radiation responses in the PDSOI devices are investigated. Owing to radiation-induced positive buried oxide trapped charges, back gate threshold voltage decreases with the increase of the total dose. After radiation reaches up to a total dose of 1 M·rad(si), the shifts of back gate threshold voltage in the SOI devices with and without ion implantation are -10.82 V and -31.84 V, respectively. The low frequency noise behaviors in these devices before and after radiation are also compared and discussed. Project supported by the National Natural Science Foundation of China (Grant Nos. 61204112 and 61204116).

  16. Glutathione depletion exacerbates impairment by oxidative stress of phosphoinositide hydrolysis, AP-1, and NF-kappaB activation by cholinergic stimulation.

    PubMed

    Li, X; Song, L; Jope, R S

    1998-01-01

    Oxidative stress appears to contribute to neuronal dysfunction associated with Alzheimer's disease and other CNS neurodegenerative disorders. This investigation examined if oxidative stress might contribute to impairments in cholinergic receptor-linked signaling systems and if intracellular glutathione levels modulated responses to oxidative stress. To do this the activation of the AP-1 and NF-kappaB transcription factors and of the phosphoinositide second-messenger system was measured in human neuroblastoma SH-SY5Y cells after exposure to the oxidants H2O2 or diamide, with or without prior depletion of cellular glutathione. H2O2 concentration-dependently inhibited carbachol-stimulated AP-1 activation and this inhibition was potentiated in glutathione-depleted cells. Carbachol-stimulated NF-kappaB activation was unaffected by H2O2 unless glutathione was depleted, in which case there was a H2O2 concentration-dependent inhibition. Glutathione depletion also potentiated the inhibition by H2O2 of carbachol- or G-protein (NaF)-stimulated phosphoinositide hydrolysis, whereas phospholipase C activated by the calcium ionophore ionomycin was not inhibited. The thiol-oxidizing agent diamide also inhibited phosphoinositide hydrolysis stimulated by carbachol or NaF, and glutathione depletion potentiated the diamide concentration-dependent inhibition. Unlike H2O2, diamide also inhibited ionomycin-stimulated phosphoinositide hydrolysis. Activation of both AP-1 and NF-kappaB stimulated by carbachol was inhibited by diamide, and glutathione depletion potentiated the inhibitory effects of diamide. Thus, diamide inhibited a wider range of signaling processes than did H2O2, but glutathione depletion increased the susceptibility of phosphoinositide hydrolysis and of transcription factor activation to inhibition by both H2O2 and diamide. These results demonstrate that the vulnerability of signaling systems to oxidative stress is influenced by intracellular glutathione levels

  17. A pilot study to examine the relationships of dyspnoea, physical activity and fatigue in patients with chronic obstructive pulmonary disease.

    PubMed

    Woo, K

    2000-07-01

    A descriptive-correlational design was used to examine the relationships between dyspnoea, physical activity, and fatigue in patients with chronic obstructive pulmonary disease (COPD). Lazarus and Folkman's theory of stress, appraisal, and coping provided a framework to guide the study. Dyspnoea was measured by a vertical visual analogue scale, fatigue by the Fatigue subscale of the Profile of Mood States, and physical activity by the six-minute walk (6 MW) test and an open-ended question. A convenience sample of seven male and 15 female patients with COPD provided data for analysis. The sample was characterized by relatively high forced expiratory volume in one second (FEV1) indicating mild lung impairment and high mean levels of fatigue and dyspnoea. No significant gender difference was found in the ratings of dyspnoea and fatigue and the 6 MW distance. Dyspnoea, physical activities, and fatigue were all significantly inter-related (P < 0.001). Results indicated that the higher the dyspnoea scores, the shorter the 6 MW distance walked, and the higher the fatigue scores. Limitations and suggestions for nursing practice and future research are presented.

  18. Nitrous oxide (N2O): the dominant ozone-depleting substance emitted in the 21st century.

    PubMed

    Ravishankara, A R; Daniel, John S; Portmann, Robert W

    2009-10-01

    By comparing the ozone depletion potential-weighted anthropogenic emissions of N2O with those of other ozone-depleting substances, we show that N2O emission currently is the single most important ozone-depleting emission and is expected to remain the largest throughout the 21st century. N2O is unregulated by the Montreal Protocol. Limiting future N2O emissions would enhance the recovery of the ozone layer from its depleted state and would also reduce the anthropogenic forcing of the climate system, representing a win-win for both ozone and climate.

  19. Blood flow of the submandibular gland in sodium-depleted and -loaded rats: effect of nitric oxide synthase inhibition.

    PubMed

    Vág, J; Hably, C; Csabai, Z; Tost, H; Bartha, J; Fazekas, A

    1998-08-01

    The present investigations were designed to study the hemodynamic effects of different sodium diets in the submandibular gland of rats with or without nitric oxide (NO) synthesis inhibition. Experimental animals were kept on: (1) standard chow and tap water ad libitum (normal group, N), or (2) wheat and distilled water ad libitum for 4 weeks (sodium-depleted animals, SD), or (3) standard chow and saline ad libitum for 4 weeks (sodium-loaded animals, SL). NO synthase was inhibited by N omega-nitro-L-arginine-methyl-ester (L-NAME, 10 mg/kg per day) in the last week. The rats were anesthetized, and blood pressure, cardiac output (Stewart-Hamilton's principle) and blood flow (BF) of the submandibular gland (Sapirstein's technique) were determined. High sodium intake resulted in a 47% increase of glandular BF as compared to BF measured in the control group. In all groups L-NAME decreased BF (ml/min per 100 g gland) as compared to those of rats with no L-NAME treatment (N: 76.4 +/- 15.4 vs. 56.0 +/- 11.6, P < 0.05; SD: 71.0 +/- 17.7 vs. 56.2 +/- 15.1, n.s.; SL: 112 +/- 29.4 vs. 66.9 +/- 18.4, P < 0.001), whereas the vascular resistance (VR, mm Hg x ml-1 x s x kg-1) increased (N: 11.0 +/- 2.3 vs. 17.5 +/- 4.1, P < 0.001; SD: 11.0 +/- 2.7 vs. 17.0 +/- 4.2, P < 0.01; SL: 8.5 +/- 2.4 vs. 14.9 +/- 4.6, P < 0.001). The increase in VR after L-NAME treatment was 64% in normal, 55% in sodium-depleted and 75% in sodium-loaded rats. Our results suggest that NO takes part in the regulation of vascular resistance and BF in the submandibular gland. Sodium load itself increases BF of the submandibular gland and this phenomenon may partly be mediated by NO.

  20. Mechanisms to dyspnoea and dynamic hyperinflation related exercise intolerance in COPD.

    PubMed

    Varga, Janos

    2015-06-01

    Expiratory flow limitation can develop in parallel with the progression of COPD, and as a consequence, dynamic hyperinflation and lung mechanical abnormalities can develop. Dynamic hyperinflation can cause increased breathlessness and reduction in exercise tolerance. Achievement of critical inspiratory reserve volume is one of the main factors in exercise intolerance. Obesity has specific lung mechanical effects. There is also a difference concerning gender and dyspnoea. Increased nerve activity is characteristic in hyperinflation. Bronchodilator therapy, lung volume reduction surgery, endurance training at submaximal intensity, and heliox or oxygen breathing can decrease the degree of dynamic hyperinflation.

  1. Infiltrative laryngeal lipoma in a Yorkshire Terrier as cause of severe dyspnoea.

    PubMed

    Brunnberg, M; Cinquoncie, S; Burger, M; Plog, S; Nakladal, B

    2013-01-01

    A 10-year-old Yorkshire Terrier with suspected laryngeal paralysis was referred for further examination and surgical treatment. The dog displayed severe dyspnoea and dysphonia. Ventrolateral to the larynx a soft-elastic mass of 2 cm diameter was palpated and confirmed by radiography. Histopathological examination of the resected mass revealed an infiltrative lipoma/lipoma. Although the dog totally recovered after surgery, the prognosis remains guarded due to the high risk of a recurrence. Tumours of the larynx in general and an infiltrative lipoma specifically should be added to the list of differential diagnosis in dogs presented with clinical signs that could be misinterpreted as laryngeal paralysis.

  2. Endogenous opioids modify dyspnoea during treadmill exercise in patients with COPD.

    PubMed

    Mahler, D A; Murray, J A; Waterman, L A; Ward, J; Kraemer, W J; Zhang, X; Baird, J C

    2009-04-01

    Exogenous opioid drugs, such as morphine, relieve breathlessness. The present study hypothesis was that endogenous opioids, released during the stress of exercise, modify dyspnoea in patients with chronic obstructive pulmonary disease. After familiarisation, patients performed an incremental treadmill exercise test followed by constant work on the treadmill for 10 min. At subsequent visits (2 to 3 days apart), patients received two puffs of albuterol, had a catheter placed in an arm vein for removal of blood to measure beta-endorphin immunoreactivity, received normal saline or 10 mg of naloxone intravenously in randomised order, and then performed high-intensity constant work rate exercise on the treadmill. The mean+/-sd age of the 17 patients (eight females and nine males) was 63+/-7 yrs, and post-bronchodilator forced expiratory volume in one second was 50+/-17% predicted. In both conditions, beta-endorphin levels increased three-fold from rest to end-exercise. The regression slope of breathlessness as a function of oxygen consumption (primary outcome), mean ratings of breathlessness throughout exercise and peak ratings of breathlessness were significantly higher with naloxone than normal saline. There were no differences in physiological responses throughout exercise between conditions. In conclusion, endogenous opioids modify dyspnoea during treadmill exercise in patients with chronic obstructive pulmonary disease by apparent alteration of central perception. PMID:19213787

  3. INFORMATION: Management Alert on Environmental Management's Select Strategy for Disposition of Savannah River Site Depleted Uranium Oxides

    SciTech Connect

    2010-04-01

    The Administration and the Congress, through policy statements and passage of the American Recovery and Reinvestment Act of 2009 (Recovery Act), have signaled that they hope that proactive actions by agency Inspectors General will help ensure that Federal Recovery Act activities are transparent, effective and efficient. In that context, the purpose of this management alert is to share with you concerns that have been raised to the Office of Inspector General regarding the planned disposition of the Savannah River Site's (SRS) inventory of Depleted Uranium (DU) oxides. This inventory, generated as a by-product of the nuclear weapons production process and amounting to approximately 15,600 drums of DU oxides, has been stored at SRS for decades. A Department source we deem reliable and credible recently came to the Office of Inspector General expressing concern that imminent actions are planned that may not provide for the most cost effective disposition of these materials. During April 2009, the Department chose to use funds provided under the Recovery Act to accelerate final disposition of the SRS inventory of DU oxides. After coordination with State of Utah regulators, elected officials and the U.S. Nuclear Regulatory Commission, the Department initiated a campaign to ship the material to a facility operated by EnergySolutions in Clive, Utah. Although one shipment of a portion of the material has already been sent to the EnergySolutions facility, the majority of the product remains at SRS. As had been planned, both for the shipment already made and those planned in the near term, the EnergySolutions facility was to have been the final disposal location for the material. Recently, a member of Congress and various Utah State officials raised questions regarding the radioactive and other constituents present in the DU oxides to be disposed of at the Clive, Utah, facility. These concerns revolved around the characterization of the material and its acceptability under

  4. Sustained accumulation of prelamin A and depletion of lamin A/C both cause oxidative stress and mitochondrial dysfunction but induce different cell fates.

    PubMed

    Sieprath, Tom; Corne, Tobias D J; Nooteboom, Marco; Grootaert, Charlotte; Rajkovic, Andreja; Buysschaert, Benjamin; Robijns, Joke; Broers, Jos L V; Ramaekers, Frans C S; Koopman, Werner J H; Willems, Peter H G M; De Vos, Winnok H

    2015-01-01

    The cell nucleus is structurally and functionally organized by lamins, intermediate filament proteins that form the nuclear lamina. Point mutations in genes that encode a specific subset of lamins, the A-type lamins, cause a spectrum of diseases termed laminopathies. Recent evidence points to a role for A-type lamins in intracellular redox homeostasis. To determine whether lamin A/C depletion and prelamin A accumulation differentially induce oxidative stress, we have performed a quantitative microscopy-based analysis of reactive oxygen species (ROS) levels and mitochondrial membrane potential (Δψm) in human fibroblasts subjected to sustained siRNA-mediated knockdown of LMNA and ZMPSTE24, respectively. We measured a highly significant increase in basal ROS levels and an even more prominent rise of induced ROS levels in lamin A/C depleted cells, eventually resulting in Δψm hyperpolarization and apoptosis. Depletion of ZMPSTE24 on the other hand, triggered a senescence pathway that was associated with moderately increased ROS levels and a transient Δψm depolarization. Both knockdowns were accompanied by an upregulation of several ROS detoxifying enzymes. Taken together, our data suggest that both persistent prelamin A accumulation and lamin A/C depletion elevate ROS levels, but to a different extent and with different effects on cell fate. This may contribute to the variety of disease phenotypes witnessed in laminopathies.

  5. Sustained accumulation of prelamin A and depletion of lamin A/C both cause oxidative stress and mitochondrial dysfunction but induce different cell fates

    PubMed Central

    Sieprath, Tom; Corne, Tobias DJ; Nooteboom, Marco; Grootaert, Charlotte; Rajkovic, Andreja; Buysschaert, Benjamin; Robijns, Joke; Broers, Jos LV; Ramaekers, Frans CS; Koopman, Werner JH; Willems, Peter HGM; De Vos, Winnok H

    2015-01-01

    The cell nucleus is structurally and functionally organized by lamins, intermediate filament proteins that form the nuclear lamina. Point mutations in genes that encode a specific subset of lamins, the A-type lamins, cause a spectrum of diseases termed laminopathies. Recent evidence points to a role for A-type lamins in intracellular redox homeostasis. To determine whether lamin A/C depletion and prelamin A accumulation differentially induce oxidative stress, we have performed a quantitative microscopy-based analysis of reactive oxygen species (ROS) levels and mitochondrial membrane potential (Δψm) in human fibroblasts subjected to sustained siRNA-mediated knockdown of LMNA and ZMPSTE24, respectively. We measured a highly significant increase in basal ROS levels and an even more prominent rise of induced ROS levels in lamin A/C depleted cells, eventually resulting in Δψm hyperpolarization and apoptosis. Depletion of ZMPSTE24 on the other hand, triggered a senescence pathway that was associated with moderately increased ROS levels and a transient Δψm depolarization. Both knockdowns were accompanied by an upregulation of several ROS detoxifying enzymes. Taken together, our data suggest that both persistent prelamin A accumulation and lamin A/C depletion elevate ROS levels, but to a different extent and with different effects on cell fate. This may contribute to the variety of disease phenotypes witnessed in laminopathies. PMID:25996284

  6. Different B-type methionine sulfoxide reductases in Chlamydomonas may protect the alga against high-light, sulfur-depletion, or oxidative stress.

    PubMed

    Zhao, Lei; Chen, Mei; Cheng, Dongmei; Yang, Haomeng; Sun, Yongle; Zhou, Heyi; Huang, Fang

    2013-11-01

    The genome of unicellular green alga Chlamydomonas reinhardtii contains four genes encoding B-type methionine sulfoxide reductases, MSRB1.1, MSRB1.2, MSRB2.1, and MSRB2.2, with functions largely unknown. To understand the cell defense system mediated by the methionine sulfoxide reductases in Chlamydomonas, we analyzed expression and physiological roles of the MSRBs under different abiotic stress conditions using immunoblotting and quantitative polymerase chain reaction (PCR) analyses. We showed that the MSRB2.2 protein was accumulated in cells treated with high light (1,300 µE/m² per s), whereas MSRB1.1 was accumulated in the cells under 1 mmol/L H₂O₂ treatment or sulfur depletion. We observed that the cells with the MSRB2.2 knockdown and overexpression displayed increased and decreased sensitivity to high light, respectively, based on in situ chlorophyll a fluorescence measures. We also observed that the cells with the MSRB1.1 knockdown and overexpression displayed decreased and increased tolerance to sulfur-depletion and oxidative stresses, respectively, based on growth and H₂-producing performance. The physiological implications revealed from the experimental data highlight the importance of MSRB2.2 and MSRB1.1 in protecting Chlamydomonas cells against adverse conditions such as high-light, sulfur-depletion, and oxidative stresses.

  7. Different B-type methionine sulfoxide reductases in Chlamydomonas may protect the alga against high-light, sulfur-depletion, or oxidative stress.

    PubMed

    Zhao, Lei; Chen, Mei; Cheng, Dongmei; Yang, Haomeng; Sun, Yongle; Zhou, Heyi; Huang, Fang

    2013-11-01

    The genome of unicellular green alga Chlamydomonas reinhardtii contains four genes encoding B-type methionine sulfoxide reductases, MSRB1.1, MSRB1.2, MSRB2.1, and MSRB2.2, with functions largely unknown. To understand the cell defense system mediated by the methionine sulfoxide reductases in Chlamydomonas, we analyzed expression and physiological roles of the MSRBs under different abiotic stress conditions using immunoblotting and quantitative polymerase chain reaction (PCR) analyses. We showed that the MSRB2.2 protein was accumulated in cells treated with high light (1,300 µE/m² per s), whereas MSRB1.1 was accumulated in the cells under 1 mmol/L H₂O₂ treatment or sulfur depletion. We observed that the cells with the MSRB2.2 knockdown and overexpression displayed increased and decreased sensitivity to high light, respectively, based on in situ chlorophyll a fluorescence measures. We also observed that the cells with the MSRB1.1 knockdown and overexpression displayed decreased and increased tolerance to sulfur-depletion and oxidative stresses, respectively, based on growth and H₂-producing performance. The physiological implications revealed from the experimental data highlight the importance of MSRB2.2 and MSRB1.1 in protecting Chlamydomonas cells against adverse conditions such as high-light, sulfur-depletion, and oxidative stresses. PMID:24034412

  8. Variability of within-breath reactance in COPD patients and its association with dyspnoea.

    PubMed

    Aarli, Bernt B; Calverley, Peter M A; Jensen, Robert L; Eagan, Tomas M L; Bakke, Per S; Hardie, Jon A

    2015-03-01

    The forced oscillation technique can identify expiratory flow limitation (EFL) when a large difference in inspiratory and expiratory reactance (ΔXrs) occurs. However, flow limitation can vary from breath to breath, and so we compared a multiple-breath ΔXrs approach to the traditional breath-by-breath assessment of EFL. We investigated the within- and between-day reproducibility and the factors that affect the size of ΔXrs when used as a continuous measurement over multiple breaths. In addition, we examined how multiple-breath ΔXrs relates to the sensation of breathlessness. 425 moderate to very severe chronic obstructive pulmonary disease (COPD) patients and 229 controls were included. Spirometry and impedance measurements were performed on a MasterScope CT Impulse Oscillation System. Median ΔXrs approached zero in healthy controls with little variation between measurements. COPD patients generally had higher ΔXrs and higher variability. The COPD patients with ΔXrs >0.1 kPa · L(-1) · s(-1) were prone to be more breathless and had a higher modified Medical Research Council dyspnoea scale score. In controls, the 95th percentile of ΔXrs was as low as 0.07 kPa · L(-1) · s(-1). We describe a new method to assess EFL at a patient level and propose a cut-off, mean ΔXrs >0.1 kPa · L(-1) · s(-1), as a way to identify COPD patients who are more likely to report dyspnoea.

  9. Variability of within-breath reactance in COPD patients and its association with dyspnoea.

    PubMed

    Aarli, Bernt B; Calverley, Peter M A; Jensen, Robert L; Eagan, Tomas M L; Bakke, Per S; Hardie, Jon A

    2015-03-01

    The forced oscillation technique can identify expiratory flow limitation (EFL) when a large difference in inspiratory and expiratory reactance (ΔXrs) occurs. However, flow limitation can vary from breath to breath, and so we compared a multiple-breath ΔXrs approach to the traditional breath-by-breath assessment of EFL. We investigated the within- and between-day reproducibility and the factors that affect the size of ΔXrs when used as a continuous measurement over multiple breaths. In addition, we examined how multiple-breath ΔXrs relates to the sensation of breathlessness. 425 moderate to very severe chronic obstructive pulmonary disease (COPD) patients and 229 controls were included. Spirometry and impedance measurements were performed on a MasterScope CT Impulse Oscillation System. Median ΔXrs approached zero in healthy controls with little variation between measurements. COPD patients generally had higher ΔXrs and higher variability. The COPD patients with ΔXrs >0.1 kPa · L(-1) · s(-1) were prone to be more breathless and had a higher modified Medical Research Council dyspnoea scale score. In controls, the 95th percentile of ΔXrs was as low as 0.07 kPa · L(-1) · s(-1). We describe a new method to assess EFL at a patient level and propose a cut-off, mean ΔXrs >0.1 kPa · L(-1) · s(-1), as a way to identify COPD patients who are more likely to report dyspnoea. PMID:25359342

  10. Heat shock pretreatment may protect against heatstroke-induced circulatory shock and cerebral ischemia by reducing oxidative stress and energy depletion.

    PubMed

    Wang, Jui-Ling; Ke, Der-Shin; Lin, Mao-Tsun

    2005-02-01

    The mechanisms underlying the protective effects of heat shock pretreatment on heatstroke remain unclear. Here we attempted to ascertain whether the possible occurrence of oxidative stress and energy depletion exhibited during heatstroke can be reduced by heat shock preconditioning. In the present study, colonic temperature, mean arterial pressure, heart rate, striatal levels of heat shock protein 72 (HSP72), local Po2, brain temperature, cerebral blood flow, cellular ischemia and damage markers, dihydroxybenzoic acid (DHBA), lipid peroxidation, glutathione, glutathione peroxidase and reductase activities, and ATP were assayed in normothermic control rats and in heatstroke rats with or without preconditioning 16 or 96 h before initiation of heatstroke. Heatstroke was induced by exposing the anesthetized rats to a high ambient temperature (Ta = 43 degrees C) until the moment at which MAP decreased from its peak level. Sublethal heat shock pretreatment 16 h before initiation of heatstroke, in addition to increasing striatal HSP72 levels, conferred significant protection against heatstroke-induced arterial hypotension, striatal ischemia and damage, increment of hydroxyl radical formation, lipid peroxidation, glutathione oxidation, and decrement of glutathione peroxidase activity and ATP. However, at 96 h after heat shock, when striatal HSP72 expression returned to basal levels, the above responses that occurred during onset of heatstroke were indistinguishable between the two groups. These results suggest that heat shock pretreatment induces HSP72 overexpression in striatum and confers protection against heatstroke-induced striatal ischemia and damage by reducing oxidative stress and energy depletion.

  11. Green tea polyphenol (-)-epigallocatechin-3-gallate treatment to mouse skin prevents UVB-induced infiltration of leukocytes, depletion of antigen-presenting cells, and oxidative stress.

    PubMed

    Katiyar, S K; Mukhtar, H

    2001-05-01

    Ultraviolet (UV) radiation-induced infiltrating leukocytes, depletion of antigen-presenting cells, and oxidative stress in the skin play an important role in the induction of immune suppression and photocarcinogenesis. Earlier we have shown that topical application of polyphenols from green tea or its major chemopreventive constituent (-)-epigallocatechin-3-gallate (EGCG) prevents UV-B-induced immunosuppression in mice. To define the mechanism of prevention, we found that topical application of EGCG (3 mg/mouse/3 cm(2) of skin area) to C3H/HeN mice before a single dose of UV-B (90 mJ/cm(2)) exposure inhibited UV-B-induced infiltration of leukocytes, specifically the CD11b+ cell type, and myeloperoxidase activity, a marker of tissue infiltration of leukocytes. EGCG treatment was also found to prevent UV-B-induced depletion in the number of antigen-presenting cells when immunohistochemically detected as class II MHC+ Ia+ cells. UV-B-induced infiltrating cell production of H2O2 and nitric oxide (NO) was determined as a marker of oxidative stress. We found that pretreatment of EGCG decreased the number of UV-B-induced increases in H2O2-producing cells and inducible nitric oxide synthase-expressing cells and the production of H2O2 and NO in both epidermis and dermis at a UV-B-irradiated site. Together, these data suggest that prevention of UV-B-induced infiltrating leukocytes, antigen-presenting cells, and oxidative stress by EGCG treatment of mouse skin may be associated with the prevention of UV-B-induced immunosuppression and photocarcinogenesis.

  12. Diagnostic and Prognostic Properties of Osteoprotegerin in Patients with Acute Dyspnoea: Observations from the Akershus Cardiac Examination (ACE) 2 Study

    PubMed Central

    Pervez, Mohammed Osman; Pedersen, Marit Holmefjord; Brynildsen, Jon; Høiseth, Arne Didrik; Hagve, Tor-Arne; Røsjø, Helge; Omland, Torbjørn

    2016-01-01

    Background Circulating osteoprotegerin (OPG) levels are increased in patients with chronic heart failure (HF). The diagnostic and prognostic merit of OPG measurement in patients admitted with acute dyspnoea is unknown. Objectives To evaluate the diagnostic and prognostic value of measuring OPG in patients admitted to hospital with acute dyspnoea. Methods OPG was analysed by ELISA in 308 patients admitted due to acute dyspnoea. Investigators blinded to OPG results adjudicated the diagnosis for the index hospitalization. Clinical outcomes were obtained from hospital records. Results In total, 139 patients (45%) were hospitalized with acute HF. OPG levels on hospital admission were higher in patients with acute HF vs. no acute HF, 7.8 (5.5–10.4) vs. 5.4 (3.8–7.2) pmol/L, p<0.001. The area under the receiver operator characteristic curve (ROC AUC) of OPG to discriminate between HF vs. non-HF was 0.695 [95% CI 0.636–0.754]. OPG did not provide incremental information to the ED physician’s prediction or N-terminal pro-B-type natriuretic peptide regarding the diagnosis of acute HF. OPG levels (log transformed) were associated with mortality in crude analysis (HR (95% CI) 1.87 (1.34 to 2.61), p<0.001), but this association was attenuated and no longer significant after including established cardiac biomarkers into the model. Conclusion In patients admitted to hospital with acute dyspnoea, OPG levels are higher in patients with acute HF than in those with dyspnoea from other causes. However, OPG does not provide incremental information beyond ED physician assessment for the diagnosis of acute HF or beyond clinical risk variables and established cardiac biomarkers concerning prognosis. PMID:27463973

  13. Enhanced Radiation Sensitivity in Short-Channel Partially Depleted Silicon-on-Insulator n-Type Metal-Oxide-Semiconductor Field Effect Transistors

    NASA Astrophysics Data System (ADS)

    Peng, Chao; Zhang, Zheng-Xuan; Hu, Zhi-Yuan; Huang, Hui-Xiang; Ning, Bing-Xu; Bi, Da-Wei

    2013-09-01

    The total ionizing dose effects of partially depleted silicon-on-insulator (SOI) transistors in a 0.13 μm technology are studied by 60Co γ-ray irradiation. Radiation enhanced drain-induced barrier lowering (DIBL) under different bias conditions is related to the parasitic bipolar in the SOI transistor and oxide trapped charge in the buried oxide, and it is experimentally observed for short channel transistors. The enhanced DIBL effect manifests as the DIBL parameter increases with total dose. Body doping concentration is a key factor affecting the total ionizing dose effect of the transistor. The low body doping transistor exhibits not only significant front gate threshold voltage shift as a result of the coupling effect, but also great off-state leakage at high drain voltage due to the enhanced DIBL effect.

  14. Troxerutin protects against 2,2',4,4'-tetrabromodiphenyl ether (BDE-47)-induced liver inflammation by attenuating oxidative stress-mediated NAD⁺-depletion.

    PubMed

    Zhang, Zi-Feng; Zhang, Yan-Qiu; Fan, Shao-Hua; Zhuang, Juan; Zheng, Yuan-Lin; Lu, Jun; Wu, Dong-Mei; Shan, Qun; Hu, Bin

    2015-01-01

    Emerging evidence indicates that 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) induces liver injury through enhanced ROS production and lymphocytic infiltration, which may promote a liver inflammatory response. Antioxidants have been reported to attenuate the cellular toxicity associated with polybrominated diphenyl ethers (PBDEs). In this study, we investigated the effect of troxerutin, a trihydroxyethylated derivative of the natural bioflavonoid rutin, on BDE-47-induced liver inflammation and explored the potential mechanisms underlying this effect. Our results showed that NAD(+)-depletion was involved in the oxidative stress-mediated liver injury in a BDE-47 treated mouse model, which was confirmed by Vitamin E treatment. Furthermore, our data revealed that troxerutin effectively alleviated liver inflammation by mitigating oxidative stress-mediated NAD(+)-depletion in BDE-47 treated mice. Consequently, troxerutin remarkably restored SirT1 protein expression and activity in the livers of BDE-47-treated mice. Mechanistically, troxerutin dramatically repressed the nuclear translocation of NF-κB p65 and the acetylation of NF-κB p65 (Lys 310) and Histone H3 (Lys9) to abate the transcription of inflammatory genes in BDE-47-treated mouse livers. These inhibitory effects of troxerutin were markedly blunted by EX527 (SirT1 inhibitor) treatment. This study provides novel mechanistic insights into the toxicity of BDE-47 and indicates that troxerutin might be used in the prevention and therapy of BDE-47-induced hepatotoxicity.

  15. The assessment of breathlessness in pulmonary arterial hypertension: reliability and validity of the Dyspnoea-12.

    PubMed

    Yorke, Janelle; Armstrong, Iain

    2014-12-01

    Breathlessness is a cardinal symptom of pulmonary arterial hypertension (PAH); yet no breathlessness instrument has been previously tested for reliability and validity for this population. Using a cross-sectional design, we tested the psychometric properties of the Dyspnoea-12 (D-12), for the assessment of breathlessness in PAH. Pearson's correlations with World Health Organization functional class (WHO FC), Minnesota Living with Heart failure - pulmonary hypertension modified version (MLHF-PH), Hospital Anxiety and Depression scale (HADS) and 6-minute walk distance test (6MWD) were conducted. Participants (n = 176) were mostly female (70.5%), mean age 54.3±14 years; diagnosed with idiopathic PAH (48.9%), congenital heart disease (27.8%) and connective tissue disease (23.3%); and most were WHO FC II (32.4%) and III (52.3%). The D-12 showed excellent internal consistency for the total and two-component scores for physical and emotional (Cronbach's α 0.95, 0.93 and 0.94, respectively). D-12 total score was significantly associated with MLHF-PH (r = 0.70), HADS (anxiety r = 0.54 and depression r = 0.68), WHO FC (r = 0.49), and 6MWD (r = -0.26). In patients with PAH, the D-12 - a short patient reported measure of breathlessness severity that taps the physical and emotional components, is a reliable and valid instrument.

  16. Ultra-thin body & buried oxide SOI substrate development and qualification for Fully Depleted SOI device with back bias capability

    NASA Astrophysics Data System (ADS)

    Schwarzenbach, Walter; Nguyen, Bich-Yen; Allibert, Frederic; Girard, Christophe; Maleville, Christophe

    2016-03-01

    This paper reviews the properties of the SOI wafers fabricated using the Smart Cut™ technology, with ultra-thin body and buried oxide (BOX) required for the FD-SOI CMOS platform. It focuses on the parameters that require specific attention for this technology, namely, the top silicon layer thickness uniformity and buried oxide reliability. The first one is linked to the threshold voltage variability and the second to the active role played by the BOX when a back-bias is used. An overview of the specific process optimization and metrology developed to achieve the targeted specifications is given.

  17. Evidence of Highly Conserved β-Crystallin Disulfidome that Can be Mimicked by In Vitro Oxidation in Age-related Human Cataract and Glutathione Depleted Mouse Lens.

    PubMed

    Fan, Xingjun; Zhou, Sheng; Wang, Benlian; Hom, Grant; Guo, Minfei; Li, Binbin; Yang, Jing; Vaysburg, Dennis; Monnier, Vincent M

    2015-12-01

    Low glutathione levels are associated with crystallin oxidation in age-related nuclear cataract. To understand the role of cysteine residue oxidation, we used the novel approach of comparing human cataracts with glutathione-depleted LEGSKO mouse lenses for intra- versus intermolecular disulfide crosslinks using 2D-PAGE and proteomics, and then systematically identified in vivo and in vitro all disulfide forming sites using ICAT labeling method coupled with proteomics. Crystallins rich in intramolecular disulfides were abundant at young age in human and WT mouse lens but shifted to multimeric intermolecular disulfides at older age. The shift was ∼4x accelerated in LEGSKO lens. Most cysteine disulfides in β-crystallins (except βA4 in human) were highly conserved in mouse and human and could be generated by oxidation with H(2)O(2), whereas γ-crystallin oxidation selectively affected γC23/42/79/80/154, γD42/33, and γS83/115/130 in human cataracts, and γB79/80/110, γD19/109, γF19/79, γE19, γS83/130, and γN26/128 in mouse. Analysis based on available crystal structure suggests that conformational changes are needed to expose Cys42, Cys79/80, Cys154 in γC; Cys42, Cys33 in γD, and Cys83, Cys115, and Cys130 in γS. In conclusion, the β-crystallin disulfidome is highly conserved in age-related nuclear cataract and LEGSKO mouse, and reproducible by in vitro oxidation, whereas some of the disulfide formation sites in γ-crystallins necessitate prior conformational changes. Overall, the LEGSKO mouse model is closely reminiscent of age-related nuclear cataract.

  18. Meat processing and colon carcinogenesis: cooked, nitrite-treated, and oxidized high-heme cured meat promotes mucin-depleted foci in rats

    PubMed Central

    Santarelli, Raphaëlle L; Vendeuvre, Jean-Luc; Naud, Nathalie; Taché, Sylviane; Guéraud, Françoise; Viau, Michelle; Genot, Claude; Corpet, Denis E; Pierre, Fabrice H F

    2010-01-01

    Processed meat intake is associated with colorectal cancer risk, but no experimental study supports the epidemiologic evidence. To study the effect of meat processing on carcinogenesis promotion, we first did a 14-day study with 16 models of cured meat. Studied factors, in a 2 × 2 × 2 × 2 design, were muscle color (a proxy for heme level), processing temperature, added nitrite, and packaging. Fischer 344 rats were fed these 16 diets, and we evaluated fecal and urinary fat oxidation and cytotoxicity, three biomarkers of heme-induced carcinogenesis promotion. A principal component analysis allowed for selection of four cured meats for inclusion into a promotion study. These selected diets were given for 100 days to rats pretreated with 1,2-dimethylhydrazine. Colons were scored for preneoplastic lesions: aberrant crypt foci (ACF) and mucin-depleted foci (MDF). Cured meat diets significantly increased the number of ACF/colon compared with a no-meat control diet (P = 0.002). Only the cooked nitrite-treated and oxidized high heme meat significantly increased the fecal level of apparent total N-nitroso compounds (ATNC) and the number of MDF per colon compared with the no-meat control diet (P < 0.05). This nitrite-treated and oxidized cured meat specifically increased the MDF number compared with similar non nitrite-treated meat (P = 0.03) and with similar non oxidized meat (P = 0.004). Thus, a model cured meat, similar to ham stored aerobically, increased the number of preneoplastic lesions, which suggests colon carcinogenesis promotion. Nitrite treatment and oxidation increased this promoting effect, which was linked with increased fecal ATNC level. This study could lead to process modifications to make non promoting processed meat. PMID:20530708

  19. Scaling characteristics of depletion type, fully transparent amorphous indium-gallium-zinc-oxide thin-film transistors and inverters following Ar plasma treatment

    NASA Astrophysics Data System (ADS)

    Kim, Joonwoo; Jeong, Soon Moon; Jeong, Jaewook

    2015-11-01

    We fabricated depletion type, transparent amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) and inverters with an Ar plasma treatment and analyzed their scaling characteristics with channel lengths ranging from 2 to 100 µm. The improvement of the field-effect mobility of a-IGZO TFTs is apparent only for short channel lengths. There is also an unexpected side effect of the Ar plasma treatment, which introduces back-channel interfacial states and induces a positive shift in the threshold voltage of a-IGZO TFTs. The resulting increase in the field-effect mobility and the positive shift in the threshold voltage of each TFT increase the differential gain up to 3 times and the positive shift in the transient point of the transparent inverters.

  20. Grain orientations and distribution of Y2Ba4CuUOx phase in melt-textured YBCO with addition of depleted uranium oxide studied by EBSD

    NASA Astrophysics Data System (ADS)

    Koblischka-Veneva, A.; Mücklich, F.; Koblischka, M. R.; Babu, N. Hari; Cardwell, D. A.; Murakami, M.

    2006-07-01

    The local grain orientations and the distribution of Y2Ba4CuUOx (U-2411) phase are measured within melt-textured YBCO samples by means of electron backscatter diffraction (EBSD). In this work, several samples with varying addition (0.1-0.8 wt%) of depleted uranium oxide (DU) were analysed by means of EBSD. The embedded U-2411 particles were found to have sizes around 200 nm, some large particles being present in the samples with a high DU concentration. Combined EBSD and EDX analysis enabled the identification of the Kikuchi patterns of the U-2411 phase, so that a true three-phase EBSD scan (YBCO, Y2BaCuO5 and U-2411) becomes possible.

  1. Superconductivity-induced magnetization depletion in a ferromagnet through an insulator in a ferromagnet-insulator-superconductor hybrid oxide heterostructure.

    PubMed

    Prajapat, C L; Singh, Surendra; Paul, Amitesh; Bhattacharya, D; Singh, M R; Mattauch, S; Ravikumar, G; Basu, S

    2016-05-21

    Coupling between superconducting and ferromagnetic states in hybrid oxide heterostructures is presently a topic of intense research. Such a coupling is due to the leakage of the Cooper pairs into the ferromagnet. However, tunneling of the Cooper pairs though an insulator was never considered plausible. Using depth sensitive polarized neutron reflectivity we demonstrate the coupling between superconductor and magnetic layers in epitaxial La2/3Ca1/3MnO3 (LCMO)/SrTiO3/YBa2Cu3O7-δ (YBCO) hybrid heterostructures, with SrTiO3 as an intervening oxide insulator layer between the ferromagnet and the superconductor. Measurements above and below the superconducting transition temperature (TSC) of YBCO demonstrate a large modulation of magnetization in the ferromagnetic layer below the TSC of YBCO in these heterostructures. This work highlights a unique tunneling phenomenon between the epitaxial layers of an oxide superconductor (YBCO) and a magnetic layer (LCMO) through an insulating layer. Our work would inspire further investigations on the fundamental aspect of a long range order of the triplet spin-pairing in hybrid structures.

  2. Depletion of cytosolic or mitochondrial thioredoxin increases CYP2E1 induced oxidative stress via an ASK-1-JNK1 pathway in HepG2 cells

    PubMed Central

    Yang, Lili; Wu, Defeng; Wang, Xiaodong; Cederbaum, Arthur I

    2011-01-01

    Thioredoxin is an important reducing molecule in biological systems. Increasing CYP2E1 activity induces oxidative stress and cell toxicity. However, whether thioredoxin protects cells against CYP2E1 induced oxidative stress and toxicity is unknown. SiRNA were used to knockdown either cytosolic (TRX-1) or mitochondrial thioredoxin (TRX-2) in HepG2 cells expressing CYP2E1 (E47 cells) or without expressing CYP2E1 (C34 cells). Cell viability decreased 40–60% in E47 but not C34 cells with 80–90% knockdown of either TRX-1 or TRX-2. Depletion of either thioredoxin also potentiated the toxicity by either a glutathione synthesis inhibitor or TNFα in E47 cells. Generation of reactive oxygen species and 4-HNE protein adducts increased in E47 but not C34 cells with either thioredoxin knockdown. GSH was decreased and adding GSH completely blocked E47 cell death induced by either thioredoxin knockdown. Lowering TRX-1 or TRX-2 in E47 cells caused an early activation of ASK-1, followed by phosphorylation of JNK1 after 48 hrs of siRNA treatment. JNK inhibitor caused a partial recovery of E47 cell viability after thioredoxin knockdown. In conclusion, knockdown of TRX-1 or TRX-2 sensitizes cells to CYP2E1 induced oxidant stress partially via ASK-1 and JNK1 signaling pathways. Both TRX-1 and TRX-2 are important for defense against CYP2E1-induced oxidative stress. PMID:21557999

  3. CYP2E1 induction leads to oxidative stress and cytotoxicity in glutathione-depleted cerebellar granule neurons.

    PubMed

    Valencia-Olvera, Ana Carolina; Morán, Julio; Camacho-Carranza, Rafael; Prospéro-García, Oscar; Espinosa-Aguirre, Jesús Javier

    2014-10-01

    Increasing evidence suggests that brain cytochrome P450 (CYP) can contribute to the in situ metabolism of xenobiotics. In the liver, some xenobiotics can be metabolized by CYPs into more reactive products that can damage hepatocytes and induce cell death. In addition, normal CYP activity may produce reactive oxygen species (ROS) that contribute to cell damage through oxidative mechanisms. CYP2E1 is a CYP isoform that can generate ROS leading to cytotoxicity in multiple tissue types. The aim of this study was to determine whether CYP2E1 induction may lead to significant brain cell impairment. Immunological analysis revealed that exposure of primary cerebellar granule neuronal cultures to the CYP inducer isoniazid, increased CYP2E1 expression. In the presence of buthionine sulfoximine, an agent that reduces glutathione levels, isoniazid treatment also resulted in reactive oxygen species (ROS) production, DNA oxidation and cell death. These effects were attenuated by simultaneous exposure to diallyl sulfide, a CYP2E1 inhibitor, or to a mimetic of superoxide dismutase/catalase, (Euka). These results suggest that in cases of reduced antioxidant levels, the induction of brain CYP2E1 could represent a risk of in situ neuronal damage.

  4. CYP2E1 induction leads to oxidative stress and cytotoxicity in glutathione-depleted cerebellar granule neurons.

    PubMed

    Valencia-Olvera, Ana Carolina; Morán, Julio; Camacho-Carranza, Rafael; Prospéro-García, Oscar; Espinosa-Aguirre, Jesús Javier

    2014-10-01

    Increasing evidence suggests that brain cytochrome P450 (CYP) can contribute to the in situ metabolism of xenobiotics. In the liver, some xenobiotics can be metabolized by CYPs into more reactive products that can damage hepatocytes and induce cell death. In addition, normal CYP activity may produce reactive oxygen species (ROS) that contribute to cell damage through oxidative mechanisms. CYP2E1 is a CYP isoform that can generate ROS leading to cytotoxicity in multiple tissue types. The aim of this study was to determine whether CYP2E1 induction may lead to significant brain cell impairment. Immunological analysis revealed that exposure of primary cerebellar granule neuronal cultures to the CYP inducer isoniazid, increased CYP2E1 expression. In the presence of buthionine sulfoximine, an agent that reduces glutathione levels, isoniazid treatment also resulted in reactive oxygen species (ROS) production, DNA oxidation and cell death. These effects were attenuated by simultaneous exposure to diallyl sulfide, a CYP2E1 inhibitor, or to a mimetic of superoxide dismutase/catalase, (Euka). These results suggest that in cases of reduced antioxidant levels, the induction of brain CYP2E1 could represent a risk of in situ neuronal damage. PMID:24929095

  5. Oxidized LDL lipids increase β-amyloid production by SH-SY5Y cells through glutathione depletion and lipid raft formation.

    PubMed

    Dias, Irundika H K; Mistry, Jayna; Fell, Shaun; Reis, Ana; Spickett, Corinne M; Polidori, Maria C; Lip, Gregory Y H; Griffiths, Helen R

    2014-10-01

    Elevated total cholesterol in midlife has been associated with increased risk of dementia in later life. We have previously shown that low-density lipoprotein (LDL) is more oxidized in the plasma of dementia patients, although total cholesterol levels are not different from those of age-matched controls. β-Amyloid (Aβ) peptide, which accumulates in Alzheimer disease (AD), arises from the initial cleavage of amyloid precursor protein by β-secretase-1 (BACE1). BACE1 activity is regulated by membrane lipids and raft formation. Given the evidence for altered lipid metabolism in AD, we have investigated a mechanism for enhanced Aβ production by SH-SY5Y neuronal-like cells exposed to oxidized LDL (oxLDL). The viability of SH-SY5Y cells exposed to 4μg oxLDL and 25µM 27-hydroxycholesterol (27OH-C) was decreased significantly. Lipids, but not proteins, extracted from oxLDL were more cytotoxic than oxLDL. In parallel, the ratio of reduced glutathione (GSH) to oxidized glutathione was decreased at sublethal concentrations of lipids extracted from native and oxLDL. GSH loss was associated with an increase in acid sphingomyelinase (ASMase) activity and lipid raft formation, which could be inhibited by the ASMase inhibitor desipramine. 27OH-C and total lipids from LDL and oxLDL independently increased Aβ production by SH-SY5Y cells, and Aβ accumulation could be inhibited by desipramine and by N-acetylcysteine. These data suggest a mechanism whereby oxLDL lipids and 27OH-C can drive Aβ production by GSH depletion, ASMase-driven membrane remodeling, and BACE1 activation in neuronal cells.

  6. Effects of an aging pulmonary system on expiratory flow limitation and dyspnoea during exercise in healthy women.

    PubMed

    Wilkie, Sabrina S; Guenette, Jordan A; Dominelli, Paolo B; Sheel, A William

    2012-06-01

    Aging related changes in pulmonary function may make older women (OW) more susceptible to expiratory flow limitation (EFL) and lead to higher dyspnoea ratings during exercise relative to young women (YW). Accordingly, the purpose of this study was to compare sensory responses and EFL susceptibility and magnitude in 8 YW (29 ± 7 years) and 8 healthy OW (64 ± 3 years) matched for percentage-predicted forced vital capacity (% predicted FVC) and % predicted forced expiratory volume in 1 s. EFL was calculated as the percent overlap between tidal flow-volume loops during maximal exercise and the maximal expiratory flow-volume (MEFV) curve. Peak oxygen consumption (V'O(2peak)) was lower in the OW compared to the YW (29.4 ± 3.6 vs. 49.1 ± 8.9 ml kg(-1) min(-1), P < 0.05) as was maximal ventilation (73.7 ± 18.4 vs. 108.7 ± 14.1 l min(-1), P < 0.05). EFL at maximal exercise was present in 2 of 8 YW and in 5 of 8 OW. There were no significant differences in the magnitude of EFL between OW (23 ± 24, range: 0-69 %EFL) and YW (9 ± 18, range: 0-46 %EFL, P = 0.21). The magnitude of EFL in OW was inversely related to % predicted FVC (r = -0.69, P = 0.06), but this relationships was not observed in the YW (r = -0.23, P = 0.59). The OW consistently reported greater dyspnoea and leg discomfort for any given absolute work rate, but not when work was expressed as a percentage of maximum. Reduced ventilatory and exercise capacities may cause OW to be more susceptible to EFL during exercise and experience greater dyspnoea relative to YW for a standardized physical task.

  7. Effects of an aging pulmonary system on expiratory flow limitation and dyspnoea during exercise in healthy women.

    PubMed

    Wilkie, Sabrina S; Guenette, Jordan A; Dominelli, Paolo B; Sheel, A William

    2012-06-01

    Aging related changes in pulmonary function may make older women (OW) more susceptible to expiratory flow limitation (EFL) and lead to higher dyspnoea ratings during exercise relative to young women (YW). Accordingly, the purpose of this study was to compare sensory responses and EFL susceptibility and magnitude in 8 YW (29 ± 7 years) and 8 healthy OW (64 ± 3 years) matched for percentage-predicted forced vital capacity (% predicted FVC) and % predicted forced expiratory volume in 1 s. EFL was calculated as the percent overlap between tidal flow-volume loops during maximal exercise and the maximal expiratory flow-volume (MEFV) curve. Peak oxygen consumption (V'O(2peak)) was lower in the OW compared to the YW (29.4 ± 3.6 vs. 49.1 ± 8.9 ml kg(-1) min(-1), P < 0.05) as was maximal ventilation (73.7 ± 18.4 vs. 108.7 ± 14.1 l min(-1), P < 0.05). EFL at maximal exercise was present in 2 of 8 YW and in 5 of 8 OW. There were no significant differences in the magnitude of EFL between OW (23 ± 24, range: 0-69 %EFL) and YW (9 ± 18, range: 0-46 %EFL, P = 0.21). The magnitude of EFL in OW was inversely related to % predicted FVC (r = -0.69, P = 0.06), but this relationships was not observed in the YW (r = -0.23, P = 0.59). The OW consistently reported greater dyspnoea and leg discomfort for any given absolute work rate, but not when work was expressed as a percentage of maximum. Reduced ventilatory and exercise capacities may cause OW to be more susceptible to EFL during exercise and experience greater dyspnoea relative to YW for a standardized physical task. PMID:21971945

  8. Sensor systems for precise location of depleted uranium in soil and for enhancing the recovery of both zero valence and uranium oxides

    SciTech Connect

    Etheridge, J.A.; Monts, D.L.; Su, Y.; Waggoner, C.A.

    2007-07-01

    Depleted uranium (DU) has been the primary material used for the past two decades by the US military in armor piercing rounds. Domestic firing ranges that have been used for DU training purposes are located around the country and vary with regard to soil type, depth of vadose zone, and extent of contamination with other types of projectiles. A project is underway to develop a set of sensor systems to locate expended DU rounds and to process soil and debris to recover the material. Reactivity of zero valence DU material, even in dry sandy soils, results in rapid oxidation and diffusion of uranium minerals within the soil column. Detection techniques must be robust for both metallic and uranyl species. Radiological sensor techniques including both gamma spectroscopy and prompt gamma neutron analysis are being used in conjunction with electromagnetic imaging to locate the DU for excavation. Detection limits for both zero valence DU (ZVDU) and oxidized material will be discussed. Applicability of active and passive optical methods, such as spectral imaging and fluorescence spectroscopy, will be discussed as aids for achieving clean soil margins while excavating DU materials. Instrumentation selection for controlling processing equipment used to separate ZVDU and uranyl species from contaminated soil and debris will also be discussed. Preliminary findings for use of sodium iodide detectors and multichannel analyzer software are discussed for locating 25 and 105 mm DU penetrators. Optimum detector height of 15 cm (six inches) and detection depths up to 15 cm are discussed. A comparison of detector response of the Geonics EM61 MKII electromagnetic induction unit for DU and ferrous materials is reported. Difficulty of locating small DU penetrators using the one meter detection coil and differences in detector response for target orientation relative to the detection coil are reported. (authors)

  9. Enhancement of photoassembly of the functionally active water-oxidizing complex in Mn-depleted photosystem II membranes upon transition to anaerobic conditions.

    PubMed

    Khorobrykh, A A; Yanykin, D V; Klimov, V V

    2016-10-01

    It has been shown earlier (Khorobrykh and Klimov, 2015) that molecular oxygen is directly involved in the general mechanism of the donor side photoinhibition of photosystem II (PSII) membranes. In the present work the effect of oxygen on photoassembly ("photoactivation") of the functionally active inorganic core of the water-oxidizing complex (WOC) in Mn-depleted PSII preparations (apo-WOC-PSII) in the presence of exogenous Mn(2+), Ca(2+) as well as ferricyanide was investigated. It was revealed that the efficiency of the photoassembly of the WOC was considerably increased upon removal of oxygen from the medium during photoactivation procedure using the enzymatic oxygen trap or argon flow. The lowering of O2 concentration from 250μM to 75μM, 10μM and near 0μM results in 29%, 71% and 92%, respectively, stimulation of the rate of O2 evolution measured after the photoactivation. The increase in the intensity of light used during the photoactivation was accompanied by a decrease of both the efficiency of photoassembly of the WOC and the stimulation effect of removal of O2 (that may be due to the enhancement of the processes leading to the photodamage to PSII). It is concluded that the enhancement in photoactivation of oxygen-evolving activity of apo-WOC-PSII induced by oxygen removal from the medium is due to the suppression of the donor side photoinhibition of PSII in which molecular oxygen can be involved. PMID:27588718

  10. A Novel Step-Doping Fully-Depleted Silicon-on-Insulator Metal-Oxide-Semiconductor Field-Effect Transistor for Reliable Deep Sub-micron Devices

    NASA Astrophysics Data System (ADS)

    Elahipanah, Hossein; Orouji, Ali A.

    2009-11-01

    For first time, we report a novel deep sub-micron fully-depleted silicon-on-insulator metal-oxide-semiconductor field-effect-transistor (FD SOI MOSFET) where the channel layer consists of two sections with a step doping (SD) region in order to increase performance and reliability of the device. This new structure that called SD FD SOI structure (SDFD-SOI MOSFET), were used for reaching suitable threshold voltage upon device scaling and reliability improvement. We demonstrate that the electric field was modified in the channel and common peak near the source junction have been reduced in the SDFD-SOI structure. The device demonstrates large enhancements in performance areas such as current drive capability, output resistance, hot-carrier reliability and threshold voltage roll-off. It was found that the device performance is very much dependent upon the SD region parameters. Simulation results show that the proposed structure improved on/off current ratio, and saturated output characteristics compared with conventional SOI structure (C-SOI MOSFET). Also, it was shown that substrate current of SDFD-SOI MOSFET is much lower than the C-SOI MOSFET which presented the lower hot-carrier degradation in proposed MOSFET. Results show that the most short-channel problems in very large scale integrated circuits (VLSI) could be solved and the proposed SDFD-SOI MOSFETs can work very well in deep sub-micron and nanoscale regime.

  11. A review of the mechanical stressors efficiency applied to the ultra-thin body & buried oxide fully depleted silicon on insulator technology

    NASA Astrophysics Data System (ADS)

    Morin, Pierre; Maitrejean, Sylvain; Allibert, Frederic; Augendre, Emmanuel; Liu, Qing; Loubet, Nicolas; Grenouillet, Laurent; Pofelski, Alexandre; Chen, Kangguo; Khakifirooz, Ali; Wacquez, Romain; Reboh, Shay; Bonnevialle, Aurore; le Royer, Cyrille; Morand, Yves; Kanyandekwe, Joel; Chanemougamme, Daniel; Mignot, Yann; Escarabajal, Yann; Lherron, Benoit; Chafik, Fadoua; Pilorget, Sonia; Caubet, Pierre; Vinet, Maud; Clement, Laurent; Desalvo, Barbara; Doris, Bruce; Kleemeier, Walter

    2016-03-01

    This paper reviews the different stressor techniques used in microelectronics, in the scope of the Ultra-Thin Body & Buried Oxide Fully-Depleted Silicon On Insulator technology (UTBB FD-SOI). We compare the mechanical efficiency of the various stressors and present the impact of device dimensions (active area, gate length and pitch) on their efficiency. Our study emphasizes the high efficiency, for the FD-SOI technology, of the intrinsically strained channels, compared to the traditional embedded raised source/drain and contact-etch stop liner. With these techniques FD-SOI technology has already demonstrated channel stress higher than 1.5 GPa for n type transistor and -2.3 GPa for the p type devices and we envision channel stress values up to ±3 GPa for n and p transistor channel, respectively. This performance is partly due to the mechanical configuration of intrinsically strained channels, in parallel mode rather than in serial mode as for the previous generation of stressors, which makes them less sensitive to the scaling of the contacted gate pitch. We also highlight another key element the high mechanical stability of the UTBB technology, related to the limited channel thickness (around 6 nm) which enables achieving highly stressed channel without substantial adaptation of the integration flows.

  12. Disposition of Depleted Uranium Oxide

    SciTech Connect

    Crandall, J.L.

    2001-08-13

    This document summarizes environmental information which has been collected up to June 1983 at Savannah River Plant. Of particular interest is an updating of dose estimates from changes in methodology of calculation, lower cesium transport estimates from Steel Creek, and new sports fish consumption data for the Savannah River. The status of various permitting requirements are also discussed.

  13. NCX-4040, a nitric oxide-releasing aspirin, sensitizes drug-resistant human ovarian xenograft tumors to cisplatin by depletion of cellular thiols

    PubMed Central

    Bratasz, Anna; Selvendiran, Karuppaiyah; Wasowicz, Tomasz; Bobko, Andrey; Khramtsov, Valery V; Ignarro, Louis J; Kuppusamy, Periannan

    2008-01-01

    Background Ovarian carcinoma is the leading cause of mortality among gynecological cancers in the world. The high mortality rate is associated with lack of early diagnosis and development of drug resistance. The antitumor efficacy and mechanism of NCX-4040, a nitric oxide-releasing aspirin derivative, against ovarian cancer is studied. Methods NCX-4040, alone or in combination with cisplatin (cis-diamminedichloroplatinum, cDDP), was studied in cisplatin-sensitive (A2780 WT) and cisplatin-resistant (A2780 cDDP) cell lines as well as xenograft tumors grown in nude mice. Electron paramagnetic resonance (EPR) was used for measurements of nitric oxide and redox state. Immunoblotting analysis of A2780 cDDP tumor xenografts from mice was used for mechanistic studies. Results Cells treated with NCX-4040 (25 μM) showed a significant reduction of cell viability (A2780 WT, 34.9 ± 8.7%; A2780 cDDP, 41.7 ± 7.6%; p < 0.05). Further, NCX-4040 significantly enhanced the sensitivity of A2780 cDDP cells (cisplatin alone, 80.6 ± 11.8% versus NCX-4040+cisplatin, 26.4 ± 7.6%; p < 0.01) and xenograft tumors (cisplatin alone, 74.0 ± 4.4% versus NCX-4040+cisplatin, 56.4 ± 7.8%; p < 0.05), to cisplatin treatment. EPR imaging of tissue redox and thiol measurements showed a 5.5-fold reduction (p < 0.01) of glutathione in NCX-4040-treated A2780 cDDP tumors when compared to untreated controls. Immunoblotting analysis of A2780 cDDP tumor xenografts from mice treated with NCX-4040 and cisplatin revealed significant downregulation of pEGFR (Tyr845 and Tyr992) and pSTAT3 (Tyr705 and Ser727) expression. Conclusion The results suggested that NCX-4040 could resensitize drug-resistant ovarian cancer cells to cisplatin possibly by depletion of cellular thiols. Thus NCX-4040 appears to be a potential therapeutic agent for the treatment of human ovarian carcinoma and cisplatin-resistant malignancies. PMID:18302761

  14. The novel marker LTBP2 predicts all-cause and pulmonary death in patients with acute dyspnoea.

    PubMed

    Breidthardt, Tobias; Vanpoucke, Griet; Potocki, Mihael; Mosimann, Tamina; Ziller, Ronny; Thomas, Gregoire; Laroy, Wouter; Moerman, Piet; Socrates, Thenral; Drexler, Beatrice; Mebazaa, Alexandre; Kas, Koen; Mueller, Christian

    2012-11-01

    The risk stratification in patients presenting with acute dyspnoea remains a challenge. We therefore conducted a prospective, observational cohort study enrolling 292 patients presenting to the emergency department with acute dyspnoea. A proteomic approach for antibody-free targeted protein quantification based on high-end MS was used to measure LTBP2 [latent TGF (transforming growth factor)-binding protein 2] levels. Final diagnosis and death during follow-up were adjudicated blinded to LTBP2 levels. AHF (acute heart failure) was the final diagnosis in 54% of patients. In both AHF (P<0.001) and non-AHF (P=0.015) patients, LTBP2 levels at presentation were significantly higher in non-survivors compared with survivors with differences on median levels being 2.2- and 1.5-fold respectively. When assessing the cause of death, LTBP2 levels were significantly higher in patients dying from pulmonary causes (P=0.0005). Overall, LTBP2 powerfully predicted early pulmonary death {AUC (area under the curve), 0.95 [95% CI (confidence interval), 0.91-0.98]}. In ROC (receiver operating characteristic) curve analyses for the prediction of 1-year mortality LTBP2 achieved an AUC of 0.77 (95% CI, 0.71-0.84); comparable with the predictive potential of NT-proBNP [N-terminal pro-B-type natriuruetic peptide; 0.77 (95% CI, 0.72-0.82)]. Importantly, the predictive potential of LTBP2 persisted in patients with AHF as the cause of dypnea (AUC 0.78) and was independent of renal dysfunction (AUC 0.77). In a multivariate Cox regression analysis, LTBP2 was the strongest independent predictor of death [HR (hazard ratio), 3.76 (95% CI, 2.13-6.64); P<0.0001]. In conclusion, plasma levels of LTBP2 present a novel and powerful predictor of all-cause mortality, and particularly pulmonary death. Cause-specific prediction of death would enable targeted prevention, e.g. with pre-emptive antibiotic therapy.

  15. Obese sedentary patients with dyspnoea on exertion who are at low risk for coronary artery disease by clinical criteria have a very low prevalence of coronary artery disease.

    PubMed

    Bruckel, J T; Larsen, G; Benson, M R

    2014-06-01

    Dyspnoea, a much less specific symptom of ischaemia than chest discomfort, is common among obese patients. Patients with dyspnoea often undergo stress testing as part of their evaluation. We sought to examine the yield of stress testing in non-elderly, obese, sedentary patients with dyspnoea on exertion (DOE) as a chief complaint.We reviewed stress echocardiograms carried out on 203 patients in a stress testing laboratory at a major tertiary care centre. Of these, 81 (40%) fell into a group that was at low risk for coronary artery disease (CAD) by clinical criteria. Ischaemia was detected in two patients in the low-risk group (2.5%), and these results were likely false positives. In the higher risk group, 9.0% of functional tests showed ischaemia; after further testing, 2.5% of the higher risk patients were found to have obstructive coronary lesions. Clinical follow-up was performed for a mean of 815 days. New obstructive coronary disease was detected in 1.6% of all patients, and these patients were from the higher risk group. In obese sedentary patients with DOE but otherwise at low risk of coronary disease stress testing is of very low yield. DOE is generally not an anginal equivalent in this patient population.

  16. Depleted Uranium in Repositories

    SciTech Connect

    Haire, M.J.; Croff, A.G.

    1997-12-31

    For uranium to be useful in most fission nuclear reactors, it must be enriched (i.e. the concentration of the fissile isotope 235U must be increased). Therefore, depleted uranium (DU)-uranium which has less than naturally occurring concentrations of 235U-is a co-product of the enrichment process. Four to six tons of DU exist for every ton of fresh light water reactor fuel. There were 407,006 MgU 407,000 metric tons (t) of DU stored on U.S. Department of Energy (DOE) sites as of July 1993. If this DU were to be declared surplus, converted to a stable oxide form, and emplaced in a near surface disposal facility, the costs are estimated to be several billion dollars. However, the U.S. Nuclear Regulatory Commission has stated that near surface disposal of large quantities of DU tails is not appropriate. Thus, there is the possibility that disposition via disposal will be in a deep geological repository. One alternative that may significantly reduce the cost of DU disposition is to use it beneficially. In fact, DOE has begun the Beneficial Uses of DU Project to identify large scale uses of DU and to encourage its reuse. Several beneficial uses, many of which involve applications in the repository per se or in managing the wastes to go into the repository, are discussed in this report.

  17. Possible ozone depletions following nuclear explosions

    NASA Technical Reports Server (NTRS)

    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.-

  18. Water Depletion Threatens Agriculture

    NASA Astrophysics Data System (ADS)

    Brauman, K. A.; Richter, B. D.; Postel, S.; Floerke, M.; Malsy, M.

    2014-12-01

    Irrigated agriculture is the human activity that has by far the largest impact on water, constituting 85% of global water consumption and 67% of global water withdrawals. Much of this water use occurs in places where water depletion, the ratio of water consumption to water availability, exceeds 75% for at least one month of the year. Although only 17% of global watershed area experiences depletion at this level or more, nearly 30% of total cropland and 60% of irrigated cropland are found in these depleted watersheds. Staple crops are particularly at risk, with 75% of global irrigated wheat production and 65% of irrigated maize production found in watersheds that are at least seasonally depleted. Of importance to textile production, 75% of cotton production occurs in the same watersheds. For crop production in depleted watersheds, we find that one half to two-thirds of production occurs in watersheds that have not just seasonal but annual water shortages, suggesting that re-distributing water supply over the course of the year cannot be an effective solution to shortage. We explore the degree to which irrigated production in depleted watersheds reflects limitations in supply, a byproduct of the need for irrigation in perennially or seasonally dry landscapes, and identify heavy irrigation consumption that leads to watershed depletion in more humid climates. For watersheds that are not depleted, we evaluate the potential impact of an increase in irrigated production. Finally, we evaluate the benefits of irrigated agriculture in depleted and non-depleted watersheds, quantifying the fraction of irrigated production going to food production, animal feed, and biofuels.

  19. Halo Star Lithium Depletion

    SciTech Connect

    Pinsonneault, M. H.; Walker, T. P.; Steigman, G.; Narayanan, Vijay K.

    1999-12-10

    The depletion of lithium during the pre-main-sequence and main-sequence phases of stellar evolution plays a crucial role in the comparison of the predictions of big bang nucleosynthesis with the abundances observed in halo stars. Previous work has indicated a wide range of possible depletion factors, ranging from minimal in standard (nonrotating) stellar models to as much as an order of magnitude in models that include rotational mixing. Recent progress in the study of the angular momentum evolution of low-mass stars permits the construction of theoretical models capable of reproducing the angular momentum evolution of low-mass open cluster stars. The distribution of initial angular momenta can be inferred from stellar rotation data in young open clusters. In this paper we report on the application of these models to the study of lithium depletion in main-sequence halo stars. A range of initial angular momenta produces a range of lithium depletion factors on the main sequence. Using the distribution of initial conditions inferred from young open clusters leads to a well-defined halo lithium plateau with modest scatter and a small population of outliers. The mass-dependent angular momentum loss law inferred from open cluster studies produces a nearly flat plateau, unlike previous models that exhibited a downward curvature for hotter temperatures in the 7Li-Teff plane. The overall depletion factor for the plateau stars is sensitive primarily to the solar initial angular momentum used in the calibration for the mixing diffusion coefficients. Uncertainties remain in the treatment of the internal angular momentum transport in the models, and the potential impact of these uncertainties on our results is discussed. The 6Li/7Li depletion ratio is also examined. We find that the dispersion in the plateau and the 6Li/7Li depletion ratio scale with the absolute 7Li depletion in the plateau, and we use observational data to set bounds on the 7Li depletion in main-sequence halo

  20. Lake acidification and oxygen depletion may synergistically enhance nitrous oxide (N2O) production by nitrifier denitrification in a subalpine lake

    NASA Astrophysics Data System (ADS)

    Frame, C. H.; Goepfert, T. J.; Rollog, M.; Lehmann, M. F.

    2013-12-01

    Ammonia-oxidizing microorganisms are an important source of the greenhouse gas nitrous oxide (N2O). They produce N2O through two mechanisms: by the decomposition of an intermediate in the ammonia (NH3) oxidation reaction, and by nitrifier denitrification, which is the enzymatic reduction of nitrite (NO2-). We investigated the impact of water pH and oxygen (O2) concentrations on rates of N2O production by these two mechanisms in the water column of Lake Lugano, a subalpine lake between Switzerland and Italy. Acidification of natural waters is known to reduce the rate of ammonia oxidation by forcing the equilibrium NH4+ ←→ NH3 + H+ away from NH3, the form that is preferentially taken up by ammonia oxidizers. In turn, this reduces the rate of N2O production by decomposition of the reaction intermediate during ammonia oxidation. However, using 15NH4+ and 15NO2- tracer additions during lake water incubations, we showed that reducing the pH from in situ values of 7.5 to 8 down to 6 to 7 actually increased the rate of N2O production by nitrifier denitrification. Hypoxia is thought to enhance N2O production by nitrifier denitrification. We did not observe nitrifier denitrification in incubations that were fully oxic (partial pressure of O2 = 20.9%) or had reduced O2 (partial pressure = 12%). However, when the incubation pH was lowered and the O2 reduced to 12%, N2O production by nitrifier denitrification was much greater than it was in incubations where only the pH was reduced or only the O2 concentration was reduced. Water for these experiments was drawn from depths just below the epilimnion of the monomictic south basin of Lugano, an environment whose pH, O2, and nutrient concentrations fluctuate throughout the water column on a seasonal basis and change in the shallower depths on a daily basis. We discuss the implications of these changes for the flux of shallow N2O into the atmosphere and a possible mechanism that explains the synergistic influence of O2 and pH on

  1. Predictive Value of Admission N-Terminal Pro-B-Type Natriuretic Peptide and Renal Function in Older People Hospitalized for Dyspnoea

    PubMed Central

    De Giorgi, Alfredo; Pala, Marco; Zuliani, Giovanni

    2013-01-01

    Background. We investigated the relationship between NT-pro-BNP, glomerular filtration rate (GFR), and all-cause mortality rates in a cohort of older people discharged from an internal medicine unit after admission for dyspnoea. Patients and Methods. NT-pro-BNP was evaluated in serum samples of 134 patients aged 80 ± 6 years who presented to a single academic centre with worsening dyspnoea. History data and anthropometric, clinical, and biochemical parameters including GFR were collected at the time of admission. 119 out of 134 were discharged alive from hospital and were included in the follow-up of 779 ± 370 days. Results. 35 out of 119 subjects died after a follow-up of 266 ± 251 days. Cox proportional hazards model showed that GFR and Ln (NT-pro-BNP) were predictors for all-cause mortality with estimated hazard ratios of 0.969 (95% confidence interval: 0.950–0.988; P = 0.001) and 2.360 (95% confidence interval: 1.208–4.610; P = 0.012), respectively. Patients characterized by high NT-pro-BNP levels and GFR ≥ 60 mL/min/1.73 m2 showed a dramatic reduction in survival duration compared with the groups with different combinations of the two variables (P = 0.008). Conclusions. In the elderly, NT-pro-BNP and GFR are predictors of all-cause mortality after admission because of dyspnoea. Since the fact that subjects with high NT-pro-BNP and GFR ≥ 60 mL/min/1.73 m2 exhibited a reduced survival, high admission NT-pro-BNP suggests future negative outcome. PMID:24324290

  2. Battery depletion monitor

    SciTech Connect

    Lee, Y.S.

    1982-01-26

    A cmos inverter is used to compare pacemaker battery voltage to a referenced voltage. When the reference voltage exceeds the measured battery voltage, the inverter changes state to indicate battery depletion.

  3. Exogenous NO depletes Cd-induced toxicity by eliminating oxidative damage, re-establishing ATPase activity, and maintaining stress-related hormone equilibrium in white clover plants.

    PubMed

    Liu, S L; Yang, R J; Pan, Y Z; Wang, M H; Zhao, Y; Wu, M X; Hu, J; Zhang, L L; Ma, M D

    2015-11-01

    Various nitric oxide (NO) regulators [including the NO donor sodium nitroprusside (SNP), the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), the NO-synthase inhibitor N (G)-nitro-L-Arg-methyl ester (L-NAME), and the SNP analogues sodium nitrite/nitrate and sodium ferrocyanide] were investigated to elucidate the role of NO in white clover (Trifolium repens L.) plants after long-term (5 days) exposure to cadmium (Cd). A dose of 100 μM Cd stress significantly restrained plant growth and decreased the concentrations of chlorophyll and NO in vivo, whereas it disrupted the balance of stress-related hormones and enhanced the accumulation of Cd, thereby inducing reactive oxygen species (ROS) burst. However, the inhibition of plant growth was relieved by 50 μM SNP through its stimulation of ROS-scavenging compounds (ascorbic acid, ascorbate peroxidase, catalase, glutathione reductase, non-protein thiol, superoxide dismutase, and total glutathione), regulation of H(+)-ATPase activity of proton pumps, and increasing jasmonic acid and proline but decreasing ethylene in plant tissues. Even so, the alleviating effect of SNP on plant growth was counteracted by cPTIO and L-NAME and was not observed with SNP analogues, suggesting that the protective roles of SNP are related to the induction of NO. These results suggest that NO may improve the Cd tolerance of white clover plants by eliminating oxidative damage, re-establishing ATPase activity, and maintaining hormone equilibrium. Improving our understanding of the role of NO in white clover plants is key to expanding the plantations to various regions and the recovery of pasture species in the future.

  4. Depleted uranium: A DOE management guide

    SciTech Connect

    1995-10-01

    The U.S. Department of Energy (DOE) has a management challenge and financial liability 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. The annual storage and maintenance cost is approximately $10 million. This report summarizes several studies undertaken by the DOE Office of Technology Development (OTD) to evaluate options for long-term depleted uranium management. Based on studies conducted to date, the most likely use of the depleted uranium is for shielding of spent nuclear fuel (SNF) or vitrified high-level waste (HLW) containers. The alternative to finding a use for the depleted uranium is disposal as a radioactive waste. Estimated disposal costs, utilizing existing technologies, range between $3.8 and $11.3 billion, depending on factors such as applicability of the Resource Conservation and Recovery Act (RCRA) and the location of the disposal site. The cost of recycling the depleted uranium in a concrete based shielding in SNF/HLW containers, although substantial, is comparable to or less than the cost of disposal. Consequently, the case can be made that if DOE invests in developing depleted uranium shielded containers instead of disposal, a long-term solution to the UF{sub 6} problem is attained at comparable or lower cost than disposal as a waste. Two concepts for depleted uranium storage casks were considered in these studies. The first is based on standard fabrication concepts previously developed for depleted uranium metal. The second converts the UF{sub 6} to an oxide aggregate that is used in concrete to make dry storage casks.

  5. Cholesterol depletion induces autophagy

    SciTech Connect

    Cheng, Jinglei; Ohsaki, Yuki; Tauchi-Sato, Kumi; Fujita, Akikazu; Fujimoto, Toyoshi . E-mail: tfujimot@med.nagoya-u.ac.jp

    2006-12-08

    Autophagy is a mechanism to digest cells' own components, and its importance in many physiological and pathological processes is being recognized. But the molecular mechanism that regulates autophagy is not understood in detail. In the present study, we found that cholesterol depletion induces macroautophagy. The cellular cholesterol in human fibroblasts was depleted either acutely using 5 mM methyl-{beta}-cyclodextrin or 10-20 {mu}g/ml nystatin for 1 h, or metabolically by 20 {mu}M mevastatin and 200 {mu}M mevalonolactone along with 10% lipoprotein-deficient serum for 2-3 days. By any of these protocols, marked increase of LC3-II was detected by immunoblotting and by immunofluorescence microscopy, and the increase was more extensive than that caused by amino acid starvation, i.e., incubation in Hanks' solution for several hours. The induction of autophagic vacuoles by cholesterol depletion was also observed in other cell types, and the LC3-positive membranes were often seen as long tubules, >50 {mu}m in length. The increase of LC3-II by methyl-{beta}-cyclodextrin was suppressed by phosphatidylinositol 3-kinase inhibitors and was accompanied by dephosphorylation of mammalian target of rapamycin. By electron microscopy, autophagic vacuoles induced by cholesterol depletion were indistinguishable from those seen after amino acid starvation. These results demonstrate that a decrease in cholesterol activates autophagy by a phosphatidylinositol 3-kinase-dependent mechanism.

  6. Charge depletion meter

    NASA Astrophysics Data System (ADS)

    Schneider, J. F.

    1984-11-01

    This invention relates to a charge depletion meter apparatus having a current to frequency converter to sense and convert the current drain of a battery source to a digital signal which is divided and then accumulated in a counter. An LCD display unit displays the accumulated charge which is received from the counter.

  7. Treatment of green tea polyphenols in hydrophilic cream prevents UVB-induced oxidation of lipids and proteins, depletion of antioxidant enzymes and phosphorylation of MAPK proteins in SKH-1 hairless mouse skin.

    PubMed

    Vayalil, Praveen K; Elmets, Craig A; Katiyar, Santosh K

    2003-05-01

    The use of botanical supplements has received immense interest in recent years to protect human skin from adverse biological effects of solar ultraviolet (UV) radiation. The polyphenols from green tea are one of them and have been shown to prevent photocarcinogenesis in animal models but their mechanism of photoprotection is not well understood. To determine the mechanism of photoprotection in in vivo mouse model, topical treatment of polyphenols from green tea (GTP) or its most chemopreventive constituent (-)-epigallocatechin-3-gallate (EGCG) (1 mg/cm(2) skin area) in hydrophilic ointment USP before single (180 mJ/cm(2)) or multiple UVB exposures (180 mJ/cm(2), daily for 10 days) resulted in significant prevention of UVB-induced depletion of antioxidant enzymes such as glutathione peroxidase (78-100%, P < 0.005-0.001), catalase (51-92%, P < 0.001) and glutathione level (87-100%, P < 0.005). Treatment of EGCG or GTP also inhibited UVB-induced oxidative stress when measured in terms of lipid peroxidation (76-95%, P < 0.001), and protein oxidation (67-75%, P > 0.001). Further, to delineate the inhibition of UVB-induced oxidative stress with cell signaling pathways, treatment of EGCG to mouse skin resulted in marked inhibition of a single UVB irradiation-induced phosphorylation of ERK1/2 (16-95%), JNK (46-100%) and p38 (100%) proteins of MAPK family in a time-dependent manner. Identical photoprotective effects of EGCG or GTP were also observed against multiple UVB irradiation-induced phosphorylation of the proteins of MAPK family in vivo mouse skin. Photoprotective efficacy of GTP given in drinking water (d.w.) (0.2%, w/v) was also determined and compared with that of topical treatment of EGCG and GTP. Treatment of GTP in d.w. also significantly prevented single or multiple UVB irradiation-induced depletion of antioxidant enzymes (44-61%, P < 0.01-0.001), oxidative stress (33-71%, P < 0.01) and phosphorylation of ERK1/2, JNK and p38 proteins of MAPK family but the

  8. Effectiveness of γ-oryzanol in reducing neuromotor deficits, dopamine depletion and oxidative stress in a Drosophila melanogaster model of Parkinson's disease induced by rotenone.

    PubMed

    Araujo, Stífani Machado; de Paula, Mariane Trindade; Poetini, Marcia Rósula; Meichtry, Luana; Bortolotto, Vandreza Cardoso; Zarzecki, Micheli Stefani; Jesse, Cristiano Ricardo; Prigol, Marina

    2015-12-01

    The γ-orizanol present in rice bran oil contains a mix of steryl triterpenyl esters of ferulic acid, which is believed to be linked to its antioxidant potential. In this study we investigated the neuroprotective actions of γ-orizanol (ORY) against the toxicity induced by rotenone (ROT) in Drosophila melanogaster. The flies (both genders) aged between 1 and 5 days old were divided into four groups of 50 flies each: (1) control, (2) ORY 25 μM, (3) ROT 500 μM, (4) ORY 25 μM+ROT 500 μM. Flies were concomitantly exposed to a diet containing ROT and ORY for 7 days according to their respective groups. Survival and behavior analyses were carried out in vivo, and ex vivo analyses involved acetylcholinesterase activity (AChE), determination of dopaminergic levels, cellular viability and mitochondrial viability, activities of superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), reactive species levels (RS), lipid peroxidation (TBARS) and contents of total thiols and non-proteic thiols (NPSH). Our results show for the first time that ORY not only acts as an endogenous activator of the cellular antioxidant defenses, but it also ameliorates rotenone induced mortality, oxidative stress and mitochondrial dysfunction. Our salient findings regarded the restoration of cholinergic deficits, dopamine levels and improved motor function provided by ORY. These results demonstrate the neuroprotective potential of ORY and that this effect can be potentially due to its antioxidant action. In conclusion, the present results show that ORY is effective in reducing the ROT induced toxicity in D. melanogaster, which showed a neuroprotective action, possibly due to the presence of the antioxidant constituents such as the ferulic acid.

  9. Depleted uranium disposal options evaluation

    SciTech Connect

    Hertzler, T.J.; Nishimoto, D.D.; Otis, M.D.

    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.

  10. Type 2-depleted fungal laccase.

    PubMed Central

    Hanna, P M; McMillin, D R; Pasenkiewicz-Gierula, M; Antholine, W E; Reinhammar, B

    1988-01-01

    Although copper is quantitatively removed from fungal laccase (Polyporus versicolor) by extended dialysis against high concentrations of cyanide, we have been unable to reconstitute the protein by addition of Cu(I) ions. However, two new methods for reversibly removing the type 2 Cu centre have been developed. The visible absorption at 610 nm, which is attributable to type 1 Cu, is unaffected by the procedure, but the absorbance of the type 3 Cu at 330 nm is decreased by 60 +/- 10%. The decrease is due, at least in part, to partial reduction of the binuclear type 3 centre, although there may be some change in the molar absorptivity of the oxidized chromophore as well. The change in the c.d. spectrum that occurs at approx. 350 nm may be explained in the same way, but it may also reflect the loss of a signal due to the type 2 Cu. Upon removal of the type 2 Cu an absorbance increase appears at approx. 435 nm, and it is assigned to the semi-reduced form of the type 3 pair. In the e.p.r. spectrum of the type 2-depleted enzyme the type 1 Cu signal exhibits well-resolved ligand hyperfine splitting, which can be simulated on the basis of contributions from two N and two H nuclei (AH congruent to AN congruent to 25 MHz). The H atoms are assumed to be attached to the beta-carbon of the covalently bonded cysteine ligand. A signal from a semi-reduced form(s) of the type 3 site can also be resolved in the spectrum of the type 2-depleted enzyme, and on the basis of the second integral of the e.p.r. spectrum 40% of the type 3 pairs are believed to be in a partially reduced state. The semi-reduced type 3 site is remarkably stable and is not readily oxidized by H2O2 or IrCl6(2-) or reduced by Fe(CN)6(4-). Intramolecular electron transfer is apparently quite slow in at least some forms of the type 2-depleted enzyme, and this may explain why the activity is at best 5% of that of the native enzyme. Full activity returns when type 2 copper is restored. PMID:2845923

  11. Ghrelin protects against depleted uranium-induced apoptosis of MC3T3-E1 cells through oxidative stress-mediated p38-mitogen-activated protein kinase pathway.

    PubMed

    Hao, Yuhui; Liu, Cong; Huang, Jiawei; Gu, Ying; Li, Hong; Yang, Zhangyou; Liu, Jing; Wang, Weidong; Li, Rong

    2016-01-01

    Depleted uranium (DU) mainly accumulates in the bone over the long term. Osteoblast cells are responsible for the formation of bone, and they are sensitive to DU damage. However, studies investigating methods of reducing DU damage in osteoblasts are rarely reported. Ghrelin is a stomach hormone that stimulates growth hormones released from the hypothalamic-pituitary axis, and it is believed to play an important physiological role in bone metabolism. This study evaluates the impact of ghrelin on DU-induced apoptosis of the osteoblast MC3T3-E1 and investigates its underlying mechanisms. The results show that ghrelin relieved the intracellular oxidative stress induced by DU, eliminated reactive oxygen species (ROS) and reduced lipid peroxidation by increasing intracellular GSH levels; in addition, ghrelin effectively suppressed apoptosis, enhanced mitochondrial membrane potential, and inhibited cytochrome c release and caspase-3 activation after DU exposure. Moreover, ghrelin significantly reduced the expression of DU-induced phosphorylated p38-mitogen-activated protein kinase (MAPK). A specific inhibitor (SB203580) or specific siRNA of p38-MAPK could significantly suppress DU-induced apoptosis and related signals, whereas ROS production was not affected. In addition, ghrelin receptor inhibition could reduce the anti-apoptosis effect of ghrelin on DU and reverse the effect of ghrelin on intracellular ROS and p38-MAPK after DU exposure. These results suggest that ghrelin can suppress DU-induced apoptosis of MC3T3-E1 cells, reduce DU-induced oxidative stress by interacting with its receptor, and inhibit downstream p38-MAPK activation, thereby suppressing the mitochondrial-dependent apoptosis pathway.

  12. Low-power scan driver embedded with level shifter using depletion-mode amorphous indium-gallium-zinc-oxide thin-film transistors for high-resolution flat-panel displays

    NASA Astrophysics Data System (ADS)

    Lee, Chang-Hee; Kwon, Oh-Kyong

    2014-01-01

    A low-power scan driver embedded with a level shifter using depletion-mode amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) is proposed for high-resolution flat-panel displays (FPDs). In order to achieve low power consumption, the scan driver uses clock signals with a reduced voltage swing. Furthermore, the level shifter is implemented without using a diode-connected TFT. This scan driver is simulated at an output voltage swing of 30 V and an operating frequency (fop) of 153.6 kHz, which satisfy the driving conditions for 10-in. wide quadruple extended graphics array (WQXGA, 1600 × 2560) FPDs with a frame frequency of 60 Hz. The simulation results of the proposed scan driver demonstrate the successful operation even at a threshold voltage shift (ΔVth) of -2.0 V. The power consumption of the proposed scan driver per ten stages is 0.41 mW, which is 80.75% less than that reported in a previous work.

  13. Ozone depletion by hydrofluorocarbons

    NASA Astrophysics Data System (ADS)

    Hurwitz, Margaret M.; Fleming, Eric L.; Newman, Paul A.; Li, Feng; Mlawer, Eli; Cady-Pereira, Karen; Bailey, Roshelle

    2015-10-01

    Atmospheric concentrations of hydrofluorocarbons (HFCs) are projected to increase considerably in the coming decades. Chemistry climate model simulations forced by current projections show that HFCs will impact the global atmosphere increasingly through 2050. As strong radiative forcers, HFCs increase tropospheric and stratospheric temperatures, thereby enhancing ozone-destroying catalytic cycles and modifying the atmospheric circulation. These changes lead to a weak depletion of stratospheric ozone. Simulations with the NASA Goddard Space Flight Center 2-D model show that HFC-125 is the most important contributor to HFC-related atmospheric change in 2050; its effects are comparable to the combined impacts of HFC-23, HFC-32, HFC-134a, and HFC-143a. Incorporating the interactions between chemistry, radiation, and dynamics, ozone depletion potentials (ODPs) for HFCs range from 0.39 × 10-3 to 30.0 × 10-3, approximately 100 times larger than previous ODP estimates which were based solely on chemical effects.

  14. Cyanate causes depletion of ascorbate in organisms.

    PubMed

    Koshiishi, I; Mamura, Y; Imanari, T

    1997-10-20

    Ascorbate-dehydroascorbate redox cycle plays a key role in protecting organisms from an excess of oxidants. Recently, we found a novel reaction of dehydroascorbate with cyanate under the conditions of neutral pH and ordinary temperature. In this report, we demonstrated that through this irreversible reaction, cyanate causes the depletion of ascorbate in the matrix, where the ascorbate-dehydroascorbate redox cycle revolves. When the leaves of weed (Erigeron canadensis) were soaked in sodium cyanate solution generally used as a herbicide, the depletion of ascorbate as well as dehydroascorbate in them was observed, followed by the change in color from green to brown. These results suggest that a possible way of cyanate toxicity is to inflict oxidative stress on organisms.

  15. Tank depletion flow controller

    DOEpatents

    Georgeson, Melvin A.

    1976-10-26

    A flow control system includes two bubbler tubes installed at different levels within a tank containing such as radioactive liquid. As the tank is depleted, a differential pressure transmitter monitors pressure differences imparted by the two bubbler tubes at a remote, shielded location during uniform time intervals. At the end of each uniform interval, balance pots containing a dense liquid are valved together to equalize the pressures. The resulting sawtooth-shaped signal generated by the differential pressure transmitter is compared with a second sawtooth signal representing the desired flow rate during each time interval. Variations in the two signals are employed by a control instrument to regulate flow rate.

  16. Depletion of Serotonin and Selective Inhibition of 2B Receptor Suppressed Tumor Angiogenesis by Inhibiting Endothelial Nitric Oxide Synthase and Extracellular Signal-Regulated Kinase 1/2 Phosphorylation12

    PubMed Central

    Asada, Masanori; Ebihara, Satoru; Yamanda, Shinsuke; Niu, Kaijun; Okazaki, Tatsuma; Sora, Ichiro; Arai, Hiroyuki

    2009-01-01

    The effects of serotonin (5-HT) on tumor growth are inconsistent. We investigated whether a decreased level of 5-HT affected tumor growth using 5-HT transporter knockout (5-HTT-/-) mice, which showed 5-HT depletion. When cancer cells were injected subcutaneously into both 5-HTT-/- and 5-HTT+/+ mice, the tumor growth was markedly attenuated in 5-HTT-/- mice. Serotonin levels in the blood, forebrain, and tumors of 5-HTT-/- mice bearing tumors were significantly smaller than those of their 5-HTT+/+ littermates. However, 5-HT did not increase cancer cells' proliferation in vitro. When we applied 5-HTT inhibitors to the wild mice bearing tumors, they did not inhibit tumor growth. The endothelial nitric oxide synthase (eNOS) expressions in tumors were reduced in 5-HTT-/- mice compared with 5-HTT+/+ mice. Stimulations with 5-HT (1–50 µM) induced eNOS expressions in human umbilical vein endothelial cell (HUVEC) in a concentration-dependent manner. When we measured activations of multiple signaling pathways by using a high-throughput phosphospecific antibodies platform, 5-HT stimulated the extracellular signal-regulated kinase 1/2 (ERK1/2) in HUVEC. Moreover, we found that the physiological level of 5-HT induced phosphorylation of both ERK1/2 and eNOS in HUVEC. Human umbilical vein endothelial cell expressed both 5-HT2B and 5-HT2C receptors. SB204741, a specific 5-HT2B receptor inhibitor, blocked 5-HT-induced ERK1/2 and eNOS phosphorylations, whereas RS102221, a specific 5-HT2C receptor inhibitor, did not in HUVEC. SB204741 reduced microvessel density in tumors and inhibited the proliferation of HUVEC in vitro. These results suggest that regulation of 5-HT and 5-HT receptors, especially the 5-HT2B receptor, may serve as a therapeutic strategy in cancer therapy. PMID:19308295

  17. Ozone Depletion by Hydrofluorocarbons

    NASA Astrophysics Data System (ADS)

    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.

  18. Antarctic springtime depletion of atmospheric mercury.

    PubMed

    Ebinghaus, Ralf; Kock, Hans H; Temme, Christian; Einax, Jürgen W; Lowe, Astrid G; Richter, Andreas; Burrows, John P; Schroeder, William H

    2002-03-15

    Unlike other heavy metals that are inherently associated with atmospheric aerosols, mercury in ambient air exists predominantly in the gaseous elemental form. Because of its prolonged atmospheric residence time, elemental mercury vapor is distributed on a global scale. Recently, Canadian researchers have discovered that total gaseous mercury levels in the lower tropospheric boundary layer in the Canadian Arctic are often significantly depleted during the months after polar sunrise. A possible explanation may involve oxidation of elemental mercury, followed by adsorption and deposition of the oxidized form, leading to an increased input of atmospheric mercury into the Arctic ecosystem. Here we present the first continuous high-time-resolution measurements of total gaseous mercury in the Antarctic covering a 12-month period between January 2000 and January 2001 at the German Antarctic research station Neumayer (70 degrees 39' S, 8 degrees 15' W). We report that mercury depletion events also occur in the Antarctic after polar sunrise and compare our measurements with a data setfrom Alert, Nunavut, Canada. We also present indications that BrO radicals and ozone play a key role in the boundary-layer chemistry during springtime mercury depletion events in the Antarctic troposphere.

  19. Beneficial Uses of Depleted Uranium

    SciTech Connect

    Brown, C.; Croff, A.G.; Haire, M. J.

    1997-08-01

    Naturally occurring uranium contains 0.71 wt% {sup 235}U. In order for the uranium to be useful in most fission reactors, it must be enriched the concentration of the fissile isotope {sup 235}U must be increased. Depleted uranium (DU) is a co-product of the processing of natural uranium to produce enriched uranium, and DU has a {sup 235}U concentration of less than 0.71 wt%. In the United States, essentially all of the DU inventory is in the chemical form of uranium hexafluoride (UF{sub 6}) and is stored in large cylinders above ground. If this co-product material were to be declared surplus, converted to a stable oxide form, and disposed, the costs are estimated to be several billion dollars. Only small amounts of DU have at this time been beneficially reused. The U.S. Department of Energy (DOE) has begun the Beneficial Uses of DU Project to identify large-scale uses of DU and encourage its reuse for the primary purpose of potentially reducing the cost and expediting the disposition of the DU inventory. This paper discusses the inventory of DU and its rate of increase; DU disposition options; beneficial use options; a preliminary cost analysis; and major technical, institutional, and regulatory issues to be resolved.

  20. Depleted zinc: Properties, application, production.

    PubMed

    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.

  1. 12. VIEW OF DEPLETED URANIUM INGOT AND MOLDS. DEPLETED URANIUM ...

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

    12. VIEW OF DEPLETED URANIUM INGOT AND MOLDS. DEPLETED URANIUM CASTING OPERATIONS CEASED IN 1988. (11/14/57) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO

  2. Ego depletion impairs implicit learning.

    PubMed

    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.

  3. Stratospheric ozone depletion.

    PubMed

    Rowland, F Sherwood

    2006-05-29

    Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the chemical species HO, HO2, NO, NO2, Cl and ClO. The NOX and ClOX chains involve the emission at Earth's surface of stable molecules in very low concentration (N2O, CCl2F2, CCl3F, etc.) which wander in the atmosphere for as long as a century before absorbing ultraviolet radiation and decomposing to create NO and Cl in the middle of the stratospheric ozone layer. The growing emissions of synthetic chlorofluorocarbon molecules cause a significant diminution in the ozone content of the stratosphere, with the result that more solar ultraviolet-B radiation (290-320 nm wavelength) reaches the surface. This ozone loss occurs in the temperate zone latitudes in all seasons, and especially drastically since the early 1980s in the south polar springtime-the 'Antarctic ozone hole'. The chemical reactions causing this ozone depletion are primarily based on atomic Cl and ClO, the product of its reaction with ozone. The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules. Recovery of the stratosphere to the ozone conditions of the 1950s will occur slowly over the rest of the twenty-first century because of the long lifetime of the precursor molecules.

  4. Stratospheric ozone depletion

    PubMed Central

    Rowland, F. Sherwood

    2006-01-01

    Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the chemical species HO, HO2, NO, NO2, Cl and ClO. The NOX and ClOX chains involve the emission at Earth's surface of stable molecules in very low concentration (N2O, CCl2F2, CCl3F, etc.) which wander in the atmosphere for as long as a century before absorbing ultraviolet radiation and decomposing to create NO and Cl in the middle of the stratospheric ozone layer. The growing emissions of synthetic chlorofluorocarbon molecules cause a significant diminution in the ozone content of the stratosphere, with the result that more solar ultraviolet-B radiation (290–320 nm wavelength) reaches the surface. This ozone loss occurs in the temperate zone latitudes in all seasons, and especially drastically since the early 1980s in the south polar springtime—the ‘Antarctic ozone hole’. The chemical reactions causing this ozone depletion are primarily based on atomic Cl and ClO, the product of its reaction with ozone. The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules. Recovery of the stratosphere to the ozone conditions of the 1950s will occur slowly over the rest of the twenty-first century because of the long lifetime of the precursor molecules. PMID:16627294

  5. Stratospheric ozone depletion.

    PubMed

    Rowland, F Sherwood

    2006-05-29

    Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the chemical species HO, HO2, NO, NO2, Cl and ClO. The NOX and ClOX chains involve the emission at Earth's surface of stable molecules in very low concentration (N2O, CCl2F2, CCl3F, etc.) which wander in the atmosphere for as long as a century before absorbing ultraviolet radiation and decomposing to create NO and Cl in the middle of the stratospheric ozone layer. The growing emissions of synthetic chlorofluorocarbon molecules cause a significant diminution in the ozone content of the stratosphere, with the result that more solar ultraviolet-B radiation (290-320 nm wavelength) reaches the surface. This ozone loss occurs in the temperate zone latitudes in all seasons, and especially drastically since the early 1980s in the south polar springtime-the 'Antarctic ozone hole'. The chemical reactions causing this ozone depletion are primarily based on atomic Cl and ClO, the product of its reaction with ozone. The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules. Recovery of the stratosphere to the ozone conditions of the 1950s will occur slowly over the rest of the twenty-first century because of the long lifetime of the precursor molecules. PMID:16627294

  6. Capstone Depleted Uranium Aerosols: Generation and Characterization

    SciTech Connect

    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.

  7. Cross-sectional dopant profiling and depletion layer visualization of SiC power double diffused metal-oxide-semiconductor field effect transistor using super-higher-order nonlinear dielectric microscopy

    NASA Astrophysics Data System (ADS)

    Chinone, N.; Nakamura, T.; Cho, Y.

    2014-08-01

    The dopant distribution and depletion layer in a cross-section of a SiC double diffused MOSFET (DMOSFET) is visualized using super-higher-order scanning nonlinear dielectric microscopy (SHO-SNDM), which is a form of scanning probe microscopy. Analysis of the data acquired by SHO-SNDM clarifies the dopant distribution in great detail, which is otherwise difficult to detect using conventional scanning capacitance microscopy or scanning microwave microscopy. Moreover, the newly developed SHO-SNDM method enables us to distinguish the n-type, p-type, and depletion layer regions very clearly, and they are found to be consistent with the general DMOSFET structure.

  8. Testing fully depleted CCD

    NASA Astrophysics Data System (ADS)

    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.

  9. Origin of Enthalpic Depletion Forces.

    PubMed

    Sapir, Liel; Harries, Daniel

    2014-04-01

    Solutes excluded from macromolecules or colloids are known to drive depletion attractions. The established Asakura-Oosawa model, as well as subsequent theories aimed at explaining the effects of macromolecular crowding, attribute depletion forces to diminished hard-core excluded volume upon compaction, and hence predict depletion forces dominated by entropy. However, recent experiments measuring the effect of preferentially excluded solutes on protein folding and macromolecular association find these forces can also be enthalpic. We use simulations of macromolecular association in explicit binary cosolute-solvent mixtures, with solvent and cosolute intermolecular interactions that go beyond hard-cores, to show that not all cosolutes conform to the established entropically dominated model. We further demonstrate how the enthalpically dominated depletion forces that we find can be well described within an Asakura-Oosawa like model provided that the hard-core macromolecule-cosolute potential of mean force is augmented by a "soft" step-like repulsion.

  10. Ego depletion impairs implicit learning.

    PubMed

    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. PMID:25275517

  11. Halocarbon ozone depletion and global warming potentials

    NASA Technical Reports Server (NTRS)

    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).

  12. Alpha-lipoic acid and N-acetylcysteine protects intensive swimming exercise-mediated germ-cell depletion, pro-oxidant generation, and alteration of steroidogenesis in rat testis.

    PubMed

    Jana, Kuladip; Dutta, Ananya; Chakraborty, Pratip; Manna, Indranil; Firdaus, Syed Benazir; Bandyopadhyay, Debasish; Chattopadhyay, Ratna; Chakravarty, Baidyanath

    2014-09-01

    Prolonged and strenuous exercise has been proposed as a possible source of male-factor infertility. Forced intensive swimming has also been identified as one source of a dysfunctional male reproduction system. The present study evaluated the possible protective role of α-lipoic acid and N-acetylcysteine (NAC) on intensive swimming-induced germ-cell depletion in adult male rats. Forced exhaustive swimming of 1 hr/day, 6 days/week for 8 consecutive weeks resulted in a significant (P < 0.05) reduction in epididymal sperm; testicular androgenic enzyme activities; and plasma and intra-testicular testosterone; and produced different types of germ cells in the seminiferous epithelium cycle. Conversely, plasma corticosterone levels and sperm-head abnormalities increased. Western-blot analysis showed a considerable decrease in testicular StAR protein expression whereas reverse-transcriptase PCR analysis showed no significant change in cytochrome P450scc (Cyp11a1) gene expression. Significant (P < 0.05) elevation in testicular reactive oxygen species (ROS), lipid peroxidation, protein carbonyl content versus reduction in glucose-6-phosphate dehydrogenase, glutathione peroxidase, glutathione S-transferase, and caspase-3 activities along with a depletion in the glutathione pool, mitochondrial membrane potential (▵ψm ), and intracellular ATP generation. A considerable level of DNA damage in testicular spermatogenic cells were also noted following forced extensive swimming. Alpha-lipoic acid and NAC supplementation prevented the swimming-induced testicular spermatogenic and steroidogenic disorders by lowering ROS generation. We therefore conclude that intensive forced swimming causes germ-cell depletion through the generation of ROS and depletion of steroidogenesis in the testis, which can be protected by the co-administration of α-lipoic acid and NAC. PMID:25104294

  13. Depleting depletion: Polymer swelling in poor solvent mixtures

    NASA Astrophysics Data System (ADS)

    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.

  14. Antarctic winter mercury and ozone depletion events over sea ice

    NASA Astrophysics Data System (ADS)

    Nerentorp Mastromonaco, M.; Gårdfeldt, K.; Jourdain, B.; Abrahamsson, K.; Granfors, A.; Ahnoff, M.; Dommergue, A.; Méjean, G.; Jacobi, H.-W.

    2016-03-01

    During atmospheric mercury and ozone depletion events in the springtime in polar regions gaseous elemental mercury and ozone undergo rapid declines. Mercury is quickly transformed into oxidation products, which are subsequently removed by deposition. Here we show that such events also occur during Antarctic winter over sea ice areas, leading to additional deposition of mercury. Over four months in the Weddell Sea we measured gaseous elemental, oxidized, and particulate-bound mercury, as well as ozone in the troposphere and total and elemental mercury concentrations in snow, demonstrating a series of depletion and deposition events between July and September. The winter depletions in July were characterized by stronger correlations between mercury and ozone and larger formation of particulate-bound mercury in air compared to later spring events. It appears that light at large solar zenith angles is sufficient to initiate the photolytic formation of halogen radicals. We also propose a dark mechanism that could explain observed events in air masses coming from dark regions. Br2 that could be the main actor in dark conditions was possibly formed in high concentrations in the marine boundary layer in the dark. These high concentrations may also have caused the formation of high concentrations of CHBr3 and CH2I2 in the top layers of the Antarctic sea ice observed during winter. These new findings show that the extent of depletion events is larger than previously believed and that winter depletions result in additional deposition of mercury that could be transferred to marine and terrestrial ecosystems.

  15. Fully depleted back illuminated CCD

    DOEpatents

    Holland, Stephen Edward

    2001-01-01

    A backside illuminated charge coupled device (CCD) is formed of a relatively thick high resistivity photon sensitive silicon substrate, with frontside electronic circuitry, and an optically transparent backside ohmic contact for applying a backside voltage which is at least sufficient to substantially fully deplete the substrate. A greater bias voltage which overdepletes the substrate may also be applied. One way of applying the bias voltage to the substrate is by physically connecting the voltage source to the ohmic contact. An alternate way of applying the bias voltage to the substrate is to physically connect the voltage source to the frontside of the substrate, at a point outside the depletion region. Thus both frontside and backside contacts can be used for backside biasing to fully deplete the substrate. Also, high resistivity gaps around the CCD channels and electrically floating channel stop regions can be provided in the CCD array around the CCD channels. The CCD array forms an imaging sensor useful in astronomy.

  16. [Measuring patient satisfaction in an emergency unit of a Swiss university hospital: occurrence of anxiety, insecurity, worry, pain, dyspnoea, nausea, thirst and hunger, and their correlation with patient satisfaction (part 2)].

    PubMed

    Müller-Staub, Maria; Meer, Ruth; Briner, Gabi; Probst, Marie-Therese; Needham, Ian

    2008-06-01

    This article reports the second part of a comprehensive study examining patient satisfaction with nursing care in ambulatory patients of a Swiss emergency department. A descriptive cross-sectional study examined patient satisfaction, using a revised version of the questionnaire in a convenience sample of 114 patients. The occurrence and intensity of anxiety, insecurity, worry, pain, dyspnoea, nausea, thirst and hunger, and their correlation with patient satisfaction were analyzed. The patients also reported if effective nursing interventions were carried out. Patients suffered from the following states or symptoms: Pain (70%), thirst (45%), insecurity (44%), anxiety (38%), hunger (25%), and nausea (12%). Despite the occurrence of these states or symptoms, not all patients reported receiving effective nursing interventions. Dyspnoea and pain were detected well by nurses and patients received effective nursing interventions. Anxiety, insecurity, nausea, thirst and hunger were not detected well by nurses; and patients often evaluated the nursing interventions they received as ineffective. These results were analyzed and compared with the findings measured by the instrument "Patient satisfaction with nursing care" applying correlations and ANOVA. Patients who suffered from the states or symptoms described above and reported receiving ineffective nursing interventions showed significantly lower patient satisfaction scores than patients not suffering from these states or symptoms. Statistically significant correlations were found between worry, pain, anxiety and patient satisfaction. The results of both studies (part 1+2) (Müller-Staub, Meer, Briner, Probst & Needham, 2008) are discussed, conclusions drawn and implications for practice and research presented.

  17. Thermophoretic depletion follows Boltzmann distribution.

    PubMed

    Duhr, Stefan; Braun, Dieter

    2006-04-28

    Thermophoresis, also termed thermal diffusion or the Soret effect, moves particles along temperature gradients. For particles in liquids, the effect lacks a theoretical explanation. We present experimental results at moderate thermal gradients: (i) Thermophoretic depletion of 200 nm polystyrene spheres in water follows an exponential distribution over 2 orders of magnitude in concentration; (ii) Soret coefficients scale linearly with the sphere's surface area. Based on the experiments, it is argued that local thermodynamic equilibrium is a good starting point to describe thermophoresis.

  18. Ozone depletion, paradigms, and politics

    SciTech Connect

    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.

  19. Ozone Depletion from Nearby Supernovae

    NASA Technical Reports Server (NTRS)

    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.

  20. Partial substitution of Mo{sup 6+} by S{sup 6+} in the fast oxide ion conductor La{sub 2}Mo{sub 2}O{sub 9}: Synthesis, structure and sulfur depletion

    SciTech Connect

    Mhadhbi, Noureddine; Corbel, Gwenaeel; Lacorre, Philippe; Bulou, Alain

    2012-06-15

    Powder-solid state reaction route using La{sub 2}(SO{sub 4}){sub 3} as sulfur source was used to prepare compositions of the solid solution La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9}. Single phases were only obtained in the substitution range extending up to y=0.8 (40 mol% S) at the annealing temperature of 850 Degree-Sign C with regard to the limit of stability of the lanthanum sulphate reactant. Within the synthesis conditions, a stabilization of the high temperature {beta}-form is observed from and above y=0.1 (5 mol% S). Temperature-controlled X-ray diffraction and thermogravimetric analyses have shown that La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9} raw powders undergo thermal decompositions in two steps. Heating above 900 Degree-Sign C, a sulfur depletion to the benefit of molybdenum in La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9} raw powders leads to the formation of La{sub 2}SO{sub 6}. At higher temperature, the exsolved La{sub 2}SO{sub 6} phase then decomposes into La{sub 2}O{sub 3}, which in turn reacts with the sulfur-depleted La{sub 2}Mo{sub 2}O{sub 9} phase to form La{sub 2}MoO{sub 6}. The present study also reveals that depending on the substitution rate y, the sulfur depletion can be induced by ball-milling of raw powders. Along the La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9} series, the isovalent substitution of molybdenum by sulfur tends to restrict in magnitude, or even to suppress above 400 Degree-Sign C, the distortive thermal expansion of the cubic {beta}-type structure, thus strongly decreasing the conductance at high temperature. - Graphical abstract: La{sub 2}O{sub 3}-MoO{sub 3}-'SO{sub 3}' ternary phase diagram showing the exsolution path at low temperature (white arrows) and the total decomposition path at high temperature (black arrows) of {beta}-La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9} raw powders. Highlights: Black-Right-Pointing-Pointer Isovalent substitution of molybdenum by sulfur in La{sub 2}Mo{sub 2}O{sub 9} up to 40 mol%. Black

  1. Issues in Stratospheric Ozone Depletion.

    NASA Astrophysics Data System (ADS)

    Lloyd, Steven Andrew

    Following the announcement of the discovery of the Antarctic ozone hole in 1985 there have arisen a multitude of questions pertaining to the nature and consequences of polar ozone depletion. This thesis addresses several of these specific questions, using both computer models of chemical kinetics and the Earth's radiation field as well as laboratory kinetic experiments. A coupled chemical kinetic-radiative numerical model was developed to assist in the analysis of in situ field measurements of several radical and neutral species in the polar and mid-latitude lower stratosphere. Modeling was used in the analysis of enhanced polar ClO, mid-latitude diurnal variation of ClO, and simultaneous measurements of OH, HO_2, H_2 O and O_3. Most importantly, such modeling was instrumental in establishing the link between the observed ClO and BrO concentrations in the Antarctic polar vortex and the observed rate of ozone depletion. The principal medical concern of stratospheric ozone depletion is that ozone loss will lead to the enhancement of ground-level UV-B radiation. Global ozone climatology (40^circS to 50^ circN latitude) was incorporated into a radiation field model to calculate the biologically accumulated dosage (BAD) of UV-B radiation, integrated over days, months, and years. The slope of the annual BAD as a function of latitude was found to correspond to epidemiological data for non-melanoma skin cancers for 30^circ -50^circN. Various ozone loss scenarios were investigated. It was found that a small ozone loss in the tropics can provide as much additional biologically effective UV-B as a much larger ozone loss at higher latitudes. Also, for ozone depletions of > 5%, the BAD of UV-B increases exponentially with decreasing ozone levels. An important key player in determining whether polar ozone depletion can propagate into the populated mid-latitudes is chlorine nitrate, ClONO_2 . As yet this molecule is only indirectly accounted for in computer models and field

  2. The production of 34S-depleted sulfide during bacterial disproportionation of elemental sulfur.

    PubMed

    Canfield, D E; Thamdrup, B

    1994-12-23

    Bacteria that disproportionate elemental sulfur fractionate sulfur isotopes such that sulfate is enriched in sulfur-34 by 12.6 to 15.3 per mil and sulfide is depleted in sulfur-34 by 7.3 to 8.6 per mil. Through a repeated cycle of sulfide oxidation to S0 and subsequent disproportionation, these bacteria can deplete sedimentary sulfides in sulfur-34. A prediction, borne out by observation, is that more extensive sulfide oxidation will lead to sulfides that are more depleted in sulfur-34. Thus, the oxidative part of the sulfur cycle creates circumstances by which sulfides become more depleted in sulfur-34 than would be possible with sulfate-reducing bacteria alone.

  3. The Production of 34S-Depleted Sulfide During Bacterial Disproportionation of Elemental Sulfur

    NASA Astrophysics Data System (ADS)

    Canfield, Donald E.; Thamdrup, Bo

    1994-12-01

    Bacteria that disproportionate elemental sulfur fractionate sulfur isotopes such that sulfate is enriched in sulfur-34 by 12.6 to 15.3 per mil and sulfide is depleted in sulfur-34 by 7.3 to 8.6 per mil. Through a repeated cycle of sulfide oxidation to S^0 and subsequent disproportionation, these bacteria can deplete sedimentary sulfides in sulfur-34. A prediction, borne out by observation, is that more extensive sulfide oxidation will lead to sulfides that are more depleted in sulfur-34. Thus, the oxidative part of the sulfur cycle creates circumstances by which sulfides become more depleted in sulfur-34 than would be possible with sulfate-reducing bacteria alone.

  4. The production of 34S-depleted sulfide during bacterial disproportionation of elemental sulfur

    NASA Technical Reports Server (NTRS)

    Canfield, D. E.; Thamdrup, B.

    1994-01-01

    Bacteria that disproportionate elemental sulfur fractionate sulfur isotopes such that sulfate is enriched in sulfur-34 by 12.6 to 15.3 per mil and sulfide is depleted in sulfur-34 by 7.3 to 8.6 per mil. Through a repeated cycle of sulfide oxidation to S0 and subsequent disproportionation, these bacteria can deplete sedimentary sulfides in sulfur-34. A prediction, borne out by observation, is that more extensive sulfide oxidation will lead to sulfides that are more depleted in sulfur-34. Thus, the oxidative part of the sulfur cycle creates circumstances by which sulfides become more depleted in sulfur-34 than would be possible with sulfate-reducing bacteria alone.

  5. Mercury depletion events over Antarctic and Arctic oceans

    NASA Astrophysics Data System (ADS)

    Nerentorp Mastromonaco, M. G.; Gardfeldt, K.; Wangberg, I.; Jourdain, B.; Dommergue, A.; Kuronen, P.; Pirrone, N.; Jacobi, H.

    2013-12-01

    Mercury is a global pollutant and in its elemental form it is spread by air to remote areas far away from point sources. In Antarctic and Arctic regions the airborne mercury may be oxidized, followed by deposition of the metal on land and sea surfaces. It is previously known that during early spring in these regions, processes involving halogen radical photochemistry induce an oxidation of gaseous elemental mercury (GEM) in air. This phenomenon is known as an atmospheric mercury depletion event (AMDE) and is characterized by sudden and remarkable decreases in GEM that occurs within hours or days. All or most part of the GEM in air is transformed into gaseous oxidized mercury (GOM) and particulate mercury (HgP). Equivalent ozone depletion events (ODE) do also occur in Antarctic and Arctic regions and the halogen radical photolytic processes involved for AMDEs and ODEs are interrelated. During two oceanographic campaigns at the Weddell Sea onboard RV Polarstern, ANTXXIX/6 (130608-130812) and ANTXXIX/7 (130814-131016), continuous measurements of GEM, GOM and HgP in air were performed using the Tekran mercury speciation system 1130/35. This is the first time such long time series of GEM-, GOM- and HgP data has been achieved over water in the Antarctic during winter and spring. Several mercury depletion events were detected as early as in the middle of July and are correlated and verified with ozone measurements onboard the ship. The observed depletion events were characterised by sudden major decreases in both GEM and ozone concentrations and highly elevated values of HgP. A depletion event is a local phenomenon but evidences show that traces of such events can be detected far away from its origin. During a spring campaign at the Pallas-Matorova station in northern Finland (68o00'N, 24o14'E), GEM, GOM and HgP were measured during three weeks in April 2012 using the Tekran mercury speciation system 1130/35. Traces of remote AMDEs were observed by sudden decreases of GEM

  6. The Case of Ozone Depletion

    NASA Technical Reports Server (NTRS)

    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.

  7. Efficacy of a minimal home-based psychoeducative intervention versus usual care for managing anxiety and dyspnoea in patients with severe chronic obstructive pulmonary disease: a randomised controlled trial protocol

    PubMed Central

    Bove, Dorthe Gaby; Overgaard, Dorthe; Lomborg, Kirsten; Lindhardt, Bjarne Ørskov; Midtgaard, Julie

    2015-01-01

    Introduction In its final stages, chronic obstructive pulmonary disease is a severely disabling condition that is characterised by dyspnoea, which causes substantial anxiety. Anxiety is associated with an impaired quality of life and increased hospital admissions. Untreated comorbid anxiety can have devastating consequences for both patients and their relatives. Non-pharmacological interventions, including cognitive–behavioural therapy, have been effective in managing anxiety and dyspnoea in patients with chronic obstructive pulmonary disease. However, the majority of existing interventions have tested the efficacy of relatively intensive comprehensive programmes and primarily targeted patients who have moderate pulmonary disease. We present the rationale and design for a trial that focused on addressing the challenges experienced by severe pulmonary disease populations. The trial investigates the efficacy of a minimal home-based psychoeducative intervention versus usual care for patients with severe chronic obstructive pulmonary disease. Methods and analysis The trial is a randomised controlled trial with a 4-week and 3-month follow-up. 66 patients with severe chronic obstructive pulmonary disease and associated anxiety will be randomised 1:1 to either an intervention or control group. The intervention consists of a single psychoeducative session in the patient's home in combination with a telephone booster session. The intervention is based on a manual, with a theoretical foundation in cognitive–behavioural therapy and psychoeducation. The primary outcome is patient-reported anxiety as assessed by the Hospital and Anxiety and Depression Scale (HADS). Ethics and dissemination This trial complies with the latest Declaration of Helsinki, and The Ethics Committee of the Capital Region of Denmark (number H-1-2013-092) was queried for ethical approval. Trial results will be disseminated in peer-reviewed publications and presented at scientific conferences. Trial

  8. The 1988 Antarctic ozone depletion: Comparison with previous year depletions

    SciTech Connect

    Schoeberl, M.R.; Stolarski, R.S.; Krueger, A.J. )

    1989-05-01

    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% during September 1988 compared to nearly 50% 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{degree}-60{degree}S. The standard deviation also correlates with the QBO cycling of the tropical winds. Mechanisms through which the increased midlatitude eddy activity could disrupt the formation of the Antarctic ozone hole are briefly discussed.

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

    NASA Technical Reports Server (NTRS)

    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.

  10. Fully depleted, thick, monolithic CMOS pixels with high quantum efficiency

    NASA Astrophysics Data System (ADS)

    Clarke, A.; Stefanov, K.; Johnston, N.; Holland, A.

    2015-04-01

    The Centre for Electronic Imaging (CEI) has an active programme of evaluating and designing Complementary Metal-Oxide Semiconductor (CMOS) image sensors with high quantum efficiency, for applications in near-infrared and X-ray photon detection. This paper describes the performance characterisation of CMOS devices made on a high resistivity 50 μ m thick p-type substrate with a particular focus on determining the depletion depth and the quantum efficiency. The test devices contain 8 × 8 pixel arrays using CCD-style charge collection, which are manufactured in a low voltage CMOS process by ESPROS Photonics Corporation (EPC). Measurements include determining under which operating conditions the devices become fully depleted. By projecting a spot using a microscope optic and a LED and biasing the devices over a range of voltages, the depletion depth will change, causing the amount of charge collected in the projected spot to change. We determine if the device is fully depleted by measuring the signal collected from the projected spot. The analysis of spot size and shape is still under development.

  11. Depleted Argon from Underground Sources

    SciTech Connect

    Back, H. O.; Galbiati, C.; Goretti, A.; Loer, B.; Montanari, D.; Mosteiro, P.; Alexander, T.; Alton, A.; Rogers, H.; Kendziora, C.; Pordes, S.

    2011-04-27

    Argon is a strong scintillator and an ideal target for Dark Matter detection; however {sup 39}Ar contamination in atmospheric argon from cosmic ray interactions limits the size of liquid argon dark matter detectors due to pile-up. Argon from deep underground is depleted in {sup 39}Ar due to the cosmic ray shielding of the earth. In Cortez, Colorado, a CO{sub 2} well has been discovered to contain approximately 600 ppm of argon as a contamination in the CO{sub 2}. We first concentrate the argon locally to 3% in an Ar, N{sub 2}, and He mixture, from the CO{sub 2} through chromatographic gas separation, and then the N{sub 2} and He will be removed by continuous distillation to purify the argon. We have collected 26 kg of argon from the CO{sub 2} facility and a cryogenic distillation column is under construction at Fermilab to further purify the argon.

  12. Depleted Argon from Underground Sources

    NASA Astrophysics Data System (ADS)

    Back, H. O.; Alexander, T.; Alton, A.; Galbiati, C.; Goretti, A.; Kendziora, C.; Loer, B.; Montanari, D.; Mosteiro, P.; Pordes, S.; Rogers, H.

    2011-04-01

    Argon is a strong scintillator and an ideal target for Dark Matter detection; however 39Ar contamination in atmospheric argon from cosmic ray interactions limits the size of liquid argon dark matter detectors due to pile-up. Argon from deep underground is depleted in 39Ar due to the cosmic ray shielding of the earth. In Cortez, Colorado, a CO2 well has been discovered to contain approximately 600 ppm of argon as a contamination in the CO2. We first concentrate the argon locally to 3% in an Ar, N2, and He mixture, from the CO2 through chromatographic gas separation, and then the N2 and He will be removed by continuous distillation to purify the argon. We have collected 26 kg of argon from the CO2 facility and a cryogenic distillation column is under construction at Fermilab to further purify the argon.

  13. Bi2Sr2CaCu2O8 + x round wires with Ag/Al oxide dispersion strengthened sheaths: microstructure-properties relationships, enhanced mechanical behavior and reduced Cu depletion

    NASA Astrophysics Data System (ADS)

    Kajbafvala, Amir; Nachtrab, William; Wong, Terence; Schwartz, Justin

    2014-09-01

    Ag/Al alloys with various Al content (0.50 wt%, 0.75 wt%, 1.00 wt%, and 1.25 wt%) are made by powder metallurgy and used as the outer sheath material for Bi2Sr2CaCu2O8 + x (Bi2212)/Ag/AgAl multifilamentary round wires (RW). Bi2212/Ag/AgAl RW microstructural, mechanical and electrical properties are studied in various conditions, including as-drawn, after internal oxidation, and after partial melt processing (PMP). The results are compared with the behavior of a Bi2212/Ag/Ag0.20Mg wire of the same geometry. The grains in as-drawn Ag/Al alloys are found to be ˜25% smaller than those in the corresponding Ag/0.20 wt%Mg, but after PMP, the Ag/Al and Ag/0.20 wt%Mg grain sizes are comparable. Tensile tests show that Bi2212/Ag/AgAl green wires have yield strength (YS) of ˜115 MPa, nearly 65% higher than that of Bi2212/Ag/Ag0.20Mg. After PMP, the Bi2212/Ag/AgAl YS is about 35% greater than that of Bi2212/Ag/Ag0.20Mg. Furthermore, Bi2212/Ag/AgAl wires exhibit higher ultimate tensile strength and modulus and twice the elongation-to-failure. Atomic resolution high-angle annular dark-field scanning transmission electron microscopy, high resolution transmission electron microscopy and energy dispersive spectroscopy demonstrate the formation of nanosize MgO and Al2O3 precipitates via internal oxidation. Large spherical MgO precipitates are observed on the Ag grain boundaries of Ag/0.20 wt%Mg alloy, whereas the Al2O3 precipitates are distributed homogenously in the dispersion-strengthened (DS) Ag/Al alloy. Furthermore, it is found that less Cu diffused from the Bi2212 filaments in the Bi2212/Ag/Ag0.75Al wire during PMP than from the filaments in the Bi2212/Ag/Ag0.20Mg wire. These results show that DS Ag/Al alloy is a strong candidate for improved Bi2212 wire.

  14. Diallyl disulphide depletes glutathione in Candida albicans

    PubMed Central

    Lemar, Katey M.; Aon, Miguel A.; Cortassa, Sonia; O’Rourke, Brian; T. Müller, Carsten; Lloyd, David

    2008-01-01

    Using two-photon scanning laser microscopy, we investigated the effect of an Allium sativum (garlic) constituent, diallyl disulphide (DADS), on key physiological functions of the opportunistic pathogen Candida albicans. A short 30 min exposure to 0.5 mm DADS followed by removal induced 70% cell death (50% necrotic, 20% apoptotic) within 2 h, increasing to 75% after 4 h. The early intracellular events associated with DADS-induced cell death were monitored with two-photon fluorescence microscopy to track mitochondrial membrane potential (ΔΨm), reactive oxygen species (ROS) and NADH or reduced glutathione (GSH) under aerobic conditions. DADS treatment decreased intracellular GSH and elevated intracellular ROS levels. Additionally, DADS induced a marked decrease of ΔΨm and lowered respiration in cell suspensions and isolated mitochondria. In vitro kinetic experiments in cell-free extracts suggest that glutathione-S-transferase (GST) is one of the intracellular targets of DADS. Additional targets were also identified, including inhibition of a site or sites between complexes II-IV in the electron transport chain, as well as the mitochondrial ATP-synthase. The results indicate that DADS is an effective antifungal agent able to trigger cell death in Candida, most probably by eliciting oxidative stress as a consequence of thiol depletion and impaired mitochondrial function. PMID:17534841

  15. High-voltage-compatible, fully depleted CCDs

    SciTech Connect

    Holland, Stephen E.; Bebek, Chris J.; Dawson, Kyle S.; Emes, JohnE.; Fabricius, Max H.; Fairfield, Jessaym A.; Groom, Don E.; Karcher, A.; Kolbe, William F.; Palaio, Nick P.; Roe, Natalie A.; Wang, Guobin

    2006-05-15

    We describe charge-coupled device (CCD) developmentactivities at the Lawrence Berkeley National Laboratory (LBNL).Back-illuminated CCDs fabricated on 200-300 mu m thick, fully depleted,high-resistivity silicon substrates are produced in partnership with acommercial CCD foundry.The CCDs are fully depleted by the application ofa substrate bias voltage. Spatial resolution considerations requireoperation of thick, fully depleted CCDs at high substrate bias voltages.We have developed CCDs that are compatible with substrate bias voltagesof at least 200V. This improves spatial resolution for a given thickness,and allows for full depletion of thicker CCDs than previously considered.We have demonstrated full depletion of 650-675 mu m thick CCDs, withpotential applications in direct x-ray detection. In this work we discussthe issues related to high-voltage operation of fully depleted CCDs, aswell as experimental results on high-voltage-compatible CCDs.

  16. Fully-depleted, back-illuminated charge-coupled devices fabricated on high-resistivity silicon

    SciTech Connect

    Holland, Stephen E.; Groom, Donald E.; Palaio, Nick P.; Stover, Richard J.; Wei, Mingzhi

    2002-03-28

    Charge-coupled devices (CCD's) have been fabricated on high-resistivity silicon. The resistivity, on the order of 10,000 {Omega}-cm, allows for depletion depths of several hundred microns. Fully-depleted, back-illuminated operation is achieved by the application of a bias voltage to a ohmic contact on the wafer back side consisting of a thin in-situ doped polycrystalline silicon layer capped by indium tin oxide and silicon dioxide. This thin contact allows for good short wavelength response, while the relatively large depleted thickness results in good near-infrared response.

  17. CO depletion in the Gould Belt clouds

    NASA Astrophysics Data System (ADS)

    Christie, H.; Viti, S.; Yates, J.; Hatchell, J.; Fuller, G. A.; Duarte-Cabral, A.; Sadavoy, S.; Buckle, J. V.; Graves, S.; Roberts, J.; Nutter, D.; Davis, C.; White, G. J.; Hogerheijde, M.; Ward-Thompson, D.; Butner, H.; Richer, J.; Di Francesco, J.

    2012-05-01

    We present a statistical comparison of CO depletion in a set of local molecular clouds within the Gould Belt using Sub-millimetre Common User Bolometer Array (SCUBA) and Heterodyne Array Receiver Programme (HARP) data. This is the most wide-ranging study of depletion thus far within the Gould Belt. We estimate CO column densities assuming local thermodynamic equilibrium and, for a selection of sources, using the radiative transfer code RADEX in order to compare the two column density estimation methods. High levels of depletion are seen in the centres of several dust cores in all the clouds. We find that in the gas surrounding protostars, levels of depletion are somewhat lower than for starless cores with the exception of a few highly depleted protostellar cores in Serpens and NGC 2024. There is a tentative correlation between core mass and core depletion, particularly in Taurus and Serpens. Taurus has, on average, the highest levels of depletion. Ophiuchus has low average levels of depletion which could perhaps be related to the anomalous dust grain size distribution observed in this cloud. High levels of depletion are often seen around the edges of regions of optical emission (Orion) or in more evolved or less dynamic regions such as the bowl of L1495 in Taurus and the north-western region of Serpens.

  18. Ego depletion increases risk-taking.

    PubMed

    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. PMID:22931000

  19. Depleted uranium hexafluoride: The source material for advanced shielding systems

    SciTech Connect

    Quapp, W.J.; Lessing, P.A.; Cooley, C.R.

    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.

  20. Mercury Depletion Episode Studies in the Canadian High Arctic

    NASA Astrophysics Data System (ADS)

    Steffen, A.; Schroeder, W.; Hoenniger, G.; Platt, U.; Lawson, G.

    2001-12-01

    Episodic mercury depletion episodes were first recorded in Alert, Canada in 1995. Since this time, considerable research has been undertaken to further study this phenomenon. It has been found that there is an occurrence of fast photo-chemically induced reactions involving the oxidation of Hg (0) to Hg (II) during the springtime period in the high Arctic. Data from a cold regions pyrolysis unit (CRPU) have confirmed that particle-associated mercury (PM) and reactive gaseous mercury (RGM) are still present in the air during a mercury depletion event when Hg (0) concentration levels are very low. These more reactive species are less volatile and are more readily removed in the air and/or are deposited on the snow surfaces than Hg (0). In the winter and spring of 2000 in Alert, snow samples collected showed an almost 20 fold increase in mercury concentrations during the springtime period from the dark period. Air profiling measurements undertaken during the same time period have shown that Hg (0) is re-emitted from the snow pack surfaces both over land and the frozen Arctic Ocean near Alert. It is thought that free radical BrO is responsible for the destruction of ozone depletion episodes in the Arctic during springtime and increased concentrations from satellites have been measured during these times. Ground level in situ measurements taken over the frozen ocean during depletion events showed an anti-correlation between Hg (0) and BrO concentrations during MDEs. In February 2001, continuous automated RGM and PM measurements were initiated to further study this phenomenon in parallel with the CRPU to measure total atmospheric mercury concentrations in ambient air in the Canadian Arctic during springtime depletion events. A summary of findings from these studies will be presented.

  1. Mechanism-based biomarker gene sets for glutathione depletion-related hepatotoxicity in rats

    SciTech Connect

    Gao Weihua; Mizukawa, Yumiko; Nakatsu, Noriyuki; Minowa, Yosuke; Yamada, Hiroshi; Ohno, Yasuo; Urushidani, Tetsuro

    2010-09-15

    Chemical-induced glutathione depletion is thought to be caused by two types of toxicological mechanisms: PHO-type glutathione depletion [glutathione conjugated with chemicals such as phorone (PHO) or diethyl maleate (DEM)], and BSO-type glutathione depletion [i.e., glutathione synthesis inhibited by chemicals such as L-buthionine-sulfoximine (BSO)]. In order to identify mechanism-based biomarker gene sets for glutathione depletion in rat liver, male SD rats were treated with various chemicals including PHO (40, 120 and 400 mg/kg), DEM (80, 240 and 800 mg/kg), BSO (150, 450 and 1500 mg/kg), and bromobenzene (BBZ, 10, 100 and 300 mg/kg). Liver samples were taken 3, 6, 9 and 24 h after administration and examined for hepatic glutathione content, physiological and pathological changes, and gene expression changes using Affymetrix GeneChip Arrays. To identify differentially expressed probe sets in response to glutathione depletion, we focused on the following two courses of events for the two types of mechanisms of glutathione depletion: a) gene expression changes occurring simultaneously in response to glutathione depletion, and b) gene expression changes after glutathione was depleted. The gene expression profiles of the identified probe sets for the two types of glutathione depletion differed markedly at times during and after glutathione depletion, whereas Srxn1 was markedly increased for both types as glutathione was depleted, suggesting that Srxn1 is a key molecule in oxidative stress related to glutathione. The extracted probe sets were refined and verified using various compounds including 13 additional positive or negative compounds, and they established two useful marker sets. One contained three probe sets (Akr7a3, Trib3 and Gstp1) that could detect conjugation-type glutathione depletors any time within 24 h after dosing, and the other contained 14 probe sets that could detect glutathione depletors by any mechanism. These two sets, with appropriate scoring

  2. Depleted argon from underground sources

    SciTech Connect

    Back, H.O.; Alton, A.; Calaprice, F.; Galbiati, C.; Goretti, A.; Kendziora, C.; Loer, B.; Montanari, D.; Mosteiro, P.; 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.

  3. Depleted Argon from Underground Sources

    NASA Astrophysics Data System (ADS)

    Back, H. O.; Alton, A.; Calaprice, F.; Galbiati, C.; Goretti, A.; Kendziora, C.; Loer, B.; Montanari, D.; Mosteiro, P.; Pordes, S.

    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 39Ar 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 39Ar. In Cortez Colorado a CO2 well has been discovered to contain approximately 500 ppm of argon as a contamination in the CO2. In order to produce argon for dark matter detectors we first concentrate the argon locally to 3-5% in an Ar, N2, and He mixture, from the CO2 through chromatographic gas separation. The N2 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.

  4. Tritium transport vessel using depleted uranium

    SciTech Connect

    Heung, L.K.

    1995-01-01

    A tritium transport vessel using depleted uranium was tested in the laboratory using deuterium and protium. The vessel contains 0.5 kg of depleted uranium and can hold up to 18 grams of tritium. The conditions for activation, tritium loading and tritium unloading were defined. The safety aspects that included air-ingress, tritium diffusion, temperature and pressure potentials were evaluated.

  5. Specification for the VERA Depletion Benchmark Suite

    SciTech Connect

    Kim, Kang Seog

    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.

  6. High homocysteine induces betaine depletion.

    PubMed

    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.

  7. Gulf war depleted uranium risks.

    PubMed

    Marshall, Albert C

    2008-01-01

    US and British forces used depleted uranium (DU) in armor-piercing rounds to disable enemy tanks during the Gulf and Balkan Wars. Uranium particulate is generated by DU shell impact and particulate entrained in air may be inhaled or ingested by troops and nearby civilian populations. As uranium is slightly radioactive and chemically toxic, a number of critics have asserted that DU exposure has resulted in a variety of adverse health effects for exposed veterans and nearby civilian populations. The study described in this paper used mathematical modeling to estimate health risks from exposure to DU during the 1991 Gulf War for both US troops and nearby Iraqi civilians. The analysis found that the risks of DU-induced leukemia or birth defects are far too small to result in an observable increase in these health effects among exposed veterans or Iraqi civilians. The analysis indicated that only a few ( approximately 5) US veterans in vehicles accidentally targeted by US tanks received significant exposure levels, resulting in about a 1.4% lifetime risk of DU radiation-induced fatal cancer (compared with about a 24% risk of a fatal cancer from all other causes). These veterans may have also experienced temporary kidney damage. Iraqi children playing for 500 h in DU-destroyed vehicles are predicted to incur a cancer risk of about 0.4%. In vitro and animal tests suggest the possibility of chemically induced health effects from DU internalization, such as immune system impairment. Further study is needed to determine the applicability of these findings for Gulf War exposure to DU. Veterans and civilians who did not occupy DU-contaminated vehicles are unlikely to have internalized quantities of DU significantly in excess of normal internalization of natural uranium from the environment.

  8. A parallel algorithm for implicit depletant simulations

    NASA Astrophysics Data System (ADS)

    Glaser, Jens; Karas, Andrew S.; Glotzer, Sharon C.

    2015-11-01

    We present an algorithm to simulate the many-body depletion interaction between anisotropic colloids in an implicit way, integrating out the degrees of freedom of the depletants, which we treat as an ideal gas. Because the depletant particles are statistically independent and the depletion interaction is short-ranged, depletants are randomly inserted in parallel into the excluded volume surrounding a single translated and/or rotated colloid. A configurational bias scheme is used to enhance the acceptance rate. The method is validated and benchmarked both on multi-core processors and graphics processing units for the case of hard spheres, hemispheres, and discoids. With depletants, we report novel cluster phases in which hemispheres first assemble into spheres, which then form ordered hcp/fcc lattices. The method is significantly faster than any method without cluster moves and that tracks depletants explicitly, for systems of colloid packing fraction ϕc < 0.50, and additionally enables simulation of the fluid-solid transition.

  9. Fully Depleted Charge-Coupled Devices

    SciTech Connect

    Holland, Stephen E.

    2006-05-15

    We have developed fully depleted, back-illuminated CCDs thatbuild upon earlier research and development efforts directed towardstechnology development of silicon-strip detectors used inhigh-energy-physics experiments. The CCDs are fabricated on the same typeof high-resistivity, float-zone-refined silicon that is used for stripdetectors. The use of high-resistivity substrates allows for thickdepletion regions, on the order of 200-300 um, with corresponding highdetection efficiency for near-infrared andsoft x-ray photons. We comparethe fully depleted CCD to thep-i-n diode upon which it is based, anddescribe the use of fully depleted CCDs in astronomical and x-ray imagingapplications.

  10. In Vivo Depletion of T Lymphocytes.

    PubMed

    Laky, Karen; Kruisbeek, Ada M

    2016-01-01

    In vivo depletion of T lymphocytes is a means of studying the role of specific T cell populations during defined phases of in vivo immune responses. In this unit, a protocol is provided for injecting monoclonal antibodies (mAbs) into wild-type adult mice. Depletion of the appropriate subset of cells is verified by flow cytometry analysis of lymph node and spleen cell suspensions in pilot experiments. Once conditions have been established, depleted mice can be used to study the impact of T cell subsets on a variety of in vivo immune responses. The depleted condition may be maintained by repeated injections of the monoclonal antibody, or reversed by normal thymopoiesis following discontinuation of antibody administration. PMID:27038463

  11. A definition of depletion of fish stocks

    USGS Publications Warehouse

    Van Oosten, John

    1949-01-01

    Attention was focused on the need of a common and better understanding of the term depletion as applied to the fisheries in order to eliminate if possible the existing inexactness of thought on the subject. Depletion has been confused at various times with at least ten different ideas associated with it but which, as has has heen pointed out, are not synonymous at all. In defining depletion we must recognize that the term represents a condition and must not he confounded with the cause (overfishing) that leads to this condition or with the symptoms that identify it. Depletion was defined as a reduction, through overfishing, in the level of abundance of the exploitable segment of a stock that prevents the realization of the maximum productive capacity.

  12. Silicon Depletion in the Interstellar Medium

    NASA Astrophysics Data System (ADS)

    Haris, U.; Parvathi, V. S.; Gudennavar, S. B.; Bubbly, S. G.; Murthy, J.; Sofia, U. J.

    2016-06-01

    We report interstellar silicon (Si) depletion and dust-phase column densities of Si along 131 Galactic sight lines using archival observations. The data were corrected for differences in the assumed oscillator strength. This is a much larger sample than previous studies but confirms the majority of results, which state that the depletion of Si is correlated with the average density of hydrogen along the line of sight (< n({{H}})> ) as well as the fraction of hydrogen in molecular form (f(H2)). We also find that the linear part of the extinction curve is independent of Si depletion. Si depletion is correlated with the bump strength (c3/RV) and the FUV curvature (c4/RV) suggesting that silicon plays a significant role in both the 2175 Å bump and the FUV rise.

  13. Polar stratospheric clouds and ozone depletion

    NASA Technical Reports Server (NTRS)

    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.

  14. A theoretical model of atmospheric ozone depletion

    NASA Astrophysics Data System (ADS)

    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.

  15. The New MCNP6 Depletion Capability

    SciTech Connect

    Fensin, Michael Lorne; James, Michael R.; Hendricks, John S.; Goorley, John T.

    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.

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

    PubMed

    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.

  17. Global Warming: Lessons from Ozone Depletion

    NASA Astrophysics Data System (ADS)

    Hobson, Art

    2010-11-01

    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 Arkansas have developed a conceptual understanding of energy and of electromagnetism, including the electromagnetic spectrum, I devote a lecture (and a textbook section) to ozone depletion and another lecture (and section) to global warming. Humankind came together in 1986 and quickly solved, to the extent that humans can solve it, ozone depletion. We could do the same with global warming, but we haven't and as yet there's no sign that we will. The parallel between the ozone and global warming cases, and the difference in outcomes, are striking and instructive.

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

    PubMed

    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.

  19. Ozone depletion and chlorine loading potentials

    NASA Technical Reports Server (NTRS)

    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.

  20. Neutral depletion and the helicon density limit

    SciTech Connect

    Magee, R. M.; Galante, M. E.; Carr, J. Jr.; Lusk, G.; McCarren, D. W.; Scime, E. E.

    2013-12-15

    It is straightforward to create fully ionized plasmas with modest rf power in a helicon. It is difficult, however, to create plasmas with density >10{sup 20} m{sup −3}, because neutral depletion leads to a lack of fuel. In order to address this density limit, we present fast (1 MHz), time-resolved measurements of the neutral density at and downstream from the rf antenna in krypton helicon plasmas. At the start of the discharge, the neutral density underneath the antenna is reduced to 1% of its initial value in 15 μs. The ionization rate inferred from these data implies that the electron temperature near the antenna is much higher than the electron temperature measured downstream. Neutral density measurements made downstream from the antenna show much slower depletion, requiring 14 ms to decrease by a factor of 1/e. Furthermore, the downstream depletion appears to be due to neutral pumping rather than ionization.

  1. D0 Decomissioning : Storage of Depleted Uranium Modules Inside D0 Calorimeters after the Termination of D0 Experiment

    SciTech Connect

    Sarychev, Michael; /Fermilab

    2011-09-21

    Dzero liquid Argon calorimeters contain hadronic modules made of depleted uranium plates. After the termination of DO detector's operation, liquid Argon will be transferred back to Argon storage Dewar, and all three calorimeters will be warmed up. At this point, there is no intention to disassemble the calorimeters. The depleted uranium modules will stay inside the cryostats. Depleted uranium is a by-product of the uranium enrichment process. It is slightly radioactive, emits alpha, beta and gamma radiation. External radiation hazards are minimal. Alpha radiation has no external exposure hazards, as dead layers of skin stop it; beta radiation might have effects only when there is a direct contact with skin; and gamma rays are negligible - levels are extremely low. Depleted uranium is a pyrophoric material. Small particles (such as shavings, powder etc.) may ignite with presence of Oxygen (air). Also, in presence of air and moisture it can oxidize. Depleted uranium can absorb moisture and keep oxidizing later, even after air and moisture are excluded. Uranium oxide can powder and flake off. This powder is also pyrographic. Uranium oxide may create health problems if inhaled. Since uranium oxide is water soluble, it may enter the bloodstream and cause toxic effects.

  2. Depletion potential in the infinite dilution limit

    NASA Astrophysics Data System (ADS)

    Yuste, Santos Bravo; Santos, Andrés; López de Haro, Mariano

    2008-04-01

    The depletion force and depletion potential between two in principle unequal "big" hard spheres embedded in a multicomponent mixture of "small" hard spheres are computed using the rational function approximation method for the structural properties of hard-sphere mixtures [S. B. Yuste, A. Santos, and M. López de Haro, J. Chem. Phys. 108, 3683 (1998)]. The cases of equal solute particles and of one big particle and a hard planar wall in a background monodisperse hard-sphere fluid are explicitly analyzed. An improvement over the performance of the Percus-Yevick theory and good agreement with available simulation results are found.

  3. The depletion of interstellar gaseous iron

    NASA Technical Reports Server (NTRS)

    Savage, B. D.; Bohlin, R. C.

    1979-01-01

    The Copernicus UV telescope was used to measure equivalent widths of interstellar Fe II resonance lines toward 55 early-type stars; the measurements permit the determination of Fe II column densities. The depletion of interstellar gaseous iron was obtained by combining these measurements with the results from a previous atomic and molecular hydrogen survey program; the derived depletions refer mostly to matter in H I regions. As an example, the nearly normal gaseous iron abundance in the distant high-latitude intermediate-velocity cloud toward HD 93521 is consistent with the idea that these clouds are produced by galactic supernova explosions.

  4. Ozone potentiates vitamin E depletion by ultraviolet radiation in the murine stratum corneum.

    PubMed

    Valacchi, G; Weber, S U; Luu, C; Cross, C E; Packer, L

    2000-01-21

    As the outermost layer of the skin, the stratum corneum is exposed to environmental oxidants. To investigate putative synergisms of environmental oxidative stressors in stratum corneum, hairless mice were exposed to ultraviolet radiation (UV) and ozone (O(3)) alone and in combination. Whereas a significant depletion of alpha-tocopherol was observed after individual exposure to either a 0.5 minimal erythemal dose of UV or 1 ppm O(3) for 2 h, the combination did not increase the effect of UV alone. However, a dose of 0.5 ppm O(3) x 2 h, which had no effect when used alone, significantly enhanced the UV-induced depletion of vitamin E. We conclude that concomitant exposure to low doses of UV and O(3) at levels near those that humans can be exposed to causes additive oxidative stress in the stratum corneum.

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

    SciTech Connect

    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. 50 CFR 216.15 - Depleted species.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Depleted species. 216.15 Section 216.15 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE...

  7. Neutral depletion versus repletion due to ionization

    SciTech Connect

    Fruchtman, A.; Makrinich, G.; Raimbault, J.-L.; Liard, L.; Rax, J.-M.; Chabert, P.

    2008-05-15

    Recent theoretical analyses which predicted unexpected effects of neutral depletion in both collisional and collisionless plasmas are reviewed. We focus on the depletion of collisionless neutrals induced by strong ionization of a collisionless plasma and contrast this depletion with the effect of strong ionization on thermalized neutrals. The collisionless plasma is analyzed employing a kinetic description. The collisionless neutrals and the plasma are coupled through volume ionization and wall recombination only. The profiles of density and pressure both of the plasma and of the neutral-gas and the profile of the ionization rate are calculated. It is shown that for collisionless neutrals the ionization results in neutral depletion, while when neutrals are thermalized the ionization induces a maximal neutral-density at the discharge center, which we call neutral repletion. The difference between the two cases stems from the relation between the neutral density and pressure. The pressure of the collisionless neutral-gas turns out to be maximal where its density is minimal, in contrast to the case of a thermalized neutral gas.

  8. 50 CFR 216.15 - Depleted species.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 10 2014-10-01 2014-10-01 false Depleted species. 216.15 Section 216.15 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION..., Prince William Sound, Yakutat Bay, Shelikof Strait, and off Kodiak Island and freshwater tributaries...

  9. 50 CFR 216.15 - Depleted species.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false Depleted species. 216.15 Section 216.15 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION..., Prince William Sound, Yakutat Bay, Shelikof Strait, and off Kodiak Island and freshwater tributaries...

  10. Global Warming: Lessons from Ozone Depletion

    ERIC Educational Resources Information Center

    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…

  11. Demonstration of jackhammer incorporating depleted uranium

    SciTech Connect

    Fischer, L E; Hoard, R W; Carter, D L; Saculla, M D; Wilson, G V

    2000-04-01

    The United States Government currently has an abundance of depleted uranium (DU). This surplus of about 1 billion pounds is the result of an enrichment process using gaseous diffusion to produce enriched and depleted uranium. The enriched uranium has been used primarily for either nuclear weapons for the military or nuclear fuel for the commercial power industry. Most of the depleted uranium remains at the enrichment process plants in the form of depleted uranium hexafluoride (DUF{sub 6}). The Department of Energy (DOE) recently began a study to identify possible commercial applications for the surplus material. One of these potential applications is to use the DU in high-density strikers/hammers in pneumatically driven tools, such as jack hammers and piledrivers to improve their impulse performance. The use of DU could potentially increase tunneling velocity and excavation into target materials with improved efficiency. This report describes the efforts undertaken to analyze the particulars of using DU in two specific striking applications: the jackhammer and chipper tool.

  12. Platelet depletion and severity of streptococcal endocarditis

    PubMed Central

    Dall, Lawrence; Miller, Todd; Herndon, Betty; Diez, Ireneo; Dew, Michelle

    1998-01-01

    OBJECTIVE: To evaluate the importance of thrombocytopenia in streptococcal endocarditis using an animal model. DESIGN: A model of human septic endocarditis was established in rats (polyethylene catheters across the aortic valve and administration of Streptococcus sanguis, 5×107 colony forming units [cfu] intravenous). Thrombocytopenia at four levels was produced by antiplatelet serum. Secondary methods of producing thrombocytopenia were also evaluated. At sacrifice (96 h after platelet depletion and 72 h after infection), vegetations were removed, weighed, diluted, plated and counted. Potential mechanisms of the dose-response relationship between vegetation density and platelet count were evaluated. SETTING: Controlled research laboratory experiments. POPULATION STUDIED: Animal models of streptococcal endocarditis. MAIN RESULTS: The bacterial density of the aortic valve vegetations significantly increased as the platelet count decreased (P=0.0007). In severely thrombocytopenic animals (two-dose antiplatelet serum), data suggest increased vegetation embolism. Platelet depletion, which was minimal with chemical methods, was produced most effectively by antithrombocyte serum. Platelet surfaces in endocarditis were found to express elevated CD62p proteins (72.7% endocarditis, 34.7% control). Platelet protein fractions were evaluated in vitro by both streptocidal (P=0.19) and phagocytosis-stimulating assays. Platelet presence in mature aortic valve vegetations averaged only about 2%. CONCLUSIONS: In platelet depletion experiments using a rat model, a dose-response relationship of peripheral circulating platelet depletion to aortic valve vegetation density was found. The mechanism relating thrombocytopenia to endocarditis severity remains unresolved. PMID:22346555

  13. Dissolution Treatment of Depleted Uranium Waste

    SciTech Connect

    Gates-Anderson, D D; Laue, C A; Fitch, T E

    2004-02-09

    Researchers at LLNL have developed a 3-stage process that converts pyrophoric depleted uranium metal turnings to a solidified final product that can be transported to and buried at a permitted land disposal site. The three process stages are: (1) pretreatment; (2) dissolution; and (3) solidification. Each stage was developed following extensive experimentation. This report presents the results of their experimental studies.

  14. Carbon depletion in turbulent molecular cloud cores

    NASA Astrophysics Data System (ADS)

    Boland, W.; de Jong, T.

    1982-10-01

    Observations of dense molecular cores indicate that about 10% of the carbon is still in the gas phase (depletion factor of about 0.1) in spite of the fact that the depletion time - the time needed for heavy elements to freeze out on dust grains - is several orders of magnitude smaller than the cloud lifetime. To resolve this problem, it is suggested that the material in molecular cloud cores is circulated by turbulence and that every time a parcel of gas and dust reaches the outer layers of the core, dust mantles that have formed by accretion in the center are evaporated and/or photodesorbed. The observed mild degree of depletion results because the circulation time and the depletion time are of the same order of magnitude. Since the time to reach molecular equilibrium in the outer layers of a cloud core is short compared with the circulation time the dust plays no role in the chemistry. In the center of a cloud core, the time to convert C to CO is of the order of the circulation time, so that an appreciable fraction of the gaseous carbon remains in atomic form. From a brief discussion of the energetics, it is concluded that the turbulence observed in molecular cloud cores can be maintained during the lifetime of the cloud if the envelope collapses onto the core at a rate of about 0.000001 solar mass per year.

  15. Contrasts between Antarctic and Arctic ozone depletion.

    PubMed

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

    2007-01-01

    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. PMID:17202269

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

    PubMed Central

    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

  17. How Depleted is the MORB mantle?

    NASA Astrophysics Data System (ADS)

    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. Highly isotopically depleted isoprenoids: Molecular markers for ancient methane venting

    NASA Astrophysics Data System (ADS)

    Thiel, Volker; Peckmann, Jörn; Seifert, Richard; Wehrung, Patrick; Reitner, Joachim; Michaelis, Walter

    1999-12-01

    We propose that organic compounds found in a Miocene limestone from Marmorito (Northern Italy) are source markers for organic matter present in ancient methane vent systems (cold seeps). The limestone contains high concentrations of the tail-to-tail linked, acyclic C 20 isoprenoid 2,6,11,15-tetramethylhexadecane (crocetane), a C 25 homolog 2,6,10,15,19-pentamethylicosane (PME), and a distinctive glycerol ether lipid containing 3,7,11,15-tetramethylhexadecyl (phytanyl-) moieties. The chemical structures of these biomarkers indicate a common origin from archaea. Their extremely 13C-depleted isotope compositions (δ 13C ≈ -108 to -115.6‰ PDB) suggest that the respective archaea have directly or indirectly introduced isotopically depleted, methane-derived carbon into their biomass. We postulate that a second major cluster of biomarkers showing heavier isotope values (δ 13C ≈ -88‰) is derived from sulfate-reducing bacteria (SRB). The observed biomarkers sustain the idea that methanogenic bacteria, in a syntrophic community with SRB, are responsible for the anaerobic oxidation of methane in marine sediments. Marmorito may thus represent a conceivable ancient scenario for methane consumption performed by a defined, two-membered bacterial consortium: (1) archaea that perform reversed methanogenesis by oxidizing methane and producing CO 2 and H 2; and (2) SRB that consume the resulting H 2. Furthermore, the respective organic molecules are, unlike other compounds, tightly bound to the crystalline carbonate phase. The Marmorito carbonates can thus be regarded as "cold seep microbialites" rather than mere "authigenic" carbonates.

  19. A worldwide view of groundwater depletion

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    During the last decades, global water demand has increased two-fold due to increasing population, expanding irrigated area and economic development. Globally such demand can be met by surface water availability (i.e., water in rivers, lakes and reservoirs) but regional variations are large and the absence of sufficient rainfall and run-off increasingly encourages the use of groundwater resources, particularly in the (semi-)arid regions of the world. Excessive abstraction for irrigation frequently leads to overexploitation, i.e. if groundwater abstraction exceeds the natural groundwater recharge over extensive areas and prolonged times, persistent groundwater depletion may occur. Observations and various regional studies have revealed that groundwater depletion is a substantial issue in regions such as Northwest India, Northeast Pakistan, Central USA, Northeast China and Iran. Here we provide a global overview of groundwater depletion from the year 1960 to 2000 at a spatial resolution of 0.5 degree by assessing groundwater recharge with the global hydrological model PCR-GLOBWB and subtracting estimates of groundwater abstraction obtained from IGRAC-GGIS database. PCR-GLOBWB was forced by the CRU climate dataset downscaled to daily time steps using ERA40 re-analysis data. PCR-GLOBWB simulates daily global groundwater recharge (0.5 degree) while considering sub-grid variability of each grid cell (e.g., short and tall vegetation, different soil types, fraction of saturated soil). Country statistics of groundwater abstraction were downscaled to 0.5 degree by using water demand (i.e., agriculture, industry and domestic) as a proxy. To limit problems related to increased capture of discharge and increased recharge due to groundwater pumping, we restricted our analysis to sub-humid to arid areas. The uncertainty in the resulting estimates was assessed by a Monte Carlo analysis of 100 realizations of groundwater recharge and 100 realizations of groundwater abstraction

  20. Incorporation of copper ions into crystals of T2 copper-depleted laccase from Botrytis aclada.

    PubMed

    Osipov, E M; Polyakov, K M; Tikhonova, T V; Kittl, R; Dorovatovskii, P V; Shleev, S V; Popov, V O; Ludwig, R

    2015-12-01

    Laccases belong to the class of multicopper oxidases catalyzing the oxidation of phenols accompanied by the reduction of molecular oxygen to water without the formation of hydrogen peroxide. The activity of laccases depends on the number of Cu atoms per enzyme molecule. The structure of type 2 copper-depleted laccase from Botrytis aclada has been solved previously. With the aim of obtaining the structure of the native form of the enzyme, crystals of the depleted laccase were soaked in Cu(+)- and Cu(2+)-containing solutions. Copper ions were found to be incorporated into the active site only when Cu(+) was used. A comparative analysis of the native and depleted forms of the enzymes was performed.

  1. Commonness, population depletion and conservation biology.

    PubMed

    Gaston, Kevin J; Fuller, Richard A

    2008-01-01

    Species conservation practice, as opposed to principle, generally emphasizes species at risk of imminent extinction. This results in priority lists principally of those with small populations and/or geographical ranges. However, recent work emphasizes the importance of common species to ecosystems. Even relatively small proportional declines in their abundance can result in large absolute losses of individuals and biomass, occurrences significantly disrupting ecosystem structure, function and services. Here, we argue that combined with evidence of dramatic declines in once common species, this suggests the need to pay more attention to such depletions. Complementing the focus on extinction risk, we highlight important implications for conservation, including the need to identify, monitor and alleviate significant depletion events.

  2. Copenhagen delegates advance phaseout of ozone depleters

    SciTech Connect

    Kirschner, E.

    1992-12-09

    As expected, delegates at the United Nations Ozone Layer Conference in Copenhagen sped up ozone depleter phaseouts from the 1987 Montreal Protocol and the 1990 London amendments. The changes bring the worldwide production phaseout of chlorofluorocarbons (CFCs) and other ozone depleters in developed countries in line with U.S. and European plans announced earlier this year. Adjustments to the protocol, which are binding on the signatories, change the phaseout for CFC, carbon tetrachloride, and methyl chloroform production and consumption to January 1, 1996 from 2000. The 75% reduction of 1986 levels from CFCs by January 1, 1994 is a compromise between European pressure for an 85% cut and the US goal of 70%. Halon production is to end January 1, 1994, as anticipated. Developing countries continue to have a 10-year grace period. Friends of the Earth ozone campaign director Liz Cook counters that the phaseout dates were scheduled with concern for the chemical industry, not for the ozone layer.

  3. Depleted uranium plasma reduction system study

    SciTech Connect

    Rekemeyer, P.; Feizollahi, F.; Quapp, W.J.; Brown, B.W.

    1994-12-01

    A system life-cycle cost study was conducted of a preliminary design concept for a plasma reduction process for converting depleted uranium to uranium metal and anhydrous HF. The plasma-based process is expected to offer significant economic and environmental advantages over present technology. Depleted Uranium is currently stored in the form of solid UF{sub 6}, of which approximately 575,000 metric tons is stored at three locations in the U.S. The proposed system is preconceptual in nature, but includes all necessary processing equipment and facilities to perform the process. The study has identified total processing cost of approximately $3.00/kg of UF{sub 6} processed. Based on the results of this study, the development of a laboratory-scale system (1 kg/h throughput of UF6) is warranted. Further scaling of the process to pilot scale will be determined after laboratory testing is complete.

  4. Endoplasmic-Reticulum Calcium Depletion and Disease

    PubMed Central

    Mekahli, Djalila; Bultynck, Geert; Parys, Jan B.; De Smedt, Humbert; Missiaen, Ludwig

    2011-01-01

    The endoplasmic reticulum (ER) as an intracellular Ca2+ store not only sets up cytosolic Ca2+ signals, but, among other functions, also assembles and folds newly synthesized proteins. Alterations in ER homeostasis, including severe Ca2+ depletion, are an upstream event in the pathophysiology of many diseases. On the one hand, insufficient release of activator Ca2+ may no longer sustain essential cell functions. On the other hand, loss of luminal Ca2+ causes ER stress and activates an unfolded protein response, which, depending on the duration and severity of the stress, can reestablish normal ER function or lead to cell death. We will review these various diseases by mainly focusing on the mechanisms that cause ER Ca2+ depletion. PMID:21441595

  5. Altitude latitude mapping of plasma depletions

    NASA Astrophysics Data System (ADS)

    Rajesh, P.; Liu, J.; Sinha, H.; Banerje, S.

    2007-12-01

    Plasma depletions, if generated at the geomagnetic equator, are expected to appear in the all sky images as dark bands extending pole ward. The all sky observations conducted from Kavalur (12.5¢ªN, 78.8¢ªE; 4.6¢ªN, geomagnetic), INDIA, but showed dark patches in 630.0 nm entering the imager field of view (FOV) from the northern edge in the post-sunset period. These patches gradually extended towards equator and became fully extended dark bands in the North-South direction by midnight. The series of such images appeared to be the airglow signatures of irregularities that are probably generated at off-equatorial latitudes and mapped to the lower or equatorial latitudes. Similar features were observed in several nights. This appearance of depletions as dark patches from the northern edge of the FOV is explained in this work

  6. Replacements For Ozone-Depleting Foaming Agents

    NASA Technical Reports Server (NTRS)

    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.

  7. Depletion modeling of liquid dominated geothermal reservoirs

    SciTech Connect

    Olsen, G.

    1984-06-01

    Depletion models for liquid-dominated geothermal reservoirs are derived and presented. The depletion models are divided into two categories: confined and unconfined. For both cases depletion models with no recharge (or influx), and depletion models including recharge, are used to match field data from the Svartsengi high temperature geothermal field in Iceland. The influx models included with the mass and energy balances are adopted from the petroleum engineering literature. The match to production data from Svartsengi is improved when influx was included. The Schilthuis steady-state influx gives a satisfactory match. The finite aquifer method of Fetkovitch, and the unsteady state method of Hurst gave reasonable answers, but not as good. The best match is obtained using Hurst simplified solution when lambda = 1.3 x 10{sup -4} m{sup -1}. From the match the cross-sectional area of the aquifer was calculated as 3.6 km{sup 2}. The drawdown was predicted using the Hurst simplified method, and compared with predicted drawdown from a boiling model and an empirical log-log model. A large difference between the models was obtained. The predicted drawdown using the Hurst simplified method falls between the other two. Injection has been considered by defining the net rate as being the production rate minus the injection rate. No thermal of transient effects were taken into account. Prediction using three different net rates shows that the pressure can be maintained using the Hurst simplified method if there is significant fluid reinjection. 32 refs., 44 figs., 2 tabs.

  8. Carbon sequestration in depleted oil shale deposits

    SciTech Connect

    Burnham, Alan K; Carroll, Susan A

    2014-12-02

    A method and apparatus are described for sequestering carbon dioxide underground by mineralizing the carbon dioxide with coinjected fluids and minerals remaining from the extraction shale oil. In one embodiment, the oil shale of an illite-rich oil shale is heated to pyrolyze the shale underground, and carbon dioxide is provided to the remaining depleted oil shale while at an elevated temperature. Conditions are sufficient to mineralize the carbon dioxide.

  9. The ultimate disposition of depleted uranium

    SciTech Connect

    Not Available

    1990-12-01

    Significant amounts of the depleted uranium (DU) created by past uranium enrichment activities have been sold, disposed of commercially, or utilized by defense programs. In recent years, however, the demand for DU has become quite small compared to quantities available, and within the US Department of Energy (DOE) there is concern for any risks and/or cost liabilities that might be associated with the ever-growing inventory of this material. As a result, Martin Marietta Energy Systems, Inc. (Energy Systems), was asked to review options and to develop a comprehensive plan for inventory management and the ultimate disposition of DU accumulated at the gaseous diffusion plants (GDPs). An Energy Systems task team, under the chairmanship of T. R. Lemons, was formed in late 1989 to provide advice and guidance for this task. This report reviews options and recommends actions and objectives in the management of working inventories of partially depleted feed (PDF) materials and for the ultimate disposition of fully depleted uranium (FDU). Actions that should be considered are as follows. (1) Inspect UF{sub 6} cylinders on a semiannual basis. (2) Upgrade cylinder maintenance and storage yards. (3) Convert FDU to U{sub 3}O{sub 8} for long-term storage or disposal. This will include provisions for partial recovery of costs to offset those associated with DU inventory management and the ultimate disposal of FDU. Another recommendation is to drop the term tails'' in favor of depleted uranium'' or DU'' because the tails'' label implies that it is waste.'' 13 refs.

  10. Clara epithelial cell depletion in the lung.

    PubMed

    Sonar, Sanchaita S; Dudda, Jan C

    2013-01-01

    The bronchial epithelium has been increasingly recognized as an important immunomodulatory compartment in asthma and other lung diseases. Clara cells, which comprise the nonciliated secretory epithelial cells, are an important epithelial cell type with functions in the regulation of lung homeostasis and inflammation. Using naphthalene, Clara cells can be depleted within 24 h and regenerate by 1 month, hence, providing an easy method to study the impact of Clara cells on lung inflammation.

  11. The ultimate disposition of depleted uranium

    SciTech Connect

    Lemons, T.R.

    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.

  12. Incorporation of copper ions into crystals of T2 copper-depleted laccase from Botrytis aclada

    SciTech Connect

    Osipov, E. M.; Polyakov, K. M.; Tikhonova, T. V.; Kittl, R.; Dorovatovskii, P.V.; Shleev, S. V.; Popov, V. O.; Ludwig, R.

    2015-11-18

    The restoration of the native form of laccase from B. aclada from the type 2 copper-depleted form of the enzyme was investigated. Copper ions were found to be incorporated into the active site after soaking the depleted enzyme in a Cu{sup +}-containing solution. Laccases belong to the class of multicopper oxidases catalyzing the oxidation of phenols accompanied by the reduction of molecular oxygen to water without the formation of hydrogen peroxide. The activity of laccases depends on the number of Cu atoms per enzyme molecule. The structure of type 2 copper-depleted laccase from Botrytis aclada has been solved previously. With the aim of obtaining the structure of the native form of the enzyme, crystals of the depleted laccase were soaked in Cu{sup +}- and Cu{sup 2+}-containing solutions. Copper ions were found to be incorporated into the active site only when Cu{sup +} was used. A comparative analysis of the native and depleted forms of the enzymes was performed.

  13. Pumping test evaluation of stream depletion parameters.

    PubMed

    Lough, Hilary K; Hunt, Bruce

    2006-01-01

    Descriptions are given of a pumping test and a corresponding analysis that permit calculation of all five hydrogeological parameters appearing in the Hunt (2003) solution for stream depletion caused by ground water abstraction from a well beside a stream. This solution assumes that flow in the pumped aquifer is horizontal, flow in the overlying aquitard or system of aquitards is vertical, and the free surface in the top aquitard is allowed to draw down. The definition of an aquitard in this paper is any layer with a vertical hydraulic conductivity much lower than the horizontal hydraulic conductivity of the pumped aquifer. These "aquitards" may be reasonably permeable layers but are distinguished from the pumped aquifer by their hydraulic conductivity contrast. The pumping test requires a complete set of drawdown measurements from at least one observation well. This well must be deep enough to penetrate the pumped aquifer, and pumping must continue for a sufficient time to ensure that depleted streamflow becomes a significant portion of the well abstraction rate. Furthermore, two of the five parameters characterize an aquitard that overlies the pumped aquifer, and values for these parameters are seen to be dependent upon the initial water table elevation in the aquitard. The field test analyzed herein used a total of eight observation wells screened in the pumped aquifer, and measurements from these wells gave eight sets of parameters that are used in a sensitivity analysis to determine the relative importance of each parameter in the stream depletion calculations. PMID:16857031

  14. Barium depletion in hollow cathode emitters

    NASA Astrophysics Data System (ADS)

    Polk, James E.; Mikellides, Ioannis G.; Capece, Angela M.; Katz, Ira

    2016-01-01

    Dispenser hollow cathodes rely on a consumable supply of Ba released by BaO-CaO-Al2O3 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.

  15. A Comprehensive Study of Interstellar Depletions

    NASA Astrophysics Data System (ADS)

    Jenkins, Edward

    2004-07-01

    We propose to analyze interstellar gas-phase abundances of Ga, Sn, Pb, B, S by measuring their absorption features in the spectra of stars observed in SNAP survey programs 8241, 8662 and 9434 {plus other programs that have had archive data released to the public}. The lines of Pb II and B II are extremely weak, so stars will be grouped into cases having different levels of general depletion and then within each category the spectra will be coadded to enhance the detectability of the lines. These data will be combined with results derived by S. Cartledge and coworkers on O and Kr, plus data soon to be published for Ge, Cu, Mg, Mn, Ni and P, in order to understand the general behavior of depletions of atoms onto dust grains under different conditions, using a new analysis technique developed by Jenkins {2003}. A better knowledge of the systematics of depletions will be beneficial to studies of the compositions of dust grains and will also aid investigations of total element abundances in distant damped L-alpha {DLA} systems seen in the spectra of quasars recorded by ground-based telescopes.

  16. Involvement of molecular oxygen in the donor-side photoinhibition of Mn-depleted photosystem II membranes.

    PubMed

    Khorobrykh, A A; Klimov, V V

    2015-12-01

    It has been shown by Khorobrykh et al. (Biochemistry (Moscow) 67:683-688, 2002); Yanykin et al. (Biochim Biophys Acta 1797:516-523, 2010); Khorobrykh et al. (Biochemistry 50:10658-10665, 2011) that Mn-depleted photosystem II (PSII) membrane fragments are characterized by an enhanced oxygen photoconsumption on the donor side of PSII which is accompanied with hydroperoxide formation and it was suggested that the events are related to the oxidative photoinhibition of PSII. Experimental confirmation of this suggestion is presented in this work. The degree of photoinhibition was determined by the loss of the capability of exogenous electron donors (Mn(2+) or sodium ascorbate) to the reactivation of electron transport [measured by the light-induced changes of chlorophyll fluorescence yield (∆F)] in Mn-depleted PSII membranes. The transition from anaerobic conditions to aerobic ones significantly activated photoinhibition of Mn-depleted PSII membranes both in the absence and in the presence of exogenous electron acceptor, ferricyanide. The photoinhibition of Mn-depleted PSII membranes was suppressed upon the addition of exogenous electron donors (Mn(2+), diphenylcarbazide, and ferrocyanide). The addition of superoxide dismutase did not affect the photoinhibition of Mn-depleted PSII membranes. It is concluded that the interaction of molecular oxygen (rather than superoxide anion radical formed on the acceptor side of PSII) with the oxidized components of the donor side of PSII reflects the involvement of O2 in the donor-side photoinhibition of Mn-depleted PSII membranes.

  17. Ab Initio Studies of Stratospheric Ozone Depletion Chemistry

    NASA Technical Reports Server (NTRS)

    Lee, Timothy J.; Head-Gordon, Martin; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    An overview of the current understanding of ozone depletion chemistry, particularly with regards the formation of the so-called Antarctic ozone hole, will be presented together with an outline as to how ab initio quantum chemistry can be used to further our understanding of stratospheric chemistry. The ability of modern state-of-the art ab initio quantum chemical techniques to characterize reliably the gas-phase molecular structure, vibrational spectrum, electronic spectrum, and thermal stability of fluorine, chlorine, bromine and nitrogen oxide species will be demonstrated by presentation of some example studies. The ab initio results will be shown to be in excellent agreement with the available experimental data, and where the experimental data are either not known or are inconclusive, the theoretical results are shown to fill in the gaps and to resolve experimental controversies. In addition, ab initio studies in which the electronic spectra and the characterization of excited electronic states of halogen oxide species will also be presented. Again where available, the ab initio results are compared to experimental observations, and are used to aid in the interpretation of experimental studies.

  18. 26 CFR 52.4682-1 - Ozone-depleting chemicals.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 17 2014-04-01 2014-04-01 false Ozone-depleting chemicals. 52.4682-1 Section 52... EXCISE TAXES (CONTINUED) ENVIRONMENTAL TAXES § 52.4682-1 Ozone-depleting chemicals. (a) Overview. This section provides rules relating to the tax imposed on ozone-depleting chemicals (ODCs) under section...

  19. 26 CFR 52.4682-1 - Ozone-depleting chemicals.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Ozone-depleting chemicals. 52.4682-1 Section 52... EXCISE TAXES (CONTINUED) ENVIRONMENTAL TAXES § 52.4682-1 Ozone-depleting chemicals. (a) Overview. This section provides rules relating to the tax imposed on ozone-depleting chemicals (ODCs) under section...

  20. 26 CFR 52.4682-1 - Ozone-depleting chemicals.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 17 2011-04-01 2011-04-01 false Ozone-depleting chemicals. 52.4682-1 Section 52... EXCISE TAXES (CONTINUED) ENVIRONMENTAL TAXES § 52.4682-1 Ozone-depleting chemicals. (a) Overview. This section provides rules relating to the tax imposed on ozone-depleting chemicals (ODCs) under section...

  1. 26 CFR 52.4682-1 - Ozone-depleting chemicals.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 17 2013-04-01 2013-04-01 false Ozone-depleting chemicals. 52.4682-1 Section 52... EXCISE TAXES (CONTINUED) ENVIRONMENTAL TAXES § 52.4682-1 Ozone-depleting chemicals. (a) Overview. This section provides rules relating to the tax imposed on ozone-depleting chemicals (ODCs) under section...

  2. 26 CFR 52.4682-1 - Ozone-depleting chemicals.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 17 2012-04-01 2012-04-01 false Ozone-depleting chemicals. 52.4682-1 Section 52... EXCISE TAXES (CONTINUED) ENVIRONMENTAL TAXES § 52.4682-1 Ozone-depleting chemicals. (a) Overview. This section provides rules relating to the tax imposed on ozone-depleting chemicals (ODCs) under section...

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

    ERIC Educational Resources Information Center

    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…

  4. 26 CFR 1.642(e)-1 - Depreciation and depletion.

    Code of Federal Regulations, 2010 CFR

    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...

  5. A modern depleted uranium manufacturing facility

    SciTech Connect

    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. Rhenium Disulfide Depletion-Load Inverter

    NASA Astrophysics Data System (ADS)

    McClellan, Connor; Corbet, Chris; Rai, Amritesh; Movva, Hema C. P.; Tutuc, Emanuel; Banerjee, Sanjay K.

    2015-03-01

    Many semiconducting Transition Metal Dichalcogenide (TMD) materials have been effectively used to create Field-Effect Transistor (FET) devices but have yet to be used in logic designs. We constructed a depletion-load voltage inverter using ultrathin layers of Rhenium Disulfide (ReS2) as the semiconducting channel. This ReS2 inverter was fabricated on a single micromechanically-exfoliated flake of ReS2. Electron beam lithography and physical vapor deposition were used to construct Cr/Au electrical contacts, an Alumina top-gate dielectric, and metal top-gate electrodes. By using both low (Aluminum) and high (Palladium) work-function metals as two separate top-gates on a single ReS2 flake, we create a dual-gated depletion mode (D-mode) and enhancement mode (E-mode) FETs in series. Both FETs displayed current saturation in the output characteristics as a result of the FET ``pinch-off'' mechanism and On/Off current ratios of 105. Field-effect mobilities of 23 and 17 cm2V-1s-1 and subthreshold swings of 97 and 551 mV/decade were calculated for the E-mode and D-mode FETs, respectively. With a supply voltage of 1V, at low/negative input voltages the inverter output was at a high logic state of 900 mV. Conversely with high/positive input voltages, the inverter output was at a low logic state of 500 mV. The inversion of the input signal demonstrates the potential for using ReS2 in future integrated circuit designs and the versatility of depletion-load logic devices for TMD research. NRI SWAN Center and ARL STTR Program.

  7. Depletion of the Outer Asteroid Belt

    NASA Technical Reports Server (NTRS)

    Liou, Jer-Chyi; Malhotra, Renu

    1997-01-01

    During the early history of the solar system, it is likely that the outer planets changed their distance from the sun, and hence, their influence on the asteroid belt evolved with time. The gravitational influence of Jupiter and Saturn on the orbital evolution of asteroids in the outer asteroid belt was calculated. The results show that the sweeping of mean motion resonances associated with planetary migration efficiently destabilizes orbits in the outer asteroid belt on a time scale of 10 million years. This mechanism provides an explanation for the observed depletion of asteroids in that region.

  8. Cognitive inflexibility after prefrontal serotonin depletion.

    PubMed

    Clarke, H F; Dalley, J W; Crofts, H S; Robbins, T W; Roberts, A C

    2004-05-01

    Serotonergic dysregulation within the prefrontal cortex (PFC) is implicated in many neuropsychiatric disorders, but the precise role of serotonin within the PFC is poorly understood. Using a serial discrimination reversal paradigm, we showed that upon reversal, selective serotonin depletion of the marmoset PFC produced perseverative responding to the previously rewarded stimulus without any significant effects on either retention of a discrimination learned preoperatively or acquisition of a novel discrimination postoperatively. These results highlight the importance of prefrontal serotonin in behavioral flexibility and are highly relevant to obsessive-compulsive disorder, schizophrenia, and the cognitive sequelae of drug abuse in which perseveration is prominent.

  9. Scientific assessment of ozone depletion: 1991

    NASA Technical Reports Server (NTRS)

    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.

  10. Correlation between cosmic rays and ozone depletion.

    PubMed

    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. PMID:19392251

  11. Ozone depletion: implications for the veterinarian.

    PubMed

    Kopecky, K E

    1978-09-15

    Man has inadvertently modified the stratosphere. There is a good possibility that the ozone layer is being depleted by the use of jet aircraft (SST), chlorofluoromethane propellants, and nitrogen fertilizers. Under unpolluted conditions, the production of ozone equals its destruction. By man's intervention, however, the destruction may exceed the production. The potential outcome is increased intensity of solar ultraviolet (280-400 nm) radiation and penetration to the earth's surface of previously absorbed wavelengths below about 280 nm. The increased ultraviolet radiation would increase the likelihood of skin cancer in man and ocular squamous cell carcinoma in cattle. The climate also might be modified, possibly in an undesirable way.

  12. Mesospheric ionization and O2 1Delta(g) depletion

    NASA Technical Reports Server (NTRS)

    Spear, K. A.; Solomon, S.

    1987-01-01

    Observations of O2 1Delta(g) emission during solar proton events reveal large depletions below 80 and near 90 km. The lower-altitude depletions are believed to be due to odd hydrogen production and associated depletion of ozone, but the mechanism producing the depletion near 90 km has not yet been established. In this paper, it is proposed that an exothermic charge exchange reaction between O2(+) and O2 1Delta(g) is likely to be responsible for these high-altitude depletions. In particular, it is shown that the vertical structure of the observed change in airglow emission is consistent with this mechanism.

  13. Imaging neurotransmitter uptake and depletion in astrocytes

    SciTech Connect

    Tan, W. |; Haydon, P.G.; Yeung, E.S.

    1997-08-01

    An ultraviolet (UV) laser-based optical microscope and charge-coupled device (CCD) detection system was used to obtain chemical images of biological cells. Subcellular structures can be easily seen in both optical and fluorescence images. Laser-induced native fluorescence detection provides high sensitivity and low limits of detection, and it does not require coupling to fluorescent dyes. We were able to quantitatively monitor serotonin that has been taken up into and released from individual astrocytes on the basis of its native fluorescence. Different regions of the cells took up different amounts of serotonin with a variety of uptake kinetics. Similarly, we observed different serotonin depletion dynamics in different astrocyte regions. There were also some astrocyte areas where no serotonin uptake or depletion was observed. Potential applications include the mapping of other biogenic species in cells as well as the ability to image their release from specific regions of cells in response to external stimuli. {copyright} {ital 1997} {ital Society for Applied Spectroscopy}

  14. Effects of diffusion on aluminum depletion and degradation of NiAl coatings

    NASA Technical Reports Server (NTRS)

    Smialek, J. L.; Lowell, C. E.

    1973-01-01

    Experiments were performed to critically demonstrate the effects of diffusion on the aluminum depletion and degradation of NiAl coatings on superalloys. Pack aluminized IN 100 and Mar-M200 were diffusion annealed in 0.0005 torr vacuum at 1100 C for 300 hours. Aluminum losses due to oxidation and vaporization were minimal. Metallographic and electron microprobe analyses showed considerable interdiffusion of the coating with the substrate, which caused a large decrease in the original aluminum level of the coating. Subsequent cyclic furnace oxidation tests were performed at 1100 C using 1 hour cycles on pre-diffused and as-coated specimens. The pre-diffusion treatment decreased the oxidation protection for both alloys, but more dramatically for IN 100. Identical oxidation tests of bulk NiAl, where such diffusion effects are precluded, showed no signs of degradation at twice the time needed to degrade the coated superalloys.

  15. Modeling Selective Intergranular Oxidation of Binary Alloys

    SciTech Connect

    Xu, Zhijie; Li, Dongsheng; Schreiber, Daniel K.; Rosso, Kevin M.; Bruemmer, Stephen M.

    2015-01-07

    Intergranular attack of alloys under hydrothermal conditions is a complex problem that depends on metal and oxygen transport kinetics via solid-state and channel-like pathways to an advancing oxidation front. Experiments reveal very different rates of intergranular attack and minor element depletion distances ahead of the oxidation front for nickel-based binary alloys depending on the minor element. For example, a significant Cr depletion up to 9 µm ahead of grain boundary crack tips were documented for Ni-5Cr binary alloy, in contrast to relatively moderate Al depletion for Ni-5Al (~100s of nm). We present a mathematical kinetics model that adapts Wagner’s model for thick film growth to intergranular attack of binary alloys. The transport coefficients of elements O, Ni, Cr, and Al in bulk alloys and along grain boundaries were estimated from the literature. For planar surface oxidation, a critical concentration of the minor element can be determined from the model where the oxide of minor element becomes dominant over the major element. This generic model for simple grain boundary oxidation can predict oxidation penetration velocities and minor element depletion distances ahead of the advancing front that are comparable to experimental data. The significant distance of depletion of Cr in Ni-5Cr in contrast to the localized Al depletion in Ni-5Al can be explained by the model due to the combination of the relatively faster diffusion of Cr along the grain boundary and slower diffusion in bulk grains, relative to Al.

  16. Modeling selective intergranular oxidation of binary alloys

    NASA Astrophysics Data System (ADS)

    Xu, Zhijie; Li, Dongsheng; Schreiber, Daniel K.; Rosso, Kevin M.; Bruemmer, Stephen M.

    2015-01-01

    Intergranular attack of alloys under hydrothermal conditions is a complex problem that depends on metal and oxygen transport kinetics via solid-state and channel-like pathways to an advancing oxidation front. Experiments reveal very different rates of intergranular attack and minor element depletion distances ahead of the oxidation front for nickel-based binary alloys depending on the minor element. For example, a significant Cr depletion up to 9 μm ahead of grain boundary crack tips was documented for Ni-5Cr binary alloy, in contrast to relatively moderate Al depletion for Ni-5Al (˜100 s of nm). We present a mathematical kinetics model that adapts Wagner's model for thick film growth to intergranular attack of binary alloys. The transport coefficients of elements O, Ni, Cr, and Al in bulk alloys and along grain boundaries were estimated from the literature. For planar surface oxidation, a critical concentration of the minor element can be determined from the model where the oxide of minor element becomes dominant over the major element. This generic model for simple grain boundary oxidation can predict oxidation penetration velocities and minor element depletion distances ahead of the advancing front that are comparable to experimental data. The significant distance of depletion of Cr in Ni-5Cr in contrast to the localized Al depletion in Ni-5Al can be explained by the model due to the combination of the relatively faster diffusion of Cr along the grain boundary and slower diffusion in bulk grains, relative to Al.

  17. Microfabrics in depleted mantle plaeotransform (New Caledonia)

    NASA Astrophysics Data System (ADS)

    Teyssier, Christian; Chatzaras, Vasileios; Von Der Handt, Anette

    2016-04-01

    The New Caledonia ophiolite contains several wrench zones that have been interpreted as paleotransforms. These transform-ridge systems developed at the transition between ridge development and intra-oceanic subduction that resulted in depleted mantle (about 18 % melt according to olivine Mg# - spinel Cr#). The most prominent is the Bogota Peninsula paleotransform, a 10 km wide shear zone in which strain localizes in the 2 km wide Ouassé mylonite zone. This strain gradient is associated with microstructure and microfabric evolution that informs the relationship between hydration and strain in mantle mylonite. Olivine recrystallized grain size varies from about 1 mm to about 0.2 mm toward the mylonite zone. The strain gradient is also demonstrated by increasing deformation of orthopyroxene (opx) grains that become elongate porphyroclasts in the mylonite zone. Orthopyroxene geothermometry reveals T ~ 1050-1000 C (Ca-opx) and 950-850 C (Cr-Al-opx) in the least deformed rocks. In the mylonite zone a wider range of T is recorded, with minima reaching 850 C (Ca-opx) and 750 C (Cr-Al-opx). Electron microprobe analysis also detects the presence of 20-200 micron interstitial, high-temperature amphibole (pargasite), with modal abundance increasing in the mylonite zone; this suggests that high-temperature pervasive fluid flow may have played a role in strain localization and mylonitization. Olivine crystallographic fabrics include A-type and E-type, the latter possibly reflecting hydration of shear zone tectonites. E-type fabrics are present in both mylonite and less deformed rocks, and appear to be more common in rocks with olivine grain size < 400 microns. A correlation between E-type fabrics and amphibole mode is being investigated. The shear zone protolith was depleted mantle in which the ridge-transform system was permeated by fluids. These fluids initially originated at the subduction interface, but during the transform evolution, ocean water likely permeated the shear

  18. OXYGEN DEPLETION IN THE INTERSTELLAR MEDIUM: IMPLICATIONS FOR GRAIN MODELS AND THE DISTRIBUTION OF ELEMENTAL OXYGEN

    SciTech Connect

    Whittet, D. C. B.

    2010-02-20

    This paper assesses the implications of a recent discovery 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 (n{sub H}). At the interface between diffuse and dense phases (just before the onset of ice-mantle growth) as much as {approx}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 carriers, the most plausible appears to be a form of O-bearing carbonaceous matter similar to the organics found in cometary particles returned by the Stardust mission. The 'organic refractory' model for interstellar dust is re-examined in the light of these findings, and it is concluded that further observations and laboratory work are needed to determine whether this class of material is present in quantities sufficient to account for a significant fraction of the unidentified depleted oxygen.

  19. Gaseous elemental mercury depletion events observed at Cape Point during 2007-2008

    NASA Astrophysics Data System (ADS)

    Brunke, E.-G.; Labuschagne, C.; Ebinghaus, R.; Kock, H. H.; Slemr, F.

    2010-02-01

    Gaseous mercury in the marine boundary layer has been measured with a 15 min temporal resolution at the Global Atmosphere Watch station Cape Point since March 2007. The most prominent features of the data until July 2008 are the frequent occurrences of pollution (PEs) and depletion events (DEs). Both types of events originate mostly within a short transport distance (up to about 100 km), which are embedded in air masses ranging from marine background to continental. The Hg/CO emission ratios observed during the PEs are within the range reported for biomass burning and industrial/urban emissions. The depletion of gaseous mercury during the DEs is in many cases almost complete and suggests an atmospheric residence time of elemental mercury as short as a few dozens of hours, which is in contrast to the commonly used estimate of approximately 1 year. The DEs observed at Cape Point are not accompanied by simultaneous depletion of ozone which distinguishes them from the halogen driven atmospheric mercury depletion events (AMDEs) observed in Polar Regions. Nonetheless, DEs similar to those observed at Cape Point have also been observed at other places in the marine boundary layer. Additional measurements of mercury speciation and of possible mercury oxidants are hence called for to reveal the chemical mechanism of the newly observed DEs and to assess its importance on larger scales.

  20. Mitochondrial ATP transporter Ant2 depletion impairs erythropoiesis and B lymphopoiesis

    PubMed Central

    Cho, J; Seo, J; Lim, C H; Yang, L; Shiratsuchi, T; Lee, M-H; Chowdhury, R R; Kasahara, H; Kim, J-S; Oh, S P; Lee, Y J; Terada, N

    2015-01-01

    Adenine nucleotide translocases (ANTs) transport ADP and ATP through mitochondrial inner membrane, thus playing an essential role for energy metabolism of eukaryotic cells. Mice have three ANT paralogs, Ant1 (Slc25a4), Ant2 (Slc25a5) and Ant4 (Slc25a31), which are expressed in a tissue-dependent manner. While knockout mice have been characterized with Ant1 and Ant4 genes, which resulted in exercise intolerance and male infertility, respectively, the role of the ubiquitously expressed Ant2 gene in animal development has not been fully demonstrated. Here, we generated Ant2 hypomorphic mice by targeted disruption of the gene, in which Ant2 expression is largely depleted. The mice showed apparently normal embryonic development except pale phenotype along with a reduced birth rate. However, postnatal growth was severely retarded with macrocytic anemia, B lymphocytopenia, lactic acidosis and bloated stomach, and died within 4 weeks. Ant2 depletion caused anemia in a cell-autonomous manner by maturation arrest of erythroid precursors with increased reactive oxygen species and premature deaths. B-lymphocyte development was similarly affected by Ant2 depletion, and splenocytes showed a reduction in maximal respiration capacity and cellular ATP levels as well as an increase in cell death accompanying mitochondrial permeability transition pore opening. In contrast, myeloid, megakaryocyte and T-lymphocyte lineages remained apparently intact. Erythroid and B-cell development may be particularly vulnerable to Ant2 depletion-mediated mitochondrial dysfunction and oxidative stress. PMID:25613378

  1. Mitochondrial ATP transporter Ant2 depletion impairs erythropoiesis and B lymphopoiesis.

    PubMed

    Cho, J; Seo, J; Lim, C H; Yang, L; Shiratsuchi, T; Lee, M-H; Chowdhury, R R; Kasahara, H; Kim, J-S; Oh, S P; Lee, Y J; Terada, N

    2015-09-01

    Adenine nucleotide translocases (ANTs) transport ADP and ATP through mitochondrial inner membrane, thus playing an essential role for energy metabolism of eukaryotic cells. Mice have three ANT paralogs, Ant1 (Slc25a4), Ant2 (Slc25a5) and Ant4 (Slc25a31), which are expressed in a tissue-dependent manner. While knockout mice have been characterized with Ant1 and Ant4 genes, which resulted in exercise intolerance and male infertility, respectively, the role of the ubiquitously expressed Ant2 gene in animal development has not been fully demonstrated. Here, we generated Ant2 hypomorphic mice by targeted disruption of the gene, in which Ant2 expression is largely depleted. The mice showed apparently normal embryonic development except pale phenotype along with a reduced birth rate. However, postnatal growth was severely retarded with macrocytic anemia, B lymphocytopenia, lactic acidosis and bloated stomach, and died within 4 weeks. Ant2 depletion caused anemia in a cell-autonomous manner by maturation arrest of erythroid precursors with increased reactive oxygen species and premature deaths. B-lymphocyte development was similarly affected by Ant2 depletion, and splenocytes showed a reduction in maximal respiration capacity and cellular ATP levels as well as an increase in cell death accompanying mitochondrial permeability transition pore opening. In contrast, myeloid, megakaryocyte and T-lymphocyte lineages remained apparently intact. Erythroid and B-cell development may be particularly vulnerable to Ant2 depletion-mediated mitochondrial dysfunction and oxidative stress. PMID:25613378

  2. Depleted uranium waste assay at AWE

    SciTech Connect

    Miller, T.J.

    2007-07-01

    The Atomic Weapons Establishment (AWE) at Aldermaston has recently conducted a Best Practical Means (BPM) study, for solid Depleted Uranium (DU) waste assay, in order to satisfy key stakeholders that AWE is applying best practice. This study has identified portable passive High Resolution Gamma Spectrometry (HRGS), combined with an analytical software package called Spectral Nondestructive Assay Platform (SNAP), as the preferred option with the best balance between performance and costs. HRGS/SNAP performance has been assessed by monitoring 200 l DU waste drum standards and also heterogeneous, high density drums from DU firing trials. Accuracy was usually within 30 % with Detection Limits (DL) in the region of 10 g DU for short count times. Monte Carlo N-Particle (MCNP) calculations have been used to confirm the shape of the calibration curve generated by the SNAP software procured from Eberline Services Inc. (authors)

  3. Health effects of embedded depleted uranium.

    PubMed

    McClain, David E; Benson, Kimberly A; Dalton, Tom K; Ejnik, John; Emond, Christy A; Hodge, Shelly J; Kalinich, John F; Landauer, Michael R; Livengood, David R; Miller, Alexandra C; Pellmar, Terry C; Stewart, Michael D; Villa, Vilmar; Xu, Jiaquan

    2002-02-01

    The health effects of embedded fragments of depleted uranium (DU) are being investigated to determine whether current surgical fragment-removal policies are appropriate for this metal. The authors studied rodents implanted with DU pellets as well as cultured human cells exposed to DU compounds. Results indicate that uranium from implanted DU fragments distributes to tissues distant from implantation sites, including bone, kidney, muscle, and liver. Despite levels of uranium in kidney that would be nephrotoxic after acute exposure, no histological or functional kidney toxicity was observed with embedded DU, indicating that the kidney adapts when exposed chronically. Nonetheless, further studies of the long-term health impact are needed. DU is mutagenic and transforms human osteoblastic cells into a tumorigenic phenotype. It alters neurophysiological parameters in rat hippocampus, crosses the placental barrier, and enters fetal tissue. Preliminary data also indicate decreased rodent litter size when animals are bred 6 months or longer after DU implantation. PMID:11873491

  4. Arctic Ozone Depletion from UARS MLS Measurements

    NASA Technical Reports Server (NTRS)

    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.

  5. Anxiety, ego depletion, and sports performance.

    PubMed

    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.

  6. Modelling chemical depletion profiles in regolith

    USGS Publications Warehouse

    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.

  7. Development of DU-AGG (Depleted Uranium Aggregate)

    SciTech Connect

    Lessing, P.A.

    1995-09-01

    Depleted uranium oxide (UO{sub 2} or U0{sub 3}) powder was mixed with fine mineral additives, pressed, and heated to about 1,250{degree}C. The additives were chemically constituted to result in an iron-enriched basalt (IEB). Melting and wetting of the IEB phase caused the urania powder compact to densify (sinter) via a liquid phase sintering mechanism. An inorganic lubricant was found to aid in green-forming of the body. Sintering was successful in oxidizing (air), inert (argon), or reducing (dry hydrogen containing) atmospheres. The use of ground U0{sub 3} powders (93 vol %) followed by sintering in a dry hydrogen-containing atmosphere significantly increased the density of samples (bulk density of 8.40 g/cm{sup 3} and apparent density of 9.48 g/cm{sup 3}, open porosity of 11.43%). An improvement in the microstructure (reduction in open porosity) was achieved when the vol % of U0{sub 3} was decreased to 80%. The bulk density increased to 8.59 g/cm{sup 3}, the apparent density decreased slightly to 8.82 g/cm{sup 3} (due to increase of low density IEB content), while the open porosity decreased to an excellent number of 2.78%. A representative sample derived from 80 vol % U0{sub 3} showed that most pores were closed pores and that, overall, the sample achieved the excellent relative density value of 94.1% of the estimated theoretical density (composite of U0{sub 2} and IEB). It is expected that ground powders of U0{sub 3} could be successfully used to mass produce lowcost aggregate using the green-forming technique of briquetting.

  8. Allyl isothiocyanate depletes glutathione and upregulates expression of glutathione S-transferases in Arabidopsis thaliana

    PubMed Central

    Øverby, Anders; Stokland, Ragni A.; Åsberg, Signe E.; Sporsheim, Bjørnar; Bones, Atle M.

    2015-01-01

    Allyl isothiocyanate (AITC) is a phytochemical associated with plant defense in plants from the Brassicaceae family. AITC has long been recognized as a countermeasure against external threats, but recent reports suggest that AITC is also involved in the onset of defense-related mechanisms such as the regulation of stomatal aperture. However, the underlying cellular modes of action in plants remain scarcely investigated. Here we report evidence of an AITC-induced depletion of glutathione (GSH) and the effect on gene expression of the detoxification enzyme family glutathione S-transferases (GSTs) in Arabidopsis thaliana. Treatment of A. thaliana wild-type with AITC resulted in a time- and dose-dependent depletion of cellular GSH. AITC-exposure of mutant lines vtc1 and pad2-1 with elevated and reduced GSH-levels, displayed enhanced and decreased AITC-tolerance, respectively. AITC-exposure also led to increased ROS-levels in the roots and loss of chlorophyll which are symptoms of oxidative stress. Following exposure to AITC, we found that GSH rapidly recovered to the same level as in the control plant, suggesting an effective route for replenishment of GSH or a rapid detoxification of AITC. Transcriptional analysis of genes encoding GSTs showed an upregulation in response to AITC. These findings demonstrate cellular effects by AITC involving a reversible depletion of the GSH-pool, induced oxidative stress, and elevated expression of GST-encoding genes. PMID:25954298

  9. The changing ozone depletion potential of N2O in a future climate

    NASA Astrophysics Data System (ADS)

    Revell, L. E.; Tummon, F.; Salawitch, R. J.; Stenke, A.; Peter, T.

    2015-11-01

    Nitrous oxide (N2O), which decomposes in the stratosphere to form nitrogen oxides (NOx), is currently the dominant anthropogenic ozone-depleting substance emitted. Ozone depletion potentials (ODPs) of specific compounds, commonly evaluated for present-day conditions, were developed for long-lived halocarbons and are used by policymakers to inform decision-making around protection of the ozone layer. However, the effect of N2O on ozone will evolve in the future due to changes in stratospheric dynamics and chemistry induced by rising levels of greenhouse gases. Despite the fact that NOx-induced ozone loss slows with increasing concentrations of CO2 and CH4, we show that ODPN2O for year 2100 varies under different scenarios and is mostly larger than ODPN2O for year 2000. This occurs because the traditional ODP approach is tied to ozone depletion induced by CFC-11, which is also sensitive to CO2 and CH4. We therefore suggest that a single ODP for N2O is of limited use.

  10. Measurement of thermal diffusivity of depleted uranium metal microspheres

    NASA Astrophysics Data System (ADS)

    Humrickhouse-Helmreich, Carissa J.; Corbin, Rob; McDeavitt, Sean M.

    2014-03-01

    The high void space of nuclear fuels composed of homogeneous uranium metal microspheres may allow them to achieve ultra-high burnup by accommodating fuel swelling and reducing fuel/cladding interactions; however, the relatively low thermal conductivity of microsphere nuclear fuels may limit their application. To support the development of microsphere nuclear fuels, an apparatus was designed in a glovebox and used to measure the apparent thermal diffusivity of a packed bed of depleted uranium (DU) microspheres with argon fill in the void spaces. The developed Crucible Heater Test Assembly (CHTA) recorded radial temperature changes due to an initial heat pulse from a central thin-diameter cartridge heater. Using thermocouple positions and time-temperature data, the apparent thermal diffusivity was calculated. The thermal conductivity of the DU microspheres was calculated based on the thermal diffusivity from the CHTA, known material densities and specific heat capacities, and an assumed 70% packing density based on prior measurements. Results indicate that DU metal microspheres have very low thermal conductivity, relative to solid uranium metal, and rapidly form an oxidation layer even in a low oxygen environment. At 500 °C, the thermal conductivity of the DU metal microsphere bed was 0.431 ± 0.0560 W/m-K compared to the literature value of approximately 32 W/m-K for solid uranium metal.

  11. Depletion in Antarctic ozone and associated climatic change

    SciTech Connect

    Lal, M.

    1992-03-01

    Perhaps the most significant discovery in the atmospheric sciences in the last decade has been the observation of large decreases in ozone. These losses in ozone occur during austral spring, and from 1979 the severity of the depletion increased non-monotonically until September of 1987 when the lowest column ozone amounts ever recorded were observed in Antarctica. While the surprising ozone hole in the remote icy continent of Antarctica emphasizes the potential importance and complexity of processes in the high latitude stratosphere, it also motivated this study on the nature of greenhouse effect on polar climate due to perturbations in column ozone amount in association with observed increases in other trace gases in the Antarctic atmosphere. The authors have examined the potential climatic effects of changes in the concentration of greenhouse gases on thermal structure of the Antarctic atmosphere using both steady-state and time-dependent climate models. When they incorporate the greenhouse effect of increases in methane, nitrous oxide, carbon dioxide and chlorofluorocarbons in association with decrease in ozone at the levels of maximum concentration in the radiative flux computations for the Antarctic region, the net result is a surface warming which is in fair agreement with that inferred from mean Antarctic temperature series.

  12. Transpassive electrodissolution of depleted uranium in alkaline electrolytes

    SciTech Connect

    Weisbrod, K.R.; Schake, A.R.; Morgan, A.N.; Purdy, G.M.; Martinez, H.E.; Nelson, T.O.

    1998-03-01

    To aid in removal of oralloy from the nuclear weapons stockpile, scientists at the Los Alamos National Laboratory Plutonium Facility are decontaminating oralloy parts by electrodissolution in neutral to alkaline electrolytes composed of sodium nitrate and sodium sulfate. To improve the process, electrodissolution experiments were performed with depleted uranium to understand the effects of various operating parameters. Sufficient precipitate was also produced to evaluate the feasibility of using ultrafiltration to separate the uranium oxide precipitates from the electrolyte before it enters the decontamination fixture. In preparation for the experiments, a potential-pH diagram for uranium was constructed from thermodynamic data for fully hydrated species. Electrodissolution in unstirred solutions showed that uranium dissolution forms two layers, an acidic bottom layer rich in uranium and an alkaline upper layer. Under stirred conditions results are consistent with the formation of a yellow precipitate of composition UO{sub 3}{center_dot}2H{sub 2}O, a six electron process. Amperometric experiments showed that current efficiency remained near 100% over a wide range of electrolytes, electrolyte concentrations, pH, and stirring conditions.

  13. Brief mindfulness induction could reduce aggression after depletion.

    PubMed

    Yusainy, Cleoputri; Lawrence, Claire

    2015-05-01

    Many experiments have shown that one's ability to refrain from acting on aggressive impulses is likely to decrease following a prior act of self-control. This temporary state of self-control failure is known as ego-depletion. Although mindfulness is increasingly used to treat and manage aggressive behaviour, the extent to which mindfulness may counteract the depletion effect on aggression is yet to be determined. This study (N=110) investigated the effect of a laboratory induced one-time mindfulness meditation session on aggression following depletion. Aggression was assessed by the intensity of aversive noise blast participants delivered to an opponent on a computerised task. Depleted participants who received mindfulness induction behaved less aggressively than depleted participants with no mindfulness induction. Mindfulness also improved performance on a second measure of self-control (i.e., handgrip perseverance); however, this effect was independent of depletion condition. Motivational factors may help explain the dynamics of mindfulness, self-control, and aggression.

  14. Failure to Replicate Depletion of Self-Control

    PubMed Central

    Xu, Xiaomeng; Demos, Kathryn E.; Leahey, Tricia M.; Hart, Chantelle N.; Trautvetter, Jennifer; Coward, Pamela; Middleton, Kathryn R.; Wing, Rena R.

    2014-01-01

    The limited resource or strength model of self-control posits that the use of self-regulatory resources leads to depletion and poorer performance on subsequent self-control tasks. We conducted four studies (two with community samples, two with young adult samples) utilizing a frequently used depletion procedure (crossing out letters protocol) and the two most frequently used dependent measures of self-control (handgrip perseverance and modified Stroop). In each study, participants completed a baseline self-control measure, a depletion or control task (randomized), and then the same measure of self-control a second time. There was no evidence for significant depletion effects in any of these four studies. The null results obtained in four attempts to replicate using strong methodological approaches may indicate that depletion has more limited effects than implied by prior publications. We encourage further efforts to replicate depletion (particularly among community samples) with full disclosure of positive and negative results. PMID:25333564

  15. Groundwater depletion in the United States (1900−2008)

    USGS Publications Warehouse

    Konikow, Leonard F.

    2013-01-01

    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 United States are not well characterized. This study evaluates long-term cumulative depletion volumes in 40 separate aquifers or areas and one land use category in the United States, bringing together information from the literature and from new analyses. Depletion is directly calculated using calibrated groundwater models, analytical approaches, or volumetric budget analyses for multiple aquifer systems. Estimated groundwater depletion in the United States during 1900–2008 totals approximately 1,000 cubic kilometers (km3). Furthermore, the rate of groundwater depletion has increased markedly since about 1950, with maximum rates occurring during the most recent period (2000–2008) when the depletion rate averaged almost 25 km3 per year (compared to 9.2 km3 per year averaged over the 1900–2008 timeframe).

  16. Using depletion to control colloidal crystal assemblies of hard cuboctahedra.

    PubMed

    Karas, Andrew S; Glaser, Jens; Glotzer, Sharon C

    2016-06-21

    Depletion interactions arise from entropic forces, and their ability to induce aggregation and even ordering of colloidal particles through self-assembly is well established, especially for spherical colloids. We vary the size and concentration of penetrable hard sphere depletants in a system of cuboctahedra, and we show how depletion changes the preferential facet alignment of the colloids and thereby selects different crystal structures. Moreover, we explain the cuboctahedra phase behavior using perturbative free energy calculations. We find that cuboctahedra can form a stable simple cubic phase, and, remarkably, that the stability of this phase can be rationalized only by considering the effects of both the colloid and depletant entropy. We corroborate our results by analyzing how the depletant concentration and size affect the emergent directional entropic forces and hence the effective particle shape. We propose the use of depletants as a means of easily changing the effective shape of self-assembling anisotropic colloids. PMID:27194463

  17. Thalidomide modulates nuclear redox status and preferentially depletes glutathione in rabbit limb versus rat limb.

    PubMed

    Hansen, Jason M; Harris, Katie K; Philbert, Martin A; Harris, Craig

    2002-03-01

    Thalidomide produces numerous birth defects, the most notable being phocomelia. Mechanisms behind thalidomide-induced malformations have not been fully elucidated, although recent evidence suggests a role for reactive oxygen species. A thalidomide-resistant (rat) and -sensitive (rabbit) species were used to compare potential inherent differences related to oxidative stress that may provide a more definitive understanding of mechanisms of thalidomide embryopathy. Limb bud cells (LBCs) were removed from the rat and rabbit embryo, dissociated, and plated in culture for 24 h. A fluorescence (6-carboxy-2',7'-dichlorofluorescin diacetate; DCF) assay for oxidative stress was used with varying concentrations of thalidomide (5-100 microM). Thalidomide (100 microM) showed a 6-fold greater production of oxidative stress in rabbit cultures than in rat. Lower concentrations (50 and 25 microM) also showed a significant increase in reactive oxygen species. Confocal microscopy revealed DCF fluorescence preferentially in rabbit LBC nuclei compared with the uniform distribution of DCF fluorescence in rat LBC. Localization of glutathione (GSH) was determined using 5-chloromethylfluorescein diacetate fluorescent confocal microscopy. In rat cultures, significant thalidomide-induced GSH depletion was detected in the cytosol but the nuclei maintained its GSH content, but rabbit LBC showed significant GSH depletion in both compartments. GSH depletion was confirmed by high-performance liquid chromatography analysis. These observations provide evidence that thalidomide preferentially produces oxidative stress in the thalidomide-sensitive species but not the thalidomide-resistant species. Nuclear GSH content in the rabbit LBC is selectively modified and indicates a shift in the nuclear redox environment. Redox shifts in the nucleus may result in the misregulation of transcription factor/DNA interactions and cause defective growth and development.

  18. Depletion of NADP(H) due to CD38 activation triggers endothelial dysfunction in the postischemic heart.

    PubMed

    Reyes, Levy A; Boslett, James; Varadharaj, Saradhadevi; De Pascali, Francesco; Hemann, Craig; Druhan, Lawrence J; Ambrosio, Giuseppe; El-Mahdy, Mohamed; Zweier, Jay L

    2015-09-15

    In the postischemic heart, coronary vasodilation is impaired due to loss of endothelial nitric oxide synthase (eNOS) function. Although the eNOS cofactor tetrahydrobiopterin (BH4) is depleted, its repletion only partially restores eNOS-mediated coronary vasodilation, indicating that other critical factors trigger endothelial dysfunction. Therefore, studies were performed to characterize the unidentified factor(s) that trigger endothelial dysfunction in the postischemic heart. We observed that depletion of the eNOS substrate NADPH occurs in the postischemic heart with near total depletion from the endothelium, triggering impaired eNOS function and limiting BH4 rescue through NADPH-dependent salvage pathways. In isolated rat hearts subjected to 30 min of ischemia and reperfusion (I/R), depletion of the NADP(H) pool occurred and was most marked in the endothelium, with >85% depletion. Repletion of NADPH after I/R increased NOS-dependent coronary flow well above that with BH4 alone. With combined NADPH and BH4 repletion, full restoration of NOS-dependent coronary flow occurred. Profound endothelial NADPH depletion was identified to be due to marked activation of the NAD(P)ase-activity of CD38 and could be prevented by inhibition or specific knockdown of this protein. Depletion of the NADPH precursor, NADP(+), coincided with formation of 2'-phospho-ADP ribose, a CD38-derived signaling molecule. Inhibition of CD38 prevented NADP(H) depletion and preserved endothelium-dependent relaxation and NO generation with increased recovery of contractile function and decreased infarction in the postischemic heart. Thus, CD38 activation is an important cause of postischemic endothelial dysfunction and presents a novel therapeutic target for prevention of this dysfunction in unstable coronary syndromes.

  19. Depletion theory and the precipitation of protein by polymer.

    PubMed

    Odijk, Theo

    2009-03-26

    The depletion theory of nanoparticles immersed in a semidilute polymer solution is reinterpreted in terms of depleted chains of polymer segments. Limitations and extensions of mean-field and scaling theories are discussed. An explicit expression for the interaction between two small spheres is also reviewed. The depletion free energy for a particle of general shape is given in terms of the capacitance or effective Stokes radius. This affords a reasonable explanation for the effect of polymer on protein precipitation.

  20. Cold blast furnace syndrome: a new source of toxic inhalation by nitrogen oxides

    PubMed Central

    Tague, I; Llewellin, P; Burton, K; Buchan, R; Yates, D

    2004-01-01

    Methods: Fourteen workers developed acute respiratory symptoms shortly after exposure to "air blast" from blast furnace tuyeres. These included chest tightness, dyspnoea, rigors, and diaphoresis. Chest radiographs showed pulmonary infiltrates, and lung function a restrictive abnormality. This report includes a description of clinical features of the affected workers and elucidation of the probable cause of the outbreak. Results: Clinical features and occupational hygiene measurements suggested the most likely cause was inhalation of nitrogen oxides at high pressure and temperature. While the task could not be eliminated, engineering controls were implemented to control the hazard. No further cases have occurred. Conclusions: "Cold blast furnace syndrome" represents a previously undescribed hazard of blast furnace work, probably due to inhalation of nitrogen oxides. It should be considered in the differential diagnosis of acute toxic inhalational injuries in blast furnace workers. PMID:15090669

  1. ELEMENTAL DEPLETIONS IN THE MAGELLANIC CLOUDS AND THE EVOLUTION OF DEPLETIONS WITH METALLICITY

    SciTech Connect

    Tchernyshyov, Kirill; Meixner, Margaret; Seale, Jonathan; Fox, Andrew; Friedman, Scott D.; Dwek, Eli; Galliano, Frédéric

    2015-10-01

    We present a study of the composition of gas and dust in the Large and Small Magellanic Clouds (LMC and SMC) using UV absorption spectroscopy. We measure P ii and Fe ii along 84 spatially distributed sightlines toward the MCs using archival Far Ultraviolet Spectroscopic Explorer observations. For 16 of those sightlines, we also measure Si ii, Cr ii, and Zn ii from new Hubble Space Telescope Cosmic Origins Spectrograph observations. We analyze these spectra using a new spectral line analysis technique based on a semi-parametric Voigt profile model. We have combined these measurements with H i and H{sub 2} column densities and reference stellar abundances from the literature to derive gas-phase abundances, depletions, and gas-to-dust ratios (GDRs). Of our 84 P and 16 Zn measurements, 80 and 13, respectively, are depleted by more than 0.1 dex, suggesting that P and Zn abundances are not accurate metallicity indicators at and above the metallicity of the SMC. Si, Cr, and Fe are systematically less depleted in the SMC than in the Milky Way (MW) or LMC. The minimum Si depletion in the SMC is consistent with zero. We find GDR ranges of 190–565 in the LMC and 480–2100 in the SMC, which is broadly consistent with GDRs from the literature. These ranges represent actual location to location variation and are evidence of dust destruction and/or growth in the diffuse neutral phase of the interstellar medium. Where they overlap in metallicity, the gas-phase abundances of the MW, LMC, and SMC and damped Lyα systems evolve similarly with metallicity.

  2. Elemental Depletions in the Magellanic Clouds and the Evolution of Depletions with Metallicity

    NASA Astrophysics Data System (ADS)

    Tchernyshyov, Kirill; Meixner, Margaret; Seale, Jonathan; Fox, Andrew; Friedman, Scott D.; Dwek, Eli; Galliano, Frédéric

    2015-10-01

    We present a study of the composition of gas and dust in the Large and Small Magellanic Clouds (LMC and SMC) using UV absorption spectroscopy. We measure P ii and Fe ii along 84 spatially distributed sightlines toward the MCs using archival Far Ultraviolet Spectroscopic Explorer observations. For 16 of those sightlines, we also measure Si ii, Cr ii, and Zn ii from new Hubble Space Telescope Cosmic Origins Spectrograph observations. We analyze these spectra using a new spectral line analysis technique based on a semi-parametric Voigt profile model. We have combined these measurements with H i and H2 column densities and reference stellar abundances from the literature to derive gas-phase abundances, depletions, and gas-to-dust ratios (GDRs). Of our 84 P and 16 Zn measurements, 80 and 13, respectively, are depleted by more than 0.1 dex, suggesting that P and Zn abundances are not accurate metallicity indicators at and above the metallicity of the SMC. Si, Cr, and Fe are systematically less depleted in the SMC than in the Milky Way (MW) or LMC. The minimum Si depletion in the SMC is consistent with zero. We find GDR ranges of 190-565 in the LMC and 480-2100 in the SMC, which is broadly consistent with GDRs from the literature. These ranges represent actual location to location variation and are evidence of dust destruction and/or growth in the diffuse neutral phase of the interstellar medium. Where they overlap in metallicity, the gas-phase abundances of the MW, LMC, and SMC and damped Lyα systems evolve similarly with metallicity.

  3. C18O Depletion in Starless Cores in Taurus

    NASA Astrophysics Data System (ADS)

    Ford, Amanda Brady; Shirley, Yancy L.

    2011-02-01

    We present here findings for C18O depletion in eight starless cores in Taurus: TMC-2, L1498, L1512, L1489, L1517B, L1521E, L1495A-S, and L1544. We compare observations of the C18O J = 2-1 transition taken with the ALMA prototype receiver on the Heinrich Hertz Submillimeter Telescope to results of radiative transfer modeling using RATRAN. We use temperature and density profiles calculated from dust continuum radiative transfer models to model the C18O emission. We present modeling of three cores, TMC-2, L1489, and L1495A-S, which have not been modeled before, and compare our results for the five cores with published models. We find that all of the cores but one, L1521E, are substantially depleted. We also find that varying the temperature profiles of these model cores has a discernable effect, and varying the central density has an even larger effect. We find no trends with depletion radius or depletion fraction with the density or temperature of these cores, suggesting that the physical structure alone is insufficient to fully constrain evolutionary state. We are able to place tighter constraints on the radius at which C18O is depleted than the absolute fraction of depletion. As the timeline of chemical depletion depends sensitively on the fraction of depletion, this difficulty in constraining depletion fraction makes comparison with other timescales, such as the free-fall timescale, very difficult.

  4. Regret causes ego-depletion and finding benefits in the regrettable events alleviates ego-depletion.

    PubMed

    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. PMID:24940811

  5. Characterization and speciation of depleted uranium in individual soil particles using microanalytical methods

    NASA Astrophysics Data System (ADS)

    Török, S.; Osán, J.; Vincze, L.; Kurunczi, S.; Tamborini, G.; Betti, M.

    2004-05-01

    Microanalytical techniques for elemental composition and nuclide-specific analysis have been used to identify the origin and the leachability of depleted uranium particles. The soil particle samples were collected from Kosovo area a few years after the war, the presence of fine particles with depleted uranium as major component was easily identified by EPMA and SIMS. The ultrafine uranium particles were often attached to larger soil particles and contained Ti and Al, being typical components of the penetrator and its cladding. The oxidation state of uranium in the single particles was measured by micro-XANES and found to be in the less soluble form IV while every particle contained a small fraction of mobile uranium VI as well.

  6. Sedimentary constraints on the duration of the Marinoan Oxygen-17 Depletion (MOSD) event.

    PubMed

    Killingsworth, Bryan A; Hayles, Justin A; Zhou, Chuanming; Bao, Huiming

    2013-10-29

    The ~635 Ma Marinoan glaciation is marked by dramatic Earth system perturbations. Deposition of nonmass-dependently (17)O-depleted sulfate (SO4(2-)) in worldwide postglacial sediments is, thus far, unique to this glaciation. It is proposed that an extremely high-pCO2 atmosphere can result in highly (17)O-depleted atmospheric O2, or the Marinoan Oxygen-17 Depletion (MOSD) event. This anomalous (17)O signal was imparted to sulfate of oxidative weathering origin. However, (17)O-depleted sulfate occurs in limited sedimentary intervals, suggesting that Earth surface conditions conducive to the MOSD had a finite duration. An MOSD duration can, therefore, provide much needed constraint on modeling Earth system responses at that time. Unfortunately, the sulfate (17)O record is often sparse or lacks radiometric dates. Here, we report 11 barite layers from a post-Marinoan dolostone sequence at Wushanhu in the South China Block. The (17)O depletion fluctuates in magnitude in lower layers but is persistently absent up section, providing the most confident first and last sedimentary appearance of the anomaly. δ(13)C chemostratigraphy is used to correlate the Wushanhu section to two proximal sections on the same shallow platform that lack barite layers but have published U-Pb dates that occur in dolostone and shale. Assuming a similar pattern and rate for carbonate and shale deposition among the different sections, we estimate the MOSD duration at 0-0.99 My. This number can be further constrained by new radiometric dates from equivalent sequences worldwide, thus underpinning models on the nonsteady-state Earth system response in the immediate aftermath of the Marinoan meltdown. PMID:23386719

  7. Sedimentary constraints on the duration of the Marinoan Oxygen-17 Depletion (MOSD) event

    PubMed Central

    Killingsworth, Bryan A.; Hayles, Justin A.; Zhou, Chuanming; Bao, Huiming

    2013-01-01

    The ∼635 Ma Marinoan glaciation is marked by dramatic Earth system perturbations. Deposition of nonmass-dependently 17O-depleted sulfate (SO42−) in worldwide postglacial sediments is, thus far, unique to this glaciation. It is proposed that an extremely high-pCO2 atmosphere can result in highly 17O-depleted atmospheric O2, or the Marinoan Oxygen-17 Depletion (MOSD) event. This anomalous 17O signal was imparted to sulfate of oxidative weathering origin. However, 17O-depleted sulfate occurs in limited sedimentary intervals, suggesting that Earth surface conditions conducive to the MOSD had a finite duration. An MOSD duration can, therefore, provide much needed constraint on modeling Earth system responses at that time. Unfortunately, the sulfate 17O record is often sparse or lacks radiometric dates. Here, we report 11 barite layers from a post-Marinoan dolostone sequence at Wushanhu in the South China Block. The 17O depletion fluctuates in magnitude in lower layers but is persistently absent up section, providing the most confident first and last sedimentary appearance of the anomaly. δ13C chemostratigraphy is used to correlate the Wushanhu section to two proximal sections on the same shallow platform that lack barite layers but have published U-Pb dates that occur in dolostone and shale. Assuming a similar pattern and rate for carbonate and shale deposition among the different sections, we estimate the MOSD duration at 0–0.99 My. This number can be further constrained by new radiometric dates from equivalent sequences worldwide, thus underpinning models on the nonsteady-state Earth system response in the immediate aftermath of the Marinoan meltdown. PMID:23386719

  8. Sedimentary constraints on the duration of the Marinoan Oxygen-17 Depletion (MOSD) event

    NASA Astrophysics Data System (ADS)

    Killingsworth, Bryan A.; Hayles, Justin A.; Zhou, Chuanming; Bao, Huiming

    2013-10-01

    The ∼635 Ma Marinoan glaciation is marked by dramatic Earth system perturbations. Deposition of nonmass-dependently 17O-depleted sulfate (SO42-) in worldwide postglacial sediments is, thus far, unique to this glaciation. It is proposed that an extremely high-pCO2 atmosphere can result in highly 17O-depleted atmospheric O2, or the Marinoan Oxygen-17 Depletion (MOSD) event. This anomalous 17O signal was imparted to sulfate of oxidative weathering origin. However, 17O-depleted sulfate occurs in limited sedimentary intervals, suggesting that Earth surface conditions conducive to the MOSD had a finite duration. An MOSD duration can, therefore, provide much needed constraint on modeling Earth system responses at that time. Unfortunately, the sulfate 17O record is often sparse or lacks radiometric dates. Here, we report 11 barite layers from a post-Marinoan dolostone sequence at Wushanhu in the South China Block. The 17O depletion fluctuates in magnitude in lower layers but is persistently absent up section, providing the most confident first and last sedimentary appearance of the anomaly. δ13C chemostratigraphy is used to correlate the Wushanhu section to two proximal sections on the same shallow platform that lack barite layers but have published U-Pb dates that occur in dolostone and shale. Assuming a similar pattern and rate for carbonate and shale deposition among the different sections, we estimate the MOSD duration at 0-0.99 My. This number can be further constrained by new radiometric dates from equivalent sequences worldwide, thus underpinning models on the nonsteady-state Earth system response in the immediate aftermath of the Marinoan meltdown.

  9. Sedimentary constraints on the duration of the Marinoan Oxygen-17 Depletion (MOSD) event.

    PubMed

    Killingsworth, Bryan A; Hayles, Justin A; Zhou, Chuanming; Bao, Huiming

    2013-10-29

    The ~635 Ma Marinoan glaciation is marked by dramatic Earth system perturbations. Deposition of nonmass-dependently (17)O-depleted sulfate (SO4(2-)) in worldwide postglacial sediments is, thus far, unique to this glaciation. It is proposed that an extremely high-pCO2 atmosphere can result in highly (17)O-depleted atmospheric O2, or the Marinoan Oxygen-17 Depletion (MOSD) event. This anomalous (17)O signal was imparted to sulfate of oxidative weathering origin. However, (17)O-depleted sulfate occurs in limited sedimentary intervals, suggesting that Earth surface conditions conducive to the MOSD had a finite duration. An MOSD duration can, therefore, provide much needed constraint on modeling Earth system responses at that time. Unfortunately, the sulfate (17)O record is often sparse or lacks radiometric dates. Here, we report 11 barite layers from a post-Marinoan dolostone sequence at Wushanhu in the South China Block. The (17)O depletion fluctuates in magnitude in lower layers but is persistently absent up section, providing the most confident first and last sedimentary appearance of the anomaly. δ(13)C chemostratigraphy is used to correlate the Wushanhu section to two proximal sections on the same shallow platform that lack barite layers but have published U-Pb dates that occur in dolostone and shale. Assuming a similar pattern and rate for carbonate and shale deposition among the different sections, we estimate the MOSD duration at 0-0.99 My. This number can be further constrained by new radiometric dates from equivalent sequences worldwide, thus underpinning models on the nonsteady-state Earth system response in the immediate aftermath of the Marinoan meltdown.

  10. Recirculating cooling water solute depletion models

    SciTech Connect

    Price, W.T.

    1990-03-16

    Chromates have been used for years to inhibit copper corrosion in the plant Recirculating Cooling Water (RCW) system. However, chromates have become an environmental problem in recent years both in the chromate removal plant (X-616) operation and from cooling tower drift. In response to this concern, PORTS is replacing chromates with Betz Dianodic II, a combination of phosphates, BZT, and a dispersant. This changeover started with the X-326 system in 1989. In order to control chemical concentrations in X-326 and in systems linked to it, we needed to be able to predict solute concentrations in advance of the changeover. Failure to predict and control these concentrations can result in wasted chemicals, equipment fouling, or increased corrosion. Consequently, Systems Analysis developed two solute concentration models. The first simulation represents the X-326 RCW system by itself; and models the depletion of a solute once the feed has stopped. The second simulation represents the X-326, X-330, and the X-333 systems linked together by blowdown. This second simulation represents the concentration of a solute in all three systems simultaneously. 4 figs.

  11. Thermal stress depletes energy reserves in Drosophila

    PubMed Central

    Klepsatel, Peter; Gáliková, Martina; Xu, Yanjun; Kühnlein, Ronald P.

    2016-01-01

    Understanding how environmental temperature affects metabolic and physiological functions is of crucial importance to assess the impacts of climate change on organisms. Here, we used different laboratory strains and a wild-caught population of the fruit fly Drosophila melanogaster to examine the effect of temperature on the body energy reserves of an ectothermic organism. We found that permanent ambient temperature elevation or transient thermal stress causes significant depletion of body fat stores. Surprisingly, transient thermal stress induces a lasting “memory effect” on body fat storage, which also reduces survivorship of the flies upon food deprivation later after stress exposure. Functional analyses revealed that an intact heat-shock response is essential to protect flies from temperature-dependent body fat decline. Moreover, we found that the temperature-dependent body fat reduction is caused at least in part by apoptosis of fat body cells, which might irreversibly compromise the fat storage capacity of the flies. Altogether, our results provide evidence that thermal stress has a significant negative impact on organismal energy reserves, which in turn might affect individual fitness. PMID:27641694

  12. Supercontinuum Stimulated Emission Depletion Fluorescence Lifetime Imaging

    SciTech Connect

    Lesoine, Michael; Bose, Sayantan; Petrich, Jacob; Smith, Emily

    2012-06-13

    Supercontinuum (SC) stimulated emission depletion (STED) fluorescence lifetime imaging is demonstrated by using time-correlated single-photon counting (TCSPC) detection. The spatial resolution of the developed STED instrument was measured by imaging monodispersed 40-nm fluorescent beads and then determining their fwhm, and was 36 ± 9 and 40 ± 10 nm in the X and Y coordinates, respectively. The same beads measured by confocal microscopy were 450 ± 50 and 430 ± 30 nm, which is larger than the diffraction limit of light due to underfilling the microscope objective. Underfilling the objective and time gating the signal were necessary to achieve the stated STED spatial resolution. The same fluorescence lifetime (2.0 ± 0.1 ns) was measured for the fluorescent beads by using confocal or STED lifetime imaging. The instrument has been applied to study Alexa Fluor 594-phalloidin labeled F-actin-rich projections with dimensions smaller than the diffraction limit of light in cultured cells. Fluorescence lifetimes of the actin-rich projections range from 2.2 to 2.9 ns as measured by STED lifetime imaging.

  13. Ozone depletion: 20 Years after the alarm

    SciTech Connect

    Not Available

    1994-08-15

    Scientific curiosity in 1973 led to the challenge of determining the ultimate atmospheric fate of the chlorofluoromethanes, CFC-11 (CCl[sub 3]F) and CFC-12 (CCl[sub 2]F[sub 2]), whose presence at measurable levels in surface air had been detected only two years earlier. In retrospect, the decision to pursue the chemistry of CFC molecules to their final destruction and beyond foreordained an unusual outcome because CFCs are chemically inert and easily survive under almost all natural conditions. By midsummer 1994, the world is well on its way in transition to a CFC-free economy, although not yet to a CFC-free atmosphere. The rates of increase in atmospheric concentration for the three major CFCs (CFC-11, -12, and -113) have all slowed markedly in response to the restrictions of the revised Montreal protocol. Because of their long lifetimes, however, significant but gradually diminishing quantities of CFCs will remain in the atmosphere throughout the 21st century. Atomic chlorine will continue to be released into the stratosphere as long as CFCs persist, and ozone depletion will follow. The existence of the Montreal protocol and the agreement among industrial, governmental, and university scientists on its wisdom offers considerable promise for the handling of future global environmental problems.

  14. Thermal stress depletes energy reserves in Drosophila.

    PubMed

    Klepsatel, Peter; Gáliková, Martina; Xu, Yanjun; Kühnlein, Ronald P

    2016-09-19

    Understanding how environmental temperature affects metabolic and physiological functions is of crucial importance to assess the impacts of climate change on organisms. Here, we used different laboratory strains and a wild-caught population of the fruit fly Drosophila melanogaster to examine the effect of temperature on the body energy reserves of an ectothermic organism. We found that permanent ambient temperature elevation or transient thermal stress causes significant depletion of body fat stores. Surprisingly, transient thermal stress induces a lasting "memory effect" on body fat storage, which also reduces survivorship of the flies upon food deprivation later after stress exposure. Functional analyses revealed that an intact heat-shock response is essential to protect flies from temperature-dependent body fat decline. Moreover, we found that the temperature-dependent body fat reduction is caused at least in part by apoptosis of fat body cells, which might irreversibly compromise the fat storage capacity of the flies. Altogether, our results provide evidence that thermal stress has a significant negative impact on organismal energy reserves, which in turn might affect individual fitness.

  15. Levels of depleted uranium in Kosovo soils.

    PubMed

    Sansone, U; Stellato, L; Jia, G; Rosamilia, S; Gaudino, S; Barbizzi, S; Belli, M

    2001-01-01

    The United Nations Environment Programme (UNEP) has performed a field survey at 11 sites located in Kosovo, where depleted uranium (DU) ammunitions were used by the North Atlantic Treaty Organization (NATO) during the last Balkans conflict (1999). Soil sampling was performed to assess the spread of DU ground contamination around and within the NATO target sites and the migration of DU along the soil profile. The 234U/238U and 235U/238U activity concentration ratios have been used as an indicator of natural against anthropogenic sources of uranium. The results show that levels of 238U activity concentrations in soils above 100 Bq x kg(-1) can be considered a 'tracer' of the presence of DU in soils. The results also indicate that detectable ground surface contamination by DU is limited to areas within a few metres from localised points of concentrated contamination caused by penetrator impacts. Vertical distribution of DU along the soil profile is measurable up to a depth of 10-20 cm. This latter aspect is of particular relevance for the potential risk of future contamination of groundwater.

  16. Residue depletion of tilmicosin in chicken tissues.

    PubMed

    Zhang, Yue; Jiang, Haiyang; Jin, Xingjun; Shen, Zhangqi; Shen, Jianzhong; Fu, Caixia; Guo, Junlin

    2004-05-01

    A high-performance liquid chromatography (HPLC) method with detection at 290 nm was modified and validated for the determination of tilmicosin residues in broiler chicken tissues. The limits of detection (LOD) of the method were 0.01 microg/g for muscle and 0.025 microg/g for liver and kidney. Average recoveries ranged from 80.4 to 88.3%. Relative standard deviation values ranged from 5.2 to 12.1%. Residue depletion of tilmicosin in broiler chickens was examined after dosing over a 5-day period by incorporation of the drug into drinking water at 37.5 and 75.0 mg/L. Tilmicosin concentrations in liver and kidney were highest on day 3 of medication and on day 5 in muscle, in both low- and high-dose groups. The residue levels in both groups were significantly higher in liver than in kidney or muscle. A minimum withdrawal time of 9 days was indicated for residue levels in muscle, liver, and kidney tissues below the maximum residue level (MRL).

  17. Thermal stress depletes energy reserves in Drosophila.

    PubMed

    Klepsatel, Peter; Gáliková, Martina; Xu, Yanjun; Kühnlein, Ronald P

    2016-01-01

    Understanding how environmental temperature affects metabolic and physiological functions is of crucial importance to assess the impacts of climate change on organisms. Here, we used different laboratory strains and a wild-caught population of the fruit fly Drosophila melanogaster to examine the effect of temperature on the body energy reserves of an ectothermic organism. We found that permanent ambient temperature elevation or transient thermal stress causes significant depletion of body fat stores. Surprisingly, transient thermal stress induces a lasting "memory effect" on body fat storage, which also reduces survivorship of the flies upon food deprivation later after stress exposure. Functional analyses revealed that an intact heat-shock response is essential to protect flies from temperature-dependent body fat decline. Moreover, we found that the temperature-dependent body fat reduction is caused at least in part by apoptosis of fat body cells, which might irreversibly compromise the fat storage capacity of the flies. Altogether, our results provide evidence that thermal stress has a significant negative impact on organismal energy reserves, which in turn might affect individual fitness. PMID:27641694

  18. Impact of subjacent rocks at the water and air regime of the depleted peat deposits

    NASA Astrophysics Data System (ADS)

    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

  19. Influence of Roller Burnishing Parameters on Depletion of Plasticity Reserve

    NASA Astrophysics Data System (ADS)

    Blumenstein, V. Yu; Petrenko, K. P.

    2016-04-01

    Roller burnishing process considerably increases surface quality and service life of machine parts. Efficiency of roller burnishing rises greatly when technological inheritance (TI) is taken into account. Research results of degree of plasticity reserve depletion (DPRD) while roller burnishing are presented. Results obtained made it possible to establish mechanisms of strain accumulation and plasticity reserve depletion according to roller burnishing parameters.

  20. Analysis of Hydrogen Depletion Using a Scaled Passive Autocatalytic Recombiner

    SciTech Connect

    Blanchat, T.K.; Malliakos, A.

    1998-10-28

    Hydrogen depletion tests of a scaled passive autocatalytic recombine (pAR) were performed in the Surtsey test vessel at Sandia National Laboratories (SNL). The experiments were used to determine the hydrogen depletion rate of a PAR in the presence of steam and also to evaluate the effect of scale (number of cartridges) on the PAR performance at both low and high hydrogen concentrations.

  1. Optimal Allocation of Sampling Effort in Depletion Surveys

    EPA Science Inventory

    We consider the problem of designing a depletion or removal survey as part of estimating animal abundance for populations with imperfect capture or detection rates. In a depletion survey, animals are captured from a given area, counted, and withheld from the population. This proc...

  2. 26 CFR 1.613-1 - Percentage depletion; general rule.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Percentage depletion; general rule. 1.613-1 Section 1.613-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Natural Resources § 1.613-1 Percentage depletion;...

  3. 26 CFR 1.613-1 - Percentage depletion; general rule.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 7 2011-04-01 2009-04-01 true Percentage depletion; general rule. 1.613-1 Section 1.613-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Natural Resources § 1.613-1 Percentage depletion; general rule. (a) In general. In the case of a...

  4. Glutathione depletion and acute exercise increase O-GlcNAc protein modification in rat skeletal muscle.

    PubMed

    Peternelj, Tina Tinkara; Marsh, Susan A; Strobel, Natalie A; Matsumoto, Aya; Briskey, David; Dalbo, Vincent J; Tucker, Patrick S; Coombes, Jeff S

    2015-02-01

    Post-translational modification of intracellular proteins with O-linked β-N-acetylglucosamine (O-GlcNAc) profoundly affects protein structure, function, and metabolism. Although many skeletal muscle proteins are O-GlcNAcylated, the modification has not been extensively studied in this tissue, especially in the context of exercise. This study investigated the effects of glutathione depletion and acute exercise on O-GlcNAc protein modification in rat skeletal muscle. Diethyl maleate (DEM) was used to deplete intracellular glutathione and rats were subjected to a treadmill run. White gastrocnemius and soleus muscles were analyzed for glutathione status, O-GlcNAc and O-GlcNAc transferase (OGT) protein levels, and mRNA expression of OGT, O-GlcNAcase and glutamine:fructose-6-phosphate amidotransferase. DEM and exercise both reduced intracellular glutathione and increased O-GlcNAc. DEM upregulated OGT protein expression. The effects of the interventions were significant 4 h after exercise (P < 0.05). The changes in the mRNA levels of O-GlcNAc enzymes were different in the two muscles, potentially resulting from different rates of oxidative stress and metabolic demands between the muscle types. These findings indicate that oxidative environment promotes O-GlcNAcylation in skeletal muscle and suggest an interrelationship between cellular redox state and O-GlcNAc protein modification. This could represent one mechanism underlying cellular adaptation to oxidative stress and health benefits of exercise. PMID:25416863

  5. Depletion of Appalachian coal reserves - how soon?

    USGS Publications Warehouse

    Milici, R.C.

    2000-01-01

    Much of the coal consumed in the US since the end of the last century has been produced from the Pennsylvanian strata of the Appalachian basin. Even though quantities mined in the past are less than they are today, this basin yielded from 70% to 80% of the nation's annual coal production from the end of the last century until the early 1970s. During the last 25 years, the proportion of the nation's coal that was produced annually from the Appalachian basin has declined markedly, and today it is only about 40% of the total. The amount of coal produced annually in the Appalachian basin, however, has been rising slowly over the last several decades, and has ranged generally from 400 to 500 million tons (Mt) per year. A large proportion of Appalachian historical production has come from relatively few counties in southwestern Pennsylvania, northern and southern West Virginia, eastern Kentucky, Virginia and Alabama. Many of these counties are decades past their years of peak production and several are almost depleted of economic deposits of coal. Because the current major consumer of Appalachian coal is the electric power industry, coal quality, especially sulfur content, has a great impact on its marketability. High-sulfur coal deposits in western Pennsylvania and Ohio are in low demand when compared with the lower sulfur coals of Virginia and southern West Virginia. Only five counties in the basin that have produced 500 Mt or more exhibit increasing rates of production at relatively high levels. Of these, six are in the central part of the basin and only one, Greene County, Pennsylvania, is in the northern part of the basin. Decline rate models, based on production decline rates and the decline rate of the estimated, 'potential' reserve, indicate that Appalachian basin annual coal production will be 200 Mt or less by the middle of the next century. Published by Elsevier Science B.V.Much of the coal consumed in the US since the end of the last century has been produced

  6. Charged micelle depletion attraction and interfacial colloidal phase behavior.

    PubMed

    Iracki, Tara D; Beltran-Villegas, Daniel J; Eichmann, Shannon L; Bevan, Michael A

    2010-12-21

    Ensemble total internal reflection microscopy (TIRM) is used to directly measure the evolution of colloid-surface depletion attraction with increasing sodium dodecyl sulfate (SDS) concentration near the critical micelle concentration (CMC). Measured potentials are well described by a modified Asakura-Oosawa (AO) depletion potential in addition to electrostatic and van der Waals contributions. The modified AO potential includes effects of electrostatic interactions between micelles and surfaces via effective depletant dimensions in an excluded volume term and partitioning in an osmotic pressure term. Directly measured colloid-surface depletion potentials are used in Monte Carlo (MC) simulations to capture video microscopy (VM) measurements of micelle-mediated quasi-two-dimensional phase behavior including fluid, crystal, and gel microstructures. Our findings provide information to develop more rigorous and analytically simple models of depletion attraction in charged micellar systems. PMID:21077612

  7. Ozone depletion during solar proton events in solar cycle 21

    NASA Technical Reports Server (NTRS)

    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.

  8. The timing and mechanism of depletion in Lewisian granulites

    NASA Technical Reports Server (NTRS)

    Cohen, A. S.; Onions, R. K.; Ohara, M. J.

    1988-01-01

    Large Ion Lithophile (LIL) depletion in Lewisian granulites is discussed. Severe depletions in U, Th, and other LIL have been well documented in Lewisan mafic and felsic gneisses, but new Pb isotopic analyses show little or no depletion in lithologies with high solidus temperatures, such as peridotite. This suggests that LIL transport in this terrane took place by removal of partial melts rather than by pervasive flooding with externally derived CO2. The Pb and Nd isotopic data gathered on these rocks show that the depletion and granulite metamorphism are distinct events about 250 Ma apart. Both fluid inclusions and cation exchange geothermometers date from the later metamorphic event and therefore have little bearing on the depletion event, suggesting a note of caution for interpretations of other granulite terranes.

  9. Ionogram range/time plots, satellite traces and optical depletions

    NASA Astrophysics Data System (ADS)

    Lynn, Kenneth; Shiokawa, Kazuo; Otsuka, Yuichi; Wilkinson, Phil

    2012-07-01

    Range/time plots derived from 5 minute ionograms have a variety of uses including finding TIDs, following major height variations in the F2 ionosphere and tracking the movement of low latitude electron depletions as verified by co-incident observations by optical methods. This paper investigates these applications with particular emphasis on following optical depletions via ionosonde as observed at Darwin, Australia. Similar additional range/time plots are also discussed from Vanimo and Port Moresby in New Guinea and Tennant Creek and Townsville in Australia. While much theoretical work has been expended on explaining the development of equatorial bubble/depletions, current work highlights the apparently strong development of depletions at times of year when the pre-sunset height rise and following fall is minimal in contrast to current conventional thinking. In contrast, depletions are not observed at Australian equatorial longitudes when the pre- and post- sunset height variations are greatest in magnitude and consistency.

  10. Barium Depletion in Hollow Cathode Emitters

    NASA Technical Reports Server (NTRS)

    Polk, James E.; Capece, Angela M.; Mikellides, Ioannis G.; Katz, Ira

    2009-01-01

    The effect of tungsten erosion, transport and redeposition on the operation of dispenser hollow cathodes was investigated in detailed examinations of the discharge cathode inserts from an 8200 hour and a 30,352 hour ion engine wear test. Erosion and subsequent re-deposition of tungsten in the electron emission zone at the downstream end of the insert reduces the porosity of the tungsten matrix, preventing the ow of barium from the interior. This inhibits the interfacial reactions of the barium-calcium-aluminate impregnant with the tungsten in the pores. A numerical model of barium transport in the internal xenon discharge plasma shows that the barium required to reduce the work function in the emission zone can be supplied from upstream through the gas phase. Barium that flows out of the pores of the tungsten insert is rapidly ionized in the xenon discharge and pushed back to the emitter surface by the electric field and drag from the xenon ion flow. This barium ion flux is sufficient to maintain a barium surface coverage at the downstream end greater than 0.6, even if local barium production at that point is inhibited by tungsten deposits. The model also shows that the neutral barium pressure exceeds the equilibrium vapor pressure of the impregnant decomposition reaction over much of the insert length, so the reactions are suppressed. Only a small region upstream of the zone blocked by tungsten deposits is active and supplies the required barium. These results indicate that hollow cathode failure models based on barium depletion rates in vacuum dispenser cathodes are very conservative.

  11. Ozone Depletion Potential of CH3Br

    NASA Technical Reports Server (NTRS)

    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.

  12. Ozone-exposure depletes vitamin E and induces lipid peroxidation in murine stratum corneum.

    PubMed

    Thiele, J J; Traber, M G; Polefka, T G; Cross, C E; Packer, L

    1997-05-01

    The presence of ozone (O(3)) in photochemical smog is an important health concern. We hypothesized that the stratum corneum (SC), as the outermost skin layer and the permeability barrier of the skin, represents a sensitive target for O(3)-induced oxidative stress. To test this hypothesis, SKH-1 hairless mice were anesthetized and exposed for 2 h to O(3) by using two strategies: (i) single exposures to 0 (n = 12), 1 (n = 4), 5 (n = 4), and 10 (n = 4) ppm; and (ii) repeated daily exposures to 0 ppm (controls; n = 4) and 1 ppm (n = 4) for six consecutive days. New techniques based on the removal of SC by tape stripping were used to analyze the biologic effects of O(3) with respect to vitamin E depletion and lipid peroxidation. SC tissue was extracted from the tape and immediately analyzed by HPLC for vitamin E and malondialdehyde (MDA) concentrations. After in vivo exposure to increasing O(3) doses, vitamin E was depleted and MDA formation was increased, both in a dose-dependent manner. Remarkably, repeated low-level O(3) exposures resulted in cumulative oxidative effects in the SC: As compared with O(3) exposures of 0 ppm (alpha-tocopherol, 8.95 +/- 1.3 pmol per mg; gamma-tocopherol, 3.00 +/- 0.3 pmol per mg; MDA, 3.69 +/- 0.3 pmol per mg), vitamin E was depleted (alpha-tocopherol, 2.90 +/- 0.6 pmol per mg, p < 0.001; gamma-tocopherol, 0.5 +/- 0.1 pmol per mg, p < 0.001) and MDA levels were increased (4.5 +/- 0.2; p < 0.01). This report demonstrates the unique susceptibility of the SC to oxidative damage upon exposure to O(3).

  13. Accumulation of manganese superoxide dismutase under metal-depleted conditions: proposed role for zinc ions in cellular redox balance.

    PubMed Central

    Otsu, Kaoru; Ikeda, Yoshitaka; Fujii, Junichi

    2004-01-01

    A diet low in copper results in increased levels of MnSOD (manganese superoxide dismutase), a critical antioxidative enzyme conferring protection against oxidative stress, in rat liver mitochondria. The mechanism for this was investigated using cultured HepG2 cells, a human hepatocellular carcinoma-derived line. MnSOD activity increased 5-7-fold during incubation in a medium supplemented with metal-depleted fetal bovine serum, with a corresponding elevation of its mRNA levels. Metal depletion also decreased CuZnSOD and glutathione peroxidase levels to approx. 70-80% of baseline. When zinc ions were added to the medium at micromolar levels, MnSOD accumulation was suppressed; however, copper ions had essentially no effect on MnSOD expression. Since the intracellular redox status was shifted to a more oxidized state by metal depletion, we examined the DNA-binding activity of NF-kappaB (nuclear factor-kappaB), an oxidative stress-sensitive transactivating factor that plays a primary role in MnSOD induction. A gel shift assay indicated that the DNA-binding activity of NF-kappaB was increased in cells maintained in metal-depleted culture, suggesting the involvement of the transactivating function of NF-kappaB in this induction. This was further supported by the observation that curcumin suppressed both the DNA-binding activity of NF-kappaB and the induction of MnSOD mRNA in cells cultivated under metal-depleted conditions. These results suggest that the level of zinc, rather than copper, is a critical regulatory factor in MnSOD expression. It is possible that a deficiency of zinc in the low-copper diet may be primarily involved in MnSOD induction. PMID:14531733

  14. Serotonin and social norms: tryptophan depletion impairs social comparison and leads to resource depletion in a multiplayer harvesting game.

    PubMed

    Bilderbeck, Amy C; Brown, Gordon D A; Read, Judi; Woolrich, Mark; Cowen, Phillip J; Behrens, Tim E J; Rogers, Robert D

    2014-07-01

    How do people sustain resources for the benefit of individuals and communities and avoid the tragedy of the commons, in which shared resources become exhausted? In the present study, we examined the role of serotonin activity and social norms in the management of depletable resources. Healthy adults, alongside social partners, completed a multiplayer resource-dilemma game in which they repeatedly harvested from a partially replenishable monetary resource. Dietary tryptophan depletion, leading to reduced serotonin activity, was associated with aggressive harvesting strategies and disrupted use of the social norms given by distributions of other players' harvests. Tryptophan-depleted participants more frequently exhausted the resource completely and also accumulated fewer rewards than participants who were not tryptophan depleted. Our findings show that rank-based social comparisons are crucial to the management of depletable resources, and that serotonin mediates responses to social norms. PMID:24815611

  15. Phytomediated Biostimulation of the Autochthonous Bacterial Community for the Acceleration of the Depletion of Polycyclic Aromatic Hydrocarbons in Contaminated Sediments

    PubMed Central

    Gentini, Alessandro; Becarelli, Simone; Azaizeh, Hassan

    2014-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic contaminants causing hazards to organisms including humans. The objective of the study was to validate the vegetation of dredged sediments with Phragmites australis as an exploitable biostimulation approach to accelerate the depletion of PAHs in nitrogen spiked sediments. Vegetation with Phragmites australis resulted in being an efficient biostimulation approach for the depletion of an aged PAHs contamination (229.67 ± 15.56 μg PAHs/g dry weight of sediment) in dredged sediments. Phragmites australis accelerated the oxidation of the PAHs by rhizodegradation. The phytobased approach resulted in 58.47% of PAHs depletion. The effects of the treatment have been analyzed in terms of both contaminant depletion and changes in relative abundance of the metabolically active Gram positive and Gram negative PAHs degraders. The metabolically active degraders were quantified both in the sediments and in the root endospheric microbial community. Quantitative real-time PCR reactions have been performed on the retrotranscribed transcripts encoding the Gram positive and Gram negative large α subunit (RHDα) of the aromatic ring hydroxylating dioxygenases. The Gram positive degraders resulted in being selectively favored by vegetation with Phragmites australis and mandatory for the depletion of the six ring condensed indeno[1,2,3-cd]pyrene and benzo[g,h,i]perylene. PMID:25170516

  16. Renal depletion of myo-inositol is associated with its increased degradation in animal models of metabolic disease.

    PubMed

    Chang, H-H; Chao, H-N; Walker, C S; Choong, S-Y; Phillips, A; Loomes, K M

    2015-11-01

    Renal depletion of myo-inositol (MI) is associated with the pathogenesis of diabetic nephropathy in animal models, but the underlying mechanisms involved are unclear. We hypothesized that MI depletion was due to changes in inositol metabolism and therefore examined the expression of genes regulating de novo biosynthesis, reabsorption, and catabolism of MI. We also extended the analyses from diabetes mellitus to animal models of dietary-induced obesity and hypertension. We found that renal MI depletion was pervasive across these three distinct disease states in the relative order: hypertension (-51%)>diabetes mellitus (-35%)>dietary-induced obesity (-19%). In 4-wk diabetic kidneys and in kidneys derived from insulin-resistant and hypertensive rats, MI depletion was correlated with activity of the MI-degrading enzyme myo-inositol oxygenase (MIOX). By contrast, there was decreased MIOX expression in 8-wk diabetic kidneys. Immunohistochemistry localized the MI-degrading pathway comprising MIOX and the glucuronate-xylulose (GX) pathway to the proximal tubules within the renal cortex. These findings indicate that MI depletion could reflect increased catabolism through MIOX and the GX pathway and implicate a common pathological mechanism contributing to renal oxidative stress in metabolic disease.

  17. Depletion of B cells in murine lupus: efficacy and resistance.

    PubMed

    Ahuja, Anupama; Shupe, Jonathan; Dunn, Robert; Kashgarian, Michael; Kehry, Marilyn R; Shlomchik, Mark J

    2007-09-01

    In mice, genetic deletion of B cells strongly suppresses systemic autoimmunity, providing a rationale for depleting B cells to treat autoimmunity. In fact, B cell depletion with rituximab is approved for rheumatoid arthritis patients, and clinical trials are underway for systemic lupus erythematosus. Yet, basic questions concerning mechanism, pathologic effect, and extent of B cell depletion cannot be easily studied in humans. To better understand how B cell depletion affects autoimmunity, we have generated a transgenic mouse expressing human CD20 on B cells in an autoimmune-prone MRL/MpJ-Fas(lpr) (MRL/lpr) background. Using high doses of a murine anti-human CD20 mAb, we were able to achieve significant depletion of B cells, which in turn markedly ameliorated clinical and histologic disease as well as antinuclear Ab and serum autoantibody levels. However, we also found that B cells were quite refractory to depletion in autoimmune-prone strains compared with non-autoimmune-prone strains. This was true with multiple anti-CD20 Abs, including a new anti-mouse CD20 Ab, and in several different autoimmune-prone strains. Thus, whereas successful B cell depletion is a promising therapy for lupus, at least some patients might be resistant to the therapy as a byproduct of the autoimmune condition itself.

  18. CO depletion in ATLASGAL-selected high-mass clumps

    NASA Astrophysics Data System (ADS)

    Giannetti, A.; Wyrowski, F.; Brand, J.; Csengeri, T.; Fontani, F.; Walmsley, C. M.; Nguyen Luong, Q.; Beuther, H.; Schuller, F.; Güsten, R.; Menten, K. M.

    2016-05-01

    In the low-mass regime, it is found that the gas-phase abundances of C-bearing molecules in cold starless cores rapidly decrease with increasing density. Here the molecules tend to stick to the grains, forming ice mantles. We study CO depletion in the TOP100 sample of the ATLASGAL survey, and investigate its correlation with evolutionary stage and with the physical parameters of the sources. We use low-J emission lines of CO isotopologues and the dust continuum emission to infer the depletion factor fD. RATRAN one-dimensional models were also used to determine fD and to investigate the presence of depletion above a density threshold. The isotopic ratios and optical depth were derived with a Bayesian approach. We find a significant number of clumps with a large CO depletion, up to ˜20. Larger values are found for colder clumps, thus for earlier evolutionary phases. For massive clumps in the earliest stages of evolution we estimate the radius of the region where CO depletion is important to be a few tenths of a pc. CO depletion in high-mass clumps seems to behave as in the low-mass regime, with less evolved clumps showing larger values for the depletion than their more evolved counterparts, and increasing for denser sources.

  19. Long-term groundwater depletion in the United States.

    PubMed

    Konikow, Leonard F

    2015-01-01

    The volume of groundwater stored in the subsurface in the United States decreased by almost 1000 km3 during 1900-2008. The aquifer systems with the three largest volumes of storage depletion include the High Plains aquifer, the Mississippi Embayment section of the Gulf Coastal Plain aquifer system, and the Central Valley of California. Depletion rates accelerated during 1945-1960, averaging 13.6 km3/year during the last half of the century, and after 2000 increased again to about 24 km3/year. Depletion intensity is a new parameter, introduced here, to provide a more consistent basis for comparing storage depletion problems among various aquifers by factoring in time and areal extent of the aquifer. During 2001-2008, the Central Valley of California had the largest depletion intensity. Groundwater depletion in the United States can explain 1.4% of observed sea-level rise during the 108-year study period and 2.1% during 2001-2008. Groundwater depletion must be confronted on local and regional scales to help reduce demand (primarily in irrigated agriculture) and/or increase supply.

  20. Adjoint simulation of stream depletion due to aquifer pumping.

    PubMed

    Neupauer, Roseanna M; Griebling, Scott A

    2012-01-01

    If an aquifer is hydraulically connected to an adjacent stream, a pumping well operating in the aquifer will draw some water from aquifer storage and some water from the stream, causing stream depletion. Several analytical, semi-analytical, and numerical approaches have been developed to estimate stream depletion due to pumping. These approaches are effective if the well location is known. If a new well is to be installed, it may be desirable to install the well at a location where stream depletion is minimal. If several possible locations are considered for the location of a new well, stream depletion would have to be estimated for all possible well locations, which can be computationally inefficient. The adjoint approach for estimating stream depletion is a more efficient alternative because with one simulation of the adjoint model, stream depletion can be estimated for pumping at a well at any location. We derive the adjoint equations for a coupled system with a confined aquifer, an overlying unconfined aquifer, and a river that is hydraulically connected to the unconfined aquifer. We assume that the stage in the river is known, and is independent of the stream depletion, consistent with the assumptions of the MODFLOW river package. We describe how the adjoint equations can be solved using MODFLOW. In an illustrative example, we show that for this scenario, the adjoint approach is as accurate as standard forward numerical simulation methods, and requires substantially less computational effort.

  1. Long-term groundwater depletion in the United States

    USGS Publications Warehouse

    Konikow, Leonard F.

    2015-01-01

    The volume of groundwater stored in the subsurface in the United States decreased by almost 1000 km3 during 1900–2008. The aquifer systems with the three largest volumes of storage depletion include the High Plains aquifer, the Mississippi Embayment section of the Gulf Coastal Plain aquifer system, and the Central Valley of California. Depletion rates accelerated during 1945–1960, averaging 13.6 km3/year during the last half of the century, and after 2000 increased again to about 24 km3/year. Depletion intensity is a new parameter, introduced here, to provide a more consistent basis for comparing storage depletion problems among various aquifers by factoring in time and areal extent of the aquifer. During 2001–2008, the Central Valley of California had the largest depletion intensity. Groundwater depletion in the United States can explain 1.4% of observed sea-level rise during the 108-year study period and 2.1% during 2001–2008. Groundwater depletion must be confronted on local and regional scales to help reduce demand (primarily in irrigated agriculture) and/or increase supply.

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

    PubMed

    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.

  3. Semiconductor-based photoelectrochemical water splitting at the limit of very wide depletion region

    DOE PAGESBeta

    Liu, Mingzhao; Lyons, John L.; Yan, Danhua H.; Hybertsen, Mark S.

    2015-11-23

    In semiconductor-based photoelectrochemical (PEC) water splitting, carrier separation and delivery largely relies on the depletion region formed at the semiconductor/water interface. As a Schottky junction device, the trade-off between photon collection and minority carrier delivery remains a persistent obstacle for maximizing the performance of a water splitting photoelectrode. Here, it is demonstrated that the PEC water splitting efficiency for an n-SrTiO3 (n-STO) photoanode is improved very significantly despite its weak indirect band gap optical absorption (α < 10⁴ cm⁻¹), by widening the depletion region through engineering its doping density and profile. Graded doped n-SrTiO3 photoanodes are fabricated with their bulkmore » heavily doped with oxygen vacancies but their surface lightly doped over a tunable depth of a few hundred nanometers, through a simple low temperature re-oxidation technique. The graded doping profile widens the depletion region to over 500 nm, thus leading to very efficient charge carrier separation and high quantum efficiency (>70%) for the weak indirect transition. As a result, this simultaneous optimization of the light absorption, minority carrier (hole) delivery, and majority carrier (electron) transport by means of a graded doping architecture may be useful for other indirect band gap photocatalysts that suffer from a similar problem of weak optical absorption.« less

  4. Semiconductor-based photoelectrochemical water splitting at the limit of very wide depletion region

    SciTech Connect

    Liu, Mingzhao; Lyons, John L.; Yan, Danhua H.; Hybertsen, Mark S.

    2015-11-23

    In semiconductor-based photoelectrochemical (PEC) water splitting, carrier separation and delivery largely relies on the depletion region formed at the semiconductor/water interface. As a Schottky junction device, the trade-off between photon collection and minority carrier delivery remains a persistent obstacle for maximizing the performance of a water splitting photoelectrode. Here, it is demonstrated that the PEC water splitting efficiency for an n-SrTiO3 (n-STO) photoanode is improved very significantly despite its weak indirect band gap optical absorption (α < 10⁴ cm⁻¹), by widening the depletion region through engineering its doping density and profile. Graded doped n-SrTiO3 photoanodes are fabricated with their bulk heavily doped with oxygen vacancies but their surface lightly doped over a tunable depth of a few hundred nanometers, through a simple low temperature re-oxidation technique. The graded doping profile widens the depletion region to over 500 nm, thus leading to very efficient charge carrier separation and high quantum efficiency (>70%) for the weak indirect transition. As a result, this simultaneous optimization of the light absorption, minority carrier (hole) delivery, and majority carrier (electron) transport by means of a graded doping architecture may be useful for other indirect band gap photocatalysts that suffer from a similar problem of weak optical absorption.

  5. A Multilab Preregistered Replication of the Ego-Depletion Effect.

    PubMed

    Hagger, Martin S; Chatzisarantis, Nikos L D

    2016-07-01

    Good self-control has been linked to adaptive outcomes such as better health, cohesive personal relationships, success in the workplace and at school, and less susceptibility to crime and addictions. In contrast, self-control failure is linked to maladaptive outcomes. Understanding the mechanisms by which self-control predicts behavior may assist in promoting better regulation and outcomes. A popular approach to understanding self-control is the strength or resource depletion model. Self-control is conceptualized as a limited resource that becomes depleted after a period of exertion resulting in self-control failure. The model has typically been tested using a sequential-task experimental paradigm, in which people completing an initial self-control task have reduced self-control capacity and poorer performance on a subsequent task, a state known as ego depletion Although a meta-analysis of ego-depletion experiments found a medium-sized effect, subsequent meta-analyses have questioned the size and existence of the effect and identified instances of possible bias. The analyses served as a catalyst for the current Registered Replication Report of the ego-depletion effect. Multiple laboratories (k = 23, total N = 2,141) conducted replications of a standardized ego-depletion protocol based on a sequential-task paradigm by Sripada et al. Meta-analysis of the studies revealed that the size of the ego-depletion effect was small with 95% confidence intervals (CIs) that encompassed zero (d = 0.04, 95% CI [-0.07, 0.15]. We discuss implications of the findings for the ego-depletion effect and the resource depletion model of self-control. PMID:27474142

  6. Electron depletion and accumulation regions in n-type copper-hexadecafluoro-phthalocyanine and their effects on electronic properties

    NASA Astrophysics Data System (ADS)

    Wang, Haibo; Liu, Zengtao; Fai Lo, Ming; Wai Ng, Tsz; Yan, Donghang; Lee, Chun-Sing

    2012-03-01

    We investigated interfacial electronic structures of organic/inorganic heterojunctions formed between copper-hexadecafluoro-phthalocyanine (F16CuPc) and molybdenum trioxide or lead monoxide by ultraviolet and x-ray photoemission spectroscopies. Obvious energy level bending in F16CuPc shows the formation of electron depletion and accumulation regions in its contact with molybdenum and lead oxides, respectively. Effects of these depletion/accumulation zones were studied via electronic characteristics of field-effect transistors constructed with these heterojunctions as active layers. Finally, a summary about the heterojunction including organic semiconductor (n-type and p-type) and metal oxide was given, which demonstrated that organic semiconductors can form various space charge regions like conventional inorganic semiconductors.

  7. The 'depletion layer' of amorphous p-n junctions

    NASA Technical Reports Server (NTRS)

    Von Roos, O.

    1981-01-01

    It is shown that within reasonable approximations for the density of state distribution within the mobility gap of a:Si, a one-to-one correspondence exists between the electric field distribution in the transition region of an amorphous p-n junction and that in the depletion layer of a crystalline p-n junction. Thus it is inferred that the depletion layer approximation which leads to a parabolic potential distribution within the depletion layer of crystalline junctions also constitutes a fair approximation in the case of amorphous junctions. This fact greatly simplifies an analysis of solid-state electronic devices based on amorphous material (i.e., solar cells).

  8. 3-D stimulated emission depletion microscopy with programmable aberration correction.

    PubMed

    Lenz, Martin O; Sinclair, Hugo G; Savell, Alexander; Clegg, James H; Brown, Alice C N; Davis, Daniel M; Dunsby, Chris; Neil, Mark A A; French, Paul M W

    2014-01-01

    We present a stimulated emission depletion (STED) microscope that provides 3-D super resolution by simultaneous depletion using beams with both a helical phase profile for enhanced lateral resolution and an annular phase profile to enhance axial resolution. The 3-D depletion point spread function is realised using a single spatial light modulator that can also be programmed to compensate for aberrations in the microscope and the sample. We apply it to demonstrate the first 3-D super-resolved imaging of an immunological synapse between a Natural Killer cell and its target cell.

  9. Astrocytes Prevent Ethanol Induced Apoptosis of Nrf2 Depleted Neurons by Maintaining GSH Homeostasis.

    PubMed

    Narasimhan, Madhusudhanan; Rathinam, Marylatha; Patel, Dhyanesh; Henderson, George; Mahimainathan, Lenin

    2012-07-01

    Glutathione (GSH), a major cellular antioxidant protects cells against oxidative stress injury. Nuclear factor erythroid 2-related factor 2 (NFE2L2/Nrf2) is a redox sensitive master regulator of battery of antioxidant enzymes including those involved in GSH antioxidant machinery. Earlier we reported that ethanol (ETOH) elicits apoptotic death of primary cortical neurons (PCNs) which in partly due to depletion of intracellular GSH levels. Further a recent report from our laboratory illustrated that ETOH exacerbated the dysregulation of GSH and caspase mediated cell death of cortical neurons that are compromised in Nrf2 machinery (Narasimhan et al., 2011). In various experimental models of neurodegeneration, neuronal antioxidant defenses mainly GSH has been shown to be supported by astrocytes. We therefore sought to determine whether astrocytes can render protection to neurons against ETOH toxicity, particularly when the function of Nrf2 is compromised in neurons. The experimental model consisted of co-culturing primary cortical astrocytes (PCA) with Nrf2 downregulated PCNs that were exposed with 4 mg/mL ETOH for 24 h. Monochlorobimane (MCB) staining followed by FACS analysis showed that astrocytes blocked ETOH induced GSH decrement in Nrf2-silenced neurons as opposed to exaggerated GSH depletion in Nrf2 downregulated PCNs alone. Similarly, the heightened activation of caspase 3/7 observed in Nrf2-compromised neurons was attenuated when co-cultured with astrocytes as measured by luminescence based caspase Glo assay. Furthermore, annexin-V-FITC staining followed by FACS analysis revealed that Nrf2 depleted neurons showed resistance to ETOH induced neuronal apoptosis when co-cultured with astrocytes. Thus, the current study identifies ETOH induced dysregulation of GSH and associated apoptotic events observed in Nrf2-depleted neurons can be blocked by astrocytes. Further our results suggest that this neuroprotective effect of astrocyte despite dysfunctional Nrf2 system

  10. Theophylline prevents NAD{sup +} depletion via PARP-1 inhibition in human pulmonary epithelial cells

    SciTech Connect

    Moonen, Harald J.J. . E-mail: h.moonen@grat.unimaas.nl; Geraets, Liesbeth; Vaarhorst, Anika; Bast, Aalt; Wouters, Emiel F.M.; Hageman, Geja J.

    2005-12-30

    Oxidative DNA damage, as occurs during exacerbations in chronic obstructive pulmonary disease (COPD), highly activates the nuclear enzyme poly(ADP-ribose)polymerase-1 (PARP-1). This can lead to cellular depletion of its substrate NAD{sup +}, resulting in an energy crisis and ultimately in cell death. Inhibition of PARP-1 results in preservation of the intracellular NAD{sup +} pool, and of NAD{sup +}-dependent cellular processes. In this study, PARP-1 activation by hydrogen peroxide decreased intracellular NAD{sup +} levels in human pulmonary epithelial cells, which was found to be prevented in a dose-dependent manner by theophylline, a widely used compound in the treatment of COPD. This enzyme inhibition by theophylline was confirmed in an ELISA using purified human PARP-1 and was found to be competitive by nature. These findings provide new mechanistic insights into the therapeutic effect of theophylline in oxidative stress-induced lung pathologies.

  11. A review of the environmental behavior of uranium derived from depleted uranium alloy penetrators

    SciTech Connect

    Erikson, R.L.; Hostetler, C.J.; Divine, J.R.; Price, K.R.

    1990-01-01

    The use of depleted uranium (DU) penetrators as armor-piercing projectiles in the field results in the release of uranium into the environment. Elevated levels of uranium in the environment are of concern because of radioactivity and chemical toxicity. In addition to the direct contamination of the soil with uranium, the penetrators will also chemically react with rainwater and surface water. Uranium may be oxidized and leached into surface water or groundwater and may subsequently be transported. In this report, we review some of the factors affecting the oxidation of the DU metal and the factors influencing the leaching and mobility of uranium through surface water and groundwater pathways, and the uptake of uranium by plants growing in contaminated soils. 29 refs., 10 figs., 3 tabs.

  12. A depleted, not ideally chondritic bulk Earth: The explosive-volcanic basalt loss hypothesis

    NASA Astrophysics Data System (ADS)

    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

  13. Asymmetric spindle pole formation in CPAP-depleted mitotic cells.

    PubMed

    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.

  14. Hyperspectral stimulated emission depletion microscopy and methods of use thereof

    DOEpatents

    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").

  15. Fluorescence depletion properties of insulin–gold nanoclusters

    PubMed Central

    Chen, Po-Fu; Liu, Chien-Liang; Lin, Wei-Kuan; Chen, Kuan-Chieh; Chou, Pi-Tai; Chu, Shi-Wei

    2015-01-01

    Insulin–gold nanoclusters exhibit outstanding biocompatibility, photostability, and fluorescence quantum efficiency. However, they have never been used in superresolution microscopy, which requires nonlinear switching or saturation of fluorescence. Here we examine the fluorescence and stimulated emission depletion properties of gold nanoclusters. Their bleaching rate is very slow, demonstrating superior photostability. Surprisingly, however, the best depletion efficiency is less than 70%, whereas the depletion intensity requirement is much higher than the expectation from a simple two-level model. Fluorescence lifetime measurement revealed two distinct lifetime components, which indicate intersystem and reverse intersystem crossing during excitation. Based on population dynamic calculation, excellent agreement of the maximal depletion efficiency is found. Our work not only features the first examination of STED with metallic clusters, but also reveals the significance of molecular transition dynamics when considering a STED labeling. PMID:26309767

  16. STRATOSPHERIC OZONE DEPLETION: A FOCUS ON EPA'S RESEARCH

    EPA Science Inventory

    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...

  17. In situ observations of bifurcation of equatorial ionospheric plasma depletions

    SciTech Connect

    Aggson, T.L.; Pfaff, R.F.; Maynard, N.C.

    1996-03-01

    Vector electric field measurements from the San Marco D satellite are utilized to investigate the bifurcation of ionospheric plasma depletions (sometimes called {open_quotes}bubbles{close_quotes}) associated with nightside equatorial spread F. These depletions are identified by enhanced upward ExB convection in depleted plasma density channels in the nighttime equatorial ionosphere. The in situ determination of the bifurcation process is based on dc electric field measurements of the bipolar variation in the zonal flow, westward and eastward, as the eastbound satellite crosses isolated signatures of updrafting plasma depletion regions. The authors also present data in which more complicated regions of zonal velocity variations appear as the possible result of multiple bifurcations of updrafting equatorial plasma bubbles. 10 refs., 7 fig.

  18. U.S. Geological Survey study on groundwater depletion

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2013-06-01

    The total depletion of groundwater in the United States from 1900 to 2008 was about 1000 cubic kilometers, more than twice the amount of water in Lake Erie, according to a 10 May report by the U.S. Geological Survey, Groundwater Depletion in the United States (1900-2008), that includes an evaluation of long-term cumulative depletion volumes in 40 separate aquifers in the United States. "This large volume of depletion represents a serious problem in the United States because much of this storage loss cannot be easily or quickly recovered and affects the sustainability of some critical water supplies and base flow to streams, among other effects," the report notes. For more information, see http://pubs.usgs.gov/sir/2013/5079/.

  19. Stimulated Emission Depletion Lithography with Mercapto-Functional Polymers

    PubMed Central

    2016-01-01

    Surface reactive nanostructures were fabricated using stimulated emission depletion (STED) lithography. The functionalization of the nanostructures was realized by copolymerization of a bifunctional metal oxo cluster in the presence of a triacrylate monomer. Ligands of the cluster surface cross-link to the monomer during the lithographic process, whereas unreacted mercapto functionalized ligands are transferred to the polymer and remain reactive after polymer formation of the surface of the nanostructure. The depletion efficiency in dependence of the cluster loading was investigated and full depletion of the STED effect was observed with a cluster loading exceeding 4 wt %. A feature size by λ/11 was achieved by using a donut-shaped depletion beam. The reactivity of the mercapto groups on the surface of the nanostructure was tested by incubation with mercapto-reactive fluorophores. PMID:26816204

  20. 10. VIEW OF DEPLETED URANIUM INGOT AND MOLD IN FOUNDRY. ...

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

    10. VIEW OF DEPLETED URANIUM INGOT AND MOLD IN FOUNDRY. (11/11/56) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO

  1. Effect of glutathione depletion on Ifosfamide nephrotoxicity in rats.

    PubMed

    Garimella-Krovi, Sudha; Springate, James E

    2008-09-01

    Kidney injury is an important side effect of the chemotherapeutic agent ifosfamide in humans. Previous studies have shown that treatment with ifosfamide reduces kidney glutathione and that the toxicity of ifosfamide is enhanced in glutathione-depleted renal tubule cells in vitro. In this study, we examined the effect of glutathione depletion on ifosfamide nephrotoxicity in vivo using rats treated with the glutathione-depleting agent buthionine sulfoximine. Animals received 80 mg/kg ifosfamide intraperitoneally daily for three days with or without buthionine sulfoximine in drinking water. Buthionine sulfoximine produced a significant fall in renal glutathione content but did not affect kidney function. Ifosfamide-treated rats developed low-grade glucosuria, phosphaturia and proteinuria that worsened with concomitant buthionine sulfoximine therapy. These findings indicate that glutathione depletion exacerbates ifosfamide nephrotoxicity in rats and suggest that pharmacological methods for replenishing intracellular glutathione may be effective in ameliorating ifosfamide-induced renal injury.

  2. Accelerated reabsorption in the proximal tubule produced by volume depletion.

    PubMed

    Weiner, M W; Weinman, E J; Kashgarian, M; Hayslett, J P

    1971-07-01

    The renal response to chronic depletion of extracellular volume was examined using the techniques of micropuncture. Depletion of salt and water was produced by administration of furosemide to rats maintained on a sodium-free diet. There was a marked fall in body weight, plasma volume, and glomerular filtration rate. The intrinsic reabsorptive capacity of the proximal tubule, measured by the split-droplet technique, was greatly enhanced. The acceleration of proximal fluid reabsorption could not be accounted for by changes in filtration rate, tubular geometry, or aldosterone secretion. The half-time of droplet reabsorption in the distal tubule was not altered by sodium depletion. An increase in the reabsorption of fluid in the proximal tubule, as demonstrated directly in the present experiments, provides an explanation for a variety of clinical phenomena associated with volume depletion.

  3. Retrieval of buried depleted uranium from the T-1 trench

    SciTech Connect

    Burmeister, M.; Castaneda, N.; Greengard, T. |; Hull, C.; Barbour, D.; Quapp, W.J.

    1998-07-01

    The Trench 1 remediation project will be conducted this year to retrieve depleted uranium and other associated materials from a trench at Rocky Flats Environmental Technology Site. The excavated materials will be segregated and stabilized for shipment. The depleted uranium will be treated at an offsite facility which utilizes a novel approach for waste minimization and disposal through utilization of a combination of uranium recycling and volume efficient uranium stabilization.

  4. Antioxidant Protection of NADPH-Depleted Oligodendrocyte Precursor Cells Is Dependent on Supply of Reduced Glutathione

    PubMed Central

    Kilanczyk, Ewa; Saraswat Ohri, Sujata; Whittemore, Scott R.

    2016-01-01

    The pentose phosphate pathway is the main source of NADPH, which by reducing oxidized glutathione, contributes to antioxidant defenses. Although oxidative stress plays a major role in white matter injury, significance of NADPH for oligodendrocyte survival has not been yet investigated. It is reported here that the NADPH antimetabolite 6-amino-NADP (6AN) was cytotoxic to cultured adult rat spinal cord oligodendrocyte precursor cells (OPCs) as well as OPC-derived oligodendrocytes. The 6AN-induced necrosis was preceded by increased production of superoxide, NADPH depletion, and lower supply of reduced glutathione. Moreover, survival of NADPH-depleted OPCs was improved by the antioxidant drug trolox. Such cells were also protected by physiological concentrations of the neurosteroid dehydroepiandrosterone (10−8 M). The protection by dehydroepiandrosterone was associated with restoration of reduced glutathione, but not NADPH, and was sensitive to inhibition of glutathione synthesis. A similar protective mechanism was engaged by the cAMP activator forskolin or the G protein-coupled estrogen receptor (GPER/GPR30) ligand G1. Finally, treatment with the glutathione precursor N-acetyl cysteine reduced cytotoxicity of 6AN. Taken together, NADPH is critical for survival of OPCs by supporting their antioxidant defenses. Consequently, injury-associated inhibition of the pentose phosphate pathway may be detrimental for the myelination or remyelination potential of the white matter. Conversely, steroid hormones and cAMP activators may promote survival of NADPH-deprived OPCs by increasing a NADPH-independent supply of reduced glutathione. Therefore, maintenance of glutathione homeostasis appears as a critical effector mechanism for OPC protection against NADPH depletion and preservation of the regenerative potential of the injured white matter. PMID:27449129

  5. Investigation of veritcal graded channel doping in nanoscale fully-depleted SOI-MOSFET

    NASA Astrophysics Data System (ADS)

    Ramezani, Zeinab; Orouji, Ali A.

    2016-10-01

    For achieving reliable transistor, we investigate an amended channel doping (ACD) engineering which improves the electrical and thermal performances of fully-depleted silicon-on-insulator (SOI) MOSFET. We have called the proposed structure with the amended channel doping engineering as ACD-SOI structure and compared it with a conventional fully-depleted SOI MOSFET (C-SOI) with uniform doping distribution using 2-D ATLAS simulator. The amended channel doping is a vertical graded doping that is distributed from the surface of structure with high doping density to the bottom of channel, near the buried oxide, with low doping density. Short channel effects (SCEs) and leakage current suppress due to high barrier height near the source region and electric field modification in the ACD-SOI in comparison with the C-SOI structure. Furthermore, by lower electric field and electron temperature near the drain region that is the place of hot carrier generation, we except the improvement of reliability and gate induced drain lowering (GIDL) in the proposed structure. Undesirable Self heating effect (SHE) that become a critical challenge for SOI MOSFETs is alleviated in the ACD-SOI structure because of utilizing low doping density near the buried oxide. Thus, refer to accessible results, the ACD-SOI structure with graded distribution in vertical direction is a reliable device especially in low power and high temperature applications.

  6. Intracellular energy depletion triggers programmed cell death during petal senescence in tulip

    PubMed Central

    Azad, A. K.; Ishikawa, Takayuki; Ishikawa, Takahiro; Shibata, H.

    2008-01-01

    Programmed cell death (PCD) in petals provides a model system to study the molecular aspects of organ senescence. In this study, the very early triggering signal for PCD during the senescence process from young green buds to 14-d-old petals of Tulipa gesneriana was determined. The opening and closing movement of petals of intact plants increased for the first 3 d and then gradually decreased. DNA degradation and cytochrome c (Cyt c) release were clearly observed in 6-d-old flowers. Oxidative stress or ethylene production can be excluded as the early signal for petal PCD. In contrast, ATP was dramatically depleted after the first day of flower opening. Sucrose supplementation to cut flowers maintained their ATP levels and the movement ability for a longer time than in those kept in water. The onset of DNA degradation, Cyt c release, and petal senescence was also delayed by sucrose supplementation to cut flowers. These results suggest that intracellular energy depletion, rather than oxidative stress or ethylene production, may be the very early signal to trigger PCD in tulip petals. PMID:18515833

  7. Rapid Degradation of the Tetrameric Mn Cluster in Illuminated, PsbO-Depleted Photosystem II Preparations

    SciTech Connect

    Semin, B. K.; Davletshina, L. N.; Ivanov, I. I.; Seibert, M.; Rubin, A. B.

    2012-01-01

    A 'decoupling effect' (light-induced electron transport without O{sub 2} evolution) was observed in Ca-depleted photosystem II (PSII(-Ca)) membranes, which lack PsbP and PsbQ (Semin et al. (2008) Photosynth. Res., 98, 235-249). Here PsbO-depleted PSII (PSII(-PsbO)) membranes (which also lack PsbP and PsbQ) were used to examine effects of PsbO on the decoupling. PSII(-PsbO) membranes do not reduce the acceptor 2,6-dichlorophenolindophenol (DCIP), in contrast to PSII(-Ca) membranes. To understand why DCIP reduction is lost, we studied light effects on the Mn content of PSII(-PsbO) samples and found that when they are first illuminated, Mn cations are rapidly released from the Mn cluster. Addition of an electron acceptor to PSII(-PsbO) samples accelerates the process. No effect of light was found on the Mn cluster in PSII(-Ca) membranes. Our results demonstrate that: (a) the oxidant, which directly oxidizes an as yet undefined substrate in PSII(-Ca) membranes, is the Mn cluster (not the Y{sub Z} radical or P680{sup +}); (b) light causes rapid release of Mn cations from the Mn cluster in PSII(-PsbO) membranes, and the mechanism is discussed; and (c) rapid degradation of the Mn cluster under illumination is significant for understanding the lack of functional activity in some PSII(-PsbO) samples reported by others.

  8. Intracellular energy depletion triggers programmed cell death during petal senescence in tulip.

    PubMed

    Azad, A K; Ishikawa, Takayuki; Ishikawa, Takahiro; Sawa, Y; Shibata, H

    2008-01-01

    Programmed cell death (PCD) in petals provides a model system to study the molecular aspects of organ senescence. In this study, the very early triggering signal for PCD during the senescence process from young green buds to 14-d-old petals of Tulipa gesneriana was determined. The opening and closing movement of petals of intact plants increased for the first 3 d and then gradually decreased. DNA degradation and cytochrome c (Cyt c) release were clearly observed in 6-d-old flowers. Oxidative stress or ethylene production can be excluded as the early signal for petal PCD. In contrast, ATP was dramatically depleted after the first day of flower opening. Sucrose supplementation to cut flowers maintained their ATP levels and the movement ability for a longer time than in those kept in water. The onset of DNA degradation, Cyt c release, and petal senescence was also delayed by sucrose supplementation to cut flowers. These results suggest that intracellular energy depletion, rather than oxidative stress or ethylene production, may be the very early signal to trigger PCD in tulip petals.

  9. Arginine depletion increases susceptibility to serious infections in preterm newborns

    PubMed Central

    Badurdeen, Shiraz; Mulongo, Musa; Berkley, James A.

    2015-01-01

    Preterm newborns are highly susceptible to bacterial infections. This susceptibility is regarded as being due to immaturity of multiple pathways of the immune system. However, it is unclear whether a mechanism that unifies these different, suppressed pathways exists. Here, we argue that the immune vulnerability of the preterm neonate is critically related to arginine depletion. Arginine, a “conditionally essential” amino acid, is depleted in acute catabolic states, including sepsis. Its metabolism is highly compartmentalized and regulated, including by arginase-mediated hydrolysis. Recent data suggest that arginase II-mediated arginine depletion is essential for the innate immune suppression that occurs in newborn models of bacterial challenge, impairing pathways critical for the immune response. Evidence that arginine depletion mediates protection from immune activation during first gut colonization suggests a regulatory role in controlling gut-derived pathogens. Clinical studies show that plasma arginine is depleted during sepsis. In keeping with animal studies, small clinical trials of L-arginine supplementation have shown benefit in reducing necrotizing enterocolitis in premature neonates. We propose a novel, broader hypothesis that arginine depletion during bacterial challenge is a key factor limiting the neonate's ability to mount an adequate immune response, contributing to the increased susceptibility to infections, particularly with respect to gut-derived sepsis. PMID:25360828

  10. Depletion optimization of lumped burnable poisons in pressurized water reactors

    SciTech Connect

    Kodah, Z.H.

    1982-01-01

    Techniques were developed to construct a set of basic poison depletion curves which deplete in a monotonical manner. These curves were combined to match a required optimized depletion profile by utilizing either linear or non-linear programming methods. Three computer codes, LEOPARD, XSDRN, and EXTERMINATOR-2 were used in the analyses. A depletion routine was developed and incorporated into the XSDRN code to allow the depletion of fuel, fission products, and burnable poisons. The Three Mile Island Unit-1 reactor core was used in this work as a typical PWR core. Two fundamental burnable poison rod designs were studied. They are a solid cylindrical poison rod and an annular cylindrical poison rod with water filling the central region.These two designs have either a uniform mixture of burnable poisons or lumped spheroids of burnable poisons in the poison region. Boron and gadolinium are the two burnable poisons which were investigated in this project. Thermal self-shielding factor calculations for solid and annular poison rods were conducted. Also expressions for overall thermal self-shielding factors for one or more than one size group of poison spheroids inside solid and annular poison rods were derived and studied. Poison spheroids deplete at a slower rate than the poison mixture because each spheroid exhibits some self-shielding effects of its own. The larger the spheroid, the higher the self-shielding effects due to the increase in poison concentration.

  11. Inositol depletion restores vesicle transport in yeast phospholipid flippase mutants.

    PubMed

    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.

  12. Genetics Home Reference: MPV17-related hepatocerebral mitochondrial DNA depletion syndrome

    MedlinePlus

    ... mitochondrial DNA depletion syndrome MPV17-related hepatocerebral mitochondrial DNA depletion syndrome Enable Javascript to view the expand/ ... All Close All Description MPV17 -related hepatocerebral mitochondrial DNA depletion syndrome is an inherited disorder that can ...

  13. Genetics Home Reference: TK2-related mitochondrial DNA depletion syndrome, myopathic form

    MedlinePlus

    ... DNA depletion syndrome, myopathic form TK2-related mitochondrial DNA depletion syndrome, myopathic form Enable Javascript to view ... Open All Close All Description TK2 -related mitochondrial DNA depletion syndrome, myopathic form ( TK2 -MDS) is an ...

  14. 77 FR 53236 - Proposed International Isotopes Fluorine Extraction Process and Depleted Uranium Deconversion...

    Federal Register 2010, 2011, 2012, 2013, 2014

    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...

  15. Metallothionein deficiency aggravates depleted uranium-induced nephrotoxicity

    SciTech Connect

    Hao, Yuhui; Huang, Jiawei; Gu, Ying; Liu, Cong; Li, Hong; Liu, Jing; Ren, Jiong; Yang, Zhangyou; Peng, Shuangqing; Wang, Weidong; Li, Rong

    2015-09-15

    Depleted uranium (DU) has been widely used in both civilian and military activities, and the kidney is the main target organ of DU during acute high-dose exposures. In this study, the nephrotoxicity caused by DU in metallothionein-1/2-null mice (MT −/−) and corresponding wild-type (MT +/+) mice was investigated to determine any associations with MT. Each MT −/− or MT +/+ mouse was pretreated with a single dose of DU (10 mg/kg, intraperitoneal injection) or an equivalent volume of saline. After 4 days of DU administration, kidney changes were assessed. After DU exposure, serum creatinine and serum urea nitrogen in MT −/− mice significantly increased than in MT +/+ mice, with more severe kidney pathological damage. Moreover, catalase and superoxide dismutase (SOD) decreased, and generation of reactive oxygen species and malondialdehyde increased in MT −/− mice. The apoptosis rate in MT −/− mice significantly increased, with a significant increase in both Bax and caspase 3 and a decrease in Bcl-2. Furthermore, sodium-glucose cotransporter (SGLT) and sodium-phosphate cotransporter (NaPi-II) were significantly reduced after DU exposure, and the change of SGLT was more evident in MT −/− mice. Finally, exogenous MT was used to evaluate the correlation between kidney changes induced by DU and MT doses in MT −/− mice. The results showed that, the pathological damage and cell apoptosis decreased, and SOD and SGLT levels increased with increasing dose of MT. In conclusion, MT deficiency aggravated DU-induced nephrotoxicity, and the molecular mechanisms appeared to be related to the increased oxidative stress and apoptosis, and decreased SGLT expression. - Highlights: • MT −/− and MT +/+ mice were used to evaluate nephrotoxicity of DU. • Renal damage was more evident in the MT −/− mice after exposure to DU. • Exogenous MT also protects against DU-induced nephrotoxicity. • MT deficiency induced more ROS and apoptosis after exposure to

  16. Ego depletion decreases trust in economic decision making

    PubMed Central

    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

  17. Coordinated airborne and satellite measurements of equatorial plasma depletions

    SciTech Connect

    Weber, E.J.; Brinton, H.C.; Buchau, J.; Moore, J.G.

    1982-12-01

    A series of experiments was conducted in December 1979 to investigate the structure of plasma depletions in the low latitude, nightime ionosphere. The measurements included all sky imaging photometer (ASIP), ionosonde and amplitude scintillation observations from the AFGL Airborne Ionospheric Observatory (AIO), and in situ ion density measurements from the Atmosphere Explorer (AE-E) Bennett Ion Mass Spectrometer (BIMS). The AIO performed two flights along the Ascension Island (-18/sup 0/ MLAT) magnetic meridian: one in the southern hemisphere and one near the Ascension conjugate point in the northern hemisphere. During these flights, measurements from the AE-E satellite at 434 km altitude are compared with simultaneous remote ionospheric measurements from the AIO. Density biteouts of approximately one order of magnitude in the dominant ion O/sup +/, were mapped to lower altitudes along magnetic field lines for comparison with 6300-A and 7774-A O I airglow depletions. Because of the different airglow production mechanisms (dissociative recombination of O/sup +//sub 2/ for 6300 A and radiative recombination of O/sup +/ for 7774 A) the 6300-A depletions reflect plasma depletions near the bottomside of the F layer, while those at 7774 A are located near the peak of the layer. The O/sup +/ biteouts map directly into the 7774-A airglow depletions in the same hemisphere and also when traced into the opposite hemisphere, which indicates magnetic flux tube alignment over north-south distances of approx.2220 km. The 6300-A (bottomside) depletions are wider in longitude than the 7774-A (F-peak) depletions near the equatorward edge of the Appleton anomaly. This difference in topside and bottomside structure is used to infer large-scale structure near the anomaly and to relate this to structure, commonly observed near the magnetic equator by the ALTAIR radar.

  18. Microanalytical X-ray imaging of depleted uranium speciation in environmentally aged munitions residues.

    PubMed

    Crean, Daniel E; Livens, Francis R; Stennett, Martin C; Grolimund, Daniel; Borca, Camelia N; Hyatt, Neil C

    2014-01-01

    Use of depleted uranium (DU) munitions has resulted in contamination of the near-surface environment with penetrator residues. Uncertainty in the long-term environmental fate of particles produced by impact of DU penetrators with hard targets is a specific concern. In this study DU particles produced in this way and exposed to the surface terrestrial environment for longer than 30 years at a U.K. firing range were characterized using synchrotron X-ray chemical imaging. Two sites were sampled: a surface soil and a disposal area for DU-contaminated wood, and the U speciation was different between the two areas. Surface soil particles showed little extent of alteration, with U speciated as oxides U3O7 and U3O8. Uranium oxidation state and crystalline phase mapping revealed these oxides occur as separate particles, reflecting heterogeneous formation conditions. Particles recovered from the disposal area were substantially weathered, and U(VI) phosphate phases such as meta-ankoleite (K(UO2)(PO4) · 3H2O) were dominant. Chemical imaging revealed domains of contrasting U oxidation state linked to the presence of both U3O7 and meta-ankoleite, indicating growth of a particle alteration layer. This study demonstrates that substantial alteration of DU residues can occur, which directly influences the health and environmental hazards posed by this contamination. PMID:24451034

  19. Measures of antioxidant status of the horse in response to selenium depletion and repletion.

    PubMed

    Brummer, M; Hayes, S; Dawson, K A; Lawrence, L M

    2013-05-01

    Selenium plays a role in the antioxidant mechanism via the selenoenzyme glutathione peroxidase (GSH-Px). Change in Se status because of Se depletion or supplementation is associated with a change in GSH-Px activity and could potentially affect antioxidant status. This study evaluated the impact of change in Se status on measures of antioxidant status and oxidative stress in adult horses. Twenty-eight horses were blocked by age and gender and were randomly allocated to 1 of 4 dietary treatment groups: low Se (LS), adequate Se (AS), high organic Se (SP), and high inorganic Se (SS). For 196 d, LS, SP, and SS received a low-Se diet (0.06 mg Se/kg DM) to allow for depletion of Se stores, whereas AS received an adequate Se diet (0.12 mg Se/kg DM). Then, for the next 189 d, LS and AS were maintained on the same diets, whereas SP was supplemented with Se-yeast and SS with sodium selenite to allow for a total dietary Se intake of 0.3 mg Se/kg DM. Blood samples were collected throughout the study. Variables of interest included whole blood Se and GSH-Px activity, serum vitamin E concentration, total antioxidant capacity (TAC), serum malondialdehyde (MDA), and triiodothyronine and thyroxine concentrations. Data were analyzed using ANOVA with repeated measures. Whole blood Se and GSH-Px activity decreased in LS, SP, and SS during the depletion phase and increased in SP and SS with supplementation (treatment × time, P < 0.001). At the conclusion of the supplementation period, GSH-Px activity was greater in SP and SS compared with AS and LS (P < 0.05). Vitamin E status remained adequate throughout the study, and no differences existed between treatments. Serum TAC did not change in response to Se depletion or repletion. Serum MDA was greater for AS than LS during depletion (P < 0.05) but similar across treatments after supplementation. Overall, change in Se status did not have a large impact on TAC or MDA, possibly because the horses maintained an adequate vitamin E status

  20. Dynamics of spinal microglia repopulation following an acute depletion.

    PubMed

    Yao, Yao; Echeverry, Stefania; Shi, Xiang Qun; Yang, Mu; Yang, Qiu Zi; Wang, Guan Yun Frances; Chambon, Julien; Wu, Yi Chen; Fu, Kai Yuan; De Koninck, Yves; Zhang, Ji

    2016-01-01

    Our understanding on the function of microglia has been revolutionized in the recent 20 years. However, the process of maintaining microglia homeostasis has not been fully understood. In this study, we dissected the features of spinal microglia repopulation following an acute partial depletion. By injecting intrathecally Mac-1-saporin, a microglia selective immunotoxin, we ablated 50% microglia in the spinal cord of naive mice. Spinal microglia repopulated rapidly and local homeostasis was re-established within 14 days post-depletion. Mac-1-saporin treatment resulted in microglia cell proliferation and circulating monocyte infiltration. The latter is indeed part of an acute, transient inflammatory reaction that follows cell depletion, and was characterized by an increase in the expression of inflammatory molecules and by the breakdown of the blood spinal cord barrier. During this period, microglia formed cell clusters and exhibited a M1-like phenotype. MCP-1/CCR2 signaling was essential in promoting this depletion associated spinal inflammatory reaction. Interestingly, ruling out MCP-1-mediated secondary inflammation, including blocking recruitment of monocyte-derived microglia, did not affect depletion-triggered microglia repopulation. Our results also demonstrated that newly generated microglia kept their responsiveness to peripheral nerve injury and their contribution to injury-associated neuropathic pain was not significantly altered. PMID:26961247

  1. Stream depletion in alluvial valleys using the SDF semianalytical model.

    PubMed

    Miller, Calvin D; Durnford, Deanna; Halstead, Mary R; Altenhofen, Jon; Flory, Val

    2007-01-01

    A semianalytical method commonly used for quantifying stream depletion caused by ground water pumping was reviewed for applicability in narrow alluvial aquifers. This stream depletion factor (SDF) method is based on the analytic Glover model, but uses a numerical model-derived input parameter, called the SDF, to partly account for mathematically nonideal conditions such as variable transmissivity and nearby aquifer boundaries. Using the SDF can improve and simplify depletion estimates. However, the method's approximations introduce error that increases with proximity to the impermeable aquifer boundary. This article reviews the history of the method and its assumptions. New stream depletion response curves are presented as functions of well position within bounded aquifers. A simple modification to modeled SDF values is proposed that allows the impermeable boundary to be accounted for with image wells, but without overaccounting for boundary effects that are already reflected in modeled SDFs. It is shown that SDFs for locations closer to the river than to the aquifer boundary do not reflect impermeable-boundary effects, and thus need no modification, and boundary effects in the other portion of the aquifer follow a predictable removable pattern. This method is verified by comparing response curves using modified SDFs with response curves from an extensively calibrated numerical model of a managed ground water recharge site. The modification improves SDF-based stream depletion estimates in bounded aquifers while still benefiting from the additional information contained in SDF maps and retaining their value as standardized references for water rights administration.

  2. Recovery of the Ozone Layer: The Ozone Depleting Gas Index

    NASA Astrophysics Data System (ADS)

    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?

  3. Reentrant phase transitions from depletion: colloidal crystals to flocculation

    NASA Astrophysics Data System (ADS)

    Feng, Lang; Laderman, Bezia; Sacanna, Stefano; Chaikin, Paul

    2014-03-01

    Conventional depletion is supposed to be temperature independent. However, we find that many typical colloid-depletion systems show remarkable phenomena as temperature is varied. 1 μm polystyrene spheres in water are known to form colloidal crystals when PEO is added as a depletant. When this system is heated the crystal melts at a first critical temperature T1 ~ 60 C , and then at higher temperature T2 ~ 70 C the colloids flocculate. We argue that a weak temperature-dependent interaction between polymer and colloid is responsible for the observed phenomena: crystals form when the colloid-polymer interaction is repulsive, flocculation occurs when the interaction is attractive, and melting occurs in between when both phases are frustrated. The melted phase occurs due to an unexpected cancelation when combining both entropic and enthalpic attractions. We propose a simple statistical model to map out the observed transitions and fill the theoretical gap between the two established scenarios for colloid-polymer systems, namely depletion and flocculation. We have seen the same temperature dependent phenomena for TPM, PS and silica spheres with PEO and dextran as depletants. Our discovery provides a fundamental understanding of the polymer-colloid system and opens new possibilities for colloidal self-assembly and temperature-controlled viscoelastic materials.

  4. Global Depletion of Groundwater Resources: Past and Future Analyses

    NASA Astrophysics Data System (ADS)

    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.

  5. ALEPH2 - A general purpose Monte Carlo depletion code

    SciTech Connect

    Stankovskiy, A.; Van Den Eynde, G.; Baeten, P.; Trakas, C.; Demy, P. M.; Villatte, L.

    2012-07-01

    The Monte-Carlo burn-up code ALEPH is being developed at SCK-CEN since 2004. A previous version of the code implemented the coupling between the Monte Carlo transport (any version of MCNP or MCNPX) and the ' deterministic' depletion code ORIGEN-2.2 but had important deficiencies in nuclear data treatment and limitations inherent to ORIGEN-2.2. A new version of the code, ALEPH2, has several unique features making it outstanding among other depletion codes. The most important feature is full data consistency between steady-state Monte Carlo and time-dependent depletion calculations. The last generation general-purpose nuclear data libraries (JEFF-3.1.1, ENDF/B-VII and JENDL-4) are fully implemented, including special purpose activation, spontaneous fission, fission product yield and radioactive decay data. The built-in depletion algorithm allows to eliminate the uncertainties associated with obtaining the time-dependent nuclide concentrations. A predictor-corrector mechanism, calculation of nuclear heating, calculation of decay heat, decay neutron sources are available as well. The validation of the code on the results of REBUS experimental program has been performed. The ALEPH2 has shown better agreement with measured data than other depletion codes. (authors)

  6. Dynamics of spinal microglia repopulation following an acute depletion

    PubMed Central

    Yao, Yao; Echeverry, Stefania; Shi, Xiang Qun; Yang, Mu; Yang, Qiu Zi; Wang, Guan Yun Frances; Chambon, Julien; Wu, Yi Chen; Fu, Kai Yuan; De Koninck, Yves; Zhang, Ji

    2016-01-01

    Our understanding on the function of microglia has been revolutionized in the recent 20 years. However, the process of maintaining microglia homeostasis has not been fully understood. In this study, we dissected the features of spinal microglia repopulation following an acute partial depletion. By injecting intrathecally Mac-1-saporin, a microglia selective immunotoxin, we ablated 50% microglia in the spinal cord of naive mice. Spinal microglia repopulated rapidly and local homeostasis was re-established within 14 days post-depletion. Mac-1-saporin treatment resulted in microglia cell proliferation and circulating monocyte infiltration. The latter is indeed part of an acute, transient inflammatory reaction that follows cell depletion, and was characterized by an increase in the expression of inflammatory molecules and by the breakdown of the blood spinal cord barrier. During this period, microglia formed cell clusters and exhibited a M1-like phenotype. MCP-1/CCR2 signaling was essential in promoting this depletion associated spinal inflammatory reaction. Interestingly, ruling out MCP-1-mediated secondary inflammation, including blocking recruitment of monocyte-derived microglia, did not affect depletion-triggered microglia repopulation. Our results also demonstrated that newly generated microglia kept their responsiveness to peripheral nerve injury and their contribution to injury-associated neuropathic pain was not significantly altered. PMID:26961247

  7. Metabolic Response to NAD Depletion across Cell Lines Is Highly Variable

    PubMed Central

    Xiao, Yang; Kwong, Mandy; Daemen, Anneleen; Belvin, Marcia; Liang, Xiaorong; Hatzivassiliou, Georgia

    2016-01-01

    Nicotinamide adenine dinucleotide (NAD) is a cofactor involved in a wide range of cellular metabolic processes and is a key metabolite required for tumor growth. NAMPT, nicotinamide phosphoribosyltransferase, which converts nicotinamide (NAM) to nicotinamide mononucleotide (NMN), the immediate precursor of NAD, is an attractive therapeutic target as inhibition of NAMPT reduces cellular NAD levels and inhibits tumor growth in vivo. However, there is limited understanding of the metabolic response to NAD depletion across cancer cell lines and whether all cell lines respond in a uniform manner. To explore this we selected two non-small cell lung carcinoma cell lines that are sensitive to the NAMPT inhibitor GNE-617 (A549, NCI-H1334), one that shows intermediate sensitivity (NCI-H441), and one that is insensitive (LC-KJ). Even though NAD was reduced in all cell lines there was surprising heterogeneity in their metabolic response. Both sensitive cell lines reduced glycolysis and levels of di- and tri-nucleotides and modestly increased oxidative phosphorylation, but they differed in their ability to combat oxidative stress. H1334 cells activated the stress kinase AMPK, whereas A549 cells were unable to activate AMPK as they contain a mutation in LKB1, which prevents activation of AMPK. However, A549 cells increased utilization of the Pentose Phosphate pathway (PPP) and had lower reactive oxygen species (ROS) levels than H1334 cells, indicating that A549 cells are better able to modulate an increase in oxidative stress. Inherent resistance of LC-KJ cells is associated with higher baseline levels of NADPH and a delayed reduction of NAD upon NAMPT inhibition. Our data reveals that cell lines show heterogeneous response to NAD depletion and that the underlying molecular and genetic framework in cells can influence the metabolic response to NAMPT inhibition. PMID:27711204

  8. Tuning of depletion interaction in nanoparticle-surfactant systems

    SciTech Connect

    Ray, D. Aswal, V. K.

    2014-04-24

    The interaction of anionic silica nanoparticles (Ludox LS30) and non-ionic surfactants decaethylene glycol monododecylether (C12E10) without and with anionic sodium dodecyl sulfate (SDS) in aqueous electrolyte solution has been studied by small-angle neutron scattering (SANS). The measurements have been carried out for fixed concentrations of nanoparticle (1 wt%), surfactants (1 wt%) and electrolyte (0.1 M NaCl). Each of these nanoparticlesurfactant systems has been examined for different contrast conditions where individual components (nanoparticle or surfactant) are made visible. It is observed that the nanoparticle-C12E10 system leads to the depletion-induced aggregation of nanoparticles. The system however behaves very differently on addition of SDS where depletion interaction gets suppressed and aggregation of nanoparticles can be prevented. We show that C12E10 and SDS form mixed micelles and the charge on these micelles plays important role in tuning the depletion interaction.

  9. International aspects of restrictions of ozone-depleting substances

    SciTech Connect

    McDonald, S.C.

    1989-10-01

    This report summarizes international efforts to protect stratospheric ozone. Also included in this report is a discussion of activities in other countries to meet restrictions in the production and use of ozone-depleting substances. Finally, there is a brief presentation of trade and international competitiveness issues relating to the transition to alternatives for the regulated chlorofluorocarbons (CFCs) and halons. The stratosphere knows no international borders. Just as the impact of reduced stratospheric ozone will be felt internationally, so protection of the ozone layer is properly an international effort. Unilateral action, even by a country that produces and used large quantities of ozone-depleting substances, will not remedy the problem of ozone depletion if other countries do not follow suit. 32 refs., 7 tabs.

  10. Programmable nanometer-scale electrolytic metal deposition and depletion

    DOEpatents

    Lee, James Weifu [Oak Ridge, TN; Greenbaum, Elias [Oak Ridge, TN

    2002-09-10

    A method of nanometer-scale deposition of a metal onto a nanostructure includes the steps of: providing a substrate having thereon at least two electrically conductive nanostructures spaced no more than about 50 .mu.m apart; and depositing metal on at least one of the nanostructures by electric field-directed, programmable, pulsed electrolytic metal deposition. Moreover, a method of nanometer-scale depletion of a metal from a nanostructure includes the steps of providing a substrate having thereon at least two electrically conductive nanostructures spaced no more than about 50 .mu.m apart, at least one of the nanostructures having a metal disposed thereon; and depleting at least a portion of the metal from the nanostructure by electric field-directed, programmable, pulsed electrolytic metal depletion. A bypass circuit enables ultra-finely controlled deposition.

  11. Effect of Shim Arm Depletion in the NBSR

    SciTech Connect

    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.

  12. Tunable depletion potentials driven by shape variation of surfactant micelles

    NASA Astrophysics Data System (ADS)

    Gratale, Matthew D.; Still, Tim; Matyas, Caitlin; Davidson, Zoey S.; Lobel, Samuel; Collings, Peter J.; Yodh, A. G.

    2016-05-01

    Depletion interaction potentials between micron-sized colloidal particles are induced by nanometer-scale surfactant micelles composed of hexaethylene glycol monododecyl ether (C12E6 ), and they are measured by video microscopy. The strength and range of the depletion interaction is revealed to arise from variations in shape anisotropy of the surfactant micelles. This shape anisotropy increases with increasing sample temperature. By fitting the colloidal interaction potentials to theoretical models, we extract micelle length and shape anisotropy as a function of temperature. This work introduces shape anisotropy tuning as a means to control interparticle interactions in colloidal suspensions, and it shows how the interparticle depletion potentials of micron-scale objects can be employed to probe the shape and size of surrounding macromolecules at the nanoscale.

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

    PubMed Central

    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

  14. Coherent quantum depletion of an interacting atom condensate

    PubMed Central

    Kira, M.

    2015-01-01

    Sufficiently strong interactions promote coherent quantum transitions in spite of thermalization and losses, which are the adversaries of delicate effects such as reversibility and correlations. In atomic Bose–Einstein condensates (BECs), strong atom–atom interactions can eject atoms from the BEC to the normal component, yielding quantum depletion instead of temperature depletion. A recent experiment has already been verified to overcome losses. Here I show that it also achieves coherent quantum-depletion dynamics in a BEC swept fast enough from weak to strong atom–atom interactions. The elementary coherent process first excites the normal component into a liquid state that evolves into a spherical shell state, where the atom occupation peaks at a finite momentum to shield 50% of the BEC atoms from annihilation. The identified coherent processes resemble ultrafast semiconductor excitations expanding the scope of BEC explorations to many-body non-equilibrium studies. PMID:25767044

  15. Depleted uranium as a backfill for nuclear fuel waste package

    DOEpatents

    Forsberg, C.W.

    1998-11-03

    A method is described for packaging spent nuclear fuel for long-term disposal in a geological repository. At least one spent nuclear fuel assembly is first placed in an unsealed waste package and a depleted uranium fill material is added to the waste package. The depleted uranium fill material comprises flowable particles having a size sufficient to substantially fill any voids in and around the assembly and contains isotopically-depleted uranium in the +4 valence state in an amount sufficient to inhibit dissolution of the spent nuclear fuel from the assembly into a surrounding medium and to lessen the potential for nuclear criticality inside the repository in the event of failure of the waste package. Last, the waste package is sealed, thereby substantially reducing the release of radionuclides into the surrounding medium, while simultaneously providing radiation shielding and increased structural integrity of the waste package. 6 figs.

  16. Depleted uranium as a backfill for nuclear fuel waste package

    DOEpatents

    Forsberg, Charles W.

    1998-01-01

    A method for packaging spent nuclear fuel for long-term disposal in a geological repository. At least one spent nuclear fuel assembly is first placed in an unsealed waste package and a depleted uranium fill material is added to the waste package. The depleted uranium fill material comprises flowable particles having a size sufficient to substantially fill any voids in and around the assembly and contains isotopically-depleted uranium in the +4 valence state in an amount sufficient to inhibit dissolution of the spent nuclear fuel from the assembly into a surrounding medium and to lessen the potential for nuclear criticality inside the repository in the event of failure of the waste package. Last, the waste package is sealed, thereby substantially reducing the release of radionuclides into the surrounding medium, while simultaneously providing radiation shielding and increased structural integrity of the waste package.

  17. Observations of ozone depletion associated with solar proton events

    NASA Technical Reports Server (NTRS)

    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.

  18. Coherent quantum depletion of an interacting atom condensate.

    PubMed

    Kira, M

    2015-03-13

    Sufficiently strong interactions promote coherent quantum transitions in spite of thermalization and losses, which are the adversaries of delicate effects such as reversibility and correlations. In atomic Bose-Einstein condensates (BECs), strong atom-atom interactions can eject atoms from the BEC to the normal component, yielding quantum depletion instead of temperature depletion. A recent experiment has already been verified to overcome losses. Here I show that it also achieves coherent quantum-depletion dynamics in a BEC swept fast enough from weak to strong atom-atom interactions. The elementary coherent process first excites the normal component into a liquid state that evolves into a spherical shell state, where the atom occupation peaks at a finite momentum to shield 50% of the BEC atoms from annihilation. The identified coherent processes resemble ultrafast semiconductor excitations expanding the scope of BEC explorations to many-body non-equilibrium studies.

  19. Transcriptome analysis of human OXR1 depleted cells reveals its role in regulating the p53 signaling pathway

    PubMed Central

    Yang, Mingyi; Lin, Xiaolin; Rowe, Alexander; Rognes, Torbjørn; Eide, Lars; Bjørås, Magnar

    2015-01-01

    The oxidation resistance gene 1 (OXR1) is crucial for protecting against oxidative stress; however, its molecular function is unknown. We employed RNA sequencing to examine the role of human OXR1 for genome wide transcription regulation. In total, in non-treated and hydrogen peroxide exposed HeLa cells, OXR1 depletion resulted in down-regulation of 554 genes and up-regulation of 253 genes. These differentially expressed genes include transcription factors (i.e. HIF1A, SP6, E2F8 and TCF3), antioxidant genes (PRDX4, PTGS1 and CYGB) and numerous genes of the p53 signaling pathway involved in cell-cycle arrest (i.e. cyclin D, CDK6 and RPRM) and apoptosis (i.e. CytC and CASP9). We demonstrated that OXR1 depleted cells undergo cell cycle arrest in G2/M phase during oxidative stress and increase protein expression of the apoptosis initiator protease CASP9. In summary, OXR1 may act as a sensor of cellular oxidative stress to regulate the transcriptional networks required to detoxify reactive oxygen species and modulate cell cycle and apoptosis. PMID:26616534

  20. Partial Depletion of Gamma-Actin Suppresses Microtubule Dynamics

    PubMed Central

    Po'uha, Sela T; Honore, Stephane; Braguer, Diane; Kavallaris, Maria

    2013-01-01

    Actin and microtubule interactions are important for many cellular events, however these interactions are poorly described. Alterations in γ-actin are associated with diseases such as hearing loss and cancer. Functional investigations demonstrated that partial depletion of γ-actin affects cell polarity and induces resistance to microtubule-targeted agents. To determine whether γ-actin alterations directly affect microtubule dynamics, microtubule dynamic instability was analyzed in living cells following partial siRNA depletion of γ-actin. Partial depletion of γ-actin suppresses interphase microtubule dynamics by 17.5% due to a decrease in microtubule shortening rates and an increase in microtubule attenuation. γ-Actin partial depletion also increased distance-based microtubule catastrophe and rescue frequencies. In addition, knockdown of γ-actin delayed mitotic progression, partially blocking metaphase–anaphase transition and inhibiting cell proliferation. Interestingly, in the presence of paclitaxel, interphase microtubule dynamics were further suppressed by 24.4% in the γ-actin knockdown cells, which is comparable to 28.8% suppression observed in the control siRNA treated cells. Paclitaxel blocked metaphase–anaphase transition in both the γ-actin knockdown cells and the control siRNA cells. However, the extent of mitotic arrest was much higher in the control cells (28.4%), compared to the γ-actin depleted cells (8.5%). Therefore, suppression of microtubule dynamics by partial depletion of γ-actin is associated with marked delays in metaphase-anaphase transition and not mitotic arrest. This is the first demonstration that γ-actin can modulate microtubule dynamics by reducing the microtubule shortening rate, promoting paused/attenuated microtubules, and increasing transition frequencies suggesting a mechanistic link between γ-actin and microtubules. © 2013 Wiley Periodicals, Inc PMID:23335583

  1. Striatal serotonin depletion facilitates rat egocentric learning via dopamine modulation.

    PubMed

    Anguiano-Rodríguez, Patricia B; Gaytán-Tocavén, Lorena; Olvera-Cortés, María Esther

    2007-02-01

    Egocentric spatial learning has been defined as the ability to navigate in an environment using only proprioceptive information, thereby performing a motor response based on one's own movement. This form of learning has been associated with the neural memory system, including the striatum body. Cerebral serotonin depletion induces better performance, both in tasks with strong egocentric components and in egocentric navigation in the Morris' maze. Based on this, we propose that the striatal serotonergic depletion must facilitate egocentric learning. Fifteen female Sprague Dawley rats weighing 250-350 g and maintained under standard conditions were chronically implanted with infusion cannulas for bilateral application of drugs into the striatum. The animals were evaluated for egocentric navigation using the Morris' maze, under different conditions: saline solution infusion, serotonin depletion by infusion of 5,7-Dihydroxytryptamine (25 microg of free base solved in 2.5 microl of ascorbic acid 1% in saline solution), infusion of mixed dopamine D(1) and D(2) receptor antagonists (0.5 microl/min during 5 min of mixed spiperone 20 microM and SCH23390 10 microM), or serotonin depletion and dopamine blockade simultaneously. Striatal serotonin depletion facilitated egocentric learning, which was demonstrated as shorter escape latencies and the display of a defined sequence of movements for reaching the platform. The facilitation was not observed under condition of simultaneous dopamine blockade. Striatal serotonin depletion produced a dopamine-dependent facilitation of egocentric learning. A role for serotonin in the inhibition of striatal-mediated learning strategies is proposed. PMID:17126827

  2. Methionine depletion modulates the antitumor and antimetastatic efficacy of ethionine.

    PubMed

    Guo, H; Tan, Y; Kubota, T; Moossa, A R; Hoffman, R M

    1996-01-01

    The elevated methionine requirement for the growth of tumors, termed methionine dependence, is a potentially highly effective therapeutic target. To attack this target we are developing anti-methionine chemotherapy. In this study of anti-methionine chemotherapy we have observed that the methionine analog ethionine is synergistic with methionine depletion in arresting the growth of the Yoshida sarcoma both in vitro and when transplanted to nude mice. In contrast, ethionine in vitro in a methionine-containing medium is not effective against Yoshida sarcoma cells. Similarly, ethionine administered along with a methionine-containing diet is ineffective against the Yoshida sarcoma growing in nude mice. A methionine-depleted diet alone is only partially effective against tumor growth. The Yoshida sarcoma gave rise to metastases in 75% of the- organs observed in the mice on the methionine-containing diet, and 43 % of the organs in the mice on the methionine-free diet. In striking contrast, no metastases were observed in the ethionine-treated animals on the methionine-free diet. Anti-methionine chemotherapy consisting of dietary methionine depletion and ethionine administration caused an initial weight loss but the animals weight stabilized resulting in no animal deaths. The synergism of ethionine and methionine depletion is markedly similar in vitro and in vivo suggesting the observed efficacy is due to the specific anti-methionine targeting. Thus methionine depletion highly potentiates the anti-tumor and anti-metastatic effectiveness of ethionine suggesting that anti-methionine chemotherapy consisting of methionine depletion as a modulator of methionine analogs holds great promise as a new, tumor-selective therapeutic approach.

  3. Apoptosis and T-cell depletion during feline infectious peritonitis.

    PubMed

    Haagmans, B L; Egberink, H F; Horzinek, M C

    1996-12-01

    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 activated T cells. Since feline infectious peritonitis virus does not infect T cells, and viral proteins did not inhibit T-cell proliferation, we postulate that soluble mediators released during the infection cause apoptosis and T-cell depletion.

  4. Choice and ego-depletion: the moderating role of autonomy.

    PubMed

    Moller, Arlen C; Deci, Edward L; Ryan, Richard M

    2006-08-01

    The self-regulatory strength model maintains that all acts of self-regulation, self-control, and choice result in a state of fatigue called ego-depletion. Self-determination theory differentiates between autonomous regulation and controlled regulation. Because making decisions represents one instance of self-regulation, the authors also differentiate between autonomous choice and controlled choice. Three experiments support the hypothesis that whereas conditions representing controlled choice would be egodepleting, conditions that represented autonomous choice would not. In Experiment 3, the authors found significant mediation by perceived self-determination of the relation between the choice condition (autonomous vs. controlled) and ego-depletion as measured by performance.

  5. Role of Nucleonic Fermi Surface Depletion in Neutron Star Cooling

    NASA Astrophysics Data System (ADS)

    Dong, J. M.; Lombardo, U.; Zhang, H. F.; Zuo, W.

    2016-01-01

    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 3PF2 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.

  6. Developing depleted uranium and gold cocktail hohlraums for the National Ignition Facilitya)

    NASA Astrophysics Data System (ADS)

    Wilkens, H. L.; Nikroo, A.; Wall, D. R.; Wall, J. R.

    2007-05-01

    Fusion ignition experiments are planned to begin at the National Ignition Facility (NIF) [J. A. Paisner, E. M. Campbell, and W. J. Hogan, Fusion Technol. 26, 755 (1994)] using the indirect drive configuration [J. D. Lindl, P. Amendt, R. L. Berger, S. G. Glendinning, S. H. Glenzer, S. W. Haan, R. L, Kauffman, O. L. Landen, and L. J. Suter, Phys. Plasmas 11, 339 (2004)]. Although the x-ray drive in this configuration is highly symmetric, energy is lost in the conversion process due to x-ray penetration into the hohlraum wall. To mitigate this loss, depleted uranium is incorporated into the traditional gold hohlraum to increase the efficiency of the laser to x-ray energy conversion by making the wall more opaque to the x rays [H. Nishumura, T. Endo, H. Shiraga, U. Kato, and S. Nakai, Appl. Phys. Lett. 62, 1344 (1993)]. Multilayered depleted uranium (DU) and gold hohlraums are deposited by sputtering by alternately rotating a hohlraum mold in front of separate DU and Au sources to build up multilayers to the desired wall thickness. This mold is removed to leave a freestanding hohlraum half; two halves are used to assemble the complete NIF hohlraum to the design specifications. In practice, exposed DU oxidizes in air and other chemicals necessary to hohlraum production, so research has focused on developing a fabrication process that protects the U from damaging environments. This paper reports on the most current depleted uranium and gold cocktail hohlraum fabrication techniques, including characterization by Auger electron spectroscopy, which is used to verify sample composition and the amount of oxygen uptake over time.

  7. mTORC2 Signaling Regulates Nox4-Induced Podocyte Depletion in Diabetes

    PubMed Central

    Eid, Stéphanie; Boutary, Suzan; Braych, Kawthar; Sabra, Ramzi; Massaad, Charbel; Hamdy, Ahmed; Rashid, Awad; Moodad, Sarah; Block, Karen; Gorin, Yves; Abboud, Hanna E.

    2016-01-01

    Abstract Aim: Podocyte apoptosis is a critical mechanism for excessive loss of urinary albumin that eventuates in kidney fibrosis. Oxidative stress plays a critical role in hyperglycemia-induced glomerular injury. We explored the hypothesis that mammalian target of rapamycin complex 2 (mTORC2) mediates podocyte injury in diabetes. Results: High glucose (HG)-induced podocyte injury reflected by alterations in the slit diaphragm protein podocin and podocyte depletion/apoptosis. This was paralleled by activation of the Rictor/mTORC2/Akt pathway. HG also increased the levels of Nox4 and NADPH oxidase activity. Inhibition of mTORC2 using small interfering RNA (siRNA)-targeting Rictor in vitro decreased HG-induced Nox1 and Nox4, NADPH oxidase activity, restored podocin levels, and reduced podocyte depletion/apoptosis. Inhibition of mTORC2 had no effect on mammalian target of rapamycin complex 1 (mTORC1) activation, described by our group to be increased in diabetes, suggesting that the mTORC2 activation by HG could mediate podocyte injury independently of mTORC1. In isolated glomeruli of OVE26 mice, there was a similar activation of the Rictor/mTORC2/Akt signaling pathway with increase in Nox4 and NADPH oxidase activity. Inhibition of mTORC2 using antisense oligonucleotides targeting Rictor restored podocin levels, reduced podocyte depletion/apoptosis, and attenuated glomerular injury and albuminuria. Innovation: Our data provide evidence for a novel function of mTORC2 in NADPH oxidase-derived reactive oxygen species generation and podocyte apoptosis that contributes to urinary albumin excretion in type 1 diabetes. Conclusion: mTORC2 and/or NADPH oxidase inhibition may represent a therapeutic modality for diabetic kidney disease. Antioxid. Redox Signal. 25, 703–719. PMID:27393154

  8. Identification of Reprocessed Depleted Uranium in Contaminated Sediments From Cs-137 Activity Measurements

    NASA Astrophysics Data System (ADS)

    Arnason, J. G.; Bopp, R. F.

    2006-05-01

    Measurements of U series isotopes and fission products can be used to distinguish the relative contributions of natural and anthropogenic sources in U-contaminated sites. Anthropogenic sources include enriched uranium, depleted uranium (DU) byproduct from ore enrichment, and DU byproduct from spent fuel reprocessing. From 1958 to 1984 the National Lead industries plant in Colonie, New York, USA, emitted more than four metric tons of uranium as microscopic uranium oxide aerosols within a 1 km radius of the plant. Previous studies of a 3-m-long sediment core from Patroon Reservoir, located 1 km downstream of the plant, indicate that between 1.8 and 1.0 m depth, U concentrations are more than 100 times natural background and consist of 25 to 95 percent depleted uranium based on alpha spectroscopy. We measured 18 samples by gamma spectroscopy to better constrain the chronology of the core. Cesium-137 shows two activity peaks, one at approximately 2.0 m and another, broader peak between 1.5 and 1.0 m depth. The lower peak corresponds to the global fallout maximum of the mid 1960's and indicates a 5.5-6 cm/yr sedimentation rate that is consistent with the excess Pb-210 profile. In contrast, the upper Cs-137 peak corresponds to the interval containing DU, and suggests that there is a DU component derived from spent nuclear fuel. This hypothesis is consistent with a published report of U-236 detected in DU particles collected in air filters 15 km away at the Knolls Atomic Power Lab during the time of plant operation. It can be further tested through high resolution isotopic measurements of U-236 in the sediments themselves. Depleted uranium derived from spent fuel and containing U-236 will have higher total activity than DU derived from U ore and, as a result, could represent a greater hazard in the environment.

  9. OrigenArp Primer: How to Perform Isotopic Depletion and Decay Calculations with SCALE/ORIGEN

    SciTech Connect

    Bowman, Stephen M; Gauld, Ian C

    2010-08-01

    The SCALE (Standardized Computer Analyses for Licensing Evaluation) computer software system developed at Oak Ridge National Laboratory is widely used and accepted around the world for nuclear analyses. ORIGEN-ARP is a SCALE isotopic depletion and decay analysis sequence used to perform point-depletion calculations with the well-known ORIGEN-S code using problem-dependent cross sections. Problem-dependent cross-section libraries are generated using the ARP (Automatic Rapid Processing) module using an interpolation algorithm that operates on pre-generated libraries created for a range of fuel properties and operating conditions. Methods are provided in SCALE to generate these libraries using one-, two-, and three-dimensional transport codes. The interpolation of cross sections for uranium-based fuels may be performed for the variables burnup, enrichment, and water density. An option is also available to interpolate cross sections for mixed-oxide (MOX) fuels using the variables burnup, plutonium content, plutonium isotopic vector, and water moderator density. This primer is designed to help a new user understand and use ORIGEN-ARP with the OrigenArp Windows graphical user interface in SCALE. It assumes that the user has a college education in a technical field. There is no assumption of familiarity with nuclear depletion codes in general or with SCALE/ORIGEN-ARP in particular. The primer is based on SCALE 6 but should be applicable to earlier or later versions of SCALE. Information is included to help new users, along with several sample problems that walk the user through the different input forms and menus and illustrate the basic features. References to related documentation are provided. The primer provides a starting point for the nuclear analyst who uses SCALE/ORIGEN-ARP. Complete descriptions are provided in the SCALE documentation. Although the primer is self-contained, it is intended as a companion volume to the SCALE documentation. The SCALE Manual is

  10. New Insights into Fully-Depleted SOI Transistor Response During Total-Dose Irradiation

    SciTech Connect

    BURNS,J.A.; DODD,PAUL E.; KEAST,C.L.; SCHWANK,JAMES R.; SHANEYFELT,MARTY R.; WYATT,P.W.

    1999-09-14

    Previous work showed the possible existence of a total-dose latch effect in fully-depleted SOI transistors that could severely limit the radiation hardness of SOI devices. Other work showed that worst-case bias configuration during irradiation was the transmission gate bias configuration. In this work we further explore the effects of total-dose ionizing irradiation on fully-depleted SOI transistors. Closed-geometry and standard transistors fabricated in two fully-depleted processes were irradiated with 10-keV x rays. Our results show no evidence for a total-dose latch effect as proposed by others. Instead, in absence of parasitic trench sidewall leakage, our data suggests that the increase in radiation-induced leakage current is caused by positive charge trapping in the buried oxide inverting the back-channel interface. At moderate levels of trapped charge, the back-channel interface is slightly inverted causing a small leakage current to flow. This leakage current is amplified to considerably higher levels by impact ionization. Because the back-channel interface is in weak inversion, the top-gate bias can modulate the back-channel interface and turn the leakage current off at large, negative voltage levels. At high levels of trapped charge, the back-channel interface is fully inverted and the gate bias has little effect on leakage current. However, it is likely that this current also is amplified by impact ionization. For these transistors, the worst-case bias configuration was determined to be the ''ON'' bias configuration. These results have important implication on hardness assurance.

  11. Zinc-metallothionein genoprotective effect is independent of the glutathione depletion in HaCaT keratinocytes after solar light irradiation.

    PubMed

    Jourdan, Eric; Marie Jeanne, Richard; Régine, Steiman; Pascale, Guiraud

    2004-06-01

    UV radiations are the major environmental factors that induce DNA damage of skin cells either by direct absorption (UVB), or after inducing an oxidative stress (UVA and UVB). Cells maintain a reducing intracellular environment to avoid genomic damage. MTs have been expected not only to control metal homeostasis but also counteract the glutathione (GSH) depletion induced by oxidative stress because of their high thiol content. Induction and redistribution of MTs in cultured human keratinocytes (HaCaT) in response to SSL, is an important cellular defense mechanism against DNA damage. Reduced glutathione (GSH) is another way of cellular protection against UV-induced oxidative stress. This study which extend our previous finding focused on the relation between intracellular GSH and Zn genoprotective effects after solar irradiation. HaCaT cells, depleted or not in GSH by a chemical treatment were used to compare MTs induction by Northern blot, expression by Western blot and localization using immunocytochemistry. Zn genoprotection experiments after SSL irradiation was carried out by the comet assay. We demonstrated that in absence of GSH, Zn-MTs could protect DNA after SSL irradiation and that GSH depletion has no effect on MTs induction and localization. Nuclear Zn-MTs could be responsible for this observed genoprotection in GSH depleted cells. So the GSH/Zn and the MT/Zn systems could be two independent but interacting mechanisms of cellular protection against SSL injury.

  12. Elevated IFN-alpha/beta levels in a streptozotocin-induced type I diabetic mouse model promote oxidative stress and mediate depletion of spleen-homing CD8+ T cells by apoptosis through impaired CCL21/CCR7 axis and IL-7/CD127 signaling.

    PubMed

    Mahmoud, Mohamed H; Badr, Gamal; Badr, Badr Mohamed; Kassem, Ahmad Usama; Mohamed, Mahmoud Shaaban

    2015-10-01

    Type 1 diabetes mellitus (T1D) is associated with increased type 1 interferon (IFN) levels and subsequent severe defects in lymphocyte function, which increase susceptibility to infections. The blockade of type 1 IFN receptor 1 (IFNAR1) in non-obese diabetic mice has been shown to delay T1D onset and decrease T1D incidence by enhancing spleen CD4+ T cells and restoring B cell function. However, the effect of type 1 IFN blockade during T1D on splenic CD8+ T cells has not previously been studied. Therefore, we investigated, for the first time, the effect of IFNAR1 blockade on the survival and architecture of spleen-homing CD8+ T cells in a streptozotocin-induced T1D mouse model. Three groups of mice were examined: a non-diabetic control group; a diabetic group; and a diabetic group treated with an anti-IFNAR1 blocking antibody. We observed that T1D induction was accompanied by a marked destruction of β cells followed by a marked reduction in insulin levels and increased IFN-α and IFN-β levels in the diabetic group. The diabetic mice also exhibited many abnormal changes including an elevation in blood and spleen free radical (reactive oxygen species and nitric oxide) and pro-inflammatory cytokine (IL-6 and TNF-α) levels, a significant decrease in IL-7 levels, and subsequently, a significant decrease in the numbers of spleen-homing CD8+ T cells. This decrease in spleen-homing CD8+ T cells resulted from a marked reduction in the CCL21-mediated entry of CD8+ T cells into the spleen and from increased apoptosis due to a marked reduction in IL-7-mediated STAT5 and AKT phosphorylation. Interestingly, type 1 IFN signaling blockade in diabetic mice significantly restored the numbers of splenic CD8+ T cells by restoring free radical, pro-inflammatory cytokine and IL-7 levels. These effects subsequently rescued splenic CD8+ T cells from apoptosis through a mechanism that was dependent upon CCL21- and IL-7-mediated signaling. Our data suggest that type 1 IFN is an essential

  13. Packaging and Disposal of a Radium-beryllium Source using Depleted Uranium Polyethylene Composite Shielding

    SciTech Connect

    Keith Rule; Paul Kalb; Pete Kwaschyn

    2003-02-11

    Two, 111-GBq (3 Curie) radium-beryllium (RaBe) sources were in underground storage at the Brookhaven National Laboratory (BNL) since 1988. These sources originated from the Princeton Plasma Physics Laboratory (PPPL) where they were used to calibrate neutron detection diagnostics. In 1999, PPPL and BNL began a collaborative effort to expand the use of an innovative pilot-scale technology and bring it to full-scale deployment to shield these sources for eventual transport and burial at the Hanford Burial site. The transport/disposal container was constructed of depleted uranium oxide encapsulated in polyethylene to provide suitable shielding for both gamma and neutron radiation. This new material can be produced from recycled waste products (depleted uranium and polyethylene), is inexpensive, and can be disposed with the waste, unlike conventional lead containers, thus reducing exposure time for workers. This paper will provide calculations and information that led to the initial design of the shielding. We will also describe the production-scale processing of the container, cost, schedule, logistics, and many unforeseen challenges that eventually resulted in the successful fabrication and deployment of this shield. We will conclude with a description of the final configuration of the shielding container and shipping package along with recommendations for future shielding designs.

  14. Monitoring of singlet oxygen in the lower troposphere and processes of ozone depletion.

    NASA Astrophysics Data System (ADS)

    Iasenko, Egor; Chelibanov, Vladimir; Marugin, Alexander; Kozliner, Marat

    2016-04-01

    The processes of ozone depletion in the atmosphere are widely discussed now in a connection with the problem of a global climate changes. It is known fact that photolysis of ozone in the upper atmosphere is the source of metastable molecules of oxygen. But, metastable molecules of oxygen can be formed as a result of photo initiated heterogeneous oxidation of molecules adsorbed on the surface of natural aerosol particles. During the outdoor experiment, we observed a formation of Singlet oxygen (1Δg) at concentration level of 2 ... 5 ppb when ice crystals have been exposed to the sun light. In experiments, we used Analyzers of Singlet oxygen and Ozone (produced by JSC "OPTEC") that utilize solid-state chemiluminescence technology. We assumed that the singlet oxygen is formed in the active centers on the surface of ice crystals in the presence or absence of anthropogenic pollutants in the atmosphere. Identified efficiency of heterogeneous reaction of O2 (1Δg) formation suggests the importance of the additional channel O3 + O2 (1Δg) → 2O2 + O (3P) of atmospheric ozone removal comparable with other well known cycles of ozone depletion.

  15. Depletion-mediated red blood cell aggregation in polymer solutions.

    PubMed

    Neu, Björn; Meiselman, Herbert J

    2002-11-01

    Polymer-induced red blood cell (RBC) aggregation is of current basic science and clinical interest, and a depletion-mediated model for this phenomenon has been suggested; to date, however, analytical approaches to this model are lacking. An approach is thus described for calculating the interaction energy between RBC in polymer solutions. The model combines electrostatic repulsion due to RBC surface charge with osmotic attractive forces due to polymer depletion near the RBC surface. The effects of polymer concentration and polymer physicochemical properties on depletion layer thickness and on polymer penetration into the RBC glycocalyx are considered for 40 to 500 kDa dextran and for 18 to 35 kDa poly (ethylene glycol). The calculated results are in excellent agreement with literature data for cell-cell affinities and with RBC aggregation-polymer concentration relations. These findings thus lend strong support to depletion interactions as the basis for polymer-induced RBC aggregation and suggest the usefulness of this approach for exploring interactions between macromolecules and the RBC glycocalyx. PMID:12414682

  16. Adakites—the key to understanding LILE depletion in granulites

    NASA Astrophysics Data System (ADS)

    Rollinson, Hugh R.; Tarney, John

    2005-01-01

    For more than 20 years, it has been argued that granulites of the lower continental crust are depleted in fluid-mobile elements such as Cs, Rb, U and Th, either because they were removed by melting of the lower crust or through dehydration. We argue that there is little evidence for a simple relationship between granulite-facies metamorphism and element depletion, and propose that, for felsic orthogneisses, the depletion may be a primary feature of crust generation processes. Modern adakites show a range of fluid-mobile element ratios and adakites from the Austral Volcanic Zone (AVZ), Chile show fluid-mobile element ratios very similar to those found in lower crustal felsic granulites. This suite of adakites has a strong slab-derived component. We propose that modern adakites of the type found in the Austral Volcanic Zone are analogous, in their genesis, to lower crustal felsic granulites and that their mafic precursors were already depleted in fluid-mobile trace elements, prior to melting. An incremental melting model, in which fluid-mobile elements are released from an eclogitic slab prior to partial melting, can explain the fluid-mobile element behaviour of both modern adakites and lower crustal felsic granulites.

  17. Depletion of penicillin G residues in sows after intramuscular injection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A penicillin G procaine residue depletion study was conducted in heavy sows to estimate the pre-slaughter withdrawal periods necessary to clear penicillin from kidney and muscle. Heavy sows (n = 126) were treated with penicillin G procaine at a 5x dose (33,000 IU/kg) for 3 consecutive days by intra...

  18. Initial PVO Evidence of Electron Depletion Signatures Downstream of Venus

    NASA Technical Reports Server (NTRS)

    Intriligator, D. S.; Hartle, R. E.; Perez-de-Tejada, H.; Siscoe, G. L.

    1993-01-01

    This first analysis of Pioneer Venus Orbiter (PVO) plasma analyzer electron measurements obtained in early 1992 during the PVO entry phase of the mission indicates the presence downstream from the terminator of a depletion or "bite out" of energetic ionosheath electrons similar to that observed on Mariner 10. There is more than one possible explanation for this energetic electron depletion. If it is due to atmospheric scattering, the electrons traveling along draped magnetic flux tubes that thread through the Venus neutral atmosphere would lose energy from impact ionization with oxygen. The cross-section for such electron impact ionization of oxygen has a peak near 100 eV, and it remains high above this energy, so atmospheric loss could provide a natural process for electrons at these energies to be selectively removed. In this case, our results are consistent with the Kar et al. (1994) study of PVO atmospheric entry ion mass spectrometer data which indicates that electron impact plays a significant role in maintaining the nightside ionosphere. Although it is appealing to interpret the energetic electron depletion in terms of direct atmospheric scattering, alternatively it could result from strong draping which connects the depletion region magnetically to the weak downstream bow shock and thereby reduces the electron source strength.

  19. Initial PVO evidence of electron depletion signatures downstream of Venus

    NASA Technical Reports Server (NTRS)

    Intriligator, D. S.; Hartle, R. E.; Perez-De-tejada, H.; Siscoe, G. L.

    1993-01-01

    This first analysis of Pioneer Venus Orbiter (PVO) plasma analyzer electron measurements obtained in early 1992 during teh PVO entry phase of the mission indicates the presence downstream from the terminator of a depletion or 'bite out' of energetic ionosheath electrons similar to that observed on Mariner 10. There is more than one possible explanation for this energetic electron depletion. If it is due to atmospheric scattering, the electrons traveling along draped magnetic flux tubes that thread through the Venus neutral atmosphere would lose energy from impact ionization with oxygen. The cross-section for such electron impact ionization of oxygen has a peak near 100 eV, and it remains high above this energy, so atmospheric loss could provde a natural process for electrons at these energies to be selectively removed. In this case, our results are consistent with the Kar et al. (1994) study of PVO atmospheric entry ion mass spectrometer data, which indicates that electron impact plays a significant role in maintaining the nightside ionosphere. Although it is appealing to interpret the energetic electron depletion in terms of direct atmospheric scattering, alternatively it could result from strong draping which connects the depletion region magnetically to the weak downstream bow shock and thereby reduces the electron source strength.

  20. Stored mafic/ultramafic crust and early Archean mantle depletion

    NASA Technical Reports Server (NTRS)

    Chase, Clement G.; Patchett, P. J.

    1990-01-01

    Both early and late Archean rocks from greenstone belts and felsic gneiss complexes exhibit positive epsilon(Nd) values of +1 to +5 by 3.5 Ga, demonstrating that a depleted mantle reservoir existed very early. The amount of preserved pre-3.0 Ga continental crust cannot explain such high epsilon values in the depleted residue unless the volume of residual mantle was very small: a layer less than 70 km thick by 3.0 Ga. Repeated and exclusive sampling of such a thin layer, especially in forming the felsic gneiss complexes, is implausible. Extraction of enough continental crust to deplete the early mantle and its destructive recycling before 3.0 Ga ago requires another implausibility, that the sites of crustal generation of recycling were substantially distinct. In contrast, formation of mafic or ultramafic crust analogous to present-day oceanic crust was continuous from very early times. Recycled subducted oceanic lithosphere is a likely contributor to present-day hotspot magmas, and forms a reservoir at least comparable in volume to continental crust. Subduction of an early mafic/ultramafic oceanic crust and temporary storage rather than immediate mixing back into undifferentiated mantle may be responsible for the depletion and high epsilon(Nd) values of the Archean upper mantle.

  1. 48 CFR 52.223-11 - Ozone-Depleting Substances.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... substance the Environmental Protection Agency designates in 40 CFR part 82 as— (1) Class I, including, but... required by 42 U.S.C. 7671j (b), (c), and (d) and 40 CFR part 82, subpart E, as follows: “WARNING: Contains... 48 Federal Acquisition Regulations System 2 2011-10-01 2011-10-01 false Ozone-Depleting...

  2. 48 CFR 52.223-11 - Ozone-Depleting Substances.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... substance the Environmental Protection Agency designates in 40 CFR part 82 as— (1) Class I, including, but... required by 42 U.S.C. 7671j (b), (c), and (d) and 40 CFR part 82, subpart E, as follows: “WARNING: Contains... 48 Federal Acquisition Regulations System 2 2012-10-01 2012-10-01 false Ozone-Depleting...

  3. 48 CFR 52.223-11 - Ozone-Depleting Substances.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... substance the Environmental Protection Agency designates in 40 CFR part 82 as— (1) Class I, including, but... required by 42 U.S.C. 7671j (b), (c), and (d) and 40 CFR part 82, subpart E, as follows: “WARNING: Contains... 48 Federal Acquisition Regulations System 2 2013-10-01 2013-10-01 false Ozone-Depleting...

  4. 48 CFR 52.223-11 - Ozone-Depleting Substances.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... substance the Environmental Protection Agency designates in 40 CFR part 82 as— (1) Class I, including, but... required by 42 U.S.C. 7671j (b), (c), and (d) and 40 CFR part 82, subpart E, as follows: “WARNING: Contains... 48 Federal Acquisition Regulations System 2 2014-10-01 2014-10-01 false Ozone-Depleting...

  5. 48 CFR 52.223-11 - Ozone-Depleting Substances.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... substance the Environmental Protection Agency designates in 40 CFR part 82 as— (1) Class I, including, but... required by 42 U.S.C. 7671j (b), (c), and (d) and 40 CFR part 82, subpart E, as follows: “WARNING: Contains... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Ozone-Depleting...

  6. Depleted uranium dioxide powder flow through very small openings

    SciTech Connect

    Sutter, S.L.; Johnston, J.W.; Owzarski, P.C.; Mishima, J.; Schwendiman, L.C.

    1981-01-01

    Release of plutonium dioxide from a breached shipping container was simulated using depleted uranium dioxide. Microgram quantities of the powder were carried by pressurized air through very small openings in a vessel approximately the same dimensions as a shipping container. Powder transmission was measured as a function of upstream pressure above and below the static powder level. 3 refs.

  7. Abrupt Depletion Layer Approximation for the Metal Insulator Semiconductor Diode.

    ERIC Educational Resources Information Center

    Jones, Kenneth

    1979-01-01

    Determines the excess surface change carrier density, surface potential, and relative capacitance of a metal insulator semiconductor diode as a function of the gate voltage, using the precise questions and the equations derived with the abrupt depletion layer approximation. (Author/GA)

  8. 11. VIEW OF DEPLETED URANIUM INGOT. THE METALS WERE PLACED ...

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

    11. VIEW OF DEPLETED URANIUM INGOT. THE METALS WERE PLACED IN CRUCIBLES, LOADED INTO ONE OF EIGHT INDUCTION FURNACES AND MELTED IN A VACUUM ATMOSPHERE. (11/11/57) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO

  9. 9. VIEW OF FOUNDRY FURNACE, DEPLETED URANIUM INGOTS, BERYLLIUM INGOTS, ...

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

    9. VIEW OF FOUNDRY FURNACE, DEPLETED URANIUM INGOTS, BERYLLIUM INGOTS, AND ALUMINUM SHAPES WERE PRODUCED IN THE FOUNDRY. (10/30/56) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO

  10. Theory of colloid depletion stabilization by unattached and adsorbed polymers.

    PubMed

    Semenov, A N; Shvets, A A

    2015-12-01

    The polymer-induced forces between colloidal particles in a semidilute or concentrated polymer solution are considered theoretically. This study is focussed on the case of partially adsorbing colloidal surfaces involving some attractive centers able to trap polymer segments. In the presence of free polymers the particles are covered by self-assembled fluffy layers whose structure is elucidated. It is shown that the free-polymer-induced interaction between the particles is repulsive at distances exceeding the polymer correlation length, and that this depletion repulsion can be strongly enhanced due to the presence of fluffy layers. This enhanced depletion stabilization mechanism (which works in tandem with a more short-range steric repulsion of fluffy layers) can serve on its own to stabilize colloidal dispersions. More generally, we identify three main polymer-induced interaction mechanisms: depletion repulsion, depletion attraction, and steric repulsion. Their competition is analyzed both numerically and analytically based on an asymptotically rigorous mean-field theory. It is shown that colloid stabilization can be achieved by simply increasing the molecular weight of polymer additives, or by changing their concentration.

  11. Computation of rate and volume of stream depletion by wells

    USGS Publications Warehouse

    Jenkins, C.T.

    1968-01-01

    When field conditions approach certain assumed conditions, the depletion in flow of a nearby stream caused by pumping a well can be calculated readily by using dimensionless curves and tables. Computations can be made of (1) the rate of stream depletion at any time during the pumping period or the following nonpumping period, (2) the volume of water induced from the stream during any period, pumping or non-pumping, and (3) the effects, both in rate and volume of stream depletion, of any selected pattern of intermittent pumping. Sample computations illustrate the use of the curves and tables. An example shows that intermittent pumping may have a pattern of stream depletion not greatly different from a pattern for steady pumping of an equal volume. The residual effects of pumping, that is, effects after pumping stops, on streamflow may often be greater than the effects during the pumping period. Adequate advance planning that includes consideration of residual effects thus is essential to effective management of a stream-aquifer system.

  12. Spearfishing to depletion: evidence from temperate reef fishes in Chile.

    PubMed

    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. PMID:20945755

  13. Fully depleted back-illuminated p-channel CCD development

    SciTech Connect

    Bebek, Chris J.; Bercovitz, John H.; Groom, Donald E.; Holland, Stephen E.; Kadel, Richard W.; Karcher, Armin; Kolbe, William F.; Oluseyi, Hakeem M.; Palaio, Nicholas P.; Prasad, Val; Turko, Bojan T.; Wang, Guobin

    2003-07-08

    An overview of CCD development efforts at Lawrence Berkeley National Laboratory is presented. Operation of fully-depleted, back-illuminated CCD's fabricated on high resistivity silicon is described, along with results on the use of such CCD's at ground-based observatories. Radiation damage and point-spread function measurements are described, as well as discussion of CCD fabrication technologies.

  14. Spearfishing to depletion: evidence from temperate reef fishes in Chile.

    PubMed

    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.

  15. Depletion analysis of the UMLRR reactor core using MCNP6

    NASA Astrophysics Data System (ADS)

    Odera, Dim Udochukwu

    Accurate knowledge of the neutron flux and temporal nuclide inventory in reactor physics calculations is necessary for a variety of application in nuclear engineering such as criticality safety, safeguards, and spent fuel storage. The Monte Carlo N- Particle (MCNP6) code with integrated buildup depletion code (CINDER90) provides a high-fidelity tool that can be used to perform 3D, full core simulation to evaluate fissile material utilization, and nuclide inventory calculations as a function of burnup. The University of Massachusetts Lowell Research Reactor (UMLRR) reactor has been modeled with the deterministic based code, VENTURE and with an older version of MCNP (MCNP5). The MIT developed MCODE (MCNP ORIGEN DEPLETION CODE) was used previously to perform some limited depletion calculations. This work chronicles the use of MCNP6, released in June 2013, to perform coupled neutronics and depletion calculation. The results are compared to previously benchmarked results. Furthermore, the code is used to determine the ratio of fission products 134Cs and 137Cs (burnup indicators), and the resultant ratio is compared to the burnup of the UMLRR.

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

    SciTech Connect

    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.

  17. The effect of complement depletion on lung clearance of bacteria.

    PubMed

    Gross, G N; Rehm, S R; Pierce, A K

    1978-08-01

    We have investigated the effect of hypocomplementemia on early pulmonary clearance of four species of bacteria. The experiments were performed in an inbred animal model to minimize immunologic variability. Complement was depleted by cobra venom factor, and activity in serum was monitored with a phagocytic assay. Bacterial specific antibodies were examined by an indirect radioimmunoassay, and animals with high levels of activity were excluded from anaysis. 4 h after aerosolization with Streptococcus pneumoniae, complement-depleted animals had cleared only 75% of the initial number of organisms, whereas saline-treated controls cleared 91% (P less than 0.01). Aerosolization with Pseudomonas aeruginosa was followed at 4 h by a twofold greater growth of organisms in the complement-depleted animals (446% of original deposition) as compared to the saline-treated controls (211% of original deposition) (P less than 0.02). Clearance of Klebsiella pneumoniae and Staphylococcus aureus were similar in complement-depleted animals and saline-treated controls. These experiments suggest that hypocomplementemia predisposes to bacterial pneumonia and may explain the high incidence of pulmonary infections in patients having impaired complement activity. Our results further indicate that varying defense mechanisms may be involved with clearing the lung of differing bacterial species. PMID:27534

  18. A method to estimate groundwater depletion from confining layers

    USGS Publications Warehouse

    Konikow, L.F.; Neuzil, C.E.

    2007-01-01

    Although depletion of storage in low-permeability confining layers is the source of much of the groundwater produced from many confined aquifer systems, it is all too frequently overlooked or ignored. This makes effective management of groundwater resources difficult by masking how much water has been derived from storage and, in some cases, the total amount of water that has been extracted from an aquifer system. Analyzing confining layer storage is viewed as troublesome because of the additional computational burden and because the hydraulic properties of confining layers are poorly known. In this paper we propose a simplified method for computing estimates of confining layer depletion, as well as procedures for approximating confining layer hydraulic conductivity (K) and specific storage (Ss) using geologic information. The latter makes the technique useful in developing countries and other settings where minimal data are available or when scoping calculations are needed. As such, our approach may be helpful for estimating the global transfer of groundwater to surface water. A test of the method on a synthetic system suggests that the computational errors will generally be small. Larger errors will probably result from inaccuracy in confining layer property estimates, but these may be no greater than errors in more sophisticated analyses. The technique is demonstrated by application to two aquifer systems: the Dakota artesian aquifer system in South Dakota and the coastal plain aquifer system in Virginia. In both cases, depletion from confining layers was substantially larger than depletion from the aquifers.

  19. The Mutual Intertemporal Benefits from Depletable Resource Use.

    ERIC Educational Resources Information Center

    Wiseman, Clark

    2002-01-01

    Offers graphical proof of the proposition that the dynamically efficient allocation of a depletable, nonrenewable resource allows higher net benefits to users in both time periods than any other allocation. States that in this proof the result is more general and does not require the numerical specification of other previous models. (JEH)

  20. Seasonal oxygen depletion in the North Sea, a review.

    PubMed

    Topcu, H D; Brockmann, U H

    2015-10-15

    Seasonal mean oxygen depletion in offshore and coastal North Sea bottom waters was shown to range between 0.9 and 1.8 mg/L, corresponding to 95-83% saturation, between July and October over a 30-year assessment period (1980-2010). The magnitude of oxygen depletion was controlled by thermal stratification, modulated by water depth and nitrogen availability. Analyses were based on about 19,000 combined data sets. Eutrophication problem areas were identified mainly in coastal waters by oxygen minima, the lower 10th percentile of oxygen concentrations, and deviations of oxygen depletion from correlated stratification values. Connections between oxygen consumption and nitrogen sources and conversion, including denitrification, were indicated by correlations. Mean oxygen consumption reflected a minimum seasonal turnover of 3.1 g N/m(2) in the south-eastern North Sea, including denitrification of 1 g N/m(2). Oxygen depletion was underestimated in shallow coastal waters due to repeated erosion of stratification as indicated by local high variability.

  1. Identifying water mass depletion in northern Iraq observed by GRACE

    NASA Astrophysics Data System (ADS)

    Mulder, G.; Olsthoorn, T. N.; Al-Manmi, D. A. M. A.; Schrama, E. J. O.; Smidt, E. H.

    2015-03-01

    Observations acquired by Gravity Recovery And Climate Experiment (GRACE) mission indicate a mass loss of 146 ± 6 mm equivalent water height (EWH) in northern Iraq between 2007 and 2009. These data are used as an independent validation of lake mass variations and a rainfall-runoff model, which is based on local geology and climate conditions. Model inputs are precipitation from Tropical Rainfall Measurement Mission (TRMM) observations, and climatic parameters from Global Land Data Assimilation Systems (GLDAS) model parameters. The model is calibrated with observed river discharge and includes a representation of the karstified aquifers in the region to improve model realism. Lake mass variations were 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 captures the annual cycle and longer trend of the observed GRACE data. The total mass depletion seen by GRACE between 2007 and 2009 is mainly explained by a lake mass depletion of 75 ± 3 mm EWH and a natural groundwater depletion of 39 ± 8 mm EWH. Our findings indicate that anthropogenic groundwater extraction has a minor influence in this region, while a decline in lake mass and natural depletion of groundwater play a key role.

  2. Depleting methyl bromide residues in soil by reaction with bases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite generally being considered the most effective soil fumigant, methyl bromide (MeBr) use is being phased out because its emissions from soil can lead to stratospheric ozone depletion. However, a large amount is still currently used due to Critical Use Exemptions. As strategies for reducing the...

  3. Development of depletion perturbation theory for a reactor nodal code

    SciTech Connect

    Bowman, S.M.

    1981-09-01

    A generalized depletion perturbation (DPT) theory formulation for light water reactor (LWR) depletion problems is developed and implemented into the three-dimensional LWR nodal code SIMULATE. This development applies the principles of the original derivation by M.L. Williams to the nodal equations solved by SIMULATE. The present formulation is first described in detail, and the nodal coupling methodology in SIMULATE is used to determine partial derivatives of the coupling coefficients. The modifications to the original code and the new DPT options available to the user are discussed. Finally, the accuracy and the applicability of the new DPT capability to LWR design analysis are examined for several LWR depletion test cases. The cases range from simple static cases to a realistic PWR model for an entire fuel cycle. Responses of interest included K/sub eff/, nodal peaking, and peak nodal exposure. The nonlinear behavior of responses with respect to perturbations of the various types of cross sections was also investigated. The time-dependence of the sensitivity coefficients for different responses was examined and compared. Comparison of DPT results for these examples to direct calculations reveals the limited applicability of depletion perturbation theory to LWR design calculations at the present. The reasons for these restrictions are discussed, and several methods which might improve the computational accuracy of DPT are proposed for future research.

  4. GLOBAL CHANGE RESEARCH NEWS #7: ENVIRONMENTAL EFFECTS OF OZONE DEPLETION

    EPA Science Inventory

    This edition focuses on a recent UNEP report entitled, "Environmental Effects of Ozone Depletion: 1998 Assessment." Dr. Richard Zepp (ORD/NERL) is one of the Lead Authors of this report. The 1998 assessment focuses on new information produced since 1994. It also includes earlie...

  5. Radiation-enhanced gate-induced-drain-leakage current in the 130 nm partially-depleted SOI pMOSFET

    NASA Astrophysics Data System (ADS)

    Peng, Chao; Hu, Zhiyuan; Ning, Bingxu; Dai, Lihua; Bi, Dawei; Zhang, Zhengxuan

    2015-04-01

    The total ionizing dose (TID) effect of the pMOSFET from 130 nm partially-depleted silicon-on-insulator (PDSOI) is investigated. The data obtained from 60Co γ-ray irradiation experiments indicate that input/output (I/O) device is more susceptible to TID effect than the core device. An anomalous off-state leakage increase is observed for I/O pMOSFET when drain is biased at a high voltage after irradiation. It is proved that this radiation-induced leakage relates to the enhanced gate-induce-drain-leakage (GIDL). Both the radiation-induced interface traps at the gate-oxide/body interface and the oxide trapped charges in the buried oxide (BOX) are responsible for the growth of the leakage current. These conclusions are also verified by the TCAD simulations. The isothermal annealing can recover the leakage current to the pre-irradiation level.

  6. Ozone depletion, related UVB changes and increased skin cancer incidence

    NASA Astrophysics Data System (ADS)

    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. Enhanced Monte-Carlo-Linked Depletion Capabilities in MCNPX

    SciTech Connect

    Fensin, Michael L.; Hendricks, John S.; Anghaie, Samim

    2006-07-01

    As advanced reactor concepts challenge the accuracy of current modeling technologies, a higher-fidelity depletion calculation is necessary to model time-dependent core reactivity properly for accurate cycle length and safety margin determinations. The recent integration of CINDER90 into the MCNPX Monte Carlo radiation transport code provides a completely self-contained Monte-Carlo-linked depletion capability. Two advances have been made in the latest MCNPX capability based on problems observed in pre-released versions: continuous energy collision density tracking and proper fission yield selection. Pre-released versions of the MCNPX depletion code calculated the reaction rates for (n,2n), (n,3n), (n,p), (n,a), and (n,?) by matching the MCNPX steady-state 63-group flux with 63-group cross sections inherent in the CINDER90 library and then collapsing to one-group collision densities for the depletion calculation. This procedure led to inaccuracies due to the miscalculation of the reaction rates resulting from the collapsed multi-group approach. The current version of MCNPX eliminates this problem by using collapsed one-group collision densities generated from continuous energy reaction rates determined during the MCNPX steady-state calculation. MCNPX also now explicitly determines the proper fission yield to be used by the CINDER90 code for the depletion calculation. The CINDER90 code offers a thermal, fast, and high-energy fission yield for each fissile isotope contained in the CINDER90 data file. MCNPX determines which fission yield to use for a specified problem by calculating the integral fission rate for the defined energy boundaries (thermal, fast, and high energy), determining which energy range contains the majority of fissions, and then selecting the appropriate fission yield for the energy range containing the majority of fissions. The MCNPX depletion capability enables complete, relatively easy-to-use depletion calculations in a single Monte Carlo code

  8. Therapeutic depletion of natural killer cells controls persistent infection.

    PubMed

    Waggoner, Stephen N; Daniels, Keith A; Welsh, Raymond M

    2014-02-01

    Persistent viral infections are associated with host and viral factors that impair effective antiviral immunity. Natural killer (NK) cells contribute to establishment of persistent lymphocytic choriomeningitis virus (LCMV) infection in mice through suppression of virus-specific T cell responses during the first few days of infection, but NK cell depletion during those early time points can enable severe T cell-mediated immune pathology and death of the host. Here we show that long after their peak in cytolytic activation, NK cells continue to support viral persistence at later times of infection. Delayed depletion of NK cells, 2 to 3 weeks after infection, enhanced virus-specific T cell responses and viral control. This enhancing effect of delayed NK cell depletion on antiviral immunity, in contrast to early NK cell depletion, was not associated with increased morbidity and mortality, and mice quickly regained weight after treatment. The efficacy of the depletion depended in part upon the size of the original virus inoculum, the viral load at the time of depletion, and the presence of CD4 T cells. Each of these factors is an important contributor to the degree of CD8 T cell dysfunction during viral persistence. Thus, NK cells may continuously contribute to exhaustion of virus-specific T cells during chronic infection, possibly by depleting CD4 T cells. Targeting of NK cells could thus be considered in combination with blockade of other immunosuppressive pathways, such as the interleukin-10 (IL-10) and programmed death 1 (PD-1) pathways, as a therapy to cure chronic human infections, including those with HIV or hepatitis C virus. IMPORTANCE Persistent virus infections are a major threat to global human health. The capacity of viruses, including HIV and hepatitis C virus, to overwhelm or subvert host immune responses contributes to a prolonged state of dampened antiviral immune functionality, which in turn facilitates viral persistence. Recent efforts have focused on

  9. Endoplasmic reticulum thiol oxidase deficiency leads to ascorbic acid depletion and noncanonical scurvy in mice.

    PubMed

    Zito, Ester; Hansen, Henning Gram; Yeo, Giles S H; Fujii, Junichi; Ron, David

    2012-10-12

    Endoplasmic reticulum (ER) thiol oxidases initiate a disulfide relay to oxidatively fold secreted proteins. We found that combined loss-of-function mutations in genes encoding the ER thiol oxidases ERO1α, ERO1β, and PRDX4 compromised the extracellular matrix in mice and interfered with the intracellular maturation of procollagen. These severe abnormalities were associated with an unexpectedly modest delay in disulfide bond formation in secreted proteins but a profound, 5-fold lower procollagen 4-hydroxyproline content and enhanced cysteinyl sulfenic acid modification of ER proteins. Tissue ascorbic acid content was lower in mutant mice, and ascorbic acid supplementation improved procollagen maturation and lowered sulfenic acid content in vivo. In vitro, the presence of a sulfenic acid donor accelerated the oxidative inactivation of ascorbate by an H(2)O(2)-generating system. Compromised ER disulfide relay thus exposes protein thiols to competing oxidation to sulfenic acid, resulting in depletion of ascorbic acid, impaired procollagen proline 4-hydroxylation, and a noncanonical form of scurvy.

  10. Calcium depletion in a Southeastern United States forest ecosystem

    USGS Publications Warehouse

    Huntington, T.G.; Hooper, R.P.; Johnson, C.E.; Aulenbach, Brent T.; Cappellato, R.; Blum, A.E.

    2000-01-01

    Forest soil Ca depletion through leaching and vegetation uptake may threaten long-term sustainability of forest productivity in the southeastern USA. This study was conducted to assess Ca pools and fluxes in a representative southern Piedmont forest to determine the soil Ca depletion rate. Soil Ca storage, Ca inputs in atmospheric deposition, and outputs in soil leaching and vegetation uptake were investigated at the Panola Mountain Research Watershed (PMRW) near Atlanta, GA. Average annual outputs of 12.3 kg ha-1 yr-1 in uptake into merchantable wood and 2.71 kg ha-1 yr-1 soil leaching exceeded inputs in atmospheric deposition of 2.24 kg ha-1 yr-1. The annual rate of Ca uptake into merchantable wood exceeds soil leaching losses by a factor of more than five. The potential for primary mineral weathering to provide a substantial amount of Ca inputs is low. Estimates of Ca replenishment through mineral weathering in the surface 1 m of soil and saprolite was estimated to be 0.12 kg ha-1 yr-1. The weathering rate in saprolite and partially weathered bedrock below the surface 1 m is similarly quite low because mineral Ca is largely depleted. The soil Ca depletion rate at PMRW is estimated to be 12.7 kg ha-1 yr-1. At PMRW and similar hardwood-dominated forests in the Piedmont physiographic province, Ca depletion will probably reduce soil reserves to less than the requirement for a merchantable forest stand in ???80 yr. This assessment and comparable analyses at other southeastern USA forest sites suggests that there is a strong potential for a regional problem in forest nutrition in the long term.Forest soil Ca depletion through leaching and vegetation uptake may threaten long-term sustainability of forest productivity in the southeastern USA. This study was conducted to assess Ca pools and fluxes in a representative southern Piedmont forest to determine the soil Ca depletion rate. Soil Ca storage, Ca inputs in atmospheric deposition, and outputs in soil leaching and

  11. Milk fat composition of Holstein and Jersey cows with control or depleted copper status and fed whole soybeans or tallow.

    PubMed

    Sol Morales, M; Palmquist, D L; Weiss, W P

    2000-09-01

    We studied effects of breed, dietary fat source, and dietary copper intake as factors known to influence unsaturation of milk fat and its potential for development of spontaneous oxidized flavor in milk. Twelve Holstein and 12 Jersey cows were allotted to three blocks with four cows of each breed. Cows within breed were allotted randomly within blocks and fed control or copper-depleting diets for 2 mo to achieve stable or depleted liver copper stores. Cows then were fed tallow or roasted whole soybeans in a two-period switchback (5 wk per period); during the last week of each period additional vitamin E (2000 IU/d) was added. Copper depletion for 2 mo decreased concentrations of copper in liver. Feed intake and milk yield were influenced only by breed. The proportions of C4:0 to C14:0 and C18:0 in milk fat were higher, whereas C16:1 and cis-C18:1 were lower in Jersey cows. Feeding soybeans increased C4:0 to C14:0, C18:0, C18:2, and C18:3 in milk, and decreased C14:1, C16:0, C16:1, trans-C18:1, and cis-C18:1. Depleted copper status increased conjugated linoleic acid in milk. Several breed x fat source interactions for individual milk fatty acids occurred. Feeding soybeans decreased plasma concentrations of copper and zinc, and increased concentrations of alpha-tocopherol in plasma and milk. The concentration of zinc was higher in milk of Jersey cows. Depleted copper status tended to increase copper concentration in plasma and decreased copper in milk. Fat source did not influence plasma copper concentration when status was adequate, but plasma copper concentration was higher when tallow was fed to cows with depleted copper status. Supplementing vitamin E increased concentration of alpha-tocopherol in plasma and milk and decreased concentration of zinc in milk. Factors influencing the potential for oxidized flavor development in milk can be manipulated by changing the diet of the cow.

  12. Cholesterol depletion increases membrane stiffness of aortic endothelial cells.

    PubMed

    Byfield, Fitzroy J; Aranda-Espinoza, Helim; Romanenko, Victor G; Rothblat, George H; Levitan, Irena

    2004-11-01

    This study has investigated the effect of cellular cholesterol on membrane deformability of bovine aortic endothelial cells. Cellular cholesterol content was depleted by exposing the cells to methyl-beta-cyclodextrin or enriched by exposing the cells to methyl-beta-cyclodextrin saturated with cholesterol. Control cells were treated with methyl-beta-cyclodextrin-cholesterol at a molar ratio that had no effect on the level of cellular cholesterol. Mechanical properties of the cells with different cholesterol contents were compared by measuring the degree of membrane deformation in response to a step in negative pressure applied to the membrane by a micropipette. The experiments were performed on substrate-attached cells that maintained normal morphology. The data were analyzed using a standard linear elastic half-space model to calculate Young elastic modulus. Our observations show that, in contrast to the known effect of cholesterol on membrane stiffness of lipid bilayers, cholesterol depletion of bovine aortic endothelial cells resulted in a significant decrease in membrane deformability and a corresponding increase in the value of the elastic coefficient of the membrane, indicating that cholesterol-depleted cells are stiffer than control cells. Repleting the cells with cholesterol reversed the effect. An increase in cellular cholesterol to a level higher than that of normal cells, however, had no effect on the elastic properties of bovine aortic endothelial cells. We also show that although cholesterol depletion had no apparent effect on the intensity of F-actin-specific fluorescence, disrupting F-actin with latrunculin A abrogated the stiffening effect. We suggest that cholesterol depletion increases the stiffness of the membrane by altering the properties of the submembrane F-actin and/or its attachment to the membrane.

  13. Fundamental differences between Arctic and Antarctic ozone depletion.

    PubMed

    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. PMID:24733920

  14. Fundamental differences between Arctic and Antarctic ozone depletion

    PubMed Central

    Solomon, Susan; Haskins, Jessica; Ivy, Diane J.; Min, Flora

    2014-01-01

    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. PMID:24733920

  15. Fundamental differences between Arctic and Antarctic ozone depletion.

    PubMed

    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.

  16. Oceanic bromoform emissions weighted by their ozone depletion potential

    NASA Astrophysics Data System (ADS)

    Tegtmeier, S.; Ziska, F.; Pisso, I.; Quack, B.; Velders, G. J. M.; Yang, X.; Krüger, K.

    2015-12-01

    At present, anthropogenic halogens and oceanic emissions of very short-lived substances (VSLSs) both contribute to the observed stratospheric ozone depletion. Emissions of the long-lived anthropogenic halogens have been reduced and are currently declining, whereas emissions of the biogenic VSLSs are expected to increase in future climate due to anthropogenic activities affecting oceanic production and emissions. Here, we introduce a new approach for assessing the impact of oceanic halocarbons on stratospheric ozone by calculating their ozone depletion potential (ODP)-weighted emissions. Seasonally and spatially dependent, global distributions are derived within a case-study framework for CHBr3 for the period 1999-2006. At present, ODP-weighted emissions of CHBr3 amount up to 50 % of ODP-weighted anthropogenic emissions of CFC-11 and to 9 % of all long-lived ozone depleting halogens. The ODP-weighted emissions are large where strong oceanic emissions coincide with high-reaching convective activity and show pronounced peaks at the Equator and the coasts with largest contributions from the Maritime Continent and western Pacific Ocean. Variations of tropical convective activity lead to seasonal shifts in the spatial distribution of the trajectory-derived ODP with the updraught mass flux, used as a proxy for trajectory-derived ODP, explaining 71 % of the variance of the ODP distribution. Future climate projections based on the RCP 8.5 scenario suggest a 31 % increase of the ODP-weighted CHBr3 emissions by 2100 compared to present values. This increase is related to a larger convective updraught mass flux in the upper troposphere and increasing emissions in a future climate. However, at the same time, it is reduced by less effective bromine-related ozone depletion due to declining stratospheric chlorine concentrations. The comparison of the ODP-weighted emissions of short- and long-lived halocarbons provides a new concept for assessing the overall impact of oceanic

  17. Iron(II) Initiation of Lipid and Protein Oxidation in Pork: The Role of Oxymyoglobin.

    PubMed

    Zhou, Feibai; Jongberg, Sisse; Zhao, Mouming; Sun, Weizheng; Skibsted, Leif H

    2016-06-01

    Iron(II), added as FeSO4·7H2O, was found to increase the rate of oxygen depletion as detected electrochemically in a pork homogenate from Longissimus dorsi through an initial increase in metmyoglobin formation from oxymyoglobin and followed by formation of primary and secondary lipid oxidation products and protein oxidation as detected as thiol depletion in myofibrillar proteins. Without added iron(II), under the same conditions at 37 °C, oxygen consumption corresponded solely to the slow oxymyoglobin autoxidation. Long-lived myofibrillar protein radicals as detected by ESR spectroscopy in the presence of iron(II) were formed subsequently to oxymyoglobin oxidation, and their level was increased by lipid oxidation when oxygen was completely depleted. Similarly, the time profile for formation of lipid peroxide indicated that oxymyoglobin oxidation initiates both protein oxidation and lipid oxidation.

  18. LINE-1 hypomethylation induced by reactive oxygen species is mediated via depletion of S-adenosylmethionine.

    PubMed

    Kloypan, Chiraphat; Srisa-art, Monpicha; Mutirangura, Apiwat; Boonla, Chanchai

    2015-08-01

    Whether long interspersed nuclear element-1 (LINE-1) hypomethylation induced by reactive oxygen species (ROS) was mediated through the depletion of S-adenosylmethionine (SAM) was investigated. Bladder cancer (UM-UC-3 and TCCSUP) and human kidney (HK-2) cell lines were exposed to 20 μM H2O2 for 72 h to induce oxidative stress. Level of LINE-1 methylation, SAM and homocysteine (Hcy) was measured in the H2O2 -exposed cells. Effects of α-tocopheryl acetate (TA), N-acetylcysteine (NAC), methionine, SAM and folic acid on oxidative stress and LINE-1 methylation in the H2O2 -treated cells were explored. Viabilities of cells treated with H2O2 were not significantly changed. Intracellular ROS production and protein carbonyl content were significantly increased, but LINE-1 methylation was significantly decreased in the H2O2 -treated cells. LINE-1 methylation was restored by TA, NAC, methionine, SAM and folic acid. SAM level in H2O2 -treated cells was significantly decreased, while total glutathione was significantly increased. SAM level in H2O2 -treated cells was restored by NAC, methionine, SAM and folic acid; while, total glutathione level was normalized by TA and NAC. Hcy was significantly decreased in the H2O2 -treated cells and subsequently restored by NAC. In conclusion, in bladder cancer and normal kidney cells exposed to H2O2 , SAM and Hcy were decreased, but total glutathione was increased. Treatments with antioxidants (TA and NAC) and one-carbon metabolites (SAM, methionine and folic acid) restored these changes. This pioneer finding suggests that exposure of cells to ROS activates glutathione synthesis via the transsulfuration pathway leading to deficiency of Hcy, which consequently causes SAM depletion and eventual hypomethylation of LINE-1.

  19. Selective depletion of vascular EC-SOD augments chronic hypoxic pulmonary hypertension.

    PubMed

    Nozik-Grayck, Eva; Woods, Crystal; Taylor, Joann M; Benninger, Richard K P; Johnson, Richard D; Villegas, Leah R; Stenmark, Kurt R; Harrison, David G; Majka, Susan M; Irwin, David; Farrow, Kathryn N

    2014-12-01

    Excess superoxide has been implicated in pulmonary hypertension (PH). We previously found lung overexpression of the antioxidant extracellular superoxide dismutase (EC-SOD) attenuates PH and pulmonary artery (PA) remodeling. Although comprising a small fraction of total SOD activity in most tissues, EC-SOD is abundant in arteries. We hypothesize that the selective loss of vascular EC-SOD promotes hypoxia-induced PH through redox-sensitive signaling pathways. EC-SOD(loxp/loxp) × Tg(cre/SMMHC) mice (SMC EC-SOD KO) received tamoxifen to conditionally deplete smooth muscle cell (SMC)-derived EC-SOD. Mice were exposed to hypobaric hypoxia for 35 days, and PH was assessed by right ventricular systolic pressure measurements and right ventricle hypertrophy. Vascular remodeling was evaluated by morphometric analysis and two-photon microscopy for collagen. We examined cGMP content and soluble guanylate cyclase expression and activity in lung, lung phosphodiesterase 5 (PDE5) expression and activity, and expression of endothelial nitric oxide synthase and GTP cyclohydrolase-1 (GTPCH-1), the rate-limiting enzyme in tetrahydrobiopterin synthesis. Knockout of SMC EC-SOD selectively decreased PA EC-SOD without altering total lung EC-SOD. PH and vascular remodeling induced by chronic hypoxia was augmented in SMC EC-SOD KO. Depletion of SMC EC-SOD did not impact content or activity of lung soluble guanylate cyclase or PDE5, yet it blunted the hypoxia-induced increase in cGMP. Although total eNOS was not altered, active eNOS and GTPCH-1 decreased with hypoxia only in SMC EC-SOD KO. We conclude that the localized loss of PA EC-SOD augments chronic hypoxic PH. In addition to oxidative inactivation of NO, deletion of EC-SOD seems to reduce eNOS activity, further compromising pulmonary vascular function. PMID:25326578

  20. Deferoxamine prevents cerebral glutathione and vitamin E depletions in asphyxiated neonatal rats: role of body temperature.

    PubMed

    Kletkiewicz, Hanna; Nowakowska, Anna; Siejka, Agnieszka; Mila-Kierzenkowska, Celestyna; Woźniak, Alina; Caputa, Michał; Rogalska, Justyna

    2016-01-01

    Hypoxic-ischaemic brain injury involves increased oxidative stress. In asphyxiated newborns iron deposited in the brain catalyses formation of reactive oxygen species. Glutathione (GSH) and vitamin E are key factors protecting cells against such agents. Our previous investigation has demonstrated that newborn rats, showing physiological low body temperature as well as their hyperthermic counterparts injected with deferoxamine (DF) are protected against iron-mediated, delayed neurotoxicity of perinatal asphyxia. Therefore, we decided to study the effects of body temperature and DF on the antioxidant status of the brain in rats exposed neonatally to critical anoxia. Two-day-old newborn rats were exposed to anoxia in 100% nitrogen atmosphere for 10 min. Rectal temperature was kept at 33 °C (physiological to rat neonates), or elevated to the level typical of healthy adult rats (37 °C), or of febrile adult rats (39 °C). Half of the rats exposed to anoxia under extremely hyperthermic conditions (39 °C) were injected with DF. Cerebral concentrations of malondialdehyde (MDA, lipid peroxidation marker) and the levels of GSH and vitamin E were determined post-mortem, (1) immediately after anoxia, (2) 3 days, (3) 7 days, and (4) 2 weeks after anoxia. There were no post-anoxic changes in MDA, GSH and vitamin E concentrations in newborn rats kept at body temperature of 33 °C. In contrast, perinatal anoxia at elevated body temperatures intensified oxidative stress and depleted the antioxidant pool in a temperature-dependent manner. Both the depletion of antioxidants and lipid peroxidation were prevented by post-anoxic DF injection. The data support the idea that hyperthermia may extend perinatal anoxia-induced brain lesions.

  1. Deferoxamine prevents cerebral glutathione and vitamin E depletions in asphyxiated neonatal rats: role of body temperature.

    PubMed

    Kletkiewicz, Hanna; Nowakowska, Anna; Siejka, Agnieszka; Mila-Kierzenkowska, Celestyna; Woźniak, Alina; Caputa, Michał; Rogalska, Justyna

    2016-01-01

    Hypoxic-ischaemic brain injury involves increased oxidative stress. In asphyxiated newborns iron deposited in the brain catalyses formation of reactive oxygen species. Glutathione (GSH) and vitamin E are key factors protecting cells against such agents. Our previous investigation has demonstrated that newborn rats, showing physiological low body temperature as well as their hyperthermic counterparts injected with deferoxamine (DF) are protected against iron-mediated, delayed neurotoxicity of perinatal asphyxia. Therefore, we decided to study the effects of body temperature and DF on the antioxidant status of the brain in rats exposed neonatally to critical anoxia. Two-day-old newborn rats were exposed to anoxia in 100% nitrogen atmosphere for 10 min. Rectal temperature was kept at 33 °C (physiological to rat neonates), or elevated to the level typical of healthy adult rats (37 °C), or of febrile adult rats (39 °C). Half of the rats exposed to anoxia under extremely hyperthermic conditions (39 °C) were injected with DF. Cerebral concentrations of malondialdehyde (MDA, lipid peroxidation marker) and the levels of GSH and vitamin E were determined post-mortem, (1) immediately after anoxia, (2) 3 days, (3) 7 days, and (4) 2 weeks after anoxia. There were no post-anoxic changes in MDA, GSH and vitamin E concentrations in newborn rats kept at body temperature of 33 °C. In contrast, perinatal anoxia at elevated body temperatures intensified oxidative stress and depleted the antioxidant pool in a temperature-dependent manner. Both the depletion of antioxidants and lipid peroxidation were prevented by post-anoxic DF injection. The data support the idea that hyperthermia may extend perinatal anoxia-induced brain lesions. PMID:26794834

  2. Inhibition of Ammonia Oxidation in Nitrosomonas europaea by Sulfur Compounds: Thioethers Are Oxidized to Sulfoxides by Ammonia Monooxygenase

    PubMed Central

    Juliette, Lisa Y.; Hyman, Michael R.; Arp, Daniel J.

    1993-01-01

    Organic sulfur compounds are well-known nitrification inhibitors. The inhibitory effects of dimethylsulfide, dimethyldisulfide, and ethanethiol on ammonia oxidation by Nitrosomonas europaea were examined. Both dimethylsulfide and dimethyldisulfide were weak inhibitors of ammonia oxidation and exhibited inhibitory characteristics typical of substrates for ammonia monooxygenase (AMO). Depletion of dimethylsulfide required O2 and was prevented with either acetylene or allylthiourea, two inhibitors of AMO. The inhibition of ammonia oxidation by dimethylsulfide was examined in detail. Cell suspensions incubated in the presence of ammonia oxidized dimethylsulfide to dimethyl sulfoxide. Depletion of six other thioethers was also prevented by treating cell suspensions with either allylthiourea or acetylene. The oxidative products of three thioethers were identified as the corresponding sulfoxides. The amount of sulfoxide formed accounted for a majority of the amount of sulfide depleted. By using gas chromatography coupled with mass spectrometry, allylmethylsulfide was shown to be oxidized to allylmethylsulfoxide by N. europaea with the incorporation of a single atom of 18O derived from 18O2 into the sulfide. This result supported our conclusion that a monooxygenase was involved in the oxidation of allylmethylsulfide. The thioethers are concluded to be a new class of substrates for AMO. This is the first report of the oxidation of the sulfur atom by AMO in whole cells of N. europaea. The ability of N. europaea to oxidize dimethylsulfide is not unique among the ammonia-oxidizing bacteria. Nitrosococcus oceanus, a marine nitrifier, was also demonstrated to oxidize dimethylsulfide to dimethyl sulfoxide. PMID:16349086

  3. Stepwise Depletion of Coating Elements as a Result of Hot Corrosion of NiCrAlY Coatings

    NASA Astrophysics Data System (ADS)

    Rana, Nidhi; Jayaganthan, R.; Prakash, Satya

    2013-11-01

    Present investigation deals with the hot corrosion behaviour of the NiCrAlY coatings deposited by HVOF technique on Superni76 under cyclic conditions at 900 °C in the presence of Na2SO4 + 60% V2O5 salt. The weight change behaviour of the coatings was followed with time up to 200 cycles and K p value was calculated for the hot corrosion process. Surface and cross-section of the corroded samples were examined by FESEM/EDS and XRD to follow the progress of corrosion up to 200 cycles. In earlier cycles, the corrosive species oxidised top surface of the coatings. With increasing number of cycles, oxidation of the coatings occurred up to 40-μm depth. A Cr-depleted band was seen below the oxide scale. Further increase in number of cycles led to migration and oxidation of Al to form Al2O3 sublayer at coating/scale interface, thereby leading to formation of Al-depleted zone in the coating below the Al2O3 sublayer. The corrosion resistance of the NiCrAlY coatings is attributed to the formation of the continuous and dense Al2O3 sublayer at the coating/scale interface, which acts as barrier to the migration of Cr to the surface. The appearance of Al3Y after 100 and 200 cycles also contributes to the increased corrosion resistance of coatings after 100 and 200 cycles.

  4. CRDIAC: Coupled Reactor Depletion Instrument with Automated Control

    SciTech Connect

    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 depletion

  5. Evaluating groundwater depletion as computed by a global water model

    NASA Astrophysics Data System (ADS)

    Schuh, Carina; Doell, Petra; Mueller Schmied, Hannes; Portmann, Felix

    2013-04-01

    When groundwater abstraction occurs faster than its replenishment over a long time and in a large area, the result is an overexploitation or depletion of groundwater. The problem is aggravated in areas where a growing population relies on freshwater resources for an intensive irrigation agriculture that is meant to guarantee food security. Especially in semi-arid and arid regions, the dominant use for groundwater is irrigation, reaching more than 95% of total water use. Therefore, the hot spots for groundwater depletion are the world's major irrigation areas like the central United States, north-western India and north China. Groundwater depletion presents a major threat to securing agricultural productivity and domestic water supply in these parts of the world. Besides, the environmental consequences that accompany the abstraction of groundwater are severe. Within the scientific community there is a common understanding that high-quality data on globally existing groundwater resources are deficient. In order to allow a sustainable management of the world's available groundwater resources, especially in areas under current water stress, the quantification of groundwater depletion is of high importance. WaterGAP (Water - Global Assessment and Prognosis) is a global model of water availability and water use which can serve to estimate the impact of groundwater and surface water withdrawals on groundwater storage. The new WaterGAP version 2.2a was modified to allow for an improved analysis of groundwater storage changes in semi-arid and arid regions. Now, groundwater recharge from surface water bodies is simulated in semi-arid and arid areas. Estimation of net groundwater abstractions was modified with respect of irrigation water use efficiency for groundwater and return flow fractions. In addition, irrigation consumptive use has been set to 70% of optimal irrigation consumptive use, assuming deficit irrigation to prevail in these parts of the world. Based on time

  6. Magmatic Degassing and the Volatile Depletion of the Moon

    NASA Astrophysics Data System (ADS)

    Rutherford, M. J.; Saal, A. E.; Hauri, E.

    2015-12-01

    The detection of highly volatile elements in lunar volcanic glasses and melt inclusions has provided the first definitive evidence for the accretion and retention of these elements in the Moon's interior1,2. Measurement of H in lunar apatite, at levels similar to terrestrial apatite, has added weight to this discovery3,4. These results are at odds with the longest-standing observations that the abundances of highly- and moderately-volatile elements in lunar basalts are as much as 1000 times more depleted than in terrestrial basalts5. We will show that most of these apparent contradictions have arisen due to the previously unappreciated importance of a single widespread process, magmatic degassing. Degassing occurs in all eruptions of magma, with the consequent release of volatile elements into an exsolved vapor phase. We use ours and previously published results to evaluate lunar magmatic degassing and to show that A) volatile element contents for the bulk silicate Moon (BSM) are only moderately depleted compared with the bulk silicate Earth (range 0.5-0.1, avg. 0.25 x BSE), B) they essentially overlap the composition of the terrestrial depleted MORB source and C) the volatile depletion pattern for the BSM is largely flat, and so does not correlate with condensation temperature at 10-4 bars, nor with bond energy for likely ligands. Published high-precision Sr and Pb isotope ratios on well-dated lunar rocks6-8 reveal 87Rb/86Sr and 238U/204Pb ratios of the lunar mantle a factor of 0.3-0.5 and 0.28-0.85 depleted compared to those of the BSE, respectively; lending support to our estimates for the abundances of Rb (0.245 x BSE) and Pb (0.187 x BSE) in the BSM. Before the Moon's extent of volatile depletion can be confidently attributed to the accretion processes, magmatic degassing must be examined and critically evaluated. References [1] Saal et al., 2008. Nature 454, 192. [2] Hauri et al., 2015. FEPS 409, 252. [3] Boyce et al., 2014. Sc. 344, 400. [4] Anand et al

  7. Changes in tropospheric composition and air quality due to stratospheric ozone depletion and climate change.

    PubMed

    Wilson, S R; Solomon, K R; Tang, X

    2007-03-01

    It is well-understood that reductions in air quality play a significant role in both environmental and human health. Interactions between ozone depletion and global climate change will significantly alter atmospheric chemistry which, in turn, will cause changes in concentrations of natural and human-made gases and aerosols. Models predict that tropospheric ozone near the surface will increase globally by up to 10 to 30 ppbv (33 to 100% increase) during the period 2000 to 2100. With the increase in the amount of the stratospheric ozone, increased transport from the stratosphere to the troposphere will result in different responses in polluted and unpolluted areas. In contrast, global changes in tropospheric hydroxyl radical (OH) are not predicted to be large, except where influenced by the presence of oxidizable organic matter, such as from large-scale forest fires. Recent measurements in a relatively clean location over 5 years showed that OH concentrations can be predicted by the intensity of solar ultraviolet radiation. If this relationship is confirmed by further observations, this approach could be used to simplify assessments of air quality. Analysis of surface-level ozone observations in Antarctica suggests that there has been a significant change in the chemistry of the boundary layer of the atmosphere in this region as a result of stratospheric ozone depletion. The oxidation potential of the Antarctic boundary layer is estimated to be greater now than before the development of the ozone hole. Recent modeling studies have suggested that iodine and iodine-containing substances from natural sources, such as the ocean, may increase stratospheric ozone depletion significantly in polar regions during spring. Given the uncertainty of the fate of iodine in the stratosphere, the results may also be relevant for stratospheric ozone depletion and measurements of the influence of these substances on ozone depletion should be considered in the future. In agreement with

  8. Changes in tropospheric composition and air quality due to stratospheric ozone depletion and climate change.

    PubMed

    Wilson, S R; Solomon, K R; Tang, X

    2007-03-01

    It is well-understood that reductions in air quality play a significant role in both environmental and human health. Interactions between ozone depletion and global climate change will significantly alter atmospheric chemistry which, in turn, will cause changes in concentrations of natural and human-made gases and aerosols. Models predict that tropospheric ozone near the surface will increase globally by up to 10 to 30 ppbv (33 to 100% increase) during the period 2000 to 2100. With the increase in the amount of the stratospheric ozone, increased transport from the stratosphere to the troposphere will result in different responses in polluted and unpolluted areas. In contrast, global changes in tropospheric hydroxyl radical (OH) are not predicted to be large, except where influenced by the presence of oxidizable organic matter, such as from large-scale forest fires. Recent measurements in a relatively clean location over 5 years showed that OH concentrations can be predicted by the intensity of solar ultraviolet radiation. If this relationship is confirmed by further observations, this approach could be used to simplify assessments of air quality. Analysis of surface-level ozone observations in Antarctica suggests that there has been a significant change in the chemistry of the boundary layer of the atmosphere in this region as a result of stratospheric ozone depletion. The oxidation potential of the Antarctic boundary layer is estimated to be greater now than before the development of the ozone hole. Recent modeling studies have suggested that iodine and iodine-containing substances from natural sources, such as the ocean, may increase stratospheric ozone depletion significantly in polar regions during spring. Given the uncertainty of the fate of iodine in the stratosphere, the results may also be relevant for stratospheric ozone depletion and measurements of the influence of these substances on ozone depletion should be considered in the future. In agreement with

  9. Optical AND/OR gates based on monolithically integrated vertical cavity laser with depleted optical thyristor structure.

    PubMed

    Choi, Woon-Kyung; Kim, Doo-Gun; Kim, Do-Gyun; Choi, Young-Wan; Choquette, Kent D; Lee, Seok; Woo, Deok-Ha

    2006-11-27

    Latching optical switches and optical logic gates with AND and OR functionality are demonstrated for the first time by the monolithic integration of a vertical cavity lasers with depleted optical thyristor structure. The thyristors have a low threshold current of 0.65 mA and a high on/off contrast ratio of more than 50 dB. By simply changing a reference switching voltage, this single device operates as two logic functions, optical logic AND and OR. The thyristor laser fabricated by using the oxidation process and has achieved high optical output power efficiency and a high sensitivity to the optical input light.

  10. The sensitivity of polar ozone depletion to proposed geoengineering schemes.

    PubMed

    Tilmes, Simone; Müller, Rolf; Salawitch, Ross

    2008-05-30

    The large burden of sulfate aerosols injected into the stratosphere by the eruption of Mount Pinatubo in 1991 cooled Earth and enhanced the destruction of polar ozone in the subsequent few years. The continuous injection of sulfur into the stratosphere has been suggested as a "geoengineering" scheme to counteract global warming. We use an empirical relationship between ozone depletion and chlorine activation to estimate how this approach might influence polar ozone. An injection of sulfur large enough to compensate for surface warming caused by the doubling of atmospheric CO2 would strongly increase the extent of Arctic ozone depletion during the present century for cold winters and would cause a considerable delay, between 30 and 70 years, in the expected recovery of the Antarctic ozone hole.

  11. Shock induced multi-mode damage in depleted uranium

    SciTech Connect

    Koller, Darcie D; Cerreta, Ellen K; Gray, Ill, George T

    2009-01-01

    Recent dynamic damage studies on depleted uranium samples have revealed mixed mode failure mechanisms leading to incipient cracking as well as ductile failure processes. Results show that delamination of inclusions upon compression may provide nucleation sites for damage initiation in the form of crack tip production. However, under tension the material propagates cracks in a mixed shear localization and mode-I ductile tearing and cracking. Cracks tips appear to link up through regions of severe, shear dominated plastic flow. Shock recovery experiments were conducted on a 50 mm single stage light gas gun. Serial metallographic sectioning was conducted on the recovered samples to characterize the bulk response of the sample. Experiments show delaminated inclusions due to uniaxial compression without damage propagation. Further results show the propagation of the damage through tensile loading to the incipient state, illustrating ductile processes coupled with mixed mode-I tensile ductile tearing, shear localization, and mode-I cracking in depleted uranium.

  12. Currents through Hv1 channels deplete protons in their vicinity

    PubMed Central

    De-la-Rosa, Víctor; Suárez-Delgado, Esteban; Rangel-Yescas, Gisela E.

    2016-01-01

    Proton channels have evolved to provide a pH regulatory mechanism, affording the extrusion of protons from the cytoplasm at all membrane potentials. Previous evidence has suggested that channel-mediated acid extrusion could significantly change the local concentration of protons in the vicinity of the channel. In this work, we directly measure the proton depletion caused by activation of Hv1 proton channels using patch-clamp fluorometry recordings from channels labeled with the Venus fluorescent protein at intracellular domains. The fluorescence of the Venus protein is very sensitive to pH, thus behaving as a genetically encoded sensor of local pH. Eliciting outward proton currents increases the fluorescence intensity of Venus. This dequenching is related to the magnitude of the current and not to channel gating and is dependent on the pH gradient. Our results provide direct evidence of local proton depletion caused by flux through the proton-selective channel. PMID:26809792

  13. Nuclear structure and depletion of nuclear isomers using electron linacs

    SciTech Connect

    Carroll, J. J.; Litz, M. S.; Henriquez, S. L.; Burns, D. A.; Netherton, K. A.; Pereira, N. R.; Karamian, S. A.

    2013-04-19

    Long-lived nuclear excited states (isomers) have proven important to understanding nuclear structure. With some isomers having half-lives of decades or longer, and intrinsic energy densities reaching 10{sup 12} J/kg, they have also been suggested for a wide range of applications. The ability to effectively transfer a population of nuclei from an isomer to shorter-lived levels will determine the feasibility of any applications. Here is described a first demonstration of the induced depletion of a population of the 438 year isomer of {sup 108}Ag to its 2.38 min ground state, using 6 MeV bremsstrahlung from a modified medical electron linac. The experiment suggests refinements to be implemented in the future and how a similar approach might be applied to study induced depletion of the 1200 year isomer of {sup 166}Ho.

  14. Mass depletion: A new parameter for quantitative jet modification

    NASA Astrophysics Data System (ADS)

    Majumder, A.; Putschke, J.

    2016-05-01

    We propose an extension to classify jet modification in heavy-ion collisions by including the jet mass along with its energy. The mass of a jet, as measured by jet reconstruction algorithms, is constrained by the jet's virtuality, which in turn has a considerable effect on such observables as the fragmentation function and jet shape observables. The leading parton, propagating through a dense medium, experiences substantial virtuality (or mass) depletion along with energy loss. Meaningful comparisons between surviving jets and jets produced in p -p collisions require mass depletion to be taken into account. Using a vacuum event generator, we show the close relationship between the actual jet mass and that after applying a jet reconstruction algorithm. Using an in-medium event generator, we demonstrate the clear difference between the mass of a surviving parton exiting a dense medium and a parton with a similar energy formed in a hard scattering event. Effects of this difference on jet observables are discussed.

  15. Copper-triazole interaction and coolant inhibitor depletion

    SciTech Connect

    Bartley, L.S.; Fritz, P.O.; Pellet, R.J.; Taylor, S.A.; Van de Ven, P.

    1999-08-01

    To a large extent, the depletion of tolyltriazole (TTZ) observed in several field tests may be attributed to the formation of a protective copper-triazole layer. Laboratory aging studies, shown to correlate with field experience, reveal that copper-TTZ layer formation depletes coolant TTZ levels in a fashion analogous to changes observed in the field. XPS and TPD-MS characterization of the complex formed indicates a strong chemical bond between copper and the adsorbed TTZ which can be desorbed thermally only at elevated temperatures. Electrochemical polarization experiments indicate that the layer provides good copper protection even when TTZ is absent from the coolant phase. Examination of copper cooling system components obtained after extensive field use reveals the presence of a similar protective layer.

  16. Currents through Hv1 channels deplete protons in their vicinity.

    PubMed

    De-la-Rosa, Víctor; Suárez-Delgado, Esteban; Rangel-Yescas, Gisela E; Islas, León D

    2016-02-01

    Proton channels have evolved to provide a pH regulatory mechanism, affording the extrusion of protons from the cytoplasm at all membrane potentials. Previous evidence has suggested that channel-mediated acid extrusion could significantly change the local concentration of protons in the vicinity of the channel. In this work, we directly measure the proton depletion caused by activation of Hv1 proton channels using patch-clamp fluorometry recordings from channels labeled with the Venus fluorescent protein at intracellular domains. The fluorescence of the Venus protein is very sensitive to pH, thus behaving as a genetically encoded sensor of local pH. Eliciting outward proton currents increases the fluorescence intensity of Venus. This dequenching is related to the magnitude of the current and not to channel gating and is dependent on the pH gradient. Our results provide direct evidence of local proton depletion caused by flux through the proton-selective channel.

  17. Impact of polar ozone depletion on subtropical precipitation.

    PubMed

    Kang, S M; Polvani, L M; Fyfe, J C; Sigmond, M

    2011-05-20

    Over the past half-century, the ozone hole has caused a poleward shift of the extratropical westerly jet in the Southern Hemisphere. Here, we argue that these extratropical circulation changes, resulting from ozone depletion, have substantially contributed to subtropical precipitation changes. Specifically, we show that precipitation in the southern subtropics in austral summer increases significantly when climate models are integrated with reduced polar ozone concentrations. Furthermore, the observed patterns of subtropical precipitation change, from 1979 to 2000, are very similar to those in our model integrations, where ozone depletion alone is prescribed. In both climate models and observations, the subtropical moistening is linked to a poleward shift of the extratropical westerly jet. Our results highlight the importance of polar regions for the subtropical hydrological cycle. PMID:21512001

  18. The sensitivity of polar ozone depletion to proposed geoengineering schemes.

    PubMed

    Tilmes, Simone; Müller, Rolf; Salawitch, Ross

    2008-05-30

    The large burden of sulfate aerosols injected into the stratosphere by the eruption of Mount Pinatubo in 1991 cooled Earth and enhanced the destruction of polar ozone in the subsequent few years. The continuous injection of sulfur into the stratosphere has been suggested as a "geoengineering" scheme to counteract global warming. We use an empirical relationship between ozone depletion and chlorine activation to estimate how this approach might influence polar ozone. An injection of sulfur large enough to compensate for surface warming caused by the doubling of atmospheric CO2 would strongly increase the extent of Arctic ozone depletion during the present century for cold winters and would cause a considerable delay, between 30 and 70 years, in the expected recovery of the Antarctic ozone hole. PMID:18436741

  19. Anthropogenic and climate-driven water depletion in Asia

    NASA Astrophysics Data System (ADS)

    Yi, Shuang; Sun, Wenke; Feng, Wei; Chen, Jianli

    2016-09-01

    Anthropogenic depletion of terrestrial water storage (TWS) can be alleviated in wet years and intensified in dry years, and this wet/dry pattern spanning seasons to years is termed climate variability. However, the anthropogenic and climate-driven changes have not been isolated in previous studies; thus, the estimated trend of changes in TWS is strongly dependent on the study period. Here we try to remove the influence of climate variability from the estimation of the anthropogenic contribution, which is an indicator of the environmental burden and important for TWS projections. Toward this end, we propose a linear relationship between the variation in water storage and precipitation. Factors related to the sensitivity of water storage to precipitation are given to correct for the climate variability, and the anthropogenic depletion of terrestrial water and groundwater in Asia is estimated to be -187 ± 38 Gt/yr and -100 ± 47 Gt/yr, respectively.

  20. Effect of temperature coupling on ozone depletion prediction

    NASA Technical Reports Server (NTRS)

    Chandra, S.; Butler, D. M.; Stolarski, R. S.

    1978-01-01

    The effects of chlorine perturbations on both the temperature and the ozone distribution in the stratosphere have been studied using a simplified radiative-photochemical model. The model solves the hydrostatic equation for total density in a self-consistent manner as the temperature is changed. Radiative coupling is found to have a significant effect on both the thermal structure and the ozone distribution, particularly in the 35-50-km region. By increasing the ClX mixing ratio by 5.0 ppbv, the temperature in this region is decreased by 5 to 10 K with a slight increase below 30 km. The local ozone depletion around 40 km due to added ClX is smaller compared with the estimate made by keeping the temperature fixed to the ambient condition. However, the integrated effect of radiative coupling is to increase the calculated column ozone depletion by 15% to 25% in this model.

  1. Visualization of stratospheric ozone depletion and the polar vortex

    NASA Technical Reports Server (NTRS)

    Treinish, Lloyd A.

    1995-01-01

    Direct analysis of spacecraft observations of stratospheric ozone yields information about the morphology of annual austral depletion. Visual correlation of ozone with other atmospheric data illustrates the diurnal dynamics of the polar vortex and contributions from the upper troposphere, including the formation and breakup of the depletion region each spring. These data require care in their presentation to minimize the introduction of visualization artifacts that are erroneously interpreted as data features. Non geographically registered data of differing mesh structures can be visually correlated via cartographic warping of base geometries without interpolation. Because this approach is independent of the realization technique, it provides a framework for experimenting with many visualization strategies. This methodology preserves the fidelity of the original data sets in a coordinate system suitable for three-dimensional, dynamic examination of atmospheric phenomena.

  2. Neutrophil depletion delays wound repair in aged mice

    PubMed Central

    Nishio, Naomi; Okawa, Yayoi; Sakurai, Hidetoshi

    2008-01-01

    One of the most important clinical problems in caring for elderly patients is treatment of pressure ulcers. One component of normal wound healing is the generation of an inflammatory reaction, which is characterized by the sequential infiltration of neutrophils, macrophages and lymphocytes. Neutrophils migrate early in the wound healing process. In aged C57BL/6 mice, wound healing is relatively inefficient. We examined the effects of neutrophil numbers on wound healing in both young and aged mice. We found that the depletion of neutrophils by anti-Gr-1 antibody dramatically delayed wound healing in aged mice. The depletion of neutrophils in young mice had less effect on the kinetics of wound healing. Intravenous G-CSF injection increased the migration of neutrophils to the wound site. While the rate of wound repair did not change significantly in young mice following G-CSF injection, it increased significantly in old mice. PMID:19424869

  3. Depletion interactions effected by different variants of fd virus.

    PubMed

    July, Christoph; Lang, Peter R

    2010-12-21

    The depletion interaction between a probe sphere and a flat wall induced by fd virus is investigated by means of total internal reflection microscopy (TIRM). The viruses serve as a model system for monodisperse, rod-like colloids. We find that the experimental potentials are well described by the first-order density approximation up to an fd content of several overlap concentrations. This is in accordance with higher order density theory as confirmed by numerical calculations. Since the first-order analytical description still holds for all measurements, this exemplifies that higher order terms of the theory are unimportant for our system. Comparing the potentials induced by wild-type fd to those induced by a more rigid fd variant, it can be shown that the influence of the virus stiffness is beyond our experimental resolution and plays only a negligible role for the measured depletion potentials.

  4. Glutathione depletion by valproic acid in sandwich-cultured rat hepatocytes: Role of biotransformation and temporal relationship with onset of toxicity

    SciTech Connect

    Kiang, Tony K.L.; Teng Xiaowei; Surendradoss, Jayakumar; Karagiozov, Stoyan; Abbott, Frank S.; Chang, Thomas K.H.

    2011-05-01

    The present study was conducted in sandwich-cultured rat hepatocytes to investigate the chemical basis of glutathione (GSH) depletion by valproic acid (VPA) and evaluate the role of GSH depletion in VPA toxicity. Among the synthetic metabolites of VPA investigated, 4-ene-VPA and (E)-2,4-diene-VPA decreased cellular levels of total GSH, but only (E)-2,4-diene-VPA was more effective and more potent than the parent drug. The in situ generated, cytochrome P450-dependent 4-ene-VPA did not contribute to GSH depletion by VPA, as suggested by the experiment with a cytochrome P450 inhibitor, 1-aminobenzotriazole, to decrease the formation of this metabolite. In support of a role for metabolites, alpha-F-VPA and octanoic acid, which do not undergo biotransformation to form a 2,4-diene metabolite, CoA ester, or glucuronide, did not deplete GSH. A time course experiment showed that GSH depletion did not occur prior to the increase in 2',7'-dichlorofluorescein (a marker of oxidative stress), the decrease in [2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium] (WST-1) product formation (a marker of cell viability), or the increase in lactate dehydrogenase (LDH) release (a marker of necrosis) in VPA-treated hepatocytes. In conclusion, the cytochrome P450-mediated 4-ene-VPA pathway does not play a role in the in situ depletion of GSH by VPA, and GSH depletion is not an initiating event in VPA toxicity in sandwich-cultured rat hepatocytes.

  5. Feedback Response to Selective Depletion of Endogenous Carbon Monoxide in the Blood.

    PubMed

    Kitagishi, Hiroaki; Minegishi, Saika; Yumura, Aki; Negi, Shigeru; Taketani, Shigeru; Amagase, Yoko; Mizukawa, Yumiko; Urushidani, Tetsuro; Sugiura, Yukio; Kano, Koji

    2016-04-27

    The physiological roles of endogenous carbon monoxide (CO) have not been fully understood because of the difficulty in preparing a loss-of-function phenotype of this molecule. Here, we have utilized in vivo CO receptors, hemoCDs, which are the supramolecular 1:1 inclusion complexes of meso-tetrakis(4-sulfonatophenyl)porphinatoiron(II) with per-O-methylated β-cyclodextrin dimers. Three types of hemoCDs (hemoCD1, hemoCD2, and hemoCD3) that exhibit different CO-affinities have been tested as CO-depleting agents in vivo. Intraperitoneally administered hemoCD bound endogenous CO within the murine circulation, and was excreted in the urine along with CO in an affinity-dependent manner. The sufficient administration of hemoCD that has higher CO-affinity than hemoglobin (Hb) produced a pseudoknockdown state of CO in the mouse in which heme oxygenase-1 (HO-1) was markedly induced in the liver, causing the acceleration of endogenous CO production to maintain constant CO-Hb levels in the blood. The contents of free hemin and bilirubin in the blood plasma of the treated mice significantly increased upon removal of endogenous CO by hemoCD. Thus, a homeostatic feedback model for the CO/HO-1 system was proposed as follows: HemoCD primarily removes CO from cell-free CO-Hb. The resulting oxy-Hb is quickly oxidized to met-Hb by oxidant(s) such as hydrogen peroxide in the blood plasma. The met-Hb readily releases free hemin that directly induces HO-1 in the liver, which metabolizes the hemin into iron, biliverdin, and CO. The newly produced CO binds to ferrous Hb to form CO-Hb as an oxidation-resistant state. Overall, the present system revealed the regulatory role of CO for maintaining the ferrous/ferric balance of Hb in the blood.

  6. Gamma-ray line intensities for depleted uranium

    SciTech Connect

    Moss, C.E.

    1985-01-01

    Measurements of the gamma-ray line intensities from depleted uranium allowed us to determine which of two conflicting previous experiments was correct. For the 1001-keV line we obtain a branching ratio of 0.834 +- 0.007, in good agreement with one of the previous experiments. A table compares our intensities for several lines with those obtained in previous experiments. 5 refs., 2 figs., 1 tab.

  7. Depleted uranium: properties, military use and health risks.

    PubMed

    Fairlie, Ian

    2009-01-01

    This article describes uranium and depleted uranium (DU), their similar isotopic compositions, how DU arises, its use in munitions and armour-proofing, and its pathways for human exposures. Particular attention is paid to the evidence of DU's health effects from cell and animal experiments and from epidemiology studies. It is concluded that a precautionary approach should be adopted to DU and that there should be a moratorium on its use by military forces. International efforts to this end are described.

  8. Depletion-induced structure and dynamics in bimodal colloidal suspensions.

    SciTech Connect

    Sikorski, M.; Sandy, A. R.; Narayanan, S.

    2011-05-03

    Combined small angle x-ray scattering and x-ray photon correlation spectroscopy studies of moderately concentrated bimodal hard-sphere colloidal suspensions in the fluid phase show that depletion-induced demixing introduces spatially heterogeneous dynamics with two distinct time scales. The adhesive nature, as well as the mobility, of the large particles is determined by the level of interaction within the monomodal domains. This interaction is driven by osmotic forces, which are governed by the relative concentration of the constituents.

  9. Stimulated emission depletion microscopy to study amyloid fibril formation

    NASA Astrophysics Data System (ADS)

    Mahou, Pierre; Curry, Nathan; Pinotsi, Dorothea; Kaminski Schierle, Gabriele; Kaminski, Clemens

    2015-03-01

    Aggregation of misfolded proteins is a characteristic hallmark of many neurodegenerative disorders, such as Parkinson's, Alzheimer's and Huntington's diseases. The ability to observe these aggregation processes and the corresponding structures formed in vitro or in situ is therefore a key requirement to understand the molecular mechanisms of these diseases. We report here on the implementation and application of Stimulated Emission Depletion (STED) microscopy to visualize the formation of amyloid fibrils in vitro.

  10. Macrophage depletion ameliorates nephritis induced by pathogenic antibodies

    PubMed Central

    Chalmers, Samantha A.; Chitu, Violeta; Herlitz, Leal C.; Sahu, Ranjit; Stanley, E. Richard; Putterman, Chaim

    2014-01-01

    Objective Kidney involvement affects 40–60% of patients with lupus and is responsible for significant morbidity and mortality. Using depletion approaches, several studies have suggested that macrophages may play a key role in the pathogenesis of lupus nephritis. However, “off target” effects of macrophage depletion, such as altered hematopoiesis or enhanced autoantibody production, impeded the determination of a conclusive relationship. Methods In this study, we investigated the role of macrophages in mice receiving rabbit anti-glomerular antibodies, or nephrotoxic serum (NTS), an experimental model which closely mimics the immune complex mediated disease seen in murine and human lupus nephritis. GW2580, a selective inhibitor of the colony stimulating factor-1 (CSF-1) receptor kinase, was used for macrophage depletion. Results We found that GW2580-treated, NTS challenged mice did not develop the increased levels of proteinuria, serum creatinine, or serum urea seen in control-treated, NTS challenged mice. NTS challenged mice exhibited significantly increased kidney expression of inflammatory cytokines including RANTES, IP-10, VCAM-1 and iNOS, whereas GW2580-treated mice were protected from the robust expression of these inflammatory cytokines that are associated with LN. Quantification of macrophage related gene expression, flow cytometry analysis of kidney single cell suspensions, and immunofluorescence staining confirmed the depletion of macrophages in GW2580-treated mice, specifically within renal glomeruli. Conclusions Our results strongly implicate a specific and necessary role for macrophages in the development of immune glomerulonephritis mediated by pathogenic antibodies, and support the development of macrophage targeting approaches for the treatment of lupus nephritis. PMID:25554644

  11. High-voltage compatible, full-depleted CCD

    DOEpatents

    Holland, Stephen Edward

    2007-09-18

    A charge coupled device for detecting electromagnetic and particle radiation is described. The device includes a high-resistivity semiconductor substrate, buried channel regions, gate electrode circuitry, and amplifier circuitry. For good spatial resolution and high performance, especially when operated at high voltages with full or nearly full depletion of the substrate, the device can also include a guard ring positioned near channel regions, a biased channel stop, and a biased polysilicon electrode over the channel stop.

  12. Macrophage depletion ameliorates nephritis induced by pathogenic antibodies.

    PubMed

    Chalmers, Samantha A; Chitu, Violeta; Herlitz, Leal C; Sahu, Ranjit; Stanley, E Richard; Putterman, Chaim

    2015-02-01

    Kidney involvement affects 40-60% of patients with lupus, and is responsible for significant morbidity and mortality. Using depletion approaches, several studies have suggested that macrophages may play a key role in the pathogenesis of lupus nephritis. However, "off target" effects of macrophage depletion, such as altered hematopoiesis or enhanced autoantibody production, impeded the determination of a conclusive relationship. In this study, we investigated the role of macrophages in mice receiving rabbit anti-glomerular antibodies, or nephrotoxic serum (NTS), an experimental model which closely mimics the immune complex mediated disease seen in murine and human lupus nephritis. GW2580, a selective inhibitor of the colony stimulating factor-1 (CSF-1) receptor kinase, was used for macrophage depletion. We found that GW2580-treated, NTS challenged mice did not develop the increased levels of proteinuria, serum creatinine, and BUN seen in control-treated, NTS challenged mice. NTS challenged mice exhibited significantly increased kidney expression of inflammatory cytokines including RANTES, IP-10, VCAM-1 and iNOS, whereas GW2580-treated mice were protected from the robust expression of these inflammatory cytokines that are associated with lupus nephritis. Quantification of macrophage related gene expression, flow cytometry analysis of kidney single cell suspensions, and immunofluorescence staining confirmed the depletion of macrophages in GW2580-treated mice, specifically within renal glomeruli. Our results strongly implicate a specific and necessary role for macrophages in the development of immune glomerulonephritis mediated by pathogenic antibodies, and support the development of macrophage targeting approaches for the treatment of lupus nephritis. PMID:25554644

  13. 1,2,3-D Diffusion Depletion Multi-Group

    1992-04-20

    CITATION is designed to solve problems using the finite difference representation of neutron diffusion theory, treating up to three space dimensions with arbitrary group to group scattering. X-y-z, theta-r-z, hexagonal z, and triagonal z geometries may be treated. Depletion problems may be solved and fuel managed for multi-cycle analysis. Extensive first order perturbation results may be obtained given microscopic data and nuclide concentrations. Statics problems may be solved and perturbation results obtained with microscopic data.

  14. Glutamine attenuates post-traumatic glutathione depletion in human muscle.

    PubMed

    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 < 0.05). In contrast, in the glutamine-supplemented group, no significant post-operative decreases in total or reduced glutathione were seen following surgery. Muscle free glutamine had decreased at 72 h after surgery in both groups, by 41.4+/-14.8% (P < 0.05) in the glutamine-supplemented group and by 46.0+/-14.3% (P < 0.05) in the control group. In conclusion, the present study demonstrates that intravenous glutamine supplementation attenuates glutathione depletion in skeletal muscle in humans following standardized surgical trauma.

  15. A search for relativistic electron induced stratospheric ozone depletion

    NASA Technical Reports Server (NTRS)

    Aikin, Arthur C.

    1994-01-01

    Possible ozone changes at 1 mb associated with the time variation and precipitation of relativistic electrons are investigated by examining the NIMBUS 7 SBUV ozone data set and corresponding temperatures derived from NMC data. No ozone depletion was observed in high-latitude summer when temperature fluctuations are small. In winter more variation in ozone occurs, but large temperature changes make it difficult to identify specific ozone decreases as being the result of relativistic electron precipitation.

  16. Optical modulation by carrier depletion in a silicon PIN diode.

    PubMed

    Marris-Morini, Delphine; Le Roux, Xavier; Vivien, Laurent; Cassan, Eric; Pascal, Daniel; Halbwax, Mathieu; Maine, Sylvain; Laval, Suzanne; Fédéli, Jean Marc; Damlencourt, Jean François

    2006-10-30

    Experimental results for refractive index variation induced by depletion in a silicon structure integrated in a PIN diode are reported. Thermal effect has been dissociated from the electrical contribution due to carrier density variation induced by a reverse bias voltage. A figure of merit V(pi)L(pi) of 3.1 V.cm has been obtained at 1.55mum. Numerical simulations show a good agreement between experimental and theoretical index variations. PMID:19529496

  17. Modeling of the dispersion of depleted uranium aerosol.

    PubMed

    Mitsakou, C; Eleftheriadis, K; Housiadas, C; Lazaridis, M

    2003-04-01

    Depleted uranium is a low-cost radioactive material that, in addition to other applications, is used by the military in kinetic energy weapons against armored vehicles. During the Gulf and Balkan conflicts concern has been raised about the potential health hazards arising from the toxic and radioactive material released. The aerosol produced during impact and combustion of depleted uranium munitions can potentially contaminate wide areas around the impact sites or can be inhaled by civilians and military personnel. Attempts to estimate the extent and magnitude of the dispersion were until now performed by complex modeling tools employing unclear assumptions and input parameters of high uncertainty. An analytical puff model accommodating diffusion with simultaneous deposition is developed, which can provide a reasonable estimation of the dispersion of the released depleted uranium aerosol. Furthermore, the period of the exposure for a given point downwind from the release can be estimated (as opposed to when using a plume model). The main result is that the depleted uranium mass is deposited very close to the release point. The deposition flux at a couple of kilometers from the release point is more than one order of magnitude lower than the one a few meters near the release point. The effects due to uncertainties in the key input variables are addressed. The most influential parameters are found to be atmospheric stability, height of release, and wind speed, whereas aerosol size distribution is less significant. The output from the analytical model developed was tested against the numerical model RPM-AERO. Results display satisfactory agreement between the two models.

  18. Production of reactive oxygen species in decoupled, Ca(2+)-depleted PSII and their use in assigning a function to chloride on both sides of PSII.

    PubMed

    Semin, Boris K; Davletshina, Lira N; Timofeev, Kirill N; Ivanov, Il'ya I; Rubin, Andrei B; Seibert, Michael

    2013-11-01

    Extraction of Ca(2+) from the oxygen-evolving complex of photosystem II (PSII) in the absence of a chelator inhibits O2 evolution without significant inhibition of the light-dependent reduction of the exogenous electron acceptor, 2,6-dichlorophenolindophenol (DCPIP) on the reducing side of PSII. The phenomenon is known as "the decoupling effect" (Semin et al. Photosynth Res 98:235-249, 2008). Extraction of Cl(-) from Ca(2+)-depleted membranes (PSII[-Ca]) suppresses the reduction of DCPIP. In the current study we investigated the nature of the oxidized substrate and the nature of the product(s) of the substrate oxidation. After elimination of all other possible donors, water was identified as the substrate. Generation of reactive oxygen species HO, H2O2, and O 2 (·-) , as possible products of water oxidation in PSII(-Ca) membranes was examined. During the investigation of O 2 (·-) production in PSII(-Ca) samples, we found that (i) O 2 (·-) is formed on the acceptor side of PSII due to the reduction of O2; (ii) depletion of Cl(-) does not inhibit water oxidation, but (iii) Cl(-) depletion does decrease the efficiency of the reduction of exogenous electron acceptors. In the absence of Cl(-) under aerobic conditions, electron transport is diverted from reducing exogenous acceptors to reducing O2, thereby increasing the rate of O 2 (·-) generation. From these observations we conclude that the product of water oxidation is H2O2 and that Cl(-) anions are not involved in the oxidation of water to H2O2 in decoupled PSII(-Ca) membranes. These results also indicate that Cl(-) anions are not directly involved in water oxidation by the Mn cluster in the native PSII membranes, but possibly provide access for H2O molecules to the Mn4CaO5 cluster and/or facilitate the release of H(+) ions into the lumenal space.

  19. Haploidentical bone marrow transplantation without T-cell depletion.

    PubMed

    Chang, Ying-Jun; Huang, Xiao-Jun

    2012-12-01

    Approaches for haploidentical bone marrow transplantation (BMT) without T-cell depletion have been designed using new transplant strategies, including anti-thymocyte globulin (ATG) preparative regimens, granulocyte colony-stimulating factor-primed grafts, post-transplantation rapamycin, or high-dose cyclophosphamide (Cy) in combination with other immunosuppressive agents for graft-versus-host disease (GVHD) prophylaxis. These strategies ensured fast hematologic engraftment across the human leukocyte antigen (HLA) barrier with an acceptable incidence of GVHD. Long-term follow-up results from different transplant centers suggest that unmanipulated transplantation may provide an alternative strategy in the haploidentical setting without requiring the technical expertise and cost of ex vivo T-cell depletion. This review discusses immune reconstitution and factors associated with clinical outcomes following unmanipulated haploidentical hematopoietic stem cell transplantation (HSCT), and compares outcomes between unmanipulated haploidentical transplant versus HLA-matched sibling donor (MSD) transplantation, HLA-matched unrelated donor (MUD) transplantation, or unrelated double umbilical cord blood (dUCB) transplantation. Advantages and disadvantages of unmanipulated haploidentical HSCT and strategies to improve outcome after haploidentical BMT without ex vivo T-cell depletion are discussed. PMID:23206842

  20. Transgenic dissection of HIV genes involved in lymphoid depletion.

    PubMed Central

    Tinkle, B T; Ueda, H; Ngo, L; Luciw, P A; Shaw, K; Rosen, C A; Jay, G

    1997-01-01

    Transgenic mice carrying an HIV provirus, with selective deletion of all three structural genes, developed extensive lymphoid depletion which was detected not only in the spleen and lymph nodes but also in the thymus. Mice with a high level of HIV gene expression developed acute disease which resulted in premature death, and mice with a low level of viral transcripts developed chronic disease with long-term survival. Neither HIV replication nor the envelope glycoprotein (gp120) was required for T cell depletion. Despite abundant viral gene expression early in life, cell death did not become evident until about the time of full lymphoid maturation, suggesting that thymopoiesis was not affected. The more mature T cells in the peripheral lymphoid organs and in the thymic medulla were less sensitive to the apoptotic process than the immature T cells in the thymic cortex. Gradual depletion of the T cell compartment in the peripheral lymphoid organs was intimately accompanied by the reciprocal expansion of the B cell compartment, resulting in the almost complete replacement of T lymphocytes with B immunoblasts in lymph nodes. Unlike T cells, which showed abundant HIV gene expression, B cells did not. The transgenic approach may help identify the HIV nonstructural gene(s) responsible for immune deficiency and help facilitate dissection of its role in inducing apoptosis. PMID:9202054

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Accounting for Depletion of Oil and Gas Resources in Malaysia

    SciTech Connect

    Othman, Jamal Jafari, Yaghoob

    2012-12-15

    Since oil and gas are non-renewable resources, it is important to identify the extent to which they have been depleted. Such information will contribute to the formulation and evaluation of appropriate sustainable development policies. This paper provides an assessment of the changes in the availability of oil and gas resources in Malaysia by first compiling the physical balance sheet for the period 2000-2007, and then assessing the monetary balance sheets for the said resource by using the Net Present Value method. Our findings show serious reduction in the value of oil reserves from 2001 to 2005, due to changes in crude oil prices, and thereafter the depletion rates decreased. In the context of sustainable development planning, albeit in the weak sustainability sense, it will be important to ascertain if sufficient reinvestments of the estimated resource rents in related or alternative capitals are being attempted by Malaysia. For the study period, the cumulative resource rents were to the tune of RM61 billion. Through a depletion or resource rents policy, the estimated quantum may guide the identification of a reinvestment threshold (after considering needed capital investment for future development of the industry) in light of ensuring the future productive capacity of the economy at the time when the resource is exhausted.

  3. Depletion of Abundant Plasma Proteins and Limitations of Plasma Proteomics

    PubMed Central

    Tu, Chengjian; Rudnick, Paul A.; Martinez, Misti Y.; Cheek, Kristin L.; Stein, Stephen E.; Slebos, Robbert J. C.; Liebler, Daniel C.

    2010-01-01

    Immunoaffinity depletion with antibodies to the top 7 or top 14 high abundance plasma proteins is used to enhance detection of lower abundance proteins in both shotgun and targeted proteomic analyses. We evaluated the effects of top 7/top 14 immunodepletion on the shotgun proteomic analysis of human plasma. Our goal was to evaluate the impact of immunodepletion on detection of proteins across detectable ranges of abundance. The depletion columns afforded highly repeatable and efficient plasma protein fractionation. Relatively few nontargeted proteins were captured by the depletion columns. Analyses of unfractionated and immunodepleted plasma by peptide isoelectric focusing (IEF), followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) demonstrated enrichment of nontargeted plasma proteins by an average of 4-fold, as assessed by MS/MS spectral counting. Either top 7 or top 14 immunodepletion resulted in a 25% increase in identified proteins compared to unfractionated plasma. Although 23 low abundance (<10 ng mL−1) plasma proteins were detected, they accounted for only 5–6% of total protein identifications in immunodepleted plasma. In both unfractionated and immunodepleted plasma, the 50 most abundant plasma proteins accounted for 90% of cumulative spectral counts and precursor ion intensities, leaving little capacity to sample lower abundance proteins. Untargeted proteomic analyses using current LC-MS/MS platforms—even with immunodepletion—cannot be expected to efficiently discover low abundance, disease-specific biomarkers in plasma. PMID:20677825

  4. Depletion region surface effects in electron beam induced current measurements

    NASA Astrophysics Data System (ADS)

    Haney, Paul M.; Yoon, Heayoung P.; Gaury, Benoit; Zhitenev, Nikolai B.

    2016-09-01

    Electron beam induced current (EBIC) is a powerful characterization technique which offers the high spatial resolution needed to study polycrystalline solar cells. Current models of EBIC assume that excitations in the p-n junction depletion region result in perfect charge collection efficiency. However, we find that in CdTe and Si samples prepared by focused ion beam (FIB) milling, there is a reduced and nonuniform EBIC lineshape for excitations in the depletion region. Motivated by this, we present a model of the EBIC response for excitations in the depletion region which includes the effects of surface recombination from both charge-neutral and charged surfaces. For neutral surfaces, we present a simple analytical formula which describes the numerical data well, while the charged surface response depends qualitatively on the location of the surface Fermi level relative to the bulk Fermi level. We find that the experimental data on FIB-prepared Si solar cells are most consistent with a charged surface and discuss the implications for EBIC experiments on polycrystalline materials.

  5. Structurally Resolved Abundances and Depletions in the Rho OPH Cloud

    NASA Astrophysics Data System (ADS)

    Seab, C.

    1995-07-01

    The mechanism that determines the pattern of depletion ofelements in the interstellar medium has been a problem for along time. It is clear that some of the most refractoryelements such as Si, Fe, and Mg, are heavily depleted onto theinterstellar grains. On the other hand, some elements such asS and Zn are normally either undepleted or very lightlydepleted. The difference between the two cases is notunderstood. We propose to address this question with adetailed study of the depletion patterns in the Rho Ophiuchicloud. This study is strongly based on a combination of thecapabilities of two modern instruments: the GHRS for high-resolution UV data, and the Ultra High Resolution Facility(UHRF) of the AAT. This instrument has been used to obtain NaI line profiles in the Rho Oph cloud with a resolution ofR=1,000,000. The combination of these two types of data willbe used to resolve the velocity structure of the elementdepletions in the cloud.

  6. Frost Induces Respiration and Accelerates Carbon Depletion in Trees.

    PubMed

    Sperling, Or; Earles, J Mason; Secchi, Francesca; Godfrey, Jessie; Zwieniecki, Maciej A

    2015-01-01

    Cellular respiration depletes stored carbohydrates during extended periods of limited photosynthesis, e.g. winter dormancy or drought. As respiration rate is largely a function of temperature, the thermal conditions during such periods may affect non-structural carbohydrate (NSC) availability and, ultimately, recovery. Here, we surveyed stem responses to temperature changes in 15 woody species. For two species with divergent respirational response to frost, P. integerrima and P. trichocarpa, we also examined corresponding changes in NSC levels. Finally, we simulated respiration-induced NSC depletion using historical temperature data for the western US. We report a novel finding that tree stems significantly increase respiration in response to near freezing temperatures. We observed this excess respiration in 13 of 15 species, deviating 10% to 170% over values predicted by the Arrhenius equation. Excess respiration persisted at temperatures above 0 °C during warming and reoccurred over multiple frost-warming cycles. A large adjustment of NSCs accompanied excess respiration in P. integerrima, whereas P. trichocarpa neither excessively respired nor adjusted NSCs. Over the course of the years included in our model, frost-induced respiration accelerated stem NSC consumption by 8.4 mg (glucose eq.) cm(-3) yr(-1) on average in the western US, a level of depletion that may continue to significantly affect spring NSC availability. This novel finding revises the current paradigm of low temperature respiration kinetics. PMID:26629819

  7. Alignment of gold nanorods by angular photothermal depletion

    SciTech Connect

    Taylor, Adam B.; Chow, Timothy T. Y.; Chon, James W. M.

    2014-02-24

    In this paper, we demonstrate that a high degree of alignment can be imposed upon randomly oriented gold nanorod films by angular photothermal depletion with linearly polarized laser irradiation. The photothermal reshaping of gold nanorods is observed to follow quadratic melting model rather than the threshold melting model, which distorts the angular and spectral hole created on 2D distribution map of nanorods to be an open crater shape. We have accounted these observations to the alignment procedures and demonstrated good agreement between experiment and simulations. The use of multiple laser depletion wavelengths allowed alignment criteria over a large range of aspect ratios, achieving 80% of the rods in the target angular range. We extend the technique to demonstrate post-alignment in a multilayer of randomly oriented gold nanorod films, with arbitrary control of alignment shown across the layers. Photothermal angular depletion alignment of gold nanorods is a simple, promising post-alignment method for creating future 3D or multilayer plasmonic nanorod based devices and structures.

  8. Frost Induces Respiration and Accelerates Carbon Depletion in Trees

    PubMed Central

    Sperling, Or; Earles, J. Mason; Secchi, Francesca; Godfrey, Jessie; Zwieniecki, Maciej A.

    2015-01-01

    Cellular respiration depletes stored carbohydrates during extended periods of limited photosynthesis, e.g. winter dormancy or drought. As respiration rate is largely a function of temperature, the thermal conditions during such periods may affect non-structural carbohydrate (NSC) availability and, ultimately, recovery. Here, we surveyed stem responses to temperature changes in 15 woody species. For two species with divergent respirational response to frost, P. integerrima and P. trichocarpa, we also examined corresponding changes in NSC levels. Finally, we simulated respiration-induced NSC depletion using historical temperature data for the western US. We report a novel finding that tree stems significantly increase respiration in response to near freezing temperatures. We observed this excess respiration in 13 of 15 species, deviating 10% to 170% over values predicted by the Arrhenius equation. Excess respiration persisted at temperatures above 0°C during warming and reoccurred over multiple frost-warming cycles. A large adjustment of NSCs accompanied excess respiration in P. integerrima, whereas P. trichocarpa neither excessively respired nor adjusted NSCs. Over the course of the years included in our model, frost-induced respiration accelerated stem NSC consumption by 8.4 mg (glucose eq.) cm-3 yr-1 on average in the western US, a level of depletion that may continue to significantly affect spring NSC availability. This novel finding revises the current paradigm of low temperature respiration kinetics. PMID:26629819

  9. Ionospheric heating, upwelling, and depletions in auroral current systems

    NASA Astrophysics Data System (ADS)

    Zettergren, M. D.; Semeter, J. L.

    2010-12-01

    This research investigates aspects of ionospheric dynamics relevant to magnetosphere-ionosphere coupling in auroral arc current systems. Auroral electric fields and particle precipitation deposit energy in the ionosphere, often resulting in enhanced ion or electron temperatures. This heating has a wide variety of consequences for the ionosphere. High ion temperatures alter chemical balance in the lower F-region, resulting in conversion to a molecular ion plasma, faster recombination, and plasma depletions. Pressure enhancements resulting from both ion and electron heating are capable of generating intense ion upflows. Ion upflow and depletion processes redistribute and structure the auroral plasma in ways that are likely of consequence to wave coupling of the magnetosphere and ionosphere. These implications are examined through the use of a fluid-kinetic model of the auroral ionosphere and new incoherent scatter radar data analysis techniques. Results indicate that enhanced recombination of molecular ions in auroral downward current regions may work in concert with well-known electrodynamic depletion processes, in the F-region ionosphere. Furthermore, ionospheric upflows in auroral upward and downward current regions may be quite different in terms of intensity and types of upflowing ions.

  10. Frost Induces Respiration and Accelerates Carbon Depletion in Trees.

    PubMed

    Sperling, Or; Earles, J Mason; Secchi, Francesca; Godfrey, Jessie; Zwieniecki, Maciej A

    2015-01-01

    Cellular respiration depletes stored carbohydrates during extended periods of limited photosynthesis, e.g. winter dormancy or drought. As respiration rate is largely a function of temperature, the thermal conditions during such periods may affect non-structural carbohydrate (NSC) availability and, ultimately, recovery. Here, we surveyed stem responses to temperature changes in 15 woody species. For two species with divergent respirational response to frost, P. integerrima and P. trichocarpa, we also examined corresponding changes in NSC levels. Finally, we simulated respiration-induced NSC depletion using historical temperature data for the western US. We report a novel finding that tree stems significantly increase respiration in response to near freezing temperatures. We observed this excess respiration in 13 of 15 species, deviating 10% to 170% over values predicted by the Arrhenius equation. Excess respiration persisted at temperatures above 0 °C during warming and reoccurred over multiple frost-warming cycles. A large adjustment of NSCs accompanied excess respiration in P. integerrima, whereas P. trichocarpa neither excessively respired nor adjusted NSCs. Over the course of the years included in our model, frost-induced respiration accelerated stem NSC consumption by 8.4 mg (glucose eq.) cm(-3) yr(-1) on average in the western US, a level of depletion that may continue to significantly affect spring NSC availability. This novel finding revises the current paradigm of low temperature respiration kinetics.

  11. Submolecular regulation of cell transformation by deuterium depleting water exchange reactions in the tricarboxylic acid substrate cycle.

    PubMed

    Boros, László G; D'Agostino, Dominic P; Katz, Howard E; Roth, Justine P; Meuillet, Emmanuelle J; Somlyai, Gábor

    2016-02-01

    The naturally occurring isotope of hydrogen ((1)H), deuterium ((2)H), could have an important biological role. Deuterium depleted water delays tumor progression in mice, dogs, cats and humans. Hydratase enzymes of the tricarboxylic acid (TCA) cycle control cell growth and deplete deuterium from redox cofactors, fatty acids and DNA, which undergo hydride ion and hydrogen atom transfer reactions. A model is proposed that emphasizes the terminal complex of mitochondrial electron transport chain reducing molecular oxygen to deuterium depleted water (DDW); this affects gluconeogenesis as well as fatty acid oxidation. In the former, the DDW is thought to diminish the deuteration of sugar-phosphates in the DNA backbone, helping to preserve stability of hydrogen bond networks, possibly protecting against aneuploidy and resisting strand breaks, occurring upon exposure to radiation and certain anticancer chemotherapeutics. DDW is proposed here to link cancer prevention and treatment using natural ketogenic diets, low deuterium drinking water, as well as DDW production as the mitochondrial downstream mechanism of targeted anti-cancer drugs such as Avastin and Glivec. The role of (2)H in biology is a potential missing link to the elusive cancer puzzle seemingly correlated with cancer epidemiology in western populations as a result of excessive (2)H loading from processed carbohydrate intake in place of natural fat consumption.

  12. Hepatic n-3 Polyunsaturated Fatty Acid Depletion Promotes Steatosis and Insulin Resistance in Mice: Genomic Analysis of Cellular Targets

    PubMed Central

    Pachikian, Barbara D.; Essaghir, Ahmed; Demoulin, Jean-Baptiste; Neyrinck, Audrey M.; Catry, Emilie; De Backer, Fabienne C.; Dejeans, Nicolas; Dewulf, Evelyne M.; Sohet, Florence M.; Portois, Laurence; Deldicque, Louise; Molendi-Coste, Olivier; Leclercq, Isabelle A.; Francaux, Marc; Carpentier, Yvon A.; Foufelle, Fabienne; Muccioli, Giulio G.; Cani, Patrice D.; Delzenne, Nathalie M.

    2011-01-01

    Patients with non-alcoholic fatty liver disease are characterised by a decreased n-3/n-6 polyunsaturated fatty acid (PUFA) ratio in hepatic phospholipids. The metabolic consequences of n-3 PUFA depletion in the liver are poorly understood. We have reproduced a drastic drop in n-3 PUFA among hepatic phospholipids by feeding C57Bl/6J mice for 3 months with an n-3 PUFA depleted diet (DEF) versus a control diet (CT), which only differed in the PUFA content. DEF mice exhibited hepatic insulin resistance (assessed by euglycemic-hyperinsulinemic clamp) and steatosis that was associated with a decrease in fatty acid oxidation and occurred despite a higher capacity for triglyceride secretion. Microarray and qPCR analysis of the liver tissue revealed higher expression of all the enzymes involved in lipogenesis in DEF mice compared to CT mice, as well as increased expression and activation of sterol regulatory element binding protein-1c (SREBP-1c). Our data suggest that the activation of the liver X receptor pathway is involved in the overexpression of SREBP-1c, and this phenomenon cannot be attributed to insulin or to endoplasmic reticulum stress responses. In conclusion, n-3 PUFA depletion in liver phospholipids leads to activation of SREBP-1c and lipogenesis, which contributes to hepatic steatosis. PMID:21853118

  13. Estimation of Carbon Dioxide Storage Capacity for Depleted Gas Reservoirs

    NASA Astrophysics Data System (ADS)

    Lai, Yen Ting; Shen, Chien-Hao; Tseng, Chi-Chung; Fan, Chen-Hui; Hsieh, Bieng-Zih

    2015-04-01

    A depleted gas reservoir is one of the best options for CO2 storage for many reasons. First of all, the storage safety or the caprock integrity has been proven because the natural gas was trapped in the formation for a very long period of time. Also the formation properties and fluid flow characteristics for the reservoir have been well studied since the discovery of the gas reservoir. Finally the surface constructions and facilities are very useful and relatively easy to convert for the use of CO2 storage. The purpose of this study was to apply an analytical approach to estimate CO2 storage capacity in a depleted gas reservoir. The analytical method we used is the material balance equation (MBE), which have been widely used in natural gas storage. We proposed a modified MBE for CO2 storage in a depleted gas reservoir by introducing the z-factors of gas, CO2 and the mixture of the two. The MBE can be derived to a linear relationship between the ratio of pressure to gas z-factor (p/z) and the cumulative term (Gp-Ginj, where Gp is the cumulative gas production and Ginj is the cumulative CO2 injection). The CO2 storage capacity can be calculated when constraints of reservoir recovery pressure are adopted. The numerical simulation was also used for the validation of the theoretical estimation of CO2 storage capacity from the MBE. We found that the quantity of CO2 stored is more than that of gas produced when the reservoir pressure is recovered from the abandon pressure to the initial pressure. This result was basically from the fact that the gas- CO2 mixture z-factors are lower than the natural gas z-factors in reservoir conditions. We also established a useful p/z plot to easily observe the pressure behavior of CO2 storage and efficiently calculate the CO2 storage capacity. The application of the MBE we proposed was demonstrated by a case study of a depleted gas reservoir in northwestern Taiwan. The estimated CO2 storage capacities from conducting reservoir simulation

  14. Effect of Phosphate Depletion on Magnesium Homeostasis in Rats

    PubMed Central

    Kreusser, Wilhelm J.; Kurokawa, Kiyoshi; Aznar, Enrique; Sachtjen, Ellen; Massry, Shaul G.

    1978-01-01

    The effects of phosphate depletion on magnesium (Mg) homeostasis were evaluated in rats fed a diet containing 0.03% phosphorus for periods up to 8 wk. Plasma phosphorus fell significantly (P < 0.01) from 10.1±0.27 (SE) to 5.0±0.54 mg/100 ml within 1 day and continued to fall gradually to a level of 1.2±0.21 mg/100 ml by the end of the 8th wk. A significant (P < 0.01) increment in urinary Mg excretion (UMgV) from 46±2.7 to 126±24 μeq/24 h occurred during the 1st day of phosphate depletion; UMgV reached a peak of 300±24 μeq/24 h by the 3rd day and remained high ranging between 150-300 μeq/24 h, thereafter. The magnitude of the magnesuria was related to the degree of hypophosphatemia and was not affected by lowering the calcium intake and reducing the hypercalciuria. The concentration of plasma Mg fell significantly (P < 0.01) from 1.2±0.02 to 0.79±0.10 meq/liter by the 1st day of the study and remained low throughout. Mg balance became negative during the 1st day of phosphate depletion and remained so during the entire study. This occurred despite a significant increment in the fraction of ingested Mg absorbed which became evident by the 3rd wk of phosphate depletion. Mg content of muscle, kidney, and liver were not affected but bone Mg was reduced significantly. The change in bone Mg was not due to an overall reduction in bone mineral content because bone calcium content was not affected. Supplementation of large amounts of Mg (800-1,000 μeq/day) in the drinking water produced a normalization of serum Mg but did not bring about restoration of bone Mg despite a positive Mg balance. The disturbances in Mg metabolism were independent of the age or weight of the animals. Our results indicate that phosphate depletion is associated with (a) magnesuria due to a decrease in the net renal tubular reabsorption of Mg with the main source of the urinary losses being bone Mg; (b) hypomagnesemia secondary to the renal leak of Mg; (c) negative Mg balance; and (d

  15. Ozone depletion and climate change: impacts on UV radiation.

    PubMed

    McKenzie, R L; Aucamp, P J; Bais, A F; Björn, L O; Ilyas, M; Madronich, S

    2011-02-01

    The Montreal Protocol is working, but it will take several decades for ozone to return to 1980 levels. The atmospheric concentrations of ozone depleting substances are decreasing, and ozone column amounts are no longer decreasing. Mid-latitude ozone is expected to return to 1980 levels before mid-century, slightly earlier than predicted previously. However, the recovery rate will be slower at high latitudes. Springtime ozone depletion is expected to continue to occur at polar latitudes, especially in Antarctica, in the next few decades. Because of the success of the Protocol, increases in UV-B radiation have been small outside regions affected by the Antarctic ozone hole, and have been difficult to detect. There is a large variability in UV-B radiation due to factors other than ozone, such as clouds and aerosols. There are few long-term measurements available to confirm the increases that would have occurred as a result of ozone depletion. At mid-latitudes UV-B irradiances are currently only slightly greater than in 1980 (increases less than ~5%), but increases have been substantial at high and polar latitudes where ozone depletion has been larger. Without the Montreal Protocol, peak values of sunburning UV radiation could have been tripled by 2065 at mid-northern latitudes. This would have had serious consequences for the environment and for human health. There are strong interactions between ozone depletion and changes in climate induced by increasing greenhouse gases (GHGs). Ozone depletion affects climate, and climate change affects ozone. The successful implementation of the Montreal Protocol has had a marked effect on climate change. The calculated reduction in radiative forcing due to the phase-out of chlorofluorocarbons (CFCs) far exceeds that from the measures taken under the Kyoto protocol for the reduction of GHGs. Thus the phase-out of CFCs is currently tending to counteract the increases in surface temperature due to increased GHGs. The amount of

  16. Ozone depletion and climate change: impacts on UV radiation.

    PubMed

    McKenzie, R L; Aucamp, P J; Bais, A F; Björn, L O; Ilyas, M; Madronich, S

    2011-02-01

    The Montreal Protocol is working, but it will take several decades for ozone to return to 1980 levels. The atmospheric concentrations of ozone depleting substances are decreasing, and ozone column amounts are no longer decreasing. Mid-latitude ozone is expected to return to 1980 levels before mid-century, slightly earlier than predicted previously. However, the recovery rate will be slower at high latitudes. Springtime ozone depletion is expected to continue to occur at polar latitudes, especially in Antarctica, in the next few decades. Because of the success of the Protocol, increases in UV-B radiation have been small outside regions affected by the Antarctic ozone hole, and have been difficult to detect. There is a large variability in UV-B radiation due to factors other than ozone, such as clouds and aerosols. There are few long-term measurements available to confirm the increases that would have occurred as a result of ozone depletion. At mid-latitudes UV-B irradiances are currently only slightly greater than in 1980 (increases less than ~5%), but increases have been substantial at high and polar latitudes where ozone depletion has been larger. Without the Montreal Protocol, peak values of sunburning UV radiation could have been tripled by 2065 at mid-northern latitudes. This would have had serious consequences for the environment and for human health. There are strong interactions between ozone depletion and changes in climate induced by increasing greenhouse gases (GHGs). Ozone depletion affects climate, and climate change affects ozone. The successful implementation of the Montreal Protocol has had a marked effect on climate change. The calculated reduction in radiative forcing due to the phase-out of chlorofluorocarbons (CFCs) far exceeds that from the measures taken under the Kyoto protocol for the reduction of GHGs. Thus the phase-out of CFCs is currently tending to counteract the increases in surface temperature due to increased GHGs. The amount of

  17. VESTA 2.1.5 - Monte Carlo Depletion Interface Code; AURORA 1.0.0 - Depletion Analysis Tool.

    SciTech Connect

    HAECK, WIM

    2013-03-21

    Version 01 RSICC is authorized to distribute VESTA 2.1.5 for research and education purposes only. Requesters from NEA Data Bank member countries are advised to order VESTA 2.1.5 from the NEA Data Bank. Non-commercial and non-profit users from other OECD member countries (specifically Canada and the United States) may order VESTA 2.1.5 from RSICC. Users from non-OECD member countries and all commercial requesters are advised to contact the IRSN. VESTA is a Monte Carlo depletion interface code that is currently under development at IRSN (France). From its inception, VESTA is intended to be a “generic” interface code so that it will ultimately be capable of using any Monte-Carlo code or depletion module and that can be completely tailored to the user’s needs on practically all aspects of the code. For the current version, VESTA allows for the use of any version of MCNP(X) as the transport module and ORIGEN 2.2 or the built in PHOENIX module as the depletion module. A short overview of the main features of this version of the code is detailed in the Abstract.

  18. Environmental assessment of depleted uranium used in military armor-piercing rounds in terrestrial systems.

    PubMed

    Stanley, Jacob K; Coleman, Jessica G; Brasfield, Sandra M; Bednar, Anthony J; Ang, Choo Y

    2014-06-01

    Depleted uranium (DU) from the military testing and use of armor-piercing kinetic energy penetrators has been shown to accumulate in soils; however, little is known about the toxicity of DU geochemical species created through corrosion or weathering. The purpose of the present study was to assess the toxic effects and bioaccumulation potential of field-collected DU oxides to the model terrestrial invertebrates Eisenia fetida (earthworm) and Porcellio scaber (isopod). Earthworm studies were acute (72 h) dermal exposures or 28-d spiked soil exposures that used noncontaminated field-collected soils from the US Army's Yuma and Aberdeen Proving Grounds. Endpoints assessed in earthworm testing included bioaccumulation, growth, reproduction, behavior (soil avoidance), and cellular stress (neutral red uptake in coelomocytes). Isopod testing used spiked food, and endpoints assessed included bioaccumulation, survival, and feeding behavior. Concentration-dependent bioaccumulation of DU in earthworms was observed with a maximum bioaccumulation factor of 0.35; however, no significant reductions in survival or impacts to cellular stress were observed. Reproduction lowest-observed-effect concentrations (LOEC) of 158 mg/kg and 96 mg/kg were observed in Yuma Proving Ground and a Mississippi reference soil (Karnac Ferry), respectively. Earthworm avoidance of contaminated soils was not observed in 48-h soil avoidance studies; however, isopods were shown to avoid food spiked with 12.7% by weight DU oxides through digital tracking studies. PMID:24549573

  19. Depletion of reduction potential and key energy generation metabolic enzymes underlies tellurite toxicity in Deinococcus radiodurans.

    PubMed

    Anaganti, Narasimha; Basu, Bhakti; Gupta, Alka; Joseph, Daisy; Apte, Shree Kumar

    2015-01-01

    Oxidative stress resistant Deinococcus radiodurans surprisingly exhibited moderate sensitivity to tellurite induced oxidative stress (LD50 = 40 μM tellurite, 40 min exposure). The organism reduced 70% of 40 μM potassium tellurite within 5 h. Tellurite exposure significantly modulated cellular redox status. The level of ROS and protein carbonyl contents increased while the cellular reduction potential substantially decreased following tellurite exposure. Cellular thiols levels initially increased (within 30 min) of tellurite exposure but decreased at later time points. At proteome level, tellurite resistance proteins (TerB and TerD), tellurite reducing enzymes (pyruvate dehydrogense subunits E1 and E3), ROS detoxification enzymes (superoxide dismutase and thioredoxin reductase), and protein folding chaperones (DnaK, EF-Ts, and PPIase) displayed increased abundance in tellurite-stressed cells. However, remarkably decreased levels of key metabolic enzymes (aconitase, transketolase, 3-hydroxy acyl-CoA dehydrogenase, acyl-CoA dehydrogenase, electron transfer flavoprotein alpha, and beta) involved in carbon and energy metabolism were observed upon tellurite stress. The results demonstrate that depletion of reduction potential in intensive tellurite reduction with impaired energy metabolism lead to tellurite toxicity in D. radiodurans.

  20. Depletion of reduction potential and key energy generation metabolic enzymes underlies tellurite toxicity in Deinococcus radiodurans.

    PubMed

    Anaganti, Narasimha; Basu, Bhakti; Gupta, Alka; Joseph, Daisy; Apte, Shree Kumar

    2015-01-01

    Oxidative stress resistant Deinococcus radiodurans surprisingly exhibited moderate sensitivity to tellurite induced oxidative stress (LD50 = 40 μM tellurite, 40 min exposure). The organism reduced 70% of 40 μM potassium tellurite within 5 h. Tellurite exposure significantly modulated cellular redox status. The level of ROS and protein carbonyl contents increased while the cellular reduction potential substantially decreased following tellurite exposure. Cellular thiols levels initially increased (within 30 min) of tellurite exposure but decreased at later time points. At proteome level, tellurite resistance proteins (TerB and TerD), tellurite reducing enzymes (pyruvate dehydrogense subunits E1 and E3), ROS detoxification enzymes (superoxide dismutase and thioredoxin reductase), and protein folding chaperones (DnaK, EF-Ts, and PPIase) displayed increased abundance in tellurite-stressed cells. However, remarkably decreased levels of key metabolic enzymes (aconitase, transketolase, 3-hydroxy acyl-CoA dehydrogenase, acyl-CoA dehydrogenase, electron transfer flavoprotein alpha, and beta) involved in carbon and energy metabolism were observed upon tellurite stress. The results demonstrate that depletion of reduction potential in intensive tellurite reduction with impaired energy metabolism lead to tellurite toxicity in D. radiodurans. PMID:25331933

  1. Genome and physiology of a model Epsilonproteobacterium responsible for sulfide detoxification in marine oxygen depletion zones.

    PubMed

    Grote, Jana; Schott, Thomas; Bruckner, Christian G; Glöckner, Frank Oliver; Jost, Günter; Teeling, Hanno; Labrenz, Matthias; Jürgens, Klaus

    2012-01-10

    Eutrophication and global climate change lead to expansion of hypoxia in the ocean, often accompanied by the production of hydrogen sulfide, which is toxic to higher organisms. Chemoautotrophic bacteria are thought to buffer against increased sulfide concentrations by oxidizing hydrogen sulfide before its diffusion to oxygenated surface waters. Model organisms from such environments have not been readily available, which has contributed to a poor understanding of these microbes. We present here a detailed study of "Sulfurimonas gotlandica" str. GD1, an Epsilonproteobacterium isolated from the Baltic Sea oxic-anoxic interface, where it plays a key role in nitrogen and sulfur cycling. Whole-genome analysis and laboratory experiments revealed a high metabolic flexibility, suggesting a considerable capacity for adaptation to variable redox conditions. S. gotlandica str. GD1 was shown to grow chemolithoautotrophically by coupling denitrification with oxidation of reduced sulfur compounds and dark CO(2) fixation. Metabolic versatility was further suggested by the use of a range of different electron donors and acceptors and organic carbon sources. The number of genes involved in signal transduction and metabolic pathways exceeds those of other Epsilonproteobacteria. Oxygen tolerance and environmental-sensing systems combined with chemotactic responses enable this organism to thrive successfully in marine oxygen-depletion zones. We propose that S. gotlandica str. GD1 will serve as a model organism in investigations that will lead to a better understanding how members of the Epsilonproteobacteria are able to cope with water column anoxia and the role these microorganisms play in the detoxification of sulfidic waters.

  2. Environmental assessment of depleted uranium used in military armor-piercing rounds in terrestrial systems.

    PubMed

    Stanley, Jacob K; Coleman, Jessica G; Brasfield, Sandra M; Bednar, Anthony J; Ang, Choo Y

    2014-06-01

    Depleted uranium (DU) from the military testing and use of armor-piercing kinetic energy penetrators has been shown to accumulate in soils; however, little is known about the toxicity of DU geochemical species created through corrosion or weathering. The purpose of the present study was to assess the toxic effects and bioaccumulation potential of field-collected DU oxides to the model terrestrial invertebrates Eisenia fetida (earthworm) and Porcellio scaber (isopod). Earthworm studies were acute (72 h) dermal exposures or 28-d spiked soil exposures that used noncontaminated field-collected soils from the US Army's Yuma and Aberdeen Proving Grounds. Endpoints assessed in earthworm testing included bioaccumulation, growth, reproduction, behavior (soil avoidance), and cellular stress (neutral red uptake in coelomocytes). Isopod testing used spiked food, and endpoints assessed included bioaccumulation, survival, and feeding behavior. Concentration-dependent bioaccumulation of DU in earthworms was observed with a maximum bioaccumulation factor of 0.35; however, no significant reductions in survival or impacts to cellular stress were observed. Reproduction lowest-observed-effect concentrations (LOEC) of 158 mg/kg and 96 mg/kg were observed in Yuma Proving Ground and a Mississippi reference soil (Karnac Ferry), respectively. Earthworm avoidance of contaminated soils was not observed in 48-h soil avoidance studies; however, isopods were shown to avoid food spiked with 12.7% by weight DU oxides through digital tracking studies.

  3. Assessing the Renal Toxicity of Capstone Depleted Uranium Oxides and Other Uranium Compounds

    SciTech Connect

    Roszell, Laurie E.; Hahn, Fletcher; Lee, Robyn B.; Parkhurst, MaryAnn

    2009-02-26

    The primary target for uranium toxicity is the kidney. The most frequently used guideline for uranium kidney burdens is the International Commission on Radiation Protection (ICRP) value of 3 µg U/g kidney, a value that is based largely upon chronic studies in animals. In the present effort, we have developed a risk model equation to assess potential outcomes of acute uranium exposure. Twenty-seven previously published case studies in which workers were acutely exposed to soluble compounds of uranium (as a result of workplace accidents) were analyzed. Kidney burdens of uranium for these individuals were determined based on uranium in the urine, and correlated with health effects observed over a period of up to 38 years. Based upon the severity of health effects, each individual was assigned a score (- to +++) and then placed into an Effect Group. A discriminant analysis was used to build a model equation to predict the Effect Group based on the amount of uranium in the kidneys. The model equation was able to predict the Effect Group with 85% accuracy. The risk model was used to predict the Effect Group for Soldiers exposed to DU as a result of friendly fire incidents during the 1991 Gulf War. This model equation can also be used to predict the Effect Group of new cases in which acute exposures to uranium have occurred.

  4. Nature gives us strength: exposure to nature counteracts ego-depletion.

    PubMed

    Chow, Jason T; Lau, Shun

    2015-01-01

    Previous research rarely investigated the role of physical environment in counteracting ego-depletion. In the present research, we hypothesized that exposure to natural environment counteracts ego-depletion. Three experiments were conducted to test this hypothesis. In Experiment 1, initially depleted participants who viewed pictures of nature scenes showed greater persistence on a subsequent anagram task than those who were given a rest period. Experiment 2 expanded upon this finding by showing that natural environment enhanced logical reasoning performance after ego-depleting task. Experiment 3 adopted a two- (depletion vs. no-depletion) -by-two (nature exposure vs. urban exposure) factorial design. We found that nature exposure moderated the effect of depletion on anagram task performance. Taken together, the present studies offer a viable and novel strategy to mitigate the negative impacts of ego-depletion.

  5. High-Temperature, Oxidation-Resistant Thermocouples

    NASA Technical Reports Server (NTRS)

    Smialek, James L.; Gedwill, Michael A.

    1994-01-01

    Aluminum substituted for rhodium, which is scarce and expensive. Electromotive force increases with aluminum content in Pt/Al leg of Pt(Pt/Al) thermocouple. Wires baked longer in aluminizing bed produce larger voltages. Thermocouples containing platinum/aluminum legs used instead of thermocouples of type R in furnaces, heat engines, and chemical reactors. Expecially suited to high-velocity oxidizing environments. Constructed as thin-film sensors on turbine blades and vanes, where pre-oxidation provides insulating film needed between thermocouple legs. Because aluminum content slowly depleted by oxidation, long-term use recommended only where maximum temperature is 1,200 degrees C or less.

  6. 48 CFR 211.271 - Elimination of use of class I ozone-depleting substances.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... class I ozone-depleting substances. 211.271 Section 211.271 Federal Acquisition Regulations System... Using and Maintaining Requirements Documents 211.271 Elimination of use of class I ozone-depleting substances. See subpart 223.8 for restrictions on contracting for ozone-depleting substances....

  7. 26 CFR 52.4681-1 - Taxes imposed with respect to ozone-depleting chemicals.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Taxes imposed with respect to ozone-depleting... to ozone-depleting chemicals. (a) Taxes imposed. Sections 4681 and 4682 impose the following taxes with respect to ozone-depleting chemicals (ODCs): (1) Tax on ODCs. Section 4681(a)(1) imposes a tax...

  8. 48 CFR 211.271 - Elimination of use of class I ozone-depleting substances.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... class I ozone-depleting substances. 211.271 Section 211.271 Federal Acquisition Regulations System... Using and Maintaining Requirements Documents 211.271 Elimination of use of class I ozone-depleting substances. See subpart 223.8 for restrictions on contracting for ozone-depleting substances....

  9. 48 CFR 211.271 - Elimination of use of class I ozone-depleting substances.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... class I ozone-depleting substances. 211.271 Section 211.271 Federal Acquisition Regulations System... Using and Maintaining Requirements Documents 211.271 Elimination of use of class I ozone-depleting substances. See subpart 223.8 for restrictions on contracting for ozone-depleting substances....

  10. 26 CFR 52.4681-1 - Taxes imposed with respect to ozone-depleting chemicals.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 17 2011-04-01 2011-04-01 false Taxes imposed with respect to ozone-depleting... to ozone-depleting chemicals. (a) Taxes imposed. Sections 4681 and 4682 impose the following taxes with respect to ozone-depleting chemicals (ODCs): (1) Tax on ODCs. Section 4681(a)(1) imposes a tax...

  11. 26 CFR 52.4681-1 - Taxes imposed with respect to ozone-depleting chemicals.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 17 2014-04-01 2014-04-01 false Taxes imposed with respect to ozone-depleting... to ozone-depleting chemicals. (a) Taxes imposed. Sections 4681 and 4682 impose the following taxes with respect to ozone-depleting chemicals (ODCs): (1) Tax on ODCs. Section 4681(a)(1) imposes a tax...

  12. 26 CFR 52.4681-1 - Taxes imposed with respect to ozone-depleting chemicals.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 17 2012-04-01 2012-04-01 false Taxes imposed with respect to ozone-depleting... to ozone-depleting chemicals. (a) Taxes imposed. Sections 4681 and 4682 impose the following taxes with respect to ozone-depleting chemicals (ODCs): (1) Tax on ODCs. Section 4681(a)(1) imposes a tax...

  13. 26 CFR 52.4681-1 - Taxes imposed with respect to ozone-depleting chemicals.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 17 2013-04-01 2013-04-01 false Taxes imposed with respect to ozone-depleting... to ozone-depleting chemicals. (a) Taxes imposed. Sections 4681 and 4682 impose the following taxes with respect to ozone-depleting chemicals (ODCs): (1) Tax on ODCs. Section 4681(a)(1) imposes a tax...

  14. 48 CFR 211.271 - Elimination of use of class I ozone-depleting substances.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... class I ozone-depleting substances. 211.271 Section 211.271 Federal Acquisition Regulations System... Using and Maintaining Requirements Documents 211.271 Elimination of use of class I ozone-depleting substances. See subpart 223.8 for restrictions on contracting for ozone-depleting substances....

  15. 48 CFR 211.271 - Elimination of use of class I ozone-depleting substances.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... class I ozone-depleting substances. 211.271 Section 211.271 Federal Acquisition Regulations System... Using and Maintaining Requirements Documents 211.271 Elimination of use of class I ozone-depleting substances. See subpart 223.8 for restrictions on contracting for ozone-depleting substances....

  16. 26 CFR 1.611-1 - Allowance of deduction for depletion.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... TAX (CONTINUED) INCOME TAXES (CONTINUED) Natural Resources § 1.611-1 Allowance of deduction for depletion. (a) Depletion of mines, oil and gas wells, other natural deposits, and timber—(1) In general... of the property. In the case of other exhaustible natural resources the allowance for depletion...

  17. 26 CFR 1.611-1 - Allowance of deduction for depletion.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... TAX (CONTINUED) INCOME TAXES (CONTINUED) Natural Resources § 1.611-1 Allowance of deduction for depletion. (a) Depletion of mines, oil and gas wells, other natural deposits, and timber—(1) In general... of the property. In the case of other exhaustible natural resources the allowance for depletion...

  18. Depletable resources: necessary, in need of fair treatment, and multi-functional.

    PubMed

    Harvey, Nigel

    2013-12-01

    I make three points. First, processors and depletable resources should not be regarded as alternative means of processing information: they are both necessary. Second, comparing a processor account with a rational allocation mechanism to a depletable-resources account without one is not a fair comparison. Third, depletable resources can act as signals as well as fuels.

  19. Estimation of stream depletion using values of capacitance

    NASA Astrophysics Data System (ADS)

    Baldenkov, Mikhail; Filimonova, Elena

    2014-05-01

    Compensation pumping is used to alleviate deficiencies in streamflow discharge during dry seasons. Short-term groundwater pumping can use aquifer storage instead of catchment-zone water until the drawdown reaches the edge of the stream. Stream-aquifer interactions are the key component of the hydrologic budgets and estimation of stream depletion has top-priority when evaluating the effectiveness of application of seasonal compensation pumping. Numerous analytical equations have been developed to assess the influence of groundwater pumping on nearby streams (C.V. Theis, R.E. Glover, C.G. Balmer, M.S. Hantush, C.T. Jenkins, B. Hunt, J. Bredehoeft, V.A. Zlotnik, E.L. Minkin, N.N. Lapshin, F.M. Bochever and other researchers). R.B. Wallace and Y. Darama obtained solution for cyclic conditions groundwater pumping. Numerical model approaches used in difficult hydrogeological conditions. It is offered to estimate stream depletion by seasonal pumping using values of capacitance (complex, dimensionless parameter of an aquifer system that defines the delayed effect on steamflow when there is groundwater pumping). Capacitance (C) is determined by the following equation: ( ) L* C = f( °---) , TS-Δt where S and T are the aquifer specific yield (or storage coefficient for a confined aquifer) and transmissivity, respectively; Δt is the pumping time inside one cycle, L* is the summarizing distance between the compensation well and stream edge; in some cases it can involve a function of the stream leakance and vertical leakance of the impermeable layer. Three typical hydraulic cases of compensation pumping were classified depending on their capacitance structure (i.e. the relationship between surface water and groundwater): (a) perfect hydraulic connection between the stream and aquifer; (b) imperfect hydraulic connection between the stream and aquifer; and (c) essentially imperfect hydraulic connection between the stream and the underlying confined aquifer. The form of

  20. Regulation of lipid flux between liver and adipose tissue during transient hepatic steatosis in carnitine-depleted rats.

    PubMed

    Degrace, Pascal; Demizieux, Laurent; Du, Zhen-Yu; Gresti, Joseph; Caverot, Laurent; Djaouti, Louiza; Jourdan, Tony; Moindrot, Bastien; Guilland, Jean-Claude; Hocquette, Jean-François; Clouet, Pierre

    2007-07-20

    Rats with carnitine deficiency due to trimethylhydrazinium propionate (mildronate) administered at 80 mg/100 g body weight per day for 10 days developed liver steatosis only upon fasting. This study aimed to determine whether the transient steatosis resulted from triglyceride accumulation due to the amount of fatty acids preserved through impaired fatty acid oxidation and/or from up-regulation of lipid exchange between liver and adipose tissue. In liver, mildronate decreased the carnitine content by approximately 13-fold and, in fasted rats, lowered the palmitate oxidation rate by 50% in the perfused organ, increased 9-fold the triglyceride content, and doubled the hepatic very low density lipoprotein secretion rate. Concomitantly, triglyceridemia was 13-fold greater than in controls. Hepatic carnitine palmitoyltransferase I activity and palmitate oxidation capacities measured in vitro were increased after treatment. Gene expression of hepatic proteins involved in fatty acid oxidation, triglyceride formation, and lipid uptake were all increased and were associated with increased hepatic free fatty acid content in treated rats. In periepididymal adipose tissue, mildronate markedly increased lipoprotein lipase and hormone-sensitive lipase activities in fed and fasted rats, respectively. On refeeding, carnitine-depleted rats exhibited a rapid decrease in blood triglycerides and free fatty acids, then after approximately 2 h, a marked drop of liver triglycerides and a progressive decrease in liver free fatty acids. Data show that up-regulation of liver activities, peripheral lipolysis, and lipoprotein lipase activity were likely essential factors for excess fat deposit and release alternately occurring in liver and adipose tissue of carnitine-depleted rats during the fed/fasted transition.